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Xue jiufei authored
We found a race between purge and migration when doing code review. Node A put lockres to purgelist before receiving the migrate message from node B which is the master. Node A call dlm_mig_lockres_handler to handle this message. dlm_mig_lockres_handler dlm_lookup_lockres >>>>>> race window, dlm_run_purge_list may run and send deref message to master, waiting the response spin_lock(&res->spinlock); res->state |= DLM_LOCK_RES_MIGRATING; spin_unlock(&res->spinlock); dlm_mig_lockres_handler returns >>>>>> dlm_thread receives the response from master for the deref message and triggers the BUG because the lockres has the state DLM_LOCK_RES_MIGRATING with the following message: dlm_purge_lockres:209 ERROR: 6633EB681FA7474A9C280A4E1A836F0F: res M0000000000000000030c0300000000 in use after deref Signed-off-by:
Jiufei Xue <xuejiufei@huawei.com> Reviewed-by:
Joseph Qi <joseph.qi@huawei.com> Reviewed-by:
Yiwen Jiang <jiangyiwen@huawei.com> Cc: Mark Fasheh <mfasheh@suse.de> Cc: Joel Becker <jlbec@evilplan.org> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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