1 /* 2 * linux/fs/ext2/inode.c 3 * 4 * Copyright (C) 1992, 1993, 1994, 1995 5 * Remy Card (card@masi.ibp.fr) 6 * Laboratoire MASI - Institut Blaise Pascal 7 * Universite Pierre et Marie Curie (Paris VI) 8 * 9 * from 10 * 11 * linux/fs/minix/inode.c 12 * 13 * Copyright (C) 1991, 1992 Linus Torvalds 14 * 15 * Goal-directed block allocation by Stephen Tweedie 16 * (sct@dcs.ed.ac.uk), 1993, 1998 17 * Big-endian to little-endian byte-swapping/bitmaps by 18 * David S. Miller (davem@caip.rutgers.edu), 1995 19 * 64-bit file support on 64-bit platforms by Jakub Jelinek 20 * (jj@sunsite.ms.mff.cuni.cz) 21 * 22 * Assorted race fixes, rewrite of ext2_get_block() by Al Viro, 2000 23 */ 24 25 #include <linux/smp_lock.h> 26 #include <linux/time.h> 27 #include <linux/highuid.h> 28 #include <linux/pagemap.h> 29 #include <linux/quotaops.h> 30 #include <linux/module.h> 31 #include <linux/writeback.h> 32 #include <linux/buffer_head.h> 33 #include <linux/mpage.h> 34 #include "ext2.h" 35 #include "acl.h" 36 37 MODULE_AUTHOR("Remy Card and others"); 38 MODULE_DESCRIPTION("Second Extended Filesystem"); 39 MODULE_LICENSE("GPL"); 40 41 static int ext2_update_inode(struct inode * inode, int do_sync); 42 43 /* 44 * Test whether an inode is a fast symlink. 45 */ 46 static inline int ext2_inode_is_fast_symlink(struct inode *inode) 47 { 48 int ea_blocks = EXT2_I(inode)->i_file_acl ? 49 (inode->i_sb->s_blocksize >> 9) : 0; 50 51 return (S_ISLNK(inode->i_mode) && 52 inode->i_blocks - ea_blocks == 0); 53 } 54 55 /* 56 * Called at each iput(). 57 * 58 * The inode may be "bad" if ext2_read_inode() saw an error from 59 * ext2_get_inode(), so we need to check that to avoid freeing random disk 60 * blocks. 61 */ 62 void ext2_put_inode(struct inode *inode) 63 { 64 if (!is_bad_inode(inode)) 65 ext2_discard_prealloc(inode); 66 } 67 68 /* 69 * Called at the last iput() if i_nlink is zero. 70 */ 71 void ext2_delete_inode (struct inode * inode) 72 { 73 if (is_bad_inode(inode)) 74 goto no_delete; 75 EXT2_I(inode)->i_dtime = get_seconds(); 76 mark_inode_dirty(inode); 77 ext2_update_inode(inode, inode_needs_sync(inode)); 78 79 inode->i_size = 0; 80 if (inode->i_blocks) 81 ext2_truncate (inode); 82 ext2_free_inode (inode); 83 84 return; 85 no_delete: 86 clear_inode(inode); /* We must guarantee clearing of inode... */ 87 } 88 89 void ext2_discard_prealloc (struct inode * inode) 90 { 91 #ifdef EXT2_PREALLOCATE 92 struct ext2_inode_info *ei = EXT2_I(inode); 93 write_lock(&ei->i_meta_lock); 94 if (ei->i_prealloc_count) { 95 unsigned short total = ei->i_prealloc_count; 96 unsigned long block = ei->i_prealloc_block; 97 ei->i_prealloc_count = 0; 98 ei->i_prealloc_block = 0; 99 write_unlock(&ei->i_meta_lock); 100 ext2_free_blocks (inode, block, total); 101 return; 102 } else 103 write_unlock(&ei->i_meta_lock); 104 #endif 105 } 106 107 static int ext2_alloc_block (struct inode * inode, unsigned long goal, int *err) 108 { 109 #ifdef EXT2FS_DEBUG 110 static unsigned long alloc_hits, alloc_attempts; 111 #endif 112 unsigned long result; 113 114 115 #ifdef EXT2_PREALLOCATE 116 struct ext2_inode_info *ei = EXT2_I(inode); 117 write_lock(&ei->i_meta_lock); 118 if (ei->i_prealloc_count && 119 (goal == ei->i_prealloc_block || goal + 1 == ei->i_prealloc_block)) 120 { 121 result = ei->i_prealloc_block++; 122 ei->i_prealloc_count--; 123 write_unlock(&ei->i_meta_lock); 124 ext2_debug ("preallocation hit (%lu/%lu).\n", 125 ++alloc_hits, ++alloc_attempts); 126 } else { 127 write_unlock(&ei->i_meta_lock); 128 ext2_discard_prealloc (inode); 129 ext2_debug ("preallocation miss (%lu/%lu).\n", 130 alloc_hits, ++alloc_attempts); 131 if (S_ISREG(inode->i_mode)) 132 result = ext2_new_block (inode, goal, 133 &ei->i_prealloc_count, 134 &ei->i_prealloc_block, err); 135 else 136 result = ext2_new_block(inode, goal, NULL, NULL, err); 137 } 138 #else 139 result = ext2_new_block (inode, goal, 0, 0, err); 140 #endif 141 return result; 142 } 143 144 typedef struct { 145 __le32 *p; 146 __le32 key; 147 struct buffer_head *bh; 148 } Indirect; 149 150 static inline void add_chain(Indirect *p, struct buffer_head *bh, __le32 *v) 151 { 152 p->key = *(p->p = v); 153 p->bh = bh; 154 } 155 156 static inline int verify_chain(Indirect *from, Indirect *to) 157 { 158 while (from <= to && from->key == *from->p) 159 from++; 160 return (from > to); 161 } 162 163 /** 164 * ext2_block_to_path - parse the block number into array of offsets 165 * @inode: inode in question (we are only interested in its superblock) 166 * @i_block: block number to be parsed 167 * @offsets: array to store the offsets in 168 * @boundary: set this non-zero if the referred-to block is likely to be 169 * followed (on disk) by an indirect block. 170 * To store the locations of file's data ext2 uses a data structure common 171 * for UNIX filesystems - tree of pointers anchored in the inode, with 172 * data blocks at leaves and indirect blocks in intermediate nodes. 173 * This function translates the block number into path in that tree - 174 * return value is the path length and @offsets[n] is the offset of 175 * pointer to (n+1)th node in the nth one. If @block is out of range 176 * (negative or too large) warning is printed and zero returned. 177 * 178 * Note: function doesn't find node addresses, so no IO is needed. All 179 * we need to know is the capacity of indirect blocks (taken from the 180 * inode->i_sb). 181 */ 182 183 /* 184 * Portability note: the last comparison (check that we fit into triple 185 * indirect block) is spelled differently, because otherwise on an 186 * architecture with 32-bit longs and 8Kb pages we might get into trouble 187 * if our filesystem had 8Kb blocks. We might use long long, but that would 188 * kill us on x86. Oh, well, at least the sign propagation does not matter - 189 * i_block would have to be negative in the very beginning, so we would not 190 * get there at all. 191 */ 192 193 static int ext2_block_to_path(struct inode *inode, 194 long i_block, int offsets[4], int *boundary) 195 { 196 int ptrs = EXT2_ADDR_PER_BLOCK(inode->i_sb); 197 int ptrs_bits = EXT2_ADDR_PER_BLOCK_BITS(inode->i_sb); 198 const long direct_blocks = EXT2_NDIR_BLOCKS, 199 indirect_blocks = ptrs, 200 double_blocks = (1 << (ptrs_bits * 2)); 201 int n = 0; 202 int final = 0; 203 204 if (i_block < 0) { 205 ext2_warning (inode->i_sb, "ext2_block_to_path", "block < 0"); 206 } else if (i_block < direct_blocks) { 207 offsets[n++] = i_block; 208 final = direct_blocks; 209 } else if ( (i_block -= direct_blocks) < indirect_blocks) { 210 offsets[n++] = EXT2_IND_BLOCK; 211 offsets[n++] = i_block; 212 final = ptrs; 213 } else if ((i_block -= indirect_blocks) < double_blocks) { 214 offsets[n++] = EXT2_DIND_BLOCK; 215 offsets[n++] = i_block >> ptrs_bits; 216 offsets[n++] = i_block & (ptrs - 1); 217 final = ptrs; 218 } else if (((i_block -= double_blocks) >> (ptrs_bits * 2)) < ptrs) { 219 offsets[n++] = EXT2_TIND_BLOCK; 220 offsets[n++] = i_block >> (ptrs_bits * 2); 221 offsets[n++] = (i_block >> ptrs_bits) & (ptrs - 1); 222 offsets[n++] = i_block & (ptrs - 1); 223 final = ptrs; 224 } else { 225 ext2_warning (inode->i_sb, "ext2_block_to_path", "block > big"); 226 } 227 if (boundary) 228 *boundary = (i_block & (ptrs - 1)) == (final - 1); 229 return n; 230 } 231 232 /** 233 * ext2_get_branch - read the chain of indirect blocks leading to data 234 * @inode: inode in question 235 * @depth: depth of the chain (1 - direct pointer, etc.) 236 * @offsets: offsets of pointers in inode/indirect blocks 237 * @chain: place to store the result 238 * @err: here we store the error value 239 * 240 * Function fills the array of triples <key, p, bh> and returns %NULL 241 * if everything went OK or the pointer to the last filled triple 242 * (incomplete one) otherwise. Upon the return chain[i].key contains 243 * the number of (i+1)-th block in the chain (as it is stored in memory, 244 * i.e. little-endian 32-bit), chain[i].p contains the address of that 245 * number (it points into struct inode for i==0 and into the bh->b_data 246 * for i>0) and chain[i].bh points to the buffer_head of i-th indirect 247 * block for i>0 and NULL for i==0. In other words, it holds the block 248 * numbers of the chain, addresses they were taken from (and where we can 249 * verify that chain did not change) and buffer_heads hosting these 250 * numbers. 251 * 252 * Function stops when it stumbles upon zero pointer (absent block) 253 * (pointer to last triple returned, *@err == 0) 254 * or when it gets an IO error reading an indirect block 255 * (ditto, *@err == -EIO) 256 * or when it notices that chain had been changed while it was reading 257 * (ditto, *@err == -EAGAIN) 258 * or when it reads all @depth-1 indirect blocks successfully and finds 259 * the whole chain, all way to the data (returns %NULL, *err == 0). 260 */ 261 static Indirect *ext2_get_branch(struct inode *inode, 262 int depth, 263 int *offsets, 264 Indirect chain[4], 265 int *err) 266 { 267 struct super_block *sb = inode->i_sb; 268 Indirect *p = chain; 269 struct buffer_head *bh; 270 271 *err = 0; 272 /* i_data is not going away, no lock needed */ 273 add_chain (chain, NULL, EXT2_I(inode)->i_data + *offsets); 274 if (!p->key) 275 goto no_block; 276 while (--depth) { 277 bh = sb_bread(sb, le32_to_cpu(p->key)); 278 if (!bh) 279 goto failure; 280 read_lock(&EXT2_I(inode)->i_meta_lock); 281 if (!verify_chain(chain, p)) 282 goto changed; 283 add_chain(++p, bh, (__le32*)bh->b_data + *++offsets); 284 read_unlock(&EXT2_I(inode)->i_meta_lock); 285 if (!p->key) 286 goto no_block; 287 } 288 return NULL; 289 290 changed: 291 read_unlock(&EXT2_I(inode)->i_meta_lock); 292 brelse(bh); 293 *err = -EAGAIN; 294 goto no_block; 295 failure: 296 *err = -EIO; 297 no_block: 298 return p; 299 } 300 301 /** 302 * ext2_find_near - find a place for allocation with sufficient locality 303 * @inode: owner 304 * @ind: descriptor of indirect block. 305 * 306 * This function returns the prefered place for block allocation. 307 * It is used when heuristic for sequential allocation fails. 308 * Rules are: 309 * + if there is a block to the left of our position - allocate near it. 310 * + if pointer will live in indirect block - allocate near that block. 311 * + if pointer will live in inode - allocate in the same cylinder group. 312 * 313 * In the latter case we colour the starting block by the callers PID to 314 * prevent it from clashing with concurrent allocations for a different inode 315 * in the same block group. The PID is used here so that functionally related 316 * files will be close-by on-disk. 317 * 318 * Caller must make sure that @ind is valid and will stay that way. 319 */ 320 321 static unsigned long ext2_find_near(struct inode *inode, Indirect *ind) 322 { 323 struct ext2_inode_info *ei = EXT2_I(inode); 324 __le32 *start = ind->bh ? (__le32 *) ind->bh->b_data : ei->i_data; 325 __le32 *p; 326 unsigned long bg_start; 327 unsigned long colour; 328 329 /* Try to find previous block */ 330 for (p = ind->p - 1; p >= start; p--) 331 if (*p) 332 return le32_to_cpu(*p); 333 334 /* No such thing, so let's try location of indirect block */ 335 if (ind->bh) 336 return ind->bh->b_blocknr; 337 338 /* 339 * It is going to be refered from inode itself? OK, just put it into 340 * the same cylinder group then. 341 */ 342 bg_start = (ei->i_block_group * EXT2_BLOCKS_PER_GROUP(inode->i_sb)) + 343 le32_to_cpu(EXT2_SB(inode->i_sb)->s_es->s_first_data_block); 344 colour = (current->pid % 16) * 345 (EXT2_BLOCKS_PER_GROUP(inode->i_sb) / 16); 346 return bg_start + colour; 347 } 348 349 /** 350 * ext2_find_goal - find a prefered place for allocation. 351 * @inode: owner 352 * @block: block we want 353 * @chain: chain of indirect blocks 354 * @partial: pointer to the last triple within a chain 355 * @goal: place to store the result. 356 * 357 * Normally this function find the prefered place for block allocation, 358 * stores it in *@goal and returns zero. If the branch had been changed 359 * under us we return -EAGAIN. 360 */ 361 362 static inline int ext2_find_goal(struct inode *inode, 363 long block, 364 Indirect chain[4], 365 Indirect *partial, 366 unsigned long *goal) 367 { 368 struct ext2_inode_info *ei = EXT2_I(inode); 369 write_lock(&ei->i_meta_lock); 370 if ((block == ei->i_next_alloc_block + 1) && ei->i_next_alloc_goal) { 371 ei->i_next_alloc_block++; 372 ei->i_next_alloc_goal++; 373 } 374 if (verify_chain(chain, partial)) { 375 /* 376 * try the heuristic for sequential allocation, 377 * failing that at least try to get decent locality. 378 */ 379 if (block == ei->i_next_alloc_block) 380 *goal = ei->i_next_alloc_goal; 381 if (!*goal) 382 *goal = ext2_find_near(inode, partial); 383 write_unlock(&ei->i_meta_lock); 384 return 0; 385 } 386 write_unlock(&ei->i_meta_lock); 387 return -EAGAIN; 388 } 389 390 /** 391 * ext2_alloc_branch - allocate and set up a chain of blocks. 392 * @inode: owner 393 * @num: depth of the chain (number of blocks to allocate) 394 * @offsets: offsets (in the blocks) to store the pointers to next. 395 * @branch: place to store the chain in. 396 * 397 * This function allocates @num blocks, zeroes out all but the last one, 398 * links them into chain and (if we are synchronous) writes them to disk. 399 * In other words, it prepares a branch that can be spliced onto the 400 * inode. It stores the information about that chain in the branch[], in 401 * the same format as ext2_get_branch() would do. We are calling it after 402 * we had read the existing part of chain and partial points to the last 403 * triple of that (one with zero ->key). Upon the exit we have the same 404 * picture as after the successful ext2_get_block(), excpet that in one 405 * place chain is disconnected - *branch->p is still zero (we did not 406 * set the last link), but branch->key contains the number that should 407 * be placed into *branch->p to fill that gap. 408 * 409 * If allocation fails we free all blocks we've allocated (and forget 410 * their buffer_heads) and return the error value the from failed 411 * ext2_alloc_block() (normally -ENOSPC). Otherwise we set the chain 412 * as described above and return 0. 413 */ 414 415 static int ext2_alloc_branch(struct inode *inode, 416 int num, 417 unsigned long goal, 418 int *offsets, 419 Indirect *branch) 420 { 421 int blocksize = inode->i_sb->s_blocksize; 422 int n = 0; 423 int err; 424 int i; 425 int parent = ext2_alloc_block(inode, goal, &err); 426 427 branch[0].key = cpu_to_le32(parent); 428 if (parent) for (n = 1; n < num; n++) { 429 struct buffer_head *bh; 430 /* Allocate the next block */ 431 int nr = ext2_alloc_block(inode, parent, &err); 432 if (!nr) 433 break; 434 branch[n].key = cpu_to_le32(nr); 435 /* 436 * Get buffer_head for parent block, zero it out and set 437 * the pointer to new one, then send parent to disk. 438 */ 439 bh = sb_getblk(inode->i_sb, parent); 440 lock_buffer(bh); 441 memset(bh->b_data, 0, blocksize); 442 branch[n].bh = bh; 443 branch[n].p = (__le32 *) bh->b_data + offsets[n]; 444 *branch[n].p = branch[n].key; 445 set_buffer_uptodate(bh); 446 unlock_buffer(bh); 447 mark_buffer_dirty_inode(bh, inode); 448 /* We used to sync bh here if IS_SYNC(inode). 449 * But we now rely upon generic_osync_inode() 450 * and b_inode_buffers. But not for directories. 451 */ 452 if (S_ISDIR(inode->i_mode) && IS_DIRSYNC(inode)) 453 sync_dirty_buffer(bh); 454 parent = nr; 455 } 456 if (n == num) 457 return 0; 458 459 /* Allocation failed, free what we already allocated */ 460 for (i = 1; i < n; i++) 461 bforget(branch[i].bh); 462 for (i = 0; i < n; i++) 463 ext2_free_blocks(inode, le32_to_cpu(branch[i].key), 1); 464 return err; 465 } 466 467 /** 468 * ext2_splice_branch - splice the allocated branch onto inode. 469 * @inode: owner 470 * @block: (logical) number of block we are adding 471 * @chain: chain of indirect blocks (with a missing link - see 472 * ext2_alloc_branch) 473 * @where: location of missing link 474 * @num: number of blocks we are adding 475 * 476 * This function verifies that chain (up to the missing link) had not 477 * changed, fills the missing link and does all housekeeping needed in 478 * inode (->i_blocks, etc.). In case of success we end up with the full 479 * chain to new block and return 0. Otherwise (== chain had been changed) 480 * we free the new blocks (forgetting their buffer_heads, indeed) and 481 * return -EAGAIN. 482 */ 483 484 static inline int ext2_splice_branch(struct inode *inode, 485 long block, 486 Indirect chain[4], 487 Indirect *where, 488 int num) 489 { 490 struct ext2_inode_info *ei = EXT2_I(inode); 491 int i; 492 493 /* Verify that place we are splicing to is still there and vacant */ 494 495 write_lock(&ei->i_meta_lock); 496 if (!verify_chain(chain, where-1) || *where->p) 497 goto changed; 498 499 /* That's it */ 500 501 *where->p = where->key; 502 ei->i_next_alloc_block = block; 503 ei->i_next_alloc_goal = le32_to_cpu(where[num-1].key); 504 505 write_unlock(&ei->i_meta_lock); 506 507 /* We are done with atomic stuff, now do the rest of housekeeping */ 508 509 inode->i_ctime = CURRENT_TIME_SEC; 510 511 /* had we spliced it onto indirect block? */ 512 if (where->bh) 513 mark_buffer_dirty_inode(where->bh, inode); 514 515 mark_inode_dirty(inode); 516 return 0; 517 518 changed: 519 write_unlock(&ei->i_meta_lock); 520 for (i = 1; i < num; i++) 521 bforget(where[i].bh); 522 for (i = 0; i < num; i++) 523 ext2_free_blocks(inode, le32_to_cpu(where[i].key), 1); 524 return -EAGAIN; 525 } 526 527 /* 528 * Allocation strategy is simple: if we have to allocate something, we will 529 * have to go the whole way to leaf. So let's do it before attaching anything 530 * to tree, set linkage between the newborn blocks, write them if sync is 531 * required, recheck the path, free and repeat if check fails, otherwise 532 * set the last missing link (that will protect us from any truncate-generated 533 * removals - all blocks on the path are immune now) and possibly force the 534 * write on the parent block. 535 * That has a nice additional property: no special recovery from the failed 536 * allocations is needed - we simply release blocks and do not touch anything 537 * reachable from inode. 538 */ 539 540 int ext2_get_block(struct inode *inode, sector_t iblock, struct buffer_head *bh_result, int create) 541 { 542 int err = -EIO; 543 int offsets[4]; 544 Indirect chain[4]; 545 Indirect *partial; 546 unsigned long goal; 547 int left; 548 int boundary = 0; 549 int depth = ext2_block_to_path(inode, iblock, offsets, &boundary); 550 551 if (depth == 0) 552 goto out; 553 554 reread: 555 partial = ext2_get_branch(inode, depth, offsets, chain, &err); 556 557 /* Simplest case - block found, no allocation needed */ 558 if (!partial) { 559 got_it: 560 map_bh(bh_result, inode->i_sb, le32_to_cpu(chain[depth-1].key)); 561 if (boundary) 562 set_buffer_boundary(bh_result); 563 /* Clean up and exit */ 564 partial = chain+depth-1; /* the whole chain */ 565 goto cleanup; 566 } 567 568 /* Next simple case - plain lookup or failed read of indirect block */ 569 if (!create || err == -EIO) { 570 cleanup: 571 while (partial > chain) { 572 brelse(partial->bh); 573 partial--; 574 } 575 out: 576 return err; 577 } 578 579 /* 580 * Indirect block might be removed by truncate while we were 581 * reading it. Handling of that case (forget what we've got and 582 * reread) is taken out of the main path. 583 */ 584 if (err == -EAGAIN) 585 goto changed; 586 587 goal = 0; 588 if (ext2_find_goal(inode, iblock, chain, partial, &goal) < 0) 589 goto changed; 590 591 left = (chain + depth) - partial; 592 err = ext2_alloc_branch(inode, left, goal, 593 offsets+(partial-chain), partial); 594 if (err) 595 goto cleanup; 596 597 if (ext2_splice_branch(inode, iblock, chain, partial, left) < 0) 598 goto changed; 599 600 set_buffer_new(bh_result); 601 goto got_it; 602 603 changed: 604 while (partial > chain) { 605 brelse(partial->bh); 606 partial--; 607 } 608 goto reread; 609 } 610 611 static int ext2_writepage(struct page *page, struct writeback_control *wbc) 612 { 613 return block_write_full_page(page, ext2_get_block, wbc); 614 } 615 616 static int ext2_readpage(struct file *file, struct page *page) 617 { 618 return mpage_readpage(page, ext2_get_block); 619 } 620 621 static int 622 ext2_readpages(struct file *file, struct address_space *mapping, 623 struct list_head *pages, unsigned nr_pages) 624 { 625 return mpage_readpages(mapping, pages, nr_pages, ext2_get_block); 626 } 627 628 static int 629 ext2_prepare_write(struct file *file, struct page *page, 630 unsigned from, unsigned to) 631 { 632 return block_prepare_write(page,from,to,ext2_get_block); 633 } 634 635 static int 636 ext2_nobh_prepare_write(struct file *file, struct page *page, 637 unsigned from, unsigned to) 638 { 639 return nobh_prepare_write(page,from,to,ext2_get_block); 640 } 641 642 static int ext2_nobh_writepage(struct page *page, 643 struct writeback_control *wbc) 644 { 645 return nobh_writepage(page, ext2_get_block, wbc); 646 } 647 648 static sector_t ext2_bmap(struct address_space *mapping, sector_t block) 649 { 650 return generic_block_bmap(mapping,block,ext2_get_block); 651 } 652 653 static int 654 ext2_get_blocks(struct inode *inode, sector_t iblock, unsigned long max_blocks, 655 struct buffer_head *bh_result, int create) 656 { 657 int ret; 658 659 ret = ext2_get_block(inode, iblock, bh_result, create); 660 if (ret == 0) 661 bh_result->b_size = (1 << inode->i_blkbits); 662 return ret; 663 } 664 665 static ssize_t 666 ext2_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov, 667 loff_t offset, unsigned long nr_segs) 668 { 669 struct file *file = iocb->ki_filp; 670 struct inode *inode = file->f_mapping->host; 671 672 return blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev, iov, 673 offset, nr_segs, ext2_get_blocks, NULL); 674 } 675 676 static int 677 ext2_writepages(struct address_space *mapping, struct writeback_control *wbc) 678 { 679 return mpage_writepages(mapping, wbc, ext2_get_block); 680 } 681 682 struct address_space_operations ext2_aops = { 683 .readpage = ext2_readpage, 684 .readpages = ext2_readpages, 685 .writepage = ext2_writepage, 686 .sync_page = block_sync_page, 687 .prepare_write = ext2_prepare_write, 688 .commit_write = generic_commit_write, 689 .bmap = ext2_bmap, 690 .direct_IO = ext2_direct_IO, 691 .writepages = ext2_writepages, 692 }; 693 694 struct address_space_operations ext2_nobh_aops = { 695 .readpage = ext2_readpage, 696 .readpages = ext2_readpages, 697 .writepage = ext2_nobh_writepage, 698 .sync_page = block_sync_page, 699 .prepare_write = ext2_nobh_prepare_write, 700 .commit_write = nobh_commit_write, 701 .bmap = ext2_bmap, 702 .direct_IO = ext2_direct_IO, 703 .writepages = ext2_writepages, 704 }; 705 706 /* 707 * Probably it should be a library function... search for first non-zero word 708 * or memcmp with zero_page, whatever is better for particular architecture. 709 * Linus? 710 */ 711 static inline int all_zeroes(__le32 *p, __le32 *q) 712 { 713 while (p < q) 714 if (*p++) 715 return 0; 716 return 1; 717 } 718 719 /** 720 * ext2_find_shared - find the indirect blocks for partial truncation. 721 * @inode: inode in question 722 * @depth: depth of the affected branch 723 * @offsets: offsets of pointers in that branch (see ext2_block_to_path) 724 * @chain: place to store the pointers to partial indirect blocks 725 * @top: place to the (detached) top of branch 726 * 727 * This is a helper function used by ext2_truncate(). 728 * 729 * When we do truncate() we may have to clean the ends of several indirect 730 * blocks but leave the blocks themselves alive. Block is partially 731 * truncated if some data below the new i_size is refered from it (and 732 * it is on the path to the first completely truncated data block, indeed). 733 * We have to free the top of that path along with everything to the right 734 * of the path. Since no allocation past the truncation point is possible 735 * until ext2_truncate() finishes, we may safely do the latter, but top 736 * of branch may require special attention - pageout below the truncation 737 * point might try to populate it. 738 * 739 * We atomically detach the top of branch from the tree, store the block 740 * number of its root in *@top, pointers to buffer_heads of partially 741 * truncated blocks - in @chain[].bh and pointers to their last elements 742 * that should not be removed - in @chain[].p. Return value is the pointer 743 * to last filled element of @chain. 744 * 745 * The work left to caller to do the actual freeing of subtrees: 746 * a) free the subtree starting from *@top 747 * b) free the subtrees whose roots are stored in 748 * (@chain[i].p+1 .. end of @chain[i].bh->b_data) 749 * c) free the subtrees growing from the inode past the @chain[0].p 750 * (no partially truncated stuff there). 751 */ 752 753 static Indirect *ext2_find_shared(struct inode *inode, 754 int depth, 755 int offsets[4], 756 Indirect chain[4], 757 __le32 *top) 758 { 759 Indirect *partial, *p; 760 int k, err; 761 762 *top = 0; 763 for (k = depth; k > 1 && !offsets[k-1]; k--) 764 ; 765 partial = ext2_get_branch(inode, k, offsets, chain, &err); 766 if (!partial) 767 partial = chain + k-1; 768 /* 769 * If the branch acquired continuation since we've looked at it - 770 * fine, it should all survive and (new) top doesn't belong to us. 771 */ 772 write_lock(&EXT2_I(inode)->i_meta_lock); 773 if (!partial->key && *partial->p) { 774 write_unlock(&EXT2_I(inode)->i_meta_lock); 775 goto no_top; 776 } 777 for (p=partial; p>chain && all_zeroes((__le32*)p->bh->b_data,p->p); p--) 778 ; 779 /* 780 * OK, we've found the last block that must survive. The rest of our 781 * branch should be detached before unlocking. However, if that rest 782 * of branch is all ours and does not grow immediately from the inode 783 * it's easier to cheat and just decrement partial->p. 784 */ 785 if (p == chain + k - 1 && p > chain) { 786 p->p--; 787 } else { 788 *top = *p->p; 789 *p->p = 0; 790 } 791 write_unlock(&EXT2_I(inode)->i_meta_lock); 792 793 while(partial > p) 794 { 795 brelse(partial->bh); 796 partial--; 797 } 798 no_top: 799 return partial; 800 } 801 802 /** 803 * ext2_free_data - free a list of data blocks 804 * @inode: inode we are dealing with 805 * @p: array of block numbers 806 * @q: points immediately past the end of array 807 * 808 * We are freeing all blocks refered from that array (numbers are 809 * stored as little-endian 32-bit) and updating @inode->i_blocks 810 * appropriately. 811 */ 812 static inline void ext2_free_data(struct inode *inode, __le32 *p, __le32 *q) 813 { 814 unsigned long block_to_free = 0, count = 0; 815 unsigned long nr; 816 817 for ( ; p < q ; p++) { 818 nr = le32_to_cpu(*p); 819 if (nr) { 820 *p = 0; 821 /* accumulate blocks to free if they're contiguous */ 822 if (count == 0) 823 goto free_this; 824 else if (block_to_free == nr - count) 825 count++; 826 else { 827 mark_inode_dirty(inode); 828 ext2_free_blocks (inode, block_to_free, count); 829 free_this: 830 block_to_free = nr; 831 count = 1; 832 } 833 } 834 } 835 if (count > 0) { 836 mark_inode_dirty(inode); 837 ext2_free_blocks (inode, block_to_free, count); 838 } 839 } 840 841 /** 842 * ext2_free_branches - free an array of branches 843 * @inode: inode we are dealing with 844 * @p: array of block numbers 845 * @q: pointer immediately past the end of array 846 * @depth: depth of the branches to free 847 * 848 * We are freeing all blocks refered from these branches (numbers are 849 * stored as little-endian 32-bit) and updating @inode->i_blocks 850 * appropriately. 851 */ 852 static void ext2_free_branches(struct inode *inode, __le32 *p, __le32 *q, int depth) 853 { 854 struct buffer_head * bh; 855 unsigned long nr; 856 857 if (depth--) { 858 int addr_per_block = EXT2_ADDR_PER_BLOCK(inode->i_sb); 859 for ( ; p < q ; p++) { 860 nr = le32_to_cpu(*p); 861 if (!nr) 862 continue; 863 *p = 0; 864 bh = sb_bread(inode->i_sb, nr); 865 /* 866 * A read failure? Report error and clear slot 867 * (should be rare). 868 */ 869 if (!bh) { 870 ext2_error(inode->i_sb, "ext2_free_branches", 871 "Read failure, inode=%ld, block=%ld", 872 inode->i_ino, nr); 873 continue; 874 } 875 ext2_free_branches(inode, 876 (__le32*)bh->b_data, 877 (__le32*)bh->b_data + addr_per_block, 878 depth); 879 bforget(bh); 880 ext2_free_blocks(inode, nr, 1); 881 mark_inode_dirty(inode); 882 } 883 } else 884 ext2_free_data(inode, p, q); 885 } 886 887 void ext2_truncate (struct inode * inode) 888 { 889 __le32 *i_data = EXT2_I(inode)->i_data; 890 int addr_per_block = EXT2_ADDR_PER_BLOCK(inode->i_sb); 891 int offsets[4]; 892 Indirect chain[4]; 893 Indirect *partial; 894 __le32 nr = 0; 895 int n; 896 long iblock; 897 unsigned blocksize; 898 899 if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || 900 S_ISLNK(inode->i_mode))) 901 return; 902 if (ext2_inode_is_fast_symlink(inode)) 903 return; 904 if (IS_APPEND(inode) || IS_IMMUTABLE(inode)) 905 return; 906 907 ext2_discard_prealloc(inode); 908 909 blocksize = inode->i_sb->s_blocksize; 910 iblock = (inode->i_size + blocksize-1) 911 >> EXT2_BLOCK_SIZE_BITS(inode->i_sb); 912 913 if (test_opt(inode->i_sb, NOBH)) 914 nobh_truncate_page(inode->i_mapping, inode->i_size); 915 else 916 block_truncate_page(inode->i_mapping, 917 inode->i_size, ext2_get_block); 918 919 n = ext2_block_to_path(inode, iblock, offsets, NULL); 920 if (n == 0) 921 return; 922 923 if (n == 1) { 924 ext2_free_data(inode, i_data+offsets[0], 925 i_data + EXT2_NDIR_BLOCKS); 926 goto do_indirects; 927 } 928 929 partial = ext2_find_shared(inode, n, offsets, chain, &nr); 930 /* Kill the top of shared branch (already detached) */ 931 if (nr) { 932 if (partial == chain) 933 mark_inode_dirty(inode); 934 else 935 mark_buffer_dirty_inode(partial->bh, inode); 936 ext2_free_branches(inode, &nr, &nr+1, (chain+n-1) - partial); 937 } 938 /* Clear the ends of indirect blocks on the shared branch */ 939 while (partial > chain) { 940 ext2_free_branches(inode, 941 partial->p + 1, 942 (__le32*)partial->bh->b_data+addr_per_block, 943 (chain+n-1) - partial); 944 mark_buffer_dirty_inode(partial->bh, inode); 945 brelse (partial->bh); 946 partial--; 947 } 948 do_indirects: 949 /* Kill the remaining (whole) subtrees */ 950 switch (offsets[0]) { 951 default: 952 nr = i_data[EXT2_IND_BLOCK]; 953 if (nr) { 954 i_data[EXT2_IND_BLOCK] = 0; 955 mark_inode_dirty(inode); 956 ext2_free_branches(inode, &nr, &nr+1, 1); 957 } 958 case EXT2_IND_BLOCK: 959 nr = i_data[EXT2_DIND_BLOCK]; 960 if (nr) { 961 i_data[EXT2_DIND_BLOCK] = 0; 962 mark_inode_dirty(inode); 963 ext2_free_branches(inode, &nr, &nr+1, 2); 964 } 965 case EXT2_DIND_BLOCK: 966 nr = i_data[EXT2_TIND_BLOCK]; 967 if (nr) { 968 i_data[EXT2_TIND_BLOCK] = 0; 969 mark_inode_dirty(inode); 970 ext2_free_branches(inode, &nr, &nr+1, 3); 971 } 972 case EXT2_TIND_BLOCK: 973 ; 974 } 975 inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC; 976 if (inode_needs_sync(inode)) { 977 sync_mapping_buffers(inode->i_mapping); 978 ext2_sync_inode (inode); 979 } else { 980 mark_inode_dirty(inode); 981 } 982 } 983 984 static struct ext2_inode *ext2_get_inode(struct super_block *sb, ino_t ino, 985 struct buffer_head **p) 986 { 987 struct buffer_head * bh; 988 unsigned long block_group; 989 unsigned long block; 990 unsigned long offset; 991 struct ext2_group_desc * gdp; 992 993 *p = NULL; 994 if ((ino != EXT2_ROOT_INO && ino < EXT2_FIRST_INO(sb)) || 995 ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count)) 996 goto Einval; 997 998 block_group = (ino - 1) / EXT2_INODES_PER_GROUP(sb); 999 gdp = ext2_get_group_desc(sb, block_group, &bh); 1000 if (!gdp) 1001 goto Egdp; 1002 /* 1003 * Figure out the offset within the block group inode table 1004 */ 1005 offset = ((ino - 1) % EXT2_INODES_PER_GROUP(sb)) * EXT2_INODE_SIZE(sb); 1006 block = le32_to_cpu(gdp->bg_inode_table) + 1007 (offset >> EXT2_BLOCK_SIZE_BITS(sb)); 1008 if (!(bh = sb_bread(sb, block))) 1009 goto Eio; 1010 1011 *p = bh; 1012 offset &= (EXT2_BLOCK_SIZE(sb) - 1); 1013 return (struct ext2_inode *) (bh->b_data + offset); 1014 1015 Einval: 1016 ext2_error(sb, "ext2_get_inode", "bad inode number: %lu", 1017 (unsigned long) ino); 1018 return ERR_PTR(-EINVAL); 1019 Eio: 1020 ext2_error(sb, "ext2_get_inode", 1021 "unable to read inode block - inode=%lu, block=%lu", 1022 (unsigned long) ino, block); 1023 Egdp: 1024 return ERR_PTR(-EIO); 1025 } 1026 1027 void ext2_set_inode_flags(struct inode *inode) 1028 { 1029 unsigned int flags = EXT2_I(inode)->i_flags; 1030 1031 inode->i_flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC); 1032 if (flags & EXT2_SYNC_FL) 1033 inode->i_flags |= S_SYNC; 1034 if (flags & EXT2_APPEND_FL) 1035 inode->i_flags |= S_APPEND; 1036 if (flags & EXT2_IMMUTABLE_FL) 1037 inode->i_flags |= S_IMMUTABLE; 1038 if (flags & EXT2_NOATIME_FL) 1039 inode->i_flags |= S_NOATIME; 1040 if (flags & EXT2_DIRSYNC_FL) 1041 inode->i_flags |= S_DIRSYNC; 1042 } 1043 1044 void ext2_read_inode (struct inode * inode) 1045 { 1046 struct ext2_inode_info *ei = EXT2_I(inode); 1047 ino_t ino = inode->i_ino; 1048 struct buffer_head * bh; 1049 struct ext2_inode * raw_inode = ext2_get_inode(inode->i_sb, ino, &bh); 1050 int n; 1051 1052 #ifdef CONFIG_EXT2_FS_POSIX_ACL 1053 ei->i_acl = EXT2_ACL_NOT_CACHED; 1054 ei->i_default_acl = EXT2_ACL_NOT_CACHED; 1055 #endif 1056 if (IS_ERR(raw_inode)) 1057 goto bad_inode; 1058 1059 inode->i_mode = le16_to_cpu(raw_inode->i_mode); 1060 inode->i_uid = (uid_t)le16_to_cpu(raw_inode->i_uid_low); 1061 inode->i_gid = (gid_t)le16_to_cpu(raw_inode->i_gid_low); 1062 if (!(test_opt (inode->i_sb, NO_UID32))) { 1063 inode->i_uid |= le16_to_cpu(raw_inode->i_uid_high) << 16; 1064 inode->i_gid |= le16_to_cpu(raw_inode->i_gid_high) << 16; 1065 } 1066 inode->i_nlink = le16_to_cpu(raw_inode->i_links_count); 1067 inode->i_size = le32_to_cpu(raw_inode->i_size); 1068 inode->i_atime.tv_sec = le32_to_cpu(raw_inode->i_atime); 1069 inode->i_ctime.tv_sec = le32_to_cpu(raw_inode->i_ctime); 1070 inode->i_mtime.tv_sec = le32_to_cpu(raw_inode->i_mtime); 1071 inode->i_atime.tv_nsec = inode->i_mtime.tv_nsec = inode->i_ctime.tv_nsec = 0; 1072 ei->i_dtime = le32_to_cpu(raw_inode->i_dtime); 1073 /* We now have enough fields to check if the inode was active or not. 1074 * This is needed because nfsd might try to access dead inodes 1075 * the test is that same one that e2fsck uses 1076 * NeilBrown 1999oct15 1077 */ 1078 if (inode->i_nlink == 0 && (inode->i_mode == 0 || ei->i_dtime)) { 1079 /* this inode is deleted */ 1080 brelse (bh); 1081 goto bad_inode; 1082 } 1083 inode->i_blksize = PAGE_SIZE; /* This is the optimal IO size (for stat), not the fs block size */ 1084 inode->i_blocks = le32_to_cpu(raw_inode->i_blocks); 1085 ei->i_flags = le32_to_cpu(raw_inode->i_flags); 1086 ei->i_faddr = le32_to_cpu(raw_inode->i_faddr); 1087 ei->i_frag_no = raw_inode->i_frag; 1088 ei->i_frag_size = raw_inode->i_fsize; 1089 ei->i_file_acl = le32_to_cpu(raw_inode->i_file_acl); 1090 ei->i_dir_acl = 0; 1091 if (S_ISREG(inode->i_mode)) 1092 inode->i_size |= ((__u64)le32_to_cpu(raw_inode->i_size_high)) << 32; 1093 else 1094 ei->i_dir_acl = le32_to_cpu(raw_inode->i_dir_acl); 1095 ei->i_dtime = 0; 1096 inode->i_generation = le32_to_cpu(raw_inode->i_generation); 1097 ei->i_state = 0; 1098 ei->i_next_alloc_block = 0; 1099 ei->i_next_alloc_goal = 0; 1100 ei->i_prealloc_count = 0; 1101 ei->i_block_group = (ino - 1) / EXT2_INODES_PER_GROUP(inode->i_sb); 1102 ei->i_dir_start_lookup = 0; 1103 1104 /* 1105 * NOTE! The in-memory inode i_data array is in little-endian order 1106 * even on big-endian machines: we do NOT byteswap the block numbers! 1107 */ 1108 for (n = 0; n < EXT2_N_BLOCKS; n++) 1109 ei->i_data[n] = raw_inode->i_block[n]; 1110 1111 if (S_ISREG(inode->i_mode)) { 1112 inode->i_op = &ext2_file_inode_operations; 1113 inode->i_fop = &ext2_file_operations; 1114 if (test_opt(inode->i_sb, NOBH)) 1115 inode->i_mapping->a_ops = &ext2_nobh_aops; 1116 else 1117 inode->i_mapping->a_ops = &ext2_aops; 1118 } else if (S_ISDIR(inode->i_mode)) { 1119 inode->i_op = &ext2_dir_inode_operations; 1120 inode->i_fop = &ext2_dir_operations; 1121 if (test_opt(inode->i_sb, NOBH)) 1122 inode->i_mapping->a_ops = &ext2_nobh_aops; 1123 else 1124 inode->i_mapping->a_ops = &ext2_aops; 1125 } else if (S_ISLNK(inode->i_mode)) { 1126 if (ext2_inode_is_fast_symlink(inode)) 1127 inode->i_op = &ext2_fast_symlink_inode_operations; 1128 else { 1129 inode->i_op = &ext2_symlink_inode_operations; 1130 if (test_opt(inode->i_sb, NOBH)) 1131 inode->i_mapping->a_ops = &ext2_nobh_aops; 1132 else 1133 inode->i_mapping->a_ops = &ext2_aops; 1134 } 1135 } else { 1136 inode->i_op = &ext2_special_inode_operations; 1137 if (raw_inode->i_block[0]) 1138 init_special_inode(inode, inode->i_mode, 1139 old_decode_dev(le32_to_cpu(raw_inode->i_block[0]))); 1140 else 1141 init_special_inode(inode, inode->i_mode, 1142 new_decode_dev(le32_to_cpu(raw_inode->i_block[1]))); 1143 } 1144 brelse (bh); 1145 ext2_set_inode_flags(inode); 1146 return; 1147 1148 bad_inode: 1149 make_bad_inode(inode); 1150 return; 1151 } 1152 1153 static int ext2_update_inode(struct inode * inode, int do_sync) 1154 { 1155 struct ext2_inode_info *ei = EXT2_I(inode); 1156 struct super_block *sb = inode->i_sb; 1157 ino_t ino = inode->i_ino; 1158 uid_t uid = inode->i_uid; 1159 gid_t gid = inode->i_gid; 1160 struct buffer_head * bh; 1161 struct ext2_inode * raw_inode = ext2_get_inode(sb, ino, &bh); 1162 int n; 1163 int err = 0; 1164 1165 if (IS_ERR(raw_inode)) 1166 return -EIO; 1167 1168 /* For fields not not tracking in the in-memory inode, 1169 * initialise them to zero for new inodes. */ 1170 if (ei->i_state & EXT2_STATE_NEW) 1171 memset(raw_inode, 0, EXT2_SB(sb)->s_inode_size); 1172 1173 raw_inode->i_mode = cpu_to_le16(inode->i_mode); 1174 if (!(test_opt(sb, NO_UID32))) { 1175 raw_inode->i_uid_low = cpu_to_le16(low_16_bits(uid)); 1176 raw_inode->i_gid_low = cpu_to_le16(low_16_bits(gid)); 1177 /* 1178 * Fix up interoperability with old kernels. Otherwise, old inodes get 1179 * re-used with the upper 16 bits of the uid/gid intact 1180 */ 1181 if (!ei->i_dtime) { 1182 raw_inode->i_uid_high = cpu_to_le16(high_16_bits(uid)); 1183 raw_inode->i_gid_high = cpu_to_le16(high_16_bits(gid)); 1184 } else { 1185 raw_inode->i_uid_high = 0; 1186 raw_inode->i_gid_high = 0; 1187 } 1188 } else { 1189 raw_inode->i_uid_low = cpu_to_le16(fs_high2lowuid(uid)); 1190 raw_inode->i_gid_low = cpu_to_le16(fs_high2lowgid(gid)); 1191 raw_inode->i_uid_high = 0; 1192 raw_inode->i_gid_high = 0; 1193 } 1194 raw_inode->i_links_count = cpu_to_le16(inode->i_nlink); 1195 raw_inode->i_size = cpu_to_le32(inode->i_size); 1196 raw_inode->i_atime = cpu_to_le32(inode->i_atime.tv_sec); 1197 raw_inode->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec); 1198 raw_inode->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec); 1199 1200 raw_inode->i_blocks = cpu_to_le32(inode->i_blocks); 1201 raw_inode->i_dtime = cpu_to_le32(ei->i_dtime); 1202 raw_inode->i_flags = cpu_to_le32(ei->i_flags); 1203 raw_inode->i_faddr = cpu_to_le32(ei->i_faddr); 1204 raw_inode->i_frag = ei->i_frag_no; 1205 raw_inode->i_fsize = ei->i_frag_size; 1206 raw_inode->i_file_acl = cpu_to_le32(ei->i_file_acl); 1207 if (!S_ISREG(inode->i_mode)) 1208 raw_inode->i_dir_acl = cpu_to_le32(ei->i_dir_acl); 1209 else { 1210 raw_inode->i_size_high = cpu_to_le32(inode->i_size >> 32); 1211 if (inode->i_size > 0x7fffffffULL) { 1212 if (!EXT2_HAS_RO_COMPAT_FEATURE(sb, 1213 EXT2_FEATURE_RO_COMPAT_LARGE_FILE) || 1214 EXT2_SB(sb)->s_es->s_rev_level == 1215 cpu_to_le32(EXT2_GOOD_OLD_REV)) { 1216 /* If this is the first large file 1217 * created, add a flag to the superblock. 1218 */ 1219 lock_kernel(); 1220 ext2_update_dynamic_rev(sb); 1221 EXT2_SET_RO_COMPAT_FEATURE(sb, 1222 EXT2_FEATURE_RO_COMPAT_LARGE_FILE); 1223 unlock_kernel(); 1224 ext2_write_super(sb); 1225 } 1226 } 1227 } 1228 1229 raw_inode->i_generation = cpu_to_le32(inode->i_generation); 1230 if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) { 1231 if (old_valid_dev(inode->i_rdev)) { 1232 raw_inode->i_block[0] = 1233 cpu_to_le32(old_encode_dev(inode->i_rdev)); 1234 raw_inode->i_block[1] = 0; 1235 } else { 1236 raw_inode->i_block[0] = 0; 1237 raw_inode->i_block[1] = 1238 cpu_to_le32(new_encode_dev(inode->i_rdev)); 1239 raw_inode->i_block[2] = 0; 1240 } 1241 } else for (n = 0; n < EXT2_N_BLOCKS; n++) 1242 raw_inode->i_block[n] = ei->i_data[n]; 1243 mark_buffer_dirty(bh); 1244 if (do_sync) { 1245 sync_dirty_buffer(bh); 1246 if (buffer_req(bh) && !buffer_uptodate(bh)) { 1247 printk ("IO error syncing ext2 inode [%s:%08lx]\n", 1248 sb->s_id, (unsigned long) ino); 1249 err = -EIO; 1250 } 1251 } 1252 ei->i_state &= ~EXT2_STATE_NEW; 1253 brelse (bh); 1254 return err; 1255 } 1256 1257 int ext2_write_inode(struct inode *inode, int wait) 1258 { 1259 return ext2_update_inode(inode, wait); 1260 } 1261 1262 int ext2_sync_inode(struct inode *inode) 1263 { 1264 struct writeback_control wbc = { 1265 .sync_mode = WB_SYNC_ALL, 1266 .nr_to_write = 0, /* sys_fsync did this */ 1267 }; 1268 return sync_inode(inode, &wbc); 1269 } 1270 1271 int ext2_setattr(struct dentry *dentry, struct iattr *iattr) 1272 { 1273 struct inode *inode = dentry->d_inode; 1274 int error; 1275 1276 error = inode_change_ok(inode, iattr); 1277 if (error) 1278 return error; 1279 if ((iattr->ia_valid & ATTR_UID && iattr->ia_uid != inode->i_uid) || 1280 (iattr->ia_valid & ATTR_GID && iattr->ia_gid != inode->i_gid)) { 1281 error = DQUOT_TRANSFER(inode, iattr) ? -EDQUOT : 0; 1282 if (error) 1283 return error; 1284 } 1285 error = inode_setattr(inode, iattr); 1286 if (!error && (iattr->ia_valid & ATTR_MODE)) 1287 error = ext2_acl_chmod(inode); 1288 return error; 1289 } 1290