> On Dec 7, 2015, at 12:04 PM, Scott Mayhew <smayhew@xxxxxxxxxx> wrote:
>
> On Mon, 07 Dec 2015, Chuck Lever wrote:
>
>>
>>> On Dec 7, 2015, at 11:42 AM, Scott Mayhew <smayhew@xxxxxxxxxx> wrote:
>>>
>>> Certain name resolution misconfigurations (for example, a hosts file
>>> entry with an ip address but no hostnames) can cause get_nameinfo() to
>>> return an empty string in buf, which will lead to this cryptic failure:
>>>
>>> Dec 7 09:37:44 hostname rpc.statd[8024]: Failed to insert: creating
>>> /var/lib/nfs/statd/sm/: Is a directory
>>> Dec 7 09:37:44 hostname rpc.statd[8024]: STAT_FAIL to
>>> hostname.example.com for SM_MON of 192.168.1.2
>>> Dec 7 09:37:44 hostname kernel: lockd: cannot monitor 192.168.1.2
>>>
>>> It's better in that case to just go ahead and use the presentation
>>> address and log a more helpful warning:
>>
>> Doesn???t this change wire behavior? Some peers do not appreciate
>> receiving a presentation address, which is why statd/sm_notify
>> avoid sending them.
>
> I was just trying to keep it in line with the behavior you had added in
> e22f5a9c (statd: statd fails to monitor if no reverse mapping of mon_name
> exists). As it stands now, if get_nameinfo() fails outright then the
> presentation address is used and we're able to monitor the peer just
> fine... but get_nameinfo() succeeds and returns an empty hostname then
> we ultimately wind up failing to monitor the peer.
OK, I see the “bug-for-bug compatible” red flag in the
description of e22f5a9c. I guess this shouldn’t even
fire a warning then, it should just return the address.
We should correct the documenting comment for
statd_canonical_name(). Just delete the sentence that
begins “We won’t monitor peers”.
Reviewed-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
>> I think it would be better to _skip_ this address and print the
>> warning? IMO.
>>
> That's actually what I had at first and if you think that's better then
> that's fine too. The rest of the errors would still get logged then,
> but at least the reason would be a little more apparent.
>
> -Scott
>>
>>> Dec 7 10:24:52 hostname rpc.statd[14224]: get_nameinfo returned empty
>>> hostname for 10.10.183.219. Fix your name resolution!
>>>
>>> Signed-off-by: Scott Mayhew <smayhew@xxxxxxxxxx>
>>> ---
>>> utils/statd/hostname.c | 6 ++++++
>>> 1 file changed, 6 insertions(+)
>>>
>>> diff --git a/utils/statd/hostname.c b/utils/statd/hostname.c
>>> index c61087c..86d11ca 100644
>>> --- a/utils/statd/hostname.c
>>> +++ b/utils/statd/hostname.c
>>> @@ -211,6 +211,12 @@ statd_canonical_name(const char *hostname)
>>> /* OK to use presentation address,
>>> * if no reverse map exists */
>>> return strdup(hostname);
>>> + else if (buf[0] == '\0') {
>>> + xlog_warn("get_nameinfo returned empty hostname for "
>>> + "%s. Fix your name resolution!",
>>> + hostname);
>>> + return strdup(hostname);
>>> + }
>>> return strdup(buf);
>>> }
>>>
>>> --
>>> 2.4.3
>>>
>>> --
>>> To unsubscribe from this list: send the line "unsubscribe linux-nfs" in
>>> the body of a message to majordomo@xxxxxxxxxxxxxxx
>>> More majordomo info at http://vger.kernel.org/majordomo-info.html
>>
>> --
>> Chuck Lever
>>
>>
>>
>>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-nfs" in
> the body of a message to majordomo@xxxxxxxxxxxxxxx
> More majordomo info at http://vger.kernel.org/majordomo-info.html
--
Chuck Lever
--
To unsubscribe from this list: send the line "unsubscribe linux-nfs" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
