sync() hangs

[wsldankers]

Running 0.6.2-1precise on kernel 3.11.0-20-generic #34precise1-Ubuntu.

I ran into a situation (after several days of uptime) where every time I'd try to run ‘sync’ it would get stuck in an uninterruptible sleep state (‘D’ in ps aux).

/proc/<pid>/stack for such a process shows:

[<ffffffff811de00b>] sync_inodes_sb+0x9b/0xd0
[<ffffffff811e47cd>] sync_inodes_one_sb+0x1d/0x30
[<ffffffff811b8781>] iterate_supers+0x101/0x110
[<ffffffff811e4935>] sys_sync+0x35/0x90
[<ffffffff8175241d>] system_call_fastpath+0x1a/0x1f
[<ffffffffffffffff>] 0xffffffffffffffff

I have since rebooted the machine and everything is normal again, for now.

cheers,

[ryao]

This should be fixed in HEAD for the next release by 6f9548c.

[behlendorf]

Yup, this was already fixed in master so I'm going to close it out. But thanks for filing it.