xfs: move quota locking into xrep_quota_item

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>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Carlos Maiolino <cem@kernel.org>

Author: Christoph Hellwig

fs/xfs/scrub/quota_repair.c

@@ -184,17 +184,13 @@ xrep_quota_item(
 	/*
 	 * We might need to fix holes in the bmap record for the storage
 	 * backing this dquot, so we need to lock the dquot and the quota file.
-	 * dqiterate gave us a locked dquot, so drop the dquot lock to get the
-	 * ILOCK_EXCL.
 	 */
-	mutex_unlock(&dq->q_qlock);
 	xchk_ilock(sc, XFS_ILOCK_EXCL);
 	mutex_lock(&dq->q_qlock);
-
 	error = xrep_quota_item_bmap(sc, dq, &dirty);
 	xchk_iunlock(sc, XFS_ILOCK_EXCL);
 	if (error)
-		return error;
+		goto out_unlock_dquot;
 
 	/* Check the limits. */
 	if (dq->q_blk.softlimit > dq->q_blk.hardlimit) {
@@ -246,7 +242,7 @@ xrep_quota_item(
 	xrep_quota_item_timer(sc, &dq->q_rtb, &dirty);
 
 	if (!dirty)
-		return 0;
+		goto out_unlock_dquot;
 
 	trace_xrep_dquot_item(sc->mp, dq->q_type, dq->q_id);
 
@@ -257,8 +253,10 @@ xrep_quota_item(
 		xfs_qm_adjust_dqtimers(dq);
 	}
 	xfs_trans_log_dquot(sc->tp, dq);
-	error = xfs_trans_roll(&sc->tp);
-	mutex_lock(&dq->q_qlock);
+	return xfs_trans_roll(&sc->tp);
+
+out_unlock_dquot:
+	mutex_unlock(&dq->q_qlock);
 	return error;
 }
 
@@ -512,9 +510,7 @@ xrep_quota_problems(
 
 	xchk_dqiter_init(&cursor, sc, dqtype);
 	while ((error = xchk_dquot_iter(&cursor, &dq)) == 1) {
-		mutex_lock(&dq->q_qlock);
 		error = xrep_quota_item(&rqi, dq);
-		mutex_unlock(&dq->q_qlock);
 		xfs_qm_dqrele(dq);
 		if (error)
 			break;