ext4: add kunit test for decoding extended timestamps
authorIurii Zaikin <yzaikin@google.com>
Thu, 17 Oct 2019 22:12:33 +0000 (15:12 -0700)
committerShuah Khan <skhan@linuxfoundation.org>
Wed, 23 Oct 2019 16:28:23 +0000 (10:28 -0600)
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>
fs/ext4/Kconfig
fs/ext4/Makefile
fs/ext4/inode-test.c [new file with mode: 0644]

index cbb5ca830e57f322e2248cf077d124b4296cc6b7..ef42ab040905731d1d574446c38d23d0fd5e6b6f 100644 (file)
@@ -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.
index b17ddc229ac5f5123a17469ce5c60ef95ed6fda4..840b91d040f1bd72b99406c013e4e64e354817b2 100644 (file)
@@ -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
diff --git a/fs/ext4/inode-test.c b/fs/ext4/inode-test.c
new file mode 100644 (file)
index 0000000..92a9da1
--- /dev/null
@@ -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(&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);