ovl: allow filenames with comma

Allow option separator (comma) to be escaped with backslash.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>

diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
index b92bd1829cf7efd73bade403872b94bac7970813..eee7a62e1c0e6ddf171ff08350a422d1d433d19f 100644 (file)
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -462,11 +462,34 @@ static const match_table_t ovl_tokens = {
        {OPT_ERR,                       NULL}
 };
 
+static char *ovl_next_opt(char **s)
+{
+       char *sbegin = *s;
+       char *p;
+
+       if (sbegin == NULL)
+               return NULL;
+
+       for (p = sbegin; *p; p++) {
+               if (*p == '\\') {
+                       p++;
+                       if (!*p)
+                               break;
+               } else if (*p == ',') {
+                       *p = '\0';
+                       *s = p + 1;
+                       return sbegin;
+               }
+       }
+       *s = NULL;
+       return sbegin;
+}
+
 static int ovl_parse_opt(char *opt, struct ovl_config *config)
 {
        char *p;
 
-       while ((p = strsep(&opt, ",")) != NULL) {
+       while ((p = ovl_next_opt(&opt)) != NULL) {
                int token;
                substring_t args[MAX_OPT_ARGS];
 
@@ -554,15 +577,34 @@ out_dput:
        goto out_unlock;
 }
 
+static void ovl_unescape(char *s)
+{
+       char *d = s;
+
+       for (;; s++, d++) {
+               if (*s == '\\')
+                       s++;
+               *d = *s;
+               if (!*s)
+                       break;
+       }
+}
+
 static int ovl_mount_dir(const char *name, struct path *path)
 {
        int err;
+       char *tmp = kstrdup(name, GFP_KERNEL);
+
+       if (!tmp)
+               return -ENOMEM;
 
-       err = kern_path(name, LOOKUP_FOLLOW, path);
+       ovl_unescape(tmp);
+       err = kern_path(tmp, LOOKUP_FOLLOW, path);
        if (err) {
-               pr_err("overlayfs: failed to resolve '%s': %i\n", name, err);
+               pr_err("overlayfs: failed to resolve '%s': %i\n", tmp, err);
                err = -EINVAL;
        }
+       kfree(tmp);
        return err;
 }