Comment 1 for bug 1902254

[224259.453356] ------------[ cut here ]------------
[224259.453360] kernel BUG at /build/linux-eTBZpZ/linux-4.15.0/fs/btrfs/ctree.c:3233!
[224259.453390] illegal operation: 0001 ilc:1 [#1] SMP
[224259.453392] Modules linked in: vhost_net xt_nat macvtap tap veth macvlan ipt_MASQUERADE nf_nat_masquerade_ipv4 nf_conntrack_netlink nfnetlink xfrm_user xfrm_algo xt_addr
type iptable_nat nf_nat_ipv4 nf_nat br_netfilter bridge vhost_vsock vmw_vsock_virtio_transport_common vhost vsock algif_skcipher af_alg xt_tcpudp xt_multiport aufs bonding 8
021q garp stp mrp llc overlay nf_conntrack_ipv6 nf_defrag_ipv6 nf_conntrack_ipv4 nf_defrag_ipv4 xt_conntrack nf_conntrack libcrc32c scsi_dh_rdac scsi_dh_emc scsi_dh_alua ip6
table_filter ip6_tables qeth_l2 s390_trng qeth chsc_sch ccwgroup vfio_ccw eadm_sch iptable_filter sch_fq_codel zFPC_proc(OE) zFPC_diag(OE) vfio_ap vfio_mdev mdev vfio_iommu_
type1 vfio ip_tables x_tables ghash_s390 prng aes_s390 des_s390 des_generic sha512_s390 sha256_s390 sha1_s390 sha_common
[224259.453415] crc32_vx_s390 btrfs xor zstd_compress raid6_pq dm_crypt virtio_blk dm_service_time dm_multipath zfcp scsi_transport_fc qdio dasd_eckd_mod dasd_mod zlib_defl
ate
[224259.453423] CPU: 6 PID: 57332 Comm: qemu-system-s39 Tainted: G OE 4.15.0-109-generic #110-Ubuntu
[224259.453423] Hardware name: IBM 3907 LR1 A00 (LPAR)
[224259.453425] Krnl PSW : 00000000be9cb874 00000000ef3786e8 (btrfs_set_item_key_safe+0x152/0x1c0 [btrfs])
[224259.453492] R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:3 CC:0 PM:0 RI:0 EA:3
[224259.453493] Krnl GPRS: 0000000000000001 00000056bdc00000 0000000000000000 0000000cbf93795d
[224259.453493] 000003ff0000006c 0000000000631468 000000136a230000 0000000cbf937826
[224259.453494] 00000007ee281d88 0000000cbf93795d 00000007000000a1 00000013188a58c0
[224259.453495] 00000012eb889701 00000056bdb00000 000003ff801780a8 0000000cbf937780
[224259.453503] Krnl Code: 000003ff801780a2: c0e5fffff857 brasl %r14,000003ff80177150
000003ff801780a8: ec22ff92007e cij %r2,0,2,000003ff80177fcc
#000003ff801780ae: a7f40001 brc 15,000003ff801780b0
>000003ff801780b2: ec2affff00d8 ahik %r2,%r10,-1
000003ff801780b8: b9140022 lgfr %r2,%r2
000003ff801780bc: eb120001000d sllg %r1,%r2,1
000003ff801780c2: b9080012 agr %r1,%r2
000003ff801780c6: eb110003000d sllg %r1,%r1,3
[224259.453514] Call Trace:
[224259.453527] ([<000003ff8017807c>] btrfs_set_item_key_safe+0x11c/0x1c0 [btrfs])
[224259.453544] [<000003ff801c3322>] __btrfs_drop_extents+0xb5a/0xda8 [btrfs]
[224259.453561] [<000003ff801f98a4>] btrfs_log_changed_extents+0x35c/0xaf0 [btrfs]
[224259.453577] [<000003ff801faa26>] btrfs_log_inode+0x9ee/0x1080 [btrfs]
[224259.453594] [<000003ff801fb384>] btrfs_log_inode_parent+0x224/0xa10 [btrfs]
[224259.453611] [<000003ff801fcea8>] btrfs_log_dentry_safe+0x80/0xa8 [btrfs]
[224259.453627] [<000003ff801c5ea2>] btrfs_sync_file+0x392/0x550 [btrfs]
[224259.453634] [<00000000003cce5e>] do_fsync+0x5e/0x90
[224259.453636] [<00000000003cd15a>] SyS_fdatasync+0x32/0x48
[224259.453640] [<00000000008fd314>] system_call+0xd8/0x2c8
[224259.453640] Last Breaking-Event-Address:
[224259.453652] [<000003ff801780ae>] btrfs_set_item_key_safe+0x14e/0x1c0 [btrfs]
[224259.453653]
[224259.453654] Kernel panic - not syncing: Fatal exception: panic_on_oops