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

[Prem Karat <prem.karat@linux.vnet.ibm.com>]

Hi JV,

Apologies for the delay in response & Thanks for reviewing it. 

On 05/08/11 10:51am, Venkateswararao Jujjuri wrote:
> 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?
No specific reason. Just wanted the code to be in consistent with net/9p/client.c (get_protocol_version()).
> 
> 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;
> >
> 

-- 
Cheers,
Prem
Linux Technology Center,
IBM Systems & Technology Labs
DID: 41776362