firmware/common/dircache.c

   1 /***************************************************************************
   2  *             __________               __   ___.
   3  *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
   4  *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
   5  *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
   6  *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
   7  *                     \/            \/     \/    \/            \/
   8  * $Id$
   9  *
  10  * Copyright (C) 2005 by Miika Pekkarinen
  11  *
  12  * This program is free software; you can redistribute it and/or
  13  * modify it under the terms of the GNU General Public License
  14  * as published by the Free Software Foundation; either version 2
  15  * of the License, or (at your option) any later version.
  16  *
  17  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
  18  * KIND, either express or implied.
  19  *
  20  ****************************************************************************/
  21
  22 /* TODO:
  23    - Allow cache live updating while transparent rebuild is running.
  24 */
  25
  26 #include "config.h"
  27
  28 #include <stdio.h>
  29 #include <errno.h>
  30 #include "string-extra.h"
  31 #include <stdbool.h>
  32 #include <stdlib.h>
  33 #include "debug.h"
  34 #include "system.h"
  35 #include "logf.h"
  36 #include "dircache.h"
  37 #include "thread.h"
  38 #include "kernel.h"
  39 #include "usb.h"
  40 #include "file.h"
  41 #include "buffer.h"
  42 #include "dir.h"
  43 #include "storage.h"
  44 #if CONFIG_RTC
  45 #include "time.h"
  46 #include "timefuncs.h"
  47 #endif
  48
  49 /* Queue commands. */
  50 #define DIRCACHE_BUILD 1
  51 #define DIRCACHE_STOP  2
  52
  53 #if ((defined(MEMORYSIZE) && (MEMORYSIZE > 8)) || MEM > 8)
  54 #define MAX_OPEN_DIRS 12
  55 #else
  56 #define MAX_OPEN_DIRS 8
  57 #endif
  58 static DIR_CACHED opendirs[MAX_OPEN_DIRS];
  59
  60 static struct dircache_entry *fd_bindings[MAX_OPEN_FILES];
  61 static struct dircache_entry *dircache_root;
  62 #ifdef HAVE_MULTIVOLUME
  63 static struct dircache_entry *append_position;
  64 #endif
  65
  66 static bool dircache_initialized = false;
  67 static bool dircache_initializing = false;
  68 static bool thread_enabled = false;
  69 static unsigned long allocated_size = DIRCACHE_LIMIT;
  70 static unsigned long dircache_size = 0;
  71 static unsigned long entry_count = 0;
  72 static unsigned long reserve_used = 0;
  73 static unsigned int  cache_build_ticks = 0;
  74 static unsigned long appflags = 0;
  75
  76 static struct event_queue dircache_queue;
  77 static long dircache_stack[(DEFAULT_STACK_SIZE + 0x400)/sizeof(long)];
  78 static const char dircache_thread_name[] = "dircache";
  79
  80 static struct fdbind_queue fdbind_cache[MAX_PENDING_BINDINGS];
  81 static int fdbind_idx = 0;
  82
  83 /* --- Internal cache structure control functions --- */
  84
  85 /**
  86  * Internal function to allocate a new dircache_entry from memory.
  87  */
  88 static struct dircache_entry* allocate_entry(void)
  89 {
  90     struct dircache_entry *next_entry;
  91
  92     if (dircache_size > allocated_size - MAX_PATH*2)
  93     {
  94         logf("size limit reached");
  95         return NULL;
  96     }
  97
  98     next_entry = (struct dircache_entry *)((char *)dircache_root+dircache_size);
  99 #ifdef ROCKBOX_STRICT_ALIGN
 100     /* Make sure the entry is long aligned. */
 101     if ((long)next_entry & 0x03)
 102     {
 103         dircache_size += 4 - ((long)next_entry & 0x03);
 104         next_entry = (struct dircache_entry *)(((long)next_entry & ~0x03) + 0x04);
 105     }
 106 #endif
 107     next_entry->name_len = 0;
 108     next_entry->d_name = NULL;
 109     next_entry->up = NULL;
 110     next_entry->down = NULL;
 111     next_entry->next = NULL;
 112
 113     dircache_size += sizeof(struct dircache_entry);
 114
 115     return next_entry;
 116 }
 117
 118 /**
 119  * Internal function to allocate a dircache_entry and set
 120  * ->next entry pointers.
 121  */
 122 static struct dircache_entry* dircache_gen_next(struct dircache_entry *ce)
 123 {
 124     struct dircache_entry *next_entry;
 125
 126     if ( (next_entry = allocate_entry()) == NULL)
 127         return NULL;
 128     next_entry->up = ce->up;
 129     ce->next = next_entry;
 130
 131     return next_entry;
 132 }
 133
 134 /*
 135  * Internal function to allocate a dircache_entry and set
 136  * ->down entry pointers.
 137  */
 138 static struct dircache_entry* dircache_gen_down(struct dircache_entry *ce)
 139 {
 140     struct dircache_entry *next_entry;
 141
 142     if ( (next_entry = allocate_entry()) == NULL)
 143         return NULL;
 144     next_entry->up = ce;
 145     ce->down = next_entry;
 146
 147     return next_entry;
 148 }
 149
 150 /**
 151  * Returns true if there is an event waiting in the queue
 152  * that requires the current operation to be aborted.
 153  */
 154 static bool check_event_queue(void)
 155 {
 156     struct queue_event ev;
 157
 158     if(!queue_peek(&dircache_queue, &ev))
 159         return false;
 160
 161     switch (ev.id)
 162     {
 163         case DIRCACHE_STOP:
 164         case SYS_USB_CONNECTED:
 165 #ifdef HAVE_HOTSWAP
 166         case SYS_FS_CHANGED:
 167 #endif
 168             return true;
 169     }
 170
 171     return false;
 172 }
 173
 174 #if (CONFIG_PLATFORM & PLATFORM_NATIVE)
 175 /* scan and build static data (avoid redundancy on stack) */
 176 static struct
 177 {
 178 #ifdef HAVE_MULTIVOLUME
 179     int volume;
 180 #endif
 181     struct fat_dir *dir;
 182     struct fat_direntry *direntry;
 183 }sab;
 184
 185 static int sab_process_dir(unsigned long startcluster, struct dircache_entry *ce)
 186 {
 187     /* normally, opendir expects a full fat_dir as parent but in our case,
 188      * it's completely useless because we don't modify anything
 189      * WARNING: this heavily relies on current FAT implementation ! */
 190
 191     /* those field are necessary to update the FAT entry in case of modification
 192        here we don't touch anything so we put dummy values */
 193     sab.dir->entry = 0;
 194     sab.dir->entrycount = 0;
 195     sab.dir->file.firstcluster = 0;
 196     /* open directory */
 197     int rc = fat_opendir(IF_MV2(sab.volume,) sab.dir, startcluster, sab.dir);
 198     if(rc < 0)
 199     {
 200         logf("fat_opendir failed: %d", rc);
 201         return rc;
 202     }
 203
 204     /* first pass : read dir */
 205     struct dircache_entry *first_ce = ce;
 206
 207     /* read through directory */
 208     while((rc = fat_getnext(sab.dir, sab.direntry)) >= 0 && sab.direntry->name[0])
 209     {
 210         if(!strcmp(".", sab.direntry->name) ||
 211                 !strcmp("..", sab.direntry->name))
 212             continue;
 213
 214         ce->attribute = sab.direntry->attr;
 215         ce->name_len = strlen(sab.direntry->name) + 1;
 216         ce->d_name = ((char *)dircache_root + dircache_size);
 217         ce->startcluster = sab.direntry->firstcluster;
 218         ce->size = sab.direntry->filesize;
 219         ce->wrtdate = sab.direntry->wrtdate;
 220         ce->wrttime = sab.direntry->wrttime;
 221         memcpy(ce->d_name, sab.direntry->name, ce->name_len);
 222
 223         dircache_size += ce->name_len;
 224         entry_count++;
 225
 226         if(ce->attribute & FAT_ATTR_DIRECTORY)
 227             dircache_gen_down(ce);
 228
 229         ce = dircache_gen_next(ce);
 230         if(ce == NULL)
 231             return -5;
 232
 233         /* When simulator is used, it's only safe to yield here. */
 234         if(thread_enabled)
 235         {
 236             /* Stop if we got an external signal. */
 237             if(check_event_queue())
 238                 return -6;
 239             yield();
 240         }
 241     }
 242
 243     /* add "." and ".." */
 244     ce->d_name = ".";
 245     ce->name_len = 2;
 246     ce->attribute = FAT_ATTR_DIRECTORY;
 247     ce->startcluster = startcluster;
 248     ce->size = 0;
 249     ce->down = first_ce;
 250
 251     ce = dircache_gen_next(ce);
 252
 253     ce->d_name = "..";
 254     ce->name_len = 3;
 255     ce->attribute = FAT_ATTR_DIRECTORY;
 256     ce->startcluster = (first_ce->up ? first_ce->up->startcluster : 0);
 257     ce->size = 0;
 258     ce->down = first_ce->up;
 259
 260     /* second pass: recurse ! */
 261     ce = first_ce;
 262
 263     while(rc >= 0 && ce)
 264     {
 265         if(ce->name_len != 0 && ce->down != NULL && strcmp(ce->d_name, ".") && strcmp(ce->d_name, ".."))
 266             rc = sab_process_dir(ce->startcluster, ce->down);
 267
 268         ce = ce->next;
 269     }
 270
 271     return rc;
 272 }
 273
 274 /* used during the generation */
 275 static struct fat_dir sab_fat_dir;
 276
 277 static int dircache_scan_and_build(IF_MV2(int volume,) struct dircache_entry *ce)
 278 {
 279     memset(ce, 0, sizeof(struct dircache_entry));
 280
 281 #ifdef HAVE_MULTIVOLUME
 282     if (volume > 0)
 283     {
 284         ce->d_name = ((char *)dircache_root+dircache_size);
 285         snprintf(ce->d_name, VOL_ENUM_POS + 3, VOL_NAMES, volume);
 286         ce->name_len = VOL_ENUM_POS + 3;
 287         dircache_size += ce->name_len;
 288         ce->attribute = FAT_ATTR_DIRECTORY | FAT_ATTR_VOLUME;
 289         ce->size = 0;
 290         append_position = dircache_gen_next(ce);
 291         ce = dircache_gen_down(ce);
 292     }
 293 #endif
 294
 295     struct fat_direntry direntry; /* ditto */
 296 #ifdef HAVE_MULTIVOLUME
 297     sab.volume = volume;
 298 #endif
 299     sab.dir = &sab_fat_dir;
 300     sab.direntry = &direntry;
 301
 302     return sab_process_dir(0, ce);
 303 }
 304 #elif (CONFIG_PLATFORM & PLATFORM_HOSTED) /* PLATFORM_HOSTED */
 305 static char sab_path[MAX_PATH];
 306
 307 static int sab_process_dir(struct dircache_entry *ce)
 308 {
 309     struct dirent_uncached *entry;
 310     struct dircache_entry *first_ce = ce;
 311     DIR_UNCACHED *dir = opendir_uncached(sab_path);
 312     if(dir == NULL)
 313     {
 314         logf("Failed to opendir_uncached(%s)", sab_path);
 315         return -1;
 316     }
 317
 318     while((entry = readdir_uncached(dir)))
 319     {
 320         if(!strcmp(".", entry->d_name) ||
 321                 !strcmp("..", entry->d_name))
 322             continue;
 323
 324         ce->attribute = entry->attribute;
 325         ce->name_len = strlen(entry->d_name) + 1;
 326         ce->d_name = ((char *)dircache_root + dircache_size);
 327         ce->size = entry->size;
 328         ce->wrtdate = entry->wrtdate;
 329         ce->wrttime = entry->wrttime;
 330         memcpy(ce->d_name, entry->d_name, ce->name_len);
 331
 332         dircache_size += ce->name_len;
 333         entry_count++;
 334
 335         if(entry->attribute & ATTR_DIRECTORY)
 336         {
 337             dircache_gen_down(ce);
 338             if(ce->down == NULL)
 339             {
 340                 closedir_uncached(dir);
 341                 return -1;
 342             }
 343             /* save current paths size */
 344             int pathpos = strlen(sab_path);
 345             /* append entry */
 346             strlcpy(&sab_path[pathpos], "/", sizeof(sab_path) - pathpos);
 347             strlcpy(&sab_path[pathpos+1], entry->d_name, sizeof(sab_path) - pathpos - 1);
 348
 349             int rc = sab_process_dir(ce->down);
 350             /* restore path */
 351             sab_path[pathpos] = '\0';
 352
 353             if(rc < 0)
 354             {
 355                 closedir_uncached(dir);
 356                 return rc;
 357             }
 358         }
 359
 360         ce = dircache_gen_next(ce);
 361         if(ce == NULL)
 362             return -5;
 363
 364         /* When simulator is used, it's only safe to yield here. */
 365         if(thread_enabled)
 366         {
 367             /* Stop if we got an external signal. */
 368             if(check_event_queue())
 369                 return -1;
 370             yield();
 371         }
 372     }
 373
 374     /* add "." and ".." */
 375     ce->d_name = ".";
 376     ce->name_len = 2;
 377     ce->attribute = ATTR_DIRECTORY;
 378     ce->size = 0;
 379     ce->down = first_ce;
 380
 381     ce = dircache_gen_next(ce);
 382
 383     ce->d_name = "..";
 384     ce->name_len = 3;
 385     ce->attribute = ATTR_DIRECTORY;
 386     ce->size = 0;
 387     ce->down = first_ce->up;
 388
 389     closedir_uncached(dir);
 390     return 0;
 391 }
 392
 393 static int dircache_scan_and_build(IF_MV2(int volume,) struct dircache_entry *ce)
 394 {
 395     #ifdef HAVE_MULTIVOLUME
 396     (void) volume;
 397     #endif
 398     memset(ce, 0, sizeof(struct dircache_entry));
 399
 400     strlcpy(sab_path, "/", sizeof sab_path);
 401     return sab_process_dir(ce);
 402 }
 403 #endif /* PLATFORM_NATIVE */
 404
 405 /**
 406  * Internal function to get a pointer to dircache_entry for a given filename.
 407  *   path: Absolute path to a file or directory (see comment)
 408  *   go_down: Returns the first entry of the directory given by the path (see comment)
 409  *
 410  * As a a special case, accept path="" as an alias for "/".
 411  * Also if the path omits the first '/', it will be accepted.
 412  *
 413  * * If get_down=true:
 414  *   If path="/", the returned entry is the first of root directory (ie dircache_root)
 415  *   Otherwise, if 'entry' is the returned value when get_down=false,
 416  *   the functions returns entry->down (which can be NULL)
 417  *
 418  * * If get_down=false:
 419  *   If path="/chunk_1/chunk_2/.../chunk_n" then this functions returns the entry
 420  *   root_entry()->chunk_1->chunk_2->...->chunk_(n-1)
 421  *   Which means that
 422  *   dircache_get_entry(path)->d_name == chunk_n
 423  *
 424  *   If path="/", the returned entry is NULL.
 425  *   If the entry doesn't exist, return NULL
 426  *
 427  *  NOTE: this functions silently handles double '/'
 428  */
 429 static struct dircache_entry* dircache_get_entry(const char *path, bool go_down)
 430 {
 431     char namecopy[MAX_PATH];
 432     char* part;
 433     char* end;
 434
 435     bool at_root = true;
 436     struct dircache_entry *cache_entry = dircache_root;
 437
 438     strlcpy(namecopy, path, sizeof(namecopy));
 439
 440     for(part = strtok_r(namecopy, "/", &end); part; part = strtok_r(NULL, "/", &end))
 441     {
 442         /* If request another chunk, the current entry has to be directory
 443          * and so cache_entry->down has to be non-NULL/
 444          * Special case of root because it's already the first entry of the root directory
 445          *
 446          * NOTE: this is safe even if cache_entry->down is NULL */
 447         if(!at_root)
 448             cache_entry = cache_entry->down;
 449         else
 450             at_root = false;
 451
 452         /* scan dir for name */
 453         while(cache_entry != NULL)
 454         {
 455             /* skip unused entries */
 456             if(cache_entry->name_len == 0)
 457             {
 458                 cache_entry = cache_entry->next;
 459                 continue;
 460             }
 461             /* compare names */
 462             if(!strcasecmp(part, cache_entry->d_name))
 463                 break;
 464             /* go to next entry */
 465             cache_entry = cache_entry->next;
 466         }
 467
 468         /* handle not found case */
 469         if(cache_entry == NULL)
 470             return NULL;
 471     }
 472
 473     /* NOTE: here cache_entry!=NULL so taking ->down is safe */
 474     if(go_down)
 475         return at_root ? cache_entry : cache_entry->down;
 476     else
 477         return at_root ? NULL : cache_entry;
 478 }
 479
 480 #ifdef HAVE_EEPROM_SETTINGS
 481 /**
 482  * Function to load the internal cache structure from disk to initialize
 483  * the dircache really fast and little disk access.
 484  */
 485 int dircache_load(void)
 486 {
 487     struct dircache_maindata maindata;
 488     int bytes_read;
 489     int fd;
 490
 491     if (dircache_initialized)
 492         return -1;
 493
 494     logf("Loading directory cache");
 495     dircache_size = 0;
 496
 497     fd = open(DIRCACHE_FILE, O_RDONLY);
 498     if (fd < 0)
 499         return -2;
 500
 501     bytes_read = read(fd, &maindata, sizeof(struct dircache_maindata));
 502     if (bytes_read != sizeof(struct dircache_maindata)
 503         || maindata.size <= 0)
 504     {
 505         logf("Dircache file header error");
 506         close(fd);
 507         remove(DIRCACHE_FILE);
 508         return -3;
 509     }
 510
 511     dircache_root = buffer_alloc(0);
 512     if ((long)maindata.root_entry != (long)dircache_root)
 513     {
 514         logf("Position missmatch");
 515         close(fd);
 516         remove(DIRCACHE_FILE);
 517         return -4;
 518     }
 519
 520     dircache_root = buffer_alloc(maindata.size + DIRCACHE_RESERVE);
 521     entry_count = maindata.entry_count;
 522     appflags = maindata.appflags;
 523     bytes_read = read(fd, dircache_root, MIN(DIRCACHE_LIMIT, maindata.size));
 524     close(fd);
 525     remove(DIRCACHE_FILE);
 526
 527     if (bytes_read != maindata.size)
 528     {
 529         logf("Dircache read failed");
 530         return -6;
 531     }
 532
 533     /* Cache successfully loaded. */
 534     dircache_size = maindata.size;
 535     allocated_size = dircache_size + DIRCACHE_RESERVE;
 536     reserve_used = 0;
 537     logf("Done, %ld KiB used", dircache_size / 1024);
 538     dircache_initialized = true;
 539     memset(fd_bindings, 0, sizeof(fd_bindings));
 540
 541     return 0;
 542 }
 543
 544 /**
 545  * Function to save the internal cache stucture to disk for fast loading
 546  * on boot.
 547  */
 548 int dircache_save(void)
 549 {
 550     struct dircache_maindata maindata;
 551     int fd;
 552     unsigned long bytes_written;
 553
 554     remove(DIRCACHE_FILE);
 555
 556     if (!dircache_initialized)
 557         return -1;
 558
 559     logf("Saving directory cache");
 560     fd = open(DIRCACHE_FILE, O_WRONLY | O_CREAT | O_TRUNC, 0666);
 561
 562     maindata.magic = DIRCACHE_MAGIC;
 563     maindata.size = dircache_size;
 564     maindata.root_entry = dircache_root;
 565     maindata.entry_count = entry_count;
 566     maindata.appflags = appflags;
 567
 568     /* Save the info structure */
 569     bytes_written = write(fd, &maindata, sizeof(struct dircache_maindata));
 570     if (bytes_written != sizeof(struct dircache_maindata))
 571     {
 572         close(fd);
 573         logf("dircache: write failed #1");
 574         return -2;
 575     }
 576
 577     /* Dump whole directory cache to disk */
 578     bytes_written = write(fd, dircache_root, dircache_size);
 579     close(fd);
 580     if (bytes_written != dircache_size)
 581     {
 582         logf("dircache: write failed #2");
 583         return -3;
 584     }
 585
 586     return 0;
 587 }
 588 #endif /* #if 0 */
 589
 590 /**
 591  * Internal function which scans the disk and creates the dircache structure.
 592  */
 593 static int dircache_do_rebuild(void)
 594 {
 595     unsigned int start_tick;
 596     int i;
 597
 598     /* Measure how long it takes build the cache. */
 599     start_tick = current_tick;
 600     dircache_initializing = true;
 601     appflags = 0;
 602     entry_count = 0;
 603
 604     dircache_size = sizeof(struct dircache_entry);
 605
 606 #ifdef HAVE_MULTIVOLUME
 607     append_position = dircache_root;
 608
 609     for (i = NUM_VOLUMES; i >= 0; i--)
 610     {
 611         if (fat_ismounted(i))
 612         {
 613 #endif
 614             cpu_boost(true);
 615 #ifdef HAVE_MULTIVOLUME
 616             if (dircache_scan_and_build(IF_MV2(i,) append_position) < 0)
 617 #else
 618             if (dircache_scan_and_build(IF_MV2(0,) dircache_root) < 0)
 619 #endif /* HAVE_MULTIVOLUME */
 620             {
 621                 logf("dircache_scan_and_build failed");
 622                 cpu_boost(false);
 623                 dircache_size = 0;
 624                 dircache_initializing = false;
 625                 return -2;
 626             }
 627             cpu_boost(false);
 628 #ifdef HAVE_MULTIVOLUME
 629         }
 630     }
 631 #endif
 632
 633     logf("Done, %ld KiB used", dircache_size / 1024);
 634
 635     dircache_initialized = true;
 636     dircache_initializing = false;
 637     cache_build_ticks = current_tick - start_tick;
 638
 639     /* Initialized fd bindings. */
 640     memset(fd_bindings, 0, sizeof(fd_bindings));
 641     for (i = 0; i < fdbind_idx; i++)
 642         dircache_bind(fdbind_cache[i].fd, fdbind_cache[i].path);
 643     fdbind_idx = 0;
 644
 645     if (thread_enabled)
 646     {
 647         if (allocated_size - dircache_size < DIRCACHE_RESERVE)
 648             reserve_used = DIRCACHE_RESERVE - (allocated_size - dircache_size);
 649     }
 650     else
 651     {
 652         /* We have to long align the audiobuf to keep the buffer access fast. */
 653         audiobuf += (long)((dircache_size & ~0x03) + 0x04);
 654         audiobuf += DIRCACHE_RESERVE;
 655         allocated_size = dircache_size + DIRCACHE_RESERVE;
 656         reserve_used = 0;
 657     }
 658
 659     return 1;
 660 }
 661
 662 /**
 663  * Internal thread that controls transparent cache building.
 664  */
 665 static void dircache_thread(void)
 666 {
 667     struct queue_event ev;
 668
 669     while (1)
 670     {
 671         queue_wait(&dircache_queue, &ev);
 672
 673         switch (ev.id)
 674         {
 675 #ifdef HAVE_HOTSWAP
 676             case SYS_FS_CHANGED:
 677                 if (!dircache_initialized)
 678                     break;
 679                 dircache_initialized = false;
 680 #endif
 681             case DIRCACHE_BUILD:
 682                 thread_enabled = true;
 683                 dircache_do_rebuild();
 684                 thread_enabled = false;
 685                 break ;
 686
 687             case DIRCACHE_STOP:
 688                 logf("Stopped the rebuilding.");
 689                 dircache_initialized = false;
 690                 break ;
 691
 692 #if (CONFIG_PLATFORM & PLATFORM_NATIVE)
 693             case SYS_USB_CONNECTED:
 694                 usb_acknowledge(SYS_USB_CONNECTED_ACK);
 695                 usb_wait_for_disconnect(&dircache_queue);
 696                 break ;
 697 #endif
 698         }
 699     }
 700 }
 701
 702 /**
 703  * Start scanning the disk to build the dircache.
 704  * Either transparent or non-transparent build method is used.
 705  */
 706 int dircache_build(int last_size)
 707 {
 708     if (dircache_initialized || thread_enabled)
 709         return -3;
 710
 711     logf("Building directory cache");
 712     remove(DIRCACHE_FILE);
 713
 714     /* Background build, dircache has been previously allocated */
 715     if (dircache_size > 0)
 716     {
 717         thread_enabled = true;
 718         dircache_initializing = true;
 719         queue_post(&dircache_queue, DIRCACHE_BUILD, 0);
 720         return 2;
 721     }
 722
 723     if (last_size > DIRCACHE_RESERVE && last_size < DIRCACHE_LIMIT )
 724     {
 725         allocated_size = last_size + DIRCACHE_RESERVE;
 726         dircache_root = buffer_alloc(allocated_size);
 727         thread_enabled = true;
 728
 729         /* Start a transparent rebuild. */
 730         queue_post(&dircache_queue, DIRCACHE_BUILD, 0);
 731         return 3;
 732     }
 733
 734     dircache_root = (struct dircache_entry *)(((long)audiobuf & ~0x03) + 0x04);
 735
 736     /* Start a non-transparent rebuild. */
 737     return dircache_do_rebuild();
 738 }
 739
 740 /**
 741  * Steal the allocated dircache buffer and disable dircache.
 742  */
 743 void* dircache_steal_buffer(long *size)
 744 {
 745     dircache_disable();
 746     if (dircache_size == 0)
 747     {
 748         *size = 0;
 749         return NULL;
 750     }
 751
 752     *size = dircache_size + (DIRCACHE_RESERVE-reserve_used);
 753
 754     return dircache_root;
 755 }
 756
 757 /**
 758  * Main initialization function that must be called before any other
 759  * operations within the dircache.
 760  */
 761 void dircache_init(void)
 762 {
 763     int i;
 764     int thread_id;
 765
 766     dircache_initialized = false;
 767     dircache_initializing = false;
 768
 769     memset(opendirs, 0, sizeof(opendirs));
 770     for (i = 0; i < MAX_OPEN_DIRS; i++)
 771     {
 772         opendirs[i].theent.d_name = buffer_alloc(MAX_PATH);
 773     }
 774
 775     queue_init(&dircache_queue, true);
 776     thread_id = create_thread(dircache_thread, dircache_stack,
 777                 sizeof(dircache_stack), 0, dircache_thread_name
 778                 IF_PRIO(, PRIORITY_BACKGROUND)
 779                 IF_COP(, CPU));
 780 #ifdef HAVE_IO_PRIORITY
 781     thread_set_io_priority(thread_id,IO_PRIORITY_BACKGROUND);
 782 #endif
 783
 784 }
 785
 786 /**
 787  * Returns true if dircache has been initialized and is ready to be used.
 788  */
 789 bool dircache_is_enabled(void)
 790 {
 791     return dircache_initialized;
 792 }
 793
 794 /**
 795  * Returns true if dircache is being initialized.
 796  */
 797 bool dircache_is_initializing(void)
 798 {
 799     return dircache_initializing || thread_enabled;
 800 }
 801
 802 /**
 803  * Set application flags used to determine if dircache is still intact.
 804  */
 805 void dircache_set_appflag(long mask)
 806 {
 807     appflags |= mask;
 808 }
 809
 810 /**
 811  * Get application flags used to determine if dircache is still intact.
 812  */
 813 bool dircache_get_appflag(long mask)
 814 {
 815     return dircache_is_enabled() && (appflags & mask);
 816 }
 817
 818 /**
 819  * Returns the current number of entries (directories and files) in the cache.
 820  */
 821 int dircache_get_entry_count(void)
 822 {
 823     return entry_count;
 824 }
 825
 826 /**
 827  * Returns the allocated space for dircache (without reserve space).
 828  */
 829 int dircache_get_cache_size(void)
 830 {
 831     return dircache_is_enabled() ? dircache_size : 0;
 832 }
 833
 834 /**
 835  * Returns how many bytes of the reserve allocation for live cache
 836  * updates have been used.
 837  */
 838 int dircache_get_reserve_used(void)
 839 {
 840     return dircache_is_enabled() ? reserve_used : 0;
 841 }
 842
 843 /**
 844  * Returns the time in kernel ticks that took to build the cache.
 845  */
 846 int dircache_get_build_ticks(void)
 847 {
 848     return dircache_is_enabled() ? cache_build_ticks : 0;
 849 }
 850
 851 /**
 852  * Disables the dircache. Usually called on shutdown or when
 853  * accepting a usb connection.
 854  */
 855 void dircache_disable(void)
 856 {
 857     int i;
 858     bool cache_in_use;
 859
 860     if (thread_enabled)
 861         queue_post(&dircache_queue, DIRCACHE_STOP, 0);
 862
 863     while (thread_enabled)
 864         sleep(1);
 865     dircache_initialized = false;
 866
 867     logf("Waiting for cached dirs to release");
 868     do {
 869         cache_in_use = false;
 870         for (i = 0; i < MAX_OPEN_DIRS; i++) {
 871             if (!opendirs[i].regulardir && opendirs[i].busy)
 872             {
 873                 cache_in_use = true;
 874                 sleep(1);
 875                 break ;
 876             }
 877         }
 878     } while (cache_in_use) ;
 879
 880     logf("Cache released");
 881     entry_count = 0;
 882 }
 883
 884 /**
 885  * Usermode function to return dircache_entry pointer to the given path.
 886  */
 887 const struct dircache_entry *dircache_get_entry_ptr(const char *filename)
 888 {
 889     if (!dircache_initialized || filename == NULL)
 890         return NULL;
 891
 892     return dircache_get_entry(filename, false);
 893 }
 894
 895 /**
 896  * Function to copy the full absolute path from dircache to the given buffer
 897  * using the given dircache_entry pointer.
 898  */
 899 void dircache_copy_path(const struct dircache_entry *entry, char *buf, int size)
 900 {
 901     int path_size = 0;
 902     int idx;
 903     const struct dircache_entry *temp = entry;
 904
 905     if (size <= 0)
 906         return ;
 907
 908     /* first compute the necessary size */
 909     while(temp != NULL)
 910     {
 911         path_size += temp->name_len; /* '/' + d_name */
 912         temp = temp->up;
 913     }
 914
 915     /* now copy the path */
 916     /* doesn't matter with trailing 0 because it's added later */
 917     idx = path_size;
 918     while(entry != NULL)
 919     {
 920         idx -= entry->name_len;
 921         /* available size */
 922         int rem = size - idx;
 923
 924         if(rem >= 1)
 925         {
 926             buf[idx] = '/';
 927             memcpy(buf + idx + 1, entry->d_name, MIN((size_t)(rem - 1), (size_t)(entry->name_len - 1)));
 928         }
 929         entry = entry->up;
 930     }
 931
 932     /* add trailing 0 */
 933     buf[MIN(path_size, size-1)] = 0;
 934 }
 935
 936 /* --- Directory cache live updating functions --- */
 937 static int block_until_ready(void)
 938 {
 939     /* Block until dircache has been built. */
 940     while (!dircache_initialized && dircache_is_initializing())
 941         sleep(1);
 942
 943     if (!dircache_initialized)
 944         return -1;
 945
 946     return 0;
 947 }
 948
 949 static struct dircache_entry* dircache_new_entry(const char *path, int attribute)
 950 {
 951     struct dircache_entry *entry;
 952     char basedir[MAX_PATH*2];
 953     char *new;
 954     long last_cache_size = dircache_size;
 955
 956     strlcpy(basedir, path, sizeof(basedir));
 957     new = strrchr(basedir, '/');
 958     if (new == NULL)
 959     {
 960         logf("error occurred");
 961         dircache_initialized = false;
 962         return NULL;
 963     }
 964
 965     *new = '\0';
 966     new++;
 967
 968     entry = dircache_get_entry(basedir, true);
 969     if (entry == NULL)
 970     {
 971         logf("basedir not found!");
 972         logf("%s", basedir);
 973         dircache_initialized = false;
 974         return NULL;
 975     }
 976
 977     if (reserve_used + 2*sizeof(struct dircache_entry) + strlen(new)+1
 978         >= DIRCACHE_RESERVE)
 979     {
 980         logf("not enough space");
 981         dircache_initialized = false;
 982         return NULL;
 983     }
 984
 985     while (entry->next != NULL)
 986         entry = entry->next;
 987
 988     if (entry->name_len > 0)
 989         entry = dircache_gen_next(entry);
 990
 991     if (entry == NULL)
 992     {
 993         dircache_initialized = false;
 994         return NULL;
 995     }
 996
 997     entry->attribute = attribute;
 998     entry->name_len = MIN(254, strlen(new)) + 1;
 999     entry->d_name = ((char *)dircache_root+dircache_size);
1000     entry->startcluster = 0;
1001     entry->wrtdate = 0;
1002     entry->wrttime = 0;
1003     entry->size = 0;
1004     memcpy(entry->d_name, new, entry->name_len);
1005     dircache_size += entry->name_len;
1006
1007     if (attribute & ATTR_DIRECTORY)
1008     {
1009         logf("gen_down");
1010         dircache_gen_down(entry);
1011     }
1012
1013     reserve_used += dircache_size - last_cache_size;
1014
1015     return entry;
1016 }
1017
1018 void dircache_bind(int fd, const char *path)
1019 {
1020     struct dircache_entry *entry;
1021
1022     /* Queue requests until dircache has been built. */
1023     if (!dircache_initialized && dircache_is_initializing())
1024     {
1025         if (fdbind_idx >= MAX_PENDING_BINDINGS)
1026             return ;
1027         strlcpy(fdbind_cache[fdbind_idx].path, path,
1028                 sizeof(fdbind_cache[fdbind_idx].path));
1029         fdbind_cache[fdbind_idx].fd = fd;
1030         fdbind_idx++;
1031         return ;
1032     }
1033
1034     if (!dircache_initialized)
1035         return ;
1036
1037     logf("bind: %d/%s", fd, path);
1038     entry = dircache_get_entry(path, false);
1039     if (entry == NULL)
1040     {
1041         logf("not found!");
1042         dircache_initialized = false;
1043         return ;
1044     }
1045
1046     fd_bindings[fd] = entry;
1047 }
1048
1049 void dircache_update_filesize(int fd, long newsize, long startcluster)
1050 {
1051     if (!dircache_initialized || fd < 0)
1052         return ;
1053
1054     if (fd_bindings[fd] == NULL)
1055     {
1056         logf("dircache fd(%d) access error", fd);
1057         dircache_initialized = false;
1058         return ;
1059     }
1060
1061     fd_bindings[fd]->size = newsize;
1062     fd_bindings[fd]->startcluster = startcluster;
1063 }
1064 void dircache_update_filetime(int fd)
1065 {
1066 #if CONFIG_RTC == 0
1067     (void)fd;
1068 #else
1069     short year;
1070     struct tm *now = get_time();
1071     if (!dircache_initialized || fd < 0)
1072         return ;
1073
1074     if (fd_bindings[fd] == NULL)
1075     {
1076         logf("dircache fd access error");
1077         dircache_initialized = false;
1078         return ;
1079     }
1080     year = now->tm_year+1900-1980;
1081     fd_bindings[fd]->wrtdate = (((year)&0x7f)<<9)           |
1082                                (((now->tm_mon+1)&0xf)<<5)   |
1083                                (((now->tm_mday)&0x1f));
1084     fd_bindings[fd]->wrttime = (((now->tm_hour)&0x1f)<<11)  |
1085                                (((now->tm_min)&0x3f)<<5)    |
1086                                (((now->tm_sec/2)&0x1f));
1087 #endif
1088 }
1089
1090 void dircache_mkdir(const char *path)
1091 { /* Test ok. */
1092     if (block_until_ready())
1093         return ;
1094
1095
1096     logf("mkdir: %s", path);
1097     dircache_new_entry(path, ATTR_DIRECTORY);
1098 }
1099
1100 void dircache_rmdir(const char *path)
1101 { /* Test ok. */
1102     struct dircache_entry *entry;
1103
1104     if (block_until_ready())
1105         return ;
1106
1107     logf("rmdir: %s", path);
1108     entry = dircache_get_entry(path, false);
1109     if (entry == NULL || entry->down == NULL)
1110     {
1111         logf("not found or not a directory!");
1112         dircache_initialized = false;
1113         return ;
1114     }
1115
1116     entry->down = NULL;
1117     entry->name_len = 0;
1118 }
1119
1120 /* Remove a file from cache */
1121 void dircache_remove(const char *name)
1122 { /* Test ok. */
1123     struct dircache_entry *entry;
1124
1125     if (block_until_ready())
1126         return ;
1127
1128     logf("remove: %s", name);
1129
1130     entry = dircache_get_entry(name, false);
1131
1132     if (entry == NULL)
1133     {
1134         logf("not found!");
1135         dircache_initialized = false;
1136         return ;
1137     }
1138
1139     entry->name_len = 0;
1140 }
1141
1142 void dircache_rename(const char *oldpath, const char *newpath)
1143 { /* Test ok. */
1144     struct dircache_entry *entry, *newentry;
1145     struct dircache_entry oldentry;
1146     char absolute_path[MAX_PATH*2];
1147     char *p;
1148
1149     if (block_until_ready())
1150         return ;
1151
1152     logf("rename: %s->%s", oldpath, newpath);
1153
1154     entry = dircache_get_entry(oldpath, false);
1155     if (entry == NULL)
1156     {
1157         logf("not found!");
1158         dircache_initialized = false;
1159         return ;
1160     }
1161
1162     /* Delete the old entry. */
1163     entry->name_len = 0;
1164
1165     /** If we rename the same filename twice in a row, we need to
1166      * save the data, because the entry will be re-used. */
1167     oldentry = *entry;
1168
1169     /* Generate the absolute path for destination if necessary. */
1170     if (newpath[0] != '/')
1171     {
1172         strlcpy(absolute_path, oldpath, sizeof(absolute_path));
1173         p = strrchr(absolute_path, '/');
1174         if (!p)
1175         {
1176             logf("Invalid path");
1177             dircache_initialized = false;
1178             return ;
1179         }
1180
1181         *p = '\0';
1182         strlcpy(p, absolute_path, sizeof(absolute_path)-strlen(p));
1183         newpath = absolute_path;
1184     }
1185
1186     newentry = dircache_new_entry(newpath, entry->attribute);
1187     if (newentry == NULL)
1188     {
1189         dircache_initialized = false;
1190         return ;
1191     }
1192
1193     newentry->down = oldentry.down;
1194     newentry->size = oldentry.size;
1195     newentry->startcluster = oldentry.startcluster;
1196     newentry->wrttime = oldentry.wrttime;
1197     newentry->wrtdate = oldentry.wrtdate;
1198 }
1199
1200 void dircache_add_file(const char *path, long startcluster)
1201 {
1202     struct dircache_entry *entry;
1203
1204     if (block_until_ready())
1205         return ;
1206
1207     logf("add file: %s", path);
1208     entry = dircache_new_entry(path, 0);
1209     if (entry == NULL)
1210         return ;
1211
1212     entry->startcluster = startcluster;
1213 }
1214
1215 static bool is_disable_msg_pending(void)
1216 {
1217     return check_event_queue();
1218 }
1219
1220 DIR_CACHED* opendir_cached(const char* name)
1221 {
1222     int dd;
1223     DIR_CACHED* pdir = opendirs;
1224
1225     if ( name[0] != '/' )
1226     {
1227         DEBUGF("Only absolute paths supported right now\n");
1228         return NULL;
1229     }
1230
1231     /* find a free dir descriptor */
1232     for ( dd=0; dd<MAX_OPEN_DIRS; dd++, pdir++)
1233         if ( !pdir->busy )
1234             break;
1235
1236     if ( dd == MAX_OPEN_DIRS )
1237     {
1238         DEBUGF("Too many dirs open\n");
1239         errno = EMFILE;
1240         return NULL;
1241     }
1242
1243     pdir->busy = true;
1244
1245     if (!dircache_initialized || is_disable_msg_pending())
1246     {
1247         pdir->internal_entry = NULL;
1248         pdir->regulardir = opendir_uncached(name);
1249     }
1250     else
1251     {
1252         pdir->regulardir = NULL;
1253         pdir->internal_entry = dircache_get_entry(name, true);
1254         pdir->theent.attribute = -1; /* used to make readdir_cached aware of the first call */
1255     }
1256
1257     if (pdir->internal_entry == NULL && pdir->regulardir == NULL)
1258     {
1259         pdir->busy = false;
1260         return NULL;
1261     }
1262
1263     return pdir;
1264 }
1265
1266 struct dirent_cached* readdir_cached(DIR_CACHED* dir)
1267 {
1268     struct dircache_entry *ce = dir->internal_entry;
1269     struct dirent_uncached *regentry;
1270
1271     if (!dir->busy)
1272         return NULL;
1273
1274     if (dir->regulardir != NULL)
1275     {
1276         regentry = readdir_uncached(dir->regulardir);
1277         if (regentry == NULL)
1278             return NULL;
1279
1280         strlcpy(dir->theent.d_name, regentry->d_name, MAX_PATH);
1281         dir->theent.size = regentry->size;
1282         dir->theent.startcluster = regentry->startcluster;
1283         dir->theent.attribute = regentry->attribute;
1284         dir->theent.wrttime = regentry->wrttime;
1285         dir->theent.wrtdate = regentry->wrtdate;
1286
1287         return &dir->theent;
1288     }
1289
1290     /* if theent.attribute=-1 then this is the first call */
1291     /* otherwise, this is is not so we first take the entry's ->next */
1292     /* NOTE: normal file can't have attribute=-1 */
1293     if(dir->theent.attribute != -1)
1294         ce = ce->next;
1295     /* skip unused entries */
1296     while(ce != NULL && ce->name_len == 0)
1297         ce = ce->next;
1298
1299     if (ce == NULL)
1300             return NULL;
1301
1302     strlcpy(dir->theent.d_name, ce->d_name, MAX_PATH);
1303     /* Can't do `dir->theent = *ce`
1304        because that modifies the d_name pointer. */
1305     dir->theent.size = ce->size;
1306     dir->theent.startcluster = ce->startcluster;
1307     dir->theent.attribute = ce->attribute;
1308     dir->theent.wrttime = ce->wrttime;
1309     dir->theent.wrtdate = ce->wrtdate;
1310     dir->internal_entry = ce;
1311
1312     //logf("-> %s", ce->name);
1313     return &dir->theent;
1314 }
1315
1316 int closedir_cached(DIR_CACHED* dir)
1317 {
1318     if (!dir->busy)
1319         return -1;
1320
1321     dir->busy=false;
1322     if (dir->regulardir != NULL)
1323         return closedir_uncached(dir->regulardir);
1324
1325     return 0;
1326 }
1327
1328 int mkdir_cached(const char *name)
1329 {
1330     int rc=mkdir_uncached(name);
1331     if (rc >= 0)
1332         dircache_mkdir(name);
1333     return(rc);
1334 }
1335
1336 int rmdir_cached(const char* name)
1337 {
1338     int rc=rmdir_uncached(name);
1339     if(rc >= 0)
1340         dircache_rmdir(name);
1341     return(rc);
1342 }