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author | Yu Kuai <yukuai3@huawei.com> | 2023-06-21 22:29:33 +0800 |
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committer | Song Liu <song@kernel.org> | 2023-06-23 09:41:47 -0700 |
commit | 4934b6401a812f9fe368e7d2d091cd1d120ea262 (patch) | |
tree | 6396b4d2209a4229b8357a11c78aaafcb3512072 /drivers/xen/mcelog.c | |
parent | a1d7671910965ca9f8f0377e7e3bfd1179fba4d8 (diff) |
md: fix 'delete_mutex' deadlock
Commit 3ce94ce5d05a ("md: fix duplicate filename for rdev") introduce a
new lock 'delete_mutex', and trigger a new deadlock:
t1: remove rdev t2: sysfs writer
rdev_attr_store rdev_attr_store
mddev_lock
state_store
md_kick_rdev_from_array
lock delete_mutex
list_add mddev->deleting
unlock delete_mutex
mddev_unlock
mddev_lock
...
lock delete_mutex
kobject_del
// wait for sysfs writers to be done
mddev_unlock
lock delete_mutex
// wait for delete_mutex, deadlock
'delete_mutex' is used to protect the list 'mddev->deleting', turns out
that this list can be protected by 'reconfig_mutex' directly, and this
lock can be removed.
Fix this problem by removing the lock, and use 'reconfig_mutex' to
protect the list. mddev_unlock() will move this list to a local list to
be handled after 'reconfig_mutex' is dropped.
Fixes: 3ce94ce5d05a ("md: fix duplicate filename for rdev")
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20230621142933.1395629-1-yukuai1@huaweicloud.com
Diffstat (limited to 'drivers/xen/mcelog.c')
0 files changed, 0 insertions, 0 deletions