Comment 4 for bug 1837788

For reference, this is the Warning in the CurrentDmesg.txt file.

[ 71.925684] WARNING: CPU: 8 PID: 2977 at /build/linux-jmOa1Y/linux-4.15.0/drivers/md/bcache/writeback.c:603 bch_cached_dev_writeback_start+0x13f/0x1af [bcache]
[ 71.925686] Modules linked in: ebtable_filter ebtables ip6table_filter ip6_tables devlink iptable_filter nls_utf8 cifs ccm fscache bridge stp llc bonding nls_iso8859_1 intel_rapl sb_edac x86_pkg_temp_thermal intel_powerclamp kvm_intel kvm irqbypass ttm drm_kms_helper crct10dif_pclmul crc32_pclmul ghash_clmulni_intel pcbc drm fb_sys_fops syscopyarea sysfillrect sysimgblt aesni_intel mxm_wmi aes_x86_64 crypto_simd glue_helper uvcvideo cryptd snd_hda_codec_realtek snd_hda_codec_generic snd_hda_codec_hdmi snd_hda_intel snd_hda_codec videobuf2_vmalloc videobuf2_memops videobuf2_v4l2 videobuf2_core snd_hda_core videodev media intel_cstate snd_hwdep snd_pcm snd_timer snd intel_rapl_perf input_leds soundcore shpchp serio_raw ioatdma mei_me lpc_ich mei mac_hid wmi sch_fq_codel vhost_net vhost tap coretemp
[ 71.925727] lp parport ip_tables x_tables autofs4 raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c raid0 multipath linear bcache raid1 hid_generic usbhid hid igb i2c_algo_bit dca firewire_ohci isci ahci ptp firewire_core libahci crc_itu_t libsas pps_core nvme scsi_transport_sas nvme_core
[ 71.925751] CPU: 8 PID: 2977 Comm: bash Not tainted 4.15.0-54-generic #58-Ubuntu
[ 71.925752] Hardware name: Supermicro X9DAi/X9DAi, BIOS 3.2 05/09/2015
[ 71.925759] RIP: 0010:bch_cached_dev_writeback_start+0x13f/0x1af [bcache]
[ 71.925760] RSP: 0018:ffffa784c96abd08 EFLAGS: 00010287
[ 71.925761] RAX: ffff967af8bfdb00 RBX: ffff967af3660000 RCX: 0000000000000000
[ 71.925762] RDX: 0000000000000000 RSI: ffff967aff2a70a0 RDI: ffff966aff407780
[ 71.925763] RBP: ffffa784c96abd10 R08: 00000000000270a0 R09: ffffffffaecaf22d
[ 71.925764] R10: 0000000000000000 R11: 000000000000024b R12: ffff967af3660010
[ 71.925765] R13: ffff967af3660000 R14: ffff967af4320000 R15: ffff967af3660ac8
[ 71.925767] FS: 00007f7759f51740(0000) GS:ffff967aff280000(0000) knlGS:0000000000000000
[ 71.925768] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 71.925770] CR2: 00007fff24052e08 CR3: 0000001ff4410001 CR4: 00000000000626e0
[ 71.925771] Call Trace:
[ 71.925781] bch_cached_dev_attach+0x34b/0x510 [bcache]
[ 71.925787] ? kernfs_fop_write+0xcb/0x1a0
[ 71.925793] __cached_dev_store+0x5c1/0x6d0 [bcache]
[ 71.925798] ? __cached_dev_store+0x5c1/0x6d0 [bcache]
[ 71.925804] bch_cached_dev_store+0x39/0xc0 [bcache]
[ 71.925806] sysfs_kf_write+0x3c/0x50
[ 71.925808] kernfs_fop_write+0x125/0x1a0
[ 71.925811] __vfs_write+0x1b/0x40
[ 71.925813] vfs_write+0xb1/0x1a0
[ 71.925814] SyS_write+0x55/0xc0
[ 71.925819] do_syscall_64+0x73/0x130
[ 71.925825] entry_SYSCALL_64_after_hwframe+0x3d/0xa2
[ 71.925826] RIP: 0033:0x7f775962b154
[ 71.925827] RSP: 002b:00007fff76f6a788 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
[ 71.925829] RAX: ffffffffffffffda RBX: 0000000000000025 RCX: 00007f775962b154
[ 71.925830] RDX: 0000000000000025 RSI: 000055c6907e0140 RDI: 0000000000000001
[ 71.925831] RBP: 000055c6907e0140 R08: 000000000000000a R09: 0000000000000024
[ 71.925832] R10: 000000000000000a R11: 0000000000000246 R12: 00007f7759907760
[ 71.925833] R13: 0000000000000025 R14: 00007f77599032a0 R15: 00007f7759902760
[ 71.925834] Code: 0a 00 00 0f 88 84 00 00 00 75 18 48 8b 35 c2 13 e2 ef 48 8d 93 a0 0a 00 00 bf 00 20 00 00 e8 f9 a6 86 ee 8b 83 80 0b 00 00 eb a1 <0f> 0b e9 5c ff ff ff b8 f4 ff ff ff eb 93 49 8d 8c 24 88 0a 00
[ 71.925865] ---[ end trace b657ee904e9a8497 ]---
[ 71.925880] bcache: bch_cached_dev_attach() Caching md1 as bcache0 on set eb92c552-bd01-458a-994e-7f8760fd6342