Hello Jens and Christoph, With Jens' for-next branch (commit fe02d46ab775), if I run the following commands: modprobe scsi_debug delay=0 dif=3 dix=-1 dev_size_mb=16 mkfs.xfs /dev/disk/by-id/scsi-1Linux_scsi_debug_22000 then the output shown below appears in the kernel log. Does anyone know how to fix this? Sorry but I'm not really familiar with the integrity code. Thanks, Bart. [ 170.657016] scsi 10:0:0:0: Direct-Access Linux scsi_debug 0186 PQ: 0 ANSI: 7 [ 170.839518] sd 10:0:0:0: [sdc] Enabling DIF Type 3 protection [ 170.839918] sd 10:0:0:0: [sdc] 32768 512-byte logical blocks: (16.8 MB/16.0 MiB) [ 170.840061] sd 10:0:0:0: [sdc] Write Protect is off [ 170.840153] sd 10:0:0:0: [sdc] Mode Sense: 73 00 10 08 [ 170.840317] sd 10:0:0:0: [sdc] Write cache: enabled, read cache: enabled, supports DPO and FUA [ 170.841439] sd 10:0:0:0: Attached scsi generic sg3 type 0 [ 170.847081] sd 10:0:0:0: [sdc] Enabling DIX T10-DIF-TYPE3-CRC protection [ 170.847157] sd 10:0:0:0: [sdc] DIF application tag size 6 [ 170.847723] sd 10:0:0:0: [sdc] Attached SCSI disk [ 173.404195] general protection fault: 0000 [#1] SMP [ 173.404252] Modules linked in: scsi_debug netconsole xt_CHECKSUM iptable_mangle ipt_MASQUERADE nf_nat_masquerade_ipv4 iptable_nat nf_nat_ipv4 nf_nat nf_conntrack_ipv4 nf_defrag_ipv4 xt_conntrack nf_conntrack libcrc32c ipt_REJECT nf_reject_ipv4 xt_tcpudp tun bridge stp llc ebtable_filter ebtables ip6table_filter ip6_tables iptable_filter ip_tables x_tables ib_srp scsi_transport_srp ib_ipoib rdma_ucm ib_ucm ib_uverbs ib_umad rdma_cm configfs ib_cm iw_cm mlx4_ib af_packet sb_edac x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel kvm ib_core irqbypass crct10dif_pclmul crc32_pclmul iTCO_wdt crc32c_intel iTCO_vendor_support ghash_clmulni_intel ipmi_ssif pcbc aesni_intel aes_x86_64 dcdbas tg3 crypto_simd mlx4_core glue_helper ptp cryptd pcspkr pps_core libphy devlink ipmi_si ipmi_devintf ipmi_msghandler [ 173.404556] mei_me tpm_tis lpc_ich mei tpm_tis_core ioatdma mfd_core shpchp tpm acpi_pad button dca wmi hid_generic usbhid mgag200 i2c_algo_bit ehci_pci drm_kms_helper syscopyarea ehci_hcd sysfillrect sysimgblt fb_sys_fops ttm drm sr_mod cdrom xhci_pci xhci_hcd usbcore usb_common sg dm_multipath dm_mod scsi_dh_rdac scsi_dh_emc scsi_dh_alua autofs4 [last unloaded: scsi_debug] [ 173.404725] CPU: 1 PID: 8379 Comm: mkfs.xfs Tainted: G I 4.12.0-rc3-dbg+ #2 [ 173.404776] Hardware name: Dell Inc. PowerEdge R430/03XKDV, BIOS 1.0.2 11/17/2014 [ 173.404818] task: ffff8804462cb140 task.stack: ffffc90003944000 [ 173.404862] RIP: 0010:kfree+0x6a/0x280 [ 173.404904] RSP: 0018:ffffc90003947de8 EFLAGS: 00010207 [ 173.404953] RAX: ffffea0000000000 RBX: dadfe2db46463b6b RCX: 0000000000000fff [ 173.405005] RDX: ffff88046ee5b3c0 RSI: 00000000ffffffff RDI: ffffffff81c51cc0 [ 173.405056] RBP: ffffc90003947e10 R08: 0000000000000000 R09: 0000000000000001 [ 173.405109] R10: 0000000000000000 R11: 0000000000000000 R12: ffff88017be24dc0 [ 173.405163] R13: 036b6b6b6d1918c0 R14: 00007ffeac297300 R15: 00007ffeac297330 [ 173.405217] FS: 00007ff6d4c42100(0000) GS:ffff88046ee40000(0000) knlGS:0000000000000000 [ 173.405448] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 173.405498] CR2: 00000000016e2118 CR3: 00000003fcdce000 CR4: 00000000001406e0 [ 173.405549] Call Trace: [ 173.405597] bio_integrity_free+0xa8/0xb0 [ 173.405644] __bio_free+0x22/0x30 [ 173.405682] bio_free+0x16/0x60 [ 173.405726] bio_put+0x1d/0x30 [ 173.405763] blkdev_issue_flush+0x6f/0x90 [ 173.405810] blkdev_fsync+0x30/0x40 [ 173.405849] vfs_fsync_range+0x46/0xa0 [ 173.405895] ? trace_hardirqs_on_caller+0xf9/0x190 [ 173.405944] do_fsync+0x38/0x60 [ 173.405989] SyS_fsync+0xb/0x10 [ 173.406034] entry_SYSCALL_64_fastpath+0x18/0xad [ 173.406074] RIP: 0033:0x7ff6d43f1700 [ 173.406118] RSP: 002b:00007ffeac297108 EFLAGS: 00000246 ORIG_RAX: 000000000000004a [ 173.406169] RAX: ffffffffffffffda RBX: 0000000000000046 RCX: 00007ff6d43f1700 [ 173.406218] RDX: 000000000065a680 RSI: 0000000000000000 RDI: 0000000000000004 [ 173.406259] RBP: 00007ffeac296fe4 R08: 00000000016dfa80 R09: 00000000ffffff00 [ 173.406308] R10: 000000000000009d R11: 0000000000000246 R12: 00000000016e0040 [ 173.406350] R13: 00000000016e0910 R14: 00007ffeac297070 R15: 0000000000000004 [ 173.406393] Code: 48 01 d8 0f 82 22 02 00 00 49 bd 00 00 00 80 ff 77 00 00 49 01 c5 48 b8 00 00 00 00 00 ea ff ff 49 c1 ed 0c 49 c1 e5 06 49 01 c5 <49> 8b 45 20 48 8d 50 ff a8 01 4c 0f 45 ea 49 8b 55 20 48 8d 42 [ 173.406560] RIP: kfree+0x6a/0x280 RSP: ffffc90003947de8 [ 173.406605] ---[ end trace dc862dd689d8b936 ]--- (gdb) list *(bio_integrity_free+0xa8) 0xffffffff8134fad8 is in bio_integrity_free (block/bio-integrity.c:111). 106 { 107 struct bio_integrity_payload *bip = bio_integrity(bio); 108 struct bio_set *bs = bio->bi_pool; 109 110 if (bip->bip_flags & BIP_BLOCK_INTEGRITY) 111 kfree(page_address(bip->bip_vec->bv_page) + 112 bip->bip_vec->bv_offset); 113 114 if (bs && bs->bio_integrity_pool) { 115 bvec_free(bs->bvec_integrity_pool, bip->bip_vec, bip->bip_slab);