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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" afcdd129e0).
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>
This commit is contained in:
David Sterba 2017-02-13 14:07:02 +01:00
parent 81353d50f5
commit 9ea6e2b548
1 changed files with 1 additions and 5 deletions
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6
fs/btrfs/transaction.c
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@ -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()