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

TOMOYO Linux Cross Reference
Linux/fs/btrfs/disk-io.c

Version: ~ [ linux-5.15-rc1 ] ~ [ linux-5.14.5 ] ~ [ linux-5.13.18 ] ~ [ linux-5.12.19 ] ~ [ linux-5.11.22 ] ~ [ linux-5.10.66 ] ~ [ linux-5.9.16 ] ~ [ linux-5.8.18 ] ~ [ linux-5.7.19 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.147 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.206 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.246 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.282 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.283 ] ~ [ 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 /*
  2  * Copyright (C) 2007 Oracle.  All rights reserved.
  3  *
  4  * This program is free software; you can redistribute it and/or
  5  * modify it under the terms of the GNU General Public
  6  * License v2 as published by the Free Software Foundation.
  7  *
  8  * This program is distributed in the hope that it will be useful,
  9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
 10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 11  * General Public License for more details.
 12  *
 13  * You should have received a copy of the GNU General Public
 14  * License along with this program; if not, write to the
 15  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 16  * Boston, MA 021110-1307, USA.
 17  */
 18 
 19 #include <linux/fs.h>
 20 #include <linux/blkdev.h>
 21 #include <linux/scatterlist.h>
 22 #include <linux/swap.h>
 23 #include <linux/radix-tree.h>
 24 #include <linux/writeback.h>
 25 #include <linux/buffer_head.h>
 26 #include <linux/workqueue.h>
 27 #include <linux/kthread.h>
 28 #include <linux/freezer.h>
 29 #include <linux/slab.h>
 30 #include <linux/migrate.h>
 31 #include <linux/ratelimit.h>
 32 #include <linux/uuid.h>
 33 #include <linux/semaphore.h>
 34 #include <asm/unaligned.h>
 35 #include "ctree.h"
 36 #include "disk-io.h"
 37 #include "hash.h"
 38 #include "transaction.h"
 39 #include "btrfs_inode.h"
 40 #include "volumes.h"
 41 #include "print-tree.h"
 42 #include "locking.h"
 43 #include "tree-log.h"
 44 #include "free-space-cache.h"
 45 #include "inode-map.h"
 46 #include "check-integrity.h"
 47 #include "rcu-string.h"
 48 #include "dev-replace.h"
 49 #include "raid56.h"
 50 #include "sysfs.h"
 51 #include "qgroup.h"
 52 
 53 #ifdef CONFIG_X86
 54 #include <asm/cpufeature.h>
 55 #endif
 56 
 57 static struct extent_io_ops btree_extent_io_ops;
 58 static void end_workqueue_fn(struct btrfs_work *work);
 59 static void free_fs_root(struct btrfs_root *root);
 60 static int btrfs_check_super_valid(struct btrfs_fs_info *fs_info,
 61                                     int read_only);
 62 static void btrfs_destroy_ordered_extents(struct btrfs_root *root);
 63 static int btrfs_destroy_delayed_refs(struct btrfs_transaction *trans,
 64                                       struct btrfs_root *root);
 65 static void btrfs_destroy_delalloc_inodes(struct btrfs_root *root);
 66 static int btrfs_destroy_marked_extents(struct btrfs_root *root,
 67                                         struct extent_io_tree *dirty_pages,
 68                                         int mark);
 69 static int btrfs_destroy_pinned_extent(struct btrfs_root *root,
 70                                        struct extent_io_tree *pinned_extents);
 71 static int btrfs_cleanup_transaction(struct btrfs_root *root);
 72 static void btrfs_error_commit_super(struct btrfs_root *root);
 73 
 74 /*
 75  * btrfs_end_io_wq structs are used to do processing in task context when an IO
 76  * is complete.  This is used during reads to verify checksums, and it is used
 77  * by writes to insert metadata for new file extents after IO is complete.
 78  */
 79 struct btrfs_end_io_wq {
 80         struct bio *bio;
 81         bio_end_io_t *end_io;
 82         void *private;
 83         struct btrfs_fs_info *info;
 84         int error;
 85         enum btrfs_wq_endio_type metadata;
 86         struct list_head list;
 87         struct btrfs_work work;
 88 };
 89 
 90 static struct kmem_cache *btrfs_end_io_wq_cache;
 91 
 92 int __init btrfs_end_io_wq_init(void)
 93 {
 94         btrfs_end_io_wq_cache = kmem_cache_create("btrfs_end_io_wq",
 95                                         sizeof(struct btrfs_end_io_wq),
 96                                         0,
 97                                         SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD,
 98                                         NULL);
 99         if (!btrfs_end_io_wq_cache)
100                 return -ENOMEM;
101         return 0;
102 }
103 
104 void btrfs_end_io_wq_exit(void)
105 {
106         if (btrfs_end_io_wq_cache)
107                 kmem_cache_destroy(btrfs_end_io_wq_cache);
108 }
109 
110 /*
111  * async submit bios are used to offload expensive checksumming
112  * onto the worker threads.  They checksum file and metadata bios
113  * just before they are sent down the IO stack.
114  */
115 struct async_submit_bio {
116         struct inode *inode;
117         struct bio *bio;
118         struct list_head list;
119         extent_submit_bio_hook_t *submit_bio_start;
120         extent_submit_bio_hook_t *submit_bio_done;
121         int rw;
122         int mirror_num;
123         unsigned long bio_flags;
124         /*
125          * bio_offset is optional, can be used if the pages in the bio
126          * can't tell us where in the file the bio should go
127          */
128         u64 bio_offset;
129         struct btrfs_work work;
130         int error;
131 };
132 
133 /*
134  * Lockdep class keys for extent_buffer->lock's in this root.  For a given
135  * eb, the lockdep key is determined by the btrfs_root it belongs to and
136  * the level the eb occupies in the tree.
137  *
138  * Different roots are used for different purposes and may nest inside each
139  * other and they require separate keysets.  As lockdep keys should be
140  * static, assign keysets according to the purpose of the root as indicated
141  * by btrfs_root->objectid.  This ensures that all special purpose roots
142  * have separate keysets.
143  *
144  * Lock-nesting across peer nodes is always done with the immediate parent
145  * node locked thus preventing deadlock.  As lockdep doesn't know this, use
146  * subclass to avoid triggering lockdep warning in such cases.
147  *
148  * The key is set by the readpage_end_io_hook after the buffer has passed
149  * csum validation but before the pages are unlocked.  It is also set by
150  * btrfs_init_new_buffer on freshly allocated blocks.
151  *
152  * We also add a check to make sure the highest level of the tree is the
153  * same as our lockdep setup here.  If BTRFS_MAX_LEVEL changes, this code
154  * needs update as well.
155  */
156 #ifdef CONFIG_DEBUG_LOCK_ALLOC
157 # if BTRFS_MAX_LEVEL != 8
158 #  error
159 # endif
160 
161 static struct btrfs_lockdep_keyset {
162         u64                     id;             /* root objectid */
163         const char              *name_stem;     /* lock name stem */
164         char                    names[BTRFS_MAX_LEVEL + 1][20];
165         struct lock_class_key   keys[BTRFS_MAX_LEVEL + 1];
166 } btrfs_lockdep_keysets[] = {
167         { .id = BTRFS_ROOT_TREE_OBJECTID,       .name_stem = "root"     },
168         { .id = BTRFS_EXTENT_TREE_OBJECTID,     .name_stem = "extent"   },
169         { .id = BTRFS_CHUNK_TREE_OBJECTID,      .name_stem = "chunk"    },
170         { .id = BTRFS_DEV_TREE_OBJECTID,        .name_stem = "dev"      },
171         { .id = BTRFS_FS_TREE_OBJECTID,         .name_stem = "fs"       },
172         { .id = BTRFS_CSUM_TREE_OBJECTID,       .name_stem = "csum"     },
173         { .id = BTRFS_QUOTA_TREE_OBJECTID,      .name_stem = "quota"    },
174         { .id = BTRFS_TREE_LOG_OBJECTID,        .name_stem = "log"      },
175         { .id = BTRFS_TREE_RELOC_OBJECTID,      .name_stem = "treloc"   },
176         { .id = BTRFS_DATA_RELOC_TREE_OBJECTID, .name_stem = "dreloc"   },
177         { .id = BTRFS_UUID_TREE_OBJECTID,       .name_stem = "uuid"     },
178         { .id = 0,                              .name_stem = "tree"     },
179 };
180 
181 void __init btrfs_init_lockdep(void)
182 {
183         int i, j;
184 
185         /* initialize lockdep class names */
186         for (i = 0; i < ARRAY_SIZE(btrfs_lockdep_keysets); i++) {
187                 struct btrfs_lockdep_keyset *ks = &btrfs_lockdep_keysets[i];
188 
189                 for (j = 0; j < ARRAY_SIZE(ks->names); j++)
190                         snprintf(ks->names[j], sizeof(ks->names[j]),
191                                  "btrfs-%s-%02d", ks->name_stem, j);
192         }
193 }
194 
195 void btrfs_set_buffer_lockdep_class(u64 objectid, struct extent_buffer *eb,
196                                     int level)
197 {
198         struct btrfs_lockdep_keyset *ks;
199 
200         BUG_ON(level >= ARRAY_SIZE(ks->keys));
201 
202         /* find the matching keyset, id 0 is the default entry */
203         for (ks = btrfs_lockdep_keysets; ks->id; ks++)
204                 if (ks->id == objectid)
205                         break;
206 
207         lockdep_set_class_and_name(&eb->lock,
208                                    &ks->keys[level], ks->names[level]);
209 }
210 
211 #endif
212 
213 /*
214  * extents on the btree inode are pretty simple, there's one extent
215  * that covers the entire device
216  */
217 static struct extent_map *btree_get_extent(struct inode *inode,
218                 struct page *page, size_t pg_offset, u64 start, u64 len,
219                 int create)
220 {
221         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
222         struct extent_map *em;
223         int ret;
224 
225         read_lock(&em_tree->lock);
226         em = lookup_extent_mapping(em_tree, start, len);
227         if (em) {
228                 em->bdev =
229                         BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
230                 read_unlock(&em_tree->lock);
231                 goto out;
232         }
233         read_unlock(&em_tree->lock);
234 
235         em = alloc_extent_map();
236         if (!em) {
237                 em = ERR_PTR(-ENOMEM);
238                 goto out;
239         }
240         em->start = 0;
241         em->len = (u64)-1;
242         em->block_len = (u64)-1;
243         em->block_start = 0;
244         em->bdev = BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
245 
246         write_lock(&em_tree->lock);
247         ret = add_extent_mapping(em_tree, em, 0);
248         if (ret == -EEXIST) {
249                 free_extent_map(em);
250                 em = lookup_extent_mapping(em_tree, start, len);
251                 if (!em)
252                         em = ERR_PTR(-EIO);
253         } else if (ret) {
254                 free_extent_map(em);
255                 em = ERR_PTR(ret);
256         }
257         write_unlock(&em_tree->lock);
258 
259 out:
260         return em;
261 }
262 
263 u32 btrfs_csum_data(char *data, u32 seed, size_t len)
264 {
265         return btrfs_crc32c(seed, data, len);
266 }
267 
268 void btrfs_csum_final(u32 crc, char *result)
269 {
270         put_unaligned_le32(~crc, result);
271 }
272 
273 /*
274  * compute the csum for a btree block, and either verify it or write it
275  * into the csum field of the block.
276  */
277 static int csum_tree_block(struct btrfs_root *root, struct extent_buffer *buf,
278                            int verify)
279 {
280         u16 csum_size = btrfs_super_csum_size(root->fs_info->super_copy);
281         char *result = NULL;
282         unsigned long len;
283         unsigned long cur_len;
284         unsigned long offset = BTRFS_CSUM_SIZE;
285         char *kaddr;
286         unsigned long map_start;
287         unsigned long map_len;
288         int err;
289         u32 crc = ~(u32)0;
290         unsigned long inline_result;
291 
292         len = buf->len - offset;
293         while (len > 0) {
294                 err = map_private_extent_buffer(buf, offset, 32,
295                                         &kaddr, &map_start, &map_len);
296                 if (err)
297                         return 1;
298                 cur_len = min(len, map_len - (offset - map_start));
299                 crc = btrfs_csum_data(kaddr + offset - map_start,
300                                       crc, cur_len);
301                 len -= cur_len;
302                 offset += cur_len;
303         }
304         if (csum_size > sizeof(inline_result)) {
305                 result = kzalloc(csum_size * sizeof(char), GFP_NOFS);
306                 if (!result)
307                         return 1;
308         } else {
309                 result = (char *)&inline_result;
310         }
311 
312         btrfs_csum_final(crc, result);
313 
314         if (verify) {
315                 if (memcmp_extent_buffer(buf, result, 0, csum_size)) {
316                         u32 val;
317                         u32 found = 0;
318                         memcpy(&found, result, csum_size);
319 
320                         read_extent_buffer(buf, &val, 0, csum_size);
321                         printk_ratelimited(KERN_INFO
322                                 "BTRFS: %s checksum verify failed on %llu wanted %X found %X "
323                                 "level %d\n",
324                                 root->fs_info->sb->s_id, buf->start,
325                                 val, found, btrfs_header_level(buf));
326                         if (result != (char *)&inline_result)
327                                 kfree(result);
328                         return 1;
329                 }
330         } else {
331                 write_extent_buffer(buf, result, 0, csum_size);
332         }
333         if (result != (char *)&inline_result)
334                 kfree(result);
335         return 0;
336 }
337 
338 /*
339  * we can't consider a given block up to date unless the transid of the
340  * block matches the transid in the parent node's pointer.  This is how we
341  * detect blocks that either didn't get written at all or got written
342  * in the wrong place.
343  */
344 static int verify_parent_transid(struct extent_io_tree *io_tree,
345                                  struct extent_buffer *eb, u64 parent_transid,
346                                  int atomic)
347 {
348         struct extent_state *cached_state = NULL;
349         int ret;
350         bool need_lock = (current->journal_info == BTRFS_SEND_TRANS_STUB);
351 
352         if (!parent_transid || btrfs_header_generation(eb) == parent_transid)
353                 return 0;
354 
355         if (atomic)
356                 return -EAGAIN;
357 
358         if (need_lock) {
359                 btrfs_tree_read_lock(eb);
360                 btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK);
361         }
362 
363         lock_extent_bits(io_tree, eb->start, eb->start + eb->len - 1,
364                          0, &cached_state);
365         if (extent_buffer_uptodate(eb) &&
366             btrfs_header_generation(eb) == parent_transid) {
367                 ret = 0;
368                 goto out;
369         }
370         printk_ratelimited(KERN_INFO "BTRFS (device %s): parent transid verify failed on %llu wanted %llu found %llu\n",
371                         eb->fs_info->sb->s_id, eb->start,
372                         parent_transid, btrfs_header_generation(eb));
373         ret = 1;
374 
375         /*
376          * Things reading via commit roots that don't have normal protection,
377          * like send, can have a really old block in cache that may point at a
378          * block that has been free'd and re-allocated.  So don't clear uptodate
379          * if we find an eb that is under IO (dirty/writeback) because we could
380          * end up reading in the stale data and then writing it back out and
381          * making everybody very sad.
382          */
383         if (!extent_buffer_under_io(eb))
384                 clear_extent_buffer_uptodate(eb);
385 out:
386         unlock_extent_cached(io_tree, eb->start, eb->start + eb->len - 1,
387                              &cached_state, GFP_NOFS);
388         if (need_lock)
389                 btrfs_tree_read_unlock_blocking(eb);
390         return ret;
391 }
392 
393 /*
394  * Return 0 if the superblock checksum type matches the checksum value of that
395  * algorithm. Pass the raw disk superblock data.
396  */
397 static int btrfs_check_super_csum(char *raw_disk_sb)
398 {
399         struct btrfs_super_block *disk_sb =
400                 (struct btrfs_super_block *)raw_disk_sb;
401         u16 csum_type = btrfs_super_csum_type(disk_sb);
402         int ret = 0;
403 
404         if (csum_type == BTRFS_CSUM_TYPE_CRC32) {
405                 u32 crc = ~(u32)0;
406                 const int csum_size = sizeof(crc);
407                 char result[csum_size];
408 
409                 /*
410                  * The super_block structure does not span the whole
411                  * BTRFS_SUPER_INFO_SIZE range, we expect that the unused space
412                  * is filled with zeros and is included in the checkum.
413                  */
414                 crc = btrfs_csum_data(raw_disk_sb + BTRFS_CSUM_SIZE,
415                                 crc, BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE);
416                 btrfs_csum_final(crc, result);
417 
418                 if (memcmp(raw_disk_sb, result, csum_size))
419                         ret = 1;
420 
421                 if (ret && btrfs_super_generation(disk_sb) < 10) {
422                         printk(KERN_WARNING
423                                 "BTRFS: super block crcs don't match, older mkfs detected\n");
424                         ret = 0;
425                 }
426         }
427 
428         if (csum_type >= ARRAY_SIZE(btrfs_csum_sizes)) {
429                 printk(KERN_ERR "BTRFS: unsupported checksum algorithm %u\n",
430                                 csum_type);
431                 ret = 1;
432         }
433 
434         return ret;
435 }
436 
437 /*
438  * helper to read a given tree block, doing retries as required when
439  * the checksums don't match and we have alternate mirrors to try.
440  */
441 static int btree_read_extent_buffer_pages(struct btrfs_root *root,
442                                           struct extent_buffer *eb,
443                                           u64 start, u64 parent_transid)
444 {
445         struct extent_io_tree *io_tree;
446         int failed = 0;
447         int ret;
448         int num_copies = 0;
449         int mirror_num = 0;
450         int failed_mirror = 0;
451 
452         clear_bit(EXTENT_BUFFER_CORRUPT, &eb->bflags);
453         io_tree = &BTRFS_I(root->fs_info->btree_inode)->io_tree;
454         while (1) {
455                 ret = read_extent_buffer_pages(io_tree, eb, start,
456                                                WAIT_COMPLETE,
457                                                btree_get_extent, mirror_num);
458                 if (!ret) {
459                         if (!verify_parent_transid(io_tree, eb,
460                                                    parent_transid, 0))
461                                 break;
462                         else
463                                 ret = -EIO;
464                 }
465 
466                 /*
467                  * This buffer's crc is fine, but its contents are corrupted, so
468                  * there is no reason to read the other copies, they won't be
469                  * any less wrong.
470                  */
471                 if (test_bit(EXTENT_BUFFER_CORRUPT, &eb->bflags))
472                         break;
473 
474                 num_copies = btrfs_num_copies(root->fs_info,
475                                               eb->start, eb->len);
476                 if (num_copies == 1)
477                         break;
478 
479                 if (!failed_mirror) {
480                         failed = 1;
481                         failed_mirror = eb->read_mirror;
482                 }
483 
484                 mirror_num++;
485                 if (mirror_num == failed_mirror)
486                         mirror_num++;
487 
488                 if (mirror_num > num_copies)
489                         break;
490         }
491 
492         if (failed && !ret && failed_mirror)
493                 repair_eb_io_failure(root, eb, failed_mirror);
494 
495         return ret;
496 }
497 
498 /*
499  * checksum a dirty tree block before IO.  This has extra checks to make sure
500  * we only fill in the checksum field in the first page of a multi-page block
501  */
502 
503 static int csum_dirty_buffer(struct btrfs_root *root, struct page *page)
504 {
505         u64 start = page_offset(page);
506         u64 found_start;
507         struct extent_buffer *eb;
508 
509         eb = (struct extent_buffer *)page->private;
510         if (page != eb->pages[0])
511                 return 0;
512         found_start = btrfs_header_bytenr(eb);
513         if (WARN_ON(found_start != start || !PageUptodate(page)))
514                 return 0;
515         csum_tree_block(root, eb, 0);
516         return 0;
517 }
518 
519 static int check_tree_block_fsid(struct btrfs_root *root,
520                                  struct extent_buffer *eb)
521 {
522         struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
523         u8 fsid[BTRFS_UUID_SIZE];
524         int ret = 1;
525 
526         read_extent_buffer(eb, fsid, btrfs_header_fsid(), BTRFS_FSID_SIZE);
527         while (fs_devices) {
528                 if (!memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE)) {
529                         ret = 0;
530                         break;
531                 }
532                 fs_devices = fs_devices->seed;
533         }
534         return ret;
535 }
536 
537 #define CORRUPT(reason, eb, root, slot)                         \
538         btrfs_crit(root->fs_info, "corrupt leaf, %s: block=%llu,"       \
539                    "root=%llu, slot=%d", reason,                        \
540                btrfs_header_bytenr(eb), root->objectid, slot)
541 
542 static noinline int check_leaf(struct btrfs_root *root,
543                                struct extent_buffer *leaf)
544 {
545         struct btrfs_key key;
546         struct btrfs_key leaf_key;
547         u32 nritems = btrfs_header_nritems(leaf);
548         int slot;
549 
550         if (nritems == 0)
551                 return 0;
552 
553         /* Check the 0 item */
554         if (btrfs_item_offset_nr(leaf, 0) + btrfs_item_size_nr(leaf, 0) !=
555             BTRFS_LEAF_DATA_SIZE(root)) {
556                 CORRUPT("invalid item offset size pair", leaf, root, 0);
557                 return -EIO;
558         }
559 
560         /*
561          * Check to make sure each items keys are in the correct order and their
562          * offsets make sense.  We only have to loop through nritems-1 because
563          * we check the current slot against the next slot, which verifies the
564          * next slot's offset+size makes sense and that the current's slot
565          * offset is correct.
566          */
567         for (slot = 0; slot < nritems - 1; slot++) {
568                 btrfs_item_key_to_cpu(leaf, &leaf_key, slot);
569                 btrfs_item_key_to_cpu(leaf, &key, slot + 1);
570 
571                 /* Make sure the keys are in the right order */
572                 if (btrfs_comp_cpu_keys(&leaf_key, &key) >= 0) {
573                         CORRUPT("bad key order", leaf, root, slot);
574                         return -EIO;
575                 }
576 
577                 /*
578                  * Make sure the offset and ends are right, remember that the
579                  * item data starts at the end of the leaf and grows towards the
580                  * front.
581                  */
582                 if (btrfs_item_offset_nr(leaf, slot) !=
583                         btrfs_item_end_nr(leaf, slot + 1)) {
584                         CORRUPT("slot offset bad", leaf, root, slot);
585                         return -EIO;
586                 }
587 
588                 /*
589                  * Check to make sure that we don't point outside of the leaf,
590                  * just incase all the items are consistent to eachother, but
591                  * all point outside of the leaf.
592                  */
593                 if (btrfs_item_end_nr(leaf, slot) >
594                     BTRFS_LEAF_DATA_SIZE(root)) {
595                         CORRUPT("slot end outside of leaf", leaf, root, slot);
596                         return -EIO;
597                 }
598         }
599 
600         return 0;
601 }
602 
603 static int btree_readpage_end_io_hook(struct btrfs_io_bio *io_bio,
604                                       u64 phy_offset, struct page *page,
605                                       u64 start, u64 end, int mirror)
606 {
607         u64 found_start;
608         int found_level;
609         struct extent_buffer *eb;
610         struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
611         int ret = 0;
612         int reads_done;
613 
614         if (!page->private)
615                 goto out;
616 
617         eb = (struct extent_buffer *)page->private;
618 
619         /* the pending IO might have been the only thing that kept this buffer
620          * in memory.  Make sure we have a ref for all this other checks
621          */
622         extent_buffer_get(eb);
623 
624         reads_done = atomic_dec_and_test(&eb->io_pages);
625         if (!reads_done)
626                 goto err;
627 
628         eb->read_mirror = mirror;
629         if (test_bit(EXTENT_BUFFER_READ_ERR, &eb->bflags)) {
630                 ret = -EIO;
631                 goto err;
632         }
633 
634         found_start = btrfs_header_bytenr(eb);
635         if (found_start != eb->start) {
636                 printk_ratelimited(KERN_INFO "BTRFS (device %s): bad tree block start "
637                                "%llu %llu\n",
638                                eb->fs_info->sb->s_id, found_start, eb->start);
639                 ret = -EIO;
640                 goto err;
641         }
642         if (check_tree_block_fsid(root, eb)) {
643                 printk_ratelimited(KERN_INFO "BTRFS (device %s): bad fsid on block %llu\n",
644                                eb->fs_info->sb->s_id, eb->start);
645                 ret = -EIO;
646                 goto err;
647         }
648         found_level = btrfs_header_level(eb);
649         if (found_level >= BTRFS_MAX_LEVEL) {
650                 btrfs_info(root->fs_info, "bad tree block level %d",
651                            (int)btrfs_header_level(eb));
652                 ret = -EIO;
653                 goto err;
654         }
655 
656         btrfs_set_buffer_lockdep_class(btrfs_header_owner(eb),
657                                        eb, found_level);
658 
659         ret = csum_tree_block(root, eb, 1);
660         if (ret) {
661                 ret = -EIO;
662                 goto err;
663         }
664 
665         /*
666          * If this is a leaf block and it is corrupt, set the corrupt bit so
667          * that we don't try and read the other copies of this block, just
668          * return -EIO.
669          */
670         if (found_level == 0 && check_leaf(root, eb)) {
671                 set_bit(EXTENT_BUFFER_CORRUPT, &eb->bflags);
672                 ret = -EIO;
673         }
674 
675         if (!ret)
676                 set_extent_buffer_uptodate(eb);
677 err:
678         if (reads_done &&
679             test_and_clear_bit(EXTENT_BUFFER_READAHEAD, &eb->bflags))
680                 btree_readahead_hook(root, eb, eb->start, ret);
681 
682         if (ret) {
683                 /*
684                  * our io error hook is going to dec the io pages
685                  * again, we have to make sure it has something
686                  * to decrement
687                  */
688                 atomic_inc(&eb->io_pages);
689                 clear_extent_buffer_uptodate(eb);
690         }
691         free_extent_buffer(eb);
692 out:
693         return ret;
694 }
695 
696 static int btree_io_failed_hook(struct page *page, int failed_mirror)
697 {
698         struct extent_buffer *eb;
699         struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
700 
701         eb = (struct extent_buffer *)page->private;
702         set_bit(EXTENT_BUFFER_READ_ERR, &eb->bflags);
703         eb->read_mirror = failed_mirror;
704         atomic_dec(&eb->io_pages);
705         if (test_and_clear_bit(EXTENT_BUFFER_READAHEAD, &eb->bflags))
706                 btree_readahead_hook(root, eb, eb->start, -EIO);
707         return -EIO;    /* we fixed nothing */
708 }
709 
710 static void end_workqueue_bio(struct bio *bio, int err)
711 {
712         struct btrfs_end_io_wq *end_io_wq = bio->bi_private;
713         struct btrfs_fs_info *fs_info;
714         struct btrfs_workqueue *wq;
715         btrfs_work_func_t func;
716 
717         fs_info = end_io_wq->info;
718         end_io_wq->error = err;
719 
720         if (bio->bi_rw & REQ_WRITE) {
721                 if (end_io_wq->metadata == BTRFS_WQ_ENDIO_METADATA) {
722                         wq = fs_info->endio_meta_write_workers;
723                         func = btrfs_endio_meta_write_helper;
724                 } else if (end_io_wq->metadata == BTRFS_WQ_ENDIO_FREE_SPACE) {
725                         wq = fs_info->endio_freespace_worker;
726                         func = btrfs_freespace_write_helper;
727                 } else if (end_io_wq->metadata == BTRFS_WQ_ENDIO_RAID56) {
728                         wq = fs_info->endio_raid56_workers;
729                         func = btrfs_endio_raid56_helper;
730                 } else {
731                         wq = fs_info->endio_write_workers;
732                         func = btrfs_endio_write_helper;
733                 }
734         } else {
735                 if (unlikely(end_io_wq->metadata ==
736                              BTRFS_WQ_ENDIO_DIO_REPAIR)) {
737                         wq = fs_info->endio_repair_workers;
738                         func = btrfs_endio_repair_helper;
739                 } else if (end_io_wq->metadata == BTRFS_WQ_ENDIO_RAID56) {
740                         wq = fs_info->endio_raid56_workers;
741                         func = btrfs_endio_raid56_helper;
742                 } else if (end_io_wq->metadata) {
743                         wq = fs_info->endio_meta_workers;
744                         func = btrfs_endio_meta_helper;
745                 } else {
746                         wq = fs_info->endio_workers;
747                         func = btrfs_endio_helper;
748                 }
749         }
750 
751         btrfs_init_work(&end_io_wq->work, func, end_workqueue_fn, NULL, NULL);
752         btrfs_queue_work(wq, &end_io_wq->work);
753 }
754 
755 int btrfs_bio_wq_end_io(struct btrfs_fs_info *info, struct bio *bio,
756                         enum btrfs_wq_endio_type metadata)
757 {
758         struct btrfs_end_io_wq *end_io_wq;
759 
760         end_io_wq = kmem_cache_alloc(btrfs_end_io_wq_cache, GFP_NOFS);
761         if (!end_io_wq)
762                 return -ENOMEM;
763 
764         end_io_wq->private = bio->bi_private;
765         end_io_wq->end_io = bio->bi_end_io;
766         end_io_wq->info = info;
767         end_io_wq->error = 0;
768         end_io_wq->bio = bio;
769         end_io_wq->metadata = metadata;
770 
771         bio->bi_private = end_io_wq;
772         bio->bi_end_io = end_workqueue_bio;
773         return 0;
774 }
775 
776 unsigned long btrfs_async_submit_limit(struct btrfs_fs_info *info)
777 {
778         unsigned long limit = min_t(unsigned long,
779                                     info->thread_pool_size,
780                                     info->fs_devices->open_devices);
781         return 256 * limit;
782 }
783 
784 static void run_one_async_start(struct btrfs_work *work)
785 {
786         struct async_submit_bio *async;
787         int ret;
788 
789         async = container_of(work, struct  async_submit_bio, work);
790         ret = async->submit_bio_start(async->inode, async->rw, async->bio,
791                                       async->mirror_num, async->bio_flags,
792                                       async->bio_offset);
793         if (ret)
794                 async->error = ret;
795 }
796 
797 static void run_one_async_done(struct btrfs_work *work)
798 {
799         struct btrfs_fs_info *fs_info;
800         struct async_submit_bio *async;
801         int limit;
802 
803         async = container_of(work, struct  async_submit_bio, work);
804         fs_info = BTRFS_I(async->inode)->root->fs_info;
805 
806         limit = btrfs_async_submit_limit(fs_info);
807         limit = limit * 2 / 3;
808 
809         if (atomic_dec_return(&fs_info->nr_async_submits) < limit &&
810             waitqueue_active(&fs_info->async_submit_wait))
811                 wake_up(&fs_info->async_submit_wait);
812 
813         /* If an error occured we just want to clean up the bio and move on */
814         if (async->error) {
815                 bio_endio(async->bio, async->error);
816                 return;
817         }
818 
819         async->submit_bio_done(async->inode, async->rw, async->bio,
820                                async->mirror_num, async->bio_flags,
821                                async->bio_offset);
822 }
823 
824 static void run_one_async_free(struct btrfs_work *work)
825 {
826         struct async_submit_bio *async;
827 
828         async = container_of(work, struct  async_submit_bio, work);
829         kfree(async);
830 }
831 
832 int btrfs_wq_submit_bio(struct btrfs_fs_info *fs_info, struct inode *inode,
833                         int rw, struct bio *bio, int mirror_num,
834                         unsigned long bio_flags,
835                         u64 bio_offset,
836                         extent_submit_bio_hook_t *submit_bio_start,
837                         extent_submit_bio_hook_t *submit_bio_done)
838 {
839         struct async_submit_bio *async;
840 
841         async = kmalloc(sizeof(*async), GFP_NOFS);
842         if (!async)
843                 return -ENOMEM;
844 
845         async->inode = inode;
846         async->rw = rw;
847         async->bio = bio;
848         async->mirror_num = mirror_num;
849         async->submit_bio_start = submit_bio_start;
850         async->submit_bio_done = submit_bio_done;
851 
852         btrfs_init_work(&async->work, btrfs_worker_helper, run_one_async_start,
853                         run_one_async_done, run_one_async_free);
854 
855         async->bio_flags = bio_flags;
856         async->bio_offset = bio_offset;
857 
858         async->error = 0;
859 
860         atomic_inc(&fs_info->nr_async_submits);
861 
862         if (rw & REQ_SYNC)
863                 btrfs_set_work_high_priority(&async->work);
864 
865         btrfs_queue_work(fs_info->workers, &async->work);
866 
867         while (atomic_read(&fs_info->async_submit_draining) &&
868               atomic_read(&fs_info->nr_async_submits)) {
869                 wait_event(fs_info->async_submit_wait,
870                            (atomic_read(&fs_info->nr_async_submits) == 0));
871         }
872 
873         return 0;
874 }
875 
876 static int btree_csum_one_bio(struct bio *bio)
877 {
878         struct bio_vec *bvec;
879         struct btrfs_root *root;
880         int i, ret = 0;
881 
882         bio_for_each_segment_all(bvec, bio, i) {
883                 root = BTRFS_I(bvec->bv_page->mapping->host)->root;
884                 ret = csum_dirty_buffer(root, bvec->bv_page);
885                 if (ret)
886                         break;
887         }
888 
889         return ret;
890 }
891 
892 static int __btree_submit_bio_start(struct inode *inode, int rw,
893                                     struct bio *bio, int mirror_num,
894                                     unsigned long bio_flags,
895                                     u64 bio_offset)
896 {
897         /*
898          * when we're called for a write, we're already in the async
899          * submission context.  Just jump into btrfs_map_bio
900          */
901         return btree_csum_one_bio(bio);
902 }
903 
904 static int __btree_submit_bio_done(struct inode *inode, int rw, struct bio *bio,
905                                  int mirror_num, unsigned long bio_flags,
906                                  u64 bio_offset)
907 {
908         int ret;
909 
910         /*
911          * when we're called for a write, we're already in the async
912          * submission context.  Just jump into btrfs_map_bio
913          */
914         ret = btrfs_map_bio(BTRFS_I(inode)->root, rw, bio, mirror_num, 1);
915         if (ret)
916                 bio_endio(bio, ret);
917         return ret;
918 }
919 
920 static int check_async_write(struct inode *inode, unsigned long bio_flags)
921 {
922         if (bio_flags & EXTENT_BIO_TREE_LOG)
923                 return 0;
924 #ifdef CONFIG_X86
925         if (cpu_has_xmm4_2)
926                 return 0;
927 #endif
928         return 1;
929 }
930 
931 static int btree_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
932                                  int mirror_num, unsigned long bio_flags,
933                                  u64 bio_offset)
934 {
935         int async = check_async_write(inode, bio_flags);
936         int ret;
937 
938         if (!(rw & REQ_WRITE)) {
939                 /*
940                  * called for a read, do the setup so that checksum validation
941                  * can happen in the async kernel threads
942                  */
943                 ret = btrfs_bio_wq_end_io(BTRFS_I(inode)->root->fs_info,
944                                           bio, BTRFS_WQ_ENDIO_METADATA);
945                 if (ret)
946                         goto out_w_error;
947                 ret = btrfs_map_bio(BTRFS_I(inode)->root, rw, bio,
948                                     mirror_num, 0);
949         } else if (!async) {
950                 ret = btree_csum_one_bio(bio);
951                 if (ret)
952                         goto out_w_error;
953                 ret = btrfs_map_bio(BTRFS_I(inode)->root, rw, bio,
954                                     mirror_num, 0);
955         } else {
956                 /*
957                  * kthread helpers are used to submit writes so that
958                  * checksumming can happen in parallel across all CPUs
959                  */
960                 ret = btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
961                                           inode, rw, bio, mirror_num, 0,
962                                           bio_offset,
963                                           __btree_submit_bio_start,
964                                           __btree_submit_bio_done);
965         }
966 
967         if (ret) {
968 out_w_error:
969                 bio_endio(bio, ret);
970         }
971         return ret;
972 }
973 
974 #ifdef CONFIG_MIGRATION
975 static int btree_migratepage(struct address_space *mapping,
976                         struct page *newpage, struct page *page,
977                         enum migrate_mode mode)
978 {
979         /*
980          * we can't safely write a btree page from here,
981          * we haven't done the locking hook
982          */
983         if (PageDirty(page))
984                 return -EAGAIN;
985         /*
986          * Buffers may be managed in a filesystem specific way.
987          * We must have no buffers or drop them.
988          */
989         if (page_has_private(page) &&
990             !try_to_release_page(page, GFP_KERNEL))
991                 return -EAGAIN;
992         return migrate_page(mapping, newpage, page, mode);
993 }
994 #endif
995 
996 
997 static int btree_writepages(struct address_space *mapping,
998                             struct writeback_control *wbc)
999 {
1000         struct btrfs_fs_info *fs_info;
1001         int ret;
1002 
1003         if (wbc->sync_mode == WB_SYNC_NONE) {
1004 
1005                 if (wbc->for_kupdate)
1006                         return 0;
1007 
1008                 fs_info = BTRFS_I(mapping->host)->root->fs_info;
1009                 /* this is a bit racy, but that's ok */
1010                 ret = percpu_counter_compare(&fs_info->dirty_metadata_bytes,
1011                                              BTRFS_DIRTY_METADATA_THRESH);
1012                 if (ret < 0)
1013                         return 0;
1014         }
1015         return btree_write_cache_pages(mapping, wbc);
1016 }
1017 
1018 static int btree_readpage(struct file *file, struct page *page)
1019 {
1020         struct extent_io_tree *tree;
1021         tree = &BTRFS_I(page->mapping->host)->io_tree;
1022         return extent_read_full_page(tree, page, btree_get_extent, 0);
1023 }
1024 
1025 static int btree_releasepage(struct page *page, gfp_t gfp_flags)
1026 {
1027         if (PageWriteback(page) || PageDirty(page))
1028                 return 0;
1029 
1030         return try_release_extent_buffer(page);
1031 }
1032 
1033 static void btree_invalidatepage(struct page *page, unsigned int offset,
1034                                  unsigned int length)
1035 {
1036         struct extent_io_tree *tree;
1037         tree = &BTRFS_I(page->mapping->host)->io_tree;
1038         extent_invalidatepage(tree, page, offset);
1039         btree_releasepage(page, GFP_NOFS);
1040         if (PagePrivate(page)) {
1041                 btrfs_warn(BTRFS_I(page->mapping->host)->root->fs_info,
1042                            "page private not zero on page %llu",
1043                            (unsigned long long)page_offset(page));
1044                 ClearPagePrivate(page);
1045                 set_page_private(page, 0);
1046                 page_cache_release(page);
1047         }
1048 }
1049 
1050 static int btree_set_page_dirty(struct page *page)
1051 {
1052 #ifdef DEBUG
1053         struct extent_buffer *eb;
1054 
1055         BUG_ON(!PagePrivate(page));
1056         eb = (struct extent_buffer *)page->private;
1057         BUG_ON(!eb);
1058         BUG_ON(!test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags));
1059         BUG_ON(!atomic_read(&eb->refs));
1060         btrfs_assert_tree_locked(eb);
1061 #endif
1062         return __set_page_dirty_nobuffers(page);
1063 }
1064 
1065 static const struct address_space_operations btree_aops = {
1066         .readpage       = btree_readpage,
1067         .writepages     = btree_writepages,
1068         .releasepage    = btree_releasepage,
1069         .invalidatepage = btree_invalidatepage,
1070 #ifdef CONFIG_MIGRATION
1071         .migratepage    = btree_migratepage,
1072 #endif
1073         .set_page_dirty = btree_set_page_dirty,
1074 };
1075 
1076 void readahead_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize)
1077 {
1078         struct extent_buffer *buf = NULL;
1079         struct inode *btree_inode = root->fs_info->btree_inode;
1080 
1081         buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
1082         if (!buf)
1083                 return;
1084         read_extent_buffer_pages(&BTRFS_I(btree_inode)->io_tree,
1085                                  buf, 0, WAIT_NONE, btree_get_extent, 0);
1086         free_extent_buffer(buf);
1087 }
1088 
1089 int reada_tree_block_flagged(struct btrfs_root *root, u64 bytenr, u32 blocksize,
1090                          int mirror_num, struct extent_buffer **eb)
1091 {
1092         struct extent_buffer *buf = NULL;
1093         struct inode *btree_inode = root->fs_info->btree_inode;
1094         struct extent_io_tree *io_tree = &BTRFS_I(btree_inode)->io_tree;
1095         int ret;
1096 
1097         buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
1098         if (!buf)
1099                 return 0;
1100 
1101         set_bit(EXTENT_BUFFER_READAHEAD, &buf->bflags);
1102 
1103         ret = read_extent_buffer_pages(io_tree, buf, 0, WAIT_PAGE_LOCK,
1104                                        btree_get_extent, mirror_num);
1105         if (ret) {
1106                 free_extent_buffer(buf);
1107                 return ret;
1108         }
1109 
1110         if (test_bit(EXTENT_BUFFER_CORRUPT, &buf->bflags)) {
1111                 free_extent_buffer(buf);
1112                 return -EIO;
1113         } else if (extent_buffer_uptodate(buf)) {
1114                 *eb = buf;
1115         } else {
1116                 free_extent_buffer(buf);
1117         }
1118         return 0;
1119 }
1120 
1121 struct extent_buffer *btrfs_find_tree_block(struct btrfs_root *root,
1122                                             u64 bytenr)
1123 {
1124         return find_extent_buffer(root->fs_info, bytenr);
1125 }
1126 
1127 struct extent_buffer *btrfs_find_create_tree_block(struct btrfs_root *root,
1128                                                  u64 bytenr, u32 blocksize)
1129 {
1130         if (btrfs_test_is_dummy_root(root))
1131                 return alloc_test_extent_buffer(root->fs_info, bytenr,
1132                                                 blocksize);
1133         return alloc_extent_buffer(root->fs_info, bytenr, blocksize);
1134 }
1135 
1136 
1137 int btrfs_write_tree_block(struct extent_buffer *buf)
1138 {
1139         return filemap_fdatawrite_range(buf->pages[0]->mapping, buf->start,
1140                                         buf->start + buf->len - 1);
1141 }
1142 
1143 int btrfs_wait_tree_block_writeback(struct extent_buffer *buf)
1144 {
1145         return filemap_fdatawait_range(buf->pages[0]->mapping,
1146                                        buf->start, buf->start + buf->len - 1);
1147 }
1148 
1149 struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr,
1150                                       u64 parent_transid)
1151 {
1152         struct extent_buffer *buf = NULL;
1153         int ret;
1154 
1155         buf = btrfs_find_create_tree_block(root, bytenr, root->nodesize);
1156         if (!buf)
1157                 return NULL;
1158 
1159         ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
1160         if (ret) {
1161                 free_extent_buffer(buf);
1162                 return NULL;
1163         }
1164         return buf;
1165 
1166 }
1167 
1168 void clean_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
1169                       struct extent_buffer *buf)
1170 {
1171         struct btrfs_fs_info *fs_info = root->fs_info;
1172 
1173         if (btrfs_header_generation(buf) ==
1174             fs_info->running_transaction->transid) {
1175                 btrfs_assert_tree_locked(buf);
1176 
1177                 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &buf->bflags)) {
1178                         __percpu_counter_add(&fs_info->dirty_metadata_bytes,
1179                                              -buf->len,
1180                                              fs_info->dirty_metadata_batch);
1181                         /* ugh, clear_extent_buffer_dirty needs to lock the page */
1182                         btrfs_set_lock_blocking(buf);
1183                         clear_extent_buffer_dirty(buf);
1184                 }
1185         }
1186 }
1187 
1188 static struct btrfs_subvolume_writers *btrfs_alloc_subvolume_writers(void)
1189 {
1190         struct btrfs_subvolume_writers *writers;
1191         int ret;
1192 
1193         writers = kmalloc(sizeof(*writers), GFP_NOFS);
1194         if (!writers)
1195                 return ERR_PTR(-ENOMEM);
1196 
1197         ret = percpu_counter_init(&writers->counter, 0, GFP_NOFS);
1198         if (ret < 0) {
1199                 kfree(writers);
1200                 return ERR_PTR(ret);
1201         }
1202 
1203         init_waitqueue_head(&writers->wait);
1204         return writers;
1205 }
1206 
1207 static void
1208 btrfs_free_subvolume_writers(struct btrfs_subvolume_writers *writers)
1209 {
1210         percpu_counter_destroy(&writers->counter);
1211         kfree(writers);
1212 }
1213 
1214 static void __setup_root(u32 nodesize, u32 sectorsize, u32 stripesize,
1215                          struct btrfs_root *root, struct btrfs_fs_info *fs_info,
1216                          u64 objectid)
1217 {
1218         root->node = NULL;
1219         root->commit_root = NULL;
1220         root->sectorsize = sectorsize;
1221         root->nodesize = nodesize;
1222         root->stripesize = stripesize;
1223         root->state = 0;
1224         root->orphan_cleanup_state = 0;
1225 
1226         root->objectid = objectid;
1227         root->last_trans = 0;
1228         root->highest_objectid = 0;
1229         root->nr_delalloc_inodes = 0;
1230         root->nr_ordered_extents = 0;
1231         root->name = NULL;
1232         root->inode_tree = RB_ROOT;
1233         INIT_RADIX_TREE(&root->delayed_nodes_tree, GFP_ATOMIC);
1234         root->block_rsv = NULL;
1235         root->orphan_block_rsv = NULL;
1236 
1237         INIT_LIST_HEAD(&root->dirty_list);
1238         INIT_LIST_HEAD(&root->root_list);
1239         INIT_LIST_HEAD(&root->delalloc_inodes);
1240         INIT_LIST_HEAD(&root->delalloc_root);
1241         INIT_LIST_HEAD(&root->ordered_extents);
1242         INIT_LIST_HEAD(&root->ordered_root);
1243         INIT_LIST_HEAD(&root->logged_list[0]);
1244         INIT_LIST_HEAD(&root->logged_list[1]);
1245         spin_lock_init(&root->orphan_lock);
1246         spin_lock_init(&root->inode_lock);
1247         spin_lock_init(&root->delalloc_lock);
1248         spin_lock_init(&root->ordered_extent_lock);
1249         spin_lock_init(&root->accounting_lock);
1250         spin_lock_init(&root->log_extents_lock[0]);
1251         spin_lock_init(&root->log_extents_lock[1]);
1252         mutex_init(&root->objectid_mutex);
1253         mutex_init(&root->log_mutex);
1254         mutex_init(&root->ordered_extent_mutex);
1255         mutex_init(&root->delalloc_mutex);
1256         init_waitqueue_head(&root->log_writer_wait);
1257         init_waitqueue_head(&root->log_commit_wait[0]);
1258         init_waitqueue_head(&root->log_commit_wait[1]);
1259         INIT_LIST_HEAD(&root->log_ctxs[0]);
1260         INIT_LIST_HEAD(&root->log_ctxs[1]);
1261         atomic_set(&root->log_commit[0], 0);
1262         atomic_set(&root->log_commit[1], 0);
1263         atomic_set(&root->log_writers, 0);
1264         atomic_set(&root->log_batch, 0);
1265         atomic_set(&root->orphan_inodes, 0);
1266         atomic_set(&root->refs, 1);
1267         atomic_set(&root->will_be_snapshoted, 0);
1268         root->log_transid = 0;
1269         root->log_transid_committed = -1;
1270         root->last_log_commit = 0;
1271         if (fs_info)
1272                 extent_io_tree_init(&root->dirty_log_pages,
1273                                      fs_info->btree_inode->i_mapping);
1274 
1275         memset(&root->root_key, 0, sizeof(root->root_key));
1276         memset(&root->root_item, 0, sizeof(root->root_item));
1277         memset(&root->defrag_progress, 0, sizeof(root->defrag_progress));
1278         memset(&root->root_kobj, 0, sizeof(root->root_kobj));
1279         if (fs_info)
1280                 root->defrag_trans_start = fs_info->generation;
1281         else
1282                 root->defrag_trans_start = 0;
1283         init_completion(&root->kobj_unregister);
1284         root->root_key.objectid = objectid;
1285         root->anon_dev = 0;
1286 
1287         spin_lock_init(&root->root_item_lock);
1288 }
1289 
1290 static struct btrfs_root *btrfs_alloc_root(struct btrfs_fs_info *fs_info)
1291 {
1292         struct btrfs_root *root = kzalloc(sizeof(*root), GFP_NOFS);
1293         if (root)
1294                 root->fs_info = fs_info;
1295         return root;
1296 }
1297 
1298 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
1299 /* Should only be used by the testing infrastructure */
1300 struct btrfs_root *btrfs_alloc_dummy_root(void)
1301 {
1302         struct btrfs_root *root;
1303 
1304         root = btrfs_alloc_root(NULL);
1305         if (!root)
1306                 return ERR_PTR(-ENOMEM);
1307         __setup_root(4096, 4096, 4096, root, NULL, 1);
1308         set_bit(BTRFS_ROOT_DUMMY_ROOT, &root->state);
1309         root->alloc_bytenr = 0;
1310 
1311         return root;
1312 }
1313 #endif
1314 
1315 struct btrfs_root *btrfs_create_tree(struct btrfs_trans_handle *trans,
1316                                      struct btrfs_fs_info *fs_info,
1317                                      u64 objectid)
1318 {
1319         struct extent_buffer *leaf;
1320         struct btrfs_root *tree_root = fs_info->tree_root;
1321         struct btrfs_root *root;
1322         struct btrfs_key key;
1323         int ret = 0;
1324         uuid_le uuid;
1325 
1326         root = btrfs_alloc_root(fs_info);
1327         if (!root)
1328                 return ERR_PTR(-ENOMEM);
1329 
1330         __setup_root(tree_root->nodesize, tree_root->sectorsize,
1331                 tree_root->stripesize, root, fs_info, objectid);
1332         root->root_key.objectid = objectid;
1333         root->root_key.type = BTRFS_ROOT_ITEM_KEY;
1334         root->root_key.offset = 0;
1335 
1336         leaf = btrfs_alloc_tree_block(trans, root, 0, objectid, NULL, 0, 0, 0);
1337         if (IS_ERR(leaf)) {
1338                 ret = PTR_ERR(leaf);
1339                 leaf = NULL;
1340                 goto fail;
1341         }
1342 
1343         memset_extent_buffer(leaf, 0, 0, sizeof(struct btrfs_header));
1344         btrfs_set_header_bytenr(leaf, leaf->start);
1345         btrfs_set_header_generation(leaf, trans->transid);
1346         btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV);
1347         btrfs_set_header_owner(leaf, objectid);
1348         root->node = leaf;
1349 
1350         write_extent_buffer(leaf, fs_info->fsid, btrfs_header_fsid(),
1351                             BTRFS_FSID_SIZE);
1352         write_extent_buffer(leaf, fs_info->chunk_tree_uuid,
1353                             btrfs_header_chunk_tree_uuid(leaf),
1354                             BTRFS_UUID_SIZE);
1355         btrfs_mark_buffer_dirty(leaf);
1356 
1357         root->commit_root = btrfs_root_node(root);
1358         set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
1359 
1360         root->root_item.flags = 0;
1361         root->root_item.byte_limit = 0;
1362         btrfs_set_root_bytenr(&root->root_item, leaf->start);
1363         btrfs_set_root_generation(&root->root_item, trans->transid);
1364         btrfs_set_root_level(&root->root_item, 0);
1365         btrfs_set_root_refs(&root->root_item, 1);
1366         btrfs_set_root_used(&root->root_item, leaf->len);
1367         btrfs_set_root_last_snapshot(&root->root_item, 0);
1368         btrfs_set_root_dirid(&root->root_item, 0);
1369         uuid_le_gen(&uuid);
1370         memcpy(root->root_item.uuid, uuid.b, BTRFS_UUID_SIZE);
1371         root->root_item.drop_level = 0;
1372 
1373         key.objectid = objectid;
1374         key.type = BTRFS_ROOT_ITEM_KEY;
1375         key.offset = 0;
1376         ret = btrfs_insert_root(trans, tree_root, &key, &root->root_item);
1377         if (ret)
1378                 goto fail;
1379 
1380         btrfs_tree_unlock(leaf);
1381 
1382         return root;
1383 
1384 fail:
1385         if (leaf) {
1386                 btrfs_tree_unlock(leaf);
1387                 free_extent_buffer(root->commit_root);
1388                 free_extent_buffer(leaf);
1389         }
1390         kfree(root);
1391 
1392         return ERR_PTR(ret);
1393 }
1394 
1395 static struct btrfs_root *alloc_log_tree(struct btrfs_trans_handle *trans,
1396                                          struct btrfs_fs_info *fs_info)
1397 {
1398         struct btrfs_root *root;
1399         struct btrfs_root *tree_root = fs_info->tree_root;
1400         struct extent_buffer *leaf;
1401 
1402         root = btrfs_alloc_root(fs_info);
1403         if (!root)
1404                 return ERR_PTR(-ENOMEM);
1405 
1406         __setup_root(tree_root->nodesize, tree_root->sectorsize,
1407                      tree_root->stripesize, root, fs_info,
1408                      BTRFS_TREE_LOG_OBJECTID);
1409 
1410         root->root_key.objectid = BTRFS_TREE_LOG_OBJECTID;
1411         root->root_key.type = BTRFS_ROOT_ITEM_KEY;
1412         root->root_key.offset = BTRFS_TREE_LOG_OBJECTID;
1413 
1414         /*
1415          * DON'T set REF_COWS for log trees
1416          *
1417          * log trees do not get reference counted because they go away
1418          * before a real commit is actually done.  They do store pointers
1419          * to file data extents, and those reference counts still get
1420          * updated (along with back refs to the log tree).
1421          */
1422 
1423         leaf = btrfs_alloc_tree_block(trans, root, 0, BTRFS_TREE_LOG_OBJECTID,
1424                         NULL, 0, 0, 0);
1425         if (IS_ERR(leaf)) {
1426                 kfree(root);
1427                 return ERR_CAST(leaf);
1428         }
1429 
1430         memset_extent_buffer(leaf, 0, 0, sizeof(struct btrfs_header));
1431         btrfs_set_header_bytenr(leaf, leaf->start);
1432         btrfs_set_header_generation(leaf, trans->transid);
1433         btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV);
1434         btrfs_set_header_owner(leaf, BTRFS_TREE_LOG_OBJECTID);
1435         root->node = leaf;
1436 
1437         write_extent_buffer(root->node, root->fs_info->fsid,
1438                             btrfs_header_fsid(), BTRFS_FSID_SIZE);
1439         btrfs_mark_buffer_dirty(root->node);
1440         btrfs_tree_unlock(root->node);
1441         return root;
1442 }
1443 
1444 int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
1445                              struct btrfs_fs_info *fs_info)
1446 {
1447         struct btrfs_root *log_root;
1448 
1449         log_root = alloc_log_tree(trans, fs_info);
1450         if (IS_ERR(log_root))
1451                 return PTR_ERR(log_root);
1452         WARN_ON(fs_info->log_root_tree);
1453         fs_info->log_root_tree = log_root;
1454         return 0;
1455 }
1456 
1457 int btrfs_add_log_tree(struct btrfs_trans_handle *trans,
1458                        struct btrfs_root *root)
1459 {
1460         struct btrfs_root *log_root;
1461         struct btrfs_inode_item *inode_item;
1462 
1463         log_root = alloc_log_tree(trans, root->fs_info);
1464         if (IS_ERR(log_root))
1465                 return PTR_ERR(log_root);
1466 
1467         log_root->last_trans = trans->transid;
1468         log_root->root_key.offset = root->root_key.objectid;
1469 
1470         inode_item = &log_root->root_item.inode;
1471         btrfs_set_stack_inode_generation(inode_item, 1);
1472         btrfs_set_stack_inode_size(inode_item, 3);
1473         btrfs_set_stack_inode_nlink(inode_item, 1);
1474         btrfs_set_stack_inode_nbytes(inode_item, root->nodesize);
1475         btrfs_set_stack_inode_mode(inode_item, S_IFDIR | 0755);
1476 
1477         btrfs_set_root_node(&log_root->root_item, log_root->node);
1478 
1479         WARN_ON(root->log_root);
1480         root->log_root = log_root;
1481         root->log_transid = 0;
1482         root->log_transid_committed = -1;
1483         root->last_log_commit = 0;
1484         return 0;
1485 }
1486 
1487 static struct btrfs_root *btrfs_read_tree_root(struct btrfs_root *tree_root,
1488                                                struct btrfs_key *key)
1489 {
1490         struct btrfs_root *root;
1491         struct btrfs_fs_info *fs_info = tree_root->fs_info;
1492         struct btrfs_path *path;
1493         u64 generation;
1494         int ret;
1495 
1496         path = btrfs_alloc_path();
1497         if (!path)
1498                 return ERR_PTR(-ENOMEM);
1499 
1500         root = btrfs_alloc_root(fs_info);
1501         if (!root) {
1502                 ret = -ENOMEM;
1503                 goto alloc_fail;
1504         }
1505 
1506         __setup_root(tree_root->nodesize, tree_root->sectorsize,
1507                 tree_root->stripesize, root, fs_info, key->objectid);
1508 
1509         ret = btrfs_find_root(tree_root, key, path,
1510                               &root->root_item, &root->root_key);
1511         if (ret) {
1512                 if (ret > 0)
1513                         ret = -ENOENT;
1514                 goto find_fail;
1515         }
1516 
1517         generation = btrfs_root_generation(&root->root_item);
1518         root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
1519                                      generation);
1520         if (!root->node) {
1521                 ret = -ENOMEM;
1522                 goto find_fail;
1523         } else if (!btrfs_buffer_uptodate(root->node, generation, 0)) {
1524                 ret = -EIO;
1525                 goto read_fail;
1526         }
1527         root->commit_root = btrfs_root_node(root);
1528 out:
1529         btrfs_free_path(path);
1530         return root;
1531 
1532 read_fail:
1533         free_extent_buffer(root->node);
1534 find_fail:
1535         kfree(root);
1536 alloc_fail:
1537         root = ERR_PTR(ret);
1538         goto out;
1539 }
1540 
1541 struct btrfs_root *btrfs_read_fs_root(struct btrfs_root *tree_root,
1542                                       struct btrfs_key *location)
1543 {
1544         struct btrfs_root *root;
1545 
1546         root = btrfs_read_tree_root(tree_root, location);
1547         if (IS_ERR(root))
1548                 return root;
1549 
1550         if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) {
1551                 set_bit(BTRFS_ROOT_REF_COWS, &root->state);
1552                 btrfs_check_and_init_root_item(&root->root_item);
1553         }
1554 
1555         return root;
1556 }
1557 
1558 int btrfs_init_fs_root(struct btrfs_root *root)
1559 {
1560         int ret;
1561         struct btrfs_subvolume_writers *writers;
1562 
1563         root->free_ino_ctl = kzalloc(sizeof(*root->free_ino_ctl), GFP_NOFS);
1564         root->free_ino_pinned = kzalloc(sizeof(*root->free_ino_pinned),
1565                                         GFP_NOFS);
1566         if (!root->free_ino_pinned || !root->free_ino_ctl) {
1567                 ret = -ENOMEM;
1568                 goto fail;
1569         }
1570 
1571         writers = btrfs_alloc_subvolume_writers();
1572         if (IS_ERR(writers)) {
1573                 ret = PTR_ERR(writers);
1574                 goto fail;
1575         }
1576         root->subv_writers = writers;
1577 
1578         btrfs_init_free_ino_ctl(root);
1579         spin_lock_init(&root->ino_cache_lock);
1580         init_waitqueue_head(&root->ino_cache_wait);
1581 
1582         ret = get_anon_bdev(&root->anon_dev);
1583         if (ret)
1584                 goto free_writers;
1585         return 0;
1586 
1587 free_writers:
1588         btrfs_free_subvolume_writers(root->subv_writers);
1589 fail:
1590         kfree(root->free_ino_ctl);
1591         kfree(root->free_ino_pinned);
1592         return ret;
1593 }
1594 
1595 static struct btrfs_root *btrfs_lookup_fs_root(struct btrfs_fs_info *fs_info,
1596                                                u64 root_id)
1597 {
1598         struct btrfs_root *root;
1599 
1600         spin_lock(&fs_info->fs_roots_radix_lock);
1601         root = radix_tree_lookup(&fs_info->fs_roots_radix,
1602                                  (unsigned long)root_id);
1603         spin_unlock(&fs_info->fs_roots_radix_lock);
1604         return root;
1605 }
1606 
1607 int btrfs_insert_fs_root(struct btrfs_fs_info *fs_info,
1608                          struct btrfs_root *root)
1609 {
1610         int ret;
1611 
1612         ret = radix_tree_preload(GFP_NOFS & ~__GFP_HIGHMEM);
1613         if (ret)
1614                 return ret;
1615 
1616         spin_lock(&fs_info->fs_roots_radix_lock);
1617         ret = radix_tree_insert(&fs_info->fs_roots_radix,
1618                                 (unsigned long)root->root_key.objectid,
1619                                 root);
1620         if (ret == 0)
1621                 set_bit(BTRFS_ROOT_IN_RADIX, &root->state);
1622         spin_unlock(&fs_info->fs_roots_radix_lock);
1623         radix_tree_preload_end();
1624 
1625         return ret;
1626 }
1627 
1628 struct btrfs_root *btrfs_get_fs_root(struct btrfs_fs_info *fs_info,
1629                                      struct btrfs_key *location,
1630                                      bool check_ref)
1631 {
1632         struct btrfs_root *root;
1633         struct btrfs_path *path;
1634         int ret;
1635 
1636         if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
1637                 return fs_info->tree_root;
1638         if (location->objectid == BTRFS_EXTENT_TREE_OBJECTID)
1639                 return fs_info->extent_root;
1640         if (location->objectid == BTRFS_CHUNK_TREE_OBJECTID)
1641                 return fs_info->chunk_root;
1642         if (location->objectid == BTRFS_DEV_TREE_OBJECTID)
1643                 return fs_info->dev_root;
1644         if (location->objectid == BTRFS_CSUM_TREE_OBJECTID)
1645                 return fs_info->csum_root;
1646         if (location->objectid == BTRFS_QUOTA_TREE_OBJECTID)
1647                 return fs_info->quota_root ? fs_info->quota_root :
1648                                              ERR_PTR(-ENOENT);
1649         if (location->objectid == BTRFS_UUID_TREE_OBJECTID)
1650                 return fs_info->uuid_root ? fs_info->uuid_root :
1651                                             ERR_PTR(-ENOENT);
1652 again:
1653         root = btrfs_lookup_fs_root(fs_info, location->objectid);
1654         if (root) {
1655                 if (check_ref && btrfs_root_refs(&root->root_item) == 0)
1656                         return ERR_PTR(-ENOENT);
1657                 return root;
1658         }
1659 
1660         root = btrfs_read_fs_root(fs_info->tree_root, location);
1661         if (IS_ERR(root))
1662                 return root;
1663 
1664         if (check_ref && btrfs_root_refs(&root->root_item) == 0) {
1665                 ret = -ENOENT;
1666                 goto fail;
1667         }
1668 
1669         ret = btrfs_init_fs_root(root);
1670         if (ret)
1671                 goto fail;
1672 
1673         path = btrfs_alloc_path();
1674         if (!path) {
1675                 ret = -ENOMEM;
1676                 goto fail;
1677         }
1678         ret = btrfs_find_item(fs_info->tree_root, path, BTRFS_ORPHAN_OBJECTID,
1679                         location->objectid, BTRFS_ORPHAN_ITEM_KEY, NULL);
1680         btrfs_free_path(path);
1681         if (ret < 0)
1682                 goto fail;
1683         if (ret == 0)
1684                 set_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state);
1685 
1686         ret = btrfs_insert_fs_root(fs_info, root);
1687         if (ret) {
1688                 if (ret == -EEXIST) {
1689                         free_fs_root(root);
1690                         goto again;
1691                 }
1692                 goto fail;
1693         }
1694         return root;
1695 fail:
1696         free_fs_root(root);
1697         return ERR_PTR(ret);
1698 }
1699 
1700 static int btrfs_congested_fn(void *congested_data, int bdi_bits)
1701 {
1702         struct btrfs_fs_info *info = (struct btrfs_fs_info *)congested_data;
1703         int ret = 0;
1704         struct btrfs_device *device;
1705         struct backing_dev_info *bdi;
1706 
1707         rcu_read_lock();
1708         list_for_each_entry_rcu(device, &info->fs_devices->devices, dev_list) {
1709                 if (!device->bdev)
1710                         continue;
1711                 bdi = blk_get_backing_dev_info(device->bdev);
1712                 if (bdi_congested(bdi, bdi_bits)) {
1713                         ret = 1;
1714                         break;
1715                 }
1716         }
1717         rcu_read_unlock();
1718         return ret;
1719 }
1720 
1721 static int setup_bdi(struct btrfs_fs_info *info, struct backing_dev_info *bdi)
1722 {
1723         int err;
1724 
1725         bdi->capabilities = BDI_CAP_MAP_COPY;
1726         err = bdi_setup_and_register(bdi, "btrfs", BDI_CAP_MAP_COPY);
1727         if (err)
1728                 return err;
1729 
1730         bdi->ra_pages   = default_backing_dev_info.ra_pages;
1731         bdi->congested_fn       = btrfs_congested_fn;
1732         bdi->congested_data     = info;
1733         return 0;
1734 }
1735 
1736 /*
1737  * called by the kthread helper functions to finally call the bio end_io
1738  * functions.  This is where read checksum verification actually happens
1739  */
1740 static void end_workqueue_fn(struct btrfs_work *work)
1741 {
1742         struct bio *bio;
1743         struct btrfs_end_io_wq *end_io_wq;
1744         int error;
1745 
1746         end_io_wq = container_of(work, struct btrfs_end_io_wq, work);
1747         bio = end_io_wq->bio;
1748 
1749         error = end_io_wq->error;
1750         bio->bi_private = end_io_wq->private;
1751         bio->bi_end_io = end_io_wq->end_io;
1752         kmem_cache_free(btrfs_end_io_wq_cache, end_io_wq);
1753         bio_endio_nodec(bio, error);
1754 }
1755 
1756 static int cleaner_kthread(void *arg)
1757 {
1758         struct btrfs_root *root = arg;
1759         int again;
1760 
1761         do {
1762                 again = 0;
1763 
1764                 /* Make the cleaner go to sleep early. */
1765                 if (btrfs_need_cleaner_sleep(root))
1766                         goto sleep;
1767 
1768                 if (!mutex_trylock(&root->fs_info->cleaner_mutex))
1769                         goto sleep;
1770 
1771                 /*
1772                  * Avoid the problem that we change the status of the fs
1773                  * during the above check and trylock.
1774                  */
1775                 if (btrfs_need_cleaner_sleep(root)) {
1776                         mutex_unlock(&root->fs_info->cleaner_mutex);
1777                         goto sleep;
1778                 }
1779 
1780                 btrfs_run_delayed_iputs(root);
1781                 btrfs_delete_unused_bgs(root->fs_info);
1782                 again = btrfs_clean_one_deleted_snapshot(root);
1783                 mutex_unlock(&root->fs_info->cleaner_mutex);
1784 
1785                 /*
1786                  * The defragger has dealt with the R/O remount and umount,
1787                  * needn't do anything special here.
1788                  */
1789                 btrfs_run_defrag_inodes(root->fs_info);
1790 sleep:
1791                 if (!try_to_freeze() && !again) {
1792                         set_current_state(TASK_INTERRUPTIBLE);
1793                         if (!kthread_should_stop())
1794                                 schedule();
1795                         __set_current_state(TASK_RUNNING);
1796                 }
1797         } while (!kthread_should_stop());
1798         return 0;
1799 }
1800 
1801 static int transaction_kthread(void *arg)
1802 {
1803         struct btrfs_root *root = arg;
1804         struct btrfs_trans_handle *trans;
1805         struct btrfs_transaction *cur;
1806         u64 transid;
1807         unsigned long now;
1808         unsigned long delay;
1809         bool cannot_commit;
1810 
1811         do {
1812                 cannot_commit = false;
1813                 delay = HZ * root->fs_info->commit_interval;
1814                 mutex_lock(&root->fs_info->transaction_kthread_mutex);
1815 
1816                 spin_lock(&root->fs_info->trans_lock);
1817                 cur = root->fs_info->running_transaction;
1818                 if (!cur) {
1819                         spin_unlock(&root->fs_info->trans_lock);
1820                         goto sleep;
1821                 }
1822 
1823                 now = get_seconds();
1824                 if (cur->state < TRANS_STATE_BLOCKED &&
1825                     (now < cur->start_time ||
1826                      now - cur->start_time < root->fs_info->commit_interval)) {
1827                         spin_unlock(&root->fs_info->trans_lock);
1828                         delay = HZ * 5;
1829                         goto sleep;
1830                 }
1831                 transid = cur->transid;
1832                 spin_unlock(&root->fs_info->trans_lock);
1833 
1834                 /* If the file system is aborted, this will always fail. */
1835                 trans = btrfs_attach_transaction(root);
1836                 if (IS_ERR(trans)) {
1837                         if (PTR_ERR(trans) != -ENOENT)
1838                                 cannot_commit = true;
1839                         goto sleep;
1840                 }
1841                 if (transid == trans->transid) {
1842                         btrfs_commit_transaction(trans, root);
1843                 } else {
1844                         btrfs_end_transaction(trans, root);
1845                 }
1846 sleep:
1847                 wake_up_process(root->fs_info->cleaner_kthread);
1848                 mutex_unlock(&root->fs_info->transaction_kthread_mutex);
1849 
1850                 if (unlikely(test_bit(BTRFS_FS_STATE_ERROR,
1851                                       &root->fs_info->fs_state)))
1852                         btrfs_cleanup_transaction(root);
1853                 if (!try_to_freeze()) {
1854                         set_current_state(TASK_INTERRUPTIBLE);
1855                         if (!kthread_should_stop() &&
1856                             (!btrfs_transaction_blocked(root->fs_info) ||
1857                              cannot_commit))
1858                                 schedule_timeout(delay);
1859                         __set_current_state(TASK_RUNNING);
1860                 }
1861         } while (!kthread_should_stop());
1862         return 0;
1863 }
1864 
1865 /*
1866  * this will find the highest generation in the array of
1867  * root backups.  The index of the highest array is returned,
1868  * or -1 if we can't find anything.
1869  *
1870  * We check to make sure the array is valid by comparing the
1871  * generation of the latest  root in the array with the generation
1872  * in the super block.  If they don't match we pitch it.
1873  */
1874 static int find_newest_super_backup(struct btrfs_fs_info *info, u64 newest_gen)
1875 {
1876         u64 cur;
1877         int newest_index = -1;
1878         struct btrfs_root_backup *root_backup;
1879         int i;
1880 
1881         for (i = 0; i < BTRFS_NUM_BACKUP_ROOTS; i++) {
1882                 root_backup = info->super_copy->super_roots + i;
1883                 cur = btrfs_backup_tree_root_gen(root_backup);
1884                 if (cur == newest_gen)
1885                         newest_index = i;
1886         }
1887 
1888         /* check to see if we actually wrapped around */
1889         if (newest_index == BTRFS_NUM_BACKUP_ROOTS - 1) {
1890                 root_backup = info->super_copy->super_roots;
1891                 cur = btrfs_backup_tree_root_gen(root_backup);
1892                 if (cur == newest_gen)
1893                         newest_index = 0;
1894         }
1895         return newest_index;
1896 }
1897 
1898 
1899 /*
1900  * find the oldest backup so we know where to store new entries
1901  * in the backup array.  This will set the backup_root_index
1902  * field in the fs_info struct
1903  */
1904 static void find_oldest_super_backup(struct btrfs_fs_info *info,
1905                                      u64 newest_gen)
1906 {
1907         int newest_index = -1;
1908 
1909         newest_index = find_newest_super_backup(info, newest_gen);
1910         /* if there was garbage in there, just move along */
1911         if (newest_index == -1) {
1912                 info->backup_root_index = 0;
1913         } else {
1914                 info->backup_root_index = (newest_index + 1) % BTRFS_NUM_BACKUP_ROOTS;
1915         }
1916 }
1917 
1918 /*
1919  * copy all the root pointers into the super backup array.
1920  * this will bump the backup pointer by one when it is
1921  * done
1922  */
1923 static void backup_super_roots(struct btrfs_fs_info *info)
1924 {
1925         int next_backup;
1926         struct btrfs_root_backup *root_backup;
1927         int last_backup;
1928 
1929         next_backup = info->backup_root_index;
1930         last_backup = (next_backup + BTRFS_NUM_BACKUP_ROOTS - 1) %
1931                 BTRFS_NUM_BACKUP_ROOTS;
1932 
1933         /*
1934          * just overwrite the last backup if we're at the same generation
1935          * this happens only at umount
1936          */
1937         root_backup = info->super_for_commit->super_roots + last_backup;
1938         if (btrfs_backup_tree_root_gen(root_backup) ==
1939             btrfs_header_generation(info->tree_root->node))
1940                 next_backup = last_backup;
1941 
1942         root_backup = info->super_for_commit->super_roots + next_backup;
1943 
1944         /*
1945          * make sure all of our padding and empty slots get zero filled
1946          * regardless of which ones we use today
1947          */
1948         memset(root_backup, 0, sizeof(*root_backup));
1949 
1950         info->backup_root_index = (next_backup + 1) % BTRFS_NUM_BACKUP_ROOTS;
1951 
1952         btrfs_set_backup_tree_root(root_backup, info->tree_root->node->start);
1953         btrfs_set_backup_tree_root_gen(root_backup,
1954                                btrfs_header_generation(info->tree_root->node));
1955 
1956         btrfs_set_backup_tree_root_level(root_backup,
1957                                btrfs_header_level(info->tree_root->node));
1958 
1959         btrfs_set_backup_chunk_root(root_backup, info->chunk_root->node->start);
1960         btrfs_set_backup_chunk_root_gen(root_backup,
1961                                btrfs_header_generation(info->chunk_root->node));
1962         btrfs_set_backup_chunk_root_level(root_backup,
1963                                btrfs_header_level(info->chunk_root->node));
1964 
1965         btrfs_set_backup_extent_root(root_backup, info->extent_root->node->start);
1966         btrfs_set_backup_extent_root_gen(root_backup,
1967                                btrfs_header_generation(info->extent_root->node));
1968         btrfs_set_backup_extent_root_level(root_backup,
1969                                btrfs_header_level(info->extent_root->node));
1970 
1971         /*
1972          * we might commit during log recovery, which happens before we set
1973          * the fs_root.  Make sure it is valid before we fill it in.
1974          */
1975         if (info->fs_root && info->fs_root->node) {
1976                 btrfs_set_backup_fs_root(root_backup,
1977                                          info->fs_root->node->start);
1978                 btrfs_set_backup_fs_root_gen(root_backup,
1979                                btrfs_header_generation(info->fs_root->node));
1980                 btrfs_set_backup_fs_root_level(root_backup,
1981                                btrfs_header_level(info->fs_root->node));
1982         }
1983 
1984         btrfs_set_backup_dev_root(root_backup, info->dev_root->node->start);
1985         btrfs_set_backup_dev_root_gen(root_backup,
1986                                btrfs_header_generation(info->dev_root->node));
1987         btrfs_set_backup_dev_root_level(root_backup,
1988                                        btrfs_header_level(info->dev_root->node));
1989 
1990         btrfs_set_backup_csum_root(root_backup, info->csum_root->node->start);
1991         btrfs_set_backup_csum_root_gen(root_backup,
1992                                btrfs_header_generation(info->csum_root->node));
1993         btrfs_set_backup_csum_root_level(root_backup,
1994                                btrfs_header_level(info->csum_root->node));
1995 
1996         btrfs_set_backup_total_bytes(root_backup,
1997                              btrfs_super_total_bytes(info->super_copy));
1998         btrfs_set_backup_bytes_used(root_backup,
1999                              btrfs_super_bytes_used(info->super_copy));
2000         btrfs_set_backup_num_devices(root_backup,
2001                              btrfs_super_num_devices(info->super_copy));
2002 
2003         /*
2004          * if we don't copy this out to the super_copy, it won't get remembered
2005          * for the next commit
2006          */
2007         memcpy(&info->super_copy->super_roots,
2008                &info->super_for_commit->super_roots,
2009                sizeof(*root_backup) * BTRFS_NUM_BACKUP_ROOTS);
2010 }
2011 
2012 /*
2013  * this copies info out of the root backup array and back into
2014  * the in-memory super block.  It is meant to help iterate through
2015  * the array, so you send it the number of backups you've already
2016  * tried and the last backup index you used.
2017  *
2018  * this returns -1 when it has tried all the backups
2019  */
2020 static noinline int next_root_backup(struct btrfs_fs_info *info,
2021                                      struct btrfs_super_block *super,
2022                                      int *num_backups_tried, int *backup_index)
2023 {
2024         struct btrfs_root_backup *root_backup;
2025         int newest = *backup_index;
2026 
2027         if (*num_backups_tried == 0) {
2028                 u64 gen = btrfs_super_generation(super);
2029 
2030                 newest = find_newest_super_backup(info, gen);
2031                 if (newest == -1)
2032                         return -1;
2033 
2034                 *backup_index = newest;
2035                 *num_backups_tried = 1;
2036         } else if (*num_backups_tried == BTRFS_NUM_BACKUP_ROOTS) {
2037                 /* we've tried all the backups, all done */
2038                 return -1;
2039         } else {
2040                 /* jump to the next oldest backup */
2041                 newest = (*backup_index + BTRFS_NUM_BACKUP_ROOTS - 1) %
2042                         BTRFS_NUM_BACKUP_ROOTS;
2043                 *backup_index = newest;
2044                 *num_backups_tried += 1;
2045         }
2046         root_backup = super->super_roots + newest;
2047 
2048         btrfs_set_super_generation(super,
2049                                    btrfs_backup_tree_root_gen(root_backup));
2050         btrfs_set_super_root(super, btrfs_backup_tree_root(root_backup));
2051         btrfs_set_super_root_level(super,
2052                                    btrfs_backup_tree_root_level(root_backup));
2053         btrfs_set_super_bytes_used(super, btrfs_backup_bytes_used(root_backup));
2054 
2055         /*
2056          * fixme: the total bytes and num_devices need to match or we should
2057          * need a fsck
2058          */
2059         btrfs_set_super_total_bytes(super, btrfs_backup_total_bytes(root_backup));
2060         btrfs_set_super_num_devices(super, btrfs_backup_num_devices(root_backup));
2061         return 0;
2062 }
2063 
2064 /* helper to cleanup workers */
2065 static void btrfs_stop_all_workers(struct btrfs_fs_info *fs_info)
2066 {
2067         btrfs_destroy_workqueue(fs_info->fixup_workers);
2068         btrfs_destroy_workqueue(fs_info->delalloc_workers);
2069         btrfs_destroy_workqueue(fs_info->workers);
2070         btrfs_destroy_workqueue(fs_info->endio_workers);
2071         btrfs_destroy_workqueue(fs_info->endio_meta_workers);
2072         btrfs_destroy_workqueue(fs_info->endio_raid56_workers);
2073         btrfs_destroy_workqueue(fs_info->endio_repair_workers);
2074         btrfs_destroy_workqueue(fs_info->rmw_workers);
2075         btrfs_destroy_workqueue(fs_info->endio_meta_write_workers);
2076         btrfs_destroy_workqueue(fs_info->endio_write_workers);
2077         btrfs_destroy_workqueue(fs_info->endio_freespace_worker);
2078         btrfs_destroy_workqueue(fs_info->submit_workers);
2079         btrfs_destroy_workqueue(fs_info->delayed_workers);
2080         btrfs_destroy_workqueue(fs_info->caching_workers);
2081         btrfs_destroy_workqueue(fs_info->readahead_workers);
2082         btrfs_destroy_workqueue(fs_info->flush_workers);
2083         btrfs_destroy_workqueue(fs_info->qgroup_rescan_workers);
2084         btrfs_destroy_workqueue(fs_info->extent_workers);
2085 }
2086 
2087 static void free_root_extent_buffers(struct btrfs_root *root)
2088 {
2089         if (root) {
2090                 free_extent_buffer(root->node);
2091                 free_extent_buffer(root->commit_root);
2092                 root->node = NULL;
2093                 root->commit_root = NULL;
2094         }
2095 }
2096 
2097 /* helper to cleanup tree roots */
2098 static void free_root_pointers(struct btrfs_fs_info *info, int chunk_root)
2099 {
2100         free_root_extent_buffers(info->tree_root);
2101 
2102         free_root_extent_buffers(info->dev_root);
2103         free_root_extent_buffers(info->extent_root);
2104         free_root_extent_buffers(info->csum_root);
2105         free_root_extent_buffers(info->quota_root);
2106         free_root_extent_buffers(info->uuid_root);
2107         if (chunk_root)
2108                 free_root_extent_buffers(info->chunk_root);
2109 }
2110 
2111 void btrfs_free_fs_roots(struct btrfs_fs_info *fs_info)
2112 {
2113         int ret;
2114         struct btrfs_root *gang[8];
2115         int i;
2116 
2117         while (!list_empty(&fs_info->dead_roots)) {
2118                 gang[0] = list_entry(fs_info->dead_roots.next,
2119                                      struct btrfs_root, root_list);
2120                 list_del(&gang[0]->root_list);
2121 
2122                 if (test_bit(BTRFS_ROOT_IN_RADIX, &gang[0]->state)) {
2123                         btrfs_drop_and_free_fs_root(fs_info, gang[0]);
2124                 } else {
2125                         free_extent_buffer(gang[0]->node);
2126                         free_extent_buffer(gang[0]->commit_root);
2127                         btrfs_put_fs_root(gang[0]);
2128                 }
2129         }
2130 
2131         while (1) {
2132                 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
2133                                              (void **)gang, 0,
2134                                              ARRAY_SIZE(gang));
2135                 if (!ret)
2136                         break;
2137                 for (i = 0; i < ret; i++)
2138                         btrfs_drop_and_free_fs_root(fs_info, gang[i]);
2139         }
2140 
2141         if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) {
2142                 btrfs_free_log_root_tree(NULL, fs_info);
2143                 btrfs_destroy_pinned_extent(fs_info->tree_root,
2144                                             fs_info->pinned_extents);
2145         }
2146 }
2147 
2148 int open_ctree(struct super_block *sb,
2149                struct btrfs_fs_devices *fs_devices,
2150                char *options)
2151 {
2152         u32 sectorsize;
2153         u32 nodesize;
2154         u32 stripesize;
2155         u64 generation;
2156         u64 features;
2157         struct btrfs_key location;
2158         struct buffer_head *bh;
2159         struct btrfs_super_block *disk_super;
2160         struct btrfs_fs_info *fs_info = btrfs_sb(sb);
2161         struct btrfs_root *tree_root;
2162         struct btrfs_root *extent_root;
2163         struct btrfs_root *csum_root;
2164         struct btrfs_root *chunk_root;
2165         struct btrfs_root *dev_root;
2166         struct btrfs_root *quota_root;
2167         struct btrfs_root *uuid_root;
2168         struct btrfs_root *log_tree_root;
2169         int ret;
2170         int err = -EINVAL;
2171         int num_backups_tried = 0;
2172         int backup_index = 0;
2173         int max_active;
2174         int flags = WQ_MEM_RECLAIM | WQ_FREEZABLE | WQ_UNBOUND;
2175         bool create_uuid_tree;
2176         bool check_uuid_tree;
2177 
2178         tree_root = fs_info->tree_root = btrfs_alloc_root(fs_info);
2179         chunk_root = fs_info->chunk_root = btrfs_alloc_root(fs_info);
2180         if (!tree_root || !chunk_root) {
2181                 err = -ENOMEM;
2182                 goto fail;
2183         }
2184 
2185         ret = init_srcu_struct(&fs_info->subvol_srcu);
2186         if (ret) {
2187                 err = ret;
2188                 goto fail;
2189         }
2190 
2191         ret = setup_bdi(fs_info, &fs_info->bdi);
2192         if (ret) {
2193                 err = ret;
2194                 goto fail_srcu;
2195         }
2196 
2197         ret = percpu_counter_init(&fs_info->dirty_metadata_bytes, 0, GFP_KERNEL);
2198         if (ret) {
2199                 err = ret;
2200                 goto fail_bdi;
2201         }
2202         fs_info->dirty_metadata_batch = PAGE_CACHE_SIZE *
2203                                         (1 + ilog2(nr_cpu_ids));
2204 
2205         ret = percpu_counter_init(&fs_info->delalloc_bytes, 0, GFP_KERNEL);
2206         if (ret) {
2207                 err = ret;
2208                 goto fail_dirty_metadata_bytes;
2209         }
2210 
2211         ret = percpu_counter_init(&fs_info->bio_counter, 0, GFP_KERNEL);
2212         if (ret) {
2213                 err = ret;
2214                 goto fail_delalloc_bytes;
2215         }
2216 
2217         fs_info->btree_inode = new_inode(sb);
2218         if (!fs_info->btree_inode) {
2219                 err = -ENOMEM;
2220                 goto fail_bio_counter;
2221         }
2222 
2223         mapping_set_gfp_mask(fs_info->btree_inode->i_mapping, GFP_NOFS);
2224 
2225         INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_ATOMIC);
2226         INIT_RADIX_TREE(&fs_info->buffer_radix, GFP_ATOMIC);
2227         INIT_LIST_HEAD(&fs_info->trans_list);
2228         INIT_LIST_HEAD(&fs_info->dead_roots);
2229         INIT_LIST_HEAD(&fs_info->delayed_iputs);
2230         INIT_LIST_HEAD(&fs_info->delalloc_roots);
2231         INIT_LIST_HEAD(&fs_info->caching_block_groups);
2232         spin_lock_init(&fs_info->delalloc_root_lock);
2233         spin_lock_init(&fs_info->trans_lock);
2234         spin_lock_init(&fs_info->fs_roots_radix_lock);
2235         spin_lock_init(&fs_info->delayed_iput_lock);
2236         spin_lock_init(&fs_info->defrag_inodes_lock);
2237         spin_lock_init(&fs_info->free_chunk_lock);
2238         spin_lock_init(&fs_info->tree_mod_seq_lock);
2239         spin_lock_init(&fs_info->super_lock);
2240         spin_lock_init(&fs_info->qgroup_op_lock);
2241         spin_lock_init(&fs_info->buffer_lock);
2242         spin_lock_init(&fs_info->unused_bgs_lock);
2243         rwlock_init(&fs_info->tree_mod_log_lock);
2244         mutex_init(&fs_info->reloc_mutex);
2245         mutex_init(&fs_info->delalloc_root_mutex);
2246         seqlock_init(&fs_info->profiles_lock);
2247 
2248         init_completion(&fs_info->kobj_unregister);
2249         INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots);
2250         INIT_LIST_HEAD(&fs_info->space_info);
2251         INIT_LIST_HEAD(&fs_info->tree_mod_seq_list);
2252         INIT_LIST_HEAD(&fs_info->unused_bgs);
2253         btrfs_mapping_init(&fs_info->mapping_tree);
2254         btrfs_init_block_rsv(&fs_info->global_block_rsv,
2255                              BTRFS_BLOCK_RSV_GLOBAL);
2256         btrfs_init_block_rsv(&fs_info->delalloc_block_rsv,
2257                              BTRFS_BLOCK_RSV_DELALLOC);
2258         btrfs_init_block_rsv(&fs_info->trans_block_rsv, BTRFS_BLOCK_RSV_TRANS);
2259         btrfs_init_block_rsv(&fs_info->chunk_block_rsv, BTRFS_BLOCK_RSV_CHUNK);
2260         btrfs_init_block_rsv(&fs_info->empty_block_rsv, BTRFS_BLOCK_RSV_EMPTY);
2261         btrfs_init_block_rsv(&fs_info->delayed_block_rsv,
2262                              BTRFS_BLOCK_RSV_DELOPS);
2263         atomic_set(&fs_info->nr_async_submits, 0);
2264         atomic_set(&fs_info->async_delalloc_pages, 0);
2265         atomic_set(&fs_info->async_submit_draining, 0);
2266         atomic_set(&fs_info->nr_async_bios, 0);
2267         atomic_set(&fs_info->defrag_running, 0);
2268         atomic_set(&fs_info->qgroup_op_seq, 0);
2269         atomic64_set(&fs_info->tree_mod_seq, 0);
2270         fs_info->sb = sb;
2271         fs_info->max_inline = BTRFS_DEFAULT_MAX_INLINE;
2272         fs_info->metadata_ratio = 0;
2273         fs_info->defrag_inodes = RB_ROOT;
2274         fs_info->free_chunk_space = 0;
2275         fs_info->tree_mod_log = RB_ROOT;
2276         fs_info->commit_interval = BTRFS_DEFAULT_COMMIT_INTERVAL;
2277         fs_info->avg_delayed_ref_runtime = div64_u64(NSEC_PER_SEC, 64);
2278         /* readahead state */
2279         INIT_RADIX_TREE(&fs_info->reada_tree, GFP_NOFS & ~__GFP_WAIT);
2280         spin_lock_init(&fs_info->reada_lock);
2281 
2282         fs_info->thread_pool_size = min_t(unsigned long,
2283                                           num_online_cpus() + 2, 8);
2284 
2285         INIT_LIST_HEAD(&fs_info->ordered_roots);
2286         spin_lock_init(&fs_info->ordered_root_lock);
2287         fs_info->delayed_root = kmalloc(sizeof(struct btrfs_delayed_root),
2288                                         GFP_NOFS);
2289         if (!fs_info->delayed_root) {
2290                 err = -ENOMEM;
2291                 goto fail_iput;
2292         }
2293         btrfs_init_delayed_root(fs_info->delayed_root);
2294 
2295         mutex_init(&fs_info->scrub_lock);
2296         atomic_set(&fs_info->scrubs_running, 0);
2297         atomic_set(&fs_info->scrub_pause_req, 0);
2298         atomic_set(&fs_info->scrubs_paused, 0);
2299         atomic_set(&fs_info->scrub_cancel_req, 0);
2300         init_waitqueue_head(&fs_info->replace_wait);
2301         init_waitqueue_head(&fs_info->scrub_pause_wait);
2302         fs_info->scrub_workers_refcnt = 0;
2303 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
2304         fs_info->check_integrity_print_mask = 0;
2305 #endif
2306 
2307         spin_lock_init(&fs_info->balance_lock);
2308         mutex_init(&fs_info->balance_mutex);
2309         atomic_set(&fs_info->balance_running, 0);
2310         atomic_set(&fs_info->balance_pause_req, 0);
2311         atomic_set(&fs_info->balance_cancel_req, 0);
2312         fs_info->balance_ctl = NULL;
2313         init_waitqueue_head(&fs_info->balance_wait_q);
2314         btrfs_init_async_reclaim_work(&fs_info->async_reclaim_work);
2315 
2316         sb->s_blocksize = 4096;
2317         sb->s_blocksize_bits = blksize_bits(4096);
2318         sb->s_bdi = &fs_info->bdi;
2319 
2320         fs_info->btree_inode->i_ino = BTRFS_BTREE_INODE_OBJECTID;
2321         set_nlink(fs_info->btree_inode, 1);
2322         /*
2323          * we set the i_size on the btree inode to the max possible int.
2324          * the real end of the address space is determined by all of
2325          * the devices in the system
2326          */
2327         fs_info->btree_inode->i_size = OFFSET_MAX;
2328         fs_info->btree_inode->i_mapping->a_ops = &btree_aops;
2329         fs_info->btree_inode->i_mapping->backing_dev_info = &fs_info->bdi;
2330 
2331         RB_CLEAR_NODE(&BTRFS_I(fs_info->btree_inode)->rb_node);
2332         extent_io_tree_init(&BTRFS_I(fs_info->btree_inode)->io_tree,
2333                              fs_info->btree_inode->i_mapping);
2334         BTRFS_I(fs_info->btree_inode)->io_tree.track_uptodate = 0;
2335         extent_map_tree_init(&BTRFS_I(fs_info->btree_inode)->extent_tree);
2336 
2337         BTRFS_I(fs_info->btree_inode)->io_tree.ops = &btree_extent_io_ops;
2338 
2339         BTRFS_I(fs_info->btree_inode)->root = tree_root;
2340         memset(&BTRFS_I(fs_info->btree_inode)->location, 0,
2341                sizeof(struct btrfs_key));
2342         set_bit(BTRFS_INODE_DUMMY,
2343                 &BTRFS_I(fs_info->btree_inode)->runtime_flags);
2344         btrfs_insert_inode_hash(fs_info->btree_inode);
2345 
2346         spin_lock_init(&fs_info->block_group_cache_lock);
2347         fs_info->block_group_cache_tree = RB_ROOT;
2348         fs_info->first_logical_byte = (u64)-1;
2349 
2350         extent_io_tree_init(&fs_info->freed_extents[0],
2351                              fs_info->btree_inode->i_mapping);
2352         extent_io_tree_init(&fs_info->freed_extents[1],
2353                              fs_info->btree_inode->i_mapping);
2354         fs_info->pinned_extents = &fs_info->freed_extents[0];
2355         fs_info->do_barriers = 1;
2356 
2357 
2358         mutex_init(&fs_info->ordered_operations_mutex);
2359         mutex_init(&fs_info->ordered_extent_flush_mutex);
2360         mutex_init(&fs_info->tree_log_mutex);
2361         mutex_init(&fs_info->chunk_mutex);
2362         mutex_init(&fs_info->transaction_kthread_mutex);
2363         mutex_init(&fs_info->cleaner_mutex);
2364         mutex_init(&fs_info->volume_mutex);
2365         init_rwsem(&fs_info->commit_root_sem);
2366         init_rwsem(&fs_info->cleanup_work_sem);
2367         init_rwsem(&fs_info->subvol_sem);
2368         sema_init(&fs_info->uuid_tree_rescan_sem, 1);
2369         fs_info->dev_replace.lock_owner = 0;
2370         atomic_set(&fs_info->dev_replace.nesting_level, 0);
2371         mutex_init(&fs_info->dev_replace.lock_finishing_cancel_unmount);
2372         mutex_init(&fs_info->dev_replace.lock_management_lock);
2373         mutex_init(&fs_info->dev_replace.lock);
2374 
2375         spin_lock_init(&fs_info->qgroup_lock);
2376         mutex_init(&fs_info->qgroup_ioctl_lock);
2377         fs_info->qgroup_tree = RB_ROOT;
2378         fs_info->qgroup_op_tree = RB_ROOT;
2379         INIT_LIST_HEAD(&fs_info->dirty_qgroups);
2380         fs_info->qgroup_seq = 1;
2381         fs_info->quota_enabled = 0;
2382         fs_info->pending_quota_state = 0;
2383         fs_info->qgroup_ulist = NULL;
2384         mutex_init(&fs_info->qgroup_rescan_lock);
2385 
2386         btrfs_init_free_cluster(&fs_info->meta_alloc_cluster);
2387         btrfs_init_free_cluster(&fs_info->data_alloc_cluster);
2388 
2389         init_waitqueue_head(&fs_info->transaction_throttle);
2390         init_waitqueue_head(&fs_info->transaction_wait);
2391         init_waitqueue_head(&fs_info->transaction_blocked_wait);
2392         init_waitqueue_head(&fs_info->async_submit_wait);
2393 
2394         ret = btrfs_alloc_stripe_hash_table(fs_info);
2395         if (ret) {
2396                 err = ret;
2397                 goto fail_alloc;
2398         }
2399 
2400         __setup_root(4096, 4096, 4096, tree_root,
2401                      fs_info, BTRFS_ROOT_TREE_OBJECTID);
2402 
2403         invalidate_bdev(fs_devices->latest_bdev);
2404 
2405         /*
2406          * Read super block and check the signature bytes only
2407          */
2408         bh = btrfs_read_dev_super(fs_devices->latest_bdev);
2409         if (!bh) {
2410                 err = -EINVAL;
2411                 goto fail_alloc;
2412         }
2413 
2414         /*
2415          * We want to check superblock checksum, the type is stored inside.
2416          * Pass the whole disk block of size BTRFS_SUPER_INFO_SIZE (4k).
2417          */
2418         if (btrfs_check_super_csum(bh->b_data)) {
2419                 printk(KERN_ERR "BTRFS: superblock checksum mismatch\n");
2420                 err = -EINVAL;
2421                 brelse(bh);
2422                 goto fail_alloc;
2423         }
2424 
2425         /*
2426          * super_copy is zeroed at allocation time and we never touch the
2427          * following bytes up to INFO_SIZE, the checksum is calculated from
2428          * the whole block of INFO_SIZE
2429          */
2430         memcpy(fs_info->super_copy, bh->b_data, sizeof(*fs_info->super_copy));
2431         memcpy(fs_info->super_for_commit, fs_info->super_copy,
2432                sizeof(*fs_info->super_for_commit));
2433         brelse(bh);
2434 
2435         memcpy(fs_info->fsid, fs_info->super_copy->fsid, BTRFS_FSID_SIZE);
2436 
2437         ret = btrfs_check_super_valid(fs_info, sb->s_flags & MS_RDONLY);
2438         if (ret) {
2439                 printk(KERN_ERR "BTRFS: superblock contains fatal errors\n");
2440                 err = -EINVAL;
2441                 goto fail_alloc;
2442         }
2443 
2444         disk_super = fs_info->super_copy;
2445         if (!btrfs_super_root(disk_super))
2446                 goto fail_alloc;
2447 
2448         /* check FS state, whether FS is broken. */
2449         if (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_ERROR)
2450                 set_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state);
2451 
2452         /*
2453          * run through our array of backup supers and setup
2454          * our ring pointer to the oldest one
2455          */
2456         generation = btrfs_super_generation(disk_super);
2457         find_oldest_super_backup(fs_info, generation);
2458 
2459         /*
2460          * In the long term, we'll store the compression type in the super
2461          * block, and it'll be used for per file compression control.
2462          */
2463         fs_info->compress_type = BTRFS_COMPRESS_ZLIB;
2464 
2465         ret = btrfs_parse_options(tree_root, options);
2466         if (ret) {
2467                 err = ret;
2468                 goto fail_alloc;
2469         }
2470 
2471         features = btrfs_super_incompat_flags(disk_super) &
2472                 ~BTRFS_FEATURE_INCOMPAT_SUPP;
2473         if (features) {
2474                 printk(KERN_ERR "BTRFS: couldn't mount because of "
2475                        "unsupported optional features (%Lx).\n",
2476                        features);
2477                 err = -EINVAL;
2478                 goto fail_alloc;
2479         }
2480 
2481         /*
2482          * Leafsize and nodesize were always equal, this is only a sanity check.
2483          */
2484         if (le32_to_cpu(disk_super->__unused_leafsize) !=
2485             btrfs_super_nodesize(disk_super)) {
2486                 printk(KERN_ERR "BTRFS: couldn't mount because metadata "
2487                        "blocksizes don't match.  node %d leaf %d\n",
2488                        btrfs_super_nodesize(disk_super),
2489                        le32_to_cpu(disk_super->__unused_leafsize));
2490                 err = -EINVAL;
2491                 goto fail_alloc;
2492         }
2493         if (btrfs_super_nodesize(disk_super) > BTRFS_MAX_METADATA_BLOCKSIZE) {
2494                 printk(KERN_ERR "BTRFS: couldn't mount because metadata "
2495                        "blocksize (%d) was too large\n",
2496                        btrfs_super_nodesize(disk_super));
2497                 err = -EINVAL;
2498                 goto fail_alloc;
2499         }
2500 
2501         features = btrfs_super_incompat_flags(disk_super);
2502         features |= BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF;
2503         if (tree_root->fs_info->compress_type == BTRFS_COMPRESS_LZO)
2504                 features |= BTRFS_FEATURE_INCOMPAT_COMPRESS_LZO;
2505 
2506         if (features & BTRFS_FEATURE_INCOMPAT_SKINNY_METADATA)
2507                 printk(KERN_INFO "BTRFS: has skinny extents\n");
2508 
2509         /*
2510          * flag our filesystem as having big metadata blocks if
2511          * they are bigger than the page size
2512          */
2513         if (btrfs_super_nodesize(disk_super) > PAGE_CACHE_SIZE) {
2514                 if (!(features & BTRFS_FEATURE_INCOMPAT_BIG_METADATA))
2515                         printk(KERN_INFO "BTRFS: flagging fs with big metadata feature\n");
2516                 features |= BTRFS_FEATURE_INCOMPAT_BIG_METADATA;
2517         }
2518 
2519         nodesize = btrfs_super_nodesize(disk_super);
2520         sectorsize = btrfs_super_sectorsize(disk_super);
2521         stripesize = btrfs_super_stripesize(disk_super);
2522         fs_info->dirty_metadata_batch = nodesize * (1 + ilog2(nr_cpu_ids));
2523         fs_info->delalloc_batch = sectorsize * 512 * (1 + ilog2(nr_cpu_ids));
2524 
2525         /*
2526          * mixed block groups end up with duplicate but slightly offset
2527          * extent buffers for the same range.  It leads to corruptions
2528          */
2529         if ((features & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS) &&
2530             (sectorsize != nodesize)) {
2531                 printk(KERN_WARNING "BTRFS: unequal leaf/node/sector sizes "
2532                                 "are not allowed for mixed block groups on %s\n",
2533                                 sb->s_id);
2534                 goto fail_alloc;
2535         }
2536 
2537         /*
2538          * Needn't use the lock because there is no other task which will
2539          * update the flag.
2540          */
2541         btrfs_set_super_incompat_flags(disk_super, features);
2542 
2543         features = btrfs_super_compat_ro_flags(disk_super) &
2544                 ~BTRFS_FEATURE_COMPAT_RO_SUPP;
2545         if (!(sb->s_flags & MS_RDONLY) && features) {
2546                 printk(KERN_ERR "BTRFS: couldn't mount RDWR because of "
2547                        "unsupported option features (%Lx).\n",
2548                        features);
2549                 err = -EINVAL;
2550                 goto fail_alloc;
2551         }
2552 
2553         max_active = fs_info->thread_pool_size;
2554 
2555         fs_info->workers =
2556                 btrfs_alloc_workqueue("worker", flags | WQ_HIGHPRI,
2557                                       max_active, 16);
2558 
2559         fs_info->delalloc_workers =
2560                 btrfs_alloc_workqueue("delalloc", flags, max_active, 2);
2561 
2562         fs_info->flush_workers =
2563                 btrfs_alloc_workqueue("flush_delalloc", flags, max_active, 0);
2564 
2565         fs_info->caching_workers =
2566                 btrfs_alloc_workqueue("cache", flags, max_active, 0);
2567 
2568         /*
2569          * a higher idle thresh on the submit workers makes it much more
2570          * likely that bios will be send down in a sane order to the
2571          * devices
2572          */
2573         fs_info->submit_workers =
2574                 btrfs_alloc_workqueue("submit", flags,
2575                                       min_t(u64, fs_devices->num_devices,
2576                                             max_active), 64);
2577 
2578         fs_info->fixup_workers =
2579                 btrfs_alloc_workqueue("fixup", flags, 1, 0);
2580 
2581         /*
2582          * endios are largely parallel and should have a very
2583          * low idle thresh
2584          */
2585         fs_info->endio_workers =
2586                 btrfs_alloc_workqueue("endio", flags, max_active, 4);
2587         fs_info->endio_meta_workers =
2588                 btrfs_alloc_workqueue("endio-meta", flags, max_active, 4);
2589         fs_info->endio_meta_write_workers =
2590                 btrfs_alloc_workqueue("endio-meta-write", flags, max_active, 2);
2591         fs_info->endio_raid56_workers =
2592                 btrfs_alloc_workqueue("endio-raid56", flags, max_active, 4);
2593         fs_info->endio_repair_workers =
2594                 btrfs_alloc_workqueue("endio-repair", flags, 1, 0);
2595         fs_info->rmw_workers =
2596                 btrfs_alloc_workqueue("rmw", flags, max_active, 2);
2597         fs_info->endio_write_workers =
2598                 btrfs_alloc_workqueue("endio-write", flags, max_active, 2);
2599         fs_info->endio_freespace_worker =
2600                 btrfs_alloc_workqueue("freespace-write", flags, max_active, 0);
2601         fs_info->delayed_workers =
2602                 btrfs_alloc_workqueue("delayed-meta", flags, max_active, 0);
2603         fs_info->readahead_workers =
2604                 btrfs_alloc_workqueue("readahead", flags, max_active, 2);
2605         fs_info->qgroup_rescan_workers =
2606                 btrfs_alloc_workqueue("qgroup-rescan", flags, 1, 0);
2607         fs_info->extent_workers =
2608                 btrfs_alloc_workqueue("extent-refs", flags,
2609                                       min_t(u64, fs_devices->num_devices,
2610                                             max_active), 8);
2611 
2612         if (!(fs_info->workers && fs_info->delalloc_workers &&
2613               fs_info->submit_workers && fs_info->flush_workers &&
2614               fs_info->endio_workers && fs_info->endio_meta_workers &&
2615               fs_info->endio_meta_write_workers &&
2616               fs_info->endio_repair_workers &&
2617               fs_info->endio_write_workers && fs_info->endio_raid56_workers &&
2618               fs_info->endio_freespace_worker && fs_info->rmw_workers &&
2619               fs_info->caching_workers && fs_info->readahead_workers &&
2620               fs_info->fixup_workers && fs_info->delayed_workers &&
2621               fs_info->extent_workers &&
2622               fs_info->qgroup_rescan_workers)) {
2623                 err = -ENOMEM;
2624                 goto fail_sb_buffer;
2625         }
2626 
2627         fs_info->bdi.ra_pages *= btrfs_super_num_devices(disk_super);
2628         fs_info->bdi.ra_pages = max(fs_info->bdi.ra_pages,
2629                                     4 * 1024 * 1024 / PAGE_CACHE_SIZE);
2630 
2631         tree_root->nodesize = nodesize;
2632         tree_root->sectorsize = sectorsize;
2633         tree_root->stripesize = stripesize;
2634 
2635         sb->s_blocksize = sectorsize;
2636         sb->s_blocksize_bits = blksize_bits(sectorsize);
2637 
2638         if (btrfs_super_magic(disk_super) != BTRFS_MAGIC) {
2639                 printk(KERN_INFO "BTRFS: valid FS not found on %s\n", sb->s_id);
2640                 goto fail_sb_buffer;
2641         }
2642 
2643         if (sectorsize != PAGE_SIZE) {
2644                 printk(KERN_WARNING "BTRFS: Incompatible sector size(%lu) "
2645                        "found on %s\n", (unsigned long)sectorsize, sb->s_id);
2646                 goto fail_sb_buffer;
2647         }
2648 
2649         mutex_lock(&fs_info->chunk_mutex);
2650         ret = btrfs_read_sys_array(tree_root);
2651         mutex_unlock(&fs_info->chunk_mutex);
2652         if (ret) {
2653                 printk(KERN_WARNING "BTRFS: failed to read the system "
2654                        "array on %s\n", sb->s_id);
2655                 goto fail_sb_buffer;
2656         }
2657 
2658         generation = btrfs_super_chunk_root_generation(disk_super);
2659 
2660         __setup_root(nodesize, sectorsize, stripesize, chunk_root,
2661                      fs_info, BTRFS_CHUNK_TREE_OBJECTID);
2662 
2663         chunk_root->node = read_tree_block(chunk_root,
2664                                            btrfs_super_chunk_root(disk_super),
2665                                            generation);
2666         if (!chunk_root->node ||
2667             !test_bit(EXTENT_BUFFER_UPTODATE, &chunk_root->node->bflags)) {
2668                 printk(KERN_WARNING "BTRFS: failed to read chunk root on %s\n",
2669                        sb->s_id);
2670                 goto fail_tree_roots;
2671         }
2672         btrfs_set_root_node(&chunk_root->root_item, chunk_root->node);
2673         chunk_root->commit_root = btrfs_root_node(chunk_root);
2674 
2675         read_extent_buffer(chunk_root->node, fs_info->chunk_tree_uuid,
2676            btrfs_header_chunk_tree_uuid(chunk_root->node), BTRFS_UUID_SIZE);
2677 
2678         ret = btrfs_read_chunk_tree(chunk_root);
2679         if (ret) {
2680                 printk(KERN_WARNING "BTRFS: failed to read chunk tree on %s\n",
2681                        sb->s_id);
2682                 goto fail_tree_roots;
2683         }
2684 
2685         /*
2686          * keep the device that is marked to be the target device for the
2687          * dev_replace procedure
2688          */
2689         btrfs_close_extra_devices(fs_info, fs_devices, 0);
2690 
2691         if (!fs_devices->latest_bdev) {
2692                 printk(KERN_CRIT "BTRFS: failed to read devices on %s\n",
2693                        sb->s_id);
2694                 goto fail_tree_roots;
2695         }
2696 
2697 retry_root_backup:
2698         generation = btrfs_super_generation(disk_super);
2699 
2700         tree_root->node = read_tree_block(tree_root,
2701                                           btrfs_super_root(disk_super),
2702                                           generation);
2703         if (!tree_root->node ||
2704             !test_bit(EXTENT_BUFFER_UPTODATE, &tree_root->node->bflags)) {
2705                 printk(KERN_WARNING "BTRFS: failed to read tree root on %s\n",
2706                        sb->s_id);
2707 
2708                 goto recovery_tree_root;
2709         }
2710 
2711         btrfs_set_root_node(&tree_root->root_item, tree_root->node);
2712         tree_root->commit_root = btrfs_root_node(tree_root);
2713         btrfs_set_root_refs(&tree_root->root_item, 1);
2714 
2715         location.objectid = BTRFS_EXTENT_TREE_OBJECTID;
2716         location.type = BTRFS_ROOT_ITEM_KEY;
2717         location.offset = 0;
2718 
2719         extent_root = btrfs_read_tree_root(tree_root, &location);
2720         if (IS_ERR(extent_root)) {
2721                 ret = PTR_ERR(extent_root);
2722                 goto recovery_tree_root;
2723         }
2724         set_bit(BTRFS_ROOT_TRACK_DIRTY, &extent_root->state);
2725         fs_info->extent_root = extent_root;
2726 
2727         location.objectid = BTRFS_DEV_TREE_OBJECTID;
2728         dev_root = btrfs_read_tree_root(tree_root, &location);
2729         if (IS_ERR(dev_root)) {
2730                 ret = PTR_ERR(dev_root);
2731                 goto recovery_tree_root;
2732         }
2733         set_bit(BTRFS_ROOT_TRACK_DIRTY, &dev_root->state);
2734         fs_info->dev_root = dev_root;
2735         btrfs_init_devices_late(fs_info);
2736 
2737         location.objectid = BTRFS_CSUM_TREE_OBJECTID;
2738         csum_root = btrfs_read_tree_root(tree_root, &location);
2739         if (IS_ERR(csum_root)) {
2740                 ret = PTR_ERR(csum_root);
2741                 goto recovery_tree_root;
2742         }
2743         set_bit(BTRFS_ROOT_TRACK_DIRTY, &csum_root->state);
2744         fs_info->csum_root = csum_root;
2745 
2746         location.objectid = BTRFS_QUOTA_TREE_OBJECTID;
2747         quota_root = btrfs_read_tree_root(tree_root, &location);
2748         if (!IS_ERR(quota_root)) {
2749                 set_bit(BTRFS_ROOT_TRACK_DIRTY, &quota_root->state);
2750                 fs_info->quota_enabled = 1;
2751                 fs_info->pending_quota_state = 1;
2752                 fs_info->quota_root = quota_root;
2753         }
2754 
2755         location.objectid = BTRFS_UUID_TREE_OBJECTID;
2756         uuid_root = btrfs_read_tree_root(tree_root, &location);
2757         if (IS_ERR(uuid_root)) {
2758                 ret = PTR_ERR(uuid_root);
2759                 if (ret != -ENOENT)
2760                         goto recovery_tree_root;
2761                 create_uuid_tree = true;
2762                 check_uuid_tree = false;
2763         } else {
2764                 set_bit(BTRFS_ROOT_TRACK_DIRTY, &uuid_root->state);
2765                 fs_info->uuid_root = uuid_root;
2766                 create_uuid_tree = false;
2767                 check_uuid_tree =
2768                     generation != btrfs_super_uuid_tree_generation(disk_super);
2769         }
2770 
2771         fs_info->generation = generation;
2772         fs_info->last_trans_committed = generation;
2773 
2774         ret = btrfs_recover_balance(fs_info);
2775         if (ret) {
2776                 printk(KERN_WARNING "BTRFS: failed to recover balance\n");
2777                 goto fail_block_groups;
2778         }
2779 
2780         ret = btrfs_init_dev_stats(fs_info);
2781         if (ret) {
2782                 printk(KERN_ERR "BTRFS: failed to init dev_stats: %d\n",
2783                        ret);
2784                 goto fail_block_groups;
2785         }
2786 
2787         ret = btrfs_init_dev_replace(fs_info);
2788         if (ret) {
2789                 pr_err("BTRFS: failed to init dev_replace: %d\n", ret);
2790                 goto fail_block_groups;
2791         }
2792 
2793         btrfs_close_extra_devices(fs_info, fs_devices, 1);
2794 
2795         ret = btrfs_sysfs_add_one(fs_info);
2796         if (ret) {
2797                 pr_err("BTRFS: failed to init sysfs interface: %d\n", ret);
2798                 goto fail_block_groups;
2799         }
2800 
2801         ret = btrfs_init_space_info(fs_info);
2802         if (ret) {
2803                 printk(KERN_ERR "BTRFS: Failed to initial space info: %d\n", ret);
2804                 goto fail_sysfs;
2805         }
2806 
2807         ret = btrfs_read_block_groups(extent_root);
2808         if (ret) {
2809                 printk(KERN_ERR "BTRFS: Failed to read block groups: %d\n", ret);
2810                 goto fail_sysfs;
2811         }
2812         fs_info->num_tolerated_disk_barrier_failures =
2813                 btrfs_calc_num_tolerated_disk_barrier_failures(fs_info);
2814         if (fs_info->fs_devices->missing_devices >
2815              fs_info->num_tolerated_disk_barrier_failures &&
2816             !(sb->s_flags & MS_RDONLY)) {
2817                 printk(KERN_WARNING "BTRFS: "
2818                         "too many missing devices, writeable mount is not allowed\n");
2819                 goto fail_sysfs;
2820         }
2821 
2822         fs_info->cleaner_kthread = kthread_run(cleaner_kthread, tree_root,
2823                                                "btrfs-cleaner");
2824         if (IS_ERR(fs_info->cleaner_kthread))
2825                 goto fail_sysfs;
2826 
2827         fs_info->transaction_kthread = kthread_run(transaction_kthread,
2828                                                    tree_root,
2829                                                    "btrfs-transaction");
2830         if (IS_ERR(fs_info->transaction_kthread))
2831                 goto fail_cleaner;
2832 
2833         if (!btrfs_test_opt(tree_root, SSD) &&
2834             !btrfs_test_opt(tree_root, NOSSD) &&
2835             !fs_info->fs_devices->rotating) {
2836                 printk(KERN_INFO "BTRFS: detected SSD devices, enabling SSD "
2837                        "mode\n");
2838                 btrfs_set_opt(fs_info->mount_opt, SSD);
2839         }
2840 
2841         /* Set the real inode map cache flag */
2842         if (btrfs_test_opt(tree_root, CHANGE_INODE_CACHE))
2843                 btrfs_set_opt(tree_root->fs_info->mount_opt, INODE_MAP_CACHE);
2844 
2845 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
2846         if (btrfs_test_opt(tree_root, CHECK_INTEGRITY)) {
2847                 ret = btrfsic_mount(tree_root, fs_devices,
2848                                     btrfs_test_opt(tree_root,
2849                                         CHECK_INTEGRITY_INCLUDING_EXTENT_DATA) ?
2850                                     1 : 0,
2851                                     fs_info->check_integrity_print_mask);
2852                 if (ret)
2853                         printk(KERN_WARNING "BTRFS: failed to initialize"
2854                                " integrity check module %s\n", sb->s_id);
2855         }
2856 #endif
2857         ret = btrfs_read_qgroup_config(fs_info);
2858         if (ret)
2859                 goto fail_trans_kthread;
2860 
2861         /* do not make disk changes in broken FS */
2862         if (btrfs_super_log_root(disk_super) != 0) {
2863                 u64 bytenr = btrfs_super_log_root(disk_super);
2864 
2865                 if (fs_devices->rw_devices == 0) {
2866                         printk(KERN_WARNING "BTRFS: log replay required "
2867                                "on RO media\n");
2868                         err = -EIO;
2869                         goto fail_qgroup;
2870                 }
2871 
2872                 log_tree_root = btrfs_alloc_root(fs_info);
2873                 if (!log_tree_root) {
2874                         err = -ENOMEM;
2875                         goto fail_qgroup;
2876                 }
2877 
2878                 __setup_root(nodesize, sectorsize, stripesize,
2879                              log_tree_root, fs_info, BTRFS_TREE_LOG_OBJECTID);
2880 
2881                 log_tree_root->node = read_tree_block(tree_root, bytenr,
2882                                                       generation + 1);
2883                 if (!log_tree_root->node ||
2884                     !extent_buffer_uptodate(log_tree_root->node)) {
2885                         printk(KERN_ERR "BTRFS: failed to read log tree\n");
2886                         free_extent_buffer(log_tree_root->node);
2887                         kfree(log_tree_root);
2888                         goto fail_qgroup;
2889                 }
2890                 /* returns with log_tree_root freed on success */
2891                 ret = btrfs_recover_log_trees(log_tree_root);
2892                 if (ret) {
2893                         btrfs_error(tree_root->fs_info, ret,
2894                                     "Failed to recover log tree");
2895                         free_extent_buffer(log_tree_root->node);
2896                         kfree(log_tree_root);
2897                         goto fail_qgroup;
2898                 }
2899 
2900                 if (sb->s_flags & MS_RDONLY) {
2901                         ret = btrfs_commit_super(tree_root);
2902                         if (ret)
2903                                 goto fail_qgroup;
2904                 }
2905         }
2906 
2907         ret = btrfs_find_orphan_roots(tree_root);
2908         if (ret)
2909                 goto fail_qgroup;
2910 
2911         if (!(sb->s_flags & MS_RDONLY)) {
2912                 ret = btrfs_cleanup_fs_roots(fs_info);
2913                 if (ret)
2914                         goto fail_qgroup;
2915 
2916                 mutex_lock(&fs_info->cleaner_mutex);
2917                 ret = btrfs_recover_relocation(tree_root);
2918                 mutex_unlock(&fs_info->cleaner_mutex);
2919                 if (ret < 0) {
2920                         printk(KERN_WARNING
2921                                "BTRFS: failed to recover relocation\n");
2922                         err = -EINVAL;
2923                         goto fail_qgroup;
2924                 }
2925         }
2926 
2927         location.objectid = BTRFS_FS_TREE_OBJECTID;
2928         location.type = BTRFS_ROOT_ITEM_KEY;
2929         location.offset = 0;
2930 
2931         fs_info->fs_root = btrfs_read_fs_root_no_name(fs_info, &location);
2932         if (IS_ERR(fs_info->fs_root)) {
2933                 err = PTR_ERR(fs_info->fs_root);
2934                 goto fail_qgroup;
2935         }
2936 
2937         if (sb->s_flags & MS_RDONLY)
2938                 return 0;
2939 
2940         down_read(&fs_info->cleanup_work_sem);
2941         if ((ret = btrfs_orphan_cleanup(fs_info->fs_root)) ||
2942             (ret = btrfs_orphan_cleanup(fs_info->tree_root))) {
2943                 up_read(&fs_info->cleanup_work_sem);
2944                 close_ctree(tree_root);
2945                 return ret;
2946         }
2947         up_read(&fs_info->cleanup_work_sem);
2948 
2949         ret = btrfs_resume_balance_async(fs_info);
2950         if (ret) {
2951                 printk(KERN_WARNING "BTRFS: failed to resume balance\n");
2952                 close_ctree(tree_root);
2953                 return ret;
2954         }
2955 
2956         ret = btrfs_resume_dev_replace_async(fs_info);
2957         if (ret) {
2958                 pr_warn("BTRFS: failed to resume dev_replace\n");
2959                 close_ctree(tree_root);
2960                 return ret;
2961         }
2962 
2963         btrfs_qgroup_rescan_resume(fs_info);
2964 
2965         if (create_uuid_tree) {
2966                 pr_info("BTRFS: creating UUID tree\n");
2967                 ret = btrfs_create_uuid_tree(fs_info);
2968                 if (ret) {
2969                         pr_warn("BTRFS: failed to create the UUID tree %d\n",
2970                                 ret);
2971                         close_ctree(tree_root);
2972                         return ret;
2973                 }
2974         } else if (check_uuid_tree ||
2975                    btrfs_test_opt(tree_root, RESCAN_UUID_TREE)) {
2976                 pr_info("BTRFS: checking UUID tree\n");
2977                 ret = btrfs_check_uuid_tree(fs_info);
2978                 if (ret) {
2979                         pr_warn("BTRFS: failed to check the UUID tree %d\n",
2980                                 ret);
2981                         close_ctree(tree_root);
2982                         return ret;
2983                 }
2984         } else {
2985                 fs_info->update_uuid_tree_gen = 1;
2986         }
2987 
2988         fs_info->open = 1;
2989 
2990         return 0;
2991 
2992 fail_qgroup:
2993         btrfs_free_qgroup_config(fs_info);
2994 fail_trans_kthread:
2995         kthread_stop(fs_info->transaction_kthread);
2996         btrfs_cleanup_transaction(fs_info->tree_root);
2997         btrfs_free_fs_roots(fs_info);
2998 fail_cleaner:
2999         kthread_stop(fs_info->cleaner_kthread);
3000 
3001         /*
3002          * make sure we're done with the btree inode before we stop our
3003          * kthreads
3004          */
3005         filemap_write_and_wait(fs_info->btree_inode->i_mapping);
3006 
3007 fail_sysfs:
3008         btrfs_sysfs_remove_one(fs_info);
3009 
3010 fail_block_groups:
3011         btrfs_put_block_group_cache(fs_info);
3012         btrfs_free_block_groups(fs_info);
3013 
3014 fail_tree_roots:
3015         free_root_pointers(fs_info, 1);
3016         invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
3017 
3018 fail_sb_buffer:
3019         btrfs_stop_all_workers(fs_info);
3020 fail_alloc:
3021 fail_iput:
3022         btrfs_mapping_tree_free(&fs_info->mapping_tree);
3023 
3024         iput(fs_info->btree_inode);
3025 fail_bio_counter:
3026         percpu_counter_destroy(&fs_info->bio_counter);
3027 fail_delalloc_bytes:
3028         percpu_counter_destroy(&fs_info->delalloc_bytes);
3029 fail_dirty_metadata_bytes:
3030         percpu_counter_destroy(&fs_info->dirty_metadata_bytes);
3031 fail_bdi:
3032         bdi_destroy(&fs_info->bdi);
3033 fail_srcu:
3034         cleanup_srcu_struct(&fs_info->subvol_srcu);
3035 fail:
3036         btrfs_free_stripe_hash_table(fs_info);
3037         btrfs_close_devices(fs_info->fs_devices);
3038         return err;
3039 
3040 recovery_tree_root:
3041         if (!btrfs_test_opt(tree_root, RECOVERY))
3042                 goto fail_tree_roots;
3043 
3044         free_root_pointers(fs_info, 0);
3045 
3046         /* don't use the log in recovery mode, it won't be valid */
3047         btrfs_set_super_log_root(disk_super, 0);
3048 
3049         /* we can't trust the free space cache either */
3050         btrfs_set_opt(fs_info->mount_opt, CLEAR_CACHE);
3051 
3052         ret = next_root_backup(fs_info, fs_info->super_copy,
3053                                &num_backups_tried, &backup_index);
3054         if (ret == -1)
3055                 goto fail_block_groups;
3056         goto retry_root_backup;
3057 }
3058 
3059 static void btrfs_end_buffer_write_sync(struct buffer_head *bh, int uptodate)
3060 {
3061         if (uptodate) {
3062                 set_buffer_uptodate(bh);
3063         } else {
3064                 struct btrfs_device *device = (struct btrfs_device *)
3065                         bh->b_private;
3066 
3067                 printk_ratelimited_in_rcu(KERN_WARNING "BTRFS: lost page write due to "
3068                                           "I/O error on %s\n",
3069                                           rcu_str_deref(device->name));
3070                 /* note, we dont' set_buffer_write_io_error because we have
3071                  * our own ways of dealing with the IO errors
3072                  */
3073                 clear_buffer_uptodate(bh);
3074                 btrfs_dev_stat_inc_and_print(device, BTRFS_DEV_STAT_WRITE_ERRS);
3075         }
3076         unlock_buffer(bh);
3077         put_bh(bh);
3078 }
3079 
3080 struct buffer_head *btrfs_read_dev_super(struct block_device *bdev)
3081 {
3082         struct buffer_head *bh;
3083         struct buffer_head *latest = NULL;
3084         struct btrfs_super_block *super;
3085         int i;
3086         u64 transid = 0;
3087         u64 bytenr;
3088 
3089         /* we would like to check all the supers, but that would make
3090          * a btrfs mount succeed after a mkfs from a different FS.
3091          * So, we need to add a special mount option to scan for
3092          * later supers, using BTRFS_SUPER_MIRROR_MAX instead
3093          */
3094         for (i = 0; i < 1; i++) {
3095                 bytenr = btrfs_sb_offset(i);
3096                 if (bytenr + BTRFS_SUPER_INFO_SIZE >=
3097                                         i_size_read(bdev->bd_inode))
3098                         break;
3099                 bh = __bread(bdev, bytenr / 4096,
3100                                         BTRFS_SUPER_INFO_SIZE);
3101                 if (!bh)
3102                         continue;
3103 
3104                 super = (struct btrfs_super_block *)bh->b_data;
3105                 if (btrfs_super_bytenr(super) != bytenr ||
3106                     btrfs_super_magic(super) != BTRFS_MAGIC) {
3107                         brelse(bh);
3108                         continue;
3109                 }
3110 
3111                 if (!latest || btrfs_super_generation(super) > transid) {
3112                         brelse(latest);
3113                         latest = bh;
3114                         transid = btrfs_super_generation(super);
3115                 } else {
3116                         brelse(bh);
3117                 }
3118         }
3119         return latest;
3120 }
3121 
3122 /*
3123  * this should be called twice, once with wait == 0 and
3124  * once with wait == 1.  When wait == 0 is done, all the buffer heads
3125  * we write are pinned.
3126  *
3127  * They are released when wait == 1 is done.
3128  * max_mirrors must be the same for both runs, and it indicates how
3129  * many supers on this one device should be written.
3130  *
3131  * max_mirrors == 0 means to write them all.
3132  */
3133 static int write_dev_supers(struct btrfs_device *device,
3134                             struct btrfs_super_block *sb,
3135                             int do_barriers, int wait, int max_mirrors)
3136 {
3137         struct buffer_head *bh;
3138         int i;
3139         int ret;
3140         int errors = 0;
3141         u32 crc;
3142         u64 bytenr;
3143 
3144         if (max_mirrors == 0)
3145                 max_mirrors = BTRFS_SUPER_MIRROR_MAX;
3146 
3147         for (i = 0; i < max_mirrors; i++) {
3148                 bytenr = btrfs_sb_offset(i);
3149                 if (bytenr + BTRFS_SUPER_INFO_SIZE >=
3150                     device->commit_total_bytes)
3151                         break;
3152 
3153                 if (wait) {
3154                         bh = __find_get_block(device->bdev, bytenr / 4096,
3155                                               BTRFS_SUPER_INFO_SIZE);
3156                         if (!bh) {
3157                                 errors++;
3158                                 continue;
3159                         }
3160                         wait_on_buffer(bh);
3161                         if (!buffer_uptodate(bh))
3162                                 errors++;
3163 
3164                         /* drop our reference */
3165                         brelse(bh);
3166 
3167                         /* drop the reference from the wait == 0 run */
3168                         brelse(bh);
3169                         continue;
3170                 } else {
3171                         btrfs_set_super_bytenr(sb, bytenr);
3172 
3173                         crc = ~(u32)0;
3174                         crc = btrfs_csum_data((char *)sb +
3175                                               BTRFS_CSUM_SIZE, crc,
3176                                               BTRFS_SUPER_INFO_SIZE -
3177                                               BTRFS_CSUM_SIZE);
3178                         btrfs_csum_final(crc, sb->csum);
3179 
3180                         /*
3181                          * one reference for us, and we leave it for the
3182                          * caller
3183                          */
3184                         bh = __getblk(device->bdev, bytenr / 4096,
3185                                       BTRFS_SUPER_INFO_SIZE);
3186                         if (!bh) {
3187                                 printk(KERN_ERR "BTRFS: couldn't get super "
3188                                        "buffer head for bytenr %Lu\n", bytenr);
3189                                 errors++;
3190                                 continue;
3191                         }
3192 
3193                         memcpy(bh->b_data, sb, BTRFS_SUPER_INFO_SIZE);
3194 
3195                         /* one reference for submit_bh */
3196                         get_bh(bh);
3197 
3198                         set_buffer_uptodate(bh);
3199                         lock_buffer(bh);
3200                         bh->b_end_io = btrfs_end_buffer_write_sync;
3201                         bh->b_private = device;
3202                 }
3203 
3204                 /*
3205                  * we fua the first super.  The others we allow
3206                  * to go down lazy.
3207                  */
3208                 if (i == 0)
3209                         ret = btrfsic_submit_bh(WRITE_FUA, bh);
3210                 else
3211                         ret = btrfsic_submit_bh(WRITE_SYNC, bh);
3212                 if (ret)
3213                         errors++;
3214         }
3215         return errors < i ? 0 : -1;
3216 }
3217 
3218 /*
3219  * endio for the write_dev_flush, this will wake anyone waiting
3220  * for the barrier when it is done
3221  */
3222 static void btrfs_end_empty_barrier(struct bio *bio, int err)
3223 {
3224         if (err) {
3225                 if (err == -EOPNOTSUPP)
3226                         set_bit(BIO_EOPNOTSUPP, &bio->bi_flags);
3227                 clear_bit(BIO_UPTODATE, &bio->bi_flags);
3228         }
3229         if (bio->bi_private)
3230                 complete(bio->bi_private);
3231         bio_put(bio);
3232 }
3233 
3234 /*
3235  * trigger flushes for one the devices.  If you pass wait == 0, the flushes are
3236  * sent down.  With wait == 1, it waits for the previous flush.
3237  *
3238  * any device where the flush fails with eopnotsupp are flagged as not-barrier
3239  * capable
3240  */
3241 static int write_dev_flush(struct btrfs_device *device, int wait)
3242 {
3243         struct bio *bio;
3244         int ret = 0;
3245 
3246         if (device->nobarriers)
3247                 return 0;
3248 
3249         if (wait) {
3250                 bio = device->flush_bio;
3251                 if (!bio)
3252                         return 0;
3253 
3254                 wait_for_completion(&device->flush_wait);
3255 
3256                 if (bio_flagged(bio, BIO_EOPNOTSUPP)) {
3257                         printk_in_rcu("BTRFS: disabling barriers on dev %s\n",
3258                                       rcu_str_deref(device->name));
3259                         device->nobarriers = 1;
3260                 } else if (!bio_flagged(bio, BIO_UPTODATE)) {
3261                         ret = -EIO;
3262                         btrfs_dev_stat_inc_and_print(device,
3263                                 BTRFS_DEV_STAT_FLUSH_ERRS);
3264                 }
3265 
3266                 /* drop the reference from the wait == 0 run */
3267                 bio_put(bio);
3268                 device->flush_bio = NULL;
3269 
3270                 return ret;
3271         }
3272 
3273         /*
3274          * one reference for us, and we leave it for the
3275          * caller
3276          */
3277         device->flush_bio = NULL;
3278         bio = btrfs_io_bio_alloc(GFP_NOFS, 0);
3279         if (!bio)
3280                 return -ENOMEM;
3281 
3282         bio->bi_end_io = btrfs_end_empty_barrier;
3283         bio->bi_bdev = device->bdev;
3284         init_completion(&device->flush_wait);
3285         bio->bi_private = &device->flush_wait;
3286         device->flush_bio = bio;
3287 
3288         bio_get(bio);
3289         btrfsic_submit_bio(WRITE_FLUSH, bio);
3290 
3291         return 0;
3292 }
3293 
3294 /*
3295  * send an empty flush down to each device in parallel,
3296  * then wait for them
3297  */
3298 static int barrier_all_devices(struct btrfs_fs_info *info)
3299 {
3300         struct list_head *head;
3301         struct btrfs_device *dev;
3302         int errors_send = 0;
3303         int errors_wait = 0;
3304         int ret;
3305 
3306         /* send down all the barriers */
3307         head = &info->fs_devices->devices;
3308         list_for_each_entry_rcu(dev, head, dev_list) {
3309                 if (dev->missing)
3310                         continue;
3311                 if (!dev->bdev) {
3312                         errors_send++;
3313                         continue;
3314                 }
3315                 if (!dev->in_fs_metadata || !dev->writeable)
3316                         continue;
3317 
3318                 ret = write_dev_flush(dev, 0);
3319                 if (ret)
3320                         errors_send++;
3321         }
3322 
3323         /* wait for all the barriers */
3324         list_for_each_entry_rcu(dev, head, dev_list) {
3325                 if (dev->missing)
3326                         continue;
3327                 if (!dev->bdev) {
3328                         errors_wait++;
3329                         continue;
3330                 }
3331                 if (!dev->in_fs_metadata || !dev->writeable)
3332                         continue;
3333 
3334                 ret = write_dev_flush(dev, 1);
3335                 if (ret)
3336                         errors_wait++;
3337         }
3338         if (errors_send > info->num_tolerated_disk_barrier_failures ||
3339             errors_wait > info->num_tolerated_disk_barrier_failures)
3340                 return -EIO;
3341         return 0;
3342 }
3343 
3344 int btrfs_calc_num_tolerated_disk_barrier_failures(
3345         struct btrfs_fs_info *fs_info)
3346 {
3347         struct btrfs_ioctl_space_info space;
3348         struct btrfs_space_info *sinfo;
3349         u64 types[] = {BTRFS_BLOCK_GROUP_DATA,
3350                        BTRFS_BLOCK_GROUP_SYSTEM,
3351                        BTRFS_BLOCK_GROUP_METADATA,
3352                        BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA};
3353         int num_types = 4;
3354         int i;
3355         int c;
3356         int num_tolerated_disk_barrier_failures =
3357                 (int)fs_info->fs_devices->num_devices;
3358 
3359         for (i = 0; i < num_types; i++) {
3360                 struct btrfs_space_info *tmp;
3361 
3362                 sinfo = NULL;
3363                 rcu_read_lock();
3364                 list_for_each_entry_rcu(tmp, &fs_info->space_info, list) {
3365                         if (tmp->flags == types[i]) {
3366                                 sinfo = tmp;
3367                                 break;
3368                         }
3369                 }
3370                 rcu_read_unlock();
3371 
3372                 if (!sinfo)
3373                         continue;
3374 
3375                 down_read(&sinfo->groups_sem);
3376                 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
3377                         if (!list_empty(&sinfo->block_groups[c])) {
3378                                 u64 flags;
3379 
3380                                 btrfs_get_block_group_info(
3381                                         &sinfo->block_groups[c], &space);
3382                                 if (space.total_bytes == 0 ||
3383                                     space.used_bytes == 0)
3384                                         continue;
3385                                 flags = space.flags;
3386                                 /*
3387                                  * return
3388                                  * 0: if dup, single or RAID0 is configured for
3389                                  *    any of metadata, system or data, else
3390                                  * 1: if RAID5 is configured, or if RAID1 or
3391                                  *    RAID10 is configured and only two mirrors
3392                                  *    are used, else
3393                                  * 2: if RAID6 is configured, else
3394                                  * num_mirrors - 1: if RAID1 or RAID10 is
3395                                  *                  configured and more than
3396                                  *                  2 mirrors are used.
3397                                  */
3398                                 if (num_tolerated_disk_barrier_failures > 0 &&
3399                                     ((flags & (BTRFS_BLOCK_GROUP_DUP |
3400                                                BTRFS_BLOCK_GROUP_RAID0)) ||
3401                                      ((flags & BTRFS_BLOCK_GROUP_PROFILE_MASK)
3402                                       == 0)))
3403                                         num_tolerated_disk_barrier_failures = 0;
3404                                 else if (num_tolerated_disk_barrier_failures > 1) {
3405                                         if (flags & (BTRFS_BLOCK_GROUP_RAID1 |
3406                                             BTRFS_BLOCK_GROUP_RAID5 |
3407                                             BTRFS_BLOCK_GROUP_RAID10)) {
3408                                                 num_tolerated_disk_barrier_failures = 1;
3409                                         } else if (flags &
3410                                                    BTRFS_BLOCK_GROUP_RAID6) {
3411                                                 num_tolerated_disk_barrier_failures = 2;
3412                                         }
3413                                 }
3414                         }
3415                 }
3416                 up_read(&sinfo->groups_sem);
3417         }
3418 
3419         return num_tolerated_disk_barrier_failures;
3420 }
3421 
3422 static int write_all_supers(struct btrfs_root *root, int max_mirrors)
3423 {
3424         struct list_head *head;
3425         struct btrfs_device *dev;
3426         struct btrfs_super_block *sb;
3427         struct btrfs_dev_item *dev_item;
3428         int ret;
3429         int do_barriers;
3430         int max_errors;
3431         int total_errors = 0;
3432         u64 flags;
3433 
3434         do_barriers = !btrfs_test_opt(root, NOBARRIER);
3435         backup_super_roots(root->fs_info);
3436 
3437         sb = root->fs_info->super_for_commit;
3438         dev_item = &sb->dev_item;
3439 
3440         mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
3441         head = &root->fs_info->fs_devices->devices;
3442         max_errors = btrfs_super_num_devices(root->fs_info->super_copy) - 1;
3443 
3444         if (do_barriers) {
3445                 ret = barrier_all_devices(root->fs_info);
3446                 if (ret) {
3447                         mutex_unlock(
3448                                 &root->fs_info->fs_devices->device_list_mutex);
3449                         btrfs_error(root->fs_info, ret,
3450                                     "errors while submitting device barriers.");
3451                         return ret;
3452                 }
3453         }
3454 
3455         list_for_each_entry_rcu(dev, head, dev_list) {
3456                 if (!dev->bdev) {
3457                         total_errors++;
3458                         continue;
3459                 }
3460                 if (!dev->in_fs_metadata || !dev->writeable)
3461                         continue;
3462 
3463                 btrfs_set_stack_device_generation(dev_item, 0);
3464                 btrfs_set_stack_device_type(dev_item, dev->type);
3465                 btrfs_set_stack_device_id(dev_item, dev->devid);
3466                 btrfs_set_stack_device_total_bytes(dev_item,
3467                                                    dev->commit_total_bytes);
3468                 btrfs_set_stack_device_bytes_used(dev_item,
3469                                                   dev->commit_bytes_used);
3470                 btrfs_set_stack_device_io_align(dev_item, dev->io_align);
3471                 btrfs_set_stack_device_io_width(dev_item, dev->io_width);
3472                 btrfs_set_stack_device_sector_size(dev_item, dev->sector_size);
3473                 memcpy(dev_item->uuid, dev->uuid, BTRFS_UUID_SIZE);
3474                 memcpy(dev_item->fsid, dev->fs_devices->fsid, BTRFS_UUID_SIZE);
3475 
3476                 flags = btrfs_super_flags(sb);
3477                 btrfs_set_super_flags(sb, flags | BTRFS_HEADER_FLAG_WRITTEN);
3478 
3479                 ret = write_dev_supers(dev, sb, do_barriers, 0, max_mirrors);
3480                 if (ret)
3481                         total_errors++;
3482         }
3483         if (total_errors > max_errors) {
3484                 btrfs_err(root->fs_info, "%d errors while writing supers",
3485                        total_errors);
3486                 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
3487 
3488                 /* FUA is masked off if unsupported and can't be the reason */
3489                 btrfs_error(root->fs_info, -EIO,
3490                             "%d errors while writing supers", total_errors);
3491                 return -EIO;
3492         }
3493 
3494         total_errors = 0;
3495         list_for_each_entry_rcu(dev, head, dev_list) {
3496                 if (!dev->bdev)
3497                         continue;
3498                 if (!dev->in_fs_metadata || !dev->writeable)
3499                         continue;
3500 
3501                 ret = write_dev_supers(dev, sb, do_barriers, 1, max_mirrors);
3502                 if (ret)
3503                         total_errors++;
3504         }
3505         mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
3506         if (total_errors > max_errors) {
3507                 btrfs_error(root->fs_info, -EIO,
3508                             "%d errors while writing supers", total_errors);
3509                 return -EIO;
3510         }
3511         return 0;
3512 }
3513 
3514 int write_ctree_super(struct btrfs_trans_handle *trans,
3515                       struct btrfs_root *root, int max_mirrors)
3516 {
3517         return write_all_supers(root, max_mirrors);
3518 }
3519 
3520 /* Drop a fs root from the radix tree and free it. */
3521 void btrfs_drop_and_free_fs_root(struct btrfs_fs_info *fs_info,
3522                                   struct btrfs_root *root)
3523 {
3524         spin_lock(&fs_info->fs_roots_radix_lock);
3525         radix_tree_delete(&fs_info->fs_roots_radix,
3526                           (unsigned long)root->root_key.objectid);
3527         spin_unlock(&fs_info->fs_roots_radix_lock);
3528 
3529         if (btrfs_root_refs(&root->root_item) == 0)
3530                 synchronize_srcu(&fs_info->subvol_srcu);
3531 
3532         if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state))
3533                 btrfs_free_log(NULL, root);
3534 
3535         if (root->free_ino_pinned)
3536                 __btrfs_remove_free_space_cache(root->free_ino_pinned);
3537         if (root->free_ino_ctl)
3538                 __btrfs_remove_free_space_cache(root->free_ino_ctl);
3539         free_fs_root(root);
3540 }
3541 
3542 static void free_fs_root(struct btrfs_root *root)
3543 {
3544         iput(root->ino_cache_inode);
3545         WARN_ON(!RB_EMPTY_ROOT(&root->inode_tree));
3546         btrfs_free_block_rsv(root, root->orphan_block_rsv);
3547         root->orphan_block_rsv = NULL;
3548         if (root->anon_dev)
3549                 free_anon_bdev(root->anon_dev);
3550         if (root->subv_writers)
3551                 btrfs_free_subvolume_writers(root->subv_writers);
3552         free_extent_buffer(root->node);
3553         free_extent_buffer(root->commit_root);
3554         kfree(root->free_ino_ctl);
3555         kfree(root->free_ino_pinned);
3556         kfree(root->name);
3557         btrfs_put_fs_root(root);
3558 }
3559 
3560 void btrfs_free_fs_root(struct btrfs_root *root)
3561 {
3562         free_fs_root(root);
3563 }
3564 
3565 int btrfs_cleanup_fs_roots(struct btrfs_fs_info *fs_info)
3566 {
3567         u64 root_objectid = 0;
3568         struct btrfs_root *gang[8];
3569         int i = 0;
3570         int err = 0;
3571         unsigned int ret = 0;
3572         int index;
3573 
3574         while (1) {
3575                 index = srcu_read_lock(&fs_info->subvol_srcu);
3576                 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
3577                                              (void **)gang, root_objectid,
3578                                              ARRAY_SIZE(gang));
3579                 if (!ret) {
3580                         srcu_read_unlock(&fs_info->subvol_srcu, index);
3581                         break;
3582                 }
3583                 root_objectid = gang[ret - 1]->root_key.objectid + 1;
3584 
3585                 for (i = 0; i < ret; i++) {
3586                         /* Avoid to grab roots in dead_roots */
3587                         if (btrfs_root_refs(&gang[i]->root_item) == 0) {
3588                                 gang[i] = NULL;
3589                                 continue;
3590                         }
3591                         /* grab all the search result for later use */
3592                         gang[i] = btrfs_grab_fs_root(gang[i]);
3593                 }
3594                 srcu_read_unlock(&fs_info->subvol_srcu, index);
3595 
3596                 for (i = 0; i < ret; i++) {
3597                         if (!gang[i])
3598                                 continue;
3599                         root_objectid = gang[i]->root_key.objectid;
3600                         err = btrfs_orphan_cleanup(gang[i]);
3601                         if (err)
3602                                 break;
3603                         btrfs_put_fs_root(gang[i]);
3604                 }
3605                 root_objectid++;
3606         }
3607 
3608         /* release the uncleaned roots due to error */
3609         for (; i < ret; i++) {
3610                 if (gang[i])
3611                         btrfs_put_fs_root(gang[i]);
3612         }
3613         return err;
3614 }
3615 
3616 int btrfs_commit_super(struct btrfs_root *root)
3617 {
3618         struct btrfs_trans_handle *trans;
3619 
3620         mutex_lock(&root->fs_info->cleaner_mutex);
3621         btrfs_run_delayed_iputs(root);
3622         mutex_unlock(&root->fs_info->cleaner_mutex);
3623         wake_up_process(root->fs_info->cleaner_kthread);
3624 
3625         /* wait until ongoing cleanup work done */
3626         down_write(&root->fs_info->cleanup_work_sem);
3627         up_write(&root->fs_info->cleanup_work_sem);
3628 
3629         trans = btrfs_join_transaction(root);
3630         if (IS_ERR(trans))
3631                 return PTR_ERR(trans);
3632         return btrfs_commit_transaction(trans, root);
3633 }
3634 
3635 void close_ctree(struct btrfs_root *root)
3636 {
3637         struct btrfs_fs_info *fs_info = root->fs_info;
3638         int ret;
3639 
3640         fs_info->closing = 1;
3641         smp_mb();
3642 
3643         /* wait for the uuid_scan task to finish */
3644         down(&fs_info->uuid_tree_rescan_sem);
3645         /* avoid complains from lockdep et al., set sem back to initial state */
3646         up(&fs_info->uuid_tree_rescan_sem);
3647 
3648         /* pause restriper - we want to resume on mount */
3649         btrfs_pause_balance(fs_info);
3650 
3651         btrfs_dev_replace_suspend_for_unmount(fs_info);
3652 
3653         btrfs_scrub_cancel(fs_info);
3654 
3655         /* wait for any defraggers to finish */
3656         wait_event(fs_info->transaction_wait,
3657                    (atomic_read(&fs_info->defrag_running) == 0));
3658 
3659         /* clear out the rbtree of defraggable inodes */
3660         btrfs_cleanup_defrag_inodes(fs_info);
3661 
3662         cancel_work_sync(&fs_info->async_reclaim_work);
3663 
3664         if (!(fs_info->sb->s_flags & MS_RDONLY)) {
3665                 ret = btrfs_commit_super(root);
3666                 if (ret)
3667                         btrfs_err(root->fs_info, "commit super ret %d", ret);
3668         }
3669 
3670         if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state))
3671                 btrfs_error_commit_super(root);
3672 
3673         kthread_stop(fs_info->transaction_kthread);
3674         kthread_stop(fs_info->cleaner_kthread);
3675 
3676         fs_info->closing = 2;
3677         smp_mb();
3678 
3679         btrfs_free_qgroup_config(root->fs_info);
3680 
3681         if (percpu_counter_sum(&fs_info->delalloc_bytes)) {
3682                 btrfs_info(root->fs_info, "at unmount delalloc count %lld",
3683                        percpu_counter_sum(&fs_info->delalloc_bytes));
3684         }
3685 
3686         btrfs_sysfs_remove_one(fs_info);
3687 
3688         btrfs_free_fs_roots(fs_info);
3689 
3690         btrfs_put_block_group_cache(fs_info);
3691 
3692         btrfs_free_block_groups(fs_info);
3693 
3694         /*
3695          * we must make sure there is not any read request to
3696          * submit after we stopping all workers.
3697          */
3698         invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
3699         btrfs_stop_all_workers(fs_info);
3700 
3701         fs_info->open = 0;
3702         free_root_pointers(fs_info, 1);
3703 
3704         iput(fs_info->btree_inode);
3705 
3706 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
3707         if (btrfs_test_opt(root, CHECK_INTEGRITY))
3708                 btrfsic_unmount(root, fs_info->fs_devices);
3709 #endif
3710 
3711         btrfs_close_devices(fs_info->fs_devices);
3712         btrfs_mapping_tree_free(&fs_info->mapping_tree);
3713 
3714         percpu_counter_destroy(&fs_info->dirty_metadata_bytes);
3715         percpu_counter_destroy(&fs_info->delalloc_bytes);
3716         percpu_counter_destroy(&fs_info->bio_counter);
3717         bdi_destroy(&fs_info->bdi);
3718         cleanup_srcu_struct(&fs_info->subvol_srcu);
3719 
3720         btrfs_free_stripe_hash_table(fs_info);
3721 
3722         btrfs_free_block_rsv(root, root->orphan_block_rsv);
3723         root->orphan_block_rsv = NULL;
3724 }
3725 
3726 int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid,
3727                           int atomic)
3728 {
3729         int ret;
3730         struct inode *btree_inode = buf->pages[0]->mapping->host;
3731 
3732         ret = extent_buffer_uptodate(buf);
3733         if (!ret)
3734                 return ret;
3735 
3736         ret = verify_parent_transid(&BTRFS_I(btree_inode)->io_tree, buf,
3737                                     parent_transid, atomic);
3738         if (ret == -EAGAIN)
3739                 return ret;
3740         return !ret;
3741 }
3742 
3743 int btrfs_set_buffer_uptodate(struct extent_buffer *buf)
3744 {
3745         return set_extent_buffer_uptodate(buf);
3746 }
3747 
3748 void btrfs_mark_buffer_dirty(struct extent_buffer *buf)
3749 {
3750         struct btrfs_root *root;
3751         u64 transid = btrfs_header_generation(buf);
3752         int was_dirty;
3753 
3754 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
3755         /*
3756          * This is a fast path so only do this check if we have sanity tests
3757          * enabled.  Normal people shouldn't be marking dummy buffers as dirty
3758          * outside of the sanity tests.
3759          */
3760         if (unlikely(test_bit(EXTENT_BUFFER_DUMMY, &buf->bflags)))
3761                 return;
3762 #endif
3763         root = BTRFS_I(buf->pages[0]->mapping->host)->root;
3764         btrfs_assert_tree_locked(buf);
3765         if (transid != root->fs_info->generation)
3766                 WARN(1, KERN_CRIT "btrfs transid mismatch buffer %llu, "
3767                        "found %llu running %llu\n",
3768                         buf->start, transid, root->fs_info->generation);
3769         was_dirty = set_extent_buffer_dirty(buf);
3770         if (!was_dirty)
3771                 __percpu_counter_add(&root->fs_info->dirty_metadata_bytes,
3772                                      buf->len,
3773                                      root->fs_info->dirty_metadata_batch);
3774 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
3775         if (btrfs_header_level(buf) == 0 && check_leaf(root, buf)) {
3776                 btrfs_print_leaf(root, buf);
3777                 ASSERT(0);
3778         }
3779 #endif
3780 }
3781 
3782 static void __btrfs_btree_balance_dirty(struct btrfs_root *root,
3783                                         int flush_delayed)
3784 {
3785         /*
3786          * looks as though older kernels can get into trouble with
3787          * this code, they end up stuck in balance_dirty_pages forever
3788          */
3789         int ret;
3790 
3791         if (current->flags & PF_MEMALLOC)
3792                 return;
3793 
3794         if (flush_delayed)
3795                 btrfs_balance_delayed_items(root);
3796 
3797         ret = percpu_counter_compare(&root->fs_info->dirty_metadata_bytes,
3798                                      BTRFS_DIRTY_METADATA_THRESH);
3799         if (ret > 0) {
3800                 balance_dirty_pages_ratelimited(
3801                                    root->fs_info->btree_inode->i_mapping);
3802         }
3803         return;
3804 }
3805 
3806 void btrfs_btree_balance_dirty(struct btrfs_root *root)
3807 {
3808         __btrfs_btree_balance_dirty(root, 1);
3809 }
3810 
3811 void btrfs_btree_balance_dirty_nodelay(struct btrfs_root *root)
3812 {
3813         __btrfs_btree_balance_dirty(root, 0);
3814 }
3815 
3816 int btrfs_read_buffer(struct extent_buffer *buf, u64 parent_transid)
3817 {
3818         struct btrfs_root *root = BTRFS_I(buf->pages[0]->mapping->host)->root;
3819         return btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
3820 }
3821 
3822 static int btrfs_check_super_valid(struct btrfs_fs_info *fs_info,
3823                               int read_only)
3824 {
3825         struct btrfs_super_block *sb = fs_info->super_copy;
3826         int ret = 0;
3827 
3828         if (btrfs_super_root_level(sb) >= BTRFS_MAX_LEVEL) {
3829                 printk(KERN_ERR "BTRFS: tree_root level too big: %d >= %d\n",
3830                                 btrfs_super_root_level(sb), BTRFS_MAX_LEVEL);
3831                 ret = -EINVAL;
3832         }
3833         if (btrfs_super_chunk_root_level(sb) >= BTRFS_MAX_LEVEL) {
3834                 printk(KERN_ERR "BTRFS: chunk_root level too big: %d >= %d\n",
3835                                 btrfs_super_chunk_root_level(sb), BTRFS_MAX_LEVEL);
3836                 ret = -EINVAL;
3837         }
3838         if (btrfs_super_log_root_level(sb) >= BTRFS_MAX_LEVEL) {
3839                 printk(KERN_ERR "BTRFS: log_root level too big: %d >= %d\n",
3840                                 btrfs_super_log_root_level(sb), BTRFS_MAX_LEVEL);
3841                 ret = -EINVAL;
3842         }
3843 
3844         /*
3845          * The common minimum, we don't know if we can trust the nodesize/sectorsize
3846          * items yet, they'll be verified later. Issue just a warning.
3847          */
3848         if (!IS_ALIGNED(btrfs_super_root(sb), 4096))
3849                 printk(KERN_WARNING "BTRFS: tree_root block unaligned: %llu\n",
3850                                 sb->root);
3851         if (!IS_ALIGNED(btrfs_super_chunk_root(sb), 4096))
3852                 printk(KERN_WARNING "BTRFS: tree_root block unaligned: %llu\n",
3853                                 sb->chunk_root);
3854         if (!IS_ALIGNED(btrfs_super_log_root(sb), 4096))
3855                 printk(KERN_WARNING "BTRFS: tree_root block unaligned: %llu\n",
3856                                 btrfs_super_log_root(sb));
3857 
3858         if (memcmp(fs_info->fsid, sb->dev_item.fsid, BTRFS_UUID_SIZE) != 0) {
3859                 printk(KERN_ERR "BTRFS: dev_item UUID does not match fsid: %pU != %pU\n",
3860                                 fs_info->fsid, sb->dev_item.fsid);
3861                 ret = -EINVAL;
3862         }
3863 
3864         /*
3865          * Hint to catch really bogus numbers, bitflips or so, more exact checks are
3866          * done later
3867          */
3868         if (btrfs_super_num_devices(sb) > (1UL << 31))
3869                 printk(KERN_WARNING "BTRFS: suspicious number of devices: %llu\n",
3870                                 btrfs_super_num_devices(sb));
3871 
3872         if (btrfs_super_bytenr(sb) != BTRFS_SUPER_INFO_OFFSET) {
3873                 printk(KERN_ERR "BTRFS: super offset mismatch %llu != %u\n",
3874                                 btrfs_super_bytenr(sb), BTRFS_SUPER_INFO_OFFSET);
3875                 ret = -EINVAL;
3876         }
3877 
3878         /*
3879          * The generation is a global counter, we'll trust it more than the others
3880          * but it's still possible that it's the one that's wrong.
3881          */
3882         if (btrfs_super_generation(sb) < btrfs_super_chunk_root_generation(sb))
3883                 printk(KERN_WARNING
3884                         "BTRFS: suspicious: generation < chunk_root_generation: %llu < %llu\n",
3885                         btrfs_super_generation(sb), btrfs_super_chunk_root_generation(sb));
3886         if (btrfs_super_generation(sb) < btrfs_super_cache_generation(sb)
3887             && btrfs_super_cache_generation(sb) != (u64)-1)
3888                 printk(KERN_WARNING
3889                         "BTRFS: suspicious: generation < cache_generation: %llu < %llu\n",
3890                         btrfs_super_generation(sb), btrfs_super_cache_generation(sb));
3891 
3892         return ret;
3893 }
3894 
3895 static void btrfs_error_commit_super(struct btrfs_root *root)
3896 {
3897         mutex_lock(&root->fs_info->cleaner_mutex);
3898         btrfs_run_delayed_iputs(root);
3899         mutex_unlock(&root->fs_info->cleaner_mutex);
3900 
3901         down_write(&root->fs_info->cleanup_work_sem);
3902         up_write(&root->fs_info->cleanup_work_sem);
3903 
3904         /* cleanup FS via transaction */
3905         btrfs_cleanup_transaction(root);
3906 }
3907 
3908 static void btrfs_destroy_ordered_extents(struct btrfs_root *root)
3909 {
3910         struct btrfs_ordered_extent *ordered;
3911 
3912         spin_lock(&root->ordered_extent_lock);
3913         /*
3914          * This will just short circuit the ordered completion stuff which will
3915          * make sure the ordered extent gets properly cleaned up.
3916          */
3917         list_for_each_entry(ordered, &root->ordered_extents,
3918                             root_extent_list)
3919                 set_bit(BTRFS_ORDERED_IOERR, &ordered->flags);
3920         spin_unlock(&root->ordered_extent_lock);
3921 }
3922 
3923 static void btrfs_destroy_all_ordered_extents(struct btrfs_fs_info *fs_info)
3924 {
3925         struct btrfs_root *root;
3926         struct list_head splice;
3927 
3928         INIT_LIST_HEAD(&splice);
3929 
3930         spin_lock(&fs_info->ordered_root_lock);
3931         list_splice_init(&fs_info->ordered_roots, &splice);
3932         while (!list_empty(&splice)) {
3933                 root = list_first_entry(&splice, struct btrfs_root,
3934                                         ordered_root);
3935                 list_move_tail(&root->ordered_root,
3936                                &fs_info->ordered_roots);
3937 
3938                 spin_unlock(&fs_info->ordered_root_lock);
3939                 btrfs_destroy_ordered_extents(root);
3940 
3941                 cond_resched();
3942                 spin_lock(&fs_info->ordered_root_lock);
3943         }
3944         spin_unlock(&fs_info->ordered_root_lock);
3945 
3946         /*
3947          * We need this here because if we've been flipped read-only we won't
3948          * get sync() from the umount, so we need to make sure any ordered
3949          * extents that haven't had their dirty pages IO start writeout yet
3950          * actually get run and error out properly.
3951          */
3952         btrfs_wait_ordered_roots(fs_info, -1);
3953 }
3954 
3955 static int btrfs_destroy_delayed_refs(struct btrfs_transaction *trans,
3956                                       struct btrfs_root *root)
3957 {
3958         struct rb_node *node;
3959         struct btrfs_delayed_ref_root *delayed_refs;
3960         struct btrfs_delayed_ref_node *ref;
3961         int ret = 0;
3962 
3963         delayed_refs = &trans->delayed_refs;
3964 
3965         spin_lock(&delayed_refs->lock);
3966         if (atomic_read(&delayed_refs->num_entries) == 0) {
3967                 spin_unlock(&delayed_refs->lock);
3968                 btrfs_info(root->fs_info, "delayed_refs has NO entry");
3969                 return ret;
3970         }
3971 
3972         while ((node = rb_first(&delayed_refs->href_root)) != NULL) {
3973                 struct btrfs_delayed_ref_head *head;
3974                 bool pin_bytes = false;
3975 
3976                 head = rb_entry(node, struct btrfs_delayed_ref_head,
3977                                 href_node);
3978                 if (!mutex_trylock(&head->mutex)) {
3979                         atomic_inc(&head->node.refs);
3980                         spin_unlock(&delayed_refs->lock);
3981 
3982                         mutex_lock(&head->mutex);
3983                         mutex_unlock(&head->mutex);
3984                         btrfs_put_delayed_ref(&head->node);
3985                         spin_lock(&delayed_refs->lock);
3986                         continue;
3987                 }
3988                 spin_lock(&head->lock);
3989                 while ((node = rb_first(&head->ref_root)) != NULL) {
3990                         ref = rb_entry(node, struct btrfs_delayed_ref_node,
3991                                        rb_node);
3992                         ref->in_tree = 0;
3993                         rb_erase(&ref->rb_node, &head->ref_root);
3994                         atomic_dec(&delayed_refs->num_entries);
3995                         btrfs_put_delayed_ref(ref);
3996                 }
3997                 if (head->must_insert_reserved)
3998                         pin_bytes = true;
3999                 btrfs_free_delayed_extent_op(head->extent_op);
4000                 delayed_refs->num_heads--;
4001                 if (head->processing == 0)
4002                         delayed_refs->num_heads_ready--;
4003                 atomic_dec(&delayed_refs->num_entries);
4004                 head->node.in_tree = 0;
4005                 rb_erase(&head->href_node, &delayed_refs->href_root);
4006                 spin_unlock(&head->lock);
4007                 spin_unlock(&delayed_refs->lock);
4008                 mutex_unlock(&head->mutex);
4009 
4010                 if (pin_bytes)
4011                         btrfs_pin_extent(root, head->node.bytenr,
4012                                          head->node.num_bytes, 1);
4013                 btrfs_put_delayed_ref(&head->node);
4014                 cond_resched();
4015                 spin_lock(&delayed_refs->lock);
4016         }
4017 
4018         spin_unlock(&delayed_refs->lock);
4019 
4020         return ret;
4021 }
4022 
4023 static void btrfs_destroy_delalloc_inodes(struct btrfs_root *root)
4024 {
4025         struct btrfs_inode *btrfs_inode;
4026         struct list_head splice;
4027 
4028         INIT_LIST_HEAD(&splice);
4029 
4030         spin_lock(&root->delalloc_lock);
4031         list_splice_init(&root->delalloc_inodes, &splice);
4032 
4033         while (!list_empty(&splice)) {
4034                 btrfs_inode = list_first_entry(&splice, struct btrfs_inode,
4035                                                delalloc_inodes);
4036 
4037                 list_del_init(&btrfs_inode->delalloc_inodes);
4038                 clear_bit(BTRFS_INODE_IN_DELALLOC_LIST,
4039                           &btrfs_inode->runtime_flags);
4040                 spin_unlock(&root->delalloc_lock);
4041 
4042                 btrfs_invalidate_inodes(btrfs_inode->root);
4043 
4044                 spin_lock(&root->delalloc_lock);
4045         }
4046 
4047         spin_unlock(&root->delalloc_lock);
4048 }
4049 
4050 static void btrfs_destroy_all_delalloc_inodes(struct btrfs_fs_info *fs_info)
4051 {
4052         struct btrfs_root *root;
4053         struct list_head splice;
4054 
4055         INIT_LIST_HEAD(&splice);
4056 
4057         spin_lock(&fs_info->delalloc_root_lock);
4058         list_splice_init(&fs_info->delalloc_roots, &splice);
4059         while (!list_empty(&splice)) {
4060                 root = list_first_entry(&splice, struct btrfs_root,
4061                                          delalloc_root);
4062                 list_del_init(&root->delalloc_root);
4063                 root = btrfs_grab_fs_root(root);
4064                 BUG_ON(!root);
4065                 spin_unlock(&fs_info->delalloc_root_lock);
4066 
4067                 btrfs_destroy_delalloc_inodes(root);
4068                 btrfs_put_fs_root(root);
4069 
4070                 spin_lock(&fs_info->delalloc_root_lock);
4071         }
4072         spin_unlock(&fs_info->delalloc_root_lock);
4073 }
4074 
4075 static int btrfs_destroy_marked_extents(struct btrfs_root *root,
4076                                         struct extent_io_tree *dirty_pages,
4077                                         int mark)
4078 {
4079         int ret;
4080         struct extent_buffer *eb;
4081         u64 start = 0;
4082         u64 end;
4083 
4084         while (1) {
4085                 ret = find_first_extent_bit(dirty_pages, start, &start, &end,
4086                                             mark, NULL);
4087                 if (ret)
4088                         break;
4089 
4090                 clear_extent_bits(dirty_pages, start, end, mark, GFP_NOFS);
4091                 while (start <= end) {
4092                         eb = btrfs_find_tree_block(root, start);
4093                         start += root->nodesize;
4094                         if (!eb)
4095                                 continue;
4096                         wait_on_extent_buffer_writeback(eb);
4097 
4098                         if (test_and_clear_bit(EXTENT_BUFFER_DIRTY,
4099                                                &eb->bflags))
4100                                 clear_extent_buffer_dirty(eb);
4101                         free_extent_buffer_stale(eb);
4102                 }
4103         }
4104 
4105         return ret;
4106 }
4107 
4108 static int btrfs_destroy_pinned_extent(struct btrfs_root *root,
4109                                        struct extent_io_tree *pinned_extents)
4110 {
4111         struct extent_io_tree *unpin;
4112         u64 start;
4113         u64 end;
4114         int ret;
4115         bool loop = true;
4116 
4117         unpin = pinned_extents;
4118 again:
4119         while (1) {
4120                 ret = find_first_extent_bit(unpin, 0, &start, &end,
4121                                             EXTENT_DIRTY, NULL);
4122                 if (ret)
4123                         break;
4124 
4125                 clear_extent_dirty(unpin, start, end, GFP_NOFS);
4126                 btrfs_error_unpin_extent_range(root, start, end);
4127                 cond_resched();
4128         }
4129 
4130         if (loop) {
4131                 if (unpin == &root->fs_info->freed_extents[0])
4132                         unpin = &root->fs_info->freed_extents[1];
4133                 else
4134                         unpin = &root->fs_info->freed_extents[0];
4135                 loop = false;
4136                 goto again;
4137         }
4138 
4139         return 0;
4140 }
4141 
4142 static void btrfs_free_pending_ordered(struct btrfs_transaction *cur_trans,
4143                                        struct btrfs_fs_info *fs_info)
4144 {
4145         struct btrfs_ordered_extent *ordered;
4146 
4147         spin_lock(&fs_info->trans_lock);
4148         while (!list_empty(&cur_trans->pending_ordered)) {
4149                 ordered = list_first_entry(&cur_trans->pending_ordered,
4150                                            struct btrfs_ordered_extent,
4151                                            trans_list);
4152                 list_del_init(&ordered->trans_list);
4153                 spin_unlock(&fs_info->trans_lock);
4154 
4155                 btrfs_put_ordered_extent(ordered);
4156                 spin_lock(&fs_info->trans_lock);
4157         }
4158         spin_unlock(&fs_info->trans_lock);
4159 }
4160 
4161 void btrfs_cleanup_one_transaction(struct btrfs_transaction *cur_trans,
4162                                    struct btrfs_root *root)
4163 {
4164         btrfs_destroy_delayed_refs(cur_trans, root);
4165 
4166         cur_trans->state = TRANS_STATE_COMMIT_START;
4167         wake_up(&root->fs_info->transaction_blocked_wait);
4168 
4169         cur_trans->state = TRANS_STATE_UNBLOCKED;
4170         wake_up(&root->fs_info->transaction_wait);
4171 
4172         btrfs_free_pending_ordered(cur_trans, root->fs_info);
4173         btrfs_destroy_delayed_inodes(root);
4174         btrfs_assert_delayed_root_empty(root);
4175 
4176         btrfs_destroy_marked_extents(root, &cur_trans->dirty_pages,
4177                                      EXTENT_DIRTY);
4178         btrfs_destroy_pinned_extent(root,
4179                                     root->fs_info->pinned_extents);
4180 
4181         cur_trans->state =TRANS_STATE_COMPLETED;
4182         wake_up(&cur_trans->commit_wait);
4183 
4184         /*
4185         memset(cur_trans, 0, sizeof(*cur_trans));
4186         kmem_cache_free(btrfs_transaction_cachep, cur_trans);
4187         */
4188 }
4189 
4190 static int btrfs_cleanup_transaction(struct btrfs_root *root)
4191 {
4192         struct btrfs_transaction *t;
4193 
4194         mutex_lock(&root->fs_info->transaction_kthread_mutex);
4195 
4196         spin_lock(&root->fs_info->trans_lock);
4197         while (!list_empty(&root->fs_info->trans_list)) {
4198                 t = list_first_entry(&root->fs_info->trans_list,
4199                                      struct btrfs_transaction, list);
4200                 if (t->state >= TRANS_STATE_COMMIT_START) {
4201                         atomic_inc(&t->use_count);
4202                         spin_unlock(&root->fs_info->trans_lock);
4203                         btrfs_wait_for_commit(root, t->transid);
4204                         btrfs_put_transaction(t);
4205                         spin_lock(&root->fs_info->trans_lock);
4206                         continue;
4207                 }
4208                 if (t == root->fs_info->running_transaction) {
4209                         t->state = TRANS_STATE_COMMIT_DOING;
4210                         spin_unlock(&root->fs_info->trans_lock);
4211                         /*
4212                          * We wait for 0 num_writers since we don't hold a trans
4213                          * handle open currently for this transaction.
4214                          */
4215                         wait_event(t->writer_wait,
4216                                    atomic_read(&t->num_writers) == 0);
4217                 } else {
4218                         spin_unlock(&root->fs_info->trans_lock);
4219                 }
4220                 btrfs_cleanup_one_transaction(t, root);
4221 
4222                 spin_lock(&root->fs_info->trans_lock);
4223                 if (t == root->fs_info->running_transaction)
4224                         root->fs_info->running_transaction = NULL;
4225                 list_del_init(&t->list);
4226                 spin_unlock(&root->fs_info->trans_lock);
4227 
4228                 btrfs_put_transaction(t);
4229                 trace_btrfs_transaction_commit(root);
4230                 spin_lock(&root->fs_info->trans_lock);
4231         }
4232         spin_unlock(&root->fs_info->trans_lock);
4233         btrfs_destroy_all_ordered_extents(root->fs_info);
4234         btrfs_destroy_delayed_inodes(root);
4235         btrfs_assert_delayed_root_empty(root);
4236         btrfs_destroy_pinned_extent(root, root->fs_info->pinned_extents);
4237         btrfs_destroy_all_delalloc_inodes(root->fs_info);
4238         mutex_unlock(&root->fs_info->transaction_kthread_mutex);
4239 
4240         return 0;
4241 }
4242 
4243 static struct extent_io_ops btree_extent_io_ops = {
4244         .readpage_end_io_hook = btree_readpage_end_io_hook,
4245         .readpage_io_failed_hook = btree_io_failed_hook,
4246         .submit_bio_hook = btree_submit_bio_hook,
4247         /* note we're sharing with inode.c for the merge bio hook */
4248         .merge_bio_hook = btrfs_merge_bio_hook,
4249 };
4250 

~ [ 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