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/smp_lock.h> 26 #include <linux/time.h> 27 #include <linux/highuid.h> 28 #include <linux/pagemap.h> 29 #include <linux/quotaops.h> 30 #include <linux/module.h> 31 #include <linux/writeback.h> 32 #include <linux/buffer_head.h> 33 #include <linux/mpage.h> 34 #include "ext2.h" 35 #include "acl.h" 36 #include "xip.h" 37 38 MODULE_AUTHOR("Remy Card and others"); 39 MODULE_DESCRIPTION("Second Extended Filesystem"); 40 MODULE_LICENSE("GPL"); 41 42 static int ext2_update_inode(struct inode * inode, int do_sync); 43 44 /* 45 * Test whether an inode is a fast symlink. 46 */ 47 static inline int ext2_inode_is_fast_symlink(struct inode *inode) 48 { 49 int ea_blocks = EXT2_I(inode)->i_file_acl ? 50 (inode->i_sb->s_blocksize >> 9) : 0; 51 52 return (S_ISLNK(inode->i_mode) && 53 inode->i_blocks - ea_blocks == 0); 54 } 55 56 /* 57 * Called at the last iput() if i_nlink is zero. 58 */ 59 void ext2_delete_inode (struct inode * inode) 60 { 61 truncate_inode_pages(&inode->i_data, 0); 62 63 if (is_bad_inode(inode)) 64 goto no_delete; 65 EXT2_I(inode)->i_dtime = get_seconds(); 66 mark_inode_dirty(inode); 67 ext2_update_inode(inode, inode_needs_sync(inode)); 68 69 inode->i_size = 0; 70 if (inode->i_blocks) 71 ext2_truncate (inode); 72 ext2_free_inode (inode); 73 74 return; 75 no_delete: 76 clear_inode(inode); /* We must guarantee clearing of inode... */ 77 } 78 79 typedef struct { 80 __le32 *p; 81 __le32 key; 82 struct buffer_head *bh; 83 } Indirect; 84 85 static inline void add_chain(Indirect *p, struct buffer_head *bh, __le32 *v) 86 { 87 p->key = *(p->p = v); 88 p->bh = bh; 89 } 90 91 static inline int verify_chain(Indirect *from, Indirect *to) 92 { 93 while (from <= to && from->key == *from->p) 94 from++; 95 return (from > to); 96 } 97 98 /** 99 * ext2_block_to_path - parse the block number into array of offsets 100 * @inode: inode in question (we are only interested in its superblock) 101 * @i_block: block number to be parsed 102 * @offsets: array to store the offsets in 103 * @boundary: set this non-zero if the referred-to block is likely to be 104 * followed (on disk) by an indirect block. 105 * To store the locations of file's data ext2 uses a data structure common 106 * for UNIX filesystems - tree of pointers anchored in the inode, with 107 * data blocks at leaves and indirect blocks in intermediate nodes. 108 * This function translates the block number into path in that tree - 109 * return value is the path length and @offsets[n] is the offset of 110 * pointer to (n+1)th node in the nth one. If @block is out of range 111 * (negative or too large) warning is printed and zero returned. 112 * 113 * Note: function doesn't find node addresses, so no IO is needed. All 114 * we need to know is the capacity of indirect blocks (taken from the 115 * inode->i_sb). 116 */ 117 118 /* 119 * Portability note: the last comparison (check that we fit into triple 120 * indirect block) is spelled differently, because otherwise on an 121 * architecture with 32-bit longs and 8Kb pages we might get into trouble 122 * if our filesystem had 8Kb blocks. We might use long long, but that would 123 * kill us on x86. Oh, well, at least the sign propagation does not matter - 124 * i_block would have to be negative in the very beginning, so we would not 125 * get there at all. 126 */ 127 128 static int ext2_block_to_path(struct inode *inode, 129 long i_block, int offsets[4], int *boundary) 130 { 131 int ptrs = EXT2_ADDR_PER_BLOCK(inode->i_sb); 132 int ptrs_bits = EXT2_ADDR_PER_BLOCK_BITS(inode->i_sb); 133 const long direct_blocks = EXT2_NDIR_BLOCKS, 134 indirect_blocks = ptrs, 135 double_blocks = (1 << (ptrs_bits * 2)); 136 int n = 0; 137 int final = 0; 138 139 if (i_block < 0) { 140 ext2_warning (inode->i_sb, "ext2_block_to_path", "block < 0"); 141 } else if (i_block < direct_blocks) { 142 offsets[n++] = i_block; 143 final = direct_blocks; 144 } else if ( (i_block -= direct_blocks) < indirect_blocks) { 145 offsets[n++] = EXT2_IND_BLOCK; 146 offsets[n++] = i_block; 147 final = ptrs; 148 } else if ((i_block -= indirect_blocks) < double_blocks) { 149 offsets[n++] = EXT2_DIND_BLOCK; 150 offsets[n++] = i_block >> ptrs_bits; 151 offsets[n++] = i_block & (ptrs - 1); 152 final = ptrs; 153 } else if (((i_block -= double_blocks) >> (ptrs_bits * 2)) < ptrs) { 154 offsets[n++] = EXT2_TIND_BLOCK; 155 offsets[n++] = i_block >> (ptrs_bits * 2); 156 offsets[n++] = (i_block >> ptrs_bits) & (ptrs - 1); 157 offsets[n++] = i_block & (ptrs - 1); 158 final = ptrs; 159 } else { 160 ext2_warning (inode->i_sb, "ext2_block_to_path", "block > big"); 161 } 162 if (boundary) 163 *boundary = final - 1 - (i_block & (ptrs - 1)); 164 165 return n; 166 } 167 168 /** 169 * ext2_get_branch - read the chain of indirect blocks leading to data 170 * @inode: inode in question 171 * @depth: depth of the chain (1 - direct pointer, etc.) 172 * @offsets: offsets of pointers in inode/indirect blocks 173 * @chain: place to store the result 174 * @err: here we store the error value 175 * 176 * Function fills the array of triples <key, p, bh> and returns %NULL 177 * if everything went OK or the pointer to the last filled triple 178 * (incomplete one) otherwise. Upon the return chain[i].key contains 179 * the number of (i+1)-th block in the chain (as it is stored in memory, 180 * i.e. little-endian 32-bit), chain[i].p contains the address of that 181 * number (it points into struct inode for i==0 and into the bh->b_data 182 * for i>0) and chain[i].bh points to the buffer_head of i-th indirect 183 * block for i>0 and NULL for i==0. In other words, it holds the block 184 * numbers of the chain, addresses they were taken from (and where we can 185 * verify that chain did not change) and buffer_heads hosting these 186 * numbers. 187 * 188 * Function stops when it stumbles upon zero pointer (absent block) 189 * (pointer to last triple returned, *@err == 0) 190 * or when it gets an IO error reading an indirect block 191 * (ditto, *@err == -EIO) 192 * or when it notices that chain had been changed while it was reading 193 * (ditto, *@err == -EAGAIN) 194 * or when it reads all @depth-1 indirect blocks successfully and finds 195 * the whole chain, all way to the data (returns %NULL, *err == 0). 196 */ 197 static Indirect *ext2_get_branch(struct inode *inode, 198 int depth, 199 int *offsets, 200 Indirect chain[4], 201 int *err) 202 { 203 struct super_block *sb = inode->i_sb; 204 Indirect *p = chain; 205 struct buffer_head *bh; 206 207 *err = 0; 208 /* i_data is not going away, no lock needed */ 209 add_chain (chain, NULL, EXT2_I(inode)->i_data + *offsets); 210 if (!p->key) 211 goto no_block; 212 while (--depth) { 213 bh = sb_bread(sb, le32_to_cpu(p->key)); 214 if (!bh) 215 goto failure; 216 read_lock(&EXT2_I(inode)->i_meta_lock); 217 if (!verify_chain(chain, p)) 218 goto changed; 219 add_chain(++p, bh, (__le32*)bh->b_data + *++offsets); 220 read_unlock(&EXT2_I(inode)->i_meta_lock); 221 if (!p->key) 222 goto no_block; 223 } 224 return NULL; 225 226 changed: 227 read_unlock(&EXT2_I(inode)->i_meta_lock); 228 brelse(bh); 229 *err = -EAGAIN; 230 goto no_block; 231 failure: 232 *err = -EIO; 233 no_block: 234 return p; 235 } 236 237 /** 238 * ext2_find_near - find a place for allocation with sufficient locality 239 * @inode: owner 240 * @ind: descriptor of indirect block. 241 * 242 * This function returns the prefered place for block allocation. 243 * It is used when heuristic for sequential allocation fails. 244 * Rules are: 245 * + if there is a block to the left of our position - allocate near it. 246 * + if pointer will live in indirect block - allocate near that block. 247 * + if pointer will live in inode - allocate in the same cylinder group. 248 * 249 * In the latter case we colour the starting block by the callers PID to 250 * prevent it from clashing with concurrent allocations for a different inode 251 * in the same block group. The PID is used here so that functionally related 252 * files will be close-by on-disk. 253 * 254 * Caller must make sure that @ind is valid and will stay that way. 255 */ 256 257 static unsigned long ext2_find_near(struct inode *inode, Indirect *ind) 258 { 259 struct ext2_inode_info *ei = EXT2_I(inode); 260 __le32 *start = ind->bh ? (__le32 *) ind->bh->b_data : ei->i_data; 261 __le32 *p; 262 unsigned long bg_start; 263 unsigned long colour; 264 265 /* Try to find previous block */ 266 for (p = ind->p - 1; p >= start; p--) 267 if (*p) 268 return le32_to_cpu(*p); 269 270 /* No such thing, so let's try location of indirect block */ 271 if (ind->bh) 272 return ind->bh->b_blocknr; 273 274 /* 275 * It is going to be refered from inode itself? OK, just put it into 276 * the same cylinder group then. 277 */ 278 bg_start = (ei->i_block_group * EXT2_BLOCKS_PER_GROUP(inode->i_sb)) + 279 le32_to_cpu(EXT2_SB(inode->i_sb)->s_es->s_first_data_block); 280 colour = (current->pid % 16) * 281 (EXT2_BLOCKS_PER_GROUP(inode->i_sb) / 16); 282 return bg_start + colour; 283 } 284 285 /** 286 * ext2_find_goal - find a prefered place for allocation. 287 * @inode: owner 288 * @block: block we want 289 * @partial: pointer to the last triple within a chain 290 * 291 * Returns preferred place for a block (the goal). 292 */ 293 294 static inline int ext2_find_goal(struct inode *inode, long block, 295 Indirect *partial) 296 { 297 struct ext2_block_alloc_info *block_i; 298 299 block_i = EXT2_I(inode)->i_block_alloc_info; 300 301 /* 302 * try the heuristic for sequential allocation, 303 * failing that at least try to get decent locality. 304 */ 305 if (block_i && (block == block_i->last_alloc_logical_block + 1) 306 && (block_i->last_alloc_physical_block != 0)) { 307 return block_i->last_alloc_physical_block + 1; 308 } 309 310 return ext2_find_near(inode, partial); 311 } 312 313 /** 314 * ext2_blks_to_allocate: Look up the block map and count the number 315 * of direct blocks need to be allocated for the given branch. 316 * 317 * @branch: chain of indirect blocks 318 * @k: number of blocks need for indirect blocks 319 * @blks: number of data blocks to be mapped. 320 * @blocks_to_boundary: the offset in the indirect block 321 * 322 * return the total number of blocks to be allocate, including the 323 * direct and indirect blocks. 324 */ 325 static int 326 ext2_blks_to_allocate(Indirect * branch, int k, unsigned long blks, 327 int blocks_to_boundary) 328 { 329 unsigned long count = 0; 330 331 /* 332 * Simple case, [t,d]Indirect block(s) has not allocated yet 333 * then it's clear blocks on that path have not allocated 334 */ 335 if (k > 0) { 336 /* right now don't hanel cross boundary allocation */ 337 if (blks < blocks_to_boundary + 1) 338 count += blks; 339 else 340 count += blocks_to_boundary + 1; 341 return count; 342 } 343 344 count++; 345 while (count < blks && count <= blocks_to_boundary 346 && le32_to_cpu(*(branch[0].p + count)) == 0) { 347 count++; 348 } 349 return count; 350 } 351 352 /** 353 * ext2_alloc_blocks: multiple allocate blocks needed for a branch 354 * @indirect_blks: the number of blocks need to allocate for indirect 355 * blocks 356 * 357 * @new_blocks: on return it will store the new block numbers for 358 * the indirect blocks(if needed) and the first direct block, 359 * @blks: on return it will store the total number of allocated 360 * direct blocks 361 */ 362 static int ext2_alloc_blocks(struct inode *inode, 363 ext2_fsblk_t goal, int indirect_blks, int blks, 364 ext2_fsblk_t new_blocks[4], int *err) 365 { 366 int target, i; 367 unsigned long count = 0; 368 int index = 0; 369 ext2_fsblk_t current_block = 0; 370 int ret = 0; 371 372 /* 373 * Here we try to allocate the requested multiple blocks at once, 374 * on a best-effort basis. 375 * To build a branch, we should allocate blocks for 376 * the indirect blocks(if not allocated yet), and at least 377 * the first direct block of this branch. That's the 378 * minimum number of blocks need to allocate(required) 379 */ 380 target = blks + indirect_blks; 381 382 while (1) { 383 count = target; 384 /* allocating blocks for indirect blocks and direct blocks */ 385 current_block = ext2_new_blocks(inode,goal,&count,err); 386 if (*err) 387 goto failed_out; 388 389 target -= count; 390 /* allocate blocks for indirect blocks */ 391 while (index < indirect_blks && count) { 392 new_blocks[index++] = current_block++; 393 count--; 394 } 395 396 if (count > 0) 397 break; 398 } 399 400 /* save the new block number for the first direct block */ 401 new_blocks[index] = current_block; 402 403 /* total number of blocks allocated for direct blocks */ 404 ret = count; 405 *err = 0; 406 return ret; 407 failed_out: 408 for (i = 0; i <index; i++) 409 ext2_free_blocks(inode, new_blocks[i], 1); 410 return ret; 411 } 412 413 /** 414 * ext2_alloc_branch - allocate and set up a chain of blocks. 415 * @inode: owner 416 * @num: depth of the chain (number of blocks to allocate) 417 * @offsets: offsets (in the blocks) to store the pointers to next. 418 * @branch: place to store the chain in. 419 * 420 * This function allocates @num blocks, zeroes out all but the last one, 421 * links them into chain and (if we are synchronous) writes them to disk. 422 * In other words, it prepares a branch that can be spliced onto the 423 * inode. It stores the information about that chain in the branch[], in 424 * the same format as ext2_get_branch() would do. We are calling it after 425 * we had read the existing part of chain and partial points to the last 426 * triple of that (one with zero ->key). Upon the exit we have the same 427 * picture as after the successful ext2_get_block(), excpet that in one 428 * place chain is disconnected - *branch->p is still zero (we did not 429 * set the last link), but branch->key contains the number that should 430 * be placed into *branch->p to fill that gap. 431 * 432 * If allocation fails we free all blocks we've allocated (and forget 433 * their buffer_heads) and return the error value the from failed 434 * ext2_alloc_block() (normally -ENOSPC). Otherwise we set the chain 435 * as described above and return 0. 436 */ 437 438 static int ext2_alloc_branch(struct inode *inode, 439 int indirect_blks, int *blks, ext2_fsblk_t goal, 440 int *offsets, Indirect *branch) 441 { 442 int blocksize = inode->i_sb->s_blocksize; 443 int i, n = 0; 444 int err = 0; 445 struct buffer_head *bh; 446 int num; 447 ext2_fsblk_t new_blocks[4]; 448 ext2_fsblk_t current_block; 449 450 num = ext2_alloc_blocks(inode, goal, indirect_blks, 451 *blks, new_blocks, &err); 452 if (err) 453 return err; 454 455 branch[0].key = cpu_to_le32(new_blocks[0]); 456 /* 457 * metadata blocks and data blocks are allocated. 458 */ 459 for (n = 1; n <= indirect_blks; n++) { 460 /* 461 * Get buffer_head for parent block, zero it out 462 * and set the pointer to new one, then send 463 * parent to disk. 464 */ 465 bh = sb_getblk(inode->i_sb, new_blocks[n-1]); 466 branch[n].bh = bh; 467 lock_buffer(bh); 468 memset(bh->b_data, 0, blocksize); 469 branch[n].p = (__le32 *) bh->b_data + offsets[n]; 470 branch[n].key = cpu_to_le32(new_blocks[n]); 471 *branch[n].p = branch[n].key; 472 if ( n == indirect_blks) { 473 current_block = new_blocks[n]; 474 /* 475 * End of chain, update the last new metablock of 476 * the chain to point to the new allocated 477 * data blocks numbers 478 */ 479 for (i=1; i < num; i++) 480 *(branch[n].p + i) = cpu_to_le32(++current_block); 481 } 482 set_buffer_uptodate(bh); 483 unlock_buffer(bh); 484 mark_buffer_dirty_inode(bh, inode); 485 /* We used to sync bh here if IS_SYNC(inode). 486 * But we now rely upon generic_osync_inode() 487 * and b_inode_buffers. But not for directories. 488 */ 489 if (S_ISDIR(inode->i_mode) && IS_DIRSYNC(inode)) 490 sync_dirty_buffer(bh); 491 } 492 *blks = num; 493 return err; 494 } 495 496 /** 497 * ext2_splice_branch - splice the allocated branch onto inode. 498 * @inode: owner 499 * @block: (logical) number of block we are adding 500 * @chain: chain of indirect blocks (with a missing link - see 501 * ext2_alloc_branch) 502 * @where: location of missing link 503 * @num: number of indirect blocks we are adding 504 * @blks: number of direct blocks we are adding 505 * 506 * This function fills the missing link and does all housekeeping needed in 507 * inode (->i_blocks, etc.). In case of success we end up with the full 508 * chain to new block and return 0. 509 */ 510 static void ext2_splice_branch(struct inode *inode, 511 long block, Indirect *where, int num, int blks) 512 { 513 int i; 514 struct ext2_block_alloc_info *block_i; 515 ext2_fsblk_t current_block; 516 517 block_i = EXT2_I(inode)->i_block_alloc_info; 518 519 /* XXX LOCKING probably should have i_meta_lock ?*/ 520 /* That's it */ 521 522 *where->p = where->key; 523 524 /* 525 * Update the host buffer_head or inode to point to more just allocated 526 * direct blocks blocks 527 */ 528 if (num == 0 && blks > 1) { 529 current_block = le32_to_cpu(where->key) + 1; 530 for (i = 1; i < blks; i++) 531 *(where->p + i ) = cpu_to_le32(current_block++); 532 } 533 534 /* 535 * update the most recently allocated logical & physical block 536 * in i_block_alloc_info, to assist find the proper goal block for next 537 * allocation 538 */ 539 if (block_i) { 540 block_i->last_alloc_logical_block = block + blks - 1; 541 block_i->last_alloc_physical_block = 542 le32_to_cpu(where[num].key) + blks - 1; 543 } 544 545 /* We are done with atomic stuff, now do the rest of housekeeping */ 546 547 /* had we spliced it onto indirect block? */ 548 if (where->bh) 549 mark_buffer_dirty_inode(where->bh, inode); 550 551 inode->i_ctime = CURRENT_TIME_SEC; 552 mark_inode_dirty(inode); 553 } 554 555 /* 556 * Allocation strategy is simple: if we have to allocate something, we will 557 * have to go the whole way to leaf. So let's do it before attaching anything 558 * to tree, set linkage between the newborn blocks, write them if sync is 559 * required, recheck the path, free and repeat if check fails, otherwise 560 * set the last missing link (that will protect us from any truncate-generated 561 * removals - all blocks on the path are immune now) and possibly force the 562 * write on the parent block. 563 * That has a nice additional property: no special recovery from the failed 564 * allocations is needed - we simply release blocks and do not touch anything 565 * reachable from inode. 566 * 567 * `handle' can be NULL if create == 0. 568 * 569 * return > 0, # of blocks mapped or allocated. 570 * return = 0, if plain lookup failed. 571 * return < 0, error case. 572 */ 573 static int ext2_get_blocks(struct inode *inode, 574 sector_t iblock, unsigned long maxblocks, 575 struct buffer_head *bh_result, 576 int create) 577 { 578 int err = -EIO; 579 int offsets[4]; 580 Indirect chain[4]; 581 Indirect *partial; 582 ext2_fsblk_t goal; 583 int indirect_blks; 584 int blocks_to_boundary = 0; 585 int depth; 586 struct ext2_inode_info *ei = EXT2_I(inode); 587 int count = 0; 588 ext2_fsblk_t first_block = 0; 589 590 depth = ext2_block_to_path(inode,iblock,offsets,&blocks_to_boundary); 591 592 if (depth == 0) 593 return (err); 594 reread: 595 partial = ext2_get_branch(inode, depth, offsets, chain, &err); 596 597 /* Simplest case - block found, no allocation needed */ 598 if (!partial) { 599 first_block = le32_to_cpu(chain[depth - 1].key); 600 clear_buffer_new(bh_result); /* What's this do? */ 601 count++; 602 /*map more blocks*/ 603 while (count < maxblocks && count <= blocks_to_boundary) { 604 ext2_fsblk_t blk; 605 606 if (!verify_chain(chain, partial)) { 607 /* 608 * Indirect block might be removed by 609 * truncate while we were reading it. 610 * Handling of that case: forget what we've 611 * got now, go to reread. 612 */ 613 count = 0; 614 goto changed; 615 } 616 blk = le32_to_cpu(*(chain[depth-1].p + count)); 617 if (blk == first_block + count) 618 count++; 619 else 620 break; 621 } 622 goto got_it; 623 } 624 625 /* Next simple case - plain lookup or failed read of indirect block */ 626 if (!create || err == -EIO) 627 goto cleanup; 628 629 mutex_lock(&ei->truncate_mutex); 630 631 /* 632 * Okay, we need to do block allocation. Lazily initialize the block 633 * allocation info here if necessary 634 */ 635 if (S_ISREG(inode->i_mode) && (!ei->i_block_alloc_info)) 636 ext2_init_block_alloc_info(inode); 637 638 goal = ext2_find_goal(inode, iblock, partial); 639 640 /* the number of blocks need to allocate for [d,t]indirect blocks */ 641 indirect_blks = (chain + depth) - partial - 1; 642 /* 643 * Next look up the indirect map to count the totoal number of 644 * direct blocks to allocate for this branch. 645 */ 646 count = ext2_blks_to_allocate(partial, indirect_blks, 647 maxblocks, blocks_to_boundary); 648 /* 649 * XXX ???? Block out ext2_truncate while we alter the tree 650 */ 651 err = ext2_alloc_branch(inode, indirect_blks, &count, goal, 652 offsets + (partial - chain), partial); 653 654 if (err) { 655 mutex_unlock(&ei->truncate_mutex); 656 goto cleanup; 657 } 658 659 if (ext2_use_xip(inode->i_sb)) { 660 /* 661 * we need to clear the block 662 */ 663 err = ext2_clear_xip_target (inode, 664 le32_to_cpu(chain[depth-1].key)); 665 if (err) { 666 mutex_unlock(&ei->truncate_mutex); 667 goto cleanup; 668 } 669 } 670 671 ext2_splice_branch(inode, iblock, partial, indirect_blks, count); 672 mutex_unlock(&ei->truncate_mutex); 673 set_buffer_new(bh_result); 674 got_it: 675 map_bh(bh_result, inode->i_sb, le32_to_cpu(chain[depth-1].key)); 676 if (count > blocks_to_boundary) 677 set_buffer_boundary(bh_result); 678 err = count; 679 /* Clean up and exit */ 680 partial = chain + depth - 1; /* the whole chain */ 681 cleanup: 682 while (partial > chain) { 683 brelse(partial->bh); 684 partial--; 685 } 686 return err; 687 changed: 688 while (partial > chain) { 689 brelse(partial->bh); 690 partial--; 691 } 692 goto reread; 693 } 694 695 int ext2_get_block(struct inode *inode, sector_t iblock, struct buffer_head *bh_result, int create) 696 { 697 unsigned max_blocks = bh_result->b_size >> inode->i_blkbits; 698 int ret = ext2_get_blocks(inode, iblock, max_blocks, 699 bh_result, create); 700 if (ret > 0) { 701 bh_result->b_size = (ret << inode->i_blkbits); 702 ret = 0; 703 } 704 return ret; 705 706 } 707 708 static int ext2_writepage(struct page *page, struct writeback_control *wbc) 709 { 710 return block_write_full_page(page, ext2_get_block, wbc); 711 } 712 713 static int ext2_readpage(struct file *file, struct page *page) 714 { 715 return mpage_readpage(page, ext2_get_block); 716 } 717 718 static int 719 ext2_readpages(struct file *file, struct address_space *mapping, 720 struct list_head *pages, unsigned nr_pages) 721 { 722 return mpage_readpages(mapping, pages, nr_pages, ext2_get_block); 723 } 724 725 int __ext2_write_begin(struct file *file, struct address_space *mapping, 726 loff_t pos, unsigned len, unsigned flags, 727 struct page **pagep, void **fsdata) 728 { 729 return block_write_begin(file, mapping, pos, len, flags, pagep, fsdata, 730 ext2_get_block); 731 } 732 733 static int 734 ext2_write_begin(struct file *file, struct address_space *mapping, 735 loff_t pos, unsigned len, unsigned flags, 736 struct page **pagep, void **fsdata) 737 { 738 *pagep = NULL; 739 return __ext2_write_begin(file, mapping, pos, len, flags, pagep,fsdata); 740 } 741 742 static int 743 ext2_nobh_write_begin(struct file *file, struct address_space *mapping, 744 loff_t pos, unsigned len, unsigned flags, 745 struct page **pagep, void **fsdata) 746 { 747 /* 748 * Dir-in-pagecache still uses ext2_write_begin. Would have to rework 749 * directory handling code to pass around offsets rather than struct 750 * pages in order to make this work easily. 751 */ 752 return nobh_write_begin(file, mapping, pos, len, flags, pagep, fsdata, 753 ext2_get_block); 754 } 755 756 static int ext2_nobh_writepage(struct page *page, 757 struct writeback_control *wbc) 758 { 759 return nobh_writepage(page, ext2_get_block, wbc); 760 } 761 762 static sector_t ext2_bmap(struct address_space *mapping, sector_t block) 763 { 764 return generic_block_bmap(mapping,block,ext2_get_block); 765 } 766 767 static ssize_t 768 ext2_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov, 769 loff_t offset, unsigned long nr_segs) 770 { 771 struct file *file = iocb->ki_filp; 772 struct inode *inode = file->f_mapping->host; 773 774 return blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev, iov, 775 offset, nr_segs, ext2_get_block, NULL); 776 } 777 778 static int 779 ext2_writepages(struct address_space *mapping, struct writeback_control *wbc) 780 { 781 return mpage_writepages(mapping, wbc, ext2_get_block); 782 } 783 784 const struct address_space_operations ext2_aops = { 785 .readpage = ext2_readpage, 786 .readpages = ext2_readpages, 787 .writepage = ext2_writepage, 788 .sync_page = block_sync_page, 789 .write_begin = ext2_write_begin, 790 .write_end = generic_write_end, 791 .bmap = ext2_bmap, 792 .direct_IO = ext2_direct_IO, 793 .writepages = ext2_writepages, 794 .migratepage = buffer_migrate_page, 795 }; 796 797 const struct address_space_operations ext2_aops_xip = { 798 .bmap = ext2_bmap, 799 .get_xip_page = ext2_get_xip_page, 800 }; 801 802 const struct address_space_operations ext2_nobh_aops = { 803 .readpage = ext2_readpage, 804 .readpages = ext2_readpages, 805 .writepage = ext2_nobh_writepage, 806 .sync_page = block_sync_page, 807 .write_begin = ext2_nobh_write_begin, 808 .write_end = nobh_write_end, 809 .bmap = ext2_bmap, 810 .direct_IO = ext2_direct_IO, 811 .writepages = ext2_writepages, 812 .migratepage = buffer_migrate_page, 813 }; 814 815 /* 816 * Probably it should be a library function... search for first non-zero word 817 * or memcmp with zero_page, whatever is better for particular architecture. 818 * Linus? 819 */ 820 static inline int all_zeroes(__le32 *p, __le32 *q) 821 { 822 while (p < q) 823 if (*p++) 824 return 0; 825 return 1; 826 } 827 828 /** 829 * ext2_find_shared - find the indirect blocks for partial truncation. 830 * @inode: inode in question 831 * @depth: depth of the affected branch 832 * @offsets: offsets of pointers in that branch (see ext2_block_to_path) 833 * @chain: place to store the pointers to partial indirect blocks 834 * @top: place to the (detached) top of branch 835 * 836 * This is a helper function used by ext2_truncate(). 837 * 838 * When we do truncate() we may have to clean the ends of several indirect 839 * blocks but leave the blocks themselves alive. Block is partially 840 * truncated if some data below the new i_size is refered from it (and 841 * it is on the path to the first completely truncated data block, indeed). 842 * We have to free the top of that path along with everything to the right 843 * of the path. Since no allocation past the truncation point is possible 844 * until ext2_truncate() finishes, we may safely do the latter, but top 845 * of branch may require special attention - pageout below the truncation 846 * point might try to populate it. 847 * 848 * We atomically detach the top of branch from the tree, store the block 849 * number of its root in *@top, pointers to buffer_heads of partially 850 * truncated blocks - in @chain[].bh and pointers to their last elements 851 * that should not be removed - in @chain[].p. Return value is the pointer 852 * to last filled element of @chain. 853 * 854 * The work left to caller to do the actual freeing of subtrees: 855 * a) free the subtree starting from *@top 856 * b) free the subtrees whose roots are stored in 857 * (@chain[i].p+1 .. end of @chain[i].bh->b_data) 858 * c) free the subtrees growing from the inode past the @chain[0].p 859 * (no partially truncated stuff there). 860 */ 861 862 static Indirect *ext2_find_shared(struct inode *inode, 863 int depth, 864 int offsets[4], 865 Indirect chain[4], 866 __le32 *top) 867 { 868 Indirect *partial, *p; 869 int k, err; 870 871 *top = 0; 872 for (k = depth; k > 1 && !offsets[k-1]; k--) 873 ; 874 partial = ext2_get_branch(inode, k, offsets, chain, &err); 875 if (!partial) 876 partial = chain + k-1; 877 /* 878 * If the branch acquired continuation since we've looked at it - 879 * fine, it should all survive and (new) top doesn't belong to us. 880 */ 881 write_lock(&EXT2_I(inode)->i_meta_lock); 882 if (!partial->key && *partial->p) { 883 write_unlock(&EXT2_I(inode)->i_meta_lock); 884 goto no_top; 885 } 886 for (p=partial; p>chain && all_zeroes((__le32*)p->bh->b_data,p->p); p--) 887 ; 888 /* 889 * OK, we've found the last block that must survive. The rest of our 890 * branch should be detached before unlocking. However, if that rest 891 * of branch is all ours and does not grow immediately from the inode 892 * it's easier to cheat and just decrement partial->p. 893 */ 894 if (p == chain + k - 1 && p > chain) { 895 p->p--; 896 } else { 897 *top = *p->p; 898 *p->p = 0; 899 } 900 write_unlock(&EXT2_I(inode)->i_meta_lock); 901 902 while(partial > p) 903 { 904 brelse(partial->bh); 905 partial--; 906 } 907 no_top: 908 return partial; 909 } 910 911 /** 912 * ext2_free_data - free a list of data blocks 913 * @inode: inode we are dealing with 914 * @p: array of block numbers 915 * @q: points immediately past the end of array 916 * 917 * We are freeing all blocks refered from that array (numbers are 918 * stored as little-endian 32-bit) and updating @inode->i_blocks 919 * appropriately. 920 */ 921 static inline void ext2_free_data(struct inode *inode, __le32 *p, __le32 *q) 922 { 923 unsigned long block_to_free = 0, count = 0; 924 unsigned long nr; 925 926 for ( ; p < q ; p++) { 927 nr = le32_to_cpu(*p); 928 if (nr) { 929 *p = 0; 930 /* accumulate blocks to free if they're contiguous */ 931 if (count == 0) 932 goto free_this; 933 else if (block_to_free == nr - count) 934 count++; 935 else { 936 mark_inode_dirty(inode); 937 ext2_free_blocks (inode, block_to_free, count); 938 free_this: 939 block_to_free = nr; 940 count = 1; 941 } 942 } 943 } 944 if (count > 0) { 945 mark_inode_dirty(inode); 946 ext2_free_blocks (inode, block_to_free, count); 947 } 948 } 949 950 /** 951 * ext2_free_branches - free an array of branches 952 * @inode: inode we are dealing with 953 * @p: array of block numbers 954 * @q: pointer immediately past the end of array 955 * @depth: depth of the branches to free 956 * 957 * We are freeing all blocks refered from these branches (numbers are 958 * stored as little-endian 32-bit) and updating @inode->i_blocks 959 * appropriately. 960 */ 961 static void ext2_free_branches(struct inode *inode, __le32 *p, __le32 *q, int depth) 962 { 963 struct buffer_head * bh; 964 unsigned long nr; 965 966 if (depth--) { 967 int addr_per_block = EXT2_ADDR_PER_BLOCK(inode->i_sb); 968 for ( ; p < q ; p++) { 969 nr = le32_to_cpu(*p); 970 if (!nr) 971 continue; 972 *p = 0; 973 bh = sb_bread(inode->i_sb, nr); 974 /* 975 * A read failure? Report error and clear slot 976 * (should be rare). 977 */ 978 if (!bh) { 979 ext2_error(inode->i_sb, "ext2_free_branches", 980 "Read failure, inode=%ld, block=%ld", 981 inode->i_ino, nr); 982 continue; 983 } 984 ext2_free_branches(inode, 985 (__le32*)bh->b_data, 986 (__le32*)bh->b_data + addr_per_block, 987 depth); 988 bforget(bh); 989 ext2_free_blocks(inode, nr, 1); 990 mark_inode_dirty(inode); 991 } 992 } else 993 ext2_free_data(inode, p, q); 994 } 995 996 void ext2_truncate(struct inode *inode) 997 { 998 __le32 *i_data = EXT2_I(inode)->i_data; 999 struct ext2_inode_info *ei = EXT2_I(inode); 1000 int addr_per_block = EXT2_ADDR_PER_BLOCK(inode->i_sb); 1001 int offsets[4]; 1002 Indirect chain[4]; 1003 Indirect *partial; 1004 __le32 nr = 0; 1005 int n; 1006 long iblock; 1007 unsigned blocksize; 1008 1009 if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || 1010 S_ISLNK(inode->i_mode))) 1011 return; 1012 if (ext2_inode_is_fast_symlink(inode)) 1013 return; 1014 if (IS_APPEND(inode) || IS_IMMUTABLE(inode)) 1015 return; 1016 1017 blocksize = inode->i_sb->s_blocksize; 1018 iblock = (inode->i_size + blocksize-1) 1019 >> EXT2_BLOCK_SIZE_BITS(inode->i_sb); 1020 1021 if (mapping_is_xip(inode->i_mapping)) 1022 xip_truncate_page(inode->i_mapping, inode->i_size); 1023 else if (test_opt(inode->i_sb, NOBH)) 1024 nobh_truncate_page(inode->i_mapping, 1025 inode->i_size, ext2_get_block); 1026 else 1027 block_truncate_page(inode->i_mapping, 1028 inode->i_size, ext2_get_block); 1029 1030 n = ext2_block_to_path(inode, iblock, offsets, NULL); 1031 if (n == 0) 1032 return; 1033 1034 /* 1035 * From here we block out all ext2_get_block() callers who want to 1036 * modify the block allocation tree. 1037 */ 1038 mutex_lock(&ei->truncate_mutex); 1039 1040 if (n == 1) { 1041 ext2_free_data(inode, i_data+offsets[0], 1042 i_data + EXT2_NDIR_BLOCKS); 1043 goto do_indirects; 1044 } 1045 1046 partial = ext2_find_shared(inode, n, offsets, chain, &nr); 1047 /* Kill the top of shared branch (already detached) */ 1048 if (nr) { 1049 if (partial == chain) 1050 mark_inode_dirty(inode); 1051 else 1052 mark_buffer_dirty_inode(partial->bh, inode); 1053 ext2_free_branches(inode, &nr, &nr+1, (chain+n-1) - partial); 1054 } 1055 /* Clear the ends of indirect blocks on the shared branch */ 1056 while (partial > chain) { 1057 ext2_free_branches(inode, 1058 partial->p + 1, 1059 (__le32*)partial->bh->b_data+addr_per_block, 1060 (chain+n-1) - partial); 1061 mark_buffer_dirty_inode(partial->bh, inode); 1062 brelse (partial->bh); 1063 partial--; 1064 } 1065 do_indirects: 1066 /* Kill the remaining (whole) subtrees */ 1067 switch (offsets[0]) { 1068 default: 1069 nr = i_data[EXT2_IND_BLOCK]; 1070 if (nr) { 1071 i_data[EXT2_IND_BLOCK] = 0; 1072 mark_inode_dirty(inode); 1073 ext2_free_branches(inode, &nr, &nr+1, 1); 1074 } 1075 case EXT2_IND_BLOCK: 1076 nr = i_data[EXT2_DIND_BLOCK]; 1077 if (nr) { 1078 i_data[EXT2_DIND_BLOCK] = 0; 1079 mark_inode_dirty(inode); 1080 ext2_free_branches(inode, &nr, &nr+1, 2); 1081 } 1082 case EXT2_DIND_BLOCK: 1083 nr = i_data[EXT2_TIND_BLOCK]; 1084 if (nr) { 1085 i_data[EXT2_TIND_BLOCK] = 0; 1086 mark_inode_dirty(inode); 1087 ext2_free_branches(inode, &nr, &nr+1, 3); 1088 } 1089 case EXT2_TIND_BLOCK: 1090 ; 1091 } 1092 1093 ext2_discard_reservation(inode); 1094 1095 mutex_unlock(&ei->truncate_mutex); 1096 inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC; 1097 if (inode_needs_sync(inode)) { 1098 sync_mapping_buffers(inode->i_mapping); 1099 ext2_sync_inode (inode); 1100 } else { 1101 mark_inode_dirty(inode); 1102 } 1103 } 1104 1105 static struct ext2_inode *ext2_get_inode(struct super_block *sb, ino_t ino, 1106 struct buffer_head **p) 1107 { 1108 struct buffer_head * bh; 1109 unsigned long block_group; 1110 unsigned long block; 1111 unsigned long offset; 1112 struct ext2_group_desc * gdp; 1113 1114 *p = NULL; 1115 if ((ino != EXT2_ROOT_INO && ino < EXT2_FIRST_INO(sb)) || 1116 ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count)) 1117 goto Einval; 1118 1119 block_group = (ino - 1) / EXT2_INODES_PER_GROUP(sb); 1120 gdp = ext2_get_group_desc(sb, block_group, NULL); 1121 if (!gdp) 1122 goto Egdp; 1123 /* 1124 * Figure out the offset within the block group inode table 1125 */ 1126 offset = ((ino - 1) % EXT2_INODES_PER_GROUP(sb)) * EXT2_INODE_SIZE(sb); 1127 block = le32_to_cpu(gdp->bg_inode_table) + 1128 (offset >> EXT2_BLOCK_SIZE_BITS(sb)); 1129 if (!(bh = sb_bread(sb, block))) 1130 goto Eio; 1131 1132 *p = bh; 1133 offset &= (EXT2_BLOCK_SIZE(sb) - 1); 1134 return (struct ext2_inode *) (bh->b_data + offset); 1135 1136 Einval: 1137 ext2_error(sb, "ext2_get_inode", "bad inode number: %lu", 1138 (unsigned long) ino); 1139 return ERR_PTR(-EINVAL); 1140 Eio: 1141 ext2_error(sb, "ext2_get_inode", 1142 "unable to read inode block - inode=%lu, block=%lu", 1143 (unsigned long) ino, block); 1144 Egdp: 1145 return ERR_PTR(-EIO); 1146 } 1147 1148 void ext2_set_inode_flags(struct inode *inode) 1149 { 1150 unsigned int flags = EXT2_I(inode)->i_flags; 1151 1152 inode->i_flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC); 1153 if (flags & EXT2_SYNC_FL) 1154 inode->i_flags |= S_SYNC; 1155 if (flags & EXT2_APPEND_FL) 1156 inode->i_flags |= S_APPEND; 1157 if (flags & EXT2_IMMUTABLE_FL) 1158 inode->i_flags |= S_IMMUTABLE; 1159 if (flags & EXT2_NOATIME_FL) 1160 inode->i_flags |= S_NOATIME; 1161 if (flags & EXT2_DIRSYNC_FL) 1162 inode->i_flags |= S_DIRSYNC; 1163 } 1164 1165 /* Propagate flags from i_flags to EXT2_I(inode)->i_flags */ 1166 void ext2_get_inode_flags(struct ext2_inode_info *ei) 1167 { 1168 unsigned int flags = ei->vfs_inode.i_flags; 1169 1170 ei->i_flags &= ~(EXT2_SYNC_FL|EXT2_APPEND_FL| 1171 EXT2_IMMUTABLE_FL|EXT2_NOATIME_FL|EXT2_DIRSYNC_FL); 1172 if (flags & S_SYNC) 1173 ei->i_flags |= EXT2_SYNC_FL; 1174 if (flags & S_APPEND) 1175 ei->i_flags |= EXT2_APPEND_FL; 1176 if (flags & S_IMMUTABLE) 1177 ei->i_flags |= EXT2_IMMUTABLE_FL; 1178 if (flags & S_NOATIME) 1179 ei->i_flags |= EXT2_NOATIME_FL; 1180 if (flags & S_DIRSYNC) 1181 ei->i_flags |= EXT2_DIRSYNC_FL; 1182 } 1183 1184 struct inode *ext2_iget (struct super_block *sb, unsigned long ino) 1185 { 1186 struct ext2_inode_info *ei; 1187 struct buffer_head * bh; 1188 struct ext2_inode *raw_inode; 1189 struct inode *inode; 1190 long ret = -EIO; 1191 int n; 1192 1193 inode = iget_locked(sb, ino); 1194 if (!inode) 1195 return ERR_PTR(-ENOMEM); 1196 if (!(inode->i_state & I_NEW)) 1197 return inode; 1198 1199 ei = EXT2_I(inode); 1200 #ifdef CONFIG_EXT2_FS_POSIX_ACL 1201 ei->i_acl = EXT2_ACL_NOT_CACHED; 1202 ei->i_default_acl = EXT2_ACL_NOT_CACHED; 1203 #endif 1204 ei->i_block_alloc_info = NULL; 1205 1206 raw_inode = ext2_get_inode(inode->i_sb, ino, &bh); 1207 if (IS_ERR(raw_inode)) { 1208 ret = PTR_ERR(raw_inode); 1209 goto bad_inode; 1210 } 1211 1212 inode->i_mode = le16_to_cpu(raw_inode->i_mode); 1213 inode->i_uid = (uid_t)le16_to_cpu(raw_inode->i_uid_low); 1214 inode->i_gid = (gid_t)le16_to_cpu(raw_inode->i_gid_low); 1215 if (!(test_opt (inode->i_sb, NO_UID32))) { 1216 inode->i_uid |= le16_to_cpu(raw_inode->i_uid_high) << 16; 1217 inode->i_gid |= le16_to_cpu(raw_inode->i_gid_high) << 16; 1218 } 1219 inode->i_nlink = le16_to_cpu(raw_inode->i_links_count); 1220 inode->i_size = le32_to_cpu(raw_inode->i_size); 1221 inode->i_atime.tv_sec = (signed)le32_to_cpu(raw_inode->i_atime); 1222 inode->i_ctime.tv_sec = (signed)le32_to_cpu(raw_inode->i_ctime); 1223 inode->i_mtime.tv_sec = (signed)le32_to_cpu(raw_inode->i_mtime); 1224 inode->i_atime.tv_nsec = inode->i_mtime.tv_nsec = inode->i_ctime.tv_nsec = 0; 1225 ei->i_dtime = le32_to_cpu(raw_inode->i_dtime); 1226 /* We now have enough fields to check if the inode was active or not. 1227 * This is needed because nfsd might try to access dead inodes 1228 * the test is that same one that e2fsck uses 1229 * NeilBrown 1999oct15 1230 */ 1231 if (inode->i_nlink == 0 && (inode->i_mode == 0 || ei->i_dtime)) { 1232 /* this inode is deleted */ 1233 brelse (bh); 1234 ret = -ESTALE; 1235 goto bad_inode; 1236 } 1237 inode->i_blocks = le32_to_cpu(raw_inode->i_blocks); 1238 ei->i_flags = le32_to_cpu(raw_inode->i_flags); 1239 ei->i_faddr = le32_to_cpu(raw_inode->i_faddr); 1240 ei->i_frag_no = raw_inode->i_frag; 1241 ei->i_frag_size = raw_inode->i_fsize; 1242 ei->i_file_acl = le32_to_cpu(raw_inode->i_file_acl); 1243 ei->i_dir_acl = 0; 1244 if (S_ISREG(inode->i_mode)) 1245 inode->i_size |= ((__u64)le32_to_cpu(raw_inode->i_size_high)) << 32; 1246 else 1247 ei->i_dir_acl = le32_to_cpu(raw_inode->i_dir_acl); 1248 ei->i_dtime = 0; 1249 inode->i_generation = le32_to_cpu(raw_inode->i_generation); 1250 ei->i_state = 0; 1251 ei->i_block_group = (ino - 1) / EXT2_INODES_PER_GROUP(inode->i_sb); 1252 ei->i_dir_start_lookup = 0; 1253 1254 /* 1255 * NOTE! The in-memory inode i_data array is in little-endian order 1256 * even on big-endian machines: we do NOT byteswap the block numbers! 1257 */ 1258 for (n = 0; n < EXT2_N_BLOCKS; n++) 1259 ei->i_data[n] = raw_inode->i_block[n]; 1260 1261 if (S_ISREG(inode->i_mode)) { 1262 inode->i_op = &ext2_file_inode_operations; 1263 if (ext2_use_xip(inode->i_sb)) { 1264 inode->i_mapping->a_ops = &ext2_aops_xip; 1265 inode->i_fop = &ext2_xip_file_operations; 1266 } else if (test_opt(inode->i_sb, NOBH)) { 1267 inode->i_mapping->a_ops = &ext2_nobh_aops; 1268 inode->i_fop = &ext2_file_operations; 1269 } else { 1270 inode->i_mapping->a_ops = &ext2_aops; 1271 inode->i_fop = &ext2_file_operations; 1272 } 1273 } else if (S_ISDIR(inode->i_mode)) { 1274 inode->i_op = &ext2_dir_inode_operations; 1275 inode->i_fop = &ext2_dir_operations; 1276 if (test_opt(inode->i_sb, NOBH)) 1277 inode->i_mapping->a_ops = &ext2_nobh_aops; 1278 else 1279 inode->i_mapping->a_ops = &ext2_aops; 1280 } else if (S_ISLNK(inode->i_mode)) { 1281 if (ext2_inode_is_fast_symlink(inode)) 1282 inode->i_op = &ext2_fast_symlink_inode_operations; 1283 else { 1284 inode->i_op = &ext2_symlink_inode_operations; 1285 if (test_opt(inode->i_sb, NOBH)) 1286 inode->i_mapping->a_ops = &ext2_nobh_aops; 1287 else 1288 inode->i_mapping->a_ops = &ext2_aops; 1289 } 1290 } else { 1291 inode->i_op = &ext2_special_inode_operations; 1292 if (raw_inode->i_block[0]) 1293 init_special_inode(inode, inode->i_mode, 1294 old_decode_dev(le32_to_cpu(raw_inode->i_block[0]))); 1295 else 1296 init_special_inode(inode, inode->i_mode, 1297 new_decode_dev(le32_to_cpu(raw_inode->i_block[1]))); 1298 } 1299 brelse (bh); 1300 ext2_set_inode_flags(inode); 1301 unlock_new_inode(inode); 1302 return inode; 1303 1304 bad_inode: 1305 iget_failed(inode); 1306 return ERR_PTR(ret); 1307 } 1308 1309 static int ext2_update_inode(struct inode * inode, int do_sync) 1310 { 1311 struct ext2_inode_info *ei = EXT2_I(inode); 1312 struct super_block *sb = inode->i_sb; 1313 ino_t ino = inode->i_ino; 1314 uid_t uid = inode->i_uid; 1315 gid_t gid = inode->i_gid; 1316 struct buffer_head * bh; 1317 struct ext2_inode * raw_inode = ext2_get_inode(sb, ino, &bh); 1318 int n; 1319 int err = 0; 1320 1321 if (IS_ERR(raw_inode)) 1322 return -EIO; 1323 1324 /* For fields not not tracking in the in-memory inode, 1325 * initialise them to zero for new inodes. */ 1326 if (ei->i_state & EXT2_STATE_NEW) 1327 memset(raw_inode, 0, EXT2_SB(sb)->s_inode_size); 1328 1329 ext2_get_inode_flags(ei); 1330 raw_inode->i_mode = cpu_to_le16(inode->i_mode); 1331 if (!(test_opt(sb, NO_UID32))) { 1332 raw_inode->i_uid_low = cpu_to_le16(low_16_bits(uid)); 1333 raw_inode->i_gid_low = cpu_to_le16(low_16_bits(gid)); 1334 /* 1335 * Fix up interoperability with old kernels. Otherwise, old inodes get 1336 * re-used with the upper 16 bits of the uid/gid intact 1337 */ 1338 if (!ei->i_dtime) { 1339 raw_inode->i_uid_high = cpu_to_le16(high_16_bits(uid)); 1340 raw_inode->i_gid_high = cpu_to_le16(high_16_bits(gid)); 1341 } else { 1342 raw_inode->i_uid_high = 0; 1343 raw_inode->i_gid_high = 0; 1344 } 1345 } else { 1346 raw_inode->i_uid_low = cpu_to_le16(fs_high2lowuid(uid)); 1347 raw_inode->i_gid_low = cpu_to_le16(fs_high2lowgid(gid)); 1348 raw_inode->i_uid_high = 0; 1349 raw_inode->i_gid_high = 0; 1350 } 1351 raw_inode->i_links_count = cpu_to_le16(inode->i_nlink); 1352 raw_inode->i_size = cpu_to_le32(inode->i_size); 1353 raw_inode->i_atime = cpu_to_le32(inode->i_atime.tv_sec); 1354 raw_inode->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec); 1355 raw_inode->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec); 1356 1357 raw_inode->i_blocks = cpu_to_le32(inode->i_blocks); 1358 raw_inode->i_dtime = cpu_to_le32(ei->i_dtime); 1359 raw_inode->i_flags = cpu_to_le32(ei->i_flags); 1360 raw_inode->i_faddr = cpu_to_le32(ei->i_faddr); 1361 raw_inode->i_frag = ei->i_frag_no; 1362 raw_inode->i_fsize = ei->i_frag_size; 1363 raw_inode->i_file_acl = cpu_to_le32(ei->i_file_acl); 1364 if (!S_ISREG(inode->i_mode)) 1365 raw_inode->i_dir_acl = cpu_to_le32(ei->i_dir_acl); 1366 else { 1367 raw_inode->i_size_high = cpu_to_le32(inode->i_size >> 32); 1368 if (inode->i_size > 0x7fffffffULL) { 1369 if (!EXT2_HAS_RO_COMPAT_FEATURE(sb, 1370 EXT2_FEATURE_RO_COMPAT_LARGE_FILE) || 1371 EXT2_SB(sb)->s_es->s_rev_level == 1372 cpu_to_le32(EXT2_GOOD_OLD_REV)) { 1373 /* If this is the first large file 1374 * created, add a flag to the superblock. 1375 */ 1376 lock_kernel(); 1377 ext2_update_dynamic_rev(sb); 1378 EXT2_SET_RO_COMPAT_FEATURE(sb, 1379 EXT2_FEATURE_RO_COMPAT_LARGE_FILE); 1380 unlock_kernel(); 1381 ext2_write_super(sb); 1382 } 1383 } 1384 } 1385 1386 raw_inode->i_generation = cpu_to_le32(inode->i_generation); 1387 if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) { 1388 if (old_valid_dev(inode->i_rdev)) { 1389 raw_inode->i_block[0] = 1390 cpu_to_le32(old_encode_dev(inode->i_rdev)); 1391 raw_inode->i_block[1] = 0; 1392 } else { 1393 raw_inode->i_block[0] = 0; 1394 raw_inode->i_block[1] = 1395 cpu_to_le32(new_encode_dev(inode->i_rdev)); 1396 raw_inode->i_block[2] = 0; 1397 } 1398 } else for (n = 0; n < EXT2_N_BLOCKS; n++) 1399 raw_inode->i_block[n] = ei->i_data[n]; 1400 mark_buffer_dirty(bh); 1401 if (do_sync) { 1402 sync_dirty_buffer(bh); 1403 if (buffer_req(bh) && !buffer_uptodate(bh)) { 1404 printk ("IO error syncing ext2 inode [%s:%08lx]\n", 1405 sb->s_id, (unsigned long) ino); 1406 err = -EIO; 1407 } 1408 } 1409 ei->i_state &= ~EXT2_STATE_NEW; 1410 brelse (bh); 1411 return err; 1412 } 1413 1414 int ext2_write_inode(struct inode *inode, int wait) 1415 { 1416 return ext2_update_inode(inode, wait); 1417 } 1418 1419 int ext2_sync_inode(struct inode *inode) 1420 { 1421 struct writeback_control wbc = { 1422 .sync_mode = WB_SYNC_ALL, 1423 .nr_to_write = 0, /* sys_fsync did this */ 1424 }; 1425 return sync_inode(inode, &wbc); 1426 } 1427 1428 int ext2_setattr(struct dentry *dentry, struct iattr *iattr) 1429 { 1430 struct inode *inode = dentry->d_inode; 1431 int error; 1432 1433 error = inode_change_ok(inode, iattr); 1434 if (error) 1435 return error; 1436 if ((iattr->ia_valid & ATTR_UID && iattr->ia_uid != inode->i_uid) || 1437 (iattr->ia_valid & ATTR_GID && iattr->ia_gid != inode->i_gid)) { 1438 error = DQUOT_TRANSFER(inode, iattr) ? -EDQUOT : 0; 1439 if (error) 1440 return error; 1441 } 1442 error = inode_setattr(inode, iattr); 1443 if (!error && (iattr->ia_valid & ATTR_MODE)) 1444 error = ext2_acl_chmod(inode); 1445 return error; 1446 } 1447