1 /* 2 * linux/fs/affs/file.c 3 * 4 * (c) 1996 Hans-Joachim Widmaier - Rewritten 5 * 6 * (C) 1993 Ray Burr - Modified for Amiga FFS filesystem. 7 * 8 * (C) 1992 Eric Youngdale Modified for ISO 9660 filesystem. 9 * 10 * (C) 1991 Linus Torvalds - minix filesystem 11 * 12 * affs regular file handling primitives 13 */ 14 15 #include "affs.h" 16 17 #if PAGE_SIZE < 4096 18 #error PAGE_SIZE must be at least 4096 19 #endif 20 21 static int affs_grow_extcache(struct inode *inode, u32 lc_idx); 22 static struct buffer_head *affs_alloc_extblock(struct inode *inode, struct buffer_head *bh, u32 ext); 23 static inline struct buffer_head *affs_get_extblock(struct inode *inode, u32 ext); 24 static struct buffer_head *affs_get_extblock_slow(struct inode *inode, u32 ext); 25 static int affs_file_open(struct inode *inode, struct file *filp); 26 static int affs_file_release(struct inode *inode, struct file *filp); 27 28 const struct file_operations affs_file_operations = { 29 .llseek = generic_file_llseek, 30 .read = do_sync_read, 31 .aio_read = generic_file_aio_read, 32 .write = do_sync_write, 33 .aio_write = generic_file_aio_write, 34 .mmap = generic_file_mmap, 35 .open = affs_file_open, 36 .release = affs_file_release, 37 .fsync = file_fsync, 38 .splice_read = generic_file_splice_read, 39 }; 40 41 const struct inode_operations affs_file_inode_operations = { 42 .truncate = affs_truncate, 43 .setattr = affs_notify_change, 44 }; 45 46 static int 47 affs_file_open(struct inode *inode, struct file *filp) 48 { 49 pr_debug("AFFS: open(%lu,%d)\n", 50 inode->i_ino, atomic_read(&AFFS_I(inode)->i_opencnt)); 51 atomic_inc(&AFFS_I(inode)->i_opencnt); 52 return 0; 53 } 54 55 static int 56 affs_file_release(struct inode *inode, struct file *filp) 57 { 58 pr_debug("AFFS: release(%lu, %d)\n", 59 inode->i_ino, atomic_read(&AFFS_I(inode)->i_opencnt)); 60 61 if (atomic_dec_and_test(&AFFS_I(inode)->i_opencnt)) { 62 mutex_lock(&inode->i_mutex); 63 if (inode->i_size != AFFS_I(inode)->mmu_private) 64 affs_truncate(inode); 65 affs_free_prealloc(inode); 66 mutex_unlock(&inode->i_mutex); 67 } 68 69 return 0; 70 } 71 72 static int 73 affs_grow_extcache(struct inode *inode, u32 lc_idx) 74 { 75 struct super_block *sb = inode->i_sb; 76 struct buffer_head *bh; 77 u32 lc_max; 78 int i, j, key; 79 80 if (!AFFS_I(inode)->i_lc) { 81 char *ptr = (char *)get_zeroed_page(GFP_NOFS); 82 if (!ptr) 83 return -ENOMEM; 84 AFFS_I(inode)->i_lc = (u32 *)ptr; 85 AFFS_I(inode)->i_ac = (struct affs_ext_key *)(ptr + AFFS_CACHE_SIZE / 2); 86 } 87 88 lc_max = AFFS_LC_SIZE << AFFS_I(inode)->i_lc_shift; 89 90 if (AFFS_I(inode)->i_extcnt > lc_max) { 91 u32 lc_shift, lc_mask, tmp, off; 92 93 /* need to recalculate linear cache, start from old size */ 94 lc_shift = AFFS_I(inode)->i_lc_shift; 95 tmp = (AFFS_I(inode)->i_extcnt / AFFS_LC_SIZE) >> lc_shift; 96 for (; tmp; tmp >>= 1) 97 lc_shift++; 98 lc_mask = (1 << lc_shift) - 1; 99 100 /* fix idx and old size to new shift */ 101 lc_idx >>= (lc_shift - AFFS_I(inode)->i_lc_shift); 102 AFFS_I(inode)->i_lc_size >>= (lc_shift - AFFS_I(inode)->i_lc_shift); 103 104 /* first shrink old cache to make more space */ 105 off = 1 << (lc_shift - AFFS_I(inode)->i_lc_shift); 106 for (i = 1, j = off; j < AFFS_LC_SIZE; i++, j += off) 107 AFFS_I(inode)->i_ac[i] = AFFS_I(inode)->i_ac[j]; 108 109 AFFS_I(inode)->i_lc_shift = lc_shift; 110 AFFS_I(inode)->i_lc_mask = lc_mask; 111 } 112 113 /* fill cache to the needed index */ 114 i = AFFS_I(inode)->i_lc_size; 115 AFFS_I(inode)->i_lc_size = lc_idx + 1; 116 for (; i <= lc_idx; i++) { 117 if (!i) { 118 AFFS_I(inode)->i_lc[0] = inode->i_ino; 119 continue; 120 } 121 key = AFFS_I(inode)->i_lc[i - 1]; 122 j = AFFS_I(inode)->i_lc_mask + 1; 123 // unlock cache 124 for (; j > 0; j--) { 125 bh = affs_bread(sb, key); 126 if (!bh) 127 goto err; 128 key = be32_to_cpu(AFFS_TAIL(sb, bh)->extension); 129 affs_brelse(bh); 130 } 131 // lock cache 132 AFFS_I(inode)->i_lc[i] = key; 133 } 134 135 return 0; 136 137 err: 138 // lock cache 139 return -EIO; 140 } 141 142 static struct buffer_head * 143 affs_alloc_extblock(struct inode *inode, struct buffer_head *bh, u32 ext) 144 { 145 struct super_block *sb = inode->i_sb; 146 struct buffer_head *new_bh; 147 u32 blocknr, tmp; 148 149 blocknr = affs_alloc_block(inode, bh->b_blocknr); 150 if (!blocknr) 151 return ERR_PTR(-ENOSPC); 152 153 new_bh = affs_getzeroblk(sb, blocknr); 154 if (!new_bh) { 155 affs_free_block(sb, blocknr); 156 return ERR_PTR(-EIO); 157 } 158 159 AFFS_HEAD(new_bh)->ptype = cpu_to_be32(T_LIST); 160 AFFS_HEAD(new_bh)->key = cpu_to_be32(blocknr); 161 AFFS_TAIL(sb, new_bh)->stype = cpu_to_be32(ST_FILE); 162 AFFS_TAIL(sb, new_bh)->parent = cpu_to_be32(inode->i_ino); 163 affs_fix_checksum(sb, new_bh); 164 165 mark_buffer_dirty_inode(new_bh, inode); 166 167 tmp = be32_to_cpu(AFFS_TAIL(sb, bh)->extension); 168 if (tmp) 169 affs_warning(sb, "alloc_ext", "previous extension set (%x)", tmp); 170 AFFS_TAIL(sb, bh)->extension = cpu_to_be32(blocknr); 171 affs_adjust_checksum(bh, blocknr - tmp); 172 mark_buffer_dirty_inode(bh, inode); 173 174 AFFS_I(inode)->i_extcnt++; 175 mark_inode_dirty(inode); 176 177 return new_bh; 178 } 179 180 static inline struct buffer_head * 181 affs_get_extblock(struct inode *inode, u32 ext) 182 { 183 /* inline the simplest case: same extended block as last time */ 184 struct buffer_head *bh = AFFS_I(inode)->i_ext_bh; 185 if (ext == AFFS_I(inode)->i_ext_last) 186 get_bh(bh); 187 else 188 /* we have to do more (not inlined) */ 189 bh = affs_get_extblock_slow(inode, ext); 190 191 return bh; 192 } 193 194 static struct buffer_head * 195 affs_get_extblock_slow(struct inode *inode, u32 ext) 196 { 197 struct super_block *sb = inode->i_sb; 198 struct buffer_head *bh; 199 u32 ext_key; 200 u32 lc_idx, lc_off, ac_idx; 201 u32 tmp, idx; 202 203 if (ext == AFFS_I(inode)->i_ext_last + 1) { 204 /* read the next extended block from the current one */ 205 bh = AFFS_I(inode)->i_ext_bh; 206 ext_key = be32_to_cpu(AFFS_TAIL(sb, bh)->extension); 207 if (ext < AFFS_I(inode)->i_extcnt) 208 goto read_ext; 209 if (ext > AFFS_I(inode)->i_extcnt) 210 BUG(); 211 bh = affs_alloc_extblock(inode, bh, ext); 212 if (IS_ERR(bh)) 213 return bh; 214 goto store_ext; 215 } 216 217 if (ext == 0) { 218 /* we seek back to the file header block */ 219 ext_key = inode->i_ino; 220 goto read_ext; 221 } 222 223 if (ext >= AFFS_I(inode)->i_extcnt) { 224 struct buffer_head *prev_bh; 225 226 /* allocate a new extended block */ 227 if (ext > AFFS_I(inode)->i_extcnt) 228 BUG(); 229 230 /* get previous extended block */ 231 prev_bh = affs_get_extblock(inode, ext - 1); 232 if (IS_ERR(prev_bh)) 233 return prev_bh; 234 bh = affs_alloc_extblock(inode, prev_bh, ext); 235 affs_brelse(prev_bh); 236 if (IS_ERR(bh)) 237 return bh; 238 goto store_ext; 239 } 240 241 again: 242 /* check if there is an extended cache and whether it's large enough */ 243 lc_idx = ext >> AFFS_I(inode)->i_lc_shift; 244 lc_off = ext & AFFS_I(inode)->i_lc_mask; 245 246 if (lc_idx >= AFFS_I(inode)->i_lc_size) { 247 int err; 248 249 err = affs_grow_extcache(inode, lc_idx); 250 if (err) 251 return ERR_PTR(err); 252 goto again; 253 } 254 255 /* every n'th key we find in the linear cache */ 256 if (!lc_off) { 257 ext_key = AFFS_I(inode)->i_lc[lc_idx]; 258 goto read_ext; 259 } 260 261 /* maybe it's still in the associative cache */ 262 ac_idx = (ext - lc_idx - 1) & AFFS_AC_MASK; 263 if (AFFS_I(inode)->i_ac[ac_idx].ext == ext) { 264 ext_key = AFFS_I(inode)->i_ac[ac_idx].key; 265 goto read_ext; 266 } 267 268 /* try to find one of the previous extended blocks */ 269 tmp = ext; 270 idx = ac_idx; 271 while (--tmp, --lc_off > 0) { 272 idx = (idx - 1) & AFFS_AC_MASK; 273 if (AFFS_I(inode)->i_ac[idx].ext == tmp) { 274 ext_key = AFFS_I(inode)->i_ac[idx].key; 275 goto find_ext; 276 } 277 } 278 279 /* fall back to the linear cache */ 280 ext_key = AFFS_I(inode)->i_lc[lc_idx]; 281 find_ext: 282 /* read all extended blocks until we find the one we need */ 283 //unlock cache 284 do { 285 bh = affs_bread(sb, ext_key); 286 if (!bh) 287 goto err_bread; 288 ext_key = be32_to_cpu(AFFS_TAIL(sb, bh)->extension); 289 affs_brelse(bh); 290 tmp++; 291 } while (tmp < ext); 292 //lock cache 293 294 /* store it in the associative cache */ 295 // recalculate ac_idx? 296 AFFS_I(inode)->i_ac[ac_idx].ext = ext; 297 AFFS_I(inode)->i_ac[ac_idx].key = ext_key; 298 299 read_ext: 300 /* finally read the right extended block */ 301 //unlock cache 302 bh = affs_bread(sb, ext_key); 303 if (!bh) 304 goto err_bread; 305 //lock cache 306 307 store_ext: 308 /* release old cached extended block and store the new one */ 309 affs_brelse(AFFS_I(inode)->i_ext_bh); 310 AFFS_I(inode)->i_ext_last = ext; 311 AFFS_I(inode)->i_ext_bh = bh; 312 get_bh(bh); 313 314 return bh; 315 316 err_bread: 317 affs_brelse(bh); 318 return ERR_PTR(-EIO); 319 } 320 321 static int 322 affs_get_block(struct inode *inode, sector_t block, struct buffer_head *bh_result, int create) 323 { 324 struct super_block *sb = inode->i_sb; 325 struct buffer_head *ext_bh; 326 u32 ext; 327 328 pr_debug("AFFS: get_block(%u, %lu)\n", (u32)inode->i_ino, (unsigned long)block); 329 330 BUG_ON(block > (sector_t)0x7fffffffUL); 331 332 if (block >= AFFS_I(inode)->i_blkcnt) { 333 if (block > AFFS_I(inode)->i_blkcnt || !create) 334 goto err_big; 335 } else 336 create = 0; 337 338 //lock cache 339 affs_lock_ext(inode); 340 341 ext = (u32)block / AFFS_SB(sb)->s_hashsize; 342 block -= ext * AFFS_SB(sb)->s_hashsize; 343 ext_bh = affs_get_extblock(inode, ext); 344 if (IS_ERR(ext_bh)) 345 goto err_ext; 346 map_bh(bh_result, sb, (sector_t)be32_to_cpu(AFFS_BLOCK(sb, ext_bh, block))); 347 348 if (create) { 349 u32 blocknr = affs_alloc_block(inode, ext_bh->b_blocknr); 350 if (!blocknr) 351 goto err_alloc; 352 set_buffer_new(bh_result); 353 AFFS_I(inode)->mmu_private += AFFS_SB(sb)->s_data_blksize; 354 AFFS_I(inode)->i_blkcnt++; 355 356 /* store new block */ 357 if (bh_result->b_blocknr) 358 affs_warning(sb, "get_block", "block already set (%x)", bh_result->b_blocknr); 359 AFFS_BLOCK(sb, ext_bh, block) = cpu_to_be32(blocknr); 360 AFFS_HEAD(ext_bh)->block_count = cpu_to_be32(block + 1); 361 affs_adjust_checksum(ext_bh, blocknr - bh_result->b_blocknr + 1); 362 bh_result->b_blocknr = blocknr; 363 364 if (!block) { 365 /* insert first block into header block */ 366 u32 tmp = be32_to_cpu(AFFS_HEAD(ext_bh)->first_data); 367 if (tmp) 368 affs_warning(sb, "get_block", "first block already set (%d)", tmp); 369 AFFS_HEAD(ext_bh)->first_data = cpu_to_be32(blocknr); 370 affs_adjust_checksum(ext_bh, blocknr - tmp); 371 } 372 } 373 374 affs_brelse(ext_bh); 375 //unlock cache 376 affs_unlock_ext(inode); 377 return 0; 378 379 err_big: 380 affs_error(inode->i_sb,"get_block","strange block request %d", block); 381 return -EIO; 382 err_ext: 383 // unlock cache 384 affs_unlock_ext(inode); 385 return PTR_ERR(ext_bh); 386 err_alloc: 387 brelse(ext_bh); 388 clear_buffer_mapped(bh_result); 389 bh_result->b_bdev = NULL; 390 // unlock cache 391 affs_unlock_ext(inode); 392 return -ENOSPC; 393 } 394 395 static int affs_writepage(struct page *page, struct writeback_control *wbc) 396 { 397 return block_write_full_page(page, affs_get_block, wbc); 398 } 399 400 static int affs_readpage(struct file *file, struct page *page) 401 { 402 return block_read_full_page(page, affs_get_block); 403 } 404 405 static int affs_write_begin(struct file *file, struct address_space *mapping, 406 loff_t pos, unsigned len, unsigned flags, 407 struct page **pagep, void **fsdata) 408 { 409 *pagep = NULL; 410 return cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata, 411 affs_get_block, 412 &AFFS_I(mapping->host)->mmu_private); 413 } 414 415 static sector_t _affs_bmap(struct address_space *mapping, sector_t block) 416 { 417 return generic_block_bmap(mapping,block,affs_get_block); 418 } 419 420 const struct address_space_operations affs_aops = { 421 .readpage = affs_readpage, 422 .writepage = affs_writepage, 423 .sync_page = block_sync_page, 424 .write_begin = affs_write_begin, 425 .write_end = generic_write_end, 426 .bmap = _affs_bmap 427 }; 428 429 static inline struct buffer_head * 430 affs_bread_ino(struct inode *inode, int block, int create) 431 { 432 struct buffer_head *bh, tmp_bh; 433 int err; 434 435 tmp_bh.b_state = 0; 436 err = affs_get_block(inode, block, &tmp_bh, create); 437 if (!err) { 438 bh = affs_bread(inode->i_sb, tmp_bh.b_blocknr); 439 if (bh) { 440 bh->b_state |= tmp_bh.b_state; 441 return bh; 442 } 443 err = -EIO; 444 } 445 return ERR_PTR(err); 446 } 447 448 static inline struct buffer_head * 449 affs_getzeroblk_ino(struct inode *inode, int block) 450 { 451 struct buffer_head *bh, tmp_bh; 452 int err; 453 454 tmp_bh.b_state = 0; 455 err = affs_get_block(inode, block, &tmp_bh, 1); 456 if (!err) { 457 bh = affs_getzeroblk(inode->i_sb, tmp_bh.b_blocknr); 458 if (bh) { 459 bh->b_state |= tmp_bh.b_state; 460 return bh; 461 } 462 err = -EIO; 463 } 464 return ERR_PTR(err); 465 } 466 467 static inline struct buffer_head * 468 affs_getemptyblk_ino(struct inode *inode, int block) 469 { 470 struct buffer_head *bh, tmp_bh; 471 int err; 472 473 tmp_bh.b_state = 0; 474 err = affs_get_block(inode, block, &tmp_bh, 1); 475 if (!err) { 476 bh = affs_getemptyblk(inode->i_sb, tmp_bh.b_blocknr); 477 if (bh) { 478 bh->b_state |= tmp_bh.b_state; 479 return bh; 480 } 481 err = -EIO; 482 } 483 return ERR_PTR(err); 484 } 485 486 static int 487 affs_do_readpage_ofs(struct file *file, struct page *page, unsigned from, unsigned to) 488 { 489 struct inode *inode = page->mapping->host; 490 struct super_block *sb = inode->i_sb; 491 struct buffer_head *bh; 492 char *data; 493 u32 bidx, boff, bsize; 494 u32 tmp; 495 496 pr_debug("AFFS: read_page(%u, %ld, %d, %d)\n", (u32)inode->i_ino, page->index, from, to); 497 BUG_ON(from > to || to > PAGE_CACHE_SIZE); 498 kmap(page); 499 data = page_address(page); 500 bsize = AFFS_SB(sb)->s_data_blksize; 501 tmp = (page->index << PAGE_CACHE_SHIFT) + from; 502 bidx = tmp / bsize; 503 boff = tmp % bsize; 504 505 while (from < to) { 506 bh = affs_bread_ino(inode, bidx, 0); 507 if (IS_ERR(bh)) 508 return PTR_ERR(bh); 509 tmp = min(bsize - boff, to - from); 510 BUG_ON(from + tmp > to || tmp > bsize); 511 memcpy(data + from, AFFS_DATA(bh) + boff, tmp); 512 affs_brelse(bh); 513 bidx++; 514 from += tmp; 515 boff = 0; 516 } 517 flush_dcache_page(page); 518 kunmap(page); 519 return 0; 520 } 521 522 static int 523 affs_extent_file_ofs(struct inode *inode, u32 newsize) 524 { 525 struct super_block *sb = inode->i_sb; 526 struct buffer_head *bh, *prev_bh; 527 u32 bidx, boff; 528 u32 size, bsize; 529 u32 tmp; 530 531 pr_debug("AFFS: extent_file(%u, %d)\n", (u32)inode->i_ino, newsize); 532 bsize = AFFS_SB(sb)->s_data_blksize; 533 bh = NULL; 534 size = AFFS_I(inode)->mmu_private; 535 bidx = size / bsize; 536 boff = size % bsize; 537 if (boff) { 538 bh = affs_bread_ino(inode, bidx, 0); 539 if (IS_ERR(bh)) 540 return PTR_ERR(bh); 541 tmp = min(bsize - boff, newsize - size); 542 BUG_ON(boff + tmp > bsize || tmp > bsize); 543 memset(AFFS_DATA(bh) + boff, 0, tmp); 544 be32_add_cpu(&AFFS_DATA_HEAD(bh)->size, tmp); 545 affs_fix_checksum(sb, bh); 546 mark_buffer_dirty_inode(bh, inode); 547 size += tmp; 548 bidx++; 549 } else if (bidx) { 550 bh = affs_bread_ino(inode, bidx - 1, 0); 551 if (IS_ERR(bh)) 552 return PTR_ERR(bh); 553 } 554 555 while (size < newsize) { 556 prev_bh = bh; 557 bh = affs_getzeroblk_ino(inode, bidx); 558 if (IS_ERR(bh)) 559 goto out; 560 tmp = min(bsize, newsize - size); 561 BUG_ON(tmp > bsize); 562 AFFS_DATA_HEAD(bh)->ptype = cpu_to_be32(T_DATA); 563 AFFS_DATA_HEAD(bh)->key = cpu_to_be32(inode->i_ino); 564 AFFS_DATA_HEAD(bh)->sequence = cpu_to_be32(bidx); 565 AFFS_DATA_HEAD(bh)->size = cpu_to_be32(tmp); 566 affs_fix_checksum(sb, bh); 567 bh->b_state &= ~(1UL << BH_New); 568 mark_buffer_dirty_inode(bh, inode); 569 if (prev_bh) { 570 u32 tmp = be32_to_cpu(AFFS_DATA_HEAD(prev_bh)->next); 571 if (tmp) 572 affs_warning(sb, "extent_file_ofs", "next block already set for %d (%d)", bidx, tmp); 573 AFFS_DATA_HEAD(prev_bh)->next = cpu_to_be32(bh->b_blocknr); 574 affs_adjust_checksum(prev_bh, bh->b_blocknr - tmp); 575 mark_buffer_dirty_inode(prev_bh, inode); 576 affs_brelse(prev_bh); 577 } 578 size += bsize; 579 bidx++; 580 } 581 affs_brelse(bh); 582 inode->i_size = AFFS_I(inode)->mmu_private = newsize; 583 return 0; 584 585 out: 586 inode->i_size = AFFS_I(inode)->mmu_private = newsize; 587 return PTR_ERR(bh); 588 } 589 590 static int 591 affs_readpage_ofs(struct file *file, struct page *page) 592 { 593 struct inode *inode = page->mapping->host; 594 u32 to; 595 int err; 596 597 pr_debug("AFFS: read_page(%u, %ld)\n", (u32)inode->i_ino, page->index); 598 to = PAGE_CACHE_SIZE; 599 if (((page->index + 1) << PAGE_CACHE_SHIFT) > inode->i_size) { 600 to = inode->i_size & ~PAGE_CACHE_MASK; 601 memset(page_address(page) + to, 0, PAGE_CACHE_SIZE - to); 602 } 603 604 err = affs_do_readpage_ofs(file, page, 0, to); 605 if (!err) 606 SetPageUptodate(page); 607 unlock_page(page); 608 return err; 609 } 610 611 static int affs_write_begin_ofs(struct file *file, struct address_space *mapping, 612 loff_t pos, unsigned len, unsigned flags, 613 struct page **pagep, void **fsdata) 614 { 615 struct inode *inode = mapping->host; 616 struct page *page; 617 pgoff_t index; 618 int err = 0; 619 620 pr_debug("AFFS: write_begin(%u, %llu, %llu)\n", (u32)inode->i_ino, (unsigned long long)pos, (unsigned long long)pos + len); 621 if (pos > AFFS_I(inode)->mmu_private) { 622 /* XXX: this probably leaves a too-big i_size in case of 623 * failure. Should really be updating i_size at write_end time 624 */ 625 err = affs_extent_file_ofs(inode, pos); 626 if (err) 627 return err; 628 } 629 630 index = pos >> PAGE_CACHE_SHIFT; 631 page = grab_cache_page_write_begin(mapping, index, flags); 632 if (!page) 633 return -ENOMEM; 634 *pagep = page; 635 636 if (PageUptodate(page)) 637 return 0; 638 639 /* XXX: inefficient but safe in the face of short writes */ 640 err = affs_do_readpage_ofs(file, page, 0, PAGE_CACHE_SIZE); 641 if (err) { 642 unlock_page(page); 643 page_cache_release(page); 644 } 645 return err; 646 } 647 648 static int affs_write_end_ofs(struct file *file, struct address_space *mapping, 649 loff_t pos, unsigned len, unsigned copied, 650 struct page *page, void *fsdata) 651 { 652 struct inode *inode = mapping->host; 653 struct super_block *sb = inode->i_sb; 654 struct buffer_head *bh, *prev_bh; 655 char *data; 656 u32 bidx, boff, bsize; 657 unsigned from, to; 658 u32 tmp; 659 int written; 660 661 from = pos & (PAGE_CACHE_SIZE - 1); 662 to = pos + len; 663 /* 664 * XXX: not sure if this can handle short copies (len < copied), but 665 * we don't have to, because the page should always be uptodate here, 666 * due to write_begin. 667 */ 668 669 pr_debug("AFFS: write_begin(%u, %llu, %llu)\n", (u32)inode->i_ino, (unsigned long long)pos, (unsigned long long)pos + len); 670 bsize = AFFS_SB(sb)->s_data_blksize; 671 data = page_address(page); 672 673 bh = NULL; 674 written = 0; 675 tmp = (page->index << PAGE_CACHE_SHIFT) + from; 676 bidx = tmp / bsize; 677 boff = tmp % bsize; 678 if (boff) { 679 bh = affs_bread_ino(inode, bidx, 0); 680 if (IS_ERR(bh)) 681 return PTR_ERR(bh); 682 tmp = min(bsize - boff, to - from); 683 BUG_ON(boff + tmp > bsize || tmp > bsize); 684 memcpy(AFFS_DATA(bh) + boff, data + from, tmp); 685 be32_add_cpu(&AFFS_DATA_HEAD(bh)->size, tmp); 686 affs_fix_checksum(sb, bh); 687 mark_buffer_dirty_inode(bh, inode); 688 written += tmp; 689 from += tmp; 690 bidx++; 691 } else if (bidx) { 692 bh = affs_bread_ino(inode, bidx - 1, 0); 693 if (IS_ERR(bh)) 694 return PTR_ERR(bh); 695 } 696 while (from + bsize <= to) { 697 prev_bh = bh; 698 bh = affs_getemptyblk_ino(inode, bidx); 699 if (IS_ERR(bh)) 700 goto out; 701 memcpy(AFFS_DATA(bh), data + from, bsize); 702 if (buffer_new(bh)) { 703 AFFS_DATA_HEAD(bh)->ptype = cpu_to_be32(T_DATA); 704 AFFS_DATA_HEAD(bh)->key = cpu_to_be32(inode->i_ino); 705 AFFS_DATA_HEAD(bh)->sequence = cpu_to_be32(bidx); 706 AFFS_DATA_HEAD(bh)->size = cpu_to_be32(bsize); 707 AFFS_DATA_HEAD(bh)->next = 0; 708 bh->b_state &= ~(1UL << BH_New); 709 if (prev_bh) { 710 u32 tmp = be32_to_cpu(AFFS_DATA_HEAD(prev_bh)->next); 711 if (tmp) 712 affs_warning(sb, "commit_write_ofs", "next block already set for %d (%d)", bidx, tmp); 713 AFFS_DATA_HEAD(prev_bh)->next = cpu_to_be32(bh->b_blocknr); 714 affs_adjust_checksum(prev_bh, bh->b_blocknr - tmp); 715 mark_buffer_dirty_inode(prev_bh, inode); 716 } 717 } 718 affs_brelse(prev_bh); 719 affs_fix_checksum(sb, bh); 720 mark_buffer_dirty_inode(bh, inode); 721 written += bsize; 722 from += bsize; 723 bidx++; 724 } 725 if (from < to) { 726 prev_bh = bh; 727 bh = affs_bread_ino(inode, bidx, 1); 728 if (IS_ERR(bh)) 729 goto out; 730 tmp = min(bsize, to - from); 731 BUG_ON(tmp > bsize); 732 memcpy(AFFS_DATA(bh), data + from, tmp); 733 if (buffer_new(bh)) { 734 AFFS_DATA_HEAD(bh)->ptype = cpu_to_be32(T_DATA); 735 AFFS_DATA_HEAD(bh)->key = cpu_to_be32(inode->i_ino); 736 AFFS_DATA_HEAD(bh)->sequence = cpu_to_be32(bidx); 737 AFFS_DATA_HEAD(bh)->size = cpu_to_be32(tmp); 738 AFFS_DATA_HEAD(bh)->next = 0; 739 bh->b_state &= ~(1UL << BH_New); 740 if (prev_bh) { 741 u32 tmp = be32_to_cpu(AFFS_DATA_HEAD(prev_bh)->next); 742 if (tmp) 743 affs_warning(sb, "commit_write_ofs", "next block already set for %d (%d)", bidx, tmp); 744 AFFS_DATA_HEAD(prev_bh)->next = cpu_to_be32(bh->b_blocknr); 745 affs_adjust_checksum(prev_bh, bh->b_blocknr - tmp); 746 mark_buffer_dirty_inode(prev_bh, inode); 747 } 748 } else if (be32_to_cpu(AFFS_DATA_HEAD(bh)->size) < tmp) 749 AFFS_DATA_HEAD(bh)->size = cpu_to_be32(tmp); 750 affs_brelse(prev_bh); 751 affs_fix_checksum(sb, bh); 752 mark_buffer_dirty_inode(bh, inode); 753 written += tmp; 754 from += tmp; 755 bidx++; 756 } 757 SetPageUptodate(page); 758 759 done: 760 affs_brelse(bh); 761 tmp = (page->index << PAGE_CACHE_SHIFT) + from; 762 if (tmp > inode->i_size) 763 inode->i_size = AFFS_I(inode)->mmu_private = tmp; 764 765 unlock_page(page); 766 page_cache_release(page); 767 768 return written; 769 770 out: 771 bh = prev_bh; 772 if (!written) 773 written = PTR_ERR(bh); 774 goto done; 775 } 776 777 const struct address_space_operations affs_aops_ofs = { 778 .readpage = affs_readpage_ofs, 779 //.writepage = affs_writepage_ofs, 780 //.sync_page = affs_sync_page_ofs, 781 .write_begin = affs_write_begin_ofs, 782 .write_end = affs_write_end_ofs 783 }; 784 785 /* Free any preallocated blocks. */ 786 787 void 788 affs_free_prealloc(struct inode *inode) 789 { 790 struct super_block *sb = inode->i_sb; 791 792 pr_debug("AFFS: free_prealloc(ino=%lu)\n", inode->i_ino); 793 794 while (AFFS_I(inode)->i_pa_cnt) { 795 AFFS_I(inode)->i_pa_cnt--; 796 affs_free_block(sb, ++AFFS_I(inode)->i_lastalloc); 797 } 798 } 799 800 /* Truncate (or enlarge) a file to the requested size. */ 801 802 void 803 affs_truncate(struct inode *inode) 804 { 805 struct super_block *sb = inode->i_sb; 806 u32 ext, ext_key; 807 u32 last_blk, blkcnt, blk; 808 u32 size; 809 struct buffer_head *ext_bh; 810 int i; 811 812 pr_debug("AFFS: truncate(inode=%d, oldsize=%u, newsize=%u)\n", 813 (u32)inode->i_ino, (u32)AFFS_I(inode)->mmu_private, (u32)inode->i_size); 814 815 last_blk = 0; 816 ext = 0; 817 if (inode->i_size) { 818 last_blk = ((u32)inode->i_size - 1) / AFFS_SB(sb)->s_data_blksize; 819 ext = last_blk / AFFS_SB(sb)->s_hashsize; 820 } 821 822 if (inode->i_size > AFFS_I(inode)->mmu_private) { 823 struct address_space *mapping = inode->i_mapping; 824 struct page *page; 825 void *fsdata; 826 u32 size = inode->i_size; 827 int res; 828 829 res = mapping->a_ops->write_begin(NULL, mapping, size, 0, 0, &page, &fsdata); 830 if (!res) 831 res = mapping->a_ops->write_end(NULL, mapping, size, 0, 0, page, fsdata); 832 else 833 inode->i_size = AFFS_I(inode)->mmu_private; 834 mark_inode_dirty(inode); 835 return; 836 } else if (inode->i_size == AFFS_I(inode)->mmu_private) 837 return; 838 839 // lock cache 840 ext_bh = affs_get_extblock(inode, ext); 841 if (IS_ERR(ext_bh)) { 842 affs_warning(sb, "truncate", "unexpected read error for ext block %u (%d)", 843 ext, PTR_ERR(ext_bh)); 844 return; 845 } 846 if (AFFS_I(inode)->i_lc) { 847 /* clear linear cache */ 848 i = (ext + 1) >> AFFS_I(inode)->i_lc_shift; 849 if (AFFS_I(inode)->i_lc_size > i) { 850 AFFS_I(inode)->i_lc_size = i; 851 for (; i < AFFS_LC_SIZE; i++) 852 AFFS_I(inode)->i_lc[i] = 0; 853 } 854 /* clear associative cache */ 855 for (i = 0; i < AFFS_AC_SIZE; i++) 856 if (AFFS_I(inode)->i_ac[i].ext >= ext) 857 AFFS_I(inode)->i_ac[i].ext = 0; 858 } 859 ext_key = be32_to_cpu(AFFS_TAIL(sb, ext_bh)->extension); 860 861 blkcnt = AFFS_I(inode)->i_blkcnt; 862 i = 0; 863 blk = last_blk; 864 if (inode->i_size) { 865 i = last_blk % AFFS_SB(sb)->s_hashsize + 1; 866 blk++; 867 } else 868 AFFS_HEAD(ext_bh)->first_data = 0; 869 AFFS_HEAD(ext_bh)->block_count = cpu_to_be32(i); 870 size = AFFS_SB(sb)->s_hashsize; 871 if (size > blkcnt - blk + i) 872 size = blkcnt - blk + i; 873 for (; i < size; i++, blk++) { 874 affs_free_block(sb, be32_to_cpu(AFFS_BLOCK(sb, ext_bh, i))); 875 AFFS_BLOCK(sb, ext_bh, i) = 0; 876 } 877 AFFS_TAIL(sb, ext_bh)->extension = 0; 878 affs_fix_checksum(sb, ext_bh); 879 mark_buffer_dirty_inode(ext_bh, inode); 880 affs_brelse(ext_bh); 881 882 if (inode->i_size) { 883 AFFS_I(inode)->i_blkcnt = last_blk + 1; 884 AFFS_I(inode)->i_extcnt = ext + 1; 885 if (AFFS_SB(sb)->s_flags & SF_OFS) { 886 struct buffer_head *bh = affs_bread_ino(inode, last_blk, 0); 887 u32 tmp; 888 if (IS_ERR(ext_bh)) { 889 affs_warning(sb, "truncate", "unexpected read error for last block %u (%d)", 890 ext, PTR_ERR(ext_bh)); 891 return; 892 } 893 tmp = be32_to_cpu(AFFS_DATA_HEAD(bh)->next); 894 AFFS_DATA_HEAD(bh)->next = 0; 895 affs_adjust_checksum(bh, -tmp); 896 affs_brelse(bh); 897 } 898 } else { 899 AFFS_I(inode)->i_blkcnt = 0; 900 AFFS_I(inode)->i_extcnt = 1; 901 } 902 AFFS_I(inode)->mmu_private = inode->i_size; 903 // unlock cache 904 905 while (ext_key) { 906 ext_bh = affs_bread(sb, ext_key); 907 size = AFFS_SB(sb)->s_hashsize; 908 if (size > blkcnt - blk) 909 size = blkcnt - blk; 910 for (i = 0; i < size; i++, blk++) 911 affs_free_block(sb, be32_to_cpu(AFFS_BLOCK(sb, ext_bh, i))); 912 affs_free_block(sb, ext_key); 913 ext_key = be32_to_cpu(AFFS_TAIL(sb, ext_bh)->extension); 914 affs_brelse(ext_bh); 915 } 916 affs_free_prealloc(inode); 917 } 918