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Date:   Mon, 17 Jan 2022 09:04:16 +0100
From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     NeilBrown <neilb@suse.de>
Cc:     Al Viro <viro@zeniv.linux.org.uk>,
        Andrew Morton <akpm@linux-foundation.org>,
        torvalds@linux-foundation.org,
        Christian Brauner <christian.brauner@ubuntu.com>,
        Anthony Iliopoulos <ailiop@suse.com>,
        David Howells <dhowells@redhat.com>,
        LKML <linux-kernel@vger.kernel.org>,
        linux-fsdevel@vger.kernel.org
Subject: Re: [PATCH - resend] devtmpfs regression fix: reconfigure on each
 mount
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On Mon, Jan 17, 2022 at 09:03:58AM +0100, Greg Kroah-Hartman wrote:
> 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@ubuntu.com>
> > Signed-off-by: NeilBrown <neilb@suse.de>
> > ---
> >  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.

Ah, nevermind, Linus just took it.

thanks,

greg k-h