zpool import causes kernel oops

[peachpine]

with 3.2.8-3.fc16.x86_64 kernel using zfs/spl compiled today:

"zpool import mainpool"

[ 436.023409] SPL: Loaded module v0.6.0, using hostid 0x0a0a0a0a
[ 436.025137] zunicode: module license 'CDDL' taints kernel.
[ 436.025141] Disabling lock debugging due to kernel taint
[ 436.092890] ZFS: Loaded module v0.6.0, ZFS pool version 28, ZFS filesystem version 5
[ 450.443498] padlock_sha: VIA PadLock Hash Engine not detected.
[ 482.402290] BUG: unable to handle kernel NULL pointer dereference at 0000000000000018
[ 482.402398] IP: [] dmu_buf_hold_array_by_dnode+0x311/0x4b0 [zfs]
[ 482.402526] PGD 3f80d067 PUD 3f80c067 PMD 0
[ 482.402654] Oops: 0000 [#1] SMP
[ 482.402750] CPU 1
[ 482.402783] Modules linked in: sha256_generic dm_crypt zfs(P) zcommon(P) znvpair(P) zavl(P) zunicode(P) spl(O) zlib_deflate tun lockd ip6t_REJECT ipt_MASQUERADE nf_conntrack_ipv6 nf_defrag_ipv6 iptable_nat nf_nat nf_conntrack_ipv4 xt_state ip6table_filter nf_conntrack ip6_tables nf_defrag_ipv4 hwmon_vid snd_hda_codec_hdmi snd_hda_codec_via snd_hda_intel snd_hda_codec snd_hwdep snd_seq snd_seq_device snd_pcm snd_timer r8169 snd sp5100_tco ppdev soundcore mii i2c_piix4 snd_page_alloc parport_pc k10temp i2c_core edac_core edac_mce_amd shpchp asus_atk0110 parport microcode sunrpc uinput xfs pata_acpi ata_generic pata_atiixp wmi [last unloaded: scsi_wait_scan]
[ 482.403179]
[ 482.403179] Pid: 30712, comm: txg_sync Tainted: P O 3.2.8-3.fc16.x86_64 #1 System manufacturer System Product Name/M4A88T-M
[ 482.403179] RIP: 0010:[] [] dmu_buf_hold_array_by_dnode+0x311/0x4b0 [zfs]
[ 482.403179] RSP: 0018:ffff880032835a10 EFLAGS: 00010206
[ 482.403179] RAX: 0000000000000000 RBX: ffff88003c04ae60 RCX: 0000000000000000
[ 482.403179] RDX: 00000000000000c6 RSI: 0000000000001548 RDI: ffffffffa0425a98
[ 482.403179] RBP: ffff880032835a80 R08: 0000000000001548 R09: 0000000000000048
[ 482.403179] R10: ffff8800328359d8 R11: 0000000000000000 R12: ffff88003c04ae68
[ 482.403179] R13: 0000000000000048 R14: 0000000000001548 R15: ffff88003c031a48
[ 482.403179] FS: 00007fef1f265c00(0000) GS:ffff88006fc40000(0000) knlGS:0000000000000000
[ 482.403179] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[ 482.403179] CR2: 0000000000000018 CR3: 000000003f80a000 CR4: 00000000000006e0
[ 482.403179] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 482.403179] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
[ 482.403179] Process txg_sync (pid: 30712, threadinfo ffff880032834000, task ffff88004aedae60)
[ 482.403179] Stack:
[ 482.403179] 00000000000001a4 ffff880032835b2c ffff880066634360 ffff88003c7026d0
[ 482.403179] ffff880066634368 0000000000000016 ffff880032835a50 ffffffffa041e6d8
[ 482.403179] ffffffffa041e6d8 0000000000000000 ffffffffa041e6d8 0000000000000048
[ 482.403179] Call Trace:
[ 482.403179] [] dmu_buf_hold_array+0x65/0x90 [zfs]
[ 482.403179] [] dmu_write+0x60/0x170 [zfs]
[ 482.403179] [] ? kmem_free_debug+0x4b/0x150 [spl]
[ 482.403179] [] space_map_sync+0x242/0x3e0 [zfs]
[ 482.403179] [] metaslab_sync+0x113/0x360 [zfs]
[ 482.403179] [] vdev_sync+0x6f/0x140 [zfs]
[ 482.403179] [] spa_sync+0x3eb/0x9f0 [zfs]
[ 482.403179] [] txg_sync_thread+0x2a5/0x470 [zfs]
[ 482.403179] [] ? txg_quiesce_thread+0x320/0x320 [zfs]
[ 482.403179] [] thread_generic_wrapper+0x78/0x90 [spl]
[ 482.403179] [] ? __thread_create+0x310/0x310 [spl]
[ 482.403179] [] kthread+0x8c/0xa0
[ 482.403179] [] kernel_thread_helper+0x4/0x10
[ 482.403179] [] ? kthread_worker_fn+0x190/0x190
[ 482.403179] [] ? gs_change+0x13/0x13
[ 482.403179] Code: e8 55 4e f5 ff 48 89 45 90 90 e9 ee fd ff ff 48 8b 43 38 48 8b 53 40 4d 89 e1 4c 8d 63 08 4d 89 f0 48 c7 c7 98 5a 42 a0 48 8b 00 <48> 8b 70 18 31 c0 e8 24 e7 05 00 4c 89 e7 e8 0c 61 25 e1 4c 8b
[ 482.403179] RIP [] dmu_buf_hold_array_by_dnode+0x311/0x4b0 [zfs]
[ 482.403179] RSP
[ 482.403179] CR2: 0000000000000018
[ 482.410061] ---[ end trace 49255b0698d7d0aa ]---

i think this pool is damaged because a large rsync transfer into it froze up and i had to do a hard powercycle to reboot, so that might be why it's not working. but i'm not sure how to help further

[behlendorf]

This has come up a few times before, see issues #321 and #332. It turns out this is a pretty common failure mode for a corrupted pool. You may be able to recover the data from the pool by using the readonly import option. Longer term we should certainly handle this issue more gracefully.

[behlendorf]

Closing as a duplicate of #1440.