X-Git-Url: https://git.kernel.dk/?p=fio.git;a=blobdiff_plain;f=blktrace.c;h=8a246613d43338d2f715dca0031dafbf164bcbef;hp=68ba964a3a363c6f5e85ac19e5410134e1943238;hb=refs%2Fheads%2Fmaster;hpb=49ffb4a2e1ac3026d77d9e1c03edc2753fcec41b

diff --git a/blktrace.c b/blktrace.c
index 68ba964a..ef9ce6bf 100644
--- a/blktrace.c
+++ b/blktrace.c
@@ -3,144 +3,77 @@
  */
 #include <stdio.h>
 #include <stdlib.h>
-#include <sys/stat.h>
-#include <dirent.h>
+#include <unistd.h>
+#include <errno.h>
+#include <sys/sysmacros.h>
 
 #include "flist.h"
 #include "fio.h"
+#include "iolog.h"
+#include "blktrace.h"
 #include "blktrace_api.h"
+#include "oslib/linux-dev-lookup.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);
-}
+struct file_cache {
+	unsigned int maj;
+	unsigned int min;
+	unsigned int fileno;
+};
 
 /*
  * 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)
+static int discard_pdu(FILE* f, 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);
+	if (fseek(f, t->pdu_len, SEEK_CUR) < 0)
+		return -errno;
+
+	return 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)
+bool is_blktrace(const char *filename, int *need_swap)
 {
 	struct blk_io_trace t;
 	int fd, ret;
 
 	fd = open(filename, O_RDONLY);
 	if (fd < 0)
-		return 0;
+		return false;
 
 	ret = read(fd, &t, sizeof(t));
 	close(fd);
 
 	if (ret < 0) {
 		perror("read blktrace");
-		return 0;
+		return false;
 	} else if (ret != sizeof(t)) {
 		log_err("fio: short read on blktrace file\n");
-		return 0;
+		return false;
 	}
 
-	if ((t.magic & 0xffffff00) == BLK_IO_TRACE_MAGIC)
-		return 1;
-
-	return 0;
-}
-
-static int lookup_device(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", path, dir->d_name);
-		if (lstat(full_path, &st) == -1) {
-			perror("lstat");
-			break;
-		}
-
-		if (S_ISDIR(st.st_mode)) {
-			found = lookup_device(full_path, maj, min);
-			if (found) {
-				strcpy(path, full_path);
-				break;
-			}
-		}
-
-		if (!S_ISBLK(st.st_mode))
-			continue;
+	if ((t.magic & 0xffffff00) == BLK_IO_TRACE_MAGIC) {
+		*need_swap = 0;
+		return true;
+	}
 
-		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;
-		}
+	/*
+	 * Maybe it needs to be endian swapped...
+	 */
+	t.magic = fio_swap32(t.magic);
+	if ((t.magic & 0xffffff00) == BLK_IO_TRACE_MAGIC) {
+		*need_swap = 1;
+		return true;
 	}
 
-	closedir(D);
-	return found;
+	return false;
 }
 
 #define FMINORBITS	20
@@ -148,70 +81,97 @@ static int lookup_device(char *path, unsigned int maj, unsigned int min)
 #define FMAJOR(dev)	((unsigned int) ((dev) >> FMINORBITS))
 #define FMINOR(dev)	((unsigned int) ((dev) & FMINORMASK))
 
-static void trace_add_open_event(struct thread_data *td, int fileno)
+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 = FIO_LOG_OPEN_FILE;
+	ipo->file_action = action;
 	flist_add_tail(&ipo->list, &td->io_log_list);
 }
 
-static void trace_add_file(struct thread_data *td, __u32 device)
+static int trace_add_file(struct thread_data *td, __u32 device,
+			  struct file_cache *cache)
 {
-	static unsigned int last_maj, last_min;
 	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;
+	if (cache->maj == maj && cache->min == min)
+		return cache->fileno;
 
-	last_maj = maj;
-	last_min = min;
+	cache->maj = maj;
+	cache->min = min;
 
 	/*
 	 * check for this file in our list
 	 */
 	for_each_file(td, f, i)
-		if (f->major == maj && f->minor == min)
-			return;
+		if (f->major == maj && f->minor == min) {
+			cache->fileno = f->fileno;
+			return cache->fileno;
+		}
 
 	strcpy(dev, "/dev");
-	if (lookup_device(dev, maj, min)) {
+	if (blktrace_lookup_device(td->o.replay_redirect, dev, maj, min)) {
 		int fileno;
 
+		if (td->o.replay_redirect)
+			dprint(FD_BLKTRACE, "device lookup: %d/%d\n overridden"
+					" with: %s\n", maj, min,
+					td->o.replay_redirect);
+		else
+			dprint(FD_BLKTRACE, "device lookup: %d/%d\n", maj, min);
+
 		dprint(FD_BLKTRACE, "add devices %s\n", dev);
 		fileno = add_file_exclusive(td, dev);
-		trace_add_open_event(td, fileno);
+		td->o.open_files++;
+		td->files[fileno]->major = maj;
+		td->files[fileno]->minor = min;
+		trace_add_open_close_event(td, fileno, FIO_LOG_OPEN_FILE);
+		cache->fileno = fileno;
 	}
+
+	return cache->fileno;
+}
+
+static void t_bytes_align(struct thread_options *o, struct blk_io_trace *t)
+{
+	if (!o->replay_align)
+		return;
+
+	t->bytes = (t->bytes + o->replay_align - 1) & ~(o->replay_align - 1);
 }
 
 /*
  * 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)
+		      unsigned int bytes, int rw, unsigned long long ttime,
+		      int fileno)
 {
-	struct io_piece *ipo = malloc(sizeof(*ipo));
+	struct io_piece *ipo;
+
+	ipo = calloc(1, sizeof(*ipo));
+	init_ipo(ipo);
 
-	memset(ipo, 0, sizeof(*ipo));
-	INIT_FLIST_HEAD(&ipo->list);
-	/*
-	 * the 512 is wrong here, it should be the hardware sector size...
-	 */
 	ipo->offset = offset * 512;
+	if (td->o.replay_scale)
+		ipo->offset = ipo->offset / td->o.replay_scale;
+	ipo_bytes_align(td->o.replay_align, ipo);
 	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,
@@ -219,99 +179,307 @@ static void store_ipo(struct thread_data *td, unsigned long long offset,
 	queue_io_piece(td, ipo);
 }
 
-static void handle_trace_notify(struct blk_io_trace *t)
+static bool 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);
+		dprint(FD_BLKTRACE, "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);
+		dprint(FD_BLKTRACE, "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;
 	}
+	return false;
+}
+
+static bool handle_trace_discard(struct thread_data *td,
+				 struct blk_io_trace *t,
+				 unsigned long long ttime,
+				 unsigned long *ios, unsigned long long *bs,
+				 struct file_cache *cache)
+{
+	struct io_piece *ipo;
+	int fileno;
+
+	if (td->o.replay_skip & (1u << DDIR_TRIM))
+		return false;
+
+	ipo = calloc(1, sizeof(*ipo));
+	init_ipo(ipo);
+	fileno = trace_add_file(td, t->device, cache);
+
+	ios[DDIR_TRIM]++;
+	if (t->bytes > bs[DDIR_TRIM])
+		bs[DDIR_TRIM] = t->bytes;
+
+	td->o.size += t->bytes;
+
+	INIT_FLIST_HEAD(&ipo->list);
+
+	ipo->offset = t->sector * 512;
+	if (td->o.replay_scale)
+		ipo->offset = ipo->offset / td->o.replay_scale;
+	ipo_bytes_align(td->o.replay_align, ipo);
+	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);
+	return true;
+}
+
+static void dump_trace(struct blk_io_trace *t)
+{
+	log_err("blktrace: ignoring zero byte trace: action=%x\n", t->action);
 }
 
-static void handle_trace_fs(struct thread_data *td, struct blk_io_trace *t,
+static bool handle_trace_fs(struct thread_data *td, struct blk_io_trace *t,
 			    unsigned long long ttime, unsigned long *ios,
-			    unsigned int *bs)
+			    unsigned long long *bs, struct file_cache *cache)
 {
 	int rw;
+	int fileno;
 
-	trace_add_file(td, t->device);
+	fileno = trace_add_file(td, t->device, cache);
 
 	rw = (t->action & BLK_TC_ACT(BLK_TC_WRITE)) != 0;
 
+	if (rw) {
+		if (td->o.replay_skip & (1u << DDIR_WRITE))
+			return false;
+	} else {
+		if (td->o.replay_skip & (1u << DDIR_READ))
+			return false;
+	}
+
+	if (!t->bytes) {
+		if (!fio_did_warn(FIO_WARN_BTRACE_ZERO))
+			dump_trace(t);
+		return false;
+	}
+
 	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);
+	store_ipo(td, t->sector, t->bytes, rw, ttime, fileno);
+	return true;
+}
+
+static bool handle_trace_flush(struct thread_data *td, struct blk_io_trace *t,
+			       unsigned long long ttime, unsigned long *ios,
+			       struct file_cache *cache)
+{
+	struct io_piece *ipo;
+	int fileno;
+
+	if (td->o.replay_skip & (1u << DDIR_SYNC))
+		return false;
+
+	ipo = calloc(1, sizeof(*ipo));
+	init_ipo(ipo);
+	fileno = trace_add_file(td, t->device, cache);
+
+	ipo->delay = ttime / 1000;
+	ipo->ddir = DDIR_SYNC;
+	ipo->fileno = fileno;
+
+	ios[DDIR_SYNC]++;
+	dprint(FD_BLKTRACE, "store flush delay=%lu\n", ipo->delay);
+
+	if (!(td->flags & TD_F_SYNCS))
+		td->flags |= TD_F_SYNCS;
+
+	queue_io_piece(td, ipo);
+	return true;
 }
 
 /*
  * 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)
+static bool queue_trace(struct thread_data *td, struct blk_io_trace *t,
+			 unsigned long *ios, unsigned long long *bs,
+			 struct file_cache *cache)
 {
+	unsigned long long *last_ttime = &td->io_log_last_ttime;
+	unsigned long long delay = 0;
+
 	if ((t->action & 0xffff) != __BLK_TA_QUEUE)
-		return;
-	if (t->action & BLK_TC_ACT(BLK_TC_PC))
-		return;
+		return false;
+
+	if (!(t->action & BLK_TC_ACT(BLK_TC_NOTIFY))) {
+		delay = delay_since_ttime(td, t->time);
+		*last_ttime = t->time;
+	}
+
+	t_bytes_align(&td->o, t);
 
 	if (t->action & BLK_TC_ACT(BLK_TC_NOTIFY))
-		handle_trace_notify(t);
+		return handle_trace_notify(t);
+	else if (t->action & BLK_TC_ACT(BLK_TC_DISCARD))
+		return handle_trace_discard(td, t, delay, ios, bs, cache);
+	else if (t->action & BLK_TC_ACT(BLK_TC_FLUSH))
+		return handle_trace_flush(td, t, delay, ios, cache);
 	else
-		handle_trace_fs(td, t, ttime, ios, bs);
+		return handle_trace_fs(td, t, delay, ios, bs, cache);
+}
+
+static void byteswap_trace(struct blk_io_trace *t)
+{
+	t->magic = fio_swap32(t->magic);
+	t->sequence = fio_swap32(t->sequence);
+	t->time = fio_swap64(t->time);
+	t->sector = fio_swap64(t->sector);
+	t->bytes = fio_swap32(t->bytes);
+	t->action = fio_swap32(t->action);
+	t->pid = fio_swap32(t->pid);
+	t->device = fio_swap32(t->device);
+	t->cpu = fio_swap32(t->cpu);
+	t->error = fio_swap16(t->error);
+	t->pdu_len = fio_swap16(t->pdu_len);
+}
+
+static bool t_is_write(struct blk_io_trace *t)
+{
+	return (t->action & BLK_TC_ACT(BLK_TC_WRITE | BLK_TC_DISCARD)) != 0;
+}
+
+static enum fio_ddir t_get_ddir(struct blk_io_trace *t)
+{
+	if (t->action & BLK_TC_ACT(BLK_TC_READ))
+		return DDIR_READ;
+	else if (t->action & BLK_TC_ACT(BLK_TC_WRITE))
+		return DDIR_WRITE;
+	else if (t->action & BLK_TC_ACT(BLK_TC_DISCARD))
+		return DDIR_TRIM;
+
+	return DDIR_INVAL;
+}
+
+static void depth_inc(struct blk_io_trace *t, int *depth)
+{
+	enum fio_ddir ddir;
+
+	ddir = t_get_ddir(t);
+	if (ddir != DDIR_INVAL)
+		depth[ddir]++;
+}
+
+static void depth_dec(struct blk_io_trace *t, int *depth)
+{
+	enum fio_ddir ddir;
+
+	ddir = t_get_ddir(t);
+	if (ddir != DDIR_INVAL)
+		depth[ddir]--;
+}
+
+static void depth_end(struct blk_io_trace *t, int *this_depth, int *depth)
+{
+	enum fio_ddir ddir = DDIR_INVAL;
+
+	ddir = t_get_ddir(t);
+	if (ddir != DDIR_INVAL) {
+		depth[ddir] = max(depth[ddir], this_depth[ddir]);
+		this_depth[ddir] = 0;
+	}
 }
 
 /*
  * 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)
+bool init_blktrace_read(struct thread_data *td, const char *filename, int need_swap)
 {
-	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;
+	int old_state;
 
-	fd = open(filename, O_RDONLY);
-	if (fd < 0) {
+	td->io_log_rfile = fopen(filename, "rb");
+	if (!td->io_log_rfile) {
 		td_verror(td, errno, "open blktrace file");
-		return 1;
+		goto err;
 	}
+	td->io_log_blktrace_swap = need_swap;
+	td->io_log_last_ttime = 0;
+	td->o.size = 0;
 
-	fifo = fifo_alloc(TRACE_FIFO_SIZE);
+	free_release_files(td);
 
-	td->o.size = 0;
+	old_state = td_bump_runstate(td, TD_SETTING_UP);
+
+	if (!read_blktrace(td)) {
+		goto err;
+	}
+
+	td_restore_runstate(td, old_state);
+
+	if (!td->files_index) {
+		log_err("fio: did not find replay device(s)\n");
+		return false;
+	}
+
+	return true;
+
+err:
+	if (td->io_log_rfile) {
+		fclose(td->io_log_rfile);
+		td->io_log_rfile = NULL;
+	}
+	return false;
+}
+
+bool read_blktrace(struct thread_data* td)
+{
+	struct blk_io_trace t;
+	struct file_cache cache = {
+		.maj = ~0U,
+		.min = ~0U,
+	};
+	unsigned long ios[DDIR_RWDIR_SYNC_CNT] = { };
+	unsigned long long rw_bs[DDIR_RWDIR_CNT] = { };
+	unsigned long skipped_writes;
+	FILE *f = td->io_log_rfile;
+	int i, max_depth;
+	struct fio_file *fiof;
+	int this_depth[DDIR_RWDIR_CNT] = { };
+	int depth[DDIR_RWDIR_CNT] = { };
+	int64_t items_to_fetch = 0;
+
+	if (td->o.read_iolog_chunked) {
+		items_to_fetch = iolog_items_to_fetch(td);
+		if (!items_to_fetch)
+			return true;
+	}
 
-	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));
+		int ret = fread(&t, 1, sizeof(t), f);
 
-		if (ret < 0)
+		if (ferror(f)) {
+			td_verror(td, errno, "read blktrace file");
 			goto err;
-		else if (!ret)
+		} else if (feof(f)) {
 			break;
-		else if (ret < (int) sizeof(t)) {
-			log_err("fio: short fifo get\n");
+		} else if (ret < (int) sizeof(t)) {
+			log_err("fio: iolog short read\n");
 			break;
 		}
 
+		if (td->io_log_blktrace_swap)
+			byteswap_trace(&t);
+
 		if ((t.magic & 0xffffff00) != BLK_IO_TRACE_MAGIC) {
 			log_err("fio: bad magic in blktrace data: %x\n",
 								t.magic);
@@ -322,67 +490,321 @@ int load_blktrace(struct thread_data *td, const char *filename)
 								t.magic & 0xff);
 			goto err;
 		}
-		ret = discard_pdu(td, fifo, fd, &t);
+		ret = discard_pdu(f, &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);
+			td_verror(td, -ret, "blktrace lseek");
 			goto err;
 		}
 		if ((t.action & BLK_TC_ACT(BLK_TC_NOTIFY)) == 0) {
-			if (!ttime) {
-				ttime = t.time;
-				cpu = t.cpu;
+			if ((t.action & 0xffff) == __BLK_TA_QUEUE)
+				depth_inc(&t, this_depth);
+			else if (((t.action & 0xffff) == __BLK_TA_BACKMERGE) ||
+				((t.action & 0xffff) == __BLK_TA_FRONTMERGE))
+				depth_dec(&t, this_depth);
+			else if ((t.action & 0xffff) == __BLK_TA_COMPLETE)
+				depth_end(&t, this_depth, depth);
+
+			if (t_is_write(&t) && read_only) {
+				skipped_writes++;
+				continue;
 			}
+		}
 
-			delay = 0;
-			if (cpu == t.cpu)
-				delay = t.time - ttime;
-			if ((t.action & BLK_TC_ACT(BLK_TC_WRITE)) && read_only)
-				skipped_writes++;
-			else
-				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);
+		if (!queue_trace(td, &t, ios, rw_bs, &cache))
+			continue;
+
+		if (td->o.read_iolog_chunked) {
+			td->io_log_current++;
+			items_to_fetch--;
+			if (items_to_fetch == 0)
+				break;
 		}
 	} while (1);
 
-	fifo_free(fifo);
-	close(fd);
+	if (td->o.read_iolog_chunked) {
+		td->io_log_highmark = td->io_log_current;
+		td->io_log_checkmark = (td->io_log_highmark + 1) / 2;
+		fio_gettime(&td->io_log_highmark_time, NULL);
+	}
 
 	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 {
+	if (td->o.read_iolog_chunked) {
+		if (td->io_log_current == 0) {
+			return false;
+		}
 		td->o.td_ddir = TD_DDIR_RW;
+		if ((rw_bs[DDIR_READ] > td->o.max_bs[DDIR_READ] ||
+		     rw_bs[DDIR_WRITE] > td->o.max_bs[DDIR_WRITE] ||
+		     rw_bs[DDIR_TRIM] > td->o.max_bs[DDIR_TRIM]) &&
+		    td->orig_buffer)
+		{
+			td->o.max_bs[DDIR_READ] = max(td->o.max_bs[DDIR_READ], rw_bs[DDIR_READ]);
+			td->o.max_bs[DDIR_WRITE] = max(td->o.max_bs[DDIR_WRITE], rw_bs[DDIR_WRITE]);
+			td->o.max_bs[DDIR_TRIM] = max(td->o.max_bs[DDIR_TRIM], rw_bs[DDIR_TRIM]);
+			io_u_quiesce(td);
+			free_io_mem(td);
+			if (init_io_u_buffers(td))
+				return false;
+		}
+		return true;
+	}
+
+	for_each_file(td, fiof, i)
+		trace_add_open_close_event(td, fiof->fileno, FIO_LOG_CLOSE_FILE);
+
+	fclose(td->io_log_rfile);
+	td->io_log_rfile = NULL;
+
+	/*
+	 * For stacked devices, we don't always get a COMPLETE event so
+	 * the depth grows to insane values. Limit it to something sane(r).
+	 */
+	max_depth = 0;
+	for (i = 0; i < DDIR_RWDIR_CNT; i++) {
+		if (depth[i] > 1024)
+			depth[i] = 1024;
+		else if (!depth[i] && ios[i])
+			depth[i] = 1;
+		max_depth = max(depth[i], max_depth);
+	}
+
+	if (!ios[DDIR_READ] && !ios[DDIR_WRITE] && !ios[DDIR_TRIM] &&
+	    !ios[DDIR_SYNC]) {
+		log_err("fio: found no ios in blktrace data\n");
+		return false;
+	}
+
+	td->o.td_ddir = 0;
+	if (ios[DDIR_READ]) {
+		td->o.td_ddir |= TD_DDIR_READ;
 		td->o.max_bs[DDIR_READ] = rw_bs[DDIR_READ];
+	}
+	if (ios[DDIR_WRITE]) {
+		td->o.td_ddir |= TD_DDIR_WRITE;
 		td->o.max_bs[DDIR_WRITE] = rw_bs[DDIR_WRITE];
 	}
+	if (ios[DDIR_TRIM]) {
+		td->o.td_ddir |= TD_DDIR_TRIM;
+		td->o.max_bs[DDIR_TRIM] = rw_bs[DDIR_TRIM];
+	}
 
 	/*
-	 * We need to do direct/raw ios to the device, to avoid getting
-	 * read-ahead in our way.
+	 * If depth wasn't manually set, use probed depth
 	 */
-	td->o.odirect = 1;
+	if (!fio_option_is_set(&td->o, iodepth))
+		td->o.iodepth = td->o.iodepth_low = max_depth;
 
-	return 0;
+	return true;
 err:
-	close(fd);
-	fifo_free(fifo);
-	return 1;
+	fclose(f);
+	return false;
+}
+
+static int init_merge_param_list(fio_fp64_t *vals, struct blktrace_cursor *bcs,
+				 int nr_logs, int def, size_t off)
+{
+	int i = 0, len = 0;
+
+	while (len < FIO_IO_U_LIST_MAX_LEN && vals[len].u.f != 0.0)
+		len++;
+
+	if (len && len != nr_logs)
+		return len;
+
+	for (i = 0; i < nr_logs; i++) {
+		int *val = (int *)((char *)&bcs[i] + off);
+		*val = def;
+		if (len)
+			*val = (int)vals[i].u.f;
+	}
+
+	return 0;
+
+}
+
+static int find_earliest_io(struct blktrace_cursor *bcs, int nr_logs)
+{
+	__u64 time = ~(__u64)0;
+	int idx = 0, i;
+
+	for (i = 0; i < nr_logs; i++) {
+		if (bcs[i].t.time < time) {
+			time = bcs[i].t.time;
+			idx = i;
+		}
+	}
+
+	return idx;
+}
+
+static void merge_finish_file(struct blktrace_cursor *bcs, int i, int *nr_logs)
+{
+	bcs[i].iter++;
+	if (bcs[i].iter < bcs[i].nr_iter) {
+		fseek(bcs[i].f, 0, SEEK_SET);
+		return;
+	}
+
+	*nr_logs -= 1;
+
+	/* close file */
+	fclose(bcs[i].f);
+
+	/* keep active files contiguous */
+	memmove(&bcs[i], &bcs[*nr_logs], sizeof(bcs[i]));
+}
+
+static int read_trace(struct thread_data *td, struct blktrace_cursor *bc)
+{
+	int ret = 0;
+	struct blk_io_trace *t = &bc->t;
+
+read_skip:
+	/* read an io trace */
+	ret = fread(&t, 1, sizeof(t), bc->f);
+	if (ferror(bc->f)) {
+		td_verror(td, errno, "read blktrace file");
+		return ret;
+	} else if (feof(bc->f)) {
+		if (!bc->length)
+			bc->length = bc->t.time;
+		return ret;
+	} else if (ret < (int) sizeof(*t)) {
+		log_err("fio: iolog short read\n");
+		return -1;
+	}
+
+	if (bc->swap)
+		byteswap_trace(t);
+
+	/* skip over actions that fio does not care about */
+	if ((t->action & 0xffff) != __BLK_TA_QUEUE ||
+	    t_get_ddir(t) == DDIR_INVAL) {
+		ret = discard_pdu(bc->f, t);
+		if (ret < 0) {
+			td_verror(td, -ret, "blktrace lseek");
+			return ret;
+		}
+		goto read_skip;
+	}
+
+	t->time = (t->time + bc->iter * bc->length) * bc->scalar / 100;
+
+	return ret;
+}
+
+static int write_trace(FILE *fp, struct blk_io_trace *t)
+{
+	/* pdu is not used so just write out only the io trace */
+	t->pdu_len = 0;
+	return fwrite((void *)t, sizeof(*t), 1, fp);
+}
+
+int merge_blktrace_iologs(struct thread_data *td)
+{
+	int nr_logs = get_max_str_idx(td->o.read_iolog_file);
+	struct blktrace_cursor *bcs = malloc(sizeof(struct blktrace_cursor) *
+					     nr_logs);
+	struct blktrace_cursor *bc;
+	FILE *merge_fp;
+	char *str, *ptr, *name, *merge_buf;
+	int i, ret;
+
+	ret = init_merge_param_list(td->o.merge_blktrace_scalars, bcs, nr_logs,
+				    100, offsetof(struct blktrace_cursor,
+						  scalar));
+	if (ret) {
+		log_err("fio: merge_blktrace_scalars(%d) != nr_logs(%d)\n",
+			ret, nr_logs);
+		goto err_param;
+	}
+
+	ret = init_merge_param_list(td->o.merge_blktrace_iters, bcs, nr_logs,
+				    1, offsetof(struct blktrace_cursor,
+						nr_iter));
+	if (ret) {
+		log_err("fio: merge_blktrace_iters(%d) != nr_logs(%d)\n",
+			ret, nr_logs);
+		goto err_param;
+	}
+
+	/* setup output file */
+	merge_fp = fopen(td->o.merge_blktrace_file, "w");
+	merge_buf = malloc(128 * 1024);
+	if (!merge_buf)
+		goto err_out_file;
+	ret = setvbuf(merge_fp, merge_buf, _IOFBF, 128 * 1024);
+	if (ret)
+		goto err_merge_buf;
+
+	/* setup input files */
+	str = ptr = strdup(td->o.read_iolog_file);
+	nr_logs = 0;
+	for (i = 0; (name = get_next_str(&ptr)) != NULL; i++) {
+		bcs[i].f = fopen(name, "rb");
+		if (!bcs[i].f) {
+			log_err("fio: could not open file: %s\n", name);
+			ret = -errno;
+			free(str);
+			goto err_file;
+		}
+		nr_logs++;
+
+		if (!is_blktrace(name, &bcs[i].swap)) {
+			log_err("fio: file is not a blktrace: %s\n", name);
+			free(str);
+			goto err_file;
+		}
+
+		ret = read_trace(td, &bcs[i]);
+		if (ret < 0) {
+			free(str);
+			goto err_file;
+		} else if (!ret) {
+			merge_finish_file(bcs, i, &nr_logs);
+			i--;
+		}
+	}
+	free(str);
+
+	/* merge files */
+	while (nr_logs) {
+		i = find_earliest_io(bcs, nr_logs);
+		bc = &bcs[i];
+		/* skip over the pdu */
+		ret = discard_pdu(bc->f, &bc->t);
+		if (ret < 0) {
+			td_verror(td, -ret, "blktrace lseek");
+			goto err_file;
+		}
+
+		ret = write_trace(merge_fp, &bc->t);
+		ret = read_trace(td, bc);
+		if (ret < 0)
+			goto err_file;
+		else if (!ret)
+			merge_finish_file(bcs, i, &nr_logs);
+	}
+
+	/* set iolog file to read from the newly merged file */
+	td->o.read_iolog_file = td->o.merge_blktrace_file;
+	ret = 0;
+
+err_file:
+	/* cleanup */
+	for (i = 0; i < nr_logs; i++) {
+		fclose(bcs[i].f);
+	}
+err_merge_buf:
+	free(merge_buf);
+err_out_file:
+	fflush(merge_fp);
+	fclose(merge_fp);
+err_param:
+	free(bcs);
+
+	return ret;
 }