From 4f2949b1cec228e1bb5e435faefcde5e6484ea76 Mon Sep 17 00:00:00 2001
From: Howard Chu <hyc@openldap.org>
Date: Wed, 23 Feb 2011 03:53:21 +0000
Subject: [PATCH] Use refcnt instead of keeping entry locked in Add response

---
 servers/slapd/back-bdb/add.c       | 10 +++-------
 servers/slapd/back-bdb/cache.c     | 12 ++++++++++++
 servers/slapd/back-bdb/proto-bdb.h |  2 ++
 3 files changed, 17 insertions(+), 7 deletions(-)

diff --git a/servers/slapd/back-bdb/add.c b/servers/slapd/back-bdb/add.c
index d91ee1ada8..9811177c12 100644
--- a/servers/slapd/back-bdb/add.c
+++ b/servers/slapd/back-bdb/add.c
@@ -32,7 +32,7 @@ bdb_add(Operation *op, SlapReply *rs )
 	size_t textlen = sizeof textbuf;
 	AttributeDescription *children = slap_schema.si_ad_children;
 	AttributeDescription *entry = slap_schema.si_ad_entry;
-	DB_TXN		*ltid = NULL, *lt2, *rtxn;
+	DB_TXN		*ltid = NULL, *lt2;
 	ID eid = NOID;
 	struct bdb_op_info opinfo = {{{ 0 }}};
 	int subentry;
@@ -121,9 +121,6 @@ txnReturn:
 
 	subentry = is_entry_subentry( op->ora_e );
 
-	/* Get our reader TXN */
-	rs->sr_err = bdb_reader_get( op, bdb->bi_dbenv, &rtxn );
-
 	if( 0 ) {
 retry:	/* transaction retry */
 		if( p ) {
@@ -480,8 +477,7 @@ retry:	/* transaction retry */
 			nrdn = op->ora_e->e_nname;
 		}
 
-		/* Use the reader txn here, outside the add txn */
-		bdb_cache_add( bdb, ei, op->ora_e, &nrdn, rtxn, &lock );
+		bdb_cache_add( bdb, ei, op->ora_e, &nrdn, ltid, &lock );
 
 		if(( rs->sr_err=TXN_COMMIT( ltid, 0 )) != 0 ) {
 			rs->sr_text = "txn_commit failed";
@@ -527,7 +523,7 @@ return_results:
 		 * Possibly a callback may have mucked with it, although
 		 * in general callbacks should treat the entry as read-only.
 		 */
-		bdb_cache_return_entry_r( bdb, oe, &lock );
+		bdb_cache_deref( oe->e_private );
 		if ( op->ora_e == oe )
 			op->ora_e = NULL;
 
diff --git a/servers/slapd/back-bdb/cache.c b/servers/slapd/back-bdb/cache.c
index 468b565142..a7d1757edb 100644
--- a/servers/slapd/back-bdb/cache.c
+++ b/servers/slapd/back-bdb/cache.c
@@ -1146,6 +1146,7 @@ bdb_cache_add(
 	ei.bei_nrdn = *nrdn;
 	ei.bei_lockpad = 0;
 
+#if 0
 	/* Lock this entry so that bdb_add can run to completion.
 	 * It can only fail if BDB has run out of lock resources.
 	 */
@@ -1154,6 +1155,7 @@ bdb_cache_add(
 		bdb_cache_entryinfo_unlock( eip );
 		return rc;
 	}
+#endif
 
 #ifdef BDB_HIER
 	if ( nrdn->bv_len != e->e_nname.bv_len ) {
@@ -1197,6 +1199,7 @@ bdb_cache_add(
 	}
 	ldap_pvt_thread_mutex_unlock( &bdb->bi_cache.c_count_mutex );
 
+	new->bei_finders = 1;
 	bdb_cache_lru_link( bdb, new );
 
 	if ( purge )
@@ -1205,6 +1208,15 @@ bdb_cache_add(
 	return rc;
 }
 
+int bdb_cache_deref(
+	EntryInfo *ei
+	)
+{
+	bdb_cache_entryinfo_lock( ei );
+	ei->bei_finders--;
+	bdb_cache_entryinfo_unlock( ei );
+}
+
 int
 bdb_cache_modify(
 	struct bdb_info *bdb,
diff --git a/servers/slapd/back-bdb/proto-bdb.h b/servers/slapd/back-bdb/proto-bdb.h
index de6b4d4957..f0070775d2 100644
--- a/servers/slapd/back-bdb/proto-bdb.h
+++ b/servers/slapd/back-bdb/proto-bdb.h
@@ -507,6 +507,7 @@ void bdb_unlocked_cache_return_entry_rw( struct bdb_info *bdb, Entry *e, int rw
 #define bdb_cache_modrdn			BDB_SYMBOL(cache_modrdn)
 #define bdb_cache_release_all		BDB_SYMBOL(cache_release_all)
 #define bdb_cache_delete_entry		BDB_SYMBOL(cache_delete_entry)
+#define bdb_cache_deref				BDB_SYMBOL(cache_deref)
 
 int bdb_cache_children(
 	Operation *op,
@@ -574,6 +575,7 @@ void bdb_cache_delete_cleanup(
 	EntryInfo *ei
 );
 void bdb_cache_release_all( Cache *cache );
+void bdb_cache_deref( EntryInfo *ei );
 
 #ifdef BDB_HIER
 int hdb_cache_load(