lib/libdevstat/devstat.c

   1 /*
   2  * Copyright (c) 1997, 1998 Kenneth D. Merry.
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. The name of the author may not be used to endorse or promote products
  14  *    derived from this software without specific prior written permission.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  26  * SUCH DAMAGE.
  27  *
  28  * $FreeBSD: src/lib/libdevstat/devstat.c,v 1.6 1999/08/28 00:04:26 peter Exp $
  29  * $DragonFly: src/lib/libdevstat/devstat.c,v 1.5 2005/01/08 19:19:26 joerg Exp $
  30  */
  31
  32 #include <sys/types.h>
  33 #include <sys/sysctl.h>
  34 #include <sys/errno.h>
  35
  36 #include <ctype.h>
  37 #include <err.h>
  38 #include <stdio.h>
  39 #include <stdlib.h>
  40 #include <string.h>
  41
  42 #include "devstat.h"
  43
  44 char devstat_errbuf[DEVSTAT_ERRBUF_SIZE];
  45
  46 /*
  47  * Table to match descriptive strings with device types.  These are in
  48  * order from most common to least common to speed search time.
  49  */
  50 struct devstat_match_table match_table[] = {
  51         {"da",          DEVSTAT_TYPE_DIRECT,    DEVSTAT_MATCH_TYPE},
  52         {"cd",          DEVSTAT_TYPE_CDROM,     DEVSTAT_MATCH_TYPE},
  53         {"scsi",        DEVSTAT_TYPE_IF_SCSI,   DEVSTAT_MATCH_IF},
  54         {"ide",         DEVSTAT_TYPE_IF_IDE,    DEVSTAT_MATCH_IF},
  55         {"other",       DEVSTAT_TYPE_IF_OTHER,  DEVSTAT_MATCH_IF},
  56         {"worm",        DEVSTAT_TYPE_WORM,      DEVSTAT_MATCH_TYPE},
  57         {"sa",          DEVSTAT_TYPE_SEQUENTIAL,DEVSTAT_MATCH_TYPE},
  58         {"pass",        DEVSTAT_TYPE_PASS,      DEVSTAT_MATCH_PASS},
  59         {"optical",     DEVSTAT_TYPE_OPTICAL,   DEVSTAT_MATCH_TYPE},
  60         {"array",       DEVSTAT_TYPE_STORARRAY, DEVSTAT_MATCH_TYPE},
  61         {"changer",     DEVSTAT_TYPE_CHANGER,   DEVSTAT_MATCH_TYPE},
  62         {"scanner",     DEVSTAT_TYPE_SCANNER,   DEVSTAT_MATCH_TYPE},
  63         {"printer",     DEVSTAT_TYPE_PRINTER,   DEVSTAT_MATCH_TYPE},
  64         {"floppy",      DEVSTAT_TYPE_FLOPPY,    DEVSTAT_MATCH_TYPE},
  65         {"proc",        DEVSTAT_TYPE_PROCESSOR, DEVSTAT_MATCH_TYPE},
  66         {"comm",        DEVSTAT_TYPE_COMM,      DEVSTAT_MATCH_TYPE},
  67         {"enclosure",   DEVSTAT_TYPE_ENCLOSURE, DEVSTAT_MATCH_TYPE},
  68         {NULL,          0,                      0}
  69 };
  70
  71 /*
  72  * Local function declarations.
  73  */
  74 static int compare_select(const void *arg1, const void *arg2);
  75
  76 int
  77 getnumdevs(void)
  78 {
  79         size_t numdevsize;
  80         int numdevs;
  81         const char *func_name = "getnumdevs";
  82
  83         numdevsize = sizeof(int);
  84
  85         /*
  86          * Find out how many devices we have in the system.
  87          */
  88         if (sysctlbyname("kern.devstat.numdevs", &numdevs,
  89                          &numdevsize, NULL, 0) == -1) {
  90                 sprintf(devstat_errbuf, "%s: error getting number of devices\n"
  91                         "%s: %s", func_name, func_name, strerror(errno));
  92                 return(-1);
  93         } else
  94                 return(numdevs);
  95 }
  96
  97 /*
  98  * This is an easy way to get the generation number, but the generation is
  99  * supplied in a more atmoic manner by the kern.devstat.all sysctl.
 100  * Because this generation sysctl is separate from the statistics sysctl,
 101  * the device list and the generation could change between the time that
 102  * this function is called and the device list is retreived.
 103  */
 104 long
 105 getgeneration(void)
 106 {
 107         size_t gensize;
 108         long generation;
 109         const char *func_name = "getgeneration";
 110
 111         gensize = sizeof(long);
 112
 113         /*
 114          * Get the current generation number.
 115          */
 116         if (sysctlbyname("kern.devstat.generation", &generation,
 117                          &gensize, NULL, 0) == -1) {
 118                 sprintf(devstat_errbuf,"%s: error getting devstat generation\n"
 119                         "%s: %s", func_name, func_name, strerror(errno));
 120                 return(-1);
 121         } else
 122                 return(generation);
 123 }
 124
 125 /*
 126  * Get the current devstat version.  The return value of this function
 127  * should be compared with DEVSTAT_VERSION, which is defined in
 128  * sys/devicestat.h.  This will enable userland programs to determine
 129  * whether they are out of sync with the kernel.
 130  */
 131 int
 132 getversion(void)
 133 {
 134         size_t versize;
 135         int version;
 136         const char *func_name = "getversion";
 137
 138         versize = sizeof(int);
 139
 140         /*
 141          * Get the current devstat version.
 142          */
 143         if (sysctlbyname("kern.devstat.version", &version, &versize,
 144                          NULL, 0) == -1) {
 145                 sprintf(devstat_errbuf, "%s: error getting devstat version\n"
 146                         "%s: %s", func_name, func_name, strerror(errno));
 147                 return(-1);
 148         } else
 149                 return(version);
 150 }
 151
 152 /*
 153  * Check the devstat version we know about against the devstat version the
 154  * kernel knows about.  If they don't match, print an error into the
 155  * devstat error buffer, and return -1.  If they match, return 0.
 156  */
 157 int
 158 checkversion(void)
 159 {
 160         int retval = 0;
 161         int errlen = 0;
 162         const char *func_name = "checkversion";
 163         int version;
 164
 165         version = getversion();
 166
 167         if (version != DEVSTAT_VERSION) {
 168                 int buflen = 0;
 169                 char tmpstr[256];
 170
 171                 /*
 172                  * This is really pretty silly, but basically the idea is
 173                  * that if getversion() returns an error (i.e. -1), then it
 174                  * has printed an error message in the buffer.  Therefore,
 175                  * we need to add a \n to the end of that message before we
 176                  * print our own message in the buffer.
 177                  */
 178                 if (version == -1) {
 179                         buflen = strlen(devstat_errbuf);
 180                         errlen = snprintf(tmpstr, sizeof(tmpstr), "\n");
 181                         strncat(devstat_errbuf, tmpstr,
 182                                 DEVSTAT_ERRBUF_SIZE - buflen - 1);
 183                         buflen += errlen;
 184                 }
 185
 186                 errlen = snprintf(tmpstr, sizeof(tmpstr),
 187                                   "%s: userland devstat version %d is not "
 188                                   "the same as the kernel\n%s: devstat "
 189                                   "version %d\n", func_name, DEVSTAT_VERSION,
 190                                   func_name, version);
 191
 192                 if (version == -1) {
 193                         strncat(devstat_errbuf, tmpstr,
 194                                 DEVSTAT_ERRBUF_SIZE - buflen - 1);
 195                         buflen += errlen;
 196                 } else {
 197                         strncpy(devstat_errbuf, tmpstr, DEVSTAT_ERRBUF_SIZE);
 198                         devstat_errbuf[DEVSTAT_ERRBUF_SIZE - 1] = '\0';
 199                 }
 200
 201                 if (version < DEVSTAT_VERSION)
 202                         snprintf(tmpstr, sizeof(tmpstr),
 203                                  "%s: libdevstat newer than kernel\n",
 204                                  func_name);
 205                 else
 206                         snprintf(tmpstr, sizeof(tmpstr),
 207                                  "%s: kernel newer than libdevstat\n",
 208                                  func_name);
 209
 210                 strncat(devstat_errbuf, tmpstr,
 211                         DEVSTAT_ERRBUF_SIZE - buflen - 1);
 212
 213                 retval = -1;
 214         }
 215
 216         return(retval);
 217 }
 218
 219 /*
 220  * Get the current list of devices and statistics, and the current
 221  * generation number.
 222  *
 223  * Return values:
 224  * -1  -- error
 225  *  0  -- device list is unchanged
 226  *  1  -- device list has changed
 227  */
 228 int
 229 getdevs(struct statinfo *stats)
 230 {
 231         int error;
 232         size_t dssize;
 233         int oldnumdevs;
 234         long oldgeneration;
 235         int retval = 0;
 236         struct devinfo *dinfo;
 237         const char *func_name = "getdevs";
 238
 239         dinfo = stats->dinfo;
 240
 241         if (dinfo == NULL) {
 242                 sprintf(devstat_errbuf, "%s: stats->dinfo was NULL", func_name);
 243                 return(-1);
 244         }
 245
 246         oldnumdevs = dinfo->numdevs;
 247         oldgeneration = dinfo->generation;
 248
 249         /*
 250          * If this is our first time through, mem_ptr will be null.
 251          */
 252         if (dinfo->mem_ptr == NULL) {
 253                 /*
 254                  * Get the number of devices.  If it's negative, it's an
 255                  * error.  Don't bother setting the error string, since
 256                  * getnumdevs() has already done that for us.
 257                  */
 258                 if ((dinfo->numdevs = getnumdevs()) < 0)
 259                         return(-1);
 260
 261                 /*
 262                  * The kern.devstat.all sysctl returns the current generation
 263                  * number, as well as all the devices.  So we need four
 264                  * bytes more.
 265                  */
 266                 dssize =(dinfo->numdevs * sizeof(struct devstat)) +sizeof(long);
 267                 dinfo->mem_ptr = (u_int8_t *)malloc(dssize);
 268         } else
 269                 dssize =(dinfo->numdevs * sizeof(struct devstat)) +sizeof(long);
 270
 271         /* Get the current time when we get the stats */
 272         gettimeofday(&stats->busy_time, NULL);
 273
 274         /*
 275          * Request all of the devices.  We only really allow for one
 276          * ENOMEM failure.  It would, of course, be possible to just go in
 277          * a loop and keep reallocing the device structure until we don't
 278          * get ENOMEM back.  I'm not sure it's worth it, though.  If
 279          * devices are being added to the system that quickly, maybe the
 280          * user can just wait until all devices are added.
 281          */
 282         if ((error = sysctlbyname("kern.devstat.all", dinfo->mem_ptr,
 283              &dssize, NULL, 0)) == -1) {
 284                 /*
 285                  * If we get ENOMEM back, that means that there are
 286                  * more devices now, so we need to allocate more
 287                  * space for the device array.
 288                  */
 289                 if (errno == ENOMEM) {
 290                         /*
 291                          * No need to set the error string here, getnumdevs()
 292                          * will do that if it fails.
 293                          */
 294                         if ((dinfo->numdevs = getnumdevs()) < 0)
 295                                 return(-1);
 296
 297                         dssize = (dinfo->numdevs * sizeof(struct devstat)) +
 298                                 sizeof(long);
 299                         dinfo->mem_ptr = (u_int8_t *)realloc(dinfo->mem_ptr,
 300                                                              dssize);
 301                         if ((error = sysctlbyname("kern.devstat.all",
 302                             dinfo->mem_ptr, &dssize, NULL, 0)) == -1) {
 303                                 sprintf(devstat_errbuf,
 304                                         "%s: error getting device stats\n"
 305                                         "%s: %s", func_name, func_name,
 306                                         strerror(errno));
 307                                 return(-1);
 308                         }
 309                 } else {
 310                         sprintf(devstat_errbuf,
 311                                 "%s: error getting device stats\n"
 312                                 "%s: %s", func_name, func_name,
 313                                 strerror(errno));
 314                         return(-1);
 315                 }
 316         }
 317
 318         /*
 319          * The sysctl spits out the generation as the first four bytes,
 320          * then all of the device statistics structures.
 321          */
 322         dinfo->generation = *(long *)dinfo->mem_ptr;
 323
 324         /*
 325          * If the generation has changed, and if the current number of
 326          * devices is not the same as the number of devices recorded in the
 327          * devinfo structure, it is likely that the device list has shrunk.
 328          * The reason that it is likely that the device list has shrunk in
 329          * this case is that if the device list has grown, the sysctl above
 330          * will return an ENOMEM error, and we will reset the number of
 331          * devices and reallocate the device array.  If the second sysctl
 332          * fails, we will return an error and therefore never get to this
 333          * point.  If the device list has shrunk, the sysctl will not
 334          * return an error since we have more space allocated than is
 335          * necessary.  So, in the shrinkage case, we catch it here and
 336          * reallocate the array so that we don't use any more space than is
 337          * necessary.
 338          */
 339         if (oldgeneration != dinfo->generation) {
 340                 if (getnumdevs() != dinfo->numdevs) {
 341                         if ((dinfo->numdevs = getnumdevs()) < 0)
 342                                 return(-1);
 343                         dssize = (dinfo->numdevs * sizeof(struct devstat)) +
 344                                 sizeof(long);
 345                         dinfo->mem_ptr = (u_int8_t *)realloc(dinfo->mem_ptr,
 346                                                              dssize);
 347                 }
 348                 retval = 1;
 349         }
 350
 351         dinfo->devices = (struct devstat *)(dinfo->mem_ptr + sizeof(long));
 352
 353         return(retval);
 354 }
 355
 356 /*
 357  * selectdevs():
 358  *
 359  * Devices are selected/deselected based upon the following criteria:
 360  * - devices specified by the user on the command line
 361  * - devices matching any device type expressions given on the command line
 362  * - devices with the highest I/O, if 'top' mode is enabled
 363  * - the first n unselected devices in the device list, if maxshowdevs
 364  *   devices haven't already been selected and if the user has not
 365  *   specified any devices on the command line and if we're in "add" mode.
 366  *
 367  * Input parameters:
 368  * - device selection list (dev_select)
 369  * - current number of devices selected (num_selected)
 370  * - total number of devices in the selection list (num_selections)
 371  * - devstat generation as of the last time selectdevs() was called
 372  *   (select_generation)
 373  * - current devstat generation (current_generation)
 374  * - current list of devices and statistics (devices)
 375  * - number of devices in the current device list (numdevs)
 376  * - compiled version of the command line device type arguments (matches)
 377  *   - This is optional.  If the number of devices is 0, this will be ignored.
 378  *   - The matching code pays attention to the current selection mode.  So
 379  *     if you pass in a matching expression, it will be evaluated based
 380  *     upon the selection mode that is passed in.  See below for details.
 381  * - number of device type matching expressions (num_matches)
 382  *   - Set to 0 to disable the matching code.
 383  * - list of devices specified on the command line by the user (dev_selections)
 384  * - number of devices selected on the command line by the user
 385  *   (num_dev_selections)
 386  * - Our selection mode.  There are four different selection modes:
 387  *      - add mode.  (DS_SELECT_ADD) Any devices matching devices explicitly
 388  *        selected by the user or devices matching a pattern given by the
 389  *        user will be selected in addition to devices that are already
 390  *        selected.  Additional devices will be selected, up to maxshowdevs
 391  *        number of devices.
 392  *      - only mode. (DS_SELECT_ONLY)  Only devices matching devices
 393  *        explicitly given by the user or devices matching a pattern
 394  *        given by the user will be selected.  No other devices will be
 395  *        selected.
 396  *      - addonly mode.  (DS_SELECT_ADDONLY)  This is similar to add and
 397  *        only.  Basically, this will not de-select any devices that are
 398  *        current selected, as only mode would, but it will also not
 399  *        gratuitously select up to maxshowdevs devices as add mode would.
 400  *      - remove mode.  (DS_SELECT_REMOVE)  Any devices matching devices
 401  *        explicitly selected by the user or devices matching a pattern
 402  *        given by the user will be de-selected.
 403  * - maximum number of devices we can select (maxshowdevs)
 404  * - flag indicating whether or not we're in 'top' mode (perf_select)
 405  *
 406  * Output data:
 407  * - the device selection list may be modified and passed back out
 408  * - the number of devices selected and the total number of items in the
 409  *   device selection list may be changed
 410  * - the selection generation may be changed to match the current generation
 411  *
 412  * Return values:
 413  * -1  -- error
 414  *  0  -- selected devices are unchanged
 415  *  1  -- selected devices changed
 416  */
 417 int
 418 selectdevs(struct device_selection **dev_select, int *num_selected,
 419            int *num_selections, long *select_generation,
 420            long current_generation, struct devstat *devices, int numdevs,
 421            struct devstat_match *matches, int num_matches,
 422            char **dev_selections, int num_dev_selections,
 423            devstat_select_mode select_mode, int maxshowdevs, int perf_select)
 424 {
 425         int i, j, k;
 426         int init_selections = 0, init_selected_var = 0;
 427         struct device_selection *old_dev_select = NULL;
 428         int old_num_selections = 0, old_num_selected;
 429         int selection_number = 0;
 430         int changed = 0, found = 0;
 431
 432         if ((dev_select == NULL) || (devices == NULL) || (numdevs <= 0))
 433                 return(-1);
 434
 435         /*
 436          * We always want to make sure that we have as many dev_select
 437          * entries as there are devices.
 438          */
 439         /*
 440          * In this case, we haven't selected devices before.
 441          */
 442         if (*dev_select == NULL) {
 443                 *dev_select = (struct device_selection *)malloc(numdevs *
 444                         sizeof(struct device_selection));
 445                 *select_generation = current_generation;
 446                 init_selections = 1;
 447                 changed = 1;
 448         /*
 449          * In this case, we have selected devices before, but the device
 450          * list has changed since we last selected devices, so we need to
 451          * either enlarge or reduce the size of the device selection list.
 452          */
 453         } else if (*num_selections != numdevs) {
 454                 *dev_select = (struct device_selection *)realloc(*dev_select,
 455                         numdevs * sizeof(struct device_selection));
 456                 *select_generation = current_generation;
 457                 init_selections = 1;
 458         /*
 459          * In this case, we've selected devices before, and the selection
 460          * list is the same size as it was the last time, but the device
 461          * list has changed.
 462          */
 463         } else if (*select_generation < current_generation) {
 464                 *select_generation = current_generation;
 465                 init_selections = 1;
 466         }
 467
 468         /*
 469          * If we're in "only" mode, we want to clear out the selected
 470          * variable since we're going to select exactly what the user wants
 471          * this time through.
 472          */
 473         if (select_mode == DS_SELECT_ONLY)
 474                 init_selected_var = 1;
 475
 476         /*
 477          * In all cases, we want to back up the number of selected devices.
 478          * It is a quick and accurate way to determine whether the selected
 479          * devices have changed.
 480          */
 481         old_num_selected = *num_selected;
 482
 483         /*
 484          * We want to make a backup of the current selection list if
 485          * the list of devices has changed, or if we're in performance
 486          * selection mode.  In both cases, we don't want to make a backup
 487          * if we already know for sure that the list will be different.
 488          * This is certainly the case if this is our first time through the
 489          * selection code.
 490          */
 491         if (((init_selected_var != 0) || (init_selections != 0)
 492          || (perf_select != 0)) && (changed == 0)){
 493                 old_dev_select = (struct device_selection *)malloc(
 494                     *num_selections * sizeof(struct device_selection));
 495                 old_num_selections = *num_selections;
 496                 bcopy(*dev_select, old_dev_select,
 497                     sizeof(struct device_selection) * *num_selections);
 498         }
 499
 500         if (init_selections != 0) {
 501                 bzero(*dev_select, sizeof(struct device_selection) * numdevs);
 502
 503                 for (i = 0; i < numdevs; i++) {
 504                         (*dev_select)[i].device_number =
 505                                 devices[i].device_number;
 506                         strncpy((*dev_select)[i].device_name,
 507                                 devices[i].device_name,
 508                                 DEVSTAT_NAME_LEN);
 509                         (*dev_select)[i].device_name[DEVSTAT_NAME_LEN - 1]='\0';
 510                         (*dev_select)[i].unit_number = devices[i].unit_number;
 511                         (*dev_select)[i].position = i;
 512                 }
 513                 *num_selections = numdevs;
 514         } else if (init_selected_var != 0) {
 515                 for (i = 0; i < numdevs; i++)
 516                         (*dev_select)[i].selected = 0;
 517         }
 518
 519         /* we haven't gotten around to selecting anything yet.. */
 520         if ((select_mode == DS_SELECT_ONLY) || (init_selections != 0)
 521          || (init_selected_var != 0))
 522                 *num_selected = 0;
 523
 524         /*
 525          * Look through any devices the user specified on the command line
 526          * and see if they match known devices.  If so, select them.
 527          */
 528         for (i = 0; (i < *num_selections) && (num_dev_selections > 0); i++) {
 529                 char tmpstr[80];
 530
 531                 snprintf(tmpstr, sizeof(tmpstr), "%s%d",
 532                         (*dev_select)[i].device_name,
 533                         (*dev_select)[i].unit_number);
 534                 for (j = 0; j < num_dev_selections; j++) {
 535                         if (strcmp(tmpstr, dev_selections[j]) == 0) {
 536                                 /*
 537                                  * Here we do different things based on the
 538                                  * mode we're in.  If we're in add or
 539                                  * addonly mode, we only select this device
 540                                  * if it hasn't already been selected.
 541                                  * Otherwise, we would be unnecessarily
 542                                  * changing the selection order and
 543                                  * incrementing the selection count.  If
 544                                  * we're in only mode, we unconditionally
 545                                  * select this device, since in only mode
 546                                  * any previous selections are erased and
 547                                  * manually specified devices are the first
 548                                  * ones to be selected.  If we're in remove
 549                                  * mode, we de-select the specified device and
 550                                  * decrement the selection count.
 551                                  */
 552                                 switch(select_mode) {
 553                                 case DS_SELECT_ADD:
 554                                 case DS_SELECT_ADDONLY:
 555                                         if ((*dev_select)[i].selected)
 556                                                 break;
 557                                         /* FALLTHROUGH */
 558                                 case DS_SELECT_ONLY:
 559                                         (*dev_select)[i].selected =
 560                                                 ++selection_number;
 561                                         (*num_selected)++;
 562                                         break;
 563                                 case DS_SELECT_REMOVE:
 564                                         (*dev_select)[i].selected = 0;
 565                                         (*num_selected)--;
 566                                         /*
 567                                          * This isn't passed back out, we
 568                                          * just use it to keep track of
 569                                          * how many devices we've removed.
 570                                          */
 571                                         num_dev_selections--;
 572                                         break;
 573                                 }
 574                                 break;
 575                         }
 576                 }
 577         }
 578
 579         /*
 580          * Go through the user's device type expressions and select devices
 581          * accordingly.  We only do this if the number of devices already
 582          * selected is less than the maximum number we can show.
 583          */
 584         for (i = 0; (i < num_matches) && (*num_selected < maxshowdevs); i++) {
 585                 /* We should probably indicate some error here */
 586                 if ((matches[i].match_fields == DEVSTAT_MATCH_NONE)
 587                  || (matches[i].num_match_categories <= 0))
 588                         continue;
 589
 590                 for (j = 0; j < numdevs; j++) {
 591                         int num_match_categories;
 592
 593                         num_match_categories = matches[i].num_match_categories;
 594
 595                         /*
 596                          * Determine whether or not the current device
 597                          * matches the given matching expression.  This if
 598                          * statement consists of three components:
 599                          *   - the device type check
 600                          *   - the device interface check
 601                          *   - the passthrough check
 602                          * If a the matching test is successful, it
 603                          * decrements the number of matching categories,
 604                          * and if we've reached the last element that
 605                          * needed to be matched, the if statement succeeds.
 606                          *
 607                          */
 608                         if ((((matches[i].match_fields & DEVSTAT_MATCH_TYPE)!=0)
 609                           && ((devices[j].device_type & DEVSTAT_TYPE_MASK) ==
 610                                 (matches[i].device_type & DEVSTAT_TYPE_MASK))
 611                           &&(((matches[i].match_fields & DEVSTAT_MATCH_PASS)!=0)
 612                            || (((matches[i].match_fields &
 613                                 DEVSTAT_MATCH_PASS) == 0)
 614                             && ((devices[j].device_type &
 615                                 DEVSTAT_TYPE_PASS) == 0)))
 616                           && (--num_match_categories == 0))
 617                          || (((matches[i].match_fields & DEVSTAT_MATCH_IF) != 0)
 618                           && ((devices[j].device_type & DEVSTAT_TYPE_IF_MASK) ==
 619                                 (matches[i].device_type & DEVSTAT_TYPE_IF_MASK))
 620                           &&(((matches[i].match_fields & DEVSTAT_MATCH_PASS)!=0)
 621                            || (((matches[i].match_fields &
 622                                 DEVSTAT_MATCH_PASS) == 0)
 623                             && ((devices[j].device_type &
 624                                 DEVSTAT_TYPE_PASS) == 0)))
 625                           && (--num_match_categories == 0))
 626                          || (((matches[i].match_fields & DEVSTAT_MATCH_PASS)!=0)
 627                           && ((devices[j].device_type & DEVSTAT_TYPE_PASS) != 0)
 628                           && (--num_match_categories == 0))) {
 629
 630                                 /*
 631                                  * This is probably a non-optimal solution
 632                                  * to the problem that the devices in the
 633                                  * device list will not be in the same
 634                                  * order as the devices in the selection
 635                                  * array.
 636                                  */
 637                                 for (k = 0; k < numdevs; k++) {
 638                                         if ((*dev_select)[k].position == j) {
 639                                                 found = 1;
 640                                                 break;
 641                                         }
 642                                 }
 643
 644                                 /*
 645                                  * There shouldn't be a case where a device
 646                                  * in the device list is not in the
 647                                  * selection list...but it could happen.
 648                                  */
 649                                 if (found != 1) {
 650                                         fprintf(stderr, "selectdevs: couldn't"
 651                                                 " find %s%d in selection "
 652                                                 "list\n",
 653                                                 devices[j].device_name,
 654                                                 devices[j].unit_number);
 655                                         break;
 656                                 }
 657
 658                                 /*
 659                                  * We do different things based upon the
 660                                  * mode we're in.  If we're in add or only
 661                                  * mode, we go ahead and select this device
 662                                  * if it hasn't already been selected.  If
 663                                  * it has already been selected, we leave
 664                                  * it alone so we don't mess up the
 665                                  * selection ordering.  Manually specified
 666                                  * devices have already been selected, and
 667                                  * they have higher priority than pattern
 668                                  * matched devices.  If we're in remove
 669                                  * mode, we de-select the given device and
 670                                  * decrement the selected count.
 671                                  */
 672                                 switch(select_mode) {
 673                                 case DS_SELECT_ADD:
 674                                 case DS_SELECT_ADDONLY:
 675                                 case DS_SELECT_ONLY:
 676                                         if ((*dev_select)[k].selected != 0)
 677                                                 break;
 678                                         (*dev_select)[k].selected =
 679                                                 ++selection_number;
 680                                         (*num_selected)++;
 681                                         break;
 682                                 case DS_SELECT_REMOVE:
 683                                         (*dev_select)[k].selected = 0;
 684                                         (*num_selected)--;
 685                                         break;
 686                                 }
 687                         }
 688                 }
 689         }
 690
 691         /*
 692          * Here we implement "top" mode.  Devices are sorted in the
 693          * selection array based on two criteria:  whether or not they are
 694          * selected (not selection number, just the fact that they are
 695          * selected!) and the number of bytes in the "bytes" field of the
 696          * selection structure.  The bytes field generally must be kept up
 697          * by the user.  In the future, it may be maintained by library
 698          * functions, but for now the user has to do the work.
 699          *
 700          * At first glance, it may seem wrong that we don't go through and
 701          * select every device in the case where the user hasn't specified
 702          * any devices or patterns.  In fact, though, it won't make any
 703          * difference in the device sorting.  In that particular case (i.e.
 704          * when we're in "add" or "only" mode, and the user hasn't
 705          * specified anything) the first time through no devices will be
 706          * selected, so the only criterion used to sort them will be their
 707          * performance.  The second time through, and every time thereafter,
 708          * all devices will be selected, so again selection won't matter.
 709          */
 710         if (perf_select != 0) {
 711
 712                 /* Sort the device array by throughput  */
 713                 qsort(*dev_select, *num_selections,
 714                       sizeof(struct device_selection),
 715                       compare_select);
 716
 717                 if (*num_selected == 0) {
 718                         /*
 719                          * Here we select every device in the array, if it
 720                          * isn't already selected.  Because the 'selected'
 721                          * variable in the selection array entries contains
 722                          * the selection order, the devstats routine can show
 723                          * the devices that were selected first.
 724                          */
 725                         for (i = 0; i < *num_selections; i++) {
 726                                 if ((*dev_select)[i].selected == 0) {
 727                                         (*dev_select)[i].selected =
 728                                                 ++selection_number;
 729                                         (*num_selected)++;
 730                                 }
 731                         }
 732                 } else {
 733                         selection_number = 0;
 734                         for (i = 0; i < *num_selections; i++) {
 735                                 if ((*dev_select)[i].selected != 0) {
 736                                         (*dev_select)[i].selected =
 737                                                 ++selection_number;
 738                                 }
 739                         }
 740                 }
 741         }
 742
 743         /*
 744          * If we're in the "add" selection mode and if we haven't already
 745          * selected maxshowdevs number of devices, go through the array and
 746          * select any unselected devices.  If we're in "only" mode, we
 747          * obviously don't want to select anything other than what the user
 748          * specifies.  If we're in "remove" mode, it probably isn't a good
 749          * idea to go through and select any more devices, since we might
 750          * end up selecting something that the user wants removed.  Through
 751          * more complicated logic, we could actually figure this out, but
 752          * that would probably require combining this loop with the various
 753          * selections loops above.
 754          */
 755         if ((select_mode == DS_SELECT_ADD) && (*num_selected < maxshowdevs)) {
 756                 for (i = 0; i < *num_selections; i++)
 757                         if ((*dev_select)[i].selected == 0) {
 758                                 (*dev_select)[i].selected = ++selection_number;
 759                                 (*num_selected)++;
 760                         }
 761         }
 762
 763         /*
 764          * Look at the number of devices that have been selected.  If it
 765          * has changed, set the changed variable.  Otherwise, if we've
 766          * made a backup of the selection list, compare it to the current
 767          * selection list to see if the selected devices have changed.
 768          */
 769         if ((changed == 0) && (old_num_selected != *num_selected))
 770                 changed = 1;
 771         else if ((changed == 0) && (old_dev_select != NULL)) {
 772                 /*
 773                  * Now we go through the selection list and we look at
 774                  * it three different ways.
 775                  */
 776                 for (i = 0; (i < *num_selections) && (changed == 0) &&
 777                      (i < old_num_selections); i++) {
 778                         /*
 779                          * If the device at index i in both the new and old
 780                          * selection arrays has the same device number and
 781                          * selection status, it hasn't changed.  We
 782                          * continue on to the next index.
 783                          */
 784                         if (((*dev_select)[i].device_number ==
 785                              old_dev_select[i].device_number)
 786                          && ((*dev_select)[i].selected ==
 787                              old_dev_select[i].selected))
 788                                 continue;
 789
 790                         /*
 791                          * Now, if we're still going through the if
 792                          * statement, the above test wasn't true.  So we
 793                          * check here to see if the device at index i in
 794                          * the current array is the same as the device at
 795                          * index i in the old array.  If it is, that means
 796                          * that its selection number has changed.  Set
 797                          * changed to 1 and exit the loop.
 798                          */
 799                         else if ((*dev_select)[i].device_number ==
 800                                   old_dev_select[i].device_number) {
 801                                 changed = 1;
 802                                 break;
 803                         }
 804                         /*
 805                          * If we get here, then the device at index i in
 806                          * the current array isn't the same device as the
 807                          * device at index i in the old array.
 808                          */
 809                         else {
 810                                 found = 0;
 811
 812                                 /*
 813                                  * Search through the old selection array
 814                                  * looking for a device with the same
 815                                  * device number as the device at index i
 816                                  * in the current array.  If the selection
 817                                  * status is the same, then we mark it as
 818                                  * found.  If the selection status isn't
 819                                  * the same, we break out of the loop.
 820                                  * Since found isn't set, changed will be
 821                                  * set to 1 below.
 822                                  */
 823                                 for (j = 0; j < old_num_selections; j++) {
 824                                         if (((*dev_select)[i].device_number ==
 825                                               old_dev_select[j].device_number)
 826                                          && ((*dev_select)[i].selected ==
 827                                               old_dev_select[j].selected)){
 828                                                 found = 1;
 829                                                 break;
 830                                         }
 831                                         else if ((*dev_select)[i].device_number
 832                                             == old_dev_select[j].device_number)
 833                                                 break;
 834                                 }
 835                                 if (found == 0)
 836                                         changed = 1;
 837                         }
 838                 }
 839         }
 840         if (old_dev_select != NULL)
 841                 free(old_dev_select);
 842
 843         return(changed);
 844 }
 845
 846 /*
 847  * Comparison routine for qsort() above.  Note that the comparison here is
 848  * backwards -- generally, it should return a value to indicate whether
 849  * arg1 is <, =, or > arg2.  Instead, it returns the opposite.  The reason
 850  * it returns the opposite is so that the selection array will be sorted in
 851  * order of decreasing performance.  We sort on two parameters.  The first
 852  * sort key is whether or not one or the other of the devices in question
 853  * has been selected.  If one of them has, and the other one has not, the
 854  * selected device is automatically more important than the unselected
 855  * device.  If neither device is selected, we judge the devices based upon
 856  * performance.
 857  */
 858 static int
 859 compare_select(const void *arg1, const void *arg2)
 860 {
 861         if ((((const struct device_selection *)arg1)->selected)
 862          && (((const struct device_selection *)arg2)->selected == 0))
 863                 return(-1);
 864         else if ((((const struct device_selection *)arg1)->selected == 0)
 865               && (((const struct device_selection *)arg2)->selected))
 866                 return(1);
 867         else if (((const struct device_selection *)arg2)->bytes <
 868                  ((const struct device_selection *)arg1)->bytes)
 869                 return(-1);
 870         else if (((const struct device_selection *)arg2)->bytes >
 871                  ((const struct device_selection *)arg1)->bytes)
 872                 return(1);
 873         else
 874                 return(0);
 875 }
 876
 877 /*
 878  * Take a string with the general format "arg1,arg2,arg3", and build a
 879  * device matching expression from it.
 880  */
 881 int
 882 buildmatch(const char *match_str, struct devstat_match **matches,
 883            int *num_matches)
 884 {
 885         char *tstr[5];
 886         char **tempstr;
 887         char *matchbuf_orig;    /* strdup of match_str */
 888         char *matchbuf;         /* allow strsep to clobber */
 889         int num_args;
 890         int i, j;
 891         int retval = -1;
 892
 893         /* We can't do much without a string to parse */
 894         if (match_str == NULL) {
 895                 sprintf(devstat_errbuf, "%s: no match expression", __func__);
 896                 return(-1);
 897         }
 898
 899         /*
 900          * Break the (comma delimited) input string out into separate strings.
 901          * strsep is destructive, so copy the string first.
 902          */
 903         matchbuf = matchbuf_orig = strdup(match_str);
 904         if (matchbuf == NULL) {
 905                 sprintf(devstat_errbuf, "%s: out of memory", __func__);
 906                 return(-1);
 907         }
 908         for (tempstr = tstr, num_args  = 0;
 909              (*tempstr = strsep(&matchbuf, ",")) != NULL && (num_args < 5);
 910              num_args++)
 911                 if (**tempstr != '\0')
 912                         if (++tempstr >= &tstr[5])
 913                                 break;
 914
 915         /* The user gave us too many type arguments */
 916         if (num_args > 3) {
 917                 sprintf(devstat_errbuf, "%s: too many type arguments",
 918                         __func__);
 919                 goto cleanup;
 920         }
 921
 922         /*
 923          * Since you can't realloc a pointer that hasn't been malloced
 924          * first, we malloc first and then realloc.
 925          */
 926         if (*num_matches == 0)
 927                 *matches = (struct devstat_match *)malloc(
 928                            sizeof(struct devstat_match));
 929         else
 930                 *matches = (struct devstat_match *)realloc(*matches,
 931                           sizeof(struct devstat_match) * (*num_matches + 1));
 932
 933         /* Make sure the current entry is clear */
 934         bzero(&matches[0][*num_matches], sizeof(struct devstat_match));
 935
 936         /*
 937          * Step through the arguments the user gave us and build a device
 938          * matching expression from them.
 939          */
 940         for (i = 0; i < num_args; i++) {
 941                 char *tempstr2, *tempstr3;
 942
 943                 /*
 944                  * Get rid of leading white space.
 945                  */
 946                 tempstr2 = tstr[i];
 947                 while (isspace(*tempstr2) && (*tempstr2 != '\0'))
 948                         tempstr2++;
 949
 950                 /*
 951                  * Get rid of trailing white space.
 952                  */
 953                 tempstr3 = &tempstr2[strlen(tempstr2) - 1];
 954
 955                 while ((*tempstr3 != '\0') && (tempstr3 > tempstr2)
 956                     && (isspace(*tempstr3))) {
 957                         *tempstr3 = '\0';
 958                         tempstr3--;
 959                 }
 960
 961                 /*
 962                  * Go through the match table comparing the user's
 963                  * arguments to known device types, interfaces, etc.
 964                  */
 965                 for (j = 0; match_table[j].match_str != NULL; j++) {
 966                         /*
 967                          * We do case-insensitive matching, in case someone
 968                          * wants to enter "SCSI" instead of "scsi" or
 969                          * something like that.  Only compare as many
 970                          * characters as are in the string in the match
 971                          * table.  This should help if someone tries to use
 972                          * a super-long match expression.
 973                          */
 974                         if (strncasecmp(tempstr2, match_table[j].match_str,
 975                             strlen(match_table[j].match_str)) == 0) {
 976                                 /*
 977                                  * Make sure the user hasn't specified two
 978                                  * items of the same type, like "da" and
 979                                  * "cd".  One device cannot be both.
 980                                  */
 981                                 if (((*matches)[*num_matches].match_fields &
 982                                     match_table[j].match_field) != 0) {
 983                                         sprintf(devstat_errbuf,
 984                                                 "%s: cannot have more than "
 985                                                 "one match item in a single "
 986                                                 "category", __func__);
 987                                         goto cleanup;
 988                                 }
 989                                 /*
 990                                  * If we've gotten this far, we have a
 991                                  * winner.  Set the appropriate fields in
 992                                  * the match entry.
 993                                  */
 994                                 (*matches)[*num_matches].match_fields |=
 995                                         match_table[j].match_field;
 996                                 (*matches)[*num_matches].device_type |=
 997                                         match_table[j].type;
 998                                 (*matches)[*num_matches].num_match_categories++;
 999                                 break;
1000                         }
1001                 }
1002                 /*
1003                  * We should have found a match in the above for loop.  If
1004                  * not, that means the user entered an invalid device type
1005                  * or interface.
1006                  */
1007                 if ((*matches)[*num_matches].num_match_categories != (i + 1)) {
1008                         snprintf(devstat_errbuf, sizeof(devstat_errbuf),
1009                                 "%s: unknown match item \"%s\"", __func__,
1010                                 tstr[i]);
1011                         goto cleanup;
1012                 }
1013         }
1014
1015         (*num_matches)++;
1016         retval = 0;
1017 cleanup:
1018         free(matchbuf_orig);
1019         return(retval);
1020 }
1021
1022 /*
1023  * Compute a number of device statistics.  Only one field is mandatory, and
1024  * that is "current".  Everything else is optional.  The caller passes in
1025  * pointers to variables to hold the various statistics he desires.  If he
1026  * doesn't want a particular staistic, he should pass in a NULL pointer.
1027  * Return values:
1028  * 0   -- success
1029  * -1  -- failure
1030  */
1031 int
1032 compute_stats(struct devstat *current, struct devstat *previous,
1033               long double etime, u_int64_t *total_bytes,
1034               u_int64_t *total_transfers, u_int64_t *total_blocks,
1035               long double *kb_per_transfer, long double *transfers_per_second,
1036               long double *mb_per_second, long double *blocks_per_second,
1037               long double *ms_per_transaction)
1038 {
1039         u_int64_t totalbytes, totaltransfers, totalblocks;
1040
1041         /*
1042          * current is the only mandatory field.
1043          */
1044         if (current == NULL) {
1045                 sprintf(devstat_errbuf, "%s: current stats structure was NULL",
1046                         __func__);
1047                 return(-1);
1048         }
1049
1050         totalbytes = (current->bytes_written + current->bytes_read) -
1051                      ((previous) ? (previous->bytes_written +
1052                                     previous->bytes_read) : 0);
1053
1054         if (total_bytes)
1055                 *total_bytes = totalbytes;
1056
1057         totaltransfers = (current->num_reads +
1058                           current->num_writes +
1059                           current->num_other) -
1060                          ((previous) ?
1061                           (previous->num_reads +
1062                            previous->num_writes +
1063                            previous->num_other) : 0);
1064         if (total_transfers)
1065                 *total_transfers = totaltransfers;
1066
1067         if (transfers_per_second) {
1068                 if (etime > 0.0) {
1069                         *transfers_per_second = totaltransfers;
1070                         *transfers_per_second /= etime;
1071                 } else
1072                         *transfers_per_second = 0.0;
1073         }
1074
1075         if (kb_per_transfer) {
1076                 *kb_per_transfer = totalbytes;
1077                 *kb_per_transfer /= 1024;
1078                 if (totaltransfers > 0)
1079                         *kb_per_transfer /= totaltransfers;
1080                 else
1081                         *kb_per_transfer = 0.0;
1082         }
1083
1084         if (mb_per_second) {
1085                 *mb_per_second = totalbytes;
1086                 *mb_per_second /= 1024 * 1024;
1087                 if (etime > 0.0)
1088                         *mb_per_second /= etime;
1089                 else
1090                         *mb_per_second = 0.0;
1091         }
1092
1093         totalblocks = totalbytes;
1094         if (current->block_size > 0)
1095                 totalblocks /= current->block_size;
1096         else
1097                 totalblocks /= 512;
1098
1099         if (total_blocks)
1100                 *total_blocks = totalblocks;
1101
1102         if (blocks_per_second) {
1103                 *blocks_per_second = totalblocks;
1104                 if (etime > 0.0)
1105                         *blocks_per_second /= etime;
1106                 else
1107                         *blocks_per_second = 0.0;
1108         }
1109
1110         if (ms_per_transaction) {
1111                 if (totaltransfers > 0) {
1112                         *ms_per_transaction = etime;
1113                         *ms_per_transaction /= totaltransfers;
1114                         *ms_per_transaction *= 1000;
1115                 } else
1116                         *ms_per_transaction = 0.0;
1117         }
1118
1119         return(0);
1120 }
1121
1122 int
1123 compute_stats_read(struct devstat *current, struct devstat *previous,
1124               long double etime, u_int64_t *total_bytes,
1125               u_int64_t *total_transfers, u_int64_t *total_blocks,
1126               long double *kb_per_transfer, long double *transfers_per_second,
1127               long double *mb_per_second, long double *blocks_per_second,
1128               long double *ms_per_transaction)
1129 {
1130         u_int64_t totalbytes, totaltransfers, totalblocks;
1131
1132         /*
1133          * current is the only mandatory field.
1134          */
1135         if (current == NULL) {
1136                 sprintf(devstat_errbuf, "%s: current stats structure was NULL",
1137                         __func__);
1138                 return(-1);
1139         }
1140
1141         totalbytes = current->bytes_read -
1142                      (previous ? previous->bytes_read : 0);
1143
1144         if (total_bytes)
1145                 *total_bytes = totalbytes;
1146
1147         totaltransfers = current->num_reads -
1148                          (previous ? previous->num_reads : 0);
1149         if (total_transfers)
1150                 *total_transfers = totaltransfers;
1151
1152         if (transfers_per_second) {
1153                 if (etime > 0.0) {
1154                         *transfers_per_second = totaltransfers;
1155                         *transfers_per_second /= etime;
1156                 } else
1157                         *transfers_per_second = 0.0;
1158         }
1159
1160         if (kb_per_transfer) {
1161                 *kb_per_transfer = totalbytes;
1162                 *kb_per_transfer /= 1024;
1163                 if (totaltransfers > 0)
1164                         *kb_per_transfer /= totaltransfers;
1165                 else
1166                         *kb_per_transfer = 0.0;
1167         }
1168
1169         if (mb_per_second) {
1170                 *mb_per_second = totalbytes;
1171                 *mb_per_second /= 1024 * 1024;
1172                 if (etime > 0.0)
1173                         *mb_per_second /= etime;
1174                 else
1175                         *mb_per_second = 0.0;
1176         }
1177
1178         totalblocks = totalbytes;
1179         if (current->block_size > 0)
1180                 totalblocks /= current->block_size;
1181         else
1182                 totalblocks /= 512;
1183
1184         if (total_blocks)
1185                 *total_blocks = totalblocks;
1186
1187         if (blocks_per_second) {
1188                 *blocks_per_second = totalblocks;
1189                 if (etime > 0.0)
1190                         *blocks_per_second /= etime;
1191                 else
1192                         *blocks_per_second = 0.0;
1193         }
1194
1195         if (ms_per_transaction) {
1196                 if (totaltransfers > 0) {
1197                         *ms_per_transaction = etime;
1198                         *ms_per_transaction /= totaltransfers;
1199                         *ms_per_transaction *= 1000;
1200                 } else
1201                         *ms_per_transaction = 0.0;
1202         }
1203
1204         return(0);
1205 }
1206
1207 int
1208 compute_stats_write(struct devstat *current, struct devstat *previous,
1209               long double etime, u_int64_t *total_bytes,
1210               u_int64_t *total_transfers, u_int64_t *total_blocks,
1211               long double *kb_per_transfer, long double *transfers_per_second,
1212               long double *mb_per_second, long double *blocks_per_second,
1213               long double *ms_per_transaction)
1214 {
1215         u_int64_t totalbytes, totaltransfers, totalblocks;
1216
1217         /*
1218          * current is the only mandatory field.
1219          */
1220         if (current == NULL) {
1221                 sprintf(devstat_errbuf, "%s: current stats structure was NULL",
1222                         __func__);
1223                 return(-1);
1224         }
1225
1226         totalbytes = current->bytes_written -
1227                      (previous ? previous->bytes_written : 0);
1228
1229         if (total_bytes)
1230                 *total_bytes = totalbytes;
1231
1232         totaltransfers = current->num_writes -
1233                          (previous ? previous->num_writes : 0);
1234         if (total_transfers)
1235                 *total_transfers = totaltransfers;
1236
1237         if (transfers_per_second) {
1238                 if (etime > 0.0) {
1239                         *transfers_per_second = totaltransfers;
1240                         *transfers_per_second /= etime;
1241                 } else
1242                         *transfers_per_second = 0.0;
1243         }
1244
1245         if (kb_per_transfer) {
1246                 *kb_per_transfer = totalbytes;
1247                 *kb_per_transfer /= 1024;
1248                 if (totaltransfers > 0)
1249                         *kb_per_transfer /= totaltransfers;
1250                 else
1251                         *kb_per_transfer = 0.0;
1252         }
1253
1254         if (mb_per_second) {
1255                 *mb_per_second = totalbytes;
1256                 *mb_per_second /= 1024 * 1024;
1257                 if (etime > 0.0)
1258                         *mb_per_second /= etime;
1259                 else
1260                         *mb_per_second = 0.0;
1261         }
1262
1263         totalblocks = totalbytes;
1264         if (current->block_size > 0)
1265                 totalblocks /= current->block_size;
1266         else
1267                 totalblocks /= 512;
1268
1269         if (total_blocks)
1270                 *total_blocks = totalblocks;
1271
1272         if (blocks_per_second) {
1273                 *blocks_per_second = totalblocks;
1274                 if (etime > 0.0)
1275                         *blocks_per_second /= etime;
1276                 else
1277                         *blocks_per_second = 0.0;
1278         }
1279
1280         if (ms_per_transaction) {
1281                 if (totaltransfers > 0) {
1282                         *ms_per_transaction = etime;
1283                         *ms_per_transaction /= totaltransfers;
1284                         *ms_per_transaction *= 1000;
1285                 } else
1286                         *ms_per_transaction = 0.0;
1287         }
1288
1289         return(0);
1290 }
1291
1292 long double
1293 compute_etime(struct timeval cur_time, struct timeval prev_time)
1294 {
1295         struct timeval busy_time;
1296         u_int64_t busy_usec;
1297         long double etime;
1298
1299         timersub(&cur_time, &prev_time, &busy_time);
1300
1301         busy_usec = busy_time.tv_sec;
1302         busy_usec *= 1000000;
1303         busy_usec += busy_time.tv_usec;
1304         etime = busy_usec;
1305         etime /= 1000000;
1306
1307         return(etime);
1308 }