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 static noinline
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 memset(transaction
, 0, sizeof(*transaction
));
39 kmem_cache_free(btrfs_transaction_cachep
, transaction
);
43 static noinline
void switch_commit_root(struct btrfs_root
*root
)
45 free_extent_buffer(root
->commit_root
);
46 root
->commit_root
= btrfs_root_node(root
);
50 * either allocate a new transaction or hop into the existing one
52 static noinline
int join_transaction(struct btrfs_root
*root
)
54 struct btrfs_transaction
*cur_trans
;
55 cur_trans
= root
->fs_info
->running_transaction
;
57 cur_trans
= kmem_cache_alloc(btrfs_transaction_cachep
,
61 root
->fs_info
->generation
++;
62 atomic_set(&cur_trans
->num_writers
, 1);
63 cur_trans
->num_joined
= 0;
64 cur_trans
->transid
= root
->fs_info
->generation
;
65 init_waitqueue_head(&cur_trans
->writer_wait
);
66 init_waitqueue_head(&cur_trans
->commit_wait
);
67 cur_trans
->in_commit
= 0;
68 cur_trans
->blocked
= 0;
69 atomic_set(&cur_trans
->use_count
, 1);
70 cur_trans
->commit_done
= 0;
71 cur_trans
->start_time
= get_seconds();
73 cur_trans
->delayed_refs
.root
= RB_ROOT
;
74 cur_trans
->delayed_refs
.num_entries
= 0;
75 cur_trans
->delayed_refs
.num_heads_ready
= 0;
76 cur_trans
->delayed_refs
.num_heads
= 0;
77 cur_trans
->delayed_refs
.flushing
= 0;
78 cur_trans
->delayed_refs
.run_delayed_start
= 0;
79 spin_lock_init(&cur_trans
->delayed_refs
.lock
);
81 INIT_LIST_HEAD(&cur_trans
->pending_snapshots
);
82 list_add_tail(&cur_trans
->list
, &root
->fs_info
->trans_list
);
83 extent_io_tree_init(&cur_trans
->dirty_pages
,
84 root
->fs_info
->btree_inode
->i_mapping
);
85 spin_lock(&root
->fs_info
->new_trans_lock
);
86 root
->fs_info
->running_transaction
= cur_trans
;
87 spin_unlock(&root
->fs_info
->new_trans_lock
);
89 atomic_inc(&cur_trans
->num_writers
);
90 cur_trans
->num_joined
++;
97 * this does all the record keeping required to make sure that a reference
98 * counted root is properly recorded in a given transaction. This is required
99 * to make sure the old root from before we joined the transaction is deleted
100 * when the transaction commits
102 static noinline
int record_root_in_trans(struct btrfs_trans_handle
*trans
,
103 struct btrfs_root
*root
)
105 if (root
->ref_cows
&& root
->last_trans
< trans
->transid
) {
106 WARN_ON(root
== root
->fs_info
->extent_root
);
107 WARN_ON(root
->commit_root
!= root
->node
);
109 radix_tree_tag_set(&root
->fs_info
->fs_roots_radix
,
110 (unsigned long)root
->root_key
.objectid
,
111 BTRFS_ROOT_TRANS_TAG
);
112 root
->last_trans
= trans
->transid
;
113 btrfs_init_reloc_root(trans
, root
);
118 int btrfs_record_root_in_trans(struct btrfs_trans_handle
*trans
,
119 struct btrfs_root
*root
)
124 mutex_lock(&root
->fs_info
->trans_mutex
);
125 if (root
->last_trans
== trans
->transid
) {
126 mutex_unlock(&root
->fs_info
->trans_mutex
);
130 record_root_in_trans(trans
, root
);
131 mutex_unlock(&root
->fs_info
->trans_mutex
);
135 /* wait for commit against the current transaction to become unblocked
136 * when this is done, it is safe to start a new transaction, but the current
137 * transaction might not be fully on disk.
139 static void wait_current_trans(struct btrfs_root
*root
)
141 struct btrfs_transaction
*cur_trans
;
143 cur_trans
= root
->fs_info
->running_transaction
;
144 if (cur_trans
&& cur_trans
->blocked
) {
146 atomic_inc(&cur_trans
->use_count
);
148 prepare_to_wait(&root
->fs_info
->transaction_wait
, &wait
,
149 TASK_UNINTERRUPTIBLE
);
150 if (!cur_trans
->blocked
)
152 mutex_unlock(&root
->fs_info
->trans_mutex
);
154 mutex_lock(&root
->fs_info
->trans_mutex
);
156 finish_wait(&root
->fs_info
->transaction_wait
, &wait
);
157 put_transaction(cur_trans
);
161 enum btrfs_trans_type
{
168 static int may_wait_transaction(struct btrfs_root
*root
, int type
)
170 if (!root
->fs_info
->log_root_recovering
&&
171 ((type
== TRANS_START
&& !root
->fs_info
->open_ioctl_trans
) ||
172 type
== TRANS_USERSPACE
))
177 static struct btrfs_trans_handle
*start_transaction(struct btrfs_root
*root
,
178 u64 num_items
, int type
)
180 struct btrfs_trans_handle
*h
;
181 struct btrfs_transaction
*cur_trans
;
185 if (root
->fs_info
->fs_state
& BTRFS_SUPER_FLAG_ERROR
)
186 return ERR_PTR(-EROFS
);
188 h
= kmem_cache_alloc(btrfs_trans_handle_cachep
, GFP_NOFS
);
190 return ERR_PTR(-ENOMEM
);
192 if (type
!= TRANS_JOIN_NOLOCK
)
193 mutex_lock(&root
->fs_info
->trans_mutex
);
194 if (may_wait_transaction(root
, type
))
195 wait_current_trans(root
);
197 ret
= join_transaction(root
);
199 kmem_cache_free(btrfs_trans_handle_cachep
, h
);
200 if (type
!= TRANS_JOIN_NOLOCK
)
201 mutex_unlock(&root
->fs_info
->trans_mutex
);
205 cur_trans
= root
->fs_info
->running_transaction
;
206 atomic_inc(&cur_trans
->use_count
);
207 if (type
!= TRANS_JOIN_NOLOCK
)
208 mutex_unlock(&root
->fs_info
->trans_mutex
);
210 h
->transid
= cur_trans
->transid
;
211 h
->transaction
= cur_trans
;
214 h
->bytes_reserved
= 0;
215 h
->delayed_ref_updates
= 0;
219 if (cur_trans
->blocked
&& may_wait_transaction(root
, type
)) {
220 btrfs_commit_transaction(h
, root
);
225 ret
= btrfs_trans_reserve_metadata(h
, root
, num_items
);
226 if (ret
== -EAGAIN
&& !retries
) {
228 btrfs_commit_transaction(h
, root
);
230 } else if (ret
== -EAGAIN
) {
232 * We have already retried and got EAGAIN, so really we
233 * don't have space, so set ret to -ENOSPC.
239 btrfs_end_transaction(h
, root
);
244 if (type
!= TRANS_JOIN_NOLOCK
)
245 mutex_lock(&root
->fs_info
->trans_mutex
);
246 record_root_in_trans(h
, root
);
247 if (type
!= TRANS_JOIN_NOLOCK
)
248 mutex_unlock(&root
->fs_info
->trans_mutex
);
250 if (!current
->journal_info
&& type
!= TRANS_USERSPACE
)
251 current
->journal_info
= h
;
255 struct btrfs_trans_handle
*btrfs_start_transaction(struct btrfs_root
*root
,
258 return start_transaction(root
, num_items
, TRANS_START
);
260 struct btrfs_trans_handle
*btrfs_join_transaction(struct btrfs_root
*root
,
263 return start_transaction(root
, 0, TRANS_JOIN
);
266 struct btrfs_trans_handle
*btrfs_join_transaction_nolock(struct btrfs_root
*root
,
269 return start_transaction(root
, 0, TRANS_JOIN_NOLOCK
);
272 struct btrfs_trans_handle
*btrfs_start_ioctl_transaction(struct btrfs_root
*r
,
275 return start_transaction(r
, 0, TRANS_USERSPACE
);
278 /* wait for a transaction commit to be fully complete */
279 static noinline
int wait_for_commit(struct btrfs_root
*root
,
280 struct btrfs_transaction
*commit
)
283 mutex_lock(&root
->fs_info
->trans_mutex
);
284 while (!commit
->commit_done
) {
285 prepare_to_wait(&commit
->commit_wait
, &wait
,
286 TASK_UNINTERRUPTIBLE
);
287 if (commit
->commit_done
)
289 mutex_unlock(&root
->fs_info
->trans_mutex
);
291 mutex_lock(&root
->fs_info
->trans_mutex
);
293 mutex_unlock(&root
->fs_info
->trans_mutex
);
294 finish_wait(&commit
->commit_wait
, &wait
);
298 int btrfs_wait_for_commit(struct btrfs_root
*root
, u64 transid
)
300 struct btrfs_transaction
*cur_trans
= NULL
, *t
;
303 mutex_lock(&root
->fs_info
->trans_mutex
);
307 if (transid
<= root
->fs_info
->last_trans_committed
)
310 /* find specified transaction */
311 list_for_each_entry(t
, &root
->fs_info
->trans_list
, list
) {
312 if (t
->transid
== transid
) {
316 if (t
->transid
> transid
)
321 goto out_unlock
; /* bad transid */
323 /* find newest transaction that is committing | committed */
324 list_for_each_entry_reverse(t
, &root
->fs_info
->trans_list
,
334 goto out_unlock
; /* nothing committing|committed */
337 atomic_inc(&cur_trans
->use_count
);
338 mutex_unlock(&root
->fs_info
->trans_mutex
);
340 wait_for_commit(root
, cur_trans
);
342 mutex_lock(&root
->fs_info
->trans_mutex
);
343 put_transaction(cur_trans
);
346 mutex_unlock(&root
->fs_info
->trans_mutex
);
350 void btrfs_throttle(struct btrfs_root
*root
)
352 mutex_lock(&root
->fs_info
->trans_mutex
);
353 if (!root
->fs_info
->open_ioctl_trans
)
354 wait_current_trans(root
);
355 mutex_unlock(&root
->fs_info
->trans_mutex
);
358 static int should_end_transaction(struct btrfs_trans_handle
*trans
,
359 struct btrfs_root
*root
)
362 ret
= btrfs_block_rsv_check(trans
, root
,
363 &root
->fs_info
->global_block_rsv
, 0, 5);
367 int btrfs_should_end_transaction(struct btrfs_trans_handle
*trans
,
368 struct btrfs_root
*root
)
370 struct btrfs_transaction
*cur_trans
= trans
->transaction
;
373 if (cur_trans
->blocked
|| cur_trans
->delayed_refs
.flushing
)
376 updates
= trans
->delayed_ref_updates
;
377 trans
->delayed_ref_updates
= 0;
379 btrfs_run_delayed_refs(trans
, root
, updates
);
381 return should_end_transaction(trans
, root
);
384 static int __btrfs_end_transaction(struct btrfs_trans_handle
*trans
,
385 struct btrfs_root
*root
, int throttle
, int lock
)
387 struct btrfs_transaction
*cur_trans
= trans
->transaction
;
388 struct btrfs_fs_info
*info
= root
->fs_info
;
392 unsigned long cur
= trans
->delayed_ref_updates
;
393 trans
->delayed_ref_updates
= 0;
395 trans
->transaction
->delayed_refs
.num_heads_ready
> 64) {
396 trans
->delayed_ref_updates
= 0;
399 * do a full flush if the transaction is trying
402 if (trans
->transaction
->delayed_refs
.flushing
)
404 btrfs_run_delayed_refs(trans
, root
, cur
);
411 btrfs_trans_release_metadata(trans
, root
);
413 if (lock
&& !root
->fs_info
->open_ioctl_trans
&&
414 should_end_transaction(trans
, root
))
415 trans
->transaction
->blocked
= 1;
417 if (lock
&& cur_trans
->blocked
&& !cur_trans
->in_commit
) {
419 return btrfs_commit_transaction(trans
, root
);
421 wake_up_process(info
->transaction_kthread
);
424 WARN_ON(cur_trans
!= info
->running_transaction
);
425 WARN_ON(atomic_read(&cur_trans
->num_writers
) < 1);
426 atomic_dec(&cur_trans
->num_writers
);
429 if (waitqueue_active(&cur_trans
->writer_wait
))
430 wake_up(&cur_trans
->writer_wait
);
431 put_transaction(cur_trans
);
433 if (current
->journal_info
== trans
)
434 current
->journal_info
= NULL
;
435 memset(trans
, 0, sizeof(*trans
));
436 kmem_cache_free(btrfs_trans_handle_cachep
, trans
);
439 btrfs_run_delayed_iputs(root
);
444 int btrfs_end_transaction(struct btrfs_trans_handle
*trans
,
445 struct btrfs_root
*root
)
449 ret
= __btrfs_end_transaction(trans
, root
, 0, 1);
455 int btrfs_end_transaction_throttle(struct btrfs_trans_handle
*trans
,
456 struct btrfs_root
*root
)
460 ret
= __btrfs_end_transaction(trans
, root
, 1, 1);
466 int btrfs_end_transaction_nolock(struct btrfs_trans_handle
*trans
,
467 struct btrfs_root
*root
)
471 ret
= __btrfs_end_transaction(trans
, root
, 0, 0);
477 int btrfs_end_transaction_dmeta(struct btrfs_trans_handle
*trans
,
478 struct btrfs_root
*root
)
480 return __btrfs_end_transaction(trans
, root
, 1, 1);
484 * when btree blocks are allocated, they have some corresponding bits set for
485 * them in one of two extent_io trees. This is used to make sure all of
486 * those extents are sent to disk but does not wait on them
488 int btrfs_write_marked_extents(struct btrfs_root
*root
,
489 struct extent_io_tree
*dirty_pages
, int mark
)
495 struct inode
*btree_inode
= root
->fs_info
->btree_inode
;
501 ret
= find_first_extent_bit(dirty_pages
, start
, &start
, &end
,
505 while (start
<= end
) {
508 index
= start
>> PAGE_CACHE_SHIFT
;
509 start
= (u64
)(index
+ 1) << PAGE_CACHE_SHIFT
;
510 page
= find_get_page(btree_inode
->i_mapping
, index
);
514 btree_lock_page_hook(page
);
515 if (!page
->mapping
) {
517 page_cache_release(page
);
521 if (PageWriteback(page
)) {
523 wait_on_page_writeback(page
);
526 page_cache_release(page
);
530 err
= write_one_page(page
, 0);
533 page_cache_release(page
);
542 * when btree blocks are allocated, they have some corresponding bits set for
543 * them in one of two extent_io trees. This is used to make sure all of
544 * those extents are on disk for transaction or log commit. We wait
545 * on all the pages and clear them from the dirty pages state tree
547 int btrfs_wait_marked_extents(struct btrfs_root
*root
,
548 struct extent_io_tree
*dirty_pages
, int mark
)
554 struct inode
*btree_inode
= root
->fs_info
->btree_inode
;
560 ret
= find_first_extent_bit(dirty_pages
, start
, &start
, &end
,
565 clear_extent_bits(dirty_pages
, start
, end
, mark
, GFP_NOFS
);
566 while (start
<= end
) {
567 index
= start
>> PAGE_CACHE_SHIFT
;
568 start
= (u64
)(index
+ 1) << PAGE_CACHE_SHIFT
;
569 page
= find_get_page(btree_inode
->i_mapping
, index
);
572 if (PageDirty(page
)) {
573 btree_lock_page_hook(page
);
574 wait_on_page_writeback(page
);
575 err
= write_one_page(page
, 0);
579 wait_on_page_writeback(page
);
580 page_cache_release(page
);
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 on disk for transaction or log commit
594 int btrfs_write_and_wait_marked_extents(struct btrfs_root
*root
,
595 struct extent_io_tree
*dirty_pages
, int mark
)
600 ret
= btrfs_write_marked_extents(root
, dirty_pages
, mark
);
601 ret2
= btrfs_wait_marked_extents(root
, dirty_pages
, mark
);
605 int btrfs_write_and_wait_transaction(struct btrfs_trans_handle
*trans
,
606 struct btrfs_root
*root
)
608 if (!trans
|| !trans
->transaction
) {
609 struct inode
*btree_inode
;
610 btree_inode
= root
->fs_info
->btree_inode
;
611 return filemap_write_and_wait(btree_inode
->i_mapping
);
613 return btrfs_write_and_wait_marked_extents(root
,
614 &trans
->transaction
->dirty_pages
,
619 * this is used to update the root pointer in the tree of tree roots.
621 * But, in the case of the extent allocation tree, updating the root
622 * pointer may allocate blocks which may change the root of the extent
625 * So, this loops and repeats and makes sure the cowonly root didn't
626 * change while the root pointer was being updated in the metadata.
628 static int update_cowonly_root(struct btrfs_trans_handle
*trans
,
629 struct btrfs_root
*root
)
634 struct btrfs_root
*tree_root
= root
->fs_info
->tree_root
;
636 old_root_used
= btrfs_root_used(&root
->root_item
);
637 btrfs_write_dirty_block_groups(trans
, root
);
640 old_root_bytenr
= btrfs_root_bytenr(&root
->root_item
);
641 if (old_root_bytenr
== root
->node
->start
&&
642 old_root_used
== btrfs_root_used(&root
->root_item
))
645 btrfs_set_root_node(&root
->root_item
, root
->node
);
646 ret
= btrfs_update_root(trans
, tree_root
,
651 old_root_used
= btrfs_root_used(&root
->root_item
);
652 ret
= btrfs_write_dirty_block_groups(trans
, root
);
656 if (root
!= root
->fs_info
->extent_root
)
657 switch_commit_root(root
);
663 * update all the cowonly tree roots on disk
665 static noinline
int commit_cowonly_roots(struct btrfs_trans_handle
*trans
,
666 struct btrfs_root
*root
)
668 struct btrfs_fs_info
*fs_info
= root
->fs_info
;
669 struct list_head
*next
;
670 struct extent_buffer
*eb
;
673 ret
= btrfs_run_delayed_refs(trans
, root
, (unsigned long)-1);
676 eb
= btrfs_lock_root_node(fs_info
->tree_root
);
677 btrfs_cow_block(trans
, fs_info
->tree_root
, eb
, NULL
, 0, &eb
);
678 btrfs_tree_unlock(eb
);
679 free_extent_buffer(eb
);
681 ret
= btrfs_run_delayed_refs(trans
, root
, (unsigned long)-1);
684 while (!list_empty(&fs_info
->dirty_cowonly_roots
)) {
685 next
= fs_info
->dirty_cowonly_roots
.next
;
687 root
= list_entry(next
, struct btrfs_root
, dirty_list
);
689 update_cowonly_root(trans
, root
);
692 down_write(&fs_info
->extent_commit_sem
);
693 switch_commit_root(fs_info
->extent_root
);
694 up_write(&fs_info
->extent_commit_sem
);
700 * dead roots are old snapshots that need to be deleted. This allocates
701 * a dirty root struct and adds it into the list of dead roots that need to
704 int btrfs_add_dead_root(struct btrfs_root
*root
)
706 mutex_lock(&root
->fs_info
->trans_mutex
);
707 list_add(&root
->root_list
, &root
->fs_info
->dead_roots
);
708 mutex_unlock(&root
->fs_info
->trans_mutex
);
713 * update all the cowonly tree roots on disk
715 static noinline
int commit_fs_roots(struct btrfs_trans_handle
*trans
,
716 struct btrfs_root
*root
)
718 struct btrfs_root
*gang
[8];
719 struct btrfs_fs_info
*fs_info
= root
->fs_info
;
725 ret
= radix_tree_gang_lookup_tag(&fs_info
->fs_roots_radix
,
728 BTRFS_ROOT_TRANS_TAG
);
731 for (i
= 0; i
< ret
; i
++) {
733 radix_tree_tag_clear(&fs_info
->fs_roots_radix
,
734 (unsigned long)root
->root_key
.objectid
,
735 BTRFS_ROOT_TRANS_TAG
);
737 btrfs_free_log(trans
, root
);
738 btrfs_update_reloc_root(trans
, root
);
739 btrfs_orphan_commit_root(trans
, root
);
741 btrfs_save_ino_cache(root
, trans
);
743 if (root
->commit_root
!= root
->node
) {
744 mutex_lock(&root
->fs_commit_mutex
);
745 switch_commit_root(root
);
746 btrfs_unpin_free_ino(root
);
747 mutex_unlock(&root
->fs_commit_mutex
);
749 btrfs_set_root_node(&root
->root_item
,
753 err
= btrfs_update_root(trans
, fs_info
->tree_root
,
764 * defrag a given btree. If cacheonly == 1, this won't read from the disk,
765 * otherwise every leaf in the btree is read and defragged.
767 int btrfs_defrag_root(struct btrfs_root
*root
, int cacheonly
)
769 struct btrfs_fs_info
*info
= root
->fs_info
;
770 struct btrfs_trans_handle
*trans
;
774 if (xchg(&root
->defrag_running
, 1))
778 trans
= btrfs_start_transaction(root
, 0);
780 return PTR_ERR(trans
);
782 ret
= btrfs_defrag_leaves(trans
, root
, cacheonly
);
784 nr
= trans
->blocks_used
;
785 btrfs_end_transaction(trans
, root
);
786 btrfs_btree_balance_dirty(info
->tree_root
, nr
);
789 if (root
->fs_info
->closing
|| ret
!= -EAGAIN
)
792 root
->defrag_running
= 0;
797 * new snapshots need to be created at a very specific time in the
798 * transaction commit. This does the actual creation
800 static noinline
int create_pending_snapshot(struct btrfs_trans_handle
*trans
,
801 struct btrfs_fs_info
*fs_info
,
802 struct btrfs_pending_snapshot
*pending
)
804 struct btrfs_key key
;
805 struct btrfs_root_item
*new_root_item
;
806 struct btrfs_root
*tree_root
= fs_info
->tree_root
;
807 struct btrfs_root
*root
= pending
->root
;
808 struct btrfs_root
*parent_root
;
809 struct inode
*parent_inode
;
810 struct dentry
*parent
;
811 struct dentry
*dentry
;
812 struct extent_buffer
*tmp
;
813 struct extent_buffer
*old
;
820 new_root_item
= kmalloc(sizeof(*new_root_item
), GFP_NOFS
);
821 if (!new_root_item
) {
822 pending
->error
= -ENOMEM
;
826 ret
= btrfs_find_free_objectid(tree_root
, &objectid
);
828 pending
->error
= ret
;
832 btrfs_reloc_pre_snapshot(trans
, pending
, &to_reserve
);
833 btrfs_orphan_pre_snapshot(trans
, pending
, &to_reserve
);
835 if (to_reserve
> 0) {
836 ret
= btrfs_block_rsv_add(trans
, root
, &pending
->block_rsv
,
839 pending
->error
= ret
;
844 key
.objectid
= objectid
;
845 key
.offset
= (u64
)-1;
846 key
.type
= BTRFS_ROOT_ITEM_KEY
;
848 trans
->block_rsv
= &pending
->block_rsv
;
850 dentry
= pending
->dentry
;
851 parent
= dget_parent(dentry
);
852 parent_inode
= parent
->d_inode
;
853 parent_root
= BTRFS_I(parent_inode
)->root
;
854 record_root_in_trans(trans
, parent_root
);
857 * insert the directory item
859 ret
= btrfs_set_inode_index(parent_inode
, &index
);
861 ret
= btrfs_insert_dir_item(trans
, parent_root
,
862 dentry
->d_name
.name
, dentry
->d_name
.len
,
864 BTRFS_FT_DIR
, index
);
867 btrfs_i_size_write(parent_inode
, parent_inode
->i_size
+
868 dentry
->d_name
.len
* 2);
869 ret
= btrfs_update_inode(trans
, parent_root
, parent_inode
);
872 record_root_in_trans(trans
, root
);
873 btrfs_set_root_last_snapshot(&root
->root_item
, trans
->transid
);
874 memcpy(new_root_item
, &root
->root_item
, sizeof(*new_root_item
));
875 btrfs_check_and_init_root_item(new_root_item
);
877 root_flags
= btrfs_root_flags(new_root_item
);
878 if (pending
->readonly
)
879 root_flags
|= BTRFS_ROOT_SUBVOL_RDONLY
;
881 root_flags
&= ~BTRFS_ROOT_SUBVOL_RDONLY
;
882 btrfs_set_root_flags(new_root_item
, root_flags
);
884 old
= btrfs_lock_root_node(root
);
885 btrfs_cow_block(trans
, root
, old
, NULL
, 0, &old
);
886 btrfs_set_lock_blocking(old
);
888 btrfs_copy_root(trans
, root
, old
, &tmp
, objectid
);
889 btrfs_tree_unlock(old
);
890 free_extent_buffer(old
);
892 btrfs_set_root_node(new_root_item
, tmp
);
893 /* record when the snapshot was created in key.offset */
894 key
.offset
= trans
->transid
;
895 ret
= btrfs_insert_root(trans
, tree_root
, &key
, new_root_item
);
896 btrfs_tree_unlock(tmp
);
897 free_extent_buffer(tmp
);
901 * insert root back/forward references
903 ret
= btrfs_add_root_ref(trans
, tree_root
, objectid
,
904 parent_root
->root_key
.objectid
,
905 btrfs_ino(parent_inode
), index
,
906 dentry
->d_name
.name
, dentry
->d_name
.len
);
910 key
.offset
= (u64
)-1;
911 pending
->snap
= btrfs_read_fs_root_no_name(root
->fs_info
, &key
);
912 BUG_ON(IS_ERR(pending
->snap
));
914 btrfs_reloc_post_snapshot(trans
, pending
);
915 btrfs_orphan_post_snapshot(trans
, pending
);
917 kfree(new_root_item
);
918 btrfs_block_rsv_release(root
, &pending
->block_rsv
, (u64
)-1);
923 * create all the snapshots we've scheduled for creation
925 static noinline
int create_pending_snapshots(struct btrfs_trans_handle
*trans
,
926 struct btrfs_fs_info
*fs_info
)
928 struct btrfs_pending_snapshot
*pending
;
929 struct list_head
*head
= &trans
->transaction
->pending_snapshots
;
932 list_for_each_entry(pending
, head
, list
) {
934 * We must deal with the delayed items before creating
935 * snapshots, or we will create a snapthot with inconsistent
938 ret
= btrfs_run_delayed_items(trans
, fs_info
->fs_root
);
941 ret
= create_pending_snapshot(trans
, fs_info
, pending
);
947 static void update_super_roots(struct btrfs_root
*root
)
949 struct btrfs_root_item
*root_item
;
950 struct btrfs_super_block
*super
;
952 super
= &root
->fs_info
->super_copy
;
954 root_item
= &root
->fs_info
->chunk_root
->root_item
;
955 super
->chunk_root
= root_item
->bytenr
;
956 super
->chunk_root_generation
= root_item
->generation
;
957 super
->chunk_root_level
= root_item
->level
;
959 root_item
= &root
->fs_info
->tree_root
->root_item
;
960 super
->root
= root_item
->bytenr
;
961 super
->generation
= root_item
->generation
;
962 super
->root_level
= root_item
->level
;
963 if (super
->cache_generation
!= 0 || btrfs_test_opt(root
, SPACE_CACHE
))
964 super
->cache_generation
= root_item
->generation
;
967 int btrfs_transaction_in_commit(struct btrfs_fs_info
*info
)
970 spin_lock(&info
->new_trans_lock
);
971 if (info
->running_transaction
)
972 ret
= info
->running_transaction
->in_commit
;
973 spin_unlock(&info
->new_trans_lock
);
977 int btrfs_transaction_blocked(struct btrfs_fs_info
*info
)
980 spin_lock(&info
->new_trans_lock
);
981 if (info
->running_transaction
)
982 ret
= info
->running_transaction
->blocked
;
983 spin_unlock(&info
->new_trans_lock
);
988 * wait for the current transaction commit to start and block subsequent
991 static void wait_current_trans_commit_start(struct btrfs_root
*root
,
992 struct btrfs_transaction
*trans
)
996 if (trans
->in_commit
)
1000 prepare_to_wait(&root
->fs_info
->transaction_blocked_wait
, &wait
,
1001 TASK_UNINTERRUPTIBLE
);
1002 if (trans
->in_commit
) {
1003 finish_wait(&root
->fs_info
->transaction_blocked_wait
,
1007 mutex_unlock(&root
->fs_info
->trans_mutex
);
1009 mutex_lock(&root
->fs_info
->trans_mutex
);
1010 finish_wait(&root
->fs_info
->transaction_blocked_wait
, &wait
);
1015 * wait for the current transaction to start and then become unblocked.
1018 static void wait_current_trans_commit_start_and_unblock(struct btrfs_root
*root
,
1019 struct btrfs_transaction
*trans
)
1023 if (trans
->commit_done
|| (trans
->in_commit
&& !trans
->blocked
))
1027 prepare_to_wait(&root
->fs_info
->transaction_wait
, &wait
,
1028 TASK_UNINTERRUPTIBLE
);
1029 if (trans
->commit_done
||
1030 (trans
->in_commit
&& !trans
->blocked
)) {
1031 finish_wait(&root
->fs_info
->transaction_wait
,
1035 mutex_unlock(&root
->fs_info
->trans_mutex
);
1037 mutex_lock(&root
->fs_info
->trans_mutex
);
1038 finish_wait(&root
->fs_info
->transaction_wait
,
1044 * commit transactions asynchronously. once btrfs_commit_transaction_async
1045 * returns, any subsequent transaction will not be allowed to join.
1047 struct btrfs_async_commit
{
1048 struct btrfs_trans_handle
*newtrans
;
1049 struct btrfs_root
*root
;
1050 struct delayed_work work
;
1053 static void do_async_commit(struct work_struct
*work
)
1055 struct btrfs_async_commit
*ac
=
1056 container_of(work
, struct btrfs_async_commit
, work
.work
);
1058 btrfs_commit_transaction(ac
->newtrans
, ac
->root
);
1062 int btrfs_commit_transaction_async(struct btrfs_trans_handle
*trans
,
1063 struct btrfs_root
*root
,
1064 int wait_for_unblock
)
1066 struct btrfs_async_commit
*ac
;
1067 struct btrfs_transaction
*cur_trans
;
1069 ac
= kmalloc(sizeof(*ac
), GFP_NOFS
);
1073 INIT_DELAYED_WORK(&ac
->work
, do_async_commit
);
1075 ac
->newtrans
= btrfs_join_transaction(root
, 0);
1076 if (IS_ERR(ac
->newtrans
)) {
1077 int err
= PTR_ERR(ac
->newtrans
);
1082 /* take transaction reference */
1083 mutex_lock(&root
->fs_info
->trans_mutex
);
1084 cur_trans
= trans
->transaction
;
1085 atomic_inc(&cur_trans
->use_count
);
1086 mutex_unlock(&root
->fs_info
->trans_mutex
);
1088 btrfs_end_transaction(trans
, root
);
1089 schedule_delayed_work(&ac
->work
, 0);
1091 /* wait for transaction to start and unblock */
1092 mutex_lock(&root
->fs_info
->trans_mutex
);
1093 if (wait_for_unblock
)
1094 wait_current_trans_commit_start_and_unblock(root
, cur_trans
);
1096 wait_current_trans_commit_start(root
, cur_trans
);
1097 put_transaction(cur_trans
);
1098 mutex_unlock(&root
->fs_info
->trans_mutex
);
1104 * btrfs_transaction state sequence:
1105 * in_commit = 0, blocked = 0 (initial)
1106 * in_commit = 1, blocked = 1
1110 int btrfs_commit_transaction(struct btrfs_trans_handle
*trans
,
1111 struct btrfs_root
*root
)
1113 unsigned long joined
= 0;
1114 struct btrfs_transaction
*cur_trans
;
1115 struct btrfs_transaction
*prev_trans
= NULL
;
1118 int should_grow
= 0;
1119 unsigned long now
= get_seconds();
1120 int flush_on_commit
= btrfs_test_opt(root
, FLUSHONCOMMIT
);
1122 btrfs_run_ordered_operations(root
, 0);
1124 /* make a pass through all the delayed refs we have so far
1125 * any runnings procs may add more while we are here
1127 ret
= btrfs_run_delayed_refs(trans
, root
, 0);
1130 btrfs_trans_release_metadata(trans
, root
);
1132 cur_trans
= trans
->transaction
;
1134 * set the flushing flag so procs in this transaction have to
1135 * start sending their work down.
1137 cur_trans
->delayed_refs
.flushing
= 1;
1139 ret
= btrfs_run_delayed_refs(trans
, root
, 0);
1142 mutex_lock(&root
->fs_info
->trans_mutex
);
1143 if (cur_trans
->in_commit
) {
1144 atomic_inc(&cur_trans
->use_count
);
1145 mutex_unlock(&root
->fs_info
->trans_mutex
);
1146 btrfs_end_transaction(trans
, root
);
1148 ret
= wait_for_commit(root
, cur_trans
);
1151 mutex_lock(&root
->fs_info
->trans_mutex
);
1152 put_transaction(cur_trans
);
1153 mutex_unlock(&root
->fs_info
->trans_mutex
);
1158 trans
->transaction
->in_commit
= 1;
1159 trans
->transaction
->blocked
= 1;
1160 wake_up(&root
->fs_info
->transaction_blocked_wait
);
1162 if (cur_trans
->list
.prev
!= &root
->fs_info
->trans_list
) {
1163 prev_trans
= list_entry(cur_trans
->list
.prev
,
1164 struct btrfs_transaction
, list
);
1165 if (!prev_trans
->commit_done
) {
1166 atomic_inc(&prev_trans
->use_count
);
1167 mutex_unlock(&root
->fs_info
->trans_mutex
);
1169 wait_for_commit(root
, prev_trans
);
1171 mutex_lock(&root
->fs_info
->trans_mutex
);
1172 put_transaction(prev_trans
);
1176 if (now
< cur_trans
->start_time
|| now
- cur_trans
->start_time
< 1)
1180 int snap_pending
= 0;
1181 joined
= cur_trans
->num_joined
;
1182 if (!list_empty(&trans
->transaction
->pending_snapshots
))
1185 WARN_ON(cur_trans
!= trans
->transaction
);
1186 mutex_unlock(&root
->fs_info
->trans_mutex
);
1188 if (flush_on_commit
|| snap_pending
) {
1189 btrfs_start_delalloc_inodes(root
, 1);
1190 ret
= btrfs_wait_ordered_extents(root
, 0, 1);
1194 ret
= btrfs_run_delayed_items(trans
, root
);
1198 * rename don't use btrfs_join_transaction, so, once we
1199 * set the transaction to blocked above, we aren't going
1200 * to get any new ordered operations. We can safely run
1201 * it here and no for sure that nothing new will be added
1204 btrfs_run_ordered_operations(root
, 1);
1206 prepare_to_wait(&cur_trans
->writer_wait
, &wait
,
1207 TASK_UNINTERRUPTIBLE
);
1210 if (atomic_read(&cur_trans
->num_writers
) > 1)
1211 schedule_timeout(MAX_SCHEDULE_TIMEOUT
);
1212 else if (should_grow
)
1213 schedule_timeout(1);
1215 mutex_lock(&root
->fs_info
->trans_mutex
);
1216 finish_wait(&cur_trans
->writer_wait
, &wait
);
1217 } while (atomic_read(&cur_trans
->num_writers
) > 1 ||
1218 (should_grow
&& cur_trans
->num_joined
!= joined
));
1220 ret
= create_pending_snapshots(trans
, root
->fs_info
);
1223 ret
= btrfs_run_delayed_items(trans
, root
);
1226 ret
= btrfs_run_delayed_refs(trans
, root
, (unsigned long)-1);
1229 WARN_ON(cur_trans
!= trans
->transaction
);
1231 btrfs_scrub_pause(root
);
1232 /* btrfs_commit_tree_roots is responsible for getting the
1233 * various roots consistent with each other. Every pointer
1234 * in the tree of tree roots has to point to the most up to date
1235 * root for every subvolume and other tree. So, we have to keep
1236 * the tree logging code from jumping in and changing any
1239 * At this point in the commit, there can't be any tree-log
1240 * writers, but a little lower down we drop the trans mutex
1241 * and let new people in. By holding the tree_log_mutex
1242 * from now until after the super is written, we avoid races
1243 * with the tree-log code.
1245 mutex_lock(&root
->fs_info
->tree_log_mutex
);
1247 ret
= commit_fs_roots(trans
, root
);
1250 /* commit_fs_roots gets rid of all the tree log roots, it is now
1251 * safe to free the root of tree log roots
1253 btrfs_free_log_root_tree(trans
, root
->fs_info
);
1255 ret
= commit_cowonly_roots(trans
, root
);
1258 btrfs_prepare_extent_commit(trans
, root
);
1260 cur_trans
= root
->fs_info
->running_transaction
;
1261 spin_lock(&root
->fs_info
->new_trans_lock
);
1262 root
->fs_info
->running_transaction
= NULL
;
1263 spin_unlock(&root
->fs_info
->new_trans_lock
);
1265 btrfs_set_root_node(&root
->fs_info
->tree_root
->root_item
,
1266 root
->fs_info
->tree_root
->node
);
1267 switch_commit_root(root
->fs_info
->tree_root
);
1269 btrfs_set_root_node(&root
->fs_info
->chunk_root
->root_item
,
1270 root
->fs_info
->chunk_root
->node
);
1271 switch_commit_root(root
->fs_info
->chunk_root
);
1273 update_super_roots(root
);
1275 if (!root
->fs_info
->log_root_recovering
) {
1276 btrfs_set_super_log_root(&root
->fs_info
->super_copy
, 0);
1277 btrfs_set_super_log_root_level(&root
->fs_info
->super_copy
, 0);
1280 memcpy(&root
->fs_info
->super_for_commit
, &root
->fs_info
->super_copy
,
1281 sizeof(root
->fs_info
->super_copy
));
1283 trans
->transaction
->blocked
= 0;
1285 wake_up(&root
->fs_info
->transaction_wait
);
1287 mutex_unlock(&root
->fs_info
->trans_mutex
);
1288 ret
= btrfs_write_and_wait_transaction(trans
, root
);
1290 write_ctree_super(trans
, root
, 0);
1293 * the super is written, we can safely allow the tree-loggers
1294 * to go about their business
1296 mutex_unlock(&root
->fs_info
->tree_log_mutex
);
1298 btrfs_finish_extent_commit(trans
, root
);
1300 mutex_lock(&root
->fs_info
->trans_mutex
);
1302 cur_trans
->commit_done
= 1;
1304 root
->fs_info
->last_trans_committed
= cur_trans
->transid
;
1306 wake_up(&cur_trans
->commit_wait
);
1308 list_del_init(&cur_trans
->list
);
1309 put_transaction(cur_trans
);
1310 put_transaction(cur_trans
);
1312 trace_btrfs_transaction_commit(root
);
1314 mutex_unlock(&root
->fs_info
->trans_mutex
);
1316 btrfs_scrub_continue(root
);
1318 if (current
->journal_info
== trans
)
1319 current
->journal_info
= NULL
;
1321 kmem_cache_free(btrfs_trans_handle_cachep
, trans
);
1323 if (current
!= root
->fs_info
->transaction_kthread
)
1324 btrfs_run_delayed_iputs(root
);
1330 * interface function to delete all the snapshots we have scheduled for deletion
1332 int btrfs_clean_old_snapshots(struct btrfs_root
*root
)
1335 struct btrfs_fs_info
*fs_info
= root
->fs_info
;
1337 mutex_lock(&fs_info
->trans_mutex
);
1338 list_splice_init(&fs_info
->dead_roots
, &list
);
1339 mutex_unlock(&fs_info
->trans_mutex
);
1341 while (!list_empty(&list
)) {
1342 root
= list_entry(list
.next
, struct btrfs_root
, root_list
);
1343 list_del(&root
->root_list
);
1345 btrfs_kill_all_delayed_nodes(root
);
1347 if (btrfs_header_backref_rev(root
->node
) <
1348 BTRFS_MIXED_BACKREF_REV
)
1349 btrfs_drop_snapshot(root
, NULL
, 0);
1351 btrfs_drop_snapshot(root
, NULL
, 1);