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"
31 #define BTRFS_ROOT_TRANS_TAG 0
33 static noinline
void put_transaction(struct btrfs_transaction
*transaction
)
35 WARN_ON(transaction
->use_count
== 0);
36 transaction
->use_count
--;
37 if (transaction
->use_count
== 0) {
38 list_del_init(&transaction
->list
);
39 memset(transaction
, 0, sizeof(*transaction
));
40 kmem_cache_free(btrfs_transaction_cachep
, transaction
);
44 static noinline
void switch_commit_root(struct btrfs_root
*root
)
46 free_extent_buffer(root
->commit_root
);
47 root
->commit_root
= btrfs_root_node(root
);
51 * either allocate a new transaction or hop into the existing one
53 static noinline
int join_transaction(struct btrfs_root
*root
)
55 struct btrfs_transaction
*cur_trans
;
56 cur_trans
= root
->fs_info
->running_transaction
;
58 cur_trans
= kmem_cache_alloc(btrfs_transaction_cachep
,
61 root
->fs_info
->generation
++;
62 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 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
,
86 spin_lock(&root
->fs_info
->new_trans_lock
);
87 root
->fs_info
->running_transaction
= cur_trans
;
88 spin_unlock(&root
->fs_info
->new_trans_lock
);
90 cur_trans
->num_writers
++;
91 cur_trans
->num_joined
++;
98 * this does all the record keeping required to make sure that a reference
99 * counted root is properly recorded in a given transaction. This is required
100 * to make sure the old root from before we joined the transaction is deleted
101 * when the transaction commits
103 static noinline
int record_root_in_trans(struct btrfs_trans_handle
*trans
,
104 struct btrfs_root
*root
)
106 if (root
->ref_cows
&& root
->last_trans
< trans
->transid
) {
107 WARN_ON(root
== root
->fs_info
->extent_root
);
108 WARN_ON(root
->commit_root
!= root
->node
);
110 radix_tree_tag_set(&root
->fs_info
->fs_roots_radix
,
111 (unsigned long)root
->root_key
.objectid
,
112 BTRFS_ROOT_TRANS_TAG
);
113 root
->last_trans
= trans
->transid
;
114 btrfs_init_reloc_root(trans
, root
);
119 int btrfs_record_root_in_trans(struct btrfs_trans_handle
*trans
,
120 struct btrfs_root
*root
)
125 mutex_lock(&root
->fs_info
->trans_mutex
);
126 if (root
->last_trans
== trans
->transid
) {
127 mutex_unlock(&root
->fs_info
->trans_mutex
);
131 record_root_in_trans(trans
, root
);
132 mutex_unlock(&root
->fs_info
->trans_mutex
);
136 /* wait for commit against the current transaction to become unblocked
137 * when this is done, it is safe to start a new transaction, but the current
138 * transaction might not be fully on disk.
140 static void wait_current_trans(struct btrfs_root
*root
)
142 struct btrfs_transaction
*cur_trans
;
144 cur_trans
= root
->fs_info
->running_transaction
;
145 if (cur_trans
&& cur_trans
->blocked
) {
147 cur_trans
->use_count
++;
149 prepare_to_wait(&root
->fs_info
->transaction_wait
, &wait
,
150 TASK_UNINTERRUPTIBLE
);
151 if (!cur_trans
->blocked
)
153 mutex_unlock(&root
->fs_info
->trans_mutex
);
155 mutex_lock(&root
->fs_info
->trans_mutex
);
157 finish_wait(&root
->fs_info
->transaction_wait
, &wait
);
158 put_transaction(cur_trans
);
162 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 h
= kmem_cache_alloc(btrfs_trans_handle_cachep
, GFP_NOFS
);
187 return ERR_PTR(-ENOMEM
);
189 mutex_lock(&root
->fs_info
->trans_mutex
);
190 if (may_wait_transaction(root
, type
))
191 wait_current_trans(root
);
193 ret
= join_transaction(root
);
196 cur_trans
= root
->fs_info
->running_transaction
;
197 cur_trans
->use_count
++;
198 mutex_unlock(&root
->fs_info
->trans_mutex
);
200 h
->transid
= cur_trans
->transid
;
201 h
->transaction
= cur_trans
;
204 h
->bytes_reserved
= 0;
205 h
->delayed_ref_updates
= 0;
209 if (cur_trans
->blocked
&& may_wait_transaction(root
, type
)) {
210 btrfs_commit_transaction(h
, root
);
215 ret
= btrfs_trans_reserve_metadata(h
, root
, num_items
,
217 if (ret
== -EAGAIN
) {
218 btrfs_commit_transaction(h
, root
);
222 btrfs_end_transaction(h
, root
);
227 mutex_lock(&root
->fs_info
->trans_mutex
);
228 record_root_in_trans(h
, root
);
229 mutex_unlock(&root
->fs_info
->trans_mutex
);
231 if (!current
->journal_info
&& type
!= TRANS_USERSPACE
)
232 current
->journal_info
= h
;
236 struct btrfs_trans_handle
*btrfs_start_transaction(struct btrfs_root
*root
,
239 return start_transaction(root
, num_items
, TRANS_START
);
241 struct btrfs_trans_handle
*btrfs_join_transaction(struct btrfs_root
*root
,
244 return start_transaction(root
, 0, TRANS_JOIN
);
247 struct btrfs_trans_handle
*btrfs_start_ioctl_transaction(struct btrfs_root
*r
,
250 return start_transaction(r
, 0, TRANS_USERSPACE
);
253 /* wait for a transaction commit to be fully complete */
254 static noinline
int wait_for_commit(struct btrfs_root
*root
,
255 struct btrfs_transaction
*commit
)
258 mutex_lock(&root
->fs_info
->trans_mutex
);
259 while (!commit
->commit_done
) {
260 prepare_to_wait(&commit
->commit_wait
, &wait
,
261 TASK_UNINTERRUPTIBLE
);
262 if (commit
->commit_done
)
264 mutex_unlock(&root
->fs_info
->trans_mutex
);
266 mutex_lock(&root
->fs_info
->trans_mutex
);
268 mutex_unlock(&root
->fs_info
->trans_mutex
);
269 finish_wait(&commit
->commit_wait
, &wait
);
274 void btrfs_throttle(struct btrfs_root
*root
)
276 mutex_lock(&root
->fs_info
->trans_mutex
);
277 if (!root
->fs_info
->open_ioctl_trans
)
278 wait_current_trans(root
);
279 mutex_unlock(&root
->fs_info
->trans_mutex
);
282 static int should_end_transaction(struct btrfs_trans_handle
*trans
,
283 struct btrfs_root
*root
)
286 ret
= btrfs_block_rsv_check(trans
, root
,
287 &root
->fs_info
->global_block_rsv
, 0, 5);
291 int btrfs_should_end_transaction(struct btrfs_trans_handle
*trans
,
292 struct btrfs_root
*root
)
294 struct btrfs_transaction
*cur_trans
= trans
->transaction
;
297 if (cur_trans
->blocked
|| cur_trans
->delayed_refs
.flushing
)
300 updates
= trans
->delayed_ref_updates
;
301 trans
->delayed_ref_updates
= 0;
303 btrfs_run_delayed_refs(trans
, root
, updates
);
305 return should_end_transaction(trans
, root
);
308 static int __btrfs_end_transaction(struct btrfs_trans_handle
*trans
,
309 struct btrfs_root
*root
, int throttle
)
311 struct btrfs_transaction
*cur_trans
= trans
->transaction
;
312 struct btrfs_fs_info
*info
= root
->fs_info
;
316 unsigned long cur
= trans
->delayed_ref_updates
;
317 trans
->delayed_ref_updates
= 0;
319 trans
->transaction
->delayed_refs
.num_heads_ready
> 64) {
320 trans
->delayed_ref_updates
= 0;
323 * do a full flush if the transaction is trying
326 if (trans
->transaction
->delayed_refs
.flushing
)
328 btrfs_run_delayed_refs(trans
, root
, cur
);
335 btrfs_trans_release_metadata(trans
, root
);
337 if (!root
->fs_info
->open_ioctl_trans
&&
338 should_end_transaction(trans
, root
))
339 trans
->transaction
->blocked
= 1;
341 if (cur_trans
->blocked
&& !cur_trans
->in_commit
) {
343 return btrfs_commit_transaction(trans
, root
);
345 wake_up_process(info
->transaction_kthread
);
348 mutex_lock(&info
->trans_mutex
);
349 WARN_ON(cur_trans
!= info
->running_transaction
);
350 WARN_ON(cur_trans
->num_writers
< 1);
351 cur_trans
->num_writers
--;
353 if (waitqueue_active(&cur_trans
->writer_wait
))
354 wake_up(&cur_trans
->writer_wait
);
355 put_transaction(cur_trans
);
356 mutex_unlock(&info
->trans_mutex
);
358 if (current
->journal_info
== trans
)
359 current
->journal_info
= NULL
;
360 memset(trans
, 0, sizeof(*trans
));
361 kmem_cache_free(btrfs_trans_handle_cachep
, trans
);
364 btrfs_run_delayed_iputs(root
);
369 int btrfs_end_transaction(struct btrfs_trans_handle
*trans
,
370 struct btrfs_root
*root
)
372 return __btrfs_end_transaction(trans
, root
, 0);
375 int btrfs_end_transaction_throttle(struct btrfs_trans_handle
*trans
,
376 struct btrfs_root
*root
)
378 return __btrfs_end_transaction(trans
, root
, 1);
382 * when btree blocks are allocated, they have some corresponding bits set for
383 * them in one of two extent_io trees. This is used to make sure all of
384 * those extents are sent to disk but does not wait on them
386 int btrfs_write_marked_extents(struct btrfs_root
*root
,
387 struct extent_io_tree
*dirty_pages
, int mark
)
393 struct inode
*btree_inode
= root
->fs_info
->btree_inode
;
399 ret
= find_first_extent_bit(dirty_pages
, start
, &start
, &end
,
403 while (start
<= end
) {
406 index
= start
>> PAGE_CACHE_SHIFT
;
407 start
= (u64
)(index
+ 1) << PAGE_CACHE_SHIFT
;
408 page
= find_get_page(btree_inode
->i_mapping
, index
);
412 btree_lock_page_hook(page
);
413 if (!page
->mapping
) {
415 page_cache_release(page
);
419 if (PageWriteback(page
)) {
421 wait_on_page_writeback(page
);
424 page_cache_release(page
);
428 err
= write_one_page(page
, 0);
431 page_cache_release(page
);
440 * when btree blocks are allocated, they have some corresponding bits set for
441 * them in one of two extent_io trees. This is used to make sure all of
442 * those extents are on disk for transaction or log commit. We wait
443 * on all the pages and clear them from the dirty pages state tree
445 int btrfs_wait_marked_extents(struct btrfs_root
*root
,
446 struct extent_io_tree
*dirty_pages
, int mark
)
452 struct inode
*btree_inode
= root
->fs_info
->btree_inode
;
458 ret
= find_first_extent_bit(dirty_pages
, start
, &start
, &end
,
463 clear_extent_bits(dirty_pages
, start
, end
, mark
, GFP_NOFS
);
464 while (start
<= end
) {
465 index
= start
>> PAGE_CACHE_SHIFT
;
466 start
= (u64
)(index
+ 1) << PAGE_CACHE_SHIFT
;
467 page
= find_get_page(btree_inode
->i_mapping
, index
);
470 if (PageDirty(page
)) {
471 btree_lock_page_hook(page
);
472 wait_on_page_writeback(page
);
473 err
= write_one_page(page
, 0);
477 wait_on_page_writeback(page
);
478 page_cache_release(page
);
488 * when btree blocks are allocated, they have some corresponding bits set for
489 * them in one of two extent_io trees. This is used to make sure all of
490 * those extents are on disk for transaction or log commit
492 int btrfs_write_and_wait_marked_extents(struct btrfs_root
*root
,
493 struct extent_io_tree
*dirty_pages
, int mark
)
498 ret
= btrfs_write_marked_extents(root
, dirty_pages
, mark
);
499 ret2
= btrfs_wait_marked_extents(root
, dirty_pages
, mark
);
503 int btrfs_write_and_wait_transaction(struct btrfs_trans_handle
*trans
,
504 struct btrfs_root
*root
)
506 if (!trans
|| !trans
->transaction
) {
507 struct inode
*btree_inode
;
508 btree_inode
= root
->fs_info
->btree_inode
;
509 return filemap_write_and_wait(btree_inode
->i_mapping
);
511 return btrfs_write_and_wait_marked_extents(root
,
512 &trans
->transaction
->dirty_pages
,
517 * this is used to update the root pointer in the tree of tree roots.
519 * But, in the case of the extent allocation tree, updating the root
520 * pointer may allocate blocks which may change the root of the extent
523 * So, this loops and repeats and makes sure the cowonly root didn't
524 * change while the root pointer was being updated in the metadata.
526 static int update_cowonly_root(struct btrfs_trans_handle
*trans
,
527 struct btrfs_root
*root
)
532 struct btrfs_root
*tree_root
= root
->fs_info
->tree_root
;
534 old_root_used
= btrfs_root_used(&root
->root_item
);
535 btrfs_write_dirty_block_groups(trans
, root
);
538 old_root_bytenr
= btrfs_root_bytenr(&root
->root_item
);
539 if (old_root_bytenr
== root
->node
->start
&&
540 old_root_used
== btrfs_root_used(&root
->root_item
))
543 btrfs_set_root_node(&root
->root_item
, root
->node
);
544 ret
= btrfs_update_root(trans
, tree_root
,
549 old_root_used
= btrfs_root_used(&root
->root_item
);
550 ret
= btrfs_write_dirty_block_groups(trans
, root
);
554 if (root
!= root
->fs_info
->extent_root
)
555 switch_commit_root(root
);
561 * update all the cowonly tree roots on disk
563 static noinline
int commit_cowonly_roots(struct btrfs_trans_handle
*trans
,
564 struct btrfs_root
*root
)
566 struct btrfs_fs_info
*fs_info
= root
->fs_info
;
567 struct list_head
*next
;
568 struct extent_buffer
*eb
;
571 ret
= btrfs_run_delayed_refs(trans
, root
, (unsigned long)-1);
574 eb
= btrfs_lock_root_node(fs_info
->tree_root
);
575 btrfs_cow_block(trans
, fs_info
->tree_root
, eb
, NULL
, 0, &eb
);
576 btrfs_tree_unlock(eb
);
577 free_extent_buffer(eb
);
579 ret
= btrfs_run_delayed_refs(trans
, root
, (unsigned long)-1);
582 while (!list_empty(&fs_info
->dirty_cowonly_roots
)) {
583 next
= fs_info
->dirty_cowonly_roots
.next
;
585 root
= list_entry(next
, struct btrfs_root
, dirty_list
);
587 update_cowonly_root(trans
, root
);
590 down_write(&fs_info
->extent_commit_sem
);
591 switch_commit_root(fs_info
->extent_root
);
592 up_write(&fs_info
->extent_commit_sem
);
598 * dead roots are old snapshots that need to be deleted. This allocates
599 * a dirty root struct and adds it into the list of dead roots that need to
602 int btrfs_add_dead_root(struct btrfs_root
*root
)
604 mutex_lock(&root
->fs_info
->trans_mutex
);
605 list_add(&root
->root_list
, &root
->fs_info
->dead_roots
);
606 mutex_unlock(&root
->fs_info
->trans_mutex
);
611 * update all the cowonly tree roots on disk
613 static noinline
int commit_fs_roots(struct btrfs_trans_handle
*trans
,
614 struct btrfs_root
*root
)
616 struct btrfs_root
*gang
[8];
617 struct btrfs_fs_info
*fs_info
= root
->fs_info
;
623 ret
= radix_tree_gang_lookup_tag(&fs_info
->fs_roots_radix
,
626 BTRFS_ROOT_TRANS_TAG
);
629 for (i
= 0; i
< ret
; i
++) {
631 radix_tree_tag_clear(&fs_info
->fs_roots_radix
,
632 (unsigned long)root
->root_key
.objectid
,
633 BTRFS_ROOT_TRANS_TAG
);
635 btrfs_free_log(trans
, root
);
636 btrfs_update_reloc_root(trans
, root
);
637 btrfs_orphan_commit_root(trans
, root
);
639 if (root
->commit_root
!= root
->node
) {
640 switch_commit_root(root
);
641 btrfs_set_root_node(&root
->root_item
,
645 err
= btrfs_update_root(trans
, fs_info
->tree_root
,
656 * defrag a given btree. If cacheonly == 1, this won't read from the disk,
657 * otherwise every leaf in the btree is read and defragged.
659 int btrfs_defrag_root(struct btrfs_root
*root
, int cacheonly
)
661 struct btrfs_fs_info
*info
= root
->fs_info
;
662 struct btrfs_trans_handle
*trans
;
666 if (xchg(&root
->defrag_running
, 1))
670 trans
= btrfs_start_transaction(root
, 0);
672 return PTR_ERR(trans
);
674 ret
= btrfs_defrag_leaves(trans
, root
, cacheonly
);
676 nr
= trans
->blocks_used
;
677 btrfs_end_transaction(trans
, root
);
678 btrfs_btree_balance_dirty(info
->tree_root
, nr
);
681 if (root
->fs_info
->closing
|| ret
!= -EAGAIN
)
684 root
->defrag_running
= 0;
690 * new snapshots need to be created at a very specific time in the
691 * transaction commit. This does the actual creation
693 static noinline
int create_pending_snapshot(struct btrfs_trans_handle
*trans
,
694 struct btrfs_fs_info
*fs_info
,
695 struct btrfs_pending_snapshot
*pending
)
697 struct btrfs_key key
;
698 struct btrfs_root_item
*new_root_item
;
699 struct btrfs_root
*tree_root
= fs_info
->tree_root
;
700 struct btrfs_root
*root
= pending
->root
;
701 struct btrfs_root
*parent_root
;
702 struct inode
*parent_inode
;
703 struct dentry
*dentry
;
704 struct extent_buffer
*tmp
;
705 struct extent_buffer
*old
;
712 new_root_item
= kmalloc(sizeof(*new_root_item
), GFP_NOFS
);
713 if (!new_root_item
) {
714 pending
->error
= -ENOMEM
;
718 ret
= btrfs_find_free_objectid(trans
, tree_root
, 0, &objectid
);
720 pending
->error
= ret
;
724 btrfs_reloc_pre_snapshot(trans
, pending
, &to_reserve
);
725 btrfs_orphan_pre_snapshot(trans
, pending
, &to_reserve
);
727 if (to_reserve
> 0) {
728 ret
= btrfs_block_rsv_add(trans
, root
, &pending
->block_rsv
,
729 to_reserve
, &retries
);
731 pending
->error
= ret
;
736 key
.objectid
= objectid
;
737 key
.offset
= (u64
)-1;
738 key
.type
= BTRFS_ROOT_ITEM_KEY
;
740 trans
->block_rsv
= &pending
->block_rsv
;
742 dentry
= pending
->dentry
;
743 parent_inode
= dentry
->d_parent
->d_inode
;
744 parent_root
= BTRFS_I(parent_inode
)->root
;
745 record_root_in_trans(trans
, parent_root
);
748 * insert the directory item
750 ret
= btrfs_set_inode_index(parent_inode
, &index
);
752 ret
= btrfs_insert_dir_item(trans
, parent_root
,
753 dentry
->d_name
.name
, dentry
->d_name
.len
,
754 parent_inode
->i_ino
, &key
,
755 BTRFS_FT_DIR
, index
);
758 btrfs_i_size_write(parent_inode
, parent_inode
->i_size
+
759 dentry
->d_name
.len
* 2);
760 ret
= btrfs_update_inode(trans
, parent_root
, parent_inode
);
763 record_root_in_trans(trans
, root
);
764 btrfs_set_root_last_snapshot(&root
->root_item
, trans
->transid
);
765 memcpy(new_root_item
, &root
->root_item
, sizeof(*new_root_item
));
767 old
= btrfs_lock_root_node(root
);
768 btrfs_cow_block(trans
, root
, old
, NULL
, 0, &old
);
769 btrfs_set_lock_blocking(old
);
771 btrfs_copy_root(trans
, root
, old
, &tmp
, objectid
);
772 btrfs_tree_unlock(old
);
773 free_extent_buffer(old
);
775 btrfs_set_root_node(new_root_item
, tmp
);
776 /* record when the snapshot was created in key.offset */
777 key
.offset
= trans
->transid
;
778 ret
= btrfs_insert_root(trans
, tree_root
, &key
, new_root_item
);
779 btrfs_tree_unlock(tmp
);
780 free_extent_buffer(tmp
);
784 * insert root back/forward references
786 ret
= btrfs_add_root_ref(trans
, tree_root
, objectid
,
787 parent_root
->root_key
.objectid
,
788 parent_inode
->i_ino
, index
,
789 dentry
->d_name
.name
, dentry
->d_name
.len
);
792 key
.offset
= (u64
)-1;
793 pending
->snap
= btrfs_read_fs_root_no_name(root
->fs_info
, &key
);
794 BUG_ON(IS_ERR(pending
->snap
));
796 btrfs_reloc_post_snapshot(trans
, pending
);
797 btrfs_orphan_post_snapshot(trans
, pending
);
799 kfree(new_root_item
);
800 btrfs_block_rsv_release(root
, &pending
->block_rsv
, (u64
)-1);
805 * create all the snapshots we've scheduled for creation
807 static noinline
int create_pending_snapshots(struct btrfs_trans_handle
*trans
,
808 struct btrfs_fs_info
*fs_info
)
810 struct btrfs_pending_snapshot
*pending
;
811 struct list_head
*head
= &trans
->transaction
->pending_snapshots
;
814 list_for_each_entry(pending
, head
, list
) {
815 ret
= create_pending_snapshot(trans
, fs_info
, pending
);
821 static void update_super_roots(struct btrfs_root
*root
)
823 struct btrfs_root_item
*root_item
;
824 struct btrfs_super_block
*super
;
826 super
= &root
->fs_info
->super_copy
;
828 root_item
= &root
->fs_info
->chunk_root
->root_item
;
829 super
->chunk_root
= root_item
->bytenr
;
830 super
->chunk_root_generation
= root_item
->generation
;
831 super
->chunk_root_level
= root_item
->level
;
833 root_item
= &root
->fs_info
->tree_root
->root_item
;
834 super
->root
= root_item
->bytenr
;
835 super
->generation
= root_item
->generation
;
836 super
->root_level
= root_item
->level
;
839 int btrfs_transaction_in_commit(struct btrfs_fs_info
*info
)
842 spin_lock(&info
->new_trans_lock
);
843 if (info
->running_transaction
)
844 ret
= info
->running_transaction
->in_commit
;
845 spin_unlock(&info
->new_trans_lock
);
849 int btrfs_transaction_blocked(struct btrfs_fs_info
*info
)
852 spin_lock(&info
->new_trans_lock
);
853 if (info
->running_transaction
)
854 ret
= info
->running_transaction
->blocked
;
855 spin_unlock(&info
->new_trans_lock
);
859 int btrfs_commit_transaction(struct btrfs_trans_handle
*trans
,
860 struct btrfs_root
*root
)
862 unsigned long joined
= 0;
863 unsigned long timeout
= 1;
864 struct btrfs_transaction
*cur_trans
;
865 struct btrfs_transaction
*prev_trans
= NULL
;
869 unsigned long now
= get_seconds();
870 int flush_on_commit
= btrfs_test_opt(root
, FLUSHONCOMMIT
);
872 btrfs_run_ordered_operations(root
, 0);
874 /* make a pass through all the delayed refs we have so far
875 * any runnings procs may add more while we are here
877 ret
= btrfs_run_delayed_refs(trans
, root
, 0);
880 btrfs_trans_release_metadata(trans
, root
);
882 cur_trans
= trans
->transaction
;
884 * set the flushing flag so procs in this transaction have to
885 * start sending their work down.
887 cur_trans
->delayed_refs
.flushing
= 1;
889 ret
= btrfs_run_delayed_refs(trans
, root
, 0);
892 mutex_lock(&root
->fs_info
->trans_mutex
);
893 if (cur_trans
->in_commit
) {
894 cur_trans
->use_count
++;
895 mutex_unlock(&root
->fs_info
->trans_mutex
);
896 btrfs_end_transaction(trans
, root
);
898 ret
= wait_for_commit(root
, cur_trans
);
901 mutex_lock(&root
->fs_info
->trans_mutex
);
902 put_transaction(cur_trans
);
903 mutex_unlock(&root
->fs_info
->trans_mutex
);
908 trans
->transaction
->in_commit
= 1;
909 trans
->transaction
->blocked
= 1;
910 if (cur_trans
->list
.prev
!= &root
->fs_info
->trans_list
) {
911 prev_trans
= list_entry(cur_trans
->list
.prev
,
912 struct btrfs_transaction
, list
);
913 if (!prev_trans
->commit_done
) {
914 prev_trans
->use_count
++;
915 mutex_unlock(&root
->fs_info
->trans_mutex
);
917 wait_for_commit(root
, prev_trans
);
919 mutex_lock(&root
->fs_info
->trans_mutex
);
920 put_transaction(prev_trans
);
924 if (now
< cur_trans
->start_time
|| now
- cur_trans
->start_time
< 1)
928 int snap_pending
= 0;
929 joined
= cur_trans
->num_joined
;
930 if (!list_empty(&trans
->transaction
->pending_snapshots
))
933 WARN_ON(cur_trans
!= trans
->transaction
);
934 if (cur_trans
->num_writers
> 1)
935 timeout
= MAX_SCHEDULE_TIMEOUT
;
936 else if (should_grow
)
939 mutex_unlock(&root
->fs_info
->trans_mutex
);
941 if (flush_on_commit
|| snap_pending
) {
942 btrfs_start_delalloc_inodes(root
, 1);
943 ret
= btrfs_wait_ordered_extents(root
, 0, 1);
948 * rename don't use btrfs_join_transaction, so, once we
949 * set the transaction to blocked above, we aren't going
950 * to get any new ordered operations. We can safely run
951 * it here and no for sure that nothing new will be added
954 btrfs_run_ordered_operations(root
, 1);
956 prepare_to_wait(&cur_trans
->writer_wait
, &wait
,
957 TASK_UNINTERRUPTIBLE
);
960 if (cur_trans
->num_writers
> 1 || should_grow
)
961 schedule_timeout(timeout
);
963 mutex_lock(&root
->fs_info
->trans_mutex
);
964 finish_wait(&cur_trans
->writer_wait
, &wait
);
965 } while (cur_trans
->num_writers
> 1 ||
966 (should_grow
&& cur_trans
->num_joined
!= joined
));
968 ret
= create_pending_snapshots(trans
, root
->fs_info
);
971 ret
= btrfs_run_delayed_refs(trans
, root
, (unsigned long)-1);
974 WARN_ON(cur_trans
!= trans
->transaction
);
976 /* btrfs_commit_tree_roots is responsible for getting the
977 * various roots consistent with each other. Every pointer
978 * in the tree of tree roots has to point to the most up to date
979 * root for every subvolume and other tree. So, we have to keep
980 * the tree logging code from jumping in and changing any
983 * At this point in the commit, there can't be any tree-log
984 * writers, but a little lower down we drop the trans mutex
985 * and let new people in. By holding the tree_log_mutex
986 * from now until after the super is written, we avoid races
987 * with the tree-log code.
989 mutex_lock(&root
->fs_info
->tree_log_mutex
);
991 ret
= commit_fs_roots(trans
, root
);
994 /* commit_fs_roots gets rid of all the tree log roots, it is now
995 * safe to free the root of tree log roots
997 btrfs_free_log_root_tree(trans
, root
->fs_info
);
999 ret
= commit_cowonly_roots(trans
, root
);
1002 btrfs_prepare_extent_commit(trans
, root
);
1004 cur_trans
= root
->fs_info
->running_transaction
;
1005 spin_lock(&root
->fs_info
->new_trans_lock
);
1006 root
->fs_info
->running_transaction
= NULL
;
1007 spin_unlock(&root
->fs_info
->new_trans_lock
);
1009 btrfs_set_root_node(&root
->fs_info
->tree_root
->root_item
,
1010 root
->fs_info
->tree_root
->node
);
1011 switch_commit_root(root
->fs_info
->tree_root
);
1013 btrfs_set_root_node(&root
->fs_info
->chunk_root
->root_item
,
1014 root
->fs_info
->chunk_root
->node
);
1015 switch_commit_root(root
->fs_info
->chunk_root
);
1017 update_super_roots(root
);
1019 if (!root
->fs_info
->log_root_recovering
) {
1020 btrfs_set_super_log_root(&root
->fs_info
->super_copy
, 0);
1021 btrfs_set_super_log_root_level(&root
->fs_info
->super_copy
, 0);
1024 memcpy(&root
->fs_info
->super_for_commit
, &root
->fs_info
->super_copy
,
1025 sizeof(root
->fs_info
->super_copy
));
1027 trans
->transaction
->blocked
= 0;
1029 wake_up(&root
->fs_info
->transaction_wait
);
1031 mutex_unlock(&root
->fs_info
->trans_mutex
);
1032 ret
= btrfs_write_and_wait_transaction(trans
, root
);
1034 write_ctree_super(trans
, root
, 0);
1037 * the super is written, we can safely allow the tree-loggers
1038 * to go about their business
1040 mutex_unlock(&root
->fs_info
->tree_log_mutex
);
1042 btrfs_finish_extent_commit(trans
, root
);
1044 mutex_lock(&root
->fs_info
->trans_mutex
);
1046 cur_trans
->commit_done
= 1;
1048 root
->fs_info
->last_trans_committed
= cur_trans
->transid
;
1050 wake_up(&cur_trans
->commit_wait
);
1052 put_transaction(cur_trans
);
1053 put_transaction(cur_trans
);
1055 mutex_unlock(&root
->fs_info
->trans_mutex
);
1057 if (current
->journal_info
== trans
)
1058 current
->journal_info
= NULL
;
1060 kmem_cache_free(btrfs_trans_handle_cachep
, trans
);
1062 if (current
!= root
->fs_info
->transaction_kthread
)
1063 btrfs_run_delayed_iputs(root
);
1069 * interface function to delete all the snapshots we have scheduled for deletion
1071 int btrfs_clean_old_snapshots(struct btrfs_root
*root
)
1074 struct btrfs_fs_info
*fs_info
= root
->fs_info
;
1076 mutex_lock(&fs_info
->trans_mutex
);
1077 list_splice_init(&fs_info
->dead_roots
, &list
);
1078 mutex_unlock(&fs_info
->trans_mutex
);
1080 while (!list_empty(&list
)) {
1081 root
= list_entry(list
.next
, struct btrfs_root
, root_list
);
1082 list_del(&root
->root_list
);
1084 if (btrfs_header_backref_rev(root
->node
) <
1085 BTRFS_MIXED_BACKREF_REV
)
1086 btrfs_drop_snapshot(root
, NULL
, 0);
1088 btrfs_drop_snapshot(root
, NULL
, 1);