[fio.git] / log.c

/*
 * Code related to writing an iolog of what a thread is doing, and to
 * later read that back and replay
 */
#include <stdio.h>
#include <stdlib.h>
#include <assert.h>
#include "list.h"
#include "fio.h"

static const char iolog_ver2[] = "fio version 2 iolog";

void queue_io_piece(struct thread_data *td, struct io_piece *ipo)
{
	list_add_tail(&ipo->list, &td->io_log_list);
	td->total_io_size += ipo->len;
}

void log_io_u(struct thread_data *td, struct io_u *io_u)
{
	const char *act[] = { "read", "write", "sync" };

	assert(io_u->ddir < 3);

	if (!td->o.write_iolog_file)
		return;

	fprintf(td->iolog_f, "%s %s %llu %lu\n", io_u->file->file_name,
						act[io_u->ddir], io_u->offset,
						io_u->buflen);
}

void log_file(struct thread_data *td, struct fio_file *f,
	      enum file_log_act what)
{
	const char *act[] = { "add", "open", "close" };

	assert(what < 3);

	if (!td->o.write_iolog_file)
		return;

	fprintf(td->iolog_f, "%s %s\n", f->file_name, act[what]);
}

static void iolog_delay(struct thread_data *td, unsigned long delay)
{
	unsigned long usec = utime_since_now(&td->last_issue);

	if (delay < usec)
		return;

	delay -= usec;

	/*
	 * less than 100 usec delay, just regard it as noise
	 */
	if (delay < 100)
		return;

	usec_sleep(td, delay);
}

int read_iolog_get(struct thread_data *td, struct io_u *io_u)
{
	struct io_piece *ipo;

	while (!list_empty(&td->io_log_list)) {
		ipo = list_entry(td->io_log_list.next, struct io_piece, list);
		list_del(&ipo->list);

		/*
		 * invalid ddir, this is a file action
		 */
		if (ipo->ddir == DDIR_INVAL) {
			struct fio_file *f = td->files[ipo->fileno];

			if (ipo->file_action == FIO_LOG_OPEN_FILE) {
				int ret;

				ret = td_io_open_file(td, f);
				if (!ret) {
					free(ipo);
					continue;
				}
				td_verror(td, ret, "iolog open file");
				return 1;
			} else if (ipo->file_action == FIO_LOG_CLOSE_FILE) {
				td_io_close_file(td, f);
				free(ipo);
				continue;
			}
		}

		io_u->offset = ipo->offset;
		io_u->buflen = ipo->len;
		io_u->ddir = ipo->ddir;
		io_u->file = td->files[ipo->fileno];
		get_file(io_u->file);

		dprint(FD_IO, "iolog: get %llu/%lu/%s\n", io_u->offset,
					io_u->buflen, io_u->file->file_name);

		if (ipo->delay)
			iolog_delay(td, ipo->delay);

		free(ipo);
		return 0;
	}

	td->done = 1;
	return 1;
}

void prune_io_piece_log(struct thread_data *td)
{
	struct io_piece *ipo;
	struct rb_node *n;

	while ((n = rb_first(&td->io_hist_tree)) != NULL) {
		ipo = rb_entry(n, struct io_piece, rb_node);
		rb_erase(n, &td->io_hist_tree);
		free(ipo);
	}

	while (!list_empty(&td->io_hist_list)) {
		ipo = list_entry(td->io_hist_list.next, struct io_piece, list);
		list_del(&ipo->list);
		free(ipo);
	}
}

/*
 * log a successful write, so we can unwind the log for verify
 */
void log_io_piece(struct thread_data *td, struct io_u *io_u)
{
	struct rb_node **p, *parent;
	struct io_piece *ipo, *__ipo;

	ipo = malloc(sizeof(struct io_piece));
	ipo->file = io_u->file;
	ipo->offset = io_u->offset;
	ipo->len = io_u->buflen;

	/*
	 * We don't need to sort the entries, if:
	 *
	 *	Sequential writes, or
	 *	Random writes that lay out the file as it goes along
	 *
	 * For both these cases, just reading back data in the order we
	 * wrote it out is the fastest.
	 */
	if (!td_random(td) || !td->o.overwrite) {
		INIT_LIST_HEAD(&ipo->list);
		list_add_tail(&ipo->list, &td->io_hist_list);
		return;
	}

	RB_CLEAR_NODE(&ipo->rb_node);
	p = &td->io_hist_tree.rb_node;
	parent = NULL;

	/*
	 * Sort the entry into the verification list
	 */
	while (*p) {
		parent = *p;

		__ipo = rb_entry(parent, struct io_piece, rb_node);
		if (ipo->offset <= __ipo->offset)
			p = &(*p)->rb_left;
		else
			p = &(*p)->rb_right;
	}

	rb_link_node(&ipo->rb_node, parent, p);
	rb_insert_color(&ipo->rb_node, &td->io_hist_tree);
}

void write_iolog_close(struct thread_data *td)
{
	fflush(td->iolog_f);
	fclose(td->iolog_f);
	free(td->iolog_buf);
	td->iolog_f = NULL;
	td->iolog_buf = NULL;
}

/*
 * Read version 2 iolog data. It is enhanced to include per-file logging,
 * syncs, etc.
 */
static int read_iolog2(struct thread_data *td, FILE *f)
{
	unsigned long long offset;
	unsigned int bytes;
	int reads, writes, fileno = 0, file_action = 0; /* stupid gcc */
	char *fname, *act;
	char *str, *p;
	enum fio_ddir rw;

	free_release_files(td);

	/*
	 * Read in the read iolog and store it, reuse the infrastructure
	 * for doing verifications.
	 */
	str = malloc(4096);
	fname = malloc(256+16);
	act = malloc(256+16);

	reads = writes = 0;
	while ((p = fgets(str, 4096, f)) != NULL) {
		struct io_piece *ipo;
		int r;

		r = sscanf(p, "%256s %256s %llu %u", fname, act, &offset,
									&bytes);
		if (r == 4) {
			/*
			 * Check action first
			 */
			if (!strcmp(act, "read"))
				rw = DDIR_READ;
			else if (!strcmp(act, "write"))
				rw = DDIR_WRITE;
			else if (!strcmp(act, "sync"))
				rw = DDIR_SYNC;
			else {
				log_err("fio: bad iolog file action: %s\n",
									act);
				continue;
			}
		} else if (r == 2) {
			rw = DDIR_INVAL;
			if (!strcmp(act, "add")) {
				td->o.nr_files++;
				fileno = add_file(td, fname);
				file_action = FIO_LOG_ADD_FILE;
				continue;
			} else if (!strcmp(act, "open")) {
				fileno = get_fileno(td, fname);
				file_action = FIO_LOG_OPEN_FILE;
			} else if (!strcmp(act, "close")) {
				fileno = get_fileno(td, fname);
				file_action = FIO_LOG_CLOSE_FILE;
			} else {
				log_err("fio: bad iolog file action: %s\n",
									act);
				continue;
			}
		} else {
			log_err("bad iolog2: %s", p);
			continue;
		}

		if (rw == DDIR_READ)
			reads++;
		else if (rw == DDIR_WRITE) {
			/*
			 * Don't add a write for ro mode
			 */
			if (read_only)
				continue;
			writes++;
		} else if (rw != DDIR_SYNC && rw != DDIR_INVAL) {
			log_err("bad ddir: %d\n", rw);
			continue;
		}

		/*
		 * Make note of file
		 */
		ipo = malloc(sizeof(*ipo));
		memset(ipo, 0, sizeof(*ipo));
		INIT_LIST_HEAD(&ipo->list);
		ipo->offset = offset;
		ipo->len = bytes;
		ipo->ddir = rw;
		if (bytes > td->o.max_bs[rw])
			td->o.max_bs[rw] = bytes;
		if (rw == DDIR_INVAL) {
			ipo->fileno = fileno;
			ipo->file_action = file_action;
		}
		queue_io_piece(td, ipo);
	}

	free(str);
	free(act);
	free(fname);

	if (writes && read_only) {
		log_err("fio: <%s> skips replay of %d writes due to"
			" read-only\n", td->o.name, writes);
		writes = 0;
	}

	if (!reads && !writes)
		return 1;
	else if (reads && !writes)
		td->o.td_ddir = TD_DDIR_READ;
	else if (!reads && writes)
		td->o.td_ddir = TD_DDIR_WRITE;
	else
		td->o.td_ddir = TD_DDIR_RW;

	return 0;
}

/*
 * Read version 1 iolog data.
 */
static int read_iolog(struct thread_data *td, FILE *f)
{
	log_err("fio: iolog version 1 is no longer supported\n");
	return 1;
}

/*
 * open iolog, check version, and call appropriate parser
 */
static int init_iolog_read(struct thread_data *td)
{
	char buffer[256], *p;
	FILE *f;
	int ret;

	f = fopen(td->o.read_iolog_file, "r");
	if (!f) {
		perror("fopen read iolog");
		return 1;
	}

	p = fgets(buffer, sizeof(buffer), f);
	if (!p) {
		td_verror(td, errno, "iolog read");
		log_err("fio: unable to read iolog\n");
		return 1;
	}

	/*
	 * version 2 of the iolog stores a specific string as the
	 * first line, check for that
	 */
	if (!strncmp(iolog_ver2, buffer, strlen(iolog_ver2)))
		ret = read_iolog2(td, f);
	else {
		/*
		 * seek back to the beginning
		 */
		if (fseek(f, 0, SEEK_SET) < 0) {
			td_verror(td, errno, "iolog read");
			log_err("fio: unable to read iolog\n");
			return 1;
		}

		ret = read_iolog(td, f);
	}

	fclose(f);
	return ret;
}

/*
 * Setup a log for storing io patterns.
 */
static int init_iolog_write(struct thread_data *td)
{
	struct fio_file *ff;
	FILE *f;
	unsigned int i;

	f = fopen(td->o.write_iolog_file, "w+");
	if (!f) {
		perror("fopen write iolog");
		return 1;
	}

	/*
	 * That's it for writing, setup a log buffer and we're done.
	  */
	td->iolog_f = f;
	td->iolog_buf = malloc(8192);
	setvbuf(f, td->iolog_buf, _IOFBF, 8192);

	/*
	 * write our version line
	 */
	if (fprintf(f, "%s\n", iolog_ver2) < 0) {
		perror("iolog init\n");
		return 1;
	}

	/*
	 * add all known files
	 */
	for_each_file(td, ff, i)
		log_file(td, ff, FIO_LOG_ADD_FILE);

	return 0;
}

int init_iolog(struct thread_data *td)
{
	int ret = 0;

	if (td->io_ops->flags & FIO_DISKLESSIO)
		return 0;

	if (td->o.read_iolog_file) {
		/*
		 * Check if it's a blktrace file and load that if possible.
		 * Otherwise assume it's a normal log file and load that.
		 */
		if (is_blktrace(td->o.read_iolog_file))
			ret = load_blktrace(td, td->o.read_iolog_file);
		else
			ret = init_iolog_read(td);
	} else if (td->o.write_iolog_file)
		ret = init_iolog_write(td);

	return ret;
}

void setup_log(struct io_log **log)
{
	struct io_log *l = malloc(sizeof(*l));

	l->nr_samples = 0;
	l->max_samples = 1024;
	l->log = malloc(l->max_samples * sizeof(struct io_sample));
	*log = l;
}

void __finish_log(struct io_log *log, const char *name)
{
	unsigned int i;
	FILE *f;

	f = fopen(name, "w");
	if (!f) {
		perror("fopen log");
		return;
	}

	for (i = 0; i < log->nr_samples; i++) {
		fprintf(f, "%lu, %lu, %u\n", log->log[i].time, log->log[i].val,
						log->log[i].ddir);
	}

	fclose(f);
	free(log->log);
	free(log);
}

void finish_log(struct thread_data *td, struct io_log *log, const char *name)
{
	char file_name[256];

	snprintf(file_name, 200, "client%d_%s.log", td->thread_number, name);
	__finish_log(log, file_name);
}
Commit	Line	Data
	1	/*
	2	* Code related to writing an iolog of what a thread is doing, and to
	3	* later read that back and replay
	4	*/
	5	#include <stdio.h>
	6	#include <stdlib.h>
	7	#include <assert.h>
	8	#include "list.h"
	9	#include "fio.h"
	10
	11	static const char iolog_ver2[] = "fio version 2 iolog";
	12
	13	void queue_io_piece(struct thread_data td, struct io_piece ipo)
	14	{
	15	list_add_tail(&ipo->list, &td->io_log_list);
	16	td->total_io_size += ipo->len;
	17	}
	18
	19	void log_io_u(struct thread_data td, struct io_u io_u)
	20	{
	21	const char *act[] = { "read", "write", "sync" };
	22
	23	assert(io_u->ddir < 3);
	24
	25	if (!td->o.write_iolog_file)
	26	return;
	27
	28	fprintf(td->iolog_f, "%s %s %llu %lu\n", io_u->file->file_name,
	29	act[io_u->ddir], io_u->offset,
	30	io_u->buflen);
	31	}
	32
	33	void log_file(struct thread_data td, struct fio_file f,
	34	enum file_log_act what)
	35	{
	36	const char *act[] = { "add", "open", "close" };
	37
	38	assert(what < 3);
	39
	40	if (!td->o.write_iolog_file)
	41	return;
	42
	43	fprintf(td->iolog_f, "%s %s\n", f->file_name, act[what]);
	44	}
	45
	46	static void iolog_delay(struct thread_data *td, unsigned long delay)
	47	{
	48	unsigned long usec = utime_since_now(&td->last_issue);
	49
	50	if (delay < usec)
	51	return;
	52
	53	delay -= usec;
	54
	55	/*
	56	* less than 100 usec delay, just regard it as noise
	57	*/
	58	if (delay < 100)
	59	return;
	60
	61	usec_sleep(td, delay);
	62	}
	63
	64	int read_iolog_get(struct thread_data td, struct io_u io_u)
	65	{
	66	struct io_piece *ipo;
	67
	68	while (!list_empty(&td->io_log_list)) {
	69	ipo = list_entry(td->io_log_list.next, struct io_piece, list);
	70	list_del(&ipo->list);
	71
	72	/*
	73	* invalid ddir, this is a file action
	74	*/
	75	if (ipo->ddir == DDIR_INVAL) {
	76	struct fio_file *f = td->files[ipo->fileno];
	77
	78	if (ipo->file_action == FIO_LOG_OPEN_FILE) {
	79	int ret;
	80
	81	ret = td_io_open_file(td, f);
	82	if (!ret) {
	83	free(ipo);
	84	continue;
	85	}
	86	td_verror(td, ret, "iolog open file");
	87	return 1;
	88	} else if (ipo->file_action == FIO_LOG_CLOSE_FILE) {
	89	td_io_close_file(td, f);
	90	free(ipo);
	91	continue;
	92	}
	93	}
	94
	95	io_u->offset = ipo->offset;
	96	io_u->buflen = ipo->len;
	97	io_u->ddir = ipo->ddir;
	98	io_u->file = td->files[ipo->fileno];
	99	get_file(io_u->file);
	100
	101	dprint(FD_IO, "iolog: get %llu/%lu/%s\n", io_u->offset,
	102	io_u->buflen, io_u->file->file_name);
	103
	104	if (ipo->delay)
	105	iolog_delay(td, ipo->delay);
	106
	107	free(ipo);
	108	return 0;
	109	}
	110
	111	td->done = 1;
	112	return 1;
	113	}
	114
	115	void prune_io_piece_log(struct thread_data *td)
	116	{
	117	struct io_piece *ipo;
	118	struct rb_node *n;
	119
	120	while ((n = rb_first(&td->io_hist_tree)) != NULL) {
	121	ipo = rb_entry(n, struct io_piece, rb_node);
	122	rb_erase(n, &td->io_hist_tree);
	123	free(ipo);
	124	}
	125
	126	while (!list_empty(&td->io_hist_list)) {
	127	ipo = list_entry(td->io_hist_list.next, struct io_piece, list);
	128	list_del(&ipo->list);
	129	free(ipo);
	130	}
	131	}
	132
	133	/*
	134	* log a successful write, so we can unwind the log for verify
	135	*/
	136	void log_io_piece(struct thread_data td, struct io_u io_u)
	137	{
	138	struct rb_node *p, parent;
	139	struct io_piece ipo, __ipo;
	140
	141	ipo = malloc(sizeof(struct io_piece));
	142	ipo->file = io_u->file;
	143	ipo->offset = io_u->offset;
	144	ipo->len = io_u->buflen;
	145
	146	/*
	147	* We don't need to sort the entries, if:
	148	*
	149	* Sequential writes, or
	150	* Random writes that lay out the file as it goes along
	151	*
	152	* For both these cases, just reading back data in the order we
	153	* wrote it out is the fastest.
	154	*/
	155	if (!td_random(td) \|\| !td->o.overwrite) {
	156	INIT_LIST_HEAD(&ipo->list);
	157	list_add_tail(&ipo->list, &td->io_hist_list);
	158	return;
	159	}
	160
	161	RB_CLEAR_NODE(&ipo->rb_node);
	162	p = &td->io_hist_tree.rb_node;
	163	parent = NULL;
	164
	165	/*
	166	* Sort the entry into the verification list
	167	*/
	168	while (*p) {
	169	parent = *p;
	170
	171	__ipo = rb_entry(parent, struct io_piece, rb_node);
	172	if (ipo->offset <= __ipo->offset)
	173	p = &(*p)->rb_left;
	174	else
	175	p = &(*p)->rb_right;
	176	}
	177
	178	rb_link_node(&ipo->rb_node, parent, p);
	179	rb_insert_color(&ipo->rb_node, &td->io_hist_tree);
	180	}
	181
	182	void write_iolog_close(struct thread_data *td)
	183	{
	184	fflush(td->iolog_f);
	185	fclose(td->iolog_f);
	186	free(td->iolog_buf);
	187	td->iolog_f = NULL;
	188	td->iolog_buf = NULL;
	189	}
	190
	191	/*
	192	* Read version 2 iolog data. It is enhanced to include per-file logging,
	193	* syncs, etc.
	194	*/
	195	static int read_iolog2(struct thread_data td, FILE f)
	196	{
	197	unsigned long long offset;
	198	unsigned int bytes;
	199	int reads, writes, fileno = 0, file_action = 0; /* stupid gcc */
	200	char fname, act;
	201	char str, p;
	202	enum fio_ddir rw;
	203
	204	free_release_files(td);
	205
	206	/*
	207	* Read in the read iolog and store it, reuse the infrastructure
	208	* for doing verifications.
	209	*/
	210	str = malloc(4096);
	211	fname = malloc(256+16);
	212	act = malloc(256+16);
	213
	214	reads = writes = 0;
	215	while ((p = fgets(str, 4096, f)) != NULL) {
	216	struct io_piece *ipo;
	217	int r;
	218
	219	r = sscanf(p, "%256s %256s %llu %u", fname, act, &offset,
	220	&bytes);
	221	if (r == 4) {
	222	/*
	223	* Check action first
	224	*/
	225	if (!strcmp(act, "read"))
	226	rw = DDIR_READ;
	227	else if (!strcmp(act, "write"))
	228	rw = DDIR_WRITE;
	229	else if (!strcmp(act, "sync"))
	230	rw = DDIR_SYNC;
	231	else {
	232	log_err("fio: bad iolog file action: %s\n",
	233	act);
	234	continue;
	235	}
	236	} else if (r == 2) {
	237	rw = DDIR_INVAL;
	238	if (!strcmp(act, "add")) {
	239	td->o.nr_files++;
	240	fileno = add_file(td, fname);
	241	file_action = FIO_LOG_ADD_FILE;
	242	continue;
	243	} else if (!strcmp(act, "open")) {
	244	fileno = get_fileno(td, fname);
	245	file_action = FIO_LOG_OPEN_FILE;
	246	} else if (!strcmp(act, "close")) {
	247	fileno = get_fileno(td, fname);
	248	file_action = FIO_LOG_CLOSE_FILE;
	249	} else {
	250	log_err("fio: bad iolog file action: %s\n",
	251	act);
	252	continue;
	253	}
	254	} else {
	255	log_err("bad iolog2: %s", p);
	256	continue;
	257	}
	258
	259	if (rw == DDIR_READ)
	260	reads++;
	261	else if (rw == DDIR_WRITE) {
	262	/*
	263	* Don't add a write for ro mode
	264	*/
	265	if (read_only)
	266	continue;
	267	writes++;
	268	} else if (rw != DDIR_SYNC && rw != DDIR_INVAL) {
	269	log_err("bad ddir: %d\n", rw);
	270	continue;
	271	}
	272
	273	/*
	274	* Make note of file
	275	*/
	276	ipo = malloc(sizeof(*ipo));
	277	memset(ipo, 0, sizeof(*ipo));
	278	INIT_LIST_HEAD(&ipo->list);
	279	ipo->offset = offset;
	280	ipo->len = bytes;
	281	ipo->ddir = rw;
	282	if (bytes > td->o.max_bs[rw])
	283	td->o.max_bs[rw] = bytes;
	284	if (rw == DDIR_INVAL) {
	285	ipo->fileno = fileno;
	286	ipo->file_action = file_action;
	287	}
	288	queue_io_piece(td, ipo);
	289	}
	290
	291	free(str);
	292	free(act);
	293	free(fname);
	294
	295	if (writes && read_only) {
	296	log_err("fio: <%s> skips replay of %d writes due to"
	297	" read-only\n", td->o.name, writes);
	298	writes = 0;
	299	}
	300
	301	if (!reads && !writes)
	302	return 1;
	303	else if (reads && !writes)
	304	td->o.td_ddir = TD_DDIR_READ;
	305	else if (!reads && writes)
	306	td->o.td_ddir = TD_DDIR_WRITE;
	307	else
	308	td->o.td_ddir = TD_DDIR_RW;
	309
	310	return 0;
	311	}
	312
	313	/*
	314	* Read version 1 iolog data.
	315	*/
	316	static int read_iolog(struct thread_data td, FILE f)
	317	{
	318	log_err("fio: iolog version 1 is no longer supported\n");
	319	return 1;
	320	}
	321
	322	/*
	323	* open iolog, check version, and call appropriate parser
	324	*/
	325	static int init_iolog_read(struct thread_data *td)
	326	{
	327	char buffer[256], *p;
	328	FILE *f;
	329	int ret;
	330
	331	f = fopen(td->o.read_iolog_file, "r");
	332	if (!f) {
	333	perror("fopen read iolog");
	334	return 1;
	335	}
	336
	337	p = fgets(buffer, sizeof(buffer), f);
	338	if (!p) {
	339	td_verror(td, errno, "iolog read");
	340	log_err("fio: unable to read iolog\n");
	341	return 1;
	342	}
	343
	344	/*
	345	* version 2 of the iolog stores a specific string as the
	346	* first line, check for that
	347	*/
	348	if (!strncmp(iolog_ver2, buffer, strlen(iolog_ver2)))
	349	ret = read_iolog2(td, f);
	350	else {
	351	/*
	352	* seek back to the beginning
	353	*/
	354	if (fseek(f, 0, SEEK_SET) < 0) {
	355	td_verror(td, errno, "iolog read");
	356	log_err("fio: unable to read iolog\n");
	357	return 1;
	358	}
	359
	360	ret = read_iolog(td, f);
	361	}
	362
	363	fclose(f);
	364	return ret;
	365	}
	366
	367	/*
	368	* Setup a log for storing io patterns.
	369	*/
	370	static int init_iolog_write(struct thread_data *td)
	371	{
	372	struct fio_file *ff;
	373	FILE *f;
	374	unsigned int i;
	375
	376	f = fopen(td->o.write_iolog_file, "w+");
	377	if (!f) {
	378	perror("fopen write iolog");
	379	return 1;
	380	}
	381
	382	/*
	383	* That's it for writing, setup a log buffer and we're done.
	384	*/
	385	td->iolog_f = f;
	386	td->iolog_buf = malloc(8192);
	387	setvbuf(f, td->iolog_buf, _IOFBF, 8192);
	388
	389	/*
	390	* write our version line
	391	*/
	392	if (fprintf(f, "%s\n", iolog_ver2) < 0) {
	393	perror("iolog init\n");
	394	return 1;
	395	}
	396
	397	/*
	398	* add all known files
	399	*/
	400	for_each_file(td, ff, i)
	401	log_file(td, ff, FIO_LOG_ADD_FILE);
	402
	403	return 0;
	404	}
	405
	406	int init_iolog(struct thread_data *td)
	407	{
	408	int ret = 0;
	409
	410	if (td->io_ops->flags & FIO_DISKLESSIO)
	411	return 0;
	412
	413	if (td->o.read_iolog_file) {
	414	/*
	415	* Check if it's a blktrace file and load that if possible.
	416	* Otherwise assume it's a normal log file and load that.
	417	*/
	418	if (is_blktrace(td->o.read_iolog_file))
	419	ret = load_blktrace(td, td->o.read_iolog_file);
	420	else
	421	ret = init_iolog_read(td);
	422	} else if (td->o.write_iolog_file)
	423	ret = init_iolog_write(td);
	424
	425	return ret;
	426	}
	427
	428	void setup_log(struct io_log **log)
	429	{
	430	struct io_log l = malloc(sizeof(l));
	431
	432	l->nr_samples = 0;
	433	l->max_samples = 1024;
	434	l->log = malloc(l->max_samples * sizeof(struct io_sample));
	435	*log = l;
	436	}
	437
	438	void __finish_log(struct io_log log, const char name)
	439	{
	440	unsigned int i;
	441	FILE *f;
	442
	443	f = fopen(name, "w");
	444	if (!f) {
	445	perror("fopen log");
	446	return;
	447	}
	448
	449	for (i = 0; i < log->nr_samples; i++) {
	450	fprintf(f, "%lu, %lu, %u\n", log->log[i].time, log->log[i].val,
	451	log->log[i].ddir);
	452	}
	453
	454	fclose(f);
	455	free(log->log);
	456	free(log);
	457	}
	458
	459	void finish_log(struct thread_data td, struct io_log log, const char *name)
	460	{
	461	char file_name[256];
	462
	463	snprintf(file_name, 200, "client%d_%s.log", td->thread_number, name);
	464	__finish_log(log, file_name);
	465	}