From 397d1936ec34fa573c7d46cc51c971986e8f7fe8 Mon Sep 17 00:00:00 2001
From: Volker Lendecke <vl@samba.org>
Date: Tue, 8 Nov 2016 17:01:56 +0100
Subject: [PATCH] tdb: Test for readonly lock upgrade bug
Signed-off-by: Volker Lendecke <vl@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>
Autobuild-User(master): Jeremy Allison <jra@samba.org>
Autobuild-Date(master): Tue Apr 11 00:33:31 CEST 2017 on sn-devel-144
---
lib/tdb/test/run-rdlock-upgrade.c | 166 ++++++++++++++++++++++++++++++++++++++
lib/tdb/wscript | 1 +
2 files changed, 167 insertions(+)
create mode 100644 lib/tdb/test/run-rdlock-upgrade.c
diff --git a/lib/tdb/test/run-rdlock-upgrade.c b/lib/tdb/test/run-rdlock-upgrade.c
new file mode 100644
index 0000000000000000000000000000000000000000..042001b4231530e93618f481d3fbeef4ecfd309b
--- /dev/null
+++ b/lib/tdb/test/run-rdlock-upgrade.c
@@ -0,0 +1,166 @@
+#include "../common/io.c"
+#include "../common/tdb.c"
+#include "../common/lock.c"
+#include "../common/freelist.c"
+#include "../common/traverse.c"
+#include "../common/transaction.c"
+#include "../common/error.c"
+#include "../common/open.c"
+#include "../common/check.c"
+#include "../common/hash.c"
+#include "../common/mutex.c"
+#include "tap-interface.h"
+#include <stdlib.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <stdarg.h>
+#include "logging.h"
+
+static TDB_DATA key, data;
+
+static void do_chainlock(const char *name, int tdb_flags, int up, int down)
+{
+ struct tdb_context *tdb;
+ int ret;
+ ssize_t nread, nwritten;
+ char c = 0;
+
+ tdb = tdb_open_ex(name, 3, tdb_flags,
+ O_RDWR|O_CREAT, 0755, &taplogctx, NULL);
+ ok(tdb, "tdb_open_ex should succeed");
+
+ ret = tdb_chainlock_read(tdb, key);
+ ok(ret == 0, "tdb_chainlock_read should succeed");
+
+ nwritten = write(up, &c, sizeof(c));
+ ok(nwritten == sizeof(c), "write should succeed");
+
+ nread = read(down, &c, sizeof(c));
+ ok(nread == 0, "read should succeed");
+
+ exit(0);
+}
+
+static void do_trylock(const char *name, int tdb_flags, int up, int down)
+{
+ struct tdb_context *tdb;
+ int ret;
+ ssize_t nread, nwritten;
+ char c = 0;
+
+ tdb = tdb_open_ex(name, 3, tdb_flags,
+ O_RDWR|O_CREAT, 0755, &taplogctx, NULL);
+ ok(tdb, "tdb_open_ex should succeed");
+
+ /*
+ * tdb used to have a bug where with fcntl locks an upgrade
+ * from a readlock to writelock did not check for the
+ * underlying fcntl lock. Mutexes don't distinguish between
+ * readlocks and writelocks, so that bug does not apply here.
+ */
+
+ ret = tdb_chainlock_read(tdb, key);
+ ok(ret == 0, "tdb_chainlock_read should succeed");
+
+ ret = tdb_chainlock_nonblock(tdb, key);
+ ok(ret == -1, "tdb_chainlock_nonblock should fail");
+
+ nwritten = write(up, &c, sizeof(c));
+ ok(nwritten == sizeof(c), "write should succeed");
+
+ nread = read(down, &c, sizeof(c));
+ ok(nread == 0, "read should succeed");
+
+ exit(0);
+}
+
+static int do_tests(const char *name, int tdb_flags)
+{
+ int ret;
+ pid_t chainlock_child, store_child;
+ int chainlock_down[2];
+ int chainlock_up[2];
+ int store_down[2];
+ int store_up[2];
+ char c;
+ ssize_t nread;
+
+ key.dsize = strlen("hi");
+ key.dptr = discard_const_p(uint8_t, "hi");
+ data.dsize = strlen("world");
+ data.dptr = discard_const_p(uint8_t, "world");
+
+ ret = pipe(chainlock_down);
+ ok(ret == 0, "pipe should succeed");
+
+ ret = pipe(chainlock_up);
+ ok(ret == 0, "pipe should succeed");
+
+ ret = pipe(store_down);
+ ok(ret == 0, "pipe should succeed");
+
+ ret = pipe(store_up);
+ ok(ret == 0, "pipe should succeed");
+
+ chainlock_child = fork();
+ ok(chainlock_child != -1, "fork should succeed");
+
+ if (chainlock_child == 0) {
+ close(chainlock_up[0]);
+ close(chainlock_down[1]);
+ close(store_up[0]);
+ close(store_up[1]);
+ close(store_down[0]);
+ close(store_down[1]);
+ do_chainlock(name, tdb_flags,
+ chainlock_up[1], chainlock_down[0]);
+ exit(0);
+ }
+ close(chainlock_up[1]);
+ close(chainlock_down[0]);
+
+ nread = read(chainlock_up[0], &c, sizeof(c));
+ ok(nread == sizeof(c), "read should succeed");
+
+ /*
+ * Now we have a process holding a chain read lock. Start
+ * another process trying to write lock. This should fail.
+ */
+
+ store_child = fork();
+ ok(store_child != -1, "fork should succeed");
+
+ if (store_child == 0) {
+ close(chainlock_up[0]);
+ close(chainlock_down[1]);
+ close(store_up[0]);
+ close(store_down[1]);
+ do_trylock(name, tdb_flags,
+ store_up[1], store_down[0]);
+ exit(0);
+ }
+ close(store_up[1]);
+ close(store_down[0]);
+
+ nread = read(store_up[0], &c, sizeof(c));
+ ok(nread == sizeof(c), "read should succeed");
+
+ close(chainlock_up[0]);
+ close(chainlock_down[1]);
+ close(store_up[0]);
+ close(store_down[1]);
+ diag("%s tests done", name);
+ return exit_status();
+}
+
+int main(int argc, char *argv[])
+{
+ int ret;
+
+ ret = do_tests("rdlock-upgrade.tdb",
+ TDB_CLEAR_IF_FIRST |
+ TDB_INCOMPATIBLE_HASH);
+ ok(ret == 0, "rdlock-upgrade.tdb tests should succeed");
+
+ return exit_status();
+}
diff --git a/lib/tdb/wscript b/lib/tdb/wscript
index 0d682ebb4cdaa001904e0b40e50e1a2e46f230ee..693787cb75da6462a81dcae6fba8981b99e90e69 100644
--- a/lib/tdb/wscript
+++ b/lib/tdb/wscript
@@ -34,6 +34,7 @@ tdb1_unit_tests = [
'run-readonly-check',
'run-rescue',
'run-rescue-find_entry',
+ 'run-rdlock-upgrade',
'run-rwlock-check',
'run-summary',
'run-transaction-expand',
--
2.9.3