[LTP] [PATCH v3] syscalls/mount_setattr01: Add basic functional test
Cyril Hrubis
chrubis@suse.cz
Tue Apr 26 14:43:15 CEST 2022
Hi!
> The mount_setattr() system call changes the mount properties of
> a mount or an entire mount tree. Here we check whether the mount
> attributes are set correctly.
>
> Signed-off-by: Dai Shili <daisl.fnst@fujitsu.com>
> Signed-off-by: Chen Hanxiao <chenhx.fnst@fujitsu.com>
> ---
> v3:
> 1) fix doc issue
> 2) fix bugs according to Petr's comments
> v2:
> 1) fix bugs according to Cyril's comments
> 2) just set and test mount attributes, remove attr_clr section.
>
> include/lapi/fsmount.h | 45 ++++++
> runtest/syscalls | 2 +
> .../kernel/syscalls/mount_setattr/.gitignore | 1 +
> .../kernel/syscalls/mount_setattr/Makefile | 6 +
> .../syscalls/mount_setattr/mount_setattr01.c | 135 ++++++++++++++++++
> 5 files changed, 189 insertions(+)
> create mode 100644 testcases/kernel/syscalls/mount_setattr/.gitignore
> create mode 100644 testcases/kernel/syscalls/mount_setattr/Makefile
> create mode 100644 testcases/kernel/syscalls/mount_setattr/mount_setattr01.c
>
> diff --git a/include/lapi/fsmount.h b/include/lapi/fsmount.h
> index 377af85ec..2aa92dc0c 100644
> --- a/include/lapi/fsmount.h
> +++ b/include/lapi/fsmount.h
> @@ -16,6 +16,42 @@
> #include "lapi/fcntl.h"
> #include "lapi/syscalls.h"
>
> +/*
> + * Mount attributes.
> + */
> +#ifndef MOUNT_ATTR_RDONLY
> +# define MOUNT_ATTR_RDONLY 0x00000001 /* Mount read-only */
> +#endif
> +#ifndef MOUNT_ATTR_NOSUID
> +# define MOUNT_ATTR_NOSUID 0x00000002 /* Ignore suid and sgid bits */
> +#endif
> +#ifndef MOUNT_ATTR_NODEV
> +# define MOUNT_ATTR_NODEV 0x00000004 /* Disallow access to device special files */
> +#endif
> +#ifndef MOUNT_ATTR_NOEXEC
> +# define MOUNT_ATTR_NOEXEC 0x00000008 /* Disallow program execution */
> +#endif
> +#ifndef MOUNT_ATTR_NODIRATIME
> +# define MOUNT_ATTR_NODIRATIME 0x00000080 /* Do not update directory access times */
> +#endif
> +#ifndef MOUNT_ATTR_NOSYMFOLLOW
> +# define MOUNT_ATTR_NOSYMFOLLOW 0x00200000 /* Do not follow symlinks */
> +#endif
> +
> +#ifndef ST_NOSYMFOLLOW
> +# define ST_NOSYMFOLLOW 0x2000 /* do not follow symlinks */
> +#endif
> +
> +/*
> + * mount_setattr()
> + */
> +struct mount_attr {
> + uint64_t attr_set;
> + uint64_t attr_clr;
> + uint64_t propagation;
> + uint64_t userns_fd;
> +};
> +
> #ifndef HAVE_FSOPEN
> static inline int fsopen(const char *fsname, unsigned int flags)
> {
> @@ -62,6 +98,15 @@ static inline int open_tree(int dirfd, const char *pathname, unsigned int flags)
> }
> #endif /* HAVE_OPEN_TREE */
>
> +#ifndef HAVE_MOUNT_SETATTR
> +static inline int mount_setattr(int dirfd, const char *from_pathname, unsigned int flags,
> + struct mount_attr *attr, size_t size)
> +{
> + return tst_syscall(__NR_mount_setattr, dirfd, from_pathname, flags,
> + attr, size);
> +}
> +#endif /* HAVE_MOUNT_SETATTR */
> +
> /*
> * New headers added in kernel after 5.2 release, create them for old userspace.
> */
> diff --git a/runtest/syscalls b/runtest/syscalls
> index d43d6983b..307f9bed1 100644
> --- a/runtest/syscalls
> +++ b/runtest/syscalls
> @@ -803,6 +803,8 @@ mount04 mount04
> mount05 mount05
> mount06 mount06
>
> +mount_setattr01 mount_setattr01
> +
> move_mount01 move_mount01
> move_mount02 move_mount02
>
> diff --git a/testcases/kernel/syscalls/mount_setattr/.gitignore b/testcases/kernel/syscalls/mount_setattr/.gitignore
> new file mode 100644
> index 000000000..52a77b9ca
> --- /dev/null
> +++ b/testcases/kernel/syscalls/mount_setattr/.gitignore
> @@ -0,0 +1 @@
> +/mount_setattr01
> diff --git a/testcases/kernel/syscalls/mount_setattr/Makefile b/testcases/kernel/syscalls/mount_setattr/Makefile
> new file mode 100644
> index 000000000..5ea7d67db
> --- /dev/null
> +++ b/testcases/kernel/syscalls/mount_setattr/Makefile
> @@ -0,0 +1,6 @@
> +# SPDX-License-Identifier: GPL-2.0-or-later
> +
> +top_srcdir ?= ../../../..
> +
> +include $(top_srcdir)/include/mk/testcases.mk
> +include $(top_srcdir)/include/mk/generic_leaf_target.mk
> diff --git a/testcases/kernel/syscalls/mount_setattr/mount_setattr01.c b/testcases/kernel/syscalls/mount_setattr/mount_setattr01.c
> new file mode 100644
> index 000000000..f56409a40
> --- /dev/null
> +++ b/testcases/kernel/syscalls/mount_setattr/mount_setattr01.c
> @@ -0,0 +1,135 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * Copyright (c) 2022 FUJITSU LIMITED. All rights reserved.
> + * Author: Dai Shili <daisl.fnst@fujitsu.com>
> + * Author: Chen Hanxiao <chenhx.fnst@fujitsu.com>
> + */
> +
> +/*\
> + * [Description]
> + *
> + * Basic mount_setattr() test.
> + * Test whether the basic mount attributes are set correctly.
> + *
> + * Verify some MOUNT_SETATTR(2) attributes:
> + *
> + * - 1) MOUNT_ATTR_RDONLY - makes the mount read-only
> + * - 2) MOUNT_ATTR_NOSUID - causes the mount not to honor the
> + * set-user-ID and set-group-ID mode bits and file capabilities
> + * when executing programs.
> + * - 3) MOUNT_ATTR_NODEV - prevents access to devices on this mount
> + * - 4) MOUNT_ATTR_NOEXEC - prevents executing programs on this mount
> + * - 5) MOUNT_ATTR_NOSYMFOLLOW - prevents following symbolic links
> + * on this mount
> + * - 6) MOUNT_ATTR_NODIRATIME - prevents updating access time for
> + * directories on this mount
> + *
> + * The functionality was added in v5.12.
> + */
> +
> +#define _GNU_SOURCE
> +
> +#include <sys/statvfs.h>
> +#include "tst_test.h"
> +#include "lapi/fsmount.h"
> +#include "lapi/stat.h"
> +
> +#define MNTPOINT "mntpoint"
> +#define OT_MNTPOINT "ot_mntpoint"
> +#define TCASE_ENTRY(attrs, exp_attrs) \
> + { \
> + .name = #attrs, \
> + .mount_attrs = attrs, \
> + .expect_attrs = exp_attrs \
> + }
> +
> +static int dir_created;
> +static int mount_flag, otfd;
^
This has to be set to -1 here
Otherwise we will close fd 0 in a case that the test did exit before we
opened the fd.
> +static struct tcase {
> + char *name;
> + unsigned int mount_attrs;
> + unsigned int expect_attrs;
> +} tcases[] = {
> + TCASE_ENTRY(MOUNT_ATTR_RDONLY, ST_RDONLY),
> + TCASE_ENTRY(MOUNT_ATTR_NOSUID, ST_NOSUID),
> + TCASE_ENTRY(MOUNT_ATTR_NODEV, ST_NODEV),
> + TCASE_ENTRY(MOUNT_ATTR_NOEXEC, ST_NOEXEC),
> + TCASE_ENTRY(MOUNT_ATTR_NOSYMFOLLOW, ST_NOSYMFOLLOW),
> + TCASE_ENTRY(MOUNT_ATTR_NODIRATIME, ST_NODIRATIME),
> +};
> +
> +static void cleanup(void)
> +{
> + if (otfd > -1)
> + SAFE_CLOSE(otfd);
> + if (mount_flag && tst_is_mounted_at_tmpdir(OT_MNTPOINT)) {
I would simply trust the mount_flag here, no need for the additional
tests.
> + mount_flag = 0;
Also no need to zero the flag here.
> + SAFE_UMOUNT(OT_MNTPOINT);
> + }
This shouldn't be any more complicated than:
if (mount_flag)
SAFE_UMOUNT(OT_MNTPOINT);
> + if (dir_created)
> + SAFE_RMDIR(OT_MNTPOINT);
There is no need remove the directory here, the test library will remove
the temporary directory created for the test recursively.
> +}
> +
> +static void setup(void)
> +{
> + fsopen_supported_by_kernel();
> + SAFE_MKDIR(OT_MNTPOINT, 0777);
> + dir_created = 1;
> +}
> +
> +static void run(unsigned int n)
> +{
> + struct tcase *tc = &tcases[n];
> + struct mount_attr attr = {
> + .attr_set = tc->mount_attrs,
> + };
> + struct statvfs buf;
> +
> + TST_EXP_FD_SILENT(open_tree(AT_FDCWD, MNTPOINT, AT_EMPTY_PATH |
> + AT_SYMLINK_NOFOLLOW | OPEN_TREE_CLOEXEC | OPEN_TREE_CLONE));
> + if (!TST_PASS)
> + goto out;
We can do just return here, no need to do any cleanup here.
> + otfd = (int)TST_RET;
> +
> + TST_EXP_PASS_SILENT(mount_setattr(otfd, "", AT_EMPTY_PATH, &attr, sizeof(attr)),
> + "%s set", tc->name);
> + if (!TST_PASS)
> + return;
And here we should close the file descriptor.
> + TST_EXP_PASS_SILENT(move_mount(otfd, "", AT_FDCWD, OT_MNTPOINT, MOVE_MOUNT_F_EMPTY_PATH));
> + if (!TST_PASS)
> + goto out;
> + mount_flag = 1;
> +
> + TST_EXP_PASS_SILENT(statvfs(OT_MNTPOINT, &buf), "statvfs sucess");
> + if (!TST_PASS)
> + goto out;
> +
> + if (buf.f_flag & tc->expect_attrs)
> + tst_res(TPASS, "%s is actually set as expected", tc->name);
> + else
> + tst_res(TFAIL, "%s is not actually set as expected", tc->name);
> +
> +out:
> + if (otfd > -1)
> + SAFE_CLOSE(otfd);
> +
> + if (tst_is_mounted_at_tmpdir(OT_MNTPOINT)) {
> + mount_flag = 0;
> + SAFE_UMOUNT(OT_MNTPOINT);
> + }
Generally the cleanup here is really messed up. What we do is to put the
cleanup in a reverse order and put goto labels between cleanup steps so
that we don't have to do any checks such as:
...
if (fd < 0)
goto ret0;
...
if (ret < 0)
goto ret1;
...
ret1:
SAFE_UMOUNT(MNTPOINT);
ret0:
SAFE_CLOSE(fd);
> +}
> +
> +static struct tst_test test = {
> + .tcnt = ARRAY_SIZE(tcases),
> + .test = run,
> + .setup = setup,
> + .cleanup = cleanup,
> + .needs_root = 1,
> + .mount_device = 1,
> + .mntpoint = MNTPOINT,
> + .all_filesystems = 1,
> + .skip_filesystems = (const char *const []){"fuse", NULL},
> +};
--
Cyril Hrubis
chrubis@suse.cz
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