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: Iurii Zaikin <yzaikin@google.com>
Reviewed-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Tested-by: Brendan Higgins <brendanhiggins@google.com>
Reviewed-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
diff --git a/fs/ext4/inode-test.c b/fs/ext4/inode-test.c
new file mode 100644
index 0000000..92a9da1
--- /dev/null
+++ b/fs/ext4/inode-test.c
@@ -0,0 +1,272 @@
+// 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(×tamp,
+ 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);
