ReadOnly: Add processing for ReadOnly delegation requests and revoke requests to the processing loop for CALL packets we receive from different nodes.

This implements the ReadOnly and ReadWrite request processing, delegation and revoking of delegations for all requests coming in across the network from a remote node.

(This used to be ctdb commit 78f2c2ea70e6270cec59db7c3f174a511bf608a9)

1 files changed, 116 insertions, 14 deletions

diff --git a/ctdb/server/ctdb_call.c b/ctdb/server/ctdb_call.c
index 7d1dd56c6d..2df86b46c9 100644
--- a/ctdb/server/ctdb_call.c
+++ b/ctdb/server/ctdb_call.c
@@ -43,7 +43,6 @@
 	return ctdb_db;
 }
 
-
 /*
   a varient of input packet that can be used in lock requeue
 */
@@ -489,6 +488,8 @@ void ctdb_request_call(struct ctdb_context *ctdb, struct ctdb_req_header *hdr)
 	call->key.dsize = c->keylen;
 	call->call_data.dptr = c->data + c->keylen;
 	call->call_data.dsize = c->calldatalen;
+	call->reply_data.dptr  = NULL;
+	call->reply_data.dsize = 0;
 
 	/* determine if we are the dmaster for this key. This also
 	   fetches the record data (if any), thus avoiding a 2nd fetch of the data 
@@ -505,9 +506,36 @@ void ctdb_request_call(struct ctdb_context *ctdb, struct ctdb_req_header *hdr)
 		return;
 	}
 
-	/* if we are not the dmaster, then send a redirect to the
-	   requesting node */
-	if (header.dmaster != ctdb->pnn) {
+	/* Dont do READONLY if we dont have a tracking database */
+	if ((c->flags & CTDB_WANT_READONLY) && ctdb_db->rottdb == NULL) {
+		c->flags &= ~CTDB_WANT_READONLY;
+	}
+
+	if (header.flags & CTDB_REC_RO_REVOKE_COMPLETE) {
+		header.flags &= ~(CTDB_REC_RO_HAVE_DELEGATIONS|CTDB_REC_RO_HAVE_READONLY|CTDB_REC_RO_REVOKING_READONLY|CTDB_REC_RO_REVOKE_COMPLETE);
+		if (ctdb_ltdb_store(ctdb_db, call->key, &header, data) != 0) {
+			ctdb_fatal(ctdb, "Failed to write header with cleared REVOKE flag");
+		}
+	}
+
+	/* if we are revoking, we must defer all other calls until the revoke
+	 * had completed.
+	 */
+	if (header.flags & CTDB_REC_RO_REVOKING_READONLY) {
+		talloc_free(data.dptr);
+		ret = ctdb_ltdb_unlock(ctdb_db, call->key);
+
+		if (ctdb_add_revoke_deferred_call(ctdb, ctdb_db, call->key, hdr, ctdb_call_input_pkt, ctdb) != 0) {
+			ctdb_fatal(ctdb, "Failed to add deferred call for revoke child");
+		}
+		talloc_free(call);
+		return;
+	}
+
+	/* if we are not the dmaster and are not hosting any delegations,
+	   then send a redirect to the requesting node */
+	if ((header.dmaster != ctdb->pnn) 
+	    && (!(header.flags & CTDB_REC_RO_HAVE_DELEGATIONS)) ) {
 		talloc_free(data.dptr);
 		ctdb_call_send_redirect(ctdb, call->key, c, &header);
 
@@ -518,6 +546,80 @@ void ctdb_request_call(struct ctdb_context *ctdb, struct ctdb_req_header *hdr)
 		return;
 	}
 
+	if ( (!(c->flags & CTDB_WANT_READONLY))
+	&& (header.flags & (CTDB_REC_RO_HAVE_DELEGATIONS|CTDB_REC_RO_HAVE_READONLY)) ) {
+		header.flags   |= CTDB_REC_RO_REVOKING_READONLY;
+		if (ctdb_ltdb_store(ctdb_db, call->key, &header, data) != 0) {
+			ctdb_fatal(ctdb, "Failed to store record with HAVE_DELEGATIONS set");
+		}
+		ret = ctdb_ltdb_unlock(ctdb_db, call->key);
+
+		if (ctdb_start_revoke_ro_record(ctdb, ctdb_db, call->key, &header, data) != 0) {
+			ctdb_fatal(ctdb, "Failed to start record revoke");
+		}
+		talloc_free(data.dptr);
+
+		if (ctdb_add_revoke_deferred_call(ctdb, ctdb_db, call->key, hdr, ctdb_call_input_pkt, ctdb) != 0) {
+			ctdb_fatal(ctdb, "Failed to add deferred call for revoke child");
+		}
+		talloc_free(call);
+
+		return;
+	}		
+
+	/* If this is the first request for delegation. bump rsn and set
+	 * the delegations flag
+	 */
+	if ((c->flags & CTDB_WANT_READONLY)
+	&&  (c->callid == CTDB_FETCH_WITH_HEADER_FUNC)
+	&&  (!(header.flags & CTDB_REC_RO_HAVE_DELEGATIONS))) {
+		header.rsn     += 3;
+		header.flags   |= CTDB_REC_RO_HAVE_DELEGATIONS;
+		if (ctdb_ltdb_store(ctdb_db, call->key, &header, data) != 0) {
+			ctdb_fatal(ctdb, "Failed to store record with HAVE_DELEGATIONS set");
+		}
+	}
+	if ((c->flags & CTDB_WANT_READONLY) 
+	&&  (call->call_id == CTDB_FETCH_WITH_HEADER_FUNC)) {
+		TDB_DATA tdata;
+
+		tdata = tdb_fetch(ctdb_db->rottdb, call->key);
+		if (ctdb_trackingdb_add_pnn(ctdb, &tdata, c->hdr.srcnode) != 0) {
+			ctdb_fatal(ctdb, "Failed to add node to trackingdb");
+		}
+		if (tdb_store(ctdb_db->rottdb, call->key, tdata, TDB_REPLACE) != 0) {
+			ctdb_fatal(ctdb, "Failed to store trackingdb data");
+		}
+		free(tdata.dptr);
+
+		ret = ctdb_ltdb_unlock(ctdb_db, call->key);
+		if (ret != 0) {
+			DEBUG(DEBUG_ERR,(__location__ " ctdb_ltdb_unlock() failed with error %d\n", ret));
+		}
+
+		len = offsetof(struct ctdb_reply_call, data) + data.dsize + sizeof(struct ctdb_ltdb_header);
+		r = ctdb_transport_allocate(ctdb, ctdb, CTDB_REPLY_CALL, len, 
+					    struct ctdb_reply_call);
+		CTDB_NO_MEMORY_FATAL(ctdb, r);
+		r->hdr.destnode  = c->hdr.srcnode;
+		r->hdr.reqid     = c->hdr.reqid;
+		r->status        = 0;
+		r->datalen       = data.dsize + sizeof(struct ctdb_ltdb_header);
+		header.rsn      -= 2;
+		header.flags   |= CTDB_REC_RO_HAVE_READONLY;
+		header.flags   &= ~CTDB_REC_RO_HAVE_DELEGATIONS;
+		memcpy(&r->data[0], &header, sizeof(struct ctdb_ltdb_header));
+
+		if (data.dsize) {
+			memcpy(&r->data[sizeof(struct ctdb_ltdb_header)], data.dptr, data.dsize);
+		}
+
+		ctdb_queue_packet(ctdb, &r->hdr);
+
+		talloc_free(r);
+		return;
+	}
+
 	CTDB_UPDATE_STAT(ctdb, max_hop_count, c->hopcount);
 
 	/* Try if possible to migrate the record off to the caller node.
@@ -922,8 +1024,8 @@ struct revokechild_requeue_handle {
 	void *ctx;
 };
 
-static void deferred_call_requeue(struct event_context *ev, struct timed_event *te,
-		      struct timeval t, void *private_data)
+static void deferred_call_requeue(struct event_context *ev, struct timed_event *te, 
+		       struct timeval t, void *private_data)
 {
 	struct revokechild_requeue_handle *requeue_handle = talloc_get_type(private_data, struct revokechild_requeue_handle);
 
@@ -968,10 +1070,10 @@ static int revokechild_destructor(struct revokechild_handle *rc)
 	return 0;
 }
 
-static void revokechild_handler(struct event_context *ev, struct fd_event *fde,
-		     uint16_t flags, void *private_data)
+static void revokechild_handler(struct event_context *ev, struct fd_event *fde, 
+			     uint16_t flags, void *private_data)
 {
-	struct revokechild_handle *rc = talloc_get_type(private_data,
+	struct revokechild_handle *rc = talloc_get_type(private_data, 
 						     struct revokechild_handle);
 	int ret;
 	char c;
@@ -1015,8 +1117,8 @@ static void update_record_cb(struct ctdb_client_control_state *state)
 	revoke_state = state->async.private_data;
 
 	state->async.fn = NULL;
-	 ret = ctdb_control_recv(state->ctdb, state, state, NULL, &res, NULL);
-	 if ((ret != 0) || (res != 0)) {
+        ret = ctdb_control_recv(state->ctdb, state, state, NULL, &res, NULL);
+        if ((ret != 0) || (res != 0)) {
 		DEBUG(DEBUG_ERR,("Recv for revoke update record failed ret:%d res:%d\n", ret, res));
 		revoke_state->status = -1;
 	}
@@ -1045,8 +1147,8 @@ static void revoke_send_cb(struct ctdb_context *ctdb, uint32_t pnn, void *privat
 
 }
 
-static void ctdb_revoke_timeout_handler(struct event_context *ev, struct timed_event *te,
-			     struct timeval yt, void *private_data)
+static void ctdb_revoke_timeout_handler(struct event_context *ev, struct timed_event *te, 
+			      struct timeval yt, void *private_data)
 {
 	struct ctdb_revoke_state *state = private_data;
 
@@ -1064,7 +1166,7 @@ static int ctdb_revoke_all_delegations(struct ctdb_context *ctdb, struct ctdb_db
 	state->key     = key;
 	state->header  = header;
 	state->data    = data;
-
+ 
 	ctdb_trackingdb_traverse(ctdb, tdata, revoke_send_cb, state);
 
 	event_add_timed(ctdb->ev, state, timeval_current_ofs(5, 0), ctdb_revoke_timeout_handler, state);