On Mon, Oct 31 2011 at 9:40am -0400, Heiko Carstens <heiko.carstens@xxxxxxxxxx> wrote: > On Mon, Oct 31, 2011 at 09:21:58AM -0400, Mike Snitzer wrote: > > > > It _looks_ like we do not hit the BUG_ON() that. This time we get this instead: > > > > > > > > [ 4024.937870] Unable to handle kernel pointer dereference at virtual kernel address 000003e004d41000 > > > > [ 4024.937886] Oops: 0011 [#1] PREEMPT SMP DEBUG_PAGEALLOC > > > > [ 4024.937899] Modules linked in: dm_round_robin sunrpc ipv6 qeth_l2 binfmt_misc dm_multipath scsi_dh dm_mod qeth ccwgroup [las > > > > t unloaded: scsi_wait_scan] > > > > [ 4024.937925] CPU: 1 Not tainted 3.0.7-50.x.20111021-s390xdefault #1 > > > > [ 4024.937930] Process ksoftirqd/1 (pid: 1942, task: 0000000079c6c750, ksp: 0000000073adfc50) > > > > [ 4024.937936] Krnl PSW : 0704000180000000 000003e00126263a (dm_softirq_done+0x72/0x140 [dm_mod]) > > > > [ 4024.937959] R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:0 CC:0 PM:0 EA:3 > > > > [ 4024.937966] Krnl GPRS: 000000007b9156b0 000003e004d41100 000000000e14b600 000000000000006d > > > > [ 4024.937971] 00000000715332b0 000000000c140ce8 000000000090d2ef 0000000000000005 > > > > [ 4024.937977] 0000000000000001 0000000000000101 000000000c140d00 0000000000000000 > > > > [ 4024.937983] 000003e001260000 000003e00126f098 0000000073adfd08 0000000073adfcb8 > > > > [ 4024.938001] Krnl Code: 000003e00126262a: f0a0000407f1 srp 4(11,%r0),2033,0 > > > > [ 4024.938009] 000003e001262630: e31050080004 lg %r1,8(%r5) > > > > [ 4024.938017] 000003e001262636: 58b05180 l %r11,384(%r5) > > > > [ 4024.938024] >000003e00126263a: e31010080004 lg %r1,8(%r1) > > > > [ 4024.938031] 000003e001262640: e31010500004 lg %r1,80(%r1) > > > > [ 4024.938038] 000003e001262646: b9020011 ltgr %r1,%r1 > > > > [ 4024.938045] 000003e00126264a: a784ffdf brc 8,3e001262608 > > > > [ 4024.938053] 000003e00126264e: e32050080004 lg %r2,8(%r5) > > > > [ 4024.938060] Call Trace: > > > > [ 4024.938063] ([<070000000040716c>] 0x70000000040716c) > > > > [ 4024.938069] [<000000000040d29c>] blk_done_softirq+0xd4/0xf0 > > > > [ 4024.938080] [<00000000001587c2>] __do_softirq+0xda/0x398 > > > > [ 4024.938088] [<0000000000158ba0>] run_ksoftirqd+0x120/0x23c > > > > [ 4024.938095] [<000000000017c2aa>] kthread+0xa6/0xb0 > > > > [ 4024.938102] [<000000000061970e>] kernel_thread_starter+0x6/0xc > > > > [ 4024.938112] [<0000000000619708>] kernel_thread_starter+0x0/0xc > > > > [ 4024.938118] INFO: lockdep is turned off. > > > > [ 4024.938121] Last Breaking-Event-Address: > > > > [ 4024.938124] [<000003e001262600>] dm_softirq_done+0x38/0x140 [dm_mod] > > > > [ 4024.938135] > > > > [ 4024.938139] Kernel panic - not syncing: Fatal exception in interrupt > > > > [ 4024.938144] CPU: 1 Tainted: G D 3.0.7-50.x.20111021-s390xdefault #1 > > > > [ 4024.938150] Process ksoftirqd/1 (pid: 1942, task: 0000000079c6c750, ksp: 0000000073adfc50) > > > > [ 4024.938155] 0000000073adf958 0000000073adf8d8 0000000000000002 0000000000000000 > > > > [ 4024.938164] 0000000073adf978 0000000073adf8f0 0000000073adf8f0 000000000061386a > > > > [ 4024.938174] 0000000000000000 0000000000000000 0000000000000005 0000000000100ec6 > > > > [ 4024.938184] 000000000000000d 000000000000000c 0000000073adf940 0000000000000000 > > > > [ 4024.938194] 0000000000000000 0000000000100a18 0000000073adf8d8 0000000073adf918 > > > > [ 4024.938205] Call Trace: > > > > [ 4024.938208] ([<0000000000100926>] show_trace+0xee/0x144) > > > > [ 4024.938216] [<0000000000613694>] panic+0xb0/0x234 > > > > [ 4024.938224] [<0000000000100ec6>] die+0x15a/0x168 > > > > [ 4024.938230] [<000000000011fb9e>] do_no_context+0xba/0xf8 > > > > [ 4024.938306] [<000000000061c074>] do_dat_exception+0x378/0x3e4 > > > > [ 4024.938314] [<0000000000619e02>] pgm_exit+0x0/0x4 > > > > [ 4024.938319] [<000003e00126263a>] dm_softirq_done+0x72/0x140 [dm_mod] > > > > [ 4024.938329] ([<070000000040716c>] 0x70000000040716c) > > > > [ 4024.938334] [<000000000040d29c>] blk_done_softirq+0xd4/0xf0 > > > > [ 4024.938341] [<00000000001587c2>] __do_softirq+0xda/0x398 > > > > [ 4024.938347] [<0000000000158ba0>] run_ksoftirqd+0x120/0x23c > > > > [ 4024.938354] [<000000000017c2aa>] kthread+0xa6/0xb0 > > > > [ 4024.938360] [<000000000061970e>] kernel_thread_starter+0x6/0xc > > > > [ 4024.938366] [<0000000000619708>] kernel_thread_starter+0x0/0xc > > > > [ 4024.938373] INFO: lockdep is turned off. > > > > > > > > So we thought we might as well upgrade to 3.1 but immediately got a > > > > > > > > kernel BUG at block/blk-flush.c:323! > > > > > > > > which was handled here https://lkml.org/lkml/2011/10/4/105 and > > > > here https://lkml.org/lkml/2011/10/12/408 . > > > > > > > > But no patches for that one went upstream AFAICS. > > > > > > Well, all I can say is "hm". You put only a BUG_ON() in the code, which > > > wasn't triggered, but now we get a completely different oops. However, > > > I think it does point to the dm barrier handling code. Can you turn off > > > barriers and see if all oopses go away? > > > > There are two 3.1-stable fixes from Jeff Moyer that Jens staged for > > Linus to pick up (but seems Jens hasn't sent his 3.2 pull to Linus yet): > > > > http://git.kernel.dk/?p=linux-block.git;a=commit;h=8f02b3a09b1b7d2a4d24b8cd7008f2a441f19a14 > > http://git.kernel.dk/?p=linux-block.git;a=commit;h=f26d8f0562da76731cb049943a0e9d9fa81d946a > > Those two fixes would only address the "kernel BUG at block/blk-flush.c:323!" but not the > crash report above, right? Right. > Since looking at the changelog they refer to a patch that went in with 3.1-rc1 while the > crash report above is with 3.0.7. Oh well... Good data point. This is the second request-based DM report I've seen now with 3.0 (first was with fedora on btrfs and request-based DM). Will look closer but it should be noted that DM didn't change significantly in 3.0. So it is likely a lingering oversight from the block changes introduced for onstack plugging (from 2.6.39) or some other change. -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
