Commit d45b3279 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Jens Axboe
Browse files

block: don't assume last put of shared tags is for the host 



There is no inherent reason why the last put of a tag structure must be
the one for the Scsi_Host, as device model objects can be held for
arbitrary periods.  Merge blk_free_tags and __blk_free_tags into a single
funtion that just release a references and get rid of the BUG() when the
host reference wasn't the last.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Cc: stable@kernel.org
Signed-off-by: default avatarJens Axboe <axboe@fb.com>
parent 448bfad8

block/blk-tag.c

+7 −26
Original line number Diff line number Diff line
@@ -27,18 +27,15 @@ struct request *blk_queue_find_tag(struct request_queue *q, int tag) 
EXPORT_SYMBOL(blk_queue_find_tag);



/**

 * __blk_free_tags - release a given set of tag maintenance info

 * blk_free_tags - release a given set of tag maintenance info

 * @bqt:	the tag map to free

 *

 * Tries to free the specified @bqt.  Returns true if it was

 * actually freed and false if there are still references using it

 * Drop the reference count on @bqt and frees it when the last reference

 * is dropped.

 */

static int __blk_free_tags(struct blk_queue_tag *bqt)

void blk_free_tags(struct blk_queue_tag *bqt)

{

	int retval;



	retval = atomic_dec_and_test(&bqt->refcnt);

	if (retval) {

	if (atomic_dec_and_test(&bqt->refcnt)) {

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

							bqt->max_depth);
@@ -50,9 +47,8 @@ static int __blk_free_tags(struct blk_queue_tag *bqt) 


		kfree(bqt);

	}



	return retval;

}

EXPORT_SYMBOL(blk_free_tags);



/**

 * __blk_queue_free_tags - release tag maintenance info
@@ -69,27 +65,12 @@ void __blk_queue_free_tags(struct request_queue *q) 
	if (!bqt)

		return;



	__blk_free_tags(bqt);

	blk_free_tags(bqt);



	q->queue_tags = NULL;

	queue_flag_clear_unlocked(QUEUE_FLAG_QUEUED, q);

}



/**

 * blk_free_tags - release a given set of tag maintenance info

 * @bqt:	the tag map to free

 *

 * For externally managed @bqt frees the map.  Callers of this

 * function must guarantee to have released all the queues that

 * might have been using this tag map.

 */

void blk_free_tags(struct blk_queue_tag *bqt)

{

	if (unlikely(!__blk_free_tags(bqt)))

		BUG();

}

EXPORT_SYMBOL(blk_free_tags);



/**

 * blk_queue_free_tags - release tag maintenance info

 * @q:  the request queue for the device

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