1 /* 2 * linux/fs/ext2/inode.c 3 * 4 * Copyright (C) 1992, 1993, 1994, 1995 5 * Remy Card (card@masi.ibp.fr) 6 * Laboratoire MASI - Institut Blaise Pascal 7 * Universite Pierre et Marie Curie (Paris VI) 8 * 9 * from 10 * 11 * linux/fs/minix/inode.c 12 * 13 * Copyright (C) 1991, 1992 Linus Torvalds 14 * 15 * Goal-directed block allocation by Stephen Tweedie 16 * (sct@dcs.ed.ac.uk), 1993, 1998 17 * Big-endian to little-endian byte-swapping/bitmaps by 18 * David S. Miller (davem@caip.rutgers.edu), 1995 19 * 64-bit file support on 64-bit platforms by Jakub Jelinek 20 * (jj@sunsite.ms.mff.cuni.cz) 21 * 22 * Assorted race fixes, rewrite of ext2_get_block() by Al Viro, 2000 23 */ 24 25 #include <linux/time.h> 26 #include <linux/highuid.h> 27 #include <linux/pagemap.h> 28 #include <linux/quotaops.h> 29 #include <linux/writeback.h> 30 #include <linux/buffer_head.h> 31 #include <linux/mpage.h> 32 #include <linux/fiemap.h> 33 #include <linux/namei.h> 34 #include "ext2.h" 35 #include "acl.h" 36 #include "xip.h" 37 38 static int __ext2_write_inode(struct inode *inode, int do_sync); 39 40 /* 41 * Test whether an inode is a fast symlink. 42 */ 43 static inline int ext2_inode_is_fast_symlink(struct inode *inode) 44 { 45 int ea_blocks = EXT2_I(inode)->i_file_acl ? 46 (inode->i_sb->s_blocksize >> 9) : 0; 47 48 return (S_ISLNK(inode->i_mode) && 49 inode->i_blocks - ea_blocks == 0); 50 } 51 52 static void ext2_truncate_blocks(struct inode *inode, loff_t offset); 53 54 static void ext2_write_failed(struct address_space *mapping, loff_t to) 55 { 56 struct inode *inode = mapping->host; 57 58 if (to > inode->i_size) { 59 truncate_pagecache(inode, to, inode->i_size); 60 ext2_truncate_blocks(inode, inode->i_size); 61 } 62 } 63 64 /* 65 * Called at the last iput() if i_nlink is zero. 66 */ 67 void ext2_evict_inode(struct inode * inode) 68 { 69 struct ext2_block_alloc_info *rsv; 70 int want_delete = 0; 71 72 if (!inode->i_nlink && !is_bad_inode(inode)) { 73 want_delete = 1; 74 dquot_initialize(inode); 75 } else { 76 dquot_drop(inode); 77 } 78 79 truncate_inode_pages(&inode->i_data, 0); 80 81 if (want_delete) { 82 /* set dtime */ 83 EXT2_I(inode)->i_dtime = get_seconds(); 84 mark_inode_dirty(inode); 85 __ext2_write_inode(inode, inode_needs_sync(inode)); 86 /* truncate to 0 */ 87 inode->i_size = 0; 88 if (inode->i_blocks) 89 ext2_truncate_blocks(inode, 0); 90 } 91 92 invalidate_inode_buffers(inode); 93 end_writeback(inode); 94 95 ext2_discard_reservation(inode); 96 rsv = EXT2_I(inode)->i_block_alloc_info; 97 EXT2_I(inode)->i_block_alloc_info = NULL; 98 if (unlikely(rsv)) 99 kfree(rsv); 100 101 if (want_delete) 102 ext2_free_inode(inode); 103 } 104 105 typedef struct { 106 __le32 *p; 107 __le32 key; 108 struct buffer_head *bh; 109 } Indirect; 110 111 static inline void add_chain(Indirect *p, struct buffer_head *bh, __le32 *v) 112 { 113 p->key = *(p->p = v); 114 p->bh = bh; 115 } 116 117 static inline int verify_chain(Indirect *from, Indirect *to) 118 { 119 while (from <= to && from->key == *from->p) 120 from++; 121 return (from > to); 122 } 123 124 /** 125 * ext2_block_to_path - parse the block number into array of offsets 126 * @inode: inode in question (we are only interested in its superblock) 127 * @i_block: block number to be parsed 128 * @offsets: array to store the offsets in 129 * @boundary: set this non-zero if the referred-to block is likely to be 130 * followed (on disk) by an indirect block. 131 * To store the locations of file's data ext2 uses a data structure common 132 * for UNIX filesystems - tree of pointers anchored in the inode, with 133 * data blocks at leaves and indirect blocks in intermediate nodes. 134 * This function translates the block number into path in that tree - 135 * return value is the path length and @offsets[n] is the offset of 136 * pointer to (n+1)th node in the nth one. If @block is out of range 137 * (negative or too large) warning is printed and zero returned. 138 * 139 * Note: function doesn't find node addresses, so no IO is needed. All 140 * we need to know is the capacity of indirect blocks (taken from the 141 * inode->i_sb). 142 */ 143 144 /* 145 * Portability note: the last comparison (check that we fit into triple 146 * indirect block) is spelled differently, because otherwise on an 147 * architecture with 32-bit longs and 8Kb pages we might get into trouble 148 * if our filesystem had 8Kb blocks. We might use long long, but that would 149 * kill us on x86. Oh, well, at least the sign propagation does not matter - 150 * i_block would have to be negative in the very beginning, so we would not 151 * get there at all. 152 */ 153 154 static int ext2_block_to_path(struct inode *inode, 155 long i_block, int offsets[4], int *boundary) 156 { 157 int ptrs = EXT2_ADDR_PER_BLOCK(inode->i_sb); 158 int ptrs_bits = EXT2_ADDR_PER_BLOCK_BITS(inode->i_sb); 159 const long direct_blocks = EXT2_NDIR_BLOCKS, 160 indirect_blocks = ptrs, 161 double_blocks = (1 << (ptrs_bits * 2)); 162 int n = 0; 163 int final = 0; 164 165 if (i_block < 0) { 166 ext2_msg(inode->i_sb, KERN_WARNING, 167 "warning: %s: block < 0", __func__); 168 } else if (i_block < direct_blocks) { 169 offsets[n++] = i_block; 170 final = direct_blocks; 171 } else if ( (i_block -= direct_blocks) < indirect_blocks) { 172 offsets[n++] = EXT2_IND_BLOCK; 173 offsets[n++] = i_block; 174 final = ptrs; 175 } else if ((i_block -= indirect_blocks) < double_blocks) { 176 offsets[n++] = EXT2_DIND_BLOCK; 177 offsets[n++] = i_block >> ptrs_bits; 178 offsets[n++] = i_block & (ptrs - 1); 179 final = ptrs; 180 } else if (((i_block -= double_blocks) >> (ptrs_bits * 2)) < ptrs) { 181 offsets[n++] = EXT2_TIND_BLOCK; 182 offsets[n++] = i_block >> (ptrs_bits * 2); 183 offsets[n++] = (i_block >> ptrs_bits) & (ptrs - 1); 184 offsets[n++] = i_block & (ptrs - 1); 185 final = ptrs; 186 } else { 187 ext2_msg(inode->i_sb, KERN_WARNING, 188 "warning: %s: block is too big", __func__); 189 } 190 if (boundary) 191 *boundary = final - 1 - (i_block & (ptrs - 1)); 192 193 return n; 194 } 195 196 /** 197 * ext2_get_branch - read the chain of indirect blocks leading to data 198 * @inode: inode in question 199 * @depth: depth of the chain (1 - direct pointer, etc.) 200 * @offsets: offsets of pointers in inode/indirect blocks 201 * @chain: place to store the result 202 * @err: here we store the error value 203 * 204 * Function fills the array of triples <key, p, bh> and returns %NULL 205 * if everything went OK or the pointer to the last filled triple 206 * (incomplete one) otherwise. Upon the return chain[i].key contains 207 * the number of (i+1)-th block in the chain (as it is stored in memory, 208 * i.e. little-endian 32-bit), chain[i].p contains the address of that 209 * number (it points into struct inode for i==0 and into the bh->b_data 210 * for i>0) and chain[i].bh points to the buffer_head of i-th indirect 211 * block for i>0 and NULL for i==0. In other words, it holds the block 212 * numbers of the chain, addresses they were taken from (and where we can 213 * verify that chain did not change) and buffer_heads hosting these 214 * numbers. 215 * 216 * Function stops when it stumbles upon zero pointer (absent block) 217 * (pointer to last triple returned, *@err == 0) 218 * or when it gets an IO error reading an indirect block 219 * (ditto, *@err == -EIO) 220 * or when it notices that chain had been changed while it was reading 221 * (ditto, *@err == -EAGAIN) 222 * or when it reads all @depth-1 indirect blocks successfully and finds 223 * the whole chain, all way to the data (returns %NULL, *err == 0). 224 */ 225 static Indirect *ext2_get_branch(struct inode *inode, 226 int depth, 227 int *offsets, 228 Indirect chain[4], 229 int *err) 230 { 231 struct super_block *sb = inode->i_sb; 232 Indirect *p = chain; 233 struct buffer_head *bh; 234 235 *err = 0; 236 /* i_data is not going away, no lock needed */ 237 add_chain (chain, NULL, EXT2_I(inode)->i_data + *offsets); 238 if (!p->key) 239 goto no_block; 240 while (--depth) { 241 bh = sb_bread(sb, le32_to_cpu(p->key)); 242 if (!bh) 243 goto failure; 244 read_lock(&EXT2_I(inode)->i_meta_lock); 245 if (!verify_chain(chain, p)) 246 goto changed; 247 add_chain(++p, bh, (__le32*)bh->b_data + *++offsets); 248 read_unlock(&EXT2_I(inode)->i_meta_lock); 249 if (!p->key) 250 goto no_block; 251 } 252 return NULL; 253 254 changed: 255 read_unlock(&EXT2_I(inode)->i_meta_lock); 256 brelse(bh); 257 *err = -EAGAIN; 258 goto no_block; 259 failure: 260 *err = -EIO; 261 no_block: 262 return p; 263 } 264 265 /** 266 * ext2_find_near - find a place for allocation with sufficient locality 267 * @inode: owner 268 * @ind: descriptor of indirect block. 269 * 270 * This function returns the preferred place for block allocation. 271 * It is used when heuristic for sequential allocation fails. 272 * Rules are: 273 * + if there is a block to the left of our position - allocate near it. 274 * + if pointer will live in indirect block - allocate near that block. 275 * + if pointer will live in inode - allocate in the same cylinder group. 276 * 277 * In the latter case we colour the starting block by the callers PID to 278 * prevent it from clashing with concurrent allocations for a different inode 279 * in the same block group. The PID is used here so that functionally related 280 * files will be close-by on-disk. 281 * 282 * Caller must make sure that @ind is valid and will stay that way. 283 */ 284 285 static ext2_fsblk_t ext2_find_near(struct inode *inode, Indirect *ind) 286 { 287 struct ext2_inode_info *ei = EXT2_I(inode); 288 __le32 *start = ind->bh ? (__le32 *) ind->bh->b_data : ei->i_data; 289 __le32 *p; 290 ext2_fsblk_t bg_start; 291 ext2_fsblk_t colour; 292 293 /* Try to find previous block */ 294 for (p = ind->p - 1; p >= start; p--) 295 if (*p) 296 return le32_to_cpu(*p); 297 298 /* No such thing, so let's try location of indirect block */ 299 if (ind->bh) 300 return ind->bh->b_blocknr; 301 302 /* 303 * It is going to be referred from inode itself? OK, just put it into 304 * the same cylinder group then. 305 */ 306 bg_start = ext2_group_first_block_no(inode->i_sb, ei->i_block_group); 307 colour = (current->pid % 16) * 308 (EXT2_BLOCKS_PER_GROUP(inode->i_sb) / 16); 309 return bg_start + colour; 310 } 311 312 /** 313 * ext2_find_goal - find a preferred place for allocation. 314 * @inode: owner 315 * @block: block we want 316 * @partial: pointer to the last triple within a chain 317 * 318 * Returns preferred place for a block (the goal). 319 */ 320 321 static inline ext2_fsblk_t ext2_find_goal(struct inode *inode, long block, 322 Indirect *partial) 323 { 324 struct ext2_block_alloc_info *block_i; 325 326 block_i = EXT2_I(inode)->i_block_alloc_info; 327 328 /* 329 * try the heuristic for sequential allocation, 330 * failing that at least try to get decent locality. 331 */ 332 if (block_i && (block == block_i->last_alloc_logical_block + 1) 333 && (block_i->last_alloc_physical_block != 0)) { 334 return block_i->last_alloc_physical_block + 1; 335 } 336 337 return ext2_find_near(inode, partial); 338 } 339 340 /** 341 * ext2_blks_to_allocate: Look up the block map and count the number 342 * of direct blocks need to be allocated for the given branch. 343 * 344 * @branch: chain of indirect blocks 345 * @k: number of blocks need for indirect blocks 346 * @blks: number of data blocks to be mapped. 347 * @blocks_to_boundary: the offset in the indirect block 348 * 349 * return the total number of blocks to be allocate, including the 350 * direct and indirect blocks. 351 */ 352 static int 353 ext2_blks_to_allocate(Indirect * branch, int k, unsigned long blks, 354 int blocks_to_boundary) 355 { 356 unsigned long count = 0; 357 358 /* 359 * Simple case, [t,d]Indirect block(s) has not allocated yet 360 * then it's clear blocks on that path have not allocated 361 */ 362 if (k > 0) { 363 /* right now don't hanel cross boundary allocation */ 364 if (blks < blocks_to_boundary + 1) 365 count += blks; 366 else 367 count += blocks_to_boundary + 1; 368 return count; 369 } 370 371 count++; 372 while (count < blks && count <= blocks_to_boundary 373 && le32_to_cpu(*(branch[0].p + count)) == 0) { 374 count++; 375 } 376 return count; 377 } 378 379 /** 380 * ext2_alloc_blocks: multiple allocate blocks needed for a branch 381 * @indirect_blks: the number of blocks need to allocate for indirect 382 * blocks 383 * 384 * @new_blocks: on return it will store the new block numbers for 385 * the indirect blocks(if needed) and the first direct block, 386 * @blks: on return it will store the total number of allocated 387 * direct blocks 388 */ 389 static int ext2_alloc_blocks(struct inode *inode, 390 ext2_fsblk_t goal, int indirect_blks, int blks, 391 ext2_fsblk_t new_blocks[4], int *err) 392 { 393 int target, i; 394 unsigned long count = 0; 395 int index = 0; 396 ext2_fsblk_t current_block = 0; 397 int ret = 0; 398 399 /* 400 * Here we try to allocate the requested multiple blocks at once, 401 * on a best-effort basis. 402 * To build a branch, we should allocate blocks for 403 * the indirect blocks(if not allocated yet), and at least 404 * the first direct block of this branch. That's the 405 * minimum number of blocks need to allocate(required) 406 */ 407 target = blks + indirect_blks; 408 409 while (1) { 410 count = target; 411 /* allocating blocks for indirect blocks and direct blocks */ 412 current_block = ext2_new_blocks(inode,goal,&count,err); 413 if (*err) 414 goto failed_out; 415 416 target -= count; 417 /* allocate blocks for indirect blocks */ 418 while (index < indirect_blks && count) { 419 new_blocks[index++] = current_block++; 420 count--; 421 } 422 423 if (count > 0) 424 break; 425 } 426 427 /* save the new block number for the first direct block */ 428 new_blocks[index] = current_block; 429 430 /* total number of blocks allocated for direct blocks */ 431 ret = count; 432 *err = 0; 433 return ret; 434 failed_out: 435 for (i = 0; i <index; i++) 436 ext2_free_blocks(inode, new_blocks[i], 1); 437 if (index) 438 mark_inode_dirty(inode); 439 return ret; 440 } 441 442 /** 443 * ext2_alloc_branch - allocate and set up a chain of blocks. 444 * @inode: owner 445 * @num: depth of the chain (number of blocks to allocate) 446 * @offsets: offsets (in the blocks) to store the pointers to next. 447 * @branch: place to store the chain in. 448 * 449 * This function allocates @num blocks, zeroes out all but the last one, 450 * links them into chain and (if we are synchronous) writes them to disk. 451 * In other words, it prepares a branch that can be spliced onto the 452 * inode. It stores the information about that chain in the branch[], in 453 * the same format as ext2_get_branch() would do. We are calling it after 454 * we had read the existing part of chain and partial points to the last 455 * triple of that (one with zero ->key). Upon the exit we have the same 456 * picture as after the successful ext2_get_block(), except that in one 457 * place chain is disconnected - *branch->p is still zero (we did not 458 * set the last link), but branch->key contains the number that should 459 * be placed into *branch->p to fill that gap. 460 * 461 * If allocation fails we free all blocks we've allocated (and forget 462 * their buffer_heads) and return the error value the from failed 463 * ext2_alloc_block() (normally -ENOSPC). Otherwise we set the chain 464 * as described above and return 0. 465 */ 466 467 static int ext2_alloc_branch(struct inode *inode, 468 int indirect_blks, int *blks, ext2_fsblk_t goal, 469 int *offsets, Indirect *branch) 470 { 471 int blocksize = inode->i_sb->s_blocksize; 472 int i, n = 0; 473 int err = 0; 474 struct buffer_head *bh; 475 int num; 476 ext2_fsblk_t new_blocks[4]; 477 ext2_fsblk_t current_block; 478 479 num = ext2_alloc_blocks(inode, goal, indirect_blks, 480 *blks, new_blocks, &err); 481 if (err) 482 return err; 483 484 branch[0].key = cpu_to_le32(new_blocks[0]); 485 /* 486 * metadata blocks and data blocks are allocated. 487 */ 488 for (n = 1; n <= indirect_blks; n++) { 489 /* 490 * Get buffer_head for parent block, zero it out 491 * and set the pointer to new one, then send 492 * parent to disk. 493 */ 494 bh = sb_getblk(inode->i_sb, new_blocks[n-1]); 495 branch[n].bh = bh; 496 lock_buffer(bh); 497 memset(bh->b_data, 0, blocksize); 498 branch[n].p = (__le32 *) bh->b_data + offsets[n]; 499 branch[n].key = cpu_to_le32(new_blocks[n]); 500 *branch[n].p = branch[n].key; 501 if ( n == indirect_blks) { 502 current_block = new_blocks[n]; 503 /* 504 * End of chain, update the last new metablock of 505 * the chain to point to the new allocated 506 * data blocks numbers 507 */ 508 for (i=1; i < num; i++) 509 *(branch[n].p + i) = cpu_to_le32(++current_block); 510 } 511 set_buffer_uptodate(bh); 512 unlock_buffer(bh); 513 mark_buffer_dirty_inode(bh, inode); 514 /* We used to sync bh here if IS_SYNC(inode). 515 * But we now rely upon generic_write_sync() 516 * and b_inode_buffers. But not for directories. 517 */ 518 if (S_ISDIR(inode->i_mode) && IS_DIRSYNC(inode)) 519 sync_dirty_buffer(bh); 520 } 521 *blks = num; 522 return err; 523 } 524 525 /** 526 * ext2_splice_branch - splice the allocated branch onto inode. 527 * @inode: owner 528 * @block: (logical) number of block we are adding 529 * @where: location of missing link 530 * @num: number of indirect blocks we are adding 531 * @blks: number of direct blocks we are adding 532 * 533 * This function fills the missing link and does all housekeeping needed in 534 * inode (->i_blocks, etc.). In case of success we end up with the full 535 * chain to new block and return 0. 536 */ 537 static void ext2_splice_branch(struct inode *inode, 538 long block, Indirect *where, int num, int blks) 539 { 540 int i; 541 struct ext2_block_alloc_info *block_i; 542 ext2_fsblk_t current_block; 543 544 block_i = EXT2_I(inode)->i_block_alloc_info; 545 546 /* XXX LOCKING probably should have i_meta_lock ?*/ 547 /* That's it */ 548 549 *where->p = where->key; 550 551 /* 552 * Update the host buffer_head or inode to point to more just allocated 553 * direct blocks blocks 554 */ 555 if (num == 0 && blks > 1) { 556 current_block = le32_to_cpu(where->key) + 1; 557 for (i = 1; i < blks; i++) 558 *(where->p + i ) = cpu_to_le32(current_block++); 559 } 560 561 /* 562 * update the most recently allocated logical & physical block 563 * in i_block_alloc_info, to assist find the proper goal block for next 564 * allocation 565 */ 566 if (block_i) { 567 block_i->last_alloc_logical_block = block + blks - 1; 568 block_i->last_alloc_physical_block = 569 le32_to_cpu(where[num].key) + blks - 1; 570 } 571 572 /* We are done with atomic stuff, now do the rest of housekeeping */ 573 574 /* had we spliced it onto indirect block? */ 575 if (where->bh) 576 mark_buffer_dirty_inode(where->bh, inode); 577 578 inode->i_ctime = CURRENT_TIME_SEC; 579 mark_inode_dirty(inode); 580 } 581 582 /* 583 * Allocation strategy is simple: if we have to allocate something, we will 584 * have to go the whole way to leaf. So let's do it before attaching anything 585 * to tree, set linkage between the newborn blocks, write them if sync is 586 * required, recheck the path, free and repeat if check fails, otherwise 587 * set the last missing link (that will protect us from any truncate-generated 588 * removals - all blocks on the path are immune now) and possibly force the 589 * write on the parent block. 590 * That has a nice additional property: no special recovery from the failed 591 * allocations is needed - we simply release blocks and do not touch anything 592 * reachable from inode. 593 * 594 * `handle' can be NULL if create == 0. 595 * 596 * return > 0, # of blocks mapped or allocated. 597 * return = 0, if plain lookup failed. 598 * return < 0, error case. 599 */ 600 static int ext2_get_blocks(struct inode *inode, 601 sector_t iblock, unsigned long maxblocks, 602 struct buffer_head *bh_result, 603 int create) 604 { 605 int err = -EIO; 606 int offsets[4]; 607 Indirect chain[4]; 608 Indirect *partial; 609 ext2_fsblk_t goal; 610 int indirect_blks; 611 int blocks_to_boundary = 0; 612 int depth; 613 struct ext2_inode_info *ei = EXT2_I(inode); 614 int count = 0; 615 ext2_fsblk_t first_block = 0; 616 617 depth = ext2_block_to_path(inode,iblock,offsets,&blocks_to_boundary); 618 619 if (depth == 0) 620 return (err); 621 622 partial = ext2_get_branch(inode, depth, offsets, chain, &err); 623 /* Simplest case - block found, no allocation needed */ 624 if (!partial) { 625 first_block = le32_to_cpu(chain[depth - 1].key); 626 clear_buffer_new(bh_result); /* What's this do? */ 627 count++; 628 /*map more blocks*/ 629 while (count < maxblocks && count <= blocks_to_boundary) { 630 ext2_fsblk_t blk; 631 632 if (!verify_chain(chain, chain + depth - 1)) { 633 /* 634 * Indirect block might be removed by 635 * truncate while we were reading it. 636 * Handling of that case: forget what we've 637 * got now, go to reread. 638 */ 639 err = -EAGAIN; 640 count = 0; 641 break; 642 } 643 blk = le32_to_cpu(*(chain[depth-1].p + count)); 644 if (blk == first_block + count) 645 count++; 646 else 647 break; 648 } 649 if (err != -EAGAIN) 650 goto got_it; 651 } 652 653 /* Next simple case - plain lookup or failed read of indirect block */ 654 if (!create || err == -EIO) 655 goto cleanup; 656 657 mutex_lock(&ei->truncate_mutex); 658 /* 659 * If the indirect block is missing while we are reading 660 * the chain(ext2_get_branch() returns -EAGAIN err), or 661 * if the chain has been changed after we grab the semaphore, 662 * (either because another process truncated this branch, or 663 * another get_block allocated this branch) re-grab the chain to see if 664 * the request block has been allocated or not. 665 * 666 * Since we already block the truncate/other get_block 667 * at this point, we will have the current copy of the chain when we 668 * splice the branch into the tree. 669 */ 670 if (err == -EAGAIN || !verify_chain(chain, partial)) { 671 while (partial > chain) { 672 brelse(partial->bh); 673 partial--; 674 } 675 partial = ext2_get_branch(inode, depth, offsets, chain, &err); 676 if (!partial) { 677 count++; 678 mutex_unlock(&ei->truncate_mutex); 679 if (err) 680 goto cleanup; 681 clear_buffer_new(bh_result); 682 goto got_it; 683 } 684 } 685 686 /* 687 * Okay, we need to do block allocation. Lazily initialize the block 688 * allocation info here if necessary 689 */ 690 if (S_ISREG(inode->i_mode) && (!ei->i_block_alloc_info)) 691 ext2_init_block_alloc_info(inode); 692 693 goal = ext2_find_goal(inode, iblock, partial); 694 695 /* the number of blocks need to allocate for [d,t]indirect blocks */ 696 indirect_blks = (chain + depth) - partial - 1; 697 /* 698 * Next look up the indirect map to count the totoal number of 699 * direct blocks to allocate for this branch. 700 */ 701 count = ext2_blks_to_allocate(partial, indirect_blks, 702 maxblocks, blocks_to_boundary); 703 /* 704 * XXX ???? Block out ext2_truncate while we alter the tree 705 */ 706 err = ext2_alloc_branch(inode, indirect_blks, &count, goal, 707 offsets + (partial - chain), partial); 708 709 if (err) { 710 mutex_unlock(&ei->truncate_mutex); 711 goto cleanup; 712 } 713 714 if (ext2_use_xip(inode->i_sb)) { 715 /* 716 * we need to clear the block 717 */ 718 err = ext2_clear_xip_target (inode, 719 le32_to_cpu(chain[depth-1].key)); 720 if (err) { 721 mutex_unlock(&ei->truncate_mutex); 722 goto cleanup; 723 } 724 } 725 726 ext2_splice_branch(inode, iblock, partial, indirect_blks, count); 727 mutex_unlock(&ei->truncate_mutex); 728 set_buffer_new(bh_result); 729 got_it: 730 map_bh(bh_result, inode->i_sb, le32_to_cpu(chain[depth-1].key)); 731 if (count > blocks_to_boundary) 732 set_buffer_boundary(bh_result); 733 err = count; 734 /* Clean up and exit */ 735 partial = chain + depth - 1; /* the whole chain */ 736 cleanup: 737 while (partial > chain) { 738 brelse(partial->bh); 739 partial--; 740 } 741 return err; 742 } 743 744 int ext2_get_block(struct inode *inode, sector_t iblock, struct buffer_head *bh_result, int create) 745 { 746 unsigned max_blocks = bh_result->b_size >> inode->i_blkbits; 747 int ret = ext2_get_blocks(inode, iblock, max_blocks, 748 bh_result, create); 749 if (ret > 0) { 750 bh_result->b_size = (ret << inode->i_blkbits); 751 ret = 0; 752 } 753 return ret; 754 755 } 756 757 int ext2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, 758 u64 start, u64 len) 759 { 760 return generic_block_fiemap(inode, fieinfo, start, len, 761 ext2_get_block); 762 } 763 764 static int ext2_writepage(struct page *page, struct writeback_control *wbc) 765 { 766 return block_write_full_page(page, ext2_get_block, wbc); 767 } 768 769 static int ext2_readpage(struct file *file, struct page *page) 770 { 771 return mpage_readpage(page, ext2_get_block); 772 } 773 774 static int 775 ext2_readpages(struct file *file, struct address_space *mapping, 776 struct list_head *pages, unsigned nr_pages) 777 { 778 return mpage_readpages(mapping, pages, nr_pages, ext2_get_block); 779 } 780 781 static int 782 ext2_write_begin(struct file *file, struct address_space *mapping, 783 loff_t pos, unsigned len, unsigned flags, 784 struct page **pagep, void **fsdata) 785 { 786 int ret; 787 788 ret = block_write_begin(mapping, pos, len, flags, pagep, 789 ext2_get_block); 790 if (ret < 0) 791 ext2_write_failed(mapping, pos + len); 792 return ret; 793 } 794 795 static int ext2_write_end(struct file *file, struct address_space *mapping, 796 loff_t pos, unsigned len, unsigned copied, 797 struct page *page, void *fsdata) 798 { 799 int ret; 800 801 ret = generic_write_end(file, mapping, pos, len, copied, page, fsdata); 802 if (ret < len) 803 ext2_write_failed(mapping, pos + len); 804 return ret; 805 } 806 807 static int 808 ext2_nobh_write_begin(struct file *file, struct address_space *mapping, 809 loff_t pos, unsigned len, unsigned flags, 810 struct page **pagep, void **fsdata) 811 { 812 int ret; 813 814 ret = nobh_write_begin(mapping, pos, len, flags, pagep, fsdata, 815 ext2_get_block); 816 if (ret < 0) 817 ext2_write_failed(mapping, pos + len); 818 return ret; 819 } 820 821 static int ext2_nobh_writepage(struct page *page, 822 struct writeback_control *wbc) 823 { 824 return nobh_writepage(page, ext2_get_block, wbc); 825 } 826 827 static sector_t ext2_bmap(struct address_space *mapping, sector_t block) 828 { 829 return generic_block_bmap(mapping,block,ext2_get_block); 830 } 831 832 static ssize_t 833 ext2_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov, 834 loff_t offset, unsigned long nr_segs) 835 { 836 struct file *file = iocb->ki_filp; 837 struct address_space *mapping = file->f_mapping; 838 struct inode *inode = mapping->host; 839 ssize_t ret; 840 841 ret = blockdev_direct_IO(rw, iocb, inode, iov, offset, nr_segs, 842 ext2_get_block); 843 if (ret < 0 && (rw & WRITE)) 844 ext2_write_failed(mapping, offset + iov_length(iov, nr_segs)); 845 return ret; 846 } 847 848 static int 849 ext2_writepages(struct address_space *mapping, struct writeback_control *wbc) 850 { 851 return mpage_writepages(mapping, wbc, ext2_get_block); 852 } 853 854 const struct address_space_operations ext2_aops = { 855 .readpage = ext2_readpage, 856 .readpages = ext2_readpages, 857 .writepage = ext2_writepage, 858 .write_begin = ext2_write_begin, 859 .write_end = ext2_write_end, 860 .bmap = ext2_bmap, 861 .direct_IO = ext2_direct_IO, 862 .writepages = ext2_writepages, 863 .migratepage = buffer_migrate_page, 864 .is_partially_uptodate = block_is_partially_uptodate, 865 .error_remove_page = generic_error_remove_page, 866 }; 867 868 const struct address_space_operations ext2_aops_xip = { 869 .bmap = ext2_bmap, 870 .get_xip_mem = ext2_get_xip_mem, 871 }; 872 873 const struct address_space_operations ext2_nobh_aops = { 874 .readpage = ext2_readpage, 875 .readpages = ext2_readpages, 876 .writepage = ext2_nobh_writepage, 877 .write_begin = ext2_nobh_write_begin, 878 .write_end = nobh_write_end, 879 .bmap = ext2_bmap, 880 .direct_IO = ext2_direct_IO, 881 .writepages = ext2_writepages, 882 .migratepage = buffer_migrate_page, 883 .error_remove_page = generic_error_remove_page, 884 }; 885 886 /* 887 * Probably it should be a library function... search for first non-zero word 888 * or memcmp with zero_page, whatever is better for particular architecture. 889 * Linus? 890 */ 891 static inline int all_zeroes(__le32 *p, __le32 *q) 892 { 893 while (p < q) 894 if (*p++) 895 return 0; 896 return 1; 897 } 898 899 /** 900 * ext2_find_shared - find the indirect blocks for partial truncation. 901 * @inode: inode in question 902 * @depth: depth of the affected branch 903 * @offsets: offsets of pointers in that branch (see ext2_block_to_path) 904 * @chain: place to store the pointers to partial indirect blocks 905 * @top: place to the (detached) top of branch 906 * 907 * This is a helper function used by ext2_truncate(). 908 * 909 * When we do truncate() we may have to clean the ends of several indirect 910 * blocks but leave the blocks themselves alive. Block is partially 911 * truncated if some data below the new i_size is referred from it (and 912 * it is on the path to the first completely truncated data block, indeed). 913 * We have to free the top of that path along with everything to the right 914 * of the path. Since no allocation past the truncation point is possible 915 * until ext2_truncate() finishes, we may safely do the latter, but top 916 * of branch may require special attention - pageout below the truncation 917 * point might try to populate it. 918 * 919 * We atomically detach the top of branch from the tree, store the block 920 * number of its root in *@top, pointers to buffer_heads of partially 921 * truncated blocks - in @chain[].bh and pointers to their last elements 922 * that should not be removed - in @chain[].p. Return value is the pointer 923 * to last filled element of @chain. 924 * 925 * The work left to caller to do the actual freeing of subtrees: 926 * a) free the subtree starting from *@top 927 * b) free the subtrees whose roots are stored in 928 * (@chain[i].p+1 .. end of @chain[i].bh->b_data) 929 * c) free the subtrees growing from the inode past the @chain[0].p 930 * (no partially truncated stuff there). 931 */ 932 933 static Indirect *ext2_find_shared(struct inode *inode, 934 int depth, 935 int offsets[4], 936 Indirect chain[4], 937 __le32 *top) 938 { 939 Indirect *partial, *p; 940 int k, err; 941 942 *top = 0; 943 for (k = depth; k > 1 && !offsets[k-1]; k--) 944 ; 945 partial = ext2_get_branch(inode, k, offsets, chain, &err); 946 if (!partial) 947 partial = chain + k-1; 948 /* 949 * If the branch acquired continuation since we've looked at it - 950 * fine, it should all survive and (new) top doesn't belong to us. 951 */ 952 write_lock(&EXT2_I(inode)->i_meta_lock); 953 if (!partial->key && *partial->p) { 954 write_unlock(&EXT2_I(inode)->i_meta_lock); 955 goto no_top; 956 } 957 for (p=partial; p>chain && all_zeroes((__le32*)p->bh->b_data,p->p); p--) 958 ; 959 /* 960 * OK, we've found the last block that must survive. The rest of our 961 * branch should be detached before unlocking. However, if that rest 962 * of branch is all ours and does not grow immediately from the inode 963 * it's easier to cheat and just decrement partial->p. 964 */ 965 if (p == chain + k - 1 && p > chain) { 966 p->p--; 967 } else { 968 *top = *p->p; 969 *p->p = 0; 970 } 971 write_unlock(&EXT2_I(inode)->i_meta_lock); 972 973 while(partial > p) 974 { 975 brelse(partial->bh); 976 partial--; 977 } 978 no_top: 979 return partial; 980 } 981 982 /** 983 * ext2_free_data - free a list of data blocks 984 * @inode: inode we are dealing with 985 * @p: array of block numbers 986 * @q: points immediately past the end of array 987 * 988 * We are freeing all blocks referred from that array (numbers are 989 * stored as little-endian 32-bit) and updating @inode->i_blocks 990 * appropriately. 991 */ 992 static inline void ext2_free_data(struct inode *inode, __le32 *p, __le32 *q) 993 { 994 unsigned long block_to_free = 0, count = 0; 995 unsigned long nr; 996 997 for ( ; p < q ; p++) { 998 nr = le32_to_cpu(*p); 999 if (nr) { 1000 *p = 0; 1001 /* accumulate blocks to free if they're contiguous */ 1002 if (count == 0) 1003 goto free_this; 1004 else if (block_to_free == nr - count) 1005 count++; 1006 else { 1007 ext2_free_blocks (inode, block_to_free, count); 1008 mark_inode_dirty(inode); 1009 free_this: 1010 block_to_free = nr; 1011 count = 1; 1012 } 1013 } 1014 } 1015 if (count > 0) { 1016 ext2_free_blocks (inode, block_to_free, count); 1017 mark_inode_dirty(inode); 1018 } 1019 } 1020 1021 /** 1022 * ext2_free_branches - free an array of branches 1023 * @inode: inode we are dealing with 1024 * @p: array of block numbers 1025 * @q: pointer immediately past the end of array 1026 * @depth: depth of the branches to free 1027 * 1028 * We are freeing all blocks referred from these branches (numbers are 1029 * stored as little-endian 32-bit) and updating @inode->i_blocks 1030 * appropriately. 1031 */ 1032 static void ext2_free_branches(struct inode *inode, __le32 *p, __le32 *q, int depth) 1033 { 1034 struct buffer_head * bh; 1035 unsigned long nr; 1036 1037 if (depth--) { 1038 int addr_per_block = EXT2_ADDR_PER_BLOCK(inode->i_sb); 1039 for ( ; p < q ; p++) { 1040 nr = le32_to_cpu(*p); 1041 if (!nr) 1042 continue; 1043 *p = 0; 1044 bh = sb_bread(inode->i_sb, nr); 1045 /* 1046 * A read failure? Report error and clear slot 1047 * (should be rare). 1048 */ 1049 if (!bh) { 1050 ext2_error(inode->i_sb, "ext2_free_branches", 1051 "Read failure, inode=%ld, block=%ld", 1052 inode->i_ino, nr); 1053 continue; 1054 } 1055 ext2_free_branches(inode, 1056 (__le32*)bh->b_data, 1057 (__le32*)bh->b_data + addr_per_block, 1058 depth); 1059 bforget(bh); 1060 ext2_free_blocks(inode, nr, 1); 1061 mark_inode_dirty(inode); 1062 } 1063 } else 1064 ext2_free_data(inode, p, q); 1065 } 1066 1067 static void __ext2_truncate_blocks(struct inode *inode, loff_t offset) 1068 { 1069 __le32 *i_data = EXT2_I(inode)->i_data; 1070 struct ext2_inode_info *ei = EXT2_I(inode); 1071 int addr_per_block = EXT2_ADDR_PER_BLOCK(inode->i_sb); 1072 int offsets[4]; 1073 Indirect chain[4]; 1074 Indirect *partial; 1075 __le32 nr = 0; 1076 int n; 1077 long iblock; 1078 unsigned blocksize; 1079 blocksize = inode->i_sb->s_blocksize; 1080 iblock = (offset + blocksize-1) >> EXT2_BLOCK_SIZE_BITS(inode->i_sb); 1081 1082 n = ext2_block_to_path(inode, iblock, offsets, NULL); 1083 if (n == 0) 1084 return; 1085 1086 /* 1087 * From here we block out all ext2_get_block() callers who want to 1088 * modify the block allocation tree. 1089 */ 1090 mutex_lock(&ei->truncate_mutex); 1091 1092 if (n == 1) { 1093 ext2_free_data(inode, i_data+offsets[0], 1094 i_data + EXT2_NDIR_BLOCKS); 1095 goto do_indirects; 1096 } 1097 1098 partial = ext2_find_shared(inode, n, offsets, chain, &nr); 1099 /* Kill the top of shared branch (already detached) */ 1100 if (nr) { 1101 if (partial == chain) 1102 mark_inode_dirty(inode); 1103 else 1104 mark_buffer_dirty_inode(partial->bh, inode); 1105 ext2_free_branches(inode, &nr, &nr+1, (chain+n-1) - partial); 1106 } 1107 /* Clear the ends of indirect blocks on the shared branch */ 1108 while (partial > chain) { 1109 ext2_free_branches(inode, 1110 partial->p + 1, 1111 (__le32*)partial->bh->b_data+addr_per_block, 1112 (chain+n-1) - partial); 1113 mark_buffer_dirty_inode(partial->bh, inode); 1114 brelse (partial->bh); 1115 partial--; 1116 } 1117 do_indirects: 1118 /* Kill the remaining (whole) subtrees */ 1119 switch (offsets[0]) { 1120 default: 1121 nr = i_data[EXT2_IND_BLOCK]; 1122 if (nr) { 1123 i_data[EXT2_IND_BLOCK] = 0; 1124 mark_inode_dirty(inode); 1125 ext2_free_branches(inode, &nr, &nr+1, 1); 1126 } 1127 case EXT2_IND_BLOCK: 1128 nr = i_data[EXT2_DIND_BLOCK]; 1129 if (nr) { 1130 i_data[EXT2_DIND_BLOCK] = 0; 1131 mark_inode_dirty(inode); 1132 ext2_free_branches(inode, &nr, &nr+1, 2); 1133 } 1134 case EXT2_DIND_BLOCK: 1135 nr = i_data[EXT2_TIND_BLOCK]; 1136 if (nr) { 1137 i_data[EXT2_TIND_BLOCK] = 0; 1138 mark_inode_dirty(inode); 1139 ext2_free_branches(inode, &nr, &nr+1, 3); 1140 } 1141 case EXT2_TIND_BLOCK: 1142 ; 1143 } 1144 1145 ext2_discard_reservation(inode); 1146 1147 mutex_unlock(&ei->truncate_mutex); 1148 } 1149 1150 static void ext2_truncate_blocks(struct inode *inode, loff_t offset) 1151 { 1152 /* 1153 * XXX: it seems like a bug here that we don't allow 1154 * IS_APPEND inode to have blocks-past-i_size trimmed off. 1155 * review and fix this. 1156 * 1157 * Also would be nice to be able to handle IO errors and such, 1158 * but that's probably too much to ask. 1159 */ 1160 if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || 1161 S_ISLNK(inode->i_mode))) 1162 return; 1163 if (ext2_inode_is_fast_symlink(inode)) 1164 return; 1165 if (IS_APPEND(inode) || IS_IMMUTABLE(inode)) 1166 return; 1167 __ext2_truncate_blocks(inode, offset); 1168 } 1169 1170 static int ext2_setsize(struct inode *inode, loff_t newsize) 1171 { 1172 int error; 1173 1174 if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || 1175 S_ISLNK(inode->i_mode))) 1176 return -EINVAL; 1177 if (ext2_inode_is_fast_symlink(inode)) 1178 return -EINVAL; 1179 if (IS_APPEND(inode) || IS_IMMUTABLE(inode)) 1180 return -EPERM; 1181 1182 inode_dio_wait(inode); 1183 1184 if (mapping_is_xip(inode->i_mapping)) 1185 error = xip_truncate_page(inode->i_mapping, newsize); 1186 else if (test_opt(inode->i_sb, NOBH)) 1187 error = nobh_truncate_page(inode->i_mapping, 1188 newsize, ext2_get_block); 1189 else 1190 error = block_truncate_page(inode->i_mapping, 1191 newsize, ext2_get_block); 1192 if (error) 1193 return error; 1194 1195 truncate_setsize(inode, newsize); 1196 __ext2_truncate_blocks(inode, newsize); 1197 1198 inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC; 1199 if (inode_needs_sync(inode)) { 1200 sync_mapping_buffers(inode->i_mapping); 1201 sync_inode_metadata(inode, 1); 1202 } else { 1203 mark_inode_dirty(inode); 1204 } 1205 1206 return 0; 1207 } 1208 1209 static struct ext2_inode *ext2_get_inode(struct super_block *sb, ino_t ino, 1210 struct buffer_head **p) 1211 { 1212 struct buffer_head * bh; 1213 unsigned long block_group; 1214 unsigned long block; 1215 unsigned long offset; 1216 struct ext2_group_desc * gdp; 1217 1218 *p = NULL; 1219 if ((ino != EXT2_ROOT_INO && ino < EXT2_FIRST_INO(sb)) || 1220 ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count)) 1221 goto Einval; 1222 1223 block_group = (ino - 1) / EXT2_INODES_PER_GROUP(sb); 1224 gdp = ext2_get_group_desc(sb, block_group, NULL); 1225 if (!gdp) 1226 goto Egdp; 1227 /* 1228 * Figure out the offset within the block group inode table 1229 */ 1230 offset = ((ino - 1) % EXT2_INODES_PER_GROUP(sb)) * EXT2_INODE_SIZE(sb); 1231 block = le32_to_cpu(gdp->bg_inode_table) + 1232 (offset >> EXT2_BLOCK_SIZE_BITS(sb)); 1233 if (!(bh = sb_bread(sb, block))) 1234 goto Eio; 1235 1236 *p = bh; 1237 offset &= (EXT2_BLOCK_SIZE(sb) - 1); 1238 return (struct ext2_inode *) (bh->b_data + offset); 1239 1240 Einval: 1241 ext2_error(sb, "ext2_get_inode", "bad inode number: %lu", 1242 (unsigned long) ino); 1243 return ERR_PTR(-EINVAL); 1244 Eio: 1245 ext2_error(sb, "ext2_get_inode", 1246 "unable to read inode block - inode=%lu, block=%lu", 1247 (unsigned long) ino, block); 1248 Egdp: 1249 return ERR_PTR(-EIO); 1250 } 1251 1252 void ext2_set_inode_flags(struct inode *inode) 1253 { 1254 unsigned int flags = EXT2_I(inode)->i_flags; 1255 1256 inode->i_flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC); 1257 if (flags & EXT2_SYNC_FL) 1258 inode->i_flags |= S_SYNC; 1259 if (flags & EXT2_APPEND_FL) 1260 inode->i_flags |= S_APPEND; 1261 if (flags & EXT2_IMMUTABLE_FL) 1262 inode->i_flags |= S_IMMUTABLE; 1263 if (flags & EXT2_NOATIME_FL) 1264 inode->i_flags |= S_NOATIME; 1265 if (flags & EXT2_DIRSYNC_FL) 1266 inode->i_flags |= S_DIRSYNC; 1267 } 1268 1269 /* Propagate flags from i_flags to EXT2_I(inode)->i_flags */ 1270 void ext2_get_inode_flags(struct ext2_inode_info *ei) 1271 { 1272 unsigned int flags = ei->vfs_inode.i_flags; 1273 1274 ei->i_flags &= ~(EXT2_SYNC_FL|EXT2_APPEND_FL| 1275 EXT2_IMMUTABLE_FL|EXT2_NOATIME_FL|EXT2_DIRSYNC_FL); 1276 if (flags & S_SYNC) 1277 ei->i_flags |= EXT2_SYNC_FL; 1278 if (flags & S_APPEND) 1279 ei->i_flags |= EXT2_APPEND_FL; 1280 if (flags & S_IMMUTABLE) 1281 ei->i_flags |= EXT2_IMMUTABLE_FL; 1282 if (flags & S_NOATIME) 1283 ei->i_flags |= EXT2_NOATIME_FL; 1284 if (flags & S_DIRSYNC) 1285 ei->i_flags |= EXT2_DIRSYNC_FL; 1286 } 1287 1288 struct inode *ext2_iget (struct super_block *sb, unsigned long ino) 1289 { 1290 struct ext2_inode_info *ei; 1291 struct buffer_head * bh; 1292 struct ext2_inode *raw_inode; 1293 struct inode *inode; 1294 long ret = -EIO; 1295 int n; 1296 uid_t i_uid; 1297 gid_t i_gid; 1298 1299 inode = iget_locked(sb, ino); 1300 if (!inode) 1301 return ERR_PTR(-ENOMEM); 1302 if (!(inode->i_state & I_NEW)) 1303 return inode; 1304 1305 ei = EXT2_I(inode); 1306 ei->i_block_alloc_info = NULL; 1307 1308 raw_inode = ext2_get_inode(inode->i_sb, ino, &bh); 1309 if (IS_ERR(raw_inode)) { 1310 ret = PTR_ERR(raw_inode); 1311 goto bad_inode; 1312 } 1313 1314 inode->i_mode = le16_to_cpu(raw_inode->i_mode); 1315 i_uid = (uid_t)le16_to_cpu(raw_inode->i_uid_low); 1316 i_gid = (gid_t)le16_to_cpu(raw_inode->i_gid_low); 1317 if (!(test_opt (inode->i_sb, NO_UID32))) { 1318 i_uid |= le16_to_cpu(raw_inode->i_uid_high) << 16; 1319 i_gid |= le16_to_cpu(raw_inode->i_gid_high) << 16; 1320 } 1321 i_uid_write(inode, i_uid); 1322 i_gid_write(inode, i_gid); 1323 set_nlink(inode, le16_to_cpu(raw_inode->i_links_count)); 1324 inode->i_size = le32_to_cpu(raw_inode->i_size); 1325 inode->i_atime.tv_sec = (signed)le32_to_cpu(raw_inode->i_atime); 1326 inode->i_ctime.tv_sec = (signed)le32_to_cpu(raw_inode->i_ctime); 1327 inode->i_mtime.tv_sec = (signed)le32_to_cpu(raw_inode->i_mtime); 1328 inode->i_atime.tv_nsec = inode->i_mtime.tv_nsec = inode->i_ctime.tv_nsec = 0; 1329 ei->i_dtime = le32_to_cpu(raw_inode->i_dtime); 1330 /* We now have enough fields to check if the inode was active or not. 1331 * This is needed because nfsd might try to access dead inodes 1332 * the test is that same one that e2fsck uses 1333 * NeilBrown 1999oct15 1334 */ 1335 if (inode->i_nlink == 0 && (inode->i_mode == 0 || ei->i_dtime)) { 1336 /* this inode is deleted */ 1337 brelse (bh); 1338 ret = -ESTALE; 1339 goto bad_inode; 1340 } 1341 inode->i_blocks = le32_to_cpu(raw_inode->i_blocks); 1342 ei->i_flags = le32_to_cpu(raw_inode->i_flags); 1343 ei->i_faddr = le32_to_cpu(raw_inode->i_faddr); 1344 ei->i_frag_no = raw_inode->i_frag; 1345 ei->i_frag_size = raw_inode->i_fsize; 1346 ei->i_file_acl = le32_to_cpu(raw_inode->i_file_acl); 1347 ei->i_dir_acl = 0; 1348 if (S_ISREG(inode->i_mode)) 1349 inode->i_size |= ((__u64)le32_to_cpu(raw_inode->i_size_high)) << 32; 1350 else 1351 ei->i_dir_acl = le32_to_cpu(raw_inode->i_dir_acl); 1352 ei->i_dtime = 0; 1353 inode->i_generation = le32_to_cpu(raw_inode->i_generation); 1354 ei->i_state = 0; 1355 ei->i_block_group = (ino - 1) / EXT2_INODES_PER_GROUP(inode->i_sb); 1356 ei->i_dir_start_lookup = 0; 1357 1358 /* 1359 * NOTE! The in-memory inode i_data array is in little-endian order 1360 * even on big-endian machines: we do NOT byteswap the block numbers! 1361 */ 1362 for (n = 0; n < EXT2_N_BLOCKS; n++) 1363 ei->i_data[n] = raw_inode->i_block[n]; 1364 1365 if (S_ISREG(inode->i_mode)) { 1366 inode->i_op = &ext2_file_inode_operations; 1367 if (ext2_use_xip(inode->i_sb)) { 1368 inode->i_mapping->a_ops = &ext2_aops_xip; 1369 inode->i_fop = &ext2_xip_file_operations; 1370 } else if (test_opt(inode->i_sb, NOBH)) { 1371 inode->i_mapping->a_ops = &ext2_nobh_aops; 1372 inode->i_fop = &ext2_file_operations; 1373 } else { 1374 inode->i_mapping->a_ops = &ext2_aops; 1375 inode->i_fop = &ext2_file_operations; 1376 } 1377 } else if (S_ISDIR(inode->i_mode)) { 1378 inode->i_op = &ext2_dir_inode_operations; 1379 inode->i_fop = &ext2_dir_operations; 1380 if (test_opt(inode->i_sb, NOBH)) 1381 inode->i_mapping->a_ops = &ext2_nobh_aops; 1382 else 1383 inode->i_mapping->a_ops = &ext2_aops; 1384 } else if (S_ISLNK(inode->i_mode)) { 1385 if (ext2_inode_is_fast_symlink(inode)) { 1386 inode->i_op = &ext2_fast_symlink_inode_operations; 1387 nd_terminate_link(ei->i_data, inode->i_size, 1388 sizeof(ei->i_data) - 1); 1389 } else { 1390 inode->i_op = &ext2_symlink_inode_operations; 1391 if (test_opt(inode->i_sb, NOBH)) 1392 inode->i_mapping->a_ops = &ext2_nobh_aops; 1393 else 1394 inode->i_mapping->a_ops = &ext2_aops; 1395 } 1396 } else { 1397 inode->i_op = &ext2_special_inode_operations; 1398 if (raw_inode->i_block[0]) 1399 init_special_inode(inode, inode->i_mode, 1400 old_decode_dev(le32_to_cpu(raw_inode->i_block[0]))); 1401 else 1402 init_special_inode(inode, inode->i_mode, 1403 new_decode_dev(le32_to_cpu(raw_inode->i_block[1]))); 1404 } 1405 brelse (bh); 1406 ext2_set_inode_flags(inode); 1407 unlock_new_inode(inode); 1408 return inode; 1409 1410 bad_inode: 1411 iget_failed(inode); 1412 return ERR_PTR(ret); 1413 } 1414 1415 static int __ext2_write_inode(struct inode *inode, int do_sync) 1416 { 1417 struct ext2_inode_info *ei = EXT2_I(inode); 1418 struct super_block *sb = inode->i_sb; 1419 ino_t ino = inode->i_ino; 1420 uid_t uid = i_uid_read(inode); 1421 gid_t gid = i_gid_read(inode); 1422 struct buffer_head * bh; 1423 struct ext2_inode * raw_inode = ext2_get_inode(sb, ino, &bh); 1424 int n; 1425 int err = 0; 1426 1427 if (IS_ERR(raw_inode)) 1428 return -EIO; 1429 1430 /* For fields not not tracking in the in-memory inode, 1431 * initialise them to zero for new inodes. */ 1432 if (ei->i_state & EXT2_STATE_NEW) 1433 memset(raw_inode, 0, EXT2_SB(sb)->s_inode_size); 1434 1435 ext2_get_inode_flags(ei); 1436 raw_inode->i_mode = cpu_to_le16(inode->i_mode); 1437 if (!(test_opt(sb, NO_UID32))) { 1438 raw_inode->i_uid_low = cpu_to_le16(low_16_bits(uid)); 1439 raw_inode->i_gid_low = cpu_to_le16(low_16_bits(gid)); 1440 /* 1441 * Fix up interoperability with old kernels. Otherwise, old inodes get 1442 * re-used with the upper 16 bits of the uid/gid intact 1443 */ 1444 if (!ei->i_dtime) { 1445 raw_inode->i_uid_high = cpu_to_le16(high_16_bits(uid)); 1446 raw_inode->i_gid_high = cpu_to_le16(high_16_bits(gid)); 1447 } else { 1448 raw_inode->i_uid_high = 0; 1449 raw_inode->i_gid_high = 0; 1450 } 1451 } else { 1452 raw_inode->i_uid_low = cpu_to_le16(fs_high2lowuid(uid)); 1453 raw_inode->i_gid_low = cpu_to_le16(fs_high2lowgid(gid)); 1454 raw_inode->i_uid_high = 0; 1455 raw_inode->i_gid_high = 0; 1456 } 1457 raw_inode->i_links_count = cpu_to_le16(inode->i_nlink); 1458 raw_inode->i_size = cpu_to_le32(inode->i_size); 1459 raw_inode->i_atime = cpu_to_le32(inode->i_atime.tv_sec); 1460 raw_inode->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec); 1461 raw_inode->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec); 1462 1463 raw_inode->i_blocks = cpu_to_le32(inode->i_blocks); 1464 raw_inode->i_dtime = cpu_to_le32(ei->i_dtime); 1465 raw_inode->i_flags = cpu_to_le32(ei->i_flags); 1466 raw_inode->i_faddr = cpu_to_le32(ei->i_faddr); 1467 raw_inode->i_frag = ei->i_frag_no; 1468 raw_inode->i_fsize = ei->i_frag_size; 1469 raw_inode->i_file_acl = cpu_to_le32(ei->i_file_acl); 1470 if (!S_ISREG(inode->i_mode)) 1471 raw_inode->i_dir_acl = cpu_to_le32(ei->i_dir_acl); 1472 else { 1473 raw_inode->i_size_high = cpu_to_le32(inode->i_size >> 32); 1474 if (inode->i_size > 0x7fffffffULL) { 1475 if (!EXT2_HAS_RO_COMPAT_FEATURE(sb, 1476 EXT2_FEATURE_RO_COMPAT_LARGE_FILE) || 1477 EXT2_SB(sb)->s_es->s_rev_level == 1478 cpu_to_le32(EXT2_GOOD_OLD_REV)) { 1479 /* If this is the first large file 1480 * created, add a flag to the superblock. 1481 */ 1482 spin_lock(&EXT2_SB(sb)->s_lock); 1483 ext2_update_dynamic_rev(sb); 1484 EXT2_SET_RO_COMPAT_FEATURE(sb, 1485 EXT2_FEATURE_RO_COMPAT_LARGE_FILE); 1486 spin_unlock(&EXT2_SB(sb)->s_lock); 1487 ext2_write_super(sb); 1488 } 1489 } 1490 } 1491 1492 raw_inode->i_generation = cpu_to_le32(inode->i_generation); 1493 if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) { 1494 if (old_valid_dev(inode->i_rdev)) { 1495 raw_inode->i_block[0] = 1496 cpu_to_le32(old_encode_dev(inode->i_rdev)); 1497 raw_inode->i_block[1] = 0; 1498 } else { 1499 raw_inode->i_block[0] = 0; 1500 raw_inode->i_block[1] = 1501 cpu_to_le32(new_encode_dev(inode->i_rdev)); 1502 raw_inode->i_block[2] = 0; 1503 } 1504 } else for (n = 0; n < EXT2_N_BLOCKS; n++) 1505 raw_inode->i_block[n] = ei->i_data[n]; 1506 mark_buffer_dirty(bh); 1507 if (do_sync) { 1508 sync_dirty_buffer(bh); 1509 if (buffer_req(bh) && !buffer_uptodate(bh)) { 1510 printk ("IO error syncing ext2 inode [%s:%08lx]\n", 1511 sb->s_id, (unsigned long) ino); 1512 err = -EIO; 1513 } 1514 } 1515 ei->i_state &= ~EXT2_STATE_NEW; 1516 brelse (bh); 1517 return err; 1518 } 1519 1520 int ext2_write_inode(struct inode *inode, struct writeback_control *wbc) 1521 { 1522 return __ext2_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL); 1523 } 1524 1525 int ext2_setattr(struct dentry *dentry, struct iattr *iattr) 1526 { 1527 struct inode *inode = dentry->d_inode; 1528 int error; 1529 1530 error = inode_change_ok(inode, iattr); 1531 if (error) 1532 return error; 1533 1534 if (is_quota_modification(inode, iattr)) 1535 dquot_initialize(inode); 1536 if ((iattr->ia_valid & ATTR_UID && !uid_eq(iattr->ia_uid, inode->i_uid)) || 1537 (iattr->ia_valid & ATTR_GID && !gid_eq(iattr->ia_gid, inode->i_gid))) { 1538 error = dquot_transfer(inode, iattr); 1539 if (error) 1540 return error; 1541 } 1542 if (iattr->ia_valid & ATTR_SIZE && iattr->ia_size != inode->i_size) { 1543 error = ext2_setsize(inode, iattr->ia_size); 1544 if (error) 1545 return error; 1546 } 1547 setattr_copy(inode, iattr); 1548 if (iattr->ia_valid & ATTR_MODE) 1549 error = ext2_acl_chmod(inode); 1550 mark_inode_dirty(inode); 1551 1552 return error; 1553 } 1554