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 <linux/uio.h> 35#include "ext2.h" 36#include "acl.h" 37#include "xattr.h" 38 39static int __ext2_write_inode(struct inode *inode, int do_sync); 40 41/* 42 * Test whether an inode is a fast symlink. 43 */ 44static inline int ext2_inode_is_fast_symlink(struct inode *inode) 45{ 46 int ea_blocks = EXT2_I(inode)->i_file_acl ? 47 (inode->i_sb->s_blocksize >> 9) : 0; 48 49 return (S_ISLNK(inode->i_mode) && 50 inode->i_blocks - ea_blocks == 0); 51} 52 53static void ext2_truncate_blocks(struct inode *inode, loff_t offset); 54 55static void ext2_write_failed(struct address_space *mapping, loff_t to) 56{ 57 struct inode *inode = mapping->host; 58 59 if (to > inode->i_size) { 60 truncate_pagecache(inode, inode->i_size); 61 ext2_truncate_blocks(inode, inode->i_size); 62 } 63} 64 65/* 66 * Called at the last iput() if i_nlink is zero. 67 */ 68void ext2_evict_inode(struct inode * inode) 69{ 70 struct ext2_block_alloc_info *rsv; 71 int want_delete = 0; 72 73 if (!inode->i_nlink && !is_bad_inode(inode)) { 74 want_delete = 1; 75 dquot_initialize(inode); 76 } else { 77 dquot_drop(inode); 78 } 79 80 truncate_inode_pages_final(&inode->i_data); 81 82 if (want_delete) { 83 sb_start_intwrite(inode->i_sb); 84 /* set dtime */ 85 EXT2_I(inode)->i_dtime = get_seconds(); 86 mark_inode_dirty(inode); 87 __ext2_write_inode(inode, inode_needs_sync(inode)); 88 /* truncate to 0 */ 89 inode->i_size = 0; 90 if (inode->i_blocks) 91 ext2_truncate_blocks(inode, 0); 92 ext2_xattr_delete_inode(inode); 93 } 94 95 invalidate_inode_buffers(inode); 96 clear_inode(inode); 97 98 ext2_discard_reservation(inode); 99 rsv = EXT2_I(inode)->i_block_alloc_info; 100 EXT2_I(inode)->i_block_alloc_info = NULL; 101 if (unlikely(rsv)) 102 kfree(rsv); 103 104 if (want_delete) { 105 ext2_free_inode(inode); 106 sb_end_intwrite(inode->i_sb); 107 } 108} 109 110typedef struct { 111 __le32 *p; 112 __le32 key; 113 struct buffer_head *bh; 114} Indirect; 115 116static inline void add_chain(Indirect *p, struct buffer_head *bh, __le32 *v) 117{ 118 p->key = *(p->p = v); 119 p->bh = bh; 120} 121 122static inline int verify_chain(Indirect *from, Indirect *to) 123{ 124 while (from <= to && from->key == *from->p) 125 from++; 126 return (from > to); 127} 128 129/** 130 * ext2_block_to_path - parse the block number into array of offsets 131 * @inode: inode in question (we are only interested in its superblock) 132 * @i_block: block number to be parsed 133 * @offsets: array to store the offsets in 134 * @boundary: set this non-zero if the referred-to block is likely to be 135 * followed (on disk) by an indirect block. 136 * To store the locations of file's data ext2 uses a data structure common 137 * for UNIX filesystems - tree of pointers anchored in the inode, with 138 * data blocks at leaves and indirect blocks in intermediate nodes. 139 * This function translates the block number into path in that tree - 140 * return value is the path length and @offsets[n] is the offset of 141 * pointer to (n+1)th node in the nth one. If @block is out of range 142 * (negative or too large) warning is printed and zero returned. 143 * 144 * Note: function doesn't find node addresses, so no IO is needed. All 145 * we need to know is the capacity of indirect blocks (taken from the 146 * inode->i_sb). 147 */ 148 149/* 150 * Portability note: the last comparison (check that we fit into triple 151 * indirect block) is spelled differently, because otherwise on an 152 * architecture with 32-bit longs and 8Kb pages we might get into trouble 153 * if our filesystem had 8Kb blocks. We might use long long, but that would 154 * kill us on x86. Oh, well, at least the sign propagation does not matter - 155 * i_block would have to be negative in the very beginning, so we would not 156 * get there at all. 157 */ 158 159static int ext2_block_to_path(struct inode *inode, 160 long i_block, int offsets[4], int *boundary) 161{ 162 int ptrs = EXT2_ADDR_PER_BLOCK(inode->i_sb); 163 int ptrs_bits = EXT2_ADDR_PER_BLOCK_BITS(inode->i_sb); 164 const long direct_blocks = EXT2_NDIR_BLOCKS, 165 indirect_blocks = ptrs, 166 double_blocks = (1 << (ptrs_bits * 2)); 167 int n = 0; 168 int final = 0; 169 170 if (i_block < 0) { 171 ext2_msg(inode->i_sb, KERN_WARNING, 172 "warning: %s: block < 0", __func__); 173 } else if (i_block < direct_blocks) { 174 offsets[n++] = i_block; 175 final = direct_blocks; 176 } else if ( (i_block -= direct_blocks) < indirect_blocks) { 177 offsets[n++] = EXT2_IND_BLOCK; 178 offsets[n++] = i_block; 179 final = ptrs; 180 } else if ((i_block -= indirect_blocks) < double_blocks) { 181 offsets[n++] = EXT2_DIND_BLOCK; 182 offsets[n++] = i_block >> ptrs_bits; 183 offsets[n++] = i_block & (ptrs - 1); 184 final = ptrs; 185 } else if (((i_block -= double_blocks) >> (ptrs_bits * 2)) < ptrs) { 186 offsets[n++] = EXT2_TIND_BLOCK; 187 offsets[n++] = i_block >> (ptrs_bits * 2); 188 offsets[n++] = (i_block >> ptrs_bits) & (ptrs - 1); 189 offsets[n++] = i_block & (ptrs - 1); 190 final = ptrs; 191 } else { 192 ext2_msg(inode->i_sb, KERN_WARNING, 193 "warning: %s: block is too big", __func__); 194 } 195 if (boundary) 196 *boundary = final - 1 - (i_block & (ptrs - 1)); 197 198 return n; 199} 200 201/** 202 * ext2_get_branch - read the chain of indirect blocks leading to data 203 * @inode: inode in question 204 * @depth: depth of the chain (1 - direct pointer, etc.) 205 * @offsets: offsets of pointers in inode/indirect blocks 206 * @chain: place to store the result 207 * @err: here we store the error value 208 * 209 * Function fills the array of triples <key, p, bh> and returns %NULL 210 * if everything went OK or the pointer to the last filled triple 211 * (incomplete one) otherwise. Upon the return chain[i].key contains 212 * the number of (i+1)-th block in the chain (as it is stored in memory, 213 * i.e. little-endian 32-bit), chain[i].p contains the address of that 214 * number (it points into struct inode for i==0 and into the bh->b_data 215 * for i>0) and chain[i].bh points to the buffer_head of i-th indirect 216 * block for i>0 and NULL for i==0. In other words, it holds the block 217 * numbers of the chain, addresses they were taken from (and where we can 218 * verify that chain did not change) and buffer_heads hosting these 219 * numbers. 220 * 221 * Function stops when it stumbles upon zero pointer (absent block) 222 * (pointer to last triple returned, *@err == 0) 223 * or when it gets an IO error reading an indirect block 224 * (ditto, *@err == -EIO) 225 * or when it notices that chain had been changed while it was reading 226 * (ditto, *@err == -EAGAIN) 227 * or when it reads all @depth-1 indirect blocks successfully and finds 228 * the whole chain, all way to the data (returns %NULL, *err == 0). 229 */ 230static Indirect *ext2_get_branch(struct inode *inode, 231 int depth, 232 int *offsets, 233 Indirect chain[4], 234 int *err) 235{ 236 struct super_block *sb = inode->i_sb; 237 Indirect *p = chain; 238 struct buffer_head *bh; 239 240 *err = 0; 241 /* i_data is not going away, no lock needed */ 242 add_chain (chain, NULL, EXT2_I(inode)->i_data + *offsets); 243 if (!p->key) 244 goto no_block; 245 while (--depth) { 246 bh = sb_bread(sb, le32_to_cpu(p->key)); 247 if (!bh) 248 goto failure; 249 read_lock(&EXT2_I(inode)->i_meta_lock); 250 if (!verify_chain(chain, p)) 251 goto changed; 252 add_chain(++p, bh, (__le32*)bh->b_data + *++offsets); 253 read_unlock(&EXT2_I(inode)->i_meta_lock); 254 if (!p->key) 255 goto no_block; 256 } 257 return NULL; 258 259changed: 260 read_unlock(&EXT2_I(inode)->i_meta_lock); 261 brelse(bh); 262 *err = -EAGAIN; 263 goto no_block; 264failure: 265 *err = -EIO; 266no_block: 267 return p; 268} 269 270/** 271 * ext2_find_near - find a place for allocation with sufficient locality 272 * @inode: owner 273 * @ind: descriptor of indirect block. 274 * 275 * This function returns the preferred place for block allocation. 276 * It is used when heuristic for sequential allocation fails. 277 * Rules are: 278 * + if there is a block to the left of our position - allocate near it. 279 * + if pointer will live in indirect block - allocate near that block. 280 * + if pointer will live in inode - allocate in the same cylinder group. 281 * 282 * In the latter case we colour the starting block by the callers PID to 283 * prevent it from clashing with concurrent allocations for a different inode 284 * in the same block group. The PID is used here so that functionally related 285 * files will be close-by on-disk. 286 * 287 * Caller must make sure that @ind is valid and will stay that way. 288 */ 289 290static ext2_fsblk_t ext2_find_near(struct inode *inode, Indirect *ind) 291{ 292 struct ext2_inode_info *ei = EXT2_I(inode); 293 __le32 *start = ind->bh ? (__le32 *) ind->bh->b_data : ei->i_data; 294 __le32 *p; 295 ext2_fsblk_t bg_start; 296 ext2_fsblk_t colour; 297 298 /* Try to find previous block */ 299 for (p = ind->p - 1; p >= start; p--) 300 if (*p) 301 return le32_to_cpu(*p); 302 303 /* No such thing, so let's try location of indirect block */ 304 if (ind->bh) 305 return ind->bh->b_blocknr; 306 307 /* 308 * It is going to be referred from inode itself? OK, just put it into 309 * the same cylinder group then. 310 */ 311 bg_start = ext2_group_first_block_no(inode->i_sb, ei->i_block_group); 312 colour = (current->pid % 16) * 313 (EXT2_BLOCKS_PER_GROUP(inode->i_sb) / 16); 314 return bg_start + colour; 315} 316 317/** 318 * ext2_find_goal - find a preferred place for allocation. 319 * @inode: owner 320 * @block: block we want 321 * @partial: pointer to the last triple within a chain 322 * 323 * Returns preferred place for a block (the goal). 324 */ 325 326static inline ext2_fsblk_t ext2_find_goal(struct inode *inode, long block, 327 Indirect *partial) 328{ 329 struct ext2_block_alloc_info *block_i; 330 331 block_i = EXT2_I(inode)->i_block_alloc_info; 332 333 /* 334 * try the heuristic for sequential allocation, 335 * failing that at least try to get decent locality. 336 */ 337 if (block_i && (block == block_i->last_alloc_logical_block + 1) 338 && (block_i->last_alloc_physical_block != 0)) { 339 return block_i->last_alloc_physical_block + 1; 340 } 341 342 return ext2_find_near(inode, partial); 343} 344 345/** 346 * ext2_blks_to_allocate: Look up the block map and count the number 347 * of direct blocks need to be allocated for the given branch. 348 * 349 * @branch: chain of indirect blocks 350 * @k: number of blocks need for indirect blocks 351 * @blks: number of data blocks to be mapped. 352 * @blocks_to_boundary: the offset in the indirect block 353 * 354 * return the total number of blocks to be allocate, including the 355 * direct and indirect blocks. 356 */ 357static int 358ext2_blks_to_allocate(Indirect * branch, int k, unsigned long blks, 359 int blocks_to_boundary) 360{ 361 unsigned long count = 0; 362 363 /* 364 * Simple case, [t,d]Indirect block(s) has not allocated yet 365 * then it's clear blocks on that path have not allocated 366 */ 367 if (k > 0) { 368 /* right now don't hanel cross boundary allocation */ 369 if (blks < blocks_to_boundary + 1) 370 count += blks; 371 else 372 count += blocks_to_boundary + 1; 373 return count; 374 } 375 376 count++; 377 while (count < blks && count <= blocks_to_boundary 378 && le32_to_cpu(*(branch[0].p + count)) == 0) { 379 count++; 380 } 381 return count; 382} 383 384/** 385 * ext2_alloc_blocks: multiple allocate blocks needed for a branch 386 * @indirect_blks: the number of blocks need to allocate for indirect 387 * blocks 388 * 389 * @new_blocks: on return it will store the new block numbers for 390 * the indirect blocks(if needed) and the first direct block, 391 * @blks: on return it will store the total number of allocated 392 * direct blocks 393 */ 394static int ext2_alloc_blocks(struct inode *inode, 395 ext2_fsblk_t goal, int indirect_blks, int blks, 396 ext2_fsblk_t new_blocks[4], int *err) 397{ 398 int target, i; 399 unsigned long count = 0; 400 int index = 0; 401 ext2_fsblk_t current_block = 0; 402 int ret = 0; 403 404 /* 405 * Here we try to allocate the requested multiple blocks at once, 406 * on a best-effort basis. 407 * To build a branch, we should allocate blocks for 408 * the indirect blocks(if not allocated yet), and at least 409 * the first direct block of this branch. That's the 410 * minimum number of blocks need to allocate(required) 411 */ 412 target = blks + indirect_blks; 413 414 while (1) { 415 count = target; 416 /* allocating blocks for indirect blocks and direct blocks */ 417 current_block = ext2_new_blocks(inode,goal,&count,err); 418 if (*err) 419 goto failed_out; 420 421 target -= count; 422 /* allocate blocks for indirect blocks */ 423 while (index < indirect_blks && count) { 424 new_blocks[index++] = current_block++; 425 count--; 426 } 427 428 if (count > 0) 429 break; 430 } 431 432 /* save the new block number for the first direct block */ 433 new_blocks[index] = current_block; 434 435 /* total number of blocks allocated for direct blocks */ 436 ret = count; 437 *err = 0; 438 return ret; 439failed_out: 440 for (i = 0; i <index; i++) 441 ext2_free_blocks(inode, new_blocks[i], 1); 442 if (index) 443 mark_inode_dirty(inode); 444 return ret; 445} 446 447/** 448 * ext2_alloc_branch - allocate and set up a chain of blocks. 449 * @inode: owner 450 * @num: depth of the chain (number of blocks to allocate) 451 * @offsets: offsets (in the blocks) to store the pointers to next. 452 * @branch: place to store the chain in. 453 * 454 * This function allocates @num blocks, zeroes out all but the last one, 455 * links them into chain and (if we are synchronous) writes them to disk. 456 * In other words, it prepares a branch that can be spliced onto the 457 * inode. It stores the information about that chain in the branch[], in 458 * the same format as ext2_get_branch() would do. We are calling it after 459 * we had read the existing part of chain and partial points to the last 460 * triple of that (one with zero ->key). Upon the exit we have the same 461 * picture as after the successful ext2_get_block(), except that in one 462 * place chain is disconnected - *branch->p is still zero (we did not 463 * set the last link), but branch->key contains the number that should 464 * be placed into *branch->p to fill that gap. 465 * 466 * If allocation fails we free all blocks we've allocated (and forget 467 * their buffer_heads) and return the error value the from failed 468 * ext2_alloc_block() (normally -ENOSPC). Otherwise we set the chain 469 * as described above and return 0. 470 */ 471 472static int ext2_alloc_branch(struct inode *inode, 473 int indirect_blks, int *blks, ext2_fsblk_t goal, 474 int *offsets, Indirect *branch) 475{ 476 int blocksize = inode->i_sb->s_blocksize; 477 int i, n = 0; 478 int err = 0; 479 struct buffer_head *bh; 480 int num; 481 ext2_fsblk_t new_blocks[4]; 482 ext2_fsblk_t current_block; 483 484 num = ext2_alloc_blocks(inode, goal, indirect_blks, 485 *blks, new_blocks, &err); 486 if (err) 487 return err; 488 489 branch[0].key = cpu_to_le32(new_blocks[0]); 490 /* 491 * metadata blocks and data blocks are allocated. 492 */ 493 for (n = 1; n <= indirect_blks; n++) { 494 /* 495 * Get buffer_head for parent block, zero it out 496 * and set the pointer to new one, then send 497 * parent to disk. 498 */ 499 bh = sb_getblk(inode->i_sb, new_blocks[n-1]); 500 if (unlikely(!bh)) { 501 err = -ENOMEM; 502 goto failed; 503 } 504 branch[n].bh = bh; 505 lock_buffer(bh); 506 memset(bh->b_data, 0, blocksize); 507 branch[n].p = (__le32 *) bh->b_data + offsets[n]; 508 branch[n].key = cpu_to_le32(new_blocks[n]); 509 *branch[n].p = branch[n].key; 510 if ( n == indirect_blks) { 511 current_block = new_blocks[n]; 512 /* 513 * End of chain, update the last new metablock of 514 * the chain to point to the new allocated 515 * data blocks numbers 516 */ 517 for (i=1; i < num; i++) 518 *(branch[n].p + i) = cpu_to_le32(++current_block); 519 } 520 set_buffer_uptodate(bh); 521 unlock_buffer(bh); 522 mark_buffer_dirty_inode(bh, inode); 523 /* We used to sync bh here if IS_SYNC(inode). 524 * But we now rely upon generic_write_sync() 525 * and b_inode_buffers. But not for directories. 526 */ 527 if (S_ISDIR(inode->i_mode) && IS_DIRSYNC(inode)) 528 sync_dirty_buffer(bh); 529 } 530 *blks = num; 531 return err; 532 533failed: 534 for (i = 1; i < n; i++) 535 bforget(branch[i].bh); 536 for (i = 0; i < indirect_blks; i++) 537 ext2_free_blocks(inode, new_blocks[i], 1); 538 ext2_free_blocks(inode, new_blocks[i], num); 539 return err; 540} 541 542/** 543 * ext2_splice_branch - splice the allocated branch onto inode. 544 * @inode: owner 545 * @block: (logical) number of block we are adding 546 * @where: location of missing link 547 * @num: number of indirect blocks we are adding 548 * @blks: number of direct blocks we are adding 549 * 550 * This function fills the missing link and does all housekeeping needed in 551 * inode (->i_blocks, etc.). In case of success we end up with the full 552 * chain to new block and return 0. 553 */ 554static void ext2_splice_branch(struct inode *inode, 555 long block, Indirect *where, int num, int blks) 556{ 557 int i; 558 struct ext2_block_alloc_info *block_i; 559 ext2_fsblk_t current_block; 560 561 block_i = EXT2_I(inode)->i_block_alloc_info; 562 563 /* XXX LOCKING probably should have i_meta_lock ?*/ 564 /* That's it */ 565 566 *where->p = where->key; 567 568 /* 569 * Update the host buffer_head or inode to point to more just allocated 570 * direct blocks blocks 571 */ 572 if (num == 0 && blks > 1) { 573 current_block = le32_to_cpu(where->key) + 1; 574 for (i = 1; i < blks; i++) 575 *(where->p + i ) = cpu_to_le32(current_block++); 576 } 577 578 /* 579 * update the most recently allocated logical & physical block 580 * in i_block_alloc_info, to assist find the proper goal block for next 581 * allocation 582 */ 583 if (block_i) { 584 block_i->last_alloc_logical_block = block + blks - 1; 585 block_i->last_alloc_physical_block = 586 le32_to_cpu(where[num].key) + blks - 1; 587 } 588 589 /* We are done with atomic stuff, now do the rest of housekeeping */ 590 591 /* had we spliced it onto indirect block? */ 592 if (where->bh) 593 mark_buffer_dirty_inode(where->bh, inode); 594 595 inode->i_ctime = CURRENT_TIME_SEC; 596 mark_inode_dirty(inode); 597} 598 599/* 600 * Allocation strategy is simple: if we have to allocate something, we will 601 * have to go the whole way to leaf. So let's do it before attaching anything 602 * to tree, set linkage between the newborn blocks, write them if sync is 603 * required, recheck the path, free and repeat if check fails, otherwise 604 * set the last missing link (that will protect us from any truncate-generated 605 * removals - all blocks on the path are immune now) and possibly force the 606 * write on the parent block. 607 * That has a nice additional property: no special recovery from the failed 608 * allocations is needed - we simply release blocks and do not touch anything 609 * reachable from inode. 610 * 611 * `handle' can be NULL if create == 0. 612 * 613 * return > 0, # of blocks mapped or allocated. 614 * return = 0, if plain lookup failed. 615 * return < 0, error case. 616 */ 617static int ext2_get_blocks(struct inode *inode, 618 sector_t iblock, unsigned long maxblocks, 619 struct buffer_head *bh_result, 620 int create) 621{ 622 int err = -EIO; 623 int offsets[4]; 624 Indirect chain[4]; 625 Indirect *partial; 626 ext2_fsblk_t goal; 627 int indirect_blks; 628 int blocks_to_boundary = 0; 629 int depth; 630 struct ext2_inode_info *ei = EXT2_I(inode); 631 int count = 0; 632 ext2_fsblk_t first_block = 0; 633 634 BUG_ON(maxblocks == 0); 635 636 depth = ext2_block_to_path(inode,iblock,offsets,&blocks_to_boundary); 637 638 if (depth == 0) 639 return (err); 640 641 partial = ext2_get_branch(inode, depth, offsets, chain, &err); 642 /* Simplest case - block found, no allocation needed */ 643 if (!partial) { 644 first_block = le32_to_cpu(chain[depth - 1].key); 645 clear_buffer_new(bh_result); /* What's this do? */ 646 count++; 647 /*map more blocks*/ 648 while (count < maxblocks && count <= blocks_to_boundary) { 649 ext2_fsblk_t blk; 650 651 if (!verify_chain(chain, chain + depth - 1)) { 652 /* 653 * Indirect block might be removed by 654 * truncate while we were reading it. 655 * Handling of that case: forget what we've 656 * got now, go to reread. 657 */ 658 err = -EAGAIN; 659 count = 0; 660 break; 661 } 662 blk = le32_to_cpu(*(chain[depth-1].p + count)); 663 if (blk == first_block + count) 664 count++; 665 else 666 break; 667 } 668 if (err != -EAGAIN) 669 goto got_it; 670 } 671 672 /* Next simple case - plain lookup or failed read of indirect block */ 673 if (!create || err == -EIO) 674 goto cleanup; 675 676 mutex_lock(&ei->truncate_mutex); 677 /* 678 * If the indirect block is missing while we are reading 679 * the chain(ext2_get_branch() returns -EAGAIN err), or 680 * if the chain has been changed after we grab the semaphore, 681 * (either because another process truncated this branch, or 682 * another get_block allocated this branch) re-grab the chain to see if 683 * the request block has been allocated or not. 684 * 685 * Since we already block the truncate/other get_block 686 * at this point, we will have the current copy of the chain when we 687 * splice the branch into the tree. 688 */ 689 if (err == -EAGAIN || !verify_chain(chain, partial)) { 690 while (partial > chain) { 691 brelse(partial->bh); 692 partial--; 693 } 694 partial = ext2_get_branch(inode, depth, offsets, chain, &err); 695 if (!partial) { 696 count++; 697 mutex_unlock(&ei->truncate_mutex); 698 if (err) 699 goto cleanup; 700 clear_buffer_new(bh_result); 701 goto got_it; 702 } 703 } 704 705 /* 706 * Okay, we need to do block allocation. Lazily initialize the block 707 * allocation info here if necessary 708 */ 709 if (S_ISREG(inode->i_mode) && (!ei->i_block_alloc_info)) 710 ext2_init_block_alloc_info(inode); 711 712 goal = ext2_find_goal(inode, iblock, partial); 713 714 /* the number of blocks need to allocate for [d,t]indirect blocks */ 715 indirect_blks = (chain + depth) - partial - 1; 716 /* 717 * Next look up the indirect map to count the totoal number of 718 * direct blocks to allocate for this branch. 719 */ 720 count = ext2_blks_to_allocate(partial, indirect_blks, 721 maxblocks, blocks_to_boundary); 722 /* 723 * XXX ???? Block out ext2_truncate while we alter the tree 724 */ 725 err = ext2_alloc_branch(inode, indirect_blks, &count, goal, 726 offsets + (partial - chain), partial); 727 728 if (err) { 729 mutex_unlock(&ei->truncate_mutex); 730 goto cleanup; 731 } 732 733 if (IS_DAX(inode)) { 734 /* 735 * block must be initialised before we put it in the tree 736 * so that it's not found by another thread before it's 737 * initialised 738 */ 739 err = dax_clear_blocks(inode, le32_to_cpu(chain[depth-1].key), 740 1 << inode->i_blkbits); 741 if (err) { 742 mutex_unlock(&ei->truncate_mutex); 743 goto cleanup; 744 } 745 } 746 747 ext2_splice_branch(inode, iblock, partial, indirect_blks, count); 748 mutex_unlock(&ei->truncate_mutex); 749 set_buffer_new(bh_result); 750got_it: 751 map_bh(bh_result, inode->i_sb, le32_to_cpu(chain[depth-1].key)); 752 if (count > blocks_to_boundary) 753 set_buffer_boundary(bh_result); 754 err = count; 755 /* Clean up and exit */ 756 partial = chain + depth - 1; /* the whole chain */ 757cleanup: 758 while (partial > chain) { 759 brelse(partial->bh); 760 partial--; 761 } 762 return err; 763} 764 765int ext2_get_block(struct inode *inode, sector_t iblock, struct buffer_head *bh_result, int create) 766{ 767 unsigned max_blocks = bh_result->b_size >> inode->i_blkbits; 768 int ret = ext2_get_blocks(inode, iblock, max_blocks, 769 bh_result, create); 770 if (ret > 0) { 771 bh_result->b_size = (ret << inode->i_blkbits); 772 ret = 0; 773 } 774 return ret; 775 776} 777 778int ext2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, 779 u64 start, u64 len) 780{ 781 return generic_block_fiemap(inode, fieinfo, start, len, 782 ext2_get_block); 783} 784 785static int ext2_writepage(struct page *page, struct writeback_control *wbc) 786{ 787 return block_write_full_page(page, ext2_get_block, wbc); 788} 789 790static int ext2_readpage(struct file *file, struct page *page) 791{ 792 return mpage_readpage(page, ext2_get_block); 793} 794 795static int 796ext2_readpages(struct file *file, struct address_space *mapping, 797 struct list_head *pages, unsigned nr_pages) 798{ 799 return mpage_readpages(mapping, pages, nr_pages, ext2_get_block); 800} 801 802static int 803ext2_write_begin(struct file *file, struct address_space *mapping, 804 loff_t pos, unsigned len, unsigned flags, 805 struct page **pagep, void **fsdata) 806{ 807 int ret; 808 809 ret = block_write_begin(mapping, pos, len, flags, pagep, 810 ext2_get_block); 811 if (ret < 0) 812 ext2_write_failed(mapping, pos + len); 813 return ret; 814} 815 816static int ext2_write_end(struct file *file, struct address_space *mapping, 817 loff_t pos, unsigned len, unsigned copied, 818 struct page *page, void *fsdata) 819{ 820 int ret; 821 822 ret = generic_write_end(file, mapping, pos, len, copied, page, fsdata); 823 if (ret < len) 824 ext2_write_failed(mapping, pos + len); 825 return ret; 826} 827 828static int 829ext2_nobh_write_begin(struct file *file, struct address_space *mapping, 830 loff_t pos, unsigned len, unsigned flags, 831 struct page **pagep, void **fsdata) 832{ 833 int ret; 834 835 ret = nobh_write_begin(mapping, pos, len, flags, pagep, fsdata, 836 ext2_get_block); 837 if (ret < 0) 838 ext2_write_failed(mapping, pos + len); 839 return ret; 840} 841 842static int ext2_nobh_writepage(struct page *page, 843 struct writeback_control *wbc) 844{ 845 return nobh_writepage(page, ext2_get_block, wbc); 846} 847 848static sector_t ext2_bmap(struct address_space *mapping, sector_t block) 849{ 850 return generic_block_bmap(mapping,block,ext2_get_block); 851} 852 853static ssize_t 854ext2_direct_IO(struct kiocb *iocb, struct iov_iter *iter, loff_t offset) 855{ 856 struct file *file = iocb->ki_filp; 857 struct address_space *mapping = file->f_mapping; 858 struct inode *inode = mapping->host; 859 size_t count = iov_iter_count(iter); 860 ssize_t ret; 861 862 if (IS_DAX(inode)) 863 ret = dax_do_io(iocb, inode, iter, offset, ext2_get_block, NULL, 864 DIO_LOCKING); 865 else 866 ret = blockdev_direct_IO(iocb, inode, iter, offset, 867 ext2_get_block); 868 if (ret < 0 && iov_iter_rw(iter) == WRITE) 869 ext2_write_failed(mapping, offset + count); 870 return ret; 871} 872 873static int 874ext2_writepages(struct address_space *mapping, struct writeback_control *wbc) 875{ 876 return mpage_writepages(mapping, wbc, ext2_get_block); 877} 878 879const struct address_space_operations ext2_aops = { 880 .readpage = ext2_readpage, 881 .readpages = ext2_readpages, 882 .writepage = ext2_writepage, 883 .write_begin = ext2_write_begin, 884 .write_end = ext2_write_end, 885 .bmap = ext2_bmap, 886 .direct_IO = ext2_direct_IO, 887 .writepages = ext2_writepages, 888 .migratepage = buffer_migrate_page, 889 .is_partially_uptodate = block_is_partially_uptodate, 890 .error_remove_page = generic_error_remove_page, 891}; 892 893const struct address_space_operations ext2_nobh_aops = { 894 .readpage = ext2_readpage, 895 .readpages = ext2_readpages, 896 .writepage = ext2_nobh_writepage, 897 .write_begin = ext2_nobh_write_begin, 898 .write_end = nobh_write_end, 899 .bmap = ext2_bmap, 900 .direct_IO = ext2_direct_IO, 901 .writepages = ext2_writepages, 902 .migratepage = buffer_migrate_page, 903 .error_remove_page = generic_error_remove_page, 904}; 905 906/* 907 * Probably it should be a library function... search for first non-zero word 908 * or memcmp with zero_page, whatever is better for particular architecture. 909 * Linus? 910 */ 911static inline int all_zeroes(__le32 *p, __le32 *q) 912{ 913 while (p < q) 914 if (*p++) 915 return 0; 916 return 1; 917} 918 919/** 920 * ext2_find_shared - find the indirect blocks for partial truncation. 921 * @inode: inode in question 922 * @depth: depth of the affected branch 923 * @offsets: offsets of pointers in that branch (see ext2_block_to_path) 924 * @chain: place to store the pointers to partial indirect blocks 925 * @top: place to the (detached) top of branch 926 * 927 * This is a helper function used by ext2_truncate(). 928 * 929 * When we do truncate() we may have to clean the ends of several indirect 930 * blocks but leave the blocks themselves alive. Block is partially 931 * truncated if some data below the new i_size is referred from it (and 932 * it is on the path to the first completely truncated data block, indeed). 933 * We have to free the top of that path along with everything to the right 934 * of the path. Since no allocation past the truncation point is possible 935 * until ext2_truncate() finishes, we may safely do the latter, but top 936 * of branch may require special attention - pageout below the truncation 937 * point might try to populate it. 938 * 939 * We atomically detach the top of branch from the tree, store the block 940 * number of its root in *@top, pointers to buffer_heads of partially 941 * truncated blocks - in @chain[].bh and pointers to their last elements 942 * that should not be removed - in @chain[].p. Return value is the pointer 943 * to last filled element of @chain. 944 * 945 * The work left to caller to do the actual freeing of subtrees: 946 * a) free the subtree starting from *@top 947 * b) free the subtrees whose roots are stored in 948 * (@chain[i].p+1 .. end of @chain[i].bh->b_data) 949 * c) free the subtrees growing from the inode past the @chain[0].p 950 * (no partially truncated stuff there). 951 */ 952 953static Indirect *ext2_find_shared(struct inode *inode, 954 int depth, 955 int offsets[4], 956 Indirect chain[4], 957 __le32 *top) 958{ 959 Indirect *partial, *p; 960 int k, err; 961 962 *top = 0; 963 for (k = depth; k > 1 && !offsets[k-1]; k--) 964 ; 965 partial = ext2_get_branch(inode, k, offsets, chain, &err); 966 if (!partial) 967 partial = chain + k-1; 968 /* 969 * If the branch acquired continuation since we've looked at it - 970 * fine, it should all survive and (new) top doesn't belong to us. 971 */ 972 write_lock(&EXT2_I(inode)->i_meta_lock); 973 if (!partial->key && *partial->p) { 974 write_unlock(&EXT2_I(inode)->i_meta_lock); 975 goto no_top; 976 } 977 for (p=partial; p>chain && all_zeroes((__le32*)p->bh->b_data,p->p); p--) 978 ; 979 /* 980 * OK, we've found the last block that must survive. The rest of our 981 * branch should be detached before unlocking. However, if that rest 982 * of branch is all ours and does not grow immediately from the inode 983 * it's easier to cheat and just decrement partial->p. 984 */ 985 if (p == chain + k - 1 && p > chain) { 986 p->p--; 987 } else { 988 *top = *p->p; 989 *p->p = 0; 990 } 991 write_unlock(&EXT2_I(inode)->i_meta_lock); 992 993 while(partial > p) 994 { 995 brelse(partial->bh); 996 partial--; 997 } 998no_top: 999 return partial; 1000} 1001 1002/** 1003 * ext2_free_data - free a list of data blocks 1004 * @inode: inode we are dealing with 1005 * @p: array of block numbers 1006 * @q: points immediately past the end of array 1007 * 1008 * We are freeing all blocks referred from that array (numbers are 1009 * stored as little-endian 32-bit) and updating @inode->i_blocks 1010 * appropriately. 1011 */ 1012static inline void ext2_free_data(struct inode *inode, __le32 *p, __le32 *q) 1013{ 1014 unsigned long block_to_free = 0, count = 0; 1015 unsigned long nr; 1016 1017 for ( ; p < q ; p++) { 1018 nr = le32_to_cpu(*p); 1019 if (nr) { 1020 *p = 0; 1021 /* accumulate blocks to free if they're contiguous */ 1022 if (count == 0) 1023 goto free_this; 1024 else if (block_to_free == nr - count) 1025 count++; 1026 else { 1027 ext2_free_blocks (inode, block_to_free, count); 1028 mark_inode_dirty(inode); 1029 free_this: 1030 block_to_free = nr; 1031 count = 1; 1032 } 1033 } 1034 } 1035 if (count > 0) { 1036 ext2_free_blocks (inode, block_to_free, count); 1037 mark_inode_dirty(inode); 1038 } 1039} 1040 1041/** 1042 * ext2_free_branches - free an array of branches 1043 * @inode: inode we are dealing with 1044 * @p: array of block numbers 1045 * @q: pointer immediately past the end of array 1046 * @depth: depth of the branches to free 1047 * 1048 * We are freeing all blocks referred from these branches (numbers are 1049 * stored as little-endian 32-bit) and updating @inode->i_blocks 1050 * appropriately. 1051 */ 1052static void ext2_free_branches(struct inode *inode, __le32 *p, __le32 *q, int depth) 1053{ 1054 struct buffer_head * bh; 1055 unsigned long nr; 1056 1057 if (depth--) { 1058 int addr_per_block = EXT2_ADDR_PER_BLOCK(inode->i_sb); 1059 for ( ; p < q ; p++) { 1060 nr = le32_to_cpu(*p); 1061 if (!nr) 1062 continue; 1063 *p = 0; 1064 bh = sb_bread(inode->i_sb, nr); 1065 /* 1066 * A read failure? Report error and clear slot 1067 * (should be rare). 1068 */ 1069 if (!bh) { 1070 ext2_error(inode->i_sb, "ext2_free_branches", 1071 "Read failure, inode=%ld, block=%ld", 1072 inode->i_ino, nr); 1073 continue; 1074 } 1075 ext2_free_branches(inode, 1076 (__le32*)bh->b_data, 1077 (__le32*)bh->b_data + addr_per_block, 1078 depth); 1079 bforget(bh); 1080 ext2_free_blocks(inode, nr, 1); 1081 mark_inode_dirty(inode); 1082 } 1083 } else 1084 ext2_free_data(inode, p, q); 1085} 1086 1087static void __ext2_truncate_blocks(struct inode *inode, loff_t offset) 1088{ 1089 __le32 *i_data = EXT2_I(inode)->i_data; 1090 struct ext2_inode_info *ei = EXT2_I(inode); 1091 int addr_per_block = EXT2_ADDR_PER_BLOCK(inode->i_sb); 1092 int offsets[4]; 1093 Indirect chain[4]; 1094 Indirect *partial; 1095 __le32 nr = 0; 1096 int n; 1097 long iblock; 1098 unsigned blocksize; 1099 blocksize = inode->i_sb->s_blocksize; 1100 iblock = (offset + blocksize-1) >> EXT2_BLOCK_SIZE_BITS(inode->i_sb); 1101 1102 n = ext2_block_to_path(inode, iblock, offsets, NULL); 1103 if (n == 0) 1104 return; 1105 1106 /* 1107 * From here we block out all ext2_get_block() callers who want to 1108 * modify the block allocation tree. 1109 */ 1110 mutex_lock(&ei->truncate_mutex); 1111 1112 if (n == 1) { 1113 ext2_free_data(inode, i_data+offsets[0], 1114 i_data + EXT2_NDIR_BLOCKS); 1115 goto do_indirects; 1116 } 1117 1118 partial = ext2_find_shared(inode, n, offsets, chain, &nr); 1119 /* Kill the top of shared branch (already detached) */ 1120 if (nr) { 1121 if (partial == chain) 1122 mark_inode_dirty(inode); 1123 else 1124 mark_buffer_dirty_inode(partial->bh, inode); 1125 ext2_free_branches(inode, &nr, &nr+1, (chain+n-1) - partial); 1126 } 1127 /* Clear the ends of indirect blocks on the shared branch */ 1128 while (partial > chain) { 1129 ext2_free_branches(inode, 1130 partial->p + 1, 1131 (__le32*)partial->bh->b_data+addr_per_block, 1132 (chain+n-1) - partial); 1133 mark_buffer_dirty_inode(partial->bh, inode); 1134 brelse (partial->bh); 1135 partial--; 1136 } 1137do_indirects: 1138 /* Kill the remaining (whole) subtrees */ 1139 switch (offsets[0]) { 1140 default: 1141 nr = i_data[EXT2_IND_BLOCK]; 1142 if (nr) { 1143 i_data[EXT2_IND_BLOCK] = 0; 1144 mark_inode_dirty(inode); 1145 ext2_free_branches(inode, &nr, &nr+1, 1); 1146 } 1147 case EXT2_IND_BLOCK: 1148 nr = i_data[EXT2_DIND_BLOCK]; 1149 if (nr) { 1150 i_data[EXT2_DIND_BLOCK] = 0; 1151 mark_inode_dirty(inode); 1152 ext2_free_branches(inode, &nr, &nr+1, 2); 1153 } 1154 case EXT2_DIND_BLOCK: 1155 nr = i_data[EXT2_TIND_BLOCK]; 1156 if (nr) { 1157 i_data[EXT2_TIND_BLOCK] = 0; 1158 mark_inode_dirty(inode); 1159 ext2_free_branches(inode, &nr, &nr+1, 3); 1160 } 1161 case EXT2_TIND_BLOCK: 1162 ; 1163 } 1164 1165 ext2_discard_reservation(inode); 1166 1167 mutex_unlock(&ei->truncate_mutex); 1168} 1169 1170static void ext2_truncate_blocks(struct inode *inode, loff_t offset) 1171{ 1172 /* 1173 * XXX: it seems like a bug here that we don't allow 1174 * IS_APPEND inode to have blocks-past-i_size trimmed off. 1175 * review and fix this. 1176 * 1177 * Also would be nice to be able to handle IO errors and such, 1178 * but that's probably too much to ask. 1179 */ 1180 if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || 1181 S_ISLNK(inode->i_mode))) 1182 return; 1183 if (ext2_inode_is_fast_symlink(inode)) 1184 return; 1185 if (IS_APPEND(inode) || IS_IMMUTABLE(inode)) 1186 return; 1187 __ext2_truncate_blocks(inode, offset); 1188} 1189 1190static int ext2_setsize(struct inode *inode, loff_t newsize) 1191{ 1192 int error; 1193 1194 if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || 1195 S_ISLNK(inode->i_mode))) 1196 return -EINVAL; 1197 if (ext2_inode_is_fast_symlink(inode)) 1198 return -EINVAL; 1199 if (IS_APPEND(inode) || IS_IMMUTABLE(inode)) 1200 return -EPERM; 1201 1202 inode_dio_wait(inode); 1203 1204 if (IS_DAX(inode)) 1205 error = dax_truncate_page(inode, newsize, ext2_get_block); 1206 else if (test_opt(inode->i_sb, NOBH)) 1207 error = nobh_truncate_page(inode->i_mapping, 1208 newsize, ext2_get_block); 1209 else 1210 error = block_truncate_page(inode->i_mapping, 1211 newsize, ext2_get_block); 1212 if (error) 1213 return error; 1214 1215 truncate_setsize(inode, newsize); 1216 __ext2_truncate_blocks(inode, newsize); 1217 1218 inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC; 1219 if (inode_needs_sync(inode)) { 1220 sync_mapping_buffers(inode->i_mapping); 1221 sync_inode_metadata(inode, 1); 1222 } else { 1223 mark_inode_dirty(inode); 1224 } 1225 1226 return 0; 1227} 1228 1229static struct ext2_inode *ext2_get_inode(struct super_block *sb, ino_t ino, 1230 struct buffer_head **p) 1231{ 1232 struct buffer_head * bh; 1233 unsigned long block_group; 1234 unsigned long block; 1235 unsigned long offset; 1236 struct ext2_group_desc * gdp; 1237 1238 *p = NULL; 1239 if ((ino != EXT2_ROOT_INO && ino < EXT2_FIRST_INO(sb)) || 1240 ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count)) 1241 goto Einval; 1242 1243 block_group = (ino - 1) / EXT2_INODES_PER_GROUP(sb); 1244 gdp = ext2_get_group_desc(sb, block_group, NULL); 1245 if (!gdp) 1246 goto Egdp; 1247 /* 1248 * Figure out the offset within the block group inode table 1249 */ 1250 offset = ((ino - 1) % EXT2_INODES_PER_GROUP(sb)) * EXT2_INODE_SIZE(sb); 1251 block = le32_to_cpu(gdp->bg_inode_table) + 1252 (offset >> EXT2_BLOCK_SIZE_BITS(sb)); 1253 if (!(bh = sb_bread(sb, block))) 1254 goto Eio; 1255 1256 *p = bh; 1257 offset &= (EXT2_BLOCK_SIZE(sb) - 1); 1258 return (struct ext2_inode *) (bh->b_data + offset); 1259 1260Einval: 1261 ext2_error(sb, "ext2_get_inode", "bad inode number: %lu", 1262 (unsigned long) ino); 1263 return ERR_PTR(-EINVAL); 1264Eio: 1265 ext2_error(sb, "ext2_get_inode", 1266 "unable to read inode block - inode=%lu, block=%lu", 1267 (unsigned long) ino, block); 1268Egdp: 1269 return ERR_PTR(-EIO); 1270} 1271 1272void ext2_set_inode_flags(struct inode *inode) 1273{ 1274 unsigned int flags = EXT2_I(inode)->i_flags; 1275 1276 inode->i_flags &= ~(S_SYNC | S_APPEND | S_IMMUTABLE | S_NOATIME | 1277 S_DIRSYNC | S_DAX); 1278 if (flags & EXT2_SYNC_FL) 1279 inode->i_flags |= S_SYNC; 1280 if (flags & EXT2_APPEND_FL) 1281 inode->i_flags |= S_APPEND; 1282 if (flags & EXT2_IMMUTABLE_FL) 1283 inode->i_flags |= S_IMMUTABLE; 1284 if (flags & EXT2_NOATIME_FL) 1285 inode->i_flags |= S_NOATIME; 1286 if (flags & EXT2_DIRSYNC_FL) 1287 inode->i_flags |= S_DIRSYNC; 1288 if (test_opt(inode->i_sb, DAX)) 1289 inode->i_flags |= S_DAX; 1290} 1291 1292/* Propagate flags from i_flags to EXT2_I(inode)->i_flags */ 1293void ext2_get_inode_flags(struct ext2_inode_info *ei) 1294{ 1295 unsigned int flags = ei->vfs_inode.i_flags; 1296 1297 ei->i_flags &= ~(EXT2_SYNC_FL|EXT2_APPEND_FL| 1298 EXT2_IMMUTABLE_FL|EXT2_NOATIME_FL|EXT2_DIRSYNC_FL); 1299 if (flags & S_SYNC) 1300 ei->i_flags |= EXT2_SYNC_FL; 1301 if (flags & S_APPEND) 1302 ei->i_flags |= EXT2_APPEND_FL; 1303 if (flags & S_IMMUTABLE) 1304 ei->i_flags |= EXT2_IMMUTABLE_FL; 1305 if (flags & S_NOATIME) 1306 ei->i_flags |= EXT2_NOATIME_FL; 1307 if (flags & S_DIRSYNC) 1308 ei->i_flags |= EXT2_DIRSYNC_FL; 1309} 1310 1311struct inode *ext2_iget (struct super_block *sb, unsigned long ino) 1312{ 1313 struct ext2_inode_info *ei; 1314 struct buffer_head * bh; 1315 struct ext2_inode *raw_inode; 1316 struct inode *inode; 1317 long ret = -EIO; 1318 int n; 1319 uid_t i_uid; 1320 gid_t i_gid; 1321 1322 inode = iget_locked(sb, ino); 1323 if (!inode) 1324 return ERR_PTR(-ENOMEM); 1325 if (!(inode->i_state & I_NEW)) 1326 return inode; 1327 1328 ei = EXT2_I(inode); 1329 ei->i_block_alloc_info = NULL; 1330 1331 raw_inode = ext2_get_inode(inode->i_sb, ino, &bh); 1332 if (IS_ERR(raw_inode)) { 1333 ret = PTR_ERR(raw_inode); 1334 goto bad_inode; 1335 } 1336 1337 inode->i_mode = le16_to_cpu(raw_inode->i_mode); 1338 i_uid = (uid_t)le16_to_cpu(raw_inode->i_uid_low); 1339 i_gid = (gid_t)le16_to_cpu(raw_inode->i_gid_low); 1340 if (!(test_opt (inode->i_sb, NO_UID32))) { 1341 i_uid |= le16_to_cpu(raw_inode->i_uid_high) << 16; 1342 i_gid |= le16_to_cpu(raw_inode->i_gid_high) << 16; 1343 } 1344 i_uid_write(inode, i_uid); 1345 i_gid_write(inode, i_gid); 1346 set_nlink(inode, le16_to_cpu(raw_inode->i_links_count)); 1347 inode->i_size = le32_to_cpu(raw_inode->i_size); 1348 inode->i_atime.tv_sec = (signed)le32_to_cpu(raw_inode->i_atime); 1349 inode->i_ctime.tv_sec = (signed)le32_to_cpu(raw_inode->i_ctime); 1350 inode->i_mtime.tv_sec = (signed)le32_to_cpu(raw_inode->i_mtime); 1351 inode->i_atime.tv_nsec = inode->i_mtime.tv_nsec = inode->i_ctime.tv_nsec = 0; 1352 ei->i_dtime = le32_to_cpu(raw_inode->i_dtime); 1353 /* We now have enough fields to check if the inode was active or not. 1354 * This is needed because nfsd might try to access dead inodes 1355 * the test is that same one that e2fsck uses 1356 * NeilBrown 1999oct15 1357 */ 1358 if (inode->i_nlink == 0 && (inode->i_mode == 0 || ei->i_dtime)) { 1359 /* this inode is deleted */ 1360 brelse (bh); 1361 ret = -ESTALE; 1362 goto bad_inode; 1363 } 1364 inode->i_blocks = le32_to_cpu(raw_inode->i_blocks); 1365 ei->i_flags = le32_to_cpu(raw_inode->i_flags); 1366 ei->i_faddr = le32_to_cpu(raw_inode->i_faddr); 1367 ei->i_frag_no = raw_inode->i_frag; 1368 ei->i_frag_size = raw_inode->i_fsize; 1369 ei->i_file_acl = le32_to_cpu(raw_inode->i_file_acl); 1370 ei->i_dir_acl = 0; 1371 if (S_ISREG(inode->i_mode)) 1372 inode->i_size |= ((__u64)le32_to_cpu(raw_inode->i_size_high)) << 32; 1373 else 1374 ei->i_dir_acl = le32_to_cpu(raw_inode->i_dir_acl); 1375 ei->i_dtime = 0; 1376 inode->i_generation = le32_to_cpu(raw_inode->i_generation); 1377 ei->i_state = 0; 1378 ei->i_block_group = (ino - 1) / EXT2_INODES_PER_GROUP(inode->i_sb); 1379 ei->i_dir_start_lookup = 0; 1380 1381 /* 1382 * NOTE! The in-memory inode i_data array is in little-endian order 1383 * even on big-endian machines: we do NOT byteswap the block numbers! 1384 */ 1385 for (n = 0; n < EXT2_N_BLOCKS; n++) 1386 ei->i_data[n] = raw_inode->i_block[n]; 1387 1388 if (S_ISREG(inode->i_mode)) { 1389 inode->i_op = &ext2_file_inode_operations; 1390 if (test_opt(inode->i_sb, NOBH)) { 1391 inode->i_mapping->a_ops = &ext2_nobh_aops; 1392 inode->i_fop = &ext2_file_operations; 1393 } else { 1394 inode->i_mapping->a_ops = &ext2_aops; 1395 inode->i_fop = &ext2_file_operations; 1396 } 1397 } else if (S_ISDIR(inode->i_mode)) { 1398 inode->i_op = &ext2_dir_inode_operations; 1399 inode->i_fop = &ext2_dir_operations; 1400 if (test_opt(inode->i_sb, NOBH)) 1401 inode->i_mapping->a_ops = &ext2_nobh_aops; 1402 else 1403 inode->i_mapping->a_ops = &ext2_aops; 1404 } else if (S_ISLNK(inode->i_mode)) { 1405 if (ext2_inode_is_fast_symlink(inode)) { 1406 inode->i_op = &ext2_fast_symlink_inode_operations; 1407 nd_terminate_link(ei->i_data, inode->i_size, 1408 sizeof(ei->i_data) - 1); 1409 } else { 1410 inode->i_op = &ext2_symlink_inode_operations; 1411 if (test_opt(inode->i_sb, NOBH)) 1412 inode->i_mapping->a_ops = &ext2_nobh_aops; 1413 else 1414 inode->i_mapping->a_ops = &ext2_aops; 1415 } 1416 } else { 1417 inode->i_op = &ext2_special_inode_operations; 1418 if (raw_inode->i_block[0]) 1419 init_special_inode(inode, inode->i_mode, 1420 old_decode_dev(le32_to_cpu(raw_inode->i_block[0]))); 1421 else 1422 init_special_inode(inode, inode->i_mode, 1423 new_decode_dev(le32_to_cpu(raw_inode->i_block[1]))); 1424 } 1425 brelse (bh); 1426 ext2_set_inode_flags(inode); 1427 unlock_new_inode(inode); 1428 return inode; 1429 1430bad_inode: 1431 iget_failed(inode); 1432 return ERR_PTR(ret); 1433} 1434 1435static int __ext2_write_inode(struct inode *inode, int do_sync) 1436{ 1437 struct ext2_inode_info *ei = EXT2_I(inode); 1438 struct super_block *sb = inode->i_sb; 1439 ino_t ino = inode->i_ino; 1440 uid_t uid = i_uid_read(inode); 1441 gid_t gid = i_gid_read(inode); 1442 struct buffer_head * bh; 1443 struct ext2_inode * raw_inode = ext2_get_inode(sb, ino, &bh); 1444 int n; 1445 int err = 0; 1446 1447 if (IS_ERR(raw_inode)) 1448 return -EIO; 1449 1450 /* For fields not not tracking in the in-memory inode, 1451 * initialise them to zero for new inodes. */ 1452 if (ei->i_state & EXT2_STATE_NEW) 1453 memset(raw_inode, 0, EXT2_SB(sb)->s_inode_size); 1454 1455 ext2_get_inode_flags(ei); 1456 raw_inode->i_mode = cpu_to_le16(inode->i_mode); 1457 if (!(test_opt(sb, NO_UID32))) { 1458 raw_inode->i_uid_low = cpu_to_le16(low_16_bits(uid)); 1459 raw_inode->i_gid_low = cpu_to_le16(low_16_bits(gid)); 1460/* 1461 * Fix up interoperability with old kernels. Otherwise, old inodes get 1462 * re-used with the upper 16 bits of the uid/gid intact 1463 */ 1464 if (!ei->i_dtime) { 1465 raw_inode->i_uid_high = cpu_to_le16(high_16_bits(uid)); 1466 raw_inode->i_gid_high = cpu_to_le16(high_16_bits(gid)); 1467 } else { 1468 raw_inode->i_uid_high = 0; 1469 raw_inode->i_gid_high = 0; 1470 } 1471 } else { 1472 raw_inode->i_uid_low = cpu_to_le16(fs_high2lowuid(uid)); 1473 raw_inode->i_gid_low = cpu_to_le16(fs_high2lowgid(gid)); 1474 raw_inode->i_uid_high = 0; 1475 raw_inode->i_gid_high = 0; 1476 } 1477 raw_inode->i_links_count = cpu_to_le16(inode->i_nlink); 1478 raw_inode->i_size = cpu_to_le32(inode->i_size); 1479 raw_inode->i_atime = cpu_to_le32(inode->i_atime.tv_sec); 1480 raw_inode->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec); 1481 raw_inode->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec); 1482 1483 raw_inode->i_blocks = cpu_to_le32(inode->i_blocks); 1484 raw_inode->i_dtime = cpu_to_le32(ei->i_dtime); 1485 raw_inode->i_flags = cpu_to_le32(ei->i_flags); 1486 raw_inode->i_faddr = cpu_to_le32(ei->i_faddr); 1487 raw_inode->i_frag = ei->i_frag_no; 1488 raw_inode->i_fsize = ei->i_frag_size; 1489 raw_inode->i_file_acl = cpu_to_le32(ei->i_file_acl); 1490 if (!S_ISREG(inode->i_mode)) 1491 raw_inode->i_dir_acl = cpu_to_le32(ei->i_dir_acl); 1492 else { 1493 raw_inode->i_size_high = cpu_to_le32(inode->i_size >> 32); 1494 if (inode->i_size > 0x7fffffffULL) { 1495 if (!EXT2_HAS_RO_COMPAT_FEATURE(sb, 1496 EXT2_FEATURE_RO_COMPAT_LARGE_FILE) || 1497 EXT2_SB(sb)->s_es->s_rev_level == 1498 cpu_to_le32(EXT2_GOOD_OLD_REV)) { 1499 /* If this is the first large file 1500 * created, add a flag to the superblock. 1501 */ 1502 spin_lock(&EXT2_SB(sb)->s_lock); 1503 ext2_update_dynamic_rev(sb); 1504 EXT2_SET_RO_COMPAT_FEATURE(sb, 1505 EXT2_FEATURE_RO_COMPAT_LARGE_FILE); 1506 spin_unlock(&EXT2_SB(sb)->s_lock); 1507 ext2_write_super(sb); 1508 } 1509 } 1510 } 1511 1512 raw_inode->i_generation = cpu_to_le32(inode->i_generation); 1513 if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) { 1514 if (old_valid_dev(inode->i_rdev)) { 1515 raw_inode->i_block[0] = 1516 cpu_to_le32(old_encode_dev(inode->i_rdev)); 1517 raw_inode->i_block[1] = 0; 1518 } else { 1519 raw_inode->i_block[0] = 0; 1520 raw_inode->i_block[1] = 1521 cpu_to_le32(new_encode_dev(inode->i_rdev)); 1522 raw_inode->i_block[2] = 0; 1523 } 1524 } else for (n = 0; n < EXT2_N_BLOCKS; n++) 1525 raw_inode->i_block[n] = ei->i_data[n]; 1526 mark_buffer_dirty(bh); 1527 if (do_sync) { 1528 sync_dirty_buffer(bh); 1529 if (buffer_req(bh) && !buffer_uptodate(bh)) { 1530 printk ("IO error syncing ext2 inode [%s:%08lx]\n", 1531 sb->s_id, (unsigned long) ino); 1532 err = -EIO; 1533 } 1534 } 1535 ei->i_state &= ~EXT2_STATE_NEW; 1536 brelse (bh); 1537 return err; 1538} 1539 1540int ext2_write_inode(struct inode *inode, struct writeback_control *wbc) 1541{ 1542 return __ext2_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL); 1543} 1544 1545int ext2_setattr(struct dentry *dentry, struct iattr *iattr) 1546{ 1547 struct inode *inode = d_inode(dentry); 1548 int error; 1549 1550 error = inode_change_ok(inode, iattr); 1551 if (error) 1552 return error; 1553 1554 if (is_quota_modification(inode, iattr)) 1555 dquot_initialize(inode); 1556 if ((iattr->ia_valid & ATTR_UID && !uid_eq(iattr->ia_uid, inode->i_uid)) || 1557 (iattr->ia_valid & ATTR_GID && !gid_eq(iattr->ia_gid, inode->i_gid))) { 1558 error = dquot_transfer(inode, iattr); 1559 if (error) 1560 return error; 1561 } 1562 if (iattr->ia_valid & ATTR_SIZE && iattr->ia_size != inode->i_size) { 1563 error = ext2_setsize(inode, iattr->ia_size); 1564 if (error) 1565 return error; 1566 } 1567 setattr_copy(inode, iattr); 1568 if (iattr->ia_valid & ATTR_MODE) 1569 error = posix_acl_chmod(inode, inode->i_mode); 1570 mark_inode_dirty(inode); 1571 1572 return error; 1573} 1574