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author | Roman Gushchin <klamm@yandex-team.ru> | 2015-10-31 02:53:50 +0300 |
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committer | Sasha Levin <sasha.levin@oracle.com> | 2015-11-15 20:51:53 +0300 |
commit | 0ac9586cd0477c6ed1e4bb6c9b0b18503e25f6f5 (patch) | |
tree | 1e135cce0d8882cb49c98ce756f3040529e7c447 /drivers/tty | |
parent | 69a7ca06041ad6f3a7672db472ac26cdd2a3df83 (diff) | |
download | linux-0ac9586cd0477c6ed1e4bb6c9b0b18503e25f6f5.tar.xz |
md/raid5: fix locking in handle_stripe_clean_event()
[ Upstream commit b8a9d66d043ffac116100775a469f05f5158c16f ]
After commit 566c09c53455 ("raid5: relieve lock contention in get_active_stripe()")
__find_stripe() is called under conf->hash_locks + hash.
But handle_stripe_clean_event() calls remove_hash() under
conf->device_lock.
Under some cirscumstances the hash chain can be circuited,
and we get an infinite loop with disabled interrupts and locked hash
lock in __find_stripe(). This leads to hard lockup on multiple CPUs
and following system crash.
I was able to reproduce this behavior on raid6 over 6 ssd disks.
The devices_handle_discard_safely option should be set to enable trim
support. The following script was used:
for i in `seq 1 32`; do
dd if=/dev/zero of=large$i bs=10M count=100 &
done
neilb: original was against a 3.x kernel. I forward-ported
to 4.3-rc. This verison is suitable for any kernel since
Commit: 59fc630b8b5f ("RAID5: batch adjacent full stripe write")
(v4.1+). I'll post a version for earlier kernels to stable.
Signed-off-by: Roman Gushchin <klamm@yandex-team.ru>
Fixes: 566c09c53455 ("raid5: relieve lock contention in get_active_stripe()")
Signed-off-by: NeilBrown <neilb@suse.com>
Cc: Shaohua Li <shli@kernel.org>
Cc: <stable@vger.kernel.org> # 3.13 - 4.2
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Diffstat (limited to 'drivers/tty')
0 files changed, 0 insertions, 0 deletions