zdtm: Add test for cwd ghost directory

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

test/zdtm.sh

@@ -17,6 +17,7 @@ static/pipe01
 static/pipe02
 static/busyloop00
 static/cwd00
+static/cwd01
 static/env00
 static/maps00
 static/maps01

test/zdtm/live/static/Makefile

@@ -153,6 +153,7 @@ TST_FILE	=				\
 
 TST_DIR		=				\
 		cwd00				\
+		cwd01				\
 		overmount_dev			\
 		overmount_file			\
 		overmount_fifo			\

test/zdtm/live/static/cwd01.c

+#include <errno.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <sys/stat.h>
+#include <string.h>
+#include <sys/wait.h>
+
+#include "zdtmtst.h"
+
+const char *test_doc	= "Check that removed cwd works";
+const char *test_author	= "Pavel Emelianov <xemul@parallels.com>";
+
+char *dirname;
+TEST_OPTION(dirname, string, "directory name", 1);
+
+int main(int argc, char **argv)
+{
+	char cwd0[256], cwd1[256], cwd2[256];
+	int pid, p[2], aux;
+
+	test_init(argc, argv);
+
+	pipe(p);
+	pid = fork();
+	if (pid == 0) {
+		close(p[1]);
+		read(p[0], &aux, sizeof(aux));
+		aux = rmdir(dirname);
+		exit(aux ? 1 : 0);
+	}
+
+	if (!getcwd(cwd0, sizeof(cwd0))) {
+		err("can't get cwd: %m\n");
+		exit(1);
+	}
+
+	if (mkdir(dirname, 0700)) {
+		err("can't make directory %s: %m\n", dirname);
+		exit(1);
+	}
+
+	if (chdir(dirname)) {
+		err("can't change directory to %s: %m\n", dirname);
+		goto cleanup;
+	}
+
+	close(p[1]);
+	close(p[0]);
+	waitpid(pid, &aux, 0);
+	if (!WIFEXITED(aux) || WEXITSTATUS(aux) != 0) {
+		err("can't remove dir\n");
+		goto cleanup;
+	}
+
+	aux = readlink("/proc/self/cwd", cwd1, sizeof(cwd1));
+	if (aux < 0) {
+		err("can't get cwd: %m\n");
+		goto cleanup;
+	}
+
+	cwd1[aux] = '\0';
+
+	test_daemon();
+	test_waitsig();
+
+	if (readlink("/proc/self/cwd", cwd2, sizeof(cwd2)) < 0) {
+		fail("can't get cwd: %m\n");
+		goto cleanup;
+	}
+
+	/* FIXME -- criu adds a suffix to removed cwd */
+	if (strncmp(cwd1, cwd2, aux))
+		fail("%s != %s\n", cwd1, cwd2);
+	else
+		pass();
+cleanup:
+	/* return to the initial dir before writing out results */
+	if (chdir(cwd0)) {
+		err("can't change directory to %s: %m\n", cwd0);
+		exit(1);
+	}
+
+	rmdir(dirname);
+	return 0;
+}