From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner+w=401wt.eu-S1752861AbZHCRsS@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
	id S1752861AbZHCRsS (ORCPT <rfc822;w@1wt.eu>);
	Mon, 3 Aug 2009 13:48:18 -0400
Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752665AbZHCRsR
	(ORCPT <rfc822;linux-kernel-outgoing>);
	Mon, 3 Aug 2009 13:48:17 -0400
Received: from rtr.ca ([76.10.145.34]:50993 "EHLO mail.rtr.ca"
	rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP
	id S1751971AbZHCRsQ (ORCPT <rfc822;linux-kernel@vger.kernel.org>);
	Mon, 3 Aug 2009 13:48:16 -0400
Message-ID: <4A7722DF.80704@rtr.ca>
Date: Mon, 03 Aug 2009 13:48:15 -0400
From: Mark Lord <lkml@rtr.ca>
Organization: Real-Time Remedies Inc.
User-Agent: Thunderbird 2.0.0.22 (X11/20090608)
MIME-Version: 1.0
To: Linux Kernel <linux-kernel@vger.kernel.org>, linux-ext4@vger.kernel.org
Cc: Eric Sandeen <sandeen@sandeen.net>,
       Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [PATCH] fs/compat_ioctl.c: add missing FS_IOC_FIEMAP support
References: <4A74584D.2010300@rtr.ca>
In-Reply-To: <4A74584D.2010300@rtr.ca>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

(resending, no ack from anyone first time around).

Add support for the FIEMAP ioctl for 32-bit user on 64-bit kernel.

When using a 32-bit runtime on top of a 64-bit kernel,
programs like "filefrag" and "hdparm --fibmap" do not work correctly.

This is because there's no compat ioctl entry for the FIEMAP call.
FIEMAP returns file extent info, similar to FIBMAP (but better).

Since FIBMAP itself is b0rked on ext4, this leaves no way for a 32-bit
program to reliably get detailed block information for a file
when run on top of a 64-bit kernel.  This patch addresses the issue.

Once upstream, this patch could also be a candidate for -stable.

Signed-off-by: Mark Lord <mlord@pobox.com>

Add support for the FIEMAP ioctl for 32-bit user on 64-bit kernel.

When using a 32-bit runtime on top of a 64-bit kernel,
programs like "filefrag" and "hdparm --fibmap" do not work correctly.

This is because there's no compat ioctl entry for the FIEMAP call.
FIEMAP returns file extent info, similar to FIBMAP (but better).

Since FIBMAP itself is b0rked on ext4, this leaves no way for a 32-bit
program to reliably get detailed block information for a file
when run on top of a 64-bit kernel.  This patch addresses the issue.

Once upstream, this patch could also be a candidate for -stable.

Signed-off-by: Mark Lord <mlord@pobox.com> 

--- old/fs/compat_ioctl.c	2009-08-01 10:47:16.601066905 -0400
+++ linux/fs/compat_ioctl.c	2009-08-01 10:49:23.054387926 -0400
@@ -35,6 +35,7 @@
 #include <linux/falloc.h>
 #include <linux/fs.h>
 #include <linux/file.h>
+#include <linux/fiemap.h>
 #include <linux/ppp_defs.h>
 #include <linux/if_ppp.h>
 #include <linux/if_pppox.h>
@@ -1907,6 +1908,7 @@
 COMPATIBLE_IOCTL(FIONREAD)  /* This is also TIOCINQ */
 /* 0x00 */
 COMPATIBLE_IOCTL(FIBMAP)
+COMPATIBLE_IOCTL(FS_IOC_FIEMAP)
 COMPATIBLE_IOCTL(FIGETBSZ)
 /* 'X' - originally XFS but some now in the VFS */
 COMPATIBLE_IOCTL(FIFREEZE)
@@ -2805,6 +2807,7 @@
 		goto out_fput;
 #endif
 
+	case FS_IOC_FIEMAP:
 	case FIBMAP:
 	case FIGETBSZ:
 	case FIONREAD: