From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jan Kara Date: Wed, 26 Feb 2014 12:05:55 +0100 Subject: [Ocfs2-devel] [PATCH 3/6] quota: Provide function to grab quota structure reference In-Reply-To: <1393412758-9764-1-git-send-email-jack@suse.cz> References: <1393412758-9764-1-git-send-email-jack@suse.cz> Message-ID: <1393412758-9764-4-git-send-email-jack@suse.cz> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: ocfs2-devel@oss.oracle.com Provide dqgrab() function to get quota structure reference when we are sure it already has at least one active reference. Make use of this function inside quota code. Reviewed-by: Mark Fasheh Reviewed-by: Srinivas Eeda Signed-off-by: Jan Kara --- fs/quota/dquot.c | 4 ++-- include/linux/quotaops.h | 8 ++++++++ 2 files changed, 10 insertions(+), 2 deletions(-) diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c index 831d49a4111f..e3f09e34d0b2 100644 --- a/fs/quota/dquot.c +++ b/fs/quota/dquot.c @@ -528,7 +528,7 @@ restart: if (atomic_read(&dquot->dq_count)) { DEFINE_WAIT(wait); - atomic_inc(&dquot->dq_count); + dqgrab(dquot); prepare_to_wait(&dquot->dq_wait_unused, &wait, TASK_UNINTERRUPTIBLE); spin_unlock(&dq_list_lock); @@ -624,7 +624,7 @@ int dquot_writeback_dquots(struct super_block *sb, int type) /* Now we have active dquot from which someone is * holding reference so we can safely just increase * use count */ - atomic_inc(&dquot->dq_count); + dqgrab(dquot); spin_unlock(&dq_list_lock); dqstats_inc(DQST_LOOKUPS); err = sb->dq_op->write_dquot(dquot); diff --git a/include/linux/quotaops.h b/include/linux/quotaops.h index 6965fe394c3b..1d3eee594cd6 100644 --- a/include/linux/quotaops.h +++ b/include/linux/quotaops.h @@ -46,6 +46,14 @@ void inode_reclaim_rsv_space(struct inode *inode, qsize_t number); void dquot_initialize(struct inode *inode); void dquot_drop(struct inode *inode); struct dquot *dqget(struct super_block *sb, struct kqid qid); +static inline struct dquot *dqgrab(struct dquot *dquot) +{ + /* Make sure someone else has active reference to dquot */ + WARN_ON_ONCE(!atomic_read(&dquot->dq_count)); + WARN_ON_ONCE(!test_bit(DQ_ACTIVE_B, &dquot->dq_flags)); + atomic_inc(&dquot->dq_count); + return dquot; +} void dqput(struct dquot *dquot); int dquot_scan_active(struct super_block *sb, int (*fn)(struct dquot *dquot, unsigned long priv), -- 1.8.1.4