Re: can't dump core on NFSv4 mounts

[David Flynn <davidf@rd.bbc.co.uk>]

* David Flynn (davidf@rd.bbc.co.uk) wrote:
> On an NFS4 client (mounting a solaris ufs export), for a long time i've
> been experiencing vim complaining when exiting:
>   E137: Viminfo file is not writable: /home/davidf/.viminfo

A similar and possibly related fault that I'm seeing is the inability
for a process to dump a core file when it segfaults on an nfs4 mount.

If the filesystem is mounted nfs3, then this issue does not arise.

using:
  $ echo 'int main() {return *(int*)0;}' >segfault.c

on an nfs4 mount:
  host-a$ ~/segfault
  Segmentation fault
  host-a$ ls -l
  total 1
  -rw------- 1 4294967294 4294967294 0 2010-12-08 15:34 core

a remote system shows:
  host-b$ ls -l
  total 1
  -rw------- 1 davidf rd 0 Dec  8 15:34 core

waiting for the dust to settle:
  host-a$ ls -l
  total 1
  -rw------- 1 davidf rd 0 2010-12-08 15:34 core

Iff, the core file already exists, then the core dump succeeds:
  host-a$ touch core
  host-a$ ls -l
  total 1
  -rw------- 1 davidf rd 0 2010-12-08 15:42 core
  host-a$ ~/segfault
  Segmentation fault (core dumped)

I can reliably reproduce using 2.6.32.11 and 2.6.35
I can not reproduce on 2.6.26

Kind regards,

..david