On 07/14/2017 01:51 AM, NeilBrown wrote:
> Please try this (against a clean nfs-utils.  i.e. remove the previous
> patch).
> It is a hack and would need to be totally re-written, but hopely the
> measurements you make and strace that you report could be useful.
> Also, for the strace, please use "-ttt" rather than "-tt" like I asked
> before.  It is easier to find the difference between two times with
> -ttt. And add -T as well.

Sorry this took so long but I had to be sure of my results.

With your latest patch applied I am unable to mount my NFS shares and 
thus continue with the tests from before.

Since the patch you provided cannot be applied cleanly to the source 
used to build '1:1.2.8-9ubuntu12.1' for Ubuntu Xenial I chose to build a 
couple of VMs to continue this testing. They should be identical to the 
machines I was using before except they are under powered and not using 
nfs-common, nfs-kernel-server package version 1:1.2.8-9ubuntu12.1. Most 
importantly the zfs datasets and the files in /etc/exports.d are the same.

I found that utils/mountd/cache.c was last modified in 1.3.4, so I 
tested both 1.3.4 and 2.1.1 without your patch as a baseline. I was able 
to mount my shares in both versions.

I then reverted my VMs to a state before the baseline install and 
installed again with your patch applied.

I get the following with your patch applied on 1.3.4 and 2.1.1:

root@nfsclient:~# mount -avv
/                        : ignored
/boot                    : already mounted
none                     : ignored
mount.nfs4: timeout set for Tue Jul 25 15:43:13 2017
mount.nfs4: trying text-based options 
'ac,hard,rsize=16384,wsize=16384,vers=4.2,addr=10.135.24.23,clientaddr=10.135.24.22'
mount.nfs4: mount(2): No such file or directory
mount.nfs4: trying text-based options 
'ac,hard,rsize=16384,wsize=16384,addr=10.135.24.23'
mount.nfs4: prog 100003, trying vers=3, prot=6
mount.nfs4: trying 10.135.24.23 prog 100003 vers 3 prot TCP port 2049
mount.nfs4: prog 100005, trying vers=3, prot=17
mount.nfs4: trying 10.135.24.23 prog 100005 vers 3 prot UDP port 41598
mount.nfs4: mount(2): Permission denied
mount.nfs4: access denied by server while mounting 
nfsserver.cs.uchicago.edu:/homes
mount.nfs4: timeout set for Tue Jul 25 15:43:14 2017
mount.nfs4: trying text-based options 
'ac,hard,rsize=16384,wsize=16384,vers=4.2,addr=10.135.24.23,clientaddr=10.135.24.22'
mount.nfs4: mount(2): No such file or directory
mount.nfs4: trying text-based options 
'ac,hard,rsize=16384,wsize=16384,addr=10.135.24.23'
mount.nfs4: prog 100003, trying vers=3, prot=6
mount.nfs4: trying 10.135.24.23 prog 100003 vers 3 prot TCP port 2049
mount.nfs4: prog 100005, trying vers=3, prot=17
mount.nfs4: trying 10.135.24.23 prog 100005 vers 3 prot UDP port 41598
mount.nfs4: mount(2): Permission denied
mount.nfs4: access denied by server while mounting 
nfsserver.cs.uchicago.edu:/stage


Attached are my install notes and the strace during the failed mount above.




-- 
Phil Kauffman
Systems Admin
Dept. of Computer Science
University of Chicago
kauffman@cs.uchicago.edu