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 <linux/fiemap.h> 35 #include <linux/namei.h> 36 #include "ext2.h" 37 #include "acl.h" 38 #include "xip.h" 39 40 MODULE_AUTHOR("Remy Card and others"); 41 MODULE_DESCRIPTION("Second Extended Filesystem"); 42 MODULE_LICENSE("GPL"); 43 44 static int ext2_update_inode(struct inode * inode, int do_sync); 45 46 /* 47 * Test whether an inode is a fast symlink. 48 */ 49 static inline int ext2_inode_is_fast_symlink(struct inode *inode) 50 { 51 int ea_blocks = EXT2_I(inode)->i_file_acl ? 52 (inode->i_sb->s_blocksize >> 9) : 0; 53 54 return (S_ISLNK(inode->i_mode) && 55 inode->i_blocks - ea_blocks == 0); 56 } 57 58 /* 59 * Called at the last iput() if i_nlink is zero. 60 */ 61 void ext2_delete_inode (struct inode * inode) 62 { 63 truncate_inode_pages(&inode->i_data, 0); 64 65 if (is_bad_inode(inode)) 66 goto no_delete; 67 EXT2_I(inode)->i_dtime = get_seconds(); 68 mark_inode_dirty(inode); 69 ext2_update_inode(inode, inode_needs_sync(inode)); 70 71 inode->i_size = 0; 72 if (inode->i_blocks) 73 ext2_truncate (inode); 74 ext2_free_inode (inode); 75 76 return; 77 no_delete: 78 clear_inode(inode); /* We must guarantee clearing of inode... */ 79 } 80 81 typedef struct { 82 __le32 *p; 83 __le32 key; 84 struct buffer_head *bh; 85 } Indirect; 86 87 static inline void add_chain(Indirect *p, struct buffer_head *bh, __le32 *v) 88 { 89 p->key = *(p->p = v); 90 p->bh = bh; 91 } 92 93 static inline int verify_chain(Indirect *from, Indirect *to) 94 { 95 while (from <= to && from->key == *from->p) 96 from++; 97 return (from > to); 98 } 99 100 /** 101 * ext2_block_to_path - parse the block number into array of offsets 102 * @inode: inode in question (we are only interested in its superblock) 103 * @i_block: block number to be parsed 104 * @offsets: array to store the offsets in 105 * @boundary: set this non-zero if the referred-to block is likely to be 106 * followed (on disk) by an indirect block. 107 * To store the locations of file's data ext2 uses a data structure common 108 * for UNIX filesystems - tree of pointers anchored in the inode, with 109 * data blocks at leaves and indirect blocks in intermediate nodes. 110 * This function translates the block number into path in that tree - 111 * return value is the path length and @offsets[n] is the offset of 112 * pointer to (n+1)th node in the nth one. If @block is out of range 113 * (negative or too large) warning is printed and zero returned. 114 * 115 * Note: function doesn't find node addresses, so no IO is needed. All 116 * we need to know is the capacity of indirect blocks (taken from the 117 * inode->i_sb). 118 */ 119 120 /* 121 * Portability note: the last comparison (check that we fit into triple 122 * indirect block) is spelled differently, because otherwise on an 123 * architecture with 32-bit longs and 8Kb pages we might get into trouble 124 * if our filesystem had 8Kb blocks. We might use long long, but that would 125 * kill us on x86. Oh, well, at least the sign propagation does not matter - 126 * i_block would have to be negative in the very beginning, so we would not 127 * get there at all. 128 */ 129 130 static int ext2_block_to_path(struct inode *inode, 131 long i_block, int offsets[4], int *boundary) 132 { 133 int ptrs = EXT2_ADDR_PER_BLOCK(inode->i_sb); 134 int ptrs_bits = EXT2_ADDR_PER_BLOCK_BITS(inode->i_sb); 135 const long direct_blocks = EXT2_NDIR_BLOCKS, 136 indirect_blocks = ptrs, 137 double_blocks = (1 << (ptrs_bits * 2)); 138 int n = 0; 139 int final = 0; 140 141 if (i_block < 0) { 142 ext2_warning (inode->i_sb, "ext2_block_to_path", "block < 0"); 143 } else if (i_block < direct_blocks) { 144 offsets[n++] = i_block; 145 final = direct_blocks; 146 } else if ( (i_block -= direct_blocks) < indirect_blocks) { 147 offsets[n++] = EXT2_IND_BLOCK; 148 offsets[n++] = i_block; 149 final = ptrs; 150 } else if ((i_block -= indirect_blocks) < double_blocks) { 151 offsets[n++] = EXT2_DIND_BLOCK; 152 offsets[n++] = i_block >> ptrs_bits; 153 offsets[n++] = i_block & (ptrs - 1); 154 final = ptrs; 155 } else if (((i_block -= double_blocks) >> (ptrs_bits * 2)) < ptrs) { 156 offsets[n++] = EXT2_TIND_BLOCK; 157 offsets[n++] = i_block >> (ptrs_bits * 2); 158 offsets[n++] = (i_block >> ptrs_bits) & (ptrs - 1); 159 offsets[n++] = i_block & (ptrs - 1); 160 final = ptrs; 161 } else { 162 ext2_warning (inode->i_sb, "ext2_block_to_path", "block > big"); 163 } 164 if (boundary) 165 *boundary = final - 1 - (i_block & (ptrs - 1)); 166 167 return n; 168 } 169 170 /** 171 * ext2_get_branch - read the chain of indirect blocks leading to data 172 * @inode: inode in question 173 * @depth: depth of the chain (1 - direct pointer, etc.) 174 * @offsets: offsets of pointers in inode/indirect blocks 175 * @chain: place to store the result 176 * @err: here we store the error value 177 * 178 * Function fills the array of triples <key, p, bh> and returns %NULL 179 * if everything went OK or the pointer to the last filled triple 180 * (incomplete one) otherwise. Upon the return chain[i].key contains 181 * the number of (i+1)-th block in the chain (as it is stored in memory, 182 * i.e. little-endian 32-bit), chain[i].p contains the address of that 183 * number (it points into struct inode for i==0 and into the bh->b_data 184 * for i>0) and chain[i].bh points to the buffer_head of i-th indirect 185 * block for i>0 and NULL for i==0. In other words, it holds the block 186 * numbers of the chain, addresses they were taken from (and where we can 187 * verify that chain did not change) and buffer_heads hosting these 188 * numbers. 189 * 190 * Function stops when it stumbles upon zero pointer (absent block) 191 * (pointer to last triple returned, *@err == 0) 192 * or when it gets an IO error reading an indirect block 193 * (ditto, *@err == -EIO) 194 * or when it notices that chain had been changed while it was reading 195 * (ditto, *@err == -EAGAIN) 196 * or when it reads all @depth-1 indirect blocks successfully and finds 197 * the whole chain, all way to the data (returns %NULL, *err == 0). 198 */ 199 static Indirect *ext2_get_branch(struct inode *inode, 200 int depth, 201 int *offsets, 202 Indirect chain[4], 203 int *err) 204 { 205 struct super_block *sb = inode->i_sb; 206 Indirect *p = chain; 207 struct buffer_head *bh; 208 209 *err = 0; 210 /* i_data is not going away, no lock needed */ 211 add_chain (chain, NULL, EXT2_I(inode)->i_data + *offsets); 212 if (!p->key) 213 goto no_block; 214 while (--depth) { 215 bh = sb_bread(sb, le32_to_cpu(p->key)); 216 if (!bh) 217 goto failure; 218 read_lock(&EXT2_I(inode)->i_meta_lock); 219 if (!verify_chain(chain, p)) 220 goto changed; 221 add_chain(++p, bh, (__le32*)bh->b_data + *++offsets); 222 read_unlock(&EXT2_I(inode)->i_meta_lock); 223 if (!p->key) 224 goto no_block; 225 } 226 return NULL; 227 228 changed: 229 read_unlock(&EXT2_I(inode)->i_meta_lock); 230 brelse(bh); 231 *err = -EAGAIN; 232 goto no_block; 233 failure: 234 *err = -EIO; 235 no_block: 236 return p; 237 } 238 239 /** 240 * ext2_find_near - find a place for allocation with sufficient locality 241 * @inode: owner 242 * @ind: descriptor of indirect block. 243 * 244 * This function returns the preferred place for block allocation. 245 * It is used when heuristic for sequential allocation fails. 246 * Rules are: 247 * + if there is a block to the left of our position - allocate near it. 248 * + if pointer will live in indirect block - allocate near that block. 249 * + if pointer will live in inode - allocate in the same cylinder group. 250 * 251 * In the latter case we colour the starting block by the callers PID to 252 * prevent it from clashing with concurrent allocations for a different inode 253 * in the same block group. The PID is used here so that functionally related 254 * files will be close-by on-disk. 255 * 256 * Caller must make sure that @ind is valid and will stay that way. 257 */ 258 259 static ext2_fsblk_t ext2_find_near(struct inode *inode, Indirect *ind) 260 { 261 struct ext2_inode_info *ei = EXT2_I(inode); 262 __le32 *start = ind->bh ? (__le32 *) ind->bh->b_data : ei->i_data; 263 __le32 *p; 264 ext2_fsblk_t bg_start; 265 ext2_fsblk_t colour; 266 267 /* Try to find previous block */ 268 for (p = ind->p - 1; p >= start; p--) 269 if (*p) 270 return le32_to_cpu(*p); 271 272 /* No such thing, so let's try location of indirect block */ 273 if (ind->bh) 274 return ind->bh->b_blocknr; 275 276 /* 277 * It is going to be refered from inode itself? OK, just put it into 278 * the same cylinder group then. 279 */ 280 bg_start = ext2_group_first_block_no(inode->i_sb, ei->i_block_group); 281 colour = (current->pid % 16) * 282 (EXT2_BLOCKS_PER_GROUP(inode->i_sb) / 16); 283 return bg_start + colour; 284 } 285 286 /** 287 * ext2_find_goal - find a preferred place for allocation. 288 * @inode: owner 289 * @block: block we want 290 * @partial: pointer to the last triple within a chain 291 * 292 * Returns preferred place for a block (the goal). 293 */ 294 295 static inline ext2_fsblk_t ext2_find_goal(struct inode *inode, long block, 296 Indirect *partial) 297 { 298 struct ext2_block_alloc_info *block_i; 299 300 block_i = EXT2_I(inode)->i_block_alloc_info; 301 302 /* 303 * try the heuristic for sequential allocation, 304 * failing that at least try to get decent locality. 305 */ 306 if (block_i && (block == block_i->last_alloc_logical_block + 1) 307 && (block_i->last_alloc_physical_block != 0)) { 308 return block_i->last_alloc_physical_block + 1; 309 } 310 311 return ext2_find_near(inode, partial); 312 } 313 314 /** 315 * ext2_blks_to_allocate: Look up the block map and count the number 316 * of direct blocks need to be allocated for the given branch. 317 * 318 * @branch: chain of indirect blocks 319 * @k: number of blocks need for indirect blocks 320 * @blks: number of data blocks to be mapped. 321 * @blocks_to_boundary: the offset in the indirect block 322 * 323 * return the total number of blocks to be allocate, including the 324 * direct and indirect blocks. 325 */ 326 static int 327 ext2_blks_to_allocate(Indirect * branch, int k, unsigned long blks, 328 int blocks_to_boundary) 329 { 330 unsigned long count = 0; 331 332 /* 333 * Simple case, [t,d]Indirect block(s) has not allocated yet 334 * then it's clear blocks on that path have not allocated 335 */ 336 if (k > 0) { 337 /* right now don't hanel cross boundary allocation */ 338 if (blks < blocks_to_boundary + 1) 339 count += blks; 340 else 341 count += blocks_to_boundary + 1; 342 return count; 343 } 344 345 count++; 346 while (count < blks && count <= blocks_to_boundary 347 && le32_to_cpu(*(branch[0].p + count)) == 0) { 348 count++; 349 } 350 return count; 351 } 352 353 /** 354 * ext2_alloc_blocks: multiple allocate blocks needed for a branch 355 * @indirect_blks: the number of blocks need to allocate for indirect 356 * blocks 357 * 358 * @new_blocks: on return it will store the new block numbers for 359 * the indirect blocks(if needed) and the first direct block, 360 * @blks: on return it will store the total number of allocated 361 * direct blocks 362 */ 363 static int ext2_alloc_blocks(struct inode *inode, 364 ext2_fsblk_t goal, int indirect_blks, int blks, 365 ext2_fsblk_t new_blocks[4], int *err) 366 { 367 int target, i; 368 unsigned long count = 0; 369 int index = 0; 370 ext2_fsblk_t current_block = 0; 371 int ret = 0; 372 373 /* 374 * Here we try to allocate the requested multiple blocks at once, 375 * on a best-effort basis. 376 * To build a branch, we should allocate blocks for 377 * the indirect blocks(if not allocated yet), and at least 378 * the first direct block of this branch. That's the 379 * minimum number of blocks need to allocate(required) 380 */ 381 target = blks + indirect_blks; 382 383 while (1) { 384 count = target; 385 /* allocating blocks for indirect blocks and direct blocks */ 386 current_block = ext2_new_blocks(inode,goal,&count,err); 387 if (*err) 388 goto failed_out; 389 390 target -= count; 391 /* allocate blocks for indirect blocks */ 392 while (index < indirect_blks && count) { 393 new_blocks[index++] = current_block++; 394 count--; 395 } 396 397 if (count > 0) 398 break; 399 } 400 401 /* save the new block number for the first direct block */ 402 new_blocks[index] = current_block; 403 404 /* total number of blocks allocated for direct blocks */ 405 ret = count; 406 *err = 0; 407 return ret; 408 failed_out: 409 for (i = 0; i <index; i++) 410 ext2_free_blocks(inode, new_blocks[i], 1); 411 return ret; 412 } 413 414 /** 415 * ext2_alloc_branch - allocate and set up a chain of blocks. 416 * @inode: owner 417 * @num: depth of the chain (number of blocks to allocate) 418 * @offsets: offsets (in the blocks) to store the pointers to next. 419 * @branch: place to store the chain in. 420 * 421 * This function allocates @num blocks, zeroes out all but the last one, 422 * links them into chain and (if we are synchronous) writes them to disk. 423 * In other words, it prepares a branch that can be spliced onto the 424 * inode. It stores the information about that chain in the branch[], in 425 * the same format as ext2_get_branch() would do. We are calling it after 426 * we had read the existing part of chain and partial points to the last 427 * triple of that (one with zero ->key). Upon the exit we have the same 428 * picture as after the successful ext2_get_block(), excpet that in one 429 * place chain is disconnected - *branch->p is still zero (we did not 430 * set the last link), but branch->key contains the number that should 431 * be placed into *branch->p to fill that gap. 432 * 433 * If allocation fails we free all blocks we've allocated (and forget 434 * their buffer_heads) and return the error value the from failed 435 * ext2_alloc_block() (normally -ENOSPC). Otherwise we set the chain 436 * as described above and return 0. 437 */ 438 439 static int ext2_alloc_branch(struct inode *inode, 440 int indirect_blks, int *blks, ext2_fsblk_t goal, 441 int *offsets, Indirect *branch) 442 { 443 int blocksize = inode->i_sb->s_blocksize; 444 int i, n = 0; 445 int err = 0; 446 struct buffer_head *bh; 447 int num; 448 ext2_fsblk_t new_blocks[4]; 449 ext2_fsblk_t current_block; 450 451 num = ext2_alloc_blocks(inode, goal, indirect_blks, 452 *blks, new_blocks, &err); 453 if (err) 454 return err; 455 456 branch[0].key = cpu_to_le32(new_blocks[0]); 457 /* 458 * metadata blocks and data blocks are allocated. 459 */ 460 for (n = 1; n <= indirect_blks; n++) { 461 /* 462 * Get buffer_head for parent block, zero it out 463 * and set the pointer to new one, then send 464 * parent to disk. 465 */ 466 bh = sb_getblk(inode->i_sb, new_blocks[n-1]); 467 branch[n].bh = bh; 468 lock_buffer(bh); 469 memset(bh->b_data, 0, blocksize); 470 branch[n].p = (__le32 *) bh->b_data + offsets[n]; 471 branch[n].key = cpu_to_le32(new_blocks[n]); 472 *branch[n].p = branch[n].key; 473 if ( n == indirect_blks) { 474 current_block = new_blocks[n]; 475 /* 476 * End of chain, update the last new metablock of 477 * the chain to point to the new allocated 478 * data blocks numbers 479 */ 480 for (i=1; i < num; i++) 481 *(branch[n].p + i) = cpu_to_le32(++current_block); 482 } 483 set_buffer_uptodate(bh); 484 unlock_buffer(bh); 485 mark_buffer_dirty_inode(bh, inode); 486 /* We used to sync bh here if IS_SYNC(inode). 487 * But we now rely upon generic_osync_inode() 488 * and b_inode_buffers. But not for directories. 489 */ 490 if (S_ISDIR(inode->i_mode) && IS_DIRSYNC(inode)) 491 sync_dirty_buffer(bh); 492 } 493 *blks = num; 494 return err; 495 } 496 497 /** 498 * ext2_splice_branch - splice the allocated branch onto inode. 499 * @inode: owner 500 * @block: (logical) number of block we are adding 501 * @chain: chain of indirect blocks (with a missing link - see 502 * ext2_alloc_branch) 503 * @where: location of missing link 504 * @num: number of indirect blocks we are adding 505 * @blks: number of direct blocks we are adding 506 * 507 * This function fills the missing link and does all housekeeping needed in 508 * inode (->i_blocks, etc.). In case of success we end up with the full 509 * chain to new block and return 0. 510 */ 511 static void ext2_splice_branch(struct inode *inode, 512 long block, Indirect *where, int num, int blks) 513 { 514 int i; 515 struct ext2_block_alloc_info *block_i; 516 ext2_fsblk_t current_block; 517 518 block_i = EXT2_I(inode)->i_block_alloc_info; 519 520 /* XXX LOCKING probably should have i_meta_lock ?*/ 521 /* That's it */ 522 523 *where->p = where->key; 524 525 /* 526 * Update the host buffer_head or inode to point to more just allocated 527 * direct blocks blocks 528 */ 529 if (num == 0 && blks > 1) { 530 current_block = le32_to_cpu(where->key) + 1; 531 for (i = 1; i < blks; i++) 532 *(where->p + i ) = cpu_to_le32(current_block++); 533 } 534 535 /* 536 * update the most recently allocated logical & physical block 537 * in i_block_alloc_info, to assist find the proper goal block for next 538 * allocation 539 */ 540 if (block_i) { 541 block_i->last_alloc_logical_block = block + blks - 1; 542 block_i->last_alloc_physical_block = 543 le32_to_cpu(where[num].key) + blks - 1; 544 } 545 546 /* We are done with atomic stuff, now do the rest of housekeeping */ 547 548 /* had we spliced it onto indirect block? */ 549 if (where->bh) 550 mark_buffer_dirty_inode(where->bh, inode); 551 552 inode->i_ctime = CURRENT_TIME_SEC; 553 mark_inode_dirty(inode); 554 } 555 556 /* 557 * Allocation strategy is simple: if we have to allocate something, we will 558 * have to go the whole way to leaf. So let's do it before attaching anything 559 * to tree, set linkage between the newborn blocks, write them if sync is 560 * required, recheck the path, free and repeat if check fails, otherwise 561 * set the last missing link (that will protect us from any truncate-generated 562 * removals - all blocks on the path are immune now) and possibly force the 563 * write on the parent block. 564 * That has a nice additional property: no special recovery from the failed 565 * allocations is needed - we simply release blocks and do not touch anything 566 * reachable from inode. 567 * 568 * `handle' can be NULL if create == 0. 569 * 570 * return > 0, # of blocks mapped or allocated. 571 * return = 0, if plain lookup failed. 572 * return < 0, error case. 573 */ 574 static int ext2_get_blocks(struct inode *inode, 575 sector_t iblock, unsigned long maxblocks, 576 struct buffer_head *bh_result, 577 int create) 578 { 579 int err = -EIO; 580 int offsets[4]; 581 Indirect chain[4]; 582 Indirect *partial; 583 ext2_fsblk_t goal; 584 int indirect_blks; 585 int blocks_to_boundary = 0; 586 int depth; 587 struct ext2_inode_info *ei = EXT2_I(inode); 588 int count = 0; 589 ext2_fsblk_t first_block = 0; 590 591 depth = ext2_block_to_path(inode,iblock,offsets,&blocks_to_boundary); 592 593 if (depth == 0) 594 return (err); 595 reread: 596 partial = ext2_get_branch(inode, depth, offsets, chain, &err); 597 598 /* Simplest case - block found, no allocation needed */ 599 if (!partial) { 600 first_block = le32_to_cpu(chain[depth - 1].key); 601 clear_buffer_new(bh_result); /* What's this do? */ 602 count++; 603 /*map more blocks*/ 604 while (count < maxblocks && count <= blocks_to_boundary) { 605 ext2_fsblk_t blk; 606 607 if (!verify_chain(chain, partial)) { 608 /* 609 * Indirect block might be removed by 610 * truncate while we were reading it. 611 * Handling of that case: forget what we've 612 * got now, go to reread. 613 */ 614 count = 0; 615 goto changed; 616 } 617 blk = le32_to_cpu(*(chain[depth-1].p + count)); 618 if (blk == first_block + count) 619 count++; 620 else 621 break; 622 } 623 goto got_it; 624 } 625 626 /* Next simple case - plain lookup or failed read of indirect block */ 627 if (!create || err == -EIO) 628 goto cleanup; 629 630 mutex_lock(&ei->truncate_mutex); 631 632 /* 633 * Okay, we need to do block allocation. Lazily initialize the block 634 * allocation info here if necessary 635 */ 636 if (S_ISREG(inode->i_mode) && (!ei->i_block_alloc_info)) 637 ext2_init_block_alloc_info(inode); 638 639 goal = ext2_find_goal(inode, iblock, partial); 640 641 /* the number of blocks need to allocate for [d,t]indirect blocks */ 642 indirect_blks = (chain + depth) - partial - 1; 643 /* 644 * Next look up the indirect map to count the totoal number of 645 * direct blocks to allocate for this branch. 646 */ 647 count = ext2_blks_to_allocate(partial, indirect_blks, 648 maxblocks, blocks_to_boundary); 649 /* 650 * XXX ???? Block out ext2_truncate while we alter the tree 651 */ 652 err = ext2_alloc_branch(inode, indirect_blks, &count, goal, 653 offsets + (partial - chain), partial); 654 655 if (err) { 656 mutex_unlock(&ei->truncate_mutex); 657 goto cleanup; 658 } 659 660 if (ext2_use_xip(inode->i_sb)) { 661 /* 662 * we need to clear the block 663 */ 664 err = ext2_clear_xip_target (inode, 665 le32_to_cpu(chain[depth-1].key)); 666 if (err) { 667 mutex_unlock(&ei->truncate_mutex); 668 goto cleanup; 669 } 670 } 671 672 ext2_splice_branch(inode, iblock, partial, indirect_blks, count); 673 mutex_unlock(&ei->truncate_mutex); 674 set_buffer_new(bh_result); 675 got_it: 676 map_bh(bh_result, inode->i_sb, le32_to_cpu(chain[depth-1].key)); 677 if (count > blocks_to_boundary) 678 set_buffer_boundary(bh_result); 679 err = count; 680 /* Clean up and exit */ 681 partial = chain + depth - 1; /* the whole chain */ 682 cleanup: 683 while (partial > chain) { 684 brelse(partial->bh); 685 partial--; 686 } 687 return err; 688 changed: 689 while (partial > chain) { 690 brelse(partial->bh); 691 partial--; 692 } 693 goto reread; 694 } 695 696 int ext2_get_block(struct inode *inode, sector_t iblock, struct buffer_head *bh_result, int create) 697 { 698 unsigned max_blocks = bh_result->b_size >> inode->i_blkbits; 699 int ret = ext2_get_blocks(inode, iblock, max_blocks, 700 bh_result, create); 701 if (ret > 0) { 702 bh_result->b_size = (ret << inode->i_blkbits); 703 ret = 0; 704 } 705 return ret; 706 707 } 708 709 int ext2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, 710 u64 start, u64 len) 711 { 712 return generic_block_fiemap(inode, fieinfo, start, len, 713 ext2_get_block); 714 } 715 716 static int ext2_writepage(struct page *page, struct writeback_control *wbc) 717 { 718 return block_write_full_page(page, ext2_get_block, wbc); 719 } 720 721 static int ext2_readpage(struct file *file, struct page *page) 722 { 723 return mpage_readpage(page, ext2_get_block); 724 } 725 726 static int 727 ext2_readpages(struct file *file, struct address_space *mapping, 728 struct list_head *pages, unsigned nr_pages) 729 { 730 return mpage_readpages(mapping, pages, nr_pages, ext2_get_block); 731 } 732 733 int __ext2_write_begin(struct file *file, struct address_space *mapping, 734 loff_t pos, unsigned len, unsigned flags, 735 struct page **pagep, void **fsdata) 736 { 737 return block_write_begin(file, mapping, pos, len, flags, pagep, fsdata, 738 ext2_get_block); 739 } 740 741 static int 742 ext2_write_begin(struct file *file, struct address_space *mapping, 743 loff_t pos, unsigned len, unsigned flags, 744 struct page **pagep, void **fsdata) 745 { 746 *pagep = NULL; 747 return __ext2_write_begin(file, mapping, pos, len, flags, pagep,fsdata); 748 } 749 750 static int 751 ext2_nobh_write_begin(struct file *file, struct address_space *mapping, 752 loff_t pos, unsigned len, unsigned flags, 753 struct page **pagep, void **fsdata) 754 { 755 /* 756 * Dir-in-pagecache still uses ext2_write_begin. Would have to rework 757 * directory handling code to pass around offsets rather than struct 758 * pages in order to make this work easily. 759 */ 760 return nobh_write_begin(file, mapping, pos, len, flags, pagep, fsdata, 761 ext2_get_block); 762 } 763 764 static int ext2_nobh_writepage(struct page *page, 765 struct writeback_control *wbc) 766 { 767 return nobh_writepage(page, ext2_get_block, wbc); 768 } 769 770 static sector_t ext2_bmap(struct address_space *mapping, sector_t block) 771 { 772 return generic_block_bmap(mapping,block,ext2_get_block); 773 } 774 775 static ssize_t 776 ext2_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov, 777 loff_t offset, unsigned long nr_segs) 778 { 779 struct file *file = iocb->ki_filp; 780 struct inode *inode = file->f_mapping->host; 781 782 return blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev, iov, 783 offset, nr_segs, ext2_get_block, NULL); 784 } 785 786 static int 787 ext2_writepages(struct address_space *mapping, struct writeback_control *wbc) 788 { 789 return mpage_writepages(mapping, wbc, ext2_get_block); 790 } 791 792 const struct address_space_operations ext2_aops = { 793 .readpage = ext2_readpage, 794 .readpages = ext2_readpages, 795 .writepage = ext2_writepage, 796 .sync_page = block_sync_page, 797 .write_begin = ext2_write_begin, 798 .write_end = generic_write_end, 799 .bmap = ext2_bmap, 800 .direct_IO = ext2_direct_IO, 801 .writepages = ext2_writepages, 802 .migratepage = buffer_migrate_page, 803 .is_partially_uptodate = block_is_partially_uptodate, 804 }; 805 806 const struct address_space_operations ext2_aops_xip = { 807 .bmap = ext2_bmap, 808 .get_xip_mem = ext2_get_xip_mem, 809 }; 810 811 const struct address_space_operations ext2_nobh_aops = { 812 .readpage = ext2_readpage, 813 .readpages = ext2_readpages, 814 .writepage = ext2_nobh_writepage, 815 .sync_page = block_sync_page, 816 .write_begin = ext2_nobh_write_begin, 817 .write_end = nobh_write_end, 818 .bmap = ext2_bmap, 819 .direct_IO = ext2_direct_IO, 820 .writepages = ext2_writepages, 821 .migratepage = buffer_migrate_page, 822 }; 823 824 /* 825 * Probably it should be a library function... search for first non-zero word 826 * or memcmp with zero_page, whatever is better for particular architecture. 827 * Linus? 828 */ 829 static inline int all_zeroes(__le32 *p, __le32 *q) 830 { 831 while (p < q) 832 if (*p++) 833 return 0; 834 return 1; 835 } 836 837 /** 838 * ext2_find_shared - find the indirect blocks for partial truncation. 839 * @inode: inode in question 840 * @depth: depth of the affected branch 841 * @offsets: offsets of pointers in that branch (see ext2_block_to_path) 842 * @chain: place to store the pointers to partial indirect blocks 843 * @top: place to the (detached) top of branch 844 * 845 * This is a helper function used by ext2_truncate(). 846 * 847 * When we do truncate() we may have to clean the ends of several indirect 848 * blocks but leave the blocks themselves alive. Block is partially 849 * truncated if some data below the new i_size is refered from it (and 850 * it is on the path to the first completely truncated data block, indeed). 851 * We have to free the top of that path along with everything to the right 852 * of the path. Since no allocation past the truncation point is possible 853 * until ext2_truncate() finishes, we may safely do the latter, but top 854 * of branch may require special attention - pageout below the truncation 855 * point might try to populate it. 856 * 857 * We atomically detach the top of branch from the tree, store the block 858 * number of its root in *@top, pointers to buffer_heads of partially 859 * truncated blocks - in @chain[].bh and pointers to their last elements 860 * that should not be removed - in @chain[].p. Return value is the pointer 861 * to last filled element of @chain. 862 * 863 * The work left to caller to do the actual freeing of subtrees: 864 * a) free the subtree starting from *@top 865 * b) free the subtrees whose roots are stored in 866 * (@chain[i].p+1 .. end of @chain[i].bh->b_data) 867 * c) free the subtrees growing from the inode past the @chain[0].p 868 * (no partially truncated stuff there). 869 */ 870 871 static Indirect *ext2_find_shared(struct inode *inode, 872 int depth, 873 int offsets[4], 874 Indirect chain[4], 875 __le32 *top) 876 { 877 Indirect *partial, *p; 878 int k, err; 879 880 *top = 0; 881 for (k = depth; k > 1 && !offsets[k-1]; k--) 882 ; 883 partial = ext2_get_branch(inode, k, offsets, chain, &err); 884 if (!partial) 885 partial = chain + k-1; 886 /* 887 * If the branch acquired continuation since we've looked at it - 888 * fine, it should all survive and (new) top doesn't belong to us. 889 */ 890 write_lock(&EXT2_I(inode)->i_meta_lock); 891 if (!partial->key && *partial->p) { 892 write_unlock(&EXT2_I(inode)->i_meta_lock); 893 goto no_top; 894 } 895 for (p=partial; p>chain && all_zeroes((__le32*)p->bh->b_data,p->p); p--) 896 ; 897 /* 898 * OK, we've found the last block that must survive. The rest of our 899 * branch should be detached before unlocking. However, if that rest 900 * of branch is all ours and does not grow immediately from the inode 901 * it's easier to cheat and just decrement partial->p. 902 */ 903 if (p == chain + k - 1 && p > chain) { 904 p->p--; 905 } else { 906 *top = *p->p; 907 *p->p = 0; 908 } 909 write_unlock(&EXT2_I(inode)->i_meta_lock); 910 911 while(partial > p) 912 { 913 brelse(partial->bh); 914 partial--; 915 } 916 no_top: 917 return partial; 918 } 919 920 /** 921 * ext2_free_data - free a list of data blocks 922 * @inode: inode we are dealing with 923 * @p: array of block numbers 924 * @q: points immediately past the end of array 925 * 926 * We are freeing all blocks refered from that array (numbers are 927 * stored as little-endian 32-bit) and updating @inode->i_blocks 928 * appropriately. 929 */ 930 static inline void ext2_free_data(struct inode *inode, __le32 *p, __le32 *q) 931 { 932 unsigned long block_to_free = 0, count = 0; 933 unsigned long nr; 934 935 for ( ; p < q ; p++) { 936 nr = le32_to_cpu(*p); 937 if (nr) { 938 *p = 0; 939 /* accumulate blocks to free if they're contiguous */ 940 if (count == 0) 941 goto free_this; 942 else if (block_to_free == nr - count) 943 count++; 944 else { 945 mark_inode_dirty(inode); 946 ext2_free_blocks (inode, block_to_free, count); 947 free_this: 948 block_to_free = nr; 949 count = 1; 950 } 951 } 952 } 953 if (count > 0) { 954 mark_inode_dirty(inode); 955 ext2_free_blocks (inode, block_to_free, count); 956 } 957 } 958 959 /** 960 * ext2_free_branches - free an array of branches 961 * @inode: inode we are dealing with 962 * @p: array of block numbers 963 * @q: pointer immediately past the end of array 964 * @depth: depth of the branches to free 965 * 966 * We are freeing all blocks refered from these branches (numbers are 967 * stored as little-endian 32-bit) and updating @inode->i_blocks 968 * appropriately. 969 */ 970 static void ext2_free_branches(struct inode *inode, __le32 *p, __le32 *q, int depth) 971 { 972 struct buffer_head * bh; 973 unsigned long nr; 974 975 if (depth--) { 976 int addr_per_block = EXT2_ADDR_PER_BLOCK(inode->i_sb); 977 for ( ; p < q ; p++) { 978 nr = le32_to_cpu(*p); 979 if (!nr) 980 continue; 981 *p = 0; 982 bh = sb_bread(inode->i_sb, nr); 983 /* 984 * A read failure? Report error and clear slot 985 * (should be rare). 986 */ 987 if (!bh) { 988 ext2_error(inode->i_sb, "ext2_free_branches", 989 "Read failure, inode=%ld, block=%ld", 990 inode->i_ino, nr); 991 continue; 992 } 993 ext2_free_branches(inode, 994 (__le32*)bh->b_data, 995 (__le32*)bh->b_data + addr_per_block, 996 depth); 997 bforget(bh); 998 ext2_free_blocks(inode, nr, 1); 999 mark_inode_dirty(inode); 1000 } 1001 } else 1002 ext2_free_data(inode, p, q); 1003 } 1004 1005 void ext2_truncate(struct inode *inode) 1006 { 1007 __le32 *i_data = EXT2_I(inode)->i_data; 1008 struct ext2_inode_info *ei = EXT2_I(inode); 1009 int addr_per_block = EXT2_ADDR_PER_BLOCK(inode->i_sb); 1010 int offsets[4]; 1011 Indirect chain[4]; 1012 Indirect *partial; 1013 __le32 nr = 0; 1014 int n; 1015 long iblock; 1016 unsigned blocksize; 1017 1018 if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || 1019 S_ISLNK(inode->i_mode))) 1020 return; 1021 if (ext2_inode_is_fast_symlink(inode)) 1022 return; 1023 if (IS_APPEND(inode) || IS_IMMUTABLE(inode)) 1024 return; 1025 1026 blocksize = inode->i_sb->s_blocksize; 1027 iblock = (inode->i_size + blocksize-1) 1028 >> EXT2_BLOCK_SIZE_BITS(inode->i_sb); 1029 1030 if (mapping_is_xip(inode->i_mapping)) 1031 xip_truncate_page(inode->i_mapping, inode->i_size); 1032 else if (test_opt(inode->i_sb, NOBH)) 1033 nobh_truncate_page(inode->i_mapping, 1034 inode->i_size, ext2_get_block); 1035 else 1036 block_truncate_page(inode->i_mapping, 1037 inode->i_size, ext2_get_block); 1038 1039 n = ext2_block_to_path(inode, iblock, offsets, NULL); 1040 if (n == 0) 1041 return; 1042 1043 /* 1044 * From here we block out all ext2_get_block() callers who want to 1045 * modify the block allocation tree. 1046 */ 1047 mutex_lock(&ei->truncate_mutex); 1048 1049 if (n == 1) { 1050 ext2_free_data(inode, i_data+offsets[0], 1051 i_data + EXT2_NDIR_BLOCKS); 1052 goto do_indirects; 1053 } 1054 1055 partial = ext2_find_shared(inode, n, offsets, chain, &nr); 1056 /* Kill the top of shared branch (already detached) */ 1057 if (nr) { 1058 if (partial == chain) 1059 mark_inode_dirty(inode); 1060 else 1061 mark_buffer_dirty_inode(partial->bh, inode); 1062 ext2_free_branches(inode, &nr, &nr+1, (chain+n-1) - partial); 1063 } 1064 /* Clear the ends of indirect blocks on the shared branch */ 1065 while (partial > chain) { 1066 ext2_free_branches(inode, 1067 partial->p + 1, 1068 (__le32*)partial->bh->b_data+addr_per_block, 1069 (chain+n-1) - partial); 1070 mark_buffer_dirty_inode(partial->bh, inode); 1071 brelse (partial->bh); 1072 partial--; 1073 } 1074 do_indirects: 1075 /* Kill the remaining (whole) subtrees */ 1076 switch (offsets[0]) { 1077 default: 1078 nr = i_data[EXT2_IND_BLOCK]; 1079 if (nr) { 1080 i_data[EXT2_IND_BLOCK] = 0; 1081 mark_inode_dirty(inode); 1082 ext2_free_branches(inode, &nr, &nr+1, 1); 1083 } 1084 case EXT2_IND_BLOCK: 1085 nr = i_data[EXT2_DIND_BLOCK]; 1086 if (nr) { 1087 i_data[EXT2_DIND_BLOCK] = 0; 1088 mark_inode_dirty(inode); 1089 ext2_free_branches(inode, &nr, &nr+1, 2); 1090 } 1091 case EXT2_DIND_BLOCK: 1092 nr = i_data[EXT2_TIND_BLOCK]; 1093 if (nr) { 1094 i_data[EXT2_TIND_BLOCK] = 0; 1095 mark_inode_dirty(inode); 1096 ext2_free_branches(inode, &nr, &nr+1, 3); 1097 } 1098 case EXT2_TIND_BLOCK: 1099 ; 1100 } 1101 1102 ext2_discard_reservation(inode); 1103 1104 mutex_unlock(&ei->truncate_mutex); 1105 inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC; 1106 if (inode_needs_sync(inode)) { 1107 sync_mapping_buffers(inode->i_mapping); 1108 ext2_sync_inode (inode); 1109 } else { 1110 mark_inode_dirty(inode); 1111 } 1112 } 1113 1114 static struct ext2_inode *ext2_get_inode(struct super_block *sb, ino_t ino, 1115 struct buffer_head **p) 1116 { 1117 struct buffer_head * bh; 1118 unsigned long block_group; 1119 unsigned long block; 1120 unsigned long offset; 1121 struct ext2_group_desc * gdp; 1122 1123 *p = NULL; 1124 if ((ino != EXT2_ROOT_INO && ino < EXT2_FIRST_INO(sb)) || 1125 ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count)) 1126 goto Einval; 1127 1128 block_group = (ino - 1) / EXT2_INODES_PER_GROUP(sb); 1129 gdp = ext2_get_group_desc(sb, block_group, NULL); 1130 if (!gdp) 1131 goto Egdp; 1132 /* 1133 * Figure out the offset within the block group inode table 1134 */ 1135 offset = ((ino - 1) % EXT2_INODES_PER_GROUP(sb)) * EXT2_INODE_SIZE(sb); 1136 block = le32_to_cpu(gdp->bg_inode_table) + 1137 (offset >> EXT2_BLOCK_SIZE_BITS(sb)); 1138 if (!(bh = sb_bread(sb, block))) 1139 goto Eio; 1140 1141 *p = bh; 1142 offset &= (EXT2_BLOCK_SIZE(sb) - 1); 1143 return (struct ext2_inode *) (bh->b_data + offset); 1144 1145 Einval: 1146 ext2_error(sb, "ext2_get_inode", "bad inode number: %lu", 1147 (unsigned long) ino); 1148 return ERR_PTR(-EINVAL); 1149 Eio: 1150 ext2_error(sb, "ext2_get_inode", 1151 "unable to read inode block - inode=%lu, block=%lu", 1152 (unsigned long) ino, block); 1153 Egdp: 1154 return ERR_PTR(-EIO); 1155 } 1156 1157 void ext2_set_inode_flags(struct inode *inode) 1158 { 1159 unsigned int flags = EXT2_I(inode)->i_flags; 1160 1161 inode->i_flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC); 1162 if (flags & EXT2_SYNC_FL) 1163 inode->i_flags |= S_SYNC; 1164 if (flags & EXT2_APPEND_FL) 1165 inode->i_flags |= S_APPEND; 1166 if (flags & EXT2_IMMUTABLE_FL) 1167 inode->i_flags |= S_IMMUTABLE; 1168 if (flags & EXT2_NOATIME_FL) 1169 inode->i_flags |= S_NOATIME; 1170 if (flags & EXT2_DIRSYNC_FL) 1171 inode->i_flags |= S_DIRSYNC; 1172 } 1173 1174 /* Propagate flags from i_flags to EXT2_I(inode)->i_flags */ 1175 void ext2_get_inode_flags(struct ext2_inode_info *ei) 1176 { 1177 unsigned int flags = ei->vfs_inode.i_flags; 1178 1179 ei->i_flags &= ~(EXT2_SYNC_FL|EXT2_APPEND_FL| 1180 EXT2_IMMUTABLE_FL|EXT2_NOATIME_FL|EXT2_DIRSYNC_FL); 1181 if (flags & S_SYNC) 1182 ei->i_flags |= EXT2_SYNC_FL; 1183 if (flags & S_APPEND) 1184 ei->i_flags |= EXT2_APPEND_FL; 1185 if (flags & S_IMMUTABLE) 1186 ei->i_flags |= EXT2_IMMUTABLE_FL; 1187 if (flags & S_NOATIME) 1188 ei->i_flags |= EXT2_NOATIME_FL; 1189 if (flags & S_DIRSYNC) 1190 ei->i_flags |= EXT2_DIRSYNC_FL; 1191 } 1192 1193 struct inode *ext2_iget (struct super_block *sb, unsigned long ino) 1194 { 1195 struct ext2_inode_info *ei; 1196 struct buffer_head * bh; 1197 struct ext2_inode *raw_inode; 1198 struct inode *inode; 1199 long ret = -EIO; 1200 int n; 1201 1202 inode = iget_locked(sb, ino); 1203 if (!inode) 1204 return ERR_PTR(-ENOMEM); 1205 if (!(inode->i_state & I_NEW)) 1206 return inode; 1207 1208 ei = EXT2_I(inode); 1209 #ifdef CONFIG_EXT2_FS_POSIX_ACL 1210 ei->i_acl = EXT2_ACL_NOT_CACHED; 1211 ei->i_default_acl = EXT2_ACL_NOT_CACHED; 1212 #endif 1213 ei->i_block_alloc_info = NULL; 1214 1215 raw_inode = ext2_get_inode(inode->i_sb, ino, &bh); 1216 if (IS_ERR(raw_inode)) { 1217 ret = PTR_ERR(raw_inode); 1218 goto bad_inode; 1219 } 1220 1221 inode->i_mode = le16_to_cpu(raw_inode->i_mode); 1222 inode->i_uid = (uid_t)le16_to_cpu(raw_inode->i_uid_low); 1223 inode->i_gid = (gid_t)le16_to_cpu(raw_inode->i_gid_low); 1224 if (!(test_opt (inode->i_sb, NO_UID32))) { 1225 inode->i_uid |= le16_to_cpu(raw_inode->i_uid_high) << 16; 1226 inode->i_gid |= le16_to_cpu(raw_inode->i_gid_high) << 16; 1227 } 1228 inode->i_nlink = le16_to_cpu(raw_inode->i_links_count); 1229 inode->i_size = le32_to_cpu(raw_inode->i_size); 1230 inode->i_atime.tv_sec = (signed)le32_to_cpu(raw_inode->i_atime); 1231 inode->i_ctime.tv_sec = (signed)le32_to_cpu(raw_inode->i_ctime); 1232 inode->i_mtime.tv_sec = (signed)le32_to_cpu(raw_inode->i_mtime); 1233 inode->i_atime.tv_nsec = inode->i_mtime.tv_nsec = inode->i_ctime.tv_nsec = 0; 1234 ei->i_dtime = le32_to_cpu(raw_inode->i_dtime); 1235 /* We now have enough fields to check if the inode was active or not. 1236 * This is needed because nfsd might try to access dead inodes 1237 * the test is that same one that e2fsck uses 1238 * NeilBrown 1999oct15 1239 */ 1240 if (inode->i_nlink == 0 && (inode->i_mode == 0 || ei->i_dtime)) { 1241 /* this inode is deleted */ 1242 brelse (bh); 1243 ret = -ESTALE; 1244 goto bad_inode; 1245 } 1246 inode->i_blocks = le32_to_cpu(raw_inode->i_blocks); 1247 ei->i_flags = le32_to_cpu(raw_inode->i_flags); 1248 ei->i_faddr = le32_to_cpu(raw_inode->i_faddr); 1249 ei->i_frag_no = raw_inode->i_frag; 1250 ei->i_frag_size = raw_inode->i_fsize; 1251 ei->i_file_acl = le32_to_cpu(raw_inode->i_file_acl); 1252 ei->i_dir_acl = 0; 1253 if (S_ISREG(inode->i_mode)) 1254 inode->i_size |= ((__u64)le32_to_cpu(raw_inode->i_size_high)) << 32; 1255 else 1256 ei->i_dir_acl = le32_to_cpu(raw_inode->i_dir_acl); 1257 ei->i_dtime = 0; 1258 inode->i_generation = le32_to_cpu(raw_inode->i_generation); 1259 ei->i_state = 0; 1260 ei->i_block_group = (ino - 1) / EXT2_INODES_PER_GROUP(inode->i_sb); 1261 ei->i_dir_start_lookup = 0; 1262 1263 /* 1264 * NOTE! The in-memory inode i_data array is in little-endian order 1265 * even on big-endian machines: we do NOT byteswap the block numbers! 1266 */ 1267 for (n = 0; n < EXT2_N_BLOCKS; n++) 1268 ei->i_data[n] = raw_inode->i_block[n]; 1269 1270 if (S_ISREG(inode->i_mode)) { 1271 inode->i_op = &ext2_file_inode_operations; 1272 if (ext2_use_xip(inode->i_sb)) { 1273 inode->i_mapping->a_ops = &ext2_aops_xip; 1274 inode->i_fop = &ext2_xip_file_operations; 1275 } else if (test_opt(inode->i_sb, NOBH)) { 1276 inode->i_mapping->a_ops = &ext2_nobh_aops; 1277 inode->i_fop = &ext2_file_operations; 1278 } else { 1279 inode->i_mapping->a_ops = &ext2_aops; 1280 inode->i_fop = &ext2_file_operations; 1281 } 1282 } else if (S_ISDIR(inode->i_mode)) { 1283 inode->i_op = &ext2_dir_inode_operations; 1284 inode->i_fop = &ext2_dir_operations; 1285 if (test_opt(inode->i_sb, NOBH)) 1286 inode->i_mapping->a_ops = &ext2_nobh_aops; 1287 else 1288 inode->i_mapping->a_ops = &ext2_aops; 1289 } else if (S_ISLNK(inode->i_mode)) { 1290 if (ext2_inode_is_fast_symlink(inode)) { 1291 inode->i_op = &ext2_fast_symlink_inode_operations; 1292 nd_terminate_link(ei->i_data, inode->i_size, 1293 sizeof(ei->i_data) - 1); 1294 } else { 1295 inode->i_op = &ext2_symlink_inode_operations; 1296 if (test_opt(inode->i_sb, NOBH)) 1297 inode->i_mapping->a_ops = &ext2_nobh_aops; 1298 else 1299 inode->i_mapping->a_ops = &ext2_aops; 1300 } 1301 } else { 1302 inode->i_op = &ext2_special_inode_operations; 1303 if (raw_inode->i_block[0]) 1304 init_special_inode(inode, inode->i_mode, 1305 old_decode_dev(le32_to_cpu(raw_inode->i_block[0]))); 1306 else 1307 init_special_inode(inode, inode->i_mode, 1308 new_decode_dev(le32_to_cpu(raw_inode->i_block[1]))); 1309 } 1310 brelse (bh); 1311 ext2_set_inode_flags(inode); 1312 unlock_new_inode(inode); 1313 return inode; 1314 1315 bad_inode: 1316 iget_failed(inode); 1317 return ERR_PTR(ret); 1318 } 1319 1320 static int ext2_update_inode(struct inode * inode, int do_sync) 1321 { 1322 struct ext2_inode_info *ei = EXT2_I(inode); 1323 struct super_block *sb = inode->i_sb; 1324 ino_t ino = inode->i_ino; 1325 uid_t uid = inode->i_uid; 1326 gid_t gid = inode->i_gid; 1327 struct buffer_head * bh; 1328 struct ext2_inode * raw_inode = ext2_get_inode(sb, ino, &bh); 1329 int n; 1330 int err = 0; 1331 1332 if (IS_ERR(raw_inode)) 1333 return -EIO; 1334 1335 /* For fields not not tracking in the in-memory inode, 1336 * initialise them to zero for new inodes. */ 1337 if (ei->i_state & EXT2_STATE_NEW) 1338 memset(raw_inode, 0, EXT2_SB(sb)->s_inode_size); 1339 1340 ext2_get_inode_flags(ei); 1341 raw_inode->i_mode = cpu_to_le16(inode->i_mode); 1342 if (!(test_opt(sb, NO_UID32))) { 1343 raw_inode->i_uid_low = cpu_to_le16(low_16_bits(uid)); 1344 raw_inode->i_gid_low = cpu_to_le16(low_16_bits(gid)); 1345 /* 1346 * Fix up interoperability with old kernels. Otherwise, old inodes get 1347 * re-used with the upper 16 bits of the uid/gid intact 1348 */ 1349 if (!ei->i_dtime) { 1350 raw_inode->i_uid_high = cpu_to_le16(high_16_bits(uid)); 1351 raw_inode->i_gid_high = cpu_to_le16(high_16_bits(gid)); 1352 } else { 1353 raw_inode->i_uid_high = 0; 1354 raw_inode->i_gid_high = 0; 1355 } 1356 } else { 1357 raw_inode->i_uid_low = cpu_to_le16(fs_high2lowuid(uid)); 1358 raw_inode->i_gid_low = cpu_to_le16(fs_high2lowgid(gid)); 1359 raw_inode->i_uid_high = 0; 1360 raw_inode->i_gid_high = 0; 1361 } 1362 raw_inode->i_links_count = cpu_to_le16(inode->i_nlink); 1363 raw_inode->i_size = cpu_to_le32(inode->i_size); 1364 raw_inode->i_atime = cpu_to_le32(inode->i_atime.tv_sec); 1365 raw_inode->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec); 1366 raw_inode->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec); 1367 1368 raw_inode->i_blocks = cpu_to_le32(inode->i_blocks); 1369 raw_inode->i_dtime = cpu_to_le32(ei->i_dtime); 1370 raw_inode->i_flags = cpu_to_le32(ei->i_flags); 1371 raw_inode->i_faddr = cpu_to_le32(ei->i_faddr); 1372 raw_inode->i_frag = ei->i_frag_no; 1373 raw_inode->i_fsize = ei->i_frag_size; 1374 raw_inode->i_file_acl = cpu_to_le32(ei->i_file_acl); 1375 if (!S_ISREG(inode->i_mode)) 1376 raw_inode->i_dir_acl = cpu_to_le32(ei->i_dir_acl); 1377 else { 1378 raw_inode->i_size_high = cpu_to_le32(inode->i_size >> 32); 1379 if (inode->i_size > 0x7fffffffULL) { 1380 if (!EXT2_HAS_RO_COMPAT_FEATURE(sb, 1381 EXT2_FEATURE_RO_COMPAT_LARGE_FILE) || 1382 EXT2_SB(sb)->s_es->s_rev_level == 1383 cpu_to_le32(EXT2_GOOD_OLD_REV)) { 1384 /* If this is the first large file 1385 * created, add a flag to the superblock. 1386 */ 1387 lock_kernel(); 1388 ext2_update_dynamic_rev(sb); 1389 EXT2_SET_RO_COMPAT_FEATURE(sb, 1390 EXT2_FEATURE_RO_COMPAT_LARGE_FILE); 1391 unlock_kernel(); 1392 ext2_write_super(sb); 1393 } 1394 } 1395 } 1396 1397 raw_inode->i_generation = cpu_to_le32(inode->i_generation); 1398 if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) { 1399 if (old_valid_dev(inode->i_rdev)) { 1400 raw_inode->i_block[0] = 1401 cpu_to_le32(old_encode_dev(inode->i_rdev)); 1402 raw_inode->i_block[1] = 0; 1403 } else { 1404 raw_inode->i_block[0] = 0; 1405 raw_inode->i_block[1] = 1406 cpu_to_le32(new_encode_dev(inode->i_rdev)); 1407 raw_inode->i_block[2] = 0; 1408 } 1409 } else for (n = 0; n < EXT2_N_BLOCKS; n++) 1410 raw_inode->i_block[n] = ei->i_data[n]; 1411 mark_buffer_dirty(bh); 1412 if (do_sync) { 1413 sync_dirty_buffer(bh); 1414 if (buffer_req(bh) && !buffer_uptodate(bh)) { 1415 printk ("IO error syncing ext2 inode [%s:%08lx]\n", 1416 sb->s_id, (unsigned long) ino); 1417 err = -EIO; 1418 } 1419 } 1420 ei->i_state &= ~EXT2_STATE_NEW; 1421 brelse (bh); 1422 return err; 1423 } 1424 1425 int ext2_write_inode(struct inode *inode, int wait) 1426 { 1427 return ext2_update_inode(inode, wait); 1428 } 1429 1430 int ext2_sync_inode(struct inode *inode) 1431 { 1432 struct writeback_control wbc = { 1433 .sync_mode = WB_SYNC_ALL, 1434 .nr_to_write = 0, /* sys_fsync did this */ 1435 }; 1436 return sync_inode(inode, &wbc); 1437 } 1438 1439 int ext2_setattr(struct dentry *dentry, struct iattr *iattr) 1440 { 1441 struct inode *inode = dentry->d_inode; 1442 int error; 1443 1444 error = inode_change_ok(inode, iattr); 1445 if (error) 1446 return error; 1447 if ((iattr->ia_valid & ATTR_UID && iattr->ia_uid != inode->i_uid) || 1448 (iattr->ia_valid & ATTR_GID && iattr->ia_gid != inode->i_gid)) { 1449 error = DQUOT_TRANSFER(inode, iattr) ? -EDQUOT : 0; 1450 if (error) 1451 return error; 1452 } 1453 error = inode_setattr(inode, iattr); 1454 if (!error && (iattr->ia_valid & ATTR_MODE)) 1455 error = ext2_acl_chmod(inode); 1456 return error; 1457 } 1458