[PATCH] Add missing async fsync_send()/recv() code to ceph VFS.

[David Disseldorp]

Hi Ralph and Jeremy,

On Sat, 28 Apr 2018 16:12:07 +0200, Ralph Böhme wrote:

> Hi Jeremy,
> 
> On Fri, Apr 27, 2018 at 04:07:43PM -0700, Jeremy Allison wrote:
> > Patch that implements fsync_send()/recv() by cheating
> > and using ceph_fsync() synchronously under the covers
> > attached.
...
> > +	PROFILE_TIMESTAMP(&start_time);
> > +
> > +	/* Make sync call. */
> > +	ret = ceph_fsync(handle->data, fsp->fh->fd, false);
> > +
> > +	if (ret != 0) {
> > +		/* ceph_fsync returns -errno on error. */
> > +		state->error = -ret;
> > +	}  
> 
> Shouldn't this be:
> 
>         if (tevent_req_error(req, ret)) {
>                 return tevent_req_post(req, ev);
>         }
> 
> ?

We still need to retain the errno negation, so that'd be
tevent_req_error(req, -ret)...
 
> > +
> > +	PROFILE_TIMESTAMP(&end_time);
> > +	state->duration = nsec_time_diff(&end_time, &start_time);
> > +
> > +	/* Mark it as done. */
> > +	tevent_req_done(req);
> > +	/* Return and schedule the completion of the call. */
> > +	return tevent_req_post(req, ev);
> > +}
> > +
> > +static int cephwrap_fsync_recv(struct tevent_req *req,
> > +				struct vfs_aio_state *vfs_aio_state)
> > +{
> > +	struct vfs_aio_state *state =
> > +		tevent_req_data(req, struct vfs_aio_state);
> > +
> > +	DBG_DEBUG("[CEPH] cephwrap_fsync_recv\n");
> > +
> > +	*vfs_aio_state = *state;
> > +	if (state->error != 0) {
> > +		return -1;
> > +	}  
> 
> Then this should be:
> 
>         if (tevent_req_is_unix_error(req, &vfs_aio_state->error)) {
>                 return -1;

This would mean that we don't propagate up the call duration on failure.
I'm not so familiar with the async VFS API, but is that to be expected?

Cheers, David