Hi, I every few weeks or so I am seeing the below kernel bug trace. The root fielsystem starts to block on all IO operations afterwards. This is currently on 5.4.24. I am not aware of any special load that might be triggering this issue. The root filesystem is a RAID1 across two dm-crypt volumes. Once upon a time I had compression enabled on the filesystem but disabled that some (>6) months ago. The error occured long before that and I thought by disabling compression and did run defrag after disabling it. That doesn't seem to have changed anything. I also had this bug happen back on 4.19.75 (and potentially older; don't have all the logs anymore). Is this known or even fixed on some newer kernel? What else can I provide to solve this? I am happy to test patches, different kernel versions, …. Regards, andi > BUG: kernel NULL pointer dereference, address: 0000000000000000 > #PF: supervisor read access in kernel mode > #PF: error_code(0x0000) - not-present page > PGD 1f5976067 P4D 1f5976067 PUD 1b1a95067 PMD 0 > Oops: 0000 [#1] SMP NOPTI > CPU: 5 PID: 12681 Comm: kworker/u24:12 Tainted: P O 5.4.24 #1-NixOS > Hardware name: Supermicro Super Server/A2SDi-12C-HLN4F, BIOS 1.1b 12/17/2018 > Workqueue: btrfs-delalloc btrfs_work_helper [btrfs] > RIP: 0010:compress_file_range+0x6f4/0x7a0 [btrfs] > Code: 00 00 31 db 41 83 e1 20 41 83 c9 0f e8 05 ac 01 00 31 c0 48 83 7c 24 40 00 75 0f eb 33 83 c3 01 48 63 c3 48 3b 44 24 40 73 26 <49> 8b 3c c6 48 83 7f 18 00 75 2b 48 8b 47 08 48 8d 50 ff a8 01 48 > RSP: 0018:ffffb8c307267da0 EFLAGS: 00010202 > RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffe91c95f29ac7 > RDX: 0000000000000000 RSI: 000000000000001e RDI: ffffe91ca155bd00 > RBP: 0000000000000410 R08: ffff9fdfbfffc002 R09: ffff9fdfbfffc000 > R10: 000000000002e520 R11: ffffffffffffffb8 R12: 0000000000001000 > R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 > FS: 0000000000000000(0000) GS:ffff9fdf9f940000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 0000000000000000 CR3: 0000000152a42000 CR4: 00000000003406e0 > Call Trace: > ? submit_compressed_extents+0x440/0x440 [btrfs] > async_cow_start+0x12/0x30 [btrfs] > btrfs_work_helper+0xbe/0x370 [btrfs] > process_one_work+0x206/0x3c0 > worker_thread+0x2d/0x3e0 > ? process_one_work+0x3c0/0x3c0 > kthread+0x112/0x130 > ? kthread_park+0x80/0x80 > ret_from_fork+0x35/0x40 > Modules linked in: tcp_diag inet_diag sctp ccm algif_aead cmac algif_hash bluetooth ecdh_generic ecc crc16 af_packet cfg80211 msr rfkill 8021q xt_comment iptable_nat nf_nat xt_conntrack nf_conntrack nf_defrag_ipv4 ip6t_rpfilter ipt_rpfilter ip6table_raw iptable_raw xt_pkttype nf_log_ipv6 nf_log_ipv4 nf_log_common xt_LOG xt_tcpudp ip6table_filter sch_fq_codel ip6_tables iptable_filter atkbd libps2 serio loop cpufreq_ondemand pnd2_edac edac_core intel_rapl_msr intel_rapl_common x86_pkg_temp_thermal intel_powerclamp ipmi_ssif ast drm_vram_helper ttm drm_kms_helper nls_iso8859_1 coretemp nls_cp437 vfat drm fat deflate ixgbe efi_pstore crct10dif_pclmul mousedev ftdi_sio crc32_pclmul evdev pstore zfs(PO) usbserial ghash_clmulni_intel wdat_wdt xfrm_algo intel_cstate mac_hid agpgart cmdlinepart libphy intel_spi_pci intel_spi intel_rapl_perf ptp spi_nor pps_core efivars i2c_algo_bit mdio watchdog mtd i2c_i801 fb_sys_fops dca syscopyarea ipmi_si sysfillrect i2c_ismt sysimgblt i2c_core > ipmi_devintf ipmi_msghandler zunicode(PO) zavl(PO) hed icp(PO) acpi_cpufreq button zlua(PO) zcommon(PO) znvpair(PO) spl(O) tun tap macvlan bridge stp llc kvm_intel kvm irqbypass efivarfs ip_tables x_tables ipv6 nf_defrag_ipv6 crc_ccitt autofs4 dm_crypt algif_skcipher af_alg input_leds led_class hid_generic usbhid hid sd_mod xhci_pci xhci_hcd ahci libahci libata usbcore aesni_intel scsi_mod nvme crypto_simd cryptd glue_helper nvme_core usb_common rtc_cmos dm_mod btrfs libcrc32c crc32c_generic crc32c_intel xor zstd_decompress zstd_compress raid6_pq > CR2: 0000000000000000 > ---[ end trace f3d14d793f393d09 ]--- > RIP: 0010:compress_file_range+0x6f4/0x7a0 [btrfs] > Code: 00 00 31 db 41 83 e1 20 41 83 c9 0f e8 05 ac 01 00 31 c0 48 83 7c 24 40 00 75 0f eb 33 83 c3 01 48 63 c3 48 3b 44 24 40 73 26 <49> 8b 3c c6 48 83 7f 18 00 75 2b 48 8b 47 08 48 8d 50 ff a8 01 48 > RSP: 0018:ffffb8c307267da0 EFLAGS: 00010202 > RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffe91c95f29ac7 > RDX: 0000000000000000 RSI: 000000000000001e RDI: ffffe91ca155bd00 > RBP: 0000000000000410 R08: ffff9fdfbfffc002 R09: ffff9fdfbfffc000 > R10: 000000000002e520 R11: ffffffffffffffb8 R12: 0000000000001000 > R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 > FS: 0000000000000000(0000) GS:ffff9fdf9f940000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 0000000000000000 CR3: 0000000152a42000 CR4: 00000000003406e0
