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 sector_t _affs_bmap(struct address_space *mapping, sector_t block) 433 { 434 return generic_block_bmap(mapping,block,affs_get_block); 435 } 436 437 const struct address_space_operations affs_aops = { 438 .readpage = affs_readpage, 439 .writepage = affs_writepage, 440 .write_begin = affs_write_begin, 441 .write_end = generic_write_end, 442 .direct_IO = affs_direct_IO, 443 .bmap = _affs_bmap 444 }; 445 446 static inline struct buffer_head * 447 affs_bread_ino(struct inode *inode, int block, int create) 448 { 449 struct buffer_head *bh, tmp_bh; 450 int err; 451 452 tmp_bh.b_state = 0; 453 err = affs_get_block(inode, block, &tmp_bh, create); 454 if (!err) { 455 bh = affs_bread(inode->i_sb, tmp_bh.b_blocknr); 456 if (bh) { 457 bh->b_state |= tmp_bh.b_state; 458 return bh; 459 } 460 err = -EIO; 461 } 462 return ERR_PTR(err); 463 } 464 465 static inline struct buffer_head * 466 affs_getzeroblk_ino(struct inode *inode, int block) 467 { 468 struct buffer_head *bh, tmp_bh; 469 int err; 470 471 tmp_bh.b_state = 0; 472 err = affs_get_block(inode, block, &tmp_bh, 1); 473 if (!err) { 474 bh = affs_getzeroblk(inode->i_sb, tmp_bh.b_blocknr); 475 if (bh) { 476 bh->b_state |= tmp_bh.b_state; 477 return bh; 478 } 479 err = -EIO; 480 } 481 return ERR_PTR(err); 482 } 483 484 static inline struct buffer_head * 485 affs_getemptyblk_ino(struct inode *inode, int block) 486 { 487 struct buffer_head *bh, tmp_bh; 488 int err; 489 490 tmp_bh.b_state = 0; 491 err = affs_get_block(inode, block, &tmp_bh, 1); 492 if (!err) { 493 bh = affs_getemptyblk(inode->i_sb, tmp_bh.b_blocknr); 494 if (bh) { 495 bh->b_state |= tmp_bh.b_state; 496 return bh; 497 } 498 err = -EIO; 499 } 500 return ERR_PTR(err); 501 } 502 503 static int 504 affs_do_readpage_ofs(struct page *page, unsigned to, int create) 505 { 506 struct inode *inode = page->mapping->host; 507 struct super_block *sb = inode->i_sb; 508 struct buffer_head *bh; 509 char *data; 510 unsigned pos = 0; 511 u32 bidx, boff, bsize; 512 u32 tmp; 513 514 pr_debug("%s(%lu, %ld, 0, %d)\n", __func__, inode->i_ino, 515 page->index, to); 516 BUG_ON(to > PAGE_SIZE); 517 bsize = AFFS_SB(sb)->s_data_blksize; 518 tmp = page->index << PAGE_SHIFT; 519 bidx = tmp / bsize; 520 boff = tmp % bsize; 521 522 while (pos < to) { 523 bh = affs_bread_ino(inode, bidx, create); 524 if (IS_ERR(bh)) 525 return PTR_ERR(bh); 526 tmp = min(bsize - boff, to - pos); 527 BUG_ON(pos + tmp > to || tmp > bsize); 528 data = kmap_atomic(page); 529 memcpy(data + pos, AFFS_DATA(bh) + boff, tmp); 530 kunmap_atomic(data); 531 affs_brelse(bh); 532 bidx++; 533 pos += tmp; 534 boff = 0; 535 } 536 flush_dcache_page(page); 537 return 0; 538 } 539 540 static int 541 affs_extent_file_ofs(struct inode *inode, u32 newsize) 542 { 543 struct super_block *sb = inode->i_sb; 544 struct buffer_head *bh, *prev_bh; 545 u32 bidx, boff; 546 u32 size, bsize; 547 u32 tmp; 548 549 pr_debug("%s(%lu, %d)\n", __func__, inode->i_ino, newsize); 550 bsize = AFFS_SB(sb)->s_data_blksize; 551 bh = NULL; 552 size = AFFS_I(inode)->mmu_private; 553 bidx = size / bsize; 554 boff = size % bsize; 555 if (boff) { 556 bh = affs_bread_ino(inode, bidx, 0); 557 if (IS_ERR(bh)) 558 return PTR_ERR(bh); 559 tmp = min(bsize - boff, newsize - size); 560 BUG_ON(boff + tmp > bsize || tmp > bsize); 561 memset(AFFS_DATA(bh) + boff, 0, tmp); 562 be32_add_cpu(&AFFS_DATA_HEAD(bh)->size, tmp); 563 affs_fix_checksum(sb, bh); 564 mark_buffer_dirty_inode(bh, inode); 565 size += tmp; 566 bidx++; 567 } else if (bidx) { 568 bh = affs_bread_ino(inode, bidx - 1, 0); 569 if (IS_ERR(bh)) 570 return PTR_ERR(bh); 571 } 572 573 while (size < newsize) { 574 prev_bh = bh; 575 bh = affs_getzeroblk_ino(inode, bidx); 576 if (IS_ERR(bh)) 577 goto out; 578 tmp = min(bsize, newsize - size); 579 BUG_ON(tmp > bsize); 580 AFFS_DATA_HEAD(bh)->ptype = cpu_to_be32(T_DATA); 581 AFFS_DATA_HEAD(bh)->key = cpu_to_be32(inode->i_ino); 582 AFFS_DATA_HEAD(bh)->sequence = cpu_to_be32(bidx); 583 AFFS_DATA_HEAD(bh)->size = cpu_to_be32(tmp); 584 affs_fix_checksum(sb, bh); 585 bh->b_state &= ~(1UL << BH_New); 586 mark_buffer_dirty_inode(bh, inode); 587 if (prev_bh) { 588 u32 tmp_next = be32_to_cpu(AFFS_DATA_HEAD(prev_bh)->next); 589 590 if (tmp_next) 591 affs_warning(sb, "extent_file_ofs", 592 "next block already set for %d (%d)", 593 bidx, tmp_next); 594 AFFS_DATA_HEAD(prev_bh)->next = cpu_to_be32(bh->b_blocknr); 595 affs_adjust_checksum(prev_bh, bh->b_blocknr - tmp_next); 596 mark_buffer_dirty_inode(prev_bh, inode); 597 affs_brelse(prev_bh); 598 } 599 size += bsize; 600 bidx++; 601 } 602 affs_brelse(bh); 603 inode->i_size = AFFS_I(inode)->mmu_private = newsize; 604 return 0; 605 606 out: 607 inode->i_size = AFFS_I(inode)->mmu_private = newsize; 608 return PTR_ERR(bh); 609 } 610 611 static int 612 affs_readpage_ofs(struct file *file, struct page *page) 613 { 614 struct inode *inode = page->mapping->host; 615 u32 to; 616 int err; 617 618 pr_debug("%s(%lu, %ld)\n", __func__, inode->i_ino, page->index); 619 to = PAGE_SIZE; 620 if (((page->index + 1) << PAGE_SHIFT) > inode->i_size) { 621 to = inode->i_size & ~PAGE_MASK; 622 memset(page_address(page) + to, 0, PAGE_SIZE - to); 623 } 624 625 err = affs_do_readpage_ofs(page, to, 0); 626 if (!err) 627 SetPageUptodate(page); 628 unlock_page(page); 629 return err; 630 } 631 632 static int affs_write_begin_ofs(struct file *file, struct address_space *mapping, 633 loff_t pos, unsigned len, unsigned flags, 634 struct page **pagep, void **fsdata) 635 { 636 struct inode *inode = mapping->host; 637 struct page *page; 638 pgoff_t index; 639 int err = 0; 640 641 pr_debug("%s(%lu, %llu, %llu)\n", __func__, inode->i_ino, pos, 642 pos + len); 643 if (pos > AFFS_I(inode)->mmu_private) { 644 /* XXX: this probably leaves a too-big i_size in case of 645 * failure. Should really be updating i_size at write_end time 646 */ 647 err = affs_extent_file_ofs(inode, pos); 648 if (err) 649 return err; 650 } 651 652 index = pos >> PAGE_SHIFT; 653 page = grab_cache_page_write_begin(mapping, index, flags); 654 if (!page) 655 return -ENOMEM; 656 *pagep = page; 657 658 if (PageUptodate(page)) 659 return 0; 660 661 /* XXX: inefficient but safe in the face of short writes */ 662 err = affs_do_readpage_ofs(page, PAGE_SIZE, 1); 663 if (err) { 664 unlock_page(page); 665 put_page(page); 666 } 667 return err; 668 } 669 670 static int affs_write_end_ofs(struct file *file, struct address_space *mapping, 671 loff_t pos, unsigned len, unsigned copied, 672 struct page *page, void *fsdata) 673 { 674 struct inode *inode = mapping->host; 675 struct super_block *sb = inode->i_sb; 676 struct buffer_head *bh, *prev_bh; 677 char *data; 678 u32 bidx, boff, bsize; 679 unsigned from, to; 680 u32 tmp; 681 int written; 682 683 from = pos & (PAGE_SIZE - 1); 684 to = from + len; 685 /* 686 * XXX: not sure if this can handle short copies (len < copied), but 687 * we don't have to, because the page should always be uptodate here, 688 * due to write_begin. 689 */ 690 691 pr_debug("%s(%lu, %llu, %llu)\n", __func__, inode->i_ino, pos, 692 pos + len); 693 bsize = AFFS_SB(sb)->s_data_blksize; 694 data = page_address(page); 695 696 bh = NULL; 697 written = 0; 698 tmp = (page->index << PAGE_SHIFT) + from; 699 bidx = tmp / bsize; 700 boff = tmp % bsize; 701 if (boff) { 702 bh = affs_bread_ino(inode, bidx, 0); 703 if (IS_ERR(bh)) { 704 written = PTR_ERR(bh); 705 goto err_first_bh; 706 } 707 tmp = min(bsize - boff, to - from); 708 BUG_ON(boff + tmp > bsize || tmp > bsize); 709 memcpy(AFFS_DATA(bh) + boff, data + from, tmp); 710 be32_add_cpu(&AFFS_DATA_HEAD(bh)->size, tmp); 711 affs_fix_checksum(sb, bh); 712 mark_buffer_dirty_inode(bh, inode); 713 written += tmp; 714 from += tmp; 715 bidx++; 716 } else if (bidx) { 717 bh = affs_bread_ino(inode, bidx - 1, 0); 718 if (IS_ERR(bh)) { 719 written = PTR_ERR(bh); 720 goto err_first_bh; 721 } 722 } 723 while (from + bsize <= to) { 724 prev_bh = bh; 725 bh = affs_getemptyblk_ino(inode, bidx); 726 if (IS_ERR(bh)) 727 goto err_bh; 728 memcpy(AFFS_DATA(bh), data + from, bsize); 729 if (buffer_new(bh)) { 730 AFFS_DATA_HEAD(bh)->ptype = cpu_to_be32(T_DATA); 731 AFFS_DATA_HEAD(bh)->key = cpu_to_be32(inode->i_ino); 732 AFFS_DATA_HEAD(bh)->sequence = cpu_to_be32(bidx); 733 AFFS_DATA_HEAD(bh)->size = cpu_to_be32(bsize); 734 AFFS_DATA_HEAD(bh)->next = 0; 735 bh->b_state &= ~(1UL << BH_New); 736 if (prev_bh) { 737 u32 tmp_next = be32_to_cpu(AFFS_DATA_HEAD(prev_bh)->next); 738 739 if (tmp_next) 740 affs_warning(sb, "commit_write_ofs", 741 "next block already set for %d (%d)", 742 bidx, tmp_next); 743 AFFS_DATA_HEAD(prev_bh)->next = cpu_to_be32(bh->b_blocknr); 744 affs_adjust_checksum(prev_bh, bh->b_blocknr - tmp_next); 745 mark_buffer_dirty_inode(prev_bh, inode); 746 } 747 } 748 affs_brelse(prev_bh); 749 affs_fix_checksum(sb, bh); 750 mark_buffer_dirty_inode(bh, inode); 751 written += bsize; 752 from += bsize; 753 bidx++; 754 } 755 if (from < to) { 756 prev_bh = bh; 757 bh = affs_bread_ino(inode, bidx, 1); 758 if (IS_ERR(bh)) 759 goto err_bh; 760 tmp = min(bsize, to - from); 761 BUG_ON(tmp > bsize); 762 memcpy(AFFS_DATA(bh), data + from, tmp); 763 if (buffer_new(bh)) { 764 AFFS_DATA_HEAD(bh)->ptype = cpu_to_be32(T_DATA); 765 AFFS_DATA_HEAD(bh)->key = cpu_to_be32(inode->i_ino); 766 AFFS_DATA_HEAD(bh)->sequence = cpu_to_be32(bidx); 767 AFFS_DATA_HEAD(bh)->size = cpu_to_be32(tmp); 768 AFFS_DATA_HEAD(bh)->next = 0; 769 bh->b_state &= ~(1UL << BH_New); 770 if (prev_bh) { 771 u32 tmp_next = be32_to_cpu(AFFS_DATA_HEAD(prev_bh)->next); 772 773 if (tmp_next) 774 affs_warning(sb, "commit_write_ofs", 775 "next block already set for %d (%d)", 776 bidx, tmp_next); 777 AFFS_DATA_HEAD(prev_bh)->next = cpu_to_be32(bh->b_blocknr); 778 affs_adjust_checksum(prev_bh, bh->b_blocknr - tmp_next); 779 mark_buffer_dirty_inode(prev_bh, inode); 780 } 781 } else if (be32_to_cpu(AFFS_DATA_HEAD(bh)->size) < tmp) 782 AFFS_DATA_HEAD(bh)->size = cpu_to_be32(tmp); 783 affs_brelse(prev_bh); 784 affs_fix_checksum(sb, bh); 785 mark_buffer_dirty_inode(bh, inode); 786 written += tmp; 787 from += tmp; 788 bidx++; 789 } 790 SetPageUptodate(page); 791 792 done: 793 affs_brelse(bh); 794 tmp = (page->index << PAGE_SHIFT) + from; 795 if (tmp > inode->i_size) 796 inode->i_size = AFFS_I(inode)->mmu_private = tmp; 797 798 err_first_bh: 799 unlock_page(page); 800 put_page(page); 801 802 return written; 803 804 err_bh: 805 bh = prev_bh; 806 if (!written) 807 written = PTR_ERR(bh); 808 goto done; 809 } 810 811 const struct address_space_operations affs_aops_ofs = { 812 .readpage = affs_readpage_ofs, 813 //.writepage = affs_writepage_ofs, 814 .write_begin = affs_write_begin_ofs, 815 .write_end = affs_write_end_ofs 816 }; 817 818 /* Free any preallocated blocks. */ 819 820 void 821 affs_free_prealloc(struct inode *inode) 822 { 823 struct super_block *sb = inode->i_sb; 824 825 pr_debug("free_prealloc(ino=%lu)\n", inode->i_ino); 826 827 while (AFFS_I(inode)->i_pa_cnt) { 828 AFFS_I(inode)->i_pa_cnt--; 829 affs_free_block(sb, ++AFFS_I(inode)->i_lastalloc); 830 } 831 } 832 833 /* Truncate (or enlarge) a file to the requested size. */ 834 835 void 836 affs_truncate(struct inode *inode) 837 { 838 struct super_block *sb = inode->i_sb; 839 u32 ext, ext_key; 840 u32 last_blk, blkcnt, blk; 841 u32 size; 842 struct buffer_head *ext_bh; 843 int i; 844 845 pr_debug("truncate(inode=%lu, oldsize=%llu, newsize=%llu)\n", 846 inode->i_ino, AFFS_I(inode)->mmu_private, inode->i_size); 847 848 last_blk = 0; 849 ext = 0; 850 if (inode->i_size) { 851 last_blk = ((u32)inode->i_size - 1) / AFFS_SB(sb)->s_data_blksize; 852 ext = last_blk / AFFS_SB(sb)->s_hashsize; 853 } 854 855 if (inode->i_size > AFFS_I(inode)->mmu_private) { 856 struct address_space *mapping = inode->i_mapping; 857 struct page *page; 858 void *fsdata; 859 loff_t isize = inode->i_size; 860 int res; 861 862 res = mapping->a_ops->write_begin(NULL, mapping, isize, 0, 0, &page, &fsdata); 863 if (!res) 864 res = mapping->a_ops->write_end(NULL, mapping, isize, 0, 0, page, fsdata); 865 else 866 inode->i_size = AFFS_I(inode)->mmu_private; 867 mark_inode_dirty(inode); 868 return; 869 } else if (inode->i_size == AFFS_I(inode)->mmu_private) 870 return; 871 872 // lock cache 873 ext_bh = affs_get_extblock(inode, ext); 874 if (IS_ERR(ext_bh)) { 875 affs_warning(sb, "truncate", 876 "unexpected read error for ext block %u (%ld)", 877 ext, PTR_ERR(ext_bh)); 878 return; 879 } 880 if (AFFS_I(inode)->i_lc) { 881 /* clear linear cache */ 882 i = (ext + 1) >> AFFS_I(inode)->i_lc_shift; 883 if (AFFS_I(inode)->i_lc_size > i) { 884 AFFS_I(inode)->i_lc_size = i; 885 for (; i < AFFS_LC_SIZE; i++) 886 AFFS_I(inode)->i_lc[i] = 0; 887 } 888 /* clear associative cache */ 889 for (i = 0; i < AFFS_AC_SIZE; i++) 890 if (AFFS_I(inode)->i_ac[i].ext >= ext) 891 AFFS_I(inode)->i_ac[i].ext = 0; 892 } 893 ext_key = be32_to_cpu(AFFS_TAIL(sb, ext_bh)->extension); 894 895 blkcnt = AFFS_I(inode)->i_blkcnt; 896 i = 0; 897 blk = last_blk; 898 if (inode->i_size) { 899 i = last_blk % AFFS_SB(sb)->s_hashsize + 1; 900 blk++; 901 } else 902 AFFS_HEAD(ext_bh)->first_data = 0; 903 AFFS_HEAD(ext_bh)->block_count = cpu_to_be32(i); 904 size = AFFS_SB(sb)->s_hashsize; 905 if (size > blkcnt - blk + i) 906 size = blkcnt - blk + i; 907 for (; i < size; i++, blk++) { 908 affs_free_block(sb, be32_to_cpu(AFFS_BLOCK(sb, ext_bh, i))); 909 AFFS_BLOCK(sb, ext_bh, i) = 0; 910 } 911 AFFS_TAIL(sb, ext_bh)->extension = 0; 912 affs_fix_checksum(sb, ext_bh); 913 mark_buffer_dirty_inode(ext_bh, inode); 914 affs_brelse(ext_bh); 915 916 if (inode->i_size) { 917 AFFS_I(inode)->i_blkcnt = last_blk + 1; 918 AFFS_I(inode)->i_extcnt = ext + 1; 919 if (affs_test_opt(AFFS_SB(sb)->s_flags, SF_OFS)) { 920 struct buffer_head *bh = affs_bread_ino(inode, last_blk, 0); 921 u32 tmp; 922 if (IS_ERR(bh)) { 923 affs_warning(sb, "truncate", 924 "unexpected read error for last block %u (%ld)", 925 ext, PTR_ERR(bh)); 926 return; 927 } 928 tmp = be32_to_cpu(AFFS_DATA_HEAD(bh)->next); 929 AFFS_DATA_HEAD(bh)->next = 0; 930 affs_adjust_checksum(bh, -tmp); 931 affs_brelse(bh); 932 } 933 } else { 934 AFFS_I(inode)->i_blkcnt = 0; 935 AFFS_I(inode)->i_extcnt = 1; 936 } 937 AFFS_I(inode)->mmu_private = inode->i_size; 938 // unlock cache 939 940 while (ext_key) { 941 ext_bh = affs_bread(sb, ext_key); 942 size = AFFS_SB(sb)->s_hashsize; 943 if (size > blkcnt - blk) 944 size = blkcnt - blk; 945 for (i = 0; i < size; i++, blk++) 946 affs_free_block(sb, be32_to_cpu(AFFS_BLOCK(sb, ext_bh, i))); 947 affs_free_block(sb, ext_key); 948 ext_key = be32_to_cpu(AFFS_TAIL(sb, ext_bh)->extension); 949 affs_brelse(ext_bh); 950 } 951 affs_free_prealloc(inode); 952 } 953 954 int affs_file_fsync(struct file *filp, loff_t start, loff_t end, int datasync) 955 { 956 struct inode *inode = filp->f_mapping->host; 957 int ret, err; 958 959 err = file_write_and_wait_range(filp, start, end); 960 if (err) 961 return err; 962 963 inode_lock(inode); 964 ret = write_inode_now(inode, 0); 965 err = sync_blockdev(inode->i_sb->s_bdev); 966 if (!ret) 967 ret = err; 968 inode_unlock(inode); 969 return ret; 970 } 971 const struct file_operations affs_file_operations = { 972 .llseek = generic_file_llseek, 973 .read_iter = generic_file_read_iter, 974 .write_iter = generic_file_write_iter, 975 .mmap = generic_file_mmap, 976 .open = affs_file_open, 977 .release = affs_file_release, 978 .fsync = affs_file_fsync, 979 .splice_read = generic_file_splice_read, 980 }; 981 982 const struct inode_operations affs_file_inode_operations = { 983 .setattr = affs_notify_change, 984 }; 985