Zachary Hays c4609e81e0 mmc: block: handle complete_work on separate workqueue ... commit dcf6e2e38a upstream. The kblockd workqueue is created with the WQ_MEM_RECLAIM flag set. This generates a rescuer thread for that queue that will trigger when the CPU is under heavy load and collect the uncompleted work. In the case of mmc, this creates the possibility of a deadlock when there are multiple partitions on the device as other blk-mq work is also run on the same queue. For example: - worker 0 claims the mmc host to work on partition 1 - worker 1 attempts to claim the host for partition 2 but has to wait for worker 0 to finish - worker 0 schedules complete_work to release the host - rescuer thread is triggered after time-out and collects the dangling work - rescuer thread attempts to complete the work in order starting with claim host - the task to release host is now blocked by a task to claim it and will never be called The above results in multiple hung tasks that lead to failures to mount partitions. Handling complete_work on a separate workqueue avoids this by keeping the work completion tasks separate from the other blk-mq work. This allows the host to be released without getting blocked by other tasks attempting to claim the host. Signed-off-by: Zachary Hays <zhays@lexmark.com> Fixes: 81196976ed ("mmc: block: Add blk-mq support") Cc: <stable@vger.kernel.org> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2019-02-20 10:25:46 +01:00
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acpi
asm-generic	mm: introduce mm_[p4d|pud|pmd]_folded	2018-12-29 13:37:58 +01:00
clocksource
crypto	crypto: speck - remove Speck	2018-11-13 11:08:46 -08:00
drm	drm: Get ref on CRTC commit object when waiting for flip_done	2018-10-18 14:23:13 -04:00
dt-bindings	ARM: SoC: late updates	2018-08-25 14:12:36 -07:00
keys
kvm
linux	mmc: block: handle complete_work on separate workqueue	2019-02-20 10:25:46 +01:00
math-emu
media	media: cec: keep track of outstanding transmits	2019-01-09 17:38:46 +01:00
memory
misc
net	ipvlan, l3mdev: fix broken l3s mode wrt local routes	2019-02-06 17:30:06 +01:00
pcmcia
ras
rdma	IB/rxe: Revise the ib_wr_opcode enum	2018-11-13 11:08:43 -08:00
scsi
soc	soc: fsl: qbman: add APIs to retrieve the probing status	2018-09-27 15:43:35 -05:00
sound	ALSA: compress: Fix stop handling on compressed capture streams	2019-02-12 19:47:23 +01:00
target	scsi: target/core: Make sure that target_wait_for_sess_cmds() waits long enough	2019-01-26 09:32:38 +01:00
trace	sunrpc: use-after-free in svc_process_common()	2019-01-16 22:04:37 +01:00
uapi	Input: input_event - fix the CONFIG_SPARC64 mixup	2019-01-31 08:14:42 +01:00
video	fbdev changes for v4.19:	2018-08-23 15:44:58 -07:00
xen	Revert "xen/balloon: Mark unallocated host memory as UNUSABLE"	2018-12-17 09:24:39 +01:00