blk-mq-tag: document tag iteration helper return value

Document the fact that the strategy function passed in can
control whether to continue iterating or not.

Suggested-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c
index 097e9a67d5f543dbfe1ce6a4dd66baddfccf2b56..87bc5df72d48a3a66ed2141f5240c3083c336037 100644 (file)
--- a/block/blk-mq-tag.c
+++ b/block/blk-mq-tag.c
@@ -248,7 +248,8 @@ static bool bt_iter(struct sbitmap *bitmap, unsigned int bitnr, void *data)
  * @fn:                Pointer to the function that will be called for each request
  *             associated with @hctx that has been assigned a driver tag.
  *             @fn will be called as follows: @fn(@hctx, rq, @data, @reserved)
- *             where rq is a pointer to a request.
+ *             where rq is a pointer to a request. Return true to continue
+ *             iterating tags, false to stop.
  * @data:      Will be passed as third argument to @fn.
  * @reserved:  Indicates whether @bt is the breserved_tags member or the
  *             bitmap_tags member of struct blk_mq_tags.
@@ -301,7 +302,8 @@ static bool bt_tags_iter(struct sbitmap *bitmap, unsigned int bitnr, void *data)
  *             or the bitmap_tags member of struct blk_mq_tags.
  * @fn:                Pointer to the function that will be called for each started
  *             request. @fn will be called as follows: @fn(rq, @data,
- *             @reserved) where rq is a pointer to a request.
+ *             @reserved) where rq is a pointer to a request. Return true
+ *             to continue iterating tags, false to stop.
  * @data:      Will be passed as second argument to @fn.
  * @reserved:  Indicates whether @bt is the breserved_tags member or the
  *             bitmap_tags member of struct blk_mq_tags.
@@ -326,7 +328,8 @@ static void bt_tags_for_each(struct blk_mq_tags *tags, struct sbitmap_queue *bt,
  * @fn:                Pointer to the function that will be called for each started
  *             request. @fn will be called as follows: @fn(rq, @priv,
  *             reserved) where rq is a pointer to a request. 'reserved'
- *             indicates whether or not @rq is a reserved request.
+ *             indicates whether or not @rq is a reserved request. Return
+ *             true to continue iterating tags, false to stop.
  * @priv:      Will be passed as second argument to @fn.
  */
 static void blk_mq_all_tag_busy_iter(struct blk_mq_tags *tags,
@@ -343,7 +346,8 @@ static void blk_mq_all_tag_busy_iter(struct blk_mq_tags *tags,
  * @fn:                Pointer to the function that will be called for each started
  *             request. @fn will be called as follows: @fn(rq, @priv,
  *             reserved) where rq is a pointer to a request. 'reserved'
- *             indicates whether or not @rq is a reserved request.
+ *             indicates whether or not @rq is a reserved request. Return
+ *             true to continue iterating tags, false to stop.
  * @priv:      Will be passed as second argument to @fn.
  */
 void blk_mq_tagset_busy_iter(struct blk_mq_tag_set *tagset,