Bug 12433

Summary:	Oops while resizing an ext4 LVM2 volume
Product:	File System	Reporter:	Peter Kerwien (peter)
Component:	ext4	Assignee:	fs_ext4 (fs_ext4)
Status:	CLOSED CODE_FIX
Severity:	normal	CC:	dries.kimpe
Priority:	P1
Hardware:	All
OS:	Linux
Kernel Version:	2.6.29-rc1	Subsystem:
Regression:	---	Bisected commit-id:

Description Peter Kerwien 2009-01-11 12:20:11 UTC

Latest working kernel version: N/A
Earliest failing kernel version: 2.6.29-rc1
Distribution: Gentoo Linux amd64
Hardware Environment: 
Software Environment: e2fsprogs-1.41.3
Problem Description: During a resize of an ext4 formated lvm2 volume, a NULL pointer was derefrenced.

When I executed this command on a mounted LVM2 volume:

# resize2fs /dev/vg1/ftp

The following error happened:

Jan 11 20:56:41 kerwien kernel: BUG: unable to handle kernel NULL pointer dereference at (null)
Jan 11 20:56:41 kerwien kernel: IP: [<ffffffffa01c6b59>] ext4_block_bitmap+0x9/0x30 [ext4]
Jan 11 20:56:41 kerwien kernel: PGD 1a873067 PUD 3eded067 PMD 0 
Jan 11 20:56:41 kerwien kernel: Oops: 0000 [#1] SMP 
Jan 11 20:56:41 kerwien kernel: last sysfs file: /sys/devices/virtual/block/dm-0/range
Jan 11 20:56:41 kerwien kernel: CPU 0 
Jan 11 20:56:41 kerwien kernel: Modules linked in: ide_cd_mod cdrom dm_mod zlib_deflate zlib_inflate cryptomgr aead crypto_blkcipher crc32c libcrc32c crypto_hash crypto_algapi nfs lockd sunrpc cpufreq_ondemand snd_seq snd_seq_device ext4 jbd2 crc16 powernow_k8 freq_table usbhid snd_intel8x0 snd_ac97_codec ac97_bus snd_pcm ehci_hcd ohci_hcd snd_timer floppy snd sg usbcore forcedeth soundcore k8temp snd_page_alloc hwmon thermal processor button ext3 jbd mbcache sata_nv libata sd_mod amd74xx [last unloaded: cdrom]
Jan 11 20:56:41 kerwien kernel: Pid: 5202, comm: resize2fs Not tainted 2.6.29-rc1 #3
Jan 11 20:56:41 kerwien kernel: RIP: 0010:[<ffffffffa01c6b59>]  [<ffffffffa01c6b59>] ext4_block_bitmap+0x9/0x30 [ext4]
Jan 11 20:56:41 kerwien kernel: RSP: 0018:ffff88001a9cdbc0  EFLAGS: 00010246
Jan 11 20:56:41 kerwien kernel: RAX: ffff88003ec90000 RBX: 0000000000000200 RCX: 00000000c0000100
Jan 11 20:56:41 kerwien kernel: RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8800333dfc00
Jan 11 20:56:41 kerwien kernel: RBP: ffff8800333dfc00 R08: ffff88001a9cc000 R09: 0000000000000000
Jan 11 20:56:41 kerwien kernel: R10: ffff880001011ff0 R11: 0000000000000001 R12: 0000000000000202
Jan 11 20:56:41 kerwien kernel: R13: ffff88003ec90000 R14: 0000000000000000 R15: ffff88003ec90000
Jan 11 20:56:41 kerwien kernel: FS:  00007fa469b62710(0000) GS:ffffffff80593040(0000) knlGS:00000000f7caeaf0
Jan 11 20:56:41 kerwien kernel: CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
Jan 11 20:56:41 kerwien kernel: CR2: 0000000000000000 CR3: 000000003eaa6000 CR4: 00000000000006e0
Jan 11 20:56:41 kerwien kernel: DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
Jan 11 20:56:41 kerwien kernel: DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Jan 11 20:56:41 kerwien kernel: Process resize2fs (pid: 5202, threadinfo ffff88001a9cc000, task ffff88003ef5e310)
Jan 11 20:56:41 kerwien kernel: Stack:
Jan 11 20:56:41 kerwien kernel:  ffffffffa01b8877 0000000000000003 0000000000000246 0000800000000191
Jan 11 20:56:41 kerwien kernel:  ffff88003f7b0a20 0000000000000000 ffff88000a5c23d8 0000000000000000
Jan 11 20:56:41 kerwien kernel:  ffff88003ed400c0 ffff88003e40e888 ffff8800333dfc00 0000000000000191
Jan 11 20:56:41 kerwien kernel: Call Trace:
Jan 11 20:56:41 kerwien kernel:  [<ffffffffa01b8877>] ? ext4_init_block_bitmap+0x347/0x3d0 [ext4]
Jan 11 20:56:41 kerwien kernel:  [<ffffffffa01d5955>] ? ext4_mb_add_groupinfo+0x105/0x1f0 [ext4]
Jan 11 20:56:41 kerwien kernel:  [<ffffffffa01cdbf1>] ? ext4_group_add+0xa01/0x1330 [ext4]
Jan 11 20:56:41 kerwien kernel:  [<ffffffff802b3c80>] ? sync_buffer+0x0/0x50
Jan 11 20:56:41 kerwien kernel:  [<ffffffff80430290>] ? io_schedule+0x20/0x30
Jan 11 20:56:41 kerwien kernel:  [<ffffffff8024fa70>] ? wake_bit_function+0x0/0x30
Jan 11 20:56:41 kerwien kernel:  [<ffffffffa01c26bf>] ? ext4_ioctl+0x55f/0x6d0 [ext4]
Jan 11 20:56:41 kerwien kernel:  [<ffffffff8035af48>] ? do_output_char+0x208/0x210
Jan 11 20:56:41 kerwien kernel:  [<ffffffff8024fc39>] ? remove_wait_queue+0x19/0x60
Jan 11 20:56:41 kerwien kernel:  [<ffffffff80230903>] ? __wake_up+0x43/0x70
Jan 11 20:56:41 kerwien kernel:  [<ffffffff8029f74f>] ? vfs_ioctl+0x2f/0xa0
Jan 11 20:56:41 kerwien kernel:  [<ffffffff8029f9db>] ? do_vfs_ioctl+0x21b/0x530
Jan 11 20:56:41 kerwien kernel:  [<ffffffff8042fc9f>] ? thread_return+0x41/0x592
Jan 11 20:56:41 kerwien kernel:  [<ffffffff8029fd39>] ? sys_ioctl+0x49/0x80
Jan 11 20:56:41 kerwien kernel:  [<ffffffff8020c335>] ? device_not_available+0x15/0x20
Jan 11 20:56:41 kerwien kernel:  [<ffffffff8020b61b>] ? system_call_fastpath+0x16/0x1b
Jan 11 20:56:41 kerwien kernel: Code: 66 90 48 89 c7 45 31 ed e8 15 bd 0e e0 e9 e1 fa ff ff 0f 0b eb fe 90 90 90 90 90 90 90 90 90 90 90 90 48 8b 87 88 02 00 00 31 d2 <8b> 0e 48 83 38 3f 76 07 8b 56 20 48 c1 e2 20 89 c8 48 09 c2 48 
Jan 11 20:56:41 kerwien kernel: RIP  [<ffffffffa01c6b59>] ext4_block_bitmap+0x9/0x30 [ext4]
Jan 11 20:56:41 kerwien kernel:  RSP <ffff88001a9cdbc0>
Jan 11 20:56:41 kerwien kernel: CR2: 0000000000000000
Jan 11 20:56:41 kerwien kernel: ---[ end trace 19e39679f9447577 ]---
Jan 11 20:56:41 kerwien kernel: ------------[ cut here ]------------
Jan 11 20:56:41 kerwien kernel: WARNING: at kernel/exit.c:1010 do_exit+0x72b/0x850()
Jan 11 20:56:41 kerwien kernel: Hardware name:  
Jan 11 20:56:41 kerwien kernel: Modules linked in: ide_cd_mod cdrom dm_mod zlib_deflate zlib_inflate cryptomgr aead crypto_blkcipher crc32c libcrc32c crypto_hash crypto_algapi nfs lockd sunrpc cpufreq_ondemand snd_seq snd_seq_device ext4 jbd2 crc16 powernow_k8 freq_table usbhid snd_intel8x0 snd_ac97_codec ac97_bus snd_pcm ehci_hcd ohci_hcd snd_timer floppy snd sg usbcore forcedeth soundcore k8temp snd_page_alloc hwmon thermal processor button ext3 jbd mbcache sata_nv libata sd_mod amd74xx [last unloaded: cdrom]
Jan 11 20:56:41 kerwien kernel: Pid: 5202, comm: resize2fs Tainted: G      D    2.6.29-rc1 #3
Jan 11 20:56:41 kerwien kernel: Call Trace:
Jan 11 20:56:41 kerwien kernel:  [<ffffffff8023afc2>] warn_slowpath+0xf2/0x130
Jan 11 20:56:41 kerwien kernel:  [<ffffffff80367f65>] notify_update+0x25/0x30
Jan 11 20:56:41 kerwien kernel:  [<ffffffff80368213>] vt_console_print+0x223/0x2f0
Jan 11 20:56:41 kerwien kernel:  [<ffffffff8020bf4e>] common_interrupt+0xe/0x13
Jan 11 20:56:41 kerwien kernel:  [<ffffffff8023bca7>] vprintk+0x227/0x390
Jan 11 20:56:41 kerwien kernel:  [<ffffffff8023be5e>] printk+0x4e/0x60
Jan 11 20:56:41 kerwien kernel:  [<ffffffff8023be5e>] printk+0x4e/0x60
Jan 11 20:56:41 kerwien kernel:  [<ffffffff8023e73b>] do_exit+0x72b/0x850
Jan 11 20:56:41 kerwien kernel:  [<ffffffff80253886>] up+0x16/0x50
Jan 11 20:56:41 kerwien kernel:  [<ffffffff8032ccb0>] bit_cursor+0x0/0x5e0
Jan 11 20:56:41 kerwien kernel:  [<ffffffff8023b7e5>] release_console_sem+0x1b5/0x1f0
Jan 11 20:56:41 kerwien kernel:  [<ffffffff8020f5a5>] oops_end+0xa5/0xb0
Jan 11 20:56:41 kerwien kernel:  [<ffffffff80228b53>] do_page_fault+0x323/0x890
Jan 11 20:56:41 kerwien kernel:  [<ffffffffa01c7fe6>] ext4_error+0x96/0xc0 [ext4]
Jan 11 20:56:41 kerwien kernel:  [<ffffffff80431cef>] page_fault+0x1f/0x30
Jan 11 20:56:41 kerwien kernel:  [<ffffffffa01c6b59>] ext4_block_bitmap+0x9/0x30 [ext4]
Jan 11 20:56:41 kerwien kernel:  [<ffffffffa01b8877>] ext4_init_block_bitmap+0x347/0x3d0 [ext4]
Jan 11 20:56:41 kerwien kernel:  [<ffffffffa01d5955>] ext4_mb_add_groupinfo+0x105/0x1f0 [ext4]
Jan 11 20:56:41 kerwien kernel:  [<ffffffffa01cdbf1>] ext4_group_add+0xa01/0x1330 [ext4]
Jan 11 20:56:41 kerwien kernel:  [<ffffffff802b3c80>] sync_buffer+0x0/0x50
Jan 11 20:56:41 kerwien kernel:  [<ffffffff80430290>] io_schedule+0x20/0x30
Jan 11 20:56:41 kerwien kernel:  [<ffffffff8024fa70>] wake_bit_function+0x0/0x30
Jan 11 20:56:41 kerwien kernel:  [<ffffffffa01c26bf>] ext4_ioctl+0x55f/0x6d0 [ext4]
Jan 11 20:56:41 kerwien kernel:  [<ffffffff8035af48>] do_output_char+0x208/0x210
Jan 11 20:56:41 kerwien kernel:  [<ffffffff8024fc39>] remove_wait_queue+0x19/0x60
Jan 11 20:56:41 kerwien kernel:  [<ffffffff80230903>] __wake_up+0x43/0x70
Jan 11 20:56:41 kerwien kernel:  [<ffffffff8029f74f>] vfs_ioctl+0x2f/0xa0
Jan 11 20:56:41 kerwien kernel:  [<ffffffff8029f9db>] do_vfs_ioctl+0x21b/0x530
Jan 11 20:56:41 kerwien kernel:  [<ffffffff8042fc9f>] thread_return+0x41/0x592
Jan 11 20:56:41 kerwien kernel:  [<ffffffff8029fd39>] sys_ioctl+0x49/0x80
Jan 11 20:56:41 kerwien kernel:  [<ffffffff8020c335>] device_not_available+0x15/0x20
Jan 11 20:56:41 kerwien kernel:  [<ffffffff8020b61b>] system_call_fastpath+0x16/0x1b
Jan 11 20:56:41 kerwien kernel: ---[ end trace 19e39679f9447578 ]---
Jan 11 20:57:27 kerwien kernel: ------------[ cut here ]------------
Jan 11 20:57:27 kerwien kernel: WARNING: at fs/namespace.c:636 mntput_no_expire+0x146/0x150()
Jan 11 20:57:27 kerwien kernel: Hardware name:  
Jan 11 20:57:27 kerwien kernel: Modules linked in: ide_cd_mod cdrom dm_mod zlib_deflate zlib_inflate cryptomgr aead crypto_blkcipher crc32c libcrc32c crypto_hash crypto_algapi nfs lockd sunrpc cpufreq_ondemand snd_seq snd_seq_device ext4 jbd2 crc16 powernow_k8 freq_table usbhid snd_intel8x0 snd_ac97_codec ac97_bus snd_pcm ehci_hcd ohci_hcd snd_timer floppy snd sg usbcore forcedeth soundcore k8temp snd_page_alloc hwmon thermal processor button ext3 jbd mbcache sata_nv libata sd_mod amd74xx [last unloaded: cdrom]
Jan 11 20:57:27 kerwien kernel: Pid: 5230, comm: umount Tainted: G      D W  2.6.29-rc1 #3
Jan 11 20:57:27 kerwien kernel: Call Trace:
Jan 11 20:57:27 kerwien kernel:  [<ffffffff8023afc2>] warn_slowpath+0xf2/0x130
Jan 11 20:57:27 kerwien kernel:  [<ffffffff802a8c75>] mntput_no_expire+0x35/0x150
Jan 11 20:57:27 kerwien kernel:  [<ffffffff8029cf29>] __link_path_walk+0xbe9/0xd50
Jan 11 20:57:27 kerwien kernel:  [<ffffffff802305cc>] update_curr+0x6c/0xc0
Jan 11 20:57:27 kerwien kernel:  [<ffffffff802305cc>] update_curr+0x6c/0xc0
Jan 11 20:57:27 kerwien kernel:  [<ffffffff8023055a>] wakeup_preempt_entity+0x3a/0x40
Jan 11 20:57:27 kerwien kernel:  [<ffffffff80237413>] check_preempt_wakeup+0x113/0x150
Jan 11 20:57:27 kerwien kernel:  [<ffffffff80233dae>] try_to_wake_up+0x10e/0x1b0
Jan 11 20:57:27 kerwien kernel:  [<ffffffff802a1bd5>] pollwake+0x55/0x60
Jan 11 20:57:27 kerwien kernel:  [<ffffffff80233e50>] default_wake_function+0x0/0x10
Jan 11 20:57:27 kerwien kernel:  [<ffffffff8022fdcb>] __wake_up_common+0x5b/0x90
Jan 11 20:57:27 kerwien kernel:  [<ffffffff802a8d86>] mntput_no_expire+0x146/0x150
Jan 11 20:57:27 kerwien kernel:  [<ffffffff802a9066>] sys_umount+0x76/0x380
Jan 11 20:57:27 kerwien kernel:  [<ffffffff8020b61b>] system_call_fastpath+0x16/0x1b
Jan 11 20:57:27 kerwien kernel: ---[ end trace 19e39679f9447579 ]---

Steps to reproduce: Unknown. I have resized ext4 volumes a couple of time. This error has only happened once so far.

Comment 1 Thadeu Lima de Souza Cascardo 2009-01-23 13:02:44 UTC

Have you enabled flex_bg recently? Have you kept the log? Any message indicating an error like this one?

Jan 23 14:20:42 vespa kernel: [  463.027499] EXT4-fs error (device dm-11): ext4_get_group_desc: block_group >= groups_count - block_group = 11, groups_count = 11

I've hit this bug and fixed it. The patch was sent to linux-ext4 and is available at http://holoscopio.com/patches/0001-ext4-fix-oops-when-online-resizing-a-filesystem-wit.patch. Could you, please, test it?

Regards,
Cascardo.

Comment 2 Peter Kerwien 2009-01-23 14:00:37 UTC

flex_bg is default on when creating ext4 on my Gentoo system.

Yeap, I found this in my log:
...
Jan 11 20:54:58 kerwien kernel: EXT4-fs: mounted filesystem dm-0 with ordered data mode
Jan 11 20:56:41 kerwien kernel: EXT4-fs error (device dm-0): ext4_get_group_desc: block_group >= groups_count -
 block_group = 401, groups_count = 401
Jan 11 20:56:41 kerwien kernel: BUG: unable to handle kernel NULL pointer dereference at (null)
Jan 11 20:56:41 kerwien kernel: IP: [<ffffffffa01c6b59>] ext4_block_bitmap+0x9/0x30 [ext4]
Jan 11 20:56:41 kerwien kernel: PGD 1a873067 PUD 3eded067 PMD 0 
...

I can try the patch and see if I can reproduce the problem again or not.

Comment 3 Peter Kerwien 2009-02-03 10:49:14 UTC

I applied the patch to 2.6.29-rc1 and have resized an ext4 volume, both as logical with lvm2 and a normal disk partition. I have experimented with both online and offline resize to a larger size and offline resize to a smaller size. I have done this approx. 15-20 times and so far no more oops.

Comment 4 Theodore Tso 2009-02-03 11:18:51 UTC

This patch has been merged into the Linux mainline and should be in 2.6.29-rc4 (and newer) releases.