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