From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030676Ab2GLPQx (ORCPT ); Thu, 12 Jul 2012 11:16:53 -0400 Received: from mail.digidescorp.com ([50.73.98.161]:8646 "EHLO mail.digidescorp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932679Ab2GLPQv (ORCPT ); Thu, 12 Jul 2012 11:16:51 -0400 DomainKey-Signature: a=rsa-sha1; s=MDaemon; d=digidescorp.com; c=simple; q=dns; h=message-id:from; b=QQJM8bs0fRG46uduya7kwLqO3FHMKT83RujOmrz74X5aGcWpbj5d0BYrvg2m TlGxMo28pqudW2QnPjlRxB+usu7voLAFHYw+ve74W5DtpK8mBAtAV5h5p LmiuHYOUynK6XV4fi3Zt1C1zdBNAdu5OVgR+J45fB3KBBzlgFE5Q8I=; X-Spam-Processed: mail.digidescorp.com, Thu, 12 Jul 2012 10:16:49 -0500 (not processed: message from trusted or authenticated source) X-Authenticated-Sender: steve@digidescorp.com X-Return-Path: prvs=15403394f6=steve@digidescorp.com X-Envelope-From: steve@digidescorp.com X-MDaemon-Deliver-To: linux-kernel@vger.kernel.org Message-ID: <1342106206.2156.2.camel@iscandar.digidescorp.com> Subject: Re: mount -o loop with truncated dosdisk.img uses 100% cpu and can't be killed From: "Steven J. Magnani" To: Stevie Trujillo Cc: OGAWA Hirofumi , linux-kernel@vger.kernel.org Date: Thu, 12 Jul 2012 10:16:46 -0500 In-Reply-To: <20120712162828.3f561315@localhost> References: <20120712162828.3f561315@localhost> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.4.3 (3.4.3-1.fc17) Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 2012-07-12 at 16:28 +0200, Stevie Trujillo wrote: > Hello, > > I was trying to create a bootdisk to update my BIOS, and accidentially > made a 512byte image with only the FreeDOS header in it. > > ( Linux 3.4.4 ) > # mount -o loop dosdisk.img /tmp > ^C^C^C > It uses 100% CPU and doesn't listen to me when I do ^C, kill -9 etc. I > think this means it's stuck in the kernel? Here is the stack trace I get for the mount process: [root@telezart smagnani]# cat /proc/1334/stack [] __cond_resched+0x2a/0x40 [] find_lock_page+0x3b/0x80 [] find_or_create_page+0x3f/0xb0 [] __getblk+0xf2/0x2a0 [] __bread+0x13/0xb0 [] fat__get_entry+0x14e/0x220 [fat] [] fat_get_short_entry+0x66/0xc0 [fat] [] fat_subdirs+0x55/0x80 [fat] [] fat_fill_super+0x810/0xa80 [fat] [] vfat_fill_super+0x1a/0x20 [vfat] [] mount_bdev+0x1cb/0x210 [] vfat_mount+0x15/0x20 [vfat] [] mount_fs+0x20/0xd0 [] vfs_kern_mount+0x6f/0x100 [] do_kern_mount+0x54/0x110 [] do_mount+0x306/0x8b0 [] sys_mount+0x8d/0xe0 [] system_call_fastpath+0x16/0x1b [] 0xffffffffffffffff I would think this is more likely a bug in the loopback driver than the FAT filesystem... ------------------------------------------------------------------------ Steven J. Magnani "I claim this network for MARS! www.digidescorp.com Earthling, return my space modulator!" #include