Re: [PATCH 15/18] xfs: move quota locking into xqcheck_commit_dquot

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

On Mon, Nov 10, 2025 at 02:23:07PM +0100, Christoph Hellwig wrote:
> Drop two redundant lock roundtrips by not requiring q_lock to be held on
> entry and return.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>

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

--D

> ---
>  fs/xfs/scrub/quotacheck_repair.c | 21 ++-------------------
>  1 file changed, 2 insertions(+), 19 deletions(-)
> 
> diff --git a/fs/xfs/scrub/quotacheck_repair.c b/fs/xfs/scrub/quotacheck_repair.c
> index 3013211fa6c1..51be8d8d261b 100644
> --- a/fs/xfs/scrub/quotacheck_repair.c
> +++ b/fs/xfs/scrub/quotacheck_repair.c
> @@ -52,13 +52,11 @@ xqcheck_commit_dquot(
>  	bool			dirty = false;
>  	int			error = 0;
>  
> -	/* Unlock the dquot just long enough to allocate a transaction. */
> -	mutex_unlock(&dq->q_qlock);
>  	error = xchk_trans_alloc(xqc->sc, 0);
> -	mutex_lock(&dq->q_qlock);
>  	if (error)
>  		return error;
>  
> +	mutex_lock(&dq->q_qlock);
>  	xfs_trans_dqjoin(xqc->sc->tp, dq);
>  
>  	if (xchk_iscan_aborted(&xqc->iscan)) {
> @@ -115,23 +113,12 @@ xqcheck_commit_dquot(
>  	if (dq->q_id)
>  		xfs_qm_adjust_dqtimers(dq);
>  	xfs_trans_log_dquot(xqc->sc->tp, dq);
> -
> -	/*
> -	 * Transaction commit unlocks the dquot, so we must re-lock it so that
> -	 * the caller can put the reference (which apparently requires a locked
> -	 * dquot).
> -	 */
> -	error = xrep_trans_commit(xqc->sc);
> -	mutex_lock(&dq->q_qlock);
> -	return error;
> +	return xrep_trans_commit(xqc->sc);
>  
>  out_unlock:
>  	mutex_unlock(&xqc->lock);
>  out_cancel:
>  	xchk_trans_cancel(xqc->sc);
> -
> -	/* Re-lock the dquot so the caller can put the reference. */
> -	mutex_lock(&dq->q_qlock);
>  	return error;
>  }
>  
> @@ -155,9 +142,7 @@ xqcheck_commit_dqtype(
>  	 */
>  	xchk_dqiter_init(&cursor, sc, dqtype);
>  	while ((error = xchk_dquot_iter(&cursor, &dq)) == 1) {
> -		mutex_lock(&dq->q_qlock);
>  		error = xqcheck_commit_dquot(xqc, dqtype, dq);
> -		mutex_unlock(&dq->q_qlock);
>  		xfs_qm_dqrele(dq);
>  		if (error)
>  			break;
> @@ -188,9 +173,7 @@ xqcheck_commit_dqtype(
>  		if (error)
>  			return error;
>  
> -		mutex_lock(&dq->q_qlock);
>  		error = xqcheck_commit_dquot(xqc, dqtype, dq);
> -		mutex_unlock(&dq->q_qlock);
>  		xfs_qm_dqrele(dq);
>  		if (error)
>  			return error;
> -- 
> 2.47.3
> 
>