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
;
103 } else if (fs_info
->fs_state
& BTRFS_SUPER_FLAG_ERROR
) {
104 spin_unlock(&fs_info
->trans_lock
);
105 kmem_cache_free(btrfs_transaction_cachep
, cur_trans
);
109 atomic_set(&cur_trans
->num_writers
, 1);
110 cur_trans
->num_joined
= 0;
111 init_waitqueue_head(&cur_trans
->writer_wait
);
112 init_waitqueue_head(&cur_trans
->commit_wait
);
113 cur_trans
->in_commit
= 0;
114 cur_trans
->blocked
= 0;
116 * One for this trans handle, one so it will live on until we
117 * commit the transaction.
119 atomic_set(&cur_trans
->use_count
, 2);
120 cur_trans
->commit_done
= 0;
121 cur_trans
->start_time
= get_seconds();
123 cur_trans
->delayed_refs
.root
= RB_ROOT
;
124 cur_trans
->delayed_refs
.num_entries
= 0;
125 cur_trans
->delayed_refs
.num_heads_ready
= 0;
126 cur_trans
->delayed_refs
.num_heads
= 0;
127 cur_trans
->delayed_refs
.flushing
= 0;
128 cur_trans
->delayed_refs
.run_delayed_start
= 0;
129 cur_trans
->delayed_refs
.seq
= 1;
132 * although the tree mod log is per file system and not per transaction,
133 * the log must never go across transaction boundaries.
136 if (!list_empty(&fs_info
->tree_mod_seq_list
)) {
137 printk(KERN_ERR
"btrfs: tree_mod_seq_list not empty when "
138 "creating a fresh transaction\n");
141 if (!RB_EMPTY_ROOT(&fs_info
->tree_mod_log
)) {
142 printk(KERN_ERR
"btrfs: tree_mod_log rb tree not empty when "
143 "creating a fresh transaction\n");
146 atomic_set(&fs_info
->tree_mod_seq
, 0);
148 init_waitqueue_head(&cur_trans
->delayed_refs
.seq_wait
);
149 spin_lock_init(&cur_trans
->commit_lock
);
150 spin_lock_init(&cur_trans
->delayed_refs
.lock
);
151 INIT_LIST_HEAD(&cur_trans
->delayed_refs
.seq_head
);
153 INIT_LIST_HEAD(&cur_trans
->pending_snapshots
);
154 list_add_tail(&cur_trans
->list
, &fs_info
->trans_list
);
155 extent_io_tree_init(&cur_trans
->dirty_pages
,
156 fs_info
->btree_inode
->i_mapping
);
157 fs_info
->generation
++;
158 cur_trans
->transid
= fs_info
->generation
;
159 fs_info
->running_transaction
= cur_trans
;
160 cur_trans
->aborted
= 0;
161 spin_unlock(&fs_info
->trans_lock
);
167 * this does all the record keeping required to make sure that a reference
168 * counted root is properly recorded in a given transaction. This is required
169 * to make sure the old root from before we joined the transaction is deleted
170 * when the transaction commits
172 static int record_root_in_trans(struct btrfs_trans_handle
*trans
,
173 struct btrfs_root
*root
)
175 if (root
->ref_cows
&& root
->last_trans
< trans
->transid
) {
176 WARN_ON(root
== root
->fs_info
->extent_root
);
177 WARN_ON(root
->commit_root
!= root
->node
);
180 * see below for in_trans_setup usage rules
181 * we have the reloc mutex held now, so there
182 * is only one writer in this function
184 root
->in_trans_setup
= 1;
186 /* make sure readers find in_trans_setup before
187 * they find our root->last_trans update
191 spin_lock(&root
->fs_info
->fs_roots_radix_lock
);
192 if (root
->last_trans
== trans
->transid
) {
193 spin_unlock(&root
->fs_info
->fs_roots_radix_lock
);
196 radix_tree_tag_set(&root
->fs_info
->fs_roots_radix
,
197 (unsigned long)root
->root_key
.objectid
,
198 BTRFS_ROOT_TRANS_TAG
);
199 spin_unlock(&root
->fs_info
->fs_roots_radix_lock
);
200 root
->last_trans
= trans
->transid
;
202 /* this is pretty tricky. We don't want to
203 * take the relocation lock in btrfs_record_root_in_trans
204 * unless we're really doing the first setup for this root in
207 * Normally we'd use root->last_trans as a flag to decide
208 * if we want to take the expensive mutex.
210 * But, we have to set root->last_trans before we
211 * init the relocation root, otherwise, we trip over warnings
212 * in ctree.c. The solution used here is to flag ourselves
213 * with root->in_trans_setup. When this is 1, we're still
214 * fixing up the reloc trees and everyone must wait.
216 * When this is zero, they can trust root->last_trans and fly
217 * through btrfs_record_root_in_trans without having to take the
218 * lock. smp_wmb() makes sure that all the writes above are
219 * done before we pop in the zero below
221 btrfs_init_reloc_root(trans
, root
);
223 root
->in_trans_setup
= 0;
229 int btrfs_record_root_in_trans(struct btrfs_trans_handle
*trans
,
230 struct btrfs_root
*root
)
236 * see record_root_in_trans for comments about in_trans_setup usage
240 if (root
->last_trans
== trans
->transid
&&
241 !root
->in_trans_setup
)
244 mutex_lock(&root
->fs_info
->reloc_mutex
);
245 record_root_in_trans(trans
, root
);
246 mutex_unlock(&root
->fs_info
->reloc_mutex
);
251 /* wait for commit against the current transaction to become unblocked
252 * when this is done, it is safe to start a new transaction, but the current
253 * transaction might not be fully on disk.
255 static void wait_current_trans(struct btrfs_root
*root
)
257 struct btrfs_transaction
*cur_trans
;
259 spin_lock(&root
->fs_info
->trans_lock
);
260 cur_trans
= root
->fs_info
->running_transaction
;
261 if (cur_trans
&& cur_trans
->blocked
) {
262 atomic_inc(&cur_trans
->use_count
);
263 spin_unlock(&root
->fs_info
->trans_lock
);
265 wait_event(root
->fs_info
->transaction_wait
,
266 !cur_trans
->blocked
);
267 put_transaction(cur_trans
);
269 spin_unlock(&root
->fs_info
->trans_lock
);
273 enum btrfs_trans_type
{
280 static int may_wait_transaction(struct btrfs_root
*root
, int type
)
282 if (root
->fs_info
->log_root_recovering
)
285 if (type
== TRANS_USERSPACE
)
288 if (type
== TRANS_START
&&
289 !atomic_read(&root
->fs_info
->open_ioctl_trans
))
295 static struct btrfs_trans_handle
*start_transaction(struct btrfs_root
*root
,
296 u64 num_items
, int type
)
298 struct btrfs_trans_handle
*h
;
299 struct btrfs_transaction
*cur_trans
;
303 if (root
->fs_info
->fs_state
& BTRFS_SUPER_FLAG_ERROR
)
304 return ERR_PTR(-EROFS
);
306 if (current
->journal_info
) {
307 WARN_ON(type
!= TRANS_JOIN
&& type
!= TRANS_JOIN_NOLOCK
);
308 h
= current
->journal_info
;
310 h
->orig_rsv
= h
->block_rsv
;
316 * Do the reservation before we join the transaction so we can do all
317 * the appropriate flushing if need be.
319 if (num_items
> 0 && root
!= root
->fs_info
->chunk_root
) {
320 num_bytes
= btrfs_calc_trans_metadata_size(root
, num_items
);
321 ret
= btrfs_block_rsv_add(root
,
322 &root
->fs_info
->trans_block_rsv
,
328 h
= kmem_cache_alloc(btrfs_trans_handle_cachep
, GFP_NOFS
);
330 return ERR_PTR(-ENOMEM
);
332 if (may_wait_transaction(root
, type
))
333 wait_current_trans(root
);
336 ret
= join_transaction(root
, type
== TRANS_JOIN_NOLOCK
);
338 wait_current_trans(root
);
339 } while (ret
== -EBUSY
);
342 kmem_cache_free(btrfs_trans_handle_cachep
, h
);
346 cur_trans
= root
->fs_info
->running_transaction
;
348 h
->transid
= cur_trans
->transid
;
349 h
->transaction
= cur_trans
;
351 h
->bytes_reserved
= 0;
352 h
->delayed_ref_updates
= 0;
360 if (cur_trans
->blocked
&& may_wait_transaction(root
, type
)) {
361 btrfs_commit_transaction(h
, root
);
366 trace_btrfs_space_reservation(root
->fs_info
, "transaction",
367 h
->transid
, num_bytes
, 1);
368 h
->block_rsv
= &root
->fs_info
->trans_block_rsv
;
369 h
->bytes_reserved
= num_bytes
;
373 btrfs_record_root_in_trans(h
, root
);
375 if (!current
->journal_info
&& type
!= TRANS_USERSPACE
)
376 current
->journal_info
= h
;
380 struct btrfs_trans_handle
*btrfs_start_transaction(struct btrfs_root
*root
,
383 return start_transaction(root
, num_items
, TRANS_START
);
385 struct btrfs_trans_handle
*btrfs_join_transaction(struct btrfs_root
*root
)
387 return start_transaction(root
, 0, TRANS_JOIN
);
390 struct btrfs_trans_handle
*btrfs_join_transaction_nolock(struct btrfs_root
*root
)
392 return start_transaction(root
, 0, TRANS_JOIN_NOLOCK
);
395 struct btrfs_trans_handle
*btrfs_start_ioctl_transaction(struct btrfs_root
*root
)
397 return start_transaction(root
, 0, TRANS_USERSPACE
);
400 /* wait for a transaction commit to be fully complete */
401 static noinline
void wait_for_commit(struct btrfs_root
*root
,
402 struct btrfs_transaction
*commit
)
404 wait_event(commit
->commit_wait
, commit
->commit_done
);
407 int btrfs_wait_for_commit(struct btrfs_root
*root
, u64 transid
)
409 struct btrfs_transaction
*cur_trans
= NULL
, *t
;
414 if (transid
<= root
->fs_info
->last_trans_committed
)
417 /* find specified transaction */
418 spin_lock(&root
->fs_info
->trans_lock
);
419 list_for_each_entry(t
, &root
->fs_info
->trans_list
, list
) {
420 if (t
->transid
== transid
) {
422 atomic_inc(&cur_trans
->use_count
);
425 if (t
->transid
> transid
)
428 spin_unlock(&root
->fs_info
->trans_lock
);
431 goto out
; /* bad transid */
433 /* find newest transaction that is committing | committed */
434 spin_lock(&root
->fs_info
->trans_lock
);
435 list_for_each_entry_reverse(t
, &root
->fs_info
->trans_list
,
441 atomic_inc(&cur_trans
->use_count
);
445 spin_unlock(&root
->fs_info
->trans_lock
);
447 goto out
; /* nothing committing|committed */
450 wait_for_commit(root
, cur_trans
);
452 put_transaction(cur_trans
);
458 void btrfs_throttle(struct btrfs_root
*root
)
460 if (!atomic_read(&root
->fs_info
->open_ioctl_trans
))
461 wait_current_trans(root
);
464 static int should_end_transaction(struct btrfs_trans_handle
*trans
,
465 struct btrfs_root
*root
)
469 ret
= btrfs_block_rsv_check(root
, &root
->fs_info
->global_block_rsv
, 5);
473 int btrfs_should_end_transaction(struct btrfs_trans_handle
*trans
,
474 struct btrfs_root
*root
)
476 struct btrfs_transaction
*cur_trans
= trans
->transaction
;
481 if (cur_trans
->blocked
|| cur_trans
->delayed_refs
.flushing
)
484 updates
= trans
->delayed_ref_updates
;
485 trans
->delayed_ref_updates
= 0;
487 err
= btrfs_run_delayed_refs(trans
, root
, updates
);
488 if (err
) /* Error code will also eval true */
492 return should_end_transaction(trans
, root
);
495 static int __btrfs_end_transaction(struct btrfs_trans_handle
*trans
,
496 struct btrfs_root
*root
, int throttle
, int lock
)
498 struct btrfs_transaction
*cur_trans
= trans
->transaction
;
499 struct btrfs_fs_info
*info
= root
->fs_info
;
503 if (--trans
->use_count
) {
504 trans
->block_rsv
= trans
->orig_rsv
;
509 unsigned long cur
= trans
->delayed_ref_updates
;
510 trans
->delayed_ref_updates
= 0;
512 trans
->transaction
->delayed_refs
.num_heads_ready
> 64) {
513 trans
->delayed_ref_updates
= 0;
514 btrfs_run_delayed_refs(trans
, root
, cur
);
520 btrfs_trans_release_metadata(trans
, root
);
521 trans
->block_rsv
= NULL
;
523 if (lock
&& !atomic_read(&root
->fs_info
->open_ioctl_trans
) &&
524 should_end_transaction(trans
, root
)) {
525 trans
->transaction
->blocked
= 1;
529 if (lock
&& cur_trans
->blocked
&& !cur_trans
->in_commit
) {
532 * We may race with somebody else here so end up having
533 * to call end_transaction on ourselves again, so inc
537 return btrfs_commit_transaction(trans
, root
);
539 wake_up_process(info
->transaction_kthread
);
543 WARN_ON(cur_trans
!= info
->running_transaction
);
544 WARN_ON(atomic_read(&cur_trans
->num_writers
) < 1);
545 atomic_dec(&cur_trans
->num_writers
);
548 if (waitqueue_active(&cur_trans
->writer_wait
))
549 wake_up(&cur_trans
->writer_wait
);
550 put_transaction(cur_trans
);
552 if (current
->journal_info
== trans
)
553 current
->journal_info
= NULL
;
556 btrfs_run_delayed_iputs(root
);
558 if (trans
->aborted
||
559 root
->fs_info
->fs_state
& BTRFS_SUPER_FLAG_ERROR
) {
563 memset(trans
, 0, sizeof(*trans
));
564 kmem_cache_free(btrfs_trans_handle_cachep
, trans
);
568 int btrfs_end_transaction(struct btrfs_trans_handle
*trans
,
569 struct btrfs_root
*root
)
573 ret
= __btrfs_end_transaction(trans
, root
, 0, 1);
579 int btrfs_end_transaction_throttle(struct btrfs_trans_handle
*trans
,
580 struct btrfs_root
*root
)
584 ret
= __btrfs_end_transaction(trans
, root
, 1, 1);
590 int btrfs_end_transaction_nolock(struct btrfs_trans_handle
*trans
,
591 struct btrfs_root
*root
)
595 ret
= __btrfs_end_transaction(trans
, root
, 0, 0);
601 int btrfs_end_transaction_dmeta(struct btrfs_trans_handle
*trans
,
602 struct btrfs_root
*root
)
604 return __btrfs_end_transaction(trans
, root
, 1, 1);
608 * when btree blocks are allocated, they have some corresponding bits set for
609 * them in one of two extent_io trees. This is used to make sure all of
610 * those extents are sent to disk but does not wait on them
612 int btrfs_write_marked_extents(struct btrfs_root
*root
,
613 struct extent_io_tree
*dirty_pages
, int mark
)
617 struct address_space
*mapping
= root
->fs_info
->btree_inode
->i_mapping
;
621 while (!find_first_extent_bit(dirty_pages
, start
, &start
, &end
,
623 convert_extent_bit(dirty_pages
, start
, end
, EXTENT_NEED_WAIT
, mark
,
625 err
= filemap_fdatawrite_range(mapping
, start
, end
);
637 * when btree blocks are allocated, they have some corresponding bits set for
638 * them in one of two extent_io trees. This is used to make sure all of
639 * those extents are on disk for transaction or log commit. We wait
640 * on all the pages and clear them from the dirty pages state tree
642 int btrfs_wait_marked_extents(struct btrfs_root
*root
,
643 struct extent_io_tree
*dirty_pages
, int mark
)
647 struct address_space
*mapping
= root
->fs_info
->btree_inode
->i_mapping
;
651 while (!find_first_extent_bit(dirty_pages
, start
, &start
, &end
,
653 clear_extent_bits(dirty_pages
, start
, end
, EXTENT_NEED_WAIT
, GFP_NOFS
);
654 err
= filemap_fdatawait_range(mapping
, start
, end
);
666 * when btree blocks are allocated, they have some corresponding bits set for
667 * them in one of two extent_io trees. This is used to make sure all of
668 * those extents are on disk for transaction or log commit
670 int btrfs_write_and_wait_marked_extents(struct btrfs_root
*root
,
671 struct extent_io_tree
*dirty_pages
, int mark
)
676 ret
= btrfs_write_marked_extents(root
, dirty_pages
, mark
);
677 ret2
= btrfs_wait_marked_extents(root
, dirty_pages
, mark
);
686 int btrfs_write_and_wait_transaction(struct btrfs_trans_handle
*trans
,
687 struct btrfs_root
*root
)
689 if (!trans
|| !trans
->transaction
) {
690 struct inode
*btree_inode
;
691 btree_inode
= root
->fs_info
->btree_inode
;
692 return filemap_write_and_wait(btree_inode
->i_mapping
);
694 return btrfs_write_and_wait_marked_extents(root
,
695 &trans
->transaction
->dirty_pages
,
700 * this is used to update the root pointer in the tree of tree roots.
702 * But, in the case of the extent allocation tree, updating the root
703 * pointer may allocate blocks which may change the root of the extent
706 * So, this loops and repeats and makes sure the cowonly root didn't
707 * change while the root pointer was being updated in the metadata.
709 static int update_cowonly_root(struct btrfs_trans_handle
*trans
,
710 struct btrfs_root
*root
)
715 struct btrfs_root
*tree_root
= root
->fs_info
->tree_root
;
717 old_root_used
= btrfs_root_used(&root
->root_item
);
718 btrfs_write_dirty_block_groups(trans
, root
);
721 old_root_bytenr
= btrfs_root_bytenr(&root
->root_item
);
722 if (old_root_bytenr
== root
->node
->start
&&
723 old_root_used
== btrfs_root_used(&root
->root_item
))
726 btrfs_set_root_node(&root
->root_item
, root
->node
);
727 ret
= btrfs_update_root(trans
, tree_root
,
733 old_root_used
= btrfs_root_used(&root
->root_item
);
734 ret
= btrfs_write_dirty_block_groups(trans
, root
);
739 if (root
!= root
->fs_info
->extent_root
)
740 switch_commit_root(root
);
746 * update all the cowonly tree roots on disk
748 * The error handling in this function may not be obvious. Any of the
749 * failures will cause the file system to go offline. We still need
750 * to clean up the delayed refs.
752 static noinline
int commit_cowonly_roots(struct btrfs_trans_handle
*trans
,
753 struct btrfs_root
*root
)
755 struct btrfs_fs_info
*fs_info
= root
->fs_info
;
756 struct list_head
*next
;
757 struct extent_buffer
*eb
;
760 ret
= btrfs_run_delayed_refs(trans
, root
, (unsigned long)-1);
764 eb
= btrfs_lock_root_node(fs_info
->tree_root
);
765 ret
= btrfs_cow_block(trans
, fs_info
->tree_root
, eb
, NULL
,
767 btrfs_tree_unlock(eb
);
768 free_extent_buffer(eb
);
773 ret
= btrfs_run_delayed_refs(trans
, root
, (unsigned long)-1);
777 ret
= btrfs_run_dev_stats(trans
, root
->fs_info
);
780 while (!list_empty(&fs_info
->dirty_cowonly_roots
)) {
781 next
= fs_info
->dirty_cowonly_roots
.next
;
783 root
= list_entry(next
, struct btrfs_root
, dirty_list
);
785 ret
= update_cowonly_root(trans
, root
);
790 down_write(&fs_info
->extent_commit_sem
);
791 switch_commit_root(fs_info
->extent_root
);
792 up_write(&fs_info
->extent_commit_sem
);
798 * dead roots are old snapshots that need to be deleted. This allocates
799 * a dirty root struct and adds it into the list of dead roots that need to
802 int btrfs_add_dead_root(struct btrfs_root
*root
)
804 spin_lock(&root
->fs_info
->trans_lock
);
805 list_add(&root
->root_list
, &root
->fs_info
->dead_roots
);
806 spin_unlock(&root
->fs_info
->trans_lock
);
811 * update all the cowonly tree roots on disk
813 static noinline
int commit_fs_roots(struct btrfs_trans_handle
*trans
,
814 struct btrfs_root
*root
)
816 struct btrfs_root
*gang
[8];
817 struct btrfs_fs_info
*fs_info
= root
->fs_info
;
822 spin_lock(&fs_info
->fs_roots_radix_lock
);
824 ret
= radix_tree_gang_lookup_tag(&fs_info
->fs_roots_radix
,
827 BTRFS_ROOT_TRANS_TAG
);
830 for (i
= 0; i
< ret
; i
++) {
832 radix_tree_tag_clear(&fs_info
->fs_roots_radix
,
833 (unsigned long)root
->root_key
.objectid
,
834 BTRFS_ROOT_TRANS_TAG
);
835 spin_unlock(&fs_info
->fs_roots_radix_lock
);
837 btrfs_free_log(trans
, root
);
838 btrfs_update_reloc_root(trans
, root
);
839 btrfs_orphan_commit_root(trans
, root
);
841 btrfs_save_ino_cache(root
, trans
);
843 /* see comments in should_cow_block() */
847 if (root
->commit_root
!= root
->node
) {
848 mutex_lock(&root
->fs_commit_mutex
);
849 switch_commit_root(root
);
850 btrfs_unpin_free_ino(root
);
851 mutex_unlock(&root
->fs_commit_mutex
);
853 btrfs_set_root_node(&root
->root_item
,
857 err
= btrfs_update_root(trans
, fs_info
->tree_root
,
860 spin_lock(&fs_info
->fs_roots_radix_lock
);
865 spin_unlock(&fs_info
->fs_roots_radix_lock
);
870 * defrag a given btree. If cacheonly == 1, this won't read from the disk,
871 * otherwise every leaf in the btree is read and defragged.
873 int btrfs_defrag_root(struct btrfs_root
*root
, int cacheonly
)
875 struct btrfs_fs_info
*info
= root
->fs_info
;
876 struct btrfs_trans_handle
*trans
;
880 if (xchg(&root
->defrag_running
, 1))
884 trans
= btrfs_start_transaction(root
, 0);
886 return PTR_ERR(trans
);
888 ret
= btrfs_defrag_leaves(trans
, root
, cacheonly
);
890 nr
= trans
->blocks_used
;
891 btrfs_end_transaction(trans
, root
);
892 btrfs_btree_balance_dirty(info
->tree_root
, nr
);
895 if (btrfs_fs_closing(root
->fs_info
) || ret
!= -EAGAIN
)
898 root
->defrag_running
= 0;
903 * new snapshots need to be created at a very specific time in the
904 * transaction commit. This does the actual creation
906 static noinline
int create_pending_snapshot(struct btrfs_trans_handle
*trans
,
907 struct btrfs_fs_info
*fs_info
,
908 struct btrfs_pending_snapshot
*pending
)
910 struct btrfs_key key
;
911 struct btrfs_root_item
*new_root_item
;
912 struct btrfs_root
*tree_root
= fs_info
->tree_root
;
913 struct btrfs_root
*root
= pending
->root
;
914 struct btrfs_root
*parent_root
;
915 struct btrfs_block_rsv
*rsv
;
916 struct inode
*parent_inode
;
917 struct dentry
*parent
;
918 struct dentry
*dentry
;
919 struct extent_buffer
*tmp
;
920 struct extent_buffer
*old
;
927 rsv
= trans
->block_rsv
;
929 new_root_item
= kmalloc(sizeof(*new_root_item
), GFP_NOFS
);
930 if (!new_root_item
) {
931 ret
= pending
->error
= -ENOMEM
;
935 ret
= btrfs_find_free_objectid(tree_root
, &objectid
);
937 pending
->error
= ret
;
941 btrfs_reloc_pre_snapshot(trans
, pending
, &to_reserve
);
943 if (to_reserve
> 0) {
944 ret
= btrfs_block_rsv_add_noflush(root
, &pending
->block_rsv
,
947 pending
->error
= ret
;
952 key
.objectid
= objectid
;
953 key
.offset
= (u64
)-1;
954 key
.type
= BTRFS_ROOT_ITEM_KEY
;
956 trans
->block_rsv
= &pending
->block_rsv
;
958 dentry
= pending
->dentry
;
959 parent
= dget_parent(dentry
);
960 parent_inode
= parent
->d_inode
;
961 parent_root
= BTRFS_I(parent_inode
)->root
;
962 record_root_in_trans(trans
, parent_root
);
965 * insert the directory item
967 ret
= btrfs_set_inode_index(parent_inode
, &index
);
968 BUG_ON(ret
); /* -ENOMEM */
969 ret
= btrfs_insert_dir_item(trans
, parent_root
,
970 dentry
->d_name
.name
, dentry
->d_name
.len
,
972 BTRFS_FT_DIR
, index
);
973 if (ret
== -EEXIST
) {
974 pending
->error
= -EEXIST
;
978 goto abort_trans_dput
;
981 btrfs_i_size_write(parent_inode
, parent_inode
->i_size
+
982 dentry
->d_name
.len
* 2);
983 ret
= btrfs_update_inode(trans
, parent_root
, parent_inode
);
985 goto abort_trans_dput
;
988 * pull in the delayed directory update
989 * and the delayed inode item
990 * otherwise we corrupt the FS during
993 ret
= btrfs_run_delayed_items(trans
, root
);
994 if (ret
) { /* Transaction aborted */
999 record_root_in_trans(trans
, root
);
1000 btrfs_set_root_last_snapshot(&root
->root_item
, trans
->transid
);
1001 memcpy(new_root_item
, &root
->root_item
, sizeof(*new_root_item
));
1002 btrfs_check_and_init_root_item(new_root_item
);
1004 root_flags
= btrfs_root_flags(new_root_item
);
1005 if (pending
->readonly
)
1006 root_flags
|= BTRFS_ROOT_SUBVOL_RDONLY
;
1008 root_flags
&= ~BTRFS_ROOT_SUBVOL_RDONLY
;
1009 btrfs_set_root_flags(new_root_item
, root_flags
);
1011 old
= btrfs_lock_root_node(root
);
1012 ret
= btrfs_cow_block(trans
, root
, old
, NULL
, 0, &old
);
1014 btrfs_tree_unlock(old
);
1015 free_extent_buffer(old
);
1016 goto abort_trans_dput
;
1019 btrfs_set_lock_blocking(old
);
1021 ret
= btrfs_copy_root(trans
, root
, old
, &tmp
, objectid
);
1022 /* clean up in any case */
1023 btrfs_tree_unlock(old
);
1024 free_extent_buffer(old
);
1026 goto abort_trans_dput
;
1028 /* see comments in should_cow_block() */
1029 root
->force_cow
= 1;
1032 btrfs_set_root_node(new_root_item
, tmp
);
1033 /* record when the snapshot was created in key.offset */
1034 key
.offset
= trans
->transid
;
1035 ret
= btrfs_insert_root(trans
, tree_root
, &key
, new_root_item
);
1036 btrfs_tree_unlock(tmp
);
1037 free_extent_buffer(tmp
);
1039 goto abort_trans_dput
;
1042 * insert root back/forward references
1044 ret
= btrfs_add_root_ref(trans
, tree_root
, objectid
,
1045 parent_root
->root_key
.objectid
,
1046 btrfs_ino(parent_inode
), index
,
1047 dentry
->d_name
.name
, dentry
->d_name
.len
);
1052 key
.offset
= (u64
)-1;
1053 pending
->snap
= btrfs_read_fs_root_no_name(root
->fs_info
, &key
);
1054 if (IS_ERR(pending
->snap
)) {
1055 ret
= PTR_ERR(pending
->snap
);
1059 ret
= btrfs_reloc_post_snapshot(trans
, pending
);
1064 kfree(new_root_item
);
1065 trans
->block_rsv
= rsv
;
1066 btrfs_block_rsv_release(root
, &pending
->block_rsv
, (u64
)-1);
1072 btrfs_abort_transaction(trans
, root
, ret
);
1077 * create all the snapshots we've scheduled for creation
1079 static noinline
int create_pending_snapshots(struct btrfs_trans_handle
*trans
,
1080 struct btrfs_fs_info
*fs_info
)
1082 struct btrfs_pending_snapshot
*pending
;
1083 struct list_head
*head
= &trans
->transaction
->pending_snapshots
;
1085 list_for_each_entry(pending
, head
, list
)
1086 create_pending_snapshot(trans
, fs_info
, pending
);
1090 static void update_super_roots(struct btrfs_root
*root
)
1092 struct btrfs_root_item
*root_item
;
1093 struct btrfs_super_block
*super
;
1095 super
= root
->fs_info
->super_copy
;
1097 root_item
= &root
->fs_info
->chunk_root
->root_item
;
1098 super
->chunk_root
= root_item
->bytenr
;
1099 super
->chunk_root_generation
= root_item
->generation
;
1100 super
->chunk_root_level
= root_item
->level
;
1102 root_item
= &root
->fs_info
->tree_root
->root_item
;
1103 super
->root
= root_item
->bytenr
;
1104 super
->generation
= root_item
->generation
;
1105 super
->root_level
= root_item
->level
;
1106 if (btrfs_test_opt(root
, SPACE_CACHE
))
1107 super
->cache_generation
= root_item
->generation
;
1110 int btrfs_transaction_in_commit(struct btrfs_fs_info
*info
)
1113 spin_lock(&info
->trans_lock
);
1114 if (info
->running_transaction
)
1115 ret
= info
->running_transaction
->in_commit
;
1116 spin_unlock(&info
->trans_lock
);
1120 int btrfs_transaction_blocked(struct btrfs_fs_info
*info
)
1123 spin_lock(&info
->trans_lock
);
1124 if (info
->running_transaction
)
1125 ret
= info
->running_transaction
->blocked
;
1126 spin_unlock(&info
->trans_lock
);
1131 * wait for the current transaction commit to start and block subsequent
1134 static void wait_current_trans_commit_start(struct btrfs_root
*root
,
1135 struct btrfs_transaction
*trans
)
1137 wait_event(root
->fs_info
->transaction_blocked_wait
, trans
->in_commit
);
1141 * wait for the current transaction to start and then become unblocked.
1144 static void wait_current_trans_commit_start_and_unblock(struct btrfs_root
*root
,
1145 struct btrfs_transaction
*trans
)
1147 wait_event(root
->fs_info
->transaction_wait
,
1148 trans
->commit_done
|| (trans
->in_commit
&& !trans
->blocked
));
1152 * commit transactions asynchronously. once btrfs_commit_transaction_async
1153 * returns, any subsequent transaction will not be allowed to join.
1155 struct btrfs_async_commit
{
1156 struct btrfs_trans_handle
*newtrans
;
1157 struct btrfs_root
*root
;
1158 struct delayed_work work
;
1161 static void do_async_commit(struct work_struct
*work
)
1163 struct btrfs_async_commit
*ac
=
1164 container_of(work
, struct btrfs_async_commit
, work
.work
);
1166 btrfs_commit_transaction(ac
->newtrans
, ac
->root
);
1170 int btrfs_commit_transaction_async(struct btrfs_trans_handle
*trans
,
1171 struct btrfs_root
*root
,
1172 int wait_for_unblock
)
1174 struct btrfs_async_commit
*ac
;
1175 struct btrfs_transaction
*cur_trans
;
1177 ac
= kmalloc(sizeof(*ac
), GFP_NOFS
);
1181 INIT_DELAYED_WORK(&ac
->work
, do_async_commit
);
1183 ac
->newtrans
= btrfs_join_transaction(root
);
1184 if (IS_ERR(ac
->newtrans
)) {
1185 int err
= PTR_ERR(ac
->newtrans
);
1190 /* take transaction reference */
1191 cur_trans
= trans
->transaction
;
1192 atomic_inc(&cur_trans
->use_count
);
1194 btrfs_end_transaction(trans
, root
);
1195 schedule_delayed_work(&ac
->work
, 0);
1197 /* wait for transaction to start and unblock */
1198 if (wait_for_unblock
)
1199 wait_current_trans_commit_start_and_unblock(root
, cur_trans
);
1201 wait_current_trans_commit_start(root
, cur_trans
);
1203 if (current
->journal_info
== trans
)
1204 current
->journal_info
= NULL
;
1206 put_transaction(cur_trans
);
1211 static void cleanup_transaction(struct btrfs_trans_handle
*trans
,
1212 struct btrfs_root
*root
, int err
)
1214 struct btrfs_transaction
*cur_trans
= trans
->transaction
;
1216 WARN_ON(trans
->use_count
> 1);
1218 btrfs_abort_transaction(trans
, root
, err
);
1220 spin_lock(&root
->fs_info
->trans_lock
);
1221 list_del_init(&cur_trans
->list
);
1222 if (cur_trans
== root
->fs_info
->running_transaction
) {
1223 root
->fs_info
->running_transaction
= NULL
;
1224 root
->fs_info
->trans_no_join
= 0;
1226 spin_unlock(&root
->fs_info
->trans_lock
);
1228 btrfs_cleanup_one_transaction(trans
->transaction
, root
);
1230 put_transaction(cur_trans
);
1231 put_transaction(cur_trans
);
1233 trace_btrfs_transaction_commit(root
);
1235 btrfs_scrub_continue(root
);
1237 if (current
->journal_info
== trans
)
1238 current
->journal_info
= NULL
;
1240 kmem_cache_free(btrfs_trans_handle_cachep
, trans
);
1244 * btrfs_transaction state sequence:
1245 * in_commit = 0, blocked = 0 (initial)
1246 * in_commit = 1, blocked = 1
1250 int btrfs_commit_transaction(struct btrfs_trans_handle
*trans
,
1251 struct btrfs_root
*root
)
1253 unsigned long joined
= 0;
1254 struct btrfs_transaction
*cur_trans
= trans
->transaction
;
1255 struct btrfs_transaction
*prev_trans
= NULL
;
1258 int should_grow
= 0;
1259 unsigned long now
= get_seconds();
1260 int flush_on_commit
= btrfs_test_opt(root
, FLUSHONCOMMIT
);
1262 btrfs_run_ordered_operations(root
, 0);
1264 if (cur_trans
->aborted
)
1265 goto cleanup_transaction
;
1267 /* make a pass through all the delayed refs we have so far
1268 * any runnings procs may add more while we are here
1270 ret
= btrfs_run_delayed_refs(trans
, root
, 0);
1272 goto cleanup_transaction
;
1274 btrfs_trans_release_metadata(trans
, root
);
1275 trans
->block_rsv
= NULL
;
1277 cur_trans
= trans
->transaction
;
1280 * set the flushing flag so procs in this transaction have to
1281 * start sending their work down.
1283 cur_trans
->delayed_refs
.flushing
= 1;
1285 ret
= btrfs_run_delayed_refs(trans
, root
, 0);
1287 goto cleanup_transaction
;
1289 spin_lock(&cur_trans
->commit_lock
);
1290 if (cur_trans
->in_commit
) {
1291 spin_unlock(&cur_trans
->commit_lock
);
1292 atomic_inc(&cur_trans
->use_count
);
1293 ret
= btrfs_end_transaction(trans
, root
);
1295 wait_for_commit(root
, cur_trans
);
1297 put_transaction(cur_trans
);
1302 trans
->transaction
->in_commit
= 1;
1303 trans
->transaction
->blocked
= 1;
1304 spin_unlock(&cur_trans
->commit_lock
);
1305 wake_up(&root
->fs_info
->transaction_blocked_wait
);
1307 spin_lock(&root
->fs_info
->trans_lock
);
1308 if (cur_trans
->list
.prev
!= &root
->fs_info
->trans_list
) {
1309 prev_trans
= list_entry(cur_trans
->list
.prev
,
1310 struct btrfs_transaction
, list
);
1311 if (!prev_trans
->commit_done
) {
1312 atomic_inc(&prev_trans
->use_count
);
1313 spin_unlock(&root
->fs_info
->trans_lock
);
1315 wait_for_commit(root
, prev_trans
);
1317 put_transaction(prev_trans
);
1319 spin_unlock(&root
->fs_info
->trans_lock
);
1322 spin_unlock(&root
->fs_info
->trans_lock
);
1325 if (!btrfs_test_opt(root
, SSD
) &&
1326 (now
< cur_trans
->start_time
|| now
- cur_trans
->start_time
< 1))
1330 int snap_pending
= 0;
1332 joined
= cur_trans
->num_joined
;
1333 if (!list_empty(&trans
->transaction
->pending_snapshots
))
1336 WARN_ON(cur_trans
!= trans
->transaction
);
1338 if (flush_on_commit
|| snap_pending
) {
1339 btrfs_start_delalloc_inodes(root
, 1);
1340 btrfs_wait_ordered_extents(root
, 0, 1);
1343 ret
= btrfs_run_delayed_items(trans
, root
);
1345 goto cleanup_transaction
;
1348 * rename don't use btrfs_join_transaction, so, once we
1349 * set the transaction to blocked above, we aren't going
1350 * to get any new ordered operations. We can safely run
1351 * it here and no for sure that nothing new will be added
1354 btrfs_run_ordered_operations(root
, 1);
1356 prepare_to_wait(&cur_trans
->writer_wait
, &wait
,
1357 TASK_UNINTERRUPTIBLE
);
1359 if (atomic_read(&cur_trans
->num_writers
) > 1)
1360 schedule_timeout(MAX_SCHEDULE_TIMEOUT
);
1361 else if (should_grow
)
1362 schedule_timeout(1);
1364 finish_wait(&cur_trans
->writer_wait
, &wait
);
1365 } while (atomic_read(&cur_trans
->num_writers
) > 1 ||
1366 (should_grow
&& cur_trans
->num_joined
!= joined
));
1369 * Ok now we need to make sure to block out any other joins while we
1370 * commit the transaction. We could have started a join before setting
1371 * no_join so make sure to wait for num_writers to == 1 again.
1373 spin_lock(&root
->fs_info
->trans_lock
);
1374 root
->fs_info
->trans_no_join
= 1;
1375 spin_unlock(&root
->fs_info
->trans_lock
);
1376 wait_event(cur_trans
->writer_wait
,
1377 atomic_read(&cur_trans
->num_writers
) == 1);
1380 * the reloc mutex makes sure that we stop
1381 * the balancing code from coming in and moving
1382 * extents around in the middle of the commit
1384 mutex_lock(&root
->fs_info
->reloc_mutex
);
1386 ret
= btrfs_run_delayed_items(trans
, root
);
1388 mutex_unlock(&root
->fs_info
->reloc_mutex
);
1389 goto cleanup_transaction
;
1392 ret
= create_pending_snapshots(trans
, root
->fs_info
);
1394 mutex_unlock(&root
->fs_info
->reloc_mutex
);
1395 goto cleanup_transaction
;
1398 ret
= btrfs_run_delayed_refs(trans
, root
, (unsigned long)-1);
1400 mutex_unlock(&root
->fs_info
->reloc_mutex
);
1401 goto cleanup_transaction
;
1405 * make sure none of the code above managed to slip in a
1408 btrfs_assert_delayed_root_empty(root
);
1410 WARN_ON(cur_trans
!= trans
->transaction
);
1412 btrfs_scrub_pause(root
);
1413 /* btrfs_commit_tree_roots is responsible for getting the
1414 * various roots consistent with each other. Every pointer
1415 * in the tree of tree roots has to point to the most up to date
1416 * root for every subvolume and other tree. So, we have to keep
1417 * the tree logging code from jumping in and changing any
1420 * At this point in the commit, there can't be any tree-log
1421 * writers, but a little lower down we drop the trans mutex
1422 * and let new people in. By holding the tree_log_mutex
1423 * from now until after the super is written, we avoid races
1424 * with the tree-log code.
1426 mutex_lock(&root
->fs_info
->tree_log_mutex
);
1428 ret
= commit_fs_roots(trans
, root
);
1430 mutex_unlock(&root
->fs_info
->tree_log_mutex
);
1431 mutex_unlock(&root
->fs_info
->reloc_mutex
);
1432 goto cleanup_transaction
;
1435 /* commit_fs_roots gets rid of all the tree log roots, it is now
1436 * safe to free the root of tree log roots
1438 btrfs_free_log_root_tree(trans
, root
->fs_info
);
1440 ret
= commit_cowonly_roots(trans
, root
);
1442 mutex_unlock(&root
->fs_info
->tree_log_mutex
);
1443 mutex_unlock(&root
->fs_info
->reloc_mutex
);
1444 goto cleanup_transaction
;
1447 btrfs_prepare_extent_commit(trans
, root
);
1449 cur_trans
= root
->fs_info
->running_transaction
;
1451 btrfs_set_root_node(&root
->fs_info
->tree_root
->root_item
,
1452 root
->fs_info
->tree_root
->node
);
1453 switch_commit_root(root
->fs_info
->tree_root
);
1455 btrfs_set_root_node(&root
->fs_info
->chunk_root
->root_item
,
1456 root
->fs_info
->chunk_root
->node
);
1457 switch_commit_root(root
->fs_info
->chunk_root
);
1459 update_super_roots(root
);
1461 if (!root
->fs_info
->log_root_recovering
) {
1462 btrfs_set_super_log_root(root
->fs_info
->super_copy
, 0);
1463 btrfs_set_super_log_root_level(root
->fs_info
->super_copy
, 0);
1466 memcpy(root
->fs_info
->super_for_commit
, root
->fs_info
->super_copy
,
1467 sizeof(*root
->fs_info
->super_copy
));
1469 trans
->transaction
->blocked
= 0;
1470 spin_lock(&root
->fs_info
->trans_lock
);
1471 root
->fs_info
->running_transaction
= NULL
;
1472 root
->fs_info
->trans_no_join
= 0;
1473 spin_unlock(&root
->fs_info
->trans_lock
);
1474 mutex_unlock(&root
->fs_info
->reloc_mutex
);
1476 wake_up(&root
->fs_info
->transaction_wait
);
1478 ret
= btrfs_write_and_wait_transaction(trans
, root
);
1480 btrfs_error(root
->fs_info
, ret
,
1481 "Error while writing out transaction.");
1482 mutex_unlock(&root
->fs_info
->tree_log_mutex
);
1483 goto cleanup_transaction
;
1486 ret
= write_ctree_super(trans
, root
, 0);
1488 mutex_unlock(&root
->fs_info
->tree_log_mutex
);
1489 goto cleanup_transaction
;
1493 * the super is written, we can safely allow the tree-loggers
1494 * to go about their business
1496 mutex_unlock(&root
->fs_info
->tree_log_mutex
);
1498 btrfs_finish_extent_commit(trans
, root
);
1500 cur_trans
->commit_done
= 1;
1502 root
->fs_info
->last_trans_committed
= cur_trans
->transid
;
1504 wake_up(&cur_trans
->commit_wait
);
1506 spin_lock(&root
->fs_info
->trans_lock
);
1507 list_del_init(&cur_trans
->list
);
1508 spin_unlock(&root
->fs_info
->trans_lock
);
1510 put_transaction(cur_trans
);
1511 put_transaction(cur_trans
);
1513 trace_btrfs_transaction_commit(root
);
1515 btrfs_scrub_continue(root
);
1517 if (current
->journal_info
== trans
)
1518 current
->journal_info
= NULL
;
1520 kmem_cache_free(btrfs_trans_handle_cachep
, trans
);
1522 if (current
!= root
->fs_info
->transaction_kthread
)
1523 btrfs_run_delayed_iputs(root
);
1527 cleanup_transaction
:
1528 btrfs_trans_release_metadata(trans
, root
);
1529 trans
->block_rsv
= NULL
;
1530 btrfs_printk(root
->fs_info
, "Skipping commit of aborted transaction.\n");
1532 if (current
->journal_info
== trans
)
1533 current
->journal_info
= NULL
;
1534 cleanup_transaction(trans
, root
, ret
);
1540 * interface function to delete all the snapshots we have scheduled for deletion
1542 int btrfs_clean_old_snapshots(struct btrfs_root
*root
)
1545 struct btrfs_fs_info
*fs_info
= root
->fs_info
;
1547 spin_lock(&fs_info
->trans_lock
);
1548 list_splice_init(&fs_info
->dead_roots
, &list
);
1549 spin_unlock(&fs_info
->trans_lock
);
1551 while (!list_empty(&list
)) {
1554 root
= list_entry(list
.next
, struct btrfs_root
, root_list
);
1555 list_del(&root
->root_list
);
1557 btrfs_kill_all_delayed_nodes(root
);
1559 if (btrfs_header_backref_rev(root
->node
) <
1560 BTRFS_MIXED_BACKREF_REV
)
1561 ret
= btrfs_drop_snapshot(root
, NULL
, 0, 0);
1563 ret
=btrfs_drop_snapshot(root
, NULL
, 1, 0);