iSCSI session logout regression after fbce4d97fd ("scsi: fixup kernel warning during rmmod()")

[Max Ivanov]

Hi,

on my system I can't logout from iSCSI session when on 4.4.18, but
4.3.19 works just fine. git bisect points to  fbce4d97fd ("scsi: fixup
kernel warning during rmmod()")

Bug manifests itself like following:
  - iSCSI session logout hangs and never completes
  - 1 kworker per iSCSI session start consuming 100% CPU
  - very shortly one of 2 errors show up in dmesg (full listings are below):
      * kernel: list_del corruption, ffff88c1cd6bb810->next is LIST_POISON1
      * kernel BUG at mm/slub.c:295!

Ways to trigger bug:
  1. initiate iSCSI sessions to multiple portals
  2. let multipathd to create multipath devices
  3. run 'iscsiadm -m node --logoutall=all'

Bugs is NOT triggered and iSCSI logout succeeds when either:
  - multipathd is masked and never started
  - I manually delete all scsi devices via /sys/block/$d/device/delete
before attempting
    to do iSCSI logout

list_del_corrpution:

Feb 16 10:37:11 localhost.localdomain kernel: alua: device handler registered
Feb 16 10:37:11 localhost.localdomain kernel: emc: device handler registered
Feb 16 10:37:11 localhost.localdomain kernel: rdac: device handler registered
Feb 16 10:37:11 localhost.localdomain kernel: device-mapper: multipath
service-time: version 0.3.0 loaded
Feb 16 10:38:38 localhost.localdomain kernel: list_del corruption,
ffff88c1cd6bb810->next is LIST_POISON1 (dead000000000100)
Feb 16 10:38:38 localhost.localdomain kernel: ------------[ cut here
]------------
Feb 16 10:38:38 localhost.localdomain kernel: kernel BUG at lib/list_debug.c:47!
Feb 16 10:38:38 localhost.localdomain kernel: invalid opcode: 0000 [#1] SMP PTI
Feb 16 10:38:38 localhost.localdomain kernel: Modules linked in:
dm_service_time dm_multipath scsi_dh_rdac scsi_dh_emc scsi_dh_alua
binfmt_misc iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi
ip6t_rpfilter ip6t_REJECT nf_reject_ipv6 xt_conntrack ip_set nfnetlink
ebtable_nat ebtable_broute bridge stp llc ip6tabl
Feb 16 10:38:38 localhost.localdomain kernel:  pata_acpi
Feb 16 10:38:38 localhost.localdomain kernel: CPU: 2 PID: 5 Comm:
kworker/u24:0 Not tainted 4.14.18-300.fc27.x86_64 #1
Feb 16 10:38:38 localhost.localdomain kernel: Hardware name: VMware,
Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS
6.00 09/21/2015
Feb 16 10:38:38 localhost.localdomain kernel: Workqueue: scsi_wq_5
__iscsi_unbind_session [scsi_transport_iscsi]
Feb 16 10:38:38 localhost.localdomain kernel: task: ffff88bdede83e80
task.stack: ffffb15043158000
Feb 16 10:38:38 localhost.localdomain kernel: RIP:
0010:__list_del_entry_valid+0x4e/0x90
Feb 16 10:38:38 localhost.localdomain kernel: RSP:
0018:ffffb1504315bd88 EFLAGS: 00010082
Feb 16 10:38:38 localhost.localdomain kernel: RAX: 000000000000004e
RBX: ffff88c1cd6bbf38 RCX: 0000000000000000
Feb 16 10:38:38 localhost.localdomain kernel: RDX: 0000000000000000
RSI: ffff88bdefc96a38 RDI: ffff88bdefc96a38
Feb 16 10:38:38 localhost.localdomain kernel: RBP: 0000000000000246
R08: 00000000000007be R09: 0000000000aaaaaa
Feb 16 10:38:38 localhost.localdomain kernel: R10: ffffb1504315bd58
R11: 00000000ffffffff R12: ffff88c1ebb659c0
Feb 16 10:38:38 localhost.localdomain kernel: R13: ffff88bdec827010
R14: ffff88c1cd6bb800 R15: ffff88c1cd6bb800
Feb 16 10:38:38 localhost.localdomain kernel: FS:
0000000000000000(0000) GS:ffff88bdefc80000(0000)
knlGS:0000000000000000
Feb 16 10:38:38 localhost.localdomain kernel: CS:  0010 DS: 0000 ES:
0000 CR0: 0000000080050033
Feb 16 10:38:38 localhost.localdomain kernel: CR2: 0000563d0c1ed280
CR3: 000000057120a001 CR4: 00000000001606e0
Feb 16 10:38:38 localhost.localdomain kernel: Call Trace:
Feb 16 10:38:38 localhost.localdomain kernel:
scsi_device_dev_release_usercontext+0x52/0x250
Feb 16 10:38:38 localhost.localdomain kernel:  ? __schedule+0x10f/0x880
Feb 16 10:38:38 localhost.localdomain kernel:
execute_in_process_context+0x21/0x60
Feb 16 10:38:38 localhost.localdomain kernel:  device_release+0x30/0x80
Feb 16 10:38:38 localhost.localdomain kernel:  kobject_put+0x80/0x1a0
Feb 16 10:38:38 localhost.localdomain kernel:  scsi_remove_target+0x16d/0x1b0
Feb 16 10:38:38 localhost.localdomain kernel:
__iscsi_unbind_session+0xad/0x150 [scsi_transport_iscsi]
Feb 16 10:38:38 localhost.localdomain kernel:  process_one_work+0x184/0x3a0
Feb 16 10:38:38 localhost.localdomain kernel:  worker_thread+0x2e/0x380
Feb 16 10:38:38 localhost.localdomain kernel:  ? process_one_work+0x3a0/0x3a0
Feb 16 10:38:38 localhost.localdomain kernel:  kthread+0x11a/0x130
Feb 16 10:38:38 localhost.localdomain kernel:  ? kthread_park+0x60/0x60
Feb 16 10:38:38 localhost.localdomain kernel:  ret_from_fork+0x35/0x40
Feb 16 10:38:38 localhost.localdomain kernel: Code: 74 2b 48 8b 32 48
39 fe 75 34 48 8b 50 08 48 39 f2 75 3f b8 01 00 00 00 c3 48 89 fe 48
89 c2 48 c7 c7 90 c6 0c bf e8 0d 94 cc ff <0f> 0b 48 89 fe 48 c7 c7 c8
c6 0c bf e8 fc 93 cc ff 0f 0b 48 89
Feb 16 10:38:38 localhost.localdomain kernel: RIP:
__list_del_entry_valid+0x4e/0x90 RSP: ffffb1504315bd88
Feb 16 10:38:38 localhost.localdomain kernel: ---[ end trace
20bb15aa6c0307f2 ]---
Feb 16 10:38:38 localhost.localdomain kernel: device-mapper:
multipath: Failing path 65:0.
Feb 16 10:38:39 localhost.localdomain kernel: print_req_error: I/O
error, dev dm-2, sector 2097024
Feb 16 10:38:39 localhost.localdomain kernel: print_req_error: I/O
error, dev dm-2, sector 2097024
Feb 16 10:38:39 localhost.localdomain kernel: Buffer I/O error on dev
dm-2, logical block 262128, async page read
Feb 16 10:38:39 localhost.localdomain kernel: device-mapper:
multipath: Failing path 65:64.
Feb 16 10:38:40 localhost.localdomain kernel: device-mapper:
multipath: Failing path 65:112.
Feb 16 10:38:41 localhost.localdomain kernel: device-mapper:
multipath: Failing path 65:208.
Feb 16 10:38:42 localhost.localdomain kernel: device-mapper:
multipath: Failing path 8:112.
Feb 16 10:38:43 localhost.localdomain kernel: device-mapper:
multipath: Failing path 8:208.
Feb 16 10:38:43 localhost.localdomain kernel: device-mapper:
multipath: Failing path 8:208.
Feb 16 10:38:43 localhost.localdomain kernel: list_del corruption,
ffff88c1ebc26010->next is LIST_POISON1 (dead000000000100)


kernel BUG at mm/slub.c:

[   70.433229] scsi 3:0:0:0: alua: Detached
[   70.433233] ------------[ cut here ]------------
[   70.433234] kernel BUG at mm/slub.c:295!
[   70.433253] invalid opcode: 0000 [#1] SMP PTI
[   70.433265] Modules linked in: ip6t_rpfilter ip6t_REJECT
nf_reject_ipv6 xt_conntrack ip_set nfnetlink ebtable_nat
ebtable_broute bridge stp llc ip6table_nat nf_conntrack_ipv6
nf_defrag_ipv6 nf_nat_ipv6 ip6table_mangle ip6table_raw
ip6table_security iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4
nf_nat_ipv4 nf_nat nf_conntrack iptable_mangle iptable_raw
iptable_security dm_service_time ebtable_filter ebtables
ip6table_filter ip6_tables vmw_vsock_vmci_transport vsock sunrpc
sb_edac crct10dif_pclmul crc32_pclmul vmw_balloon ghash_clmulni_intel
intel_rapl_perf joydev i2c_piix4 vmw_vmci shpchp dm_multipath
scsi_dh_rdac scsi_dh_emc scsi_dh_alua iscsi_tcp libiscsi_tcp libiscsi
scsi_transport_iscsi xfs libcrc32c vmwgfx drm_kms_helper ttm drm
crc32c_intel ata_generic serio_raw vmxnet3 vmw_pvscsi pata_acpi
[   70.433441] CPU: 10 PID: 776 Comm: multipathd Not tainted
4.14.18-300.fc27.x86_64 #1
[   70.433458] Hardware name: VMware, Inc. VMware Virtual
Platform/440BX Desktop Reference Platform, BIOS 6.00 09/21/2015
[   70.433483] task: ffff99ab2b5ebe80 task.stack: ffffb07f83a64000
[   70.433500] RIP: 0010:__slab_free+0x18b/0x300
[   70.433511] RSP: 0018:ffffb07f83a67cb0 EFLAGS: 00010246
[   70.433525] RAX: ffff99ab2b11ff00 RBX: ffff99ab2b11ff00 RCX: 00000001802a0022
[   70.433542] RDX: ffff99ab2b11ff00 RSI: fffff31490ac47c0 RDI: ffff99ab2f803680
[   70.433558] RBP: ffffb07f83a67d50 R08: 0000000000000001 R09: ffffffff815cccbe
[   70.433574] R10: fffff31490ac47c0 R11: 0000000000000000 R12: ffff99ab2f803680
[   70.433591] R13: fffff31490ac47c0 R14: ffff99ab2b11ff00 R15: ffff99ab2d742fb0
[   70.433607] FS:  00007f6d65a7a700(0000) GS:ffff99af3fd00000(0000)
knlGS:0000000000000000
[   70.433626] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   70.433640] CR2: 00007f4a983c67f8 CR3: 000000082a726001 CR4: 00000000001606e0
[   70.433688] Call Trace:
[   70.433701]  ? __wake_up_common_lock+0x89/0xc0
[   70.433715]  ? __slab_free+0x15b/0x300
[   70.433726]  ? scsi_dh_release_device+0x1e/0x60
[   70.433738]  scsi_dh_release_device+0x1e/0x60
[   70.433750]  scsi_device_dev_release_usercontext+0x2a/0x250
[   70.434206]  execute_in_process_context+0x21/0x60
[   70.434643]  device_release+0x30/0x80
[   70.435098]  kobject_put+0x80/0x1a0
[   70.435525]  scsi_disk_put+0x2b/0x40
[   70.435942]  __blkdev_put+0x197/0x1f0
[   70.436355]  blkdev_close+0x21/0x30
[   70.436756]  __fput+0xd0/0x1e0
[   70.437152]  task_work_run+0x84/0xa0
[   70.437539]  exit_to_usermode_loop+0x9e/0xa0
[   70.437917]  do_syscall_64+0x173/0x180
[   70.438133] device-mapper: multipath: Failing path 65:16.
[   70.438140] device-mapper: multipath: Failing path 65:0.
[   70.438985]  entry_SYSCALL_64_after_hwframe+0x21/0x86
[   70.439325] RIP: 0033:0x7f6d64a3a70c
[   70.439648] RSP: 002b:00007f6d65a78880 EFLAGS: 00000293 ORIG_RAX:
0000000000000003
[   70.439974] RAX: 0000000000000000 RBX: 00007f6d4c0306f0 RCX: 00007f6d64a3a70c
[   70.440293] RDX: 0000000000000000 RSI: 0000000000000001 RDI: 000000000000000a
[   70.440605] RBP: 00007f6d4c030a68 R08: 0000000000000054 R09: 0000000000000080
[   70.440907] R10: 00000000ffffffdf R11: 0000000000000293 R12: 000055867dd47410
[   70.441199] R13: 0000000000000000 R14: 0000000000000001 R15: 00007f6d4c03be00
[   70.441486] Code: fe ff ff 44 0f b6 bd 7f ff ff ff 80 7d ab 00 79
05 45 84 ff 74 7b 48 83 c4 78 5b 41 5c 41 5d 41 5e 41 5f 5d 49 8d 65
f0 41 5d c3 <0f> 0b 4c 89 d0 4c 89 55 88 45 89 fa 48 85 c0 44 0f b6 bd
7f ff
[   70.442406] RIP: __slab_free+0x18b/0x300 RSP: ffffb07f83a67cb0
[   70.442735] ---[ end trace c79c468d1b715f7e ]---
[   70.540044] device-mapper: multipath: Failing path 8:32.