From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759411AbXHAQOU (ORCPT ); Wed, 1 Aug 2007 12:14:20 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754086AbXHAQOK (ORCPT ); Wed, 1 Aug 2007 12:14:10 -0400 Received: from hc6521514.dhcp.vt.edu ([198.82.21.20]:49762 "EHLO hc6521514.dhcp.vt.edu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752250AbXHAQOI (ORCPT ); Wed, 1 Aug 2007 12:14:08 -0400 X-Greylist: delayed 2793 seconds by postgrey-1.27 at vger.kernel.org; Wed, 01 Aug 2007 12:14:08 EDT X-Mailer: exmh version 2.7.2 01/07/2005 with nmh-1.2 To: Andrew Morton Cc: linux-kernel@vger.kernel.org Subject: Re: 2.6.23-rc1-mm1 - loopback mount of files fails loop-use-unlocked_ioctl.patch In-Reply-To: Your message of "Wed, 25 Jul 2007 04:03:04 PDT." <20070725040304.111550f4.akpm@linux-foundation.org> From: Valdis.Kletnieks@vt.edu References: <20070725040304.111550f4.akpm@linux-foundation.org> Mime-Version: 1.0 Content-Type: multipart/signed; boundary="==_Exmh_1185981898_4258P"; micalg=pgp-sha1; protocol="application/pgp-signature" Content-Transfer-Encoding: 7bit Date: Wed, 01 Aug 2007 11:24:58 -0400 Message-ID: <31610.1185981898@turing-police.cc.vt.edu> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org --==_Exmh_1185981898_4258P Content-Type: text/plain; charset=us-ascii On Wed, 25 Jul 2007 04:03:04 PDT, Andrew Morton said: > ftp://ftp.kernel.org/pub/linux/kernel/people/akpm/patches/2.6/2.6.23-rc1/2.6.23-rc1-mm1/ Looks like -rc1-mm2 came out while I was hunting this, haven't tried that yet) File-backed loopback seems to be broken (note that I use a LVM volume with a 'mount -o loop,encryption=aes /dev/mapper/...' every day - that *does* work). loop-use-unlocked_ioctl.patch is the offender after bisecting. I had created an ISO image with genisoimage, and to test it, I had done: mount -o loop.ro /path/to/temp.iso /mnt (Note that the image itself is good - I burned it to a CD, and then 'mount /dev/cdrom /mnt' worked just fine, so it's definitely the loopback, and on file-backed mounts...). and got treated to this wonderful oops: [ 170.420603] Unable to handle kernel NULL pointer dereference at 00000000000000b8 RIP: [ 170.420877] [] lo_ioctl+0x21/0x94a [ 170.421243] PGD 41c5067 PUD 6111067 PMD 0 [ 170.421464] Oops: 0000 [1] PREEMPT SMP [ 170.421671] CPU 0 [ 170.421775] Modules linked in: sha256 aes video output thermal processor fan container button bay battery ac nvram pcmcia firmware_class ohci1394 yenta_socket ieee1394 rsrc_nonstatic iTCO_wdt pcmcia_core iTCO_vendor_support intel_agp rtc [ 170.422989] Pid: 1616, comm: mount Not tainted 2.6.23-rc1 #3 [ 170.423254] RIP: 0010:[] [] lo_ioctl+0x21/0x94a [ 170.423627] RSP: 0018:ffff8100047076d8 EFLAGS: 00010296 [ 170.423876] RAX: ffffffff80698720 RBX: 00000000fffffdfd RCX: ffffffff803bf990 [ 170.424210] RDX: ffff810004707b18 RSI: 0000000000005310 RDI: 0000000000000000 [ 170.424544] RBP: ffff8100047078d8 R08: ffff810004707b18 R09: ffff810004707968 [ 170.424878] R10: ffff810004707b18 R11: ffff810004707b18 R12: 0000000000005310 [ 170.425212] R13: ffff810004707b18 R14: ffff810004707b18 R15: 0000000000000000 [ 170.425547] FS: 00002b82792a4740(0000) GS:ffffffff806e1000(0000) knlGS:0000000000000000 [ 170.425928] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b [ 170.426197] CR2: 00000000000000b8 CR3: 000000000610b000 CR4: 00000000000006e0 [ 170.426531] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 170.439502] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 [ 170.452460] Process mount (pid: 1616, threadinfo ffff810004706000, task ffff810006898800) [ 170.465758] Stack: 0000003900000044 ffff810006898800 0000000000000000 ffff810006812588 [ 170.479365] 0000000005071980 0000000000000007 0000000000000000 0000000000000044 [ 170.493151] 0000000000100000 ffff8100047077b8 ffff8100047077a8 ffffffff8031facb [ 170.493517] Call Trace: [ 170.520574] [] avc_has_perm+0x4c/0x5e [ 170.534308] [] inode_has_perm+0x6b/0x7a [ 170.547974] [] __d_lookup+0xe1/0x154 [ 170.561721] [] kobject_get+0x1a/0x21 [ 170.575187] [] get_disk+0x8d/0xad [ 170.588601] [] exact_lock+0xc/0x14 [ 170.601969] [] kobj_lookup+0x14d/0x183 [ 170.615253] [] blkdev_driver_ioctl+0x39/0x78 [ 170.628545] [] blkdev_ioctl+0x65b/0x6b7 [ 170.641836] [] __blkdev_get+0x7b/0x8d [ 170.655105] [] ioctl_by_bdev+0x34/0x48 [ 170.668432] [] isofs_fill_super+0x337/0xa68 [ 170.681666] [] __down_write_nested+0x3d/0xab [ 170.694896] [] __down_write+0xb/0xd [ 170.707835] [] sget+0x374/0x386 [ 170.720528] [] set_bdev_super+0x0/0x14 [ 170.733267] [] get_sb_bdev+0x109/0x157 [ 170.745881] [] isofs_fill_super+0x0/0xa68 [ 170.758382] [] isofs_get_sb+0x13/0x15 [ 170.770713] [] vfs_kern_mount+0x90/0x11a [ 170.782999] [] do_kern_mount+0x47/0xe2 [ 170.795245] [] do_mount+0x691/0x704 [ 170.807349] [] mntput_no_expire+0x1e/0x98 [ 170.819351] [] link_path_walk+0xe8/0xfc [ 170.831216] [] bdput+0xd/0xf [ 170.843065] [] mntput_no_expire+0x1e/0x98 [ 170.854874] [] path_walk+0x1c/0x1e [ 170.866566] [] do_path_lookup+0x1b6/0x22f [ 170.878247] [] putname+0x37/0x39 [ 170.889781] [] __user_walk_fd+0x4c/0x5c [ 170.901309] [] __alloc_pages+0x5c/0x2b5 [ 170.912789] [] mntput_no_expire+0x1e/0x98 [ 170.924359] [] sys_mount+0x89/0xcb [ 170.935859] [] sys_rt_sigprocmask+0x58/0xd7 [ 170.947361] [] system_call+0x7e/0x83 [ 170.958877] [ 170.970241] [ 170.970241] Code: 48 8b 87 b8 00 00 00 48 8b 18 48 8b 83 e8 01 00 00 48 8b 80 [ 170.993080] RIP [] lo_ioctl+0x21/0x94a [ 171.004333] RSP [ 171.015387] CR2: 00000000000000b8 [ 171.029069] mount used greatest stack depth: 3304 bytes left --==_Exmh_1185981898_4258P Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.7 (GNU/Linux) Comment: Exmh version 2.5 07/13/2001 iD8DBQFGsKXKcC3lWbTT17ARAmCmAKCYZbOZf8NuJ2wD+3D6ATkOubV+JgCeMrWO T16QpQ7JnAD3ovgR2KxYDbw= =6oxw -----END PGP SIGNATURE----- --==_Exmh_1185981898_4258P--