On 2015-10-09 at 16:55 +0200, Edward Shishkin wrote:

> 
> On 10/09/2015 03:50 PM, Ivan Shapovalov wrote:

> > On 2015-10-09 at 15:27 +0200, Edward Shishkin wrote:

> > > Hi Ivan,
> > > 
> > > On 10/09/2015 01:16 PM, Ivan Shapovalov wrote:

> > > > Ref.: https://www.mail-archive.com/linux-f2fs-devel%40lists.sou
> > > > rcef
> > > > orge.net/msg02745.html
> > > Do you have a stack trace for reiser4?
> > > How to reproduce it?
> > I'll rebuild the kernel without the fix and provide you with the
> > oops'
> > stacktrace asap.
> > 
> > I guess that it's tied to the config. In my case, it is
> > reproducible on
> > each boot, just as the DE starts up and something issues the first
> > fsync().
> 
> 
> Yes, let's try to find the culprit who doesn't set i_wb...

So, here is the oops:

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<1>[    8.653781] BUG: unable to handle kernel NULL pointer dereference at 00000000000000a8
<1>[    8.653808] IP: [<ffffffff8124ba3a>] __percpu_counter_add+0x1a/0x90
<4>[    8.653828] PGD 0
<4>[    8.653836] Oops: 0000 [#1] PREEMPT SMP
<4>[    8.653849] Modules linked in: fuse ctr ccm bnep joydev arc4 snd_hda_codec_realtek snd_hda_codec_generic snd_hda_codec_hdmi iwlmvm btusb btintel mac80211 bluetooth uvcvideo iTCO_wdt iTCO_vendor_support videobuf2_vmalloc videobuf2_memops videobuf2_core mousedev v4l2_common videodev x86_pkg_temp_thermal intel_powerclamp coretemp intel_rapl crc32_pclmul sha256_ssse3 crc16 sha256_generic hmac drbg snd_hda_intel iwlwifi snd_hda_codec aesni_intel aes_x86_64 ablk_helper snd_hwdep cfg80211 e1000e psmouse snd_hda_core cryptd lrw input_leds gf128mul glue_helper i2c_i801 snd_pcm thinkpad_acpi serio_raw pcspkr rtsx_pci_ms memstick mei_me lpc_ich mei snd_timer ptp snd pps_core thermal soundcore wmi nvram tpm_tis led_class rfkill tpm battery ac intel_smartconnect evdev processor sch_fq_codel tcp_yeah tcp_vegas vboxpci(O) vboxnetflt(O) vboxnetadp(O) vboxdrv(O) nfs fscache lockd grace sunrpc bbswitch(O) efivarfs ip_tables x_tables reiser4 sr_mod cdrom sd_mod hid_logitech_hidpp hid_logitech_dj usbhid hid rtsx_pci_sdmmc mmc_core i915 ahci libahci crc32c_intel i2c_algo_bit intel_gtt libata ehci_pci xhci_pci drm_kms_helper ehci_hcd xhci_hcd scsi_mod rtsx_pci mfd_core drm usbcore usb_common i2c_core video thermal_sys hwmon button
<4>[    8.654235] CPU: 1 PID: 141 Comm: kworker/u16:3 Tainted: G           O    4.2.0-pf2-intelfx-00190-gc800b69 #1
<4>[    8.654258] Hardware name: LENOVO 20BEA008RT/20BEA008RT, BIOS GMET70WW (2.18 ) 03/05/2015
<4>[    8.654279] Workqueue: writeback wb_workfn (flush-8:0)
<4>[    8.654294] task: ffff8800b736c380 ti: ffff88007f804000 task.ti: ffff88007f804000
<4>[    8.654311] RIP: 0010:[<ffffffff8124ba3a>]  [<ffffffff8124ba3a>] __percpu_counter_add+0x1a/0x90
<4>[    8.654333] RSP: 0018:ffff88007f807848  EFLAGS: 00010082
<4>[    8.654351] RAX: 0000000000000003 RBX: ffffea00089d91c0 RCX: 0000000000000001
<4>[    8.654368] RDX: 0000000000000020 RSI: 0000000000000001 RDI: 0000000000000088
<4>[    8.654384] RBP: ffff88007f807868 R08: 0000000000000000 R09: ffff88022aeb86b8
<4>[    8.654401] R10: 00000000fffffffa R11: 0000000000000000 R12: 0000000000000088
<4>[    8.654417] R13: 0000000000000001 R14: ffff88022cb04800 R15: ffff8800bad084a0
<4>[    8.654435] FS:  0000000000000000(0000) GS:ffff88023e240000(0000) knlGS:0000000000000000
<4>[    8.654454] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
<4>[    8.654467] CR2: 00000000000000a8 CR3: 000000000180b000 CR4: 00000000001406e0
<4>[    8.654484] Stack:
<4>[    8.654490]  ffff880234938000 ffffea00089d91c0 ffff8800bad08600 ffff8800bad08618
<4>[    8.654511]  ffff88007f8078c8 ffffffff810f3e59 ffff88007f807908 0000000000000292
<4>[    8.654532]  0000000000000000 ffff88007f908198 ffff8800b5ec23c0 ffff8800b5ec23c0
<4>[    8.654554] Call Trace:
<4>[    8.654563]  [<ffffffff810f3e59>] __test_set_page_writeback+0xd9/0x1c0
<4>[    8.654586]  [<ffffffffc03a5ad0>] write_jnodes_to_disk_extent+0x1b0/0x460 [reiser4]
<4>[    8.654606]  [<ffffffffc03a6003>] write_jnode_list+0x83/0xc0 [reiser4]
<4>[    8.654626]  [<ffffffffc03aabf8>] reiser4_write_fq+0x78/0x1c0 [reiser4]
<4>[    8.654644]  [<ffffffffc03a540a>] flush_current_atom+0x3ba/0x850 [reiser4]
<4>[    8.654663]  [<ffffffffc039f53a>] ? txnh_get_atom+0x2a/0x90 [reiser4]
<4>[    8.654682]  [<ffffffffc03a0e1c>] flush_some_atom+0x10c/0x4d0 [reiser4]
<4>[    8.654700]  [<ffffffffc03afc9e>] reiser4_writeout+0x14e/0x240 [reiser4]
<4>[    8.654719]  [<ffffffffc03abeec>] reiser4_writeback_inodes+0x9c/0x130 [reiser4]
<4>[    8.654738]  [<ffffffff81226c53>] ? fprop_fraction_percpu+0x33/0x90
<4>[    8.654754]  [<ffffffff8117a999>] writeback_sb_inodes+0x99/0xc0
<4>[    8.654769]  [<ffffffff8117aa47>] __writeback_inodes_wb+0x87/0xb0
<4>[    8.654784]  [<ffffffff8117ac1b>] wb_writeback+0x1ab/0x1d0
<4>[    8.654797]  [<ffffffff8117ad3a>] wb_workfn+0xfa/0x380
<4>[    8.654811]  [<ffffffff8106eaa8>] ? try_to_wake_up+0x268/0x420
<4>[    8.654827]  [<ffffffff81063366>] process_one_work+0x126/0x3c0
<4>[    8.654841]  [<ffffffff81063643>] worker_thread+0x43/0x4a0
<4>[    8.654855]  [<ffffffff81063600>] ? process_one_work+0x3c0/0x3c0
<4>[    8.654871]  [<ffffffff81068ea3>] kthread+0xd3/0xf0
<4>[    8.654884]  [<ffffffff81068dd0>] ? kthread_worker_fn+0x160/0x160
<4>[    8.654901]  [<ffffffff814641df>] ret_from_fork+0x3f/0x70
<4>[    8.654916]  [<ffffffff81068dd0>] ? kthread_worker_fn+0x160/0x160
<4>[    8.654930] Code: c3 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 55 48 89 e5 41 55 49 89 f5 41 54 49 89 fc 53 48 83 ec 08 65 ff 05 d6 ee db 7e <48> 8b 47 20 48 63 ca 65 8b 18 48 63 db 48 01 f3 48 39 cb 7d 0a
<1>[    8.655040] RIP  [<ffffffff8124ba3a>] __percpu_counter_add+0x1a/0x90
<4>[    8.655058]  RSP <ffff88007f807848>
<4>[    8.655067] CR2: 00000000000000a8
<4>[    8.655077] ---[ end trace 3db0fa7adb9580c7 ]---

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-- 
Ivan Shapovalov / intelfx /