ocfs2: optimize error handling in dlm_request_join

Currently error handling in dlm_request_join is a little obscure, so
optimize it to promote readability.

If packet.code is invalid, reset it to JOIN_DISALLOW to keep it
meaningful.  It only influences the log printing.

Signed-off-by: Norton.Zhu <norton.zhu@huawei.com>
Cc: Srinivas Eeda <srinivas.eeda@oracle.com>
Reviewed-by: 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>

diff --git a/fs/ocfs2/dlm/dlmdomain.c b/fs/ocfs2/dlm/dlmdomain.c
index 019459b20aeb84fd218fc04a46fa2030441b183a..6918f30d02cd7631634804389ce0f3deade524e2 100644 (file)
--- a/fs/ocfs2/dlm/dlmdomain.c
+++ b/fs/ocfs2/dlm/dlmdomain.c
@@ -1465,39 +1465,46 @@ static int dlm_request_join(struct dlm_ctxt *dlm,
        if (status == -ENOPROTOOPT) {
                status = 0;
                *response = JOIN_OK_NO_MAP;
-       } else if (packet.code == JOIN_DISALLOW ||
-                  packet.code == JOIN_OK_NO_MAP) {
-               *response = packet.code;
-       } else if (packet.code == JOIN_PROTOCOL_MISMATCH) {
-               mlog(ML_NOTICE,
-                    "This node requested DLM locking protocol %u.%u and "
-                    "filesystem locking protocol %u.%u.  At least one of "
-                    "the protocol versions on node %d is not compatible, "
-                    "disconnecting\n",
-                    dlm->dlm_locking_proto.pv_major,
-                    dlm->dlm_locking_proto.pv_minor,
-                    dlm->fs_locking_proto.pv_major,
-                    dlm->fs_locking_proto.pv_minor,
-                    node);
-               status = -EPROTO;
-               *response = packet.code;
-       } else if (packet.code == JOIN_OK) {
-               *response = packet.code;
-               /* Use the same locking protocol as the remote node */
-               dlm->dlm_locking_proto.pv_minor = packet.dlm_minor;
-               dlm->fs_locking_proto.pv_minor = packet.fs_minor;
-               mlog(0,
-                    "Node %d responds JOIN_OK with DLM locking protocol "
-                    "%u.%u and fs locking protocol %u.%u\n",
-                    node,
-                    dlm->dlm_locking_proto.pv_major,
-                    dlm->dlm_locking_proto.pv_minor,
-                    dlm->fs_locking_proto.pv_major,
-                    dlm->fs_locking_proto.pv_minor);
        } else {
-               status = -EINVAL;
-               mlog(ML_ERROR, "invalid response %d from node %u\n",
-                    packet.code, node);
+               *response = packet.code;
+               switch (packet.code) {
+               case JOIN_DISALLOW:
+               case JOIN_OK_NO_MAP:
+                       break;
+               case JOIN_PROTOCOL_MISMATCH:
+                       mlog(ML_NOTICE,
+                            "This node requested DLM locking protocol %u.%u and "
+                            "filesystem locking protocol %u.%u.  At least one of "
+                            "the protocol versions on node %d is not compatible, "
+                            "disconnecting\n",
+                            dlm->dlm_locking_proto.pv_major,
+                            dlm->dlm_locking_proto.pv_minor,
+                            dlm->fs_locking_proto.pv_major,
+                            dlm->fs_locking_proto.pv_minor,
+                            node);
+                       status = -EPROTO;
+                       break;
+               case JOIN_OK:
+                       /* Use the same locking protocol as the remote node */
+                       dlm->dlm_locking_proto.pv_minor = packet.dlm_minor;
+                       dlm->fs_locking_proto.pv_minor = packet.fs_minor;
+                       mlog(0,
+                            "Node %d responds JOIN_OK with DLM locking protocol "
+                            "%u.%u and fs locking protocol %u.%u\n",
+                            node,
+                            dlm->dlm_locking_proto.pv_major,
+                            dlm->dlm_locking_proto.pv_minor,
+                            dlm->fs_locking_proto.pv_major,
+                            dlm->fs_locking_proto.pv_minor);
+                       break;
+               default:
+                       status = -EINVAL;
+                       mlog(ML_ERROR, "invalid response %d from node %u\n",
+                            packet.code, node);
+                       /* Reset response to JOIN_DISALLOW */
+                       *response = JOIN_DISALLOW;
+                       break;
+               }
        }
 
        mlog(0, "status %d, node %d response is %d\n", status, node,