[v2] Add test for misaligned fallocate()
diff mbox series

Message ID 20200116123100.13345-1-mdoucha@suse.cz
State New
Headers show
Series
  • [v2] Add test for misaligned fallocate()
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Commit Message

Martin Doucha Jan. 16, 2020, 12:31 p.m. UTC
Make sure that space allocation and deallocation works (or fails) correctly
even when the requested file range does not align with filesystem blocks.

Test on:
- empty file system
- full file system
- also test with and without copy-on-write when supported

Signed-off-by: Martin Doucha <mdoucha@suse.cz>
---

Note for reviewers: Feel free to ignore this patch until next week.

This patch is a follow-up to the fallocate05 fix. The original fallocate05
test accidentally tested some misaligned allocation and deallocation
on platforms with block size bigger than 8k but it didn't validate
the results correctly. Test calling fallocate() on misaligned file range
and this time validate the results properly, taking into account advanced
FS features like copy-on-write.

Changes since v1:
- Fix compilation with --std=c89
- Misalign by at most 512 bytes, otherwise the test may miss an XFS bug on PPC

 runtest/syscalls                              |   1 +
 .../kernel/syscalls/fallocate/fallocate06.c   | 253 ++++++++++++++++++
 2 files changed, 254 insertions(+)
 create mode 100644 testcases/kernel/syscalls/fallocate/fallocate06.c

Comments

Cyril Hrubis Jan. 21, 2020, 3:49 p.m. UTC | #1
Hi!
> +	SAFE_CLOSE(fd);
> +	tst_system("rm -r " MNTPOINT "/*");

Just FYI, we already have something like this implemented but not
exported outside of the test library. We basically need a public
wrapper around the rmobj() function from the tst_tmpdir.c

> +}
> +
> +static void cleanup(void)
> +{
> +	free(wbuf);
> +	free(rbuf);
> +}
> +
> +static struct tst_test test = {
> +	.test = run,
> +	.tcnt = ARRAY_SIZE(testcase_list),
> +	.needs_root = 1,
> +	.mount_device = 1,
> +	.dev_min_size = 512,
> +	.mntpoint = MNTPOINT,
> +	.all_filesystems = 1,
> +	.setup = setup,
> +	.cleanup = cleanup,
> +};
> -- 
> 2.24.1
> 
> 
> -- 
> Mailing list info: https://lists.linux.it/listinfo/ltp

Patch
diff mbox series

diff --git a/runtest/syscalls b/runtest/syscalls
index fa87ef63f..ec522e8fa 100644
--- a/runtest/syscalls
+++ b/runtest/syscalls
@@ -184,6 +184,7 @@  fallocate02 fallocate02
 fallocate03 fallocate03
 fallocate04 fallocate04
 fallocate05 fallocate05
+fallocate06 fallocate06
 
 fsetxattr01 fsetxattr01
 fsetxattr02 fsetxattr02
diff --git a/testcases/kernel/syscalls/fallocate/fallocate06.c b/testcases/kernel/syscalls/fallocate/fallocate06.c
new file mode 100644
index 000000000..6ec9df030
--- /dev/null
+++ b/testcases/kernel/syscalls/fallocate/fallocate06.c
@@ -0,0 +1,253 @@ 
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2019 SUSE LLC <mdoucha@suse.cz>
+ */
+
+/*
+ * Tests misaligned fallocate()
+ * Test scenario:
+ * 1. write() several blocks worth of data
+ * 2. fallocate() some more space (not aligned to FS blocks)
+ * 3. try to write() into the allocated space
+ * 4. deallocate misaligned part of file range written in step 1
+ * 5. read() the deallocated range and check that it was zeroed
+ *
+ * Subtests:
+ * - fill file system between step 2 and 3
+ * - disable copy-on-write on test file
+ * - combinations of above subtests
+ */
+
+#define _GNU_SOURCE
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <fcntl.h>
+#include <sys/ioctl.h>
+#include <linux/fs.h>
+#include "tst_test.h"
+#include "lapi/fallocate.h"
+
+#define MNTPOINT "mntpoint"
+#define TEMPFILE MNTPOINT "/test_file"
+#define WRITE_BLOCKS 8
+#define FALLOCATE_BLOCKS 2
+#define DEALLOCATE_BLOCKS 3
+#define TESTED_FLAGS "fallocate(FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE)"
+
+const struct test_case {
+	int no_cow, fill_fs;
+} testcase_list[] = {
+	{1, 0},
+	{1, 1},
+	{0, 0},
+	{0, 1}
+};
+
+static int cow_support;
+static char *wbuf, *rbuf;
+static blksize_t blocksize;
+static long wbuf_size, rbuf_size, block_offset;
+
+static int toggle_cow(int fd, int enable)
+{
+	int ret, attr;
+
+	ret = ioctl(fd, FS_IOC_GETFLAGS, &attr);
+
+	if (ret)
+		return ret;
+
+	if (enable)
+		attr &= ~FS_NOCOW_FL;
+	else
+		attr |= FS_NOCOW_FL;
+
+	return ioctl(fd, FS_IOC_SETFLAGS, &attr);
+}
+
+static void setup(void) {
+	unsigned char ch;
+	long i;
+	int fd;
+	struct stat statbuf;
+
+	fd = SAFE_OPEN(TEMPFILE, O_WRONLY | O_CREAT | O_TRUNC);
+
+	/*
+	 * Set FS_NOCOW_FL flag on the temp file. Non-CoW filesystems will
+	 * return error.
+	 */
+	TEST(toggle_cow(fd, 0));
+	SAFE_FSTAT(fd, &statbuf);
+	blocksize = statbuf.st_blksize;
+	block_offset = MIN(blocksize / 2, 512);
+	wbuf_size = MAX(WRITE_BLOCKS, FALLOCATE_BLOCKS) * blocksize;
+	rbuf_size = (DEALLOCATE_BLOCKS + 1) * blocksize;
+	SAFE_CLOSE(fd);
+	SAFE_UNLINK(TEMPFILE);
+
+	if (blocksize < 2)
+		tst_brk(TCONF, "Block size %ld too small for test", blocksize);
+
+	if (!TST_RET)
+		cow_support = 1;
+	else switch (TST_ERR) {
+	case ENOTSUP:
+	case ENOTTY:
+	case EINVAL:
+	case ENOSYS:
+		cow_support = 0;
+		break;
+
+	default:
+		tst_brk(TBROK|TTERRNO, "Error checking copy-on-write support");
+	}
+
+	tst_res(TINFO, "Copy-on-write is%s supported",
+		cow_support ? "" : " not");
+	wbuf = SAFE_MALLOC(wbuf_size);
+	rbuf = SAFE_MALLOC(rbuf_size);
+
+	/* Fill the buffer with known values */
+	for (i = 0, ch = 1; i < wbuf_size; i++, ch++) {
+		wbuf[i] = ch;
+	}
+}
+
+static int check_result(const struct test_case *tc, const char *func, long exp)
+{
+	if (tc->fill_fs && !tc->no_cow && TST_RET < 0) {
+		if (TST_RET != -1) {
+			tst_res(TFAIL, "%s returned unexpected value %ld",
+				func, TST_RET);
+			return 0;
+		}
+
+		if (TST_ERR != ENOSPC) {
+			tst_res(TFAIL | TTERRNO, "%s should fail with ENOSPC",
+				func);
+			return 0;
+		}
+
+		tst_res(TPASS | TTERRNO, "%s on full FS with CoW", func);
+	} else if (TST_RET < 0) {
+		tst_res(TFAIL | TTERRNO, "%s failed unexpectedly", func);
+		return 0;
+	} else if (TST_RET != exp) {
+		tst_res(TFAIL,
+			"Unexpected return value from %s: %ld (expected %ld)",
+			func, TST_RET, exp);
+		return 0;
+	} else
+		tst_res(TPASS, "%s successful", func);
+
+	return 1;
+}
+
+static void run(unsigned int n)
+{
+	int fd;
+	long offset, size;
+	const struct test_case *tc = testcase_list + n;
+
+	tst_res(TINFO, "Case %u. Fill FS: %s; Use copy on write: %s", n+1,
+		tc->fill_fs ? "yes" : "no", tc->no_cow ? "no" : "yes");
+	fd = SAFE_OPEN(TEMPFILE, O_RDWR | O_CREAT | O_TRUNC);
+
+	if (cow_support)
+		toggle_cow(fd, !tc->no_cow);
+	else if (!tc->no_cow)
+		tst_brk(TCONF, "File system does not support copy-on-write");
+
+	/* Prepare test data for deallocation test */
+	size = WRITE_BLOCKS * blocksize;
+	TEST(write(fd, wbuf, size));
+
+	if (TST_RET < 0)
+		tst_res(TFAIL | TTERRNO, "write() failed unexpectedly");
+	else if (TST_RET != size)
+		tst_res(TFAIL, "Short write(): %ld bytes (expected %ld)",
+			TST_RET, size);
+	else
+		tst_res(TPASS, "write() wrote %ld bytes", TST_RET);
+
+	/* Allocation test */
+	offset = size + block_offset;
+	size = FALLOCATE_BLOCKS * blocksize;
+	TEST(fallocate(fd, 0, offset, size));
+
+	if (TST_RET) {
+		if (TST_ERR == ENOTSUP) {
+			SAFE_CLOSE(fd);
+			tst_brk(TCONF | TTERRNO, "fallocate() not supported");
+		}
+
+		tst_brk(TBROK | TTERRNO, "fallocate(fd, 0, %ld, %ld)", offset,
+			size);
+	}
+
+	if (tc->fill_fs)
+		tst_fill_fs(MNTPOINT, 1);
+
+	SAFE_LSEEK(fd, offset, SEEK_SET);
+	TEST(write(fd, wbuf, size));
+	if (check_result(tc, "write()", size))
+		tst_res(TPASS, "Misaligned allocation works as expected");
+
+	/* Deallocation test */
+	size = DEALLOCATE_BLOCKS * blocksize;
+	offset = block_offset;
+	TEST(fallocate(fd, FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE, offset,
+		size));
+
+	if (TST_RET == -1 && TST_ERR == ENOTSUP) {
+		tst_res(TCONF | TTERRNO, TESTED_FLAGS);
+	} else if (check_result(tc, TESTED_FLAGS, 0) && !TST_RET) {
+		int i, err = 0;
+
+		SAFE_LSEEK(fd, 0, SEEK_SET);
+		SAFE_READ(1, fd, rbuf, rbuf_size);
+
+		for (i = offset; i < offset + size; i++) {
+			if (rbuf[i]) {
+				err = 1;
+				break;
+			}
+		}
+
+		err = err || memcmp(rbuf, wbuf, offset);
+		offset += size;
+		size = rbuf_size - offset;
+		err = err || memcmp(rbuf + offset, wbuf + offset, size);
+
+		if (err)
+			tst_res(TFAIL, TESTED_FLAGS
+				" did not clear the correct file range.");
+		else
+			tst_res(TPASS, TESTED_FLAGS
+				" cleared the correct file range");
+	}
+
+	SAFE_CLOSE(fd);
+	tst_system("rm -r " MNTPOINT "/*");
+}
+
+static void cleanup(void)
+{
+	free(wbuf);
+	free(rbuf);
+}
+
+static struct tst_test test = {
+	.test = run,
+	.tcnt = ARRAY_SIZE(testcase_list),
+	.needs_root = 1,
+	.mount_device = 1,
+	.dev_min_size = 512,
+	.mntpoint = MNTPOINT,
+	.all_filesystems = 1,
+	.setup = setup,
+	.cleanup = cleanup,
+};