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/aio.h> 35 #include "ext2.h" 36 #include "acl.h" 37 #include "xip.h" 38 #include "xattr.h" 39 40 static int __ext2_write_inode(struct inode *inode, int do_sync); 41 42 /* 43 * Test whether an inode is a fast symlink. 44 */ 45 static inline int ext2_inode_is_fast_symlink(struct inode *inode) 46 { 47 int ea_blocks = EXT2_I(inode)->i_file_acl ? 48 (inode->i_sb->s_blocksize >> 9) : 0; 49 50 return (S_ISLNK(inode->i_mode) && 51 inode->i_blocks - ea_blocks == 0); 52 } 53 54 static void ext2_truncate_blocks(struct inode *inode, loff_t offset); 55 56 static void ext2_write_failed(struct address_space *mapping, loff_t to) 57 { 58 struct inode *inode = mapping->host; 59 60 if (to > inode->i_size) { 61 truncate_pagecache(inode, inode->i_size); 62 ext2_truncate_blocks(inode, inode->i_size); 63 } 64 } 65 66 /* 67 * Called at the last iput() if i_nlink is zero. 68 */ 69 void ext2_evict_inode(struct inode * inode) 70 { 71 struct ext2_block_alloc_info *rsv; 72 int want_delete = 0; 73 74 if (!inode->i_nlink && !is_bad_inode(inode)) { 75 want_delete = 1; 76 dquot_initialize(inode); 77 } else { 78 dquot_drop(inode); 79 } 80 81 truncate_inode_pages(&inode->i_data, 0); 82 83 if (want_delete) { 84 sb_start_intwrite(inode->i_sb); 85 /* set dtime */ 86 EXT2_I(inode)->i_dtime = get_seconds(); 87 mark_inode_dirty(inode); 88 __ext2_write_inode(inode, inode_needs_sync(inode)); 89 /* truncate to 0 */ 90 inode->i_size = 0; 91 if (inode->i_blocks) 92 ext2_truncate_blocks(inode, 0); 93 ext2_xattr_delete_inode(inode); 94 } 95 96 invalidate_inode_buffers(inode); 97 clear_inode(inode); 98 99 ext2_discard_reservation(inode); 100 rsv = EXT2_I(inode)->i_block_alloc_info; 101 EXT2_I(inode)->i_block_alloc_info = NULL; 102 if (unlikely(rsv)) 103 kfree(rsv); 104 105 if (want_delete) { 106 ext2_free_inode(inode); 107 sb_end_intwrite(inode->i_sb); 108 } 109 } 110 111 typedef struct { 112 __le32 *p; 113 __le32 key; 114 struct buffer_head *bh; 115 } Indirect; 116 117 static inline void add_chain(Indirect *p, struct buffer_head *bh, __le32 *v) 118 { 119 p->key = *(p->p = v); 120 p->bh = bh; 121 } 122 123 static inline int verify_chain(Indirect *from, Indirect *to) 124 { 125 while (from <= to && from->key == *from->p) 126 from++; 127 return (from > to); 128 } 129 130 /** 131 * ext2_block_to_path - parse the block number into array of offsets 132 * @inode: inode in question (we are only interested in its superblock) 133 * @i_block: block number to be parsed 134 * @offsets: array to store the offsets in 135 * @boundary: set this non-zero if the referred-to block is likely to be 136 * followed (on disk) by an indirect block. 137 * To store the locations of file's data ext2 uses a data structure common 138 * for UNIX filesystems - tree of pointers anchored in the inode, with 139 * data blocks at leaves and indirect blocks in intermediate nodes. 140 * This function translates the block number into path in that tree - 141 * return value is the path length and @offsets[n] is the offset of 142 * pointer to (n+1)th node in the nth one. If @block is out of range 143 * (negative or too large) warning is printed and zero returned. 144 * 145 * Note: function doesn't find node addresses, so no IO is needed. All 146 * we need to know is the capacity of indirect blocks (taken from the 147 * inode->i_sb). 148 */ 149 150 /* 151 * Portability note: the last comparison (check that we fit into triple 152 * indirect block) is spelled differently, because otherwise on an 153 * architecture with 32-bit longs and 8Kb pages we might get into trouble 154 * if our filesystem had 8Kb blocks. We might use long long, but that would 155 * kill us on x86. Oh, well, at least the sign propagation does not matter - 156 * i_block would have to be negative in the very beginning, so we would not 157 * get there at all. 158 */ 159 160 static int ext2_block_to_path(struct inode *inode, 161 long i_block, int offsets[4], int *boundary) 162 { 163 int ptrs = EXT2_ADDR_PER_BLOCK(inode->i_sb); 164 int ptrs_bits = EXT2_ADDR_PER_BLOCK_BITS(inode->i_sb); 165 const long direct_blocks = EXT2_NDIR_BLOCKS, 166 indirect_blocks = ptrs, 167 double_blocks = (1 << (ptrs_bits * 2)); 168 int n = 0; 169 int final = 0; 170 171 if (i_block < 0) { 172 ext2_msg(inode->i_sb, KERN_WARNING, 173 "warning: %s: block < 0", __func__); 174 } else if (i_block < direct_blocks) { 175 offsets[n++] = i_block; 176 final = direct_blocks; 177 } else if ( (i_block -= direct_blocks) < indirect_blocks) { 178 offsets[n++] = EXT2_IND_BLOCK; 179 offsets[n++] = i_block; 180 final = ptrs; 181 } else if ((i_block -= indirect_blocks) < double_blocks) { 182 offsets[n++] = EXT2_DIND_BLOCK; 183 offsets[n++] = i_block >> ptrs_bits; 184 offsets[n++] = i_block & (ptrs - 1); 185 final = ptrs; 186 } else if (((i_block -= double_blocks) >> (ptrs_bits * 2)) < ptrs) { 187 offsets[n++] = EXT2_TIND_BLOCK; 188 offsets[n++] = i_block >> (ptrs_bits * 2); 189 offsets[n++] = (i_block >> ptrs_bits) & (ptrs - 1); 190 offsets[n++] = i_block & (ptrs - 1); 191 final = ptrs; 192 } else { 193 ext2_msg(inode->i_sb, KERN_WARNING, 194 "warning: %s: block is too big", __func__); 195 } 196 if (boundary) 197 *boundary = final - 1 - (i_block & (ptrs - 1)); 198 199 return n; 200 } 201 202 /** 203 * ext2_get_branch - read the chain of indirect blocks leading to data 204 * @inode: inode in question 205 * @depth: depth of the chain (1 - direct pointer, etc.) 206 * @offsets: offsets of pointers in inode/indirect blocks 207 * @chain: place to store the result 208 * @err: here we store the error value 209 * 210 * Function fills the array of triples <key, p, bh> and returns %NULL 211 * if everything went OK or the pointer to the last filled triple 212 * (incomplete one) otherwise. Upon the return chain[i].key contains 213 * the number of (i+1)-th block in the chain (as it is stored in memory, 214 * i.e. little-endian 32-bit), chain[i].p contains the address of that 215 * number (it points into struct inode for i==0 and into the bh->b_data 216 * for i>0) and chain[i].bh points to the buffer_head of i-th indirect 217 * block for i>0 and NULL for i==0. In other words, it holds the block 218 * numbers of the chain, addresses they were taken from (and where we can 219 * verify that chain did not change) and buffer_heads hosting these 220 * numbers. 221 * 222 * Function stops when it stumbles upon zero pointer (absent block) 223 * (pointer to last triple returned, *@err == 0) 224 * or when it gets an IO error reading an indirect block 225 * (ditto, *@err == -EIO) 226 * or when it notices that chain had been changed while it was reading 227 * (ditto, *@err == -EAGAIN) 228 * or when it reads all @depth-1 indirect blocks successfully and finds 229 * the whole chain, all way to the data (returns %NULL, *err == 0). 230 */ 231 static Indirect *ext2_get_branch(struct inode *inode, 232 int depth, 233 int *offsets, 234 Indirect chain[4], 235 int *err) 236 { 237 struct super_block *sb = inode->i_sb; 238 Indirect *p = chain; 239 struct buffer_head *bh; 240 241 *err = 0; 242 /* i_data is not going away, no lock needed */ 243 add_chain (chain, NULL, EXT2_I(inode)->i_data + *offsets); 244 if (!p->key) 245 goto no_block; 246 while (--depth) { 247 bh = sb_bread(sb, le32_to_cpu(p->key)); 248 if (!bh) 249 goto failure; 250 read_lock(&EXT2_I(inode)->i_meta_lock); 251 if (!verify_chain(chain, p)) 252 goto changed; 253 add_chain(++p, bh, (__le32*)bh->b_data + *++offsets); 254 read_unlock(&EXT2_I(inode)->i_meta_lock); 255 if (!p->key) 256 goto no_block; 257 } 258 return NULL; 259 260 changed: 261 read_unlock(&EXT2_I(inode)->i_meta_lock); 262 brelse(bh); 263 *err = -EAGAIN; 264 goto no_block; 265 failure: 266 *err = -EIO; 267 no_block: 268 return p; 269 } 270 271 /** 272 * ext2_find_near - find a place for allocation with sufficient locality 273 * @inode: owner 274 * @ind: descriptor of indirect block. 275 * 276 * This function returns the preferred place for block allocation. 277 * It is used when heuristic for sequential allocation fails. 278 * Rules are: 279 * + if there is a block to the left of our position - allocate near it. 280 * + if pointer will live in indirect block - allocate near that block. 281 * + if pointer will live in inode - allocate in the same cylinder group. 282 * 283 * In the latter case we colour the starting block by the callers PID to 284 * prevent it from clashing with concurrent allocations for a different inode 285 * in the same block group. The PID is used here so that functionally related 286 * files will be close-by on-disk. 287 * 288 * Caller must make sure that @ind is valid and will stay that way. 289 */ 290 291 static ext2_fsblk_t ext2_find_near(struct inode *inode, Indirect *ind) 292 { 293 struct ext2_inode_info *ei = EXT2_I(inode); 294 __le32 *start = ind->bh ? (__le32 *) ind->bh->b_data : ei->i_data; 295 __le32 *p; 296 ext2_fsblk_t bg_start; 297 ext2_fsblk_t colour; 298 299 /* Try to find previous block */ 300 for (p = ind->p - 1; p >= start; p--) 301 if (*p) 302 return le32_to_cpu(*p); 303 304 /* No such thing, so let's try location of indirect block */ 305 if (ind->bh) 306 return ind->bh->b_blocknr; 307 308 /* 309 * It is going to be referred from inode itself? OK, just put it into 310 * the same cylinder group then. 311 */ 312 bg_start = ext2_group_first_block_no(inode->i_sb, ei->i_block_group); 313 colour = (current->pid % 16) * 314 (EXT2_BLOCKS_PER_GROUP(inode->i_sb) / 16); 315 return bg_start + colour; 316 } 317 318 /** 319 * ext2_find_goal - find a preferred place for allocation. 320 * @inode: owner 321 * @block: block we want 322 * @partial: pointer to the last triple within a chain 323 * 324 * Returns preferred place for a block (the goal). 325 */ 326 327 static inline ext2_fsblk_t ext2_find_goal(struct inode *inode, long block, 328 Indirect *partial) 329 { 330 struct ext2_block_alloc_info *block_i; 331 332 block_i = EXT2_I(inode)->i_block_alloc_info; 333 334 /* 335 * try the heuristic for sequential allocation, 336 * failing that at least try to get decent locality. 337 */ 338 if (block_i && (block == block_i->last_alloc_logical_block + 1) 339 && (block_i->last_alloc_physical_block != 0)) { 340 return block_i->last_alloc_physical_block + 1; 341 } 342 343 return ext2_find_near(inode, partial); 344 } 345 346 /** 347 * ext2_blks_to_allocate: Look up the block map and count the number 348 * of direct blocks need to be allocated for the given branch. 349 * 350 * @branch: chain of indirect blocks 351 * @k: number of blocks need for indirect blocks 352 * @blks: number of data blocks to be mapped. 353 * @blocks_to_boundary: the offset in the indirect block 354 * 355 * return the total number of blocks to be allocate, including the 356 * direct and indirect blocks. 357 */ 358 static int 359 ext2_blks_to_allocate(Indirect * branch, int k, unsigned long blks, 360 int blocks_to_boundary) 361 { 362 unsigned long count = 0; 363 364 /* 365 * Simple case, [t,d]Indirect block(s) has not allocated yet 366 * then it's clear blocks on that path have not allocated 367 */ 368 if (k > 0) { 369 /* right now don't hanel cross boundary allocation */ 370 if (blks < blocks_to_boundary + 1) 371 count += blks; 372 else 373 count += blocks_to_boundary + 1; 374 return count; 375 } 376 377 count++; 378 while (count < blks && count <= blocks_to_boundary 379 && le32_to_cpu(*(branch[0].p + count)) == 0) { 380 count++; 381 } 382 return count; 383 } 384 385 /** 386 * ext2_alloc_blocks: multiple allocate blocks needed for a branch 387 * @indirect_blks: the number of blocks need to allocate for indirect 388 * blocks 389 * 390 * @new_blocks: on return it will store the new block numbers for 391 * the indirect blocks(if needed) and the first direct block, 392 * @blks: on return it will store the total number of allocated 393 * direct blocks 394 */ 395 static int ext2_alloc_blocks(struct inode *inode, 396 ext2_fsblk_t goal, int indirect_blks, int blks, 397 ext2_fsblk_t new_blocks[4], int *err) 398 { 399 int target, i; 400 unsigned long count = 0; 401 int index = 0; 402 ext2_fsblk_t current_block = 0; 403 int ret = 0; 404 405 /* 406 * Here we try to allocate the requested multiple blocks at once, 407 * on a best-effort basis. 408 * To build a branch, we should allocate blocks for 409 * the indirect blocks(if not allocated yet), and at least 410 * the first direct block of this branch. That's the 411 * minimum number of blocks need to allocate(required) 412 */ 413 target = blks + indirect_blks; 414 415 while (1) { 416 count = target; 417 /* allocating blocks for indirect blocks and direct blocks */ 418 current_block = ext2_new_blocks(inode,goal,&count,err); 419 if (*err) 420 goto failed_out; 421 422 target -= count; 423 /* allocate blocks for indirect blocks */ 424 while (index < indirect_blks && count) { 425 new_blocks[index++] = current_block++; 426 count--; 427 } 428 429 if (count > 0) 430 break; 431 } 432 433 /* save the new block number for the first direct block */ 434 new_blocks[index] = current_block; 435 436 /* total number of blocks allocated for direct blocks */ 437 ret = count; 438 *err = 0; 439 return ret; 440 failed_out: 441 for (i = 0; i <index; i++) 442 ext2_free_blocks(inode, new_blocks[i], 1); 443 if (index) 444 mark_inode_dirty(inode); 445 return ret; 446 } 447 448 /** 449 * ext2_alloc_branch - allocate and set up a chain of blocks. 450 * @inode: owner 451 * @num: depth of the chain (number of blocks to allocate) 452 * @offsets: offsets (in the blocks) to store the pointers to next. 453 * @branch: place to store the chain in. 454 * 455 * This function allocates @num blocks, zeroes out all but the last one, 456 * links them into chain and (if we are synchronous) writes them to disk. 457 * In other words, it prepares a branch that can be spliced onto the 458 * inode. It stores the information about that chain in the branch[], in 459 * the same format as ext2_get_branch() would do. We are calling it after 460 * we had read the existing part of chain and partial points to the last 461 * triple of that (one with zero ->key). Upon the exit we have the same 462 * picture as after the successful ext2_get_block(), except that in one 463 * place chain is disconnected - *branch->p is still zero (we did not 464 * set the last link), but branch->key contains the number that should 465 * be placed into *branch->p to fill that gap. 466 * 467 * If allocation fails we free all blocks we've allocated (and forget 468 * their buffer_heads) and return the error value the from failed 469 * ext2_alloc_block() (normally -ENOSPC). Otherwise we set the chain 470 * as described above and return 0. 471 */ 472 473 static int ext2_alloc_branch(struct inode *inode, 474 int indirect_blks, int *blks, ext2_fsblk_t goal, 475 int *offsets, Indirect *branch) 476 { 477 int blocksize = inode->i_sb->s_blocksize; 478 int i, n = 0; 479 int err = 0; 480 struct buffer_head *bh; 481 int num; 482 ext2_fsblk_t new_blocks[4]; 483 ext2_fsblk_t current_block; 484 485 num = ext2_alloc_blocks(inode, goal, indirect_blks, 486 *blks, new_blocks, &err); 487 if (err) 488 return err; 489 490 branch[0].key = cpu_to_le32(new_blocks[0]); 491 /* 492 * metadata blocks and data blocks are allocated. 493 */ 494 for (n = 1; n <= indirect_blks; n++) { 495 /* 496 * Get buffer_head for parent block, zero it out 497 * and set the pointer to new one, then send 498 * parent to disk. 499 */ 500 bh = sb_getblk(inode->i_sb, new_blocks[n-1]); 501 if (unlikely(!bh)) { 502 err = -ENOMEM; 503 goto failed; 504 } 505 branch[n].bh = bh; 506 lock_buffer(bh); 507 memset(bh->b_data, 0, blocksize); 508 branch[n].p = (__le32 *) bh->b_data + offsets[n]; 509 branch[n].key = cpu_to_le32(new_blocks[n]); 510 *branch[n].p = branch[n].key; 511 if ( n == indirect_blks) { 512 current_block = new_blocks[n]; 513 /* 514 * End of chain, update the last new metablock of 515 * the chain to point to the new allocated 516 * data blocks numbers 517 */ 518 for (i=1; i < num; i++) 519 *(branch[n].p + i) = cpu_to_le32(++current_block); 520 } 521 set_buffer_uptodate(bh); 522 unlock_buffer(bh); 523 mark_buffer_dirty_inode(bh, inode); 524 /* We used to sync bh here if IS_SYNC(inode). 525 * But we now rely upon generic_write_sync() 526 * and b_inode_buffers. But not for directories. 527 */ 528 if (S_ISDIR(inode->i_mode) && IS_DIRSYNC(inode)) 529 sync_dirty_buffer(bh); 530 } 531 *blks = num; 532 return err; 533 534 failed: 535 for (i = 1; i < n; i++) 536 bforget(branch[i].bh); 537 for (i = 0; i < indirect_blks; i++) 538 ext2_free_blocks(inode, new_blocks[i], 1); 539 ext2_free_blocks(inode, new_blocks[i], num); 540 return err; 541 } 542 543 /** 544 * ext2_splice_branch - splice the allocated branch onto inode. 545 * @inode: owner 546 * @block: (logical) number of block we are adding 547 * @where: location of missing link 548 * @num: number of indirect blocks we are adding 549 * @blks: number of direct blocks we are adding 550 * 551 * This function fills the missing link and does all housekeeping needed in 552 * inode (->i_blocks, etc.). In case of success we end up with the full 553 * chain to new block and return 0. 554 */ 555 static void ext2_splice_branch(struct inode *inode, 556 long block, Indirect *where, int num, int blks) 557 { 558 int i; 559 struct ext2_block_alloc_info *block_i; 560 ext2_fsblk_t current_block; 561 562 block_i = EXT2_I(inode)->i_block_alloc_info; 563 564 /* XXX LOCKING probably should have i_meta_lock ?*/ 565 /* That's it */ 566 567 *where->p = where->key; 568 569 /* 570 * Update the host buffer_head or inode to point to more just allocated 571 * direct blocks blocks 572 */ 573 if (num == 0 && blks > 1) { 574 current_block = le32_to_cpu(where->key) + 1; 575 for (i = 1; i < blks; i++) 576 *(where->p + i ) = cpu_to_le32(current_block++); 577 } 578 579 /* 580 * update the most recently allocated logical & physical block 581 * in i_block_alloc_info, to assist find the proper goal block for next 582 * allocation 583 */ 584 if (block_i) { 585 block_i->last_alloc_logical_block = block + blks - 1; 586 block_i->last_alloc_physical_block = 587 le32_to_cpu(where[num].key) + blks - 1; 588 } 589 590 /* We are done with atomic stuff, now do the rest of housekeeping */ 591 592 /* had we spliced it onto indirect block? */ 593 if (where->bh) 594 mark_buffer_dirty_inode(where->bh, inode); 595 596 inode->i_ctime = CURRENT_TIME_SEC; 597 mark_inode_dirty(inode); 598 } 599 600 /* 601 * Allocation strategy is simple: if we have to allocate something, we will 602 * have to go the whole way to leaf. So let's do it before attaching anything 603 * to tree, set linkage between the newborn blocks, write them if sync is 604 * required, recheck the path, free and repeat if check fails, otherwise 605 * set the last missing link (that will protect us from any truncate-generated 606 * removals - all blocks on the path are immune now) and possibly force the 607 * write on the parent block. 608 * That has a nice additional property: no special recovery from the failed 609 * allocations is needed - we simply release blocks and do not touch anything 610 * reachable from inode. 611 * 612 * `handle' can be NULL if create == 0. 613 * 614 * return > 0, # of blocks mapped or allocated. 615 * return = 0, if plain lookup failed. 616 * return < 0, error case. 617 */ 618 static int ext2_get_blocks(struct inode *inode, 619 sector_t iblock, unsigned long maxblocks, 620 struct buffer_head *bh_result, 621 int create) 622 { 623 int err = -EIO; 624 int offsets[4]; 625 Indirect chain[4]; 626 Indirect *partial; 627 ext2_fsblk_t goal; 628 int indirect_blks; 629 int blocks_to_boundary = 0; 630 int depth; 631 struct ext2_inode_info *ei = EXT2_I(inode); 632 int count = 0; 633 ext2_fsblk_t first_block = 0; 634 635 depth = ext2_block_to_path(inode,iblock,offsets,&blocks_to_boundary); 636 637 if (depth == 0) 638 return (err); 639 640 partial = ext2_get_branch(inode, depth, offsets, chain, &err); 641 /* Simplest case - block found, no allocation needed */ 642 if (!partial) { 643 first_block = le32_to_cpu(chain[depth - 1].key); 644 clear_buffer_new(bh_result); /* What's this do? */ 645 count++; 646 /*map more blocks*/ 647 while (count < maxblocks && count <= blocks_to_boundary) { 648 ext2_fsblk_t blk; 649 650 if (!verify_chain(chain, chain + depth - 1)) { 651 /* 652 * Indirect block might be removed by 653 * truncate while we were reading it. 654 * Handling of that case: forget what we've 655 * got now, go to reread. 656 */ 657 err = -EAGAIN; 658 count = 0; 659 break; 660 } 661 blk = le32_to_cpu(*(chain[depth-1].p + count)); 662 if (blk == first_block + count) 663 count++; 664 else 665 break; 666 } 667 if (err != -EAGAIN) 668 goto got_it; 669 } 670 671 /* Next simple case - plain lookup or failed read of indirect block */ 672 if (!create || err == -EIO) 673 goto cleanup; 674 675 mutex_lock(&ei->truncate_mutex); 676 /* 677 * If the indirect block is missing while we are reading 678 * the chain(ext2_get_branch() returns -EAGAIN err), or 679 * if the chain has been changed after we grab the semaphore, 680 * (either because another process truncated this branch, or 681 * another get_block allocated this branch) re-grab the chain to see if 682 * the request block has been allocated or not. 683 * 684 * Since we already block the truncate/other get_block 685 * at this point, we will have the current copy of the chain when we 686 * splice the branch into the tree. 687 */ 688 if (err == -EAGAIN || !verify_chain(chain, partial)) { 689 while (partial > chain) { 690 brelse(partial->bh); 691 partial--; 692 } 693 partial = ext2_get_branch(inode, depth, offsets, chain, &err); 694 if (!partial) { 695 count++; 696 mutex_unlock(&ei->truncate_mutex); 697 if (err) 698 goto cleanup; 699 clear_buffer_new(bh_result); 700 goto got_it; 701 } 702 } 703 704 /* 705 * Okay, we need to do block allocation. Lazily initialize the block 706 * allocation info here if necessary 707 */ 708 if (S_ISREG(inode->i_mode) && (!ei->i_block_alloc_info)) 709 ext2_init_block_alloc_info(inode); 710 711 goal = ext2_find_goal(inode, iblock, partial); 712 713 /* the number of blocks need to allocate for [d,t]indirect blocks */ 714 indirect_blks = (chain + depth) - partial - 1; 715 /* 716 * Next look up the indirect map to count the totoal number of 717 * direct blocks to allocate for this branch. 718 */ 719 count = ext2_blks_to_allocate(partial, indirect_blks, 720 maxblocks, blocks_to_boundary); 721 /* 722 * XXX ???? Block out ext2_truncate while we alter the tree 723 */ 724 err = ext2_alloc_branch(inode, indirect_blks, &count, goal, 725 offsets + (partial - chain), partial); 726 727 if (err) { 728 mutex_unlock(&ei->truncate_mutex); 729 goto cleanup; 730 } 731 732 if (ext2_use_xip(inode->i_sb)) { 733 /* 734 * we need to clear the block 735 */ 736 err = ext2_clear_xip_target (inode, 737 le32_to_cpu(chain[depth-1].key)); 738 if (err) { 739 mutex_unlock(&ei->truncate_mutex); 740 goto cleanup; 741 } 742 } 743 744 ext2_splice_branch(inode, iblock, partial, indirect_blks, count); 745 mutex_unlock(&ei->truncate_mutex); 746 set_buffer_new(bh_result); 747 got_it: 748 map_bh(bh_result, inode->i_sb, le32_to_cpu(chain[depth-1].key)); 749 if (count > blocks_to_boundary) 750 set_buffer_boundary(bh_result); 751 err = count; 752 /* Clean up and exit */ 753 partial = chain + depth - 1; /* the whole chain */ 754 cleanup: 755 while (partial > chain) { 756 brelse(partial->bh); 757 partial--; 758 } 759 return err; 760 } 761 762 int ext2_get_block(struct inode *inode, sector_t iblock, struct buffer_head *bh_result, int create) 763 { 764 unsigned max_blocks = bh_result->b_size >> inode->i_blkbits; 765 int ret = ext2_get_blocks(inode, iblock, max_blocks, 766 bh_result, create); 767 if (ret > 0) { 768 bh_result->b_size = (ret << inode->i_blkbits); 769 ret = 0; 770 } 771 return ret; 772 773 } 774 775 int ext2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, 776 u64 start, u64 len) 777 { 778 return generic_block_fiemap(inode, fieinfo, start, len, 779 ext2_get_block); 780 } 781 782 static int ext2_writepage(struct page *page, struct writeback_control *wbc) 783 { 784 return block_write_full_page(page, ext2_get_block, wbc); 785 } 786 787 static int ext2_readpage(struct file *file, struct page *page) 788 { 789 return mpage_readpage(page, ext2_get_block); 790 } 791 792 static int 793 ext2_readpages(struct file *file, struct address_space *mapping, 794 struct list_head *pages, unsigned nr_pages) 795 { 796 return mpage_readpages(mapping, pages, nr_pages, ext2_get_block); 797 } 798 799 static int 800 ext2_write_begin(struct file *file, struct address_space *mapping, 801 loff_t pos, unsigned len, unsigned flags, 802 struct page **pagep, void **fsdata) 803 { 804 int ret; 805 806 ret = block_write_begin(mapping, pos, len, flags, pagep, 807 ext2_get_block); 808 if (ret < 0) 809 ext2_write_failed(mapping, pos + len); 810 return ret; 811 } 812 813 static int ext2_write_end(struct file *file, struct address_space *mapping, 814 loff_t pos, unsigned len, unsigned copied, 815 struct page *page, void *fsdata) 816 { 817 int ret; 818 819 ret = generic_write_end(file, mapping, pos, len, copied, page, fsdata); 820 if (ret < len) 821 ext2_write_failed(mapping, pos + len); 822 return ret; 823 } 824 825 static int 826 ext2_nobh_write_begin(struct file *file, struct address_space *mapping, 827 loff_t pos, unsigned len, unsigned flags, 828 struct page **pagep, void **fsdata) 829 { 830 int ret; 831 832 ret = nobh_write_begin(mapping, pos, len, flags, pagep, fsdata, 833 ext2_get_block); 834 if (ret < 0) 835 ext2_write_failed(mapping, pos + len); 836 return ret; 837 } 838 839 static int ext2_nobh_writepage(struct page *page, 840 struct writeback_control *wbc) 841 { 842 return nobh_writepage(page, ext2_get_block, wbc); 843 } 844 845 static sector_t ext2_bmap(struct address_space *mapping, sector_t block) 846 { 847 return generic_block_bmap(mapping,block,ext2_get_block); 848 } 849 850 static ssize_t 851 ext2_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov, 852 loff_t offset, unsigned long nr_segs) 853 { 854 struct file *file = iocb->ki_filp; 855 struct address_space *mapping = file->f_mapping; 856 struct inode *inode = mapping->host; 857 ssize_t ret; 858 859 ret = blockdev_direct_IO(rw, iocb, inode, iov, offset, nr_segs, 860 ext2_get_block); 861 if (ret < 0 && (rw & WRITE)) 862 ext2_write_failed(mapping, offset + iov_length(iov, nr_segs)); 863 return ret; 864 } 865 866 static int 867 ext2_writepages(struct address_space *mapping, struct writeback_control *wbc) 868 { 869 return mpage_writepages(mapping, wbc, ext2_get_block); 870 } 871 872 const struct address_space_operations ext2_aops = { 873 .readpage = ext2_readpage, 874 .readpages = ext2_readpages, 875 .writepage = ext2_writepage, 876 .write_begin = ext2_write_begin, 877 .write_end = ext2_write_end, 878 .bmap = ext2_bmap, 879 .direct_IO = ext2_direct_IO, 880 .writepages = ext2_writepages, 881 .migratepage = buffer_migrate_page, 882 .is_partially_uptodate = block_is_partially_uptodate, 883 .error_remove_page = generic_error_remove_page, 884 }; 885 886 const struct address_space_operations ext2_aops_xip = { 887 .bmap = ext2_bmap, 888 .get_xip_mem = ext2_get_xip_mem, 889 }; 890 891 const struct address_space_operations ext2_nobh_aops = { 892 .readpage = ext2_readpage, 893 .readpages = ext2_readpages, 894 .writepage = ext2_nobh_writepage, 895 .write_begin = ext2_nobh_write_begin, 896 .write_end = nobh_write_end, 897 .bmap = ext2_bmap, 898 .direct_IO = ext2_direct_IO, 899 .writepages = ext2_writepages, 900 .migratepage = buffer_migrate_page, 901 .error_remove_page = generic_error_remove_page, 902 }; 903 904 /* 905 * Probably it should be a library function... search for first non-zero word 906 * or memcmp with zero_page, whatever is better for particular architecture. 907 * Linus? 908 */ 909 static inline int all_zeroes(__le32 *p, __le32 *q) 910 { 911 while (p < q) 912 if (*p++) 913 return 0; 914 return 1; 915 } 916 917 /** 918 * ext2_find_shared - find the indirect blocks for partial truncation. 919 * @inode: inode in question 920 * @depth: depth of the affected branch 921 * @offsets: offsets of pointers in that branch (see ext2_block_to_path) 922 * @chain: place to store the pointers to partial indirect blocks 923 * @top: place to the (detached) top of branch 924 * 925 * This is a helper function used by ext2_truncate(). 926 * 927 * When we do truncate() we may have to clean the ends of several indirect 928 * blocks but leave the blocks themselves alive. Block is partially 929 * truncated if some data below the new i_size is referred from it (and 930 * it is on the path to the first completely truncated data block, indeed). 931 * We have to free the top of that path along with everything to the right 932 * of the path. Since no allocation past the truncation point is possible 933 * until ext2_truncate() finishes, we may safely do the latter, but top 934 * of branch may require special attention - pageout below the truncation 935 * point might try to populate it. 936 * 937 * We atomically detach the top of branch from the tree, store the block 938 * number of its root in *@top, pointers to buffer_heads of partially 939 * truncated blocks - in @chain[].bh and pointers to their last elements 940 * that should not be removed - in @chain[].p. Return value is the pointer 941 * to last filled element of @chain. 942 * 943 * The work left to caller to do the actual freeing of subtrees: 944 * a) free the subtree starting from *@top 945 * b) free the subtrees whose roots are stored in 946 * (@chain[i].p+1 .. end of @chain[i].bh->b_data) 947 * c) free the subtrees growing from the inode past the @chain[0].p 948 * (no partially truncated stuff there). 949 */ 950 951 static Indirect *ext2_find_shared(struct inode *inode, 952 int depth, 953 int offsets[4], 954 Indirect chain[4], 955 __le32 *top) 956 { 957 Indirect *partial, *p; 958 int k, err; 959 960 *top = 0; 961 for (k = depth; k > 1 && !offsets[k-1]; k--) 962 ; 963 partial = ext2_get_branch(inode, k, offsets, chain, &err); 964 if (!partial) 965 partial = chain + k-1; 966 /* 967 * If the branch acquired continuation since we've looked at it - 968 * fine, it should all survive and (new) top doesn't belong to us. 969 */ 970 write_lock(&EXT2_I(inode)->i_meta_lock); 971 if (!partial->key && *partial->p) { 972 write_unlock(&EXT2_I(inode)->i_meta_lock); 973 goto no_top; 974 } 975 for (p=partial; p>chain && all_zeroes((__le32*)p->bh->b_data,p->p); p--) 976 ; 977 /* 978 * OK, we've found the last block that must survive. The rest of our 979 * branch should be detached before unlocking. However, if that rest 980 * of branch is all ours and does not grow immediately from the inode 981 * it's easier to cheat and just decrement partial->p. 982 */ 983 if (p == chain + k - 1 && p > chain) { 984 p->p--; 985 } else { 986 *top = *p->p; 987 *p->p = 0; 988 } 989 write_unlock(&EXT2_I(inode)->i_meta_lock); 990 991 while(partial > p) 992 { 993 brelse(partial->bh); 994 partial--; 995 } 996 no_top: 997 return partial; 998 } 999 1000 /** 1001 * ext2_free_data - free a list of data blocks 1002 * @inode: inode we are dealing with 1003 * @p: array of block numbers 1004 * @q: points immediately past the end of array 1005 * 1006 * We are freeing all blocks referred from that array (numbers are 1007 * stored as little-endian 32-bit) and updating @inode->i_blocks 1008 * appropriately. 1009 */ 1010 static inline void ext2_free_data(struct inode *inode, __le32 *p, __le32 *q) 1011 { 1012 unsigned long block_to_free = 0, count = 0; 1013 unsigned long nr; 1014 1015 for ( ; p < q ; p++) { 1016 nr = le32_to_cpu(*p); 1017 if (nr) { 1018 *p = 0; 1019 /* accumulate blocks to free if they're contiguous */ 1020 if (count == 0) 1021 goto free_this; 1022 else if (block_to_free == nr - count) 1023 count++; 1024 else { 1025 ext2_free_blocks (inode, block_to_free, count); 1026 mark_inode_dirty(inode); 1027 free_this: 1028 block_to_free = nr; 1029 count = 1; 1030 } 1031 } 1032 } 1033 if (count > 0) { 1034 ext2_free_blocks (inode, block_to_free, count); 1035 mark_inode_dirty(inode); 1036 } 1037 } 1038 1039 /** 1040 * ext2_free_branches - free an array of branches 1041 * @inode: inode we are dealing with 1042 * @p: array of block numbers 1043 * @q: pointer immediately past the end of array 1044 * @depth: depth of the branches to free 1045 * 1046 * We are freeing all blocks referred from these branches (numbers are 1047 * stored as little-endian 32-bit) and updating @inode->i_blocks 1048 * appropriately. 1049 */ 1050 static void ext2_free_branches(struct inode *inode, __le32 *p, __le32 *q, int depth) 1051 { 1052 struct buffer_head * bh; 1053 unsigned long nr; 1054 1055 if (depth--) { 1056 int addr_per_block = EXT2_ADDR_PER_BLOCK(inode->i_sb); 1057 for ( ; p < q ; p++) { 1058 nr = le32_to_cpu(*p); 1059 if (!nr) 1060 continue; 1061 *p = 0; 1062 bh = sb_bread(inode->i_sb, nr); 1063 /* 1064 * A read failure? Report error and clear slot 1065 * (should be rare). 1066 */ 1067 if (!bh) { 1068 ext2_error(inode->i_sb, "ext2_free_branches", 1069 "Read failure, inode=%ld, block=%ld", 1070 inode->i_ino, nr); 1071 continue; 1072 } 1073 ext2_free_branches(inode, 1074 (__le32*)bh->b_data, 1075 (__le32*)bh->b_data + addr_per_block, 1076 depth); 1077 bforget(bh); 1078 ext2_free_blocks(inode, nr, 1); 1079 mark_inode_dirty(inode); 1080 } 1081 } else 1082 ext2_free_data(inode, p, q); 1083 } 1084 1085 static void __ext2_truncate_blocks(struct inode *inode, loff_t offset) 1086 { 1087 __le32 *i_data = EXT2_I(inode)->i_data; 1088 struct ext2_inode_info *ei = EXT2_I(inode); 1089 int addr_per_block = EXT2_ADDR_PER_BLOCK(inode->i_sb); 1090 int offsets[4]; 1091 Indirect chain[4]; 1092 Indirect *partial; 1093 __le32 nr = 0; 1094 int n; 1095 long iblock; 1096 unsigned blocksize; 1097 blocksize = inode->i_sb->s_blocksize; 1098 iblock = (offset + blocksize-1) >> EXT2_BLOCK_SIZE_BITS(inode->i_sb); 1099 1100 n = ext2_block_to_path(inode, iblock, offsets, NULL); 1101 if (n == 0) 1102 return; 1103 1104 /* 1105 * From here we block out all ext2_get_block() callers who want to 1106 * modify the block allocation tree. 1107 */ 1108 mutex_lock(&ei->truncate_mutex); 1109 1110 if (n == 1) { 1111 ext2_free_data(inode, i_data+offsets[0], 1112 i_data + EXT2_NDIR_BLOCKS); 1113 goto do_indirects; 1114 } 1115 1116 partial = ext2_find_shared(inode, n, offsets, chain, &nr); 1117 /* Kill the top of shared branch (already detached) */ 1118 if (nr) { 1119 if (partial == chain) 1120 mark_inode_dirty(inode); 1121 else 1122 mark_buffer_dirty_inode(partial->bh, inode); 1123 ext2_free_branches(inode, &nr, &nr+1, (chain+n-1) - partial); 1124 } 1125 /* Clear the ends of indirect blocks on the shared branch */ 1126 while (partial > chain) { 1127 ext2_free_branches(inode, 1128 partial->p + 1, 1129 (__le32*)partial->bh->b_data+addr_per_block, 1130 (chain+n-1) - partial); 1131 mark_buffer_dirty_inode(partial->bh, inode); 1132 brelse (partial->bh); 1133 partial--; 1134 } 1135 do_indirects: 1136 /* Kill the remaining (whole) subtrees */ 1137 switch (offsets[0]) { 1138 default: 1139 nr = i_data[EXT2_IND_BLOCK]; 1140 if (nr) { 1141 i_data[EXT2_IND_BLOCK] = 0; 1142 mark_inode_dirty(inode); 1143 ext2_free_branches(inode, &nr, &nr+1, 1); 1144 } 1145 case EXT2_IND_BLOCK: 1146 nr = i_data[EXT2_DIND_BLOCK]; 1147 if (nr) { 1148 i_data[EXT2_DIND_BLOCK] = 0; 1149 mark_inode_dirty(inode); 1150 ext2_free_branches(inode, &nr, &nr+1, 2); 1151 } 1152 case EXT2_DIND_BLOCK: 1153 nr = i_data[EXT2_TIND_BLOCK]; 1154 if (nr) { 1155 i_data[EXT2_TIND_BLOCK] = 0; 1156 mark_inode_dirty(inode); 1157 ext2_free_branches(inode, &nr, &nr+1, 3); 1158 } 1159 case EXT2_TIND_BLOCK: 1160 ; 1161 } 1162 1163 ext2_discard_reservation(inode); 1164 1165 mutex_unlock(&ei->truncate_mutex); 1166 } 1167 1168 static void ext2_truncate_blocks(struct inode *inode, loff_t offset) 1169 { 1170 /* 1171 * XXX: it seems like a bug here that we don't allow 1172 * IS_APPEND inode to have blocks-past-i_size trimmed off. 1173 * review and fix this. 1174 * 1175 * Also would be nice to be able to handle IO errors and such, 1176 * but that's probably too much to ask. 1177 */ 1178 if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || 1179 S_ISLNK(inode->i_mode))) 1180 return; 1181 if (ext2_inode_is_fast_symlink(inode)) 1182 return; 1183 if (IS_APPEND(inode) || IS_IMMUTABLE(inode)) 1184 return; 1185 __ext2_truncate_blocks(inode, offset); 1186 } 1187 1188 static int ext2_setsize(struct inode *inode, loff_t newsize) 1189 { 1190 int error; 1191 1192 if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || 1193 S_ISLNK(inode->i_mode))) 1194 return -EINVAL; 1195 if (ext2_inode_is_fast_symlink(inode)) 1196 return -EINVAL; 1197 if (IS_APPEND(inode) || IS_IMMUTABLE(inode)) 1198 return -EPERM; 1199 1200 inode_dio_wait(inode); 1201 1202 if (mapping_is_xip(inode->i_mapping)) 1203 error = xip_truncate_page(inode->i_mapping, newsize); 1204 else if (test_opt(inode->i_sb, NOBH)) 1205 error = nobh_truncate_page(inode->i_mapping, 1206 newsize, ext2_get_block); 1207 else 1208 error = block_truncate_page(inode->i_mapping, 1209 newsize, ext2_get_block); 1210 if (error) 1211 return error; 1212 1213 truncate_setsize(inode, newsize); 1214 __ext2_truncate_blocks(inode, newsize); 1215 1216 inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC; 1217 if (inode_needs_sync(inode)) { 1218 sync_mapping_buffers(inode->i_mapping); 1219 sync_inode_metadata(inode, 1); 1220 } else { 1221 mark_inode_dirty(inode); 1222 } 1223 1224 return 0; 1225 } 1226 1227 static struct ext2_inode *ext2_get_inode(struct super_block *sb, ino_t ino, 1228 struct buffer_head **p) 1229 { 1230 struct buffer_head * bh; 1231 unsigned long block_group; 1232 unsigned long block; 1233 unsigned long offset; 1234 struct ext2_group_desc * gdp; 1235 1236 *p = NULL; 1237 if ((ino != EXT2_ROOT_INO && ino < EXT2_FIRST_INO(sb)) || 1238 ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count)) 1239 goto Einval; 1240 1241 block_group = (ino - 1) / EXT2_INODES_PER_GROUP(sb); 1242 gdp = ext2_get_group_desc(sb, block_group, NULL); 1243 if (!gdp) 1244 goto Egdp; 1245 /* 1246 * Figure out the offset within the block group inode table 1247 */ 1248 offset = ((ino - 1) % EXT2_INODES_PER_GROUP(sb)) * EXT2_INODE_SIZE(sb); 1249 block = le32_to_cpu(gdp->bg_inode_table) + 1250 (offset >> EXT2_BLOCK_SIZE_BITS(sb)); 1251 if (!(bh = sb_bread(sb, block))) 1252 goto Eio; 1253 1254 *p = bh; 1255 offset &= (EXT2_BLOCK_SIZE(sb) - 1); 1256 return (struct ext2_inode *) (bh->b_data + offset); 1257 1258 Einval: 1259 ext2_error(sb, "ext2_get_inode", "bad inode number: %lu", 1260 (unsigned long) ino); 1261 return ERR_PTR(-EINVAL); 1262 Eio: 1263 ext2_error(sb, "ext2_get_inode", 1264 "unable to read inode block - inode=%lu, block=%lu", 1265 (unsigned long) ino, block); 1266 Egdp: 1267 return ERR_PTR(-EIO); 1268 } 1269 1270 void ext2_set_inode_flags(struct inode *inode) 1271 { 1272 unsigned int flags = EXT2_I(inode)->i_flags; 1273 1274 inode->i_flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC); 1275 if (flags & EXT2_SYNC_FL) 1276 inode->i_flags |= S_SYNC; 1277 if (flags & EXT2_APPEND_FL) 1278 inode->i_flags |= S_APPEND; 1279 if (flags & EXT2_IMMUTABLE_FL) 1280 inode->i_flags |= S_IMMUTABLE; 1281 if (flags & EXT2_NOATIME_FL) 1282 inode->i_flags |= S_NOATIME; 1283 if (flags & EXT2_DIRSYNC_FL) 1284 inode->i_flags |= S_DIRSYNC; 1285 } 1286 1287 /* Propagate flags from i_flags to EXT2_I(inode)->i_flags */ 1288 void ext2_get_inode_flags(struct ext2_inode_info *ei) 1289 { 1290 unsigned int flags = ei->vfs_inode.i_flags; 1291 1292 ei->i_flags &= ~(EXT2_SYNC_FL|EXT2_APPEND_FL| 1293 EXT2_IMMUTABLE_FL|EXT2_NOATIME_FL|EXT2_DIRSYNC_FL); 1294 if (flags & S_SYNC) 1295 ei->i_flags |= EXT2_SYNC_FL; 1296 if (flags & S_APPEND) 1297 ei->i_flags |= EXT2_APPEND_FL; 1298 if (flags & S_IMMUTABLE) 1299 ei->i_flags |= EXT2_IMMUTABLE_FL; 1300 if (flags & S_NOATIME) 1301 ei->i_flags |= EXT2_NOATIME_FL; 1302 if (flags & S_DIRSYNC) 1303 ei->i_flags |= EXT2_DIRSYNC_FL; 1304 } 1305 1306 struct inode *ext2_iget (struct super_block *sb, unsigned long ino) 1307 { 1308 struct ext2_inode_info *ei; 1309 struct buffer_head * bh; 1310 struct ext2_inode *raw_inode; 1311 struct inode *inode; 1312 long ret = -EIO; 1313 int n; 1314 uid_t i_uid; 1315 gid_t i_gid; 1316 1317 inode = iget_locked(sb, ino); 1318 if (!inode) 1319 return ERR_PTR(-ENOMEM); 1320 if (!(inode->i_state & I_NEW)) 1321 return inode; 1322 1323 ei = EXT2_I(inode); 1324 ei->i_block_alloc_info = NULL; 1325 1326 raw_inode = ext2_get_inode(inode->i_sb, ino, &bh); 1327 if (IS_ERR(raw_inode)) { 1328 ret = PTR_ERR(raw_inode); 1329 goto bad_inode; 1330 } 1331 1332 inode->i_mode = le16_to_cpu(raw_inode->i_mode); 1333 i_uid = (uid_t)le16_to_cpu(raw_inode->i_uid_low); 1334 i_gid = (gid_t)le16_to_cpu(raw_inode->i_gid_low); 1335 if (!(test_opt (inode->i_sb, NO_UID32))) { 1336 i_uid |= le16_to_cpu(raw_inode->i_uid_high) << 16; 1337 i_gid |= le16_to_cpu(raw_inode->i_gid_high) << 16; 1338 } 1339 i_uid_write(inode, i_uid); 1340 i_gid_write(inode, i_gid); 1341 set_nlink(inode, le16_to_cpu(raw_inode->i_links_count)); 1342 inode->i_size = le32_to_cpu(raw_inode->i_size); 1343 inode->i_atime.tv_sec = (signed)le32_to_cpu(raw_inode->i_atime); 1344 inode->i_ctime.tv_sec = (signed)le32_to_cpu(raw_inode->i_ctime); 1345 inode->i_mtime.tv_sec = (signed)le32_to_cpu(raw_inode->i_mtime); 1346 inode->i_atime.tv_nsec = inode->i_mtime.tv_nsec = inode->i_ctime.tv_nsec = 0; 1347 ei->i_dtime = le32_to_cpu(raw_inode->i_dtime); 1348 /* We now have enough fields to check if the inode was active or not. 1349 * This is needed because nfsd might try to access dead inodes 1350 * the test is that same one that e2fsck uses 1351 * NeilBrown 1999oct15 1352 */ 1353 if (inode->i_nlink == 0 && (inode->i_mode == 0 || ei->i_dtime)) { 1354 /* this inode is deleted */ 1355 brelse (bh); 1356 ret = -ESTALE; 1357 goto bad_inode; 1358 } 1359 inode->i_blocks = le32_to_cpu(raw_inode->i_blocks); 1360 ei->i_flags = le32_to_cpu(raw_inode->i_flags); 1361 ei->i_faddr = le32_to_cpu(raw_inode->i_faddr); 1362 ei->i_frag_no = raw_inode->i_frag; 1363 ei->i_frag_size = raw_inode->i_fsize; 1364 ei->i_file_acl = le32_to_cpu(raw_inode->i_file_acl); 1365 ei->i_dir_acl = 0; 1366 if (S_ISREG(inode->i_mode)) 1367 inode->i_size |= ((__u64)le32_to_cpu(raw_inode->i_size_high)) << 32; 1368 else 1369 ei->i_dir_acl = le32_to_cpu(raw_inode->i_dir_acl); 1370 ei->i_dtime = 0; 1371 inode->i_generation = le32_to_cpu(raw_inode->i_generation); 1372 ei->i_state = 0; 1373 ei->i_block_group = (ino - 1) / EXT2_INODES_PER_GROUP(inode->i_sb); 1374 ei->i_dir_start_lookup = 0; 1375 1376 /* 1377 * NOTE! The in-memory inode i_data array is in little-endian order 1378 * even on big-endian machines: we do NOT byteswap the block numbers! 1379 */ 1380 for (n = 0; n < EXT2_N_BLOCKS; n++) 1381 ei->i_data[n] = raw_inode->i_block[n]; 1382 1383 if (S_ISREG(inode->i_mode)) { 1384 inode->i_op = &ext2_file_inode_operations; 1385 if (ext2_use_xip(inode->i_sb)) { 1386 inode->i_mapping->a_ops = &ext2_aops_xip; 1387 inode->i_fop = &ext2_xip_file_operations; 1388 } else if (test_opt(inode->i_sb, NOBH)) { 1389 inode->i_mapping->a_ops = &ext2_nobh_aops; 1390 inode->i_fop = &ext2_file_operations; 1391 } else { 1392 inode->i_mapping->a_ops = &ext2_aops; 1393 inode->i_fop = &ext2_file_operations; 1394 } 1395 } else if (S_ISDIR(inode->i_mode)) { 1396 inode->i_op = &ext2_dir_inode_operations; 1397 inode->i_fop = &ext2_dir_operations; 1398 if (test_opt(inode->i_sb, NOBH)) 1399 inode->i_mapping->a_ops = &ext2_nobh_aops; 1400 else 1401 inode->i_mapping->a_ops = &ext2_aops; 1402 } else if (S_ISLNK(inode->i_mode)) { 1403 if (ext2_inode_is_fast_symlink(inode)) { 1404 inode->i_op = &ext2_fast_symlink_inode_operations; 1405 nd_terminate_link(ei->i_data, inode->i_size, 1406 sizeof(ei->i_data) - 1); 1407 } else { 1408 inode->i_op = &ext2_symlink_inode_operations; 1409 if (test_opt(inode->i_sb, NOBH)) 1410 inode->i_mapping->a_ops = &ext2_nobh_aops; 1411 else 1412 inode->i_mapping->a_ops = &ext2_aops; 1413 } 1414 } else { 1415 inode->i_op = &ext2_special_inode_operations; 1416 if (raw_inode->i_block[0]) 1417 init_special_inode(inode, inode->i_mode, 1418 old_decode_dev(le32_to_cpu(raw_inode->i_block[0]))); 1419 else 1420 init_special_inode(inode, inode->i_mode, 1421 new_decode_dev(le32_to_cpu(raw_inode->i_block[1]))); 1422 } 1423 brelse (bh); 1424 ext2_set_inode_flags(inode); 1425 unlock_new_inode(inode); 1426 return inode; 1427 1428 bad_inode: 1429 iget_failed(inode); 1430 return ERR_PTR(ret); 1431 } 1432 1433 static int __ext2_write_inode(struct inode *inode, int do_sync) 1434 { 1435 struct ext2_inode_info *ei = EXT2_I(inode); 1436 struct super_block *sb = inode->i_sb; 1437 ino_t ino = inode->i_ino; 1438 uid_t uid = i_uid_read(inode); 1439 gid_t gid = i_gid_read(inode); 1440 struct buffer_head * bh; 1441 struct ext2_inode * raw_inode = ext2_get_inode(sb, ino, &bh); 1442 int n; 1443 int err = 0; 1444 1445 if (IS_ERR(raw_inode)) 1446 return -EIO; 1447 1448 /* For fields not not tracking in the in-memory inode, 1449 * initialise them to zero for new inodes. */ 1450 if (ei->i_state & EXT2_STATE_NEW) 1451 memset(raw_inode, 0, EXT2_SB(sb)->s_inode_size); 1452 1453 ext2_get_inode_flags(ei); 1454 raw_inode->i_mode = cpu_to_le16(inode->i_mode); 1455 if (!(test_opt(sb, NO_UID32))) { 1456 raw_inode->i_uid_low = cpu_to_le16(low_16_bits(uid)); 1457 raw_inode->i_gid_low = cpu_to_le16(low_16_bits(gid)); 1458 /* 1459 * Fix up interoperability with old kernels. Otherwise, old inodes get 1460 * re-used with the upper 16 bits of the uid/gid intact 1461 */ 1462 if (!ei->i_dtime) { 1463 raw_inode->i_uid_high = cpu_to_le16(high_16_bits(uid)); 1464 raw_inode->i_gid_high = cpu_to_le16(high_16_bits(gid)); 1465 } else { 1466 raw_inode->i_uid_high = 0; 1467 raw_inode->i_gid_high = 0; 1468 } 1469 } else { 1470 raw_inode->i_uid_low = cpu_to_le16(fs_high2lowuid(uid)); 1471 raw_inode->i_gid_low = cpu_to_le16(fs_high2lowgid(gid)); 1472 raw_inode->i_uid_high = 0; 1473 raw_inode->i_gid_high = 0; 1474 } 1475 raw_inode->i_links_count = cpu_to_le16(inode->i_nlink); 1476 raw_inode->i_size = cpu_to_le32(inode->i_size); 1477 raw_inode->i_atime = cpu_to_le32(inode->i_atime.tv_sec); 1478 raw_inode->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec); 1479 raw_inode->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec); 1480 1481 raw_inode->i_blocks = cpu_to_le32(inode->i_blocks); 1482 raw_inode->i_dtime = cpu_to_le32(ei->i_dtime); 1483 raw_inode->i_flags = cpu_to_le32(ei->i_flags); 1484 raw_inode->i_faddr = cpu_to_le32(ei->i_faddr); 1485 raw_inode->i_frag = ei->i_frag_no; 1486 raw_inode->i_fsize = ei->i_frag_size; 1487 raw_inode->i_file_acl = cpu_to_le32(ei->i_file_acl); 1488 if (!S_ISREG(inode->i_mode)) 1489 raw_inode->i_dir_acl = cpu_to_le32(ei->i_dir_acl); 1490 else { 1491 raw_inode->i_size_high = cpu_to_le32(inode->i_size >> 32); 1492 if (inode->i_size > 0x7fffffffULL) { 1493 if (!EXT2_HAS_RO_COMPAT_FEATURE(sb, 1494 EXT2_FEATURE_RO_COMPAT_LARGE_FILE) || 1495 EXT2_SB(sb)->s_es->s_rev_level == 1496 cpu_to_le32(EXT2_GOOD_OLD_REV)) { 1497 /* If this is the first large file 1498 * created, add a flag to the superblock. 1499 */ 1500 spin_lock(&EXT2_SB(sb)->s_lock); 1501 ext2_update_dynamic_rev(sb); 1502 EXT2_SET_RO_COMPAT_FEATURE(sb, 1503 EXT2_FEATURE_RO_COMPAT_LARGE_FILE); 1504 spin_unlock(&EXT2_SB(sb)->s_lock); 1505 ext2_write_super(sb); 1506 } 1507 } 1508 } 1509 1510 raw_inode->i_generation = cpu_to_le32(inode->i_generation); 1511 if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) { 1512 if (old_valid_dev(inode->i_rdev)) { 1513 raw_inode->i_block[0] = 1514 cpu_to_le32(old_encode_dev(inode->i_rdev)); 1515 raw_inode->i_block[1] = 0; 1516 } else { 1517 raw_inode->i_block[0] = 0; 1518 raw_inode->i_block[1] = 1519 cpu_to_le32(new_encode_dev(inode->i_rdev)); 1520 raw_inode->i_block[2] = 0; 1521 } 1522 } else for (n = 0; n < EXT2_N_BLOCKS; n++) 1523 raw_inode->i_block[n] = ei->i_data[n]; 1524 mark_buffer_dirty(bh); 1525 if (do_sync) { 1526 sync_dirty_buffer(bh); 1527 if (buffer_req(bh) && !buffer_uptodate(bh)) { 1528 printk ("IO error syncing ext2 inode [%s:%08lx]\n", 1529 sb->s_id, (unsigned long) ino); 1530 err = -EIO; 1531 } 1532 } 1533 ei->i_state &= ~EXT2_STATE_NEW; 1534 brelse (bh); 1535 return err; 1536 } 1537 1538 int ext2_write_inode(struct inode *inode, struct writeback_control *wbc) 1539 { 1540 return __ext2_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL); 1541 } 1542 1543 int ext2_setattr(struct dentry *dentry, struct iattr *iattr) 1544 { 1545 struct inode *inode = dentry->d_inode; 1546 int error; 1547 1548 error = inode_change_ok(inode, iattr); 1549 if (error) 1550 return error; 1551 1552 if (is_quota_modification(inode, iattr)) 1553 dquot_initialize(inode); 1554 if ((iattr->ia_valid & ATTR_UID && !uid_eq(iattr->ia_uid, inode->i_uid)) || 1555 (iattr->ia_valid & ATTR_GID && !gid_eq(iattr->ia_gid, inode->i_gid))) { 1556 error = dquot_transfer(inode, iattr); 1557 if (error) 1558 return error; 1559 } 1560 if (iattr->ia_valid & ATTR_SIZE && iattr->ia_size != inode->i_size) { 1561 error = ext2_setsize(inode, iattr->ia_size); 1562 if (error) 1563 return error; 1564 } 1565 setattr_copy(inode, iattr); 1566 if (iattr->ia_valid & ATTR_MODE) 1567 error = ext2_acl_chmod(inode); 1568 mark_inode_dirty(inode); 1569 1570 return error; 1571 } 1572