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authorTejun Heo <tj@kernel.org>2008-12-03 12:41:26 +0100
committerJens Axboe <jens.axboe@oracle.com>2008-12-03 12:41:26 +0100
commit53a08807c01989c6847bb135d8d43f61c5dfdda5 (patch)
treee2297de901dc82a0336e6af28b594864792c585d /block
parentbf91db18ac2852a3ff39fe25ff56c5557c0fff78 (diff)
downloadconfigs-53a08807c01989c6847bb135d8d43f61c5dfdda5.tar.gz
block: internal dequeue shouldn't start timer
blkdev_dequeue_request() and elv_dequeue_request() are equivalent and both start the timeout timer. Barrier code dequeues the original barrier request but doesn't passes the request itself to lower level driver, only broken down proxy requests; however, as the original barrier code goes through the same dequeue path and timeout timer is started on it. If barrier sequence takes long enough, this timer expires but the low level driver has no idea about this request and oops follows. Timeout timer shouldn't have been started on the original barrier request as it never goes through actual IO. This patch unexports elv_dequeue_request(), which has no external user anyway, and makes it operate on elevator proper w/o adding the timer and make blkdev_dequeue_request() call elv_dequeue_request() and add timer. Internal users which don't pass the request to driver - barrier code and end_that_request_last() - are converted to use elv_dequeue_request(). Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Mike Anderson <andmike@linux.vnet.ibm.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Diffstat (limited to 'block')
-rw-r--r--block/blk-barrier.c4
-rw-r--r--block/blk-core.c24
-rw-r--r--block/elevator.c7
3 files changed, 25 insertions, 10 deletions
diff --git a/block/blk-barrier.c b/block/blk-barrier.c
index 5c99ff8d2db..6e72d661ae4 100644
--- a/block/blk-barrier.c
+++ b/block/blk-barrier.c
@@ -161,7 +161,7 @@ static inline struct request *start_ordered(struct request_queue *q,
/*
* Prep proxy barrier request.
*/
- blkdev_dequeue_request(rq);
+ elv_dequeue_request(q, rq);
q->orig_bar_rq = rq;
rq = &q->bar_rq;
blk_rq_init(q, rq);
@@ -219,7 +219,7 @@ int blk_do_ordered(struct request_queue *q, struct request **rqp)
* This can happen when the queue switches to
* ORDERED_NONE while this request is on it.
*/
- blkdev_dequeue_request(rq);
+ elv_dequeue_request(q, rq);
if (__blk_end_request(rq, -EOPNOTSUPP,
blk_rq_bytes(rq)))
BUG();
diff --git a/block/blk-core.c b/block/blk-core.c
index 10e8a64a5a5..7a779d7c69c 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -1637,6 +1637,28 @@ int blk_insert_cloned_request(struct request_queue *q, struct request *rq)
EXPORT_SYMBOL_GPL(blk_insert_cloned_request);
/**
+ * blkdev_dequeue_request - dequeue request and start timeout timer
+ * @req: request to dequeue
+ *
+ * Dequeue @req and start timeout timer on it. This hands off the
+ * request to the driver.
+ *
+ * Block internal functions which don't want to start timer should
+ * call elv_dequeue_request().
+ */
+void blkdev_dequeue_request(struct request *req)
+{
+ elv_dequeue_request(req->q, req);
+
+ /*
+ * We are now handing the request to the hardware, add the
+ * timeout handler.
+ */
+ blk_add_timer(req);
+}
+EXPORT_SYMBOL(blkdev_dequeue_request);
+
+/**
* __end_that_request_first - end I/O on a request
* @req: the request being processed
* @error: %0 for success, < %0 for error
@@ -1774,7 +1796,7 @@ static void end_that_request_last(struct request *req, int error)
blk_queue_end_tag(req->q, req);
if (blk_queued_rq(req))
- blkdev_dequeue_request(req);
+ elv_dequeue_request(req->q, req);
if (unlikely(laptop_mode) && blk_fs_request(req))
laptop_io_completion();
diff --git a/block/elevator.c b/block/elevator.c
index 9ac82dde99d..a6951f76ba0 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -844,14 +844,7 @@ void elv_dequeue_request(struct request_queue *q, struct request *rq)
*/
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);
int elv_queue_empty(struct request_queue *q)
{