[PATCH v15 07/19] scsi: core: Add unit tests for scsi_call_prepare_resubmit()

Bart Van Assche
2023-11-14T21:18:42Z

Triggering all code paths in scsi_call_prepare_resubmit() via manual
testing is difficult. Hence add unit tests for this function.

Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Damien Le Moal <dlemoal@kernel.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
---
drivers/scsi/Kconfig | 5 +
drivers/scsi/scsi_error.c | 4 +
drivers/scsi/scsi_error_test.c | 233 +++++++++++++++++++++++++++++++++
3 files changed, 242 insertions(+)
create mode 100644 drivers/scsi/scsi_error_test.c

diff --git a/drivers/scsi/Kconfig b/drivers/scsi/Kconfig
index addac7fbe37b..2e57afdbbc4d 100644
--- a/drivers/scsi/Kconfig
+++ b/drivers/scsi/Kconfig
@@ -232,6 +232,11 @@ config SCSI_SCAN_ASYNC
Note that this setting also affects whether resuming from
system suspend will be performed asynchronously.

+config SCSI_ERROR_TEST
+ tristate "scsi_error.c unit tests" if !KUNIT_ALL_TESTS
+ depends on SCSI && KUNIT
+ default KUNIT_ALL_TESTS
+
menu "SCSI Transports"
depends on SCSI

diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c
index 4214d7b79b06..3a2643293abf 100644
--- a/drivers/scsi/scsi_error.c
+++ b/drivers/scsi/scsi_error.c
@@ -2621,3 +2621,7 @@ bool scsi_get_sense_info_fld(const u8 *sense_buffer, int sb_len,
}
}
EXPORT_SYMBOL(scsi_get_sense_info_fld);
+
+#ifdef CONFIG_SCSI_ERROR_TEST
+#include "scsi_error_test.c"
+#endif
diff --git a/drivers/scsi/scsi_error_test.c b/drivers/scsi/scsi_error_test.c
new file mode 100644
index 000000000000..46362766ad48
--- /dev/null
+++ b/drivers/scsi/scsi_error_test.c
@@ -0,0 +1,233 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright 2023 Google LLC
+ */
+#include <kunit/test.h>
+#include <linux/cleanup.h>
+#include <scsi/scsi_cmnd.h>
+#include <scsi/scsi_driver.h>
+#include <scsi/scsi_host.h>
+
+#define ALLOC(type, ...) \
+ ({ \
+ type *obj; \
+ obj = kmalloc(sizeof(*obj), GFP_KERNEL); \
+ if (obj) \
+ *obj = (type){ __VA_ARGS__ }; \
+ obj; \
+ })
+
+#define ALLOC_DISK(...) ALLOC(struct gendisk, __VA_ARGS__)
+
+#define ALLOC_Q(...) ALLOC(struct request_queue, __VA_ARGS__)
+
+#define ALLOC_SDEV(...) ALLOC(struct scsi_device, __VA_ARGS__)
+
+#define ALLOC_CMD(...) ALLOC(struct rq_and_cmd, __VA_ARGS__)
+
+static struct kunit *kunit_test;
+
+static void uld_prepare_resubmit(struct list_head *cmd_list)
+{
+ /* This function must not be called. */
+ KUNIT_EXPECT_TRUE(kunit_test, false);
+}
+
+/*
+ * Verify that .eh_prepare_resubmit() is not called if needs_prepare_resubmit is
+ * false.
+ */
+static void test_prepare_resubmit1(struct kunit *test)
+{
+ struct gendisk *disk __free(kfree) = ALLOC_DISK();
+ struct request_queue *q __free(kfree) = ALLOC_Q(
+ .limits = {
+ .driver_preserves_write_order = false,
+ .use_zone_write_lock = true,
+ .zoned = BLK_ZONED_HM,
+ }
+ );
+ static struct scsi_driver uld = {
+ .eh_prepare_resubmit = uld_prepare_resubmit,
+ };
+ static const struct scsi_host_template host_template;
+ static struct Scsi_Host host = {
+ .hostt = &host_template,
+ };
+ struct scsi_device *dev __free(kfree) = ALLOC_SDEV(
+ .request_queue = q,
+ .sdev_gendev.driver = &uld.gendrv,
+ .host = &host,
+ );
+ struct rq_and_cmd {
+ struct request rq;
+ struct scsi_cmnd cmd;
+ } *cmd1 __free(kfree) = NULL, *cmd2 __free(kfree);
+ LIST_HEAD(cmd_list);
+
+ BUILD_BUG_ON(scsi_cmd_to_rq(&cmd1->cmd) != &cmd1->rq);
+
+ q->disk = disk;
+ disk->queue = q;
+ cmd1 = ALLOC_CMD(
+ .rq = {
+ .q = q,
+ .cmd_flags = REQ_OP_WRITE,
+ .__sector = 2,
+ },
+ .cmd.device = dev,
+ );
+ cmd2 = ALLOC_CMD(
+ .rq = {
+ .q = q,
+ .cmd_flags = REQ_OP_WRITE,
+ .__sector = 1,
+ },
+ .cmd.device = dev,
+ );
+ list_add_tail(&cmd1->cmd.eh_entry, &cmd_list);
+ list_add_tail(&cmd2->cmd.eh_entry, &cmd_list);
+
+ KUNIT_EXPECT_EQ(test, list_count_nodes(&cmd_list), 2);
+ kunit_test = test;
+ scsi_call_prepare_resubmit(&host, &cmd_list);
+ kunit_test = NULL;
+ KUNIT_EXPECT_EQ(test, list_count_nodes(&cmd_list), 2);
+ KUNIT_EXPECT_PTR_EQ(test, cmd_list.next, &cmd1->cmd.eh_entry);
+ KUNIT_EXPECT_PTR_EQ(test, cmd_list.next->next, &cmd2->cmd.eh_entry);
+}
+
+static struct scsi_driver *uld1, *uld2, *uld3;
+
+static void uld1_prepare_resubmit(struct list_head *cmd_list)
+{
+ struct scsi_cmnd *cmd;
+
+ KUNIT_EXPECT_EQ(kunit_test, list_count_nodes(cmd_list), 2);
+ list_for_each_entry(cmd, cmd_list, eh_entry)
+ KUNIT_EXPECT_PTR_EQ(kunit_test, scsi_cmd_to_driver(cmd), uld1);
+}
+
+static void uld2_prepare_resubmit(struct list_head *cmd_list)
+{
+ struct scsi_cmnd *cmd;
+
+ KUNIT_EXPECT_EQ(kunit_test, list_count_nodes(cmd_list), 2);
+ list_for_each_entry(cmd, cmd_list, eh_entry)
+ KUNIT_EXPECT_PTR_EQ(kunit_test, scsi_cmd_to_driver(cmd), uld2);
+}
+
+static void test_prepare_resubmit2(struct kunit *test)
+{
+ static const struct scsi_host_template host_template = {
+ .needs_prepare_resubmit = true,
+ };
+ static struct Scsi_Host host = {
+ .hostt = &host_template,
+ };
+ struct gendisk *disk __free(kfree);
+ struct request_queue *q __free(kfree) =
+ ALLOC_Q(.limits = {
+ .driver_preserves_write_order = true,
+ .use_zone_write_lock = false,
+ .zoned = BLK_ZONED_HM,
+ });
+ struct rq_and_cmd {
+ struct request rq;
+ struct scsi_cmnd cmd;
+ } *cmd1 __free(kfree), *cmd2 __free(kfree), *cmd3 __free(kfree),
+ *cmd4 __free(kfree), *cmd5 __free(kfree), *cmd6 __free(kfree);
+ struct scsi_device *dev1 __free(kfree), *dev2 __free(kfree),
+ *dev3 __free(kfree);
+ struct scsi_driver *uld __free(kfree);
+ LIST_HEAD(cmd_list);
+
+ BUILD_BUG_ON(scsi_cmd_to_rq(&cmd1->cmd) != &cmd1->rq);
+
+ uld = kzalloc(3 * sizeof(*uld), GFP_KERNEL);
+ uld1 = &uld[0];
+ uld1->eh_prepare_resubmit = uld1_prepare_resubmit;
+ uld2 = &uld[1];
+ uld2->eh_prepare_resubmit = uld2_prepare_resubmit;
+ uld3 = &uld[2];
+ disk = ALLOC_DISK();
+ disk->queue = q;
+ q->disk = disk;
+ dev1 = ALLOC_SDEV(.sdev_gendev.driver = &uld1->gendrv,
+ .request_queue = q, .host = &host);
+ dev2 = ALLOC_SDEV(.sdev_gendev.driver = &uld2->gendrv,
+ .request_queue = q, .host = &host);
+ dev3 = ALLOC_SDEV(.sdev_gendev.driver = &uld3->gendrv,
+ .request_queue = q, .host = &host);
+ cmd1 = ALLOC_CMD(
+ .rq = {
+ .q = q,
+ .cmd_flags = REQ_OP_WRITE,
+ .__sector = 3,
+ },
+ .cmd.device = dev1,
+ );
+ cmd2 = ALLOC_CMD();
+ *cmd2 = *cmd1;
+ cmd2->rq.__sector = 4;
+ cmd3 = ALLOC_CMD(
+ .rq = {
+ .q = q,
+ .cmd_flags = REQ_OP_WRITE,
+ .__sector = 1,
+ },
+ .cmd.device = dev2,
+ );
+ cmd4 = kmemdup(cmd3, sizeof(*cmd3), GFP_KERNEL);
+ cmd4->rq.__sector = 2;
+ cmd5 = ALLOC_CMD(
+ .rq = {
+ .q = q,
+ .cmd_flags = REQ_OP_WRITE,
+ .__sector = 5,
+ },
+ .cmd.device = dev3,
+ );
+ cmd6 = kmemdup(cmd5, sizeof(*cmd3), GFP_KERNEL);
+ cmd6->rq.__sector = 6;
+ list_add_tail(&cmd3->cmd.eh_entry, &cmd_list);
+ list_add_tail(&cmd1->cmd.eh_entry, &cmd_list);
+ list_add_tail(&cmd2->cmd.eh_entry, &cmd_list);
+ list_add_tail(&cmd5->cmd.eh_entry, &cmd_list);
+ list_add_tail(&cmd6->cmd.eh_entry, &cmd_list);
+ list_add_tail(&cmd4->cmd.eh_entry, &cmd_list);
+
+ KUNIT_EXPECT_EQ(test, list_count_nodes(&cmd_list), 6);
+ kunit_test = test;
+ scsi_call_prepare_resubmit(&host, &cmd_list);
+ kunit_test = NULL;
+ KUNIT_EXPECT_EQ(test, list_count_nodes(&cmd_list), 6);
+ KUNIT_EXPECT_TRUE(test, uld1 < uld2);
+ KUNIT_EXPECT_TRUE(test, uld2 < uld3);
+ KUNIT_EXPECT_PTR_EQ(test, cmd_list.next, &cmd1->cmd.eh_entry);
+ KUNIT_EXPECT_PTR_EQ(test, cmd_list.next->next, &cmd2->cmd.eh_entry);
+ KUNIT_EXPECT_PTR_EQ(test, cmd_list.next->next->next,
+ &cmd3->cmd.eh_entry);
+ KUNIT_EXPECT_PTR_EQ(test, cmd_list.next->next->next->next,
+ &cmd4->cmd.eh_entry);
+ KUNIT_EXPECT_PTR_EQ(test, cmd_list.next->next->next->next->next,
+ &cmd5->cmd.eh_entry);
+ KUNIT_EXPECT_PTR_EQ(test, cmd_list.next->next->next->next->next->next,
+ &cmd6->cmd.eh_entry);
+}
+
+static struct kunit_case prepare_resubmit_test_cases[] = {
+ KUNIT_CASE(test_prepare_resubmit1),
+ KUNIT_CASE(test_prepare_resubmit2),
+ {}
+};
+
+static struct kunit_suite prepare_resubmit_test_suite = {
+ .name = "prepare_resubmit",
+ .test_cases = prepare_resubmit_test_cases,
+};
+kunit_test_suite(prepare_resubmit_test_suite);
+
+MODULE_DESCRIPTION("scsi_call_prepare_resubmit() unit tests");
+MODULE_AUTHOR("Bart Van Assche");
+MODULE_LICENSE("GPL");