Re: [vfs] WARNING: CPU: 3 PID: 2339 at mm/truncate.c:758 pagecache_isize_extended+0xdd/0x120()

[Dave Chinner <david@fromorbit.com>]

On Mon, Oct 27, 2014 at 10:58:12AM +0100, Jan Kara wrote:
> On Mon 27-10-14 12:04:22, Dave Chinner wrote:
> > On Thu, Oct 16, 2014 at 01:01:27PM +0200, Jan Kara wrote:
> > > From de3426d6495f4b44b14c09b7c7202e9a86d864b9 Mon Sep 17 00:00:00 2001
> > > From: Jan Kara <jack@suse.cz>
> > > Date: Thu, 16 Oct 2014 12:58:42 +0200
> > > Subject: [PATCH] mm: Remove false WARN_ON from pagecache_isize_extended()
> > > 
> > > The WARN_ON checking whether i_mutex is held in
> > > pagecache_isize_extended() was wrong because some filesystems (e.g.
> > > XFS) use different locks for serialization of truncates / writes. So
> > > just remove the check.
> > > 
> > > Signed-off-by: Jan Kara <jack@suse.cz>
> > > ---
> > >  mm/truncate.c | 1 -
> > >  1 file changed, 1 deletion(-)
> > > 
> > > diff --git a/mm/truncate.c b/mm/truncate.c
> > > index 261eaf6e5a19..c646084e5eec 100644
> > > --- a/mm/truncate.c
> > > +++ b/mm/truncate.c
> > > @@ -755,7 +755,6 @@ void pagecache_isize_extended(struct inode *inode, loff_t from, loff_t to)
> > >  	struct page *page;
> > >  	pgoff_t index;
> > >  
> > > -	WARN_ON(!mutex_is_locked(&inode->i_mutex));
> > >  	WARN_ON(to > inode->i_size);
> > >  
> > >  	if (from >= to || bsize == PAGE_CACHE_SIZE)
> > 
> > Jan, Have you sent this patch upstream yet? I'm seeing it fire in
> > my testing in 3.18-rc1 kernels, so I was wondering what your plans
> > are for this...
>   I did send it but it got lost somewhere. I'll resend it.

If it comes to it, I can push it through the XFS tree - I've got a
few patches I need to send for -rc3...

Cheers,

Dave.
-- 
Dave Chinner
david@fromorbit.com