zap_create_claim fails

[ari]

I have a pool which throws errors on boot, plus it cannot be exported (the command just hangs). I also cannot destroy this pool. Suggestions for workaround to destroy this pool are welcome.

# uname -a
Linux tv 3.17.7-gentoo #1 SMP Sun Jan 4 10:12:47 AEDT 2015 x86_64 Intel(R) Core(TM) i5-2400 CPU @ 3.10GHz GenuineIntel GNU/Linux

ZFS: 0.6.3-r2

I'm new to ZFS on Linux, but have 5-6 years experience of ZFS on FreeBSD. The following was in dmesg. I cannot see any logs from when I try "zpool export storage" but the process is in state "D". 

[   17.079506] BUG: unable to handle kernel NULL pointer dereference at 0000000000000018
[   17.080187] IP: [<ffffffffc08a8c7b>] zap_create_claim+0x9e/0x274 [zfs]
[   17.080899] PGD 0
[   17.080901] Oops: 0000 [#1] SMP
[   17.080929] Modules linked in: dm_mod zfs(PO) zunicode(PO) zavl(PO) zcommon(PO) znvpair(PO) spl(O) zlib_deflate usbkbd usbhid zl10353 xc4000 tuner cx25840 cx23885 tveeprom btcx_risc altera_ci videobuf_dvb dvb_core tda18271 i915 i2c_algo_bit cx2341x video altera_stapl drm_kms_helper x86_pkg_temp_thermal snd_hda_codec_hdmi coretemp videobuf_dma_sg videobuf_core microcode drm acpi_cpufreq e1000e v4l2_common videodev ir_lirc_codec backlight pcspkr snd_hda_codec_realtek snd_hda_codec_generic lirc_dev intel_gtt snd_hda_intel processor media ir_xmp_decoder ir_sanyo_decoder ir_mce_kbd_decoder ir_sony_decoder ir_sharp_decoder ir_nec_decoder ir_rc5_decoder ir_rc6_decoder ir_jvc_decoder firmware_class i2c_i801 i2c_core snd_hda_controller button snd_hda_codec ptp rc_rc6_mce pps_core ehci_pci ehci_hcd usbcore
[   17.080931]  nuvoton_cir rc_core usb_common thermal_sys snd_hwdep snd_pcm snd_timer snd
[   17.080933] CPU: 3 PID: 1460 Comm: txg_sync Tainted: P           O   3.17.7-gentoo #1
[   17.080934] Hardware name:                  /DH67BL, BIOS BLH6710H.86A.0128.2011.0823.1224 08/23/2011
[   17.080935] task: ffff88001fc8c7b0 ti: ffff8800cf41c000 task.ti: ffff8800cf41c000
[   17.080941] RIP: 0010:[<ffffffffc08a8c7b>]  [<ffffffffc08a8c7b>] zap_create_claim+0x9e/0x274 [zfs]
[   17.080942] RSP: 0018:ffff8800cf41fba8  EFLAGS: 00010292
[   17.080943] RAX: 000000000000001c RBX: ffff88011a601800 RCX: 000000000000001e
[   17.080943] RDX: 000000000000001d RSI: 000000000000001c RDI: ffff88011a601800
[   17.080944] RBP: ffff8800cf41fc18 R08: 0000000000000000 R09: ffff8800cf41fbe0
[   17.080944] R10: 0000000000000000 R11: ffff88011a605bc0 R12: 0000000000000002
[   17.080945] R13: ffff880119dc6c40 R14: 0000000000000000 R15: 000000000000001d
[   17.080946] FS:  0000000000000000(0000) GS:ffff88011fb80000(0000) knlGS:0000000000000000
[   17.080946] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   17.080947] CR2: 0000000000000018 CR3: 000000001851d000 CR4: 00000000000407e0
[   17.080947] Stack:
[   17.080949]  000000000000000a ffff8800cbdfc050 0000000000000001 ffff880119dc6c40
[   17.080949]  ffff8800cf41fbd8 ffffffff983a817c ffff8800cf41fbf8 ffffffffc08544a9
[   17.080950]  ffff8800cbdfc050 ffff88011a85a000 0000000000000000 ffff880119dc6c40
[   17.080951] Call Trace:
[   17.080955]  [<ffffffff983a817c>] ? mutex_unlock+0x9/0xb
[   17.080960]  [<ffffffffc08544a9>] ? dbuf_rele_and_unlock+0x1c9/0x511 [zfs]
[   17.080966]  [<ffffffffc08a920c>] spa_feature_decr+0x44/0xa8 [zfs]
[   17.080971]  [<ffffffffc0857b9a>] ? bptree_is_empty+0x82/0x8b [zfs]
[   17.080980]  [<ffffffffc087ba28>] dsl_scan_sync+0x258/0x8cb [zfs]
[   17.080982]  [<ffffffffc04a39a2>] ? spl_kmem_cache_free+0x4a/0x137 [spl]
[   17.080987]  [<ffffffffc08d1faa>] ? zio_wait+0x16f/0x17e [zfs]
[   17.080996]  [<ffffffffc0889e6b>] spa_sync+0x596/0x951 [zfs]
[   17.080998]  [<ffffffff9805a1a8>] ? __wake_up_common+0x49/0x80
[   17.081000]  [<ffffffff9806d260>] ? ktime_get_ts64+0x53/0xc3
[   17.081009]  [<ffffffffc08974aa>] txg_init+0x43d/0x92f [zfs]
[   17.081016]  [<ffffffffc089724d>] ? txg_init+0x1e0/0x92f [zfs]
[   17.081018]  [<ffffffffc04a58f1>] __thread_create+0x18a/0x197 [spl]
[   17.081019]  [<ffffffffc04a5885>] ? __thread_create+0x11e/0x197 [spl]
[   17.081021]  [<ffffffff9804a6ef>] kthread+0xcd/0xd5
[   17.081022]  [<ffffffff9804a622>] ? __kthread_parkme+0x5c/0x5c
[   17.081024]  [<ffffffff983a9bac>] ret_from_fork+0x7c/0xb0
[   17.081025]  [<ffffffff9804a622>] ? __kthread_parkme+0x5c/0x5c
[   17.081033] Code: 48 83 c4 18 5b 5d c3 55 48 89 f0 48 89 e5 41 57 49 89 d7 41 56 4d 89 c6 41 55 41 54 45 89 cc 4c 8d 4d c8 53 48 89 fb 48 83 ec 48 <41> 83 78 18 00 48 89 75 b0 48 89 4d a8 b9 08 00 00 00 48 0f 45
[   17.081039] RIP  [<ffffffffc08a8c7b>] zap_create_claim+0x9e/0x274 [zfs]
[   17.081040]  RSP <ffff8800cf41fba8>
[   17.081040] CR2: 0000000000000018
[   17.081041] ---[ end trace ae80b176568fd521 ]---

[behlendorf]

@ari This is a duplicate of #2946. It was caused by a bug in the Gentoo ZFS packages, if you manually build ZFS directly from the master github source you won't see this issue. I thought @ryao, the Gentoo maintainer, already updated the Gentoo packages to address this but I'm not 100% certain.

[ari]

My review of that other ticket seems to indicate that there is no update to Gentoo packages since last December. Thanks for the pointer though, I'll close this ticket.