Re-order EntryInfo/DB locks to fix deadlocks

diff --git a/servers/slapd/back-bdb/cache.c b/servers/slapd/back-bdb/cache.c
index 2f3d58e625e94f59c2e7bebfa3ed871f007b32fb..24d2a2edfd3f6d14c9475c0f1bdcd0b983b75bf9 100644 (file)
--- a/servers/slapd/back-bdb/cache.c
+++ b/servers/slapd/back-bdb/cache.c
@@ -655,20 +655,22 @@ again:    ldap_pvt_thread_rdwr_rlock( &bdb->bi_cache.c_rwlock );
                if ( (*eip)->bei_state & CACHE_ENTRY_DELETED ) {
                        rc = DB_NOTFOUND;
                } else {
-                       rc = bdb_cache_entry_db_lock( bdb->bi_dbenv, locker, *eip, 0, 0, lock );
-                       /* entry is protected now, we don't need to hold the entryinfo */
                        if ( islocked ) {
                                bdb_cache_entryinfo_unlock( *eip );
                                islocked = 0;
                        }
-                       if ( rc == 0 ) {
+                       rc = bdb_cache_entry_db_lock( bdb->bi_dbenv, locker, *eip, 0, 0, lock );
+                       if ( (*eip)->bei_state & CACHE_ENTRY_DELETED ) {
+                               rc = DB_NOTFOUND;
+                               bdb_cache_entry_db_unlock( bdb->bi_dbenv, lock );
+                       } else if ( rc == 0 ) {
                                if ( !(*eip)->bei_e ) {
+                                       bdb_cache_entry_db_relock( bdb->bi_dbenv, locker,
+                                               *eip, 1, 0, lock );
                                        if (!ep) {
                                                rc = bdb_id2entry( op->o_bd, tid, id, &ep );
                                        }
                                        if ( rc == 0 ) {
-                                               bdb_cache_entry_db_relock( bdb->bi_dbenv, locker,
-                                                       *eip, 1, 0, lock );
                                                /* Make sure no other modifier beat us to it */
                                                if ( (*eip)->bei_e ) {
                                                        bdb_entry_return( ep );
@@ -708,6 +710,9 @@ again:      ldap_pvt_thread_rdwr_rlock( &bdb->bi_cache.c_rwlock );
                        }
                }
        }
+       if ( islocked ) {
+               bdb_cache_entryinfo_unlock( *eip );
+       }
        if ( rc == 0 ) {
                /* set lru mutex */
                ldap_pvt_thread_mutex_lock( &bdb->bi_cache.lru_mutex );
@@ -722,9 +727,6 @@ again:      ldap_pvt_thread_rdwr_rlock( &bdb->bi_cache.c_rwlock );
                bdb_cache_lru_add( bdb, locker, *eip );
        }
 
-       if ( islocked ) {
-               bdb_cache_entryinfo_unlock( *eip );
-       }
        return rc;
 }