ldb_tdb: Disallow TDB nested transactions and use tdb_transaction_active()

This avoids keeping a counter, which can be error-prone.

Signed-off-by: Andrew Bartlett <abartlet@samba.org>
Signed-off-by: Gary Lockyer <gary@catalyst.net.nz>

diff --git a/lib/ldb/ldb_tdb/ldb_tdb.c b/lib/ldb/ldb_tdb/ldb_tdb.c
index 31b4a7d9abb4c3e1f2f9856a1aa45a3c910d0258..fc14e170c89915c03e331dd5bcad19848265620a 100644 (file)
--- a/lib/ldb/ldb_tdb/ldb_tdb.c
+++ b/lib/ldb/ldb_tdb/ldb_tdb.c
@@ -101,7 +101,7 @@ static int ltdb_lock_read(struct ldb_module *module)
        int tdb_ret = 0;
        int ret;
 
-       if (ltdb->in_transaction == 0 &&
+       if (tdb_transaction_active(ltdb->tdb) == false &&
            ltdb->read_lock_count == 0) {
                tdb_ret = tdb_lockall_read(ltdb->tdb);
        }
@@ -128,7 +128,7 @@ static int ltdb_unlock_read(struct ldb_module *module)
 {
        void *data = ldb_module_get_private(module);
        struct ltdb_private *ltdb = talloc_get_type(data, struct ltdb_private);
-       if (ltdb->in_transaction == 0 && ltdb->read_lock_count == 1) {
+       if (!tdb_transaction_active(ltdb->tdb) && ltdb->read_lock_count == 1) {
                tdb_unlockall_read(ltdb->tdb);
                ltdb->read_lock_count--;
                return 0;
@@ -379,7 +379,7 @@ static int ltdb_modified(struct ldb_module *module, struct ldb_dn *dn)
 
        /* only allow modifies inside a transaction, otherwise the
         * ldb is unsafe */
-       if (ltdb->in_transaction == 0) {
+       if (ltdb->kv_ops->transaction_active(ltdb) == false) {
                ldb_set_errstring(ldb_module_get_ctx(module), "ltdb modify without transaction");
                return LDB_ERR_OPERATIONS_ERROR;
        }
@@ -1479,7 +1479,6 @@ static int ltdb_start_trans(struct ldb_module *module)
                return ltdb->kv_ops->error(ltdb);
        }
 
-       ltdb->in_transaction++;
 
        ltdb_index_transaction_start(module);
 
@@ -1500,8 +1499,11 @@ static int ltdb_prepare_commit(struct ldb_module *module)
        void *data = ldb_module_get_private(module);
        struct ltdb_private *ltdb = talloc_get_type(data, struct ltdb_private);
 
-       if (ltdb->in_transaction != 1) {
-               return LDB_SUCCESS;
+       if (!ltdb->kv_ops->transaction_active(ltdb)) {
+               ldb_set_errstring(ldb_module_get_ctx(module),
+                                 "ltdb_prepare_commit() called "
+                                 "without transaction active");
+               return LDB_ERR_OPERATIONS_ERROR;
        }
 
        /*
@@ -1525,13 +1527,11 @@ static int ltdb_prepare_commit(struct ldb_module *module)
        ret = ltdb_index_transaction_commit(module);
        if (ret != LDB_SUCCESS) {
                ltdb->kv_ops->abort_write(ltdb);
-               ltdb->in_transaction--;
                return ret;
        }
 
        if (ltdb->kv_ops->prepare_write(ltdb) != 0) {
                ret = ltdb->kv_ops->error(ltdb);
-               ltdb->in_transaction--;
                ldb_debug_set(ldb_module_get_ctx(module),
                              LDB_DEBUG_FATAL,
                              "Failure during "
@@ -1559,7 +1559,6 @@ static int ltdb_end_trans(struct ldb_module *module)
                }
        }
 
-       ltdb->in_transaction--;
        ltdb->prepared_commit = false;
 
        if (ltdb->kv_ops->finish_write(ltdb) != 0) {
@@ -1579,7 +1578,6 @@ static int ltdb_del_trans(struct ldb_module *module)
        void *data = ldb_module_get_private(module);
        struct ltdb_private *ltdb = talloc_get_type(data, struct ltdb_private);
 
-       ltdb->in_transaction--;
 
        if (ltdb_index_transaction_cancel(module) != 0) {
                ltdb->kv_ops->abort_write(ltdb);
@@ -1809,7 +1807,7 @@ static int ltdb_tdb_traverse_fn(struct ltdb_private *ltdb, ldb_kv_traverse_fn fn
                .ctx = ctx,
                .ltdb = ltdb
        };
-       if (ltdb->in_transaction != 0) {
+       if (tdb_transaction_active(ltdb->tdb)) {
                return tdb_traverse(ltdb->tdb, ldb_tdb_traverse_fn_wrapper, &kv_ctx);
        } else {
                return tdb_traverse_read(ltdb->tdb, ldb_tdb_traverse_fn_wrapper, &kv_ctx);
@@ -2215,7 +2213,7 @@ int ltdb_connect(struct ldb_context *ldb, const char *url,
                path = url;
        }
 
-       tdb_flags = TDB_DEFAULT | TDB_SEQNUM;
+       tdb_flags = TDB_DEFAULT | TDB_SEQNUM | TDB_DISALLOW_NESTING;
 
        /* check for the 'nosync' option */
        if (flags & LDB_FLG_NOSYNC) {

diff --git a/lib/ldb/ldb_tdb/ldb_tdb.h b/lib/ldb/ldb_tdb/ldb_tdb.h
index 72ebb9713f2f70ebbb20201fe4a79b2ed1107afa..4d531208da6f00d9ee7909bf4018ea7c287dd571 100644 (file)
--- a/lib/ldb/ldb_tdb/ldb_tdb.h
+++ b/lib/ldb/ldb_tdb/ldb_tdb.h
@@ -53,7 +53,6 @@ struct ltdb_private {
                const char *GUID_index_dn_component;
        } *cache;
 
-       int in_transaction;
 
        bool check_base;
        bool disallow_dn_filter;