Ceph » rbd

qemu-kvm VM with rbd backed storage works until guest tries to write data, then kernel_hung task messages appear.

INFO: task yum:1582 blocked for more than 120 seconds.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
yum D 0000000000000000 0 1582 1566 0x00000080
ffff88007ae3bcc8 0000000000000082 000000017ae3bc28 ffff88003755ae68
ffff88003755ae68 ffff88003755ae68 0000000000000cc1 0000000000000005
ffff88007ae27058 ffff88007ae3bfd8 000000000000fb88 ffff88007ae27058
Call Trace:
[<ffffffff8125e808>] ? blk_queue_bio+0x168/0x5a0
[<ffffffff8150e7d5>] schedule_timeout+0x215/0x2e0
[<ffffffff8125cdde>] ? generic_make_request+0x25e/0x530
[<ffffffff8111c575>] ? mempool_alloc_slab+0x15/0x20
[<ffffffff8150e453>] wait_for_common+0x123/0x180
[<ffffffff81063310>] ? default_wake_function+0x0/0x20
[<ffffffff8125d13d>] ? submit_bio+0x8d/0x120
[<ffffffff8150e56d>] wait_for_completion+0x1d/0x20
[<ffffffff812607bd>] __blkdev_issue_flush+0xad/0xe0
[<ffffffff81260806>] blkdev_issue_flush+0x16/0x20
[<ffffffffa008c2c1>] ext4_sync_file+0x191/0x260 [ext4]
[<ffffffff811b1b11>] vfs_fsync_range+0xa1/0xe0
[<ffffffff811b1bbd>] vfs_fsync+0x1d/0x20
[<ffffffff811b1bfe>] do_fsync+0x3e/0x60
[<ffffffff811b1c33>] sys_fdatasync+0x13/0x20
[<ffffffff8100b072>] system_call_fastpath+0x16/0x1b
INFO: task jbd2/dm18:376 blocked for more than 120 seconds.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
jbd2/dm18 D 0000000000000000 0 376 2 0x00000000
ffff880037617c20 0000000000000046 ffff880000000000 0000004611119ae4
ffff880037617b90 ffff880037401750 0000000000011374 ffffffffae07f155
ffff88003757e638 ffff880037617fd8 000000000000fb88 ffff88003757e638
Call Trace:
[<ffffffff810a1ac9>] ? ktime_get_ts+0xa9/0xe0
[<ffffffff811b6040>] ? sync_buffer+0x0/0x50
[<ffffffff8150e0f3>] io_schedule+0x73/0xc0
[<ffffffff811b6080>] sync_buffer+0x40/0x50
[<ffffffff8150eaaf>] __wait_on_bit+0x5f/0x90
[<ffffffff811b6040>] ? sync_buffer+0x0/0x50
[<ffffffff8150eb58>] out_of_line_wait_on_bit+0x78/0x90
[<ffffffff81096ce0>] ? wake_bit_function+0x0/0x50
[<ffffffff811b6036>] __wait_on_buffer+0x26/0x30
[<ffffffffa0065761>] jbd2_journal_commit_transaction+0x1131/0x14b0 [jbd2]
[<ffffffff810096f0>] ? __switch_to+0xd0/0x320
[<ffffffff81081a5b>] ? try_to_del_timer_sync+0x7b/0xe0
[<ffffffffa006af38>] kjournald2+0xb8/0x220 [jbd2]
[<ffffffff81096ca0>] ? autoremove_wake_function+0x0/0x40
[<ffffffffa006ae80>] ? kjournald2+0x0/0x220 [jbd2]
[<ffffffff81096936>] kthread+0x96/0xa0
[<ffffffff8100c0ca>] child_rip+0xa/0x20
[<ffffffff810968a0>] ? kthread+0x0/0xa0
[<ffffffff8100c0c0>] ? child_rip+0x0/0x20

kvm config as well as full vm log and rbd debug are attached