[Gluster-users] file corruption on Gluster 3.5.1 and Ubuntu 14.04

[mike]

I have narrowed down the source of the bug. 

Here is an strace of glusterfsd http://fpaste.org/131455/40996378/

The first line represents a write that does *not* make it into the underlying file.

The last line is the write that stomps the earlier write.

As I said, the client file is opened in O_APPEND mode, but on the glusterfsd side, the file is just O_CREAT|O_WRONLY. The means the offsets to pwrite() need to be valid.

I correlated this to a tcpdump I took and I can see that in fact, the RPCs being sent have the wrong offset.  Interestingly, glusterfs.write-is-append = 0, which I wouldn't have expected.

I think the bug lies in the glusterfs fuse client.

As to your question about Gluster 3.5.2, I may be able to do that if I am unable to find the bug in the source.

-Mike

On Sep 5, 2014, at 6:16 PM, Justin Clift <justin at gluster.org> wrote:

> On 06/09/2014, at 12:10 AM, mike wrote:
>> I have found that the O_APPEND flag is key to this failure - I had overlooked that flag when reading the strace and trying to cobble up a minimal reproduction.
>> 
>> I now have a small pair of python scripts that can reliably reproduce this failure.
> 
> 
> As a thought, is there a reasonable way you can test this on GlusterFS 3.5.2?
> 
> There were some important bug fixes in 3.5.2 (from 3.5.1).
> 
> Note I'm not saying yours is one of them, I'm just asking if it's
> easy to test and find out. :)
> 
> Regards and best wishes,
> 
> Justin Clift
> 
> --
> GlusterFS - http://www.gluster.org
> 
> An open source, distributed file system scaling to several
> petabytes, and handling thousands of clients.
> 
> My personal twitter: twitter.com/realjustinclift
>