I upgraded from kernel 4.4 to 4.8 on 16.04 LTS in the hope the issue would go away. My hang is in btrfs-cleaner, not sure if this is the same bug or not.
This related thread is interesting but does not seem to resolve it: https://patchwork.kernel.org/patch/8284721/ Linux nuc 4.8.0-54-generic #57~16.04.1-Ubuntu SMP Wed May 24 16:22:28 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux Jun 19 01:51:14 nuc kernel: INFO: task btrfs-cleaner:408 blocked for more than 120 seconds. Jun 19 01:51:14 nuc kernel: Not tainted 4.8.0-54-generic #57~16.04.1-Ubuntu Jun 19 01:51:14 nuc kernel: "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. Jun 19 01:51:14 nuc kernel: btrfs-cleaner D ffff9478128d3d00 0 408 2 0x00000000 Jun 19 01:51:14 nuc kernel: ffff9478128d3d00 ffff9478128d3cc8 ffff94781c2a6ac0 ffff9478137a0000 Jun 19 01:51:14 nuc kernel: ffffffffa4cc7492 ffff9478128d4000 ffff947813e841f0 ffff947813e84000 Jun 19 01:51:14 nuc kernel: ffff947813e841f0 0000000000000001 ffff9478128d3d18 ffffffffa5496045 Jun 19 01:51:14 nuc kernel: Call Trace: Jun 19 01:51:14 nuc kernel: [<ffffffffa4cc7492>] ? autoremove_wake_function+0x12/0x40 Jun 19 01:51:14 nuc kernel: [<ffffffffa5496045>] schedule+0x35/0x80 Jun 19 01:51:14 nuc kernel: [<ffffffffc079fc73>] wait_current_trans.isra.21+0xd3/0x120 [btrfs] Jun 19 01:51:14 nuc kernel: [<ffffffffa4cc7480>] ? wake_atomic_t_function+0x60/0x60 Jun 19 01:51:14 nuc kernel: [<ffffffffc07a248f>] start_transaction+0x2cf/0x4c0 [btrfs] Jun 19 01:51:14 nuc kernel: [<ffffffffc07a2698>] btrfs_start_transaction+0x18/0x20 [btrfs] Jun 19 01:51:14 nuc kernel: [<ffffffffc0788f72>] btrfs_drop_snapshot+0x4b2/0x800 [btrfs] Jun 19 01:51:14 nuc kernel: [<ffffffffa5495b87>] ? __schedule+0x307/0x790 Jun 19 01:51:14 nuc kernel: [<ffffffffc07a1624>] btrfs_clean_one_deleted_snapshot+0xb4/0x100 [btrfs] Jun 19 01:51:14 nuc kernel: [<ffffffffc0797dbd>] cleaner_kthread+0x15d/0x1d0 [btrfs] Jun 19 01:51:14 nuc kernel: [<ffffffffc0797c60>] ? btrfs_destroy_pinned_extent+0xf0/0xf0 [btrfs] Jun 19 01:51:14 nuc kernel: [<ffffffffa4ca3fb8>] kthread+0xd8/0xf0 Jun 19 01:51:14 nuc kernel: [<ffffffffa549aa9f>] ret_from_fork+0x1f/0x40 Jun 19 01:51:14 nuc kernel: [<ffffffffa4ca3ee0>] ? kthread_create_on_node+0x1e0/0x1e0 -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1454903 Title: Btrfs Fails to Mount Drive - btrfs-transaction blocked for more than 120 seconds. Status in linux package in Ubuntu: Confirmed Bug description: Call Trace: kernel: ffff880408609800 ffff8803e9cba200 ffff8803d06f7398 ffff8803bc89fe00 kernel: 0000000000014200 ffff88040ce9f5c0 ffff880407f9d850 ffff8803bc89fdd8 kernel: ffff8803bc89fdc8 ffff880407f9d850 0000000000014200 ffff8803bc89ffd8 kernel: btrfs-transacti D ffff8803bc89fdc8 0 4187 2 0x00000000 kernel: "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kernel: Not tainted 3.19.0-16-generic #16-Ubuntu kernel: INFO: task btrfs-transacti:4187 blocked for more than 120 seconds. kernel: [<ffffffff817c934d>] system_call_fastpath+0x16/0x1b kernel: [<ffffffff812175db>] SyS_mount+0x8b/0xd0 kernel: [<ffffffff812169a4>] do_mount+0x204/0xb20 kernel: [<ffffffff81213b4b>] vfs_kern_mount+0x6b/0x120 kernel: [<ffffffff8119b805>] ? __alloc_percpu+0x15/0x20 kernel: [<ffffffff811f7428>] mount_fs+0x38/0x1c0 kernel: [<ffffffffc0333b00>] btrfs_mount+0x850/0x920 [btrfs] kernel: [<ffffffffc035db23>] open_ctree+0x1813/0x2090 [btrfs] kernel: [<ffffffffc039f9c0>] ? replay_one_extent+0x6b0/0x6b0 [btrfs] kernel: [<ffffffffc03a2214>] btrfs_recover_log_trees+0x1d4/0x470 [btrfs] kernel: [<ffffffffc039abbb>] walk_log_tree+0xbb/0x1a0 [btrfs] kernel: [<ffffffffc039a679>] walk_down_log_tree+0x1d9/0x420 [btrfs] kernel: [<ffffffffc0382f34>] ? alloc_extent_buffer+0x34/0x350 [btrfs] kernel: [<ffffffffc039b04e>] insert_orphan_item+0x5e/0x90 [btrfs] ProblemType: Bug DistroRelease: Ubuntu 15.04 Package: linux-image-3.19.0-16-generic 3.19.0-16.16 ProcVersionSignature: Ubuntu 3.19.0-16.16-generic 3.19.3 Uname: Linux 3.19.0-16-generic x86_64 ApportVersion: 2.17.2-0ubuntu1 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC0: jdfalk 3444 F.... pulseaudio Date: Wed May 13 19:03:10 2015 HibernationDevice: RESUME=/dev/mapper/sda5_crypt InstallationDate: Installed on 2015-05-10 (4 days ago) InstallationMedia: Ubuntu-Server 15.04 "Vivid Vervet" - Release amd64 (20150422) MachineType: Gigabyte Technology Co., Ltd. To be filled by O.E.M. ProcEnviron: TERM=xterm-256color PATH=(custom, no user) LANG=en_US.UTF-8 SHELL=/bin/bash ProcFB: 0 inteldrmfb ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-3.19.0-16-generic.efi.signed root=UUID=51a981ad-aeb0-4bd7-91c6-2d493155c812 ro rootflags=subvol=@ crashkernel=384M-:128M PulseList: Error: command ['pacmd', 'list'] failed with exit code 1: No PulseAudio daemon running, or not running as session daemon. RelatedPackageVersions: linux-restricted-modules-3.19.0-16-generic N/A linux-backports-modules-3.19.0-16-generic N/A linux-firmware 1.143 RfKill: SourcePackage: linux UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev' UpgradeStatus: No upgrade log present (probably fresh install) dmi.bios.date: 01/06/2014 dmi.bios.vendor: American Megatrends Inc. dmi.bios.version: F18i dmi.board.asset.tag: To be filled by O.E.M. dmi.board.name: Z77X-D3H dmi.board.vendor: Gigabyte Technology Co., Ltd. dmi.board.version: x.x dmi.chassis.asset.tag: To Be Filled By O.E.M. dmi.chassis.type: 3 dmi.chassis.vendor: Gigabyte Technology Co., Ltd. dmi.chassis.version: To Be Filled By O.E.M. dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvrF18i:bd01/06/2014:svnGigabyteTechnologyCo.,Ltd.:pnTobefilledbyO.E.M.:pvrTobefilledbyO.E.M.:rvnGigabyteTechnologyCo.,Ltd.:rnZ77X-D3H:rvrx.x:cvnGigabyteTechnologyCo.,Ltd.:ct3:cvrToBeFilledByO.E.M.: dmi.product.name: To be filled by O.E.M. dmi.product.version: To be filled by O.E.M. dmi.sys.vendor: Gigabyte Technology Co., Ltd. --- ApportVersion: 2.17.2-0ubuntu1 Architecture: amd64 DistroRelease: Ubuntu 15.04 InstallationDate: Installed on 2015-05-10 (5 days ago) InstallationMedia: Ubuntu-Server 15.04 "Vivid Vervet" - Release amd64 (20150422) Package: linux (not installed) ProcEnviron: TERM=xterm-256color PATH=(custom, no user) LANG=en_US.UTF-8 SHELL=/bin/bash Tags: vivid Uname: Linux 4.1.0-040100rc3-generic x86_64 UnreportableReason: The running kernel is not an Ubuntu kernel UpgradeStatus: No upgrade log present (probably fresh install) UserGroups: _MarkForUpload: True To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1454903/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
