[LTP] [PATCH] hugetlb/hugemmap: add hugemmap33 to test hugetlbfs quota accounting

[LTP] [PATCH] hugetlb/hugemmap: add hugemmap33 to test hugetlbfs quota accounting

[Pavithra]

Test hugetlbfs quota accounting with filesystem size limits to check
for regressions in quota handling for MAP_PRIVATE and MAP_SHARED pages.

Signed-off-by: Pavithra <pavrampu@linux.ibm.com>
---
 runtest/hugetlb                               |   1 +
 testcases/kernel/mem/.gitignore               |   1 +
 .../kernel/mem/hugetlb/hugemmap/hugemmap33.c  | 275 ++++++++++++++++++
 3 files changed, 277 insertions(+)
 create mode 100644 testcases/kernel/mem/hugetlb/hugemmap/hugemmap33.c

diff --git a/runtest/hugetlb b/runtest/hugetlb
index 8ee0e6f82..dbb05a9bc 100644
--- a/runtest/hugetlb
+++ b/runtest/hugetlb
@@ -35,6 +35,7 @@ hugemmap29 hugemmap29
 hugemmap30 hugemmap30
 hugemmap31 hugemmap31
 hugemmap32 hugemmap32
+hugemmap33 hugemmap33
 hugemmap34 hugemmap34
 hugemmap35 hugemmap35
 hugemmap05_1 hugemmap05 -m
diff --git a/testcases/kernel/mem/.gitignore b/testcases/kernel/mem/.gitignore
index 0e59035df..0dd0345c8 100644
--- a/testcases/kernel/mem/.gitignore
+++ b/testcases/kernel/mem/.gitignore
@@ -35,6 +35,7 @@
 /hugetlb/hugemmap/hugemmap30
 /hugetlb/hugemmap/hugemmap31
 /hugetlb/hugemmap/hugemmap32
+/hugetlb/hugemmap/hugemmap33
 /hugetlb/hugemmap/hugemmap34
 /hugetlb/hugemmap/hugemmap35
 /hugetlb/hugeshmat/hugeshmat01
diff --git a/testcases/kernel/mem/hugetlb/hugemmap/hugemmap33.c b/testcases/kernel/mem/hugetlb/hugemmap/hugemmap33.c
new file mode 100644
index 000000000..f5b2a6335
--- /dev/null
+++ b/testcases/kernel/mem/hugetlb/hugemmap/hugemmap33.c
@@ -0,0 +1,275 @@
+// SPDX-License-Identifier: LGPL-2.1-or-later
+/*
+ * Copyright (C) 2005-2007 David Gibson & Adam Litke, IBM Corporation.
+ * Copyright (c) Linux Test Project, 2024
+ * Copyright (C) 2025-2026 Naveed & Pavithra, IBM Corporation.
+ * Assisted with AI tools
+ */
+
+/*\
+ * Test hugetlbfs quota accounting with filesystem size limits.
+ *
+ * The number of global huge pages available to a mounted hugetlbfs filesystem
+ * can be limited using a quota mechanism by setting the size attribute at
+ * mount time. Older kernels did not properly handle quota accounting in a
+ * number of cases (e.g., for MAP_PRIVATE pages, and with MAP_SHARED reservation).
+ *
+ * This test replays some scenarios on a privately mounted filesystem with
+ * quota to check for regressions in hugetlbfs quota accounting.
+ *
+ * Root is required to mount the quota-limited hugetlbfs instance.
+ */
+
+#define _GNU_SOURCE
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <sys/vfs.h>
+#include <sys/statfs.h>
+#include <sys/mount.h>
+
+#include "hugetlb.h"
+
+#define MNTPOINT "hugetlbfs/"
+
+static long hpage_size;
+static int private_resv;
+static char quota_mnt[PATH_MAX];
+static int quota_mounted;
+
+/* map action flags */
+#define ACTION_COW		0x0001
+#define ACTION_TOUCH		0x0002
+
+/* Test result expectations */
+#define EXPECT_SUCCESS	0
+#define EXPECT_SIGNAL	1
+#define EXPECT_FAILURE	2
+
+static void verify_quota_stat(long tot, long free, long avail)
+{
+	struct statfs s;
+
+	SAFE_STATFS(quota_mnt, &s);
+
+	if ((long)s.f_blocks != tot || (long)s.f_bfree != free || (long)s.f_bavail != avail) {
+		tst_res(TFAIL,
+			"Bad quota counters: total=%li (expected %li), "
+			"free=%li (expected %li), avail=%li (expected %li)",
+			(long)s.f_blocks, tot, (long)s.f_bfree, free,
+			(long)s.f_bavail, avail);
+	}
+}
+
+static void do_map(unsigned long size, int mmap_flags, int action_flags)
+{
+	int fd;
+	char *a = MAP_FAILED, *b, *c = MAP_FAILED;
+	char path[PATH_MAX + 32];
+
+	snprintf(path, sizeof(path), "%s/test_file_%d", quota_mnt, getpid());
+	fd = SAFE_OPEN(path, O_CREAT | O_RDWR, 0600);
+	SAFE_UNLINK(path);
+
+	a = mmap(NULL, size, PROT_READ | PROT_WRITE, mmap_flags, fd, 0);
+	if (a == MAP_FAILED) {
+		if (errno == ENOMEM || errno == ENOSPC) {
+			tst_res(TINFO | TERRNO, "mmap failed as expected due to quota");
+			goto cleanup_fd;
+		}
+		tst_brk(TBROK | TERRNO, "mmap failed unexpectedly");
+	}
+
+	if (action_flags & ACTION_TOUCH) {
+		for (b = a; b < a + size; b += hpage_size)
+			*b = 1;
+	}
+
+	if (action_flags & ACTION_COW) {
+		c = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
+		if (c == MAP_FAILED) {
+			if (errno == ENOMEM || errno == ENOSPC) {
+				tst_res(TINFO | TERRNO, "COW mapping failed as expected due to quota");
+				goto cleanup_a;
+			}
+			tst_brk(TBROK | TERRNO, "COW mapping failed unexpectedly");
+		}
+
+		if (*c != 1) {
+			tst_res(TINFO, "Data mismatch when setting up COW");
+			goto cleanup_c;
+		}
+		*c = 0;
+		SAFE_MUNMAP(c, size);
+	}
+
+	SAFE_MUNMAP(a, size);
+	SAFE_CLOSE(fd);
+	return;
+
+cleanup_c:
+	SAFE_MUNMAP(c, size);
+cleanup_a:
+	SAFE_MUNMAP(a, size);
+cleanup_fd:
+	SAFE_CLOSE(fd);
+	exit(1);
+}
+
+static void run_quota_test(int expected_result,
+			   unsigned long size, int mmap_flags,
+			   int action_flags)
+{
+	pid_t pid;
+	int status;
+	int actual_result;
+
+	pid = SAFE_FORK();
+	if (pid == 0) {
+		do_map(size, mmap_flags, action_flags);
+		exit(0);
+	}
+
+	SAFE_WAITPID(pid, &status, 0);
+
+	if (WIFEXITED(status)) {
+		if (WEXITSTATUS(status) == 0)
+			actual_result = EXPECT_SUCCESS;
+		else
+			actual_result = EXPECT_FAILURE;
+	} else {
+		actual_result = EXPECT_SIGNAL;
+	}
+
+	if (actual_result != expected_result) {
+		static const char * const result_names[] = {"success", "signal", "failure"};
+
+		tst_res(TFAIL,
+			"Unexpected result: expected %s, got %s",
+			result_names[expected_result],
+			result_names[actual_result]);
+	} else {
+		tst_res(TPASS, "Quota test passed as expected");
+	}
+}
+
+static int kernel_has_private_reservations(void)
+{
+	int fd;
+	long t, f, r, s;
+	long nt, nf, nr, ns;
+	void *p;
+	char path[PATH_MAX];
+
+	t = SAFE_READ_MEMINFO(MEMINFO_HPAGE_TOTAL);
+	f = SAFE_READ_MEMINFO(MEMINFO_HPAGE_FREE);
+	r = SAFE_READ_MEMINFO(MEMINFO_HPAGE_RSVD);
+	s = SAFE_READ_MEMINFO(MEMINFO_HPAGE_SURP);
+
+	snprintf(path, sizeof(path), "%s/test_priv_resv", MNTPOINT);
+	fd = SAFE_OPEN(path, O_CREAT | O_RDWR, 0600);
+	SAFE_UNLINK(path);
+
+	p = SAFE_MMAP(NULL, hpage_size, PROT_READ | PROT_WRITE,
+		      MAP_PRIVATE, fd, 0);
+
+	nt = SAFE_READ_MEMINFO(MEMINFO_HPAGE_TOTAL);
+	nf = SAFE_READ_MEMINFO(MEMINFO_HPAGE_FREE);
+	nr = SAFE_READ_MEMINFO(MEMINFO_HPAGE_RSVD);
+	ns = SAFE_READ_MEMINFO(MEMINFO_HPAGE_SURP);
+
+	SAFE_MUNMAP(p, hpage_size);
+	SAFE_CLOSE(fd);
+
+	/* Check if reservation was created for private mapping */
+	if ((nt == t + 1) && (nf == f + 1) && (ns == s + 1) && (nr == r + 1))
+		return 1;
+	else if ((nt == t) && (nf == f) && (ns == s)) {
+		if (nr == r + 1)
+			return 1;
+		else if (nr == r)
+			return 0;
+	}
+
+	tst_brk(TCONF, "Unexpected counter state - "
+		"T:%li F:%li R:%li S:%li -> T:%li F:%li R:%li S:%li",
+		t, f, r, s, nt, nf, nr, ns);
+	return -1;
+}
+
+static void run_test(void)
+{
+	int bad_priv_resv = private_resv ? EXPECT_FAILURE : EXPECT_SIGNAL;
+
+	tst_res(TINFO, "Testing unused quota cleanup for untouched mappings");
+	run_quota_test(EXPECT_SUCCESS, hpage_size, MAP_PRIVATE, 0);
+	verify_quota_stat(1, 1, 1);
+	run_quota_test(EXPECT_SUCCESS, hpage_size, MAP_SHARED, 0);
+	verify_quota_stat(1, 1, 1);
+
+	tst_res(TINFO, "Testing page instantiation within quota limits");
+	run_quota_test(EXPECT_SUCCESS, hpage_size, MAP_PRIVATE, ACTION_TOUCH);
+	run_quota_test(EXPECT_SUCCESS, hpage_size, MAP_SHARED, ACTION_TOUCH);
+
+	tst_res(TINFO, "Testing page instantiation over quota");
+	run_quota_test(EXPECT_FAILURE, 2 * hpage_size, MAP_SHARED, ACTION_TOUCH);
+
+	tst_res(TINFO, "Testing private mapping quota check");
+	run_quota_test(bad_priv_resv, 2 * hpage_size, MAP_PRIVATE, ACTION_TOUCH);
+
+	tst_res(TINFO, "Testing COW over quota");
+	run_quota_test(bad_priv_resv, hpage_size, MAP_SHARED,
+		       ACTION_TOUCH | ACTION_COW);
+	run_quota_test(bad_priv_resv, hpage_size, MAP_PRIVATE,
+		       ACTION_TOUCH | ACTION_COW);
+
+	tst_res(TINFO, "Testing operations within quota after failures");
+	run_quota_test(EXPECT_SUCCESS, hpage_size, MAP_SHARED, ACTION_TOUCH);
+	run_quota_test(EXPECT_SUCCESS, hpage_size, MAP_PRIVATE, ACTION_TOUCH);
+}
+
+static void setup(void)
+{
+	char mount_opts[BUFSIZ];
+
+	hpage_size = tst_get_hugepage_size();
+
+	/* Create a quota-limited hugetlbfs mount */
+	snprintf(quota_mnt, sizeof(quota_mnt), "%s/quota_test", MNTPOINT);
+	SAFE_MKDIR(quota_mnt, 0755);
+
+	snprintf(mount_opts, sizeof(mount_opts), "size=%luK",
+		 hpage_size / 1024);
+
+	if (mount("none", quota_mnt, "hugetlbfs", 0, mount_opts) == -1) {
+		if (errno == ENODEV)
+			tst_brk(TCONF, "hugetlbfs not supported");
+		tst_brk(TBROK | TERRNO, "mount() failed");
+	}
+	quota_mounted = 1;
+
+	tst_res(TINFO, "Mounted hugetlbfs with quota at %s (size=%luK)",
+		quota_mnt, hpage_size / 1024);
+
+	private_resv = kernel_has_private_reservations();
+	tst_res(TINFO, "Kernel %s private reservations",
+		private_resv ? "has" : "does not have");
+}
+
+static void cleanup(void)
+{
+	if (quota_mounted) {
+		SAFE_UMOUNT(quota_mnt);
+		SAFE_RMDIR(quota_mnt);
+	}
+}
+
+static struct tst_test test = {
+	.needs_root = 1,
+	.mntpoint = MNTPOINT,
+	.needs_hugetlbfs = 1,
+	.forks_child = 1,
+	.setup = setup,
+	.cleanup = cleanup,
+	.test_all = run_test,
+	.hugepages = {2, TST_NEEDS},
+};
-- 
2.55.0


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Re: [LTP] hugetlb/hugemmap: add hugemmap33 to test hugetlbfs quota accounting

[linuxtestproject.agent]

Hi Pavithra,

On Fri, 17 Jul 2026, Pavithra wrote:
> hugetlb/hugemmap: add hugemmap33 to test hugetlbfs quota accounting

> +// SPDX-License-Identifier: LGPL-2.1-or-later

All LTP tests use GPL-2.0-or-later. LGPL-2.1-or-later is wrong here.
Every other test in this directory (hugemmap32.c, hugemmap34.c, ...) uses
GPL-2.0-or-later, as does the required test structure template.

> +	if (mount("none", quota_mnt, "hugetlbfs", 0, mount_opts) == -1) {
> +		if (errno == ENODEV)
> +			tst_brk(TCONF, "hugetlbfs not supported");
> +		tst_brk(TBROK | TERRNO, "mount() failed");
> +	}
> +	quota_mounted = 1;

The ENODEV branch is unreachable: the test already sets .needs_hugetlbfs = 1,
so the framework validates and mounts hugetlbfs at MNTPOINT before setup()
runs. Since MNTPOINT is successfully mounted, ENODEV cannot occur on the
quota mount. Use SAFE_MOUNT() instead:

    SAFE_MOUNT("none", quota_mnt, "hugetlbfs", 0, mount_opts);

> +static struct tst_test test = {
> +	.needs_root = 1,
> +	.mntpoint = MNTPOINT,
> +	.needs_hugetlbfs = 1,
> +	.forks_child = 1,
> +	.setup = setup,
> +	.cleanup = cleanup,
> +	.test_all = run_test,
> +	.hugepages = {2, TST_NEEDS},
> +};

Both the commit message and the doc comment describe this test as checking
for regressions in hugetlbfs quota accounting. Regression tests must include
a .tags entry in struct tst_test.

Verdict - Needs revision

---
Note:

The agent can sometimes produce false positives although often its
findings are genuine. If you find issues with the review, please
comment this email or ignore the suggestions.

Regards,
LTP AI Reviewer

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