Honour ldb:nosync properly

[Andrew Bartlett]

Attached are patches to make this work, both on metadata.tdb and from
python.  Mostly this isn't noticed as TDB_NO_FSYNC=1 is often set also.

CI pipeline:
https://gitlab.com/catalyst-samba/samba/pipelines/23095770

Please review and push.  This helps us measure LMDB performance against
TDB on a fair basis (as well as data imports). 

Thanks,

Andrew Bartlett

-- 
Andrew Bartlett                       http://samba.org/~abartlet/
Authentication Developer, Samba Team  http://samba.org
Samba Developer, Catalyst IT          http://catalyst.net.nz/services/samba
-------------- next part --------------
From 5fdb05e3732b00cd6f213e4d4f7a0648ece37195 Mon Sep 17 00:00:00 2001
From: Andrew Bartlett <abartlet at samba.org>
Date: Sun, 3 Jun 2018 18:35:15 +1200
Subject: [PATCH 1/2] pyldb-samba: Use the same smb.conf variable name as the C
 wrapper users for LDB_FLG_NOSYNC

This was never noticed as most wrappers on make test run with TDB_NO_FSYNC

However ldb_mdb has not been told to use this (naturally) and so we rely
on the smb.conf setting to not force an fsync().

BUG: https://bugzilla.samba.org/show_bug.cgi?id=13461

Signed-off-by: Andrew Bartlett <abartlet at samba.org>
---
 python/samba/__init__.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/python/samba/__init__.py b/python/samba/__init__.py
index 20c7db2bc6c..7b3c6538771 100644
--- a/python/samba/__init__.py
+++ b/python/samba/__init__.py
@@ -105,7 +105,7 @@ class Ldb(_Ldb):
 
         # Allow admins to force non-sync ldb for all databases
         if lp is not None:
-            nosync_p = lp.get("nosync", "ldb")
+            nosync_p = lp.get("ldb:nosync")
             if nosync_p is not None and nosync_p:
                 flags |= ldb.FLG_NOSYNC
 
-- 
2.14.3


From 8317779c466f0237f2f9342f69242060a7c9be86 Mon Sep 17 00:00:00 2001
From: Andrew Bartlett <abartlet at samba.org>
Date: Sun, 3 Jun 2018 18:36:47 +1200
Subject: [PATCH 2/2] dsdb: Honour LDB_FLG_NOSYNC for metadata.tdb

BUG: https://bugzilla.samba.org/show_bug.cgi?id=13462

Signed-off-by: Andrew Bartlett <abartlet at samba.org>
---
 source4/dsdb/samdb/ldb_modules/partition_metadata.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/source4/dsdb/samdb/ldb_modules/partition_metadata.c b/source4/dsdb/samdb/ldb_modules/partition_metadata.c
index d44947232ae..197e7b092e0 100644
--- a/source4/dsdb/samdb/ldb_modules/partition_metadata.c
+++ b/source4/dsdb/samdb/ldb_modules/partition_metadata.c
@@ -187,7 +187,7 @@ static int partition_metadata_open(struct ldb_module *module, bool create)
 	struct partition_private_data *data;
 	struct loadparm_context *lp_ctx;
 	char *filename, *dirname;
-	int open_flags;
+	int open_flags, tdb_flags, ldb_flags;
 	struct stat statbuf;
 
 	data = talloc_get_type_abort(ldb_module_get_private(module),
@@ -237,9 +237,17 @@ static int partition_metadata_open(struct ldb_module *module, bool create)
 	lp_ctx = talloc_get_type_abort(ldb_get_opaque(ldb, "loadparm"),
 				       struct loadparm_context);
 
+	tdb_flags = lpcfg_tdb_flags(lp_ctx, TDB_DEFAULT|TDB_SEQNUM);
+
+	ldb_flags = ldb_module_flags(ldb);
+
+	if (ldb_flags & LDB_FLG_NOSYNC) {
+		tdb_flags |= TDB_NOSYNC;
+	}
+
 	data->metadata->db = tdb_wrap_open(
 		data->metadata, filename, 10,
-		lpcfg_tdb_flags(lp_ctx, TDB_DEFAULT|TDB_SEQNUM), open_flags, 0660);
+		tdb_flags, open_flags, 0660);
 	if (data->metadata->db == NULL) {
 		talloc_free(tmp_ctx);
 		if (create) {
-- 
2.14.3