Revert "Move xen patchset to new version's subdir."

[ipfire-2.x.git] / src / patches / suse-2.6.27.31 / patches.drivers / block-add-timeout-on-dequeue

diff --git a/src/patches/suse-2.6.27.31/patches.drivers/block-add-timeout-on-dequeue b/src/patches/suse-2.6.27.31/patches.drivers/block-add-timeout-on-dequeue
deleted file mode 100644 (file)
index 401d571..0000000
--- a/src/patches/suse-2.6.27.31/patches.drivers/block-add-timeout-on-dequeue
+++ /dev/null
@@ -1,70 +0,0 @@
-From: Tejun Heo <tj@kernel.org>
-Subject: block: add timer on blkdev_dequeue_request() not elv_next_request()
-References: bnc#440076
-
-Block queue supports two usage models - one where block driver peeks
-at the front of queue using elv_next_request(), processes it and
-finishes it and the other where block driver peeks at the front of
-queue, dequeue the request using blkdev_dequeue_request() and finishes
-it.  The latter is more flexible as it allows the driver to process
-multiple commands concurrently.
-
-These two inconsistent usage models affect the block layer
-implementation confusing.  For some, elv_next_request() is considered
-the issue point while others consider blkdev_dequeue_request() the
-issue point.
-
-Till now the inconsistency mostly affect only accounting, so it didn't
-really break anything seriously; however, with block layer timeout,
-this inconsistency hits hard.  Block layer considers
-elv_next_request() the issue point and adds timer but SCSI layer
-thinks it was just peeking and when the request can't process the
-command right away, it's just left there without further processing.
-This makes the request dangling on the timer list and, when the timer
-goes off, the request which the SCSI layer and below think is still on
-the block queue ends up in the EH queue, causing various problems - EH
-hang (failed count goes over busy count and EH never wakes up),
-WARN_ON() and oopses as low level driver trying to handle the unknown
-command, etc. depending on the timing.
-
-As SCSI midlayer is the only user of block layer timer at the moment,
-moving blk_add_timer() to elv_dequeue_request() fixes the problem;
-however, this two usage models definitely need to be cleaned up in the
-future.
-
-Signed-off-by: Tejun Heo <tj@kernel.org>
-Signed-off-by: Tejun Heo <teheo@suse.de>
----
- block/elevator.c |   12 ++++++------
- 1 file changed, 6 insertions(+), 6 deletions(-)
-
-Index: linux-2.6.27/block/elevator.c
-===================================================================
---- linux-2.6.27.orig/block/elevator.c
-+++ linux-2.6.27/block/elevator.c
-@@ -773,12 +773,6 @@ struct request *elv_next_request(struct
-                        */
-                       rq->cmd_flags |= REQ_STARTED;
-                       blk_add_trace_rq(q, rq, BLK_TA_ISSUE);
--
--                      /*
--                       * We are now handing the request to the hardware,
--                       * add the timeout handler
--                       */
--                      blk_add_timer(rq);
-               }
- 
-               if (!q->boundary_rq || q->boundary_rq == rq) {
-@@ -850,6 +844,12 @@ void elv_dequeue_request(struct request_
-        */
-       if (blk_account_rq(rq))
-               q->in_flight++;
-+
-+      /*
-+       * We are now handing the request to the hardware, add the
-+       * timeout handler.
-+       */
-+      blk_add_timer(rq);
- }
- EXPORT_SYMBOL(elv_dequeue_request);
-