[PATCH 2/5] quota: avoid unnecessary dqget()/dqput() calls

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Avoid unnecessary dqget()/dqput() calls in __dquot_initialize(),
that will introduce global lock contention otherwise.

Signed-off-by: Lai Siyao <lai.siyao@xxxxxxxxx>
Signed-off-by: Niu Yawei <yawei.niu@xxxxxxxxx>
---
 fs/quota/dquot.c |   13 ++++++++++++-
 1 files changed, 12 insertions(+), 1 deletions(-)

diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c
index 9cd5f63..a00201d 100644
--- a/fs/quota/dquot.c
+++ b/fs/quota/dquot.c
@@ -1400,7 +1400,7 @@ static int dquot_active(const struct inode *inode)
  */
 static void __dquot_initialize(struct inode *inode, int type)
 {
-	int cnt;
+	int cnt, init_needed = 0;
 	struct dquot *got[MAXQUOTAS];
 	struct super_block *sb = inode->i_sb;
 	qsize_t rsv;
@@ -1416,6 +1416,13 @@ static void __dquot_initialize(struct inode *inode, int type)
 		got[cnt] = NULL;
 		if (type != -1 && cnt != type)
 			continue;
+		/* The i_dquot should have been initialized in most cases,
+		 * we check it without locking here to avoid unnecessary
+		 * dqget()/dqput() calls. */
+		if (inode->i_dquot[cnt])
+			continue;
+		init_needed = 1;
+
 		switch (cnt) {
 		case USRQUOTA:
 			qid = make_kqid_uid(inode->i_uid);
@@ -1427,6 +1434,10 @@ static void __dquot_initialize(struct inode *inode, int type)
 		got[cnt] = dqget(sb, qid);
 	}
 
+	/* All required i_dquot has been initialized */
+	if (!init_needed)
+		return;
+
 	down_write(&sb_dqopt(sb)->dqptr_sem);
 	if (IS_NOQUOTA(inode))
 		goto out_err;
-- 
1.7.1


--
To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html




[Index of Archives]     [Linux Ext4 Filesystem]     [Union Filesystem]     [Filesystem Testing]     [Ceph Users]     [Ecryptfs]     [AutoFS]     [Kernel Newbies]     [Share Photos]     [Security]     [Netfilter]     [Bugtraq]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux Cachefs]     [Reiser Filesystem]     [Linux RAID]     [Samba]     [Device Mapper]     [CEPH Development]
  Powered by Linux