[PATCH 5/7] btrfs: remove unnecessary mutex lock in qgroup_account_snapshot
From: David Sterba <dsterba@suse.com>
Date: 2017-02-13 14:30:58
Subsystem:
btrfs file system, filesystems (vfs and infrastructure), the rest · Maintainers:
Chris Mason, David Sterba, Alexander Viro, Christian Brauner, Linus Torvalds
The quota status used to be tracked as a variable, so the mutex was needed (until "Btrfs: add a flags field to btrfs_fs_info" afcdd129e05a9). Since the status is a bit modified atomically and we don't hold the mutex beyond the check, we can drop it. Signed-off-by: David Sterba <dsterba@suse.com> --- fs/btrfs/transaction.c | 6 +----- 1 file changed, 1 insertion(+), 5 deletions(-)
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 48aabb367f73..5eefd77bafc7 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c@@ -1364,12 +1364,8 @@ static int qgroup_account_snapshot(struct btrfs_trans_handle *trans, * enabled. If this check races with the ioctl, rescan will * kick in anyway. */ - mutex_lock(&fs_info->qgroup_ioctl_lock); - if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags)) { - mutex_unlock(&fs_info->qgroup_ioctl_lock); + if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags)) return 0; - } - mutex_unlock(&fs_info->qgroup_ioctl_lock); /* * We are going to commit transaction, see btrfs_commit_transaction()
--
2.10.1