Re: [PATCH 15/14] xfs: capture inode generation numbers in the ondisk exchmaps log item

["Darrick J. Wong" <djwong@kernel.org>]

On Wed, Apr 10, 2024 at 06:00:58AM +0200, Christoph Hellwig wrote:
> On Tue, Apr 09, 2024 at 05:05:28PM -0700, Darrick J. Wong wrote:
> > From: Darrick J. Wong <djwong@kernel.org>
> > 
> > Per some very late review comments, capture the generation numbers of
> > both inodes involved in a file content exchange operation so that we
> > don't accidentally target files with have been reallocated.
> > 
> > Signed-off-by: Darrick J. Wong <djwong@kernel.org>
> > ---
> > I'm throwing this one on the pile since I guess it's not so hard to add
> > the generation number to a brand new log item.
> 
> It does looks fine to me, but it leaves the question open:  why here
> and not elsewhere.  And the answer based on the previous discussions
> is that this is the first new log item after the problem was known
> and we'll need to eventually rev the other ino based items as well.
> Maybe capture this in a comment?

	/*
	 * This log intent item targets inodes, which means that it effectively
	 * contains a file handle.  Check that the generation numbers match the
	 * intent item like we do for other file handles.  This is the first
	 * new log intent item to be defined after this validation weakness was
	 * identified, which is why recovery for other items do not check this.
	 */

How about that?

--D