public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
To: Christian Brauner <brauner@kernel.org>
Cc: aviv.daum@gmail.com, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2] fat: add KUnit tests for timestamp conversion helpers
Date: Mon, 16 Mar 2026 12:25:57 +0900	[thread overview]
Message-ID: <87h5qgsbei.fsf@mail.parknet.co.jp> (raw)
In-Reply-To: <20260315222404.9678-1-aviv.daum@gmail.com>

aviv.daum@gmail.com writes:

> From: avivdaum <aviv.daum@gmail.com>
>
> Extend fat_test with coverage for FAT timestamp edge cases that are not
> currently exercised.
>
> Add tests for fat_time_unix2fat() clamping at the UTC boundaries and
> when time_offset pushes an otherwise valid timestamp outside the FAT
> date range. Also cover the NULL time_cs path used by existing callers,
> and verify fat_truncate_atime() truncation across timezone offsets.
>
> Signed-off-by: avivdaum <aviv.daum@gmail.com>

Looks good. Thanks.

Acked-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>

> v2:
> - Compare __le16 values directly in unix2fat tests
>
> ---
>  fs/fat/fat_test.c | 181 ++++++++++++++++++++++++++++++++++++++++++++--
>  1 file changed, 173 insertions(+), 8 deletions(-)
>
> diff --git a/fs/fat/fat_test.c b/fs/fat/fat_test.c
> index 1f0062659..5c97a7fcc 100644
> --- a/fs/fat/fat_test.c
> +++ b/fs/fat/fat_test.c
> @@ -29,6 +29,22 @@ struct fat_timestamp_testcase {
>  	int time_offset;
>  };
>  
> +struct fat_unix2fat_clamp_testcase {
> +	const char *name;
> +	struct timespec64 ts;
> +	__le16 time;
> +	__le16 date;
> +	u8 cs;
> +	int time_offset;
> +};
> +
> +struct fat_truncate_atime_testcase {
> +	const char *name;
> +	struct timespec64 ts;
> +	struct timespec64 expected;
> +	int time_offset;
> +};
> +
>  static struct fat_timestamp_testcase time_test_cases[] = {
>  	{
>  		.name = "Earliest possible UTC (1980-01-01 00:00:00)",
> @@ -120,13 +136,92 @@ static struct fat_timestamp_testcase time_test_cases[] = {
>  	},
>  };
>  
> +static struct fat_unix2fat_clamp_testcase unix2fat_clamp_test_cases[] = {
> +	{
> +		.name = "Clamp to earliest FAT date for 1979-12-31 23:59:59 UTC",
> +		.ts = {.tv_sec = 315532799LL, .tv_nsec = 0L},
> +		.time = cpu_to_le16(0),
> +		.date = cpu_to_le16(33),
> +		.cs = 0,
> +		.time_offset = 0,
> +	},
> +	{
> +		.name = "Clamp after time_offset=-60 pushes 1980-01-01 00:30 UTC below 1980",
> +		.ts = {.tv_sec = 315534600LL, .tv_nsec = 0L},
> +		.time = cpu_to_le16(0),
> +		.date = cpu_to_le16(33),
> +		.cs = 0,
> +		.time_offset = -60,
> +	},
> +	{
> +		.name = "Clamp to latest FAT date for 2108-01-01 00:00:00 UTC",
> +		.ts = {.tv_sec = 4354819200LL, .tv_nsec = 0L},
> +		.time = cpu_to_le16(49021),
> +		.date = cpu_to_le16(65439),
> +		.cs = 199,
> +		.time_offset = 0,
> +	},
> +	{
> +		.name = "Clamp after time_offset=60 pushes 2107-12-31 23:30 UTC beyond 2107",
> +		.ts = {.tv_sec = 4354817400LL, .tv_nsec = 0L},
> +		.time = cpu_to_le16(49021),
> +		.date = cpu_to_le16(65439),
> +		.cs = 199,
> +		.time_offset = 60,
> +	},
> +};
> +
> +static struct fat_truncate_atime_testcase truncate_atime_test_cases[] = {
> +	{
> +		.name = "UTC atime truncates to 2004-02-29 00:00:00",
> +		.ts = {.tv_sec = 1078058096LL, .tv_nsec = 789000000L},
> +		.expected = {.tv_sec = 1078012800LL, .tv_nsec = 0L},
> +		.time_offset = 0,
> +	},
> +	{
> +		.name = "time_offset=-60 truncates 2004-02-29 00:30 UTC to previous local midnight",
> +		.ts = {.tv_sec = 1078014645LL, .tv_nsec = 123000000L},
> +		.expected = {.tv_sec = 1077930000LL, .tv_nsec = 0L},
> +		.time_offset = -60,
> +	},
> +	{
> +		.name = "time_offset=60 truncates 2004-02-29 23:30 UTC to next local midnight",
> +		.ts = {.tv_sec = 1078097445LL, .tv_nsec = 123000000L},
> +		.expected = {.tv_sec = 1078095600LL, .tv_nsec = 0L},
> +		.time_offset = 60,
> +	},
> +};
> +
>  static void time_testcase_desc(struct fat_timestamp_testcase *t,
>  			       char *desc)
>  {
>  	strscpy(desc, t->name, KUNIT_PARAM_DESC_SIZE);
>  }
>  
> +static void unix2fat_clamp_testcase_desc(struct fat_unix2fat_clamp_testcase *t,
> +					 char *desc)
> +{
> +	strscpy(desc, t->name, KUNIT_PARAM_DESC_SIZE);
> +}
> +
> +static void truncate_atime_testcase_desc(struct fat_truncate_atime_testcase *t,
> +					 char *desc)
> +{
> +	strscpy(desc, t->name, KUNIT_PARAM_DESC_SIZE);
> +}
> +
>  KUNIT_ARRAY_PARAM(fat_time, time_test_cases, time_testcase_desc);
> +KUNIT_ARRAY_PARAM(fat_unix2fat_clamp, unix2fat_clamp_test_cases,
> +		  unix2fat_clamp_testcase_desc);
> +KUNIT_ARRAY_PARAM(fat_truncate_atime, truncate_atime_test_cases,
> +		  truncate_atime_testcase_desc);
> +
> +static void fat_test_set_time_offset(struct msdos_sb_info *sbi, int time_offset)
> +{
> +	*sbi = (struct msdos_sb_info){};
> +	sbi->options.tz_set = 1;
> +	sbi->options.time_offset = time_offset;
> +}
>  
>  static void fat_time_fat2unix_test(struct kunit *test)
>  {
> @@ -135,8 +230,7 @@ static void fat_time_fat2unix_test(struct kunit *test)
>  	struct fat_timestamp_testcase *testcase =
>  		(struct fat_timestamp_testcase *)test->param_value;
>  
> -	fake_sb.options.tz_set = 1;
> -	fake_sb.options.time_offset = testcase->time_offset;
> +	fat_test_set_time_offset(&fake_sb, testcase->time_offset);
>  
>  	fat_time_fat2unix(&fake_sb, &ts,
>  			  testcase->time,
> @@ -160,18 +254,17 @@ static void fat_time_unix2fat_test(struct kunit *test)
>  	struct fat_timestamp_testcase *testcase =
>  		(struct fat_timestamp_testcase *)test->param_value;
>  
> -	fake_sb.options.tz_set = 1;
> -	fake_sb.options.time_offset = testcase->time_offset;
> +	fat_test_set_time_offset(&fake_sb, testcase->time_offset);
>  
>  	fat_time_unix2fat(&fake_sb, &testcase->ts,
>  			  &time, &date, &cs);
>  	KUNIT_EXPECT_EQ_MSG(test,
> -			    le16_to_cpu(testcase->time),
> -			    le16_to_cpu(time),
> +			    testcase->time,
> +			    time,
>  			    "Time mismatch\n");
>  	KUNIT_EXPECT_EQ_MSG(test,
> -			    le16_to_cpu(testcase->date),
> -			    le16_to_cpu(date),
> +			    testcase->date,
> +			    date,
>  			    "Date mismatch\n");
>  	KUNIT_EXPECT_EQ_MSG(test,
>  			    testcase->cs,
> @@ -179,10 +272,82 @@ static void fat_time_unix2fat_test(struct kunit *test)
>  			    "Centisecond mismatch\n");
>  }
>  
> +static void fat_time_unix2fat_clamp_test(struct kunit *test)
> +{
> +	static struct msdos_sb_info fake_sb;
> +	__le16 date, time;
> +	u8 cs;
> +	struct fat_unix2fat_clamp_testcase *testcase =
> +		(struct fat_unix2fat_clamp_testcase *)test->param_value;
> +
> +	fat_test_set_time_offset(&fake_sb, testcase->time_offset);
> +
> +	fat_time_unix2fat(&fake_sb, &testcase->ts, &time, &date, &cs);
> +	KUNIT_EXPECT_EQ_MSG(test,
> +			    testcase->time,
> +			    time,
> +			    "Clamped time mismatch\n");
> +	KUNIT_EXPECT_EQ_MSG(test,
> +			    testcase->date,
> +			    date,
> +			    "Clamped date mismatch\n");
> +	KUNIT_EXPECT_EQ_MSG(test,
> +			    testcase->cs,
> +			    cs,
> +			    "Clamped centisecond mismatch\n");
> +}
> +
> +static void fat_time_unix2fat_no_csec_test(struct kunit *test)
> +{
> +	static struct msdos_sb_info fake_sb;
> +	struct timespec64 ts = {
> +		.tv_sec = 946684799LL,
> +		.tv_nsec = 0L,
> +	};
> +	__le16 date, time;
> +
> +	fat_test_set_time_offset(&fake_sb, 0);
> +
> +	fat_time_unix2fat(&fake_sb, &ts, &time, &date, NULL);
> +	KUNIT_EXPECT_EQ_MSG(test,
> +			    49021,
> +			    le16_to_cpu(time),
> +			    "Time mismatch without centiseconds\n");
> +	KUNIT_EXPECT_EQ_MSG(test,
> +			    10143,
> +			    le16_to_cpu(date),
> +			    "Date mismatch without centiseconds\n");
> +}
> +
> +static void fat_truncate_atime_test(struct kunit *test)
> +{
> +	static struct msdos_sb_info fake_sb;
> +	struct timespec64 actual;
> +	struct fat_truncate_atime_testcase *testcase =
> +		(struct fat_truncate_atime_testcase *)test->param_value;
> +
> +	fat_test_set_time_offset(&fake_sb, testcase->time_offset);
> +
> +	actual = fat_truncate_atime(&fake_sb, &testcase->ts);
> +	KUNIT_EXPECT_EQ_MSG(test,
> +			    testcase->expected.tv_sec,
> +			    actual.tv_sec,
> +			    "Atime truncation seconds mismatch\n");
> +	KUNIT_EXPECT_EQ_MSG(test,
> +			    testcase->expected.tv_nsec,
> +			    actual.tv_nsec,
> +			    "Atime truncation nanoseconds mismatch\n");
> +}
> +
>  static struct kunit_case fat_test_cases[] = {
>  	KUNIT_CASE(fat_checksum_test),
>  	KUNIT_CASE_PARAM(fat_time_fat2unix_test, fat_time_gen_params),
>  	KUNIT_CASE_PARAM(fat_time_unix2fat_test, fat_time_gen_params),
> +	KUNIT_CASE_PARAM(fat_time_unix2fat_clamp_test,
> +			 fat_unix2fat_clamp_gen_params),
> +	KUNIT_CASE(fat_time_unix2fat_no_csec_test),
> +	KUNIT_CASE_PARAM(fat_truncate_atime_test,
> +			 fat_truncate_atime_gen_params),
>  	{},
>  };

-- 
OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>

  reply	other threads:[~2026-03-16  3:25 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-03-15 14:42 [PATCH] fat: add KUnit tests for timestamp conversion helpers aviv.daum
2026-03-15 17:38 ` OGAWA Hirofumi
2026-03-15 22:24 ` [PATCH v2] " aviv.daum
2026-03-16  3:25   ` OGAWA Hirofumi [this message]
2026-03-24  7:19     ` OGAWA Hirofumi
2026-03-24  7:48       ` Christian Brauner
2026-03-24  8:02         ` OGAWA Hirofumi
2026-03-24  7:47   ` Christian Brauner

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=87h5qgsbei.fsf@mail.parknet.co.jp \
    --to=hirofumi@mail.parknet.co.jp \
    --cc=aviv.daum@gmail.com \
    --cc=brauner@kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox