Revision 645efa84f6c7566ea863ed37a8b3247247f72e02 authored by Mikulas Patocka on 05 February 2019, 10:09:00 UTC, committed by Mike Snitzer on 06 February 2019, 22:24:37 UTC
Block core changes to switch bio-based IO accounting to be percpu had a
side-effect of altering DM core to now rely on calling waitqueue_active
(in both bio-based and request-based) to check if another task is in
dm_wait_for_completion().

A memory barrier is needed before calling waitqueue_active().  DM core
doesn't piggyback on a preceding memory barrier so it must explicitly
use its own.

For more details on why using waitqueue_active() without a preceding
barrier is unsafe, please see the comment before the waitqueue_active()
definition in include/linux/wait.h.

Add the missing memory barrier by switching to using wq_has_sleeper().

Fixes: 6f75723190d8 ("dm: remove the pending IO accounting")
Fixes: c4576aed8d85 ("dm: fix request-based dm's use of dm_wait_for_completion")
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
1 parent 8834f56
History
File Mode Size
apparmor
integrity
keys
loadpin
selinux
smack
tomoyo
yama
Kconfig -rw-r--r-- 9.8 KB
Makefile -rw-r--r-- 1.0 KB
commoncap.c -rw-r--r-- 38.9 KB
device_cgroup.c -rw-r--r-- 20.4 KB
inode.c -rw-r--r-- 10.5 KB
lsm_audit.c -rw-r--r-- 10.6 KB
min_addr.c -rw-r--r-- 1.3 KB
security.c -rw-r--r-- 45.7 KB

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