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
;
485 if (--trans
->use_count
) {
486 trans
->block_rsv
= trans
->orig_rsv
;
490 btrfs_trans_release_metadata(trans
, root
);
491 trans
->block_rsv
= NULL
;
493 unsigned long cur
= trans
->delayed_ref_updates
;
494 trans
->delayed_ref_updates
= 0;
496 trans
->transaction
->delayed_refs
.num_heads_ready
> 64) {
497 trans
->delayed_ref_updates
= 0;
498 btrfs_run_delayed_refs(trans
, root
, cur
);
505 if (lock
&& !atomic_read(&root
->fs_info
->open_ioctl_trans
) &&
506 should_end_transaction(trans
, root
)) {
507 trans
->transaction
->blocked
= 1;
511 if (lock
&& cur_trans
->blocked
&& !cur_trans
->in_commit
) {
514 * We may race with somebody else here so end up having
515 * to call end_transaction on ourselves again, so inc
519 return btrfs_commit_transaction(trans
, root
);
521 wake_up_process(info
->transaction_kthread
);
525 WARN_ON(cur_trans
!= info
->running_transaction
);
526 WARN_ON(atomic_read(&cur_trans
->num_writers
) < 1);
527 atomic_dec(&cur_trans
->num_writers
);
530 if (waitqueue_active(&cur_trans
->writer_wait
))
531 wake_up(&cur_trans
->writer_wait
);
532 put_transaction(cur_trans
);
534 if (current
->journal_info
== trans
)
535 current
->journal_info
= NULL
;
538 btrfs_run_delayed_iputs(root
);
540 if (trans
->aborted
||
541 root
->fs_info
->fs_state
& BTRFS_SUPER_FLAG_ERROR
) {
545 memset(trans
, 0, sizeof(*trans
));
546 kmem_cache_free(btrfs_trans_handle_cachep
, trans
);
550 int btrfs_end_transaction(struct btrfs_trans_handle
*trans
,
551 struct btrfs_root
*root
)
555 ret
= __btrfs_end_transaction(trans
, root
, 0, 1);
561 int btrfs_end_transaction_throttle(struct btrfs_trans_handle
*trans
,
562 struct btrfs_root
*root
)
566 ret
= __btrfs_end_transaction(trans
, root
, 1, 1);
572 int btrfs_end_transaction_nolock(struct btrfs_trans_handle
*trans
,
573 struct btrfs_root
*root
)
577 ret
= __btrfs_end_transaction(trans
, root
, 0, 0);
583 int btrfs_end_transaction_dmeta(struct btrfs_trans_handle
*trans
,
584 struct btrfs_root
*root
)
586 return __btrfs_end_transaction(trans
, root
, 1, 1);
590 * when btree blocks are allocated, they have some corresponding bits set for
591 * them in one of two extent_io trees. This is used to make sure all of
592 * those extents are sent to disk but does not wait on them
594 int btrfs_write_marked_extents(struct btrfs_root
*root
,
595 struct extent_io_tree
*dirty_pages
, int mark
)
599 struct address_space
*mapping
= root
->fs_info
->btree_inode
->i_mapping
;
603 while (!find_first_extent_bit(dirty_pages
, start
, &start
, &end
,
605 convert_extent_bit(dirty_pages
, start
, end
, EXTENT_NEED_WAIT
, mark
,
607 err
= filemap_fdatawrite_range(mapping
, start
, end
);
619 * when btree blocks are allocated, they have some corresponding bits set for
620 * them in one of two extent_io trees. This is used to make sure all of
621 * those extents are on disk for transaction or log commit. We wait
622 * on all the pages and clear them from the dirty pages state tree
624 int btrfs_wait_marked_extents(struct btrfs_root
*root
,
625 struct extent_io_tree
*dirty_pages
, int mark
)
629 struct address_space
*mapping
= root
->fs_info
->btree_inode
->i_mapping
;
633 while (!find_first_extent_bit(dirty_pages
, start
, &start
, &end
,
635 clear_extent_bits(dirty_pages
, start
, end
, EXTENT_NEED_WAIT
, GFP_NOFS
);
636 err
= filemap_fdatawait_range(mapping
, start
, end
);
648 * when btree blocks are allocated, they have some corresponding bits set for
649 * them in one of two extent_io trees. This is used to make sure all of
650 * those extents are on disk for transaction or log commit
652 int btrfs_write_and_wait_marked_extents(struct btrfs_root
*root
,
653 struct extent_io_tree
*dirty_pages
, int mark
)
658 ret
= btrfs_write_marked_extents(root
, dirty_pages
, mark
);
659 ret2
= btrfs_wait_marked_extents(root
, dirty_pages
, mark
);
668 int btrfs_write_and_wait_transaction(struct btrfs_trans_handle
*trans
,
669 struct btrfs_root
*root
)
671 if (!trans
|| !trans
->transaction
) {
672 struct inode
*btree_inode
;
673 btree_inode
= root
->fs_info
->btree_inode
;
674 return filemap_write_and_wait(btree_inode
->i_mapping
);
676 return btrfs_write_and_wait_marked_extents(root
,
677 &trans
->transaction
->dirty_pages
,
682 * this is used to update the root pointer in the tree of tree roots.
684 * But, in the case of the extent allocation tree, updating the root
685 * pointer may allocate blocks which may change the root of the extent
688 * So, this loops and repeats and makes sure the cowonly root didn't
689 * change while the root pointer was being updated in the metadata.
691 static int update_cowonly_root(struct btrfs_trans_handle
*trans
,
692 struct btrfs_root
*root
)
697 struct btrfs_root
*tree_root
= root
->fs_info
->tree_root
;
699 old_root_used
= btrfs_root_used(&root
->root_item
);
700 btrfs_write_dirty_block_groups(trans
, root
);
703 old_root_bytenr
= btrfs_root_bytenr(&root
->root_item
);
704 if (old_root_bytenr
== root
->node
->start
&&
705 old_root_used
== btrfs_root_used(&root
->root_item
))
708 btrfs_set_root_node(&root
->root_item
, root
->node
);
709 ret
= btrfs_update_root(trans
, tree_root
,
715 old_root_used
= btrfs_root_used(&root
->root_item
);
716 ret
= btrfs_write_dirty_block_groups(trans
, root
);
721 if (root
!= root
->fs_info
->extent_root
)
722 switch_commit_root(root
);
728 * update all the cowonly tree roots on disk
730 * The error handling in this function may not be obvious. Any of the
731 * failures will cause the file system to go offline. We still need
732 * to clean up the delayed refs.
734 static noinline
int commit_cowonly_roots(struct btrfs_trans_handle
*trans
,
735 struct btrfs_root
*root
)
737 struct btrfs_fs_info
*fs_info
= root
->fs_info
;
738 struct list_head
*next
;
739 struct extent_buffer
*eb
;
742 ret
= btrfs_run_delayed_refs(trans
, root
, (unsigned long)-1);
746 eb
= btrfs_lock_root_node(fs_info
->tree_root
);
747 ret
= btrfs_cow_block(trans
, fs_info
->tree_root
, eb
, NULL
,
749 btrfs_tree_unlock(eb
);
750 free_extent_buffer(eb
);
755 ret
= btrfs_run_delayed_refs(trans
, root
, (unsigned long)-1);
759 while (!list_empty(&fs_info
->dirty_cowonly_roots
)) {
760 next
= fs_info
->dirty_cowonly_roots
.next
;
762 root
= list_entry(next
, struct btrfs_root
, dirty_list
);
764 ret
= update_cowonly_root(trans
, root
);
769 down_write(&fs_info
->extent_commit_sem
);
770 switch_commit_root(fs_info
->extent_root
);
771 up_write(&fs_info
->extent_commit_sem
);
777 * dead roots are old snapshots that need to be deleted. This allocates
778 * a dirty root struct and adds it into the list of dead roots that need to
781 int btrfs_add_dead_root(struct btrfs_root
*root
)
783 spin_lock(&root
->fs_info
->trans_lock
);
784 list_add(&root
->root_list
, &root
->fs_info
->dead_roots
);
785 spin_unlock(&root
->fs_info
->trans_lock
);
790 * update all the cowonly tree roots on disk
792 static noinline
int commit_fs_roots(struct btrfs_trans_handle
*trans
,
793 struct btrfs_root
*root
)
795 struct btrfs_root
*gang
[8];
796 struct btrfs_fs_info
*fs_info
= root
->fs_info
;
801 spin_lock(&fs_info
->fs_roots_radix_lock
);
803 ret
= radix_tree_gang_lookup_tag(&fs_info
->fs_roots_radix
,
806 BTRFS_ROOT_TRANS_TAG
);
809 for (i
= 0; i
< ret
; i
++) {
811 radix_tree_tag_clear(&fs_info
->fs_roots_radix
,
812 (unsigned long)root
->root_key
.objectid
,
813 BTRFS_ROOT_TRANS_TAG
);
814 spin_unlock(&fs_info
->fs_roots_radix_lock
);
816 btrfs_free_log(trans
, root
);
817 btrfs_update_reloc_root(trans
, root
);
818 btrfs_orphan_commit_root(trans
, root
);
820 btrfs_save_ino_cache(root
, trans
);
822 /* see comments in should_cow_block() */
826 if (root
->commit_root
!= root
->node
) {
827 mutex_lock(&root
->fs_commit_mutex
);
828 switch_commit_root(root
);
829 btrfs_unpin_free_ino(root
);
830 mutex_unlock(&root
->fs_commit_mutex
);
832 btrfs_set_root_node(&root
->root_item
,
836 err
= btrfs_update_root(trans
, fs_info
->tree_root
,
839 spin_lock(&fs_info
->fs_roots_radix_lock
);
844 spin_unlock(&fs_info
->fs_roots_radix_lock
);
849 * defrag a given btree. If cacheonly == 1, this won't read from the disk,
850 * otherwise every leaf in the btree is read and defragged.
852 int btrfs_defrag_root(struct btrfs_root
*root
, int cacheonly
)
854 struct btrfs_fs_info
*info
= root
->fs_info
;
855 struct btrfs_trans_handle
*trans
;
859 if (xchg(&root
->defrag_running
, 1))
863 trans
= btrfs_start_transaction(root
, 0);
865 return PTR_ERR(trans
);
867 ret
= btrfs_defrag_leaves(trans
, root
, cacheonly
);
869 nr
= trans
->blocks_used
;
870 btrfs_end_transaction(trans
, root
);
871 btrfs_btree_balance_dirty(info
->tree_root
, nr
);
874 if (btrfs_fs_closing(root
->fs_info
) || ret
!= -EAGAIN
)
877 root
->defrag_running
= 0;
882 * new snapshots need to be created at a very specific time in the
883 * transaction commit. This does the actual creation
885 static noinline
int create_pending_snapshot(struct btrfs_trans_handle
*trans
,
886 struct btrfs_fs_info
*fs_info
,
887 struct btrfs_pending_snapshot
*pending
)
889 struct btrfs_key key
;
890 struct btrfs_root_item
*new_root_item
;
891 struct btrfs_root
*tree_root
= fs_info
->tree_root
;
892 struct btrfs_root
*root
= pending
->root
;
893 struct btrfs_root
*parent_root
;
894 struct btrfs_block_rsv
*rsv
;
895 struct inode
*parent_inode
;
896 struct dentry
*parent
;
897 struct dentry
*dentry
;
898 struct extent_buffer
*tmp
;
899 struct extent_buffer
*old
;
906 rsv
= trans
->block_rsv
;
908 new_root_item
= kmalloc(sizeof(*new_root_item
), GFP_NOFS
);
909 if (!new_root_item
) {
910 ret
= pending
->error
= -ENOMEM
;
914 ret
= btrfs_find_free_objectid(tree_root
, &objectid
);
916 pending
->error
= ret
;
920 btrfs_reloc_pre_snapshot(trans
, pending
, &to_reserve
);
922 if (to_reserve
> 0) {
923 ret
= btrfs_block_rsv_add_noflush(root
, &pending
->block_rsv
,
926 pending
->error
= ret
;
931 key
.objectid
= objectid
;
932 key
.offset
= (u64
)-1;
933 key
.type
= BTRFS_ROOT_ITEM_KEY
;
935 trans
->block_rsv
= &pending
->block_rsv
;
937 dentry
= pending
->dentry
;
938 parent
= dget_parent(dentry
);
939 parent_inode
= parent
->d_inode
;
940 parent_root
= BTRFS_I(parent_inode
)->root
;
941 record_root_in_trans(trans
, parent_root
);
944 * insert the directory item
946 ret
= btrfs_set_inode_index(parent_inode
, &index
);
947 BUG_ON(ret
); /* -ENOMEM */
948 ret
= btrfs_insert_dir_item(trans
, parent_root
,
949 dentry
->d_name
.name
, dentry
->d_name
.len
,
951 BTRFS_FT_DIR
, index
);
952 if (ret
== -EEXIST
) {
953 pending
->error
= -EEXIST
;
957 goto abort_trans_dput
;
960 btrfs_i_size_write(parent_inode
, parent_inode
->i_size
+
961 dentry
->d_name
.len
* 2);
962 ret
= btrfs_update_inode(trans
, parent_root
, parent_inode
);
964 goto abort_trans_dput
;
967 * pull in the delayed directory update
968 * and the delayed inode item
969 * otherwise we corrupt the FS during
972 ret
= btrfs_run_delayed_items(trans
, root
);
973 if (ret
) { /* Transaction aborted */
978 record_root_in_trans(trans
, root
);
979 btrfs_set_root_last_snapshot(&root
->root_item
, trans
->transid
);
980 memcpy(new_root_item
, &root
->root_item
, sizeof(*new_root_item
));
981 btrfs_check_and_init_root_item(new_root_item
);
983 root_flags
= btrfs_root_flags(new_root_item
);
984 if (pending
->readonly
)
985 root_flags
|= BTRFS_ROOT_SUBVOL_RDONLY
;
987 root_flags
&= ~BTRFS_ROOT_SUBVOL_RDONLY
;
988 btrfs_set_root_flags(new_root_item
, root_flags
);
990 old
= btrfs_lock_root_node(root
);
991 ret
= btrfs_cow_block(trans
, root
, old
, NULL
, 0, &old
);
993 btrfs_tree_unlock(old
);
994 free_extent_buffer(old
);
995 goto abort_trans_dput
;
998 btrfs_set_lock_blocking(old
);
1000 ret
= btrfs_copy_root(trans
, root
, old
, &tmp
, objectid
);
1001 /* clean up in any case */
1002 btrfs_tree_unlock(old
);
1003 free_extent_buffer(old
);
1005 goto abort_trans_dput
;
1007 /* see comments in should_cow_block() */
1008 root
->force_cow
= 1;
1011 btrfs_set_root_node(new_root_item
, tmp
);
1012 /* record when the snapshot was created in key.offset */
1013 key
.offset
= trans
->transid
;
1014 ret
= btrfs_insert_root(trans
, tree_root
, &key
, new_root_item
);
1015 btrfs_tree_unlock(tmp
);
1016 free_extent_buffer(tmp
);
1018 goto abort_trans_dput
;
1021 * insert root back/forward references
1023 ret
= btrfs_add_root_ref(trans
, tree_root
, objectid
,
1024 parent_root
->root_key
.objectid
,
1025 btrfs_ino(parent_inode
), index
,
1026 dentry
->d_name
.name
, dentry
->d_name
.len
);
1031 key
.offset
= (u64
)-1;
1032 pending
->snap
= btrfs_read_fs_root_no_name(root
->fs_info
, &key
);
1033 if (IS_ERR(pending
->snap
)) {
1034 ret
= PTR_ERR(pending
->snap
);
1038 ret
= btrfs_reloc_post_snapshot(trans
, pending
);
1043 kfree(new_root_item
);
1044 trans
->block_rsv
= rsv
;
1045 btrfs_block_rsv_release(root
, &pending
->block_rsv
, (u64
)-1);
1051 btrfs_abort_transaction(trans
, root
, ret
);
1056 * create all the snapshots we've scheduled for creation
1058 static noinline
int create_pending_snapshots(struct btrfs_trans_handle
*trans
,
1059 struct btrfs_fs_info
*fs_info
)
1061 struct btrfs_pending_snapshot
*pending
;
1062 struct list_head
*head
= &trans
->transaction
->pending_snapshots
;
1064 list_for_each_entry(pending
, head
, list
)
1065 create_pending_snapshot(trans
, fs_info
, pending
);
1069 static void update_super_roots(struct btrfs_root
*root
)
1071 struct btrfs_root_item
*root_item
;
1072 struct btrfs_super_block
*super
;
1074 super
= root
->fs_info
->super_copy
;
1076 root_item
= &root
->fs_info
->chunk_root
->root_item
;
1077 super
->chunk_root
= root_item
->bytenr
;
1078 super
->chunk_root_generation
= root_item
->generation
;
1079 super
->chunk_root_level
= root_item
->level
;
1081 root_item
= &root
->fs_info
->tree_root
->root_item
;
1082 super
->root
= root_item
->bytenr
;
1083 super
->generation
= root_item
->generation
;
1084 super
->root_level
= root_item
->level
;
1085 if (btrfs_test_opt(root
, SPACE_CACHE
))
1086 super
->cache_generation
= root_item
->generation
;
1089 int btrfs_transaction_in_commit(struct btrfs_fs_info
*info
)
1092 spin_lock(&info
->trans_lock
);
1093 if (info
->running_transaction
)
1094 ret
= info
->running_transaction
->in_commit
;
1095 spin_unlock(&info
->trans_lock
);
1099 int btrfs_transaction_blocked(struct btrfs_fs_info
*info
)
1102 spin_lock(&info
->trans_lock
);
1103 if (info
->running_transaction
)
1104 ret
= info
->running_transaction
->blocked
;
1105 spin_unlock(&info
->trans_lock
);
1110 * wait for the current transaction commit to start and block subsequent
1113 static void wait_current_trans_commit_start(struct btrfs_root
*root
,
1114 struct btrfs_transaction
*trans
)
1116 wait_event(root
->fs_info
->transaction_blocked_wait
, trans
->in_commit
);
1120 * wait for the current transaction to start and then become unblocked.
1123 static void wait_current_trans_commit_start_and_unblock(struct btrfs_root
*root
,
1124 struct btrfs_transaction
*trans
)
1126 wait_event(root
->fs_info
->transaction_wait
,
1127 trans
->commit_done
|| (trans
->in_commit
&& !trans
->blocked
));
1131 * commit transactions asynchronously. once btrfs_commit_transaction_async
1132 * returns, any subsequent transaction will not be allowed to join.
1134 struct btrfs_async_commit
{
1135 struct btrfs_trans_handle
*newtrans
;
1136 struct btrfs_root
*root
;
1137 struct delayed_work work
;
1140 static void do_async_commit(struct work_struct
*work
)
1142 struct btrfs_async_commit
*ac
=
1143 container_of(work
, struct btrfs_async_commit
, work
.work
);
1145 btrfs_commit_transaction(ac
->newtrans
, ac
->root
);
1149 int btrfs_commit_transaction_async(struct btrfs_trans_handle
*trans
,
1150 struct btrfs_root
*root
,
1151 int wait_for_unblock
)
1153 struct btrfs_async_commit
*ac
;
1154 struct btrfs_transaction
*cur_trans
;
1156 ac
= kmalloc(sizeof(*ac
), GFP_NOFS
);
1160 INIT_DELAYED_WORK(&ac
->work
, do_async_commit
);
1162 ac
->newtrans
= btrfs_join_transaction(root
);
1163 if (IS_ERR(ac
->newtrans
)) {
1164 int err
= PTR_ERR(ac
->newtrans
);
1169 /* take transaction reference */
1170 cur_trans
= trans
->transaction
;
1171 atomic_inc(&cur_trans
->use_count
);
1173 btrfs_end_transaction(trans
, root
);
1174 schedule_delayed_work(&ac
->work
, 0);
1176 /* wait for transaction to start and unblock */
1177 if (wait_for_unblock
)
1178 wait_current_trans_commit_start_and_unblock(root
, cur_trans
);
1180 wait_current_trans_commit_start(root
, cur_trans
);
1182 if (current
->journal_info
== trans
)
1183 current
->journal_info
= NULL
;
1185 put_transaction(cur_trans
);
1190 static void cleanup_transaction(struct btrfs_trans_handle
*trans
,
1191 struct btrfs_root
*root
)
1193 struct btrfs_transaction
*cur_trans
= trans
->transaction
;
1195 WARN_ON(trans
->use_count
> 1);
1197 spin_lock(&root
->fs_info
->trans_lock
);
1198 list_del_init(&cur_trans
->list
);
1199 spin_unlock(&root
->fs_info
->trans_lock
);
1201 btrfs_cleanup_one_transaction(trans
->transaction
, root
);
1203 put_transaction(cur_trans
);
1204 put_transaction(cur_trans
);
1206 trace_btrfs_transaction_commit(root
);
1208 btrfs_scrub_continue(root
);
1210 if (current
->journal_info
== trans
)
1211 current
->journal_info
= NULL
;
1213 kmem_cache_free(btrfs_trans_handle_cachep
, trans
);
1217 * btrfs_transaction state sequence:
1218 * in_commit = 0, blocked = 0 (initial)
1219 * in_commit = 1, blocked = 1
1223 int btrfs_commit_transaction(struct btrfs_trans_handle
*trans
,
1224 struct btrfs_root
*root
)
1226 unsigned long joined
= 0;
1227 struct btrfs_transaction
*cur_trans
= trans
->transaction
;
1228 struct btrfs_transaction
*prev_trans
= NULL
;
1231 int should_grow
= 0;
1232 unsigned long now
= get_seconds();
1233 int flush_on_commit
= btrfs_test_opt(root
, FLUSHONCOMMIT
);
1235 btrfs_run_ordered_operations(root
, 0);
1237 btrfs_trans_release_metadata(trans
, root
);
1238 trans
->block_rsv
= NULL
;
1240 if (cur_trans
->aborted
)
1241 goto cleanup_transaction
;
1243 /* make a pass through all the delayed refs we have so far
1244 * any runnings procs may add more while we are here
1246 ret
= btrfs_run_delayed_refs(trans
, root
, 0);
1248 goto cleanup_transaction
;
1250 cur_trans
= trans
->transaction
;
1253 * set the flushing flag so procs in this transaction have to
1254 * start sending their work down.
1256 cur_trans
->delayed_refs
.flushing
= 1;
1258 ret
= btrfs_run_delayed_refs(trans
, root
, 0);
1260 goto cleanup_transaction
;
1262 spin_lock(&cur_trans
->commit_lock
);
1263 if (cur_trans
->in_commit
) {
1264 spin_unlock(&cur_trans
->commit_lock
);
1265 atomic_inc(&cur_trans
->use_count
);
1266 ret
= btrfs_end_transaction(trans
, root
);
1268 wait_for_commit(root
, cur_trans
);
1270 put_transaction(cur_trans
);
1275 trans
->transaction
->in_commit
= 1;
1276 trans
->transaction
->blocked
= 1;
1277 spin_unlock(&cur_trans
->commit_lock
);
1278 wake_up(&root
->fs_info
->transaction_blocked_wait
);
1280 spin_lock(&root
->fs_info
->trans_lock
);
1281 if (cur_trans
->list
.prev
!= &root
->fs_info
->trans_list
) {
1282 prev_trans
= list_entry(cur_trans
->list
.prev
,
1283 struct btrfs_transaction
, list
);
1284 if (!prev_trans
->commit_done
) {
1285 atomic_inc(&prev_trans
->use_count
);
1286 spin_unlock(&root
->fs_info
->trans_lock
);
1288 wait_for_commit(root
, prev_trans
);
1290 put_transaction(prev_trans
);
1292 spin_unlock(&root
->fs_info
->trans_lock
);
1295 spin_unlock(&root
->fs_info
->trans_lock
);
1298 if (now
< cur_trans
->start_time
|| now
- cur_trans
->start_time
< 1)
1302 int snap_pending
= 0;
1304 joined
= cur_trans
->num_joined
;
1305 if (!list_empty(&trans
->transaction
->pending_snapshots
))
1308 WARN_ON(cur_trans
!= trans
->transaction
);
1310 if (flush_on_commit
|| snap_pending
) {
1311 btrfs_start_delalloc_inodes(root
, 1);
1312 btrfs_wait_ordered_extents(root
, 0, 1);
1315 ret
= btrfs_run_delayed_items(trans
, root
);
1317 goto cleanup_transaction
;
1320 * rename don't use btrfs_join_transaction, so, once we
1321 * set the transaction to blocked above, we aren't going
1322 * to get any new ordered operations. We can safely run
1323 * it here and no for sure that nothing new will be added
1326 btrfs_run_ordered_operations(root
, 1);
1328 prepare_to_wait(&cur_trans
->writer_wait
, &wait
,
1329 TASK_UNINTERRUPTIBLE
);
1331 if (atomic_read(&cur_trans
->num_writers
) > 1)
1332 schedule_timeout(MAX_SCHEDULE_TIMEOUT
);
1333 else if (should_grow
)
1334 schedule_timeout(1);
1336 finish_wait(&cur_trans
->writer_wait
, &wait
);
1337 } while (atomic_read(&cur_trans
->num_writers
) > 1 ||
1338 (should_grow
&& cur_trans
->num_joined
!= joined
));
1341 * Ok now we need to make sure to block out any other joins while we
1342 * commit the transaction. We could have started a join before setting
1343 * no_join so make sure to wait for num_writers to == 1 again.
1345 spin_lock(&root
->fs_info
->trans_lock
);
1346 root
->fs_info
->trans_no_join
= 1;
1347 spin_unlock(&root
->fs_info
->trans_lock
);
1348 wait_event(cur_trans
->writer_wait
,
1349 atomic_read(&cur_trans
->num_writers
) == 1);
1352 * the reloc mutex makes sure that we stop
1353 * the balancing code from coming in and moving
1354 * extents around in the middle of the commit
1356 mutex_lock(&root
->fs_info
->reloc_mutex
);
1358 ret
= btrfs_run_delayed_items(trans
, root
);
1360 mutex_unlock(&root
->fs_info
->reloc_mutex
);
1361 goto cleanup_transaction
;
1364 ret
= create_pending_snapshots(trans
, root
->fs_info
);
1366 mutex_unlock(&root
->fs_info
->reloc_mutex
);
1367 goto cleanup_transaction
;
1370 ret
= btrfs_run_delayed_refs(trans
, root
, (unsigned long)-1);
1372 mutex_unlock(&root
->fs_info
->reloc_mutex
);
1373 goto cleanup_transaction
;
1377 * make sure none of the code above managed to slip in a
1380 btrfs_assert_delayed_root_empty(root
);
1382 WARN_ON(cur_trans
!= trans
->transaction
);
1384 btrfs_scrub_pause(root
);
1385 /* btrfs_commit_tree_roots is responsible for getting the
1386 * various roots consistent with each other. Every pointer
1387 * in the tree of tree roots has to point to the most up to date
1388 * root for every subvolume and other tree. So, we have to keep
1389 * the tree logging code from jumping in and changing any
1392 * At this point in the commit, there can't be any tree-log
1393 * writers, but a little lower down we drop the trans mutex
1394 * and let new people in. By holding the tree_log_mutex
1395 * from now until after the super is written, we avoid races
1396 * with the tree-log code.
1398 mutex_lock(&root
->fs_info
->tree_log_mutex
);
1400 ret
= commit_fs_roots(trans
, root
);
1402 mutex_unlock(&root
->fs_info
->tree_log_mutex
);
1403 goto cleanup_transaction
;
1406 /* commit_fs_roots gets rid of all the tree log roots, it is now
1407 * safe to free the root of tree log roots
1409 btrfs_free_log_root_tree(trans
, root
->fs_info
);
1411 ret
= commit_cowonly_roots(trans
, root
);
1413 mutex_unlock(&root
->fs_info
->tree_log_mutex
);
1414 goto cleanup_transaction
;
1417 btrfs_prepare_extent_commit(trans
, root
);
1419 cur_trans
= root
->fs_info
->running_transaction
;
1421 btrfs_set_root_node(&root
->fs_info
->tree_root
->root_item
,
1422 root
->fs_info
->tree_root
->node
);
1423 switch_commit_root(root
->fs_info
->tree_root
);
1425 btrfs_set_root_node(&root
->fs_info
->chunk_root
->root_item
,
1426 root
->fs_info
->chunk_root
->node
);
1427 switch_commit_root(root
->fs_info
->chunk_root
);
1429 update_super_roots(root
);
1431 if (!root
->fs_info
->log_root_recovering
) {
1432 btrfs_set_super_log_root(root
->fs_info
->super_copy
, 0);
1433 btrfs_set_super_log_root_level(root
->fs_info
->super_copy
, 0);
1436 memcpy(root
->fs_info
->super_for_commit
, root
->fs_info
->super_copy
,
1437 sizeof(*root
->fs_info
->super_copy
));
1439 trans
->transaction
->blocked
= 0;
1440 spin_lock(&root
->fs_info
->trans_lock
);
1441 root
->fs_info
->running_transaction
= NULL
;
1442 root
->fs_info
->trans_no_join
= 0;
1443 spin_unlock(&root
->fs_info
->trans_lock
);
1444 mutex_unlock(&root
->fs_info
->reloc_mutex
);
1446 wake_up(&root
->fs_info
->transaction_wait
);
1448 ret
= btrfs_write_and_wait_transaction(trans
, root
);
1450 btrfs_error(root
->fs_info
, ret
,
1451 "Error while writing out transaction.");
1452 mutex_unlock(&root
->fs_info
->tree_log_mutex
);
1453 goto cleanup_transaction
;
1456 ret
= write_ctree_super(trans
, root
, 0);
1458 mutex_unlock(&root
->fs_info
->tree_log_mutex
);
1459 goto cleanup_transaction
;
1463 * the super is written, we can safely allow the tree-loggers
1464 * to go about their business
1466 mutex_unlock(&root
->fs_info
->tree_log_mutex
);
1468 btrfs_finish_extent_commit(trans
, root
);
1470 cur_trans
->commit_done
= 1;
1472 root
->fs_info
->last_trans_committed
= cur_trans
->transid
;
1474 wake_up(&cur_trans
->commit_wait
);
1476 spin_lock(&root
->fs_info
->trans_lock
);
1477 list_del_init(&cur_trans
->list
);
1478 spin_unlock(&root
->fs_info
->trans_lock
);
1480 put_transaction(cur_trans
);
1481 put_transaction(cur_trans
);
1483 trace_btrfs_transaction_commit(root
);
1485 btrfs_scrub_continue(root
);
1487 if (current
->journal_info
== trans
)
1488 current
->journal_info
= NULL
;
1490 kmem_cache_free(btrfs_trans_handle_cachep
, trans
);
1492 if (current
!= root
->fs_info
->transaction_kthread
)
1493 btrfs_run_delayed_iputs(root
);
1497 cleanup_transaction
:
1498 btrfs_printk(root
->fs_info
, "Skipping commit of aborted transaction.\n");
1500 if (current
->journal_info
== trans
)
1501 current
->journal_info
= NULL
;
1502 cleanup_transaction(trans
, root
);
1508 * interface function to delete all the snapshots we have scheduled for deletion
1510 int btrfs_clean_old_snapshots(struct btrfs_root
*root
)
1513 struct btrfs_fs_info
*fs_info
= root
->fs_info
;
1515 spin_lock(&fs_info
->trans_lock
);
1516 list_splice_init(&fs_info
->dead_roots
, &list
);
1517 spin_unlock(&fs_info
->trans_lock
);
1519 while (!list_empty(&list
)) {
1522 root
= list_entry(list
.next
, struct btrfs_root
, root_list
);
1523 list_del(&root
->root_list
);
1525 btrfs_kill_all_delayed_nodes(root
);
1527 if (btrfs_header_backref_rev(root
->node
) <
1528 BTRFS_MIXED_BACKREF_REV
)
1529 ret
= btrfs_drop_snapshot(root
, NULL
, 0, 0);
1531 ret
=btrfs_drop_snapshot(root
, NULL
, 1, 0);