On Thu, 2022-08-25 at 06:56 -0400, Jeff Layton wrote:
> On Thu, 2022-08-25 at 10:32 +0200, Ilya Dryomov wrote:
> > On Wed, Aug 24, 2022 at 10:53 PM Jeff Layton <jlayton@xxxxxxxxxx> wrote:
> > >
> > > ceph_sync_write has assumed that a zero result in req->r_result means
> > > success. Testing with a recent cluster however shows the OSD returning
> > > a non-zero length written here. I'm not sure whether and when this
> > > changed, but fix the code to accept either result.
> > >
> > > Assume a negative result means error, and anything else is a success. If
> > > we're given a short length, then return a short write.
> > >
> > > Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx>
> > > ---
> > > fs/ceph/file.c | 10 +++++++++-
> > > 1 file changed, 9 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/fs/ceph/file.c b/fs/ceph/file.c
> > > index 86265713a743..c0b2c8968be9 100644
> > > --- a/fs/ceph/file.c
> > > +++ b/fs/ceph/file.c
> > > @@ -1632,11 +1632,19 @@ ceph_sync_write(struct kiocb *iocb, struct iov_iter *from, loff_t pos,
> > > req->r_end_latency, len, ret);
> > > out:
> > > ceph_osdc_put_request(req);
> > > - if (ret != 0) {
> > > + if (ret < 0) {
> > > ceph_set_error_write(ci);
> > > break;
> > > }
> > >
> > > + /*
> > > + * FIXME: it's unclear whether all OSD versions return the
> > > + * length written on a write. For now, assume that a 0 return
> > > + * means that everything got written.
> > > + */
> > > + if (ret && ret < len)
> > > + len = ret;
> > > +
> > > ceph_clear_error_write(ci);
> > > pos += len;
> > > written += len;
> > > --
> > > 2.37.2
> > >
> >
> > Hi Jeff,
> >
> > AFAIK OSDs aren't allowed to return any kind of length on a write
> > and there is no such thing as a short write. This definitely needs
> > deeper investigation.
> >
> > What is the cluster version you are testing against?
> >
>
> That's what I had thought too but I wasn't sure:
>
> [ceph: root@quad1 /]# ceph --version
> ceph version 17.0.0-14400-gf61b38dc (f61b38dc82e94f14e7a0a5f6a5888c0c78fafa6c) quincy (dev)
>
> I'll see if I can confirm that this is coming from the OSD and not some
> other layer as well.
My mistake. This bug turns out to be a different bug in the fscrypt
stack. We can drop this patch (and I probably should have sent it as an
RFC in the first place). Sorry for the noise!
--
Jeff Layton <jlayton@xxxxxxxxxx>
