[PATCH] v9fs: replace strlen on newly allocated by __getname buffers to PATH_MAX

v9fs_vfs_readlink allocates space for the link using __getname and
errorneously uses strlen on the newly allocated buffer to check if the buffer
passed by the user is bigger than the one returned by __getname.

The patch replaces the strlen usage to PATH_MAX, which is the actual size of
the buffers returned by __getname.
Signed-off-by: NLatchesar Ionkov <lucho@ionkov.net>
Cc: Eric Van Hensbergen <ericvh@gmail.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

fs/9p/vfs_inode.c

@@ -1063,8 +1063,8 @@ static int v9fs_vfs_readlink(struct dentry *dentry, char __user * buffer,
 	int ret;
 	char *link = __getname();
 
-	if (strlen(link) < buflen)
-		buflen = strlen(link);
+	if (buflen > PATH_MAX)
+		buflen = PATH_MAX;
 
 	dprintk(DEBUG_VFS, " dentry: %s (%p)\n", dentry->d_iname, dentry);