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| author | Jeff Moyer <jmoyer@redhat.com> | 2011-10-17 12:57:23 +0200 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2011-10-24 16:24:31 +0200 |
| commit | e67b77c791ca2778198c9e7088f3266ed2da7a55 (patch) | |
| tree | 9c65ce6b5679d1f45fa1e4720430ea17b11fa2aa | |
| parent | 834f9f61a525d2f6d3d0c93894e26326c8d3ceed (diff) | |
| download | op-kernel-dev-e67b77c791ca2778198c9e7088f3266ed2da7a55.zip op-kernel-dev-e67b77c791ca2778198c9e7088f3266ed2da7a55.tar.gz | |
blk-flush: move the queue kick into
A dm-multipath user reported[1] a problem when trying to boot
a kernel with commit 4853abaae7e4a2af938115ce9071ef8684fb7af4
(block: fix flush machinery for stacking drivers with differring
flush flags) applied. It turns out that an empty flush request
can be sent into blk_insert_flush. When the BUG_ON was fixed
to allow for this, I/O on the underlying device would stall. The
reason is that blk_insert_cloned_request does not kick the queue.
In the aforementioned commit, I had added a special case to
kick the queue if data was sent down but the queue flags did
not require a flush. A better solution is to push the queue
kick up into blk_insert_cloned_request.
This patch, along with a follow-on which fixes the BUG_ON, fixes
the issue reported.
[1] http://www.redhat.com/archives/dm-devel/2011-September/msg00154.html
Reported-by: Christophe Saout <christophe@saout.de>
Signed-off-by: Jeff Moyer <jmoyer@redhat.com>
Acked-by: Tejun Heo <tj@kernel.org>
Stable note: 3.1
Cc: stable@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
| -rw-r--r-- | block/blk-core.c | 2 | ||||
| -rw-r--r-- | block/blk-flush.c | 1 |
2 files changed, 2 insertions, 1 deletions
diff --git a/block/blk-core.c b/block/blk-core.c index d34433a..795154e 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -1725,6 +1725,8 @@ int blk_insert_cloned_request(struct request_queue *q, struct request *rq) where = ELEVATOR_INSERT_FLUSH; add_acct_request(q, rq, where); + if (where == ELEVATOR_INSERT_FLUSH) + __blk_run_queue(q); spin_unlock_irqrestore(q->queue_lock, flags); return 0; diff --git a/block/blk-flush.c b/block/blk-flush.c index 89ae3b9..720ad60 100644 --- a/block/blk-flush.c +++ b/block/blk-flush.c @@ -330,7 +330,6 @@ void blk_insert_flush(struct request *rq) if ((policy & REQ_FSEQ_DATA) && !(policy & (REQ_FSEQ_PREFLUSH | REQ_FSEQ_POSTFLUSH))) { list_add_tail(&rq->queuelist, &q->queue_head); - blk_run_queue_async(q); return; } |
