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"
33 #define BTRFS_ROOT_TRANS_TAG 0
35 void put_transaction(struct btrfs_transaction
*transaction
)
37 WARN_ON(atomic_read(&transaction
->use_count
) == 0);
38 if (atomic_dec_and_test(&transaction
->use_count
)) {
39 BUG_ON(!list_empty(&transaction
->list
));
40 WARN_ON(transaction
->delayed_refs
.root
.rb_node
);
41 WARN_ON(!list_empty(&transaction
->delayed_refs
.seq_head
));
42 memset(transaction
, 0, sizeof(*transaction
));
43 kmem_cache_free(btrfs_transaction_cachep
, transaction
);
47 static noinline
void switch_commit_root(struct btrfs_root
*root
)
49 free_extent_buffer(root
->commit_root
);
50 root
->commit_root
= btrfs_root_node(root
);
54 * either allocate a new transaction or hop into the existing one
56 static noinline
int join_transaction(struct btrfs_root
*root
, int nofail
)
58 struct btrfs_transaction
*cur_trans
;
59 struct btrfs_fs_info
*fs_info
= root
->fs_info
;
61 spin_lock(&fs_info
->trans_lock
);
63 /* The file system has been taken offline. No new transactions. */
64 if (fs_info
->fs_state
& BTRFS_SUPER_FLAG_ERROR
) {
65 spin_unlock(&fs_info
->trans_lock
);
69 if (fs_info
->trans_no_join
) {
71 spin_unlock(&fs_info
->trans_lock
);
76 cur_trans
= fs_info
->running_transaction
;
78 if (cur_trans
->aborted
) {
79 spin_unlock(&fs_info
->trans_lock
);
80 return cur_trans
->aborted
;
82 atomic_inc(&cur_trans
->use_count
);
83 atomic_inc(&cur_trans
->num_writers
);
84 cur_trans
->num_joined
++;
85 spin_unlock(&fs_info
->trans_lock
);
88 spin_unlock(&fs_info
->trans_lock
);
90 cur_trans
= kmem_cache_alloc(btrfs_transaction_cachep
, GFP_NOFS
);
94 spin_lock(&fs_info
->trans_lock
);
95 if (fs_info
->running_transaction
) {
97 * someone started a transaction after we unlocked. Make sure
98 * to redo the trans_no_join checks above
100 kmem_cache_free(btrfs_transaction_cachep
, cur_trans
);
101 cur_trans
= fs_info
->running_transaction
;
105 atomic_set(&cur_trans
->num_writers
, 1);
106 cur_trans
->num_joined
= 0;
107 init_waitqueue_head(&cur_trans
->writer_wait
);
108 init_waitqueue_head(&cur_trans
->commit_wait
);
109 cur_trans
->in_commit
= 0;
110 cur_trans
->blocked
= 0;
112 * One for this trans handle, one so it will live on until we
113 * commit the transaction.
115 atomic_set(&cur_trans
->use_count
, 2);
116 cur_trans
->commit_done
= 0;
117 cur_trans
->start_time
= get_seconds();
119 cur_trans
->delayed_refs
.root
= RB_ROOT
;
120 cur_trans
->delayed_refs
.num_entries
= 0;
121 cur_trans
->delayed_refs
.num_heads_ready
= 0;
122 cur_trans
->delayed_refs
.num_heads
= 0;
123 cur_trans
->delayed_refs
.flushing
= 0;
124 cur_trans
->delayed_refs
.run_delayed_start
= 0;
125 cur_trans
->delayed_refs
.seq
= 1;
128 * although the tree mod log is per file system and not per transaction,
129 * the log must never go across transaction boundaries.
132 if (!list_empty(&fs_info
->tree_mod_seq_list
)) {
133 printk(KERN_ERR
"btrfs: tree_mod_seq_list not empty when "
134 "creating a fresh transaction\n");
137 if (!RB_EMPTY_ROOT(&fs_info
->tree_mod_log
)) {
138 printk(KERN_ERR
"btrfs: tree_mod_log rb tree not empty when "
139 "creating a fresh transaction\n");
142 atomic_set(&fs_info
->tree_mod_seq
, 0);
144 init_waitqueue_head(&cur_trans
->delayed_refs
.seq_wait
);
145 spin_lock_init(&cur_trans
->commit_lock
);
146 spin_lock_init(&cur_trans
->delayed_refs
.lock
);
147 INIT_LIST_HEAD(&cur_trans
->delayed_refs
.seq_head
);
149 INIT_LIST_HEAD(&cur_trans
->pending_snapshots
);
150 list_add_tail(&cur_trans
->list
, &fs_info
->trans_list
);
151 extent_io_tree_init(&cur_trans
->dirty_pages
,
152 fs_info
->btree_inode
->i_mapping
);
153 fs_info
->generation
++;
154 cur_trans
->transid
= fs_info
->generation
;
155 fs_info
->running_transaction
= cur_trans
;
156 cur_trans
->aborted
= 0;
157 spin_unlock(&fs_info
->trans_lock
);
163 * this does all the record keeping required to make sure that a reference
164 * counted root is properly recorded in a given transaction. This is required
165 * to make sure the old root from before we joined the transaction is deleted
166 * when the transaction commits
168 static int record_root_in_trans(struct btrfs_trans_handle
*trans
,
169 struct btrfs_root
*root
)
171 if (root
->ref_cows
&& root
->last_trans
< trans
->transid
) {
172 WARN_ON(root
== root
->fs_info
->extent_root
);
173 WARN_ON(root
->commit_root
!= root
->node
);
176 * see below for in_trans_setup usage rules
177 * we have the reloc mutex held now, so there
178 * is only one writer in this function
180 root
->in_trans_setup
= 1;
182 /* make sure readers find in_trans_setup before
183 * they find our root->last_trans update
187 spin_lock(&root
->fs_info
->fs_roots_radix_lock
);
188 if (root
->last_trans
== trans
->transid
) {
189 spin_unlock(&root
->fs_info
->fs_roots_radix_lock
);
192 radix_tree_tag_set(&root
->fs_info
->fs_roots_radix
,
193 (unsigned long)root
->root_key
.objectid
,
194 BTRFS_ROOT_TRANS_TAG
);
195 spin_unlock(&root
->fs_info
->fs_roots_radix_lock
);
196 root
->last_trans
= trans
->transid
;
198 /* this is pretty tricky. We don't want to
199 * take the relocation lock in btrfs_record_root_in_trans
200 * unless we're really doing the first setup for this root in
203 * Normally we'd use root->last_trans as a flag to decide
204 * if we want to take the expensive mutex.
206 * But, we have to set root->last_trans before we
207 * init the relocation root, otherwise, we trip over warnings
208 * in ctree.c. The solution used here is to flag ourselves
209 * with root->in_trans_setup. When this is 1, we're still
210 * fixing up the reloc trees and everyone must wait.
212 * When this is zero, they can trust root->last_trans and fly
213 * through btrfs_record_root_in_trans without having to take the
214 * lock. smp_wmb() makes sure that all the writes above are
215 * done before we pop in the zero below
217 btrfs_init_reloc_root(trans
, root
);
219 root
->in_trans_setup
= 0;
225 int btrfs_record_root_in_trans(struct btrfs_trans_handle
*trans
,
226 struct btrfs_root
*root
)
232 * see record_root_in_trans for comments about in_trans_setup usage
236 if (root
->last_trans
== trans
->transid
&&
237 !root
->in_trans_setup
)
240 mutex_lock(&root
->fs_info
->reloc_mutex
);
241 record_root_in_trans(trans
, root
);
242 mutex_unlock(&root
->fs_info
->reloc_mutex
);
247 /* wait for commit against the current transaction to become unblocked
248 * when this is done, it is safe to start a new transaction, but the current
249 * transaction might not be fully on disk.
251 static void wait_current_trans(struct btrfs_root
*root
)
253 struct btrfs_transaction
*cur_trans
;
255 spin_lock(&root
->fs_info
->trans_lock
);
256 cur_trans
= root
->fs_info
->running_transaction
;
257 if (cur_trans
&& cur_trans
->blocked
) {
258 atomic_inc(&cur_trans
->use_count
);
259 spin_unlock(&root
->fs_info
->trans_lock
);
261 wait_event(root
->fs_info
->transaction_wait
,
262 !cur_trans
->blocked
);
263 put_transaction(cur_trans
);
265 spin_unlock(&root
->fs_info
->trans_lock
);
269 enum btrfs_trans_type
{
276 static int may_wait_transaction(struct btrfs_root
*root
, int type
)
278 if (root
->fs_info
->log_root_recovering
)
281 if (type
== TRANS_USERSPACE
)
284 if (type
== TRANS_START
&&
285 !atomic_read(&root
->fs_info
->open_ioctl_trans
))
291 static struct btrfs_trans_handle
*start_transaction(struct btrfs_root
*root
,
292 u64 num_items
, int type
)
294 struct btrfs_trans_handle
*h
;
295 struct btrfs_transaction
*cur_trans
;
299 if (root
->fs_info
->fs_state
& BTRFS_SUPER_FLAG_ERROR
)
300 return ERR_PTR(-EROFS
);
302 if (current
->journal_info
) {
303 WARN_ON(type
!= TRANS_JOIN
&& type
!= TRANS_JOIN_NOLOCK
);
304 h
= current
->journal_info
;
306 h
->orig_rsv
= h
->block_rsv
;
312 * Do the reservation before we join the transaction so we can do all
313 * the appropriate flushing if need be.
315 if (num_items
> 0 && root
!= root
->fs_info
->chunk_root
) {
316 num_bytes
= btrfs_calc_trans_metadata_size(root
, num_items
);
317 ret
= btrfs_block_rsv_add(root
,
318 &root
->fs_info
->trans_block_rsv
,
324 h
= kmem_cache_alloc(btrfs_trans_handle_cachep
, GFP_NOFS
);
326 return ERR_PTR(-ENOMEM
);
328 if (may_wait_transaction(root
, type
))
329 wait_current_trans(root
);
332 ret
= join_transaction(root
, type
== TRANS_JOIN_NOLOCK
);
334 wait_current_trans(root
);
335 } while (ret
== -EBUSY
);
338 kmem_cache_free(btrfs_trans_handle_cachep
, h
);
342 cur_trans
= root
->fs_info
->running_transaction
;
344 h
->transid
= cur_trans
->transid
;
345 h
->transaction
= cur_trans
;
347 h
->bytes_reserved
= 0;
348 h
->delayed_ref_updates
= 0;
355 if (cur_trans
->blocked
&& may_wait_transaction(root
, type
)) {
356 btrfs_commit_transaction(h
, root
);
361 trace_btrfs_space_reservation(root
->fs_info
, "transaction",
362 h
->transid
, num_bytes
, 1);
363 h
->block_rsv
= &root
->fs_info
->trans_block_rsv
;
364 h
->bytes_reserved
= num_bytes
;
368 btrfs_record_root_in_trans(h
, root
);
370 if (!current
->journal_info
&& type
!= TRANS_USERSPACE
)
371 current
->journal_info
= h
;
375 struct btrfs_trans_handle
*btrfs_start_transaction(struct btrfs_root
*root
,
378 return start_transaction(root
, num_items
, TRANS_START
);
380 struct btrfs_trans_handle
*btrfs_join_transaction(struct btrfs_root
*root
)
382 return start_transaction(root
, 0, TRANS_JOIN
);
385 struct btrfs_trans_handle
*btrfs_join_transaction_nolock(struct btrfs_root
*root
)
387 return start_transaction(root
, 0, TRANS_JOIN_NOLOCK
);
390 struct btrfs_trans_handle
*btrfs_start_ioctl_transaction(struct btrfs_root
*root
)
392 return start_transaction(root
, 0, TRANS_USERSPACE
);
395 /* wait for a transaction commit to be fully complete */
396 static noinline
void wait_for_commit(struct btrfs_root
*root
,
397 struct btrfs_transaction
*commit
)
399 wait_event(commit
->commit_wait
, commit
->commit_done
);
402 int btrfs_wait_for_commit(struct btrfs_root
*root
, u64 transid
)
404 struct btrfs_transaction
*cur_trans
= NULL
, *t
;
409 if (transid
<= root
->fs_info
->last_trans_committed
)
412 /* find specified transaction */
413 spin_lock(&root
->fs_info
->trans_lock
);
414 list_for_each_entry(t
, &root
->fs_info
->trans_list
, list
) {
415 if (t
->transid
== transid
) {
417 atomic_inc(&cur_trans
->use_count
);
420 if (t
->transid
> transid
)
423 spin_unlock(&root
->fs_info
->trans_lock
);
426 goto out
; /* bad transid */
428 /* find newest transaction that is committing | committed */
429 spin_lock(&root
->fs_info
->trans_lock
);
430 list_for_each_entry_reverse(t
, &root
->fs_info
->trans_list
,
436 atomic_inc(&cur_trans
->use_count
);
440 spin_unlock(&root
->fs_info
->trans_lock
);
442 goto out
; /* nothing committing|committed */
445 wait_for_commit(root
, cur_trans
);
447 put_transaction(cur_trans
);
453 void btrfs_throttle(struct btrfs_root
*root
)
455 if (!atomic_read(&root
->fs_info
->open_ioctl_trans
))
456 wait_current_trans(root
);
459 static int should_end_transaction(struct btrfs_trans_handle
*trans
,
460 struct btrfs_root
*root
)
464 ret
= btrfs_block_rsv_check(root
, &root
->fs_info
->global_block_rsv
, 5);
468 int btrfs_should_end_transaction(struct btrfs_trans_handle
*trans
,
469 struct btrfs_root
*root
)
471 struct btrfs_transaction
*cur_trans
= trans
->transaction
;
472 struct btrfs_block_rsv
*rsv
= trans
->block_rsv
;
477 if (cur_trans
->blocked
|| cur_trans
->delayed_refs
.flushing
)
481 * We need to do this in case we're deleting csums so the global block
482 * rsv get's used instead of the csum block rsv.
484 trans
->block_rsv
= NULL
;
486 updates
= trans
->delayed_ref_updates
;
487 trans
->delayed_ref_updates
= 0;
489 err
= btrfs_run_delayed_refs(trans
, root
, updates
);
490 if (err
) /* Error code will also eval true */
494 trans
->block_rsv
= rsv
;
496 return should_end_transaction(trans
, root
);
499 static int __btrfs_end_transaction(struct btrfs_trans_handle
*trans
,
500 struct btrfs_root
*root
, int throttle
, int lock
)
502 struct btrfs_transaction
*cur_trans
= trans
->transaction
;
503 struct btrfs_fs_info
*info
= root
->fs_info
;
507 if (--trans
->use_count
) {
508 trans
->block_rsv
= trans
->orig_rsv
;
512 btrfs_trans_release_metadata(trans
, root
);
513 trans
->block_rsv
= NULL
;
515 unsigned long cur
= trans
->delayed_ref_updates
;
516 trans
->delayed_ref_updates
= 0;
518 trans
->transaction
->delayed_refs
.num_heads_ready
> 64) {
519 trans
->delayed_ref_updates
= 0;
520 btrfs_run_delayed_refs(trans
, root
, cur
);
527 if (lock
&& !atomic_read(&root
->fs_info
->open_ioctl_trans
) &&
528 should_end_transaction(trans
, root
)) {
529 trans
->transaction
->blocked
= 1;
533 if (lock
&& cur_trans
->blocked
&& !cur_trans
->in_commit
) {
536 * We may race with somebody else here so end up having
537 * to call end_transaction on ourselves again, so inc
541 return btrfs_commit_transaction(trans
, root
);
543 wake_up_process(info
->transaction_kthread
);
547 WARN_ON(cur_trans
!= info
->running_transaction
);
548 WARN_ON(atomic_read(&cur_trans
->num_writers
) < 1);
549 atomic_dec(&cur_trans
->num_writers
);
552 if (waitqueue_active(&cur_trans
->writer_wait
))
553 wake_up(&cur_trans
->writer_wait
);
554 put_transaction(cur_trans
);
556 if (current
->journal_info
== trans
)
557 current
->journal_info
= NULL
;
560 btrfs_run_delayed_iputs(root
);
562 if (trans
->aborted
||
563 root
->fs_info
->fs_state
& BTRFS_SUPER_FLAG_ERROR
) {
567 memset(trans
, 0, sizeof(*trans
));
568 kmem_cache_free(btrfs_trans_handle_cachep
, trans
);
572 int btrfs_end_transaction(struct btrfs_trans_handle
*trans
,
573 struct btrfs_root
*root
)
577 ret
= __btrfs_end_transaction(trans
, root
, 0, 1);
583 int btrfs_end_transaction_throttle(struct btrfs_trans_handle
*trans
,
584 struct btrfs_root
*root
)
588 ret
= __btrfs_end_transaction(trans
, root
, 1, 1);
594 int btrfs_end_transaction_nolock(struct btrfs_trans_handle
*trans
,
595 struct btrfs_root
*root
)
599 ret
= __btrfs_end_transaction(trans
, root
, 0, 0);
605 int btrfs_end_transaction_dmeta(struct btrfs_trans_handle
*trans
,
606 struct btrfs_root
*root
)
608 return __btrfs_end_transaction(trans
, root
, 1, 1);
612 * when btree blocks are allocated, they have some corresponding bits set for
613 * them in one of two extent_io trees. This is used to make sure all of
614 * those extents are sent to disk but does not wait on them
616 int btrfs_write_marked_extents(struct btrfs_root
*root
,
617 struct extent_io_tree
*dirty_pages
, int mark
)
621 struct address_space
*mapping
= root
->fs_info
->btree_inode
->i_mapping
;
625 while (!find_first_extent_bit(dirty_pages
, start
, &start
, &end
,
627 convert_extent_bit(dirty_pages
, start
, end
, EXTENT_NEED_WAIT
, mark
,
629 err
= filemap_fdatawrite_range(mapping
, start
, end
);
641 * when btree blocks are allocated, they have some corresponding bits set for
642 * them in one of two extent_io trees. This is used to make sure all of
643 * those extents are on disk for transaction or log commit. We wait
644 * on all the pages and clear them from the dirty pages state tree
646 int btrfs_wait_marked_extents(struct btrfs_root
*root
,
647 struct extent_io_tree
*dirty_pages
, int mark
)
651 struct address_space
*mapping
= root
->fs_info
->btree_inode
->i_mapping
;
655 while (!find_first_extent_bit(dirty_pages
, start
, &start
, &end
,
657 clear_extent_bits(dirty_pages
, start
, end
, EXTENT_NEED_WAIT
, GFP_NOFS
);
658 err
= filemap_fdatawait_range(mapping
, start
, end
);
670 * when btree blocks are allocated, they have some corresponding bits set for
671 * them in one of two extent_io trees. This is used to make sure all of
672 * those extents are on disk for transaction or log commit
674 int btrfs_write_and_wait_marked_extents(struct btrfs_root
*root
,
675 struct extent_io_tree
*dirty_pages
, int mark
)
680 ret
= btrfs_write_marked_extents(root
, dirty_pages
, mark
);
681 ret2
= btrfs_wait_marked_extents(root
, dirty_pages
, mark
);
690 int btrfs_write_and_wait_transaction(struct btrfs_trans_handle
*trans
,
691 struct btrfs_root
*root
)
693 if (!trans
|| !trans
->transaction
) {
694 struct inode
*btree_inode
;
695 btree_inode
= root
->fs_info
->btree_inode
;
696 return filemap_write_and_wait(btree_inode
->i_mapping
);
698 return btrfs_write_and_wait_marked_extents(root
,
699 &trans
->transaction
->dirty_pages
,
704 * this is used to update the root pointer in the tree of tree roots.
706 * But, in the case of the extent allocation tree, updating the root
707 * pointer may allocate blocks which may change the root of the extent
710 * So, this loops and repeats and makes sure the cowonly root didn't
711 * change while the root pointer was being updated in the metadata.
713 static int update_cowonly_root(struct btrfs_trans_handle
*trans
,
714 struct btrfs_root
*root
)
719 struct btrfs_root
*tree_root
= root
->fs_info
->tree_root
;
721 old_root_used
= btrfs_root_used(&root
->root_item
);
722 btrfs_write_dirty_block_groups(trans
, root
);
725 old_root_bytenr
= btrfs_root_bytenr(&root
->root_item
);
726 if (old_root_bytenr
== root
->node
->start
&&
727 old_root_used
== btrfs_root_used(&root
->root_item
))
730 btrfs_set_root_node(&root
->root_item
, root
->node
);
731 ret
= btrfs_update_root(trans
, tree_root
,
737 old_root_used
= btrfs_root_used(&root
->root_item
);
738 ret
= btrfs_write_dirty_block_groups(trans
, root
);
743 if (root
!= root
->fs_info
->extent_root
)
744 switch_commit_root(root
);
750 * update all the cowonly tree roots on disk
752 * The error handling in this function may not be obvious. Any of the
753 * failures will cause the file system to go offline. We still need
754 * to clean up the delayed refs.
756 static noinline
int commit_cowonly_roots(struct btrfs_trans_handle
*trans
,
757 struct btrfs_root
*root
)
759 struct btrfs_fs_info
*fs_info
= root
->fs_info
;
760 struct list_head
*next
;
761 struct extent_buffer
*eb
;
764 ret
= btrfs_run_delayed_refs(trans
, root
, (unsigned long)-1);
768 eb
= btrfs_lock_root_node(fs_info
->tree_root
);
769 ret
= btrfs_cow_block(trans
, fs_info
->tree_root
, eb
, NULL
,
771 btrfs_tree_unlock(eb
);
772 free_extent_buffer(eb
);
777 ret
= btrfs_run_delayed_refs(trans
, root
, (unsigned long)-1);
781 ret
= btrfs_run_dev_stats(trans
, root
->fs_info
);
784 while (!list_empty(&fs_info
->dirty_cowonly_roots
)) {
785 next
= fs_info
->dirty_cowonly_roots
.next
;
787 root
= list_entry(next
, struct btrfs_root
, dirty_list
);
789 ret
= update_cowonly_root(trans
, root
);
794 down_write(&fs_info
->extent_commit_sem
);
795 switch_commit_root(fs_info
->extent_root
);
796 up_write(&fs_info
->extent_commit_sem
);
802 * dead roots are old snapshots that need to be deleted. This allocates
803 * a dirty root struct and adds it into the list of dead roots that need to
806 int btrfs_add_dead_root(struct btrfs_root
*root
)
808 spin_lock(&root
->fs_info
->trans_lock
);
809 list_add(&root
->root_list
, &root
->fs_info
->dead_roots
);
810 spin_unlock(&root
->fs_info
->trans_lock
);
815 * update all the cowonly tree roots on disk
817 static noinline
int commit_fs_roots(struct btrfs_trans_handle
*trans
,
818 struct btrfs_root
*root
)
820 struct btrfs_root
*gang
[8];
821 struct btrfs_fs_info
*fs_info
= root
->fs_info
;
826 spin_lock(&fs_info
->fs_roots_radix_lock
);
828 ret
= radix_tree_gang_lookup_tag(&fs_info
->fs_roots_radix
,
831 BTRFS_ROOT_TRANS_TAG
);
834 for (i
= 0; i
< ret
; i
++) {
836 radix_tree_tag_clear(&fs_info
->fs_roots_radix
,
837 (unsigned long)root
->root_key
.objectid
,
838 BTRFS_ROOT_TRANS_TAG
);
839 spin_unlock(&fs_info
->fs_roots_radix_lock
);
841 btrfs_free_log(trans
, root
);
842 btrfs_update_reloc_root(trans
, root
);
843 btrfs_orphan_commit_root(trans
, root
);
845 btrfs_save_ino_cache(root
, trans
);
847 /* see comments in should_cow_block() */
851 if (root
->commit_root
!= root
->node
) {
852 mutex_lock(&root
->fs_commit_mutex
);
853 switch_commit_root(root
);
854 btrfs_unpin_free_ino(root
);
855 mutex_unlock(&root
->fs_commit_mutex
);
857 btrfs_set_root_node(&root
->root_item
,
861 err
= btrfs_update_root(trans
, fs_info
->tree_root
,
864 spin_lock(&fs_info
->fs_roots_radix_lock
);
869 spin_unlock(&fs_info
->fs_roots_radix_lock
);
874 * defrag a given btree. If cacheonly == 1, this won't read from the disk,
875 * otherwise every leaf in the btree is read and defragged.
877 int btrfs_defrag_root(struct btrfs_root
*root
, int cacheonly
)
879 struct btrfs_fs_info
*info
= root
->fs_info
;
880 struct btrfs_trans_handle
*trans
;
884 if (xchg(&root
->defrag_running
, 1))
888 trans
= btrfs_start_transaction(root
, 0);
890 return PTR_ERR(trans
);
892 ret
= btrfs_defrag_leaves(trans
, root
, cacheonly
);
894 nr
= trans
->blocks_used
;
895 btrfs_end_transaction(trans
, root
);
896 btrfs_btree_balance_dirty(info
->tree_root
, nr
);
899 if (btrfs_fs_closing(root
->fs_info
) || ret
!= -EAGAIN
)
902 root
->defrag_running
= 0;
907 * new snapshots need to be created at a very specific time in the
908 * transaction commit. This does the actual creation
910 static noinline
int create_pending_snapshot(struct btrfs_trans_handle
*trans
,
911 struct btrfs_fs_info
*fs_info
,
912 struct btrfs_pending_snapshot
*pending
)
914 struct btrfs_key key
;
915 struct btrfs_root_item
*new_root_item
;
916 struct btrfs_root
*tree_root
= fs_info
->tree_root
;
917 struct btrfs_root
*root
= pending
->root
;
918 struct btrfs_root
*parent_root
;
919 struct btrfs_block_rsv
*rsv
;
920 struct inode
*parent_inode
;
921 struct dentry
*parent
;
922 struct dentry
*dentry
;
923 struct extent_buffer
*tmp
;
924 struct extent_buffer
*old
;
931 rsv
= trans
->block_rsv
;
933 new_root_item
= kmalloc(sizeof(*new_root_item
), GFP_NOFS
);
934 if (!new_root_item
) {
935 ret
= pending
->error
= -ENOMEM
;
939 ret
= btrfs_find_free_objectid(tree_root
, &objectid
);
941 pending
->error
= ret
;
945 btrfs_reloc_pre_snapshot(trans
, pending
, &to_reserve
);
947 if (to_reserve
> 0) {
948 ret
= btrfs_block_rsv_add_noflush(root
, &pending
->block_rsv
,
951 pending
->error
= ret
;
956 key
.objectid
= objectid
;
957 key
.offset
= (u64
)-1;
958 key
.type
= BTRFS_ROOT_ITEM_KEY
;
960 trans
->block_rsv
= &pending
->block_rsv
;
962 dentry
= pending
->dentry
;
963 parent
= dget_parent(dentry
);
964 parent_inode
= parent
->d_inode
;
965 parent_root
= BTRFS_I(parent_inode
)->root
;
966 record_root_in_trans(trans
, parent_root
);
969 * insert the directory item
971 ret
= btrfs_set_inode_index(parent_inode
, &index
);
972 BUG_ON(ret
); /* -ENOMEM */
973 ret
= btrfs_insert_dir_item(trans
, parent_root
,
974 dentry
->d_name
.name
, dentry
->d_name
.len
,
976 BTRFS_FT_DIR
, index
);
977 if (ret
== -EEXIST
) {
978 pending
->error
= -EEXIST
;
982 goto abort_trans_dput
;
985 btrfs_i_size_write(parent_inode
, parent_inode
->i_size
+
986 dentry
->d_name
.len
* 2);
987 ret
= btrfs_update_inode(trans
, parent_root
, parent_inode
);
989 goto abort_trans_dput
;
992 * pull in the delayed directory update
993 * and the delayed inode item
994 * otherwise we corrupt the FS during
997 ret
= btrfs_run_delayed_items(trans
, root
);
998 if (ret
) { /* Transaction aborted */
1003 record_root_in_trans(trans
, root
);
1004 btrfs_set_root_last_snapshot(&root
->root_item
, trans
->transid
);
1005 memcpy(new_root_item
, &root
->root_item
, sizeof(*new_root_item
));
1006 btrfs_check_and_init_root_item(new_root_item
);
1008 root_flags
= btrfs_root_flags(new_root_item
);
1009 if (pending
->readonly
)
1010 root_flags
|= BTRFS_ROOT_SUBVOL_RDONLY
;
1012 root_flags
&= ~BTRFS_ROOT_SUBVOL_RDONLY
;
1013 btrfs_set_root_flags(new_root_item
, root_flags
);
1015 old
= btrfs_lock_root_node(root
);
1016 ret
= btrfs_cow_block(trans
, root
, old
, NULL
, 0, &old
);
1018 btrfs_tree_unlock(old
);
1019 free_extent_buffer(old
);
1020 goto abort_trans_dput
;
1023 btrfs_set_lock_blocking(old
);
1025 ret
= btrfs_copy_root(trans
, root
, old
, &tmp
, objectid
);
1026 /* clean up in any case */
1027 btrfs_tree_unlock(old
);
1028 free_extent_buffer(old
);
1030 goto abort_trans_dput
;
1032 /* see comments in should_cow_block() */
1033 root
->force_cow
= 1;
1036 btrfs_set_root_node(new_root_item
, tmp
);
1037 /* record when the snapshot was created in key.offset */
1038 key
.offset
= trans
->transid
;
1039 ret
= btrfs_insert_root(trans
, tree_root
, &key
, new_root_item
);
1040 btrfs_tree_unlock(tmp
);
1041 free_extent_buffer(tmp
);
1043 goto abort_trans_dput
;
1046 * insert root back/forward references
1048 ret
= btrfs_add_root_ref(trans
, tree_root
, objectid
,
1049 parent_root
->root_key
.objectid
,
1050 btrfs_ino(parent_inode
), index
,
1051 dentry
->d_name
.name
, dentry
->d_name
.len
);
1056 key
.offset
= (u64
)-1;
1057 pending
->snap
= btrfs_read_fs_root_no_name(root
->fs_info
, &key
);
1058 if (IS_ERR(pending
->snap
)) {
1059 ret
= PTR_ERR(pending
->snap
);
1063 ret
= btrfs_reloc_post_snapshot(trans
, pending
);
1068 kfree(new_root_item
);
1069 trans
->block_rsv
= rsv
;
1070 btrfs_block_rsv_release(root
, &pending
->block_rsv
, (u64
)-1);
1076 btrfs_abort_transaction(trans
, root
, ret
);
1081 * create all the snapshots we've scheduled for creation
1083 static noinline
int create_pending_snapshots(struct btrfs_trans_handle
*trans
,
1084 struct btrfs_fs_info
*fs_info
)
1086 struct btrfs_pending_snapshot
*pending
;
1087 struct list_head
*head
= &trans
->transaction
->pending_snapshots
;
1089 list_for_each_entry(pending
, head
, list
)
1090 create_pending_snapshot(trans
, fs_info
, pending
);
1094 static void update_super_roots(struct btrfs_root
*root
)
1096 struct btrfs_root_item
*root_item
;
1097 struct btrfs_super_block
*super
;
1099 super
= root
->fs_info
->super_copy
;
1101 root_item
= &root
->fs_info
->chunk_root
->root_item
;
1102 super
->chunk_root
= root_item
->bytenr
;
1103 super
->chunk_root_generation
= root_item
->generation
;
1104 super
->chunk_root_level
= root_item
->level
;
1106 root_item
= &root
->fs_info
->tree_root
->root_item
;
1107 super
->root
= root_item
->bytenr
;
1108 super
->generation
= root_item
->generation
;
1109 super
->root_level
= root_item
->level
;
1110 if (btrfs_test_opt(root
, SPACE_CACHE
))
1111 super
->cache_generation
= root_item
->generation
;
1114 int btrfs_transaction_in_commit(struct btrfs_fs_info
*info
)
1117 spin_lock(&info
->trans_lock
);
1118 if (info
->running_transaction
)
1119 ret
= info
->running_transaction
->in_commit
;
1120 spin_unlock(&info
->trans_lock
);
1124 int btrfs_transaction_blocked(struct btrfs_fs_info
*info
)
1127 spin_lock(&info
->trans_lock
);
1128 if (info
->running_transaction
)
1129 ret
= info
->running_transaction
->blocked
;
1130 spin_unlock(&info
->trans_lock
);
1135 * wait for the current transaction commit to start and block subsequent
1138 static void wait_current_trans_commit_start(struct btrfs_root
*root
,
1139 struct btrfs_transaction
*trans
)
1141 wait_event(root
->fs_info
->transaction_blocked_wait
, trans
->in_commit
);
1145 * wait for the current transaction to start and then become unblocked.
1148 static void wait_current_trans_commit_start_and_unblock(struct btrfs_root
*root
,
1149 struct btrfs_transaction
*trans
)
1151 wait_event(root
->fs_info
->transaction_wait
,
1152 trans
->commit_done
|| (trans
->in_commit
&& !trans
->blocked
));
1156 * commit transactions asynchronously. once btrfs_commit_transaction_async
1157 * returns, any subsequent transaction will not be allowed to join.
1159 struct btrfs_async_commit
{
1160 struct btrfs_trans_handle
*newtrans
;
1161 struct btrfs_root
*root
;
1162 struct delayed_work work
;
1165 static void do_async_commit(struct work_struct
*work
)
1167 struct btrfs_async_commit
*ac
=
1168 container_of(work
, struct btrfs_async_commit
, work
.work
);
1170 btrfs_commit_transaction(ac
->newtrans
, ac
->root
);
1174 int btrfs_commit_transaction_async(struct btrfs_trans_handle
*trans
,
1175 struct btrfs_root
*root
,
1176 int wait_for_unblock
)
1178 struct btrfs_async_commit
*ac
;
1179 struct btrfs_transaction
*cur_trans
;
1181 ac
= kmalloc(sizeof(*ac
), GFP_NOFS
);
1185 INIT_DELAYED_WORK(&ac
->work
, do_async_commit
);
1187 ac
->newtrans
= btrfs_join_transaction(root
);
1188 if (IS_ERR(ac
->newtrans
)) {
1189 int err
= PTR_ERR(ac
->newtrans
);
1194 /* take transaction reference */
1195 cur_trans
= trans
->transaction
;
1196 atomic_inc(&cur_trans
->use_count
);
1198 btrfs_end_transaction(trans
, root
);
1199 schedule_delayed_work(&ac
->work
, 0);
1201 /* wait for transaction to start and unblock */
1202 if (wait_for_unblock
)
1203 wait_current_trans_commit_start_and_unblock(root
, cur_trans
);
1205 wait_current_trans_commit_start(root
, cur_trans
);
1207 if (current
->journal_info
== trans
)
1208 current
->journal_info
= NULL
;
1210 put_transaction(cur_trans
);
1215 static void cleanup_transaction(struct btrfs_trans_handle
*trans
,
1216 struct btrfs_root
*root
)
1218 struct btrfs_transaction
*cur_trans
= trans
->transaction
;
1220 WARN_ON(trans
->use_count
> 1);
1222 spin_lock(&root
->fs_info
->trans_lock
);
1223 list_del_init(&cur_trans
->list
);
1224 spin_unlock(&root
->fs_info
->trans_lock
);
1226 btrfs_cleanup_one_transaction(trans
->transaction
, root
);
1228 put_transaction(cur_trans
);
1229 put_transaction(cur_trans
);
1231 trace_btrfs_transaction_commit(root
);
1233 btrfs_scrub_continue(root
);
1235 if (current
->journal_info
== trans
)
1236 current
->journal_info
= NULL
;
1238 kmem_cache_free(btrfs_trans_handle_cachep
, trans
);
1242 * btrfs_transaction state sequence:
1243 * in_commit = 0, blocked = 0 (initial)
1244 * in_commit = 1, blocked = 1
1248 int btrfs_commit_transaction(struct btrfs_trans_handle
*trans
,
1249 struct btrfs_root
*root
)
1251 unsigned long joined
= 0;
1252 struct btrfs_transaction
*cur_trans
= trans
->transaction
;
1253 struct btrfs_transaction
*prev_trans
= NULL
;
1256 int should_grow
= 0;
1257 unsigned long now
= get_seconds();
1258 int flush_on_commit
= btrfs_test_opt(root
, FLUSHONCOMMIT
);
1260 btrfs_run_ordered_operations(root
, 0);
1262 btrfs_trans_release_metadata(trans
, root
);
1263 trans
->block_rsv
= NULL
;
1265 if (cur_trans
->aborted
)
1266 goto cleanup_transaction
;
1268 /* make a pass through all the delayed refs we have so far
1269 * any runnings procs may add more while we are here
1271 ret
= btrfs_run_delayed_refs(trans
, root
, 0);
1273 goto cleanup_transaction
;
1275 cur_trans
= trans
->transaction
;
1278 * set the flushing flag so procs in this transaction have to
1279 * start sending their work down.
1281 cur_trans
->delayed_refs
.flushing
= 1;
1283 ret
= btrfs_run_delayed_refs(trans
, root
, 0);
1285 goto cleanup_transaction
;
1287 spin_lock(&cur_trans
->commit_lock
);
1288 if (cur_trans
->in_commit
) {
1289 spin_unlock(&cur_trans
->commit_lock
);
1290 atomic_inc(&cur_trans
->use_count
);
1291 ret
= btrfs_end_transaction(trans
, root
);
1293 wait_for_commit(root
, cur_trans
);
1295 put_transaction(cur_trans
);
1300 trans
->transaction
->in_commit
= 1;
1301 trans
->transaction
->blocked
= 1;
1302 spin_unlock(&cur_trans
->commit_lock
);
1303 wake_up(&root
->fs_info
->transaction_blocked_wait
);
1305 spin_lock(&root
->fs_info
->trans_lock
);
1306 if (cur_trans
->list
.prev
!= &root
->fs_info
->trans_list
) {
1307 prev_trans
= list_entry(cur_trans
->list
.prev
,
1308 struct btrfs_transaction
, list
);
1309 if (!prev_trans
->commit_done
) {
1310 atomic_inc(&prev_trans
->use_count
);
1311 spin_unlock(&root
->fs_info
->trans_lock
);
1313 wait_for_commit(root
, prev_trans
);
1315 put_transaction(prev_trans
);
1317 spin_unlock(&root
->fs_info
->trans_lock
);
1320 spin_unlock(&root
->fs_info
->trans_lock
);
1323 if (now
< cur_trans
->start_time
|| now
- cur_trans
->start_time
< 1)
1327 int snap_pending
= 0;
1329 joined
= cur_trans
->num_joined
;
1330 if (!list_empty(&trans
->transaction
->pending_snapshots
))
1333 WARN_ON(cur_trans
!= trans
->transaction
);
1335 if (flush_on_commit
|| snap_pending
) {
1336 btrfs_start_delalloc_inodes(root
, 1);
1337 btrfs_wait_ordered_extents(root
, 0, 1);
1340 ret
= btrfs_run_delayed_items(trans
, root
);
1342 goto cleanup_transaction
;
1345 * rename don't use btrfs_join_transaction, so, once we
1346 * set the transaction to blocked above, we aren't going
1347 * to get any new ordered operations. We can safely run
1348 * it here and no for sure that nothing new will be added
1351 btrfs_run_ordered_operations(root
, 1);
1353 prepare_to_wait(&cur_trans
->writer_wait
, &wait
,
1354 TASK_UNINTERRUPTIBLE
);
1356 if (atomic_read(&cur_trans
->num_writers
) > 1)
1357 schedule_timeout(MAX_SCHEDULE_TIMEOUT
);
1358 else if (should_grow
)
1359 schedule_timeout(1);
1361 finish_wait(&cur_trans
->writer_wait
, &wait
);
1362 } while (atomic_read(&cur_trans
->num_writers
) > 1 ||
1363 (should_grow
&& cur_trans
->num_joined
!= joined
));
1366 * Ok now we need to make sure to block out any other joins while we
1367 * commit the transaction. We could have started a join before setting
1368 * no_join so make sure to wait for num_writers to == 1 again.
1370 spin_lock(&root
->fs_info
->trans_lock
);
1371 root
->fs_info
->trans_no_join
= 1;
1372 spin_unlock(&root
->fs_info
->trans_lock
);
1373 wait_event(cur_trans
->writer_wait
,
1374 atomic_read(&cur_trans
->num_writers
) == 1);
1377 * the reloc mutex makes sure that we stop
1378 * the balancing code from coming in and moving
1379 * extents around in the middle of the commit
1381 mutex_lock(&root
->fs_info
->reloc_mutex
);
1383 ret
= btrfs_run_delayed_items(trans
, root
);
1385 mutex_unlock(&root
->fs_info
->reloc_mutex
);
1386 goto cleanup_transaction
;
1389 ret
= create_pending_snapshots(trans
, root
->fs_info
);
1391 mutex_unlock(&root
->fs_info
->reloc_mutex
);
1392 goto cleanup_transaction
;
1395 ret
= btrfs_run_delayed_refs(trans
, root
, (unsigned long)-1);
1397 mutex_unlock(&root
->fs_info
->reloc_mutex
);
1398 goto cleanup_transaction
;
1402 * make sure none of the code above managed to slip in a
1405 btrfs_assert_delayed_root_empty(root
);
1407 WARN_ON(cur_trans
!= trans
->transaction
);
1409 btrfs_scrub_pause(root
);
1410 /* btrfs_commit_tree_roots is responsible for getting the
1411 * various roots consistent with each other. Every pointer
1412 * in the tree of tree roots has to point to the most up to date
1413 * root for every subvolume and other tree. So, we have to keep
1414 * the tree logging code from jumping in and changing any
1417 * At this point in the commit, there can't be any tree-log
1418 * writers, but a little lower down we drop the trans mutex
1419 * and let new people in. By holding the tree_log_mutex
1420 * from now until after the super is written, we avoid races
1421 * with the tree-log code.
1423 mutex_lock(&root
->fs_info
->tree_log_mutex
);
1425 ret
= commit_fs_roots(trans
, root
);
1427 mutex_unlock(&root
->fs_info
->tree_log_mutex
);
1428 mutex_unlock(&root
->fs_info
->reloc_mutex
);
1429 goto cleanup_transaction
;
1432 /* commit_fs_roots gets rid of all the tree log roots, it is now
1433 * safe to free the root of tree log roots
1435 btrfs_free_log_root_tree(trans
, root
->fs_info
);
1437 ret
= commit_cowonly_roots(trans
, root
);
1439 mutex_unlock(&root
->fs_info
->tree_log_mutex
);
1440 mutex_unlock(&root
->fs_info
->reloc_mutex
);
1441 goto cleanup_transaction
;
1444 btrfs_prepare_extent_commit(trans
, root
);
1446 cur_trans
= root
->fs_info
->running_transaction
;
1448 btrfs_set_root_node(&root
->fs_info
->tree_root
->root_item
,
1449 root
->fs_info
->tree_root
->node
);
1450 switch_commit_root(root
->fs_info
->tree_root
);
1452 btrfs_set_root_node(&root
->fs_info
->chunk_root
->root_item
,
1453 root
->fs_info
->chunk_root
->node
);
1454 switch_commit_root(root
->fs_info
->chunk_root
);
1456 update_super_roots(root
);
1458 if (!root
->fs_info
->log_root_recovering
) {
1459 btrfs_set_super_log_root(root
->fs_info
->super_copy
, 0);
1460 btrfs_set_super_log_root_level(root
->fs_info
->super_copy
, 0);
1463 memcpy(root
->fs_info
->super_for_commit
, root
->fs_info
->super_copy
,
1464 sizeof(*root
->fs_info
->super_copy
));
1466 trans
->transaction
->blocked
= 0;
1467 spin_lock(&root
->fs_info
->trans_lock
);
1468 root
->fs_info
->running_transaction
= NULL
;
1469 root
->fs_info
->trans_no_join
= 0;
1470 spin_unlock(&root
->fs_info
->trans_lock
);
1471 mutex_unlock(&root
->fs_info
->reloc_mutex
);
1473 wake_up(&root
->fs_info
->transaction_wait
);
1475 ret
= btrfs_write_and_wait_transaction(trans
, root
);
1477 btrfs_error(root
->fs_info
, ret
,
1478 "Error while writing out transaction.");
1479 mutex_unlock(&root
->fs_info
->tree_log_mutex
);
1480 goto cleanup_transaction
;
1483 ret
= write_ctree_super(trans
, root
, 0);
1485 mutex_unlock(&root
->fs_info
->tree_log_mutex
);
1486 goto cleanup_transaction
;
1490 * the super is written, we can safely allow the tree-loggers
1491 * to go about their business
1493 mutex_unlock(&root
->fs_info
->tree_log_mutex
);
1495 btrfs_finish_extent_commit(trans
, root
);
1497 cur_trans
->commit_done
= 1;
1499 root
->fs_info
->last_trans_committed
= cur_trans
->transid
;
1501 wake_up(&cur_trans
->commit_wait
);
1503 spin_lock(&root
->fs_info
->trans_lock
);
1504 list_del_init(&cur_trans
->list
);
1505 spin_unlock(&root
->fs_info
->trans_lock
);
1507 put_transaction(cur_trans
);
1508 put_transaction(cur_trans
);
1510 trace_btrfs_transaction_commit(root
);
1512 btrfs_scrub_continue(root
);
1514 if (current
->journal_info
== trans
)
1515 current
->journal_info
= NULL
;
1517 kmem_cache_free(btrfs_trans_handle_cachep
, trans
);
1519 if (current
!= root
->fs_info
->transaction_kthread
)
1520 btrfs_run_delayed_iputs(root
);
1524 cleanup_transaction
:
1525 btrfs_printk(root
->fs_info
, "Skipping commit of aborted transaction.\n");
1527 if (current
->journal_info
== trans
)
1528 current
->journal_info
= NULL
;
1529 cleanup_transaction(trans
, root
);
1535 * interface function to delete all the snapshots we have scheduled for deletion
1537 int btrfs_clean_old_snapshots(struct btrfs_root
*root
)
1540 struct btrfs_fs_info
*fs_info
= root
->fs_info
;
1542 spin_lock(&fs_info
->trans_lock
);
1543 list_splice_init(&fs_info
->dead_roots
, &list
);
1544 spin_unlock(&fs_info
->trans_lock
);
1546 while (!list_empty(&list
)) {
1549 root
= list_entry(list
.next
, struct btrfs_root
, root_list
);
1550 list_del(&root
->root_list
);
1552 btrfs_kill_all_delayed_nodes(root
);
1554 if (btrfs_header_backref_rev(root
->node
) <
1555 BTRFS_MIXED_BACKREF_REV
)
1556 ret
= btrfs_drop_snapshot(root
, NULL
, 0, 0);
1558 ret
=btrfs_drop_snapshot(root
, NULL
, 1, 0);