[PATCH] kill-the-bkl/reiserfs: fix early readdir offset increment

[Frederic Weisbecker]

On Mon, Aug 03, 2009 at 09:26:59AM -0400, Chris Mason wrote:
> Definitely, the cost of the rare bug is much higher.  The good news is
> that reiserfs tends to pile its races into a few spots.  Most of them
> can be found with a 12 hour run of the namesys stress.sh program and a
> lot of memory pressure.  I'd compile with preemption on and you'll have
> a good test on any SMP machine.
> 
> http://oss.oracle.com/~mason/stress.sh
> 
> stress.sh just copies a source directory into the test filesystem, then
> reads it  back and deletes it in a loop.  I'd run with 50 procs and
> enough memory  pressure for the box to lightly swap (booting w/mem= is a
> fine way to make memory pressure).  This way you make sure to hammer on
> the metadata writeback paths, which is where all of the difficult races
> come in.
> 
> Testing with an fsx-linux process running at the same time will make
> sure all of the mmap/truncate paths are working correctly as well.
> 
> -chris
> 


Running this script has unearthed a bug introduced in my last commit.
This is fixed in the patch below.
Thanks for this script, I'm now running it very often, only on PREEMPT UP
for now.

---