blktrace.c

   1 /*
   2  * block queue tracing application
   3  *
   4  * Copyright (C) 2005 Jens Axboe <axboe@suse.de>
   5  *
   6  *  This program is free software; you can redistribute it and/or modify
   7  *  it under the terms of the GNU General Public License as published by
   8  *  the Free Software Foundation; either version 2 of the License, or
   9  *  (at your option) any later version.
  10  *
  11  *  This program is distributed in the hope that it will be useful,
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *  GNU General Public License for more details.
  15  *
  16  *  You should have received a copy of the GNU General Public License
  17  *  along with this program; if not, write to the Free Software
  18  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19  *
  20  */
  21 #include <pthread.h>
  22 #include <sys/types.h>
  23 #include <sys/stat.h>
  24 #include <unistd.h>
  25 #include <locale.h>
  26 #include <signal.h>
  27 #include <fcntl.h>
  28 #include <string.h>
  29 #include <sys/ioctl.h>
  30 #include <sys/param.h>
  31 #include <sys/statfs.h>
  32 #include <sys/poll.h>
  33 #include <stdio.h>
  34 #include <stdlib.h>
  35 #include <sched.h>
  36 #include <ctype.h>
  37 #include <getopt.h>
  38 #include <errno.h>
  39 #include <assert.h>
  40
  41 #include "blktrace.h"
  42 #include "barrier.h"
  43
  44 static char blktrace_version[] = "0.99";
  45
  46 /*
  47  * You may want to increase this even more, if you are logging at a high
  48  * rate and see skipped/missed events
  49  */
  50 #define BUF_SIZE        (512 * 1024)
  51 #define BUF_NR          (4)
  52
  53 #define OFILE_BUF       (128 * 1024)
  54
  55 #define RELAYFS_TYPE    0xF0B4A981
  56
  57 #define RING_INIT_NR    (2)
  58 #define RING_MAX_NR     (16UL)
  59
  60 #define S_OPTS  "d:a:A:r:o:kw:Vb:n:D:"
  61 static struct option l_opts[] = {
  62         {
  63                 .name = "dev",
  64                 .has_arg = required_argument,
  65                 .flag = NULL,
  66                 .val = 'd'
  67         },
  68         {
  69                 .name = "act-mask",
  70                 .has_arg = required_argument,
  71                 .flag = NULL,
  72                 .val = 'a'
  73         },
  74         {
  75                 .name = "set-mask",
  76                 .has_arg = required_argument,
  77                 .flag = NULL,
  78                 .val = 'A'
  79         },
  80         {
  81                 .name = "relay",
  82                 .has_arg = required_argument,
  83                 .flag = NULL,
  84                 .val = 'r'
  85         },
  86         {
  87                 .name = "output",
  88                 .has_arg = required_argument,
  89                 .flag = NULL,
  90                 .val = 'o'
  91         },
  92         {
  93                 .name = "kill",
  94                 .has_arg = no_argument,
  95                 .flag = NULL,
  96                 .val = 'k'
  97         },
  98         {
  99                 .name = "stopwatch",
 100                 .has_arg = required_argument,
 101                 .flag = NULL,
 102                 .val = 'w'
 103         },
 104         {
 105                 .name = "version",
 106                 .has_arg = no_argument,
 107                 .flag = NULL,
 108                 .val = 'V'
 109         },
 110         {
 111                 .name = "buffer-size",
 112                 .has_arg = required_argument,
 113                 .flag = NULL,
 114                 .val = 'b'
 115         },
 116         {
 117                 .name = "num-sub-buffers",
 118                 .has_arg = required_argument,
 119                 .flag = NULL,
 120                 .val = 'n'
 121         },
 122         {
 123                 .name = "output-dir",
 124                 .has_arg = required_argument,
 125                 .flag = NULL,
 126                 .val = 'D'
 127         },
 128         {
 129                 .name = NULL,
 130         }
 131 };
 132
 133 struct tip_subbuf {
 134         void *buf;
 135         unsigned int len;
 136         unsigned int max_len;
 137 };
 138
 139 #define FIFO_SIZE       (1024)  /* should be plenty big! */
 140 #define CL_SIZE         (128)   /* cache line, any bigger? */
 141
 142 struct tip_subbuf_fifo {
 143         int tail __attribute__((aligned(CL_SIZE)));
 144         int head __attribute__((aligned(CL_SIZE)));
 145         struct tip_subbuf *q[FIFO_SIZE];
 146 };
 147
 148 struct thread_information {
 149         int cpu;
 150         pthread_t thread;
 151
 152         int fd;
 153         void *fd_buf;
 154         unsigned long fd_off;
 155         unsigned long fd_size;
 156         unsigned long fd_max_size;
 157         char fn[MAXPATHLEN + 64];
 158
 159         FILE *ofile;
 160         char *ofile_buffer;
 161         int ofile_stdout;
 162
 163         unsigned long events_processed;
 164         struct device_information *device;
 165
 166         int exited;
 167
 168         struct tip_subbuf_fifo fifo;
 169         struct tip_subbuf *leftover_ts;
 170 };
 171
 172 struct device_information {
 173         int fd;
 174         char *path;
 175         char buts_name[32];
 176         volatile int trace_started;
 177         unsigned long drop_count;
 178         struct thread_information *threads;
 179 };
 180
 181 static int ncpus;
 182 static struct thread_information *thread_information;
 183 static int ndevs;
 184 static struct device_information *device_information;
 185
 186 /* command line option globals */
 187 static char *relay_path;
 188 static char *output_name;
 189 static char *output_dir;
 190 static int act_mask = ~0U;
 191 static int kill_running_trace;
 192 static unsigned long buf_size = BUF_SIZE;
 193 static unsigned long buf_nr = BUF_NR;
 194
 195 #define is_done()       (*(volatile int *)(&done))
 196 static volatile int done;
 197
 198 #define is_trace_stopped()      (*(volatile int *)(&trace_stopped))
 199 static volatile int trace_stopped;
 200
 201 #define is_stat_shown() (*(volatile int *)(&stat_shown))
 202 static volatile int stat_shown;
 203
 204 static void exit_trace(int status);
 205
 206 #define dip_tracing(dip)        (*(volatile int *)(&(dip)->trace_started))
 207 #define dip_set_tracing(dip, v) ((dip)->trace_started = (v))
 208
 209 #define __for_each_dip(__d, __i, __e)   \
 210         for (__i = 0, __d = device_information; __i < __e; __i++, __d++)
 211
 212 #define for_each_dip(__d, __i)  __for_each_dip(__d, __i, ndevs)
 213 #define for_each_tip(__d, __t, __j)     \
 214         for (__j = 0, __t = (__d)->threads; __j < ncpus; __j++, __t++)
 215
 216 static int get_dropped_count(const char *buts_name)
 217 {
 218         int fd;
 219         char tmp[MAXPATHLEN + 64];
 220
 221         snprintf(tmp, sizeof(tmp), "%s/block/%s/dropped",
 222                  relay_path, buts_name);
 223
 224         fd = open(tmp, O_RDONLY);
 225         if (fd < 0) {
 226                 /*
 227                  * this may be ok, if the kernel doesn't support dropped counts
 228                  */
 229                 if (errno == ENOENT)
 230                         return 0;
 231
 232                 fprintf(stderr, "Couldn't open dropped file %s\n", tmp);
 233                 return -1;
 234         }
 235
 236         if (read(fd, tmp, sizeof(tmp)) < 0) {
 237                 perror(tmp);
 238                 close(fd);
 239                 return -1;
 240         }
 241
 242         close(fd);
 243
 244         return atoi(tmp);
 245 }
 246
 247 static int start_trace(struct device_information *dip)
 248 {
 249         struct blk_user_trace_setup buts;
 250
 251         memset(&buts, 0, sizeof(buts));
 252         buts.buf_size = buf_size;
 253         buts.buf_nr = buf_nr;
 254         buts.act_mask = act_mask;
 255
 256         if (ioctl(dip->fd, BLKSTARTTRACE, &buts) < 0) {
 257                 perror("BLKSTARTTRACE");
 258                 return 1;
 259         }
 260
 261         memcpy(dip->buts_name, buts.name, sizeof(dip->buts_name));
 262         dip_set_tracing(dip, 1);
 263         return 0;
 264 }
 265
 266 static void stop_trace(struct device_information *dip)
 267 {
 268         if (dip_tracing(dip) || kill_running_trace) {
 269                 dip_set_tracing(dip, 0);
 270
 271                 if (ioctl(dip->fd, BLKSTOPTRACE) < 0)
 272                         perror("BLKSTOPTRACE");
 273
 274                 close(dip->fd);
 275                 dip->fd = -1;
 276         }
 277 }
 278
 279 static void stop_all_traces(void)
 280 {
 281         struct device_information *dip;
 282         int i;
 283
 284         for_each_dip(dip, i) {
 285                 dip->drop_count = get_dropped_count(dip->buts_name);
 286                 stop_trace(dip);
 287         }
 288 }
 289
 290 static void wait_for_data(struct thread_information *tip)
 291 {
 292         struct pollfd pfd = { .fd = tip->fd, .events = POLLIN };
 293
 294         do {
 295                 poll(&pfd, 1, 100);
 296                 if (pfd.revents & POLLIN)
 297                         break;
 298                 if (tip->ofile_stdout)
 299                         break;
 300         } while (!is_done());
 301 }
 302
 303 static int read_data(struct thread_information *tip, void *buf, int len)
 304 {
 305         int ret = 0;
 306
 307         do {
 308                 wait_for_data(tip);
 309
 310                 ret = read(tip->fd, buf, len);
 311                 if (!ret)
 312                         continue;
 313                 else if (ret > 0)
 314                         return ret;
 315                 else {
 316                         if (errno != EAGAIN) {
 317                                 perror(tip->fn);
 318                                 fprintf(stderr,"Thread %d failed read of %s\n",
 319                                         tip->cpu, tip->fn);
 320                                 break;
 321                         }
 322                         continue;
 323                 }
 324         } while (!is_done());
 325
 326         return ret;
 327 }
 328
 329 static inline struct tip_subbuf *subbuf_fifo_dequeue(struct thread_information *tip)
 330 {
 331         const int head = tip->fifo.head;
 332         const int next = (head + 1) & (FIFO_SIZE - 1);
 333
 334         if (head != tip->fifo.tail) {
 335                 struct tip_subbuf *ts = tip->fifo.q[head];
 336
 337                 store_barrier();
 338                 tip->fifo.head = next;
 339                 return ts;
 340         }
 341
 342         return NULL;
 343 }
 344
 345 static inline int subbuf_fifo_queue(struct thread_information *tip,
 346                                     struct tip_subbuf *ts)
 347 {
 348         const int tail = tip->fifo.tail;
 349         const int next = (tail + 1) & (FIFO_SIZE - 1);
 350
 351         if (next != tip->fifo.head) {
 352                 tip->fifo.q[tail] = ts;
 353                 store_barrier();
 354                 tip->fifo.tail = next;
 355                 return 0;
 356         }
 357
 358         fprintf(stderr, "fifo too small!\n");
 359         return 1;
 360 }
 361
 362 static int get_subbuf(struct thread_information *tip)
 363 {
 364         struct tip_subbuf *ts;
 365         int ret;
 366
 367         ts = malloc(sizeof(*ts));
 368         ts->buf = malloc(buf_size);
 369         ts->max_len = buf_size;
 370
 371         ret = read_data(tip, ts->buf, ts->max_len);
 372         if (ret > 0) {
 373                 ts->len = ret;
 374                 return subbuf_fifo_queue(tip, ts);
 375         }
 376
 377         free(ts->buf);
 378         free(ts);
 379         return -1;
 380 }
 381
 382 static void close_thread(struct thread_information *tip)
 383 {
 384         if (tip->fd != -1)
 385                 close(tip->fd);
 386         if (tip->ofile)
 387                 fclose(tip->ofile);
 388         if (tip->ofile_buffer)
 389                 free(tip->ofile_buffer);
 390         if (tip->fd_buf)
 391                 free(tip->fd_buf);
 392
 393         tip->fd = -1;
 394         tip->ofile = NULL;
 395         tip->ofile_buffer = NULL;
 396         tip->fd_buf = NULL;
 397 }
 398
 399 static void *thread_main(void *arg)
 400 {
 401         struct thread_information *tip = arg;
 402         pid_t pid = getpid();
 403         cpu_set_t cpu_mask;
 404
 405         CPU_ZERO(&cpu_mask);
 406         CPU_SET((tip->cpu), &cpu_mask);
 407
 408         if (sched_setaffinity(pid, sizeof(cpu_mask), &cpu_mask) == -1) {
 409                 perror("sched_setaffinity");
 410                 exit_trace(1);
 411         }
 412
 413         snprintf(tip->fn, sizeof(tip->fn), "%s/block/%s/trace%d",
 414                         relay_path, tip->device->buts_name, tip->cpu);
 415         tip->fd = open(tip->fn, O_RDONLY);
 416         if (tip->fd < 0) {
 417                 perror(tip->fn);
 418                 fprintf(stderr,"Thread %d failed open of %s\n", tip->cpu,
 419                         tip->fn);
 420                 exit_trace(1);
 421         }
 422
 423         for (;;) {
 424                 if (get_subbuf(tip))
 425                         break;
 426         }
 427
 428         tip->exited = 1;
 429         return NULL;
 430 }
 431
 432 static int write_data(struct thread_information *tip,
 433                       void *buf, unsigned int buf_len)
 434 {
 435         int ret;
 436
 437         if (!buf_len)
 438                 return 0;
 439
 440         while (1) {
 441                 ret = fwrite(buf, buf_len, 1, tip->ofile);
 442                 if (ret == 1)
 443                         break;
 444
 445                 if (ret < 0) {
 446                         perror("write");
 447                         return 1;
 448                 }
 449         }
 450
 451         if (tip->ofile_stdout)
 452                 fflush(tip->ofile);
 453
 454         return 0;
 455 }
 456
 457 static int flush_subbuf(struct thread_information *tip, struct tip_subbuf *ts)
 458 {
 459         unsigned int offset = 0;
 460         struct blk_io_trace *t;
 461         int pdu_len, events = 0;
 462
 463         /*
 464          * surplus from last run
 465          */
 466         if (tip->leftover_ts) {
 467                 struct tip_subbuf *prev_ts = tip->leftover_ts;
 468
 469                 if (prev_ts->len + ts->len > prev_ts->max_len) {
 470                         prev_ts->max_len += ts->len;
 471                         prev_ts->buf = realloc(prev_ts->buf, prev_ts->max_len);
 472                 }
 473
 474                 memcpy(prev_ts->buf + prev_ts->len, ts->buf, ts->len);
 475                 prev_ts->len += ts->len;
 476
 477                 free(ts->buf);
 478                 free(ts);
 479
 480                 ts = prev_ts;
 481                 tip->leftover_ts = NULL;
 482         }
 483
 484         while (offset + sizeof(*t) <= ts->len) {
 485                 t = ts->buf + offset;
 486
 487                 if (verify_trace(t)) {
 488                         write_data(tip, ts->buf, offset);
 489                         return -1;
 490                 }
 491
 492                 pdu_len = t->pdu_len;
 493
 494                 if (offset + sizeof(*t) + pdu_len > ts->len)
 495                         break;
 496
 497                 offset += sizeof(*t) + pdu_len;
 498                 tip->events_processed++;
 499                 events++;
 500         }
 501
 502         if (write_data(tip, ts->buf, offset))
 503                 return -1;
 504
 505         /*
 506          * leftover bytes, save them for next time
 507          */
 508         if (offset != ts->len) {
 509                 tip->leftover_ts = ts;
 510                 ts->len -= offset;
 511                 memmove(ts->buf, ts->buf + offset, ts->len);
 512         } else {
 513                 free(ts->buf);
 514                 free(ts);
 515         }
 516
 517         return events;
 518 }
 519
 520 static int write_tip_events(struct thread_information *tip)
 521 {
 522         struct tip_subbuf *ts = subbuf_fifo_dequeue(tip);
 523
 524         if (ts)
 525                 return flush_subbuf(tip, ts);
 526
 527         return 0;
 528 }
 529
 530 /*
 531  * scans the tips we know and writes out the subbuffers we accumulate
 532  */
 533 static void get_and_write_events(void)
 534 {
 535         struct device_information *dip;
 536         struct thread_information *tip;
 537         int i, j, events, ret, tips_running;
 538
 539         while (!is_done()) {
 540                 events = 0;
 541
 542                 for_each_dip(dip, i) {
 543                         for_each_tip(dip, tip, j) {
 544                                 ret = write_tip_events(tip);
 545                                 if (ret > 0)
 546                                         events += ret;
 547                         }
 548                 }
 549
 550                 if (!events)
 551                         usleep(10);
 552         }
 553
 554         /*
 555          * reap stored events
 556          */
 557         do {
 558                 events = 0;
 559                 tips_running = 0;
 560                 for_each_dip(dip, i) {
 561                         for_each_tip(dip, tip, j) {
 562                                 ret = write_tip_events(tip);
 563                                 if (ret > 0)
 564                                         events += ret;
 565                                 tips_running += !tip->exited;
 566                         }
 567                 }
 568                 usleep(10);
 569         } while (events || tips_running);
 570 }
 571
 572 static int start_threads(struct device_information *dip)
 573 {
 574         struct thread_information *tip;
 575         char op[64];
 576         int j, pipeline = output_name && !strcmp(output_name, "-");
 577         int len, mode, vbuf_size;
 578
 579         for_each_tip(dip, tip, j) {
 580                 tip->cpu = j;
 581                 tip->device = dip;
 582                 tip->events_processed = 0;
 583                 memset(&tip->fifo, 0, sizeof(tip->fifo));
 584                 tip->leftover_ts = NULL;
 585
 586                 if (pipeline) {
 587                         tip->ofile = fdopen(STDOUT_FILENO, "w");
 588                         tip->ofile_stdout = 1;
 589                         mode = _IOLBF;
 590                         vbuf_size = 512;
 591                 } else {
 592                         len = 0;
 593
 594                         if (output_dir)
 595                                 len = sprintf(op, "%s/", output_dir);
 596
 597                         if (output_name) {
 598                                 sprintf(op + len, "%s.blktrace.%d", output_name,
 599                                         tip->cpu);
 600                         } else {
 601                                 sprintf(op + len, "%s.blktrace.%d",
 602                                         dip->buts_name, tip->cpu);
 603                         }
 604                         tip->ofile = fopen(op, "w");
 605                         tip->ofile_stdout = 0;
 606                         mode = _IOFBF;
 607                         vbuf_size = OFILE_BUF;
 608                 }
 609
 610                 if (tip->ofile == NULL) {
 611                         perror(op);
 612                         return 1;
 613                 }
 614
 615                 tip->ofile_buffer = malloc(vbuf_size);
 616                 if (setvbuf(tip->ofile, tip->ofile_buffer, mode, vbuf_size)) {
 617                         perror("setvbuf");
 618                         close_thread(tip);
 619                         return 1;
 620                 }
 621
 622                 if (pthread_create(&tip->thread, NULL, thread_main, tip)) {
 623                         perror("pthread_create");
 624                         close_thread(tip);
 625                         return 1;
 626                 }
 627         }
 628
 629         return 0;
 630 }
 631
 632 static void stop_threads(struct device_information *dip)
 633 {
 634         struct thread_information *tip;
 635         unsigned long ret;
 636         int i;
 637
 638         for_each_tip(dip, tip, i) {
 639                 (void) pthread_join(tip->thread, (void *) &ret);
 640                 close_thread(tip);
 641         }
 642 }
 643
 644 static void stop_all_threads(void)
 645 {
 646         struct device_information *dip;
 647         int i;
 648
 649         for_each_dip(dip, i)
 650                 stop_threads(dip);
 651 }
 652
 653 static void stop_all_tracing(void)
 654 {
 655         struct device_information *dip;
 656         int i;
 657
 658         for_each_dip(dip, i)
 659                 stop_trace(dip);
 660 }
 661
 662 static void exit_trace(int status)
 663 {
 664         if (!is_trace_stopped()) {
 665                 trace_stopped = 1;
 666                 stop_all_threads();
 667                 stop_all_tracing();
 668         }
 669
 670         exit(status);
 671 }
 672
 673 static int resize_devices(char *path)
 674 {
 675         int size = (ndevs + 1) * sizeof(struct device_information);
 676
 677         device_information = realloc(device_information, size);
 678         if (!device_information) {
 679                 fprintf(stderr, "Out of memory, device %s (%d)\n", path, size);
 680                 return 1;
 681         }
 682         device_information[ndevs].path = path;
 683         ndevs++;
 684         return 0;
 685 }
 686
 687 static int open_devices(void)
 688 {
 689         struct device_information *dip;
 690         int i;
 691
 692         for_each_dip(dip, i) {
 693                 dip->fd = open(dip->path, O_RDONLY | O_NONBLOCK);
 694                 if (dip->fd < 0) {
 695                         perror(dip->path);
 696                         return 1;
 697                 }
 698         }
 699
 700         return 0;
 701 }
 702
 703 static int start_devices(void)
 704 {
 705         struct device_information *dip;
 706         int i, j, size;
 707
 708         size = ncpus * sizeof(struct thread_information);
 709         thread_information = malloc(size * ndevs);
 710         if (!thread_information) {
 711                 fprintf(stderr, "Out of memory, threads (%d)\n", size * ndevs);
 712                 return 1;
 713         }
 714
 715         for_each_dip(dip, i) {
 716                 if (start_trace(dip)) {
 717                         close(dip->fd);
 718                         fprintf(stderr, "Failed to start trace on %s\n",
 719                                 dip->path);
 720                         break;
 721                 }
 722         }
 723
 724         if (i != ndevs) {
 725                 __for_each_dip(dip, j, i)
 726                         stop_trace(dip);
 727
 728                 return 1;
 729         }
 730
 731         for_each_dip(dip, i) {
 732                 dip->threads = thread_information + (i * ncpus);
 733                 if (start_threads(dip)) {
 734                         fprintf(stderr, "Failed to start worker threads\n");
 735                         break;
 736                 }
 737         }
 738
 739         if (i != ndevs) {
 740                 __for_each_dip(dip, j, i)
 741                         stop_threads(dip);
 742                 for_each_dip(dip, i)
 743                         stop_trace(dip);
 744
 745                 return 1;
 746         }
 747
 748         return 0;
 749 }
 750
 751 static void show_stats(void)
 752 {
 753         struct device_information *dip;
 754         struct thread_information *tip;
 755         unsigned long long events_processed;
 756         unsigned long total_drops;
 757         int i, j, no_stdout = 0;
 758
 759         if (is_stat_shown())
 760                 return;
 761
 762         if (output_name && !strcmp(output_name, "-"))
 763                 no_stdout = 1;
 764
 765         stat_shown = 1;
 766
 767         total_drops = 0;
 768         for_each_dip(dip, i) {
 769                 if (!no_stdout)
 770                         printf("Device: %s\n", dip->path);
 771                 events_processed = 0;
 772                 for_each_tip(dip, tip, j) {
 773                         if (!no_stdout)
 774                                 printf("  CPU%3d: %20ld events\n",
 775                                         tip->cpu, tip->events_processed);
 776                         events_processed += tip->events_processed;
 777                 }
 778                 total_drops += dip->drop_count;
 779                 if (!no_stdout)
 780                         printf("  Total:  %20lld events (dropped %lu)\n",
 781                                         events_processed, dip->drop_count);
 782         }
 783
 784         if (total_drops)
 785                 fprintf(stderr, "You have dropped events, consider using a larger buffer size (-b)\n");
 786 }
 787
 788 static char usage_str[] = \
 789         "-d <dev> [ -r relay path ] [ -o <output> ] [-k ] [ -w time ]\n" \
 790         "[ -a action ] [ -A action mask ] [ -v ]\n\n" \
 791         "\t-d Use specified device. May also be given last after options\n" \
 792         "\t-r Path to mounted relayfs, defaults to /relay\n" \
 793         "\t-o File(s) to send output to\n" \
 794         "\t-D Directory to prepend to output file names\n" \
 795         "\t-k Kill a running trace\n" \
 796         "\t-w Stop after defined time, in seconds\n" \
 797         "\t-a Only trace specified actions. See documentation\n" \
 798         "\t-A Give trace mask as a single value. See documentation\n" \
 799         "\t-b Sub buffer size in KiB\n" \
 800         "\t-n Number of sub buffers\n" \
 801         "\t-v Print program version info\n\n";
 802
 803 static void show_usage(char *program)
 804 {
 805         fprintf(stderr, "Usage: %s %s %s",program, blktrace_version, usage_str);
 806 }
 807 static void handle_sigint(__attribute__((__unused__)) int sig)
 808 {
 809         done = 1;
 810 }
 811
 812 int main(int argc, char *argv[])
 813 {
 814         static char default_relay_path[] = "/relay";
 815         struct statfs st;
 816         int i, c;
 817         int stop_watch = 0;
 818         int act_mask_tmp = 0;
 819
 820         while ((c = getopt_long(argc, argv, S_OPTS, l_opts, NULL)) >= 0) {
 821                 switch (c) {
 822                 case 'a':
 823                         i = find_mask_map(optarg);
 824                         if (i < 0) {
 825                                 fprintf(stderr,"Invalid action mask %s\n",
 826                                         optarg);
 827                                 return 1;
 828                         }
 829                         act_mask_tmp |= i;
 830                         break;
 831
 832                 case 'A':
 833                         if ((sscanf(optarg, "%x", &i) != 1) ||
 834                                                         !valid_act_opt(i)) {
 835                                 fprintf(stderr,
 836                                         "Invalid set action mask %s/0x%x\n",
 837                                         optarg, i);
 838                                 return 1;
 839                         }
 840                         act_mask_tmp = i;
 841                         break;
 842
 843                 case 'd':
 844                         if (resize_devices(optarg) != 0)
 845                                 return 1;
 846                         break;
 847
 848                 case 'r':
 849                         relay_path = optarg;
 850                         break;
 851
 852                 case 'o':
 853                         output_name = optarg;
 854                         break;
 855                 case 'k':
 856                         kill_running_trace = 1;
 857                         break;
 858                 case 'w':
 859                         stop_watch = atoi(optarg);
 860                         if (stop_watch <= 0) {
 861                                 fprintf(stderr,
 862                                         "Invalid stopwatch value (%d secs)\n",
 863                                         stop_watch);
 864                                 return 1;
 865                         }
 866                         break;
 867                 case 'V':
 868                         printf("%s version %s\n", argv[0], blktrace_version);
 869                         return 0;
 870                 case 'b':
 871                         buf_size = strtoul(optarg, NULL, 10);
 872                         if (buf_size <= 0 || buf_size > 16*1024) {
 873                                 fprintf(stderr,
 874                                         "Invalid buffer size (%lu)\n",buf_size);
 875                                 return 1;
 876                         }
 877                         buf_size <<= 10;
 878                         break;
 879                 case 'n':
 880                         buf_nr = strtoul(optarg, NULL, 10);
 881                         if (buf_nr <= 0) {
 882                                 fprintf(stderr,
 883                                         "Invalid buffer nr (%lu)\n", buf_nr);
 884                                 return 1;
 885                         }
 886                         break;
 887                 case 'D':
 888                         output_dir = optarg;
 889                         break;
 890                 default:
 891                         show_usage(argv[0]);
 892                         return 1;
 893                 }
 894         }
 895
 896         while (optind < argc) {
 897                 if (resize_devices(argv[optind++]) != 0)
 898                         return 1;
 899         }
 900
 901         if (ndevs == 0) {
 902                 show_usage(argv[0]);
 903                 return 1;
 904         }
 905
 906         if (!relay_path)
 907                 relay_path = default_relay_path;
 908
 909         if (act_mask_tmp != 0)
 910                 act_mask = act_mask_tmp;
 911
 912         if (statfs(relay_path, &st) < 0) {
 913                 perror("statfs");
 914                 fprintf(stderr,"%s does not appear to be a valid path\n",
 915                         relay_path);
 916                 return 1;
 917         } else if (st.f_type != (long) RELAYFS_TYPE) {
 918                 fprintf(stderr,"%s does not appear to be a relay filesystem\n",
 919                         relay_path);
 920                 return 1;
 921         }
 922
 923         if (open_devices() != 0)
 924                 return 1;
 925
 926         if (kill_running_trace) {
 927                 stop_all_traces();
 928                 return 0;
 929         }
 930
 931         setlocale(LC_NUMERIC, "en_US");
 932
 933         ncpus = sysconf(_SC_NPROCESSORS_ONLN);
 934         if (ncpus < 0) {
 935                 fprintf(stderr, "sysconf(_SC_NPROCESSORS_ONLN) failed\n");
 936                 return 1;
 937         }
 938
 939         if (start_devices() != 0)
 940                 return 1;
 941
 942         signal(SIGINT, handle_sigint);
 943         signal(SIGHUP, handle_sigint);
 944         signal(SIGTERM, handle_sigint);
 945         signal(SIGALRM, handle_sigint);
 946
 947         atexit(stop_all_tracing);
 948
 949         if (stop_watch)
 950                 alarm(stop_watch);
 951
 952         get_and_write_events();
 953
 954         if (!is_trace_stopped()) {
 955                 trace_stopped = 1;
 956                 stop_all_threads();
 957                 stop_all_traces();
 958         }
 959
 960         show_stats();
 961
 962         return 0;
 963 }
 964