On Sun, Jul 18, 2010 at 12:57:02AM -0400, Christoph Hellwig wrote:
> On Sun, Jul 18, 2010 at 11:20:33AM +1000, Dave Chinner wrote:
> > So, back to the situation with the WARN_ON(). You're running
> > applications that are doing something that:
> > a) is not supported;
> > b) compromises data integrity guarantees;
> > c) is not reliably reported; and
> > d) might be causing hangs
> > Right now I'm not particularly inclined to dig into this further;
> > it's obvious the applications are doing something that is not
> > supported (by XFS or the generic page cache code), so this is the
> > first thing you really need to care about getting fixed if you value
> > your backups...
> While it's slightly crazy it's also a pretty easy way for users to shoot
> themselve in their feet. Unlike the generic filesystems with their
> simplistic i_mutex locking we have a way to assure this works properly
> in XFS with the shared/exclusive iolock, so I'm willing to look into
> this further.
Sorry, that wasn't paticularly clear - What I was trying to say is
that I'm not really interested in solving all the generic
buffered/direct IO coherency issues. I agree that it should not
hang, so we do need to find out why it hung....