Function dlm_grab() may return NULL when the node is doing unmount.
When doing code review, we found that some dlm handlers may return
error to caller when dlm_grab() returns NULL and make caller
BUG or other problems. Here is an example:
Node 1 Node 2
receives migration message
from node 3, and send
migrate request to others
start unmounting
receives migrate request
from node 1 and call
dlm_migrate_request_handler()
unmount thread unregisters
domain handlers and removes
dlm_context from dlm_domains
dlm_migrate_request_handlers()
returns -EINVAL to node 1
Exit migration neither clearing the
migration state nor sending
assert master message to node 3 which
cause node 3 hung.
Signed-off-by: Jiufei Xue <xuejiu...@huawei.com>
Reviewed-by: Joseph Qi <joseph...@huawei.com>
Reviewed-by: Yiwen Jiang <jiangyi...@huawei.com>
---
fs/ocfs2/dlm/dlmmaster.c | 2 +-
fs/ocfs2/dlm/dlmunlock.c | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/fs/ocfs2/dlm/dlmmaster.c b/fs/ocfs2/dlm/dlmmaster.c
index ce38b4c..c43da7f 100644
--- a/fs/ocfs2/dlm/dlmmaster.c
+++ b/fs/ocfs2/dlm/dlmmaster.c
@@ -3048,7 +3048,7 @@ int dlm_migrate_request_handler(struct o2net_msg *msg,
u32 len, void *data,
int ret = 0;
if (!dlm_grab(dlm))
- return -EINVAL;
+ return 0;
name = migrate->name;
namelen = migrate->namelen;
diff --git a/fs/ocfs2/dlm/dlmunlock.c b/fs/ocfs2/dlm/dlmunlock.c
index 2e3c9db..1082b2c 100644
--- a/fs/ocfs2/dlm/dlmunlock.c
+++ b/fs/ocfs2/dlm/dlmunlock.c
@@ -421,7 +421,7 @@ int dlm_unlock_lock_handler(struct o2net_msg *msg, u32 len,
void *data,
}
if (!dlm_grab(dlm))
- return DLM_REJECTED;
+ return DLM_FORWARD;
mlog_bug_on_msg(!dlm_domain_fully_joined(dlm),
"Domain %s not fully joined!\n", dlm->name);
--
1.8.4.3
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