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| author | Yu Kuai <yukuai3@huawei.com> | 2023-06-21 22:29:33 +0800 |
|---|---|---|
| committer | Song Liu <song@kernel.org> | 2023-06-23 09:41:47 -0700 |
| commit | 4934b6401a812f9fe368e7d2d091cd1d120ea262 (patch) | |
| tree | 6396b4d2209a4229b8357a11c78aaafcb3512072 /drivers/md/md.h | |
| parent | a1d7671910965ca9f8f0377e7e3bfd1179fba4d8 (diff) | |
| download | linux-4934b6401a812f9fe368e7d2d091cd1d120ea262.tar.gz linux-4934b6401a812f9fe368e7d2d091cd1d120ea262.tar.bz2 linux-4934b6401a812f9fe368e7d2d091cd1d120ea262.zip | |
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/md/md.h')
| -rw-r--r-- | drivers/md/md.h | 4 |
1 files changed, 1 insertions, 3 deletions
diff --git a/drivers/md/md.h b/drivers/md/md.h index bfd2306bc750..1aef86bf3fc3 100644 --- a/drivers/md/md.h +++ b/drivers/md/md.h @@ -531,11 +531,9 @@ struct mddev { /* * Temporarily store rdev that will be finally removed when - * reconfig_mutex is unlocked. + * reconfig_mutex is unlocked, protected by reconfig_mutex. */ struct list_head deleting; - /* Protect the deleting list */ - struct mutex delete_mutex; bool has_superblocks:1; bool fail_last_dev:1; |