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authorChristoph Hellwig <hch@lst.de>2014-07-08 12:25:28 +0200
committerJens Axboe <axboe@fb.com>2014-07-08 12:25:28 +0200
commitd45b3279a5a2252cafcd665bbf2db8c9b31ef783 (patch)
tree45aa82b20beba9c325ca64f31ab798d27cfdc702 /block/blk-tag.c
parent448bfad8a185876ce8de484a921d49769972cad7 (diff)
downloadlinux-0-day-d45b3279a5a2252cafcd665bbf2db8c9b31ef783.tar.gz
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: Christoph Hellwig <hch@lst.de> Cc: stable@kernel.org Signed-off-by: Jens Axboe <axboe@fb.com>
Diffstat (limited to 'block/blk-tag.c')
-rw-r--r--block/blk-tag.c33
1 files changed, 7 insertions, 26 deletions
diff --git a/block/blk-tag.c b/block/blk-tag.c
index 3f33d86..a185b86 100644
--- a/block/blk-tag.c
+++ b/block/blk-tag.c
@@ -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
@@ -69,28 +65,13 @@ 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
*