/*
* 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"
#include "lib/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);
}
/*
* 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, int *need_swap)
{
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) {
*need_swap = 0;
return 1;
}
/*
* 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 1;
}
return 0;
}
#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 (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);
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);
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:
dprint(FD_BLKTRACE, "got process notify: %x, %d\n",
t->action, t->pid);
break;
case BLK_TN_TIMESTAMP:
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;
}
}
static void handle_trace_discard(struct thread_data *td,
struct blk_io_trace *t,
unsigned long long ttime,
unsigned long *ios, unsigned int *bs)
{
struct io_piece *ipo = malloc(sizeof(*ipo));
int fileno;
init_ipo(ipo);
fileno = trace_add_file(td, t->device);
ios[DDIR_TRIM]++;
if (t->bytes > bs[DDIR_TRIM])
bs[DDIR_TRIM] = t->bytes;
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 *ios, unsigned int *bs)
{
static unsigned long long last_ttime;
unsigned long long delay;
if ((t->action & 0xffff) != __BLK_TA_QUEUE)
return;
if (!(t->action & BLK_TC_ACT(BLK_TC_NOTIFY))) {
if (!last_ttime || td->o.no_stall) {
last_ttime = t->time;
delay = 0;
} else {
delay = t->time - last_ttime;
last_ttime = t->time;
}
}
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, delay, ios, bs);
else
handle_trace_fs(td, t, delay, ios, bs);
}
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 int t_is_write(struct blk_io_trace *t)
{
return (t->action & BLK_TC_ACT(BLK_TC_WRITE | BLK_TC_DISCARD)) != 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, int need_swap)
{
struct blk_io_trace t;
unsigned long ios[DDIR_RWDIR_CNT], skipped_writes;
unsigned int rw_bs[DDIR_RWDIR_CNT];
struct fifo *fifo;
int fd, i, old_state;
struct fio_file *f;
int this_depth, depth;
fd = open(filename, O_RDONLY);
if (fd < 0) {
td_verror(td, errno, "open blktrace file");
return 1;
}
fifo = fifo_alloc(TRACE_FIFO_SIZE);
old_state = td_bump_runstate(td, TD_SETTING_UP);
td->o.size = 0;
ios[0] = ios[1] = 0;
rw_bs[0] = rw_bs[1] = 0;
skipped_writes = 0;
this_depth = depth = 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 (need_swap)
byteswap_trace(&t);
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 ((t.action & 0xffff) == __BLK_TA_QUEUE)
this_depth++;
else if ((t.action & 0xffff) == __BLK_TA_COMPLETE) {
depth = max(depth, this_depth);
this_depth = 0;
}
if (t_is_write(&t) && read_only) {
skipped_writes++;
continue;
}
}
handle_trace(td, &t, 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);
td_restore_runstate(td, old_state);
if (!td->files_index) {
log_err("fio: did not find replay device(s)\n");
return 1;
}
/*
* For stacked devices, we don't always get a COMPLETE event so
* the depth grows to insane values. Limit it to something sane(r).
*/
if (!depth || depth > 1024)
depth = 1024;
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_WRITE]) {
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];
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.
*/
td->o.odirect = 1;
/*
* we don't know if this option was set or not. it defaults to 1,
* so we'll just guess that we should override it if it's still 1
*/
if (td->o.iodepth == 1)
td->o.iodepth = td->o.iodepth_low = depth;
return 0;
err:
close(fd);
fifo_free(fifo);
return 1;
}