diff options
| author |   Niu Yawei <yawei.niu@gmail.com> | 2014-06-04 12:20:30 +0800 |
|---|---|---|
| committer |   Jan Kara <jack@suse.cz> | 2014-07-15 22:40:21 +0200 |
| commit | 1ea06bec78a128adc995ca32bd906a6c9bb9cf91 (patch) | |
| tree | e306601eeb564fcc425841f8591df5069e3a9d15 /fs/quota | |
| parent | quota: protect Q_GETFMT by dqonoff_mutex (diff) | |
| download | linux-dev-1ea06bec78a128adc995ca32bd906a6c9bb9cf91.tar.xz linux-dev-1ea06bec78a128adc995ca32bd906a6c9bb9cf91.zip | |
quota: avoid unnecessary dqget()/dqput() calls
Avoid unnecessary dqget()/dqput() calls in __dquot_initialize(),
that will introduce global lock contention otherwise.
Signed-off-by: Lai Siyao <lai.siyao@intel.com>
Signed-off-by: Niu Yawei <yawei.niu@intel.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Diffstat (limited to 'fs/quota')
| -rw-r--r-- | fs/quota/dquot.c | 15 |
1 files changed, 14 insertions, 1 deletions
diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c index 7f30bdc57d13..251771916069 100644 --- a/fs/quota/dquot.c +++ b/fs/quota/dquot.c @@ -1402,7 +1402,7 @@ 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; @@ -1418,6 +1418,15 @@ 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); @@ -1429,6 +1438,10 @@ 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; |