Hi, I''m experimenting with btrfs on top of zvol block device (using zfsonlinux), and got oops on a simple mount test. While I''m sure that zfsonlinux is somehow also at fault here (since the same test with zram works fine), the oops only shows things btrfs-related without any usable mention of zfs/zvol. Could anyone help me interpret the kernel logs, which btrfs-zvol interaction is at fault, so I can pass it on to zfs guys to work on their side as well? Thanks. The test is creating a sparse 100G block device (zfs create -V 100G -s -o volblocksize=4k rpool/vbd/test1), format it (mkfs.btrfs /dev/zvol/rpool/vbd/test1), and mount it. Oops occured, and the mount process stuck. Same thing happens on ubuntu precise''s kernel 3.2 and quantal''s 3.5. What''s interesting is: - if I use ext4 (instead of btrfs) on the zvol, it works just fine - if I add a layer on top of zvol (losetup, or iscsi export-import) then btrfs works just fine. Syslog shows this (from Ubuntu''s 3.2 kernel): #====Aug 31 20:30:13 DELL kernel: [34307.828311] zd0: unknown partition table Aug 31 20:30:34 DELL kernel: [34328.129249] device fsid cfd88ff9-def8-4d1f-9435-65becd5fa2b7 devid 1 transid 4 /dev/zd0 Aug 31 20:30:34 DELL kernel: [34328.134001] btrfs: disk space caching is enabled Aug 31 20:30:34 DELL kernel: [34328.135701] BUG: unable to handle kernel NULL pointer dereference at (null) Aug 31 20:30:34 DELL kernel: [34328.137200] IP: [<ffffffffa0068439>] extent_range_uptodate+0x59/0xe0 [btrfs] Aug 31 20:30:34 DELL kernel: [34328.138759] PGD 0 Aug 31 20:30:34 DELL kernel: [34328.140248] Oops: 0000 [#1] SMP Aug 31 20:30:34 DELL kernel: [34328.141777] CPU 3 Aug 31 20:30:34 DELL kernel: [34328.141811] Modules linked in: ses enclosure ppp_mppe ppp_async crc_ccitt pci_stub vboxpci(O) vboxnetadp(O) vboxnetflt (O) vboxdrv(O) arc4 ath9k mac80211 radeon uvcvideo snd_hda_codec_hdmi ath9k_common snd_hda_codec_realtek ath9k_hw videodev ipt_MASQUERADE xt_state ipt able_nat nf_nat v4l2_compat_ioctl32 i915 nf_conntrack_ipv4 nf_conntrack iptable_filter nf_defrag_ipv4 ip_tables dm_multipath dummy x_tables bnep ath3k btusb bridge rfcomm bluetooth snd_hda_intel snd_hda_codec stp joydev ath snd_hwdep ttm snd_pcm mei(C) drm_kms_helper drm snd_seq_midi snd_rawmidi snd _seq_midi_event dell_wmi sparse_keymap snd_seq dell_laptop wmi snd_timer i2c_algo_bit video psmouse snd_seq_device cfg80211 snd mac_hid serio_raw soun dcore dcdbas snd_page_alloc parport_pc ppdev lp parport binfmt_misc zfs(P) zcommon(P) znvpair(P) zavl(P) zunicode(P) spl(O) ums_realtek uas r8169 btrf s zlib_deflate libcrc32c usb_storage Aug 31 20:30:34 DELL kernel: [34328.155820] Aug 31 20:30:34 DELL kernel: [34328.157974] Pid: 15887, comm: btrfs-endio-met Tainted: P C O 3.2.0-29-generic #46-Ubuntu Dell Inc. De ll System Inspiron N4110/03NKW8 Aug 31 20:30:34 DELL kernel: [34328.160283] RIP: 0010:[<ffffffffa0068439>] [<ffffffffa0068439>] extent_range_uptodate+0x59/0xe0 [btrfs] Aug 31 20:30:34 DELL kernel: [34328.162700] RSP: 0018:ffff8800351dfde0 EFLAGS: 00010246 Aug 31 20:30:34 DELL kernel: [34328.165099] RAX: 0000000000000000 RBX: 0000000001401000 RCX: 0000000000000000 Aug 31 20:30:34 DELL kernel: [34328.167548] RDX: 0000000000000001 RSI: 0000000000001401 RDI: 0000000000000000 Aug 31 20:30:34 DELL kernel: [34328.169989] RBP: ffff8800351dfe00 R08: 0000000000000000 R09: ffff880067021418 Aug 31 20:30:34 DELL kernel: [34328.172474] R10: ffff8800b680d010 R11: 0000000000001000 R12: ffff88011d997bf0 Aug 31 20:30:34 DELL kernel: [34328.174922] R13: 0000000001401fff R14: ffff880031c45c00 R15: ffff88011aedc9b0 Aug 31 20:30:34 DELL kernel: [34328.177401] FS: 0000000000000000(0000) GS:ffff88013e6c0000(0000) knlGS:0000000000000000 Aug 31 20:30:34 DELL kernel: [34328.179904] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b Aug 31 20:30:34 DELL kernel: [34328.182426] CR2: 0000000000000000 CR3: 00000001291e0000 CR4: 00000000000406e0 Aug 31 20:30:34 DELL kernel: [34328.185005] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 Aug 31 20:30:34 DELL kernel: [34328.187602] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Aug 31 20:30:34 DELL kernel: [34328.190246] Process btrfs-endio-met (pid: 15887, threadinfo ffff8800351de000, task ffff880031c45c00) Aug 31 20:30:34 DELL kernel: [34328.193171] Stack: Aug 31 20:30:34 DELL kernel: [34328.196542] ffff8800351dfdf0 ffff880088ff6638 ffff8800b61953c0 ffff88011cbbb000 Aug 31 20:30:34 DELL kernel: [34328.199469] ffff8800351dfe10 ffffffffa004224d ffff8800351dfe40 ffffffffa00422d6 Aug 31 20:30:34 DELL kernel: [34328.202295] ffff8800351dfe88 ffff88011aedc960 ffff8800351dfe88 ffff8800351dfe98 Aug 31 20:30:34 DELL kernel: [34328.204685] Call Trace: Aug 31 20:30:34 DELL kernel: [34328.206645] [<ffffffffa004224d>] bio_ready_for_csum.isra.107+0xbd/0xc0 [btrfs] Aug 31 20:30:34 DELL kernel: [34328.208591] [<ffffffffa00422d6>] end_workqueue_fn+0x86/0xa0 [btrfs] Aug 31 20:30:34 DELL kernel: [34328.210565] [<ffffffffa00714e0>] worker_loop+0xa0/0x2b0 [btrfs] Aug 31 20:30:34 DELL kernel: [34328.212531] [<ffffffff8165737c>] ? __schedule+0x3cc/0x6f0 Aug 31 20:30:34 DELL kernel: [34328.214540] [<ffffffffa0071440>] ? check_pending_worker_creates.isra.1+0xf0/0xf0 [btrfs] Aug 31 20:30:34 DELL kernel: [34328.216563] [<ffffffff81089fbc>] kthread+0x8c/0xa0 Aug 31 20:30:34 DELL kernel: [34328.218604] [<ffffffff81664034>] kernel_thread_helper+0x4/0x10 Aug 31 20:30:34 DELL kernel: [34328.220886] [<ffffffff81089f30>] ? flush_kthread_worker+0xa0/0xa0 Aug 31 20:30:34 DELL kernel: [34328.223019] [<ffffffff81664030>] ? gs_change+0x13/0x13 Aug 31 20:30:34 DELL kernel: [34328.225103] Code: 01 f0 48 09 f0 a9 ff 0f 00 00 75 4e 49 39 dd b8 01 00 00 00 72 36 0f 1f 40 00 49 8b 7c 24 18 48 89 de 48 c1 ee 0c e8 c7 f3 0a e1 <48> 8b 10 83 e2 08 74 5f 48 89 c7 48 81 c3 00 10 00 00 e8 10 b2 Aug 31 20:30:34 DELL kernel: [34328.229876] RIP [<ffffffffa0068439>] extent_range_uptodate+0x59/0xe0 [btrfs] Aug 31 20:30:34 DELL kernel: [34328.232272] RSP <ffff8800351dfde0> Aug 31 20:30:34 DELL kernel: [34328.234619] CR2: 0000000000000000 Aug 31 20:30:34 DELL kernel: [34328.246500] ---[ end trace 1744873168fb9394 ]--- #=== -- Fajar -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html