Re: [PATCH] sysv: Remove the filesystem

Bill O'Donnell
2025-01-09T23:09:02Z

On Thu, Jan 09, 2025 at 04:05:13PM +0100, Christian Brauner wrote:
> On Wed, Jan 08, 2025 at 04:32:55PM -0600, Bill O'Donnell wrote:
> > On Tue, Jan 07, 2025 at 03:35:35PM +0100, Christian Brauner wrote:
> > > On Mon, Jan 06, 2025 at 05:24:01PM +0100, Jan Kara wrote:
> > > > Since 2002 (change "Replace BKL for chain locking with sysvfs-private
> > > > rwlock") the sysv filesystem was doing IO under a rwlock in its
> > > > get_block() function (yes, a non-sleepable lock hold over a function
> > > > used to read inode metadata for all reads and writes). Nobody noticed
> > > > until syzbot in 2023 [1]. This shows nobody is using the filesystem.
> > > > Just drop it.
> > > >
> > > > [1] https://lore.kernel.org/all/0000000000000ccf9a05ee84f5b0@google.com/
> > > >
> > > > Signed-off-by: Jan Kara <jack@suse.cz>
> > > > ---
> > > > What do people think about this? Or should we perhaps go through a (short)
> > > > deprecation period where we warn about removal?
> > >
> > > Let's try and kill it. We can always put it back if we have to.
> > >
> > So should any work toward converting sysv to the new mount API stop? ;)
>
> So I would suggest we try and remove it for v6.15. If the removal
> survives the release of v6.16 I would call it a (qualified) success.
>
> If during this time we find out that we have to keep it and have to
> reintroduce it then we may as well spend the time to port it to the new
> mount api.
>
> Thoughts?
Makes sense to me.