ocfs2: do not return DLM_MIGRATE_RESPONSE_MASTERY_REF to avoid endless,loop during umount
The following case may lead to endless loop during umount.
node A node B node C node D
umount volume,
migrate lockres1
to B
want to lock lockres1,
send
MASTER_REQUEST_MSG
to C
init block mle
send
MIGRATE_REQUEST_MSG
to C
find a block
mle, and then
return
DLM_MIGRATE_RESPONSE_MASTERY_REF
to B
set C in refmap
umount successfully
try to umount, endless
loop occurs when migrate
lockres1 since C is in
refmap
So we can fix this endless loop case by only returning
DLM_MIGRATE_RESPONSE_MASTERY_REF if it has a mastery mle when receiving
MIGRATE_REQUEST_MSG.
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: jiangyiwen <jiangyiwen@huawei.com>
Reviewed-by: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Xue jiufei <xuejiufei@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/ocfs2/dlm/dlmmaster.c b/fs/ocfs2/dlm/dlmmaster.c
index 3087a21..4f4b00e 100644
--- a/fs/ocfs2/dlm/dlmmaster.c
+++ b/fs/ocfs2/dlm/dlmmaster.c
@@ -3088,11 +3088,15 @@
/* remove it so that only one mle will be found */
__dlm_unlink_mle(dlm, tmp);
__dlm_mle_detach_hb_events(dlm, tmp);
- ret = DLM_MIGRATE_RESPONSE_MASTERY_REF;
- mlog(0, "%s:%.*s: master=%u, newmaster=%u, "
- "telling master to get ref for cleared out mle "
- "during migration\n", dlm->name, namelen, name,
- master, new_master);
+ if (tmp->type == DLM_MLE_MASTER) {
+ ret = DLM_MIGRATE_RESPONSE_MASTERY_REF;
+ mlog(0, "%s:%.*s: master=%u, newmaster=%u, "
+ "telling master to get ref "
+ "for cleared out mle during "
+ "migration\n", dlm->name,
+ namelen, name, master,
+ new_master);
+ }
}
spin_unlock(&tmp->spinlock);
}
