tomoyo: struct path it might get from LSM callers won't have NULL dentry or mnt

Acked-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

security/tomoyo/file.c

@@ -717,7 +717,7 @@ int tomoyo_path_number_perm(const u8 type, const struct path *path,
 	int idx;
 
 	if (tomoyo_init_request_info(&r, NULL, tomoyo_pn2mac[type])
-	    == TOMOYO_CONFIG_DISABLED || !path->dentry)
+	    == TOMOYO_CONFIG_DISABLED)
 		return 0;
 	idx = tomoyo_read_lock();
 	if (!tomoyo_get_realpath(&buf, path))

security/tomoyo/realpath.c

@@ -240,11 +240,8 @@ char *tomoyo_realpath_from_path(const struct path *path)
 	char *name = NULL;
 	unsigned int buf_len = PAGE_SIZE / 2;
 	struct dentry *dentry = path->dentry;
-	struct super_block *sb;
+	struct super_block *sb = dentry->d_sb;
 
-	if (!dentry)
-		return NULL;
-	sb = dentry->d_sb;
 	while (1) {
 		char *pos;
 		struct inode *inode;
@@ -264,10 +261,8 @@ char *tomoyo_realpath_from_path(const struct path *path)
 		inode = d_backing_inode(sb->s_root);
 		/*
 		 * Get local name for filesystems without rename() operation
-		 * or dentry without vfsmount.
 		 */
-		if (!path->mnt ||
-		    (!inode->i_op->rename &&
+		if ((!inode->i_op->rename &&
 		     !(sb->s_type->fs_flags & FS_REQUIRES_DEV)))
 			pos = tomoyo_get_local_path(path->dentry, buf,
 						    buf_len - 1);