Package: src:linux Version: 4.19.37-5+deb10u1 Severity: important Bug is triggered after trying to cp --reflink a large file (30 GB). Process 'btrfs-transacti' gets stuck at 100% CPU with no disk activity and no visible progress (I let it run for over an hour). All processes which require disk access stall or crash, rendering the system unusable.
The bug manifests only with 'btrfs quota enable'. When quota is disabled the operation completes without error. -- Package-specific info: ** Version: Linux version 4.19.0-5-amd64 (debian-kernel@lists.debian.org) (gcc version 8.3.0 (Debian 8.3.0-6)) #1 SMP Debian 4.19.37-5+deb10u1 (2019-07-19) ** Kernel log: [ 363.718732] INFO: task kworker/u4:0:7 blocked for more than 120 seconds. [ 363.719619] Not tainted 4.19.0-5-amd64 #1 Debian 4.19.37-5+deb10u1 [ 363.720518] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 363.721430] kworker/u4:0 D 0 7 2 0x80000000 [ 363.722361] Workqueue: btrfs-endio-write btrfs_endio_write_helper [btrfs] [ 363.723307] Call Trace: [ 363.724217] ? __schedule+0x2a2/0x870 [ 363.725131] schedule+0x28/0x80 [ 363.726061] wait_current_trans+0xc3/0xf0 [btrfs] [ 363.726988] ? finish_wait+0x80/0x80 [ 363.727912] start_transaction+0x1d2/0x3f0 [btrfs] [ 363.728849] btrfs_finish_ordered_io+0x2a1/0x7c0 [btrfs] [ 363.729780] ? syscall_return_via_sysret+0x13/0x83 [ 363.730714] ? __switch_to_asm+0x40/0x70 [ 363.731637] ? __switch_to_asm+0x34/0x70 [ 363.732577] normal_work_helper+0xba/0x300 [btrfs] [ 363.733530] process_one_work+0x1a7/0x3a0 [ 363.734451] worker_thread+0x30/0x390 [ 363.735381] ? create_worker+0x1a0/0x1a0 [ 363.736293] kthread+0x112/0x130 [ 363.737203] ? kthread_bind+0x30/0x30 [ 363.738117] ret_from_fork+0x35/0x40 [ 363.739028] INFO: task kworker/u4:1:57 blocked for more than 120 seconds. [ 363.739932] Not tainted 4.19.0-5-amd64 #1 Debian 4.19.37-5+deb10u1 [ 363.740814] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 363.741677] kworker/u4:1 D 0 57 2 0x80000000 [ 363.742557] Workqueue: btrfs-endio-write btrfs_endio_write_helper [btrfs] [ 363.743423] Call Trace: [ 363.744249] ? __schedule+0x2a2/0x870 [ 363.745081] schedule+0x28/0x80 [ 363.745920] wait_current_trans+0xc3/0xf0 [btrfs] [ 363.746752] ? finish_wait+0x80/0x80 [ 363.747542] start_transaction+0x1d2/0x3f0 [btrfs] [ 363.748343] btrfs_finish_ordered_io+0x2a1/0x7c0 [btrfs] [ 363.749141] ? syscall_return_via_sysret+0x13/0x83 [ 363.749948] ? __switch_to_asm+0x40/0x70 [ 363.750757] ? __switch_to_asm+0x34/0x70 [ 363.751557] normal_work_helper+0xba/0x300 [btrfs] [ 363.752342] process_one_work+0x1a7/0x3a0 [ 363.753129] worker_thread+0x30/0x390 [ 363.753916] ? create_worker+0x1a0/0x1a0 [ 363.754710] kthread+0x112/0x130 [ 363.755495] ? kthread_bind+0x30/0x30 [ 363.756273] ret_from_fork+0x35/0x40 ** Hardware info: CPU: Intel Pentium G3250 Chipset: Intel H81 System board: Asrock H81M-DGS R2.0 RAM: 16 GB -- System Information: Debian Release: 10.0 APT prefers stable APT policy: (500, 'stable') Architecture: amd64 (x86_64) Kernel: Linux 4.19.0-5-amd64 (SMP w/2 CPU cores) Locale: LANG=en_DK.UTF-8, LC_CTYPE=en_DK.UTF-8 (charmap=UTF-8), LANGUAGE=en_DK.UTF-8 (charmap=UTF-8) Shell: /bin/sh linked to /bin/dash Init: systemd (via /run/systemd/system) LSM: AppArmor: enabled Versions of packages linux-image-4.19.0-5-amd64 depends on: ii initramfs-tools [linux-initramfs-tool] 0.133 ii kmod 26-1 ii linux-base 4.6 Versions of packages linux-image-4.19.0-5-amd64 recommends: ii apparmor 2.13.2-10 ii firmware-linux-free 3.4 Versions of packages linux-image-4.19.0-5-amd64 suggests: pn debian-kernel-handbook <none> ii grub-pc 2.02+dfsg1-20 pn linux-doc-4.19 <none> Versions of packages linux-image-4.19.0-5-amd64 is related to: ii firmware-amd-graphics 20190114-1 ii firmware-atheros 20190114-1 pn firmware-bnx2 <none> pn firmware-bnx2x <none> pn firmware-brcm80211 <none> pn firmware-cavium <none> pn firmware-intel-sound <none> pn firmware-intelwimax <none> pn firmware-ipw2x00 <none> pn firmware-ivtv <none> pn firmware-iwlwifi <none> pn firmware-libertas <none> ii firmware-linux-nonfree 20190114-1 ii firmware-misc-nonfree 20190114-1 pn firmware-myricom <none> pn firmware-netxen <none> pn firmware-qlogic <none> ii firmware-realtek 20190114-1 pn firmware-samsung <none> pn firmware-siano <none> pn firmware-ti-connectivity <none> pn xen-hypervisor <none>
