Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758704AbYB1McM (ORCPT ); Thu, 28 Feb 2008 07:32:12 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753679AbYB1McE (ORCPT ); Thu, 28 Feb 2008 07:32:04 -0500 Received: from mx1.suse.de ([195.135.220.2]:41335 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753630AbYB1McD (ORCPT ); Thu, 28 Feb 2008 07:32:03 -0500 Message-ID: <47C6A9C1.8000008@suse.de> Date: Thu, 28 Feb 2008 13:32:01 +0100 From: Frank Seidel User-Agent: Thunderbird 2.0.0.9 (X11/20071114) MIME-Version: 1.0 To: Alexander Viro Cc: linux-fsdevel@vger.kernel.org, LKML Subject: [RFC][PATCH] fs/partitions/msdos: directly check if FAT boot sector Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2610 Lines: 77 Hi, i received a complaint that some FAT formated medias (e.g. sd memory cards) trigger a "unknown partition table" message even though there is no partition table and they work correctly, while in general (when e.g. formated with mkdosfs or even Windows Vista) this message is not shown. Currently this seems only to happen when the medias get formatted with Windows XP (and possibly Win 2000). Then the boot indicator byte contains garbage (part of text message) and so do the other parts checked by msdos_paritition which then later triggers this message. Would the patch below be appropriate to solve this issue/calm those users? It works ok here for the medias i could test. Any feedback is very welcome. :-) Thanks, Frank --- From: Frank Seidel Subject: detect fat media without partition table correctly References: novell bug #364365 Most fat formatted media without partition table contains zeros in the boot indication and the other tested bytes and so falls through the checks in msdos_partition, leading it to return with 1 (all is fine). But some (e.g. WinXP formatted) fat fomated medias don't use boot_ind and so the check fails and causes a "unkown partition table" warning eventhough there is none and everything would be fine. This additional check directly verifies if there is a fat formatted medium without a partition table. Signed-off-by: Frank Seidel --- fs/partitions/msdos.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) --- a/fs/partitions/msdos.c +++ b/fs/partitions/msdos.c @@ -18,7 +18,7 @@ * * Re-organised Feb 1998 Russell King */ - +#include #include "check.h" #include "msdos.h" @@ -419,6 +419,7 @@ int msdos_partition(struct parsed_partit Sector sect; unsigned char *data; struct partition *p; + struct fat_boot_sector *fb; int slot; data = read_dev_sector(bdev, 0, §); @@ -441,6 +442,12 @@ int msdos_partition(struct parsed_partit * partition table. Reject this in case the boot indicator * is not 0 or 0x80. */ + fb = (struct fat_boot_sector *) data; + if (fb->reserved && fb->fats && FAT_VALID_MEDIA(fb->media)) { + printk("\n"); + put_dev_sector(sect); + return 1; + } p = (struct partition *) (data + 0x1be); for (slot = 1; slot <= 4; slot++, p++) { if (p->boot_ind != 0 && p->boot_ind != 0x80) { -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/