dsdb: Remove use of schema USN in samldb_add_handle_msDS_IntId

This is not a frequent enough operation to warrent a cache, and the USN will be removed
from the schema code shortly

Signed-off-by: Andrew Bartlett <abartlet@samba.org>
Reviewed-by: Garming Sam <garming@catalyst.net.nz>

3 files changed, 21 insertions, 64 deletions

diff --git a/source4/dsdb/samdb/ldb_modules/repl_meta_data.c b/source4/dsdb/samdb/ldb_modules/repl_meta_data.c
index b551e34e1e3..0c94b2aa6b8 100644
--- a/source4/dsdb/samdb/ldb_modules/repl_meta_data.c
+++ b/source4/dsdb/samdb/ldb_modules/repl_meta_data.c
@@ -832,7 +832,6 @@ static int replmd_add_fix_la(struct ldb_module *module, struct ldb_message_eleme
  */
 static int replmd_add(struct ldb_module *module, struct ldb_request *req)
 {
-	struct samldb_msds_intid_persistant *msds_intid_struct;
 	struct ldb_context *ldb;
         struct ldb_control *control;
 	struct replmd_replicated_request *ac;
@@ -1149,14 +1148,6 @@ static int replmd_add(struct ldb_module *module, struct ldb_request *req)
 	if (control) {
 		control->critical = 0;
 	}
-	if (ldb_dn_compare_base(replmd_private->schema_dn, req->op.add.message->dn) != 0) {
-
-		/* Update the usn in the SAMLDB_MSDS_INTID_OPAQUE opaque */
-		msds_intid_struct = (struct samldb_msds_intid_persistant *) ldb_get_opaque(ldb, SAMLDB_MSDS_INTID_OPAQUE);
-		if (msds_intid_struct) {
-			msds_intid_struct->usn = ac->seq_num;
-		}
-	}
 	/* go on with the call chain */
 	return ldb_next_request(module, down_req);
 }
@@ -2519,7 +2510,6 @@ static int replmd_modify_handle_linked_attribs(struct ldb_module *module,
 
 static int replmd_modify(struct ldb_module *module, struct ldb_request *req)
 {
-	struct samldb_msds_intid_persistant *msds_intid_struct;
 	struct ldb_context *ldb;
 	struct replmd_replicated_request *ac;
 	struct ldb_request *down_req;
@@ -2674,14 +2664,6 @@ static int replmd_modify(struct ldb_module *module, struct ldb_request *req)
 		}
 	}
 
-	if (!ldb_dn_compare_base(replmd_private->schema_dn, msg->dn)) {
-		/* Update the usn in the SAMLDB_MSDS_INTID_OPAQUE opaque */
-		msds_intid_struct = (struct samldb_msds_intid_persistant *) ldb_get_opaque(ldb, SAMLDB_MSDS_INTID_OPAQUE);
-		if (msds_intid_struct) {
-			msds_intid_struct->usn = ac->seq_num;
-		}
-	}
-
 	/* go on with the call chain */
 	return ldb_next_request(module, down_req);
 }
diff --git a/source4/dsdb/samdb/ldb_modules/samldb.c b/source4/dsdb/samdb/ldb_modules/samldb.c
index 811262427fa..cc101a6ea4d 100644
--- a/source4/dsdb/samdb/ldb_modules/samldb.c
+++ b/source4/dsdb/samdb/ldb_modules/samldb.c
@@ -576,7 +576,6 @@ static int samldb_add_handle_msDS_IntId(struct samldb_ctx *ac)
 		msds_intid = generate_random() % 0X3FFFFFFF;
 		msds_intid += 0x80000000;
 		msds_intid_struct->msds_intid = msds_intid;
-		msds_intid_struct->usn = schema->loaded_usn;
 		DEBUG(2, ("No samldb_msds_intid_persistant struct, allocating a new one\n"));
 	} else {
 		msds_intid = msds_intid_struct->msds_intid;
@@ -584,22 +583,22 @@ static int samldb_add_handle_msDS_IntId(struct samldb_ctx *ac)
 
 	/* probe id values until unique one is found */
 	do {
-		uint64_t current_usn;
 		msds_intid++;
 		if (msds_intid > 0xBFFFFFFF) {
 			msds_intid = 0x80000001;
 		}
 		/*
-		 * Alternative strategy to a costly (even indexed search) to the
-		 * database.
-		 * We search in the schema if we have already this intid (using dsdb_attribute_by_attributeID_id because
-		 * in the range 0x80000000 0xBFFFFFFFF, attributeID is a DSDB_ATTID_TYPE_INTID).
+		 * We search in the schema if we have already this
+		 * intid (using dsdb_attribute_by_attributeID_id
+		 * because in the range 0x80000000 0xBFFFFFFFF,
+		 * attributeID is a DSDB_ATTID_TYPE_INTID).
+		 *
 		 * If so generate another random value.
-		 * If not check if the highest USN in the database for the schema partition is the
-		 * one that we know.
-		 * If so it means that's only this ldb context that is touching the schema in the database.
-		 * If not it means that's someone else has modified the database while we are doing our changes too
-		 * (this case should be very bery rare) in order to be sure do the search in the database.
+		 *
+		 * We have to check the DB in case someone else has
+		 * modified the database while we are doing our
+		 * changes too (this case should be very bery rare) in
+		 * order to be sure.
 		 */
 		if (dsdb_attribute_by_attributeID_id(schema, msds_intid)) {
 			msds_intid = generate_random() % 0X3FFFFFFF;
@@ -607,45 +606,22 @@ static int samldb_add_handle_msDS_IntId(struct samldb_ctx *ac)
 			continue;
 		}
 
-		ret = dsdb_module_load_partition_usn(ac->module, schema_dn,
-						     &current_usn, NULL, NULL);
+
+		ret = dsdb_module_search(ac->module, ac,
+					 &ldb_res,
+					 schema_dn, LDB_SCOPE_ONELEVEL, NULL,
+					 DSDB_FLAG_NEXT_MODULE,
+					 ac->req,
+					 "(msDS-IntId=%d)", msds_intid);
 		if (ret != LDB_SUCCESS) {
 			ldb_debug_set(ldb, LDB_DEBUG_ERROR,
-				      __location__": Searching for schema USN failed: %s\n",
+				      __location__": Searching for msDS-IntId=%d failed - %s\n",
+				      msds_intid,
 				      ldb_errstring(ldb));
 			return ldb_operr(ldb);
 		}
-
-		/* current_usn can be lesser than msds_intid_struct-> if there is
-		 * uncommited changes.
-		 */
-		if (current_usn > msds_intid_struct->usn) {
-			/* oups something has changed, someone/something
-			 * else is modifying or has modified the schema
-			 * we'd better check this intid is the database directly
-			 */
-
-			DEBUG(2, ("Schema has changed, searching the database for the unicity of %d\n",
-					msds_intid));
-
-			ret = dsdb_module_search(ac->module, ac,
-						&ldb_res,
-						schema_dn, LDB_SCOPE_ONELEVEL, NULL,
-						DSDB_FLAG_NEXT_MODULE,
-						ac->req,
-						"(msDS-IntId=%d)", msds_intid);
-			if (ret != LDB_SUCCESS) {
-				ldb_debug_set(ldb, LDB_DEBUG_ERROR,
-					__location__": Searching for msDS-IntId=%d failed - %s\n",
-					msds_intid,
-					ldb_errstring(ldb));
-				return ldb_operr(ldb);
-			}
-			id_exists = (ldb_res->count > 0);
-			talloc_free(ldb_res);
-		} else {
-			id_exists = 0;
-		}
+		id_exists = (ldb_res->count > 0);
+		talloc_free(ldb_res);
 
 	} while(id_exists);
 	msds_intid_struct->msds_intid = msds_intid;
diff --git a/source4/dsdb/samdb/samdb.h b/source4/dsdb/samdb/samdb.h
index 20a55fecb75..12971dd6d93 100644
--- a/source4/dsdb/samdb/samdb.h
+++ b/source4/dsdb/samdb/samdb.h
@@ -257,7 +257,6 @@ struct dsdb_openldap_dereference_result_control {
 
 struct samldb_msds_intid_persistant {
 	uint32_t msds_intid;
-	uint64_t usn;
 };
 
 #define SAMLDB_MSDS_INTID_OPAQUE "SAMLDB_MSDS_INTID_OPAQUE"