scsi: core: Add kunit tests for scsi_check_passthrough()

Add some kunit tests for scsi_check_passthrough() so we can easily make
sure we are hitting the cases for which it's difficult to replicate in
hardware or even scsi_debug.

Signed-off-by: Mike Christie <michael.christie@oracle.com>
Link: https://lore.kernel.org/r/20240123002220.129141-20-michael.christie@oracle.com
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

3 files changed, 343 insertions, 0 deletions

diff --git a/drivers/scsi/Kconfig b/drivers/scsi/Kconfig
index addac7fbe37b98..e20af95a912b79 100644
--- a/drivers/scsi/Kconfig
+++ b/drivers/scsi/Kconfig
@@ -67,6 +67,15 @@ config SCSI_PROC_FS
 
 	  If unsure say Y.
 
+config SCSI_LIB_KUNIT_TEST
+	tristate "KUnit tests for SCSI Mid Layer's scsi_lib" if !KUNIT_ALL_TESTS
+	depends on KUNIT
+	default KUNIT_ALL_TESTS
+	help
+	  Run SCSI Mid Layer's KUnit tests for scsi_lib.
+
+	  If unsure say N.
+
 comment "SCSI support type (disk, tape, CD-ROM)"
 	depends on SCSI
 
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 8a79e4f3663619..c726f2025c59b2 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -3434,3 +3434,7 @@ void scsi_build_sense(struct scsi_cmnd *scmd, int desc, u8 key, u8 asc, u8 ascq)
 	scmd->result = SAM_STAT_CHECK_CONDITION;
 }
 EXPORT_SYMBOL_GPL(scsi_build_sense);
+
+#ifdef CONFIG_SCSI_KUNIT_TEST
+#include "scsi_lib_test.c"
+#endif
diff --git a/drivers/scsi/scsi_lib_test.c b/drivers/scsi/scsi_lib_test.c
new file mode 100644
index 00000000000000..99834426a100a7
--- /dev/null
+++ b/drivers/scsi/scsi_lib_test.c
@@ -0,0 +1,330 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * KUnit tests for scsi_lib.c.
+ *
+ * Copyright (C) 2023, Oracle Corporation
+ */
+#include <kunit/test.h>
+
+#include <scsi/scsi_proto.h>
+#include <scsi/scsi_cmnd.h>
+#include <scsi/scsi_device.h>
+
+#define SCSI_LIB_TEST_MAX_ALLOWED 3
+#define SCSI_LIB_TEST_TOTAL_MAX_ALLOWED 5
+
+static void scsi_lib_test_multiple_sense(struct kunit *test)
+{
+	struct scsi_failure multiple_sense_failure_defs[] = {
+		{
+			.sense = DATA_PROTECT,
+			.asc = 0x1,
+			.ascq = 0x1,
+			.result = SAM_STAT_CHECK_CONDITION,
+		},
+		{
+			.sense = UNIT_ATTENTION,
+			.asc = 0x11,
+			.ascq = 0x0,
+			.allowed = SCSI_LIB_TEST_MAX_ALLOWED,
+			.result = SAM_STAT_CHECK_CONDITION,
+		},
+		{
+			.sense = NOT_READY,
+			.asc = 0x11,
+			.ascq = 0x22,
+			.allowed = SCSI_LIB_TEST_MAX_ALLOWED,
+			.result = SAM_STAT_CHECK_CONDITION,
+		},
+		{
+			.sense = ABORTED_COMMAND,
+			.asc = 0x11,
+			.ascq = SCMD_FAILURE_ASCQ_ANY,
+			.allowed = SCSI_LIB_TEST_MAX_ALLOWED,
+			.result = SAM_STAT_CHECK_CONDITION,
+		},
+		{
+			.sense = HARDWARE_ERROR,
+			.asc = SCMD_FAILURE_ASC_ANY,
+			.allowed = SCSI_LIB_TEST_MAX_ALLOWED,
+			.result = SAM_STAT_CHECK_CONDITION,
+		},
+		{
+			.sense = ILLEGAL_REQUEST,
+			.asc = 0x91,
+			.ascq = 0x36,
+			.allowed = SCSI_LIB_TEST_MAX_ALLOWED,
+			.result = SAM_STAT_CHECK_CONDITION,
+		},
+		{}
+	};
+	struct scsi_failures failures = {
+		.failure_definitions = multiple_sense_failure_defs,
+	};
+	u8 sense[SCSI_SENSE_BUFFERSIZE] = {};
+	struct scsi_cmnd sc = {
+		.sense_buffer = sense,
+	};
+	int i;
+
+	/* Match end of array */
+	scsi_build_sense(&sc, 0, ILLEGAL_REQUEST, 0x91, 0x36);
+	KUNIT_EXPECT_EQ(test, -EAGAIN, scsi_check_passthrough(&sc, &failures));
+	/* Basic match in array */
+	scsi_build_sense(&sc, 0, UNIT_ATTENTION, 0x11, 0x0);
+	KUNIT_EXPECT_EQ(test, -EAGAIN, scsi_check_passthrough(&sc, &failures));
+	/* No matching sense entry */
+	scsi_build_sense(&sc, 0, MISCOMPARE, 0x11, 0x11);
+	KUNIT_EXPECT_EQ(test, 0, scsi_check_passthrough(&sc, &failures));
+	/* Match using SCMD_FAILURE_ASCQ_ANY */
+	scsi_build_sense(&sc, 0, ABORTED_COMMAND, 0x11, 0x22);
+	KUNIT_EXPECT_EQ(test, -EAGAIN, scsi_check_passthrough(&sc, &failures));
+	/* Fail to match */
+	scsi_build_sense(&sc, 0, ABORTED_COMMAND, 0x22, 0x22);
+	KUNIT_EXPECT_EQ(test, 0, scsi_check_passthrough(&sc, &failures));
+	/* Match using SCMD_FAILURE_ASC_ANY */
+	scsi_build_sense(&sc, 0, HARDWARE_ERROR, 0x11, 0x22);
+	KUNIT_EXPECT_EQ(test, -EAGAIN, scsi_check_passthrough(&sc, &failures));
+	/* No matching status entry */
+	sc.result = SAM_STAT_RESERVATION_CONFLICT;
+	KUNIT_EXPECT_EQ(test, 0, scsi_check_passthrough(&sc, &failures));
+
+	/* Test hitting allowed limit */
+	scsi_build_sense(&sc, 0, NOT_READY, 0x11, 0x22);
+	for (i = 0; i < SCSI_LIB_TEST_MAX_ALLOWED; i++)
+		KUNIT_EXPECT_EQ(test, -EAGAIN, scsi_check_passthrough(&sc,
+				&failures));
+	KUNIT_EXPECT_EQ(test, 0, scsi_check_passthrough(&sc, &failures));
+
+	/* reset retries so we can retest */
+	failures.failure_definitions = multiple_sense_failure_defs;
+	scsi_failures_reset_retries(&failures);
+
+	/* Test no retries allowed */
+	scsi_build_sense(&sc, 0, DATA_PROTECT, 0x1, 0x1);
+	KUNIT_EXPECT_EQ(test, 0, scsi_check_passthrough(&sc, &failures));
+}
+
+static void scsi_lib_test_any_sense(struct kunit *test)
+{
+	struct scsi_failure any_sense_failure_defs[] = {
+		{
+			.result = SCMD_FAILURE_SENSE_ANY,
+			.allowed = SCSI_LIB_TEST_MAX_ALLOWED,
+		},
+		{}
+	};
+	struct scsi_failures failures = {
+		.failure_definitions = any_sense_failure_defs,
+	};
+	u8 sense[SCSI_SENSE_BUFFERSIZE] = {};
+	struct scsi_cmnd sc = {
+		.sense_buffer = sense,
+	};
+
+	/* Match using SCMD_FAILURE_SENSE_ANY */
+	failures.failure_definitions = any_sense_failure_defs;
+	scsi_build_sense(&sc, 0, MEDIUM_ERROR, 0x11, 0x22);
+	KUNIT_EXPECT_EQ(test, -EAGAIN, scsi_check_passthrough(&sc, &failures));
+}
+
+static void scsi_lib_test_host(struct kunit *test)
+{
+	struct scsi_failure retryable_host_failure_defs[] = {
+		{
+			.result = DID_TRANSPORT_DISRUPTED << 16,
+			.allowed = SCSI_LIB_TEST_MAX_ALLOWED,
+		},
+		{
+			.result = DID_TIME_OUT << 16,
+			.allowed = SCSI_LIB_TEST_MAX_ALLOWED,
+		},
+		{}
+	};
+	struct scsi_failures failures = {
+		.failure_definitions = retryable_host_failure_defs,
+	};
+	u8 sense[SCSI_SENSE_BUFFERSIZE] = {};
+	struct scsi_cmnd sc = {
+		.sense_buffer = sense,
+	};
+
+	/* No matching host byte entry */
+	failures.failure_definitions = retryable_host_failure_defs;
+	sc.result = DID_NO_CONNECT << 16;
+	KUNIT_EXPECT_EQ(test, 0, scsi_check_passthrough(&sc, &failures));
+	/* Matching host byte entry */
+	sc.result = DID_TIME_OUT << 16;
+	KUNIT_EXPECT_EQ(test, -EAGAIN, scsi_check_passthrough(&sc, &failures));
+}
+
+static void scsi_lib_test_any_failure(struct kunit *test)
+{
+	struct scsi_failure any_failure_defs[] = {
+		{
+			.result = SCMD_FAILURE_RESULT_ANY,
+			.allowed = SCSI_LIB_TEST_MAX_ALLOWED,
+		},
+		{}
+	};
+	struct scsi_failures failures = {
+		.failure_definitions = any_failure_defs,
+	};
+	u8 sense[SCSI_SENSE_BUFFERSIZE] = {};
+	struct scsi_cmnd sc = {
+		.sense_buffer = sense,
+	};
+
+	/* Match SCMD_FAILURE_RESULT_ANY */
+	failures.failure_definitions = any_failure_defs;
+	sc.result = DID_TRANSPORT_FAILFAST << 16;
+	KUNIT_EXPECT_EQ(test, -EAGAIN, scsi_check_passthrough(&sc, &failures));
+}
+
+static void scsi_lib_test_any_status(struct kunit *test)
+{
+	struct scsi_failure any_status_failure_defs[] = {
+		{
+			.result = SCMD_FAILURE_STAT_ANY,
+			.allowed = SCSI_LIB_TEST_MAX_ALLOWED,
+		},
+		{}
+	};
+	struct scsi_failures failures = {
+		.failure_definitions = any_status_failure_defs,
+	};
+	u8 sense[SCSI_SENSE_BUFFERSIZE] = {};
+	struct scsi_cmnd sc = {
+		.sense_buffer = sense,
+	};
+
+	/* Test any status handling */
+	failures.failure_definitions = any_status_failure_defs;
+	sc.result = SAM_STAT_RESERVATION_CONFLICT;
+	KUNIT_EXPECT_EQ(test, -EAGAIN, scsi_check_passthrough(&sc, &failures));
+}
+
+static void scsi_lib_test_total_allowed(struct kunit *test)
+{
+	struct scsi_failure total_allowed_defs[] = {
+		{
+			.sense = UNIT_ATTENTION,
+			.asc = SCMD_FAILURE_ASC_ANY,
+			.ascq = SCMD_FAILURE_ASCQ_ANY,
+			.result = SAM_STAT_CHECK_CONDITION,
+		},
+		/* Fail all CCs except the UA above */
+		{
+			.sense = SCMD_FAILURE_SENSE_ANY,
+			.result = SAM_STAT_CHECK_CONDITION,
+		},
+		/* Retry any other errors not listed above */
+		{
+			.result = SCMD_FAILURE_RESULT_ANY,
+		},
+		{}
+	};
+	struct scsi_failures failures = {
+		.failure_definitions = total_allowed_defs,
+	};
+	u8 sense[SCSI_SENSE_BUFFERSIZE] = {};
+	struct scsi_cmnd sc = {
+		.sense_buffer = sense,
+	};
+	int i;
+
+	/* Test total_allowed */
+	failures.failure_definitions = total_allowed_defs;
+	scsi_failures_reset_retries(&failures);
+	failures.total_allowed = SCSI_LIB_TEST_TOTAL_MAX_ALLOWED;
+
+	scsi_build_sense(&sc, 0, UNIT_ATTENTION, 0x28, 0x0);
+	for (i = 0; i < SCSI_LIB_TEST_TOTAL_MAX_ALLOWED; i++)
+		/* Retry since we under the total_allowed limit */
+		KUNIT_EXPECT_EQ(test, -EAGAIN, scsi_check_passthrough(&sc,
+				&failures));
+	sc.result = DID_TIME_OUT << 16;
+	/* We have now hit the total_allowed limit so no more retries */
+	KUNIT_EXPECT_EQ(test, 0, scsi_check_passthrough(&sc, &failures));
+}
+
+static void scsi_lib_test_mixed_total(struct kunit *test)
+{
+	struct scsi_failure mixed_total_defs[] = {
+		{
+			.sense = UNIT_ATTENTION,
+			.asc = 0x28,
+			.result = SAM_STAT_CHECK_CONDITION,
+		},
+		{
+			.sense = UNIT_ATTENTION,
+			.asc = 0x29,
+			.result = SAM_STAT_CHECK_CONDITION,
+		},
+		{
+			.allowed = 1,
+			.result = DID_TIME_OUT << 16,
+		},
+		{}
+	};
+	u8 sense[SCSI_SENSE_BUFFERSIZE] = {};
+	struct scsi_failures failures = {
+		.failure_definitions = mixed_total_defs,
+	};
+	struct scsi_cmnd sc = {
+		.sense_buffer = sense,
+	};
+	int i;
+
+	/*
+	 * Test total_allowed when there is a mix of per failure allowed
+	 * and total_allowed limits.
+	 */
+	failures.failure_definitions = mixed_total_defs;
+	scsi_failures_reset_retries(&failures);
+	failures.total_allowed = SCSI_LIB_TEST_TOTAL_MAX_ALLOWED;
+
+	scsi_build_sense(&sc, 0, UNIT_ATTENTION, 0x28, 0x0);
+	for (i = 0; i < SCSI_LIB_TEST_TOTAL_MAX_ALLOWED; i++)
+		/* Retry since we under the total_allowed limit */
+		KUNIT_EXPECT_EQ(test, -EAGAIN, scsi_check_passthrough(&sc,
+				&failures));
+	/* Do not retry since we are now over total_allowed limit */
+	KUNIT_EXPECT_EQ(test, 0, scsi_check_passthrough(&sc, &failures));
+
+	scsi_failures_reset_retries(&failures);
+	scsi_build_sense(&sc, 0, UNIT_ATTENTION, 0x28, 0x0);
+	for (i = 0; i < SCSI_LIB_TEST_TOTAL_MAX_ALLOWED; i++)
+		/* Retry since we under the total_allowed limit */
+		KUNIT_EXPECT_EQ(test, -EAGAIN, scsi_check_passthrough(&sc,
+				&failures));
+	sc.result = DID_TIME_OUT << 16;
+	/* Retry because this failure has a per failure limit */
+	KUNIT_EXPECT_EQ(test, -EAGAIN, scsi_check_passthrough(&sc, &failures));
+	scsi_build_sense(&sc, 0, UNIT_ATTENTION, 0x29, 0x0);
+	/* total_allowed is now hit so no more retries */
+	KUNIT_EXPECT_EQ(test, 0, scsi_check_passthrough(&sc, &failures));
+}
+
+static void scsi_lib_test_check_passthough(struct kunit *test)
+{
+	scsi_lib_test_multiple_sense(test);
+	scsi_lib_test_any_sense(test);
+	scsi_lib_test_host(test);
+	scsi_lib_test_any_failure(test);
+	scsi_lib_test_any_status(test);
+	scsi_lib_test_total_allowed(test);
+	scsi_lib_test_mixed_total(test);
+}
+
+static struct kunit_case scsi_lib_test_cases[] = {
+	KUNIT_CASE(scsi_lib_test_check_passthough),
+	{}
+};
+
+static struct kunit_suite scsi_lib_test_suite = {
+	.name = "scsi_lib",
+	.test_cases = scsi_lib_test_cases,
+};
+
+kunit_test_suite(scsi_lib_test_suite);