Date: Mon, 24 Feb 2014 08:36:06 +1100
From: Dave Chinner <david@fromorbit.com>
To: "Theodore Ts'o" <tytso@mit.edu>, Namjae Jeon <linkinjeon@gmail.com>,
        viro@zeniv.linux.org.uk, bpm@sgi.com, adilger.kernel@dilger.ca,
        jack@suse.cz, mtk.manpages@gmail.com, lczerner@redhat.com,
        linux-fsdevel@vger.kernel.org, xfs@oss.sgi.com,
        linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org,
        Namjae Jeon <namjae.jeon@samsung.com>,
        Ashish Sangwan <a.sangwan@samsung.com>
Subject: Re: [PATCH v5 1/10] fs: Add new flag(FALLOC_FL_COLLAPSE_RANGE) for
 fallocate
Message-ID: <20140223213606.GE4317@dastard>
References: <1392741464-20029-1-git-send-email-linkinjeon@gmail.com>
 <20140222140625.GD26637@thunk.org>
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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@fromorbit.com
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