fs/hfsplus/extents.c

   1 /*
   2  *  linux/fs/hfsplus/extents.c
   3  *
   4  * Copyright (C) 2001
   5  * Brad Boyer (flar@allandria.com)
   6  * (C) 2003 Ardis Technologies <roman@ardistech.com>
   7  *
   8  * Handling of Extents both in catalog and extents overflow trees
   9  */
  10
  11 #include <linux/errno.h>
  12 #include <linux/fs.h>
  13 #include <linux/pagemap.h>
  14
  15 #include "hfsplus_fs.h"
  16 #include "hfsplus_raw.h"
  17
  18 /* Compare two extents keys, returns 0 on same, pos/neg for difference */
  19 int hfsplus_ext_cmp_key(const hfsplus_btree_key *k1,
  20                         const hfsplus_btree_key *k2)
  21 {
  22         __be32 k1id, k2id;
  23         __be32 k1s, k2s;
  24
  25         k1id = k1->ext.cnid;
  26         k2id = k2->ext.cnid;
  27         if (k1id != k2id)
  28                 return be32_to_cpu(k1id) < be32_to_cpu(k2id) ? -1 : 1;
  29
  30         if (k1->ext.fork_type != k2->ext.fork_type)
  31                 return k1->ext.fork_type < k2->ext.fork_type ? -1 : 1;
  32
  33         k1s = k1->ext.start_block;
  34         k2s = k2->ext.start_block;
  35         if (k1s == k2s)
  36                 return 0;
  37         return be32_to_cpu(k1s) < be32_to_cpu(k2s) ? -1 : 1;
  38 }
  39
  40 static void hfsplus_ext_build_key(hfsplus_btree_key *key, u32 cnid,
  41                                   u32 block, u8 type)
  42 {
  43         key->key_len = cpu_to_be16(HFSPLUS_EXT_KEYLEN - 2);
  44         key->ext.cnid = cpu_to_be32(cnid);
  45         key->ext.start_block = cpu_to_be32(block);
  46         key->ext.fork_type = type;
  47         key->ext.pad = 0;
  48 }
  49
  50 static u32 hfsplus_ext_find_block(struct hfsplus_extent *ext, u32 off)
  51 {
  52         int i;
  53         u32 count;
  54
  55         for (i = 0; i < 8; ext++, i++) {
  56                 count = be32_to_cpu(ext->block_count);
  57                 if (off < count)
  58                         return be32_to_cpu(ext->start_block) + off;
  59                 off -= count;
  60         }
  61         /* panic? */
  62         return 0;
  63 }
  64
  65 static int hfsplus_ext_block_count(struct hfsplus_extent *ext)
  66 {
  67         int i;
  68         u32 count = 0;
  69
  70         for (i = 0; i < 8; ext++, i++)
  71                 count += be32_to_cpu(ext->block_count);
  72         return count;
  73 }
  74
  75 static u32 hfsplus_ext_lastblock(struct hfsplus_extent *ext)
  76 {
  77         int i;
  78
  79         ext += 7;
  80         for (i = 0; i < 7; ext--, i++)
  81                 if (ext->block_count)
  82                         break;
  83         return be32_to_cpu(ext->start_block) + be32_to_cpu(ext->block_count);
  84 }
  85
  86 static int __hfsplus_ext_write_extent(struct inode *inode,
  87                 struct hfs_find_data *fd)
  88 {
  89         struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
  90         int res;
  91
  92         WARN_ON(!mutex_is_locked(&hip->extents_lock));
  93
  94         hfsplus_ext_build_key(fd->search_key, inode->i_ino, hip->cached_start,
  95                               HFSPLUS_IS_RSRC(inode) ?
  96                                 HFSPLUS_TYPE_RSRC : HFSPLUS_TYPE_DATA);
  97
  98         res = hfs_brec_find(fd, hfs_find_rec_by_key);
  99         if (hip->extent_state & HFSPLUS_EXT_NEW) {
 100                 if (res != -ENOENT)
 101                         return res;
 102                 hfs_brec_insert(fd, hip->cached_extents,
 103                                 sizeof(hfsplus_extent_rec));
 104                 hip->extent_state &= ~(HFSPLUS_EXT_DIRTY | HFSPLUS_EXT_NEW);
 105         } else {
 106                 if (res)
 107                         return res;
 108                 hfs_bnode_write(fd->bnode, hip->cached_extents,
 109                                 fd->entryoffset, fd->entrylength);
 110                 hip->extent_state &= ~HFSPLUS_EXT_DIRTY;
 111         }
 112
 113         /*
 114          * We can't just use hfsplus_mark_inode_dirty here, because we
 115          * also get called from hfsplus_write_inode, which should not
 116          * redirty the inode.  Instead the callers have to be careful
 117          * to explicily mark the inode dirty, too.
 118          */
 119         set_bit(HFSPLUS_I_EXT_DIRTY, &hip->flags);
 120
 121         return 0;
 122 }
 123
 124 static int hfsplus_ext_write_extent_locked(struct inode *inode)
 125 {
 126         int res = 0;
 127
 128         if (HFSPLUS_I(inode)->extent_state & HFSPLUS_EXT_DIRTY) {
 129                 struct hfs_find_data fd;
 130
 131                 res = hfs_find_init(HFSPLUS_SB(inode->i_sb)->ext_tree, &fd);
 132                 if (res)
 133                         return res;
 134                 res = __hfsplus_ext_write_extent(inode, &fd);
 135                 hfs_find_exit(&fd);
 136         }
 137         return res;
 138 }
 139
 140 int hfsplus_ext_write_extent(struct inode *inode)
 141 {
 142         int res;
 143
 144         mutex_lock(&HFSPLUS_I(inode)->extents_lock);
 145         res = hfsplus_ext_write_extent_locked(inode);
 146         mutex_unlock(&HFSPLUS_I(inode)->extents_lock);
 147
 148         return res;
 149 }
 150
 151 static inline int __hfsplus_ext_read_extent(struct hfs_find_data *fd,
 152                                             struct hfsplus_extent *extent,
 153                                             u32 cnid, u32 block, u8 type)
 154 {
 155         int res;
 156
 157         hfsplus_ext_build_key(fd->search_key, cnid, block, type);
 158         fd->key->ext.cnid = 0;
 159         res = hfs_brec_find(fd, hfs_find_rec_by_key);
 160         if (res && res != -ENOENT)
 161                 return res;
 162         if (fd->key->ext.cnid != fd->search_key->ext.cnid ||
 163             fd->key->ext.fork_type != fd->search_key->ext.fork_type)
 164                 return -ENOENT;
 165         if (fd->entrylength != sizeof(hfsplus_extent_rec))
 166                 return -EIO;
 167         hfs_bnode_read(fd->bnode, extent, fd->entryoffset,
 168                 sizeof(hfsplus_extent_rec));
 169         return 0;
 170 }
 171
 172 static inline int __hfsplus_ext_cache_extent(struct hfs_find_data *fd,
 173                 struct inode *inode, u32 block)
 174 {
 175         struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
 176         int res;
 177
 178         WARN_ON(!mutex_is_locked(&hip->extents_lock));
 179
 180         if (hip->extent_state & HFSPLUS_EXT_DIRTY) {
 181                 res = __hfsplus_ext_write_extent(inode, fd);
 182                 if (res)
 183                         return res;
 184         }
 185
 186         res = __hfsplus_ext_read_extent(fd, hip->cached_extents, inode->i_ino,
 187                                         block, HFSPLUS_IS_RSRC(inode) ?
 188                                                 HFSPLUS_TYPE_RSRC :
 189                                                 HFSPLUS_TYPE_DATA);
 190         if (!res) {
 191                 hip->cached_start = be32_to_cpu(fd->key->ext.start_block);
 192                 hip->cached_blocks =
 193                         hfsplus_ext_block_count(hip->cached_extents);
 194         } else {
 195                 hip->cached_start = hip->cached_blocks = 0;
 196                 hip->extent_state &= ~(HFSPLUS_EXT_DIRTY | HFSPLUS_EXT_NEW);
 197         }
 198         return res;
 199 }
 200
 201 static int hfsplus_ext_read_extent(struct inode *inode, u32 block)
 202 {
 203         struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
 204         struct hfs_find_data fd;
 205         int res;
 206
 207         if (block >= hip->cached_start &&
 208             block < hip->cached_start + hip->cached_blocks)
 209                 return 0;
 210
 211         res = hfs_find_init(HFSPLUS_SB(inode->i_sb)->ext_tree, &fd);
 212         if (!res) {
 213                 res = __hfsplus_ext_cache_extent(&fd, inode, block);
 214                 hfs_find_exit(&fd);
 215         }
 216         return res;
 217 }
 218
 219 /* Get a block at iblock for inode, possibly allocating if create */
 220 int hfsplus_get_block(struct inode *inode, sector_t iblock,
 221                       struct buffer_head *bh_result, int create)
 222 {
 223         struct super_block *sb = inode->i_sb;
 224         struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb);
 225         struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
 226         int res = -EIO;
 227         u32 ablock, dblock, mask;
 228         sector_t sector;
 229         int was_dirty = 0;
 230
 231         /* Convert inode block to disk allocation block */
 232         ablock = iblock >> sbi->fs_shift;
 233
 234         if (iblock >= hip->fs_blocks) {
 235                 if (iblock > hip->fs_blocks || !create)
 236                         return -EIO;
 237                 if (ablock >= hip->alloc_blocks) {
 238                         res = hfsplus_file_extend(inode, false);
 239                         if (res)
 240                                 return res;
 241                 }
 242         } else
 243                 create = 0;
 244
 245         if (ablock < hip->first_blocks) {
 246                 dblock = hfsplus_ext_find_block(hip->first_extents, ablock);
 247                 goto done;
 248         }
 249
 250         if (inode->i_ino == HFSPLUS_EXT_CNID)
 251                 return -EIO;
 252
 253         mutex_lock(&hip->extents_lock);
 254
 255         /*
 256          * hfsplus_ext_read_extent will write out a cached extent into
 257          * the extents btree.  In that case we may have to mark the inode
 258          * dirty even for a pure read of an extent here.
 259          */
 260         was_dirty = (hip->extent_state & HFSPLUS_EXT_DIRTY);
 261         res = hfsplus_ext_read_extent(inode, ablock);
 262         if (res) {
 263                 mutex_unlock(&hip->extents_lock);
 264                 return -EIO;
 265         }
 266         dblock = hfsplus_ext_find_block(hip->cached_extents,
 267                                         ablock - hip->cached_start);
 268         mutex_unlock(&hip->extents_lock);
 269
 270 done:
 271         hfs_dbg(EXTENT, "get_block(%lu): %llu - %u\n",
 272                 inode->i_ino, (long long)iblock, dblock);
 273
 274         mask = (1 << sbi->fs_shift) - 1;
 275         sector = ((sector_t)dblock << sbi->fs_shift) +
 276                   sbi->blockoffset + (iblock & mask);
 277         map_bh(bh_result, sb, sector);
 278
 279         if (create) {
 280                 set_buffer_new(bh_result);
 281                 hip->phys_size += sb->s_blocksize;
 282                 hip->fs_blocks++;
 283                 inode_add_bytes(inode, sb->s_blocksize);
 284         }
 285         if (create || was_dirty)
 286                 mark_inode_dirty(inode);
 287         return 0;
 288 }
 289
 290 static void hfsplus_dump_extent(struct hfsplus_extent *extent)
 291 {
 292         int i;
 293
 294         hfs_dbg(EXTENT, "   ");
 295         for (i = 0; i < 8; i++)
 296                 hfs_dbg_cont(EXTENT, " %u:%u",
 297                              be32_to_cpu(extent[i].start_block),
 298                              be32_to_cpu(extent[i].block_count));
 299         hfs_dbg_cont(EXTENT, "\n");
 300 }
 301
 302 static int hfsplus_add_extent(struct hfsplus_extent *extent, u32 offset,
 303                               u32 alloc_block, u32 block_count)
 304 {
 305         u32 count, start;
 306         int i;
 307
 308         hfsplus_dump_extent(extent);
 309         for (i = 0; i < 8; extent++, i++) {
 310                 count = be32_to_cpu(extent->block_count);
 311                 if (offset == count) {
 312                         start = be32_to_cpu(extent->start_block);
 313                         if (alloc_block != start + count) {
 314                                 if (++i >= 8)
 315                                         return -ENOSPC;
 316                                 extent++;
 317                                 extent->start_block = cpu_to_be32(alloc_block);
 318                         } else
 319                                 block_count += count;
 320                         extent->block_count = cpu_to_be32(block_count);
 321                         return 0;
 322                 } else if (offset < count)
 323                         break;
 324                 offset -= count;
 325         }
 326         /* panic? */
 327         return -EIO;
 328 }
 329
 330 static int hfsplus_free_extents(struct super_block *sb,
 331                                 struct hfsplus_extent *extent,
 332                                 u32 offset, u32 block_nr)
 333 {
 334         u32 count, start;
 335         int i;
 336         int err = 0;
 337
 338         hfsplus_dump_extent(extent);
 339         for (i = 0; i < 8; extent++, i++) {
 340                 count = be32_to_cpu(extent->block_count);
 341                 if (offset == count)
 342                         goto found;
 343                 else if (offset < count)
 344                         break;
 345                 offset -= count;
 346         }
 347         /* panic? */
 348         return -EIO;
 349 found:
 350         for (;;) {
 351                 start = be32_to_cpu(extent->start_block);
 352                 if (count <= block_nr) {
 353                         err = hfsplus_block_free(sb, start, count);
 354                         if (err) {
 355                                 pr_err("can't free extent\n");
 356                                 hfs_dbg(EXTENT, " start: %u count: %u\n",
 357                                         start, count);
 358                         }
 359                         extent->block_count = 0;
 360                         extent->start_block = 0;
 361                         block_nr -= count;
 362                 } else {
 363                         count -= block_nr;
 364                         err = hfsplus_block_free(sb, start + count, block_nr);
 365                         if (err) {
 366                                 pr_err("can't free extent\n");
 367                                 hfs_dbg(EXTENT, " start: %u count: %u\n",
 368                                         start, count);
 369                         }
 370                         extent->block_count = cpu_to_be32(count);
 371                         block_nr = 0;
 372                 }
 373                 if (!block_nr || !i) {
 374                         /*
 375                          * Try to free all extents and
 376                          * return only last error
 377                          */
 378                         return err;
 379                 }
 380                 i--;
 381                 extent--;
 382                 count = be32_to_cpu(extent->block_count);
 383         }
 384 }
 385
 386 int hfsplus_free_fork(struct super_block *sb, u32 cnid,
 387                 struct hfsplus_fork_raw *fork, int type)
 388 {
 389         struct hfs_find_data fd;
 390         hfsplus_extent_rec ext_entry;
 391         u32 total_blocks, blocks, start;
 392         int res, i;
 393
 394         total_blocks = be32_to_cpu(fork->total_blocks);
 395         if (!total_blocks)
 396                 return 0;
 397
 398         blocks = 0;
 399         for (i = 0; i < 8; i++)
 400                 blocks += be32_to_cpu(fork->extents[i].block_count);
 401
 402         res = hfsplus_free_extents(sb, fork->extents, blocks, blocks);
 403         if (res)
 404                 return res;
 405         if (total_blocks == blocks)
 406                 return 0;
 407
 408         res = hfs_find_init(HFSPLUS_SB(sb)->ext_tree, &fd);
 409         if (res)
 410                 return res;
 411         do {
 412                 res = __hfsplus_ext_read_extent(&fd, ext_entry, cnid,
 413                                                 total_blocks, type);
 414                 if (res)
 415                         break;
 416                 start = be32_to_cpu(fd.key->ext.start_block);
 417                 hfsplus_free_extents(sb, ext_entry,
 418                                      total_blocks - start,
 419                                      total_blocks);
 420                 hfs_brec_remove(&fd);
 421                 total_blocks = start;
 422         } while (total_blocks > blocks);
 423         hfs_find_exit(&fd);
 424
 425         return res;
 426 }
 427
 428 int hfsplus_file_extend(struct inode *inode, bool zeroout)
 429 {
 430         struct super_block *sb = inode->i_sb;
 431         struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb);
 432         struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
 433         u32 start, len, goal;
 434         int res;
 435
 436         if (sbi->alloc_file->i_size * 8 <
 437             sbi->total_blocks - sbi->free_blocks + 8) {
 438                 /* extend alloc file */
 439                 pr_err("extend alloc file! (%llu,%u,%u)\n",
 440                        sbi->alloc_file->i_size * 8,
 441                        sbi->total_blocks, sbi->free_blocks);
 442                 return -ENOSPC;
 443         }
 444
 445         mutex_lock(&hip->extents_lock);
 446         if (hip->alloc_blocks == hip->first_blocks)
 447                 goal = hfsplus_ext_lastblock(hip->first_extents);
 448         else {
 449                 res = hfsplus_ext_read_extent(inode, hip->alloc_blocks);
 450                 if (res)
 451                         goto out;
 452                 goal = hfsplus_ext_lastblock(hip->cached_extents);
 453         }
 454
 455         len = hip->clump_blocks;
 456         start = hfsplus_block_allocate(sb, sbi->total_blocks, goal, &len);
 457         if (start >= sbi->total_blocks) {
 458                 start = hfsplus_block_allocate(sb, goal, 0, &len);
 459                 if (start >= goal) {
 460                         res = -ENOSPC;
 461                         goto out;
 462                 }
 463         }
 464
 465         if (zeroout) {
 466                 res = sb_issue_zeroout(sb, start, len, GFP_NOFS);
 467                 if (res)
 468                         goto out;
 469         }
 470
 471         hfs_dbg(EXTENT, "extend %lu: %u,%u\n", inode->i_ino, start, len);
 472
 473         if (hip->alloc_blocks <= hip->first_blocks) {
 474                 if (!hip->first_blocks) {
 475                         hfs_dbg(EXTENT, "first extents\n");
 476                         /* no extents yet */
 477                         hip->first_extents[0].start_block = cpu_to_be32(start);
 478                         hip->first_extents[0].block_count = cpu_to_be32(len);
 479                         res = 0;
 480                 } else {
 481                         /* try to append to extents in inode */
 482                         res = hfsplus_add_extent(hip->first_extents,
 483                                                  hip->alloc_blocks,
 484                                                  start, len);
 485                         if (res == -ENOSPC)
 486                                 goto insert_extent;
 487                 }
 488                 if (!res) {
 489                         hfsplus_dump_extent(hip->first_extents);
 490                         hip->first_blocks += len;
 491                 }
 492         } else {
 493                 res = hfsplus_add_extent(hip->cached_extents,
 494                                          hip->alloc_blocks - hip->cached_start,
 495                                          start, len);
 496                 if (!res) {
 497                         hfsplus_dump_extent(hip->cached_extents);
 498                         hip->extent_state |= HFSPLUS_EXT_DIRTY;
 499                         hip->cached_blocks += len;
 500                 } else if (res == -ENOSPC)
 501                         goto insert_extent;
 502         }
 503 out:
 504         if (!res) {
 505                 hip->alloc_blocks += len;
 506                 mutex_unlock(&hip->extents_lock);
 507                 hfsplus_mark_inode_dirty(inode, HFSPLUS_I_ALLOC_DIRTY);
 508                 return 0;
 509         }
 510         mutex_unlock(&hip->extents_lock);
 511         return res;
 512
 513 insert_extent:
 514         hfs_dbg(EXTENT, "insert new extent\n");
 515         res = hfsplus_ext_write_extent_locked(inode);
 516         if (res)
 517                 goto out;
 518
 519         memset(hip->cached_extents, 0, sizeof(hfsplus_extent_rec));
 520         hip->cached_extents[0].start_block = cpu_to_be32(start);
 521         hip->cached_extents[0].block_count = cpu_to_be32(len);
 522         hfsplus_dump_extent(hip->cached_extents);
 523         hip->extent_state |= HFSPLUS_EXT_DIRTY | HFSPLUS_EXT_NEW;
 524         hip->cached_start = hip->alloc_blocks;
 525         hip->cached_blocks = len;
 526
 527         res = 0;
 528         goto out;
 529 }
 530
 531 void hfsplus_file_truncate(struct inode *inode)
 532 {
 533         struct super_block *sb = inode->i_sb;
 534         struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
 535         struct hfs_find_data fd;
 536         u32 alloc_cnt, blk_cnt, start;
 537         int res;
 538
 539         hfs_dbg(INODE, "truncate: %lu, %llu -> %llu\n",
 540                 inode->i_ino, (long long)hip->phys_size, inode->i_size);
 541
 542         if (inode->i_size > hip->phys_size) {
 543                 struct address_space *mapping = inode->i_mapping;
 544                 struct page *page;
 545                 void *fsdata;
 546                 loff_t size = inode->i_size;
 547
 548                 res = pagecache_write_begin(NULL, mapping, size, 0, 0,
 549                                             &page, &fsdata);
 550                 if (res)
 551                         return;
 552                 res = pagecache_write_end(NULL, mapping, size,
 553                         0, 0, page, fsdata);
 554                 if (res < 0)
 555                         return;
 556                 mark_inode_dirty(inode);
 557                 return;
 558         } else if (inode->i_size == hip->phys_size)
 559                 return;
 560
 561         blk_cnt = (inode->i_size + HFSPLUS_SB(sb)->alloc_blksz - 1) >>
 562                         HFSPLUS_SB(sb)->alloc_blksz_shift;
 563
 564         mutex_lock(&hip->extents_lock);
 565
 566         alloc_cnt = hip->alloc_blocks;
 567         if (blk_cnt == alloc_cnt)
 568                 goto out_unlock;
 569
 570         res = hfs_find_init(HFSPLUS_SB(sb)->ext_tree, &fd);
 571         if (res) {
 572                 mutex_unlock(&hip->extents_lock);
 573                 /* XXX: We lack error handling of hfsplus_file_truncate() */
 574                 return;
 575         }
 576         while (1) {
 577                 if (alloc_cnt == hip->first_blocks) {
 578                         hfsplus_free_extents(sb, hip->first_extents,
 579                                              alloc_cnt, alloc_cnt - blk_cnt);
 580                         hfsplus_dump_extent(hip->first_extents);
 581                         hip->first_blocks = blk_cnt;
 582                         break;
 583                 }
 584                 res = __hfsplus_ext_cache_extent(&fd, inode, alloc_cnt);
 585                 if (res)
 586                         break;
 587                 start = hip->cached_start;
 588                 hfsplus_free_extents(sb, hip->cached_extents,
 589                                      alloc_cnt - start, alloc_cnt - blk_cnt);
 590                 hfsplus_dump_extent(hip->cached_extents);
 591                 if (blk_cnt > start) {
 592                         hip->extent_state |= HFSPLUS_EXT_DIRTY;
 593                         break;
 594                 }
 595                 alloc_cnt = start;
 596                 hip->cached_start = hip->cached_blocks = 0;
 597                 hip->extent_state &= ~(HFSPLUS_EXT_DIRTY | HFSPLUS_EXT_NEW);
 598                 hfs_brec_remove(&fd);
 599         }
 600         hfs_find_exit(&fd);
 601
 602         hip->alloc_blocks = blk_cnt;
 603 out_unlock:
 604         mutex_unlock(&hip->extents_lock);
 605         hip->phys_size = inode->i_size;
 606         hip->fs_blocks = (inode->i_size + sb->s_blocksize - 1) >>
 607                 sb->s_blocksize_bits;
 608         inode_set_bytes(inode, hip->fs_blocks << sb->s_blocksize_bits);
 609         hfsplus_mark_inode_dirty(inode, HFSPLUS_I_ALLOC_DIRTY);
 610 }