quota: optimize mark_dirty logic
- Skip locking if quota is dirty already.
- Return old quota state to help fs-specciffic implementation to optimize
case where quota was dirty already.
Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: Jan Kara <jack@suse.cz>
diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c
index 788b580..05c590e 100644
--- a/fs/quota/dquot.c
+++ b/fs/quota/dquot.c
@@ -317,14 +317,23 @@
return dquot->dq_sb->dq_op->mark_dirty(dquot);
}
+/* Mark dquot dirty in atomic manner, and return it's old dirty flag state */
int dquot_mark_dquot_dirty(struct dquot *dquot)
{
+ int ret = 1;
+
+ /* 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;
+
spin_lock(&dq_list_lock);
- if (!test_and_set_bit(DQ_MOD_B, &dquot->dq_flags))
+ if (!test_and_set_bit(DQ_MOD_B, &dquot->dq_flags)) {
list_add(&dquot->dq_dirty, &sb_dqopt(dquot->dq_sb)->
info[dquot->dq_type].dqi_dirty_list);
+ ret = 0;
+ }
spin_unlock(&dq_list_lock);
- return 0;
+ return ret;
}
EXPORT_SYMBOL(dquot_mark_dquot_dirty);