Re: WARNING at fs/nfs/write.c:743 nfs_inode_remove_request with -rc6

[Weston Andros Adamson]

On Sep 23, 2014, at 11:02 AM, Weston Andros Adamson <dros@xxxxxxxxxxxxxxx> wrote:

> On Sep 23, 2014, at 10:59 AM, Weston Andros Adamson <dros@xxxxxxxxxxxxxxx> wrote:
> 
>> On Sep 23, 2014, at 10:53 AM, Will Deacon <will.deacon@xxxxxxx> wrote:
>> 
>>> On Tue, Sep 23, 2014 at 02:59:38PM +0100, Will Deacon wrote:
>>>> On Tue, Sep 23, 2014 at 02:33:06PM +0100, Weston Andros Adamson wrote:
>>>>> Any more info on how to reproduce this would be really great. Unfortunately I don’t
>>>>> have access to an arm64 system.
>>>> 
>>>> I've not spotted a pattern other than using 64k pages, yet. If I manage to
>>>> get a reproducer, I'll let you know.
>>>> 
>>>>> If it’s possible, could we get a packet trace around when this happens? This is pure
>>>>> speculation, but this might have something to do the resend path - a commit fails
>>>>> and all the requests on the commit list have to be resent.
>>>> 
>>>> Sure, once I can reproduce it reliably, then I'll try to do that.
>>> 
>>> Right, a bunch of DDing from /dev/zero over an ssh session triggers this
>>> very quickly. I've put a binary tcpdump here:
>>> 
>>> http://www.willdeacon.ukfsn.org/bitbucket/oopsen/nfs/tcpdump.bin
>>> 
>>> You may want to filter out the ssh packets. The only `interesting' thing to
>>> me is a retransmission about half way through, but I don't know what I'm
>>> looking for.
>>> 
>>> The NFS server is 10.1.203.204 and the client is 10.1.203.24.
>> 
>> Thanks! You are using NFSv2, so there are no commits - that rules out my hunch.
> 
> Wait a second - the whole point of this extra reference (that the WARN_ON_ONCE is
> related to) is to handle the pass off to commit lists.
> 
> Maybe I’m just doing the wrong thing here with NFSv2!
> 
> More soon.

Actually, can you see if this is reproducible with NFSv3?

Thanks,

-dros

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/