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

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  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/slab.h>
 29 #include <linux/migrate.h>
 30 #include <linux/ratelimit.h>
 31 #include <linux/uuid.h>
 32 #include <linux/semaphore.h>
 33 #include <asm/unaligned.h>
 34 #include "ctree.h"
 35 #include "disk-io.h"
 36 #include "hash.h"
 37 #include "transaction.h"
 38 #include "btrfs_inode.h"
 39 #include "volumes.h"
 40 #include "print-tree.h"
 41 #include "locking.h"
 42 #include "tree-log.h"
 43 #include "free-space-cache.h"
 44 #include "free-space-tree.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 #include "compression.h"
 53 
 54 #ifdef CONFIG_X86
 55 #include <asm/cpufeature.h>
 56 #endif
 57 
 58 #define BTRFS_SUPER_FLAG_SUPP   (BTRFS_HEADER_FLAG_WRITTEN |\
 59                                  BTRFS_HEADER_FLAG_RELOC |\
 60                                  BTRFS_SUPER_FLAG_ERROR |\
 61                                  BTRFS_SUPER_FLAG_SEEDING |\
 62                                  BTRFS_SUPER_FLAG_METADUMP)
 63 
 64 static const struct extent_io_ops btree_extent_io_ops;
 65 static void end_workqueue_fn(struct btrfs_work *work);
 66 static void free_fs_root(struct btrfs_root *root);
 67 static int btrfs_check_super_valid(struct btrfs_fs_info *fs_info,
 68                                     int read_only);
 69 static void btrfs_destroy_ordered_extents(struct btrfs_root *root);
 70 static int btrfs_destroy_delayed_refs(struct btrfs_transaction *trans,
 71                                       struct btrfs_root *root);
 72 static void btrfs_destroy_delalloc_inodes(struct btrfs_root *root);
 73 static int btrfs_destroy_marked_extents(struct btrfs_root *root,
 74                                         struct extent_io_tree *dirty_pages,
 75                                         int mark);
 76 static int btrfs_destroy_pinned_extent(struct btrfs_root *root,
 77                                        struct extent_io_tree *pinned_extents);
 78 static int btrfs_cleanup_transaction(struct btrfs_root *root);
 79 static void btrfs_error_commit_super(struct btrfs_root *root);
 80 
 81 /*
 82  * btrfs_end_io_wq structs are used to do processing in task context when an IO
 83  * is complete.  This is used during reads to verify checksums, and it is used
 84  * by writes to insert metadata for new file extents after IO is complete.
 85  */
 86 struct btrfs_end_io_wq {
 87         struct bio *bio;
 88         bio_end_io_t *end_io;
 89         void *private;
 90         struct btrfs_fs_info *info;
 91         int error;
 92         enum btrfs_wq_endio_type metadata;
 93         struct list_head list;
 94         struct btrfs_work work;
 95 };
 96 
 97 static struct kmem_cache *btrfs_end_io_wq_cache;
 98 
 99 int __init btrfs_end_io_wq_init(void)
100 {
101         btrfs_end_io_wq_cache = kmem_cache_create("btrfs_end_io_wq",
102                                         sizeof(struct btrfs_end_io_wq),
103                                         0,
104                                         SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD,
105                                         NULL);
106         if (!btrfs_end_io_wq_cache)
107                 return -ENOMEM;
108         return 0;
109 }
110 
111 void btrfs_end_io_wq_exit(void)
112 {
113         kmem_cache_destroy(btrfs_end_io_wq_cache);
114 }
115 
116 /*
117  * async submit bios are used to offload expensive checksumming
118  * onto the worker threads.  They checksum file and metadata bios
119  * just before they are sent down the IO stack.
120  */
121 struct async_submit_bio {
122         struct inode *inode;
123         struct bio *bio;
124         struct list_head list;
125         extent_submit_bio_hook_t *submit_bio_start;
126         extent_submit_bio_hook_t *submit_bio_done;
127         int rw;
128         int mirror_num;
129         unsigned long bio_flags;
130         /*
131          * bio_offset is optional, can be used if the pages in the bio
132          * can't tell us where in the file the bio should go
133          */
134         u64 bio_offset;
135         struct btrfs_work work;
136         int error;
137 };
138 
139 /*
140  * Lockdep class keys for extent_buffer->lock's in this root.  For a given
141  * eb, the lockdep key is determined by the btrfs_root it belongs to and
142  * the level the eb occupies in the tree.
143  *
144  * Different roots are used for different purposes and may nest inside each
145  * other and they require separate keysets.  As lockdep keys should be
146  * static, assign keysets according to the purpose of the root as indicated
147  * by btrfs_root->objectid.  This ensures that all special purpose roots
148  * have separate keysets.
149  *
150  * Lock-nesting across peer nodes is always done with the immediate parent
151  * node locked thus preventing deadlock.  As lockdep doesn't know this, use
152  * subclass to avoid triggering lockdep warning in such cases.
153  *
154  * The key is set by the readpage_end_io_hook after the buffer has passed
155  * csum validation but before the pages are unlocked.  It is also set by
156  * btrfs_init_new_buffer on freshly allocated blocks.
157  *
158  * We also add a check to make sure the highest level of the tree is the
159  * same as our lockdep setup here.  If BTRFS_MAX_LEVEL changes, this code
160  * needs update as well.
161  */
162 #ifdef CONFIG_DEBUG_LOCK_ALLOC
163 # if BTRFS_MAX_LEVEL != 8
164 #  error
165 # endif
166 
167 static struct btrfs_lockdep_keyset {
168         u64                     id;             /* root objectid */
169         const char              *name_stem;     /* lock name stem */
170         char                    names[BTRFS_MAX_LEVEL + 1][20];
171         struct lock_class_key   keys[BTRFS_MAX_LEVEL + 1];
172 } btrfs_lockdep_keysets[] = {
173         { .id = BTRFS_ROOT_TREE_OBJECTID,       .name_stem = "root"     },
174         { .id = BTRFS_EXTENT_TREE_OBJECTID,     .name_stem = "extent"   },
175         { .id = BTRFS_CHUNK_TREE_OBJECTID,      .name_stem = "chunk"    },
176         { .id = BTRFS_DEV_TREE_OBJECTID,        .name_stem = "dev"      },
177         { .id = BTRFS_FS_TREE_OBJECTID,         .name_stem = "fs"       },
178         { .id = BTRFS_CSUM_TREE_OBJECTID,       .name_stem = "csum"     },
179         { .id = BTRFS_QUOTA_TREE_OBJECTID,      .name_stem = "quota"    },
180         { .id = BTRFS_TREE_LOG_OBJECTID,        .name_stem = "log"      },
181         { .id = BTRFS_TREE_RELOC_OBJECTID,      .name_stem = "treloc"   },
182         { .id = BTRFS_DATA_RELOC_TREE_OBJECTID, .name_stem = "dreloc"   },
183         { .id = BTRFS_UUID_TREE_OBJECTID,       .name_stem = "uuid"     },
184         { .id = BTRFS_FREE_SPACE_TREE_OBJECTID, .name_stem = "free-space" },
185         { .id = 0,                              .name_stem = "tree"     },
186 };
187 
188 void __init btrfs_init_lockdep(void)
189 {
190         int i, j;
191 
192         /* initialize lockdep class names */
193         for (i = 0; i < ARRAY_SIZE(btrfs_lockdep_keysets); i++) {
194                 struct btrfs_lockdep_keyset *ks = &btrfs_lockdep_keysets[i];
195 
196                 for (j = 0; j < ARRAY_SIZE(ks->names); j++)
197                         snprintf(ks->names[j], sizeof(ks->names[j]),
198                                  "btrfs-%s-%02d", ks->name_stem, j);
199         }
200 }
201 
202 void btrfs_set_buffer_lockdep_class(u64 objectid, struct extent_buffer *eb,
203                                     int level)
204 {
205         struct btrfs_lockdep_keyset *ks;
206 
207         BUG_ON(level >= ARRAY_SIZE(ks->keys));
208 
209         /* find the matching keyset, id 0 is the default entry */
210         for (ks = btrfs_lockdep_keysets; ks->id; ks++)
211                 if (ks->id == objectid)
212                         break;
213 
214         lockdep_set_class_and_name(&eb->lock,
215                                    &ks->keys[level], ks->names[level]);
216 }
217 
218 #endif
219 
220 /*
221  * extents on the btree inode are pretty simple, there's one extent
222  * that covers the entire device
223  */
224 static struct extent_map *btree_get_extent(struct inode *inode,
225                 struct page *page, size_t pg_offset, u64 start, u64 len,
226                 int create)
227 {
228         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
229         struct extent_map *em;
230         int ret;
231 
232         read_lock(&em_tree->lock);
233         em = lookup_extent_mapping(em_tree, start, len);
234         if (em) {
235                 em->bdev =
236                         BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
237                 read_unlock(&em_tree->lock);
238                 goto out;
239         }
240         read_unlock(&em_tree->lock);
241 
242         em = alloc_extent_map();
243         if (!em) {
244                 em = ERR_PTR(-ENOMEM);
245                 goto out;
246         }
247         em->start = 0;
248         em->len = (u64)-1;
249         em->block_len = (u64)-1;
250         em->block_start = 0;
251         em->bdev = BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
252 
253         write_lock(&em_tree->lock);
254         ret = add_extent_mapping(em_tree, em, 0);
255         if (ret == -EEXIST) {
256                 free_extent_map(em);
257                 em = lookup_extent_mapping(em_tree, start, len);
258                 if (!em)
259                         em = ERR_PTR(-EIO);
260         } else if (ret) {
261                 free_extent_map(em);
262                 em = ERR_PTR(ret);
263         }
264         write_unlock(&em_tree->lock);
265 
266 out:
267         return em;
268 }
269 
270 u32 btrfs_csum_data(char *data, u32 seed, size_t len)
271 {
272         return btrfs_crc32c(seed, data, len);
273 }
274 
275 void btrfs_csum_final(u32 crc, char *result)
276 {
277         put_unaligned_le32(~crc, result);
278 }
279 
280 /*
281  * compute the csum for a btree block, and either verify it or write it
282  * into the csum field of the block.
283  */
284 static int csum_tree_block(struct btrfs_fs_info *fs_info,
285                            struct extent_buffer *buf,
286                            int verify)
287 {
288         u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
289         char *result = NULL;
290         unsigned long len;
291         unsigned long cur_len;
292         unsigned long offset = BTRFS_CSUM_SIZE;
293         char *kaddr;
294         unsigned long map_start;
295         unsigned long map_len;
296         int err;
297         u32 crc = ~(u32)0;
298         unsigned long inline_result;
299 
300         len = buf->len - offset;
301         while (len > 0) {
302                 err = map_private_extent_buffer(buf, offset, 32,
303                                         &kaddr, &map_start, &map_len);
304                 if (err)
305                         return err;
306                 cur_len = min(len, map_len - (offset - map_start));
307                 crc = btrfs_csum_data(kaddr + offset - map_start,
308                                       crc, cur_len);
309                 len -= cur_len;
310                 offset += cur_len;
311         }
312         if (csum_size > sizeof(inline_result)) {
313                 result = kzalloc(csum_size, GFP_NOFS);
314                 if (!result)
315                         return -ENOMEM;
316         } else {
317                 result = (char *)&inline_result;
318         }
319 
320         btrfs_csum_final(crc, result);
321 
322         if (verify) {
323                 if (memcmp_extent_buffer(buf, result, 0, csum_size)) {
324                         u32 val;
325                         u32 found = 0;
326                         memcpy(&found, result, csum_size);
327 
328                         read_extent_buffer(buf, &val, 0, csum_size);
329                         btrfs_warn_rl(fs_info,
330                                 "%s checksum verify failed on %llu wanted %X found %X "
331                                 "level %d",
332                                 fs_info->sb->s_id, buf->start,
333                                 val, found, btrfs_header_level(buf));
334                         if (result != (char *)&inline_result)
335                                 kfree(result);
336                         return -EUCLEAN;
337                 }
338         } else {
339                 write_extent_buffer(buf, result, 0, csum_size);
340         }
341         if (result != (char *)&inline_result)
342                 kfree(result);
343         return 0;
344 }
345 
346 /*
347  * we can't consider a given block up to date unless the transid of the
348  * block matches the transid in the parent node's pointer.  This is how we
349  * detect blocks that either didn't get written at all or got written
350  * in the wrong place.
351  */
352 static int verify_parent_transid(struct extent_io_tree *io_tree,
353                                  struct extent_buffer *eb, u64 parent_transid,
354                                  int atomic)
355 {
356         struct extent_state *cached_state = NULL;
357         int ret;
358         bool need_lock = (current->journal_info == BTRFS_SEND_TRANS_STUB);
359 
360         if (!parent_transid || btrfs_header_generation(eb) == parent_transid)
361                 return 0;
362 
363         if (atomic)
364                 return -EAGAIN;
365 
366         if (need_lock) {
367                 btrfs_tree_read_lock(eb);
368                 btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK);
369         }
370 
371         lock_extent_bits(io_tree, eb->start, eb->start + eb->len - 1,
372                          &cached_state);
373         if (extent_buffer_uptodate(eb) &&
374             btrfs_header_generation(eb) == parent_transid) {
375                 ret = 0;
376                 goto out;
377         }
378         btrfs_err_rl(eb->fs_info,
379                 "parent transid verify failed on %llu wanted %llu found %llu",
380                         eb->start,
381                         parent_transid, btrfs_header_generation(eb));
382         ret = 1;
383 
384         /*
385          * Things reading via commit roots that don't have normal protection,
386          * like send, can have a really old block in cache that may point at a
387          * block that has been free'd and re-allocated.  So don't clear uptodate
388          * if we find an eb that is under IO (dirty/writeback) because we could
389          * end up reading in the stale data and then writing it back out and
390          * making everybody very sad.
391          */
392         if (!extent_buffer_under_io(eb))
393                 clear_extent_buffer_uptodate(eb);
394 out:
395         unlock_extent_cached(io_tree, eb->start, eb->start + eb->len - 1,
396                              &cached_state, GFP_NOFS);
397         if (need_lock)
398                 btrfs_tree_read_unlock_blocking(eb);
399         return ret;
400 }
401 
402 /*
403  * Return 0 if the superblock checksum type matches the checksum value of that
404  * algorithm. Pass the raw disk superblock data.
405  */
406 static int btrfs_check_super_csum(char *raw_disk_sb)
407 {
408         struct btrfs_super_block *disk_sb =
409                 (struct btrfs_super_block *)raw_disk_sb;
410         u16 csum_type = btrfs_super_csum_type(disk_sb);
411         int ret = 0;
412 
413         if (csum_type == BTRFS_CSUM_TYPE_CRC32) {
414                 u32 crc = ~(u32)0;
415                 const int csum_size = sizeof(crc);
416                 char result[csum_size];
417 
418                 /*
419                  * The super_block structure does not span the whole
420                  * BTRFS_SUPER_INFO_SIZE range, we expect that the unused space
421                  * is filled with zeros and is included in the checkum.
422                  */
423                 crc = btrfs_csum_data(raw_disk_sb + BTRFS_CSUM_SIZE,
424                                 crc, BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE);
425                 btrfs_csum_final(crc, result);
426 
427                 if (memcmp(raw_disk_sb, result, csum_size))
428                         ret = 1;
429         }
430 
431         if (csum_type >= ARRAY_SIZE(btrfs_csum_sizes)) {
432                 printk(KERN_ERR "BTRFS: unsupported checksum algorithm %u\n",
433                                 csum_type);
434                 ret = 1;
435         }
436 
437         return ret;
438 }
439 
440 /*
441  * helper to read a given tree block, doing retries as required when
442  * the checksums don't match and we have alternate mirrors to try.
443  */
444 static int btree_read_extent_buffer_pages(struct btrfs_root *root,
445                                           struct extent_buffer *eb,
446                                           u64 start, u64 parent_transid)
447 {
448         struct extent_io_tree *io_tree;
449         int failed = 0;
450         int ret;
451         int num_copies = 0;
452         int mirror_num = 0;
453         int failed_mirror = 0;
454 
455         clear_bit(EXTENT_BUFFER_CORRUPT, &eb->bflags);
456         io_tree = &BTRFS_I(root->fs_info->btree_inode)->io_tree;
457         while (1) {
458                 ret = read_extent_buffer_pages(io_tree, eb, start,
459                                                WAIT_COMPLETE,
460                                                btree_get_extent, mirror_num);
461                 if (!ret) {
462                         if (!verify_parent_transid(io_tree, eb,
463                                                    parent_transid, 0))
464                                 break;
465                         else
466                                 ret = -EIO;
467                 }
468 
469                 /*
470                  * This buffer's crc is fine, but its contents are corrupted, so
471                  * there is no reason to read the other copies, they won't be
472                  * any less wrong.
473                  */
474                 if (test_bit(EXTENT_BUFFER_CORRUPT, &eb->bflags))
475                         break;
476 
477                 num_copies = btrfs_num_copies(root->fs_info,
478                                               eb->start, eb->len);
479                 if (num_copies == 1)
480                         break;
481 
482                 if (!failed_mirror) {
483                         failed = 1;
484                         failed_mirror = eb->read_mirror;
485                 }
486 
487                 mirror_num++;
488                 if (mirror_num == failed_mirror)
489                         mirror_num++;
490 
491                 if (mirror_num > num_copies)
492                         break;
493         }
494 
495         if (failed && !ret && failed_mirror)
496                 repair_eb_io_failure(root, eb, failed_mirror);
497 
498         return ret;
499 }
500 
501 /*
502  * checksum a dirty tree block before IO.  This has extra checks to make sure
503  * we only fill in the checksum field in the first page of a multi-page block
504  */
505 
506 static int csum_dirty_buffer(struct btrfs_fs_info *fs_info, struct page *page)
507 {
508         u64 start = page_offset(page);
509         u64 found_start;
510         struct extent_buffer *eb;
511 
512         eb = (struct extent_buffer *)page->private;
513         if (page != eb->pages[0])
514                 return 0;
515 
516         found_start = btrfs_header_bytenr(eb);
517         /*
518          * Please do not consolidate these warnings into a single if.
519          * It is useful to know what went wrong.
520          */
521         if (WARN_ON(found_start != start))
522                 return -EUCLEAN;
523         if (WARN_ON(!PageUptodate(page)))
524                 return -EUCLEAN;
525 
526         ASSERT(memcmp_extent_buffer(eb, fs_info->fsid,
527                         btrfs_header_fsid(), BTRFS_FSID_SIZE) == 0);
528 
529         return csum_tree_block(fs_info, eb, 0);
530 }
531 
532 static int check_tree_block_fsid(struct btrfs_fs_info *fs_info,
533                                  struct extent_buffer *eb)
534 {
535         struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
536         u8 fsid[BTRFS_UUID_SIZE];
537         int ret = 1;
538 
539         read_extent_buffer(eb, fsid, btrfs_header_fsid(), BTRFS_FSID_SIZE);
540         while (fs_devices) {
541                 if (!memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE)) {
542                         ret = 0;
543                         break;
544                 }
545                 fs_devices = fs_devices->seed;
546         }
547         return ret;
548 }
549 
550 #define CORRUPT(reason, eb, root, slot)                         \
551         btrfs_crit(root->fs_info, "corrupt leaf, %s: block=%llu,"       \
552                    "root=%llu, slot=%d", reason,                        \
553                btrfs_header_bytenr(eb), root->objectid, slot)
554 
555 static noinline int check_leaf(struct btrfs_root *root,
556                                struct extent_buffer *leaf)
557 {
558         struct btrfs_key key;
559         struct btrfs_key leaf_key;
560         u32 nritems = btrfs_header_nritems(leaf);
561         int slot;
562 
563         if (nritems == 0)
564                 return 0;
565 
566         /* Check the 0 item */
567         if (btrfs_item_offset_nr(leaf, 0) + btrfs_item_size_nr(leaf, 0) !=
568             BTRFS_LEAF_DATA_SIZE(root)) {
569                 CORRUPT("invalid item offset size pair", leaf, root, 0);
570                 return -EIO;
571         }
572 
573         /*
574          * Check to make sure each items keys are in the correct order and their
575          * offsets make sense.  We only have to loop through nritems-1 because
576          * we check the current slot against the next slot, which verifies the
577          * next slot's offset+size makes sense and that the current's slot
578          * offset is correct.
579          */
580         for (slot = 0; slot < nritems - 1; slot++) {
581                 btrfs_item_key_to_cpu(leaf, &leaf_key, slot);
582                 btrfs_item_key_to_cpu(leaf, &key, slot + 1);
583 
584                 /* Make sure the keys are in the right order */
585                 if (btrfs_comp_cpu_keys(&leaf_key, &key) >= 0) {
586                         CORRUPT("bad key order", leaf, root, slot);
587                         return -EIO;
588                 }
589 
590                 /*
591                  * Make sure the offset and ends are right, remember that the
592                  * item data starts at the end of the leaf and grows towards the
593                  * front.
594                  */
595                 if (btrfs_item_offset_nr(leaf, slot) !=
596                         btrfs_item_end_nr(leaf, slot + 1)) {
597                         CORRUPT("slot offset bad", leaf, root, slot);
598                         return -EIO;
599                 }
600 
601                 /*
602                  * Check to make sure that we don't point outside of the leaf,
603                  * just incase all the items are consistent to eachother, but
604                  * all point outside of the leaf.
605                  */
606                 if (btrfs_item_end_nr(leaf, slot) >
607                     BTRFS_LEAF_DATA_SIZE(root)) {
608                         CORRUPT("slot end outside of leaf", leaf, root, slot);
609                         return -EIO;
610                 }
611         }
612 
613         return 0;
614 }
615 
616 static int btree_readpage_end_io_hook(struct btrfs_io_bio *io_bio,
617                                       u64 phy_offset, struct page *page,
618                                       u64 start, u64 end, int mirror)
619 {
620         u64 found_start;
621         int found_level;
622         struct extent_buffer *eb;
623         struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
624         struct btrfs_fs_info *fs_info = root->fs_info;
625         int ret = 0;
626         int reads_done;
627 
628         if (!page->private)
629                 goto out;
630 
631         eb = (struct extent_buffer *)page->private;
632 
633         /* the pending IO might have been the only thing that kept this buffer
634          * in memory.  Make sure we have a ref for all this other checks
635          */
636         extent_buffer_get(eb);
637 
638         reads_done = atomic_dec_and_test(&eb->io_pages);
639         if (!reads_done)
640                 goto err;
641 
642         eb->read_mirror = mirror;
643         if (test_bit(EXTENT_BUFFER_READ_ERR, &eb->bflags)) {
644                 ret = -EIO;
645                 goto err;
646         }
647 
648         found_start = btrfs_header_bytenr(eb);
649         if (found_start != eb->start) {
650                 btrfs_err_rl(fs_info, "bad tree block start %llu %llu",
651                              found_start, eb->start);
652                 ret = -EIO;
653                 goto err;
654         }
655         if (check_tree_block_fsid(fs_info, eb)) {
656                 btrfs_err_rl(fs_info, "bad fsid on block %llu",
657                              eb->start);
658                 ret = -EIO;
659                 goto err;
660         }
661         found_level = btrfs_header_level(eb);
662         if (found_level >= BTRFS_MAX_LEVEL) {
663                 btrfs_err(fs_info, "bad tree block level %d",
664                           (int)btrfs_header_level(eb));
665                 ret = -EIO;
666                 goto err;
667         }
668 
669         btrfs_set_buffer_lockdep_class(btrfs_header_owner(eb),
670                                        eb, found_level);
671 
672         ret = csum_tree_block(fs_info, eb, 1);
673         if (ret)
674                 goto err;
675 
676         /*
677          * If this is a leaf block and it is corrupt, set the corrupt bit so
678          * that we don't try and read the other copies of this block, just
679          * return -EIO.
680          */
681         if (found_level == 0 && check_leaf(root, eb)) {
682                 set_bit(EXTENT_BUFFER_CORRUPT, &eb->bflags);
683                 ret = -EIO;
684         }
685 
686         if (!ret)
687                 set_extent_buffer_uptodate(eb);
688 err:
689         if (reads_done &&
690             test_and_clear_bit(EXTENT_BUFFER_READAHEAD, &eb->bflags))
691                 btree_readahead_hook(fs_info, eb, eb->start, ret);
692 
693         if (ret) {
694                 /*
695                  * our io error hook is going to dec the io pages
696                  * again, we have to make sure it has something
697                  * to decrement
698                  */
699                 atomic_inc(&eb->io_pages);
700                 clear_extent_buffer_uptodate(eb);
701         }
702         free_extent_buffer(eb);
703 out:
704         return ret;
705 }
706 
707 static int btree_io_failed_hook(struct page *page, int failed_mirror)
708 {
709         struct extent_buffer *eb;
710 
711         eb = (struct extent_buffer *)page->private;
712         set_bit(EXTENT_BUFFER_READ_ERR, &eb->bflags);
713         eb->read_mirror = failed_mirror;
714         atomic_dec(&eb->io_pages);
715         if (test_and_clear_bit(EXTENT_BUFFER_READAHEAD, &eb->bflags))
716                 btree_readahead_hook(eb->fs_info, eb, eb->start, -EIO);
717         return -EIO;    /* we fixed nothing */
718 }
719 
720 static void end_workqueue_bio(struct bio *bio)
721 {
722         struct btrfs_end_io_wq *end_io_wq = bio->bi_private;
723         struct btrfs_fs_info *fs_info;
724         struct btrfs_workqueue *wq;
725         btrfs_work_func_t func;
726 
727         fs_info = end_io_wq->info;
728         end_io_wq->error = bio->bi_error;
729 
730         if (bio->bi_rw & REQ_WRITE) {
731                 if (end_io_wq->metadata == BTRFS_WQ_ENDIO_METADATA) {
732                         wq = fs_info->endio_meta_write_workers;
733                         func = btrfs_endio_meta_write_helper;
734                 } else if (end_io_wq->metadata == BTRFS_WQ_ENDIO_FREE_SPACE) {
735                         wq = fs_info->endio_freespace_worker;
736                         func = btrfs_freespace_write_helper;
737                 } else if (end_io_wq->metadata == BTRFS_WQ_ENDIO_RAID56) {
738                         wq = fs_info->endio_raid56_workers;
739                         func = btrfs_endio_raid56_helper;
740                 } else {
741                         wq = fs_info->endio_write_workers;
742                         func = btrfs_endio_write_helper;
743                 }
744         } else {
745                 if (unlikely(end_io_wq->metadata ==
746                              BTRFS_WQ_ENDIO_DIO_REPAIR)) {
747                         wq = fs_info->endio_repair_workers;
748                         func = btrfs_endio_repair_helper;
749                 } else if (end_io_wq->metadata == BTRFS_WQ_ENDIO_RAID56) {
750                         wq = fs_info->endio_raid56_workers;
751                         func = btrfs_endio_raid56_helper;
752                 } else if (end_io_wq->metadata) {
753                         wq = fs_info->endio_meta_workers;
754                         func = btrfs_endio_meta_helper;
755                 } else {
756                         wq = fs_info->endio_workers;
757                         func = btrfs_endio_helper;
758                 }
759         }
760 
761         btrfs_init_work(&end_io_wq->work, func, end_workqueue_fn, NULL, NULL);
762         btrfs_queue_work(wq, &end_io_wq->work);
763 }
764 
765 int btrfs_bio_wq_end_io(struct btrfs_fs_info *info, struct bio *bio,
766                         enum btrfs_wq_endio_type metadata)
767 {
768         struct btrfs_end_io_wq *end_io_wq;
769 
770         end_io_wq = kmem_cache_alloc(btrfs_end_io_wq_cache, GFP_NOFS);
771         if (!end_io_wq)
772                 return -ENOMEM;
773 
774         end_io_wq->private = bio->bi_private;
775         end_io_wq->end_io = bio->bi_end_io;
776         end_io_wq->info = info;
777         end_io_wq->error = 0;
778         end_io_wq->bio = bio;
779         end_io_wq->metadata = metadata;
780 
781         bio->bi_private = end_io_wq;
782         bio->bi_end_io = end_workqueue_bio;
783         return 0;
784 }
785 
786 unsigned long btrfs_async_submit_limit(struct btrfs_fs_info *info)
787 {
788         unsigned long limit = min_t(unsigned long,
789                                     info->thread_pool_size,
790                                     info->fs_devices->open_devices);
791         return 256 * limit;
792 }
793 
794 static void run_one_async_start(struct btrfs_work *work)
795 {
796         struct async_submit_bio *async;
797         int ret;
798 
799         async = container_of(work, struct  async_submit_bio, work);
800         ret = async->submit_bio_start(async->inode, async->rw, async->bio,
801                                       async->mirror_num, async->bio_flags,
802                                       async->bio_offset);
803         if (ret)
804                 async->error = ret;
805 }
806 
807 static void run_one_async_done(struct btrfs_work *work)
808 {
809         struct btrfs_fs_info *fs_info;
810         struct async_submit_bio *async;
811         int limit;
812 
813         async = container_of(work, struct  async_submit_bio, work);
814         fs_info = BTRFS_I(async->inode)->root->fs_info;
815 
816         limit = btrfs_async_submit_limit(fs_info);
817         limit = limit * 2 / 3;
818 
819         /*
820          * atomic_dec_return implies a barrier for waitqueue_active
821          */
822         if (atomic_dec_return(&fs_info->nr_async_submits) < limit &&
823             waitqueue_active(&fs_info->async_submit_wait))
824                 wake_up(&fs_info->async_submit_wait);
825 
826         /* If an error occurred we just want to clean up the bio and move on */
827         if (async->error) {
828                 async->bio->bi_error = async->error;
829                 bio_endio(async->bio);
830                 return;
831         }
832 
833         async->submit_bio_done(async->inode, async->rw, async->bio,
834                                async->mirror_num, async->bio_flags,
835                                async->bio_offset);
836 }
837 
838 static void run_one_async_free(struct btrfs_work *work)
839 {
840         struct async_submit_bio *async;
841 
842         async = container_of(work, struct  async_submit_bio, work);
843         kfree(async);
844 }
845 
846 int btrfs_wq_submit_bio(struct btrfs_fs_info *fs_info, struct inode *inode,
847                         int rw, struct bio *bio, int mirror_num,
848                         unsigned long bio_flags,
849                         u64 bio_offset,
850                         extent_submit_bio_hook_t *submit_bio_start,
851                         extent_submit_bio_hook_t *submit_bio_done)
852 {
853         struct async_submit_bio *async;
854 
855         async = kmalloc(sizeof(*async), GFP_NOFS);
856         if (!async)
857                 return -ENOMEM;
858 
859         async->inode = inode;
860         async->rw = rw;
861         async->bio = bio;
862         async->mirror_num = mirror_num;
863         async->submit_bio_start = submit_bio_start;
864         async->submit_bio_done = submit_bio_done;
865 
866         btrfs_init_work(&async->work, btrfs_worker_helper, run_one_async_start,
867                         run_one_async_done, run_one_async_free);
868 
869         async->bio_flags = bio_flags;
870         async->bio_offset = bio_offset;
871 
872         async->error = 0;
873 
874         atomic_inc(&fs_info->nr_async_submits);
875 
876         if (rw & REQ_SYNC)
877                 btrfs_set_work_high_priority(&async->work);
878 
879         btrfs_queue_work(fs_info->workers, &async->work);
880 
881         while (atomic_read(&fs_info->async_submit_draining) &&
882               atomic_read(&fs_info->nr_async_submits)) {
883                 wait_event(fs_info->async_submit_wait,
884                            (atomic_read(&fs_info->nr_async_submits) == 0));
885         }
886 
887         return 0;
888 }
889 
890 static int btree_csum_one_bio(struct bio *bio)
891 {
892         struct bio_vec *bvec;
893         struct btrfs_root *root;
894         int i, ret = 0;
895 
896         bio_for_each_segment_all(bvec, bio, i) {
897                 root = BTRFS_I(bvec->bv_page->mapping->host)->root;
898                 ret = csum_dirty_buffer(root->fs_info, bvec->bv_page);
899                 if (ret)
900                         break;
901         }
902 
903         return ret;
904 }
905 
906 static int __btree_submit_bio_start(struct inode *inode, int rw,
907                                     struct bio *bio, int mirror_num,
908                                     unsigned long bio_flags,
909                                     u64 bio_offset)
910 {
911         /*
912          * when we're called for a write, we're already in the async
913          * submission context.  Just jump into btrfs_map_bio
914          */
915         return btree_csum_one_bio(bio);
916 }
917 
918 static int __btree_submit_bio_done(struct inode *inode, int rw, struct bio *bio,
919                                  int mirror_num, unsigned long bio_flags,
920                                  u64 bio_offset)
921 {
922         int ret;
923 
924         /*
925          * when we're called for a write, we're already in the async
926          * submission context.  Just jump into btrfs_map_bio
927          */
928         ret = btrfs_map_bio(BTRFS_I(inode)->root, rw, bio, mirror_num, 1);
929         if (ret) {
930                 bio->bi_error = ret;
931                 bio_endio(bio);
932         }
933         return ret;
934 }
935 
936 static int check_async_write(struct inode *inode, unsigned long bio_flags)
937 {
938         if (bio_flags & EXTENT_BIO_TREE_LOG)
939                 return 0;
940 #ifdef CONFIG_X86
941         if (static_cpu_has(X86_FEATURE_XMM4_2))
942                 return 0;
943 #endif
944         return 1;
945 }
946 
947 static int btree_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
948                                  int mirror_num, unsigned long bio_flags,
949                                  u64 bio_offset)
950 {
951         int async = check_async_write(inode, bio_flags);
952         int ret;
953 
954         if (!(rw & REQ_WRITE)) {
955                 /*
956                  * called for a read, do the setup so that checksum validation
957                  * can happen in the async kernel threads
958                  */
959                 ret = btrfs_bio_wq_end_io(BTRFS_I(inode)->root->fs_info,
960                                           bio, BTRFS_WQ_ENDIO_METADATA);
961                 if (ret)
962                         goto out_w_error;
963                 ret = btrfs_map_bio(BTRFS_I(inode)->root, rw, bio,
964                                     mirror_num, 0);
965         } else if (!async) {
966                 ret = btree_csum_one_bio(bio);
967                 if (ret)
968                         goto out_w_error;
969                 ret = btrfs_map_bio(BTRFS_I(inode)->root, rw, bio,
970                                     mirror_num, 0);
971         } else {
972                 /*
973                  * kthread helpers are used to submit writes so that
974                  * checksumming can happen in parallel across all CPUs
975                  */
976                 ret = btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
977                                           inode, rw, bio, mirror_num, 0,
978                                           bio_offset,
979                                           __btree_submit_bio_start,
980                                           __btree_submit_bio_done);
981         }
982 
983         if (ret)
984                 goto out_w_error;
985         return 0;
986 
987 out_w_error:
988         bio->bi_error = ret;
989         bio_endio(bio);
990         return ret;
991 }
992 
993 #ifdef CONFIG_MIGRATION
994 static int btree_migratepage(struct address_space *mapping,
995                         struct page *newpage, struct page *page,
996                         enum migrate_mode mode)
997 {
998         /*
999          * we can't safely write a btree page from here,
1000          * we haven't done the locking hook
1001          */
1002         if (PageDirty(page))
1003                 return -EAGAIN;
1004         /*
1005          * Buffers may be managed in a filesystem specific way.
1006          * We must have no buffers or drop them.
1007          */
1008         if (page_has_private(page) &&
1009             !try_to_release_page(page, GFP_KERNEL))
1010                 return -EAGAIN;
1011         return migrate_page(mapping, newpage, page, mode);
1012 }
1013 #endif
1014 
1015 
1016 static int btree_writepages(struct address_space *mapping,
1017                             struct writeback_control *wbc)
1018 {
1019         struct btrfs_fs_info *fs_info;
1020         int ret;
1021 
1022         if (wbc->sync_mode == WB_SYNC_NONE) {
1023 
1024                 if (wbc->for_kupdate)
1025                         return 0;
1026 
1027                 fs_info = BTRFS_I(mapping->host)->root->fs_info;
1028                 /* this is a bit racy, but that's ok */
1029                 ret = percpu_counter_compare(&fs_info->dirty_metadata_bytes,
1030                                              BTRFS_DIRTY_METADATA_THRESH);
1031                 if (ret < 0)
1032                         return 0;
1033         }
1034         return btree_write_cache_pages(mapping, wbc);
1035 }
1036 
1037 static int btree_readpage(struct file *file, struct page *page)
1038 {
1039         struct extent_io_tree *tree;
1040         tree = &BTRFS_I(page->mapping->host)->io_tree;
1041         return extent_read_full_page(tree, page, btree_get_extent, 0);
1042 }
1043 
1044 static int btree_releasepage(struct page *page, gfp_t gfp_flags)
1045 {
1046         if (PageWriteback(page) || PageDirty(page))
1047                 return 0;
1048 
1049         return try_release_extent_buffer(page);
1050 }
1051 
1052 static void btree_invalidatepage(struct page *page, unsigned int offset,
1053                                  unsigned int length)
1054 {
1055         struct extent_io_tree *tree;
1056         tree = &BTRFS_I(page->mapping->host)->io_tree;
1057         extent_invalidatepage(tree, page, offset);
1058         btree_releasepage(page, GFP_NOFS);
1059         if (PagePrivate(page)) {
1060                 btrfs_warn(BTRFS_I(page->mapping->host)->root->fs_info,
1061                            "page private not zero on page %llu",
1062                            (unsigned long long)page_offset(page));
1063                 ClearPagePrivate(page);
1064                 set_page_private(page, 0);
1065                 put_page(page);
1066         }
1067 }
1068 
1069 static int btree_set_page_dirty(struct page *page)
1070 {
1071 #ifdef DEBUG
1072         struct extent_buffer *eb;
1073 
1074         BUG_ON(!PagePrivate(page));
1075         eb = (struct extent_buffer *)page->private;
1076         BUG_ON(!eb);
1077         BUG_ON(!test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags));
1078         BUG_ON(!atomic_read(&eb->refs));
1079         btrfs_assert_tree_locked(eb);
1080 #endif
1081         return __set_page_dirty_nobuffers(page);
1082 }
1083 
1084 static const struct address_space_operations btree_aops = {
1085         .readpage       = btree_readpage,
1086         .writepages     = btree_writepages,
1087         .releasepage    = btree_releasepage,
1088         .invalidatepage = btree_invalidatepage,
1089 #ifdef CONFIG_MIGRATION
1090         .migratepage    = btree_migratepage,
1091 #endif
1092         .set_page_dirty = btree_set_page_dirty,
1093 };
1094 
1095 void readahead_tree_block(struct btrfs_root *root, u64 bytenr)
1096 {
1097         struct extent_buffer *buf = NULL;
1098         struct inode *btree_inode = root->fs_info->btree_inode;
1099 
1100         buf = btrfs_find_create_tree_block(root, bytenr);
1101         if (!buf)
1102                 return;
1103         read_extent_buffer_pages(&BTRFS_I(btree_inode)->io_tree,
1104                                  buf, 0, WAIT_NONE, btree_get_extent, 0);
1105         free_extent_buffer(buf);
1106 }
1107 
1108 int reada_tree_block_flagged(struct btrfs_root *root, u64 bytenr,
1109                          int mirror_num, struct extent_buffer **eb)
1110 {
1111         struct extent_buffer *buf = NULL;
1112         struct inode *btree_inode = root->fs_info->btree_inode;
1113         struct extent_io_tree *io_tree = &BTRFS_I(btree_inode)->io_tree;
1114         int ret;
1115 
1116         buf = btrfs_find_create_tree_block(root, bytenr);
1117         if (!buf)
1118                 return 0;
1119 
1120         set_bit(EXTENT_BUFFER_READAHEAD, &buf->bflags);
1121 
1122         ret = read_extent_buffer_pages(io_tree, buf, 0, WAIT_PAGE_LOCK,
1123                                        btree_get_extent, mirror_num);
1124         if (ret) {
1125                 free_extent_buffer(buf);
1126                 return ret;
1127         }
1128 
1129         if (test_bit(EXTENT_BUFFER_CORRUPT, &buf->bflags)) {
1130                 free_extent_buffer(buf);
1131                 return -EIO;
1132         } else if (extent_buffer_uptodate(buf)) {
1133                 *eb = buf;
1134         } else {
1135                 free_extent_buffer(buf);
1136         }
1137         return 0;
1138 }
1139 
1140 struct extent_buffer *btrfs_find_tree_block(struct btrfs_fs_info *fs_info,
1141                                             u64 bytenr)
1142 {
1143         return find_extent_buffer(fs_info, bytenr);
1144 }
1145 
1146 struct extent_buffer *btrfs_find_create_tree_block(struct btrfs_root *root,
1147                                                  u64 bytenr)
1148 {
1149         if (btrfs_test_is_dummy_root(root))
1150                 return alloc_test_extent_buffer(root->fs_info, bytenr);
1151         return alloc_extent_buffer(root->fs_info, bytenr);
1152 }
1153 
1154 
1155 int btrfs_write_tree_block(struct extent_buffer *buf)
1156 {
1157         return filemap_fdatawrite_range(buf->pages[0]->mapping, buf->start,
1158                                         buf->start + buf->len - 1);
1159 }
1160 
1161 int btrfs_wait_tree_block_writeback(struct extent_buffer *buf)
1162 {
1163         return filemap_fdatawait_range(buf->pages[0]->mapping,
1164                                        buf->start, buf->start + buf->len - 1);
1165 }
1166 
1167 struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr,
1168                                       u64 parent_transid)
1169 {
1170         struct extent_buffer *buf = NULL;
1171         int ret;
1172 
1173         buf = btrfs_find_create_tree_block(root, bytenr);
1174         if (!buf)
1175                 return ERR_PTR(-ENOMEM);
1176 
1177         ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
1178         if (ret) {
1179                 free_extent_buffer(buf);
1180                 return ERR_PTR(ret);
1181         }
1182         return buf;
1183 
1184 }
1185 
1186 void clean_tree_block(struct btrfs_trans_handle *trans,
1187                       struct btrfs_fs_info *fs_info,
1188                       struct extent_buffer *buf)
1189 {
1190         if (btrfs_header_generation(buf) ==
1191             fs_info->running_transaction->transid) {
1192                 btrfs_assert_tree_locked(buf);
1193 
1194                 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &buf->bflags)) {
1195                         __percpu_counter_add(&fs_info->dirty_metadata_bytes,
1196                                              -buf->len,
1197                                              fs_info->dirty_metadata_batch);
1198                         /* ugh, clear_extent_buffer_dirty needs to lock the page */
1199                         btrfs_set_lock_blocking(buf);
1200                         clear_extent_buffer_dirty(buf);
1201                 }
1202         }
1203 }
1204 
1205 static struct btrfs_subvolume_writers *btrfs_alloc_subvolume_writers(void)
1206 {
1207         struct btrfs_subvolume_writers *writers;
1208         int ret;
1209 
1210         writers = kmalloc(sizeof(*writers), GFP_NOFS);
1211         if (!writers)
1212                 return ERR_PTR(-ENOMEM);
1213 
1214         ret = percpu_counter_init(&writers->counter, 0, GFP_KERNEL);
1215         if (ret < 0) {
1216                 kfree(writers);
1217                 return ERR_PTR(ret);
1218         }
1219 
1220         init_waitqueue_head(&writers->wait);
1221         return writers;
1222 }
1223 
1224 static void
1225 btrfs_free_subvolume_writers(struct btrfs_subvolume_writers *writers)
1226 {
1227         percpu_counter_destroy(&writers->counter);
1228         kfree(writers);
1229 }
1230 
1231 static void __setup_root(u32 nodesize, u32 sectorsize, u32 stripesize,
1232                          struct btrfs_root *root, struct btrfs_fs_info *fs_info,
1233                          u64 objectid)
1234 {
1235         root->node = NULL;
1236         root->commit_root = NULL;
1237         root->sectorsize = sectorsize;
1238         root->nodesize = nodesize;
1239         root->stripesize = stripesize;
1240         root->state = 0;
1241         root->orphan_cleanup_state = 0;
1242 
1243         root->objectid = objectid;
1244         root->last_trans = 0;
1245         root->highest_objectid = 0;
1246         root->nr_delalloc_inodes = 0;
1247         root->nr_ordered_extents = 0;
1248         root->name = NULL;
1249         root->inode_tree = RB_ROOT;
1250         INIT_RADIX_TREE(&root->delayed_nodes_tree, GFP_ATOMIC);
1251         root->block_rsv = NULL;
1252         root->orphan_block_rsv = NULL;
1253 
1254         INIT_LIST_HEAD(&root->dirty_list);
1255         INIT_LIST_HEAD(&root->root_list);
1256         INIT_LIST_HEAD(&root->delalloc_inodes);
1257         INIT_LIST_HEAD(&root->delalloc_root);
1258         INIT_LIST_HEAD(&root->ordered_extents);
1259         INIT_LIST_HEAD(&root->ordered_root);
1260         INIT_LIST_HEAD(&root->logged_list[0]);
1261         INIT_LIST_HEAD(&root->logged_list[1]);
1262         spin_lock_init(&root->orphan_lock);
1263         spin_lock_init(&root->inode_lock);
1264         spin_lock_init(&root->delalloc_lock);
1265         spin_lock_init(&root->ordered_extent_lock);
1266         spin_lock_init(&root->accounting_lock);
1267         spin_lock_init(&root->log_extents_lock[0]);
1268         spin_lock_init(&root->log_extents_lock[1]);
1269         mutex_init(&root->objectid_mutex);
1270         mutex_init(&root->log_mutex);
1271         mutex_init(&root->ordered_extent_mutex);
1272         mutex_init(&root->delalloc_mutex);
1273         init_waitqueue_head(&root->log_writer_wait);
1274         init_waitqueue_head(&root->log_commit_wait[0]);
1275         init_waitqueue_head(&root->log_commit_wait[1]);
1276         INIT_LIST_HEAD(&root->log_ctxs[0]);
1277         INIT_LIST_HEAD(&root->log_ctxs[1]);
1278         atomic_set(&root->log_commit[0], 0);
1279         atomic_set(&root->log_commit[1], 0);
1280         atomic_set(&root->log_writers, 0);
1281         atomic_set(&root->log_batch, 0);
1282         atomic_set(&root->orphan_inodes, 0);
1283         atomic_set(&root->refs, 1);
1284         atomic_set(&root->will_be_snapshoted, 0);
1285         atomic_set(&root->qgroup_meta_rsv, 0);
1286         root->log_transid = 0;
1287         root->log_transid_committed = -1;
1288         root->last_log_commit = 0;
1289         if (fs_info)
1290                 extent_io_tree_init(&root->dirty_log_pages,
1291                                      fs_info->btree_inode->i_mapping);
1292 
1293         memset(&root->root_key, 0, sizeof(root->root_key));
1294         memset(&root->root_item, 0, sizeof(root->root_item));
1295         memset(&root->defrag_progress, 0, sizeof(root->defrag_progress));
1296         if (fs_info)
1297                 root->defrag_trans_start = fs_info->generation;
1298         else
1299                 root->defrag_trans_start = 0;
1300         root->root_key.objectid = objectid;
1301         root->anon_dev = 0;
1302 
1303         spin_lock_init(&root->root_item_lock);
1304 }
1305 
1306 static struct btrfs_root *btrfs_alloc_root(struct btrfs_fs_info *fs_info,
1307                 gfp_t flags)
1308 {
1309         struct btrfs_root *root = kzalloc(sizeof(*root), flags);
1310         if (root)
1311                 root->fs_info = fs_info;
1312         return root;
1313 }
1314 
1315 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
1316 /* Should only be used by the testing infrastructure */
1317 struct btrfs_root *btrfs_alloc_dummy_root(void)
1318 {
1319         struct btrfs_root *root;
1320 
1321         root = btrfs_alloc_root(NULL, GFP_KERNEL);
1322         if (!root)
1323                 return ERR_PTR(-ENOMEM);
1324         __setup_root(4096, 4096, 4096, root, NULL, 1);
1325         set_bit(BTRFS_ROOT_DUMMY_ROOT, &root->state);
1326         root->alloc_bytenr = 0;
1327 
1328         return root;
1329 }
1330 #endif
1331 
1332 struct btrfs_root *btrfs_create_tree(struct btrfs_trans_handle *trans,
1333                                      struct btrfs_fs_info *fs_info,
1334                                      u64 objectid)
1335 {
1336         struct extent_buffer *leaf;
1337         struct btrfs_root *tree_root = fs_info->tree_root;
1338         struct btrfs_root *root;
1339         struct btrfs_key key;
1340         int ret = 0;
1341         uuid_le uuid;
1342 
1343         root = btrfs_alloc_root(fs_info, GFP_KERNEL);
1344         if (!root)
1345                 return ERR_PTR(-ENOMEM);
1346 
1347         __setup_root(tree_root->nodesize, tree_root->sectorsize,
1348                 tree_root->stripesize, root, fs_info, objectid);
1349         root->root_key.objectid = objectid;
1350         root->root_key.type = BTRFS_ROOT_ITEM_KEY;
1351         root->root_key.offset = 0;
1352 
1353         leaf = btrfs_alloc_tree_block(trans, root, 0, objectid, NULL, 0, 0, 0);
1354         if (IS_ERR(leaf)) {
1355                 ret = PTR_ERR(leaf);
1356                 leaf = NULL;
1357                 goto fail;
1358         }
1359 
1360         memset_extent_buffer(leaf, 0, 0, sizeof(struct btrfs_header));
1361         btrfs_set_header_bytenr(leaf, leaf->start);
1362         btrfs_set_header_generation(leaf, trans->transid);
1363         btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV);
1364         btrfs_set_header_owner(leaf, objectid);
1365         root->node = leaf;
1366 
1367         write_extent_buffer(leaf, fs_info->fsid, btrfs_header_fsid(),
1368                             BTRFS_FSID_SIZE);
1369         write_extent_buffer(leaf, fs_info->chunk_tree_uuid,
1370                             btrfs_header_chunk_tree_uuid(leaf),
1371                             BTRFS_UUID_SIZE);
1372         btrfs_mark_buffer_dirty(leaf);
1373 
1374         root->commit_root = btrfs_root_node(root);
1375         set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
1376 
1377         root->root_item.flags = 0;
1378         root->root_item.byte_limit = 0;
1379         btrfs_set_root_bytenr(&root->root_item, leaf->start);
1380         btrfs_set_root_generation(&root->root_item, trans->transid);
1381         btrfs_set_root_level(&root->root_item, 0);
1382         btrfs_set_root_refs(&root->root_item, 1);
1383         btrfs_set_root_used(&root->root_item, leaf->len);
1384         btrfs_set_root_last_snapshot(&root->root_item, 0);
1385         btrfs_set_root_dirid(&root->root_item, 0);
1386         uuid_le_gen(&uuid);
1387         memcpy(root->root_item.uuid, uuid.b, BTRFS_UUID_SIZE);
1388         root->root_item.drop_level = 0;
1389 
1390         key.objectid = objectid;
1391         key.type = BTRFS_ROOT_ITEM_KEY;
1392         key.offset = 0;
1393         ret = btrfs_insert_root(trans, tree_root, &key, &root->root_item);
1394         if (ret)
1395                 goto fail;
1396 
1397         btrfs_tree_unlock(leaf);
1398 
1399         return root;
1400 
1401 fail:
1402         if (leaf) {
1403                 btrfs_tree_unlock(leaf);
1404                 free_extent_buffer(root->commit_root);
1405                 free_extent_buffer(leaf);
1406         }
1407         kfree(root);
1408 
1409         return ERR_PTR(ret);
1410 }
1411 
1412 static struct btrfs_root *alloc_log_tree(struct btrfs_trans_handle *trans,
1413                                          struct btrfs_fs_info *fs_info)
1414 {
1415         struct btrfs_root *root;
1416         struct btrfs_root *tree_root = fs_info->tree_root;
1417         struct extent_buffer *leaf;
1418 
1419         root = btrfs_alloc_root(fs_info, GFP_NOFS);
1420         if (!root)
1421                 return ERR_PTR(-ENOMEM);
1422 
1423         __setup_root(tree_root->nodesize, tree_root->sectorsize,
1424                      tree_root->stripesize, root, fs_info,
1425                      BTRFS_TREE_LOG_OBJECTID);
1426 
1427         root->root_key.objectid = BTRFS_TREE_LOG_OBJECTID;
1428         root->root_key.type = BTRFS_ROOT_ITEM_KEY;
1429         root->root_key.offset = BTRFS_TREE_LOG_OBJECTID;
1430 
1431         /*
1432          * DON'T set REF_COWS for log trees
1433          *
1434          * log trees do not get reference counted because they go away
1435          * before a real commit is actually done.  They do store pointers
1436          * to file data extents, and those reference counts still get
1437          * updated (along with back refs to the log tree).
1438          */
1439 
1440         leaf = btrfs_alloc_tree_block(trans, root, 0, BTRFS_TREE_LOG_OBJECTID,
1441                         NULL, 0, 0, 0);
1442         if (IS_ERR(leaf)) {
1443                 kfree(root);
1444                 return ERR_CAST(leaf);
1445         }
1446 
1447         memset_extent_buffer(leaf, 0, 0, sizeof(struct btrfs_header));
1448         btrfs_set_header_bytenr(leaf, leaf->start);
1449         btrfs_set_header_generation(leaf, trans->transid);
1450         btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV);
1451         btrfs_set_header_owner(leaf, BTRFS_TREE_LOG_OBJECTID);
1452         root->node = leaf;
1453 
1454         write_extent_buffer(root->node, root->fs_info->fsid,
1455                             btrfs_header_fsid(), BTRFS_FSID_SIZE);
1456         btrfs_mark_buffer_dirty(root->node);
1457         btrfs_tree_unlock(root->node);
1458         return root;
1459 }
1460 
1461 int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
1462                              struct btrfs_fs_info *fs_info)
1463 {
1464         struct btrfs_root *log_root;
1465 
1466         log_root = alloc_log_tree(trans, fs_info);
1467         if (IS_ERR(log_root))
1468                 return PTR_ERR(log_root);
1469         WARN_ON(fs_info->log_root_tree);
1470         fs_info->log_root_tree = log_root;
1471         return 0;
1472 }
1473 
1474 int btrfs_add_log_tree(struct btrfs_trans_handle *trans,
1475                        struct btrfs_root *root)
1476 {
1477         struct btrfs_root *log_root;
1478         struct btrfs_inode_item *inode_item;
1479 
1480         log_root = alloc_log_tree(trans, root->fs_info);
1481         if (IS_ERR(log_root))
1482                 return PTR_ERR(log_root);
1483 
1484         log_root->last_trans = trans->transid;
1485         log_root->root_key.offset = root->root_key.objectid;
1486 
1487         inode_item = &log_root->root_item.inode;
1488         btrfs_set_stack_inode_generation(inode_item, 1);
1489         btrfs_set_stack_inode_size(inode_item, 3);
1490         btrfs_set_stack_inode_nlink(inode_item, 1);
1491         btrfs_set_stack_inode_nbytes(inode_item, root->nodesize);
1492         btrfs_set_stack_inode_mode(inode_item, S_IFDIR | 0755);
1493 
1494         btrfs_set_root_node(&log_root->root_item, log_root->node);
1495 
1496         WARN_ON(root->log_root);
1497         root->log_root = log_root;
1498         root->log_transid = 0;
1499         root->log_transid_committed = -1;
1500         root->last_log_commit = 0;
1501         return 0;
1502 }
1503 
1504 static struct btrfs_root *btrfs_read_tree_root(struct btrfs_root *tree_root,
1505                                                struct btrfs_key *key)
1506 {
1507         struct btrfs_root *root;
1508         struct btrfs_fs_info *fs_info = tree_root->fs_info;
1509         struct btrfs_path *path;
1510         u64 generation;
1511         int ret;
1512 
1513         path = btrfs_alloc_path();
1514         if (!path)
1515                 return ERR_PTR(-ENOMEM);
1516 
1517         root = btrfs_alloc_root(fs_info, GFP_NOFS);
1518         if (!root) {
1519                 ret = -ENOMEM;
1520                 goto alloc_fail;
1521         }
1522 
1523         __setup_root(tree_root->nodesize, tree_root->sectorsize,
1524                 tree_root->stripesize, root, fs_info, key->objectid);
1525 
1526         ret = btrfs_find_root(tree_root, key, path,
1527                               &root->root_item, &root->root_key);
1528         if (ret) {
1529                 if (ret > 0)
1530                         ret = -ENOENT;
1531                 goto find_fail;
1532         }
1533 
1534         generation = btrfs_root_generation(&root->root_item);
1535         root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
1536                                      generation);
1537         if (IS_ERR(root->node)) {
1538                 ret = PTR_ERR(root->node);
1539                 goto find_fail;
1540         } else if (!btrfs_buffer_uptodate(root->node, generation, 0)) {
1541                 ret = -EIO;
1542                 free_extent_buffer(root->node);
1543                 goto find_fail;
1544         }
1545         root->commit_root = btrfs_root_node(root);
1546 out:
1547         btrfs_free_path(path);
1548         return root;
1549 
1550 find_fail:
1551         kfree(root);
1552 alloc_fail:
1553         root = ERR_PTR(ret);
1554         goto out;
1555 }
1556 
1557 struct btrfs_root *btrfs_read_fs_root(struct btrfs_root *tree_root,
1558                                       struct btrfs_key *location)
1559 {
1560         struct btrfs_root *root;
1561 
1562         root = btrfs_read_tree_root(tree_root, location);
1563         if (IS_ERR(root))
1564                 return root;
1565 
1566         if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) {
1567                 set_bit(BTRFS_ROOT_REF_COWS, &root->state);
1568                 btrfs_check_and_init_root_item(&root->root_item);
1569         }
1570 
1571         return root;
1572 }
1573 
1574 int btrfs_init_fs_root(struct btrfs_root *root)
1575 {
1576         int ret;
1577         struct btrfs_subvolume_writers *writers;
1578 
1579         root->free_ino_ctl = kzalloc(sizeof(*root->free_ino_ctl), GFP_NOFS);
1580         root->free_ino_pinned = kzalloc(sizeof(*root->free_ino_pinned),
1581                                         GFP_NOFS);
1582         if (!root->free_ino_pinned || !root->free_ino_ctl) {
1583                 ret = -ENOMEM;
1584                 goto fail;
1585         }
1586 
1587         writers = btrfs_alloc_subvolume_writers();
1588         if (IS_ERR(writers)) {
1589                 ret = PTR_ERR(writers);
1590                 goto fail;
1591         }
1592         root->subv_writers = writers;
1593 
1594         btrfs_init_free_ino_ctl(root);
1595         spin_lock_init(&root->ino_cache_lock);
1596         init_waitqueue_head(&root->ino_cache_wait);
1597 
1598         ret = get_anon_bdev(&root->anon_dev);
1599         if (ret)
1600                 goto free_writers;
1601 
1602         mutex_lock(&root->objectid_mutex);
1603         ret = btrfs_find_highest_objectid(root,
1604                                         &root->highest_objectid);
1605         if (ret) {
1606                 mutex_unlock(&root->objectid_mutex);
1607                 goto free_root_dev;
1608         }
1609 
1610         ASSERT(root->highest_objectid <= BTRFS_LAST_FREE_OBJECTID);
1611 
1612         mutex_unlock(&root->objectid_mutex);
1613 
1614         return 0;
1615 
1616 free_root_dev:
1617         free_anon_bdev(root->anon_dev);
1618 free_writers:
1619         btrfs_free_subvolume_writers(root->subv_writers);
1620 fail:
1621         kfree(root->free_ino_ctl);
1622         kfree(root->free_ino_pinned);
1623         return ret;
1624 }
1625 
1626 static struct btrfs_root *btrfs_lookup_fs_root(struct btrfs_fs_info *fs_info,
1627                                                u64 root_id)
1628 {
1629         struct btrfs_root *root;
1630 
1631         spin_lock(&fs_info->fs_roots_radix_lock);
1632         root = radix_tree_lookup(&fs_info->fs_roots_radix,
1633                                  (unsigned long)root_id);
1634         spin_unlock(&fs_info->fs_roots_radix_lock);
1635         return root;
1636 }
1637 
1638 int btrfs_insert_fs_root(struct btrfs_fs_info *fs_info,
1639                          struct btrfs_root *root)
1640 {
1641         int ret;
1642 
1643         ret = radix_tree_preload(GFP_NOFS & ~__GFP_HIGHMEM);
1644         if (ret)
1645                 return ret;
1646 
1647         spin_lock(&fs_info->fs_roots_radix_lock);
1648         ret = radix_tree_insert(&fs_info->fs_roots_radix,
1649                                 (unsigned long)root->root_key.objectid,
1650                                 root);
1651         if (ret == 0)
1652                 set_bit(BTRFS_ROOT_IN_RADIX, &root->state);
1653         spin_unlock(&fs_info->fs_roots_radix_lock);
1654         radix_tree_preload_end();
1655 
1656         return ret;
1657 }
1658 
1659 struct btrfs_root *btrfs_get_fs_root(struct btrfs_fs_info *fs_info,
1660                                      struct btrfs_key *location,
1661                                      bool check_ref)
1662 {
1663         struct btrfs_root *root;
1664         struct btrfs_path *path;
1665         struct btrfs_key key;
1666         int ret;
1667 
1668         if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
1669                 return fs_info->tree_root;
1670         if (location->objectid == BTRFS_EXTENT_TREE_OBJECTID)
1671                 return fs_info->extent_root;
1672         if (location->objectid == BTRFS_CHUNK_TREE_OBJECTID)
1673                 return fs_info->chunk_root;
1674         if (location->objectid == BTRFS_DEV_TREE_OBJECTID)
1675                 return fs_info->dev_root;
1676         if (location->objectid == BTRFS_CSUM_TREE_OBJECTID)
1677                 return fs_info->csum_root;
1678         if (location->objectid == BTRFS_QUOTA_TREE_OBJECTID)
1679                 return fs_info->quota_root ? fs_info->quota_root :
1680                                              ERR_PTR(-ENOENT);
1681         if (location->objectid == BTRFS_UUID_TREE_OBJECTID)
1682                 return fs_info->uuid_root ? fs_info->uuid_root :
1683                                             ERR_PTR(-ENOENT);
1684         if (location->objectid == BTRFS_FREE_SPACE_TREE_OBJECTID)
1685                 return fs_info->free_space_root ? fs_info->free_space_root :
1686                                                   ERR_PTR(-ENOENT);
1687 again:
1688         root = btrfs_lookup_fs_root(fs_info, location->objectid);
1689         if (root) {
1690                 if (check_ref && btrfs_root_refs(&root->root_item) == 0)
1691                         return ERR_PTR(-ENOENT);
1692                 return root;
1693         }
1694 
1695         root = btrfs_read_fs_root(fs_info->tree_root, location);
1696         if (IS_ERR(root))
1697                 return root;
1698 
1699         if (check_ref && btrfs_root_refs(&root->root_item) == 0) {
1700                 ret = -ENOENT;
1701                 goto fail;
1702         }
1703 
1704         ret = btrfs_init_fs_root(root);
1705         if (ret)
1706                 goto fail;
1707 
1708         path = btrfs_alloc_path();
1709         if (!path) {
1710                 ret = -ENOMEM;
1711                 goto fail;
1712         }
1713         key.objectid = BTRFS_ORPHAN_OBJECTID;
1714         key.type = BTRFS_ORPHAN_ITEM_KEY;
1715         key.offset = location->objectid;
1716 
1717         ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
1718         btrfs_free_path(path);
1719         if (ret < 0)
1720                 goto fail;
1721         if (ret == 0)
1722                 set_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state);
1723 
1724         ret = btrfs_insert_fs_root(fs_info, root);
1725         if (ret) {
1726                 if (ret == -EEXIST) {
1727                         free_fs_root(root);
1728                         goto again;
1729                 }
1730                 goto fail;
1731         }
1732         return root;
1733 fail:
1734         free_fs_root(root);
1735         return ERR_PTR(ret);
1736 }
1737 
1738 static int btrfs_congested_fn(void *congested_data, int bdi_bits)
1739 {
1740         struct btrfs_fs_info *info = (struct btrfs_fs_info *)congested_data;
1741         int ret = 0;
1742         struct btrfs_device *device;
1743         struct backing_dev_info *bdi;
1744 
1745         rcu_read_lock();
1746         list_for_each_entry_rcu(device, &info->fs_devices->devices, dev_list) {
1747                 if (!device->bdev)
1748                         continue;
1749                 bdi = blk_get_backing_dev_info(device->bdev);
1750                 if (bdi_congested(bdi, bdi_bits)) {
1751                         ret = 1;
1752                         break;
1753                 }
1754         }
1755         rcu_read_unlock();
1756         return ret;
1757 }
1758 
1759 static int setup_bdi(struct btrfs_fs_info *info, struct backing_dev_info *bdi)
1760 {
1761         int err;
1762 
1763         err = bdi_setup_and_register(bdi, "btrfs");
1764         if (err)
1765                 return err;
1766 
1767         bdi->ra_pages = VM_MAX_READAHEAD * 1024 / PAGE_SIZE;
1768         bdi->congested_fn       = btrfs_congested_fn;
1769         bdi->congested_data     = info;
1770         bdi->capabilities |= BDI_CAP_CGROUP_WRITEBACK;
1771         return 0;
1772 }
1773 
1774 /*
1775  * called by the kthread helper functions to finally call the bio end_io
1776  * functions.  This is where read checksum verification actually happens
1777  */
1778 static void end_workqueue_fn(struct btrfs_work *work)
1779 {
1780         struct bio *bio;
1781         struct btrfs_end_io_wq *end_io_wq;
1782 
1783         end_io_wq = container_of(work, struct btrfs_end_io_wq, work);
1784         bio = end_io_wq->bio;
1785 
1786         bio->bi_error = end_io_wq->error;
1787         bio->bi_private = end_io_wq->private;
1788         bio->bi_end_io = end_io_wq->end_io;
1789         kmem_cache_free(btrfs_end_io_wq_cache, end_io_wq);
1790         bio_endio(bio);
1791 }
1792 
1793 static int cleaner_kthread(void *arg)
1794 {
1795         struct btrfs_root *root = arg;
1796         int again;
1797         struct btrfs_trans_handle *trans;
1798 
1799         do {
1800                 again = 0;
1801 
1802                 /* Make the cleaner go to sleep early. */
1803                 if (btrfs_need_cleaner_sleep(root))
1804                         goto sleep;
1805 
1806                 if (!mutex_trylock(&root->fs_info->cleaner_mutex))
1807                         goto sleep;
1808 
1809                 /*
1810                  * Avoid the problem that we change the status of the fs
1811                  * during the above check and trylock.
1812                  */
1813                 if (btrfs_need_cleaner_sleep(root)) {
1814                         mutex_unlock(&root->fs_info->cleaner_mutex);
1815                         goto sleep;
1816                 }
1817 
1818                 mutex_lock(&root->fs_info->cleaner_delayed_iput_mutex);
1819                 btrfs_run_delayed_iputs(root);
1820                 mutex_unlock(&root->fs_info->cleaner_delayed_iput_mutex);
1821 
1822                 again = btrfs_clean_one_deleted_snapshot(root);
1823                 mutex_unlock(&root->fs_info->cleaner_mutex);
1824 
1825                 /*
1826                  * The defragger has dealt with the R/O remount and umount,
1827                  * needn't do anything special here.
1828                  */
1829                 btrfs_run_defrag_inodes(root->fs_info);
1830 
1831                 /*
1832                  * Acquires fs_info->delete_unused_bgs_mutex to avoid racing
1833                  * with relocation (btrfs_relocate_chunk) and relocation
1834                  * acquires fs_info->cleaner_mutex (btrfs_relocate_block_group)
1835                  * after acquiring fs_info->delete_unused_bgs_mutex. So we
1836                  * can't hold, nor need to, fs_info->cleaner_mutex when deleting
1837                  * unused block groups.
1838                  */
1839                 btrfs_delete_unused_bgs(root->fs_info);
1840 sleep:
1841                 if (!again) {
1842                         set_current_state(TASK_INTERRUPTIBLE);
1843                         if (!kthread_should_stop())
1844                                 schedule();
1845                         __set_current_state(TASK_RUNNING);
1846                 }
1847         } while (!kthread_should_stop());
1848 
1849         /*
1850          * Transaction kthread is stopped before us and wakes us up.
1851          * However we might have started a new transaction and COWed some
1852          * tree blocks when deleting unused block groups for example. So
1853          * make sure we commit the transaction we started to have a clean
1854          * shutdown when evicting the btree inode - if it has dirty pages
1855          * when we do the final iput() on it, eviction will trigger a
1856          * writeback for it which will fail with null pointer dereferences
1857          * since work queues and other resources were already released and
1858          * destroyed by the time the iput/eviction/writeback is made.
1859          */
1860         trans = btrfs_attach_transaction(root);
1861         if (IS_ERR(trans)) {
1862                 if (PTR_ERR(trans) != -ENOENT)
1863                         btrfs_err(root->fs_info,
1864                                   "cleaner transaction attach returned %ld",
1865                                   PTR_ERR(trans));
1866         } else {
1867                 int ret;
1868 
1869                 ret = btrfs_commit_transaction(trans, root);
1870                 if (ret)
1871                         btrfs_err(root->fs_info,
1872                                   "cleaner open transaction commit returned %d",
1873                                   ret);
1874         }
1875 
1876         return 0;
1877 }
1878 
1879 static int transaction_kthread(void *arg)
1880 {
1881         struct btrfs_root *root = arg;
1882         struct btrfs_trans_handle *trans;
1883         struct btrfs_transaction *cur;
1884         u64 transid;
1885         unsigned long now;
1886         unsigned long delay;
1887         bool cannot_commit;
1888 
1889         do {
1890                 cannot_commit = false;
1891                 delay = HZ * root->fs_info->commit_interval;
1892                 mutex_lock(&root->fs_info->transaction_kthread_mutex);
1893 
1894                 spin_lock(&root->fs_info->trans_lock);
1895                 cur = root->fs_info->running_transaction;
1896                 if (!cur) {
1897                         spin_unlock(&root->fs_info->trans_lock);
1898                         goto sleep;
1899                 }
1900 
1901                 now = get_seconds();
1902                 if (cur->state < TRANS_STATE_BLOCKED &&
1903                     (now < cur->start_time ||
1904                      now - cur->start_time < root->fs_info->commit_interval)) {
1905                         spin_unlock(&root->fs_info->trans_lock);
1906                         delay = HZ * 5;
1907                         goto sleep;
1908                 }
1909                 transid = cur->transid;
1910                 spin_unlock(&root->fs_info->trans_lock);
1911 
1912                 /* If the file system is aborted, this will always fail. */
1913                 trans = btrfs_attach_transaction(root);
1914                 if (IS_ERR(trans)) {
1915                         if (PTR_ERR(trans) != -ENOENT)
1916                                 cannot_commit = true;
1917                         goto sleep;
1918                 }
1919                 if (transid == trans->transid) {
1920                         btrfs_commit_transaction(trans, root);
1921                 } else {
1922                         btrfs_end_transaction(trans, root);
1923                 }
1924 sleep:
1925                 wake_up_process(root->fs_info->cleaner_kthread);
1926                 mutex_unlock(&root->fs_info->transaction_kthread_mutex);
1927 
1928                 if (unlikely(test_bit(BTRFS_FS_STATE_ERROR,
1929                                       &root->fs_info->fs_state)))
1930                         btrfs_cleanup_transaction(root);
1931                 set_current_state(TASK_INTERRUPTIBLE);
1932                 if (!kthread_should_stop() &&
1933                                 (!btrfs_transaction_blocked(root->fs_info) ||
1934                                  cannot_commit))
1935                         schedule_timeout(delay);
1936                 __set_current_state(TASK_RUNNING);
1937         } while (!kthread_should_stop());
1938         return 0;
1939 }
1940 
1941 /*
1942  * this will find the highest generation in the array of
1943  * root backups.  The index of the highest array is returned,
1944  * or -1 if we can't find anything.
1945  *
1946  * We check to make sure the array is valid by comparing the
1947  * generation of the latest  root in the array with the generation
1948  * in the super block.  If they don't match we pitch it.
1949  */
1950 static int find_newest_super_backup(struct btrfs_fs_info *info, u64 newest_gen)
1951 {
1952         u64 cur;
1953         int newest_index = -1;
1954         struct btrfs_root_backup *root_backup;
1955         int i;
1956 
1957         for (i = 0; i < BTRFS_NUM_BACKUP_ROOTS; i++) {
1958                 root_backup = info->super_copy->super_roots + i;
1959                 cur = btrfs_backup_tree_root_gen(root_backup);
1960                 if (cur == newest_gen)
1961                         newest_index = i;
1962         }
1963 
1964         /* check to see if we actually wrapped around */
1965         if (newest_index == BTRFS_NUM_BACKUP_ROOTS - 1) {
1966                 root_backup = info->super_copy->super_roots;
1967                 cur = btrfs_backup_tree_root_gen(root_backup);
1968                 if (cur == newest_gen)
1969                         newest_index = 0;
1970         }
1971         return newest_index;
1972 }
1973 
1974 
1975 /*
1976  * find the oldest backup so we know where to store new entries
1977  * in the backup array.  This will set the backup_root_index
1978  * field in the fs_info struct
1979  */
1980 static void find_oldest_super_backup(struct btrfs_fs_info *info,
1981                                      u64 newest_gen)
1982 {
1983         int newest_index = -1;
1984 
1985         newest_index = find_newest_super_backup(info, newest_gen);
1986         /* if there was garbage in there, just move along */
1987         if (newest_index == -1) {
1988                 info->backup_root_index = 0;
1989         } else {
1990                 info->backup_root_index = (newest_index + 1) % BTRFS_NUM_BACKUP_ROOTS;
1991         }
1992 }
1993 
1994 /*
1995  * copy all the root pointers into the super backup array.
1996  * this will bump the backup pointer by one when it is
1997  * done
1998  */
1999 static void backup_super_roots(struct btrfs_fs_info *info)
2000 {
2001         int next_backup;
2002         struct btrfs_root_backup *root_backup;
2003         int last_backup;
2004 
2005         next_backup = info->backup_root_index;
2006         last_backup = (next_backup + BTRFS_NUM_BACKUP_ROOTS - 1) %
2007                 BTRFS_NUM_BACKUP_ROOTS;
2008 
2009         /*
2010          * just overwrite the last backup if we're at the same generation
2011          * this happens only at umount
2012          */
2013         root_backup = info->super_for_commit->super_roots + last_backup;
2014         if (btrfs_backup_tree_root_gen(root_backup) ==
2015             btrfs_header_generation(info->tree_root->node))
2016                 next_backup = last_backup;
2017 
2018         root_backup = info->super_for_commit->super_roots + next_backup;
2019 
2020         /*
2021          * make sure all of our padding and empty slots get zero filled
2022          * regardless of which ones we use today
2023          */
2024         memset(root_backup, 0, sizeof(*root_backup));
2025 
2026         info->backup_root_index = (next_backup + 1) % BTRFS_NUM_BACKUP_ROOTS;
2027 
2028         btrfs_set_backup_tree_root(root_backup, info->tree_root->node->start);
2029         btrfs_set_backup_tree_root_gen(root_backup,
2030                                btrfs_header_generation(info->tree_root->node));
2031 
2032         btrfs_set_backup_tree_root_level(root_backup,
2033                                btrfs_header_level(info->tree_root->node));
2034 
2035         btrfs_set_backup_chunk_root(root_backup, info->chunk_root->node->start);
2036         btrfs_set_backup_chunk_root_gen(root_backup,
2037                                btrfs_header_generation(info->chunk_root->node));
2038         btrfs_set_backup_chunk_root_level(root_backup,
2039                                btrfs_header_level(info->chunk_root->node));
2040 
2041         btrfs_set_backup_extent_root(root_backup, info->extent_root->node->start);
2042         btrfs_set_backup_extent_root_gen(root_backup,
2043                                btrfs_header_generation(info->extent_root->node));
2044         btrfs_set_backup_extent_root_level(root_backup,
2045                                btrfs_header_level(info->extent_root->node));
2046 
2047         /*
2048          * we might commit during log recovery, which happens before we set
2049          * the fs_root.  Make sure it is valid before we fill it in.
2050          */
2051         if (info->fs_root && info->fs_root->node) {
2052                 btrfs_set_backup_fs_root(root_backup,
2053                                          info->fs_root->node->start);
2054                 btrfs_set_backup_fs_root_gen(root_backup,
2055                                btrfs_header_generation(info->fs_root->node));
2056                 btrfs_set_backup_fs_root_level(root_backup,
2057                                btrfs_header_level(info->fs_root->node));
2058         }
2059 
2060         btrfs_set_backup_dev_root(root_backup, info->dev_root->node->start);
2061         btrfs_set_backup_dev_root_gen(root_backup,
2062                                btrfs_header_generation(info->dev_root->node));
2063         btrfs_set_backup_dev_root_level(root_backup,
2064                                        btrfs_header_level(info->dev_root->node));
2065 
2066         btrfs_set_backup_csum_root(root_backup, info->csum_root->node->start);
2067         btrfs_set_backup_csum_root_gen(root_backup,
2068                                btrfs_header_generation(info->csum_root->node));
2069         btrfs_set_backup_csum_root_level(root_backup,
2070                                btrfs_header_level(info->csum_root->node));
2071 
2072         btrfs_set_backup_total_bytes(root_backup,
2073                              btrfs_super_total_bytes(info->super_copy));
2074         btrfs_set_backup_bytes_used(root_backup,
2075                              btrfs_super_bytes_used(info->super_copy));
2076         btrfs_set_backup_num_devices(root_backup,
2077                              btrfs_super_num_devices(info->super_copy));
2078 
2079         /*
2080          * if we don't copy this out to the super_copy, it won't get remembered
2081          * for the next commit
2082          */
2083         memcpy(&info->super_copy->super_roots,
2084                &info->super_for_commit->super_roots,
2085                sizeof(*root_backup) * BTRFS_NUM_BACKUP_ROOTS);
2086 }
2087 
2088 /*
2089  * this copies info out of the root backup array and back into
2090  * the in-memory super block.  It is meant to help iterate through
2091  * the array, so you send it the number of backups you've already
2092  * tried and the last backup index you used.
2093  *
2094  * this returns -1 when it has tried all the backups
2095  */
2096 static noinline int next_root_backup(struct btrfs_fs_info *info,
2097                                      struct btrfs_super_block *super,
2098                                      int *num_backups_tried, int *backup_index)
2099 {
2100         struct btrfs_root_backup *root_backup;
2101         int newest = *backup_index;
2102 
2103         if (*num_backups_tried == 0) {
2104                 u64 gen = btrfs_super_generation(super);
2105 
2106                 newest = find_newest_super_backup(info, gen);
2107                 if (newest == -1)
2108                         return -1;
2109 
2110                 *backup_index = newest;
2111                 *num_backups_tried = 1;
2112         } else if (*num_backups_tried == BTRFS_NUM_BACKUP_ROOTS) {
2113                 /* we've tried all the backups, all done */
2114                 return -1;
2115         } else {
2116                 /* jump to the next oldest backup */
2117                 newest = (*backup_index + BTRFS_NUM_BACKUP_ROOTS - 1) %
2118                         BTRFS_NUM_BACKUP_ROOTS;
2119                 *backup_index = newest;
2120                 *num_backups_tried += 1;
2121         }
2122         root_backup = super->super_roots + newest;
2123 
2124         btrfs_set_super_generation(super,
2125                                    btrfs_backup_tree_root_gen(root_backup));
2126         btrfs_set_super_root(super, btrfs_backup_tree_root(root_backup));
2127         btrfs_set_super_root_level(super,
2128                                    btrfs_backup_tree_root_level(root_backup));
2129         btrfs_set_super_bytes_used(super, btrfs_backup_bytes_used(root_backup));
2130 
2131         /*
2132          * fixme: the total bytes and num_devices need to match or we should
2133          * need a fsck
2134          */
2135         btrfs_set_super_total_bytes(super, btrfs_backup_total_bytes(root_backup));
2136         btrfs_set_super_num_devices(super, btrfs_backup_num_devices(root_backup));
2137         return 0;
2138 }
2139 
2140 /* helper to cleanup workers */
2141 static void btrfs_stop_all_workers(struct btrfs_fs_info *fs_info)
2142 {
2143         btrfs_destroy_workqueue(fs_info->fixup_workers);
2144         btrfs_destroy_workqueue(fs_info->delalloc_workers);
2145         btrfs_destroy_workqueue(fs_info->workers);
2146         btrfs_destroy_workqueue(fs_info->endio_workers);
2147         btrfs_destroy_workqueue(fs_info->endio_meta_workers);
2148         btrfs_destroy_workqueue(fs_info->endio_raid56_workers);
2149         btrfs_destroy_workqueue(fs_info->endio_repair_workers);
2150         btrfs_destroy_workqueue(fs_info->rmw_workers);
2151         btrfs_destroy_workqueue(fs_info->endio_meta_write_workers);
2152         btrfs_destroy_workqueue(fs_info->endio_write_workers);
2153         btrfs_destroy_workqueue(fs_info->endio_freespace_worker);
2154         btrfs_destroy_workqueue(fs_info->submit_workers);
2155         btrfs_destroy_workqueue(fs_info->delayed_workers);
2156         btrfs_destroy_workqueue(fs_info->caching_workers);
2157         btrfs_destroy_workqueue(fs_info->readahead_workers);
2158         btrfs_destroy_workqueue(fs_info->flush_workers);
2159         btrfs_destroy_workqueue(fs_info->qgroup_rescan_workers);
2160         btrfs_destroy_workqueue(fs_info->extent_workers);
2161 }
2162 
2163 static void free_root_extent_buffers(struct btrfs_root *root)
2164 {
2165         if (root) {
2166                 free_extent_buffer(root->node);
2167                 free_extent_buffer(root->commit_root);
2168                 root->node = NULL;
2169                 root->commit_root = NULL;
2170         }
2171 }
2172 
2173 /* helper to cleanup tree roots */
2174 static void free_root_pointers(struct btrfs_fs_info *info, int chunk_root)
2175 {
2176         free_root_extent_buffers(info->tree_root);
2177 
2178         free_root_extent_buffers(info->dev_root);
2179         free_root_extent_buffers(info->extent_root);
2180         free_root_extent_buffers(info->csum_root);
2181         free_root_extent_buffers(info->quota_root);
2182         free_root_extent_buffers(info->uuid_root);
2183         if (chunk_root)
2184                 free_root_extent_buffers(info->chunk_root);
2185         free_root_extent_buffers(info->free_space_root);
2186 }
2187 
2188 void btrfs_free_fs_roots(struct btrfs_fs_info *fs_info)
2189 {
2190         int ret;
2191         struct btrfs_root *gang[8];
2192         int i;
2193 
2194         while (!list_empty(&fs_info->dead_roots)) {
2195                 gang[0] = list_entry(fs_info->dead_roots.next,
2196                                      struct btrfs_root, root_list);
2197                 list_del(&gang[0]->root_list);
2198 
2199                 if (test_bit(BTRFS_ROOT_IN_RADIX, &gang[0]->state)) {
2200                         btrfs_drop_and_free_fs_root(fs_info, gang[0]);
2201                 } else {
2202                         free_extent_buffer(gang[0]->node);
2203                         free_extent_buffer(gang[0]->commit_root);
2204                         btrfs_put_fs_root(gang[0]);
2205                 }
2206         }
2207 
2208         while (1) {
2209                 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
2210                                              (void **)gang, 0,
2211                                              ARRAY_SIZE(gang));
2212                 if (!ret)
2213                         break;
2214                 for (i = 0; i < ret; i++)
2215                         btrfs_drop_and_free_fs_root(fs_info, gang[i]);
2216         }
2217 
2218         if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) {
2219                 btrfs_free_log_root_tree(NULL, fs_info);
2220                 btrfs_destroy_pinned_extent(fs_info->tree_root,
2221                                             fs_info->pinned_extents);
2222         }
2223 }
2224 
2225 static void btrfs_init_scrub(struct btrfs_fs_info *fs_info)
2226 {
2227         mutex_init(&fs_info->scrub_lock);
2228         atomic_set(&fs_info->scrubs_running, 0);
2229         atomic_set(&fs_info->scrub_pause_req, 0);
2230         atomic_set(&fs_info->scrubs_paused, 0);
2231         atomic_set(&fs_info->scrub_cancel_req, 0);
2232         init_waitqueue_head(&fs_info->scrub_pause_wait);
2233         fs_info->scrub_workers_refcnt = 0;
2234 }
2235 
2236 static void btrfs_init_balance(struct btrfs_fs_info *fs_info)
2237 {
2238         spin_lock_init(&fs_info->balance_lock);
2239         mutex_init(&fs_info->balance_mutex);
2240         atomic_set(&fs_info->balance_running, 0);
2241         atomic_set(&fs_info->balance_pause_req, 0);
2242         atomic_set(&fs_info->balance_cancel_req, 0);
2243         fs_info->balance_ctl = NULL;
2244         init_waitqueue_head(&fs_info->balance_wait_q);
2245 }
2246 
2247 static void btrfs_init_btree_inode(struct btrfs_fs_info *fs_info,
2248                                    struct btrfs_root *tree_root)
2249 {
2250         fs_info->btree_inode->i_ino = BTRFS_BTREE_INODE_OBJECTID;
2251         set_nlink(fs_info->btree_inode, 1);
2252         /*
2253          * we set the i_size on the btree inode to the max possible int.
2254          * the real end of the address space is determined by all of
2255          * the devices in the system
2256          */
2257         fs_info->btree_inode->i_size = OFFSET_MAX;
2258         fs_info->btree_inode->i_mapping->a_ops = &btree_aops;
2259 
2260         RB_CLEAR_NODE(&BTRFS_I(fs_info->btree_inode)->rb_node);
2261         extent_io_tree_init(&BTRFS_I(fs_info->btree_inode)->io_tree,
2262                              fs_info->btree_inode->i_mapping);
2263         BTRFS_I(fs_info->btree_inode)->io_tree.track_uptodate = 0;
2264         extent_map_tree_init(&BTRFS_I(fs_info->btree_inode)->extent_tree);
2265 
2266         BTRFS_I(fs_info->btree_inode)->io_tree.ops = &btree_extent_io_ops;
2267 
2268         BTRFS_I(fs_info->btree_inode)->root = tree_root;
2269         memset(&BTRFS_I(fs_info->btree_inode)->location, 0,
2270                sizeof(struct btrfs_key));
2271         set_bit(BTRFS_INODE_DUMMY,
2272                 &BTRFS_I(fs_info->btree_inode)->runtime_flags);
2273         btrfs_insert_inode_hash(fs_info->btree_inode);
2274 }
2275 
2276 static void btrfs_init_dev_replace_locks(struct btrfs_fs_info *fs_info)
2277 {
2278         fs_info->dev_replace.lock_owner = 0;
2279         atomic_set(&fs_info->dev_replace.nesting_level, 0);
2280         mutex_init(&fs_info->dev_replace.lock_finishing_cancel_unmount);
2281         rwlock_init(&fs_info->dev_replace.lock);
2282         atomic_set(&fs_info->dev_replace.read_locks, 0);
2283         atomic_set(&fs_info->dev_replace.blocking_readers, 0);
2284         init_waitqueue_head(&fs_info->replace_wait);
2285         init_waitqueue_head(&fs_info->dev_replace.read_lock_wq);
2286 }
2287 
2288 static void btrfs_init_qgroup(struct btrfs_fs_info *fs_info)
2289 {
2290         spin_lock_init(&fs_info->qgroup_lock);
2291         mutex_init(&fs_info->qgroup_ioctl_lock);
2292         fs_info->qgroup_tree = RB_ROOT;
2293         fs_info->qgroup_op_tree = RB_ROOT;
2294         INIT_LIST_HEAD(&fs_info->dirty_qgroups);
2295         fs_info->qgroup_seq = 1;
2296         fs_info->quota_enabled = 0;
2297         fs_info->pending_quota_state = 0;
2298         fs_info->qgroup_ulist = NULL;
2299         mutex_init(&fs_info->qgroup_rescan_lock);
2300 }
2301 
2302 static int btrfs_init_workqueues(struct btrfs_fs_info *fs_info,
2303                 struct btrfs_fs_devices *fs_devices)
2304 {
2305         int max_active = fs_info->thread_pool_size;
2306         unsigned int flags = WQ_MEM_RECLAIM | WQ_FREEZABLE | WQ_UNBOUND;
2307 
2308         fs_info->workers =
2309                 btrfs_alloc_workqueue("worker", flags | WQ_HIGHPRI,
2310                                       max_active, 16);
2311 
2312         fs_info->delalloc_workers =
2313                 btrfs_alloc_workqueue("delalloc", flags, max_active, 2);
2314 
2315         fs_info->flush_workers =
2316                 btrfs_alloc_workqueue("flush_delalloc", flags, max_active, 0);
2317 
2318         fs_info->caching_workers =
2319                 btrfs_alloc_workqueue("cache", flags, max_active, 0);
2320 
2321         /*
2322          * a higher idle thresh on the submit workers makes it much more
2323          * likely that bios will be send down in a sane order to the
2324          * devices
2325          */
2326         fs_info->submit_workers =
2327                 btrfs_alloc_workqueue("submit", flags,
2328                                       min_t(u64, fs_devices->num_devices,
2329                                             max_active), 64);
2330 
2331         fs_info->fixup_workers =
2332                 btrfs_alloc_workqueue("fixup", flags, 1, 0);
2333 
2334         /*
2335          * endios are largely parallel and should have a very
2336          * low idle thresh
2337          */
2338         fs_info->endio_workers =
2339                 btrfs_alloc_workqueue("endio", flags, max_active, 4);
2340         fs_info->endio_meta_workers =
2341                 btrfs_alloc_workqueue("endio-meta", flags, max_active, 4);
2342         fs_info->endio_meta_write_workers =
2343                 btrfs_alloc_workqueue("endio-meta-write", flags, max_active, 2);
2344         fs_info->endio_raid56_workers =
2345                 btrfs_alloc_workqueue("endio-raid56", flags, max_active, 4);
2346         fs_info->endio_repair_workers =
2347                 btrfs_alloc_workqueue("endio-repair", flags, 1, 0);
2348         fs_info->rmw_workers =
2349                 btrfs_alloc_workqueue("rmw", flags, max_active, 2);
2350         fs_info->endio_write_workers =
2351                 btrfs_alloc_workqueue("endio-write", flags, max_active, 2);
2352         fs_info->endio_freespace_worker =
2353                 btrfs_alloc_workqueue("freespace-write", flags, max_active, 0);
2354         fs_info->delayed_workers =
2355                 btrfs_alloc_workqueue("delayed-meta", flags, max_active, 0);
2356         fs_info->readahead_workers =
2357                 btrfs_alloc_workqueue("readahead", flags, max_active, 2);
2358         fs_info->qgroup_rescan_workers =
2359                 btrfs_alloc_workqueue("qgroup-rescan", flags, 1, 0);
2360         fs_info->extent_workers =
2361                 btrfs_alloc_workqueue("extent-refs", flags,
2362                                       min_t(u64, fs_devices->num_devices,
2363                                             max_active), 8);
2364 
2365         if (!(fs_info->workers && fs_info->delalloc_workers &&
2366               fs_info->submit_workers && fs_info->flush_workers &&
2367               fs_info->endio_workers && fs_info->endio_meta_workers &&
2368               fs_info->endio_meta_write_workers &&
2369               fs_info->endio_repair_workers &&
2370               fs_info->endio_write_workers && fs_info->endio_raid56_workers &&
2371               fs_info->endio_freespace_worker && fs_info->rmw_workers &&
2372               fs_info->caching_workers && fs_info->readahead_workers &&
2373               fs_info->fixup_workers && fs_info->delayed_workers &&
2374               fs_info->extent_workers &&
2375               fs_info->qgroup_rescan_workers)) {
2376                 return -ENOMEM;
2377         }
2378 
2379         return 0;
2380 }
2381 
2382 static int btrfs_replay_log(struct btrfs_fs_info *fs_info,
2383                             struct btrfs_fs_devices *fs_devices)
2384 {
2385         int ret;
2386         struct btrfs_root *tree_root = fs_info->tree_root;
2387         struct btrfs_root *log_tree_root;
2388         struct btrfs_super_block *disk_super = fs_info->super_copy;
2389         u64 bytenr = btrfs_super_log_root(disk_super);
2390 
2391         if (fs_devices->rw_devices == 0) {
2392                 btrfs_warn(fs_info, "log replay required on RO media");
2393                 return -EIO;
2394         }
2395 
2396         log_tree_root = btrfs_alloc_root(fs_info, GFP_KERNEL);
2397         if (!log_tree_root)
2398                 return -ENOMEM;
2399 
2400         __setup_root(tree_root->nodesize, tree_root->sectorsize,
2401                         tree_root->stripesize, log_tree_root, fs_info,
2402                         BTRFS_TREE_LOG_OBJECTID);
2403 
2404         log_tree_root->node = read_tree_block(tree_root, bytenr,
2405                         fs_info->generation + 1);
2406         if (IS_ERR(log_tree_root->node)) {
2407                 btrfs_warn(fs_info, "failed to read log tree");
2408                 ret = PTR_ERR(log_tree_root->node);
2409                 kfree(log_tree_root);
2410                 return ret;
2411         } else if (!extent_buffer_uptodate(log_tree_root->node)) {
2412                 btrfs_err(fs_info, "failed to read log tree");
2413                 free_extent_buffer(log_tree_root->node);
2414                 kfree(log_tree_root);
2415                 return -EIO;
2416         }
2417         /* returns with log_tree_root freed on success */
2418         ret = btrfs_recover_log_trees(log_tree_root);
2419         if (ret) {
2420                 btrfs_std_error(tree_root->fs_info, ret,
2421                             "Failed to recover log tree");
2422                 free_extent_buffer(log_tree_root->node);
2423                 kfree(log_tree_root);
2424                 return ret;
2425         }
2426 
2427         if (fs_info->sb->s_flags & MS_RDONLY) {
2428                 ret = btrfs_commit_super(tree_root);
2429                 if (ret)
2430                         return ret;
2431         }
2432 
2433         return 0;
2434 }
2435 
2436 static int btrfs_read_roots(struct btrfs_fs_info *fs_info,
2437                             struct btrfs_root *tree_root)
2438 {
2439         struct btrfs_root *root;
2440         struct btrfs_key location;
2441         int ret;
2442 
2443         location.objectid = BTRFS_EXTENT_TREE_OBJECTID;
2444         location.type = BTRFS_ROOT_ITEM_KEY;
2445         location.offset = 0;
2446 
2447         root = btrfs_read_tree_root(tree_root, &location);
2448         if (IS_ERR(root))
2449                 return PTR_ERR(root);
2450         set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2451         fs_info->extent_root = root;
2452 
2453         location.objectid = BTRFS_DEV_TREE_OBJECTID;
2454         root = btrfs_read_tree_root(tree_root, &location);
2455         if (IS_ERR(root))
2456                 return PTR_ERR(root);
2457         set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2458         fs_info->dev_root = root;
2459         btrfs_init_devices_late(fs_info);
2460 
2461         location.objectid = BTRFS_CSUM_TREE_OBJECTID;
2462         root = btrfs_read_tree_root(tree_root, &location);
2463         if (IS_ERR(root))
2464                 return PTR_ERR(root);
2465         set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2466         fs_info->csum_root = root;
2467 
2468         location.objectid = BTRFS_QUOTA_TREE_OBJECTID;
2469         root = btrfs_read_tree_root(tree_root, &location);
2470         if (!IS_ERR(root)) {
2471                 set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2472                 fs_info->quota_enabled = 1;
2473                 fs_info->pending_quota_state = 1;
2474                 fs_info->quota_root = root;
2475         }
2476 
2477         location.objectid = BTRFS_UUID_TREE_OBJECTID;
2478         root = btrfs_read_tree_root(tree_root, &location);
2479         if (IS_ERR(root)) {
2480                 ret = PTR_ERR(root);
2481                 if (ret != -ENOENT)
2482                         return ret;
2483         } else {
2484                 set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2485                 fs_info->uuid_root = root;
2486         }
2487 
2488         if (btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE)) {
2489                 location.objectid = BTRFS_FREE_SPACE_TREE_OBJECTID;
2490                 root = btrfs_read_tree_root(tree_root, &location);
2491                 if (IS_ERR(root))
2492                         return PTR_ERR(root);
2493                 set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2494                 fs_info->free_space_root = root;
2495         }
2496 
2497         return 0;
2498 }
2499 
2500 int open_ctree(struct super_block *sb,
2501                struct btrfs_fs_devices *fs_devices,
2502                char *options)
2503 {
2504         u32 sectorsize;
2505         u32 nodesize;
2506         u32 stripesize;
2507         u64 generation;
2508         u64 features;
2509         struct btrfs_key location;
2510         struct buffer_head *bh;
2511         struct btrfs_super_block *disk_super;
2512         struct btrfs_fs_info *fs_info = btrfs_sb(sb);
2513         struct btrfs_root *tree_root;
2514         struct btrfs_root *chunk_root;
2515         int ret;
2516         int err = -EINVAL;
2517         int num_backups_tried = 0;
2518         int backup_index = 0;
2519         int max_active;
2520 
2521         tree_root = fs_info->tree_root = btrfs_alloc_root(fs_info, GFP_KERNEL);
2522         chunk_root = fs_info->chunk_root = btrfs_alloc_root(fs_info, GFP_KERNEL);
2523         if (!tree_root || !chunk_root) {
2524                 err = -ENOMEM;
2525                 goto fail;
2526         }
2527 
2528         ret = init_srcu_struct(&fs_info->subvol_srcu);
2529         if (ret) {
2530                 err = ret;
2531                 goto fail;
2532         }
2533 
2534         ret = setup_bdi(fs_info, &fs_info->bdi);
2535         if (ret) {
2536                 err = ret;
2537                 goto fail_srcu;
2538         }
2539 
2540         ret = percpu_counter_init(&fs_info->dirty_metadata_bytes, 0, GFP_KERNEL);
2541         if (ret) {
2542                 err = ret;
2543                 goto fail_bdi;
2544         }
2545         fs_info->dirty_metadata_batch = PAGE_SIZE *
2546                                         (1 + ilog2(nr_cpu_ids));
2547 
2548         ret = percpu_counter_init(&fs_info->delalloc_bytes, 0, GFP_KERNEL);
2549         if (ret) {
2550                 err = ret;
2551                 goto fail_dirty_metadata_bytes;
2552         }
2553 
2554         ret = percpu_counter_init(&fs_info->bio_counter, 0, GFP_KERNEL);
2555         if (ret) {
2556                 err = ret;
2557                 goto fail_delalloc_bytes;
2558         }
2559 
2560         fs_info->btree_inode = new_inode(sb);
2561         if (!fs_info->btree_inode) {
2562                 err = -ENOMEM;
2563                 goto fail_bio_counter;
2564         }
2565 
2566         mapping_set_gfp_mask(fs_info->btree_inode->i_mapping, GFP_NOFS);
2567 
2568         INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_ATOMIC);
2569         INIT_RADIX_TREE(&fs_info->buffer_radix, GFP_ATOMIC);
2570         INIT_LIST_HEAD(&fs_info->trans_list);
2571         INIT_LIST_HEAD(&fs_info->dead_roots);
2572         INIT_LIST_HEAD(&fs_info->delayed_iputs);
2573         INIT_LIST_HEAD(&fs_info->delalloc_roots);
2574         INIT_LIST_HEAD(&fs_info->caching_block_groups);
2575         spin_lock_init(&fs_info->delalloc_root_lock);
2576         spin_lock_init(&fs_info->trans_lock);
2577         spin_lock_init(&fs_info->fs_roots_radix_lock);
2578         spin_lock_init(&fs_info->delayed_iput_lock);
2579         spin_lock_init(&fs_info->defrag_inodes_lock);
2580         spin_lock_init(&fs_info->free_chunk_lock);
2581         spin_lock_init(&fs_info->tree_mod_seq_lock);
2582         spin_lock_init(&fs_info->super_lock);
2583         spin_lock_init(&fs_info->qgroup_op_lock);
2584         spin_lock_init(&fs_info->buffer_lock);
2585         spin_lock_init(&fs_info->unused_bgs_lock);
2586         rwlock_init(&fs_info->tree_mod_log_lock);
2587         mutex_init(&fs_info->unused_bg_unpin_mutex);
2588         mutex_init(&fs_info->delete_unused_bgs_mutex);
2589         mutex_init(&fs_info->reloc_mutex);
2590         mutex_init(&fs_info->delalloc_root_mutex);
2591         mutex_init(&fs_info->cleaner_delayed_iput_mutex);
2592         seqlock_init(&fs_info->profiles_lock);
2593 
2594         INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots);
2595         INIT_LIST_HEAD(&fs_info->space_info);
2596         INIT_LIST_HEAD(&fs_info->tree_mod_seq_list);
2597         INIT_LIST_HEAD(&fs_info->unused_bgs);
2598         btrfs_mapping_init(&fs_info->mapping_tree);
2599         btrfs_init_block_rsv(&fs_info->global_block_rsv,
2600                              BTRFS_BLOCK_RSV_GLOBAL);
2601         btrfs_init_block_rsv(&fs_info->delalloc_block_rsv,
2602                              BTRFS_BLOCK_RSV_DELALLOC);
2603         btrfs_init_block_rsv(&fs_info->trans_block_rsv, BTRFS_BLOCK_RSV_TRANS);
2604         btrfs_init_block_rsv(&fs_info->chunk_block_rsv, BTRFS_BLOCK_RSV_CHUNK);
2605         btrfs_init_block_rsv(&fs_info->empty_block_rsv, BTRFS_BLOCK_RSV_EMPTY);
2606         btrfs_init_block_rsv(&fs_info->delayed_block_rsv,
2607                              BTRFS_BLOCK_RSV_DELOPS);
2608         atomic_set(&fs_info->nr_async_submits, 0);
2609         atomic_set(&fs_info->async_delalloc_pages, 0);
2610         atomic_set(&fs_info->async_submit_draining, 0);
2611         atomic_set(&fs_info->nr_async_bios, 0);
2612         atomic_set(&fs_info->defrag_running, 0);
2613         atomic_set(&fs_info->qgroup_op_seq, 0);
2614         atomic_set(&fs_info->reada_works_cnt, 0);
2615         atomic64_set(&fs_info->tree_mod_seq, 0);
2616         fs_info->sb = sb;
2617         fs_info->max_inline = BTRFS_DEFAULT_MAX_INLINE;
2618         fs_info->metadata_ratio = 0;
2619         fs_info->defrag_inodes = RB_ROOT;
2620         fs_info->free_chunk_space = 0;
2621         fs_info->tree_mod_log = RB_ROOT;
2622         fs_info->commit_interval = BTRFS_DEFAULT_COMMIT_INTERVAL;
2623         fs_info->avg_delayed_ref_runtime = NSEC_PER_SEC >> 6; /* div by 64 */
2624         /* readahead state */
2625         INIT_RADIX_TREE(&fs_info->reada_tree, GFP_NOFS & ~__GFP_DIRECT_RECLAIM);
2626         spin_lock_init(&fs_info->reada_lock);
2627 
2628         fs_info->thread_pool_size = min_t(unsigned long,
2629                                           num_online_cpus() + 2, 8);
2630 
2631         INIT_LIST_HEAD(&fs_info->ordered_roots);
2632         spin_lock_init(&fs_info->ordered_root_lock);
2633         fs_info->delayed_root = kmalloc(sizeof(struct btrfs_delayed_root),
2634                                         GFP_KERNEL);
2635         if (!fs_info->delayed_root) {
2636                 err = -ENOMEM;
2637                 goto fail_iput;
2638         }
2639         btrfs_init_delayed_root(fs_info->delayed_root);
2640 
2641         btrfs_init_scrub(fs_info);
2642 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
2643         fs_info->check_integrity_print_mask = 0;
2644 #endif
2645         btrfs_init_balance(fs_info);
2646         btrfs_init_async_reclaim_work(&fs_info->async_reclaim_work);
2647 
2648         sb->s_blocksize = 4096;
2649         sb->s_blocksize_bits = blksize_bits(4096);
2650         sb->s_bdi = &fs_info->bdi;
2651 
2652         btrfs_init_btree_inode(fs_info, tree_root);
2653 
2654         spin_lock_init(&fs_info->block_group_cache_lock);
2655         fs_info->block_group_cache_tree = RB_ROOT;
2656         fs_info->first_logical_byte = (u64)-1;
2657 
2658         extent_io_tree_init(&fs_info->freed_extents[0],
2659                              fs_info->btree_inode->i_mapping);
2660         extent_io_tree_init(&fs_info->freed_extents[1],
2661                              fs_info->btree_inode->i_mapping);
2662         fs_info->pinned_extents = &fs_info->freed_extents[0];
2663         fs_info->do_barriers = 1;
2664 
2665 
2666         mutex_init(&fs_info->ordered_operations_mutex);
2667         mutex_init(&fs_info->tree_log_mutex);
2668         mutex_init(&fs_info->chunk_mutex);
2669         mutex_init(&fs_info->transaction_kthread_mutex);
2670         mutex_init(&fs_info->cleaner_mutex);
2671         mutex_init(&fs_info->volume_mutex);
2672         mutex_init(&fs_info->ro_block_group_mutex);
2673         init_rwsem(&fs_info->commit_root_sem);
2674         init_rwsem(&fs_info->cleanup_work_sem);
2675         init_rwsem(&fs_info->subvol_sem);
2676         sema_init(&fs_info->uuid_tree_rescan_sem, 1);
2677 
2678         btrfs_init_dev_replace_locks(fs_info);
2679         btrfs_init_qgroup(fs_info);
2680 
2681         btrfs_init_free_cluster(&fs_info->meta_alloc_cluster);
2682         btrfs_init_free_cluster(&fs_info->data_alloc_cluster);
2683 
2684         init_waitqueue_head(&fs_info->transaction_throttle);
2685         init_waitqueue_head(&fs_info->transaction_wait);
2686         init_waitqueue_head(&fs_info->transaction_blocked_wait);
2687         init_waitqueue_head(&fs_info->async_submit_wait);
2688 
2689         INIT_LIST_HEAD(&fs_info->pinned_chunks);
2690 
2691         ret = btrfs_alloc_stripe_hash_table(fs_info);
2692         if (ret) {
2693                 err = ret;
2694                 goto fail_alloc;
2695         }
2696 
2697         __setup_root(4096, 4096, 4096, tree_root,
2698                      fs_info, BTRFS_ROOT_TREE_OBJECTID);
2699 
2700         invalidate_bdev(fs_devices->latest_bdev);
2701 
2702         /*
2703          * Read super block and check the signature bytes only
2704          */
2705         bh = btrfs_read_dev_super(fs_devices->latest_bdev);
2706         if (IS_ERR(bh)) {
2707                 err = PTR_ERR(bh);
2708                 goto fail_alloc;
2709         }
2710 
2711         /*
2712          * We want to check superblock checksum, the type is stored inside.
2713          * Pass the whole disk block of size BTRFS_SUPER_INFO_SIZE (4k).
2714          */
2715         if (btrfs_check_super_csum(bh->b_data)) {
2716                 printk(KERN_ERR "BTRFS: superblock checksum mismatch\n");
2717                 err = -EINVAL;
2718                 brelse(bh);
2719                 goto fail_alloc;
2720         }
2721 
2722         /*
2723          * super_copy is zeroed at allocation time and we never touch the
2724          * following bytes up to INFO_SIZE, the checksum is calculated from
2725          * the whole block of INFO_SIZE
2726          */
2727         memcpy(fs_info->super_copy, bh->b_data, sizeof(*fs_info->super_copy));
2728         memcpy(fs_info->super_for_commit, fs_info->super_copy,
2729                sizeof(*fs_info->super_for_commit));
2730         brelse(bh);
2731 
2732         memcpy(fs_info->fsid, fs_info->super_copy->fsid, BTRFS_FSID_SIZE);
2733 
2734         ret = btrfs_check_super_valid(fs_info, sb->s_flags & MS_RDONLY);
2735         if (ret) {
2736                 printk(KERN_ERR "BTRFS: superblock contains fatal errors\n");
2737                 err = -EINVAL;
2738                 goto fail_alloc;
2739         }
2740 
2741         disk_super = fs_info->super_copy;
2742         if (!btrfs_super_root(disk_super))
2743                 goto fail_alloc;
2744 
2745         /* check FS state, whether FS is broken. */
2746         if (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_ERROR)
2747                 set_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state);
2748 
2749         /*
2750          * run through our array of backup supers and setup
2751          * our ring pointer to the oldest one
2752          */
2753         generation = btrfs_super_generation(disk_super);
2754         find_oldest_super_backup(fs_info, generation);
2755 
2756         /*
2757          * In the long term, we'll store the compression type in the super
2758          * block, and it'll be used for per file compression control.
2759          */
2760         fs_info->compress_type = BTRFS_COMPRESS_ZLIB;
2761 
2762         ret = btrfs_parse_options(tree_root, options, sb->s_flags);
2763         if (ret) {
2764                 err = ret;
2765                 goto fail_alloc;
2766         }
2767 
2768         features = btrfs_super_incompat_flags(disk_super) &
2769                 ~BTRFS_FEATURE_INCOMPAT_SUPP;
2770         if (features) {
2771                 printk(KERN_ERR "BTRFS: couldn't mount because of "
2772                        "unsupported optional features (%Lx).\n",
2773                        features);
2774                 err = -EINVAL;
2775                 goto fail_alloc;
2776         }
2777 
2778         features = btrfs_super_incompat_flags(disk_super);
2779         features |= BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF;
2780         if (tree_root->fs_info->compress_type == BTRFS_COMPRESS_LZO)
2781                 features |= BTRFS_FEATURE_INCOMPAT_COMPRESS_LZO;
2782 
2783         if (features & BTRFS_FEATURE_INCOMPAT_SKINNY_METADATA)
2784                 printk(KERN_INFO "BTRFS: has skinny extents\n");
2785 
2786         /*
2787          * flag our filesystem as having big metadata blocks if
2788          * they are bigger than the page size
2789          */
2790         if (btrfs_super_nodesize(disk_super) > PAGE_SIZE) {
2791                 if (!(features & BTRFS_FEATURE_INCOMPAT_BIG_METADATA))
2792                         printk(KERN_INFO "BTRFS: flagging fs with big metadata feature\n");
2793                 features |= BTRFS_FEATURE_INCOMPAT_BIG_METADATA;
2794         }
2795 
2796         nodesize = btrfs_super_nodesize(disk_super);
2797         sectorsize = btrfs_super_sectorsize(disk_super);
2798         stripesize = btrfs_super_stripesize(disk_super);
2799         fs_info->dirty_metadata_batch = nodesize * (1 + ilog2(nr_cpu_ids));
2800         fs_info->delalloc_batch = sectorsize * 512 * (1 + ilog2(nr_cpu_ids));
2801 
2802         /*
2803          * mixed block groups end up with duplicate but slightly offset
2804          * extent buffers for the same range.  It leads to corruptions
2805          */
2806         if ((features & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS) &&
2807             (sectorsize != nodesize)) {
2808                 printk(KERN_ERR "BTRFS: unequal leaf/node/sector sizes "
2809                                 "are not allowed for mixed block groups on %s\n",
2810                                 sb->s_id);
2811                 goto fail_alloc;
2812         }
2813 
2814         /*
2815          * Needn't use the lock because there is no other task which will
2816          * update the flag.
2817          */
2818         btrfs_set_super_incompat_flags(disk_super, features);
2819 
2820         features = btrfs_super_compat_ro_flags(disk_super) &
2821                 ~BTRFS_FEATURE_COMPAT_RO_SUPP;
2822         if (!(sb->s_flags & MS_RDONLY) && features) {
2823                 printk(KERN_ERR "BTRFS: couldn't mount RDWR because of "
2824                        "unsupported option features (%Lx).\n",
2825                        features);
2826                 err = -EINVAL;
2827                 goto fail_alloc;
2828         }
2829 
2830         max_active = fs_info->thread_pool_size;
2831 
2832         ret = btrfs_init_workqueues(fs_info, fs_devices);
2833         if (ret) {
2834                 err = ret;
2835                 goto fail_sb_buffer;
2836         }
2837 
2838         fs_info->bdi.ra_pages *= btrfs_super_num_devices(disk_super);
2839         fs_info->bdi.ra_pages = max(fs_info->bdi.ra_pages,
2840                                     SZ_4M / PAGE_SIZE);
2841 
2842         tree_root->nodesize = nodesize;
2843         tree_root->sectorsize = sectorsize;
2844         tree_root->stripesize = stripesize;
2845 
2846         sb->s_blocksize = sectorsize;
2847         sb->s_blocksize_bits = blksize_bits(sectorsize);
2848 
2849         mutex_lock(&fs_info->chunk_mutex);
2850         ret = btrfs_read_sys_array(tree_root);
2851         mutex_unlock(&fs_info->chunk_mutex);
2852         if (ret) {
2853                 printk(KERN_ERR "BTRFS: failed to read the system "
2854                        "array on %s\n", sb->s_id);
2855                 goto fail_sb_buffer;
2856         }
2857 
2858         generation = btrfs_super_chunk_root_generation(disk_super);
2859 
2860         __setup_root(nodesize, sectorsize, stripesize, chunk_root,
2861                      fs_info, BTRFS_CHUNK_TREE_OBJECTID);
2862 
2863         chunk_root->node = read_tree_block(chunk_root,
2864                                            btrfs_super_chunk_root(disk_super),
2865                                            generation);
2866         if (IS_ERR(chunk_root->node) ||
2867             !extent_buffer_uptodate(chunk_root->node)) {
2868                 printk(KERN_ERR "BTRFS: failed to read chunk root on %s\n",
2869                        sb->s_id);
2870                 if (!IS_ERR(chunk_root->node))
2871                         free_extent_buffer(chunk_root->node);
2872                 chunk_root->node = NULL;
2873                 goto fail_tree_roots;
2874         }
2875         btrfs_set_root_node(&chunk_root->root_item, chunk_root->node);
2876         chunk_root->commit_root = btrfs_root_node(chunk_root);
2877 
2878         read_extent_buffer(chunk_root->node, fs_info->chunk_tree_uuid,
2879            btrfs_header_chunk_tree_uuid(chunk_root->node), BTRFS_UUID_SIZE);
2880 
2881         ret = btrfs_read_chunk_tree(chunk_root);
2882         if (ret) {
2883                 printk(KERN_ERR "BTRFS: failed to read chunk tree on %s\n",
2884                        sb->s_id);
2885                 goto fail_tree_roots;
2886         }
2887 
2888         /*
2889          * keep the device that is marked to be the target device for the
2890          * dev_replace procedure
2891          */
2892         btrfs_close_extra_devices(fs_devices, 0);
2893 
2894         if (!fs_devices->latest_bdev) {
2895                 printk(KERN_ERR "BTRFS: failed to read devices on %s\n",
2896                        sb->s_id);
2897                 goto fail_tree_roots;
2898         }
2899 
2900 retry_root_backup:
2901         generation = btrfs_super_generation(disk_super);
2902 
2903         tree_root->node = read_tree_block(tree_root,
2904                                           btrfs_super_root(disk_super),
2905                                           generation);
2906         if (IS_ERR(tree_root->node) ||
2907             !extent_buffer_uptodate(tree_root->node)) {
2908                 printk(KERN_WARNING "BTRFS: failed to read tree root on %s\n",
2909                        sb->s_id);
2910                 if (!IS_ERR(tree_root->node))
2911                         free_extent_buffer(tree_root->node);
2912                 tree_root->node = NULL;
2913                 goto recovery_tree_root;
2914         }
2915 
2916         btrfs_set_root_node(&tree_root->root_item, tree_root->node);
2917         tree_root->commit_root = btrfs_root_node(tree_root);
2918         btrfs_set_root_refs(&tree_root->root_item, 1);
2919 
2920         mutex_lock(&tree_root->objectid_mutex);
2921         ret = btrfs_find_highest_objectid(tree_root,
2922                                         &tree_root->highest_objectid);
2923         if (ret) {
2924                 mutex_unlock(&tree_root->objectid_mutex);
2925                 goto recovery_tree_root;
2926         }
2927 
2928         ASSERT(tree_root->highest_objectid <= BTRFS_LAST_FREE_OBJECTID);
2929 
2930         mutex_unlock(&tree_root->objectid_mutex);
2931 
2932         ret = btrfs_read_roots(fs_info, tree_root);
2933         if (ret)
2934                 goto recovery_tree_root;
2935 
2936         fs_info->generation = generation;
2937         fs_info->last_trans_committed = generation;
2938 
2939         ret = btrfs_recover_balance(fs_info);
2940         if (ret) {
2941                 printk(KERN_ERR "BTRFS: failed to recover balance\n");
2942                 goto fail_block_groups;
2943         }
2944 
2945         ret = btrfs_init_dev_stats(fs_info);
2946         if (ret) {
2947                 printk(KERN_ERR "BTRFS: failed to init dev_stats: %d\n",
2948                        ret);
2949                 goto fail_block_groups;
2950         }
2951 
2952         ret = btrfs_init_dev_replace(fs_info);
2953         if (ret) {
2954                 pr_err("BTRFS: failed to init dev_replace: %d\n", ret);
2955                 goto fail_block_groups;
2956         }
2957 
2958         btrfs_close_extra_devices(fs_devices, 1);
2959 
2960         ret = btrfs_sysfs_add_fsid(fs_devices, NULL);
2961         if (ret) {
2962                 pr_err("BTRFS: failed to init sysfs fsid interface: %d\n", ret);
2963                 goto fail_block_groups;
2964         }
2965 
2966         ret = btrfs_sysfs_add_device(fs_devices);
2967         if (ret) {
2968                 pr_err("BTRFS: failed to init sysfs device interface: %d\n", ret);
2969                 goto fail_fsdev_sysfs;
2970         }
2971 
2972         ret = btrfs_sysfs_add_mounted(fs_info);
2973         if (ret) {
2974                 pr_err("BTRFS: failed to init sysfs interface: %d\n", ret);
2975                 goto fail_fsdev_sysfs;
2976         }
2977 
2978         ret = btrfs_init_space_info(fs_info);
2979         if (ret) {
2980                 printk(KERN_ERR "BTRFS: Failed to initial space info: %d\n", ret);
2981                 goto fail_sysfs;
2982         }
2983 
2984         ret = btrfs_read_block_groups(fs_info->extent_root);
2985         if (ret) {
2986                 printk(KERN_ERR "BTRFS: Failed to read block groups: %d\n", ret);
2987                 goto fail_sysfs;
2988         }
2989         fs_info->num_tolerated_disk_barrier_failures =
2990                 btrfs_calc_num_tolerated_disk_barrier_failures(fs_info);
2991         if (fs_info->fs_devices->missing_devices >
2992              fs_info->num_tolerated_disk_barrier_failures &&
2993             !(sb->s_flags & MS_RDONLY)) {
2994                 pr_warn("BTRFS: missing devices(%llu) exceeds the limit(%d), writeable mount is not allowed\n",
2995                         fs_info->fs_devices->missing_devices,
2996                         fs_info->num_tolerated_disk_barrier_failures);
2997                 goto fail_sysfs;
2998         }
2999 
3000         fs_info->cleaner_kthread = kthread_run(cleaner_kthread, tree_root,
3001                                                "btrfs-cleaner");
3002         if (IS_ERR(fs_info->cleaner_kthread))
3003                 goto fail_sysfs;
3004 
3005         fs_info->transaction_kthread = kthread_run(transaction_kthread,
3006                                                    tree_root,
3007                                                    "btrfs-transaction");
3008         if (IS_ERR(fs_info->transaction_kthread))
3009                 goto fail_cleaner;
3010 
3011         if (!btrfs_test_opt(tree_root, SSD) &&
3012             !btrfs_test_opt(tree_root, NOSSD) &&
3013             !fs_info->fs_devices->rotating) {
3014                 printk(KERN_INFO "BTRFS: detected SSD devices, enabling SSD "
3015                        "mode\n");
3016                 btrfs_set_opt(fs_info->mount_opt, SSD);
3017         }
3018 
3019         /*
3020          * Mount does not set all options immediatelly, we can do it now and do
3021          * not have to wait for transaction commit
3022          */
3023         btrfs_apply_pending_changes(fs_info);
3024 
3025 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
3026         if (btrfs_test_opt(tree_root, CHECK_INTEGRITY)) {
3027                 ret = btrfsic_mount(tree_root, fs_devices,
3028                                     btrfs_test_opt(tree_root,
3029                                         CHECK_INTEGRITY_INCLUDING_EXTENT_DATA) ?
3030                                     1 : 0,
3031                                     fs_info->check_integrity_print_mask);
3032                 if (ret)
3033                         printk(KERN_WARNING "BTRFS: failed to initialize"
3034                                " integrity check module %s\n", sb->s_id);
3035         }
3036 #endif
3037         ret = btrfs_read_qgroup_config(fs_info);
3038         if (ret)
3039                 goto fail_trans_kthread;
3040 
3041         /* do not make disk changes in broken FS or nologreplay is given */
3042         if (btrfs_super_log_root(disk_super) != 0 &&
3043             !btrfs_test_opt(tree_root, NOLOGREPLAY)) {
3044                 ret = btrfs_replay_log(fs_info, fs_devices);
3045                 if (ret) {
3046                         err = ret;
3047                         goto fail_qgroup;
3048                 }
3049         }
3050 
3051         ret = btrfs_find_orphan_roots(tree_root);
3052         if (ret)
3053                 goto fail_qgroup;
3054 
3055         if (!(sb->s_flags & MS_RDONLY)) {
3056                 ret = btrfs_cleanup_fs_roots(fs_info);
3057                 if (ret)
3058                         goto fail_qgroup;
3059 
3060                 mutex_lock(&fs_info->cleaner_mutex);
3061                 ret = btrfs_recover_relocation(tree_root);
3062                 mutex_unlock(&fs_info->cleaner_mutex);
3063                 if (ret < 0) {
3064                         printk(KERN_WARNING
3065                                "BTRFS: failed to recover relocation\n");
3066                         err = -EINVAL;
3067                         goto fail_qgroup;
3068                 }
3069         }
3070 
3071         location.objectid = BTRFS_FS_TREE_OBJECTID;
3072         location.type = BTRFS_ROOT_ITEM_KEY;
3073         location.offset = 0;
3074 
3075         fs_info->fs_root = btrfs_read_fs_root_no_name(fs_info, &location);
3076         if (IS_ERR(fs_info->fs_root)) {
3077                 err = PTR_ERR(fs_info->fs_root);
3078                 goto fail_qgroup;
3079         }
3080 
3081         if (sb->s_flags & MS_RDONLY)
3082                 return 0;
3083 
3084         if (btrfs_test_opt(tree_root, FREE_SPACE_TREE) &&
3085             !btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE)) {
3086                 pr_info("BTRFS: creating free space tree\n");
3087                 ret = btrfs_create_free_space_tree(fs_info);
3088                 if (ret) {
3089                         pr_warn("BTRFS: failed to create free space tree %d\n",
3090                                 ret);
3091                         close_ctree(tree_root);
3092                         return ret;
3093                 }
3094         }
3095 
3096         down_read(&fs_info->cleanup_work_sem);
3097         if ((ret = btrfs_orphan_cleanup(fs_info->fs_root)) ||
3098             (ret = btrfs_orphan_cleanup(fs_info->tree_root))) {
3099                 up_read(&fs_info->cleanup_work_sem);
3100                 close_ctree(tree_root);
3101                 return ret;
3102         }
3103         up_read(&fs_info->cleanup_work_sem);
3104 
3105         ret = btrfs_resume_balance_async(fs_info);
3106         if (ret) {
3107                 printk(KERN_WARNING "BTRFS: failed to resume balance\n");
3108                 close_ctree(tree_root);
3109                 return ret;
3110         }
3111 
3112         ret = btrfs_resume_dev_replace_async(fs_info);
3113         if (ret) {
3114                 pr_warn("BTRFS: failed to resume dev_replace\n");
3115                 close_ctree(tree_root);
3116                 return ret;
3117         }
3118 
3119         btrfs_qgroup_rescan_resume(fs_info);
3120 
3121         if (btrfs_test_opt(tree_root, CLEAR_CACHE) &&
3122             btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE)) {
3123                 pr_info("BTRFS: clearing free space tree\n");
3124                 ret = btrfs_clear_free_space_tree(fs_info);
3125                 if (ret) {
3126                         pr_warn("BTRFS: failed to clear free space tree %d\n",
3127                                 ret);
3128                         close_ctree(tree_root);
3129                         return ret;
3130                 }
3131         }
3132 
3133         if (!fs_info->uuid_root) {
3134                 pr_info("BTRFS: creating UUID tree\n");
3135                 ret = btrfs_create_uuid_tree(fs_info);
3136                 if (ret) {
3137                         pr_warn("BTRFS: failed to create the UUID tree %d\n",
3138                                 ret);
3139                         close_ctree(tree_root);
3140                         return ret;
3141                 }
3142         } else if (btrfs_test_opt(tree_root, RESCAN_UUID_TREE) ||
3143                    fs_info->generation !=
3144                                 btrfs_super_uuid_tree_generation(disk_super)) {
3145                 pr_info("BTRFS: checking UUID tree\n");
3146                 ret = btrfs_check_uuid_tree(fs_info);
3147                 if (ret) {
3148                         pr_warn("BTRFS: failed to check the UUID tree %d\n",
3149                                 ret);
3150                         close_ctree(tree_root);
3151                         return ret;
3152                 }
3153         } else {
3154                 fs_info->update_uuid_tree_gen = 1;
3155         }
3156 
3157         fs_info->open = 1;
3158 
3159         /*
3160          * backuproot only affect mount behavior, and if open_ctree succeeded,
3161          * no need to keep the flag
3162          */
3163         btrfs_clear_opt(fs_info->mount_opt, USEBACKUPROOT);
3164 
3165         return 0;
3166 
3167 fail_qgroup:
3168         btrfs_free_qgroup_config(fs_info);
3169 fail_trans_kthread:
3170         kthread_stop(fs_info->transaction_kthread);
3171         btrfs_cleanup_transaction(fs_info->tree_root);
3172         btrfs_free_fs_roots(fs_info);
3173 fail_cleaner:
3174         kthread_stop(fs_info->cleaner_kthread);
3175 
3176         /*
3177          * make sure we're done with the btree inode before we stop our
3178          * kthreads
3179          */
3180         filemap_write_and_wait(fs_info->btree_inode->i_mapping);
3181 
3182 fail_sysfs:
3183         btrfs_sysfs_remove_mounted(fs_info);
3184 
3185 fail_fsdev_sysfs:
3186         btrfs_sysfs_remove_fsid(fs_info->fs_devices);
3187 
3188 fail_block_groups:
3189         btrfs_put_block_group_cache(fs_info);
3190         btrfs_free_block_groups(fs_info);
3191 
3192 fail_tree_roots:
3193         free_root_pointers(fs_info, 1);
3194         invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
3195 
3196 fail_sb_buffer:
3197         btrfs_stop_all_workers(fs_info);
3198 fail_alloc:
3199 fail_iput:
3200         btrfs_mapping_tree_free(&fs_info->mapping_tree);
3201 
3202         iput(fs_info->btree_inode);
3203 fail_bio_counter:
3204         percpu_counter_destroy(&fs_info->bio_counter);
3205 fail_delalloc_bytes:
3206         percpu_counter_destroy(&fs_info->delalloc_bytes);
3207 fail_dirty_metadata_bytes:
3208         percpu_counter_destroy(&fs_info->dirty_metadata_bytes);
3209 fail_bdi:
3210         bdi_destroy(&fs_info->bdi);
3211 fail_srcu:
3212         cleanup_srcu_struct(&fs_info->subvol_srcu);
3213 fail:
3214         btrfs_free_stripe_hash_table(fs_info);
3215         btrfs_close_devices(fs_info->fs_devices);
3216         return err;
3217 
3218 recovery_tree_root:
3219         if (!btrfs_test_opt(tree_root, USEBACKUPROOT))
3220                 goto fail_tree_roots;
3221 
3222         free_root_pointers(fs_info, 0);
3223 
3224         /* don't use the log in recovery mode, it won't be valid */
3225         btrfs_set_super_log_root(disk_super, 0);
3226 
3227         /* we can't trust the free space cache either */
3228         btrfs_set_opt(fs_info->mount_opt, CLEAR_CACHE);
3229 
3230         ret = next_root_backup(fs_info, fs_info->super_copy,
3231                                &num_backups_tried, &backup_index);
3232         if (ret == -1)
3233                 goto fail_block_groups;
3234         goto retry_root_backup;
3235 }
3236 
3237 static void btrfs_end_buffer_write_sync(struct buffer_head *bh, int uptodate)
3238 {
3239         if (uptodate) {
3240                 set_buffer_uptodate(bh);
3241         } else {
3242                 struct btrfs_device *device = (struct btrfs_device *)
3243                         bh->b_private;
3244 
3245                 btrfs_warn_rl_in_rcu(device->dev_root->fs_info,
3246                                 "lost page write due to IO error on %s",
3247                                           rcu_str_deref(device->name));
3248                 /* note, we dont' set_buffer_write_io_error because we have
3249                  * our own ways of dealing with the IO errors
3250                  */
3251                 clear_buffer_uptodate(bh);
3252                 btrfs_dev_stat_inc_and_print(device, BTRFS_DEV_STAT_WRITE_ERRS);
3253         }
3254         unlock_buffer(bh);
3255         put_bh(bh);
3256 }
3257 
3258 int btrfs_read_dev_one_super(struct block_device *bdev, int copy_num,
3259                         struct buffer_head **bh_ret)
3260 {
3261         struct buffer_head *bh;
3262         struct btrfs_super_block *super;
3263         u64 bytenr;
3264 
3265         bytenr = btrfs_sb_offset(copy_num);
3266         if (bytenr + BTRFS_SUPER_INFO_SIZE >= i_size_read(bdev->bd_inode))
3267                 return -EINVAL;
3268 
3269         bh = __bread(bdev, bytenr / 4096, BTRFS_SUPER_INFO_SIZE);
3270         /*
3271          * If we fail to read from the underlying devices, as of now
3272          * the best option we have is to mark it EIO.
3273          */
3274         if (!bh)
3275                 return -EIO;
3276 
3277         super = (struct btrfs_super_block *)bh->b_data;
3278         if (btrfs_super_bytenr(super) != bytenr ||
3279                     btrfs_super_magic(super) != BTRFS_MAGIC) {
3280                 brelse(bh);
3281                 return -EINVAL;
3282         }
3283 
3284         *bh_ret = bh;
3285         return 0;
3286 }
3287 
3288 
3289 struct buffer_head *btrfs_read_dev_super(struct block_device *bdev)
3290 {
3291         struct buffer_head *bh;
3292         struct buffer_head *latest = NULL;
3293         struct btrfs_super_block *super;
3294         int i;
3295         u64 transid = 0;
3296         int ret = -EINVAL;
3297 
3298         /* we would like to check all the supers, but that would make
3299          * a btrfs mount succeed after a mkfs from a different FS.
3300          * So, we need to add a special mount option to scan for
3301          * later supers, using BTRFS_SUPER_MIRROR_MAX instead
3302          */
3303         for (i = 0; i < 1; i++) {
3304                 ret = btrfs_read_dev_one_super(bdev, i, &bh);
3305                 if (ret)
3306                         continue;
3307 
3308                 super = (struct btrfs_super_block *)bh->b_data;
3309 
3310                 if (!latest || btrfs_super_generation(super) > transid) {
3311                         brelse(latest);
3312                         latest = bh;
3313                         transid = btrfs_super_generation(super);
3314                 } else {
3315                         brelse(bh);
3316                 }
3317         }
3318 
3319         if (!latest)
3320                 return ERR_PTR(ret);
3321 
3322         return latest;
3323 }
3324 
3325 /*
3326  * this should be called twice, once with wait == 0 and
3327  * once with wait == 1.  When wait == 0 is done, all the buffer heads
3328  * we write are pinned.
3329  *
3330  * They are released when wait == 1 is done.
3331  * max_mirrors must be the same for both runs, and it indicates how
3332  * many supers on this one device should be written.
3333  *
3334  * max_mirrors == 0 means to write them all.
3335  */
3336 static int write_dev_supers(struct btrfs_device *device,
3337                             struct btrfs_super_block *sb,
3338                             int do_barriers, int wait, int max_mirrors)
3339 {
3340         struct buffer_head *bh;
3341         int i;
3342         int ret;
3343         int errors = 0;
3344         u32 crc;
3345         u64 bytenr;
3346 
3347         if (max_mirrors == 0)
3348                 max_mirrors = BTRFS_SUPER_MIRROR_MAX;
3349 
3350         for (i = 0; i < max_mirrors; i++) {
3351                 bytenr = btrfs_sb_offset(i);
3352                 if (bytenr + BTRFS_SUPER_INFO_SIZE >=
3353                     device->commit_total_bytes)
3354                         break;
3355 
3356                 if (wait) {
3357                         bh = __find_get_block(device->bdev, bytenr / 4096,
3358                                               BTRFS_SUPER_INFO_SIZE);
3359                         if (!bh) {
3360                                 errors++;
3361                                 continue;
3362                         }
3363                         wait_on_buffer(bh);
3364                         if (!buffer_uptodate(bh))
3365                                 errors++;
3366 
3367                         /* drop our reference */
3368                         brelse(bh);
3369 
3370                         /* drop the reference from the wait == 0 run */
3371                         brelse(bh);
3372                         continue;
3373                 } else {
3374                         btrfs_set_super_bytenr(sb, bytenr);
3375 
3376                         crc = ~(u32)0;
3377                         crc = btrfs_csum_data((char *)sb +
3378                                               BTRFS_CSUM_SIZE, crc,
3379                                               BTRFS_SUPER_INFO_SIZE -
3380                                               BTRFS_CSUM_SIZE);
3381                         btrfs_csum_final(crc, sb->csum);
3382 
3383                         /*
3384                          * one reference for us, and we leave it for the
3385                          * caller
3386                          */
3387                         bh = __getblk(device->bdev, bytenr / 4096,
3388                                       BTRFS_SUPER_INFO_SIZE);
3389                         if (!bh) {
3390                                 btrfs_err(device->dev_root->fs_info,
3391                                     "couldn't get super buffer head for bytenr %llu",
3392                                     bytenr);
3393                                 errors++;
3394                                 continue;
3395                         }
3396 
3397                         memcpy(bh->b_data, sb, BTRFS_SUPER_INFO_SIZE);
3398 
3399                         /* one reference for submit_bh */
3400                         get_bh(bh);
3401 
3402                         set_buffer_uptodate(bh);
3403                         lock_buffer(bh);
3404                         bh->b_end_io = btrfs_end_buffer_write_sync;
3405                         bh->b_private = device;
3406                 }
3407 
3408                 /*
3409                  * we fua the first super.  The others we allow
3410                  * to go down lazy.
3411                  */
3412                 if (i == 0)
3413                         ret = btrfsic_submit_bh(WRITE_FUA, bh);
3414                 else
3415                         ret = btrfsic_submit_bh(WRITE_SYNC, bh);
3416                 if (ret)
3417                         errors++;
3418         }
3419         return errors < i ? 0 : -1;
3420 }
3421 
3422 /*
3423  * endio for the write_dev_flush, this will wake anyone waiting
3424  * for the barrier when it is done
3425  */
3426 static void btrfs_end_empty_barrier(struct bio *bio)
3427 {
3428         if (bio->bi_private)
3429                 complete(bio->bi_private);
3430         bio_put(bio);
3431 }
3432 
3433 /*
3434  * trigger flushes for one the devices.  If you pass wait == 0, the flushes are
3435  * sent down.  With wait == 1, it waits for the previous flush.
3436  *
3437  * any device where the flush fails with eopnotsupp are flagged as not-barrier
3438  * capable
3439  */
3440 static int write_dev_flush(struct btrfs_device *device, int wait)
3441 {
3442         struct bio *bio;
3443         int ret = 0;
3444 
3445         if (device->nobarriers)
3446                 return 0;
3447 
3448         if (wait) {
3449                 bio = device->flush_bio;
3450                 if (!bio)
3451                         return 0;
3452 
3453                 wait_for_completion(&device->flush_wait);
3454 
3455                 if (bio->bi_error) {
3456                         ret = bio->bi_error;
3457                         btrfs_dev_stat_inc_and_print(device,
3458                                 BTRFS_DEV_STAT_FLUSH_ERRS);
3459                 }
3460 
3461                 /* drop the reference from the wait == 0 run */
3462                 bio_put(bio);
3463                 device->flush_bio = NULL;
3464 
3465                 return ret;
3466         }
3467 
3468         /*
3469          * one reference for us, and we leave it for the
3470          * caller
3471          */
3472         device->flush_bio = NULL;
3473         bio = btrfs_io_bio_alloc(GFP_NOFS, 0);
3474         if (!bio)
3475                 return -ENOMEM;
3476 
3477         bio->bi_end_io = btrfs_end_empty_barrier;
3478         bio->bi_bdev = device->bdev;
3479         init_completion(&device->flush_wait);
3480         bio->bi_private = &device->flush_wait;
3481         device->flush_bio = bio;
3482 
3483         bio_get(bio);
3484         btrfsic_submit_bio(WRITE_FLUSH, bio);
3485 
3486         return 0;
3487 }
3488 
3489 /*
3490  * send an empty flush down to each device in parallel,
3491  * then wait for them
3492  */
3493 static int barrier_all_devices(struct btrfs_fs_info *info)
3494 {
3495         struct list_head *head;
3496         struct btrfs_device *dev;
3497         int errors_send = 0;
3498         int errors_wait = 0;
3499         int ret;
3500 
3501         /* send down all the barriers */
3502         head = &info->fs_devices->devices;
3503         list_for_each_entry_rcu(dev, head, dev_list) {
3504                 if (dev->missing)
3505                         continue;
3506                 if (!dev->bdev) {
3507                         errors_send++;
3508                         continue;
3509                 }
3510                 if (!dev->in_fs_metadata || !dev->writeable)
3511                         continue;
3512 
3513                 ret = write_dev_flush(dev, 0);
3514                 if (ret)
3515                         errors_send++;
3516         }
3517 
3518         /* wait for all the barriers */
3519         list_for_each_entry_rcu(dev, head, dev_list) {
3520                 if (dev->missing)
3521                         continue;
3522                 if (!dev->bdev) {
3523                         errors_wait++;
3524                         continue;
3525                 }
3526                 if (!dev->in_fs_metadata || !dev->writeable)
3527                         continue;
3528 
3529                 ret = write_dev_flush(dev, 1);
3530                 if (ret)
3531                         errors_wait++;
3532         }
3533         if (errors_send > info->num_tolerated_disk_barrier_failures ||
3534             errors_wait > info->num_tolerated_disk_barrier_failures)
3535                 return -EIO;
3536         return 0;
3537 }
3538 
3539 int btrfs_get_num_tolerated_disk_barrier_failures(u64 flags)
3540 {
3541         int raid_type;
3542         int min_tolerated = INT_MAX;
3543 
3544         if ((flags & BTRFS_BLOCK_GROUP_PROFILE_MASK) == 0 ||
3545             (flags & BTRFS_AVAIL_ALLOC_BIT_SINGLE))
3546                 min_tolerated = min(min_tolerated,
3547                                     btrfs_raid_array[BTRFS_RAID_SINGLE].
3548                                     tolerated_failures);
3549 
3550         for (raid_type = 0; raid_type < BTRFS_NR_RAID_TYPES; raid_type++) {
3551                 if (raid_type == BTRFS_RAID_SINGLE)
3552                         continue;
3553                 if (!(flags & btrfs_raid_group[raid_type]))
3554                         continue;
3555                 min_tolerated = min(min_tolerated,
3556                                     btrfs_raid_array[raid_type].
3557                                     tolerated_failures);
3558         }
3559 
3560         if (min_tolerated == INT_MAX) {
3561                 pr_warn("BTRFS: unknown raid flag: %llu\n", flags);
3562                 min_tolerated = 0;
3563         }
3564 
3565         return min_tolerated;
3566 }
3567 
3568 int btrfs_calc_num_tolerated_disk_barrier_failures(
3569         struct btrfs_fs_info *fs_info)
3570 {
3571         struct btrfs_ioctl_space_info space;
3572         struct btrfs_space_info *sinfo;
3573         u64 types[] = {BTRFS_BLOCK_GROUP_DATA,
3574                        BTRFS_BLOCK_GROUP_SYSTEM,
3575                        BTRFS_BLOCK_GROUP_METADATA,
3576                        BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA};
3577         int i;
3578         int c;
3579         int num_tolerated_disk_barrier_failures =
3580                 (int)fs_info->fs_devices->num_devices;
3581 
3582         for (i = 0; i < ARRAY_SIZE(types); i++) {
3583                 struct btrfs_space_info *tmp;
3584 
3585                 sinfo = NULL;
3586                 rcu_read_lock();
3587                 list_for_each_entry_rcu(tmp, &fs_info->space_info, list) {
3588                         if (tmp->flags == types[i]) {
3589                                 sinfo = tmp;
3590                                 break;
3591                         }
3592                 }
3593                 rcu_read_unlock();
3594 
3595                 if (!sinfo)
3596                         continue;
3597 
3598                 down_read(&sinfo->groups_sem);
3599                 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
3600                         u64 flags;
3601 
3602                         if (list_empty(&sinfo->block_groups[c]))
3603                                 continue;
3604 
3605                         btrfs_get_block_group_info(&sinfo->block_groups[c],
3606                                                    &space);
3607                         if (space.total_bytes == 0 || space.used_bytes == 0)
3608                                 continue;
3609                         flags = space.flags;
3610 
3611                         num_tolerated_disk_barrier_failures = min(
3612                                 num_tolerated_disk_barrier_failures,
3613                                 btrfs_get_num_tolerated_disk_barrier_failures(
3614                                         flags));
3615                 }
3616                 up_read(&sinfo->groups_sem);
3617         }
3618 
3619         return num_tolerated_disk_barrier_failures;
3620 }
3621 
3622 static int write_all_supers(struct btrfs_root *root, int max_mirrors)
3623 {
3624         struct list_head *head;
3625         struct btrfs_device *dev;
3626         struct btrfs_super_block *sb;
3627         struct btrfs_dev_item *dev_item;
3628         int ret;
3629         int do_barriers;
3630         int max_errors;
3631         int total_errors = 0;
3632         u64 flags;
3633 
3634         do_barriers = !btrfs_test_opt(root, NOBARRIER);
3635         backup_super_roots(root->fs_info);
3636 
3637         sb = root->fs_info->super_for_commit;
3638         dev_item = &sb->dev_item;
3639 
3640         mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
3641         head = &root->fs_info->fs_devices->devices;
3642         max_errors = btrfs_super_num_devices(root->fs_info->super_copy) - 1;
3643 
3644         if (do_barriers) {
3645                 ret = barrier_all_devices(root->fs_info);
3646                 if (ret) {
3647                         mutex_unlock(
3648                                 &root->fs_info->fs_devices->device_list_mutex);
3649                         btrfs_std_error(root->fs_info, ret,
3650                                     "errors while submitting device barriers.");
3651                         return ret;
3652                 }
3653         }
3654 
3655         list_for_each_entry_rcu(dev, head, dev_list) {
3656                 if (!dev->bdev) {
3657                         total_errors++;
3658                         continue;
3659                 }
3660                 if (!dev->in_fs_metadata || !dev->writeable)
3661                         continue;
3662 
3663                 btrfs_set_stack_device_generation(dev_item, 0);
3664                 btrfs_set_stack_device_type(dev_item, dev->type);
3665                 btrfs_set_stack_device_id(dev_item, dev->devid);
3666                 btrfs_set_stack_device_total_bytes(dev_item,
3667                                                    dev->commit_total_bytes);
3668                 btrfs_set_stack_device_bytes_used(dev_item,
3669                                                   dev->commit_bytes_used);
3670                 btrfs_set_stack_device_io_align(dev_item, dev->io_align);
3671                 btrfs_set_stack_device_io_width(dev_item, dev->io_width);
3672                 btrfs_set_stack_device_sector_size(dev_item, dev->sector_size);
3673                 memcpy(dev_item->uuid, dev->uuid, BTRFS_UUID_SIZE);
3674                 memcpy(dev_item->fsid, dev->fs_devices->fsid, BTRFS_UUID_SIZE);
3675 
3676                 flags = btrfs_super_flags(sb);
3677                 btrfs_set_super_flags(sb, flags | BTRFS_HEADER_FLAG_WRITTEN);
3678 
3679                 ret = write_dev_supers(dev, sb, do_barriers, 0, max_mirrors);
3680                 if (ret)
3681                         total_errors++;
3682         }
3683         if (total_errors > max_errors) {
3684                 btrfs_err(root->fs_info, "%d errors while writing supers",
3685                        total_errors);
3686                 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
3687 
3688                 /* FUA is masked off if unsupported and can't be the reason */
3689                 btrfs_std_error(root->fs_info, -EIO,
3690                             "%d errors while writing supers", total_errors);
3691                 return -EIO;
3692         }
3693 
3694         total_errors = 0;
3695         list_for_each_entry_rcu(dev, head, dev_list) {
3696                 if (!dev->bdev)
3697                         continue;
3698                 if (!dev->in_fs_metadata || !dev->writeable)
3699                         continue;
3700 
3701                 ret = write_dev_supers(dev, sb, do_barriers, 1, max_mirrors);
3702                 if (ret)
3703                         total_errors++;
3704         }
3705         mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
3706         if (total_errors > max_errors) {
3707                 btrfs_std_error(root->fs_info, -EIO,
3708                             "%d errors while writing supers", total_errors);
3709                 return -EIO;
3710         }
3711         return 0;
3712 }
3713 
3714 int write_ctree_super(struct btrfs_trans_handle *trans,
3715                       struct btrfs_root *root, int max_mirrors)
3716 {
3717         return write_all_supers(root, max_mirrors);
3718 }
3719 
3720 /* Drop a fs root from the radix tree and free it. */
3721 void btrfs_drop_and_free_fs_root(struct btrfs_fs_info *fs_info,
3722                                   struct btrfs_root *root)
3723 {
3724         spin_lock(&fs_info->fs_roots_radix_lock);
3725         radix_tree_delete(&fs_info->fs_roots_radix,
3726                           (unsigned long)root->root_key.objectid);
3727         spin_unlock(&fs_info->fs_roots_radix_lock);
3728 
3729         if (btrfs_root_refs(&root->root_item) == 0)
3730                 synchronize_srcu(&fs_info->subvol_srcu);
3731 
3732         if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state))
3733                 btrfs_free_log(NULL, root);
3734 
3735         if (root->free_ino_pinned)
3736                 __btrfs_remove_free_space_cache(root->free_ino_pinned);
3737         if (root->free_ino_ctl)
3738                 __btrfs_remove_free_space_cache(root->free_ino_ctl);
3739         free_fs_root(root);
3740 }
3741 
3742 static void free_fs_root(struct btrfs_root *root)
3743 {
3744         iput(root->ino_cache_inode);
3745         WARN_ON(!RB_EMPTY_ROOT(&root->inode_tree));
3746         btrfs_free_block_rsv(root, root->orphan_block_rsv);
3747         root->orphan_block_rsv = NULL;
3748         if (root->anon_dev)
3749                 free_anon_bdev(root->anon_dev);
3750         if (root->subv_writers)
3751                 btrfs_free_subvolume_writers(root->subv_writers);
3752         free_extent_buffer(root->node);
3753         free_extent_buffer(root->commit_root);
3754         kfree(root->free_ino_ctl);
3755         kfree(root->free_ino_pinned);
3756         kfree(root->name);
3757         btrfs_put_fs_root(root);
3758 }
3759 
3760 void btrfs_free_fs_root(struct btrfs_root *root)
3761 {
3762         free_fs_root(root);
3763 }
3764 
3765 int btrfs_cleanup_fs_roots(struct btrfs_fs_info *fs_info)
3766 {
3767         u64 root_objectid = 0;
3768         struct btrfs_root *gang[8];
3769         int i = 0;
3770         int err = 0;
3771         unsigned int ret = 0;
3772         int index;
3773 
3774         while (1) {
3775                 index = srcu_read_lock(&fs_info->subvol_srcu);
3776                 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
3777                                              (void **)gang, root_objectid,
3778                                              ARRAY_SIZE(gang));
3779                 if (!ret) {
3780                         srcu_read_unlock(&fs_info->subvol_srcu, index);
3781                         break;
3782                 }
3783                 root_objectid = gang[ret - 1]->root_key.objectid + 1;
3784 
3785                 for (i = 0; i < ret; i++) {
3786                         /* Avoid to grab roots in dead_roots */
3787                         if (btrfs_root_refs(&gang[i]->root_item) == 0) {
3788                                 gang[i] = NULL;
3789                                 continue;
3790                         }
3791                         /* grab all the search result for later use */
3792                         gang[i] = btrfs_grab_fs_root(gang[i]);
3793                 }
3794                 srcu_read_unlock(&fs_info->subvol_srcu, index);
3795 
3796                 for (i = 0; i < ret; i++) {
3797                         if (!gang[i])
3798                                 continue;
3799                         root_objectid = gang[i]->root_key.objectid;
3800                         err = btrfs_orphan_cleanup(gang[i]);
3801                         if (err)
3802                                 break;
3803                         btrfs_put_fs_root(gang[i]);
3804                 }
3805                 root_objectid++;
3806         }
3807 
3808         /* release the uncleaned roots due to error */
3809         for (; i < ret; i++) {
3810                 if (gang[i])
3811                         btrfs_put_fs_root(gang[i]);
3812         }
3813         return err;
3814 }
3815 
3816 int btrfs_commit_super(struct btrfs_root *root)
3817 {
3818         struct btrfs_trans_handle *trans;
3819 
3820         mutex_lock(&root->fs_info->cleaner_mutex);
3821         btrfs_run_delayed_iputs(root);
3822         mutex_unlock(&root->fs_info->cleaner_mutex);
3823         wake_up_process(root->fs_info->cleaner_kthread);
3824 
3825         /* wait until ongoing cleanup work done */
3826         down_write(&root->fs_info->cleanup_work_sem);
3827         up_write(&root->fs_info->cleanup_work_sem);
3828 
3829         trans = btrfs_join_transaction(root);
3830         if (IS_ERR(trans))
3831                 return PTR_ERR(trans);
3832         return btrfs_commit_transaction(trans, root);
3833 }
3834 
3835 void close_ctree(struct btrfs_root *root)
3836 {
3837         struct btrfs_fs_info *fs_info = root->fs_info;
3838         int ret;
3839 
3840         fs_info->closing = 1;
3841         smp_mb();
3842 
3843         /* wait for the qgroup rescan worker to stop */
3844         btrfs_qgroup_wait_for_completion(fs_info);
3845 
3846         /* wait for the uuid_scan task to finish */
3847         down(&fs_info->uuid_tree_rescan_sem);
3848         /* avoid complains from lockdep et al., set sem back to initial state */
3849         up(&fs_info->uuid_tree_rescan_sem);
3850 
3851         /* pause restriper - we want to resume on mount */
3852         btrfs_pause_balance(fs_info);
3853 
3854         btrfs_dev_replace_suspend_for_unmount(fs_info);
3855 
3856         btrfs_scrub_cancel(fs_info);
3857 
3858         /* wait for any defraggers to finish */
3859         wait_event(fs_info->transaction_wait,
3860                    (atomic_read(&fs_info->defrag_running) == 0));
3861 
3862         /* clear out the rbtree of defraggable inodes */
3863         btrfs_cleanup_defrag_inodes(fs_info);
3864 
3865         cancel_work_sync(&fs_info->async_reclaim_work);
3866 
3867         if (!(fs_info->sb->s_flags & MS_RDONLY)) {
3868                 /*
3869                  * If the cleaner thread is stopped and there are
3870                  * block groups queued for removal, the deletion will be
3871                  * skipped when we quit the cleaner thread.
3872                  */
3873                 btrfs_delete_unused_bgs(root->fs_info);
3874 
3875                 ret = btrfs_commit_super(root);
3876                 if (ret)
3877                         btrfs_err(fs_info, "commit super ret %d", ret);
3878         }
3879 
3880         if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state))
3881                 btrfs_error_commit_super(root);
3882 
3883         kthread_stop(fs_info->transaction_kthread);
3884         kthread_stop(fs_info->cleaner_kthread);
3885 
3886         fs_info->closing = 2;
3887         smp_mb();
3888 
3889         btrfs_free_qgroup_config(fs_info);
3890 
3891         if (percpu_counter_sum(&fs_info->delalloc_bytes)) {
3892                 btrfs_info(fs_info, "at unmount delalloc count %lld",
3893                        percpu_counter_sum(&fs_info->delalloc_bytes));
3894         }
3895 
3896         btrfs_sysfs_remove_mounted(fs_info);
3897         btrfs_sysfs_remove_fsid(fs_info->fs_devices);
3898 
3899         btrfs_free_fs_roots(fs_info);
3900 
3901         btrfs_put_block_group_cache(fs_info);
3902 
3903         btrfs_free_block_groups(fs_info);
3904 
3905         /*
3906          * we must make sure there is not any read request to
3907          * submit after we stopping all workers.
3908          */
3909         invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
3910         btrfs_stop_all_workers(fs_info);
3911 
3912         fs_info->open = 0;
3913         free_root_pointers(fs_info, 1);
3914 
3915         iput(fs_info->btree_inode);
3916 
3917 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
3918         if (btrfs_test_opt(root, CHECK_INTEGRITY))
3919                 btrfsic_unmount(root, fs_info->fs_devices);
3920 #endif
3921 
3922         btrfs_close_devices(fs_info->fs_devices);
3923         btrfs_mapping_tree_free(&fs_info->mapping_tree);
3924 
3925         percpu_counter_destroy(&fs_info->dirty_metadata_bytes);
3926         percpu_counter_destroy(&fs_info->delalloc_bytes);
3927         percpu_counter_destroy(&fs_info->bio_counter);
3928         bdi_destroy(&fs_info->bdi);
3929         cleanup_srcu_struct(&fs_info->subvol_srcu);
3930 
3931         btrfs_free_stripe_hash_table(fs_info);
3932 
3933         __btrfs_free_block_rsv(root->orphan_block_rsv);
3934         root->orphan_block_rsv = NULL;
3935 
3936         lock_chunks(root);
3937         while (!list_empty(&fs_info->pinned_chunks)) {
3938                 struct extent_map *em;
3939 
3940                 em = list_first_entry(&fs_info->pinned_chunks,
3941                                       struct extent_map, list);
3942                 list_del_init(&em->list);
3943                 free_extent_map(em);
3944         }
3945         unlock_chunks(root);
3946 }
3947 
3948 int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid,
3949                           int atomic)
3950 {
3951         int ret;
3952         struct inode *btree_inode = buf->pages[0]->mapping->host;
3953 
3954         ret = extent_buffer_uptodate(buf);
3955         if (!ret)
3956                 return ret;
3957 
3958         ret = verify_parent_transid(&BTRFS_I(btree_inode)->io_tree, buf,
3959                                     parent_transid, atomic);
3960         if (ret == -EAGAIN)
3961                 return ret;
3962         return !ret;
3963 }
3964 
3965 void btrfs_mark_buffer_dirty(struct extent_buffer *buf)
3966 {
3967         struct btrfs_root *root;
3968         u64 transid = btrfs_header_generation(buf);
3969         int was_dirty;
3970 
3971 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
3972         /*
3973          * This is a fast path so only do this check if we have sanity tests
3974          * enabled.  Normal people shouldn't be marking dummy buffers as dirty
3975          * outside of the sanity tests.
3976          */
3977         if (unlikely(test_bit(EXTENT_BUFFER_DUMMY, &buf->bflags)))
3978                 return;
3979 #endif
3980         root = BTRFS_I(buf->pages[0]->mapping->host)->root;
3981         btrfs_assert_tree_locked(buf);
3982         if (transid != root->fs_info->generation)
3983                 WARN(1, KERN_CRIT "btrfs transid mismatch buffer %llu, "
3984                        "found %llu running %llu\n",
3985                         buf->start, transid, root->fs_info->generation);
3986         was_dirty = set_extent_buffer_dirty(buf);
3987         if (!was_dirty)
3988                 __percpu_counter_add(&root->fs_info->dirty_metadata_bytes,
3989                                      buf->len,
3990                                      root->fs_info->dirty_metadata_batch);
3991 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
3992         if (btrfs_header_level(buf) == 0 && check_leaf(root, buf)) {
3993                 btrfs_print_leaf(root, buf);
3994                 ASSERT(0);
3995         }
3996 #endif
3997 }
3998 
3999 static void __btrfs_btree_balance_dirty(struct btrfs_root *root,
4000                                         int flush_delayed)
4001 {
4002         /*
4003          * looks as though older kernels can get into trouble with
4004          * this code, they end up stuck in balance_dirty_pages forever
4005          */
4006         int ret;
4007 
4008         if (current->flags & PF_MEMALLOC)
4009                 return;
4010 
4011         if (flush_delayed)
4012                 btrfs_balance_delayed_items(root);
4013 
4014         ret = percpu_counter_compare(&root->fs_info->dirty_metadata_bytes,
4015                                      BTRFS_DIRTY_METADATA_THRESH);
4016         if (ret > 0) {
4017                 balance_dirty_pages_ratelimited(
4018                                    root->fs_info->btree_inode->i_mapping);
4019         }
4020 }
4021 
4022 void btrfs_btree_balance_dirty(struct btrfs_root *root)
4023 {
4024         __btrfs_btree_balance_dirty(root, 1);
4025 }
4026 
4027 void btrfs_btree_balance_dirty_nodelay(struct btrfs_root *root)
4028 {
4029         __btrfs_btree_balance_dirty(root, 0);
4030 }
4031 
4032 int btrfs_read_buffer(struct extent_buffer *buf, u64 parent_transid)
4033 {
4034         struct btrfs_root *root = BTRFS_I(buf->pages[0]->mapping->host)->root;
4035         return btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
4036 }
4037 
4038 static int btrfs_check_super_valid(struct btrfs_fs_info *fs_info,
4039                               int read_only)
4040 {
4041         struct btrfs_super_block *sb = fs_info->super_copy;
4042         u64 nodesize = btrfs_super_nodesize(sb);
4043         u64 sectorsize = btrfs_super_sectorsize(sb);
4044         int ret = 0;
4045 
4046         if (btrfs_super_magic(sb) != BTRFS_MAGIC) {
4047                 printk(KERN_ERR "BTRFS: no valid FS found\n");
4048                 ret = -EINVAL;
4049         }
4050         if (btrfs_super_flags(sb) & ~BTRFS_SUPER_FLAG_SUPP)
4051                 printk(KERN_WARNING "BTRFS: unrecognized super flag: %llu\n",
4052                                 btrfs_super_flags(sb) & ~BTRFS_SUPER_FLAG_SUPP);
4053         if (btrfs_super_root_level(sb) >= BTRFS_MAX_LEVEL) {
4054                 printk(KERN_ERR "BTRFS: tree_root level too big: %d >= %d\n",
4055                                 btrfs_super_root_level(sb), BTRFS_MAX_LEVEL);
4056                 ret = -EINVAL;
4057         }
4058         if (btrfs_super_chunk_root_level(sb) >= BTRFS_MAX_LEVEL) {
4059                 printk(KERN_ERR "BTRFS: chunk_root level too big: %d >= %d\n",
4060                                 btrfs_super_chunk_root_level(sb), BTRFS_MAX_LEVEL);
4061                 ret = -EINVAL;
4062         }
4063         if (btrfs_super_log_root_level(sb) >= BTRFS_MAX_LEVEL) {
4064                 printk(KERN_ERR "BTRFS: log_root level too big: %d >= %d\n",
4065                                 btrfs_super_log_root_level(sb), BTRFS_MAX_LEVEL);
4066                 ret = -EINVAL;
4067         }
4068 
4069         /*
4070          * Check sectorsize and nodesize first, other check will need it.
4071          * Check all possible sectorsize(4K, 8K, 16K, 32K, 64K) here.
4072          */
4073         if (!is_power_of_2(sectorsize) || sectorsize < 4096 ||
4074             sectorsize > BTRFS_MAX_METADATA_BLOCKSIZE) {
4075                 printk(KERN_ERR "BTRFS: invalid sectorsize %llu\n", sectorsize);
4076                 ret = -EINVAL;
4077         }
4078         /* Only PAGE SIZE is supported yet */
4079         if (sectorsize != PAGE_SIZE) {
4080                 printk(KERN_ERR "BTRFS: sectorsize %llu not supported yet, only support %lu\n",
4081                                 sectorsize, PAGE_SIZE);
4082                 ret = -EINVAL;
4083         }
4084         if (!is_power_of_2(nodesize) || nodesize < sectorsize ||
4085             nodesize > BTRFS_MAX_METADATA_BLOCKSIZE) {
4086                 printk(KERN_ERR "BTRFS: invalid nodesize %llu\n", nodesize);
4087                 ret = -EINVAL;
4088         }
4089         if (nodesize != le32_to_cpu(sb->__unused_leafsize)) {
4090                 printk(KERN_ERR "BTRFS: invalid leafsize %u, should be %llu\n",
4091                                 le32_to_cpu(sb->__unused_leafsize),
4092                                 nodesize);
4093                 ret = -EINVAL;
4094         }
4095 
4096         /* Root alignment check */
4097         if (!IS_ALIGNED(btrfs_super_root(sb), sectorsize)) {
4098                 printk(KERN_WARNING "BTRFS: tree_root block unaligned: %llu\n",
4099                                 btrfs_super_root(sb));
4100                 ret = -EINVAL;
4101         }
4102         if (!IS_ALIGNED(btrfs_super_chunk_root(sb), sectorsize)) {
4103                 printk(KERN_WARNING "BTRFS: chunk_root block unaligned: %llu\n",
4104                                 btrfs_super_chunk_root(sb));
4105                 ret = -EINVAL;
4106         }
4107         if (!IS_ALIGNED(btrfs_super_log_root(sb), sectorsize)) {
4108                 printk(KERN_WARNING "BTRFS: log_root block unaligned: %llu\n",
4109                                 btrfs_super_log_root(sb));
4110                 ret = -EINVAL;
4111         }
4112 
4113         if (memcmp(fs_info->fsid, sb->dev_item.fsid, BTRFS_UUID_SIZE) != 0) {
4114                 printk(KERN_ERR "BTRFS: dev_item UUID does not match fsid: %pU != %pU\n",
4115                                 fs_info->fsid, sb->dev_item.fsid);
4116                 ret = -EINVAL;
4117         }
4118 
4119         /*
4120          * Hint to catch really bogus numbers, bitflips or so, more exact checks are
4121          * done later
4122          */
4123         if (btrfs_super_num_devices(sb) > (1UL << 31))
4124                 printk(KERN_WARNING "BTRFS: suspicious number of devices: %llu\n",
4125                                 btrfs_super_num_devices(sb));
4126         if (btrfs_super_num_devices(sb) == 0) {
4127                 printk(KERN_ERR "BTRFS: number of devices is 0\n");
4128                 ret = -EINVAL;
4129         }
4130 
4131         if (btrfs_super_bytenr(sb) != BTRFS_SUPER_INFO_OFFSET) {
4132                 printk(KERN_ERR "BTRFS: super offset mismatch %llu != %u\n",
4133                                 btrfs_super_bytenr(sb), BTRFS_SUPER_INFO_OFFSET);
4134                 ret = -EINVAL;
4135         }
4136 
4137         /*
4138          * Obvious sys_chunk_array corruptions, it must hold at least one key
4139          * and one chunk
4140          */
4141         if (btrfs_super_sys_array_size(sb) > BTRFS_SYSTEM_CHUNK_ARRAY_SIZE) {
4142                 printk(KERN_ERR "BTRFS: system chunk array too big %u > %u\n",
4143                                 btrfs_super_sys_array_size(sb),
4144                                 BTRFS_SYSTEM_CHUNK_ARRAY_SIZE);
4145                 ret = -EINVAL;
4146         }
4147         if (btrfs_super_sys_array_size(sb) < sizeof(struct btrfs_disk_key)
4148                         + sizeof(struct btrfs_chunk)) {
4149                 printk(KERN_ERR "BTRFS: system chunk array too small %u < %zu\n",
4150                                 btrfs_super_sys_array_size(sb),
4151                                 sizeof(struct btrfs_disk_key)
4152                                 + sizeof(struct btrfs_chunk));
4153                 ret = -EINVAL;
4154         }
4155 
4156         /*
4157          * The generation is a global counter, we'll trust it more than the others
4158          * but it's still possible that it's the one that's wrong.
4159          */
4160         if (btrfs_super_generation(sb) < btrfs_super_chunk_root_generation(sb))
4161                 printk(KERN_WARNING
4162                         "BTRFS: suspicious: generation < chunk_root_generation: %llu < %llu\n",
4163                         btrfs_super_generation(sb), btrfs_super_chunk_root_generation(sb));
4164         if (btrfs_super_generation(sb) < btrfs_super_cache_generation(sb)
4165             && btrfs_super_cache_generation(sb) != (u64)-1)
4166                 printk(KERN_WARNING
4167                         "BTRFS: suspicious: generation < cache_generation: %llu < %llu\n",
4168                         btrfs_super_generation(sb), btrfs_super_cache_generation(sb));
4169 
4170         return ret;
4171 }
4172 
4173 static void btrfs_error_commit_super(struct btrfs_root *root)
4174 {
4175         mutex_lock(&root->fs_info->cleaner_mutex);
4176         btrfs_run_delayed_iputs(root);
4177         mutex_unlock(&root->fs_info->cleaner_mutex);
4178 
4179         down_write(&root->fs_info->cleanup_work_sem);
4180         up_write(&root->fs_info->cleanup_work_sem);
4181 
4182         /* cleanup FS via transaction */
4183         btrfs_cleanup_transaction(root);
4184 }
4185 
4186 static void btrfs_destroy_ordered_extents(struct btrfs_root *root)
4187 {
4188         struct btrfs_ordered_extent *ordered;
4189 
4190         spin_lock(&root->ordered_extent_lock);
4191         /*
4192          * This will just short circuit the ordered completion stuff which will
4193          * make sure the ordered extent gets properly cleaned up.
4194          */
4195         list_for_each_entry(ordered, &root->ordered_extents,
4196                             root_extent_list)
4197                 set_bit(BTRFS_ORDERED_IOERR, &ordered->flags);
4198         spin_unlock(&root->ordered_extent_lock);
4199 }
4200 
4201 static void btrfs_destroy_all_ordered_extents(struct btrfs_fs_info *fs_info)
4202 {
4203         struct btrfs_root *root;
4204         struct list_head splice;
4205 
4206         INIT_LIST_HEAD(&splice);
4207 
4208         spin_lock(&fs_info->ordered_root_lock);
4209         list_splice_init(&fs_info->ordered_roots, &splice);
4210         while (!list_empty(&splice)) {
4211                 root = list_first_entry(&splice, struct btrfs_root,
4212                                         ordered_root);
4213                 list_move_tail(&root->ordered_root,
4214                                &fs_info->ordered_roots);
4215 
4216                 spin_unlock(&fs_info->ordered_root_lock);
4217                 btrfs_destroy_ordered_extents(root);
4218 
4219                 cond_resched();
4220                 spin_lock(&fs_info->ordered_root_lock);
4221         }
4222         spin_unlock(&fs_info->ordered_root_lock);
4223 }
4224 
4225 static int btrfs_destroy_delayed_refs(struct btrfs_transaction *trans,
4226                                       struct btrfs_root *root)
4227 {
4228         struct rb_node *node;
4229         struct btrfs_delayed_ref_root *delayed_refs;
4230         struct btrfs_delayed_ref_node *ref;
4231         int ret = 0;
4232 
4233         delayed_refs = &trans->delayed_refs;
4234 
4235         spin_lock(&delayed_refs->lock);
4236         if (atomic_read(&delayed_refs->num_entries) == 0) {
4237                 spin_unlock(&delayed_refs->lock);
4238                 btrfs_info(root->fs_info, "delayed_refs has NO entry");
4239                 return ret;
4240         }
4241 
4242         while ((node = rb_first(&delayed_refs->href_root)) != NULL) {
4243                 struct btrfs_delayed_ref_head *head;
4244                 struct btrfs_delayed_ref_node *tmp;
4245                 bool pin_bytes = false;
4246 
4247                 head = rb_entry(node, struct btrfs_delayed_ref_head,
4248                                 href_node);
4249                 if (!mutex_trylock(&head->mutex)) {
4250                         atomic_inc(&head->node.refs);
4251                         spin_unlock(&delayed_refs->lock);
4252 
4253                         mutex_lock(&head->mutex);
4254                         mutex_unlock(&head->mutex);
4255                         btrfs_put_delayed_ref(&head->node);
4256                         spin_lock(&delayed_refs->lock);
4257                         continue;
4258                 }
4259                 spin_lock(&head->lock);
4260                 list_for_each_entry_safe_reverse(ref, tmp, &head->ref_list,
4261                                                  list) {
4262                         ref->in_tree = 0;
4263                         list_del(&ref->list);
4264                         atomic_dec(&delayed_refs->num_entries);
4265                         btrfs_put_delayed_ref(ref);
4266                 }
4267                 if (head->must_insert_reserved)
4268                         pin_bytes = true;
4269                 btrfs_free_delayed_extent_op(head->extent_op);
4270                 delayed_refs->num_heads--;
4271                 if (head->processing == 0)
4272                         delayed_refs->num_heads_ready--;
4273                 atomic_dec(&delayed_refs->num_entries);
4274                 head->node.in_tree = 0;
4275                 rb_erase(&head->href_node, &delayed_refs->href_root);
4276                 spin_unlock(&head->lock);
4277                 spin_unlock(&delayed_refs->lock);
4278                 mutex_unlock(&head->mutex);
4279 
4280                 if (pin_bytes)
4281                         btrfs_pin_extent(root, head->node.bytenr,
4282                                          head->node.num_bytes, 1);
4283                 btrfs_put_delayed_ref(&head->node);
4284                 cond_resched();
4285                 spin_lock(&delayed_refs->lock);
4286         }
4287 
4288         spin_unlock(&delayed_refs->lock);
4289 
4290         return ret;
4291 }
4292 
4293 static void btrfs_destroy_delalloc_inodes(struct btrfs_root *root)
4294 {
4295         struct btrfs_inode *btrfs_inode;
4296         struct list_head splice;
4297 
4298         INIT_LIST_HEAD(&splice);
4299 
4300         spin_lock(&root->delalloc_lock);
4301         list_splice_init(&root->delalloc_inodes, &splice);
4302 
4303         while (!list_empty(&splice)) {
4304                 btrfs_inode = list_first_entry(&splice, struct btrfs_inode,
4305                                                delalloc_inodes);
4306 
4307                 list_del_init(&btrfs_inode->delalloc_inodes);
4308                 clear_bit(BTRFS_INODE_IN_DELALLOC_LIST,
4309                           &btrfs_inode->runtime_flags);
4310                 spin_unlock(&root->delalloc_lock);
4311 
4312                 btrfs_invalidate_inodes(btrfs_inode->root);
4313 
4314                 spin_lock(&root->delalloc_lock);
4315         }
4316 
4317         spin_unlock(&root->delalloc_lock);
4318 }
4319 
4320 static void btrfs_destroy_all_delalloc_inodes(struct btrfs_fs_info *fs_info)
4321 {
4322         struct btrfs_root *root;
4323         struct list_head splice;
4324 
4325         INIT_LIST_HEAD(&splice);
4326 
4327         spin_lock(&fs_info->delalloc_root_lock);
4328         list_splice_init(&fs_info->delalloc_roots, &splice);
4329         while (!list_empty(&splice)) {
4330                 root = list_first_entry(&splice, struct btrfs_root,
4331                                          delalloc_root);
4332                 list_del_init(&root->delalloc_root);
4333                 root = btrfs_grab_fs_root(root);
4334                 BUG_ON(!root);
4335                 spin_unlock(&fs_info->delalloc_root_lock);
4336 
4337                 btrfs_destroy_delalloc_inodes(root);
4338                 btrfs_put_fs_root(root);
4339 
4340                 spin_lock(&fs_info->delalloc_root_lock);
4341         }
4342         spin_unlock(&fs_info->delalloc_root_lock);
4343 }
4344 
4345 static int btrfs_destroy_marked_extents(struct btrfs_root *root,
4346                                         struct extent_io_tree *dirty_pages,
4347                                         int mark)
4348 {
4349         int ret;
4350         struct extent_buffer *eb;
4351         u64 start = 0;
4352         u64 end;
4353 
4354         while (1) {
4355                 ret = find_first_extent_bit(dirty_pages, start, &start, &end,
4356                                             mark, NULL);
4357                 if (ret)
4358                         break;
4359 
4360                 clear_extent_bits(dirty_pages, start, end, mark, GFP_NOFS);
4361                 while (start <= end) {
4362                         eb = btrfs_find_tree_block(root->fs_info, start);
4363                         start += root->nodesize;
4364                         if (!eb)
4365                                 continue;
4366                         wait_on_extent_buffer_writeback(eb);
4367 
4368                         if (test_and_clear_bit(EXTENT_BUFFER_DIRTY,
4369                                                &eb->bflags))
4370                                 clear_extent_buffer_dirty(eb);
4371                         free_extent_buffer_stale(eb);
4372                 }
4373         }
4374 
4375         return ret;
4376 }
4377 
4378 static int btrfs_destroy_pinned_extent(struct btrfs_root *root,
4379                                        struct extent_io_tree *pinned_extents)
4380 {
4381         struct extent_io_tree *unpin;
4382         u64 start;
4383         u64 end;
4384         int ret;
4385         bool loop = true;
4386 
4387         unpin = pinned_extents;
4388 again:
4389         while (1) {
4390                 ret = find_first_extent_bit(unpin, 0, &start, &end,
4391                                             EXTENT_DIRTY, NULL);
4392                 if (ret)
4393                         break;
4394 
4395                 clear_extent_dirty(unpin, start, end, GFP_NOFS);
4396                 btrfs_error_unpin_extent_range(root, start, end);
4397                 cond_resched();
4398         }
4399 
4400         if (loop) {
4401                 if (unpin == &root->fs_info->freed_extents[0])
4402                         unpin = &root->fs_info->freed_extents[1];
4403                 else
4404                         unpin = &root->fs_info->freed_extents[0];
4405                 loop = false;
4406                 goto again;
4407         }
4408 
4409         return 0;
4410 }
4411 
4412 void btrfs_cleanup_one_transaction(struct btrfs_transaction *cur_trans,
4413                                    struct btrfs_root *root)
4414 {
4415         btrfs_destroy_delayed_refs(cur_trans, root);
4416 
4417         cur_trans->state = TRANS_STATE_COMMIT_START;
4418         wake_up(&root->fs_info->transaction_blocked_wait);
4419 
4420         cur_trans->state = TRANS_STATE_UNBLOCKED;
4421         wake_up(&root->fs_info->transaction_wait);
4422 
4423         btrfs_destroy_delayed_inodes(root);
4424         btrfs_assert_delayed_root_empty(root);
4425 
4426         btrfs_destroy_marked_extents(root, &cur_trans->dirty_pages,
4427                                      EXTENT_DIRTY);
4428         btrfs_destroy_pinned_extent(root,
4429                                     root->fs_info->pinned_extents);
4430 
4431         cur_trans->state =TRANS_STATE_COMPLETED;
4432         wake_up(&cur_trans->commit_wait);
4433 
4434         /*
4435         memset(cur_trans, 0, sizeof(*cur_trans));
4436         kmem_cache_free(btrfs_transaction_cachep, cur_trans);
4437         */
4438 }
4439 
4440 static int btrfs_cleanup_transaction(struct btrfs_root *root)
4441 {
4442         struct btrfs_transaction *t;
4443 
4444         mutex_lock(&root->fs_info->transaction_kthread_mutex);
4445 
4446         spin_lock(&root->fs_info->trans_lock);
4447         while (!list_empty(&root->fs_info->trans_list)) {
4448                 t = list_first_entry(&root->fs_info->trans_list,
4449                                      struct btrfs_transaction, list);
4450                 if (t->state >= TRANS_STATE_COMMIT_START) {
4451                         atomic_inc(&t->use_count);
4452                         spin_unlock(&root->fs_info->trans_lock);
4453                         btrfs_wait_for_commit(root, t->transid);
4454                         btrfs_put_transaction(t);
4455                         spin_lock(&root->fs_info->trans_lock);
4456                         continue;
4457                 }
4458                 if (t == root->fs_info->running_transaction) {
4459                         t->state = TRANS_STATE_COMMIT_DOING;
4460                         spin_unlock(&root->fs_info->trans_lock);
4461                         /*
4462                          * We wait for 0 num_writers since we don't hold a trans
4463                          * handle open currently for this transaction.
4464                          */
4465                         wait_event(t->writer_wait,
4466                                    atomic_read(&t->num_writers) == 0);
4467                 } else {
4468                         spin_unlock(&root->fs_info->trans_lock);
4469                 }
4470                 btrfs_cleanup_one_transaction(t, root);
4471 
4472                 spin_lock(&root->fs_info->trans_lock);
4473                 if (t == root->fs_info->running_transaction)
4474                         root->fs_info->running_transaction = NULL;
4475                 list_del_init(&t->list);
4476                 spin_unlock(&root->fs_info->trans_lock);
4477 
4478                 btrfs_put_transaction(t);
4479                 trace_btrfs_transaction_commit(root);
4480                 spin_lock(&root->fs_info->trans_lock);
4481         }
4482         spin_unlock(&root->fs_info->trans_lock);
4483         btrfs_destroy_all_ordered_extents(root->fs_info);
4484         btrfs_destroy_delayed_inodes(root);
4485         btrfs_assert_delayed_root_empty(root);
4486         btrfs_destroy_pinned_extent(root, root->fs_info->pinned_extents);
4487         btrfs_destroy_all_delalloc_inodes(root->fs_info);
4488         mutex_unlock(&root->fs_info->transaction_kthread_mutex);
4489 
4490         return 0;
4491 }
4492 
4493 static const struct extent_io_ops btree_extent_io_ops = {
4494         .readpage_end_io_hook = btree_readpage_end_io_hook,
4495         .readpage_io_failed_hook = btree_io_failed_hook,
4496         .submit_bio_hook = btree_submit_bio_hook,
4497         /* note we're sharing with inode.c for the merge bio hook */
4498         .merge_bio_hook = btrfs_merge_bio_hook,
4499 };
4500 

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