1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * linux/fs/affs/file.c 4 * 5 * (c) 1996 Hans-Joachim Widmaier - Rewritten 6 * 7 * (C) 1993 Ray Burr - Modified for Amiga FFS filesystem. 8 * 9 * (C) 1992 Eric Youngdale Modified for ISO 9660 filesystem. 10 * 11 * (C) 1991 Linus Torvalds - minix filesystem 12 * 13 * affs regular file handling primitives 14 */ 15 16 #include <linux/uio.h> 17 #include <linux/blkdev.h> 18 #include "affs.h" 19 20 static struct buffer_head *affs_get_extblock_slow(struct inode *inode, u32 ext); 21 22 static int 23 affs_file_open(struct inode *inode, struct file *filp) 24 { 25 pr_debug("open(%lu,%d)\n", 26 inode->i_ino, atomic_read(&AFFS_I(inode)->i_opencnt)); 27 atomic_inc(&AFFS_I(inode)->i_opencnt); 28 return 0; 29 } 30 31 static int 32 affs_file_release(struct inode *inode, struct file *filp) 33 { 34 pr_debug("release(%lu, %d)\n", 35 inode->i_ino, atomic_read(&AFFS_I(inode)->i_opencnt)); 36 37 if (atomic_dec_and_test(&AFFS_I(inode)->i_opencnt)) { 38 inode_lock(inode); 39 if (inode->i_size != AFFS_I(inode)->mmu_private) 40 affs_truncate(inode); 41 affs_free_prealloc(inode); 42 inode_unlock(inode); 43 } 44 45 return 0; 46 } 47 48 static int 49 affs_grow_extcache(struct inode *inode, u32 lc_idx) 50 { 51 struct super_block *sb = inode->i_sb; 52 struct buffer_head *bh; 53 u32 lc_max; 54 int i, j, key; 55 56 if (!AFFS_I(inode)->i_lc) { 57 char *ptr = (char *)get_zeroed_page(GFP_NOFS); 58 if (!ptr) 59 return -ENOMEM; 60 AFFS_I(inode)->i_lc = (u32 *)ptr; 61 AFFS_I(inode)->i_ac = (struct affs_ext_key *)(ptr + AFFS_CACHE_SIZE / 2); 62 } 63 64 lc_max = AFFS_LC_SIZE << AFFS_I(inode)->i_lc_shift; 65 66 if (AFFS_I(inode)->i_extcnt > lc_max) { 67 u32 lc_shift, lc_mask, tmp, off; 68 69 /* need to recalculate linear cache, start from old size */ 70 lc_shift = AFFS_I(inode)->i_lc_shift; 71 tmp = (AFFS_I(inode)->i_extcnt / AFFS_LC_SIZE) >> lc_shift; 72 for (; tmp; tmp >>= 1) 73 lc_shift++; 74 lc_mask = (1 << lc_shift) - 1; 75 76 /* fix idx and old size to new shift */ 77 lc_idx >>= (lc_shift - AFFS_I(inode)->i_lc_shift); 78 AFFS_I(inode)->i_lc_size >>= (lc_shift - AFFS_I(inode)->i_lc_shift); 79 80 /* first shrink old cache to make more space */ 81 off = 1 << (lc_shift - AFFS_I(inode)->i_lc_shift); 82 for (i = 1, j = off; j < AFFS_LC_SIZE; i++, j += off) 83 AFFS_I(inode)->i_ac[i] = AFFS_I(inode)->i_ac[j]; 84 85 AFFS_I(inode)->i_lc_shift = lc_shift; 86 AFFS_I(inode)->i_lc_mask = lc_mask; 87 } 88 89 /* fill cache to the needed index */ 90 i = AFFS_I(inode)->i_lc_size; 91 AFFS_I(inode)->i_lc_size = lc_idx + 1; 92 for (; i <= lc_idx; i++) { 93 if (!i) { 94 AFFS_I(inode)->i_lc[0] = inode->i_ino; 95 continue; 96 } 97 key = AFFS_I(inode)->i_lc[i - 1]; 98 j = AFFS_I(inode)->i_lc_mask + 1; 99 // unlock cache 100 for (; j > 0; j--) { 101 bh = affs_bread(sb, key); 102 if (!bh) 103 goto err; 104 key = be32_to_cpu(AFFS_TAIL(sb, bh)->extension); 105 affs_brelse(bh); 106 } 107 // lock cache 108 AFFS_I(inode)->i_lc[i] = key; 109 } 110 111 return 0; 112 113 err: 114 // lock cache 115 return -EIO; 116 } 117 118 static struct buffer_head * 119 affs_alloc_extblock(struct inode *inode, struct buffer_head *bh, u32 ext) 120 { 121 struct super_block *sb = inode->i_sb; 122 struct buffer_head *new_bh; 123 u32 blocknr, tmp; 124 125 blocknr = affs_alloc_block(inode, bh->b_blocknr); 126 if (!blocknr) 127 return ERR_PTR(-ENOSPC); 128 129 new_bh = affs_getzeroblk(sb, blocknr); 130 if (!new_bh) { 131 affs_free_block(sb, blocknr); 132 return ERR_PTR(-EIO); 133 } 134 135 AFFS_HEAD(new_bh)->ptype = cpu_to_be32(T_LIST); 136 AFFS_HEAD(new_bh)->key = cpu_to_be32(blocknr); 137 AFFS_TAIL(sb, new_bh)->stype = cpu_to_be32(ST_FILE); 138 AFFS_TAIL(sb, new_bh)->parent = cpu_to_be32(inode->i_ino); 139 affs_fix_checksum(sb, new_bh); 140 141 mark_buffer_dirty_inode(new_bh, inode); 142 143 tmp = be32_to_cpu(AFFS_TAIL(sb, bh)->extension); 144 if (tmp) 145 affs_warning(sb, "alloc_ext", "previous extension set (%x)", tmp); 146 AFFS_TAIL(sb, bh)->extension = cpu_to_be32(blocknr); 147 affs_adjust_checksum(bh, blocknr - tmp); 148 mark_buffer_dirty_inode(bh, inode); 149 150 AFFS_I(inode)->i_extcnt++; 151 mark_inode_dirty(inode); 152 153 return new_bh; 154 } 155 156 static inline struct buffer_head * 157 affs_get_extblock(struct inode *inode, u32 ext) 158 { 159 /* inline the simplest case: same extended block as last time */ 160 struct buffer_head *bh = AFFS_I(inode)->i_ext_bh; 161 if (ext == AFFS_I(inode)->i_ext_last) 162 get_bh(bh); 163 else 164 /* we have to do more (not inlined) */ 165 bh = affs_get_extblock_slow(inode, ext); 166 167 return bh; 168 } 169 170 static struct buffer_head * 171 affs_get_extblock_slow(struct inode *inode, u32 ext) 172 { 173 struct super_block *sb = inode->i_sb; 174 struct buffer_head *bh; 175 u32 ext_key; 176 u32 lc_idx, lc_off, ac_idx; 177 u32 tmp, idx; 178 179 if (ext == AFFS_I(inode)->i_ext_last + 1) { 180 /* read the next extended block from the current one */ 181 bh = AFFS_I(inode)->i_ext_bh; 182 ext_key = be32_to_cpu(AFFS_TAIL(sb, bh)->extension); 183 if (ext < AFFS_I(inode)->i_extcnt) 184 goto read_ext; 185 BUG_ON(ext > AFFS_I(inode)->i_extcnt); 186 bh = affs_alloc_extblock(inode, bh, ext); 187 if (IS_ERR(bh)) 188 return bh; 189 goto store_ext; 190 } 191 192 if (ext == 0) { 193 /* we seek back to the file header block */ 194 ext_key = inode->i_ino; 195 goto read_ext; 196 } 197 198 if (ext >= AFFS_I(inode)->i_extcnt) { 199 struct buffer_head *prev_bh; 200 201 /* allocate a new extended block */ 202 BUG_ON(ext > AFFS_I(inode)->i_extcnt); 203 204 /* get previous extended block */ 205 prev_bh = affs_get_extblock(inode, ext - 1); 206 if (IS_ERR(prev_bh)) 207 return prev_bh; 208 bh = affs_alloc_extblock(inode, prev_bh, ext); 209 affs_brelse(prev_bh); 210 if (IS_ERR(bh)) 211 return bh; 212 goto store_ext; 213 } 214 215 again: 216 /* check if there is an extended cache and whether it's large enough */ 217 lc_idx = ext >> AFFS_I(inode)->i_lc_shift; 218 lc_off = ext & AFFS_I(inode)->i_lc_mask; 219 220 if (lc_idx >= AFFS_I(inode)->i_lc_size) { 221 int err; 222 223 err = affs_grow_extcache(inode, lc_idx); 224 if (err) 225 return ERR_PTR(err); 226 goto again; 227 } 228 229 /* every n'th key we find in the linear cache */ 230 if (!lc_off) { 231 ext_key = AFFS_I(inode)->i_lc[lc_idx]; 232 goto read_ext; 233 } 234 235 /* maybe it's still in the associative cache */ 236 ac_idx = (ext - lc_idx - 1) & AFFS_AC_MASK; 237 if (AFFS_I(inode)->i_ac[ac_idx].ext == ext) { 238 ext_key = AFFS_I(inode)->i_ac[ac_idx].key; 239 goto read_ext; 240 } 241 242 /* try to find one of the previous extended blocks */ 243 tmp = ext; 244 idx = ac_idx; 245 while (--tmp, --lc_off > 0) { 246 idx = (idx - 1) & AFFS_AC_MASK; 247 if (AFFS_I(inode)->i_ac[idx].ext == tmp) { 248 ext_key = AFFS_I(inode)->i_ac[idx].key; 249 goto find_ext; 250 } 251 } 252 253 /* fall back to the linear cache */ 254 ext_key = AFFS_I(inode)->i_lc[lc_idx]; 255 find_ext: 256 /* read all extended blocks until we find the one we need */ 257 //unlock cache 258 do { 259 bh = affs_bread(sb, ext_key); 260 if (!bh) 261 goto err_bread; 262 ext_key = be32_to_cpu(AFFS_TAIL(sb, bh)->extension); 263 affs_brelse(bh); 264 tmp++; 265 } while (tmp < ext); 266 //lock cache 267 268 /* store it in the associative cache */ 269 // recalculate ac_idx? 270 AFFS_I(inode)->i_ac[ac_idx].ext = ext; 271 AFFS_I(inode)->i_ac[ac_idx].key = ext_key; 272 273 read_ext: 274 /* finally read the right extended block */ 275 //unlock cache 276 bh = affs_bread(sb, ext_key); 277 if (!bh) 278 goto err_bread; 279 //lock cache 280 281 store_ext: 282 /* release old cached extended block and store the new one */ 283 affs_brelse(AFFS_I(inode)->i_ext_bh); 284 AFFS_I(inode)->i_ext_last = ext; 285 AFFS_I(inode)->i_ext_bh = bh; 286 get_bh(bh); 287 288 return bh; 289 290 err_bread: 291 affs_brelse(bh); 292 return ERR_PTR(-EIO); 293 } 294 295 static int 296 affs_get_block(struct inode *inode, sector_t block, struct buffer_head *bh_result, int create) 297 { 298 struct super_block *sb = inode->i_sb; 299 struct buffer_head *ext_bh; 300 u32 ext; 301 302 pr_debug("%s(%lu, %llu)\n", __func__, inode->i_ino, 303 (unsigned long long)block); 304 305 BUG_ON(block > (sector_t)0x7fffffffUL); 306 307 if (block >= AFFS_I(inode)->i_blkcnt) { 308 if (block > AFFS_I(inode)->i_blkcnt || !create) 309 goto err_big; 310 } else 311 create = 0; 312 313 //lock cache 314 affs_lock_ext(inode); 315 316 ext = (u32)block / AFFS_SB(sb)->s_hashsize; 317 block -= ext * AFFS_SB(sb)->s_hashsize; 318 ext_bh = affs_get_extblock(inode, ext); 319 if (IS_ERR(ext_bh)) 320 goto err_ext; 321 map_bh(bh_result, sb, (sector_t)be32_to_cpu(AFFS_BLOCK(sb, ext_bh, block))); 322 323 if (create) { 324 u32 blocknr = affs_alloc_block(inode, ext_bh->b_blocknr); 325 if (!blocknr) 326 goto err_alloc; 327 set_buffer_new(bh_result); 328 AFFS_I(inode)->mmu_private += AFFS_SB(sb)->s_data_blksize; 329 AFFS_I(inode)->i_blkcnt++; 330 331 /* store new block */ 332 if (bh_result->b_blocknr) 333 affs_warning(sb, "get_block", 334 "block already set (%llx)", 335 (unsigned long long)bh_result->b_blocknr); 336 AFFS_BLOCK(sb, ext_bh, block) = cpu_to_be32(blocknr); 337 AFFS_HEAD(ext_bh)->block_count = cpu_to_be32(block + 1); 338 affs_adjust_checksum(ext_bh, blocknr - bh_result->b_blocknr + 1); 339 bh_result->b_blocknr = blocknr; 340 341 if (!block) { 342 /* insert first block into header block */ 343 u32 tmp = be32_to_cpu(AFFS_HEAD(ext_bh)->first_data); 344 if (tmp) 345 affs_warning(sb, "get_block", "first block already set (%d)", tmp); 346 AFFS_HEAD(ext_bh)->first_data = cpu_to_be32(blocknr); 347 affs_adjust_checksum(ext_bh, blocknr - tmp); 348 } 349 } 350 351 affs_brelse(ext_bh); 352 //unlock cache 353 affs_unlock_ext(inode); 354 return 0; 355 356 err_big: 357 affs_error(inode->i_sb, "get_block", "strange block request %llu", 358 (unsigned long long)block); 359 return -EIO; 360 err_ext: 361 // unlock cache 362 affs_unlock_ext(inode); 363 return PTR_ERR(ext_bh); 364 err_alloc: 365 brelse(ext_bh); 366 clear_buffer_mapped(bh_result); 367 bh_result->b_bdev = NULL; 368 // unlock cache 369 affs_unlock_ext(inode); 370 return -ENOSPC; 371 } 372 373 static int affs_writepage(struct page *page, struct writeback_control *wbc) 374 { 375 return block_write_full_page(page, affs_get_block, wbc); 376 } 377 378 static int affs_read_folio(struct file *file, struct folio *folio) 379 { 380 return block_read_full_folio(folio, affs_get_block); 381 } 382 383 static void affs_write_failed(struct address_space *mapping, loff_t to) 384 { 385 struct inode *inode = mapping->host; 386 387 if (to > inode->i_size) { 388 truncate_pagecache(inode, inode->i_size); 389 affs_truncate(inode); 390 } 391 } 392 393 static ssize_t 394 affs_direct_IO(struct kiocb *iocb, struct iov_iter *iter) 395 { 396 struct file *file = iocb->ki_filp; 397 struct address_space *mapping = file->f_mapping; 398 struct inode *inode = mapping->host; 399 size_t count = iov_iter_count(iter); 400 loff_t offset = iocb->ki_pos; 401 ssize_t ret; 402 403 if (iov_iter_rw(iter) == WRITE) { 404 loff_t size = offset + count; 405 406 if (AFFS_I(inode)->mmu_private < size) 407 return 0; 408 } 409 410 ret = blockdev_direct_IO(iocb, inode, iter, affs_get_block); 411 if (ret < 0 && iov_iter_rw(iter) == WRITE) 412 affs_write_failed(mapping, offset + count); 413 return ret; 414 } 415 416 static int affs_write_begin(struct file *file, struct address_space *mapping, 417 loff_t pos, unsigned len, 418 struct page **pagep, void **fsdata) 419 { 420 int ret; 421 422 *pagep = NULL; 423 ret = cont_write_begin(file, mapping, pos, len, pagep, fsdata, 424 affs_get_block, 425 &AFFS_I(mapping->host)->mmu_private); 426 if (unlikely(ret)) 427 affs_write_failed(mapping, pos + len); 428 429 return ret; 430 } 431 432 static int affs_write_end(struct file *file, struct address_space *mapping, 433 loff_t pos, unsigned int len, unsigned int copied, 434 struct page *page, void *fsdata) 435 { 436 struct inode *inode = mapping->host; 437 int ret; 438 439 ret = generic_write_end(file, mapping, pos, len, copied, page, fsdata); 440 441 /* Clear Archived bit on file writes, as AmigaOS would do */ 442 if (AFFS_I(inode)->i_protect & FIBF_ARCHIVED) { 443 AFFS_I(inode)->i_protect &= ~FIBF_ARCHIVED; 444 mark_inode_dirty(inode); 445 } 446 447 return ret; 448 } 449 450 static sector_t _affs_bmap(struct address_space *mapping, sector_t block) 451 { 452 return generic_block_bmap(mapping,block,affs_get_block); 453 } 454 455 const struct address_space_operations affs_aops = { 456 .dirty_folio = block_dirty_folio, 457 .invalidate_folio = block_invalidate_folio, 458 .read_folio = affs_read_folio, 459 .writepage = affs_writepage, 460 .write_begin = affs_write_begin, 461 .write_end = affs_write_end, 462 .direct_IO = affs_direct_IO, 463 .bmap = _affs_bmap 464 }; 465 466 static inline struct buffer_head * 467 affs_bread_ino(struct inode *inode, int block, int create) 468 { 469 struct buffer_head *bh, tmp_bh; 470 int err; 471 472 tmp_bh.b_state = 0; 473 err = affs_get_block(inode, block, &tmp_bh, create); 474 if (!err) { 475 bh = affs_bread(inode->i_sb, tmp_bh.b_blocknr); 476 if (bh) { 477 bh->b_state |= tmp_bh.b_state; 478 return bh; 479 } 480 err = -EIO; 481 } 482 return ERR_PTR(err); 483 } 484 485 static inline struct buffer_head * 486 affs_getzeroblk_ino(struct inode *inode, int block) 487 { 488 struct buffer_head *bh, tmp_bh; 489 int err; 490 491 tmp_bh.b_state = 0; 492 err = affs_get_block(inode, block, &tmp_bh, 1); 493 if (!err) { 494 bh = affs_getzeroblk(inode->i_sb, tmp_bh.b_blocknr); 495 if (bh) { 496 bh->b_state |= tmp_bh.b_state; 497 return bh; 498 } 499 err = -EIO; 500 } 501 return ERR_PTR(err); 502 } 503 504 static inline struct buffer_head * 505 affs_getemptyblk_ino(struct inode *inode, int block) 506 { 507 struct buffer_head *bh, tmp_bh; 508 int err; 509 510 tmp_bh.b_state = 0; 511 err = affs_get_block(inode, block, &tmp_bh, 1); 512 if (!err) { 513 bh = affs_getemptyblk(inode->i_sb, tmp_bh.b_blocknr); 514 if (bh) { 515 bh->b_state |= tmp_bh.b_state; 516 return bh; 517 } 518 err = -EIO; 519 } 520 return ERR_PTR(err); 521 } 522 523 static int 524 affs_do_readpage_ofs(struct page *page, unsigned to, int create) 525 { 526 struct inode *inode = page->mapping->host; 527 struct super_block *sb = inode->i_sb; 528 struct buffer_head *bh; 529 unsigned pos = 0; 530 u32 bidx, boff, bsize; 531 u32 tmp; 532 533 pr_debug("%s(%lu, %ld, 0, %d)\n", __func__, inode->i_ino, 534 page->index, to); 535 BUG_ON(to > PAGE_SIZE); 536 bsize = AFFS_SB(sb)->s_data_blksize; 537 tmp = page->index << PAGE_SHIFT; 538 bidx = tmp / bsize; 539 boff = tmp % bsize; 540 541 while (pos < to) { 542 bh = affs_bread_ino(inode, bidx, create); 543 if (IS_ERR(bh)) 544 return PTR_ERR(bh); 545 tmp = min(bsize - boff, to - pos); 546 BUG_ON(pos + tmp > to || tmp > bsize); 547 memcpy_to_page(page, pos, AFFS_DATA(bh) + boff, tmp); 548 affs_brelse(bh); 549 bidx++; 550 pos += tmp; 551 boff = 0; 552 } 553 return 0; 554 } 555 556 static int 557 affs_extent_file_ofs(struct inode *inode, u32 newsize) 558 { 559 struct super_block *sb = inode->i_sb; 560 struct buffer_head *bh, *prev_bh; 561 u32 bidx, boff; 562 u32 size, bsize; 563 u32 tmp; 564 565 pr_debug("%s(%lu, %d)\n", __func__, inode->i_ino, newsize); 566 bsize = AFFS_SB(sb)->s_data_blksize; 567 bh = NULL; 568 size = AFFS_I(inode)->mmu_private; 569 bidx = size / bsize; 570 boff = size % bsize; 571 if (boff) { 572 bh = affs_bread_ino(inode, bidx, 0); 573 if (IS_ERR(bh)) 574 return PTR_ERR(bh); 575 tmp = min(bsize - boff, newsize - size); 576 BUG_ON(boff + tmp > bsize || tmp > bsize); 577 memset(AFFS_DATA(bh) + boff, 0, tmp); 578 be32_add_cpu(&AFFS_DATA_HEAD(bh)->size, tmp); 579 affs_fix_checksum(sb, bh); 580 mark_buffer_dirty_inode(bh, inode); 581 size += tmp; 582 bidx++; 583 } else if (bidx) { 584 bh = affs_bread_ino(inode, bidx - 1, 0); 585 if (IS_ERR(bh)) 586 return PTR_ERR(bh); 587 } 588 589 while (size < newsize) { 590 prev_bh = bh; 591 bh = affs_getzeroblk_ino(inode, bidx); 592 if (IS_ERR(bh)) 593 goto out; 594 tmp = min(bsize, newsize - size); 595 BUG_ON(tmp > bsize); 596 AFFS_DATA_HEAD(bh)->ptype = cpu_to_be32(T_DATA); 597 AFFS_DATA_HEAD(bh)->key = cpu_to_be32(inode->i_ino); 598 AFFS_DATA_HEAD(bh)->sequence = cpu_to_be32(bidx); 599 AFFS_DATA_HEAD(bh)->size = cpu_to_be32(tmp); 600 affs_fix_checksum(sb, bh); 601 bh->b_state &= ~(1UL << BH_New); 602 mark_buffer_dirty_inode(bh, inode); 603 if (prev_bh) { 604 u32 tmp_next = be32_to_cpu(AFFS_DATA_HEAD(prev_bh)->next); 605 606 if (tmp_next) 607 affs_warning(sb, "extent_file_ofs", 608 "next block already set for %d (%d)", 609 bidx, tmp_next); 610 AFFS_DATA_HEAD(prev_bh)->next = cpu_to_be32(bh->b_blocknr); 611 affs_adjust_checksum(prev_bh, bh->b_blocknr - tmp_next); 612 mark_buffer_dirty_inode(prev_bh, inode); 613 affs_brelse(prev_bh); 614 } 615 size += bsize; 616 bidx++; 617 } 618 affs_brelse(bh); 619 inode->i_size = AFFS_I(inode)->mmu_private = newsize; 620 return 0; 621 622 out: 623 inode->i_size = AFFS_I(inode)->mmu_private = newsize; 624 return PTR_ERR(bh); 625 } 626 627 static int 628 affs_read_folio_ofs(struct file *file, struct folio *folio) 629 { 630 struct page *page = &folio->page; 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, 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); 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 .dirty_folio = block_dirty_folio, 836 .invalidate_folio = block_invalidate_folio, 837 .read_folio = affs_read_folio_ofs, 838 //.writepage = affs_writepage_ofs, 839 .write_begin = affs_write_begin_ofs, 840 .write_end = affs_write_end_ofs 841 }; 842 843 /* Free any preallocated blocks. */ 844 845 void 846 affs_free_prealloc(struct inode *inode) 847 { 848 struct super_block *sb = inode->i_sb; 849 850 pr_debug("free_prealloc(ino=%lu)\n", inode->i_ino); 851 852 while (AFFS_I(inode)->i_pa_cnt) { 853 AFFS_I(inode)->i_pa_cnt--; 854 affs_free_block(sb, ++AFFS_I(inode)->i_lastalloc); 855 } 856 } 857 858 /* Truncate (or enlarge) a file to the requested size. */ 859 860 void 861 affs_truncate(struct inode *inode) 862 { 863 struct super_block *sb = inode->i_sb; 864 u32 ext, ext_key; 865 u32 last_blk, blkcnt, blk; 866 u32 size; 867 struct buffer_head *ext_bh; 868 int i; 869 870 pr_debug("truncate(inode=%lu, oldsize=%llu, newsize=%llu)\n", 871 inode->i_ino, AFFS_I(inode)->mmu_private, inode->i_size); 872 873 last_blk = 0; 874 ext = 0; 875 if (inode->i_size) { 876 last_blk = ((u32)inode->i_size - 1) / AFFS_SB(sb)->s_data_blksize; 877 ext = last_blk / AFFS_SB(sb)->s_hashsize; 878 } 879 880 if (inode->i_size > AFFS_I(inode)->mmu_private) { 881 struct address_space *mapping = inode->i_mapping; 882 struct page *page; 883 void *fsdata = NULL; 884 loff_t isize = inode->i_size; 885 int res; 886 887 res = mapping->a_ops->write_begin(NULL, mapping, isize, 0, &page, &fsdata); 888 if (!res) 889 res = mapping->a_ops->write_end(NULL, mapping, isize, 0, 0, page, fsdata); 890 else 891 inode->i_size = AFFS_I(inode)->mmu_private; 892 mark_inode_dirty(inode); 893 return; 894 } else if (inode->i_size == AFFS_I(inode)->mmu_private) 895 return; 896 897 // lock cache 898 ext_bh = affs_get_extblock(inode, ext); 899 if (IS_ERR(ext_bh)) { 900 affs_warning(sb, "truncate", 901 "unexpected read error for ext block %u (%ld)", 902 ext, PTR_ERR(ext_bh)); 903 return; 904 } 905 if (AFFS_I(inode)->i_lc) { 906 /* clear linear cache */ 907 i = (ext + 1) >> AFFS_I(inode)->i_lc_shift; 908 if (AFFS_I(inode)->i_lc_size > i) { 909 AFFS_I(inode)->i_lc_size = i; 910 for (; i < AFFS_LC_SIZE; i++) 911 AFFS_I(inode)->i_lc[i] = 0; 912 } 913 /* clear associative cache */ 914 for (i = 0; i < AFFS_AC_SIZE; i++) 915 if (AFFS_I(inode)->i_ac[i].ext >= ext) 916 AFFS_I(inode)->i_ac[i].ext = 0; 917 } 918 ext_key = be32_to_cpu(AFFS_TAIL(sb, ext_bh)->extension); 919 920 blkcnt = AFFS_I(inode)->i_blkcnt; 921 i = 0; 922 blk = last_blk; 923 if (inode->i_size) { 924 i = last_blk % AFFS_SB(sb)->s_hashsize + 1; 925 blk++; 926 } else 927 AFFS_HEAD(ext_bh)->first_data = 0; 928 AFFS_HEAD(ext_bh)->block_count = cpu_to_be32(i); 929 size = AFFS_SB(sb)->s_hashsize; 930 if (size > blkcnt - blk + i) 931 size = blkcnt - blk + i; 932 for (; i < size; i++, blk++) { 933 affs_free_block(sb, be32_to_cpu(AFFS_BLOCK(sb, ext_bh, i))); 934 AFFS_BLOCK(sb, ext_bh, i) = 0; 935 } 936 AFFS_TAIL(sb, ext_bh)->extension = 0; 937 affs_fix_checksum(sb, ext_bh); 938 mark_buffer_dirty_inode(ext_bh, inode); 939 affs_brelse(ext_bh); 940 941 if (inode->i_size) { 942 AFFS_I(inode)->i_blkcnt = last_blk + 1; 943 AFFS_I(inode)->i_extcnt = ext + 1; 944 if (affs_test_opt(AFFS_SB(sb)->s_flags, SF_OFS)) { 945 struct buffer_head *bh = affs_bread_ino(inode, last_blk, 0); 946 u32 tmp; 947 if (IS_ERR(bh)) { 948 affs_warning(sb, "truncate", 949 "unexpected read error for last block %u (%ld)", 950 ext, PTR_ERR(bh)); 951 return; 952 } 953 tmp = be32_to_cpu(AFFS_DATA_HEAD(bh)->next); 954 AFFS_DATA_HEAD(bh)->next = 0; 955 affs_adjust_checksum(bh, -tmp); 956 affs_brelse(bh); 957 } 958 } else { 959 AFFS_I(inode)->i_blkcnt = 0; 960 AFFS_I(inode)->i_extcnt = 1; 961 } 962 AFFS_I(inode)->mmu_private = inode->i_size; 963 // unlock cache 964 965 while (ext_key) { 966 ext_bh = affs_bread(sb, ext_key); 967 size = AFFS_SB(sb)->s_hashsize; 968 if (size > blkcnt - blk) 969 size = blkcnt - blk; 970 for (i = 0; i < size; i++, blk++) 971 affs_free_block(sb, be32_to_cpu(AFFS_BLOCK(sb, ext_bh, i))); 972 affs_free_block(sb, ext_key); 973 ext_key = be32_to_cpu(AFFS_TAIL(sb, ext_bh)->extension); 974 affs_brelse(ext_bh); 975 } 976 affs_free_prealloc(inode); 977 } 978 979 int affs_file_fsync(struct file *filp, loff_t start, loff_t end, int datasync) 980 { 981 struct inode *inode = filp->f_mapping->host; 982 int ret, err; 983 984 err = file_write_and_wait_range(filp, start, end); 985 if (err) 986 return err; 987 988 inode_lock(inode); 989 ret = write_inode_now(inode, 0); 990 err = sync_blockdev(inode->i_sb->s_bdev); 991 if (!ret) 992 ret = err; 993 inode_unlock(inode); 994 return ret; 995 } 996 const struct file_operations affs_file_operations = { 997 .llseek = generic_file_llseek, 998 .read_iter = generic_file_read_iter, 999 .write_iter = generic_file_write_iter, 1000 .mmap = generic_file_mmap, 1001 .open = affs_file_open, 1002 .release = affs_file_release, 1003 .fsync = affs_file_fsync, 1004 .splice_read = filemap_splice_read, 1005 }; 1006 1007 const struct inode_operations affs_file_inode_operations = { 1008 .setattr = affs_notify_change, 1009 }; 1010