Re: [PATCH] cifs: use standard token parser for mount options

[Scott Lovenberg <scott.lovenberg-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>]

On 3/21/2012 2:33 PM, Sachin Prabhu wrote:
> On Wed, 2012-03-21 at 13:38 -0400, Jeff Layton wrote:
>> On Fri, 09 Mar 2012 15:33:17 +0000
>> Sachin Prabhu<sprabhu-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>  wrote:
>>
>>> Use the standard token parser instead of the long if confidtion to parse
>>> cifs mount options.
>>>
>>> This was first proposed by Scott Lovenberg
>>> http://lists.samba.org/archive/linux-cifs-client/2010-May/006079.html
>>>
>>> Mount options have been grouped together in terms of their input types.
>>> Aliases for username, password, domain and credentials have been added.
>>> The password parser has been modified to make it easier to read.
>>>
>>> Signed-off-by: Sachin Prabhu<sprabhu-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
>>>
>>
>> In testing this today, I found a problem. I tried to mount up a share
>> with sec=none as the options. With that, I got this error:
>>
>>      CIFS: Unknown mount option pass=
>>
>> The problem is that the mount.cifs helper will pass a blank "pass="
>> option to the kernel. It seems like the standard option parser doesn't
>> have a way to allow you to specify an optional argument. That may need
>> to be added in order for this to work.
>
> We could use it in this manner.
>
> ----
> Allow mount option pass to be a blank value.
>
> When using sec=none, the mount.cifs helper will pass a blank 'pass='
> mount option. This should be handled by the parser.
>
> Signed-off-by: Sachin Prabhu<sprabhu-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
> ---
>   fs/cifs/connect.c |    7 +++++++
>   1 files changed, 7 insertions(+), 0 deletions(-)
>
> diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
> index 8f83ea0..831f242 100644
> --- a/fs/cifs/connect.c
> +++ b/fs/cifs/connect.c
> @@ -107,6 +107,9 @@ enum {
>   	/* Mount options to be ignored */
>   	Opt_ignore,
>
> +	/* Options which could be blank */
> +	Opt_blank_pass,
> +
>   	Opt_err
>   };
>
> @@ -180,6 +183,7 @@ static const match_table_t cifs_mount_option_tokens = {
>
>   	{ Opt_user, "user=%s" },
>   	{ Opt_user, "username=%s" },
> +	{ Opt_blank_pass, "pass=" },
>   	{ Opt_pass, "pass=%s" },
>   	{ Opt_pass, "password=%s" },
>   	{ Opt_ip, "ip=%s" },
> @@ -1546,6 +1550,9 @@ cifs_parse_mount_options(const char *mountdata, const char *devname,
>   			}
>   			vol->nullauth = 0;
>   			break;
> +		case Opt_blank_pass:
> +			vol->password = NULL;
> +			break;
>   		case Opt_pass:
>   			/* passwords have to be handled differently
>   			 * to allow the character used for deliminator
Are there any other options that are implicitly set?  Or, more 
generally, will this solution scale?