From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Teigland Date: Thu, 13 Oct 2011 11:30:01 -0400 Subject: [Cluster-devel] cluster4 gfs_controld In-Reply-To: <1318516891.2719.30.camel@menhir> References: <20111013142059.GA6704@redhat.com> <1318516891.2719.30.camel@menhir> Message-ID: <20111013153001.GB6704@redhat.com> List-Id: To: cluster-devel.redhat.com MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit On Thu, Oct 13, 2011 at 03:41:31PM +0100, Steven Whitehouse wrote: > > cluster4 > > . jid from dlm-kernel "slots" which will be assigned similarly > What is the actual algorithm used to assign these slots? The same as picking jids: lowest unused id starting with 0. As for implementation, I'll add it to the current dlm recovery messages. (Frankly, I'd really like to just set jid to nodeid-1. Any support for that? It would obviously add a slight requirement to picking nodeid's, which 99.9% of people already do.) > > . first mounter using a dlm lock in lock_dlm > > > That sounds good to me. The thing we need to resolve is how do we get > from one to the other. We may have to introduce a new name for the lock > protocol to avoid people accidentally using both schemes in the same > cluster. Compatibility rests on the fact that the new dlm kernel features will only work when the cluster4 dlm_controld is used. dlm_controld.v3 running: dlm_recover_register() returns an error, and everything falls back to working as it does now, with gfs_controld.v3 etc. dlm_controld.v4 running: dlm_recover_register() works, lock_dlm sets jid and first. (gfs_controld.v3 will fail to even run with dlm_controld.v4, and other combinations of v3/v4 daemons will also fail to run together.) > > cluster4 > > . coordination of dlm-kernel/gfs-kernel recovery is done > > directly in kernel using callbacks from dlm-kernel to gfs-kernel. > > . gdlm_mount(struct gfs2_sbd *sdp, const char *table, int *first, int *jid) > > calls dlm_recover_register(dlm, &jid, &recover_callbacks) > Can we not just pass the extra functions to dlm_create_lockspace? That > seems a bit simpler than adding an extra function just to register the > callbacks, Yes we could; I may do that. Returning the error mentioned above becomes less direct. I'd have to overload the jid arg, or add another to indicate the callbacks are enabled.