dlm_do_local_recovery_cleanup() should force clean refmap if the owner of
lockres is UNKNOWN. Otherwise node may hang when umounting filesystems.
Here's the situation:
Node1 Node2
dlmlock()
-> dlm_get_lock_resource()
send DLM_MASTER_REQUEST_MSG to
other nodes.
trying to master this lockres,
return MAYBE.
selected as the master of lockresA,
set mle->master to Node1,
and do assert_master,
send DLM_ASSERT_MASTER_MSG to Node2.
Node 2 has interest on lockresA
and return
DLM_ASSERT_RESPONSE_MASTERY_REF
then something happened and
Node2 crashed.
Receiving DLM_ASSERT_RESPONSE_MASTERY_REF, set Node2 into refmap, and keep
sending DLM_ASSERT_MASTER_MSG to other nodes
o2hb found node2 down, calling dlm_hb_node_down() -->
dlm_do_local_recovery_cleanup() the master of lockresA is still UNKNOWN,
no need to call dlm_free_dead_locks().
Set the master of lockresA to Node1, but Node2 stills remains in refmap.
When Node1 umount, it found that the refmap of lockresA is not empty and
attempted to migrate it to Node2, But Node2 is already down, so umount
hang, trying to migrate lockresA again and again.
Signed-off-by: joyce <xuejiufei@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Jie Liu <jeff.liu@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
69b2bd16d9