Re: [PATCH 13/17] xfs: move q_qlock locking into xchk_quota_item

["Darrick J. Wong" <djwong@kernel.org>]

On Mon, Oct 13, 2025 at 11:48:14AM +0900, Christoph Hellwig wrote:
> This avoids a pointless roundtrip because ilock needs to be taken first.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>

Yep!
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>

--D

> ---
>  fs/xfs/scrub/quota.c | 6 +-----
>  1 file changed, 1 insertion(+), 5 deletions(-)
> 
> diff --git a/fs/xfs/scrub/quota.c b/fs/xfs/scrub/quota.c
> index b711d36c5ec9..5c5374c44c5a 100644
> --- a/fs/xfs/scrub/quota.c
> +++ b/fs/xfs/scrub/quota.c
> @@ -155,10 +155,7 @@ xchk_quota_item(
>  	 * We want to validate the bmap record for the storage backing this
>  	 * dquot, so we need to lock the dquot and the quota file.  For quota
>  	 * operations, the locking order is first the ILOCK and then the dquot.
> -	 * However, dqiterate gave us a locked dquot, so drop the dquot lock to
> -	 * get the ILOCK.
>  	 */
> -	mutex_unlock(&dq->q_qlock);
>  	xchk_ilock(sc, XFS_ILOCK_SHARED);
>  	mutex_lock(&dq->q_qlock);
>  
> @@ -251,6 +248,7 @@ xchk_quota_item(
>  	xchk_quota_item_timer(sc, offset, &dq->q_rtb);
>  
>  out:
> +	mutex_unlock(&dq->q_qlock);
>  	if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
>  		return -ECANCELED;
>  
> @@ -329,9 +327,7 @@ xchk_quota(
>  	/* Now look for things that the quota verifiers won't complain about. */
>  	xchk_dqiter_init(&cursor, sc, dqtype);
>  	while ((error = xchk_dquot_iter(&cursor, &dq)) == 1) {
> -		mutex_lock(&dq->q_qlock);
>  		error = xchk_quota_item(&sqi, dq);
> -		mutex_unlock(&dq->q_qlock);
>  		xfs_qm_dqrele(dq);
>  		if (error)
>  			break;
> -- 
> 2.47.3
> 
>