Commit 0e3eb45e authored by Matthew Wilcox's avatar Matthew Wilcox Committed by Jens Axboe
Browse files

block: remove unused ->busy part of the block queue tag map 



It's not used for anything. On top of that, it's racy and can thus
trigger a faulty BUG_ON() in __blk_free_tags() on queue exit.

Signed-off-by: default avatarJens Axboe <jens.axboe@oracle.com>
parent aefcc28a

block/blk-tag.c

+2 −4
Original line number Diff line number Diff line
@@ -38,7 +38,8 @@ static int __blk_free_tags(struct blk_queue_tag *bqt) 


	retval = atomic_dec_and_test(&bqt->refcnt);

	if (retval) {

		BUG_ON(bqt->busy);

		BUG_ON(find_first_bit(bqt->tag_map, bqt->max_depth) <

							bqt->max_depth);



		kfree(bqt->tag_index);

		bqt->tag_index = NULL;
@@ -147,7 +148,6 @@ static struct blk_queue_tag *__blk_queue_init_tags(struct request_queue *q, 
	if (init_tag_map(q, tags, depth))

		goto fail;



	tags->busy = 0;

	atomic_set(&tags->refcnt, 1);

	return tags;

fail:
@@ -313,7 +313,6 @@ void blk_queue_end_tag(struct request_queue *q, struct request *rq) 
	 * unlock memory barrier semantics.

	 */

	clear_bit_unlock(tag, bqt->tag_map);

	bqt->busy--;

}

EXPORT_SYMBOL(blk_queue_end_tag);
@@ -368,7 +367,6 @@ int blk_queue_start_tag(struct request_queue *q, struct request *rq) 
	bqt->tag_index[tag] = rq;

	blkdev_dequeue_request(rq);

	list_add(&rq->queuelist, &q->tag_busy_list);

	bqt->busy++;

	return 0;

}

EXPORT_SYMBOL(blk_queue_start_tag);