fs/affs/file.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  *  linux/fs/affs/file.c
   4  *
   5  *  (c) 1996  Hans-Joachim Widmaier - Rewritten
   6  *
   7  *  (C) 1993  Ray Burr - Modified for Amiga FFS filesystem.
   8  *
   9  *  (C) 1992  Eric Youngdale Modified for ISO 9660 filesystem.
  10  *
  11  *  (C) 1991  Linus Torvalds - minix filesystem
  12  *
  13  *  affs regular file handling primitives
  14  */
  15
  16 #include <linux/uio.h>
  17 #include <linux/blkdev.h>
  18 #include "affs.h"
  19
  20 static struct buffer_head *affs_get_extblock_slow(struct inode *inode, u32 ext);
  21
  22 static int
  23 affs_file_open(struct inode *inode, struct file *filp)
  24 {
  25         pr_debug("open(%lu,%d)\n",
  26                  inode->i_ino, atomic_read(&AFFS_I(inode)->i_opencnt));
  27         atomic_inc(&AFFS_I(inode)->i_opencnt);
  28         return 0;
  29 }
  30
  31 static int
  32 affs_file_release(struct inode *inode, struct file *filp)
  33 {
  34         pr_debug("release(%lu, %d)\n",
  35                  inode->i_ino, atomic_read(&AFFS_I(inode)->i_opencnt));
  36
  37         if (atomic_dec_and_test(&AFFS_I(inode)->i_opencnt)) {
  38                 inode_lock(inode);
  39                 if (inode->i_size != AFFS_I(inode)->mmu_private)
  40                         affs_truncate(inode);
  41                 affs_free_prealloc(inode);
  42                 inode_unlock(inode);
  43         }
  44
  45         return 0;
  46 }
  47
  48 static int
  49 affs_grow_extcache(struct inode *inode, u32 lc_idx)
  50 {
  51         struct super_block      *sb = inode->i_sb;
  52         struct buffer_head      *bh;
  53         u32 lc_max;
  54         int i, j, key;
  55
  56         if (!AFFS_I(inode)->i_lc) {
  57                 char *ptr = (char *)get_zeroed_page(GFP_NOFS);
  58                 if (!ptr)
  59                         return -ENOMEM;
  60                 AFFS_I(inode)->i_lc = (u32 *)ptr;
  61                 AFFS_I(inode)->i_ac = (struct affs_ext_key *)(ptr + AFFS_CACHE_SIZE / 2);
  62         }
  63
  64         lc_max = AFFS_LC_SIZE << AFFS_I(inode)->i_lc_shift;
  65
  66         if (AFFS_I(inode)->i_extcnt > lc_max) {
  67                 u32 lc_shift, lc_mask, tmp, off;
  68
  69                 /* need to recalculate linear cache, start from old size */
  70                 lc_shift = AFFS_I(inode)->i_lc_shift;
  71                 tmp = (AFFS_I(inode)->i_extcnt / AFFS_LC_SIZE) >> lc_shift;
  72                 for (; tmp; tmp >>= 1)
  73                         lc_shift++;
  74                 lc_mask = (1 << lc_shift) - 1;
  75
  76                 /* fix idx and old size to new shift */
  77                 lc_idx >>= (lc_shift - AFFS_I(inode)->i_lc_shift);
  78                 AFFS_I(inode)->i_lc_size >>= (lc_shift - AFFS_I(inode)->i_lc_shift);
  79
  80                 /* first shrink old cache to make more space */
  81                 off = 1 << (lc_shift - AFFS_I(inode)->i_lc_shift);
  82                 for (i = 1, j = off; j < AFFS_LC_SIZE; i++, j += off)
  83                         AFFS_I(inode)->i_ac[i] = AFFS_I(inode)->i_ac[j];
  84
  85                 AFFS_I(inode)->i_lc_shift = lc_shift;
  86                 AFFS_I(inode)->i_lc_mask = lc_mask;
  87         }
  88
  89         /* fill cache to the needed index */
  90         i = AFFS_I(inode)->i_lc_size;
  91         AFFS_I(inode)->i_lc_size = lc_idx + 1;
  92         for (; i <= lc_idx; i++) {
  93                 if (!i) {
  94                         AFFS_I(inode)->i_lc[0] = inode->i_ino;
  95                         continue;
  96                 }
  97                 key = AFFS_I(inode)->i_lc[i - 1];
  98                 j = AFFS_I(inode)->i_lc_mask + 1;
  99                 // unlock cache
 100                 for (; j > 0; j--) {
 101                         bh = affs_bread(sb, key);
 102                         if (!bh)
 103                                 goto err;
 104                         key = be32_to_cpu(AFFS_TAIL(sb, bh)->extension);
 105                         affs_brelse(bh);
 106                 }
 107                 // lock cache
 108                 AFFS_I(inode)->i_lc[i] = key;
 109         }
 110
 111         return 0;
 112
 113 err:
 114         // lock cache
 115         return -EIO;
 116 }
 117
 118 static struct buffer_head *
 119 affs_alloc_extblock(struct inode *inode, struct buffer_head *bh, u32 ext)
 120 {
 121         struct super_block *sb = inode->i_sb;
 122         struct buffer_head *new_bh;
 123         u32 blocknr, tmp;
 124
 125         blocknr = affs_alloc_block(inode, bh->b_blocknr);
 126         if (!blocknr)
 127                 return ERR_PTR(-ENOSPC);
 128
 129         new_bh = affs_getzeroblk(sb, blocknr);
 130         if (!new_bh) {
 131                 affs_free_block(sb, blocknr);
 132                 return ERR_PTR(-EIO);
 133         }
 134
 135         AFFS_HEAD(new_bh)->ptype = cpu_to_be32(T_LIST);
 136         AFFS_HEAD(new_bh)->key = cpu_to_be32(blocknr);
 137         AFFS_TAIL(sb, new_bh)->stype = cpu_to_be32(ST_FILE);
 138         AFFS_TAIL(sb, new_bh)->parent = cpu_to_be32(inode->i_ino);
 139         affs_fix_checksum(sb, new_bh);
 140
 141         mark_buffer_dirty_inode(new_bh, inode);
 142
 143         tmp = be32_to_cpu(AFFS_TAIL(sb, bh)->extension);
 144         if (tmp)
 145                 affs_warning(sb, "alloc_ext", "previous extension set (%x)", tmp);
 146         AFFS_TAIL(sb, bh)->extension = cpu_to_be32(blocknr);
 147         affs_adjust_checksum(bh, blocknr - tmp);
 148         mark_buffer_dirty_inode(bh, inode);
 149
 150         AFFS_I(inode)->i_extcnt++;
 151         mark_inode_dirty(inode);
 152
 153         return new_bh;
 154 }
 155
 156 static inline struct buffer_head *
 157 affs_get_extblock(struct inode *inode, u32 ext)
 158 {
 159         /* inline the simplest case: same extended block as last time */
 160         struct buffer_head *bh = AFFS_I(inode)->i_ext_bh;
 161         if (ext == AFFS_I(inode)->i_ext_last)
 162                 get_bh(bh);
 163         else
 164                 /* we have to do more (not inlined) */
 165                 bh = affs_get_extblock_slow(inode, ext);
 166
 167         return bh;
 168 }
 169
 170 static struct buffer_head *
 171 affs_get_extblock_slow(struct inode *inode, u32 ext)
 172 {
 173         struct super_block *sb = inode->i_sb;
 174         struct buffer_head *bh;
 175         u32 ext_key;
 176         u32 lc_idx, lc_off, ac_idx;
 177         u32 tmp, idx;
 178
 179         if (ext == AFFS_I(inode)->i_ext_last + 1) {
 180                 /* read the next extended block from the current one */
 181                 bh = AFFS_I(inode)->i_ext_bh;
 182                 ext_key = be32_to_cpu(AFFS_TAIL(sb, bh)->extension);
 183                 if (ext < AFFS_I(inode)->i_extcnt)
 184                         goto read_ext;
 185                 BUG_ON(ext > AFFS_I(inode)->i_extcnt);
 186                 bh = affs_alloc_extblock(inode, bh, ext);
 187                 if (IS_ERR(bh))
 188                         return bh;
 189                 goto store_ext;
 190         }
 191
 192         if (ext == 0) {
 193                 /* we seek back to the file header block */
 194                 ext_key = inode->i_ino;
 195                 goto read_ext;
 196         }
 197
 198         if (ext >= AFFS_I(inode)->i_extcnt) {
 199                 struct buffer_head *prev_bh;
 200
 201                 /* allocate a new extended block */
 202                 BUG_ON(ext > AFFS_I(inode)->i_extcnt);
 203
 204                 /* get previous extended block */
 205                 prev_bh = affs_get_extblock(inode, ext - 1);
 206                 if (IS_ERR(prev_bh))
 207                         return prev_bh;
 208                 bh = affs_alloc_extblock(inode, prev_bh, ext);
 209                 affs_brelse(prev_bh);
 210                 if (IS_ERR(bh))
 211                         return bh;
 212                 goto store_ext;
 213         }
 214
 215 again:
 216         /* check if there is an extended cache and whether it's large enough */
 217         lc_idx = ext >> AFFS_I(inode)->i_lc_shift;
 218         lc_off = ext & AFFS_I(inode)->i_lc_mask;
 219
 220         if (lc_idx >= AFFS_I(inode)->i_lc_size) {
 221                 int err;
 222
 223                 err = affs_grow_extcache(inode, lc_idx);
 224                 if (err)
 225                         return ERR_PTR(err);
 226                 goto again;
 227         }
 228
 229         /* every n'th key we find in the linear cache */
 230         if (!lc_off) {
 231                 ext_key = AFFS_I(inode)->i_lc[lc_idx];
 232                 goto read_ext;
 233         }
 234
 235         /* maybe it's still in the associative cache */
 236         ac_idx = (ext - lc_idx - 1) & AFFS_AC_MASK;
 237         if (AFFS_I(inode)->i_ac[ac_idx].ext == ext) {
 238                 ext_key = AFFS_I(inode)->i_ac[ac_idx].key;
 239                 goto read_ext;
 240         }
 241
 242         /* try to find one of the previous extended blocks */
 243         tmp = ext;
 244         idx = ac_idx;
 245         while (--tmp, --lc_off > 0) {
 246                 idx = (idx - 1) & AFFS_AC_MASK;
 247                 if (AFFS_I(inode)->i_ac[idx].ext == tmp) {
 248                         ext_key = AFFS_I(inode)->i_ac[idx].key;
 249                         goto find_ext;
 250                 }
 251         }
 252
 253         /* fall back to the linear cache */
 254         ext_key = AFFS_I(inode)->i_lc[lc_idx];
 255 find_ext:
 256         /* read all extended blocks until we find the one we need */
 257         //unlock cache
 258         do {
 259                 bh = affs_bread(sb, ext_key);
 260                 if (!bh)
 261                         goto err_bread;
 262                 ext_key = be32_to_cpu(AFFS_TAIL(sb, bh)->extension);
 263                 affs_brelse(bh);
 264                 tmp++;
 265         } while (tmp < ext);
 266         //lock cache
 267
 268         /* store it in the associative cache */
 269         // recalculate ac_idx?
 270         AFFS_I(inode)->i_ac[ac_idx].ext = ext;
 271         AFFS_I(inode)->i_ac[ac_idx].key = ext_key;
 272
 273 read_ext:
 274         /* finally read the right extended block */
 275         //unlock cache
 276         bh = affs_bread(sb, ext_key);
 277         if (!bh)
 278                 goto err_bread;
 279         //lock cache
 280
 281 store_ext:
 282         /* release old cached extended block and store the new one */
 283         affs_brelse(AFFS_I(inode)->i_ext_bh);
 284         AFFS_I(inode)->i_ext_last = ext;
 285         AFFS_I(inode)->i_ext_bh = bh;
 286         get_bh(bh);
 287
 288         return bh;
 289
 290 err_bread:
 291         affs_brelse(bh);
 292         return ERR_PTR(-EIO);
 293 }
 294
 295 static int
 296 affs_get_block(struct inode *inode, sector_t block, struct buffer_head *bh_result, int create)
 297 {
 298         struct super_block      *sb = inode->i_sb;
 299         struct buffer_head      *ext_bh;
 300         u32                      ext;
 301
 302         pr_debug("%s(%lu, %llu)\n", __func__, inode->i_ino,
 303                  (unsigned long long)block);
 304
 305         BUG_ON(block > (sector_t)0x7fffffffUL);
 306
 307         if (block >= AFFS_I(inode)->i_blkcnt) {
 308                 if (block > AFFS_I(inode)->i_blkcnt || !create)
 309                         goto err_big;
 310         } else
 311                 create = 0;
 312
 313         //lock cache
 314         affs_lock_ext(inode);
 315
 316         ext = (u32)block / AFFS_SB(sb)->s_hashsize;
 317         block -= ext * AFFS_SB(sb)->s_hashsize;
 318         ext_bh = affs_get_extblock(inode, ext);
 319         if (IS_ERR(ext_bh))
 320                 goto err_ext;
 321         map_bh(bh_result, sb, (sector_t)be32_to_cpu(AFFS_BLOCK(sb, ext_bh, block)));
 322
 323         if (create) {
 324                 u32 blocknr = affs_alloc_block(inode, ext_bh->b_blocknr);
 325                 if (!blocknr)
 326                         goto err_alloc;
 327                 set_buffer_new(bh_result);
 328                 AFFS_I(inode)->mmu_private += AFFS_SB(sb)->s_data_blksize;
 329                 AFFS_I(inode)->i_blkcnt++;
 330
 331                 /* store new block */
 332                 if (bh_result->b_blocknr)
 333                         affs_warning(sb, "get_block",
 334                                      "block already set (%llx)",
 335                                      (unsigned long long)bh_result->b_blocknr);
 336                 AFFS_BLOCK(sb, ext_bh, block) = cpu_to_be32(blocknr);
 337                 AFFS_HEAD(ext_bh)->block_count = cpu_to_be32(block + 1);
 338                 affs_adjust_checksum(ext_bh, blocknr - bh_result->b_blocknr + 1);
 339                 bh_result->b_blocknr = blocknr;
 340
 341                 if (!block) {
 342                         /* insert first block into header block */
 343                         u32 tmp = be32_to_cpu(AFFS_HEAD(ext_bh)->first_data);
 344                         if (tmp)
 345                                 affs_warning(sb, "get_block", "first block already set (%d)", tmp);
 346                         AFFS_HEAD(ext_bh)->first_data = cpu_to_be32(blocknr);
 347                         affs_adjust_checksum(ext_bh, blocknr - tmp);
 348                 }
 349         }
 350
 351         affs_brelse(ext_bh);
 352         //unlock cache
 353         affs_unlock_ext(inode);
 354         return 0;
 355
 356 err_big:
 357         affs_error(inode->i_sb, "get_block", "strange block request %llu",
 358                    (unsigned long long)block);
 359         return -EIO;
 360 err_ext:
 361         // unlock cache
 362         affs_unlock_ext(inode);
 363         return PTR_ERR(ext_bh);
 364 err_alloc:
 365         brelse(ext_bh);
 366         clear_buffer_mapped(bh_result);
 367         bh_result->b_bdev = NULL;
 368         // unlock cache
 369         affs_unlock_ext(inode);
 370         return -ENOSPC;
 371 }
 372
 373 static int affs_writepage(struct page *page, struct writeback_control *wbc)
 374 {
 375         return block_write_full_page(page, affs_get_block, wbc);
 376 }
 377
 378 static int affs_readpage(struct file *file, struct page *page)
 379 {
 380         return block_read_full_page(page, affs_get_block);
 381 }
 382
 383 static void affs_write_failed(struct address_space *mapping, loff_t to)
 384 {
 385         struct inode *inode = mapping->host;
 386
 387         if (to > inode->i_size) {
 388                 truncate_pagecache(inode, inode->i_size);
 389                 affs_truncate(inode);
 390         }
 391 }
 392
 393 static ssize_t
 394 affs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
 395 {
 396         struct file *file = iocb->ki_filp;
 397         struct address_space *mapping = file->f_mapping;
 398         struct inode *inode = mapping->host;
 399         size_t count = iov_iter_count(iter);
 400         loff_t offset = iocb->ki_pos;
 401         ssize_t ret;
 402
 403         if (iov_iter_rw(iter) == WRITE) {
 404                 loff_t size = offset + count;
 405
 406                 if (AFFS_I(inode)->mmu_private < size)
 407                         return 0;
 408         }
 409
 410         ret = blockdev_direct_IO(iocb, inode, iter, affs_get_block);
 411         if (ret < 0 && iov_iter_rw(iter) == WRITE)
 412                 affs_write_failed(mapping, offset + count);
 413         return ret;
 414 }
 415
 416 static int affs_write_begin(struct file *file, struct address_space *mapping,
 417                         loff_t pos, unsigned len, unsigned flags,
 418                         struct page **pagep, void **fsdata)
 419 {
 420         int ret;
 421
 422         *pagep = NULL;
 423         ret = cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
 424                                 affs_get_block,
 425                                 &AFFS_I(mapping->host)->mmu_private);
 426         if (unlikely(ret))
 427                 affs_write_failed(mapping, pos + len);
 428
 429         return ret;
 430 }
 431
 432 static int affs_write_end(struct file *file, struct address_space *mapping,
 433                           loff_t pos, unsigned int len, unsigned int copied,
 434                           struct page *page, void *fsdata)
 435 {
 436         struct inode *inode = mapping->host;
 437         int ret;
 438
 439         ret = generic_write_end(file, mapping, pos, len, copied, page, fsdata);
 440
 441         /* Clear Archived bit on file writes, as AmigaOS would do */
 442         if (AFFS_I(inode)->i_protect & FIBF_ARCHIVED) {
 443                 AFFS_I(inode)->i_protect &= ~FIBF_ARCHIVED;
 444                 mark_inode_dirty(inode);
 445         }
 446
 447         return ret;
 448 }
 449
 450 static sector_t _affs_bmap(struct address_space *mapping, sector_t block)
 451 {
 452         return generic_block_bmap(mapping,block,affs_get_block);
 453 }
 454
 455 const struct address_space_operations affs_aops = {
 456         .readpage = affs_readpage,
 457         .writepage = affs_writepage,
 458         .write_begin = affs_write_begin,
 459         .write_end = affs_write_end,
 460         .direct_IO = affs_direct_IO,
 461         .bmap = _affs_bmap
 462 };
 463
 464 static inline struct buffer_head *
 465 affs_bread_ino(struct inode *inode, int block, int create)
 466 {
 467         struct buffer_head *bh, tmp_bh;
 468         int err;
 469
 470         tmp_bh.b_state = 0;
 471         err = affs_get_block(inode, block, &tmp_bh, create);
 472         if (!err) {
 473                 bh = affs_bread(inode->i_sb, tmp_bh.b_blocknr);
 474                 if (bh) {
 475                         bh->b_state |= tmp_bh.b_state;
 476                         return bh;
 477                 }
 478                 err = -EIO;
 479         }
 480         return ERR_PTR(err);
 481 }
 482
 483 static inline struct buffer_head *
 484 affs_getzeroblk_ino(struct inode *inode, int block)
 485 {
 486         struct buffer_head *bh, tmp_bh;
 487         int err;
 488
 489         tmp_bh.b_state = 0;
 490         err = affs_get_block(inode, block, &tmp_bh, 1);
 491         if (!err) {
 492                 bh = affs_getzeroblk(inode->i_sb, tmp_bh.b_blocknr);
 493                 if (bh) {
 494                         bh->b_state |= tmp_bh.b_state;
 495                         return bh;
 496                 }
 497                 err = -EIO;
 498         }
 499         return ERR_PTR(err);
 500 }
 501
 502 static inline struct buffer_head *
 503 affs_getemptyblk_ino(struct inode *inode, int block)
 504 {
 505         struct buffer_head *bh, tmp_bh;
 506         int err;
 507
 508         tmp_bh.b_state = 0;
 509         err = affs_get_block(inode, block, &tmp_bh, 1);
 510         if (!err) {
 511                 bh = affs_getemptyblk(inode->i_sb, tmp_bh.b_blocknr);
 512                 if (bh) {
 513                         bh->b_state |= tmp_bh.b_state;
 514                         return bh;
 515                 }
 516                 err = -EIO;
 517         }
 518         return ERR_PTR(err);
 519 }
 520
 521 static int
 522 affs_do_readpage_ofs(struct page *page, unsigned to, int create)
 523 {
 524         struct inode *inode = page->mapping->host;
 525         struct super_block *sb = inode->i_sb;
 526         struct buffer_head *bh;
 527         char *data;
 528         unsigned pos = 0;
 529         u32 bidx, boff, bsize;
 530         u32 tmp;
 531
 532         pr_debug("%s(%lu, %ld, 0, %d)\n", __func__, inode->i_ino,
 533                  page->index, to);
 534         BUG_ON(to > PAGE_SIZE);
 535         bsize = AFFS_SB(sb)->s_data_blksize;
 536         tmp = page->index << PAGE_SHIFT;
 537         bidx = tmp / bsize;
 538         boff = tmp % bsize;
 539
 540         while (pos < to) {
 541                 bh = affs_bread_ino(inode, bidx, create);
 542                 if (IS_ERR(bh))
 543                         return PTR_ERR(bh);
 544                 tmp = min(bsize - boff, to - pos);
 545                 BUG_ON(pos + tmp > to || tmp > bsize);
 546                 data = kmap_atomic(page);
 547                 memcpy(data + pos, AFFS_DATA(bh) + boff, tmp);
 548                 kunmap_atomic(data);
 549                 affs_brelse(bh);
 550                 bidx++;
 551                 pos += tmp;
 552                 boff = 0;
 553         }
 554         flush_dcache_page(page);
 555         return 0;
 556 }
 557
 558 static int
 559 affs_extent_file_ofs(struct inode *inode, u32 newsize)
 560 {
 561         struct super_block *sb = inode->i_sb;
 562         struct buffer_head *bh, *prev_bh;
 563         u32 bidx, boff;
 564         u32 size, bsize;
 565         u32 tmp;
 566
 567         pr_debug("%s(%lu, %d)\n", __func__, inode->i_ino, newsize);
 568         bsize = AFFS_SB(sb)->s_data_blksize;
 569         bh = NULL;
 570         size = AFFS_I(inode)->mmu_private;
 571         bidx = size / bsize;
 572         boff = size % bsize;
 573         if (boff) {
 574                 bh = affs_bread_ino(inode, bidx, 0);
 575                 if (IS_ERR(bh))
 576                         return PTR_ERR(bh);
 577                 tmp = min(bsize - boff, newsize - size);
 578                 BUG_ON(boff + tmp > bsize || tmp > bsize);
 579                 memset(AFFS_DATA(bh) + boff, 0, tmp);
 580                 be32_add_cpu(&AFFS_DATA_HEAD(bh)->size, tmp);
 581                 affs_fix_checksum(sb, bh);
 582                 mark_buffer_dirty_inode(bh, inode);
 583                 size += tmp;
 584                 bidx++;
 585         } else if (bidx) {
 586                 bh = affs_bread_ino(inode, bidx - 1, 0);
 587                 if (IS_ERR(bh))
 588                         return PTR_ERR(bh);
 589         }
 590
 591         while (size < newsize) {
 592                 prev_bh = bh;
 593                 bh = affs_getzeroblk_ino(inode, bidx);
 594                 if (IS_ERR(bh))
 595                         goto out;
 596                 tmp = min(bsize, newsize - size);
 597                 BUG_ON(tmp > bsize);
 598                 AFFS_DATA_HEAD(bh)->ptype = cpu_to_be32(T_DATA);
 599                 AFFS_DATA_HEAD(bh)->key = cpu_to_be32(inode->i_ino);
 600                 AFFS_DATA_HEAD(bh)->sequence = cpu_to_be32(bidx);
 601                 AFFS_DATA_HEAD(bh)->size = cpu_to_be32(tmp);
 602                 affs_fix_checksum(sb, bh);
 603                 bh->b_state &= ~(1UL << BH_New);
 604                 mark_buffer_dirty_inode(bh, inode);
 605                 if (prev_bh) {
 606                         u32 tmp_next = be32_to_cpu(AFFS_DATA_HEAD(prev_bh)->next);
 607
 608                         if (tmp_next)
 609                                 affs_warning(sb, "extent_file_ofs",
 610                                              "next block already set for %d (%d)",
 611                                              bidx, tmp_next);
 612                         AFFS_DATA_HEAD(prev_bh)->next = cpu_to_be32(bh->b_blocknr);
 613                         affs_adjust_checksum(prev_bh, bh->b_blocknr - tmp_next);
 614                         mark_buffer_dirty_inode(prev_bh, inode);
 615                         affs_brelse(prev_bh);
 616                 }
 617                 size += bsize;
 618                 bidx++;
 619         }
 620         affs_brelse(bh);
 621         inode->i_size = AFFS_I(inode)->mmu_private = newsize;
 622         return 0;
 623
 624 out:
 625         inode->i_size = AFFS_I(inode)->mmu_private = newsize;
 626         return PTR_ERR(bh);
 627 }
 628
 629 static int
 630 affs_readpage_ofs(struct file *file, struct page *page)
 631 {
 632         struct inode *inode = page->mapping->host;
 633         u32 to;
 634         int err;
 635
 636         pr_debug("%s(%lu, %ld)\n", __func__, inode->i_ino, page->index);
 637         to = PAGE_SIZE;
 638         if (((page->index + 1) << PAGE_SHIFT) > inode->i_size) {
 639                 to = inode->i_size & ~PAGE_MASK;
 640                 memset(page_address(page) + to, 0, PAGE_SIZE - to);
 641         }
 642
 643         err = affs_do_readpage_ofs(page, to, 0);
 644         if (!err)
 645                 SetPageUptodate(page);
 646         unlock_page(page);
 647         return err;
 648 }
 649
 650 static int affs_write_begin_ofs(struct file *file, struct address_space *mapping,
 651                                 loff_t pos, unsigned len, unsigned flags,
 652                                 struct page **pagep, void **fsdata)
 653 {
 654         struct inode *inode = mapping->host;
 655         struct page *page;
 656         pgoff_t index;
 657         int err = 0;
 658
 659         pr_debug("%s(%lu, %llu, %llu)\n", __func__, inode->i_ino, pos,
 660                  pos + len);
 661         if (pos > AFFS_I(inode)->mmu_private) {
 662                 /* XXX: this probably leaves a too-big i_size in case of
 663                  * failure. Should really be updating i_size at write_end time
 664                  */
 665                 err = affs_extent_file_ofs(inode, pos);
 666                 if (err)
 667                         return err;
 668         }
 669
 670         index = pos >> PAGE_SHIFT;
 671         page = grab_cache_page_write_begin(mapping, index, flags);
 672         if (!page)
 673                 return -ENOMEM;
 674         *pagep = page;
 675
 676         if (PageUptodate(page))
 677                 return 0;
 678
 679         /* XXX: inefficient but safe in the face of short writes */
 680         err = affs_do_readpage_ofs(page, PAGE_SIZE, 1);
 681         if (err) {
 682                 unlock_page(page);
 683                 put_page(page);
 684         }
 685         return err;
 686 }
 687
 688 static int affs_write_end_ofs(struct file *file, struct address_space *mapping,
 689                                 loff_t pos, unsigned len, unsigned copied,
 690                                 struct page *page, void *fsdata)
 691 {
 692         struct inode *inode = mapping->host;
 693         struct super_block *sb = inode->i_sb;
 694         struct buffer_head *bh, *prev_bh;
 695         char *data;
 696         u32 bidx, boff, bsize;
 697         unsigned from, to;
 698         u32 tmp;
 699         int written;
 700
 701         from = pos & (PAGE_SIZE - 1);
 702         to = from + len;
 703         /*
 704          * XXX: not sure if this can handle short copies (len < copied), but
 705          * we don't have to, because the page should always be uptodate here,
 706          * due to write_begin.
 707          */
 708
 709         pr_debug("%s(%lu, %llu, %llu)\n", __func__, inode->i_ino, pos,
 710                  pos + len);
 711         bsize = AFFS_SB(sb)->s_data_blksize;
 712         data = page_address(page);
 713
 714         bh = NULL;
 715         written = 0;
 716         tmp = (page->index << PAGE_SHIFT) + from;
 717         bidx = tmp / bsize;
 718         boff = tmp % bsize;
 719         if (boff) {
 720                 bh = affs_bread_ino(inode, bidx, 0);
 721                 if (IS_ERR(bh)) {
 722                         written = PTR_ERR(bh);
 723                         goto err_first_bh;
 724                 }
 725                 tmp = min(bsize - boff, to - from);
 726                 BUG_ON(boff + tmp > bsize || tmp > bsize);
 727                 memcpy(AFFS_DATA(bh) + boff, data + from, tmp);
 728                 be32_add_cpu(&AFFS_DATA_HEAD(bh)->size, tmp);
 729                 affs_fix_checksum(sb, bh);
 730                 mark_buffer_dirty_inode(bh, inode);
 731                 written += tmp;
 732                 from += tmp;
 733                 bidx++;
 734         } else if (bidx) {
 735                 bh = affs_bread_ino(inode, bidx - 1, 0);
 736                 if (IS_ERR(bh)) {
 737                         written = PTR_ERR(bh);
 738                         goto err_first_bh;
 739                 }
 740         }
 741         while (from + bsize <= to) {
 742                 prev_bh = bh;
 743                 bh = affs_getemptyblk_ino(inode, bidx);
 744                 if (IS_ERR(bh))
 745                         goto err_bh;
 746                 memcpy(AFFS_DATA(bh), data + from, bsize);
 747                 if (buffer_new(bh)) {
 748                         AFFS_DATA_HEAD(bh)->ptype = cpu_to_be32(T_DATA);
 749                         AFFS_DATA_HEAD(bh)->key = cpu_to_be32(inode->i_ino);
 750                         AFFS_DATA_HEAD(bh)->sequence = cpu_to_be32(bidx);
 751                         AFFS_DATA_HEAD(bh)->size = cpu_to_be32(bsize);
 752                         AFFS_DATA_HEAD(bh)->next = 0;
 753                         bh->b_state &= ~(1UL << BH_New);
 754                         if (prev_bh) {
 755                                 u32 tmp_next = be32_to_cpu(AFFS_DATA_HEAD(prev_bh)->next);
 756
 757                                 if (tmp_next)
 758                                         affs_warning(sb, "commit_write_ofs",
 759                                                      "next block already set for %d (%d)",
 760                                                      bidx, tmp_next);
 761                                 AFFS_DATA_HEAD(prev_bh)->next = cpu_to_be32(bh->b_blocknr);
 762                                 affs_adjust_checksum(prev_bh, bh->b_blocknr - tmp_next);
 763                                 mark_buffer_dirty_inode(prev_bh, inode);
 764                         }
 765                 }
 766                 affs_brelse(prev_bh);
 767                 affs_fix_checksum(sb, bh);
 768                 mark_buffer_dirty_inode(bh, inode);
 769                 written += bsize;
 770                 from += bsize;
 771                 bidx++;
 772         }
 773         if (from < to) {
 774                 prev_bh = bh;
 775                 bh = affs_bread_ino(inode, bidx, 1);
 776                 if (IS_ERR(bh))
 777                         goto err_bh;
 778                 tmp = min(bsize, to - from);
 779                 BUG_ON(tmp > bsize);
 780                 memcpy(AFFS_DATA(bh), data + from, tmp);
 781                 if (buffer_new(bh)) {
 782                         AFFS_DATA_HEAD(bh)->ptype = cpu_to_be32(T_DATA);
 783                         AFFS_DATA_HEAD(bh)->key = cpu_to_be32(inode->i_ino);
 784                         AFFS_DATA_HEAD(bh)->sequence = cpu_to_be32(bidx);
 785                         AFFS_DATA_HEAD(bh)->size = cpu_to_be32(tmp);
 786                         AFFS_DATA_HEAD(bh)->next = 0;
 787                         bh->b_state &= ~(1UL << BH_New);
 788                         if (prev_bh) {
 789                                 u32 tmp_next = be32_to_cpu(AFFS_DATA_HEAD(prev_bh)->next);
 790
 791                                 if (tmp_next)
 792                                         affs_warning(sb, "commit_write_ofs",
 793                                                      "next block already set for %d (%d)",
 794                                                      bidx, tmp_next);
 795                                 AFFS_DATA_HEAD(prev_bh)->next = cpu_to_be32(bh->b_blocknr);
 796                                 affs_adjust_checksum(prev_bh, bh->b_blocknr - tmp_next);
 797                                 mark_buffer_dirty_inode(prev_bh, inode);
 798                         }
 799                 } else if (be32_to_cpu(AFFS_DATA_HEAD(bh)->size) < tmp)
 800                         AFFS_DATA_HEAD(bh)->size = cpu_to_be32(tmp);
 801                 affs_brelse(prev_bh);
 802                 affs_fix_checksum(sb, bh);
 803                 mark_buffer_dirty_inode(bh, inode);
 804                 written += tmp;
 805                 from += tmp;
 806                 bidx++;
 807         }
 808         SetPageUptodate(page);
 809
 810 done:
 811         affs_brelse(bh);
 812         tmp = (page->index << PAGE_SHIFT) + from;
 813         if (tmp > inode->i_size)
 814                 inode->i_size = AFFS_I(inode)->mmu_private = tmp;
 815
 816         /* Clear Archived bit on file writes, as AmigaOS would do */
 817         if (AFFS_I(inode)->i_protect & FIBF_ARCHIVED) {
 818                 AFFS_I(inode)->i_protect &= ~FIBF_ARCHIVED;
 819                 mark_inode_dirty(inode);
 820         }
 821
 822 err_first_bh:
 823         unlock_page(page);
 824         put_page(page);
 825
 826         return written;
 827
 828 err_bh:
 829         bh = prev_bh;
 830         if (!written)
 831                 written = PTR_ERR(bh);
 832         goto done;
 833 }
 834
 835 const struct address_space_operations affs_aops_ofs = {
 836         .readpage = affs_readpage_ofs,
 837         //.writepage = affs_writepage_ofs,
 838         .write_begin = affs_write_begin_ofs,
 839         .write_end = affs_write_end_ofs
 840 };
 841
 842 /* Free any preallocated blocks. */
 843
 844 void
 845 affs_free_prealloc(struct inode *inode)
 846 {
 847         struct super_block *sb = inode->i_sb;
 848
 849         pr_debug("free_prealloc(ino=%lu)\n", inode->i_ino);
 850
 851         while (AFFS_I(inode)->i_pa_cnt) {
 852                 AFFS_I(inode)->i_pa_cnt--;
 853                 affs_free_block(sb, ++AFFS_I(inode)->i_lastalloc);
 854         }
 855 }
 856
 857 /* Truncate (or enlarge) a file to the requested size. */
 858
 859 void
 860 affs_truncate(struct inode *inode)
 861 {
 862         struct super_block *sb = inode->i_sb;
 863         u32 ext, ext_key;
 864         u32 last_blk, blkcnt, blk;
 865         u32 size;
 866         struct buffer_head *ext_bh;
 867         int i;
 868
 869         pr_debug("truncate(inode=%lu, oldsize=%llu, newsize=%llu)\n",
 870                  inode->i_ino, AFFS_I(inode)->mmu_private, inode->i_size);
 871
 872         last_blk = 0;
 873         ext = 0;
 874         if (inode->i_size) {
 875                 last_blk = ((u32)inode->i_size - 1) / AFFS_SB(sb)->s_data_blksize;
 876                 ext = last_blk / AFFS_SB(sb)->s_hashsize;
 877         }
 878
 879         if (inode->i_size > AFFS_I(inode)->mmu_private) {
 880                 struct address_space *mapping = inode->i_mapping;
 881                 struct page *page;
 882                 void *fsdata;
 883                 loff_t isize = inode->i_size;
 884                 int res;
 885
 886                 res = mapping->a_ops->write_begin(NULL, mapping, isize, 0, 0, &page, &fsdata);
 887                 if (!res)
 888                         res = mapping->a_ops->write_end(NULL, mapping, isize, 0, 0, page, fsdata);
 889                 else
 890                         inode->i_size = AFFS_I(inode)->mmu_private;
 891                 mark_inode_dirty(inode);
 892                 return;
 893         } else if (inode->i_size == AFFS_I(inode)->mmu_private)
 894                 return;
 895
 896         // lock cache
 897         ext_bh = affs_get_extblock(inode, ext);
 898         if (IS_ERR(ext_bh)) {
 899                 affs_warning(sb, "truncate",
 900                              "unexpected read error for ext block %u (%ld)",
 901                              ext, PTR_ERR(ext_bh));
 902                 return;
 903         }
 904         if (AFFS_I(inode)->i_lc) {
 905                 /* clear linear cache */
 906                 i = (ext + 1) >> AFFS_I(inode)->i_lc_shift;
 907                 if (AFFS_I(inode)->i_lc_size > i) {
 908                         AFFS_I(inode)->i_lc_size = i;
 909                         for (; i < AFFS_LC_SIZE; i++)
 910                                 AFFS_I(inode)->i_lc[i] = 0;
 911                 }
 912                 /* clear associative cache */
 913                 for (i = 0; i < AFFS_AC_SIZE; i++)
 914                         if (AFFS_I(inode)->i_ac[i].ext >= ext)
 915                                 AFFS_I(inode)->i_ac[i].ext = 0;
 916         }
 917         ext_key = be32_to_cpu(AFFS_TAIL(sb, ext_bh)->extension);
 918
 919         blkcnt = AFFS_I(inode)->i_blkcnt;
 920         i = 0;
 921         blk = last_blk;
 922         if (inode->i_size) {
 923                 i = last_blk % AFFS_SB(sb)->s_hashsize + 1;
 924                 blk++;
 925         } else
 926                 AFFS_HEAD(ext_bh)->first_data = 0;
 927         AFFS_HEAD(ext_bh)->block_count = cpu_to_be32(i);
 928         size = AFFS_SB(sb)->s_hashsize;
 929         if (size > blkcnt - blk + i)
 930                 size = blkcnt - blk + i;
 931         for (; i < size; i++, blk++) {
 932                 affs_free_block(sb, be32_to_cpu(AFFS_BLOCK(sb, ext_bh, i)));
 933                 AFFS_BLOCK(sb, ext_bh, i) = 0;
 934         }
 935         AFFS_TAIL(sb, ext_bh)->extension = 0;
 936         affs_fix_checksum(sb, ext_bh);
 937         mark_buffer_dirty_inode(ext_bh, inode);
 938         affs_brelse(ext_bh);
 939
 940         if (inode->i_size) {
 941                 AFFS_I(inode)->i_blkcnt = last_blk + 1;
 942                 AFFS_I(inode)->i_extcnt = ext + 1;
 943                 if (affs_test_opt(AFFS_SB(sb)->s_flags, SF_OFS)) {
 944                         struct buffer_head *bh = affs_bread_ino(inode, last_blk, 0);
 945                         u32 tmp;
 946                         if (IS_ERR(bh)) {
 947                                 affs_warning(sb, "truncate",
 948                                              "unexpected read error for last block %u (%ld)",
 949                                              ext, PTR_ERR(bh));
 950                                 return;
 951                         }
 952                         tmp = be32_to_cpu(AFFS_DATA_HEAD(bh)->next);
 953                         AFFS_DATA_HEAD(bh)->next = 0;
 954                         affs_adjust_checksum(bh, -tmp);
 955                         affs_brelse(bh);
 956                 }
 957         } else {
 958                 AFFS_I(inode)->i_blkcnt = 0;
 959                 AFFS_I(inode)->i_extcnt = 1;
 960         }
 961         AFFS_I(inode)->mmu_private = inode->i_size;
 962         // unlock cache
 963
 964         while (ext_key) {
 965                 ext_bh = affs_bread(sb, ext_key);
 966                 size = AFFS_SB(sb)->s_hashsize;
 967                 if (size > blkcnt - blk)
 968                         size = blkcnt - blk;
 969                 for (i = 0; i < size; i++, blk++)
 970                         affs_free_block(sb, be32_to_cpu(AFFS_BLOCK(sb, ext_bh, i)));
 971                 affs_free_block(sb, ext_key);
 972                 ext_key = be32_to_cpu(AFFS_TAIL(sb, ext_bh)->extension);
 973                 affs_brelse(ext_bh);
 974         }
 975         affs_free_prealloc(inode);
 976 }
 977
 978 int affs_file_fsync(struct file *filp, loff_t start, loff_t end, int datasync)
 979 {
 980         struct inode *inode = filp->f_mapping->host;
 981         int ret, err;
 982
 983         err = file_write_and_wait_range(filp, start, end);
 984         if (err)
 985                 return err;
 986
 987         inode_lock(inode);
 988         ret = write_inode_now(inode, 0);
 989         err = sync_blockdev(inode->i_sb->s_bdev);
 990         if (!ret)
 991                 ret = err;
 992         inode_unlock(inode);
 993         return ret;
 994 }
 995 const struct file_operations affs_file_operations = {
 996         .llseek         = generic_file_llseek,
 997         .read_iter      = generic_file_read_iter,
 998         .write_iter     = generic_file_write_iter,
 999         .mmap           = generic_file_mmap,
1000         .open           = affs_file_open,
1001         .release        = affs_file_release,
1002         .fsync          = affs_file_fsync,
1003         .splice_read    = generic_file_splice_read,
1004 };
1005
1006 const struct inode_operations affs_file_inode_operations = {
1007         .setattr        = affs_notify_change,
1008 };