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 <linux/fiemap.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_update_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 /* 58 * Called at the last iput() if i_nlink is zero. 59 */ 60 void ext2_delete_inode (struct inode * inode) 61 { 62 truncate_inode_pages(&inode->i_data, 0); 63 64 if (is_bad_inode(inode)) 65 goto no_delete; 66 EXT2_I(inode)->i_dtime = get_seconds(); 67 mark_inode_dirty(inode); 68 ext2_update_inode(inode, inode_needs_sync(inode)); 69 70 inode->i_size = 0; 71 if (inode->i_blocks) 72 ext2_truncate (inode); 73 ext2_free_inode (inode); 74 75 return; 76 no_delete: 77 clear_inode(inode); /* We must guarantee clearing of inode... */ 78 } 79 80 typedef struct { 81 __le32 *p; 82 __le32 key; 83 struct buffer_head *bh; 84 } Indirect; 85 86 static inline void add_chain(Indirect *p, struct buffer_head *bh, __le32 *v) 87 { 88 p->key = *(p->p = v); 89 p->bh = bh; 90 } 91 92 static inline int verify_chain(Indirect *from, Indirect *to) 93 { 94 while (from <= to && from->key == *from->p) 95 from++; 96 return (from > to); 97 } 98 99 /** 100 * ext2_block_to_path - parse the block number into array of offsets 101 * @inode: inode in question (we are only interested in its superblock) 102 * @i_block: block number to be parsed 103 * @offsets: array to store the offsets in 104 * @boundary: set this non-zero if the referred-to block is likely to be 105 * followed (on disk) by an indirect block. 106 * To store the locations of file's data ext2 uses a data structure common 107 * for UNIX filesystems - tree of pointers anchored in the inode, with 108 * data blocks at leaves and indirect blocks in intermediate nodes. 109 * This function translates the block number into path in that tree - 110 * return value is the path length and @offsets[n] is the offset of 111 * pointer to (n+1)th node in the nth one. If @block is out of range 112 * (negative or too large) warning is printed and zero returned. 113 * 114 * Note: function doesn't find node addresses, so no IO is needed. All 115 * we need to know is the capacity of indirect blocks (taken from the 116 * inode->i_sb). 117 */ 118 119 /* 120 * Portability note: the last comparison (check that we fit into triple 121 * indirect block) is spelled differently, because otherwise on an 122 * architecture with 32-bit longs and 8Kb pages we might get into trouble 123 * if our filesystem had 8Kb blocks. We might use long long, but that would 124 * kill us on x86. Oh, well, at least the sign propagation does not matter - 125 * i_block would have to be negative in the very beginning, so we would not 126 * get there at all. 127 */ 128 129 static int ext2_block_to_path(struct inode *inode, 130 long i_block, int offsets[4], int *boundary) 131 { 132 int ptrs = EXT2_ADDR_PER_BLOCK(inode->i_sb); 133 int ptrs_bits = EXT2_ADDR_PER_BLOCK_BITS(inode->i_sb); 134 const long direct_blocks = EXT2_NDIR_BLOCKS, 135 indirect_blocks = ptrs, 136 double_blocks = (1 << (ptrs_bits * 2)); 137 int n = 0; 138 int final = 0; 139 140 if (i_block < 0) { 141 ext2_warning (inode->i_sb, "ext2_block_to_path", "block < 0"); 142 } else if (i_block < direct_blocks) { 143 offsets[n++] = i_block; 144 final = direct_blocks; 145 } else if ( (i_block -= direct_blocks) < indirect_blocks) { 146 offsets[n++] = EXT2_IND_BLOCK; 147 offsets[n++] = i_block; 148 final = ptrs; 149 } else if ((i_block -= indirect_blocks) < double_blocks) { 150 offsets[n++] = EXT2_DIND_BLOCK; 151 offsets[n++] = i_block >> ptrs_bits; 152 offsets[n++] = i_block & (ptrs - 1); 153 final = ptrs; 154 } else if (((i_block -= double_blocks) >> (ptrs_bits * 2)) < ptrs) { 155 offsets[n++] = EXT2_TIND_BLOCK; 156 offsets[n++] = i_block >> (ptrs_bits * 2); 157 offsets[n++] = (i_block >> ptrs_bits) & (ptrs - 1); 158 offsets[n++] = i_block & (ptrs - 1); 159 final = ptrs; 160 } else { 161 ext2_warning (inode->i_sb, "ext2_block_to_path", "block > big"); 162 } 163 if (boundary) 164 *boundary = final - 1 - (i_block & (ptrs - 1)); 165 166 return n; 167 } 168 169 /** 170 * ext2_get_branch - read the chain of indirect blocks leading to data 171 * @inode: inode in question 172 * @depth: depth of the chain (1 - direct pointer, etc.) 173 * @offsets: offsets of pointers in inode/indirect blocks 174 * @chain: place to store the result 175 * @err: here we store the error value 176 * 177 * Function fills the array of triples <key, p, bh> and returns %NULL 178 * if everything went OK or the pointer to the last filled triple 179 * (incomplete one) otherwise. Upon the return chain[i].key contains 180 * the number of (i+1)-th block in the chain (as it is stored in memory, 181 * i.e. little-endian 32-bit), chain[i].p contains the address of that 182 * number (it points into struct inode for i==0 and into the bh->b_data 183 * for i>0) and chain[i].bh points to the buffer_head of i-th indirect 184 * block for i>0 and NULL for i==0. In other words, it holds the block 185 * numbers of the chain, addresses they were taken from (and where we can 186 * verify that chain did not change) and buffer_heads hosting these 187 * numbers. 188 * 189 * Function stops when it stumbles upon zero pointer (absent block) 190 * (pointer to last triple returned, *@err == 0) 191 * or when it gets an IO error reading an indirect block 192 * (ditto, *@err == -EIO) 193 * or when it notices that chain had been changed while it was reading 194 * (ditto, *@err == -EAGAIN) 195 * or when it reads all @depth-1 indirect blocks successfully and finds 196 * the whole chain, all way to the data (returns %NULL, *err == 0). 197 */ 198 static Indirect *ext2_get_branch(struct inode *inode, 199 int depth, 200 int *offsets, 201 Indirect chain[4], 202 int *err) 203 { 204 struct super_block *sb = inode->i_sb; 205 Indirect *p = chain; 206 struct buffer_head *bh; 207 208 *err = 0; 209 /* i_data is not going away, no lock needed */ 210 add_chain (chain, NULL, EXT2_I(inode)->i_data + *offsets); 211 if (!p->key) 212 goto no_block; 213 while (--depth) { 214 bh = sb_bread(sb, le32_to_cpu(p->key)); 215 if (!bh) 216 goto failure; 217 read_lock(&EXT2_I(inode)->i_meta_lock); 218 if (!verify_chain(chain, p)) 219 goto changed; 220 add_chain(++p, bh, (__le32*)bh->b_data + *++offsets); 221 read_unlock(&EXT2_I(inode)->i_meta_lock); 222 if (!p->key) 223 goto no_block; 224 } 225 return NULL; 226 227 changed: 228 read_unlock(&EXT2_I(inode)->i_meta_lock); 229 brelse(bh); 230 *err = -EAGAIN; 231 goto no_block; 232 failure: 233 *err = -EIO; 234 no_block: 235 return p; 236 } 237 238 /** 239 * ext2_find_near - find a place for allocation with sufficient locality 240 * @inode: owner 241 * @ind: descriptor of indirect block. 242 * 243 * This function returns the preferred place for block allocation. 244 * It is used when heuristic for sequential allocation fails. 245 * Rules are: 246 * + if there is a block to the left of our position - allocate near it. 247 * + if pointer will live in indirect block - allocate near that block. 248 * + if pointer will live in inode - allocate in the same cylinder group. 249 * 250 * In the latter case we colour the starting block by the callers PID to 251 * prevent it from clashing with concurrent allocations for a different inode 252 * in the same block group. The PID is used here so that functionally related 253 * files will be close-by on-disk. 254 * 255 * Caller must make sure that @ind is valid and will stay that way. 256 */ 257 258 static ext2_fsblk_t ext2_find_near(struct inode *inode, Indirect *ind) 259 { 260 struct ext2_inode_info *ei = EXT2_I(inode); 261 __le32 *start = ind->bh ? (__le32 *) ind->bh->b_data : ei->i_data; 262 __le32 *p; 263 ext2_fsblk_t bg_start; 264 ext2_fsblk_t colour; 265 266 /* Try to find previous block */ 267 for (p = ind->p - 1; p >= start; p--) 268 if (*p) 269 return le32_to_cpu(*p); 270 271 /* No such thing, so let's try location of indirect block */ 272 if (ind->bh) 273 return ind->bh->b_blocknr; 274 275 /* 276 * It is going to be refered from inode itself? OK, just put it into 277 * the same cylinder group then. 278 */ 279 bg_start = ext2_group_first_block_no(inode->i_sb, ei->i_block_group); 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 preferred 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 ext2_fsblk_t 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 int ext2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, 709 u64 start, u64 len) 710 { 711 return generic_block_fiemap(inode, fieinfo, start, len, 712 ext2_get_block); 713 } 714 715 static int ext2_writepage(struct page *page, struct writeback_control *wbc) 716 { 717 return block_write_full_page(page, ext2_get_block, wbc); 718 } 719 720 static int ext2_readpage(struct file *file, struct page *page) 721 { 722 return mpage_readpage(page, ext2_get_block); 723 } 724 725 static int 726 ext2_readpages(struct file *file, struct address_space *mapping, 727 struct list_head *pages, unsigned nr_pages) 728 { 729 return mpage_readpages(mapping, pages, nr_pages, ext2_get_block); 730 } 731 732 int __ext2_write_begin(struct file *file, struct address_space *mapping, 733 loff_t pos, unsigned len, unsigned flags, 734 struct page **pagep, void **fsdata) 735 { 736 return block_write_begin(file, mapping, pos, len, flags, pagep, fsdata, 737 ext2_get_block); 738 } 739 740 static int 741 ext2_write_begin(struct file *file, struct address_space *mapping, 742 loff_t pos, unsigned len, unsigned flags, 743 struct page **pagep, void **fsdata) 744 { 745 *pagep = NULL; 746 return __ext2_write_begin(file, mapping, pos, len, flags, pagep,fsdata); 747 } 748 749 static int 750 ext2_nobh_write_begin(struct file *file, struct address_space *mapping, 751 loff_t pos, unsigned len, unsigned flags, 752 struct page **pagep, void **fsdata) 753 { 754 /* 755 * Dir-in-pagecache still uses ext2_write_begin. Would have to rework 756 * directory handling code to pass around offsets rather than struct 757 * pages in order to make this work easily. 758 */ 759 return nobh_write_begin(file, mapping, pos, len, flags, pagep, fsdata, 760 ext2_get_block); 761 } 762 763 static int ext2_nobh_writepage(struct page *page, 764 struct writeback_control *wbc) 765 { 766 return nobh_writepage(page, ext2_get_block, wbc); 767 } 768 769 static sector_t ext2_bmap(struct address_space *mapping, sector_t block) 770 { 771 return generic_block_bmap(mapping,block,ext2_get_block); 772 } 773 774 static ssize_t 775 ext2_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov, 776 loff_t offset, unsigned long nr_segs) 777 { 778 struct file *file = iocb->ki_filp; 779 struct inode *inode = file->f_mapping->host; 780 781 return blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev, iov, 782 offset, nr_segs, ext2_get_block, NULL); 783 } 784 785 static int 786 ext2_writepages(struct address_space *mapping, struct writeback_control *wbc) 787 { 788 return mpage_writepages(mapping, wbc, ext2_get_block); 789 } 790 791 const struct address_space_operations ext2_aops = { 792 .readpage = ext2_readpage, 793 .readpages = ext2_readpages, 794 .writepage = ext2_writepage, 795 .sync_page = block_sync_page, 796 .write_begin = ext2_write_begin, 797 .write_end = generic_write_end, 798 .bmap = ext2_bmap, 799 .direct_IO = ext2_direct_IO, 800 .writepages = ext2_writepages, 801 .migratepage = buffer_migrate_page, 802 .is_partially_uptodate = block_is_partially_uptodate, 803 }; 804 805 const struct address_space_operations ext2_aops_xip = { 806 .bmap = ext2_bmap, 807 .get_xip_mem = ext2_get_xip_mem, 808 }; 809 810 const struct address_space_operations ext2_nobh_aops = { 811 .readpage = ext2_readpage, 812 .readpages = ext2_readpages, 813 .writepage = ext2_nobh_writepage, 814 .sync_page = block_sync_page, 815 .write_begin = ext2_nobh_write_begin, 816 .write_end = nobh_write_end, 817 .bmap = ext2_bmap, 818 .direct_IO = ext2_direct_IO, 819 .writepages = ext2_writepages, 820 .migratepage = buffer_migrate_page, 821 }; 822 823 /* 824 * Probably it should be a library function... search for first non-zero word 825 * or memcmp with zero_page, whatever is better for particular architecture. 826 * Linus? 827 */ 828 static inline int all_zeroes(__le32 *p, __le32 *q) 829 { 830 while (p < q) 831 if (*p++) 832 return 0; 833 return 1; 834 } 835 836 /** 837 * ext2_find_shared - find the indirect blocks for partial truncation. 838 * @inode: inode in question 839 * @depth: depth of the affected branch 840 * @offsets: offsets of pointers in that branch (see ext2_block_to_path) 841 * @chain: place to store the pointers to partial indirect blocks 842 * @top: place to the (detached) top of branch 843 * 844 * This is a helper function used by ext2_truncate(). 845 * 846 * When we do truncate() we may have to clean the ends of several indirect 847 * blocks but leave the blocks themselves alive. Block is partially 848 * truncated if some data below the new i_size is refered from it (and 849 * it is on the path to the first completely truncated data block, indeed). 850 * We have to free the top of that path along with everything to the right 851 * of the path. Since no allocation past the truncation point is possible 852 * until ext2_truncate() finishes, we may safely do the latter, but top 853 * of branch may require special attention - pageout below the truncation 854 * point might try to populate it. 855 * 856 * We atomically detach the top of branch from the tree, store the block 857 * number of its root in *@top, pointers to buffer_heads of partially 858 * truncated blocks - in @chain[].bh and pointers to their last elements 859 * that should not be removed - in @chain[].p. Return value is the pointer 860 * to last filled element of @chain. 861 * 862 * The work left to caller to do the actual freeing of subtrees: 863 * a) free the subtree starting from *@top 864 * b) free the subtrees whose roots are stored in 865 * (@chain[i].p+1 .. end of @chain[i].bh->b_data) 866 * c) free the subtrees growing from the inode past the @chain[0].p 867 * (no partially truncated stuff there). 868 */ 869 870 static Indirect *ext2_find_shared(struct inode *inode, 871 int depth, 872 int offsets[4], 873 Indirect chain[4], 874 __le32 *top) 875 { 876 Indirect *partial, *p; 877 int k, err; 878 879 *top = 0; 880 for (k = depth; k > 1 && !offsets[k-1]; k--) 881 ; 882 partial = ext2_get_branch(inode, k, offsets, chain, &err); 883 if (!partial) 884 partial = chain + k-1; 885 /* 886 * If the branch acquired continuation since we've looked at it - 887 * fine, it should all survive and (new) top doesn't belong to us. 888 */ 889 write_lock(&EXT2_I(inode)->i_meta_lock); 890 if (!partial->key && *partial->p) { 891 write_unlock(&EXT2_I(inode)->i_meta_lock); 892 goto no_top; 893 } 894 for (p=partial; p>chain && all_zeroes((__le32*)p->bh->b_data,p->p); p--) 895 ; 896 /* 897 * OK, we've found the last block that must survive. The rest of our 898 * branch should be detached before unlocking. However, if that rest 899 * of branch is all ours and does not grow immediately from the inode 900 * it's easier to cheat and just decrement partial->p. 901 */ 902 if (p == chain + k - 1 && p > chain) { 903 p->p--; 904 } else { 905 *top = *p->p; 906 *p->p = 0; 907 } 908 write_unlock(&EXT2_I(inode)->i_meta_lock); 909 910 while(partial > p) 911 { 912 brelse(partial->bh); 913 partial--; 914 } 915 no_top: 916 return partial; 917 } 918 919 /** 920 * ext2_free_data - free a list of data blocks 921 * @inode: inode we are dealing with 922 * @p: array of block numbers 923 * @q: points immediately past the end of array 924 * 925 * We are freeing all blocks refered from that array (numbers are 926 * stored as little-endian 32-bit) and updating @inode->i_blocks 927 * appropriately. 928 */ 929 static inline void ext2_free_data(struct inode *inode, __le32 *p, __le32 *q) 930 { 931 unsigned long block_to_free = 0, count = 0; 932 unsigned long nr; 933 934 for ( ; p < q ; p++) { 935 nr = le32_to_cpu(*p); 936 if (nr) { 937 *p = 0; 938 /* accumulate blocks to free if they're contiguous */ 939 if (count == 0) 940 goto free_this; 941 else if (block_to_free == nr - count) 942 count++; 943 else { 944 mark_inode_dirty(inode); 945 ext2_free_blocks (inode, block_to_free, count); 946 free_this: 947 block_to_free = nr; 948 count = 1; 949 } 950 } 951 } 952 if (count > 0) { 953 mark_inode_dirty(inode); 954 ext2_free_blocks (inode, block_to_free, count); 955 } 956 } 957 958 /** 959 * ext2_free_branches - free an array of branches 960 * @inode: inode we are dealing with 961 * @p: array of block numbers 962 * @q: pointer immediately past the end of array 963 * @depth: depth of the branches to free 964 * 965 * We are freeing all blocks refered from these branches (numbers are 966 * stored as little-endian 32-bit) and updating @inode->i_blocks 967 * appropriately. 968 */ 969 static void ext2_free_branches(struct inode *inode, __le32 *p, __le32 *q, int depth) 970 { 971 struct buffer_head * bh; 972 unsigned long nr; 973 974 if (depth--) { 975 int addr_per_block = EXT2_ADDR_PER_BLOCK(inode->i_sb); 976 for ( ; p < q ; p++) { 977 nr = le32_to_cpu(*p); 978 if (!nr) 979 continue; 980 *p = 0; 981 bh = sb_bread(inode->i_sb, nr); 982 /* 983 * A read failure? Report error and clear slot 984 * (should be rare). 985 */ 986 if (!bh) { 987 ext2_error(inode->i_sb, "ext2_free_branches", 988 "Read failure, inode=%ld, block=%ld", 989 inode->i_ino, nr); 990 continue; 991 } 992 ext2_free_branches(inode, 993 (__le32*)bh->b_data, 994 (__le32*)bh->b_data + addr_per_block, 995 depth); 996 bforget(bh); 997 ext2_free_blocks(inode, nr, 1); 998 mark_inode_dirty(inode); 999 } 1000 } else 1001 ext2_free_data(inode, p, q); 1002 } 1003 1004 void ext2_truncate(struct inode *inode) 1005 { 1006 __le32 *i_data = EXT2_I(inode)->i_data; 1007 struct ext2_inode_info *ei = EXT2_I(inode); 1008 int addr_per_block = EXT2_ADDR_PER_BLOCK(inode->i_sb); 1009 int offsets[4]; 1010 Indirect chain[4]; 1011 Indirect *partial; 1012 __le32 nr = 0; 1013 int n; 1014 long iblock; 1015 unsigned blocksize; 1016 1017 if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || 1018 S_ISLNK(inode->i_mode))) 1019 return; 1020 if (ext2_inode_is_fast_symlink(inode)) 1021 return; 1022 if (IS_APPEND(inode) || IS_IMMUTABLE(inode)) 1023 return; 1024 1025 blocksize = inode->i_sb->s_blocksize; 1026 iblock = (inode->i_size + blocksize-1) 1027 >> EXT2_BLOCK_SIZE_BITS(inode->i_sb); 1028 1029 if (mapping_is_xip(inode->i_mapping)) 1030 xip_truncate_page(inode->i_mapping, inode->i_size); 1031 else if (test_opt(inode->i_sb, NOBH)) 1032 nobh_truncate_page(inode->i_mapping, 1033 inode->i_size, ext2_get_block); 1034 else 1035 block_truncate_page(inode->i_mapping, 1036 inode->i_size, ext2_get_block); 1037 1038 n = ext2_block_to_path(inode, iblock, offsets, NULL); 1039 if (n == 0) 1040 return; 1041 1042 /* 1043 * From here we block out all ext2_get_block() callers who want to 1044 * modify the block allocation tree. 1045 */ 1046 mutex_lock(&ei->truncate_mutex); 1047 1048 if (n == 1) { 1049 ext2_free_data(inode, i_data+offsets[0], 1050 i_data + EXT2_NDIR_BLOCKS); 1051 goto do_indirects; 1052 } 1053 1054 partial = ext2_find_shared(inode, n, offsets, chain, &nr); 1055 /* Kill the top of shared branch (already detached) */ 1056 if (nr) { 1057 if (partial == chain) 1058 mark_inode_dirty(inode); 1059 else 1060 mark_buffer_dirty_inode(partial->bh, inode); 1061 ext2_free_branches(inode, &nr, &nr+1, (chain+n-1) - partial); 1062 } 1063 /* Clear the ends of indirect blocks on the shared branch */ 1064 while (partial > chain) { 1065 ext2_free_branches(inode, 1066 partial->p + 1, 1067 (__le32*)partial->bh->b_data+addr_per_block, 1068 (chain+n-1) - partial); 1069 mark_buffer_dirty_inode(partial->bh, inode); 1070 brelse (partial->bh); 1071 partial--; 1072 } 1073 do_indirects: 1074 /* Kill the remaining (whole) subtrees */ 1075 switch (offsets[0]) { 1076 default: 1077 nr = i_data[EXT2_IND_BLOCK]; 1078 if (nr) { 1079 i_data[EXT2_IND_BLOCK] = 0; 1080 mark_inode_dirty(inode); 1081 ext2_free_branches(inode, &nr, &nr+1, 1); 1082 } 1083 case EXT2_IND_BLOCK: 1084 nr = i_data[EXT2_DIND_BLOCK]; 1085 if (nr) { 1086 i_data[EXT2_DIND_BLOCK] = 0; 1087 mark_inode_dirty(inode); 1088 ext2_free_branches(inode, &nr, &nr+1, 2); 1089 } 1090 case EXT2_DIND_BLOCK: 1091 nr = i_data[EXT2_TIND_BLOCK]; 1092 if (nr) { 1093 i_data[EXT2_TIND_BLOCK] = 0; 1094 mark_inode_dirty(inode); 1095 ext2_free_branches(inode, &nr, &nr+1, 3); 1096 } 1097 case EXT2_TIND_BLOCK: 1098 ; 1099 } 1100 1101 ext2_discard_reservation(inode); 1102 1103 mutex_unlock(&ei->truncate_mutex); 1104 inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC; 1105 if (inode_needs_sync(inode)) { 1106 sync_mapping_buffers(inode->i_mapping); 1107 ext2_sync_inode (inode); 1108 } else { 1109 mark_inode_dirty(inode); 1110 } 1111 } 1112 1113 static struct ext2_inode *ext2_get_inode(struct super_block *sb, ino_t ino, 1114 struct buffer_head **p) 1115 { 1116 struct buffer_head * bh; 1117 unsigned long block_group; 1118 unsigned long block; 1119 unsigned long offset; 1120 struct ext2_group_desc * gdp; 1121 1122 *p = NULL; 1123 if ((ino != EXT2_ROOT_INO && ino < EXT2_FIRST_INO(sb)) || 1124 ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count)) 1125 goto Einval; 1126 1127 block_group = (ino - 1) / EXT2_INODES_PER_GROUP(sb); 1128 gdp = ext2_get_group_desc(sb, block_group, NULL); 1129 if (!gdp) 1130 goto Egdp; 1131 /* 1132 * Figure out the offset within the block group inode table 1133 */ 1134 offset = ((ino - 1) % EXT2_INODES_PER_GROUP(sb)) * EXT2_INODE_SIZE(sb); 1135 block = le32_to_cpu(gdp->bg_inode_table) + 1136 (offset >> EXT2_BLOCK_SIZE_BITS(sb)); 1137 if (!(bh = sb_bread(sb, block))) 1138 goto Eio; 1139 1140 *p = bh; 1141 offset &= (EXT2_BLOCK_SIZE(sb) - 1); 1142 return (struct ext2_inode *) (bh->b_data + offset); 1143 1144 Einval: 1145 ext2_error(sb, "ext2_get_inode", "bad inode number: %lu", 1146 (unsigned long) ino); 1147 return ERR_PTR(-EINVAL); 1148 Eio: 1149 ext2_error(sb, "ext2_get_inode", 1150 "unable to read inode block - inode=%lu, block=%lu", 1151 (unsigned long) ino, block); 1152 Egdp: 1153 return ERR_PTR(-EIO); 1154 } 1155 1156 void ext2_set_inode_flags(struct inode *inode) 1157 { 1158 unsigned int flags = EXT2_I(inode)->i_flags; 1159 1160 inode->i_flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC); 1161 if (flags & EXT2_SYNC_FL) 1162 inode->i_flags |= S_SYNC; 1163 if (flags & EXT2_APPEND_FL) 1164 inode->i_flags |= S_APPEND; 1165 if (flags & EXT2_IMMUTABLE_FL) 1166 inode->i_flags |= S_IMMUTABLE; 1167 if (flags & EXT2_NOATIME_FL) 1168 inode->i_flags |= S_NOATIME; 1169 if (flags & EXT2_DIRSYNC_FL) 1170 inode->i_flags |= S_DIRSYNC; 1171 } 1172 1173 /* Propagate flags from i_flags to EXT2_I(inode)->i_flags */ 1174 void ext2_get_inode_flags(struct ext2_inode_info *ei) 1175 { 1176 unsigned int flags = ei->vfs_inode.i_flags; 1177 1178 ei->i_flags &= ~(EXT2_SYNC_FL|EXT2_APPEND_FL| 1179 EXT2_IMMUTABLE_FL|EXT2_NOATIME_FL|EXT2_DIRSYNC_FL); 1180 if (flags & S_SYNC) 1181 ei->i_flags |= EXT2_SYNC_FL; 1182 if (flags & S_APPEND) 1183 ei->i_flags |= EXT2_APPEND_FL; 1184 if (flags & S_IMMUTABLE) 1185 ei->i_flags |= EXT2_IMMUTABLE_FL; 1186 if (flags & S_NOATIME) 1187 ei->i_flags |= EXT2_NOATIME_FL; 1188 if (flags & S_DIRSYNC) 1189 ei->i_flags |= EXT2_DIRSYNC_FL; 1190 } 1191 1192 struct inode *ext2_iget (struct super_block *sb, unsigned long ino) 1193 { 1194 struct ext2_inode_info *ei; 1195 struct buffer_head * bh; 1196 struct ext2_inode *raw_inode; 1197 struct inode *inode; 1198 long ret = -EIO; 1199 int n; 1200 1201 inode = iget_locked(sb, ino); 1202 if (!inode) 1203 return ERR_PTR(-ENOMEM); 1204 if (!(inode->i_state & I_NEW)) 1205 return inode; 1206 1207 ei = EXT2_I(inode); 1208 #ifdef CONFIG_EXT2_FS_POSIX_ACL 1209 ei->i_acl = EXT2_ACL_NOT_CACHED; 1210 ei->i_default_acl = EXT2_ACL_NOT_CACHED; 1211 #endif 1212 ei->i_block_alloc_info = NULL; 1213 1214 raw_inode = ext2_get_inode(inode->i_sb, ino, &bh); 1215 if (IS_ERR(raw_inode)) { 1216 ret = PTR_ERR(raw_inode); 1217 goto bad_inode; 1218 } 1219 1220 inode->i_mode = le16_to_cpu(raw_inode->i_mode); 1221 inode->i_uid = (uid_t)le16_to_cpu(raw_inode->i_uid_low); 1222 inode->i_gid = (gid_t)le16_to_cpu(raw_inode->i_gid_low); 1223 if (!(test_opt (inode->i_sb, NO_UID32))) { 1224 inode->i_uid |= le16_to_cpu(raw_inode->i_uid_high) << 16; 1225 inode->i_gid |= le16_to_cpu(raw_inode->i_gid_high) << 16; 1226 } 1227 inode->i_nlink = le16_to_cpu(raw_inode->i_links_count); 1228 inode->i_size = le32_to_cpu(raw_inode->i_size); 1229 inode->i_atime.tv_sec = (signed)le32_to_cpu(raw_inode->i_atime); 1230 inode->i_ctime.tv_sec = (signed)le32_to_cpu(raw_inode->i_ctime); 1231 inode->i_mtime.tv_sec = (signed)le32_to_cpu(raw_inode->i_mtime); 1232 inode->i_atime.tv_nsec = inode->i_mtime.tv_nsec = inode->i_ctime.tv_nsec = 0; 1233 ei->i_dtime = le32_to_cpu(raw_inode->i_dtime); 1234 /* We now have enough fields to check if the inode was active or not. 1235 * This is needed because nfsd might try to access dead inodes 1236 * the test is that same one that e2fsck uses 1237 * NeilBrown 1999oct15 1238 */ 1239 if (inode->i_nlink == 0 && (inode->i_mode == 0 || ei->i_dtime)) { 1240 /* this inode is deleted */ 1241 brelse (bh); 1242 ret = -ESTALE; 1243 goto bad_inode; 1244 } 1245 inode->i_blocks = le32_to_cpu(raw_inode->i_blocks); 1246 ei->i_flags = le32_to_cpu(raw_inode->i_flags); 1247 ei->i_faddr = le32_to_cpu(raw_inode->i_faddr); 1248 ei->i_frag_no = raw_inode->i_frag; 1249 ei->i_frag_size = raw_inode->i_fsize; 1250 ei->i_file_acl = le32_to_cpu(raw_inode->i_file_acl); 1251 ei->i_dir_acl = 0; 1252 if (S_ISREG(inode->i_mode)) 1253 inode->i_size |= ((__u64)le32_to_cpu(raw_inode->i_size_high)) << 32; 1254 else 1255 ei->i_dir_acl = le32_to_cpu(raw_inode->i_dir_acl); 1256 ei->i_dtime = 0; 1257 inode->i_generation = le32_to_cpu(raw_inode->i_generation); 1258 ei->i_state = 0; 1259 ei->i_block_group = (ino - 1) / EXT2_INODES_PER_GROUP(inode->i_sb); 1260 ei->i_dir_start_lookup = 0; 1261 1262 /* 1263 * NOTE! The in-memory inode i_data array is in little-endian order 1264 * even on big-endian machines: we do NOT byteswap the block numbers! 1265 */ 1266 for (n = 0; n < EXT2_N_BLOCKS; n++) 1267 ei->i_data[n] = raw_inode->i_block[n]; 1268 1269 if (S_ISREG(inode->i_mode)) { 1270 inode->i_op = &ext2_file_inode_operations; 1271 if (ext2_use_xip(inode->i_sb)) { 1272 inode->i_mapping->a_ops = &ext2_aops_xip; 1273 inode->i_fop = &ext2_xip_file_operations; 1274 } else if (test_opt(inode->i_sb, NOBH)) { 1275 inode->i_mapping->a_ops = &ext2_nobh_aops; 1276 inode->i_fop = &ext2_file_operations; 1277 } else { 1278 inode->i_mapping->a_ops = &ext2_aops; 1279 inode->i_fop = &ext2_file_operations; 1280 } 1281 } else if (S_ISDIR(inode->i_mode)) { 1282 inode->i_op = &ext2_dir_inode_operations; 1283 inode->i_fop = &ext2_dir_operations; 1284 if (test_opt(inode->i_sb, NOBH)) 1285 inode->i_mapping->a_ops = &ext2_nobh_aops; 1286 else 1287 inode->i_mapping->a_ops = &ext2_aops; 1288 } else if (S_ISLNK(inode->i_mode)) { 1289 if (ext2_inode_is_fast_symlink(inode)) 1290 inode->i_op = &ext2_fast_symlink_inode_operations; 1291 else { 1292 inode->i_op = &ext2_symlink_inode_operations; 1293 if (test_opt(inode->i_sb, NOBH)) 1294 inode->i_mapping->a_ops = &ext2_nobh_aops; 1295 else 1296 inode->i_mapping->a_ops = &ext2_aops; 1297 } 1298 } else { 1299 inode->i_op = &ext2_special_inode_operations; 1300 if (raw_inode->i_block[0]) 1301 init_special_inode(inode, inode->i_mode, 1302 old_decode_dev(le32_to_cpu(raw_inode->i_block[0]))); 1303 else 1304 init_special_inode(inode, inode->i_mode, 1305 new_decode_dev(le32_to_cpu(raw_inode->i_block[1]))); 1306 } 1307 brelse (bh); 1308 ext2_set_inode_flags(inode); 1309 unlock_new_inode(inode); 1310 return inode; 1311 1312 bad_inode: 1313 iget_failed(inode); 1314 return ERR_PTR(ret); 1315 } 1316 1317 static int ext2_update_inode(struct inode * inode, int do_sync) 1318 { 1319 struct ext2_inode_info *ei = EXT2_I(inode); 1320 struct super_block *sb = inode->i_sb; 1321 ino_t ino = inode->i_ino; 1322 uid_t uid = inode->i_uid; 1323 gid_t gid = inode->i_gid; 1324 struct buffer_head * bh; 1325 struct ext2_inode * raw_inode = ext2_get_inode(sb, ino, &bh); 1326 int n; 1327 int err = 0; 1328 1329 if (IS_ERR(raw_inode)) 1330 return -EIO; 1331 1332 /* For fields not not tracking in the in-memory inode, 1333 * initialise them to zero for new inodes. */ 1334 if (ei->i_state & EXT2_STATE_NEW) 1335 memset(raw_inode, 0, EXT2_SB(sb)->s_inode_size); 1336 1337 ext2_get_inode_flags(ei); 1338 raw_inode->i_mode = cpu_to_le16(inode->i_mode); 1339 if (!(test_opt(sb, NO_UID32))) { 1340 raw_inode->i_uid_low = cpu_to_le16(low_16_bits(uid)); 1341 raw_inode->i_gid_low = cpu_to_le16(low_16_bits(gid)); 1342 /* 1343 * Fix up interoperability with old kernels. Otherwise, old inodes get 1344 * re-used with the upper 16 bits of the uid/gid intact 1345 */ 1346 if (!ei->i_dtime) { 1347 raw_inode->i_uid_high = cpu_to_le16(high_16_bits(uid)); 1348 raw_inode->i_gid_high = cpu_to_le16(high_16_bits(gid)); 1349 } else { 1350 raw_inode->i_uid_high = 0; 1351 raw_inode->i_gid_high = 0; 1352 } 1353 } else { 1354 raw_inode->i_uid_low = cpu_to_le16(fs_high2lowuid(uid)); 1355 raw_inode->i_gid_low = cpu_to_le16(fs_high2lowgid(gid)); 1356 raw_inode->i_uid_high = 0; 1357 raw_inode->i_gid_high = 0; 1358 } 1359 raw_inode->i_links_count = cpu_to_le16(inode->i_nlink); 1360 raw_inode->i_size = cpu_to_le32(inode->i_size); 1361 raw_inode->i_atime = cpu_to_le32(inode->i_atime.tv_sec); 1362 raw_inode->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec); 1363 raw_inode->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec); 1364 1365 raw_inode->i_blocks = cpu_to_le32(inode->i_blocks); 1366 raw_inode->i_dtime = cpu_to_le32(ei->i_dtime); 1367 raw_inode->i_flags = cpu_to_le32(ei->i_flags); 1368 raw_inode->i_faddr = cpu_to_le32(ei->i_faddr); 1369 raw_inode->i_frag = ei->i_frag_no; 1370 raw_inode->i_fsize = ei->i_frag_size; 1371 raw_inode->i_file_acl = cpu_to_le32(ei->i_file_acl); 1372 if (!S_ISREG(inode->i_mode)) 1373 raw_inode->i_dir_acl = cpu_to_le32(ei->i_dir_acl); 1374 else { 1375 raw_inode->i_size_high = cpu_to_le32(inode->i_size >> 32); 1376 if (inode->i_size > 0x7fffffffULL) { 1377 if (!EXT2_HAS_RO_COMPAT_FEATURE(sb, 1378 EXT2_FEATURE_RO_COMPAT_LARGE_FILE) || 1379 EXT2_SB(sb)->s_es->s_rev_level == 1380 cpu_to_le32(EXT2_GOOD_OLD_REV)) { 1381 /* If this is the first large file 1382 * created, add a flag to the superblock. 1383 */ 1384 lock_kernel(); 1385 ext2_update_dynamic_rev(sb); 1386 EXT2_SET_RO_COMPAT_FEATURE(sb, 1387 EXT2_FEATURE_RO_COMPAT_LARGE_FILE); 1388 unlock_kernel(); 1389 ext2_write_super(sb); 1390 } 1391 } 1392 } 1393 1394 raw_inode->i_generation = cpu_to_le32(inode->i_generation); 1395 if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) { 1396 if (old_valid_dev(inode->i_rdev)) { 1397 raw_inode->i_block[0] = 1398 cpu_to_le32(old_encode_dev(inode->i_rdev)); 1399 raw_inode->i_block[1] = 0; 1400 } else { 1401 raw_inode->i_block[0] = 0; 1402 raw_inode->i_block[1] = 1403 cpu_to_le32(new_encode_dev(inode->i_rdev)); 1404 raw_inode->i_block[2] = 0; 1405 } 1406 } else for (n = 0; n < EXT2_N_BLOCKS; n++) 1407 raw_inode->i_block[n] = ei->i_data[n]; 1408 mark_buffer_dirty(bh); 1409 if (do_sync) { 1410 sync_dirty_buffer(bh); 1411 if (buffer_req(bh) && !buffer_uptodate(bh)) { 1412 printk ("IO error syncing ext2 inode [%s:%08lx]\n", 1413 sb->s_id, (unsigned long) ino); 1414 err = -EIO; 1415 } 1416 } 1417 ei->i_state &= ~EXT2_STATE_NEW; 1418 brelse (bh); 1419 return err; 1420 } 1421 1422 int ext2_write_inode(struct inode *inode, int wait) 1423 { 1424 return ext2_update_inode(inode, wait); 1425 } 1426 1427 int ext2_sync_inode(struct inode *inode) 1428 { 1429 struct writeback_control wbc = { 1430 .sync_mode = WB_SYNC_ALL, 1431 .nr_to_write = 0, /* sys_fsync did this */ 1432 }; 1433 return sync_inode(inode, &wbc); 1434 } 1435 1436 int ext2_setattr(struct dentry *dentry, struct iattr *iattr) 1437 { 1438 struct inode *inode = dentry->d_inode; 1439 int error; 1440 1441 error = inode_change_ok(inode, iattr); 1442 if (error) 1443 return error; 1444 if ((iattr->ia_valid & ATTR_UID && iattr->ia_uid != inode->i_uid) || 1445 (iattr->ia_valid & ATTR_GID && iattr->ia_gid != inode->i_gid)) { 1446 error = DQUOT_TRANSFER(inode, iattr) ? -EDQUOT : 0; 1447 if (error) 1448 return error; 1449 } 1450 error = inode_setattr(inode, iattr); 1451 if (!error && (iattr->ia_valid & ATTR_MODE)) 1452 error = ext2_acl_chmod(inode); 1453 return error; 1454 } 1455