Re: [PATCH - resend] devtmpfs regression fix: reconfigure on each mount

[Greg Kroah-Hartman]

On Mon, Jan 17, 2022 at 09:07:26AM +1100, NeilBrown wrote:
> 
> Prior to Linux v5.4 devtmpfs used mount_single() which treats the given
> mount options as "remount" options, so it updates the configuration of the
> single super_block on each mount.
> Since that was changed, the mount options used for devtmpfs are ignored.
> This is a regression which affect systemd - which mounts devtmpfs
> with "-o mode=755,size=4m,nr_inodes=1m".
> 
> This patch restores the "remount" effect by calling reconfigure_single()
> 
> Fixes: d401727ea0d7 ("devtmpfs: don't mix {ramfs,shmem}_fill_super() with mount_single()")
> Acked-by: Christian Brauner <christian.brauner@xxxxxxxxxx>
> Signed-off-by: NeilBrown <neilb@xxxxxxx>
> ---
>  drivers/base/devtmpfs.c    | 7 +++++++
>  fs/super.c                 | 4 ++--
>  include/linux/fs_context.h | 2 ++
>  3 files changed, 11 insertions(+), 2 deletions(-)

Sorry, I thought Al was going to take this as the regression came from
his tree, I should have picked it up earlier.  I'll queue it up after
5.17-rc1 is out.

thanks,

greg k-h