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 <linux/namei.h> 36 #include "ext2.h" 37 #include "acl.h" 38 #include "xip.h" 39 40 MODULE_AUTHOR("Remy Card and others"); 41 MODULE_DESCRIPTION("Second Extended Filesystem"); 42 MODULE_LICENSE("GPL"); 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_write_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 preferred 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 ext2_fsblk_t 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 ext2_fsblk_t bg_start; 263 ext2_fsblk_t 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 = ext2_group_first_block_no(inode->i_sb, ei->i_block_group); 279 colour = (current->pid % 16) * 280 (EXT2_BLOCKS_PER_GROUP(inode->i_sb) / 16); 281 return bg_start + colour; 282 } 283 284 /** 285 * ext2_find_goal - find a preferred place for allocation. 286 * @inode: owner 287 * @block: block we want 288 * @partial: pointer to the last triple within a chain 289 * 290 * Returns preferred place for a block (the goal). 291 */ 292 293 static inline ext2_fsblk_t ext2_find_goal(struct inode *inode, long block, 294 Indirect *partial) 295 { 296 struct ext2_block_alloc_info *block_i; 297 298 block_i = EXT2_I(inode)->i_block_alloc_info; 299 300 /* 301 * try the heuristic for sequential allocation, 302 * failing that at least try to get decent locality. 303 */ 304 if (block_i && (block == block_i->last_alloc_logical_block + 1) 305 && (block_i->last_alloc_physical_block != 0)) { 306 return block_i->last_alloc_physical_block + 1; 307 } 308 309 return ext2_find_near(inode, partial); 310 } 311 312 /** 313 * ext2_blks_to_allocate: Look up the block map and count the number 314 * of direct blocks need to be allocated for the given branch. 315 * 316 * @branch: chain of indirect blocks 317 * @k: number of blocks need for indirect blocks 318 * @blks: number of data blocks to be mapped. 319 * @blocks_to_boundary: the offset in the indirect block 320 * 321 * return the total number of blocks to be allocate, including the 322 * direct and indirect blocks. 323 */ 324 static int 325 ext2_blks_to_allocate(Indirect * branch, int k, unsigned long blks, 326 int blocks_to_boundary) 327 { 328 unsigned long count = 0; 329 330 /* 331 * Simple case, [t,d]Indirect block(s) has not allocated yet 332 * then it's clear blocks on that path have not allocated 333 */ 334 if (k > 0) { 335 /* right now don't hanel cross boundary allocation */ 336 if (blks < blocks_to_boundary + 1) 337 count += blks; 338 else 339 count += blocks_to_boundary + 1; 340 return count; 341 } 342 343 count++; 344 while (count < blks && count <= blocks_to_boundary 345 && le32_to_cpu(*(branch[0].p + count)) == 0) { 346 count++; 347 } 348 return count; 349 } 350 351 /** 352 * ext2_alloc_blocks: multiple allocate blocks needed for a branch 353 * @indirect_blks: the number of blocks need to allocate for indirect 354 * blocks 355 * 356 * @new_blocks: on return it will store the new block numbers for 357 * the indirect blocks(if needed) and the first direct block, 358 * @blks: on return it will store the total number of allocated 359 * direct blocks 360 */ 361 static int ext2_alloc_blocks(struct inode *inode, 362 ext2_fsblk_t goal, int indirect_blks, int blks, 363 ext2_fsblk_t new_blocks[4], int *err) 364 { 365 int target, i; 366 unsigned long count = 0; 367 int index = 0; 368 ext2_fsblk_t current_block = 0; 369 int ret = 0; 370 371 /* 372 * Here we try to allocate the requested multiple blocks at once, 373 * on a best-effort basis. 374 * To build a branch, we should allocate blocks for 375 * the indirect blocks(if not allocated yet), and at least 376 * the first direct block of this branch. That's the 377 * minimum number of blocks need to allocate(required) 378 */ 379 target = blks + indirect_blks; 380 381 while (1) { 382 count = target; 383 /* allocating blocks for indirect blocks and direct blocks */ 384 current_block = ext2_new_blocks(inode,goal,&count,err); 385 if (*err) 386 goto failed_out; 387 388 target -= count; 389 /* allocate blocks for indirect blocks */ 390 while (index < indirect_blks && count) { 391 new_blocks[index++] = current_block++; 392 count--; 393 } 394 395 if (count > 0) 396 break; 397 } 398 399 /* save the new block number for the first direct block */ 400 new_blocks[index] = current_block; 401 402 /* total number of blocks allocated for direct blocks */ 403 ret = count; 404 *err = 0; 405 return ret; 406 failed_out: 407 for (i = 0; i <index; i++) 408 ext2_free_blocks(inode, new_blocks[i], 1); 409 return ret; 410 } 411 412 /** 413 * ext2_alloc_branch - allocate and set up a chain of blocks. 414 * @inode: owner 415 * @num: depth of the chain (number of blocks to allocate) 416 * @offsets: offsets (in the blocks) to store the pointers to next. 417 * @branch: place to store the chain in. 418 * 419 * This function allocates @num blocks, zeroes out all but the last one, 420 * links them into chain and (if we are synchronous) writes them to disk. 421 * In other words, it prepares a branch that can be spliced onto the 422 * inode. It stores the information about that chain in the branch[], in 423 * the same format as ext2_get_branch() would do. We are calling it after 424 * we had read the existing part of chain and partial points to the last 425 * triple of that (one with zero ->key). Upon the exit we have the same 426 * picture as after the successful ext2_get_block(), excpet that in one 427 * place chain is disconnected - *branch->p is still zero (we did not 428 * set the last link), but branch->key contains the number that should 429 * be placed into *branch->p to fill that gap. 430 * 431 * If allocation fails we free all blocks we've allocated (and forget 432 * their buffer_heads) and return the error value the from failed 433 * ext2_alloc_block() (normally -ENOSPC). Otherwise we set the chain 434 * as described above and return 0. 435 */ 436 437 static int ext2_alloc_branch(struct inode *inode, 438 int indirect_blks, int *blks, ext2_fsblk_t goal, 439 int *offsets, Indirect *branch) 440 { 441 int blocksize = inode->i_sb->s_blocksize; 442 int i, n = 0; 443 int err = 0; 444 struct buffer_head *bh; 445 int num; 446 ext2_fsblk_t new_blocks[4]; 447 ext2_fsblk_t current_block; 448 449 num = ext2_alloc_blocks(inode, goal, indirect_blks, 450 *blks, new_blocks, &err); 451 if (err) 452 return err; 453 454 branch[0].key = cpu_to_le32(new_blocks[0]); 455 /* 456 * metadata blocks and data blocks are allocated. 457 */ 458 for (n = 1; n <= indirect_blks; n++) { 459 /* 460 * Get buffer_head for parent block, zero it out 461 * and set the pointer to new one, then send 462 * parent to disk. 463 */ 464 bh = sb_getblk(inode->i_sb, new_blocks[n-1]); 465 branch[n].bh = bh; 466 lock_buffer(bh); 467 memset(bh->b_data, 0, blocksize); 468 branch[n].p = (__le32 *) bh->b_data + offsets[n]; 469 branch[n].key = cpu_to_le32(new_blocks[n]); 470 *branch[n].p = branch[n].key; 471 if ( n == indirect_blks) { 472 current_block = new_blocks[n]; 473 /* 474 * End of chain, update the last new metablock of 475 * the chain to point to the new allocated 476 * data blocks numbers 477 */ 478 for (i=1; i < num; i++) 479 *(branch[n].p + i) = cpu_to_le32(++current_block); 480 } 481 set_buffer_uptodate(bh); 482 unlock_buffer(bh); 483 mark_buffer_dirty_inode(bh, inode); 484 /* We used to sync bh here if IS_SYNC(inode). 485 * But we now rely upon generic_write_sync() 486 * and b_inode_buffers. But not for directories. 487 */ 488 if (S_ISDIR(inode->i_mode) && IS_DIRSYNC(inode)) 489 sync_dirty_buffer(bh); 490 } 491 *blks = num; 492 return err; 493 } 494 495 /** 496 * ext2_splice_branch - splice the allocated branch onto inode. 497 * @inode: owner 498 * @block: (logical) number of block we are adding 499 * @where: location of missing link 500 * @num: number of indirect blocks we are adding 501 * @blks: number of direct blocks we are adding 502 * 503 * This function fills the missing link and does all housekeeping needed in 504 * inode (->i_blocks, etc.). In case of success we end up with the full 505 * chain to new block and return 0. 506 */ 507 static void ext2_splice_branch(struct inode *inode, 508 long block, Indirect *where, int num, int blks) 509 { 510 int i; 511 struct ext2_block_alloc_info *block_i; 512 ext2_fsblk_t current_block; 513 514 block_i = EXT2_I(inode)->i_block_alloc_info; 515 516 /* XXX LOCKING probably should have i_meta_lock ?*/ 517 /* That's it */ 518 519 *where->p = where->key; 520 521 /* 522 * Update the host buffer_head or inode to point to more just allocated 523 * direct blocks blocks 524 */ 525 if (num == 0 && blks > 1) { 526 current_block = le32_to_cpu(where->key) + 1; 527 for (i = 1; i < blks; i++) 528 *(where->p + i ) = cpu_to_le32(current_block++); 529 } 530 531 /* 532 * update the most recently allocated logical & physical block 533 * in i_block_alloc_info, to assist find the proper goal block for next 534 * allocation 535 */ 536 if (block_i) { 537 block_i->last_alloc_logical_block = block + blks - 1; 538 block_i->last_alloc_physical_block = 539 le32_to_cpu(where[num].key) + blks - 1; 540 } 541 542 /* We are done with atomic stuff, now do the rest of housekeeping */ 543 544 /* had we spliced it onto indirect block? */ 545 if (where->bh) 546 mark_buffer_dirty_inode(where->bh, inode); 547 548 inode->i_ctime = CURRENT_TIME_SEC; 549 mark_inode_dirty(inode); 550 } 551 552 /* 553 * Allocation strategy is simple: if we have to allocate something, we will 554 * have to go the whole way to leaf. So let's do it before attaching anything 555 * to tree, set linkage between the newborn blocks, write them if sync is 556 * required, recheck the path, free and repeat if check fails, otherwise 557 * set the last missing link (that will protect us from any truncate-generated 558 * removals - all blocks on the path are immune now) and possibly force the 559 * write on the parent block. 560 * That has a nice additional property: no special recovery from the failed 561 * allocations is needed - we simply release blocks and do not touch anything 562 * reachable from inode. 563 * 564 * `handle' can be NULL if create == 0. 565 * 566 * return > 0, # of blocks mapped or allocated. 567 * return = 0, if plain lookup failed. 568 * return < 0, error case. 569 */ 570 static int ext2_get_blocks(struct inode *inode, 571 sector_t iblock, unsigned long maxblocks, 572 struct buffer_head *bh_result, 573 int create) 574 { 575 int err = -EIO; 576 int offsets[4]; 577 Indirect chain[4]; 578 Indirect *partial; 579 ext2_fsblk_t goal; 580 int indirect_blks; 581 int blocks_to_boundary = 0; 582 int depth; 583 struct ext2_inode_info *ei = EXT2_I(inode); 584 int count = 0; 585 ext2_fsblk_t first_block = 0; 586 587 depth = ext2_block_to_path(inode,iblock,offsets,&blocks_to_boundary); 588 589 if (depth == 0) 590 return (err); 591 592 partial = ext2_get_branch(inode, depth, offsets, chain, &err); 593 /* Simplest case - block found, no allocation needed */ 594 if (!partial) { 595 first_block = le32_to_cpu(chain[depth - 1].key); 596 clear_buffer_new(bh_result); /* What's this do? */ 597 count++; 598 /*map more blocks*/ 599 while (count < maxblocks && count <= blocks_to_boundary) { 600 ext2_fsblk_t blk; 601 602 if (!verify_chain(chain, chain + depth - 1)) { 603 /* 604 * Indirect block might be removed by 605 * truncate while we were reading it. 606 * Handling of that case: forget what we've 607 * got now, go to reread. 608 */ 609 err = -EAGAIN; 610 count = 0; 611 break; 612 } 613 blk = le32_to_cpu(*(chain[depth-1].p + count)); 614 if (blk == first_block + count) 615 count++; 616 else 617 break; 618 } 619 if (err != -EAGAIN) 620 goto got_it; 621 } 622 623 /* Next simple case - plain lookup or failed read of indirect block */ 624 if (!create || err == -EIO) 625 goto cleanup; 626 627 mutex_lock(&ei->truncate_mutex); 628 /* 629 * If the indirect block is missing while we are reading 630 * the chain(ext3_get_branch() returns -EAGAIN err), or 631 * if the chain has been changed after we grab the semaphore, 632 * (either because another process truncated this branch, or 633 * another get_block allocated this branch) re-grab the chain to see if 634 * the request block has been allocated or not. 635 * 636 * Since we already block the truncate/other get_block 637 * at this point, we will have the current copy of the chain when we 638 * splice the branch into the tree. 639 */ 640 if (err == -EAGAIN || !verify_chain(chain, partial)) { 641 while (partial > chain) { 642 brelse(partial->bh); 643 partial--; 644 } 645 partial = ext2_get_branch(inode, depth, offsets, chain, &err); 646 if (!partial) { 647 count++; 648 mutex_unlock(&ei->truncate_mutex); 649 if (err) 650 goto cleanup; 651 clear_buffer_new(bh_result); 652 goto got_it; 653 } 654 } 655 656 /* 657 * Okay, we need to do block allocation. Lazily initialize the block 658 * allocation info here if necessary 659 */ 660 if (S_ISREG(inode->i_mode) && (!ei->i_block_alloc_info)) 661 ext2_init_block_alloc_info(inode); 662 663 goal = ext2_find_goal(inode, iblock, partial); 664 665 /* the number of blocks need to allocate for [d,t]indirect blocks */ 666 indirect_blks = (chain + depth) - partial - 1; 667 /* 668 * Next look up the indirect map to count the totoal number of 669 * direct blocks to allocate for this branch. 670 */ 671 count = ext2_blks_to_allocate(partial, indirect_blks, 672 maxblocks, blocks_to_boundary); 673 /* 674 * XXX ???? Block out ext2_truncate while we alter the tree 675 */ 676 err = ext2_alloc_branch(inode, indirect_blks, &count, goal, 677 offsets + (partial - chain), partial); 678 679 if (err) { 680 mutex_unlock(&ei->truncate_mutex); 681 goto cleanup; 682 } 683 684 if (ext2_use_xip(inode->i_sb)) { 685 /* 686 * we need to clear the block 687 */ 688 err = ext2_clear_xip_target (inode, 689 le32_to_cpu(chain[depth-1].key)); 690 if (err) { 691 mutex_unlock(&ei->truncate_mutex); 692 goto cleanup; 693 } 694 } 695 696 ext2_splice_branch(inode, iblock, partial, indirect_blks, count); 697 mutex_unlock(&ei->truncate_mutex); 698 set_buffer_new(bh_result); 699 got_it: 700 map_bh(bh_result, inode->i_sb, le32_to_cpu(chain[depth-1].key)); 701 if (count > blocks_to_boundary) 702 set_buffer_boundary(bh_result); 703 err = count; 704 /* Clean up and exit */ 705 partial = chain + depth - 1; /* the whole chain */ 706 cleanup: 707 while (partial > chain) { 708 brelse(partial->bh); 709 partial--; 710 } 711 return err; 712 } 713 714 int ext2_get_block(struct inode *inode, sector_t iblock, struct buffer_head *bh_result, int create) 715 { 716 unsigned max_blocks = bh_result->b_size >> inode->i_blkbits; 717 int ret = ext2_get_blocks(inode, iblock, max_blocks, 718 bh_result, create); 719 if (ret > 0) { 720 bh_result->b_size = (ret << inode->i_blkbits); 721 ret = 0; 722 } 723 return ret; 724 725 } 726 727 int ext2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, 728 u64 start, u64 len) 729 { 730 return generic_block_fiemap(inode, fieinfo, start, len, 731 ext2_get_block); 732 } 733 734 static int ext2_writepage(struct page *page, struct writeback_control *wbc) 735 { 736 return block_write_full_page(page, ext2_get_block, wbc); 737 } 738 739 static int ext2_readpage(struct file *file, struct page *page) 740 { 741 return mpage_readpage(page, ext2_get_block); 742 } 743 744 static int 745 ext2_readpages(struct file *file, struct address_space *mapping, 746 struct list_head *pages, unsigned nr_pages) 747 { 748 return mpage_readpages(mapping, pages, nr_pages, ext2_get_block); 749 } 750 751 int __ext2_write_begin(struct file *file, struct address_space *mapping, 752 loff_t pos, unsigned len, unsigned flags, 753 struct page **pagep, void **fsdata) 754 { 755 return block_write_begin(file, mapping, pos, len, flags, pagep, fsdata, 756 ext2_get_block); 757 } 758 759 static int 760 ext2_write_begin(struct file *file, struct address_space *mapping, 761 loff_t pos, unsigned len, unsigned flags, 762 struct page **pagep, void **fsdata) 763 { 764 *pagep = NULL; 765 return __ext2_write_begin(file, mapping, pos, len, flags, pagep,fsdata); 766 } 767 768 static int 769 ext2_nobh_write_begin(struct file *file, struct address_space *mapping, 770 loff_t pos, unsigned len, unsigned flags, 771 struct page **pagep, void **fsdata) 772 { 773 /* 774 * Dir-in-pagecache still uses ext2_write_begin. Would have to rework 775 * directory handling code to pass around offsets rather than struct 776 * pages in order to make this work easily. 777 */ 778 return nobh_write_begin(file, mapping, pos, len, flags, pagep, fsdata, 779 ext2_get_block); 780 } 781 782 static int ext2_nobh_writepage(struct page *page, 783 struct writeback_control *wbc) 784 { 785 return nobh_writepage(page, ext2_get_block, wbc); 786 } 787 788 static sector_t ext2_bmap(struct address_space *mapping, sector_t block) 789 { 790 return generic_block_bmap(mapping,block,ext2_get_block); 791 } 792 793 static ssize_t 794 ext2_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov, 795 loff_t offset, unsigned long nr_segs) 796 { 797 struct file *file = iocb->ki_filp; 798 struct inode *inode = file->f_mapping->host; 799 800 return blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev, iov, 801 offset, nr_segs, ext2_get_block, NULL); 802 } 803 804 static int 805 ext2_writepages(struct address_space *mapping, struct writeback_control *wbc) 806 { 807 return mpage_writepages(mapping, wbc, ext2_get_block); 808 } 809 810 const struct address_space_operations ext2_aops = { 811 .readpage = ext2_readpage, 812 .readpages = ext2_readpages, 813 .writepage = ext2_writepage, 814 .sync_page = block_sync_page, 815 .write_begin = ext2_write_begin, 816 .write_end = generic_write_end, 817 .bmap = ext2_bmap, 818 .direct_IO = ext2_direct_IO, 819 .writepages = ext2_writepages, 820 .migratepage = buffer_migrate_page, 821 .is_partially_uptodate = block_is_partially_uptodate, 822 .error_remove_page = generic_error_remove_page, 823 }; 824 825 const struct address_space_operations ext2_aops_xip = { 826 .bmap = ext2_bmap, 827 .get_xip_mem = ext2_get_xip_mem, 828 }; 829 830 const struct address_space_operations ext2_nobh_aops = { 831 .readpage = ext2_readpage, 832 .readpages = ext2_readpages, 833 .writepage = ext2_nobh_writepage, 834 .sync_page = block_sync_page, 835 .write_begin = ext2_nobh_write_begin, 836 .write_end = nobh_write_end, 837 .bmap = ext2_bmap, 838 .direct_IO = ext2_direct_IO, 839 .writepages = ext2_writepages, 840 .migratepage = buffer_migrate_page, 841 .error_remove_page = generic_error_remove_page, 842 }; 843 844 /* 845 * Probably it should be a library function... search for first non-zero word 846 * or memcmp with zero_page, whatever is better for particular architecture. 847 * Linus? 848 */ 849 static inline int all_zeroes(__le32 *p, __le32 *q) 850 { 851 while (p < q) 852 if (*p++) 853 return 0; 854 return 1; 855 } 856 857 /** 858 * ext2_find_shared - find the indirect blocks for partial truncation. 859 * @inode: inode in question 860 * @depth: depth of the affected branch 861 * @offsets: offsets of pointers in that branch (see ext2_block_to_path) 862 * @chain: place to store the pointers to partial indirect blocks 863 * @top: place to the (detached) top of branch 864 * 865 * This is a helper function used by ext2_truncate(). 866 * 867 * When we do truncate() we may have to clean the ends of several indirect 868 * blocks but leave the blocks themselves alive. Block is partially 869 * truncated if some data below the new i_size is refered from it (and 870 * it is on the path to the first completely truncated data block, indeed). 871 * We have to free the top of that path along with everything to the right 872 * of the path. Since no allocation past the truncation point is possible 873 * until ext2_truncate() finishes, we may safely do the latter, but top 874 * of branch may require special attention - pageout below the truncation 875 * point might try to populate it. 876 * 877 * We atomically detach the top of branch from the tree, store the block 878 * number of its root in *@top, pointers to buffer_heads of partially 879 * truncated blocks - in @chain[].bh and pointers to their last elements 880 * that should not be removed - in @chain[].p. Return value is the pointer 881 * to last filled element of @chain. 882 * 883 * The work left to caller to do the actual freeing of subtrees: 884 * a) free the subtree starting from *@top 885 * b) free the subtrees whose roots are stored in 886 * (@chain[i].p+1 .. end of @chain[i].bh->b_data) 887 * c) free the subtrees growing from the inode past the @chain[0].p 888 * (no partially truncated stuff there). 889 */ 890 891 static Indirect *ext2_find_shared(struct inode *inode, 892 int depth, 893 int offsets[4], 894 Indirect chain[4], 895 __le32 *top) 896 { 897 Indirect *partial, *p; 898 int k, err; 899 900 *top = 0; 901 for (k = depth; k > 1 && !offsets[k-1]; k--) 902 ; 903 partial = ext2_get_branch(inode, k, offsets, chain, &err); 904 if (!partial) 905 partial = chain + k-1; 906 /* 907 * If the branch acquired continuation since we've looked at it - 908 * fine, it should all survive and (new) top doesn't belong to us. 909 */ 910 write_lock(&EXT2_I(inode)->i_meta_lock); 911 if (!partial->key && *partial->p) { 912 write_unlock(&EXT2_I(inode)->i_meta_lock); 913 goto no_top; 914 } 915 for (p=partial; p>chain && all_zeroes((__le32*)p->bh->b_data,p->p); p--) 916 ; 917 /* 918 * OK, we've found the last block that must survive. The rest of our 919 * branch should be detached before unlocking. However, if that rest 920 * of branch is all ours and does not grow immediately from the inode 921 * it's easier to cheat and just decrement partial->p. 922 */ 923 if (p == chain + k - 1 && p > chain) { 924 p->p--; 925 } else { 926 *top = *p->p; 927 *p->p = 0; 928 } 929 write_unlock(&EXT2_I(inode)->i_meta_lock); 930 931 while(partial > p) 932 { 933 brelse(partial->bh); 934 partial--; 935 } 936 no_top: 937 return partial; 938 } 939 940 /** 941 * ext2_free_data - free a list of data blocks 942 * @inode: inode we are dealing with 943 * @p: array of block numbers 944 * @q: points immediately past the end of array 945 * 946 * We are freeing all blocks refered from that array (numbers are 947 * stored as little-endian 32-bit) and updating @inode->i_blocks 948 * appropriately. 949 */ 950 static inline void ext2_free_data(struct inode *inode, __le32 *p, __le32 *q) 951 { 952 unsigned long block_to_free = 0, count = 0; 953 unsigned long nr; 954 955 for ( ; p < q ; p++) { 956 nr = le32_to_cpu(*p); 957 if (nr) { 958 *p = 0; 959 /* accumulate blocks to free if they're contiguous */ 960 if (count == 0) 961 goto free_this; 962 else if (block_to_free == nr - count) 963 count++; 964 else { 965 mark_inode_dirty(inode); 966 ext2_free_blocks (inode, block_to_free, count); 967 free_this: 968 block_to_free = nr; 969 count = 1; 970 } 971 } 972 } 973 if (count > 0) { 974 mark_inode_dirty(inode); 975 ext2_free_blocks (inode, block_to_free, count); 976 } 977 } 978 979 /** 980 * ext2_free_branches - free an array of branches 981 * @inode: inode we are dealing with 982 * @p: array of block numbers 983 * @q: pointer immediately past the end of array 984 * @depth: depth of the branches to free 985 * 986 * We are freeing all blocks refered from these branches (numbers are 987 * stored as little-endian 32-bit) and updating @inode->i_blocks 988 * appropriately. 989 */ 990 static void ext2_free_branches(struct inode *inode, __le32 *p, __le32 *q, int depth) 991 { 992 struct buffer_head * bh; 993 unsigned long nr; 994 995 if (depth--) { 996 int addr_per_block = EXT2_ADDR_PER_BLOCK(inode->i_sb); 997 for ( ; p < q ; p++) { 998 nr = le32_to_cpu(*p); 999 if (!nr) 1000 continue; 1001 *p = 0; 1002 bh = sb_bread(inode->i_sb, nr); 1003 /* 1004 * A read failure? Report error and clear slot 1005 * (should be rare). 1006 */ 1007 if (!bh) { 1008 ext2_error(inode->i_sb, "ext2_free_branches", 1009 "Read failure, inode=%ld, block=%ld", 1010 inode->i_ino, nr); 1011 continue; 1012 } 1013 ext2_free_branches(inode, 1014 (__le32*)bh->b_data, 1015 (__le32*)bh->b_data + addr_per_block, 1016 depth); 1017 bforget(bh); 1018 ext2_free_blocks(inode, nr, 1); 1019 mark_inode_dirty(inode); 1020 } 1021 } else 1022 ext2_free_data(inode, p, q); 1023 } 1024 1025 void ext2_truncate(struct inode *inode) 1026 { 1027 __le32 *i_data = EXT2_I(inode)->i_data; 1028 struct ext2_inode_info *ei = EXT2_I(inode); 1029 int addr_per_block = EXT2_ADDR_PER_BLOCK(inode->i_sb); 1030 int offsets[4]; 1031 Indirect chain[4]; 1032 Indirect *partial; 1033 __le32 nr = 0; 1034 int n; 1035 long iblock; 1036 unsigned blocksize; 1037 1038 if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || 1039 S_ISLNK(inode->i_mode))) 1040 return; 1041 if (ext2_inode_is_fast_symlink(inode)) 1042 return; 1043 if (IS_APPEND(inode) || IS_IMMUTABLE(inode)) 1044 return; 1045 1046 blocksize = inode->i_sb->s_blocksize; 1047 iblock = (inode->i_size + blocksize-1) 1048 >> EXT2_BLOCK_SIZE_BITS(inode->i_sb); 1049 1050 if (mapping_is_xip(inode->i_mapping)) 1051 xip_truncate_page(inode->i_mapping, inode->i_size); 1052 else if (test_opt(inode->i_sb, NOBH)) 1053 nobh_truncate_page(inode->i_mapping, 1054 inode->i_size, ext2_get_block); 1055 else 1056 block_truncate_page(inode->i_mapping, 1057 inode->i_size, ext2_get_block); 1058 1059 n = ext2_block_to_path(inode, iblock, offsets, NULL); 1060 if (n == 0) 1061 return; 1062 1063 /* 1064 * From here we block out all ext2_get_block() callers who want to 1065 * modify the block allocation tree. 1066 */ 1067 mutex_lock(&ei->truncate_mutex); 1068 1069 if (n == 1) { 1070 ext2_free_data(inode, i_data+offsets[0], 1071 i_data + EXT2_NDIR_BLOCKS); 1072 goto do_indirects; 1073 } 1074 1075 partial = ext2_find_shared(inode, n, offsets, chain, &nr); 1076 /* Kill the top of shared branch (already detached) */ 1077 if (nr) { 1078 if (partial == chain) 1079 mark_inode_dirty(inode); 1080 else 1081 mark_buffer_dirty_inode(partial->bh, inode); 1082 ext2_free_branches(inode, &nr, &nr+1, (chain+n-1) - partial); 1083 } 1084 /* Clear the ends of indirect blocks on the shared branch */ 1085 while (partial > chain) { 1086 ext2_free_branches(inode, 1087 partial->p + 1, 1088 (__le32*)partial->bh->b_data+addr_per_block, 1089 (chain+n-1) - partial); 1090 mark_buffer_dirty_inode(partial->bh, inode); 1091 brelse (partial->bh); 1092 partial--; 1093 } 1094 do_indirects: 1095 /* Kill the remaining (whole) subtrees */ 1096 switch (offsets[0]) { 1097 default: 1098 nr = i_data[EXT2_IND_BLOCK]; 1099 if (nr) { 1100 i_data[EXT2_IND_BLOCK] = 0; 1101 mark_inode_dirty(inode); 1102 ext2_free_branches(inode, &nr, &nr+1, 1); 1103 } 1104 case EXT2_IND_BLOCK: 1105 nr = i_data[EXT2_DIND_BLOCK]; 1106 if (nr) { 1107 i_data[EXT2_DIND_BLOCK] = 0; 1108 mark_inode_dirty(inode); 1109 ext2_free_branches(inode, &nr, &nr+1, 2); 1110 } 1111 case EXT2_DIND_BLOCK: 1112 nr = i_data[EXT2_TIND_BLOCK]; 1113 if (nr) { 1114 i_data[EXT2_TIND_BLOCK] = 0; 1115 mark_inode_dirty(inode); 1116 ext2_free_branches(inode, &nr, &nr+1, 3); 1117 } 1118 case EXT2_TIND_BLOCK: 1119 ; 1120 } 1121 1122 ext2_discard_reservation(inode); 1123 1124 mutex_unlock(&ei->truncate_mutex); 1125 inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC; 1126 if (inode_needs_sync(inode)) { 1127 sync_mapping_buffers(inode->i_mapping); 1128 ext2_sync_inode (inode); 1129 } else { 1130 mark_inode_dirty(inode); 1131 } 1132 } 1133 1134 static struct ext2_inode *ext2_get_inode(struct super_block *sb, ino_t ino, 1135 struct buffer_head **p) 1136 { 1137 struct buffer_head * bh; 1138 unsigned long block_group; 1139 unsigned long block; 1140 unsigned long offset; 1141 struct ext2_group_desc * gdp; 1142 1143 *p = NULL; 1144 if ((ino != EXT2_ROOT_INO && ino < EXT2_FIRST_INO(sb)) || 1145 ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count)) 1146 goto Einval; 1147 1148 block_group = (ino - 1) / EXT2_INODES_PER_GROUP(sb); 1149 gdp = ext2_get_group_desc(sb, block_group, NULL); 1150 if (!gdp) 1151 goto Egdp; 1152 /* 1153 * Figure out the offset within the block group inode table 1154 */ 1155 offset = ((ino - 1) % EXT2_INODES_PER_GROUP(sb)) * EXT2_INODE_SIZE(sb); 1156 block = le32_to_cpu(gdp->bg_inode_table) + 1157 (offset >> EXT2_BLOCK_SIZE_BITS(sb)); 1158 if (!(bh = sb_bread(sb, block))) 1159 goto Eio; 1160 1161 *p = bh; 1162 offset &= (EXT2_BLOCK_SIZE(sb) - 1); 1163 return (struct ext2_inode *) (bh->b_data + offset); 1164 1165 Einval: 1166 ext2_error(sb, "ext2_get_inode", "bad inode number: %lu", 1167 (unsigned long) ino); 1168 return ERR_PTR(-EINVAL); 1169 Eio: 1170 ext2_error(sb, "ext2_get_inode", 1171 "unable to read inode block - inode=%lu, block=%lu", 1172 (unsigned long) ino, block); 1173 Egdp: 1174 return ERR_PTR(-EIO); 1175 } 1176 1177 void ext2_set_inode_flags(struct inode *inode) 1178 { 1179 unsigned int flags = EXT2_I(inode)->i_flags; 1180 1181 inode->i_flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC); 1182 if (flags & EXT2_SYNC_FL) 1183 inode->i_flags |= S_SYNC; 1184 if (flags & EXT2_APPEND_FL) 1185 inode->i_flags |= S_APPEND; 1186 if (flags & EXT2_IMMUTABLE_FL) 1187 inode->i_flags |= S_IMMUTABLE; 1188 if (flags & EXT2_NOATIME_FL) 1189 inode->i_flags |= S_NOATIME; 1190 if (flags & EXT2_DIRSYNC_FL) 1191 inode->i_flags |= S_DIRSYNC; 1192 } 1193 1194 /* Propagate flags from i_flags to EXT2_I(inode)->i_flags */ 1195 void ext2_get_inode_flags(struct ext2_inode_info *ei) 1196 { 1197 unsigned int flags = ei->vfs_inode.i_flags; 1198 1199 ei->i_flags &= ~(EXT2_SYNC_FL|EXT2_APPEND_FL| 1200 EXT2_IMMUTABLE_FL|EXT2_NOATIME_FL|EXT2_DIRSYNC_FL); 1201 if (flags & S_SYNC) 1202 ei->i_flags |= EXT2_SYNC_FL; 1203 if (flags & S_APPEND) 1204 ei->i_flags |= EXT2_APPEND_FL; 1205 if (flags & S_IMMUTABLE) 1206 ei->i_flags |= EXT2_IMMUTABLE_FL; 1207 if (flags & S_NOATIME) 1208 ei->i_flags |= EXT2_NOATIME_FL; 1209 if (flags & S_DIRSYNC) 1210 ei->i_flags |= EXT2_DIRSYNC_FL; 1211 } 1212 1213 struct inode *ext2_iget (struct super_block *sb, unsigned long ino) 1214 { 1215 struct ext2_inode_info *ei; 1216 struct buffer_head * bh; 1217 struct ext2_inode *raw_inode; 1218 struct inode *inode; 1219 long ret = -EIO; 1220 int n; 1221 1222 inode = iget_locked(sb, ino); 1223 if (!inode) 1224 return ERR_PTR(-ENOMEM); 1225 if (!(inode->i_state & I_NEW)) 1226 return inode; 1227 1228 ei = EXT2_I(inode); 1229 ei->i_block_alloc_info = NULL; 1230 1231 raw_inode = ext2_get_inode(inode->i_sb, ino, &bh); 1232 if (IS_ERR(raw_inode)) { 1233 ret = PTR_ERR(raw_inode); 1234 goto bad_inode; 1235 } 1236 1237 inode->i_mode = le16_to_cpu(raw_inode->i_mode); 1238 inode->i_uid = (uid_t)le16_to_cpu(raw_inode->i_uid_low); 1239 inode->i_gid = (gid_t)le16_to_cpu(raw_inode->i_gid_low); 1240 if (!(test_opt (inode->i_sb, NO_UID32))) { 1241 inode->i_uid |= le16_to_cpu(raw_inode->i_uid_high) << 16; 1242 inode->i_gid |= le16_to_cpu(raw_inode->i_gid_high) << 16; 1243 } 1244 inode->i_nlink = le16_to_cpu(raw_inode->i_links_count); 1245 inode->i_size = le32_to_cpu(raw_inode->i_size); 1246 inode->i_atime.tv_sec = (signed)le32_to_cpu(raw_inode->i_atime); 1247 inode->i_ctime.tv_sec = (signed)le32_to_cpu(raw_inode->i_ctime); 1248 inode->i_mtime.tv_sec = (signed)le32_to_cpu(raw_inode->i_mtime); 1249 inode->i_atime.tv_nsec = inode->i_mtime.tv_nsec = inode->i_ctime.tv_nsec = 0; 1250 ei->i_dtime = le32_to_cpu(raw_inode->i_dtime); 1251 /* We now have enough fields to check if the inode was active or not. 1252 * This is needed because nfsd might try to access dead inodes 1253 * the test is that same one that e2fsck uses 1254 * NeilBrown 1999oct15 1255 */ 1256 if (inode->i_nlink == 0 && (inode->i_mode == 0 || ei->i_dtime)) { 1257 /* this inode is deleted */ 1258 brelse (bh); 1259 ret = -ESTALE; 1260 goto bad_inode; 1261 } 1262 inode->i_blocks = le32_to_cpu(raw_inode->i_blocks); 1263 ei->i_flags = le32_to_cpu(raw_inode->i_flags); 1264 ei->i_faddr = le32_to_cpu(raw_inode->i_faddr); 1265 ei->i_frag_no = raw_inode->i_frag; 1266 ei->i_frag_size = raw_inode->i_fsize; 1267 ei->i_file_acl = le32_to_cpu(raw_inode->i_file_acl); 1268 ei->i_dir_acl = 0; 1269 if (S_ISREG(inode->i_mode)) 1270 inode->i_size |= ((__u64)le32_to_cpu(raw_inode->i_size_high)) << 32; 1271 else 1272 ei->i_dir_acl = le32_to_cpu(raw_inode->i_dir_acl); 1273 ei->i_dtime = 0; 1274 inode->i_generation = le32_to_cpu(raw_inode->i_generation); 1275 ei->i_state = 0; 1276 ei->i_block_group = (ino - 1) / EXT2_INODES_PER_GROUP(inode->i_sb); 1277 ei->i_dir_start_lookup = 0; 1278 1279 /* 1280 * NOTE! The in-memory inode i_data array is in little-endian order 1281 * even on big-endian machines: we do NOT byteswap the block numbers! 1282 */ 1283 for (n = 0; n < EXT2_N_BLOCKS; n++) 1284 ei->i_data[n] = raw_inode->i_block[n]; 1285 1286 if (S_ISREG(inode->i_mode)) { 1287 inode->i_op = &ext2_file_inode_operations; 1288 if (ext2_use_xip(inode->i_sb)) { 1289 inode->i_mapping->a_ops = &ext2_aops_xip; 1290 inode->i_fop = &ext2_xip_file_operations; 1291 } else if (test_opt(inode->i_sb, NOBH)) { 1292 inode->i_mapping->a_ops = &ext2_nobh_aops; 1293 inode->i_fop = &ext2_file_operations; 1294 } else { 1295 inode->i_mapping->a_ops = &ext2_aops; 1296 inode->i_fop = &ext2_file_operations; 1297 } 1298 } else if (S_ISDIR(inode->i_mode)) { 1299 inode->i_op = &ext2_dir_inode_operations; 1300 inode->i_fop = &ext2_dir_operations; 1301 if (test_opt(inode->i_sb, NOBH)) 1302 inode->i_mapping->a_ops = &ext2_nobh_aops; 1303 else 1304 inode->i_mapping->a_ops = &ext2_aops; 1305 } else if (S_ISLNK(inode->i_mode)) { 1306 if (ext2_inode_is_fast_symlink(inode)) { 1307 inode->i_op = &ext2_fast_symlink_inode_operations; 1308 nd_terminate_link(ei->i_data, inode->i_size, 1309 sizeof(ei->i_data) - 1); 1310 } else { 1311 inode->i_op = &ext2_symlink_inode_operations; 1312 if (test_opt(inode->i_sb, NOBH)) 1313 inode->i_mapping->a_ops = &ext2_nobh_aops; 1314 else 1315 inode->i_mapping->a_ops = &ext2_aops; 1316 } 1317 } else { 1318 inode->i_op = &ext2_special_inode_operations; 1319 if (raw_inode->i_block[0]) 1320 init_special_inode(inode, inode->i_mode, 1321 old_decode_dev(le32_to_cpu(raw_inode->i_block[0]))); 1322 else 1323 init_special_inode(inode, inode->i_mode, 1324 new_decode_dev(le32_to_cpu(raw_inode->i_block[1]))); 1325 } 1326 brelse (bh); 1327 ext2_set_inode_flags(inode); 1328 unlock_new_inode(inode); 1329 return inode; 1330 1331 bad_inode: 1332 iget_failed(inode); 1333 return ERR_PTR(ret); 1334 } 1335 1336 int ext2_write_inode(struct inode *inode, int do_sync) 1337 { 1338 struct ext2_inode_info *ei = EXT2_I(inode); 1339 struct super_block *sb = inode->i_sb; 1340 ino_t ino = inode->i_ino; 1341 uid_t uid = inode->i_uid; 1342 gid_t gid = inode->i_gid; 1343 struct buffer_head * bh; 1344 struct ext2_inode * raw_inode = ext2_get_inode(sb, ino, &bh); 1345 int n; 1346 int err = 0; 1347 1348 if (IS_ERR(raw_inode)) 1349 return -EIO; 1350 1351 /* For fields not not tracking in the in-memory inode, 1352 * initialise them to zero for new inodes. */ 1353 if (ei->i_state & EXT2_STATE_NEW) 1354 memset(raw_inode, 0, EXT2_SB(sb)->s_inode_size); 1355 1356 ext2_get_inode_flags(ei); 1357 raw_inode->i_mode = cpu_to_le16(inode->i_mode); 1358 if (!(test_opt(sb, NO_UID32))) { 1359 raw_inode->i_uid_low = cpu_to_le16(low_16_bits(uid)); 1360 raw_inode->i_gid_low = cpu_to_le16(low_16_bits(gid)); 1361 /* 1362 * Fix up interoperability with old kernels. Otherwise, old inodes get 1363 * re-used with the upper 16 bits of the uid/gid intact 1364 */ 1365 if (!ei->i_dtime) { 1366 raw_inode->i_uid_high = cpu_to_le16(high_16_bits(uid)); 1367 raw_inode->i_gid_high = cpu_to_le16(high_16_bits(gid)); 1368 } else { 1369 raw_inode->i_uid_high = 0; 1370 raw_inode->i_gid_high = 0; 1371 } 1372 } else { 1373 raw_inode->i_uid_low = cpu_to_le16(fs_high2lowuid(uid)); 1374 raw_inode->i_gid_low = cpu_to_le16(fs_high2lowgid(gid)); 1375 raw_inode->i_uid_high = 0; 1376 raw_inode->i_gid_high = 0; 1377 } 1378 raw_inode->i_links_count = cpu_to_le16(inode->i_nlink); 1379 raw_inode->i_size = cpu_to_le32(inode->i_size); 1380 raw_inode->i_atime = cpu_to_le32(inode->i_atime.tv_sec); 1381 raw_inode->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec); 1382 raw_inode->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec); 1383 1384 raw_inode->i_blocks = cpu_to_le32(inode->i_blocks); 1385 raw_inode->i_dtime = cpu_to_le32(ei->i_dtime); 1386 raw_inode->i_flags = cpu_to_le32(ei->i_flags); 1387 raw_inode->i_faddr = cpu_to_le32(ei->i_faddr); 1388 raw_inode->i_frag = ei->i_frag_no; 1389 raw_inode->i_fsize = ei->i_frag_size; 1390 raw_inode->i_file_acl = cpu_to_le32(ei->i_file_acl); 1391 if (!S_ISREG(inode->i_mode)) 1392 raw_inode->i_dir_acl = cpu_to_le32(ei->i_dir_acl); 1393 else { 1394 raw_inode->i_size_high = cpu_to_le32(inode->i_size >> 32); 1395 if (inode->i_size > 0x7fffffffULL) { 1396 if (!EXT2_HAS_RO_COMPAT_FEATURE(sb, 1397 EXT2_FEATURE_RO_COMPAT_LARGE_FILE) || 1398 EXT2_SB(sb)->s_es->s_rev_level == 1399 cpu_to_le32(EXT2_GOOD_OLD_REV)) { 1400 /* If this is the first large file 1401 * created, add a flag to the superblock. 1402 */ 1403 lock_kernel(); 1404 ext2_update_dynamic_rev(sb); 1405 EXT2_SET_RO_COMPAT_FEATURE(sb, 1406 EXT2_FEATURE_RO_COMPAT_LARGE_FILE); 1407 unlock_kernel(); 1408 ext2_write_super(sb); 1409 } 1410 } 1411 } 1412 1413 raw_inode->i_generation = cpu_to_le32(inode->i_generation); 1414 if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) { 1415 if (old_valid_dev(inode->i_rdev)) { 1416 raw_inode->i_block[0] = 1417 cpu_to_le32(old_encode_dev(inode->i_rdev)); 1418 raw_inode->i_block[1] = 0; 1419 } else { 1420 raw_inode->i_block[0] = 0; 1421 raw_inode->i_block[1] = 1422 cpu_to_le32(new_encode_dev(inode->i_rdev)); 1423 raw_inode->i_block[2] = 0; 1424 } 1425 } else for (n = 0; n < EXT2_N_BLOCKS; n++) 1426 raw_inode->i_block[n] = ei->i_data[n]; 1427 mark_buffer_dirty(bh); 1428 if (do_sync) { 1429 sync_dirty_buffer(bh); 1430 if (buffer_req(bh) && !buffer_uptodate(bh)) { 1431 printk ("IO error syncing ext2 inode [%s:%08lx]\n", 1432 sb->s_id, (unsigned long) ino); 1433 err = -EIO; 1434 } 1435 } 1436 ei->i_state &= ~EXT2_STATE_NEW; 1437 brelse (bh); 1438 return err; 1439 } 1440 1441 int ext2_sync_inode(struct inode *inode) 1442 { 1443 struct writeback_control wbc = { 1444 .sync_mode = WB_SYNC_ALL, 1445 .nr_to_write = 0, /* sys_fsync did this */ 1446 }; 1447 return sync_inode(inode, &wbc); 1448 } 1449 1450 int ext2_setattr(struct dentry *dentry, struct iattr *iattr) 1451 { 1452 struct inode *inode = dentry->d_inode; 1453 int error; 1454 1455 error = inode_change_ok(inode, iattr); 1456 if (error) 1457 return error; 1458 if ((iattr->ia_valid & ATTR_UID && iattr->ia_uid != inode->i_uid) || 1459 (iattr->ia_valid & ATTR_GID && iattr->ia_gid != inode->i_gid)) { 1460 error = vfs_dq_transfer(inode, iattr) ? -EDQUOT : 0; 1461 if (error) 1462 return error; 1463 } 1464 error = inode_setattr(inode, iattr); 1465 if (!error && (iattr->ia_valid & ATTR_MODE)) 1466 error = ext2_acl_chmod(inode); 1467 return error; 1468 } 1469