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/time.h> 26 #include <linux/highuid.h> 27 #include <linux/pagemap.h> 28 #include <linux/quotaops.h> 29 #include <linux/writeback.h> 30 #include <linux/buffer_head.h> 31 #include <linux/mpage.h> 32 #include <linux/fiemap.h> 33 #include <linux/namei.h> 34 #include "ext2.h" 35 #include "acl.h" 36 #include "xip.h" 37 38 static int __ext2_write_inode(struct inode *inode, int do_sync); 39 40 /* 41 * Test whether an inode is a fast symlink. 42 */ 43 static inline int ext2_inode_is_fast_symlink(struct inode *inode) 44 { 45 int ea_blocks = EXT2_I(inode)->i_file_acl ? 46 (inode->i_sb->s_blocksize >> 9) : 0; 47 48 return (S_ISLNK(inode->i_mode) && 49 inode->i_blocks - ea_blocks == 0); 50 } 51 52 static void ext2_truncate_blocks(struct inode *inode, loff_t offset); 53 54 static void ext2_write_failed(struct address_space *mapping, loff_t to) 55 { 56 struct inode *inode = mapping->host; 57 58 if (to > inode->i_size) { 59 truncate_pagecache(inode, to, inode->i_size); 60 ext2_truncate_blocks(inode, inode->i_size); 61 } 62 } 63 64 /* 65 * Called at the last iput() if i_nlink is zero. 66 */ 67 void ext2_evict_inode(struct inode * inode) 68 { 69 struct ext2_block_alloc_info *rsv; 70 int want_delete = 0; 71 72 if (!inode->i_nlink && !is_bad_inode(inode)) { 73 want_delete = 1; 74 dquot_initialize(inode); 75 } else { 76 dquot_drop(inode); 77 } 78 79 truncate_inode_pages(&inode->i_data, 0); 80 81 if (want_delete) { 82 sb_start_intwrite(inode->i_sb); 83 /* set dtime */ 84 EXT2_I(inode)->i_dtime = get_seconds(); 85 mark_inode_dirty(inode); 86 __ext2_write_inode(inode, inode_needs_sync(inode)); 87 /* truncate to 0 */ 88 inode->i_size = 0; 89 if (inode->i_blocks) 90 ext2_truncate_blocks(inode, 0); 91 } 92 93 invalidate_inode_buffers(inode); 94 clear_inode(inode); 95 96 ext2_discard_reservation(inode); 97 rsv = EXT2_I(inode)->i_block_alloc_info; 98 EXT2_I(inode)->i_block_alloc_info = NULL; 99 if (unlikely(rsv)) 100 kfree(rsv); 101 102 if (want_delete) { 103 ext2_free_inode(inode); 104 sb_end_intwrite(inode->i_sb); 105 } 106 } 107 108 typedef struct { 109 __le32 *p; 110 __le32 key; 111 struct buffer_head *bh; 112 } Indirect; 113 114 static inline void add_chain(Indirect *p, struct buffer_head *bh, __le32 *v) 115 { 116 p->key = *(p->p = v); 117 p->bh = bh; 118 } 119 120 static inline int verify_chain(Indirect *from, Indirect *to) 121 { 122 while (from <= to && from->key == *from->p) 123 from++; 124 return (from > to); 125 } 126 127 /** 128 * ext2_block_to_path - parse the block number into array of offsets 129 * @inode: inode in question (we are only interested in its superblock) 130 * @i_block: block number to be parsed 131 * @offsets: array to store the offsets in 132 * @boundary: set this non-zero if the referred-to block is likely to be 133 * followed (on disk) by an indirect block. 134 * To store the locations of file's data ext2 uses a data structure common 135 * for UNIX filesystems - tree of pointers anchored in the inode, with 136 * data blocks at leaves and indirect blocks in intermediate nodes. 137 * This function translates the block number into path in that tree - 138 * return value is the path length and @offsets[n] is the offset of 139 * pointer to (n+1)th node in the nth one. If @block is out of range 140 * (negative or too large) warning is printed and zero returned. 141 * 142 * Note: function doesn't find node addresses, so no IO is needed. All 143 * we need to know is the capacity of indirect blocks (taken from the 144 * inode->i_sb). 145 */ 146 147 /* 148 * Portability note: the last comparison (check that we fit into triple 149 * indirect block) is spelled differently, because otherwise on an 150 * architecture with 32-bit longs and 8Kb pages we might get into trouble 151 * if our filesystem had 8Kb blocks. We might use long long, but that would 152 * kill us on x86. Oh, well, at least the sign propagation does not matter - 153 * i_block would have to be negative in the very beginning, so we would not 154 * get there at all. 155 */ 156 157 static int ext2_block_to_path(struct inode *inode, 158 long i_block, int offsets[4], int *boundary) 159 { 160 int ptrs = EXT2_ADDR_PER_BLOCK(inode->i_sb); 161 int ptrs_bits = EXT2_ADDR_PER_BLOCK_BITS(inode->i_sb); 162 const long direct_blocks = EXT2_NDIR_BLOCKS, 163 indirect_blocks = ptrs, 164 double_blocks = (1 << (ptrs_bits * 2)); 165 int n = 0; 166 int final = 0; 167 168 if (i_block < 0) { 169 ext2_msg(inode->i_sb, KERN_WARNING, 170 "warning: %s: block < 0", __func__); 171 } else if (i_block < direct_blocks) { 172 offsets[n++] = i_block; 173 final = direct_blocks; 174 } else if ( (i_block -= direct_blocks) < indirect_blocks) { 175 offsets[n++] = EXT2_IND_BLOCK; 176 offsets[n++] = i_block; 177 final = ptrs; 178 } else if ((i_block -= indirect_blocks) < double_blocks) { 179 offsets[n++] = EXT2_DIND_BLOCK; 180 offsets[n++] = i_block >> ptrs_bits; 181 offsets[n++] = i_block & (ptrs - 1); 182 final = ptrs; 183 } else if (((i_block -= double_blocks) >> (ptrs_bits * 2)) < ptrs) { 184 offsets[n++] = EXT2_TIND_BLOCK; 185 offsets[n++] = i_block >> (ptrs_bits * 2); 186 offsets[n++] = (i_block >> ptrs_bits) & (ptrs - 1); 187 offsets[n++] = i_block & (ptrs - 1); 188 final = ptrs; 189 } else { 190 ext2_msg(inode->i_sb, KERN_WARNING, 191 "warning: %s: block is too big", __func__); 192 } 193 if (boundary) 194 *boundary = final - 1 - (i_block & (ptrs - 1)); 195 196 return n; 197 } 198 199 /** 200 * ext2_get_branch - read the chain of indirect blocks leading to data 201 * @inode: inode in question 202 * @depth: depth of the chain (1 - direct pointer, etc.) 203 * @offsets: offsets of pointers in inode/indirect blocks 204 * @chain: place to store the result 205 * @err: here we store the error value 206 * 207 * Function fills the array of triples <key, p, bh> and returns %NULL 208 * if everything went OK or the pointer to the last filled triple 209 * (incomplete one) otherwise. Upon the return chain[i].key contains 210 * the number of (i+1)-th block in the chain (as it is stored in memory, 211 * i.e. little-endian 32-bit), chain[i].p contains the address of that 212 * number (it points into struct inode for i==0 and into the bh->b_data 213 * for i>0) and chain[i].bh points to the buffer_head of i-th indirect 214 * block for i>0 and NULL for i==0. In other words, it holds the block 215 * numbers of the chain, addresses they were taken from (and where we can 216 * verify that chain did not change) and buffer_heads hosting these 217 * numbers. 218 * 219 * Function stops when it stumbles upon zero pointer (absent block) 220 * (pointer to last triple returned, *@err == 0) 221 * or when it gets an IO error reading an indirect block 222 * (ditto, *@err == -EIO) 223 * or when it notices that chain had been changed while it was reading 224 * (ditto, *@err == -EAGAIN) 225 * or when it reads all @depth-1 indirect blocks successfully and finds 226 * the whole chain, all way to the data (returns %NULL, *err == 0). 227 */ 228 static Indirect *ext2_get_branch(struct inode *inode, 229 int depth, 230 int *offsets, 231 Indirect chain[4], 232 int *err) 233 { 234 struct super_block *sb = inode->i_sb; 235 Indirect *p = chain; 236 struct buffer_head *bh; 237 238 *err = 0; 239 /* i_data is not going away, no lock needed */ 240 add_chain (chain, NULL, EXT2_I(inode)->i_data + *offsets); 241 if (!p->key) 242 goto no_block; 243 while (--depth) { 244 bh = sb_bread(sb, le32_to_cpu(p->key)); 245 if (!bh) 246 goto failure; 247 read_lock(&EXT2_I(inode)->i_meta_lock); 248 if (!verify_chain(chain, p)) 249 goto changed; 250 add_chain(++p, bh, (__le32*)bh->b_data + *++offsets); 251 read_unlock(&EXT2_I(inode)->i_meta_lock); 252 if (!p->key) 253 goto no_block; 254 } 255 return NULL; 256 257 changed: 258 read_unlock(&EXT2_I(inode)->i_meta_lock); 259 brelse(bh); 260 *err = -EAGAIN; 261 goto no_block; 262 failure: 263 *err = -EIO; 264 no_block: 265 return p; 266 } 267 268 /** 269 * ext2_find_near - find a place for allocation with sufficient locality 270 * @inode: owner 271 * @ind: descriptor of indirect block. 272 * 273 * This function returns the preferred place for block allocation. 274 * It is used when heuristic for sequential allocation fails. 275 * Rules are: 276 * + if there is a block to the left of our position - allocate near it. 277 * + if pointer will live in indirect block - allocate near that block. 278 * + if pointer will live in inode - allocate in the same cylinder group. 279 * 280 * In the latter case we colour the starting block by the callers PID to 281 * prevent it from clashing with concurrent allocations for a different inode 282 * in the same block group. The PID is used here so that functionally related 283 * files will be close-by on-disk. 284 * 285 * Caller must make sure that @ind is valid and will stay that way. 286 */ 287 288 static ext2_fsblk_t ext2_find_near(struct inode *inode, Indirect *ind) 289 { 290 struct ext2_inode_info *ei = EXT2_I(inode); 291 __le32 *start = ind->bh ? (__le32 *) ind->bh->b_data : ei->i_data; 292 __le32 *p; 293 ext2_fsblk_t bg_start; 294 ext2_fsblk_t colour; 295 296 /* Try to find previous block */ 297 for (p = ind->p - 1; p >= start; p--) 298 if (*p) 299 return le32_to_cpu(*p); 300 301 /* No such thing, so let's try location of indirect block */ 302 if (ind->bh) 303 return ind->bh->b_blocknr; 304 305 /* 306 * It is going to be referred from inode itself? OK, just put it into 307 * the same cylinder group then. 308 */ 309 bg_start = ext2_group_first_block_no(inode->i_sb, ei->i_block_group); 310 colour = (current->pid % 16) * 311 (EXT2_BLOCKS_PER_GROUP(inode->i_sb) / 16); 312 return bg_start + colour; 313 } 314 315 /** 316 * ext2_find_goal - find a preferred place for allocation. 317 * @inode: owner 318 * @block: block we want 319 * @partial: pointer to the last triple within a chain 320 * 321 * Returns preferred place for a block (the goal). 322 */ 323 324 static inline ext2_fsblk_t ext2_find_goal(struct inode *inode, long block, 325 Indirect *partial) 326 { 327 struct ext2_block_alloc_info *block_i; 328 329 block_i = EXT2_I(inode)->i_block_alloc_info; 330 331 /* 332 * try the heuristic for sequential allocation, 333 * failing that at least try to get decent locality. 334 */ 335 if (block_i && (block == block_i->last_alloc_logical_block + 1) 336 && (block_i->last_alloc_physical_block != 0)) { 337 return block_i->last_alloc_physical_block + 1; 338 } 339 340 return ext2_find_near(inode, partial); 341 } 342 343 /** 344 * ext2_blks_to_allocate: Look up the block map and count the number 345 * of direct blocks need to be allocated for the given branch. 346 * 347 * @branch: chain of indirect blocks 348 * @k: number of blocks need for indirect blocks 349 * @blks: number of data blocks to be mapped. 350 * @blocks_to_boundary: the offset in the indirect block 351 * 352 * return the total number of blocks to be allocate, including the 353 * direct and indirect blocks. 354 */ 355 static int 356 ext2_blks_to_allocate(Indirect * branch, int k, unsigned long blks, 357 int blocks_to_boundary) 358 { 359 unsigned long count = 0; 360 361 /* 362 * Simple case, [t,d]Indirect block(s) has not allocated yet 363 * then it's clear blocks on that path have not allocated 364 */ 365 if (k > 0) { 366 /* right now don't hanel cross boundary allocation */ 367 if (blks < blocks_to_boundary + 1) 368 count += blks; 369 else 370 count += blocks_to_boundary + 1; 371 return count; 372 } 373 374 count++; 375 while (count < blks && count <= blocks_to_boundary 376 && le32_to_cpu(*(branch[0].p + count)) == 0) { 377 count++; 378 } 379 return count; 380 } 381 382 /** 383 * ext2_alloc_blocks: multiple allocate blocks needed for a branch 384 * @indirect_blks: the number of blocks need to allocate for indirect 385 * blocks 386 * 387 * @new_blocks: on return it will store the new block numbers for 388 * the indirect blocks(if needed) and the first direct block, 389 * @blks: on return it will store the total number of allocated 390 * direct blocks 391 */ 392 static int ext2_alloc_blocks(struct inode *inode, 393 ext2_fsblk_t goal, int indirect_blks, int blks, 394 ext2_fsblk_t new_blocks[4], int *err) 395 { 396 int target, i; 397 unsigned long count = 0; 398 int index = 0; 399 ext2_fsblk_t current_block = 0; 400 int ret = 0; 401 402 /* 403 * Here we try to allocate the requested multiple blocks at once, 404 * on a best-effort basis. 405 * To build a branch, we should allocate blocks for 406 * the indirect blocks(if not allocated yet), and at least 407 * the first direct block of this branch. That's the 408 * minimum number of blocks need to allocate(required) 409 */ 410 target = blks + indirect_blks; 411 412 while (1) { 413 count = target; 414 /* allocating blocks for indirect blocks and direct blocks */ 415 current_block = ext2_new_blocks(inode,goal,&count,err); 416 if (*err) 417 goto failed_out; 418 419 target -= count; 420 /* allocate blocks for indirect blocks */ 421 while (index < indirect_blks && count) { 422 new_blocks[index++] = current_block++; 423 count--; 424 } 425 426 if (count > 0) 427 break; 428 } 429 430 /* save the new block number for the first direct block */ 431 new_blocks[index] = current_block; 432 433 /* total number of blocks allocated for direct blocks */ 434 ret = count; 435 *err = 0; 436 return ret; 437 failed_out: 438 for (i = 0; i <index; i++) 439 ext2_free_blocks(inode, new_blocks[i], 1); 440 if (index) 441 mark_inode_dirty(inode); 442 return ret; 443 } 444 445 /** 446 * ext2_alloc_branch - allocate and set up a chain of blocks. 447 * @inode: owner 448 * @num: depth of the chain (number of blocks to allocate) 449 * @offsets: offsets (in the blocks) to store the pointers to next. 450 * @branch: place to store the chain in. 451 * 452 * This function allocates @num blocks, zeroes out all but the last one, 453 * links them into chain and (if we are synchronous) writes them to disk. 454 * In other words, it prepares a branch that can be spliced onto the 455 * inode. It stores the information about that chain in the branch[], in 456 * the same format as ext2_get_branch() would do. We are calling it after 457 * we had read the existing part of chain and partial points to the last 458 * triple of that (one with zero ->key). Upon the exit we have the same 459 * picture as after the successful ext2_get_block(), except that in one 460 * place chain is disconnected - *branch->p is still zero (we did not 461 * set the last link), but branch->key contains the number that should 462 * be placed into *branch->p to fill that gap. 463 * 464 * If allocation fails we free all blocks we've allocated (and forget 465 * their buffer_heads) and return the error value the from failed 466 * ext2_alloc_block() (normally -ENOSPC). Otherwise we set the chain 467 * as described above and return 0. 468 */ 469 470 static int ext2_alloc_branch(struct inode *inode, 471 int indirect_blks, int *blks, ext2_fsblk_t goal, 472 int *offsets, Indirect *branch) 473 { 474 int blocksize = inode->i_sb->s_blocksize; 475 int i, n = 0; 476 int err = 0; 477 struct buffer_head *bh; 478 int num; 479 ext2_fsblk_t new_blocks[4]; 480 ext2_fsblk_t current_block; 481 482 num = ext2_alloc_blocks(inode, goal, indirect_blks, 483 *blks, new_blocks, &err); 484 if (err) 485 return err; 486 487 branch[0].key = cpu_to_le32(new_blocks[0]); 488 /* 489 * metadata blocks and data blocks are allocated. 490 */ 491 for (n = 1; n <= indirect_blks; n++) { 492 /* 493 * Get buffer_head for parent block, zero it out 494 * and set the pointer to new one, then send 495 * parent to disk. 496 */ 497 bh = sb_getblk(inode->i_sb, new_blocks[n-1]); 498 if (unlikely(!bh)) { 499 err = -ENOMEM; 500 goto failed; 501 } 502 branch[n].bh = bh; 503 lock_buffer(bh); 504 memset(bh->b_data, 0, blocksize); 505 branch[n].p = (__le32 *) bh->b_data + offsets[n]; 506 branch[n].key = cpu_to_le32(new_blocks[n]); 507 *branch[n].p = branch[n].key; 508 if ( n == indirect_blks) { 509 current_block = new_blocks[n]; 510 /* 511 * End of chain, update the last new metablock of 512 * the chain to point to the new allocated 513 * data blocks numbers 514 */ 515 for (i=1; i < num; i++) 516 *(branch[n].p + i) = cpu_to_le32(++current_block); 517 } 518 set_buffer_uptodate(bh); 519 unlock_buffer(bh); 520 mark_buffer_dirty_inode(bh, inode); 521 /* We used to sync bh here if IS_SYNC(inode). 522 * But we now rely upon generic_write_sync() 523 * and b_inode_buffers. But not for directories. 524 */ 525 if (S_ISDIR(inode->i_mode) && IS_DIRSYNC(inode)) 526 sync_dirty_buffer(bh); 527 } 528 *blks = num; 529 return err; 530 531 failed: 532 for (i = 1; i < n; i++) 533 bforget(branch[i].bh); 534 for (i = 0; i < indirect_blks; i++) 535 ext2_free_blocks(inode, new_blocks[i], 1); 536 ext2_free_blocks(inode, new_blocks[i], num); 537 return err; 538 } 539 540 /** 541 * ext2_splice_branch - splice the allocated branch onto inode. 542 * @inode: owner 543 * @block: (logical) number of block we are adding 544 * @where: location of missing link 545 * @num: number of indirect blocks we are adding 546 * @blks: number of direct blocks we are adding 547 * 548 * This function fills the missing link and does all housekeeping needed in 549 * inode (->i_blocks, etc.). In case of success we end up with the full 550 * chain to new block and return 0. 551 */ 552 static void ext2_splice_branch(struct inode *inode, 553 long block, Indirect *where, int num, int blks) 554 { 555 int i; 556 struct ext2_block_alloc_info *block_i; 557 ext2_fsblk_t current_block; 558 559 block_i = EXT2_I(inode)->i_block_alloc_info; 560 561 /* XXX LOCKING probably should have i_meta_lock ?*/ 562 /* That's it */ 563 564 *where->p = where->key; 565 566 /* 567 * Update the host buffer_head or inode to point to more just allocated 568 * direct blocks blocks 569 */ 570 if (num == 0 && blks > 1) { 571 current_block = le32_to_cpu(where->key) + 1; 572 for (i = 1; i < blks; i++) 573 *(where->p + i ) = cpu_to_le32(current_block++); 574 } 575 576 /* 577 * update the most recently allocated logical & physical block 578 * in i_block_alloc_info, to assist find the proper goal block for next 579 * allocation 580 */ 581 if (block_i) { 582 block_i->last_alloc_logical_block = block + blks - 1; 583 block_i->last_alloc_physical_block = 584 le32_to_cpu(where[num].key) + blks - 1; 585 } 586 587 /* We are done with atomic stuff, now do the rest of housekeeping */ 588 589 /* had we spliced it onto indirect block? */ 590 if (where->bh) 591 mark_buffer_dirty_inode(where->bh, inode); 592 593 inode->i_ctime = CURRENT_TIME_SEC; 594 mark_inode_dirty(inode); 595 } 596 597 /* 598 * Allocation strategy is simple: if we have to allocate something, we will 599 * have to go the whole way to leaf. So let's do it before attaching anything 600 * to tree, set linkage between the newborn blocks, write them if sync is 601 * required, recheck the path, free and repeat if check fails, otherwise 602 * set the last missing link (that will protect us from any truncate-generated 603 * removals - all blocks on the path are immune now) and possibly force the 604 * write on the parent block. 605 * That has a nice additional property: no special recovery from the failed 606 * allocations is needed - we simply release blocks and do not touch anything 607 * reachable from inode. 608 * 609 * `handle' can be NULL if create == 0. 610 * 611 * return > 0, # of blocks mapped or allocated. 612 * return = 0, if plain lookup failed. 613 * return < 0, error case. 614 */ 615 static int ext2_get_blocks(struct inode *inode, 616 sector_t iblock, unsigned long maxblocks, 617 struct buffer_head *bh_result, 618 int create) 619 { 620 int err = -EIO; 621 int offsets[4]; 622 Indirect chain[4]; 623 Indirect *partial; 624 ext2_fsblk_t goal; 625 int indirect_blks; 626 int blocks_to_boundary = 0; 627 int depth; 628 struct ext2_inode_info *ei = EXT2_I(inode); 629 int count = 0; 630 ext2_fsblk_t first_block = 0; 631 632 depth = ext2_block_to_path(inode,iblock,offsets,&blocks_to_boundary); 633 634 if (depth == 0) 635 return (err); 636 637 partial = ext2_get_branch(inode, depth, offsets, chain, &err); 638 /* Simplest case - block found, no allocation needed */ 639 if (!partial) { 640 first_block = le32_to_cpu(chain[depth - 1].key); 641 clear_buffer_new(bh_result); /* What's this do? */ 642 count++; 643 /*map more blocks*/ 644 while (count < maxblocks && count <= blocks_to_boundary) { 645 ext2_fsblk_t blk; 646 647 if (!verify_chain(chain, chain + depth - 1)) { 648 /* 649 * Indirect block might be removed by 650 * truncate while we were reading it. 651 * Handling of that case: forget what we've 652 * got now, go to reread. 653 */ 654 err = -EAGAIN; 655 count = 0; 656 break; 657 } 658 blk = le32_to_cpu(*(chain[depth-1].p + count)); 659 if (blk == first_block + count) 660 count++; 661 else 662 break; 663 } 664 if (err != -EAGAIN) 665 goto got_it; 666 } 667 668 /* Next simple case - plain lookup or failed read of indirect block */ 669 if (!create || err == -EIO) 670 goto cleanup; 671 672 mutex_lock(&ei->truncate_mutex); 673 /* 674 * If the indirect block is missing while we are reading 675 * the chain(ext2_get_branch() returns -EAGAIN err), or 676 * if the chain has been changed after we grab the semaphore, 677 * (either because another process truncated this branch, or 678 * another get_block allocated this branch) re-grab the chain to see if 679 * the request block has been allocated or not. 680 * 681 * Since we already block the truncate/other get_block 682 * at this point, we will have the current copy of the chain when we 683 * splice the branch into the tree. 684 */ 685 if (err == -EAGAIN || !verify_chain(chain, partial)) { 686 while (partial > chain) { 687 brelse(partial->bh); 688 partial--; 689 } 690 partial = ext2_get_branch(inode, depth, offsets, chain, &err); 691 if (!partial) { 692 count++; 693 mutex_unlock(&ei->truncate_mutex); 694 if (err) 695 goto cleanup; 696 clear_buffer_new(bh_result); 697 goto got_it; 698 } 699 } 700 701 /* 702 * Okay, we need to do block allocation. Lazily initialize the block 703 * allocation info here if necessary 704 */ 705 if (S_ISREG(inode->i_mode) && (!ei->i_block_alloc_info)) 706 ext2_init_block_alloc_info(inode); 707 708 goal = ext2_find_goal(inode, iblock, partial); 709 710 /* the number of blocks need to allocate for [d,t]indirect blocks */ 711 indirect_blks = (chain + depth) - partial - 1; 712 /* 713 * Next look up the indirect map to count the totoal number of 714 * direct blocks to allocate for this branch. 715 */ 716 count = ext2_blks_to_allocate(partial, indirect_blks, 717 maxblocks, blocks_to_boundary); 718 /* 719 * XXX ???? Block out ext2_truncate while we alter the tree 720 */ 721 err = ext2_alloc_branch(inode, indirect_blks, &count, goal, 722 offsets + (partial - chain), partial); 723 724 if (err) { 725 mutex_unlock(&ei->truncate_mutex); 726 goto cleanup; 727 } 728 729 if (ext2_use_xip(inode->i_sb)) { 730 /* 731 * we need to clear the block 732 */ 733 err = ext2_clear_xip_target (inode, 734 le32_to_cpu(chain[depth-1].key)); 735 if (err) { 736 mutex_unlock(&ei->truncate_mutex); 737 goto cleanup; 738 } 739 } 740 741 ext2_splice_branch(inode, iblock, partial, indirect_blks, count); 742 mutex_unlock(&ei->truncate_mutex); 743 set_buffer_new(bh_result); 744 got_it: 745 map_bh(bh_result, inode->i_sb, le32_to_cpu(chain[depth-1].key)); 746 if (count > blocks_to_boundary) 747 set_buffer_boundary(bh_result); 748 err = count; 749 /* Clean up and exit */ 750 partial = chain + depth - 1; /* the whole chain */ 751 cleanup: 752 while (partial > chain) { 753 brelse(partial->bh); 754 partial--; 755 } 756 return err; 757 } 758 759 int ext2_get_block(struct inode *inode, sector_t iblock, struct buffer_head *bh_result, int create) 760 { 761 unsigned max_blocks = bh_result->b_size >> inode->i_blkbits; 762 int ret = ext2_get_blocks(inode, iblock, max_blocks, 763 bh_result, create); 764 if (ret > 0) { 765 bh_result->b_size = (ret << inode->i_blkbits); 766 ret = 0; 767 } 768 return ret; 769 770 } 771 772 int ext2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, 773 u64 start, u64 len) 774 { 775 return generic_block_fiemap(inode, fieinfo, start, len, 776 ext2_get_block); 777 } 778 779 static int ext2_writepage(struct page *page, struct writeback_control *wbc) 780 { 781 return block_write_full_page(page, ext2_get_block, wbc); 782 } 783 784 static int ext2_readpage(struct file *file, struct page *page) 785 { 786 return mpage_readpage(page, ext2_get_block); 787 } 788 789 static int 790 ext2_readpages(struct file *file, struct address_space *mapping, 791 struct list_head *pages, unsigned nr_pages) 792 { 793 return mpage_readpages(mapping, pages, nr_pages, ext2_get_block); 794 } 795 796 static int 797 ext2_write_begin(struct file *file, struct address_space *mapping, 798 loff_t pos, unsigned len, unsigned flags, 799 struct page **pagep, void **fsdata) 800 { 801 int ret; 802 803 ret = block_write_begin(mapping, pos, len, flags, pagep, 804 ext2_get_block); 805 if (ret < 0) 806 ext2_write_failed(mapping, pos + len); 807 return ret; 808 } 809 810 static int ext2_write_end(struct file *file, struct address_space *mapping, 811 loff_t pos, unsigned len, unsigned copied, 812 struct page *page, void *fsdata) 813 { 814 int ret; 815 816 ret = generic_write_end(file, mapping, pos, len, copied, page, fsdata); 817 if (ret < len) 818 ext2_write_failed(mapping, pos + len); 819 return ret; 820 } 821 822 static int 823 ext2_nobh_write_begin(struct file *file, struct address_space *mapping, 824 loff_t pos, unsigned len, unsigned flags, 825 struct page **pagep, void **fsdata) 826 { 827 int ret; 828 829 ret = nobh_write_begin(mapping, pos, len, flags, pagep, fsdata, 830 ext2_get_block); 831 if (ret < 0) 832 ext2_write_failed(mapping, pos + len); 833 return ret; 834 } 835 836 static int ext2_nobh_writepage(struct page *page, 837 struct writeback_control *wbc) 838 { 839 return nobh_writepage(page, ext2_get_block, wbc); 840 } 841 842 static sector_t ext2_bmap(struct address_space *mapping, sector_t block) 843 { 844 return generic_block_bmap(mapping,block,ext2_get_block); 845 } 846 847 static ssize_t 848 ext2_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov, 849 loff_t offset, unsigned long nr_segs) 850 { 851 struct file *file = iocb->ki_filp; 852 struct address_space *mapping = file->f_mapping; 853 struct inode *inode = mapping->host; 854 ssize_t ret; 855 856 ret = blockdev_direct_IO(rw, iocb, inode, iov, offset, nr_segs, 857 ext2_get_block); 858 if (ret < 0 && (rw & WRITE)) 859 ext2_write_failed(mapping, offset + iov_length(iov, nr_segs)); 860 return ret; 861 } 862 863 static int 864 ext2_writepages(struct address_space *mapping, struct writeback_control *wbc) 865 { 866 return mpage_writepages(mapping, wbc, ext2_get_block); 867 } 868 869 const struct address_space_operations ext2_aops = { 870 .readpage = ext2_readpage, 871 .readpages = ext2_readpages, 872 .writepage = ext2_writepage, 873 .write_begin = ext2_write_begin, 874 .write_end = ext2_write_end, 875 .bmap = ext2_bmap, 876 .direct_IO = ext2_direct_IO, 877 .writepages = ext2_writepages, 878 .migratepage = buffer_migrate_page, 879 .is_partially_uptodate = block_is_partially_uptodate, 880 .error_remove_page = generic_error_remove_page, 881 }; 882 883 const struct address_space_operations ext2_aops_xip = { 884 .bmap = ext2_bmap, 885 .get_xip_mem = ext2_get_xip_mem, 886 }; 887 888 const struct address_space_operations ext2_nobh_aops = { 889 .readpage = ext2_readpage, 890 .readpages = ext2_readpages, 891 .writepage = ext2_nobh_writepage, 892 .write_begin = ext2_nobh_write_begin, 893 .write_end = nobh_write_end, 894 .bmap = ext2_bmap, 895 .direct_IO = ext2_direct_IO, 896 .writepages = ext2_writepages, 897 .migratepage = buffer_migrate_page, 898 .error_remove_page = generic_error_remove_page, 899 }; 900 901 /* 902 * Probably it should be a library function... search for first non-zero word 903 * or memcmp with zero_page, whatever is better for particular architecture. 904 * Linus? 905 */ 906 static inline int all_zeroes(__le32 *p, __le32 *q) 907 { 908 while (p < q) 909 if (*p++) 910 return 0; 911 return 1; 912 } 913 914 /** 915 * ext2_find_shared - find the indirect blocks for partial truncation. 916 * @inode: inode in question 917 * @depth: depth of the affected branch 918 * @offsets: offsets of pointers in that branch (see ext2_block_to_path) 919 * @chain: place to store the pointers to partial indirect blocks 920 * @top: place to the (detached) top of branch 921 * 922 * This is a helper function used by ext2_truncate(). 923 * 924 * When we do truncate() we may have to clean the ends of several indirect 925 * blocks but leave the blocks themselves alive. Block is partially 926 * truncated if some data below the new i_size is referred from it (and 927 * it is on the path to the first completely truncated data block, indeed). 928 * We have to free the top of that path along with everything to the right 929 * of the path. Since no allocation past the truncation point is possible 930 * until ext2_truncate() finishes, we may safely do the latter, but top 931 * of branch may require special attention - pageout below the truncation 932 * point might try to populate it. 933 * 934 * We atomically detach the top of branch from the tree, store the block 935 * number of its root in *@top, pointers to buffer_heads of partially 936 * truncated blocks - in @chain[].bh and pointers to their last elements 937 * that should not be removed - in @chain[].p. Return value is the pointer 938 * to last filled element of @chain. 939 * 940 * The work left to caller to do the actual freeing of subtrees: 941 * a) free the subtree starting from *@top 942 * b) free the subtrees whose roots are stored in 943 * (@chain[i].p+1 .. end of @chain[i].bh->b_data) 944 * c) free the subtrees growing from the inode past the @chain[0].p 945 * (no partially truncated stuff there). 946 */ 947 948 static Indirect *ext2_find_shared(struct inode *inode, 949 int depth, 950 int offsets[4], 951 Indirect chain[4], 952 __le32 *top) 953 { 954 Indirect *partial, *p; 955 int k, err; 956 957 *top = 0; 958 for (k = depth; k > 1 && !offsets[k-1]; k--) 959 ; 960 partial = ext2_get_branch(inode, k, offsets, chain, &err); 961 if (!partial) 962 partial = chain + k-1; 963 /* 964 * If the branch acquired continuation since we've looked at it - 965 * fine, it should all survive and (new) top doesn't belong to us. 966 */ 967 write_lock(&EXT2_I(inode)->i_meta_lock); 968 if (!partial->key && *partial->p) { 969 write_unlock(&EXT2_I(inode)->i_meta_lock); 970 goto no_top; 971 } 972 for (p=partial; p>chain && all_zeroes((__le32*)p->bh->b_data,p->p); p--) 973 ; 974 /* 975 * OK, we've found the last block that must survive. The rest of our 976 * branch should be detached before unlocking. However, if that rest 977 * of branch is all ours and does not grow immediately from the inode 978 * it's easier to cheat and just decrement partial->p. 979 */ 980 if (p == chain + k - 1 && p > chain) { 981 p->p--; 982 } else { 983 *top = *p->p; 984 *p->p = 0; 985 } 986 write_unlock(&EXT2_I(inode)->i_meta_lock); 987 988 while(partial > p) 989 { 990 brelse(partial->bh); 991 partial--; 992 } 993 no_top: 994 return partial; 995 } 996 997 /** 998 * ext2_free_data - free a list of data blocks 999 * @inode: inode we are dealing with 1000 * @p: array of block numbers 1001 * @q: points immediately past the end of array 1002 * 1003 * We are freeing all blocks referred from that array (numbers are 1004 * stored as little-endian 32-bit) and updating @inode->i_blocks 1005 * appropriately. 1006 */ 1007 static inline void ext2_free_data(struct inode *inode, __le32 *p, __le32 *q) 1008 { 1009 unsigned long block_to_free = 0, count = 0; 1010 unsigned long nr; 1011 1012 for ( ; p < q ; p++) { 1013 nr = le32_to_cpu(*p); 1014 if (nr) { 1015 *p = 0; 1016 /* accumulate blocks to free if they're contiguous */ 1017 if (count == 0) 1018 goto free_this; 1019 else if (block_to_free == nr - count) 1020 count++; 1021 else { 1022 ext2_free_blocks (inode, block_to_free, count); 1023 mark_inode_dirty(inode); 1024 free_this: 1025 block_to_free = nr; 1026 count = 1; 1027 } 1028 } 1029 } 1030 if (count > 0) { 1031 ext2_free_blocks (inode, block_to_free, count); 1032 mark_inode_dirty(inode); 1033 } 1034 } 1035 1036 /** 1037 * ext2_free_branches - free an array of branches 1038 * @inode: inode we are dealing with 1039 * @p: array of block numbers 1040 * @q: pointer immediately past the end of array 1041 * @depth: depth of the branches to free 1042 * 1043 * We are freeing all blocks referred from these branches (numbers are 1044 * stored as little-endian 32-bit) and updating @inode->i_blocks 1045 * appropriately. 1046 */ 1047 static void ext2_free_branches(struct inode *inode, __le32 *p, __le32 *q, int depth) 1048 { 1049 struct buffer_head * bh; 1050 unsigned long nr; 1051 1052 if (depth--) { 1053 int addr_per_block = EXT2_ADDR_PER_BLOCK(inode->i_sb); 1054 for ( ; p < q ; p++) { 1055 nr = le32_to_cpu(*p); 1056 if (!nr) 1057 continue; 1058 *p = 0; 1059 bh = sb_bread(inode->i_sb, nr); 1060 /* 1061 * A read failure? Report error and clear slot 1062 * (should be rare). 1063 */ 1064 if (!bh) { 1065 ext2_error(inode->i_sb, "ext2_free_branches", 1066 "Read failure, inode=%ld, block=%ld", 1067 inode->i_ino, nr); 1068 continue; 1069 } 1070 ext2_free_branches(inode, 1071 (__le32*)bh->b_data, 1072 (__le32*)bh->b_data + addr_per_block, 1073 depth); 1074 bforget(bh); 1075 ext2_free_blocks(inode, nr, 1); 1076 mark_inode_dirty(inode); 1077 } 1078 } else 1079 ext2_free_data(inode, p, q); 1080 } 1081 1082 static void __ext2_truncate_blocks(struct inode *inode, loff_t offset) 1083 { 1084 __le32 *i_data = EXT2_I(inode)->i_data; 1085 struct ext2_inode_info *ei = EXT2_I(inode); 1086 int addr_per_block = EXT2_ADDR_PER_BLOCK(inode->i_sb); 1087 int offsets[4]; 1088 Indirect chain[4]; 1089 Indirect *partial; 1090 __le32 nr = 0; 1091 int n; 1092 long iblock; 1093 unsigned blocksize; 1094 blocksize = inode->i_sb->s_blocksize; 1095 iblock = (offset + blocksize-1) >> EXT2_BLOCK_SIZE_BITS(inode->i_sb); 1096 1097 n = ext2_block_to_path(inode, iblock, offsets, NULL); 1098 if (n == 0) 1099 return; 1100 1101 /* 1102 * From here we block out all ext2_get_block() callers who want to 1103 * modify the block allocation tree. 1104 */ 1105 mutex_lock(&ei->truncate_mutex); 1106 1107 if (n == 1) { 1108 ext2_free_data(inode, i_data+offsets[0], 1109 i_data + EXT2_NDIR_BLOCKS); 1110 goto do_indirects; 1111 } 1112 1113 partial = ext2_find_shared(inode, n, offsets, chain, &nr); 1114 /* Kill the top of shared branch (already detached) */ 1115 if (nr) { 1116 if (partial == chain) 1117 mark_inode_dirty(inode); 1118 else 1119 mark_buffer_dirty_inode(partial->bh, inode); 1120 ext2_free_branches(inode, &nr, &nr+1, (chain+n-1) - partial); 1121 } 1122 /* Clear the ends of indirect blocks on the shared branch */ 1123 while (partial > chain) { 1124 ext2_free_branches(inode, 1125 partial->p + 1, 1126 (__le32*)partial->bh->b_data+addr_per_block, 1127 (chain+n-1) - partial); 1128 mark_buffer_dirty_inode(partial->bh, inode); 1129 brelse (partial->bh); 1130 partial--; 1131 } 1132 do_indirects: 1133 /* Kill the remaining (whole) subtrees */ 1134 switch (offsets[0]) { 1135 default: 1136 nr = i_data[EXT2_IND_BLOCK]; 1137 if (nr) { 1138 i_data[EXT2_IND_BLOCK] = 0; 1139 mark_inode_dirty(inode); 1140 ext2_free_branches(inode, &nr, &nr+1, 1); 1141 } 1142 case EXT2_IND_BLOCK: 1143 nr = i_data[EXT2_DIND_BLOCK]; 1144 if (nr) { 1145 i_data[EXT2_DIND_BLOCK] = 0; 1146 mark_inode_dirty(inode); 1147 ext2_free_branches(inode, &nr, &nr+1, 2); 1148 } 1149 case EXT2_DIND_BLOCK: 1150 nr = i_data[EXT2_TIND_BLOCK]; 1151 if (nr) { 1152 i_data[EXT2_TIND_BLOCK] = 0; 1153 mark_inode_dirty(inode); 1154 ext2_free_branches(inode, &nr, &nr+1, 3); 1155 } 1156 case EXT2_TIND_BLOCK: 1157 ; 1158 } 1159 1160 ext2_discard_reservation(inode); 1161 1162 mutex_unlock(&ei->truncate_mutex); 1163 } 1164 1165 static void ext2_truncate_blocks(struct inode *inode, loff_t offset) 1166 { 1167 /* 1168 * XXX: it seems like a bug here that we don't allow 1169 * IS_APPEND inode to have blocks-past-i_size trimmed off. 1170 * review and fix this. 1171 * 1172 * Also would be nice to be able to handle IO errors and such, 1173 * but that's probably too much to ask. 1174 */ 1175 if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || 1176 S_ISLNK(inode->i_mode))) 1177 return; 1178 if (ext2_inode_is_fast_symlink(inode)) 1179 return; 1180 if (IS_APPEND(inode) || IS_IMMUTABLE(inode)) 1181 return; 1182 __ext2_truncate_blocks(inode, offset); 1183 } 1184 1185 static int ext2_setsize(struct inode *inode, loff_t newsize) 1186 { 1187 int error; 1188 1189 if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || 1190 S_ISLNK(inode->i_mode))) 1191 return -EINVAL; 1192 if (ext2_inode_is_fast_symlink(inode)) 1193 return -EINVAL; 1194 if (IS_APPEND(inode) || IS_IMMUTABLE(inode)) 1195 return -EPERM; 1196 1197 inode_dio_wait(inode); 1198 1199 if (mapping_is_xip(inode->i_mapping)) 1200 error = xip_truncate_page(inode->i_mapping, newsize); 1201 else if (test_opt(inode->i_sb, NOBH)) 1202 error = nobh_truncate_page(inode->i_mapping, 1203 newsize, ext2_get_block); 1204 else 1205 error = block_truncate_page(inode->i_mapping, 1206 newsize, ext2_get_block); 1207 if (error) 1208 return error; 1209 1210 truncate_setsize(inode, newsize); 1211 __ext2_truncate_blocks(inode, newsize); 1212 1213 inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC; 1214 if (inode_needs_sync(inode)) { 1215 sync_mapping_buffers(inode->i_mapping); 1216 sync_inode_metadata(inode, 1); 1217 } else { 1218 mark_inode_dirty(inode); 1219 } 1220 1221 return 0; 1222 } 1223 1224 static struct ext2_inode *ext2_get_inode(struct super_block *sb, ino_t ino, 1225 struct buffer_head **p) 1226 { 1227 struct buffer_head * bh; 1228 unsigned long block_group; 1229 unsigned long block; 1230 unsigned long offset; 1231 struct ext2_group_desc * gdp; 1232 1233 *p = NULL; 1234 if ((ino != EXT2_ROOT_INO && ino < EXT2_FIRST_INO(sb)) || 1235 ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count)) 1236 goto Einval; 1237 1238 block_group = (ino - 1) / EXT2_INODES_PER_GROUP(sb); 1239 gdp = ext2_get_group_desc(sb, block_group, NULL); 1240 if (!gdp) 1241 goto Egdp; 1242 /* 1243 * Figure out the offset within the block group inode table 1244 */ 1245 offset = ((ino - 1) % EXT2_INODES_PER_GROUP(sb)) * EXT2_INODE_SIZE(sb); 1246 block = le32_to_cpu(gdp->bg_inode_table) + 1247 (offset >> EXT2_BLOCK_SIZE_BITS(sb)); 1248 if (!(bh = sb_bread(sb, block))) 1249 goto Eio; 1250 1251 *p = bh; 1252 offset &= (EXT2_BLOCK_SIZE(sb) - 1); 1253 return (struct ext2_inode *) (bh->b_data + offset); 1254 1255 Einval: 1256 ext2_error(sb, "ext2_get_inode", "bad inode number: %lu", 1257 (unsigned long) ino); 1258 return ERR_PTR(-EINVAL); 1259 Eio: 1260 ext2_error(sb, "ext2_get_inode", 1261 "unable to read inode block - inode=%lu, block=%lu", 1262 (unsigned long) ino, block); 1263 Egdp: 1264 return ERR_PTR(-EIO); 1265 } 1266 1267 void ext2_set_inode_flags(struct inode *inode) 1268 { 1269 unsigned int flags = EXT2_I(inode)->i_flags; 1270 1271 inode->i_flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC); 1272 if (flags & EXT2_SYNC_FL) 1273 inode->i_flags |= S_SYNC; 1274 if (flags & EXT2_APPEND_FL) 1275 inode->i_flags |= S_APPEND; 1276 if (flags & EXT2_IMMUTABLE_FL) 1277 inode->i_flags |= S_IMMUTABLE; 1278 if (flags & EXT2_NOATIME_FL) 1279 inode->i_flags |= S_NOATIME; 1280 if (flags & EXT2_DIRSYNC_FL) 1281 inode->i_flags |= S_DIRSYNC; 1282 } 1283 1284 /* Propagate flags from i_flags to EXT2_I(inode)->i_flags */ 1285 void ext2_get_inode_flags(struct ext2_inode_info *ei) 1286 { 1287 unsigned int flags = ei->vfs_inode.i_flags; 1288 1289 ei->i_flags &= ~(EXT2_SYNC_FL|EXT2_APPEND_FL| 1290 EXT2_IMMUTABLE_FL|EXT2_NOATIME_FL|EXT2_DIRSYNC_FL); 1291 if (flags & S_SYNC) 1292 ei->i_flags |= EXT2_SYNC_FL; 1293 if (flags & S_APPEND) 1294 ei->i_flags |= EXT2_APPEND_FL; 1295 if (flags & S_IMMUTABLE) 1296 ei->i_flags |= EXT2_IMMUTABLE_FL; 1297 if (flags & S_NOATIME) 1298 ei->i_flags |= EXT2_NOATIME_FL; 1299 if (flags & S_DIRSYNC) 1300 ei->i_flags |= EXT2_DIRSYNC_FL; 1301 } 1302 1303 struct inode *ext2_iget (struct super_block *sb, unsigned long ino) 1304 { 1305 struct ext2_inode_info *ei; 1306 struct buffer_head * bh; 1307 struct ext2_inode *raw_inode; 1308 struct inode *inode; 1309 long ret = -EIO; 1310 int n; 1311 uid_t i_uid; 1312 gid_t i_gid; 1313 1314 inode = iget_locked(sb, ino); 1315 if (!inode) 1316 return ERR_PTR(-ENOMEM); 1317 if (!(inode->i_state & I_NEW)) 1318 return inode; 1319 1320 ei = EXT2_I(inode); 1321 ei->i_block_alloc_info = NULL; 1322 1323 raw_inode = ext2_get_inode(inode->i_sb, ino, &bh); 1324 if (IS_ERR(raw_inode)) { 1325 ret = PTR_ERR(raw_inode); 1326 goto bad_inode; 1327 } 1328 1329 inode->i_mode = le16_to_cpu(raw_inode->i_mode); 1330 i_uid = (uid_t)le16_to_cpu(raw_inode->i_uid_low); 1331 i_gid = (gid_t)le16_to_cpu(raw_inode->i_gid_low); 1332 if (!(test_opt (inode->i_sb, NO_UID32))) { 1333 i_uid |= le16_to_cpu(raw_inode->i_uid_high) << 16; 1334 i_gid |= le16_to_cpu(raw_inode->i_gid_high) << 16; 1335 } 1336 i_uid_write(inode, i_uid); 1337 i_gid_write(inode, i_gid); 1338 set_nlink(inode, le16_to_cpu(raw_inode->i_links_count)); 1339 inode->i_size = le32_to_cpu(raw_inode->i_size); 1340 inode->i_atime.tv_sec = (signed)le32_to_cpu(raw_inode->i_atime); 1341 inode->i_ctime.tv_sec = (signed)le32_to_cpu(raw_inode->i_ctime); 1342 inode->i_mtime.tv_sec = (signed)le32_to_cpu(raw_inode->i_mtime); 1343 inode->i_atime.tv_nsec = inode->i_mtime.tv_nsec = inode->i_ctime.tv_nsec = 0; 1344 ei->i_dtime = le32_to_cpu(raw_inode->i_dtime); 1345 /* We now have enough fields to check if the inode was active or not. 1346 * This is needed because nfsd might try to access dead inodes 1347 * the test is that same one that e2fsck uses 1348 * NeilBrown 1999oct15 1349 */ 1350 if (inode->i_nlink == 0 && (inode->i_mode == 0 || ei->i_dtime)) { 1351 /* this inode is deleted */ 1352 brelse (bh); 1353 ret = -ESTALE; 1354 goto bad_inode; 1355 } 1356 inode->i_blocks = le32_to_cpu(raw_inode->i_blocks); 1357 ei->i_flags = le32_to_cpu(raw_inode->i_flags); 1358 ei->i_faddr = le32_to_cpu(raw_inode->i_faddr); 1359 ei->i_frag_no = raw_inode->i_frag; 1360 ei->i_frag_size = raw_inode->i_fsize; 1361 ei->i_file_acl = le32_to_cpu(raw_inode->i_file_acl); 1362 ei->i_dir_acl = 0; 1363 if (S_ISREG(inode->i_mode)) 1364 inode->i_size |= ((__u64)le32_to_cpu(raw_inode->i_size_high)) << 32; 1365 else 1366 ei->i_dir_acl = le32_to_cpu(raw_inode->i_dir_acl); 1367 ei->i_dtime = 0; 1368 inode->i_generation = le32_to_cpu(raw_inode->i_generation); 1369 ei->i_state = 0; 1370 ei->i_block_group = (ino - 1) / EXT2_INODES_PER_GROUP(inode->i_sb); 1371 ei->i_dir_start_lookup = 0; 1372 1373 /* 1374 * NOTE! The in-memory inode i_data array is in little-endian order 1375 * even on big-endian machines: we do NOT byteswap the block numbers! 1376 */ 1377 for (n = 0; n < EXT2_N_BLOCKS; n++) 1378 ei->i_data[n] = raw_inode->i_block[n]; 1379 1380 if (S_ISREG(inode->i_mode)) { 1381 inode->i_op = &ext2_file_inode_operations; 1382 if (ext2_use_xip(inode->i_sb)) { 1383 inode->i_mapping->a_ops = &ext2_aops_xip; 1384 inode->i_fop = &ext2_xip_file_operations; 1385 } else if (test_opt(inode->i_sb, NOBH)) { 1386 inode->i_mapping->a_ops = &ext2_nobh_aops; 1387 inode->i_fop = &ext2_file_operations; 1388 } else { 1389 inode->i_mapping->a_ops = &ext2_aops; 1390 inode->i_fop = &ext2_file_operations; 1391 } 1392 } else if (S_ISDIR(inode->i_mode)) { 1393 inode->i_op = &ext2_dir_inode_operations; 1394 inode->i_fop = &ext2_dir_operations; 1395 if (test_opt(inode->i_sb, NOBH)) 1396 inode->i_mapping->a_ops = &ext2_nobh_aops; 1397 else 1398 inode->i_mapping->a_ops = &ext2_aops; 1399 } else if (S_ISLNK(inode->i_mode)) { 1400 if (ext2_inode_is_fast_symlink(inode)) { 1401 inode->i_op = &ext2_fast_symlink_inode_operations; 1402 nd_terminate_link(ei->i_data, inode->i_size, 1403 sizeof(ei->i_data) - 1); 1404 } else { 1405 inode->i_op = &ext2_symlink_inode_operations; 1406 if (test_opt(inode->i_sb, NOBH)) 1407 inode->i_mapping->a_ops = &ext2_nobh_aops; 1408 else 1409 inode->i_mapping->a_ops = &ext2_aops; 1410 } 1411 } else { 1412 inode->i_op = &ext2_special_inode_operations; 1413 if (raw_inode->i_block[0]) 1414 init_special_inode(inode, inode->i_mode, 1415 old_decode_dev(le32_to_cpu(raw_inode->i_block[0]))); 1416 else 1417 init_special_inode(inode, inode->i_mode, 1418 new_decode_dev(le32_to_cpu(raw_inode->i_block[1]))); 1419 } 1420 brelse (bh); 1421 ext2_set_inode_flags(inode); 1422 unlock_new_inode(inode); 1423 return inode; 1424 1425 bad_inode: 1426 iget_failed(inode); 1427 return ERR_PTR(ret); 1428 } 1429 1430 static int __ext2_write_inode(struct inode *inode, int do_sync) 1431 { 1432 struct ext2_inode_info *ei = EXT2_I(inode); 1433 struct super_block *sb = inode->i_sb; 1434 ino_t ino = inode->i_ino; 1435 uid_t uid = i_uid_read(inode); 1436 gid_t gid = i_gid_read(inode); 1437 struct buffer_head * bh; 1438 struct ext2_inode * raw_inode = ext2_get_inode(sb, ino, &bh); 1439 int n; 1440 int err = 0; 1441 1442 if (IS_ERR(raw_inode)) 1443 return -EIO; 1444 1445 /* For fields not not tracking in the in-memory inode, 1446 * initialise them to zero for new inodes. */ 1447 if (ei->i_state & EXT2_STATE_NEW) 1448 memset(raw_inode, 0, EXT2_SB(sb)->s_inode_size); 1449 1450 ext2_get_inode_flags(ei); 1451 raw_inode->i_mode = cpu_to_le16(inode->i_mode); 1452 if (!(test_opt(sb, NO_UID32))) { 1453 raw_inode->i_uid_low = cpu_to_le16(low_16_bits(uid)); 1454 raw_inode->i_gid_low = cpu_to_le16(low_16_bits(gid)); 1455 /* 1456 * Fix up interoperability with old kernels. Otherwise, old inodes get 1457 * re-used with the upper 16 bits of the uid/gid intact 1458 */ 1459 if (!ei->i_dtime) { 1460 raw_inode->i_uid_high = cpu_to_le16(high_16_bits(uid)); 1461 raw_inode->i_gid_high = cpu_to_le16(high_16_bits(gid)); 1462 } else { 1463 raw_inode->i_uid_high = 0; 1464 raw_inode->i_gid_high = 0; 1465 } 1466 } else { 1467 raw_inode->i_uid_low = cpu_to_le16(fs_high2lowuid(uid)); 1468 raw_inode->i_gid_low = cpu_to_le16(fs_high2lowgid(gid)); 1469 raw_inode->i_uid_high = 0; 1470 raw_inode->i_gid_high = 0; 1471 } 1472 raw_inode->i_links_count = cpu_to_le16(inode->i_nlink); 1473 raw_inode->i_size = cpu_to_le32(inode->i_size); 1474 raw_inode->i_atime = cpu_to_le32(inode->i_atime.tv_sec); 1475 raw_inode->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec); 1476 raw_inode->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec); 1477 1478 raw_inode->i_blocks = cpu_to_le32(inode->i_blocks); 1479 raw_inode->i_dtime = cpu_to_le32(ei->i_dtime); 1480 raw_inode->i_flags = cpu_to_le32(ei->i_flags); 1481 raw_inode->i_faddr = cpu_to_le32(ei->i_faddr); 1482 raw_inode->i_frag = ei->i_frag_no; 1483 raw_inode->i_fsize = ei->i_frag_size; 1484 raw_inode->i_file_acl = cpu_to_le32(ei->i_file_acl); 1485 if (!S_ISREG(inode->i_mode)) 1486 raw_inode->i_dir_acl = cpu_to_le32(ei->i_dir_acl); 1487 else { 1488 raw_inode->i_size_high = cpu_to_le32(inode->i_size >> 32); 1489 if (inode->i_size > 0x7fffffffULL) { 1490 if (!EXT2_HAS_RO_COMPAT_FEATURE(sb, 1491 EXT2_FEATURE_RO_COMPAT_LARGE_FILE) || 1492 EXT2_SB(sb)->s_es->s_rev_level == 1493 cpu_to_le32(EXT2_GOOD_OLD_REV)) { 1494 /* If this is the first large file 1495 * created, add a flag to the superblock. 1496 */ 1497 spin_lock(&EXT2_SB(sb)->s_lock); 1498 ext2_update_dynamic_rev(sb); 1499 EXT2_SET_RO_COMPAT_FEATURE(sb, 1500 EXT2_FEATURE_RO_COMPAT_LARGE_FILE); 1501 spin_unlock(&EXT2_SB(sb)->s_lock); 1502 ext2_write_super(sb); 1503 } 1504 } 1505 } 1506 1507 raw_inode->i_generation = cpu_to_le32(inode->i_generation); 1508 if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) { 1509 if (old_valid_dev(inode->i_rdev)) { 1510 raw_inode->i_block[0] = 1511 cpu_to_le32(old_encode_dev(inode->i_rdev)); 1512 raw_inode->i_block[1] = 0; 1513 } else { 1514 raw_inode->i_block[0] = 0; 1515 raw_inode->i_block[1] = 1516 cpu_to_le32(new_encode_dev(inode->i_rdev)); 1517 raw_inode->i_block[2] = 0; 1518 } 1519 } else for (n = 0; n < EXT2_N_BLOCKS; n++) 1520 raw_inode->i_block[n] = ei->i_data[n]; 1521 mark_buffer_dirty(bh); 1522 if (do_sync) { 1523 sync_dirty_buffer(bh); 1524 if (buffer_req(bh) && !buffer_uptodate(bh)) { 1525 printk ("IO error syncing ext2 inode [%s:%08lx]\n", 1526 sb->s_id, (unsigned long) ino); 1527 err = -EIO; 1528 } 1529 } 1530 ei->i_state &= ~EXT2_STATE_NEW; 1531 brelse (bh); 1532 return err; 1533 } 1534 1535 int ext2_write_inode(struct inode *inode, struct writeback_control *wbc) 1536 { 1537 return __ext2_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL); 1538 } 1539 1540 int ext2_setattr(struct dentry *dentry, struct iattr *iattr) 1541 { 1542 struct inode *inode = dentry->d_inode; 1543 int error; 1544 1545 error = inode_change_ok(inode, iattr); 1546 if (error) 1547 return error; 1548 1549 if (is_quota_modification(inode, iattr)) 1550 dquot_initialize(inode); 1551 if ((iattr->ia_valid & ATTR_UID && !uid_eq(iattr->ia_uid, inode->i_uid)) || 1552 (iattr->ia_valid & ATTR_GID && !gid_eq(iattr->ia_gid, inode->i_gid))) { 1553 error = dquot_transfer(inode, iattr); 1554 if (error) 1555 return error; 1556 } 1557 if (iattr->ia_valid & ATTR_SIZE && iattr->ia_size != inode->i_size) { 1558 error = ext2_setsize(inode, iattr->ia_size); 1559 if (error) 1560 return error; 1561 } 1562 setattr_copy(inode, iattr); 1563 if (iattr->ia_valid & ATTR_MODE) 1564 error = ext2_acl_chmod(inode); 1565 mark_inode_dirty(inode); 1566 1567 return error; 1568 } 1569