X-Git-Url: https://git.sur5r.net/?a=blobdiff_plain;f=servers%2Fslapd%2Fback-mdb%2Fsearch.c;h=d90125e8e46dcc0d5688ec5868b447f0b666c8f5;hb=b0bc71be36cfb84bb227a805d01f33ad5f812d6c;hp=5cc0d28c00b5f3d0ff91f081a06f6a461a6bf97e;hpb=18af0bdbce961c3b5d5ee09992cea7ec972cdb1f;p=openldap

diff --git a/servers/slapd/back-mdb/search.c b/servers/slapd/back-mdb/search.c
index 5cc0d28c00..d90125e8e4 100644
--- a/servers/slapd/back-mdb/search.c
+++ b/servers/slapd/back-mdb/search.c
@@ -2,7 +2,7 @@
 /* $OpenLDAP$ */
 /* This work is part of OpenLDAP Software <http://www.openldap.org/>.
  *
- * Copyright 2000-2013 The OpenLDAP Foundation.
+ * Copyright 2000-2014 The OpenLDAP Foundation.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -34,7 +34,8 @@ static int search_candidates(
 	MDB_txn *txn,
 	MDB_cursor *mci,
 	ID	*ids,
-	ID2L	scopes );
+	ID2L	scopes,
+	ID *stack );
 
 static int parse_paged_cookie( Operation *op, SlapReply *rs );
 
@@ -313,6 +314,77 @@ static void scope_chunk_ret( Operation *op, ID2 *scopes )
 			(void *)scopes, scope_chunk_free, NULL, NULL );
 }
 
+static void *search_stack( Operation *op );
+
+typedef struct ww_ctx {
+	MDB_txn *txn;
+	MDB_cursor *mcd;	/* if set, save cursor context */
+	ID key;
+	MDB_val data;
+	int flag;
+} ww_ctx;
+
+/* ITS#7904 if we get blocked while writing results to client,
+ * release the current reader txn and reacquire it after we
+ * unblock.
+ * Slight problem - if we're doing a scope-based walk (mdb_dn2id_walk)
+ * to return results, we need to remember the state of the mcd cursor.
+ * If the node that cursor was pointing to gets deleted while we're
+ * blocked, we may be unable to restore the cursor position. In that
+ * case return an LDAP_BUSY error - let the client know this search
+ * couldn't succeed, but might succeed on a retry.
+ */
+static void
+mdb_writewait( Operation *op, slap_callback *sc )
+{
+	ww_ctx *ww = sc->sc_private;
+	if ( !ww->flag ) {
+		if ( ww->mcd ) {
+			MDB_val key, data;
+			mdb_cursor_get( ww->mcd, &key, &data, MDB_GET_CURRENT );
+			memcpy( &ww->key, key.mv_data, sizeof(ID) );
+			ww->data.mv_size = data.mv_size;
+			ww->data.mv_data = op->o_tmpalloc( data.mv_size, op->o_tmpmemctx );
+			memcpy(ww->data.mv_data, data.mv_data, data.mv_size);
+		}
+		mdb_txn_reset( ww->txn );
+		ww->flag = 1;
+	}
+}
+
+static int
+mdb_waitfixup( Operation *op, ww_ctx *ww, MDB_cursor *mci, MDB_cursor *mcd )
+{
+	int rc = 0;
+	ww->flag = 0;
+	mdb_txn_renew( ww->txn );
+	mdb_cursor_renew( ww->txn, mci );
+	mdb_cursor_renew( ww->txn, mcd );
+	if ( ww->mcd ) {
+		MDB_val key, data;
+		key.mv_size = sizeof(ID);
+		key.mv_data = &ww->key;
+		data = ww->data;
+		rc = mdb_cursor_get( mcd, &key, &data, MDB_GET_BOTH );
+		if ( rc == MDB_NOTFOUND ) {
+			data = ww->data;
+			rc = mdb_cursor_get( mcd, &key, &data, MDB_GET_BOTH_RANGE );
+			/* the loop will skip this node using NEXT_DUP but we want it
+			 * sent, so go back one space first
+			 */
+			if ( rc == MDB_SUCCESS )
+				mdb_cursor_get( mcd, &key, &data, MDB_PREV_DUP );
+			else
+				rc = LDAP_BUSY;
+		} else if ( rc ) {
+			rc = LDAP_OTHER;
+		}
+		op->o_tmpfree( ww->data.mv_data, op->o_tmpmemctx );
+		ww->data.mv_data = NULL;
+	}
+	return rc;
+}
+
 int
 mdb_search( Operation *op, SlapReply *rs )
 {
@@ -322,6 +394,7 @@ mdb_search( Operation *op, SlapReply *rs )
 	ID		candidates[MDB_IDL_UM_SIZE];
 	ID		iscopes[MDB_IDL_DB_SIZE];
 	ID2		*scopes;
+	void	*stack;
 	Entry		*e = NULL, *base = NULL;
 	Entry		*matched = NULL;
 	AttributeName	*attrs;
@@ -331,6 +404,8 @@ mdb_search( Operation *op, SlapReply *rs )
 	int		tentries = 0;
 	IdScopes	isc;
 	MDB_cursor	*mci, *mcd;
+	ww_ctx wwctx;
+	slap_callback cb = { 0 };
 
 	mdb_op_info	opinfo = {{{0}}}, *moi = &opinfo;
 	MDB_txn			*ltid = NULL;
@@ -365,10 +440,12 @@ mdb_search( Operation *op, SlapReply *rs )
 	}
 
 	scopes = scope_chunk_get( op );
+	stack = search_stack( op );
 	isc.mt = ltid;
 	isc.mc = mcd;
 	isc.scopes = scopes;
 	isc.oscope = op->ors_scope;
+	isc.sctmp = stack;
 
 	if ( op->ors_deref & LDAP_DEREF_FINDING ) {
 		MDB_IDL_ZERO(candidates);
@@ -562,7 +639,7 @@ dn2entry_retry:
 		scopes[1].mid = base->e_id;
 		scopes[1].mval.mv_data = NULL;
 		rs->sr_err = search_candidates( op, rs, base,
-			ltid, mci, candidates, scopes );
+			ltid, mci, candidates, scopes, stack );
 		ncand = MDB_IDL_N( candidates );
 		if ( !base->e_id || ncand == NOID ) {
 			/* grab entry count from id2entry stat
@@ -655,6 +732,7 @@ dn2entry_retry:
 			iscopes[0] = 0;
 		}
 
+		wwctx.mcd = mcd;
 		isc.id = base->e_id;
 		isc.numrdns = 0;
 		rc = mdb_dn2id_walk( op, &isc );
@@ -665,6 +743,17 @@ dn2entry_retry:
 		cscope = 0;
 	} else {
 		id = mdb_idl_first( candidates, &cursor );
+		wwctx.mcd = NULL;
+	}
+
+	wwctx.flag = 0;
+	/* If we're running in our own read txn */
+	if (  moi == &opinfo ) {
+		cb.sc_writewait = mdb_writewait;
+		cb.sc_private = &wwctx;
+		wwctx.txn = ltid;
+		cb.sc_next = op->o_callback;
+		op->o_callback = &cb;
 	}
 
 	while (id != NOID)
@@ -806,7 +895,7 @@ notfound:
 				goto done;
 			}
 
-			rs->sr_err = mdb_entry_decode( op, &edata, &e );
+			rs->sr_err = mdb_entry_decode( op, ltid, &edata, &e );
 			if ( rs->sr_err ) {
 				rs->sr_err = LDAP_OTHER;
 				rs->sr_text = "internal error in mdb_entry_decode";
@@ -930,7 +1019,8 @@ notfound:
 
 			send_search_reference( op, rs );
 
-			mdb_entry_return( op, e );
+			if (e != base)
+				mdb_entry_return( op, e );
 			rs->sr_entry = NULL;
 			e = NULL;
 
@@ -938,6 +1028,14 @@ notfound:
 			ber_bvarray_free( erefs );
 			rs->sr_ref = NULL;
 
+			if ( wwctx.flag ) {
+				rs->sr_err = mdb_waitfixup( op, &wwctx, mci, mcd );
+				if ( rs->sr_err ) {
+					send_ldap_result( op, rs );
+					goto done;
+				}
+			}
+
 			goto loop_continue;
 		}
 
@@ -977,6 +1075,9 @@ notfound:
 					break;
 				default:		/* entry not sent */
 					break;
+				case LDAP_BUSY:
+					send_ldap_result( op, rs );
+					goto done;
 				case LDAP_UNAVAILABLE:
 				case LDAP_SIZELIMIT_EXCEEDED:
 					if ( rs->sr_err == LDAP_SIZELIMIT_EXCEEDED ) {
@@ -989,6 +1090,13 @@ notfound:
 					}
 					goto done;
 				}
+				if ( wwctx.flag ) {
+					rs->sr_err = mdb_waitfixup( op, &wwctx, mci, mcd );
+					if ( rs->sr_err ) {
+						send_ldap_result( op, rs );
+						goto done;
+					}
+				}
 			}
 
 		} else {
@@ -1053,6 +1161,17 @@ nochange:
 	rs->sr_err = LDAP_SUCCESS;
 
 done:
+	if ( cb.sc_private ) {
+		/* remove our writewait callback */
+		slap_callback **scp = &op->o_callback;
+		while ( *scp ) {
+			if ( *scp == &cb ) {
+				*scp = cb.sc_next;
+				cb.sc_private = NULL;
+				break;
+			}
+		}
+	}
 	mdb_cursor_close( mcd );
 	mdb_cursor_close( mci );
 	if ( moi == &opinfo ) {
@@ -1066,7 +1185,7 @@ done:
 		rs->sr_v2ref = NULL;
 	}
 	if (base)
-		mdb_entry_return( op,base);
+		mdb_entry_return( op, base );
 	scope_chunk_ret( op, scopes );
 
 	return rs->sr_err;
@@ -1158,12 +1277,12 @@ static int search_candidates(
 	MDB_txn *txn,
 	MDB_cursor *mci,
 	ID	*ids,
-	ID2L	scopes )
+	ID2L	scopes,
+	ID *stack )
 {
 	struct mdb_info *mdb = (struct mdb_info *) op->o_bd->be_private;
 	int rc, depth = 1;
 	Filter		*f, rf, xf, nf, sf;
-	ID		*stack;
 	AttributeAssertion aa_ref = ATTRIBUTEASSERTION_INIT;
 	AttributeAssertion aa_subentry = ATTRIBUTEASSERTION_INIT;
 
@@ -1218,8 +1337,6 @@ static int search_candidates(
 	/* Allocate IDL stack, plus 1 more for former tmp */
 	if ( depth+1 > mdb->mi_search_stack_depth ) {
 		stack = ch_malloc( (depth + 1) * MDB_IDL_UM_SIZE * sizeof( ID ) );
-	} else {
-		stack = search_stack( op );
 	}
 
 	if( op->ors_deref & LDAP_DEREF_SEARCHING ) {