From: Andrew Tridgell <tridge@samba.org>
Date: Mon, 18 Dec 2006 03:05:49 +0000 (+1100)
Subject: next step towards dmaster/lmaster code
X-Git-Tag: tevent-0.9.20~348^2~2999
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=abf3b910be64613a1b40522287b5ccb68ea75852;p=thirdparty%2Fsamba.git

next step towards dmaster/lmaster code
(This used to be ctdb commit 95e7be8d1aaafafb574c406fe778093606a28be8)
---

diff --git a/ctdb/common/ctdb_call.c b/ctdb/common/ctdb_call.c
index 441e22b613c..74d97ee5994 100644
--- a/ctdb/common/ctdb_call.c
+++ b/ctdb/common/ctdb_call.c
@@ -28,25 +28,20 @@
 /*
   local version of ctdb_call
 */
-static int ctdb_call_local(struct ctdb_context *ctdb, TDB_DATA key, int call_id, 
-			   TDB_DATA *call_data, TDB_DATA *reply_data)
+static int ctdb_call_local(struct ctdb_context *ctdb, TDB_DATA key, 
+			   struct ctdb_ltdb_header *header, TDB_DATA *data,
+			   int call_id, TDB_DATA *call_data, TDB_DATA *reply_data)
 {
 	struct ctdb_call *c;
 	struct ctdb_registered_call *fn;
-	TDB_DATA data;
-	struct ctdb_ltdb_header header;
-	int ret;
 
 	c = talloc(ctdb, struct ctdb_call);
 	CTDB_NO_MEMORY(ctdb, c);
 
-	ret = ctdb_ltdb_fetch(ctdb, c, key, &header, &data);
-	if (ret != 0) return -1;
-	
 	c->key = key;
 	c->call_data = call_data;
-	c->record_data.dptr = talloc_memdup(c, data.dptr, data.dsize);
-	c->record_data.dsize = data.dsize;
+	c->record_data.dptr = talloc_memdup(c, data->dptr, data->dsize);
+	c->record_data.dsize = data->dsize;
 	CTDB_NO_MEMORY(ctdb, c->record_data.dptr);
 	c->new_data = NULL;
 	c->reply_data = NULL;
@@ -65,7 +60,7 @@ static int ctdb_call_local(struct ctdb_context *ctdb, TDB_DATA key, int call_id,
 	}
 
 	if (c->new_data) {
-		if (ctdb_ltdb_store(ctdb, key, &header, *c->new_data) != 0) {
+		if (ctdb_ltdb_store(ctdb, key, header, *c->new_data) != 0) {
 			ctdb_set_error(ctdb, "ctdb_call tdb_store failed\n");
 			return -1;
 		}
@@ -86,22 +81,60 @@ static int ctdb_call_local(struct ctdb_context *ctdb, TDB_DATA key, int call_id,
 	return 0;
 }
 
+/*
+  send an error reply
+*/
+static void ctdb_send_error(struct ctdb_context *ctdb, 
+			    struct ctdb_req_header *hdr, int ecode)
+{
+	printf("ctdb_send_error not implemented\n");
+}
+
+/*
+  send a redirect reply
+*/
+static void ctdb_call_send_redirect(struct ctdb_context *ctdb, 
+				    struct ctdb_req_call *c, 
+				    struct ctdb_ltdb_header *header)
+{
+	printf("ctdb_call_send_redirect not implemented\n");
+}
+
 /*
   called when a CTDB_REQ_CALL packet comes in
 */
 void ctdb_request_call(struct ctdb_context *ctdb, struct ctdb_req_header *hdr)
 {
 	struct ctdb_req_call *c = (struct ctdb_req_call *)hdr;
-	TDB_DATA key, call_data, reply_data;
+	TDB_DATA key, data, call_data, reply_data;
 	struct ctdb_reply_call *r;
 	struct ctdb_node *node;
+	int ret;
+	struct ctdb_ltdb_header header;
 
 	key.dptr = c->data;
 	key.dsize = c->keylen;
 	call_data.dptr = c->data + c->keylen;
 	call_data.dsize = c->calldatalen;
 
-	ctdb_call_local(ctdb, key, c->callid, 
+	/* 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 
+	   if the call will be answered locally */
+	ret = ctdb_ltdb_fetch(ctdb, key, &header, &data);
+	if (ret != 0) {
+		ctdb_send_error(ctdb, hdr, ret);
+		return;
+	}
+
+	/* if we are not the dmaster, then send a redirect to the
+	   requesting node */
+	if (header.dmaster != ctdb->vnn) {
+		ctdb_call_send_redirect(ctdb, c, &header);
+		talloc_free(data.dptr);
+		return;
+	}
+
+	ctdb_call_local(ctdb, key, &header, &data, c->callid, 
 			call_data.dsize?&call_data:NULL,
 			&reply_data);
 
@@ -181,7 +214,9 @@ void ctdb_call_timeout(struct event_context *ev, struct timed_event *te,
 */
 struct ctdb_call_state *ctdb_call_local_send(struct ctdb_context *ctdb, 
 					     TDB_DATA key, int call_id, 
-					     TDB_DATA *call_data, TDB_DATA *reply_data)
+					     TDB_DATA *call_data, TDB_DATA *reply_data,
+					     struct ctdb_ltdb_header *header,
+					     TDB_DATA *data)
 {
 	struct ctdb_call_state *state;
 	int ret;
@@ -192,7 +227,8 @@ struct ctdb_call_state *ctdb_call_local_send(struct ctdb_context *ctdb,
 	state->state = CTDB_CALL_DONE;
 	state->node = ctdb->nodes[ctdb->vnn];
 
-	ret = ctdb_call_local(ctdb, key, call_id, call_data, &state->reply_data);
+	ret = ctdb_call_local(ctdb, key, header, data, 
+			      call_id, call_data, &state->reply_data);
 	return state;
 }
 
@@ -204,13 +240,24 @@ struct ctdb_call_state *ctdb_call_send(struct ctdb_context *ctdb,
 				       TDB_DATA key, int call_id, 
 				       TDB_DATA *call_data, TDB_DATA *reply_data)
 {
-	uint32_t dest;
 	uint32_t len;
 	struct ctdb_call_state *state;
+	int ret;
+	struct ctdb_ltdb_header header;
+	TDB_DATA data;
 
-	dest = ctdb_hash(&key) % ctdb->num_nodes;
-	if (dest == ctdb->vnn && !(ctdb->flags & CTDB_FLAG_SELF_CONNECT)) {
-		return ctdb_call_local_send(ctdb, key, call_id, call_data, reply_data);
+	/*
+	  if we are the dmaster for this key then we don't need to
+	  send it off at all, we can bypass the network and handle it
+	  locally. To find out if we are the dmaster we need to look
+	  in our ltdb
+	*/
+	ret = ctdb_ltdb_fetch(ctdb, key, &header, &data);
+	if (ret != 0) return NULL;
+
+	if (header.dmaster == ctdb->vnn && !(ctdb->flags & CTDB_FLAG_SELF_CONNECT)) {
+		return ctdb_call_local_send(ctdb, key, call_id, call_data, reply_data,
+					    &header, &data);
 	}
 
 	state = talloc_zero(ctdb, struct ctdb_call_state);
@@ -222,7 +269,7 @@ struct ctdb_call_state *ctdb_call_send(struct ctdb_context *ctdb,
 
 	state->c->hdr.length    = len;
 	state->c->hdr.operation = CTDB_REQ_CALL;
-	state->c->hdr.destnode  = dest;
+	state->c->hdr.destnode  = header.dmaster;
 	state->c->hdr.srcnode   = ctdb->vnn;
 	/* this limits us to 16k outstanding messages - not unreasonable */
 	state->c->hdr.reqid     = idr_get_new(ctdb->idr, state, 0xFFFF);
@@ -234,7 +281,7 @@ struct ctdb_call_state *ctdb_call_send(struct ctdb_context *ctdb,
 		memcpy(&state->c->data[key.dsize], call_data->dptr, call_data->dsize);
 	}
 
-	state->node = ctdb->nodes[dest];
+	state->node = ctdb->nodes[header.dmaster];
 	state->state = CTDB_CALL_WAIT;
 
 	talloc_set_destructor(state, ctdb_call_destructor);
diff --git a/ctdb/common/ctdb_ltdb.c b/ctdb/common/ctdb_ltdb.c
index 004ab254d5d..821aad5ee59 100644
--- a/ctdb/common/ctdb_ltdb.c
+++ b/ctdb/common/ctdb_ltdb.c
@@ -50,6 +50,7 @@ static void ltdb_initial_header(struct ctdb_context *ctdb,
 				struct ctdb_ltdb_header *header)
 {
 	header->rsn = 0;
+	/* initial dmaster is the lmaster */
 	header->dmaster = ctdb_hash(&key) % ctdb->num_nodes;
 	header->laccessor = header->dmaster;
 	header->lacount = 0;
@@ -61,7 +62,7 @@ static void ltdb_initial_header(struct ctdb_context *ctdb,
   and returning the body of the record. A valid (initial) header is
   returned if the record is not present
 */
-int ctdb_ltdb_fetch(struct ctdb_context *ctdb, TALLOC_CTX *mem_ctx,
+int ctdb_ltdb_fetch(struct ctdb_context *ctdb, 
 		    TDB_DATA key, struct ctdb_ltdb_header *header, TDB_DATA *data)
 {
 	TDB_DATA rec;
@@ -78,7 +79,7 @@ int ctdb_ltdb_fetch(struct ctdb_context *ctdb, TALLOC_CTX *mem_ctx,
 	*header = *(struct ctdb_ltdb_header *)rec.dptr;
 
 	data->dsize = rec.dsize - sizeof(struct ctdb_ltdb_header);
-	data->dptr = talloc_memdup(mem_ctx, sizeof(struct ctdb_ltdb_header)+rec.dptr,
+	data->dptr = talloc_memdup(ctdb, sizeof(struct ctdb_ltdb_header)+rec.dptr,
 				   data->dsize);
 	CTDB_NO_MEMORY(ctdb, data->dptr);
 
diff --git a/ctdb/include/ctdb_private.h b/ctdb/include/ctdb_private.h
index bbddd74b589..8675dccaddf 100644
--- a/ctdb/include/ctdb_private.h
+++ b/ctdb/include/ctdb_private.h
@@ -158,7 +158,7 @@ uint32_t ctdb_hash(TDB_DATA *key);
 void ctdb_request_call(struct ctdb_context *ctdb, struct ctdb_req_header *hdr);
 void ctdb_reply_call(struct ctdb_context *ctdb, struct ctdb_req_header *hdr);
 
-int ctdb_ltdb_fetch(struct ctdb_context *ctdb, TALLOC_CTX *mem_ctx,
+int ctdb_ltdb_fetch(struct ctdb_context *ctdb, 
 		    TDB_DATA key, struct ctdb_ltdb_header *header, TDB_DATA *data);
 int ctdb_ltdb_store(struct ctdb_context *ctdb, TDB_DATA key, 
 		    struct ctdb_ltdb_header *header, TDB_DATA data);
diff --git a/ctdb/tests/test1.sh b/ctdb/tests/test1.sh
index c91899fb380..26c6bc10027 100755
--- a/ctdb/tests/test1.sh
+++ b/ctdb/tests/test1.sh
@@ -1,5 +1,6 @@
 #!/bin/sh
 
-killall -q ctdb_test
+echo "Testing local send"
 bin/ctdb_test --nlist tests/1node.txt --listen 127.0.0.1:9001
-killall ctdb_test
+echo "Testing self connect"
+bin/ctdb_test --nlist tests/1node.txt --listen 127.0.0.1:9001 --self-connect