Long delays during journal transaction commit can cause blocked task warnings

Issue

System reports blocked tasks waiting for journal space:

INFO: task oracle:13070 blocked for more than 120 seconds.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
oracle        D ffffffff80157c4c     0 13070  12969 15092   13071 13069 (NOTLB)
 ffff8124e95fde88 0000000000000082 0000000000000000 ffffffff883c7f5b
 ffff8124e95fded8 0000000000000007 ffff8124ed7517a0 ffff8120f07447e0
 000077d22b830203 000000000000087d ffff8124ed751988 0000001800000246
Call Trace:
 [<ffffffff883c7f5b>] :ext4:__ext4_journal_stop+0x66/0x73
 [<ffffffff883a36e4>] :jbd2:jbd2_log_wait_commit+0xa3/0xf5
 [<ffffffff800a3bc2>] autoremove_wake_function+0x0/0x2e
 [<ffffffff883a3762>] :jbd2:__jbd2_log_start_commit+0x2c/0x34
 [<ffffffff883b8fbe>] :ext4:ext4_sync_file+0x166/0x1a8
 [<ffffffff800504a6>] do_fsync+0x52/0xa4
 [<ffffffff800e5326>] __do_fsync+0x23/0x36
 [<ffffffff8005d29e>] tracesys+0xd5/0xdf