Unverified Commit 0c82fdbb authored by Bhavik Sachdev's avatar Bhavik Sachdev Committed by Christian Brauner
Browse files

selftests: statmount: tests for STATMOUNT_BY_FD 



Add tests for STATMOUNT_BY_FD flag, which adds support for passing a
file descriptors to statmount(). The fd can also be on a "unmounted"
mount (mount unmounted with MNT_DETACH), we also include tests for that.

Co-developed-by: default avatarAndrei Vagin <avagin@gmail.com>
Signed-off-by: default avatarAndrei Vagin <avagin@gmail.com>
Signed-off-by: default avatarBhavik Sachdev <b.sachdev1904@gmail.com>
Link: https://patch.msgid.link/20251129091455.757724-4-b.sachdev1904@gmail.com


Signed-off-by: default avatarChristian Brauner <brauner@kernel.org>
parent 0e503223

tools/testing/selftests/filesystems/statmount/statmount.h

+10 −5
Original line number Diff line number Diff line
@@ -43,20 +43,25 @@ 
	#endif

#endif



static inline int statmount(uint64_t mnt_id, uint64_t mnt_ns_id, uint64_t mask,

			    struct statmount *buf, size_t bufsize,

static inline int statmount(uint64_t mnt_id, uint64_t mnt_ns_id, uint32_t fd,

			    uint64_t mask, struct statmount *buf, size_t bufsize,

			    unsigned int flags)

{

	struct mnt_id_req req = {

		.size = MNT_ID_REQ_SIZE_VER0,

		.mnt_id = mnt_id,

		.param = mask,

	};



	if (flags & STATMOUNT_BY_FD) {

		req.size = MNT_ID_REQ_SIZE_VER1;

		req.mnt_fd = fd;

	} else {

		req.mnt_id = mnt_id;

		if (mnt_ns_id) {

			req.size = MNT_ID_REQ_SIZE_VER1;

			req.mnt_ns_id = mnt_ns_id;

		}

	}



	return syscall(__NR_statmount, &req, buf, bufsize, flags);

}

tools/testing/selftests/filesystems/statmount/statmount_test.c

+246 −15
Original line number Diff line number Diff line
@@ -33,15 +33,24 @@ static const char *const known_fs[] = { 
	"sysv", "tmpfs", "tracefs", "ubifs", "udf", "ufs", "v7", "vboxsf",

	"vfat", "virtiofs", "vxfs", "xenfs", "xfs", "zonefs", NULL };



static struct statmount *statmount_alloc(uint64_t mnt_id, uint64_t mask, unsigned int flags)

static struct statmount *statmount_alloc(uint64_t mnt_id, int fd, uint64_t mask, unsigned int flags)

{

	size_t bufsize = 1 << 15;

	struct statmount *buf = NULL, *tmp = alloca(bufsize);

	struct statmount *buf = NULL, *tmp = NULL;

	int tofree = 0;

	int ret;



	if (flags & STATMOUNT_BY_FD && fd < 0)

		return NULL;



	tmp = alloca(bufsize);



	for (;;) {

		ret = statmount(mnt_id, 0, mask, tmp, bufsize, flags);

		if (flags & STATMOUNT_BY_FD)

			ret = statmount(0, 0, (uint32_t) fd, mask, tmp, bufsize, flags);

		else

			ret = statmount(mnt_id, 0, 0, mask, tmp, bufsize, flags);



		if (ret != -1)

			break;

		if (tofree)
@@ -237,7 +246,7 @@ static void test_statmount_zero_mask(void) 
	struct statmount sm;

	int ret;



	ret = statmount(root_id, 0, 0, &sm, sizeof(sm), 0);

	ret = statmount(root_id, 0, 0, 0, &sm, sizeof(sm), 0);

	if (ret == -1) {

		ksft_test_result_fail("statmount zero mask: %s\n",

				      strerror(errno));
@@ -263,7 +272,7 @@ static void test_statmount_mnt_basic(void) 
	int ret;

	uint64_t mask = STATMOUNT_MNT_BASIC;



	ret = statmount(root_id, 0, mask, &sm, sizeof(sm), 0);

	ret = statmount(root_id, 0, 0, mask, &sm, sizeof(sm), 0);

	if (ret == -1) {

		ksft_test_result_fail("statmount mnt basic: %s\n",

				      strerror(errno));
@@ -323,7 +332,7 @@ static void test_statmount_sb_basic(void) 
	struct statx sx;

	struct statfs sf;



	ret = statmount(root_id, 0, mask, &sm, sizeof(sm), 0);

	ret = statmount(root_id, 0, 0, mask, &sm, sizeof(sm), 0);

	if (ret == -1) {

		ksft_test_result_fail("statmount sb basic: %s\n",

				      strerror(errno));
@@ -375,7 +384,7 @@ static void test_statmount_mnt_point(void) 
{

	struct statmount *sm;



	sm = statmount_alloc(root_id, STATMOUNT_MNT_POINT, 0);

	sm = statmount_alloc(root_id, 0, STATMOUNT_MNT_POINT, 0);

	if (!sm) {

		ksft_test_result_fail("statmount mount point: %s\n",

				      strerror(errno));
@@ -405,7 +414,7 @@ static void test_statmount_mnt_root(void) 
	assert(last_dir);

	last_dir++;



	sm = statmount_alloc(root_id, STATMOUNT_MNT_ROOT, 0);

	sm = statmount_alloc(root_id, 0, STATMOUNT_MNT_ROOT, 0);

	if (!sm) {

		ksft_test_result_fail("statmount mount root: %s\n",

				      strerror(errno));
@@ -438,7 +447,7 @@ static void test_statmount_fs_type(void) 
	const char *fs_type;

	const char *const *s;



	sm = statmount_alloc(root_id, STATMOUNT_FS_TYPE, 0);

	sm = statmount_alloc(root_id, 0, STATMOUNT_FS_TYPE, 0);

	if (!sm) {

		ksft_test_result_fail("statmount fs type: %s\n",

				      strerror(errno));
@@ -467,7 +476,7 @@ static void test_statmount_mnt_opts(void) 
	char *line = NULL;

	size_t len = 0;



	sm = statmount_alloc(root_id, STATMOUNT_MNT_BASIC | STATMOUNT_MNT_OPTS,

	sm = statmount_alloc(root_id, 0, STATMOUNT_MNT_BASIC | STATMOUNT_MNT_OPTS,

			     0);

	if (!sm) {

		ksft_test_result_fail("statmount mnt opts: %s\n",
@@ -557,7 +566,7 @@ static void test_statmount_string(uint64_t mask, size_t off, const char *name) 
	uint32_t start, i;

	int ret;



	sm = statmount_alloc(root_id, mask, 0);

	sm = statmount_alloc(root_id, 0, mask, 0);

	if (!sm) {

		ksft_test_result_fail("statmount %s: %s\n", name,

				      strerror(errno));
@@ -586,14 +595,14 @@ static void test_statmount_string(uint64_t mask, size_t off, const char *name) 
	exactsize = sm->size;

	shortsize = sizeof(*sm) + i;



	ret = statmount(root_id, 0, mask, sm, exactsize, 0);

	ret = statmount(root_id, 0, 0, mask, sm, exactsize, 0);

	if (ret == -1) {

		ksft_test_result_fail("statmount exact size: %s\n",

				      strerror(errno));

		goto out;

	}

	errno = 0;

	ret = statmount(root_id, 0, mask, sm, shortsize, 0);

	ret = statmount(root_id, 0, 0, mask, sm, shortsize, 0);

	if (ret != -1 || errno != EOVERFLOW) {

		ksft_test_result_fail("should have failed with EOVERFLOW: %s\n",

				      strerror(errno));
@@ -658,6 +667,226 @@ static void test_listmount_tree(void) 
	ksft_test_result_pass("listmount tree\n");

}



static void test_statmount_by_fd(void)

{

	struct statmount *sm = NULL;

	char tmpdir[] = "/statmount.fd.XXXXXX";

	const char root[] = "/test";

	char subdir[PATH_MAX], tmproot[PATH_MAX];

	int fd;



	if (!mkdtemp(tmpdir)) {

		ksft_perror("mkdtemp");

		return;

	}



	if (mount("statmount.test", tmpdir, "tmpfs", 0, NULL)) {

		ksft_perror("mount");

		rmdir(tmpdir);

		return;

	}



	snprintf(subdir, PATH_MAX, "%s%s", tmpdir, root);

	snprintf(tmproot, PATH_MAX, "%s/%s", tmpdir, "chroot");



	if (mkdir(subdir, 0755)) {

		ksft_perror("mkdir");

		goto err_tmpdir;

	}



	if (mount(subdir, subdir, NULL, MS_BIND, 0)) {

		ksft_perror("mount");

		goto err_subdir;

	}



	if (mkdir(tmproot, 0755)) {

		ksft_perror("mkdir");

		goto err_subdir;

	}



	fd = open(subdir, O_PATH);

	if (fd < 0) {

		ksft_perror("open");

		goto err_tmproot;

	}



	if (chroot(tmproot)) {

		ksft_perror("chroot");

		goto err_fd;

	}



	sm = statmount_alloc(0, fd, STATMOUNT_MNT_ROOT | STATMOUNT_MNT_POINT, STATMOUNT_BY_FD);

	if (!sm) {

		ksft_test_result_fail("statmount by fd failed: %s\n", strerror(errno));

		goto err_chroot;

	}



	if (sm->size < sizeof(*sm)) {

		ksft_test_result_fail("unexpected size: %u < %u\n",

				      sm->size, (uint32_t) sizeof(*sm));

		goto err_chroot;

	}



	if (sm->mask & STATMOUNT_MNT_POINT) {

		ksft_test_result_fail("STATMOUNT_MNT_POINT unexpectedly set in statmount\n");

		goto err_chroot;

	}



	if (!(sm->mask & STATMOUNT_MNT_ROOT)) {

		ksft_test_result_fail("STATMOUNT_MNT_ROOT not set in statmount\n");

		goto err_chroot;

	}



	if (strcmp(root, sm->str + sm->mnt_root) != 0) {

		ksft_test_result_fail("statmount returned incorrect mnt_root,"

			"statmount mnt_root: %s != %s\n",

			sm->str + sm->mnt_root, root);

		goto err_chroot;

	}



	if (chroot(".")) {

		ksft_perror("chroot");

		goto out;

	}



	free(sm);

	sm = statmount_alloc(0, fd, STATMOUNT_MNT_ROOT | STATMOUNT_MNT_POINT, STATMOUNT_BY_FD);

	if (!sm) {

		ksft_test_result_fail("statmount by fd failed: %s\n", strerror(errno));

		goto err_fd;

	}



	if (sm->size < sizeof(*sm)) {

		ksft_test_result_fail("unexpected size: %u < %u\n",

				      sm->size, (uint32_t) sizeof(*sm));

		goto out;

	}



	if (!(sm->mask & STATMOUNT_MNT_POINT)) {

		ksft_test_result_fail("STATMOUNT_MNT_POINT not set in statmount\n");

		goto out;

	}



	if (!(sm->mask & STATMOUNT_MNT_ROOT)) {

		ksft_test_result_fail("STATMOUNT_MNT_ROOT not set in statmount\n");

		goto out;

	}



	if (strcmp(subdir, sm->str + sm->mnt_point) != 0) {

		ksft_test_result_fail("statmount returned incorrect mnt_point,"

			"statmount mnt_point: %s != %s\n", sm->str + sm->mnt_point, subdir);

		goto out;

	}



	if (strcmp(root, sm->str + sm->mnt_root) != 0) {

		ksft_test_result_fail("statmount returned incorrect mnt_root,"

			"statmount mnt_root: %s != %s\n", sm->str + sm->mnt_root, root);

		goto out;

	}



	ksft_test_result_pass("statmount by fd\n");

	goto out;

err_chroot:

	chroot(".");

out:

	free(sm);

err_fd:

	close(fd);

err_tmproot:

	rmdir(tmproot);

err_subdir:

	umount2(subdir, MNT_DETACH);

	rmdir(subdir);

err_tmpdir:

	umount2(tmpdir, MNT_DETACH);

	rmdir(tmpdir);

}



static void test_statmount_by_fd_unmounted(void)

{

	const char root[] = "/test.unmounted";

	char tmpdir[] = "/statmount.fd.XXXXXX";

	char subdir[PATH_MAX];

	int fd;

	struct statmount *sm = NULL;



	if (!mkdtemp(tmpdir)) {

		ksft_perror("mkdtemp");

		return;

	}



	if (mount("statmount.test", tmpdir, "tmpfs", 0, NULL)) {

		ksft_perror("mount");

		rmdir(tmpdir);

		return;

	}



	snprintf(subdir, PATH_MAX, "%s%s", tmpdir, root);



	if (mkdir(subdir, 0755)) {

		ksft_perror("mkdir");

		goto err_tmpdir;

	}



	if (mount(subdir, subdir, 0, MS_BIND, NULL)) {

		ksft_perror("mount");

		goto err_subdir;

	}



	fd = open(subdir, O_PATH);

	if (fd < 0) {

		ksft_perror("open");

		goto err_subdir;

	}



	if (umount2(tmpdir, MNT_DETACH)) {

		ksft_perror("umount2");

		goto err_fd;

	}



	sm = statmount_alloc(0, fd, STATMOUNT_MNT_POINT | STATMOUNT_MNT_ROOT, STATMOUNT_BY_FD);

	if (!sm) {

		ksft_test_result_fail("statmount by fd unmounted: %s\n",

				      strerror(errno));

		goto err_sm;

	}



	if (sm->size < sizeof(*sm)) {

		ksft_test_result_fail("unexpected size: %u < %u\n",

				      sm->size, (uint32_t) sizeof(*sm));

		goto err_sm;

	}



	if (sm->mask & STATMOUNT_MNT_POINT) {

		ksft_test_result_fail("STATMOUNT_MNT_POINT unexpectedly set in mask\n");

		goto err_sm;

	}



	if (!(sm->mask & STATMOUNT_MNT_ROOT)) {

		ksft_test_result_fail("STATMOUNT_MNT_ROOT not set in mask\n");

		goto err_sm;

	}



	if (strcmp(sm->str + sm->mnt_root, root) != 0) {

		ksft_test_result_fail("statmount returned incorrect mnt_root,"

			"statmount mnt_root: %s != %s\n",

			sm->str + sm->mnt_root, root);

		goto err_sm;

	}



	ksft_test_result_pass("statmount by fd on unmounted mount\n");

err_sm:

	free(sm);

err_fd:

	close(fd);

err_subdir:

	umount2(subdir, MNT_DETACH);

	rmdir(subdir);

err_tmpdir:

	umount2(tmpdir, MNT_DETACH);

	rmdir(tmpdir);

}



#define str_off(memb) (offsetof(struct statmount, memb) / sizeof(uint32_t))



int main(void)
@@ -669,14 +898,14 @@ int main(void) 


	ksft_print_header();



	ret = statmount(0, 0, 0, NULL, 0, 0);

	ret = statmount(0, 0, 0, 0, NULL, 0, 0);

	assert(ret == -1);

	if (errno == ENOSYS)

		ksft_exit_skip("statmount() syscall not supported\n");



	setup_namespace();



	ksft_set_plan(15);

	ksft_set_plan(17);

	test_listmount_empty_root();

	test_statmount_zero_mask();

	test_statmount_mnt_basic();
@@ -693,6 +922,8 @@ int main(void) 
	test_statmount_string(all_mask, str_off(fs_type), "fs type & all");



	test_listmount_tree();

	test_statmount_by_fd_unmounted();

	test_statmount_by_fd();





	if (ksft_get_fail_cnt() + ksft_get_error_cnt() > 0)

tools/testing/selftests/filesystems/statmount/statmount_test_ns.c

+98 −3
Original line number Diff line number Diff line
@@ -102,7 +102,7 @@ static int _test_statmount_mnt_ns_id(void) 
	if (!root_id)

		return NSID_ERROR;



	ret = statmount(root_id, 0, STATMOUNT_MNT_NS_ID, &sm, sizeof(sm), 0);

	ret = statmount(root_id, 0, 0, STATMOUNT_MNT_NS_ID, &sm, sizeof(sm), 0);

	if (ret == -1) {

		ksft_print_msg("statmount mnt ns id: %s\n", strerror(errno));

		return NSID_ERROR;
@@ -128,6 +128,98 @@ static int _test_statmount_mnt_ns_id(void) 
	return NSID_PASS;

}



static int _test_statmount_mnt_ns_id_by_fd(void)

{

	struct statmount sm;

	uint64_t mnt_ns_id;

	int ret, fd, mounted = 1, status = NSID_ERROR;

	char mnt[] = "/statmount.fd.XXXXXX";



	ret = get_mnt_ns_id("/proc/self/ns/mnt", &mnt_ns_id);

	if (ret != NSID_PASS)

		return ret;



	if (!mkdtemp(mnt)) {

		ksft_print_msg("statmount by fd mnt ns id mkdtemp: %s\n", strerror(errno));

		return NSID_ERROR;

	}



	if (mount(mnt, mnt, NULL, MS_BIND, 0)) {

		ksft_print_msg("statmount by fd mnt ns id mount: %s\n", strerror(errno));

		status = NSID_ERROR;

		goto err;

	}



	fd = open(mnt, O_PATH);

	if (fd < 0) {

		ksft_print_msg("statmount by fd mnt ns id open: %s\n", strerror(errno));

		goto err;

	}



	ret = statmount(0, 0, fd, STATMOUNT_MNT_NS_ID, &sm, sizeof(sm), STATMOUNT_BY_FD);

	if (ret == -1) {

		ksft_print_msg("statmount mnt ns id statmount: %s\n", strerror(errno));

		status = NSID_ERROR;

		goto out;

	}



	if (sm.size != sizeof(sm)) {

		ksft_print_msg("unexpected size: %u != %u\n", sm.size,

			       (uint32_t)sizeof(sm));

		status = NSID_FAIL;

		goto out;

	}

	if (sm.mask != STATMOUNT_MNT_NS_ID) {

		ksft_print_msg("statmount mnt ns id unavailable\n");

		status = NSID_SKIP;

		goto out;

	}



	if (sm.mnt_ns_id != mnt_ns_id) {

		ksft_print_msg("unexpected mnt ns ID: 0x%llx != 0x%llx\n",

			       (unsigned long long)sm.mnt_ns_id,

			       (unsigned long long)mnt_ns_id);

		status = NSID_FAIL;

		goto out;

	}



	mounted = 0;

	if (umount2(mnt, MNT_DETACH)) {

		ksft_print_msg("statmount by fd mnt ns id umount2: %s\n", strerror(errno));

		goto out;

	}



	ret = statmount(0, 0, fd, STATMOUNT_MNT_NS_ID, &sm, sizeof(sm), STATMOUNT_BY_FD);

	if (ret == -1) {

		ksft_print_msg("statmount mnt ns id statmount: %s\n", strerror(errno));

		status = NSID_ERROR;

		goto out;

	}



	if (sm.size != sizeof(sm)) {

		ksft_print_msg("unexpected size: %u != %u\n", sm.size,

			       (uint32_t)sizeof(sm));

		status = NSID_FAIL;

		goto out;

	}



	if (sm.mask == STATMOUNT_MNT_NS_ID) {

		ksft_print_msg("unexpected STATMOUNT_MNT_NS_ID in mask\n");

		status = NSID_FAIL;

		goto out;

	}



	status = NSID_PASS;

out:

	close(fd);

	if (mounted)

		umount2(mnt, MNT_DETACH);

err:

	rmdir(mnt);

	return status;

}





static void test_statmount_mnt_ns_id(void)

{

	pid_t pid;
@@ -148,6 +240,9 @@ static void test_statmount_mnt_ns_id(void) 
	if (ret != NSID_PASS)

		exit(ret);

	ret = _test_statmount_mnt_ns_id();

	if (ret != NSID_PASS)

		exit(ret);

	ret = _test_statmount_mnt_ns_id_by_fd();

	exit(ret);

}
@@ -179,7 +274,7 @@ static int validate_external_listmount(pid_t pid, uint64_t child_nr_mounts) 
	for (int i = 0; i < nr_mounts; i++) {

		struct statmount sm;



		ret = statmount(list[i], mnt_ns_id, STATMOUNT_MNT_NS_ID, &sm,

		ret = statmount(list[i], mnt_ns_id, 0, STATMOUNT_MNT_NS_ID, &sm,

				sizeof(sm), 0);

		if (ret < 0) {

			ksft_print_msg("statmount mnt ns id: %s\n", strerror(errno));
@@ -275,7 +370,7 @@ int main(void) 
	int ret;



	ksft_print_header();

	ret = statmount(0, 0, 0, NULL, 0, 0);

	ret = statmount(0, 0, 0, 0, NULL, 0, 0);

	assert(ret == -1);

	if (errno == ENOSYS)

		ksft_exit_skip("statmount() syscall not supported\n");