blob: 71e8669c3f32cadcd04f8c4b942f7d1a0838bf63 [file] [log] [blame]
/* 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;
}
ptd->test_info.test_duration = jiffies -
ptd->test_info.test_duration;
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_debug("%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;
case REQ_UNIQUE_SANITIZE:
bio->bi_rw = REQ_WRITE | REQ_SANITIZE;
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->test_info.testcase = 0;
ptd->test_state = TEST_IDLE;
free_test_requests(td);
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", __func__, test_name);
ret = prepare_test(ptd);
if (ret) {
test_pr_err("%s: failed to prepare the test\n",
__func__);
goto error;
}
ptd->test_info.test_duration = jiffies;
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);
t_info->test_duration = ptd->test_info.test_duration;
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 void *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 NULL;
}
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;
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 NULL;
}
list_for_each_entry(__bdt, &blk_dev_test_list, list)
__bdt->init_fn();
return ptd;
}
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");