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