From f81ad346ffabe0084ddfab3008e7c12a7b6f8c95 Mon Sep 17 00:00:00 2001
From: Howard Chu <hyc@openldap.org>
Date: Sun, 4 Sep 2005 15:48:44 +0000
Subject: [PATCH] ITS#3978: Added alock calls; warns about inconsistency but
 continues to start. Fails for concurrent access attempts, since ldbm does not
 support any concurrency. (So slaptools are prevented from running when slapd
 is already active.)

---
 servers/slapd/back-ldbm/back-ldbm.h |  2 ++
 servers/slapd/back-ldbm/close.c     |  8 +++++++-
 servers/slapd/back-ldbm/init.c      | 22 ++++++++++++++++++++++
 3 files changed, 31 insertions(+), 1 deletion(-)

diff --git a/servers/slapd/back-ldbm/back-ldbm.h b/servers/slapd/back-ldbm/back-ldbm.h
index 6119e0ad9c..ea1c96acc6 100644
--- a/servers/slapd/back-ldbm/back-ldbm.h
+++ b/servers/slapd/back-ldbm/back-ldbm.h
@@ -18,6 +18,7 @@
 #define _BACK_LDBM_H_
 
 #include "ldbm.h"
+#include "alock.h"
 
 LDAP_BEGIN_DECL
 
@@ -152,6 +153,7 @@ struct ldbminfo {
 	int			li_dbsyncwaitn;
 	int			li_dbsyncwaitinterval;
 	int			li_dbsyncwaitcount;
+	alock_info_t	li_alock_info;
 };
 
 LDAP_END_DECL
diff --git a/servers/slapd/back-ldbm/close.c b/servers/slapd/back-ldbm/close.c
index 2e2090e286..9c26976697 100644
--- a/servers/slapd/back-ldbm/close.c
+++ b/servers/slapd/back-ldbm/close.c
@@ -26,12 +26,18 @@
 int
 ldbm_back_db_close( Backend *be )
 {
+	struct ldbminfo *li = be->be_private;
+
 	Debug( LDAP_DEBUG_TRACE, "ldbm backend syncing\n", 0, 0, 0 );
 
 	ldbm_cache_flush_all( be );
 	Debug( LDAP_DEBUG_TRACE, "ldbm backend done syncing\n", 0, 0, 0 );
 
-	cache_release_all( &((struct ldbminfo *) be->be_private)->li_cache );
+	cache_release_all( &li->li_cache );
+	if ( alock_close( &li->li_alock_info )) {
+		Debug( LDAP_DEBUG_ANY,
+			"ldbm_back_db_close: alock_close failed\n", 0, 0, 0 );
+	}
 
 	return 0;
 }
diff --git a/servers/slapd/back-ldbm/init.c b/servers/slapd/back-ldbm/init.c
index b8a6831ce5..1ceb19bc5c 100644
--- a/servers/slapd/back-ldbm/init.c
+++ b/servers/slapd/back-ldbm/init.c
@@ -195,6 +195,28 @@ ldbm_back_db_open(
 )
 {
 	struct ldbminfo *li = (struct ldbminfo *) be->be_private;
+	int rc;
+
+	rc = alock_open( &li->li_alock_info, "slapd",
+		li->li_directory, ALOCK_UNIQUE );
+	if ( rc == ALOCK_BUSY ) {
+		Debug( LDAP_DEBUG_ANY,
+			"ldbm_back_db_open: database already in use\n",
+			0, 0, 0 );
+		return -1;
+	} else if ( rc == ALOCK_RECOVER ) {
+		Debug( LDAP_DEBUG_ANY,
+			"ldbm_back_db_open: unclean shutdown detected;"
+			" database may be inconsistent!\n",
+			0, 0, 0 );
+		rc = alock_recover( &li->li_alock_info );
+	}
+	if ( rc != ALOCK_CLEAN ) {
+		Debug( LDAP_DEBUG_ANY,
+			"ldbm_back_db_open: alock package is unstable;"
+			" database may be inconsistent!\n",
+			0, 0, 0 );
+	}
 	li->li_dbenv = ldbm_initialize_env( li->li_directory,
 		li->li_dbcachesize, &li->li_envdirok );
 
-- 
2.39.5