zdtm: add a test on open symlink migration

Signed-off-by: Pavel Tikhomirov <ptikhomirov@virtuozzo.com>
Co-Developed-by: Vitaly Ostrosablin <vostrosablin@virtuozzo.com>
Signed-off-by: Vitaly Ostrosablin <vostrosablin@virtuozzo.com>
Signed-off-by: Alexander Mikhalitsyn (Virtuozzo) <alexander@mihalicyn.com>

test/zdtm/static/Makefile

@@ -364,6 +364,8 @@ TST_DIR		=				\
 		ghost_on_rofs			\
 		overmounted_file		\
 		opath_file			\
+		symlink				\
+		symlink01			\
 
 TST_DIR_FILE	=				\
 		chroot				\
@@ -539,6 +541,7 @@ clone_fs:		LDLIBS += -pthread
 # we have to explicitly specify both .o and .d for this case:
 netns_sub_veth.o netns_sub_veth.d: CPPFLAGS += $(call pkg-cflags, libnl-3.0)
 netns_sub_veth:		LDLIBS += $(call pkg-libs, libnl-route-3.0 libnl-3.0)
+symlink01:		CFLAGS += -DZDTM_UNLINK_SYMLINK
 
 socket-tcp-fin-wait1:	CFLAGS += -D ZDTM_TCP_FIN_WAIT1
 socket-tcp-fin-wait2:	CFLAGS += -D ZDTM_TCP_FIN_WAIT2

test/zdtm/static/opath_file.c

@@ -36,7 +36,7 @@ static int parse_self_fdinfo(int fd, struct fdinfo *fi)
 
 	while (fgets(line, sizeof(line), file)) {
 		if (fdinfo_field(line, "flags")) {
-			if (sscanf(line, "%*s %llu", &val) != 1) {
+			if (sscanf(line, "%*s %llo", &val) != 1) {
 				pr_err("failed to read flags: %s", line);
 				goto fail;
 			}

test/zdtm/static/symlink.c

@@ -0,0 +1,102 @@
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <limits.h>
+
+#include "zdtmtst.h"
+
+#define TEST_FILE "test_file"
+#define TEST_SYMLINK "test_symlink"
+
+const char *test_doc	= "Check open symlink preserved";
+const char *test_author	= "Pavel Tikhomirov <ptikhomirov@virtuozzo.com>";
+
+char *dirname;
+TEST_OPTION(dirname, string, "directory name", 1);
+
+int main(int argc, char **argv)
+{
+	char test_symlink[PATH_MAX];
+	char test_file[PATH_MAX];
+	char pathbuf[PATH_MAX];
+	struct stat stb, sta;
+	int ret, fd;
+
+	test_init(argc, argv);
+
+	if (mkdir(dirname, 0700)) {
+		pr_perror("can't make directory %s", dirname);
+		exit(1);
+	}
+
+	snprintf(test_file, sizeof(test_file), "%s/%s", dirname, TEST_FILE);
+	ret = creat(test_file, 0644);
+	if (ret == -1) {
+		pr_perror("cat't create %s", test_file);
+		return 1;
+	}
+	close(ret);
+
+	snprintf(test_symlink, sizeof(test_symlink), "%s/%s", dirname, TEST_SYMLINK);
+	ret = symlink(test_file, test_symlink);
+	if (ret == -1) {
+		pr_perror("cat't symlink to %s", test_symlink);
+		return 1;
+	}
+
+	fd = open(test_symlink, O_PATH | O_NOFOLLOW);
+	if (fd == -1) {
+		pr_perror("cat't open symlink %s", test_symlink);
+		return 1;
+	}
+
+	ret = fstat(fd, &sta);
+	if (ret == -1) {
+		pr_perror("cat't fstat %s", test_symlink);
+		return 1;
+	}
+
+	if (!S_ISLNK(sta.st_mode)) {
+		pr_perror("file is not symlink %s", test_symlink);
+		return 1;
+	}
+
+#ifdef ZDTM_UNLINK_SYMLINK
+	if (unlink(test_symlink)) {
+		pr_perror("can't unlink symlink %s", test_symlink);
+		return 1;
+	}
+#endif
+
+	test_daemon();
+	test_waitsig();
+
+	ret = fstat(fd, &stb);
+	if (ret == -1) {
+		fail("cat't fstat %s", test_symlink);
+		return 1;
+	}
+
+	if (!S_ISLNK(stb.st_mode)) {
+		fail("file is not symlink %s", test_symlink);
+		return 1;
+	}
+
+	ret = readlinkat(fd, "", pathbuf, sizeof(pathbuf) - 1);
+	if (ret < 0) {
+		fail("Can't readlinkat");
+		return 1;
+	}
+	pathbuf[ret] = 0;
+
+	if (strcmp(test_file, pathbuf)) {
+		fail("symlink points to %s but %s expected", pathbuf, test_file);
+		return 1;
+	}
+
+	close(fd);
+	pass();
+	return 0;
+}

test/zdtm/static/symlink01.c

@@ -0,0 +1 @@
+symlink.c