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

diff --git a/lib/tdb/test/run-rdlock-upgrade.c b/lib/tdb/test/run-rdlock-upgrade.c
new file mode 100644 (file)
index 0000000..042001b
--- /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 (file)
--- 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',