On 8/12/23 06:35, Bart Van Assche wrote:
> Make the error handler call .eh_prepare_resubmit() before resubmitting
This reads like the eh_prepare_resubmit callback already exists. But you are
adding it. So you should state that.
> commands. A later patch will use this functionality to sort SCSI
> commands per LBA from inside the SCSI disk driver.
>
> Cc: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
> Cc: Damien Le Moal <dlemoal@xxxxxxxxxx>
> Cc: Christoph Hellwig <hch@xxxxxx>
> Cc: Ming Lei <ming.lei@xxxxxxxxxx>
> Signed-off-by: Bart Van Assche <bvanassche@xxxxxxx>
> ---
> drivers/scsi/Kconfig | 2 +
> drivers/scsi/Kconfig.kunit | 4 ++
> drivers/scsi/Makefile | 2 +
> drivers/scsi/Makefile.kunit | 1 +
> drivers/scsi/scsi_error.c | 43 ++++++++++++++++
> drivers/scsi/scsi_error_test.c | 92 ++++++++++++++++++++++++++++++++++
> drivers/scsi/scsi_priv.h | 1 +
> include/scsi/scsi_driver.h | 1 +
> 8 files changed, 146 insertions(+)
> create mode 100644 drivers/scsi/Kconfig.kunit
> create mode 100644 drivers/scsi/Makefile.kunit
> create mode 100644 drivers/scsi/scsi_error_test.c
>
> diff --git a/drivers/scsi/Kconfig b/drivers/scsi/Kconfig
> index 4962ce989113..fc288f8fb800 100644
> --- a/drivers/scsi/Kconfig
> +++ b/drivers/scsi/Kconfig
> @@ -232,6 +232,8 @@ config SCSI_SCAN_ASYNC
> Note that this setting also affects whether resuming from
> system suspend will be performed asynchronously.
>
> +source "drivers/scsi/Kconfig.kunit"
> +
> menu "SCSI Transports"
> depends on SCSI
>
> diff --git a/drivers/scsi/Kconfig.kunit b/drivers/scsi/Kconfig.kunit
> new file mode 100644
> index 000000000000..68e3d90d49e9
> --- /dev/null
> +++ b/drivers/scsi/Kconfig.kunit
> @@ -0,0 +1,4 @@
> +config SCSI_ERROR_TEST
> + tristate "scsi_error.c unit tests" if !KUNIT_ALL_TESTS
> + depends on SCSI_MOD && KUNIT
> + default KUNIT_ALL_TESTS
> diff --git a/drivers/scsi/Makefile b/drivers/scsi/Makefile
> index f055bfd54a68..1c5c3afb6c6e 100644
> --- a/drivers/scsi/Makefile
> +++ b/drivers/scsi/Makefile
> @@ -168,6 +168,8 @@ scsi_mod-$(CONFIG_PM) += scsi_pm.o
> scsi_mod-$(CONFIG_SCSI_DH) += scsi_dh.o
> scsi_mod-$(CONFIG_BLK_DEV_BSG) += scsi_bsg.o
>
> +include $(srctree)/drivers/scsi/Makefile.kunit
> +
> hv_storvsc-y := storvsc_drv.o
>
> sd_mod-objs := sd.o
> diff --git a/drivers/scsi/Makefile.kunit b/drivers/scsi/Makefile.kunit
> new file mode 100644
> index 000000000000..3e98053b2709
> --- /dev/null
> +++ b/drivers/scsi/Makefile.kunit
> @@ -0,0 +1 @@
> +obj-$(CONFIG_SCSI_ERROR_TEST) += scsi_error_test.o
All the above kunit changes (and the test changes below) seem unrelated to what
the commit message describes. Should these be split into a different patch ?
> diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c
> index c67cdcdc3ba8..0d7835bdc8af 100644
> --- a/drivers/scsi/scsi_error.c
> +++ b/drivers/scsi/scsi_error.c
> @@ -27,6 +27,7 @@
> #include <linux/blkdev.h>
> #include <linux/delay.h>
> #include <linux/jiffies.h>
> +#include <linux/list_sort.h>
>
> #include <scsi/scsi.h>
> #include <scsi/scsi_cmnd.h>
> @@ -2186,6 +2187,46 @@ void scsi_eh_ready_devs(struct Scsi_Host *shost,
> }
> EXPORT_SYMBOL_GPL(scsi_eh_ready_devs);
>
> +/*
> + * Comparison function that allows to sort SCSI commands by ULD driver.
> + */
> +static int scsi_cmp_uld(void *priv, const struct list_head *_a,
> + const struct list_head *_b)
> +{
> + struct scsi_cmnd *a = list_entry(_a, typeof(*a), eh_entry);
> + struct scsi_cmnd *b = list_entry(_b, typeof(*b), eh_entry);
> +
> + /* See also the comment above the list_sort() definition. */
> + return scsi_cmd_to_driver(a) > scsi_cmd_to_driver(b);
> +}
> +
> +void scsi_call_prepare_resubmit(struct list_head *done_q)
> +{
> + struct scsi_cmnd *scmd, *next;
> +
> + /* Sort pending SCSI commands by ULD. */
> + list_sort(NULL, done_q, scsi_cmp_uld);
> +
> + /*
> + * Call .eh_prepare_resubmit for each range of commands with identical
> + * ULD driver pointer.
> + */
> + list_for_each_entry_safe(scmd, next, done_q, eh_entry) {
> + struct scsi_driver *uld = scsi_cmd_to_driver(scmd);
> + struct list_head *prev, uld_cmd_list;
> +
> + while (&next->eh_entry != done_q &&
> + scsi_cmd_to_driver(next) == uld)
> + next = list_next_entry(next, eh_entry);
> + if (!uld->eh_prepare_resubmit)
> + continue;
> + prev = scmd->eh_entry.prev;
> + list_cut_position(&uld_cmd_list, prev, next->eh_entry.prev);
> + uld->eh_prepare_resubmit(&uld_cmd_list);
Is it guaranteed that all uld implement eh_prepare_resubmit ?
> + list_splice(&uld_cmd_list, prev);
> + }
> +}
> +
> /**
> * scsi_eh_flush_done_q - finish processed commands or retry them.
> * @done_q: list_head of processed commands.
> @@ -2194,6 +2235,8 @@ void scsi_eh_flush_done_q(struct list_head *done_q)
> {
> struct scsi_cmnd *scmd, *next;
>
> + scsi_call_prepare_resubmit(done_q);
> +
> list_for_each_entry_safe(scmd, next, done_q, eh_entry) {
> list_del_init(&scmd->eh_entry);
> if (scsi_device_online(scmd->device) &&
> diff --git a/drivers/scsi/scsi_error_test.c b/drivers/scsi/scsi_error_test.c
> new file mode 100644
> index 000000000000..fd616527f726
> --- /dev/null
> +++ b/drivers/scsi/scsi_error_test.c
> @@ -0,0 +1,92 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright 2023 Google LLC
> + */
> +#include <kunit/test.h>
> +#include <scsi/scsi_cmnd.h>
> +#include <scsi/scsi_driver.h>
> +#include "scsi_priv.h"
> +
> +static struct kunit *kunit_test;
> +
> +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_resubmit(struct kunit *test)
> +{
> + static struct scsi_cmnd cmd1, cmd2, cmd3, cmd4, cmd5, cmd6;
> + static struct scsi_device dev1, dev2, dev3;
> + struct scsi_driver *uld;
> + LIST_HEAD(cmd_list);
> +
> + 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];
> + dev1.sdev_gendev.driver = &uld1->gendrv;
> + dev2.sdev_gendev.driver = &uld2->gendrv;
> + dev3.sdev_gendev.driver = &uld3->gendrv;
> + cmd1.device = &dev1;
> + cmd2.device = &dev1;
> + cmd3.device = &dev2;
> + cmd4.device = &dev2;
> + cmd5.device = &dev3;
> + cmd6.device = &dev3;
> + list_add_tail(&cmd1.eh_entry, &cmd_list);
> + list_add_tail(&cmd3.eh_entry, &cmd_list);
> + list_add_tail(&cmd5.eh_entry, &cmd_list);
> + list_add_tail(&cmd2.eh_entry, &cmd_list);
> + list_add_tail(&cmd4.eh_entry, &cmd_list);
> + list_add_tail(&cmd6.eh_entry, &cmd_list);
> +
> + KUNIT_EXPECT_EQ(test, list_count_nodes(&cmd_list), 6);
> + kunit_test = test;
> + scsi_call_prepare_resubmit(&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.eh_entry);
> + KUNIT_EXPECT_PTR_EQ(test, cmd_list.next->next, &cmd2.eh_entry);
> + KUNIT_EXPECT_PTR_EQ(test, cmd_list.next->next->next, &cmd3.eh_entry);
> + KUNIT_EXPECT_PTR_EQ(test, cmd_list.next->next->next->next,
> + &cmd4.eh_entry);
> + KUNIT_EXPECT_PTR_EQ(test, cmd_list.next->next->next->next->next,
> + &cmd5.eh_entry);
> + KUNIT_EXPECT_PTR_EQ(test, cmd_list.next->next->next->next->next->next,
> + &cmd6.eh_entry);
> + kfree(uld);
> +}
> +
> +static struct kunit_case prepare_resubmit_test_cases[] = {
> + KUNIT_CASE(test_prepare_resubmit),
> + {}
> +};
> +
> +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_AUTHOR("Bart Van Assche");
> +MODULE_LICENSE("GPL");
> diff --git a/drivers/scsi/scsi_priv.h b/drivers/scsi/scsi_priv.h
> index f42388ecb024..df4af4645430 100644
> --- a/drivers/scsi/scsi_priv.h
> +++ b/drivers/scsi/scsi_priv.h
> @@ -101,6 +101,7 @@ int scsi_eh_get_sense(struct list_head *work_q,
> struct list_head *done_q);
> bool scsi_noretry_cmd(struct scsi_cmnd *scmd);
> void scsi_eh_done(struct scsi_cmnd *scmd);
> +void scsi_call_prepare_resubmit(struct list_head *done_q);
>
> /* scsi_lib.c */
> extern int scsi_maybe_unblock_host(struct scsi_device *sdev);
> diff --git a/include/scsi/scsi_driver.h b/include/scsi/scsi_driver.h
> index 4ce1988b2ba0..2b11be896eee 100644
> --- a/include/scsi/scsi_driver.h
> +++ b/include/scsi/scsi_driver.h
> @@ -18,6 +18,7 @@ struct scsi_driver {
> int (*done)(struct scsi_cmnd *);
> int (*eh_action)(struct scsi_cmnd *, int);
> void (*eh_reset)(struct scsi_cmnd *);
> + void (*eh_prepare_resubmit)(struct list_head *cmd_list);
> };
> #define to_scsi_driver(drv) \
> container_of((drv), struct scsi_driver, gendrv)
--
Damien Le Moal
Western Digital Research
