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