1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright (C) 2007 Oracle. All rights reserved.
7 #include <linux/slab.h>
8 #include <linux/sched.h>
9 #include <linux/writeback.h>
10 #include <linux/pagemap.h>
11 #include <linux/blkdev.h>
12 #include <linux/uuid.h>
16 #include "transaction.h"
19 #include "inode-map.h"
21 #include "dev-replace.h"
23 #include "block-group.h"
25 #define BTRFS_ROOT_TRANS_TAG 0
28 * Transaction states and transitions
30 * No running transaction (fs tree blocks are not modified)
33 * | Call start_transaction() variants. Except btrfs_join_transaction_nostart().
35 * Transaction N [[TRANS_STATE_RUNNING]]
37 * | New trans handles can be attached to transaction N by calling all
38 * | start_transaction() variants.
41 * | Call btrfs_commit_transaction() on any trans handle attached to
44 * Transaction N [[TRANS_STATE_COMMIT_START]]
46 * | Will wait for previous running transaction to completely finish if there
49 * | Then one of the following happes:
50 * | - Wait for all other trans handle holders to release.
51 * | The btrfs_commit_transaction() caller will do the commit work.
52 * | - Wait for current transaction to be committed by others.
53 * | Other btrfs_commit_transaction() caller will do the commit work.
55 * | At this stage, only btrfs_join_transaction*() variants can attach
56 * | to this running transaction.
57 * | All other variants will wait for current one to finish and attach to
61 * | Caller is chosen to commit transaction N, and all other trans handle
62 * | haven been released.
64 * Transaction N [[TRANS_STATE_COMMIT_DOING]]
66 * | The heavy lifting transaction work is started.
67 * | From running delayed refs (modifying extent tree) to creating pending
68 * | snapshots, running qgroups.
69 * | In short, modify supporting trees to reflect modifications of subvolume
72 * | At this stage, all start_transaction() calls will wait for this
73 * | transaction to finish and attach to transaction N+1.
76 * | Until all supporting trees are updated.
78 * Transaction N [[TRANS_STATE_UNBLOCKED]]
80 * | All needed trees are modified, thus we only [[TRANS_STATE_RUNNING]]
81 * | need to write them back to disk and update |
84 * | At this stage, new transaction is allowed to |
86 * | All new start_transaction() calls will be |
87 * | attached to transid N+1. |
90 * | Until all tree blocks are super blocks are |
91 * | written to block devices |
93 * Transaction N [[TRANS_STATE_COMPLETED]] V
94 * All tree blocks and super blocks are written. Transaction N+1
95 * This transaction is finished and all its [[TRANS_STATE_COMMIT_START]]
96 * data structures will be cleaned up. | Life goes on
98 static const unsigned int btrfs_blocked_trans_types
[TRANS_STATE_MAX
] = {
99 [TRANS_STATE_RUNNING
] = 0U,
100 [TRANS_STATE_COMMIT_START
] = (__TRANS_START
| __TRANS_ATTACH
),
101 [TRANS_STATE_COMMIT_DOING
] = (__TRANS_START
|
104 __TRANS_JOIN_NOSTART
),
105 [TRANS_STATE_UNBLOCKED
] = (__TRANS_START
|
108 __TRANS_JOIN_NOLOCK
|
109 __TRANS_JOIN_NOSTART
),
110 [TRANS_STATE_COMPLETED
] = (__TRANS_START
|
113 __TRANS_JOIN_NOLOCK
|
114 __TRANS_JOIN_NOSTART
),
117 void btrfs_put_transaction(struct btrfs_transaction
*transaction
)
119 WARN_ON(refcount_read(&transaction
->use_count
) == 0);
120 if (refcount_dec_and_test(&transaction
->use_count
)) {
121 BUG_ON(!list_empty(&transaction
->list
));
122 WARN_ON(!RB_EMPTY_ROOT(
123 &transaction
->delayed_refs
.href_root
.rb_root
));
124 WARN_ON(!RB_EMPTY_ROOT(
125 &transaction
->delayed_refs
.dirty_extent_root
));
126 if (transaction
->delayed_refs
.pending_csums
)
127 btrfs_err(transaction
->fs_info
,
128 "pending csums is %llu",
129 transaction
->delayed_refs
.pending_csums
);
131 * If any block groups are found in ->deleted_bgs then it's
132 * because the transaction was aborted and a commit did not
133 * happen (things failed before writing the new superblock
134 * and calling btrfs_finish_extent_commit()), so we can not
135 * discard the physical locations of the block groups.
137 while (!list_empty(&transaction
->deleted_bgs
)) {
138 struct btrfs_block_group
*cache
;
140 cache
= list_first_entry(&transaction
->deleted_bgs
,
141 struct btrfs_block_group
,
143 list_del_init(&cache
->bg_list
);
144 btrfs_put_block_group_trimming(cache
);
145 btrfs_put_block_group(cache
);
147 WARN_ON(!list_empty(&transaction
->dev_update_list
));
152 static noinline
void switch_commit_roots(struct btrfs_trans_handle
*trans
)
154 struct btrfs_transaction
*cur_trans
= trans
->transaction
;
155 struct btrfs_fs_info
*fs_info
= trans
->fs_info
;
156 struct btrfs_root
*root
, *tmp
;
158 down_write(&fs_info
->commit_root_sem
);
159 list_for_each_entry_safe(root
, tmp
, &cur_trans
->switch_commits
,
161 list_del_init(&root
->dirty_list
);
162 free_extent_buffer(root
->commit_root
);
163 root
->commit_root
= btrfs_root_node(root
);
164 if (is_fstree(root
->root_key
.objectid
))
165 btrfs_unpin_free_ino(root
);
166 extent_io_tree_release(&root
->dirty_log_pages
);
167 btrfs_qgroup_clean_swapped_blocks(root
);
170 /* We can free old roots now. */
171 spin_lock(&cur_trans
->dropped_roots_lock
);
172 while (!list_empty(&cur_trans
->dropped_roots
)) {
173 root
= list_first_entry(&cur_trans
->dropped_roots
,
174 struct btrfs_root
, root_list
);
175 list_del_init(&root
->root_list
);
176 spin_unlock(&cur_trans
->dropped_roots_lock
);
177 btrfs_free_log(trans
, root
);
178 btrfs_drop_and_free_fs_root(fs_info
, root
);
179 spin_lock(&cur_trans
->dropped_roots_lock
);
181 spin_unlock(&cur_trans
->dropped_roots_lock
);
182 up_write(&fs_info
->commit_root_sem
);
185 static inline void extwriter_counter_inc(struct btrfs_transaction
*trans
,
188 if (type
& TRANS_EXTWRITERS
)
189 atomic_inc(&trans
->num_extwriters
);
192 static inline void extwriter_counter_dec(struct btrfs_transaction
*trans
,
195 if (type
& TRANS_EXTWRITERS
)
196 atomic_dec(&trans
->num_extwriters
);
199 static inline void extwriter_counter_init(struct btrfs_transaction
*trans
,
202 atomic_set(&trans
->num_extwriters
, ((type
& TRANS_EXTWRITERS
) ? 1 : 0));
205 static inline int extwriter_counter_read(struct btrfs_transaction
*trans
)
207 return atomic_read(&trans
->num_extwriters
);
211 * To be called after all the new block groups attached to the transaction
212 * handle have been created (btrfs_create_pending_block_groups()).
214 void btrfs_trans_release_chunk_metadata(struct btrfs_trans_handle
*trans
)
216 struct btrfs_fs_info
*fs_info
= trans
->fs_info
;
218 if (!trans
->chunk_bytes_reserved
)
221 WARN_ON_ONCE(!list_empty(&trans
->new_bgs
));
223 btrfs_block_rsv_release(fs_info
, &fs_info
->chunk_block_rsv
,
224 trans
->chunk_bytes_reserved
, NULL
);
225 trans
->chunk_bytes_reserved
= 0;
229 * either allocate a new transaction or hop into the existing one
231 static noinline
int join_transaction(struct btrfs_fs_info
*fs_info
,
234 struct btrfs_transaction
*cur_trans
;
236 spin_lock(&fs_info
->trans_lock
);
238 /* The file system has been taken offline. No new transactions. */
239 if (test_bit(BTRFS_FS_STATE_ERROR
, &fs_info
->fs_state
)) {
240 spin_unlock(&fs_info
->trans_lock
);
244 cur_trans
= fs_info
->running_transaction
;
246 if (TRANS_ABORTED(cur_trans
)) {
247 spin_unlock(&fs_info
->trans_lock
);
248 return cur_trans
->aborted
;
250 if (btrfs_blocked_trans_types
[cur_trans
->state
] & type
) {
251 spin_unlock(&fs_info
->trans_lock
);
254 refcount_inc(&cur_trans
->use_count
);
255 atomic_inc(&cur_trans
->num_writers
);
256 extwriter_counter_inc(cur_trans
, type
);
257 spin_unlock(&fs_info
->trans_lock
);
260 spin_unlock(&fs_info
->trans_lock
);
263 * If we are ATTACH, we just want to catch the current transaction,
264 * and commit it. If there is no transaction, just return ENOENT.
266 if (type
== TRANS_ATTACH
)
270 * JOIN_NOLOCK only happens during the transaction commit, so
271 * it is impossible that ->running_transaction is NULL
273 BUG_ON(type
== TRANS_JOIN_NOLOCK
);
275 cur_trans
= kmalloc(sizeof(*cur_trans
), GFP_NOFS
);
279 spin_lock(&fs_info
->trans_lock
);
280 if (fs_info
->running_transaction
) {
282 * someone started a transaction after we unlocked. Make sure
283 * to redo the checks above
287 } else if (test_bit(BTRFS_FS_STATE_ERROR
, &fs_info
->fs_state
)) {
288 spin_unlock(&fs_info
->trans_lock
);
293 cur_trans
->fs_info
= fs_info
;
294 atomic_set(&cur_trans
->num_writers
, 1);
295 extwriter_counter_init(cur_trans
, type
);
296 init_waitqueue_head(&cur_trans
->writer_wait
);
297 init_waitqueue_head(&cur_trans
->commit_wait
);
298 cur_trans
->state
= TRANS_STATE_RUNNING
;
300 * One for this trans handle, one so it will live on until we
301 * commit the transaction.
303 refcount_set(&cur_trans
->use_count
, 2);
304 cur_trans
->flags
= 0;
305 cur_trans
->start_time
= ktime_get_seconds();
307 memset(&cur_trans
->delayed_refs
, 0, sizeof(cur_trans
->delayed_refs
));
309 cur_trans
->delayed_refs
.href_root
= RB_ROOT_CACHED
;
310 cur_trans
->delayed_refs
.dirty_extent_root
= RB_ROOT
;
311 atomic_set(&cur_trans
->delayed_refs
.num_entries
, 0);
314 * although the tree mod log is per file system and not per transaction,
315 * the log must never go across transaction boundaries.
318 if (!list_empty(&fs_info
->tree_mod_seq_list
))
319 WARN(1, KERN_ERR
"BTRFS: tree_mod_seq_list not empty when creating a fresh transaction\n");
320 if (!RB_EMPTY_ROOT(&fs_info
->tree_mod_log
))
321 WARN(1, KERN_ERR
"BTRFS: tree_mod_log rb tree not empty when creating a fresh transaction\n");
322 atomic64_set(&fs_info
->tree_mod_seq
, 0);
324 spin_lock_init(&cur_trans
->delayed_refs
.lock
);
326 INIT_LIST_HEAD(&cur_trans
->pending_snapshots
);
327 INIT_LIST_HEAD(&cur_trans
->dev_update_list
);
328 INIT_LIST_HEAD(&cur_trans
->switch_commits
);
329 INIT_LIST_HEAD(&cur_trans
->dirty_bgs
);
330 INIT_LIST_HEAD(&cur_trans
->io_bgs
);
331 INIT_LIST_HEAD(&cur_trans
->dropped_roots
);
332 mutex_init(&cur_trans
->cache_write_mutex
);
333 spin_lock_init(&cur_trans
->dirty_bgs_lock
);
334 INIT_LIST_HEAD(&cur_trans
->deleted_bgs
);
335 spin_lock_init(&cur_trans
->dropped_roots_lock
);
336 list_add_tail(&cur_trans
->list
, &fs_info
->trans_list
);
337 extent_io_tree_init(fs_info
, &cur_trans
->dirty_pages
,
338 IO_TREE_TRANS_DIRTY_PAGES
, fs_info
->btree_inode
);
339 extent_io_tree_init(fs_info
, &cur_trans
->pinned_extents
,
340 IO_TREE_FS_PINNED_EXTENTS
, NULL
);
341 fs_info
->generation
++;
342 cur_trans
->transid
= fs_info
->generation
;
343 fs_info
->running_transaction
= cur_trans
;
344 cur_trans
->aborted
= 0;
345 spin_unlock(&fs_info
->trans_lock
);
351 * this does all the record keeping required to make sure that a reference
352 * counted root is properly recorded in a given transaction. This is required
353 * to make sure the old root from before we joined the transaction is deleted
354 * when the transaction commits
356 static int record_root_in_trans(struct btrfs_trans_handle
*trans
,
357 struct btrfs_root
*root
,
360 struct btrfs_fs_info
*fs_info
= root
->fs_info
;
362 if ((test_bit(BTRFS_ROOT_REF_COWS
, &root
->state
) &&
363 root
->last_trans
< trans
->transid
) || force
) {
364 WARN_ON(root
== fs_info
->extent_root
);
365 WARN_ON(!force
&& root
->commit_root
!= root
->node
);
368 * see below for IN_TRANS_SETUP usage rules
369 * we have the reloc mutex held now, so there
370 * is only one writer in this function
372 set_bit(BTRFS_ROOT_IN_TRANS_SETUP
, &root
->state
);
374 /* make sure readers find IN_TRANS_SETUP before
375 * they find our root->last_trans update
379 spin_lock(&fs_info
->fs_roots_radix_lock
);
380 if (root
->last_trans
== trans
->transid
&& !force
) {
381 spin_unlock(&fs_info
->fs_roots_radix_lock
);
384 radix_tree_tag_set(&fs_info
->fs_roots_radix
,
385 (unsigned long)root
->root_key
.objectid
,
386 BTRFS_ROOT_TRANS_TAG
);
387 spin_unlock(&fs_info
->fs_roots_radix_lock
);
388 root
->last_trans
= trans
->transid
;
390 /* this is pretty tricky. We don't want to
391 * take the relocation lock in btrfs_record_root_in_trans
392 * unless we're really doing the first setup for this root in
395 * Normally we'd use root->last_trans as a flag to decide
396 * if we want to take the expensive mutex.
398 * But, we have to set root->last_trans before we
399 * init the relocation root, otherwise, we trip over warnings
400 * in ctree.c. The solution used here is to flag ourselves
401 * with root IN_TRANS_SETUP. When this is 1, we're still
402 * fixing up the reloc trees and everyone must wait.
404 * When this is zero, they can trust root->last_trans and fly
405 * through btrfs_record_root_in_trans without having to take the
406 * lock. smp_wmb() makes sure that all the writes above are
407 * done before we pop in the zero below
409 btrfs_init_reloc_root(trans
, root
);
410 smp_mb__before_atomic();
411 clear_bit(BTRFS_ROOT_IN_TRANS_SETUP
, &root
->state
);
417 void btrfs_add_dropped_root(struct btrfs_trans_handle
*trans
,
418 struct btrfs_root
*root
)
420 struct btrfs_fs_info
*fs_info
= root
->fs_info
;
421 struct btrfs_transaction
*cur_trans
= trans
->transaction
;
423 /* Add ourselves to the transaction dropped list */
424 spin_lock(&cur_trans
->dropped_roots_lock
);
425 list_add_tail(&root
->root_list
, &cur_trans
->dropped_roots
);
426 spin_unlock(&cur_trans
->dropped_roots_lock
);
428 /* Make sure we don't try to update the root at commit time */
429 spin_lock(&fs_info
->fs_roots_radix_lock
);
430 radix_tree_tag_clear(&fs_info
->fs_roots_radix
,
431 (unsigned long)root
->root_key
.objectid
,
432 BTRFS_ROOT_TRANS_TAG
);
433 spin_unlock(&fs_info
->fs_roots_radix_lock
);
436 int btrfs_record_root_in_trans(struct btrfs_trans_handle
*trans
,
437 struct btrfs_root
*root
)
439 struct btrfs_fs_info
*fs_info
= root
->fs_info
;
441 if (!test_bit(BTRFS_ROOT_REF_COWS
, &root
->state
))
445 * see record_root_in_trans for comments about IN_TRANS_SETUP usage
449 if (root
->last_trans
== trans
->transid
&&
450 !test_bit(BTRFS_ROOT_IN_TRANS_SETUP
, &root
->state
))
453 mutex_lock(&fs_info
->reloc_mutex
);
454 record_root_in_trans(trans
, root
, 0);
455 mutex_unlock(&fs_info
->reloc_mutex
);
460 static inline int is_transaction_blocked(struct btrfs_transaction
*trans
)
462 return (trans
->state
>= TRANS_STATE_COMMIT_START
&&
463 trans
->state
< TRANS_STATE_UNBLOCKED
&&
464 !TRANS_ABORTED(trans
));
467 /* wait for commit against the current transaction to become unblocked
468 * when this is done, it is safe to start a new transaction, but the current
469 * transaction might not be fully on disk.
471 static void wait_current_trans(struct btrfs_fs_info
*fs_info
)
473 struct btrfs_transaction
*cur_trans
;
475 spin_lock(&fs_info
->trans_lock
);
476 cur_trans
= fs_info
->running_transaction
;
477 if (cur_trans
&& is_transaction_blocked(cur_trans
)) {
478 refcount_inc(&cur_trans
->use_count
);
479 spin_unlock(&fs_info
->trans_lock
);
481 wait_event(fs_info
->transaction_wait
,
482 cur_trans
->state
>= TRANS_STATE_UNBLOCKED
||
483 TRANS_ABORTED(cur_trans
));
484 btrfs_put_transaction(cur_trans
);
486 spin_unlock(&fs_info
->trans_lock
);
490 static int may_wait_transaction(struct btrfs_fs_info
*fs_info
, int type
)
492 if (test_bit(BTRFS_FS_LOG_RECOVERING
, &fs_info
->flags
))
495 if (type
== TRANS_START
)
501 static inline bool need_reserve_reloc_root(struct btrfs_root
*root
)
503 struct btrfs_fs_info
*fs_info
= root
->fs_info
;
505 if (!fs_info
->reloc_ctl
||
506 !test_bit(BTRFS_ROOT_REF_COWS
, &root
->state
) ||
507 root
->root_key
.objectid
== BTRFS_TREE_RELOC_OBJECTID
||
514 static struct btrfs_trans_handle
*
515 start_transaction(struct btrfs_root
*root
, unsigned int num_items
,
516 unsigned int type
, enum btrfs_reserve_flush_enum flush
,
517 bool enforce_qgroups
)
519 struct btrfs_fs_info
*fs_info
= root
->fs_info
;
520 struct btrfs_block_rsv
*delayed_refs_rsv
= &fs_info
->delayed_refs_rsv
;
521 struct btrfs_trans_handle
*h
;
522 struct btrfs_transaction
*cur_trans
;
524 u64 qgroup_reserved
= 0;
525 bool reloc_reserved
= false;
528 /* Send isn't supposed to start transactions. */
529 ASSERT(current
->journal_info
!= BTRFS_SEND_TRANS_STUB
);
531 if (test_bit(BTRFS_FS_STATE_ERROR
, &fs_info
->fs_state
))
532 return ERR_PTR(-EROFS
);
534 if (current
->journal_info
) {
535 WARN_ON(type
& TRANS_EXTWRITERS
);
536 h
= current
->journal_info
;
537 refcount_inc(&h
->use_count
);
538 WARN_ON(refcount_read(&h
->use_count
) > 2);
539 h
->orig_rsv
= h
->block_rsv
;
545 * Do the reservation before we join the transaction so we can do all
546 * the appropriate flushing if need be.
548 if (num_items
&& root
!= fs_info
->chunk_root
) {
549 struct btrfs_block_rsv
*rsv
= &fs_info
->trans_block_rsv
;
550 u64 delayed_refs_bytes
= 0;
552 qgroup_reserved
= num_items
* fs_info
->nodesize
;
553 ret
= btrfs_qgroup_reserve_meta_pertrans(root
, qgroup_reserved
,
559 * We want to reserve all the bytes we may need all at once, so
560 * we only do 1 enospc flushing cycle per transaction start. We
561 * accomplish this by simply assuming we'll do 2 x num_items
562 * worth of delayed refs updates in this trans handle, and
563 * refill that amount for whatever is missing in the reserve.
565 num_bytes
= btrfs_calc_insert_metadata_size(fs_info
, num_items
);
566 if (delayed_refs_rsv
->full
== 0) {
567 delayed_refs_bytes
= num_bytes
;
572 * Do the reservation for the relocation root creation
574 if (need_reserve_reloc_root(root
)) {
575 num_bytes
+= fs_info
->nodesize
;
576 reloc_reserved
= true;
579 ret
= btrfs_block_rsv_add(root
, rsv
, num_bytes
, flush
);
582 if (delayed_refs_bytes
) {
583 btrfs_migrate_to_delayed_refs_rsv(fs_info
, rsv
,
585 num_bytes
-= delayed_refs_bytes
;
587 } else if (num_items
== 0 && flush
== BTRFS_RESERVE_FLUSH_ALL
&&
588 !delayed_refs_rsv
->full
) {
590 * Some people call with btrfs_start_transaction(root, 0)
591 * because they can be throttled, but have some other mechanism
592 * for reserving space. We still want these guys to refill the
593 * delayed block_rsv so just add 1 items worth of reservation
596 ret
= btrfs_delayed_refs_rsv_refill(fs_info
, flush
);
601 h
= kmem_cache_zalloc(btrfs_trans_handle_cachep
, GFP_NOFS
);
608 * If we are JOIN_NOLOCK we're already committing a transaction and
609 * waiting on this guy, so we don't need to do the sb_start_intwrite
610 * because we're already holding a ref. We need this because we could
611 * have raced in and did an fsync() on a file which can kick a commit
612 * and then we deadlock with somebody doing a freeze.
614 * If we are ATTACH, it means we just want to catch the current
615 * transaction and commit it, so we needn't do sb_start_intwrite().
617 if (type
& __TRANS_FREEZABLE
)
618 sb_start_intwrite(fs_info
->sb
);
620 if (may_wait_transaction(fs_info
, type
))
621 wait_current_trans(fs_info
);
624 ret
= join_transaction(fs_info
, type
);
626 wait_current_trans(fs_info
);
627 if (unlikely(type
== TRANS_ATTACH
||
628 type
== TRANS_JOIN_NOSTART
))
631 } while (ret
== -EBUSY
);
636 cur_trans
= fs_info
->running_transaction
;
638 h
->transid
= cur_trans
->transid
;
639 h
->transaction
= cur_trans
;
641 refcount_set(&h
->use_count
, 1);
642 h
->fs_info
= root
->fs_info
;
645 h
->can_flush_pending_bgs
= true;
646 INIT_LIST_HEAD(&h
->new_bgs
);
649 if (cur_trans
->state
>= TRANS_STATE_COMMIT_START
&&
650 may_wait_transaction(fs_info
, type
)) {
651 current
->journal_info
= h
;
652 btrfs_commit_transaction(h
);
657 trace_btrfs_space_reservation(fs_info
, "transaction",
658 h
->transid
, num_bytes
, 1);
659 h
->block_rsv
= &fs_info
->trans_block_rsv
;
660 h
->bytes_reserved
= num_bytes
;
661 h
->reloc_reserved
= reloc_reserved
;
665 if (!current
->journal_info
)
666 current
->journal_info
= h
;
669 * btrfs_record_root_in_trans() needs to alloc new extents, and may
670 * call btrfs_join_transaction() while we're also starting a
673 * Thus it need to be called after current->journal_info initialized,
674 * or we can deadlock.
676 btrfs_record_root_in_trans(h
, root
);
681 if (type
& __TRANS_FREEZABLE
)
682 sb_end_intwrite(fs_info
->sb
);
683 kmem_cache_free(btrfs_trans_handle_cachep
, h
);
686 btrfs_block_rsv_release(fs_info
, &fs_info
->trans_block_rsv
,
689 btrfs_qgroup_free_meta_pertrans(root
, qgroup_reserved
);
693 struct btrfs_trans_handle
*btrfs_start_transaction(struct btrfs_root
*root
,
694 unsigned int num_items
)
696 return start_transaction(root
, num_items
, TRANS_START
,
697 BTRFS_RESERVE_FLUSH_ALL
, true);
700 struct btrfs_trans_handle
*btrfs_start_transaction_fallback_global_rsv(
701 struct btrfs_root
*root
,
702 unsigned int num_items
,
705 struct btrfs_fs_info
*fs_info
= root
->fs_info
;
706 struct btrfs_trans_handle
*trans
;
711 * We have two callers: unlink and block group removal. The
712 * former should succeed even if we will temporarily exceed
713 * quota and the latter operates on the extent root so
714 * qgroup enforcement is ignored anyway.
716 trans
= start_transaction(root
, num_items
, TRANS_START
,
717 BTRFS_RESERVE_FLUSH_ALL
, false);
718 if (!IS_ERR(trans
) || PTR_ERR(trans
) != -ENOSPC
)
721 trans
= btrfs_start_transaction(root
, 0);
725 num_bytes
= btrfs_calc_insert_metadata_size(fs_info
, num_items
);
726 ret
= btrfs_cond_migrate_bytes(fs_info
, &fs_info
->trans_block_rsv
,
727 num_bytes
, min_factor
);
729 btrfs_end_transaction(trans
);
733 trans
->block_rsv
= &fs_info
->trans_block_rsv
;
734 trans
->bytes_reserved
= num_bytes
;
735 trace_btrfs_space_reservation(fs_info
, "transaction",
736 trans
->transid
, num_bytes
, 1);
741 struct btrfs_trans_handle
*btrfs_join_transaction(struct btrfs_root
*root
)
743 return start_transaction(root
, 0, TRANS_JOIN
, BTRFS_RESERVE_NO_FLUSH
,
747 struct btrfs_trans_handle
*btrfs_join_transaction_spacecache(struct btrfs_root
*root
)
749 return start_transaction(root
, 0, TRANS_JOIN_NOLOCK
,
750 BTRFS_RESERVE_NO_FLUSH
, true);
754 * Similar to regular join but it never starts a transaction when none is
755 * running or after waiting for the current one to finish.
757 struct btrfs_trans_handle
*btrfs_join_transaction_nostart(struct btrfs_root
*root
)
759 return start_transaction(root
, 0, TRANS_JOIN_NOSTART
,
760 BTRFS_RESERVE_NO_FLUSH
, true);
764 * btrfs_attach_transaction() - catch the running transaction
766 * It is used when we want to commit the current the transaction, but
767 * don't want to start a new one.
769 * Note: If this function return -ENOENT, it just means there is no
770 * running transaction. But it is possible that the inactive transaction
771 * is still in the memory, not fully on disk. If you hope there is no
772 * inactive transaction in the fs when -ENOENT is returned, you should
774 * btrfs_attach_transaction_barrier()
776 struct btrfs_trans_handle
*btrfs_attach_transaction(struct btrfs_root
*root
)
778 return start_transaction(root
, 0, TRANS_ATTACH
,
779 BTRFS_RESERVE_NO_FLUSH
, true);
783 * btrfs_attach_transaction_barrier() - catch the running transaction
785 * It is similar to the above function, the difference is this one
786 * will wait for all the inactive transactions until they fully
789 struct btrfs_trans_handle
*
790 btrfs_attach_transaction_barrier(struct btrfs_root
*root
)
792 struct btrfs_trans_handle
*trans
;
794 trans
= start_transaction(root
, 0, TRANS_ATTACH
,
795 BTRFS_RESERVE_NO_FLUSH
, true);
796 if (trans
== ERR_PTR(-ENOENT
))
797 btrfs_wait_for_commit(root
->fs_info
, 0);
802 /* wait for a transaction commit to be fully complete */
803 static noinline
void wait_for_commit(struct btrfs_transaction
*commit
)
805 wait_event(commit
->commit_wait
, commit
->state
== TRANS_STATE_COMPLETED
);
808 int btrfs_wait_for_commit(struct btrfs_fs_info
*fs_info
, u64 transid
)
810 struct btrfs_transaction
*cur_trans
= NULL
, *t
;
814 if (transid
<= fs_info
->last_trans_committed
)
817 /* find specified transaction */
818 spin_lock(&fs_info
->trans_lock
);
819 list_for_each_entry(t
, &fs_info
->trans_list
, list
) {
820 if (t
->transid
== transid
) {
822 refcount_inc(&cur_trans
->use_count
);
826 if (t
->transid
> transid
) {
831 spin_unlock(&fs_info
->trans_lock
);
834 * The specified transaction doesn't exist, or we
835 * raced with btrfs_commit_transaction
838 if (transid
> fs_info
->last_trans_committed
)
843 /* find newest transaction that is committing | committed */
844 spin_lock(&fs_info
->trans_lock
);
845 list_for_each_entry_reverse(t
, &fs_info
->trans_list
,
847 if (t
->state
>= TRANS_STATE_COMMIT_START
) {
848 if (t
->state
== TRANS_STATE_COMPLETED
)
851 refcount_inc(&cur_trans
->use_count
);
855 spin_unlock(&fs_info
->trans_lock
);
857 goto out
; /* nothing committing|committed */
860 wait_for_commit(cur_trans
);
861 btrfs_put_transaction(cur_trans
);
866 void btrfs_throttle(struct btrfs_fs_info
*fs_info
)
868 wait_current_trans(fs_info
);
871 static int should_end_transaction(struct btrfs_trans_handle
*trans
)
873 struct btrfs_fs_info
*fs_info
= trans
->fs_info
;
875 if (btrfs_check_space_for_delayed_refs(fs_info
))
878 return !!btrfs_block_rsv_check(&fs_info
->global_block_rsv
, 5);
881 int btrfs_should_end_transaction(struct btrfs_trans_handle
*trans
)
883 struct btrfs_transaction
*cur_trans
= trans
->transaction
;
886 if (cur_trans
->state
>= TRANS_STATE_COMMIT_START
||
887 cur_trans
->delayed_refs
.flushing
)
890 return should_end_transaction(trans
);
893 static void btrfs_trans_release_metadata(struct btrfs_trans_handle
*trans
)
896 struct btrfs_fs_info
*fs_info
= trans
->fs_info
;
898 if (!trans
->block_rsv
) {
899 ASSERT(!trans
->bytes_reserved
);
903 if (!trans
->bytes_reserved
)
906 ASSERT(trans
->block_rsv
== &fs_info
->trans_block_rsv
);
907 trace_btrfs_space_reservation(fs_info
, "transaction",
908 trans
->transid
, trans
->bytes_reserved
, 0);
909 btrfs_block_rsv_release(fs_info
, trans
->block_rsv
,
910 trans
->bytes_reserved
, NULL
);
911 trans
->bytes_reserved
= 0;
914 static int __btrfs_end_transaction(struct btrfs_trans_handle
*trans
,
917 struct btrfs_fs_info
*info
= trans
->fs_info
;
918 struct btrfs_transaction
*cur_trans
= trans
->transaction
;
921 if (refcount_read(&trans
->use_count
) > 1) {
922 refcount_dec(&trans
->use_count
);
923 trans
->block_rsv
= trans
->orig_rsv
;
927 btrfs_trans_release_metadata(trans
);
928 trans
->block_rsv
= NULL
;
930 btrfs_create_pending_block_groups(trans
);
932 btrfs_trans_release_chunk_metadata(trans
);
934 if (trans
->type
& __TRANS_FREEZABLE
)
935 sb_end_intwrite(info
->sb
);
937 WARN_ON(cur_trans
!= info
->running_transaction
);
938 WARN_ON(atomic_read(&cur_trans
->num_writers
) < 1);
939 atomic_dec(&cur_trans
->num_writers
);
940 extwriter_counter_dec(cur_trans
, trans
->type
);
942 cond_wake_up(&cur_trans
->writer_wait
);
943 btrfs_put_transaction(cur_trans
);
945 if (current
->journal_info
== trans
)
946 current
->journal_info
= NULL
;
949 btrfs_run_delayed_iputs(info
);
951 if (TRANS_ABORTED(trans
) ||
952 test_bit(BTRFS_FS_STATE_ERROR
, &info
->fs_state
)) {
953 wake_up_process(info
->transaction_kthread
);
957 kmem_cache_free(btrfs_trans_handle_cachep
, trans
);
961 int btrfs_end_transaction(struct btrfs_trans_handle
*trans
)
963 return __btrfs_end_transaction(trans
, 0);
966 int btrfs_end_transaction_throttle(struct btrfs_trans_handle
*trans
)
968 return __btrfs_end_transaction(trans
, 1);
972 * when btree blocks are allocated, they have some corresponding bits set for
973 * them in one of two extent_io trees. This is used to make sure all of
974 * those extents are sent to disk but does not wait on them
976 int btrfs_write_marked_extents(struct btrfs_fs_info
*fs_info
,
977 struct extent_io_tree
*dirty_pages
, int mark
)
981 struct address_space
*mapping
= fs_info
->btree_inode
->i_mapping
;
982 struct extent_state
*cached_state
= NULL
;
986 atomic_inc(&BTRFS_I(fs_info
->btree_inode
)->sync_writers
);
987 while (!find_first_extent_bit(dirty_pages
, start
, &start
, &end
,
988 mark
, &cached_state
)) {
989 bool wait_writeback
= false;
991 err
= convert_extent_bit(dirty_pages
, start
, end
,
993 mark
, &cached_state
);
995 * convert_extent_bit can return -ENOMEM, which is most of the
996 * time a temporary error. So when it happens, ignore the error
997 * and wait for writeback of this range to finish - because we
998 * failed to set the bit EXTENT_NEED_WAIT for the range, a call
999 * to __btrfs_wait_marked_extents() would not know that
1000 * writeback for this range started and therefore wouldn't
1001 * wait for it to finish - we don't want to commit a
1002 * superblock that points to btree nodes/leafs for which
1003 * writeback hasn't finished yet (and without errors).
1004 * We cleanup any entries left in the io tree when committing
1005 * the transaction (through extent_io_tree_release()).
1007 if (err
== -ENOMEM
) {
1009 wait_writeback
= true;
1012 err
= filemap_fdatawrite_range(mapping
, start
, end
);
1015 else if (wait_writeback
)
1016 werr
= filemap_fdatawait_range(mapping
, start
, end
);
1017 free_extent_state(cached_state
);
1018 cached_state
= NULL
;
1022 atomic_dec(&BTRFS_I(fs_info
->btree_inode
)->sync_writers
);
1027 * when btree blocks are allocated, they have some corresponding bits set for
1028 * them in one of two extent_io trees. This is used to make sure all of
1029 * those extents are on disk for transaction or log commit. We wait
1030 * on all the pages and clear them from the dirty pages state tree
1032 static int __btrfs_wait_marked_extents(struct btrfs_fs_info
*fs_info
,
1033 struct extent_io_tree
*dirty_pages
)
1037 struct address_space
*mapping
= fs_info
->btree_inode
->i_mapping
;
1038 struct extent_state
*cached_state
= NULL
;
1042 while (!find_first_extent_bit(dirty_pages
, start
, &start
, &end
,
1043 EXTENT_NEED_WAIT
, &cached_state
)) {
1045 * Ignore -ENOMEM errors returned by clear_extent_bit().
1046 * When committing the transaction, we'll remove any entries
1047 * left in the io tree. For a log commit, we don't remove them
1048 * after committing the log because the tree can be accessed
1049 * concurrently - we do it only at transaction commit time when
1050 * it's safe to do it (through extent_io_tree_release()).
1052 err
= clear_extent_bit(dirty_pages
, start
, end
,
1053 EXTENT_NEED_WAIT
, 0, 0, &cached_state
);
1057 err
= filemap_fdatawait_range(mapping
, start
, end
);
1060 free_extent_state(cached_state
);
1061 cached_state
= NULL
;
1070 static int btrfs_wait_extents(struct btrfs_fs_info
*fs_info
,
1071 struct extent_io_tree
*dirty_pages
)
1073 bool errors
= false;
1076 err
= __btrfs_wait_marked_extents(fs_info
, dirty_pages
);
1077 if (test_and_clear_bit(BTRFS_FS_BTREE_ERR
, &fs_info
->flags
))
1085 int btrfs_wait_tree_log_extents(struct btrfs_root
*log_root
, int mark
)
1087 struct btrfs_fs_info
*fs_info
= log_root
->fs_info
;
1088 struct extent_io_tree
*dirty_pages
= &log_root
->dirty_log_pages
;
1089 bool errors
= false;
1092 ASSERT(log_root
->root_key
.objectid
== BTRFS_TREE_LOG_OBJECTID
);
1094 err
= __btrfs_wait_marked_extents(fs_info
, dirty_pages
);
1095 if ((mark
& EXTENT_DIRTY
) &&
1096 test_and_clear_bit(BTRFS_FS_LOG1_ERR
, &fs_info
->flags
))
1099 if ((mark
& EXTENT_NEW
) &&
1100 test_and_clear_bit(BTRFS_FS_LOG2_ERR
, &fs_info
->flags
))
1109 * When btree blocks are allocated the corresponding extents are marked dirty.
1110 * This function ensures such extents are persisted on disk for transaction or
1113 * @trans: transaction whose dirty pages we'd like to write
1115 static int btrfs_write_and_wait_transaction(struct btrfs_trans_handle
*trans
)
1119 struct extent_io_tree
*dirty_pages
= &trans
->transaction
->dirty_pages
;
1120 struct btrfs_fs_info
*fs_info
= trans
->fs_info
;
1121 struct blk_plug plug
;
1123 blk_start_plug(&plug
);
1124 ret
= btrfs_write_marked_extents(fs_info
, dirty_pages
, EXTENT_DIRTY
);
1125 blk_finish_plug(&plug
);
1126 ret2
= btrfs_wait_extents(fs_info
, dirty_pages
);
1128 extent_io_tree_release(&trans
->transaction
->dirty_pages
);
1139 * this is used to update the root pointer in the tree of tree roots.
1141 * But, in the case of the extent allocation tree, updating the root
1142 * pointer may allocate blocks which may change the root of the extent
1145 * So, this loops and repeats and makes sure the cowonly root didn't
1146 * change while the root pointer was being updated in the metadata.
1148 static int update_cowonly_root(struct btrfs_trans_handle
*trans
,
1149 struct btrfs_root
*root
)
1152 u64 old_root_bytenr
;
1154 struct btrfs_fs_info
*fs_info
= root
->fs_info
;
1155 struct btrfs_root
*tree_root
= fs_info
->tree_root
;
1157 old_root_used
= btrfs_root_used(&root
->root_item
);
1160 old_root_bytenr
= btrfs_root_bytenr(&root
->root_item
);
1161 if (old_root_bytenr
== root
->node
->start
&&
1162 old_root_used
== btrfs_root_used(&root
->root_item
))
1165 btrfs_set_root_node(&root
->root_item
, root
->node
);
1166 ret
= btrfs_update_root(trans
, tree_root
,
1172 old_root_used
= btrfs_root_used(&root
->root_item
);
1179 * update all the cowonly tree roots on disk
1181 * The error handling in this function may not be obvious. Any of the
1182 * failures will cause the file system to go offline. We still need
1183 * to clean up the delayed refs.
1185 static noinline
int commit_cowonly_roots(struct btrfs_trans_handle
*trans
)
1187 struct btrfs_fs_info
*fs_info
= trans
->fs_info
;
1188 struct list_head
*dirty_bgs
= &trans
->transaction
->dirty_bgs
;
1189 struct list_head
*io_bgs
= &trans
->transaction
->io_bgs
;
1190 struct list_head
*next
;
1191 struct extent_buffer
*eb
;
1194 eb
= btrfs_lock_root_node(fs_info
->tree_root
);
1195 ret
= btrfs_cow_block(trans
, fs_info
->tree_root
, eb
, NULL
,
1197 btrfs_tree_unlock(eb
);
1198 free_extent_buffer(eb
);
1203 ret
= btrfs_run_delayed_refs(trans
, (unsigned long)-1);
1207 ret
= btrfs_run_dev_stats(trans
);
1210 ret
= btrfs_run_dev_replace(trans
);
1213 ret
= btrfs_run_qgroups(trans
);
1217 ret
= btrfs_setup_space_cache(trans
);
1221 /* run_qgroups might have added some more refs */
1222 ret
= btrfs_run_delayed_refs(trans
, (unsigned long)-1);
1226 while (!list_empty(&fs_info
->dirty_cowonly_roots
)) {
1227 struct btrfs_root
*root
;
1228 next
= fs_info
->dirty_cowonly_roots
.next
;
1229 list_del_init(next
);
1230 root
= list_entry(next
, struct btrfs_root
, dirty_list
);
1231 clear_bit(BTRFS_ROOT_DIRTY
, &root
->state
);
1233 if (root
!= fs_info
->extent_root
)
1234 list_add_tail(&root
->dirty_list
,
1235 &trans
->transaction
->switch_commits
);
1236 ret
= update_cowonly_root(trans
, root
);
1239 ret
= btrfs_run_delayed_refs(trans
, (unsigned long)-1);
1244 while (!list_empty(dirty_bgs
) || !list_empty(io_bgs
)) {
1245 ret
= btrfs_write_dirty_block_groups(trans
);
1248 ret
= btrfs_run_delayed_refs(trans
, (unsigned long)-1);
1253 if (!list_empty(&fs_info
->dirty_cowonly_roots
))
1256 list_add_tail(&fs_info
->extent_root
->dirty_list
,
1257 &trans
->transaction
->switch_commits
);
1259 /* Update dev-replace pointer once everything is committed */
1260 fs_info
->dev_replace
.committed_cursor_left
=
1261 fs_info
->dev_replace
.cursor_left_last_write_of_item
;
1267 * dead roots are old snapshots that need to be deleted. This allocates
1268 * a dirty root struct and adds it into the list of dead roots that need to
1271 void btrfs_add_dead_root(struct btrfs_root
*root
)
1273 struct btrfs_fs_info
*fs_info
= root
->fs_info
;
1275 spin_lock(&fs_info
->trans_lock
);
1276 if (list_empty(&root
->root_list
)) {
1277 btrfs_grab_root(root
);
1278 list_add_tail(&root
->root_list
, &fs_info
->dead_roots
);
1280 spin_unlock(&fs_info
->trans_lock
);
1284 * update all the cowonly tree roots on disk
1286 static noinline
int commit_fs_roots(struct btrfs_trans_handle
*trans
)
1288 struct btrfs_fs_info
*fs_info
= trans
->fs_info
;
1289 struct btrfs_root
*gang
[8];
1294 spin_lock(&fs_info
->fs_roots_radix_lock
);
1296 ret
= radix_tree_gang_lookup_tag(&fs_info
->fs_roots_radix
,
1299 BTRFS_ROOT_TRANS_TAG
);
1302 for (i
= 0; i
< ret
; i
++) {
1303 struct btrfs_root
*root
= gang
[i
];
1304 radix_tree_tag_clear(&fs_info
->fs_roots_radix
,
1305 (unsigned long)root
->root_key
.objectid
,
1306 BTRFS_ROOT_TRANS_TAG
);
1307 spin_unlock(&fs_info
->fs_roots_radix_lock
);
1309 btrfs_free_log(trans
, root
);
1310 btrfs_update_reloc_root(trans
, root
);
1312 btrfs_save_ino_cache(root
, trans
);
1314 /* see comments in should_cow_block() */
1315 clear_bit(BTRFS_ROOT_FORCE_COW
, &root
->state
);
1316 smp_mb__after_atomic();
1318 if (root
->commit_root
!= root
->node
) {
1319 list_add_tail(&root
->dirty_list
,
1320 &trans
->transaction
->switch_commits
);
1321 btrfs_set_root_node(&root
->root_item
,
1325 err
= btrfs_update_root(trans
, fs_info
->tree_root
,
1328 spin_lock(&fs_info
->fs_roots_radix_lock
);
1331 btrfs_qgroup_free_meta_all_pertrans(root
);
1334 spin_unlock(&fs_info
->fs_roots_radix_lock
);
1339 * defrag a given btree.
1340 * Every leaf in the btree is read and defragged.
1342 int btrfs_defrag_root(struct btrfs_root
*root
)
1344 struct btrfs_fs_info
*info
= root
->fs_info
;
1345 struct btrfs_trans_handle
*trans
;
1348 if (test_and_set_bit(BTRFS_ROOT_DEFRAG_RUNNING
, &root
->state
))
1352 trans
= btrfs_start_transaction(root
, 0);
1354 return PTR_ERR(trans
);
1356 ret
= btrfs_defrag_leaves(trans
, root
);
1358 btrfs_end_transaction(trans
);
1359 btrfs_btree_balance_dirty(info
);
1362 if (btrfs_fs_closing(info
) || ret
!= -EAGAIN
)
1365 if (btrfs_defrag_cancelled(info
)) {
1366 btrfs_debug(info
, "defrag_root cancelled");
1371 clear_bit(BTRFS_ROOT_DEFRAG_RUNNING
, &root
->state
);
1376 * Do all special snapshot related qgroup dirty hack.
1378 * Will do all needed qgroup inherit and dirty hack like switch commit
1379 * roots inside one transaction and write all btree into disk, to make
1382 static int qgroup_account_snapshot(struct btrfs_trans_handle
*trans
,
1383 struct btrfs_root
*src
,
1384 struct btrfs_root
*parent
,
1385 struct btrfs_qgroup_inherit
*inherit
,
1388 struct btrfs_fs_info
*fs_info
= src
->fs_info
;
1392 * Save some performance in the case that qgroups are not
1393 * enabled. If this check races with the ioctl, rescan will
1396 if (!test_bit(BTRFS_FS_QUOTA_ENABLED
, &fs_info
->flags
))
1400 * Ensure dirty @src will be committed. Or, after coming
1401 * commit_fs_roots() and switch_commit_roots(), any dirty but not
1402 * recorded root will never be updated again, causing an outdated root
1405 record_root_in_trans(trans
, src
, 1);
1408 * We are going to commit transaction, see btrfs_commit_transaction()
1409 * comment for reason locking tree_log_mutex
1411 mutex_lock(&fs_info
->tree_log_mutex
);
1413 ret
= commit_fs_roots(trans
);
1416 ret
= btrfs_qgroup_account_extents(trans
);
1420 /* Now qgroup are all updated, we can inherit it to new qgroups */
1421 ret
= btrfs_qgroup_inherit(trans
, src
->root_key
.objectid
, dst_objectid
,
1427 * Now we do a simplified commit transaction, which will:
1428 * 1) commit all subvolume and extent tree
1429 * To ensure all subvolume and extent tree have a valid
1430 * commit_root to accounting later insert_dir_item()
1431 * 2) write all btree blocks onto disk
1432 * This is to make sure later btree modification will be cowed
1433 * Or commit_root can be populated and cause wrong qgroup numbers
1434 * In this simplified commit, we don't really care about other trees
1435 * like chunk and root tree, as they won't affect qgroup.
1436 * And we don't write super to avoid half committed status.
1438 ret
= commit_cowonly_roots(trans
);
1441 switch_commit_roots(trans
);
1442 ret
= btrfs_write_and_wait_transaction(trans
);
1444 btrfs_handle_fs_error(fs_info
, ret
,
1445 "Error while writing out transaction for qgroup");
1448 mutex_unlock(&fs_info
->tree_log_mutex
);
1451 * Force parent root to be updated, as we recorded it before so its
1452 * last_trans == cur_transid.
1453 * Or it won't be committed again onto disk after later
1457 record_root_in_trans(trans
, parent
, 1);
1462 * new snapshots need to be created at a very specific time in the
1463 * transaction commit. This does the actual creation.
1466 * If the error which may affect the commitment of the current transaction
1467 * happens, we should return the error number. If the error which just affect
1468 * the creation of the pending snapshots, just return 0.
1470 static noinline
int create_pending_snapshot(struct btrfs_trans_handle
*trans
,
1471 struct btrfs_pending_snapshot
*pending
)
1474 struct btrfs_fs_info
*fs_info
= trans
->fs_info
;
1475 struct btrfs_key key
;
1476 struct btrfs_root_item
*new_root_item
;
1477 struct btrfs_root
*tree_root
= fs_info
->tree_root
;
1478 struct btrfs_root
*root
= pending
->root
;
1479 struct btrfs_root
*parent_root
;
1480 struct btrfs_block_rsv
*rsv
;
1481 struct inode
*parent_inode
;
1482 struct btrfs_path
*path
;
1483 struct btrfs_dir_item
*dir_item
;
1484 struct dentry
*dentry
;
1485 struct extent_buffer
*tmp
;
1486 struct extent_buffer
*old
;
1487 struct timespec64 cur_time
;
1494 ASSERT(pending
->path
);
1495 path
= pending
->path
;
1497 ASSERT(pending
->root_item
);
1498 new_root_item
= pending
->root_item
;
1500 pending
->error
= btrfs_find_free_objectid(tree_root
, &objectid
);
1502 goto no_free_objectid
;
1505 * Make qgroup to skip current new snapshot's qgroupid, as it is
1506 * accounted by later btrfs_qgroup_inherit().
1508 btrfs_set_skip_qgroup(trans
, objectid
);
1510 btrfs_reloc_pre_snapshot(pending
, &to_reserve
);
1512 if (to_reserve
> 0) {
1513 pending
->error
= btrfs_block_rsv_add(root
,
1514 &pending
->block_rsv
,
1516 BTRFS_RESERVE_NO_FLUSH
);
1518 goto clear_skip_qgroup
;
1521 key
.objectid
= objectid
;
1522 key
.offset
= (u64
)-1;
1523 key
.type
= BTRFS_ROOT_ITEM_KEY
;
1525 rsv
= trans
->block_rsv
;
1526 trans
->block_rsv
= &pending
->block_rsv
;
1527 trans
->bytes_reserved
= trans
->block_rsv
->reserved
;
1528 trace_btrfs_space_reservation(fs_info
, "transaction",
1530 trans
->bytes_reserved
, 1);
1531 dentry
= pending
->dentry
;
1532 parent_inode
= pending
->dir
;
1533 parent_root
= BTRFS_I(parent_inode
)->root
;
1534 record_root_in_trans(trans
, parent_root
, 0);
1536 cur_time
= current_time(parent_inode
);
1539 * insert the directory item
1541 ret
= btrfs_set_inode_index(BTRFS_I(parent_inode
), &index
);
1542 BUG_ON(ret
); /* -ENOMEM */
1544 /* check if there is a file/dir which has the same name. */
1545 dir_item
= btrfs_lookup_dir_item(NULL
, parent_root
, path
,
1546 btrfs_ino(BTRFS_I(parent_inode
)),
1547 dentry
->d_name
.name
,
1548 dentry
->d_name
.len
, 0);
1549 if (dir_item
!= NULL
&& !IS_ERR(dir_item
)) {
1550 pending
->error
= -EEXIST
;
1551 goto dir_item_existed
;
1552 } else if (IS_ERR(dir_item
)) {
1553 ret
= PTR_ERR(dir_item
);
1554 btrfs_abort_transaction(trans
, ret
);
1557 btrfs_release_path(path
);
1560 * pull in the delayed directory update
1561 * and the delayed inode item
1562 * otherwise we corrupt the FS during
1565 ret
= btrfs_run_delayed_items(trans
);
1566 if (ret
) { /* Transaction aborted */
1567 btrfs_abort_transaction(trans
, ret
);
1571 record_root_in_trans(trans
, root
, 0);
1572 btrfs_set_root_last_snapshot(&root
->root_item
, trans
->transid
);
1573 memcpy(new_root_item
, &root
->root_item
, sizeof(*new_root_item
));
1574 btrfs_check_and_init_root_item(new_root_item
);
1576 root_flags
= btrfs_root_flags(new_root_item
);
1577 if (pending
->readonly
)
1578 root_flags
|= BTRFS_ROOT_SUBVOL_RDONLY
;
1580 root_flags
&= ~BTRFS_ROOT_SUBVOL_RDONLY
;
1581 btrfs_set_root_flags(new_root_item
, root_flags
);
1583 btrfs_set_root_generation_v2(new_root_item
,
1585 generate_random_guid(new_root_item
->uuid
);
1586 memcpy(new_root_item
->parent_uuid
, root
->root_item
.uuid
,
1588 if (!(root_flags
& BTRFS_ROOT_SUBVOL_RDONLY
)) {
1589 memset(new_root_item
->received_uuid
, 0,
1590 sizeof(new_root_item
->received_uuid
));
1591 memset(&new_root_item
->stime
, 0, sizeof(new_root_item
->stime
));
1592 memset(&new_root_item
->rtime
, 0, sizeof(new_root_item
->rtime
));
1593 btrfs_set_root_stransid(new_root_item
, 0);
1594 btrfs_set_root_rtransid(new_root_item
, 0);
1596 btrfs_set_stack_timespec_sec(&new_root_item
->otime
, cur_time
.tv_sec
);
1597 btrfs_set_stack_timespec_nsec(&new_root_item
->otime
, cur_time
.tv_nsec
);
1598 btrfs_set_root_otransid(new_root_item
, trans
->transid
);
1600 old
= btrfs_lock_root_node(root
);
1601 ret
= btrfs_cow_block(trans
, root
, old
, NULL
, 0, &old
);
1603 btrfs_tree_unlock(old
);
1604 free_extent_buffer(old
);
1605 btrfs_abort_transaction(trans
, ret
);
1609 btrfs_set_lock_blocking_write(old
);
1611 ret
= btrfs_copy_root(trans
, root
, old
, &tmp
, objectid
);
1612 /* clean up in any case */
1613 btrfs_tree_unlock(old
);
1614 free_extent_buffer(old
);
1616 btrfs_abort_transaction(trans
, ret
);
1619 /* see comments in should_cow_block() */
1620 set_bit(BTRFS_ROOT_FORCE_COW
, &root
->state
);
1623 btrfs_set_root_node(new_root_item
, tmp
);
1624 /* record when the snapshot was created in key.offset */
1625 key
.offset
= trans
->transid
;
1626 ret
= btrfs_insert_root(trans
, tree_root
, &key
, new_root_item
);
1627 btrfs_tree_unlock(tmp
);
1628 free_extent_buffer(tmp
);
1630 btrfs_abort_transaction(trans
, ret
);
1635 * insert root back/forward references
1637 ret
= btrfs_add_root_ref(trans
, objectid
,
1638 parent_root
->root_key
.objectid
,
1639 btrfs_ino(BTRFS_I(parent_inode
)), index
,
1640 dentry
->d_name
.name
, dentry
->d_name
.len
);
1642 btrfs_abort_transaction(trans
, ret
);
1646 key
.offset
= (u64
)-1;
1647 pending
->snap
= btrfs_get_fs_root(fs_info
, &key
, true);
1648 if (IS_ERR(pending
->snap
)) {
1649 ret
= PTR_ERR(pending
->snap
);
1650 btrfs_abort_transaction(trans
, ret
);
1654 ret
= btrfs_reloc_post_snapshot(trans
, pending
);
1656 btrfs_abort_transaction(trans
, ret
);
1660 ret
= btrfs_run_delayed_refs(trans
, (unsigned long)-1);
1662 btrfs_abort_transaction(trans
, ret
);
1667 * Do special qgroup accounting for snapshot, as we do some qgroup
1668 * snapshot hack to do fast snapshot.
1669 * To co-operate with that hack, we do hack again.
1670 * Or snapshot will be greatly slowed down by a subtree qgroup rescan
1672 ret
= qgroup_account_snapshot(trans
, root
, parent_root
,
1673 pending
->inherit
, objectid
);
1677 ret
= btrfs_insert_dir_item(trans
, dentry
->d_name
.name
,
1678 dentry
->d_name
.len
, BTRFS_I(parent_inode
),
1679 &key
, BTRFS_FT_DIR
, index
);
1680 /* We have check then name at the beginning, so it is impossible. */
1681 BUG_ON(ret
== -EEXIST
|| ret
== -EOVERFLOW
);
1683 btrfs_abort_transaction(trans
, ret
);
1687 btrfs_i_size_write(BTRFS_I(parent_inode
), parent_inode
->i_size
+
1688 dentry
->d_name
.len
* 2);
1689 parent_inode
->i_mtime
= parent_inode
->i_ctime
=
1690 current_time(parent_inode
);
1691 ret
= btrfs_update_inode_fallback(trans
, parent_root
, parent_inode
);
1693 btrfs_abort_transaction(trans
, ret
);
1696 ret
= btrfs_uuid_tree_add(trans
, new_root_item
->uuid
,
1697 BTRFS_UUID_KEY_SUBVOL
,
1700 btrfs_abort_transaction(trans
, ret
);
1703 if (!btrfs_is_empty_uuid(new_root_item
->received_uuid
)) {
1704 ret
= btrfs_uuid_tree_add(trans
, new_root_item
->received_uuid
,
1705 BTRFS_UUID_KEY_RECEIVED_SUBVOL
,
1707 if (ret
&& ret
!= -EEXIST
) {
1708 btrfs_abort_transaction(trans
, ret
);
1713 ret
= btrfs_run_delayed_refs(trans
, (unsigned long)-1);
1715 btrfs_abort_transaction(trans
, ret
);
1720 pending
->error
= ret
;
1722 trans
->block_rsv
= rsv
;
1723 trans
->bytes_reserved
= 0;
1725 btrfs_clear_skip_qgroup(trans
);
1727 kfree(new_root_item
);
1728 pending
->root_item
= NULL
;
1729 btrfs_free_path(path
);
1730 pending
->path
= NULL
;
1736 * create all the snapshots we've scheduled for creation
1738 static noinline
int create_pending_snapshots(struct btrfs_trans_handle
*trans
)
1740 struct btrfs_pending_snapshot
*pending
, *next
;
1741 struct list_head
*head
= &trans
->transaction
->pending_snapshots
;
1744 list_for_each_entry_safe(pending
, next
, head
, list
) {
1745 list_del(&pending
->list
);
1746 ret
= create_pending_snapshot(trans
, pending
);
1753 static void update_super_roots(struct btrfs_fs_info
*fs_info
)
1755 struct btrfs_root_item
*root_item
;
1756 struct btrfs_super_block
*super
;
1758 super
= fs_info
->super_copy
;
1760 root_item
= &fs_info
->chunk_root
->root_item
;
1761 super
->chunk_root
= root_item
->bytenr
;
1762 super
->chunk_root_generation
= root_item
->generation
;
1763 super
->chunk_root_level
= root_item
->level
;
1765 root_item
= &fs_info
->tree_root
->root_item
;
1766 super
->root
= root_item
->bytenr
;
1767 super
->generation
= root_item
->generation
;
1768 super
->root_level
= root_item
->level
;
1769 if (btrfs_test_opt(fs_info
, SPACE_CACHE
))
1770 super
->cache_generation
= root_item
->generation
;
1771 if (test_bit(BTRFS_FS_UPDATE_UUID_TREE_GEN
, &fs_info
->flags
))
1772 super
->uuid_tree_generation
= root_item
->generation
;
1775 int btrfs_transaction_in_commit(struct btrfs_fs_info
*info
)
1777 struct btrfs_transaction
*trans
;
1780 spin_lock(&info
->trans_lock
);
1781 trans
= info
->running_transaction
;
1783 ret
= (trans
->state
>= TRANS_STATE_COMMIT_START
);
1784 spin_unlock(&info
->trans_lock
);
1788 int btrfs_transaction_blocked(struct btrfs_fs_info
*info
)
1790 struct btrfs_transaction
*trans
;
1793 spin_lock(&info
->trans_lock
);
1794 trans
= info
->running_transaction
;
1796 ret
= is_transaction_blocked(trans
);
1797 spin_unlock(&info
->trans_lock
);
1802 * wait for the current transaction commit to start and block subsequent
1805 static void wait_current_trans_commit_start(struct btrfs_fs_info
*fs_info
,
1806 struct btrfs_transaction
*trans
)
1808 wait_event(fs_info
->transaction_blocked_wait
,
1809 trans
->state
>= TRANS_STATE_COMMIT_START
||
1810 TRANS_ABORTED(trans
));
1814 * wait for the current transaction to start and then become unblocked.
1817 static void wait_current_trans_commit_start_and_unblock(
1818 struct btrfs_fs_info
*fs_info
,
1819 struct btrfs_transaction
*trans
)
1821 wait_event(fs_info
->transaction_wait
,
1822 trans
->state
>= TRANS_STATE_UNBLOCKED
||
1823 TRANS_ABORTED(trans
));
1827 * commit transactions asynchronously. once btrfs_commit_transaction_async
1828 * returns, any subsequent transaction will not be allowed to join.
1830 struct btrfs_async_commit
{
1831 struct btrfs_trans_handle
*newtrans
;
1832 struct work_struct work
;
1835 static void do_async_commit(struct work_struct
*work
)
1837 struct btrfs_async_commit
*ac
=
1838 container_of(work
, struct btrfs_async_commit
, work
);
1841 * We've got freeze protection passed with the transaction.
1842 * Tell lockdep about it.
1844 if (ac
->newtrans
->type
& __TRANS_FREEZABLE
)
1845 __sb_writers_acquired(ac
->newtrans
->fs_info
->sb
, SB_FREEZE_FS
);
1847 current
->journal_info
= ac
->newtrans
;
1849 btrfs_commit_transaction(ac
->newtrans
);
1853 int btrfs_commit_transaction_async(struct btrfs_trans_handle
*trans
,
1854 int wait_for_unblock
)
1856 struct btrfs_fs_info
*fs_info
= trans
->fs_info
;
1857 struct btrfs_async_commit
*ac
;
1858 struct btrfs_transaction
*cur_trans
;
1860 ac
= kmalloc(sizeof(*ac
), GFP_NOFS
);
1864 INIT_WORK(&ac
->work
, do_async_commit
);
1865 ac
->newtrans
= btrfs_join_transaction(trans
->root
);
1866 if (IS_ERR(ac
->newtrans
)) {
1867 int err
= PTR_ERR(ac
->newtrans
);
1872 /* take transaction reference */
1873 cur_trans
= trans
->transaction
;
1874 refcount_inc(&cur_trans
->use_count
);
1876 btrfs_end_transaction(trans
);
1879 * Tell lockdep we've released the freeze rwsem, since the
1880 * async commit thread will be the one to unlock it.
1882 if (ac
->newtrans
->type
& __TRANS_FREEZABLE
)
1883 __sb_writers_release(fs_info
->sb
, SB_FREEZE_FS
);
1885 schedule_work(&ac
->work
);
1887 /* wait for transaction to start and unblock */
1888 if (wait_for_unblock
)
1889 wait_current_trans_commit_start_and_unblock(fs_info
, cur_trans
);
1891 wait_current_trans_commit_start(fs_info
, cur_trans
);
1893 if (current
->journal_info
== trans
)
1894 current
->journal_info
= NULL
;
1896 btrfs_put_transaction(cur_trans
);
1901 static void cleanup_transaction(struct btrfs_trans_handle
*trans
, int err
)
1903 struct btrfs_fs_info
*fs_info
= trans
->fs_info
;
1904 struct btrfs_transaction
*cur_trans
= trans
->transaction
;
1906 WARN_ON(refcount_read(&trans
->use_count
) > 1);
1908 btrfs_abort_transaction(trans
, err
);
1910 spin_lock(&fs_info
->trans_lock
);
1913 * If the transaction is removed from the list, it means this
1914 * transaction has been committed successfully, so it is impossible
1915 * to call the cleanup function.
1917 BUG_ON(list_empty(&cur_trans
->list
));
1919 list_del_init(&cur_trans
->list
);
1920 if (cur_trans
== fs_info
->running_transaction
) {
1921 cur_trans
->state
= TRANS_STATE_COMMIT_DOING
;
1922 spin_unlock(&fs_info
->trans_lock
);
1923 wait_event(cur_trans
->writer_wait
,
1924 atomic_read(&cur_trans
->num_writers
) == 1);
1926 spin_lock(&fs_info
->trans_lock
);
1928 spin_unlock(&fs_info
->trans_lock
);
1930 btrfs_cleanup_one_transaction(trans
->transaction
, fs_info
);
1932 spin_lock(&fs_info
->trans_lock
);
1933 if (cur_trans
== fs_info
->running_transaction
)
1934 fs_info
->running_transaction
= NULL
;
1935 spin_unlock(&fs_info
->trans_lock
);
1937 if (trans
->type
& __TRANS_FREEZABLE
)
1938 sb_end_intwrite(fs_info
->sb
);
1939 btrfs_put_transaction(cur_trans
);
1940 btrfs_put_transaction(cur_trans
);
1942 trace_btrfs_transaction_commit(trans
->root
);
1944 if (current
->journal_info
== trans
)
1945 current
->journal_info
= NULL
;
1946 btrfs_scrub_cancel(fs_info
);
1948 kmem_cache_free(btrfs_trans_handle_cachep
, trans
);
1952 * Release reserved delayed ref space of all pending block groups of the
1953 * transaction and remove them from the list
1955 static void btrfs_cleanup_pending_block_groups(struct btrfs_trans_handle
*trans
)
1957 struct btrfs_fs_info
*fs_info
= trans
->fs_info
;
1958 struct btrfs_block_group
*block_group
, *tmp
;
1960 list_for_each_entry_safe(block_group
, tmp
, &trans
->new_bgs
, bg_list
) {
1961 btrfs_delayed_refs_rsv_release(fs_info
, 1);
1962 list_del_init(&block_group
->bg_list
);
1966 static inline int btrfs_start_delalloc_flush(struct btrfs_trans_handle
*trans
)
1968 struct btrfs_fs_info
*fs_info
= trans
->fs_info
;
1971 * We use writeback_inodes_sb here because if we used
1972 * btrfs_start_delalloc_roots we would deadlock with fs freeze.
1973 * Currently are holding the fs freeze lock, if we do an async flush
1974 * we'll do btrfs_join_transaction() and deadlock because we need to
1975 * wait for the fs freeze lock. Using the direct flushing we benefit
1976 * from already being in a transaction and our join_transaction doesn't
1977 * have to re-take the fs freeze lock.
1979 if (btrfs_test_opt(fs_info
, FLUSHONCOMMIT
)) {
1980 writeback_inodes_sb(fs_info
->sb
, WB_REASON_SYNC
);
1982 struct btrfs_pending_snapshot
*pending
;
1983 struct list_head
*head
= &trans
->transaction
->pending_snapshots
;
1986 * Flush dellaloc for any root that is going to be snapshotted.
1987 * This is done to avoid a corrupted version of files, in the
1988 * snapshots, that had both buffered and direct IO writes (even
1989 * if they were done sequentially) due to an unordered update of
1990 * the inode's size on disk.
1992 list_for_each_entry(pending
, head
, list
) {
1995 ret
= btrfs_start_delalloc_snapshot(pending
->root
);
2003 static inline void btrfs_wait_delalloc_flush(struct btrfs_trans_handle
*trans
)
2005 struct btrfs_fs_info
*fs_info
= trans
->fs_info
;
2007 if (btrfs_test_opt(fs_info
, FLUSHONCOMMIT
)) {
2008 btrfs_wait_ordered_roots(fs_info
, U64_MAX
, 0, (u64
)-1);
2010 struct btrfs_pending_snapshot
*pending
;
2011 struct list_head
*head
= &trans
->transaction
->pending_snapshots
;
2014 * Wait for any dellaloc that we started previously for the roots
2015 * that are going to be snapshotted. This is to avoid a corrupted
2016 * version of files in the snapshots that had both buffered and
2017 * direct IO writes (even if they were done sequentially).
2019 list_for_each_entry(pending
, head
, list
)
2020 btrfs_wait_ordered_extents(pending
->root
,
2021 U64_MAX
, 0, U64_MAX
);
2025 int btrfs_commit_transaction(struct btrfs_trans_handle
*trans
)
2027 struct btrfs_fs_info
*fs_info
= trans
->fs_info
;
2028 struct btrfs_transaction
*cur_trans
= trans
->transaction
;
2029 struct btrfs_transaction
*prev_trans
= NULL
;
2032 ASSERT(refcount_read(&trans
->use_count
) == 1);
2035 * Some places just start a transaction to commit it. We need to make
2036 * sure that if this commit fails that the abort code actually marks the
2037 * transaction as failed, so set trans->dirty to make the abort code do
2040 trans
->dirty
= true;
2042 /* Stop the commit early if ->aborted is set */
2043 if (TRANS_ABORTED(cur_trans
)) {
2044 ret
= cur_trans
->aborted
;
2045 btrfs_end_transaction(trans
);
2049 btrfs_trans_release_metadata(trans
);
2050 trans
->block_rsv
= NULL
;
2052 /* make a pass through all the delayed refs we have so far
2053 * any runnings procs may add more while we are here
2055 ret
= btrfs_run_delayed_refs(trans
, 0);
2057 btrfs_end_transaction(trans
);
2061 cur_trans
= trans
->transaction
;
2064 * set the flushing flag so procs in this transaction have to
2065 * start sending their work down.
2067 cur_trans
->delayed_refs
.flushing
= 1;
2070 btrfs_create_pending_block_groups(trans
);
2072 ret
= btrfs_run_delayed_refs(trans
, 0);
2074 btrfs_end_transaction(trans
);
2078 if (!test_bit(BTRFS_TRANS_DIRTY_BG_RUN
, &cur_trans
->flags
)) {
2081 /* this mutex is also taken before trying to set
2082 * block groups readonly. We need to make sure
2083 * that nobody has set a block group readonly
2084 * after a extents from that block group have been
2085 * allocated for cache files. btrfs_set_block_group_ro
2086 * will wait for the transaction to commit if it
2087 * finds BTRFS_TRANS_DIRTY_BG_RUN set.
2089 * The BTRFS_TRANS_DIRTY_BG_RUN flag is also used to make sure
2090 * only one process starts all the block group IO. It wouldn't
2091 * hurt to have more than one go through, but there's no
2092 * real advantage to it either.
2094 mutex_lock(&fs_info
->ro_block_group_mutex
);
2095 if (!test_and_set_bit(BTRFS_TRANS_DIRTY_BG_RUN
,
2098 mutex_unlock(&fs_info
->ro_block_group_mutex
);
2101 ret
= btrfs_start_dirty_block_groups(trans
);
2103 btrfs_end_transaction(trans
);
2109 spin_lock(&fs_info
->trans_lock
);
2110 if (cur_trans
->state
>= TRANS_STATE_COMMIT_START
) {
2111 spin_unlock(&fs_info
->trans_lock
);
2112 refcount_inc(&cur_trans
->use_count
);
2113 ret
= btrfs_end_transaction(trans
);
2115 wait_for_commit(cur_trans
);
2117 if (TRANS_ABORTED(cur_trans
))
2118 ret
= cur_trans
->aborted
;
2120 btrfs_put_transaction(cur_trans
);
2125 cur_trans
->state
= TRANS_STATE_COMMIT_START
;
2126 wake_up(&fs_info
->transaction_blocked_wait
);
2128 if (cur_trans
->list
.prev
!= &fs_info
->trans_list
) {
2129 prev_trans
= list_entry(cur_trans
->list
.prev
,
2130 struct btrfs_transaction
, list
);
2131 if (prev_trans
->state
!= TRANS_STATE_COMPLETED
) {
2132 refcount_inc(&prev_trans
->use_count
);
2133 spin_unlock(&fs_info
->trans_lock
);
2135 wait_for_commit(prev_trans
);
2136 ret
= READ_ONCE(prev_trans
->aborted
);
2138 btrfs_put_transaction(prev_trans
);
2140 goto cleanup_transaction
;
2142 spin_unlock(&fs_info
->trans_lock
);
2145 spin_unlock(&fs_info
->trans_lock
);
2147 * The previous transaction was aborted and was already removed
2148 * from the list of transactions at fs_info->trans_list. So we
2149 * abort to prevent writing a new superblock that reflects a
2150 * corrupt state (pointing to trees with unwritten nodes/leafs).
2152 if (test_bit(BTRFS_FS_STATE_TRANS_ABORTED
, &fs_info
->fs_state
)) {
2154 goto cleanup_transaction
;
2158 extwriter_counter_dec(cur_trans
, trans
->type
);
2160 ret
= btrfs_start_delalloc_flush(trans
);
2162 goto cleanup_transaction
;
2164 ret
= btrfs_run_delayed_items(trans
);
2166 goto cleanup_transaction
;
2168 wait_event(cur_trans
->writer_wait
,
2169 extwriter_counter_read(cur_trans
) == 0);
2171 /* some pending stuffs might be added after the previous flush. */
2172 ret
= btrfs_run_delayed_items(trans
);
2174 goto cleanup_transaction
;
2176 btrfs_wait_delalloc_flush(trans
);
2178 btrfs_scrub_pause(fs_info
);
2180 * Ok now we need to make sure to block out any other joins while we
2181 * commit the transaction. We could have started a join before setting
2182 * COMMIT_DOING so make sure to wait for num_writers to == 1 again.
2184 spin_lock(&fs_info
->trans_lock
);
2185 cur_trans
->state
= TRANS_STATE_COMMIT_DOING
;
2186 spin_unlock(&fs_info
->trans_lock
);
2187 wait_event(cur_trans
->writer_wait
,
2188 atomic_read(&cur_trans
->num_writers
) == 1);
2190 if (TRANS_ABORTED(cur_trans
)) {
2191 ret
= cur_trans
->aborted
;
2192 goto scrub_continue
;
2195 * the reloc mutex makes sure that we stop
2196 * the balancing code from coming in and moving
2197 * extents around in the middle of the commit
2199 mutex_lock(&fs_info
->reloc_mutex
);
2202 * We needn't worry about the delayed items because we will
2203 * deal with them in create_pending_snapshot(), which is the
2204 * core function of the snapshot creation.
2206 ret
= create_pending_snapshots(trans
);
2211 * We insert the dir indexes of the snapshots and update the inode
2212 * of the snapshots' parents after the snapshot creation, so there
2213 * are some delayed items which are not dealt with. Now deal with
2216 * We needn't worry that this operation will corrupt the snapshots,
2217 * because all the tree which are snapshoted will be forced to COW
2218 * the nodes and leaves.
2220 ret
= btrfs_run_delayed_items(trans
);
2224 ret
= btrfs_run_delayed_refs(trans
, (unsigned long)-1);
2229 * make sure none of the code above managed to slip in a
2232 btrfs_assert_delayed_root_empty(fs_info
);
2234 WARN_ON(cur_trans
!= trans
->transaction
);
2236 /* btrfs_commit_tree_roots is responsible for getting the
2237 * various roots consistent with each other. Every pointer
2238 * in the tree of tree roots has to point to the most up to date
2239 * root for every subvolume and other tree. So, we have to keep
2240 * the tree logging code from jumping in and changing any
2243 * At this point in the commit, there can't be any tree-log
2244 * writers, but a little lower down we drop the trans mutex
2245 * and let new people in. By holding the tree_log_mutex
2246 * from now until after the super is written, we avoid races
2247 * with the tree-log code.
2249 mutex_lock(&fs_info
->tree_log_mutex
);
2251 ret
= commit_fs_roots(trans
);
2253 goto unlock_tree_log
;
2256 * Since the transaction is done, we can apply the pending changes
2257 * before the next transaction.
2259 btrfs_apply_pending_changes(fs_info
);
2261 /* commit_fs_roots gets rid of all the tree log roots, it is now
2262 * safe to free the root of tree log roots
2264 btrfs_free_log_root_tree(trans
, fs_info
);
2267 * commit_fs_roots() can call btrfs_save_ino_cache(), which generates
2268 * new delayed refs. Must handle them or qgroup can be wrong.
2270 ret
= btrfs_run_delayed_refs(trans
, (unsigned long)-1);
2272 goto unlock_tree_log
;
2275 * Since fs roots are all committed, we can get a quite accurate
2276 * new_roots. So let's do quota accounting.
2278 ret
= btrfs_qgroup_account_extents(trans
);
2280 goto unlock_tree_log
;
2282 ret
= commit_cowonly_roots(trans
);
2284 goto unlock_tree_log
;
2287 * The tasks which save the space cache and inode cache may also
2288 * update ->aborted, check it.
2290 if (TRANS_ABORTED(cur_trans
)) {
2291 ret
= cur_trans
->aborted
;
2292 goto unlock_tree_log
;
2295 btrfs_prepare_extent_commit(fs_info
);
2297 cur_trans
= fs_info
->running_transaction
;
2299 btrfs_set_root_node(&fs_info
->tree_root
->root_item
,
2300 fs_info
->tree_root
->node
);
2301 list_add_tail(&fs_info
->tree_root
->dirty_list
,
2302 &cur_trans
->switch_commits
);
2304 btrfs_set_root_node(&fs_info
->chunk_root
->root_item
,
2305 fs_info
->chunk_root
->node
);
2306 list_add_tail(&fs_info
->chunk_root
->dirty_list
,
2307 &cur_trans
->switch_commits
);
2309 switch_commit_roots(trans
);
2311 ASSERT(list_empty(&cur_trans
->dirty_bgs
));
2312 ASSERT(list_empty(&cur_trans
->io_bgs
));
2313 update_super_roots(fs_info
);
2315 btrfs_set_super_log_root(fs_info
->super_copy
, 0);
2316 btrfs_set_super_log_root_level(fs_info
->super_copy
, 0);
2317 memcpy(fs_info
->super_for_commit
, fs_info
->super_copy
,
2318 sizeof(*fs_info
->super_copy
));
2320 btrfs_commit_device_sizes(cur_trans
);
2322 clear_bit(BTRFS_FS_LOG1_ERR
, &fs_info
->flags
);
2323 clear_bit(BTRFS_FS_LOG2_ERR
, &fs_info
->flags
);
2325 btrfs_trans_release_chunk_metadata(trans
);
2327 spin_lock(&fs_info
->trans_lock
);
2328 cur_trans
->state
= TRANS_STATE_UNBLOCKED
;
2329 fs_info
->running_transaction
= NULL
;
2330 spin_unlock(&fs_info
->trans_lock
);
2331 mutex_unlock(&fs_info
->reloc_mutex
);
2333 wake_up(&fs_info
->transaction_wait
);
2335 ret
= btrfs_write_and_wait_transaction(trans
);
2337 btrfs_handle_fs_error(fs_info
, ret
,
2338 "Error while writing out transaction");
2340 * reloc_mutex has been unlocked, tree_log_mutex is still held
2341 * but we can't jump to unlock_tree_log causing double unlock
2343 mutex_unlock(&fs_info
->tree_log_mutex
);
2344 goto scrub_continue
;
2347 ret
= write_all_supers(fs_info
, 0);
2349 * the super is written, we can safely allow the tree-loggers
2350 * to go about their business
2352 mutex_unlock(&fs_info
->tree_log_mutex
);
2354 goto scrub_continue
;
2356 btrfs_finish_extent_commit(trans
);
2358 if (test_bit(BTRFS_TRANS_HAVE_FREE_BGS
, &cur_trans
->flags
))
2359 btrfs_clear_space_info_full(fs_info
);
2361 fs_info
->last_trans_committed
= cur_trans
->transid
;
2363 * We needn't acquire the lock here because there is no other task
2364 * which can change it.
2366 cur_trans
->state
= TRANS_STATE_COMPLETED
;
2367 wake_up(&cur_trans
->commit_wait
);
2368 clear_bit(BTRFS_FS_NEED_ASYNC_COMMIT
, &fs_info
->flags
);
2370 spin_lock(&fs_info
->trans_lock
);
2371 list_del_init(&cur_trans
->list
);
2372 spin_unlock(&fs_info
->trans_lock
);
2374 btrfs_put_transaction(cur_trans
);
2375 btrfs_put_transaction(cur_trans
);
2377 if (trans
->type
& __TRANS_FREEZABLE
)
2378 sb_end_intwrite(fs_info
->sb
);
2380 trace_btrfs_transaction_commit(trans
->root
);
2382 btrfs_scrub_continue(fs_info
);
2384 if (current
->journal_info
== trans
)
2385 current
->journal_info
= NULL
;
2387 kmem_cache_free(btrfs_trans_handle_cachep
, trans
);
2392 mutex_unlock(&fs_info
->tree_log_mutex
);
2394 mutex_unlock(&fs_info
->reloc_mutex
);
2396 btrfs_scrub_continue(fs_info
);
2397 cleanup_transaction
:
2398 btrfs_trans_release_metadata(trans
);
2399 btrfs_cleanup_pending_block_groups(trans
);
2400 btrfs_trans_release_chunk_metadata(trans
);
2401 trans
->block_rsv
= NULL
;
2402 btrfs_warn(fs_info
, "Skipping commit of aborted transaction.");
2403 if (current
->journal_info
== trans
)
2404 current
->journal_info
= NULL
;
2405 cleanup_transaction(trans
, ret
);
2411 * return < 0 if error
2412 * 0 if there are no more dead_roots at the time of call
2413 * 1 there are more to be processed, call me again
2415 * The return value indicates there are certainly more snapshots to delete, but
2416 * if there comes a new one during processing, it may return 0. We don't mind,
2417 * because btrfs_commit_super will poke cleaner thread and it will process it a
2418 * few seconds later.
2420 int btrfs_clean_one_deleted_snapshot(struct btrfs_root
*root
)
2423 struct btrfs_fs_info
*fs_info
= root
->fs_info
;
2425 spin_lock(&fs_info
->trans_lock
);
2426 if (list_empty(&fs_info
->dead_roots
)) {
2427 spin_unlock(&fs_info
->trans_lock
);
2430 root
= list_first_entry(&fs_info
->dead_roots
,
2431 struct btrfs_root
, root_list
);
2432 list_del_init(&root
->root_list
);
2433 spin_unlock(&fs_info
->trans_lock
);
2435 btrfs_debug(fs_info
, "cleaner removing %llu", root
->root_key
.objectid
);
2437 btrfs_kill_all_delayed_nodes(root
);
2438 if (root
->ino_cache_inode
) {
2439 iput(root
->ino_cache_inode
);
2440 root
->ino_cache_inode
= NULL
;
2443 if (btrfs_header_backref_rev(root
->node
) <
2444 BTRFS_MIXED_BACKREF_REV
)
2445 ret
= btrfs_drop_snapshot(root
, 0, 0);
2447 ret
= btrfs_drop_snapshot(root
, 1, 0);
2449 btrfs_put_root(root
);
2450 return (ret
< 0) ? 0 : 1;
2453 void btrfs_apply_pending_changes(struct btrfs_fs_info
*fs_info
)
2458 prev
= xchg(&fs_info
->pending_changes
, 0);
2462 bit
= 1 << BTRFS_PENDING_SET_INODE_MAP_CACHE
;
2464 btrfs_set_opt(fs_info
->mount_opt
, INODE_MAP_CACHE
);
2467 bit
= 1 << BTRFS_PENDING_CLEAR_INODE_MAP_CACHE
;
2469 btrfs_clear_opt(fs_info
->mount_opt
, INODE_MAP_CACHE
);
2472 bit
= 1 << BTRFS_PENDING_COMMIT
;
2474 btrfs_debug(fs_info
, "pending commit done");
2479 "unknown pending changes left 0x%lx, ignoring", prev
);