Re: [PATCH] fat: Add KUnit tests for checksums and timestamps

From: OGAWA Hirofumi
Date: Sat Oct 17 2020 - 04:27:44 EST

David Gow <davidgow@xxxxxxxxxx> writes:

> Add some basic sanity-check tests for the fat_checksum() function and
> the fat_time_unix2fat() and fat_time_fat2unix() functions. These unit
> tests verify these functions return correct output for a number of test
> inputs.
>
> These tests were inspored by -- and serve a similar purpose to -- the
> timestamp parsing KUnit tests in ext4[1].
>
> [1]:
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/fs/ext4/inode-test.c
>
> Signed-off-by: David Gow <davidgow@xxxxxxxxxx>

Looks good, thanks.

Acked-by: OGAWA Hirofumi <hirofumi@xxxxxxxxxxxxxxxxxx>

> ---
> fs/fat/Kconfig | 13 +++
> fs/fat/Makefile | 2 +
> fs/fat/fat_test.c | 197 ++++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 212 insertions(+)
> create mode 100644 fs/fat/fat_test.c
>
> diff --git a/fs/fat/Kconfig b/fs/fat/Kconfig
> index 66532a71e8fd..fdef03b79c69 100644
> --- a/fs/fat/Kconfig
> +++ b/fs/fat/Kconfig
> @@ -115,3 +115,16 @@ config FAT_DEFAULT_UTF8
> Say Y if you use UTF-8 encoding for file names, N otherwise.
>
> See <file:Documentation/filesystems/vfat.rst> for more information.
> +
> +config FAT_KUNIT_TEST
> + tristate "Unit Tests for FAT filesystems" if !KUNIT_ALL_TESTS
> + select FAT_FS
> + depends on KUNIT
> + default KUNIT_ALL_TESTS
> + help
> + This builds the FAT KUnit tests
> +
> + For more information on KUnit and unit tests in general, please refer
> + to the KUnit documentation in Documentation/dev-tools/kunit
> +
> + If unsure, say N
> diff --git a/fs/fat/Makefile b/fs/fat/Makefile
> index 70645ce2f7fc..2b034112690d 100644
> --- a/fs/fat/Makefile
> +++ b/fs/fat/Makefile
> @@ -10,3 +10,5 @@ obj-$(CONFIG_MSDOS_FS) += msdos.o
> fat-y := cache.o dir.o fatent.o file.o inode.o misc.o nfs.o
> vfat-y := namei_vfat.o
> msdos-y := namei_msdos.o
> +
> +obj-$(CONFIG_FAT_KUNIT_TEST) += fat_test.o
> diff --git a/fs/fat/fat_test.c b/fs/fat/fat_test.c
> new file mode 100644
> index 000000000000..c1b4348b9b3b
> --- /dev/null
> +++ b/fs/fat/fat_test.c
> @@ -0,0 +1,197 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * KUnit tests for FAT filesystems.
> + *
> + * Copyright (C) 2020 Google LLC.
> + * Author: David Gow <davidgow@xxxxxxxxxx>
> + */
> +
> +#include <kunit/test.h>
> +
> +#include "fat.h"
> +
> +static void fat_checksum_test(struct kunit *test)
> +{
> + /* With no extension. */
> + KUNIT_EXPECT_EQ(test, fat_checksum("VMLINUX "), 44);
> + /* With 3-letter extension. */
> + KUNIT_EXPECT_EQ(test, fat_checksum("README TXT"), 115);
> + /* With short (1-letter) extension. */
> + KUNIT_EXPECT_EQ(test, fat_checksum("ABCDEFGHA "), 98);
> +}
> +
> +
> +struct fat_timestamp_testcase {
> + const char *name;
> + struct timespec64 ts;
> + __le16 time;
> + __le16 date;
> + u8 cs;
> + int time_offset;
> +};
> +
> +const static struct fat_timestamp_testcase time_test_cases[] = {
> + {
> + .name = "Earliest possible UTC (1980-01-01 00:00:00)",
> + .ts = {.tv_sec = 315532800LL, .tv_nsec = 0L},
> + .time = 0,
> + .date = 33,
> + .cs = 0,
> + .time_offset = 0,
> + },
> + {
> + .name = "Latest possible UTC (2107-12-31 23:59:58)",
> + .ts = {.tv_sec = 4354819198LL, .tv_nsec = 0L},
> + .time = 49021,
> + .date = 65439,
> + .cs = 0,
> + .time_offset = 0,
> + },
> + {
> + .name = "Earliest possible (UTC-11) (== 1979-12-31 13:00:00 UTC)",
> + .ts = {.tv_sec = 315493200LL, .tv_nsec = 0L},
> + .time = 0,
> + .date = 33,
> + .cs = 0,
> + .time_offset = 11 * 60,
> + },
> + {
> + .name = "Latest possible (UTC+11) (== 2108-01-01 10:59:58 UTC)",
> + .ts = {.tv_sec = 4354858798LL, .tv_nsec = 0L},
> + .time = 49021,
> + .date = 65439,
> + .cs = 0,
> + .time_offset = -11 * 60,
> + },
> + {
> + .name = "Leap Day / Year (1996-02-29 00:00:00)",
> + .ts = {.tv_sec = 825552000LL, .tv_nsec = 0L},
> + .time = 0,
> + .date = 8285,
> + .cs = 0,
> + .time_offset = 0,
> + },
> + {
> + .name = "Year 2000 is leap year (2000-02-29 00:00:00)",
> + .ts = {.tv_sec = 951782400LL, .tv_nsec = 0L},
> + .time = 0,
> + .date = 10333,
> + .cs = 0,
> + .time_offset = 0,
> + },
> + {
> + .name = "Year 2100 not leap year (2100-03-01 00:00:00)",
> + .ts = {.tv_sec = 4107542400LL, .tv_nsec = 0L},
> + .time = 0,
> + .date = 61537,
> + .cs = 0,
> + .time_offset = 0,
> + },
> + {
> + .name = "Leap year + timezone UTC+1 (== 2004-02-29 00:30:00 UTC)",
> + .ts = {.tv_sec = 1078014600LL, .tv_nsec = 0L},
> + .time = 48064,
> + .date = 12380,
> + .cs = 0,
> + .time_offset = -60,
> + },
> + {
> + .name = "Leap year + timezone UTC-1 (== 2004-02-29 23:30:00 UTC)",
> + .ts = {.tv_sec = 1078097400LL, .tv_nsec = 0L},
> + .time = 960,
> + .date = 12385,
> + .cs = 0,
> + .time_offset = 60,
> + },
> + {
> + .name = "VFAT odd-second resolution (1999-12-31 23:59:59)",
> + .ts = {.tv_sec = 946684799LL, .tv_nsec = 0L},
> + .time = 49021,
> + .date = 10143,
> + .cs = 100,
> + .time_offset = 0,
> + },
> + {
> + .name = "VFAT 10ms resolution (1980-01-01 00:00:00:0010)",
> + .ts = {.tv_sec = 315532800LL, .tv_nsec = 10000000L},
> + .time = 0,
> + .date = 33,
> + .cs = 1,
> + .time_offset = 0,
> + },
> +};
> +
> +static void fat_time_fat2unix_test(struct kunit *test)
> +{
> + struct msdos_sb_info fake_sb;
> + int i;
> + struct timespec64 ts;
> +
> + for (i = 0; i < ARRAY_SIZE(time_test_cases); ++i) {
> + fake_sb.options.tz_set = 1;
> + fake_sb.options.time_offset = time_test_cases[i].time_offset;
> +
> + fat_time_fat2unix(&fake_sb, &ts,
> + time_test_cases[i].time,
> + time_test_cases[i].date,
> + time_test_cases[i].cs);
> + KUNIT_EXPECT_EQ_MSG(test,
> + time_test_cases[i].ts.tv_sec,
> + ts.tv_sec,
> + "Timestamp mismatch (seconds) in case \"%s\"\n",
> + time_test_cases[i].name);
> + KUNIT_EXPECT_EQ_MSG(test,
> + time_test_cases[i].ts.tv_nsec,
> + ts.tv_nsec,
> + "Timestamp mismatch (nanoseconds) in case \"%s\"\n",
> + time_test_cases[i].name);
> + }
> +}
> +
> +static void fat_time_unix2fat_test(struct kunit *test)
> +{
> + struct msdos_sb_info fake_sb;
> + int i;
> + __le16 date, time;
> + u8 cs;
> +
> + for (i = 0; i < ARRAY_SIZE(time_test_cases); ++i) {
> + fake_sb.options.tz_set = 1;
> + fake_sb.options.time_offset = time_test_cases[i].time_offset;
> +
> + fat_time_unix2fat(&fake_sb, &time_test_cases[i].ts,
> + &time, &date, &cs);
> + KUNIT_EXPECT_EQ_MSG(test,
> + time_test_cases[i].time,
> + time,
> + "Time mismatch in case \"%s\"\n",
> + time_test_cases[i].name);
> + KUNIT_EXPECT_EQ_MSG(test,
> + time_test_cases[i].date,
> + date,
> + "Date mismatch in case \"%s\"\n",
> + time_test_cases[i].name);
> + KUNIT_EXPECT_EQ_MSG(test,
> + time_test_cases[i].cs,
> + cs,
> + "Centisecond mismatch in case \"%s\"\n",
> + time_test_cases[i].name);
> + }
> +}
> +
> +static struct kunit_case fat_test_cases[] = {
> + KUNIT_CASE(fat_checksum_test),
> + KUNIT_CASE(fat_time_fat2unix_test),
> + KUNIT_CASE(fat_time_unix2fat_test),
> + {},
> +};
> +
> +static struct kunit_suite fat_test_suite = {
> + .name = "fat_test",
> + .test_cases = fat_test_cases,
> +};
> +
> +kunit_test_suites(&fat_test_suite);
> +
> +MODULE_LICENSE("GPL v2");
> +

--
OGAWA Hirofumi <hirofumi@xxxxxxxxxxxxxxxxxx>