ITS#3356 - when purging cache, free entryInfo if node has no children

diff --git a/servers/slapd/back-bdb/cache.c b/servers/slapd/back-bdb/cache.c
index 5c6b3375e99c7ee7f2112fb9cd510e92662c549b..8fc81d269856db1139ce7c7bf79b80f2ca5f2d7e 100644 (file)
--- a/servers/slapd/back-bdb/cache.c
+++ b/servers/slapd/back-bdb/cache.c
@@ -520,11 +520,17 @@ bdb_cache_lru_add(
                        /* Too many probes, not enough idle, give up */
                        if (i > 10) break;
 
+                       /* Leave DB root alone, BDB_HIER needs this */
+                       if ( elru->bei_parent && !elru->bei_parent->bei_parent )
+                               continue;
+
                        /* If we can successfully writelock it, then
                         * the object is idle.
                         */
                        if ( bdb_cache_entry_db_lock( bdb->bi_dbenv, bdb->bi_cache.c_locker, elru, 1, 1,
                                lockp ) == 0 ) {
+                               int lstat;
+
                                /* If there's no entry, or this node is in
                                 * the process of linking into the cache,
                                 * or this node is being deleted, skip it.
@@ -534,10 +540,28 @@ bdb_cache_lru_add(
                                        bdb_cache_entry_db_unlock( bdb->bi_dbenv, lockp );
                                        continue;
                                }
-                               LRU_DELETE( &bdb->bi_cache, elru );
-                               elru->bei_e->e_private = NULL;
-                               bdb_entry_return( elru->bei_e );
-                               elru->bei_e = NULL;
+                               /* If this node is in use or has children, just free the
+                                * entry and unlink from the LRU list.
+                                */
+                               lstat = ldap_pvt_thread_mutex_trylock( &elru->bei_kids_mutex );
+                               if ( lstat || elru->bei_kids ) {
+                                       LRU_DELETE( &bdb->bi_cache, elru );
+                                       elru->bei_e->e_private = NULL;
+                                       bdb_entry_return( elru->bei_e );
+                                       elru->bei_e = NULL;
+
+                                       if ( !lstat )
+                                               bdb_cache_entryinfo_unlock( elru );
+
+                               /* Else free the entry and its entryinfo.
+                                */
+                               } else {
+                                       bdb_cache_delete_internal( &bdb->bi_cache, elru );
+                                       bdb_cache_delete_cleanup( &bdb->bi_cache, elru->bei_e );
+
+                                       /* break the loop, unsafe to muck with more than one */
+                                       elprev = NULL;
+                               }
                                bdb_cache_entry_db_unlock( bdb->bi_dbenv, lockp );
                                --bdb->bi_cache.c_cursize;
                                if (bdb->bi_cache.c_cursize < bdb->bi_cache.c_maxsize)
@@ -845,15 +869,16 @@ bdb_cache_add(
        if (eip->bei_parent) {
                eip->bei_parent->bei_state &= ~CACHE_ENTRY_NO_GRANDKIDS;
        }
+       bdb_cache_entryinfo_unlock( eip );
 
        /* set lru mutex */
        ldap_pvt_thread_mutex_lock( &bdb->bi_cache.lru_mutex );
        ++bdb->bi_cache.c_cursize;
+       ldap_pvt_thread_rdwr_wunlock( &bdb->bi_cache.c_rwlock );
+
        /* lru_mutex is unlocked for us */
        bdb_cache_lru_add( bdb, locker, new );
 
-       bdb_cache_entryinfo_unlock( eip );
-       ldap_pvt_thread_rdwr_wunlock( &bdb->bi_cache.c_rwlock );
        return rc;
 }
 
@@ -992,12 +1017,6 @@ bdb_cache_delete(
                return rc;
        }
 
-       /* set cache write lock */
-       ldap_pvt_thread_rdwr_wlock( &cache->c_rwlock );
-
-       /* Lock the parent's kids tree */
-       bdb_cache_entryinfo_lock( ei->bei_parent );
-
        Debug( LDAP_DEBUG_TRACE, "====> bdb_cache_delete( %ld )\n",
                e->e_id, 0, 0 );
 
@@ -1007,10 +1026,6 @@ bdb_cache_delete(
        /* free lru mutex */
        ldap_pvt_thread_mutex_unlock( &cache->lru_mutex );
 
-       /* free cache write lock */
-       ldap_pvt_thread_rdwr_wunlock( &cache->c_rwlock );
-       bdb_cache_entryinfo_unlock( ei->bei_parent );
-
        /* Leave entry info locked */
 
        return( rc );
@@ -1054,6 +1069,12 @@ bdb_cache_delete_internal(
 {
        int rc = 0;     /* return code */
 
+       /* set cache write lock */
+       ldap_pvt_thread_rdwr_wlock( &cache->c_rwlock );
+
+       /* Lock the parent's kids tree */
+       bdb_cache_entryinfo_lock( e->bei_parent );
+
 #ifdef BDB_HIER
        e->bei_parent->bei_ckids--;
        if ( e->bei_parent->bei_dkids ) e->bei_parent->bei_dkids--;
@@ -1078,10 +1099,9 @@ bdb_cache_delete_internal(
        LRU_DELETE( cache, e );
        cache->c_cursize--;
 
-       /*
-        * flag entry to be freed later by a call to cache_return_entry()
-        */
-       e->bei_state |= CACHE_ENTRY_DELETED;
+       /* free cache write lock */
+       ldap_pvt_thread_rdwr_wunlock( &cache->c_rwlock );
+       bdb_cache_entryinfo_unlock( e->bei_parent );
 
        return( 0 );
 }