Commit 9f985cb6 authored by Jan Kara's avatar Jan Kara Committed by Linus Torvalds
Browse files

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: default avatarJan Kara <jack@suse.cz>
Reviewed-by: default avatarMark Fasheh <mfasheh@suse.de>
Reviewed-by: default avatarSrinivas Eeda <srinivas.eeda@oracle.com>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent bd62ad7a

fs/quota/dquot.c

+2 −2
Original line number Diff line number Diff line
@@ -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);
@@ -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);

include/linux/quotaops.h

+8 −0
Original line number Diff line number Diff line
@@ -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),

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