From: David Sterba Date: Mon, 13 Feb 2017 13:07:02 +0000 (+0100) Subject: btrfs: remove unnecessary mutex lock in qgroup_account_snapshot X-Git-Tag: v4.11-rc1~69^2~41 X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=9ea6e2b54847a08da87c118e6a197f27eb9b0159;p=linux.git btrfs: remove unnecessary mutex lock in qgroup_account_snapshot 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 --- 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()