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