BUG and Oops while trying to issue a discard to LVM on RAID1 md

From: Sitsofe Wheeler
Date: Tue Oct 04 2016 - 02:17:26 EST

While trying to do a discard inside an ESXi 6 VM to an LVM device atop
an md RAID1 device composed of two SATA SSDs passed up as a raw disk
mappings through a PVSCSI controller, this BUG followed by an Oops was
hit:

[ 86.902888] ------------[ cut here ]------------
[ 86.904600] kernel BUG at arch/x86/kernel/pci-nommu.c:66!
[ 86.906538] invalid opcode: 0000 [#1] SMP
[ 86.907991] Modules linked in: vmw_vsock_vmci_transport vsock
sb_edac edac_core intel_powerclamp coretemp crct10dif_pclmul raid1
crc32_pclmul ppdev ghash_clmulni_intel vmw_balloon joydev
intel_rapl_perf vmxnet3 acpi_cpufreq tpm_tis fjes parport_pc tpm
vmw_vmci parport shpchp i2c_piix4 dm_multipath vmwgfx drm_kms_helper
ttm drm crc32c_intel serio_raw ata_generic vmw_pvscsi pata_acpi
[ 86.914919] CPU: 0 PID: 214 Comm: kworker/0:1H Not tainted
4.7.5-200.fc24.x86_64 #1
[ 86.916123] Hardware name: VMware, Inc. VMware Virtual
Platform/440BX Desktop Reference Platform, BIOS 6.00 09/30/2014
[ 86.917720] Workqueue: kblockd blk_delay_work
[ 86.918395] task: ffff88003a65bd00 ti: ffff88003fb18000 task.ti:
ffff88003fb18000
[ 86.919478] RIP: 0010:[<ffffffffb402ecb1>] [<ffffffffb402ecb1>]
nommu_map_sg+0x91/0xc0
[ 86.920697] RSP: 0018:ffff88003fb1bc70 EFLAGS: 00010046
[ 86.921471] RAX: 0000000000000200 RBX: 0000000000000001 RCX: 0000000000000001
[ 86.922539] RDX: 0000000000000000 RSI: ffff88003f8ca600 RDI: ffff88003ce820a0
[ 86.923611] RBP: ffff88003fb1bc98 R08: 0000000000000000 R09: 0000000000000000
[ 86.924692] R10: ffff88003f053000 R11: ffff88003c38c900 R12: 0000000000000001
[ 86.925733] R13: ffff88003ce820a0 R14: 0000000000000001 R15: ffff88003f8ca600
[ 86.926817] FS: 0000000000000000(0000) GS:ffff88003ec00000(0000)
knlGS:0000000000000000
[ 86.928084] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 86.928958] CR2: 00007fc762951dd0 CR3: 000000003b6f8000 CR4: 00000000001406f0
[ 86.930034] Stack:
[ 86.930334] 0000000000000001 ffff88003ce820a0 ffffffffb4c1b1c0
0000000000000001
[ 86.931541] 0000000000000001 ffff88003fb1bcd8 ffffffffb4565e87
ffff88003f8ca600
[ 86.932762] ffff88003f075f80 ffff88003c38c900 ffff88003f944000
ffff88003f082c90
[ 86.933990] Call Trace:
[ 86.934361] [<ffffffffb4565e87>] scsi_dma_map+0x97/0xc0
[ 86.935122] [<ffffffffc00b23e5>] pvscsi_queue+0x4a5/0x860 [vmw_pvscsi]
[ 86.936129] [<ffffffffb4564280>] ? scsi_test_unit_ready+0x150/0x150
[ 86.937099] [<ffffffffb4561bbd>] scsi_dispatch_cmd+0xdd/0x220
[ 86.937936] [<ffffffffb4564ab1>] scsi_request_fn+0x461/0x5f0
[ 86.938811] [<ffffffffb402574a>] ? __switch_to+0x29a/0x4a0
[ 86.939705] [<ffffffffb43a79e3>] __blk_run_queue+0x33/0x40
[ 86.940504] [<ffffffffb43a97b5>] blk_delay_work+0x25/0x40
[ 86.941308] [<ffffffffb40ba3a4>] process_one_work+0x184/0x440
[ 86.942246] [<ffffffffb40ba6ae>] worker_thread+0x4e/0x480
[ 86.943054] [<ffffffffb40ba660>] ? process_one_work+0x440/0x440
[ 86.944033] [<ffffffffb40ba660>] ? process_one_work+0x440/0x440
[ 86.944961] [<ffffffffb40c0588>] kthread+0xd8/0xf0
[ 86.945699] [<ffffffffb47ec77f>] ret_from_fork+0x1f/0x40
[ 86.946507] [<ffffffffb40c04b0>] ? kthread_worker_fn+0x180/0x180
[ 86.947479] Code: ff ff ff 85 c0 74 3c 41 8b 47 0c 4c 89 ff 83 c3
01 41 89 47 18 e8 10 d1 3b 00 41 39 dc 49 89 c7 74 1e 49 8b 17 48 83
e2 fc 75 af <0f> 0b be 3f 00 00 00 48 c7 c7 59 51 a2 b4 e8 5c 1f 07 00
eb 80
[ 86.951837] RIP [<ffffffffb402ecb1>] nommu_map_sg+0x91/0xc0
[ 86.952728] RSP <ffff88003fb1bc70>
[ 86.953238] ---[ end trace 9ce6a81b32bb6ab3 ]---
[ 86.954013] BUG: unable to handle kernel paging request at ffffffffffffffd8
[ 86.955145] IP: [<ffffffffb40c0c60>] kthread_data+0x10/0x20
[ 86.956059] PGD 34c09067 PUD 34c0b067 PMD 0
[ 86.956776] Oops: 0000 [#2] SMP
[ 86.957245] Modules linked in: vmw_vsock_vmci_transport vsock
sb_edac edac_core intel_powerclamp coretemp crct10dif_pclmul raid1
crc32_pclmul ppdev ghash_clmulni_intel vmw_balloon joydev
intel_rapl_perf vmxnet3 acpi_cpufreq tpm_tis fjes parport_pc tpm
vmw_vmci parport shpchp i2c_piix4 dm_multipath vmwgfx drm_kms_helper
ttm drm crc32c_intel serio_raw ata_generic vmw_pvscsi pata_acpi
[ 86.962934] CPU: 0 PID: 214 Comm: kworker/0:1H Tainted: G D
4.7.5-200.fc24.x86_64 #1
[ 86.964251] Hardware name: VMware, Inc. VMware Virtual
Platform/440BX Desktop Reference Platform, BIOS 6.00 09/30/2014
[ 86.965871] task: ffff88003a65bd00 ti: ffff88003fb18000 task.ti:
ffff88003fb18000
[ 86.966969] RIP: 0010:[<ffffffffb40c0c60>] [<ffffffffb40c0c60>]
kthread_data+0x10/0x20
[ 86.968221] RSP: 0018:ffff88003fb1b940 EFLAGS: 00010002
[ 86.968978] RAX: 0000000000000000 RBX: ffff88003ec18100 RCX: 0000000000000000
[ 86.970043] RDX: ffff88003e803090 RSI: ffff88003a65bd80 RDI: ffff88003a65bd00
[ 86.971059] RBP: ffff88003fb1b940 R08: ffff88003a65bda8 R09: 0000000000000000
[ 86.972105] R10: 0000000000000000 R11: 000000000015eb90 R12: ffff88003a65c350
[ 86.973160] R13: ffff88003ec18100 R14: ffff88003a65bd00 R15: 0000000000018100
[ 86.974262] FS: 0000000000000000(0000) GS:ffff88003ec00000(0000)
knlGS:0000000000000000
[ 86.975480] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 86.976352] CR2: 0000000000000028 CR3: 000000003b6f8000 CR4: 00000000001406f0
[ 86.977517] Stack:
[ 86.977843] ffff88003fb1b950 ffffffffb40bb23e ffff88003fb1b9a8
ffffffffb47e802f
[ 86.979065] 00ff88003fb1b9c0 ffff88003a65bd00 ffff88003a65c238
0000000000000000
[ 86.980295] ffff88003fb1c000 0000000000000000 ffff88003fb1ba00
ffff88003fb1b4a0
[ 86.981525] Call Trace:
[ 86.981938] [<ffffffffb40bb23e>] wq_worker_sleeping+0xe/0x90
[ 86.982843] [<ffffffffb47e802f>] __schedule+0x50f/0x780
[ 86.983672] [<ffffffffb47e82d5>] schedule+0x35/0x80
[ 86.984465] [<ffffffffb40a4d43>] do_exit+0x7c3/0xb50
[ 86.985193] [<ffffffffb40297dc>] oops_end+0x9c/0xd0
[ 86.985974] [<ffffffffb4029c9b>] die+0x4b/0x70
[ 86.986684] [<ffffffffb4026bb2>] do_trap+0xb2/0x140
[ 86.987444] [<ffffffffb4026f99>] do_error_trap+0x89/0x110
[ 86.988279] [<ffffffffb402ecb1>] ? nommu_map_sg+0x91/0xc0
[ 86.989098] [<ffffffffb43ebf1a>] ? sg_init_table+0x1a/0x40
[ 86.989904] [<ffffffffb40274f0>] do_invalid_op+0x20/0x30
[ 86.990757] [<ffffffffb47ee13e>] invalid_op+0x1e/0x30
[ 86.991574] [<ffffffffb402ecb1>] ? nommu_map_sg+0x91/0xc0
[ 86.992410] [<ffffffffb4565e87>] scsi_dma_map+0x97/0xc0
[ 86.993241] [<ffffffffc00b23e5>] pvscsi_queue+0x4a5/0x860 [vmw_pvscsi]
[ 86.994239] [<ffffffffb4564280>] ? scsi_test_unit_ready+0x150/0x150
[ 86.995184] [<ffffffffb4561bbd>] scsi_dispatch_cmd+0xdd/0x220
[ 86.996109] [<ffffffffb4564ab1>] scsi_request_fn+0x461/0x5f0
[ 86.996943] [<ffffffffb402574a>] ? __switch_to+0x29a/0x4a0
[ 86.997807] [<ffffffffb43a79e3>] __blk_run_queue+0x33/0x40
[ 86.998665] [<ffffffffb43a97b5>] blk_delay_work+0x25/0x40
[ 86.999504] [<ffffffffb40ba3a4>] process_one_work+0x184/0x440
[ 87.000365] [<ffffffffb40ba6ae>] worker_thread+0x4e/0x480
[ 87.001150] [<ffffffffb40ba660>] ? process_one_work+0x440/0x440
[ 87.002088] [<ffffffffb40ba660>] ? process_one_work+0x440/0x440
[ 87.003017] [<ffffffffb40c0588>] kthread+0xd8/0xf0
[ 87.003800] [<ffffffffb47ec77f>] ret_from_fork+0x1f/0x40
[ 87.004576] [<ffffffffb40c04b0>] ? kthread_worker_fn+0x180/0x180
[ 87.005463] Code: f7 89 72 00 e9 53 ff ff ff e8 dd fb fd ff 0f 1f
00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 8b 87 d8 05 00 00
55 48 89 e5 <48> 8b 40 d8 5d c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44
00 00
[ 87.009721] RIP [<ffffffffb40c0c60>] kthread_data+0x10/0x20
[ 87.010615] RSP <ffff88003fb1b940>
[ 87.011170] CR2: ffffffffffffffd8
[ 87.011732] ---[ end trace 9ce6a81b32bb6ab4 ]---
[ 87.012411] Fixing recursive fault but reboot is needed!

Once the above happens the VM freezes up and needs to be hard reset.
The kernel is 4.7.5-200.fc24.x86_64 from Fedora 24.

A slightly related issue where just a "BUG at block/bio.c:1785" is hit
can be seen over on
https://www.mail-archive.com/linux-kernel@xxxxxxxxxxxxxxx/msg1243446.html
.

--
Sitsofe | http://sucs.org/~sits/