zdtm/tempfs: check that overmounted parts are restored (v2)

v2: check that plain file opened on tempfs
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

test/zdtm.sh

@@ -122,6 +122,7 @@ static/pty03
 static/mountpoints
 ns/static/session00
 ns/static/session01
+ns/static/tempfs
 static/utsname
 static/ipc_namespace
 static/shm
@@ -156,6 +157,7 @@ chroot-file
 rtc
 tempfs
 maps007
+tempfs
 "
 
 source $(readlink -f `dirname $0`/env.sh) || exit 1

test/zdtm/live/static/tempfs.c

@@ -4,6 +4,7 @@
 #include <unistd.h>
 #include <sys/mount.h>
 #include <sys/stat.h>
+#include <linux/limits.h>
 
 #include "zdtmtst.h"
 
@@ -14,11 +15,12 @@ char *dirname;
 TEST_OPTION(dirname, string, "directory name", 1);
 
 #define TEST_WORD	"testtest"
+#define TEST_WORD2	"TESTTEST"
 
 int main(int argc, char **argv)
 {
-	int fd, ret = 1;
-	char buf[1024];
+	int fd, fdo, ret = 1;
+	char buf[1024], fname[PATH_MAX], overmount[PATH_MAX];
 
 	test_init(argc, argv);
 
@@ -28,43 +30,82 @@ int main(int argc, char **argv)
 		return 1;
 	}
 
-	snprintf(buf, sizeof(buf), "%s/test", dirname);
-	fd = open(buf, O_RDWR | O_CREAT);
+	snprintf(fname, sizeof(buf), "%s/test.file", dirname);
+	fdo = open(fname, O_RDWR | O_CREAT);
+	if (fdo < 0) {
+		err("open failed");
+		goto err;
+	}
+
+	if (write(fdo, TEST_WORD, sizeof(TEST_WORD)) != sizeof(TEST_WORD)) {
+		err("write() failed");
+		goto err;
+	}
+
+	snprintf(overmount, sizeof(buf), "%s/test", dirname);
+	mkdir(overmount, 0700);
+
+	snprintf(fname, sizeof(buf), "%s/test.file", overmount);
+	fd = open(fname, O_RDWR | O_CREAT);
 	if (fd < 0) {
 		err("open failed");
-		goto outum;
+		goto err;
 	}
 
-	if (write(fd, TEST_WORD, sizeof(TEST_WORD)) != sizeof(TEST_WORD)) {
+	if (write(fd, TEST_WORD2, sizeof(TEST_WORD2)) != sizeof(TEST_WORD2)) {
 		err("write() failed");
-		goto outuc;
+		goto err;
+	}
+	close(fd);
+
+	if (mount("none", overmount, "tmpfs", 0, "") < 0) {
+		fail("Can't mount tmpfs");
+		goto err;
 	}
 
 	test_daemon();
 	test_waitsig();
 
-	if (lseek(fd, 0, SEEK_SET) < 0) {
-		fail("Seek failed");
-		goto outuc;
+	if (umount(overmount) < 0) {
+		fail("Can't mount tmpfs");
+		goto err;
 	}
 
+	lseek(fdo, 0, SEEK_SET);
 	buf[sizeof(TEST_WORD) + 1] = '\0';
-	if (read(fd, buf, sizeof(TEST_WORD)) != sizeof(TEST_WORD)) {
+	if (read(fdo, buf, sizeof(TEST_WORD)) != sizeof(TEST_WORD)) {
 		fail("Read failed");
-		goto outuc;
+		goto err;
 	}
+	close(fdo);
 
 	if (strcmp(buf, TEST_WORD)) {
 		fail("File corrupted");
-		goto outuc;
+		goto err;
+	}
+
+	fd = open(fname, O_RDONLY);
+	if (fd < 0) {
+		err("open failed");
+		goto err;
+	}
+
+	buf[sizeof(TEST_WORD2) + 1] = '\0';
+	if (read(fd, buf, sizeof(TEST_WORD2)) != sizeof(TEST_WORD2)) {
+		fail("Read failed");
+		goto err;
+	}
+	close(fd);
+
+	if (strcmp(buf, TEST_WORD2)) {
+		fail("File corrupted");
+		goto err;
 	}
 
 	pass();
 	ret = 0;
-outuc:
-	close(fd);
-outum:
-	umount(dirname);
+err:
+	umount2(dirname, MNT_DETACH);
 	rmdir(dirname);
 	return ret;
 }