[LTP] [PATCH v3 2/4] syscalls/statx10: Add basic test for STATX_DIOALIGN on regular file

[Yang Xu]

If the caller didn't include STATX_DIOALIGN in the request mask,
direct I/O alignment information isn't returned since statx() isn't
required to return unrequested information.

STATX_DIOALIGN is used to get stx_dio_mem_align and stx_dio_offset_align
for files on fs that support direct io. We just check whether these
value are nonzero on ext4 and xfs.

On ext4, files that use certain filesystem features (data journalling,
encryption, and verity) fall back to buffered I/O. But ltp doesn't use
these features by default, So I think dio should not fall back to
buffered I/O.

For struct statx member check, we only check stx_dio_mem_align because
these two member is introduced toger in separate commit in kernel, so it is
safe.

Signed-off-by: Yang Xu <xuyang2018.jy@fujitsu.com>
---
v2->v3:
1. fix testfile path problme
2. also test stx_dio_mem_align and stx_dio_offset_align is not filled
when not request STATX_DIOALIGN
 configure.ac                               |  2 +-
 runtest/syscalls                           |  1 +
 testcases/kernel/syscalls/statx/.gitignore |  1 +
 testcases/kernel/syscalls/statx/statx10.c  | 98 ++++++++++++++++++++++
 4 files changed, 101 insertions(+), 1 deletion(-)
 create mode 100644 testcases/kernel/syscalls/statx/statx10.c

diff --git a/configure.ac b/configure.ac
index 4c8763376..548288310 100644
--- a/configure.ac
+++ b/configure.ac
@@ -158,7 +158,7 @@ AC_CHECK_FUNCS(mkdtemp,[],AC_MSG_ERROR(mkdtemp() not found!))
 AC_CHECK_MEMBERS([struct fanotify_event_info_fid.fsid.__val],,,[#include <sys/fanotify.h>])
 AC_CHECK_MEMBERS([struct perf_event_mmap_page.aux_head],,,[#include <linux/perf_event.h>])
 AC_CHECK_MEMBERS([struct sigaction.sa_sigaction],[],[],[#include <signal.h>])
-AC_CHECK_MEMBERS([struct statx.stx_mnt_id],,,[
+AC_CHECK_MEMBERS([struct statx.stx_mnt_id, struct statx.stx_dio_mem_align],,,[
 #define _GNU_SOURCE
 #include <sys/stat.h>
 ])
diff --git a/runtest/syscalls b/runtest/syscalls
index 8b002e989..92123772c 100644
--- a/runtest/syscalls
+++ b/runtest/syscalls
@@ -1769,6 +1769,7 @@ statx06 statx06
 statx07 statx07
 statx08 statx08
 statx09 statx09
+statx10 statx10
 
 membarrier01 membarrier01
 
diff --git a/testcases/kernel/syscalls/statx/.gitignore b/testcases/kernel/syscalls/statx/.gitignore
index 1cea43c0d..67341ff2d 100644
--- a/testcases/kernel/syscalls/statx/.gitignore
+++ b/testcases/kernel/syscalls/statx/.gitignore
@@ -7,3 +7,4 @@
 /statx07
 /statx08
 /statx09
+/statx10
diff --git a/testcases/kernel/syscalls/statx/statx10.c b/testcases/kernel/syscalls/statx/statx10.c
new file mode 100644
index 000000000..7e5d287d9
--- /dev/null
+++ b/testcases/kernel/syscalls/statx/statx10.c
@@ -0,0 +1,98 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2023 FUJITSU LIMITED. All rights reserved.
+ * Author: Yang Xu <xuyang2018.jy@fujitsu.com>
+ */
+
+/*\
+ * [Description]
+ *
+ * It is a basic test for STATX_DIOALIGN mask on ext4 and xfs filesystem.
+ *
+ * - STATX_DIOALIGN   Want stx_dio_mem_align and stx_dio_offset_align value
+ *
+ * These two values are only filled when STATX_DIOALIGN in the request mask.
+ * Also check these two values are nonzero under dio situation when
+ * STATX_DIOALIGN in the request mask
+ *
+ * Minimum Linux version required is v6.1.
+ */
+
+#define _GNU_SOURCE
+#include <sys/types.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include "tst_test.h"
+#include "lapi/stat.h"
+
+#ifdef HAVE_STRUCT_STATX_STX_DIO_MEM_ALIGN
+#define MNTPOINT "mnt_point"
+#define TESTFILE MNTPOINT"/testfile"
+
+static int fd = -1;
+
+static void verify_statx(void)
+{
+	struct statx buf;
+
+	memset(&buf, 0, sizeof(buf));
+	TST_EXP_PASS(statx(AT_FDCWD, TESTFILE, 0, STATX_DIOALIGN, &buf),
+		"statx(AT_FDCWD, %s, 0, STATX_DIOALIGN, &buf)", TESTFILE);
+
+	if (!(buf.stx_mask & STATX_DIOALIGN)) {
+		tst_res(TCONF, "STATX_DIOALIGN is not supported until linux 6.1");
+		return;
+	}
+
+	if (buf.stx_dio_mem_align != 0)
+		tst_res(TPASS, "stx_dio_mem_align:%u", buf.stx_dio_mem_align);
+	else
+		tst_res(TFAIL, "don't get stx_dio_mem_align on supported dio fs");
+
+	if (buf.stx_dio_offset_align != 0)
+		tst_res(TPASS, "stx_dio_offset_align:%u", buf.stx_dio_offset_align);
+	else
+		tst_res(TFAIL, "don't get stx_dio_offset_align on supported dio fs");
+
+	TST_EXP_PASS(statx(AT_FDCWD, TESTFILE, 0, 0, &buf),
+		"statx(AT_FDCWD, %s, 0, 0, &buf)", TESTFILE);
+
+	if ((buf.stx_mask & STATX_DIOALIGN)) {
+		tst_res(TFAIL, "STATX_DIOALIGN mask return even not request");
+		return;
+	}
+	TST_EXP_EQ_LU(buf.stx_dio_mem_align, 0);
+	TST_EXP_EQ_LU(buf.stx_dio_offset_align, 0);
+}
+
+static void setup(void)
+{
+	if (strcmp(tst_device->fs_type, "xfs") && strcmp(tst_device->fs_type, "ext4"))
+		tst_brk(TCONF, "This test only supports ext4 and xfs");
+
+	SAFE_FILE_PRINTF(TESTFILE, "AAAA");
+	fd = open(TESTFILE, O_RDWR | O_DIRECT);
+	if (fd == -1 && errno == EINVAL)
+		tst_brk(TCONF, "The regular file is not on a filesystem that support DIO");
+}
+
+static void cleanup(void)
+{
+	if (fd > -1)
+		SAFE_CLOSE(fd);
+}
+
+static struct tst_test test = {
+	.test_all = verify_statx,
+	.setup = setup,
+	.cleanup = cleanup,
+	.needs_root = 1,
+	.mntpoint = MNTPOINT,
+	.mount_device = 1,
+	.all_filesystems = 1,
+};
+#else
+TST_TEST_TCONF("test requires struct statx to have the stx_dio_mem_align fields");
+#endif
-- 
2.39.1