On Thu, Sep 07, 2017 at 09:46:17AM +1000, Dave Chinner wrote: > On Wed, Sep 06, 2017 at 04:03:37PM -0400, Dave Jones wrote: > > On Mon, Aug 28, 2017 at 09:25:42PM -0700, Darrick J. Wong wrote: > > > On Mon, Aug 28, 2017 at 04:31:30PM -0400, Dave Jones wrote: > > > > I'm still trying to narrow down an exact reproducer, but it seems having > > > > trinity do a combination of sendfile & writev, with pipes and regular > > > > files as fd's is the best repro. > > > > > > > > Is this a real problem, or am I chasing ghosts ? That it doesn't happen > > > > on ext4 or btrfs is making me wonder... > > > > > > <shrug> I haven't heard of any problems w/ directio xfs lately, but OTOH > > > I think it's the only filesystem that uses iomap_dio_rw, which would > > > explain why ext4/btrfs don't have this problem. > > > > Another warning, from likely the same root cause. > > > > WARNING: CPU: 3 PID: 572 at lib/iov_iter.c:962 iov_iter_pipe+0xe2/0xf0 > > WARN_ON(pipe->nrbufs == pipe->buffers); > > * @nrbufs: the number of non-empty pipe buffers in this pipe > * @buffers: total number of buffers (should be a power of 2) > > So that's warning that the pipe buffer is already full before we > try to read from the filesystem? > > That doesn't seem like an XFS problem - it indicates the pipe we are > filling in generic_file_splice_read() is not being emptied by > whatever we are splicing the file data to.... The puzzling part is this runs for a day on ext4 or btrfs, whereas I can make xfs fall over pretty quickly. As Darrick pointed out though, this could be due to xfs being the only user of iomap_dio_rw. I'm juggling a few other things right now, so probably not going to have much time to dig further on this until after plumbers + 1 wk. Dave -- To unsubscribe from this list: send the line "unsubscribe linux-xfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
