Re: kernel 4.8-rc5 kernel BUG at block/blk-core.c:2032!

[Shaohua Li <shli@fb.com>]

On Fri, Sep 09, 2016 at 08:03:42PM +0200, Stefan Priebe - Profihost AG wrote:
> Am 08.09.2016 um 19:33 schrieb Shaohua Li:
> > On Thu, Sep 08, 2016 at 10:16:59AM -0600, Jens Axboe wrote:
> >> On 09/08/2016 02:23 AM, Stefan Priebe - Profihost AG wrote:
> >>> Hi,
> >>>
> >>> while trying Kernel 4.8-rc5 my raid5 breaks every few minutes.
> >>>
> >>> Trace:
> >>> ------------[ cut here ]------------
> >>> kernel BUG at block/blk-core.c:2032!
> >>> invalid opcode: 0000 [#1] SMP
> >>> Modules linked in: netconsole ipt_REJECT nf_reject_ipv4 xt_multiport
> >>> iptable_filter ip_tables x_tables 8021q garp bonding sb_edac edac_core
> >>> x86_pkg_temp_thermal coretemp kvm_intel kvm i2c_i801 irqbypass i2c_smbus
> >>> ipmi_si crc32_pclmul i2c_core ghash_clmulni_intel shpchp ipmi_msghandler
> >>> button loop fuse btrfs dm_mod raid10 raid0 multipath linear raid456
> >>> async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq
> >>> raid1 md_mod sg sd_mod ixgbe i40e mdio usbhid ehci_pci ehci_hcd ahci
> >>> usbcore ptp libahci usb_common megaraid_sas pps_core
> >>> CPU: 8 PID: 1105 Comm: md0_raid5 Not tainted 4.8.0-rc5-00003-g3abda5c #2
> >>> Hardware name: Supermicro X10DRH/X10DRH-iT, BIOS 1.0c 02/18/2015
> >>> task: ffff97de5e1e0000 task.stack: ffff97de597a0000
> >>> RIP: 0010:[<ffffffffbc3b3890>] [<ffffffffbc3b3890>]
> >>> generic_make_request+0x1c0/0x1d0
> >>> RSP: 0018:ffff97de597a3aa0 EFLAGS: 00010286
> >>> RAX: ffff97de5e1e0000 RBX: ffff97dd227e5030 RCX: 0000000000000000
> >>> RDX: ffffffffc0000001 RSI: 0000000000000001 RDI: ffff97de5e7d9db8
> >>> RBP: ffff97de597a3ad8 R08: 0000000000000008 R09: 0000000000000000
> >>> R10: 0000000000000000 R11: 0000000000000001 R12: 00000000ffffffff
> >>> R13: ffff97de5aa20c00 R14: 00000000000002f0 R15: ffff97e65dce0e00
> >>> FS: 0000000000000000(0000) GS:ffff97e67f200000(0000) knlGS:0000000000000000
> >>> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> >>> CR2: 00007f0e4e1ec000 CR3: 0000000078c06000 CR4: 00000000001406e0Stack:
> >>> ffff97de597a3b50 0000000000001000 0000000000000000 ffff97dd227e4c80
> >>> ffff97de5aa20c00 00000000000002f0 ffff97e65dce0e00 ffff97de597a3ba0
> >>> ffffffffc02595db ffffffffc025e04b 00000001597a3b01 0000000200000006
> >>> Call Trace:
> >>> [<ffffffffc02595db>] ops_run_io+0x3bb/0x990 [raid456]
> >>> [<ffffffffc025e04b>] ? raid_run_ops+0xefb/0x1520 [raid456]
> >>> [<ffffffffc0261d16>] handle_stripe+0x9a6/0x2280 [raid456]
> >>> [<ffffffffbc0ae6b2>] ? default_wake_function+0x12/0x20
> >>> [<ffffffffbc0c7d22>] ? autoremove_wake_function+0x12/0x40
> >>> [<ffffffffc0263783>] handle_active_stripes.isra.54+0x193/0x4b0 [raid456]
> >>> [<ffffffffc02571d5>] ? __release_stripe+0x15/0x20 [raid456]
> >>> [<ffffffffc0263f49>] raid5d+0x4a9/0x740 [raid456]
> >>> [<ffffffffbc0e88f0>] ? init_timer_key+0xa0/0xa0
> >>> [<ffffffffc019a7eb>] md_thread+0x12b/0x130 [md_mod]
> >>> [<ffffffffbc0c7d10>] ? wait_woken+0x90/0x90
> >>> [<ffffffffc019a6c0>] ? find_pers+0x70/0x70 [md_mod]
> >>> [<ffffffffbc0a395b>] kthread+0xdb/0x100
> >>> [<ffffffffbc6de57f>] ret_from_fork+0x1f/0x40
> >>> [<ffffffffbc0a3880>] ? kthread_park+0x60/0x60
> >>> Code: bd 70 08 00 00 f0 49 83 ad 70 08 00 00 01 74 05 e9 5a ff ff ff 41
> >>> ff 95 80 08 00 00 e9 4e ff ff ff 48 c7 40 08 00 00 00 00 eb 8c <0f> 0b
> >>> 66 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00
> >>> RIP [<ffffffffbc3b3890>] generic_make_request+0x1c0/0x1d0
> >>> RSP <ffff97de597a3aa0>
> >>> ---[ end trace 457dbe5e9cdd3473 ]---
> >>
> >> CC'ing Shaohua - this is:
> >>
> >>         BUG_ON(bio->bi_next);
> >>
> >> which doesn't look healthy.
> > 
> > Hi Stefan,
> > does below patch help? Looks there is a race condition introduced recently.
> 
> Yes this one fixes it.

Thanks, will push to Linus soon.