Re: [PATCH 4/8] cifs: Fix creating NFS-style char/block devices

[Steve French]

Looks like a duplicate of Paulo's earlier already merged patch, so
will skip this one.  Reviewing the others in the series now.

commit a9de67336a4aa3ff2e706ba023fb5f7ff681a954
Author: Paulo Alcantara <pc@xxxxxxxxxxxxx>
Date:   Wed Sep 18 21:53:35 2024 -0300

    smb: client: set correct device number on nfs reparse points

    Fix major and minor numbers set on special files created with NFS
    reparse points.

On Sat, Sep 28, 2024 at 5:02 PM Pali Rohár <pali@xxxxxxxxxx> wrote:
>
> Linux SMB client currently creates NFS-style char and block devices with
> swapped major and minor numbers.
>
> Per MS-FSCC 2.1.2.6 NFS_SPECFILE_CHR and NFS_SPECFILE_BLK DataBuffer's
> field contains two 32-bit integers that represent major and minor device
> numbers.
>
> So the first one 32-bit integer in DataBuffer is major number and second
> one in DataBuffer is minor number. Microsoft Windows NFS server reads them
> in this order too.
>
> But Linux CIFS client creates new reparse point DataBuffer with minor
> number first and major number second.
>
> Fix this problem in Linux SMB client and puts major and minor number in
> the correct order into DataBuffer.
>
> This change fixes interoperability of char and block devices on Windows
> share which is exported over both SMB and NFS protocols.
>
> Fixes: 102466f303ff ("smb: client: allow creating special files via reparse points")
> Signed-off-by: Pali Rohár <pali@xxxxxxxxxx>
> ---
>  fs/smb/client/reparse.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/fs/smb/client/reparse.c b/fs/smb/client/reparse.c
> index 48c27581ec51..63984796721a 100644
> --- a/fs/smb/client/reparse.c
> +++ b/fs/smb/client/reparse.c
> @@ -108,8 +108,8 @@ static int nfs_set_reparse_buf(struct reparse_posix_data *buf,
>         buf->InodeType = cpu_to_le64(type);
>         buf->ReparseDataLength = cpu_to_le16(len + dlen -
>                                              sizeof(struct reparse_data_buffer));
> -       *(__le64 *)buf->DataBuffer = cpu_to_le64(((u64)MAJOR(dev) << 32) |
> -                                                MINOR(dev));
> +       *(__le64 *)buf->DataBuffer = cpu_to_le64(((u64)MINOR(dev) << 32) |
> +                                                MAJOR(dev));
>         iov->iov_base = buf;
>         iov->iov_len = len + dlen;
>         return 0;
> --
> 2.20.1
>
>


-- 
Thanks,

Steve