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 memset(transaction
, 0, sizeof(*transaction
));
42 kmem_cache_free(btrfs_transaction_cachep
, transaction
);
46 static noinline
void switch_commit_root(struct btrfs_root
*root
)
48 free_extent_buffer(root
->commit_root
);
49 root
->commit_root
= btrfs_root_node(root
);
53 * either allocate a new transaction or hop into the existing one
55 static noinline
int join_transaction(struct btrfs_root
*root
, int nofail
)
57 struct btrfs_transaction
*cur_trans
;
58 struct btrfs_fs_info
*fs_info
= root
->fs_info
;
60 spin_lock(&fs_info
->trans_lock
);
62 /* The file system has been taken offline. No new transactions. */
63 if (fs_info
->fs_state
& BTRFS_SUPER_FLAG_ERROR
) {
64 spin_unlock(&fs_info
->trans_lock
);
68 if (fs_info
->trans_no_join
) {
70 spin_unlock(&fs_info
->trans_lock
);
75 cur_trans
= fs_info
->running_transaction
;
77 if (cur_trans
->aborted
) {
78 spin_unlock(&fs_info
->trans_lock
);
79 return cur_trans
->aborted
;
81 atomic_inc(&cur_trans
->use_count
);
82 atomic_inc(&cur_trans
->num_writers
);
83 cur_trans
->num_joined
++;
84 spin_unlock(&fs_info
->trans_lock
);
87 spin_unlock(&fs_info
->trans_lock
);
89 cur_trans
= kmem_cache_alloc(btrfs_transaction_cachep
, GFP_NOFS
);
93 spin_lock(&fs_info
->trans_lock
);
94 if (fs_info
->running_transaction
) {
96 * someone started a transaction after we unlocked. Make sure
97 * to redo the trans_no_join checks above
99 kmem_cache_free(btrfs_transaction_cachep
, cur_trans
);
100 cur_trans
= fs_info
->running_transaction
;
102 } else if (root
->fs_info
->fs_state
& BTRFS_SUPER_FLAG_ERROR
) {
103 spin_unlock(&root
->fs_info
->trans_lock
);
104 kmem_cache_free(btrfs_transaction_cachep
, cur_trans
);
108 atomic_set(&cur_trans
->num_writers
, 1);
109 cur_trans
->num_joined
= 0;
110 init_waitqueue_head(&cur_trans
->writer_wait
);
111 init_waitqueue_head(&cur_trans
->commit_wait
);
112 cur_trans
->in_commit
= 0;
113 cur_trans
->blocked
= 0;
115 * One for this trans handle, one so it will live on until we
116 * commit the transaction.
118 atomic_set(&cur_trans
->use_count
, 2);
119 cur_trans
->commit_done
= 0;
120 cur_trans
->start_time
= get_seconds();
122 cur_trans
->delayed_refs
.root
= RB_ROOT
;
123 cur_trans
->delayed_refs
.num_entries
= 0;
124 cur_trans
->delayed_refs
.num_heads_ready
= 0;
125 cur_trans
->delayed_refs
.num_heads
= 0;
126 cur_trans
->delayed_refs
.flushing
= 0;
127 cur_trans
->delayed_refs
.run_delayed_start
= 0;
130 * although the tree mod log is per file system and not per transaction,
131 * the log must never go across transaction boundaries.
134 if (!list_empty(&fs_info
->tree_mod_seq_list
)) {
135 printk(KERN_ERR
"btrfs: tree_mod_seq_list not empty when "
136 "creating a fresh transaction\n");
139 if (!RB_EMPTY_ROOT(&fs_info
->tree_mod_log
)) {
140 printk(KERN_ERR
"btrfs: tree_mod_log rb tree not empty when "
141 "creating a fresh transaction\n");
144 atomic_set(&fs_info
->tree_mod_seq
, 0);
146 spin_lock_init(&cur_trans
->commit_lock
);
147 spin_lock_init(&cur_trans
->delayed_refs
.lock
);
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
;
298 u64 qgroup_reserved
= 0;
300 if (root
->fs_info
->fs_state
& BTRFS_SUPER_FLAG_ERROR
)
301 return ERR_PTR(-EROFS
);
303 if (current
->journal_info
) {
304 WARN_ON(type
!= TRANS_JOIN
&& type
!= TRANS_JOIN_NOLOCK
);
305 h
= current
->journal_info
;
307 h
->orig_rsv
= h
->block_rsv
;
313 * Do the reservation before we join the transaction so we can do all
314 * the appropriate flushing if need be.
316 if (num_items
> 0 && root
!= root
->fs_info
->chunk_root
) {
317 if (root
->fs_info
->quota_enabled
&&
318 is_fstree(root
->root_key
.objectid
)) {
319 qgroup_reserved
= num_items
* root
->leafsize
;
320 ret
= btrfs_qgroup_reserve(root
, qgroup_reserved
);
325 num_bytes
= btrfs_calc_trans_metadata_size(root
, num_items
);
326 ret
= btrfs_block_rsv_add(root
,
327 &root
->fs_info
->trans_block_rsv
,
333 h
= kmem_cache_alloc(btrfs_trans_handle_cachep
, GFP_NOFS
);
335 return ERR_PTR(-ENOMEM
);
337 if (may_wait_transaction(root
, type
))
338 wait_current_trans(root
);
341 ret
= join_transaction(root
, type
== TRANS_JOIN_NOLOCK
);
343 wait_current_trans(root
);
344 } while (ret
== -EBUSY
);
347 kmem_cache_free(btrfs_trans_handle_cachep
, h
);
351 cur_trans
= root
->fs_info
->running_transaction
;
353 h
->transid
= cur_trans
->transid
;
354 h
->transaction
= cur_trans
;
356 h
->bytes_reserved
= 0;
358 h
->delayed_ref_updates
= 0;
363 h
->qgroup_reserved
= qgroup_reserved
;
364 h
->delayed_ref_elem
.seq
= 0;
365 INIT_LIST_HEAD(&h
->qgroup_ref_list
);
368 if (cur_trans
->blocked
&& may_wait_transaction(root
, type
)) {
369 btrfs_commit_transaction(h
, root
);
374 trace_btrfs_space_reservation(root
->fs_info
, "transaction",
375 h
->transid
, num_bytes
, 1);
376 h
->block_rsv
= &root
->fs_info
->trans_block_rsv
;
377 h
->bytes_reserved
= num_bytes
;
381 btrfs_record_root_in_trans(h
, root
);
383 if (!current
->journal_info
&& type
!= TRANS_USERSPACE
)
384 current
->journal_info
= h
;
388 struct btrfs_trans_handle
*btrfs_start_transaction(struct btrfs_root
*root
,
391 return start_transaction(root
, num_items
, TRANS_START
);
393 struct btrfs_trans_handle
*btrfs_join_transaction(struct btrfs_root
*root
)
395 return start_transaction(root
, 0, TRANS_JOIN
);
398 struct btrfs_trans_handle
*btrfs_join_transaction_nolock(struct btrfs_root
*root
)
400 return start_transaction(root
, 0, TRANS_JOIN_NOLOCK
);
403 struct btrfs_trans_handle
*btrfs_start_ioctl_transaction(struct btrfs_root
*root
)
405 return start_transaction(root
, 0, TRANS_USERSPACE
);
408 /* wait for a transaction commit to be fully complete */
409 static noinline
void wait_for_commit(struct btrfs_root
*root
,
410 struct btrfs_transaction
*commit
)
412 wait_event(commit
->commit_wait
, commit
->commit_done
);
415 int btrfs_wait_for_commit(struct btrfs_root
*root
, u64 transid
)
417 struct btrfs_transaction
*cur_trans
= NULL
, *t
;
422 if (transid
<= root
->fs_info
->last_trans_committed
)
425 /* find specified transaction */
426 spin_lock(&root
->fs_info
->trans_lock
);
427 list_for_each_entry(t
, &root
->fs_info
->trans_list
, list
) {
428 if (t
->transid
== transid
) {
430 atomic_inc(&cur_trans
->use_count
);
433 if (t
->transid
> transid
)
436 spin_unlock(&root
->fs_info
->trans_lock
);
439 goto out
; /* bad transid */
441 /* find newest transaction that is committing | committed */
442 spin_lock(&root
->fs_info
->trans_lock
);
443 list_for_each_entry_reverse(t
, &root
->fs_info
->trans_list
,
449 atomic_inc(&cur_trans
->use_count
);
453 spin_unlock(&root
->fs_info
->trans_lock
);
455 goto out
; /* nothing committing|committed */
458 wait_for_commit(root
, cur_trans
);
460 put_transaction(cur_trans
);
466 void btrfs_throttle(struct btrfs_root
*root
)
468 if (!atomic_read(&root
->fs_info
->open_ioctl_trans
))
469 wait_current_trans(root
);
472 static int should_end_transaction(struct btrfs_trans_handle
*trans
,
473 struct btrfs_root
*root
)
477 ret
= btrfs_block_rsv_check(root
, &root
->fs_info
->global_block_rsv
, 5);
481 int btrfs_should_end_transaction(struct btrfs_trans_handle
*trans
,
482 struct btrfs_root
*root
)
484 struct btrfs_transaction
*cur_trans
= trans
->transaction
;
485 struct btrfs_block_rsv
*rsv
= trans
->block_rsv
;
490 if (cur_trans
->blocked
|| cur_trans
->delayed_refs
.flushing
)
494 * We need to do this in case we're deleting csums so the global block
495 * rsv get's used instead of the csum block rsv.
497 trans
->block_rsv
= NULL
;
499 updates
= trans
->delayed_ref_updates
;
500 trans
->delayed_ref_updates
= 0;
502 err
= btrfs_run_delayed_refs(trans
, root
, updates
);
503 if (err
) /* Error code will also eval true */
507 trans
->block_rsv
= rsv
;
509 return should_end_transaction(trans
, root
);
512 static int __btrfs_end_transaction(struct btrfs_trans_handle
*trans
,
513 struct btrfs_root
*root
, int throttle
, int lock
)
515 struct btrfs_transaction
*cur_trans
= trans
->transaction
;
516 struct btrfs_fs_info
*info
= root
->fs_info
;
520 if (--trans
->use_count
) {
521 trans
->block_rsv
= trans
->orig_rsv
;
526 * do the qgroup accounting as early as possible
528 err
= btrfs_delayed_refs_qgroup_accounting(trans
, info
);
530 btrfs_trans_release_metadata(trans
, root
);
531 trans
->block_rsv
= NULL
;
533 * the same root has to be passed to start_transaction and
534 * end_transaction. Subvolume quota depends on this.
536 WARN_ON(trans
->root
!= root
);
538 if (trans
->qgroup_reserved
) {
539 btrfs_qgroup_free(root
, trans
->qgroup_reserved
);
540 trans
->qgroup_reserved
= 0;
544 unsigned long cur
= trans
->delayed_ref_updates
;
545 trans
->delayed_ref_updates
= 0;
547 trans
->transaction
->delayed_refs
.num_heads_ready
> 64) {
548 trans
->delayed_ref_updates
= 0;
549 btrfs_run_delayed_refs(trans
, root
, cur
);
556 if (lock
&& !atomic_read(&root
->fs_info
->open_ioctl_trans
) &&
557 should_end_transaction(trans
, root
)) {
558 trans
->transaction
->blocked
= 1;
562 if (lock
&& cur_trans
->blocked
&& !cur_trans
->in_commit
) {
565 * We may race with somebody else here so end up having
566 * to call end_transaction on ourselves again, so inc
570 return btrfs_commit_transaction(trans
, root
);
572 wake_up_process(info
->transaction_kthread
);
576 WARN_ON(cur_trans
!= info
->running_transaction
);
577 WARN_ON(atomic_read(&cur_trans
->num_writers
) < 1);
578 atomic_dec(&cur_trans
->num_writers
);
581 if (waitqueue_active(&cur_trans
->writer_wait
))
582 wake_up(&cur_trans
->writer_wait
);
583 put_transaction(cur_trans
);
585 if (current
->journal_info
== trans
)
586 current
->journal_info
= NULL
;
589 btrfs_run_delayed_iputs(root
);
591 if (trans
->aborted
||
592 root
->fs_info
->fs_state
& BTRFS_SUPER_FLAG_ERROR
) {
595 assert_qgroups_uptodate(trans
);
597 memset(trans
, 0, sizeof(*trans
));
598 kmem_cache_free(btrfs_trans_handle_cachep
, trans
);
602 int btrfs_end_transaction(struct btrfs_trans_handle
*trans
,
603 struct btrfs_root
*root
)
607 ret
= __btrfs_end_transaction(trans
, root
, 0, 1);
613 int btrfs_end_transaction_throttle(struct btrfs_trans_handle
*trans
,
614 struct btrfs_root
*root
)
618 ret
= __btrfs_end_transaction(trans
, root
, 1, 1);
624 int btrfs_end_transaction_nolock(struct btrfs_trans_handle
*trans
,
625 struct btrfs_root
*root
)
629 ret
= __btrfs_end_transaction(trans
, root
, 0, 0);
635 int btrfs_end_transaction_dmeta(struct btrfs_trans_handle
*trans
,
636 struct btrfs_root
*root
)
638 return __btrfs_end_transaction(trans
, root
, 1, 1);
642 * when btree blocks are allocated, they have some corresponding bits set for
643 * them in one of two extent_io trees. This is used to make sure all of
644 * those extents are sent to disk but does not wait on them
646 int btrfs_write_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 convert_extent_bit(dirty_pages
, start
, end
, EXTENT_NEED_WAIT
, mark
,
659 err
= filemap_fdatawrite_range(mapping
, start
, end
);
671 * when btree blocks are allocated, they have some corresponding bits set for
672 * them in one of two extent_io trees. This is used to make sure all of
673 * those extents are on disk for transaction or log commit. We wait
674 * on all the pages and clear them from the dirty pages state tree
676 int btrfs_wait_marked_extents(struct btrfs_root
*root
,
677 struct extent_io_tree
*dirty_pages
, int mark
)
681 struct address_space
*mapping
= root
->fs_info
->btree_inode
->i_mapping
;
685 while (!find_first_extent_bit(dirty_pages
, start
, &start
, &end
,
687 clear_extent_bits(dirty_pages
, start
, end
, EXTENT_NEED_WAIT
, GFP_NOFS
);
688 err
= filemap_fdatawait_range(mapping
, start
, end
);
700 * when btree blocks are allocated, they have some corresponding bits set for
701 * them in one of two extent_io trees. This is used to make sure all of
702 * those extents are on disk for transaction or log commit
704 int btrfs_write_and_wait_marked_extents(struct btrfs_root
*root
,
705 struct extent_io_tree
*dirty_pages
, int mark
)
710 ret
= btrfs_write_marked_extents(root
, dirty_pages
, mark
);
711 ret2
= btrfs_wait_marked_extents(root
, dirty_pages
, mark
);
720 int btrfs_write_and_wait_transaction(struct btrfs_trans_handle
*trans
,
721 struct btrfs_root
*root
)
723 if (!trans
|| !trans
->transaction
) {
724 struct inode
*btree_inode
;
725 btree_inode
= root
->fs_info
->btree_inode
;
726 return filemap_write_and_wait(btree_inode
->i_mapping
);
728 return btrfs_write_and_wait_marked_extents(root
,
729 &trans
->transaction
->dirty_pages
,
734 * this is used to update the root pointer in the tree of tree roots.
736 * But, in the case of the extent allocation tree, updating the root
737 * pointer may allocate blocks which may change the root of the extent
740 * So, this loops and repeats and makes sure the cowonly root didn't
741 * change while the root pointer was being updated in the metadata.
743 static int update_cowonly_root(struct btrfs_trans_handle
*trans
,
744 struct btrfs_root
*root
)
749 struct btrfs_root
*tree_root
= root
->fs_info
->tree_root
;
751 old_root_used
= btrfs_root_used(&root
->root_item
);
752 btrfs_write_dirty_block_groups(trans
, root
);
755 old_root_bytenr
= btrfs_root_bytenr(&root
->root_item
);
756 if (old_root_bytenr
== root
->node
->start
&&
757 old_root_used
== btrfs_root_used(&root
->root_item
))
760 btrfs_set_root_node(&root
->root_item
, root
->node
);
761 ret
= btrfs_update_root(trans
, tree_root
,
767 old_root_used
= btrfs_root_used(&root
->root_item
);
768 ret
= btrfs_write_dirty_block_groups(trans
, root
);
773 if (root
!= root
->fs_info
->extent_root
)
774 switch_commit_root(root
);
780 * update all the cowonly tree roots on disk
782 * The error handling in this function may not be obvious. Any of the
783 * failures will cause the file system to go offline. We still need
784 * to clean up the delayed refs.
786 static noinline
int commit_cowonly_roots(struct btrfs_trans_handle
*trans
,
787 struct btrfs_root
*root
)
789 struct btrfs_fs_info
*fs_info
= root
->fs_info
;
790 struct list_head
*next
;
791 struct extent_buffer
*eb
;
794 ret
= btrfs_run_delayed_refs(trans
, root
, (unsigned long)-1);
798 eb
= btrfs_lock_root_node(fs_info
->tree_root
);
799 ret
= btrfs_cow_block(trans
, fs_info
->tree_root
, eb
, NULL
,
801 btrfs_tree_unlock(eb
);
802 free_extent_buffer(eb
);
807 ret
= btrfs_run_delayed_refs(trans
, root
, (unsigned long)-1);
811 ret
= btrfs_run_dev_stats(trans
, root
->fs_info
);
814 ret
= btrfs_run_qgroups(trans
, root
->fs_info
);
817 /* run_qgroups might have added some more refs */
818 ret
= btrfs_run_delayed_refs(trans
, root
, (unsigned long)-1);
821 while (!list_empty(&fs_info
->dirty_cowonly_roots
)) {
822 next
= fs_info
->dirty_cowonly_roots
.next
;
824 root
= list_entry(next
, struct btrfs_root
, dirty_list
);
826 ret
= update_cowonly_root(trans
, root
);
831 down_write(&fs_info
->extent_commit_sem
);
832 switch_commit_root(fs_info
->extent_root
);
833 up_write(&fs_info
->extent_commit_sem
);
839 * dead roots are old snapshots that need to be deleted. This allocates
840 * a dirty root struct and adds it into the list of dead roots that need to
843 int btrfs_add_dead_root(struct btrfs_root
*root
)
845 spin_lock(&root
->fs_info
->trans_lock
);
846 list_add(&root
->root_list
, &root
->fs_info
->dead_roots
);
847 spin_unlock(&root
->fs_info
->trans_lock
);
852 * update all the cowonly tree roots on disk
854 static noinline
int commit_fs_roots(struct btrfs_trans_handle
*trans
,
855 struct btrfs_root
*root
)
857 struct btrfs_root
*gang
[8];
858 struct btrfs_fs_info
*fs_info
= root
->fs_info
;
863 spin_lock(&fs_info
->fs_roots_radix_lock
);
865 ret
= radix_tree_gang_lookup_tag(&fs_info
->fs_roots_radix
,
868 BTRFS_ROOT_TRANS_TAG
);
871 for (i
= 0; i
< ret
; i
++) {
873 radix_tree_tag_clear(&fs_info
->fs_roots_radix
,
874 (unsigned long)root
->root_key
.objectid
,
875 BTRFS_ROOT_TRANS_TAG
);
876 spin_unlock(&fs_info
->fs_roots_radix_lock
);
878 btrfs_free_log(trans
, root
);
879 btrfs_update_reloc_root(trans
, root
);
880 btrfs_orphan_commit_root(trans
, root
);
882 btrfs_save_ino_cache(root
, trans
);
884 /* see comments in should_cow_block() */
888 if (root
->commit_root
!= root
->node
) {
889 mutex_lock(&root
->fs_commit_mutex
);
890 switch_commit_root(root
);
891 btrfs_unpin_free_ino(root
);
892 mutex_unlock(&root
->fs_commit_mutex
);
894 btrfs_set_root_node(&root
->root_item
,
898 err
= btrfs_update_root(trans
, fs_info
->tree_root
,
901 spin_lock(&fs_info
->fs_roots_radix_lock
);
906 spin_unlock(&fs_info
->fs_roots_radix_lock
);
911 * defrag a given btree. If cacheonly == 1, this won't read from the disk,
912 * otherwise every leaf in the btree is read and defragged.
914 int btrfs_defrag_root(struct btrfs_root
*root
, int cacheonly
)
916 struct btrfs_fs_info
*info
= root
->fs_info
;
917 struct btrfs_trans_handle
*trans
;
921 if (xchg(&root
->defrag_running
, 1))
925 trans
= btrfs_start_transaction(root
, 0);
927 return PTR_ERR(trans
);
929 ret
= btrfs_defrag_leaves(trans
, root
, cacheonly
);
931 nr
= trans
->blocks_used
;
932 btrfs_end_transaction(trans
, root
);
933 btrfs_btree_balance_dirty(info
->tree_root
, nr
);
936 if (btrfs_fs_closing(root
->fs_info
) || ret
!= -EAGAIN
)
939 root
->defrag_running
= 0;
944 * new snapshots need to be created at a very specific time in the
945 * transaction commit. This does the actual creation
947 static noinline
int create_pending_snapshot(struct btrfs_trans_handle
*trans
,
948 struct btrfs_fs_info
*fs_info
,
949 struct btrfs_pending_snapshot
*pending
)
951 struct btrfs_key key
;
952 struct btrfs_root_item
*new_root_item
;
953 struct btrfs_root
*tree_root
= fs_info
->tree_root
;
954 struct btrfs_root
*root
= pending
->root
;
955 struct btrfs_root
*parent_root
;
956 struct btrfs_block_rsv
*rsv
;
957 struct inode
*parent_inode
;
958 struct dentry
*parent
;
959 struct dentry
*dentry
;
960 struct extent_buffer
*tmp
;
961 struct extent_buffer
*old
;
968 rsv
= trans
->block_rsv
;
970 new_root_item
= kmalloc(sizeof(*new_root_item
), GFP_NOFS
);
971 if (!new_root_item
) {
972 ret
= pending
->error
= -ENOMEM
;
976 ret
= btrfs_find_free_objectid(tree_root
, &objectid
);
978 pending
->error
= ret
;
982 btrfs_reloc_pre_snapshot(trans
, pending
, &to_reserve
);
984 if (to_reserve
> 0) {
985 ret
= btrfs_block_rsv_add_noflush(root
, &pending
->block_rsv
,
988 pending
->error
= ret
;
993 ret
= btrfs_qgroup_inherit(trans
, fs_info
, root
->root_key
.objectid
,
994 objectid
, pending
->inherit
);
995 kfree(pending
->inherit
);
997 pending
->error
= ret
;
1001 key
.objectid
= objectid
;
1002 key
.offset
= (u64
)-1;
1003 key
.type
= BTRFS_ROOT_ITEM_KEY
;
1005 trans
->block_rsv
= &pending
->block_rsv
;
1007 dentry
= pending
->dentry
;
1008 parent
= dget_parent(dentry
);
1009 parent_inode
= parent
->d_inode
;
1010 parent_root
= BTRFS_I(parent_inode
)->root
;
1011 record_root_in_trans(trans
, parent_root
);
1014 * insert the directory item
1016 ret
= btrfs_set_inode_index(parent_inode
, &index
);
1017 BUG_ON(ret
); /* -ENOMEM */
1018 ret
= btrfs_insert_dir_item(trans
, parent_root
,
1019 dentry
->d_name
.name
, dentry
->d_name
.len
,
1021 BTRFS_FT_DIR
, index
);
1022 if (ret
== -EEXIST
) {
1023 pending
->error
= -EEXIST
;
1027 goto abort_trans_dput
;
1030 btrfs_i_size_write(parent_inode
, parent_inode
->i_size
+
1031 dentry
->d_name
.len
* 2);
1032 ret
= btrfs_update_inode(trans
, parent_root
, parent_inode
);
1034 goto abort_trans_dput
;
1037 * pull in the delayed directory update
1038 * and the delayed inode item
1039 * otherwise we corrupt the FS during
1042 ret
= btrfs_run_delayed_items(trans
, root
);
1043 if (ret
) { /* Transaction aborted */
1048 record_root_in_trans(trans
, root
);
1049 btrfs_set_root_last_snapshot(&root
->root_item
, trans
->transid
);
1050 memcpy(new_root_item
, &root
->root_item
, sizeof(*new_root_item
));
1051 btrfs_check_and_init_root_item(new_root_item
);
1053 root_flags
= btrfs_root_flags(new_root_item
);
1054 if (pending
->readonly
)
1055 root_flags
|= BTRFS_ROOT_SUBVOL_RDONLY
;
1057 root_flags
&= ~BTRFS_ROOT_SUBVOL_RDONLY
;
1058 btrfs_set_root_flags(new_root_item
, root_flags
);
1060 old
= btrfs_lock_root_node(root
);
1061 ret
= btrfs_cow_block(trans
, root
, old
, NULL
, 0, &old
);
1063 btrfs_tree_unlock(old
);
1064 free_extent_buffer(old
);
1065 goto abort_trans_dput
;
1068 btrfs_set_lock_blocking(old
);
1070 ret
= btrfs_copy_root(trans
, root
, old
, &tmp
, objectid
);
1071 /* clean up in any case */
1072 btrfs_tree_unlock(old
);
1073 free_extent_buffer(old
);
1075 goto abort_trans_dput
;
1077 /* see comments in should_cow_block() */
1078 root
->force_cow
= 1;
1081 btrfs_set_root_node(new_root_item
, tmp
);
1082 /* record when the snapshot was created in key.offset */
1083 key
.offset
= trans
->transid
;
1084 ret
= btrfs_insert_root(trans
, tree_root
, &key
, new_root_item
);
1085 btrfs_tree_unlock(tmp
);
1086 free_extent_buffer(tmp
);
1088 goto abort_trans_dput
;
1091 * insert root back/forward references
1093 ret
= btrfs_add_root_ref(trans
, tree_root
, objectid
,
1094 parent_root
->root_key
.objectid
,
1095 btrfs_ino(parent_inode
), index
,
1096 dentry
->d_name
.name
, dentry
->d_name
.len
);
1101 key
.offset
= (u64
)-1;
1102 pending
->snap
= btrfs_read_fs_root_no_name(root
->fs_info
, &key
);
1103 if (IS_ERR(pending
->snap
)) {
1104 ret
= PTR_ERR(pending
->snap
);
1108 ret
= btrfs_reloc_post_snapshot(trans
, pending
);
1113 kfree(new_root_item
);
1114 trans
->block_rsv
= rsv
;
1115 btrfs_block_rsv_release(root
, &pending
->block_rsv
, (u64
)-1);
1121 btrfs_abort_transaction(trans
, root
, ret
);
1126 * create all the snapshots we've scheduled for creation
1128 static noinline
int create_pending_snapshots(struct btrfs_trans_handle
*trans
,
1129 struct btrfs_fs_info
*fs_info
)
1131 struct btrfs_pending_snapshot
*pending
;
1132 struct list_head
*head
= &trans
->transaction
->pending_snapshots
;
1134 list_for_each_entry(pending
, head
, list
)
1135 create_pending_snapshot(trans
, fs_info
, pending
);
1139 static void update_super_roots(struct btrfs_root
*root
)
1141 struct btrfs_root_item
*root_item
;
1142 struct btrfs_super_block
*super
;
1144 super
= root
->fs_info
->super_copy
;
1146 root_item
= &root
->fs_info
->chunk_root
->root_item
;
1147 super
->chunk_root
= root_item
->bytenr
;
1148 super
->chunk_root_generation
= root_item
->generation
;
1149 super
->chunk_root_level
= root_item
->level
;
1151 root_item
= &root
->fs_info
->tree_root
->root_item
;
1152 super
->root
= root_item
->bytenr
;
1153 super
->generation
= root_item
->generation
;
1154 super
->root_level
= root_item
->level
;
1155 if (btrfs_test_opt(root
, SPACE_CACHE
))
1156 super
->cache_generation
= root_item
->generation
;
1159 int btrfs_transaction_in_commit(struct btrfs_fs_info
*info
)
1162 spin_lock(&info
->trans_lock
);
1163 if (info
->running_transaction
)
1164 ret
= info
->running_transaction
->in_commit
;
1165 spin_unlock(&info
->trans_lock
);
1169 int btrfs_transaction_blocked(struct btrfs_fs_info
*info
)
1172 spin_lock(&info
->trans_lock
);
1173 if (info
->running_transaction
)
1174 ret
= info
->running_transaction
->blocked
;
1175 spin_unlock(&info
->trans_lock
);
1180 * wait for the current transaction commit to start and block subsequent
1183 static void wait_current_trans_commit_start(struct btrfs_root
*root
,
1184 struct btrfs_transaction
*trans
)
1186 wait_event(root
->fs_info
->transaction_blocked_wait
, trans
->in_commit
);
1190 * wait for the current transaction to start and then become unblocked.
1193 static void wait_current_trans_commit_start_and_unblock(struct btrfs_root
*root
,
1194 struct btrfs_transaction
*trans
)
1196 wait_event(root
->fs_info
->transaction_wait
,
1197 trans
->commit_done
|| (trans
->in_commit
&& !trans
->blocked
));
1201 * commit transactions asynchronously. once btrfs_commit_transaction_async
1202 * returns, any subsequent transaction will not be allowed to join.
1204 struct btrfs_async_commit
{
1205 struct btrfs_trans_handle
*newtrans
;
1206 struct btrfs_root
*root
;
1207 struct delayed_work work
;
1210 static void do_async_commit(struct work_struct
*work
)
1212 struct btrfs_async_commit
*ac
=
1213 container_of(work
, struct btrfs_async_commit
, work
.work
);
1215 btrfs_commit_transaction(ac
->newtrans
, ac
->root
);
1219 int btrfs_commit_transaction_async(struct btrfs_trans_handle
*trans
,
1220 struct btrfs_root
*root
,
1221 int wait_for_unblock
)
1223 struct btrfs_async_commit
*ac
;
1224 struct btrfs_transaction
*cur_trans
;
1226 ac
= kmalloc(sizeof(*ac
), GFP_NOFS
);
1230 INIT_DELAYED_WORK(&ac
->work
, do_async_commit
);
1232 ac
->newtrans
= btrfs_join_transaction(root
);
1233 if (IS_ERR(ac
->newtrans
)) {
1234 int err
= PTR_ERR(ac
->newtrans
);
1239 /* take transaction reference */
1240 cur_trans
= trans
->transaction
;
1241 atomic_inc(&cur_trans
->use_count
);
1243 btrfs_end_transaction(trans
, root
);
1244 schedule_delayed_work(&ac
->work
, 0);
1246 /* wait for transaction to start and unblock */
1247 if (wait_for_unblock
)
1248 wait_current_trans_commit_start_and_unblock(root
, cur_trans
);
1250 wait_current_trans_commit_start(root
, cur_trans
);
1252 if (current
->journal_info
== trans
)
1253 current
->journal_info
= NULL
;
1255 put_transaction(cur_trans
);
1260 static void cleanup_transaction(struct btrfs_trans_handle
*trans
,
1261 struct btrfs_root
*root
, int err
)
1263 struct btrfs_transaction
*cur_trans
= trans
->transaction
;
1265 WARN_ON(trans
->use_count
> 1);
1267 btrfs_abort_transaction(trans
, root
, err
);
1269 spin_lock(&root
->fs_info
->trans_lock
);
1270 list_del_init(&cur_trans
->list
);
1271 if (cur_trans
== root
->fs_info
->running_transaction
) {
1272 root
->fs_info
->running_transaction
= NULL
;
1273 root
->fs_info
->trans_no_join
= 0;
1275 spin_unlock(&root
->fs_info
->trans_lock
);
1277 btrfs_cleanup_one_transaction(trans
->transaction
, root
);
1279 put_transaction(cur_trans
);
1280 put_transaction(cur_trans
);
1282 trace_btrfs_transaction_commit(root
);
1284 btrfs_scrub_continue(root
);
1286 if (current
->journal_info
== trans
)
1287 current
->journal_info
= NULL
;
1289 kmem_cache_free(btrfs_trans_handle_cachep
, trans
);
1293 * btrfs_transaction state sequence:
1294 * in_commit = 0, blocked = 0 (initial)
1295 * in_commit = 1, blocked = 1
1299 int btrfs_commit_transaction(struct btrfs_trans_handle
*trans
,
1300 struct btrfs_root
*root
)
1302 unsigned long joined
= 0;
1303 struct btrfs_transaction
*cur_trans
= trans
->transaction
;
1304 struct btrfs_transaction
*prev_trans
= NULL
;
1307 int should_grow
= 0;
1308 unsigned long now
= get_seconds();
1309 int flush_on_commit
= btrfs_test_opt(root
, FLUSHONCOMMIT
);
1311 btrfs_run_ordered_operations(root
, 0);
1313 btrfs_trans_release_metadata(trans
, root
);
1314 trans
->block_rsv
= NULL
;
1316 if (cur_trans
->aborted
)
1317 goto cleanup_transaction
;
1319 /* make a pass through all the delayed refs we have so far
1320 * any runnings procs may add more while we are here
1322 ret
= btrfs_run_delayed_refs(trans
, root
, 0);
1324 goto cleanup_transaction
;
1326 cur_trans
= trans
->transaction
;
1329 * set the flushing flag so procs in this transaction have to
1330 * start sending their work down.
1332 cur_trans
->delayed_refs
.flushing
= 1;
1334 ret
= btrfs_run_delayed_refs(trans
, root
, 0);
1336 goto cleanup_transaction
;
1338 spin_lock(&cur_trans
->commit_lock
);
1339 if (cur_trans
->in_commit
) {
1340 spin_unlock(&cur_trans
->commit_lock
);
1341 atomic_inc(&cur_trans
->use_count
);
1342 ret
= btrfs_end_transaction(trans
, root
);
1344 wait_for_commit(root
, cur_trans
);
1346 put_transaction(cur_trans
);
1351 trans
->transaction
->in_commit
= 1;
1352 trans
->transaction
->blocked
= 1;
1353 spin_unlock(&cur_trans
->commit_lock
);
1354 wake_up(&root
->fs_info
->transaction_blocked_wait
);
1356 spin_lock(&root
->fs_info
->trans_lock
);
1357 if (cur_trans
->list
.prev
!= &root
->fs_info
->trans_list
) {
1358 prev_trans
= list_entry(cur_trans
->list
.prev
,
1359 struct btrfs_transaction
, list
);
1360 if (!prev_trans
->commit_done
) {
1361 atomic_inc(&prev_trans
->use_count
);
1362 spin_unlock(&root
->fs_info
->trans_lock
);
1364 wait_for_commit(root
, prev_trans
);
1366 put_transaction(prev_trans
);
1368 spin_unlock(&root
->fs_info
->trans_lock
);
1371 spin_unlock(&root
->fs_info
->trans_lock
);
1374 if (now
< cur_trans
->start_time
|| now
- cur_trans
->start_time
< 1)
1378 int snap_pending
= 0;
1380 joined
= cur_trans
->num_joined
;
1381 if (!list_empty(&trans
->transaction
->pending_snapshots
))
1384 WARN_ON(cur_trans
!= trans
->transaction
);
1386 if (flush_on_commit
|| snap_pending
) {
1387 btrfs_start_delalloc_inodes(root
, 1);
1388 btrfs_wait_ordered_extents(root
, 0, 1);
1391 ret
= btrfs_run_delayed_items(trans
, root
);
1393 goto cleanup_transaction
;
1396 * running the delayed items may have added new refs. account
1397 * them now so that they hinder processing of more delayed refs
1398 * as little as possible.
1400 btrfs_delayed_refs_qgroup_accounting(trans
, root
->fs_info
);
1403 * rename don't use btrfs_join_transaction, so, once we
1404 * set the transaction to blocked above, we aren't going
1405 * to get any new ordered operations. We can safely run
1406 * it here and no for sure that nothing new will be added
1409 btrfs_run_ordered_operations(root
, 1);
1411 prepare_to_wait(&cur_trans
->writer_wait
, &wait
,
1412 TASK_UNINTERRUPTIBLE
);
1414 if (atomic_read(&cur_trans
->num_writers
) > 1)
1415 schedule_timeout(MAX_SCHEDULE_TIMEOUT
);
1416 else if (should_grow
)
1417 schedule_timeout(1);
1419 finish_wait(&cur_trans
->writer_wait
, &wait
);
1420 } while (atomic_read(&cur_trans
->num_writers
) > 1 ||
1421 (should_grow
&& cur_trans
->num_joined
!= joined
));
1424 * Ok now we need to make sure to block out any other joins while we
1425 * commit the transaction. We could have started a join before setting
1426 * no_join so make sure to wait for num_writers to == 1 again.
1428 spin_lock(&root
->fs_info
->trans_lock
);
1429 root
->fs_info
->trans_no_join
= 1;
1430 spin_unlock(&root
->fs_info
->trans_lock
);
1431 wait_event(cur_trans
->writer_wait
,
1432 atomic_read(&cur_trans
->num_writers
) == 1);
1435 * the reloc mutex makes sure that we stop
1436 * the balancing code from coming in and moving
1437 * extents around in the middle of the commit
1439 mutex_lock(&root
->fs_info
->reloc_mutex
);
1441 ret
= btrfs_run_delayed_items(trans
, root
);
1443 mutex_unlock(&root
->fs_info
->reloc_mutex
);
1444 goto cleanup_transaction
;
1447 ret
= create_pending_snapshots(trans
, root
->fs_info
);
1449 mutex_unlock(&root
->fs_info
->reloc_mutex
);
1450 goto cleanup_transaction
;
1453 ret
= btrfs_run_delayed_refs(trans
, root
, (unsigned long)-1);
1455 mutex_unlock(&root
->fs_info
->reloc_mutex
);
1456 goto cleanup_transaction
;
1460 * make sure none of the code above managed to slip in a
1463 btrfs_assert_delayed_root_empty(root
);
1465 WARN_ON(cur_trans
!= trans
->transaction
);
1467 btrfs_scrub_pause(root
);
1468 /* btrfs_commit_tree_roots is responsible for getting the
1469 * various roots consistent with each other. Every pointer
1470 * in the tree of tree roots has to point to the most up to date
1471 * root for every subvolume and other tree. So, we have to keep
1472 * the tree logging code from jumping in and changing any
1475 * At this point in the commit, there can't be any tree-log
1476 * writers, but a little lower down we drop the trans mutex
1477 * and let new people in. By holding the tree_log_mutex
1478 * from now until after the super is written, we avoid races
1479 * with the tree-log code.
1481 mutex_lock(&root
->fs_info
->tree_log_mutex
);
1483 ret
= commit_fs_roots(trans
, root
);
1485 mutex_unlock(&root
->fs_info
->tree_log_mutex
);
1486 mutex_unlock(&root
->fs_info
->reloc_mutex
);
1487 goto cleanup_transaction
;
1490 /* commit_fs_roots gets rid of all the tree log roots, it is now
1491 * safe to free the root of tree log roots
1493 btrfs_free_log_root_tree(trans
, root
->fs_info
);
1495 ret
= commit_cowonly_roots(trans
, root
);
1497 mutex_unlock(&root
->fs_info
->tree_log_mutex
);
1498 mutex_unlock(&root
->fs_info
->reloc_mutex
);
1499 goto cleanup_transaction
;
1502 btrfs_prepare_extent_commit(trans
, root
);
1504 cur_trans
= root
->fs_info
->running_transaction
;
1506 btrfs_set_root_node(&root
->fs_info
->tree_root
->root_item
,
1507 root
->fs_info
->tree_root
->node
);
1508 switch_commit_root(root
->fs_info
->tree_root
);
1510 btrfs_set_root_node(&root
->fs_info
->chunk_root
->root_item
,
1511 root
->fs_info
->chunk_root
->node
);
1512 switch_commit_root(root
->fs_info
->chunk_root
);
1514 assert_qgroups_uptodate(trans
);
1515 update_super_roots(root
);
1517 if (!root
->fs_info
->log_root_recovering
) {
1518 btrfs_set_super_log_root(root
->fs_info
->super_copy
, 0);
1519 btrfs_set_super_log_root_level(root
->fs_info
->super_copy
, 0);
1522 memcpy(root
->fs_info
->super_for_commit
, root
->fs_info
->super_copy
,
1523 sizeof(*root
->fs_info
->super_copy
));
1525 trans
->transaction
->blocked
= 0;
1526 spin_lock(&root
->fs_info
->trans_lock
);
1527 root
->fs_info
->running_transaction
= NULL
;
1528 root
->fs_info
->trans_no_join
= 0;
1529 spin_unlock(&root
->fs_info
->trans_lock
);
1530 mutex_unlock(&root
->fs_info
->reloc_mutex
);
1532 wake_up(&root
->fs_info
->transaction_wait
);
1534 ret
= btrfs_write_and_wait_transaction(trans
, root
);
1536 btrfs_error(root
->fs_info
, ret
,
1537 "Error while writing out transaction.");
1538 mutex_unlock(&root
->fs_info
->tree_log_mutex
);
1539 goto cleanup_transaction
;
1542 ret
= write_ctree_super(trans
, root
, 0);
1544 mutex_unlock(&root
->fs_info
->tree_log_mutex
);
1545 goto cleanup_transaction
;
1549 * the super is written, we can safely allow the tree-loggers
1550 * to go about their business
1552 mutex_unlock(&root
->fs_info
->tree_log_mutex
);
1554 btrfs_finish_extent_commit(trans
, root
);
1556 cur_trans
->commit_done
= 1;
1558 root
->fs_info
->last_trans_committed
= cur_trans
->transid
;
1560 wake_up(&cur_trans
->commit_wait
);
1562 spin_lock(&root
->fs_info
->trans_lock
);
1563 list_del_init(&cur_trans
->list
);
1564 spin_unlock(&root
->fs_info
->trans_lock
);
1566 put_transaction(cur_trans
);
1567 put_transaction(cur_trans
);
1569 trace_btrfs_transaction_commit(root
);
1571 btrfs_scrub_continue(root
);
1573 if (current
->journal_info
== trans
)
1574 current
->journal_info
= NULL
;
1576 kmem_cache_free(btrfs_trans_handle_cachep
, trans
);
1578 if (current
!= root
->fs_info
->transaction_kthread
)
1579 btrfs_run_delayed_iputs(root
);
1583 cleanup_transaction
:
1584 btrfs_printk(root
->fs_info
, "Skipping commit of aborted transaction.\n");
1586 if (current
->journal_info
== trans
)
1587 current
->journal_info
= NULL
;
1588 cleanup_transaction(trans
, root
, ret
);
1594 * interface function to delete all the snapshots we have scheduled for deletion
1596 int btrfs_clean_old_snapshots(struct btrfs_root
*root
)
1599 struct btrfs_fs_info
*fs_info
= root
->fs_info
;
1601 spin_lock(&fs_info
->trans_lock
);
1602 list_splice_init(&fs_info
->dead_roots
, &list
);
1603 spin_unlock(&fs_info
->trans_lock
);
1605 while (!list_empty(&list
)) {
1608 root
= list_entry(list
.next
, struct btrfs_root
, root_list
);
1609 list_del(&root
->root_list
);
1611 btrfs_kill_all_delayed_nodes(root
);
1613 if (btrfs_header_backref_rev(root
->node
) <
1614 BTRFS_MIXED_BACKREF_REV
)
1615 ret
= btrfs_drop_snapshot(root
, NULL
, 0, 0);
1617 ret
=btrfs_drop_snapshot(root
, NULL
, 1, 0);