lib/libstand/hammer2.c

   1 /*
   2  * Copyright (c) 2011-2013 The DragonFly Project.  All rights reserved.
   3  *
   4  * This code is derived from software contributed to The DragonFly Project
   5  * by Matthew Dillon <dillon@dragonflybsd.org>
   6  * by Venkatesh Srinivas <vsrinivas@dragonflybsd.org>
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  *
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer in
  16  *    the documentation and/or other materials provided with the
  17  *    distribution.
  18  * 3. Neither the name of The DragonFly Project nor the names of its
  19  *    contributors may be used to endorse or promote products derived
  20  *    from this software without specific, prior written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  23  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  24  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  25  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
  26  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  27  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
  28  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  29  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
  30  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  31  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  32  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  33  * SUCH DAMAGE.
  34  */
  35
  36 #if !defined(BOOT2) && !defined(TESTING)
  37 #define LIBSTAND        1
  38 #endif
  39
  40 #ifdef BOOT2
  41 #include "boot2.h"
  42 #endif
  43
  44 #ifdef TESTING
  45 #include <sys/types.h>
  46 #include <sys/stat.h>
  47 #include <sys/uuid.h>
  48 #include <stdio.h>
  49 #include <stdlib.h>
  50 #include <stddef.h>
  51 #include <stdint.h>
  52 #include <unistd.h>
  53 #include <fcntl.h>
  54 #include <string.h>
  55 #include <strings.h>
  56 #include <errno.h>
  57 #endif
  58
  59 #ifdef LIBSTAND
  60 #include "stand.h"
  61 #endif
  62
  63 #include <vfs/hammer2/hammer2_disk.h>
  64
  65 uint32_t iscsi_crc32(const void *buf, size_t size);
  66 uint32_t iscsi_crc32_ext(const void *buf, size_t size, uint32_t ocrc);
  67
  68 static hammer2_media_data_t media;
  69 static hammer2_blockref_t saved_base;
  70
  71 #define hammer2_icrc32(buf, size)       iscsi_crc32(buf, size)
  72
  73 struct hammer2_fs {
  74         hammer2_blockref_t              sroot;
  75         hammer2_blockset_t              sroot_blockset;
  76 #if defined(TESTING)
  77         int                             fd;
  78 #elif defined(LIBSTAND)
  79         struct open_file                *f;
  80 #elif defined(BOOT2)
  81         /* BOOT2 doesn't use a descriptor */
  82 #else
  83 #error "hammer2: unknown library API"
  84 #endif
  85 };
  86
  87 struct hammer2_inode {
  88         struct hammer2_inode_data       ino;    /* raw inode data */
  89         off_t                           doff;   /* disk inode offset */
  90 };
  91
  92 #ifdef BOOT2
  93
  94 static void
  95 bzero(void *buf, size_t size)
  96 {
  97         for (size_t i = 0; i < size; i++)
  98                 ((char *)buf)[i] = 0;
  99 }
 100
 101 static void
 102 bcopy(void *src, void *dst, size_t size)
 103 {
 104         memcpy(dst, src, size);
 105 }
 106
 107 #if 0
 108 static size_t
 109 strlen(const char *s)
 110 {
 111         size_t l = 0;
 112         for (; *s != 0; s++)
 113                 l++;
 114         return (l);
 115 }
 116 #endif
 117
 118 static int
 119 memcmp(const void *a, const void *b, size_t len)
 120 {
 121         for (size_t p = 0; p < len; p++) {
 122                 int r = ((const char *)a)[p] - ((const char *)b)[p];
 123                 if (r != 0)
 124                         return (r);
 125         }
 126
 127         return (0);
 128 }
 129
 130 #endif
 131
 132 static
 133 off_t
 134 blockoff(hammer2_blockref_t *bref)
 135 {
 136         return(bref->data_off & ~HAMMER2_OFF_MASK_RADIX);
 137 }
 138
 139 static
 140 size_t
 141 blocksize(hammer2_blockref_t *bref)
 142 {
 143         return(1 << (int)(bref->data_off & HAMMER2_OFF_MASK_RADIX));
 144 }
 145
 146 static
 147 hammer2_key_t
 148 hammer2_dirhash(const unsigned char *name, size_t len)
 149 {
 150         const unsigned char *aname = name;
 151         uint32_t crcx;
 152         uint64_t key;
 153         size_t i;
 154         size_t j;
 155
 156         key = 0;
 157
 158         /*
 159          * m32
 160          */
 161         crcx = 0;
 162         for (i = j = 0; i < len; ++i) {
 163                 if (aname[i] == '.' ||
 164                     aname[i] == '-' ||
 165                     aname[i] == '_' ||
 166                     aname[i] == '~') {
 167                         if (i != j)
 168                                 crcx += hammer2_icrc32(aname + j, i - j);
 169                         j = i + 1;
 170                 }
 171         }
 172         if (i != j)
 173                 crcx += hammer2_icrc32(aname + j, i - j);
 174
 175         /*
 176          * The directory hash utilizes the top 32 bits of the 64-bit key.
 177          * Bit 63 must be set to 1.
 178          */
 179         crcx |= 0x80000000U;
 180         key |= (uint64_t)crcx << 32;
 181
 182         /*
 183          * l16 - crc of entire filename
 184          *
 185          * This crc reduces degenerate hash collision conditions
 186          */
 187         crcx = hammer2_icrc32(aname, len);
 188         crcx = crcx ^ (crcx << 16);
 189         key |= crcx & 0xFFFF0000U;
 190
 191         /*
 192          * Set bit 15.  This allows readdir to strip bit 63 so a positive
 193          * 64-bit cookie/offset can always be returned, and still guarantee
 194          * that the values 0x0000-0x7FFF are available for artificial entries.
 195          * ('.' and '..').
 196          */
 197         key |= 0x8000U;
 198
 199         return (key);
 200 }
 201
 202 /*
 203  * Low level read
 204  */
 205 static
 206 int
 207 h2read(struct hammer2_fs *hfs, void *buf, size_t nbytes, off_t off)
 208 {
 209 #if defined(LIBSTAND)
 210         size_t rlen;
 211 #endif
 212         int rc;
 213
 214 #if defined(TESTING)
 215         rc = pread(hfs->fd, &media, nbytes, off);
 216         if (rc == (int)nbytes)
 217                 rc = 0;
 218         else
 219                 rc = -1;
 220 #elif defined(LIBSTAND)
 221         rc = hfs->f->f_dev->dv_strategy(hfs->f->f_devdata, F_READ,
 222                                         off >> DEV_BSHIFT, nbytes,
 223                                         buf, &rlen);
 224         if (rc || rlen != nbytes)
 225                 rc = -1;
 226 #elif defined(BOOT2)
 227         rc = dskread(buf, off >> DEV_BSHIFT, nbytes >> DEV_BSHIFT);
 228         if (rc)
 229                 rc = -1;
 230 #else
 231 #error "hammer2: unknown library API"
 232 #endif
 233         return rc;
 234 }
 235
 236 /*
 237  * Common code
 238  *
 239  * Initialize for HAMMER2 filesystem access given a hammer2_fs with
 240  * its device file descriptor initialized.
 241  */
 242
 243 /*
 244  * Lookup within the block specified by (*base), loading the block from disk
 245  * if necessary.  Locate the first key within the requested range and
 246  * recursively run through indirect blocks as needed.  The caller may loop
 247  * by setting key_beg to *key_ret.
 248  *
 249  * Returns 0 if nothing could be found and the key range has been exhausted.
 250  * returns -1 if a disk error occured.  Otherwise returns the size of the
 251  * data block and returns the data block in *pptr and bref in *bref_ret.
 252  *
 253  * NOTE! When reading file data, the returned bref's key will be the nearest
 254  *       data block we looked up.  The file read procedure must handle any
 255  *       zero-fill or skip.  However, we will truncate the return value to
 256  *       the file size.
 257  */
 258 static int
 259 h2lookup(struct hammer2_fs *hfs, hammer2_blockref_t *base,
 260          hammer2_key_t key_beg, hammer2_key_t key_end,
 261          hammer2_blockref_t *bref_ret, void **pptr)
 262 {
 263         hammer2_blockref_t *bref;
 264         hammer2_blockref_t best;
 265         hammer2_key_t scan_beg;
 266         hammer2_key_t scan_end;
 267         int i;
 268         int rc;
 269         int count;
 270         int dev_boff;
 271         int dev_bsize;
 272
 273         if (base == NULL) {
 274                 saved_base.data_off = (hammer2_off_t)-1;
 275                 return(0);
 276         }
 277         if (base->data_off == (hammer2_off_t)-1)
 278                 return(-1);
 279
 280         /*
 281          * Calculate the number of blockrefs to scan
 282          */
 283         switch(base->type) {
 284         case HAMMER2_BREF_TYPE_VOLUME:
 285                 count = HAMMER2_SET_COUNT;
 286                 break;
 287         case HAMMER2_BREF_TYPE_INODE:
 288                 count = HAMMER2_SET_COUNT;
 289                 break;
 290         case HAMMER2_BREF_TYPE_INDIRECT:
 291                 count = blocksize(base) / sizeof(hammer2_blockref_t);
 292                 break;
 293         }
 294
 295         /*
 296          * Find the best candidate (the lowest blockref within the specified
 297          * range).  The array can be fully set associative so make no ordering
 298          * assumptions.
 299          */
 300 again:
 301         best.key = HAMMER2_KEY_MAX;
 302         best.type = 0;
 303
 304         for (i = 0; i < count; ++i) {
 305                 /*
 306                  * [re]load when returning from our recursion
 307                  */
 308                 if (base->type != HAMMER2_BREF_TYPE_VOLUME &&
 309                     base->data_off != saved_base.data_off) {
 310                         if (h2read(hfs, &media,
 311                                    blocksize(base), blockoff(base))) {
 312                                 return(-1);
 313                         }
 314                         saved_base = *base;
 315                 }
 316
 317                 /*
 318                  * Special case embedded file data
 319                  */
 320                 if (base->type == HAMMER2_BREF_TYPE_INODE) {
 321                         if (media.ipdata.op_flags & HAMMER2_OPFLAG_DIRECTDATA) {
 322                                 *pptr = media.ipdata.u.data;
 323                                 bref_ret->type = HAMMER2_BREF_TYPE_DATA;
 324                                 bref_ret->key = 0;
 325                                 return HAMMER2_EMBEDDED_BYTES;
 326                         }
 327                 }
 328
 329                 /*
 330                  * Calculate the bref in our scan.
 331                  */
 332                 switch(base->type) {
 333                 case HAMMER2_BREF_TYPE_VOLUME:
 334                         bref = &hfs->sroot_blockset.blockref[i];
 335                         break;
 336                 case HAMMER2_BREF_TYPE_INODE:
 337                         bref = &media.ipdata.u.blockset.blockref[i];
 338                         break;
 339                 case HAMMER2_BREF_TYPE_INDIRECT:
 340                         bref = &media.npdata[i];
 341                         break;
 342                 }
 343                 if (bref->type == 0)
 344                         continue;
 345                 if (bref->key > best.key)
 346                         continue;
 347                 scan_beg = bref->key;
 348                 scan_end = scan_beg + ((hammer2_key_t)1 << bref->keybits) - 1;
 349                 if (scan_end >= key_beg && scan_beg <= key_end) {
 350                         best = *bref;
 351                 }
 352         }
 353
 354         /*
 355          * Figure out what to do with the results.
 356          */
 357         switch(best.type) {
 358         case 0:
 359                 /*
 360                  * Return 0
 361                  */
 362                 rc = 0;
 363                 break;
 364         case HAMMER2_BREF_TYPE_INDIRECT:
 365                 /*
 366                  * Matched an indirect block.  If the block turns out to
 367                  * contain nothing we continue the iteration, otherwise
 368                  * we return the data from the recursion.
 369                  *
 370                  * Be sure to handle the overflow case when recalculating
 371                  * key_beg.
 372                  */
 373                 rc = h2lookup(hfs, &best, key_beg, key_end, bref_ret, pptr);
 374                 if (rc == 0) {
 375                         key_beg = best.key +
 376                                   ((hammer2_key_t)1 << best.keybits);
 377                         if (key_beg > best.key && key_beg <= key_end)
 378                                 goto again;
 379                 }
 380                 break;
 381         case HAMMER2_BREF_TYPE_INODE:
 382         case HAMMER2_BREF_TYPE_DATA:
 383                 /*
 384                  * Terminal match.  Leaf elements might not be data-aligned.
 385                  */
 386                 dev_bsize = blocksize(&best);
 387                 if (dev_bsize < HAMMER2_LBUFSIZE)
 388                         dev_bsize = HAMMER2_LBUFSIZE;
 389                 dev_boff = blockoff(&best) -
 390                            (blockoff(&best) & ~HAMMER2_LBUFMASK64);
 391                 if (h2read(hfs, &media, dev_bsize, blockoff(&best) - dev_boff))
 392                         return(-1);
 393                 saved_base.data_off = (hammer2_off_t)-1;
 394                 *bref_ret = best;
 395                 *pptr = media.buf + dev_boff;
 396                 rc = blocksize(&best);
 397                 break;
 398         }
 399         return(rc);
 400 }
 401
 402 static
 403 void
 404 h2resolve(struct hammer2_fs *hfs, const char *path,
 405           hammer2_blockref_t *bref, hammer2_inode_data_t **inop)
 406 {
 407         hammer2_blockref_t bres;
 408         hammer2_inode_data_t *ino;
 409         hammer2_key_t key;
 410         ssize_t bytes;
 411         size_t len;
 412
 413         /*
 414          * Start point (superroot)
 415          */
 416         *bref = hfs->sroot;
 417         if (inop)
 418                 *inop = NULL;
 419
 420         /*
 421          * Iterate path elements
 422          */
 423         while (*path) {
 424                 while (*path == '/')
 425                         ++path;
 426                 if (*path == 0) /* terminal */
 427                         break;
 428
 429                 /*
 430                  * Calculate path element and look for it in the directory
 431                  */
 432                 for (len = 0; path[len]; ++len) {
 433                         if (path[len] == '/')
 434                                 break;
 435                 }
 436                 key = hammer2_dirhash(path, len);
 437                 for (;;) {
 438                         bytes = h2lookup(hfs, bref,
 439                                          key, key | 0xFFFFU,
 440                                          &bres, (void **)&ino);
 441                         if (bytes == 0)
 442                                 break;
 443                         if (len == ino->name_len &&
 444                             memcmp(path, ino->filename, len) == 0) {
 445                                 if (inop)
 446                                         *inop = ino;
 447                                 break;
 448                         }
 449                         key = bres.key + 1;
 450                 }
 451
 452                 /*
 453                  * Lookup failure
 454                  */
 455                 if (bytes == 0) {
 456                         bref->data_off = (hammer2_off_t)-1;
 457                         break;
 458                 }
 459
 460                 /*
 461                  * Check path continuance, inode must be a directory or
 462                  * we fail.
 463                  */
 464                 path += len;
 465                 if (*path && ino->type != HAMMER2_OBJTYPE_DIRECTORY) {
 466                         bref->data_off = (hammer2_off_t)-1;
 467                         break;
 468                 }
 469                 *bref = bres;
 470         }
 471 }
 472
 473 static
 474 ssize_t
 475 h2readfile(struct hammer2_fs *hfs, hammer2_blockref_t *bref,
 476            off_t off, off_t filesize, void *buf, size_t len)
 477 {
 478         hammer2_blockref_t bres;
 479         ssize_t total;
 480         ssize_t bytes;
 481         ssize_t zfill;
 482         char *data;
 483
 484         /*
 485          * EOF edge cases
 486          */
 487         if (off >= filesize)
 488                 return (0);
 489         if (off + len > filesize)
 490                 len = filesize - off;
 491
 492         /*
 493          * Loop until done
 494          */
 495         total = 0;
 496         while (len) {
 497                 /*
 498                  * Find closest bres >= requested offset.
 499                  */
 500                 bytes = h2lookup(hfs, bref, off, off + len - 1,
 501                                  &bres, (void **)&data);
 502
 503                 if (bytes < 0) {
 504                         if (total == 0)
 505                                 total = -1;
 506                         break;
 507                 }
 508
 509                 /*
 510                  * Load the data into the buffer.  First handle a degenerate
 511                  * zero-fill case.
 512                  */
 513                 if (bytes == 0) {
 514                         bzero(buf, len);
 515                         total += len;
 516                         break;
 517                 }
 518
 519                 /*
 520                  * Returned record overlaps to the left of the requested
 521                  * position.  It must overlap in this case or h2lookup()
 522                  * would have returned something else.
 523                  */
 524                 if (bres.key < off) {
 525                         data += off - bres.key;
 526                         bytes -= off - bres.key;
 527                 }
 528
 529                 /*
 530                  * Returned record overlaps to the right of the requested
 531                  * position, handle zero-fill.  Again h2lookup() only returns
 532                  * this case if there is an actual overlap.
 533                  */
 534                 if (bres.key > off) {
 535                         zfill = (ssize_t)(bres.key - off);
 536                         bzero(buf, zfill);
 537                         len -= zfill;
 538                         off += zfill;
 539                         total += zfill;
 540                         buf = (char *)buf + zfill;
 541                 }
 542
 543                 /*
 544                  * Trim returned request before copying.
 545                  */
 546                 if (bytes > len)
 547                         bytes = len;
 548                 bcopy(data, buf, bytes);
 549                 len -= bytes;
 550                 off += bytes;
 551                 total += bytes;
 552                 buf = (char *)buf + bytes;
 553         }
 554         return (total);
 555 }
 556
 557 static
 558 int
 559 h2init(struct hammer2_fs *hfs)
 560 {
 561 #if 0
 562         uint32_t crc0;
 563 #endif
 564         hammer2_tid_t best_tid = 0;
 565         void *data;
 566         off_t off;
 567         int best;
 568         int i;
 569
 570         /*
 571          * Find the best volume header
 572          */
 573         best = -1;
 574         for (i = 0; i < HAMMER2_NUM_VOLHDRS; ++i) {
 575                 off = i * HAMMER2_ZONE_BYTES64;
 576                 if (i)
 577                         no_io_error = 1;
 578                 if (h2read(hfs, &media, sizeof(media.voldata), off))
 579                         continue;
 580                 if (media.voldata.magic != HAMMER2_VOLUME_ID_HBO)
 581                         continue;
 582                 if (best < 0 || best_tid < media.voldata.mirror_tid) {
 583                         best = i;
 584                         best_tid = media.voldata.mirror_tid;
 585                 }
 586         }
 587         no_io_error = 0;
 588         if (best < 0)
 589                 return(-1);
 590
 591         /*
 592          * Reload the best volume header and set up the blockref.
 593          * We messed with media, clear the cache before continuing.
 594          */
 595         off = best * HAMMER2_ZONE_BYTES64;
 596         if (h2read(hfs, &media, sizeof(media.voldata), off))
 597                 return(-1);
 598         hfs->sroot.type = HAMMER2_BREF_TYPE_VOLUME;
 599         hfs->sroot.data_off = off;
 600         hfs->sroot_blockset = media.voldata.sroot_blockset;
 601         h2lookup(hfs, NULL, 0, 0, NULL, NULL);
 602
 603         /*
 604          * Lookup sroot and clear the cache again.
 605          */
 606         h2lookup(hfs, &hfs->sroot, 0, 0, &hfs->sroot, &data);
 607         h2lookup(hfs, NULL, 0, 0, NULL, NULL);
 608
 609         return (0);
 610 }
 611
 612 /************************************************************************
 613  *                              BOOT2 SUPPORT                           *
 614  ************************************************************************
 615  *
 616  */
 617 #ifdef BOOT2
 618
 619 static struct hammer2_fs hfs;
 620
 621 static int
 622 boot2_hammer2_init(void)
 623 {
 624         if (h2init(&hfs))
 625                 return(-1);
 626         return(0);
 627 }
 628
 629 static boot2_ino_t
 630 boot2_hammer2_lookup(const char *path)
 631 {
 632         hammer2_blockref_t bref;
 633
 634         h2resolve(&hfs, path, &bref, NULL);
 635         return ((boot2_ino_t)bref.data_off);
 636 }
 637
 638 static ssize_t
 639 boot2_hammer2_read(boot2_ino_t ino, void *buf, size_t len)
 640 {
 641         hammer2_blockref_t bref;
 642         ssize_t total;
 643
 644         bzero(&bref, sizeof(bref));
 645         bref.type = HAMMER2_BREF_TYPE_INODE;
 646         bref.data_off = ino;
 647
 648         total = h2readfile(&hfs, &bref, fs_off, 0x7FFFFFFF, buf, len);
 649         if (total > 0)
 650                 fs_off += total;
 651         return total;
 652 }
 653
 654 const struct boot2_fsapi boot2_hammer2_api = {
 655         .fsinit = boot2_hammer2_init,
 656         .fslookup = boot2_hammer2_lookup,
 657         .fsread = boot2_hammer2_read
 658 };
 659
 660 #endif
 661
 662 /************************************************************************
 663  *                              BOOT2 SUPPORT                           *
 664  ************************************************************************
 665  *
 666  */
 667 #ifdef LIBSTAND
 668
 669 struct hfile {
 670         struct hammer2_fs hfs;
 671         hammer2_blockref_t bref;
 672         int64_t         fsize;
 673         uint32_t        mode;
 674         uint8_t         type;
 675 };
 676
 677 static
 678 int
 679 hammer2_get_dtype(uint8_t type)
 680 {
 681         switch(type) {
 682         case HAMMER2_OBJTYPE_DIRECTORY:
 683                 return(DT_DIR);
 684         case HAMMER2_OBJTYPE_REGFILE:
 685                 return(DT_REG);
 686         case HAMMER2_OBJTYPE_FIFO:
 687                 return(DT_FIFO);
 688         case HAMMER2_OBJTYPE_CDEV:
 689                 return(DT_CHR);
 690         case HAMMER2_OBJTYPE_BDEV:
 691                 return(DT_BLK);
 692         case HAMMER2_OBJTYPE_SOFTLINK:
 693                 return(DT_LNK);
 694         case HAMMER2_OBJTYPE_HARDLINK:
 695                 return(DT_UNKNOWN);
 696         case HAMMER2_OBJTYPE_SOCKET:
 697                 return(DT_SOCK);
 698         default:
 699                 return(DT_UNKNOWN);
 700         }
 701 }
 702
 703 static
 704 mode_t
 705 hammer2_get_mode(uint8_t type)
 706 {
 707         switch(type) {
 708         case HAMMER2_OBJTYPE_DIRECTORY:
 709                 return(S_IFDIR);
 710         case HAMMER2_OBJTYPE_REGFILE:
 711                 return(S_IFREG);
 712         case HAMMER2_OBJTYPE_FIFO:
 713                 return(S_IFIFO);
 714         case HAMMER2_OBJTYPE_CDEV:
 715                 return(S_IFCHR);
 716         case HAMMER2_OBJTYPE_BDEV:
 717                 return(S_IFBLK);
 718         case HAMMER2_OBJTYPE_SOFTLINK:
 719                 return(S_IFLNK);
 720         case HAMMER2_OBJTYPE_HARDLINK:
 721                 return(0);
 722         case HAMMER2_OBJTYPE_SOCKET:
 723                 return(S_IFSOCK);
 724         default:
 725                 return(0);
 726         }
 727 }
 728
 729 static int
 730 hammer2_open(const char *path, struct open_file *f)
 731 {
 732         struct hfile *hf = malloc(sizeof(*hf));
 733         hammer2_inode_data_t *ipdata;
 734
 735         bzero(hf, sizeof(*hf));
 736         f->f_offset = 0;
 737         f->f_fsdata = hf;
 738         hf->hfs.f = f;
 739
 740         if (h2init(&hf->hfs)) {
 741                 f->f_fsdata = NULL;
 742                 free(hf);
 743                 errno = ENOENT;
 744                 return(-1);
 745         }
 746         h2resolve(&hf->hfs, path, &hf->bref, &ipdata);
 747         if (hf->bref.data_off == (hammer2_off_t)-1 ||
 748             (hf->bref.type != HAMMER2_BREF_TYPE_INODE &&
 749             hf->bref.type != HAMMER2_BREF_TYPE_VOLUME)) {
 750                 f->f_fsdata = NULL;
 751                 free(hf);
 752                 errno = ENOENT;
 753                 return(-1);
 754         }
 755         if (ipdata) {
 756                 hf->fsize = ipdata->size;
 757                 hf->type = ipdata->type;
 758                 hf->mode = ipdata->mode | hammer2_get_mode(ipdata->type);
 759         } else {
 760                 hf->fsize = 0;
 761                 hf->type = HAMMER2_OBJTYPE_DIRECTORY;
 762                 hf->mode = 0755 | S_IFDIR;
 763         }
 764         return(0);
 765 }
 766
 767 static int
 768 hammer2_close(struct open_file *f)
 769 {
 770         struct hfile *hf = f->f_fsdata;
 771
 772         f->f_fsdata = NULL;
 773         if (hf)
 774                 free(hf);
 775         return (0);
 776 }
 777
 778 static int
 779 hammer2_read(struct open_file *f, void *buf, size_t len, size_t *resid)
 780 {
 781         struct hfile *hf = f->f_fsdata;
 782         ssize_t total;
 783         int rc = 0;
 784
 785         total = h2readfile(&hf->hfs, &hf->bref,
 786                            f->f_offset, hf->fsize, buf, len);
 787         if (total < 0) {
 788                 rc = EIO;
 789                 total = 0;
 790         } else {
 791                 f->f_offset += total;
 792                 rc = 0;
 793         }
 794         *resid = len - total;
 795         return rc;
 796 }
 797
 798 static off_t
 799 hammer2_seek(struct open_file *f, off_t offset, int whence)
 800 {
 801         struct hfile *hf = f->f_fsdata;
 802
 803         switch (whence) {
 804         case SEEK_SET:
 805                 f->f_offset = offset;
 806                 break;
 807         case SEEK_CUR:
 808                 f->f_offset += offset;
 809                 break;
 810         case SEEK_END:
 811                 f->f_offset = hf->fsize - offset;
 812                 break;
 813         default:
 814                 return (-1);
 815         }
 816         return (f->f_offset);
 817 }
 818
 819 static int
 820 hammer2_stat(struct open_file *f, struct stat *st)
 821 {
 822         struct hfile *hf = f->f_fsdata;
 823
 824         st->st_mode = hf->mode;
 825         st->st_uid = 0;
 826         st->st_gid = 0;
 827         st->st_size = hf->fsize;
 828
 829         return (0);
 830 }
 831
 832 static int
 833 hammer2_readdir(struct open_file *f, struct dirent *den)
 834 {
 835         struct hfile *hf = f->f_fsdata;
 836         hammer2_blockref_t bres;
 837         hammer2_inode_data_t *ipdata;
 838         int bytes;
 839
 840         for (;;) {
 841                 bytes = h2lookup(&hf->hfs, &hf->bref,
 842                                  f->f_offset | HAMMER2_DIRHASH_VISIBLE,
 843                                  HAMMER2_KEY_MAX,
 844                                  &bres, (void **)&ipdata);
 845                 if (bytes <= 0)
 846                         break;
 847                 den->d_namlen = ipdata->name_len;
 848                 den->d_type = hammer2_get_dtype(ipdata->type);
 849                 den->d_ino = ipdata->inum;
 850                 bcopy(ipdata->filename, den->d_name, den->d_namlen);
 851                 den->d_name[den->d_namlen] = 0;
 852
 853                 f->f_offset = bres.key + 1;
 854
 855                 return(0);
 856         }
 857         return ENOENT;
 858 }
 859
 860 struct fs_ops hammer_fsops = {
 861         "hammer2",
 862         hammer2_open,
 863         hammer2_close,
 864         hammer2_read,
 865         null_write,
 866         hammer2_seek,
 867         hammer2_stat,
 868         hammer2_readdir
 869 };
 870
 871 #endif