task jbd2/dm-12-8:4462 blocked for more than 120 seconds

Issue

• Journal block device task was blocked for > 120 seconds and triggered the hung task watchdog to panic the system:

INFO: task jbd2/dm-12-8:4462 blocked for more than 120 seconds.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
jbd2/dm-12-8  D 0000000000000002     0  4462    585          4463  4407 (L-TLB)
 ffff811022879b90 0000000000000046 ffff81102f4a6800 ffff810693f5b9c0
 0000000000000286 000000000000000a ffff81102dd447e0 ffff810ee2781820
 003fa54ce2e9bc86 000000000000518a ffff81102dd449c8 0000000d38b962f8
Call Trace:
 [<ffffffff8006ec4e>] do_gettimeofday+0x40/0x90
 [<ffffffff8005a78d>] getnstimeofday+0x10/0x28
 [<ffffffff80028ae9>] sync_page+0x0/0x43
 [<ffffffff800637ca>] io_schedule+0x3f/0x67
 [<ffffffff80028b27>] sync_page+0x3e/0x43
 [<ffffffff8006390e>] __wait_on_bit_lock+0x36/0x66
 [<ffffffff8003fd9f>] __lock_page+0x5e/0x64
 [<ffffffff800a28e2>] wake_bit_function+0x0/0x23
 [<ffffffff80048015>] pagevec_lookup_tag+0x1a/0x21
 [<ffffffff8001d01d>] mpage_writepages+0x14f/0x37d
 [<ffffffff884f9252>] :ext4:ext4_writepage+0x0/0x334
 [<ffffffff884d9143>] :jbd2:jbd2_journal_commit_transaction+0x367/0x1068
 [<ffffffff8004b23a>] try_to_del_timer_sync+0x7f/0x88
 [<ffffffff884dcf7c>] :jbd2:kjournald2+0x9a/0x1ec
 [<ffffffff800a28b4>] autoremove_wake_function+0x0/0x2e
 [<ffffffff800a269c>] keventd_create_kthread+0x0/0xc4
 [<ffffffff884dcee2>] :jbd2:kjournald2+0x0/0x1ec
 [<ffffffff800a269c>] keventd_create_kthread+0x0/0xc4
 [<ffffffff80032974>] kthread+0xfe/0x132
 [<ffffffff8005dfb1>] child_rip+0xa/0x11
 [<ffffffff800a269c>] keventd_create_kthread+0x0/0xc4
 [<ffffffff80032876>] kthread+0x0/0x132
 [<ffffffff8005dfa7>] child_rip+0x0/0x11

Kernel panic - not syncing: hung_task: blocked tasks