[PATCH v5 3/3] xfs: directly return if the delta equal to zero

[xiakaixu1987@gmail.com]

From: Kaixu Xia <kaixuxia@tencent.com>

The xfs_trans_mod_dquot() function will allocate new tp->t_dqinfo if it is
NULL and make the changes in the tp->t_dqinfo->dqs[XFS_QM_TRANS_{USR,GRP,PRJ}].
Nowadays seems none of the callers want to join the dquots to the
transaction and push them to device when the delta is zero. Actually,
most of time the caller would check the delta and go on only when the
delta value is not zero, so we should bail out when it is zero.

Signed-off-by: Kaixu Xia <kaixuxia@tencent.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
---
 fs/xfs/xfs_trans_dquot.c | 26 ++++++++++++--------------
 1 file changed, 12 insertions(+), 14 deletions(-)

diff --git a/fs/xfs/xfs_trans_dquot.c b/fs/xfs/xfs_trans_dquot.c
index 0ebfd7930382..6e243e8b30ec 100644
--- a/fs/xfs/xfs_trans_dquot.c
+++ b/fs/xfs/xfs_trans_dquot.c
@@ -194,6 +194,9 @@ xfs_trans_mod_dquot(
 	ASSERT(XFS_IS_QUOTA_RUNNING(tp->t_mountp));
 	qtrx = NULL;
 
+	if (!delta)
+		return;
+
 	if (tp->t_dqinfo == NULL)
 		xfs_trans_alloc_dqinfo(tp);
 	/*
@@ -205,10 +208,8 @@ xfs_trans_mod_dquot(
 	if (qtrx->qt_dquot == NULL)
 		qtrx->qt_dquot = dqp;
 
-	if (delta) {
-		trace_xfs_trans_mod_dquot_before(qtrx);
-		trace_xfs_trans_mod_dquot(tp, dqp, field, delta);
-	}
+	trace_xfs_trans_mod_dquot_before(qtrx);
+	trace_xfs_trans_mod_dquot(tp, dqp, field, delta);
 
 	switch (field) {
 	/* regular disk blk reservation */
@@ -261,8 +262,7 @@ xfs_trans_mod_dquot(
 		ASSERT(0);
 	}
 
-	if (delta)
-		trace_xfs_trans_mod_dquot_after(qtrx);
+	trace_xfs_trans_mod_dquot_after(qtrx);
 }
 
 
@@ -687,14 +687,12 @@ xfs_trans_dqresv(
 	 */
 	if (tp) {
 		ASSERT(flags & XFS_QMOPT_RESBLK_MASK);
-		if (nblks != 0)
-			xfs_trans_mod_dquot(tp, dqp,
-					    flags & XFS_QMOPT_RESBLK_MASK,
-					    nblks);
-		if (ninos != 0)
-			xfs_trans_mod_dquot(tp, dqp,
-					    XFS_TRANS_DQ_RES_INOS,
-					    ninos);
+		xfs_trans_mod_dquot(tp, dqp,
+				    flags & XFS_QMOPT_RESBLK_MASK,
+				    nblks);
+		xfs_trans_mod_dquot(tp, dqp,
+				    XFS_TRANS_DQ_RES_INOS,
+				    ninos);
 	}
 	ASSERT(dqp->q_blk.reserved >= dqp->q_blk.count);
 	ASSERT(dqp->q_rtb.reserved >= dqp->q_rtb.count);
-- 
2.20.0