+ selftests-mm-add-memory-failure-clean-pagecache-test.patch added to mm-new branch

[Andrew Morton <akpm@linux-foundation.org>]

The patch titled
     Subject: selftests/mm: add memory failure clean pagecache test
has been added to the -mm mm-new branch.  Its filename is
     selftests-mm-add-memory-failure-clean-pagecache-test.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/selftests-mm-add-memory-failure-clean-pagecache-test.patch

This patch will later appear in the mm-new branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Note, mm-new is a provisional staging ground for work-in-progress
patches, and acceptance into mm-new is a notification for others take
notice and to finish up reviews.  Please do not hesitate to respond to
review feedback and post updated versions to replace or incrementally
fixup patches in mm-new.

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------------------------------------------------------
From: Miaohe Lin <linmiaohe@huawei.com>
Subject: selftests/mm: add memory failure clean pagecache test
Date: Tue, 20 Jan 2026 20:32:38 +0800

This patch adds a new testcase to validate memory failure handling for
clean pagecache.  This test performs similar operations as anonymous pages
except allocating memory using mmap() with a file fd.

This test helps ensure that memory failure handling for clean pagecache
works correctly, including unchanged page content, page isolation, and
recovery paths.

Link: https://lkml.kernel.org/r/20260120123239.909882-3-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 tools/testing/selftests/mm/memory-failure.c |   66 ++++++++++++++++++
 1 file changed, 66 insertions(+)

--- a/tools/testing/selftests/mm/memory-failure.c~selftests-mm-add-memory-failure-clean-pagecache-test
+++ a/tools/testing/selftests/mm/memory-failure.c
@@ -10,10 +10,14 @@
 #include <sys/mman.h>
 #include <linux/mman.h>
 #include <linux/string.h>
+#include <unistd.h>
 #include <signal.h>
 #include <setjmp.h>
 #include <unistd.h>
 #include <fcntl.h>
+#include <sys/vfs.h>
+#include <linux/magic.h>
+#include <errno.h>
 
 #include "vm_util.h"
 
@@ -24,7 +28,9 @@ enum inject_type {
 
 enum result_type {
 	MADV_HARD_ANON,
+	MADV_HARD_CLEAN_PAGECACHE,
 	MADV_SOFT_ANON,
+	MADV_SOFT_CLEAN_PAGECACHE,
 };
 
 static jmp_buf signal_jmp_buf;
@@ -154,6 +160,8 @@ static void check(struct __test_metadata
 
 	switch (type) {
 	case MADV_SOFT_ANON:
+	case MADV_HARD_CLEAN_PAGECACHE:
+	case MADV_SOFT_CLEAN_PAGECACHE:
 		/* It is not expected to receive a SIGBUS signal. */
 		ASSERT_EQ(setjmp, 0);
 
@@ -236,4 +244,62 @@ TEST_F(memory_failure, anon)
 	ASSERT_EQ(munmap(addr, self->page_size), 0);
 }
 
+/* Borrowed from mm/gup_longterm.c. */
+static __fsword_t get_fs_type(int fd)
+{
+	struct statfs fs;
+	int ret;
+
+	do {
+		ret = fstatfs(fd, &fs);
+	} while (ret && errno == EINTR);
+
+	return ret ? 0 : fs.f_type;
+}
+
+TEST_F(memory_failure, clean_pagecache)
+{
+	const char *fname = "./clean-page-cache-test-file";
+	int fd;
+	char *addr;
+	int ret;
+	__fsword_t fs_type;
+
+	fd = open(fname, O_RDWR | O_CREAT, 0664);
+	if (fd < 0)
+		SKIP(return, "failed to open test file.\n");
+	unlink(fname);
+	ftruncate(fd, self->page_size);
+	fs_type = get_fs_type(fd);
+	if (!fs_type || fs_type == TMPFS_MAGIC)
+		SKIP(return, "unsupported filesystem :%lx\n", fs_type);
+
+	addr = mmap(0, self->page_size, PROT_READ | PROT_WRITE,
+		    MAP_SHARED, fd, 0);
+	if (addr == MAP_FAILED)
+		SKIP(return, "mmap failed, not enough memory.\n");
+	memset(addr, 0xce, self->page_size);
+	fsync(fd);
+
+	prepare(_metadata, self, addr);
+
+	ret = sigsetjmp(signal_jmp_buf, 1);
+	if (!self->triggered) {
+		self->triggered = true;
+		ASSERT_EQ(variant->inject(self, addr), 0);
+		FORCE_READ(*addr);
+	}
+
+	if (variant->type == MADV_HARD)
+		check(_metadata, self, addr, MADV_HARD_CLEAN_PAGECACHE, ret);
+	else
+		check(_metadata, self, addr, MADV_SOFT_CLEAN_PAGECACHE, ret);
+
+	cleanup(_metadata, self, addr);
+
+	ASSERT_EQ(munmap(addr, self->page_size), 0);
+
+	ASSERT_EQ(close(fd), 0);
+}
+
 TEST_HARNESS_MAIN
_

Patches currently in -mm which might be from linmiaohe@huawei.com are

selftests-mm-add-memory-failure-anonymous-page-test.patch
selftests-mm-add-memory-failure-clean-pagecache-test.patch
selftests-mm-add-memory-failure-dirty-pagecache-test.patch