xfs: stop the sync worker before xfs_unmountfs

[Ben Myers]

On Thu, Sep 13, 2012 at 04:17:42AM -0400, Christoph Hellwig wrote:
> On Wed, Sep 12, 2012 at 01:33:47PM -0500, Ben Myers wrote:
> > See what you think of this.  Not heavily tested yet, and not pretty... but it
> > is fairly minimal. 
> > 
> > Pull startup and shutdown of the sync worker out of xfs_syncd_init and
> > xfs_syncd_stop into their callers.  In the case of unmount, move shutdown of
> > the xfs_sync_worker before teardown of the log in xfs_unmountfs.  This prevents
> > occasional crashes on unmount like so:
> > 
> > PID: 21602  TASK: ee9df060  CPU: 0   COMMAND: "kworker/0:3"                                                                                                                               
> >  #0 [c5377d28] crash_kexec at c0292c94                                                                                                                                                    
> 
> Can you remove the trailing whitespaces in these lines?  They make
> reading the changelog on a normal 80 character wide terminal pretty
> hard.

Yeah.  Sorry about that.  Cleaned up.

> The changes look fine to me,
> 
> 
> Reviewed-by: Christoph Hellwig <hch at lst.de>

Thanks,
	Ben