tools/testing/selftests/namespaces/listns_test.c
Source file repositories/reference/linux-study-clean/tools/testing/selftests/namespaces/listns_test.c
File Facts
- System
- Linux kernel
- Corpus path
tools/testing/selftests/namespaces/listns_test.c- Extension
.c- Size
- 15034 bytes
- Lines
- 680
- Domain
- Support Tooling And Documentation
- Bucket
- tools
- Inferred role
- Support Tooling And Documentation: implementation source
- Status
- source implementation candidate
Why This File Exists
Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.
- Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.
- Defines or uses C structs; map object ownership, embedded links, reference counts, and lock ownership.
Dependency Surface
errno.hfcntl.hlimits.hsched.hstdio.hstdlib.hstring.hlinux/nsfs.hsys/ioctl.hsys/socket.hsys/stat.hsys/syscall.hsys/types.hsys/wait.hunistd.h../kselftest_harness.h../filesystems/utils.hwrappers.h
Detected Declarations
function listnsfunction listnsfunction listnsfunction listnsfunction listnsfunction listnsfunction listnsfunction listnsfunction listns
Annotated Snippet
if (fd >= 0) {
int ns_type;
/* Verify it's a network namespace via ioctl */
ns_type = ioctl(fd, NS_GET_NSTYPE);
if (ns_type >= 0) {
ASSERT_EQ(ns_type, CLONE_NEWNET);
}
close(fd);
}
}
}
/*
* Test listns() pagination.
* List namespaces in batches.
*/
TEST(listns_pagination)
{
struct ns_id_req req = {
.size = sizeof(req),
.spare = 0,
.ns_id = 0,
.ns_type = 0,
.spare2 = 0,
.user_ns_id = 0,
};
__u64 batch1[2], batch2[2];
ssize_t ret1, ret2;
/* Get first batch */
ret1 = sys_listns(&req, batch1, ARRAY_SIZE(batch1), 0);
if (ret1 < 0) {
if (errno == ENOSYS)
SKIP(return, "listns() not supported");
TH_LOG("listns failed: %s (errno=%d)", strerror(errno), errno);
ASSERT_TRUE(false);
}
ASSERT_GE(ret1, 0);
if (ret1 == 0)
SKIP(return, "No namespaces found");
TH_LOG("First batch: %zd namespaces", ret1);
/* Get second batch using last ID from first batch */
if (ret1 == ARRAY_SIZE(batch1)) {
req.ns_id = batch1[ret1 - 1];
ret2 = sys_listns(&req, batch2, ARRAY_SIZE(batch2), 0);
ASSERT_GE(ret2, 0);
TH_LOG("Second batch: %zd namespaces (after ns_id=%llu)",
ret2, (unsigned long long)req.ns_id);
/* If we got more results, verify IDs are monotonically increasing */
if (ret2 > 0) {
ASSERT_GT(batch2[0], batch1[ret1 - 1]);
TH_LOG("Pagination working: %llu > %llu",
(unsigned long long)batch2[0],
(unsigned long long)batch1[ret1 - 1]);
}
} else {
TH_LOG("All namespaces fit in first batch");
}
}
/*
* Test listns() with LISTNS_CURRENT_USER.
* List namespaces owned by current user namespace.
*/
TEST(listns_current_user)
{
struct ns_id_req req = {
.size = sizeof(req),
.spare = 0,
.ns_id = 0,
.ns_type = 0,
.spare2 = 0,
.user_ns_id = LISTNS_CURRENT_USER,
};
__u64 ns_ids[100];
ssize_t ret;
ret = sys_listns(&req, ns_ids, ARRAY_SIZE(ns_ids), 0);
if (ret < 0) {
if (errno == ENOSYS)
SKIP(return, "listns() not supported");
TH_LOG("listns failed: %s (errno=%d)", strerror(errno), errno);
ASSERT_TRUE(false);
}
ASSERT_GE(ret, 0);
Annotation
- Immediate include surface: `errno.h`, `fcntl.h`, `limits.h`, `sched.h`, `stdio.h`, `stdlib.h`, `string.h`, `linux/nsfs.h`.
- Detected declarations: `function listns`, `function listns`, `function listns`, `function listns`, `function listns`, `function listns`, `function listns`, `function listns`, `function listns`.
- Atlas domain: Support Tooling And Documentation / tools.
- Implementation status: source implementation candidate.
Implementation Notes
- This generated page is the file-by-file coverage layer; curated subsystem chapters should link here when they synthesize a multi-file control flow.
- Core OS pages should be promoted from atlas-only to deep-reviewed when they explain data structures, invariants, locking, lifecycle, and C implementation snippets.
- Driver-family pages are intentionally pattern-oriented unless they are part of the selected PCIe/NVMe representative device path.