On 25/10/13 07:43, Jeff Layton wrote: > On Thu, 24 Oct 2013 15:45:03 -0400 > Steve Dickson <SteveD@xxxxxxxxxx> wrote: > >> >> >> On 24/10/13 14:45, Jeff Layton wrote: >>> On Thu, 24 Oct 2013 14:17:10 -0400 >>> Steve Dickson <steved@xxxxxxxxxx> wrote: >>> >>>> [ Here is the second try for these patches incorporating the code review..] >>>> >>>> Recently it was pointed out to me that the [-n | --no-tcp] flags >>>> were broken in mountd. Sure enough they are and they broke >>>> when nfs-utils moved to using libtirpc, which was years ago. >>>> >>>> Obviously nobody is using these flags since has not been >>>> notice until now, but it seemed to me it no longer makes >>>> any sense to have flags. We really want people to use TCP >>>> so why should there be a way to turn it off? It should be >>>> the opposite... They should be able to turn off UDP listeners >>>> not TCP... >>>> >>>> >>>> Steve Dickson (3): >>>> mountd: Use protocol bit fields to turn protocols off. >>>> mountd: Deprecate the ability to disable TCP listeners. >>>> mountd: Add the ability to disable UDP listeners. >>>> >>>> support/include/rpcmisc.h | 2 +- >>>> support/nfs/rpcmisc.c | 19 ++++++++++++++----- >>>> support/nfs/svc_create.c | 5 +++++ >>>> utils/mountd/mountd.c | 17 ++++++++++++----- >>>> utils/mountd/mountd.man | 6 +++--- >>>> 5 files changed, 35 insertions(+), 14 deletions(-) >>>> >>> >>> Sorry I'm coming in late on this... >> np... I was expecting more push back! ;-) >> >>> >>> I don't think we want to remove the ability to disable TCP listeners. >>> >>> Why, you ask? We've been on a multi-year effort to move people to >>> NFSv4, and with that, there's no reason to have mountd listen on the >>> network at all. >> True... >> >>> >>> So personally, I think it would make sense to: >>> >>> a) allow people to disable listening on UDP in addition to TCP >> I see no reason whatsoever to turn off TCP listeners especially >> since that is the protocol of choice... something we have >> be spouting about for years... >> > > There are reasons to be able to turn off TCP listeners: > > If you're running a NFSv4-only server, there's no reason to allow it to > listen on TCP _or_ UDP sockets. I think that sort of environment is > going to become more prevalent in the future, not less. I ideally it would be best not to have mountd at all on NFSv4-only server. Basically, have the kernel get its exports like it gets it ID mappings. Until that day comes, which I hope fill be soon, the TCP listener only effects v3 mounts and we definitely want people to use TCP with v3. > >>> >>> ...or... >>> >>> b) add an option that prevents it from listening on any sockets for a >>> v4-only configuration >> In this case it would optimal to not even start mountd, unfortunately >> due to exports reasons, it not possible... but it should be!! :-) >> > > Right, mountd has 2 jobs: > > 1) respond to MNT protocol requests from clients > > ...and... > > 2) feed exports info to the kernel > > For v4, you obviously don't need the first role, so being able to > disable network listeners is a good thing in such a configuration. Again, I would rather build an v4 only environment where mountd does not even run... steved. > >>> >>> In addition, we generally do want people to use UDP for the MNT >>> protocol because it's less apt to cause issues with reserved port >>> exhaustion. Given that it'll continue to listen on a UDP socket by >>> default, that last point is less of an issue, but that might be a good >>> reason to rethink this whole plan. >>> >> I did think of this.... UDP is on by default... Is up the admin... >> > > That's good. I have no objection to adding an option to disable UDP > listeners if the admin chooses. I just think it would be best to fix > the ability to disable TCP listeners as well instead of removing it. > -- 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
