Re: [PATCH v5 1/10] fs: Add new flag(FALLOC_FL_COLLAPSE_RANGE) for fallocate

[Dave Chinner <david@xxxxxxxxxxxxx>]

On Sat, Feb 22, 2014 at 09:06:25AM -0500, Theodore Ts'o wrote:
> On Wed, Feb 19, 2014 at 01:37:43AM +0900, Namjae Jeon wrote:
> > +   /*
> > +    * There is no need to overlap collapse range with EOF, in which case
> > +    * it is effectively a truncate operation
> > +    */
> > +   if ((mode & FALLOC_FL_COLLAPSE_RANGE) &&
> > +       (offset + len >= i_size_read(inode)))
> > +           return -EINVAL;
> > +
> 
> I wonder if we should just translate a collapse range that is
> equivalent to a truncate operation to, in fact, be a truncate
> operation?

Trying to collapse a range that extends beyond EOF, IMO, is likely
to only happen if the DVR/NLE application is buggy. Hence I think
that telling the application it is doing something that is likely to
be wrong is better than silently truncating the file....

Cheers,

Dave.
-- 
Dave Chinner
david@xxxxxxxxxxxxx