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 static int __ext2_write_inode(struct inode *inode, int do_sync); 45 46 /* 47 * Test whether an inode is a fast symlink. 48 */ 49 static inline int ext2_inode_is_fast_symlink(struct inode *inode) 50 { 51 int ea_blocks = EXT2_I(inode)->i_file_acl ? 52 (inode->i_sb->s_blocksize >> 9) : 0; 53 54 return (S_ISLNK(inode->i_mode) && 55 inode->i_blocks - ea_blocks == 0); 56 } 57 58 /* 59 * Called at the last iput() if i_nlink is zero. 60 */ 61 void ext2_delete_inode (struct inode * inode) 62 { 63 if (!is_bad_inode(inode)) 64 dquot_initialize(inode); 65 truncate_inode_pages(&inode->i_data, 0); 66 67 if (is_bad_inode(inode)) 68 goto no_delete; 69 EXT2_I(inode)->i_dtime = get_seconds(); 70 mark_inode_dirty(inode); 71 __ext2_write_inode(inode, inode_needs_sync(inode)); 72 73 inode->i_size = 0; 74 if (inode->i_blocks) 75 ext2_truncate (inode); 76 ext2_free_inode (inode); 77 78 return; 79 no_delete: 80 clear_inode(inode); /* We must guarantee clearing of inode... */ 81 } 82 83 typedef struct { 84 __le32 *p; 85 __le32 key; 86 struct buffer_head *bh; 87 } Indirect; 88 89 static inline void add_chain(Indirect *p, struct buffer_head *bh, __le32 *v) 90 { 91 p->key = *(p->p = v); 92 p->bh = bh; 93 } 94 95 static inline int verify_chain(Indirect *from, Indirect *to) 96 { 97 while (from <= to && from->key == *from->p) 98 from++; 99 return (from > to); 100 } 101 102 /** 103 * ext2_block_to_path - parse the block number into array of offsets 104 * @inode: inode in question (we are only interested in its superblock) 105 * @i_block: block number to be parsed 106 * @offsets: array to store the offsets in 107 * @boundary: set this non-zero if the referred-to block is likely to be 108 * followed (on disk) by an indirect block. 109 * To store the locations of file's data ext2 uses a data structure common 110 * for UNIX filesystems - tree of pointers anchored in the inode, with 111 * data blocks at leaves and indirect blocks in intermediate nodes. 112 * This function translates the block number into path in that tree - 113 * return value is the path length and @offsets[n] is the offset of 114 * pointer to (n+1)th node in the nth one. If @block is out of range 115 * (negative or too large) warning is printed and zero returned. 116 * 117 * Note: function doesn't find node addresses, so no IO is needed. All 118 * we need to know is the capacity of indirect blocks (taken from the 119 * inode->i_sb). 120 */ 121 122 /* 123 * Portability note: the last comparison (check that we fit into triple 124 * indirect block) is spelled differently, because otherwise on an 125 * architecture with 32-bit longs and 8Kb pages we might get into trouble 126 * if our filesystem had 8Kb blocks. We might use long long, but that would 127 * kill us on x86. Oh, well, at least the sign propagation does not matter - 128 * i_block would have to be negative in the very beginning, so we would not 129 * get there at all. 130 */ 131 132 static int ext2_block_to_path(struct inode *inode, 133 long i_block, int offsets[4], int *boundary) 134 { 135 int ptrs = EXT2_ADDR_PER_BLOCK(inode->i_sb); 136 int ptrs_bits = EXT2_ADDR_PER_BLOCK_BITS(inode->i_sb); 137 const long direct_blocks = EXT2_NDIR_BLOCKS, 138 indirect_blocks = ptrs, 139 double_blocks = (1 << (ptrs_bits * 2)); 140 int n = 0; 141 int final = 0; 142 143 if (i_block < 0) { 144 ext2_msg(inode->i_sb, KERN_WARNING, 145 "warning: %s: block < 0", __func__); 146 } else if (i_block < direct_blocks) { 147 offsets[n++] = i_block; 148 final = direct_blocks; 149 } else if ( (i_block -= direct_blocks) < indirect_blocks) { 150 offsets[n++] = EXT2_IND_BLOCK; 151 offsets[n++] = i_block; 152 final = ptrs; 153 } else if ((i_block -= indirect_blocks) < double_blocks) { 154 offsets[n++] = EXT2_DIND_BLOCK; 155 offsets[n++] = i_block >> ptrs_bits; 156 offsets[n++] = i_block & (ptrs - 1); 157 final = ptrs; 158 } else if (((i_block -= double_blocks) >> (ptrs_bits * 2)) < ptrs) { 159 offsets[n++] = EXT2_TIND_BLOCK; 160 offsets[n++] = i_block >> (ptrs_bits * 2); 161 offsets[n++] = (i_block >> ptrs_bits) & (ptrs - 1); 162 offsets[n++] = i_block & (ptrs - 1); 163 final = ptrs; 164 } else { 165 ext2_msg(inode->i_sb, KERN_WARNING, 166 "warning: %s: block is too big", __func__); 167 } 168 if (boundary) 169 *boundary = final - 1 - (i_block & (ptrs - 1)); 170 171 return n; 172 } 173 174 /** 175 * ext2_get_branch - read the chain of indirect blocks leading to data 176 * @inode: inode in question 177 * @depth: depth of the chain (1 - direct pointer, etc.) 178 * @offsets: offsets of pointers in inode/indirect blocks 179 * @chain: place to store the result 180 * @err: here we store the error value 181 * 182 * Function fills the array of triples <key, p, bh> and returns %NULL 183 * if everything went OK or the pointer to the last filled triple 184 * (incomplete one) otherwise. Upon the return chain[i].key contains 185 * the number of (i+1)-th block in the chain (as it is stored in memory, 186 * i.e. little-endian 32-bit), chain[i].p contains the address of that 187 * number (it points into struct inode for i==0 and into the bh->b_data 188 * for i>0) and chain[i].bh points to the buffer_head of i-th indirect 189 * block for i>0 and NULL for i==0. In other words, it holds the block 190 * numbers of the chain, addresses they were taken from (and where we can 191 * verify that chain did not change) and buffer_heads hosting these 192 * numbers. 193 * 194 * Function stops when it stumbles upon zero pointer (absent block) 195 * (pointer to last triple returned, *@err == 0) 196 * or when it gets an IO error reading an indirect block 197 * (ditto, *@err == -EIO) 198 * or when it notices that chain had been changed while it was reading 199 * (ditto, *@err == -EAGAIN) 200 * or when it reads all @depth-1 indirect blocks successfully and finds 201 * the whole chain, all way to the data (returns %NULL, *err == 0). 202 */ 203 static Indirect *ext2_get_branch(struct inode *inode, 204 int depth, 205 int *offsets, 206 Indirect chain[4], 207 int *err) 208 { 209 struct super_block *sb = inode->i_sb; 210 Indirect *p = chain; 211 struct buffer_head *bh; 212 213 *err = 0; 214 /* i_data is not going away, no lock needed */ 215 add_chain (chain, NULL, EXT2_I(inode)->i_data + *offsets); 216 if (!p->key) 217 goto no_block; 218 while (--depth) { 219 bh = sb_bread(sb, le32_to_cpu(p->key)); 220 if (!bh) 221 goto failure; 222 read_lock(&EXT2_I(inode)->i_meta_lock); 223 if (!verify_chain(chain, p)) 224 goto changed; 225 add_chain(++p, bh, (__le32*)bh->b_data + *++offsets); 226 read_unlock(&EXT2_I(inode)->i_meta_lock); 227 if (!p->key) 228 goto no_block; 229 } 230 return NULL; 231 232 changed: 233 read_unlock(&EXT2_I(inode)->i_meta_lock); 234 brelse(bh); 235 *err = -EAGAIN; 236 goto no_block; 237 failure: 238 *err = -EIO; 239 no_block: 240 return p; 241 } 242 243 /** 244 * ext2_find_near - find a place for allocation with sufficient locality 245 * @inode: owner 246 * @ind: descriptor of indirect block. 247 * 248 * This function returns the preferred place for block allocation. 249 * It is used when heuristic for sequential allocation fails. 250 * Rules are: 251 * + if there is a block to the left of our position - allocate near it. 252 * + if pointer will live in indirect block - allocate near that block. 253 * + if pointer will live in inode - allocate in the same cylinder group. 254 * 255 * In the latter case we colour the starting block by the callers PID to 256 * prevent it from clashing with concurrent allocations for a different inode 257 * in the same block group. The PID is used here so that functionally related 258 * files will be close-by on-disk. 259 * 260 * Caller must make sure that @ind is valid and will stay that way. 261 */ 262 263 static ext2_fsblk_t ext2_find_near(struct inode *inode, Indirect *ind) 264 { 265 struct ext2_inode_info *ei = EXT2_I(inode); 266 __le32 *start = ind->bh ? (__le32 *) ind->bh->b_data : ei->i_data; 267 __le32 *p; 268 ext2_fsblk_t bg_start; 269 ext2_fsblk_t colour; 270 271 /* Try to find previous block */ 272 for (p = ind->p - 1; p >= start; p--) 273 if (*p) 274 return le32_to_cpu(*p); 275 276 /* No such thing, so let's try location of indirect block */ 277 if (ind->bh) 278 return ind->bh->b_blocknr; 279 280 /* 281 * It is going to be refered from inode itself? OK, just put it into 282 * the same cylinder group then. 283 */ 284 bg_start = ext2_group_first_block_no(inode->i_sb, ei->i_block_group); 285 colour = (current->pid % 16) * 286 (EXT2_BLOCKS_PER_GROUP(inode->i_sb) / 16); 287 return bg_start + colour; 288 } 289 290 /** 291 * ext2_find_goal - find a preferred place for allocation. 292 * @inode: owner 293 * @block: block we want 294 * @partial: pointer to the last triple within a chain 295 * 296 * Returns preferred place for a block (the goal). 297 */ 298 299 static inline ext2_fsblk_t ext2_find_goal(struct inode *inode, long block, 300 Indirect *partial) 301 { 302 struct ext2_block_alloc_info *block_i; 303 304 block_i = EXT2_I(inode)->i_block_alloc_info; 305 306 /* 307 * try the heuristic for sequential allocation, 308 * failing that at least try to get decent locality. 309 */ 310 if (block_i && (block == block_i->last_alloc_logical_block + 1) 311 && (block_i->last_alloc_physical_block != 0)) { 312 return block_i->last_alloc_physical_block + 1; 313 } 314 315 return ext2_find_near(inode, partial); 316 } 317 318 /** 319 * ext2_blks_to_allocate: Look up the block map and count the number 320 * of direct blocks need to be allocated for the given branch. 321 * 322 * @branch: chain of indirect blocks 323 * @k: number of blocks need for indirect blocks 324 * @blks: number of data blocks to be mapped. 325 * @blocks_to_boundary: the offset in the indirect block 326 * 327 * return the total number of blocks to be allocate, including the 328 * direct and indirect blocks. 329 */ 330 static int 331 ext2_blks_to_allocate(Indirect * branch, int k, unsigned long blks, 332 int blocks_to_boundary) 333 { 334 unsigned long count = 0; 335 336 /* 337 * Simple case, [t,d]Indirect block(s) has not allocated yet 338 * then it's clear blocks on that path have not allocated 339 */ 340 if (k > 0) { 341 /* right now don't hanel cross boundary allocation */ 342 if (blks < blocks_to_boundary + 1) 343 count += blks; 344 else 345 count += blocks_to_boundary + 1; 346 return count; 347 } 348 349 count++; 350 while (count < blks && count <= blocks_to_boundary 351 && le32_to_cpu(*(branch[0].p + count)) == 0) { 352 count++; 353 } 354 return count; 355 } 356 357 /** 358 * ext2_alloc_blocks: multiple allocate blocks needed for a branch 359 * @indirect_blks: the number of blocks need to allocate for indirect 360 * blocks 361 * 362 * @new_blocks: on return it will store the new block numbers for 363 * the indirect blocks(if needed) and the first direct block, 364 * @blks: on return it will store the total number of allocated 365 * direct blocks 366 */ 367 static int ext2_alloc_blocks(struct inode *inode, 368 ext2_fsblk_t goal, int indirect_blks, int blks, 369 ext2_fsblk_t new_blocks[4], int *err) 370 { 371 int target, i; 372 unsigned long count = 0; 373 int index = 0; 374 ext2_fsblk_t current_block = 0; 375 int ret = 0; 376 377 /* 378 * Here we try to allocate the requested multiple blocks at once, 379 * on a best-effort basis. 380 * To build a branch, we should allocate blocks for 381 * the indirect blocks(if not allocated yet), and at least 382 * the first direct block of this branch. That's the 383 * minimum number of blocks need to allocate(required) 384 */ 385 target = blks + indirect_blks; 386 387 while (1) { 388 count = target; 389 /* allocating blocks for indirect blocks and direct blocks */ 390 current_block = ext2_new_blocks(inode,goal,&count,err); 391 if (*err) 392 goto failed_out; 393 394 target -= count; 395 /* allocate blocks for indirect blocks */ 396 while (index < indirect_blks && count) { 397 new_blocks[index++] = current_block++; 398 count--; 399 } 400 401 if (count > 0) 402 break; 403 } 404 405 /* save the new block number for the first direct block */ 406 new_blocks[index] = current_block; 407 408 /* total number of blocks allocated for direct blocks */ 409 ret = count; 410 *err = 0; 411 return ret; 412 failed_out: 413 for (i = 0; i <index; i++) 414 ext2_free_blocks(inode, new_blocks[i], 1); 415 return ret; 416 } 417 418 /** 419 * ext2_alloc_branch - allocate and set up a chain of blocks. 420 * @inode: owner 421 * @num: depth of the chain (number of blocks to allocate) 422 * @offsets: offsets (in the blocks) to store the pointers to next. 423 * @branch: place to store the chain in. 424 * 425 * This function allocates @num blocks, zeroes out all but the last one, 426 * links them into chain and (if we are synchronous) writes them to disk. 427 * In other words, it prepares a branch that can be spliced onto the 428 * inode. It stores the information about that chain in the branch[], in 429 * the same format as ext2_get_branch() would do. We are calling it after 430 * we had read the existing part of chain and partial points to the last 431 * triple of that (one with zero ->key). Upon the exit we have the same 432 * picture as after the successful ext2_get_block(), excpet that in one 433 * place chain is disconnected - *branch->p is still zero (we did not 434 * set the last link), but branch->key contains the number that should 435 * be placed into *branch->p to fill that gap. 436 * 437 * If allocation fails we free all blocks we've allocated (and forget 438 * their buffer_heads) and return the error value the from failed 439 * ext2_alloc_block() (normally -ENOSPC). Otherwise we set the chain 440 * as described above and return 0. 441 */ 442 443 static int ext2_alloc_branch(struct inode *inode, 444 int indirect_blks, int *blks, ext2_fsblk_t goal, 445 int *offsets, Indirect *branch) 446 { 447 int blocksize = inode->i_sb->s_blocksize; 448 int i, n = 0; 449 int err = 0; 450 struct buffer_head *bh; 451 int num; 452 ext2_fsblk_t new_blocks[4]; 453 ext2_fsblk_t current_block; 454 455 num = ext2_alloc_blocks(inode, goal, indirect_blks, 456 *blks, new_blocks, &err); 457 if (err) 458 return err; 459 460 branch[0].key = cpu_to_le32(new_blocks[0]); 461 /* 462 * metadata blocks and data blocks are allocated. 463 */ 464 for (n = 1; n <= indirect_blks; n++) { 465 /* 466 * Get buffer_head for parent block, zero it out 467 * and set the pointer to new one, then send 468 * parent to disk. 469 */ 470 bh = sb_getblk(inode->i_sb, new_blocks[n-1]); 471 branch[n].bh = bh; 472 lock_buffer(bh); 473 memset(bh->b_data, 0, blocksize); 474 branch[n].p = (__le32 *) bh->b_data + offsets[n]; 475 branch[n].key = cpu_to_le32(new_blocks[n]); 476 *branch[n].p = branch[n].key; 477 if ( n == indirect_blks) { 478 current_block = new_blocks[n]; 479 /* 480 * End of chain, update the last new metablock of 481 * the chain to point to the new allocated 482 * data blocks numbers 483 */ 484 for (i=1; i < num; i++) 485 *(branch[n].p + i) = cpu_to_le32(++current_block); 486 } 487 set_buffer_uptodate(bh); 488 unlock_buffer(bh); 489 mark_buffer_dirty_inode(bh, inode); 490 /* We used to sync bh here if IS_SYNC(inode). 491 * But we now rely upon generic_write_sync() 492 * and b_inode_buffers. But not for directories. 493 */ 494 if (S_ISDIR(inode->i_mode) && IS_DIRSYNC(inode)) 495 sync_dirty_buffer(bh); 496 } 497 *blks = num; 498 return err; 499 } 500 501 /** 502 * ext2_splice_branch - splice the allocated branch onto inode. 503 * @inode: owner 504 * @block: (logical) number of block we are adding 505 * @where: location of missing link 506 * @num: number of indirect blocks we are adding 507 * @blks: number of direct blocks we are adding 508 * 509 * This function fills the missing link and does all housekeeping needed in 510 * inode (->i_blocks, etc.). In case of success we end up with the full 511 * chain to new block and return 0. 512 */ 513 static void ext2_splice_branch(struct inode *inode, 514 long block, Indirect *where, int num, int blks) 515 { 516 int i; 517 struct ext2_block_alloc_info *block_i; 518 ext2_fsblk_t current_block; 519 520 block_i = EXT2_I(inode)->i_block_alloc_info; 521 522 /* XXX LOCKING probably should have i_meta_lock ?*/ 523 /* That's it */ 524 525 *where->p = where->key; 526 527 /* 528 * Update the host buffer_head or inode to point to more just allocated 529 * direct blocks blocks 530 */ 531 if (num == 0 && blks > 1) { 532 current_block = le32_to_cpu(where->key) + 1; 533 for (i = 1; i < blks; i++) 534 *(where->p + i ) = cpu_to_le32(current_block++); 535 } 536 537 /* 538 * update the most recently allocated logical & physical block 539 * in i_block_alloc_info, to assist find the proper goal block for next 540 * allocation 541 */ 542 if (block_i) { 543 block_i->last_alloc_logical_block = block + blks - 1; 544 block_i->last_alloc_physical_block = 545 le32_to_cpu(where[num].key) + blks - 1; 546 } 547 548 /* We are done with atomic stuff, now do the rest of housekeeping */ 549 550 /* had we spliced it onto indirect block? */ 551 if (where->bh) 552 mark_buffer_dirty_inode(where->bh, inode); 553 554 inode->i_ctime = CURRENT_TIME_SEC; 555 mark_inode_dirty(inode); 556 } 557 558 /* 559 * Allocation strategy is simple: if we have to allocate something, we will 560 * have to go the whole way to leaf. So let's do it before attaching anything 561 * to tree, set linkage between the newborn blocks, write them if sync is 562 * required, recheck the path, free and repeat if check fails, otherwise 563 * set the last missing link (that will protect us from any truncate-generated 564 * removals - all blocks on the path are immune now) and possibly force the 565 * write on the parent block. 566 * That has a nice additional property: no special recovery from the failed 567 * allocations is needed - we simply release blocks and do not touch anything 568 * reachable from inode. 569 * 570 * `handle' can be NULL if create == 0. 571 * 572 * return > 0, # of blocks mapped or allocated. 573 * return = 0, if plain lookup failed. 574 * return < 0, error case. 575 */ 576 static int ext2_get_blocks(struct inode *inode, 577 sector_t iblock, unsigned long maxblocks, 578 struct buffer_head *bh_result, 579 int create) 580 { 581 int err = -EIO; 582 int offsets[4]; 583 Indirect chain[4]; 584 Indirect *partial; 585 ext2_fsblk_t goal; 586 int indirect_blks; 587 int blocks_to_boundary = 0; 588 int depth; 589 struct ext2_inode_info *ei = EXT2_I(inode); 590 int count = 0; 591 ext2_fsblk_t first_block = 0; 592 593 depth = ext2_block_to_path(inode,iblock,offsets,&blocks_to_boundary); 594 595 if (depth == 0) 596 return (err); 597 598 partial = ext2_get_branch(inode, depth, offsets, chain, &err); 599 /* Simplest case - block found, no allocation needed */ 600 if (!partial) { 601 first_block = le32_to_cpu(chain[depth - 1].key); 602 clear_buffer_new(bh_result); /* What's this do? */ 603 count++; 604 /*map more blocks*/ 605 while (count < maxblocks && count <= blocks_to_boundary) { 606 ext2_fsblk_t blk; 607 608 if (!verify_chain(chain, chain + depth - 1)) { 609 /* 610 * Indirect block might be removed by 611 * truncate while we were reading it. 612 * Handling of that case: forget what we've 613 * got now, go to reread. 614 */ 615 err = -EAGAIN; 616 count = 0; 617 break; 618 } 619 blk = le32_to_cpu(*(chain[depth-1].p + count)); 620 if (blk == first_block + count) 621 count++; 622 else 623 break; 624 } 625 if (err != -EAGAIN) 626 goto got_it; 627 } 628 629 /* Next simple case - plain lookup or failed read of indirect block */ 630 if (!create || err == -EIO) 631 goto cleanup; 632 633 mutex_lock(&ei->truncate_mutex); 634 /* 635 * If the indirect block is missing while we are reading 636 * the chain(ext3_get_branch() returns -EAGAIN err), or 637 * if the chain has been changed after we grab the semaphore, 638 * (either because another process truncated this branch, or 639 * another get_block allocated this branch) re-grab the chain to see if 640 * the request block has been allocated or not. 641 * 642 * Since we already block the truncate/other get_block 643 * at this point, we will have the current copy of the chain when we 644 * splice the branch into the tree. 645 */ 646 if (err == -EAGAIN || !verify_chain(chain, partial)) { 647 while (partial > chain) { 648 brelse(partial->bh); 649 partial--; 650 } 651 partial = ext2_get_branch(inode, depth, offsets, chain, &err); 652 if (!partial) { 653 count++; 654 mutex_unlock(&ei->truncate_mutex); 655 if (err) 656 goto cleanup; 657 clear_buffer_new(bh_result); 658 goto got_it; 659 } 660 } 661 662 /* 663 * Okay, we need to do block allocation. Lazily initialize the block 664 * allocation info here if necessary 665 */ 666 if (S_ISREG(inode->i_mode) && (!ei->i_block_alloc_info)) 667 ext2_init_block_alloc_info(inode); 668 669 goal = ext2_find_goal(inode, iblock, partial); 670 671 /* the number of blocks need to allocate for [d,t]indirect blocks */ 672 indirect_blks = (chain + depth) - partial - 1; 673 /* 674 * Next look up the indirect map to count the totoal number of 675 * direct blocks to allocate for this branch. 676 */ 677 count = ext2_blks_to_allocate(partial, indirect_blks, 678 maxblocks, blocks_to_boundary); 679 /* 680 * XXX ???? Block out ext2_truncate while we alter the tree 681 */ 682 err = ext2_alloc_branch(inode, indirect_blks, &count, goal, 683 offsets + (partial - chain), partial); 684 685 if (err) { 686 mutex_unlock(&ei->truncate_mutex); 687 goto cleanup; 688 } 689 690 if (ext2_use_xip(inode->i_sb)) { 691 /* 692 * we need to clear the block 693 */ 694 err = ext2_clear_xip_target (inode, 695 le32_to_cpu(chain[depth-1].key)); 696 if (err) { 697 mutex_unlock(&ei->truncate_mutex); 698 goto cleanup; 699 } 700 } 701 702 ext2_splice_branch(inode, iblock, partial, indirect_blks, count); 703 mutex_unlock(&ei->truncate_mutex); 704 set_buffer_new(bh_result); 705 got_it: 706 map_bh(bh_result, inode->i_sb, le32_to_cpu(chain[depth-1].key)); 707 if (count > blocks_to_boundary) 708 set_buffer_boundary(bh_result); 709 err = count; 710 /* Clean up and exit */ 711 partial = chain + depth - 1; /* the whole chain */ 712 cleanup: 713 while (partial > chain) { 714 brelse(partial->bh); 715 partial--; 716 } 717 return err; 718 } 719 720 int ext2_get_block(struct inode *inode, sector_t iblock, struct buffer_head *bh_result, int create) 721 { 722 unsigned max_blocks = bh_result->b_size >> inode->i_blkbits; 723 int ret = ext2_get_blocks(inode, iblock, max_blocks, 724 bh_result, create); 725 if (ret > 0) { 726 bh_result->b_size = (ret << inode->i_blkbits); 727 ret = 0; 728 } 729 return ret; 730 731 } 732 733 int ext2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, 734 u64 start, u64 len) 735 { 736 return generic_block_fiemap(inode, fieinfo, start, len, 737 ext2_get_block); 738 } 739 740 static int ext2_writepage(struct page *page, struct writeback_control *wbc) 741 { 742 return block_write_full_page(page, ext2_get_block, wbc); 743 } 744 745 static int ext2_readpage(struct file *file, struct page *page) 746 { 747 return mpage_readpage(page, ext2_get_block); 748 } 749 750 static int 751 ext2_readpages(struct file *file, struct address_space *mapping, 752 struct list_head *pages, unsigned nr_pages) 753 { 754 return mpage_readpages(mapping, pages, nr_pages, ext2_get_block); 755 } 756 757 int __ext2_write_begin(struct file *file, struct address_space *mapping, 758 loff_t pos, unsigned len, unsigned flags, 759 struct page **pagep, void **fsdata) 760 { 761 return block_write_begin(file, mapping, pos, len, flags, pagep, fsdata, 762 ext2_get_block); 763 } 764 765 static int 766 ext2_write_begin(struct file *file, struct address_space *mapping, 767 loff_t pos, unsigned len, unsigned flags, 768 struct page **pagep, void **fsdata) 769 { 770 *pagep = NULL; 771 return __ext2_write_begin(file, mapping, pos, len, flags, pagep,fsdata); 772 } 773 774 static int 775 ext2_nobh_write_begin(struct file *file, struct address_space *mapping, 776 loff_t pos, unsigned len, unsigned flags, 777 struct page **pagep, void **fsdata) 778 { 779 /* 780 * Dir-in-pagecache still uses ext2_write_begin. Would have to rework 781 * directory handling code to pass around offsets rather than struct 782 * pages in order to make this work easily. 783 */ 784 return nobh_write_begin(file, mapping, pos, len, flags, pagep, fsdata, 785 ext2_get_block); 786 } 787 788 static int ext2_nobh_writepage(struct page *page, 789 struct writeback_control *wbc) 790 { 791 return nobh_writepage(page, ext2_get_block, wbc); 792 } 793 794 static sector_t ext2_bmap(struct address_space *mapping, sector_t block) 795 { 796 return generic_block_bmap(mapping,block,ext2_get_block); 797 } 798 799 static ssize_t 800 ext2_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov, 801 loff_t offset, unsigned long nr_segs) 802 { 803 struct file *file = iocb->ki_filp; 804 struct inode *inode = file->f_mapping->host; 805 806 return blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev, iov, 807 offset, nr_segs, ext2_get_block, NULL); 808 } 809 810 static int 811 ext2_writepages(struct address_space *mapping, struct writeback_control *wbc) 812 { 813 return mpage_writepages(mapping, wbc, ext2_get_block); 814 } 815 816 const struct address_space_operations ext2_aops = { 817 .readpage = ext2_readpage, 818 .readpages = ext2_readpages, 819 .writepage = ext2_writepage, 820 .sync_page = block_sync_page, 821 .write_begin = ext2_write_begin, 822 .write_end = generic_write_end, 823 .bmap = ext2_bmap, 824 .direct_IO = ext2_direct_IO, 825 .writepages = ext2_writepages, 826 .migratepage = buffer_migrate_page, 827 .is_partially_uptodate = block_is_partially_uptodate, 828 .error_remove_page = generic_error_remove_page, 829 }; 830 831 const struct address_space_operations ext2_aops_xip = { 832 .bmap = ext2_bmap, 833 .get_xip_mem = ext2_get_xip_mem, 834 }; 835 836 const struct address_space_operations ext2_nobh_aops = { 837 .readpage = ext2_readpage, 838 .readpages = ext2_readpages, 839 .writepage = ext2_nobh_writepage, 840 .sync_page = block_sync_page, 841 .write_begin = ext2_nobh_write_begin, 842 .write_end = nobh_write_end, 843 .bmap = ext2_bmap, 844 .direct_IO = ext2_direct_IO, 845 .writepages = ext2_writepages, 846 .migratepage = buffer_migrate_page, 847 .error_remove_page = generic_error_remove_page, 848 }; 849 850 /* 851 * Probably it should be a library function... search for first non-zero word 852 * or memcmp with zero_page, whatever is better for particular architecture. 853 * Linus? 854 */ 855 static inline int all_zeroes(__le32 *p, __le32 *q) 856 { 857 while (p < q) 858 if (*p++) 859 return 0; 860 return 1; 861 } 862 863 /** 864 * ext2_find_shared - find the indirect blocks for partial truncation. 865 * @inode: inode in question 866 * @depth: depth of the affected branch 867 * @offsets: offsets of pointers in that branch (see ext2_block_to_path) 868 * @chain: place to store the pointers to partial indirect blocks 869 * @top: place to the (detached) top of branch 870 * 871 * This is a helper function used by ext2_truncate(). 872 * 873 * When we do truncate() we may have to clean the ends of several indirect 874 * blocks but leave the blocks themselves alive. Block is partially 875 * truncated if some data below the new i_size is refered from it (and 876 * it is on the path to the first completely truncated data block, indeed). 877 * We have to free the top of that path along with everything to the right 878 * of the path. Since no allocation past the truncation point is possible 879 * until ext2_truncate() finishes, we may safely do the latter, but top 880 * of branch may require special attention - pageout below the truncation 881 * point might try to populate it. 882 * 883 * We atomically detach the top of branch from the tree, store the block 884 * number of its root in *@top, pointers to buffer_heads of partially 885 * truncated blocks - in @chain[].bh and pointers to their last elements 886 * that should not be removed - in @chain[].p. Return value is the pointer 887 * to last filled element of @chain. 888 * 889 * The work left to caller to do the actual freeing of subtrees: 890 * a) free the subtree starting from *@top 891 * b) free the subtrees whose roots are stored in 892 * (@chain[i].p+1 .. end of @chain[i].bh->b_data) 893 * c) free the subtrees growing from the inode past the @chain[0].p 894 * (no partially truncated stuff there). 895 */ 896 897 static Indirect *ext2_find_shared(struct inode *inode, 898 int depth, 899 int offsets[4], 900 Indirect chain[4], 901 __le32 *top) 902 { 903 Indirect *partial, *p; 904 int k, err; 905 906 *top = 0; 907 for (k = depth; k > 1 && !offsets[k-1]; k--) 908 ; 909 partial = ext2_get_branch(inode, k, offsets, chain, &err); 910 if (!partial) 911 partial = chain + k-1; 912 /* 913 * If the branch acquired continuation since we've looked at it - 914 * fine, it should all survive and (new) top doesn't belong to us. 915 */ 916 write_lock(&EXT2_I(inode)->i_meta_lock); 917 if (!partial->key && *partial->p) { 918 write_unlock(&EXT2_I(inode)->i_meta_lock); 919 goto no_top; 920 } 921 for (p=partial; p>chain && all_zeroes((__le32*)p->bh->b_data,p->p); p--) 922 ; 923 /* 924 * OK, we've found the last block that must survive. The rest of our 925 * branch should be detached before unlocking. However, if that rest 926 * of branch is all ours and does not grow immediately from the inode 927 * it's easier to cheat and just decrement partial->p. 928 */ 929 if (p == chain + k - 1 && p > chain) { 930 p->p--; 931 } else { 932 *top = *p->p; 933 *p->p = 0; 934 } 935 write_unlock(&EXT2_I(inode)->i_meta_lock); 936 937 while(partial > p) 938 { 939 brelse(partial->bh); 940 partial--; 941 } 942 no_top: 943 return partial; 944 } 945 946 /** 947 * ext2_free_data - free a list of data blocks 948 * @inode: inode we are dealing with 949 * @p: array of block numbers 950 * @q: points immediately past the end of array 951 * 952 * We are freeing all blocks refered from that array (numbers are 953 * stored as little-endian 32-bit) and updating @inode->i_blocks 954 * appropriately. 955 */ 956 static inline void ext2_free_data(struct inode *inode, __le32 *p, __le32 *q) 957 { 958 unsigned long block_to_free = 0, count = 0; 959 unsigned long nr; 960 961 for ( ; p < q ; p++) { 962 nr = le32_to_cpu(*p); 963 if (nr) { 964 *p = 0; 965 /* accumulate blocks to free if they're contiguous */ 966 if (count == 0) 967 goto free_this; 968 else if (block_to_free == nr - count) 969 count++; 970 else { 971 mark_inode_dirty(inode); 972 ext2_free_blocks (inode, block_to_free, count); 973 free_this: 974 block_to_free = nr; 975 count = 1; 976 } 977 } 978 } 979 if (count > 0) { 980 mark_inode_dirty(inode); 981 ext2_free_blocks (inode, block_to_free, count); 982 } 983 } 984 985 /** 986 * ext2_free_branches - free an array of branches 987 * @inode: inode we are dealing with 988 * @p: array of block numbers 989 * @q: pointer immediately past the end of array 990 * @depth: depth of the branches to free 991 * 992 * We are freeing all blocks refered from these branches (numbers are 993 * stored as little-endian 32-bit) and updating @inode->i_blocks 994 * appropriately. 995 */ 996 static void ext2_free_branches(struct inode *inode, __le32 *p, __le32 *q, int depth) 997 { 998 struct buffer_head * bh; 999 unsigned long nr; 1000 1001 if (depth--) { 1002 int addr_per_block = EXT2_ADDR_PER_BLOCK(inode->i_sb); 1003 for ( ; p < q ; p++) { 1004 nr = le32_to_cpu(*p); 1005 if (!nr) 1006 continue; 1007 *p = 0; 1008 bh = sb_bread(inode->i_sb, nr); 1009 /* 1010 * A read failure? Report error and clear slot 1011 * (should be rare). 1012 */ 1013 if (!bh) { 1014 ext2_error(inode->i_sb, "ext2_free_branches", 1015 "Read failure, inode=%ld, block=%ld", 1016 inode->i_ino, nr); 1017 continue; 1018 } 1019 ext2_free_branches(inode, 1020 (__le32*)bh->b_data, 1021 (__le32*)bh->b_data + addr_per_block, 1022 depth); 1023 bforget(bh); 1024 ext2_free_blocks(inode, nr, 1); 1025 mark_inode_dirty(inode); 1026 } 1027 } else 1028 ext2_free_data(inode, p, q); 1029 } 1030 1031 void ext2_truncate(struct inode *inode) 1032 { 1033 __le32 *i_data = EXT2_I(inode)->i_data; 1034 struct ext2_inode_info *ei = EXT2_I(inode); 1035 int addr_per_block = EXT2_ADDR_PER_BLOCK(inode->i_sb); 1036 int offsets[4]; 1037 Indirect chain[4]; 1038 Indirect *partial; 1039 __le32 nr = 0; 1040 int n; 1041 long iblock; 1042 unsigned blocksize; 1043 1044 if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || 1045 S_ISLNK(inode->i_mode))) 1046 return; 1047 if (ext2_inode_is_fast_symlink(inode)) 1048 return; 1049 if (IS_APPEND(inode) || IS_IMMUTABLE(inode)) 1050 return; 1051 1052 blocksize = inode->i_sb->s_blocksize; 1053 iblock = (inode->i_size + blocksize-1) 1054 >> EXT2_BLOCK_SIZE_BITS(inode->i_sb); 1055 1056 if (mapping_is_xip(inode->i_mapping)) 1057 xip_truncate_page(inode->i_mapping, inode->i_size); 1058 else if (test_opt(inode->i_sb, NOBH)) 1059 nobh_truncate_page(inode->i_mapping, 1060 inode->i_size, ext2_get_block); 1061 else 1062 block_truncate_page(inode->i_mapping, 1063 inode->i_size, ext2_get_block); 1064 1065 n = ext2_block_to_path(inode, iblock, offsets, NULL); 1066 if (n == 0) 1067 return; 1068 1069 /* 1070 * From here we block out all ext2_get_block() callers who want to 1071 * modify the block allocation tree. 1072 */ 1073 mutex_lock(&ei->truncate_mutex); 1074 1075 if (n == 1) { 1076 ext2_free_data(inode, i_data+offsets[0], 1077 i_data + EXT2_NDIR_BLOCKS); 1078 goto do_indirects; 1079 } 1080 1081 partial = ext2_find_shared(inode, n, offsets, chain, &nr); 1082 /* Kill the top of shared branch (already detached) */ 1083 if (nr) { 1084 if (partial == chain) 1085 mark_inode_dirty(inode); 1086 else 1087 mark_buffer_dirty_inode(partial->bh, inode); 1088 ext2_free_branches(inode, &nr, &nr+1, (chain+n-1) - partial); 1089 } 1090 /* Clear the ends of indirect blocks on the shared branch */ 1091 while (partial > chain) { 1092 ext2_free_branches(inode, 1093 partial->p + 1, 1094 (__le32*)partial->bh->b_data+addr_per_block, 1095 (chain+n-1) - partial); 1096 mark_buffer_dirty_inode(partial->bh, inode); 1097 brelse (partial->bh); 1098 partial--; 1099 } 1100 do_indirects: 1101 /* Kill the remaining (whole) subtrees */ 1102 switch (offsets[0]) { 1103 default: 1104 nr = i_data[EXT2_IND_BLOCK]; 1105 if (nr) { 1106 i_data[EXT2_IND_BLOCK] = 0; 1107 mark_inode_dirty(inode); 1108 ext2_free_branches(inode, &nr, &nr+1, 1); 1109 } 1110 case EXT2_IND_BLOCK: 1111 nr = i_data[EXT2_DIND_BLOCK]; 1112 if (nr) { 1113 i_data[EXT2_DIND_BLOCK] = 0; 1114 mark_inode_dirty(inode); 1115 ext2_free_branches(inode, &nr, &nr+1, 2); 1116 } 1117 case EXT2_DIND_BLOCK: 1118 nr = i_data[EXT2_TIND_BLOCK]; 1119 if (nr) { 1120 i_data[EXT2_TIND_BLOCK] = 0; 1121 mark_inode_dirty(inode); 1122 ext2_free_branches(inode, &nr, &nr+1, 3); 1123 } 1124 case EXT2_TIND_BLOCK: 1125 ; 1126 } 1127 1128 ext2_discard_reservation(inode); 1129 1130 mutex_unlock(&ei->truncate_mutex); 1131 inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC; 1132 if (inode_needs_sync(inode)) { 1133 sync_mapping_buffers(inode->i_mapping); 1134 ext2_sync_inode (inode); 1135 } else { 1136 mark_inode_dirty(inode); 1137 } 1138 } 1139 1140 static struct ext2_inode *ext2_get_inode(struct super_block *sb, ino_t ino, 1141 struct buffer_head **p) 1142 { 1143 struct buffer_head * bh; 1144 unsigned long block_group; 1145 unsigned long block; 1146 unsigned long offset; 1147 struct ext2_group_desc * gdp; 1148 1149 *p = NULL; 1150 if ((ino != EXT2_ROOT_INO && ino < EXT2_FIRST_INO(sb)) || 1151 ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count)) 1152 goto Einval; 1153 1154 block_group = (ino - 1) / EXT2_INODES_PER_GROUP(sb); 1155 gdp = ext2_get_group_desc(sb, block_group, NULL); 1156 if (!gdp) 1157 goto Egdp; 1158 /* 1159 * Figure out the offset within the block group inode table 1160 */ 1161 offset = ((ino - 1) % EXT2_INODES_PER_GROUP(sb)) * EXT2_INODE_SIZE(sb); 1162 block = le32_to_cpu(gdp->bg_inode_table) + 1163 (offset >> EXT2_BLOCK_SIZE_BITS(sb)); 1164 if (!(bh = sb_bread(sb, block))) 1165 goto Eio; 1166 1167 *p = bh; 1168 offset &= (EXT2_BLOCK_SIZE(sb) - 1); 1169 return (struct ext2_inode *) (bh->b_data + offset); 1170 1171 Einval: 1172 ext2_error(sb, "ext2_get_inode", "bad inode number: %lu", 1173 (unsigned long) ino); 1174 return ERR_PTR(-EINVAL); 1175 Eio: 1176 ext2_error(sb, "ext2_get_inode", 1177 "unable to read inode block - inode=%lu, block=%lu", 1178 (unsigned long) ino, block); 1179 Egdp: 1180 return ERR_PTR(-EIO); 1181 } 1182 1183 void ext2_set_inode_flags(struct inode *inode) 1184 { 1185 unsigned int flags = EXT2_I(inode)->i_flags; 1186 1187 inode->i_flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC); 1188 if (flags & EXT2_SYNC_FL) 1189 inode->i_flags |= S_SYNC; 1190 if (flags & EXT2_APPEND_FL) 1191 inode->i_flags |= S_APPEND; 1192 if (flags & EXT2_IMMUTABLE_FL) 1193 inode->i_flags |= S_IMMUTABLE; 1194 if (flags & EXT2_NOATIME_FL) 1195 inode->i_flags |= S_NOATIME; 1196 if (flags & EXT2_DIRSYNC_FL) 1197 inode->i_flags |= S_DIRSYNC; 1198 } 1199 1200 /* Propagate flags from i_flags to EXT2_I(inode)->i_flags */ 1201 void ext2_get_inode_flags(struct ext2_inode_info *ei) 1202 { 1203 unsigned int flags = ei->vfs_inode.i_flags; 1204 1205 ei->i_flags &= ~(EXT2_SYNC_FL|EXT2_APPEND_FL| 1206 EXT2_IMMUTABLE_FL|EXT2_NOATIME_FL|EXT2_DIRSYNC_FL); 1207 if (flags & S_SYNC) 1208 ei->i_flags |= EXT2_SYNC_FL; 1209 if (flags & S_APPEND) 1210 ei->i_flags |= EXT2_APPEND_FL; 1211 if (flags & S_IMMUTABLE) 1212 ei->i_flags |= EXT2_IMMUTABLE_FL; 1213 if (flags & S_NOATIME) 1214 ei->i_flags |= EXT2_NOATIME_FL; 1215 if (flags & S_DIRSYNC) 1216 ei->i_flags |= EXT2_DIRSYNC_FL; 1217 } 1218 1219 struct inode *ext2_iget (struct super_block *sb, unsigned long ino) 1220 { 1221 struct ext2_inode_info *ei; 1222 struct buffer_head * bh; 1223 struct ext2_inode *raw_inode; 1224 struct inode *inode; 1225 long ret = -EIO; 1226 int n; 1227 1228 inode = iget_locked(sb, ino); 1229 if (!inode) 1230 return ERR_PTR(-ENOMEM); 1231 if (!(inode->i_state & I_NEW)) 1232 return inode; 1233 1234 ei = EXT2_I(inode); 1235 ei->i_block_alloc_info = NULL; 1236 1237 raw_inode = ext2_get_inode(inode->i_sb, ino, &bh); 1238 if (IS_ERR(raw_inode)) { 1239 ret = PTR_ERR(raw_inode); 1240 goto bad_inode; 1241 } 1242 1243 inode->i_mode = le16_to_cpu(raw_inode->i_mode); 1244 inode->i_uid = (uid_t)le16_to_cpu(raw_inode->i_uid_low); 1245 inode->i_gid = (gid_t)le16_to_cpu(raw_inode->i_gid_low); 1246 if (!(test_opt (inode->i_sb, NO_UID32))) { 1247 inode->i_uid |= le16_to_cpu(raw_inode->i_uid_high) << 16; 1248 inode->i_gid |= le16_to_cpu(raw_inode->i_gid_high) << 16; 1249 } 1250 inode->i_nlink = le16_to_cpu(raw_inode->i_links_count); 1251 inode->i_size = le32_to_cpu(raw_inode->i_size); 1252 inode->i_atime.tv_sec = (signed)le32_to_cpu(raw_inode->i_atime); 1253 inode->i_ctime.tv_sec = (signed)le32_to_cpu(raw_inode->i_ctime); 1254 inode->i_mtime.tv_sec = (signed)le32_to_cpu(raw_inode->i_mtime); 1255 inode->i_atime.tv_nsec = inode->i_mtime.tv_nsec = inode->i_ctime.tv_nsec = 0; 1256 ei->i_dtime = le32_to_cpu(raw_inode->i_dtime); 1257 /* We now have enough fields to check if the inode was active or not. 1258 * This is needed because nfsd might try to access dead inodes 1259 * the test is that same one that e2fsck uses 1260 * NeilBrown 1999oct15 1261 */ 1262 if (inode->i_nlink == 0 && (inode->i_mode == 0 || ei->i_dtime)) { 1263 /* this inode is deleted */ 1264 brelse (bh); 1265 ret = -ESTALE; 1266 goto bad_inode; 1267 } 1268 inode->i_blocks = le32_to_cpu(raw_inode->i_blocks); 1269 ei->i_flags = le32_to_cpu(raw_inode->i_flags); 1270 ei->i_faddr = le32_to_cpu(raw_inode->i_faddr); 1271 ei->i_frag_no = raw_inode->i_frag; 1272 ei->i_frag_size = raw_inode->i_fsize; 1273 ei->i_file_acl = le32_to_cpu(raw_inode->i_file_acl); 1274 ei->i_dir_acl = 0; 1275 if (S_ISREG(inode->i_mode)) 1276 inode->i_size |= ((__u64)le32_to_cpu(raw_inode->i_size_high)) << 32; 1277 else 1278 ei->i_dir_acl = le32_to_cpu(raw_inode->i_dir_acl); 1279 ei->i_dtime = 0; 1280 inode->i_generation = le32_to_cpu(raw_inode->i_generation); 1281 ei->i_state = 0; 1282 ei->i_block_group = (ino - 1) / EXT2_INODES_PER_GROUP(inode->i_sb); 1283 ei->i_dir_start_lookup = 0; 1284 1285 /* 1286 * NOTE! The in-memory inode i_data array is in little-endian order 1287 * even on big-endian machines: we do NOT byteswap the block numbers! 1288 */ 1289 for (n = 0; n < EXT2_N_BLOCKS; n++) 1290 ei->i_data[n] = raw_inode->i_block[n]; 1291 1292 if (S_ISREG(inode->i_mode)) { 1293 inode->i_op = &ext2_file_inode_operations; 1294 if (ext2_use_xip(inode->i_sb)) { 1295 inode->i_mapping->a_ops = &ext2_aops_xip; 1296 inode->i_fop = &ext2_xip_file_operations; 1297 } else if (test_opt(inode->i_sb, NOBH)) { 1298 inode->i_mapping->a_ops = &ext2_nobh_aops; 1299 inode->i_fop = &ext2_file_operations; 1300 } else { 1301 inode->i_mapping->a_ops = &ext2_aops; 1302 inode->i_fop = &ext2_file_operations; 1303 } 1304 } else if (S_ISDIR(inode->i_mode)) { 1305 inode->i_op = &ext2_dir_inode_operations; 1306 inode->i_fop = &ext2_dir_operations; 1307 if (test_opt(inode->i_sb, NOBH)) 1308 inode->i_mapping->a_ops = &ext2_nobh_aops; 1309 else 1310 inode->i_mapping->a_ops = &ext2_aops; 1311 } else if (S_ISLNK(inode->i_mode)) { 1312 if (ext2_inode_is_fast_symlink(inode)) { 1313 inode->i_op = &ext2_fast_symlink_inode_operations; 1314 nd_terminate_link(ei->i_data, inode->i_size, 1315 sizeof(ei->i_data) - 1); 1316 } else { 1317 inode->i_op = &ext2_symlink_inode_operations; 1318 if (test_opt(inode->i_sb, NOBH)) 1319 inode->i_mapping->a_ops = &ext2_nobh_aops; 1320 else 1321 inode->i_mapping->a_ops = &ext2_aops; 1322 } 1323 } else { 1324 inode->i_op = &ext2_special_inode_operations; 1325 if (raw_inode->i_block[0]) 1326 init_special_inode(inode, inode->i_mode, 1327 old_decode_dev(le32_to_cpu(raw_inode->i_block[0]))); 1328 else 1329 init_special_inode(inode, inode->i_mode, 1330 new_decode_dev(le32_to_cpu(raw_inode->i_block[1]))); 1331 } 1332 brelse (bh); 1333 ext2_set_inode_flags(inode); 1334 unlock_new_inode(inode); 1335 return inode; 1336 1337 bad_inode: 1338 iget_failed(inode); 1339 return ERR_PTR(ret); 1340 } 1341 1342 static int __ext2_write_inode(struct inode *inode, int do_sync) 1343 { 1344 struct ext2_inode_info *ei = EXT2_I(inode); 1345 struct super_block *sb = inode->i_sb; 1346 ino_t ino = inode->i_ino; 1347 uid_t uid = inode->i_uid; 1348 gid_t gid = inode->i_gid; 1349 struct buffer_head * bh; 1350 struct ext2_inode * raw_inode = ext2_get_inode(sb, ino, &bh); 1351 int n; 1352 int err = 0; 1353 1354 if (IS_ERR(raw_inode)) 1355 return -EIO; 1356 1357 /* For fields not not tracking in the in-memory inode, 1358 * initialise them to zero for new inodes. */ 1359 if (ei->i_state & EXT2_STATE_NEW) 1360 memset(raw_inode, 0, EXT2_SB(sb)->s_inode_size); 1361 1362 ext2_get_inode_flags(ei); 1363 raw_inode->i_mode = cpu_to_le16(inode->i_mode); 1364 if (!(test_opt(sb, NO_UID32))) { 1365 raw_inode->i_uid_low = cpu_to_le16(low_16_bits(uid)); 1366 raw_inode->i_gid_low = cpu_to_le16(low_16_bits(gid)); 1367 /* 1368 * Fix up interoperability with old kernels. Otherwise, old inodes get 1369 * re-used with the upper 16 bits of the uid/gid intact 1370 */ 1371 if (!ei->i_dtime) { 1372 raw_inode->i_uid_high = cpu_to_le16(high_16_bits(uid)); 1373 raw_inode->i_gid_high = cpu_to_le16(high_16_bits(gid)); 1374 } else { 1375 raw_inode->i_uid_high = 0; 1376 raw_inode->i_gid_high = 0; 1377 } 1378 } else { 1379 raw_inode->i_uid_low = cpu_to_le16(fs_high2lowuid(uid)); 1380 raw_inode->i_gid_low = cpu_to_le16(fs_high2lowgid(gid)); 1381 raw_inode->i_uid_high = 0; 1382 raw_inode->i_gid_high = 0; 1383 } 1384 raw_inode->i_links_count = cpu_to_le16(inode->i_nlink); 1385 raw_inode->i_size = cpu_to_le32(inode->i_size); 1386 raw_inode->i_atime = cpu_to_le32(inode->i_atime.tv_sec); 1387 raw_inode->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec); 1388 raw_inode->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec); 1389 1390 raw_inode->i_blocks = cpu_to_le32(inode->i_blocks); 1391 raw_inode->i_dtime = cpu_to_le32(ei->i_dtime); 1392 raw_inode->i_flags = cpu_to_le32(ei->i_flags); 1393 raw_inode->i_faddr = cpu_to_le32(ei->i_faddr); 1394 raw_inode->i_frag = ei->i_frag_no; 1395 raw_inode->i_fsize = ei->i_frag_size; 1396 raw_inode->i_file_acl = cpu_to_le32(ei->i_file_acl); 1397 if (!S_ISREG(inode->i_mode)) 1398 raw_inode->i_dir_acl = cpu_to_le32(ei->i_dir_acl); 1399 else { 1400 raw_inode->i_size_high = cpu_to_le32(inode->i_size >> 32); 1401 if (inode->i_size > 0x7fffffffULL) { 1402 if (!EXT2_HAS_RO_COMPAT_FEATURE(sb, 1403 EXT2_FEATURE_RO_COMPAT_LARGE_FILE) || 1404 EXT2_SB(sb)->s_es->s_rev_level == 1405 cpu_to_le32(EXT2_GOOD_OLD_REV)) { 1406 /* If this is the first large file 1407 * created, add a flag to the superblock. 1408 */ 1409 lock_kernel(); 1410 ext2_update_dynamic_rev(sb); 1411 EXT2_SET_RO_COMPAT_FEATURE(sb, 1412 EXT2_FEATURE_RO_COMPAT_LARGE_FILE); 1413 unlock_kernel(); 1414 ext2_write_super(sb); 1415 } 1416 } 1417 } 1418 1419 raw_inode->i_generation = cpu_to_le32(inode->i_generation); 1420 if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) { 1421 if (old_valid_dev(inode->i_rdev)) { 1422 raw_inode->i_block[0] = 1423 cpu_to_le32(old_encode_dev(inode->i_rdev)); 1424 raw_inode->i_block[1] = 0; 1425 } else { 1426 raw_inode->i_block[0] = 0; 1427 raw_inode->i_block[1] = 1428 cpu_to_le32(new_encode_dev(inode->i_rdev)); 1429 raw_inode->i_block[2] = 0; 1430 } 1431 } else for (n = 0; n < EXT2_N_BLOCKS; n++) 1432 raw_inode->i_block[n] = ei->i_data[n]; 1433 mark_buffer_dirty(bh); 1434 if (do_sync) { 1435 sync_dirty_buffer(bh); 1436 if (buffer_req(bh) && !buffer_uptodate(bh)) { 1437 printk ("IO error syncing ext2 inode [%s:%08lx]\n", 1438 sb->s_id, (unsigned long) ino); 1439 err = -EIO; 1440 } 1441 } 1442 ei->i_state &= ~EXT2_STATE_NEW; 1443 brelse (bh); 1444 return err; 1445 } 1446 1447 int ext2_write_inode(struct inode *inode, struct writeback_control *wbc) 1448 { 1449 return __ext2_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL); 1450 } 1451 1452 int ext2_sync_inode(struct inode *inode) 1453 { 1454 struct writeback_control wbc = { 1455 .sync_mode = WB_SYNC_ALL, 1456 .nr_to_write = 0, /* sys_fsync did this */ 1457 }; 1458 return sync_inode(inode, &wbc); 1459 } 1460 1461 int ext2_setattr(struct dentry *dentry, struct iattr *iattr) 1462 { 1463 struct inode *inode = dentry->d_inode; 1464 int error; 1465 1466 error = inode_change_ok(inode, iattr); 1467 if (error) 1468 return error; 1469 1470 if (iattr->ia_valid & ATTR_SIZE) 1471 dquot_initialize(inode); 1472 if ((iattr->ia_valid & ATTR_UID && iattr->ia_uid != inode->i_uid) || 1473 (iattr->ia_valid & ATTR_GID && iattr->ia_gid != inode->i_gid)) { 1474 error = dquot_transfer(inode, iattr); 1475 if (error) 1476 return error; 1477 } 1478 error = inode_setattr(inode, iattr); 1479 if (!error && (iattr->ia_valid & ATTR_MODE)) 1480 error = ext2_acl_chmod(inode); 1481 return error; 1482 } 1483