Re: [PATCH v5 1/3] block: Add test-iosched scheduler

merez
2012-07-31T14:36:59Z

Hi Jens,

Do you have comments on this patch?
Can we push it to kernel 3.6 version?

Thanks,
Maya
On Tue, July 31, 2012 7:25 am, Maya Erez wrote:
> The test scheduler allows testing a block device by dispatching
> specific requests according to the test case and declare PASS/FAIL
> according to the requests completion error code
>
> Signed-off-by: Maya Erez <merez@codeaurora.org>
> ---
> Documentation/block/test-iosched.txt | 39 ++
> block/Kconfig.iosched | 11 +
> block/Makefile | 1 +
> block/blk-core.c | 3 +-
> block/test-iosched.c | 1038
> ++++++++++++++++++++++++++++++++++
> include/linux/test-iosched.h | 233 ++++++++
> 6 files changed, 1323 insertions(+), 2 deletions(-)
> create mode 100644 Documentation/block/test-iosched.txt
> create mode 100644 block/test-iosched.c
> create mode 100644 include/linux/test-iosched.h
>
> diff --git a/Documentation/block/test-iosched.txt
> b/Documentation/block/test-iosched.txt
> new file mode 100644
> index 0000000..75d8134
> --- /dev/null
> +++ b/Documentation/block/test-iosched.txt
> @@ -0,0 +1,39 @@
> +Test IO scheduler
> +==================
> +
> +The test scheduler allows testing a block device by dispatching
> +specific requests according to the test case and declare PASS/FAIL
> +according to the requests completion error code.
> +
> +The test IO scheduler implements the no-op scheduler operations, and uses
> +them in order to dispatch the non-test requests when no test is running.
> +This will allow to keep a normal FS operation in parallel to the test
> +capability.
> +The test IO scheduler keeps two different queues, one for real-world
> requests
> +(inserted by the FS) and the other for the test requests.
> +The test IO scheduler chooses the queue for dispatch requests according
> to the
> +test state (IDLE/RUNNING).
> +
> +the test IO scheduler is compiled by default as a dynamic module and
> enabled
> +only if CONFIG_DEBUG_FS is defined.
> +
> +Each block device test utility that would like to use the test-iosched
> test
> +services, should register as a blk_dev_test_type and supply an init and
> exit
> +callbacks. Those callback are called upon selection (or removal) of the
> +test-iosched as the active scheduler. From that point the block device
> test
> +can start a test and supply its own callbacks for preparing, running,
> result
> +checking and cleanup of the test.
> +
> +Each test is exposed via debugfs and can be triggered by writing to
> +the debugfs file. In order to add a new test one should expose a new
> debugfs
> +file for the new test.
> +
> +Selecting IO schedulers
> +-----------------------
> +Refer to Documentation/block/switching-sched.txt for information on
> +selecting an io scheduler on a per-device basis.
> +
> +
> +May 10 2012, maya Erez <merez@codeaurora.org>
> +
> +
> diff --git a/block/Kconfig.iosched b/block/Kconfig.iosched
> index 421bef9..af3d6a3 100644
> --- a/block/Kconfig.iosched
> +++ b/block/Kconfig.iosched
> @@ -12,6 +12,17 @@ config IOSCHED_NOOP
> that do their own scheduling and require only minimal assistance from
> the kernel.
>
> +config IOSCHED_TEST
> + tristate "Test I/O scheduler"
> + depends on DEBUG_FS
> + default m
> + ---help---
> + The test I/O scheduler is a duplicate of the noop scheduler with
> + addition of test utlity.
> + It allows testing a block device by dispatching specific requests
> + according to the test case and declare PASS/FAIL according to the
> + requests completion error code.
> +
> config IOSCHED_DEADLINE
> tristate "Deadline I/O scheduler"
> default y
> diff --git a/block/Makefile b/block/Makefile
> index 39b76ba..436b220 100644
> --- a/block/Makefile
> +++ b/block/Makefile
> @@ -15,6 +15,7 @@ obj-$(CONFIG_BLK_DEV_THROTTLING) += blk-throttle.o
> obj-$(CONFIG_IOSCHED_NOOP) += noop-iosched.o
> obj-$(CONFIG_IOSCHED_DEADLINE) += deadline-iosched.o
> obj-$(CONFIG_IOSCHED_CFQ) += cfq-iosched.o
> +obj-$(CONFIG_IOSCHED_TEST) += test-iosched.o
>
> obj-$(CONFIG_BLOCK_COMPAT) += compat_ioctl.o
> obj-$(CONFIG_BLK_DEV_INTEGRITY) += blk-integrity.o
> diff --git a/block/blk-core.c b/block/blk-core.c
> index c3b17c3..6fe111e 100644
> --- a/block/blk-core.c
> +++ b/block/blk-core.c
> @@ -1085,8 +1085,6 @@ struct request *blk_get_request(struct request_queue
> *q, int rw, gfp_t gfp_mask)
> {
> struct request *rq;
>
> - BUG_ON(rw != READ && rw != WRITE);
> -
> spin_lock_irq(q->queue_lock);
> if (gfp_mask & __GFP_WAIT)
> rq = get_request_wait(q, rw, NULL);
> @@ -1419,6 +1417,7 @@ void init_request_from_bio(struct request *req,
> struct bio *bio)
> req->ioprio = bio_prio(bio);
> blk_rq_bio_prep(req->q, req, bio);
> }
> +EXPORT_SYMBOL(init_request_from_bio);
>
> void blk_queue_bio(struct request_queue *q, struct bio *bio)
> {
> diff --git a/block/test-iosched.c b/block/test-iosched.c
> new file mode 100644
> index 0000000..d3d10d3
> --- /dev/null
> +++ b/block/test-iosched.c
> @@ -0,0 +1,1038 @@
> +/* Copyright (c) 2012, Code Aurora Forum. All rights reserved.
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 and
> + * only version 2 as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + *
> + * The test scheduler allows to test the block device by dispatching
> + * specific requests according to the test case and declare PASS/FAIL
> + * according to the requests completion error code.
> + * Each test is exposed via debugfs and can be triggered by writing to
> + * the debugfs file.
> + *
> + */
> +
> +/* elevator test iosched */
> +#include <linux/blkdev.h>
> +#include <linux/elevator.h>
> +#include <linux/bio.h>
> +#include <linux/module.h>
> +#include <linux/slab.h>
> +#include <linux/init.h>
> +#include <linux/debugfs.h>
> +#include <linux/test-iosched.h>
> +#include <linux/delay.h>
> +#include "blk.h"
> +
> +#define MODULE_NAME "test-iosched"
> +#define WR_RD_START_REQ_ID 1234
> +#define UNIQUE_START_REQ_ID 5678
> +#define TIMEOUT_TIMER_MS 40000
> +#define TEST_MAX_TESTCASE_ROUNDS 15
> +
> +#define test_pr_debug(fmt, args...) pr_debug("%s: "fmt"\n", MODULE_NAME,
> args)
> +#define test_pr_info(fmt, args...) pr_info("%s: "fmt"\n", MODULE_NAME,
> args)
> +#define test_pr_err(fmt, args...) pr_err("%s: "fmt"\n", MODULE_NAME,
> args)
> +
> +static DEFINE_SPINLOCK(blk_dev_test_list_lock);
> +static LIST_HEAD(blk_dev_test_list);
> +static struct test_data *ptd;
> +
> +/* Get the request after `test_rq' in the test requests list */
> +static struct test_request *
> +latter_test_request(struct request_queue *q,
> + struct test_request *test_rq)
> +{
> + struct test_data *td = q->elevator->elevator_data;
> +
> + if (test_rq->queuelist.next == &td->test_queue)
> + return NULL;
> + return list_entry(test_rq->queuelist.next, struct test_request,
> + queuelist);
> +}
> +
> +/**
> + * test_iosched_get_req_queue() - returns the request queue
> + * served by the scheduler
> + */
> +struct request_queue *test_iosched_get_req_queue(void)
> +{
> + if (!ptd)
> + return NULL;
> +
> + return ptd->req_q;
> +}
> +EXPORT_SYMBOL(test_iosched_get_req_queue);
> +
> +/**
> + * test_iosched_mark_test_completion() - Wakeup the debugfs
> + * thread, waiting on the test completion
> + */
> +void test_iosched_mark_test_completion(void)
> +{
> + if (!ptd)
> + return;
> +
> + ptd->test_state = TEST_COMPLETED;
> + wake_up(&ptd->wait_q);
> +}
> +EXPORT_SYMBOL(test_iosched_mark_test_completion);
> +
> +/* Check if all the queued test requests were completed */
> +static void check_test_completion(void)
> +{
> + struct test_request *test_rq;
> + struct request *rq;
> +
> + list_for_each_entry(test_rq, &ptd->test_queue, queuelist) {
> + rq = test_rq->rq;
> + if (!test_rq->req_completed)
> + return;
> + }
> +
> + test_pr_info("%s: Test is completed", __func__);
> +
> + test_iosched_mark_test_completion();
> +}
> +
> +/*
> + * A callback to be called per bio completion.
> + * Frees the bio memory.
> + */
> +static void end_test_bio(struct bio *bio, int err)
> +{
> + if (err)
> + clear_bit(BIO_UPTODATE, &bio->bi_flags);
> +
> + bio_put(bio);
> +}
> +
> +/*
> + * A callback to be called per request completion.
> + * the request memory is not freed here, will be freed later after the
> test
> + * results checking.
> + */
> +static void end_test_req(struct request *rq, int err)
> +{
> + struct test_request *test_rq;
> +
> + test_rq = (struct test_request *)rq->elv.priv[0];
> + BUG_ON(!test_rq);
> +
> + test_pr_info("%s: request %d completed, err=%d",
> + __func__, test_rq->req_id, err);
> +
> + test_rq->req_completed = true;
> + test_rq->req_result = err;
> +
> + check_test_completion();
> +}
> +
> +/**
> + * test_iosched_add_unique_test_req() - Create and queue a non
> + * read/write request (such as FLUSH/DISCRAD/SANITIZE).
> + * @is_err_expcted: A flag to indicate if this request
> + * should succeed or not
> + * @req_unique: The type of request to add
> + * @start_sec: start address of the first bio
> + * @nr_sects: number of sectors in the request
> + * @end_req_io: specific completion callback. When not
> + * set, the defaulcallback will be used
> + */
> +int test_iosched_add_unique_test_req(int is_err_expcted,
> + enum req_unique_type req_unique,
> + int start_sec, int nr_sects, rq_end_io_fn *end_req_io)
> +{
> + struct bio *bio;
> + struct request *rq;
> + int rw_flags;
> + struct test_request *test_rq;
> +
> + if (!ptd)
> + return -ENODEV;
> +
> + bio = bio_alloc(GFP_KERNEL, 0);
> + if (!bio) {
> + test_pr_err("%s: Failed to allocate a bio", __func__);
> + return -ENODEV;
> + }
> + bio_get(bio);
> + bio->bi_end_io = end_test_bio;
> +
> + switch (req_unique) {
> + case REQ_UNIQUE_FLUSH:
> + bio->bi_rw = WRITE_FLUSH;
> + break;
> + case REQ_UNIQUE_DISCARD:
> + bio->bi_rw = REQ_WRITE | REQ_DISCARD;
> + bio->bi_size = nr_sects << 9;
> + bio->bi_sector = start_sec;
> + break;
> + default:
> + test_pr_err("%s: Invalid request type %d", __func__,
> + req_unique);
> + bio_put(bio);
> + return -ENODEV;
> + }
> +
> + rw_flags = bio_data_dir(bio);
> + if (bio->bi_rw & REQ_SYNC)
> + rw_flags |= REQ_SYNC;
> +
> + rq = blk_get_request(ptd->req_q, rw_flags, GFP_KERNEL);
> + if (!rq) {
> + test_pr_err("%s: Failed to allocate a request", __func__);
> + bio_put(bio);
> + return -ENODEV;
> + }
> +
> + init_request_from_bio(rq, bio);
> + if (end_req_io)
> + rq->end_io = end_req_io;
> + else
> + rq->end_io = end_test_req;
> +
> + test_rq = kzalloc(sizeof(struct test_request), GFP_KERNEL);
> + if (!test_rq) {
> + test_pr_err("%s: Failed to allocate a test request", __func__);
> + bio_put(bio);
> + blk_put_request(rq);
> + return -ENODEV;
> + }
> + test_rq->req_completed = false;
> + test_rq->req_result = -EINVAL;
> + test_rq->rq = rq;
> + test_rq->is_err_expected = is_err_expcted;
> + rq->elv.priv[0] = (void *)test_rq;
> + test_rq->req_id = ptd->unique_next_req_id++;
> +
> + test_pr_debug(
> + "%s: added request %d to the test requests list, type = %d",
> + __func__, test_rq->req_id, req_unique);
> +
> + list_add_tail(&test_rq->queuelist, &ptd->test_queue);
> +
> + return 0;
> +}
> +EXPORT_SYMBOL(test_iosched_add_unique_test_req);
> +
> +/*
> + * Get a pattern to be filled in the request data buffer.
> + * If the pattern used is (-1) the buffer will be filled with sequential
> + * numbers
> + */
> +static void fill_buf_with_pattern(int *buf, int num_bytes, int pattern)
> +{
> + int i = 0;
> + int num_of_dwords = num_bytes/sizeof(int);
> +
> + if (pattern == TEST_NO_PATTERN)
> + return;
> +
> + /* num_bytes should be aligned to sizeof(int) */
> + BUG_ON((num_bytes % sizeof(int)) != 0);
> +
> + if (pattern == TEST_PATTERN_SEQUENTIAL) {
> + for (i = 0; i < num_of_dwords; i++)
> + buf[i] = i;
> + } else {
> + for (i = 0; i < num_of_dwords; i++)
> + buf[i] = pattern;
> + }
> +}
> +
> +/**
> + * test_iosched_add_wr_rd_test_req() - Create and queue a
> + * read/write request.
> + * @is_err_expcted: A flag to indicate if this request
> + * should succeed or not
> + * @direction: READ/WRITE
> + * @start_sec: start address of the first bio
> + * @num_bios: number of BIOs to be allocated for the
> + * request
> + * @pattern: A pattern, to be written into the write
> + * requests data buffer. In case of READ
> + * request, the given pattern is kept as
> + * the expected pattern. The expected
> + * pattern will be compared in the test
> + * check result function. If no comparisson
> + * is required, set pattern to
> + * TEST_NO_PATTERN.
> + * @end_req_io: specific completion callback. When not
> + * set,the default callback will be used
> + *
> + * This function allocates the test request and the block
> + * request and calls blk_rq_map_kern which allocates the
> + * required BIO. The allocated test request and the block
> + * request memory is freed at the end of the test and the
> + * allocated BIO memory is freed by end_test_bio.
> + */
> +int test_iosched_add_wr_rd_test_req(int is_err_expcted,
> + int direction, int start_sec,
> + int num_bios, int pattern, rq_end_io_fn *end_req_io)
> +{
> + struct request *rq = NULL;
> + struct test_request *test_rq = NULL;
> + int rw_flags = 0;
> + int buf_size = 0;
> + int ret = 0, i = 0;
> + unsigned int *bio_ptr = NULL;
> + struct bio *bio = NULL;
> +
> + if (!ptd)
> + return -ENODEV;
> +
> + rw_flags = direction;
> +
> + rq = blk_get_request(ptd->req_q, rw_flags, GFP_KERNEL);
> + if (!rq) {
> + test_pr_err("%s: Failed to allocate a request", __func__);
> + return -ENODEV;
> + }
> +
> + test_rq = kzalloc(sizeof(struct test_request), GFP_KERNEL);
> + if (!test_rq) {
> + test_pr_err("%s: Failed to allocate test request", __func__);
> + blk_put_request(rq);
> + return -ENODEV;
> + }
> +
> + buf_size = sizeof(unsigned int) * BIO_U32_SIZE * num_bios;
> + test_rq->bios_buffer = kzalloc(buf_size, GFP_KERNEL);
> + if (!test_rq->bios_buffer) {
> + test_pr_err("%s: Failed to allocate the data buf", __func__);
> + goto err;
> + }
> + test_rq->buf_size = buf_size;
> +
> + if (direction == WRITE)
> + fill_buf_with_pattern(test_rq->bios_buffer,
> + buf_size, pattern);
> + test_rq->wr_rd_data_pattern = pattern;
> +
> + bio_ptr = test_rq->bios_buffer;
> + for (i = 0; i < num_bios; ++i) {
> + ret = blk_rq_map_kern(ptd->req_q, rq,
> + (void *)bio_ptr,
> + sizeof(unsigned int)*BIO_U32_SIZE,
> + GFP_KERNEL);
> + if (ret) {
> + test_pr_err("%s: blk_rq_map_kern returned error %d",
> + __func__, ret);
> + goto err;
> + }
> + bio_ptr += BIO_U32_SIZE;
> + }
> +
> + if (end_req_io)
> + rq->end_io = end_req_io;
> + else
> + rq->end_io = end_test_req;
> + rq->__sector = start_sec;
> + rq->cmd_type |= REQ_TYPE_FS;
> +
> + if (rq->bio) {
> + rq->bio->bi_sector = start_sec;
> + rq->bio->bi_end_io = end_test_bio;
> + bio = rq->bio;
> + while ((bio = bio->bi_next) != NULL)
> + bio->bi_end_io = end_test_bio;
> + }
> +
> + ptd->num_of_write_bios += num_bios;
> + test_rq->req_id = ptd->wr_rd_next_req_id++;
> +
> + test_rq->req_completed = false;
> + test_rq->req_result = -EINVAL;
> + test_rq->rq = rq;
> + test_rq->is_err_expected = is_err_expcted;
> + rq->elv.priv[0] = (void *)test_rq;
> +
> + test_pr_debug(
> + "%s: added request %d to the test requests list, buf_size=%d",
> + __func__, test_rq->req_id, buf_size);
> +
> + list_add_tail(&test_rq->queuelist, &ptd->test_queue);
> +
> + return 0;
> +err:
> + blk_put_request(rq);
> + kfree(test_rq->bios_buffer);
> + return -ENODEV;
> +}
> +EXPORT_SYMBOL(test_iosched_add_wr_rd_test_req);
> +
> +/* Converts the testcase number into a string */
> +static char *get_test_case_str(struct test_data *td)
> +{
> + if (td->test_info.get_test_case_str_fn)
> + return td->test_info.get_test_case_str_fn(td);
> +
> + return "Unknown testcase";
> +}
> +
> +/*
> + * Verify that the test request data buffer includes the expected
> + * pattern
> + */
> +static int compare_buffer_to_pattern(struct test_request *test_rq)
> +{
> + int i = 0;
> + int num_of_dwords = test_rq->buf_size/sizeof(int);
> +
> + /* num_bytes should be aligned to sizeof(int) */
> + BUG_ON((test_rq->buf_size % sizeof(int)) != 0);
> + BUG_ON(test_rq->bios_buffer == NULL);
> +
> + if (test_rq->wr_rd_data_pattern == TEST_NO_PATTERN)
> + return 0;
> +
> + if (test_rq->wr_rd_data_pattern == TEST_PATTERN_SEQUENTIAL) {
> + for (i = 0; i < num_of_dwords; i++) {
> + if (test_rq->bios_buffer[i] != i) {
> + test_pr_err(
> + "%s: wrong pattern 0x%x in index %d",
> + __func__, test_rq->bios_buffer[i], i);
> + return -EINVAL;
> + }
> + }
> + } else {
> + for (i = 0; i < num_of_dwords; i++) {
> + if (test_rq->bios_buffer[i] !=
> + test_rq->wr_rd_data_pattern) {
> + test_pr_err(
> + "%s: wrong pattern 0x%x in index %d",
> + __func__, test_rq->bios_buffer[i], i);
> + return -EINVAL;
> + }
> + }
> + }
> +
> + return 0;
> +}
> +
> +/*
> + * Determine if the test passed or failed.
> + * The function checks the test request completion value and calls
> + * check_testcase_result for result checking that are specific
> + * to a test case.
> + */
> +static int check_test_result(struct test_data *td)
> +{
> + struct test_request *test_rq;
> + struct request *rq;
> + int res = 0;
> + static int run;
> +
> + list_for_each_entry(test_rq, &ptd->test_queue, queuelist) {
> + rq = test_rq->rq;
> + if (!test_rq->req_completed) {
> + test_pr_err("%s: rq %d not completed", __func__,
> + test_rq->req_id);
> + res = -EINVAL;
> + goto err;
> + }
> +
> + if ((test_rq->req_result < 0) && !test_rq->is_err_expected) {
> + test_pr_err(
> + "%s: rq %d completed with err, not as expected",
> + __func__, test_rq->req_id);
> + res = -EINVAL;
> + goto err;
> + }
> + if ((test_rq->req_result == 0) && test_rq->is_err_expected) {
> + test_pr_err("%s: rq %d succeeded, not as expected",
> + __func__, test_rq->req_id);
> + res = -EINVAL;
> + goto err;
> + }
> + if (rq_data_dir(test_rq->rq) == READ) {
> + res = compare_buffer_to_pattern(test_rq);
> + if (res) {
> + test_pr_err("%s: read pattern not as expected",
> + __func__);
> + res = -EINVAL;
> + goto err;
> + }
> + }
> + }
> +
> + if (td->test_info.check_test_result_fn) {
> + res = td->test_info.check_test_result_fn(td);
> + if (res)
> + goto err;
> + }
> +
> + test_pr_info("%s: %s, run# %03d, PASSED",
> + __func__, get_test_case_str(td), ++run);
> + td->test_result = TEST_PASSED;
> +
> + return 0;
> +err:
> + test_pr_err("%s: %s, run# %03d, FAILED",
> + __func__, get_test_case_str(td), ++run);
> + td->test_result = TEST_FAILED;
> + return res;
> +}
> +
> +/* Create and queue the required requests according to the test case */
> +static int prepare_test(struct test_data *td)
> +{
> + int ret = 0;
> +
> + if (td->test_info.prepare_test_fn) {
> + ret = td->test_info.prepare_test_fn(td);
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> +/* Run the test */
> +static int run_test(struct test_data *td)
> +{
> + int ret = 0;
> +
> + if (td->test_info.run_test_fn) {
> + ret = td->test_info.run_test_fn(td);
> + return ret;
> + }
> +
> + /*
> + * Set the next_req pointer to the first request in the test requests
> + * list
> + */
> + if (!list_empty(&td->test_queue))
> + td->next_req = list_entry(td->test_queue.next,
> + struct test_request, queuelist);
> + __blk_run_queue(td->req_q);
> +
> + return 0;
> +}
> +
> +/* Free the allocated test requests, their requests and BIOs buffer */
> +static void free_test_requests(struct test_data *td)
> +{
> + struct test_request *test_rq;
> + struct bio *bio;
> +
> + while (!list_empty(&td->test_queue)) {
> + test_rq = list_entry(td->test_queue.next, struct test_request,
> + queuelist);
> + list_del_init(&test_rq->queuelist);
> + /*
> + * If the request was not completed we need to free its BIOs
> + * and remove it from the packed list
> + */
> + if (!test_rq->req_completed) {
> + test_pr_info(
> + "%s: Freeing memory of an uncompleted request",
> + __func__);
> + list_del_init(&test_rq->rq->queuelist);
> + while ((bio = test_rq->rq->bio) != NULL) {
> + test_rq->rq->bio = bio->bi_next;
> + bio_put(bio);
> + }
> + }
> + blk_put_request(test_rq->rq);
> + kfree(test_rq->bios_buffer);
> + kfree(test_rq);
> + }
> +}
> +
> +/*
> + * Do post test operations.
> + * Free the allocated test requests, their requests and BIOs buffer.
> + */
> +static int post_test(struct test_data *td)
> +{
> + int ret = 0;
> +
> + if (td->test_info.post_test_fn)
> + ret = td->test_info.post_test_fn(td);
> +
> + ptd->next_req = NULL;
> +
> + free_test_requests(td);
> +
> + ptd->test_info.testcase = 0;
> + ptd->test_state = TEST_IDLE;
> +
> + return ret;
> +}
> +
> +/*
> + * The timer verifies that the test will be completed even if we don't
> get
> + * the completion callback for all the requests.
> + */
> +static void test_timeout_handler(unsigned long data)
> +{
> + struct test_data *td = (struct test_data *)data;
> +
> + test_pr_info("%s: TIMEOUT timer expired", __func__);
> + td->test_state = TEST_COMPLETED;
> + wake_up(&td->wait_q);
> + return;
> +}
> +
> +static unsigned int get_timeout_msec(struct test_data *td)
> +{
> + if (td->test_info.timeout_msec)
> + return td->test_info.timeout_msec;
> + else
> + return TIMEOUT_TIMER_MS;
> +}
> +
> +/**
> + * test_iosched_start_test() - Prepares and runs the test.
> + * @t_info: the current test testcase and callbacks
> + * functions
> + *
> + * The function also checks the test result upon test completion
> + */
> +int test_iosched_start_test(struct test_info *t_info)
> +{
> + int ret = 0;
> + unsigned timeout_msec;
> + int counter = 0;
> + char *test_name = NULL;
> +
> + if (!ptd)
> + return -ENODEV;
> +
> + if (!t_info) {
> + ptd->test_result = TEST_FAILED;
> + return -EINVAL;
> + }
> +
> + do {
> + if (ptd->ignore_round)
> + /*
> + * We ignored the last run due to FS write requests.
> + * Sleep to allow those requests to be issued
> + */
> + msleep(2000);
> +
> + spin_lock(&ptd->lock);
> +
> + if (ptd->test_state != TEST_IDLE) {
> + test_pr_info(
> + "%s: Another test is running, try again later",
> + __func__);
> + spin_unlock(&ptd->lock);
> + return -EBUSY;
> + }
> +
> + if (ptd->start_sector == 0) {
> + test_pr_err("%s: Invalid start sector", __func__);
> + ptd->test_result = TEST_FAILED;
> + spin_unlock(&ptd->lock);
> + return -EINVAL;
> + }
> +
> + memcpy(&ptd->test_info, t_info, sizeof(struct test_info));
> +
> + ptd->next_req = NULL;
> + ptd->test_result = TEST_NO_RESULT;
> + ptd->num_of_write_bios = 0;
> +
> + ptd->unique_next_req_id = UNIQUE_START_REQ_ID;
> + ptd->wr_rd_next_req_id = WR_RD_START_REQ_ID;
> +
> + ptd->ignore_round = false;
> + ptd->fs_wr_reqs_during_test = false;
> +
> + ptd->test_state = TEST_RUNNING;
> +
> + spin_unlock(&ptd->lock);
> +
> + timeout_msec = get_timeout_msec(ptd);
> + mod_timer(&ptd->timeout_timer, jiffies +
> + msecs_to_jiffies(timeout_msec));
> +
> + if (ptd->test_info.get_test_case_str_fn)
> + test_name = ptd->test_info.get_test_case_str_fn(ptd);
> + else
> + test_name = "Unknown testcase";
> + test_pr_info("%s: Starting test %s\n", __func__, test_name);
> +
> + ret = prepare_test(ptd);
> + if (ret) {
> + test_pr_err("%s: failed to prepare the test\n",
> + __func__);
> + goto error;
> + }
> +
> + ret = run_test(ptd);
> + if (ret) {
> + test_pr_err("%s: failed to run the test\n", __func__);
> + goto error;
> + }
> +
> + test_pr_info("%s: Waiting for the test completion", __func__);
> +
> + wait_event(ptd->wait_q, ptd->test_state == TEST_COMPLETED);
> + del_timer_sync(&ptd->timeout_timer);
> +
> + ret = check_test_result(ptd);
> + if (ret) {
> + test_pr_err("%s: check_test_result failed\n",
> + __func__);
> + goto error;
> + }
> +
> + ret = post_test(ptd);
> + if (ret) {
> + test_pr_err("%s: post_test failed\n", __func__);
> + goto error;
> + }
> +
> + /*
> + * Wakeup the queue thread to fetch FS requests that might got
> + * postponded due to the test
> + */
> + __blk_run_queue(ptd->req_q);
> +
> + if (ptd->ignore_round)
> + test_pr_info(
> + "%s: Round canceled (Got wr reqs in the middle)",
> + __func__);
> +
> + if (++counter == TEST_MAX_TESTCASE_ROUNDS) {
> + test_pr_info("%s: Too many rounds, did not succeed...",
> + __func__);
> + ptd->test_result = TEST_FAILED;
> + }
> +
> + } while ((ptd->ignore_round) && (counter < TEST_MAX_TESTCASE_ROUNDS));
> +
> + if (ptd->test_result == TEST_PASSED)
> + return 0;
> + else
> + return -EINVAL;
> +
> +error:
> + post_test(ptd);
> + ptd->test_result = TEST_FAILED;
> + return ret;
> +}
> +EXPORT_SYMBOL(test_iosched_start_test);
> +
> +/**
> + * test_iosched_register() - register a block device test
> + * utility.
> + * @bdt: the block device test type to register
> + */
> +void test_iosched_register(struct blk_dev_test_type *bdt)
> +{
> + spin_lock(&blk_dev_test_list_lock);
> + list_add_tail(&bdt->list, &blk_dev_test_list);
> + spin_unlock(&blk_dev_test_list_lock);
> +}
> +EXPORT_SYMBOL_GPL(test_iosched_register);
> +
> +/**
> + * test_iosched_unregister() - unregister a block device test
> + * utility.
> + * @bdt: the block device test type to unregister
> + */
> +void test_iosched_unregister(struct blk_dev_test_type *bdt)
> +{
> + spin_lock(&blk_dev_test_list_lock);
> + list_del_init(&bdt->list);
> + spin_unlock(&blk_dev_test_list_lock);
> +}
> +EXPORT_SYMBOL_GPL(test_iosched_unregister);
> +
> +/**
> + * test_iosched_set_test_result() - Set the test
> + * result(PASS/FAIL)
> + * @test_result: the test result
> + */
> +void test_iosched_set_test_result(int test_result)
> +{
> + if (!ptd)
> + return;
> +
> + ptd->test_result = test_result;
> +}
> +EXPORT_SYMBOL(test_iosched_set_test_result);
> +
> +
> +/**
> + * test_iosched_set_ignore_round() - Set the ignore_round flag
> + * @ignore_round: A flag to indicate if this test round
> + * should be ignored and re-run
> + */
> +void test_iosched_set_ignore_round(bool ignore_round)
> +{
> + if (!ptd)
> + return;
> +
> + ptd->ignore_round = ignore_round;
> +}
> +EXPORT_SYMBOL(test_iosched_set_ignore_round);
> +
> +/**
> + * test_iosched_get_debugfs_tests_root() - returns the root
> + * debugfs directory for the test_iosched tests
> + */
> +struct dentry *test_iosched_get_debugfs_tests_root(void)
> +{
> + if (!ptd)
> + return NULL;
> +
> + return ptd->debug.debug_tests_root;
> +}
> +EXPORT_SYMBOL(test_iosched_get_debugfs_tests_root);
> +
> +/**
> + * test_iosched_get_debugfs_utils_root() - returns the root
> + * debugfs directory for the test_iosched utils
> + */
> +struct dentry *test_iosched_get_debugfs_utils_root(void)
> +{
> + if (!ptd)
> + return NULL;
> +
> + return ptd->debug.debug_utils_root;
> +}
> +EXPORT_SYMBOL(test_iosched_get_debugfs_utils_root);
> +
> +static int test_debugfs_init(struct test_data *td)
> +{
> + td->debug.debug_root = debugfs_create_dir("test-iosched", NULL);
> + if (!td->debug.debug_root)
> + return -ENOENT;
> +
> + td->debug.debug_tests_root = debugfs_create_dir("tests",
> + td->debug.debug_root);
> + if (!td->debug.debug_tests_root)
> + goto err;
> +
> + td->debug.debug_utils_root = debugfs_create_dir("utils",
> + td->debug.debug_root);
> + if (!td->debug.debug_utils_root)
> + goto err;
> +
> + td->debug.debug_test_result = debugfs_create_u32(
> + "test_result",
> + S_IRUGO | S_IWUGO,
> + td->debug.debug_utils_root,
> + &td->test_result);
> + if (!td->debug.debug_test_result)
> + goto err;
> +
> + td->debug.start_sector = debugfs_create_u32(
> + "start_sector",
> + S_IRUGO | S_IWUGO,
> + td->debug.debug_utils_root,
> + &td->start_sector);
> + if (!td->debug.start_sector)
> + goto err;
> +
> + return 0;
> +
> +err:
> + debugfs_remove_recursive(td->debug.debug_root);
> + return -ENOENT;
> +}
> +
> +static void test_debugfs_cleanup(struct test_data *td)
> +{
> + debugfs_remove_recursive(td->debug.debug_root);
> +}
> +
> +static void print_req(struct request *req)
> +{
> + struct bio *bio;
> + struct test_request *test_rq;
> +
> + if (!req)
> + return;
> +
> + test_rq = (struct test_request *)req->elv.priv[0];
> +
> + if (test_rq) {
> + test_pr_debug("%s: Dispatch request %d: __sector=0x%lx",
> + __func__, test_rq->req_id, (unsigned long)req->__sector);
> + test_pr_debug("%s: nr_phys_segments=%d, num_of_sectors=%d",
> + __func__, req->nr_phys_segments, blk_rq_sectors(req));
> + bio = req->bio;
> + test_pr_debug("%s: bio: bi_size=%d, bi_sector=0x%lx",
> + __func__, bio->bi_size,
> + (unsigned long)bio->bi_sector);
> + while ((bio = bio->bi_next) != NULL) {
> + test_pr_debug("%s: bio: bi_size=%d, bi_sector=0x%lx",
> + __func__, bio->bi_size,
> + (unsigned long)bio->bi_sector);
> + }
> + }
> +}
> +
> +static void test_merged_requests(struct request_queue *q,
> + struct request *rq, struct request *next)
> +{
> + list_del_init(&next->queuelist);
> +}
> +
> +/*
> + * Dispatch a test request in case there is a running test Otherwise,
> dispatch
> + * a request that was queued by the FS to keep the card functional.
> + */
> +static int test_dispatch_requests(struct request_queue *q, int force)
> +{
> + struct test_data *td = q->elevator->elevator_data;
> + struct request *rq = NULL;
> +
> + switch (td->test_state) {
> + case TEST_IDLE:
> + if (!list_empty(&td->queue)) {
> + rq = list_entry(td->queue.next, struct request,
> + queuelist);
> + list_del_init(&rq->queuelist);
> + elv_dispatch_sort(q, rq);
> + return 1;
> + }
> + break;
> + case TEST_RUNNING:
> + if (td->next_req) {
> + rq = td->next_req->rq;
> + td->next_req =
> + latter_test_request(td->req_q, td->next_req);
> + if (!rq)
> + return 0;
> + print_req(rq);
> + elv_dispatch_sort(q, rq);
> + return 1;
> + }
> + break;
> + case TEST_COMPLETED:
> + default:
> + return 0;
> + }
> +
> + return 0;
> +}
> +
> +static void test_add_request(struct request_queue *q, struct request *rq)
> +{
> + struct test_data *td = q->elevator->elevator_data;
> +
> + list_add_tail(&rq->queuelist, &td->queue);
> +
> + /*
> + * The write requests can be followed by a FLUSH request that might
> + * cause unexpected results of the test.
> + */
> + if ((rq_data_dir(rq) == WRITE) && (td->test_state == TEST_RUNNING)) {
> + test_pr_debug("%s: got WRITE req in the middle of the test",
> + __func__);
> + td->fs_wr_reqs_during_test = true;
> + }
> +}
> +
> +static struct request *
> +test_former_request(struct request_queue *q, struct request *rq)
> +{
> + struct test_data *td = q->elevator->elevator_data;
> +
> + if (rq->queuelist.prev == &td->queue)
> + return NULL;
> + return list_entry(rq->queuelist.prev, struct request, queuelist);
> +}
> +
> +static struct request *
> +test_latter_request(struct request_queue *q, struct request *rq)
> +{
> + struct test_data *td = q->elevator->elevator_data;
> +
> + if (rq->queuelist.next == &td->queue)
> + return NULL;
> + return list_entry(rq->queuelist.next, struct request, queuelist);
> +}
> +
> +static int test_init_queue(struct request_queue *q)
> +{
> + struct blk_dev_test_type *__bdt;
> +
> + ptd = kmalloc_node(sizeof(struct test_data), GFP_KERNEL,
> + q->node);
> + if (!ptd) {
> + test_pr_err("%s: failed to allocate test data", __func__);
> + return -ENODEV;
> + }
> + memset((void *)ptd, 0, sizeof(struct test_data));
> + INIT_LIST_HEAD(&ptd->queue);
> + INIT_LIST_HEAD(&ptd->test_queue);
> + init_waitqueue_head(&ptd->wait_q);
> + ptd->req_q = q;
> + q->elevator->elevator_data = ptd;
> +
> + setup_timer(&ptd->timeout_timer, test_timeout_handler,
> + (unsigned long)ptd);
> +
> + spin_lock_init(&ptd->lock);
> +
> + if (test_debugfs_init(ptd)) {
> + test_pr_err("%s: Failed to create debugfs files", __func__);
> + return -ENODEV;
> + }
> +
> + list_for_each_entry(__bdt, &blk_dev_test_list, list)
> + __bdt->init_fn();
> +
> + return 0;
> +}
> +
> +static void test_exit_queue(struct elevator_queue *e)
> +{
> + struct test_data *td = e->elevator_data;
> + struct blk_dev_test_type *__bdt;
> +
> + BUG_ON(!list_empty(&td->queue));
> +
> + list_for_each_entry(__bdt, &blk_dev_test_list, list)
> + __bdt->exit_fn();
> +
> + test_debugfs_cleanup(td);
> +
> + kfree(td);
> +}
> +
> +static struct elevator_type elevator_test_iosched = {
> + .ops = {
> + .elevator_merge_req_fn = test_merged_requests,
> + .elevator_dispatch_fn = test_dispatch_requests,
> + .elevator_add_req_fn = test_add_request,
> + .elevator_former_req_fn = test_former_request,
> + .elevator_latter_req_fn = test_latter_request,
> + .elevator_init_fn = test_init_queue,
> + .elevator_exit_fn = test_exit_queue,
> + },
> + .elevator_name = "test-iosched",
> + .elevator_owner = THIS_MODULE,
> +};
> +
> +static int __init test_init(void)
> +{
> + elv_register(&elevator_test_iosched);
> +
> + return 0;
> +}
> +
> +static void __exit test_exit(void)
> +{
> + elv_unregister(&elevator_test_iosched);
> +}
> +
> +module_init(test_init);
> +module_exit(test_exit);
> +
> +MODULE_LICENSE("GPL v2");
> +MODULE_DESCRIPTION("Test IO scheduler");
> diff --git a/include/linux/test-iosched.h b/include/linux/test-iosched.h
> new file mode 100644
> index 0000000..8054409
> --- /dev/null
> +++ b/include/linux/test-iosched.h
> @@ -0,0 +1,233 @@
> +/* Copyright (c) 2012, Code Aurora Forum. All rights reserved.
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 and
> + * only version 2 as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + *
> + * The test scheduler allows to test the block device by dispatching
> + * specific requests according to the test case and declare PASS/FAIL
> + * according to the requests completion error code.
> + * Each test is exposed via debugfs and can be triggered by writing to
> + * the debugfs file.
> + *
> + */
> +
> +#ifndef _LINUX_TEST_IOSCHED_H
> +#define _LINUX_TEST_IOSCHED_H
> +
> +/*
> + * Patterns definitions for read/write requests data
> + */
> +#define TEST_PATTERN_SEQUENTIAL -1
> +#define TEST_PATTERN_5A 0x5A5A5A5A
> +#define TEST_PATTERN_FF 0xFFFFFFFF
> +#define TEST_NO_PATTERN 0xDEADBEEF
> +#define BIO_U32_SIZE 1024
> +
> +struct test_data;
> +
> +typedef int (prepare_test_fn) (struct test_data *);
> +typedef int (run_test_fn) (struct test_data *);
> +typedef int (check_test_result_fn) (struct test_data *);
> +typedef int (post_test_fn) (struct test_data *);
> +typedef char* (get_test_case_str_fn) (struct test_data *);
> +typedef void (blk_dev_test_init_fn) (void);
> +typedef void (blk_dev_test_exit_fn) (void);
> +
> +/**
> + * enum test_state - defines the state of the test
> + */
> +enum test_state {
> + TEST_IDLE,
> + TEST_RUNNING,
> + TEST_COMPLETED,
> +};
> +
> +/**
> + * enum test_results - defines the success orfailure of the test
> + */
> +enum test_results {
> + TEST_NO_RESULT,
> + TEST_FAILED,
> + TEST_PASSED,
> + TEST_NOT_SUPPORTED,
> +};
> +
> +/**
> + * enum req_unique_type - defines a unique request type
> + */
> +enum req_unique_type {
> + REQ_UNIQUE_NONE,
> + REQ_UNIQUE_DISCARD,
> + REQ_UNIQUE_FLUSH,
> +};
> +
> +/**
> + * struct test_debug - debugfs directories
> + * @debug_root: The test-iosched debugfs root directory
> + * @debug_utils_root: test-iosched debugfs utils root
> + * directory
> + * @debug_tests_root: test-iosched debugfs tests root
> + * directory
> + * @debug_test_result: Exposes the test result to the user
> + * space
> + * @start_sector: The start sector for read/write requests
> + */
> +struct test_debug {
> + struct dentry *debug_root;
> + struct dentry *debug_utils_root;
> + struct dentry *debug_tests_root;
> + struct dentry *debug_test_result;
> + struct dentry *start_sector;
> +};
> +
> +/**
> + * struct test_request - defines a test request
> + * @queuelist: The test requests list
> + * @bios_buffer: Write/read requests data buffer
> + * @buf_size: Write/read requests data buffer size (in
> + * bytes)
> + * @rq: A block request, to be dispatched
> + * @req_completed: A flag to indicate if the request was
> + * completed
> + * @req_result: Keeps the error code received in the
> + * request completion callback
> + * @is_err_expected: A flag to indicate if the request should
> + * fail
> + * @wr_rd_data_pattern: A pattern written to the write data
> + * buffer. Can be used in read requests to
> + * verify the data
> + * @req_id: A unique ID to identify a test request
> + * to ease the debugging of the test cases
> + */
> +struct test_request {
> + struct list_head queuelist;
> + unsigned int *bios_buffer;
> + int buf_size;
> + struct request *rq;
> + bool req_completed;
> + int req_result;
> + int is_err_expected;
> + int wr_rd_data_pattern;
> + int req_id;
> +};
> +
> +/**
> + * struct test_info - specific test information
> + * @testcase: The current running test case
> + * @timeout_msec: Test specific test timeout
> + * @buf_size: Write/read requests data buffer size (in
> + * bytes)
> + * @prepare_test_fn: Test specific test preparation callback
> + * @run_test_fn: Test specific test running callback
> + * @check_test_result_fn: Test specific test result checking
> + * callback
> + * @get_test_case_str_fn: Test specific function to get the test name
> + * @data: Test specific private data
> + */
> +struct test_info {
> + int testcase;
> + unsigned timeout_msec;
> + prepare_test_fn *prepare_test_fn;
> + run_test_fn *run_test_fn;
> + check_test_result_fn *check_test_result_fn;
> + post_test_fn *post_test_fn;
> + get_test_case_str_fn *get_test_case_str_fn;
> + void *data;
> +};
> +
> +/**
> + * struct blk_dev_test_type - identifies block device test
> + * @list: list head pointer
> + * @init_fn: block device test init callback
> + * @exit_fn: block device test exit callback
> + */
> +struct blk_dev_test_type {
> + struct list_head list;
> + blk_dev_test_init_fn *init_fn;
> + blk_dev_test_exit_fn *exit_fn;
> +};
> +
> +/**
> + * struct test_data - global test iosched data
> + * @queue: The test IO scheduler requests list
> + * @test_queue: The test requests list
> + * @next_req: Points to the next request to be
> + * dispatched from the test requests list
> + * @wait_q: A wait queue for waiting for the test
> + * requests completion
> + * @test_state: Indicates if there is a running test.
> + * Used for dispatch function
> + * @test_result: Indicates if the test passed or failed
> + * @debug: The test debugfs entries
> + * @req_q: The block layer request queue
> + * @num_of_write_bios: The number of write BIOs added to the test
> requests.
> + * Used to calcualte the sector number of
> + * new BIOs.
> + * @start_sector: The address of the first sector that can
> + * be accessed by the test
> + * @timeout_timer: A timer to verify test completion in
> + * case of non-completed requests
> + * @wr_rd_next_req_id: A unique ID to identify WRITE/READ
> + * request to ease the debugging of the
> + * test cases
> + * @unique_next_req_id: A unique ID to identify
> + * FLUSH/DISCARD/SANITIZE request to ease
> + * the debugging of the test cases
> + * @lock: A lock to verify running a single test
> + * at a time
> + * @test_info: A specific test data to be set by the
> + * test invokation function
> + * @ignore_round: A boolean variable indicating that a
> + * test round was disturbed by an external
> + * flush request, therefore disqualifying
> + * the results
> + */
> +struct test_data {
> + struct list_head queue;
> + struct list_head test_queue;
> + struct test_request *next_req;
> + wait_queue_head_t wait_q;
> + enum test_state test_state;
> + enum test_results test_result;
> + struct test_debug debug;
> + struct request_queue *req_q;
> + int num_of_write_bios;
> + u32 start_sector;
> + struct timer_list timeout_timer;
> + int wr_rd_next_req_id;
> + int unique_next_req_id;
> + spinlock_t lock;
> + struct test_info test_info;
> + bool fs_wr_reqs_during_test;
> + bool ignore_round;
> +};
> +
> +extern int test_iosched_start_test(struct test_info *t_info);
> +extern void test_iosched_mark_test_completion(void);
> +extern int test_iosched_add_unique_test_req(int is_err_expcted,
> + enum req_unique_type req_unique,
> + int start_sec, int nr_sects, rq_end_io_fn *end_req_io);
> +extern int test_iosched_add_wr_rd_test_req(int is_err_expcted,
> + int direction, int start_sec,
> + int num_bios, int pattern, rq_end_io_fn *end_req_io);
> +
> +extern struct dentry *test_iosched_get_debugfs_tests_root(void);
> +extern struct dentry *test_iosched_get_debugfs_utils_root(void);
> +
> +extern struct request_queue *test_iosched_get_req_queue(void);
> +
> +extern void test_iosched_set_test_result(int);
> +
> +void test_iosched_set_ignore_round(bool ignore_round);
> +
> +void test_iosched_register(struct blk_dev_test_type *bdt);
> +
> +void test_iosched_unregister(struct blk_dev_test_type *bdt);
> +
> +#endif /* _LINUX_TEST_IOSCHED_H */
> --
> 1.7.3.3
> --
> Sent by a consultant of the Qualcomm Innovation Center, Inc.
> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum.