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TOMOYO Linux Cross Reference
Linux/fs/ocfs2/alloc.c

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  1 /* -*- mode: c; c-basic-offset: 8; -*-
  2  * vim: noexpandtab sw=8 ts=8 sts=0:
  3  *
  4  * alloc.c
  5  *
  6  * Extent allocs and frees
  7  *
  8  * Copyright (C) 2002, 2004 Oracle.  All rights reserved.
  9  *
 10  * This program is free software; you can redistribute it and/or
 11  * modify it under the terms of the GNU General Public
 12  * License as published by the Free Software Foundation; either
 13  * version 2 of the License, or (at your option) any later version.
 14  *
 15  * This program is distributed in the hope that it will be useful,
 16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
 17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 18  * General Public License for more details.
 19  *
 20  * You should have received a copy of the GNU General Public
 21  * License along with this program; if not, write to the
 22  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 23  * Boston, MA 021110-1307, USA.
 24  */
 25 
 26 #include <linux/fs.h>
 27 #include <linux/types.h>
 28 #include <linux/slab.h>
 29 #include <linux/highmem.h>
 30 #include <linux/swap.h>
 31 #include <linux/quotaops.h>
 32 #include <linux/blkdev.h>
 33 #include <linux/sched/signal.h>
 34 
 35 #include <cluster/masklog.h>
 36 
 37 #include "ocfs2.h"
 38 
 39 #include "alloc.h"
 40 #include "aops.h"
 41 #include "blockcheck.h"
 42 #include "dlmglue.h"
 43 #include "extent_map.h"
 44 #include "inode.h"
 45 #include "journal.h"
 46 #include "localalloc.h"
 47 #include "suballoc.h"
 48 #include "sysfile.h"
 49 #include "file.h"
 50 #include "super.h"
 51 #include "uptodate.h"
 52 #include "xattr.h"
 53 #include "refcounttree.h"
 54 #include "ocfs2_trace.h"
 55 
 56 #include "buffer_head_io.h"
 57 
 58 enum ocfs2_contig_type {
 59         CONTIG_NONE = 0,
 60         CONTIG_LEFT,
 61         CONTIG_RIGHT,
 62         CONTIG_LEFTRIGHT,
 63 };
 64 
 65 static enum ocfs2_contig_type
 66         ocfs2_extent_rec_contig(struct super_block *sb,
 67                                 struct ocfs2_extent_rec *ext,
 68                                 struct ocfs2_extent_rec *insert_rec);
 69 /*
 70  * Operations for a specific extent tree type.
 71  *
 72  * To implement an on-disk btree (extent tree) type in ocfs2, add
 73  * an ocfs2_extent_tree_operations structure and the matching
 74  * ocfs2_init_<thingy>_extent_tree() function.  That's pretty much it
 75  * for the allocation portion of the extent tree.
 76  */
 77 struct ocfs2_extent_tree_operations {
 78         /*
 79          * last_eb_blk is the block number of the right most leaf extent
 80          * block.  Most on-disk structures containing an extent tree store
 81          * this value for fast access.  The ->eo_set_last_eb_blk() and
 82          * ->eo_get_last_eb_blk() operations access this value.  They are
 83          *  both required.
 84          */
 85         void (*eo_set_last_eb_blk)(struct ocfs2_extent_tree *et,
 86                                    u64 blkno);
 87         u64 (*eo_get_last_eb_blk)(struct ocfs2_extent_tree *et);
 88 
 89         /*
 90          * The on-disk structure usually keeps track of how many total
 91          * clusters are stored in this extent tree.  This function updates
 92          * that value.  new_clusters is the delta, and must be
 93          * added to the total.  Required.
 94          */
 95         void (*eo_update_clusters)(struct ocfs2_extent_tree *et,
 96                                    u32 new_clusters);
 97 
 98         /*
 99          * If this extent tree is supported by an extent map, insert
100          * a record into the map.
101          */
102         void (*eo_extent_map_insert)(struct ocfs2_extent_tree *et,
103                                      struct ocfs2_extent_rec *rec);
104 
105         /*
106          * If this extent tree is supported by an extent map, truncate the
107          * map to clusters,
108          */
109         void (*eo_extent_map_truncate)(struct ocfs2_extent_tree *et,
110                                        u32 clusters);
111 
112         /*
113          * If ->eo_insert_check() exists, it is called before rec is
114          * inserted into the extent tree.  It is optional.
115          */
116         int (*eo_insert_check)(struct ocfs2_extent_tree *et,
117                                struct ocfs2_extent_rec *rec);
118         int (*eo_sanity_check)(struct ocfs2_extent_tree *et);
119 
120         /*
121          * --------------------------------------------------------------
122          * The remaining are internal to ocfs2_extent_tree and don't have
123          * accessor functions
124          */
125 
126         /*
127          * ->eo_fill_root_el() takes et->et_object and sets et->et_root_el.
128          * It is required.
129          */
130         void (*eo_fill_root_el)(struct ocfs2_extent_tree *et);
131 
132         /*
133          * ->eo_fill_max_leaf_clusters sets et->et_max_leaf_clusters if
134          * it exists.  If it does not, et->et_max_leaf_clusters is set
135          * to 0 (unlimited).  Optional.
136          */
137         void (*eo_fill_max_leaf_clusters)(struct ocfs2_extent_tree *et);
138 
139         /*
140          * ->eo_extent_contig test whether the 2 ocfs2_extent_rec
141          * are contiguous or not. Optional. Don't need to set it if use
142          * ocfs2_extent_rec as the tree leaf.
143          */
144         enum ocfs2_contig_type
145                 (*eo_extent_contig)(struct ocfs2_extent_tree *et,
146                                     struct ocfs2_extent_rec *ext,
147                                     struct ocfs2_extent_rec *insert_rec);
148 };
149 
150 
151 /*
152  * Pre-declare ocfs2_dinode_et_ops so we can use it as a sanity check
153  * in the methods.
154  */
155 static u64 ocfs2_dinode_get_last_eb_blk(struct ocfs2_extent_tree *et);
156 static void ocfs2_dinode_set_last_eb_blk(struct ocfs2_extent_tree *et,
157                                          u64 blkno);
158 static void ocfs2_dinode_update_clusters(struct ocfs2_extent_tree *et,
159                                          u32 clusters);
160 static void ocfs2_dinode_extent_map_insert(struct ocfs2_extent_tree *et,
161                                            struct ocfs2_extent_rec *rec);
162 static void ocfs2_dinode_extent_map_truncate(struct ocfs2_extent_tree *et,
163                                              u32 clusters);
164 static int ocfs2_dinode_insert_check(struct ocfs2_extent_tree *et,
165                                      struct ocfs2_extent_rec *rec);
166 static int ocfs2_dinode_sanity_check(struct ocfs2_extent_tree *et);
167 static void ocfs2_dinode_fill_root_el(struct ocfs2_extent_tree *et);
168 
169 static int ocfs2_reuse_blk_from_dealloc(handle_t *handle,
170                                         struct ocfs2_extent_tree *et,
171                                         struct buffer_head **new_eb_bh,
172                                         int blk_wanted, int *blk_given);
173 static int ocfs2_is_dealloc_empty(struct ocfs2_extent_tree *et);
174 
175 static const struct ocfs2_extent_tree_operations ocfs2_dinode_et_ops = {
176         .eo_set_last_eb_blk     = ocfs2_dinode_set_last_eb_blk,
177         .eo_get_last_eb_blk     = ocfs2_dinode_get_last_eb_blk,
178         .eo_update_clusters     = ocfs2_dinode_update_clusters,
179         .eo_extent_map_insert   = ocfs2_dinode_extent_map_insert,
180         .eo_extent_map_truncate = ocfs2_dinode_extent_map_truncate,
181         .eo_insert_check        = ocfs2_dinode_insert_check,
182         .eo_sanity_check        = ocfs2_dinode_sanity_check,
183         .eo_fill_root_el        = ocfs2_dinode_fill_root_el,
184 };
185 
186 static void ocfs2_dinode_set_last_eb_blk(struct ocfs2_extent_tree *et,
187                                          u64 blkno)
188 {
189         struct ocfs2_dinode *di = et->et_object;
190 
191         BUG_ON(et->et_ops != &ocfs2_dinode_et_ops);
192         di->i_last_eb_blk = cpu_to_le64(blkno);
193 }
194 
195 static u64 ocfs2_dinode_get_last_eb_blk(struct ocfs2_extent_tree *et)
196 {
197         struct ocfs2_dinode *di = et->et_object;
198 
199         BUG_ON(et->et_ops != &ocfs2_dinode_et_ops);
200         return le64_to_cpu(di->i_last_eb_blk);
201 }
202 
203 static void ocfs2_dinode_update_clusters(struct ocfs2_extent_tree *et,
204                                          u32 clusters)
205 {
206         struct ocfs2_inode_info *oi = cache_info_to_inode(et->et_ci);
207         struct ocfs2_dinode *di = et->et_object;
208 
209         le32_add_cpu(&di->i_clusters, clusters);
210         spin_lock(&oi->ip_lock);
211         oi->ip_clusters = le32_to_cpu(di->i_clusters);
212         spin_unlock(&oi->ip_lock);
213 }
214 
215 static void ocfs2_dinode_extent_map_insert(struct ocfs2_extent_tree *et,
216                                            struct ocfs2_extent_rec *rec)
217 {
218         struct inode *inode = &cache_info_to_inode(et->et_ci)->vfs_inode;
219 
220         ocfs2_extent_map_insert_rec(inode, rec);
221 }
222 
223 static void ocfs2_dinode_extent_map_truncate(struct ocfs2_extent_tree *et,
224                                              u32 clusters)
225 {
226         struct inode *inode = &cache_info_to_inode(et->et_ci)->vfs_inode;
227 
228         ocfs2_extent_map_trunc(inode, clusters);
229 }
230 
231 static int ocfs2_dinode_insert_check(struct ocfs2_extent_tree *et,
232                                      struct ocfs2_extent_rec *rec)
233 {
234         struct ocfs2_inode_info *oi = cache_info_to_inode(et->et_ci);
235         struct ocfs2_super *osb = OCFS2_SB(oi->vfs_inode.i_sb);
236 
237         BUG_ON(oi->ip_dyn_features & OCFS2_INLINE_DATA_FL);
238         mlog_bug_on_msg(!ocfs2_sparse_alloc(osb) &&
239                         (oi->ip_clusters != le32_to_cpu(rec->e_cpos)),
240                         "Device %s, asking for sparse allocation: inode %llu, "
241                         "cpos %u, clusters %u\n",
242                         osb->dev_str,
243                         (unsigned long long)oi->ip_blkno,
244                         rec->e_cpos, oi->ip_clusters);
245 
246         return 0;
247 }
248 
249 static int ocfs2_dinode_sanity_check(struct ocfs2_extent_tree *et)
250 {
251         struct ocfs2_dinode *di = et->et_object;
252 
253         BUG_ON(et->et_ops != &ocfs2_dinode_et_ops);
254         BUG_ON(!OCFS2_IS_VALID_DINODE(di));
255 
256         return 0;
257 }
258 
259 static void ocfs2_dinode_fill_root_el(struct ocfs2_extent_tree *et)
260 {
261         struct ocfs2_dinode *di = et->et_object;
262 
263         et->et_root_el = &di->id2.i_list;
264 }
265 
266 
267 static void ocfs2_xattr_value_fill_root_el(struct ocfs2_extent_tree *et)
268 {
269         struct ocfs2_xattr_value_buf *vb = et->et_object;
270 
271         et->et_root_el = &vb->vb_xv->xr_list;
272 }
273 
274 static void ocfs2_xattr_value_set_last_eb_blk(struct ocfs2_extent_tree *et,
275                                               u64 blkno)
276 {
277         struct ocfs2_xattr_value_buf *vb = et->et_object;
278 
279         vb->vb_xv->xr_last_eb_blk = cpu_to_le64(blkno);
280 }
281 
282 static u64 ocfs2_xattr_value_get_last_eb_blk(struct ocfs2_extent_tree *et)
283 {
284         struct ocfs2_xattr_value_buf *vb = et->et_object;
285 
286         return le64_to_cpu(vb->vb_xv->xr_last_eb_blk);
287 }
288 
289 static void ocfs2_xattr_value_update_clusters(struct ocfs2_extent_tree *et,
290                                               u32 clusters)
291 {
292         struct ocfs2_xattr_value_buf *vb = et->et_object;
293 
294         le32_add_cpu(&vb->vb_xv->xr_clusters, clusters);
295 }
296 
297 static const struct ocfs2_extent_tree_operations ocfs2_xattr_value_et_ops = {
298         .eo_set_last_eb_blk     = ocfs2_xattr_value_set_last_eb_blk,
299         .eo_get_last_eb_blk     = ocfs2_xattr_value_get_last_eb_blk,
300         .eo_update_clusters     = ocfs2_xattr_value_update_clusters,
301         .eo_fill_root_el        = ocfs2_xattr_value_fill_root_el,
302 };
303 
304 static void ocfs2_xattr_tree_fill_root_el(struct ocfs2_extent_tree *et)
305 {
306         struct ocfs2_xattr_block *xb = et->et_object;
307 
308         et->et_root_el = &xb->xb_attrs.xb_root.xt_list;
309 }
310 
311 static void ocfs2_xattr_tree_fill_max_leaf_clusters(struct ocfs2_extent_tree *et)
312 {
313         struct super_block *sb = ocfs2_metadata_cache_get_super(et->et_ci);
314         et->et_max_leaf_clusters =
315                 ocfs2_clusters_for_bytes(sb, OCFS2_MAX_XATTR_TREE_LEAF_SIZE);
316 }
317 
318 static void ocfs2_xattr_tree_set_last_eb_blk(struct ocfs2_extent_tree *et,
319                                              u64 blkno)
320 {
321         struct ocfs2_xattr_block *xb = et->et_object;
322         struct ocfs2_xattr_tree_root *xt = &xb->xb_attrs.xb_root;
323 
324         xt->xt_last_eb_blk = cpu_to_le64(blkno);
325 }
326 
327 static u64 ocfs2_xattr_tree_get_last_eb_blk(struct ocfs2_extent_tree *et)
328 {
329         struct ocfs2_xattr_block *xb = et->et_object;
330         struct ocfs2_xattr_tree_root *xt = &xb->xb_attrs.xb_root;
331 
332         return le64_to_cpu(xt->xt_last_eb_blk);
333 }
334 
335 static void ocfs2_xattr_tree_update_clusters(struct ocfs2_extent_tree *et,
336                                              u32 clusters)
337 {
338         struct ocfs2_xattr_block *xb = et->et_object;
339 
340         le32_add_cpu(&xb->xb_attrs.xb_root.xt_clusters, clusters);
341 }
342 
343 static const struct ocfs2_extent_tree_operations ocfs2_xattr_tree_et_ops = {
344         .eo_set_last_eb_blk     = ocfs2_xattr_tree_set_last_eb_blk,
345         .eo_get_last_eb_blk     = ocfs2_xattr_tree_get_last_eb_blk,
346         .eo_update_clusters     = ocfs2_xattr_tree_update_clusters,
347         .eo_fill_root_el        = ocfs2_xattr_tree_fill_root_el,
348         .eo_fill_max_leaf_clusters = ocfs2_xattr_tree_fill_max_leaf_clusters,
349 };
350 
351 static void ocfs2_dx_root_set_last_eb_blk(struct ocfs2_extent_tree *et,
352                                           u64 blkno)
353 {
354         struct ocfs2_dx_root_block *dx_root = et->et_object;
355 
356         dx_root->dr_last_eb_blk = cpu_to_le64(blkno);
357 }
358 
359 static u64 ocfs2_dx_root_get_last_eb_blk(struct ocfs2_extent_tree *et)
360 {
361         struct ocfs2_dx_root_block *dx_root = et->et_object;
362 
363         return le64_to_cpu(dx_root->dr_last_eb_blk);
364 }
365 
366 static void ocfs2_dx_root_update_clusters(struct ocfs2_extent_tree *et,
367                                           u32 clusters)
368 {
369         struct ocfs2_dx_root_block *dx_root = et->et_object;
370 
371         le32_add_cpu(&dx_root->dr_clusters, clusters);
372 }
373 
374 static int ocfs2_dx_root_sanity_check(struct ocfs2_extent_tree *et)
375 {
376         struct ocfs2_dx_root_block *dx_root = et->et_object;
377 
378         BUG_ON(!OCFS2_IS_VALID_DX_ROOT(dx_root));
379 
380         return 0;
381 }
382 
383 static void ocfs2_dx_root_fill_root_el(struct ocfs2_extent_tree *et)
384 {
385         struct ocfs2_dx_root_block *dx_root = et->et_object;
386 
387         et->et_root_el = &dx_root->dr_list;
388 }
389 
390 static const struct ocfs2_extent_tree_operations ocfs2_dx_root_et_ops = {
391         .eo_set_last_eb_blk     = ocfs2_dx_root_set_last_eb_blk,
392         .eo_get_last_eb_blk     = ocfs2_dx_root_get_last_eb_blk,
393         .eo_update_clusters     = ocfs2_dx_root_update_clusters,
394         .eo_sanity_check        = ocfs2_dx_root_sanity_check,
395         .eo_fill_root_el        = ocfs2_dx_root_fill_root_el,
396 };
397 
398 static void ocfs2_refcount_tree_fill_root_el(struct ocfs2_extent_tree *et)
399 {
400         struct ocfs2_refcount_block *rb = et->et_object;
401 
402         et->et_root_el = &rb->rf_list;
403 }
404 
405 static void ocfs2_refcount_tree_set_last_eb_blk(struct ocfs2_extent_tree *et,
406                                                 u64 blkno)
407 {
408         struct ocfs2_refcount_block *rb = et->et_object;
409 
410         rb->rf_last_eb_blk = cpu_to_le64(blkno);
411 }
412 
413 static u64 ocfs2_refcount_tree_get_last_eb_blk(struct ocfs2_extent_tree *et)
414 {
415         struct ocfs2_refcount_block *rb = et->et_object;
416 
417         return le64_to_cpu(rb->rf_last_eb_blk);
418 }
419 
420 static void ocfs2_refcount_tree_update_clusters(struct ocfs2_extent_tree *et,
421                                                 u32 clusters)
422 {
423         struct ocfs2_refcount_block *rb = et->et_object;
424 
425         le32_add_cpu(&rb->rf_clusters, clusters);
426 }
427 
428 static enum ocfs2_contig_type
429 ocfs2_refcount_tree_extent_contig(struct ocfs2_extent_tree *et,
430                                   struct ocfs2_extent_rec *ext,
431                                   struct ocfs2_extent_rec *insert_rec)
432 {
433         return CONTIG_NONE;
434 }
435 
436 static const struct ocfs2_extent_tree_operations ocfs2_refcount_tree_et_ops = {
437         .eo_set_last_eb_blk     = ocfs2_refcount_tree_set_last_eb_blk,
438         .eo_get_last_eb_blk     = ocfs2_refcount_tree_get_last_eb_blk,
439         .eo_update_clusters     = ocfs2_refcount_tree_update_clusters,
440         .eo_fill_root_el        = ocfs2_refcount_tree_fill_root_el,
441         .eo_extent_contig       = ocfs2_refcount_tree_extent_contig,
442 };
443 
444 static void __ocfs2_init_extent_tree(struct ocfs2_extent_tree *et,
445                                      struct ocfs2_caching_info *ci,
446                                      struct buffer_head *bh,
447                                      ocfs2_journal_access_func access,
448                                      void *obj,
449                                      const struct ocfs2_extent_tree_operations *ops)
450 {
451         et->et_ops = ops;
452         et->et_root_bh = bh;
453         et->et_ci = ci;
454         et->et_root_journal_access = access;
455         if (!obj)
456                 obj = (void *)bh->b_data;
457         et->et_object = obj;
458         et->et_dealloc = NULL;
459 
460         et->et_ops->eo_fill_root_el(et);
461         if (!et->et_ops->eo_fill_max_leaf_clusters)
462                 et->et_max_leaf_clusters = 0;
463         else
464                 et->et_ops->eo_fill_max_leaf_clusters(et);
465 }
466 
467 void ocfs2_init_dinode_extent_tree(struct ocfs2_extent_tree *et,
468                                    struct ocfs2_caching_info *ci,
469                                    struct buffer_head *bh)
470 {
471         __ocfs2_init_extent_tree(et, ci, bh, ocfs2_journal_access_di,
472                                  NULL, &ocfs2_dinode_et_ops);
473 }
474 
475 void ocfs2_init_xattr_tree_extent_tree(struct ocfs2_extent_tree *et,
476                                        struct ocfs2_caching_info *ci,
477                                        struct buffer_head *bh)
478 {
479         __ocfs2_init_extent_tree(et, ci, bh, ocfs2_journal_access_xb,
480                                  NULL, &ocfs2_xattr_tree_et_ops);
481 }
482 
483 void ocfs2_init_xattr_value_extent_tree(struct ocfs2_extent_tree *et,
484                                         struct ocfs2_caching_info *ci,
485                                         struct ocfs2_xattr_value_buf *vb)
486 {
487         __ocfs2_init_extent_tree(et, ci, vb->vb_bh, vb->vb_access, vb,
488                                  &ocfs2_xattr_value_et_ops);
489 }
490 
491 void ocfs2_init_dx_root_extent_tree(struct ocfs2_extent_tree *et,
492                                     struct ocfs2_caching_info *ci,
493                                     struct buffer_head *bh)
494 {
495         __ocfs2_init_extent_tree(et, ci, bh, ocfs2_journal_access_dr,
496                                  NULL, &ocfs2_dx_root_et_ops);
497 }
498 
499 void ocfs2_init_refcount_extent_tree(struct ocfs2_extent_tree *et,
500                                      struct ocfs2_caching_info *ci,
501                                      struct buffer_head *bh)
502 {
503         __ocfs2_init_extent_tree(et, ci, bh, ocfs2_journal_access_rb,
504                                  NULL, &ocfs2_refcount_tree_et_ops);
505 }
506 
507 static inline void ocfs2_et_set_last_eb_blk(struct ocfs2_extent_tree *et,
508                                             u64 new_last_eb_blk)
509 {
510         et->et_ops->eo_set_last_eb_blk(et, new_last_eb_blk);
511 }
512 
513 static inline u64 ocfs2_et_get_last_eb_blk(struct ocfs2_extent_tree *et)
514 {
515         return et->et_ops->eo_get_last_eb_blk(et);
516 }
517 
518 static inline void ocfs2_et_update_clusters(struct ocfs2_extent_tree *et,
519                                             u32 clusters)
520 {
521         et->et_ops->eo_update_clusters(et, clusters);
522 }
523 
524 static inline void ocfs2_et_extent_map_insert(struct ocfs2_extent_tree *et,
525                                               struct ocfs2_extent_rec *rec)
526 {
527         if (et->et_ops->eo_extent_map_insert)
528                 et->et_ops->eo_extent_map_insert(et, rec);
529 }
530 
531 static inline void ocfs2_et_extent_map_truncate(struct ocfs2_extent_tree *et,
532                                                 u32 clusters)
533 {
534         if (et->et_ops->eo_extent_map_truncate)
535                 et->et_ops->eo_extent_map_truncate(et, clusters);
536 }
537 
538 static inline int ocfs2_et_root_journal_access(handle_t *handle,
539                                                struct ocfs2_extent_tree *et,
540                                                int type)
541 {
542         return et->et_root_journal_access(handle, et->et_ci, et->et_root_bh,
543                                           type);
544 }
545 
546 static inline enum ocfs2_contig_type
547         ocfs2_et_extent_contig(struct ocfs2_extent_tree *et,
548                                struct ocfs2_extent_rec *rec,
549                                struct ocfs2_extent_rec *insert_rec)
550 {
551         if (et->et_ops->eo_extent_contig)
552                 return et->et_ops->eo_extent_contig(et, rec, insert_rec);
553 
554         return ocfs2_extent_rec_contig(
555                                 ocfs2_metadata_cache_get_super(et->et_ci),
556                                 rec, insert_rec);
557 }
558 
559 static inline int ocfs2_et_insert_check(struct ocfs2_extent_tree *et,
560                                         struct ocfs2_extent_rec *rec)
561 {
562         int ret = 0;
563 
564         if (et->et_ops->eo_insert_check)
565                 ret = et->et_ops->eo_insert_check(et, rec);
566         return ret;
567 }
568 
569 static inline int ocfs2_et_sanity_check(struct ocfs2_extent_tree *et)
570 {
571         int ret = 0;
572 
573         if (et->et_ops->eo_sanity_check)
574                 ret = et->et_ops->eo_sanity_check(et);
575         return ret;
576 }
577 
578 static int ocfs2_cache_extent_block_free(struct ocfs2_cached_dealloc_ctxt *ctxt,
579                                          struct ocfs2_extent_block *eb);
580 static void ocfs2_adjust_rightmost_records(handle_t *handle,
581                                            struct ocfs2_extent_tree *et,
582                                            struct ocfs2_path *path,
583                                            struct ocfs2_extent_rec *insert_rec);
584 /*
585  * Reset the actual path elements so that we can re-use the structure
586  * to build another path. Generally, this involves freeing the buffer
587  * heads.
588  */
589 void ocfs2_reinit_path(struct ocfs2_path *path, int keep_root)
590 {
591         int i, start = 0, depth = 0;
592         struct ocfs2_path_item *node;
593 
594         if (keep_root)
595                 start = 1;
596 
597         for(i = start; i < path_num_items(path); i++) {
598                 node = &path->p_node[i];
599 
600                 brelse(node->bh);
601                 node->bh = NULL;
602                 node->el = NULL;
603         }
604 
605         /*
606          * Tree depth may change during truncate, or insert. If we're
607          * keeping the root extent list, then make sure that our path
608          * structure reflects the proper depth.
609          */
610         if (keep_root)
611                 depth = le16_to_cpu(path_root_el(path)->l_tree_depth);
612         else
613                 path_root_access(path) = NULL;
614 
615         path->p_tree_depth = depth;
616 }
617 
618 void ocfs2_free_path(struct ocfs2_path *path)
619 {
620         if (path) {
621                 ocfs2_reinit_path(path, 0);
622                 kfree(path);
623         }
624 }
625 
626 /*
627  * All the elements of src into dest. After this call, src could be freed
628  * without affecting dest.
629  *
630  * Both paths should have the same root. Any non-root elements of dest
631  * will be freed.
632  */
633 static void ocfs2_cp_path(struct ocfs2_path *dest, struct ocfs2_path *src)
634 {
635         int i;
636 
637         BUG_ON(path_root_bh(dest) != path_root_bh(src));
638         BUG_ON(path_root_el(dest) != path_root_el(src));
639         BUG_ON(path_root_access(dest) != path_root_access(src));
640 
641         ocfs2_reinit_path(dest, 1);
642 
643         for(i = 1; i < OCFS2_MAX_PATH_DEPTH; i++) {
644                 dest->p_node[i].bh = src->p_node[i].bh;
645                 dest->p_node[i].el = src->p_node[i].el;
646 
647                 if (dest->p_node[i].bh)
648                         get_bh(dest->p_node[i].bh);
649         }
650 }
651 
652 /*
653  * Make the *dest path the same as src and re-initialize src path to
654  * have a root only.
655  */
656 static void ocfs2_mv_path(struct ocfs2_path *dest, struct ocfs2_path *src)
657 {
658         int i;
659 
660         BUG_ON(path_root_bh(dest) != path_root_bh(src));
661         BUG_ON(path_root_access(dest) != path_root_access(src));
662 
663         for(i = 1; i < OCFS2_MAX_PATH_DEPTH; i++) {
664                 brelse(dest->p_node[i].bh);
665 
666                 dest->p_node[i].bh = src->p_node[i].bh;
667                 dest->p_node[i].el = src->p_node[i].el;
668 
669                 src->p_node[i].bh = NULL;
670                 src->p_node[i].el = NULL;
671         }
672 }
673 
674 /*
675  * Insert an extent block at given index.
676  *
677  * This will not take an additional reference on eb_bh.
678  */
679 static inline void ocfs2_path_insert_eb(struct ocfs2_path *path, int index,
680                                         struct buffer_head *eb_bh)
681 {
682         struct ocfs2_extent_block *eb = (struct ocfs2_extent_block *)eb_bh->b_data;
683 
684         /*
685          * Right now, no root bh is an extent block, so this helps
686          * catch code errors with dinode trees. The assertion can be
687          * safely removed if we ever need to insert extent block
688          * structures at the root.
689          */
690         BUG_ON(index == 0);
691 
692         path->p_node[index].bh = eb_bh;
693         path->p_node[index].el = &eb->h_list;
694 }
695 
696 static struct ocfs2_path *ocfs2_new_path(struct buffer_head *root_bh,
697                                          struct ocfs2_extent_list *root_el,
698                                          ocfs2_journal_access_func access)
699 {
700         struct ocfs2_path *path;
701 
702         BUG_ON(le16_to_cpu(root_el->l_tree_depth) >= OCFS2_MAX_PATH_DEPTH);
703 
704         path = kzalloc(sizeof(*path), GFP_NOFS);
705         if (path) {
706                 path->p_tree_depth = le16_to_cpu(root_el->l_tree_depth);
707                 get_bh(root_bh);
708                 path_root_bh(path) = root_bh;
709                 path_root_el(path) = root_el;
710                 path_root_access(path) = access;
711         }
712 
713         return path;
714 }
715 
716 struct ocfs2_path *ocfs2_new_path_from_path(struct ocfs2_path *path)
717 {
718         return ocfs2_new_path(path_root_bh(path), path_root_el(path),
719                               path_root_access(path));
720 }
721 
722 struct ocfs2_path *ocfs2_new_path_from_et(struct ocfs2_extent_tree *et)
723 {
724         return ocfs2_new_path(et->et_root_bh, et->et_root_el,
725                               et->et_root_journal_access);
726 }
727 
728 /*
729  * Journal the buffer at depth idx.  All idx>0 are extent_blocks,
730  * otherwise it's the root_access function.
731  *
732  * I don't like the way this function's name looks next to
733  * ocfs2_journal_access_path(), but I don't have a better one.
734  */
735 int ocfs2_path_bh_journal_access(handle_t *handle,
736                                  struct ocfs2_caching_info *ci,
737                                  struct ocfs2_path *path,
738                                  int idx)
739 {
740         ocfs2_journal_access_func access = path_root_access(path);
741 
742         if (!access)
743                 access = ocfs2_journal_access;
744 
745         if (idx)
746                 access = ocfs2_journal_access_eb;
747 
748         return access(handle, ci, path->p_node[idx].bh,
749                       OCFS2_JOURNAL_ACCESS_WRITE);
750 }
751 
752 /*
753  * Convenience function to journal all components in a path.
754  */
755 int ocfs2_journal_access_path(struct ocfs2_caching_info *ci,
756                               handle_t *handle,
757                               struct ocfs2_path *path)
758 {
759         int i, ret = 0;
760 
761         if (!path)
762                 goto out;
763 
764         for(i = 0; i < path_num_items(path); i++) {
765                 ret = ocfs2_path_bh_journal_access(handle, ci, path, i);
766                 if (ret < 0) {
767                         mlog_errno(ret);
768                         goto out;
769                 }
770         }
771 
772 out:
773         return ret;
774 }
775 
776 /*
777  * Return the index of the extent record which contains cluster #v_cluster.
778  * -1 is returned if it was not found.
779  *
780  * Should work fine on interior and exterior nodes.
781  */
782 int ocfs2_search_extent_list(struct ocfs2_extent_list *el, u32 v_cluster)
783 {
784         int ret = -1;
785         int i;
786         struct ocfs2_extent_rec *rec;
787         u32 rec_end, rec_start, clusters;
788 
789         for(i = 0; i < le16_to_cpu(el->l_next_free_rec); i++) {
790                 rec = &el->l_recs[i];
791 
792                 rec_start = le32_to_cpu(rec->e_cpos);
793                 clusters = ocfs2_rec_clusters(el, rec);
794 
795                 rec_end = rec_start + clusters;
796 
797                 if (v_cluster >= rec_start && v_cluster < rec_end) {
798                         ret = i;
799                         break;
800                 }
801         }
802 
803         return ret;
804 }
805 
806 /*
807  * NOTE: ocfs2_block_extent_contig(), ocfs2_extents_adjacent() and
808  * ocfs2_extent_rec_contig only work properly against leaf nodes!
809  */
810 static int ocfs2_block_extent_contig(struct super_block *sb,
811                                      struct ocfs2_extent_rec *ext,
812                                      u64 blkno)
813 {
814         u64 blk_end = le64_to_cpu(ext->e_blkno);
815 
816         blk_end += ocfs2_clusters_to_blocks(sb,
817                                     le16_to_cpu(ext->e_leaf_clusters));
818 
819         return blkno == blk_end;
820 }
821 
822 static int ocfs2_extents_adjacent(struct ocfs2_extent_rec *left,
823                                   struct ocfs2_extent_rec *right)
824 {
825         u32 left_range;
826 
827         left_range = le32_to_cpu(left->e_cpos) +
828                 le16_to_cpu(left->e_leaf_clusters);
829 
830         return (left_range == le32_to_cpu(right->e_cpos));
831 }
832 
833 static enum ocfs2_contig_type
834         ocfs2_extent_rec_contig(struct super_block *sb,
835                                 struct ocfs2_extent_rec *ext,
836                                 struct ocfs2_extent_rec *insert_rec)
837 {
838         u64 blkno = le64_to_cpu(insert_rec->e_blkno);
839 
840         /*
841          * Refuse to coalesce extent records with different flag
842          * fields - we don't want to mix unwritten extents with user
843          * data.
844          */
845         if (ext->e_flags != insert_rec->e_flags)
846                 return CONTIG_NONE;
847 
848         if (ocfs2_extents_adjacent(ext, insert_rec) &&
849             ocfs2_block_extent_contig(sb, ext, blkno))
850                         return CONTIG_RIGHT;
851 
852         blkno = le64_to_cpu(ext->e_blkno);
853         if (ocfs2_extents_adjacent(insert_rec, ext) &&
854             ocfs2_block_extent_contig(sb, insert_rec, blkno))
855                 return CONTIG_LEFT;
856 
857         return CONTIG_NONE;
858 }
859 
860 /*
861  * NOTE: We can have pretty much any combination of contiguousness and
862  * appending.
863  *
864  * The usefulness of APPEND_TAIL is more in that it lets us know that
865  * we'll have to update the path to that leaf.
866  */
867 enum ocfs2_append_type {
868         APPEND_NONE = 0,
869         APPEND_TAIL,
870 };
871 
872 enum ocfs2_split_type {
873         SPLIT_NONE = 0,
874         SPLIT_LEFT,
875         SPLIT_RIGHT,
876 };
877 
878 struct ocfs2_insert_type {
879         enum ocfs2_split_type   ins_split;
880         enum ocfs2_append_type  ins_appending;
881         enum ocfs2_contig_type  ins_contig;
882         int                     ins_contig_index;
883         int                     ins_tree_depth;
884 };
885 
886 struct ocfs2_merge_ctxt {
887         enum ocfs2_contig_type  c_contig_type;
888         int                     c_has_empty_extent;
889         int                     c_split_covers_rec;
890 };
891 
892 static int ocfs2_validate_extent_block(struct super_block *sb,
893                                        struct buffer_head *bh)
894 {
895         int rc;
896         struct ocfs2_extent_block *eb =
897                 (struct ocfs2_extent_block *)bh->b_data;
898 
899         trace_ocfs2_validate_extent_block((unsigned long long)bh->b_blocknr);
900 
901         BUG_ON(!buffer_uptodate(bh));
902 
903         /*
904          * If the ecc fails, we return the error but otherwise
905          * leave the filesystem running.  We know any error is
906          * local to this block.
907          */
908         rc = ocfs2_validate_meta_ecc(sb, bh->b_data, &eb->h_check);
909         if (rc) {
910                 mlog(ML_ERROR, "Checksum failed for extent block %llu\n",
911                      (unsigned long long)bh->b_blocknr);
912                 return rc;
913         }
914 
915         /*
916          * Errors after here are fatal.
917          */
918 
919         if (!OCFS2_IS_VALID_EXTENT_BLOCK(eb)) {
920                 rc = ocfs2_error(sb,
921                                  "Extent block #%llu has bad signature %.*s\n",
922                                  (unsigned long long)bh->b_blocknr, 7,
923                                  eb->h_signature);
924                 goto bail;
925         }
926 
927         if (le64_to_cpu(eb->h_blkno) != bh->b_blocknr) {
928                 rc = ocfs2_error(sb,
929                                  "Extent block #%llu has an invalid h_blkno of %llu\n",
930                                  (unsigned long long)bh->b_blocknr,
931                                  (unsigned long long)le64_to_cpu(eb->h_blkno));
932                 goto bail;
933         }
934 
935         if (le32_to_cpu(eb->h_fs_generation) != OCFS2_SB(sb)->fs_generation)
936                 rc = ocfs2_error(sb,
937                                  "Extent block #%llu has an invalid h_fs_generation of #%u\n",
938                                  (unsigned long long)bh->b_blocknr,
939                                  le32_to_cpu(eb->h_fs_generation));
940 bail:
941         return rc;
942 }
943 
944 int ocfs2_read_extent_block(struct ocfs2_caching_info *ci, u64 eb_blkno,
945                             struct buffer_head **bh)
946 {
947         int rc;
948         struct buffer_head *tmp = *bh;
949 
950         rc = ocfs2_read_block(ci, eb_blkno, &tmp,
951                               ocfs2_validate_extent_block);
952 
953         /* If ocfs2_read_block() got us a new bh, pass it up. */
954         if (!rc && !*bh)
955                 *bh = tmp;
956 
957         return rc;
958 }
959 
960 
961 /*
962  * How many free extents have we got before we need more meta data?
963  */
964 int ocfs2_num_free_extents(struct ocfs2_extent_tree *et)
965 {
966         int retval;
967         struct ocfs2_extent_list *el = NULL;
968         struct ocfs2_extent_block *eb;
969         struct buffer_head *eb_bh = NULL;
970         u64 last_eb_blk = 0;
971 
972         el = et->et_root_el;
973         last_eb_blk = ocfs2_et_get_last_eb_blk(et);
974 
975         if (last_eb_blk) {
976                 retval = ocfs2_read_extent_block(et->et_ci, last_eb_blk,
977                                                  &eb_bh);
978                 if (retval < 0) {
979                         mlog_errno(retval);
980                         goto bail;
981                 }
982                 eb = (struct ocfs2_extent_block *) eb_bh->b_data;
983                 el = &eb->h_list;
984         }
985 
986         BUG_ON(el->l_tree_depth != 0);
987 
988         retval = le16_to_cpu(el->l_count) - le16_to_cpu(el->l_next_free_rec);
989 bail:
990         brelse(eb_bh);
991 
992         trace_ocfs2_num_free_extents(retval);
993         return retval;
994 }
995 
996 /* expects array to already be allocated
997  *
998  * sets h_signature, h_blkno, h_suballoc_bit, h_suballoc_slot, and
999  * l_count for you
1000  */
1001 static int ocfs2_create_new_meta_bhs(handle_t *handle,
1002                                      struct ocfs2_extent_tree *et,
1003                                      int wanted,
1004                                      struct ocfs2_alloc_context *meta_ac,
1005                                      struct buffer_head *bhs[])
1006 {
1007         int count, status, i;
1008         u16 suballoc_bit_start;
1009         u32 num_got;
1010         u64 suballoc_loc, first_blkno;
1011         struct ocfs2_super *osb =
1012                 OCFS2_SB(ocfs2_metadata_cache_get_super(et->et_ci));
1013         struct ocfs2_extent_block *eb;
1014 
1015         count = 0;
1016         while (count < wanted) {
1017                 status = ocfs2_claim_metadata(handle,
1018                                               meta_ac,
1019                                               wanted - count,
1020                                               &suballoc_loc,
1021                                               &suballoc_bit_start,
1022                                               &num_got,
1023                                               &first_blkno);
1024                 if (status < 0) {
1025                         mlog_errno(status);
1026                         goto bail;
1027                 }
1028 
1029                 for(i = count;  i < (num_got + count); i++) {
1030                         bhs[i] = sb_getblk(osb->sb, first_blkno);
1031                         if (bhs[i] == NULL) {
1032                                 status = -ENOMEM;
1033                                 mlog_errno(status);
1034                                 goto bail;
1035                         }
1036                         ocfs2_set_new_buffer_uptodate(et->et_ci, bhs[i]);
1037 
1038                         status = ocfs2_journal_access_eb(handle, et->et_ci,
1039                                                          bhs[i],
1040                                                          OCFS2_JOURNAL_ACCESS_CREATE);
1041                         if (status < 0) {
1042                                 mlog_errno(status);
1043                                 goto bail;
1044                         }
1045 
1046                         memset(bhs[i]->b_data, 0, osb->sb->s_blocksize);
1047                         eb = (struct ocfs2_extent_block *) bhs[i]->b_data;
1048                         /* Ok, setup the minimal stuff here. */
1049                         strcpy(eb->h_signature, OCFS2_EXTENT_BLOCK_SIGNATURE);
1050                         eb->h_blkno = cpu_to_le64(first_blkno);
1051                         eb->h_fs_generation = cpu_to_le32(osb->fs_generation);
1052                         eb->h_suballoc_slot =
1053                                 cpu_to_le16(meta_ac->ac_alloc_slot);
1054                         eb->h_suballoc_loc = cpu_to_le64(suballoc_loc);
1055                         eb->h_suballoc_bit = cpu_to_le16(suballoc_bit_start);
1056                         eb->h_list.l_count =
1057                                 cpu_to_le16(ocfs2_extent_recs_per_eb(osb->sb));
1058 
1059                         suballoc_bit_start++;
1060                         first_blkno++;
1061 
1062                         /* We'll also be dirtied by the caller, so
1063                          * this isn't absolutely necessary. */
1064                         ocfs2_journal_dirty(handle, bhs[i]);
1065                 }
1066 
1067                 count += num_got;
1068         }
1069 
1070         status = 0;
1071 bail:
1072         if (status < 0) {
1073                 for(i = 0; i < wanted; i++) {
1074                         brelse(bhs[i]);
1075                         bhs[i] = NULL;
1076                 }
1077                 mlog_errno(status);
1078         }
1079         return status;
1080 }
1081 
1082 /*
1083  * Helper function for ocfs2_add_branch() and ocfs2_shift_tree_depth().
1084  *
1085  * Returns the sum of the rightmost extent rec logical offset and
1086  * cluster count.
1087  *
1088  * ocfs2_add_branch() uses this to determine what logical cluster
1089  * value should be populated into the leftmost new branch records.
1090  *
1091  * ocfs2_shift_tree_depth() uses this to determine the # clusters
1092  * value for the new topmost tree record.
1093  */
1094 static inline u32 ocfs2_sum_rightmost_rec(struct ocfs2_extent_list  *el)
1095 {
1096         int i;
1097 
1098         i = le16_to_cpu(el->l_next_free_rec) - 1;
1099 
1100         return le32_to_cpu(el->l_recs[i].e_cpos) +
1101                 ocfs2_rec_clusters(el, &el->l_recs[i]);
1102 }
1103 
1104 /*
1105  * Change range of the branches in the right most path according to the leaf
1106  * extent block's rightmost record.
1107  */
1108 static int ocfs2_adjust_rightmost_branch(handle_t *handle,
1109                                          struct ocfs2_extent_tree *et)
1110 {
1111         int status;
1112         struct ocfs2_path *path = NULL;
1113         struct ocfs2_extent_list *el;
1114         struct ocfs2_extent_rec *rec;
1115 
1116         path = ocfs2_new_path_from_et(et);
1117         if (!path) {
1118                 status = -ENOMEM;
1119                 return status;
1120         }
1121 
1122         status = ocfs2_find_path(et->et_ci, path, UINT_MAX);
1123         if (status < 0) {
1124                 mlog_errno(status);
1125                 goto out;
1126         }
1127 
1128         status = ocfs2_extend_trans(handle, path_num_items(path));
1129         if (status < 0) {
1130                 mlog_errno(status);
1131                 goto out;
1132         }
1133 
1134         status = ocfs2_journal_access_path(et->et_ci, handle, path);
1135         if (status < 0) {
1136                 mlog_errno(status);
1137                 goto out;
1138         }
1139 
1140         el = path_leaf_el(path);
1141         rec = &el->l_recs[le16_to_cpu(el->l_next_free_rec) - 1];
1142 
1143         ocfs2_adjust_rightmost_records(handle, et, path, rec);
1144 
1145 out:
1146         ocfs2_free_path(path);
1147         return status;
1148 }
1149 
1150 /*
1151  * Add an entire tree branch to our inode. eb_bh is the extent block
1152  * to start at, if we don't want to start the branch at the root
1153  * structure.
1154  *
1155  * last_eb_bh is required as we have to update it's next_leaf pointer
1156  * for the new last extent block.
1157  *
1158  * the new branch will be 'empty' in the sense that every block will
1159  * contain a single record with cluster count == 0.
1160  */
1161 static int ocfs2_add_branch(handle_t *handle,
1162                             struct ocfs2_extent_tree *et,
1163                             struct buffer_head *eb_bh,
1164                             struct buffer_head **last_eb_bh,
1165                             struct ocfs2_alloc_context *meta_ac)
1166 {
1167         int status, new_blocks, i, block_given = 0;
1168         u64 next_blkno, new_last_eb_blk;
1169         struct buffer_head *bh;
1170         struct buffer_head **new_eb_bhs = NULL;
1171         struct ocfs2_extent_block *eb;
1172         struct ocfs2_extent_list  *eb_el;
1173         struct ocfs2_extent_list  *el;
1174         u32 new_cpos, root_end;
1175 
1176         BUG_ON(!last_eb_bh || !*last_eb_bh);
1177 
1178         if (eb_bh) {
1179                 eb = (struct ocfs2_extent_block *) eb_bh->b_data;
1180                 el = &eb->h_list;
1181         } else
1182                 el = et->et_root_el;
1183 
1184         /* we never add a branch to a leaf. */
1185         BUG_ON(!el->l_tree_depth);
1186 
1187         new_blocks = le16_to_cpu(el->l_tree_depth);
1188 
1189         eb = (struct ocfs2_extent_block *)(*last_eb_bh)->b_data;
1190         new_cpos = ocfs2_sum_rightmost_rec(&eb->h_list);
1191         root_end = ocfs2_sum_rightmost_rec(et->et_root_el);
1192 
1193         /*
1194          * If there is a gap before the root end and the real end
1195          * of the righmost leaf block, we need to remove the gap
1196          * between new_cpos and root_end first so that the tree
1197          * is consistent after we add a new branch(it will start
1198          * from new_cpos).
1199          */
1200         if (root_end > new_cpos) {
1201                 trace_ocfs2_adjust_rightmost_branch(
1202                         (unsigned long long)
1203                         ocfs2_metadata_cache_owner(et->et_ci),
1204                         root_end, new_cpos);
1205 
1206                 status = ocfs2_adjust_rightmost_branch(handle, et);
1207                 if (status) {
1208                         mlog_errno(status);
1209                         goto bail;
1210                 }
1211         }
1212 
1213         /* allocate the number of new eb blocks we need */
1214         new_eb_bhs = kcalloc(new_blocks, sizeof(struct buffer_head *),
1215                              GFP_KERNEL);
1216         if (!new_eb_bhs) {
1217                 status = -ENOMEM;
1218                 mlog_errno(status);
1219                 goto bail;
1220         }
1221 
1222         /* Firstyly, try to reuse dealloc since we have already estimated how
1223          * many extent blocks we may use.
1224          */
1225         if (!ocfs2_is_dealloc_empty(et)) {
1226                 status = ocfs2_reuse_blk_from_dealloc(handle, et,
1227                                                       new_eb_bhs, new_blocks,
1228                                                       &block_given);
1229                 if (status < 0) {
1230                         mlog_errno(status);
1231                         goto bail;
1232                 }
1233         }
1234 
1235         BUG_ON(block_given > new_blocks);
1236 
1237         if (block_given < new_blocks) {
1238                 BUG_ON(!meta_ac);
1239                 status = ocfs2_create_new_meta_bhs(handle, et,
1240                                                    new_blocks - block_given,
1241                                                    meta_ac,
1242                                                    &new_eb_bhs[block_given]);
1243                 if (status < 0) {
1244                         mlog_errno(status);
1245                         goto bail;
1246                 }
1247         }
1248 
1249         /* Note: new_eb_bhs[new_blocks - 1] is the guy which will be
1250          * linked with the rest of the tree.
1251          * conversly, new_eb_bhs[0] is the new bottommost leaf.
1252          *
1253          * when we leave the loop, new_last_eb_blk will point to the
1254          * newest leaf, and next_blkno will point to the topmost extent
1255          * block. */
1256         next_blkno = new_last_eb_blk = 0;
1257         for(i = 0; i < new_blocks; i++) {
1258                 bh = new_eb_bhs[i];
1259                 eb = (struct ocfs2_extent_block *) bh->b_data;
1260                 /* ocfs2_create_new_meta_bhs() should create it right! */
1261                 BUG_ON(!OCFS2_IS_VALID_EXTENT_BLOCK(eb));
1262                 eb_el = &eb->h_list;
1263 
1264                 status = ocfs2_journal_access_eb(handle, et->et_ci, bh,
1265                                                  OCFS2_JOURNAL_ACCESS_CREATE);
1266                 if (status < 0) {
1267                         mlog_errno(status);
1268                         goto bail;
1269                 }
1270 
1271                 eb->h_next_leaf_blk = 0;
1272                 eb_el->l_tree_depth = cpu_to_le16(i);
1273                 eb_el->l_next_free_rec = cpu_to_le16(1);
1274                 /*
1275                  * This actually counts as an empty extent as
1276                  * c_clusters == 0
1277                  */
1278                 eb_el->l_recs[0].e_cpos = cpu_to_le32(new_cpos);
1279                 eb_el->l_recs[0].e_blkno = cpu_to_le64(next_blkno);
1280                 /*
1281                  * eb_el isn't always an interior node, but even leaf
1282                  * nodes want a zero'd flags and reserved field so
1283                  * this gets the whole 32 bits regardless of use.
1284                  */
1285                 eb_el->l_recs[0].e_int_clusters = cpu_to_le32(0);
1286                 if (!eb_el->l_tree_depth)
1287                         new_last_eb_blk = le64_to_cpu(eb->h_blkno);
1288 
1289                 ocfs2_journal_dirty(handle, bh);
1290                 next_blkno = le64_to_cpu(eb->h_blkno);
1291         }
1292 
1293         /* This is a bit hairy. We want to update up to three blocks
1294          * here without leaving any of them in an inconsistent state
1295          * in case of error. We don't have to worry about
1296          * journal_dirty erroring as it won't unless we've aborted the
1297          * handle (in which case we would never be here) so reserving
1298          * the write with journal_access is all we need to do. */
1299         status = ocfs2_journal_access_eb(handle, et->et_ci, *last_eb_bh,
1300                                          OCFS2_JOURNAL_ACCESS_WRITE);
1301         if (status < 0) {
1302                 mlog_errno(status);
1303                 goto bail;
1304         }
1305         status = ocfs2_et_root_journal_access(handle, et,
1306                                               OCFS2_JOURNAL_ACCESS_WRITE);
1307         if (status < 0) {
1308                 mlog_errno(status);
1309                 goto bail;
1310         }
1311         if (eb_bh) {
1312                 status = ocfs2_journal_access_eb(handle, et->et_ci, eb_bh,
1313                                                  OCFS2_JOURNAL_ACCESS_WRITE);
1314                 if (status < 0) {
1315                         mlog_errno(status);
1316                         goto bail;
1317                 }
1318         }
1319 
1320         /* Link the new branch into the rest of the tree (el will
1321          * either be on the root_bh, or the extent block passed in. */
1322         i = le16_to_cpu(el->l_next_free_rec);
1323         el->l_recs[i].e_blkno = cpu_to_le64(next_blkno);
1324         el->l_recs[i].e_cpos = cpu_to_le32(new_cpos);
1325         el->l_recs[i].e_int_clusters = 0;
1326         le16_add_cpu(&el->l_next_free_rec, 1);
1327 
1328         /* fe needs a new last extent block pointer, as does the
1329          * next_leaf on the previously last-extent-block. */
1330         ocfs2_et_set_last_eb_blk(et, new_last_eb_blk);
1331 
1332         eb = (struct ocfs2_extent_block *) (*last_eb_bh)->b_data;
1333         eb->h_next_leaf_blk = cpu_to_le64(new_last_eb_blk);
1334 
1335         ocfs2_journal_dirty(handle, *last_eb_bh);
1336         ocfs2_journal_dirty(handle, et->et_root_bh);
1337         if (eb_bh)
1338                 ocfs2_journal_dirty(handle, eb_bh);
1339 
1340         /*
1341          * Some callers want to track the rightmost leaf so pass it
1342          * back here.
1343          */
1344         brelse(*last_eb_bh);
1345         get_bh(new_eb_bhs[0]);
1346         *last_eb_bh = new_eb_bhs[0];
1347 
1348         status = 0;
1349 bail:
1350         if (new_eb_bhs) {
1351                 for (i = 0; i < new_blocks; i++)
1352                         brelse(new_eb_bhs[i]);
1353                 kfree(new_eb_bhs);
1354         }
1355 
1356         return status;
1357 }
1358 
1359 /*
1360  * adds another level to the allocation tree.
1361  * returns back the new extent block so you can add a branch to it
1362  * after this call.
1363  */
1364 static int ocfs2_shift_tree_depth(handle_t *handle,
1365                                   struct ocfs2_extent_tree *et,
1366                                   struct ocfs2_alloc_context *meta_ac,
1367                                   struct buffer_head **ret_new_eb_bh)
1368 {
1369         int status, i, block_given = 0;
1370         u32 new_clusters;
1371         struct buffer_head *new_eb_bh = NULL;
1372         struct ocfs2_extent_block *eb;
1373         struct ocfs2_extent_list  *root_el;
1374         struct ocfs2_extent_list  *eb_el;
1375 
1376         if (!ocfs2_is_dealloc_empty(et)) {
1377                 status = ocfs2_reuse_blk_from_dealloc(handle, et,
1378                                                       &new_eb_bh, 1,
1379                                                       &block_given);
1380         } else if (meta_ac) {
1381                 status = ocfs2_create_new_meta_bhs(handle, et, 1, meta_ac,
1382                                                    &new_eb_bh);
1383 
1384         } else {
1385                 BUG();
1386         }
1387 
1388         if (status < 0) {
1389                 mlog_errno(status);
1390                 goto bail;
1391         }
1392 
1393         eb = (struct ocfs2_extent_block *) new_eb_bh->b_data;
1394         /* ocfs2_create_new_meta_bhs() should create it right! */
1395         BUG_ON(!OCFS2_IS_VALID_EXTENT_BLOCK(eb));
1396 
1397         eb_el = &eb->h_list;
1398         root_el = et->et_root_el;
1399 
1400         status = ocfs2_journal_access_eb(handle, et->et_ci, new_eb_bh,
1401                                          OCFS2_JOURNAL_ACCESS_CREATE);
1402         if (status < 0) {
1403                 mlog_errno(status);
1404                 goto bail;
1405         }
1406 
1407         /* copy the root extent list data into the new extent block */
1408         eb_el->l_tree_depth = root_el->l_tree_depth;
1409         eb_el->l_next_free_rec = root_el->l_next_free_rec;
1410         for (i = 0; i < le16_to_cpu(root_el->l_next_free_rec); i++)
1411                 eb_el->l_recs[i] = root_el->l_recs[i];
1412 
1413         ocfs2_journal_dirty(handle, new_eb_bh);
1414 
1415         status = ocfs2_et_root_journal_access(handle, et,
1416                                               OCFS2_JOURNAL_ACCESS_WRITE);
1417         if (status < 0) {
1418                 mlog_errno(status);
1419                 goto bail;
1420         }
1421 
1422         new_clusters = ocfs2_sum_rightmost_rec(eb_el);
1423 
1424         /* update root_bh now */
1425         le16_add_cpu(&root_el->l_tree_depth, 1);
1426         root_el->l_recs[0].e_cpos = 0;
1427         root_el->l_recs[0].e_blkno = eb->h_blkno;
1428         root_el->l_recs[0].e_int_clusters = cpu_to_le32(new_clusters);
1429         for (i = 1; i < le16_to_cpu(root_el->l_next_free_rec); i++)
1430                 memset(&root_el->l_recs[i], 0, sizeof(struct ocfs2_extent_rec));
1431         root_el->l_next_free_rec = cpu_to_le16(1);
1432 
1433         /* If this is our 1st tree depth shift, then last_eb_blk
1434          * becomes the allocated extent block */
1435         if (root_el->l_tree_depth == cpu_to_le16(1))
1436                 ocfs2_et_set_last_eb_blk(et, le64_to_cpu(eb->h_blkno));
1437 
1438         ocfs2_journal_dirty(handle, et->et_root_bh);
1439 
1440         *ret_new_eb_bh = new_eb_bh;
1441         new_eb_bh = NULL;
1442         status = 0;
1443 bail:
1444         brelse(new_eb_bh);
1445 
1446         return status;
1447 }
1448 
1449 /*
1450  * Should only be called when there is no space left in any of the
1451  * leaf nodes. What we want to do is find the lowest tree depth
1452  * non-leaf extent block with room for new records. There are three
1453  * valid results of this search:
1454  *
1455  * 1) a lowest extent block is found, then we pass it back in
1456  *    *lowest_eb_bh and return ''
1457  *
1458  * 2) the search fails to find anything, but the root_el has room. We
1459  *    pass NULL back in *lowest_eb_bh, but still return ''
1460  *
1461  * 3) the search fails to find anything AND the root_el is full, in
1462  *    which case we return > 0
1463  *
1464  * return status < 0 indicates an error.
1465  */
1466 static int ocfs2_find_branch_target(struct ocfs2_extent_tree *et,
1467                                     struct buffer_head **target_bh)
1468 {
1469         int status = 0, i;
1470         u64 blkno;
1471         struct ocfs2_extent_block *eb;
1472         struct ocfs2_extent_list  *el;
1473         struct buffer_head *bh = NULL;
1474         struct buffer_head *lowest_bh = NULL;
1475 
1476         *target_bh = NULL;
1477 
1478         el = et->et_root_el;
1479 
1480         while(le16_to_cpu(el->l_tree_depth) > 1) {
1481                 if (le16_to_cpu(el->l_next_free_rec) == 0) {
1482                         status = ocfs2_error(ocfs2_metadata_cache_get_super(et->et_ci),
1483                                         "Owner %llu has empty extent list (next_free_rec == 0)\n",
1484                                         (unsigned long long)ocfs2_metadata_cache_owner(et->et_ci));
1485                         goto bail;
1486                 }
1487                 i = le16_to_cpu(el->l_next_free_rec) - 1;
1488                 blkno = le64_to_cpu(el->l_recs[i].e_blkno);
1489                 if (!blkno) {
1490                         status = ocfs2_error(ocfs2_metadata_cache_get_super(et->et_ci),
1491                                         "Owner %llu has extent list where extent # %d has no physical block start\n",
1492                                         (unsigned long long)ocfs2_metadata_cache_owner(et->et_ci), i);
1493                         goto bail;
1494                 }
1495 
1496                 brelse(bh);
1497                 bh = NULL;
1498 
1499                 status = ocfs2_read_extent_block(et->et_ci, blkno, &bh);
1500                 if (status < 0) {
1501                         mlog_errno(status);
1502                         goto bail;
1503                 }
1504 
1505                 eb = (struct ocfs2_extent_block *) bh->b_data;
1506                 el = &eb->h_list;
1507 
1508                 if (le16_to_cpu(el->l_next_free_rec) <
1509                     le16_to_cpu(el->l_count)) {
1510                         brelse(lowest_bh);
1511                         lowest_bh = bh;
1512                         get_bh(lowest_bh);
1513                 }
1514         }
1515 
1516         /* If we didn't find one and the fe doesn't have any room,
1517          * then return '1' */
1518         el = et->et_root_el;
1519         if (!lowest_bh && (el->l_next_free_rec == el->l_count))
1520                 status = 1;
1521 
1522         *target_bh = lowest_bh;
1523 bail:
1524         brelse(bh);
1525 
1526         return status;
1527 }
1528 
1529 /*
1530  * Grow a b-tree so that it has more records.
1531  *
1532  * We might shift the tree depth in which case existing paths should
1533  * be considered invalid.
1534  *
1535  * Tree depth after the grow is returned via *final_depth.
1536  *
1537  * *last_eb_bh will be updated by ocfs2_add_branch().
1538  */
1539 static int ocfs2_grow_tree(handle_t *handle, struct ocfs2_extent_tree *et,
1540                            int *final_depth, struct buffer_head **last_eb_bh,
1541                            struct ocfs2_alloc_context *meta_ac)
1542 {
1543         int ret, shift;
1544         struct ocfs2_extent_list *el = et->et_root_el;
1545         int depth = le16_to_cpu(el->l_tree_depth);
1546         struct buffer_head *bh = NULL;
1547 
1548         BUG_ON(meta_ac == NULL && ocfs2_is_dealloc_empty(et));
1549 
1550         shift = ocfs2_find_branch_target(et, &bh);
1551         if (shift < 0) {
1552                 ret = shift;
1553                 mlog_errno(ret);
1554                 goto out;
1555         }
1556 
1557         /* We traveled all the way to the bottom of the allocation tree
1558          * and didn't find room for any more extents - we need to add
1559          * another tree level */
1560         if (shift) {
1561                 BUG_ON(bh);
1562                 trace_ocfs2_grow_tree(
1563                         (unsigned long long)
1564                         ocfs2_metadata_cache_owner(et->et_ci),
1565                         depth);
1566 
1567                 /* ocfs2_shift_tree_depth will return us a buffer with
1568                  * the new extent block (so we can pass that to
1569                  * ocfs2_add_branch). */
1570                 ret = ocfs2_shift_tree_depth(handle, et, meta_ac, &bh);
1571                 if (ret < 0) {
1572                         mlog_errno(ret);
1573                         goto out;
1574                 }
1575                 depth++;
1576                 if (depth == 1) {
1577                         /*
1578                          * Special case: we have room now if we shifted from
1579                          * tree_depth 0, so no more work needs to be done.
1580                          *
1581                          * We won't be calling add_branch, so pass
1582                          * back *last_eb_bh as the new leaf. At depth
1583                          * zero, it should always be null so there's
1584                          * no reason to brelse.
1585                          */
1586                         BUG_ON(*last_eb_bh);
1587                         get_bh(bh);
1588                         *last_eb_bh = bh;
1589                         goto out;
1590                 }
1591         }
1592 
1593         /* call ocfs2_add_branch to add the final part of the tree with
1594          * the new data. */
1595         ret = ocfs2_add_branch(handle, et, bh, last_eb_bh,
1596                                meta_ac);
1597         if (ret < 0)
1598                 mlog_errno(ret);
1599 
1600 out:
1601         if (final_depth)
1602                 *final_depth = depth;
1603         brelse(bh);
1604         return ret;
1605 }
1606 
1607 /*
1608  * This function will discard the rightmost extent record.
1609  */
1610 static void ocfs2_shift_records_right(struct ocfs2_extent_list *el)
1611 {
1612         int next_free = le16_to_cpu(el->l_next_free_rec);
1613         int count = le16_to_cpu(el->l_count);
1614         unsigned int num_bytes;
1615 
1616         BUG_ON(!next_free);
1617         /* This will cause us to go off the end of our extent list. */
1618         BUG_ON(next_free >= count);
1619 
1620         num_bytes = sizeof(struct ocfs2_extent_rec) * next_free;
1621 
1622         memmove(&el->l_recs[1], &el->l_recs[0], num_bytes);
1623 }
1624 
1625 static void ocfs2_rotate_leaf(struct ocfs2_extent_list *el,
1626                               struct ocfs2_extent_rec *insert_rec)
1627 {
1628         int i, insert_index, next_free, has_empty, num_bytes;
1629         u32 insert_cpos = le32_to_cpu(insert_rec->e_cpos);
1630         struct ocfs2_extent_rec *rec;
1631 
1632         next_free = le16_to_cpu(el->l_next_free_rec);
1633         has_empty = ocfs2_is_empty_extent(&el->l_recs[0]);
1634 
1635         BUG_ON(!next_free);
1636 
1637         /* The tree code before us didn't allow enough room in the leaf. */
1638         BUG_ON(el->l_next_free_rec == el->l_count && !has_empty);
1639 
1640         /*
1641          * The easiest way to approach this is to just remove the
1642          * empty extent and temporarily decrement next_free.
1643          */
1644         if (has_empty) {
1645                 /*
1646                  * If next_free was 1 (only an empty extent), this
1647                  * loop won't execute, which is fine. We still want
1648                  * the decrement above to happen.
1649                  */
1650                 for(i = 0; i < (next_free - 1); i++)
1651                         el->l_recs[i] = el->l_recs[i+1];
1652 
1653                 next_free--;
1654         }
1655 
1656         /*
1657          * Figure out what the new record index should be.
1658          */
1659         for(i = 0; i < next_free; i++) {
1660                 rec = &el->l_recs[i];
1661 
1662                 if (insert_cpos < le32_to_cpu(rec->e_cpos))
1663                         break;
1664         }
1665         insert_index = i;
1666 
1667         trace_ocfs2_rotate_leaf(insert_cpos, insert_index,
1668                                 has_empty, next_free,
1669                                 le16_to_cpu(el->l_count));
1670 
1671         BUG_ON(insert_index < 0);
1672         BUG_ON(insert_index >= le16_to_cpu(el->l_count));
1673         BUG_ON(insert_index > next_free);
1674 
1675         /*
1676          * No need to memmove if we're just adding to the tail.
1677          */
1678         if (insert_index != next_free) {
1679                 BUG_ON(next_free >= le16_to_cpu(el->l_count));
1680 
1681                 num_bytes = next_free - insert_index;
1682                 num_bytes *= sizeof(struct ocfs2_extent_rec);
1683                 memmove(&el->l_recs[insert_index + 1],
1684                         &el->l_recs[insert_index],
1685                         num_bytes);
1686         }
1687 
1688         /*
1689          * Either we had an empty extent, and need to re-increment or
1690          * there was no empty extent on a non full rightmost leaf node,
1691          * in which case we still need to increment.
1692          */
1693         next_free++;
1694         el->l_next_free_rec = cpu_to_le16(next_free);
1695         /*
1696          * Make sure none of the math above just messed up our tree.
1697          */
1698         BUG_ON(le16_to_cpu(el->l_next_free_rec) > le16_to_cpu(el->l_count));
1699 
1700         el->l_recs[insert_index] = *insert_rec;
1701 
1702 }
1703 
1704 static void ocfs2_remove_empty_extent(struct ocfs2_extent_list *el)
1705 {
1706         int size, num_recs = le16_to_cpu(el->l_next_free_rec);
1707 
1708         BUG_ON(num_recs == 0);
1709 
1710         if (ocfs2_is_empty_extent(&el->l_recs[0])) {
1711                 num_recs--;
1712                 size = num_recs * sizeof(struct ocfs2_extent_rec);
1713                 memmove(&el->l_recs[0], &el->l_recs[1], size);
1714                 memset(&el->l_recs[num_recs], 0,
1715                        sizeof(struct ocfs2_extent_rec));
1716                 el->l_next_free_rec = cpu_to_le16(num_recs);
1717         }
1718 }
1719 
1720 /*
1721  * Create an empty extent record .
1722  *
1723  * l_next_free_rec may be updated.
1724  *
1725  * If an empty extent already exists do nothing.
1726  */
1727 static void ocfs2_create_empty_extent(struct ocfs2_extent_list *el)
1728 {
1729         int next_free = le16_to_cpu(el->l_next_free_rec);
1730 
1731         BUG_ON(le16_to_cpu(el->l_tree_depth) != 0);
1732 
1733         if (next_free == 0)
1734                 goto set_and_inc;
1735 
1736         if (ocfs2_is_empty_extent(&el->l_recs[0]))
1737                 return;
1738 
1739         mlog_bug_on_msg(el->l_count == el->l_next_free_rec,
1740                         "Asked to create an empty extent in a full list:\n"
1741                         "count = %u, tree depth = %u",
1742                         le16_to_cpu(el->l_count),
1743                         le16_to_cpu(el->l_tree_depth));
1744 
1745         ocfs2_shift_records_right(el);
1746 
1747 set_and_inc:
1748         le16_add_cpu(&el->l_next_free_rec, 1);
1749         memset(&el->l_recs[0], 0, sizeof(struct ocfs2_extent_rec));
1750 }
1751 
1752 /*
1753  * For a rotation which involves two leaf nodes, the "root node" is
1754  * the lowest level tree node which contains a path to both leafs. This
1755  * resulting set of information can be used to form a complete "subtree"
1756  *
1757  * This function is passed two full paths from the dinode down to a
1758  * pair of adjacent leaves. It's task is to figure out which path
1759  * index contains the subtree root - this can be the root index itself
1760  * in a worst-case rotation.
1761  *
1762  * The array index of the subtree root is passed back.
1763  */
1764 int ocfs2_find_subtree_root(struct ocfs2_extent_tree *et,
1765                             struct ocfs2_path *left,
1766                             struct ocfs2_path *right)
1767 {
1768         int i = 0;
1769 
1770         /*
1771          * Check that the caller passed in two paths from the same tree.
1772          */
1773         BUG_ON(path_root_bh(left) != path_root_bh(right));
1774 
1775         do {
1776                 i++;
1777 
1778                 /*
1779                  * The caller didn't pass two adjacent paths.
1780                  */
1781                 mlog_bug_on_msg(i > left->p_tree_depth,
1782                                 "Owner %llu, left depth %u, right depth %u\n"
1783                                 "left leaf blk %llu, right leaf blk %llu\n",
1784                                 (unsigned long long)ocfs2_metadata_cache_owner(et->et_ci),
1785                                 left->p_tree_depth, right->p_tree_depth,
1786                                 (unsigned long long)path_leaf_bh(left)->b_blocknr,
1787                                 (unsigned long long)path_leaf_bh(right)->b_blocknr);
1788         } while (left->p_node[i].bh->b_blocknr ==
1789                  right->p_node[i].bh->b_blocknr);
1790 
1791         return i - 1;
1792 }
1793 
1794 typedef void (path_insert_t)(void *, struct buffer_head *);
1795 
1796 /*
1797  * Traverse a btree path in search of cpos, starting at root_el.
1798  *
1799  * This code can be called with a cpos larger than the tree, in which
1800  * case it will return the rightmost path.
1801  */
1802 static int __ocfs2_find_path(struct ocfs2_caching_info *ci,
1803                              struct ocfs2_extent_list *root_el, u32 cpos,
1804                              path_insert_t *func, void *data)
1805 {
1806         int i, ret = 0;
1807         u32 range;
1808         u64 blkno;
1809         struct buffer_head *bh = NULL;
1810         struct ocfs2_extent_block *eb;
1811         struct ocfs2_extent_list *el;
1812         struct ocfs2_extent_rec *rec;
1813 
1814         el = root_el;
1815         while (el->l_tree_depth) {
1816                 if (le16_to_cpu(el->l_next_free_rec) == 0) {
1817                         ocfs2_error(ocfs2_metadata_cache_get_super(ci),
1818                                     "Owner %llu has empty extent list at depth %u\n",
1819                                     (unsigned long long)ocfs2_metadata_cache_owner(ci),
1820                                     le16_to_cpu(el->l_tree_depth));
1821                         ret = -EROFS;
1822                         goto out;
1823 
1824                 }
1825 
1826                 for(i = 0; i < le16_to_cpu(el->l_next_free_rec) - 1; i++) {
1827                         rec = &el->l_recs[i];
1828 
1829                         /*
1830                          * In the case that cpos is off the allocation
1831                          * tree, this should just wind up returning the
1832                          * rightmost record.
1833                          */
1834                         range = le32_to_cpu(rec->e_cpos) +
1835                                 ocfs2_rec_clusters(el, rec);
1836                         if (cpos >= le32_to_cpu(rec->e_cpos) && cpos < range)
1837                             break;
1838                 }
1839 
1840                 blkno = le64_to_cpu(el->l_recs[i].e_blkno);
1841                 if (blkno == 0) {
1842                         ocfs2_error(ocfs2_metadata_cache_get_super(ci),
1843                                     "Owner %llu has bad blkno in extent list at depth %u (index %d)\n",
1844                                     (unsigned long long)ocfs2_metadata_cache_owner(ci),
1845                                     le16_to_cpu(el->l_tree_depth), i);
1846                         ret = -EROFS;
1847                         goto out;
1848                 }
1849 
1850                 brelse(bh);
1851                 bh = NULL;
1852                 ret = ocfs2_read_extent_block(ci, blkno, &bh);
1853                 if (ret) {
1854                         mlog_errno(ret);
1855                         goto out;
1856                 }
1857 
1858                 eb = (struct ocfs2_extent_block *) bh->b_data;
1859                 el = &eb->h_list;
1860 
1861                 if (le16_to_cpu(el->l_next_free_rec) >
1862                     le16_to_cpu(el->l_count)) {
1863                         ocfs2_error(ocfs2_metadata_cache_get_super(ci),
1864                                     "Owner %llu has bad count in extent list at block %llu (next free=%u, count=%u)\n",
1865                                     (unsigned long long)ocfs2_metadata_cache_owner(ci),
1866                                     (unsigned long long)bh->b_blocknr,
1867                                     le16_to_cpu(el->l_next_free_rec),
1868                                     le16_to_cpu(el->l_count));
1869                         ret = -EROFS;
1870                         goto out;
1871                 }
1872 
1873                 if (func)
1874                         func(data, bh);
1875         }
1876 
1877 out:
1878         /*
1879          * Catch any trailing bh that the loop didn't handle.
1880          */
1881         brelse(bh);
1882 
1883         return ret;
1884 }
1885 
1886 /*
1887  * Given an initialized path (that is, it has a valid root extent
1888  * list), this function will traverse the btree in search of the path
1889  * which would contain cpos.
1890  *
1891  * The path traveled is recorded in the path structure.
1892  *
1893  * Note that this will not do any comparisons on leaf node extent
1894  * records, so it will work fine in the case that we just added a tree
1895  * branch.
1896  */
1897 struct find_path_data {
1898         int index;
1899         struct ocfs2_path *path;
1900 };
1901 static void find_path_ins(void *data, struct buffer_head *bh)
1902 {
1903         struct find_path_data *fp = data;
1904 
1905         get_bh(bh);
1906         ocfs2_path_insert_eb(fp->path, fp->index, bh);
1907         fp->index++;
1908 }
1909 int ocfs2_find_path(struct ocfs2_caching_info *ci,
1910                     struct ocfs2_path *path, u32 cpos)
1911 {
1912         struct find_path_data data;
1913 
1914         data.index = 1;
1915         data.path = path;
1916         return __ocfs2_find_path(ci, path_root_el(path), cpos,
1917                                  find_path_ins, &data);
1918 }
1919 
1920 static void find_leaf_ins(void *data, struct buffer_head *bh)
1921 {
1922         struct ocfs2_extent_block *eb =(struct ocfs2_extent_block *)bh->b_data;
1923         struct ocfs2_extent_list *el = &eb->h_list;
1924         struct buffer_head **ret = data;
1925 
1926         /* We want to retain only the leaf block. */
1927         if (le16_to_cpu(el->l_tree_depth) == 0) {
1928                 get_bh(bh);
1929                 *ret = bh;
1930         }
1931 }
1932 /*
1933  * Find the leaf block in the tree which would contain cpos. No
1934  * checking of the actual leaf is done.
1935  *
1936  * Some paths want to call this instead of allocating a path structure
1937  * and calling ocfs2_find_path().
1938  *
1939  * This function doesn't handle non btree extent lists.
1940  */
1941 int ocfs2_find_leaf(struct ocfs2_caching_info *ci,
1942                     struct ocfs2_extent_list *root_el, u32 cpos,
1943                     struct buffer_head **leaf_bh)
1944 {
1945         int ret;
1946         struct buffer_head *bh = NULL;
1947 
1948         ret = __ocfs2_find_path(ci, root_el, cpos, find_leaf_ins, &bh);
1949         if (ret) {
1950                 mlog_errno(ret);
1951                 goto out;
1952         }
1953 
1954         *leaf_bh = bh;
1955 out:
1956         return ret;
1957 }
1958 
1959 /*
1960  * Adjust the adjacent records (left_rec, right_rec) involved in a rotation.
1961  *
1962  * Basically, we've moved stuff around at the bottom of the tree and
1963  * we need to fix up the extent records above the changes to reflect
1964  * the new changes.
1965  *
1966  * left_rec: the record on the left.
1967  * right_rec: the record to the right of left_rec
1968  * right_child_el: is the child list pointed to by right_rec
1969  *
1970  * By definition, this only works on interior nodes.
1971  */
1972 static void ocfs2_adjust_adjacent_records(struct ocfs2_extent_rec *left_rec,
1973                                   struct ocfs2_extent_rec *right_rec,
1974                                   struct ocfs2_extent_list *right_child_el)
1975 {
1976         u32 left_clusters, right_end;
1977 
1978         /*
1979          * Interior nodes never have holes. Their cpos is the cpos of
1980          * the leftmost record in their child list. Their cluster
1981          * count covers the full theoretical range of their child list
1982          * - the range between their cpos and the cpos of the record
1983          * immediately to their right.
1984          */
1985         left_clusters = le32_to_cpu(right_child_el->l_recs[0].e_cpos);
1986         if (!ocfs2_rec_clusters(right_child_el, &right_child_el->l_recs[0])) {
1987                 BUG_ON(right_child_el->l_tree_depth);
1988                 BUG_ON(le16_to_cpu(right_child_el->l_next_free_rec) <= 1);
1989                 left_clusters = le32_to_cpu(right_child_el->l_recs[1].e_cpos);
1990         }
1991         left_clusters -= le32_to_cpu(left_rec->e_cpos);
1992         left_rec->e_int_clusters = cpu_to_le32(left_clusters);
1993 
1994         /*
1995          * Calculate the rightmost cluster count boundary before
1996          * moving cpos - we will need to adjust clusters after
1997          * updating e_cpos to keep the same highest cluster count.
1998          */
1999         right_end = le32_to_cpu(right_rec->e_cpos);
2000         right_end += le32_to_cpu(right_rec->e_int_clusters);
2001 
2002         right_rec->e_cpos = left_rec->e_cpos;
2003         le32_add_cpu(&right_rec->e_cpos, left_clusters);
2004 
2005         right_end -= le32_to_cpu(right_rec->e_cpos);
2006         right_rec->e_int_clusters = cpu_to_le32(right_end);
2007 }
2008 
2009 /*
2010  * Adjust the adjacent root node records involved in a
2011  * rotation. left_el_blkno is passed in as a key so that we can easily
2012  * find it's index in the root list.
2013  */
2014 static void ocfs2_adjust_root_records(struct ocfs2_extent_list *root_el,
2015                                       struct ocfs2_extent_list *left_el,
2016                                       struct ocfs2_extent_list *right_el,
2017                                       u64 left_el_blkno)
2018 {
2019         int i;
2020 
2021         BUG_ON(le16_to_cpu(root_el->l_tree_depth) <=
2022                le16_to_cpu(left_el->l_tree_depth));
2023 
2024         for(i = 0; i < le16_to_cpu(root_el->l_next_free_rec) - 1; i++) {
2025                 if (le64_to_cpu(root_el->l_recs[i].e_blkno) == left_el_blkno)
2026                         break;
2027         }
2028 
2029         /*
2030          * The path walking code should have never returned a root and
2031          * two paths which are not adjacent.
2032          */
2033         BUG_ON(i >= (le16_to_cpu(root_el->l_next_free_rec) - 1));
2034 
2035         ocfs2_adjust_adjacent_records(&root_el->l_recs[i],
2036                                       &root_el->l_recs[i + 1], right_el);
2037 }
2038 
2039 /*
2040  * We've changed a leaf block (in right_path) and need to reflect that
2041  * change back up the subtree.
2042  *
2043  * This happens in multiple places:
2044  *   - When we've moved an extent record from the left path leaf to the right
2045  *     path leaf to make room for an empty extent in the left path leaf.
2046  *   - When our insert into the right path leaf is at the leftmost edge
2047  *     and requires an update of the path immediately to it's left. This
2048  *     can occur at the end of some types of rotation and appending inserts.
2049  *   - When we've adjusted the last extent record in the left path leaf and the
2050  *     1st extent record in the right path leaf during cross extent block merge.
2051  */
2052 static void ocfs2_complete_edge_insert(handle_t *handle,
2053                                        struct ocfs2_path *left_path,
2054                                        struct ocfs2_path *right_path,
2055                                        int subtree_index)
2056 {
2057         int i, idx;
2058         struct ocfs2_extent_list *el, *left_el, *right_el;
2059         struct ocfs2_extent_rec *left_rec, *right_rec;
2060         struct buffer_head *root_bh = left_path->p_node[subtree_index].bh;
2061 
2062         /*
2063          * Update the counts and position values within all the
2064          * interior nodes to reflect the leaf rotation we just did.
2065          *
2066          * The root node is handled below the loop.
2067          *
2068          * We begin the loop with right_el and left_el pointing to the
2069          * leaf lists and work our way up.
2070          *
2071          * NOTE: within this loop, left_el and right_el always refer
2072          * to the *child* lists.
2073          */
2074         left_el = path_leaf_el(left_path);
2075         right_el = path_leaf_el(right_path);
2076         for(i = left_path->p_tree_depth - 1; i > subtree_index; i--) {
2077                 trace_ocfs2_complete_edge_insert(i);
2078 
2079                 /*
2080                  * One nice property of knowing that all of these
2081                  * nodes are below the root is that we only deal with
2082                  * the leftmost right node record and the rightmost
2083                  * left node record.
2084                  */
2085                 el = left_path->p_node[i].el;
2086                 idx = le16_to_cpu(left_el->l_next_free_rec) - 1;
2087                 left_rec = &el->l_recs[idx];
2088 
2089                 el = right_path->p_node[i].el;
2090                 right_rec = &el->l_recs[0];
2091 
2092                 ocfs2_adjust_adjacent_records(left_rec, right_rec, right_el);
2093 
2094                 ocfs2_journal_dirty(handle, left_path->p_node[i].bh);
2095                 ocfs2_journal_dirty(handle, right_path->p_node[i].bh);
2096 
2097                 /*
2098                  * Setup our list pointers now so that the current
2099                  * parents become children in the next iteration.
2100                  */
2101                 left_el = left_path->p_node[i].el;
2102                 right_el = right_path->p_node[i].el;
2103         }
2104 
2105         /*
2106          * At the root node, adjust the two adjacent records which
2107          * begin our path to the leaves.
2108          */
2109 
2110         el = left_path->p_node[subtree_index].el;
2111         left_el = left_path->p_node[subtree_index + 1].el;
2112         right_el = right_path->p_node[subtree_index + 1].el;
2113 
2114         ocfs2_adjust_root_records(el, left_el, right_el,
2115                                   left_path->p_node[subtree_index + 1].bh->b_blocknr);
2116 
2117         root_bh = left_path->p_node[subtree_index].bh;
2118 
2119         ocfs2_journal_dirty(handle, root_bh);
2120 }
2121 
2122 static int ocfs2_rotate_subtree_right(handle_t *handle,
2123                                       struct ocfs2_extent_tree *et,
2124                                       struct ocfs2_path *left_path,
2125                                       struct ocfs2_path *right_path,
2126                                       int subtree_index)
2127 {
2128         int ret, i;
2129         struct buffer_head *right_leaf_bh;
2130         struct buffer_head *left_leaf_bh = NULL;
2131         struct buffer_head *root_bh;
2132         struct ocfs2_extent_list *right_el, *left_el;
2133         struct ocfs2_extent_rec move_rec;
2134 
2135         left_leaf_bh = path_leaf_bh(left_path);
2136         left_el = path_leaf_el(left_path);
2137 
2138         if (left_el->l_next_free_rec != left_el->l_count) {
2139                 ocfs2_error(ocfs2_metadata_cache_get_super(et->et_ci),
2140                             "Inode %llu has non-full interior leaf node %llu (next free = %u)\n",
2141                             (unsigned long long)ocfs2_metadata_cache_owner(et->et_ci),
2142                             (unsigned long long)left_leaf_bh->b_blocknr,
2143                             le16_to_cpu(left_el->l_next_free_rec));
2144                 return -EROFS;
2145         }
2146 
2147         /*
2148          * This extent block may already have an empty record, so we
2149          * return early if so.
2150          */
2151         if (ocfs2_is_empty_extent(&left_el->l_recs[0]))
2152                 return 0;
2153 
2154         root_bh = left_path->p_node[subtree_index].bh;
2155         BUG_ON(root_bh != right_path->p_node[subtree_index].bh);
2156 
2157         ret = ocfs2_path_bh_journal_access(handle, et->et_ci, right_path,
2158                                            subtree_index);
2159         if (ret) {
2160                 mlog_errno(ret);
2161                 goto out;
2162         }
2163 
2164         for(i = subtree_index + 1; i < path_num_items(right_path); i++) {
2165                 ret = ocfs2_path_bh_journal_access(handle, et->et_ci,
2166                                                    right_path, i);
2167                 if (ret) {
2168                         mlog_errno(ret);
2169                         goto out;
2170                 }
2171 
2172                 ret = ocfs2_path_bh_journal_access(handle, et->et_ci,
2173                                                    left_path, i);
2174                 if (ret) {
2175                         mlog_errno(ret);
2176                         goto out;
2177                 }
2178         }
2179 
2180         right_leaf_bh = path_leaf_bh(right_path);
2181         right_el = path_leaf_el(right_path);
2182 
2183         /* This is a code error, not a disk corruption. */
2184         mlog_bug_on_msg(!right_el->l_next_free_rec, "Inode %llu: Rotate fails "
2185                         "because rightmost leaf block %llu is empty\n",
2186                         (unsigned long long)ocfs2_metadata_cache_owner(et->et_ci),
2187                         (unsigned long long)right_leaf_bh->b_blocknr);
2188 
2189         ocfs2_create_empty_extent(right_el);
2190 
2191         ocfs2_journal_dirty(handle, right_leaf_bh);
2192 
2193         /* Do the copy now. */
2194         i = le16_to_cpu(left_el->l_next_free_rec) - 1;
2195         move_rec = left_el->l_recs[i];
2196         right_el->l_recs[0] = move_rec;
2197 
2198         /*
2199          * Clear out the record we just copied and shift everything
2200          * over, leaving an empty extent in the left leaf.
2201          *
2202          * We temporarily subtract from next_free_rec so that the
2203          * shift will lose the tail record (which is now defunct).
2204          */
2205         le16_add_cpu(&left_el->l_next_free_rec, -1);
2206         ocfs2_shift_records_right(left_el);
2207         memset(&left_el->l_recs[0], 0, sizeof(struct ocfs2_extent_rec));
2208         le16_add_cpu(&left_el->l_next_free_rec, 1);
2209 
2210         ocfs2_journal_dirty(handle, left_leaf_bh);
2211 
2212         ocfs2_complete_edge_insert(handle, left_path, right_path,
2213                                    subtree_index);
2214 
2215 out:
2216         return ret;
2217 }
2218 
2219 /*
2220  * Given a full path, determine what cpos value would return us a path
2221  * containing the leaf immediately to the left of the current one.
2222  *
2223  * Will return zero if the path passed in is already the leftmost path.
2224  */
2225 int ocfs2_find_cpos_for_left_leaf(struct super_block *sb,
2226                                   struct ocfs2_path *path, u32 *cpos)
2227 {
2228         int i, j, ret = 0;
2229         u64 blkno;
2230         struct ocfs2_extent_list *el;
2231 
2232         BUG_ON(path->p_tree_depth == 0);
2233 
2234         *cpos = 0;
2235 
2236         blkno = path_leaf_bh(path)->b_blocknr;
2237 
2238         /* Start at the tree node just above the leaf and work our way up. */
2239         i = path->p_tree_depth - 1;
2240         while (i >= 0) {
2241                 el = path->p_node[i].el;
2242 
2243                 /*
2244                  * Find the extent record just before the one in our
2245                  * path.
2246                  */
2247                 for(j = 0; j < le16_to_cpu(el->l_next_free_rec); j++) {
2248                         if (le64_to_cpu(el->l_recs[j].e_blkno) == blkno) {
2249                                 if (j == 0) {
2250                                         if (i == 0) {
2251                                                 /*
2252                                                  * We've determined that the
2253                                                  * path specified is already
2254                                                  * the leftmost one - return a
2255                                                  * cpos of zero.
2256                                                  */
2257                                                 goto out;
2258                                         }
2259                                         /*
2260                                          * The leftmost record points to our
2261                                          * leaf - we need to travel up the
2262                                          * tree one level.
2263                                          */
2264                                         goto next_node;
2265                                 }
2266 
2267                                 *cpos = le32_to_cpu(el->l_recs[j - 1].e_cpos);
2268                                 *cpos = *cpos + ocfs2_rec_clusters(el,
2269                                                            &el->l_recs[j - 1]);
2270                                 *cpos = *cpos - 1;
2271                                 goto out;
2272                         }
2273                 }
2274 
2275                 /*
2276                  * If we got here, we never found a valid node where
2277                  * the tree indicated one should be.
2278                  */
2279                 ocfs2_error(sb, "Invalid extent tree at extent block %llu\n",
2280                             (unsigned long long)blkno);
2281                 ret = -EROFS;
2282                 goto out;
2283 
2284 next_node:
2285                 blkno = path->p_node[i].bh->b_blocknr;
2286                 i--;
2287         }
2288 
2289 out:
2290         return ret;
2291 }
2292 
2293 /*
2294  * Extend the transaction by enough credits to complete the rotation,
2295  * and still leave at least the original number of credits allocated
2296  * to this transaction.
2297  */
2298 static int ocfs2_extend_rotate_transaction(handle_t *handle, int subtree_depth,
2299                                            int op_credits,
2300                                            struct ocfs2_path *path)
2301 {
2302         int ret = 0;
2303         int credits = (path->p_tree_depth - subtree_depth) * 2 + 1 + op_credits;
2304 
2305         if (handle->h_buffer_credits < credits)
2306                 ret = ocfs2_extend_trans(handle,
2307                                          credits - handle->h_buffer_credits);
2308 
2309         return ret;
2310 }
2311 
2312 /*
2313  * Trap the case where we're inserting into the theoretical range past
2314  * the _actual_ left leaf range. Otherwise, we'll rotate a record
2315  * whose cpos is less than ours into the right leaf.
2316  *
2317  * It's only necessary to look at the rightmost record of the left
2318  * leaf because the logic that calls us should ensure that the
2319  * theoretical ranges in the path components above the leaves are
2320  * correct.
2321  */
2322 static int ocfs2_rotate_requires_path_adjustment(struct ocfs2_path *left_path,
2323                                                  u32 insert_cpos)
2324 {
2325         struct ocfs2_extent_list *left_el;
2326         struct ocfs2_extent_rec *rec;
2327         int next_free;
2328 
2329         left_el = path_leaf_el(left_path);
2330         next_free = le16_to_cpu(left_el->l_next_free_rec);
2331         rec = &left_el->l_recs[next_free - 1];
2332 
2333         if (insert_cpos > le32_to_cpu(rec->e_cpos))
2334                 return 1;
2335         return 0;
2336 }
2337 
2338 static int ocfs2_leftmost_rec_contains(struct ocfs2_extent_list *el, u32 cpos)
2339 {
2340         int next_free = le16_to_cpu(el->l_next_free_rec);
2341         unsigned int range;
2342         struct ocfs2_extent_rec *rec;
2343 
2344         if (next_free == 0)
2345                 return 0;
2346 
2347         rec = &el->l_recs[0];
2348         if (ocfs2_is_empty_extent(rec)) {
2349                 /* Empty list. */
2350                 if (next_free == 1)
2351                         return 0;
2352                 rec = &el->l_recs[1];
2353         }
2354 
2355         range = le32_to_cpu(rec->e_cpos) + ocfs2_rec_clusters(el, rec);
2356         if (cpos >= le32_to_cpu(rec->e_cpos) && cpos < range)
2357                 return 1;
2358         return 0;
2359 }
2360 
2361 /*
2362  * Rotate all the records in a btree right one record, starting at insert_cpos.
2363  *
2364  * The path to the rightmost leaf should be passed in.
2365  *
2366  * The array is assumed to be large enough to hold an entire path (tree depth).
2367  *
2368  * Upon successful return from this function:
2369  *
2370  * - The 'right_path' array will contain a path to the leaf block
2371  *   whose range contains e_cpos.
2372  * - That leaf block will have a single empty extent in list index 0.
2373  * - In the case that the rotation requires a post-insert update,
2374  *   *ret_left_path will contain a valid path which can be passed to
2375  *   ocfs2_insert_path().
2376  */
2377 static int ocfs2_rotate_tree_right(handle_t *handle,
2378                                    struct ocfs2_extent_tree *et,
2379                                    enum ocfs2_split_type split,
2380                                    u32 insert_cpos,
2381                                    struct ocfs2_path *right_path,
2382                                    struct ocfs2_path **ret_left_path)
2383 {
2384         int ret, start, orig_credits = handle->h_buffer_credits;
2385         u32 cpos;
2386         struct ocfs2_path *left_path = NULL;
2387         struct super_block *sb = ocfs2_metadata_cache_get_super(et->et_ci);
2388 
2389         *ret_left_path = NULL;
2390 
2391         left_path = ocfs2_new_path_from_path(right_path);
2392         if (!left_path) {
2393                 ret = -ENOMEM;
2394                 mlog_errno(ret);
2395                 goto out;
2396         }
2397 
2398         ret = ocfs2_find_cpos_for_left_leaf(sb, right_path, &cpos);
2399         if (ret) {
2400                 mlog_errno(ret);
2401                 goto out;
2402         }
2403 
2404         trace_ocfs2_rotate_tree_right(
2405                 (unsigned long long)ocfs2_metadata_cache_owner(et->et_ci),
2406                 insert_cpos, cpos);
2407 
2408         /*
2409          * What we want to do here is:
2410          *
2411          * 1) Start with the rightmost path.
2412          *
2413          * 2) Determine a path to the leaf block directly to the left
2414          *    of that leaf.
2415          *
2416          * 3) Determine the 'subtree root' - the lowest level tree node
2417          *    which contains a path to both leaves.
2418          *
2419          * 4) Rotate the subtree.
2420          *
2421          * 5) Find the next subtree by considering the left path to be
2422          *    the new right path.
2423          *
2424          * The check at the top of this while loop also accepts
2425          * insert_cpos == cpos because cpos is only a _theoretical_
2426          * value to get us the left path - insert_cpos might very well
2427          * be filling that hole.
2428          *
2429          * Stop at a cpos of '' because we either started at the
2430          * leftmost branch (i.e., a tree with one branch and a
2431          * rotation inside of it), or we've gone as far as we can in
2432          * rotating subtrees.
2433          */
2434         while (cpos && insert_cpos <= cpos) {
2435                 trace_ocfs2_rotate_tree_right(
2436                         (unsigned long long)
2437                         ocfs2_metadata_cache_owner(et->et_ci),
2438                         insert_cpos, cpos);
2439 
2440                 ret = ocfs2_find_path(et->et_ci, left_path, cpos);
2441                 if (ret) {
2442                         mlog_errno(ret);
2443                         goto out;
2444                 }
2445 
2446                 mlog_bug_on_msg(path_leaf_bh(left_path) ==
2447                                 path_leaf_bh(right_path),
2448                                 "Owner %llu: error during insert of %u "
2449                                 "(left path cpos %u) results in two identical "
2450                                 "paths ending at %llu\n",
2451                                 (unsigned long long)ocfs2_metadata_cache_owner(et->et_ci),
2452                                 insert_cpos, cpos,
2453                                 (unsigned long long)
2454                                 path_leaf_bh(left_path)->b_blocknr);
2455 
2456                 if (split == SPLIT_NONE &&
2457                     ocfs2_rotate_requires_path_adjustment(left_path,
2458                                                           insert_cpos)) {
2459 
2460                         /*
2461                          * We've rotated the tree as much as we
2462                          * should. The rest is up to
2463                          * ocfs2_insert_path() to complete, after the
2464                          * record insertion. We indicate this
2465                          * situation by returning the left path.
2466                          *
2467                          * The reason we don't adjust the records here
2468                          * before the record insert is that an error
2469                          * later might break the rule where a parent
2470                          * record e_cpos will reflect the actual
2471                          * e_cpos of the 1st nonempty record of the
2472                          * child list.
2473                          */
2474                         *ret_left_path = left_path;
2475                         goto out_ret_path;
2476                 }
2477 
2478                 start = ocfs2_find_subtree_root(et, left_path, right_path);
2479 
2480                 trace_ocfs2_rotate_subtree(start,
2481                         (unsigned long long)
2482                         right_path->p_node[start].bh->b_blocknr,
2483                         right_path->p_tree_depth);
2484 
2485                 ret = ocfs2_extend_rotate_transaction(handle, start,
2486                                                       orig_credits, right_path);
2487                 if (ret) {
2488                         mlog_errno(ret);
2489                         goto out;
2490                 }
2491 
2492                 ret = ocfs2_rotate_subtree_right(handle, et, left_path,
2493                                                  right_path, start);
2494                 if (ret) {
2495                         mlog_errno(ret);
2496                         goto out;
2497                 }
2498 
2499                 if (split != SPLIT_NONE &&
2500                     ocfs2_leftmost_rec_contains(path_leaf_el(right_path),
2501                                                 insert_cpos)) {
2502                         /*
2503                          * A rotate moves the rightmost left leaf
2504                          * record over to the leftmost right leaf
2505                          * slot. If we're doing an extent split
2506                          * instead of a real insert, then we have to
2507                          * check that the extent to be split wasn't
2508                          * just moved over. If it was, then we can
2509                          * exit here, passing left_path back -
2510                          * ocfs2_split_extent() is smart enough to
2511                          * search both leaves.
2512                          */
2513                         *ret_left_path = left_path;
2514                         goto out_ret_path;
2515                 }
2516 
2517                 /*
2518                  * There is no need to re-read the next right path
2519                  * as we know that it'll be our current left
2520                  * path. Optimize by copying values instead.
2521                  */
2522                 ocfs2_mv_path(right_path, left_path);
2523 
2524                 ret = ocfs2_find_cpos_for_left_leaf(sb, right_path, &cpos);
2525                 if (ret) {
2526                         mlog_errno(ret);
2527                         goto out;
2528                 }
2529         }
2530 
2531 out:
2532         ocfs2_free_path(left_path);
2533 
2534 out_ret_path:
2535         return ret;
2536 }
2537 
2538 static int ocfs2_update_edge_lengths(handle_t *handle,
2539                                      struct ocfs2_extent_tree *et,
2540                                      struct ocfs2_path *path)
2541 {
2542         int i, idx, ret;
2543         struct ocfs2_extent_rec *rec;
2544         struct ocfs2_extent_list *el;
2545         struct ocfs2_extent_block *eb;
2546         u32 range;
2547 
2548         ret = ocfs2_journal_access_path(et->et_ci, handle, path);
2549         if (ret) {
2550                 mlog_errno(ret);
2551                 goto out;
2552         }
2553 
2554         /* Path should always be rightmost. */
2555         eb = (struct ocfs2_extent_block *)path_leaf_bh(path)->b_data;
2556         BUG_ON(eb->h_next_leaf_blk != 0ULL);
2557 
2558         el = &eb->h_list;
2559         BUG_ON(le16_to_cpu(el->l_next_free_rec) == 0);
2560         idx = le16_to_cpu(el->l_next_free_rec) - 1;
2561         rec = &el->l_recs[idx];
2562         range = le32_to_cpu(rec->e_cpos) + ocfs2_rec_clusters(el, rec);
2563 
2564         for (i = 0; i < path->p_tree_depth; i++) {
2565                 el = path->p_node[i].el;
2566                 idx = le16_to_cpu(el->l_next_free_rec) - 1;
2567                 rec = &el->l_recs[idx];
2568 
2569                 rec->e_int_clusters = cpu_to_le32(range);
2570                 le32_add_cpu(&rec->e_int_clusters, -le32_to_cpu(rec->e_cpos));
2571 
2572                 ocfs2_journal_dirty(handle, path->p_node[i].bh);
2573         }
2574 out:
2575         return ret;
2576 }
2577 
2578 static void ocfs2_unlink_path(handle_t *handle,
2579                               struct ocfs2_extent_tree *et,
2580                               struct ocfs2_cached_dealloc_ctxt *dealloc,
2581                               struct ocfs2_path *path, int unlink_start)
2582 {
2583         int ret, i;
2584         struct ocfs2_extent_block *eb;
2585         struct ocfs2_extent_list *el;
2586         struct buffer_head *bh;
2587 
2588         for(i = unlink_start; i < path_num_items(path); i++) {
2589                 bh = path->p_node[i].bh;
2590 
2591                 eb = (struct ocfs2_extent_block *)bh->b_data;
2592                 /*
2593                  * Not all nodes might have had their final count
2594                  * decremented by the caller - handle this here.
2595                  */
2596                 el = &eb->h_list;
2597                 if (le16_to_cpu(el->l_next_free_rec) > 1) {
2598                         mlog(ML_ERROR,
2599                              "Inode %llu, attempted to remove extent block "
2600                              "%llu with %u records\n",
2601                              (unsigned long long)ocfs2_metadata_cache_owner(et->et_ci),
2602                              (unsigned long long)le64_to_cpu(eb->h_blkno),
2603                              le16_to_cpu(el->l_next_free_rec));
2604 
2605                         ocfs2_journal_dirty(handle, bh);
2606                         ocfs2_remove_from_cache(et->et_ci, bh);
2607                         continue;
2608                 }
2609 
2610                 el->l_next_free_rec = 0;
2611                 memset(&el->l_recs[0], 0, sizeof(struct ocfs2_extent_rec));
2612 
2613                 ocfs2_journal_dirty(handle, bh);
2614 
2615                 ret = ocfs2_cache_extent_block_free(dealloc, eb);
2616                 if (ret)
2617                         mlog_errno(ret);
2618 
2619                 ocfs2_remove_from_cache(et->et_ci, bh);
2620         }
2621 }
2622 
2623 static void ocfs2_unlink_subtree(handle_t *handle,
2624                                  struct ocfs2_extent_tree *et,
2625                                  struct ocfs2_path *left_path,
2626                                  struct ocfs2_path *right_path,
2627                                  int subtree_index,
2628                                  struct ocfs2_cached_dealloc_ctxt *dealloc)
2629 {
2630         int i;
2631         struct buffer_head *root_bh = left_path->p_node[subtree_index].bh;
2632         struct ocfs2_extent_list *root_el = left_path->p_node[subtree_index].el;
2633         struct ocfs2_extent_block *eb;
2634 
2635         eb = (struct ocfs2_extent_block *)right_path->p_node[subtree_index + 1].bh->b_data;
2636 
2637         for(i = 1; i < le16_to_cpu(root_el->l_next_free_rec); i++)
2638                 if (root_el->l_recs[i].e_blkno == eb->h_blkno)
2639                         break;
2640 
2641         BUG_ON(i >= le16_to_cpu(root_el->l_next_free_rec));
2642 
2643         memset(&root_el->l_recs[i], 0, sizeof(struct ocfs2_extent_rec));
2644         le16_add_cpu(&root_el->l_next_free_rec, -1);
2645 
2646         eb = (struct ocfs2_extent_block *)path_leaf_bh(left_path)->b_data;
2647         eb->h_next_leaf_blk = 0;
2648 
2649         ocfs2_journal_dirty(handle, root_bh);
2650         ocfs2_journal_dirty(handle, path_leaf_bh(left_path));
2651 
2652         ocfs2_unlink_path(handle, et, dealloc, right_path,
2653                           subtree_index + 1);
2654 }
2655 
2656 static int ocfs2_rotate_subtree_left(handle_t *handle,
2657                                      struct ocfs2_extent_tree *et,
2658                                      struct ocfs2_path *left_path,
2659                                      struct ocfs2_path *right_path,
2660                                      int subtree_index,
2661                                      struct ocfs2_cached_dealloc_ctxt *dealloc,
2662                                      int *deleted)
2663 {
2664         int ret, i, del_right_subtree = 0, right_has_empty = 0;
2665         struct buffer_head *root_bh, *et_root_bh = path_root_bh(right_path);
2666         struct ocfs2_extent_list *right_leaf_el, *left_leaf_el;
2667         struct ocfs2_extent_block *eb;
2668 
2669         *deleted = 0;
2670 
2671         right_leaf_el = path_leaf_el(right_path);
2672         left_leaf_el = path_leaf_el(left_path);
2673         root_bh = left_path->p_node[subtree_index].bh;
2674         BUG_ON(root_bh != right_path->p_node[subtree_index].bh);
2675 
2676         if (!ocfs2_is_empty_extent(&left_leaf_el->l_recs[0]))
2677                 return 0;
2678 
2679         eb = (struct ocfs2_extent_block *)path_leaf_bh(right_path)->b_data;
2680         if (ocfs2_is_empty_extent(&right_leaf_el->l_recs[0])) {
2681                 /*
2682                  * It's legal for us to proceed if the right leaf is
2683                  * the rightmost one and it has an empty extent. There
2684                  * are two cases to handle - whether the leaf will be
2685                  * empty after removal or not. If the leaf isn't empty
2686                  * then just remove the empty extent up front. The
2687                  * next block will handle empty leaves by flagging
2688                  * them for unlink.
2689                  *
2690                  * Non rightmost leaves will throw -EAGAIN and the
2691                  * caller can manually move the subtree and retry.
2692                  */
2693 
2694                 if (eb->h_next_leaf_blk != 0ULL)
2695                         return -EAGAIN;
2696 
2697                 if (le16_to_cpu(right_leaf_el->l_next_free_rec) > 1) {
2698                         ret = ocfs2_journal_access_eb(handle, et->et_ci,
2699                                                       path_leaf_bh(right_path),
2700                                                       OCFS2_JOURNAL_ACCESS_WRITE);
2701                         if (ret) {
2702                                 mlog_errno(ret);
2703                                 goto out;
2704                         }
2705 
2706                         ocfs2_remove_empty_extent(right_leaf_el);
2707                 } else
2708                         right_has_empty = 1;
2709         }
2710 
2711         if (eb->h_next_leaf_blk == 0ULL &&
2712             le16_to_cpu(right_leaf_el->l_next_free_rec) == 1) {
2713                 /*
2714                  * We have to update i_last_eb_blk during the meta
2715                  * data delete.
2716                  */
2717                 ret = ocfs2_et_root_journal_access(handle, et,
2718                                                    OCFS2_JOURNAL_ACCESS_WRITE);
2719                 if (ret) {
2720                         mlog_errno(ret);
2721                         goto out;
2722                 }
2723 
2724                 del_right_subtree = 1;
2725         }
2726 
2727         /*
2728          * Getting here with an empty extent in the right path implies
2729          * that it's the rightmost path and will be deleted.
2730          */
2731         BUG_ON(right_has_empty && !del_right_subtree);
2732 
2733         ret = ocfs2_path_bh_journal_access(handle, et->et_ci, right_path,
2734                                            subtree_index);
2735         if (ret) {
2736                 mlog_errno(ret);
2737                 goto out;
2738         }
2739 
2740         for(i = subtree_index + 1; i < path_num_items(right_path); i++) {
2741                 ret = ocfs2_path_bh_journal_access(handle, et->et_ci,
2742                                                    right_path, i);
2743                 if (ret) {
2744                         mlog_errno(ret);
2745                         goto out;
2746                 }
2747 
2748                 ret = ocfs2_path_bh_journal_access(handle, et->et_ci,
2749                                                    left_path, i);
2750                 if (ret) {
2751                         mlog_errno(ret);
2752                         goto out;
2753                 }
2754         }
2755 
2756         if (!right_has_empty) {
2757                 /*
2758                  * Only do this if we're moving a real
2759                  * record. Otherwise, the action is delayed until
2760                  * after removal of the right path in which case we
2761                  * can do a simple shift to remove the empty extent.
2762                  */
2763                 ocfs2_rotate_leaf(left_leaf_el, &right_leaf_el->l_recs[0]);
2764                 memset(&right_leaf_el->l_recs[0], 0,
2765                        sizeof(struct ocfs2_extent_rec));
2766         }
2767         if (eb->h_next_leaf_blk == 0ULL) {
2768                 /*
2769                  * Move recs over to get rid of empty extent, decrease
2770                  * next_free. This is allowed to remove the last
2771                  * extent in our leaf (setting l_next_free_rec to
2772                  * zero) - the delete code below won't care.
2773                  */
2774                 ocfs2_remove_empty_extent(right_leaf_el);
2775         }
2776 
2777         ocfs2_journal_dirty(handle, path_leaf_bh(left_path));
2778         ocfs2_journal_dirty(handle, path_leaf_bh(right_path));
2779 
2780         if (del_right_subtree) {
2781                 ocfs2_unlink_subtree(handle, et, left_path, right_path,
2782                                      subtree_index, dealloc);
2783                 ret = ocfs2_update_edge_lengths(handle, et, left_path);
2784                 if (ret) {
2785                         mlog_errno(ret);
2786                         goto out;
2787                 }
2788 
2789                 eb = (struct ocfs2_extent_block *)path_leaf_bh(left_path)->b_data;
2790                 ocfs2_et_set_last_eb_blk(et, le64_to_cpu(eb->h_blkno));
2791 
2792                 /*
2793                  * Removal of the extent in the left leaf was skipped
2794                  * above so we could delete the right path
2795                  * 1st.
2796                  */
2797                 if (right_has_empty)
2798                         ocfs2_remove_empty_extent(left_leaf_el);
2799 
2800                 ocfs2_journal_dirty(handle, et_root_bh);
2801 
2802                 *deleted = 1;
2803         } else
2804                 ocfs2_complete_edge_insert(handle, left_path, right_path,
2805                                            subtree_index);
2806 
2807 out:
2808         return ret;
2809 }
2810 
2811 /*
2812  * Given a full path, determine what cpos value would return us a path
2813  * containing the leaf immediately to the right of the current one.
2814  *
2815  * Will return zero if the path passed in is already the rightmost path.
2816  *
2817  * This looks similar, but is subtly different to
2818  * ocfs2_find_cpos_for_left_leaf().
2819  */
2820 int ocfs2_find_cpos_for_right_leaf(struct super_block *sb,
2821                                    struct ocfs2_path *path, u32 *cpos)
2822 {
2823         int i, j, ret = 0;
2824         u64 blkno;
2825         struct ocfs2_extent_list *el;
2826 
2827         *cpos = 0;
2828 
2829         if (path->p_tree_depth == 0)
2830                 return 0;
2831 
2832         blkno = path_leaf_bh(path)->b_blocknr;
2833 
2834         /* Start at the tree node just above the leaf and work our way up. */
2835         i = path->p_tree_depth - 1;
2836         while (i >= 0) {
2837                 int next_free;
2838 
2839                 el = path->p_node[i].el;
2840 
2841                 /*
2842                  * Find the extent record just after the one in our
2843                  * path.
2844                  */
2845                 next_free = le16_to_cpu(el->l_next_free_rec);
2846                 for(j = 0; j < le16_to_cpu(el->l_next_free_rec); j++) {
2847                         if (le64_to_cpu(el->l_recs[j].e_blkno) == blkno) {
2848                                 if (j == (next_free - 1)) {
2849                                         if (i == 0) {
2850                                                 /*
2851                                                  * We've determined that the
2852                                                  * path specified is already
2853                                                  * the rightmost one - return a
2854                                                  * cpos of zero.
2855                                                  */
2856                                                 goto out;
2857                                         }
2858                                         /*
2859                                          * The rightmost record points to our
2860                                          * leaf - we need to travel up the
2861                                          * tree one level.
2862                                          */
2863                                         goto next_node;
2864                                 }
2865 
2866                                 *cpos = le32_to_cpu(el->l_recs[j + 1].e_cpos);
2867                                 goto out;
2868                         }
2869                 }
2870 
2871                 /*
2872                  * If we got here, we never found a valid node where
2873                  * the tree indicated one should be.
2874                  */
2875                 ocfs2_error(sb, "Invalid extent tree at extent block %llu\n",
2876                             (unsigned long long)blkno);
2877                 ret = -EROFS;
2878                 goto out;
2879 
2880 next_node:
2881                 blkno = path->p_node[i].bh->b_blocknr;
2882                 i--;
2883         }
2884 
2885 out:
2886         return ret;
2887 }
2888 
2889 static int ocfs2_rotate_rightmost_leaf_left(handle_t *handle,
2890                                             struct ocfs2_extent_tree *et,
2891                                             struct ocfs2_path *path)
2892 {
2893         int ret;
2894         struct buffer_head *bh = path_leaf_bh(path);
2895         struct ocfs2_extent_list *el = path_leaf_el(path);
2896 
2897         if (!ocfs2_is_empty_extent(&el->l_recs[0]))
2898                 return 0;
2899 
2900         ret = ocfs2_path_bh_journal_access(handle, et->et_ci, path,
2901                                            path_num_items(path) - 1);
2902         if (ret) {
2903                 mlog_errno(ret);
2904                 goto out;
2905         }
2906 
2907         ocfs2_remove_empty_extent(el);
2908         ocfs2_journal_dirty(handle, bh);
2909 
2910 out:
2911         return ret;
2912 }
2913 
2914 static int __ocfs2_rotate_tree_left(handle_t *handle,
2915                                     struct ocfs2_extent_tree *et,
2916                                     int orig_credits,
2917                                     struct ocfs2_path *path,
2918                                     struct ocfs2_cached_dealloc_ctxt *dealloc,
2919                                     struct ocfs2_path **empty_extent_path)
2920 {
2921         int ret, subtree_root, deleted;
2922         u32 right_cpos;
2923         struct ocfs2_path *left_path = NULL;
2924         struct ocfs2_path *right_path = NULL;
2925         struct super_block *sb = ocfs2_metadata_cache_get_super(et->et_ci);
2926 
2927         if (!ocfs2_is_empty_extent(&(path_leaf_el(path)->l_recs[0])))
2928                 return 0;
2929 
2930         *empty_extent_path = NULL;
2931 
2932         ret = ocfs2_find_cpos_for_right_leaf(sb, path, &right_cpos);
2933         if (ret) {
2934                 mlog_errno(ret);
2935                 goto out;
2936         }
2937 
2938         left_path = ocfs2_new_path_from_path(path);
2939         if (!left_path) {
2940                 ret = -ENOMEM;
2941                 mlog_errno(ret);
2942                 goto out;
2943         }
2944 
2945         ocfs2_cp_path(left_path, path);
2946 
2947         right_path = ocfs2_new_path_from_path(path);
2948         if (!right_path) {
2949                 ret = -ENOMEM;
2950                 mlog_errno(ret);
2951                 goto out;
2952         }
2953 
2954         while (right_cpos) {
2955                 ret = ocfs2_find_path(et->et_ci, right_path, right_cpos);
2956                 if (ret) {
2957                         mlog_errno(ret);
2958                         goto out;
2959                 }
2960 
2961                 subtree_root = ocfs2_find_subtree_root(et, left_path,
2962                                                        right_path);
2963 
2964                 trace_ocfs2_rotate_subtree(subtree_root,
2965                      (unsigned long long)
2966                      right_path->p_node[subtree_root].bh->b_blocknr,
2967                      right_path->p_tree_depth);
2968 
2969                 ret = ocfs2_extend_rotate_transaction(handle, 0,
2970                                                       orig_credits, left_path);
2971                 if (ret) {
2972                         mlog_errno(ret);
2973                         goto out;
2974                 }
2975 
2976                 /*
2977                  * Caller might still want to make changes to the
2978                  * tree root, so re-add it to the journal here.
2979                  */
2980                 ret = ocfs2_path_bh_journal_access(handle, et->et_ci,
2981                                                    left_path, 0);
2982                 if (ret) {
2983                         mlog_errno(ret);
2984                         goto out;
2985                 }
2986 
2987                 ret = ocfs2_rotate_subtree_left(handle, et, left_path,
2988                                                 right_path, subtree_root,
2989                                                 dealloc, &deleted);
2990                 if (ret == -EAGAIN) {
2991                         /*
2992                          * The rotation has to temporarily stop due to
2993                          * the right subtree having an empty
2994                          * extent. Pass it back to the caller for a
2995                          * fixup.
2996                          */
2997                         *empty_extent_path = right_path;
2998                         right_path = NULL;
2999                         goto out;
3000                 }
3001                 if (ret) {
3002                         mlog_errno(ret);
3003                         goto out;
3004                 }
3005 
3006                 /*
3007                  * The subtree rotate might have removed records on
3008                  * the rightmost edge. If so, then rotation is
3009                  * complete.
3010                  */
3011                 if (deleted)
3012                         break;
3013 
3014                 ocfs2_mv_path(left_path, right_path);
3015 
3016                 ret = ocfs2_find_cpos_for_right_leaf(sb, left_path,
3017                                                      &right_cpos);
3018                 if (ret) {
3019                         mlog_errno(ret);
3020                         goto out;
3021                 }
3022         }
3023 
3024 out:
3025         ocfs2_free_path(right_path);
3026         ocfs2_free_path(left_path);
3027 
3028         return ret;
3029 }
3030 
3031 static int ocfs2_remove_rightmost_path(handle_t *handle,
3032                                 struct ocfs2_extent_tree *et,
3033                                 struct ocfs2_path *path,
3034                                 struct ocfs2_cached_dealloc_ctxt *dealloc)
3035 {
3036         int ret, subtree_index;
3037         u32 cpos;
3038         struct ocfs2_path *left_path = NULL;
3039         struct ocfs2_extent_block *eb;
3040         struct ocfs2_extent_list *el;
3041 
3042         ret = ocfs2_et_sanity_check(et);
3043         if (ret)
3044                 goto out;
3045 
3046         ret = ocfs2_journal_access_path(et->et_ci, handle, path);
3047         if (ret) {
3048                 mlog_errno(ret);
3049                 goto out;
3050         }
3051 
3052         ret = ocfs2_find_cpos_for_left_leaf(ocfs2_metadata_cache_get_super(et->et_ci),
3053                                             path, &cpos);
3054         if (ret) {
3055                 mlog_errno(ret);
3056                 goto out;
3057         }
3058 
3059         if (cpos) {
3060                 /*
3061                  * We have a path to the left of this one - it needs
3062                  * an update too.
3063                  */
3064                 left_path = ocfs2_new_path_from_path(path);
3065                 if (!left_path) {
3066                         ret = -ENOMEM;
3067                         mlog_errno(ret);
3068                         goto out;
3069                 }
3070 
3071                 ret = ocfs2_find_path(et->et_ci, left_path, cpos);
3072                 if (ret) {
3073                         mlog_errno(ret);
3074                         goto out;
3075                 }
3076 
3077                 ret = ocfs2_journal_access_path(et->et_ci, handle, left_path);
3078                 if (ret) {
3079                         mlog_errno(ret);
3080                         goto out;
3081                 }
3082 
3083                 subtree_index = ocfs2_find_subtree_root(et, left_path, path);
3084 
3085                 ocfs2_unlink_subtree(handle, et, left_path, path,
3086                                      subtree_index, dealloc);
3087                 ret = ocfs2_update_edge_lengths(handle, et, left_path);
3088                 if (ret) {
3089                         mlog_errno(ret);
3090                         goto out;
3091                 }
3092 
3093                 eb = (struct ocfs2_extent_block *)path_leaf_bh(left_path)->b_data;
3094                 ocfs2_et_set_last_eb_blk(et, le64_to_cpu(eb->h_blkno));
3095         } else {
3096                 /*
3097                  * 'path' is also the leftmost path which
3098                  * means it must be the only one. This gets
3099                  * handled differently because we want to
3100                  * revert the root back to having extents
3101                  * in-line.
3102                  */
3103                 ocfs2_unlink_path(handle, et, dealloc, path, 1);
3104 
3105                 el = et->et_root_el;
3106                 el->l_tree_depth = 0;
3107                 el->l_next_free_rec = 0;
3108                 memset(&el->l_recs[0], 0, sizeof(struct ocfs2_extent_rec));
3109 
3110                 ocfs2_et_set_last_eb_blk(et, 0);
3111         }
3112 
3113         ocfs2_journal_dirty(handle, path_root_bh(path));
3114 
3115 out:
3116         ocfs2_free_path(left_path);
3117         return ret;
3118 }
3119 
3120 static int ocfs2_remove_rightmost_empty_extent(struct ocfs2_super *osb,
3121                                 struct ocfs2_extent_tree *et,
3122                                 struct ocfs2_path *path,
3123                                 struct ocfs2_cached_dealloc_ctxt *dealloc)
3124 {
3125         handle_t *handle;
3126         int ret;
3127         int credits = path->p_tree_depth * 2 + 1;
3128 
3129         handle = ocfs2_start_trans(osb, credits);
3130         if (IS_ERR(handle)) {
3131                 ret = PTR_ERR(handle);
3132                 mlog_errno(ret);
3133                 return ret;
3134         }
3135 
3136         ret = ocfs2_remove_rightmost_path(handle, et, path, dealloc);
3137         if (ret)
3138                 mlog_errno(ret);
3139 
3140         ocfs2_commit_trans(osb, handle);
3141         return ret;
3142 }
3143 
3144 /*
3145  * Left rotation of btree records.
3146  *
3147  * In many ways, this is (unsurprisingly) the opposite of right
3148  * rotation. We start at some non-rightmost path containing an empty
3149  * extent in the leaf block. The code works its way to the rightmost
3150  * path by rotating records to the left in every subtree.
3151  *
3152  * This is used by any code which reduces the number of extent records
3153  * in a leaf. After removal, an empty record should be placed in the
3154  * leftmost list position.
3155  *
3156  * This won't handle a length update of the rightmost path records if
3157  * the rightmost tree leaf record is removed so the caller is
3158  * responsible for detecting and correcting that.
3159  */
3160 static int ocfs2_rotate_tree_left(handle_t *handle,
3161                                   struct ocfs2_extent_tree *et,
3162                                   struct ocfs2_path *path,
3163                                   struct ocfs2_cached_dealloc_ctxt *dealloc)
3164 {
3165         int ret, orig_credits = handle->h_buffer_credits;
3166         struct ocfs2_path *tmp_path = NULL, *restart_path = NULL;
3167         struct ocfs2_extent_block *eb;
3168         struct ocfs2_extent_list *el;
3169 
3170         el = path_leaf_el(path);
3171         if (!ocfs2_is_empty_extent(&el->l_recs[0]))
3172                 return 0;
3173 
3174         if (path->p_tree_depth == 0) {
3175 rightmost_no_delete:
3176                 /*
3177                  * Inline extents. This is trivially handled, so do
3178                  * it up front.
3179                  */
3180                 ret = ocfs2_rotate_rightmost_leaf_left(handle, et, path);
3181                 if (ret)
3182                         mlog_errno(ret);
3183                 goto out;
3184         }
3185 
3186         /*
3187          * Handle rightmost branch now. There's several cases:
3188          *  1) simple rotation leaving records in there. That's trivial.
3189          *  2) rotation requiring a branch delete - there's no more
3190          *     records left. Two cases of this:
3191          *     a) There are branches to the left.
3192          *     b) This is also the leftmost (the only) branch.
3193          *
3194          *  1) is handled via ocfs2_rotate_rightmost_leaf_left()
3195          *  2a) we need the left branch so that we can update it with the unlink
3196          *  2b) we need to bring the root back to inline extents.
3197          */
3198 
3199         eb = (struct ocfs2_extent_block *)path_leaf_bh(path)->b_data;
3200         el = &eb->h_list;
3201         if (eb->h_next_leaf_blk == 0) {
3202                 /*
3203                  * This gets a bit tricky if we're going to delete the
3204                  * rightmost path. Get the other cases out of the way
3205                  * 1st.
3206                  */
3207                 if (le16_to_cpu(el->l_next_free_rec) > 1)
3208                         goto rightmost_no_delete;
3209 
3210                 if (le16_to_cpu(el->l_next_free_rec) == 0) {
3211                         ret = ocfs2_error(ocfs2_metadata_cache_get_super(et->et_ci),
3212                                         "Owner %llu has empty extent block at %llu\n",
3213                                         (unsigned long long)ocfs2_metadata_cache_owner(et->et_ci),
3214                                         (unsigned long long)le64_to_cpu(eb->h_blkno));
3215                         goto out;
3216                 }
3217 
3218                 /*
3219                  * XXX: The caller can not trust "path" any more after
3220                  * this as it will have been deleted. What do we do?
3221                  *
3222                  * In theory the rotate-for-merge code will never get
3223                  * here because it'll always ask for a rotate in a
3224                  * nonempty list.
3225                  */
3226 
3227                 ret = ocfs2_remove_rightmost_path(handle, et, path,
3228                                                   dealloc);
3229                 if (ret)
3230                         mlog_errno(ret);
3231                 goto out;
3232         }
3233 
3234         /*
3235          * Now we can loop, remembering the path we get from -EAGAIN
3236          * and restarting from there.
3237          */
3238 try_rotate:
3239         ret = __ocfs2_rotate_tree_left(handle, et, orig_credits, path,
3240                                        dealloc, &restart_path);
3241         if (ret && ret != -EAGAIN) {
3242                 mlog_errno(ret);
3243                 goto out;
3244         }
3245 
3246         while (ret == -EAGAIN) {
3247                 tmp_path = restart_path;
3248                 restart_path = NULL;
3249 
3250                 ret = __ocfs2_rotate_tree_left(handle, et, orig_credits,
3251                                                tmp_path, dealloc,
3252                                                &restart_path);
3253                 if (ret && ret != -EAGAIN) {
3254                         mlog_errno(ret);
3255                         goto out;
3256                 }
3257 
3258                 ocfs2_free_path(tmp_path);
3259                 tmp_path = NULL;
3260 
3261                 if (ret == 0)
3262                         goto try_rotate;
3263         }
3264 
3265 out:
3266         ocfs2_free_path(tmp_path);
3267         ocfs2_free_path(restart_path);
3268         return ret;
3269 }
3270 
3271 static void ocfs2_cleanup_merge(struct ocfs2_extent_list *el,
3272                                 int index)
3273 {
3274         struct ocfs2_extent_rec *rec = &el->l_recs[index];
3275         unsigned int size;
3276 
3277         if (rec->e_leaf_clusters == 0) {
3278                 /*
3279                  * We consumed all of the merged-from record. An empty
3280                  * extent cannot exist anywhere but the 1st array
3281                  * position, so move things over if the merged-from
3282                  * record doesn't occupy that position.
3283                  *
3284                  * This creates a new empty extent so the caller
3285                  * should be smart enough to have removed any existing
3286                  * ones.
3287                  */
3288                 if (index > 0) {
3289                         BUG_ON(ocfs2_is_empty_extent(&el->l_recs[0]));
3290                         size = index * sizeof(struct ocfs2_extent_rec);
3291                         memmove(&el->l_recs[1], &el->l_recs[0], size);
3292                 }
3293 
3294                 /*
3295                  * Always memset - the caller doesn't check whether it
3296                  * created an empty extent, so there could be junk in
3297                  * the other fields.
3298                  */
3299                 memset(&el->l_recs[0], 0, sizeof(struct ocfs2_extent_rec));
3300         }
3301 }
3302 
3303 static int ocfs2_get_right_path(struct ocfs2_extent_tree *et,
3304                                 struct ocfs2_path *left_path,
3305                                 struct ocfs2_path **ret_right_path)
3306 {
3307         int ret;
3308         u32 right_cpos;
3309         struct ocfs2_path *right_path = NULL;
3310         struct ocfs2_extent_list *left_el;
3311 
3312         *ret_right_path = NULL;
3313 
3314         /* This function shouldn't be called for non-trees. */
3315         BUG_ON(left_path->p_tree_depth == 0);
3316 
3317         left_el = path_leaf_el(left_path);
3318         BUG_ON(left_el->l_next_free_rec != left_el->l_count);
3319 
3320         ret = ocfs2_find_cpos_for_right_leaf(ocfs2_metadata_cache_get_super(et->et_ci),
3321                                              left_path, &right_cpos);
3322         if (ret) {
3323                 mlog_errno(ret);
3324                 goto out;
3325         }
3326 
3327         /* This function shouldn't be called for the rightmost leaf. */
3328         BUG_ON(right_cpos == 0);
3329 
3330         right_path = ocfs2_new_path_from_path(left_path);
3331         if (!right_path) {
3332                 ret = -ENOMEM;
3333                 mlog_errno(ret);
3334                 goto out;
3335         }
3336 
3337         ret = ocfs2_find_path(et->et_ci, right_path, right_cpos);
3338         if (ret) {
3339                 mlog_errno(ret);
3340                 goto out;
3341         }
3342 
3343         *ret_right_path = right_path;
3344 out:
3345         if (ret)
3346                 ocfs2_free_path(right_path);
3347         return ret;
3348 }
3349 
3350 /*
3351  * Remove split_rec clusters from the record at index and merge them
3352  * onto the beginning of the record "next" to it.
3353  * For index < l_count - 1, the next means the extent rec at index + 1.
3354  * For index == l_count - 1, the "next" means the 1st extent rec of the
3355  * next extent block.
3356  */
3357 static int ocfs2_merge_rec_right(struct ocfs2_path *left_path,
3358                                  handle_t *handle,
3359                                  struct ocfs2_extent_tree *et,
3360                                  struct ocfs2_extent_rec *split_rec,
3361                                  int index)
3362 {
3363         int ret, next_free, i;
3364         unsigned int split_clusters = le16_to_cpu(split_rec->e_leaf_clusters);
3365         struct ocfs2_extent_rec *left_rec;
3366         struct ocfs2_extent_rec *right_rec;
3367         struct ocfs2_extent_list *right_el;
3368         struct ocfs2_path *right_path = NULL;
3369         int subtree_index = 0;
3370         struct ocfs2_extent_list *el = path_leaf_el(left_path);
3371         struct buffer_head *bh = path_leaf_bh(left_path);
3372         struct buffer_head *root_bh = NULL;
3373 
3374         BUG_ON(index >= le16_to_cpu(el->l_next_free_rec));
3375         left_rec = &el->l_recs[index];
3376 
3377         if (index == le16_to_cpu(el->l_next_free_rec) - 1 &&
3378             le16_to_cpu(el->l_next_free_rec) == le16_to_cpu(el->l_count)) {
3379                 /* we meet with a cross extent block merge. */
3380                 ret = ocfs2_get_right_path(et, left_path, &right_path);
3381                 if (ret) {
3382                         mlog_errno(ret);
3383                         return ret;
3384                 }
3385 
3386                 right_el = path_leaf_el(right_path);
3387                 next_free = le16_to_cpu(right_el->l_next_free_rec);
3388                 BUG_ON(next_free <= 0);
3389                 right_rec = &right_el->l_recs[0];
3390                 if (ocfs2_is_empty_extent(right_rec)) {
3391                         BUG_ON(next_free <= 1);
3392                         right_rec = &right_el->l_recs[1];
3393                 }
3394 
3395                 BUG_ON(le32_to_cpu(left_rec->e_cpos) +
3396                        le16_to_cpu(left_rec->e_leaf_clusters) !=
3397                        le32_to_cpu(right_rec->e_cpos));
3398 
3399                 subtree_index = ocfs2_find_subtree_root(et, left_path,
3400                                                         right_path);
3401 
3402                 ret = ocfs2_extend_rotate_transaction(handle, subtree_index,
3403                                                       handle->h_buffer_credits,
3404                                                       right_path);
3405                 if (ret) {
3406                         mlog_errno(ret);
3407                         goto out;
3408                 }
3409 
3410                 root_bh = left_path->p_node[subtree_index].bh;
3411                 BUG_ON(root_bh != right_path->p_node[subtree_index].bh);
3412 
3413                 ret = ocfs2_path_bh_journal_access(handle, et->et_ci, right_path,
3414                                                    subtree_index);
3415                 if (ret) {
3416                         mlog_errno(ret);
3417                         goto out;
3418                 }
3419 
3420                 for (i = subtree_index + 1;
3421                      i < path_num_items(right_path); i++) {
3422                         ret = ocfs2_path_bh_journal_access(handle, et->et_ci,
3423                                                            right_path, i);
3424                         if (ret) {
3425                                 mlog_errno(ret);
3426                                 goto out;
3427                         }
3428 
3429                         ret = ocfs2_path_bh_journal_access(handle, et->et_ci,
3430                                                            left_path, i);
3431                         if (ret) {
3432                                 mlog_errno(ret);
3433                                 goto out;
3434                         }
3435                 }
3436 
3437         } else {
3438                 BUG_ON(index == le16_to_cpu(el->l_next_free_rec) - 1);
3439                 right_rec = &el->l_recs[index + 1];
3440         }
3441 
3442         ret = ocfs2_path_bh_journal_access(handle, et->et_ci, left_path,
3443                                            path_num_items(left_path) - 1);
3444         if (ret) {
3445                 mlog_errno(ret);
3446                 goto out;
3447         }
3448 
3449         le16_add_cpu(&left_rec->e_leaf_clusters, -split_clusters);
3450 
3451         le32_add_cpu(&right_rec->e_cpos, -split_clusters);
3452         le64_add_cpu(&right_rec->e_blkno,
3453                      -ocfs2_clusters_to_blocks(ocfs2_metadata_cache_get_super(et->et_ci),
3454                                                split_clusters));
3455         le16_add_cpu(&right_rec->e_leaf_clusters, split_clusters);
3456 
3457         ocfs2_cleanup_merge(el, index);
3458 
3459         ocfs2_journal_dirty(handle, bh);
3460         if (right_path) {
3461                 ocfs2_journal_dirty(handle, path_leaf_bh(right_path));
3462                 ocfs2_complete_edge_insert(handle, left_path, right_path,
3463                                            subtree_index);
3464         }
3465 out:
3466         ocfs2_free_path(right_path);
3467         return ret;
3468 }
3469 
3470 static int ocfs2_get_left_path(struct ocfs2_extent_tree *et,
3471                                struct ocfs2_path *right_path,
3472                                struct ocfs2_path **ret_left_path)
3473 {
3474         int ret;
3475         u32 left_cpos;
3476         struct ocfs2_path *left_path = NULL;
3477 
3478         *ret_left_path = NULL;
3479 
3480         /* This function shouldn't be called for non-trees. */
3481         BUG_ON(right_path->p_tree_depth == 0);
3482 
3483         ret = ocfs2_find_cpos_for_left_leaf(ocfs2_metadata_cache_get_super(et->et_ci),
3484                                             right_path, &left_cpos);
3485         if (ret) {
3486                 mlog_errno(ret);
3487                 goto out;
3488         }
3489 
3490         /* This function shouldn't be called for the leftmost leaf. */
3491         BUG_ON(left_cpos == 0);
3492 
3493         left_path = ocfs2_new_path_from_path(right_path);
3494         if (!left_path) {
3495                 ret = -ENOMEM;
3496                 mlog_errno(ret);
3497                 goto out;
3498         }
3499 
3500         ret = ocfs2_find_path(et->et_ci, left_path, left_cpos);
3501         if (ret) {
3502                 mlog_errno(ret);
3503                 goto out;
3504         }
3505 
3506         *ret_left_path = left_path;
3507 out:
3508         if (ret)
3509                 ocfs2_free_path(left_path);
3510         return ret;
3511 }
3512 
3513 /*
3514  * Remove split_rec clusters from the record at index and merge them
3515  * onto the tail of the record "before" it.
3516  * For index > 0, the "before" means the extent rec at index - 1.
3517  *
3518  * For index == 0, the "before" means the last record of the previous
3519  * extent block. And there is also a situation that we may need to
3520  * remove the rightmost leaf extent block in the right_path and change
3521  * the right path to indicate the new rightmost path.
3522  */
3523 static int ocfs2_merge_rec_left(struct ocfs2_path *right_path,
3524                                 handle_t *handle,
3525                                 struct ocfs2_extent_tree *et,
3526                                 struct ocfs2_extent_rec *split_rec,
3527                                 struct ocfs2_cached_dealloc_ctxt *dealloc,
3528                                 int index)
3529 {
3530         int ret, i, subtree_index = 0, has_empty_extent = 0;
3531         unsigned int split_clusters = le16_to_cpu(split_rec->e_leaf_clusters);
3532         struct ocfs2_extent_rec *left_rec;
3533         struct ocfs2_extent_rec *right_rec;
3534         struct ocfs2_extent_list *el = path_leaf_el(right_path);
3535         struct buffer_head *bh = path_leaf_bh(right_path);
3536         struct buffer_head *root_bh = NULL;
3537         struct ocfs2_path *left_path = NULL;
3538         struct ocfs2_extent_list *left_el;
3539 
3540         BUG_ON(index < 0);
3541 
3542         right_rec = &el->l_recs[index];
3543         if (index == 0) {
3544                 /* we meet with a cross extent block merge. */
3545                 ret = ocfs2_get_left_path(et, right_path, &left_path);
3546                 if (ret) {
3547                         mlog_errno(ret);
3548                         return ret;
3549                 }
3550 
3551                 left_el = path_leaf_el(left_path);
3552                 BUG_ON(le16_to_cpu(left_el->l_next_free_rec) !=
3553                        le16_to_cpu(left_el->l_count));
3554 
3555                 left_rec = &left_el->l_recs[
3556                                 le16_to_cpu(left_el->l_next_free_rec) - 1];
3557                 BUG_ON(le32_to_cpu(left_rec->e_cpos) +
3558                        le16_to_cpu(left_rec->e_leaf_clusters) !=
3559                        le32_to_cpu(split_rec->e_cpos));
3560 
3561                 subtree_index = ocfs2_find_subtree_root(et, left_path,
3562                                                         right_path);
3563 
3564                 ret = ocfs2_extend_rotate_transaction(handle, subtree_index,
3565                                                       handle->h_buffer_credits,
3566                                                       left_path);
3567                 if (ret) {
3568                         mlog_errno(ret);
3569                         goto out;
3570                 }
3571 
3572                 root_bh = left_path->p_node[subtree_index].bh;
3573                 BUG_ON(root_bh != right_path->p_node[subtree_index].bh);
3574 
3575                 ret = ocfs2_path_bh_journal_access(handle, et->et_ci, right_path,
3576                                                    subtree_index);
3577                 if (ret) {
3578                         mlog_errno(ret);
3579                         goto out;
3580                 }
3581 
3582                 for (i = subtree_index + 1;
3583                      i < path_num_items(right_path); i++) {
3584                         ret = ocfs2_path_bh_journal_access(handle, et->et_ci,
3585                                                            right_path, i);
3586                         if (ret) {
3587                                 mlog_errno(ret);
3588                                 goto out;
3589                         }
3590 
3591                         ret = ocfs2_path_bh_journal_access(handle, et->et_ci,
3592                                                            left_path, i);
3593                         if (ret) {
3594                                 mlog_errno(ret);
3595                                 goto out;
3596                         }
3597                 }
3598         } else {
3599                 left_rec = &el->l_recs[index - 1];
3600                 if (ocfs2_is_empty_extent(&el->l_recs[0]))
3601                         has_empty_extent = 1;
3602         }
3603 
3604         ret = ocfs2_path_bh_journal_access(handle, et->et_ci, right_path,
3605                                            path_num_items(right_path) - 1);
3606         if (ret) {
3607                 mlog_errno(ret);
3608                 goto out;
3609         }
3610 
3611         if (has_empty_extent && index == 1) {
3612                 /*
3613                  * The easy case - we can just plop the record right in.
3614                  */
3615                 *left_rec = *split_rec;
3616         } else
3617                 le16_add_cpu(&left_rec->e_leaf_clusters, split_clusters);
3618 
3619         le32_add_cpu(&right_rec->e_cpos, split_clusters);
3620         le64_add_cpu(&right_rec->e_blkno,
3621                      ocfs2_clusters_to_blocks(ocfs2_metadata_cache_get_super(et->et_ci),
3622                                               split_clusters));
3623         le16_add_cpu(&right_rec->e_leaf_clusters, -split_clusters);
3624 
3625         ocfs2_cleanup_merge(el, index);
3626 
3627         ocfs2_journal_dirty(handle, bh);
3628         if (left_path) {
3629                 ocfs2_journal_dirty(handle, path_leaf_bh(left_path));
3630 
3631                 /*
3632                  * In the situation that the right_rec is empty and the extent
3633                  * block is empty also,  ocfs2_complete_edge_insert can't handle
3634                  * it and we need to delete the right extent block.
3635                  */
3636                 if (le16_to_cpu(right_rec->e_leaf_clusters) == 0 &&
3637                     le16_to_cpu(el->l_next_free_rec) == 1) {
3638                         /* extend credit for ocfs2_remove_rightmost_path */
3639                         ret = ocfs2_extend_rotate_transaction(handle, 0,
3640                                         handle->h_buffer_credits,
3641                                         right_path);
3642                         if (ret) {
3643                                 mlog_errno(ret);
3644                                 goto out;
3645                         }
3646 
3647                         ret = ocfs2_remove_rightmost_path(handle, et,
3648                                                           right_path,
3649                                                           dealloc);
3650                         if (ret) {
3651                                 mlog_errno(ret);
3652                                 goto out;
3653                         }
3654 
3655                         /* Now the rightmost extent block has been deleted.
3656                          * So we use the new rightmost path.
3657                          */
3658                         ocfs2_mv_path(right_path, left_path);
3659                         left_path = NULL;
3660                 } else
3661                         ocfs2_complete_edge_insert(handle, left_path,
3662                                                    right_path, subtree_index);
3663         }
3664 out:
3665         ocfs2_free_path(left_path);
3666         return ret;
3667 }
3668 
3669 static int ocfs2_try_to_merge_extent(handle_t *handle,
3670                                      struct ocfs2_extent_tree *et,
3671                                      struct ocfs2_path *path,
3672                                      int split_index,
3673                                      struct ocfs2_extent_rec *split_rec,
3674                                      struct ocfs2_cached_dealloc_ctxt *dealloc,
3675                                      struct ocfs2_merge_ctxt *ctxt)
3676 {
3677         int ret = 0;
3678         struct ocfs2_extent_list *el = path_leaf_el(path);
3679         struct ocfs2_extent_rec *rec = &el->l_recs[split_index];
3680 
3681         BUG_ON(ctxt->c_contig_type == CONTIG_NONE);
3682 
3683         if (ctxt->c_split_covers_rec && ctxt->c_has_empty_extent) {
3684                 /* extend credit for ocfs2_remove_rightmost_path */
3685                 ret = ocfs2_extend_rotate_transaction(handle, 0,
3686                                 handle->h_buffer_credits,
3687                                 path);
3688                 if (ret) {
3689                         mlog_errno(ret);
3690                         goto out;
3691                 }
3692                 /*
3693                  * The merge code will need to create an empty
3694                  * extent to take the place of the newly
3695                  * emptied slot. Remove any pre-existing empty
3696                  * extents - having more than one in a leaf is
3697                  * illegal.
3698                  */
3699                 ret = ocfs2_rotate_tree_left(handle, et, path, dealloc);
3700                 if (ret) {
3701                         mlog_errno(ret);
3702                         goto out;
3703                 }
3704                 split_index--;
3705                 rec = &el->l_recs[split_index];
3706         }
3707 
3708         if (ctxt->c_contig_type == CONTIG_LEFTRIGHT) {
3709                 /*
3710                  * Left-right contig implies this.
3711                  */
3712                 BUG_ON(!ctxt->c_split_covers_rec);
3713 
3714                 /*
3715                  * Since the leftright insert always covers the entire
3716                  * extent, this call will delete the insert record
3717                  * entirely, resulting in an empty extent record added to
3718                  * the extent block.
3719                  *
3720                  * Since the adding of an empty extent shifts
3721                  * everything back to the right, there's no need to
3722                  * update split_index here.
3723                  *
3724                  * When the split_index is zero, we need to merge it to the
3725                  * prevoius extent block. It is more efficient and easier
3726                  * if we do merge_right first and merge_left later.
3727                  */
3728                 ret = ocfs2_merge_rec_right(path, handle, et, split_rec,
3729                                             split_index);
3730                 if (ret) {
3731                         mlog_errno(ret);
3732                         goto out;
3733                 }
3734 
3735                 /*
3736                  * We can only get this from logic error above.
3737                  */
3738                 BUG_ON(!ocfs2_is_empty_extent(&el->l_recs[0]));
3739 
3740                 /* extend credit for ocfs2_remove_rightmost_path */
3741                 ret = ocfs2_extend_rotate_transaction(handle, 0,
3742                                         handle->h_buffer_credits,
3743                                         path);
3744                 if (ret) {
3745                         mlog_errno(ret);
3746                         goto out;
3747                 }
3748 
3749                 /* The merge left us with an empty extent, remove it. */
3750                 ret = ocfs2_rotate_tree_left(handle, et, path, dealloc);
3751                 if (ret) {
3752                         mlog_errno(ret);
3753                         goto out;
3754                 }
3755 
3756                 rec = &el->l_recs[split_index];
3757 
3758                 /*
3759                  * Note that we don't pass split_rec here on purpose -
3760                  * we've merged it into the rec already.
3761                  */
3762                 ret = ocfs2_merge_rec_left(path, handle, et, rec,
3763                                            dealloc, split_index);
3764 
3765                 if (ret) {
3766                         mlog_errno(ret);
3767                         goto out;
3768                 }
3769 
3770                 /* extend credit for ocfs2_remove_rightmost_path */
3771                 ret = ocfs2_extend_rotate_transaction(handle, 0,
3772                                 handle->h_buffer_credits,
3773                                 path);
3774                 if (ret) {
3775                         mlog_errno(ret);
3776                         goto out;
3777                 }
3778 
3779                 ret = ocfs2_rotate_tree_left(handle, et, path, dealloc);
3780                 /*
3781                  * Error from this last rotate is not critical, so
3782                  * print but don't bubble it up.
3783                  */
3784                 if (ret)
3785                         mlog_errno(ret);
3786                 ret = 0;
3787         } else {
3788                 /*
3789                  * Merge a record to the left or right.
3790                  *
3791                  * 'contig_type' is relative to the existing record,
3792                  * so for example, if we're "right contig", it's to
3793                  * the record on the left (hence the left merge).
3794                  */
3795                 if (ctxt->c_contig_type == CONTIG_RIGHT) {
3796                         ret = ocfs2_merge_rec_left(path, handle, et,
3797                                                    split_rec, dealloc,
3798                                                    split_index);
3799                         if (ret) {
3800                                 mlog_errno(ret);
3801                                 goto out;
3802                         }
3803                 } else {
3804                         ret = ocfs2_merge_rec_right(path, handle,
3805                                                     et, split_rec,
3806                                                     split_index);
3807                         if (ret) {
3808                                 mlog_errno(ret);
3809                                 goto out;
3810                         }
3811                 }
3812 
3813                 if (ctxt->c_split_covers_rec) {
3814                         /* extend credit for ocfs2_remove_rightmost_path */
3815                         ret = ocfs2_extend_rotate_transaction(handle, 0,
3816                                         handle->h_buffer_credits,
3817                                         path);
3818                         if (ret) {
3819                                 mlog_errno(ret);
3820                                 ret = 0;
3821                                 goto out;
3822                         }
3823 
3824                         /*
3825                          * The merge may have left an empty extent in
3826                          * our leaf. Try to rotate it away.
3827                          */
3828                         ret = ocfs2_rotate_tree_left(handle, et, path,
3829                                                      dealloc);
3830                         if (ret)
3831                                 mlog_errno(ret);
3832                         ret = 0;
3833                 }
3834         }
3835 
3836 out:
3837         return ret;
3838 }
3839 
3840 static void ocfs2_subtract_from_rec(struct super_block *sb,
3841                                     enum ocfs2_split_type split,
3842                                     struct ocfs2_extent_rec *rec,
3843                                     struct ocfs2_extent_rec *split_rec)
3844 {
3845         u64 len_blocks;
3846 
3847         len_blocks = ocfs2_clusters_to_blocks(sb,
3848                                 le16_to_cpu(split_rec->e_leaf_clusters));
3849 
3850         if (split == SPLIT_LEFT) {
3851                 /*
3852                  * Region is on the left edge of the existing
3853                  * record.
3854                  */
3855                 le32_add_cpu(&rec->e_cpos,
3856                              le16_to_cpu(split_rec->e_leaf_clusters));
3857                 le64_add_cpu(&rec->e_blkno, len_blocks);
3858                 le16_add_cpu(&rec->e_leaf_clusters,
3859                              -le16_to_cpu(split_rec->e_leaf_clusters));
3860         } else {
3861                 /*
3862                  * Region is on the right edge of the existing
3863                  * record.
3864                  */
3865                 le16_add_cpu(&rec->e_leaf_clusters,
3866                              -le16_to_cpu(split_rec->e_leaf_clusters));
3867         }
3868 }
3869 
3870 /*
3871  * Do the final bits of extent record insertion at the target leaf
3872  * list. If this leaf is part of an allocation tree, it is assumed
3873  * that the tree above has been prepared.
3874  */
3875 static void ocfs2_insert_at_leaf(struct ocfs2_extent_tree *et,
3876                                  struct ocfs2_extent_rec *insert_rec,
3877                                  struct ocfs2_extent_list *el,
3878                                  struct ocfs2_insert_type *insert)
3879 {
3880         int i = insert->ins_contig_index;
3881         unsigned int range;
3882         struct ocfs2_extent_rec *rec;
3883 
3884         BUG_ON(le16_to_cpu(el->l_tree_depth) != 0);
3885 
3886         if (insert->ins_split != SPLIT_NONE) {
3887                 i = ocfs2_search_extent_list(el, le32_to_cpu(insert_rec->e_cpos));
3888                 BUG_ON(i == -1);
3889                 rec = &el->l_recs[i];
3890                 ocfs2_subtract_from_rec(ocfs2_metadata_cache_get_super(et->et_ci),
3891                                         insert->ins_split, rec,
3892                                         insert_rec);
3893                 goto rotate;
3894         }
3895 
3896         /*
3897          * Contiguous insert - either left or right.
3898          */
3899         if (insert->ins_contig != CONTIG_NONE) {
3900                 rec = &el->l_recs[i];
3901                 if (insert->ins_contig == CONTIG_LEFT) {
3902                         rec->e_blkno = insert_rec->e_blkno;
3903                         rec->e_cpos = insert_rec->e_cpos;
3904                 }
3905                 le16_add_cpu(&rec->e_leaf_clusters,
3906                              le16_to_cpu(insert_rec->e_leaf_clusters));
3907                 return;
3908         }
3909 
3910         /*
3911          * Handle insert into an empty leaf.
3912          */
3913         if (le16_to_cpu(el->l_next_free_rec) == 0 ||
3914             ((le16_to_cpu(el->l_next_free_rec) == 1) &&
3915              ocfs2_is_empty_extent(&el->l_recs[0]))) {
3916                 el->l_recs[0] = *insert_rec;
3917                 el->l_next_free_rec = cpu_to_le16(1);
3918                 return;
3919         }
3920 
3921         /*
3922          * Appending insert.
3923          */
3924         if (insert->ins_appending == APPEND_TAIL) {
3925                 i = le16_to_cpu(el->l_next_free_rec) - 1;
3926                 rec = &el->l_recs[i];
3927                 range = le32_to_cpu(rec->e_cpos)
3928                         + le16_to_cpu(rec->e_leaf_clusters);
3929                 BUG_ON(le32_to_cpu(insert_rec->e_cpos) < range);
3930 
3931                 mlog_bug_on_msg(le16_to_cpu(el->l_next_free_rec) >=
3932                                 le16_to_cpu(el->l_count),
3933                                 "owner %llu, depth %u, count %u, next free %u, "
3934                                 "rec.cpos %u, rec.clusters %u, "
3935                                 "insert.cpos %u, insert.clusters %u\n",
3936                                 ocfs2_metadata_cache_owner(et->et_ci),
3937                                 le16_to_cpu(el->l_tree_depth),
3938                                 le16_to_cpu(el->l_count),
3939                                 le16_to_cpu(el->l_next_free_rec),
3940                                 le32_to_cpu(el->l_recs[i].e_cpos),
3941                                 le16_to_cpu(el->l_recs[i].e_leaf_clusters),
3942                                 le32_to_cpu(insert_rec->e_cpos),
3943                                 le16_to_cpu(insert_rec->e_leaf_clusters));
3944                 i++;
3945                 el->l_recs[i] = *insert_rec;
3946                 le16_add_cpu(&el->l_next_free_rec, 1);
3947                 return;
3948         }
3949 
3950 rotate:
3951         /*
3952          * Ok, we have to rotate.
3953          *
3954          * At this point, it is safe to assume that inserting into an
3955          * empty leaf and appending to a leaf have both been handled
3956          * above.
3957          *
3958          * This leaf needs to have space, either by the empty 1st
3959          * extent record, or by virtue of an l_next_rec < l_count.
3960          */
3961         ocfs2_rotate_leaf(el, insert_rec);
3962 }
3963 
3964 static void ocfs2_adjust_rightmost_records(handle_t *handle,
3965                                            struct ocfs2_extent_tree *et,
3966                                            struct ocfs2_path *path,
3967                                            struct ocfs2_extent_rec *insert_rec)
3968 {
3969         int i, next_free;
3970         struct buffer_head *bh;
3971         struct ocfs2_extent_list *el;
3972         struct ocfs2_extent_rec *rec;
3973 
3974         /*
3975          * Update everything except the leaf block.
3976          */
3977         for (i = 0; i < path->p_tree_depth; i++) {
3978                 bh = path->p_node[i].bh;
3979                 el = path->p_node[i].el;
3980 
3981                 next_free = le16_to_cpu(el->l_next_free_rec);
3982                 if (next_free == 0) {
3983                         ocfs2_error(ocfs2_metadata_cache_get_super(et->et_ci),
3984                                     "Owner %llu has a bad extent list\n",
3985                                     (unsigned long long)ocfs2_metadata_cache_owner(et->et_ci));
3986                         return;
3987                 }
3988 
3989                 rec = &el->l_recs[next_free - 1];
3990 
3991                 rec->e_int_clusters = insert_rec->e_cpos;
3992                 le32_add_cpu(&rec->e_int_clusters,
3993                              le16_to_cpu(insert_rec->e_leaf_clusters));
3994                 le32_add_cpu(&rec->e_int_clusters,
3995                              -le32_to_cpu(rec->e_cpos));
3996 
3997                 ocfs2_journal_dirty(handle, bh);
3998         }
3999 }
4000 
4001 static int ocfs2_append_rec_to_path(handle_t *handle,
4002                                     struct ocfs2_extent_tree *et,
4003                                     struct ocfs2_extent_rec *insert_rec,
4004                                     struct ocfs2_path *right_path,
4005                                     struct ocfs2_path **ret_left_path)
4006 {
4007         int ret, next_free;
4008         struct ocfs2_extent_list *el;
4009         struct ocfs2_path *left_path = NULL;
4010 
4011         *ret_left_path = NULL;
4012 
4013         /*
4014          * This shouldn't happen for non-trees. The extent rec cluster
4015          * count manipulation below only works for interior nodes.
4016          */
4017         BUG_ON(right_path->p_tree_depth == 0);
4018 
4019         /*
4020          * If our appending insert is at the leftmost edge of a leaf,
4021          * then we might need to update the rightmost records of the
4022          * neighboring path.
4023          */
4024         el = path_leaf_el(right_path);
4025         next_free = le16_to_cpu(el->l_next_free_rec);
4026         if (next_free == 0 ||
4027             (next_free == 1 && ocfs2_is_empty_extent(&el->l_recs[0]))) {
4028                 u32 left_cpos;
4029 
4030                 ret = ocfs2_find_cpos_for_left_leaf(ocfs2_metadata_cache_get_super(et->et_ci),
4031                                                     right_path, &left_cpos);
4032                 if (ret) {
4033                         mlog_errno(ret);
4034                         goto out;
4035                 }
4036 
4037                 trace_ocfs2_append_rec_to_path(
4038                         (unsigned long long)
4039                         ocfs2_metadata_cache_owner(et->et_ci),
4040                         le32_to_cpu(insert_rec->e_cpos),
4041                         left_cpos);
4042 
4043                 /*
4044                  * No need to worry if the append is already in the
4045                  * leftmost leaf.
4046                  */
4047                 if (left_cpos) {
4048                         left_path = ocfs2_new_path_from_path(right_path);
4049                         if (!left_path) {
4050                                 ret = -ENOMEM;
4051                                 mlog_errno(ret);
4052                                 goto out;
4053                         }
4054 
4055                         ret = ocfs2_find_path(et->et_ci, left_path,
4056                                               left_cpos);
4057                         if (ret) {
4058                                 mlog_errno(ret);
4059                                 goto out;
4060                         }
4061 
4062                         /*
4063                          * ocfs2_insert_path() will pass the left_path to the
4064                          * journal for us.
4065                          */
4066                 }
4067         }
4068 
4069         ret = ocfs2_journal_access_path(et->et_ci, handle, right_path);
4070         if (ret) {
4071                 mlog_errno(ret);
4072                 goto out;
4073         }
4074 
4075         ocfs2_adjust_rightmost_records(handle, et, right_path, insert_rec);
4076 
4077         *ret_left_path = left_path;
4078         ret = 0;
4079 out:
4080         if (ret != 0)
4081                 ocfs2_free_path(left_path);
4082 
4083         return ret;
4084 }
4085 
4086 static void ocfs2_split_record(struct ocfs2_extent_tree *et,
4087                                struct ocfs2_path *left_path,
4088                                struct ocfs2_path *right_path,
4089                                struct ocfs2_extent_rec *split_rec,
4090                                enum ocfs2_split_type split)
4091 {
4092         int index;
4093         u32 cpos = le32_to_cpu(split_rec->e_cpos);
4094         struct ocfs2_extent_list *left_el = NULL, *right_el, *insert_el, *el;
4095         struct ocfs2_extent_rec *rec, *tmprec;
4096 
4097         right_el = path_leaf_el(right_path);
4098         if (left_path)
4099                 left_el = path_leaf_el(left_path);
4100 
4101         el = right_el;
4102         insert_el = right_el;
4103         index = ocfs2_search_extent_list(el, cpos);
4104         if (index != -1) {
4105                 if (index == 0 && left_path) {
4106                         BUG_ON(ocfs2_is_empty_extent(&el->l_recs[0]));
4107 
4108                         /*
4109                          * This typically means that the record
4110                          * started in the left path but moved to the
4111                          * right as a result of rotation. We either
4112                          * move the existing record to the left, or we
4113                          * do the later insert there.
4114                          *
4115                          * In this case, the left path should always
4116                          * exist as the rotate code will have passed
4117                          * it back for a post-insert update.
4118                          */
4119 
4120                         if (split == SPLIT_LEFT) {
4121                                 /*
4122                                  * It's a left split. Since we know
4123                                  * that the rotate code gave us an
4124                                  * empty extent in the left path, we
4125                                  * can just do the insert there.
4126                                  */
4127                                 insert_el = left_el;
4128                         } else {
4129                                 /*
4130                                  * Right split - we have to move the
4131                                  * existing record over to the left
4132                                  * leaf. The insert will be into the
4133                                  * newly created empty extent in the
4134                                  * right leaf.
4135                                  */
4136                                 tmprec = &right_el->l_recs[index];
4137                                 ocfs2_rotate_leaf(left_el, tmprec);
4138                                 el = left_el;
4139 
4140                                 memset(tmprec, 0, sizeof(*tmprec));
4141                                 index = ocfs2_search_extent_list(left_el, cpos);
4142                                 BUG_ON(index == -1);
4143                         }
4144                 }
4145         } else {
4146                 BUG_ON(!left_path);
4147                 BUG_ON(!ocfs2_is_empty_extent(&left_el->l_recs[0]));
4148                 /*
4149                  * Left path is easy - we can just allow the insert to
4150                  * happen.
4151                  */
4152                 el = left_el;
4153                 insert_el = left_el;
4154                 index = ocfs2_search_extent_list(el, cpos);
4155                 BUG_ON(index == -1);
4156         }
4157 
4158         rec = &el->l_recs[index];
4159         ocfs2_subtract_from_rec(ocfs2_metadata_cache_get_super(et->et_ci),
4160                                 split, rec, split_rec);
4161         ocfs2_rotate_leaf(insert_el, split_rec);
4162 }
4163 
4164 /*
4165  * This function only does inserts on an allocation b-tree. For tree
4166  * depth = 0, ocfs2_insert_at_leaf() is called directly.
4167  *
4168  * right_path is the path we want to do the actual insert
4169  * in. left_path should only be passed in if we need to update that
4170  * portion of the tree after an edge insert.
4171  */
4172 static int ocfs2_insert_path(handle_t *handle,
4173                              struct ocfs2_extent_tree *et,
4174                              struct ocfs2_path *left_path,
4175                              struct ocfs2_path *right_path,
4176                              struct ocfs2_extent_rec *insert_rec,
4177                              struct ocfs2_insert_type *insert)
4178 {
4179         int ret, subtree_index;
4180         struct buffer_head *leaf_bh = path_leaf_bh(right_path);
4181 
4182         if (left_path) {
4183                 /*
4184                  * There's a chance that left_path got passed back to
4185                  * us without being accounted for in the
4186                  * journal. Extend our transaction here to be sure we
4187                  * can change those blocks.
4188                  */
4189                 ret = ocfs2_extend_trans(handle, left_path->p_tree_depth);
4190                 if (ret < 0) {
4191                         mlog_errno(ret);
4192                         goto out;
4193                 }
4194 
4195                 ret = ocfs2_journal_access_path(et->et_ci, handle, left_path);
4196                 if (ret < 0) {
4197                         mlog_errno(ret);
4198                         goto out;
4199                 }
4200         }
4201 
4202         /*
4203          * Pass both paths to the journal. The majority of inserts
4204          * will be touching all components anyway.
4205          */
4206         ret = ocfs2_journal_access_path(et->et_ci, handle, right_path);
4207         if (ret < 0) {
4208                 mlog_errno(ret);
4209                 goto out;
4210         }
4211 
4212         if (insert->ins_split != SPLIT_NONE) {
4213                 /*
4214                  * We could call ocfs2_insert_at_leaf() for some types
4215                  * of splits, but it's easier to just let one separate
4216                  * function sort it all out.
4217                  */
4218                 ocfs2_split_record(et, left_path, right_path,
4219                                    insert_rec, insert->ins_split);
4220 
4221                 /*
4222                  * Split might have modified either leaf and we don't
4223                  * have a guarantee that the later edge insert will
4224                  * dirty this for us.
4225                  */
4226                 if (left_path)
4227                         ocfs2_journal_dirty(handle,
4228                                             path_leaf_bh(left_path));
4229         } else
4230                 ocfs2_insert_at_leaf(et, insert_rec, path_leaf_el(right_path),
4231                                      insert);
4232 
4233         ocfs2_journal_dirty(handle, leaf_bh);
4234 
4235         if (left_path) {
4236                 /*
4237                  * The rotate code has indicated that we need to fix
4238                  * up portions of the tree after the insert.
4239                  *
4240                  * XXX: Should we extend the transaction here?
4241                  */
4242                 subtree_index = ocfs2_find_subtree_root(et, left_path,
4243                                                         right_path);
4244                 ocfs2_complete_edge_insert(handle, left_path, right_path,
4245                                            subtree_index);
4246         }
4247 
4248         ret = 0;
4249 out:
4250         return ret;
4251 }
4252 
4253 static int ocfs2_do_insert_extent(handle_t *handle,
4254                                   struct ocfs2_extent_tree *et,
4255                                   struct ocfs2_extent_rec *insert_rec,
4256                                   struct ocfs2_insert_type *type)
4257 {
4258         int ret, rotate = 0;
4259         u32 cpos;
4260         struct ocfs2_path *right_path = NULL;
4261         struct ocfs2_path *left_path = NULL;
4262         struct ocfs2_extent_list *el;
4263 
4264         el = et->et_root_el;
4265 
4266         ret = ocfs2_et_root_journal_access(handle, et,
4267                                            OCFS2_JOURNAL_ACCESS_WRITE);
4268         if (ret) {
4269                 mlog_errno(ret);
4270                 goto out;
4271         }
4272 
4273         if (le16_to_cpu(el->l_tree_depth) == 0) {
4274                 ocfs2_insert_at_leaf(et, insert_rec, el, type);
4275                 goto out_update_clusters;
4276         }
4277 
4278         right_path = ocfs2_new_path_from_et(et);
4279         if (!right_path) {
4280                 ret = -ENOMEM;
4281                 mlog_errno(ret);
4282                 goto out;
4283         }
4284 
4285         /*
4286          * Determine the path to start with. Rotations need the
4287          * rightmost path, everything else can go directly to the
4288          * target leaf.
4289          */
4290         cpos = le32_to_cpu(insert_rec->e_cpos);
4291         if (type->ins_appending == APPEND_NONE &&
4292             type->ins_contig == CONTIG_NONE) {
4293                 rotate = 1;
4294                 cpos = UINT_MAX;
4295         }
4296 
4297         ret = ocfs2_find_path(et->et_ci, right_path, cpos);
4298         if (ret) {
4299                 mlog_errno(ret);
4300                 goto out;
4301         }
4302 
4303         /*
4304          * Rotations and appends need special treatment - they modify
4305          * parts of the tree's above them.
4306          *
4307          * Both might pass back a path immediate to the left of the
4308          * one being inserted to. This will be cause
4309          * ocfs2_insert_path() to modify the rightmost records of
4310          * left_path to account for an edge insert.
4311          *
4312          * XXX: When modifying this code, keep in mind that an insert
4313          * can wind up skipping both of these two special cases...
4314          */
4315         if (rotate) {
4316                 ret = ocfs2_rotate_tree_right(handle, et, type->ins_split,
4317                                               le32_to_cpu(insert_rec->e_cpos),
4318                                               right_path, &left_path);
4319                 if (ret) {
4320                         mlog_errno(ret);
4321                         goto out;
4322                 }
4323 
4324                 /*
4325                  * ocfs2_rotate_tree_right() might have extended the
4326                  * transaction without re-journaling our tree root.
4327                  */
4328                 ret = ocfs2_et_root_journal_access(handle, et,
4329                                                    OCFS2_JOURNAL_ACCESS_WRITE);
4330                 if (ret) {
4331                         mlog_errno(ret);
4332                         goto out;
4333                 }
4334         } else if (type->ins_appending == APPEND_TAIL
4335                    && type->ins_contig != CONTIG_LEFT) {
4336                 ret = ocfs2_append_rec_to_path(handle, et, insert_rec,
4337                                                right_path, &left_path);
4338                 if (ret) {
4339                         mlog_errno(ret);
4340                         goto out;
4341                 }
4342         }
4343 
4344         ret = ocfs2_insert_path(handle, et, left_path, right_path,
4345                                 insert_rec, type);
4346         if (ret) {
4347                 mlog_errno(ret);
4348                 goto out;
4349         }
4350 
4351 out_update_clusters:
4352         if (type->ins_split == SPLIT_NONE)
4353                 ocfs2_et_update_clusters(et,
4354                                          le16_to_cpu(insert_rec->e_leaf_clusters));
4355 
4356         ocfs2_journal_dirty(handle, et->et_root_bh);
4357 
4358 out:
4359         ocfs2_free_path(left_path);
4360         ocfs2_free_path(right_path);
4361 
4362         return ret;
4363 }
4364 
4365 static int ocfs2_figure_merge_contig_type(struct ocfs2_extent_tree *et,
4366                                struct ocfs2_path *path,
4367                                struct ocfs2_extent_list *el, int index,
4368                                struct ocfs2_extent_rec *split_rec,
4369                                struct ocfs2_merge_ctxt *ctxt)
4370 {
4371         int status = 0;
4372         enum ocfs2_contig_type ret = CONTIG_NONE;
4373         u32 left_cpos, right_cpos;
4374         struct ocfs2_extent_rec *rec = NULL;
4375         struct ocfs2_extent_list *new_el;
4376         struct ocfs2_path *left_path = NULL, *right_path = NULL;
4377         struct buffer_head *bh;
4378         struct ocfs2_extent_block *eb;
4379         struct super_block *sb = ocfs2_metadata_cache_get_super(et->et_ci);
4380 
4381         if (index > 0) {
4382                 rec = &el->l_recs[index - 1];
4383         } else if (path->p_tree_depth > 0) {
4384                 status = ocfs2_find_cpos_for_left_leaf(sb, path, &left_cpos);
4385                 if (status)
4386                         goto exit;
4387 
4388                 if (left_cpos != 0) {
4389                         left_path = ocfs2_new_path_from_path(path);
4390                         if (!left_path) {
4391                                 status = -ENOMEM;
4392                                 mlog_errno(status);
4393                                 goto exit;
4394                         }
4395 
4396                         status = ocfs2_find_path(et->et_ci, left_path,
4397                                                  left_cpos);
4398                         if (status)
4399                                 goto free_left_path;
4400 
4401                         new_el = path_leaf_el(left_path);
4402 
4403                         if (le16_to_cpu(new_el->l_next_free_rec) !=
4404                             le16_to_cpu(new_el->l_count)) {
4405                                 bh = path_leaf_bh(left_path);
4406                                 eb = (struct ocfs2_extent_block *)bh->b_data;
4407                                 status = ocfs2_error(sb,
4408                                                 "Extent block #%llu has an invalid l_next_free_rec of %d.  It should have matched the l_count of %d\n",
4409                                                 (unsigned long long)le64_to_cpu(eb->h_blkno),
4410                                                 le16_to_cpu(new_el->l_next_free_rec),
4411                                                 le16_to_cpu(new_el->l_count));
4412                                 goto free_left_path;
4413                         }
4414                         rec = &new_el->l_recs[
4415                                 le16_to_cpu(new_el->l_next_free_rec) - 1];
4416                 }
4417         }
4418 
4419         /*
4420          * We're careful to check for an empty extent record here -
4421          * the merge code will know what to do if it sees one.
4422          */
4423         if (rec) {
4424                 if (index == 1 && ocfs2_is_empty_extent(rec)) {
4425                         if (split_rec->e_cpos == el->l_recs[index].e_cpos)
4426                                 ret = CONTIG_RIGHT;
4427                 } else {
4428                         ret = ocfs2_et_extent_contig(et, rec, split_rec);
4429                 }
4430         }
4431 
4432         rec = NULL;
4433         if (index < (le16_to_cpu(el->l_next_free_rec) - 1))
4434                 rec = &el->l_recs[index + 1];
4435         else if (le16_to_cpu(el->l_next_free_rec) == le16_to_cpu(el->l_count) &&
4436                  path->p_tree_depth > 0) {
4437                 status = ocfs2_find_cpos_for_right_leaf(sb, path, &right_cpos);
4438                 if (status)
4439                         goto free_left_path;
4440 
4441                 if (right_cpos == 0)
4442                         goto free_left_path;
4443 
4444                 right_path = ocfs2_new_path_from_path(path);
4445                 if (!right_path) {
4446                         status = -ENOMEM;
4447                         mlog_errno(status);
4448                         goto free_left_path;
4449                 }
4450 
4451                 status = ocfs2_find_path(et->et_ci, right_path, right_cpos);
4452                 if (status)
4453                         goto free_right_path;
4454 
4455                 new_el = path_leaf_el(right_path);
4456                 rec = &new_el->l_recs[0];
4457                 if (ocfs2_is_empty_extent(rec)) {
4458                         if (le16_to_cpu(new_el->l_next_free_rec) <= 1) {
4459                                 bh = path_leaf_bh(right_path);
4460                                 eb = (struct ocfs2_extent_block *)bh->b_data;
4461                                 status = ocfs2_error(sb,
4462                                                 "Extent block #%llu has an invalid l_next_free_rec of %d\n",
4463                                                 (unsigned long long)le64_to_cpu(eb->h_blkno),
4464                                                 le16_to_cpu(new_el->l_next_free_rec));
4465                                 goto free_right_path;
4466                         }
4467                         rec = &new_el->l_recs[1];
4468                 }
4469         }
4470 
4471         if (rec) {
4472                 enum ocfs2_contig_type contig_type;
4473 
4474                 contig_type = ocfs2_et_extent_contig(et, rec, split_rec);
4475 
4476                 if (contig_type == CONTIG_LEFT && ret == CONTIG_RIGHT)
4477                         ret = CONTIG_LEFTRIGHT;
4478                 else if (ret == CONTIG_NONE)
4479                         ret = contig_type;
4480         }
4481 
4482 free_right_path:
4483         ocfs2_free_path(right_path);
4484 free_left_path:
4485         ocfs2_free_path(left_path);
4486 exit:
4487         if (status == 0)
4488                 ctxt->c_contig_type = ret;
4489 
4490         return status;
4491 }
4492 
4493 static void ocfs2_figure_contig_type(struct ocfs2_extent_tree *et,
4494                                      struct ocfs2_insert_type *insert,
4495                                      struct ocfs2_extent_list *el,
4496                                      struct ocfs2_extent_rec *insert_rec)
4497 {
4498         int i;
4499         enum ocfs2_contig_type contig_type = CONTIG_NONE;
4500 
4501         BUG_ON(le16_to_cpu(el->l_tree_depth) != 0);
4502 
4503         for(i = 0; i < le16_to_cpu(el->l_next_free_rec); i++) {
4504                 contig_type = ocfs2_et_extent_contig(et, &el->l_recs[i],
4505                                                      insert_rec);
4506                 if (contig_type != CONTIG_NONE) {
4507                         insert->ins_contig_index = i;
4508                         break;
4509                 }
4510         }
4511         insert->ins_contig = contig_type;
4512 
4513         if (insert->ins_contig != CONTIG_NONE) {
4514                 struct ocfs2_extent_rec *rec =
4515                                 &el->l_recs[insert->ins_contig_index];
4516                 unsigned int len = le16_to_cpu(rec->e_leaf_clusters) +
4517                                    le16_to_cpu(insert_rec->e_leaf_clusters);
4518 
4519                 /*
4520                  * Caller might want us to limit the size of extents, don't
4521                  * calculate contiguousness if we might exceed that limit.
4522                  */
4523                 if (et->et_max_leaf_clusters &&
4524                     (len > et->et_max_leaf_clusters))
4525                         insert->ins_contig = CONTIG_NONE;
4526         }
4527 }
4528 
4529 /*
4530  * This should only be called against the righmost leaf extent list.
4531  *
4532  * ocfs2_figure_appending_type() will figure out whether we'll have to
4533  * insert at the tail of the rightmost leaf.
4534  *
4535  * This should also work against the root extent list for tree's with 0
4536  * depth. If we consider the root extent list to be the rightmost leaf node
4537  * then the logic here makes sense.
4538  */
4539 static void ocfs2_figure_appending_type(struct ocfs2_insert_type *insert,
4540                                         struct ocfs2_extent_list *el,
4541                                         struct ocfs2_extent_rec *insert_rec)
4542 {
4543         int i;
4544         u32 cpos = le32_to_cpu(insert_rec->e_cpos);
4545         struct ocfs2_extent_rec *rec;
4546 
4547         insert->ins_appending = APPEND_NONE;
4548 
4549         BUG_ON(le16_to_cpu(el->l_tree_depth) != 0);
4550 
4551         if (!el->l_next_free_rec)
4552                 goto set_tail_append;
4553 
4554         if (ocfs2_is_empty_extent(&el->l_recs[0])) {
4555                 /* Were all records empty? */
4556                 if (le16_to_cpu(el->l_next_free_rec) == 1)
4557                         goto set_tail_append;
4558         }
4559 
4560         i = le16_to_cpu(el->l_next_free_rec) - 1;
4561         rec = &el->l_recs[i];
4562 
4563         if (cpos >=
4564             (le32_to_cpu(rec->e_cpos) + le16_to_cpu(rec->e_leaf_clusters)))
4565                 goto set_tail_append;
4566 
4567         return;
4568 
4569 set_tail_append:
4570         insert->ins_appending = APPEND_TAIL;
4571 }
4572 
4573 /*
4574  * Helper function called at the beginning of an insert.
4575  *
4576  * This computes a few things that are commonly used in the process of
4577  * inserting into the btree:
4578  *   - Whether the new extent is contiguous with an existing one.
4579  *   - The current tree depth.
4580  *   - Whether the insert is an appending one.
4581  *   - The total # of free records in the tree.
4582  *
4583  * All of the information is stored on the ocfs2_insert_type
4584  * structure.
4585  */
4586 static int ocfs2_figure_insert_type(struct ocfs2_extent_tree *et,
4587                                     struct buffer_head **last_eb_bh,
4588                                     struct ocfs2_extent_rec *insert_rec,
4589                                     int *free_records,
4590                                     struct ocfs2_insert_type *insert)
4591 {
4592         int ret;
4593         struct ocfs2_extent_block *eb;
4594         struct ocfs2_extent_list *el;
4595         struct ocfs2_path *path = NULL;
4596         struct buffer_head *bh = NULL;
4597 
4598         insert->ins_split = SPLIT_NONE;
4599 
4600         el = et->et_root_el;
4601         insert->ins_tree_depth = le16_to_cpu(el->l_tree_depth);
4602 
4603         if (el->l_tree_depth) {
4604                 /*
4605                  * If we have tree depth, we read in the
4606                  * rightmost extent block ahead of time as
4607                  * ocfs2_figure_insert_type() and ocfs2_add_branch()
4608                  * may want it later.
4609                  */
4610                 ret = ocfs2_read_extent_block(et->et_ci,
4611                                               ocfs2_et_get_last_eb_blk(et),
4612                                               &bh);
4613                 if (ret) {
4614                         mlog_errno(ret);
4615                         goto out;
4616                 }
4617                 eb = (struct ocfs2_extent_block *) bh->b_data;
4618                 el = &eb->h_list;
4619         }
4620 
4621         /*
4622          * Unless we have a contiguous insert, we'll need to know if
4623          * there is room left in our allocation tree for another
4624          * extent record.
4625          *
4626          * XXX: This test is simplistic, we can search for empty
4627          * extent records too.
4628          */
4629         *free_records = le16_to_cpu(el->l_count) -
4630                 le16_to_cpu(el->l_next_free_rec);
4631 
4632         if (!insert->ins_tree_depth) {
4633                 ocfs2_figure_contig_type(et, insert, el, insert_rec);
4634                 ocfs2_figure_appending_type(insert, el, insert_rec);
4635                 return 0;
4636         }
4637 
4638         path = ocfs2_new_path_from_et(et);
4639         if (!path) {
4640                 ret = -ENOMEM;
4641                 mlog_errno(ret);
4642                 goto out;
4643         }
4644 
4645         /*
4646          * In the case that we're inserting past what the tree
4647          * currently accounts for, ocfs2_find_path() will return for
4648          * us the rightmost tree path. This is accounted for below in
4649          * the appending code.
4650          */
4651         ret = ocfs2_find_path(et->et_ci, path, le32_to_cpu(insert_rec->e_cpos));
4652         if (ret) {
4653                 mlog_errno(ret);
4654                 goto out;
4655         }
4656 
4657         el = path_leaf_el(path);
4658 
4659         /*
4660          * Now that we have the path, there's two things we want to determine:
4661          * 1) Contiguousness (also set contig_index if this is so)
4662          *
4663          * 2) Are we doing an append? We can trivially break this up
4664          *     into two types of appends: simple record append, or a
4665          *     rotate inside the tail leaf.
4666          */
4667         ocfs2_figure_contig_type(et, insert, el, insert_rec);
4668 
4669         /*
4670          * The insert code isn't quite ready to deal with all cases of
4671          * left contiguousness. Specifically, if it's an insert into
4672          * the 1st record in a leaf, it will require the adjustment of
4673          * cluster count on the last record of the path directly to it's
4674          * left. For now, just catch that case and fool the layers
4675          * above us. This works just fine for tree_depth == 0, which
4676          * is why we allow that above.
4677          */
4678         if (insert->ins_contig == CONTIG_LEFT &&
4679             insert->ins_contig_index == 0)
4680                 insert->ins_contig = CONTIG_NONE;
4681 
4682         /*
4683          * Ok, so we can simply compare against last_eb to figure out
4684          * whether the path doesn't exist. This will only happen in
4685          * the case that we're doing a tail append, so maybe we can
4686          * take advantage of that information somehow.
4687          */
4688         if (ocfs2_et_get_last_eb_blk(et) ==
4689             path_leaf_bh(path)->b_blocknr) {
4690                 /*
4691                  * Ok, ocfs2_find_path() returned us the rightmost
4692                  * tree path. This might be an appending insert. There are
4693                  * two cases:
4694                  *    1) We're doing a true append at the tail:
4695                  *      -This might even be off the end of the leaf
4696                  *    2) We're "appending" by rotating in the tail
4697                  */
4698                 ocfs2_figure_appending_type(insert, el, insert_rec);
4699         }
4700 
4701 out:
4702         ocfs2_free_path(path);
4703 
4704         if (ret == 0)
4705                 *last_eb_bh = bh;
4706         else
4707                 brelse(bh);
4708         return ret;
4709 }
4710 
4711 /*
4712  * Insert an extent into a btree.
4713  *
4714  * The caller needs to update the owning btree's cluster count.
4715  */
4716 int ocfs2_insert_extent(handle_t *handle,
4717                         struct ocfs2_extent_tree *et,
4718                         u32 cpos,
4719                         u64 start_blk,
4720                         u32 new_clusters,
4721                         u8 flags,
4722                         struct ocfs2_alloc_context *meta_ac)
4723 {
4724         int status;
4725         int uninitialized_var(free_records);
4726         struct buffer_head *last_eb_bh = NULL;
4727         struct ocfs2_insert_type insert = {0, };
4728         struct ocfs2_extent_rec rec;
4729 
4730         trace_ocfs2_insert_extent_start(
4731                 (unsigned long long)ocfs2_metadata_cache_owner(et->et_ci),
4732                 cpos, new_clusters);
4733 
4734         memset(&rec, 0, sizeof(rec));
4735         rec.e_cpos = cpu_to_le32(cpos);
4736         rec.e_blkno = cpu_to_le64(start_blk);
4737         rec.e_leaf_clusters = cpu_to_le16(new_clusters);
4738         rec.e_flags = flags;
4739         status = ocfs2_et_insert_check(et, &rec);
4740         if (status) {
4741                 mlog_errno(status);
4742                 goto bail;
4743         }
4744 
4745         status = ocfs2_figure_insert_type(et, &last_eb_bh, &rec,
4746                                           &free_records, &insert);
4747         if (status < 0) {
4748                 mlog_errno(status);
4749                 goto bail;
4750         }
4751 
4752         trace_ocfs2_insert_extent(insert.ins_appending, insert.ins_contig,
4753                                   insert.ins_contig_index, free_records,
4754                                   insert.ins_tree_depth);
4755 
4756         if (insert.ins_contig == CONTIG_NONE && free_records == 0) {
4757                 status = ocfs2_grow_tree(handle, et,
4758                                          &insert.ins_tree_depth, &last_eb_bh,
4759                                          meta_ac);
4760                 if (status) {
4761                         mlog_errno(status);
4762                         goto bail;
4763                 }
4764         }
4765 
4766         /* Finally, we can add clusters. This might rotate the tree for us. */
4767         status = ocfs2_do_insert_extent(handle, et, &rec, &insert);
4768         if (status < 0)
4769                 mlog_errno(status);
4770         else
4771                 ocfs2_et_extent_map_insert(et, &rec);
4772 
4773 bail:
4774         brelse(last_eb_bh);
4775 
4776         return status;
4777 }
4778 
4779 /*
4780  * Allcate and add clusters into the extent b-tree.
4781  * The new clusters(clusters_to_add) will be inserted at logical_offset.
4782  * The extent b-tree's root is specified by et, and
4783  * it is not limited to the file storage. Any extent tree can use this
4784  * function if it implements the proper ocfs2_extent_tree.
4785  */
4786 int ocfs2_add_clusters_in_btree(handle_t *handle,
4787                                 struct ocfs2_extent_tree *et,
4788                                 u32 *logical_offset,
4789                                 u32 clusters_to_add,
4790                                 int mark_unwritten,
4791                                 struct ocfs2_alloc_context *data_ac,
4792                                 struct ocfs2_alloc_context *meta_ac,
4793                                 enum ocfs2_alloc_restarted *reason_ret)
4794 {
4795         int status = 0, err = 0;
4796         int need_free = 0;
4797         int free_extents;
4798         enum ocfs2_alloc_restarted reason = RESTART_NONE;
4799         u32 bit_off, num_bits;
4800         u64 block;
4801         u8 flags = 0;
4802         struct ocfs2_super *osb =
4803                 OCFS2_SB(ocfs2_metadata_cache_get_super(et->et_ci));
4804 
4805         BUG_ON(!clusters_to_add);
4806 
4807         if (mark_unwritten)
4808                 flags = OCFS2_EXT_UNWRITTEN;
4809 
4810         free_extents = ocfs2_num_free_extents(et);
4811         if (free_extents < 0) {
4812                 status = free_extents;
4813                 mlog_errno(status);
4814                 goto leave;
4815         }
4816 
4817         /* there are two cases which could cause us to EAGAIN in the
4818          * we-need-more-metadata case:
4819          * 1) we haven't reserved *any*
4820          * 2) we are so fragmented, we've needed to add metadata too
4821          *    many times. */
4822         if (!free_extents && !meta_ac) {
4823                 err = -1;
4824                 status = -EAGAIN;
4825                 reason = RESTART_META;
4826                 goto leave;
4827         } else if ((!free_extents)
4828                    && (ocfs2_alloc_context_bits_left(meta_ac)
4829                        < ocfs2_extend_meta_needed(et->et_root_el))) {
4830                 err = -2;
4831                 status = -EAGAIN;
4832                 reason = RESTART_META;
4833                 goto leave;
4834         }
4835 
4836         status = __ocfs2_claim_clusters(handle, data_ac, 1,
4837                                         clusters_to_add, &bit_off, &num_bits);
4838         if (status < 0) {
4839                 if (status != -ENOSPC)
4840                         mlog_errno(status);
4841                 goto leave;
4842         }
4843 
4844         BUG_ON(num_bits > clusters_to_add);
4845 
4846         /* reserve our write early -- insert_extent may update the tree root */
4847         status = ocfs2_et_root_journal_access(handle, et,
4848                                               OCFS2_JOURNAL_ACCESS_WRITE);
4849         if (status < 0) {
4850                 mlog_errno(status);
4851                 need_free = 1;
4852                 goto bail;
4853         }
4854 
4855         block = ocfs2_clusters_to_blocks(osb->sb, bit_off);
4856         trace_ocfs2_add_clusters_in_btree(
4857              (unsigned long long)ocfs2_metadata_cache_owner(et->et_ci),
4858              bit_off, num_bits);
4859         status = ocfs2_insert_extent(handle, et, *logical_offset, block,
4860                                      num_bits, flags, meta_ac);
4861         if (status < 0) {
4862                 mlog_errno(status);
4863                 need_free = 1;
4864                 goto bail;
4865         }
4866 
4867         ocfs2_journal_dirty(handle, et->et_root_bh);
4868 
4869         clusters_to_add -= num_bits;
4870         *logical_offset += num_bits;
4871 
4872         if (clusters_to_add) {
4873                 err = clusters_to_add;
4874                 status = -EAGAIN;
4875                 reason = RESTART_TRANS;
4876         }
4877 
4878 bail:
4879         if (need_free) {
4880                 if (data_ac->ac_which == OCFS2_AC_USE_LOCAL)
4881                         ocfs2_free_local_alloc_bits(osb, handle, data_ac,
4882                                         bit_off, num_bits);
4883                 else
4884                         ocfs2_free_clusters(handle,
4885                                         data_ac->ac_inode,
4886                                         data_ac->ac_bh,
4887                                         ocfs2_clusters_to_blocks(osb->sb, bit_off),
4888                                         num_bits);
4889         }
4890 
4891 leave:
4892         if (reason_ret)
4893                 *reason_ret = reason;
4894         trace_ocfs2_add_clusters_in_btree_ret(status, reason, err);
4895         return status;
4896 }
4897 
4898 static void ocfs2_make_right_split_rec(struct super_block *sb,
4899                                        struct ocfs2_extent_rec *split_rec,
4900                                        u32 cpos,
4901                                        struct ocfs2_extent_rec *rec)
4902 {
4903         u32 rec_cpos = le32_to_cpu(rec->e_cpos);
4904         u32 rec_range = rec_cpos + le16_to_cpu(rec->e_leaf_clusters);
4905 
4906         memset(split_rec, 0, sizeof(struct ocfs2_extent_rec));
4907 
4908         split_rec->e_cpos = cpu_to_le32(cpos);
4909         split_rec->e_leaf_clusters = cpu_to_le16(rec_range - cpos);
4910 
4911         split_rec->e_blkno = rec->e_blkno;
4912         le64_add_cpu(&split_rec->e_blkno,
4913                      ocfs2_clusters_to_blocks(sb, cpos - rec_cpos));
4914 
4915         split_rec->e_flags = rec->e_flags;
4916 }
4917 
4918 static int ocfs2_split_and_insert(handle_t *handle,
4919                                   struct ocfs2_extent_tree *et,
4920                                   struct ocfs2_path *path,
4921                                   struct buffer_head **last_eb_bh,
4922                                   int split_index,
4923                                   struct ocfs2_extent_rec *orig_split_rec,
4924                                   struct ocfs2_alloc_context *meta_ac)
4925 {
4926         int ret = 0, depth;
4927         unsigned int insert_range, rec_range, do_leftright = 0;
4928         struct ocfs2_extent_rec tmprec;
4929         struct ocfs2_extent_list *rightmost_el;
4930         struct ocfs2_extent_rec rec;
4931         struct ocfs2_extent_rec split_rec = *orig_split_rec;
4932         struct ocfs2_insert_type insert;
4933         struct ocfs2_extent_block *eb;
4934 
4935 leftright:
4936         /*
4937          * Store a copy of the record on the stack - it might move
4938          * around as the tree is manipulated below.
4939          */
4940         rec = path_leaf_el(path)->l_recs[split_index];
4941 
4942         rightmost_el = et->et_root_el;
4943 
4944         depth = le16_to_cpu(rightmost_el->l_tree_depth);
4945         if (depth) {
4946                 BUG_ON(!(*last_eb_bh));
4947                 eb = (struct ocfs2_extent_block *) (*last_eb_bh)->b_data;
4948                 rightmost_el = &eb->h_list;
4949         }
4950 
4951         if (le16_to_cpu(rightmost_el->l_next_free_rec) ==
4952             le16_to_cpu(rightmost_el->l_count)) {
4953                 ret = ocfs2_grow_tree(handle, et,
4954                                       &depth, last_eb_bh, meta_ac);
4955                 if (ret) {
4956                         mlog_errno(ret);
4957                         goto out;
4958                 }
4959         }
4960 
4961         memset(&insert, 0, sizeof(struct ocfs2_insert_type));
4962         insert.ins_appending = APPEND_NONE;
4963         insert.ins_contig = CONTIG_NONE;
4964         insert.ins_tree_depth = depth;
4965 
4966         insert_range = le32_to_cpu(split_rec.e_cpos) +
4967                 le16_to_cpu(split_rec.e_leaf_clusters);
4968         rec_range = le32_to_cpu(rec.e_cpos) +
4969                 le16_to_cpu(rec.e_leaf_clusters);
4970 
4971         if (split_rec.e_cpos == rec.e_cpos) {
4972                 insert.ins_split = SPLIT_LEFT;
4973         } else if (insert_range == rec_range) {
4974                 insert.ins_split = SPLIT_RIGHT;
4975         } else {
4976                 /*
4977                  * Left/right split. We fake this as a right split
4978                  * first and then make a second pass as a left split.
4979                  */
4980                 insert.ins_split = SPLIT_RIGHT;
4981 
4982                 ocfs2_make_right_split_rec(ocfs2_metadata_cache_get_super(et->et_ci),
4983                                            &tmprec, insert_range, &rec);
4984 
4985                 split_rec = tmprec;
4986 
4987                 BUG_ON(do_leftright);
4988                 do_leftright = 1;
4989         }
4990 
4991         ret = ocfs2_do_insert_extent(handle, et, &split_rec, &insert);
4992         if (ret) {
4993                 mlog_errno(ret);
4994                 goto out;
4995         }
4996 
4997         if (do_leftright == 1) {
4998                 u32 cpos;
4999                 struct ocfs2_extent_list *el;
5000 
5001                 do_leftright++;
5002                 split_rec = *orig_split_rec;
5003 
5004                 ocfs2_reinit_path(path, 1);
5005 
5006                 cpos = le32_to_cpu(split_rec.e_cpos);
5007                 ret = ocfs2_find_path(et->et_ci, path, cpos);
5008                 if (ret) {
5009                         mlog_errno(ret);
5010                         goto out;
5011                 }
5012 
5013                 el = path_leaf_el(path);
5014                 split_index = ocfs2_search_extent_list(el, cpos);
5015                 if (split_index == -1) {
5016                         ocfs2_error(ocfs2_metadata_cache_get_super(et->et_ci),
5017                                     "Owner %llu has an extent at cpos %u which can no longer be found\n",
5018                                     (unsigned long long)ocfs2_metadata_cache_owner(et->et_ci),
5019                                     cpos);
5020                         ret = -EROFS;
5021                         goto out;
5022                 }
5023                 goto leftright;
5024         }
5025 out:
5026 
5027         return ret;
5028 }
5029 
5030 static int ocfs2_replace_extent_rec(handle_t *handle,
5031                                     struct ocfs2_extent_tree *et,
5032                                     struct ocfs2_path *path,
5033                                     struct ocfs2_extent_list *el,
5034                                     int split_index,
5035                                     struct ocfs2_extent_rec *split_rec)
5036 {
5037         int ret;
5038 
5039         ret = ocfs2_path_bh_journal_access(handle, et->et_ci, path,
5040                                            path_num_items(path) - 1);
5041         if (ret) {
5042                 mlog_errno(ret);
5043                 goto out;
5044         }
5045 
5046         el->l_recs[split_index] = *split_rec;
5047 
5048         ocfs2_journal_dirty(handle, path_leaf_bh(path));
5049 out:
5050         return ret;
5051 }
5052 
5053 /*
5054  * Split part or all of the extent record at split_index in the leaf
5055  * pointed to by path. Merge with the contiguous extent record if needed.
5056  *
5057  * Care is taken to handle contiguousness so as to not grow the tree.
5058  *
5059  * meta_ac is not strictly necessary - we only truly need it if growth
5060  * of the tree is required. All other cases will degrade into a less
5061  * optimal tree layout.
5062  *
5063  * last_eb_bh should be the rightmost leaf block for any extent
5064  * btree. Since a split may grow the tree or a merge might shrink it,
5065  * the caller cannot trust the contents of that buffer after this call.
5066  *
5067  * This code is optimized for readability - several passes might be
5068  * made over certain portions of the tree. All of those blocks will
5069  * have been brought into cache (and pinned via the journal), so the
5070  * extra overhead is not expressed in terms of disk reads.
5071  */
5072 int ocfs2_split_extent(handle_t *handle,
5073                        struct ocfs2_extent_tree *et,
5074                        struct ocfs2_path *path,
5075                        int split_index,
5076                        struct ocfs2_extent_rec *split_rec,
5077                        struct ocfs2_alloc_context *meta_ac,
5078                        struct ocfs2_cached_dealloc_ctxt *dealloc)
5079 {
5080         int ret = 0;
5081         struct ocfs2_extent_list *el = path_leaf_el(path);
5082         struct buffer_head *last_eb_bh = NULL;
5083         struct ocfs2_extent_rec *rec = &el->l_recs[split_index];
5084         struct ocfs2_merge_ctxt ctxt;
5085 
5086         if (le32_to_cpu(rec->e_cpos) > le32_to_cpu(split_rec->e_cpos) ||
5087             ((le32_to_cpu(rec->e_cpos) + le16_to_cpu(rec->e_leaf_clusters)) <
5088              (le32_to_cpu(split_rec->e_cpos) + le16_to_cpu(split_rec->e_leaf_clusters)))) {
5089                 ret = -EIO;
5090                 mlog_errno(ret);
5091                 goto out;
5092         }
5093 
5094         ret = ocfs2_figure_merge_contig_type(et, path, el,
5095                                              split_index,
5096                                              split_rec,
5097                                              &ctxt);
5098         if (ret) {
5099                 mlog_errno(ret);
5100                 goto out;
5101         }
5102 
5103         /*
5104          * The core merge / split code wants to know how much room is
5105          * left in this allocation tree, so we pass the
5106          * rightmost extent list.
5107          */
5108         if (path->p_tree_depth) {
5109                 ret = ocfs2_read_extent_block(et->et_ci,
5110                                               ocfs2_et_get_last_eb_blk(et),
5111                                               &last_eb_bh);
5112                 if (ret) {
5113                         mlog_errno(ret);
5114                         goto out;
5115                 }
5116         }
5117 
5118         if (rec->e_cpos == split_rec->e_cpos &&
5119             rec->e_leaf_clusters == split_rec->e_leaf_clusters)
5120                 ctxt.c_split_covers_rec = 1;
5121         else
5122                 ctxt.c_split_covers_rec = 0;
5123 
5124         ctxt.c_has_empty_extent = ocfs2_is_empty_extent(&el->l_recs[0]);
5125 
5126         trace_ocfs2_split_extent(split_index, ctxt.c_contig_type,
5127                                  ctxt.c_has_empty_extent,
5128                                  ctxt.c_split_covers_rec);
5129 
5130         if (ctxt.c_contig_type == CONTIG_NONE) {
5131                 if (ctxt.c_split_covers_rec)
5132                         ret = ocfs2_replace_extent_rec(handle, et, path, el,
5133                                                        split_index, split_rec);
5134                 else
5135                         ret = ocfs2_split_and_insert(handle, et, path,
5136                                                      &last_eb_bh, split_index,
5137                                                      split_rec, meta_ac);
5138                 if (ret)
5139                         mlog_errno(ret);
5140         } else {
5141                 ret = ocfs2_try_to_merge_extent(handle, et, path,
5142                                                 split_index, split_rec,
5143                                                 dealloc, &ctxt);
5144                 if (ret)
5145                         mlog_errno(ret);
5146         }
5147 
5148 out:
5149         brelse(last_eb_bh);
5150         return ret;
5151 }
5152 
5153 /*
5154  * Change the flags of the already-existing extent at cpos for len clusters.
5155  *
5156  * new_flags: the flags we want to set.
5157  * clear_flags: the flags we want to clear.
5158  * phys: the new physical offset we want this new extent starts from.
5159  *
5160  * If the existing extent is larger than the request, initiate a
5161  * split. An attempt will be made at merging with adjacent extents.
5162  *
5163  * The caller is responsible for passing down meta_ac if we'll need it.
5164  */
5165 int ocfs2_change_extent_flag(handle_t *handle,
5166                              struct ocfs2_extent_tree *et,
5167                              u32 cpos, u32 len, u32 phys,
5168                              struct ocfs2_alloc_context *meta_ac,
5169                              struct ocfs2_cached_dealloc_ctxt *dealloc,
5170                              int new_flags, int clear_flags)
5171 {
5172         int ret, index;
5173         struct super_block *sb = ocfs2_metadata_cache_get_super(et->et_ci);
5174         u64 start_blkno = ocfs2_clusters_to_blocks(sb, phys);
5175         struct ocfs2_extent_rec split_rec;
5176         struct ocfs2_path *left_path = NULL;
5177         struct ocfs2_extent_list *el;
5178         struct ocfs2_extent_rec *rec;
5179 
5180         left_path = ocfs2_new_path_from_et(et);
5181         if (!left_path) {
5182                 ret = -ENOMEM;
5183                 mlog_errno(ret);
5184                 goto out;
5185         }
5186 
5187         ret = ocfs2_find_path(et->et_ci, left_path, cpos);
5188         if (ret) {
5189                 mlog_errno(ret);
5190                 goto out;
5191         }
5192         el = path_leaf_el(left_path);
5193 
5194         index = ocfs2_search_extent_list(el, cpos);
5195         if (index == -1) {
5196                 ocfs2_error(sb,
5197                             "Owner %llu has an extent at cpos %u which can no longer be found\n",
5198                             (unsigned long long)ocfs2_metadata_cache_owner(et->et_ci),
5199                             cpos);
5200                 ret = -EROFS;
5201                 goto out;
5202         }
5203 
5204         ret = -EIO;
5205         rec = &el->l_recs[index];
5206         if (new_flags && (rec->e_flags & new_flags)) {
5207                 mlog(ML_ERROR, "Owner %llu tried to set %d flags on an "
5208                      "extent that already had them\n",
5209                      (unsigned long long)ocfs2_metadata_cache_owner(et->et_ci),
5210                      new_flags);
5211                 goto out;
5212         }
5213 
5214         if (clear_flags && !(rec->e_flags & clear_flags)) {
5215                 mlog(ML_ERROR, "Owner %llu tried to clear %d flags on an "
5216                      "extent that didn't have them\n",
5217                      (unsigned long long)ocfs2_metadata_cache_owner(et->et_ci),
5218                      clear_flags);
5219                 goto out;
5220         }
5221 
5222         memset(&split_rec, 0, sizeof(struct ocfs2_extent_rec));
5223         split_rec.e_cpos = cpu_to_le32(cpos);
5224         split_rec.e_leaf_clusters = cpu_to_le16(len);
5225         split_rec.e_blkno = cpu_to_le64(start_blkno);
5226         split_rec.e_flags = rec->e_flags;
5227         if (new_flags)
5228                 split_rec.e_flags |= new_flags;
5229         if (clear_flags)
5230                 split_rec.e_flags &= ~clear_flags;
5231 
5232         ret = ocfs2_split_extent(handle, et, left_path,
5233                                  index, &split_rec, meta_ac,
5234                                  dealloc);
5235         if (ret)
5236                 mlog_errno(ret);
5237 
5238 out:
5239         ocfs2_free_path(left_path);
5240         return ret;
5241 
5242 }
5243 
5244 /*
5245  * Mark the already-existing extent at cpos as written for len clusters.
5246  * This removes the unwritten extent flag.
5247  *
5248  * If the existing extent is larger than the request, initiate a
5249  * split. An attempt will be made at merging with adjacent extents.
5250  *
5251  * The caller is responsible for passing down meta_ac if we'll need it.
5252  */
5253 int ocfs2_mark_extent_written(struct inode *inode,
5254                               struct ocfs2_extent_tree *et,
5255                               handle_t *handle, u32 cpos, u32 len, u32 phys,
5256                               struct ocfs2_alloc_context *meta_ac,
5257                               struct ocfs2_cached_dealloc_ctxt *dealloc)
5258 {
5259         int ret;
5260 
5261         trace_ocfs2_mark_extent_written(
5262                 (unsigned long long)OCFS2_I(inode)->ip_blkno,
5263                 cpos, len, phys);
5264 
5265         if (!ocfs2_writes_unwritten_extents(OCFS2_SB(inode->i_sb))) {
5266                 ocfs2_error(inode->i_sb, "Inode %llu has unwritten extents that are being written to, but the feature bit is not set in the super block\n",
5267                             (unsigned long long)OCFS2_I(inode)->ip_blkno);
5268                 ret = -EROFS;
5269                 goto out;
5270         }
5271 
5272         /*
5273          * XXX: This should be fixed up so that we just re-insert the
5274          * next extent records.
5275          */
5276         ocfs2_et_extent_map_truncate(et, 0);
5277 
5278         ret = ocfs2_change_extent_flag(handle, et, cpos,
5279                                        len, phys, meta_ac, dealloc,
5280                                        0, OCFS2_EXT_UNWRITTEN);
5281         if (ret)
5282                 mlog_errno(ret);
5283 
5284 out:
5285         return ret;
5286 }
5287 
5288 static int ocfs2_split_tree(handle_t *handle, struct ocfs2_extent_tree *et,
5289                             struct ocfs2_path *path,
5290                             int index, u32 new_range,
5291                             struct ocfs2_alloc_context *meta_ac)
5292 {
5293         int ret, depth, credits;
5294         struct buffer_head *last_eb_bh = NULL;
5295         struct ocfs2_extent_block *eb;
5296         struct ocfs2_extent_list *rightmost_el, *el;
5297         struct ocfs2_extent_rec split_rec;
5298         struct ocfs2_extent_rec *rec;
5299         struct ocfs2_insert_type insert;
5300 
5301         /*
5302          * Setup the record to split before we grow the tree.
5303          */
5304         el = path_leaf_el(path);
5305         rec = &el->l_recs[index];
5306         ocfs2_make_right_split_rec(ocfs2_metadata_cache_get_super(et->et_ci),
5307                                    &split_rec, new_range, rec);
5308 
5309         depth = path->p_tree_depth;
5310         if (depth > 0) {
5311                 ret = ocfs2_read_extent_block(et->et_ci,
5312                                               ocfs2_et_get_last_eb_blk(et),
5313                                               &last_eb_bh);
5314                 if (ret < 0) {
5315                         mlog_errno(ret);
5316                         goto out;
5317                 }
5318 
5319                 eb = (struct ocfs2_extent_block *) last_eb_bh->b_data;
5320                 rightmost_el = &eb->h_list;
5321         } else
5322                 rightmost_el = path_leaf_el(path);
5323 
5324         credits = path->p_tree_depth +
5325                   ocfs2_extend_meta_needed(et->et_root_el);
5326         ret = ocfs2_extend_trans(handle, credits);
5327         if (ret) {
5328                 mlog_errno(ret);
5329                 goto out;
5330         }
5331 
5332         if (le16_to_cpu(rightmost_el->l_next_free_rec) ==
5333             le16_to_cpu(rightmost_el->l_count)) {
5334                 ret = ocfs2_grow_tree(handle, et, &depth, &last_eb_bh,
5335                                       meta_ac);
5336                 if (ret) {
5337                         mlog_errno(ret);
5338                         goto out;
5339                 }
5340         }
5341 
5342         memset(&insert, 0, sizeof(struct ocfs2_insert_type));
5343         insert.ins_appending = APPEND_NONE;
5344         insert.ins_contig = CONTIG_NONE;
5345         insert.ins_split = SPLIT_RIGHT;
5346         insert.ins_tree_depth = depth;
5347 
5348         ret = ocfs2_do_insert_extent(handle, et, &split_rec, &insert);
5349         if (ret)
5350                 mlog_errno(ret);
5351 
5352 out:
5353         brelse(last_eb_bh);
5354         return ret;
5355 }
5356 
5357 static int ocfs2_truncate_rec(handle_t *handle,
5358                               struct ocfs2_extent_tree *et,
5359                               struct ocfs2_path *path, int index,
5360                               struct ocfs2_cached_dealloc_ctxt *dealloc,
5361                               u32 cpos, u32 len)
5362 {
5363         int ret;
5364         u32 left_cpos, rec_range, trunc_range;
5365         int is_rightmost_tree_rec = 0;
5366         struct super_block *sb = ocfs2_metadata_cache_get_super(et->et_ci);
5367         struct ocfs2_path *left_path = NULL;
5368         struct ocfs2_extent_list *el = path_leaf_el(path);
5369         struct ocfs2_extent_rec *rec;
5370         struct ocfs2_extent_block *eb;
5371 
5372         if (ocfs2_is_empty_extent(&el->l_recs[0]) && index > 0) {
5373                 /* extend credit for ocfs2_remove_rightmost_path */
5374                 ret = ocfs2_extend_rotate_transaction(handle, 0,
5375                                 handle->h_buffer_credits,
5376                                 path);
5377                 if (ret) {
5378                         mlog_errno(ret);
5379                         goto out;
5380                 }
5381 
5382                 ret = ocfs2_rotate_tree_left(handle, et, path, dealloc);
5383                 if (ret) {
5384                         mlog_errno(ret);
5385                         goto out;
5386                 }
5387 
5388                 index--;
5389         }
5390 
5391         if (index == (le16_to_cpu(el->l_next_free_rec) - 1) &&
5392             path->p_tree_depth) {
5393                 /*
5394                  * Check whether this is the rightmost tree record. If
5395                  * we remove all of this record or part of its right
5396                  * edge then an update of the record lengths above it
5397                  * will be required.
5398                  */
5399                 eb = (struct ocfs2_extent_block *)path_leaf_bh(path)->b_data;
5400                 if (eb->h_next_leaf_blk == 0)
5401                         is_rightmost_tree_rec = 1;
5402         }
5403 
5404         rec = &el->l_recs[index];
5405         if (index == 0 && path->p_tree_depth &&
5406             le32_to_cpu(rec->e_cpos) == cpos) {
5407                 /*
5408                  * Changing the leftmost offset (via partial or whole
5409                  * record truncate) of an interior (or rightmost) path
5410                  * means we have to update the subtree that is formed
5411                  * by this leaf and the one to it's left.
5412                  *
5413                  * There are two cases we can skip:
5414                  *   1) Path is the leftmost one in our btree.
5415                  *   2) The leaf is rightmost and will be empty after
5416                  *      we remove the extent record - the rotate code
5417                  *      knows how to update the newly formed edge.
5418                  */
5419 
5420                 ret = ocfs2_find_cpos_for_left_leaf(sb, path, &left_cpos);
5421                 if (ret) {
5422                         mlog_errno(ret);
5423                         goto out;
5424                 }
5425 
5426                 if (left_cpos && le16_to_cpu(el->l_next_free_rec) > 1) {
5427                         left_path = ocfs2_new_path_from_path(path);
5428                         if (!left_path) {
5429                                 ret = -ENOMEM;
5430                                 mlog_errno(ret);
5431                                 goto out;
5432                         }
5433 
5434                         ret = ocfs2_find_path(et->et_ci, left_path,
5435                                               left_cpos);
5436                         if (ret) {
5437                                 mlog_errno(ret);
5438                                 goto out;
5439                         }
5440                 }
5441         }
5442 
5443         ret = ocfs2_extend_rotate_transaction(handle, 0,
5444                                               handle->h_buffer_credits,
5445                                               path);
5446         if (ret) {
5447                 mlog_errno(ret);
5448                 goto out;
5449         }
5450 
5451         ret = ocfs2_journal_access_path(et->et_ci, handle, path);
5452         if (ret) {
5453                 mlog_errno(ret);
5454                 goto out;
5455         }
5456 
5457         ret = ocfs2_journal_access_path(et->et_ci, handle, left_path);
5458         if (ret) {
5459                 mlog_errno(ret);
5460                 goto out;
5461         }
5462 
5463         rec_range = le32_to_cpu(rec->e_cpos) + ocfs2_rec_clusters(el, rec);
5464         trunc_range = cpos + len;
5465 
5466         if (le32_to_cpu(rec->e_cpos) == cpos && rec_range == trunc_range) {
5467                 int next_free;
5468 
5469                 memset(rec, 0, sizeof(*rec));
5470                 ocfs2_cleanup_merge(el, index);
5471 
5472                 next_free = le16_to_cpu(el->l_next_free_rec);
5473                 if (is_rightmost_tree_rec && next_free > 1) {
5474                         /*
5475                          * We skip the edge update if this path will
5476                          * be deleted by the rotate code.
5477                          */
5478                         rec = &el->l_recs[next_free - 1];
5479                         ocfs2_adjust_rightmost_records(handle, et, path,
5480                                                        rec);
5481                 }
5482         } else if (le32_to_cpu(rec->e_cpos) == cpos) {
5483                 /* Remove leftmost portion of the record. */
5484                 le32_add_cpu(&rec->e_cpos, len);
5485                 le64_add_cpu(&rec->e_blkno, ocfs2_clusters_to_blocks(sb, len));
5486                 le16_add_cpu(&rec->e_leaf_clusters, -len);
5487         } else if (rec_range == trunc_range) {
5488                 /* Remove rightmost portion of the record */
5489                 le16_add_cpu(&rec->e_leaf_clusters, -len);
5490                 if (is_rightmost_tree_rec)
5491                         ocfs2_adjust_rightmost_records(handle, et, path, rec);
5492         } else {
5493                 /* Caller should have trapped this. */
5494                 mlog(ML_ERROR, "Owner %llu: Invalid record truncate: (%u, %u) "
5495                      "(%u, %u)\n",
5496                      (unsigned long long)ocfs2_metadata_cache_owner(et->et_ci),
5497                      le32_to_cpu(rec->e_cpos),
5498                      le16_to_cpu(rec->e_leaf_clusters), cpos, len);
5499                 BUG();
5500         }
5501 
5502         if (left_path) {
5503                 int subtree_index;
5504 
5505                 subtree_index = ocfs2_find_subtree_root(et, left_path, path);
5506                 ocfs2_complete_edge_insert(handle, left_path, path,
5507                                            subtree_index);
5508         }
5509 
5510         ocfs2_journal_dirty(handle, path_leaf_bh(path));
5511 
5512         ret = ocfs2_rotate_tree_left(handle, et, path, dealloc);
5513         if (ret)
5514                 mlog_errno(ret);
5515 
5516 out:
5517         ocfs2_free_path(left_path);
5518         return ret;
5519 }
5520 
5521 int ocfs2_remove_extent(handle_t *handle,
5522                         struct ocfs2_extent_tree *et,
5523                         u32 cpos, u32 len,
5524                         struct ocfs2_alloc_context *meta_ac,
5525                         struct ocfs2_cached_dealloc_ctxt *dealloc)
5526 {
5527         int ret, index;
5528         u32 rec_range, trunc_range;
5529         struct ocfs2_extent_rec *rec;
5530         struct ocfs2_extent_list *el;
5531         struct ocfs2_path *path = NULL;
5532 
5533         /*
5534          * XXX: Why are we truncating to 0 instead of wherever this
5535          * affects us?
5536          */
5537         ocfs2_et_extent_map_truncate(et, 0);
5538 
5539         path = ocfs2_new_path_from_et(et);
5540         if (!path) {
5541                 ret = -ENOMEM;
5542                 mlog_errno(ret);
5543                 goto out;
5544         }
5545 
5546         ret = ocfs2_find_path(et->et_ci, path, cpos);
5547         if (ret) {
5548                 mlog_errno(ret);
5549                 goto out;
5550         }
5551 
5552         el = path_leaf_el(path);
5553         index = ocfs2_search_extent_list(el, cpos);
5554         if (index == -1) {
5555                 ocfs2_error(ocfs2_metadata_cache_get_super(et->et_ci),
5556                             "Owner %llu has an extent at cpos %u which can no longer be found\n",
5557                             (unsigned long long)ocfs2_metadata_cache_owner(et->et_ci),
5558                             cpos);
5559                 ret = -EROFS;
5560                 goto out;
5561         }
5562 
5563         /*
5564          * We have 3 cases of extent removal:
5565          *   1) Range covers the entire extent rec
5566          *   2) Range begins or ends on one edge of the extent rec
5567          *   3) Range is in the middle of the extent rec (no shared edges)
5568          *
5569          * For case 1 we remove the extent rec and left rotate to
5570          * fill the hole.
5571          *
5572          * For case 2 we just shrink the existing extent rec, with a
5573          * tree update if the shrinking edge is also the edge of an
5574          * extent block.
5575          *
5576          * For case 3 we do a right split to turn the extent rec into
5577          * something case 2 can handle.
5578          */
5579         rec = &el->l_recs[index];
5580         rec_range = le32_to_cpu(rec->e_cpos) + ocfs2_rec_clusters(el, rec);
5581         trunc_range = cpos + len;
5582 
5583         BUG_ON(cpos < le32_to_cpu(rec->e_cpos) || trunc_range > rec_range);
5584 
5585         trace_ocfs2_remove_extent(
5586                 (unsigned long long)ocfs2_metadata_cache_owner(et->et_ci),
5587                 cpos, len, index, le32_to_cpu(rec->e_cpos),
5588                 ocfs2_rec_clusters(el, rec));
5589 
5590         if (le32_to_cpu(rec->e_cpos) == cpos || rec_range == trunc_range) {
5591                 ret = ocfs2_truncate_rec(handle, et, path, index, dealloc,
5592                                          cpos, len);
5593                 if (ret) {
5594                         mlog_errno(ret);
5595                         goto out;
5596                 }
5597         } else {
5598                 ret = ocfs2_split_tree(handle, et, path, index,
5599                                        trunc_range, meta_ac);
5600                 if (ret) {
5601                         mlog_errno(ret);
5602                         goto out;
5603                 }
5604 
5605                 /*
5606                  * The split could have manipulated the tree enough to
5607                  * move the record location, so we have to look for it again.
5608                  */
5609                 ocfs2_reinit_path(path, 1);
5610 
5611                 ret = ocfs2_find_path(et->et_ci, path, cpos);
5612                 if (ret) {
5613                         mlog_errno(ret);
5614                         goto out;
5615                 }
5616 
5617                 el = path_leaf_el(path);
5618                 index = ocfs2_search_extent_list(el, cpos);
5619                 if (index == -1) {
5620                         ocfs2_error(ocfs2_metadata_cache_get_super(et->et_ci),
5621                                     "Owner %llu: split at cpos %u lost record\n",
5622                                     (unsigned long long)ocfs2_metadata_cache_owner(et->et_ci),
5623                                     cpos);
5624                         ret = -EROFS;
5625                         goto out;
5626                 }
5627 
5628                 /*
5629                  * Double check our values here. If anything is fishy,
5630                  * it's easier to catch it at the top level.
5631                  */
5632                 rec = &el->l_recs[index];
5633                 rec_range = le32_to_cpu(rec->e_cpos) +
5634                         ocfs2_rec_clusters(el, rec);
5635                 if (rec_range != trunc_range) {
5636                         ocfs2_error(ocfs2_metadata_cache_get_super(et->et_ci),
5637                                     "Owner %llu: error after split at cpos %u trunc len %u, existing record is (%u,%u)\n",
5638                                     (unsigned long long)ocfs2_metadata_cache_owner(et->et_ci),
5639                                     cpos, len, le32_to_cpu(rec->e_cpos),
5640                                     ocfs2_rec_clusters(el, rec));
5641                         ret = -EROFS;
5642                         goto out;
5643                 }
5644 
5645                 ret = ocfs2_truncate_rec(handle, et, path, index, dealloc,
5646                                          cpos, len);
5647                 if (ret)
5648                         mlog_errno(ret);
5649         }
5650 
5651 out:
5652         ocfs2_free_path(path);
5653         return ret;
5654 }
5655 
5656 /*
5657  * ocfs2_reserve_blocks_for_rec_trunc() would look basically the
5658  * same as ocfs2_lock_alloctors(), except for it accepts a blocks
5659  * number to reserve some extra blocks, and it only handles meta
5660  * data allocations.
5661  *
5662  * Currently, only ocfs2_remove_btree_range() uses it for truncating
5663  * and punching holes.
5664  */
5665 static int ocfs2_reserve_blocks_for_rec_trunc(struct inode *inode,
5666                                               struct ocfs2_extent_tree *et,
5667                                               u32 extents_to_split,
5668                                               struct ocfs2_alloc_context **ac,
5669                                               int extra_blocks)
5670 {
5671         int ret = 0, num_free_extents;
5672         unsigned int max_recs_needed = 2 * extents_to_split;
5673         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
5674 
5675         *ac = NULL;
5676 
5677         num_free_extents = ocfs2_num_free_extents(et);
5678         if (num_free_extents < 0) {
5679                 ret = num_free_extents;
5680                 mlog_errno(ret);
5681                 goto out;
5682         }
5683 
5684         if (!num_free_extents ||
5685             (ocfs2_sparse_alloc(osb) && num_free_extents < max_recs_needed))
5686                 extra_blocks += ocfs2_extend_meta_needed(et->et_root_el);
5687 
5688         if (extra_blocks) {
5689                 ret = ocfs2_reserve_new_metadata_blocks(osb, extra_blocks, ac);
5690                 if (ret < 0) {
5691                         if (ret != -ENOSPC)
5692                                 mlog_errno(ret);
5693                 }
5694         }
5695 
5696 out:
5697         if (ret) {
5698                 if (*ac) {
5699                         ocfs2_free_alloc_context(*ac);
5700                         *ac = NULL;
5701                 }
5702         }
5703 
5704         return ret;
5705 }
5706 
5707 int ocfs2_remove_btree_range(struct inode *inode,
5708                              struct ocfs2_extent_tree *et,
5709                              u32 cpos, u32 phys_cpos, u32 len, int flags,
5710                              struct ocfs2_cached_dealloc_ctxt *dealloc,
5711                              u64 refcount_loc, bool refcount_tree_locked)
5712 {
5713         int ret, credits = 0, extra_blocks = 0;
5714         u64 phys_blkno = ocfs2_clusters_to_blocks(inode->i_sb, phys_cpos);
5715         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
5716         struct inode *tl_inode = osb->osb_tl_inode;
5717         handle_t *handle;
5718         struct ocfs2_alloc_context *meta_ac = NULL;
5719         struct ocfs2_refcount_tree *ref_tree = NULL;
5720 
5721         if ((flags & OCFS2_EXT_REFCOUNTED) && len) {
5722                 BUG_ON(!ocfs2_is_refcount_inode(inode));
5723 
5724                 if (!refcount_tree_locked) {
5725                         ret = ocfs2_lock_refcount_tree(osb, refcount_loc, 1,
5726                                                        &ref_tree, NULL);
5727                         if (ret) {
5728                                 mlog_errno(ret);
5729                                 goto bail;
5730                         }
5731                 }
5732 
5733                 ret = ocfs2_prepare_refcount_change_for_del(inode,
5734                                                             refcount_loc,
5735                                                             phys_blkno,
5736                                                             len,
5737                                                             &credits,
5738                                                             &extra_blocks);
5739                 if (ret < 0) {
5740                         mlog_errno(ret);
5741                         goto bail;
5742                 }
5743         }
5744 
5745         ret = ocfs2_reserve_blocks_for_rec_trunc(inode, et, 1, &meta_ac,
5746                                                  extra_blocks);
5747         if (ret) {
5748                 mlog_errno(ret);
5749                 goto bail;
5750         }
5751 
5752         inode_lock(tl_inode);
5753 
5754         if (ocfs2_truncate_log_needs_flush(osb)) {
5755                 ret = __ocfs2_flush_truncate_log(osb);
5756                 if (ret < 0) {
5757                         mlog_errno(ret);
5758                         goto out;
5759                 }
5760         }
5761 
5762         handle = ocfs2_start_trans(osb,
5763                         ocfs2_remove_extent_credits(osb->sb) + credits);
5764         if (IS_ERR(handle)) {
5765                 ret = PTR_ERR(handle);
5766                 mlog_errno(ret);
5767                 goto out;
5768         }
5769 
5770         ret = ocfs2_et_root_journal_access(handle, et,
5771                                            OCFS2_JOURNAL_ACCESS_WRITE);
5772         if (ret) {
5773                 mlog_errno(ret);
5774                 goto out_commit;
5775         }
5776 
5777         dquot_free_space_nodirty(inode,
5778                                   ocfs2_clusters_to_bytes(inode->i_sb, len));
5779 
5780         ret = ocfs2_remove_extent(handle, et, cpos, len, meta_ac, dealloc);
5781         if (ret) {
5782                 mlog_errno(ret);
5783                 goto out_commit;
5784         }
5785 
5786         ocfs2_et_update_clusters(et, -len);
5787         ocfs2_update_inode_fsync_trans(handle, inode, 1);
5788 
5789         ocfs2_journal_dirty(handle, et->et_root_bh);
5790 
5791         if (phys_blkno) {
5792                 if (flags & OCFS2_EXT_REFCOUNTED)
5793                         ret = ocfs2_decrease_refcount(inode, handle,
5794                                         ocfs2_blocks_to_clusters(osb->sb,
5795                                                                  phys_blkno),
5796                                         len, meta_ac,
5797                                         dealloc, 1);
5798                 else
5799                         ret = ocfs2_truncate_log_append(osb, handle,
5800                                                         phys_blkno, len);
5801                 if (ret)
5802                         mlog_errno(ret);
5803 
5804         }
5805 
5806 out_commit:
5807         ocfs2_commit_trans(osb, handle);
5808 out:
5809         inode_unlock(tl_inode);
5810 bail:
5811         if (meta_ac)
5812                 ocfs2_free_alloc_context(meta_ac);
5813 
5814         if (ref_tree)
5815                 ocfs2_unlock_refcount_tree(osb, ref_tree, 1);
5816 
5817         return ret;
5818 }
5819 
5820 int ocfs2_truncate_log_needs_flush(struct ocfs2_super *osb)
5821 {
5822         struct buffer_head *tl_bh = osb->osb_tl_bh;
5823         struct ocfs2_dinode *di;
5824         struct ocfs2_truncate_log *tl;
5825 
5826         di = (struct ocfs2_dinode *) tl_bh->b_data;
5827         tl = &di->id2.i_dealloc;
5828 
5829         mlog_bug_on_msg(le16_to_cpu(tl->tl_used) > le16_to_cpu(tl->tl_count),
5830                         "slot %d, invalid truncate log parameters: used = "
5831                         "%u, count = %u\n", osb->slot_num,
5832                         le16_to_cpu(tl->tl_used), le16_to_cpu(tl->tl_count));
5833         return le16_to_cpu(tl->tl_used) == le16_to_cpu(tl->tl_count);
5834 }
5835 
5836 static int ocfs2_truncate_log_can_coalesce(struct ocfs2_truncate_log *tl,
5837                                            unsigned int new_start)
5838 {
5839         unsigned int tail_index;
5840         unsigned int current_tail;
5841 
5842         /* No records, nothing to coalesce */
5843         if (!le16_to_cpu(tl->tl_used))
5844                 return 0;
5845 
5846         tail_index = le16_to_cpu(tl->tl_used) - 1;
5847         current_tail = le32_to_cpu(tl->tl_recs[tail_index].t_start);
5848         current_tail += le32_to_cpu(tl->tl_recs[tail_index].t_clusters);
5849 
5850         return current_tail == new_start;
5851 }
5852 
5853 int ocfs2_truncate_log_append(struct ocfs2_super *osb,
5854                               handle_t *handle,
5855                               u64 start_blk,
5856                               unsigned int num_clusters)
5857 {
5858         int status, index;
5859         unsigned int start_cluster, tl_count;
5860         struct inode *tl_inode = osb->osb_tl_inode;
5861         struct buffer_head *tl_bh = osb->osb_tl_bh;
5862         struct ocfs2_dinode *di;
5863         struct ocfs2_truncate_log *tl;
5864 
5865         BUG_ON(inode_trylock(tl_inode));
5866 
5867         start_cluster = ocfs2_blocks_to_clusters(osb->sb, start_blk);
5868 
5869         di = (struct ocfs2_dinode *) tl_bh->b_data;
5870 
5871         /* tl_bh is loaded from ocfs2_truncate_log_init().  It's validated
5872          * by the underlying call to ocfs2_read_inode_block(), so any
5873          * corruption is a code bug */
5874         BUG_ON(!OCFS2_IS_VALID_DINODE(di));
5875 
5876         tl = &di->id2.i_dealloc;
5877         tl_count = le16_to_cpu(tl->tl_count);
5878         mlog_bug_on_msg(tl_count > ocfs2_truncate_recs_per_inode(osb->sb) ||
5879                         tl_count == 0,
5880                         "Truncate record count on #%llu invalid "
5881                         "wanted %u, actual %u\n",
5882                         (unsigned long long)OCFS2_I(tl_inode)->ip_blkno,
5883                         ocfs2_truncate_recs_per_inode(osb->sb),
5884                         le16_to_cpu(tl->tl_count));
5885 
5886         /* Caller should have known to flush before calling us. */
5887         index = le16_to_cpu(tl->tl_used);
5888         if (index >= tl_count) {
5889                 status = -ENOSPC;
5890                 mlog_errno(status);
5891                 goto bail;
5892         }
5893 
5894         status = ocfs2_journal_access_di(handle, INODE_CACHE(tl_inode), tl_bh,
5895                                          OCFS2_JOURNAL_ACCESS_WRITE);
5896         if (status < 0) {
5897                 mlog_errno(status);
5898                 goto bail;
5899         }
5900 
5901         trace_ocfs2_truncate_log_append(
5902                 (unsigned long long)OCFS2_I(tl_inode)->ip_blkno, index,
5903                 start_cluster, num_clusters);
5904         if (ocfs2_truncate_log_can_coalesce(tl, start_cluster)) {
5905                 /*
5906                  * Move index back to the record we are coalescing with.
5907                  * ocfs2_truncate_log_can_coalesce() guarantees nonzero
5908                  */
5909                 index--;
5910 
5911                 num_clusters += le32_to_cpu(tl->tl_recs[index].t_clusters);
5912                 trace_ocfs2_truncate_log_append(
5913                         (unsigned long long)OCFS2_I(tl_inode)->ip_blkno,
5914                         index, le32_to_cpu(tl->tl_recs[index].t_start),
5915                         num_clusters);
5916         } else {
5917                 tl->tl_recs[index].t_start = cpu_to_le32(start_cluster);
5918                 tl->tl_used = cpu_to_le16(index + 1);
5919         }
5920         tl->tl_recs[index].t_clusters = cpu_to_le32(num_clusters);
5921 
5922         ocfs2_journal_dirty(handle, tl_bh);
5923 
5924         osb->truncated_clusters += num_clusters;
5925 bail:
5926         return status;
5927 }
5928 
5929 static int ocfs2_replay_truncate_records(struct ocfs2_super *osb,
5930                                          struct inode *data_alloc_inode,
5931                                          struct buffer_head *data_alloc_bh)
5932 {
5933         int status = 0;
5934         int i;
5935         unsigned int num_clusters;
5936         u64 start_blk;
5937         struct ocfs2_truncate_rec rec;
5938         struct ocfs2_dinode *di;
5939         struct ocfs2_truncate_log *tl;
5940         struct inode *tl_inode = osb->osb_tl_inode;
5941         struct buffer_head *tl_bh = osb->osb_tl_bh;
5942         handle_t *handle;
5943 
5944         di = (struct ocfs2_dinode *) tl_bh->b_data;
5945         tl = &di->id2.i_dealloc;
5946         i = le16_to_cpu(tl->tl_used) - 1;
5947         while (i >= 0) {
5948                 handle = ocfs2_start_trans(osb, OCFS2_TRUNCATE_LOG_FLUSH_ONE_REC);
5949                 if (IS_ERR(handle)) {
5950                         status = PTR_ERR(handle);
5951                         mlog_errno(status);
5952                         goto bail;
5953                 }
5954 
5955                 /* Caller has given us at least enough credits to
5956                  * update the truncate log dinode */
5957                 status = ocfs2_journal_access_di(handle, INODE_CACHE(tl_inode), tl_bh,
5958                                                  OCFS2_JOURNAL_ACCESS_WRITE);
5959                 if (status < 0) {
5960                         mlog_errno(status);
5961                         goto bail;
5962                 }
5963 
5964                 tl->tl_used = cpu_to_le16(i);
5965 
5966                 ocfs2_journal_dirty(handle, tl_bh);
5967 
5968                 rec = tl->tl_recs[i];
5969                 start_blk = ocfs2_clusters_to_blocks(data_alloc_inode->i_sb,
5970                                                     le32_to_cpu(rec.t_start));
5971                 num_clusters = le32_to_cpu(rec.t_clusters);
5972 
5973                 /* if start_blk is not set, we ignore the record as
5974                  * invalid. */
5975                 if (start_blk) {
5976                         trace_ocfs2_replay_truncate_records(
5977                                 (unsigned long long)OCFS2_I(tl_inode)->ip_blkno,
5978                                 i, le32_to_cpu(rec.t_start), num_clusters);
5979 
5980                         status = ocfs2_free_clusters(handle, data_alloc_inode,
5981                                                      data_alloc_bh, start_blk,
5982                                                      num_clusters);
5983                         if (status < 0) {
5984                                 mlog_errno(status);
5985                                 goto bail;
5986                         }
5987                 }
5988 
5989                 ocfs2_commit_trans(osb, handle);
5990                 i--;
5991         }
5992 
5993         osb->truncated_clusters = 0;
5994 
5995 bail:
5996         return status;
5997 }
5998 
5999 /* Expects you to already be holding tl_inode->i_mutex */
6000 int __ocfs2_flush_truncate_log(struct ocfs2_super *osb)
6001 {
6002         int status;
6003         unsigned int num_to_flush;
6004         struct inode *tl_inode = osb->osb_tl_inode;
6005         struct inode *data_alloc_inode = NULL;
6006         struct buffer_head *tl_bh = osb->osb_tl_bh;
6007         struct buffer_head *data_alloc_bh = NULL;
6008         struct ocfs2_dinode *di;
6009         struct ocfs2_truncate_log *tl;
6010 
6011         BUG_ON(inode_trylock(tl_inode));
6012 
6013         di = (struct ocfs2_dinode *) tl_bh->b_data;
6014 
6015         /* tl_bh is loaded from ocfs2_truncate_log_init().  It's validated
6016          * by the underlying call to ocfs2_read_inode_block(), so any
6017          * corruption is a code bug */
6018         BUG_ON(!OCFS2_IS_VALID_DINODE(di));
6019 
6020         tl = &di->id2.i_dealloc;
6021         num_to_flush = le16_to_cpu(tl->tl_used);
6022         trace_ocfs2_flush_truncate_log(
6023                 (unsigned long long)OCFS2_I(tl_inode)->ip_blkno,
6024                 num_to_flush);
6025         if (!num_to_flush) {
6026                 status = 0;
6027                 goto out;
6028         }
6029 
6030         data_alloc_inode = ocfs2_get_system_file_inode(osb,
6031                                                        GLOBAL_BITMAP_SYSTEM_INODE,
6032                                                        OCFS2_INVALID_SLOT);
6033         if (!data_alloc_inode) {
6034                 status = -EINVAL;
6035                 mlog(ML_ERROR, "Could not get bitmap inode!\n");
6036                 goto out;
6037         }
6038 
6039         inode_lock(data_alloc_inode);
6040 
6041         status = ocfs2_inode_lock(data_alloc_inode, &data_alloc_bh, 1);
6042         if (status < 0) {
6043                 mlog_errno(status);
6044                 goto out_mutex;
6045         }
6046 
6047         status = ocfs2_replay_truncate_records(osb, data_alloc_inode,
6048                                                data_alloc_bh);
6049         if (status < 0)
6050                 mlog_errno(status);
6051 
6052         brelse(data_alloc_bh);
6053         ocfs2_inode_unlock(data_alloc_inode, 1);
6054 
6055 out_mutex:
6056         inode_unlock(data_alloc_inode);
6057         iput(data_alloc_inode);
6058 
6059 out:
6060         return status;
6061 }
6062 
6063 int ocfs2_flush_truncate_log(struct ocfs2_super *osb)
6064 {
6065         int status;
6066         struct inode *tl_inode = osb->osb_tl_inode;
6067 
6068         inode_lock(tl_inode);
6069         status = __ocfs2_flush_truncate_log(osb);
6070         inode_unlock(tl_inode);
6071 
6072         return status;
6073 }
6074 
6075 static void ocfs2_truncate_log_worker(struct work_struct *work)
6076 {
6077         int status;
6078         struct ocfs2_super *osb =
6079                 container_of(work, struct ocfs2_super,
6080                              osb_truncate_log_wq.work);
6081 
6082         status = ocfs2_flush_truncate_log(osb);
6083         if (status < 0)
6084                 mlog_errno(status);
6085         else
6086                 ocfs2_init_steal_slots(osb);
6087 }
6088 
6089 #define OCFS2_TRUNCATE_LOG_FLUSH_INTERVAL (2 * HZ)
6090 void ocfs2_schedule_truncate_log_flush(struct ocfs2_super *osb,
6091                                        int cancel)
6092 {
6093         if (osb->osb_tl_inode &&
6094                         atomic_read(&osb->osb_tl_disable) == 0) {
6095                 /* We want to push off log flushes while truncates are
6096                  * still running. */
6097                 if (cancel)
6098                         cancel_delayed_work(&osb->osb_truncate_log_wq);
6099 
6100                 queue_delayed_work(osb->ocfs2_wq, &osb->osb_truncate_log_wq,
6101                                    OCFS2_TRUNCATE_LOG_FLUSH_INTERVAL);
6102         }
6103 }
6104 
6105 /*
6106  * Try to flush truncate logs if we can free enough clusters from it.
6107  * As for return value, "< 0" means error, "" no space and "1" means
6108  * we have freed enough spaces and let the caller try to allocate again.
6109  */
6110 int ocfs2_try_to_free_truncate_log(struct ocfs2_super *osb,
6111                                         unsigned int needed)
6112 {
6113         tid_t target;
6114         int ret = 0;
6115         unsigned int truncated_clusters;
6116 
6117         inode_lock(osb->osb_tl_inode);
6118         truncated_clusters = osb->truncated_clusters;
6119         inode_unlock(osb->osb_tl_inode);
6120 
6121         /*
6122          * Check whether we can succeed in allocating if we free
6123          * the truncate log.
6124          */
6125         if (truncated_clusters < needed)
6126                 goto out;
6127 
6128         ret = ocfs2_flush_truncate_log(osb);
6129         if (ret) {
6130                 mlog_errno(ret);
6131                 goto out;
6132         }
6133 
6134         if (jbd2_journal_start_commit(osb->journal->j_journal, &target)) {
6135                 jbd2_log_wait_commit(osb->journal->j_journal, target);
6136                 ret = 1;
6137         }
6138 out:
6139         return ret;
6140 }
6141 
6142 static int ocfs2_get_truncate_log_info(struct ocfs2_super *osb,
6143                                        int slot_num,
6144                                        struct inode **tl_inode,
6145                                        struct buffer_head **tl_bh)
6146 {
6147         int status;
6148         struct inode *inode = NULL;
6149         struct buffer_head *bh = NULL;
6150 
6151         inode = ocfs2_get_system_file_inode(osb,
6152                                            TRUNCATE_LOG_SYSTEM_INODE,
6153                                            slot_num);
6154         if (!inode) {
6155                 status = -EINVAL;
6156                 mlog(ML_ERROR, "Could not get load truncate log inode!\n");
6157                 goto bail;
6158         }
6159 
6160         status = ocfs2_read_inode_block(inode, &bh);
6161         if (status < 0) {
6162                 iput(inode);
6163                 mlog_errno(status);
6164                 goto bail;
6165         }
6166 
6167         *tl_inode = inode;
6168         *tl_bh    = bh;
6169 bail:
6170         return status;
6171 }
6172 
6173 /* called during the 1st stage of node recovery. we stamp a clean
6174  * truncate log and pass back a copy for processing later. if the
6175  * truncate log does not require processing, a *tl_copy is set to
6176  * NULL. */
6177 int ocfs2_begin_truncate_log_recovery(struct ocfs2_super *osb,
6178                                       int slot_num,
6179                                       struct ocfs2_dinode **tl_copy)
6180 {
6181         int status;
6182         struct inode *tl_inode = NULL;
6183         struct buffer_head *tl_bh = NULL;
6184         struct ocfs2_dinode *di;
6185         struct ocfs2_truncate_log *tl;
6186 
6187         *tl_copy = NULL;
6188 
6189         trace_ocfs2_begin_truncate_log_recovery(slot_num);
6190 
6191         status = ocfs2_get_truncate_log_info(osb, slot_num, &tl_inode, &tl_bh);
6192         if (status < 0) {
6193                 mlog_errno(status);
6194                 goto bail;
6195         }
6196 
6197         di = (struct ocfs2_dinode *) tl_bh->b_data;
6198 
6199         /* tl_bh is loaded from ocfs2_get_truncate_log_info().  It's
6200          * validated by the underlying call to ocfs2_read_inode_block(),
6201          * so any corruption is a code bug */
6202         BUG_ON(!OCFS2_IS_VALID_DINODE(di));
6203 
6204         tl = &di->id2.i_dealloc;
6205         if (le16_to_cpu(tl->tl_used)) {
6206                 trace_ocfs2_truncate_log_recovery_num(le16_to_cpu(tl->tl_used));
6207 
6208                 *tl_copy = kmalloc(tl_bh->b_size, GFP_KERNEL);
6209                 if (!(*tl_copy)) {
6210                         status = -ENOMEM;
6211                         mlog_errno(status);
6212                         goto bail;
6213                 }
6214 
6215                 /* Assuming the write-out below goes well, this copy
6216                  * will be passed back to recovery for processing. */
6217                 memcpy(*tl_copy, tl_bh->b_data, tl_bh->b_size);
6218 
6219                 /* All we need to do to clear the truncate log is set
6220                  * tl_used. */
6221                 tl->tl_used = 0;
6222 
6223                 ocfs2_compute_meta_ecc(osb->sb, tl_bh->b_data, &di->i_check);
6224                 status = ocfs2_write_block(osb, tl_bh, INODE_CACHE(tl_inode));
6225                 if (status < 0) {
6226                         mlog_errno(status);
6227                         goto bail;
6228                 }
6229         }
6230 
6231 bail:
6232         iput(tl_inode);
6233         brelse(tl_bh);
6234 
6235         if (status < 0) {
6236                 kfree(*tl_copy);
6237                 *tl_copy = NULL;
6238                 mlog_errno(status);
6239         }
6240 
6241         return status;
6242 }
6243 
6244 int ocfs2_complete_truncate_log_recovery(struct ocfs2_super *osb,
6245                                          struct ocfs2_dinode *tl_copy)
6246 {
6247         int status = 0;
6248         int i;
6249         unsigned int clusters, num_recs, start_cluster;
6250         u64 start_blk;
6251         handle_t *handle;
6252         struct inode *tl_inode = osb->osb_tl_inode;
6253         struct ocfs2_truncate_log *tl;
6254 
6255         if (OCFS2_I(tl_inode)->ip_blkno == le64_to_cpu(tl_copy->i_blkno)) {
6256                 mlog(ML_ERROR, "Asked to recover my own truncate log!\n");
6257                 return -EINVAL;
6258         }
6259 
6260         tl = &tl_copy->id2.i_dealloc;
6261         num_recs = le16_to_cpu(tl->tl_used);
6262         trace_ocfs2_complete_truncate_log_recovery(
6263                 (unsigned long long)le64_to_cpu(tl_copy->i_blkno),
6264                 num_recs);
6265 
6266         inode_lock(tl_inode);
6267         for(i = 0; i < num_recs; i++) {
6268                 if (ocfs2_truncate_log_needs_flush(osb)) {
6269                         status = __ocfs2_flush_truncate_log(osb);
6270                         if (status < 0) {
6271                                 mlog_errno(status);
6272                                 goto bail_up;
6273                         }
6274                 }
6275 
6276                 handle = ocfs2_start_trans(osb, OCFS2_TRUNCATE_LOG_UPDATE);
6277                 if (IS_ERR(handle)) {
6278                         status = PTR_ERR(handle);
6279                         mlog_errno(status);
6280                         goto bail_up;
6281                 }
6282 
6283                 clusters = le32_to_cpu(tl->tl_recs[i].t_clusters);
6284                 start_cluster = le32_to_cpu(tl->tl_recs[i].t_start);
6285                 start_blk = ocfs2_clusters_to_blocks(osb->sb, start_cluster);
6286 
6287                 status = ocfs2_truncate_log_append(osb, handle,
6288                                                    start_blk, clusters);
6289                 ocfs2_commit_trans(osb, handle);
6290                 if (status < 0) {
6291                         mlog_errno(status);
6292                         goto bail_up;
6293                 }
6294         }
6295 
6296 bail_up:
6297         inode_unlock(tl_inode);
6298 
6299         return status;
6300 }
6301 
6302 void ocfs2_truncate_log_shutdown(struct ocfs2_super *osb)
6303 {
6304         int status;
6305         struct inode *tl_inode = osb->osb_tl_inode;
6306 
6307         atomic_set(&osb->osb_tl_disable, 1);
6308 
6309         if (tl_inode) {
6310                 cancel_delayed_work(&osb->osb_truncate_log_wq);
6311                 flush_workqueue(osb->ocfs2_wq);
6312 
6313                 status = ocfs2_flush_truncate_log(osb);
6314                 if (status < 0)
6315                         mlog_errno(status);
6316 
6317                 brelse(osb->osb_tl_bh);
6318                 iput(osb->osb_tl_inode);
6319         }
6320 }
6321 
6322 int ocfs2_truncate_log_init(struct ocfs2_super *osb)
6323 {
6324         int status;
6325         struct inode *tl_inode = NULL;
6326         struct buffer_head *tl_bh = NULL;
6327 
6328         status = ocfs2_get_truncate_log_info(osb,
6329                                              osb->slot_num,
6330                                              &tl_inode,
6331                                              &tl_bh);
6332         if (status < 0)
6333                 mlog_errno(status);
6334 
6335         /* ocfs2_truncate_log_shutdown keys on the existence of
6336          * osb->osb_tl_inode so we don't set any of the osb variables
6337          * until we're sure all is well. */
6338         INIT_DELAYED_WORK(&osb->osb_truncate_log_wq,
6339                           ocfs2_truncate_log_worker);
6340         atomic_set(&osb->osb_tl_disable, 0);
6341         osb->osb_tl_bh    = tl_bh;
6342         osb->osb_tl_inode = tl_inode;
6343 
6344         return status;
6345 }
6346 
6347 /*
6348  * Delayed de-allocation of suballocator blocks.
6349  *
6350  * Some sets of block de-allocations might involve multiple suballocator inodes.
6351  *
6352  * The locking for this can get extremely complicated, especially when
6353  * the suballocator inodes to delete from aren't known until deep
6354  * within an unrelated codepath.
6355  *
6356  * ocfs2_extent_block structures are a good example of this - an inode
6357  * btree could have been grown by any number of nodes each allocating
6358  * out of their own suballoc inode.
6359  *
6360  * These structures allow the delay of block de-allocation until a
6361  * later time, when locking of multiple cluster inodes won't cause
6362  * deadlock.
6363  */
6364 
6365 /*
6366  * Describe a single bit freed from a suballocator.  For the block
6367  * suballocators, it represents one block.  For the global cluster
6368  * allocator, it represents some clusters and free_bit indicates
6369  * clusters number.
6370  */
6371 struct ocfs2_cached_block_free {
6372         struct ocfs2_cached_block_free          *free_next;
6373         u64                                     free_bg;
6374         u64                                     free_blk;
6375         unsigned int                            free_bit;
6376 };
6377 
6378 struct ocfs2_per_slot_free_list {
6379         struct ocfs2_per_slot_free_list         *f_next_suballocator;
6380         int                                     f_inode_type;
6381         int                                     f_slot;
6382         struct ocfs2_cached_block_free          *f_first;
6383 };
6384 
6385 static int ocfs2_free_cached_blocks(struct ocfs2_super *osb,
6386                                     int sysfile_type,
6387                                     int slot,
6388                                     struct ocfs2_cached_block_free *head)
6389 {
6390         int ret;
6391         u64 bg_blkno;
6392         handle_t *handle;
6393         struct inode *inode;
6394         struct buffer_head *di_bh = NULL;
6395         struct ocfs2_cached_block_free *tmp;
6396 
6397         inode = ocfs2_get_system_file_inode(osb, sysfile_type, slot);
6398         if (!inode) {
6399                 ret = -EINVAL;
6400                 mlog_errno(ret);
6401                 goto out;
6402         }
6403 
6404         inode_lock(inode);
6405 
6406         ret = ocfs2_inode_lock(inode, &di_bh, 1);
6407         if (ret) {
6408                 mlog_errno(ret);
6409                 goto out_mutex;
6410         }
6411 
6412         while (head) {
6413                 if (head->free_bg)
6414                         bg_blkno = head->free_bg;
6415                 else
6416                         bg_blkno = ocfs2_which_suballoc_group(head->free_blk,
6417                                                               head->free_bit);
6418                 handle = ocfs2_start_trans(osb, OCFS2_SUBALLOC_FREE);
6419                 if (IS_ERR(handle)) {
6420                         ret = PTR_ERR(handle);
6421                         mlog_errno(ret);
6422                         goto out_unlock;
6423                 }
6424 
6425                 trace_ocfs2_free_cached_blocks(
6426                      (unsigned long long)head->free_blk, head->free_bit);
6427 
6428                 ret = ocfs2_free_suballoc_bits(handle, inode, di_bh,
6429                                                head->free_bit, bg_blkno, 1);
6430                 if (ret)
6431                         mlog_errno(ret);
6432 
6433                 ocfs2_commit_trans(osb, handle);
6434 
6435                 tmp = head;
6436                 head = head->free_next;
6437                 kfree(tmp);
6438         }
6439 
6440 out_unlock:
6441         ocfs2_inode_unlock(inode, 1);
6442         brelse(di_bh);
6443 out_mutex:
6444         inode_unlock(inode);
6445         iput(inode);
6446 out:
6447         while(head) {
6448                 /* Premature exit may have left some dangling items. */
6449                 tmp = head;
6450                 head = head->free_next;
6451                 kfree(tmp);
6452         }
6453 
6454         return ret;
6455 }
6456 
6457 int ocfs2_cache_cluster_dealloc(struct ocfs2_cached_dealloc_ctxt *ctxt,
6458                                 u64 blkno, unsigned int bit)
6459 {
6460         int ret = 0;
6461         struct ocfs2_cached_block_free *item;
6462 
6463         item = kzalloc(sizeof(*item), GFP_NOFS);
6464         if (item == NULL) {
6465                 ret = -ENOMEM;
6466                 mlog_errno(ret);
6467                 return ret;
6468         }
6469 
6470         trace_ocfs2_cache_cluster_dealloc((unsigned long long)blkno, bit);
6471 
6472         item->free_blk = blkno;
6473         item->free_bit = bit;
6474         item->free_next = ctxt->c_global_allocator;
6475 
6476         ctxt->c_global_allocator = item;
6477         return ret;
6478 }
6479 
6480 static int ocfs2_free_cached_clusters(struct ocfs2_super *osb,
6481                                       struct ocfs2_cached_block_free *head)
6482 {
6483         struct ocfs2_cached_block_free *tmp;
6484         struct inode *tl_inode = osb->osb_tl_inode;
6485         handle_t *handle;
6486         int ret = 0;
6487 
6488         inode_lock(tl_inode);
6489 
6490         while (head) {
6491                 if (ocfs2_truncate_log_needs_flush(osb)) {
6492                         ret = __ocfs2_flush_truncate_log(osb);
6493                         if (ret < 0) {
6494                                 mlog_errno(ret);
6495                                 break;
6496                         }
6497                 }
6498 
6499                 handle = ocfs2_start_trans(osb, OCFS2_TRUNCATE_LOG_UPDATE);
6500                 if (IS_ERR(handle)) {
6501                         ret = PTR_ERR(handle);
6502                         mlog_errno(ret);
6503                         break;
6504                 }
6505 
6506                 ret = ocfs2_truncate_log_append(osb, handle, head->free_blk,
6507                                                 head->free_bit);
6508 
6509                 ocfs2_commit_trans(osb, handle);
6510                 tmp = head;
6511                 head = head->free_next;
6512                 kfree(tmp);
6513 
6514                 if (ret < 0) {
6515                         mlog_errno(ret);
6516                         break;
6517                 }
6518         }
6519 
6520         inode_unlock(tl_inode);
6521 
6522         while (head) {
6523                 /* Premature exit may have left some dangling items. */
6524                 tmp = head;
6525                 head = head->free_next;
6526                 kfree(tmp);
6527         }
6528 
6529         return ret;
6530 }
6531 
6532 int ocfs2_run_deallocs(struct ocfs2_super *osb,
6533                        struct ocfs2_cached_dealloc_ctxt *ctxt)
6534 {
6535         int ret = 0, ret2;
6536         struct ocfs2_per_slot_free_list *fl;
6537 
6538         if (!ctxt)
6539                 return 0;
6540 
6541         while (ctxt->c_first_suballocator) {
6542                 fl = ctxt->c_first_suballocator;
6543 
6544                 if (fl->f_first) {
6545                         trace_ocfs2_run_deallocs(fl->f_inode_type,
6546                                                  fl->f_slot);
6547                         ret2 = ocfs2_free_cached_blocks(osb,
6548                                                         fl->f_inode_type,
6549                                                         fl->f_slot,
6550                                                         fl->f_first);
6551                         if (ret2)
6552                                 mlog_errno(ret2);
6553                         if (!ret)
6554                                 ret = ret2;
6555                 }
6556 
6557                 ctxt->c_first_suballocator = fl->f_next_suballocator;
6558                 kfree(fl);
6559         }
6560 
6561         if (ctxt->c_global_allocator) {
6562                 ret2 = ocfs2_free_cached_clusters(osb,
6563                                                   ctxt->c_global_allocator);
6564                 if (ret2)
6565                         mlog_errno(ret2);
6566                 if (!ret)
6567                         ret = ret2;
6568 
6569                 ctxt->c_global_allocator = NULL;
6570         }
6571 
6572         return ret;
6573 }
6574 
6575 static struct ocfs2_per_slot_free_list *
6576 ocfs2_find_per_slot_free_list(int type,
6577                               int slot,
6578                               struct ocfs2_cached_dealloc_ctxt *ctxt)
6579 {
6580         struct ocfs2_per_slot_free_list *fl = ctxt->c_first_suballocator;
6581 
6582         while (fl) {
6583                 if (fl->f_inode_type == type && fl->f_slot == slot)
6584                         return fl;
6585 
6586                 fl = fl->f_next_suballocator;
6587         }
6588 
6589         fl = kmalloc(sizeof(*fl), GFP_NOFS);
6590         if (fl) {
6591                 fl->f_inode_type = type;
6592                 fl->f_slot = slot;
6593                 fl->f_first = NULL;
6594                 fl->f_next_suballocator = ctxt->c_first_suballocator;
6595 
6596                 ctxt->c_first_suballocator = fl;
6597         }
6598         return fl;
6599 }
6600 
6601 static struct ocfs2_per_slot_free_list *
6602 ocfs2_find_preferred_free_list(int type,
6603                                int preferred_slot,
6604                                int *real_slot,
6605                                struct ocfs2_cached_dealloc_ctxt *ctxt)
6606 {
6607         struct ocfs2_per_slot_free_list *fl = ctxt->c_first_suballocator;
6608 
6609         while (fl) {
6610                 if (fl->f_inode_type == type && fl->f_slot == preferred_slot) {
6611                         *real_slot = fl->f_slot;
6612                         return fl;
6613                 }
6614 
6615                 fl = fl->f_next_suballocator;
6616         }
6617 
6618         /* If we can't find any free list matching preferred slot, just use
6619          * the first one.
6620          */
6621         fl = ctxt->c_first_suballocator;
6622         *real_slot = fl->f_slot;
6623 
6624         return fl;
6625 }
6626 
6627 /* Return Value 1 indicates empty */
6628 static int ocfs2_is_dealloc_empty(struct ocfs2_extent_tree *et)
6629 {
6630         struct ocfs2_per_slot_free_list *fl = NULL;
6631 
6632         if (!et->et_dealloc)
6633                 return 1;
6634 
6635         fl = et->et_dealloc->c_first_suballocator;
6636         if (!fl)
6637                 return 1;
6638 
6639         if (!fl->f_first)
6640                 return 1;
6641 
6642         return 0;
6643 }
6644 
6645 /* If extent was deleted from tree due to extent rotation and merging, and
6646  * no metadata is reserved ahead of time. Try to reuse some extents
6647  * just deleted. This is only used to reuse extent blocks.
6648  * It is supposed to find enough extent blocks in dealloc if our estimation
6649  * on metadata is accurate.
6650  */
6651 static int ocfs2_reuse_blk_from_dealloc(handle_t *handle,
6652                                         struct ocfs2_extent_tree *et,
6653                                         struct buffer_head **new_eb_bh,
6654                                         int blk_wanted, int *blk_given)
6655 {
6656         int i, status = 0, real_slot;
6657         struct ocfs2_cached_dealloc_ctxt *dealloc;
6658         struct ocfs2_per_slot_free_list *fl;
6659         struct ocfs2_cached_block_free *bf;
6660         struct ocfs2_extent_block *eb;
6661         struct ocfs2_super *osb =
6662                 OCFS2_SB(ocfs2_metadata_cache_get_super(et->et_ci));
6663 
6664         *blk_given = 0;
6665 
6666         /* If extent tree doesn't have a dealloc, this is not faulty. Just
6667          * tell upper caller dealloc can't provide any block and it should
6668          * ask for alloc to claim more space.
6669          */
6670         dealloc = et->et_dealloc;
6671         if (!dealloc)
6672                 goto bail;
6673 
6674         for (i = 0; i < blk_wanted; i++) {
6675                 /* Prefer to use local slot */
6676                 fl = ocfs2_find_preferred_free_list(EXTENT_ALLOC_SYSTEM_INODE,
6677                                                     osb->slot_num, &real_slot,
6678                                                     dealloc);
6679                 /* If no more block can be reused, we should claim more
6680                  * from alloc. Just return here normally.
6681                  */
6682                 if (!fl) {
6683                         status = 0;
6684                         break;
6685                 }
6686 
6687                 bf = fl->f_first;
6688                 fl->f_first = bf->free_next;
6689 
6690                 new_eb_bh[i] = sb_getblk(osb->sb, bf->free_blk);
6691                 if (new_eb_bh[i] == NULL) {
6692                         status = -ENOMEM;
6693                         mlog_errno(status);
6694                         goto bail;
6695                 }
6696 
6697                 mlog(0, "Reusing block(%llu) from "
6698                      "dealloc(local slot:%d, real slot:%d)\n",
6699                      bf->free_blk, osb->slot_num, real_slot);
6700 
6701                 ocfs2_set_new_buffer_uptodate(et->et_ci, new_eb_bh[i]);
6702 
6703                 status = ocfs2_journal_access_eb(handle, et->et_ci,
6704                                                  new_eb_bh[i],
6705                                                  OCFS2_JOURNAL_ACCESS_CREATE);
6706                 if (status < 0) {
6707                         mlog_errno(status);
6708                         goto bail;
6709                 }
6710 
6711                 memset(new_eb_bh[i]->b_data, 0, osb->sb->s_blocksize);
6712                 eb = (struct ocfs2_extent_block *) new_eb_bh[i]->b_data;
6713 
6714                 /* We can't guarantee that buffer head is still cached, so
6715                  * polutlate the extent block again.
6716                  */
6717                 strcpy(eb->h_signature, OCFS2_EXTENT_BLOCK_SIGNATURE);
6718                 eb->h_blkno = cpu_to_le64(bf->free_blk);
6719                 eb->h_fs_generation = cpu_to_le32(osb->fs_generation);
6720                 eb->h_suballoc_slot = cpu_to_le16(real_slot);
6721                 eb->h_suballoc_loc = cpu_to_le64(bf->free_bg);
6722                 eb->h_suballoc_bit = cpu_to_le16(bf->free_bit);
6723                 eb->h_list.l_count =
6724                         cpu_to_le16(ocfs2_extent_recs_per_eb(osb->sb));
6725 
6726                 /* We'll also be dirtied by the caller, so
6727                  * this isn't absolutely necessary.
6728                  */
6729                 ocfs2_journal_dirty(handle, new_eb_bh[i]);
6730 
6731                 if (!fl->f_first) {
6732                         dealloc->c_first_suballocator = fl->f_next_suballocator;
6733                         kfree(fl);
6734                 }
6735                 kfree(bf);
6736         }
6737 
6738         *blk_given = i;
6739 
6740 bail:
6741         if (unlikely(status < 0)) {
6742                 for (i = 0; i < blk_wanted; i++)
6743                         brelse(new_eb_bh[i]);
6744         }
6745 
6746         return status;
6747 }
6748 
6749 int ocfs2_cache_block_dealloc(struct ocfs2_cached_dealloc_ctxt *ctxt,
6750                               int type, int slot, u64 suballoc,
6751                               u64 blkno, unsigned int bit)
6752 {
6753         int ret;
6754         struct ocfs2_per_slot_free_list *fl;
6755         struct ocfs2_cached_block_free *item;
6756 
6757         fl = ocfs2_find_per_slot_free_list(type, slot, ctxt);
6758         if (fl == NULL) {
6759                 ret = -ENOMEM;
6760                 mlog_errno(ret);
6761                 goto out;
6762         }
6763 
6764         item = kzalloc(sizeof(*item), GFP_NOFS);
6765         if (item == NULL) {
6766                 ret = -ENOMEM;
6767                 mlog_errno(ret);
6768                 goto out;
6769         }
6770 
6771         trace_ocfs2_cache_block_dealloc(type, slot,
6772                                         (unsigned long long)suballoc,
6773                                         (unsigned long long)blkno, bit);
6774 
6775         item->free_bg = suballoc;
6776         item->free_blk = blkno;
6777         item->free_bit = bit;
6778         item->free_next = fl->f_first;
6779 
6780         fl->f_first = item;
6781 
6782         ret = 0;
6783 out:
6784         return ret;
6785 }
6786 
6787 static int ocfs2_cache_extent_block_free(struct ocfs2_cached_dealloc_ctxt *ctxt,
6788                                          struct ocfs2_extent_block *eb)
6789 {
6790         return ocfs2_cache_block_dealloc(ctxt, EXTENT_ALLOC_SYSTEM_INODE,
6791                                          le16_to_cpu(eb->h_suballoc_slot),
6792                                          le64_to_cpu(eb->h_suballoc_loc),
6793                                          le64_to_cpu(eb->h_blkno),
6794                                          le16_to_cpu(eb->h_suballoc_bit));
6795 }
6796 
6797 static int ocfs2_zero_func(handle_t *handle, struct buffer_head *bh)
6798 {
6799         set_buffer_uptodate(bh);
6800         mark_buffer_dirty(bh);
6801         return 0;
6802 }
6803 
6804 void ocfs2_map_and_dirty_page(struct inode *inode, handle_t *handle,
6805                               unsigned int from, unsigned int to,
6806                               struct page *page, int zero, u64 *phys)
6807 {
6808         int ret, partial = 0;
6809 
6810         ret = ocfs2_map_page_blocks(page, phys, inode, from, to, 0);
6811         if (ret)
6812                 mlog_errno(ret);
6813 
6814         if (zero)
6815                 zero_user_segment(page, from, to);
6816 
6817         /*
6818          * Need to set the buffers we zero'd into uptodate
6819          * here if they aren't - ocfs2_map_page_blocks()
6820          * might've skipped some
6821          */
6822         ret = walk_page_buffers(handle, page_buffers(page),
6823                                 from, to, &partial,
6824                                 ocfs2_zero_func);
6825         if (ret < 0)
6826                 mlog_errno(ret);
6827         else if (ocfs2_should_order_data(inode)) {
6828                 ret = ocfs2_jbd2_file_inode(handle, inode);
6829                 if (ret < 0)
6830                         mlog_errno(ret);
6831         }
6832 
6833         if (!partial)
6834                 SetPageUptodate(page);
6835 
6836         flush_dcache_page(page);
6837 }
6838 
6839 static void ocfs2_zero_cluster_pages(struct inode *inode, loff_t start,
6840                                      loff_t end, struct page **pages,
6841                                      int numpages, u64 phys, handle_t *handle)
6842 {
6843         int i;
6844         struct page *page;
6845         unsigned int from, to = PAGE_SIZE;
6846         struct super_block *sb = inode->i_sb;
6847 
6848         BUG_ON(!ocfs2_sparse_alloc(OCFS2_SB(sb)));
6849 
6850         if (numpages == 0)
6851                 goto out;
6852 
6853         to = PAGE_SIZE;
6854         for(i = 0; i < numpages; i++) {
6855                 page = pages[i];
6856 
6857                 from = start & (PAGE_SIZE - 1);
6858                 if ((end >> PAGE_SHIFT) == page->index)
6859                         to = end & (PAGE_SIZE - 1);
6860 
6861                 BUG_ON(from > PAGE_SIZE);
6862                 BUG_ON(to > PAGE_SIZE);
6863 
6864                 ocfs2_map_and_dirty_page(inode, handle, from, to, page, 1,
6865                                          &phys);
6866 
6867                 start = (page->index + 1) << PAGE_SHIFT;
6868         }
6869 out:
6870         if (pages)
6871                 ocfs2_unlock_and_free_pages(pages, numpages);
6872 }
6873 
6874 int ocfs2_grab_pages(struct inode *inode, loff_t start, loff_t end,
6875                      struct page **pages, int *num)
6876 {
6877         int numpages, ret = 0;
6878         struct address_space *mapping = inode->i_mapping;
6879         unsigned long index;
6880         loff_t last_page_bytes;
6881 
6882         BUG_ON(start > end);
6883 
6884         numpages = 0;
6885         last_page_bytes = PAGE_ALIGN(end);
6886         index = start >> PAGE_SHIFT;
6887         do {
6888                 pages[numpages] = find_or_create_page(mapping, index, GFP_NOFS);
6889                 if (!pages[numpages]) {
6890                         ret = -ENOMEM;
6891                         mlog_errno(ret);
6892                         goto out;
6893                 }
6894 
6895                 numpages++;
6896                 index++;
6897         } while (index < (last_page_bytes >> PAGE_SHIFT));
6898 
6899 out:
6900         if (ret != 0) {
6901                 if (pages)
6902                         ocfs2_unlock_and_free_pages(pages, numpages);
6903                 numpages = 0;
6904         }
6905 
6906         *num = numpages;
6907 
6908         return ret;
6909 }
6910 
6911 static int ocfs2_grab_eof_pages(struct inode *inode, loff_t start, loff_t end,
6912                                 struct page **pages, int *num)
6913 {
6914         struct super_block *sb = inode->i_sb;
6915 
6916         BUG_ON(start >> OCFS2_SB(sb)->s_clustersize_bits !=
6917                (end - 1) >> OCFS2_SB(sb)->s_clustersize_bits);
6918 
6919         return ocfs2_grab_pages(inode, start, end, pages, num);
6920 }
6921 
6922 /*
6923  * Zero the area past i_size but still within an allocated
6924  * cluster. This avoids exposing nonzero data on subsequent file
6925  * extends.
6926  *
6927  * We need to call this before i_size is updated on the inode because
6928  * otherwise block_write_full_page() will skip writeout of pages past
6929  * i_size. The new_i_size parameter is passed for this reason.
6930  */
6931 int ocfs2_zero_range_for_truncate(struct inode *inode, handle_t *handle,
6932                                   u64 range_start, u64 range_end)
6933 {
6934         int ret = 0, numpages;
6935         struct page **pages = NULL;
6936         u64 phys;
6937         unsigned int ext_flags;
6938         struct super_block *sb = inode->i_sb;
6939 
6940         /*
6941          * File systems which don't support sparse files zero on every
6942          * extend.
6943          */
6944         if (!ocfs2_sparse_alloc(OCFS2_SB(sb)))
6945                 return 0;
6946 
6947         pages = kcalloc(ocfs2_pages_per_cluster(sb),
6948                         sizeof(struct page *), GFP_NOFS);
6949         if (pages == NULL) {
6950                 ret = -ENOMEM;
6951                 mlog_errno(ret);
6952                 goto out;
6953         }
6954 
6955         if (range_start == range_end)
6956                 goto out;
6957 
6958         ret = ocfs2_extent_map_get_blocks(inode,
6959                                           range_start >> sb->s_blocksize_bits,
6960                                           &phys, NULL, &ext_flags);
6961         if (ret) {
6962                 mlog_errno(ret);
6963                 goto out;
6964         }
6965 
6966         /*
6967          * Tail is a hole, or is marked unwritten. In either case, we
6968          * can count on read and write to return/push zero's.
6969          */
6970         if (phys == 0 || ext_flags & OCFS2_EXT_UNWRITTEN)
6971                 goto out;
6972 
6973         ret = ocfs2_grab_eof_pages(inode, range_start, range_end, pages,
6974                                    &numpages);
6975         if (ret) {
6976                 mlog_errno(ret);
6977                 goto out;
6978         }
6979 
6980         ocfs2_zero_cluster_pages(inode, range_start, range_end, pages,
6981                                  numpages, phys, handle);
6982 
6983         /*
6984          * Initiate writeout of the pages we zero'd here. We don't
6985          * wait on them - the truncate_inode_pages() call later will
6986          * do that for us.
6987          */
6988         ret = filemap_fdatawrite_range(inode->i_mapping, range_start,
6989                                        range_end - 1);
6990         if (ret)
6991                 mlog_errno(ret);
6992 
6993 out:
6994         kfree(pages);
6995 
6996         return ret;
6997 }
6998 
6999 static void ocfs2_zero_dinode_id2_with_xattr(struct inode *inode,
7000                                              struct ocfs2_dinode *di)
7001 {
7002         unsigned int blocksize = 1 << inode->i_sb->s_blocksize_bits;
7003         unsigned int xattrsize = le16_to_cpu(di->i_xattr_inline_size);
7004 
7005         if (le16_to_cpu(di->i_dyn_features) & OCFS2_INLINE_XATTR_FL)
7006                 memset(&di->id2, 0, blocksize -
7007                                     offsetof(struct ocfs2_dinode, id2) -
7008                                     xattrsize);
7009         else
7010                 memset(&di->id2, 0, blocksize -
7011                                     offsetof(struct ocfs2_dinode, id2));
7012 }
7013 
7014 void ocfs2_dinode_new_extent_list(struct inode *inode,
7015                                   struct ocfs2_dinode *di)
7016 {
7017         ocfs2_zero_dinode_id2_with_xattr(inode, di);
7018         di->id2.i_list.l_tree_depth = 0;
7019         di->id2.i_list.l_next_free_rec = 0;
7020         di->id2.i_list.l_count = cpu_to_le16(
7021                 ocfs2_extent_recs_per_inode_with_xattr(inode->i_sb, di));
7022 }
7023 
7024 void ocfs2_set_inode_data_inline(struct inode *inode, struct ocfs2_dinode *di)
7025 {
7026         struct ocfs2_inode_info *oi = OCFS2_I(inode);
7027         struct ocfs2_inline_data *idata = &di->id2.i_data;
7028 
7029         spin_lock(&oi->ip_lock);
7030         oi->ip_dyn_features |= OCFS2_INLINE_DATA_FL;
7031         di->i_dyn_features = cpu_to_le16(oi->ip_dyn_features);
7032         spin_unlock(&oi->ip_lock);
7033 
7034         /*
7035          * We clear the entire i_data structure here so that all
7036          * fields can be properly initialized.
7037          */
7038         ocfs2_zero_dinode_id2_with_xattr(inode, di);
7039 
7040         idata->id_count = cpu_to_le16(
7041                         ocfs2_max_inline_data_with_xattr(inode->i_sb, di));
7042 }
7043 
7044 int ocfs2_convert_inline_data_to_extents(struct inode *inode,
7045                                          struct buffer_head *di_bh)
7046 {
7047         int ret, i, has_data, num_pages = 0;
7048         int need_free = 0;
7049         u32 bit_off, num;
7050         handle_t *handle;
7051         u64 uninitialized_var(block);
7052         struct ocfs2_inode_info *oi = OCFS2_I(inode);
7053         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
7054         struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
7055         struct ocfs2_alloc_context *data_ac = NULL;
7056         struct page **pages = NULL;
7057         loff_t end = osb->s_clustersize;
7058         struct ocfs2_extent_tree et;
7059         int did_quota = 0;
7060 
7061         has_data = i_size_read(inode) ? 1 : 0;
7062 
7063         if (has_data) {
7064                 pages = kcalloc(ocfs2_pages_per_cluster(osb->sb),
7065                                 sizeof(struct page *), GFP_NOFS);
7066                 if (pages == NULL) {
7067                         ret = -ENOMEM;
7068                         mlog_errno(ret);
7069                         return ret;
7070                 }
7071 
7072                 ret = ocfs2_reserve_clusters(osb, 1, &data_ac);
7073                 if (ret) {
7074                         mlog_errno(ret);
7075                         goto free_pages;
7076                 }
7077         }
7078 
7079         handle = ocfs2_start_trans(osb,
7080                                    ocfs2_inline_to_extents_credits(osb->sb));
7081         if (IS_ERR(handle)) {
7082                 ret = PTR_ERR(handle);
7083                 mlog_errno(ret);
7084                 goto out;
7085         }
7086 
7087         ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), di_bh,
7088                                       OCFS2_JOURNAL_ACCESS_WRITE);
7089         if (ret) {
7090                 mlog_errno(ret);
7091                 goto out_commit;
7092         }
7093 
7094         if (has_data) {
7095                 unsigned int page_end;
7096                 u64 phys;
7097 
7098                 ret = dquot_alloc_space_nodirty(inode,
7099                                        ocfs2_clusters_to_bytes(osb->sb, 1));
7100                 if (ret)
7101                         goto out_commit;
7102                 did_quota = 1;
7103 
7104                 data_ac->ac_resv = &oi->ip_la_data_resv;
7105 
7106                 ret = ocfs2_claim_clusters(handle, data_ac, 1, &bit_off,
7107                                            &num);
7108                 if (ret) {
7109                         mlog_errno(ret);
7110                         goto out_commit;
7111                 }
7112 
7113                 /*
7114                  * Save two copies, one for insert, and one that can
7115                  * be changed by ocfs2_map_and_dirty_page() below.
7116                  */
7117                 block = phys = ocfs2_clusters_to_blocks(inode->i_sb, bit_off);
7118 
7119                 /*
7120                  * Non sparse file systems zero on extend, so no need
7121                  * to do that now.
7122                  */
7123                 if (!ocfs2_sparse_alloc(osb) &&
7124                     PAGE_SIZE < osb->s_clustersize)
7125                         end = PAGE_SIZE;
7126 
7127                 ret = ocfs2_grab_eof_pages(inode, 0, end, pages, &num_pages);
7128                 if (ret) {
7129                         mlog_errno(ret);
7130                         need_free = 1;
7131                         goto out_commit;
7132                 }
7133 
7134                 /*
7135                  * This should populate the 1st page for us and mark
7136                  * it up to date.
7137                  */
7138                 ret = ocfs2_read_inline_data(inode, pages[0], di_bh);
7139                 if (ret) {
7140                         mlog_errno(ret);
7141                         need_free = 1;
7142                         goto out_unlock;
7143                 }
7144 
7145                 page_end = PAGE_SIZE;
7146                 if (PAGE_SIZE > osb->s_clustersize)
7147                         page_end = osb->s_clustersize;
7148 
7149                 for (i = 0; i < num_pages; i++)
7150                         ocfs2_map_and_dirty_page(inode, handle, 0, page_end,
7151                                                  pages[i], i > 0, &phys);
7152         }
7153 
7154         spin_lock(&oi->ip_lock);
7155         oi->ip_dyn_features &= ~OCFS2_INLINE_DATA_FL;
7156         di->i_dyn_features = cpu_to_le16(oi->ip_dyn_features);
7157         spin_unlock(&oi->ip_lock);
7158 
7159         ocfs2_update_inode_fsync_trans(handle, inode, 1);
7160         ocfs2_dinode_new_extent_list(inode, di);
7161 
7162         ocfs2_journal_dirty(handle, di_bh);
7163 
7164         if (has_data) {
7165                 /*
7166                  * An error at this point should be extremely rare. If
7167                  * this proves to be false, we could always re-build
7168                  * the in-inode data from our pages.
7169                  */
7170                 ocfs2_init_dinode_extent_tree(&et, INODE_CACHE(inode), di_bh);
7171                 ret = ocfs2_insert_extent(handle, &et, 0, block, 1, 0, NULL);
7172                 if (ret) {
7173                         mlog_errno(ret);
7174                         need_free = 1;
7175                         goto out_unlock;
7176                 }
7177 
7178                 inode->i_blocks = ocfs2_inode_sector_count(inode);
7179         }
7180 
7181 out_unlock:
7182         if (pages)
7183                 ocfs2_unlock_and_free_pages(pages, num_pages);
7184 
7185 out_commit:
7186         if (ret < 0 && did_quota)
7187                 dquot_free_space_nodirty(inode,
7188                                           ocfs2_clusters_to_bytes(osb->sb, 1));
7189 
7190         if (need_free) {
7191                 if (data_ac->ac_which == OCFS2_AC_USE_LOCAL)
7192                         ocfs2_free_local_alloc_bits(osb, handle, data_ac,
7193                                         bit_off, num);
7194                 else
7195                         ocfs2_free_clusters(handle,
7196                                         data_ac->ac_inode,
7197                                         data_ac->ac_bh,
7198                                         ocfs2_clusters_to_blocks(osb->sb, bit_off),
7199                                         num);
7200         }
7201 
7202         ocfs2_commit_trans(osb, handle);
7203 
7204 out:
7205         if (data_ac)
7206                 ocfs2_free_alloc_context(data_ac);
7207 free_pages:
7208         kfree(pages);
7209         return ret;
7210 }
7211 
7212 /*
7213  * It is expected, that by the time you call this function,
7214  * inode->i_size and fe->i_size have been adjusted.
7215  *
7216  * WARNING: This will kfree the truncate context
7217  */
7218 int ocfs2_commit_truncate(struct ocfs2_super *osb,
7219                           struct inode *inode,
7220                           struct buffer_head *di_bh)
7221 {
7222         int status = 0, i, flags = 0;
7223         u32 new_highest_cpos, range, trunc_cpos, trunc_len, phys_cpos, coff;
7224         u64 blkno = 0;
7225         struct ocfs2_extent_list *el;
7226         struct ocfs2_extent_rec *rec;
7227         struct ocfs2_path *path = NULL;
7228         struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
7229         struct ocfs2_extent_list *root_el = &(di->id2.i_list);
7230         u64 refcount_loc = le64_to_cpu(di->i_refcount_loc);
7231         struct ocfs2_extent_tree et;
7232         struct ocfs2_cached_dealloc_ctxt dealloc;
7233         struct ocfs2_refcount_tree *ref_tree = NULL;
7234 
7235         ocfs2_init_dinode_extent_tree(&et, INODE_CACHE(inode), di_bh);
7236         ocfs2_init_dealloc_ctxt(&dealloc);
7237 
7238         new_highest_cpos = ocfs2_clusters_for_bytes(osb->sb,
7239                                                      i_size_read(inode));
7240 
7241         path = ocfs2_new_path(di_bh, &di->id2.i_list,
7242                               ocfs2_journal_access_di);
7243         if (!path) {
7244                 status = -ENOMEM;
7245                 mlog_errno(status);
7246                 goto bail;
7247         }
7248 
7249         ocfs2_extent_map_trunc(inode, new_highest_cpos);
7250 
7251 start:
7252         /*
7253          * Check that we still have allocation to delete.
7254          */
7255         if (OCFS2_I(inode)->ip_clusters == 0) {
7256                 status = 0;
7257                 goto bail;
7258         }
7259 
7260         /*
7261          * Truncate always works against the rightmost tree branch.
7262          */
7263         status = ocfs2_find_path(INODE_CACHE(inode), path, UINT_MAX);
7264         if (status) {
7265                 mlog_errno(status);
7266                 goto bail;
7267         }
7268 
7269         trace_ocfs2_commit_truncate(
7270                 (unsigned long long)OCFS2_I(inode)->ip_blkno,
7271                 new_highest_cpos,
7272                 OCFS2_I(inode)->ip_clusters,
7273                 path->p_tree_depth);
7274 
7275         /*
7276          * By now, el will point to the extent list on the bottom most
7277          * portion of this tree. Only the tail record is considered in
7278          * each pass.
7279          *
7280          * We handle the following cases, in order:
7281          * - empty extent: delete the remaining branch
7282          * - remove the entire record
7283          * - remove a partial record
7284          * - no record needs to be removed (truncate has completed)
7285          */
7286         el = path_leaf_el(path);
7287         if (le16_to_cpu(el->l_next_free_rec) == 0) {
7288                 ocfs2_error(inode->i_sb,
7289                             "Inode %llu has empty extent block at %llu\n",
7290                             (unsigned long long)OCFS2_I(inode)->ip_blkno,
7291                             (unsigned long long)path_leaf_bh(path)->b_blocknr);
7292                 status = -EROFS;
7293                 goto bail;
7294         }
7295 
7296         i = le16_to_cpu(el->l_next_free_rec) - 1;
7297         rec = &el->l_recs[i];
7298         flags = rec->e_flags;
7299         range = le32_to_cpu(rec->e_cpos) + ocfs2_rec_clusters(el, rec);
7300 
7301         if (i == 0 && ocfs2_is_empty_extent(rec)) {
7302                 /*
7303                  * Lower levels depend on this never happening, but it's best
7304                  * to check it up here before changing the tree.
7305                 */
7306                 if (root_el->l_tree_depth && rec->e_int_clusters == 0) {
7307                         mlog(ML_ERROR, "Inode %lu has an empty "
7308                                     "extent record, depth %u\n", inode->i_ino,
7309                                     le16_to_cpu(root_el->l_tree_depth));
7310                         status = ocfs2_remove_rightmost_empty_extent(osb,
7311                                         &et, path, &dealloc);
7312                         if (status) {
7313                                 mlog_errno(status);
7314                                 goto bail;
7315                         }
7316 
7317                         ocfs2_reinit_path(path, 1);
7318                         goto start;
7319                 } else {
7320                         trunc_cpos = le32_to_cpu(rec->e_cpos);
7321                         trunc_len = 0;
7322                         blkno = 0;
7323                 }
7324         } else if (le32_to_cpu(rec->e_cpos) >= new_highest_cpos) {
7325                 /*
7326                  * Truncate entire record.
7327                  */
7328                 trunc_cpos = le32_to_cpu(rec->e_cpos);
7329                 trunc_len = ocfs2_rec_clusters(el, rec);
7330                 blkno = le64_to_cpu(rec->e_blkno);
7331         } else if (range > new_highest_cpos) {
7332                 /*
7333                  * Partial truncate. it also should be
7334                  * the last truncate we're doing.
7335                  */
7336                 trunc_cpos = new_highest_cpos;
7337                 trunc_len = range - new_highest_cpos;
7338                 coff = new_highest_cpos - le32_to_cpu(rec->e_cpos);
7339                 blkno = le64_to_cpu(rec->e_blkno) +
7340                                 ocfs2_clusters_to_blocks(inode->i_sb, coff);
7341         } else {
7342                 /*
7343                  * Truncate completed, leave happily.
7344                  */
7345                 status = 0;
7346                 goto bail;
7347         }
7348 
7349         phys_cpos = ocfs2_blocks_to_clusters(inode->i_sb, blkno);
7350 
7351         if ((flags & OCFS2_EXT_REFCOUNTED) && trunc_len && !ref_tree) {
7352                 status = ocfs2_lock_refcount_tree(osb, refcount_loc, 1,
7353                                 &ref_tree, NULL);
7354                 if (status) {
7355                         mlog_errno(status);
7356                         goto bail;
7357                 }
7358         }
7359 
7360         status = ocfs2_remove_btree_range(inode, &et, trunc_cpos,
7361                                           phys_cpos, trunc_len, flags, &dealloc,
7362                                           refcount_loc, true);
7363         if (status < 0) {
7364                 mlog_errno(status);
7365                 goto bail;
7366         }
7367 
7368         ocfs2_reinit_path(path, 1);
7369 
7370         /*
7371          * The check above will catch the case where we've truncated
7372          * away all allocation.
7373          */
7374         goto start;
7375 
7376 bail:
7377         if (ref_tree)
7378                 ocfs2_unlock_refcount_tree(osb, ref_tree, 1);
7379 
7380         ocfs2_schedule_truncate_log_flush(osb, 1);
7381 
7382         ocfs2_run_deallocs(osb, &dealloc);
7383 
7384         ocfs2_free_path(path);
7385 
7386         return status;
7387 }
7388 
7389 /*
7390  * 'start' is inclusive, 'end' is not.
7391  */
7392 int ocfs2_truncate_inline(struct inode *inode, struct buffer_head *di_bh,
7393                           unsigned int start, unsigned int end, int trunc)
7394 {
7395         int ret;
7396         unsigned int numbytes;
7397         handle_t *handle;
7398         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
7399         struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
7400         struct ocfs2_inline_data *idata = &di->id2.i_data;
7401 
7402         if (end > i_size_read(inode))
7403                 end = i_size_read(inode);
7404 
7405         BUG_ON(start > end);
7406 
7407         if (!(OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL) ||
7408             !(le16_to_cpu(di->i_dyn_features) & OCFS2_INLINE_DATA_FL) ||
7409             !ocfs2_supports_inline_data(osb)) {
7410                 ocfs2_error(inode->i_sb,
7411                             "Inline data flags for inode %llu don't agree! Disk: 0x%x, Memory: 0x%x, Superblock: 0x%x\n",
7412                             (unsigned long long)OCFS2_I(inode)->ip_blkno,
7413                             le16_to_cpu(di->i_dyn_features),
7414                             OCFS2_I(inode)->ip_dyn_features,
7415                             osb->s_feature_incompat);
7416                 ret = -EROFS;
7417                 goto out;
7418         }
7419 
7420         handle = ocfs2_start_trans(osb, OCFS2_INODE_UPDATE_CREDITS);
7421         if (IS_ERR(handle)) {
7422                 ret = PTR_ERR(handle);
7423                 mlog_errno(ret);
7424                 goto out;
7425         }
7426 
7427         ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), di_bh,
7428                                       OCFS2_JOURNAL_ACCESS_WRITE);
7429         if (ret) {
7430                 mlog_errno(ret);
7431                 goto out_commit;
7432         }
7433 
7434         numbytes = end - start;
7435         memset(idata->id_data + start, 0, numbytes);
7436 
7437         /*
7438          * No need to worry about the data page here - it's been
7439          * truncated already and inline data doesn't need it for
7440          * pushing zero's to disk, so we'll let readpage pick it up
7441          * later.
7442          */
7443         if (trunc) {
7444                 i_size_write(inode, start);
7445                 di->i_size = cpu_to_le64(start);
7446         }
7447 
7448         inode->i_blocks = ocfs2_inode_sector_count(inode);
7449         inode->i_ctime = inode->i_mtime = current_time(inode);
7450 
7451         di->i_ctime = di->i_mtime = cpu_to_le64(inode->i_ctime.tv_sec);
7452         di->i_ctime_nsec = di->i_mtime_nsec = cpu_to_le32(inode->i_ctime.tv_nsec);
7453 
7454         ocfs2_update_inode_fsync_trans(handle, inode, 1);
7455         ocfs2_journal_dirty(handle, di_bh);
7456 
7457 out_commit:
7458         ocfs2_commit_trans(osb, handle);
7459 
7460 out:
7461         return ret;
7462 }
7463 
7464 static int ocfs2_trim_extent(struct super_block *sb,
7465                              struct ocfs2_group_desc *gd,
7466                              u64 group, u32 start, u32 count)
7467 {
7468         u64 discard, bcount;
7469         struct ocfs2_super *osb = OCFS2_SB(sb);
7470 
7471         bcount = ocfs2_clusters_to_blocks(sb, count);
7472         discard = ocfs2_clusters_to_blocks(sb, start);
7473 
7474         /*
7475          * For the first cluster group, the gd->bg_blkno is not at the start
7476          * of the group, but at an offset from the start. If we add it while
7477          * calculating discard for first group, we will wrongly start fstrim a
7478          * few blocks after the desried start block and the range can cross
7479          * over into the next cluster group. So, add it only if this is not
7480          * the first cluster group.
7481          */
7482         if (group != osb->first_cluster_group_blkno)
7483                 discard += le64_to_cpu(gd->bg_blkno);
7484 
7485         trace_ocfs2_trim_extent(sb, (unsigned long long)discard, bcount);
7486 
7487         return sb_issue_discard(sb, discard, bcount, GFP_NOFS, 0);
7488 }
7489 
7490 static int ocfs2_trim_group(struct super_block *sb,
7491                             struct ocfs2_group_desc *gd, u64 group,
7492                             u32 start, u32 max, u32 minbits)
7493 {
7494         int ret = 0, count = 0, next;
7495         void *bitmap = gd->bg_bitmap;
7496 
7497         if (le16_to_cpu(gd->bg_free_bits_count) < minbits)
7498                 return 0;
7499 
7500         trace_ocfs2_trim_group((unsigned long long)le64_to_cpu(gd->bg_blkno),
7501                                start, max, minbits);
7502 
7503         while (start < max) {
7504                 start = ocfs2_find_next_zero_bit(bitmap, max, start);
7505                 if (start >= max)
7506                         break;
7507                 next = ocfs2_find_next_bit(bitmap, max, start);
7508 
7509                 if ((next - start) >= minbits) {
7510                         ret = ocfs2_trim_extent(sb, gd, group,
7511                                                 start, next - start);
7512                         if (ret < 0) {
7513                                 mlog_errno(ret);
7514                                 break;
7515                         }
7516                         count += next - start;
7517                 }
7518                 start = next + 1;
7519 
7520                 if (fatal_signal_pending(current)) {
7521                         count = -ERESTARTSYS;
7522                         break;
7523                 }
7524 
7525                 if ((le16_to_cpu(gd->bg_free_bits_count) - count) < minbits)
7526                         break;
7527         }
7528 
7529         if (ret < 0)
7530                 count = ret;
7531 
7532         return count;
7533 }
7534 
7535 int ocfs2_trim_fs(struct super_block *sb, struct fstrim_range *range)
7536 {
7537         struct ocfs2_super *osb = OCFS2_SB(sb);
7538         u64 start, len, trimmed, first_group, last_group, group;
7539         int ret, cnt;
7540         u32 first_bit, last_bit, minlen;
7541         struct buffer_head *main_bm_bh = NULL;
7542         struct inode *main_bm_inode = NULL;
7543         struct buffer_head *gd_bh = NULL;
7544         struct ocfs2_dinode *main_bm;
7545         struct ocfs2_group_desc *gd = NULL;
7546         struct ocfs2_trim_fs_info info, *pinfo = NULL;
7547 
7548         start = range->start >> osb->s_clustersize_bits;
7549         len = range->len >> osb->s_clustersize_bits;
7550         minlen = range->minlen >> osb->s_clustersize_bits;
7551 
7552         if (minlen >= osb->bitmap_cpg || range->len < sb->s_blocksize)
7553                 return -EINVAL;
7554 
7555         main_bm_inode = ocfs2_get_system_file_inode(osb,
7556                                                     GLOBAL_BITMAP_SYSTEM_INODE,
7557                                                     OCFS2_INVALID_SLOT);
7558         if (!main_bm_inode) {
7559                 ret = -EIO;
7560                 mlog_errno(ret);
7561                 goto out;
7562         }
7563 
7564         inode_lock(main_bm_inode);
7565 
7566         ret = ocfs2_inode_lock(main_bm_inode, &main_bm_bh, 0);
7567         if (ret < 0) {
7568                 mlog_errno(ret);
7569                 goto out_mutex;
7570         }
7571         main_bm = (struct ocfs2_dinode *)main_bm_bh->b_data;
7572 
7573         if (start >= le32_to_cpu(main_bm->i_clusters)) {
7574                 ret = -EINVAL;
7575                 goto out_unlock;
7576         }
7577 
7578         len = range->len >> osb->s_clustersize_bits;
7579         if (start + len > le32_to_cpu(main_bm->i_clusters))
7580                 len = le32_to_cpu(main_bm->i_clusters) - start;
7581 
7582         trace_ocfs2_trim_fs(start, len, minlen);
7583 
7584         ocfs2_trim_fs_lock_res_init(osb);
7585         ret = ocfs2_trim_fs_lock(osb, NULL, 1);
7586         if (ret < 0) {
7587                 if (ret != -EAGAIN) {
7588                         mlog_errno(ret);
7589                         ocfs2_trim_fs_lock_res_uninit(osb);
7590                         goto out_unlock;
7591                 }
7592 
7593                 mlog(ML_NOTICE, "Wait for trim on device (%s) to "
7594                      "finish, which is running from another node.\n",
7595                      osb->dev_str);
7596                 ret = ocfs2_trim_fs_lock(osb, &info, 0);
7597                 if (ret < 0) {
7598                         mlog_errno(ret);
7599                         ocfs2_trim_fs_lock_res_uninit(osb);
7600                         goto out_unlock;
7601                 }
7602 
7603                 if (info.tf_valid && info.tf_success &&
7604                     info.tf_start == start && info.tf_len == len &&
7605                     info.tf_minlen == minlen) {
7606                         /* Avoid sending duplicated trim to a shared device */
7607                         mlog(ML_NOTICE, "The same trim on device (%s) was "
7608                              "just done from node (%u), return.\n",
7609                              osb->dev_str, info.tf_nodenum);
7610                         range->len = info.tf_trimlen;
7611                         goto out_trimunlock;
7612                 }
7613         }
7614 
7615         info.tf_nodenum = osb->node_num;
7616         info.tf_start = start;
7617         info.tf_len = len;
7618         info.tf_minlen = minlen;
7619 
7620         /* Determine first and last group to examine based on start and len */
7621         first_group = ocfs2_which_cluster_group(main_bm_inode, start);
7622         if (first_group == osb->first_cluster_group_blkno)
7623                 first_bit = start;
7624         else
7625                 first_bit = start - ocfs2_blocks_to_clusters(sb, first_group);
7626         last_group = ocfs2_which_cluster_group(main_bm_inode, start + len - 1);
7627         last_bit = osb->bitmap_cpg;
7628 
7629         trimmed = 0;
7630         for (group = first_group; group <= last_group;) {
7631                 if (first_bit + len >= osb->bitmap_cpg)
7632                         last_bit = osb->bitmap_cpg;
7633                 else
7634                         last_bit = first_bit + len;
7635 
7636                 ret = ocfs2_read_group_descriptor(main_bm_inode,
7637                                                   main_bm, group,
7638                                                   &gd_bh);
7639                 if (ret < 0) {
7640                         mlog_errno(ret);
7641                         break;
7642                 }
7643 
7644                 gd = (struct ocfs2_group_desc *)gd_bh->b_data;
7645                 cnt = ocfs2_trim_group(sb, gd, group,
7646                                        first_bit, last_bit, minlen);
7647                 brelse(gd_bh);
7648                 gd_bh = NULL;
7649                 if (cnt < 0) {
7650                         ret = cnt;
7651                         mlog_errno(ret);
7652                         break;
7653                 }
7654 
7655                 trimmed += cnt;
7656                 len -= osb->bitmap_cpg - first_bit;
7657                 first_bit = 0;
7658                 if (group == osb->first_cluster_group_blkno)
7659                         group = ocfs2_clusters_to_blocks(sb, osb->bitmap_cpg);
7660                 else
7661                         group += ocfs2_clusters_to_blocks(sb, osb->bitmap_cpg);
7662         }
7663         range->len = trimmed * sb->s_blocksize;
7664 
7665         info.tf_trimlen = range->len;
7666         info.tf_success = (ret ? 0 : 1);
7667         pinfo = &info;
7668 out_trimunlock:
7669         ocfs2_trim_fs_unlock(osb, pinfo);
7670         ocfs2_trim_fs_lock_res_uninit(osb);
7671 out_unlock:
7672         ocfs2_inode_unlock(main_bm_inode, 0);
7673         brelse(main_bm_bh);
7674 out_mutex:
7675         inode_unlock(main_bm_inode);
7676         iput(main_bm_inode);
7677 out:
7678         return ret;
7679 }
7680 

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