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         {"nvme",        DEVSTAT_TYPE_DIRECT,    DEVSTAT_MATCH_TYPE},
  53         {"xa",          DEVSTAT_TYPE_DIRECT,    DEVSTAT_MATCH_TYPE},
  54         {"cd",          DEVSTAT_TYPE_CDROM,     DEVSTAT_MATCH_TYPE},
  55         {"scsi",        DEVSTAT_TYPE_IF_SCSI,   DEVSTAT_MATCH_IF},
  56         {"ide",         DEVSTAT_TYPE_IF_IDE,    DEVSTAT_MATCH_IF},
  57         {"other",       DEVSTAT_TYPE_IF_OTHER,  DEVSTAT_MATCH_IF},
  58         {"worm",        DEVSTAT_TYPE_WORM,      DEVSTAT_MATCH_TYPE},
  59         {"sa",          DEVSTAT_TYPE_SEQUENTIAL,DEVSTAT_MATCH_TYPE},
  60         {"pass",        DEVSTAT_TYPE_PASS,      DEVSTAT_MATCH_PASS},
  61         {"optical",     DEVSTAT_TYPE_OPTICAL,   DEVSTAT_MATCH_TYPE},
  62         {"array",       DEVSTAT_TYPE_STORARRAY, DEVSTAT_MATCH_TYPE},
  63         {"changer",     DEVSTAT_TYPE_CHANGER,   DEVSTAT_MATCH_TYPE},
  64         {"scanner",     DEVSTAT_TYPE_SCANNER,   DEVSTAT_MATCH_TYPE},
  65         {"printer",     DEVSTAT_TYPE_PRINTER,   DEVSTAT_MATCH_TYPE},
  66         {"floppy",      DEVSTAT_TYPE_FLOPPY,    DEVSTAT_MATCH_TYPE},
  67         {"proc",        DEVSTAT_TYPE_PROCESSOR, DEVSTAT_MATCH_TYPE},
  68         {"comm",        DEVSTAT_TYPE_COMM,      DEVSTAT_MATCH_TYPE},
  69         {"enclosure",   DEVSTAT_TYPE_ENCLOSURE, DEVSTAT_MATCH_TYPE},
  70         {NULL,          0,                      0}
  71 };
  72
  73 /*
  74  * Local function declarations.
  75  */
  76 static int compare_select(const void *arg1, const void *arg2);
  77
  78 int
  79 getnumdevs(void)
  80 {
  81         size_t numdevsize;
  82         int numdevs;
  83         const char *func_name = "getnumdevs";
  84
  85         numdevsize = sizeof(int);
  86
  87         /*
  88          * Find out how many devices we have in the system.
  89          */
  90         if (sysctlbyname("kern.devstat.numdevs", &numdevs,
  91                          &numdevsize, NULL, 0) == -1) {
  92                 sprintf(devstat_errbuf, "%s: error getting number of devices\n"
  93                         "%s: %s", func_name, func_name, strerror(errno));
  94                 return(-1);
  95         } else
  96                 return(numdevs);
  97 }
  98
  99 /*
 100  * This is an easy way to get the generation number, but the generation is
 101  * supplied in a more atmoic manner by the kern.devstat.all sysctl.
 102  * Because this generation sysctl is separate from the statistics sysctl,
 103  * the device list and the generation could change between the time that
 104  * this function is called and the device list is retreived.
 105  */
 106 long
 107 getgeneration(void)
 108 {
 109         size_t gensize;
 110         long generation;
 111         const char *func_name = "getgeneration";
 112
 113         gensize = sizeof(long);
 114
 115         /*
 116          * Get the current generation number.
 117          */
 118         if (sysctlbyname("kern.devstat.generation", &generation,
 119                          &gensize, NULL, 0) == -1) {
 120                 sprintf(devstat_errbuf,"%s: error getting devstat generation\n"
 121                         "%s: %s", func_name, func_name, strerror(errno));
 122                 return(-1);
 123         } else
 124                 return(generation);
 125 }
 126
 127 /*
 128  * Get the current devstat version.  The return value of this function
 129  * should be compared with DEVSTAT_VERSION, which is defined in
 130  * sys/devicestat.h.  This will enable userland programs to determine
 131  * whether they are out of sync with the kernel.
 132  */
 133 int
 134 getversion(void)
 135 {
 136         size_t versize;
 137         int version;
 138         const char *func_name = "getversion";
 139
 140         versize = sizeof(int);
 141
 142         /*
 143          * Get the current devstat version.
 144          */
 145         if (sysctlbyname("kern.devstat.version", &version, &versize,
 146                          NULL, 0) == -1) {
 147                 sprintf(devstat_errbuf, "%s: error getting devstat version\n"
 148                         "%s: %s", func_name, func_name, strerror(errno));
 149                 return(-1);
 150         } else
 151                 return(version);
 152 }
 153
 154 /*
 155  * Check the devstat version we know about against the devstat version the
 156  * kernel knows about.  If they don't match, print an error into the
 157  * devstat error buffer, and return -1.  If they match, return 0.
 158  */
 159 int
 160 checkversion(void)
 161 {
 162         int retval = 0;
 163         int errlen = 0;
 164         const char *func_name = "checkversion";
 165         int version;
 166
 167         version = getversion();
 168
 169         if (version != DEVSTAT_VERSION) {
 170                 int buflen = 0;
 171                 char tmpstr[256];
 172
 173                 /*
 174                  * This is really pretty silly, but basically the idea is
 175                  * that if getversion() returns an error (i.e. -1), then it
 176                  * has printed an error message in the buffer.  Therefore,
 177                  * we need to add a \n to the end of that message before we
 178                  * print our own message in the buffer.
 179                  */
 180                 if (version == -1) {
 181                         buflen = strlen(devstat_errbuf);
 182                         errlen = snprintf(tmpstr, sizeof(tmpstr), "\n");
 183                         strncat(devstat_errbuf, tmpstr,
 184                                 DEVSTAT_ERRBUF_SIZE - buflen - 1);
 185                         buflen += errlen;
 186                 }
 187
 188                 errlen = snprintf(tmpstr, sizeof(tmpstr),
 189                                   "%s: userland devstat version %d is not "
 190                                   "the same as the kernel\n%s: devstat "
 191                                   "version %d\n", func_name, DEVSTAT_VERSION,
 192                                   func_name, version);
 193
 194                 if (version == -1) {
 195                         strncat(devstat_errbuf, tmpstr,
 196                                 DEVSTAT_ERRBUF_SIZE - buflen - 1);
 197                         buflen += errlen;
 198                 } else {
 199                         strncpy(devstat_errbuf, tmpstr, DEVSTAT_ERRBUF_SIZE);
 200                         devstat_errbuf[DEVSTAT_ERRBUF_SIZE - 1] = '\0';
 201                 }
 202
 203                 if (version < DEVSTAT_VERSION)
 204                         snprintf(tmpstr, sizeof(tmpstr),
 205                                  "%s: libdevstat newer than kernel\n",
 206                                  func_name);
 207                 else
 208                         snprintf(tmpstr, sizeof(tmpstr),
 209                                  "%s: kernel newer than libdevstat\n",
 210                                  func_name);
 211
 212                 strncat(devstat_errbuf, tmpstr,
 213                         DEVSTAT_ERRBUF_SIZE - buflen - 1);
 214
 215                 retval = -1;
 216         }
 217
 218         return(retval);
 219 }
 220
 221 /*
 222  * Get the current list of devices and statistics, and the current
 223  * generation number.
 224  *
 225  * Return values:
 226  * -1  -- error
 227  *  0  -- device list is unchanged
 228  *  1  -- device list has changed
 229  */
 230 int
 231 getdevs(struct statinfo *stats)
 232 {
 233         int error;
 234         size_t dssize;
 235         long oldgeneration;
 236         int retval = 0;
 237         struct devinfo *dinfo;
 238         const char *func_name = "getdevs";
 239
 240         dinfo = stats->dinfo;
 241
 242         if (dinfo == NULL) {
 243                 sprintf(devstat_errbuf, "%s: stats->dinfo was NULL", func_name);
 244                 return(-1);
 245         }
 246
 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                            || (((devices[j].device_type &
 613                                 DEVSTAT_TYPE_PASS) == 0)))
 614                           && (--num_match_categories == 0))
 615                          || (((matches[i].match_fields & DEVSTAT_MATCH_IF) != 0)
 616                           && ((devices[j].device_type & DEVSTAT_TYPE_IF_MASK) ==
 617                                 (matches[i].device_type & DEVSTAT_TYPE_IF_MASK))
 618                           &&(((matches[i].match_fields & DEVSTAT_MATCH_PASS)!=0)
 619                            || (((devices[j].device_type &
 620                                 DEVSTAT_TYPE_PASS) == 0)))
 621                           && (--num_match_categories == 0))
 622                          || (((matches[i].match_fields & DEVSTAT_MATCH_PASS)!=0)
 623                           && ((devices[j].device_type & DEVSTAT_TYPE_PASS) != 0)
 624                           && (--num_match_categories == 0))) {
 625
 626                                 /*
 627                                  * This is probably a non-optimal solution
 628                                  * to the problem that the devices in the
 629                                  * device list will not be in the same
 630                                  * order as the devices in the selection
 631                                  * array.
 632                                  */
 633                                 for (k = 0; k < numdevs; k++) {
 634                                         if ((*dev_select)[k].position == j) {
 635                                                 found = 1;
 636                                                 break;
 637                                         }
 638                                 }
 639
 640                                 /*
 641                                  * There shouldn't be a case where a device
 642                                  * in the device list is not in the
 643                                  * selection list...but it could happen.
 644                                  */
 645                                 if (found != 1) {
 646                                         fprintf(stderr, "selectdevs: couldn't"
 647                                                 " find %s%d in selection "
 648                                                 "list\n",
 649                                                 devices[j].device_name,
 650                                                 devices[j].unit_number);
 651                                         break;
 652                                 }
 653
 654                                 /*
 655                                  * We do different things based upon the
 656                                  * mode we're in.  If we're in add or only
 657                                  * mode, we go ahead and select this device
 658                                  * if it hasn't already been selected.  If
 659                                  * it has already been selected, we leave
 660                                  * it alone so we don't mess up the
 661                                  * selection ordering.  Manually specified
 662                                  * devices have already been selected, and
 663                                  * they have higher priority than pattern
 664                                  * matched devices.  If we're in remove
 665                                  * mode, we de-select the given device and
 666                                  * decrement the selected count.
 667                                  */
 668                                 switch(select_mode) {
 669                                 case DS_SELECT_ADD:
 670                                 case DS_SELECT_ADDONLY:
 671                                 case DS_SELECT_ONLY:
 672                                         if ((*dev_select)[k].selected != 0)
 673                                                 break;
 674                                         (*dev_select)[k].selected =
 675                                                 ++selection_number;
 676                                         (*num_selected)++;
 677                                         break;
 678                                 case DS_SELECT_REMOVE:
 679                                         (*dev_select)[k].selected = 0;
 680                                         (*num_selected)--;
 681                                         break;
 682                                 }
 683                         }
 684                 }
 685         }
 686
 687         /*
 688          * Here we implement "top" mode.  Devices are sorted in the
 689          * selection array based on two criteria:  whether or not they are
 690          * selected (not selection number, just the fact that they are
 691          * selected!) and the number of bytes in the "bytes" field of the
 692          * selection structure.  The bytes field generally must be kept up
 693          * by the user.  In the future, it may be maintained by library
 694          * functions, but for now the user has to do the work.
 695          *
 696          * At first glance, it may seem wrong that we don't go through and
 697          * select every device in the case where the user hasn't specified
 698          * any devices or patterns.  In fact, though, it won't make any
 699          * difference in the device sorting.  In that particular case (i.e.
 700          * when we're in "add" or "only" mode, and the user hasn't
 701          * specified anything) the first time through no devices will be
 702          * selected, so the only criterion used to sort them will be their
 703          * performance.  The second time through, and every time thereafter,
 704          * all devices will be selected, so again selection won't matter.
 705          */
 706         if (perf_select != 0) {
 707
 708                 /* Sort the device array by throughput  */
 709                 qsort(*dev_select, *num_selections,
 710                       sizeof(struct device_selection),
 711                       compare_select);
 712
 713                 if (*num_selected == 0) {
 714                         /*
 715                          * Here we select every device in the array, if it
 716                          * isn't already selected.  Because the 'selected'
 717                          * variable in the selection array entries contains
 718                          * the selection order, the devstats routine can show
 719                          * the devices that were selected first.
 720                          */
 721                         for (i = 0; i < *num_selections; i++) {
 722                                 if ((*dev_select)[i].selected == 0) {
 723                                         (*dev_select)[i].selected =
 724                                                 ++selection_number;
 725                                         (*num_selected)++;
 726                                 }
 727                         }
 728                 } else {
 729                         selection_number = 0;
 730                         for (i = 0; i < *num_selections; i++) {
 731                                 if ((*dev_select)[i].selected != 0) {
 732                                         (*dev_select)[i].selected =
 733                                                 ++selection_number;
 734                                 }
 735                         }
 736                 }
 737         }
 738
 739         /*
 740          * If we're in the "add" selection mode and if we haven't already
 741          * selected maxshowdevs number of devices, go through the array and
 742          * select any unselected devices.  If we're in "only" mode, we
 743          * obviously don't want to select anything other than what the user
 744          * specifies.  If we're in "remove" mode, it probably isn't a good
 745          * idea to go through and select any more devices, since we might
 746          * end up selecting something that the user wants removed.  Through
 747          * more complicated logic, we could actually figure this out, but
 748          * that would probably require combining this loop with the various
 749          * selections loops above.
 750          */
 751         if ((select_mode == DS_SELECT_ADD) && (*num_selected < maxshowdevs)) {
 752                 for (i = 0; i < *num_selections; i++)
 753                         if ((*dev_select)[i].selected == 0) {
 754                                 (*dev_select)[i].selected = ++selection_number;
 755                                 (*num_selected)++;
 756                         }
 757         }
 758
 759         /*
 760          * Look at the number of devices that have been selected.  If it
 761          * has changed, set the changed variable.  Otherwise, if we've
 762          * made a backup of the selection list, compare it to the current
 763          * selection list to see if the selected devices have changed.
 764          */
 765         if ((changed == 0) && (old_num_selected != *num_selected))
 766                 changed = 1;
 767         else if ((changed == 0) && (old_dev_select != NULL)) {
 768                 /*
 769                  * Now we go through the selection list and we look at
 770                  * it three different ways.
 771                  */
 772                 for (i = 0; (i < *num_selections) && (changed == 0) &&
 773                      (i < old_num_selections); i++) {
 774                         /*
 775                          * If the device at index i in both the new and old
 776                          * selection arrays has the same device number and
 777                          * selection status, it hasn't changed.  We
 778                          * continue on to the next index.
 779                          */
 780                         if (((*dev_select)[i].device_number ==
 781                              old_dev_select[i].device_number)
 782                          && ((*dev_select)[i].selected ==
 783                              old_dev_select[i].selected))
 784                                 continue;
 785
 786                         /*
 787                          * Now, if we're still going through the if
 788                          * statement, the above test wasn't true.  So we
 789                          * check here to see if the device at index i in
 790                          * the current array is the same as the device at
 791                          * index i in the old array.  If it is, that means
 792                          * that its selection number has changed.  Set
 793                          * changed to 1 and exit the loop.
 794                          */
 795                         else if ((*dev_select)[i].device_number ==
 796                                   old_dev_select[i].device_number) {
 797                                 changed = 1;
 798                                 break;
 799                         }
 800                         /*
 801                          * If we get here, then the device at index i in
 802                          * the current array isn't the same device as the
 803                          * device at index i in the old array.
 804                          */
 805                         else {
 806                                 found = 0;
 807
 808                                 /*
 809                                  * Search through the old selection array
 810                                  * looking for a device with the same
 811                                  * device number as the device at index i
 812                                  * in the current array.  If the selection
 813                                  * status is the same, then we mark it as
 814                                  * found.  If the selection status isn't
 815                                  * the same, we break out of the loop.
 816                                  * Since found isn't set, changed will be
 817                                  * set to 1 below.
 818                                  */
 819                                 for (j = 0; j < old_num_selections; j++) {
 820                                         if (((*dev_select)[i].device_number ==
 821                                               old_dev_select[j].device_number)
 822                                          && ((*dev_select)[i].selected ==
 823                                               old_dev_select[j].selected)){
 824                                                 found = 1;
 825                                                 break;
 826                                         }
 827                                         else if ((*dev_select)[i].device_number
 828                                             == old_dev_select[j].device_number)
 829                                                 break;
 830                                 }
 831                                 if (found == 0)
 832                                         changed = 1;
 833                         }
 834                 }
 835         }
 836         if (old_dev_select != NULL)
 837                 free(old_dev_select);
 838
 839         return(changed);
 840 }
 841
 842 /*
 843  * Comparison routine for qsort() above.  Note that the comparison here is
 844  * backwards -- generally, it should return a value to indicate whether
 845  * arg1 is <, =, or > arg2.  Instead, it returns the opposite.  The reason
 846  * it returns the opposite is so that the selection array will be sorted in
 847  * order of decreasing performance.  We sort on two parameters.  The first
 848  * sort key is whether or not one or the other of the devices in question
 849  * has been selected.  If one of them has, and the other one has not, the
 850  * selected device is automatically more important than the unselected
 851  * device.  If neither device is selected, we judge the devices based upon
 852  * performance.
 853  */
 854 static int
 855 compare_select(const void *arg1, const void *arg2)
 856 {
 857         if ((((const struct device_selection *)arg1)->selected)
 858          && (((const struct device_selection *)arg2)->selected == 0))
 859                 return(-1);
 860         else if ((((const struct device_selection *)arg1)->selected == 0)
 861               && (((const struct device_selection *)arg2)->selected))
 862                 return(1);
 863         else if (((const struct device_selection *)arg2)->bytes <
 864                  ((const struct device_selection *)arg1)->bytes)
 865                 return(-1);
 866         else if (((const struct device_selection *)arg2)->bytes >
 867                  ((const struct device_selection *)arg1)->bytes)
 868                 return(1);
 869         else
 870                 return(0);
 871 }
 872
 873 /*
 874  * Take a string with the general format "arg1,arg2,arg3", and build a
 875  * device matching expression from it.
 876  */
 877 int
 878 buildmatch(const char *match_str, struct devstat_match **matches,
 879            int *num_matches)
 880 {
 881         char *tstr[5];
 882         char **tempstr;
 883         char *matchbuf_orig;    /* strdup of match_str */
 884         char *matchbuf;         /* allow strsep to clobber */
 885         int num_args;
 886         int i, j;
 887         int retval = -1;
 888
 889         /* We can't do much without a string to parse */
 890         if (match_str == NULL) {
 891                 sprintf(devstat_errbuf, "%s: no match expression", __func__);
 892                 return(-1);
 893         }
 894
 895         /*
 896          * Break the (comma delimited) input string out into separate strings.
 897          * strsep is destructive, so copy the string first.
 898          */
 899         matchbuf = matchbuf_orig = strdup(match_str);
 900         if (matchbuf == NULL) {
 901                 sprintf(devstat_errbuf, "%s: out of memory", __func__);
 902                 return(-1);
 903         }
 904         for (tempstr = tstr, num_args  = 0;
 905              (*tempstr = strsep(&matchbuf, ",")) != NULL && (num_args < 5);
 906              num_args++)
 907                 if (**tempstr != '\0')
 908                         if (++tempstr >= &tstr[5])
 909                                 break;
 910
 911         /* The user gave us too many type arguments */
 912         if (num_args > 3) {
 913                 sprintf(devstat_errbuf, "%s: too many type arguments",
 914                         __func__);
 915                 goto cleanup;
 916         }
 917
 918         /*
 919          * Since you can't realloc a pointer that hasn't been malloced
 920          * first, we malloc first and then realloc.
 921          */
 922         if (*num_matches == 0)
 923                 *matches = (struct devstat_match *)malloc(
 924                            sizeof(struct devstat_match));
 925         else
 926                 *matches = (struct devstat_match *)realloc(*matches,
 927                           sizeof(struct devstat_match) * (*num_matches + 1));
 928
 929         /* Make sure the current entry is clear */
 930         bzero(&matches[0][*num_matches], sizeof(struct devstat_match));
 931
 932         /*
 933          * Step through the arguments the user gave us and build a device
 934          * matching expression from them.
 935          */
 936         for (i = 0; i < num_args; i++) {
 937                 char *tempstr2, *tempstr3;
 938
 939                 /*
 940                  * Get rid of leading white space.
 941                  */
 942                 tempstr2 = tstr[i];
 943                 while (isspace(*tempstr2) && (*tempstr2 != '\0'))
 944                         tempstr2++;
 945
 946                 /*
 947                  * Get rid of trailing white space.
 948                  */
 949                 tempstr3 = &tempstr2[strlen(tempstr2) - 1];
 950
 951                 while ((*tempstr3 != '\0') && (tempstr3 > tempstr2)
 952                     && (isspace(*tempstr3))) {
 953                         *tempstr3 = '\0';
 954                         tempstr3--;
 955                 }
 956
 957                 /*
 958                  * Go through the match table comparing the user's
 959                  * arguments to known device types, interfaces, etc.
 960                  */
 961                 for (j = 0; match_table[j].match_str != NULL; j++) {
 962                         /*
 963                          * We do case-insensitive matching, in case someone
 964                          * wants to enter "SCSI" instead of "scsi" or
 965                          * something like that.  Only compare as many
 966                          * characters as are in the string in the match
 967                          * table.  This should help if someone tries to use
 968                          * a super-long match expression.
 969                          */
 970                         if (strncasecmp(tempstr2, match_table[j].match_str,
 971                             strlen(match_table[j].match_str)) == 0) {
 972                                 /*
 973                                  * Make sure the user hasn't specified two
 974                                  * items of the same type, like "da" and
 975                                  * "cd".  One device cannot be both.
 976                                  */
 977                                 if (((*matches)[*num_matches].match_fields &
 978                                     match_table[j].match_field) != 0) {
 979                                         sprintf(devstat_errbuf,
 980                                                 "%s: cannot have more than "
 981                                                 "one match item in a single "
 982                                                 "category", __func__);
 983                                         goto cleanup;
 984                                 }
 985                                 /*
 986                                  * If we've gotten this far, we have a
 987                                  * winner.  Set the appropriate fields in
 988                                  * the match entry.
 989                                  */
 990                                 (*matches)[*num_matches].match_fields |=
 991                                         match_table[j].match_field;
 992                                 (*matches)[*num_matches].device_type |=
 993                                         match_table[j].type;
 994                                 (*matches)[*num_matches].num_match_categories++;
 995                                 break;
 996                         }
 997                 }
 998                 /*
 999                  * We should have found a match in the above for loop.  If
1000                  * not, that means the user entered an invalid device type
1001                  * or interface.
1002                  */
1003                 if ((*matches)[*num_matches].num_match_categories != (i + 1)) {
1004                         snprintf(devstat_errbuf, sizeof(devstat_errbuf),
1005                                 "%s: unknown match item \"%s\"", __func__,
1006                                 tstr[i]);
1007                         goto cleanup;
1008                 }
1009         }
1010
1011         (*num_matches)++;
1012         retval = 0;
1013 cleanup:
1014         free(matchbuf_orig);
1015         return(retval);
1016 }
1017
1018 /*
1019  * Compute a number of device statistics.  Only one field is mandatory, and
1020  * that is "current".  Everything else is optional.  The caller passes in
1021  * pointers to variables to hold the various statistics he desires.  If he
1022  * doesn't want a particular staistic, he should pass in a NULL pointer.
1023  * Return values:
1024  * 0   -- success
1025  * -1  -- failure
1026  */
1027 int
1028 compute_stats(struct devstat *current, struct devstat *previous,
1029               long double etime, u_int64_t *total_bytes,
1030               u_int64_t *total_transfers, u_int64_t *total_blocks,
1031               long double *kb_per_transfer, long double *transfers_per_second,
1032               long double *mb_per_second, long double *blocks_per_second,
1033               long double *ms_per_transaction)
1034 {
1035         u_int64_t totalbytes, totaltransfers, totalblocks;
1036
1037         /*
1038          * current is the only mandatory field.
1039          */
1040         if (current == NULL) {
1041                 sprintf(devstat_errbuf, "%s: current stats structure was NULL",
1042                         __func__);
1043                 return(-1);
1044         }
1045
1046         totalbytes = (current->bytes_written + current->bytes_read) -
1047                      ((previous) ? (previous->bytes_written +
1048                                     previous->bytes_read) : 0);
1049
1050         if (total_bytes)
1051                 *total_bytes = totalbytes;
1052
1053         totaltransfers = (current->num_reads +
1054                           current->num_writes +
1055                           current->num_other) -
1056                          ((previous) ?
1057                           (previous->num_reads +
1058                            previous->num_writes +
1059                            previous->num_other) : 0);
1060         if (total_transfers)
1061                 *total_transfers = totaltransfers;
1062
1063         if (transfers_per_second) {
1064                 if (etime > 0.0) {
1065                         *transfers_per_second = totaltransfers;
1066                         *transfers_per_second /= etime;
1067                 } else
1068                         *transfers_per_second = 0.0;
1069         }
1070
1071         if (kb_per_transfer) {
1072                 *kb_per_transfer = totalbytes;
1073                 *kb_per_transfer /= 1024;
1074                 if (totaltransfers > 0)
1075                         *kb_per_transfer /= totaltransfers;
1076                 else
1077                         *kb_per_transfer = 0.0;
1078         }
1079
1080         if (mb_per_second) {
1081                 *mb_per_second = totalbytes;
1082                 *mb_per_second /= 1024 * 1024;
1083                 if (etime > 0.0)
1084                         *mb_per_second /= etime;
1085                 else
1086                         *mb_per_second = 0.0;
1087         }
1088
1089         totalblocks = totalbytes;
1090         if (current->block_size > 0)
1091                 totalblocks /= current->block_size;
1092         else
1093                 totalblocks /= 512;
1094
1095         if (total_blocks)
1096                 *total_blocks = totalblocks;
1097
1098         if (blocks_per_second) {
1099                 *blocks_per_second = totalblocks;
1100                 if (etime > 0.0)
1101                         *blocks_per_second /= etime;
1102                 else
1103                         *blocks_per_second = 0.0;
1104         }
1105
1106         if (ms_per_transaction) {
1107                 if (totaltransfers > 0) {
1108                         *ms_per_transaction = etime;
1109                         *ms_per_transaction /= totaltransfers;
1110                         *ms_per_transaction *= 1000;
1111                 } else
1112                         *ms_per_transaction = 0.0;
1113         }
1114
1115         return(0);
1116 }
1117
1118 int
1119 compute_stats_read(struct devstat *current, struct devstat *previous,
1120               long double etime, u_int64_t *total_bytes,
1121               u_int64_t *total_transfers, u_int64_t *total_blocks,
1122               long double *kb_per_transfer, long double *transfers_per_second,
1123               long double *mb_per_second, long double *blocks_per_second,
1124               long double *ms_per_transaction)
1125 {
1126         u_int64_t totalbytes, totaltransfers, totalblocks;
1127
1128         /*
1129          * current is the only mandatory field.
1130          */
1131         if (current == NULL) {
1132                 sprintf(devstat_errbuf, "%s: current stats structure was NULL",
1133                         __func__);
1134                 return(-1);
1135         }
1136
1137         totalbytes = current->bytes_read -
1138                      (previous ? previous->bytes_read : 0);
1139
1140         if (total_bytes)
1141                 *total_bytes = totalbytes;
1142
1143         totaltransfers = current->num_reads -
1144                          (previous ? previous->num_reads : 0);
1145         if (total_transfers)
1146                 *total_transfers = totaltransfers;
1147
1148         if (transfers_per_second) {
1149                 if (etime > 0.0) {
1150                         *transfers_per_second = totaltransfers;
1151                         *transfers_per_second /= etime;
1152                 } else
1153                         *transfers_per_second = 0.0;
1154         }
1155
1156         if (kb_per_transfer) {
1157                 *kb_per_transfer = totalbytes;
1158                 *kb_per_transfer /= 1024;
1159                 if (totaltransfers > 0)
1160                         *kb_per_transfer /= totaltransfers;
1161                 else
1162                         *kb_per_transfer = 0.0;
1163         }
1164
1165         if (mb_per_second) {
1166                 *mb_per_second = totalbytes;
1167                 *mb_per_second /= 1024 * 1024;
1168                 if (etime > 0.0)
1169                         *mb_per_second /= etime;
1170                 else
1171                         *mb_per_second = 0.0;
1172         }
1173
1174         totalblocks = totalbytes;
1175         if (current->block_size > 0)
1176                 totalblocks /= current->block_size;
1177         else
1178                 totalblocks /= 512;
1179
1180         if (total_blocks)
1181                 *total_blocks = totalblocks;
1182
1183         if (blocks_per_second) {
1184                 *blocks_per_second = totalblocks;
1185                 if (etime > 0.0)
1186                         *blocks_per_second /= etime;
1187                 else
1188                         *blocks_per_second = 0.0;
1189         }
1190
1191         if (ms_per_transaction) {
1192                 if (totaltransfers > 0) {
1193                         *ms_per_transaction = etime;
1194                         *ms_per_transaction /= totaltransfers;
1195                         *ms_per_transaction *= 1000;
1196                 } else
1197                         *ms_per_transaction = 0.0;
1198         }
1199
1200         return(0);
1201 }
1202
1203 int
1204 compute_stats_write(struct devstat *current, struct devstat *previous,
1205               long double etime, u_int64_t *total_bytes,
1206               u_int64_t *total_transfers, u_int64_t *total_blocks,
1207               long double *kb_per_transfer, long double *transfers_per_second,
1208               long double *mb_per_second, long double *blocks_per_second,
1209               long double *ms_per_transaction)
1210 {
1211         u_int64_t totalbytes, totaltransfers, totalblocks;
1212
1213         /*
1214          * current is the only mandatory field.
1215          */
1216         if (current == NULL) {
1217                 sprintf(devstat_errbuf, "%s: current stats structure was NULL",
1218                         __func__);
1219                 return(-1);
1220         }
1221
1222         totalbytes = current->bytes_written -
1223                      (previous ? previous->bytes_written : 0);
1224
1225         if (total_bytes)
1226                 *total_bytes = totalbytes;
1227
1228         totaltransfers = current->num_writes -
1229                          (previous ? previous->num_writes : 0);
1230         if (total_transfers)
1231                 *total_transfers = totaltransfers;
1232
1233         if (transfers_per_second) {
1234                 if (etime > 0.0) {
1235                         *transfers_per_second = totaltransfers;
1236                         *transfers_per_second /= etime;
1237                 } else
1238                         *transfers_per_second = 0.0;
1239         }
1240
1241         if (kb_per_transfer) {
1242                 *kb_per_transfer = totalbytes;
1243                 *kb_per_transfer /= 1024;
1244                 if (totaltransfers > 0)
1245                         *kb_per_transfer /= totaltransfers;
1246                 else
1247                         *kb_per_transfer = 0.0;
1248         }
1249
1250         if (mb_per_second) {
1251                 *mb_per_second = totalbytes;
1252                 *mb_per_second /= 1024 * 1024;
1253                 if (etime > 0.0)
1254                         *mb_per_second /= etime;
1255                 else
1256                         *mb_per_second = 0.0;
1257         }
1258
1259         totalblocks = totalbytes;
1260         if (current->block_size > 0)
1261                 totalblocks /= current->block_size;
1262         else
1263                 totalblocks /= 512;
1264
1265         if (total_blocks)
1266                 *total_blocks = totalblocks;
1267
1268         if (blocks_per_second) {
1269                 *blocks_per_second = totalblocks;
1270                 if (etime > 0.0)
1271                         *blocks_per_second /= etime;
1272                 else
1273                         *blocks_per_second = 0.0;
1274         }
1275
1276         if (ms_per_transaction) {
1277                 if (totaltransfers > 0) {
1278                         *ms_per_transaction = etime;
1279                         *ms_per_transaction /= totaltransfers;
1280                         *ms_per_transaction *= 1000;
1281                 } else
1282                         *ms_per_transaction = 0.0;
1283         }
1284
1285         return(0);
1286 }
1287
1288 long double
1289 compute_etime(struct timeval cur_time, struct timeval prev_time)
1290 {
1291         struct timeval busy_time;
1292         u_int64_t busy_usec;
1293         long double etime;
1294
1295         timersub(&cur_time, &prev_time, &busy_time);
1296
1297         busy_usec = busy_time.tv_sec;
1298         busy_usec *= 1000000;
1299         busy_usec += busy_time.tv_usec;
1300         etime = busy_usec;
1301         etime /= 1000000;
1302
1303         return(etime);
1304 }