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/module.h> 30 #include <linux/writeback.h> 31 #include <linux/buffer_head.h> 32 #include <linux/mpage.h> 33 #include <linux/fiemap.h> 34 #include <linux/namei.h> 35 #include "ext2.h" 36 #include "acl.h" 37 #include "xip.h" 38 39 MODULE_AUTHOR("Remy Card and others"); 40 MODULE_DESCRIPTION("Second Extended Filesystem"); 41 MODULE_LICENSE("GPL"); 42 43 static int __ext2_write_inode(struct inode *inode, int do_sync); 44 45 /* 46 * Test whether an inode is a fast symlink. 47 */ 48 static inline int ext2_inode_is_fast_symlink(struct inode *inode) 49 { 50 int ea_blocks = EXT2_I(inode)->i_file_acl ? 51 (inode->i_sb->s_blocksize >> 9) : 0; 52 53 return (S_ISLNK(inode->i_mode) && 54 inode->i_blocks - ea_blocks == 0); 55 } 56 57 static void ext2_truncate_blocks(struct inode *inode, loff_t offset); 58 59 static void ext2_write_failed(struct address_space *mapping, loff_t to) 60 { 61 struct inode *inode = mapping->host; 62 63 if (to > inode->i_size) { 64 truncate_pagecache(inode, to, inode->i_size); 65 ext2_truncate_blocks(inode, inode->i_size); 66 } 67 } 68 69 /* 70 * Called at the last iput() if i_nlink is zero. 71 */ 72 void ext2_delete_inode (struct inode * inode) 73 { 74 if (!is_bad_inode(inode)) 75 dquot_initialize(inode); 76 truncate_inode_pages(&inode->i_data, 0); 77 78 if (is_bad_inode(inode)) 79 goto no_delete; 80 EXT2_I(inode)->i_dtime = get_seconds(); 81 mark_inode_dirty(inode); 82 __ext2_write_inode(inode, inode_needs_sync(inode)); 83 84 inode->i_size = 0; 85 if (inode->i_blocks) 86 ext2_truncate_blocks(inode, 0); 87 ext2_free_inode (inode); 88 89 return; 90 no_delete: 91 clear_inode(inode); /* We must guarantee clearing of inode... */ 92 } 93 94 typedef struct { 95 __le32 *p; 96 __le32 key; 97 struct buffer_head *bh; 98 } Indirect; 99 100 static inline void add_chain(Indirect *p, struct buffer_head *bh, __le32 *v) 101 { 102 p->key = *(p->p = v); 103 p->bh = bh; 104 } 105 106 static inline int verify_chain(Indirect *from, Indirect *to) 107 { 108 while (from <= to && from->key == *from->p) 109 from++; 110 return (from > to); 111 } 112 113 /** 114 * ext2_block_to_path - parse the block number into array of offsets 115 * @inode: inode in question (we are only interested in its superblock) 116 * @i_block: block number to be parsed 117 * @offsets: array to store the offsets in 118 * @boundary: set this non-zero if the referred-to block is likely to be 119 * followed (on disk) by an indirect block. 120 * To store the locations of file's data ext2 uses a data structure common 121 * for UNIX filesystems - tree of pointers anchored in the inode, with 122 * data blocks at leaves and indirect blocks in intermediate nodes. 123 * This function translates the block number into path in that tree - 124 * return value is the path length and @offsets[n] is the offset of 125 * pointer to (n+1)th node in the nth one. If @block is out of range 126 * (negative or too large) warning is printed and zero returned. 127 * 128 * Note: function doesn't find node addresses, so no IO is needed. All 129 * we need to know is the capacity of indirect blocks (taken from the 130 * inode->i_sb). 131 */ 132 133 /* 134 * Portability note: the last comparison (check that we fit into triple 135 * indirect block) is spelled differently, because otherwise on an 136 * architecture with 32-bit longs and 8Kb pages we might get into trouble 137 * if our filesystem had 8Kb blocks. We might use long long, but that would 138 * kill us on x86. Oh, well, at least the sign propagation does not matter - 139 * i_block would have to be negative in the very beginning, so we would not 140 * get there at all. 141 */ 142 143 static int ext2_block_to_path(struct inode *inode, 144 long i_block, int offsets[4], int *boundary) 145 { 146 int ptrs = EXT2_ADDR_PER_BLOCK(inode->i_sb); 147 int ptrs_bits = EXT2_ADDR_PER_BLOCK_BITS(inode->i_sb); 148 const long direct_blocks = EXT2_NDIR_BLOCKS, 149 indirect_blocks = ptrs, 150 double_blocks = (1 << (ptrs_bits * 2)); 151 int n = 0; 152 int final = 0; 153 154 if (i_block < 0) { 155 ext2_msg(inode->i_sb, KERN_WARNING, 156 "warning: %s: block < 0", __func__); 157 } else if (i_block < direct_blocks) { 158 offsets[n++] = i_block; 159 final = direct_blocks; 160 } else if ( (i_block -= direct_blocks) < indirect_blocks) { 161 offsets[n++] = EXT2_IND_BLOCK; 162 offsets[n++] = i_block; 163 final = ptrs; 164 } else if ((i_block -= indirect_blocks) < double_blocks) { 165 offsets[n++] = EXT2_DIND_BLOCK; 166 offsets[n++] = i_block >> ptrs_bits; 167 offsets[n++] = i_block & (ptrs - 1); 168 final = ptrs; 169 } else if (((i_block -= double_blocks) >> (ptrs_bits * 2)) < ptrs) { 170 offsets[n++] = EXT2_TIND_BLOCK; 171 offsets[n++] = i_block >> (ptrs_bits * 2); 172 offsets[n++] = (i_block >> ptrs_bits) & (ptrs - 1); 173 offsets[n++] = i_block & (ptrs - 1); 174 final = ptrs; 175 } else { 176 ext2_msg(inode->i_sb, KERN_WARNING, 177 "warning: %s: block is too big", __func__); 178 } 179 if (boundary) 180 *boundary = final - 1 - (i_block & (ptrs - 1)); 181 182 return n; 183 } 184 185 /** 186 * ext2_get_branch - read the chain of indirect blocks leading to data 187 * @inode: inode in question 188 * @depth: depth of the chain (1 - direct pointer, etc.) 189 * @offsets: offsets of pointers in inode/indirect blocks 190 * @chain: place to store the result 191 * @err: here we store the error value 192 * 193 * Function fills the array of triples <key, p, bh> and returns %NULL 194 * if everything went OK or the pointer to the last filled triple 195 * (incomplete one) otherwise. Upon the return chain[i].key contains 196 * the number of (i+1)-th block in the chain (as it is stored in memory, 197 * i.e. little-endian 32-bit), chain[i].p contains the address of that 198 * number (it points into struct inode for i==0 and into the bh->b_data 199 * for i>0) and chain[i].bh points to the buffer_head of i-th indirect 200 * block for i>0 and NULL for i==0. In other words, it holds the block 201 * numbers of the chain, addresses they were taken from (and where we can 202 * verify that chain did not change) and buffer_heads hosting these 203 * numbers. 204 * 205 * Function stops when it stumbles upon zero pointer (absent block) 206 * (pointer to last triple returned, *@err == 0) 207 * or when it gets an IO error reading an indirect block 208 * (ditto, *@err == -EIO) 209 * or when it notices that chain had been changed while it was reading 210 * (ditto, *@err == -EAGAIN) 211 * or when it reads all @depth-1 indirect blocks successfully and finds 212 * the whole chain, all way to the data (returns %NULL, *err == 0). 213 */ 214 static Indirect *ext2_get_branch(struct inode *inode, 215 int depth, 216 int *offsets, 217 Indirect chain[4], 218 int *err) 219 { 220 struct super_block *sb = inode->i_sb; 221 Indirect *p = chain; 222 struct buffer_head *bh; 223 224 *err = 0; 225 /* i_data is not going away, no lock needed */ 226 add_chain (chain, NULL, EXT2_I(inode)->i_data + *offsets); 227 if (!p->key) 228 goto no_block; 229 while (--depth) { 230 bh = sb_bread(sb, le32_to_cpu(p->key)); 231 if (!bh) 232 goto failure; 233 read_lock(&EXT2_I(inode)->i_meta_lock); 234 if (!verify_chain(chain, p)) 235 goto changed; 236 add_chain(++p, bh, (__le32*)bh->b_data + *++offsets); 237 read_unlock(&EXT2_I(inode)->i_meta_lock); 238 if (!p->key) 239 goto no_block; 240 } 241 return NULL; 242 243 changed: 244 read_unlock(&EXT2_I(inode)->i_meta_lock); 245 brelse(bh); 246 *err = -EAGAIN; 247 goto no_block; 248 failure: 249 *err = -EIO; 250 no_block: 251 return p; 252 } 253 254 /** 255 * ext2_find_near - find a place for allocation with sufficient locality 256 * @inode: owner 257 * @ind: descriptor of indirect block. 258 * 259 * This function returns the preferred place for block allocation. 260 * It is used when heuristic for sequential allocation fails. 261 * Rules are: 262 * + if there is a block to the left of our position - allocate near it. 263 * + if pointer will live in indirect block - allocate near that block. 264 * + if pointer will live in inode - allocate in the same cylinder group. 265 * 266 * In the latter case we colour the starting block by the callers PID to 267 * prevent it from clashing with concurrent allocations for a different inode 268 * in the same block group. The PID is used here so that functionally related 269 * files will be close-by on-disk. 270 * 271 * Caller must make sure that @ind is valid and will stay that way. 272 */ 273 274 static ext2_fsblk_t ext2_find_near(struct inode *inode, Indirect *ind) 275 { 276 struct ext2_inode_info *ei = EXT2_I(inode); 277 __le32 *start = ind->bh ? (__le32 *) ind->bh->b_data : ei->i_data; 278 __le32 *p; 279 ext2_fsblk_t bg_start; 280 ext2_fsblk_t colour; 281 282 /* Try to find previous block */ 283 for (p = ind->p - 1; p >= start; p--) 284 if (*p) 285 return le32_to_cpu(*p); 286 287 /* No such thing, so let's try location of indirect block */ 288 if (ind->bh) 289 return ind->bh->b_blocknr; 290 291 /* 292 * It is going to be refered from inode itself? OK, just put it into 293 * the same cylinder group then. 294 */ 295 bg_start = ext2_group_first_block_no(inode->i_sb, ei->i_block_group); 296 colour = (current->pid % 16) * 297 (EXT2_BLOCKS_PER_GROUP(inode->i_sb) / 16); 298 return bg_start + colour; 299 } 300 301 /** 302 * ext2_find_goal - find a preferred place for allocation. 303 * @inode: owner 304 * @block: block we want 305 * @partial: pointer to the last triple within a chain 306 * 307 * Returns preferred place for a block (the goal). 308 */ 309 310 static inline ext2_fsblk_t ext2_find_goal(struct inode *inode, long block, 311 Indirect *partial) 312 { 313 struct ext2_block_alloc_info *block_i; 314 315 block_i = EXT2_I(inode)->i_block_alloc_info; 316 317 /* 318 * try the heuristic for sequential allocation, 319 * failing that at least try to get decent locality. 320 */ 321 if (block_i && (block == block_i->last_alloc_logical_block + 1) 322 && (block_i->last_alloc_physical_block != 0)) { 323 return block_i->last_alloc_physical_block + 1; 324 } 325 326 return ext2_find_near(inode, partial); 327 } 328 329 /** 330 * ext2_blks_to_allocate: Look up the block map and count the number 331 * of direct blocks need to be allocated for the given branch. 332 * 333 * @branch: chain of indirect blocks 334 * @k: number of blocks need for indirect blocks 335 * @blks: number of data blocks to be mapped. 336 * @blocks_to_boundary: the offset in the indirect block 337 * 338 * return the total number of blocks to be allocate, including the 339 * direct and indirect blocks. 340 */ 341 static int 342 ext2_blks_to_allocate(Indirect * branch, int k, unsigned long blks, 343 int blocks_to_boundary) 344 { 345 unsigned long count = 0; 346 347 /* 348 * Simple case, [t,d]Indirect block(s) has not allocated yet 349 * then it's clear blocks on that path have not allocated 350 */ 351 if (k > 0) { 352 /* right now don't hanel cross boundary allocation */ 353 if (blks < blocks_to_boundary + 1) 354 count += blks; 355 else 356 count += blocks_to_boundary + 1; 357 return count; 358 } 359 360 count++; 361 while (count < blks && count <= blocks_to_boundary 362 && le32_to_cpu(*(branch[0].p + count)) == 0) { 363 count++; 364 } 365 return count; 366 } 367 368 /** 369 * ext2_alloc_blocks: multiple allocate blocks needed for a branch 370 * @indirect_blks: the number of blocks need to allocate for indirect 371 * blocks 372 * 373 * @new_blocks: on return it will store the new block numbers for 374 * the indirect blocks(if needed) and the first direct block, 375 * @blks: on return it will store the total number of allocated 376 * direct blocks 377 */ 378 static int ext2_alloc_blocks(struct inode *inode, 379 ext2_fsblk_t goal, int indirect_blks, int blks, 380 ext2_fsblk_t new_blocks[4], int *err) 381 { 382 int target, i; 383 unsigned long count = 0; 384 int index = 0; 385 ext2_fsblk_t current_block = 0; 386 int ret = 0; 387 388 /* 389 * Here we try to allocate the requested multiple blocks at once, 390 * on a best-effort basis. 391 * To build a branch, we should allocate blocks for 392 * the indirect blocks(if not allocated yet), and at least 393 * the first direct block of this branch. That's the 394 * minimum number of blocks need to allocate(required) 395 */ 396 target = blks + indirect_blks; 397 398 while (1) { 399 count = target; 400 /* allocating blocks for indirect blocks and direct blocks */ 401 current_block = ext2_new_blocks(inode,goal,&count,err); 402 if (*err) 403 goto failed_out; 404 405 target -= count; 406 /* allocate blocks for indirect blocks */ 407 while (index < indirect_blks && count) { 408 new_blocks[index++] = current_block++; 409 count--; 410 } 411 412 if (count > 0) 413 break; 414 } 415 416 /* save the new block number for the first direct block */ 417 new_blocks[index] = current_block; 418 419 /* total number of blocks allocated for direct blocks */ 420 ret = count; 421 *err = 0; 422 return ret; 423 failed_out: 424 for (i = 0; i <index; i++) 425 ext2_free_blocks(inode, new_blocks[i], 1); 426 return ret; 427 } 428 429 /** 430 * ext2_alloc_branch - allocate and set up a chain of blocks. 431 * @inode: owner 432 * @num: depth of the chain (number of blocks to allocate) 433 * @offsets: offsets (in the blocks) to store the pointers to next. 434 * @branch: place to store the chain in. 435 * 436 * This function allocates @num blocks, zeroes out all but the last one, 437 * links them into chain and (if we are synchronous) writes them to disk. 438 * In other words, it prepares a branch that can be spliced onto the 439 * inode. It stores the information about that chain in the branch[], in 440 * the same format as ext2_get_branch() would do. We are calling it after 441 * we had read the existing part of chain and partial points to the last 442 * triple of that (one with zero ->key). Upon the exit we have the same 443 * picture as after the successful ext2_get_block(), excpet that in one 444 * place chain is disconnected - *branch->p is still zero (we did not 445 * set the last link), but branch->key contains the number that should 446 * be placed into *branch->p to fill that gap. 447 * 448 * If allocation fails we free all blocks we've allocated (and forget 449 * their buffer_heads) and return the error value the from failed 450 * ext2_alloc_block() (normally -ENOSPC). Otherwise we set the chain 451 * as described above and return 0. 452 */ 453 454 static int ext2_alloc_branch(struct inode *inode, 455 int indirect_blks, int *blks, ext2_fsblk_t goal, 456 int *offsets, Indirect *branch) 457 { 458 int blocksize = inode->i_sb->s_blocksize; 459 int i, n = 0; 460 int err = 0; 461 struct buffer_head *bh; 462 int num; 463 ext2_fsblk_t new_blocks[4]; 464 ext2_fsblk_t current_block; 465 466 num = ext2_alloc_blocks(inode, goal, indirect_blks, 467 *blks, new_blocks, &err); 468 if (err) 469 return err; 470 471 branch[0].key = cpu_to_le32(new_blocks[0]); 472 /* 473 * metadata blocks and data blocks are allocated. 474 */ 475 for (n = 1; n <= indirect_blks; n++) { 476 /* 477 * Get buffer_head for parent block, zero it out 478 * and set the pointer to new one, then send 479 * parent to disk. 480 */ 481 bh = sb_getblk(inode->i_sb, new_blocks[n-1]); 482 branch[n].bh = bh; 483 lock_buffer(bh); 484 memset(bh->b_data, 0, blocksize); 485 branch[n].p = (__le32 *) bh->b_data + offsets[n]; 486 branch[n].key = cpu_to_le32(new_blocks[n]); 487 *branch[n].p = branch[n].key; 488 if ( n == indirect_blks) { 489 current_block = new_blocks[n]; 490 /* 491 * End of chain, update the last new metablock of 492 * the chain to point to the new allocated 493 * data blocks numbers 494 */ 495 for (i=1; i < num; i++) 496 *(branch[n].p + i) = cpu_to_le32(++current_block); 497 } 498 set_buffer_uptodate(bh); 499 unlock_buffer(bh); 500 mark_buffer_dirty_inode(bh, inode); 501 /* We used to sync bh here if IS_SYNC(inode). 502 * But we now rely upon generic_write_sync() 503 * and b_inode_buffers. But not for directories. 504 */ 505 if (S_ISDIR(inode->i_mode) && IS_DIRSYNC(inode)) 506 sync_dirty_buffer(bh); 507 } 508 *blks = num; 509 return err; 510 } 511 512 /** 513 * ext2_splice_branch - splice the allocated branch onto inode. 514 * @inode: owner 515 * @block: (logical) number of block we are adding 516 * @where: location of missing link 517 * @num: number of indirect blocks we are adding 518 * @blks: number of direct blocks we are adding 519 * 520 * This function fills the missing link and does all housekeeping needed in 521 * inode (->i_blocks, etc.). In case of success we end up with the full 522 * chain to new block and return 0. 523 */ 524 static void ext2_splice_branch(struct inode *inode, 525 long block, Indirect *where, int num, int blks) 526 { 527 int i; 528 struct ext2_block_alloc_info *block_i; 529 ext2_fsblk_t current_block; 530 531 block_i = EXT2_I(inode)->i_block_alloc_info; 532 533 /* XXX LOCKING probably should have i_meta_lock ?*/ 534 /* That's it */ 535 536 *where->p = where->key; 537 538 /* 539 * Update the host buffer_head or inode to point to more just allocated 540 * direct blocks blocks 541 */ 542 if (num == 0 && blks > 1) { 543 current_block = le32_to_cpu(where->key) + 1; 544 for (i = 1; i < blks; i++) 545 *(where->p + i ) = cpu_to_le32(current_block++); 546 } 547 548 /* 549 * update the most recently allocated logical & physical block 550 * in i_block_alloc_info, to assist find the proper goal block for next 551 * allocation 552 */ 553 if (block_i) { 554 block_i->last_alloc_logical_block = block + blks - 1; 555 block_i->last_alloc_physical_block = 556 le32_to_cpu(where[num].key) + blks - 1; 557 } 558 559 /* We are done with atomic stuff, now do the rest of housekeeping */ 560 561 /* had we spliced it onto indirect block? */ 562 if (where->bh) 563 mark_buffer_dirty_inode(where->bh, inode); 564 565 inode->i_ctime = CURRENT_TIME_SEC; 566 mark_inode_dirty(inode); 567 } 568 569 /* 570 * Allocation strategy is simple: if we have to allocate something, we will 571 * have to go the whole way to leaf. So let's do it before attaching anything 572 * to tree, set linkage between the newborn blocks, write them if sync is 573 * required, recheck the path, free and repeat if check fails, otherwise 574 * set the last missing link (that will protect us from any truncate-generated 575 * removals - all blocks on the path are immune now) and possibly force the 576 * write on the parent block. 577 * That has a nice additional property: no special recovery from the failed 578 * allocations is needed - we simply release blocks and do not touch anything 579 * reachable from inode. 580 * 581 * `handle' can be NULL if create == 0. 582 * 583 * return > 0, # of blocks mapped or allocated. 584 * return = 0, if plain lookup failed. 585 * return < 0, error case. 586 */ 587 static int ext2_get_blocks(struct inode *inode, 588 sector_t iblock, unsigned long maxblocks, 589 struct buffer_head *bh_result, 590 int create) 591 { 592 int err = -EIO; 593 int offsets[4]; 594 Indirect chain[4]; 595 Indirect *partial; 596 ext2_fsblk_t goal; 597 int indirect_blks; 598 int blocks_to_boundary = 0; 599 int depth; 600 struct ext2_inode_info *ei = EXT2_I(inode); 601 int count = 0; 602 ext2_fsblk_t first_block = 0; 603 604 depth = ext2_block_to_path(inode,iblock,offsets,&blocks_to_boundary); 605 606 if (depth == 0) 607 return (err); 608 609 partial = ext2_get_branch(inode, depth, offsets, chain, &err); 610 /* Simplest case - block found, no allocation needed */ 611 if (!partial) { 612 first_block = le32_to_cpu(chain[depth - 1].key); 613 clear_buffer_new(bh_result); /* What's this do? */ 614 count++; 615 /*map more blocks*/ 616 while (count < maxblocks && count <= blocks_to_boundary) { 617 ext2_fsblk_t blk; 618 619 if (!verify_chain(chain, chain + depth - 1)) { 620 /* 621 * Indirect block might be removed by 622 * truncate while we were reading it. 623 * Handling of that case: forget what we've 624 * got now, go to reread. 625 */ 626 err = -EAGAIN; 627 count = 0; 628 break; 629 } 630 blk = le32_to_cpu(*(chain[depth-1].p + count)); 631 if (blk == first_block + count) 632 count++; 633 else 634 break; 635 } 636 if (err != -EAGAIN) 637 goto got_it; 638 } 639 640 /* Next simple case - plain lookup or failed read of indirect block */ 641 if (!create || err == -EIO) 642 goto cleanup; 643 644 mutex_lock(&ei->truncate_mutex); 645 /* 646 * If the indirect block is missing while we are reading 647 * the chain(ext3_get_branch() returns -EAGAIN err), or 648 * if the chain has been changed after we grab the semaphore, 649 * (either because another process truncated this branch, or 650 * another get_block allocated this branch) re-grab the chain to see if 651 * the request block has been allocated or not. 652 * 653 * Since we already block the truncate/other get_block 654 * at this point, we will have the current copy of the chain when we 655 * splice the branch into the tree. 656 */ 657 if (err == -EAGAIN || !verify_chain(chain, partial)) { 658 while (partial > chain) { 659 brelse(partial->bh); 660 partial--; 661 } 662 partial = ext2_get_branch(inode, depth, offsets, chain, &err); 663 if (!partial) { 664 count++; 665 mutex_unlock(&ei->truncate_mutex); 666 if (err) 667 goto cleanup; 668 clear_buffer_new(bh_result); 669 goto got_it; 670 } 671 } 672 673 /* 674 * Okay, we need to do block allocation. Lazily initialize the block 675 * allocation info here if necessary 676 */ 677 if (S_ISREG(inode->i_mode) && (!ei->i_block_alloc_info)) 678 ext2_init_block_alloc_info(inode); 679 680 goal = ext2_find_goal(inode, iblock, partial); 681 682 /* the number of blocks need to allocate for [d,t]indirect blocks */ 683 indirect_blks = (chain + depth) - partial - 1; 684 /* 685 * Next look up the indirect map to count the totoal number of 686 * direct blocks to allocate for this branch. 687 */ 688 count = ext2_blks_to_allocate(partial, indirect_blks, 689 maxblocks, blocks_to_boundary); 690 /* 691 * XXX ???? Block out ext2_truncate while we alter the tree 692 */ 693 err = ext2_alloc_branch(inode, indirect_blks, &count, goal, 694 offsets + (partial - chain), partial); 695 696 if (err) { 697 mutex_unlock(&ei->truncate_mutex); 698 goto cleanup; 699 } 700 701 if (ext2_use_xip(inode->i_sb)) { 702 /* 703 * we need to clear the block 704 */ 705 err = ext2_clear_xip_target (inode, 706 le32_to_cpu(chain[depth-1].key)); 707 if (err) { 708 mutex_unlock(&ei->truncate_mutex); 709 goto cleanup; 710 } 711 } 712 713 ext2_splice_branch(inode, iblock, partial, indirect_blks, count); 714 mutex_unlock(&ei->truncate_mutex); 715 set_buffer_new(bh_result); 716 got_it: 717 map_bh(bh_result, inode->i_sb, le32_to_cpu(chain[depth-1].key)); 718 if (count > blocks_to_boundary) 719 set_buffer_boundary(bh_result); 720 err = count; 721 /* Clean up and exit */ 722 partial = chain + depth - 1; /* the whole chain */ 723 cleanup: 724 while (partial > chain) { 725 brelse(partial->bh); 726 partial--; 727 } 728 return err; 729 } 730 731 int ext2_get_block(struct inode *inode, sector_t iblock, struct buffer_head *bh_result, int create) 732 { 733 unsigned max_blocks = bh_result->b_size >> inode->i_blkbits; 734 int ret = ext2_get_blocks(inode, iblock, max_blocks, 735 bh_result, create); 736 if (ret > 0) { 737 bh_result->b_size = (ret << inode->i_blkbits); 738 ret = 0; 739 } 740 return ret; 741 742 } 743 744 int ext2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, 745 u64 start, u64 len) 746 { 747 return generic_block_fiemap(inode, fieinfo, start, len, 748 ext2_get_block); 749 } 750 751 static int ext2_writepage(struct page *page, struct writeback_control *wbc) 752 { 753 return block_write_full_page(page, ext2_get_block, wbc); 754 } 755 756 static int ext2_readpage(struct file *file, struct page *page) 757 { 758 return mpage_readpage(page, ext2_get_block); 759 } 760 761 static int 762 ext2_readpages(struct file *file, struct address_space *mapping, 763 struct list_head *pages, unsigned nr_pages) 764 { 765 return mpage_readpages(mapping, pages, nr_pages, ext2_get_block); 766 } 767 768 static int 769 ext2_write_begin(struct file *file, struct address_space *mapping, 770 loff_t pos, unsigned len, unsigned flags, 771 struct page **pagep, void **fsdata) 772 { 773 int ret; 774 775 *pagep = NULL; 776 ret = block_write_begin_newtrunc(file, mapping, pos, len, flags, 777 pagep, fsdata, ext2_get_block); 778 if (ret < 0) 779 ext2_write_failed(mapping, pos + len); 780 return ret; 781 } 782 783 static int ext2_write_end(struct file *file, struct address_space *mapping, 784 loff_t pos, unsigned len, unsigned copied, 785 struct page *page, void *fsdata) 786 { 787 int ret; 788 789 ret = generic_write_end(file, mapping, pos, len, copied, page, fsdata); 790 if (ret < len) 791 ext2_write_failed(mapping, pos + len); 792 return ret; 793 } 794 795 static int 796 ext2_nobh_write_begin(struct file *file, struct address_space *mapping, 797 loff_t pos, unsigned len, unsigned flags, 798 struct page **pagep, void **fsdata) 799 { 800 int ret; 801 802 ret = nobh_write_begin(mapping, pos, len, flags, pagep, fsdata, 803 ext2_get_block); 804 if (ret < 0) 805 ext2_write_failed(mapping, pos + len); 806 return ret; 807 } 808 809 static int ext2_nobh_writepage(struct page *page, 810 struct writeback_control *wbc) 811 { 812 return nobh_writepage(page, ext2_get_block, wbc); 813 } 814 815 static sector_t ext2_bmap(struct address_space *mapping, sector_t block) 816 { 817 return generic_block_bmap(mapping,block,ext2_get_block); 818 } 819 820 static ssize_t 821 ext2_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov, 822 loff_t offset, unsigned long nr_segs) 823 { 824 struct file *file = iocb->ki_filp; 825 struct address_space *mapping = file->f_mapping; 826 struct inode *inode = mapping->host; 827 ssize_t ret; 828 829 ret = blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev, 830 iov, offset, nr_segs, ext2_get_block, NULL); 831 if (ret < 0 && (rw & WRITE)) 832 ext2_write_failed(mapping, offset + iov_length(iov, nr_segs)); 833 return ret; 834 } 835 836 static int 837 ext2_writepages(struct address_space *mapping, struct writeback_control *wbc) 838 { 839 return mpage_writepages(mapping, wbc, ext2_get_block); 840 } 841 842 const struct address_space_operations ext2_aops = { 843 .readpage = ext2_readpage, 844 .readpages = ext2_readpages, 845 .writepage = ext2_writepage, 846 .sync_page = block_sync_page, 847 .write_begin = ext2_write_begin, 848 .write_end = ext2_write_end, 849 .bmap = ext2_bmap, 850 .direct_IO = ext2_direct_IO, 851 .writepages = ext2_writepages, 852 .migratepage = buffer_migrate_page, 853 .is_partially_uptodate = block_is_partially_uptodate, 854 .error_remove_page = generic_error_remove_page, 855 }; 856 857 const struct address_space_operations ext2_aops_xip = { 858 .bmap = ext2_bmap, 859 .get_xip_mem = ext2_get_xip_mem, 860 }; 861 862 const struct address_space_operations ext2_nobh_aops = { 863 .readpage = ext2_readpage, 864 .readpages = ext2_readpages, 865 .writepage = ext2_nobh_writepage, 866 .sync_page = block_sync_page, 867 .write_begin = ext2_nobh_write_begin, 868 .write_end = nobh_write_end, 869 .bmap = ext2_bmap, 870 .direct_IO = ext2_direct_IO, 871 .writepages = ext2_writepages, 872 .migratepage = buffer_migrate_page, 873 .error_remove_page = generic_error_remove_page, 874 }; 875 876 /* 877 * Probably it should be a library function... search for first non-zero word 878 * or memcmp with zero_page, whatever is better for particular architecture. 879 * Linus? 880 */ 881 static inline int all_zeroes(__le32 *p, __le32 *q) 882 { 883 while (p < q) 884 if (*p++) 885 return 0; 886 return 1; 887 } 888 889 /** 890 * ext2_find_shared - find the indirect blocks for partial truncation. 891 * @inode: inode in question 892 * @depth: depth of the affected branch 893 * @offsets: offsets of pointers in that branch (see ext2_block_to_path) 894 * @chain: place to store the pointers to partial indirect blocks 895 * @top: place to the (detached) top of branch 896 * 897 * This is a helper function used by ext2_truncate(). 898 * 899 * When we do truncate() we may have to clean the ends of several indirect 900 * blocks but leave the blocks themselves alive. Block is partially 901 * truncated if some data below the new i_size is refered from it (and 902 * it is on the path to the first completely truncated data block, indeed). 903 * We have to free the top of that path along with everything to the right 904 * of the path. Since no allocation past the truncation point is possible 905 * until ext2_truncate() finishes, we may safely do the latter, but top 906 * of branch may require special attention - pageout below the truncation 907 * point might try to populate it. 908 * 909 * We atomically detach the top of branch from the tree, store the block 910 * number of its root in *@top, pointers to buffer_heads of partially 911 * truncated blocks - in @chain[].bh and pointers to their last elements 912 * that should not be removed - in @chain[].p. Return value is the pointer 913 * to last filled element of @chain. 914 * 915 * The work left to caller to do the actual freeing of subtrees: 916 * a) free the subtree starting from *@top 917 * b) free the subtrees whose roots are stored in 918 * (@chain[i].p+1 .. end of @chain[i].bh->b_data) 919 * c) free the subtrees growing from the inode past the @chain[0].p 920 * (no partially truncated stuff there). 921 */ 922 923 static Indirect *ext2_find_shared(struct inode *inode, 924 int depth, 925 int offsets[4], 926 Indirect chain[4], 927 __le32 *top) 928 { 929 Indirect *partial, *p; 930 int k, err; 931 932 *top = 0; 933 for (k = depth; k > 1 && !offsets[k-1]; k--) 934 ; 935 partial = ext2_get_branch(inode, k, offsets, chain, &err); 936 if (!partial) 937 partial = chain + k-1; 938 /* 939 * If the branch acquired continuation since we've looked at it - 940 * fine, it should all survive and (new) top doesn't belong to us. 941 */ 942 write_lock(&EXT2_I(inode)->i_meta_lock); 943 if (!partial->key && *partial->p) { 944 write_unlock(&EXT2_I(inode)->i_meta_lock); 945 goto no_top; 946 } 947 for (p=partial; p>chain && all_zeroes((__le32*)p->bh->b_data,p->p); p--) 948 ; 949 /* 950 * OK, we've found the last block that must survive. The rest of our 951 * branch should be detached before unlocking. However, if that rest 952 * of branch is all ours and does not grow immediately from the inode 953 * it's easier to cheat and just decrement partial->p. 954 */ 955 if (p == chain + k - 1 && p > chain) { 956 p->p--; 957 } else { 958 *top = *p->p; 959 *p->p = 0; 960 } 961 write_unlock(&EXT2_I(inode)->i_meta_lock); 962 963 while(partial > p) 964 { 965 brelse(partial->bh); 966 partial--; 967 } 968 no_top: 969 return partial; 970 } 971 972 /** 973 * ext2_free_data - free a list of data blocks 974 * @inode: inode we are dealing with 975 * @p: array of block numbers 976 * @q: points immediately past the end of array 977 * 978 * We are freeing all blocks refered from that array (numbers are 979 * stored as little-endian 32-bit) and updating @inode->i_blocks 980 * appropriately. 981 */ 982 static inline void ext2_free_data(struct inode *inode, __le32 *p, __le32 *q) 983 { 984 unsigned long block_to_free = 0, count = 0; 985 unsigned long nr; 986 987 for ( ; p < q ; p++) { 988 nr = le32_to_cpu(*p); 989 if (nr) { 990 *p = 0; 991 /* accumulate blocks to free if they're contiguous */ 992 if (count == 0) 993 goto free_this; 994 else if (block_to_free == nr - count) 995 count++; 996 else { 997 mark_inode_dirty(inode); 998 ext2_free_blocks (inode, block_to_free, count); 999 free_this: 1000 block_to_free = nr; 1001 count = 1; 1002 } 1003 } 1004 } 1005 if (count > 0) { 1006 mark_inode_dirty(inode); 1007 ext2_free_blocks (inode, block_to_free, count); 1008 } 1009 } 1010 1011 /** 1012 * ext2_free_branches - free an array of branches 1013 * @inode: inode we are dealing with 1014 * @p: array of block numbers 1015 * @q: pointer immediately past the end of array 1016 * @depth: depth of the branches to free 1017 * 1018 * We are freeing all blocks refered from these branches (numbers are 1019 * stored as little-endian 32-bit) and updating @inode->i_blocks 1020 * appropriately. 1021 */ 1022 static void ext2_free_branches(struct inode *inode, __le32 *p, __le32 *q, int depth) 1023 { 1024 struct buffer_head * bh; 1025 unsigned long nr; 1026 1027 if (depth--) { 1028 int addr_per_block = EXT2_ADDR_PER_BLOCK(inode->i_sb); 1029 for ( ; p < q ; p++) { 1030 nr = le32_to_cpu(*p); 1031 if (!nr) 1032 continue; 1033 *p = 0; 1034 bh = sb_bread(inode->i_sb, nr); 1035 /* 1036 * A read failure? Report error and clear slot 1037 * (should be rare). 1038 */ 1039 if (!bh) { 1040 ext2_error(inode->i_sb, "ext2_free_branches", 1041 "Read failure, inode=%ld, block=%ld", 1042 inode->i_ino, nr); 1043 continue; 1044 } 1045 ext2_free_branches(inode, 1046 (__le32*)bh->b_data, 1047 (__le32*)bh->b_data + addr_per_block, 1048 depth); 1049 bforget(bh); 1050 ext2_free_blocks(inode, nr, 1); 1051 mark_inode_dirty(inode); 1052 } 1053 } else 1054 ext2_free_data(inode, p, q); 1055 } 1056 1057 static void __ext2_truncate_blocks(struct inode *inode, loff_t offset) 1058 { 1059 __le32 *i_data = EXT2_I(inode)->i_data; 1060 struct ext2_inode_info *ei = EXT2_I(inode); 1061 int addr_per_block = EXT2_ADDR_PER_BLOCK(inode->i_sb); 1062 int offsets[4]; 1063 Indirect chain[4]; 1064 Indirect *partial; 1065 __le32 nr = 0; 1066 int n; 1067 long iblock; 1068 unsigned blocksize; 1069 blocksize = inode->i_sb->s_blocksize; 1070 iblock = (offset + blocksize-1) >> EXT2_BLOCK_SIZE_BITS(inode->i_sb); 1071 1072 n = ext2_block_to_path(inode, iblock, offsets, NULL); 1073 if (n == 0) 1074 return; 1075 1076 /* 1077 * From here we block out all ext2_get_block() callers who want to 1078 * modify the block allocation tree. 1079 */ 1080 mutex_lock(&ei->truncate_mutex); 1081 1082 if (n == 1) { 1083 ext2_free_data(inode, i_data+offsets[0], 1084 i_data + EXT2_NDIR_BLOCKS); 1085 goto do_indirects; 1086 } 1087 1088 partial = ext2_find_shared(inode, n, offsets, chain, &nr); 1089 /* Kill the top of shared branch (already detached) */ 1090 if (nr) { 1091 if (partial == chain) 1092 mark_inode_dirty(inode); 1093 else 1094 mark_buffer_dirty_inode(partial->bh, inode); 1095 ext2_free_branches(inode, &nr, &nr+1, (chain+n-1) - partial); 1096 } 1097 /* Clear the ends of indirect blocks on the shared branch */ 1098 while (partial > chain) { 1099 ext2_free_branches(inode, 1100 partial->p + 1, 1101 (__le32*)partial->bh->b_data+addr_per_block, 1102 (chain+n-1) - partial); 1103 mark_buffer_dirty_inode(partial->bh, inode); 1104 brelse (partial->bh); 1105 partial--; 1106 } 1107 do_indirects: 1108 /* Kill the remaining (whole) subtrees */ 1109 switch (offsets[0]) { 1110 default: 1111 nr = i_data[EXT2_IND_BLOCK]; 1112 if (nr) { 1113 i_data[EXT2_IND_BLOCK] = 0; 1114 mark_inode_dirty(inode); 1115 ext2_free_branches(inode, &nr, &nr+1, 1); 1116 } 1117 case EXT2_IND_BLOCK: 1118 nr = i_data[EXT2_DIND_BLOCK]; 1119 if (nr) { 1120 i_data[EXT2_DIND_BLOCK] = 0; 1121 mark_inode_dirty(inode); 1122 ext2_free_branches(inode, &nr, &nr+1, 2); 1123 } 1124 case EXT2_DIND_BLOCK: 1125 nr = i_data[EXT2_TIND_BLOCK]; 1126 if (nr) { 1127 i_data[EXT2_TIND_BLOCK] = 0; 1128 mark_inode_dirty(inode); 1129 ext2_free_branches(inode, &nr, &nr+1, 3); 1130 } 1131 case EXT2_TIND_BLOCK: 1132 ; 1133 } 1134 1135 ext2_discard_reservation(inode); 1136 1137 mutex_unlock(&ei->truncate_mutex); 1138 } 1139 1140 static void ext2_truncate_blocks(struct inode *inode, loff_t offset) 1141 { 1142 /* 1143 * XXX: it seems like a bug here that we don't allow 1144 * IS_APPEND inode to have blocks-past-i_size trimmed off. 1145 * review and fix this. 1146 * 1147 * Also would be nice to be able to handle IO errors and such, 1148 * but that's probably too much to ask. 1149 */ 1150 if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || 1151 S_ISLNK(inode->i_mode))) 1152 return; 1153 if (ext2_inode_is_fast_symlink(inode)) 1154 return; 1155 if (IS_APPEND(inode) || IS_IMMUTABLE(inode)) 1156 return; 1157 __ext2_truncate_blocks(inode, offset); 1158 } 1159 1160 int ext2_setsize(struct inode *inode, loff_t newsize) 1161 { 1162 loff_t oldsize; 1163 int error; 1164 1165 error = inode_newsize_ok(inode, newsize); 1166 if (error) 1167 return error; 1168 1169 if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || 1170 S_ISLNK(inode->i_mode))) 1171 return -EINVAL; 1172 if (ext2_inode_is_fast_symlink(inode)) 1173 return -EINVAL; 1174 if (IS_APPEND(inode) || IS_IMMUTABLE(inode)) 1175 return -EPERM; 1176 1177 if (mapping_is_xip(inode->i_mapping)) 1178 error = xip_truncate_page(inode->i_mapping, newsize); 1179 else if (test_opt(inode->i_sb, NOBH)) 1180 error = nobh_truncate_page(inode->i_mapping, 1181 newsize, ext2_get_block); 1182 else 1183 error = block_truncate_page(inode->i_mapping, 1184 newsize, ext2_get_block); 1185 if (error) 1186 return error; 1187 1188 oldsize = inode->i_size; 1189 i_size_write(inode, newsize); 1190 truncate_pagecache(inode, oldsize, newsize); 1191 1192 __ext2_truncate_blocks(inode, newsize); 1193 1194 inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC; 1195 if (inode_needs_sync(inode)) { 1196 sync_mapping_buffers(inode->i_mapping); 1197 ext2_sync_inode (inode); 1198 } else { 1199 mark_inode_dirty(inode); 1200 } 1201 1202 return 0; 1203 } 1204 1205 static struct ext2_inode *ext2_get_inode(struct super_block *sb, ino_t ino, 1206 struct buffer_head **p) 1207 { 1208 struct buffer_head * bh; 1209 unsigned long block_group; 1210 unsigned long block; 1211 unsigned long offset; 1212 struct ext2_group_desc * gdp; 1213 1214 *p = NULL; 1215 if ((ino != EXT2_ROOT_INO && ino < EXT2_FIRST_INO(sb)) || 1216 ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count)) 1217 goto Einval; 1218 1219 block_group = (ino - 1) / EXT2_INODES_PER_GROUP(sb); 1220 gdp = ext2_get_group_desc(sb, block_group, NULL); 1221 if (!gdp) 1222 goto Egdp; 1223 /* 1224 * Figure out the offset within the block group inode table 1225 */ 1226 offset = ((ino - 1) % EXT2_INODES_PER_GROUP(sb)) * EXT2_INODE_SIZE(sb); 1227 block = le32_to_cpu(gdp->bg_inode_table) + 1228 (offset >> EXT2_BLOCK_SIZE_BITS(sb)); 1229 if (!(bh = sb_bread(sb, block))) 1230 goto Eio; 1231 1232 *p = bh; 1233 offset &= (EXT2_BLOCK_SIZE(sb) - 1); 1234 return (struct ext2_inode *) (bh->b_data + offset); 1235 1236 Einval: 1237 ext2_error(sb, "ext2_get_inode", "bad inode number: %lu", 1238 (unsigned long) ino); 1239 return ERR_PTR(-EINVAL); 1240 Eio: 1241 ext2_error(sb, "ext2_get_inode", 1242 "unable to read inode block - inode=%lu, block=%lu", 1243 (unsigned long) ino, block); 1244 Egdp: 1245 return ERR_PTR(-EIO); 1246 } 1247 1248 void ext2_set_inode_flags(struct inode *inode) 1249 { 1250 unsigned int flags = EXT2_I(inode)->i_flags; 1251 1252 inode->i_flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC); 1253 if (flags & EXT2_SYNC_FL) 1254 inode->i_flags |= S_SYNC; 1255 if (flags & EXT2_APPEND_FL) 1256 inode->i_flags |= S_APPEND; 1257 if (flags & EXT2_IMMUTABLE_FL) 1258 inode->i_flags |= S_IMMUTABLE; 1259 if (flags & EXT2_NOATIME_FL) 1260 inode->i_flags |= S_NOATIME; 1261 if (flags & EXT2_DIRSYNC_FL) 1262 inode->i_flags |= S_DIRSYNC; 1263 } 1264 1265 /* Propagate flags from i_flags to EXT2_I(inode)->i_flags */ 1266 void ext2_get_inode_flags(struct ext2_inode_info *ei) 1267 { 1268 unsigned int flags = ei->vfs_inode.i_flags; 1269 1270 ei->i_flags &= ~(EXT2_SYNC_FL|EXT2_APPEND_FL| 1271 EXT2_IMMUTABLE_FL|EXT2_NOATIME_FL|EXT2_DIRSYNC_FL); 1272 if (flags & S_SYNC) 1273 ei->i_flags |= EXT2_SYNC_FL; 1274 if (flags & S_APPEND) 1275 ei->i_flags |= EXT2_APPEND_FL; 1276 if (flags & S_IMMUTABLE) 1277 ei->i_flags |= EXT2_IMMUTABLE_FL; 1278 if (flags & S_NOATIME) 1279 ei->i_flags |= EXT2_NOATIME_FL; 1280 if (flags & S_DIRSYNC) 1281 ei->i_flags |= EXT2_DIRSYNC_FL; 1282 } 1283 1284 struct inode *ext2_iget (struct super_block *sb, unsigned long ino) 1285 { 1286 struct ext2_inode_info *ei; 1287 struct buffer_head * bh; 1288 struct ext2_inode *raw_inode; 1289 struct inode *inode; 1290 long ret = -EIO; 1291 int n; 1292 1293 inode = iget_locked(sb, ino); 1294 if (!inode) 1295 return ERR_PTR(-ENOMEM); 1296 if (!(inode->i_state & I_NEW)) 1297 return inode; 1298 1299 ei = EXT2_I(inode); 1300 ei->i_block_alloc_info = NULL; 1301 1302 raw_inode = ext2_get_inode(inode->i_sb, ino, &bh); 1303 if (IS_ERR(raw_inode)) { 1304 ret = PTR_ERR(raw_inode); 1305 goto bad_inode; 1306 } 1307 1308 inode->i_mode = le16_to_cpu(raw_inode->i_mode); 1309 inode->i_uid = (uid_t)le16_to_cpu(raw_inode->i_uid_low); 1310 inode->i_gid = (gid_t)le16_to_cpu(raw_inode->i_gid_low); 1311 if (!(test_opt (inode->i_sb, NO_UID32))) { 1312 inode->i_uid |= le16_to_cpu(raw_inode->i_uid_high) << 16; 1313 inode->i_gid |= le16_to_cpu(raw_inode->i_gid_high) << 16; 1314 } 1315 inode->i_nlink = le16_to_cpu(raw_inode->i_links_count); 1316 inode->i_size = le32_to_cpu(raw_inode->i_size); 1317 inode->i_atime.tv_sec = (signed)le32_to_cpu(raw_inode->i_atime); 1318 inode->i_ctime.tv_sec = (signed)le32_to_cpu(raw_inode->i_ctime); 1319 inode->i_mtime.tv_sec = (signed)le32_to_cpu(raw_inode->i_mtime); 1320 inode->i_atime.tv_nsec = inode->i_mtime.tv_nsec = inode->i_ctime.tv_nsec = 0; 1321 ei->i_dtime = le32_to_cpu(raw_inode->i_dtime); 1322 /* We now have enough fields to check if the inode was active or not. 1323 * This is needed because nfsd might try to access dead inodes 1324 * the test is that same one that e2fsck uses 1325 * NeilBrown 1999oct15 1326 */ 1327 if (inode->i_nlink == 0 && (inode->i_mode == 0 || ei->i_dtime)) { 1328 /* this inode is deleted */ 1329 brelse (bh); 1330 ret = -ESTALE; 1331 goto bad_inode; 1332 } 1333 inode->i_blocks = le32_to_cpu(raw_inode->i_blocks); 1334 ei->i_flags = le32_to_cpu(raw_inode->i_flags); 1335 ei->i_faddr = le32_to_cpu(raw_inode->i_faddr); 1336 ei->i_frag_no = raw_inode->i_frag; 1337 ei->i_frag_size = raw_inode->i_fsize; 1338 ei->i_file_acl = le32_to_cpu(raw_inode->i_file_acl); 1339 ei->i_dir_acl = 0; 1340 if (S_ISREG(inode->i_mode)) 1341 inode->i_size |= ((__u64)le32_to_cpu(raw_inode->i_size_high)) << 32; 1342 else 1343 ei->i_dir_acl = le32_to_cpu(raw_inode->i_dir_acl); 1344 ei->i_dtime = 0; 1345 inode->i_generation = le32_to_cpu(raw_inode->i_generation); 1346 ei->i_state = 0; 1347 ei->i_block_group = (ino - 1) / EXT2_INODES_PER_GROUP(inode->i_sb); 1348 ei->i_dir_start_lookup = 0; 1349 1350 /* 1351 * NOTE! The in-memory inode i_data array is in little-endian order 1352 * even on big-endian machines: we do NOT byteswap the block numbers! 1353 */ 1354 for (n = 0; n < EXT2_N_BLOCKS; n++) 1355 ei->i_data[n] = raw_inode->i_block[n]; 1356 1357 if (S_ISREG(inode->i_mode)) { 1358 inode->i_op = &ext2_file_inode_operations; 1359 if (ext2_use_xip(inode->i_sb)) { 1360 inode->i_mapping->a_ops = &ext2_aops_xip; 1361 inode->i_fop = &ext2_xip_file_operations; 1362 } else if (test_opt(inode->i_sb, NOBH)) { 1363 inode->i_mapping->a_ops = &ext2_nobh_aops; 1364 inode->i_fop = &ext2_file_operations; 1365 } else { 1366 inode->i_mapping->a_ops = &ext2_aops; 1367 inode->i_fop = &ext2_file_operations; 1368 } 1369 } else if (S_ISDIR(inode->i_mode)) { 1370 inode->i_op = &ext2_dir_inode_operations; 1371 inode->i_fop = &ext2_dir_operations; 1372 if (test_opt(inode->i_sb, NOBH)) 1373 inode->i_mapping->a_ops = &ext2_nobh_aops; 1374 else 1375 inode->i_mapping->a_ops = &ext2_aops; 1376 } else if (S_ISLNK(inode->i_mode)) { 1377 if (ext2_inode_is_fast_symlink(inode)) { 1378 inode->i_op = &ext2_fast_symlink_inode_operations; 1379 nd_terminate_link(ei->i_data, inode->i_size, 1380 sizeof(ei->i_data) - 1); 1381 } else { 1382 inode->i_op = &ext2_symlink_inode_operations; 1383 if (test_opt(inode->i_sb, NOBH)) 1384 inode->i_mapping->a_ops = &ext2_nobh_aops; 1385 else 1386 inode->i_mapping->a_ops = &ext2_aops; 1387 } 1388 } else { 1389 inode->i_op = &ext2_special_inode_operations; 1390 if (raw_inode->i_block[0]) 1391 init_special_inode(inode, inode->i_mode, 1392 old_decode_dev(le32_to_cpu(raw_inode->i_block[0]))); 1393 else 1394 init_special_inode(inode, inode->i_mode, 1395 new_decode_dev(le32_to_cpu(raw_inode->i_block[1]))); 1396 } 1397 brelse (bh); 1398 ext2_set_inode_flags(inode); 1399 unlock_new_inode(inode); 1400 return inode; 1401 1402 bad_inode: 1403 iget_failed(inode); 1404 return ERR_PTR(ret); 1405 } 1406 1407 static int __ext2_write_inode(struct inode *inode, int do_sync) 1408 { 1409 struct ext2_inode_info *ei = EXT2_I(inode); 1410 struct super_block *sb = inode->i_sb; 1411 ino_t ino = inode->i_ino; 1412 uid_t uid = inode->i_uid; 1413 gid_t gid = inode->i_gid; 1414 struct buffer_head * bh; 1415 struct ext2_inode * raw_inode = ext2_get_inode(sb, ino, &bh); 1416 int n; 1417 int err = 0; 1418 1419 if (IS_ERR(raw_inode)) 1420 return -EIO; 1421 1422 /* For fields not not tracking in the in-memory inode, 1423 * initialise them to zero for new inodes. */ 1424 if (ei->i_state & EXT2_STATE_NEW) 1425 memset(raw_inode, 0, EXT2_SB(sb)->s_inode_size); 1426 1427 ext2_get_inode_flags(ei); 1428 raw_inode->i_mode = cpu_to_le16(inode->i_mode); 1429 if (!(test_opt(sb, NO_UID32))) { 1430 raw_inode->i_uid_low = cpu_to_le16(low_16_bits(uid)); 1431 raw_inode->i_gid_low = cpu_to_le16(low_16_bits(gid)); 1432 /* 1433 * Fix up interoperability with old kernels. Otherwise, old inodes get 1434 * re-used with the upper 16 bits of the uid/gid intact 1435 */ 1436 if (!ei->i_dtime) { 1437 raw_inode->i_uid_high = cpu_to_le16(high_16_bits(uid)); 1438 raw_inode->i_gid_high = cpu_to_le16(high_16_bits(gid)); 1439 } else { 1440 raw_inode->i_uid_high = 0; 1441 raw_inode->i_gid_high = 0; 1442 } 1443 } else { 1444 raw_inode->i_uid_low = cpu_to_le16(fs_high2lowuid(uid)); 1445 raw_inode->i_gid_low = cpu_to_le16(fs_high2lowgid(gid)); 1446 raw_inode->i_uid_high = 0; 1447 raw_inode->i_gid_high = 0; 1448 } 1449 raw_inode->i_links_count = cpu_to_le16(inode->i_nlink); 1450 raw_inode->i_size = cpu_to_le32(inode->i_size); 1451 raw_inode->i_atime = cpu_to_le32(inode->i_atime.tv_sec); 1452 raw_inode->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec); 1453 raw_inode->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec); 1454 1455 raw_inode->i_blocks = cpu_to_le32(inode->i_blocks); 1456 raw_inode->i_dtime = cpu_to_le32(ei->i_dtime); 1457 raw_inode->i_flags = cpu_to_le32(ei->i_flags); 1458 raw_inode->i_faddr = cpu_to_le32(ei->i_faddr); 1459 raw_inode->i_frag = ei->i_frag_no; 1460 raw_inode->i_fsize = ei->i_frag_size; 1461 raw_inode->i_file_acl = cpu_to_le32(ei->i_file_acl); 1462 if (!S_ISREG(inode->i_mode)) 1463 raw_inode->i_dir_acl = cpu_to_le32(ei->i_dir_acl); 1464 else { 1465 raw_inode->i_size_high = cpu_to_le32(inode->i_size >> 32); 1466 if (inode->i_size > 0x7fffffffULL) { 1467 if (!EXT2_HAS_RO_COMPAT_FEATURE(sb, 1468 EXT2_FEATURE_RO_COMPAT_LARGE_FILE) || 1469 EXT2_SB(sb)->s_es->s_rev_level == 1470 cpu_to_le32(EXT2_GOOD_OLD_REV)) { 1471 /* If this is the first large file 1472 * created, add a flag to the superblock. 1473 */ 1474 spin_lock(&EXT2_SB(sb)->s_lock); 1475 ext2_update_dynamic_rev(sb); 1476 EXT2_SET_RO_COMPAT_FEATURE(sb, 1477 EXT2_FEATURE_RO_COMPAT_LARGE_FILE); 1478 spin_unlock(&EXT2_SB(sb)->s_lock); 1479 ext2_write_super(sb); 1480 } 1481 } 1482 } 1483 1484 raw_inode->i_generation = cpu_to_le32(inode->i_generation); 1485 if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) { 1486 if (old_valid_dev(inode->i_rdev)) { 1487 raw_inode->i_block[0] = 1488 cpu_to_le32(old_encode_dev(inode->i_rdev)); 1489 raw_inode->i_block[1] = 0; 1490 } else { 1491 raw_inode->i_block[0] = 0; 1492 raw_inode->i_block[1] = 1493 cpu_to_le32(new_encode_dev(inode->i_rdev)); 1494 raw_inode->i_block[2] = 0; 1495 } 1496 } else for (n = 0; n < EXT2_N_BLOCKS; n++) 1497 raw_inode->i_block[n] = ei->i_data[n]; 1498 mark_buffer_dirty(bh); 1499 if (do_sync) { 1500 sync_dirty_buffer(bh); 1501 if (buffer_req(bh) && !buffer_uptodate(bh)) { 1502 printk ("IO error syncing ext2 inode [%s:%08lx]\n", 1503 sb->s_id, (unsigned long) ino); 1504 err = -EIO; 1505 } 1506 } 1507 ei->i_state &= ~EXT2_STATE_NEW; 1508 brelse (bh); 1509 return err; 1510 } 1511 1512 int ext2_write_inode(struct inode *inode, struct writeback_control *wbc) 1513 { 1514 return __ext2_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL); 1515 } 1516 1517 int ext2_sync_inode(struct inode *inode) 1518 { 1519 struct writeback_control wbc = { 1520 .sync_mode = WB_SYNC_ALL, 1521 .nr_to_write = 0, /* sys_fsync did this */ 1522 }; 1523 return sync_inode(inode, &wbc); 1524 } 1525 1526 int ext2_setattr(struct dentry *dentry, struct iattr *iattr) 1527 { 1528 struct inode *inode = dentry->d_inode; 1529 int error; 1530 1531 error = inode_change_ok(inode, iattr); 1532 if (error) 1533 return error; 1534 1535 if (is_quota_modification(inode, iattr)) 1536 dquot_initialize(inode); 1537 if ((iattr->ia_valid & ATTR_UID && iattr->ia_uid != inode->i_uid) || 1538 (iattr->ia_valid & ATTR_GID && iattr->ia_gid != inode->i_gid)) { 1539 error = dquot_transfer(inode, iattr); 1540 if (error) 1541 return error; 1542 } 1543 if (iattr->ia_valid & ATTR_SIZE && iattr->ia_size != inode->i_size) { 1544 error = ext2_setsize(inode, iattr->ia_size); 1545 if (error) 1546 return error; 1547 } 1548 generic_setattr(inode, iattr); 1549 if (iattr->ia_valid & ATTR_MODE) 1550 error = ext2_acl_chmod(inode); 1551 mark_inode_dirty(inode); 1552 1553 return error; 1554 } 1555