s3: Make sure our CLEAR_IF_FIRST optimization works for messaging.tdb

In the child, we fully re-open messaging.tdb, which leads to one fcntl lock for
CLEAR_IF_FIRST detection per smbd. This opens the tdb in the parent and holds
it, so that tdb_reopen_all correctly catches the CLEAR_IF_FIRST bit.

3 files changed, 22 insertions, 0 deletions

diff --git a/source3/include/messages.h b/source3/include/messages.h
index 6063d358ea..865ffd4822 100644
--- a/source3/include/messages.h
+++ b/source3/include/messages.h
@@ -111,6 +111,8 @@ NTSTATUS messaging_tdb_init(struct messaging_context *msg_ctx,
 			    TALLOC_CTX *mem_ctx,
 			    struct messaging_backend **presult);
 
+bool messaging_tdb_parent_init(void);
+
 NTSTATUS messaging_ctdbd_init(struct messaging_context *msg_ctx,
 			      TALLOC_CTX *mem_ctx,
 			      struct messaging_backend **presult);
diff --git a/source3/lib/messages_local.c b/source3/lib/messages_local.c
index a58c7eb95f..b1712823a1 100644
--- a/source3/lib/messages_local.c
+++ b/source3/lib/messages_local.c
@@ -133,6 +133,22 @@ NTSTATUS messaging_tdb_init(struct messaging_context *msg_ctx,
 	return NT_STATUS_OK;
 }
 
+bool messaging_tdb_parent_init(void)
+{
+	struct tdb_wrap *db;
+
+	db = tdb_wrap_open(talloc_autofree_context(),
+			   lock_path("messages.tdb"), 0,
+			   TDB_CLEAR_IF_FIRST|TDB_DEFAULT|TDB_VOLATILE,
+			   O_RDWR|O_CREAT,0600);
+	if (db == NULL) {
+		DEBUG(1, ("could not open messaging.tdb: %s\n",
+			  strerror(errno)));
+		return false;
+	}
+	return true;
+}
+
 /*******************************************************************
  Form a static tdb key from a pid.
 ******************************************************************/
diff --git a/source3/smbd/server.c b/source3/smbd/server.c
index 81d75b13a0..0a6d66c180 100644
--- a/source3/smbd/server.c
+++ b/source3/smbd/server.c
@@ -1296,6 +1296,10 @@ extern void build_options(bool screen);
 	if (!locking_init())
 		exit(1);
 
+	if (!messaging_tdb_parent_init()) {
+		exit(1);
+	}
+
 	namecache_enable();
 
 	if (!W_ERROR_IS_OK(registry_init_full()))