zdtm:fifo: check that read only fifo descriptor is restored

* Create fifo and two descriptors rw and ro
* Write data and close rw descriptor
* Suspend/resume
* Read data from ro descriptor
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

test/zdtm/live/static/Makefile

@@ -64,6 +64,7 @@ TST_FILE	=				\
 		unlink_largefile		\
 		mtime_mmap			\
 		fifo				\
+		fifo_ro				\
 		fifo_wronly			\
 		unlink_fifo			\
 		unlink_fifo_wronly		\

test/zdtm/live/static/fifo_ro.c

+#include <errno.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <sys/mount.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+
+#include "zdtmtst.h"
+
+const char *test_doc	= "Check that a fifo read-only descriptor is restored with data";
+const char *test_author	= "Andrew Vagin <avagin@openvz.org>";
+
+char *filename;
+TEST_OPTION(filename, string, "file name", 1);
+
+#define BUF_SIZE (16 * 4096) /* A fifo buffer has 16 slots by default */
+
+int main(int argc, char **argv)
+{
+	int fd;
+	int fd_ro;
+	struct stat st;
+	mode_t mode = S_IFIFO | 0700;
+	uint8_t buf[BUF_SIZE];
+	uint32_t crc;
+	int ret;;
+
+	test_init(argc, argv);
+
+	if (mknod(filename, mode, 0)) {
+		err("can't make fifo \"%s\": %m\n", filename);
+		exit(1);
+	}
+
+	fd = open(filename, O_RDWR);
+	if (fd < 0) {
+		err("can't open %s: %m\n", filename);
+		return 1;
+	}
+
+	fd_ro = open(filename, O_RDONLY);
+	if (fd_ro < 0) {
+		err("can't open %s: %m\n", filename);
+		return 1;
+	}
+
+	crc = ~0;
+	datagen(buf, BUF_SIZE, &crc);
+	ret = write(fd, buf, BUF_SIZE);
+	if (ret != BUF_SIZE) {
+		err("write() failed\n");
+		return 1;
+	}
+
+	close(fd);
+
+	test_daemon();
+	test_waitsig();
+
+	ret = read(fd_ro, buf, BUF_SIZE);
+	if (ret != BUF_SIZE) {
+		err("read() failed\n");
+		return 1;
+	}
+
+	crc = ~0;
+	if (datachk(buf, BUF_SIZE, &crc)) {
+		fail("data corrupted\n");
+		return 1;
+	}
+
+	if (close(fd_ro) < 0) {
+		fail("can't close %s: %m", filename);
+		return 1;
+	}
+
+	if (stat(filename, &st) < 0) {
+		fail("can't stat %s: %m", filename);
+		return 1;
+	}
+
+	if (st.st_mode != mode) {
+		fail("%s is no longer the fifo we had", filename);
+		return 1;
+	}
+
+	if (unlink(filename) < 0) {
+		fail("can't unlink %s: %m", filename);
+		return 1;
+	}
+
+	pass();
+	return 0;
+}