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                 /* Fail early and avoid ENOSPC during the btree operation */
 103                 res = hfs_bmap_reserve(fd->tree, fd->tree->depth + 1);
 104                 if (res)
 105                         return res;
 106                 hfs_brec_insert(fd, hip->cached_extents,
 107                                 sizeof(hfsplus_extent_rec));
 108                 hip->extent_state &= ~(HFSPLUS_EXT_DIRTY | HFSPLUS_EXT_NEW);
 109         } else {
 110                 if (res)
 111                         return res;
 112                 hfs_bnode_write(fd->bnode, hip->cached_extents,
 113                                 fd->entryoffset, fd->entrylength);
 114                 hip->extent_state &= ~HFSPLUS_EXT_DIRTY;
 115         }
 116
 117         /*
 118          * We can't just use hfsplus_mark_inode_dirty here, because we
 119          * also get called from hfsplus_write_inode, which should not
 120          * redirty the inode.  Instead the callers have to be careful
 121          * to explicily mark the inode dirty, too.
 122          */
 123         set_bit(HFSPLUS_I_EXT_DIRTY, &hip->flags);
 124
 125         return 0;
 126 }
 127
 128 static int hfsplus_ext_write_extent_locked(struct inode *inode)
 129 {
 130         int res = 0;
 131
 132         if (HFSPLUS_I(inode)->extent_state & HFSPLUS_EXT_DIRTY) {
 133                 struct hfs_find_data fd;
 134
 135                 res = hfs_find_init(HFSPLUS_SB(inode->i_sb)->ext_tree, &fd);
 136                 if (res)
 137                         return res;
 138                 res = __hfsplus_ext_write_extent(inode, &fd);
 139                 hfs_find_exit(&fd);
 140         }
 141         return res;
 142 }
 143
 144 int hfsplus_ext_write_extent(struct inode *inode)
 145 {
 146         int res;
 147
 148         mutex_lock(&HFSPLUS_I(inode)->extents_lock);
 149         res = hfsplus_ext_write_extent_locked(inode);
 150         mutex_unlock(&HFSPLUS_I(inode)->extents_lock);
 151
 152         return res;
 153 }
 154
 155 static inline int __hfsplus_ext_read_extent(struct hfs_find_data *fd,
 156                                             struct hfsplus_extent *extent,
 157                                             u32 cnid, u32 block, u8 type)
 158 {
 159         int res;
 160
 161         hfsplus_ext_build_key(fd->search_key, cnid, block, type);
 162         fd->key->ext.cnid = 0;
 163         res = hfs_brec_find(fd, hfs_find_rec_by_key);
 164         if (res && res != -ENOENT)
 165                 return res;
 166         if (fd->key->ext.cnid != fd->search_key->ext.cnid ||
 167             fd->key->ext.fork_type != fd->search_key->ext.fork_type)
 168                 return -ENOENT;
 169         if (fd->entrylength != sizeof(hfsplus_extent_rec))
 170                 return -EIO;
 171         hfs_bnode_read(fd->bnode, extent, fd->entryoffset,
 172                 sizeof(hfsplus_extent_rec));
 173         return 0;
 174 }
 175
 176 static inline int __hfsplus_ext_cache_extent(struct hfs_find_data *fd,
 177                 struct inode *inode, u32 block)
 178 {
 179         struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
 180         int res;
 181
 182         WARN_ON(!mutex_is_locked(&hip->extents_lock));
 183
 184         if (hip->extent_state & HFSPLUS_EXT_DIRTY) {
 185                 res = __hfsplus_ext_write_extent(inode, fd);
 186                 if (res)
 187                         return res;
 188         }
 189
 190         res = __hfsplus_ext_read_extent(fd, hip->cached_extents, inode->i_ino,
 191                                         block, HFSPLUS_IS_RSRC(inode) ?
 192                                                 HFSPLUS_TYPE_RSRC :
 193                                                 HFSPLUS_TYPE_DATA);
 194         if (!res) {
 195                 hip->cached_start = be32_to_cpu(fd->key->ext.start_block);
 196                 hip->cached_blocks =
 197                         hfsplus_ext_block_count(hip->cached_extents);
 198         } else {
 199                 hip->cached_start = hip->cached_blocks = 0;
 200                 hip->extent_state &= ~(HFSPLUS_EXT_DIRTY | HFSPLUS_EXT_NEW);
 201         }
 202         return res;
 203 }
 204
 205 static int hfsplus_ext_read_extent(struct inode *inode, u32 block)
 206 {
 207         struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
 208         struct hfs_find_data fd;
 209         int res;
 210
 211         if (block >= hip->cached_start &&
 212             block < hip->cached_start + hip->cached_blocks)
 213                 return 0;
 214
 215         res = hfs_find_init(HFSPLUS_SB(inode->i_sb)->ext_tree, &fd);
 216         if (!res) {
 217                 res = __hfsplus_ext_cache_extent(&fd, inode, block);
 218                 hfs_find_exit(&fd);
 219         }
 220         return res;
 221 }
 222
 223 /* Get a block at iblock for inode, possibly allocating if create */
 224 int hfsplus_get_block(struct inode *inode, sector_t iblock,
 225                       struct buffer_head *bh_result, int create)
 226 {
 227         struct super_block *sb = inode->i_sb;
 228         struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb);
 229         struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
 230         int res = -EIO;
 231         u32 ablock, dblock, mask;
 232         sector_t sector;
 233         int was_dirty = 0;
 234
 235         /* Convert inode block to disk allocation block */
 236         ablock = iblock >> sbi->fs_shift;
 237
 238         if (iblock >= hip->fs_blocks) {
 239                 if (!create)
 240                         return 0;
 241                 if (iblock > hip->fs_blocks)
 242                         return -EIO;
 243                 if (ablock >= hip->alloc_blocks) {
 244                         res = hfsplus_file_extend(inode, false);
 245                         if (res)
 246                                 return res;
 247                 }
 248         } else
 249                 create = 0;
 250
 251         if (ablock < hip->first_blocks) {
 252                 dblock = hfsplus_ext_find_block(hip->first_extents, ablock);
 253                 goto done;
 254         }
 255
 256         if (inode->i_ino == HFSPLUS_EXT_CNID)
 257                 return -EIO;
 258
 259         mutex_lock(&hip->extents_lock);
 260
 261         /*
 262          * hfsplus_ext_read_extent will write out a cached extent into
 263          * the extents btree.  In that case we may have to mark the inode
 264          * dirty even for a pure read of an extent here.
 265          */
 266         was_dirty = (hip->extent_state & HFSPLUS_EXT_DIRTY);
 267         res = hfsplus_ext_read_extent(inode, ablock);
 268         if (res) {
 269                 mutex_unlock(&hip->extents_lock);
 270                 return -EIO;
 271         }
 272         dblock = hfsplus_ext_find_block(hip->cached_extents,
 273                                         ablock - hip->cached_start);
 274         mutex_unlock(&hip->extents_lock);
 275
 276 done:
 277         hfs_dbg(EXTENT, "get_block(%lu): %llu - %u\n",
 278                 inode->i_ino, (long long)iblock, dblock);
 279
 280         mask = (1 << sbi->fs_shift) - 1;
 281         sector = ((sector_t)dblock << sbi->fs_shift) +
 282                   sbi->blockoffset + (iblock & mask);
 283         map_bh(bh_result, sb, sector);
 284
 285         if (create) {
 286                 set_buffer_new(bh_result);
 287                 hip->phys_size += sb->s_blocksize;
 288                 hip->fs_blocks++;
 289                 inode_add_bytes(inode, sb->s_blocksize);
 290         }
 291         if (create || was_dirty)
 292                 mark_inode_dirty(inode);
 293         return 0;
 294 }
 295
 296 static void hfsplus_dump_extent(struct hfsplus_extent *extent)
 297 {
 298         int i;
 299
 300         hfs_dbg(EXTENT, "   ");
 301         for (i = 0; i < 8; i++)
 302                 hfs_dbg_cont(EXTENT, " %u:%u",
 303                              be32_to_cpu(extent[i].start_block),
 304                              be32_to_cpu(extent[i].block_count));
 305         hfs_dbg_cont(EXTENT, "\n");
 306 }
 307
 308 static int hfsplus_add_extent(struct hfsplus_extent *extent, u32 offset,
 309                               u32 alloc_block, u32 block_count)
 310 {
 311         u32 count, start;
 312         int i;
 313
 314         hfsplus_dump_extent(extent);
 315         for (i = 0; i < 8; extent++, i++) {
 316                 count = be32_to_cpu(extent->block_count);
 317                 if (offset == count) {
 318                         start = be32_to_cpu(extent->start_block);
 319                         if (alloc_block != start + count) {
 320                                 if (++i >= 8)
 321                                         return -ENOSPC;
 322                                 extent++;
 323                                 extent->start_block = cpu_to_be32(alloc_block);
 324                         } else
 325                                 block_count += count;
 326                         extent->block_count = cpu_to_be32(block_count);
 327                         return 0;
 328                 } else if (offset < count)
 329                         break;
 330                 offset -= count;
 331         }
 332         /* panic? */
 333         return -EIO;
 334 }
 335
 336 static int hfsplus_free_extents(struct super_block *sb,
 337                                 struct hfsplus_extent *extent,
 338                                 u32 offset, u32 block_nr)
 339 {
 340         u32 count, start;
 341         int i;
 342         int err = 0;
 343
 344         hfsplus_dump_extent(extent);
 345         for (i = 0; i < 8; extent++, i++) {
 346                 count = be32_to_cpu(extent->block_count);
 347                 if (offset == count)
 348                         goto found;
 349                 else if (offset < count)
 350                         break;
 351                 offset -= count;
 352         }
 353         /* panic? */
 354         return -EIO;
 355 found:
 356         for (;;) {
 357                 start = be32_to_cpu(extent->start_block);
 358                 if (count <= block_nr) {
 359                         err = hfsplus_block_free(sb, start, count);
 360                         if (err) {
 361                                 pr_err("can't free extent\n");
 362                                 hfs_dbg(EXTENT, " start: %u count: %u\n",
 363                                         start, count);
 364                         }
 365                         extent->block_count = 0;
 366                         extent->start_block = 0;
 367                         block_nr -= count;
 368                 } else {
 369                         count -= block_nr;
 370                         err = hfsplus_block_free(sb, start + count, block_nr);
 371                         if (err) {
 372                                 pr_err("can't free extent\n");
 373                                 hfs_dbg(EXTENT, " start: %u count: %u\n",
 374                                         start, count);
 375                         }
 376                         extent->block_count = cpu_to_be32(count);
 377                         block_nr = 0;
 378                 }
 379                 if (!block_nr || !i) {
 380                         /*
 381                          * Try to free all extents and
 382                          * return only last error
 383                          */
 384                         return err;
 385                 }
 386                 i--;
 387                 extent--;
 388                 count = be32_to_cpu(extent->block_count);
 389         }
 390 }
 391
 392 int hfsplus_free_fork(struct super_block *sb, u32 cnid,
 393                 struct hfsplus_fork_raw *fork, int type)
 394 {
 395         struct hfs_find_data fd;
 396         hfsplus_extent_rec ext_entry;
 397         u32 total_blocks, blocks, start;
 398         int res, i;
 399
 400         total_blocks = be32_to_cpu(fork->total_blocks);
 401         if (!total_blocks)
 402                 return 0;
 403
 404         blocks = 0;
 405         for (i = 0; i < 8; i++)
 406                 blocks += be32_to_cpu(fork->extents[i].block_count);
 407
 408         res = hfsplus_free_extents(sb, fork->extents, blocks, blocks);
 409         if (res)
 410                 return res;
 411         if (total_blocks == blocks)
 412                 return 0;
 413
 414         res = hfs_find_init(HFSPLUS_SB(sb)->ext_tree, &fd);
 415         if (res)
 416                 return res;
 417         do {
 418                 res = __hfsplus_ext_read_extent(&fd, ext_entry, cnid,
 419                                                 total_blocks, type);
 420                 if (res)
 421                         break;
 422                 start = be32_to_cpu(fd.key->ext.start_block);
 423                 hfsplus_free_extents(sb, ext_entry,
 424                                      total_blocks - start,
 425                                      total_blocks);
 426                 hfs_brec_remove(&fd);
 427                 total_blocks = start;
 428         } while (total_blocks > blocks);
 429         hfs_find_exit(&fd);
 430
 431         return res;
 432 }
 433
 434 int hfsplus_file_extend(struct inode *inode, bool zeroout)
 435 {
 436         struct super_block *sb = inode->i_sb;
 437         struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb);
 438         struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
 439         u32 start, len, goal;
 440         int res;
 441
 442         if (sbi->alloc_file->i_size * 8 <
 443             sbi->total_blocks - sbi->free_blocks + 8) {
 444                 /* extend alloc file */
 445                 pr_err("extend alloc file! (%llu,%u,%u)\n",
 446                        sbi->alloc_file->i_size * 8,
 447                        sbi->total_blocks, sbi->free_blocks);
 448                 return -ENOSPC;
 449         }
 450
 451         mutex_lock(&hip->extents_lock);
 452         if (hip->alloc_blocks == hip->first_blocks)
 453                 goal = hfsplus_ext_lastblock(hip->first_extents);
 454         else {
 455                 res = hfsplus_ext_read_extent(inode, hip->alloc_blocks);
 456                 if (res)
 457                         goto out;
 458                 goal = hfsplus_ext_lastblock(hip->cached_extents);
 459         }
 460
 461         len = hip->clump_blocks;
 462         start = hfsplus_block_allocate(sb, sbi->total_blocks, goal, &len);
 463         if (start >= sbi->total_blocks) {
 464                 start = hfsplus_block_allocate(sb, goal, 0, &len);
 465                 if (start >= goal) {
 466                         res = -ENOSPC;
 467                         goto out;
 468                 }
 469         }
 470
 471         if (zeroout) {
 472                 res = sb_issue_zeroout(sb, start, len, GFP_NOFS);
 473                 if (res)
 474                         goto out;
 475         }
 476
 477         hfs_dbg(EXTENT, "extend %lu: %u,%u\n", inode->i_ino, start, len);
 478
 479         if (hip->alloc_blocks <= hip->first_blocks) {
 480                 if (!hip->first_blocks) {
 481                         hfs_dbg(EXTENT, "first extents\n");
 482                         /* no extents yet */
 483                         hip->first_extents[0].start_block = cpu_to_be32(start);
 484                         hip->first_extents[0].block_count = cpu_to_be32(len);
 485                         res = 0;
 486                 } else {
 487                         /* try to append to extents in inode */
 488                         res = hfsplus_add_extent(hip->first_extents,
 489                                                  hip->alloc_blocks,
 490                                                  start, len);
 491                         if (res == -ENOSPC)
 492                                 goto insert_extent;
 493                 }
 494                 if (!res) {
 495                         hfsplus_dump_extent(hip->first_extents);
 496                         hip->first_blocks += len;
 497                 }
 498         } else {
 499                 res = hfsplus_add_extent(hip->cached_extents,
 500                                          hip->alloc_blocks - hip->cached_start,
 501                                          start, len);
 502                 if (!res) {
 503                         hfsplus_dump_extent(hip->cached_extents);
 504                         hip->extent_state |= HFSPLUS_EXT_DIRTY;
 505                         hip->cached_blocks += len;
 506                 } else if (res == -ENOSPC)
 507                         goto insert_extent;
 508         }
 509 out:
 510         if (!res) {
 511                 hip->alloc_blocks += len;
 512                 mutex_unlock(&hip->extents_lock);
 513                 hfsplus_mark_inode_dirty(inode, HFSPLUS_I_ALLOC_DIRTY);
 514                 return 0;
 515         }
 516         mutex_unlock(&hip->extents_lock);
 517         return res;
 518
 519 insert_extent:
 520         hfs_dbg(EXTENT, "insert new extent\n");
 521         res = hfsplus_ext_write_extent_locked(inode);
 522         if (res)
 523                 goto out;
 524
 525         memset(hip->cached_extents, 0, sizeof(hfsplus_extent_rec));
 526         hip->cached_extents[0].start_block = cpu_to_be32(start);
 527         hip->cached_extents[0].block_count = cpu_to_be32(len);
 528         hfsplus_dump_extent(hip->cached_extents);
 529         hip->extent_state |= HFSPLUS_EXT_DIRTY | HFSPLUS_EXT_NEW;
 530         hip->cached_start = hip->alloc_blocks;
 531         hip->cached_blocks = len;
 532
 533         res = 0;
 534         goto out;
 535 }
 536
 537 void hfsplus_file_truncate(struct inode *inode)
 538 {
 539         struct super_block *sb = inode->i_sb;
 540         struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
 541         struct hfs_find_data fd;
 542         u32 alloc_cnt, blk_cnt, start;
 543         int res;
 544
 545         hfs_dbg(INODE, "truncate: %lu, %llu -> %llu\n",
 546                 inode->i_ino, (long long)hip->phys_size, inode->i_size);
 547
 548         if (inode->i_size > hip->phys_size) {
 549                 struct address_space *mapping = inode->i_mapping;
 550                 struct page *page;
 551                 void *fsdata;
 552                 loff_t size = inode->i_size;
 553
 554                 res = pagecache_write_begin(NULL, mapping, size, 0,
 555                                                 AOP_FLAG_UNINTERRUPTIBLE,
 556                                                 &page, &fsdata);
 557                 if (res)
 558                         return;
 559                 res = pagecache_write_end(NULL, mapping, size,
 560                         0, 0, page, fsdata);
 561                 if (res < 0)
 562                         return;
 563                 mark_inode_dirty(inode);
 564                 return;
 565         } else if (inode->i_size == hip->phys_size)
 566                 return;
 567
 568         blk_cnt = (inode->i_size + HFSPLUS_SB(sb)->alloc_blksz - 1) >>
 569                         HFSPLUS_SB(sb)->alloc_blksz_shift;
 570
 571         mutex_lock(&hip->extents_lock);
 572
 573         alloc_cnt = hip->alloc_blocks;
 574         if (blk_cnt == alloc_cnt)
 575                 goto out_unlock;
 576
 577         res = hfs_find_init(HFSPLUS_SB(sb)->ext_tree, &fd);
 578         if (res) {
 579                 mutex_unlock(&hip->extents_lock);
 580                 /* XXX: We lack error handling of hfsplus_file_truncate() */
 581                 return;
 582         }
 583         while (1) {
 584                 if (alloc_cnt == hip->first_blocks) {
 585                         hfsplus_free_extents(sb, hip->first_extents,
 586                                              alloc_cnt, alloc_cnt - blk_cnt);
 587                         hfsplus_dump_extent(hip->first_extents);
 588                         hip->first_blocks = blk_cnt;
 589                         break;
 590                 }
 591                 res = __hfsplus_ext_cache_extent(&fd, inode, alloc_cnt);
 592                 if (res)
 593                         break;
 594                 start = hip->cached_start;
 595                 hfsplus_free_extents(sb, hip->cached_extents,
 596                                      alloc_cnt - start, alloc_cnt - blk_cnt);
 597                 hfsplus_dump_extent(hip->cached_extents);
 598                 if (blk_cnt > start) {
 599                         hip->extent_state |= HFSPLUS_EXT_DIRTY;
 600                         break;
 601                 }
 602                 alloc_cnt = start;
 603                 hip->cached_start = hip->cached_blocks = 0;
 604                 hip->extent_state &= ~(HFSPLUS_EXT_DIRTY | HFSPLUS_EXT_NEW);
 605                 hfs_brec_remove(&fd);
 606         }
 607         hfs_find_exit(&fd);
 608
 609         hip->alloc_blocks = blk_cnt;
 610 out_unlock:
 611         mutex_unlock(&hip->extents_lock);
 612         hip->phys_size = inode->i_size;
 613         hip->fs_blocks = (inode->i_size + sb->s_blocksize - 1) >>
 614                 sb->s_blocksize_bits;
 615         inode_set_bytes(inode, hip->fs_blocks << sb->s_blocksize_bits);
 616         hfsplus_mark_inode_dirty(inode, HFSPLUS_I_ALLOC_DIRTY);
 617 }