fs/9p: Fix invalid mount options/args

commit a2dd43bb0d7b9ce28f8a39254c25840c0730498e upstream.

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.

Signed-off-by: Prem Karat <prem.karat@linux.vnet.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/fs/9p/v9fs.c b/fs/9p/v9fs.c
index 7d6c2139891db0d04673c6078d6a3f85c446dbb6..be525f6709d4f4ba4048d35e36b2d56f7240974c 100644 (file)
--- a/fs/9p/v9fs.c
+++ b/fs/9p/v9fs.c
@@ -75,6 +75,25 @@ 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
@@ -94,7 +113,7 @@ 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
@@ -168,13 +187,13 @@ 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;
 
@@ -195,9 +214,15 @@ 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;