[PATCH 3/3] test: dirfs: use ramfs rather than devfs

[Sascha Hauer]

devfs as a filesystem is going away, so do not use it in the dirfd test.
Switch to ramfs, but this means we have to mount it ourselves. This
has the advantage though that it might reveal some bugs in the fs layer.

Signed-off-by: Sascha Hauer <s.hauer at pengutronix.de>
---
 test/self/dirfd.c | 46 +++++++++++++++++++++++++++++++++-------------
 1 file changed, 33 insertions(+), 13 deletions(-)

diff --git a/test/self/dirfd.c b/test/self/dirfd.c
index 1f9b375e84ffa948a511b7ad94cd40fabeee4af3..04cbf6e285f3184f3e5b1680271aabffc272c8be 100644
--- a/test/self/dirfd.c
+++ b/test/self/dirfd.c
@@ -9,6 +9,7 @@
 #include <linux/bitfield.h>
 #include <unistd.h>
 #include <bselftest.h>
+#include <libfile.h>
 
 BSELFTEST_GLOBALS();
 
@@ -26,7 +27,7 @@ BSELFTEST_GLOBALS();
 
 static void check_statat(const char *at, int dirfd, const char *prefix, unsigned expected)
 {
-	static const char *paths[] = { ".", "..", "zero", "dev" };
+	static const char *paths[] = { ".", "..", "testfile", "dirfdtest" };
 	struct stat s;
 
 	for (int i = 0; i < ARRAY_SIZE(paths); i++) {
@@ -63,9 +64,9 @@ static void check_statat(const char *at, int dirfd, const char *prefix, unsigned
 			    fullpath, at, testpath))
 			goto next;
 
-		ret = strcmp_ptr(fsdev1->path, "/dev");
+		ret = strcmp_ptr(fsdev1->path, "/dirfdtest");
 		if (!expect(ret == 0, FIELD_GET(BIT(0), expected),
-			    "fsdev_of(%s)->path = %s != /dev", fullpath, fsdev1->path))
+			    "fsdev_of(%s)->path = %s != /dirfdtest", fullpath, fsdev1->path))
 			goto next;
 
 next:
@@ -84,9 +85,9 @@ static void do_test_dirfd(const char *at, int dirfd,
 
 	check_statat(at, dirfd, "",             expected1);
 	check_statat(at, dirfd, "./",           expected1);
-	check_statat(at, dirfd, "/dev/",        expected2);
-	check_statat(at, dirfd, "/dev/./",      expected2);
-	check_statat(at, dirfd, "/dev/../dev/", expected2);
+	check_statat(at, dirfd, "/dirfdtest/",        expected2);
+	check_statat(at, dirfd, "/dirfdtest/./",      expected2);
+	check_statat(at, dirfd, "/dirfdtest/../dirfdtest/", expected2);
 	check_statat(at, dirfd, "/",            expected3);
 	check_statat(at, dirfd, "../",          expected4);
 
@@ -97,19 +98,31 @@ static void do_test_dirfd(const char *at, int dirfd,
 
 static void test_dirfd(void)
 {
-	int fd;
+	int fd, ret;
 
 	fd = open("/", O_PATH | O_DIRECTORY);
-	if (expect(fd < 0, false, "open(/, O_PATH | O_DIRECTORY) = %d", fd))
+	if (!expect(fd < 0, false, "open(/, O_PATH | O_DIRECTORY) = %d", fd))
 		close(fd);
 
+	ret = make_directory("/dirfdtest");
+	if (!expect(ret == 0, true, "make_directory(\"/dirfdtest\") = %d", ret))
+		return;
+
+	ret = mount("none", "ramfs", "/dirfdtest", NULL);
+	if (!expect(ret == 0, true, "mount(\"none\", \"ramfs\", \"/dirfdtest\") = %d", ret))
+		goto out;
+
+	ret = write_file("/dirfdtest/testfile", __func__, strlen(__func__));
+	if (!expect(ret == 0, true, "write_file() = %d", ret))
+		goto out;
+
 #define B(dot, dotdot, zero, dev) 0b##dev##zero##dotdot##dot
 	/* We do fiften tests for every configuration
-	 * for dir in ./ /dev / ../ ; do
-	 *	for file in . .. zero dev ; do
+	 * for dir in ./ /dirfdtest / ../ ; do
+	 *	for file in . .. zero dirfdtest ; do
 	 *		test if file exists
 	 *		test if file can be canonicalized
-	 *		test if parent FS is mounted at /dev
+	 *		test if parent FS is mounted at /dirfdtest
 	 *	done
 	 * done
 	 *
@@ -119,11 +132,18 @@ static void test_dirfd(void)
 	do_test_dirfd("AT_FDCWD", AT_FDCWD,
 		      B(110,110,000,111), B(111,110,111,000),
 		      B(110,110,000,111), B(110,110,000,111));
-	do_test_dirfd("/dev", open("/dev", O_PATH | O_DIRECTORY),
+	do_test_dirfd("/dirfdtest", open("/dirfdtest", O_PATH | O_DIRECTORY),
 		      B(111,110,111,000), B(111,110,111,000),
 		      B(110,110,000,111), B(110,110,000,111));
-	do_test_dirfd("/dev O_CHROOT", open("/dev", O_PATH | O_CHROOT),
+	do_test_dirfd("/dirfdtest O_CHROOT", open("/dirfdtest", O_PATH | O_CHROOT),
 		      B(111,111,111,000), B(000,000,000,000),
 		      B(111,111,111,000), B(111,111,111,000));
+
+out:
+	ret = umount("/dirfdtest");
+	expect(ret == 0, true, "umount(\"/dirfdtest\") = %d", ret);
+
+	ret = rmdir("/dirfdtest");
+	expect(ret == 0, true, "rmdir(\"/dirfdtest\") = %d", ret);
 }
 bselftest(core, test_dirfd);

-- 
2.47.3