On Tue, Nov 12, 2013 at 10:43:39AM +0800, majianpeng wrote: > When changed group_thread_cnt from sysfs entry, it met OOPS. > The kernel messages are: > [ 135.299021] BUG: unable to handle kernel NULL pointer dereference at (null) > [ 135.299073] IP: [<ffffffff815188ab>] handle_active_stripes+0x32b/0x440 > [ 135.299107] PGD 0 > [ 135.299122] Oops: 0000 [#1] SMP > [ 135.299144] Modules linked in: netconsole e1000e ptp pps_core > [ 135.299188] CPU: 3 PID: 2225 Comm: md0_raid5 Not tainted 3.12.0+ #24 > [ 135.299214] Hardware name: To Be Filled By O.E.M. To Be Filled By O.E.M./To be filled by O.E.M., BIOS 080015 11/09/2011 > [ 135.299255] task: ffff8800b9638f80 ti: ffff8800b77a4000 task.ti: ffff8800b77a4000 > [ 135.299283] RIP: 0010:[<ffffffff815188ab>] [<ffffffff815188ab>] handle_active_stripes+0x32b/0x440 > [ 135.299323] RSP: 0018:ffff8800b77a5c48 EFLAGS: 00010002 > [ 135.299344] RAX: ffff880037bb5c70 RBX: 0000000000000000 RCX: 0000000000000008 > [ 135.299371] RDX: ffff880037bb5cb8 RSI: 0000000000000001 RDI: ffff880037bb5c00 > [ 135.299398] RBP: ffff8800b77a5d08 R08: 0000000000000001 R09: 0000000000000000 > [ 135.299425] R10: ffff8800b77a5c98 R11: 00000000ffffffff R12: ffff880037bb5c00 > [ 135.299452] R13: 0000000000000000 R14: 0000000000000000 R15: ffff880037bb5c70 > [ 135.299479] FS: 0000000000000000(0000) GS:ffff88013fd80000(0000) knlGS:0000000000000000 > [ 135.299510] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b > [ 135.299532] CR2: 0000000000000000 CR3: 0000000001c0b000 CR4: 00000000000407e0 > [ 135.299559] Stack: > [ 135.299570] ffff8800b77a5c88 ffffffff8107383e ffff8800b77a5c88 ffff880037a64300 > [ 135.299611] 000000000000ec08 ffff880037bb5cb8 ffff8800b77a5c98 ffffffffffffffd8 > [ 135.299654] 000000000000ec08 ffff880037bb5c60 ffff8800b77a5c98 ffff8800b77a5c98 > [ 135.299696] Call Trace: > [ 135.299711] [<ffffffff8107383e>] ? __wake_up+0x4e/0x70 > [ 135.299733] [<ffffffff81518f88>] raid5d+0x4c8/0x680 > [ 135.299756] [<ffffffff817174ed>] ? schedule_timeout+0x15d/0x1f0 > [ 135.299781] [<ffffffff81524c9f>] md_thread+0x11f/0x170 > [ 135.299804] [<ffffffff81069cd0>] ? wake_up_bit+0x40/0x40 > [ 135.299826] [<ffffffff81524b80>] ? md_rdev_init+0x110/0x110 > [ 135.299850] [<ffffffff81069656>] kthread+0xc6/0xd0 > [ 135.299871] [<ffffffff81069590>] ? kthread_freezable_should_stop+0x70/0x70 > [ 135.299899] [<ffffffff81722ffc>] ret_from_fork+0x7c/0xb0 > [ 135.299923] [<ffffffff81069590>] ? kthread_freezable_should_stop+0x70/0x70 > [ 135.299951] Code: ff ff ff 0f 84 d7 fe ff ff e9 5c fe ff ff 66 90 41 8b b4 24 d8 01 00 00 45 31 ed 85 f6 0f 8e 7b fd ff ff 49 8b 9c 24 d0 01 00 00 <48> 3b 1b 49 89 dd 0f 85 67 fd ff ff 48 8d 43 28 31 d2 eb 17 90 > [ 135.300005] RIP [<ffffffff815188ab>] handle_active_stripes+0x32b/0x440 > [ 135.300005] RSP <ffff8800b77a5c48> > [ 135.300005] CR2: 0000000000000000 > [ 135.300005] ---[ end trace 504854e5bb7562ed ]--- > [ 135.300005] Kernel panic - not syncing: Fatal exception > > This because raid5d() can running when changed multi-thread resources. > After mddve_suspend(), the raid5d() can still on running. > But when change multi-thread resources in raid5_store_group_thread_cnt(), > it can't use conf->device_lock to protect. > > Signed-off-by: Jianpeng Ma <majianpeng@xxxxxxxxx> Reviewed-by: Shaohua Li <shli@xxxxxxxxxx> -- 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
