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

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
...@@ -27,18 +27,15 @@ struct request *blk_queue_find_tag(struct request_queue *q, int tag) ...@@ -27,18 +27,15 @@ struct request *blk_queue_find_tag(struct request_queue *q, int tag)
EXPORT_SYMBOL(blk_queue_find_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 * @bqt: the tag map to free
* *
* Tries to free the specified @bqt. Returns true if it was * Drop the reference count on @bqt and frees it when the last reference
* actually freed and false if there are still references using it * is dropped.
*/ */
static int __blk_free_tags(struct blk_queue_tag *bqt) void blk_free_tags(struct blk_queue_tag *bqt)
{ {
int retval; if (atomic_dec_and_test(&bqt->refcnt)) {
retval = atomic_dec_and_test(&bqt->refcnt);
if (retval) {
BUG_ON(find_first_bit(bqt->tag_map, bqt->max_depth) < BUG_ON(find_first_bit(bqt->tag_map, bqt->max_depth) <
bqt->max_depth); bqt->max_depth);
...@@ -50,9 +47,8 @@ static int __blk_free_tags(struct blk_queue_tag *bqt) ...@@ -50,9 +47,8 @@ static int __blk_free_tags(struct blk_queue_tag *bqt)
kfree(bqt); kfree(bqt);
} }
return retval;
} }
EXPORT_SYMBOL(blk_free_tags);
/** /**
* __blk_queue_free_tags - release tag maintenance info * __blk_queue_free_tags - release tag maintenance info
...@@ -69,27 +65,12 @@ void __blk_queue_free_tags(struct request_queue *q) ...@@ -69,27 +65,12 @@ void __blk_queue_free_tags(struct request_queue *q)
if (!bqt) if (!bqt)
return; return;
__blk_free_tags(bqt); blk_free_tags(bqt);
q->queue_tags = NULL; q->queue_tags = NULL;
queue_flag_clear_unlocked(QUEUE_FLAG_QUEUED, q); 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 * blk_queue_free_tags - release tag maintenance info
* @q: the request queue for the device * @q: the request queue for the device
......
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