Re: [PATCH] overlayfs: set ctime when setting mtime and atime

[Amir Goldstein]

On Fri, Sep 22, 2023 at 4:52 PM Jeff Layton <jlayton@xxxxxxxxxx> wrote:
>
> On Thu, 2023-09-14 at 10:39 +0200, Christian Brauner wrote:
> > On Wed, 13 Sep 2023 09:33:12 -0400, Jeff Layton wrote:
> > > Nathan reported that he was seeing the new warning in
> > > setattr_copy_mgtime pop when starting podman containers. Overlayfs is
> > > trying to set the atime and mtime via notify_change without also
> > > setting the ctime.
> > >
> > > POSIX states that when the atime and mtime are updated via utimes() that
> > > we must also update the ctime to the current time. The situation with
> > > overlayfs copy-up is analogies, so add ATTR_CTIME to the bitmask.
> > > notify_change will fill in the value.
> > >
> > > [...]
> >
> > Applied to the vfs.ctime branch of the vfs/vfs.git tree.
> > Patches in the vfs.ctime branch should appear in linux-next soon.
> >
> > Please report any outstanding bugs that were missed during review in a
> > new review to the original patch series allowing us to drop it.
> >
> > It's encouraged to provide Acked-bys and Reviewed-bys even though the
> > patch has now been applied. If possible patch trailers will be updated.
> >
> > Note that commit hashes shown below are subject to change due to rebase,
> > trailer updates or similar. If in doubt, please check the listed branch.
> >
> > tree:   https://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs.git
> > branch: vfs.ctime
> >
> > [1/1] overlayfs: set ctime when setting mtime and atime
> >       https://git.kernel.org/vfs/vfs/c/f8edd3368615
>
> Christian, are you still planning to pick up this patch? I saw that it
> was dropped from linux-next. Since the mgtime patches have been reverted
> for now, it may be best for this to go in via the overlayfs tree ?

I think this is a long standing overlayfs bug fix, so it should go into 6.6
and not wait for 6.7 anyway.
Also need to add CC stable (don't think we need to bother with Fixes).

I do not have any overlayfs fixes queued ATM.
Christian, if you have any pening VFS fixes, you may send it along with them
or we could just ask Linus to apply this one directly, so that any mgtime
changes that may still happen for 6.7 will already have this fluke fixed.

Thanks,
Amir.