s3:registry avoid updating keys which are going to be deleted in

reg_deletekey_recursive

this changes the complexity from O(n^2) to O(n) and reduces the time of
a 'net conf drop' with 10000 shares from 6min to 1.5s

Signed-off-by: Michael Adam <obnox@samba.org>

5 files changed, 46 insertions, 29 deletions

diff --git a/source3/registry/reg_api.c b/source3/registry/reg_api.c
index c66a95e406..289f77df76 100644
--- a/source3/registry/reg_api.c
+++ b/source3/registry/reg_api.c
@@ -606,41 +606,29 @@ WERROR reg_createkey(TALLOC_CTX *ctx, struct registry_key *parent,
 	return err;
 }
 
-WERROR reg_deletekey(struct registry_key *parent, const char *path)
+static WERROR reg_deletekey_internal(TALLOC_CTX *mem_ctx,
+				     struct registry_key *parent,
+				     const char *path, bool lazy)
 {
 	WERROR err;
 	char *name, *end;
-	struct registry_key *tmp_key, *key;
-	TALLOC_CTX *mem_ctx = talloc_stackframe();
-
+	struct registry_key *key;
 	name = talloc_strdup(mem_ctx, path);
 	if (name == NULL) {
 		err = WERR_NOMEM;
 		goto done;
 	}
 
-	/* check if the key has subkeys */
-	err = reg_openkey(mem_ctx, parent, name, REG_KEY_READ, &key);
-	W_ERROR_NOT_OK_GOTO_DONE(err);
-
-	err = fill_subkey_cache(key);
-	W_ERROR_NOT_OK_GOTO_DONE(err);
-
-	if (regsubkey_ctr_numkeys(key->subkeys) > 0) {
-		err = WERR_ACCESS_DENIED;
-		goto done;
-	}
-
 	/* no subkeys - proceed with delete */
 	end = strrchr(name, '\\');
 	if (end != NULL) {
 		*end = '\0';
 
 		err = reg_openkey(mem_ctx, parent, name,
-				  KEY_CREATE_SUB_KEY, &tmp_key);
+				  KEY_CREATE_SUB_KEY, &key);
 		W_ERROR_NOT_OK_GOTO_DONE(err);
 
-		parent = tmp_key;
+		parent = key;
 		name = end+1;
 	}
 
@@ -649,13 +637,36 @@ WERROR reg_deletekey(struct registry_key *parent, const char *path)
 		goto done;
 	}
 
-	err = delete_reg_subkey(parent->key, name);
+	err = delete_reg_subkey(parent->key, name, lazy);
+
+done:
+	return err;
+}
+
+WERROR reg_deletekey(struct registry_key *parent, const char *path)
+{
+	WERROR err;
+	struct registry_key *key;
+	TALLOC_CTX *mem_ctx = talloc_stackframe();
+
+	/* check if the key has subkeys */
+	err = reg_openkey(mem_ctx, parent, path, REG_KEY_READ, &key);
+	W_ERROR_NOT_OK_GOTO_DONE(err);
+
+	err = fill_subkey_cache(key);
+	W_ERROR_NOT_OK_GOTO_DONE(err);
 
+	if (regsubkey_ctr_numkeys(key->subkeys) > 0) {
+		err = WERR_ACCESS_DENIED;
+		goto done;
+	}
+	err = reg_deletekey_internal(mem_ctx, parent, path, false);
 done:
 	TALLOC_FREE(mem_ctx);
 	return err;
 }
 
+
 WERROR reg_setvalue(struct registry_key *key, const char *name,
 		    const struct registry_value *val)
 {
@@ -796,7 +807,7 @@ WERROR reg_deleteallvalues(struct registry_key *key)
  */
 static WERROR reg_deletekey_recursive_internal(struct registry_key *parent,
 					       const char *path,
-					       bool del_key)
+					       bool del_key, bool lazy)
 {
 	WERROR werr = WERR_OK;
 	struct registry_key *key;
@@ -819,13 +830,13 @@ static WERROR reg_deletekey_recursive_internal(struct registry_key *parent,
 	 */
 	for (i = regsubkey_ctr_numkeys(key->subkeys) ; i > 0; i--) {
 		subkey_name = regsubkey_ctr_specific_key(key->subkeys, i-1);
-		werr = reg_deletekey_recursive_internal(key, subkey_name, true);
+		werr = reg_deletekey_recursive_internal(key, subkey_name, true, del_key);
 		W_ERROR_NOT_OK_GOTO_DONE(werr);
 	}
 
 	if (del_key) {
 		/* now delete the actual key */
-		werr = reg_deletekey(parent, path);
+		werr = reg_deletekey_internal(mem_ctx, parent, path, lazy);
 	}
 
 done:
@@ -847,7 +858,7 @@ static WERROR reg_deletekey_recursive_trans(struct registry_key *parent,
 		return werr;
 	}
 
-	werr = reg_deletekey_recursive_internal(parent, path, del_key);
+	werr = reg_deletekey_recursive_internal(parent, path, del_key, false);
 
 	if (!W_ERROR_IS_OK(werr)) {
 		WERROR werr2;
diff --git a/source3/registry/reg_backend_db.c b/source3/registry/reg_backend_db.c
index 62d482069c..57d6d3980c 100644
--- a/source3/registry/reg_backend_db.c
+++ b/source3/registry/reg_backend_db.c
@@ -1287,6 +1287,7 @@ struct regdb_delete_subkey_context {
 	const char *key;
 	const char *subkey;
 	const char *path;
+	bool lazy;
 };
 
 static NTSTATUS regdb_delete_subkey_action(struct db_context *db,
@@ -1302,6 +1303,10 @@ static NTSTATUS regdb_delete_subkey_action(struct db_context *db,
 	werr = regdb_delete_key_lists(db, delete_ctx->path);
 	W_ERROR_NOT_OK_GOTO_DONE(werr);
 
+	if (delete_ctx->lazy) {
+		goto done;
+	}
+
 	werr = regsubkey_ctr_init(mem_ctx, &subkeys);
 	W_ERROR_NOT_OK_GOTO_DONE(werr);
 
@@ -1323,7 +1328,7 @@ done:
 	return werror_to_ntstatus(werr);
 }
 
-static WERROR regdb_delete_subkey(const char *key, const char *subkey)
+static WERROR regdb_delete_subkey(const char *key, const char *subkey, bool lazy)
 {
 	WERROR werr;
 	char *path;
@@ -1349,6 +1354,7 @@ static WERROR regdb_delete_subkey(const char *key, const char *subkey)
 	delete_ctx.key = key;
 	delete_ctx.subkey = subkey;
 	delete_ctx.path = path;
+	delete_ctx.lazy = lazy;
 
 	werr = ntstatus_to_werror(dbwrap_trans_do(regdb,
 						  regdb_delete_subkey_action,
diff --git a/source3/registry/reg_backend_smbconf.c b/source3/registry/reg_backend_smbconf.c
index 912f5eb1bf..11abb9cc66 100644
--- a/source3/registry/reg_backend_smbconf.c
+++ b/source3/registry/reg_backend_smbconf.c
@@ -42,9 +42,9 @@ static WERROR smbconf_create_subkey(const char *key, const char *subkey)
 	return regdb_ops.create_subkey(key, subkey);
 }
 
-static WERROR smbconf_delete_subkey(const char *key, const char *subkey)
+static WERROR smbconf_delete_subkey(const char *key, const char *subkey, bool lazy)
 {
-	return regdb_ops.delete_subkey(key, subkey);
+	return regdb_ops.delete_subkey(key, subkey, lazy);
 }
 
 static int smbconf_fetch_values(const char *key, struct regval_ctr *val)
diff --git a/source3/registry/reg_dispatcher.c b/source3/registry/reg_dispatcher.c
index a96047817d..5b52e98e08 100644
--- a/source3/registry/reg_dispatcher.c
+++ b/source3/registry/reg_dispatcher.c
@@ -113,10 +113,10 @@ WERROR create_reg_subkey(struct registry_key_handle *key, const char *subkey)
 	return WERR_NOT_SUPPORTED;
 }
 
-WERROR delete_reg_subkey(struct registry_key_handle *key, const char *subkey)
+WERROR delete_reg_subkey(struct registry_key_handle *key, const char *subkey, bool lazy)
 {
 	if (key->ops && key->ops->delete_subkey) {
-		return key->ops->delete_subkey(key->name, subkey);
+		return key->ops->delete_subkey(key->name, subkey, lazy);
 	}
 
 	return WERR_NOT_SUPPORTED;
diff --git a/source3/registry/reg_dispatcher.h b/source3/registry/reg_dispatcher.h
index c80ba15ec1..ec4474629c 100644
--- a/source3/registry/reg_dispatcher.h
+++ b/source3/registry/reg_dispatcher.h
@@ -25,7 +25,7 @@ bool store_reg_keys(struct registry_key_handle *key,
 		    struct regsubkey_ctr *subkeys);
 bool store_reg_values(struct registry_key_handle *key, struct regval_ctr *val);
 WERROR create_reg_subkey(struct registry_key_handle *key, const char *subkey);
-WERROR delete_reg_subkey(struct registry_key_handle *key, const char *subkey);
+WERROR delete_reg_subkey(struct registry_key_handle *key, const char *subkey, bool lazy);
 int fetch_reg_keys(struct registry_key_handle *key,
 		   struct regsubkey_ctr *subkey_ctr);
 int fetch_reg_values(struct registry_key_handle *key, struct regval_ctr *val);