Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * linux/fs/affs/file.c |
| 3 | * |
| 4 | * (c) 1996 Hans-Joachim Widmaier - Rewritten |
| 5 | * |
| 6 | * (C) 1993 Ray Burr - Modified for Amiga FFS filesystem. |
| 7 | * |
| 8 | * (C) 1992 Eric Youngdale Modified for ISO 9660 filesystem. |
| 9 | * |
| 10 | * (C) 1991 Linus Torvalds - minix filesystem |
| 11 | * |
| 12 | * affs regular file handling primitives |
| 13 | */ |
| 14 | |
| 15 | #include "affs.h" |
| 16 | |
| 17 | #if PAGE_SIZE < 4096 |
| 18 | #error PAGE_SIZE must be at least 4096 |
| 19 | #endif |
| 20 | |
| 21 | static int affs_grow_extcache(struct inode *inode, u32 lc_idx); |
| 22 | static struct buffer_head *affs_alloc_extblock(struct inode *inode, struct buffer_head *bh, u32 ext); |
| 23 | static inline struct buffer_head *affs_get_extblock(struct inode *inode, u32 ext); |
| 24 | static struct buffer_head *affs_get_extblock_slow(struct inode *inode, u32 ext); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 25 | static int affs_file_open(struct inode *inode, struct file *filp); |
| 26 | static int affs_file_release(struct inode *inode, struct file *filp); |
| 27 | |
Arjan van de Ven | 4b6f5d2 | 2006-03-28 01:56:42 -0800 | [diff] [blame] | 28 | const struct file_operations affs_file_operations = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 29 | .llseek = generic_file_llseek, |
Badari Pulavarty | 543ade1 | 2006-09-30 23:28:48 -0700 | [diff] [blame] | 30 | .read = do_sync_read, |
| 31 | .aio_read = generic_file_aio_read, |
| 32 | .write = do_sync_write, |
| 33 | .aio_write = generic_file_aio_write, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 34 | .mmap = generic_file_mmap, |
| 35 | .open = affs_file_open, |
| 36 | .release = affs_file_release, |
| 37 | .fsync = file_fsync, |
| 38 | .sendfile = generic_file_sendfile, |
| 39 | }; |
| 40 | |
Arjan van de Ven | 754661f | 2007-02-12 00:55:38 -0800 | [diff] [blame] | 41 | const struct inode_operations affs_file_inode_operations = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 42 | .truncate = affs_truncate, |
| 43 | .setattr = affs_notify_change, |
| 44 | }; |
| 45 | |
| 46 | static int |
| 47 | affs_file_open(struct inode *inode, struct file *filp) |
| 48 | { |
| 49 | if (atomic_read(&filp->f_count) != 1) |
| 50 | return 0; |
| 51 | pr_debug("AFFS: open(%d)\n", AFFS_I(inode)->i_opencnt); |
| 52 | AFFS_I(inode)->i_opencnt++; |
| 53 | return 0; |
| 54 | } |
| 55 | |
| 56 | static int |
| 57 | affs_file_release(struct inode *inode, struct file *filp) |
| 58 | { |
| 59 | if (atomic_read(&filp->f_count) != 0) |
| 60 | return 0; |
| 61 | pr_debug("AFFS: release(%d)\n", AFFS_I(inode)->i_opencnt); |
| 62 | AFFS_I(inode)->i_opencnt--; |
| 63 | if (!AFFS_I(inode)->i_opencnt) |
| 64 | affs_free_prealloc(inode); |
| 65 | |
| 66 | return 0; |
| 67 | } |
| 68 | |
| 69 | static int |
| 70 | affs_grow_extcache(struct inode *inode, u32 lc_idx) |
| 71 | { |
| 72 | struct super_block *sb = inode->i_sb; |
| 73 | struct buffer_head *bh; |
| 74 | u32 lc_max; |
| 75 | int i, j, key; |
| 76 | |
| 77 | if (!AFFS_I(inode)->i_lc) { |
| 78 | char *ptr = (char *)get_zeroed_page(GFP_NOFS); |
| 79 | if (!ptr) |
| 80 | return -ENOMEM; |
| 81 | AFFS_I(inode)->i_lc = (u32 *)ptr; |
| 82 | AFFS_I(inode)->i_ac = (struct affs_ext_key *)(ptr + AFFS_CACHE_SIZE / 2); |
| 83 | } |
| 84 | |
| 85 | lc_max = AFFS_LC_SIZE << AFFS_I(inode)->i_lc_shift; |
| 86 | |
| 87 | if (AFFS_I(inode)->i_extcnt > lc_max) { |
| 88 | u32 lc_shift, lc_mask, tmp, off; |
| 89 | |
| 90 | /* need to recalculate linear cache, start from old size */ |
| 91 | lc_shift = AFFS_I(inode)->i_lc_shift; |
| 92 | tmp = (AFFS_I(inode)->i_extcnt / AFFS_LC_SIZE) >> lc_shift; |
| 93 | for (; tmp; tmp >>= 1) |
| 94 | lc_shift++; |
| 95 | lc_mask = (1 << lc_shift) - 1; |
| 96 | |
| 97 | /* fix idx and old size to new shift */ |
| 98 | lc_idx >>= (lc_shift - AFFS_I(inode)->i_lc_shift); |
| 99 | AFFS_I(inode)->i_lc_size >>= (lc_shift - AFFS_I(inode)->i_lc_shift); |
| 100 | |
| 101 | /* first shrink old cache to make more space */ |
| 102 | off = 1 << (lc_shift - AFFS_I(inode)->i_lc_shift); |
| 103 | for (i = 1, j = off; j < AFFS_LC_SIZE; i++, j += off) |
| 104 | AFFS_I(inode)->i_ac[i] = AFFS_I(inode)->i_ac[j]; |
| 105 | |
| 106 | AFFS_I(inode)->i_lc_shift = lc_shift; |
| 107 | AFFS_I(inode)->i_lc_mask = lc_mask; |
| 108 | } |
| 109 | |
| 110 | /* fill cache to the needed index */ |
| 111 | i = AFFS_I(inode)->i_lc_size; |
| 112 | AFFS_I(inode)->i_lc_size = lc_idx + 1; |
| 113 | for (; i <= lc_idx; i++) { |
| 114 | if (!i) { |
| 115 | AFFS_I(inode)->i_lc[0] = inode->i_ino; |
| 116 | continue; |
| 117 | } |
| 118 | key = AFFS_I(inode)->i_lc[i - 1]; |
| 119 | j = AFFS_I(inode)->i_lc_mask + 1; |
| 120 | // unlock cache |
| 121 | for (; j > 0; j--) { |
| 122 | bh = affs_bread(sb, key); |
| 123 | if (!bh) |
| 124 | goto err; |
| 125 | key = be32_to_cpu(AFFS_TAIL(sb, bh)->extension); |
| 126 | affs_brelse(bh); |
| 127 | } |
| 128 | // lock cache |
| 129 | AFFS_I(inode)->i_lc[i] = key; |
| 130 | } |
| 131 | |
| 132 | return 0; |
| 133 | |
| 134 | err: |
| 135 | // lock cache |
| 136 | return -EIO; |
| 137 | } |
| 138 | |
| 139 | static struct buffer_head * |
| 140 | affs_alloc_extblock(struct inode *inode, struct buffer_head *bh, u32 ext) |
| 141 | { |
| 142 | struct super_block *sb = inode->i_sb; |
| 143 | struct buffer_head *new_bh; |
| 144 | u32 blocknr, tmp; |
| 145 | |
| 146 | blocknr = affs_alloc_block(inode, bh->b_blocknr); |
| 147 | if (!blocknr) |
| 148 | return ERR_PTR(-ENOSPC); |
| 149 | |
| 150 | new_bh = affs_getzeroblk(sb, blocknr); |
| 151 | if (!new_bh) { |
| 152 | affs_free_block(sb, blocknr); |
| 153 | return ERR_PTR(-EIO); |
| 154 | } |
| 155 | |
| 156 | AFFS_HEAD(new_bh)->ptype = cpu_to_be32(T_LIST); |
| 157 | AFFS_HEAD(new_bh)->key = cpu_to_be32(blocknr); |
| 158 | AFFS_TAIL(sb, new_bh)->stype = cpu_to_be32(ST_FILE); |
| 159 | AFFS_TAIL(sb, new_bh)->parent = cpu_to_be32(inode->i_ino); |
| 160 | affs_fix_checksum(sb, new_bh); |
| 161 | |
| 162 | mark_buffer_dirty_inode(new_bh, inode); |
| 163 | |
| 164 | tmp = be32_to_cpu(AFFS_TAIL(sb, bh)->extension); |
| 165 | if (tmp) |
| 166 | affs_warning(sb, "alloc_ext", "previous extension set (%x)", tmp); |
| 167 | AFFS_TAIL(sb, bh)->extension = cpu_to_be32(blocknr); |
| 168 | affs_adjust_checksum(bh, blocknr - tmp); |
| 169 | mark_buffer_dirty_inode(bh, inode); |
| 170 | |
| 171 | AFFS_I(inode)->i_extcnt++; |
| 172 | mark_inode_dirty(inode); |
| 173 | |
| 174 | return new_bh; |
| 175 | } |
| 176 | |
| 177 | static inline struct buffer_head * |
| 178 | affs_get_extblock(struct inode *inode, u32 ext) |
| 179 | { |
| 180 | /* inline the simplest case: same extended block as last time */ |
| 181 | struct buffer_head *bh = AFFS_I(inode)->i_ext_bh; |
| 182 | if (ext == AFFS_I(inode)->i_ext_last) |
| 183 | atomic_inc(&bh->b_count); |
| 184 | else |
| 185 | /* we have to do more (not inlined) */ |
| 186 | bh = affs_get_extblock_slow(inode, ext); |
| 187 | |
| 188 | return bh; |
| 189 | } |
| 190 | |
| 191 | static struct buffer_head * |
| 192 | affs_get_extblock_slow(struct inode *inode, u32 ext) |
| 193 | { |
| 194 | struct super_block *sb = inode->i_sb; |
| 195 | struct buffer_head *bh; |
| 196 | u32 ext_key; |
| 197 | u32 lc_idx, lc_off, ac_idx; |
| 198 | u32 tmp, idx; |
| 199 | |
| 200 | if (ext == AFFS_I(inode)->i_ext_last + 1) { |
| 201 | /* read the next extended block from the current one */ |
| 202 | bh = AFFS_I(inode)->i_ext_bh; |
| 203 | ext_key = be32_to_cpu(AFFS_TAIL(sb, bh)->extension); |
| 204 | if (ext < AFFS_I(inode)->i_extcnt) |
| 205 | goto read_ext; |
| 206 | if (ext > AFFS_I(inode)->i_extcnt) |
| 207 | BUG(); |
| 208 | bh = affs_alloc_extblock(inode, bh, ext); |
| 209 | if (IS_ERR(bh)) |
| 210 | return bh; |
| 211 | goto store_ext; |
| 212 | } |
| 213 | |
| 214 | if (ext == 0) { |
| 215 | /* we seek back to the file header block */ |
| 216 | ext_key = inode->i_ino; |
| 217 | goto read_ext; |
| 218 | } |
| 219 | |
| 220 | if (ext >= AFFS_I(inode)->i_extcnt) { |
| 221 | struct buffer_head *prev_bh; |
| 222 | |
| 223 | /* allocate a new extended block */ |
| 224 | if (ext > AFFS_I(inode)->i_extcnt) |
| 225 | BUG(); |
| 226 | |
| 227 | /* get previous extended block */ |
| 228 | prev_bh = affs_get_extblock(inode, ext - 1); |
| 229 | if (IS_ERR(prev_bh)) |
| 230 | return prev_bh; |
| 231 | bh = affs_alloc_extblock(inode, prev_bh, ext); |
| 232 | affs_brelse(prev_bh); |
| 233 | if (IS_ERR(bh)) |
| 234 | return bh; |
| 235 | goto store_ext; |
| 236 | } |
| 237 | |
| 238 | again: |
| 239 | /* check if there is an extended cache and whether it's large enough */ |
| 240 | lc_idx = ext >> AFFS_I(inode)->i_lc_shift; |
| 241 | lc_off = ext & AFFS_I(inode)->i_lc_mask; |
| 242 | |
| 243 | if (lc_idx >= AFFS_I(inode)->i_lc_size) { |
| 244 | int err; |
| 245 | |
| 246 | err = affs_grow_extcache(inode, lc_idx); |
| 247 | if (err) |
| 248 | return ERR_PTR(err); |
| 249 | goto again; |
| 250 | } |
| 251 | |
| 252 | /* every n'th key we find in the linear cache */ |
| 253 | if (!lc_off) { |
| 254 | ext_key = AFFS_I(inode)->i_lc[lc_idx]; |
| 255 | goto read_ext; |
| 256 | } |
| 257 | |
| 258 | /* maybe it's still in the associative cache */ |
| 259 | ac_idx = (ext - lc_idx - 1) & AFFS_AC_MASK; |
| 260 | if (AFFS_I(inode)->i_ac[ac_idx].ext == ext) { |
| 261 | ext_key = AFFS_I(inode)->i_ac[ac_idx].key; |
| 262 | goto read_ext; |
| 263 | } |
| 264 | |
| 265 | /* try to find one of the previous extended blocks */ |
| 266 | tmp = ext; |
| 267 | idx = ac_idx; |
| 268 | while (--tmp, --lc_off > 0) { |
| 269 | idx = (idx - 1) & AFFS_AC_MASK; |
| 270 | if (AFFS_I(inode)->i_ac[idx].ext == tmp) { |
| 271 | ext_key = AFFS_I(inode)->i_ac[idx].key; |
| 272 | goto find_ext; |
| 273 | } |
| 274 | } |
| 275 | |
| 276 | /* fall back to the linear cache */ |
| 277 | ext_key = AFFS_I(inode)->i_lc[lc_idx]; |
| 278 | find_ext: |
| 279 | /* read all extended blocks until we find the one we need */ |
| 280 | //unlock cache |
| 281 | do { |
| 282 | bh = affs_bread(sb, ext_key); |
| 283 | if (!bh) |
| 284 | goto err_bread; |
| 285 | ext_key = be32_to_cpu(AFFS_TAIL(sb, bh)->extension); |
| 286 | affs_brelse(bh); |
| 287 | tmp++; |
| 288 | } while (tmp < ext); |
| 289 | //lock cache |
| 290 | |
| 291 | /* store it in the associative cache */ |
| 292 | // recalculate ac_idx? |
| 293 | AFFS_I(inode)->i_ac[ac_idx].ext = ext; |
| 294 | AFFS_I(inode)->i_ac[ac_idx].key = ext_key; |
| 295 | |
| 296 | read_ext: |
| 297 | /* finally read the right extended block */ |
| 298 | //unlock cache |
| 299 | bh = affs_bread(sb, ext_key); |
| 300 | if (!bh) |
| 301 | goto err_bread; |
| 302 | //lock cache |
| 303 | |
| 304 | store_ext: |
| 305 | /* release old cached extended block and store the new one */ |
| 306 | affs_brelse(AFFS_I(inode)->i_ext_bh); |
| 307 | AFFS_I(inode)->i_ext_last = ext; |
| 308 | AFFS_I(inode)->i_ext_bh = bh; |
| 309 | atomic_inc(&bh->b_count); |
| 310 | |
| 311 | return bh; |
| 312 | |
| 313 | err_bread: |
| 314 | affs_brelse(bh); |
| 315 | return ERR_PTR(-EIO); |
| 316 | } |
| 317 | |
| 318 | static int |
| 319 | affs_get_block(struct inode *inode, sector_t block, struct buffer_head *bh_result, int create) |
| 320 | { |
| 321 | struct super_block *sb = inode->i_sb; |
| 322 | struct buffer_head *ext_bh; |
| 323 | u32 ext; |
| 324 | |
| 325 | pr_debug("AFFS: get_block(%u, %lu)\n", (u32)inode->i_ino, (unsigned long)block); |
| 326 | |
| 327 | |
| 328 | if (block > (sector_t)0x7fffffffUL) |
| 329 | BUG(); |
| 330 | |
| 331 | if (block >= AFFS_I(inode)->i_blkcnt) { |
| 332 | if (block > AFFS_I(inode)->i_blkcnt || !create) |
| 333 | goto err_big; |
| 334 | } else |
| 335 | create = 0; |
| 336 | |
| 337 | //lock cache |
| 338 | affs_lock_ext(inode); |
| 339 | |
| 340 | ext = (u32)block / AFFS_SB(sb)->s_hashsize; |
| 341 | block -= ext * AFFS_SB(sb)->s_hashsize; |
| 342 | ext_bh = affs_get_extblock(inode, ext); |
| 343 | if (IS_ERR(ext_bh)) |
| 344 | goto err_ext; |
| 345 | map_bh(bh_result, sb, (sector_t)be32_to_cpu(AFFS_BLOCK(sb, ext_bh, block))); |
| 346 | |
| 347 | if (create) { |
| 348 | u32 blocknr = affs_alloc_block(inode, ext_bh->b_blocknr); |
| 349 | if (!blocknr) |
| 350 | goto err_alloc; |
| 351 | set_buffer_new(bh_result); |
| 352 | AFFS_I(inode)->mmu_private += AFFS_SB(sb)->s_data_blksize; |
| 353 | AFFS_I(inode)->i_blkcnt++; |
| 354 | |
| 355 | /* store new block */ |
| 356 | if (bh_result->b_blocknr) |
| 357 | affs_warning(sb, "get_block", "block already set (%x)", bh_result->b_blocknr); |
| 358 | AFFS_BLOCK(sb, ext_bh, block) = cpu_to_be32(blocknr); |
| 359 | AFFS_HEAD(ext_bh)->block_count = cpu_to_be32(block + 1); |
| 360 | affs_adjust_checksum(ext_bh, blocknr - bh_result->b_blocknr + 1); |
| 361 | bh_result->b_blocknr = blocknr; |
| 362 | |
| 363 | if (!block) { |
| 364 | /* insert first block into header block */ |
| 365 | u32 tmp = be32_to_cpu(AFFS_HEAD(ext_bh)->first_data); |
| 366 | if (tmp) |
| 367 | affs_warning(sb, "get_block", "first block already set (%d)", tmp); |
| 368 | AFFS_HEAD(ext_bh)->first_data = cpu_to_be32(blocknr); |
| 369 | affs_adjust_checksum(ext_bh, blocknr - tmp); |
| 370 | } |
| 371 | } |
| 372 | |
| 373 | affs_brelse(ext_bh); |
| 374 | //unlock cache |
| 375 | affs_unlock_ext(inode); |
| 376 | return 0; |
| 377 | |
| 378 | err_big: |
| 379 | affs_error(inode->i_sb,"get_block","strange block request %d", block); |
| 380 | return -EIO; |
| 381 | err_ext: |
| 382 | // unlock cache |
| 383 | affs_unlock_ext(inode); |
| 384 | return PTR_ERR(ext_bh); |
| 385 | err_alloc: |
| 386 | brelse(ext_bh); |
| 387 | clear_buffer_mapped(bh_result); |
| 388 | bh_result->b_bdev = NULL; |
| 389 | // unlock cache |
| 390 | affs_unlock_ext(inode); |
| 391 | return -ENOSPC; |
| 392 | } |
| 393 | |
| 394 | static int affs_writepage(struct page *page, struct writeback_control *wbc) |
| 395 | { |
| 396 | return block_write_full_page(page, affs_get_block, wbc); |
| 397 | } |
| 398 | static int affs_readpage(struct file *file, struct page *page) |
| 399 | { |
| 400 | return block_read_full_page(page, affs_get_block); |
| 401 | } |
| 402 | static int affs_prepare_write(struct file *file, struct page *page, unsigned from, unsigned to) |
| 403 | { |
| 404 | return cont_prepare_write(page, from, to, affs_get_block, |
| 405 | &AFFS_I(page->mapping->host)->mmu_private); |
| 406 | } |
| 407 | static sector_t _affs_bmap(struct address_space *mapping, sector_t block) |
| 408 | { |
| 409 | return generic_block_bmap(mapping,block,affs_get_block); |
| 410 | } |
Christoph Hellwig | f5e54d6 | 2006-06-28 04:26:44 -0700 | [diff] [blame] | 411 | const struct address_space_operations affs_aops = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 412 | .readpage = affs_readpage, |
| 413 | .writepage = affs_writepage, |
| 414 | .sync_page = block_sync_page, |
| 415 | .prepare_write = affs_prepare_write, |
| 416 | .commit_write = generic_commit_write, |
| 417 | .bmap = _affs_bmap |
| 418 | }; |
| 419 | |
| 420 | static inline struct buffer_head * |
| 421 | affs_bread_ino(struct inode *inode, int block, int create) |
| 422 | { |
| 423 | struct buffer_head *bh, tmp_bh; |
| 424 | int err; |
| 425 | |
| 426 | tmp_bh.b_state = 0; |
| 427 | err = affs_get_block(inode, block, &tmp_bh, create); |
| 428 | if (!err) { |
| 429 | bh = affs_bread(inode->i_sb, tmp_bh.b_blocknr); |
| 430 | if (bh) { |
| 431 | bh->b_state |= tmp_bh.b_state; |
| 432 | return bh; |
| 433 | } |
| 434 | err = -EIO; |
| 435 | } |
| 436 | return ERR_PTR(err); |
| 437 | } |
| 438 | |
| 439 | static inline struct buffer_head * |
| 440 | affs_getzeroblk_ino(struct inode *inode, int block) |
| 441 | { |
| 442 | struct buffer_head *bh, tmp_bh; |
| 443 | int err; |
| 444 | |
| 445 | tmp_bh.b_state = 0; |
| 446 | err = affs_get_block(inode, block, &tmp_bh, 1); |
| 447 | if (!err) { |
| 448 | bh = affs_getzeroblk(inode->i_sb, tmp_bh.b_blocknr); |
| 449 | if (bh) { |
| 450 | bh->b_state |= tmp_bh.b_state; |
| 451 | return bh; |
| 452 | } |
| 453 | err = -EIO; |
| 454 | } |
| 455 | return ERR_PTR(err); |
| 456 | } |
| 457 | |
| 458 | static inline struct buffer_head * |
| 459 | affs_getemptyblk_ino(struct inode *inode, int block) |
| 460 | { |
| 461 | struct buffer_head *bh, tmp_bh; |
| 462 | int err; |
| 463 | |
| 464 | tmp_bh.b_state = 0; |
| 465 | err = affs_get_block(inode, block, &tmp_bh, 1); |
| 466 | if (!err) { |
| 467 | bh = affs_getemptyblk(inode->i_sb, tmp_bh.b_blocknr); |
| 468 | if (bh) { |
| 469 | bh->b_state |= tmp_bh.b_state; |
| 470 | return bh; |
| 471 | } |
| 472 | err = -EIO; |
| 473 | } |
| 474 | return ERR_PTR(err); |
| 475 | } |
| 476 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 477 | static int |
| 478 | affs_do_readpage_ofs(struct file *file, struct page *page, unsigned from, unsigned to) |
| 479 | { |
| 480 | struct inode *inode = page->mapping->host; |
| 481 | struct super_block *sb = inode->i_sb; |
| 482 | struct buffer_head *bh; |
| 483 | char *data; |
| 484 | u32 bidx, boff, bsize; |
| 485 | u32 tmp; |
| 486 | |
| 487 | pr_debug("AFFS: read_page(%u, %ld, %d, %d)\n", (u32)inode->i_ino, page->index, from, to); |
| 488 | if (from > to || to > PAGE_CACHE_SIZE) |
| 489 | BUG(); |
| 490 | kmap(page); |
| 491 | data = page_address(page); |
| 492 | bsize = AFFS_SB(sb)->s_data_blksize; |
| 493 | tmp = (page->index << PAGE_CACHE_SHIFT) + from; |
| 494 | bidx = tmp / bsize; |
| 495 | boff = tmp % bsize; |
| 496 | |
| 497 | while (from < to) { |
| 498 | bh = affs_bread_ino(inode, bidx, 0); |
| 499 | if (IS_ERR(bh)) |
| 500 | return PTR_ERR(bh); |
| 501 | tmp = min(bsize - boff, to - from); |
| 502 | if (from + tmp > to || tmp > bsize) |
| 503 | BUG(); |
| 504 | memcpy(data + from, AFFS_DATA(bh) + boff, tmp); |
| 505 | affs_brelse(bh); |
| 506 | bidx++; |
| 507 | from += tmp; |
| 508 | boff = 0; |
| 509 | } |
| 510 | flush_dcache_page(page); |
| 511 | kunmap(page); |
| 512 | return 0; |
| 513 | } |
| 514 | |
| 515 | static int |
| 516 | affs_extent_file_ofs(struct inode *inode, u32 newsize) |
| 517 | { |
| 518 | struct super_block *sb = inode->i_sb; |
| 519 | struct buffer_head *bh, *prev_bh; |
| 520 | u32 bidx, boff; |
| 521 | u32 size, bsize; |
| 522 | u32 tmp; |
| 523 | |
| 524 | pr_debug("AFFS: extent_file(%u, %d)\n", (u32)inode->i_ino, newsize); |
| 525 | bsize = AFFS_SB(sb)->s_data_blksize; |
| 526 | bh = NULL; |
| 527 | size = AFFS_I(inode)->mmu_private; |
| 528 | bidx = size / bsize; |
| 529 | boff = size % bsize; |
| 530 | if (boff) { |
| 531 | bh = affs_bread_ino(inode, bidx, 0); |
| 532 | if (IS_ERR(bh)) |
| 533 | return PTR_ERR(bh); |
| 534 | tmp = min(bsize - boff, newsize - size); |
| 535 | if (boff + tmp > bsize || tmp > bsize) |
| 536 | BUG(); |
| 537 | memset(AFFS_DATA(bh) + boff, 0, tmp); |
| 538 | AFFS_DATA_HEAD(bh)->size = cpu_to_be32(be32_to_cpu(AFFS_DATA_HEAD(bh)->size) + tmp); |
| 539 | affs_fix_checksum(sb, bh); |
| 540 | mark_buffer_dirty_inode(bh, inode); |
| 541 | size += tmp; |
| 542 | bidx++; |
| 543 | } else if (bidx) { |
| 544 | bh = affs_bread_ino(inode, bidx - 1, 0); |
| 545 | if (IS_ERR(bh)) |
| 546 | return PTR_ERR(bh); |
| 547 | } |
| 548 | |
| 549 | while (size < newsize) { |
| 550 | prev_bh = bh; |
| 551 | bh = affs_getzeroblk_ino(inode, bidx); |
| 552 | if (IS_ERR(bh)) |
| 553 | goto out; |
| 554 | tmp = min(bsize, newsize - size); |
| 555 | if (tmp > bsize) |
| 556 | BUG(); |
| 557 | AFFS_DATA_HEAD(bh)->ptype = cpu_to_be32(T_DATA); |
| 558 | AFFS_DATA_HEAD(bh)->key = cpu_to_be32(inode->i_ino); |
| 559 | AFFS_DATA_HEAD(bh)->sequence = cpu_to_be32(bidx); |
| 560 | AFFS_DATA_HEAD(bh)->size = cpu_to_be32(tmp); |
| 561 | affs_fix_checksum(sb, bh); |
| 562 | bh->b_state &= ~(1UL << BH_New); |
| 563 | mark_buffer_dirty_inode(bh, inode); |
| 564 | if (prev_bh) { |
| 565 | u32 tmp = be32_to_cpu(AFFS_DATA_HEAD(prev_bh)->next); |
| 566 | if (tmp) |
| 567 | affs_warning(sb, "extent_file_ofs", "next block already set for %d (%d)", bidx, tmp); |
| 568 | AFFS_DATA_HEAD(prev_bh)->next = cpu_to_be32(bh->b_blocknr); |
| 569 | affs_adjust_checksum(prev_bh, bh->b_blocknr - tmp); |
| 570 | mark_buffer_dirty_inode(prev_bh, inode); |
| 571 | affs_brelse(prev_bh); |
| 572 | } |
| 573 | size += bsize; |
| 574 | bidx++; |
| 575 | } |
| 576 | affs_brelse(bh); |
| 577 | inode->i_size = AFFS_I(inode)->mmu_private = newsize; |
| 578 | return 0; |
| 579 | |
| 580 | out: |
| 581 | inode->i_size = AFFS_I(inode)->mmu_private = newsize; |
| 582 | return PTR_ERR(bh); |
| 583 | } |
| 584 | |
| 585 | static int |
| 586 | affs_readpage_ofs(struct file *file, struct page *page) |
| 587 | { |
| 588 | struct inode *inode = page->mapping->host; |
| 589 | u32 to; |
| 590 | int err; |
| 591 | |
| 592 | pr_debug("AFFS: read_page(%u, %ld)\n", (u32)inode->i_ino, page->index); |
| 593 | to = PAGE_CACHE_SIZE; |
| 594 | if (((page->index + 1) << PAGE_CACHE_SHIFT) > inode->i_size) { |
| 595 | to = inode->i_size & ~PAGE_CACHE_MASK; |
| 596 | memset(page_address(page) + to, 0, PAGE_CACHE_SIZE - to); |
| 597 | } |
| 598 | |
| 599 | err = affs_do_readpage_ofs(file, page, 0, to); |
| 600 | if (!err) |
| 601 | SetPageUptodate(page); |
| 602 | unlock_page(page); |
| 603 | return err; |
| 604 | } |
| 605 | |
| 606 | static int affs_prepare_write_ofs(struct file *file, struct page *page, unsigned from, unsigned to) |
| 607 | { |
| 608 | struct inode *inode = page->mapping->host; |
| 609 | u32 size, offset; |
| 610 | u32 tmp; |
| 611 | int err = 0; |
| 612 | |
| 613 | pr_debug("AFFS: prepare_write(%u, %ld, %d, %d)\n", (u32)inode->i_ino, page->index, from, to); |
| 614 | offset = page->index << PAGE_CACHE_SHIFT; |
| 615 | if (offset + from > AFFS_I(inode)->mmu_private) { |
| 616 | err = affs_extent_file_ofs(inode, offset + from); |
| 617 | if (err) |
| 618 | return err; |
| 619 | } |
| 620 | size = inode->i_size; |
| 621 | |
| 622 | if (PageUptodate(page)) |
| 623 | return 0; |
| 624 | |
| 625 | if (from) { |
| 626 | err = affs_do_readpage_ofs(file, page, 0, from); |
| 627 | if (err) |
| 628 | return err; |
| 629 | } |
| 630 | if (to < PAGE_CACHE_SIZE) { |
| 631 | char *kaddr = kmap_atomic(page, KM_USER0); |
| 632 | |
| 633 | memset(kaddr + to, 0, PAGE_CACHE_SIZE - to); |
| 634 | flush_dcache_page(page); |
| 635 | kunmap_atomic(kaddr, KM_USER0); |
| 636 | if (size > offset + to) { |
| 637 | if (size < offset + PAGE_CACHE_SIZE) |
| 638 | tmp = size & ~PAGE_CACHE_MASK; |
| 639 | else |
| 640 | tmp = PAGE_CACHE_SIZE; |
| 641 | err = affs_do_readpage_ofs(file, page, to, tmp); |
| 642 | } |
| 643 | } |
| 644 | return err; |
| 645 | } |
| 646 | |
| 647 | static int affs_commit_write_ofs(struct file *file, struct page *page, unsigned from, unsigned to) |
| 648 | { |
| 649 | struct inode *inode = page->mapping->host; |
| 650 | struct super_block *sb = inode->i_sb; |
| 651 | struct buffer_head *bh, *prev_bh; |
| 652 | char *data; |
| 653 | u32 bidx, boff, bsize; |
| 654 | u32 tmp; |
| 655 | int written; |
| 656 | |
| 657 | pr_debug("AFFS: commit_write(%u, %ld, %d, %d)\n", (u32)inode->i_ino, page->index, from, to); |
| 658 | bsize = AFFS_SB(sb)->s_data_blksize; |
| 659 | data = page_address(page); |
| 660 | |
| 661 | bh = NULL; |
| 662 | written = 0; |
| 663 | tmp = (page->index << PAGE_CACHE_SHIFT) + from; |
| 664 | bidx = tmp / bsize; |
| 665 | boff = tmp % bsize; |
| 666 | if (boff) { |
| 667 | bh = affs_bread_ino(inode, bidx, 0); |
| 668 | if (IS_ERR(bh)) |
| 669 | return PTR_ERR(bh); |
| 670 | tmp = min(bsize - boff, to - from); |
| 671 | if (boff + tmp > bsize || tmp > bsize) |
| 672 | BUG(); |
| 673 | memcpy(AFFS_DATA(bh) + boff, data + from, tmp); |
| 674 | AFFS_DATA_HEAD(bh)->size = cpu_to_be32(be32_to_cpu(AFFS_DATA_HEAD(bh)->size) + tmp); |
| 675 | affs_fix_checksum(sb, bh); |
| 676 | mark_buffer_dirty_inode(bh, inode); |
| 677 | written += tmp; |
| 678 | from += tmp; |
| 679 | bidx++; |
| 680 | } else if (bidx) { |
| 681 | bh = affs_bread_ino(inode, bidx - 1, 0); |
| 682 | if (IS_ERR(bh)) |
| 683 | return PTR_ERR(bh); |
| 684 | } |
| 685 | while (from + bsize <= to) { |
| 686 | prev_bh = bh; |
| 687 | bh = affs_getemptyblk_ino(inode, bidx); |
| 688 | if (IS_ERR(bh)) |
| 689 | goto out; |
| 690 | memcpy(AFFS_DATA(bh), data + from, bsize); |
| 691 | if (buffer_new(bh)) { |
| 692 | AFFS_DATA_HEAD(bh)->ptype = cpu_to_be32(T_DATA); |
| 693 | AFFS_DATA_HEAD(bh)->key = cpu_to_be32(inode->i_ino); |
| 694 | AFFS_DATA_HEAD(bh)->sequence = cpu_to_be32(bidx); |
| 695 | AFFS_DATA_HEAD(bh)->size = cpu_to_be32(bsize); |
| 696 | AFFS_DATA_HEAD(bh)->next = 0; |
| 697 | bh->b_state &= ~(1UL << BH_New); |
| 698 | if (prev_bh) { |
| 699 | u32 tmp = be32_to_cpu(AFFS_DATA_HEAD(prev_bh)->next); |
| 700 | if (tmp) |
| 701 | affs_warning(sb, "commit_write_ofs", "next block already set for %d (%d)", bidx, tmp); |
| 702 | AFFS_DATA_HEAD(prev_bh)->next = cpu_to_be32(bh->b_blocknr); |
| 703 | affs_adjust_checksum(prev_bh, bh->b_blocknr - tmp); |
| 704 | mark_buffer_dirty_inode(prev_bh, inode); |
| 705 | } |
| 706 | } |
| 707 | affs_brelse(prev_bh); |
| 708 | affs_fix_checksum(sb, bh); |
| 709 | mark_buffer_dirty_inode(bh, inode); |
| 710 | written += bsize; |
| 711 | from += bsize; |
| 712 | bidx++; |
| 713 | } |
| 714 | if (from < to) { |
| 715 | prev_bh = bh; |
| 716 | bh = affs_bread_ino(inode, bidx, 1); |
| 717 | if (IS_ERR(bh)) |
| 718 | goto out; |
| 719 | tmp = min(bsize, to - from); |
| 720 | if (tmp > bsize) |
| 721 | BUG(); |
| 722 | memcpy(AFFS_DATA(bh), data + from, tmp); |
| 723 | if (buffer_new(bh)) { |
| 724 | AFFS_DATA_HEAD(bh)->ptype = cpu_to_be32(T_DATA); |
| 725 | AFFS_DATA_HEAD(bh)->key = cpu_to_be32(inode->i_ino); |
| 726 | AFFS_DATA_HEAD(bh)->sequence = cpu_to_be32(bidx); |
| 727 | AFFS_DATA_HEAD(bh)->size = cpu_to_be32(tmp); |
| 728 | AFFS_DATA_HEAD(bh)->next = 0; |
| 729 | bh->b_state &= ~(1UL << BH_New); |
| 730 | if (prev_bh) { |
| 731 | u32 tmp = be32_to_cpu(AFFS_DATA_HEAD(prev_bh)->next); |
| 732 | if (tmp) |
| 733 | affs_warning(sb, "commit_write_ofs", "next block already set for %d (%d)", bidx, tmp); |
| 734 | AFFS_DATA_HEAD(prev_bh)->next = cpu_to_be32(bh->b_blocknr); |
| 735 | affs_adjust_checksum(prev_bh, bh->b_blocknr - tmp); |
| 736 | mark_buffer_dirty_inode(prev_bh, inode); |
| 737 | } |
| 738 | } else if (be32_to_cpu(AFFS_DATA_HEAD(bh)->size) < tmp) |
| 739 | AFFS_DATA_HEAD(bh)->size = cpu_to_be32(tmp); |
| 740 | affs_brelse(prev_bh); |
| 741 | affs_fix_checksum(sb, bh); |
| 742 | mark_buffer_dirty_inode(bh, inode); |
| 743 | written += tmp; |
| 744 | from += tmp; |
| 745 | bidx++; |
| 746 | } |
| 747 | SetPageUptodate(page); |
| 748 | |
| 749 | done: |
| 750 | affs_brelse(bh); |
| 751 | tmp = (page->index << PAGE_CACHE_SHIFT) + from; |
| 752 | if (tmp > inode->i_size) |
| 753 | inode->i_size = AFFS_I(inode)->mmu_private = tmp; |
| 754 | |
| 755 | return written; |
| 756 | |
| 757 | out: |
| 758 | bh = prev_bh; |
| 759 | if (!written) |
| 760 | written = PTR_ERR(bh); |
| 761 | goto done; |
| 762 | } |
| 763 | |
Christoph Hellwig | f5e54d6 | 2006-06-28 04:26:44 -0700 | [diff] [blame] | 764 | const struct address_space_operations affs_aops_ofs = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 765 | .readpage = affs_readpage_ofs, |
| 766 | //.writepage = affs_writepage_ofs, |
| 767 | //.sync_page = affs_sync_page_ofs, |
| 768 | .prepare_write = affs_prepare_write_ofs, |
| 769 | .commit_write = affs_commit_write_ofs |
| 770 | }; |
| 771 | |
| 772 | /* Free any preallocated blocks. */ |
| 773 | |
| 774 | void |
| 775 | affs_free_prealloc(struct inode *inode) |
| 776 | { |
| 777 | struct super_block *sb = inode->i_sb; |
| 778 | |
| 779 | pr_debug("AFFS: free_prealloc(ino=%lu)\n", inode->i_ino); |
| 780 | |
| 781 | while (AFFS_I(inode)->i_pa_cnt) { |
| 782 | AFFS_I(inode)->i_pa_cnt--; |
| 783 | affs_free_block(sb, ++AFFS_I(inode)->i_lastalloc); |
| 784 | } |
| 785 | } |
| 786 | |
| 787 | /* Truncate (or enlarge) a file to the requested size. */ |
| 788 | |
| 789 | void |
| 790 | affs_truncate(struct inode *inode) |
| 791 | { |
| 792 | struct super_block *sb = inode->i_sb; |
| 793 | u32 ext, ext_key; |
| 794 | u32 last_blk, blkcnt, blk; |
| 795 | u32 size; |
| 796 | struct buffer_head *ext_bh; |
| 797 | int i; |
| 798 | |
| 799 | pr_debug("AFFS: truncate(inode=%d, oldsize=%u, newsize=%u)\n", |
| 800 | (u32)inode->i_ino, (u32)AFFS_I(inode)->mmu_private, (u32)inode->i_size); |
| 801 | |
| 802 | last_blk = 0; |
| 803 | ext = 0; |
| 804 | if (inode->i_size) { |
| 805 | last_blk = ((u32)inode->i_size - 1) / AFFS_SB(sb)->s_data_blksize; |
| 806 | ext = last_blk / AFFS_SB(sb)->s_hashsize; |
| 807 | } |
| 808 | |
| 809 | if (inode->i_size > AFFS_I(inode)->mmu_private) { |
| 810 | struct address_space *mapping = inode->i_mapping; |
| 811 | struct page *page; |
| 812 | u32 size = inode->i_size - 1; |
| 813 | int res; |
| 814 | |
| 815 | page = grab_cache_page(mapping, size >> PAGE_CACHE_SHIFT); |
| 816 | if (!page) |
| 817 | return; |
| 818 | size = (size & (PAGE_CACHE_SIZE - 1)) + 1; |
| 819 | res = mapping->a_ops->prepare_write(NULL, page, size, size); |
| 820 | if (!res) |
| 821 | res = mapping->a_ops->commit_write(NULL, page, size, size); |
| 822 | unlock_page(page); |
| 823 | page_cache_release(page); |
| 824 | mark_inode_dirty(inode); |
| 825 | return; |
| 826 | } else if (inode->i_size == AFFS_I(inode)->mmu_private) |
| 827 | return; |
| 828 | |
| 829 | // lock cache |
| 830 | ext_bh = affs_get_extblock(inode, ext); |
| 831 | if (IS_ERR(ext_bh)) { |
| 832 | affs_warning(sb, "truncate", "unexpected read error for ext block %u (%d)", |
| 833 | ext, PTR_ERR(ext_bh)); |
| 834 | return; |
| 835 | } |
| 836 | if (AFFS_I(inode)->i_lc) { |
| 837 | /* clear linear cache */ |
| 838 | i = (ext + 1) >> AFFS_I(inode)->i_lc_shift; |
| 839 | if (AFFS_I(inode)->i_lc_size > i) { |
| 840 | AFFS_I(inode)->i_lc_size = i; |
| 841 | for (; i < AFFS_LC_SIZE; i++) |
| 842 | AFFS_I(inode)->i_lc[i] = 0; |
| 843 | } |
| 844 | /* clear associative cache */ |
| 845 | for (i = 0; i < AFFS_AC_SIZE; i++) |
| 846 | if (AFFS_I(inode)->i_ac[i].ext >= ext) |
| 847 | AFFS_I(inode)->i_ac[i].ext = 0; |
| 848 | } |
| 849 | ext_key = be32_to_cpu(AFFS_TAIL(sb, ext_bh)->extension); |
| 850 | |
| 851 | blkcnt = AFFS_I(inode)->i_blkcnt; |
| 852 | i = 0; |
| 853 | blk = last_blk; |
| 854 | if (inode->i_size) { |
| 855 | i = last_blk % AFFS_SB(sb)->s_hashsize + 1; |
| 856 | blk++; |
| 857 | } else |
| 858 | AFFS_HEAD(ext_bh)->first_data = 0; |
| 859 | size = AFFS_SB(sb)->s_hashsize; |
| 860 | if (size > blkcnt - blk + i) |
| 861 | size = blkcnt - blk + i; |
| 862 | for (; i < size; i++, blk++) { |
| 863 | affs_free_block(sb, be32_to_cpu(AFFS_BLOCK(sb, ext_bh, i))); |
| 864 | AFFS_BLOCK(sb, ext_bh, i) = 0; |
| 865 | } |
| 866 | AFFS_TAIL(sb, ext_bh)->extension = 0; |
| 867 | affs_fix_checksum(sb, ext_bh); |
| 868 | mark_buffer_dirty_inode(ext_bh, inode); |
| 869 | affs_brelse(ext_bh); |
| 870 | |
| 871 | if (inode->i_size) { |
| 872 | AFFS_I(inode)->i_blkcnt = last_blk + 1; |
| 873 | AFFS_I(inode)->i_extcnt = ext + 1; |
| 874 | if (AFFS_SB(sb)->s_flags & SF_OFS) { |
| 875 | struct buffer_head *bh = affs_bread_ino(inode, last_blk, 0); |
| 876 | u32 tmp; |
| 877 | if (IS_ERR(ext_bh)) { |
| 878 | affs_warning(sb, "truncate", "unexpected read error for last block %u (%d)", |
| 879 | ext, PTR_ERR(ext_bh)); |
| 880 | return; |
| 881 | } |
| 882 | tmp = be32_to_cpu(AFFS_DATA_HEAD(bh)->next); |
| 883 | AFFS_DATA_HEAD(bh)->next = 0; |
| 884 | affs_adjust_checksum(bh, -tmp); |
| 885 | affs_brelse(bh); |
| 886 | } |
| 887 | } else { |
| 888 | AFFS_I(inode)->i_blkcnt = 0; |
| 889 | AFFS_I(inode)->i_extcnt = 1; |
| 890 | } |
| 891 | AFFS_I(inode)->mmu_private = inode->i_size; |
| 892 | // unlock cache |
| 893 | |
| 894 | while (ext_key) { |
| 895 | ext_bh = affs_bread(sb, ext_key); |
| 896 | size = AFFS_SB(sb)->s_hashsize; |
| 897 | if (size > blkcnt - blk) |
| 898 | size = blkcnt - blk; |
| 899 | for (i = 0; i < size; i++, blk++) |
| 900 | affs_free_block(sb, be32_to_cpu(AFFS_BLOCK(sb, ext_bh, i))); |
| 901 | affs_free_block(sb, ext_key); |
| 902 | ext_key = be32_to_cpu(AFFS_TAIL(sb, ext_bh)->extension); |
| 903 | affs_brelse(ext_bh); |
| 904 | } |
| 905 | affs_free_prealloc(inode); |
| 906 | } |