[LTP] [PATCH 4/5] fcntl43: test for identical F_SETLKW lock requests

[Alexander Aring]

This patch adds fcntl43 to test two identical lock requests at the same
time. They are identical as they will be granted at the same time.

Signed-off-by: Alexander Aring <aahringo@redhat.com>
---
 testcases/kernel/syscalls/fcntl/.gitignore |   2 +
 testcases/kernel/syscalls/fcntl/Makefile   |   3 +
 testcases/kernel/syscalls/fcntl/fcntl43.c  | 140 +++++++++++++++++++++
 3 files changed, 145 insertions(+)
 create mode 100644 testcases/kernel/syscalls/fcntl/fcntl43.c

diff --git a/testcases/kernel/syscalls/fcntl/.gitignore b/testcases/kernel/syscalls/fcntl/.gitignore
index abffa2967..6622aedbc 100644
--- a/testcases/kernel/syscalls/fcntl/.gitignore
+++ b/testcases/kernel/syscalls/fcntl/.gitignore
@@ -80,3 +80,5 @@
 /fcntl41_64
 /fcntl42
 /fcntl42_64
+/fcntl43
+/fcntl43_64
diff --git a/testcases/kernel/syscalls/fcntl/Makefile b/testcases/kernel/syscalls/fcntl/Makefile
index c3196a527..7478b87ec 100644
--- a/testcases/kernel/syscalls/fcntl/Makefile
+++ b/testcases/kernel/syscalls/fcntl/Makefile
@@ -15,6 +15,9 @@ fcntl36_64: LDLIBS += -lpthread
 fcntl40: LDLIBS += -lpthread
 fcntl40_64: LDLIBS += -lpthread
 
+fcntl43: LDLIBS += -lpthread
+fcntl43_64: LDLIBS += -lpthread
+
 include $(top_srcdir)/include/mk/testcases.mk
 include $(abs_srcdir)/../utils/newer_64.mk
 
diff --git a/testcases/kernel/syscalls/fcntl/fcntl43.c b/testcases/kernel/syscalls/fcntl/fcntl43.c
new file mode 100644
index 000000000..0a69396a4
--- /dev/null
+++ b/testcases/kernel/syscalls/fcntl/fcntl43.c
@@ -0,0 +1,140 @@
+/*
+ * [Description]
+ * Tests gfs2 dlm posix op queue handling in the kernel.
+ * It is recommended to run watch -n 0.1 "dlm_tool plocks $LS"
+ * aside to monitor dlm plock handling.
+ *
+ * This testcase creates two lock requests which looks identical and should
+ * be granted at the same time.
+ *
+ * [How to use it]
+ * Call it with TMPDIR=/mnt ./fcntl43 where TMPDIR is a gfs2 mountpoint.
+ * Try it on other filesystems to compare results.
+ */
+
+#include <sys/wait.h>
+#include <pthread.h>
+
+#include "tst_safe_pthread.h"
+#include "tst_test.h"
+
+static int fd;
+
+static void *do_thread1(void *arg)
+{
+	const struct flock fl = {
+		.l_type = F_WRLCK,
+		.l_whence = SEEK_SET,
+		.l_start = 0L,
+		.l_len = 1L,
+	};
+	(void)arg;
+
+	tst_res(TINFO, "thread1 waits for thread2 to lock 0-0");
+	TST_CHECKPOINT_WAIT(1);
+
+	tst_res(TINFO, "thread1 lock region 0-0 - It should block");
+	SAFE_FCNTL(fd, F_SETLKW, &fl);
+	tst_res(TINFO, "lock region 0-0 acquired");
+
+	return NULL;
+}
+
+static void *do_thread2(void *arg)
+{
+	const struct flock fl = {
+		.l_type = F_WRLCK,
+		.l_whence = SEEK_SET,
+		.l_start = 0L,
+		.l_len = 1L,
+	};
+	(void)arg;
+
+	tst_res(TINFO, "thread1 lock region 0-0 - It should block");
+	SAFE_FCNTL(fd, F_SETLKW, &fl);
+	tst_res(TINFO, "lock region 0-0 acquired");
+
+	return NULL;
+}
+
+void do_child(void)
+{
+	pthread_t t1, t2;
+
+	SAFE_PTHREAD_CREATE(&t1, NULL, do_thread1, NULL);
+	SAFE_PTHREAD_CREATE(&t2, NULL, do_thread2, NULL);
+
+	SAFE_PTHREAD_JOIN(t1, NULL);
+	SAFE_PTHREAD_JOIN(t2, NULL);
+
+	tst_res(TPASS, "Child passed!");
+}
+
+void do_parent(void)
+{
+	struct flock fl = {
+		.l_whence = SEEK_SET,
+	};
+
+	/* wait for 1 seconds so thread2 lock 0-0 tries to acquires at first
+	 * than thread1 lock 0-0 tries to acquired to have a specific waiting
+	 * order in dlm posix handling.
+	 */
+	sleep(1);
+	/* tell thread2 to call SETLKW for lock 0-0 */
+	TST_CHECKPOINT_WAKE(1);
+	/* wait 3 seconds for thread 1 and 2 being in waiting state */
+	sleep(3);
+
+	/* unlock 0-0, should be successful */
+	fl.l_type = F_UNLCK;
+	fl.l_start = 0;
+	fl.l_len = 1;
+	tst_res(TINFO, "unlock region 0-0 thread2");
+	SAFE_FCNTL(fd, F_SETLK, &fl);
+}
+
+static void fcntl40_test(void)
+{
+	struct flock fl = {
+		.l_type = F_WRLCK,
+		.l_whence = SEEK_SET,
+		.l_start = 0L,
+		.l_len = 2L,
+	};
+	pid_t pid;
+
+	tst_res(TINFO, "parent lock region 0-1 - should be successful");
+	SAFE_FCNTL(fd, F_SETLK, &fl);
+	tst_res(TINFO, "parent region 0-1 locked");
+
+	pid = SAFE_FORK();
+	if (pid == 0) {
+		do_child();
+		return;
+	}
+
+	do_parent();
+	wait(NULL);
+
+	tst_res(TPASS, "Parent passed!");
+}
+
+static void setup(void)
+{
+	fd = SAFE_OPEN("filename", O_RDWR | O_CREAT, 0700);
+}
+
+static void cleanup(void)
+{
+	if (fd > -1)
+		SAFE_CLOSE(fd);
+}
+
+static struct tst_test test = {
+	.forks_child = 1,
+	.needs_checkpoints = 1,
+	.test_all = fcntl40_test,
+	.setup = setup,
+	.cleanup = cleanup,
+};
-- 
2.31.1