[LTP] [PATCH v4] syscalls/newmount: new test case for new mount API

[Cyril Hrubis <chrubis@suse.cz>]

Hi!
>  configure.ac                                  |   1 +
>  include/lapi/newmount.h                       |  95 +++++++++++++++
>  include/lapi/syscalls/aarch64.in              |   4 +
>  include/lapi/syscalls/powerpc64.in            |   4 +
>  include/lapi/syscalls/s390x.in                |   4 +
>  include/lapi/syscalls/x86_64.in               |   4 +
>  m4/ltp-newmount.m4                            |  10 ++
>  runtest/syscalls                              |   2 +
>  testcases/kernel/syscalls/newmount/.gitignore |   1 +
>  testcases/kernel/syscalls/newmount/Makefile   |   9 ++
>  .../kernel/syscalls/newmount/newmount01.c     | 112 ++++++++++++++++++
>  11 files changed, 246 insertions(+)
>  create mode 100644 include/lapi/newmount.h
>  create mode 100644 m4/ltp-newmount.m4
>  create mode 100644 testcases/kernel/syscalls/newmount/.gitignore
>  create mode 100644 testcases/kernel/syscalls/newmount/Makefile
>  create mode 100644 testcases/kernel/syscalls/newmount/newmount01.c
> 
> diff --git a/configure.ac b/configure.ac
> index 50d14967d..28f840c51 100644
> --- a/configure.ac
> +++ b/configure.ac
> @@ -229,6 +229,7 @@ LTP_CHECK_MADVISE
>  LTP_CHECK_MKDTEMP
>  LTP_CHECK_MMSGHDR
>  LTP_CHECK_MREMAP_FIXED
> +LTP_CHECK_NEWMOUNT
>  LTP_CHECK_NOMMU_LINUX
>  LTP_CHECK_PERF_EVENT
>  LTP_CHECK_PRCTL_SUPPORT
> diff --git a/include/lapi/newmount.h b/include/lapi/newmount.h
> new file mode 100644
> index 000000000..13f9fbb9c
> --- /dev/null
> +++ b/include/lapi/newmount.h
> @@ -0,0 +1,95 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * Copyright (C) 2019 Red Hat, Inc.  All rights reserved.
> + * Author: Zorro Lang <zlang@redhat.com>
> + */
> +
> +#ifndef NEWMOUNT_H__
> +#define NEWMOUNT_H__
> +
> +#include <stdint.h>
> +#include <unistd.h>
> +#include "config.h"
> +#include "lapi/syscalls.h"
> +
> +#if !defined(HAVE_FSOPEN)
> +static inline int fsopen(const char *fs_name, unsigned int flags)
> +{
> +	return tst_syscall(__NR_fsopen, fs_name, flags);
> +}
> +
> +/*
> + * fsopen() flags.
> + */
> +#define FSOPEN_CLOEXEC		0x00000001
> +#endif	/* HAVE_FSOPEN */
> +
> +#if !defined(HAVE_FSCONFIG)
> +static inline int fsconfig(int fsfd, unsigned int cmd,
> +                           const char *key, const void *val, int aux)
> +{
> +	return tst_syscall(__NR_fsconfig, fsfd, cmd, key, val, aux);
> +}
> +
> +/*
> + * The type of fsconfig() call made.
> + */
> +enum fsconfig_command {
> +	FSCONFIG_SET_FLAG	= 0,    /* Set parameter, supplying no value */
> +	FSCONFIG_SET_STRING	= 1,    /* Set parameter, supplying a string value */
> +	FSCONFIG_SET_BINARY	= 2,    /* Set parameter, supplying a binary blob value */
> +	FSCONFIG_SET_PATH	= 3,    /* Set parameter, supplying an object by path */
> +	FSCONFIG_SET_PATH_EMPTY	= 4,    /* Set parameter, supplying an object by (empty) path */
> +	FSCONFIG_SET_FD		= 5,    /* Set parameter, supplying an object by fd */
> +	FSCONFIG_CMD_CREATE	= 6,    /* Invoke superblock creation */
> +	FSCONFIG_CMD_RECONFIGURE = 7,   /* Invoke superblock reconfiguration */
> +};
> +#endif	/* HAVE_FSCONFIG */
> +
> +#if !defined(HAVE_FSMOUNT)
> +static inline int fsmount(int fsfd, unsigned int flags, unsigned int ms_flags)
> +{
> +	return tst_syscall(__NR_fsmount, fsfd, flags, ms_flags);
> +}
> +
> +/*
> + * fsmount() flags.
> + */
> +#define FSMOUNT_CLOEXEC		0x00000001
> +
> +/*
> + * Mount attributes.
> + */
> +#define MOUNT_ATTR_RDONLY	0x00000001 /* Mount read-only */
> +#define MOUNT_ATTR_NOSUID	0x00000002 /* Ignore suid and sgid bits */
> +#define MOUNT_ATTR_NODEV	0x00000004 /* Disallow access to device special files */
> +#define MOUNT_ATTR_NOEXEC	0x00000008 /* Disallow program execution */
> +#define MOUNT_ATTR__ATIME	0x00000070 /* Setting on how atime should be updated */
> +#define MOUNT_ATTR_RELATIME	0x00000000 /* - Update atime relative to mtime/ctime. */
> +#define MOUNT_ATTR_NOATIME	0x00000010 /* - Do not update access times. */
> +#define MOUNT_ATTR_STRICTATIME	0x00000020 /* - Always perform atime updates */
> +#define MOUNT_ATTR_NODIRATIME	0x00000080 /* Do not update directory access times */
> +#endif	/* HAVE_FSMOUNT */
> +
> +#if !defined(HAVE_MOVE_MOUNT)
> +static inline int move_mount(int from_dfd, const char *from_pathname,
> +                             int to_dfd, const char *to_pathname,
> +                             unsigned int flags)
> +{
> +	return tst_syscall(__NR_move_mount, from_dfd, from_pathname, to_dfd,
> +	                   to_pathname, flags);
> +}
> +
> +/*
> + * move_mount() flags.
> + */
> +#define MOVE_MOUNT_F_SYMLINKS		0x00000001 /* Follow symlinks on from path */
> +#define MOVE_MOUNT_F_AUTOMOUNTS		0x00000002 /* Follow automounts on from path */
> +#define MOVE_MOUNT_F_EMPTY_PATH		0x00000004 /* Empty from path permitted */
> +#define MOVE_MOUNT_T_SYMLINKS		0x00000010 /* Follow symlinks on to path */
> +#define MOVE_MOUNT_T_AUTOMOUNTS		0x00000020 /* Follow automounts on to path */
> +#define MOVE_MOUNT_T_EMPTY_PATH		0x00000040 /* Empty to path permitted */
> +#define MOVE_MOUNT__MASK		0x00000077
> +#endif	/* HAVE_MOVE_MOUNT */
> +
> +#endif /* NEWMOUNT_H__ */
> diff --git a/include/lapi/syscalls/aarch64.in b/include/lapi/syscalls/aarch64.in
> index 0e00641bc..5b9e1d9a4 100644
> --- a/include/lapi/syscalls/aarch64.in
> +++ b/include/lapi/syscalls/aarch64.in
> @@ -270,4 +270,8 @@ pkey_mprotect 288
>  pkey_alloc 289
>  pkey_free 290
>  pidfd_send_signal 424
> +move_mount 429
> +fsopen 430
> +fsconfig 431
> +fsmount 432
>  _sysctl 1078
> diff --git a/include/lapi/syscalls/powerpc64.in b/include/lapi/syscalls/powerpc64.in
> index 660165d7a..3aaed64e0 100644
> --- a/include/lapi/syscalls/powerpc64.in
> +++ b/include/lapi/syscalls/powerpc64.in
> @@ -359,3 +359,7 @@ pidfd_send_signal 424
>  pkey_mprotect 386
>  pkey_alloc 384
>  pkey_free 385
> +move_mount 429
> +fsopen 430
> +fsconfig 431
> +fsmount 432
> diff --git a/include/lapi/syscalls/s390x.in b/include/lapi/syscalls/s390x.in
> index 7d632d1dc..bd427555a 100644
> --- a/include/lapi/syscalls/s390x.in
> +++ b/include/lapi/syscalls/s390x.in
> @@ -341,3 +341,7 @@ pkey_mprotect 384
>  pkey_alloc 385
>  pkey_free 386
>  pidfd_send_signal 424
> +move_mount 429
> +fsopen 430
> +fsconfig 431
> +fsmount 432
> diff --git a/include/lapi/syscalls/x86_64.in b/include/lapi/syscalls/x86_64.in
> index b1cbd4f2f..94f0b562e 100644
> --- a/include/lapi/syscalls/x86_64.in
> +++ b/include/lapi/syscalls/x86_64.in
> @@ -320,3 +320,7 @@ pkey_alloc 330
>  pkey_free 331
>  statx 332
>  pidfd_send_signal 424
> +move_mount 429
> +fsopen 430
> +fsconfig 431
> +fsmount 432
> diff --git a/m4/ltp-newmount.m4 b/m4/ltp-newmount.m4
> new file mode 100644
> index 000000000..e13a6f0b1
> --- /dev/null
> +++ b/m4/ltp-newmount.m4
> @@ -0,0 +1,10 @@
> +dnl SPDX-License-Identifier: GPL-2.0-or-later
> +dnl Copyright (C) 2019 Red Hat, Inc. All Rights Reserved.
> +
> +AC_DEFUN([LTP_CHECK_NEWMOUNT],[
> +AC_CHECK_FUNCS(fsopen,,)
> +AC_CHECK_FUNCS(fsconfig,,)
> +AC_CHECK_FUNCS(fsmount,,)
> +AC_CHECK_FUNCS(move_mount,,)
> +AC_CHECK_HEADER(sys/mount.h,,,)

There is no point in checking if the sys/mount.h exits, it has been
there for years. You are not using the HAVE_SYS_MOUNT_H macro anywhere in
the code either.

> +])
> diff --git a/runtest/syscalls b/runtest/syscalls
> index fa87ef63f..bd0725977 100644
> --- a/runtest/syscalls
> +++ b/runtest/syscalls
> @@ -794,6 +794,8 @@ nanosleep01 nanosleep01
>  nanosleep02 nanosleep02
>  nanosleep04 nanosleep04
>  
> +newmount01 newmount01

I'm not sure if we shouldn't call the test fsmount01.c since the main
syscall we are testing here is fsmount().

>  nftw01 nftw01
>  nftw6401 nftw6401
>  
> diff --git a/testcases/kernel/syscalls/newmount/.gitignore b/testcases/kernel/syscalls/newmount/.gitignore
> new file mode 100644
> index 000000000..dc78edd5b
> --- /dev/null
> +++ b/testcases/kernel/syscalls/newmount/.gitignore
> @@ -0,0 +1 @@
> +/newmount01
> diff --git a/testcases/kernel/syscalls/newmount/Makefile b/testcases/kernel/syscalls/newmount/Makefile
> new file mode 100644
> index 000000000..7d0920df6
> --- /dev/null
> +++ b/testcases/kernel/syscalls/newmount/Makefile
> @@ -0,0 +1,9 @@
> +# SPDX-License-Identifier: GPL-2.0-or-later
> +#
> +# Copyright (C) 2019 Red Hat, Inc.  All rights reserved.
> +
> +top_srcdir		?= ../../../..
> +
> +include $(top_srcdir)/include/mk/testcases.mk
> +
> +include $(top_srcdir)/include/mk/generic_leaf_target.mk
> diff --git a/testcases/kernel/syscalls/newmount/newmount01.c b/testcases/kernel/syscalls/newmount/newmount01.c
> new file mode 100644
> index 000000000..1e1ff4a78
> --- /dev/null
> +++ b/testcases/kernel/syscalls/newmount/newmount01.c
> @@ -0,0 +1,112 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * Copyright (C) 2019 Red Hat, Inc.  All rights reserved.
> + * Author: Zorro Lang <zlang@redhat.com>
> + *
> + * Use new mount API (fsopen, fsconfig, fsmount, move_mount) to mount
> + * a filesystem without any specified mount options.
> + */
> +
> +#include <stdio.h>
> +#include <stdlib.h>
> +#include <unistd.h>
> +#include <errno.h>
> +#include <sys/mount.h>
> +
> +#include "tst_test.h"
> +#include "lapi/newmount.h"
> +
> +#define LINELENGTH 256
> +#define MNTPOINT "newmount_point"
> +static int sfd, mfd, is_mounted;
> +
> +static int ismount(char *mntpoint)
> +{
> +	int ret = 0;
> +	FILE *file;
> +	char line[LINELENGTH];
> +
> +	file = fopen("/proc/mounts", "r");
> +	if (file == NULL)
> +		tst_brk(TFAIL | TTERRNO, "Open /proc/mounts failed");
> +
> +	while (fgets(line, LINELENGTH, file) != NULL) {
> +		if (strstr(line, mntpoint) != NULL) {
> +			ret = 1;
> +			break;
> +		}
> +	}
> +	fclose(file);
> +	return ret;
> +}
> +
> +static void cleanup(void)
> +{
> +	if (is_mounted) {
> +		TEST(tst_umount(MNTPOINT));
> +		if (TST_RET != 0)
> +			tst_brk(TFAIL | TTERRNO, "umount failed in cleanup");
> +	}
> +}
> +
> +static void test_newmount(void)
> +{
> +	TEST(fsopen(tst_device->fs_type, FSOPEN_CLOEXEC));
> +	if (TST_RET < 0) {
> +		tst_brk(TFAIL | TTERRNO,
> +		        "fsopen %s", tst_device->fs_type);

You can't use tst_brk() with TFAIL at the moment. You should either do
tst_res() followed by return or change the TFAIL to TBROK.

See:

https://github.com/linux-test-project/ltp/issues/462

Also this will likely fail on older kernels that does not support the
syscall. I guess that you will get einval here if the fsopen() is not
implemented in kernel. You have to at least set the min_kver in the
tst_test structure so that the test is skipped on older kernels.

> +	}
> +	sfd = TST_RET;
> +	tst_res(TPASS, "fsopen %s", tst_device->fs_type);
> +
> +	TEST(fsconfig(sfd, FSCONFIG_SET_STRING, "source", tst_device->dev, 0));
> +	if (TST_RET < 0) {
> +		tst_brk(TFAIL | TTERRNO,
> +		        "fsconfig set source to %s", tst_device->dev);

Here as well.

> +	}
> +	tst_res(TPASS, "fsconfig set source to %s", tst_device->dev);
> +
> +
> +	TEST(fsconfig(sfd, FSCONFIG_CMD_CREATE, NULL, NULL, 0));
> +	if (TST_RET < 0) {
> +		tst_brk(TFAIL | TTERRNO,
> +		        "fsconfig create superblock");

And here as well.

> +	}
> +	tst_res(TPASS, "fsconfig create superblock");
> +
> +	TEST(fsmount(sfd, FSMOUNT_CLOEXEC, 0));
> +	if (TST_RET < 0) {
> +		tst_brk(TFAIL | TTERRNO, "fsmount");
> +	}

And here as well.

Also LKML prefers not to have curly braces around single line blocks.

See:
https://www.kernel.org/doc/html/v4.10/process/coding-style.html#placing-braces-and-spaces

> +	mfd = TST_RET;
> +	tst_res(TPASS, "fsmount");
> +	SAFE_CLOSE(sfd);
> +
> +	TEST(move_mount(mfd, "", AT_FDCWD, MNTPOINT, MOVE_MOUNT_F_EMPTY_PATH));
> +	if (TST_RET < 0) {
> +		tst_brk(TFAIL | TTERRNO, "move_mount attach to mount point");
> +	}

Here as well.

> +	is_mounted = 1;
> +	tst_res(TPASS, "move_mount attach to mount point");
> +	SAFE_CLOSE(mfd);
> +
> +	if (ismount(MNTPOINT)) {
> +		tst_res(TPASS, "new mount works");
> +		TEST(tst_umount(MNTPOINT));
> +		if (TST_RET != 0)
> +			tst_brk(TFAIL | TTERRNO, "umount failed");

Here as well.

> +		is_mounted = 0;
> +	} else {
> +		tst_res(TFAIL, "new mount fails");
> +	}
> +}
> +
> +static struct tst_test test = {
> +	.test_all	= test_newmount,
> +	.cleanup	= cleanup,
> +	.needs_root	= 1,
> +	.mntpoint	= MNTPOINT,
> +	.format_device	= 1,
> +	.all_filesystems = 1,
> +	.dev_fs_flags	= TST_FS_SKIP_FUSE,
> +};

-- 
Cyril Hrubis
chrubis@suse.cz