On 14.01.19 г. 15:13 ч., Scott E. Blomquist wrote: > > Nikolay Borisov writes: > > > > On 14.01.19 г. 13:42 ч., Scott E. Blomquist wrote: > > > > <snip> > > > > > > The file system hung again below is the sysrq output > > > > > > Linux kanlabfs 4.19.13-custom #1 SMP Wed Jan 9 08:36:50 EST 2019 x86_64 x86_64 x86_64 GNU/Linux > > > > > > btrfs-progs v4.19.1 > > > > > > # btrfs fi df /export/ > > > Data, single: total=79.61TiB, used=79.61TiB > > > System, single: total=36.00MiB, used=8.31MiB > > > Metadata, single: total=192.01GiB, used=190.19GiB > > > GlobalReserve, single: total=512.00MiB, used=0.00B > > > > So this btrfs is hosted on your local machine but it is exported via > > NFS, correct? > > Correct and via samba also > > > > > > > # btrfs fi show > > > Label: '/export' uuid: 8f92c2e4-86fe-48cb-b2d3-bc36da765f02 > > > Total devices 3 FS bytes used 79.79TiB > > > devid 1 size 47.30TiB used 43.58TiB path /dev/sda1 > > > devid 2 size 21.83TiB used 18.11TiB path /dev/sdb1 > > > devid 3 size 21.83TiB used 18.11TiB path /dev/sdc1 > > > > What kind of disks are those, presumably spinning rust due to their size > > but what model/make? > > > > 3 x raid 6 on a LSI MegaRAID SAS 9271-8i > > > > [Mon Jan 14 06:24:26 2019] sysrq: SysRq : Show Blocked State > > > > <snip> > > > > > [Mon Jan 14 06:24:26 2019] btrfs-transacti D 0 6808 2 0x80000000 > > > [Mon Jan 14 06:24:26 2019] Call Trace: > > > [Mon Jan 14 06:24:26 2019] ? __schedule+0x2ea/0x870 > > > [Mon Jan 14 06:24:26 2019] schedule+0x32/0x80 > > > [Mon Jan 14 06:24:26 2019] btrfs_start_ordered_extent+0xca/0x100 [btrfs] > > > [Mon Jan 14 06:24:26 2019] ? wait_woken+0x80/0x80 > > > [Mon Jan 14 06:24:26 2019] btrfs_wait_ordered_range+0xbd/0x110 [btrfs] > > > [Mon Jan 14 06:24:26 2019] __btrfs_wait_cache_io+0x49/0x1a0 [btrfs] > > > [Mon Jan 14 06:24:26 2019] btrfs_write_dirty_block_groups+0xed/0x360 [btrfs] > > > [Mon Jan 14 06:24:26 2019] ? btrfs_run_delayed_refs+0x8b/0x1d0 [btrfs] > > > [Mon Jan 14 06:24:26 2019] commit_cowonly_roots+0x1ed/0x280 [btrfs] > > > [Mon Jan 14 06:24:26 2019] btrfs_commit_transaction+0x36e/0x8d0 [btrfs] > > > [Mon Jan 14 06:24:26 2019] ? start_transaction+0x9b/0x3f0 [btrfs] > > > [Mon Jan 14 06:24:26 2019] transaction_kthread+0x14d/0x180 [btrfs] > > > [Mon Jan 14 06:24:26 2019] kthread+0xf8/0x130 > > > [Mon Jan 14 06:24:26 2019] ? btrfs_cleanup_transaction+0x530/0x530 [btrfs] > > > [Mon Jan 14 06:24:26 2019] ? kthread_bind+0x10/0x10 > > > [Mon Jan 14 06:24:26 2019] ret_from_fork+0x35/0x40 > > > > So the transaction is being committed as a result of that > > btrfs_start_ordered_extent, which flushes data to disk. Since you've > > compiled your kernel can you run the following command from the kernel's > > source: > > > > ./scripts/faddr2line vmlinux btrfs_start_ordered_extent+0xca/0x100 > > > > 'vmlinux' should be the kernel executable with debug info that results > > from compiling the kernel. I want to figure out which line exactly > > btrfs_start_ordered_extent+0xca/0x100 resolves to. > > <snip> > > I'll have to rebuild the kernel with debug symbols. Do I have to be > booted into the kernel for that command to be useful? Actually I think you are hitting the issue fixed by the following patch: https://github.com/kdave/btrfs-devel/commit/db0d10b02620b83ee592f6fc023ae146d72c5f65 The patch went into 4.18, yet your initial report said the hang occurs on 4.17. Could you try running 4.19 with e73e81b6d011 ("btrfs: balance dirty metadata pages in btrfs_finish_ordered_io") reverted. > > Cheers and Thanks, > > sb. Scott Blomquist > > >
