ITS#6095

CHANGES

@@ -12,8 +12,9 @@ OpenLDAP 2.4.17 Engineering
 	Fixed slapd normalization of updated schema attributes (ITS#5540)
 	Fixed slapd pagedresults stacked control with overlays (ITS#6056)
 	Fixed slapd sockets usage on windows (ITS#6039)
-	Fixed slapd-bdb freeing of already freed entries (ITS#6074)
-	Fixed slapd-bdb entryinfo cleanup (ITS#6088)
+	Fixed slapd-hdb freeing of already freed entries (ITS#6074)
+	Fixed slapd-hdb entryinfo cleanup (ITS#6088)
+	Fixed slapd-hdb dncache lockups (ITS#6095)
 	Added slapo-rwm rwm-drop-unrequested-attrs config option (ITS#6057)
 	Fixed slapo-rwm dn passing (ITS#6070)
 	Fixed slapo-rwm entry free (ITS#6058)

servers/slapd/back-bdb/back-bdb.h

@@ -92,6 +92,7 @@ typedef struct bdb_entry_info {
 #define	CACHE_ENTRY_ONELEVEL	0x40
 #define	CACHE_ENTRY_REFERENCED	0x80
 #define	CACHE_ENTRY_NOT_CACHED	0x100
+#define	CACHE_ENTRY_PURGED	0x200
 	int bei_finders;
 
 	/*

servers/slapd/back-bdb/cache.c

@@ -94,10 +94,14 @@ bdb_cache_entryinfo_free( Cache *cache, EntryInfo *ei )
 	ei->bei_kids = NULL;
 	ei->bei_lruprev = NULL;
 
+#if 0
 	ldap_pvt_thread_mutex_lock( &cache->c_eifree_mutex );
 	ei->bei_lrunext = cache->c_eifree;
 	cache->c_eifree = ei;
 	ldap_pvt_thread_mutex_unlock( &cache->c_eifree_mutex );
+#else
+	ch_free( ei );
+#endif
 }
 
 #define LRU_DEL( c, e ) do { \
@@ -334,8 +338,8 @@ bdb_entryinfo_add_internal(
 
 	ei2 = bdb_cache_entryinfo_new( &bdb->bi_cache );
 
-	ldap_pvt_thread_rdwr_wlock( &bdb->bi_cache.c_rwlock );
 	bdb_cache_entryinfo_lock( ei->bei_parent );
+	ldap_pvt_thread_rdwr_wlock( &bdb->bi_cache.c_rwlock );
 
 	ei2->bei_id = ei->bei_id;
 	ei2->bei_parent = ei->bei_parent;
@@ -372,13 +376,11 @@ bdb_entryinfo_add_internal(
 			bdb->bi_cache.c_leaves++;
 		rc = avl_insert( &ei->bei_parent->bei_kids, ei2, bdb_rdn_cmp,
 			avl_dup_error );
-		if ( rc ) {
-			/* This should never happen; entry cache is corrupt */
-			bdb->bi_dbenv->log_flush( bdb->bi_dbenv, NULL );
-			assert( !rc );
-		}
 #ifdef BDB_HIER
-		ei->bei_parent->bei_ckids++;
+		/* it's possible for hdb_cache_find_parent to beat us to it */
+		if ( !rc ) {
+			ei->bei_parent->bei_ckids++;
+		}
 #endif
 	}
 
@@ -443,6 +445,7 @@ bdb_cache_find_ndn(
 
 			ei.bei_nrdn.bv_len = ndn->bv_len -
 				(ei.bei_nrdn.bv_val - ndn->bv_val);
+			eip->bei_finders++;
 			bdb_cache_entryinfo_unlock( eip );
 
 			BDB_LOG_PRINTF( bdb->bi_dbenv, NULL, "slapd Reading %s",
@@ -452,6 +455,7 @@ bdb_cache_find_ndn(
 			rc = bdb_dn2id( op, &ei.bei_nrdn, &ei, txn, &lock );
 			if (rc) {
 				bdb_cache_entryinfo_lock( eip );
+				eip->bei_finders--;
 				bdb_cache_entry_db_unlock( bdb, &lock );
 				*res = eip;
 				return rc;
@@ -464,6 +468,7 @@ bdb_cache_find_ndn(
 			ei.bei_nrdn.bv_len = len;
 			rc = bdb_entryinfo_add_internal( bdb, &ei, &ei2 );
 			/* add_internal left eip and c_rwlock locked */
+			eip->bei_finders--;
 			ldap_pvt_thread_rdwr_wunlock( &bdb->bi_cache.c_rwlock );
 			bdb_cache_entry_db_unlock( bdb, &lock );
 			if ( rc ) {
@@ -480,8 +485,8 @@ bdb_cache_find_ndn(
 			*res = eip;
 			return DB_NOTFOUND;
 		}
-		bdb_cache_entryinfo_unlock( eip );
 		bdb_cache_entryinfo_lock( ei2 );
+		bdb_cache_entryinfo_unlock( eip );
 
 		eip = ei2;
 
@@ -515,7 +520,7 @@ hdb_cache_find_parent(
 {
 	struct bdb_info *bdb = (struct bdb_info *) op->o_bd->be_private;
 	EntryInfo ei, eip, *ei2 = NULL, *ein = NULL, *eir = NULL;
-	int rc;
+	int rc, add;
 
 	ei.bei_id = id;
 	ei.bei_kids = NULL;
@@ -539,36 +544,53 @@ hdb_cache_find_parent(
 		ein->bei_bdb = bdb;
 #endif
 		ei.bei_ckids = 0;
+		add = 1;
 		
 		/* This node is not fully connected yet */
 		ein->bei_state |= CACHE_ENTRY_NOT_LINKED;
 
+		/* If this is the first time, save this node
+		 * to be returned later.
+		 */
+		if ( eir == NULL ) {
+			eir = ein;
+			ein->bei_finders++;
+		}
+
+again:
 		/* Insert this node into the ID tree */
 		ldap_pvt_thread_rdwr_wlock( &bdb->bi_cache.c_rwlock );
 		if ( avl_insert( &bdb->bi_cache.c_idtree, (caddr_t)ein,
 			bdb_id_cmp, bdb_id_dup_err ) ) {
 			EntryInfo *eix = ein->bei_lrunext;
 
+			if ( eix->bei_state & (CACHE_ENTRY_PURGED|CACHE_ENTRY_DELETED) ) {
+				ldap_pvt_thread_rdwr_wunlock( &bdb->bi_cache.c_rwlock );
+				ldap_pvt_thread_yield();
+				goto again;
+			}
+			ldap_pvt_thread_rdwr_wunlock( &bdb->bi_cache.c_rwlock );
+
 			/* Someone else created this node just before us.
 			 * Free our new copy and use the existing one.
 			 */
 			bdb_cache_entryinfo_free( &bdb->bi_cache, ein );
-			ein = eix;
-			
-			/* Link in any kids we've already processed */
-			if ( ei2 ) {
-				bdb_cache_entryinfo_lock( ein );
-				avl_insert( &ein->bei_kids, (caddr_t)ei2,
-					bdb_rdn_cmp, avl_dup_error );
-				ein->bei_ckids++;
-				bdb_cache_entryinfo_unlock( ein );
+
+			/* if it was the node we were looking for, just return it */
+			if ( eir == ein ) {
+				*res = eix;
+				rc = 0;
+				bdb_cache_entryinfo_lock( eix );
+				break;
 			}
-		}
 
-		/* If this is the first time, save this node
-		 * to be returned later.
-		 */
-		if ( eir == NULL ) eir = ein;
+			ein = ei2;
+			ei2 = eix;
+			add = 0;
+
+			/* otherwise, link up what we have and return */
+			goto gotparent;
+		}
 
 		/* If there was a previous node, link it to this one */
 		if ( ei2 ) ei2->bei_parent = ein;
@@ -577,23 +599,29 @@ hdb_cache_find_parent(
 		if ( eip.bei_id ) {
 			ei2 = (EntryInfo *) avl_find( bdb->bi_cache.c_idtree,
 					(caddr_t) &eip, bdb_id_cmp );
+			if ( ei2 && ( ei2->bei_state & ( CACHE_ENTRY_PURGED|CACHE_ENTRY_DELETED ))) {
+				ei2 = NULL;
+			}
 		} else {
 			ei2 = &bdb->bi_cache.c_dntree;
 		}
-		bdb->bi_cache.c_eiused++;
-		if ( ei2 && ( ei2->bei_kids || !ei2->bei_id ))
+		if ( add ) {
+			bdb->bi_cache.c_eiused++;
+			if ( ei2 && ( ei2->bei_kids || !ei2->bei_id ))
 				bdb->bi_cache.c_leaves++;
+		}
 		ldap_pvt_thread_rdwr_wunlock( &bdb->bi_cache.c_rwlock );
 
+gotparent:
 		/* Got the parent, link in and we're done. */
 		if ( ei2 ) {
-			bdb_cache_entryinfo_lock( eir );
 			bdb_cache_entryinfo_lock( ei2 );
+			bdb_cache_entryinfo_lock( eir );
 			ein->bei_parent = ei2;
 
-			avl_insert( &ei2->bei_kids, (caddr_t)ein, bdb_rdn_cmp,
-				avl_dup_error);
-			ei2->bei_ckids++;
+			if ( avl_insert( &ei2->bei_kids, (caddr_t)ein, bdb_rdn_cmp,
+				avl_dup_error) == 0 )
+				ei2->bei_ckids++;
 
 			/* Reset all the state info */
 			for (ein = eir; ein != ei2; ein=ein->bei_parent)
@@ -724,12 +752,18 @@ bdb_cache_lru_purge( struct bdb_info *bdb )
 		 * or this node is being deleted, skip it.
 		 */
 		if (( elru->bei_state & ( CACHE_ENTRY_NOT_LINKED |
-			CACHE_ENTRY_DELETED | CACHE_ENTRY_LOADING )) ||
+			CACHE_ENTRY_DELETED | CACHE_ENTRY_LOADING |
+			CACHE_ENTRY_ONELEVEL )) ||
 			elru->bei_finders > 0 ) {
 			bdb_cache_entryinfo_unlock( elru );
 			goto bottom;
 		}
 
+		if ( bdb_cache_entryinfo_trylock( elru->bei_parent )) {
+			bdb_cache_entryinfo_unlock( elru );
+			goto bottom;
+		}
+
 		/* entryinfo is locked */
 		islocked = 1;
 
@@ -782,20 +816,13 @@ bdb_cache_lru_purge( struct bdb_info *bdb )
 		}
 
 next:
-		if ( islocked )
+		if ( islocked ) {
 			bdb_cache_entryinfo_unlock( elru );
+			bdb_cache_entryinfo_unlock( elru->bei_parent );
+		}
 
-		if ( count >= efree && eicount >= eifree ) {
-			if ( count || ecount > bdb->bi_cache.c_cursize ) {
-				ldap_pvt_thread_mutex_lock( &bdb->bi_cache.c_count_mutex );
-				/* HACK: we seem to be losing track, fix up now */
-				if ( ecount > bdb->bi_cache.c_cursize )
-					bdb->bi_cache.c_cursize = ecount;
-				bdb->bi_cache.c_cursize -= count;
-				ldap_pvt_thread_mutex_unlock( &bdb->bi_cache.c_count_mutex );
-			}
+		if ( count >= efree && eicount >= eifree )
 			break;
-		}
 bottom:
 		if ( elnext == bdb->bi_cache.c_lruhead )
 			break;
@@ -804,28 +831,19 @@ bottom:
 #endif
 	}
 
+	if ( count || ecount > bdb->bi_cache.c_cursize ) {
+		ldap_pvt_thread_mutex_lock( &bdb->bi_cache.c_count_mutex );
+		/* HACK: we seem to be losing track, fix up now */
+		if ( ecount > bdb->bi_cache.c_cursize )
+			bdb->bi_cache.c_cursize = ecount;
+		bdb->bi_cache.c_cursize -= count;
+		ldap_pvt_thread_mutex_unlock( &bdb->bi_cache.c_count_mutex );
+	}
 	bdb->bi_cache.c_lruhead = elnext;
 	ldap_pvt_thread_mutex_unlock( &bdb->bi_cache.c_lru_mutex );
 	bdb->bi_cache.c_purging = 0;
 }
 
-EntryInfo *
-bdb_cache_find_info(
-	struct bdb_info *bdb,
-	ID id )
-{
-	EntryInfo	ei = { 0 },
-			*ei2;
-
-	ei.bei_id = id;
-
-	ldap_pvt_thread_rdwr_rlock( &bdb->bi_cache.c_rwlock );
-	ei2 = (EntryInfo *) avl_find( bdb->bi_cache.c_idtree,
-					(caddr_t) &ei, bdb_id_cmp );
-	ldap_pvt_thread_rdwr_runlock( &bdb->bi_cache.c_rwlock );
-	return ei2;
-}
-
 /*
  * cache_find_id - find an entry in the cache, given id.
  * The entry is locked for Read upon return. Call with flag ID_LOCKED if
@@ -859,11 +877,12 @@ again:	ldap_pvt_thread_rdwr_rlock( &bdb->bi_cache.c_rwlock );
 		if ( *eip ) {
 			/* If the lock attempt fails, the info is in use */
 			if ( bdb_cache_entryinfo_trylock( *eip )) {
+				int del = (*eip)->bei_state & CACHE_ENTRY_DELETED;
 				ldap_pvt_thread_rdwr_runlock( &bdb->bi_cache.c_rwlock );
 				/* If this node is being deleted, treat
 				 * as if the delete has already finished
 				 */
-				if ( (*eip)->bei_state & CACHE_ENTRY_DELETED ) {
+				if ( del ) {
 					return DB_NOTFOUND;
 				}
 				/* otherwise, wait for the info to free up */
@@ -920,6 +939,10 @@ again:	ldap_pvt_thread_rdwr_rlock( &bdb->bi_cache.c_rwlock );
 		} else {
 			(*eip)->bei_finders++;
 			(*eip)->bei_state |= CACHE_ENTRY_REFERENCED;
+			if ( flag & ID_NOENTRY ) {
+				bdb_cache_entryinfo_unlock( *eip );
+				return 0;
+			}
 			/* Make sure only one thread tries to load the entry */
 load1:
 #ifdef SLAP_ZONE_ALLOC
@@ -961,6 +984,8 @@ load1:
 					if ( rc == 0 ) {
 						ep->e_private = *eip;
 #ifdef BDB_HIER
+						while ( (*eip)->bei_state & CACHE_ENTRY_NOT_LINKED )
+							ldap_pvt_thread_yield();
 						bdb_fix_dn( ep, 0 );
 #endif
 						(*eip)->bei_e = ep;
@@ -1037,7 +1062,7 @@ load1:
 			bdb->bi_cache.c_leaves > bdb->bi_cache.c_eimax ) {
 			ldap_pvt_thread_mutex_lock( &bdb->bi_cache.c_count_mutex );
 			if ( !bdb->bi_cache.c_purging ) {
-				if ( !( flag & ID_NOCACHE )) {
+				if ( load && !( flag & ID_NOCACHE )) {
 					bdb->bi_cache.c_cursize++;
 					if ( bdb->bi_cache.c_cursize > bdb->bi_cache.c_maxsize ) {
 						purge = 1;
@@ -1124,6 +1149,12 @@ bdb_cache_add(
 	if ( eip->bei_dkids ) eip->bei_dkids++;
 #endif
 
+	if (eip->bei_parent) {
+		bdb_cache_entryinfo_lock( eip->bei_parent );
+		eip->bei_parent->bei_state &= ~CACHE_ENTRY_NO_GRANDKIDS;
+		bdb_cache_entryinfo_unlock( eip->bei_parent );
+	}
+
 	rc = bdb_entryinfo_add_internal( bdb, &ei, &new );
 	/* bdb_csn_commit can cause this when adding the database root entry */
 	if ( new->bei_e ) {
@@ -1138,9 +1169,6 @@ bdb_cache_add(
 	e->e_private = new;
 	new->bei_state |= CACHE_ENTRY_NO_KIDS | CACHE_ENTRY_NO_GRANDKIDS;
 	eip->bei_state &= ~CACHE_ENTRY_NO_KIDS;
-	if (eip->bei_parent) {
-		eip->bei_parent->bei_state &= ~CACHE_ENTRY_NO_GRANDKIDS;
-	}
 	bdb_cache_entryinfo_unlock( eip );
 
 	ldap_pvt_thread_rdwr_wunlock( &bdb->bi_cache.c_rwlock );
@@ -1320,8 +1348,10 @@ bdb_cache_delete(
 	/* Get write lock on the data */
 	rc = bdb_cache_entry_db_relock( bdb, txn, ei, 1, 0, lock );
 	if ( rc ) {
+		bdb_cache_entryinfo_lock( ei );
 		/* couldn't lock, undo and give up */
 		ei->bei_state ^= CACHE_ENTRY_DELETED;
+		bdb_cache_entryinfo_unlock( ei );
 		return rc;
 	}
 
@@ -1331,7 +1361,10 @@ bdb_cache_delete(
 	/* set lru mutex */
 	ldap_pvt_thread_mutex_lock( &bdb->bi_cache.c_lru_mutex );
 
+	bdb_cache_entryinfo_lock( ei->bei_parent );
+	bdb_cache_entryinfo_lock( ei );
 	rc = bdb_cache_delete_internal( &bdb->bi_cache, e->e_private, 1 );
+	bdb_cache_entryinfo_unlock( ei );
 
 	/* free lru mutex */
 	ldap_pvt_thread_mutex_unlock( &bdb->bi_cache.c_lru_mutex );
@@ -1373,11 +1406,12 @@ bdb_cache_delete_internal(
 	int decr_leaf = 0;
 
 	/* already freed? */
-	if ( !e->bei_parent )
+	if ( !e->bei_parent ) {
+		assert(0);
 		return -1;
+	}
 
-	/* Lock the parent's kids tree */
-	bdb_cache_entryinfo_lock( e->bei_parent );
+	e->bei_state |= CACHE_ENTRY_PURGED;
 
 #ifdef BDB_HIER
 	e->bei_parent->bei_ckids--;
@@ -1388,12 +1422,11 @@ bdb_cache_delete_internal(
 		== NULL )
 	{
 		rc = -1;
+		assert(0);
 	}
 	if ( e->bei_parent->bei_kids )
 		decr_leaf = 1;
 
-	bdb_cache_entryinfo_unlock( e->bei_parent );
-
 	ldap_pvt_thread_rdwr_wlock( &cache->c_rwlock );
 	/* id tree */
 	if ( avl_delete( &cache->c_idtree, (caddr_t) e, bdb_id_cmp )) {
@@ -1402,8 +1435,10 @@ bdb_cache_delete_internal(
 			cache->c_leaves--;
 	} else {
 		rc = -1;
+		assert(0);
 	}
 	ldap_pvt_thread_rdwr_wunlock( &cache->c_rwlock );
+	bdb_cache_entryinfo_unlock( e->bei_parent );
 
 	if ( rc == 0 ){
 		/* lru */

servers/slapd/back-bdb/dn2id.c

@@ -1102,7 +1102,7 @@ hdb_dn2idl_internal(
 		cx->rc = cx->dbc->c_close( cx->dbc );
 done_one:
 		bdb_cache_entryinfo_lock( cx->ei );
-		cx->ei->bei_state ^= CACHE_ENTRY_ONELEVEL;
+		cx->ei->bei_state &= ~CACHE_ENTRY_ONELEVEL;
 		bdb_cache_entryinfo_unlock( cx->ei );
 		if ( cx->rc )
 			return cx->rc;
@@ -1151,15 +1151,23 @@ gotit:
 				for ( cx->id = bdb_idl_first( save, &idcurs );
 					cx->id != NOID;
 					cx->id = bdb_idl_next( save, &idcurs )) {
-					cx->ei = bdb_cache_find_info( cx->bdb, cx->id );
+					EntryInfo *ei2;
+					cx->ei = NULL;
+					if ( bdb_cache_find_id( cx->op, cx->txn, cx->id, &cx->ei,
+						ID_NOENTRY, NULL ))
+						continue;
 					if ( !cx->ei ||
 						( cx->ei->bei_state & CACHE_ENTRY_NO_KIDS ))
 						continue;
 
+					ei2 = cx->ei;
 					BDB_ID2DISK( cx->id, &cx->nid );
 					hdb_dn2idl_internal( cx );
 					if ( !BDB_IDL_IS_ZERO( cx->tmp ))
 						nokids = 0;
+					bdb_cache_entryinfo_lock( ei2 );
+					ei2->bei_finders--;
+					bdb_cache_entryinfo_unlock( ei2 );
 				}
 				cx->depth--;
 				cx->op->o_tmpfree( save, cx->op->o_tmpmemctx );

servers/slapd/back-bdb/proto-bdb.h

@@ -501,7 +501,6 @@ void bdb_unlocked_cache_return_entry_rw( struct bdb_info *bdb, Entry *e, int rw
 #define bdb_cache_delete			BDB_SYMBOL(cache_delete)
 #define bdb_cache_delete_cleanup	BDB_SYMBOL(cache_delete_cleanup)
 #define bdb_cache_find_id			BDB_SYMBOL(cache_find_id)
-#define bdb_cache_find_info			BDB_SYMBOL(cache_find_info)
 #define bdb_cache_find_ndn			BDB_SYMBOL(cache_find_ndn)
 #define bdb_cache_find_parent		BDB_SYMBOL(cache_find_parent)
 #define bdb_cache_modify			BDB_SYMBOL(cache_modify)
@@ -544,13 +543,10 @@ int bdb_cache_find_ndn(
 	struct berval   *ndn,
 	EntryInfo	**res
 );
-EntryInfo * bdb_cache_find_info(
-	struct bdb_info *bdb,
-	ID id
-);
 
 #define	ID_LOCKED	1
 #define	ID_NOCACHE	2
+#define	ID_NOENTRY	4
 int bdb_cache_find_id(
 	Operation *op,
 	DB_TXN	*tid,

servers/slapd/back-bdb/search.c

@@ -569,10 +569,6 @@ dn2entry_retry:
 #ifdef SLAP_ZONE_ALLOC
 	slap_zn_runlock(bdb->bi_cache.c_zctx, e);
 #endif
-	if ( e != e_root ) {
-		bdb_cache_return_entry_r(bdb, e, &lock);
-	}
-	e = NULL;
 
 	/* select candidates */
 	if ( op->oq_search.rs_scope == LDAP_SCOPE_BASE ) {
@@ -595,6 +591,11 @@ cand_retry:
 		}
 	}
 
+	if ( e != e_root ) {
+		bdb_cache_return_entry_r(bdb, e, &lock);
+	}
+	e = NULL;
+
 	/* start cursor at beginning of candidates.
 	 */
 	cursor = 0;