linux-stable/include
Yufen Yu 5de719e3d0 dm mpath: fix missing call of path selector type->end_io
After commit 396eaf21ee ("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 396eaf21ee, 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: 396eaf21ee ("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>
2019-04-25 15:38:52 -04:00
..
acpi ACPI: use different default debug value than ACPICA 2019-03-25 10:45:59 +01:00
asm-generic syscalls: Remove start and number from syscall_set_arguments() args 2019-04-05 09:27:23 -04:00
clocksource
crypto
drm drm/atomic-helper: Make atomic_enable/disable crtc callbacks optional 2019-03-29 11:56:52 +01:00
dt-bindings dt-bindings: reset: meson-g12a: Add missing USB2 PHY resets 2019-03-25 16:22:10 +01:00
keys KEYS: trusted: fix -Wvarags warning 2019-04-08 15:58:54 -07:00
kvm ARM: some cleanups, direct physical timer assignment, cache sanitization 2019-03-15 15:00:28 -07:00
linux dm mpath: fix missing call of path selector type->end_io 2019-04-25 15:38:52 -04:00
math-emu
media
memory
misc auxdisplay: charlcd: Introduce charlcd_free() helper 2019-03-17 08:48:16 +01:00
net nfc: nci: Potential off by one in ->pipes[] array 2019-04-06 15:05:07 -07:00
pcmcia
ras
rdma
scsi
soc IOMMU Updates for Linux v5.1 2019-03-10 12:29:52 -07:00
sound ASoC: core: conditionally increase module refcount on component open 2019-04-08 14:15:44 +07:00
target
trace syscalls: Remove start and number from syscall_get_arguments() args 2019-04-05 09:26:43 -04:00
uapi sound fixes for 5.1-rc5 2019-04-12 08:11:59 -07:00
video media updates for v5.1-rc1 2019-03-09 14:45:54 -08:00
xen