linux-kernel - Re: [PATCH v4 2/2] FUSE: Retire superblock on force unmount

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CAONX=-faZGmOe_=y_kG=erkQOR6fYdwXuF0HoFJVwMUdemxk0g@mail.gmail.com>
Date:   Wed, 13 Jul 2022 08:24:11 +1000
From:   Daniil Lunev <dlunev@...omium.org>
To:     miklos@...redi.hu
Cc:     linux-kernel@...r.kernel.org, fuse-devel@...ts.sourceforge.net,
        Daniil Lunev <dlunev@...gle.com>,
        linux-fsdevel@...r.kernel.org, viro@...iv.linux.org.uk,
        hch@...radead.org, tytso@....edu
Subject: Re: [PATCH v4 2/2] FUSE: Retire superblock on force unmount

Hi Miklos,
Can you please take a look at the current patchset and see if you are
ok with it?
Thanks,
Daniil

On Wed, Jun 1, 2022 at 11:11 AM Daniil Lunev <dlunev@...omium.org> wrote:
>
> From: Daniil Lunev <dlunev@...omium.org>
>
> Force unmount of FUSE severes the connection with the user space, even
> if there are still open files. Subsequent remount tries to re-use the
> superblock held by the open files, which is meaningless in the FUSE case
> after disconnect - reused super block doesn't have userspace counterpart
> attached to it and is incapable of doing any IO.
>
> Signed-off-by: Daniil Lunev <dlunev@...omium.org>
>
> Signed-off-by: Daniil Lunev <dlunev@...gle.com>
> ---
>
> (no changes since v3)
>
> Changes in v3:
> - No changes
>
> Changes in v2:
> - Use an exported function instead of directly modifying superblock
>
>  fs/fuse/inode.c | 7 +++++--
>  1 file changed, 5 insertions(+), 2 deletions(-)
>
> diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c
> index 8c0665c5dff88..8875361544b2a 100644
> --- a/fs/fuse/inode.c
> +++ b/fs/fuse/inode.c
> @@ -476,8 +476,11 @@ static void fuse_umount_begin(struct super_block *sb)
>  {
>         struct fuse_conn *fc = get_fuse_conn_super(sb);
>
> -       if (!fc->no_force_umount)
> -               fuse_abort_conn(fc);
> +       if (fc->no_force_umount)
> +               return;
> +
> +       fuse_abort_conn(fc);
> +       retire_super(sb);
>  }
>
>  static void fuse_send_destroy(struct fuse_mount *fm)
> --
> 2.31.0
>