Re: [PATCH] selftests/filesystems: add fileattr ioctl tests

Dear maintainer,
    We are adding this test because the legacy fileattr ioctls
   (FS_IOC_FSGETXATTR / FS_IOC_FSSETXATTR) are user-visible ABI 
interfaces,but there is no dedicated basic regression test in selftests 
to cover their common behavior. Regressions in these interfaces usually 
affect basic attribute read/write behavior on regular files, 
directories, and other inode types, so add a lightweight selftest here 
as basic protection.

   This patch adds a new test suite under 
tools/testing/selftests/filesystems/fileattr/
   that covers:
     - FS_IOC_FSGETXATTR on regular files
     - FS_IOC_FSGETXATTR on directories
     - FS_IOC_FSGETXATTR on FIFOs (which currently returns ENOTTY)
     - FS_XFLAG_NODUMP round-trips on regular files
     - FS_XFLAG_NOATIME round-trips on regular files

    The test can also run against a caller-selected writable base 
directory via FILEATTR_TEST_DIR, so the same test can be pointed at a 
specific filesystem when needed. If FILEATTR_TEST_DIR is not set, it 
will fall back to /tmp.

    If the maintainers agree with this direction, I would like to 
continue extending this suite to cover more fileattr-related cases and 
inode types, and make it easier to run against different filesystems 
without having to modify the test source for each filesystem.

    I have verified it locally in both ways:
     1. make -C tools/testing/selftests/filesystems/fileattr run_tests
     2. set FILEATTR_TEST_DIR to an absolute path to the test directory,
        then run:
        make -C tools/testing/selftests/filesystems/fileattr run_tests

Thanks,
Baolin

在 2026/8/11 14:32, Baolin Liu 写道:
> From: Baolin Liu <[email protected]>
> 
> Add a selftest for the legacy fileattr ioctls
> (FS_IOC_FSGETXATTR/FS_IOC_FSSETXATTR).
> 
> Cover FS_IOC_FSGETXATTR on regular files, directories,
> and FIFOs, and verify FS_XFLAG_NODUMP and FS_XFLAG_NOATIME
> round-trips on regular files.
> 
> Allow the test to run in a caller-specified writable base
> directory via FILEATTR_TEST_DIR.
> If unset, fall back to P_tmpdir.
> 
> Signed-off-by: Baolin Liu <[email protected]>
> ---
>   tools/testing/selftests/Makefile              |   1 +
>   .../selftests/filesystems/fileattr/.gitignore |   2 +
>   .../selftests/filesystems/fileattr/Makefile   |   6 +
>   .../filesystems/fileattr/fileattr_test.c      | 256 ++++++++++++++++++
>   4 files changed, 265 insertions(+)
>   create mode 100644 tools/testing/selftests/filesystems/fileattr/.gitignore
>   create mode 100644 tools/testing/selftests/filesystems/fileattr/Makefile
>   create mode 100644 tools/testing/selftests/filesystems/fileattr/fileattr_test.c
> 
> diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile
> index 450f13ba4cca..459251b08648 100644
> --- a/tools/testing/selftests/Makefile
> +++ b/tools/testing/selftests/Makefile
> @@ -34,6 +34,7 @@ TARGETS += filesystems
>   TARGETS += filesystems/binderfs
>   TARGETS += filesystems/epoll
>   TARGETS += filesystems/fat
> +TARGETS += filesystems/fileattr
>   TARGETS += filesystems/overlayfs
>   TARGETS += filesystems/statmount
>   TARGETS += filesystems/mount-notify
> diff --git a/tools/testing/selftests/filesystems/fileattr/.gitignore b/tools/testing/selftests/filesystems/fileattr/.gitignore
> new file mode 100644
> index 000000000000..2eaf3e266eb6
> --- /dev/null
> +++ b/tools/testing/selftests/filesystems/fileattr/.gitignore
> @@ -0,0 +1,2 @@
> +# SPDX-License-Identifier: GPL-2.0-only
> +fileattr_test
> diff --git a/tools/testing/selftests/filesystems/fileattr/Makefile b/tools/testing/selftests/filesystems/fileattr/Makefile
> new file mode 100644
> index 000000000000..2295e7c9bdb5
> --- /dev/null
> +++ b/tools/testing/selftests/filesystems/fileattr/Makefile
> @@ -0,0 +1,6 @@
> +# SPDX-License-Identifier: GPL-2.0
> +
> +CFLAGS += -O2 -g -Wall $(KHDR_INCLUDES)
> +TEST_GEN_PROGS := fileattr_test
> +
> +include ../../lib.mk
> diff --git a/tools/testing/selftests/filesystems/fileattr/fileattr_test.c b/tools/testing/selftests/filesystems/fileattr/fileattr_test.c
> new file mode 100644
> index 000000000000..cd6a6681d2f7
> --- /dev/null
> +++ b/tools/testing/selftests/filesystems/fileattr/fileattr_test.c
> @@ -0,0 +1,256 @@
> +// SPDX-License-Identifier: GPL-2.0
> +#define _GNU_SOURCE
> +
> +#include <dirent.h>
> +#include <errno.h>
> +#include <fcntl.h>
> +#include <linux/fs.h>
> +#include <linux/limits.h>
> +#include <stdio.h>
> +#include <stdlib.h>
> +#include <string.h>
> +#include <sys/ioctl.h>
> +#include <sys/stat.h>
> +#include <unistd.h>
> +
> +#include "kselftest_harness.h"
> +
> +FIXTURE(fileattr) {
> +	char workdir[PATH_MAX];
> +};
> +
> +static int open_nofollow(const char *path)
> +{
> +	return open(path, O_RDONLY | O_CLOEXEC | O_NOFOLLOW | O_NONBLOCK);
> +}
> +
> +static int get_xattr(int fd, struct fsxattr *fa)
> +{
> +	memset(fa, 0, sizeof(*fa));
> +	return ioctl(fd, FS_IOC_FSGETXATTR, fa);
> +}
> +
> +static int set_xattr(int fd, struct fsxattr *fa)
> +{
> +	return ioctl(fd, FS_IOC_FSSETXATTR, fa);
> +}
> +
> +static int build_path(char *buf, size_t size, const char *dir, const char *name)
> +{
> +	int ret;
> +
> +	ret = snprintf(buf, size, "%s/%s", dir, name);
> +	if (ret < 0 || ret >= size) {
> +		errno = ENAMETOOLONG;
> +		return -1;
> +	}
> +
> +	return 0;
> +}
> +
> +static int make_workdir(char *workdir, size_t size)
> +{
> +	const char *base = getenv("FILEATTR_TEST_DIR");
> +	int ret;
> +
> +	if (!base || !*base)
> +		base = P_tmpdir;
> +
> +	if (base[0] != '/') {
> +		errno = EINVAL;
> +		return -1;
> +	}
> +
> +	ret = snprintf(workdir, size, "%s/fileattr.XXXXXX", base);
> +	if (ret < 0 || ret >= (int)size) {
> +		errno = ENAMETOOLONG;
> +		return -1;
> +	}
> +
> +	return mkdtemp(workdir) ? 0 : -1;
> +}
> +
> +static int cleanup_workdir(const char *workdir)
> +{
> +	struct dirent *de;
> +	DIR *dir;
> +	int ret;
> +
> +	dir = opendir(workdir);
> +	if (!dir)
> +		return -1;
> +
> +	while ((de = readdir(dir))) {
> +		struct stat st;
> +		char path[PATH_MAX];
> +
> +		if (!strcmp(de->d_name, ".") || !strcmp(de->d_name, ".."))
> +			continue;
> +
> +		ret = build_path(path, sizeof(path), workdir, de->d_name);
> +		if (ret) {
> +			closedir(dir);
> +			return -1;
> +		}
> +
> +		ret = lstat(path, &st);
> +		if (ret) {
> +			closedir(dir);
> +			return -1;
> +		}
> +
> +		if (S_ISDIR(st.st_mode))
> +			ret = rmdir(path);
> +		else
> +			ret = unlink(path);
> +		if (ret) {
> +			closedir(dir);
> +			return -1;
> +		}
> +	}
> +
> +	closedir(dir);
> +	return rmdir(workdir);
> +}
> +
> +FIXTURE_SETUP(fileattr)
> +{
> +	if (make_workdir(self->workdir, sizeof(self->workdir)))
> +		SKIP(return, "failed to create workdir: %s", strerror(errno));
> +}
> +
> +FIXTURE_TEARDOWN(fileattr)
> +{
> +	EXPECT_EQ(cleanup_workdir(self->workdir), 0);
> +}
> +
> +TEST_F(fileattr, get_regular_file)
> +{
> +	char path[PATH_MAX];
> +	struct fsxattr fa;
> +	int fd;
> +
> +	ASSERT_EQ(build_path(path, sizeof(path), self->workdir, "regular.XXXXXX"), 0);
> +
> +	fd = mkstemp(path);
> +	ASSERT_GE(fd, 0);
> +	ASSERT_EQ(close(fd), 0);
> +
> +	fd = open_nofollow(path);
> +	ASSERT_GE(fd, 0);
> +
> +	ASSERT_EQ(get_xattr(fd, &fa), 0);
> +
> +	EXPECT_EQ(close(fd), 0);
> +	EXPECT_EQ(unlink(path), 0);
> +}
> +
> +TEST_F(fileattr, get_directory)
> +{
> +	char template[PATH_MAX];
> +	struct fsxattr fa;
> +	char *dir;
> +	int fd;
> +
> +	ASSERT_EQ(build_path(template, sizeof(template), self->workdir, "dir.XXXXXX"), 0);
> +
> +	dir = mkdtemp(template);
> +	ASSERT_NE(dir, NULL);
> +
> +	fd = open_nofollow(dir);
> +	ASSERT_GE(fd, 0);
> +
> +	ASSERT_EQ(get_xattr(fd, &fa), 0);
> +
> +	EXPECT_EQ(close(fd), 0);
> +	EXPECT_EQ(rmdir(dir), 0);
> +}
> +
> +TEST_F(fileattr, get_fifo)
> +{
> +	char path[PATH_MAX];
> +	struct fsxattr fa;
> +	int fd;
> +
> +	ASSERT_EQ(build_path(path, sizeof(path), self->workdir, "fifo.XXXXXX"), 0);
> +
> +	fd = mkstemp(path);
> +	ASSERT_GE(fd, 0);
> +	ASSERT_EQ(close(fd), 0);
> +	ASSERT_EQ(unlink(path), 0);
> +	ASSERT_EQ(mkfifo(path, 0600), 0);
> +
> +	fd = open_nofollow(path);
> +	ASSERT_GE(fd, 0);
> +
> +	memset(&fa, 0, sizeof(fa));
> +	ASSERT_LT(ioctl(fd, FS_IOC_FSGETXATTR, &fa), 0);
> +	EXPECT_EQ(errno, ENOTTY);
> +
> +	EXPECT_EQ(close(fd), 0);
> +	EXPECT_EQ(unlink(path), 0);
> +}
> +
> +TEST_F(fileattr, set_nodump_roundtrip)
> +{
> +	char path[PATH_MAX];
> +	struct fsxattr fa, orig;
> +	int fd;
> +
> +	ASSERT_EQ(build_path(path, sizeof(path), self->workdir, "nodump.XXXXXX"), 0);
> +
> +	fd = mkstemp(path);
> +	ASSERT_GE(fd, 0);
> +	ASSERT_EQ(close(fd), 0);
> +
> +	fd = open_nofollow(path);
> +	ASSERT_GE(fd, 0);
> +
> +	ASSERT_EQ(get_xattr(fd, &orig), 0);
> +	fa = orig;
> +	fa.fsx_xflags |= FS_XFLAG_NODUMP;
> +	ASSERT_EQ(set_xattr(fd, &fa), 0);
> +	ASSERT_EQ(get_xattr(fd, &fa), 0);
> +	EXPECT_TRUE(fa.fsx_xflags & FS_XFLAG_NODUMP);
> +
> +	fa = orig;
> +	ASSERT_EQ(set_xattr(fd, &fa), 0);
> +	ASSERT_EQ(get_xattr(fd, &fa), 0);
> +	EXPECT_EQ(fa.fsx_xflags, orig.fsx_xflags);
> +
> +	EXPECT_EQ(close(fd), 0);
> +	EXPECT_EQ(unlink(path), 0);
> +}
> +
> +TEST_F(fileattr, set_noatime_roundtrip)
> +{
> +	char path[PATH_MAX];
> +	struct fsxattr fa, orig;
> +	int fd;
> +
> +	ASSERT_EQ(build_path(path, sizeof(path), self->workdir, "noatime.XXXXXX"), 0);
> +
> +	fd = mkstemp(path);
> +	ASSERT_GE(fd, 0);
> +	ASSERT_EQ(close(fd), 0);
> +
> +	fd = open_nofollow(path);
> +	ASSERT_GE(fd, 0);
> +
> +	ASSERT_EQ(get_xattr(fd, &orig), 0);
> +	fa = orig;
> +	fa.fsx_xflags |= FS_XFLAG_NOATIME;
> +	ASSERT_EQ(set_xattr(fd, &fa), 0);
> +	ASSERT_EQ(get_xattr(fd, &fa), 0);
> +	EXPECT_TRUE(fa.fsx_xflags & FS_XFLAG_NOATIME);
> +
> +	fa = orig;
> +	ASSERT_EQ(set_xattr(fd, &fa), 0);
> +	ASSERT_EQ(get_xattr(fd, &fa), 0);
> +	EXPECT_EQ(fa.fsx_xflags, orig.fsx_xflags);
> +
> +	EXPECT_EQ(close(fd), 0);
> +	EXPECT_EQ(unlink(path), 0);
> +}
> +
> +TEST_HARNESS_MAIN