blktrace.c - platform/external/fio - Gitiles

 /*
  * blktrace support code for fio
  */
 #include <stdio.h>
 #include <stdlib.h>
 #include <sys/stat.h>
 #include <dirent.h>

 #include "flist.h"
 #include "fio.h"
 #include "blktrace_api.h"

 #define TRACE_FIFO_SIZE	8192

 /*
  * fifo refill frontend, to avoid reading data in trace sized bites
  */
 static int refill_fifo(struct thread_data *td, struct fifo *fifo, int fd)
 {
 	char buf[TRACE_FIFO_SIZE];
 	unsigned int total;
 	int ret;

 	total = sizeof(buf);
 	if (total > fifo_room(fifo))
 		total = fifo_room(fifo);

 	ret = read(fd, buf, total);
 	if (ret < 0) {
 		td_verror(td, errno, "read blktrace file");
 		return -1;
 	}

 	if (ret > 0)
 		ret = fifo_put(fifo, buf, ret);

 	dprint(FD_BLKTRACE, "refill: filled %d bytes\n", ret);
 	return ret;
 }

 /*
  * Retrieve 'len' bytes from the fifo, refilling if necessary.
  */
 static int trace_fifo_get(struct thread_data *td, struct fifo *fifo, int fd,
 			  void *buf, unsigned int len)
 {
 	if (fifo_len(fifo) < len) {
 		int ret = refill_fifo(td, fifo, fd);

 		if (ret < 0)
 			return ret;
 	}

 	return fifo_get(fifo, buf, len);
 }

 /*
  * Just discard the pdu by seeking past it.
  */
 static int discard_pdu(struct thread_data *td, struct fifo *fifo, int fd,
 		       struct blk_io_trace *t)
 {
 	if (t->pdu_len == 0)
 		return 0;

 	dprint(FD_BLKTRACE, "discard pdu len %u\n", t->pdu_len);
 	return trace_fifo_get(td, fifo, fd, NULL, t->pdu_len);
 }

 /*
  * Check if this is a blktrace binary data file. We read a single trace
  * into memory and check for the magic signature.
  */
 int is_blktrace(const char *filename)
 {
 	struct blk_io_trace t;
 	int fd, ret;

 	fd = open(filename, O_RDONLY);
 	if (fd < 0)
 		return 0;

 	ret = read(fd, &t, sizeof(t));
 	close(fd);

 	if (ret < 0) {
 		perror("read blktrace");
 		return 0;
 	} else if (ret != sizeof(t)) {
 		log_err("fio: short read on blktrace file\n");
 		return 0;
 	}

 	if ((t.magic & 0xffffff00) == BLK_IO_TRACE_MAGIC)
 		return 1;

 	return 0;
 }

 static int lookup_device(struct thread_data *td, char *path, unsigned int maj,
 			 unsigned int min)
 {
 	struct dirent *dir;
 	struct stat st;
 	int found = 0;
 	DIR *D;

 	D = opendir(path);
 	if (!D)
 		return 0;

 	while ((dir = readdir(D)) != NULL) {
 		char full_path[256];

 		if (!strcmp(dir->d_name, ".") || !strcmp(dir->d_name, ".."))
 			continue;

 		sprintf(full_path, "%s%s%s", path, FIO_OS_PATH_SEPARATOR, dir->d_name);
 		if (lstat(full_path, &st) == -1) {
 			perror("lstat");
 			break;
 		}

 		if (S_ISDIR(st.st_mode)) {
 			found = lookup_device(td, full_path, maj, min);
 			if (found) {
 				strcpy(path, full_path);
 				break;
 			}
 		}

 		if (!S_ISBLK(st.st_mode))
 			continue;

 		/*
 		 * If replay_redirect is set then always return this device
 		 * upon lookup which overrides the device lookup based on
 		 * major minor in the actual blktrace
 		 */
 		if (td->o.replay_redirect) {
 			dprint(FD_BLKTRACE, "device lookup: %d/%d\n overridden"
 					" with: %s", maj, min,
 					td->o.replay_redirect);
 			strcpy(path, td->o.replay_redirect);
 			found = 1;
 			break;
 		}

 		if (maj == major(st.st_rdev) && min == minor(st.st_rdev)) {
 			dprint(FD_BLKTRACE, "device lookup: %d/%d\n", maj, min);
 			strcpy(path, full_path);
 			found = 1;
 			break;
 		}
 	}

 	closedir(D);
 	return found;
 }

 #define FMINORBITS	20
 #define FMINORMASK	((1U << FMINORBITS) - 1)
 #define FMAJOR(dev)	((unsigned int) ((dev) >> FMINORBITS))
 #define FMINOR(dev)	((unsigned int) ((dev) & FMINORMASK))

 static void trace_add_open_close_event(struct thread_data *td, int fileno, enum file_log_act action)
 {
 	struct io_piece *ipo;

 	ipo = calloc(1, sizeof(*ipo));
 	init_ipo(ipo);

 	ipo->ddir = DDIR_INVAL;
 	ipo->fileno = fileno;
 	ipo->file_action = action;
 	flist_add_tail(&ipo->list, &td->io_log_list);
 }

 static int trace_add_file(struct thread_data *td, __u32 device)
 {
 	static unsigned int last_maj, last_min, last_fileno;
 	unsigned int maj = FMAJOR(device);
 	unsigned int min = FMINOR(device);
 	struct fio_file *f;
 	char dev[256];
 	unsigned int i;

 	if (last_maj == maj && last_min == min)
 		return last_fileno;

 	last_maj = maj;
 	last_min = min;

 	/*
 	 * check for this file in our list
 	 */
 	for_each_file(td, f, i)
 		if (f->major == maj && f->minor == min) {
 			last_fileno = f->fileno;
 			return last_fileno;
 		}

 	strcpy(dev, "/dev");
 	if (lookup_device(td, dev, maj, min)) {
 		int fileno;

 		dprint(FD_BLKTRACE, "add devices %s\n", dev);
 		fileno = add_file_exclusive(td, dev);
 		trace_add_open_close_event(td, fileno, FIO_LOG_OPEN_FILE);
 		last_fileno = fileno;
 	}
 	return last_fileno;
 }

 /*
  * Store blk_io_trace data in an ipo for later retrieval.
  */
 static void store_ipo(struct thread_data *td, unsigned long long offset,
 		      unsigned int bytes, int rw, unsigned long long ttime,
 		      int fileno)
 {
 	struct io_piece *ipo = malloc(sizeof(*ipo));

 	init_ipo(ipo);

 	/*
 	 * the 512 is wrong here, it should be the hardware sector size...
 	 */
 	ipo->offset = offset * 512;
 	ipo->len = bytes;
 	ipo->delay = ttime / 1000;
 	if (rw)
 		ipo->ddir = DDIR_WRITE;
 	else
 		ipo->ddir = DDIR_READ;
 	ipo->fileno = fileno;

 	dprint(FD_BLKTRACE, "store ddir=%d, off=%llu, len=%lu, delay=%lu\n",
 							ipo->ddir, ipo->offset,
 							ipo->len, ipo->delay);
 	queue_io_piece(td, ipo);
 }

 static void handle_trace_notify(struct blk_io_trace *t)
 {
 	switch (t->action) {
 	case BLK_TN_PROCESS:
 		printf("got process notify: %x, %d\n", t->action, t->pid);
 		break;
 	case BLK_TN_TIMESTAMP:
 		printf("got timestamp notify: %x, %d\n", t->action, t->pid);
 		break;
 	case BLK_TN_MESSAGE:
 		break;
 	default:
 		dprint(FD_BLKTRACE, "unknown trace act %x\n", t->action);
 		break;
 	}
 }

 static void handle_trace_discard(struct thread_data *td, struct blk_io_trace *t,
 				 unsigned long long ttime, unsigned long *ios)
 {
 	struct io_piece *ipo = malloc(sizeof(*ipo));
 	int fileno;

 	init_ipo(ipo);
 	fileno = trace_add_file(td, t->device);

 	ios[DDIR_WRITE]++;
 	td->o.size += t->bytes;

 	memset(ipo, 0, sizeof(*ipo));
 	INIT_FLIST_HEAD(&ipo->list);

 	/*
 	 * the 512 is wrong here, it should be the hardware sector size...
 	 */
 	ipo->offset = t->sector * 512;
 	ipo->len = t->bytes;
 	ipo->delay = ttime / 1000;
 	ipo->ddir = DDIR_TRIM;
 	ipo->fileno = fileno;

 	dprint(FD_BLKTRACE, "store discard, off=%llu, len=%lu, delay=%lu\n",
 							ipo->offset, ipo->len,
 							ipo->delay);
 	queue_io_piece(td, ipo);
 }

 static void handle_trace_fs(struct thread_data *td, struct blk_io_trace *t,
 			    unsigned long long ttime, unsigned long *ios,
 			    unsigned int *bs)
 {
 	int rw;
 	int fileno;

 	fileno = trace_add_file(td, t->device);

 	rw = (t->action & BLK_TC_ACT(BLK_TC_WRITE)) != 0;

 	if (t->bytes > bs[rw])
 		bs[rw] = t->bytes;

 	ios[rw]++;
 	td->o.size += t->bytes;
 	store_ipo(td, t->sector, t->bytes, rw, ttime, fileno);
 }

 /*
  * We only care for queue traces, most of the others are side effects
  * due to internal workings of the block layer.
  */
 static void handle_trace(struct thread_data *td, struct blk_io_trace *t,
 			 unsigned long long ttime, unsigned long *ios,
 			 unsigned int *bs)
 {
 	if ((t->action & 0xffff) != __BLK_TA_QUEUE)
 		return;
 	if (t->action & BLK_TC_ACT(BLK_TC_PC))
 		return;

 	if (t->action & BLK_TC_ACT(BLK_TC_NOTIFY))
 		handle_trace_notify(t);
 	else if (t->action & BLK_TC_ACT(BLK_TC_DISCARD))
 		handle_trace_discard(td, t, ttime, ios);
 	else
 		handle_trace_fs(td, t, ttime, ios, bs);
 }

 /*
  * Load a blktrace file by reading all the blk_io_trace entries, and storing
  * them as io_pieces like the fio text version would do.
  */
 int load_blktrace(struct thread_data *td, const char *filename)
 {
 	unsigned long long ttime, delay;
 	struct blk_io_trace t;
 	unsigned long ios[2], skipped_writes;
 	unsigned int cpu;
 	unsigned int rw_bs[2];
 	struct fifo *fifo;
 	int fd, i;
 	struct fio_file *f;

 	fd = open(filename, O_RDONLY);
 	if (fd < 0) {
 		td_verror(td, errno, "open blktrace file");
 		return 1;
 	}

 	fifo = fifo_alloc(TRACE_FIFO_SIZE);

 	td->o.size = 0;

 	cpu = 0;
 	ttime = 0;
 	ios[0] = ios[1] = 0;
 	rw_bs[0] = rw_bs[1] = 0;
 	skipped_writes = 0;
 	do {
 		int ret = trace_fifo_get(td, fifo, fd, &t, sizeof(t));

 		if (ret < 0)
 			goto err;
 		else if (!ret)
 			break;
 		else if (ret < (int) sizeof(t)) {
 			log_err("fio: short fifo get\n");
 			break;
 		}

 		if ((t.magic & 0xffffff00) != BLK_IO_TRACE_MAGIC) {
 			log_err("fio: bad magic in blktrace data: %x\n",
 								t.magic);
 			goto err;
 		}
 		if ((t.magic & 0xff) != BLK_IO_TRACE_VERSION) {
 			log_err("fio: bad blktrace version %d\n",
 								t.magic & 0xff);
 			goto err;
 		}
 		ret = discard_pdu(td, fifo, fd, &t);
 		if (ret < 0) {
 			td_verror(td, ret, "blktrace lseek");
 			goto err;
 		} else if (t.pdu_len != ret) {
 			log_err("fio: discarded %d of %d\n", ret, t.pdu_len);
 			goto err;
 		}
 		if ((t.action & BLK_TC_ACT(BLK_TC_NOTIFY)) == 0) {
 			if (!ttime) {
 				ttime = t.time;
 				cpu = t.cpu;
 			}

 			delay = 0;
 			if (cpu == t.cpu)
 				delay = t.time - ttime;
 			if ((t.action & BLK_TC_ACT(BLK_TC_WRITE)) && read_only)
 				skipped_writes++;
 			else {
 				/*
 				 * set delay to zero if no_stall enabled for
 				 * fast replay
 				 */
 				if (td->o.no_stall)
 					delay = 0;

 				handle_trace(td, &t, delay, ios, rw_bs);
 			}

 			ttime = t.time;
 			cpu = t.cpu;
 		} else {
 			delay = 0;
 			handle_trace(td, &t, delay, ios, rw_bs);
 		}
 	} while (1);

 	for (i = 0; i < td->files_index; i++) {
 		f= td->files[i];
 		trace_add_open_close_event(td, f->fileno, FIO_LOG_CLOSE_FILE);
 	}

 	fifo_free(fifo);
 	close(fd);

 	if (skipped_writes)
 		log_err("fio: %s skips replay of %lu writes due to read-only\n",
 						td->o.name, skipped_writes);

 	if (!ios[DDIR_READ] && !ios[DDIR_WRITE]) {
 		log_err("fio: found no ios in blktrace data\n");
 		return 1;
 	} else if (ios[DDIR_READ] && !ios[DDIR_READ]) {
 		td->o.td_ddir = TD_DDIR_READ;
 		td->o.max_bs[DDIR_READ] = rw_bs[DDIR_READ];
 	} else if (!ios[DDIR_READ] && ios[DDIR_WRITE]) {
 		td->o.td_ddir = TD_DDIR_WRITE;
 		td->o.max_bs[DDIR_WRITE] = rw_bs[DDIR_WRITE];
 	} else {
 		td->o.td_ddir = TD_DDIR_RW;
 		td->o.max_bs[DDIR_READ] = rw_bs[DDIR_READ];
 		td->o.max_bs[DDIR_WRITE] = rw_bs[DDIR_WRITE];
 	}

 	/*
 	 * We need to do direct/raw ios to the device, to avoid getting
 	 * read-ahead in our way.
 	 */
 	td->o.odirect = 1;

 	return 0;
 err:
 	close(fd);
 	fifo_free(fifo);
 	return 1;
 }
	/*
	* blktrace support code for fio
	*/
	#include <stdio.h>
	#include <stdlib.h>
	#include <sys/stat.h>
	#include <dirent.h>

	#include "flist.h"
	#include "fio.h"
	#include "blktrace_api.h"

	#define TRACE_FIFO_SIZE 8192

	/*
	* fifo refill frontend, to avoid reading data in trace sized bites
	*/
	static int refill_fifo(struct thread_data td, struct fifo fifo, int fd)
	{
	char buf[TRACE_FIFO_SIZE];
	unsigned int total;
	int ret;

	total = sizeof(buf);
	if (total > fifo_room(fifo))
	total = fifo_room(fifo);

	ret = read(fd, buf, total);
	if (ret < 0) {
	td_verror(td, errno, "read blktrace file");
	return -1;
	}

	if (ret > 0)
	ret = fifo_put(fifo, buf, ret);

	dprint(FD_BLKTRACE, "refill: filled %d bytes\n", ret);
	return ret;
	}

	/*
	* Retrieve 'len' bytes from the fifo, refilling if necessary.
	*/
	static int trace_fifo_get(struct thread_data td, struct fifo fifo, int fd,
	void *buf, unsigned int len)
	{
	if (fifo_len(fifo) < len) {
	int ret = refill_fifo(td, fifo, fd);

	if (ret < 0)
	return ret;
	}

	return fifo_get(fifo, buf, len);
	}

	/*
	* Just discard the pdu by seeking past it.
	*/
	static int discard_pdu(struct thread_data td, struct fifo fifo, int fd,
	struct blk_io_trace *t)
	{
	if (t->pdu_len == 0)
	return 0;

	dprint(FD_BLKTRACE, "discard pdu len %u\n", t->pdu_len);
	return trace_fifo_get(td, fifo, fd, NULL, t->pdu_len);
	}

	/*
	* Check if this is a blktrace binary data file. We read a single trace
	* into memory and check for the magic signature.
	*/
	int is_blktrace(const char *filename)
	{
	struct blk_io_trace t;
	int fd, ret;

	fd = open(filename, O_RDONLY);
	if (fd < 0)
	return 0;

	ret = read(fd, &t, sizeof(t));
	close(fd);

	if (ret < 0) {
	perror("read blktrace");
	return 0;
	} else if (ret != sizeof(t)) {
	log_err("fio: short read on blktrace file\n");
	return 0;
	}

	if ((t.magic & 0xffffff00) == BLK_IO_TRACE_MAGIC)
	return 1;

	return 0;
	}

	static int lookup_device(struct thread_data td, char path, unsigned int maj,
	unsigned int min)
	{
	struct dirent *dir;
	struct stat st;
	int found = 0;
	DIR *D;

	D = opendir(path);
	if (!D)
	return 0;

	while ((dir = readdir(D)) != NULL) {
	char full_path[256];

	if (!strcmp(dir->d_name, ".") \|\| !strcmp(dir->d_name, ".."))
	continue;

	sprintf(full_path, "%s%s%s", path, FIO_OS_PATH_SEPARATOR, dir->d_name);
	if (lstat(full_path, &st) == -1) {
	perror("lstat");
	break;
	}

	if (S_ISDIR(st.st_mode)) {
	found = lookup_device(td, full_path, maj, min);
	if (found) {
	strcpy(path, full_path);
	break;
	}
	}

	if (!S_ISBLK(st.st_mode))
	continue;

	/*
	* If replay_redirect is set then always return this device
	* upon lookup which overrides the device lookup based on
	* major minor in the actual blktrace
	*/
	if (td->o.replay_redirect) {
	dprint(FD_BLKTRACE, "device lookup: %d/%d\n overridden"
	" with: %s", maj, min,
	td->o.replay_redirect);
	strcpy(path, td->o.replay_redirect);
	found = 1;
	break;
	}

	if (maj == major(st.st_rdev) && min == minor(st.st_rdev)) {
	dprint(FD_BLKTRACE, "device lookup: %d/%d\n", maj, min);
	strcpy(path, full_path);
	found = 1;
	break;
	}
	}

	closedir(D);
	return found;
	}

	#define FMINORBITS 20
	#define FMINORMASK ((1U << FMINORBITS) - 1)
	#define FMAJOR(dev) ((unsigned int) ((dev) >> FMINORBITS))
	#define FMINOR(dev) ((unsigned int) ((dev) & FMINORMASK))

	static void trace_add_open_close_event(struct thread_data *td, int fileno, enum file_log_act action)
	{
	struct io_piece *ipo;

	ipo = calloc(1, sizeof(*ipo));
	init_ipo(ipo);

	ipo->ddir = DDIR_INVAL;
	ipo->fileno = fileno;
	ipo->file_action = action;
	flist_add_tail(&ipo->list, &td->io_log_list);
	}

	static int trace_add_file(struct thread_data *td, __u32 device)
	{
	static unsigned int last_maj, last_min, last_fileno;
	unsigned int maj = FMAJOR(device);
	unsigned int min = FMINOR(device);
	struct fio_file *f;
	char dev[256];
	unsigned int i;

	if (last_maj == maj && last_min == min)
	return last_fileno;

	last_maj = maj;
	last_min = min;

	/*
	* check for this file in our list
	*/
	for_each_file(td, f, i)
	if (f->major == maj && f->minor == min) {
	last_fileno = f->fileno;
	return last_fileno;
	}

	strcpy(dev, "/dev");
	if (lookup_device(td, dev, maj, min)) {
	int fileno;

	dprint(FD_BLKTRACE, "add devices %s\n", dev);
	fileno = add_file_exclusive(td, dev);
	trace_add_open_close_event(td, fileno, FIO_LOG_OPEN_FILE);
	last_fileno = fileno;
	}
	return last_fileno;
	}

	/*
	* Store blk_io_trace data in an ipo for later retrieval.
	*/
	static void store_ipo(struct thread_data *td, unsigned long long offset,
	unsigned int bytes, int rw, unsigned long long ttime,
	int fileno)
	{
	struct io_piece ipo = malloc(sizeof(ipo));

	init_ipo(ipo);

	/*
	* the 512 is wrong here, it should be the hardware sector size...
	*/
	ipo->offset = offset * 512;
	ipo->len = bytes;
	ipo->delay = ttime / 1000;
	if (rw)
	ipo->ddir = DDIR_WRITE;
	else
	ipo->ddir = DDIR_READ;
	ipo->fileno = fileno;

	dprint(FD_BLKTRACE, "store ddir=%d, off=%llu, len=%lu, delay=%lu\n",
	ipo->ddir, ipo->offset,
	ipo->len, ipo->delay);
	queue_io_piece(td, ipo);
	}

	static void handle_trace_notify(struct blk_io_trace *t)
	{
	switch (t->action) {
	case BLK_TN_PROCESS:
	printf("got process notify: %x, %d\n", t->action, t->pid);
	break;
	case BLK_TN_TIMESTAMP:
	printf("got timestamp notify: %x, %d\n", t->action, t->pid);
	break;
	case BLK_TN_MESSAGE:
	break;
	default:
	dprint(FD_BLKTRACE, "unknown trace act %x\n", t->action);
	break;
	}
	}

	static void handle_trace_discard(struct thread_data td, struct blk_io_trace t,
	unsigned long long ttime, unsigned long *ios)
	{
	struct io_piece ipo = malloc(sizeof(ipo));
	int fileno;

	init_ipo(ipo);
	fileno = trace_add_file(td, t->device);

	ios[DDIR_WRITE]++;
	td->o.size += t->bytes;

	memset(ipo, 0, sizeof(*ipo));
	INIT_FLIST_HEAD(&ipo->list);

	/*
	* the 512 is wrong here, it should be the hardware sector size...
	*/
	ipo->offset = t->sector * 512;
	ipo->len = t->bytes;
	ipo->delay = ttime / 1000;
	ipo->ddir = DDIR_TRIM;
	ipo->fileno = fileno;

	dprint(FD_BLKTRACE, "store discard, off=%llu, len=%lu, delay=%lu\n",
	ipo->offset, ipo->len,
	ipo->delay);
	queue_io_piece(td, ipo);
	}

	static void handle_trace_fs(struct thread_data td, struct blk_io_trace t,
	unsigned long long ttime, unsigned long *ios,
	unsigned int *bs)
	{
	int rw;
	int fileno;

	fileno = trace_add_file(td, t->device);

	rw = (t->action & BLK_TC_ACT(BLK_TC_WRITE)) != 0;

	if (t->bytes > bs[rw])
	bs[rw] = t->bytes;

	ios[rw]++;
	td->o.size += t->bytes;
	store_ipo(td, t->sector, t->bytes, rw, ttime, fileno);
	}

	/*
	* We only care for queue traces, most of the others are side effects
	* due to internal workings of the block layer.
	*/
	static void handle_trace(struct thread_data td, struct blk_io_trace t,
	unsigned long long ttime, unsigned long *ios,
	unsigned int *bs)
	{
	if ((t->action & 0xffff) != __BLK_TA_QUEUE)
	return;
	if (t->action & BLK_TC_ACT(BLK_TC_PC))
	return;

	if (t->action & BLK_TC_ACT(BLK_TC_NOTIFY))
	handle_trace_notify(t);
	else if (t->action & BLK_TC_ACT(BLK_TC_DISCARD))
	handle_trace_discard(td, t, ttime, ios);
	else
	handle_trace_fs(td, t, ttime, ios, bs);
	}

	/*
	* Load a blktrace file by reading all the blk_io_trace entries, and storing
	* them as io_pieces like the fio text version would do.
	*/
	int load_blktrace(struct thread_data td, const char filename)
	{
	unsigned long long ttime, delay;
	struct blk_io_trace t;
	unsigned long ios[2], skipped_writes;
	unsigned int cpu;
	unsigned int rw_bs[2];
	struct fifo *fifo;
	int fd, i;
	struct fio_file *f;

	fd = open(filename, O_RDONLY);
	if (fd < 0) {
	td_verror(td, errno, "open blktrace file");
	return 1;
	}

	fifo = fifo_alloc(TRACE_FIFO_SIZE);

	td->o.size = 0;

	cpu = 0;
	ttime = 0;
	ios[0] = ios[1] = 0;
	rw_bs[0] = rw_bs[1] = 0;
	skipped_writes = 0;
	do {
	int ret = trace_fifo_get(td, fifo, fd, &t, sizeof(t));

	if (ret < 0)
	goto err;
	else if (!ret)
	break;
	else if (ret < (int) sizeof(t)) {
	log_err("fio: short fifo get\n");
	break;
	}

	if ((t.magic & 0xffffff00) != BLK_IO_TRACE_MAGIC) {
	log_err("fio: bad magic in blktrace data: %x\n",
	t.magic);
	goto err;
	}
	if ((t.magic & 0xff) != BLK_IO_TRACE_VERSION) {
	log_err("fio: bad blktrace version %d\n",
	t.magic & 0xff);
	goto err;
	}
	ret = discard_pdu(td, fifo, fd, &t);
	if (ret < 0) {
	td_verror(td, ret, "blktrace lseek");
	goto err;
	} else if (t.pdu_len != ret) {
	log_err("fio: discarded %d of %d\n", ret, t.pdu_len);
	goto err;
	}
	if ((t.action & BLK_TC_ACT(BLK_TC_NOTIFY)) == 0) {
	if (!ttime) {
	ttime = t.time;
	cpu = t.cpu;
	}

	delay = 0;
	if (cpu == t.cpu)
	delay = t.time - ttime;
	if ((t.action & BLK_TC_ACT(BLK_TC_WRITE)) && read_only)
	skipped_writes++;
	else {
	/*
	* set delay to zero if no_stall enabled for
	* fast replay
	*/
	if (td->o.no_stall)
	delay = 0;

	handle_trace(td, &t, delay, ios, rw_bs);
	}

	ttime = t.time;
	cpu = t.cpu;
	} else {
	delay = 0;
	handle_trace(td, &t, delay, ios, rw_bs);
	}
	} while (1);

	for (i = 0; i < td->files_index; i++) {
	f= td->files[i];
	trace_add_open_close_event(td, f->fileno, FIO_LOG_CLOSE_FILE);
	}

	fifo_free(fifo);
	close(fd);

	if (skipped_writes)
	log_err("fio: %s skips replay of %lu writes due to read-only\n",
	td->o.name, skipped_writes);

	if (!ios[DDIR_READ] && !ios[DDIR_WRITE]) {
	log_err("fio: found no ios in blktrace data\n");
	return 1;
	} else if (ios[DDIR_READ] && !ios[DDIR_READ]) {
	td->o.td_ddir = TD_DDIR_READ;
	td->o.max_bs[DDIR_READ] = rw_bs[DDIR_READ];
	} else if (!ios[DDIR_READ] && ios[DDIR_WRITE]) {
	td->o.td_ddir = TD_DDIR_WRITE;
	td->o.max_bs[DDIR_WRITE] = rw_bs[DDIR_WRITE];
	} else {
	td->o.td_ddir = TD_DDIR_RW;
	td->o.max_bs[DDIR_READ] = rw_bs[DDIR_READ];
	td->o.max_bs[DDIR_WRITE] = rw_bs[DDIR_WRITE];
	}

	/*
	* We need to do direct/raw ios to the device, to avoid getting
	* read-ahead in our way.
	*/
	td->o.odirect = 1;

	return 0;
	err:
	close(fd);
	fifo_free(fifo);
	return 1;
	}