I have an arm board running kernel 2.6.39.4, with four disks partitioned into a number of RAID arrays. A power loss event appears to have clobbered the storage, and when the unit is rebooted, I see the following BUG_ON triggered soon after the RAID arrays are started (but before filesystems are mounted.) md/raid:md2: not clean -- starting background reconstruction md/raid:md2: device sda3 operational as raid disk 0 md/raid:md2: device sdd3 operational as raid disk 3 md/raid:md2: device sdc3 operational as raid disk 2 md/raid:md2: device sdb3 operational as raid disk 1 md/raid:md2: allocated 4218kB md/raid:md2: raid level 5 active with 4 out of 4 devices, algorithm 2 md2: detected capacity change from 0 to 2999619354624 mdadm: /dev/md2 has been started with 4 drives. md: resync of RAID array md2 md: minimum _guaranteed_ speed: 1000 KB/sec/disk. md: using maximum available idle IO bandwidth (but not more than 200000 KB/sec) for resync. md: using 128k window, over a total of 976438592 blocks. kernel BUG at kernel/workqueue.c:1196! Unable to handle kernel NULL pointer dereference at virtual address 00000000 pgd = c0004000 [00000000] *pgd=00000000 Internal error: Oops: 817 [#1] PREEMPT last sysfs file: /sys/devices/virtual/block/md2/md/stripe_cache_size Modules linked in: raid456 async_raid6_recov async_pq raid6_pq async_xor xor async_memcpy raid1 raid0 md_ mod raid_class sata_mv lm90 sd_mod ext4 crc16 ext3 mbcache jbd2 jbd nfs lockd sunrpc af_packet bonding e1 000 softdog rtc_m41t11 vp8xx_reset i2c_iop3xx CPU: 0 Not tainted (2.6.39.4-iv5 #1) pc : [<c0032458>] lr : [<c0032454>] psr: 60000093 sp : df867f98 ip : c0261a08 fp : 00000000 r10: c0256338 r9 : 00000009 r8 : c0256338 r7 : c0256338 r6 : c0282be0 r5 : df866000 r4 : c0256338 r3 : 00000000 r2 : df867f8c r1 : c0204f47 r0 : 0000002d Flags: nZCv IRQs off FIQs on Mode SVC_32 ISA ARM Segment kernel Control: 0400397f Table: 1d71c018 DAC: 00000035 Process kworker/0:1 (pid: 154, stack limit = 0xdf866270) Stack: (0xdf867f98 to 0xdf868000) 7f80: 0000000d c0051684 7fa0: 00000000 df8cdea0 df866000 c0054108 df82df30 df8cdea0 c0053e3c 00000013 7fc0: 00000000 00000000 00000000 c0057640 00000000 00000000 df8cdea0 00000000 7fe0: df867fe0 df867fe0 df82df30 c00575c4 c0030714 c0030714 849a653c a6d38502 Function entered at [<c0032458>] from [<c0051684>] Function entered at [<c0051684>] from [<c0054108>] Function entered at [<c0054108>] from [<c0057640>] Function entered at [<c0057640>] from [<c0030714>] Code: e59f0010 e1a01003 eb0700d6 e3a03000 (e5833000) ---[ end trace 4dd7435f9823dd59 ]--- note: kworker/0:1[154] exited with preempt_count 1 Unable to handle kernel paging request at virtual address fffffffc pgd = c0004000 [fffffffc] *pgd=1fffe821, *pte=00000000, *ppte=00000000 Internal error: Oops: 17 [#2] PREEMPT last sysfs file: /sys/devices/virtual/block/md2/md/stripe_cache_size Modules linked in: raid456 async_raid6_recov async_pq raid6_pq async_xor xor async_memcpy raid1 raid0 md_ mod raid_class sata_mv lm90 sd_mod ext4 crc16 ext3 mbcache jbd2 jbd nfs lockd sunrpc af_packet bonding e1 000 softdog rtc_m41t11 vp8xx_reset i2c_iop3xx CPU: 0 Tainted: G D (2.6.39.4-iv5 #1) pc : [<c00577b8>] lr : [<c00541bc>] psr: 00000093 sp : df867db8 ip : df8ff820 fp : df867ddc r10: df8ff8f4 r9 : df8ff818 r8 : df8ff970 r7 : df813d60 r6 : c0254c30 r5 : df8ff820 r4 : 00000000 r3 : 00000000 r2 : c0259c48 r1 : 00000000 r0 : df8ff820 Flags: nzcv IRQs off FIQs on Mode SVC_32 ISA ARM Segment user Control: 0400397f Table: 1d71c018 DAC: 00000015 Process kworker/0:1 (pid: 154, stack limit = 0xdf866270) Stack: (0xdf867db8 to 0xdf868000) 7da0: df866000 c01f4278 7dc0: df8ff820 ffffffff df866000 df813d60 df8ff8f4 df8ff8f4 00000001 c00432b0 7de0: c020505b df867de4 df867de4 df8ff93c df867e04 df866000 df867e52 00000035 The kernel continues generating diagnostics until the hardware watchdog resets the board. kernel/workqueue.c line 1196 corresponds to the following line in worker_enter_idle: BUG_ON(worker->flags & WORKER_IDLE); I have done quite a bit of system testing with this kernel and it seems to be very stable otherwise. Has anyone seen similar problems with RAID issues triggering this or similar BUG_ON statements in workqueue? I have done some extensive web searching and delving through the latest git repositories, but have not found anything that stands out so far. I shall scan the mailing lists, but if you could also reply directly to the email address below, it would be most appreciated. Kind Regards, Bruce Stenning, IndigoVision, b <dot> stenning <at> indigovision <dot> com Latest News at: http://www.indigovision.com/index.php/en/news.html -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
