Re: Wrong DIF guard tag on ext2 write

[Christof Schmitt <christof.schmitt@de.ibm.com>]

On Mon, Jun 07, 2010 at 01:40:21PM -0400, Martin K. Petersen wrote:
> >>>>> "Boaz" == Boaz Harrosh <bharrosh@panasas.com> writes:
> 
> Boaz> Do you remember some performance numbers that show degradation /
> Boaz> sameness?
> 
> Boaz> What type of work loads?
> 
> I haven't been using XFS much for over a year.  I'm using an internal
> async I/O tool and btrfs for most of my DIX/DIF testing these days.
> 
> But my original changes were along the lines of what Jan mentioned
> earlier (hooking into page_mkwrite and waiting for writeback.  I could
> have sworn that I only did it for ext[23] and that XFS waited out of the
> box but git proves me wrong).  Anyway, I'll try to get some benchmarking
> happening later this week.

Is there a patch with this change available somewhere? It might be
useful to patch a kernel with this XFS change for reliable DIF/DIX
testing.

> This won't fix things completely, though.  ext2fs, for instance,
> frequently changes metadata buffers in flight so it trips the guard
> check in no time.
> 
> -- 
> Martin K. Petersen	Oracle Linux Engineering
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