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Diffstat (limited to 'block/blk-tag.c')
-rw-r--r--block/blk-tag.c50
1 files changed, 18 insertions, 32 deletions
diff --git a/block/blk-tag.c b/block/blk-tag.c
index 4af6f5cc116..a185b86741e 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
*
@@ -186,7 +167,8 @@ int blk_queue_init_tags(struct request_queue *q, int depth,
tags = __blk_queue_init_tags(q, depth);
if (!tags)
- goto fail;
+ return -ENOMEM;
+
} else if (q->queue_tags) {
rc = blk_queue_resize_tags(q, depth);
if (rc)
@@ -203,9 +185,6 @@ int blk_queue_init_tags(struct request_queue *q, int depth,
queue_flag_set_unlocked(QUEUE_FLAG_QUEUED, q);
INIT_LIST_HEAD(&q->tag_busy_list);
return 0;
-fail:
- kfree(tags);
- return -ENOMEM;
}
EXPORT_SYMBOL(blk_queue_init_tags);
@@ -350,9 +329,16 @@ int blk_queue_start_tag(struct request_queue *q, struct request *rq)
*/
max_depth = bqt->max_depth;
if (!rq_is_sync(rq) && max_depth > 1) {
- max_depth -= 2;
- if (!max_depth)
+ switch (max_depth) {
+ case 2:
max_depth = 1;
+ break;
+ case 3:
+ max_depth = 2;
+ break;
+ default:
+ max_depth -= 2;
+ }
if (q->in_flight[BLK_RW_ASYNC] > max_depth)
return 1;
}