Re: Stale file not being refreshed automatically?

[Nathan March <nathan@gt.net>]

Awesome, I'll see about a perl equiv. Thanks again!

- Nathan

On 1/25/2011 2:48 PM, Trond Myklebust wrote:
> On Tue, 2011-01-25 at 14:38 -0800, Nathan March wrote:
>> Ah ha, yes, it's using a stat call.
>>
>> What would be the proper C call to check the file exists without
>> incurring the stat()?
> access("file", F_OK) should do it.
>
> Cheers
>    Trond
>
>> On 1/25/2011 2:28 PM, Trond Myklebust wrote:
>>> On Tue, 2011-01-25 at 14:11 -0800, Nathan March wrote:
>>>> Hi All,
>>>>
>>>> Having a strange issue, I've reproduced this both on nfs 3 and 4.
>>>> Currently using v4 with:
>>>>
>>>> exports:
>>>> /var/home/voyage
>>>> 10.2.1.0/24(rw,fsid=0,async,wdelay,secure,no_subtree_check,anonuid=1000,anongid=1006)
>>>>
>>>> fstab:
>>>> 10.2.1.1:/ /mnt/voyage nfs4
>>>> rsize=32768,wsize=32768,noatime,nosuid,rw,bg,hard,intr 0 0
>>>>
>>>> Can be produced using these two commands on 2 machines:
>>>>
>>>> perl -le '$| = 1 ; while (1) { sleep 1; $res = -e "/home/voyage/test";
>>>> if ($res) { print "-e : $res"; } else { print "-e : $res ($!)"; } }'
>>>> -e : 1
>>>>
>>>> perl -le '$| = 1 ; while (1) { sleep 5; open(F, ">",
>>>> "/home/voyage/test.foo"); close F; my $res =
>>>> rename("/home/voyage/test.foo", "/home/voyage/test"); print "rename
>>>> ($res)"; }'
>>>>
>>>> The first command will occasionally print out: -e :  (Stale NFS file handle)
>>>>
>>>> Now according to http://nfs.sourceforge.net/#faq_a10 as of 2.6.12 the
>>>> vfs should automatically retry when it gets a estale during path
>>>> resolution. This doesn't appear to be happening though based on the
>>>> errors I'm seeing.
>>>>
>>>> Anyone have any thoughts on what might be happening here? Or am I
>>>> misinterpreting that faq entry? (This is on ext3 if it matters)
>>> Does '-e' in perl only do a lookup, or does it result in a 'stat()'
>>> call? If the latter, then your test is flawed: a stat() is a lookup+a
>>> getattr, and the latter can definitely return ESTALE when you are
>>> constantly replacing the file.
>>>
>>> Cheers
>>>     Trond