2 * Copyright (C) 2007 Oracle. All rights reserved.
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.
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.
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.
20 #include <linux/slab.h>
21 #include <linux/sched.h>
22 #include <linux/writeback.h>
23 #include <linux/pagemap.h>
24 #include <linux/blkdev.h>
27 #include "transaction.h"
30 #include "inode-map.h"
32 #define BTRFS_ROOT_TRANS_TAG 0
34 void put_transaction(struct btrfs_transaction
*transaction
)
36 WARN_ON(atomic_read(&transaction
->use_count
) == 0);
37 if (atomic_dec_and_test(&transaction
->use_count
)) {
38 BUG_ON(!list_empty(&transaction
->list
));
39 WARN_ON(transaction
->delayed_refs
.root
.rb_node
);
40 WARN_ON(!list_empty(&transaction
->delayed_refs
.seq_head
));
41 memset(transaction
, 0, sizeof(*transaction
));
42 kmem_cache_free(btrfs_transaction_cachep
, transaction
);
46 static noinline
void switch_commit_root(struct btrfs_root
*root
)
48 free_extent_buffer(root
->commit_root
);
49 root
->commit_root
= btrfs_root_node(root
);
53 * either allocate a new transaction or hop into the existing one
55 static noinline
int join_transaction(struct btrfs_root
*root
, int nofail
)
57 struct btrfs_transaction
*cur_trans
;
59 spin_lock(&root
->fs_info
->trans_lock
);
61 /* The file system has been taken offline. No new transactions. */
62 if (root
->fs_info
->fs_state
& BTRFS_SUPER_FLAG_ERROR
) {
63 spin_unlock(&root
->fs_info
->trans_lock
);
67 if (root
->fs_info
->trans_no_join
) {
69 spin_unlock(&root
->fs_info
->trans_lock
);
74 cur_trans
= root
->fs_info
->running_transaction
;
76 if (cur_trans
->aborted
)
77 return cur_trans
->aborted
;
78 atomic_inc(&cur_trans
->use_count
);
79 atomic_inc(&cur_trans
->num_writers
);
80 cur_trans
->num_joined
++;
81 spin_unlock(&root
->fs_info
->trans_lock
);
84 spin_unlock(&root
->fs_info
->trans_lock
);
86 cur_trans
= kmem_cache_alloc(btrfs_transaction_cachep
, GFP_NOFS
);
90 spin_lock(&root
->fs_info
->trans_lock
);
91 if (root
->fs_info
->running_transaction
) {
93 * someone started a transaction after we unlocked. Make sure
94 * to redo the trans_no_join checks above
96 kmem_cache_free(btrfs_transaction_cachep
, cur_trans
);
97 cur_trans
= root
->fs_info
->running_transaction
;
101 atomic_set(&cur_trans
->num_writers
, 1);
102 cur_trans
->num_joined
= 0;
103 init_waitqueue_head(&cur_trans
->writer_wait
);
104 init_waitqueue_head(&cur_trans
->commit_wait
);
105 cur_trans
->in_commit
= 0;
106 cur_trans
->blocked
= 0;
108 * One for this trans handle, one so it will live on until we
109 * commit the transaction.
111 atomic_set(&cur_trans
->use_count
, 2);
112 cur_trans
->commit_done
= 0;
113 cur_trans
->start_time
= get_seconds();
115 cur_trans
->delayed_refs
.root
= RB_ROOT
;
116 cur_trans
->delayed_refs
.num_entries
= 0;
117 cur_trans
->delayed_refs
.num_heads_ready
= 0;
118 cur_trans
->delayed_refs
.num_heads
= 0;
119 cur_trans
->delayed_refs
.flushing
= 0;
120 cur_trans
->delayed_refs
.run_delayed_start
= 0;
121 cur_trans
->delayed_refs
.seq
= 1;
122 init_waitqueue_head(&cur_trans
->delayed_refs
.seq_wait
);
123 spin_lock_init(&cur_trans
->commit_lock
);
124 spin_lock_init(&cur_trans
->delayed_refs
.lock
);
125 INIT_LIST_HEAD(&cur_trans
->delayed_refs
.seq_head
);
127 INIT_LIST_HEAD(&cur_trans
->pending_snapshots
);
128 list_add_tail(&cur_trans
->list
, &root
->fs_info
->trans_list
);
129 extent_io_tree_init(&cur_trans
->dirty_pages
,
130 root
->fs_info
->btree_inode
->i_mapping
);
131 root
->fs_info
->generation
++;
132 cur_trans
->transid
= root
->fs_info
->generation
;
133 root
->fs_info
->running_transaction
= cur_trans
;
134 cur_trans
->aborted
= 0;
135 spin_unlock(&root
->fs_info
->trans_lock
);
141 * this does all the record keeping required to make sure that a reference
142 * counted root is properly recorded in a given transaction. This is required
143 * to make sure the old root from before we joined the transaction is deleted
144 * when the transaction commits
146 static int record_root_in_trans(struct btrfs_trans_handle
*trans
,
147 struct btrfs_root
*root
)
149 if (root
->ref_cows
&& root
->last_trans
< trans
->transid
) {
150 WARN_ON(root
== root
->fs_info
->extent_root
);
151 WARN_ON(root
->commit_root
!= root
->node
);
154 * see below for in_trans_setup usage rules
155 * we have the reloc mutex held now, so there
156 * is only one writer in this function
158 root
->in_trans_setup
= 1;
160 /* make sure readers find in_trans_setup before
161 * they find our root->last_trans update
165 spin_lock(&root
->fs_info
->fs_roots_radix_lock
);
166 if (root
->last_trans
== trans
->transid
) {
167 spin_unlock(&root
->fs_info
->fs_roots_radix_lock
);
170 radix_tree_tag_set(&root
->fs_info
->fs_roots_radix
,
171 (unsigned long)root
->root_key
.objectid
,
172 BTRFS_ROOT_TRANS_TAG
);
173 spin_unlock(&root
->fs_info
->fs_roots_radix_lock
);
174 root
->last_trans
= trans
->transid
;
176 /* this is pretty tricky. We don't want to
177 * take the relocation lock in btrfs_record_root_in_trans
178 * unless we're really doing the first setup for this root in
181 * Normally we'd use root->last_trans as a flag to decide
182 * if we want to take the expensive mutex.
184 * But, we have to set root->last_trans before we
185 * init the relocation root, otherwise, we trip over warnings
186 * in ctree.c. The solution used here is to flag ourselves
187 * with root->in_trans_setup. When this is 1, we're still
188 * fixing up the reloc trees and everyone must wait.
190 * When this is zero, they can trust root->last_trans and fly
191 * through btrfs_record_root_in_trans without having to take the
192 * lock. smp_wmb() makes sure that all the writes above are
193 * done before we pop in the zero below
195 btrfs_init_reloc_root(trans
, root
);
197 root
->in_trans_setup
= 0;
203 int btrfs_record_root_in_trans(struct btrfs_trans_handle
*trans
,
204 struct btrfs_root
*root
)
210 * see record_root_in_trans for comments about in_trans_setup usage
214 if (root
->last_trans
== trans
->transid
&&
215 !root
->in_trans_setup
)
218 mutex_lock(&root
->fs_info
->reloc_mutex
);
219 record_root_in_trans(trans
, root
);
220 mutex_unlock(&root
->fs_info
->reloc_mutex
);
225 /* wait for commit against the current transaction to become unblocked
226 * when this is done, it is safe to start a new transaction, but the current
227 * transaction might not be fully on disk.
229 static void wait_current_trans(struct btrfs_root
*root
)
231 struct btrfs_transaction
*cur_trans
;
233 spin_lock(&root
->fs_info
->trans_lock
);
234 cur_trans
= root
->fs_info
->running_transaction
;
235 if (cur_trans
&& cur_trans
->blocked
) {
236 atomic_inc(&cur_trans
->use_count
);
237 spin_unlock(&root
->fs_info
->trans_lock
);
239 wait_event(root
->fs_info
->transaction_wait
,
240 !cur_trans
->blocked
);
241 put_transaction(cur_trans
);
243 spin_unlock(&root
->fs_info
->trans_lock
);
247 enum btrfs_trans_type
{
254 static int may_wait_transaction(struct btrfs_root
*root
, int type
)
256 if (root
->fs_info
->log_root_recovering
)
259 if (type
== TRANS_USERSPACE
)
262 if (type
== TRANS_START
&&
263 !atomic_read(&root
->fs_info
->open_ioctl_trans
))
269 static struct btrfs_trans_handle
*start_transaction(struct btrfs_root
*root
,
270 u64 num_items
, int type
)
272 struct btrfs_trans_handle
*h
;
273 struct btrfs_transaction
*cur_trans
;
277 if (root
->fs_info
->fs_state
& BTRFS_SUPER_FLAG_ERROR
)
278 return ERR_PTR(-EROFS
);
280 if (current
->journal_info
) {
281 WARN_ON(type
!= TRANS_JOIN
&& type
!= TRANS_JOIN_NOLOCK
);
282 h
= current
->journal_info
;
284 h
->orig_rsv
= h
->block_rsv
;
290 * Do the reservation before we join the transaction so we can do all
291 * the appropriate flushing if need be.
293 if (num_items
> 0 && root
!= root
->fs_info
->chunk_root
) {
294 num_bytes
= btrfs_calc_trans_metadata_size(root
, num_items
);
295 ret
= btrfs_block_rsv_add(root
,
296 &root
->fs_info
->trans_block_rsv
,
302 h
= kmem_cache_alloc(btrfs_trans_handle_cachep
, GFP_NOFS
);
304 return ERR_PTR(-ENOMEM
);
306 if (may_wait_transaction(root
, type
))
307 wait_current_trans(root
);
310 ret
= join_transaction(root
, type
== TRANS_JOIN_NOLOCK
);
312 wait_current_trans(root
);
313 } while (ret
== -EBUSY
);
316 kmem_cache_free(btrfs_trans_handle_cachep
, h
);
320 cur_trans
= root
->fs_info
->running_transaction
;
322 h
->transid
= cur_trans
->transid
;
323 h
->transaction
= cur_trans
;
325 h
->bytes_reserved
= 0;
326 h
->delayed_ref_updates
= 0;
333 if (cur_trans
->blocked
&& may_wait_transaction(root
, type
)) {
334 btrfs_commit_transaction(h
, root
);
339 trace_btrfs_space_reservation(root
->fs_info
, "transaction",
340 h
->transid
, num_bytes
, 1);
341 h
->block_rsv
= &root
->fs_info
->trans_block_rsv
;
342 h
->bytes_reserved
= num_bytes
;
346 btrfs_record_root_in_trans(h
, root
);
348 if (!current
->journal_info
&& type
!= TRANS_USERSPACE
)
349 current
->journal_info
= h
;
353 struct btrfs_trans_handle
*btrfs_start_transaction(struct btrfs_root
*root
,
356 return start_transaction(root
, num_items
, TRANS_START
);
358 struct btrfs_trans_handle
*btrfs_join_transaction(struct btrfs_root
*root
)
360 return start_transaction(root
, 0, TRANS_JOIN
);
363 struct btrfs_trans_handle
*btrfs_join_transaction_nolock(struct btrfs_root
*root
)
365 return start_transaction(root
, 0, TRANS_JOIN_NOLOCK
);
368 struct btrfs_trans_handle
*btrfs_start_ioctl_transaction(struct btrfs_root
*root
)
370 return start_transaction(root
, 0, TRANS_USERSPACE
);
373 /* wait for a transaction commit to be fully complete */
374 static noinline
void wait_for_commit(struct btrfs_root
*root
,
375 struct btrfs_transaction
*commit
)
377 wait_event(commit
->commit_wait
, commit
->commit_done
);
380 int btrfs_wait_for_commit(struct btrfs_root
*root
, u64 transid
)
382 struct btrfs_transaction
*cur_trans
= NULL
, *t
;
387 if (transid
<= root
->fs_info
->last_trans_committed
)
390 /* find specified transaction */
391 spin_lock(&root
->fs_info
->trans_lock
);
392 list_for_each_entry(t
, &root
->fs_info
->trans_list
, list
) {
393 if (t
->transid
== transid
) {
395 atomic_inc(&cur_trans
->use_count
);
398 if (t
->transid
> transid
)
401 spin_unlock(&root
->fs_info
->trans_lock
);
404 goto out
; /* bad transid */
406 /* find newest transaction that is committing | committed */
407 spin_lock(&root
->fs_info
->trans_lock
);
408 list_for_each_entry_reverse(t
, &root
->fs_info
->trans_list
,
414 atomic_inc(&cur_trans
->use_count
);
418 spin_unlock(&root
->fs_info
->trans_lock
);
420 goto out
; /* nothing committing|committed */
423 wait_for_commit(root
, cur_trans
);
425 put_transaction(cur_trans
);
431 void btrfs_throttle(struct btrfs_root
*root
)
433 if (!atomic_read(&root
->fs_info
->open_ioctl_trans
))
434 wait_current_trans(root
);
437 static int should_end_transaction(struct btrfs_trans_handle
*trans
,
438 struct btrfs_root
*root
)
442 ret
= btrfs_block_rsv_check(root
, &root
->fs_info
->global_block_rsv
, 5);
446 int btrfs_should_end_transaction(struct btrfs_trans_handle
*trans
,
447 struct btrfs_root
*root
)
449 struct btrfs_transaction
*cur_trans
= trans
->transaction
;
450 struct btrfs_block_rsv
*rsv
= trans
->block_rsv
;
455 if (cur_trans
->blocked
|| cur_trans
->delayed_refs
.flushing
)
459 * We need to do this in case we're deleting csums so the global block
460 * rsv get's used instead of the csum block rsv.
462 trans
->block_rsv
= NULL
;
464 updates
= trans
->delayed_ref_updates
;
465 trans
->delayed_ref_updates
= 0;
467 err
= btrfs_run_delayed_refs(trans
, root
, updates
);
468 if (err
) /* Error code will also eval true */
472 trans
->block_rsv
= rsv
;
474 return should_end_transaction(trans
, root
);
477 static int __btrfs_end_transaction(struct btrfs_trans_handle
*trans
,
478 struct btrfs_root
*root
, int throttle
, int lock
)
480 struct btrfs_transaction
*cur_trans
= trans
->transaction
;
481 struct btrfs_fs_info
*info
= root
->fs_info
;
484 if (--trans
->use_count
) {
485 trans
->block_rsv
= trans
->orig_rsv
;
489 btrfs_trans_release_metadata(trans
, root
);
490 trans
->block_rsv
= NULL
;
492 unsigned long cur
= trans
->delayed_ref_updates
;
493 trans
->delayed_ref_updates
= 0;
495 trans
->transaction
->delayed_refs
.num_heads_ready
> 64) {
496 trans
->delayed_ref_updates
= 0;
497 btrfs_run_delayed_refs(trans
, root
, cur
);
504 if (lock
&& !atomic_read(&root
->fs_info
->open_ioctl_trans
) &&
505 should_end_transaction(trans
, root
)) {
506 trans
->transaction
->blocked
= 1;
510 if (lock
&& cur_trans
->blocked
&& !cur_trans
->in_commit
) {
513 * We may race with somebody else here so end up having
514 * to call end_transaction on ourselves again, so inc
518 return btrfs_commit_transaction(trans
, root
);
520 wake_up_process(info
->transaction_kthread
);
524 WARN_ON(cur_trans
!= info
->running_transaction
);
525 WARN_ON(atomic_read(&cur_trans
->num_writers
) < 1);
526 atomic_dec(&cur_trans
->num_writers
);
529 if (waitqueue_active(&cur_trans
->writer_wait
))
530 wake_up(&cur_trans
->writer_wait
);
531 put_transaction(cur_trans
);
533 if (current
->journal_info
== trans
)
534 current
->journal_info
= NULL
;
535 memset(trans
, 0, sizeof(*trans
));
536 kmem_cache_free(btrfs_trans_handle_cachep
, trans
);
539 btrfs_run_delayed_iputs(root
);
541 if (trans
->aborted
||
542 root
->fs_info
->fs_state
& BTRFS_SUPER_FLAG_ERROR
) {
549 int btrfs_end_transaction(struct btrfs_trans_handle
*trans
,
550 struct btrfs_root
*root
)
554 ret
= __btrfs_end_transaction(trans
, root
, 0, 1);
560 int btrfs_end_transaction_throttle(struct btrfs_trans_handle
*trans
,
561 struct btrfs_root
*root
)
565 ret
= __btrfs_end_transaction(trans
, root
, 1, 1);
571 int btrfs_end_transaction_nolock(struct btrfs_trans_handle
*trans
,
572 struct btrfs_root
*root
)
576 ret
= __btrfs_end_transaction(trans
, root
, 0, 0);
582 int btrfs_end_transaction_dmeta(struct btrfs_trans_handle
*trans
,
583 struct btrfs_root
*root
)
585 return __btrfs_end_transaction(trans
, root
, 1, 1);
589 * when btree blocks are allocated, they have some corresponding bits set for
590 * them in one of two extent_io trees. This is used to make sure all of
591 * those extents are sent to disk but does not wait on them
593 int btrfs_write_marked_extents(struct btrfs_root
*root
,
594 struct extent_io_tree
*dirty_pages
, int mark
)
598 struct address_space
*mapping
= root
->fs_info
->btree_inode
->i_mapping
;
602 while (!find_first_extent_bit(dirty_pages
, start
, &start
, &end
,
604 convert_extent_bit(dirty_pages
, start
, end
, EXTENT_NEED_WAIT
, mark
,
606 err
= filemap_fdatawrite_range(mapping
, start
, end
);
618 * when btree blocks are allocated, they have some corresponding bits set for
619 * them in one of two extent_io trees. This is used to make sure all of
620 * those extents are on disk for transaction or log commit. We wait
621 * on all the pages and clear them from the dirty pages state tree
623 int btrfs_wait_marked_extents(struct btrfs_root
*root
,
624 struct extent_io_tree
*dirty_pages
, int mark
)
628 struct address_space
*mapping
= root
->fs_info
->btree_inode
->i_mapping
;
632 while (!find_first_extent_bit(dirty_pages
, start
, &start
, &end
,
634 clear_extent_bits(dirty_pages
, start
, end
, EXTENT_NEED_WAIT
, GFP_NOFS
);
635 err
= filemap_fdatawait_range(mapping
, start
, end
);
647 * when btree blocks are allocated, they have some corresponding bits set for
648 * them in one of two extent_io trees. This is used to make sure all of
649 * those extents are on disk for transaction or log commit
651 int btrfs_write_and_wait_marked_extents(struct btrfs_root
*root
,
652 struct extent_io_tree
*dirty_pages
, int mark
)
657 ret
= btrfs_write_marked_extents(root
, dirty_pages
, mark
);
658 ret2
= btrfs_wait_marked_extents(root
, dirty_pages
, mark
);
667 int btrfs_write_and_wait_transaction(struct btrfs_trans_handle
*trans
,
668 struct btrfs_root
*root
)
670 if (!trans
|| !trans
->transaction
) {
671 struct inode
*btree_inode
;
672 btree_inode
= root
->fs_info
->btree_inode
;
673 return filemap_write_and_wait(btree_inode
->i_mapping
);
675 return btrfs_write_and_wait_marked_extents(root
,
676 &trans
->transaction
->dirty_pages
,
681 * this is used to update the root pointer in the tree of tree roots.
683 * But, in the case of the extent allocation tree, updating the root
684 * pointer may allocate blocks which may change the root of the extent
687 * So, this loops and repeats and makes sure the cowonly root didn't
688 * change while the root pointer was being updated in the metadata.
690 static int update_cowonly_root(struct btrfs_trans_handle
*trans
,
691 struct btrfs_root
*root
)
696 struct btrfs_root
*tree_root
= root
->fs_info
->tree_root
;
698 old_root_used
= btrfs_root_used(&root
->root_item
);
699 btrfs_write_dirty_block_groups(trans
, root
);
702 old_root_bytenr
= btrfs_root_bytenr(&root
->root_item
);
703 if (old_root_bytenr
== root
->node
->start
&&
704 old_root_used
== btrfs_root_used(&root
->root_item
))
707 btrfs_set_root_node(&root
->root_item
, root
->node
);
708 ret
= btrfs_update_root(trans
, tree_root
,
714 old_root_used
= btrfs_root_used(&root
->root_item
);
715 ret
= btrfs_write_dirty_block_groups(trans
, root
);
720 if (root
!= root
->fs_info
->extent_root
)
721 switch_commit_root(root
);
727 * update all the cowonly tree roots on disk
729 * The error handling in this function may not be obvious. Any of the
730 * failures will cause the file system to go offline. We still need
731 * to clean up the delayed refs.
733 static noinline
int commit_cowonly_roots(struct btrfs_trans_handle
*trans
,
734 struct btrfs_root
*root
)
736 struct btrfs_fs_info
*fs_info
= root
->fs_info
;
737 struct list_head
*next
;
738 struct extent_buffer
*eb
;
741 ret
= btrfs_run_delayed_refs(trans
, root
, (unsigned long)-1);
745 eb
= btrfs_lock_root_node(fs_info
->tree_root
);
746 ret
= btrfs_cow_block(trans
, fs_info
->tree_root
, eb
, NULL
,
748 btrfs_tree_unlock(eb
);
749 free_extent_buffer(eb
);
754 ret
= btrfs_run_delayed_refs(trans
, root
, (unsigned long)-1);
758 while (!list_empty(&fs_info
->dirty_cowonly_roots
)) {
759 next
= fs_info
->dirty_cowonly_roots
.next
;
761 root
= list_entry(next
, struct btrfs_root
, dirty_list
);
763 ret
= update_cowonly_root(trans
, root
);
768 down_write(&fs_info
->extent_commit_sem
);
769 switch_commit_root(fs_info
->extent_root
);
770 up_write(&fs_info
->extent_commit_sem
);
776 * dead roots are old snapshots that need to be deleted. This allocates
777 * a dirty root struct and adds it into the list of dead roots that need to
780 int btrfs_add_dead_root(struct btrfs_root
*root
)
782 spin_lock(&root
->fs_info
->trans_lock
);
783 list_add(&root
->root_list
, &root
->fs_info
->dead_roots
);
784 spin_unlock(&root
->fs_info
->trans_lock
);
789 * update all the cowonly tree roots on disk
791 static noinline
int commit_fs_roots(struct btrfs_trans_handle
*trans
,
792 struct btrfs_root
*root
)
794 struct btrfs_root
*gang
[8];
795 struct btrfs_fs_info
*fs_info
= root
->fs_info
;
800 spin_lock(&fs_info
->fs_roots_radix_lock
);
802 ret
= radix_tree_gang_lookup_tag(&fs_info
->fs_roots_radix
,
805 BTRFS_ROOT_TRANS_TAG
);
808 for (i
= 0; i
< ret
; i
++) {
810 radix_tree_tag_clear(&fs_info
->fs_roots_radix
,
811 (unsigned long)root
->root_key
.objectid
,
812 BTRFS_ROOT_TRANS_TAG
);
813 spin_unlock(&fs_info
->fs_roots_radix_lock
);
815 btrfs_free_log(trans
, root
);
816 btrfs_update_reloc_root(trans
, root
);
817 btrfs_orphan_commit_root(trans
, root
);
819 btrfs_save_ino_cache(root
, trans
);
821 /* see comments in should_cow_block() */
825 if (root
->commit_root
!= root
->node
) {
826 mutex_lock(&root
->fs_commit_mutex
);
827 switch_commit_root(root
);
828 btrfs_unpin_free_ino(root
);
829 mutex_unlock(&root
->fs_commit_mutex
);
831 btrfs_set_root_node(&root
->root_item
,
835 err
= btrfs_update_root(trans
, fs_info
->tree_root
,
838 spin_lock(&fs_info
->fs_roots_radix_lock
);
843 spin_unlock(&fs_info
->fs_roots_radix_lock
);
848 * defrag a given btree. If cacheonly == 1, this won't read from the disk,
849 * otherwise every leaf in the btree is read and defragged.
851 int btrfs_defrag_root(struct btrfs_root
*root
, int cacheonly
)
853 struct btrfs_fs_info
*info
= root
->fs_info
;
854 struct btrfs_trans_handle
*trans
;
858 if (xchg(&root
->defrag_running
, 1))
862 trans
= btrfs_start_transaction(root
, 0);
864 return PTR_ERR(trans
);
866 ret
= btrfs_defrag_leaves(trans
, root
, cacheonly
);
868 nr
= trans
->blocks_used
;
869 btrfs_end_transaction(trans
, root
);
870 btrfs_btree_balance_dirty(info
->tree_root
, nr
);
873 if (btrfs_fs_closing(root
->fs_info
) || ret
!= -EAGAIN
)
876 root
->defrag_running
= 0;
881 * new snapshots need to be created at a very specific time in the
882 * transaction commit. This does the actual creation
884 static noinline
int create_pending_snapshot(struct btrfs_trans_handle
*trans
,
885 struct btrfs_fs_info
*fs_info
,
886 struct btrfs_pending_snapshot
*pending
)
888 struct btrfs_key key
;
889 struct btrfs_root_item
*new_root_item
;
890 struct btrfs_root
*tree_root
= fs_info
->tree_root
;
891 struct btrfs_root
*root
= pending
->root
;
892 struct btrfs_root
*parent_root
;
893 struct btrfs_block_rsv
*rsv
;
894 struct inode
*parent_inode
;
895 struct dentry
*parent
;
896 struct dentry
*dentry
;
897 struct extent_buffer
*tmp
;
898 struct extent_buffer
*old
;
905 rsv
= trans
->block_rsv
;
907 new_root_item
= kmalloc(sizeof(*new_root_item
), GFP_NOFS
);
908 if (!new_root_item
) {
909 ret
= pending
->error
= -ENOMEM
;
913 ret
= btrfs_find_free_objectid(tree_root
, &objectid
);
915 pending
->error
= ret
;
919 btrfs_reloc_pre_snapshot(trans
, pending
, &to_reserve
);
921 if (to_reserve
> 0) {
922 ret
= btrfs_block_rsv_add_noflush(root
, &pending
->block_rsv
,
925 pending
->error
= ret
;
930 key
.objectid
= objectid
;
931 key
.offset
= (u64
)-1;
932 key
.type
= BTRFS_ROOT_ITEM_KEY
;
934 trans
->block_rsv
= &pending
->block_rsv
;
936 dentry
= pending
->dentry
;
937 parent
= dget_parent(dentry
);
938 parent_inode
= parent
->d_inode
;
939 parent_root
= BTRFS_I(parent_inode
)->root
;
940 record_root_in_trans(trans
, parent_root
);
943 * insert the directory item
945 ret
= btrfs_set_inode_index(parent_inode
, &index
);
946 BUG_ON(ret
); /* -ENOMEM */
947 ret
= btrfs_insert_dir_item(trans
, parent_root
,
948 dentry
->d_name
.name
, dentry
->d_name
.len
,
950 BTRFS_FT_DIR
, index
);
951 if (ret
== -EEXIST
) {
952 pending
->error
= -EEXIST
;
956 goto abort_trans_dput
;
959 btrfs_i_size_write(parent_inode
, parent_inode
->i_size
+
960 dentry
->d_name
.len
* 2);
961 ret
= btrfs_update_inode(trans
, parent_root
, parent_inode
);
963 goto abort_trans_dput
;
966 * pull in the delayed directory update
967 * and the delayed inode item
968 * otherwise we corrupt the FS during
971 ret
= btrfs_run_delayed_items(trans
, root
);
972 if (ret
) { /* Transaction aborted */
977 record_root_in_trans(trans
, root
);
978 btrfs_set_root_last_snapshot(&root
->root_item
, trans
->transid
);
979 memcpy(new_root_item
, &root
->root_item
, sizeof(*new_root_item
));
980 btrfs_check_and_init_root_item(new_root_item
);
982 root_flags
= btrfs_root_flags(new_root_item
);
983 if (pending
->readonly
)
984 root_flags
|= BTRFS_ROOT_SUBVOL_RDONLY
;
986 root_flags
&= ~BTRFS_ROOT_SUBVOL_RDONLY
;
987 btrfs_set_root_flags(new_root_item
, root_flags
);
989 old
= btrfs_lock_root_node(root
);
990 ret
= btrfs_cow_block(trans
, root
, old
, NULL
, 0, &old
);
992 btrfs_tree_unlock(old
);
993 free_extent_buffer(old
);
994 goto abort_trans_dput
;
997 btrfs_set_lock_blocking(old
);
999 ret
= btrfs_copy_root(trans
, root
, old
, &tmp
, objectid
);
1000 /* clean up in any case */
1001 btrfs_tree_unlock(old
);
1002 free_extent_buffer(old
);
1004 goto abort_trans_dput
;
1006 /* see comments in should_cow_block() */
1007 root
->force_cow
= 1;
1010 btrfs_set_root_node(new_root_item
, tmp
);
1011 /* record when the snapshot was created in key.offset */
1012 key
.offset
= trans
->transid
;
1013 ret
= btrfs_insert_root(trans
, tree_root
, &key
, new_root_item
);
1014 btrfs_tree_unlock(tmp
);
1015 free_extent_buffer(tmp
);
1017 goto abort_trans_dput
;
1020 * insert root back/forward references
1022 ret
= btrfs_add_root_ref(trans
, tree_root
, objectid
,
1023 parent_root
->root_key
.objectid
,
1024 btrfs_ino(parent_inode
), index
,
1025 dentry
->d_name
.name
, dentry
->d_name
.len
);
1030 key
.offset
= (u64
)-1;
1031 pending
->snap
= btrfs_read_fs_root_no_name(root
->fs_info
, &key
);
1032 if (IS_ERR(pending
->snap
)) {
1033 ret
= PTR_ERR(pending
->snap
);
1037 ret
= btrfs_reloc_post_snapshot(trans
, pending
);
1042 kfree(new_root_item
);
1043 trans
->block_rsv
= rsv
;
1044 btrfs_block_rsv_release(root
, &pending
->block_rsv
, (u64
)-1);
1050 btrfs_abort_transaction(trans
, root
, ret
);
1055 * create all the snapshots we've scheduled for creation
1057 static noinline
int create_pending_snapshots(struct btrfs_trans_handle
*trans
,
1058 struct btrfs_fs_info
*fs_info
)
1060 struct btrfs_pending_snapshot
*pending
;
1061 struct list_head
*head
= &trans
->transaction
->pending_snapshots
;
1063 list_for_each_entry(pending
, head
, list
)
1064 create_pending_snapshot(trans
, fs_info
, pending
);
1068 static void update_super_roots(struct btrfs_root
*root
)
1070 struct btrfs_root_item
*root_item
;
1071 struct btrfs_super_block
*super
;
1073 super
= root
->fs_info
->super_copy
;
1075 root_item
= &root
->fs_info
->chunk_root
->root_item
;
1076 super
->chunk_root
= root_item
->bytenr
;
1077 super
->chunk_root_generation
= root_item
->generation
;
1078 super
->chunk_root_level
= root_item
->level
;
1080 root_item
= &root
->fs_info
->tree_root
->root_item
;
1081 super
->root
= root_item
->bytenr
;
1082 super
->generation
= root_item
->generation
;
1083 super
->root_level
= root_item
->level
;
1084 if (btrfs_test_opt(root
, SPACE_CACHE
))
1085 super
->cache_generation
= root_item
->generation
;
1088 int btrfs_transaction_in_commit(struct btrfs_fs_info
*info
)
1091 spin_lock(&info
->trans_lock
);
1092 if (info
->running_transaction
)
1093 ret
= info
->running_transaction
->in_commit
;
1094 spin_unlock(&info
->trans_lock
);
1098 int btrfs_transaction_blocked(struct btrfs_fs_info
*info
)
1101 spin_lock(&info
->trans_lock
);
1102 if (info
->running_transaction
)
1103 ret
= info
->running_transaction
->blocked
;
1104 spin_unlock(&info
->trans_lock
);
1109 * wait for the current transaction commit to start and block subsequent
1112 static void wait_current_trans_commit_start(struct btrfs_root
*root
,
1113 struct btrfs_transaction
*trans
)
1115 wait_event(root
->fs_info
->transaction_blocked_wait
, trans
->in_commit
);
1119 * wait for the current transaction to start and then become unblocked.
1122 static void wait_current_trans_commit_start_and_unblock(struct btrfs_root
*root
,
1123 struct btrfs_transaction
*trans
)
1125 wait_event(root
->fs_info
->transaction_wait
,
1126 trans
->commit_done
|| (trans
->in_commit
&& !trans
->blocked
));
1130 * commit transactions asynchronously. once btrfs_commit_transaction_async
1131 * returns, any subsequent transaction will not be allowed to join.
1133 struct btrfs_async_commit
{
1134 struct btrfs_trans_handle
*newtrans
;
1135 struct btrfs_root
*root
;
1136 struct delayed_work work
;
1139 static void do_async_commit(struct work_struct
*work
)
1141 struct btrfs_async_commit
*ac
=
1142 container_of(work
, struct btrfs_async_commit
, work
.work
);
1144 btrfs_commit_transaction(ac
->newtrans
, ac
->root
);
1148 int btrfs_commit_transaction_async(struct btrfs_trans_handle
*trans
,
1149 struct btrfs_root
*root
,
1150 int wait_for_unblock
)
1152 struct btrfs_async_commit
*ac
;
1153 struct btrfs_transaction
*cur_trans
;
1155 ac
= kmalloc(sizeof(*ac
), GFP_NOFS
);
1159 INIT_DELAYED_WORK(&ac
->work
, do_async_commit
);
1161 ac
->newtrans
= btrfs_join_transaction(root
);
1162 if (IS_ERR(ac
->newtrans
)) {
1163 int err
= PTR_ERR(ac
->newtrans
);
1168 /* take transaction reference */
1169 cur_trans
= trans
->transaction
;
1170 atomic_inc(&cur_trans
->use_count
);
1172 btrfs_end_transaction(trans
, root
);
1173 schedule_delayed_work(&ac
->work
, 0);
1175 /* wait for transaction to start and unblock */
1176 if (wait_for_unblock
)
1177 wait_current_trans_commit_start_and_unblock(root
, cur_trans
);
1179 wait_current_trans_commit_start(root
, cur_trans
);
1181 if (current
->journal_info
== trans
)
1182 current
->journal_info
= NULL
;
1184 put_transaction(cur_trans
);
1189 static void cleanup_transaction(struct btrfs_trans_handle
*trans
,
1190 struct btrfs_root
*root
)
1192 struct btrfs_transaction
*cur_trans
= trans
->transaction
;
1194 WARN_ON(trans
->use_count
> 1);
1196 spin_lock(&root
->fs_info
->trans_lock
);
1197 list_del_init(&cur_trans
->list
);
1198 spin_unlock(&root
->fs_info
->trans_lock
);
1200 btrfs_cleanup_one_transaction(trans
->transaction
, root
);
1202 put_transaction(cur_trans
);
1203 put_transaction(cur_trans
);
1205 trace_btrfs_transaction_commit(root
);
1207 btrfs_scrub_continue(root
);
1209 if (current
->journal_info
== trans
)
1210 current
->journal_info
= NULL
;
1212 kmem_cache_free(btrfs_trans_handle_cachep
, trans
);
1216 * btrfs_transaction state sequence:
1217 * in_commit = 0, blocked = 0 (initial)
1218 * in_commit = 1, blocked = 1
1222 int btrfs_commit_transaction(struct btrfs_trans_handle
*trans
,
1223 struct btrfs_root
*root
)
1225 unsigned long joined
= 0;
1226 struct btrfs_transaction
*cur_trans
= trans
->transaction
;
1227 struct btrfs_transaction
*prev_trans
= NULL
;
1230 int should_grow
= 0;
1231 unsigned long now
= get_seconds();
1232 int flush_on_commit
= btrfs_test_opt(root
, FLUSHONCOMMIT
);
1234 btrfs_run_ordered_operations(root
, 0);
1236 btrfs_trans_release_metadata(trans
, root
);
1237 trans
->block_rsv
= NULL
;
1239 if (cur_trans
->aborted
)
1240 goto cleanup_transaction
;
1242 /* make a pass through all the delayed refs we have so far
1243 * any runnings procs may add more while we are here
1245 ret
= btrfs_run_delayed_refs(trans
, root
, 0);
1247 goto cleanup_transaction
;
1249 cur_trans
= trans
->transaction
;
1252 * set the flushing flag so procs in this transaction have to
1253 * start sending their work down.
1255 cur_trans
->delayed_refs
.flushing
= 1;
1257 ret
= btrfs_run_delayed_refs(trans
, root
, 0);
1259 goto cleanup_transaction
;
1261 spin_lock(&cur_trans
->commit_lock
);
1262 if (cur_trans
->in_commit
) {
1263 spin_unlock(&cur_trans
->commit_lock
);
1264 atomic_inc(&cur_trans
->use_count
);
1265 ret
= btrfs_end_transaction(trans
, root
);
1267 wait_for_commit(root
, cur_trans
);
1269 put_transaction(cur_trans
);
1274 trans
->transaction
->in_commit
= 1;
1275 trans
->transaction
->blocked
= 1;
1276 spin_unlock(&cur_trans
->commit_lock
);
1277 wake_up(&root
->fs_info
->transaction_blocked_wait
);
1279 spin_lock(&root
->fs_info
->trans_lock
);
1280 if (cur_trans
->list
.prev
!= &root
->fs_info
->trans_list
) {
1281 prev_trans
= list_entry(cur_trans
->list
.prev
,
1282 struct btrfs_transaction
, list
);
1283 if (!prev_trans
->commit_done
) {
1284 atomic_inc(&prev_trans
->use_count
);
1285 spin_unlock(&root
->fs_info
->trans_lock
);
1287 wait_for_commit(root
, prev_trans
);
1289 put_transaction(prev_trans
);
1291 spin_unlock(&root
->fs_info
->trans_lock
);
1294 spin_unlock(&root
->fs_info
->trans_lock
);
1297 if (now
< cur_trans
->start_time
|| now
- cur_trans
->start_time
< 1)
1301 int snap_pending
= 0;
1303 joined
= cur_trans
->num_joined
;
1304 if (!list_empty(&trans
->transaction
->pending_snapshots
))
1307 WARN_ON(cur_trans
!= trans
->transaction
);
1309 if (flush_on_commit
|| snap_pending
) {
1310 btrfs_start_delalloc_inodes(root
, 1);
1311 btrfs_wait_ordered_extents(root
, 0, 1);
1314 ret
= btrfs_run_delayed_items(trans
, root
);
1316 goto cleanup_transaction
;
1319 * rename don't use btrfs_join_transaction, so, once we
1320 * set the transaction to blocked above, we aren't going
1321 * to get any new ordered operations. We can safely run
1322 * it here and no for sure that nothing new will be added
1325 btrfs_run_ordered_operations(root
, 1);
1327 prepare_to_wait(&cur_trans
->writer_wait
, &wait
,
1328 TASK_UNINTERRUPTIBLE
);
1330 if (atomic_read(&cur_trans
->num_writers
) > 1)
1331 schedule_timeout(MAX_SCHEDULE_TIMEOUT
);
1332 else if (should_grow
)
1333 schedule_timeout(1);
1335 finish_wait(&cur_trans
->writer_wait
, &wait
);
1336 } while (atomic_read(&cur_trans
->num_writers
) > 1 ||
1337 (should_grow
&& cur_trans
->num_joined
!= joined
));
1340 * Ok now we need to make sure to block out any other joins while we
1341 * commit the transaction. We could have started a join before setting
1342 * no_join so make sure to wait for num_writers to == 1 again.
1344 spin_lock(&root
->fs_info
->trans_lock
);
1345 root
->fs_info
->trans_no_join
= 1;
1346 spin_unlock(&root
->fs_info
->trans_lock
);
1347 wait_event(cur_trans
->writer_wait
,
1348 atomic_read(&cur_trans
->num_writers
) == 1);
1351 * the reloc mutex makes sure that we stop
1352 * the balancing code from coming in and moving
1353 * extents around in the middle of the commit
1355 mutex_lock(&root
->fs_info
->reloc_mutex
);
1357 ret
= btrfs_run_delayed_items(trans
, root
);
1359 mutex_unlock(&root
->fs_info
->reloc_mutex
);
1360 goto cleanup_transaction
;
1363 ret
= create_pending_snapshots(trans
, root
->fs_info
);
1365 mutex_unlock(&root
->fs_info
->reloc_mutex
);
1366 goto cleanup_transaction
;
1369 ret
= btrfs_run_delayed_refs(trans
, root
, (unsigned long)-1);
1371 mutex_unlock(&root
->fs_info
->reloc_mutex
);
1372 goto cleanup_transaction
;
1376 * make sure none of the code above managed to slip in a
1379 btrfs_assert_delayed_root_empty(root
);
1381 WARN_ON(cur_trans
!= trans
->transaction
);
1383 btrfs_scrub_pause(root
);
1384 /* btrfs_commit_tree_roots is responsible for getting the
1385 * various roots consistent with each other. Every pointer
1386 * in the tree of tree roots has to point to the most up to date
1387 * root for every subvolume and other tree. So, we have to keep
1388 * the tree logging code from jumping in and changing any
1391 * At this point in the commit, there can't be any tree-log
1392 * writers, but a little lower down we drop the trans mutex
1393 * and let new people in. By holding the tree_log_mutex
1394 * from now until after the super is written, we avoid races
1395 * with the tree-log code.
1397 mutex_lock(&root
->fs_info
->tree_log_mutex
);
1399 ret
= commit_fs_roots(trans
, root
);
1401 mutex_unlock(&root
->fs_info
->tree_log_mutex
);
1402 goto cleanup_transaction
;
1405 /* commit_fs_roots gets rid of all the tree log roots, it is now
1406 * safe to free the root of tree log roots
1408 btrfs_free_log_root_tree(trans
, root
->fs_info
);
1410 ret
= commit_cowonly_roots(trans
, root
);
1412 mutex_unlock(&root
->fs_info
->tree_log_mutex
);
1413 goto cleanup_transaction
;
1416 btrfs_prepare_extent_commit(trans
, root
);
1418 cur_trans
= root
->fs_info
->running_transaction
;
1420 btrfs_set_root_node(&root
->fs_info
->tree_root
->root_item
,
1421 root
->fs_info
->tree_root
->node
);
1422 switch_commit_root(root
->fs_info
->tree_root
);
1424 btrfs_set_root_node(&root
->fs_info
->chunk_root
->root_item
,
1425 root
->fs_info
->chunk_root
->node
);
1426 switch_commit_root(root
->fs_info
->chunk_root
);
1428 update_super_roots(root
);
1430 if (!root
->fs_info
->log_root_recovering
) {
1431 btrfs_set_super_log_root(root
->fs_info
->super_copy
, 0);
1432 btrfs_set_super_log_root_level(root
->fs_info
->super_copy
, 0);
1435 memcpy(root
->fs_info
->super_for_commit
, root
->fs_info
->super_copy
,
1436 sizeof(*root
->fs_info
->super_copy
));
1438 trans
->transaction
->blocked
= 0;
1439 spin_lock(&root
->fs_info
->trans_lock
);
1440 root
->fs_info
->running_transaction
= NULL
;
1441 root
->fs_info
->trans_no_join
= 0;
1442 spin_unlock(&root
->fs_info
->trans_lock
);
1443 mutex_unlock(&root
->fs_info
->reloc_mutex
);
1445 wake_up(&root
->fs_info
->transaction_wait
);
1447 ret
= btrfs_write_and_wait_transaction(trans
, root
);
1449 btrfs_error(root
->fs_info
, ret
,
1450 "Error while writing out transaction.");
1451 mutex_unlock(&root
->fs_info
->tree_log_mutex
);
1452 goto cleanup_transaction
;
1455 ret
= write_ctree_super(trans
, root
, 0);
1457 mutex_unlock(&root
->fs_info
->tree_log_mutex
);
1458 goto cleanup_transaction
;
1462 * the super is written, we can safely allow the tree-loggers
1463 * to go about their business
1465 mutex_unlock(&root
->fs_info
->tree_log_mutex
);
1467 btrfs_finish_extent_commit(trans
, root
);
1469 cur_trans
->commit_done
= 1;
1471 root
->fs_info
->last_trans_committed
= cur_trans
->transid
;
1473 wake_up(&cur_trans
->commit_wait
);
1475 spin_lock(&root
->fs_info
->trans_lock
);
1476 list_del_init(&cur_trans
->list
);
1477 spin_unlock(&root
->fs_info
->trans_lock
);
1479 put_transaction(cur_trans
);
1480 put_transaction(cur_trans
);
1482 trace_btrfs_transaction_commit(root
);
1484 btrfs_scrub_continue(root
);
1486 if (current
->journal_info
== trans
)
1487 current
->journal_info
= NULL
;
1489 kmem_cache_free(btrfs_trans_handle_cachep
, trans
);
1491 if (current
!= root
->fs_info
->transaction_kthread
)
1492 btrfs_run_delayed_iputs(root
);
1496 cleanup_transaction
:
1497 btrfs_printk(root
->fs_info
, "Skipping commit of aborted transaction.\n");
1499 if (current
->journal_info
== trans
)
1500 current
->journal_info
= NULL
;
1501 cleanup_transaction(trans
, root
);
1507 * interface function to delete all the snapshots we have scheduled for deletion
1509 int btrfs_clean_old_snapshots(struct btrfs_root
*root
)
1512 struct btrfs_fs_info
*fs_info
= root
->fs_info
;
1514 spin_lock(&fs_info
->trans_lock
);
1515 list_splice_init(&fs_info
->dead_roots
, &list
);
1516 spin_unlock(&fs_info
->trans_lock
);
1518 while (!list_empty(&list
)) {
1521 root
= list_entry(list
.next
, struct btrfs_root
, root_list
);
1522 list_del(&root
->root_list
);
1524 btrfs_kill_all_delayed_nodes(root
);
1526 if (btrfs_header_backref_rev(root
->node
) <
1527 BTRFS_MIXED_BACKREF_REV
)
1528 ret
= btrfs_drop_snapshot(root
, NULL
, 0, 0);
1530 ret
=btrfs_drop_snapshot(root
, NULL
, 1, 0);