Kernel error "task zfs:pid blocked for more than 120 seconds"

[Colin Ian King]

== SRU Justification, XENIAL, BIONIC ==

Exercising ZFS with lxd with many mount/umounts can cause lockups and 120 second timeout messages.

== How to reproduce bug ==

In a VM, 2 CPUs, 16GB of memory running Bionic:

sudo apt update
sudo apt install lxd lxd-client lxd-tools zfsutils-linux
sudo lxd init

(and with the default init options)

then run:

lxd-benchmark launch --count 96 --parallel 96

This will reliably show the lockup every time without the fix. With the fix (detailed below) one cannot reproduce the lockup.

== Fix ==

Upstream ZFS commit

commit ac09630d8b0bf6c92084a30fdaefd03fd0adbdc1
Author: Brian Behlendorf <email address hidden>
Date: Wed Jul 11 15:49:10 2018 -0700

    Fix zpl_mount() deadlock

== Regression Potential ==

This just changes the locking in the mount path of ZFS and will only affect ZFS mount/unmounts. The regression potential is small as this touches a very small code path that has been exhaustively exercises this code under multiple thread/CPU contention and shown not to break.

------------------

ZFS bug report: https://github.com/zfsonlinux/zfs/issues/7691

"I am using LXD containers that are configured to use a ZFS storage backend.
I create many containers using a benchmark tool, which probably stresses the use of ZFS.
In two out of four attempts, I got

[ 725.970508] INFO: task lxd:4455 blocked for more than 120 seconds.
[ 725.976730] Tainted: P O 4.15.0-20-generic #21-Ubuntu
[ 725.983551] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 725.991624] INFO: task txg_sync:4202 blocked for more than 120 seconds.
[ 725.998264] Tainted: P O 4.15.0-20-generic #21-Ubuntu
[ 726.005071] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 726.013313] INFO: task lxd:99919 blocked for more than 120 seconds.
[ 726.019609] Tainted: P O 4.15.0-20-generic #21-Ubuntu
[ 726.026418] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 726.034560] INFO: task zfs:100513 blocked for more than 120 seconds.
[ 726.040936] Tainted: P O 4.15.0-20-generic #21-Ubuntu
[ 726.047746] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 726.055791] INFO: task zfs:100584 blocked for more than 120 seconds.
[ 726.062170] Tainted: P O 4.15.0-20-generic #21-Ubuntu
[ 726.068979] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.

Describe how to reproduce the problem

    Start an Ubuntu 18.04 LTS server.
    Install LXD if not already installed.

sudo apt update
sudo apt install lxd lxd-client lxd-tools zfsutils-linux

    Configure LXD with sudo lxd init. When prompted for the storage backend, select ZFS and specify an empty disk.

$ sudo lxd init
Would you like to use LXD clustering? (yes/no) [default=no]:
 Do you want to configure a new storage pool? (yes/no) [default=yes]:
 Name of the new storage pool [default=default]:
 Name of the storage backend to use (dir, zfs) [default=zfs]:
 Create a new ZFS pool? (yes/no) [default=yes]:
 Would you like to use an existing block device? (yes/no) [default=no]: yes
 Path to the existing block device: /dev/sdb
 Would you like to connect to a MAAS server? (yes/no) [default=no]:
 Would you like to create a new local network bridge? (yes/no) [default=yes]: no
 Would you like to configure LXD to use an existing bridge or host interface? (yes/no) [default=no]: no
 Would you like LXD to be available over the network? (yes/no) [default=no]:
 Would you like stale cached images to be updated automatically? (yes/no) [default=yes]
 Would you like a YAML "lxd init" preseed to be printed? (yes/no) [default=no]:

    Now run the following to launch 48 containers in batches of 12.

lxd-benchmark launch --count 48 --parallel 12

In two out of four attempts, I got the kernel errors.

I also tried

echo 1 >/sys/module/spl/parameters/spl_taskq_kick

but did not manage to continue.
Include any warning/errors/backtraces from the system logs
dmesg output

[ 725.970508] INFO: task lxd:4455 blocked for more than 120 seconds.
[ 725.976730] Tainted: P O 4.15.0-20-generic #21-Ubuntu
[ 725.983551] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 725.991408] lxd D 0 4455 1 0x00000000
[ 725.991412] Call Trace:
[ 725.991424] __schedule+0x297/0x8b0
[ 725.991428] schedule+0x2c/0x80
[ 725.991429] rwsem_down_write_failed+0x162/0x360
[ 725.991460] ? dbuf_rele_and_unlock+0x1a8/0x4b0 [zfs]
[ 725.991465] call_rwsem_down_write_failed+0x17/0x30
[ 725.991468] ? call_rwsem_down_write_failed+0x17/0x30
[ 725.991469] down_write+0x2d/0x40
[ 725.991472] grab_super+0x30/0x90
[ 725.991501] ? zpl_create+0x160/0x160 [zfs]
[ 725.991504] sget_userns+0x91/0x490
[ 725.991507] ? get_anon_bdev+0x100/0x100
[ 725.991534] ? zpl_create+0x160/0x160 [zfs]
[ 725.991537] sget+0x7d/0xa0
[ 725.991540] ? get_anon_bdev+0x100/0x100
[ 725.991567] zpl_mount+0xa8/0x160 [zfs]
[ 725.991570] mount_fs+0x37/0x150
[ 725.991574] vfs_kern_mount.part.23+0x5d/0x110
[ 725.991576] do_mount+0x5ed/0xce0
[ 725.991577] ? copy_mount_options+0x2c/0x220
[ 725.991578] SyS_mount+0x98/0xe0
[ 725.991582] do_syscall_64+0x73/0x130
[ 725.991583] entry_SYSCALL_64_after_hwframe+0x3d/0xa2
[ 725.991585] RIP: 0033:0x4dbd5a
[ 725.991586] RSP: 002b:000000c428be6890 EFLAGS: 00000206 ORIG_RAX: 00000000000000a5
[ 725.991588] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00000000004dbd5a
[ 725.991589] RDX: 000000c421a04b7c RSI: 000000c426f94f40 RDI: 000000c4274ceaa0
[ 725.991590] RBP: 000000c428be6930 R08: 000000c425521a90 R09: 0000000000000000
[ 725.991590] R10: 0000000000000000 R11: 0000000000000206 R12: ffffffffffffffff
[ 725.991591] R13: 000000000000003e R14: 000000000000003d R15: 0000000000000080
[ 725.991624] INFO: task txg_sync:4202 blocked for more than 120 seconds.
[ 725.998264] Tainted: P O 4.15.0-20-generic #21-Ubuntu
[ 726.005071] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 726.012928] txg_sync D 0 4202 2 0x80000000
[ 726.012930] Call Trace:
[ 726.012933] __schedule+0x297/0x8b0
[ 726.012939] schedule+0x2c/0x80
[ 726.012945] cv_wait_common+0x11e/0x140 [spl]
[ 726.012948] ? wait_woken+0x80/0x80
[ 726.012954] __cv_wait+0x15/0x20 [spl]
[ 726.012981] rrw_enter_write+0x3c/0xa0 [zfs]
[ 726.013006] rrw_enter+0x13/0x20 [zfs]
[ 726.013033] spa_sync+0x7c9/0xd80 [zfs]
[ 726.013062] txg_sync_thread+0x2cd/0x4a0 [zfs]
[ 726.013089] ? txg_quiesce_thread+0x3d0/0x3d0 [zfs]
[ 726.013093] thread_generic_wrapper+0x74/0x90 [spl]
[ 726.013098] kthread+0x121/0x140
[ 726.013101] ? __thread_exit+0x20/0x20 [spl]
[ 726.013103] ? kthread_create_worker_on_cpu+0x70/0x70
[ 726.013104] ret_from_fork+0x22/0x40
[ 726.013313] INFO: task lxd:99919 blocked for more than 120 seconds.
[ 726.019609] Tainted: P O 4.15.0-20-generic #21-Ubuntu
[ 726.026418] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 726.034272] lxd D 0 99919 99626 0x00000000
[ 726.034274] Call Trace:
[ 726.034277] __schedule+0x297/0x8b0
[ 726.034283] ? __wake_up_common+0x73/0x130
[ 726.034286] schedule+0x2c/0x80
[ 726.034290] cv_wait_common+0x11e/0x140 [spl]
[ 726.034293] ? wait_woken+0x80/0x80
[ 726.034297] __cv_wait+0x15/0x20 [spl]
[ 726.034322] txg_wait_synced+0xdd/0x130 [zfs]
[ 726.034349] zil_create+0x249/0x300 [zfs]
[ 726.034376] zil_commit_writer+0x6d1/0x7c0 [zfs]
[ 726.034401] zil_commit.part.14+0x93/0x100 [zfs]
[ 726.034429] zil_commit+0x17/0x20 [zfs]
[ 726.034457] zfs_sync+0x6e/0xb0 [zfs]
[ 726.034484] zpl_sync_fs+0x50/0x80 [zfs]
[ 726.034490] __sync_filesystem+0x33/0x60
[ 726.034493] sync_filesystem+0x39/0x40
[ 726.034495] generic_shutdown_super+0x27/0x120
[ 726.034496] kill_anon_super+0x12/0x20
[ 726.034518] zpl_kill_sb+0x1a/0x20 [zfs]
[ 726.034524] deactivate_locked_super+0x48/0x80
[ 726.034529] deactivate_super+0x40/0x60
[ 726.034532] cleanup_mnt+0x3f/0x80
[ 726.034534] __cleanup_mnt+0x12/0x20
[ 726.034535] task_work_run+0x9d/0xc0
[ 726.034537] exit_to_usermode_loop+0xc0/0xd0
[ 726.034539] do_syscall_64+0x115/0x130
[ 726.034542] entry_SYSCALL_64_after_hwframe+0x3d/0xa2
[ 726.034550] RIP: 0033:0x7fb553b3e8c7
[ 726.034551] RSP: 002b:00007fff426c5388 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
[ 726.034553] RAX: 0000000000000000 RBX: 000000000000000f RCX: 00007fb553b3e8c7
[ 726.034553] RDX: 00007fb55476eb9f RSI: 0000000000000002 RDI: 00007fb554770b6b
[ 726.034554] RBP: 000000000000000c R08: 0000000000000000 R09: 00007fb553b8ae67
[ 726.034555] R10: 0000000000084000 R11: 0000000000000246 R12: 00007fff426c64a0
[ 726.034555] R13: 0000000003176690 R14: 0000000003177810 R15: 00000000031741f0
[ 726.034560] INFO: task zfs:100513 blocked for more than 120 seconds.
[ 726.040936] Tainted: P O 4.15.0-20-generic #21-Ubuntu
[ 726.047746] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 726.055600] zfs D 0 100513 2626 0x00000000
[ 726.055602] Call Trace:
[ 726.055606] __schedule+0x297/0x8b0
[ 726.055609] schedule+0x2c/0x80
[ 726.055613] cv_wait_common+0x11e/0x140 [spl]
[ 726.055615] ? wait_woken+0x80/0x80
[ 726.055619] __cv_wait+0x15/0x20 [spl]
[ 726.055642] rrw_enter_read_impl+0x4e/0x160 [zfs]
[ 726.055666] rrw_enter+0x1c/0x20 [zfs]
[ 726.055691] dsl_pool_hold+0x5a/0x80 [zfs]
[ 726.055713] dmu_objset_hold+0x33/0xa0 [zfs]
[ 726.055740] zfs_ioc_objset_stats+0x32/0xa0 [zfs]
[ 726.055766] zfsdev_ioctl+0x1e0/0x610 [zfs]
[ 726.055771] do_vfs_ioctl+0xa8/0x630
[ 726.055774] ? handle_mm_fault+0xb1/0x1f0
[ 726.055776] ? __do_page_fault+0x270/0x4d0
[ 726.055777] SyS_ioctl+0x79/0x90
[ 726.055779] do_syscall_64+0x73/0x130
[ 726.055781] entry_SYSCALL_64_after_hwframe+0x3d/0xa2
[ 726.055782] RIP: 0033:0x7fd4adc795d7
[ 726.055782] RSP: 002b:00007ffe356b8718 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
[ 726.055783] RAX: ffffffffffffffda RBX: 00007ffe356b8740 RCX: 00007fd4adc795d7
[ 726.055784] RDX: 00007ffe356b8740 RSI: 0000000000005a12 RDI: 0000000000000003
[ 726.055785] RBP: 000055632e278660 R08: 000000000000ffff R09: 00007fd4adcd1ed0
[ 726.055785] R10: 2f746c7561666564 R11: 0000000000000246 R12: 000055632e278660
[ 726.055788] R13: 00007ffe356beec0 R14: 00007fd4af1756e0 R15: 00007ffe356bbe30
[ 726.055791] INFO: task zfs:100584 blocked for more than 120 seconds.
[ 726.062170] Tainted: P O 4.15.0-20-generic #21-Ubuntu
[ 726.068979] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 726.076835] zfs D 0 100584 15513 0x00000000
[ 726.076837] Call Trace:
[ 726.076840] __schedule+0x297/0x8b0
[ 726.076845] schedule+0x2c/0x80
[ 726.076851] cv_wait_common+0x11e/0x140 [spl]
[ 726.076854] ? wait_woken+0x80/0x80
[ 726.076859] __cv_wait+0x15/0x20 [spl]
[ 726.076881] rrw_enter_read_impl+0x4e/0x160 [zfs]
[ 726.076905] rrw_enter+0x1c/0x20 [zfs]
[ 726.076929] dsl_pool_hold+0x5a/0x80 [zfs]
[ 726.076951] dmu_objset_hold+0x33/0xa0 [zfs]
[ 726.076977] zfs_ioc_objset_stats+0x32/0xa0 [zfs]
[ 726.077001] zfsdev_ioctl+0x1e0/0x610 [zfs]
[ 726.077005] do_vfs_ioctl+0xa8/0x630
[ 726.077006] ? handle_mm_fault+0xb1/0x1f0
[ 726.077008] ? __do_page_fault+0x270/0x4d0
[ 726.077010] SyS_ioctl+0x79/0x90
[ 726.077011] do_syscall_64+0x73/0x130
[ 726.077013] entry_SYSCALL_64_after_hwframe+0x3d/0xa2
[ 726.077014] RIP: 0033:0x7fc2734075d7
[ 726.077014] RSP: 002b:00007fff653a4b08 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
[ 726.077015] RAX: ffffffffffffffda RBX: 00007fff653a4b30 RCX: 00007fc2734075d7
[ 726.077016] RDX: 00007fff653a4b30 RSI: 0000000000005a12 RDI: 0000000000000003
[ 726.077017] RBP: 000055f3576e9660 R08: 000000000000ffff R09: 00007fc27345fed0
[ 726.077017] R10: 2f746c7561666564 R11: 0000000000000246 R12: 000055f3576e9660
[ 726.077018] R13: 00007fff653aaec0 R14: 00007fc2749036e0 R15: 00007fff653a8220
[ 846.801124] INFO: task lxd:4455 blocked for more than 120 seconds.
[ 846.807352] Tainted: P O 4.15.0-20-generic #21-Ubuntu
[ 846.814170] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 846.822028] lxd D 0 4455 1 0x00000000
[ 846.822031] Call Trace:
[ 846.822042] __schedule+0x297/0x8b0
[ 846.822045] schedule+0x2c/0x80
[ 846.822047] rwsem_down_write_failed+0x162/0x360
[ 846.822078] ? dbuf_rele_and_unlock+0x1a8/0x4b0 [zfs]
[ 846.822083] call_rwsem_down_write_failed+0x17/0x30
[ 846.822086] ? call_rwsem_down_write_failed+0x17/0x30
[ 846.822087] down_write+0x2d/0x40
[ 846.822091] grab_super+0x30/0x90
[ 846.822118] ? zpl_create+0x160/0x160 [zfs]
[ 846.822121] sget_userns+0x91/0x490
[ 846.822123] ? get_anon_bdev+0x100/0x100
[ 846.822150] ? zpl_create+0x160/0x160 [zfs]
[ 846.822153] sget+0x7d/0xa0
[ 846.822156] ? get_anon_bdev+0x100/0x100
[ 846.822181] zpl_mount+0xa8/0x160 [zfs]
[ 846.822183] mount_fs+0x37/0x150
[ 846.822188] vfs_kern_mount.part.23+0x5d/0x110
[ 846.822189] do_mount+0x5ed/0xce0
[ 846.822190] ? copy_mount_options+0x2c/0x220
[ 846.822192] SyS_mount+0x98/0xe0
[ 846.822195] do_syscall_64+0x73/0x130
[ 846.822196] entry_SYSCALL_64_after_hwframe+0x3d/0xa2
[ 846.822198] RIP: 0033:0x4dbd5a
[ 846.822199] RSP: 002b:000000c428be6890 EFLAGS: 00000206 ORIG_RAX: 00000000000000a5
[ 846.822201] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00000000004dbd5a
[ 846.822203] RDX: 000000c421a04b7c RSI: 000000c426f94f40 RDI: 000000c4274ceaa0
[ 846.822205] RBP: 000000c428be6930 R08: 000000c425521a90 R09: 0000000000000000
[ 846.822206] R10: 0000000000000000 R11: 0000000000000206 R12: ffffffffffffffff
[ 846.822206] R13: 000000000000003e R14: 000000000000003d R15: 0000000000000080
[ 846.822239] INFO: task txg_sync:4202 blocked for more than 120 seconds.
[ 846.828882] Tainted: P O 4.15.0-20-generic #21-Ubuntu
[ 846.835692] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 846.843549] txg_sync D 0 4202 2 0x80000000
[ 846.843551] Call Trace:
[ 846.843554] __schedule+0x297/0x8b0
[ 846.843560] schedule+0x2c/0x80
[ 846.843566] cv_wait_common+0x11e/0x140 [spl]
[ 846.843570] ? wait_woken+0x80/0x80
[ 846.843574] __cv_wait+0x15/0x20 [spl]
[ 846.843603] rrw_enter_write+0x3c/0xa0 [zfs]
[ 846.843629] rrw_enter+0x13/0x20 [zfs]
[ 846.843654] spa_sync+0x7c9/0xd80 [zfs]
[ 846.843682] txg_sync_thread+0x2cd/0x4a0 [zfs]
[ 846.843708] ? txg_quiesce_thread+0x3d0/0x3d0 [zfs]
[ 846.843713] thread_generic_wrapper+0x74/0x90 [spl]
[ 846.843717] kthread+0x121/0x140
[ 846.843720] ? __thread_exit+0x20/0x20 [spl]
[ 846.843721] ? kthread_create_worker_on_cpu+0x70/0x70
[ 846.843723] ret_from_fork+0x22/0x40
[ 846.843931] INFO: task lxd:99919 blocked for more than 120 seconds.
[ 846.850227] Tainted: P O 4.15.0-20-generic #21-Ubuntu
[ 846.857040] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 846.864892] lxd D 0 99919 99626 0x00000000
[ 846.864894] Call Trace:
[ 846.864897] __schedule+0x297/0x8b0
[ 846.864903] ? __wake_up_common+0x73/0x130
[ 846.864906] schedule+0x2c/0x80
[ 846.864910] cv_wait_common+0x11e/0x140 [spl]
[ 846.864912] ? wait_woken+0x80/0x80
[ 846.864917] __cv_wait+0x15/0x20 [spl]
[ 846.864942] txg_wait_synced+0xdd/0x130 [zfs]
[ 846.864971] zil_create+0x249/0x300 [zfs]
[ 846.864998] zil_commit_writer+0x6d1/0x7c0 [zfs]
[ 846.865023] zil_commit.part.14+0x93/0x100 [zfs]
[ 846.865051] zil_commit+0x17/0x20 [zfs]
[ 846.865080] zfs_sync+0x6e/0xb0 [zfs]
[ 846.865107] zpl_sync_fs+0x50/0x80 [zfs]
[ 846.865111] __sync_filesystem+0x33/0x60
[ 846.865113] sync_filesystem+0x39/0x40
[ 846.865114] generic_shutdown_super+0x27/0x120
[ 846.865116] kill_anon_super+0x12/0x20
[ 846.865138] zpl_kill_sb+0x1a/0x20 [zfs]
[ 846.865140] deactivate_locked_super+0x48/0x80
[ 846.865143] deactivate_super+0x40/0x60
[ 846.865145] cleanup_mnt+0x3f/0x80
[ 846.865147] __cleanup_mnt+0x12/0x20
[ 846.865148] task_work_run+0x9d/0xc0
[ 846.865150] exit_to_usermode_loop+0xc0/0xd0
[ 846.865152] do_syscall_64+0x115/0x130
[ 846.865153] entry_SYSCALL_64_after_hwframe+0x3d/0xa2
[ 846.865154] RIP: 0033:0x7fb553b3e8c7
[ 846.865155] RSP: 002b:00007fff426c5388 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
[ 846.865156] RAX: 0000000000000000 RBX: 000000000000000f RCX: 00007fb553b3e8c7
[ 846.865158] RDX: 00007fb55476eb9f RSI: 0000000000000002 RDI: 00007fb554770b6b
[ 846.865159] RBP: 000000000000000c R08: 0000000000000000 R09: 00007fb553b8ae67
[ 846.865162] R10: 0000000000084000 R11: 0000000000000246 R12: 00007fff426c64a0
[ 846.865162] R13: 0000000003176690 R14: 0000000003177810 R15: 00000000031741f0
[ 846.865167] INFO: task zfs:100513 blocked for more than 120 seconds.
[ 846.871546] Tainted: P O 4.15.0-20-generic #21-Ubuntu
[ 846.878357] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 846.886214] zfs D 0 100513 2626 0x00000000
[ 846.886215] Call Trace:
[ 846.886218] __schedule+0x297/0x8b0
[ 846.886223] schedule+0x2c/0x80
[ 846.886230] cv_wait_common+0x11e/0x140 [spl]
[ 846.886232] ? wait_woken+0x80/0x80
[ 846.886237] __cv_wait+0x15/0x20 [spl]
[ 846.886261] rrw_enter_read_impl+0x4e/0x160 [zfs]
[ 846.886284] rrw_enter+0x1c/0x20 [zfs]
[ 846.886309] dsl_pool_hold+0x5a/0x80 [zfs]
[ 846.886331] dmu_objset_hold+0x33/0xa0 [zfs]
[ 846.886357] zfs_ioc_objset_stats+0x32/0xa0 [zfs]
[ 846.886383] zfsdev_ioctl+0x1e0/0x610 [zfs]
[ 846.886388] do_vfs_ioctl+0xa8/0x630
[ 846.886391] ? handle_mm_fault+0xb1/0x1f0
[ 846.886394] ? __do_page_fault+0x270/0x4d0
[ 846.886396] SyS_ioctl+0x79/0x90
[ 846.886397] do_syscall_64+0x73/0x130
[ 846.886399] entry_SYSCALL_64_after_hwframe+0x3d/0xa2
[ 846.886400] RIP: 0033:0x7fd4adc795d7
[ 846.886402] RSP: 002b:00007ffe356b8718 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
[ 846.886405] RAX: ffffffffffffffda RBX: 00007ffe356b8740 RCX: 00007fd4adc795d7
[ 846.886406] RDX: 00007ffe356b8740 RSI: 0000000000005a12 RDI: 0000000000000003
[ 846.886406] RBP: 000055632e278660 R08: 000000000000ffff R09: 00007fd4adcd1ed0
[ 846.886407] R10: 2f746c7561666564 R11: 0000000000000246 R12: 000055632e278660
[ 846.886408] R13: 00007ffe356beec0 R14: 00007fd4af1756e0 R15: 00007ffe356bbe30
[ 846.886410] INFO: task zfs:100584 blocked for more than 120 seconds.
[ 846.892790] Tainted: P O 4.15.0-20-generic #21-Ubuntu
[ 846.899598] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 846.907454] zfs D 0 100584 15513 0x00000000
[ 846.907456] Call Trace:
[ 846.907459] __schedule+0x297/0x8b0
[ 846.907465] schedule+0x2c/0x80
[ 846.907470] cv_wait_common+0x11e/0x140 [spl]
[ 846.907471] ? wait_woken+0x80/0x80
[ 846.907477] __cv_wait+0x15/0x20 [spl]
[ 846.907499] rrw_enter_read_impl+0x4e/0x160 [zfs]
[ 846.907523] rrw_enter+0x1c/0x20 [zfs]
[ 846.907547] dsl_pool_hold+0x5a/0x80 [zfs]
[ 846.907568] dmu_objset_hold+0x33/0xa0 [zfs]
[ 846.907594] zfs_ioc_objset_stats+0x32/0xa0 [zfs]
[ 846.907618] zfsdev_ioctl+0x1e0/0x610 [zfs]
[ 846.907622] do_vfs_ioctl+0xa8/0x630
[ 846.907624] ? handle_mm_fault+0xb1/0x1f0
[ 846.907625] ? __do_page_fault+0x270/0x4d0
[ 846.907627] SyS_ioctl+0x79/0x90
[ 846.907628] do_syscall_64+0x73/0x130
[ 846.907630] entry_SYSCALL_64_after_hwframe+0x3d/0xa2
[ 846.907631] RIP: 0033:0x7fc2734075d7
[ 846.907631] RSP: 002b:00007fff653a4b08 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
[ 846.907633] RAX: ffffffffffffffda RBX: 00007fff653a4b30 RCX: 00007fc2734075d7
[ 846.907633] RDX: 00007fff653a4b30 RSI: 0000000000005a12 RDI: 0000000000000003
[ 846.907634] RBP: 000055f3576e9660 R08: 000000000000ffff R09: 00007fc27345fed0
[ 846.907635] R10: 2f746c7561666564 R11: 0000000000000246 R12: 000055f3576e9660
[ 846.907637] R13: 00007fff653aaec0 R14: 00007fc2749036e0 R15: 00007fff653a8220

Contents of "/proc/spl/kstat/zfs/arcstats"

13 1 0x01 96 4608 11300672527 1808059980062
name type data
hits 4 44186496
misses 4 1247761
demand_data_hits 4 3327097
demand_data_misses 4 17953
demand_metadata_hits 4 39832270
demand_metadata_misses 4 1076950
prefetch_data_hits 4 1357
prefetch_data_misses 4 23
prefetch_metadata_hits 4 1025772
prefetch_metadata_misses 4 152835
mru_hits 4 18193851
mru_ghost_hits 4 0
mfu_hits 4 24976976
mfu_ghost_hits 4 0
deleted 4 10
mutex_miss 4 0
access_skip 4 68
evict_skip 4 1
evict_not_enough 4 0
evict_l2_cached 4 0
evict_l2_eligible 4 101376
evict_l2_ineligible 4 2048
evict_l2_skip 4 0
hash_elements 4 38683
hash_elements_max 4 57741
hash_collisions 4 1520
hash_chains 4 5
hash_chain_max 4 1
p 4 16815604736
c 4 33631209472
c_min 4 2101950592
c_max 4 33631209472
size 4 833199872
compressed_size 4 286609408
uncompressed_size 4 831992320
overhead_size 4 330568192
hdr_size 4 14660144
data_size 4 193579520
metadata_size 4 423598080
dbuf_size 4 46065424
dnode_size 4 112384064
bonus_size 4 42912640
anon_size 4 36502016
anon_evictable_data 4 0
anon_evictable_metadata 4 0
mru_size 4 310932480
mru_evictable_data 4 27623424
mru_evictable_metadata 4 136801792
mru_ghost_size 4 0
mru_ghost_evictable_data 4 0
mru_ghost_evictable_metadata 4 0
mfu_size 4 269743104
mfu_evictable_data 4 53612032
mfu_evictable_metadata 4 3195392
mfu_ghost_size 4 0
mfu_ghost_evictable_data 4 0
mfu_ghost_evictable_metadata 4 0
l2_hits 4 0
l2_misses 4 0
l2_feeds 4 0
l2_rw_clash 4 0
l2_read_bytes 4 0
l2_write_bytes 4 0
l2_writes_sent 4 0
l2_writes_done 4 0
l2_writes_error 4 0
l2_writes_lock_retry 4 0
l2_evict_lock_retry 4 0
l2_evict_reading 4 0
l2_evict_l1cached 4 0
l2_free_on_write 4 0
l2_abort_lowmem 4 0
l2_cksum_bad 4 0
l2_io_error 4 0
l2_size 4 0
l2_asize 4 0
l2_hdr_size 4 0
memory_throttle_count 4 0
memory_direct_count 4 0
memory_indirect_count 4 0
memory_all_bytes 4 67262418944
memory_free_bytes 4 57157578752
memory_available_bytes 3 56106606592
arc_no_grow 4 0
arc_tempreserve 4 0
arc_loaned_bytes 4 0
arc_prune 4 0
arc_meta_used 4 639620352
arc_meta_limit 4 25223407104
arc_dnode_limit 4 2522340710
arc_meta_max 4 965175896
arc_meta_min 4 16777216
sync_wait_for_async 4 168
demand_hit_predictive_prefetch 4 999
arc_need_free 4 0
arc_sys_free 4 1050975296

Command "slabtop -o"

 Active / Total Objects (% used) : 28354235 / 29140626 (97.3%)
 Active / Total Slabs (% used) : 382017 / 382017 (100.0%)
 Active / Total Caches (% used) : 95 / 128 (74.2%)
 Active / Total Size (% used) : 4580408.56K / 4743868.00K (96.6%)
 Minimum / Average / Maximum Object : 0.01K / 0.16K / 21.81K

  OBJS ACTIVE USE OBJ SIZE SLABS OBJ/SLAB CACHE SIZE NAME
17206144 17204917 0% 0.03K 134423 128 537692K kmalloc-32
1141392 966790 0% 0.19K 27176 42 217408K dentry
1114496 1004537 0% 0.06K 17414 64 69656K kmalloc-64
1088192 1078186 0% 0.50K 17003 64 544096K kmalloc-512
1038300 714247 0% 0.13K 17305 60 138440K kernfs_node_cache
937536 931296 0% 0.25K 14649 64 234384K filp
684160 682244 0% 0.06K 10690 64 42760K pid
582099 569877 0% 0.59K 10983 53 351456K inode_cache
520104 518529 0% 0.20K 13336 39 106688K vm_area_struct
404334 388371 0% 0.09K 9627 42 38508K kmalloc-96
342286 341596 0% 0.09K 7441 46 29764K anon_vma
342016 338948 0% 0.25K 5344 64 85504K kmalloc-256
277032 276822 0% 0.19K 6596 42 52768K cred_jar
248352 241634 0% 0.66K 5174 48 165568K proc_inode_cache
248320 233052 0% 0.01K 485 512 1940K kmalloc-8
214984 143177 0% 0.57K 3839 56 122848K radix_tree_node

[Colin Ian King (colin-king)]

Upstream ZFS fix:

commit ac09630d8b0bf6c92084a30fdaefd03fd0adbdc1
Author: Brian Behlendorf <email address hidden>
Date: Wed Jul 11 15:49:10 2018 -0700

    Fix zpl_mount() deadlock

[Launchpad Janitor (janitor)]

This bug was fixed in the package zfs-linux - 0.7.9-3ubuntu4

---------------
zfs-linux (0.7.9-3ubuntu4) cosmic; urgency=medium

  * Fix zpl_mount() deadlock (LP: #1781364)
    - Upstream ZFS fix ac09630d8b0b ("Fix zpl_mount() deadlock")
      fixes deadlock on multiple parallelized mount/umounts

 -- Colin Ian King <email address hidden> Thu, 12 Jul 2018 09:18:24 +0100

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Łukasz Zemczak (sil2100)]

Hello Colin, or anyone else affected,

Accepted zfs-linux into bionic-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/zfs-linux/0.7.5-1ubuntu16.3 in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation on how to enable and use -proposed.Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug, mentioning the version of the package you tested and change the tag from verification-needed-bionic to verification-done-bionic. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed-bionic. In either case, without details of your testing we will not be able to proceed.

Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance!

[Colin Ian King (colin-king)]

This fix will only work once it lands in the updated kernel as well as the user space packages, so please test once the updated kernel is also in -proposed.

[Vasiliy (vvershkov)]

My experiments was here: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1773392

I installed new 18.04 + zfs + lxd - zfs hangs (well, that would be awkward if would not)
+zfsutils-linux=0.7.5-1ubuntu16.3 - zfs hangs (ok, we need upgrade kernel too)
+kernel=4.15.0.28 (all packages) - still hangs :( Am I missing something?
+everything_0.7.5=0.7.5-1ubuntu16.3 - still hangs...
+upgrade+dist-upgrade from proposed - still hangs...

So this bug doesn't fixed for me... And it is strange, because I used to install zfs 0.7.9 from source with commit that fixed bug (https://github.com/zfsonlinux/zfs/pull/7693) - and that worked for me on default kernel (4.15.0.20).

[Colin Ian King (colin-king)]

Vasiliy, please refer to comment #8

[Colin Ian King (colin-king)]

The kernel driver fix will land in the next -proposed kernel as the Ubuntu ZFS driver comes bundled with the kernel.

If you build zfs from source, then that will build the kernel driver as a DKMS module with the fix in it and *that* will work.

One needs both the zfs userspace and the kernel for the entire bug fix.

[Vasiliy (vvershkov)]

Ah, I thought that kernel (module) in proposed already patched. I understood comment #8 like "don't forget to upgrade kernel from proposed!", while it is "wait until fixed kernel in proposed".
Now it makes sense, thank you.

[Simos Xenitellis  (simosx)]

zfsutils-linux (zfs-linux, zfs-linux_0.7.5-1ubuntu16.3) is already in proposed,
https://launchpad.net/ubuntu/bionic/+queue?queue_state=3&queue_text=zfs-linux

Please report when linux-image gets into -proposed,
https://launchpad.net/ubuntu/bionic/+queue?queue_state=3&queue_text=linux-image

[Vasiliy (vvershkov)]

It seems like 4.15.0-29 (uploaded right now to proposed) is not the kernel we are looking for.

[Simos Xenitellis  (simosx)]

@Vasiliy: Indeed.

The version in -proposed is "4.15.0-29.31" (source: https://launchpad.net/ubuntu/bionic/+queue?queue_state=3&queue_text=linux-image)

The page for that version at https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1782173
does not have a reference to this bug number #1781364.

[Colin Ian King (colin-king)]

The bug will be automatically updated when the -proposed kernel containing the fix is ready, please wait for that message.

[Launchpad Janitor (janitor)]

This bug was fixed in the package linux - 4.17.0-6.7

---------------
linux (4.17.0-6.7) cosmic; urgency=medium

  * linux: 4.17.0-6.7 -proposed tracker (LP: #1783396)

  * [Regression] EXT4-fs error (device sda2): ext4_validate_block_bitmap:383:
    comm stress-ng: bg 4705: bad block bitmap checksum (LP: #1781709)
    - SAUCE: Revert "UBUNTU: SAUCE: ext4: fix ext4_validate_inode_bitmap: comm
      stress-ng: Corrupt inode bitmap"
    - SAUCE: ext4: check for allocation block validity with block group locked

  * Cosmic update to 4.17.9 stable release (LP: #1783201)
    - userfaultfd: hugetlbfs: fix userfaultfd_huge_must_wait() pte access
    - mm: hugetlb: yield when prepping struct pages
    - mm: teach dump_page() to correctly output poisoned struct pages
    - PCI / ACPI / PM: Resume bridges w/o drivers on suspend-to-RAM
    - ACPICA: Drop leading newlines from error messages
    - ACPI / battery: Safe unregistering of hooks
    - drm/amdgpu: Make struct amdgpu_atif private to amdgpu_acpi.c
    - tracing: Avoid string overflow
    - tracing: Fix missing return symbol in function_graph output
    - scsi: sg: mitigate read/write abuse
    - scsi: aacraid: Fix PD performance regression over incorrect qd being set
    - scsi: target: Fix truncated PR-in ReadKeys response
    - s390: Correct register corruption in critical section cleanup
    - drbd: fix access after free
    - vfio: Use get_user_pages_longterm correctly
    - ARM: dts: imx51-zii-rdu1: fix touchscreen pinctrl
    - ARM: dts: omap3: Fix am3517 mdio and emac clock references
    - ARM: dts: dra7: Disable metastability workaround for USB2
    - cifs: Fix use after free of a mid_q_entry
    - cifs: Fix memory leak in smb2_set_ea()
    - cifs: Fix slab-out-of-bounds in send_set_info() on SMB2 ACE setting
    - cifs: Fix infinite loop when using hard mount option
    - drm: Use kvzalloc for allocating blob property memory
    - drm/udl: fix display corruption of the last line
    - drm/amdgpu: Add amdgpu_atpx_get_dhandle()
    - drm/amdgpu: Dynamically probe for ATIF handle (v2)
    - jbd2: don't mark block as modified if the handle is out of credits
    - ext4: add corruption check in ext4_xattr_set_entry()
    - ext4: always verify the magic number in xattr blocks
    - ext4: make sure bitmaps and the inode table don't overlap with bg
      descriptors
    - ext4: always check block group bounds in ext4_init_block_bitmap()
    - ext4: only look at the bg_flags field if it is valid
    - ext4: verify the depth of extent tree in ext4_find_extent()
    - ext4: include the illegal physical block in the bad map ext4_error msg
    - ext4: clear i_data in ext4_inode_info when removing inline data
    - ext4: never move the system.data xattr out of the inode body
    - ext4: avoid running out of journal credits when appending to an inline file
    - ext4: add more inode number paranoia checks
    - ext4: add more mount time checks of the superblock
    - ext4: check superblock mapped prior to committing
    - HID: i2c-hid: Fix "incomplete report" noise
    - HID: hiddev: fix potential Spectre v1
    - HID: debug: check length before copy_to_user()
    - HID: core: allow concurrent registr...

[Brad Figg (brad-figg)]

This bug is awaiting verification that the kernel in -proposed solves the problem. Please test the kernel and update this bug with the results. If the problem is solved, change the tag 'verification-needed-xenial' to 'verification-done-xenial'. If the problem still exists, change the tag 'verification-needed-xenial' to 'verification-failed-xenial'.

If verification is not done by 5 working days from today, this fix will be dropped from the source code, and this bug will be closed.

See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Thank you!

[Brad Figg (brad-figg)]

This bug is awaiting verification that the kernel in -proposed solves the problem. Please test the kernel and update this bug with the results. If the problem is solved, change the tag 'verification-needed-bionic' to 'verification-done-bionic'. If the problem still exists, change the tag 'verification-needed-bionic' to 'verification-failed-bionic'.

If verification is not done by 5 working days from today, this fix will be dropped from the source code, and this bug will be closed.

See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Thank you!

[Vasiliy (vvershkov)]

I can confirm now that fix works for me.
Do somebody knows when this kernel and zfsutils package will move from proposed to updates?

[Colin Ian King (colin-king)]

Verified passed for Ubuntu Bionic using the reproducer described in comment #1. Marking as verified.

[Colin Ian King (colin-king)]

Verified passed for Ubuntu Xenial using the reproducer described in comment #1. Marking as verified.

[Colin Ian King (colin-king)]

@Vasiliy, hopefully by early next week.

[Brian Murray (brian-murray)]

The verification of the Stable Release Update for zfs-linux has completed successfully and the package has now been released to -updates. Subsequently, the Ubuntu Stable Release Updates Team is being unsubscribed and will not receive messages about this bug report. In the event that you encounter a regression using the package from -updates please report a new bug using ubuntu-bug and tag the bug report regression-update so we can easily find any regressions.

[Launchpad Janitor (janitor)]

This bug was fixed in the package zfs-linux - 0.7.5-1ubuntu16.3

---------------
zfs-linux (0.7.5-1ubuntu16.3) bionic; urgency=medium

  * Fix zpl_mount() deadlock (LP: #1781364)
    - Upstream ZFS fix ac09630d8b0b ("Fix zpl_mount() deadlock")
      fixes deadlock on multiple parallelized mount/umounts

 -- Colin Ian King <email address hidden> Thu, 12 Jul 2018 09:18:24 +0100

[Sam Van den Eynde (samvde)]

I don't see the confirmation for Bionic in this bug report. Any update when the 4.17 kernel lands in bionic-proposed? Or do I need another kernel version for Bionic? What do I need exactly for my Bionic server?

This bug prevents me from updating my lxd containers, it will hang the system consistently.

[Colin Ian King (colin-king)]

The bug will be fixed once the zfs package and the bionic kernel (that contains the zfs driver changes) will be released. So far, just the zfs package has been released and we are waiting for the kernel to complete the SRU update and verification phase - this takes a bit longer as the kernel contains a lot more other changes and we have to do more exhaustive testing.

[Launchpad Janitor (janitor)]

This bug was fixed in the package linux - 4.15.0-33.36

---------------
linux (4.15.0-33.36) bionic; urgency=medium

  * linux: 4.15.0-33.36 -proposed tracker (LP: #1787149)

  * RTNL assertion failure on ipvlan (LP: #1776927)
    - ipvlan: drop ipv6 dependency
    - ipvlan: use per device spinlock to protect addrs list updates
    - SAUCE: fix warning from "ipvlan: drop ipv6 dependency"

  * ubuntu_bpf_jit test failed on Bionic s390x systems (LP: #1753941)
    - test_bpf: flag tests that cannot be jited on s390

  * HDMI/DP audio can't work on the laptop of Dell Latitude 5495 (LP: #1782689)
    - drm/nouveau: fix nouveau_dsm_get_client_id()'s return type
    - drm/radeon: fix radeon_atpx_get_client_id()'s return type
    - drm/amdgpu: fix amdgpu_atpx_get_client_id()'s return type
    - platform/x86: apple-gmux: fix gmux_get_client_id()'s return type
    - ALSA: hda: use PCI_BASE_CLASS_DISPLAY to replace PCI_CLASS_DISPLAY_VGA
    - vga_switcheroo: set audio client id according to bound GPU id

  * locking sockets broken due to missing AppArmor socket mediation patches
    (LP: #1780227)
    - UBUNTU SAUCE: apparmor: fix apparmor mediating locking non-fs, unix sockets

  * Update2 for ocxl driver (LP: #1781436)
    - ocxl: Fix page fault handler in case of fault on dying process

  * netns: unable to follow an interface that moves to another netns
    (LP: #1774225)
    - net: core: Expose number of link up/down transitions
    - dev: always advertise the new nsid when the netns iface changes
    - dev: advertise the new ifindex when the netns iface changes

  * [Bionic] Disk IO hangs when using BFQ as io scheduler (LP: #1780066)
    - block, bfq: fix occurrences of request finish method's old name
    - block, bfq: remove batches of confusing ifdefs
    - block, bfq: add requeue-request hook

  * HP ProBook 455 G5 needs mute-led-gpio fixup (LP: #1781763)
    - ALSA: hda: add mute led support for HP ProBook 455 G5

  * [Bionic] bug fixes to improve stability of the ThunderX2 i2c driver
    (LP: #1781476)
    - i2c: xlp9xx: Fix issue seen when updating receive length
    - i2c: xlp9xx: Make sure the transfer size is not more than
      I2C_SMBUS_BLOCK_SIZE

  * x86/kvm: fix LAPIC timer drift when guest uses periodic mode (LP: #1778486)
    - x86/kvm: fix LAPIC timer drift when guest uses periodic mode

  * Please include ax88179_178a and r8152 modules in d-i udeb (LP: #1771823)
    - [Config:] d-i: Add ax88179_178a and r8152 to nic-modules

  * Nvidia fails after switching its mode (LP: #1778658)
    - PCI: Restore config space on runtime resume despite being unbound

  * Kernel error "task zfs:pid blocked for more than 120 seconds" (LP: #1781364)
    - SAUCE: (noup) zfs to 0.7.5-1ubuntu16.3

  * CVE-2018-12232
    - PATCH 1/1] socket: close race condition between sock_close() and
      sockfs_setattr()

  * CVE-2018-10323
    - xfs: set format back to extents if xfs_bmap_extents_to_btree

  * change front mic location for more lenovo m7/8/9xx machines (LP: #1781316)
    - ALSA: hda/realtek - Fix the problem of two front mics on more machines
    - ALSA: hda/realtek - two more lenovo models need fixup of MIC_LOCATION

  * Cephfs + fscache: unab...

[Launchpad Janitor (janitor)]

This bug was fixed in the package linux - 4.4.0-134.160

---------------
linux (4.4.0-134.160) xenial; urgency=medium

  * linux: 4.4.0-134.160 -proposed tracker (LP: #1787177)

  * locking sockets broken due to missing AppArmor socket mediation patches
    (LP: #1780227)
    - UBUNTU SAUCE: apparmor: fix apparmor mediating locking non-fs, unix sockets

  * Backport namespaced fscaps to xenial 4.4 (LP: #1778286)
    - Introduce v3 namespaced file capabilities
    - commoncap: move assignment of fs_ns to avoid null pointer dereference
    - capabilities: fix buffer overread on very short xattr
    - commoncap: Handle memory allocation failure.

  * Xenial update to 4.4.140 stable release (LP: #1784409)
    - usb: cdc_acm: Add quirk for Uniden UBC125 scanner
    - USB: serial: cp210x: add CESINEL device ids
    - USB: serial: cp210x: add Silicon Labs IDs for Windows Update
    - n_tty: Fix stall at n_tty_receive_char_special().
    - staging: android: ion: Return an ERR_PTR in ion_map_kernel
    - n_tty: Access echo_* variables carefully.
    - x86/boot: Fix early command-line parsing when matching at end
    - ath10k: fix rfc1042 header retrieval in QCA4019 with eth decap mode
    - i2c: rcar: fix resume by always initializing registers before transfer
    - ipv4: Fix error return value in fib_convert_metrics()
    - kprobes/x86: Do not modify singlestep buffer while resuming
    - nvme-pci: initialize queue memory before interrupts
    - netfilter: nf_tables: use WARN_ON_ONCE instead of BUG_ON in nft_do_chain()
    - ARM: dts: imx6q: Use correct SDMA script for SPI5 core
    - ubi: fastmap: Correctly handle interrupted erasures in EBA
    - mm: hugetlb: yield when prepping struct pages
    - tracing: Fix missing return symbol in function_graph output
    - scsi: sg: mitigate read/write abuse
    - s390: Correct register corruption in critical section cleanup
    - drbd: fix access after free
    - cifs: Fix infinite loop when using hard mount option
    - jbd2: don't mark block as modified if the handle is out of credits
    - ext4: make sure bitmaps and the inode table don't overlap with bg
      descriptors
    - ext4: always check block group bounds in ext4_init_block_bitmap()
    - ext4: only look at the bg_flags field if it is valid
    - ext4: verify the depth of extent tree in ext4_find_extent()
    - ext4: include the illegal physical block in the bad map ext4_error msg
    - ext4: clear i_data in ext4_inode_info when removing inline data
    - ext4: add more inode number paranoia checks
    - ext4: add more mount time checks of the superblock
    - ext4: check superblock mapped prior to committing
    - HID: i2c-hid: Fix "incomplete report" noise
    - HID: hiddev: fix potential Spectre v1
    - HID: debug: check length before copy_to_user()
    - x86/mce: Detect local MCEs properly
    - x86/mce: Fix incorrect "Machine check from unknown source" message
    - media: cx25840: Use subdev host data for PLL override
    - mm, page_alloc: do not break __GFP_THISNODE by zonelist reset
    - dm bufio: avoid sleeping while holding the dm_bufio lock
    - dm bufio: drop the lock when doing GFP_NOIO allocation
    - mtd: rawnand: mxc: set spa...

[Colin Ian King (colin-king)]

Diff:

http://launchpadlibrarian.net/388038683/zfs-linux_0.6.5.6-0ubuntu24_0.6.5.6-0ubuntu25.diff.gz

[Colin Ian King (colin-king)]

Wrong URL, ignore that.

[Colin Ian King (colin-king)]

Diff: http://launchpadlibrarian.net/388404653/zfs-linux_0.6.5.6-0ubuntu24_0.6.5.6-0ubuntu25.diff.gz

[Łukasz Zemczak (sil2100)]

Hello Colin, or anyone else affected,

Accepted zfs-linux into xenial-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/zfs-linux/0.6.5.6-0ubuntu25 in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation on how to enable and use -proposed. Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug, mentioning the version of the package you tested and change the tag from verification-needed-xenial to verification-done-xenial. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed-xenial. In either case, without details of your testing we will not be able to proceed.

Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance for helping!

N.B. The updated package will be released to -updates after the bug(s) fixed by this package have been verified and the package has been in -proposed for a minimum of 7 days.

[Colin Ian King (colin-king)]

Tested 0.6.5.6-0ubuntu25 and it works without any issues, so marking this as verified.

[Launchpad Janitor (janitor)]

This bug was fixed in the package zfs-linux - 0.6.5.6-0ubuntu25

---------------
zfs-linux (0.6.5.6-0ubuntu25) xenial; urgency=medium

  * Fix zpl_mount() deadlock (LP: #1781364)
    - Upstream ZFS fix ac09630d8b0b ("Fix zpl_mount() deadlock")
      fixes deadlock on multiple parallelized mount/umounts

 -- Colin Ian King <email address hidden> Thu, 12 Jul 2018 09:18:24 +0100