Re: 4.9.0 regression in pipe-backed iov_iter with systemd-nspawn

Al Viro
2017-01-13T11:25:35Z

On Fri, Jan 13, 2017 at 10:32:47AM +0000, Alan J. Wylie wrote:
> # dmesg | tail
> ...
> [ 141.553455] nr: 0->16, cur: 5->5, buffers: 16->16
> [ 141.553461] copied: 0, count:2147479552, idx:5, offs:0

OK, that looks like pipe_advance() fencepost (hopefully) dealt with in
the lib/iov_iter.c patch I've just posted. I'm going down right now, but
if you have a box you are not too fond of, it would be nice if you tried
that one. Warning: the patch had been written in a barely awake state, and
is completely untested. Treat accordingly...