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>
25 #include <linux/uuid.h>
28 #include "transaction.h"
31 #include "inode-map.h"
33 #include "dev-replace.h"
35 #define BTRFS_ROOT_TRANS_TAG 0
37 void put_transaction(struct btrfs_transaction
*transaction
)
39 WARN_ON(atomic_read(&transaction
->use_count
) == 0);
40 if (atomic_dec_and_test(&transaction
->use_count
)) {
41 BUG_ON(!list_empty(&transaction
->list
));
42 WARN_ON(transaction
->delayed_refs
.root
.rb_node
);
43 memset(transaction
, 0, sizeof(*transaction
));
44 kmem_cache_free(btrfs_transaction_cachep
, transaction
);
48 static noinline
void switch_commit_root(struct btrfs_root
*root
)
50 free_extent_buffer(root
->commit_root
);
51 root
->commit_root
= btrfs_root_node(root
);
55 * either allocate a new transaction or hop into the existing one
57 static noinline
int join_transaction(struct btrfs_root
*root
, int type
)
59 struct btrfs_transaction
*cur_trans
;
60 struct btrfs_fs_info
*fs_info
= root
->fs_info
;
62 spin_lock(&fs_info
->trans_lock
);
64 /* The file system has been taken offline. No new transactions. */
65 if (fs_info
->fs_state
& BTRFS_SUPER_FLAG_ERROR
) {
66 spin_unlock(&fs_info
->trans_lock
);
70 if (fs_info
->trans_no_join
) {
72 * If we are JOIN_NOLOCK we're already committing a current
73 * transaction, we just need a handle to deal with something
74 * when committing the transaction, such as inode cache and
75 * space cache. It is a special case.
77 if (type
!= TRANS_JOIN_NOLOCK
) {
78 spin_unlock(&fs_info
->trans_lock
);
83 cur_trans
= fs_info
->running_transaction
;
85 if (cur_trans
->aborted
) {
86 spin_unlock(&fs_info
->trans_lock
);
87 return cur_trans
->aborted
;
89 atomic_inc(&cur_trans
->use_count
);
90 atomic_inc(&cur_trans
->num_writers
);
91 cur_trans
->num_joined
++;
92 spin_unlock(&fs_info
->trans_lock
);
95 spin_unlock(&fs_info
->trans_lock
);
98 * If we are ATTACH, we just want to catch the current transaction,
99 * and commit it. If there is no transaction, just return ENOENT.
101 if (type
== TRANS_ATTACH
)
104 cur_trans
= kmem_cache_alloc(btrfs_transaction_cachep
, GFP_NOFS
);
108 spin_lock(&fs_info
->trans_lock
);
109 if (fs_info
->running_transaction
) {
111 * someone started a transaction after we unlocked. Make sure
112 * to redo the trans_no_join checks above
114 kmem_cache_free(btrfs_transaction_cachep
, cur_trans
);
115 cur_trans
= fs_info
->running_transaction
;
117 } else if (fs_info
->fs_state
& BTRFS_SUPER_FLAG_ERROR
) {
118 spin_unlock(&fs_info
->trans_lock
);
119 kmem_cache_free(btrfs_transaction_cachep
, cur_trans
);
123 atomic_set(&cur_trans
->num_writers
, 1);
124 cur_trans
->num_joined
= 0;
125 init_waitqueue_head(&cur_trans
->writer_wait
);
126 init_waitqueue_head(&cur_trans
->commit_wait
);
127 cur_trans
->in_commit
= 0;
128 cur_trans
->blocked
= 0;
130 * One for this trans handle, one so it will live on until we
131 * commit the transaction.
133 atomic_set(&cur_trans
->use_count
, 2);
134 cur_trans
->commit_done
= 0;
135 cur_trans
->start_time
= get_seconds();
137 cur_trans
->delayed_refs
.root
= RB_ROOT
;
138 cur_trans
->delayed_refs
.num_entries
= 0;
139 cur_trans
->delayed_refs
.num_heads_ready
= 0;
140 cur_trans
->delayed_refs
.num_heads
= 0;
141 cur_trans
->delayed_refs
.flushing
= 0;
142 cur_trans
->delayed_refs
.run_delayed_start
= 0;
145 * although the tree mod log is per file system and not per transaction,
146 * the log must never go across transaction boundaries.
149 if (!list_empty(&fs_info
->tree_mod_seq_list
))
150 WARN(1, KERN_ERR
"btrfs: tree_mod_seq_list not empty when "
151 "creating a fresh transaction\n");
152 if (!RB_EMPTY_ROOT(&fs_info
->tree_mod_log
))
153 WARN(1, KERN_ERR
"btrfs: tree_mod_log rb tree not empty when "
154 "creating a fresh transaction\n");
155 atomic_set(&fs_info
->tree_mod_seq
, 0);
157 spin_lock_init(&cur_trans
->commit_lock
);
158 spin_lock_init(&cur_trans
->delayed_refs
.lock
);
159 atomic_set(&cur_trans
->delayed_refs
.procs_running_refs
, 0);
160 atomic_set(&cur_trans
->delayed_refs
.ref_seq
, 0);
161 init_waitqueue_head(&cur_trans
->delayed_refs
.wait
);
163 INIT_LIST_HEAD(&cur_trans
->pending_snapshots
);
164 list_add_tail(&cur_trans
->list
, &fs_info
->trans_list
);
165 extent_io_tree_init(&cur_trans
->dirty_pages
,
166 fs_info
->btree_inode
->i_mapping
);
167 fs_info
->generation
++;
168 cur_trans
->transid
= fs_info
->generation
;
169 fs_info
->running_transaction
= cur_trans
;
170 cur_trans
->aborted
= 0;
171 spin_unlock(&fs_info
->trans_lock
);
177 * this does all the record keeping required to make sure that a reference
178 * counted root is properly recorded in a given transaction. This is required
179 * to make sure the old root from before we joined the transaction is deleted
180 * when the transaction commits
182 static int record_root_in_trans(struct btrfs_trans_handle
*trans
,
183 struct btrfs_root
*root
)
185 if (root
->ref_cows
&& root
->last_trans
< trans
->transid
) {
186 WARN_ON(root
== root
->fs_info
->extent_root
);
187 WARN_ON(root
->commit_root
!= root
->node
);
190 * see below for in_trans_setup usage rules
191 * we have the reloc mutex held now, so there
192 * is only one writer in this function
194 root
->in_trans_setup
= 1;
196 /* make sure readers find in_trans_setup before
197 * they find our root->last_trans update
201 spin_lock(&root
->fs_info
->fs_roots_radix_lock
);
202 if (root
->last_trans
== trans
->transid
) {
203 spin_unlock(&root
->fs_info
->fs_roots_radix_lock
);
206 radix_tree_tag_set(&root
->fs_info
->fs_roots_radix
,
207 (unsigned long)root
->root_key
.objectid
,
208 BTRFS_ROOT_TRANS_TAG
);
209 spin_unlock(&root
->fs_info
->fs_roots_radix_lock
);
210 root
->last_trans
= trans
->transid
;
212 /* this is pretty tricky. We don't want to
213 * take the relocation lock in btrfs_record_root_in_trans
214 * unless we're really doing the first setup for this root in
217 * Normally we'd use root->last_trans as a flag to decide
218 * if we want to take the expensive mutex.
220 * But, we have to set root->last_trans before we
221 * init the relocation root, otherwise, we trip over warnings
222 * in ctree.c. The solution used here is to flag ourselves
223 * with root->in_trans_setup. When this is 1, we're still
224 * fixing up the reloc trees and everyone must wait.
226 * When this is zero, they can trust root->last_trans and fly
227 * through btrfs_record_root_in_trans without having to take the
228 * lock. smp_wmb() makes sure that all the writes above are
229 * done before we pop in the zero below
231 btrfs_init_reloc_root(trans
, root
);
233 root
->in_trans_setup
= 0;
239 int btrfs_record_root_in_trans(struct btrfs_trans_handle
*trans
,
240 struct btrfs_root
*root
)
246 * see record_root_in_trans for comments about in_trans_setup usage
250 if (root
->last_trans
== trans
->transid
&&
251 !root
->in_trans_setup
)
254 mutex_lock(&root
->fs_info
->reloc_mutex
);
255 record_root_in_trans(trans
, root
);
256 mutex_unlock(&root
->fs_info
->reloc_mutex
);
261 /* wait for commit against the current transaction to become unblocked
262 * when this is done, it is safe to start a new transaction, but the current
263 * transaction might not be fully on disk.
265 static void wait_current_trans(struct btrfs_root
*root
)
267 struct btrfs_transaction
*cur_trans
;
269 spin_lock(&root
->fs_info
->trans_lock
);
270 cur_trans
= root
->fs_info
->running_transaction
;
271 if (cur_trans
&& cur_trans
->blocked
) {
272 atomic_inc(&cur_trans
->use_count
);
273 spin_unlock(&root
->fs_info
->trans_lock
);
275 wait_event(root
->fs_info
->transaction_wait
,
276 !cur_trans
->blocked
);
277 put_transaction(cur_trans
);
279 spin_unlock(&root
->fs_info
->trans_lock
);
283 static int may_wait_transaction(struct btrfs_root
*root
, int type
)
285 if (root
->fs_info
->log_root_recovering
)
288 if (type
== TRANS_USERSPACE
)
291 if (type
== TRANS_START
&&
292 !atomic_read(&root
->fs_info
->open_ioctl_trans
))
298 static struct btrfs_trans_handle
*
299 start_transaction(struct btrfs_root
*root
, u64 num_items
, int type
,
300 enum btrfs_reserve_flush_enum flush
)
302 struct btrfs_trans_handle
*h
;
303 struct btrfs_transaction
*cur_trans
;
306 u64 qgroup_reserved
= 0;
308 if (root
->fs_info
->fs_state
& BTRFS_SUPER_FLAG_ERROR
)
309 return ERR_PTR(-EROFS
);
311 if (current
->journal_info
) {
312 WARN_ON(type
!= TRANS_JOIN
&& type
!= TRANS_JOIN_NOLOCK
);
313 h
= current
->journal_info
;
315 WARN_ON(h
->use_count
> 2);
316 h
->orig_rsv
= h
->block_rsv
;
322 * Do the reservation before we join the transaction so we can do all
323 * the appropriate flushing if need be.
325 if (num_items
> 0 && root
!= root
->fs_info
->chunk_root
) {
326 if (root
->fs_info
->quota_enabled
&&
327 is_fstree(root
->root_key
.objectid
)) {
328 qgroup_reserved
= num_items
* root
->leafsize
;
329 ret
= btrfs_qgroup_reserve(root
, qgroup_reserved
);
334 num_bytes
= btrfs_calc_trans_metadata_size(root
, num_items
);
335 ret
= btrfs_block_rsv_add(root
,
336 &root
->fs_info
->trans_block_rsv
,
342 h
= kmem_cache_alloc(btrfs_trans_handle_cachep
, GFP_NOFS
);
344 return ERR_PTR(-ENOMEM
);
347 * If we are JOIN_NOLOCK we're already committing a transaction and
348 * waiting on this guy, so we don't need to do the sb_start_intwrite
349 * because we're already holding a ref. We need this because we could
350 * have raced in and did an fsync() on a file which can kick a commit
351 * and then we deadlock with somebody doing a freeze.
353 * If we are ATTACH, it means we just want to catch the current
354 * transaction and commit it, so we needn't do sb_start_intwrite().
356 if (type
< TRANS_JOIN_NOLOCK
)
357 sb_start_intwrite(root
->fs_info
->sb
);
359 if (may_wait_transaction(root
, type
))
360 wait_current_trans(root
);
363 ret
= join_transaction(root
, type
);
365 wait_current_trans(root
);
366 } while (ret
== -EBUSY
);
369 /* We must get the transaction if we are JOIN_NOLOCK. */
370 BUG_ON(type
== TRANS_JOIN_NOLOCK
);
372 if (type
< TRANS_JOIN_NOLOCK
)
373 sb_end_intwrite(root
->fs_info
->sb
);
374 kmem_cache_free(btrfs_trans_handle_cachep
, h
);
378 cur_trans
= root
->fs_info
->running_transaction
;
380 h
->transid
= cur_trans
->transid
;
381 h
->transaction
= cur_trans
;
383 h
->bytes_reserved
= 0;
385 h
->delayed_ref_updates
= 0;
391 h
->qgroup_reserved
= qgroup_reserved
;
392 h
->delayed_ref_elem
.seq
= 0;
394 INIT_LIST_HEAD(&h
->qgroup_ref_list
);
395 INIT_LIST_HEAD(&h
->new_bgs
);
398 if (cur_trans
->blocked
&& may_wait_transaction(root
, type
)) {
399 btrfs_commit_transaction(h
, root
);
404 trace_btrfs_space_reservation(root
->fs_info
, "transaction",
405 h
->transid
, num_bytes
, 1);
406 h
->block_rsv
= &root
->fs_info
->trans_block_rsv
;
407 h
->bytes_reserved
= num_bytes
;
411 btrfs_record_root_in_trans(h
, root
);
413 if (!current
->journal_info
&& type
!= TRANS_USERSPACE
)
414 current
->journal_info
= h
;
418 struct btrfs_trans_handle
*btrfs_start_transaction(struct btrfs_root
*root
,
421 return start_transaction(root
, num_items
, TRANS_START
,
422 BTRFS_RESERVE_FLUSH_ALL
);
425 struct btrfs_trans_handle
*btrfs_start_transaction_lflush(
426 struct btrfs_root
*root
, int num_items
)
428 return start_transaction(root
, num_items
, TRANS_START
,
429 BTRFS_RESERVE_FLUSH_LIMIT
);
432 struct btrfs_trans_handle
*btrfs_join_transaction(struct btrfs_root
*root
)
434 return start_transaction(root
, 0, TRANS_JOIN
, 0);
437 struct btrfs_trans_handle
*btrfs_join_transaction_nolock(struct btrfs_root
*root
)
439 return start_transaction(root
, 0, TRANS_JOIN_NOLOCK
, 0);
442 struct btrfs_trans_handle
*btrfs_start_ioctl_transaction(struct btrfs_root
*root
)
444 return start_transaction(root
, 0, TRANS_USERSPACE
, 0);
447 struct btrfs_trans_handle
*btrfs_attach_transaction(struct btrfs_root
*root
)
449 return start_transaction(root
, 0, TRANS_ATTACH
, 0);
452 /* wait for a transaction commit to be fully complete */
453 static noinline
void wait_for_commit(struct btrfs_root
*root
,
454 struct btrfs_transaction
*commit
)
456 wait_event(commit
->commit_wait
, commit
->commit_done
);
459 int btrfs_wait_for_commit(struct btrfs_root
*root
, u64 transid
)
461 struct btrfs_transaction
*cur_trans
= NULL
, *t
;
465 if (transid
<= root
->fs_info
->last_trans_committed
)
469 /* find specified transaction */
470 spin_lock(&root
->fs_info
->trans_lock
);
471 list_for_each_entry(t
, &root
->fs_info
->trans_list
, list
) {
472 if (t
->transid
== transid
) {
474 atomic_inc(&cur_trans
->use_count
);
478 if (t
->transid
> transid
) {
483 spin_unlock(&root
->fs_info
->trans_lock
);
484 /* The specified transaction doesn't exist */
488 /* find newest transaction that is committing | committed */
489 spin_lock(&root
->fs_info
->trans_lock
);
490 list_for_each_entry_reverse(t
, &root
->fs_info
->trans_list
,
496 atomic_inc(&cur_trans
->use_count
);
500 spin_unlock(&root
->fs_info
->trans_lock
);
502 goto out
; /* nothing committing|committed */
505 wait_for_commit(root
, cur_trans
);
506 put_transaction(cur_trans
);
511 void btrfs_throttle(struct btrfs_root
*root
)
513 if (!atomic_read(&root
->fs_info
->open_ioctl_trans
))
514 wait_current_trans(root
);
517 static int should_end_transaction(struct btrfs_trans_handle
*trans
,
518 struct btrfs_root
*root
)
522 ret
= btrfs_block_rsv_check(root
, &root
->fs_info
->global_block_rsv
, 5);
526 int btrfs_should_end_transaction(struct btrfs_trans_handle
*trans
,
527 struct btrfs_root
*root
)
529 struct btrfs_transaction
*cur_trans
= trans
->transaction
;
534 if (cur_trans
->blocked
|| cur_trans
->delayed_refs
.flushing
)
537 updates
= trans
->delayed_ref_updates
;
538 trans
->delayed_ref_updates
= 0;
540 err
= btrfs_run_delayed_refs(trans
, root
, updates
);
541 if (err
) /* Error code will also eval true */
545 return should_end_transaction(trans
, root
);
548 static int __btrfs_end_transaction(struct btrfs_trans_handle
*trans
,
549 struct btrfs_root
*root
, int throttle
)
551 struct btrfs_transaction
*cur_trans
= trans
->transaction
;
552 struct btrfs_fs_info
*info
= root
->fs_info
;
554 int lock
= (trans
->type
!= TRANS_JOIN_NOLOCK
);
557 if (--trans
->use_count
) {
558 trans
->block_rsv
= trans
->orig_rsv
;
563 * do the qgroup accounting as early as possible
565 err
= btrfs_delayed_refs_qgroup_accounting(trans
, info
);
567 btrfs_trans_release_metadata(trans
, root
);
568 trans
->block_rsv
= NULL
;
570 * the same root has to be passed to start_transaction and
571 * end_transaction. Subvolume quota depends on this.
573 WARN_ON(trans
->root
!= root
);
575 if (trans
->qgroup_reserved
) {
576 btrfs_qgroup_free(root
, trans
->qgroup_reserved
);
577 trans
->qgroup_reserved
= 0;
580 if (!list_empty(&trans
->new_bgs
))
581 btrfs_create_pending_block_groups(trans
, root
);
584 unsigned long cur
= trans
->delayed_ref_updates
;
585 trans
->delayed_ref_updates
= 0;
587 trans
->transaction
->delayed_refs
.num_heads_ready
> 64) {
588 trans
->delayed_ref_updates
= 0;
589 btrfs_run_delayed_refs(trans
, root
, cur
);
596 btrfs_trans_release_metadata(trans
, root
);
597 trans
->block_rsv
= NULL
;
599 if (!list_empty(&trans
->new_bgs
))
600 btrfs_create_pending_block_groups(trans
, root
);
602 if (lock
&& !atomic_read(&root
->fs_info
->open_ioctl_trans
) &&
603 should_end_transaction(trans
, root
)) {
604 trans
->transaction
->blocked
= 1;
608 if (lock
&& cur_trans
->blocked
&& !cur_trans
->in_commit
) {
611 * We may race with somebody else here so end up having
612 * to call end_transaction on ourselves again, so inc
616 return btrfs_commit_transaction(trans
, root
);
618 wake_up_process(info
->transaction_kthread
);
622 if (trans
->type
< TRANS_JOIN_NOLOCK
)
623 sb_end_intwrite(root
->fs_info
->sb
);
625 WARN_ON(cur_trans
!= info
->running_transaction
);
626 WARN_ON(atomic_read(&cur_trans
->num_writers
) < 1);
627 atomic_dec(&cur_trans
->num_writers
);
630 if (waitqueue_active(&cur_trans
->writer_wait
))
631 wake_up(&cur_trans
->writer_wait
);
632 put_transaction(cur_trans
);
634 if (current
->journal_info
== trans
)
635 current
->journal_info
= NULL
;
638 btrfs_run_delayed_iputs(root
);
640 if (trans
->aborted
||
641 root
->fs_info
->fs_state
& BTRFS_SUPER_FLAG_ERROR
) {
644 assert_qgroups_uptodate(trans
);
646 memset(trans
, 0, sizeof(*trans
));
647 kmem_cache_free(btrfs_trans_handle_cachep
, trans
);
651 int btrfs_end_transaction(struct btrfs_trans_handle
*trans
,
652 struct btrfs_root
*root
)
656 ret
= __btrfs_end_transaction(trans
, root
, 0);
662 int btrfs_end_transaction_throttle(struct btrfs_trans_handle
*trans
,
663 struct btrfs_root
*root
)
667 ret
= __btrfs_end_transaction(trans
, root
, 1);
673 int btrfs_end_transaction_dmeta(struct btrfs_trans_handle
*trans
,
674 struct btrfs_root
*root
)
676 return __btrfs_end_transaction(trans
, root
, 1);
680 * when btree blocks are allocated, they have some corresponding bits set for
681 * them in one of two extent_io trees. This is used to make sure all of
682 * those extents are sent to disk but does not wait on them
684 int btrfs_write_marked_extents(struct btrfs_root
*root
,
685 struct extent_io_tree
*dirty_pages
, int mark
)
689 struct address_space
*mapping
= root
->fs_info
->btree_inode
->i_mapping
;
690 struct extent_state
*cached_state
= NULL
;
693 struct blk_plug plug
;
695 blk_start_plug(&plug
);
696 while (!find_first_extent_bit(dirty_pages
, start
, &start
, &end
,
697 mark
, &cached_state
)) {
698 convert_extent_bit(dirty_pages
, start
, end
, EXTENT_NEED_WAIT
,
699 mark
, &cached_state
, GFP_NOFS
);
701 err
= filemap_fdatawrite_range(mapping
, start
, end
);
709 blk_finish_plug(&plug
);
714 * when btree blocks are allocated, they have some corresponding bits set for
715 * them in one of two extent_io trees. This is used to make sure all of
716 * those extents are on disk for transaction or log commit. We wait
717 * on all the pages and clear them from the dirty pages state tree
719 int btrfs_wait_marked_extents(struct btrfs_root
*root
,
720 struct extent_io_tree
*dirty_pages
, int mark
)
724 struct address_space
*mapping
= root
->fs_info
->btree_inode
->i_mapping
;
725 struct extent_state
*cached_state
= NULL
;
729 while (!find_first_extent_bit(dirty_pages
, start
, &start
, &end
,
730 EXTENT_NEED_WAIT
, &cached_state
)) {
731 clear_extent_bit(dirty_pages
, start
, end
, EXTENT_NEED_WAIT
,
732 0, 0, &cached_state
, GFP_NOFS
);
733 err
= filemap_fdatawait_range(mapping
, start
, end
);
745 * when btree blocks are allocated, they have some corresponding bits set for
746 * them in one of two extent_io trees. This is used to make sure all of
747 * those extents are on disk for transaction or log commit
749 int btrfs_write_and_wait_marked_extents(struct btrfs_root
*root
,
750 struct extent_io_tree
*dirty_pages
, int mark
)
755 ret
= btrfs_write_marked_extents(root
, dirty_pages
, mark
);
756 ret2
= btrfs_wait_marked_extents(root
, dirty_pages
, mark
);
765 int btrfs_write_and_wait_transaction(struct btrfs_trans_handle
*trans
,
766 struct btrfs_root
*root
)
768 if (!trans
|| !trans
->transaction
) {
769 struct inode
*btree_inode
;
770 btree_inode
= root
->fs_info
->btree_inode
;
771 return filemap_write_and_wait(btree_inode
->i_mapping
);
773 return btrfs_write_and_wait_marked_extents(root
,
774 &trans
->transaction
->dirty_pages
,
779 * this is used to update the root pointer in the tree of tree roots.
781 * But, in the case of the extent allocation tree, updating the root
782 * pointer may allocate blocks which may change the root of the extent
785 * So, this loops and repeats and makes sure the cowonly root didn't
786 * change while the root pointer was being updated in the metadata.
788 static int update_cowonly_root(struct btrfs_trans_handle
*trans
,
789 struct btrfs_root
*root
)
794 struct btrfs_root
*tree_root
= root
->fs_info
->tree_root
;
796 old_root_used
= btrfs_root_used(&root
->root_item
);
797 btrfs_write_dirty_block_groups(trans
, root
);
800 old_root_bytenr
= btrfs_root_bytenr(&root
->root_item
);
801 if (old_root_bytenr
== root
->node
->start
&&
802 old_root_used
== btrfs_root_used(&root
->root_item
))
805 btrfs_set_root_node(&root
->root_item
, root
->node
);
806 ret
= btrfs_update_root(trans
, tree_root
,
812 old_root_used
= btrfs_root_used(&root
->root_item
);
813 ret
= btrfs_write_dirty_block_groups(trans
, root
);
818 if (root
!= root
->fs_info
->extent_root
)
819 switch_commit_root(root
);
825 * update all the cowonly tree roots on disk
827 * The error handling in this function may not be obvious. Any of the
828 * failures will cause the file system to go offline. We still need
829 * to clean up the delayed refs.
831 static noinline
int commit_cowonly_roots(struct btrfs_trans_handle
*trans
,
832 struct btrfs_root
*root
)
834 struct btrfs_fs_info
*fs_info
= root
->fs_info
;
835 struct list_head
*next
;
836 struct extent_buffer
*eb
;
839 ret
= btrfs_run_delayed_refs(trans
, root
, (unsigned long)-1);
843 eb
= btrfs_lock_root_node(fs_info
->tree_root
);
844 ret
= btrfs_cow_block(trans
, fs_info
->tree_root
, eb
, NULL
,
846 btrfs_tree_unlock(eb
);
847 free_extent_buffer(eb
);
852 ret
= btrfs_run_delayed_refs(trans
, root
, (unsigned long)-1);
856 ret
= btrfs_run_dev_stats(trans
, root
->fs_info
);
858 ret
= btrfs_run_dev_replace(trans
, root
->fs_info
);
861 ret
= btrfs_run_qgroups(trans
, root
->fs_info
);
864 /* run_qgroups might have added some more refs */
865 ret
= btrfs_run_delayed_refs(trans
, root
, (unsigned long)-1);
868 while (!list_empty(&fs_info
->dirty_cowonly_roots
)) {
869 next
= fs_info
->dirty_cowonly_roots
.next
;
871 root
= list_entry(next
, struct btrfs_root
, dirty_list
);
873 ret
= update_cowonly_root(trans
, root
);
878 down_write(&fs_info
->extent_commit_sem
);
879 switch_commit_root(fs_info
->extent_root
);
880 up_write(&fs_info
->extent_commit_sem
);
882 btrfs_after_dev_replace_commit(fs_info
);
888 * dead roots are old snapshots that need to be deleted. This allocates
889 * a dirty root struct and adds it into the list of dead roots that need to
892 int btrfs_add_dead_root(struct btrfs_root
*root
)
894 spin_lock(&root
->fs_info
->trans_lock
);
895 list_add(&root
->root_list
, &root
->fs_info
->dead_roots
);
896 spin_unlock(&root
->fs_info
->trans_lock
);
901 * update all the cowonly tree roots on disk
903 static noinline
int commit_fs_roots(struct btrfs_trans_handle
*trans
,
904 struct btrfs_root
*root
)
906 struct btrfs_root
*gang
[8];
907 struct btrfs_fs_info
*fs_info
= root
->fs_info
;
912 spin_lock(&fs_info
->fs_roots_radix_lock
);
914 ret
= radix_tree_gang_lookup_tag(&fs_info
->fs_roots_radix
,
917 BTRFS_ROOT_TRANS_TAG
);
920 for (i
= 0; i
< ret
; i
++) {
922 radix_tree_tag_clear(&fs_info
->fs_roots_radix
,
923 (unsigned long)root
->root_key
.objectid
,
924 BTRFS_ROOT_TRANS_TAG
);
925 spin_unlock(&fs_info
->fs_roots_radix_lock
);
927 btrfs_free_log(trans
, root
);
928 btrfs_update_reloc_root(trans
, root
);
929 btrfs_orphan_commit_root(trans
, root
);
931 btrfs_save_ino_cache(root
, trans
);
933 /* see comments in should_cow_block() */
937 if (root
->commit_root
!= root
->node
) {
938 mutex_lock(&root
->fs_commit_mutex
);
939 switch_commit_root(root
);
940 btrfs_unpin_free_ino(root
);
941 mutex_unlock(&root
->fs_commit_mutex
);
943 btrfs_set_root_node(&root
->root_item
,
947 err
= btrfs_update_root(trans
, fs_info
->tree_root
,
950 spin_lock(&fs_info
->fs_roots_radix_lock
);
955 spin_unlock(&fs_info
->fs_roots_radix_lock
);
960 * defrag a given btree. If cacheonly == 1, this won't read from the disk,
961 * otherwise every leaf in the btree is read and defragged.
963 int btrfs_defrag_root(struct btrfs_root
*root
, int cacheonly
)
965 struct btrfs_fs_info
*info
= root
->fs_info
;
966 struct btrfs_trans_handle
*trans
;
969 if (xchg(&root
->defrag_running
, 1))
973 trans
= btrfs_start_transaction(root
, 0);
975 return PTR_ERR(trans
);
977 ret
= btrfs_defrag_leaves(trans
, root
, cacheonly
);
979 btrfs_end_transaction(trans
, root
);
980 btrfs_btree_balance_dirty(info
->tree_root
);
983 if (btrfs_fs_closing(root
->fs_info
) || ret
!= -EAGAIN
)
986 root
->defrag_running
= 0;
991 * new snapshots need to be created at a very specific time in the
992 * transaction commit. This does the actual creation
994 static noinline
int create_pending_snapshot(struct btrfs_trans_handle
*trans
,
995 struct btrfs_fs_info
*fs_info
,
996 struct btrfs_pending_snapshot
*pending
)
998 struct btrfs_key key
;
999 struct btrfs_root_item
*new_root_item
;
1000 struct btrfs_root
*tree_root
= fs_info
->tree_root
;
1001 struct btrfs_root
*root
= pending
->root
;
1002 struct btrfs_root
*parent_root
;
1003 struct btrfs_block_rsv
*rsv
;
1004 struct inode
*parent_inode
;
1005 struct btrfs_path
*path
;
1006 struct btrfs_dir_item
*dir_item
;
1007 struct dentry
*parent
;
1008 struct dentry
*dentry
;
1009 struct extent_buffer
*tmp
;
1010 struct extent_buffer
*old
;
1011 struct timespec cur_time
= CURRENT_TIME
;
1019 path
= btrfs_alloc_path();
1021 ret
= pending
->error
= -ENOMEM
;
1022 goto path_alloc_fail
;
1025 new_root_item
= kmalloc(sizeof(*new_root_item
), GFP_NOFS
);
1026 if (!new_root_item
) {
1027 ret
= pending
->error
= -ENOMEM
;
1028 goto root_item_alloc_fail
;
1031 ret
= btrfs_find_free_objectid(tree_root
, &objectid
);
1033 pending
->error
= ret
;
1034 goto no_free_objectid
;
1037 btrfs_reloc_pre_snapshot(trans
, pending
, &to_reserve
);
1039 if (to_reserve
> 0) {
1040 ret
= btrfs_block_rsv_add(root
, &pending
->block_rsv
,
1042 BTRFS_RESERVE_NO_FLUSH
);
1044 pending
->error
= ret
;
1045 goto no_free_objectid
;
1049 ret
= btrfs_qgroup_inherit(trans
, fs_info
, root
->root_key
.objectid
,
1050 objectid
, pending
->inherit
);
1052 pending
->error
= ret
;
1053 goto no_free_objectid
;
1056 key
.objectid
= objectid
;
1057 key
.offset
= (u64
)-1;
1058 key
.type
= BTRFS_ROOT_ITEM_KEY
;
1060 rsv
= trans
->block_rsv
;
1061 trans
->block_rsv
= &pending
->block_rsv
;
1063 dentry
= pending
->dentry
;
1064 parent
= dget_parent(dentry
);
1065 parent_inode
= parent
->d_inode
;
1066 parent_root
= BTRFS_I(parent_inode
)->root
;
1067 record_root_in_trans(trans
, parent_root
);
1070 * insert the directory item
1072 ret
= btrfs_set_inode_index(parent_inode
, &index
);
1073 BUG_ON(ret
); /* -ENOMEM */
1075 /* check if there is a file/dir which has the same name. */
1076 dir_item
= btrfs_lookup_dir_item(NULL
, parent_root
, path
,
1077 btrfs_ino(parent_inode
),
1078 dentry
->d_name
.name
,
1079 dentry
->d_name
.len
, 0);
1080 if (dir_item
!= NULL
&& !IS_ERR(dir_item
)) {
1081 pending
->error
= -EEXIST
;
1083 } else if (IS_ERR(dir_item
)) {
1084 ret
= PTR_ERR(dir_item
);
1085 btrfs_abort_transaction(trans
, root
, ret
);
1088 btrfs_release_path(path
);
1091 * pull in the delayed directory update
1092 * and the delayed inode item
1093 * otherwise we corrupt the FS during
1096 ret
= btrfs_run_delayed_items(trans
, root
);
1097 if (ret
) { /* Transaction aborted */
1098 btrfs_abort_transaction(trans
, root
, ret
);
1102 record_root_in_trans(trans
, root
);
1103 btrfs_set_root_last_snapshot(&root
->root_item
, trans
->transid
);
1104 memcpy(new_root_item
, &root
->root_item
, sizeof(*new_root_item
));
1105 btrfs_check_and_init_root_item(new_root_item
);
1107 root_flags
= btrfs_root_flags(new_root_item
);
1108 if (pending
->readonly
)
1109 root_flags
|= BTRFS_ROOT_SUBVOL_RDONLY
;
1111 root_flags
&= ~BTRFS_ROOT_SUBVOL_RDONLY
;
1112 btrfs_set_root_flags(new_root_item
, root_flags
);
1114 btrfs_set_root_generation_v2(new_root_item
,
1116 uuid_le_gen(&new_uuid
);
1117 memcpy(new_root_item
->uuid
, new_uuid
.b
, BTRFS_UUID_SIZE
);
1118 memcpy(new_root_item
->parent_uuid
, root
->root_item
.uuid
,
1120 new_root_item
->otime
.sec
= cpu_to_le64(cur_time
.tv_sec
);
1121 new_root_item
->otime
.nsec
= cpu_to_le32(cur_time
.tv_nsec
);
1122 btrfs_set_root_otransid(new_root_item
, trans
->transid
);
1123 memset(&new_root_item
->stime
, 0, sizeof(new_root_item
->stime
));
1124 memset(&new_root_item
->rtime
, 0, sizeof(new_root_item
->rtime
));
1125 btrfs_set_root_stransid(new_root_item
, 0);
1126 btrfs_set_root_rtransid(new_root_item
, 0);
1128 old
= btrfs_lock_root_node(root
);
1129 ret
= btrfs_cow_block(trans
, root
, old
, NULL
, 0, &old
);
1131 btrfs_tree_unlock(old
);
1132 free_extent_buffer(old
);
1133 btrfs_abort_transaction(trans
, root
, ret
);
1137 btrfs_set_lock_blocking(old
);
1139 ret
= btrfs_copy_root(trans
, root
, old
, &tmp
, objectid
);
1140 /* clean up in any case */
1141 btrfs_tree_unlock(old
);
1142 free_extent_buffer(old
);
1144 btrfs_abort_transaction(trans
, root
, ret
);
1148 /* see comments in should_cow_block() */
1149 root
->force_cow
= 1;
1152 btrfs_set_root_node(new_root_item
, tmp
);
1153 /* record when the snapshot was created in key.offset */
1154 key
.offset
= trans
->transid
;
1155 ret
= btrfs_insert_root(trans
, tree_root
, &key
, new_root_item
);
1156 btrfs_tree_unlock(tmp
);
1157 free_extent_buffer(tmp
);
1159 btrfs_abort_transaction(trans
, root
, ret
);
1164 * insert root back/forward references
1166 ret
= btrfs_add_root_ref(trans
, tree_root
, objectid
,
1167 parent_root
->root_key
.objectid
,
1168 btrfs_ino(parent_inode
), index
,
1169 dentry
->d_name
.name
, dentry
->d_name
.len
);
1171 btrfs_abort_transaction(trans
, root
, ret
);
1175 key
.offset
= (u64
)-1;
1176 pending
->snap
= btrfs_read_fs_root_no_name(root
->fs_info
, &key
);
1177 if (IS_ERR(pending
->snap
)) {
1178 ret
= PTR_ERR(pending
->snap
);
1179 btrfs_abort_transaction(trans
, root
, ret
);
1183 ret
= btrfs_reloc_post_snapshot(trans
, pending
);
1185 btrfs_abort_transaction(trans
, root
, ret
);
1189 ret
= btrfs_run_delayed_refs(trans
, root
, (unsigned long)-1);
1191 btrfs_abort_transaction(trans
, root
, ret
);
1195 ret
= btrfs_insert_dir_item(trans
, parent_root
,
1196 dentry
->d_name
.name
, dentry
->d_name
.len
,
1198 BTRFS_FT_DIR
, index
);
1199 /* We have check then name at the beginning, so it is impossible. */
1200 BUG_ON(ret
== -EEXIST
|| ret
== -EOVERFLOW
);
1202 btrfs_abort_transaction(trans
, root
, ret
);
1206 btrfs_i_size_write(parent_inode
, parent_inode
->i_size
+
1207 dentry
->d_name
.len
* 2);
1208 parent_inode
->i_mtime
= parent_inode
->i_ctime
= CURRENT_TIME
;
1209 ret
= btrfs_update_inode_fallback(trans
, parent_root
, parent_inode
);
1211 btrfs_abort_transaction(trans
, root
, ret
);
1214 trans
->block_rsv
= rsv
;
1216 kfree(new_root_item
);
1217 root_item_alloc_fail
:
1218 btrfs_free_path(path
);
1220 btrfs_block_rsv_release(root
, &pending
->block_rsv
, (u64
)-1);
1225 * create all the snapshots we've scheduled for creation
1227 static noinline
int create_pending_snapshots(struct btrfs_trans_handle
*trans
,
1228 struct btrfs_fs_info
*fs_info
)
1230 struct btrfs_pending_snapshot
*pending
;
1231 struct list_head
*head
= &trans
->transaction
->pending_snapshots
;
1233 list_for_each_entry(pending
, head
, list
)
1234 create_pending_snapshot(trans
, fs_info
, pending
);
1238 static void update_super_roots(struct btrfs_root
*root
)
1240 struct btrfs_root_item
*root_item
;
1241 struct btrfs_super_block
*super
;
1243 super
= root
->fs_info
->super_copy
;
1245 root_item
= &root
->fs_info
->chunk_root
->root_item
;
1246 super
->chunk_root
= root_item
->bytenr
;
1247 super
->chunk_root_generation
= root_item
->generation
;
1248 super
->chunk_root_level
= root_item
->level
;
1250 root_item
= &root
->fs_info
->tree_root
->root_item
;
1251 super
->root
= root_item
->bytenr
;
1252 super
->generation
= root_item
->generation
;
1253 super
->root_level
= root_item
->level
;
1254 if (btrfs_test_opt(root
, SPACE_CACHE
))
1255 super
->cache_generation
= root_item
->generation
;
1258 int btrfs_transaction_in_commit(struct btrfs_fs_info
*info
)
1261 spin_lock(&info
->trans_lock
);
1262 if (info
->running_transaction
)
1263 ret
= info
->running_transaction
->in_commit
;
1264 spin_unlock(&info
->trans_lock
);
1268 int btrfs_transaction_blocked(struct btrfs_fs_info
*info
)
1271 spin_lock(&info
->trans_lock
);
1272 if (info
->running_transaction
)
1273 ret
= info
->running_transaction
->blocked
;
1274 spin_unlock(&info
->trans_lock
);
1279 * wait for the current transaction commit to start and block subsequent
1282 static void wait_current_trans_commit_start(struct btrfs_root
*root
,
1283 struct btrfs_transaction
*trans
)
1285 wait_event(root
->fs_info
->transaction_blocked_wait
, trans
->in_commit
);
1289 * wait for the current transaction to start and then become unblocked.
1292 static void wait_current_trans_commit_start_and_unblock(struct btrfs_root
*root
,
1293 struct btrfs_transaction
*trans
)
1295 wait_event(root
->fs_info
->transaction_wait
,
1296 trans
->commit_done
|| (trans
->in_commit
&& !trans
->blocked
));
1300 * commit transactions asynchronously. once btrfs_commit_transaction_async
1301 * returns, any subsequent transaction will not be allowed to join.
1303 struct btrfs_async_commit
{
1304 struct btrfs_trans_handle
*newtrans
;
1305 struct btrfs_root
*root
;
1306 struct delayed_work work
;
1309 static void do_async_commit(struct work_struct
*work
)
1311 struct btrfs_async_commit
*ac
=
1312 container_of(work
, struct btrfs_async_commit
, work
.work
);
1315 * We've got freeze protection passed with the transaction.
1316 * Tell lockdep about it.
1318 if (ac
->newtrans
->type
< TRANS_JOIN_NOLOCK
)
1320 &ac
->root
->fs_info
->sb
->s_writers
.lock_map
[SB_FREEZE_FS
-1],
1323 current
->journal_info
= ac
->newtrans
;
1325 btrfs_commit_transaction(ac
->newtrans
, ac
->root
);
1329 int btrfs_commit_transaction_async(struct btrfs_trans_handle
*trans
,
1330 struct btrfs_root
*root
,
1331 int wait_for_unblock
)
1333 struct btrfs_async_commit
*ac
;
1334 struct btrfs_transaction
*cur_trans
;
1336 ac
= kmalloc(sizeof(*ac
), GFP_NOFS
);
1340 INIT_DELAYED_WORK(&ac
->work
, do_async_commit
);
1342 ac
->newtrans
= btrfs_join_transaction(root
);
1343 if (IS_ERR(ac
->newtrans
)) {
1344 int err
= PTR_ERR(ac
->newtrans
);
1349 /* take transaction reference */
1350 cur_trans
= trans
->transaction
;
1351 atomic_inc(&cur_trans
->use_count
);
1353 btrfs_end_transaction(trans
, root
);
1356 * Tell lockdep we've released the freeze rwsem, since the
1357 * async commit thread will be the one to unlock it.
1359 if (trans
->type
< TRANS_JOIN_NOLOCK
)
1361 &root
->fs_info
->sb
->s_writers
.lock_map
[SB_FREEZE_FS
-1],
1364 schedule_delayed_work(&ac
->work
, 0);
1366 /* wait for transaction to start and unblock */
1367 if (wait_for_unblock
)
1368 wait_current_trans_commit_start_and_unblock(root
, cur_trans
);
1370 wait_current_trans_commit_start(root
, cur_trans
);
1372 if (current
->journal_info
== trans
)
1373 current
->journal_info
= NULL
;
1375 put_transaction(cur_trans
);
1380 static void cleanup_transaction(struct btrfs_trans_handle
*trans
,
1381 struct btrfs_root
*root
, int err
)
1383 struct btrfs_transaction
*cur_trans
= trans
->transaction
;
1385 WARN_ON(trans
->use_count
> 1);
1387 btrfs_abort_transaction(trans
, root
, err
);
1389 spin_lock(&root
->fs_info
->trans_lock
);
1390 list_del_init(&cur_trans
->list
);
1391 if (cur_trans
== root
->fs_info
->running_transaction
) {
1392 root
->fs_info
->running_transaction
= NULL
;
1393 root
->fs_info
->trans_no_join
= 0;
1395 spin_unlock(&root
->fs_info
->trans_lock
);
1397 btrfs_cleanup_one_transaction(trans
->transaction
, root
);
1399 put_transaction(cur_trans
);
1400 put_transaction(cur_trans
);
1402 trace_btrfs_transaction_commit(root
);
1404 btrfs_scrub_continue(root
);
1406 if (current
->journal_info
== trans
)
1407 current
->journal_info
= NULL
;
1409 kmem_cache_free(btrfs_trans_handle_cachep
, trans
);
1412 static int btrfs_flush_all_pending_stuffs(struct btrfs_trans_handle
*trans
,
1413 struct btrfs_root
*root
)
1415 int flush_on_commit
= btrfs_test_opt(root
, FLUSHONCOMMIT
);
1416 int snap_pending
= 0;
1419 if (!flush_on_commit
) {
1420 spin_lock(&root
->fs_info
->trans_lock
);
1421 if (!list_empty(&trans
->transaction
->pending_snapshots
))
1423 spin_unlock(&root
->fs_info
->trans_lock
);
1426 if (flush_on_commit
|| snap_pending
) {
1427 btrfs_start_delalloc_inodes(root
, 1);
1428 btrfs_wait_ordered_extents(root
, 1);
1431 ret
= btrfs_run_delayed_items(trans
, root
);
1436 * running the delayed items may have added new refs. account
1437 * them now so that they hinder processing of more delayed refs
1438 * as little as possible.
1440 btrfs_delayed_refs_qgroup_accounting(trans
, root
->fs_info
);
1443 * rename don't use btrfs_join_transaction, so, once we
1444 * set the transaction to blocked above, we aren't going
1445 * to get any new ordered operations. We can safely run
1446 * it here and no for sure that nothing new will be added
1449 btrfs_run_ordered_operations(root
, 1);
1455 * btrfs_transaction state sequence:
1456 * in_commit = 0, blocked = 0 (initial)
1457 * in_commit = 1, blocked = 1
1461 int btrfs_commit_transaction(struct btrfs_trans_handle
*trans
,
1462 struct btrfs_root
*root
)
1464 unsigned long joined
= 0;
1465 struct btrfs_transaction
*cur_trans
= trans
->transaction
;
1466 struct btrfs_transaction
*prev_trans
= NULL
;
1469 int should_grow
= 0;
1470 unsigned long now
= get_seconds();
1472 ret
= btrfs_run_ordered_operations(root
, 0);
1474 btrfs_abort_transaction(trans
, root
, ret
);
1475 goto cleanup_transaction
;
1478 if (cur_trans
->aborted
) {
1479 ret
= cur_trans
->aborted
;
1480 goto cleanup_transaction
;
1483 /* make a pass through all the delayed refs we have so far
1484 * any runnings procs may add more while we are here
1486 ret
= btrfs_run_delayed_refs(trans
, root
, 0);
1488 goto cleanup_transaction
;
1490 btrfs_trans_release_metadata(trans
, root
);
1491 trans
->block_rsv
= NULL
;
1493 cur_trans
= trans
->transaction
;
1496 * set the flushing flag so procs in this transaction have to
1497 * start sending their work down.
1499 cur_trans
->delayed_refs
.flushing
= 1;
1501 if (!list_empty(&trans
->new_bgs
))
1502 btrfs_create_pending_block_groups(trans
, root
);
1504 ret
= btrfs_run_delayed_refs(trans
, root
, 0);
1506 goto cleanup_transaction
;
1508 spin_lock(&cur_trans
->commit_lock
);
1509 if (cur_trans
->in_commit
) {
1510 spin_unlock(&cur_trans
->commit_lock
);
1511 atomic_inc(&cur_trans
->use_count
);
1512 ret
= btrfs_end_transaction(trans
, root
);
1514 wait_for_commit(root
, cur_trans
);
1516 put_transaction(cur_trans
);
1521 trans
->transaction
->in_commit
= 1;
1522 trans
->transaction
->blocked
= 1;
1523 spin_unlock(&cur_trans
->commit_lock
);
1524 wake_up(&root
->fs_info
->transaction_blocked_wait
);
1526 spin_lock(&root
->fs_info
->trans_lock
);
1527 if (cur_trans
->list
.prev
!= &root
->fs_info
->trans_list
) {
1528 prev_trans
= list_entry(cur_trans
->list
.prev
,
1529 struct btrfs_transaction
, list
);
1530 if (!prev_trans
->commit_done
) {
1531 atomic_inc(&prev_trans
->use_count
);
1532 spin_unlock(&root
->fs_info
->trans_lock
);
1534 wait_for_commit(root
, prev_trans
);
1536 put_transaction(prev_trans
);
1538 spin_unlock(&root
->fs_info
->trans_lock
);
1541 spin_unlock(&root
->fs_info
->trans_lock
);
1544 if (!btrfs_test_opt(root
, SSD
) &&
1545 (now
< cur_trans
->start_time
|| now
- cur_trans
->start_time
< 1))
1549 joined
= cur_trans
->num_joined
;
1551 WARN_ON(cur_trans
!= trans
->transaction
);
1553 ret
= btrfs_flush_all_pending_stuffs(trans
, root
);
1555 goto cleanup_transaction
;
1557 prepare_to_wait(&cur_trans
->writer_wait
, &wait
,
1558 TASK_UNINTERRUPTIBLE
);
1560 if (atomic_read(&cur_trans
->num_writers
) > 1)
1561 schedule_timeout(MAX_SCHEDULE_TIMEOUT
);
1562 else if (should_grow
)
1563 schedule_timeout(1);
1565 finish_wait(&cur_trans
->writer_wait
, &wait
);
1566 } while (atomic_read(&cur_trans
->num_writers
) > 1 ||
1567 (should_grow
&& cur_trans
->num_joined
!= joined
));
1569 ret
= btrfs_flush_all_pending_stuffs(trans
, root
);
1571 goto cleanup_transaction
;
1574 * Ok now we need to make sure to block out any other joins while we
1575 * commit the transaction. We could have started a join before setting
1576 * no_join so make sure to wait for num_writers to == 1 again.
1578 spin_lock(&root
->fs_info
->trans_lock
);
1579 root
->fs_info
->trans_no_join
= 1;
1580 spin_unlock(&root
->fs_info
->trans_lock
);
1581 wait_event(cur_trans
->writer_wait
,
1582 atomic_read(&cur_trans
->num_writers
) == 1);
1585 * the reloc mutex makes sure that we stop
1586 * the balancing code from coming in and moving
1587 * extents around in the middle of the commit
1589 mutex_lock(&root
->fs_info
->reloc_mutex
);
1592 * We needn't worry about the delayed items because we will
1593 * deal with them in create_pending_snapshot(), which is the
1594 * core function of the snapshot creation.
1596 ret
= create_pending_snapshots(trans
, root
->fs_info
);
1598 mutex_unlock(&root
->fs_info
->reloc_mutex
);
1599 goto cleanup_transaction
;
1603 * We insert the dir indexes of the snapshots and update the inode
1604 * of the snapshots' parents after the snapshot creation, so there
1605 * are some delayed items which are not dealt with. Now deal with
1608 * We needn't worry that this operation will corrupt the snapshots,
1609 * because all the tree which are snapshoted will be forced to COW
1610 * the nodes and leaves.
1612 ret
= btrfs_run_delayed_items(trans
, root
);
1614 mutex_unlock(&root
->fs_info
->reloc_mutex
);
1615 goto cleanup_transaction
;
1618 ret
= btrfs_run_delayed_refs(trans
, root
, (unsigned long)-1);
1620 mutex_unlock(&root
->fs_info
->reloc_mutex
);
1621 goto cleanup_transaction
;
1625 * make sure none of the code above managed to slip in a
1628 btrfs_assert_delayed_root_empty(root
);
1630 WARN_ON(cur_trans
!= trans
->transaction
);
1632 btrfs_scrub_pause(root
);
1633 /* btrfs_commit_tree_roots is responsible for getting the
1634 * various roots consistent with each other. Every pointer
1635 * in the tree of tree roots has to point to the most up to date
1636 * root for every subvolume and other tree. So, we have to keep
1637 * the tree logging code from jumping in and changing any
1640 * At this point in the commit, there can't be any tree-log
1641 * writers, but a little lower down we drop the trans mutex
1642 * and let new people in. By holding the tree_log_mutex
1643 * from now until after the super is written, we avoid races
1644 * with the tree-log code.
1646 mutex_lock(&root
->fs_info
->tree_log_mutex
);
1648 ret
= commit_fs_roots(trans
, root
);
1650 mutex_unlock(&root
->fs_info
->tree_log_mutex
);
1651 mutex_unlock(&root
->fs_info
->reloc_mutex
);
1652 goto cleanup_transaction
;
1655 /* commit_fs_roots gets rid of all the tree log roots, it is now
1656 * safe to free the root of tree log roots
1658 btrfs_free_log_root_tree(trans
, root
->fs_info
);
1660 ret
= commit_cowonly_roots(trans
, root
);
1662 mutex_unlock(&root
->fs_info
->tree_log_mutex
);
1663 mutex_unlock(&root
->fs_info
->reloc_mutex
);
1664 goto cleanup_transaction
;
1667 btrfs_prepare_extent_commit(trans
, root
);
1669 cur_trans
= root
->fs_info
->running_transaction
;
1671 btrfs_set_root_node(&root
->fs_info
->tree_root
->root_item
,
1672 root
->fs_info
->tree_root
->node
);
1673 switch_commit_root(root
->fs_info
->tree_root
);
1675 btrfs_set_root_node(&root
->fs_info
->chunk_root
->root_item
,
1676 root
->fs_info
->chunk_root
->node
);
1677 switch_commit_root(root
->fs_info
->chunk_root
);
1679 assert_qgroups_uptodate(trans
);
1680 update_super_roots(root
);
1682 if (!root
->fs_info
->log_root_recovering
) {
1683 btrfs_set_super_log_root(root
->fs_info
->super_copy
, 0);
1684 btrfs_set_super_log_root_level(root
->fs_info
->super_copy
, 0);
1687 memcpy(root
->fs_info
->super_for_commit
, root
->fs_info
->super_copy
,
1688 sizeof(*root
->fs_info
->super_copy
));
1690 trans
->transaction
->blocked
= 0;
1691 spin_lock(&root
->fs_info
->trans_lock
);
1692 root
->fs_info
->running_transaction
= NULL
;
1693 root
->fs_info
->trans_no_join
= 0;
1694 spin_unlock(&root
->fs_info
->trans_lock
);
1695 mutex_unlock(&root
->fs_info
->reloc_mutex
);
1697 wake_up(&root
->fs_info
->transaction_wait
);
1699 ret
= btrfs_write_and_wait_transaction(trans
, root
);
1701 btrfs_error(root
->fs_info
, ret
,
1702 "Error while writing out transaction.");
1703 mutex_unlock(&root
->fs_info
->tree_log_mutex
);
1704 goto cleanup_transaction
;
1707 ret
= write_ctree_super(trans
, root
, 0);
1709 mutex_unlock(&root
->fs_info
->tree_log_mutex
);
1710 goto cleanup_transaction
;
1714 * the super is written, we can safely allow the tree-loggers
1715 * to go about their business
1717 mutex_unlock(&root
->fs_info
->tree_log_mutex
);
1719 btrfs_finish_extent_commit(trans
, root
);
1721 cur_trans
->commit_done
= 1;
1723 root
->fs_info
->last_trans_committed
= cur_trans
->transid
;
1725 wake_up(&cur_trans
->commit_wait
);
1727 spin_lock(&root
->fs_info
->trans_lock
);
1728 list_del_init(&cur_trans
->list
);
1729 spin_unlock(&root
->fs_info
->trans_lock
);
1731 put_transaction(cur_trans
);
1732 put_transaction(cur_trans
);
1734 if (trans
->type
< TRANS_JOIN_NOLOCK
)
1735 sb_end_intwrite(root
->fs_info
->sb
);
1737 trace_btrfs_transaction_commit(root
);
1739 btrfs_scrub_continue(root
);
1741 if (current
->journal_info
== trans
)
1742 current
->journal_info
= NULL
;
1744 kmem_cache_free(btrfs_trans_handle_cachep
, trans
);
1746 if (current
!= root
->fs_info
->transaction_kthread
)
1747 btrfs_run_delayed_iputs(root
);
1751 cleanup_transaction
:
1752 btrfs_trans_release_metadata(trans
, root
);
1753 trans
->block_rsv
= NULL
;
1754 btrfs_printk(root
->fs_info
, "Skipping commit of aborted transaction.\n");
1756 if (current
->journal_info
== trans
)
1757 current
->journal_info
= NULL
;
1758 cleanup_transaction(trans
, root
, ret
);
1764 * interface function to delete all the snapshots we have scheduled for deletion
1766 int btrfs_clean_old_snapshots(struct btrfs_root
*root
)
1769 struct btrfs_fs_info
*fs_info
= root
->fs_info
;
1771 spin_lock(&fs_info
->trans_lock
);
1772 list_splice_init(&fs_info
->dead_roots
, &list
);
1773 spin_unlock(&fs_info
->trans_lock
);
1775 while (!list_empty(&list
)) {
1778 root
= list_entry(list
.next
, struct btrfs_root
, root_list
);
1779 list_del(&root
->root_list
);
1781 btrfs_kill_all_delayed_nodes(root
);
1783 if (btrfs_header_backref_rev(root
->node
) <
1784 BTRFS_MIXED_BACKREF_REV
)
1785 ret
= btrfs_drop_snapshot(root
, NULL
, 0, 0);
1787 ret
=btrfs_drop_snapshot(root
, NULL
, 1, 0);