4.4-rc2 crash: block related

From: Mika PenttilÃ
Date: Wed Nov 25 2015 - 01:20:50 EST

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Hi,

With recent block layer pull i see a 100% repeatable crash on boot while
mounting roots (ext4 partition on eMMC, with cfq io scheduler).

---

5.674294] Unable to handle kernel NULL pointer dereference at virtual
address 00000004
[ 5.682399] pgd = a8ca4000
[ 5.685113] [00000004] *pgd=38a5e831, *pte=00000000, *ppte=00000000
[ 5.691428] Internal error: Oops: 17 [#1] PREEMPT SMP ARM
[ 5.696830] Modules linked in: st_drv
[ 5.700533] CPU: 1 PID: 221 Comm: mount Not tainted 4.4.0-rc2 #49
[ 5.706631] Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree)
[ 5.713163] task: a88e2ac0 ti: a88d4000 task.ti: a88d4000
[ 5.718578] PC is at cfq_init_prio_data+0x8/0xec
[ 5.723206] LR is at cfq_insert_request+0x28/0x4f0
[ 5.723211] pc : [<8024bf9c>] lr : [<8024e768>] psr: 600d0093
[ 5.723211] sp : a88d5bc0 ip : 00000000 fp : a8ab5400
[ 5.723219] r10: 00000001 r9 : a617f4c0 r8 : 80b6359c
[ 5.723223] r7 : 80b62100 r6 : a873e200 r5 : a885ac30 r4 : 00000000
[ 5.723226] r3 : a88d5bc0 r2 : a89106c0 r1 : 00000000 r0 : 00000000
[ 5.723232] Flags: nZCv IRQs off FIQs on Mode SVC_32 ISA ARM
Segment user
[ 5.723235] Control: 10c5387d Table: 38ca404a DAC: 00000055
[ 5.723239] Process mount (pid: 221, stack limit = 0xa88d4210)
[ 5.723242] Stack: (0xa88d5bc0 to 0xa88d6000)
[ 5.723251] 5bc0: 00000000 a885ac30 a873e200 8024e768 a87c0000
a885ac30 00000005 a88d4000
[ 5.723257] 5be0: 80b6359c a617f4c0 00000001 8023817c ffffffff
a89106c0 a885ac30 00000000
[ 5.723263] 5c00: a89106c0 ffffffff a87c0000 8023654c 00000000
00000000 a8ab5400 a89106c0
[ 5.723269] 5c20: 00000008 00001411 f0000000 80236680 a88d5c44
a87c0168 a617f4c0 a81a45c0
[ 5.723276] 5c40: 00000001 02400000 80b6359c a617f4c0 00000001
80231b04 a00d0013 0000000f
[ 5.723282] 5c60: a617f4c0 a89106c0 00001411 f0000000 80b6359c
a617f4c0 00000001 80110950
[ 5.723288] 5c80: a617f4c0 00000001 00001411 80b6370c 80b6359c
80112490 a8b35c00 00000000
[ 5.723295] 5ca0: 80b63658 801602e4 0205a9d9 00000000 a62b4738
a8ab5400 a8b35c00 a8b36000
[ 5.723301] 5cc0: 00000000 00000000 a8b36000 a8ab5400 a88d5e8c
80162644 a62621e8 800f7004
[ 5.723307] 5ce0: a88d5e8c 806dd610 a62621e8 a617f4c0 a8b35c00
a8b36000 00000001 80165480
[ 5.723313] 5d00: 00000000 00000000 a88d5d58 a88d5d50 a87f2a90
a88d5d54 01897158 800ec9dc
[ 5.723319] 5d20: 00000000 00000002 00000000 a88d5dc8 00000001
a88d5dc0 00000001 a6023000
[ 5.723325] 5d40: a88d5d90 a88d5d88 a8887f10 a88d5d8c 01897158
800ec8d0 a8887f10 00000004
[ 5.723332] 5d60: 00000000 a88d5dc0 a88d5dc0 a6029110 00000001
a80fd000 a88d5d8c a8744800
[ 5.723338] 5d80: 00000000 00000000 00000001 00000980 0000b67c
00000000 00000001 800bf478
[ 5.723343] 5da0: a615e490 00000001 0000006c a8102db0 00000000
00000001 0000000a 00000001
[ 5.723349] 5dc0: 0000ffff 00000000 00000000 00000000 0000002b
a82ec200 80b6e735 00000004
[ 5.723355] 5de0: 00000000 00000000 a8ab5400 00000000 a8b36264
00000000 001013d0 00000000
[ 5.723361] 5e00: 00000001 00000000 a8b36000 00000000 00001000
a8b35e88 00000000 00000000
[ 5.723366] 5e20: 00000000 00000000 a8ab5594 00000000 80be3e54
00000000 00000000 00000000
[ 5.723372] 5e40: 00000000 00004003 00000000 80b70288 01897158
8025e5bc a6298e00 a88d5e6c
[ 5.723378] 5e60: 3b9aca00 00000009 a6298e00 a6298e74 a8b35c00
a6298e00 00000083 00000000
[ 5.723384] 5e80: 00000000 80b70288 01897158 800e6324 a6298e00
800c0050 62636d6d 70306b6c
[ 5.723391] 5ea0: a8000035 800d0013 00000004 80be3e2c a8dca80e
00000000 00000001 8015f030
[ 5.723397] 5ec0: a8dca800 00000000 80b70288 80b70288 80b6aeb0
8015f048 801636d8 a8ab1a48
[ 5.723403] 5ee0: 01897158 800e6f14 00000000 a8dca800 a8ab19c0
a8dca800 00000000 80b70288
[ 5.723409] 5f00: 00000000 800febbc 00000000 00000020 00000000
a8dca800 a8dca840 80101a14
[ 5.723416] 5f20: 00000000 80b60be0 a8001f00 024000c0 000088c5
800df23c 007fffff a8dca800
[ 5.723421] 5f40: a87f2a90 a6138cc0 c0ed0000 a8dca800 0000000f
00000000 0000000f a8dca840
[ 5.723428] 5f60: a8dca800 00000000 018971a0 c0ed0000 a88d4000
00000000 01897158 801027e4
[ 5.723434] 5f80: 00000000 28936a1b 563c86d0 00000000 00000000
76f35688 c0ed0000 00000015
[ 5.723440] 5fa0: 8000f6a4 8000f500 00000000 76f35688 01897188
018971a0 01897158 c0ed0000
[ 5.723447] 5fc0: 00000000 76f35688 c0ed0000 00000015 018971a0
01897188 76f36dac 01897158
[ 5.723453] 5fe0: 76e56dc0 7eedcc30 76f09e70 76e56dd0 600d0010
01897188 00000000 00000000
[ 5.723473] [<8024bf9c>] (cfq_init_prio_data) from [<8024e768>]
(cfq_insert_request+0x28/0x4f0)
[ 5.723484] [<8024e768>] (cfq_insert_request) from [<8023817c>]
(blk_queue_bio+0x254/0x260)
[ 5.723500] [<8023817c>] (blk_queue_bio) from [<8023654c>]
(generic_make_request+0xcc/0x17c)
[ 5.723510] [<8023654c>] (generic_make_request) from [<80236680>]
[ 5.723527] [<80236680>] (submit_bio) from [<80110950>]
(submit_bh_wbc+0x10c/0x144)
[ 5.723537] [<80110950>] (submit_bh_wbc) from [<80112490>]
(__sync_dirty_buffer+0x90/0x114)
[ 5.723550] [<80112490>] (__sync_dirty_buffer) from [<801602e4>]
(ext4_commit_super+0x1c8/0x290)
[ 5.723561] [<801602e4>] (ext4_commit_super) from [<80162644>]
(ext4_setup_super+0xe8/0x1d0)
[ 5.723569] [<80162644>] (ext4_setup_super) from [<80165480>]
(ext4_fill_super+0x1da8/0x32b8)
[ 5.723580] [<80165480>] (ext4_fill_super) from [<800e6324>]
(mount_bdev+0x168/0x190)
[ 5.723588] [<800e6324>] (mount_bdev) from [<8015f048>]
(ext4_mount+0x18/0x20)
[ 5.723596] [<8015f048>] (ext4_mount) from [<800e6f14>]
(mount_fs+0x14/0xa4)
[ 5.723604] [<800e6f14>] (mount_fs) from [<800febbc>]
(vfs_kern_mount+0x4c/0xf4)
[ 5.723614] [<800febbc>] (vfs_kern_mount) from [<80101a14>]
(do_mount+0x1a0/0xc24)
[ 5.723622] [<80101a14>] (do_mount) from [<801027e4>]
(SyS_mount+0x74/0xa0)
[ 5.723635] [<801027e4>] (SyS_mount) from [<8000f500>]
(ret_fast_syscall+0x0/0x34)
[ 5.723642] Code: e3a00000 e8bd8070 e92d4070 e1a0300d (e5902004)
[ 5.723647] ---[ end trace 4087b61c23235e2b ]---
[ 5.723651] Kernel panic - not syncing: Fatal exception
---

Cause seems to be this commit :

commit 1b2ff19e6a957b1ef0f365ad331b608af80e932e
Author: Jan Kara <jack@xxxxxxxx>
Date: Thu Nov 12 14:25:52 2015 +0100

blk-flush: Queue through IO scheduler when flush not required

git show 1b2ff19e6a957b1ef0f365ad331b608af80e932e:

diff --git a/block/blk-flush.c b/block/blk-flush.c
index 9c423e5..c81d56e 100644
--- a/block/blk-flush.c
+++ b/block/blk-flush.c
@@ -422,7 +422,7 @@ void blk_insert_flush(struct request *rq)
if (q->mq_ops) {
blk_mq_insert_request(rq, false, false, true);
} else
- list_add_tail(&rq->queuelist, &q->queue_head);
+ q->elevator->type->ops.elevator_add_req_fn(q, rq);
return;
}

With this reverted it boots normally.

Thanks,
Mika
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Next message: Jason Gunthorpe: "Re: [PATCH 2/9] IB: add a proper completion queue abstraction"
Previous message: Shawn Guo: "Re: [PATCH v5 5/5] ARM: dts: TS-4800: add basic device tree"
Next in thread: Jan Kara: "Re: Fwd: 4.4-rc2 crash: block related"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]