src/fs/ufs/UFSSwapDir.cc

   1 /*
   2  * Copyright (C) 1996-2015 The Squid Software Foundation and contributors
   3  *
   4  * Squid software is distributed under GPLv2+ license and includes
   5  * contributions from numerous individuals and organizations.
   6  * Please see the COPYING and CONTRIBUTORS files for details.
   7  */
   8
   9 /* DEBUG: section 47    Store Directory Routines */
  10
  11 #define CLEAN_BUF_SZ 16384
  12
  13 #include "squid.h"
  14 #include "cache_cf.h"
  15 #include "ConfigOption.h"
  16 #include "disk.h"
  17 #include "DiskIO/DiskIOModule.h"
  18 #include "DiskIO/DiskIOStrategy.h"
  19 #include "fde.h"
  20 #include "FileMap.h"
  21 #include "globals.h"
  22 #include "Parsing.h"
  23 #include "RebuildState.h"
  24 #include "SquidConfig.h"
  25 #include "SquidMath.h"
  26 #include "SquidTime.h"
  27 #include "StatCounters.h"
  28 #include "store_key_md5.h"
  29 #include "StoreSearchUFS.h"
  30 #include "StoreSwapLogData.h"
  31 #include "tools.h"
  32 #include "UFSSwapDir.h"
  33
  34 #include <cerrno>
  35 #include <cmath>
  36 #include <random>
  37 #if HAVE_SYS_STAT_H
  38 #include <sys/stat.h>
  39 #endif
  40
  41 int Fs::Ufs::UFSSwapDir::NumberOfUFSDirs = 0;
  42 int *Fs::Ufs::UFSSwapDir::UFSDirToGlobalDirMapping = NULL;
  43
  44 class UFSCleanLog : public SwapDir::CleanLog
  45 {
  46
  47 public:
  48     UFSCleanLog(SwapDir *);
  49     /** Get the next entry that is a candidate for clean log writing
  50      */
  51     virtual const StoreEntry *nextEntry();
  52     /** "write" an entry to the clean log file.
  53      */
  54     virtual void write(StoreEntry const &);
  55     char *cur;
  56     char *newLog;
  57     char *cln;
  58     char *outbuf;
  59     off_t outbuf_offset;
  60     int fd;
  61     RemovalPolicyWalker *walker;
  62     SwapDir *sd;
  63 };
  64
  65 UFSCleanLog::UFSCleanLog(SwapDir *aSwapDir) :
  66     cur(NULL), newLog(NULL), cln(NULL), outbuf(NULL),
  67     outbuf_offset(0), fd(-1),walker(NULL), sd(aSwapDir)
  68 {}
  69
  70 const StoreEntry *
  71 UFSCleanLog::nextEntry()
  72 {
  73     const StoreEntry *entry = NULL;
  74
  75     if (walker)
  76         entry = walker->Next(walker);
  77
  78     return entry;
  79 }
  80
  81 void
  82 UFSCleanLog::write(StoreEntry const &e)
  83 {
  84     StoreSwapLogData s;
  85     static size_t ss = sizeof(StoreSwapLogData);
  86     s.op = (char) SWAP_LOG_ADD;
  87     s.swap_filen = e.swap_filen;
  88     s.timestamp = e.timestamp;
  89     s.lastref = e.lastref;
  90     s.expires = e.expires;
  91     s.lastmod = e.lastmod;
  92     s.swap_file_sz = e.swap_file_sz;
  93     s.refcount = e.refcount;
  94     s.flags = e.flags;
  95     memcpy(&s.key, e.key, SQUID_MD5_DIGEST_LENGTH);
  96     s.finalize();
  97     memcpy(outbuf + outbuf_offset, &s, ss);
  98     outbuf_offset += ss;
  99     /* buffered write */
 100
 101     if (outbuf_offset + ss >= CLEAN_BUF_SZ) {
 102         if (FD_WRITE_METHOD(fd, outbuf, outbuf_offset) < 0) {
 103             /* XXX This error handling should probably move up to the caller */
 104             debugs(50, DBG_CRITICAL, HERE << newLog << ": write: " << xstrerror());
 105             debugs(50, DBG_CRITICAL, HERE << "Current swap logfile not replaced.");
 106             file_close(fd);
 107             fd = -1;
 108             unlink(newLog);
 109             sd->cleanLog = NULL;
 110             delete this;
 111             return;
 112         }
 113
 114         outbuf_offset = 0;
 115     }
 116 }
 117
 118 bool
 119 Fs::Ufs::UFSSwapDir::canStore(const StoreEntry &e, int64_t diskSpaceNeeded, int &load) const
 120 {
 121     if (!SwapDir::canStore(e, diskSpaceNeeded, load))
 122         return false;
 123
 124     if (IO->shedLoad())
 125         return false;
 126
 127     load = IO->load();
 128     return true;
 129 }
 130
 131 static void
 132 FreeObject(void *address)
 133 {
 134     StoreSwapLogData *anObject = static_cast <StoreSwapLogData *>(address);
 135     delete anObject;
 136 }
 137
 138 static int
 139 rev_int_sort(const void *A, const void *B)
 140 {
 141     const int *i1 = (const int *)A;
 142     const int *i2 = (const int *)B;
 143     return *i2 - *i1;
 144 }
 145
 146 void
 147 Fs::Ufs::UFSSwapDir::parseSizeL1L2()
 148 {
 149     int i = GetInteger();
 150     if (i <= 0)
 151         fatal("UFSSwapDir::parseSizeL1L2: invalid size value");
 152
 153     const uint64_t size = static_cast<uint64_t>(i) << 20; // MBytes to Bytes
 154
 155     /* just reconfigure it */
 156     if (reconfiguring) {
 157         if (size == maxSize())
 158             debugs(3, 2, "Cache dir '" << path << "' size remains unchanged at " << i << " MB");
 159         else
 160             debugs(3, DBG_IMPORTANT, "Cache dir '" << path << "' size changed to " << i << " MB");
 161     }
 162
 163     max_size = size;
 164
 165     l1 = GetInteger();
 166
 167     if (l1 <= 0)
 168         fatal("UFSSwapDir::parseSizeL1L2: invalid level 1 directories value");
 169
 170     l2 = GetInteger();
 171
 172     if (l2 <= 0)
 173         fatal("UFSSwapDir::parseSizeL1L2: invalid level 2 directories value");
 174 }
 175
 176 void
 177 Fs::Ufs::UFSSwapDir::reconfigure()
 178 {
 179     parseSizeL1L2();
 180     parseOptions(1);
 181 }
 182
 183 void
 184 Fs::Ufs::UFSSwapDir::parse (int anIndex, char *aPath)
 185 {
 186     index = anIndex;
 187     path = xstrdup(aPath);
 188
 189     parseSizeL1L2();
 190
 191     /* Initialise replacement policy stuff */
 192     repl = createRemovalPolicy(Config.replPolicy);
 193
 194     parseOptions(0);
 195 }
 196
 197 void
 198 Fs::Ufs::UFSSwapDir::changeIO(DiskIOModule *module)
 199 {
 200     DiskIOStrategy *anIO = module->createStrategy();
 201     safe_free(ioType);
 202     ioType = xstrdup(module->type());
 203
 204     delete IO->io;
 205     IO->io = anIO;
 206     /* Change the IO Options */
 207
 208     if (currentIOOptions && currentIOOptions->options.size() > 2) {
 209         delete currentIOOptions->options.back();
 210         currentIOOptions->options.pop_back();
 211     }
 212
 213     /* TODO: factor out these 4 lines */
 214     ConfigOption *ioOptions = IO->io->getOptionTree();
 215
 216     if (currentIOOptions && ioOptions)
 217         currentIOOptions->options.push_back(ioOptions);
 218 }
 219
 220 bool
 221 Fs::Ufs::UFSSwapDir::optionIOParse(char const *option, const char *value, int isaReconfig)
 222 {
 223     if (strcmp(option, "IOEngine") != 0)
 224         return false;
 225
 226     if (isaReconfig)
 227         /* silently ignore this */
 228         return true;
 229
 230     if (!value)
 231         self_destruct();
 232
 233     DiskIOModule *module = DiskIOModule::Find(value);
 234
 235     if (!module)
 236         self_destruct();
 237
 238     changeIO(module);
 239
 240     return true;
 241 }
 242
 243 void
 244 Fs::Ufs::UFSSwapDir::optionIODump(StoreEntry * e) const
 245 {
 246     storeAppendPrintf(e, " IOEngine=%s", ioType);
 247 }
 248
 249 ConfigOption *
 250 Fs::Ufs::UFSSwapDir::getOptionTree() const
 251 {
 252     ConfigOption *parentResult = SwapDir::getOptionTree();
 253
 254     if (currentIOOptions == NULL)
 255         currentIOOptions = new ConfigOptionVector();
 256
 257     currentIOOptions->options.push_back(parentResult);
 258
 259     currentIOOptions->options.push_back(new ConfigOptionAdapter<UFSSwapDir>(*const_cast<UFSSwapDir *>(this), &UFSSwapDir::optionIOParse, &UFSSwapDir::optionIODump));
 260
 261     if (ConfigOption *ioOptions = IO->io->getOptionTree())
 262         currentIOOptions->options.push_back(ioOptions);
 263
 264     ConfigOption* result = currentIOOptions;
 265
 266     currentIOOptions = NULL;
 267
 268     return result;
 269 }
 270
 271 void
 272 Fs::Ufs::UFSSwapDir::init()
 273 {
 274     debugs(47, 3, HERE << "Initialising UFS SwapDir engine.");
 275     /* Parsing must be finished by now - force to NULL, don't delete */
 276     currentIOOptions = NULL;
 277     static int started_clean_event = 0;
 278     static const char *errmsg =
 279         "\tFailed to verify one of the swap directories, Check cache.log\n"
 280         "\tfor details.  Run 'squid -z' to create swap directories\n"
 281         "\tif needed, or if running Squid for the first time.";
 282     IO->init();
 283
 284     if (verifyCacheDirs())
 285         fatal(errmsg);
 286
 287     openLog();
 288
 289     rebuild();
 290
 291     if (!started_clean_event) {
 292         eventAdd("UFS storeDirClean", CleanEvent, NULL, 15.0, 1);
 293         started_clean_event = 1;
 294     }
 295
 296     (void) storeDirGetBlkSize(path, &fs.blksize);
 297 }
 298
 299 void
 300 Fs::Ufs::UFSSwapDir::create()
 301 {
 302     debugs(47, 3, "Creating swap space in " << path);
 303     createDirectory(path, 0);
 304     createSwapSubDirs();
 305 }
 306
 307 Fs::Ufs::UFSSwapDir::UFSSwapDir(char const *aType, const char *anIOType) :
 308     SwapDir(aType),
 309     IO(NULL),
 310     fsdata(NULL),
 311     map(new FileMap()),
 312     suggest(0),
 313     l1(16),
 314     l2(256),
 315     swaplog_fd(-1),
 316     currentIOOptions(new ConfigOptionVector()),
 317     ioType(xstrdup(anIOType)),
 318     cur_size(0),
 319     n_disk_objects(0)
 320 {
 321     /* modulename is only set to disk modules that are built, by configure,
 322      * so the Find call should never return NULL here.
 323      */
 324     IO = new Fs::Ufs::UFSStrategy(DiskIOModule::Find(anIOType)->createStrategy());
 325 }
 326
 327 Fs::Ufs::UFSSwapDir::~UFSSwapDir()
 328 {
 329     if (swaplog_fd > -1) {
 330         file_close(swaplog_fd);
 331         swaplog_fd = -1;
 332     }
 333     xfree(ioType);
 334     delete map;
 335     delete IO;
 336     delete currentIOOptions;
 337 }
 338
 339 void
 340 Fs::Ufs::UFSSwapDir::dumpEntry(StoreEntry &e) const
 341 {
 342     debugs(47, DBG_CRITICAL, HERE << "FILENO "<< std::setfill('0') << std::hex << std::uppercase << std::setw(8) << e.swap_filen);
 343     debugs(47, DBG_CRITICAL, HERE << "PATH " << fullPath(e.swap_filen, NULL)   );
 344     e.dump(0);
 345 }
 346
 347 bool
 348 Fs::Ufs::UFSSwapDir::doubleCheck(StoreEntry & e)
 349 {
 350
 351     struct stat sb;
 352
 353     if (::stat(fullPath(e.swap_filen, NULL), &sb) < 0) {
 354         debugs(47, DBG_CRITICAL, HERE << "WARNING: Missing swap file");
 355         dumpEntry(e);
 356         return true;
 357     }
 358
 359     if ((off_t)e.swap_file_sz != sb.st_size) {
 360         debugs(47, DBG_CRITICAL, HERE << "WARNING: Size Mismatch. Entry size: "
 361                << e.swap_file_sz << ", file size: " << sb.st_size);
 362         dumpEntry(e);
 363         return true;
 364     }
 365
 366     return false;
 367 }
 368
 369 void
 370 Fs::Ufs::UFSSwapDir::statfs(StoreEntry & sentry) const
 371 {
 372     int totl_kb = 0;
 373     int free_kb = 0;
 374     int totl_in = 0;
 375     int free_in = 0;
 376     int x;
 377     storeAppendPrintf(&sentry, "First level subdirectories: %d\n", l1);
 378     storeAppendPrintf(&sentry, "Second level subdirectories: %d\n", l2);
 379     storeAppendPrintf(&sentry, "Maximum Size: %" PRIu64 " KB\n", maxSize() >> 10);
 380     storeAppendPrintf(&sentry, "Current Size: %.2f KB\n", currentSize() / 1024.0);
 381     storeAppendPrintf(&sentry, "Percent Used: %0.2f%%\n",
 382                       Math::doublePercent(currentSize(), maxSize()));
 383     storeAppendPrintf(&sentry, "Filemap bits in use: %d of %d (%d%%)\n",
 384                       map->numFilesInMap(), map->capacity(),
 385                       Math::intPercent(map->numFilesInMap(), map->capacity()));
 386     x = storeDirGetUFSStats(path, &totl_kb, &free_kb, &totl_in, &free_in);
 387
 388     if (0 == x) {
 389         storeAppendPrintf(&sentry, "Filesystem Space in use: %d/%d KB (%d%%)\n",
 390                           totl_kb - free_kb,
 391                           totl_kb,
 392                           Math::intPercent(totl_kb - free_kb, totl_kb));
 393         storeAppendPrintf(&sentry, "Filesystem Inodes in use: %d/%d (%d%%)\n",
 394                           totl_in - free_in,
 395                           totl_in,
 396                           Math::intPercent(totl_in - free_in, totl_in));
 397     }
 398
 399     storeAppendPrintf(&sentry, "Flags:");
 400
 401     if (flags.selected)
 402         storeAppendPrintf(&sentry, " SELECTED");
 403
 404     if (flags.read_only)
 405         storeAppendPrintf(&sentry, " READ-ONLY");
 406
 407     storeAppendPrintf(&sentry, "\n");
 408
 409     IO->statfs(sentry);
 410 }
 411
 412 void
 413 Fs::Ufs::UFSSwapDir::maintain()
 414 {
 415     /* TODO: possible options for improvement;
 416      *
 417      * Note that too much aggression here is not good. It means that disk
 418      * controller is getting a long queue of removals to act on, along
 419      * with its regular I/O queue, and that client traffic is 'paused'
 420      * and growing the network I/O queue as well while the scan happens.
 421      * Possibly bad knock-on effects as Squid catches up on all that.
 422      *
 423      * Bug 2448 may have been a sign of what can wrong. At the least it
 424      * provides a test case for aggression effects in overflow conditions.
 425      *
 426      * - base removal limit on space saved, instead of count ?
 427      *
 428      * - base removal rate on a traffic speed counter ?
 429      *   as the purge took up more time out of the second it would grow to
 430      *   a graceful full pause
 431      *
 432      * - pass out a value to cause another event to be scheduled immediately
 433      *   instead of waiting a whole second more ?
 434      *   knock on; schedule less if all caches are under low-water
 435      *
 436      * - admin configurable removal rate or count ?
 437      *   the current numbers are arbitrary, config helps with experimental
 438      *   trials and future-proofing the install base.
 439      *   we also have this indirectly by shifting the relative positions
 440      *   of low-, high- water and the total capacity limit.
 441      */
 442
 443     /* We can't delete objects while rebuilding swap */
 444     /* XXX FIXME each store should start maintaining as it comes online. */
 445     if (StoreController::store_dirs_rebuilding) {
 446         debugs(47, DBG_IMPORTANT, StoreController::store_dirs_rebuilding << " cache_dir still rebuilding. Skip GC for " << path);
 447         return;
 448     }
 449
 450     // minSize() is swap_low_watermark in bytes
 451     const uint64_t lowWaterSz = minSize();
 452
 453     if (currentSize() < lowWaterSz) {
 454         debugs(47, 2, "space still available in " << path);
 455         return;
 456     }
 457
 458     // maxSize() is cache_dir total size in bytes
 459     const uint64_t highWaterSz = ((maxSize() * Config.Swap.highWaterMark) / 100);
 460
 461     // f is percentage of 'gap' filled between low- and high-water.
 462     // Used to reduced purge rate when between water markers, and
 463     // to multiply it more agressively the further above high-water
 464     // it reaches. But in a graceful linear growth curve.
 465     double f = 1.0;
 466     if (highWaterSz > lowWaterSz) {
 467         // might be equal. n/0 is bad.
 468         f = (double) (currentSize() - lowWaterSz) / (highWaterSz - lowWaterSz);
 469     }
 470
 471     // how deep to look for a single object that can be removed
 472     int max_scan = (int) (f * 400.0 + 100.0);
 473
 474     // try to purge only this many objects this cycle.
 475     int max_remove = (int) (f * 300.0 + 20.0);
 476
 477     /*
 478      * This is kinda cheap, but so we need this priority hack?
 479      */
 480     debugs(47, 3, "f=" << f << ", max_scan=" << max_scan << ", max_remove=" << max_remove);
 481
 482     RemovalPurgeWalker *walker = repl->PurgeInit(repl, max_scan);
 483
 484     int removed = 0;
 485     // only purge while above low-water
 486     while (currentSize() >= lowWaterSz) {
 487
 488         // stop if we reached max removals for this cycle,
 489         // Bug 2448 may be from this not clearing enough,
 490         // but it predates the current algorithm so not sure
 491         if (removed >= max_remove)
 492             break;
 493
 494         StoreEntry *e = walker->Next(walker);
 495
 496         // stop if all objects are locked / in-use,
 497         // or the cache is empty
 498         if (!e)
 499             break;      /* no more objects */
 500
 501         ++removed;
 502
 503         e->release();
 504     }
 505
 506     walker->Done(walker);
 507     debugs(47, (removed ? 2 : 3), path <<
 508            " removed " << removed << "/" << max_remove << " f=" <<
 509            std::setprecision(4) << f << " max_scan=" << max_scan);
 510
 511     // what if cache is still over the high watermark ?
 512     // Store::Maintain() schedules another purge in 1 second.
 513 }
 514
 515 void
 516 Fs::Ufs::UFSSwapDir::reference(StoreEntry &e)
 517 {
 518     debugs(47, 3, HERE << "referencing " << &e << " " <<
 519            e.swap_dirn << "/" << e.swap_filen);
 520
 521     if (repl->Referenced)
 522         repl->Referenced(repl, &e, &e.repl);
 523 }
 524
 525 bool
 526 Fs::Ufs::UFSSwapDir::dereference(StoreEntry & e, bool)
 527 {
 528     debugs(47, 3, HERE << "dereferencing " << &e << " " <<
 529            e.swap_dirn << "/" << e.swap_filen);
 530
 531     if (repl->Dereferenced)
 532         repl->Dereferenced(repl, &e, &e.repl);
 533
 534     return true; // keep e in the global store_table
 535 }
 536
 537 StoreIOState::Pointer
 538 Fs::Ufs::UFSSwapDir::createStoreIO(StoreEntry &e, StoreIOState::STFNCB * file_callback, StoreIOState::STIOCB * aCallback, void *callback_data)
 539 {
 540     return IO->create (this, &e, file_callback, aCallback, callback_data);
 541 }
 542
 543 StoreIOState::Pointer
 544 Fs::Ufs::UFSSwapDir::openStoreIO(StoreEntry &e, StoreIOState::STFNCB * file_callback, StoreIOState::STIOCB * aCallback, void *callback_data)
 545 {
 546     return IO->open (this, &e, file_callback, aCallback, callback_data);
 547 }
 548
 549 int
 550 Fs::Ufs::UFSSwapDir::mapBitTest(sfileno filn)
 551 {
 552     return map->testBit(filn);
 553 }
 554
 555 void
 556 Fs::Ufs::UFSSwapDir::mapBitSet(sfileno filn)
 557 {
 558     map->setBit(filn);
 559 }
 560
 561 void
 562 Fs::Ufs::UFSSwapDir::mapBitReset(sfileno filn)
 563 {
 564     /*
 565      * We have to test the bit before calling clearBit as
 566      * it doesn't do bounds checking and blindly assumes
 567      * filn is a valid file number, but it might not be because
 568      * the map is dynamic in size.  Also clearing an already clear
 569      * bit puts the map counter of-of-whack.
 570      */
 571
 572     if (map->testBit(filn))
 573         map->clearBit(filn);
 574 }
 575
 576 int
 577 Fs::Ufs::UFSSwapDir::mapBitAllocate()
 578 {
 579     int fn;
 580     fn = map->allocate(suggest);
 581     map->setBit(fn);
 582     suggest = fn + 1;
 583     return fn;
 584 }
 585
 586 char *
 587 Fs::Ufs::UFSSwapDir::swapSubDir(int subdirn)const
 588 {
 589     LOCAL_ARRAY(char, fullfilename, MAXPATHLEN);
 590     assert(0 <= subdirn && subdirn < l1);
 591     snprintf(fullfilename, MAXPATHLEN, "%s/%02X", path, subdirn);
 592     return fullfilename;
 593 }
 594
 595 int
 596 Fs::Ufs::UFSSwapDir::createDirectory(const char *aPath, int should_exist)
 597 {
 598     int created = 0;
 599
 600     struct stat st;
 601     getCurrentTime();
 602
 603     if (0 == ::stat(aPath, &st)) {
 604         if (S_ISDIR(st.st_mode)) {
 605             debugs(47, (should_exist ? 3 : DBG_IMPORTANT), aPath << " exists");
 606         } else {
 607             fatalf("Swap directory %s is not a directory.", aPath);
 608         }
 609     } else if (0 == mkdir(aPath, 0755)) {
 610         debugs(47, (should_exist ? DBG_IMPORTANT : 3), aPath << " created");
 611         created = 1;
 612     } else {
 613         fatalf("Failed to make swap directory %s: %s",
 614                aPath, xstrerror());
 615     }
 616
 617     return created;
 618 }
 619
 620 bool
 621 Fs::Ufs::UFSSwapDir::pathIsDirectory(const char *aPath)const
 622 {
 623
 624     struct stat sb;
 625
 626     if (::stat(aPath, &sb) < 0) {
 627         debugs(47, DBG_CRITICAL, "ERROR: " << aPath << ": " << xstrerror());
 628         return false;
 629     }
 630
 631     if (S_ISDIR(sb.st_mode) == 0) {
 632         debugs(47, DBG_CRITICAL, "WARNING: " << aPath << " is not a directory");
 633         return false;
 634     }
 635
 636     return true;
 637 }
 638
 639 bool
 640 Fs::Ufs::UFSSwapDir::verifyCacheDirs()
 641 {
 642     if (!pathIsDirectory(path))
 643         return true;
 644
 645     for (int j = 0; j < l1; ++j) {
 646         char const *aPath = swapSubDir(j);
 647
 648         if (!pathIsDirectory(aPath))
 649             return true;
 650     }
 651
 652     return false;
 653 }
 654
 655 void
 656 Fs::Ufs::UFSSwapDir::createSwapSubDirs()
 657 {
 658     LOCAL_ARRAY(char, name, MAXPATHLEN);
 659
 660     for (int i = 0; i < l1; ++i) {
 661         snprintf(name, MAXPATHLEN, "%s/%02X", path, i);
 662
 663         int should_exist;
 664
 665         if (createDirectory(name, 0))
 666             should_exist = 0;
 667         else
 668             should_exist = 1;
 669
 670         debugs(47, DBG_IMPORTANT, "Making directories in " << name);
 671
 672         for (int k = 0; k < l2; ++k) {
 673             snprintf(name, MAXPATHLEN, "%s/%02X/%02X", path, i, k);
 674             createDirectory(name, should_exist);
 675         }
 676     }
 677 }
 678
 679 char *
 680 Fs::Ufs::UFSSwapDir::logFile(char const *ext) const
 681 {
 682     LOCAL_ARRAY(char, lpath, MAXPATHLEN);
 683     LOCAL_ARRAY(char, pathtmp, MAXPATHLEN);
 684     LOCAL_ARRAY(char, digit, 32);
 685     char *pathtmp2;
 686
 687     if (Config.Log.swap) {
 688         xstrncpy(pathtmp, path, MAXPATHLEN - 64);
 689         pathtmp2 = pathtmp;
 690
 691         while ((pathtmp2 = strchr(pathtmp2, '/')) != NULL)
 692             *pathtmp2 = '.';
 693
 694         while (strlen(pathtmp) && pathtmp[strlen(pathtmp) - 1] == '.')
 695             pathtmp[strlen(pathtmp) - 1] = '\0';
 696
 697         for (pathtmp2 = pathtmp; *pathtmp2 == '.'; ++pathtmp2);
 698         snprintf(lpath, MAXPATHLEN - 64, Config.Log.swap, pathtmp2);
 699
 700         if (strncmp(lpath, Config.Log.swap, MAXPATHLEN - 64) == 0) {
 701             strcat(lpath, ".");
 702             snprintf(digit, 32, "%02d", index);
 703             strncat(lpath, digit, 3);
 704         }
 705     } else {
 706         xstrncpy(lpath, path, MAXPATHLEN - 64);
 707         strcat(lpath, "/swap.state");
 708     }
 709
 710     if (ext)
 711         strncat(lpath, ext, 16);
 712
 713     return lpath;
 714 }
 715
 716 void
 717 Fs::Ufs::UFSSwapDir::openLog()
 718 {
 719     char *logPath;
 720     logPath = logFile();
 721     swaplog_fd = file_open(logPath, O_WRONLY | O_CREAT | O_BINARY);
 722
 723     if (swaplog_fd < 0) {
 724         debugs(50, DBG_IMPORTANT, "ERROR opening swap log " << logPath << ": " << xstrerror());
 725         fatal("UFSSwapDir::openLog: Failed to open swap log.");
 726     }
 727
 728     debugs(50, 3, HERE << "Cache Dir #" << index << " log opened on FD " << swaplog_fd);
 729
 730     if (0 == NumberOfUFSDirs)
 731         assert(NULL == UFSDirToGlobalDirMapping);
 732
 733     ++NumberOfUFSDirs;
 734
 735     assert(NumberOfUFSDirs <= Config.cacheSwap.n_configured);
 736 }
 737
 738 void
 739 Fs::Ufs::UFSSwapDir::closeLog()
 740 {
 741     if (swaplog_fd < 0) /* not open */
 742         return;
 743
 744     file_close(swaplog_fd);
 745
 746     debugs(47, 3, "Cache Dir #" << index << " log closed on FD " << swaplog_fd);
 747
 748     swaplog_fd = -1;
 749
 750     --NumberOfUFSDirs;
 751
 752     assert(NumberOfUFSDirs >= 0);
 753
 754     if (0 == NumberOfUFSDirs)
 755         safe_free(UFSDirToGlobalDirMapping);
 756 }
 757
 758 bool
 759 Fs::Ufs::UFSSwapDir::validL1(int anInt) const
 760 {
 761     return anInt < l1;
 762 }
 763
 764 bool
 765 Fs::Ufs::UFSSwapDir::validL2(int anInt) const
 766 {
 767     return anInt < l2;
 768 }
 769
 770 StoreEntry *
 771 Fs::Ufs::UFSSwapDir::addDiskRestore(const cache_key * key,
 772                                     sfileno file_number,
 773                                     uint64_t swap_file_sz,
 774                                     time_t expires,
 775                                     time_t timestamp,
 776                                     time_t lastref,
 777                                     time_t lastmod,
 778                                     uint32_t refcount,
 779                                     uint16_t newFlags,
 780                                     int)
 781 {
 782     StoreEntry *e = NULL;
 783     debugs(47, 5, HERE << storeKeyText(key)  <<
 784            ", fileno="<< std::setfill('0') << std::hex << std::uppercase << std::setw(8) << file_number);
 785     /* if you call this you'd better be sure file_number is not
 786      * already in use! */
 787     e = new StoreEntry();
 788     e->store_status = STORE_OK;
 789     e->setMemStatus(NOT_IN_MEMORY);
 790     e->swap_status = SWAPOUT_DONE;
 791     e->swap_filen = file_number;
 792     e->swap_dirn = index;
 793     e->swap_file_sz = swap_file_sz;
 794     e->lastref = lastref;
 795     e->timestamp = timestamp;
 796     e->expires = expires;
 797     e->lastmod = lastmod;
 798     e->refcount = refcount;
 799     e->flags = newFlags;
 800     EBIT_CLR(e->flags, RELEASE_REQUEST);
 801     EBIT_CLR(e->flags, KEY_PRIVATE);
 802     e->ping_status = PING_NONE;
 803     EBIT_CLR(e->flags, ENTRY_VALIDATED);
 804     mapBitSet(e->swap_filen);
 805     cur_size += fs.blksize * sizeInBlocks(e->swap_file_sz);
 806     ++n_disk_objects;
 807     e->hashInsert(key); /* do it after we clear KEY_PRIVATE */
 808     replacementAdd (e);
 809     return e;
 810 }
 811
 812 void
 813 Fs::Ufs::UFSSwapDir::undoAddDiskRestore(StoreEntry *e)
 814 {
 815     debugs(47, 5, HERE << *e);
 816     replacementRemove(e); // checks swap_dirn so do it before we invalidate it
 817     // Do not unlink the file as it might be used by a subsequent entry.
 818     mapBitReset(e->swap_filen);
 819     e->swap_filen = -1;
 820     e->swap_dirn = -1;
 821     cur_size -= fs.blksize * sizeInBlocks(e->swap_file_sz);
 822     --n_disk_objects;
 823 }
 824
 825 void
 826 Fs::Ufs::UFSSwapDir::rebuild()
 827 {
 828     ++StoreController::store_dirs_rebuilding;
 829     eventAdd("storeRebuild", Fs::Ufs::RebuildState::RebuildStep, new Fs::Ufs::RebuildState(this), 0.0, 1);
 830 }
 831
 832 void
 833 Fs::Ufs::UFSSwapDir::closeTmpSwapLog()
 834 {
 835     char *swaplog_path = xstrdup(logFile(NULL)); // where the swaplog should be
 836     char *tmp_path = xstrdup(logFile(".new")); // the temporary file we have generated
 837     int fd;
 838     file_close(swaplog_fd);
 839
 840     if (xrename(tmp_path, swaplog_path) < 0) {
 841         fatalf("Failed to rename log file %s to %s", tmp_path, swaplog_path);
 842     }
 843
 844     fd = file_open(swaplog_path, O_WRONLY | O_CREAT | O_BINARY);
 845
 846     if (fd < 0) {
 847         debugs(50, DBG_IMPORTANT, "ERROR: " << swaplog_path << ": " << xstrerror());
 848         fatalf("Failed to open swap log %s", swaplog_path);
 849     }
 850
 851     xfree(swaplog_path);
 852     xfree(tmp_path);
 853     swaplog_fd = fd;
 854     debugs(47, 3, "Cache Dir #" << index << " log opened on FD " << fd);
 855 }
 856
 857 FILE *
 858 Fs::Ufs::UFSSwapDir::openTmpSwapLog(int *clean_flag, int *zero_flag)
 859 {
 860     char *swaplog_path = xstrdup(logFile(NULL));
 861     char *clean_path = xstrdup(logFile(".last-clean"));
 862     char *new_path = xstrdup(logFile(".new"));
 863
 864     struct stat log_sb;
 865
 866     struct stat clean_sb;
 867     FILE *fp;
 868     int fd;
 869
 870     if (::stat(swaplog_path, &log_sb) < 0) {
 871         debugs(47, DBG_IMPORTANT, "Cache Dir #" << index << ": No log file");
 872         safe_free(swaplog_path);
 873         safe_free(clean_path);
 874         safe_free(new_path);
 875         return NULL;
 876     }
 877
 878     *zero_flag = log_sb.st_size == 0 ? 1 : 0;
 879     /* close the existing write-only FD */
 880
 881     if (swaplog_fd >= 0)
 882         file_close(swaplog_fd);
 883
 884     /* open a write-only FD for the new log */
 885     fd = file_open(new_path, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY);
 886
 887     if (fd < 0) {
 888         debugs(50, DBG_IMPORTANT, "ERROR: while opening swap log" << new_path << ": " << xstrerror());
 889         fatalf("Failed to open swap log %s", new_path);
 890     }
 891
 892     swaplog_fd = fd;
 893
 894     {
 895         const StoreSwapLogHeader header;
 896         MemBuf buf;
 897         buf.init(header.record_size, header.record_size);
 898         buf.append(reinterpret_cast<const char*>(&header), sizeof(header));
 899         // Pad to keep in sync with UFSSwapDir::writeCleanStart().
 900         memset(buf.space(), 0, header.gapSize());
 901         buf.appended(header.gapSize());
 902         file_write(swaplog_fd, -1, buf.content(), buf.contentSize(),
 903                    NULL, NULL, buf.freeFunc());
 904     }
 905
 906     /* open a read-only stream of the old log */
 907     fp = fopen(swaplog_path, "rb");
 908
 909     if (fp == NULL) {
 910         debugs(50, DBG_CRITICAL, "ERROR: while opening " << swaplog_path << ": " << xstrerror());
 911         fatalf("Failed to open swap log for reading %s", swaplog_path);
 912     }
 913
 914     memset(&clean_sb, '\0', sizeof(struct stat));
 915
 916     if (::stat(clean_path, &clean_sb) < 0)
 917         *clean_flag = 0;
 918     else if (clean_sb.st_mtime < log_sb.st_mtime)
 919         *clean_flag = 0;
 920     else
 921         *clean_flag = 1;
 922
 923     safeunlink(clean_path, 1);
 924
 925     safe_free(swaplog_path);
 926
 927     safe_free(clean_path);
 928
 929     safe_free(new_path);
 930
 931     return fp;
 932 }
 933
 934 /*
 935  * Begin the process to write clean cache state.  For AUFS this means
 936  * opening some log files and allocating write buffers.  Return 0 if
 937  * we succeed, and assign the 'func' and 'data' return pointers.
 938  */
 939 int
 940 Fs::Ufs::UFSSwapDir::writeCleanStart()
 941 {
 942     UFSCleanLog *state = new UFSCleanLog(this);
 943     StoreSwapLogHeader header;
 944 #if HAVE_FCHMOD
 945
 946     struct stat sb;
 947 #endif
 948
 949     cleanLog = NULL;
 950     state->newLog = xstrdup(logFile(".clean"));
 951     state->fd = file_open(state->newLog, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY);
 952
 953     if (state->fd < 0) {
 954         xfree(state->newLog);
 955         delete state;
 956         return -1;
 957     }
 958
 959     state->cur = xstrdup(logFile(NULL));
 960     state->cln = xstrdup(logFile(".last-clean"));
 961     state->outbuf = (char *)xcalloc(CLEAN_BUF_SZ, 1);
 962     state->outbuf_offset = 0;
 963     /*copy the header */
 964     memcpy(state->outbuf, &header, sizeof(StoreSwapLogHeader));
 965     // Leave a gap to keep in sync with UFSSwapDir::openTmpSwapLog().
 966     memset(state->outbuf + sizeof(StoreSwapLogHeader), 0, header.gapSize());
 967     state->outbuf_offset += header.record_size;
 968
 969     state->walker = repl->WalkInit(repl);
 970     ::unlink(state->cln);
 971     debugs(47, 3, HERE << "opened " << state->newLog << ", FD " << state->fd);
 972 #if HAVE_FCHMOD
 973
 974     if (::stat(state->cur, &sb) == 0)
 975         fchmod(state->fd, sb.st_mode);
 976
 977 #endif
 978
 979     cleanLog = state;
 980     return 0;
 981 }
 982
 983 void
 984 Fs::Ufs::UFSSwapDir::writeCleanDone()
 985 {
 986     UFSCleanLog *state = (UFSCleanLog *)cleanLog;
 987     int fd;
 988
 989     if (NULL == state)
 990         return;
 991
 992     if (state->fd < 0)
 993         return;
 994
 995     state->walker->Done(state->walker);
 996
 997     if (FD_WRITE_METHOD(state->fd, state->outbuf, state->outbuf_offset) < 0) {
 998         debugs(50, DBG_CRITICAL, HERE << state->newLog << ": write: " << xstrerror());
 999         debugs(50, DBG_CRITICAL, HERE << "Current swap logfile not replaced.");
1000         file_close(state->fd);
1001         state->fd = -1;
1002         ::unlink(state->newLog);
1003     }
1004
1005     safe_free(state->outbuf);
1006     /*
1007      * You can't rename open files on Microsoft "operating systems"
1008      * so we have to close before renaming.
1009      */
1010     closeLog();
1011     /* save the fd value for a later test */
1012     fd = state->fd;
1013     /* rename */
1014
1015     if (state->fd >= 0) {
1016 #if _SQUID_OS2_ || _SQUID_WINDOWS_
1017         file_close(state->fd);
1018         state->fd = -1;
1019 #endif
1020
1021         xrename(state->newLog, state->cur);
1022     }
1023
1024     /* touch a timestamp file if we're not still validating */
1025     if (StoreController::store_dirs_rebuilding)
1026         (void) 0;
1027     else if (fd < 0)
1028         (void) 0;
1029     else
1030         file_close(file_open(state->cln, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY));
1031
1032     /* close */
1033     safe_free(state->cur);
1034
1035     safe_free(state->newLog);
1036
1037     safe_free(state->cln);
1038
1039     if (state->fd >= 0)
1040         file_close(state->fd);
1041
1042     state->fd = -1;
1043
1044     delete state;
1045
1046     cleanLog = NULL;
1047 }
1048
1049 void
1050 Fs::Ufs::UFSSwapDir::CleanEvent(void *)
1051 {
1052     static int swap_index = 0;
1053     int i;
1054     int j = 0;
1055     int n = 0;
1056     /*
1057      * Assert that there are UFS cache_dirs configured, otherwise
1058      * we should never be called.
1059      */
1060     assert(NumberOfUFSDirs);
1061
1062     if (NULL == UFSDirToGlobalDirMapping) {
1063         SwapDir *sd;
1064         /*
1065          * Initialize the little array that translates UFS cache_dir
1066          * number into the Config.cacheSwap.swapDirs array index.
1067          */
1068         UFSDirToGlobalDirMapping = (int *)xcalloc(NumberOfUFSDirs, sizeof(*UFSDirToGlobalDirMapping));
1069
1070         for (i = 0, n = 0; i < Config.cacheSwap.n_configured; ++i) {
1071             /* This is bogus, the controller should just clean each instance once */
1072             sd = dynamic_cast <SwapDir *>(INDEXSD(i));
1073
1074             if (!UFSSwapDir::IsUFSDir(sd))
1075                 continue;
1076
1077             UFSSwapDir *usd = dynamic_cast<UFSSwapDir *>(sd);
1078
1079             assert (usd);
1080
1081             UFSDirToGlobalDirMapping[n] = i;
1082             ++n;
1083
1084             j += (usd->l1 * usd->l2);
1085         }
1086
1087         assert(n == NumberOfUFSDirs);
1088         /*
1089          * Start the commonUfsDirClean() swap_index with a random
1090          * value.  j equals the total number of UFS level 2
1091          * swap directories
1092          */
1093         std::mt19937 mt(static_cast<uint32_t>(getCurrentTime() & 0xFFFFFFFF));
1094         xuniform_int_distribution<> dist(0, j);
1095         swap_index = dist(mt);
1096     }
1097
1098     /* if the rebuild is finished, start cleaning directories. */
1099     if (0 == StoreController::store_dirs_rebuilding) {
1100         n = DirClean(swap_index);
1101         ++swap_index;
1102     }
1103
1104     eventAdd("storeDirClean", CleanEvent, NULL,
1105              15.0 * exp(-0.25 * n), 1);
1106 }
1107
1108 bool
1109 Fs::Ufs::UFSSwapDir::IsUFSDir(SwapDir * sd)
1110 {
1111     UFSSwapDir *mySD = dynamic_cast<UFSSwapDir *>(sd);
1112     return (mySD != 0) ;
1113 }
1114
1115 /*
1116  * XXX: this is broken - it assumes all cache dirs use the same
1117  * l1 and l2 scheme. -RBC 20021215. Partial fix is in place -
1118  * if not UFSSwapDir return 0;
1119  */
1120 bool
1121 Fs::Ufs::UFSSwapDir::FilenoBelongsHere(int fn, int F0, int F1, int F2)
1122 {
1123     int D1, D2;
1124     int L1, L2;
1125     int filn = fn;
1126     assert(F0 < Config.cacheSwap.n_configured);
1127     assert (UFSSwapDir::IsUFSDir (dynamic_cast<SwapDir *>(INDEXSD(F0))));
1128     UFSSwapDir *sd = dynamic_cast<UFSSwapDir *>(INDEXSD(F0));
1129
1130     if (!sd)
1131         return 0;
1132
1133     L1 = sd->l1;
1134
1135     L2 = sd->l2;
1136
1137     D1 = ((filn / L2) / L2) % L1;
1138
1139     if (F1 != D1)
1140         return 0;
1141
1142     D2 = (filn / L2) % L2;
1143
1144     if (F2 != D2)
1145         return 0;
1146
1147     return 1;
1148 }
1149
1150 int
1151 Fs::Ufs::UFSSwapDir::validFileno(sfileno filn, int flag) const
1152 {
1153     if (filn < 0)
1154         return 0;
1155
1156     /*
1157      * If flag is set it means out-of-range file number should
1158      * be considered invalid.
1159      */
1160     if (flag)
1161         if (filn > map->capacity())
1162             return 0;
1163
1164     return 1;
1165 }
1166
1167 void
1168 Fs::Ufs::UFSSwapDir::unlinkFile(sfileno f)
1169 {
1170     debugs(79, 3, HERE << "unlinking fileno " <<  std::setfill('0') <<
1171            std::hex << std::uppercase << std::setw(8) << f << " '" <<
1172            fullPath(f,NULL) << "'");
1173     /* commonUfsDirMapBitReset(this, f); */
1174     IO->unlinkFile(fullPath(f,NULL));
1175 }
1176
1177 bool
1178 Fs::Ufs::UFSSwapDir::unlinkdUseful() const
1179 {
1180     // unlinkd may be useful only in workers
1181     return IamWorkerProcess() && IO->io->unlinkdUseful();
1182 }
1183
1184 void
1185 Fs::Ufs::UFSSwapDir::unlink(StoreEntry & e)
1186 {
1187     debugs(79, 3, HERE << "dirno " << index  << ", fileno "<<
1188            std::setfill('0') << std::hex << std::uppercase << std::setw(8) << e.swap_filen);
1189     if (e.swap_status == SWAPOUT_DONE) {
1190         cur_size -= fs.blksize * sizeInBlocks(e.swap_file_sz);
1191         --n_disk_objects;
1192     }
1193     replacementRemove(&e);
1194     mapBitReset(e.swap_filen);
1195     UFSSwapDir::unlinkFile(e.swap_filen);
1196 }
1197
1198 void
1199 Fs::Ufs::UFSSwapDir::replacementAdd(StoreEntry * e)
1200 {
1201     debugs(47, 4, HERE << "added node " << e << " to dir " << index);
1202     repl->Add(repl, e, &e->repl);
1203 }
1204
1205 void
1206 Fs::Ufs::UFSSwapDir::replacementRemove(StoreEntry * e)
1207 {
1208     StorePointer SD;
1209
1210     if (e->swap_dirn < 0)
1211         return;
1212
1213     SD = INDEXSD(e->swap_dirn);
1214
1215     assert (dynamic_cast<UFSSwapDir *>(SD.getRaw()) == this);
1216
1217     debugs(47, 4, HERE << "remove node " << e << " from dir " << index);
1218
1219     repl->Remove(repl, e, &e->repl);
1220 }
1221
1222 void
1223 Fs::Ufs::UFSSwapDir::dump(StoreEntry & entry) const
1224 {
1225     storeAppendPrintf(&entry, " %" PRIu64 " %d %d", maxSize() >> 20, l1, l2);
1226     dumpOptions(&entry);
1227 }
1228
1229 char *
1230 Fs::Ufs::UFSSwapDir::fullPath(sfileno filn, char *fullpath) const
1231 {
1232     LOCAL_ARRAY(char, fullfilename, MAXPATHLEN);
1233     int L1 = l1;
1234     int L2 = l2;
1235
1236     if (!fullpath)
1237         fullpath = fullfilename;
1238
1239     fullpath[0] = '\0';
1240
1241     snprintf(fullpath, MAXPATHLEN, "%s/%02X/%02X/%08X",
1242              path,
1243              ((filn / L2) / L2) % L1,
1244              (filn / L2) % L2,
1245              filn);
1246
1247     return fullpath;
1248 }
1249
1250 int
1251 Fs::Ufs::UFSSwapDir::callback()
1252 {
1253     return IO->callback();
1254 }
1255
1256 void
1257 Fs::Ufs::UFSSwapDir::sync()
1258 {
1259     IO->sync();
1260 }
1261
1262 void
1263 Fs::Ufs::UFSSwapDir::swappedOut(const StoreEntry &e)
1264 {
1265     cur_size += fs.blksize * sizeInBlocks(e.swap_file_sz);
1266     ++n_disk_objects;
1267 }
1268
1269 StoreSearch *
1270 Fs::Ufs::UFSSwapDir::search(String const url, HttpRequest *)
1271 {
1272     if (url.size())
1273         fatal ("Cannot search by url yet\n");
1274
1275     return new Fs::Ufs::StoreSearchUFS (this);
1276 }
1277
1278 void
1279 Fs::Ufs::UFSSwapDir::logEntry(const StoreEntry & e, int op) const
1280 {
1281     StoreSwapLogData *s = new StoreSwapLogData;
1282     s->op = (char) op;
1283     s->swap_filen = e.swap_filen;
1284     s->timestamp = e.timestamp;
1285     s->lastref = e.lastref;
1286     s->expires = e.expires;
1287     s->lastmod = e.lastmod;
1288     s->swap_file_sz = e.swap_file_sz;
1289     s->refcount = e.refcount;
1290     s->flags = e.flags;
1291     memcpy(s->key, e.key, SQUID_MD5_DIGEST_LENGTH);
1292     s->finalize();
1293     file_write(swaplog_fd,
1294                -1,
1295                s,
1296                sizeof(StoreSwapLogData),
1297                NULL,
1298                NULL,
1299                FreeObject);
1300 }
1301
1302 int
1303 Fs::Ufs::UFSSwapDir::DirClean(int swap_index)
1304 {
1305     DIR *dir_pointer = NULL;
1306
1307     LOCAL_ARRAY(char, p1, MAXPATHLEN + 1);
1308     LOCAL_ARRAY(char, p2, MAXPATHLEN + 1);
1309
1310     int files[20];
1311     int swapfileno;
1312     int fn;         /* same as swapfileno, but with dirn bits set */
1313     int n = 0;
1314     int k = 0;
1315     int N0, N1, N2;
1316     int D0, D1, D2;
1317     UFSSwapDir *SD;
1318     N0 = NumberOfUFSDirs;
1319     D0 = UFSDirToGlobalDirMapping[swap_index % N0];
1320     SD = dynamic_cast<UFSSwapDir *>(INDEXSD(D0));
1321     assert (SD);
1322     N1 = SD->l1;
1323     D1 = (swap_index / N0) % N1;
1324     N2 = SD->l2;
1325     D2 = ((swap_index / N0) / N1) % N2;
1326     snprintf(p1, MAXPATHLEN, "%s/%02X/%02X",
1327              SD->path, D1, D2);
1328     debugs(36, 3, HERE << "Cleaning directory " << p1);
1329     dir_pointer = opendir(p1);
1330
1331     if (dir_pointer == NULL) {
1332         if (errno == ENOENT) {
1333             debugs(36, DBG_CRITICAL, HERE << "WARNING: Creating " << p1);
1334             if (mkdir(p1, 0777) == 0)
1335                 return 0;
1336         }
1337
1338         debugs(50, DBG_CRITICAL, HERE << p1 << ": " << xstrerror());
1339         safeunlink(p1, 1);
1340         return 0;
1341     }
1342
1343     dirent_t *de;
1344     while ((de = readdir(dir_pointer)) != NULL && k < 20) {
1345         if (sscanf(de->d_name, "%X", &swapfileno) != 1)
1346             continue;
1347
1348         fn = swapfileno;    /* XXX should remove this cruft ! */
1349
1350         if (SD->validFileno(fn, 1))
1351             if (SD->mapBitTest(fn))
1352                 if (UFSSwapDir::FilenoBelongsHere(fn, D0, D1, D2))
1353                     continue;
1354
1355         files[k] = swapfileno;
1356         ++k;
1357     }
1358
1359     closedir(dir_pointer);
1360
1361     if (k == 0)
1362         return 0;
1363
1364     qsort(files, k, sizeof(int), rev_int_sort);
1365
1366     if (k > 10)
1367         k = 10;
1368
1369     for (n = 0; n < k; ++n) {
1370         debugs(36, 3, HERE << "Cleaning file "<< std::setfill('0') << std::hex << std::uppercase << std::setw(8) << files[n]);
1371         snprintf(p2, MAXPATHLEN + 1, "%s/%08X", p1, files[n]);
1372         safeunlink(p2, 0);
1373         ++statCounter.swap.files_cleaned;
1374     }
1375
1376     debugs(36, 3, HERE << "Cleaned " << k << " unused files from " << p1);
1377     return k;
1378 }
1379