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