Re: [PATCH] fs: make block fiemap mapping length at least blocksize long

[Andrew Morton <akpm@linux-foundation.org>]

On Tue, 01 Feb 2011 11:46:50 +0000
Steven Whitehouse <swhiteho@redhat.com> wrote:

> On Wed, 2010-12-08 at 12:03 -0500, Josef Bacik wrote:
> > Some filesystems don't deal well with being asked to map less than blocksize
> > blocks (GFS2 for example).  Since we are always mapping at least blocksize
> > sections anyway, just make sure len is at least as big as a blocksize so we
> > don't trip up any filesystems.  Thanks,
> > 
> > Signed-off-by: Josef Bacik <josef@redhat.com>
> > ---
> >  fs/ioctl.c |    7 +++++++
> >  1 files changed, 7 insertions(+), 0 deletions(-)
> > 
> > diff --git a/fs/ioctl.c b/fs/ioctl.c
> > index d6cc164..6b53c24 100644
> > --- a/fs/ioctl.c
> > +++ b/fs/ioctl.c
> > @@ -273,6 +273,13 @@ int __generic_block_fiemap(struct inode *inode,
> >  		len = isize;
> >  	}
> >  
> > +	/*
> > +	 * Some filesystems can't deal with being asked to map less than
> > +	 * blocksize, so make sure our len is at least block length.
> > +	 */
> > +	if (logical_to_blk(inode, len) == 0)
> > +		len = blk_to_logical(inode, 1);
> > +
> >  	start_blk = logical_to_blk(inode, start);
> >  	last_blk = logical_to_blk(inode, start + len - 1);
> >  

(top-posting repaired)

> Hi,
> 
> Is there any reason this cannot be sent to Linus now?
> 

I sent it to viro a couple of weeks back and it was ignored.  I don't
know why this happens :(