syscalls/statx10: Add basic test for STATX_DIOALIGN on regular file

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 creates own
filesystem by enabling mount_device in tst_test struct. If we set block
device to LTP_DEV environment, we use this block device to mount by using
default mount option. Otherwise, use loop device to simuate it. So it can
avoid these above situations and don't fall back to buffered I/O.

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

Reviewed-by: Xiao Yang <[email protected]>
Signed-off-by: Yang Xu <[email protected]>

Author: xuyang0410

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>
 ])

runtest/syscalls

@@ -1765,6 +1765,7 @@ statx06 statx06
 statx07 statx07
 statx08 statx08
 statx09 statx09
+statx10 statx10
 
 membarrier01 membarrier01
 

testcases/kernel/syscalls/statx/.gitignore

@@ -7,3 +7,4 @@
 /statx07
 /statx08
 /statx09
+/statx10

testcases/kernel/syscalls/statx/statx10.c

@@ -0,0 +1,93 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2023 FUJITSU LIMITED. All rights reserved.
+ * Author: Yang Xu <[email protected]>
+ */
+
+/*\
+ * [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
+ *
+ * Check these two values are nonzero under dio situation when STATX_DIOALIGN
+ * in the request mask.
+ *
+ * On ext4, files that use certain filesystem features (data journaling,
+ * encryption, and verity) fall back to buffered I/O. But ltp creates own
+ * filesystem by enabling mount_device in tst_test struct. If we set block
+ * device to LTP_DEV environment, we use this block device to mount by using
+ * default mount option. Otherwise, use loop device to simuate it. So it can
+ * avoid these above situations and don't fall back to buffered I/O.
+ *
+ * Minimum Linux version required is v6.1.
+ */
+
+#define _GNU_SOURCE
+#include <sys/types.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include "tst_test.h"
+#include "lapi/stat.h"
+#include "lapi/fcntl.h"
+
+#define MNTPOINT "mnt_point"
+#define TESTFILE MNTPOINT"/testfile"
+
+static void verify_statx(void)
+{
+	struct statx buf;
+
+	TST_EXP_PASS_SILENT(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, "Filesystem does not support STATX_DIOALIGN");
+		return;
+	}
+
+#ifdef HAVE_STRUCT_STATX_STX_DIO_MEM_ALIGN
+	if (buf.stx_dio_mem_align != 0)
+		tst_res(TPASS, "stx_dio_mem_align:%u", buf.stx_dio_mem_align);
+	else
+		tst_res(TFAIL, "stx_dio_mem_align was 0, but DIO should be supported");
+
+	if (buf.stx_dio_offset_align != 0)
+		tst_res(TPASS, "stx_dio_offset_align:%u", buf.stx_dio_offset_align);
+	else
+		tst_res(TFAIL, "stx_dio_offset_align was 0, but DIO should be supported");
+#else
+	tst_res(TCONF, "glibc statx struct miss stx_dio_mem_align field");
+#endif
+}
+
+static void setup(void)
+{
+	int fd = -1;
+
+	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) {
+		if (errno == EINVAL)
+			tst_brk(TCONF,
+				"The regular file is not on a filesystem that support DIO");
+		else
+			tst_brk(TBROK | TERRNO,
+				"The regular file is open with O_RDWR | O_DIRECT failed");
+	}
+	SAFE_CLOSE(fd);
+}
+
+static struct tst_test test = {
+	.test_all = verify_statx,
+	.setup = setup,
+	.needs_root = 1,
+	.mntpoint = MNTPOINT,
+	.mount_device = 1,
+	.all_filesystems = 1,
+};