[Ocfs2-devel] [PATCH] ocfs2: optimize error handling in dlm_request_join

[Norton.Zhu <norton.zhu@huawei.com>]

Hi Srinivas,
Thanks for your advice, we should leave *response as JOIN_DISALLOW if packet.code is
invalid, I will resend the patch.

On 2015/8/21 0:56, Srinivas Eeda wrote:
> On 08/20/2015 04:50 AM, Norton.Zhu wrote:
>> Currently error handling in dlm_request_join is a little obscure.
>> So optimize it to promote readability.
>>
>> Signed-off-by: Norton.Zhu <norton.zhu@huawei.com>
>> ---
>>   fs/ocfs2/dlm/dlmdomain.c | 69 ++++++++++++++++++++++++++----------------------
>>   1 file changed, 37 insertions(+), 32 deletions(-)
>>
>> diff --git a/fs/ocfs2/dlm/dlmdomain.c b/fs/ocfs2/dlm/dlmdomain.c
>> index 7df88a6..af4f7aa 100644
>> --- a/fs/ocfs2/dlm/dlmdomain.c
>> +++ b/fs/ocfs2/dlm/dlmdomain.c
>> @@ -1465,39 +1465,44 @@ 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;
> Norton, it looks much better :)
> 
> one minor comment. we don't want to reset "*response" with packet.code if it's unrecognized. We should leave the value to JOIN_DISALLOW;
> 
> rest looks good.
> 
>> +        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);
>> +            break;
>> +        }
>>       }
>>
>>       mlog(0, "status %d, node %d response is %d\n", status, node,
> 
> 
> .
>