Bug 76451

Summary:	btrfs-cleaner related kernel oops following snapshot changes
Product:	File System	Reporter:	Ross Skaliotis (rskaliotis)
Component:	btrfs	Assignee:	Josef Bacik (josef)
Status:	RESOLVED OBSOLETE
Severity:	normal	CC:	dsterba, rskaliotis, szg00000
Priority:	P1
Hardware:	All
OS:	Linux
Kernel Version:	3.14.1	Subsystem:
Regression:	No	Bisected commit-id:

Description Ross Skaliotis 2014-05-18 18:45:34 UTC

I was fine after rebooting, but this did lock up my machine.

May 18 11:30:03 gonzo btrfs-snap: Create a readonly snapshot of '/home' in '/home/.snapshot/5m_2014-05-18_11:30:01'
May 18 11:30:03 gonzo btrfs-snap: Delete subvolume '/home/.snapshot/5m_2014-05-18_10:20:01'
May 18 11:30:12 gonzo kernel: BUG: unable to handle kernel NULL pointer dereference at 00000004
May 18 11:30:12 gonzo kernel: IP: [<c14698c0>] ulist_next+0x10/0x40
May 18 11:30:12 gonzo kernel: *pdpt = 0000000000000000 *pde = f000eef3f000eef3
May 18 11:30:12 gonzo kernel: Oops: 0000 [#1] SMP
May 18 11:30:12 gonzo kernel: Modules linked in: iwldvm led_class r8169 iwlwifi evdev
May 18 11:30:12 gonzo kernel: CPU: 3 PID: 4953 Comm: btrfs-cleaner Tainted: G        W    3.14.1 #1
May 18 11:30:12 gonzo kernel: Hardware name: Gigabyte Technology Co., Ltd. To be filled by O.E.M./H77N-WIFI, BIOS F4 07/31/2013
May 18 11:30:12 gonzo kernel: task: f2a09bc0 ti: ec674000 task.ti: ec674000
May 18 11:30:12 gonzo kernel: EIP: 0060:[<c14698c0>] EFLAGS: 00010296 CPU: 3
May 18 11:30:12 gonzo kernel: EIP is at ulist_next+0x10/0x40
May 18 11:30:12 gonzo kernel: EAX: 00000000 EBX: 00000004 ECX: 63921bf5 EDX: ec675dec
May 18 11:30:12 gonzo kernel: ESI: f0e54000 EDI: ec675e54 EBP: ec675dc0 ESP: ec675db8
May 18 11:30:12 gonzo kernel: DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068
May 18 11:30:12 gonzo kernel: CR0: 80050033 CR2: 00000004 CR3: 01fc7000 CR4: 001407f0
May 18 11:30:12 gonzo kernel: Stack:
May 18 11:30:12 gonzo kernel: 00000000 f0e54000 ec675dfc c14685aa 5ddc4000 00000a23 00000052 0000000d
May 18 11:30:12 gonzo kernel: ece3df60 ece3dc10 00000000 f0e54000 c8423680 cf73e590 f1739140 f0e54000
May 18 11:30:12 gonzo kernel: c8423680 ec675e64 c146c3a5 5ddc4000 00000a23 00000052 0000000d ec675e54
May 18 11:30:12 gonzo kernel: Call Trace:
May 18 11:30:12 gonzo kernel: [<c14685aa>] btrfs_find_all_roots+0x5a/0xf0
May 18 11:30:12 gonzo kernel: [<c146c3a5>] btrfs_qgroup_account_ref+0x175/0x670
May 18 11:30:12 gonzo kernel: [<c13efb31>] ? btrfs_delayed_refs_qgroup_accounting+0xa1/0x100
May 18 11:30:12 gonzo kernel: [<c13efb27>] btrfs_delayed_refs_qgroup_accounting+0x97/0x100
May 18 11:30:12 gonzo kernel: [<c10b847c>] ? srcu_reschedule+0x6c/0xa0
May 18 11:30:12 gonzo kernel: [<c10b881c>] ? srcu_advance_batches+0x9c/0xe0
May 18 11:30:12 gonzo kernel: [<c14083aa>] __btrfs_end_transaction+0x5a/0x310
May 18 11:30:12 gonzo kernel: [<c13ff457>] ? free_fs_root+0x87/0xb0
May 18 11:30:12 gonzo kernel: [<c13ff457>] ? free_fs_root+0x87/0xb0
May 18 11:30:12 gonzo kernel: [<c140866d>] btrfs_end_transaction_throttle+0xd/0x10
May 18 11:30:12 gonzo kernel: [<c13f6007>] btrfs_drop_snapshot+0x207/0x6c0
May 18 11:30:12 gonzo kernel: [<c145f9af>] ? btrfs_kill_all_delayed_nodes+0x3f/0xd0
May 18 11:30:12 gonzo kernel: [<c140e376>] ? btrfs_run_delayed_iputs+0xa6/0xc0
May 18 11:30:12 gonzo kernel: [<c1408fc0>] btrfs_clean_one_deleted_snapshot+0xc0/0x100
May 18 11:30:12 gonzo kernel: [<c140026e>] cleaner_kthread+0xee/0x120
May 18 11:30:12 gonzo kernel: [<c109341c>] kthread+0xac/0xd0
May 18 11:30:12 gonzo kernel: [<c1400180>] ? btrfs_alloc_root+0x30/0x30
May 18 11:30:12 gonzo kernel: [<c1b0c437>] ret_from_kernel_thread+0x1b/0x28
May 18 11:30:12 gonzo kernel: [<c1093370>] ? __kthread_parkme+0x60/0x60
May 18 11:30:12 gonzo kernel: Code: 89 1c 24 e8 73 fe ff ff 8b 5d f8 8b 75 fc c9 c3 8d 74 26 00 8d bc 27 00 00 00 00 55 89 e5 83 ec
08 89 1c 24 89 74 24 04 8d 58 04 <8b> 48 04 31 c0 39 cb 74 0b 8b 32 85 f6 75 11 89 0a 8d 41 f0 8b
May 18 11:30:12 gonzo kernel: EIP: [<c14698c0>] ulist_next+0x10/0x40 SS:ESP 0068:ec675db8
May 18 11:30:12 gonzo kernel: CR2: 0000000000000004
May 18 11:30:12 gonzo kernel: ---[ end trace 0c2db500342ed3a3 ]---

Comment 1 Ross Skaliotis 2014-05-18 19:19:52 UTC

Actually, I wasn't fine after rebooting. The filesystem mounts, but I'm hitting the same problem again after snapshot changes:

May 18 15:15:08 gonzo btrfs-snap: Create a readonly snapshot of '/home' in '/home/.snapshot/5m_2014-05-18_15:15:01'
May 18 15:15:08 gonzo btrfs-snap: Delete subvolume '/home/.snapshot/5m_2014-05-18_10:30:01'
May 18 15:15:09 gonzo btrfs-snap: Delete subvolume '/home/.snapshot/5m_2014-05-18_10:25:01'
May 18 15:15:09 gonzo btrfs-snap: Delete subvolume '/home/.snapshot/5m_2014-05-18_10:20:01'
May 18 15:15:42 gonzo kernel: BUG: unable to handle kernel NULL pointer dereference at 00000004
May 18 15:15:42 gonzo kernel: IP: [<c14698c0>] ulist_next+0x10/0x40
May 18 15:15:42 gonzo kernel: *pdpt = 0000000000000000 *pde = f000eef3f000eef3
May 18 15:15:42 gonzo kernel: Oops: 0000 [#1] SMP
May 18 15:15:42 gonzo kernel: Modules linked in: r8169 evdev
May 18 15:15:42 gonzo kernel: CPU: 0 PID: 5014 Comm: btrfs-cleaner Not tainted 3.14.1 #1
May 18 15:15:42 gonzo kernel: Hardware name: Gigabyte Technology Co., Ltd. To be filled by O.E.M./H77N-WIFI, BIOS F4 07/31/2013
May 18 15:15:42 gonzo kernel: task: f32bbc20 ti: ec21e000 task.ti: ec21e000
May 18 15:15:42 gonzo kernel: EIP: 0060:[<c14698c0>] EFLAGS: 00010296 CPU: 0
May 18 15:15:42 gonzo kernel: EIP is at ulist_next+0x10/0x40
May 18 15:15:42 gonzo kernel: EAX: 00000000 EBX: 00000004 ECX: 0000a7e2 EDX: ec21fdec
May 18 15:15:42 gonzo kernel: ESI: f244a000 EDI: ec21fe54 EBP: ec21fdc0 ESP: ec21fdb8
May 18 15:15:42 gonzo kernel: DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068
May 18 15:15:42 gonzo kernel: CR0: 80050033 CR2: 00000004 CR3: 01fc7000 CR4: 001407f0
May 18 15:15:42 gonzo kernel: Stack:
May 18 15:15:42 gonzo kernel: 00000000 f244a000 ec21fdfc c14685aa 5ddc4000 00000a23 00000035 00000005
May 18 15:15:42 gonzo kernel: f2459f70 f2459cc0 00000000 f244a000 f0e03820 ea3037d0 f0af7050 f244a000
May 18 15:15:42 gonzo kernel: f0e03820 ec21fe64 c146c3a5 5ddc4000 00000a23 00000035 00000005 ec21fe54
May 18 15:15:42 gonzo kernel: Call Trace:
May 18 15:15:42 gonzo kernel: [<c14685aa>] btrfs_find_all_roots+0x5a/0xf0
May 18 15:15:42 gonzo kernel: [<c146c3a5>] btrfs_qgroup_account_ref+0x175/0x670
May 18 15:15:42 gonzo kernel: [<c13efb31>] ? btrfs_delayed_refs_qgroup_accounting+0xa1/0x100
May 18 15:15:42 gonzo kernel: [<c13efb27>] btrfs_delayed_refs_qgroup_accounting+0x97/0x100
May 18 15:15:42 gonzo kernel: [<c14083aa>] __btrfs_end_transaction+0x5a/0x310
May 18 15:15:42 gonzo kernel: [<c140866d>] btrfs_end_transaction_throttle+0xd/0x10
May 18 15:15:42 gonzo kernel: [<c13f61a4>] btrfs_drop_snapshot+0x3a4/0x6c0
May 18 15:15:42 gonzo kernel: [<c145f9af>] ? btrfs_kill_all_delayed_nodes+0x3f/0xd0
May 18 15:15:42 gonzo kernel: [<c109e93b>] ? default_wake_function+0xb/0x10
May 18 15:15:42 gonzo kernel: [<c10aab18>] ? __wake_up_common+0x48/0x70
May 18 15:15:42 gonzo kernel: [<c1408fc0>] btrfs_clean_one_deleted_snapshot+0xc0/0x100
May 18 15:15:42 gonzo kernel: [<c140026e>] cleaner_kthread+0xee/0x120
May 18 15:15:42 gonzo kernel: [<c109341c>] kthread+0xac/0xd0
May 18 15:15:42 gonzo kernel: [<c1400180>] ? btrfs_alloc_root+0x30/0x30
May 18 15:15:42 gonzo kernel: [<c1b0c437>] ret_from_kernel_thread+0x1b/0x28
May 18 15:15:42 gonzo kernel: [<c1093370>] ? __kthread_parkme+0x60/0x60
May 18 15:15:42 gonzo kernel: Code: 89 1c 24 e8 73 fe ff ff 8b 5d f8 8b 75 fc c9 c3 8d 74 26 00 8d bc 27 00 00 00 00 55 89 e5 83 ec 08 89 1c 24 89 74 24 04 8d 58 04 <8b> 48 04 31 c0 39 cb 74 0b 8b 32 85 f6 75 11 89 0a 8d 41 f0 8b
May 18 15:15:42 gonzo kernel: EIP: [<c14698c0>] ulist_next+0x10/0x40 SS:ESP 0068:ec21fdb8
May 18 15:15:42 gonzo kernel: CR2: 0000000000000004
May 18 15:15:42 gonzo kernel: ---[ end trace 2d512ebabfb09138 ]---

Comment 2 David Sterba 2022-10-03 15:02:13 UTC

This is a semi-automated bugzilla cleanup, report is against an old kernel version. If the problem still happens, please open a new bug. Thanks.