kernel-packages team mailing list archive

[Stefan Bader <stefan.bader@xxxxxxxxxxxxx>]

Possibly fixed indirectly by this because that at least checks for
outstanding io to be done in try_write...

commit cb7a583e6a6ace661a5890803e115d2292a293df
Author: Kent Overstreet <kmo@xxxxxxxxxxxxx>
Date:   Mon Dec 16 15:27:25 2013 -0800

    bcache: kill closure locking usage
    
    Signed-off-by: Kent Overstreet <kmo@xxxxxxxxxxxxx>

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https://bugs.launchpad.net/bugs/1445273

Title:
  trusty amd64 kernel with bcache module panics on unregister

Status in linux package in Ubuntu:
  Incomplete

Bug description:
  We have a system with 3 block devices (SATA) split into  2 partitions
  each, and create RAID0 md0 (sda1, sdb1, sdc1), and RAID0 md1 (sda2,
  sdb2, sdc2).  We then create a bcache device on an SSD and set it to
  writeback mode, (/dev/bcache0).

  When we attempt to release/unregister the bcache device, it panics.
  Here's the release script and panic.

  #!/bin/bash -x

  sudo su - -c "echo 1 >/sys/fs/bcache/*-*-*-*-*/unregister"
  sudo su - -c "echo 1 >/sys/block/bcache0/bcache/stop"
  sudo mdadm --stop /dev/md0
  sudo mdadm --stop /dev/md1
  for dev in sda sdb sdc; do
          sudo mdadm --zero-superblock /dev/${dev}1
          sudo mdadm --zero-superblock /dev/${dev}2
          END="$(sudo blockdev --getsz /dev/${dev})"
          GPT_END=$(($END - 100))
          sudo dd if=/dev/zero of=/dev/${dev} bs=1M count=1
          sudo dd if=/dev/zero of=/dev/${dev} bs=512 seek=${GPT_END}
          sync
          sudo blockdev --rereadpt /dev/${dev}
  done
  sudo wipefs -a /dev/sdd
  cat /proc/partitions


  [  318.047616] BUG: unable to handle kernel NULL pointer dereference at 0000000000000a00
  [  318.055478] IP: [<ffffffffa0278280>] journal_write_unlocked+0x130/0x540 [bcache]
  [  318.062889] PGD 0 
  [  318.064917] Oops: 0000 [#1] SMP 
  [  318.068177] Modules linked in: btrfs raid6_pq xor ufs qnx4 hfsplus hfs minix ntfs msdos jfs xfs libcrc32c bcache raid0 raid1 ib_iser rdma_cm iw_cm ib_cm ib_sa ib_mad ib_core 
  ib_addr dm_crypt gpio_ich intel_powerclamp coretemp kvm_intel kvm joydev ioatdma i7core_edac shpchp serio_raw edac_core lpc_ich mac_hid dca overlayfs iscsi_tcp libiscsi_tcp libi
  scsi scsi_transport_iscsi hid_generic e1000e usbhid ptp ahci psmouse pata_acpi hid libahci pps_core                                                                              
  [  318.108586] CPU: 9 PID: 17196 Comm: kworker/9:2 Not tainted 3.13.0-49-generic #81-Ubuntu
  [  318.116669] Hardware name: Supermicro X8DTT-H/X8DTT-H, BIOS 2.1b       10/28/2011
  [  318.124147] Workqueue: events journal_write_work [bcache]
  [  318.129558] task: ffff880c1a6cc800 ti: ffff880c1b9c2000 task.ti: ffff880c1b9c2000
  [  318.137027] RIP: 0010:[<ffffffffa0278280>]  [<ffffffffa0278280>] journal_write_unlocked+0x130/0x540 [bcache]
  [  318.146866] RSP: 0018:ffff880c1b9c3d90  EFLAGS: 00010202
  [  318.152170] RAX: 0000000000000000 RBX: 0000000000000001 RCX: 0000000000000000
  [  318.159295] RDX: ffff880604560c48 RSI: ffff88060456cad8 RDI: ffff880606c70040
  [  318.166419] RBP: ffff880c1b9c3de8 R08: 2018115b2f400000 R09: 5e80000000000000
  [  318.173542] R10: dfe776aad516cbd0 R11: 0000000000003d06 R12: 0000000000000001
  [  318.180669] R13: ffff88060456cba0 R14: ffff88060456ccc8 R15: ffff880604560000
  [  318.187801] FS:  0000000000000000(0000) GS:ffff880c3fc60000(0000) knlGS:0000000000000000
  [  318.195879] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
  [  318.201616] CR2: 0000000000000a00 CR3: 0000000001c0e000 CR4: 00000000000007e0
  [  318.208741] Stack:
  [  318.210751]  ffff88062780ac00 ffff880604560000 0000000000000000 0000000000000240
  [  318.218205]  ffff880c1b9c3dc0 ffffffff81076108 ffff880604560000 ffff88060456cba0
  [  318.225657]  ffff88060456cbd0 0000000000000000 0000000000000240 ffff880c1b9c3e08
  [  318.233112] Call Trace:
  [  318.235564]  [<ffffffff81076108>] ? add_timer+0x18/0x20
  [  318.240790]  [<ffffffffa02786e0>] journal_try_write+0x50/0x60 [bcache]
  [  318.247316]  [<ffffffffa0278712>] journal_write_work+0x22/0x30 [bcache]
  [  318.253926]  [<ffffffff81083a82>] process_one_work+0x182/0x450
  [  318.259757]  [<ffffffff81084871>] worker_thread+0x121/0x410
  [  318.265331]  [<ffffffff81084750>] ? rescuer_thread+0x430/0x430
  [  318.271166]  [<ffffffff8108b5b2>] kthread+0xd2/0xf0
  [  318.276045]  [<ffffffff8108b4e0>] ? kthread_create_on_node+0x1c0/0x1c0
  [  318.282571]  [<ffffffff8173258c>] ret_from_fork+0x7c/0xb0
  [  318.287969]  [<ffffffff8108b4e0>] ? kthread_create_on_node+0x1c0/0x1c0
  [  318.294494] Code: 00 00 e8 64 9f 0f e1 31 c0 66 41 83 bd 94 38 ff ff 00 49 8b 8d a0 40 ff ff 49 8d 97 48 0c 00 00 74 3c 66 0f 1f 84 00 00 00 00 00 <48> 8b b9 00 0a 00 00 0f b7 89 ce 00 00 00 83 c0 01 49 8b 36 48 
  [  318.314445] RIP  [<ffffffffa0278280>] journal_write_unlocked+0x130/0x540 [bcache]
  [  318.321943]  RSP <ffff880c1b9c3d90>
  [  318.325426] CR2: 0000000000000a00
  [  318.328740] ---[ end trace 66f8467ce2b49a92 ]---
  [  318.333407] BUG: unable to handle kernel paging request at ffffffffffffffd8
  [  318.340394] IP: [<ffffffff8108bc50>] kthread_data+0x10/0x20
  [  318.345985] PGD 1c11067 PUD 1c13067 PMD 0 
  [  318.350129] Oops: 0000 [#2] SMP 
  [  318.353388] Modules linked in: btrfs raid6_pq xor ufs qnx4 hfsplus hfs minix ntfs msdos jfs xfs libcrc32c bcache raid0 raid1 ib_iser rdma_cm iw_cm ib_cm ib_sa ib_mad ib_core ib_addr dm_crypt gpio_ich intel_powerclamp coretemp kvm_intel kvm joydev ioatdma i7core_edac shpchp serio_raw edac_core lpc_ich mac_hid dca overlayfs iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi hid_generic e1000e usbhid ptp ahci psmouse pata_acpi hid libahci pps_core                                                                              
  [  318.393796] CPU: 9 PID: 17196 Comm: kworker/9:2 Tainted: G      D       3.13.0-49-generic #81-Ubuntu
  [  318.402920] Hardware name: Supermicro X8DTT-H/X8DTT-H, BIOS 2.1b       10/28/2011
  [  318.410401] task: ffff880c1a6cc800 ti: ffff880c1b9c2000 task.ti: ffff880c1b9c2000
  [  318.417873] RIP: 0010:[<ffffffff8108bc50>]  [<ffffffff8108bc50>] kthread_data+0x10/0x20
  [  318.425880] RSP: 0018:ffff880c1b9c39e8  EFLAGS: 00010002
  [  318.431184] RAX: 0000000000000000 RBX: 0000000000000009 RCX: 000000000000000f
  [  318.438309] RDX: 0000000000000000 RSI: 0000000000000009 RDI: ffff880c1a6cc800
  [  318.445433] RBP: ffff880c1b9c39e8 R08: 0000000000000000 R09: ffff880c3fc77bc0
  [  318.452558] R10: ffffffff8133ff6a R11: ffffea00306b0ec0 R12: ffff880c3fc734c0
  [  318.459683] R13: 0000000000000009 R14: ffff880c1a6cc7f0 R15: ffff880c1a6cc800
  [  318.466808] FS:  0000000000000000(0000) GS:ffff880c3fc60000(0000) knlGS:0000000000000000
  [  318.474893] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
  [  318.480632] CR2: 0000000000000028 CR3: 0000000001c0e000 CR4: 00000000000007e0
  [  318.487764] Stack:
  [  318.489775]  ffff880c1b9c3a00 ffffffff81084f81 ffff880c1a6cc800 ffff880c1b9c3a60
  [  318.497229]  ffffffff81725cd9 ffff880c1a6cc800 ffff880c1b9c3fd8 00000000000134c0
  [  318.504683]  00000000000134c0 ffff880c1a6cc800 ffff880c1a6cce50 ffff880c1a6cc7f0
  [  318.512137] Call Trace:
  [  318.514583]  [<ffffffff81084f81>] wq_worker_sleeping+0x11/0x90
  [  318.520420]  [<ffffffff81725cd9>] __schedule+0x589/0x7d0
  [  318.525728]  [<ffffffff81725f49>] schedule+0x29/0x70
  [  318.530697]  [<ffffffff8106a16f>] do_exit+0x6df/0xa50
  [  318.535750]  [<ffffffff8172b0a9>] oops_end+0xa9/0x150
  [  318.540801]  [<ffffffff8171a75d>] no_context+0x27e/0x28b
  [  318.546114]  [<ffffffff8171a7dd>] __bad_area_nosemaphore+0x73/0x1ca
  [  318.552379]  [<ffffffff8171a947>] bad_area_nosemaphore+0x13/0x15
  [  318.558389]  [<ffffffff8172da97>] __do_page_fault+0xa7/0x570
  [  318.564047]  [<ffffffff8172df7a>] do_page_fault+0x1a/0x70
  [  318.569446]  [<ffffffff810744e7>] ? internal_add_timer+0x17/0x40
  [  318.575453]  [<ffffffff8172a3a8>] page_fault+0x28/0x30
  [  318.580599]  [<ffffffffa0278280>] ? journal_write_unlocked+0x130/0x540 [bcache]
  [  318.587899]  [<ffffffff81076108>] ? add_timer+0x18/0x20
  [  318.593129]  [<ffffffffa02786e0>] journal_try_write+0x50/0x60 [bcache]
  [  318.599655]  [<ffffffffa0278712>] journal_write_work+0x22/0x30 [bcache]
  [  318.606265]  [<ffffffff81083a82>] process_one_work+0x182/0x450
  [  318.612098]  [<ffffffff81084871>] worker_thread+0x121/0x410
  [  318.617671]  [<ffffffff81084750>] ? rescuer_thread+0x430/0x430
  [  318.623504]  [<ffffffff8108b5b2>] kthread+0xd2/0xf0
  [  318.628383]  [<ffffffff8108b4e0>] ? kthread_create_on_node+0x1c0/0x1c0
  [  318.634910]  [<ffffffff8173258c>] ret_from_fork+0x7c/0xb0
  [  318.640309]  [<ffffffff8108b4e0>] ? kthread_create_on_node+0x1c0/0x1c0
  [  318.646832] Code: 00 48 89 e5 5d 48 8b 40 c8 48 c1 e8 02 83 e0 01 c3 66 2e 0f 1f 84 00 00 00 00 00 66 66 66 66 90 48 8b 87 c0 03 00 00 55 48 89 e5 <48> 8b 40 d8 5d c3 66 2e 0f 1f 84 00 00 00 00 00 66 66 66 66 90                                                                                                                                            
  [  318.666786] RIP  [<ffffffff8108bc50>] kthread_data+0x10/0x20
  [  318.672461]  RSP <ffff880c1b9c39e8>
  [  318.675946] CR2: ffffffffffffffd8
  [  318.679259] ---[ end trace 66f8467ce2b49a93 ]---
  [  318.683877] Fixing recursive fault but reboot is needed!

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