Commit 1cbeab1b authored by Iurii Zaikin's avatar Iurii Zaikin Committed by Shuah Khan
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ext4: add kunit test for decoding extended timestamps 

KUnit tests for decoding extended 64 bit timestamps that verify the
seconds part of [a/c/m] timestamps in ext4 inode structs are decoded
correctly.

Test data is derived from the table in the Inode Timestamps section of
Documentation/filesystems/ext4/inodes.rst.

KUnit tests run during boot and output the results to the debug log
in TAP format (http://testanything.org/

). Only useful for kernel devs
running KUnit test harness and are not for inclusion into a production
build.

Signed-off-by: default avatarIurii Zaikin <yzaikin@google.com>
Reviewed-by: default avatarTheodore Ts'o <tytso@mit.edu>
Reviewed-by: default avatarBrendan Higgins <brendanhiggins@google.com>
Tested-by: default avatarBrendan Higgins <brendanhiggins@google.com>
Reviewed-by: default avatarShuah Khan <skhan@linuxfoundation.org>
Signed-off-by: default avatarShuah Khan <skhan@linuxfoundation.org>
parent d460623c

fs/ext4/Kconfig

+17 −0
Original line number Diff line number Diff line
@@ -106,3 +106,20 @@ config EXT4_DEBUG 
	  If you select Y here, then you will be able to turn on debugging

	  with a command such as:

		echo 1 > /sys/module/ext4/parameters/mballoc_debug



config EXT4_KUNIT_TESTS

	bool "KUnit tests for ext4"

	select EXT4_FS

	depends on KUNIT

	help

	  This builds the ext4 KUnit tests.



	  KUnit tests run during boot and output the results to the debug log

	  in TAP format (http://testanything.org/). Only useful for kernel devs

	  running KUnit test harness and are not for inclusion into a production

	  build.



	  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.

fs/ext4/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -13,4 +13,5 @@ ext4-y := balloc.o bitmap.o block_validity.o dir.o ext4_jbd2.o extents.o \ 


ext4-$(CONFIG_EXT4_FS_POSIX_ACL)	+= acl.o

ext4-$(CONFIG_EXT4_FS_SECURITY)		+= xattr_security.o

ext4-$(CONFIG_EXT4_KUNIT_TESTS)		+= inode-test.o

ext4-$(CONFIG_FS_VERITY)		+= verity.o

fs/ext4/inode-test.c

0 → 100644
+272 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

/*

 * KUnit test of ext4 inode that verify the seconds part of [a/c/m]

 * timestamps in ext4 inode structs are decoded correctly.

 */



#include <kunit/test.h>

#include <linux/kernel.h>

#include <linux/time64.h>



#include "ext4.h"



/*

 * For constructing the nonnegative timestamp lower bound value.

 * binary: 00000000 00000000 00000000 00000000

 */

#define LOWER_MSB_0 0L

/*

 * For constructing the nonnegative timestamp upper bound value.

 * binary: 01111111 11111111 11111111 11111111

 *

 */

#define UPPER_MSB_0 0x7fffffffL

/*

 * For constructing the negative timestamp lower bound value.

 * binary: 10000000 00000000 00000000 00000000

 */

#define LOWER_MSB_1 (-0x80000000L)

/*

 * For constructing the negative timestamp upper bound value.

 * binary: 11111111 11111111 11111111 11111111

 */

#define UPPER_MSB_1 (-1L)

/*

 * Upper bound for nanoseconds value supported by the encoding.

 * binary: 00111111 11111111 11111111 11111111

 */

#define MAX_NANOSECONDS ((1L << 30) - 1)



#define CASE_NAME_FORMAT "%s: msb:%x lower_bound:%x extra_bits: %x"



#define LOWER_BOUND_NEG_NO_EXTRA_BITS_CASE\

	"1901-12-13 Lower bound of 32bit < 0 timestamp, no extra bits"

#define UPPER_BOUND_NEG_NO_EXTRA_BITS_CASE\

	"1969-12-31 Upper bound of 32bit < 0 timestamp, no extra bits"

#define LOWER_BOUND_NONNEG_NO_EXTRA_BITS_CASE\

	"1970-01-01 Lower bound of 32bit >=0 timestamp, no extra bits"

#define UPPER_BOUND_NONNEG_NO_EXTRA_BITS_CASE\

	"2038-01-19 Upper bound of 32bit >=0 timestamp, no extra bits"

#define LOWER_BOUND_NEG_LO_1_CASE\

	"2038-01-19 Lower bound of 32bit <0 timestamp, lo extra sec bit on"

#define UPPER_BOUND_NEG_LO_1_CASE\

	"2106-02-07 Upper bound of 32bit <0 timestamp, lo extra sec bit on"

#define LOWER_BOUND_NONNEG_LO_1_CASE\

	"2106-02-07 Lower bound of 32bit >=0 timestamp, lo extra sec bit on"

#define UPPER_BOUND_NONNEG_LO_1_CASE\

	"2174-02-25 Upper bound of 32bit >=0 timestamp, lo extra sec bit on"

#define LOWER_BOUND_NEG_HI_1_CASE\

	"2174-02-25 Lower bound of 32bit <0 timestamp, hi extra sec bit on"

#define UPPER_BOUND_NEG_HI_1_CASE\

	"2242-03-16 Upper bound of 32bit <0 timestamp, hi extra sec bit on"

#define LOWER_BOUND_NONNEG_HI_1_CASE\

	"2242-03-16 Lower bound of 32bit >=0 timestamp, hi extra sec bit on"

#define UPPER_BOUND_NONNEG_HI_1_CASE\

	"2310-04-04 Upper bound of 32bit >=0 timestamp, hi extra sec bit on"

#define UPPER_BOUND_NONNEG_HI_1_NS_1_CASE\

	"2310-04-04 Upper bound of 32bit>=0 timestamp, hi extra sec bit 1. 1 ns"

#define LOWER_BOUND_NONNEG_HI_1_NS_MAX_CASE\

	"2378-04-22 Lower bound of 32bit>= timestamp. Extra sec bits 1. Max ns"

#define LOWER_BOUND_NONNEG_EXTRA_BITS_1_CASE\

	"2378-04-22 Lower bound of 32bit >=0 timestamp. All extra sec bits on"

#define UPPER_BOUND_NONNEG_EXTRA_BITS_1_CASE\

	"2446-05-10 Upper bound of 32bit >=0 timestamp. All extra sec bits on"



struct timestamp_expectation {

	const char *test_case_name;

	struct timespec64 expected;

	u32 extra_bits;

	bool msb_set;

	bool lower_bound;

};



static time64_t get_32bit_time(const struct timestamp_expectation * const test)

{

	if (test->msb_set) {

		if (test->lower_bound)

			return LOWER_MSB_1;



		return UPPER_MSB_1;

	}



	if (test->lower_bound)

		return LOWER_MSB_0;

	return UPPER_MSB_0;

}





/*

 *  Test data is derived from the table in the Inode Timestamps section of

 *  Documentation/filesystems/ext4/inodes.rst.

 */

static void inode_test_xtimestamp_decoding(struct kunit *test)

{

	const struct timestamp_expectation test_data[] = {

		{

			.test_case_name = LOWER_BOUND_NEG_NO_EXTRA_BITS_CASE,

			.msb_set = true,

			.lower_bound = true,

			.extra_bits = 0,

			.expected = {.tv_sec = -0x80000000LL, .tv_nsec = 0L},

		},



		{

			.test_case_name = UPPER_BOUND_NEG_NO_EXTRA_BITS_CASE,

			.msb_set = true,

			.lower_bound = false,

			.extra_bits = 0,

			.expected = {.tv_sec = -1LL, .tv_nsec = 0L},

		},



		{

			.test_case_name = LOWER_BOUND_NONNEG_NO_EXTRA_BITS_CASE,

			.msb_set = false,

			.lower_bound = true,

			.extra_bits = 0,

			.expected = {0LL, 0L},

		},



		{

			.test_case_name = UPPER_BOUND_NONNEG_NO_EXTRA_BITS_CASE,

			.msb_set = false,

			.lower_bound = false,

			.extra_bits = 0,

			.expected = {.tv_sec = 0x7fffffffLL, .tv_nsec = 0L},

		},



		{

			.test_case_name = LOWER_BOUND_NEG_LO_1_CASE,

			.msb_set = true,

			.lower_bound = true,

			.extra_bits = 1,

			.expected = {.tv_sec = 0x80000000LL, .tv_nsec = 0L},

		},



		{

			.test_case_name = UPPER_BOUND_NEG_LO_1_CASE,

			.msb_set = true,

			.lower_bound = false,

			.extra_bits = 1,

			.expected = {.tv_sec = 0xffffffffLL, .tv_nsec = 0L},

		},



		{

			.test_case_name = LOWER_BOUND_NONNEG_LO_1_CASE,

			.msb_set = false,

			.lower_bound = true,

			.extra_bits = 1,

			.expected = {.tv_sec = 0x100000000LL, .tv_nsec = 0L},

		},



		{

			.test_case_name = UPPER_BOUND_NONNEG_LO_1_CASE,

			.msb_set = false,

			.lower_bound = false,

			.extra_bits = 1,

			.expected = {.tv_sec = 0x17fffffffLL, .tv_nsec = 0L},

		},



		{

			.test_case_name = LOWER_BOUND_NEG_HI_1_CASE,

			.msb_set = true,

			.lower_bound = true,

			.extra_bits =  2,

			.expected = {.tv_sec = 0x180000000LL, .tv_nsec = 0L},

		},



		{

			.test_case_name = UPPER_BOUND_NEG_HI_1_CASE,

			.msb_set = true,

			.lower_bound = false,

			.extra_bits = 2,

			.expected = {.tv_sec = 0x1ffffffffLL, .tv_nsec = 0L},

		},



		{

			.test_case_name = LOWER_BOUND_NONNEG_HI_1_CASE,

			.msb_set = false,

			.lower_bound = true,

			.extra_bits = 2,

			.expected = {.tv_sec = 0x200000000LL, .tv_nsec = 0L},

		},



		{

			.test_case_name = UPPER_BOUND_NONNEG_HI_1_CASE,

			.msb_set = false,

			.lower_bound = false,

			.extra_bits = 2,

			.expected = {.tv_sec = 0x27fffffffLL, .tv_nsec = 0L},

		},



		{

			.test_case_name = UPPER_BOUND_NONNEG_HI_1_NS_1_CASE,

			.msb_set = false,

			.lower_bound = false,

			.extra_bits = 6,

			.expected = {.tv_sec = 0x27fffffffLL, .tv_nsec = 1L},

		},



		{

			.test_case_name = LOWER_BOUND_NONNEG_HI_1_NS_MAX_CASE,

			.msb_set = false,

			.lower_bound = true,

			.extra_bits = 0xFFFFFFFF,

			.expected = {.tv_sec = 0x300000000LL,

				     .tv_nsec = MAX_NANOSECONDS},

		},



		{

			.test_case_name = LOWER_BOUND_NONNEG_EXTRA_BITS_1_CASE,

			.msb_set = false,

			.lower_bound = true,

			.extra_bits = 3,

			.expected = {.tv_sec = 0x300000000LL, .tv_nsec = 0L},

		},



		{

			.test_case_name = UPPER_BOUND_NONNEG_EXTRA_BITS_1_CASE,

			.msb_set = false,

			.lower_bound = false,

			.extra_bits = 3,

			.expected = {.tv_sec = 0x37fffffffLL, .tv_nsec = 0L},

		}

	};



	struct timespec64 timestamp;

	int i;



	for (i = 0; i < ARRAY_SIZE(test_data); ++i) {

		timestamp.tv_sec = get_32bit_time(&test_data[i]);

		ext4_decode_extra_time(&timestamp,

				       cpu_to_le32(test_data[i].extra_bits));



		KUNIT_EXPECT_EQ_MSG(test,

				    test_data[i].expected.tv_sec,

				    timestamp.tv_sec,

				    CASE_NAME_FORMAT,

				    test_data[i].test_case_name,

				    test_data[i].msb_set,

				    test_data[i].lower_bound,

				    test_data[i].extra_bits);

		KUNIT_EXPECT_EQ_MSG(test,

				    test_data[i].expected.tv_nsec,

				    timestamp.tv_nsec,

				    CASE_NAME_FORMAT,

				    test_data[i].test_case_name,

				    test_data[i].msb_set,

				    test_data[i].lower_bound,

				    test_data[i].extra_bits);

	}

}



static struct kunit_case ext4_inode_test_cases[] = {

	KUNIT_CASE(inode_test_xtimestamp_decoding),

	{}

};



static struct kunit_suite ext4_inode_test_suite = {

	.name = "ext4_inode_test",

	.test_cases = ext4_inode_test_cases,

};



kunit_test_suite(ext4_inode_test_suite);

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