From 834057bf846691552a8906f7ed3f67546e5f897c Mon Sep 17 00:00:00 2001
From: Jan Kara <jack@suse.cz>
Date: Thu, 3 Aug 2017 11:18:23 +0200
Subject: [PATCH] quota: Allow disabling tracking of dirty dquots in a list
Filesystems that are journalling quotas generally don't need tracking of
dirty dquots in a list since forcing a transaction commit flushes all
quotas anyway. Allow filesystem to say it doesn't want dquots to be
tracked as it reduces contention on the dq_list_lock.
Signed-off-by: Jan Kara <jack@suse.cz>
---
fs/quota/dquot.c | 6 ++++++
include/linux/quota.h | 3 +++
2 files changed, 9 insertions(+)
diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c
index 361a2a6f13e10..b867578e62c08 100644
--- a/fs/quota/dquot.c
+++ b/fs/quota/dquot.c
@@ -344,6 +344,9 @@ int dquot_mark_dquot_dirty(struct dquot *dquot)
if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags))
return 0;
+ if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NOLIST_DIRTY)
+ return test_and_set_bit(DQ_MOD_B, &dquot->dq_flags);
+
/* If quota is dirty already, we don't have to acquire dq_list_lock */
if (test_bit(DQ_MOD_B, &dquot->dq_flags))
return 1;
@@ -385,6 +388,9 @@ static inline void dqput_all(struct dquot **dquot)
static inline int clear_dquot_dirty(struct dquot *dquot)
{
+ if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NOLIST_DIRTY)
+ return test_and_clear_bit(DQ_MOD_B, &dquot->dq_flags);
+
spin_lock(&dq_list_lock);
if (!test_and_clear_bit(DQ_MOD_B, &dquot->dq_flags)) {
spin_unlock(&dq_list_lock);
diff --git a/include/linux/quota.h b/include/linux/quota.h
index ad6809f099ac6..eccc1cb6274e3 100644
--- a/include/linux/quota.h
+++ b/include/linux/quota.h
@@ -490,6 +490,9 @@ enum {
*/
#define DQUOT_NEGATIVE_USAGE (1 << (DQUOT_STATE_LAST + 1))
/* Allow negative quota usage */
+/* Do not track dirty dquots in a list */
+#define DQUOT_NOLIST_DIRTY (1 << (DQUOT_STATE_LAST + 2))
+
static inline unsigned int dquot_state_flag(unsigned int flags, int type)
{
return flags << type;
--
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