----- Original Message ----- > From: "Mike Christie" <[email protected]> > To: "Douglas Fuller" <[email protected]>, [email protected] > Sent: Tuesday, June 16, 2015 10:58:07 AM > Subject: Re: [PATCH 4/6] osd_client, rbd: update event interface for > watch/notify2 > > On 06/12/2015 10:56 AM, Douglas Fuller wrote: > > +static void rbd_watch_error_cb(void *arg, u64 cookie, int err) > > +{ > > + struct rbd_device *rbd_dev = (struct rbd_device *)arg; > > + int ret; > > + > > + dout("%s: watch error %d on cookie %llu\n", rbd_dev->header_name, > > + err, cookie); > > + rbd_warn(rbd_dev, "%s: watch error %d on cookie %llu\n", > > + rbd_dev->header_name, err, cookie); > > + > > + /* reset watch */ > > + rbd_dev_refresh(rbd_dev); > > + rbd_dev_header_unwatch_sync(rbd_dev); > > + ret = rbd_dev_header_watch_sync(rbd_dev); > > + BUG_ON(ret); /* XXX: was the image deleted? can we be more graceful? */ > > Is this for debugging only? BUG()/BUG_ON() can kill the system. We > normally use it for cases where proceeding might cause something like > data corruption or where we want to catch programming bugs early on like > passing incorrect args to a function. > > The other caller if this function does not escalate like this function. > Are you sure you need to here? The code below will not run if we BUG > above, so if you did want to BUG, you would want to move the rbd_warn > before it.
Thanks for the catch; this case is probably worse than rbd_warn() and not as bad as BUG(). If the watch timed out or was disconnected and cannot be re-established, it's likely the rbd image has been deleted out from under this client. We should probably set the block device to a state where it just returns -EIO all the time at that point. I have logic for that in my earlier patchset; I'll duplicate it here. -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
