Hi,
在 2023/06/28 9:07, Yu Kuai 写道:
From: Yu Kuai <yukuai3@xxxxxxxxxx>
Changes in v2:
- remove a now unused local variable in patch 2;
Commit b13015af94cf ("md/raid5-cache: Clear conf->log after finishing
work") introduce a new problem:
// caller hold reconfig_mutex
r5l_exit_log
flush_work(&log->disable_writeback_work)
r5c_disable_writeback_async
wait_event
/*
* conf->log is not NULL, and mddev_trylock()
* will fail, wait_event() can never pass.
*/
conf->log = NULL
patch 1 revert this patch, an patch 2 fix the original problem in a
different way.
Noted this problem is just found by code review, and I think this is
probably the reason that some mdadm tests is broken.
Any suggestions?
By the way, while taking another look at this problem, I think probably
read and write 'conf->log' should use READ_ONCE and WRITE_ONCE.
Thanks,
Kuai
Yu Kuai (2):
md/raid5-cache: Revert "md/raid5-cache: Clear conf->log after
finishing work"
md/raid5-cache: fix null-ptr-deref in r5l_reclaim_thread()
drivers/md/raid5-cache.c | 25 ++++++++++---------------
1 file changed, 10 insertions(+), 15 deletions(-)
