On Thu, Aug 25, 2022 at 10:32:56AM +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?
OK, I'm only seeing 'ret' being set to the write length only when enabling
encryption (i.e. with test_dummy_encryption mount option). So, maybe the
right fix is something like:
diff --git a/fs/ceph/file.c b/fs/ceph/file.c
index 16dcade66923..5119d87d61fb 100644
--- a/fs/ceph/file.c
+++ b/fs/ceph/file.c
@@ -1889,6 +1889,7 @@ ceph_sync_write(struct kiocb *iocb, struct iov_iter *from, loff_t pos,
ceph_release_page_vector(pages, num_pages);
break;
}
+ ret = 0;
}
req = ceph_osdc_new_request(osdc, &ci->i_layout,
Cheers,
--
Luís
