aio bug affecting 3.13 trusty kernel

[Sage Weil]

Hi,

We'rehitting an old aio bug in 3.13.0-100-generic, described by this 
thread

	http://www.gossamer-threads.com/lists/linux/kernel/1993181

reproduced by this

	http://www.kvack.org/~bcrl/20140824-aio_bug.c

and fixed by commit

	f8567a3845ac05bb28f3c1b478ef752762bd39ef

(although there may have been follow-on fixes; I didn't investigate 
further).

It's make Ceph lose aio completions on trusty kernels and hang.  Can the 
appropriate patch(es) be backported?

Thanks!
sage