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authorYufen Yu <yuyufen@huawei.com>2019-04-24 18:19:05 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-09-16 09:22:12 +0300
commit69409854ba08d3aeb28a3989703381857842e2ab (patch)
tree451393411a5a9230d437b9e8388d742fc7c84bb7 /include
parent0fe097012b6ca7d5103eb6905ff6a2b640c78f67 (diff)
downloadlinux-69409854ba08d3aeb28a3989703381857842e2ab.tar.xz
dm mpath: fix missing call of path selector type->end_io
[ Upstream commit 5de719e3d01b4abe0de0d7b857148a880ff2a90b ] After commit 396eaf21ee17 ("blk-mq: improve DM's blk-mq IO merging via blk_insert_cloned_request feedback"), map_request() will requeue the tio when issued clone request return BLK_STS_RESOURCE or BLK_STS_DEV_RESOURCE. Thus, if device driver status is error, a tio may be requeued multiple times until the return value is not DM_MAPIO_REQUEUE. That means type->start_io may be called multiple times, while type->end_io is only called when IO complete. In fact, even without commit 396eaf21ee17, setup_clone() failure can also cause tio requeue and associated missed call to type->end_io. The service-time path selector selects path based on in_flight_size, which is increased by st_start_io() and decreased by st_end_io(). Missed calls to st_end_io() can lead to in_flight_size count error and will cause the selector to make the wrong choice. In addition, queue-length path selector will also be affected. To fix the problem, call type->end_io in ->release_clone_rq before tio requeue. map_info is passed to ->release_clone_rq() for map_request() error path that result in requeue. Fixes: 396eaf21ee17 ("blk-mq: improve DM's blk-mq IO merging via blk_insert_cloned_request feedback") Cc: stable@vger.kernl.org Signed-off-by: Yufen Yu <yuyufen@huawei.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'include')
-rw-r--r--include/linux/device-mapper.h3
1 files changed, 2 insertions, 1 deletions
diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h
index bef2e36c01b4..91f9f95ad506 100644
--- a/include/linux/device-mapper.h
+++ b/include/linux/device-mapper.h
@@ -62,7 +62,8 @@ typedef int (*dm_clone_and_map_request_fn) (struct dm_target *ti,
struct request *rq,
union map_info *map_context,
struct request **clone);
-typedef void (*dm_release_clone_request_fn) (struct request *clone);
+typedef void (*dm_release_clone_request_fn) (struct request *clone,
+ union map_info *map_context);
/*
* Returns: