[PATCH] fs: push i_mutex and filemap_write_and_wait down into ->fsync() handlers

[Christoph Hellwig]

On Sun, Jul 24, 2011 at 07:16:26AM -0400, Christoph Hellwig wrote:
> On Sun, Jul 24, 2011 at 12:02:12AM +0200, Markus Trippelsdorf wrote:
> > The following patch fixes the problem for me:
> 
> Good catch, can you send it with a proper signoff and description?

This also fixes the xfstests 130 regression that popped up in latest
Linus HEAD.  Good to know we have some QA coverage for O_SYNC writes,
althoug I wish it would be more than just one testcase..