Now that we support exporting mount options, via statmount(), add a test
to validate that it works.
Signed-off-by: Josef Bacik <josef@xxxxxxxxxxxxxx>
---
.../filesystems/statmount/statmount_test.c | 131 +++++++++++++++++-
1 file changed, 130 insertions(+), 1 deletion(-)
diff --git a/tools/testing/selftests/filesystems/statmount/statmount_test.c b/tools/testing/selftests/filesystems/statmount/statmount_test.c
index 4f7023c2de77..96696183d27b 100644
--- a/tools/testing/selftests/filesystems/statmount/statmount_test.c
+++ b/tools/testing/selftests/filesystems/statmount/statmount_test.c
@@ -64,6 +64,20 @@ static struct statmount *statmount_alloc(uint64_t mnt_id, uint64_t mask, unsigne
return buf;
}
+static void read_file(const char *path, void *buf, size_t len)
+{
+ int fd = open(path, O_RDONLY);
+ ssize_t ret;
+
+ if (fd < 0)
+ ksft_exit_fail_msg("opening %s for read: %s\n", path, strerror(errno));
+
+ ret = read(fd, buf, len);
+ if (ret < 0)
+ ksft_exit_fail_msg("reading from %s: %s\n", path, strerror(errno));
+ close(fd);
+}
+
static void write_file(const char *path, const char *val)
{
int fd = open(path, O_WRONLY);
@@ -107,6 +121,8 @@ 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 char proc_mounts_buf[4096];
+static char proc_mountinfo_buf[4096];
static void cleanup_namespace(void)
{
@@ -134,6 +150,11 @@ static void setup_namespace(void)
sprintf(buf, "0 %d 1", gid);
write_file("/proc/self/gid_map", buf);
+ memset(proc_mounts_buf, 0, 4096);
+ memset(proc_mountinfo_buf, 0, 4096);
+ read_file("/proc/self/mounts", proc_mounts_buf, 4095);
+ read_file("/proc/self/mountinfo", proc_mountinfo_buf, 4095);
+
ret = mount("", "/", NULL, MS_REC|MS_PRIVATE, NULL);
if (ret == -1)
ksft_exit_fail_msg("making mount tree private: %s\n",
@@ -435,6 +456,113 @@ static void test_statmount_fs_type(void)
free(sm);
}
+/* Search proc_mountinfo_buf for our mount point. */
+static char *find_mnt_point(void)
+{
+ char buf[256];
+ char *cur, *end;
+
+ snprintf(buf, 256, "%llu", (unsigned long long)old_parent_id);
+ cur = strstr(proc_mountinfo_buf, buf);
+ if (!cur)
+ ksft_exit_fail_msg("couldn't find %llu in /proc/self/mountinfo\n",
+ (unsigned long long)old_parent_id);
+
+ /*
+ * The format is
+ *
+ * <mnt id> <parent mnt id> <device> <parent mnt point> <mnt point>
+ *
+ * We are currently at <mnt id>, we must skip the next 4 columns.
+ */
+ for (int i = 0; i < 4; i++) {
+ cur = strchr(cur, ' ');
+ if (!cur)
+ ksft_exit_fail_msg("/proc/self/mountinfo isn't formatted as expected\n");
+ cur++;
+ }
+
+ /*
+ * We are now positioned right at <mnt point>, find the next space and
+ * \0 it out so we have the mount point isolated.
+ */
+ end = strchr(cur, ' ');
+ if (!end)
+ ksft_exit_fail_msg("/proc/self/mountinfo isn't formatted as expected\n");
+ *end = '\0';
+ return cur;
+}
+
+static void test_statmount_mnt_opts(void)
+{
+ struct statmount *sm;
+ char search_buf[256];
+ const char *opts;
+ const char *statmount_opts;
+ const char *mntpoint;
+ char *end;
+
+ sm = statmount_alloc(root_id, STATMOUNT_MNT_OPTS, 0);
+ if (!sm) {
+ ksft_test_result_fail("statmount mnt opts: %s\n",
+ strerror(errno));
+ return;
+ }
+
+ mntpoint = find_mnt_point();
+ snprintf(search_buf, 256, " %s ", mntpoint);
+
+ /*
+ * This fun bit of string parsing is to extract out the mount options
+ * for our root id. Normally it would be the first entry but we don't
+ * want to rely on on that, so we're going to search for the path
+ * manually. The format is
+ *
+ * <device> <mnt point> <fs type> <mnt options> ...
+ *
+ * We start by searching for <mnt point> and then advancing along until
+ * we get the <mnt options> field.
+ */
+
+ /* Look for the root entry. */
+ opts = strstr(proc_mounts_buf, search_buf);
+ if (!opts)
+ ksft_exit_fail_msg("no mount entry for / in /proc/mounts\n");
+
+ /* Now advance us past that chunk, and into the fstype. */
+ opts += strlen(search_buf);
+
+ /* Now find the next space. */
+ opts = strchr(opts, ' ');
+ if (!opts)
+ ksft_exit_fail_msg("/proc/mounts isn't formatted as expected\n");
+
+ /* Now advance one to the start of where the mount options should be. */
+ opts++;
+
+ /*
+ * Now we go all the way to the end of opts and set that value to \0 so
+ * we can easily strcmp what we got from statmount().
+ *
+ * If the mount options have a space in them this will mess up the test,
+ * but I don't know if that happens anywhere. If this fails on that
+ * then we need to update the test to handle that, but for now I'm going
+ * to pretend lik that never happens.
+ */
+ end = strchr(opts, ' ');
+ if (!end)
+ ksft_exit_fail_msg("/proc/mounts isn't formatted as expected\n");
+ *end = '\0';
+
+ statmount_opts = sm->str + sm->mnt_opts;
+ if (strcmp(statmount_opts, opts) != 0)
+ ksft_test_result_fail("unexpected mount options: '%s' != '%s'\n",
+ statmount_opts, opts);
+ else
+ ksft_test_result_pass("statmount mount options\n");
+ free(sm);
+}
+
static void test_statmount_string(uint64_t mask, size_t off, const char *name)
{
struct statmount *sm;
@@ -561,7 +689,7 @@ int main(void)
setup_namespace();
- ksft_set_plan(14);
+ ksft_set_plan(15);
test_listmount_empty_root();
test_statmount_zero_mask();
test_statmount_mnt_basic();
@@ -569,6 +697,7 @@ int main(void)
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");
--
2.43.0
