1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * linux/fs/affs/file.c 4 * 5 * (c) 1996 Hans-Joachim Widmaier - Rewritten 6 * 7 * (C) 1993 Ray Burr - Modified for Amiga FFS filesystem. 8 * 9 * (C) 1992 Eric Youngdale Modified for ISO 9660 filesystem. 10 * 11 * (C) 1991 Linus Torvalds - minix filesystem 12 * 13 * affs regular file handling primitives 14 */ 15 16 #include <linux/uio.h> 17 #include <linux/blkdev.h> 18 #include "affs.h" 19 20 static struct buffer_head *affs_get_extblock_slow(struct inode *inode, u32 ext); 21 22 static int 23 affs_file_open(struct inode *inode, struct file *filp) 24 { 25 pr_debug("open(%lu,%d)\n", 26 inode->i_ino, atomic_read(&AFFS_I(inode)->i_opencnt)); 27 atomic_inc(&AFFS_I(inode)->i_opencnt); 28 return 0; 29 } 30 31 static int 32 affs_file_release(struct inode *inode, struct file *filp) 33 { 34 pr_debug("release(%lu, %d)\n", 35 inode->i_ino, atomic_read(&AFFS_I(inode)->i_opencnt)); 36 37 if (atomic_dec_and_test(&AFFS_I(inode)->i_opencnt)) { 38 inode_lock(inode); 39 if (inode->i_size != AFFS_I(inode)->mmu_private) 40 affs_truncate(inode); 41 affs_free_prealloc(inode); 42 inode_unlock(inode); 43 } 44 45 return 0; 46 } 47 48 static int 49 affs_grow_extcache(struct inode *inode, u32 lc_idx) 50 { 51 struct super_block *sb = inode->i_sb; 52 struct buffer_head *bh; 53 u32 lc_max; 54 int i, j, key; 55 56 if (!AFFS_I(inode)->i_lc) { 57 char *ptr = (char *)get_zeroed_page(GFP_NOFS); 58 if (!ptr) 59 return -ENOMEM; 60 AFFS_I(inode)->i_lc = (u32 *)ptr; 61 AFFS_I(inode)->i_ac = (struct affs_ext_key *)(ptr + AFFS_CACHE_SIZE / 2); 62 } 63 64 lc_max = AFFS_LC_SIZE << AFFS_I(inode)->i_lc_shift; 65 66 if (AFFS_I(inode)->i_extcnt > lc_max) { 67 u32 lc_shift, lc_mask, tmp, off; 68 69 /* need to recalculate linear cache, start from old size */ 70 lc_shift = AFFS_I(inode)->i_lc_shift; 71 tmp = (AFFS_I(inode)->i_extcnt / AFFS_LC_SIZE) >> lc_shift; 72 for (; tmp; tmp >>= 1) 73 lc_shift++; 74 lc_mask = (1 << lc_shift) - 1; 75 76 /* fix idx and old size to new shift */ 77 lc_idx >>= (lc_shift - AFFS_I(inode)->i_lc_shift); 78 AFFS_I(inode)->i_lc_size >>= (lc_shift - AFFS_I(inode)->i_lc_shift); 79 80 /* first shrink old cache to make more space */ 81 off = 1 << (lc_shift - AFFS_I(inode)->i_lc_shift); 82 for (i = 1, j = off; j < AFFS_LC_SIZE; i++, j += off) 83 AFFS_I(inode)->i_ac[i] = AFFS_I(inode)->i_ac[j]; 84 85 AFFS_I(inode)->i_lc_shift = lc_shift; 86 AFFS_I(inode)->i_lc_mask = lc_mask; 87 } 88 89 /* fill cache to the needed index */ 90 i = AFFS_I(inode)->i_lc_size; 91 AFFS_I(inode)->i_lc_size = lc_idx + 1; 92 for (; i <= lc_idx; i++) { 93 if (!i) { 94 AFFS_I(inode)->i_lc[0] = inode->i_ino; 95 continue; 96 } 97 key = AFFS_I(inode)->i_lc[i - 1]; 98 j = AFFS_I(inode)->i_lc_mask + 1; 99 // unlock cache 100 for (; j > 0; j--) { 101 bh = affs_bread(sb, key); 102 if (!bh) 103 goto err; 104 key = be32_to_cpu(AFFS_TAIL(sb, bh)->extension); 105 affs_brelse(bh); 106 } 107 // lock cache 108 AFFS_I(inode)->i_lc[i] = key; 109 } 110 111 return 0; 112 113 err: 114 // lock cache 115 return -EIO; 116 } 117 118 static struct buffer_head * 119 affs_alloc_extblock(struct inode *inode, struct buffer_head *bh, u32 ext) 120 { 121 struct super_block *sb = inode->i_sb; 122 struct buffer_head *new_bh; 123 u32 blocknr, tmp; 124 125 blocknr = affs_alloc_block(inode, bh->b_blocknr); 126 if (!blocknr) 127 return ERR_PTR(-ENOSPC); 128 129 new_bh = affs_getzeroblk(sb, blocknr); 130 if (!new_bh) { 131 affs_free_block(sb, blocknr); 132 return ERR_PTR(-EIO); 133 } 134 135 AFFS_HEAD(new_bh)->ptype = cpu_to_be32(T_LIST); 136 AFFS_HEAD(new_bh)->key = cpu_to_be32(blocknr); 137 AFFS_TAIL(sb, new_bh)->stype = cpu_to_be32(ST_FILE); 138 AFFS_TAIL(sb, new_bh)->parent = cpu_to_be32(inode->i_ino); 139 affs_fix_checksum(sb, new_bh); 140 141 mark_buffer_dirty_inode(new_bh, inode); 142 143 tmp = be32_to_cpu(AFFS_TAIL(sb, bh)->extension); 144 if (tmp) 145 affs_warning(sb, "alloc_ext", "previous extension set (%x)", tmp); 146 AFFS_TAIL(sb, bh)->extension = cpu_to_be32(blocknr); 147 affs_adjust_checksum(bh, blocknr - tmp); 148 mark_buffer_dirty_inode(bh, inode); 149 150 AFFS_I(inode)->i_extcnt++; 151 mark_inode_dirty(inode); 152 153 return new_bh; 154 } 155 156 static inline struct buffer_head * 157 affs_get_extblock(struct inode *inode, u32 ext) 158 { 159 /* inline the simplest case: same extended block as last time */ 160 struct buffer_head *bh = AFFS_I(inode)->i_ext_bh; 161 if (ext == AFFS_I(inode)->i_ext_last) 162 get_bh(bh); 163 else 164 /* we have to do more (not inlined) */ 165 bh = affs_get_extblock_slow(inode, ext); 166 167 return bh; 168 } 169 170 static struct buffer_head * 171 affs_get_extblock_slow(struct inode *inode, u32 ext) 172 { 173 struct super_block *sb = inode->i_sb; 174 struct buffer_head *bh; 175 u32 ext_key; 176 u32 lc_idx, lc_off, ac_idx; 177 u32 tmp, idx; 178 179 if (ext == AFFS_I(inode)->i_ext_last + 1) { 180 /* read the next extended block from the current one */ 181 bh = AFFS_I(inode)->i_ext_bh; 182 ext_key = be32_to_cpu(AFFS_TAIL(sb, bh)->extension); 183 if (ext < AFFS_I(inode)->i_extcnt) 184 goto read_ext; 185 BUG_ON(ext > AFFS_I(inode)->i_extcnt); 186 bh = affs_alloc_extblock(inode, bh, ext); 187 if (IS_ERR(bh)) 188 return bh; 189 goto store_ext; 190 } 191 192 if (ext == 0) { 193 /* we seek back to the file header block */ 194 ext_key = inode->i_ino; 195 goto read_ext; 196 } 197 198 if (ext >= AFFS_I(inode)->i_extcnt) { 199 struct buffer_head *prev_bh; 200 201 /* allocate a new extended block */ 202 BUG_ON(ext > AFFS_I(inode)->i_extcnt); 203 204 /* get previous extended block */ 205 prev_bh = affs_get_extblock(inode, ext - 1); 206 if (IS_ERR(prev_bh)) 207 return prev_bh; 208 bh = affs_alloc_extblock(inode, prev_bh, ext); 209 affs_brelse(prev_bh); 210 if (IS_ERR(bh)) 211 return bh; 212 goto store_ext; 213 } 214 215 again: 216 /* check if there is an extended cache and whether it's large enough */ 217 lc_idx = ext >> AFFS_I(inode)->i_lc_shift; 218 lc_off = ext & AFFS_I(inode)->i_lc_mask; 219 220 if (lc_idx >= AFFS_I(inode)->i_lc_size) { 221 int err; 222 223 err = affs_grow_extcache(inode, lc_idx); 224 if (err) 225 return ERR_PTR(err); 226 goto again; 227 } 228 229 /* every n'th key we find in the linear cache */ 230 if (!lc_off) { 231 ext_key = AFFS_I(inode)->i_lc[lc_idx]; 232 goto read_ext; 233 } 234 235 /* maybe it's still in the associative cache */ 236 ac_idx = (ext - lc_idx - 1) & AFFS_AC_MASK; 237 if (AFFS_I(inode)->i_ac[ac_idx].ext == ext) { 238 ext_key = AFFS_I(inode)->i_ac[ac_idx].key; 239 goto read_ext; 240 } 241 242 /* try to find one of the previous extended blocks */ 243 tmp = ext; 244 idx = ac_idx; 245 while (--tmp, --lc_off > 0) { 246 idx = (idx - 1) & AFFS_AC_MASK; 247 if (AFFS_I(inode)->i_ac[idx].ext == tmp) { 248 ext_key = AFFS_I(inode)->i_ac[idx].key; 249 goto find_ext; 250 } 251 } 252 253 /* fall back to the linear cache */ 254 ext_key = AFFS_I(inode)->i_lc[lc_idx]; 255 find_ext: 256 /* read all extended blocks until we find the one we need */ 257 //unlock cache 258 do { 259 bh = affs_bread(sb, ext_key); 260 if (!bh) 261 goto err_bread; 262 ext_key = be32_to_cpu(AFFS_TAIL(sb, bh)->extension); 263 affs_brelse(bh); 264 tmp++; 265 } while (tmp < ext); 266 //lock cache 267 268 /* store it in the associative cache */ 269 // recalculate ac_idx? 270 AFFS_I(inode)->i_ac[ac_idx].ext = ext; 271 AFFS_I(inode)->i_ac[ac_idx].key = ext_key; 272 273 read_ext: 274 /* finally read the right extended block */ 275 //unlock cache 276 bh = affs_bread(sb, ext_key); 277 if (!bh) 278 goto err_bread; 279 //lock cache 280 281 store_ext: 282 /* release old cached extended block and store the new one */ 283 affs_brelse(AFFS_I(inode)->i_ext_bh); 284 AFFS_I(inode)->i_ext_last = ext; 285 AFFS_I(inode)->i_ext_bh = bh; 286 get_bh(bh); 287 288 return bh; 289 290 err_bread: 291 affs_brelse(bh); 292 return ERR_PTR(-EIO); 293 } 294 295 static int 296 affs_get_block(struct inode *inode, sector_t block, struct buffer_head *bh_result, int create) 297 { 298 struct super_block *sb = inode->i_sb; 299 struct buffer_head *ext_bh; 300 u32 ext; 301 302 pr_debug("%s(%lu, %llu)\n", __func__, inode->i_ino, 303 (unsigned long long)block); 304 305 BUG_ON(block > (sector_t)0x7fffffffUL); 306 307 if (block >= AFFS_I(inode)->i_blkcnt) { 308 if (block > AFFS_I(inode)->i_blkcnt || !create) 309 goto err_big; 310 } else 311 create = 0; 312 313 //lock cache 314 affs_lock_ext(inode); 315 316 ext = (u32)block / AFFS_SB(sb)->s_hashsize; 317 block -= ext * AFFS_SB(sb)->s_hashsize; 318 ext_bh = affs_get_extblock(inode, ext); 319 if (IS_ERR(ext_bh)) 320 goto err_ext; 321 map_bh(bh_result, sb, (sector_t)be32_to_cpu(AFFS_BLOCK(sb, ext_bh, block))); 322 323 if (create) { 324 u32 blocknr = affs_alloc_block(inode, ext_bh->b_blocknr); 325 if (!blocknr) 326 goto err_alloc; 327 set_buffer_new(bh_result); 328 AFFS_I(inode)->mmu_private += AFFS_SB(sb)->s_data_blksize; 329 AFFS_I(inode)->i_blkcnt++; 330 331 /* store new block */ 332 if (bh_result->b_blocknr) 333 affs_warning(sb, "get_block", 334 "block already set (%llx)", 335 (unsigned long long)bh_result->b_blocknr); 336 AFFS_BLOCK(sb, ext_bh, block) = cpu_to_be32(blocknr); 337 AFFS_HEAD(ext_bh)->block_count = cpu_to_be32(block + 1); 338 affs_adjust_checksum(ext_bh, blocknr - bh_result->b_blocknr + 1); 339 bh_result->b_blocknr = blocknr; 340 341 if (!block) { 342 /* insert first block into header block */ 343 u32 tmp = be32_to_cpu(AFFS_HEAD(ext_bh)->first_data); 344 if (tmp) 345 affs_warning(sb, "get_block", "first block already set (%d)", tmp); 346 AFFS_HEAD(ext_bh)->first_data = cpu_to_be32(blocknr); 347 affs_adjust_checksum(ext_bh, blocknr - tmp); 348 } 349 } 350 351 affs_brelse(ext_bh); 352 //unlock cache 353 affs_unlock_ext(inode); 354 return 0; 355 356 err_big: 357 affs_error(inode->i_sb, "get_block", "strange block request %llu", 358 (unsigned long long)block); 359 return -EIO; 360 err_ext: 361 // unlock cache 362 affs_unlock_ext(inode); 363 return PTR_ERR(ext_bh); 364 err_alloc: 365 brelse(ext_bh); 366 clear_buffer_mapped(bh_result); 367 bh_result->b_bdev = NULL; 368 // unlock cache 369 affs_unlock_ext(inode); 370 return -ENOSPC; 371 } 372 373 static int affs_writepage(struct page *page, struct writeback_control *wbc) 374 { 375 return block_write_full_page(page, affs_get_block, wbc); 376 } 377 378 static int affs_readpage(struct file *file, struct page *page) 379 { 380 return block_read_full_page(page, affs_get_block); 381 } 382 383 static void affs_write_failed(struct address_space *mapping, loff_t to) 384 { 385 struct inode *inode = mapping->host; 386 387 if (to > inode->i_size) { 388 truncate_pagecache(inode, inode->i_size); 389 affs_truncate(inode); 390 } 391 } 392 393 static ssize_t 394 affs_direct_IO(struct kiocb *iocb, struct iov_iter *iter) 395 { 396 struct file *file = iocb->ki_filp; 397 struct address_space *mapping = file->f_mapping; 398 struct inode *inode = mapping->host; 399 size_t count = iov_iter_count(iter); 400 loff_t offset = iocb->ki_pos; 401 ssize_t ret; 402 403 if (iov_iter_rw(iter) == WRITE) { 404 loff_t size = offset + count; 405 406 if (AFFS_I(inode)->mmu_private < size) 407 return 0; 408 } 409 410 ret = blockdev_direct_IO(iocb, inode, iter, affs_get_block); 411 if (ret < 0 && iov_iter_rw(iter) == WRITE) 412 affs_write_failed(mapping, offset + count); 413 return ret; 414 } 415 416 static int affs_write_begin(struct file *file, struct address_space *mapping, 417 loff_t pos, unsigned len, unsigned flags, 418 struct page **pagep, void **fsdata) 419 { 420 int ret; 421 422 *pagep = NULL; 423 ret = cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata, 424 affs_get_block, 425 &AFFS_I(mapping->host)->mmu_private); 426 if (unlikely(ret)) 427 affs_write_failed(mapping, pos + len); 428 429 return ret; 430 } 431 432 static int affs_write_end(struct file *file, struct address_space *mapping, 433 loff_t pos, unsigned int len, unsigned int copied, 434 struct page *page, void *fsdata) 435 { 436 struct inode *inode = mapping->host; 437 int ret; 438 439 ret = generic_write_end(file, mapping, pos, len, copied, page, fsdata); 440 441 /* Clear Archived bit on file writes, as AmigaOS would do */ 442 if (AFFS_I(inode)->i_protect & FIBF_ARCHIVED) { 443 AFFS_I(inode)->i_protect &= ~FIBF_ARCHIVED; 444 mark_inode_dirty(inode); 445 } 446 447 return ret; 448 } 449 450 static sector_t _affs_bmap(struct address_space *mapping, sector_t block) 451 { 452 return generic_block_bmap(mapping,block,affs_get_block); 453 } 454 455 const struct address_space_operations affs_aops = { 456 .readpage = affs_readpage, 457 .writepage = affs_writepage, 458 .write_begin = affs_write_begin, 459 .write_end = affs_write_end, 460 .direct_IO = affs_direct_IO, 461 .bmap = _affs_bmap 462 }; 463 464 static inline struct buffer_head * 465 affs_bread_ino(struct inode *inode, int block, int create) 466 { 467 struct buffer_head *bh, tmp_bh; 468 int err; 469 470 tmp_bh.b_state = 0; 471 err = affs_get_block(inode, block, &tmp_bh, create); 472 if (!err) { 473 bh = affs_bread(inode->i_sb, tmp_bh.b_blocknr); 474 if (bh) { 475 bh->b_state |= tmp_bh.b_state; 476 return bh; 477 } 478 err = -EIO; 479 } 480 return ERR_PTR(err); 481 } 482 483 static inline struct buffer_head * 484 affs_getzeroblk_ino(struct inode *inode, int block) 485 { 486 struct buffer_head *bh, tmp_bh; 487 int err; 488 489 tmp_bh.b_state = 0; 490 err = affs_get_block(inode, block, &tmp_bh, 1); 491 if (!err) { 492 bh = affs_getzeroblk(inode->i_sb, tmp_bh.b_blocknr); 493 if (bh) { 494 bh->b_state |= tmp_bh.b_state; 495 return bh; 496 } 497 err = -EIO; 498 } 499 return ERR_PTR(err); 500 } 501 502 static inline struct buffer_head * 503 affs_getemptyblk_ino(struct inode *inode, int block) 504 { 505 struct buffer_head *bh, tmp_bh; 506 int err; 507 508 tmp_bh.b_state = 0; 509 err = affs_get_block(inode, block, &tmp_bh, 1); 510 if (!err) { 511 bh = affs_getemptyblk(inode->i_sb, tmp_bh.b_blocknr); 512 if (bh) { 513 bh->b_state |= tmp_bh.b_state; 514 return bh; 515 } 516 err = -EIO; 517 } 518 return ERR_PTR(err); 519 } 520 521 static int 522 affs_do_readpage_ofs(struct page *page, unsigned to, int create) 523 { 524 struct inode *inode = page->mapping->host; 525 struct super_block *sb = inode->i_sb; 526 struct buffer_head *bh; 527 char *data; 528 unsigned pos = 0; 529 u32 bidx, boff, bsize; 530 u32 tmp; 531 532 pr_debug("%s(%lu, %ld, 0, %d)\n", __func__, inode->i_ino, 533 page->index, to); 534 BUG_ON(to > PAGE_SIZE); 535 bsize = AFFS_SB(sb)->s_data_blksize; 536 tmp = page->index << PAGE_SHIFT; 537 bidx = tmp / bsize; 538 boff = tmp % bsize; 539 540 while (pos < to) { 541 bh = affs_bread_ino(inode, bidx, create); 542 if (IS_ERR(bh)) 543 return PTR_ERR(bh); 544 tmp = min(bsize - boff, to - pos); 545 BUG_ON(pos + tmp > to || tmp > bsize); 546 data = kmap_atomic(page); 547 memcpy(data + pos, AFFS_DATA(bh) + boff, tmp); 548 kunmap_atomic(data); 549 affs_brelse(bh); 550 bidx++; 551 pos += tmp; 552 boff = 0; 553 } 554 flush_dcache_page(page); 555 return 0; 556 } 557 558 static int 559 affs_extent_file_ofs(struct inode *inode, u32 newsize) 560 { 561 struct super_block *sb = inode->i_sb; 562 struct buffer_head *bh, *prev_bh; 563 u32 bidx, boff; 564 u32 size, bsize; 565 u32 tmp; 566 567 pr_debug("%s(%lu, %d)\n", __func__, inode->i_ino, newsize); 568 bsize = AFFS_SB(sb)->s_data_blksize; 569 bh = NULL; 570 size = AFFS_I(inode)->mmu_private; 571 bidx = size / bsize; 572 boff = size % bsize; 573 if (boff) { 574 bh = affs_bread_ino(inode, bidx, 0); 575 if (IS_ERR(bh)) 576 return PTR_ERR(bh); 577 tmp = min(bsize - boff, newsize - size); 578 BUG_ON(boff + tmp > bsize || tmp > bsize); 579 memset(AFFS_DATA(bh) + boff, 0, tmp); 580 be32_add_cpu(&AFFS_DATA_HEAD(bh)->size, tmp); 581 affs_fix_checksum(sb, bh); 582 mark_buffer_dirty_inode(bh, inode); 583 size += tmp; 584 bidx++; 585 } else if (bidx) { 586 bh = affs_bread_ino(inode, bidx - 1, 0); 587 if (IS_ERR(bh)) 588 return PTR_ERR(bh); 589 } 590 591 while (size < newsize) { 592 prev_bh = bh; 593 bh = affs_getzeroblk_ino(inode, bidx); 594 if (IS_ERR(bh)) 595 goto out; 596 tmp = min(bsize, newsize - size); 597 BUG_ON(tmp > bsize); 598 AFFS_DATA_HEAD(bh)->ptype = cpu_to_be32(T_DATA); 599 AFFS_DATA_HEAD(bh)->key = cpu_to_be32(inode->i_ino); 600 AFFS_DATA_HEAD(bh)->sequence = cpu_to_be32(bidx); 601 AFFS_DATA_HEAD(bh)->size = cpu_to_be32(tmp); 602 affs_fix_checksum(sb, bh); 603 bh->b_state &= ~(1UL << BH_New); 604 mark_buffer_dirty_inode(bh, inode); 605 if (prev_bh) { 606 u32 tmp_next = be32_to_cpu(AFFS_DATA_HEAD(prev_bh)->next); 607 608 if (tmp_next) 609 affs_warning(sb, "extent_file_ofs", 610 "next block already set for %d (%d)", 611 bidx, tmp_next); 612 AFFS_DATA_HEAD(prev_bh)->next = cpu_to_be32(bh->b_blocknr); 613 affs_adjust_checksum(prev_bh, bh->b_blocknr - tmp_next); 614 mark_buffer_dirty_inode(prev_bh, inode); 615 affs_brelse(prev_bh); 616 } 617 size += bsize; 618 bidx++; 619 } 620 affs_brelse(bh); 621 inode->i_size = AFFS_I(inode)->mmu_private = newsize; 622 return 0; 623 624 out: 625 inode->i_size = AFFS_I(inode)->mmu_private = newsize; 626 return PTR_ERR(bh); 627 } 628 629 static int 630 affs_readpage_ofs(struct file *file, struct page *page) 631 { 632 struct inode *inode = page->mapping->host; 633 u32 to; 634 int err; 635 636 pr_debug("%s(%lu, %ld)\n", __func__, inode->i_ino, page->index); 637 to = PAGE_SIZE; 638 if (((page->index + 1) << PAGE_SHIFT) > inode->i_size) { 639 to = inode->i_size & ~PAGE_MASK; 640 memset(page_address(page) + to, 0, PAGE_SIZE - to); 641 } 642 643 err = affs_do_readpage_ofs(page, to, 0); 644 if (!err) 645 SetPageUptodate(page); 646 unlock_page(page); 647 return err; 648 } 649 650 static int affs_write_begin_ofs(struct file *file, struct address_space *mapping, 651 loff_t pos, unsigned len, unsigned flags, 652 struct page **pagep, void **fsdata) 653 { 654 struct inode *inode = mapping->host; 655 struct page *page; 656 pgoff_t index; 657 int err = 0; 658 659 pr_debug("%s(%lu, %llu, %llu)\n", __func__, inode->i_ino, pos, 660 pos + len); 661 if (pos > AFFS_I(inode)->mmu_private) { 662 /* XXX: this probably leaves a too-big i_size in case of 663 * failure. Should really be updating i_size at write_end time 664 */ 665 err = affs_extent_file_ofs(inode, pos); 666 if (err) 667 return err; 668 } 669 670 index = pos >> PAGE_SHIFT; 671 page = grab_cache_page_write_begin(mapping, index, flags); 672 if (!page) 673 return -ENOMEM; 674 *pagep = page; 675 676 if (PageUptodate(page)) 677 return 0; 678 679 /* XXX: inefficient but safe in the face of short writes */ 680 err = affs_do_readpage_ofs(page, PAGE_SIZE, 1); 681 if (err) { 682 unlock_page(page); 683 put_page(page); 684 } 685 return err; 686 } 687 688 static int affs_write_end_ofs(struct file *file, struct address_space *mapping, 689 loff_t pos, unsigned len, unsigned copied, 690 struct page *page, void *fsdata) 691 { 692 struct inode *inode = mapping->host; 693 struct super_block *sb = inode->i_sb; 694 struct buffer_head *bh, *prev_bh; 695 char *data; 696 u32 bidx, boff, bsize; 697 unsigned from, to; 698 u32 tmp; 699 int written; 700 701 from = pos & (PAGE_SIZE - 1); 702 to = from + len; 703 /* 704 * XXX: not sure if this can handle short copies (len < copied), but 705 * we don't have to, because the page should always be uptodate here, 706 * due to write_begin. 707 */ 708 709 pr_debug("%s(%lu, %llu, %llu)\n", __func__, inode->i_ino, pos, 710 pos + len); 711 bsize = AFFS_SB(sb)->s_data_blksize; 712 data = page_address(page); 713 714 bh = NULL; 715 written = 0; 716 tmp = (page->index << PAGE_SHIFT) + from; 717 bidx = tmp / bsize; 718 boff = tmp % bsize; 719 if (boff) { 720 bh = affs_bread_ino(inode, bidx, 0); 721 if (IS_ERR(bh)) { 722 written = PTR_ERR(bh); 723 goto err_first_bh; 724 } 725 tmp = min(bsize - boff, to - from); 726 BUG_ON(boff + tmp > bsize || tmp > bsize); 727 memcpy(AFFS_DATA(bh) + boff, data + from, tmp); 728 be32_add_cpu(&AFFS_DATA_HEAD(bh)->size, tmp); 729 affs_fix_checksum(sb, bh); 730 mark_buffer_dirty_inode(bh, inode); 731 written += tmp; 732 from += tmp; 733 bidx++; 734 } else if (bidx) { 735 bh = affs_bread_ino(inode, bidx - 1, 0); 736 if (IS_ERR(bh)) { 737 written = PTR_ERR(bh); 738 goto err_first_bh; 739 } 740 } 741 while (from + bsize <= to) { 742 prev_bh = bh; 743 bh = affs_getemptyblk_ino(inode, bidx); 744 if (IS_ERR(bh)) 745 goto err_bh; 746 memcpy(AFFS_DATA(bh), data + from, bsize); 747 if (buffer_new(bh)) { 748 AFFS_DATA_HEAD(bh)->ptype = cpu_to_be32(T_DATA); 749 AFFS_DATA_HEAD(bh)->key = cpu_to_be32(inode->i_ino); 750 AFFS_DATA_HEAD(bh)->sequence = cpu_to_be32(bidx); 751 AFFS_DATA_HEAD(bh)->size = cpu_to_be32(bsize); 752 AFFS_DATA_HEAD(bh)->next = 0; 753 bh->b_state &= ~(1UL << BH_New); 754 if (prev_bh) { 755 u32 tmp_next = be32_to_cpu(AFFS_DATA_HEAD(prev_bh)->next); 756 757 if (tmp_next) 758 affs_warning(sb, "commit_write_ofs", 759 "next block already set for %d (%d)", 760 bidx, tmp_next); 761 AFFS_DATA_HEAD(prev_bh)->next = cpu_to_be32(bh->b_blocknr); 762 affs_adjust_checksum(prev_bh, bh->b_blocknr - tmp_next); 763 mark_buffer_dirty_inode(prev_bh, inode); 764 } 765 } 766 affs_brelse(prev_bh); 767 affs_fix_checksum(sb, bh); 768 mark_buffer_dirty_inode(bh, inode); 769 written += bsize; 770 from += bsize; 771 bidx++; 772 } 773 if (from < to) { 774 prev_bh = bh; 775 bh = affs_bread_ino(inode, bidx, 1); 776 if (IS_ERR(bh)) 777 goto err_bh; 778 tmp = min(bsize, to - from); 779 BUG_ON(tmp > bsize); 780 memcpy(AFFS_DATA(bh), data + from, tmp); 781 if (buffer_new(bh)) { 782 AFFS_DATA_HEAD(bh)->ptype = cpu_to_be32(T_DATA); 783 AFFS_DATA_HEAD(bh)->key = cpu_to_be32(inode->i_ino); 784 AFFS_DATA_HEAD(bh)->sequence = cpu_to_be32(bidx); 785 AFFS_DATA_HEAD(bh)->size = cpu_to_be32(tmp); 786 AFFS_DATA_HEAD(bh)->next = 0; 787 bh->b_state &= ~(1UL << BH_New); 788 if (prev_bh) { 789 u32 tmp_next = be32_to_cpu(AFFS_DATA_HEAD(prev_bh)->next); 790 791 if (tmp_next) 792 affs_warning(sb, "commit_write_ofs", 793 "next block already set for %d (%d)", 794 bidx, tmp_next); 795 AFFS_DATA_HEAD(prev_bh)->next = cpu_to_be32(bh->b_blocknr); 796 affs_adjust_checksum(prev_bh, bh->b_blocknr - tmp_next); 797 mark_buffer_dirty_inode(prev_bh, inode); 798 } 799 } else if (be32_to_cpu(AFFS_DATA_HEAD(bh)->size) < tmp) 800 AFFS_DATA_HEAD(bh)->size = cpu_to_be32(tmp); 801 affs_brelse(prev_bh); 802 affs_fix_checksum(sb, bh); 803 mark_buffer_dirty_inode(bh, inode); 804 written += tmp; 805 from += tmp; 806 bidx++; 807 } 808 SetPageUptodate(page); 809 810 done: 811 affs_brelse(bh); 812 tmp = (page->index << PAGE_SHIFT) + from; 813 if (tmp > inode->i_size) 814 inode->i_size = AFFS_I(inode)->mmu_private = tmp; 815 816 /* Clear Archived bit on file writes, as AmigaOS would do */ 817 if (AFFS_I(inode)->i_protect & FIBF_ARCHIVED) { 818 AFFS_I(inode)->i_protect &= ~FIBF_ARCHIVED; 819 mark_inode_dirty(inode); 820 } 821 822 err_first_bh: 823 unlock_page(page); 824 put_page(page); 825 826 return written; 827 828 err_bh: 829 bh = prev_bh; 830 if (!written) 831 written = PTR_ERR(bh); 832 goto done; 833 } 834 835 const struct address_space_operations affs_aops_ofs = { 836 .readpage = affs_readpage_ofs, 837 //.writepage = affs_writepage_ofs, 838 .write_begin = affs_write_begin_ofs, 839 .write_end = affs_write_end_ofs 840 }; 841 842 /* Free any preallocated blocks. */ 843 844 void 845 affs_free_prealloc(struct inode *inode) 846 { 847 struct super_block *sb = inode->i_sb; 848 849 pr_debug("free_prealloc(ino=%lu)\n", inode->i_ino); 850 851 while (AFFS_I(inode)->i_pa_cnt) { 852 AFFS_I(inode)->i_pa_cnt--; 853 affs_free_block(sb, ++AFFS_I(inode)->i_lastalloc); 854 } 855 } 856 857 /* Truncate (or enlarge) a file to the requested size. */ 858 859 void 860 affs_truncate(struct inode *inode) 861 { 862 struct super_block *sb = inode->i_sb; 863 u32 ext, ext_key; 864 u32 last_blk, blkcnt, blk; 865 u32 size; 866 struct buffer_head *ext_bh; 867 int i; 868 869 pr_debug("truncate(inode=%lu, oldsize=%llu, newsize=%llu)\n", 870 inode->i_ino, AFFS_I(inode)->mmu_private, inode->i_size); 871 872 last_blk = 0; 873 ext = 0; 874 if (inode->i_size) { 875 last_blk = ((u32)inode->i_size - 1) / AFFS_SB(sb)->s_data_blksize; 876 ext = last_blk / AFFS_SB(sb)->s_hashsize; 877 } 878 879 if (inode->i_size > AFFS_I(inode)->mmu_private) { 880 struct address_space *mapping = inode->i_mapping; 881 struct page *page; 882 void *fsdata; 883 loff_t isize = inode->i_size; 884 int res; 885 886 res = mapping->a_ops->write_begin(NULL, mapping, isize, 0, 0, &page, &fsdata); 887 if (!res) 888 res = mapping->a_ops->write_end(NULL, mapping, isize, 0, 0, page, fsdata); 889 else 890 inode->i_size = AFFS_I(inode)->mmu_private; 891 mark_inode_dirty(inode); 892 return; 893 } else if (inode->i_size == AFFS_I(inode)->mmu_private) 894 return; 895 896 // lock cache 897 ext_bh = affs_get_extblock(inode, ext); 898 if (IS_ERR(ext_bh)) { 899 affs_warning(sb, "truncate", 900 "unexpected read error for ext block %u (%ld)", 901 ext, PTR_ERR(ext_bh)); 902 return; 903 } 904 if (AFFS_I(inode)->i_lc) { 905 /* clear linear cache */ 906 i = (ext + 1) >> AFFS_I(inode)->i_lc_shift; 907 if (AFFS_I(inode)->i_lc_size > i) { 908 AFFS_I(inode)->i_lc_size = i; 909 for (; i < AFFS_LC_SIZE; i++) 910 AFFS_I(inode)->i_lc[i] = 0; 911 } 912 /* clear associative cache */ 913 for (i = 0; i < AFFS_AC_SIZE; i++) 914 if (AFFS_I(inode)->i_ac[i].ext >= ext) 915 AFFS_I(inode)->i_ac[i].ext = 0; 916 } 917 ext_key = be32_to_cpu(AFFS_TAIL(sb, ext_bh)->extension); 918 919 blkcnt = AFFS_I(inode)->i_blkcnt; 920 i = 0; 921 blk = last_blk; 922 if (inode->i_size) { 923 i = last_blk % AFFS_SB(sb)->s_hashsize + 1; 924 blk++; 925 } else 926 AFFS_HEAD(ext_bh)->first_data = 0; 927 AFFS_HEAD(ext_bh)->block_count = cpu_to_be32(i); 928 size = AFFS_SB(sb)->s_hashsize; 929 if (size > blkcnt - blk + i) 930 size = blkcnt - blk + i; 931 for (; i < size; i++, blk++) { 932 affs_free_block(sb, be32_to_cpu(AFFS_BLOCK(sb, ext_bh, i))); 933 AFFS_BLOCK(sb, ext_bh, i) = 0; 934 } 935 AFFS_TAIL(sb, ext_bh)->extension = 0; 936 affs_fix_checksum(sb, ext_bh); 937 mark_buffer_dirty_inode(ext_bh, inode); 938 affs_brelse(ext_bh); 939 940 if (inode->i_size) { 941 AFFS_I(inode)->i_blkcnt = last_blk + 1; 942 AFFS_I(inode)->i_extcnt = ext + 1; 943 if (affs_test_opt(AFFS_SB(sb)->s_flags, SF_OFS)) { 944 struct buffer_head *bh = affs_bread_ino(inode, last_blk, 0); 945 u32 tmp; 946 if (IS_ERR(bh)) { 947 affs_warning(sb, "truncate", 948 "unexpected read error for last block %u (%ld)", 949 ext, PTR_ERR(bh)); 950 return; 951 } 952 tmp = be32_to_cpu(AFFS_DATA_HEAD(bh)->next); 953 AFFS_DATA_HEAD(bh)->next = 0; 954 affs_adjust_checksum(bh, -tmp); 955 affs_brelse(bh); 956 } 957 } else { 958 AFFS_I(inode)->i_blkcnt = 0; 959 AFFS_I(inode)->i_extcnt = 1; 960 } 961 AFFS_I(inode)->mmu_private = inode->i_size; 962 // unlock cache 963 964 while (ext_key) { 965 ext_bh = affs_bread(sb, ext_key); 966 size = AFFS_SB(sb)->s_hashsize; 967 if (size > blkcnt - blk) 968 size = blkcnt - blk; 969 for (i = 0; i < size; i++, blk++) 970 affs_free_block(sb, be32_to_cpu(AFFS_BLOCK(sb, ext_bh, i))); 971 affs_free_block(sb, ext_key); 972 ext_key = be32_to_cpu(AFFS_TAIL(sb, ext_bh)->extension); 973 affs_brelse(ext_bh); 974 } 975 affs_free_prealloc(inode); 976 } 977 978 int affs_file_fsync(struct file *filp, loff_t start, loff_t end, int datasync) 979 { 980 struct inode *inode = filp->f_mapping->host; 981 int ret, err; 982 983 err = file_write_and_wait_range(filp, start, end); 984 if (err) 985 return err; 986 987 inode_lock(inode); 988 ret = write_inode_now(inode, 0); 989 err = sync_blockdev(inode->i_sb->s_bdev); 990 if (!ret) 991 ret = err; 992 inode_unlock(inode); 993 return ret; 994 } 995 const struct file_operations affs_file_operations = { 996 .llseek = generic_file_llseek, 997 .read_iter = generic_file_read_iter, 998 .write_iter = generic_file_write_iter, 999 .mmap = generic_file_mmap, 1000 .open = affs_file_open, 1001 .release = affs_file_release, 1002 .fsync = affs_file_fsync, 1003 .splice_read = generic_file_splice_read, 1004 }; 1005 1006 const struct inode_operations affs_file_inode_operations = { 1007 .setattr = affs_notify_change, 1008 }; 1009