blob: cdbfea02edcdcfe03fbf77cdd7a6f79c0399b433 [file] [log] [blame]
/*
* 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 65536
/*
* 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(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 (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_event(struct thread_data *td, int fileno)
{
struct io_piece *ipo;
ipo = calloc(1, sizeof(*ipo));
ipo->ddir = DDIR_INVAL;
ipo->fileno = fileno;
ipo->file_action = FIO_LOG_OPEN_FILE;
flist_add_tail(&ipo->list, &td->io_log_list);
}
static void trace_add_file(struct thread_data *td, __u32 device)
{
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;
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)
return;
strcpy(dev, "/dev");
if (lookup_device(dev, maj, min)) {
int fileno;
dprint(FD_BLKTRACE, "add devices %s\n", dev);
fileno = add_file(td, dev);
trace_add_open_event(td, 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)
{
struct io_piece *ipo = malloc(sizeof(*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;
ipo->len = bytes;
ipo->delay = ttime / 1000;
if (rw)
ipo->ddir = DDIR_WRITE;
else
ipo->ddir = DDIR_READ;
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;
default:
dprint(FD_BLKTRACE, "unknown trace act %x\n", t->action);
break;
}
}
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;
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);
}
/*
* 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
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;
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
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);
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;
}