Paulo, please look at this patch as it is related to WSL attributes
which you introduced in the mentioned commit. I think that the proper
fix should be to change SMB2_OP_QUERY_WSL_EA code to not trigger that
-EOPNOTSUPP error which is delivered to userspace. I just checked that
this my patch works fine for Native NTFS symlinks and NFS-style reparse
point special files.
On Friday 13 September 2024 22:02:04 Pali Rohár wrote:
> If SMB server does not support WSL EAs then for SMB2_OP_QUERY_WSL_EA
> request it returns STATUS_EAS_NOT_SUPPORTED. Function smb2_compound_op()
> translates STATUS_EAS_NOT_SUPPORTED to -EOPNOTSUPP which cause failure
> during calling lstat() syscall from userspace on any reparse point,
> including Native SMB symlink (which does not use any EAs). This issue
> happen for example when trying to resolve Native NTFS symlink from SMB
> server on Windows 8.
>
> Avoid this problem by calling SMB2_OP_QUERY_WSL_EA only when detected
> reparse point is of WSL type. Note that this is not solve this problem
> fully as WSL reparse points can be created also on other SMB server
> which do not support Extended Attributes at all.
>
> Fixes: ea41367b2a60 ("smb: client: introduce SMB2_OP_QUERY_WSL_EA")
> Signed-off-by: Pali Rohár <pali@xxxxxxxxxx>
> ---
> fs/smb/client/smb2inode.c | 15 ++++++++++++++-
> 1 file changed, 14 insertions(+), 1 deletion(-)
>
> diff --git a/fs/smb/client/smb2inode.c b/fs/smb/client/smb2inode.c
> index 11a1c53c64e0..d65471aa55e6 100644
> --- a/fs/smb/client/smb2inode.c
> +++ b/fs/smb/client/smb2inode.c
> @@ -941,7 +941,20 @@ int smb2_query_path_info(const unsigned int xid,
> if (rc || !data->reparse_point)
> goto out;
>
> - cmds[num_cmds++] = SMB2_OP_QUERY_WSL_EA;
> + /*
> + * Skip SMB2_OP_QUERY_WSL_EA if reparse point is not WSL.
> + * The server file system does not have to support Extended
> + * Attributes and in this case returns STATUS_EAS_NOT_SUPPORTED
> + * which smb2_compound_op() translate to -EOPNOTSUPP. This will
> + * present failure during reading of non-WSL special files.
> + */
> + if (data->reparse.tag == IO_REPARSE_TAG_LX_SYMLINK ||
> + data->reparse.tag == IO_REPARSE_TAG_AF_UNIX ||
> + data->reparse.tag == IO_REPARSE_TAG_LX_FIFO ||
> + data->reparse.tag == IO_REPARSE_TAG_LX_CHR ||
> + data->reparse.tag == IO_REPARSE_TAG_LX_BLK)
> + cmds[num_cmds++] = SMB2_OP_QUERY_WSL_EA;
> +
> /*
> * Skip SMB2_OP_GET_REPARSE if symlink already parsed in create
> * response.
> --
> 2.20.1
>
