// SPDX-License-Identifier: GPL-2.0-or-later
#define _GNU_SOURCE
#include <assert.h>
#include <stddef.h>
#include <sched.h>
#include <fcntl.h>
#include <sys/param.h>
#include <sys/mount.h>
#include <sys/stat.h>
#include <sys/statfs.h>
#include <linux/stat.h>
#include "statmount.h"
#include "../../kselftest.h"
static const char *const known_fs[] = {
"9p", "adfs", "affs", "afs", "aio", "anon_inodefs", "apparmorfs",
"autofs", "bcachefs", "bdev", "befs", "bfs", "binder", "binfmt_misc",
"bpf", "btrfs", "btrfs_test_fs", "ceph", "cgroup", "cgroup2", "cifs",
"coda", "configfs", "cpuset", "cramfs", "cxl", "dax", "debugfs",
"devpts", "devtmpfs", "dmabuf", "drm", "ecryptfs", "efivarfs", "efs",
"erofs", "exfat", "ext2", "ext3", "ext4", "f2fs", "functionfs",
"fuse", "fuseblk", "fusectl", "gadgetfs", "gfs2", "gfs2meta", "hfs",
"hfsplus", "hostfs", "hpfs", "hugetlbfs", "ibmasmfs", "iomem",
"ipathfs", "iso9660", "jffs2", "jfs", "minix", "mqueue", "msdos",
"nfs", "nfs4", "nfsd", "nilfs2", "nsfs", "ntfs", "ntfs3", "ocfs2",
"ocfs2_dlmfs", "ocxlflash", "omfs", "openpromfs", "overlay", "pipefs",
"proc", "pstore", "pvfs2", "qnx4", "qnx6", "ramfs", "reiserfs",
"resctrl", "romfs", "rootfs", "rpc_pipefs", "s390_hypfs", "secretmem",
"securityfs", "selinuxfs", "smackfs", "smb3", "sockfs", "spufs",
"squashfs", "sysfs", "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)
{
size_t bufsize = 1 << 15;
struct statmount *buf = NULL, *tmp = alloca(bufsize);
int tofree = 0;
int ret;
for (;;) {
ret = statmount(mnt_id, 0, mask, tmp, bufsize, flags);
if (ret != -1)
break;
if (tofree)
free(tmp);
if (errno != EOVERFLOW)
return NULL;
bufsize <<= 1;
tofree = 1;
tmp = malloc(bufsize);
if (!tmp)
return NULL;
}
buf = malloc(tmp->size);
if (buf)
memcpy(buf, tmp, tmp->size);
if (tofree)
free(tmp);
return buf;
}
static void write_file(const char *path, const char *val)
{
int fd = open(path, O_WRONLY);
size_t len = strlen(val);
int ret;
if (fd == -1)
ksft_exit_fail_msg("opening %s for write: %s\n", path, strerror(errno));
ret = write(fd, val, len);
if (ret == -1)
ksft_exit_fail_msg("writing to %s: %s\n", path, strerror(errno));
if (ret != len)
ksft_exit_fail_msg("short write to %s\n", path);
ret = close(fd);
if (ret == -1)
ksft_exit_fail_msg("closing %s\n", path);
}
static uint64_t get_mnt_id(const char *name, const char *path, uint64_t mask)
{
struct statx sx;
int ret;
ret = statx(AT_FDCWD, path, 0, mask, &sx);
if (ret == -1)
ksft_exit_fail_msg("retrieving %s mount ID for %s: %s\n",
mask & STATX_MNT_ID_UNIQUE ? "unique" : "old",
name, strerror(errno));
if (!(sx.stx_mask & mask))
ksft_exit_fail_msg("no %s mount ID available for %s\n",
mask & STATX_MNT_ID_UNIQUE ? "unique" : "old",
name);
return sx.stx_mnt_id;
}
static char root_mntpoint[] = "/tmp/statmount_test_root.XXXXXX";
static int orig_root;
static uint64_t root_id, parent_id;
static uint32_t old_root_id, old_parent_id;
static FILE *f_mountinfo;
static void cleanup_namespace(void)
{
int ret;
ret = fchdir(orig_root);
if (ret == -1)
ksft_perror("fchdir to original root");
ret = chroot(".");
if (ret == -1)
ksft_perror("chroot to original root");
umount2(root_mntpoint, MNT_DETACH);
rmdir(root_mntpoint);
}
static void setup_namespace(void)
{
int ret;
char buf[32];
uid_t uid = getuid();
gid_t gid = getgid();
ret = unshare(CLONE_NEWNS|CLONE_NEWUSER|CLONE_NEWPID);
if (ret == -1)
ksft_exit_fail_msg("unsharing mountns and userns: %s\n",
strerror(errno));
sprintf(buf, "0 %d 1", uid);
write_file("/proc/self/uid_map", buf);
write_file("/proc/self/setgroups", "deny");
sprintf(buf, "0 %d 1", gid);
write_file("/proc/self/gid_map", buf);
f_mountinfo = fopen("/proc/self/mountinfo", "re");
if (!f_mountinfo)
ksft_exit_fail_msg("failed to open mountinfo: %s\n",
strerror(errno));
ret = mount("", "/", NULL, MS_REC|MS_PRIVATE, NULL);
if (ret == -1)
ksft_exit_fail_msg("making mount tree private: %s\n",
strerror(errno));
if (!mkdtemp(root_mntpoint))
ksft_exit_fail_msg("creating temporary directory %s: %s\n",
root_mntpoint, strerror(errno));
old_parent_id = get_mnt_id("parent", root_mntpoint, STATX_MNT_ID);
parent_id = get_mnt_id("parent", root_mntpoint, STATX_MNT_ID_UNIQUE);
orig_root = open("/", O_PATH);
if (orig_root == -1)
ksft_exit_fail_msg("opening root directory: %s",
strerror(errno));
atexit(cleanup_namespace);
ret = mount(root_mntpoint, root_mntpoint, NULL, MS_BIND, NULL);
if (ret == -1)
ksft_exit_fail_msg("mounting temp root %s: %s\n",
root_mntpoint, strerror(errno));
ret = chroot(root_mntpoint);
if (ret == -1)
ksft_exit_fail_msg("chroot to temp root %s: %s\n",
root_mntpoint, strerror(errno));
ret = chdir("/");
if (ret == -1)
ksft_exit_fail_msg("chdir to root: %s\n", strerror(errno));
old_root_id = get_mnt_id("root", "/", STATX_MNT_ID);
root_id = get_mnt_id("root", "/", STATX_MNT_ID_UNIQUE);
}
static int setup_mount_tree(int log2_num)
{
int ret, i;
ret = mount("", "/", NULL, MS_REC|MS_SHARED, NULL);
if (ret == -1) {
ksft_test_result_fail("making mount tree shared: %s\n",
strerror(errno));
return -1;
}
for (i = 0; i < log2_num; i++) {
ret = mount("/", "/", NULL, MS_BIND, NULL);
if (ret == -1) {
ksft_test_result_fail("mounting submount %s: %s\n",
root_mntpoint, strerror(errno));
return -1;
}
}
return 0;
}
static void test_listmount_empty_root(void)
{
ssize_t res;
const unsigned int size = 32;
uint64_t list[size];
res = listmount(LSMT_ROOT, 0, 0, list, size, 0);
if (res == -1) {
ksft_test_result_fail("listmount: %s\n", strerror(errno));
return;
}
if (res != 1) {
ksft_test_result_fail("listmount result is %zi != 1\n", res);
return;
}
if (list[0] != root_id) {
ksft_test_result_fail("listmount ID doesn't match 0x%llx != 0x%llx\n",
(unsigned long long) list[0],
(unsigned long long) root_id);
return;
}
ksft_test_result_pass("listmount empty root\n");
}
static void test_statmount_zero_mask(void)
{
struct statmount sm;
int ret;
ret = statmount(root_id, 0, 0, &sm, sizeof(sm), 0);
if (ret == -1) {
ksft_test_result_fail("statmount zero mask: %s\n",
strerror(errno));
return;
}
if (sm.size != sizeof(sm)) {
ksft_test_result_fail("unexpected size: %u != %u\n",
sm.size, (uint32_t) sizeof(sm));
return;
}
if (sm.mask != 0) {
ksft_test_result_fail("unexpected mask: 0x%llx != 0x0\n",
(unsigned long long) sm.mask);
return;
}
ksft_test_result_pass("statmount zero mask\n");
}
static void test_statmount_mnt_basic(void)
{
struct statmount sm;
int ret;
uint64_t mask = STATMOUNT_MNT_BASIC;
ret = statmount(root_id, 0, mask, &sm, sizeof(sm), 0);
if (ret == -1) {
ksft_test_result_fail("statmount mnt basic: %s\n",
strerror(errno));
return;
}
if (sm.size != sizeof(sm)) {
ksft_test_result_fail("unexpected size: %u != %u\n",
sm.size, (uint32_t) sizeof(sm));
return;
}
if (sm.mask != mask) {
ksft_test_result_skip("statmount mnt basic unavailable\n");
return;
}
if (sm.mnt_id != root_id) {
ksft_test_result_fail("unexpected root ID: 0x%llx != 0x%llx\n",
(unsigned long long) sm.mnt_id,
(unsigned long long) root_id);
return;
}
if (sm.mnt_id_old != old_root_id) {
ksft_test_result_fail("unexpected old root ID: %u != %u\n",
sm.mnt_id_old, old_root_id);
return;
}
if (sm.mnt_parent_id != parent_id) {
ksft_test_result_fail("unexpected parent ID: 0x%llx != 0x%llx\n",
(unsigned long long) sm.mnt_parent_id,
(unsigned long long) parent_id);
return;
}
if (sm.mnt_parent_id_old != old_parent_id) {
ksft_test_result_fail("unexpected old parent ID: %u != %u\n",
sm.mnt_parent_id_old, old_parent_id);
return;
}
if (sm.mnt_propagation != MS_PRIVATE) {
ksft_test_result_fail("unexpected propagation: 0x%llx\n",
(unsigned long long) sm.mnt_propagation);
return;
}
ksft_test_result_pass("statmount mnt basic\n");
}
static void test_statmount_sb_basic(void)
{
struct statmount sm;
int ret;
uint64_t mask = STATMOUNT_SB_BASIC;
struct statx sx;
struct statfs sf;
ret = statmount(root_id, 0, mask, &sm, sizeof(sm), 0);
if (ret == -1) {
ksft_test_result_fail("statmount sb basic: %s\n",
strerror(errno));
return;
}
if (sm.size != sizeof(sm)) {
ksft_test_result_fail("unexpected size: %u != %u\n",
sm.size, (uint32_t) sizeof(sm));
return;
}
if (sm.mask != mask) {
ksft_test_result_skip("statmount sb basic unavailable\n");
return;
}
ret = statx(AT_FDCWD, "/", 0, 0, &sx);
if (ret == -1) {
ksft_test_result_fail("stat root failed: %s\n",
strerror(errno));
return;
}
if (sm.sb_dev_major != sx.stx_dev_major ||
sm.sb_dev_minor != sx.stx_dev_minor) {
ksft_test_result_fail("unexpected sb dev %u:%u != %u:%u\n",
sm.sb_dev_major, sm.sb_dev_minor,
sx.stx_dev_major, sx.stx_dev_minor);
return;
}
ret = statfs("/", &sf);
if (ret == -1) {
ksft_test_result_fail("statfs root failed: %s\n",
strerror(errno));
return;
}
if (sm.sb_magic != sf.f_type) {
ksft_test_result_fail("unexpected sb magic: 0x%llx != 0x%lx\n",
(unsigned long long) sm.sb_magic,
sf.f_type);
return;
}
ksft_test_result_pass("statmount sb basic\n");
}
static void test_statmount_mnt_point(void)
{
struct statmount *sm;
sm = statmount_alloc(root_id, STATMOUNT_MNT_POINT, 0);
if (!sm) {
ksft_test_result_fail("statmount mount point: %s\n",
strerror(errno));
return;
}
if (strcmp(sm->str + sm->mnt_point, "/") != 0) {
ksft_test_result_fail("unexpected mount point: '%s' != '/'\n",
sm->str + sm->mnt_point);
goto out;
}
ksft_test_result_pass("statmount mount point\n");
out:
free(sm);
}
static void test_statmount_mnt_root(void)
{
struct statmount *sm;
const char *mnt_root, *last_dir, *last_root;
last_dir = strrchr(root_mntpoint, '/');
assert(last_dir);
last_dir++;
sm = statmount_alloc(root_id, STATMOUNT_MNT_ROOT, 0);
if (!sm) {
ksft_test_result_fail("statmount mount root: %s\n",
strerror(errno));
return;
}
mnt_root = sm->str + sm->mnt_root;
last_root = strrchr(mnt_root, '/');
if (last_root)
last_root++;
else
last_root = mnt_root;
if (strcmp(last_dir, last_root) != 0) {
ksft_test_result_fail("unexpected mount root last component: '%s' != '%s'\n",
last_root, last_dir);
goto out;
}
ksft_test_result_pass("statmount mount root\n");
out:
free(sm);
}
static void test_statmount_fs_type(void)
{
struct statmount *sm;
const char *fs_type;
const char *const *s;
sm = statmount_alloc(root_id, STATMOUNT_FS_TYPE, 0);
if (!sm) {
ksft_test_result_fail("statmount fs type: %s\n",
strerror(errno));
return;
}
fs_type = sm->str + sm->fs_type;
for (s = known_fs; s != NULL; s++) {
if (strcmp(fs_type, *s) == 0)
break;
}
if (!s)
ksft_print_msg("unknown filesystem type: %s\n", fs_type);
ksft_test_result_pass("statmount fs type\n");
free(sm);
}
static void test_statmount_mnt_opts(void)
{
struct statmount *sm;
const char *statmount_opts;
char *line = NULL;
size_t len = 0;
sm = statmount_alloc(root_id, STATMOUNT_MNT_BASIC | STATMOUNT_MNT_OPTS,
0);
if (!sm) {
ksft_test_result_fail("statmount mnt opts: %s\n",
strerror(errno));
return;
}
while (getline(&line, &len, f_mountinfo) != -1) {
int i;
char *p, *p2;
unsigned int old_mnt_id;
old_mnt_id = atoi(line);
if (old_mnt_id != sm->mnt_id_old)
continue;
for (p = line, i = 0; p && i < 5; i++)
p = strchr(p + 1, ' ');
if (!p)
continue;
p2 = strchr(p + 1, ' ');
if (!p2)
continue;
*p2 = '\0';
p = strchr(p2 + 1, '-');
if (!p)
continue;
for (p++, i = 0; p && i < 2; i++)
p = strchr(p + 1, ' ');
if (!p)
continue;
p++;
/* skip generic superblock options */
if (strncmp(p, "ro", 2) == 0)
p += 2;
else if (strncmp(p, "rw", 2) == 0)
p += 2;
if (*p == ',')
p++;
if (strncmp(p, "sync", 4) == 0)
p += 4;
if (*p == ',')
p++;
if (strncmp(p, "dirsync", 7) == 0)
p += 7;
if (*p == ',')
p++;
if (strncmp(p, "lazytime", 8) == 0)
p += 8;
if (*p == ',')
p++;
p2 = strrchr(p, '\n');
if (p2)
*p2 = '\0';
statmount_opts = sm->str + sm->mnt_opts;
if (strcmp(statmount_opts, p) != 0)
ksft_test_result_fail(
"unexpected mount options: '%s' != '%s'\n",
statmount_opts, p);
else
ksft_test_result_pass("statmount mount options\n");
free(sm);
free(line);
return;
}
ksft_test_result_fail("didnt't find mount entry\n");
free(sm);
free(line);
}
static void test_statmount_string(uint64_t mask, size_t off, const char *name)
{
struct statmount *sm;
size_t len, shortsize, exactsize;
uint32_t start, i;
int ret;
sm = statmount_alloc(root_id, mask, 0);
if (!sm) {
ksft_test_result_fail("statmount %s: %s\n", name,
strerror(errno));
goto out;
}
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 != mask) {
ksft_test_result_skip("statmount %s unavailable\n", name);
goto out;
}
len = sm->size - sizeof(*sm);
start = ((uint32_t *) sm)[off];
for (i = start;; i++) {
if (i >= len) {
ksft_test_result_fail("string out of bounds\n");
goto out;
}
if (!sm->str[i])
break;
}
exactsize = sm->size;
shortsize = sizeof(*sm) + i;
ret = statmount(root_id, 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);
if (ret != -1 || errno != EOVERFLOW) {
ksft_test_result_fail("should have failed with EOVERFLOW: %s\n",
strerror(errno));
goto out;
}
ksft_test_result_pass("statmount string %s\n", name);
out:
free(sm);
}
static void test_listmount_tree(void)
{
ssize_t res;
const unsigned int log2_num = 4;
const unsigned int step = 3;
const unsigned int size = (1 << log2_num) + step + 1;
size_t num, expect = 1 << log2_num;
uint64_t list[size];
uint64_t list2[size];
size_t i;
res = setup_mount_tree(log2_num);
if (res == -1)
return;
num = res = listmount(LSMT_ROOT, 0, 0, list, size, 0);
if (res == -1) {
ksft_test_result_fail("listmount: %s\n", strerror(errno));
return;
}
if (num != expect) {
ksft_test_result_fail("listmount result is %zi != %zi\n",
res, expect);
return;
}
for (i = 0; i < size - step;) {
res = listmount(LSMT_ROOT, 0, i ? list2[i - 1] : 0, list2 + i, step, 0);
if (res == -1)
ksft_test_result_fail("short listmount: %s\n",
strerror(errno));
i += res;
if (res < step)
break;
}
if (i != num) {
ksft_test_result_fail("different number of entries: %zu != %zu\n",
i, num);
return;
}
for (i = 0; i < num; i++) {
if (list2[i] != list[i]) {
ksft_test_result_fail("different value for entry %zu: 0x%llx != 0x%llx\n",
i,
(unsigned long long) list2[i],
(unsigned long long) list[i]);
}
}
ksft_test_result_pass("listmount tree\n");
}
#define str_off(memb) (offsetof(struct statmount, memb) / sizeof(uint32_t))
int main(void)
{
int ret;
uint64_t all_mask = STATMOUNT_SB_BASIC | STATMOUNT_MNT_BASIC |
STATMOUNT_PROPAGATE_FROM | STATMOUNT_MNT_ROOT |
STATMOUNT_MNT_POINT | STATMOUNT_FS_TYPE | STATMOUNT_MNT_NS_ID;
ksft_print_header();
ret = statmount(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);
test_listmount_empty_root();
test_statmount_zero_mask();
test_statmount_mnt_basic();
test_statmount_sb_basic();
test_statmount_mnt_root();
test_statmount_mnt_point();
test_statmount_fs_type();
test_statmount_mnt_opts();
test_statmount_string(STATMOUNT_MNT_ROOT, str_off(mnt_root), "mount root");
test_statmount_string(STATMOUNT_MNT_POINT, str_off(mnt_point), "mount point");
test_statmount_string(STATMOUNT_FS_TYPE, str_off(fs_type), "fs type");
test_statmount_string(all_mask, str_off(mnt_root), "mount root & all");
test_statmount_string(all_mask, str_off(mnt_point), "mount point & all");
test_statmount_string(all_mask, str_off(fs_type), "fs type & all");
test_listmount_tree();
if (ksft_get_fail_cnt() + ksft_get_error_cnt() > 0)
ksft_exit_fail();
else
ksft_exit_pass();
}
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