quota: provide function to grab quota structure reference

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.

Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Mark Fasheh <mfasheh@suse.de>
Reviewed-by: Srinivas Eeda <srinivas.eeda@oracle.com>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Jan Kara 2014-04-03 14:46:55 -07:00 committed by Linus Torvalds
parent bd62ad7aeb
commit 9f985cb6c4
2 changed files with 10 additions and 2 deletions

View File

@ -528,7 +528,7 @@ static void invalidate_dquots(struct super_block *sb, int type)
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);
@ -632,7 +632,7 @@ 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);

View File

@ -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),