Re: [LTP] [PATCH v4 08/13] Add statmount03 test

[Cyril Hrubis <chrubis@suse.cz>]

Hi!
> This test verifies that statmount() is correctly reading mount
> information (mount id, parent mount id, mount attributes etc.)
> using STATMOUNT_MNT_BASIC.
> 
> Signed-off-by: Andrea Cervesato <andrea.cervesato@suse.com>
> ---
>  runtest/syscalls                                  |   1 +
>  testcases/kernel/syscalls/statmount/.gitignore    |   1 +
>  testcases/kernel/syscalls/statmount/statmount.h   |  24 ++++
>  testcases/kernel/syscalls/statmount/statmount03.c | 137 ++++++++++++++++++++++
>  4 files changed, 163 insertions(+)
> 
> diff --git a/runtest/syscalls b/runtest/syscalls
> index e028baf19..ec11a3a21 100644
> --- a/runtest/syscalls
> +++ b/runtest/syscalls
> @@ -1570,6 +1570,7 @@ stat04_64 stat04_64
>  
>  statmount01 statmount01
>  statmount02 statmount02
> +statmount03 statmount03
>  
>  statfs01 statfs01
>  statfs01_64 statfs01_64
> diff --git a/testcases/kernel/syscalls/statmount/.gitignore b/testcases/kernel/syscalls/statmount/.gitignore
> index a30b9565f..2a02bf721 100644
> --- a/testcases/kernel/syscalls/statmount/.gitignore
> +++ b/testcases/kernel/syscalls/statmount/.gitignore
> @@ -1,2 +1,3 @@
>  statmount01
>  statmount02
> +statmount03
> diff --git a/testcases/kernel/syscalls/statmount/statmount.h b/testcases/kernel/syscalls/statmount/statmount.h
> index e807c8288..5cd54242c 100644
> --- a/testcases/kernel/syscalls/statmount/statmount.h
> +++ b/testcases/kernel/syscalls/statmount/statmount.h
> @@ -10,6 +10,7 @@
>  #include "tst_test.h"
>  #include "lapi/mount.h"
>  #include "lapi/syscalls.h"
> +#include "tst_safe_stdio.h"
>  
>  static inline int statmount(uint64_t mnt_id, uint64_t mask, struct statmount *buf,
>  		     size_t bufsize, unsigned int flags)
> @@ -23,4 +24,27 @@ static inline int statmount(uint64_t mnt_id, uint64_t mask, struct statmount *bu
>  	return tst_syscall(__NR_statmount, &req, buf, bufsize, flags);
>  }
>  
> +static inline int read_peer_group(const char *path)
> +{
> +	FILE *file;
> +	char line[PATH_MAX];
> +	char mroot[PATH_MAX];
> +	int group = -1;
> +
> +	file = SAFE_FOPEN("/proc/self/mountinfo", "r");
> +
> +	while (fgets(line, sizeof(line), file)) {
> +		if (sscanf(line, "%*d %*d %*d:%*d %s %*s %*s shared:%d", mroot, &group) != 2)
> +			continue;
> +
> +		if (strcmp(mroot, path) == 0)
> +			break;
> +	}
> +
> +	if (group == -1)
> +		tst_brk(TBROK, "Can't reed peer group ID for %s", path);
> +
> +	return group;
> +}
> +
>  #endif
> diff --git a/testcases/kernel/syscalls/statmount/statmount03.c b/testcases/kernel/syscalls/statmount/statmount03.c
> new file mode 100644
> index 000000000..634c4b447
> --- /dev/null
> +++ b/testcases/kernel/syscalls/statmount/statmount03.c
> @@ -0,0 +1,137 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * Copyright (C) 2024 SUSE LLC Andrea Cervesato <andrea.cervesato@suse.com>
> + */
> +
> +/*\
> + * [Description]
> + *
> + * This test verifies that statmount() is correctly reading mount information
> + * (mount id, parent mount id, mount attributes etc.) using STATMOUNT_MNT_BASIC.
> + *
> + * [Algorithm]
> + *
> + * - create a mount point
> + * - create a new parent folder inside the mount point and obtain its mount info
> + * - create the new "/" mount folder and obtain its mount info
> + * - run statmount() on the mount point using STATMOUNT_MNT_BASIC
> + * - read results and check if mount info are correct
> + */
> +
> +#define _GNU_SOURCE
> +
> +#include "statmount.h"
> +#include "lapi/stat.h"
> +#include "lapi/sched.h"
> +
> +#define DIR_A "LTP_DIR_A"
> +#define DIR_B "LTP_DIR_B"
> +
> +static uint64_t mnt_id;
> +static uint64_t mnt_id_old;
> +static uint64_t parent_id;
> +static uint64_t parent_id_old;
> +static uint64_t mnt_peer_group;
> +static uint64_t mnt_master;
> +static struct statmount *st_mount;
> +
> +static void read_mnt_id(
> +	const char *path,
> +	uint64_t *mnt_id,
> +	uint64_t *mnt_id_unique)
> +{
> +	struct ltp_statx sx;
> +
> +	if (mnt_id) {
> +		SAFE_STATX(AT_FDCWD, path, 0, STATX_MNT_ID, &sx);
> +		*mnt_id = sx.data.stx_mnt_id;
> +	}
> +
> +	if (mnt_id_unique) {
> +		SAFE_STATX(AT_FDCWD, path, 0, STATX_MNT_ID_UNIQUE, &sx);
> +		*mnt_id_unique = sx.data.stx_mnt_id;
> +	}

Technically the stx_mnt_id is only valid if the sx.data.stx_mask has the
STATX_MNT_ID or STATX_MNT_ID_UNIQUE set when statx() returns.

We have min_kver set to 6.8 so this should always work, but it wouldn't
hurt to double check.

> +}
> +
> +static struct tcase {
> +	uint64_t prop_type;
> +	char *msg;
> +} tcases[] = {
> +	{ MS_PRIVATE, TST_TO_STR_(MS_PRIVATE) },
> +	{ MS_SHARED, TST_TO_STR_(MS_SHARED) },
> +	{ MS_SLAVE, TST_TO_STR_(MS_SLAVE) },
> +	{ MS_UNBINDABLE, TST_TO_STR_(MS_UNBINDABLE) },
> +};
> +
> +static void run(unsigned int i)
> +{
> +	struct tcase *tc = &tcases[i];
> +
> +	tst_res(TINFO,  "Testing statmount() on %s", tc->msg);
> +
> +	SAFE_MOUNT(DIR_B, DIR_A, "none", MS_BIND, NULL);
> +	SAFE_MOUNT("none", DIR_A, "none", tc->prop_type, NULL);
> +	read_mnt_id(DIR_A, &mnt_id_old, &mnt_id);
> +
> +	memset(st_mount, 0, sizeof(struct statmount));
> +
> +	TST_EXP_PASS(statmount(mnt_id, STATMOUNT_MNT_BASIC, st_mount,
> +		sizeof(struct statmount), 0));
> +
> +	SAFE_UMOUNT(DIR_A);
> +
> +	if (TST_RET == -1)
> +		return;

Here as well if (!TST_PASS)

> +	/* s->sm.mnt_peer_group = IS_MNT_SHARED(m) ? m->mnt_group_id : 0;
> +	 * s->sm.mnt_master = IS_MNT_SLAVE(m) ? m->mnt_master->mnt_group_id : 0;
> +	 */

This comment looks like a leftover.

> +	mnt_peer_group = tc->prop_type == MS_SHARED ? read_peer_group(DIR_A) : 0;
> +	mnt_master = tc->prop_type == MS_SLAVE ? read_peer_group(DIR_A) : 0;
> +
> +	TST_EXP_EQ_LI(st_mount->mask, STATMOUNT_MNT_BASIC);
> +	TST_EXP_EQ_LI(st_mount->size, sizeof(struct statmount));
> +	TST_EXP_EQ_LI(st_mount->mnt_id, mnt_id);
> +	TST_EXP_EQ_LI(st_mount->mnt_id_old, mnt_id_old);
> +	TST_EXP_EQ_LI(st_mount->mnt_parent_id, parent_id);
> +	TST_EXP_EQ_LI(st_mount->mnt_parent_id_old, parent_id_old);
> +	TST_EXP_EQ_LU(st_mount->mnt_propagation & tc->prop_type, tc->prop_type);
> +	TST_EXP_EQ_LI(st_mount->mnt_master, mnt_master);
> +	TST_EXP_EQ_LI(st_mount->mnt_peer_group, mnt_peer_group);
> +}

Otherwise it looks good:

Reviewed-by: Cyril Hrubis <chrubis@suse.cz>

-- 
Cyril Hrubis
chrubis@suse.cz

-- 
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