[BLOCK] Get rid of request_queue_t typedef

[deliverable/linux.git] / Documentation / block / biodoc.txt

diff --git a/Documentation/block/biodoc.txt b/Documentation/block/biodoc.txt
index c6c9a9c10d7f88b5f894990e45878acadbb2ea64..8af392fc6ef0e74b115257b5d31bb4345cd09f9f 100644 (file)
--- a/Documentation/block/biodoc.txt
+++ b/Documentation/block/biodoc.txt
@@ -740,12 +740,12 @@ Block now offers some simple generic functionality to help support command
 queueing (typically known as tagged command queueing), ie manage more than
 one outstanding command on a queue at any given time.
 
-       blk_queue_init_tags(request_queue_t *q, int depth)
+       blk_queue_init_tags(struct request_queue *q, int depth)
 
        Initialize internal command tagging structures for a maximum
        depth of 'depth'.
 
-       blk_queue_free_tags((request_queue_t *q)
+       blk_queue_free_tags((struct request_queue *q)
 
        Teardown tag info associated with the queue. This will be done
        automatically by block if blk_queue_cleanup() is called on a queue
@@ -754,7 +754,7 @@ one outstanding command on a queue at any given time.
 The above are initialization and exit management, the main helpers during
 normal operations are:
 
-       blk_queue_start_tag(request_queue_t *q, struct request *rq)
+       blk_queue_start_tag(struct request_queue *q, struct request *rq)
 
        Start tagged operation for this request. A free tag number between
        0 and 'depth' is assigned to the request (rq->tag holds this number),
@@ -762,7 +762,7 @@ normal operations are:
        for this queue is already achieved (or if the tag wasn't started for
        some other reason), 1 is returned. Otherwise 0 is returned.
 
-       blk_queue_end_tag(request_queue_t *q, struct request *rq)
+       blk_queue_end_tag(struct request_queue *q, struct request *rq)
 
        End tagged operation on this request. 'rq' is removed from the internal
        book keeping structures.
@@ -781,7 +781,7 @@ queue. For instance, on IDE any tagged request error needs to clear both
 the hardware and software block queue and enable the driver to sanely restart
 all the outstanding requests. There's a third helper to do that:
 
-       blk_queue_invalidate_tags(request_queue_t *q)
+       blk_queue_invalidate_tags(struct request_queue *q)
 
        Clear the internal block tag queue and re-add all the pending requests
        to the request queue. The driver will receive them again on the
@@ -946,6 +946,13 @@ elevator_merged_fn         called when a request in the scheduler has been
                                scheduler for example, to reposition the request
                                if its sorting order has changed.
 
+elevator_allow_merge_fn                called whenever the block layer determines
+                               that a bio can be merged into an existing
+                               request safely. The io scheduler may still
+                               want to stop a merge at this point if it
+                               results in some sort of conflict internally,
+                               this hook allows it to do that.
+
 elevator_dispatch_fn           fills the dispatch queue with ready requests.
                                I/O schedulers are free to postpone requests by
                                not filling the dispatch queue unless @force