diff options
Diffstat (limited to 'fs/btrfs/extent-tree.c')
-rw-r--r-- | fs/btrfs/extent-tree.c | 44 |
1 files changed, 0 insertions, 44 deletions
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index 7eef91d6c2b6..9dcd70cc3ca3 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -5740,47 +5740,3 @@ int btrfs_trim_fs(struct btrfs_fs_info *fs_info, struct fstrim_range *range) return bg_ret; return dev_ret; } - -/* - * btrfs_{start,end}_write_no_snapshotting() are similar to - * mnt_{want,drop}_write(), they are used to prevent some tasks from writing - * data into the page cache through nocow before the subvolume is snapshoted, - * but flush the data into disk after the snapshot creation, or to prevent - * operations while snapshotting is ongoing and that cause the snapshot to be - * inconsistent (writes followed by expanding truncates for example). - */ -void btrfs_end_write_no_snapshotting(struct btrfs_root *root) -{ - percpu_counter_dec(&root->subv_writers->counter); - cond_wake_up(&root->subv_writers->wait); -} - -int btrfs_start_write_no_snapshotting(struct btrfs_root *root) -{ - if (atomic_read(&root->will_be_snapshotted)) - return 0; - - percpu_counter_inc(&root->subv_writers->counter); - /* - * Make sure counter is updated before we check for snapshot creation. - */ - smp_mb(); - if (atomic_read(&root->will_be_snapshotted)) { - btrfs_end_write_no_snapshotting(root); - return 0; - } - return 1; -} - -void btrfs_wait_for_snapshot_creation(struct btrfs_root *root) -{ - while (true) { - int ret; - - ret = btrfs_start_write_no_snapshotting(root); - if (ret) - break; - wait_var_event(&root->will_be_snapshotted, - !atomic_read(&root->will_be_snapshotted)); - } -} |