Re: [V9fs-developer] [PATCH] fs/9p: Fix invalid mount options/args

[Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>]

On 05/06/2011 05:54 AM, Prem Karat wrote:
> fs/9p: Fix invalid mount options/args
>
> Without this fix, if any invalid mount options/args are passed while mouting the 9p fs,
> no error (-EINVAL) is returned and default arg value is assigned.
>
> This fix returns -EINVAL when an invalid arguement is found while parsing mount options.
Prem, Thanks for the patch.
Quick question..any reason why you have a new function for cache, and 
in-line here?

Thanks,
JV
> Signed-off-by: Prem Karat<prem.karat@linux.vnet.ibm.com>
> ---
>   fs/9p/v9fs.c |   43 ++++++++++++++++++++++++++++++++++---------
>   1 files changed, 34 insertions(+), 9 deletions(-)
>
> diff --git a/fs/9p/v9fs.c b/fs/9p/v9fs.c
> index c82b017..033c23e 100644
> --- a/fs/9p/v9fs.c
> +++ b/fs/9p/v9fs.c
> @@ -78,6 +78,25 @@ static const match_table_t tokens = {
>   	{Opt_err, NULL}
>   };
>
> +/* Interpret mount options for cache mode */
> +static int get_cache_mode(char *s)
> +{
> +	int version = -EINVAL;
> +
> +	if (!strcmp(s, "loose")) {
> +		version = CACHE_LOOSE;
> +		P9_DPRINTK(P9_DEBUG_9P, "Cache mode: loose\n");
> +	} else if (!strcmp(s, "fscache")) {
> +		version = CACHE_FSCACHE;
> +		P9_DPRINTK(P9_DEBUG_9P, "Cache mode: fscache\n");
> +	} else if (!strcmp(s, "none")) {
> +		version = CACHE_NONE;
> +		P9_DPRINTK(P9_DEBUG_9P, "Cache mode: none\n");
> +	} else
> +		printk(KERN_INFO "9p: Unknown Cache mode %s.\n", s);
> +	return version;
> +}
> +
>   /**
>    * v9fs_parse_options - parse mount options into session structure
>    * @v9ses: existing v9fs session information
> @@ -97,7 +116,7 @@ static int v9fs_parse_options(struct v9fs_session_info *v9ses, char *opts)
>   	/* setup defaults */
>   	v9ses->afid = ~0;
>   	v9ses->debug = 0;
> -	v9ses->cache = 0;
> +	v9ses->cache = CACHE_NONE;
>   #ifdef CONFIG_9P_FSCACHE
>   	v9ses->cachetag = NULL;
>   #endif
> @@ -171,13 +190,13 @@ static int v9fs_parse_options(struct v9fs_session_info *v9ses, char *opts)
>   				  "problem allocating copy of cache arg\n");
>   				goto free_and_return;
>   			}
> +			ret = get_cache_mode(s);
> +			if (ret == -EINVAL) {
> +				kfree(s);
> +				goto free_and_return;
> +			}
>
> -			if (strcmp(s, "loose") == 0)
> -				v9ses->cache = CACHE_LOOSE;
> -			else if (strcmp(s, "fscache") == 0)
> -				v9ses->cache = CACHE_FSCACHE;
> -			else
> -				v9ses->cache = CACHE_NONE;
> +			v9ses->cache = ret;
>   			kfree(s);
>   			break;
>
> @@ -200,9 +219,15 @@ static int v9fs_parse_options(struct v9fs_session_info *v9ses, char *opts)
>   			} else {
>   				v9ses->flags |= V9FS_ACCESS_SINGLE;
>   				v9ses->uid = simple_strtoul(s,&e, 10);
> -				if (*e != '\0')
> -					v9ses->uid = ~0;
> +				if (*e != '\0') {
> +					ret = -EINVAL;
> +					printk(KERN_INFO "9p: Unknown access "
> +							"argument %s.\n", s);
> +					kfree(s);
> +					goto free_and_return;


> +				}
>   			}
> +
>   			kfree(s);
>   			break;
>