path: root/block
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authorJeff Moyer <>2011-10-17 12:57:23 +0200
committerGreg Kroah-Hartman <>2011-11-11 09:44:36 -0800
commite94d1d00463f6fdcef956828ff698a2bce3f7a8f (patch)
tree711c335eda09b34a63e7ff3969c79710ce68ffde /block
parentd16a63a89dcb0cece02469b3bb17062c3d48656f (diff)
blk-flush: move the queue kick into
commit e67b77c791ca2778198c9e7088f3266ed2da7a55 upstream. 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] Reported-by: Christophe Saout <> Signed-off-by: Jeff Moyer <> Acked-by: Tejun Heo <> Signed-off-by: Jens Axboe <> Signed-off-by: Greg Kroah-Hartman <>
Diffstat (limited to 'block')
2 files changed, 2 insertions, 1 deletions
diff --git a/block/blk-core.c b/block/blk-core.c
index d34433ae7917..795154e54a75 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)
add_acct_request(q, rq, where);
+ __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 89ae3b9bf7ca..720ad607ff91 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) &&
list_add_tail(&rq->queuelist, &q->queue_head);
- blk_run_queue_async(q);