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authorDmitry Monakhov <dmonakhov@openvz.org>2010-03-27 15:15:38 +0300
committerJan Kara <jack@suse.cz>2010-05-21 19:30:37 +0200
commiteabf290d1470921f0ce5a9b22464ae30646a0677 (patch)
treeba3a4ae74101a2ca31fabdbfa3576776cbddf2ed
parent46891532370e862d6bddedef9e6ca22a59a51fa4 (diff)
downloadlinux-eabf290d1470921f0ce5a9b22464ae30646a0677.tar.bz2
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>
-rw-r--r--fs/quota/dquot.c13
1 files changed, 11 insertions, 2 deletions
diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c
index 788b5802a7ce..05c590e10ac2 100644
--- a/fs/quota/dquot.c
+++ b/fs/quota/dquot.c
@@ -317,14 +317,23 @@ static inline int mark_dquot_dirty(struct dquot *dquot)
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);