On Thu, 12 Apr 2007 00:14:59 +0200 Michal Piotrowski <[EMAIL PROTECTED]> wrote:
> Andrew Morton napisa__(a): > > On Wed, 11 Apr 2007 20:03:17 +0200 > > Michal Piotrowski <[EMAIL PROTECTED]> wrote: > > > >> [EMAIL PROTECTED] napisa__(a): > >>> The mm snapshot broken-out-2007-04-11-02-24.tar.gz has been uploaded to > >>> > >>> > >>> ftp://ftp.kernel.org/pub/linux/kernel/people/akpm/mm/broken-out-2007-04-11-02-24.tar.gz > >>> > >>> It contains the following patches against 2.6.21-rc6: > >>> > >> After a few seconds of running test_mount_fs.sh > >> http://www.stardust.webpages.pl/files/tbf/bitis-gabonica/broken-out-2007-04-11-02-24/test_mount_fs.sh > >> I get this > >> > >> [11083.747512] Filesystem "loop4": Disabling barriers, not supported by > >> the underlying device > >> [11083.759050] XFS mounting filesystem loop4 > >> [11083.763769] Slab corruption: xfs_buf start=cce14938, len=272 > >> [11083.769986] Redzone: 0x5a2cf071/0x5a2cf071. > >> [11083.774575] Last user: [<fddaacde>](xfs_buf_free+0x77/0x7b [xfs]) > >> [11083.781146] 0b0: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6c 6b 6b 6b > >> [11083.787988] Prev obj: start=cce1481c, len=272 > >> [11083.792488] Redzone: 0x5a2cf071/0x5a2cf071. > >> [11083.796828] Last user: [<fddaacde>](xfs_buf_free+0x77/0x7b [xfs]) > >> [11083.803131] 000: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b > >> [11083.810392] 010: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b > >> [11083.817677] Next obj: start=cce14a54, len=272 > >> [11083.822146] Redzone: 0x5a2cf071/0x5a2cf071. > >> [11083.826415] Last user: [<fddaacde>](xfs_buf_free+0x77/0x7b [xfs]) > >> [11083.832784] 000: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b > >> [11083.839403] 010: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b > >> [11083.852797] Ending clean XFS mount for filesystem: loop4 > >> [11083.865789] SELinux: initialized (dev loop4, type xfs), uses xattr > >> > > > > It does appear that someone (probably XFS) has done a use-after-free. > > > > One way in which you perhaps catch this is to do: > > > > --- a/fs/xfs/linux-2.6/xfs_buf.h~a > > +++ a/fs/xfs/linux-2.6/xfs_buf.h > > @@ -151,6 +151,7 @@ typedef struct xfs_buf { > > #ifdef XFS_BUF_LOCK_TRACKING > > int b_last_holder; > > #endif > > + char crap[1024]; > > } xfs_buf_t; > > > > > > and to then compile with CONFIG_DEBUG_PAGEALLOC. The enlarged xfs_buf will > > then get unmap-when-freed treatment and hopefully you'll get a nice oops > > from the instruction which is corrupting that memory. > > [ 1053.655367] BUG: unable to handle kernel paging request at virtual address > d6871b50 > [ 1053.663214] printing eip: > [ 1053.665971] fdd91dfe > [ 1053.668207] *pde = 0005b067 > [ 1053.671088] *pte = 16871000 > [ 1053.673948] Oops: 0000 [#1] > [ 1053.676795] PREEMPT SMP DEBUG_PAGEALLOC > [ 1053.680793] last sysfs file: devices/platform/w83627hf.656/temp2_input > [ 1053.687460] Modules linked in: jfs nls_base xfs reiserfs ext4dev jbd2 ext2 > loop ipt_MASQUERADE iptable_nat nf_nat nfsd exportfs lockd nfs_acl autofs4 > sunrpc af_packet nf_conntrack_netbios_ns ipt_REJECT nf_conntrack_ipv4 > xt_state nf_conntrack nfnetlink iptable_filter ip_tables ip6t_REJECT > xt_tcpudp ip6table_filter ip6_tables x_tables ipv6 binfmt_misc thermal > processor fan container nvram snd_intel8x0 snd_ac97_codec ac97_bus > snd_seq_dummy snd_seq_oss snd_seq_midi_event evdev snd_seq snd_seq_device > snd_pcm_oss snd_mixer_oss snd_pcm snd_timer snd soundcore snd_page_alloc > intel_agp i2c_i801 agpgart ide_cd cdrom rtc unix > [ 1053.744461] CPU: 1 > [ 1053.744462] EIP: 0060:[<fdd91dfe>] Not tainted VLI > [ 1053.744465] EFLAGS: 00010292 (2.6.21-rc6-mm1-1 #2) > [ 1053.757285] EIP is at xlog_iodone+0x99/0xbb [xfs] > [ 1053.762069] eax: 00000000 ebx: d6871ae8 ecx: c04a396c edx: 00000000 > [ 1053.769002] esi: d6871ae8 edi: d0f7def8 ebp: d0fa5f30 esp: d0fa5f18 > [ 1053.775912] ds: 007b es: 007b fs: 00d8 gs: 0000 ss: 0068 > [ 1053.781842] Process xfslogd/1 (pid: 3642, ti=d0fa4000 task=cac7f5a0 > task.ti=d0fa4000) > [ 1053.789660] Stack: c01339fc d0f36130 db641df8 d6871ae8 d0f3611c d6871b84 > d0fa5f40 fddab492 > [ 1053.798450] dd2439ad d6871b88 d0fa5f70 c0133a26 c9c39db0 d0f36144 > d0fa5f70 c01372d8 > [ 1053.807213] 00000000 00000000 fddab477 d0f3611c d0f85d70 00000000 > d0fa5fb0 c0134469 > [ 1053.815902] Call Trace: > [ 1053.818721] [<fddab492>] xfs_buf_iodone_work+0x1b/0x3e [xfs] > [ 1053.824830] [<c0133a26>] run_workqueue+0x8e/0x15a > [ 1053.829766] [<c0134469>] worker_thread+0x108/0x116 > [ 1053.834793] [<c013707c>] kthread+0xb5/0xe1 > [ 1053.839129] [<c0104eb3>] kernel_thread_helper+0x7/0x10 > [ 1053.844539] ======================= > [ 1053.848172] INFO: lockdep is turned off. > [ 1053.852201] Code: 46 4c db fd ba 02 00 00 00 e8 61 fc 01 00 ba 02 00 00 00 > eb 0f 8a 47 78 83 e0 80 3c 01 19 d2 f7 d2 83 e2 02 89 f8 e8 99 f7 ff ff <f6> > 46 68 10 75 14 f0 ff 86 bc 00 00 00 7f 0b 8d 86 bc 00 00 00 > [ 1053.872927] EIP: [<fdd91dfe>] xlog_iodone+0x99/0xbb [xfs] SS:ESP > 0068:d0fa5f18 > Bingo. So it seems the xfslogd_workqueue is being run after unmount has freed the memory which it uses. Or something along those lines. > > > >> http://www.stardust.webpages.pl/files/tbf/bitis-gabonica/broken-out-2007-04-11-02-24/serialconsole.log > >> http://www.stardust.webpages.pl/files/tbf/bitis-gabonica/broken-out-2007-04-11-02-24/mm-config > >> > >> BTW. I wonder when this bug will be fixed > >> [11050.534896] ============================================= > >> [11050.541883] [ INFO: possible recursive locking detected ] > >> [11050.547425] 2.6.21-rc6-mm1-1 #1 > >> [11050.550630] --------------------------------------------- > >> [11050.556142] umount/3359 is trying to acquire lock: > >> [11050.561060] (&(&ip->i_lock)->mr_lock){----}, at: [<fdd8729a>] > >> xfs_ilock+0x4d/0x6e [xfs] > >> [11050.569565] > >> [11050.569567] but task is already holding lock: > >> [11050.575487] (&(&ip->i_lock)->mr_lock){----}, at: [<fdd8729a>] > >> xfs_ilock+0x4d/0x6e [xfs] > > > > An xfs thing. > > Yes, I know. This is a known bug since at least 05-Jul-2006. > It's probably not very important - often these things turn out to not really be deadlockable at all. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
