[PATCH -mm] [1/3] add elv_extended_request call to iosched API

[Nate Diller]

the Elevator iosched would prefer to be unconditionally notified of a
merge, but the current API calls only one 'merge' notifier
(elv_merge_requests or elv_merged_requests), even if both front and
back merges happened.

elv_extended_request satisfies this requirement in conjunction with
elv_merge_requests.

Signed-off-by: Nate Diller <nate.diller@xxxxxxxxx>

---
block/elevator.c         |    9 +++++++++
block/ll_rw_blk.c        |    2 ++
include/linux/elevator.h |    4 ++++
3 files changed, 15 insertions(+)
---

diff -urpN -X dontdiff linux-2.6.18-rc1-mm2/block/elevator.c
linux-dput/block/elevator.c
--- linux-2.6.18-rc1-mm2/block/elevator.c	2006-07-18 14:52:29.000000000 -0700
+++ linux-dput/block/elevator.c	2006-08-03 18:42:00.000000000 -0700
@@ -287,6 +287,15 @@ void elv_merged_request(request_queue_t
	q->last_merge = rq;
}

+void elv_extended_request(request_queue_t *q, struct request *rq,
+			int direction, int nr_sectors)
+{
+	elevator_t *e = q->elevator;
+
+	if (e->ops->elevator_extended_req_fn)
+		e->ops->elevator_extended_req_fn(q, rq, direction, nr_sectors);
+}
+
void elv_merge_requests(request_queue_t *q, struct request *rq,
			     struct request *next)
{
diff -urpN -X dontdiff linux-2.6.18-rc1-mm2/block/ll_rw_blk.c
linux-dput/block/ll_rw_blk.c
--- linux-2.6.18-rc1-mm2/block/ll_rw_blk.c	2006-07-18 15:00:44.000000000 -0700
+++ linux-dput/block/ll_rw_blk.c	2006-08-03 18:42:00.000000000 -0700
@@ -2895,6 +2895,7 @@ static int __make_request(request_queue_
			req->nr_sectors = req->hard_nr_sectors += nr_sectors;
			req->ioprio = ioprio_best(req->ioprio, prio);
			drive_stat_acct(req, nr_sectors, 0);
+			elv_extended_request(q, req, el_ret, nr_sectors);
			if (!attempt_back_merge(q, req))
				elv_merged_request(q, req);
			goto out;
@@ -2922,6 +2923,7 @@ static int __make_request(request_queue_
			req->nr_sectors = req->hard_nr_sectors += nr_sectors;
			req->ioprio = ioprio_best(req->ioprio, prio);
			drive_stat_acct(req, nr_sectors, 0);
+			elv_extended_request(q, req, el_ret, nr_sectors);
			if (!attempt_front_merge(q, req))
				elv_merged_request(q, req);
			goto out;
diff -urpN -X dontdiff linux-2.6.18-rc1-mm2/include/linux/elevator.h
linux-dput/include/linux/elevator.h
--- linux-2.6.18-rc1-mm2/include/linux/elevator.h	2006-06-17
18:49:35.000000000 -0700
+++ linux-dput/include/linux/elevator.h	2006-08-03 18:42:00.000000000 -0700
@@ -6,6 +6,8 @@ typedef int (elevator_merge_fn) (request

typedef void (elevator_merge_req_fn) (request_queue_t *, struct
request *, struct request *);

+typedef void (elevator_extended_req_fn) (request_queue_t *, struct
request *, int, int);
+
typedef void (elevator_merged_fn) (request_queue_t *, struct request *);

typedef int (elevator_dispatch_fn) (request_queue_t *, int);
@@ -28,6 +30,7 @@ struct elevator_ops
{
	elevator_merge_fn *elevator_merge_fn;
	elevator_merged_fn *elevator_merged_fn;
+	elevator_extended_req_fn *elevator_extended_req_fn;
	elevator_merge_req_fn *elevator_merge_req_fn;

	elevator_dispatch_fn *elevator_dispatch_fn;
@@ -94,6 +97,7 @@ extern void elv_insert(request_queue_t *
extern int elv_merge(request_queue_t *, struct request **, struct bio *);
extern void elv_merge_requests(request_queue_t *, struct request *,
			       struct request *);
+extern void elv_extended_request(request_queue_t *, struct request *,
int, int);
extern void elv_merged_request(request_queue_t *, struct request *);
extern void elv_dequeue_request(request_queue_t *, struct request *);
extern void elv_requeue_request(request_queue_t *, struct request *);
-
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