fs/hfsplus/extents.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  *  linux/fs/hfsplus/extents.c
   4  *
   5  * Copyright (C) 2001
   6  * Brad Boyer (flar@allandria.com)
   7  * (C) 2003 Ardis Technologies <roman@ardistech.com>
   8  *
   9  * Handling of Extents both in catalog and extents overflow trees
  10  */
  11
  12 #include <linux/errno.h>
  13 #include <linux/fs.h>
  14 #include <linux/pagemap.h>
  15
  16 #include "hfsplus_fs.h"
  17 #include "hfsplus_raw.h"
  18
  19 /* Compare two extents keys, returns 0 on same, pos/neg for difference */
  20 int hfsplus_ext_cmp_key(const hfsplus_btree_key *k1,
  21                         const hfsplus_btree_key *k2)
  22 {
  23         __be32 k1id, k2id;
  24         __be32 k1s, k2s;
  25
  26         k1id = k1->ext.cnid;
  27         k2id = k2->ext.cnid;
  28         if (k1id != k2id)
  29                 return be32_to_cpu(k1id) < be32_to_cpu(k2id) ? -1 : 1;
  30
  31         if (k1->ext.fork_type != k2->ext.fork_type)
  32                 return k1->ext.fork_type < k2->ext.fork_type ? -1 : 1;
  33
  34         k1s = k1->ext.start_block;
  35         k2s = k2->ext.start_block;
  36         if (k1s == k2s)
  37                 return 0;
  38         return be32_to_cpu(k1s) < be32_to_cpu(k2s) ? -1 : 1;
  39 }
  40
  41 static void hfsplus_ext_build_key(hfsplus_btree_key *key, u32 cnid,
  42                                   u32 block, u8 type)
  43 {
  44         key->key_len = cpu_to_be16(HFSPLUS_EXT_KEYLEN - 2);
  45         key->ext.cnid = cpu_to_be32(cnid);
  46         key->ext.start_block = cpu_to_be32(block);
  47         key->ext.fork_type = type;
  48         key->ext.pad = 0;
  49 }
  50
  51 static u32 hfsplus_ext_find_block(struct hfsplus_extent *ext, u32 off)
  52 {
  53         int i;
  54         u32 count;
  55
  56         for (i = 0; i < 8; ext++, i++) {
  57                 count = be32_to_cpu(ext->block_count);
  58                 if (off < count)
  59                         return be32_to_cpu(ext->start_block) + off;
  60                 off -= count;
  61         }
  62         /* panic? */
  63         return 0;
  64 }
  65
  66 static int hfsplus_ext_block_count(struct hfsplus_extent *ext)
  67 {
  68         int i;
  69         u32 count = 0;
  70
  71         for (i = 0; i < 8; ext++, i++)
  72                 count += be32_to_cpu(ext->block_count);
  73         return count;
  74 }
  75
  76 static u32 hfsplus_ext_lastblock(struct hfsplus_extent *ext)
  77 {
  78         int i;
  79
  80         ext += 7;
  81         for (i = 0; i < 7; ext--, i++)
  82                 if (ext->block_count)
  83                         break;
  84         return be32_to_cpu(ext->start_block) + be32_to_cpu(ext->block_count);
  85 }
  86
  87 static int __hfsplus_ext_write_extent(struct inode *inode,
  88                 struct hfs_find_data *fd)
  89 {
  90         struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
  91         int res;
  92
  93         WARN_ON(!mutex_is_locked(&hip->extents_lock));
  94
  95         hfsplus_ext_build_key(fd->search_key, inode->i_ino, hip->cached_start,
  96                               HFSPLUS_IS_RSRC(inode) ?
  97                                 HFSPLUS_TYPE_RSRC : HFSPLUS_TYPE_DATA);
  98
  99         res = hfs_brec_find(fd, hfs_find_rec_by_key);
 100         if (hip->extent_state & HFSPLUS_EXT_NEW) {
 101                 if (res != -ENOENT)
 102                         return res;
 103                 hfs_brec_insert(fd, hip->cached_extents,
 104                                 sizeof(hfsplus_extent_rec));
 105                 hip->extent_state &= ~(HFSPLUS_EXT_DIRTY | HFSPLUS_EXT_NEW);
 106         } else {
 107                 if (res)
 108                         return res;
 109                 hfs_bnode_write(fd->bnode, hip->cached_extents,
 110                                 fd->entryoffset, fd->entrylength);
 111                 hip->extent_state &= ~HFSPLUS_EXT_DIRTY;
 112         }
 113
 114         /*
 115          * We can't just use hfsplus_mark_inode_dirty here, because we
 116          * also get called from hfsplus_write_inode, which should not
 117          * redirty the inode.  Instead the callers have to be careful
 118          * to explicily mark the inode dirty, too.
 119          */
 120         set_bit(HFSPLUS_I_EXT_DIRTY, &hip->flags);
 121
 122         return 0;
 123 }
 124
 125 static int hfsplus_ext_write_extent_locked(struct inode *inode)
 126 {
 127         int res = 0;
 128
 129         if (HFSPLUS_I(inode)->extent_state & HFSPLUS_EXT_DIRTY) {
 130                 struct hfs_find_data fd;
 131
 132                 res = hfs_find_init(HFSPLUS_SB(inode->i_sb)->ext_tree, &fd);
 133                 if (res)
 134                         return res;
 135                 res = __hfsplus_ext_write_extent(inode, &fd);
 136                 hfs_find_exit(&fd);
 137         }
 138         return res;
 139 }
 140
 141 int hfsplus_ext_write_extent(struct inode *inode)
 142 {
 143         int res;
 144
 145         mutex_lock(&HFSPLUS_I(inode)->extents_lock);
 146         res = hfsplus_ext_write_extent_locked(inode);
 147         mutex_unlock(&HFSPLUS_I(inode)->extents_lock);
 148
 149         return res;
 150 }
 151
 152 static inline int __hfsplus_ext_read_extent(struct hfs_find_data *fd,
 153                                             struct hfsplus_extent *extent,
 154                                             u32 cnid, u32 block, u8 type)
 155 {
 156         int res;
 157
 158         hfsplus_ext_build_key(fd->search_key, cnid, block, type);
 159         fd->key->ext.cnid = 0;
 160         res = hfs_brec_find(fd, hfs_find_rec_by_key);
 161         if (res && res != -ENOENT)
 162                 return res;
 163         if (fd->key->ext.cnid != fd->search_key->ext.cnid ||
 164             fd->key->ext.fork_type != fd->search_key->ext.fork_type)
 165                 return -ENOENT;
 166         if (fd->entrylength != sizeof(hfsplus_extent_rec))
 167                 return -EIO;
 168         hfs_bnode_read(fd->bnode, extent, fd->entryoffset,
 169                 sizeof(hfsplus_extent_rec));
 170         return 0;
 171 }
 172
 173 static inline int __hfsplus_ext_cache_extent(struct hfs_find_data *fd,
 174                 struct inode *inode, u32 block)
 175 {
 176         struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
 177         int res;
 178
 179         WARN_ON(!mutex_is_locked(&hip->extents_lock));
 180
 181         if (hip->extent_state & HFSPLUS_EXT_DIRTY) {
 182                 res = __hfsplus_ext_write_extent(inode, fd);
 183                 if (res)
 184                         return res;
 185         }
 186
 187         res = __hfsplus_ext_read_extent(fd, hip->cached_extents, inode->i_ino,
 188                                         block, HFSPLUS_IS_RSRC(inode) ?
 189                                                 HFSPLUS_TYPE_RSRC :
 190                                                 HFSPLUS_TYPE_DATA);
 191         if (!res) {
 192                 hip->cached_start = be32_to_cpu(fd->key->ext.start_block);
 193                 hip->cached_blocks =
 194                         hfsplus_ext_block_count(hip->cached_extents);
 195         } else {
 196                 hip->cached_start = hip->cached_blocks = 0;
 197                 hip->extent_state &= ~(HFSPLUS_EXT_DIRTY | HFSPLUS_EXT_NEW);
 198         }
 199         return res;
 200 }
 201
 202 static int hfsplus_ext_read_extent(struct inode *inode, u32 block)
 203 {
 204         struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
 205         struct hfs_find_data fd;
 206         int res;
 207
 208         if (block >= hip->cached_start &&
 209             block < hip->cached_start + hip->cached_blocks)
 210                 return 0;
 211
 212         res = hfs_find_init(HFSPLUS_SB(inode->i_sb)->ext_tree, &fd);
 213         if (!res) {
 214                 res = __hfsplus_ext_cache_extent(&fd, inode, block);
 215                 hfs_find_exit(&fd);
 216         }
 217         return res;
 218 }
 219
 220 /* Get a block at iblock for inode, possibly allocating if create */
 221 int hfsplus_get_block(struct inode *inode, sector_t iblock,
 222                       struct buffer_head *bh_result, int create)
 223 {
 224         struct super_block *sb = inode->i_sb;
 225         struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb);
 226         struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
 227         int res = -EIO;
 228         u32 ablock, dblock, mask;
 229         sector_t sector;
 230         int was_dirty = 0;
 231
 232         /* Convert inode block to disk allocation block */
 233         ablock = iblock >> sbi->fs_shift;
 234
 235         if (iblock >= hip->fs_blocks) {
 236                 if (iblock > hip->fs_blocks || !create)
 237                         return -EIO;
 238                 if (ablock >= hip->alloc_blocks) {
 239                         res = hfsplus_file_extend(inode, false);
 240                         if (res)
 241                                 return res;
 242                 }
 243         } else
 244                 create = 0;
 245
 246         if (ablock < hip->first_blocks) {
 247                 dblock = hfsplus_ext_find_block(hip->first_extents, ablock);
 248                 goto done;
 249         }
 250
 251         if (inode->i_ino == HFSPLUS_EXT_CNID)
 252                 return -EIO;
 253
 254         mutex_lock(&hip->extents_lock);
 255
 256         /*
 257          * hfsplus_ext_read_extent will write out a cached extent into
 258          * the extents btree.  In that case we may have to mark the inode
 259          * dirty even for a pure read of an extent here.
 260          */
 261         was_dirty = (hip->extent_state & HFSPLUS_EXT_DIRTY);
 262         res = hfsplus_ext_read_extent(inode, ablock);
 263         if (res) {
 264                 mutex_unlock(&hip->extents_lock);
 265                 return -EIO;
 266         }
 267         dblock = hfsplus_ext_find_block(hip->cached_extents,
 268                                         ablock - hip->cached_start);
 269         mutex_unlock(&hip->extents_lock);
 270
 271 done:
 272         hfs_dbg(EXTENT, "get_block(%lu): %llu - %u\n",
 273                 inode->i_ino, (long long)iblock, dblock);
 274
 275         mask = (1 << sbi->fs_shift) - 1;
 276         sector = ((sector_t)dblock << sbi->fs_shift) +
 277                   sbi->blockoffset + (iblock & mask);
 278         map_bh(bh_result, sb, sector);
 279
 280         if (create) {
 281                 set_buffer_new(bh_result);
 282                 hip->phys_size += sb->s_blocksize;
 283                 hip->fs_blocks++;
 284                 inode_add_bytes(inode, sb->s_blocksize);
 285         }
 286         if (create || was_dirty)
 287                 mark_inode_dirty(inode);
 288         return 0;
 289 }
 290
 291 static void hfsplus_dump_extent(struct hfsplus_extent *extent)
 292 {
 293         int i;
 294
 295         hfs_dbg(EXTENT, "   ");
 296         for (i = 0; i < 8; i++)
 297                 hfs_dbg_cont(EXTENT, " %u:%u",
 298                              be32_to_cpu(extent[i].start_block),
 299                              be32_to_cpu(extent[i].block_count));
 300         hfs_dbg_cont(EXTENT, "\n");
 301 }
 302
 303 static int hfsplus_add_extent(struct hfsplus_extent *extent, u32 offset,
 304                               u32 alloc_block, u32 block_count)
 305 {
 306         u32 count, start;
 307         int i;
 308
 309         hfsplus_dump_extent(extent);
 310         for (i = 0; i < 8; extent++, i++) {
 311                 count = be32_to_cpu(extent->block_count);
 312                 if (offset == count) {
 313                         start = be32_to_cpu(extent->start_block);
 314                         if (alloc_block != start + count) {
 315                                 if (++i >= 8)
 316                                         return -ENOSPC;
 317                                 extent++;
 318                                 extent->start_block = cpu_to_be32(alloc_block);
 319                         } else
 320                                 block_count += count;
 321                         extent->block_count = cpu_to_be32(block_count);
 322                         return 0;
 323                 } else if (offset < count)
 324                         break;
 325                 offset -= count;
 326         }
 327         /* panic? */
 328         return -EIO;
 329 }
 330
 331 static int hfsplus_free_extents(struct super_block *sb,
 332                                 struct hfsplus_extent *extent,
 333                                 u32 offset, u32 block_nr)
 334 {
 335         u32 count, start;
 336         int i;
 337         int err = 0;
 338
 339         hfsplus_dump_extent(extent);
 340         for (i = 0; i < 8; extent++, i++) {
 341                 count = be32_to_cpu(extent->block_count);
 342                 if (offset == count)
 343                         goto found;
 344                 else if (offset < count)
 345                         break;
 346                 offset -= count;
 347         }
 348         /* panic? */
 349         return -EIO;
 350 found:
 351         for (;;) {
 352                 start = be32_to_cpu(extent->start_block);
 353                 if (count <= block_nr) {
 354                         err = hfsplus_block_free(sb, start, count);
 355                         if (err) {
 356                                 pr_err("can't free extent\n");
 357                                 hfs_dbg(EXTENT, " start: %u count: %u\n",
 358                                         start, count);
 359                         }
 360                         extent->block_count = 0;
 361                         extent->start_block = 0;
 362                         block_nr -= count;
 363                 } else {
 364                         count -= block_nr;
 365                         err = hfsplus_block_free(sb, start + count, block_nr);
 366                         if (err) {
 367                                 pr_err("can't free extent\n");
 368                                 hfs_dbg(EXTENT, " start: %u count: %u\n",
 369                                         start, count);
 370                         }
 371                         extent->block_count = cpu_to_be32(count);
 372                         block_nr = 0;
 373                 }
 374                 if (!block_nr || !i) {
 375                         /*
 376                          * Try to free all extents and
 377                          * return only last error
 378                          */
 379                         return err;
 380                 }
 381                 i--;
 382                 extent--;
 383                 count = be32_to_cpu(extent->block_count);
 384         }
 385 }
 386
 387 int hfsplus_free_fork(struct super_block *sb, u32 cnid,
 388                 struct hfsplus_fork_raw *fork, int type)
 389 {
 390         struct hfs_find_data fd;
 391         hfsplus_extent_rec ext_entry;
 392         u32 total_blocks, blocks, start;
 393         int res, i;
 394
 395         total_blocks = be32_to_cpu(fork->total_blocks);
 396         if (!total_blocks)
 397                 return 0;
 398
 399         blocks = 0;
 400         for (i = 0; i < 8; i++)
 401                 blocks += be32_to_cpu(fork->extents[i].block_count);
 402
 403         res = hfsplus_free_extents(sb, fork->extents, blocks, blocks);
 404         if (res)
 405                 return res;
 406         if (total_blocks == blocks)
 407                 return 0;
 408
 409         res = hfs_find_init(HFSPLUS_SB(sb)->ext_tree, &fd);
 410         if (res)
 411                 return res;
 412         do {
 413                 res = __hfsplus_ext_read_extent(&fd, ext_entry, cnid,
 414                                                 total_blocks, type);
 415                 if (res)
 416                         break;
 417                 start = be32_to_cpu(fd.key->ext.start_block);
 418                 hfsplus_free_extents(sb, ext_entry,
 419                                      total_blocks - start,
 420                                      total_blocks);
 421                 hfs_brec_remove(&fd);
 422                 total_blocks = start;
 423         } while (total_blocks > blocks);
 424         hfs_find_exit(&fd);
 425
 426         return res;
 427 }
 428
 429 int hfsplus_file_extend(struct inode *inode, bool zeroout)
 430 {
 431         struct super_block *sb = inode->i_sb;
 432         struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb);
 433         struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
 434         u32 start, len, goal;
 435         int res;
 436
 437         if (sbi->alloc_file->i_size * 8 <
 438             sbi->total_blocks - sbi->free_blocks + 8) {
 439                 /* extend alloc file */
 440                 pr_err("extend alloc file! (%llu,%u,%u)\n",
 441                        sbi->alloc_file->i_size * 8,
 442                        sbi->total_blocks, sbi->free_blocks);
 443                 return -ENOSPC;
 444         }
 445
 446         mutex_lock(&hip->extents_lock);
 447         if (hip->alloc_blocks == hip->first_blocks)
 448                 goal = hfsplus_ext_lastblock(hip->first_extents);
 449         else {
 450                 res = hfsplus_ext_read_extent(inode, hip->alloc_blocks);
 451                 if (res)
 452                         goto out;
 453                 goal = hfsplus_ext_lastblock(hip->cached_extents);
 454         }
 455
 456         len = hip->clump_blocks;
 457         start = hfsplus_block_allocate(sb, sbi->total_blocks, goal, &len);
 458         if (start >= sbi->total_blocks) {
 459                 start = hfsplus_block_allocate(sb, goal, 0, &len);
 460                 if (start >= goal) {
 461                         res = -ENOSPC;
 462                         goto out;
 463                 }
 464         }
 465
 466         if (zeroout) {
 467                 res = sb_issue_zeroout(sb, start, len, GFP_NOFS);
 468                 if (res)
 469                         goto out;
 470         }
 471
 472         hfs_dbg(EXTENT, "extend %lu: %u,%u\n", inode->i_ino, start, len);
 473
 474         if (hip->alloc_blocks <= hip->first_blocks) {
 475                 if (!hip->first_blocks) {
 476                         hfs_dbg(EXTENT, "first extents\n");
 477                         /* no extents yet */
 478                         hip->first_extents[0].start_block = cpu_to_be32(start);
 479                         hip->first_extents[0].block_count = cpu_to_be32(len);
 480                         res = 0;
 481                 } else {
 482                         /* try to append to extents in inode */
 483                         res = hfsplus_add_extent(hip->first_extents,
 484                                                  hip->alloc_blocks,
 485                                                  start, len);
 486                         if (res == -ENOSPC)
 487                                 goto insert_extent;
 488                 }
 489                 if (!res) {
 490                         hfsplus_dump_extent(hip->first_extents);
 491                         hip->first_blocks += len;
 492                 }
 493         } else {
 494                 res = hfsplus_add_extent(hip->cached_extents,
 495                                          hip->alloc_blocks - hip->cached_start,
 496                                          start, len);
 497                 if (!res) {
 498                         hfsplus_dump_extent(hip->cached_extents);
 499                         hip->extent_state |= HFSPLUS_EXT_DIRTY;
 500                         hip->cached_blocks += len;
 501                 } else if (res == -ENOSPC)
 502                         goto insert_extent;
 503         }
 504 out:
 505         if (!res) {
 506                 hip->alloc_blocks += len;
 507                 mutex_unlock(&hip->extents_lock);
 508                 hfsplus_mark_inode_dirty(inode, HFSPLUS_I_ALLOC_DIRTY);
 509                 return 0;
 510         }
 511         mutex_unlock(&hip->extents_lock);
 512         return res;
 513
 514 insert_extent:
 515         hfs_dbg(EXTENT, "insert new extent\n");
 516         res = hfsplus_ext_write_extent_locked(inode);
 517         if (res)
 518                 goto out;
 519
 520         memset(hip->cached_extents, 0, sizeof(hfsplus_extent_rec));
 521         hip->cached_extents[0].start_block = cpu_to_be32(start);
 522         hip->cached_extents[0].block_count = cpu_to_be32(len);
 523         hfsplus_dump_extent(hip->cached_extents);
 524         hip->extent_state |= HFSPLUS_EXT_DIRTY | HFSPLUS_EXT_NEW;
 525         hip->cached_start = hip->alloc_blocks;
 526         hip->cached_blocks = len;
 527
 528         res = 0;
 529         goto out;
 530 }
 531
 532 void hfsplus_file_truncate(struct inode *inode)
 533 {
 534         struct super_block *sb = inode->i_sb;
 535         struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
 536         struct hfs_find_data fd;
 537         u32 alloc_cnt, blk_cnt, start;
 538         int res;
 539
 540         hfs_dbg(INODE, "truncate: %lu, %llu -> %llu\n",
 541                 inode->i_ino, (long long)hip->phys_size, inode->i_size);
 542
 543         if (inode->i_size > hip->phys_size) {
 544                 struct address_space *mapping = inode->i_mapping;
 545                 struct page *page;
 546                 void *fsdata;
 547                 loff_t size = inode->i_size;
 548
 549                 res = pagecache_write_begin(NULL, mapping, size, 0, 0,
 550                                             &page, &fsdata);
 551                 if (res)
 552                         return;
 553                 res = pagecache_write_end(NULL, mapping, size,
 554                         0, 0, page, fsdata);
 555                 if (res < 0)
 556                         return;
 557                 mark_inode_dirty(inode);
 558                 return;
 559         } else if (inode->i_size == hip->phys_size)
 560                 return;
 561
 562         blk_cnt = (inode->i_size + HFSPLUS_SB(sb)->alloc_blksz - 1) >>
 563                         HFSPLUS_SB(sb)->alloc_blksz_shift;
 564
 565         mutex_lock(&hip->extents_lock);
 566
 567         alloc_cnt = hip->alloc_blocks;
 568         if (blk_cnt == alloc_cnt)
 569                 goto out_unlock;
 570
 571         res = hfs_find_init(HFSPLUS_SB(sb)->ext_tree, &fd);
 572         if (res) {
 573                 mutex_unlock(&hip->extents_lock);
 574                 /* XXX: We lack error handling of hfsplus_file_truncate() */
 575                 return;
 576         }
 577         while (1) {
 578                 if (alloc_cnt == hip->first_blocks) {
 579                         hfsplus_free_extents(sb, hip->first_extents,
 580                                              alloc_cnt, alloc_cnt - blk_cnt);
 581                         hfsplus_dump_extent(hip->first_extents);
 582                         hip->first_blocks = blk_cnt;
 583                         break;
 584                 }
 585                 res = __hfsplus_ext_cache_extent(&fd, inode, alloc_cnt);
 586                 if (res)
 587                         break;
 588                 start = hip->cached_start;
 589                 hfsplus_free_extents(sb, hip->cached_extents,
 590                                      alloc_cnt - start, alloc_cnt - blk_cnt);
 591                 hfsplus_dump_extent(hip->cached_extents);
 592                 if (blk_cnt > start) {
 593                         hip->extent_state |= HFSPLUS_EXT_DIRTY;
 594                         break;
 595                 }
 596                 alloc_cnt = start;
 597                 hip->cached_start = hip->cached_blocks = 0;
 598                 hip->extent_state &= ~(HFSPLUS_EXT_DIRTY | HFSPLUS_EXT_NEW);
 599                 hfs_brec_remove(&fd);
 600         }
 601         hfs_find_exit(&fd);
 602
 603         hip->alloc_blocks = blk_cnt;
 604 out_unlock:
 605         mutex_unlock(&hip->extents_lock);
 606         hip->phys_size = inode->i_size;
 607         hip->fs_blocks = (inode->i_size + sb->s_blocksize - 1) >>
 608                 sb->s_blocksize_bits;
 609         inode_set_bytes(inode, hip->fs_blocks << sb->s_blocksize_bits);
 610         hfsplus_mark_inode_dirty(inode, HFSPLUS_I_ALLOC_DIRTY);
 611 }