~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/fs/btrfs/inode-map.c

Version: ~ [ linux-5.12-rc1 ] ~ [ linux-5.11.2 ] ~ [ linux-5.10.19 ] ~ [ linux-5.9.16 ] ~ [ linux-5.8.18 ] ~ [ linux-5.7.19 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.101 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.177 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.222 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.258 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.258 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.18.140 ] ~ [ linux-3.16.85 ] ~ [ linux-3.14.79 ] ~ [ linux-3.12.74 ] ~ [ linux-3.10.108 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  1 // SPDX-License-Identifier: GPL-2.0
  2 /*
  3  * Copyright (C) 2007 Oracle.  All rights reserved.
  4  */
  5 
  6 #include <linux/kthread.h>
  7 #include <linux/pagemap.h>
  8 
  9 #include "ctree.h"
 10 #include "disk-io.h"
 11 #include "free-space-cache.h"
 12 #include "inode-map.h"
 13 #include "transaction.h"
 14 
 15 static int caching_kthread(void *data)
 16 {
 17         struct btrfs_root *root = data;
 18         struct btrfs_fs_info *fs_info = root->fs_info;
 19         struct btrfs_free_space_ctl *ctl = root->free_ino_ctl;
 20         struct btrfs_key key;
 21         struct btrfs_path *path;
 22         struct extent_buffer *leaf;
 23         u64 last = (u64)-1;
 24         int slot;
 25         int ret;
 26 
 27         if (!btrfs_test_opt(fs_info, INODE_MAP_CACHE))
 28                 return 0;
 29 
 30         path = btrfs_alloc_path();
 31         if (!path)
 32                 return -ENOMEM;
 33 
 34         /* Since the commit root is read-only, we can safely skip locking. */
 35         path->skip_locking = 1;
 36         path->search_commit_root = 1;
 37         path->reada = READA_FORWARD;
 38 
 39         key.objectid = BTRFS_FIRST_FREE_OBJECTID;
 40         key.offset = 0;
 41         key.type = BTRFS_INODE_ITEM_KEY;
 42 again:
 43         /* need to make sure the commit_root doesn't disappear */
 44         down_read(&fs_info->commit_root_sem);
 45 
 46         ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
 47         if (ret < 0)
 48                 goto out;
 49 
 50         while (1) {
 51                 if (btrfs_fs_closing(fs_info))
 52                         goto out;
 53 
 54                 leaf = path->nodes[0];
 55                 slot = path->slots[0];
 56                 if (slot >= btrfs_header_nritems(leaf)) {
 57                         ret = btrfs_next_leaf(root, path);
 58                         if (ret < 0)
 59                                 goto out;
 60                         else if (ret > 0)
 61                                 break;
 62 
 63                         if (need_resched() ||
 64                             btrfs_transaction_in_commit(fs_info)) {
 65                                 leaf = path->nodes[0];
 66 
 67                                 if (WARN_ON(btrfs_header_nritems(leaf) == 0))
 68                                         break;
 69 
 70                                 /*
 71                                  * Save the key so we can advances forward
 72                                  * in the next search.
 73                                  */
 74                                 btrfs_item_key_to_cpu(leaf, &key, 0);
 75                                 btrfs_release_path(path);
 76                                 root->ino_cache_progress = last;
 77                                 up_read(&fs_info->commit_root_sem);
 78                                 schedule_timeout(1);
 79                                 goto again;
 80                         } else
 81                                 continue;
 82                 }
 83 
 84                 btrfs_item_key_to_cpu(leaf, &key, slot);
 85 
 86                 if (key.type != BTRFS_INODE_ITEM_KEY)
 87                         goto next;
 88 
 89                 if (key.objectid >= root->highest_objectid)
 90                         break;
 91 
 92                 if (last != (u64)-1 && last + 1 != key.objectid) {
 93                         __btrfs_add_free_space(fs_info, ctl, last + 1,
 94                                                key.objectid - last - 1);
 95                         wake_up(&root->ino_cache_wait);
 96                 }
 97 
 98                 last = key.objectid;
 99 next:
100                 path->slots[0]++;
101         }
102 
103         if (last < root->highest_objectid - 1) {
104                 __btrfs_add_free_space(fs_info, ctl, last + 1,
105                                        root->highest_objectid - last - 1);
106         }
107 
108         spin_lock(&root->ino_cache_lock);
109         root->ino_cache_state = BTRFS_CACHE_FINISHED;
110         spin_unlock(&root->ino_cache_lock);
111 
112         root->ino_cache_progress = (u64)-1;
113         btrfs_unpin_free_ino(root);
114 out:
115         wake_up(&root->ino_cache_wait);
116         up_read(&fs_info->commit_root_sem);
117 
118         btrfs_free_path(path);
119 
120         return ret;
121 }
122 
123 static void start_caching(struct btrfs_root *root)
124 {
125         struct btrfs_fs_info *fs_info = root->fs_info;
126         struct btrfs_free_space_ctl *ctl = root->free_ino_ctl;
127         struct task_struct *tsk;
128         int ret;
129         u64 objectid;
130 
131         if (!btrfs_test_opt(fs_info, INODE_MAP_CACHE))
132                 return;
133 
134         spin_lock(&root->ino_cache_lock);
135         if (root->ino_cache_state != BTRFS_CACHE_NO) {
136                 spin_unlock(&root->ino_cache_lock);
137                 return;
138         }
139 
140         root->ino_cache_state = BTRFS_CACHE_STARTED;
141         spin_unlock(&root->ino_cache_lock);
142 
143         ret = load_free_ino_cache(fs_info, root);
144         if (ret == 1) {
145                 spin_lock(&root->ino_cache_lock);
146                 root->ino_cache_state = BTRFS_CACHE_FINISHED;
147                 spin_unlock(&root->ino_cache_lock);
148                 return;
149         }
150 
151         /*
152          * It can be quite time-consuming to fill the cache by searching
153          * through the extent tree, and this can keep ino allocation path
154          * waiting. Therefore at start we quickly find out the highest
155          * inode number and we know we can use inode numbers which fall in
156          * [highest_ino + 1, BTRFS_LAST_FREE_OBJECTID].
157          */
158         ret = btrfs_find_free_objectid(root, &objectid);
159         if (!ret && objectid <= BTRFS_LAST_FREE_OBJECTID) {
160                 __btrfs_add_free_space(fs_info, ctl, objectid,
161                                        BTRFS_LAST_FREE_OBJECTID - objectid + 1);
162         }
163 
164         tsk = kthread_run(caching_kthread, root, "btrfs-ino-cache-%llu",
165                           root->root_key.objectid);
166         if (IS_ERR(tsk)) {
167                 btrfs_warn(fs_info, "failed to start inode caching task");
168                 btrfs_clear_pending_and_info(fs_info, INODE_MAP_CACHE,
169                                              "disabling inode map caching");
170         }
171 }
172 
173 int btrfs_find_free_ino(struct btrfs_root *root, u64 *objectid)
174 {
175         if (!btrfs_test_opt(root->fs_info, INODE_MAP_CACHE))
176                 return btrfs_find_free_objectid(root, objectid);
177 
178 again:
179         *objectid = btrfs_find_ino_for_alloc(root);
180 
181         if (*objectid != 0)
182                 return 0;
183 
184         start_caching(root);
185 
186         wait_event(root->ino_cache_wait,
187                    root->ino_cache_state == BTRFS_CACHE_FINISHED ||
188                    root->free_ino_ctl->free_space > 0);
189 
190         if (root->ino_cache_state == BTRFS_CACHE_FINISHED &&
191             root->free_ino_ctl->free_space == 0)
192                 return -ENOSPC;
193         else
194                 goto again;
195 }
196 
197 void btrfs_return_ino(struct btrfs_root *root, u64 objectid)
198 {
199         struct btrfs_fs_info *fs_info = root->fs_info;
200         struct btrfs_free_space_ctl *pinned = root->free_ino_pinned;
201 
202         if (!btrfs_test_opt(fs_info, INODE_MAP_CACHE))
203                 return;
204 again:
205         if (root->ino_cache_state == BTRFS_CACHE_FINISHED) {
206                 __btrfs_add_free_space(fs_info, pinned, objectid, 1);
207         } else {
208                 down_write(&fs_info->commit_root_sem);
209                 spin_lock(&root->ino_cache_lock);
210                 if (root->ino_cache_state == BTRFS_CACHE_FINISHED) {
211                         spin_unlock(&root->ino_cache_lock);
212                         up_write(&fs_info->commit_root_sem);
213                         goto again;
214                 }
215                 spin_unlock(&root->ino_cache_lock);
216 
217                 start_caching(root);
218 
219                 __btrfs_add_free_space(fs_info, pinned, objectid, 1);
220 
221                 up_write(&fs_info->commit_root_sem);
222         }
223 }
224 
225 /*
226  * When a transaction is committed, we'll move those inode numbers which are
227  * smaller than root->ino_cache_progress from pinned tree to free_ino tree, and
228  * others will just be dropped, because the commit root we were searching has
229  * changed.
230  *
231  * Must be called with root->fs_info->commit_root_sem held
232  */
233 void btrfs_unpin_free_ino(struct btrfs_root *root)
234 {
235         struct btrfs_free_space_ctl *ctl = root->free_ino_ctl;
236         struct rb_root *rbroot = &root->free_ino_pinned->free_space_offset;
237         spinlock_t *rbroot_lock = &root->free_ino_pinned->tree_lock;
238         struct btrfs_free_space *info;
239         struct rb_node *n;
240         u64 count;
241 
242         if (!btrfs_test_opt(root->fs_info, INODE_MAP_CACHE))
243                 return;
244 
245         while (1) {
246                 spin_lock(rbroot_lock);
247                 n = rb_first(rbroot);
248                 if (!n) {
249                         spin_unlock(rbroot_lock);
250                         break;
251                 }
252 
253                 info = rb_entry(n, struct btrfs_free_space, offset_index);
254                 BUG_ON(info->bitmap); /* Logic error */
255 
256                 if (info->offset > root->ino_cache_progress)
257                         count = 0;
258                 else
259                         count = min(root->ino_cache_progress - info->offset + 1,
260                                     info->bytes);
261 
262                 rb_erase(&info->offset_index, rbroot);
263                 spin_unlock(rbroot_lock);
264                 if (count)
265                         __btrfs_add_free_space(root->fs_info, ctl,
266                                                info->offset, count);
267                 kmem_cache_free(btrfs_free_space_cachep, info);
268         }
269 }
270 
271 #define INIT_THRESHOLD  ((SZ_32K / 2) / sizeof(struct btrfs_free_space))
272 #define INODES_PER_BITMAP (PAGE_SIZE * 8)
273 
274 /*
275  * The goal is to keep the memory used by the free_ino tree won't
276  * exceed the memory if we use bitmaps only.
277  */
278 static void recalculate_thresholds(struct btrfs_free_space_ctl *ctl)
279 {
280         struct btrfs_free_space *info;
281         struct rb_node *n;
282         int max_ino;
283         int max_bitmaps;
284 
285         n = rb_last(&ctl->free_space_offset);
286         if (!n) {
287                 ctl->extents_thresh = INIT_THRESHOLD;
288                 return;
289         }
290         info = rb_entry(n, struct btrfs_free_space, offset_index);
291 
292         /*
293          * Find the maximum inode number in the filesystem. Note we
294          * ignore the fact that this can be a bitmap, because we are
295          * not doing precise calculation.
296          */
297         max_ino = info->bytes - 1;
298 
299         max_bitmaps = ALIGN(max_ino, INODES_PER_BITMAP) / INODES_PER_BITMAP;
300         if (max_bitmaps <= ctl->total_bitmaps) {
301                 ctl->extents_thresh = 0;
302                 return;
303         }
304 
305         ctl->extents_thresh = (max_bitmaps - ctl->total_bitmaps) *
306                                 PAGE_SIZE / sizeof(*info);
307 }
308 
309 /*
310  * We don't fall back to bitmap, if we are below the extents threshold
311  * or this chunk of inode numbers is a big one.
312  */
313 static bool use_bitmap(struct btrfs_free_space_ctl *ctl,
314                        struct btrfs_free_space *info)
315 {
316         if (ctl->free_extents < ctl->extents_thresh ||
317             info->bytes > INODES_PER_BITMAP / 10)
318                 return false;
319 
320         return true;
321 }
322 
323 static const struct btrfs_free_space_op free_ino_op = {
324         .recalc_thresholds      = recalculate_thresholds,
325         .use_bitmap             = use_bitmap,
326 };
327 
328 static void pinned_recalc_thresholds(struct btrfs_free_space_ctl *ctl)
329 {
330 }
331 
332 static bool pinned_use_bitmap(struct btrfs_free_space_ctl *ctl,
333                               struct btrfs_free_space *info)
334 {
335         /*
336          * We always use extents for two reasons:
337          *
338          * - The pinned tree is only used during the process of caching
339          *   work.
340          * - Make code simpler. See btrfs_unpin_free_ino().
341          */
342         return false;
343 }
344 
345 static const struct btrfs_free_space_op pinned_free_ino_op = {
346         .recalc_thresholds      = pinned_recalc_thresholds,
347         .use_bitmap             = pinned_use_bitmap,
348 };
349 
350 void btrfs_init_free_ino_ctl(struct btrfs_root *root)
351 {
352         struct btrfs_free_space_ctl *ctl = root->free_ino_ctl;
353         struct btrfs_free_space_ctl *pinned = root->free_ino_pinned;
354 
355         spin_lock_init(&ctl->tree_lock);
356         ctl->unit = 1;
357         ctl->start = 0;
358         ctl->private = NULL;
359         ctl->op = &free_ino_op;
360         INIT_LIST_HEAD(&ctl->trimming_ranges);
361         mutex_init(&ctl->cache_writeout_mutex);
362 
363         /*
364          * Initially we allow to use 16K of ram to cache chunks of
365          * inode numbers before we resort to bitmaps. This is somewhat
366          * arbitrary, but it will be adjusted in runtime.
367          */
368         ctl->extents_thresh = INIT_THRESHOLD;
369 
370         spin_lock_init(&pinned->tree_lock);
371         pinned->unit = 1;
372         pinned->start = 0;
373         pinned->private = NULL;
374         pinned->extents_thresh = 0;
375         pinned->op = &pinned_free_ino_op;
376 }
377 
378 int btrfs_save_ino_cache(struct btrfs_root *root,
379                          struct btrfs_trans_handle *trans)
380 {
381         struct btrfs_fs_info *fs_info = root->fs_info;
382         struct btrfs_free_space_ctl *ctl = root->free_ino_ctl;
383         struct btrfs_path *path;
384         struct inode *inode;
385         struct btrfs_block_rsv *rsv;
386         struct extent_changeset *data_reserved = NULL;
387         u64 num_bytes;
388         u64 alloc_hint = 0;
389         int ret;
390         int prealloc;
391         bool retry = false;
392 
393         /* only fs tree and subvol/snap needs ino cache */
394         if (root->root_key.objectid != BTRFS_FS_TREE_OBJECTID &&
395             (root->root_key.objectid < BTRFS_FIRST_FREE_OBJECTID ||
396              root->root_key.objectid > BTRFS_LAST_FREE_OBJECTID))
397                 return 0;
398 
399         /* Don't save inode cache if we are deleting this root */
400         if (btrfs_root_refs(&root->root_item) == 0)
401                 return 0;
402 
403         if (!btrfs_test_opt(fs_info, INODE_MAP_CACHE))
404                 return 0;
405 
406         path = btrfs_alloc_path();
407         if (!path)
408                 return -ENOMEM;
409 
410         rsv = trans->block_rsv;
411         trans->block_rsv = &fs_info->trans_block_rsv;
412 
413         num_bytes = trans->bytes_reserved;
414         /*
415          * 1 item for inode item insertion if need
416          * 4 items for inode item update (in the worst case)
417          * 1 items for slack space if we need do truncation
418          * 1 item for free space object
419          * 3 items for pre-allocation
420          */
421         trans->bytes_reserved = btrfs_calc_trans_metadata_size(fs_info, 10);
422         ret = btrfs_block_rsv_add(root, trans->block_rsv,
423                                   trans->bytes_reserved,
424                                   BTRFS_RESERVE_NO_FLUSH);
425         if (ret)
426                 goto out;
427         trace_btrfs_space_reservation(fs_info, "ino_cache", trans->transid,
428                                       trans->bytes_reserved, 1);
429 again:
430         inode = lookup_free_ino_inode(root, path);
431         if (IS_ERR(inode) && (PTR_ERR(inode) != -ENOENT || retry)) {
432                 ret = PTR_ERR(inode);
433                 goto out_release;
434         }
435 
436         if (IS_ERR(inode)) {
437                 BUG_ON(retry); /* Logic error */
438                 retry = true;
439 
440                 ret = create_free_ino_inode(root, trans, path);
441                 if (ret)
442                         goto out_release;
443                 goto again;
444         }
445 
446         BTRFS_I(inode)->generation = 0;
447         ret = btrfs_update_inode(trans, root, inode);
448         if (ret) {
449                 btrfs_abort_transaction(trans, ret);
450                 goto out_put;
451         }
452 
453         if (i_size_read(inode) > 0) {
454                 ret = btrfs_truncate_free_space_cache(trans, NULL, inode);
455                 if (ret) {
456                         if (ret != -ENOSPC)
457                                 btrfs_abort_transaction(trans, ret);
458                         goto out_put;
459                 }
460         }
461 
462         spin_lock(&root->ino_cache_lock);
463         if (root->ino_cache_state != BTRFS_CACHE_FINISHED) {
464                 ret = -1;
465                 spin_unlock(&root->ino_cache_lock);
466                 goto out_put;
467         }
468         spin_unlock(&root->ino_cache_lock);
469 
470         spin_lock(&ctl->tree_lock);
471         prealloc = sizeof(struct btrfs_free_space) * ctl->free_extents;
472         prealloc = ALIGN(prealloc, PAGE_SIZE);
473         prealloc += ctl->total_bitmaps * PAGE_SIZE;
474         spin_unlock(&ctl->tree_lock);
475 
476         /* Just to make sure we have enough space */
477         prealloc += 8 * PAGE_SIZE;
478 
479         ret = btrfs_delalloc_reserve_space(inode, &data_reserved, 0, prealloc);
480         if (ret)
481                 goto out_put;
482 
483         ret = btrfs_prealloc_file_range_trans(inode, trans, 0, 0, prealloc,
484                                               prealloc, prealloc, &alloc_hint);
485         if (ret) {
486                 btrfs_delalloc_release_extents(BTRFS_I(inode), prealloc, true);
487                 goto out_put;
488         }
489 
490         ret = btrfs_write_out_ino_cache(root, trans, path, inode);
491         btrfs_delalloc_release_extents(BTRFS_I(inode), prealloc, false);
492 out_put:
493         iput(inode);
494 out_release:
495         trace_btrfs_space_reservation(fs_info, "ino_cache", trans->transid,
496                                       trans->bytes_reserved, 0);
497         btrfs_block_rsv_release(fs_info, trans->block_rsv,
498                                 trans->bytes_reserved);
499 out:
500         trans->block_rsv = rsv;
501         trans->bytes_reserved = num_bytes;
502 
503         btrfs_free_path(path);
504         extent_changeset_free(data_reserved);
505         return ret;
506 }
507 
508 int btrfs_find_highest_objectid(struct btrfs_root *root, u64 *objectid)
509 {
510         struct btrfs_path *path;
511         int ret;
512         struct extent_buffer *l;
513         struct btrfs_key search_key;
514         struct btrfs_key found_key;
515         int slot;
516 
517         path = btrfs_alloc_path();
518         if (!path)
519                 return -ENOMEM;
520 
521         search_key.objectid = BTRFS_LAST_FREE_OBJECTID;
522         search_key.type = -1;
523         search_key.offset = (u64)-1;
524         ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0);
525         if (ret < 0)
526                 goto error;
527         BUG_ON(ret == 0); /* Corruption */
528         if (path->slots[0] > 0) {
529                 slot = path->slots[0] - 1;
530                 l = path->nodes[0];
531                 btrfs_item_key_to_cpu(l, &found_key, slot);
532                 *objectid = max_t(u64, found_key.objectid,
533                                   BTRFS_FIRST_FREE_OBJECTID - 1);
534         } else {
535                 *objectid = BTRFS_FIRST_FREE_OBJECTID - 1;
536         }
537         ret = 0;
538 error:
539         btrfs_free_path(path);
540         return ret;
541 }
542 
543 int btrfs_find_free_objectid(struct btrfs_root *root, u64 *objectid)
544 {
545         int ret;
546         mutex_lock(&root->objectid_mutex);
547 
548         if (unlikely(root->highest_objectid >= BTRFS_LAST_FREE_OBJECTID)) {
549                 btrfs_warn(root->fs_info,
550                            "the objectid of root %llu reaches its highest value",
551                            root->root_key.objectid);
552                 ret = -ENOSPC;
553                 goto out;
554         }
555 
556         *objectid = ++root->highest_objectid;
557         ret = 0;
558 out:
559         mutex_unlock(&root->objectid_mutex);
560         return ret;
561 }
562 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp