commands/btrace/btrace.c
/* Block trace command line tool */
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/types.h>
#include <minix/btrace.h>
#include <minix/u64.h>
#include <sys/ioc_block.h>

static btrace_entry buf[BTBUF_SIZE];

static void usage(char *name)
{
  printf("usage:\n"
    "%s start <device> <nr_entries>\n"
    "%s stop <device> <file>\n"
    "%s reset <device>\n"
    "%s dump <file>\n",
    name, name, name, name);

  exit(EXIT_FAILURE);
}

static void btrace_start(char *device, int nr_entries)
{
  int r, ctl, devfd;
  size_t size;

  if ((devfd = open(device, O_RDONLY)) < 0) {
	perror("device open");
	exit(EXIT_FAILURE);
  }

  size = nr_entries;
  if ((r = ioctl(devfd, BIOCTRACEBUF, &size)) < 0) {
	perror("ioctl(BIOCTRACEBUF)");
	exit(EXIT_FAILURE);
  }

  ctl = BTCTL_START;
  if ((r = ioctl(devfd, BIOCTRACECTL, &ctl)) < 0) {
	perror("ioctl(BIOCTRACECTL)");

	size = 0;
	(void) ioctl(devfd, BIOCTRACEBUF, &size);

	exit(EXIT_FAILURE);
  }

  close(devfd);
}

static void btrace_stop(char *device, char *file)
{
  int r, ctl, devfd, outfd;
  size_t size;

  if ((devfd = open(device, O_RDONLY)) < 0) {
	perror("device open");
	exit(EXIT_FAILURE);
  }

  if ((outfd = open(file, O_CREAT|O_TRUNC|O_WRONLY, 0600)) < 0) {
	perror("file open");
	exit(EXIT_FAILURE);
  }

  ctl = BTCTL_STOP;
  if ((r = ioctl(devfd, BIOCTRACECTL, &ctl)) < 0) {
	perror("ioctl(BIOCTRACECTL)");
	exit(EXIT_FAILURE);
  }

  for (;;) {
	if ((r = ioctl(devfd, BIOCTRACEGET, buf)) < 0) {
		perror("ioctl(BIOCTRACEGET)");
		break;
	}

	if (r == 0) break;

	size = r * sizeof(buf[0]);
	if ((r = write(outfd, (char *) buf, size)) != size) {
		if (r < 0) perror("write");
		else fputs("short write\n", stderr);
	}
  }

  close(outfd);

  size = 0;
  if ((r = ioctl(devfd, BIOCTRACEBUF, &size)) < 0) {
	perror("ioctl(BIOCTRACEBUF)");
	exit(EXIT_FAILURE);
  }

  close(devfd);
}

static void btrace_reset(char *device)
{
  size_t size;
  int r, ctl, devfd;

  if ((devfd = open(device, O_RDONLY)) < 0) {
	perror("device open");
	exit(EXIT_FAILURE);
  }

  ctl = BTCTL_STOP;
  (void) ioctl(devfd, BIOCTRACECTL, &ctl);

  size = 0;
  if ((r = ioctl(devfd, BIOCTRACEBUF, &size)) < 0) {
	perror("ioctl(BIOCTRACEBUF)");
	exit(EXIT_FAILURE);
  }

  close(devfd);
}

static void dump_entry(btrace_entry *entry)
{
  switch (entry->request) {
  case BTREQ_OPEN: printf("OPEN"); break;
  case BTREQ_CLOSE: printf("CLOSE"); break;
  case BTREQ_READ: printf("READ"); break;
  case BTREQ_WRITE: printf("WRITE"); break;
  case BTREQ_GATHER: printf("GATHER"); break;
  case BTREQ_SCATTER: printf("SCATTER"); break;
  case BTREQ_IOCTL: printf("IOCTL"); break;
  }

  printf(" request\n");

  switch (entry->request) {
  case BTREQ_OPEN:
	printf("- access:\t%x\n", entry->size);
	break;
  case BTREQ_READ:
  case BTREQ_WRITE:
  case BTREQ_GATHER:
  case BTREQ_SCATTER:
	printf("- position:\t%08lx%08lx\n",
		ex64hi(entry->position), ex64lo(entry->position));
	printf("- size:\t\t%u\n", entry->size);
	printf("- flags:\t%x\n", entry->flags);
	break;
  case BTREQ_IOCTL:
	printf("- request:\t%08x\n", entry->size);
	break;
  }

  printf("- start:\t%u us\n", entry->start_time);
  printf("- finish:\t%u us\n", entry->finish_time);
  if (entry->result == BTRES_INPROGRESS)
	printf("- result:\t(in progress)\n");
  else
	printf("- result:\t%d\n", entry->result);
  printf("\n");
}

static void btrace_dump(char *file)
{
  int i, r, infd;

  if ((infd = open(file, O_RDONLY)) < 0) {
	perror("open");
	exit(EXIT_FAILURE);
  }

  for (;;) {
	if ((r = read(infd, (char *) buf, sizeof(buf))) <= 0)
		break;

	r /= sizeof(buf[0]);

	for (i = 0; i < r; i++)
		dump_entry(&buf[i]);
  }

  if (r < 0) perror("read");

  close(infd);
}

int main(int argc, char **argv)
{
  int num;
  char *name = argv[0];

  if (argc < 3) usage(name);

  if (!strcmp(argv[1], "start")) {
	if (argc < 4) usage(name);

	num = atoi(argv[3]);

	if (num <= 0) usage(name);

	btrace_start(argv[2], num);
  }
  else if (!strcmp(argv[1], "stop")) {
	if (argc < 4) usage(name);

	btrace_stop(argv[2], argv[3]);
  }
  else if (!strcmp(argv[1], "reset")) {
	btrace_reset(argv[2]);
  }
  else if (!strcmp(argv[1], "dump")) {
	btrace_dump(argv[2]);
  }
  else usage(name);

  return EXIT_SUCCESS;
}
