[Pvfs2-developers] dbench and pvfs2_bufmap race

[Phil Carns]

I captured a log file (attached) of both pvfs2-client and the kernel 
module after running this:

<mount pvfs2>
cd /mnt/pvfs2
mv dir/file1 dir/file2

The ncache and acache are both disabled in pvfs2-client to try to 
simplify the scenario.

I tried to get syslog to sync enough to get both pvfs2.ko and 
pvfs2-client-core messages chronologically in the same file, but it 
didn't really work out.  They are jumbled together in an odd order.

It's probably less confusing to just grep each one out like this if 
anyone wants to have a look at what's going on:

# for kernel module messages:
grep "kernel: " mv-bug.log

# for pvfs2-client messages:
grep "PVFS2: \[D\]" mv-bug.log

-Phil

Phil Carns wrote:
> It looks like dbench is hanging on a rename of a file within a 
> subdirectory.  I can replicate it outside of dbench like this:
> 
>   root@(none):/mnt/pvfs2# pwd
>   /mnt/pvfs2
>   root@(none):/mnt/pvfs2# mkdir testdir
>   root@(none):/mnt/pvfs2# touch testdir/foo
>   root@(none):/mnt/pvfs2# mv testdir/foo testdir/bar
> 
> Everything works fine if I instead try to rename something with no 
> subdirectory:
> 
>   root@(none):/mnt/pvfs2# touch foo
>   root@(none):/mnt/pvfs2# mv foo bar                  # so far so good
> 
> I don't think the "mkdir" and "touch" steps are relevant other than just 
> for an example.  I think get the same hang if the file and subdir 
> already exist when pvfs is mounted.
> 
> -Phil


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