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/time.h> 26 #include <linux/highuid.h> 27 #include <linux/pagemap.h> 28 #include <linux/quotaops.h> 29 #include <linux/module.h> 30 #include <linux/writeback.h> 31 #include <linux/buffer_head.h> 32 #include <linux/mpage.h> 33 #include <linux/fiemap.h> 34 #include <linux/namei.h> 35 #include "ext2.h" 36 #include "acl.h" 37 #include "xip.h" 38 39 MODULE_AUTHOR("Remy Card and others"); 40 MODULE_DESCRIPTION("Second Extended Filesystem"); 41 MODULE_LICENSE("GPL"); 42 43 static int __ext2_write_inode(struct inode *inode, int do_sync); 44 45 /* 46 * Test whether an inode is a fast symlink. 47 */ 48 static inline int ext2_inode_is_fast_symlink(struct inode *inode) 49 { 50 int ea_blocks = EXT2_I(inode)->i_file_acl ? 51 (inode->i_sb->s_blocksize >> 9) : 0; 52 53 return (S_ISLNK(inode->i_mode) && 54 inode->i_blocks - ea_blocks == 0); 55 } 56 57 /* 58 * Called at the last iput() if i_nlink is zero. 59 */ 60 void ext2_delete_inode (struct inode * inode) 61 { 62 if (!is_bad_inode(inode)) 63 dquot_initialize(inode); 64 truncate_inode_pages(&inode->i_data, 0); 65 66 if (is_bad_inode(inode)) 67 goto no_delete; 68 EXT2_I(inode)->i_dtime = get_seconds(); 69 mark_inode_dirty(inode); 70 __ext2_write_inode(inode, inode_needs_sync(inode)); 71 72 inode->i_size = 0; 73 if (inode->i_blocks) 74 ext2_truncate (inode); 75 ext2_free_inode (inode); 76 77 return; 78 no_delete: 79 clear_inode(inode); /* We must guarantee clearing of inode... */ 80 } 81 82 typedef struct { 83 __le32 *p; 84 __le32 key; 85 struct buffer_head *bh; 86 } Indirect; 87 88 static inline void add_chain(Indirect *p, struct buffer_head *bh, __le32 *v) 89 { 90 p->key = *(p->p = v); 91 p->bh = bh; 92 } 93 94 static inline int verify_chain(Indirect *from, Indirect *to) 95 { 96 while (from <= to && from->key == *from->p) 97 from++; 98 return (from > to); 99 } 100 101 /** 102 * ext2_block_to_path - parse the block number into array of offsets 103 * @inode: inode in question (we are only interested in its superblock) 104 * @i_block: block number to be parsed 105 * @offsets: array to store the offsets in 106 * @boundary: set this non-zero if the referred-to block is likely to be 107 * followed (on disk) by an indirect block. 108 * To store the locations of file's data ext2 uses a data structure common 109 * for UNIX filesystems - tree of pointers anchored in the inode, with 110 * data blocks at leaves and indirect blocks in intermediate nodes. 111 * This function translates the block number into path in that tree - 112 * return value is the path length and @offsets[n] is the offset of 113 * pointer to (n+1)th node in the nth one. If @block is out of range 114 * (negative or too large) warning is printed and zero returned. 115 * 116 * Note: function doesn't find node addresses, so no IO is needed. All 117 * we need to know is the capacity of indirect blocks (taken from the 118 * inode->i_sb). 119 */ 120 121 /* 122 * Portability note: the last comparison (check that we fit into triple 123 * indirect block) is spelled differently, because otherwise on an 124 * architecture with 32-bit longs and 8Kb pages we might get into trouble 125 * if our filesystem had 8Kb blocks. We might use long long, but that would 126 * kill us on x86. Oh, well, at least the sign propagation does not matter - 127 * i_block would have to be negative in the very beginning, so we would not 128 * get there at all. 129 */ 130 131 static int ext2_block_to_path(struct inode *inode, 132 long i_block, int offsets[4], int *boundary) 133 { 134 int ptrs = EXT2_ADDR_PER_BLOCK(inode->i_sb); 135 int ptrs_bits = EXT2_ADDR_PER_BLOCK_BITS(inode->i_sb); 136 const long direct_blocks = EXT2_NDIR_BLOCKS, 137 indirect_blocks = ptrs, 138 double_blocks = (1 << (ptrs_bits * 2)); 139 int n = 0; 140 int final = 0; 141 142 if (i_block < 0) { 143 ext2_msg(inode->i_sb, KERN_WARNING, 144 "warning: %s: block < 0", __func__); 145 } else if (i_block < direct_blocks) { 146 offsets[n++] = i_block; 147 final = direct_blocks; 148 } else if ( (i_block -= direct_blocks) < indirect_blocks) { 149 offsets[n++] = EXT2_IND_BLOCK; 150 offsets[n++] = i_block; 151 final = ptrs; 152 } else if ((i_block -= indirect_blocks) < double_blocks) { 153 offsets[n++] = EXT2_DIND_BLOCK; 154 offsets[n++] = i_block >> ptrs_bits; 155 offsets[n++] = i_block & (ptrs - 1); 156 final = ptrs; 157 } else if (((i_block -= double_blocks) >> (ptrs_bits * 2)) < ptrs) { 158 offsets[n++] = EXT2_TIND_BLOCK; 159 offsets[n++] = i_block >> (ptrs_bits * 2); 160 offsets[n++] = (i_block >> ptrs_bits) & (ptrs - 1); 161 offsets[n++] = i_block & (ptrs - 1); 162 final = ptrs; 163 } else { 164 ext2_msg(inode->i_sb, KERN_WARNING, 165 "warning: %s: block is too big", __func__); 166 } 167 if (boundary) 168 *boundary = final - 1 - (i_block & (ptrs - 1)); 169 170 return n; 171 } 172 173 /** 174 * ext2_get_branch - read the chain of indirect blocks leading to data 175 * @inode: inode in question 176 * @depth: depth of the chain (1 - direct pointer, etc.) 177 * @offsets: offsets of pointers in inode/indirect blocks 178 * @chain: place to store the result 179 * @err: here we store the error value 180 * 181 * Function fills the array of triples <key, p, bh> and returns %NULL 182 * if everything went OK or the pointer to the last filled triple 183 * (incomplete one) otherwise. Upon the return chain[i].key contains 184 * the number of (i+1)-th block in the chain (as it is stored in memory, 185 * i.e. little-endian 32-bit), chain[i].p contains the address of that 186 * number (it points into struct inode for i==0 and into the bh->b_data 187 * for i>0) and chain[i].bh points to the buffer_head of i-th indirect 188 * block for i>0 and NULL for i==0. In other words, it holds the block 189 * numbers of the chain, addresses they were taken from (and where we can 190 * verify that chain did not change) and buffer_heads hosting these 191 * numbers. 192 * 193 * Function stops when it stumbles upon zero pointer (absent block) 194 * (pointer to last triple returned, *@err == 0) 195 * or when it gets an IO error reading an indirect block 196 * (ditto, *@err == -EIO) 197 * or when it notices that chain had been changed while it was reading 198 * (ditto, *@err == -EAGAIN) 199 * or when it reads all @depth-1 indirect blocks successfully and finds 200 * the whole chain, all way to the data (returns %NULL, *err == 0). 201 */ 202 static Indirect *ext2_get_branch(struct inode *inode, 203 int depth, 204 int *offsets, 205 Indirect chain[4], 206 int *err) 207 { 208 struct super_block *sb = inode->i_sb; 209 Indirect *p = chain; 210 struct buffer_head *bh; 211 212 *err = 0; 213 /* i_data is not going away, no lock needed */ 214 add_chain (chain, NULL, EXT2_I(inode)->i_data + *offsets); 215 if (!p->key) 216 goto no_block; 217 while (--depth) { 218 bh = sb_bread(sb, le32_to_cpu(p->key)); 219 if (!bh) 220 goto failure; 221 read_lock(&EXT2_I(inode)->i_meta_lock); 222 if (!verify_chain(chain, p)) 223 goto changed; 224 add_chain(++p, bh, (__le32*)bh->b_data + *++offsets); 225 read_unlock(&EXT2_I(inode)->i_meta_lock); 226 if (!p->key) 227 goto no_block; 228 } 229 return NULL; 230 231 changed: 232 read_unlock(&EXT2_I(inode)->i_meta_lock); 233 brelse(bh); 234 *err = -EAGAIN; 235 goto no_block; 236 failure: 237 *err = -EIO; 238 no_block: 239 return p; 240 } 241 242 /** 243 * ext2_find_near - find a place for allocation with sufficient locality 244 * @inode: owner 245 * @ind: descriptor of indirect block. 246 * 247 * This function returns the preferred place for block allocation. 248 * It is used when heuristic for sequential allocation fails. 249 * Rules are: 250 * + if there is a block to the left of our position - allocate near it. 251 * + if pointer will live in indirect block - allocate near that block. 252 * + if pointer will live in inode - allocate in the same cylinder group. 253 * 254 * In the latter case we colour the starting block by the callers PID to 255 * prevent it from clashing with concurrent allocations for a different inode 256 * in the same block group. The PID is used here so that functionally related 257 * files will be close-by on-disk. 258 * 259 * Caller must make sure that @ind is valid and will stay that way. 260 */ 261 262 static ext2_fsblk_t ext2_find_near(struct inode *inode, Indirect *ind) 263 { 264 struct ext2_inode_info *ei = EXT2_I(inode); 265 __le32 *start = ind->bh ? (__le32 *) ind->bh->b_data : ei->i_data; 266 __le32 *p; 267 ext2_fsblk_t bg_start; 268 ext2_fsblk_t colour; 269 270 /* Try to find previous block */ 271 for (p = ind->p - 1; p >= start; p--) 272 if (*p) 273 return le32_to_cpu(*p); 274 275 /* No such thing, so let's try location of indirect block */ 276 if (ind->bh) 277 return ind->bh->b_blocknr; 278 279 /* 280 * It is going to be refered from inode itself? OK, just put it into 281 * the same cylinder group then. 282 */ 283 bg_start = ext2_group_first_block_no(inode->i_sb, ei->i_block_group); 284 colour = (current->pid % 16) * 285 (EXT2_BLOCKS_PER_GROUP(inode->i_sb) / 16); 286 return bg_start + colour; 287 } 288 289 /** 290 * ext2_find_goal - find a preferred place for allocation. 291 * @inode: owner 292 * @block: block we want 293 * @partial: pointer to the last triple within a chain 294 * 295 * Returns preferred place for a block (the goal). 296 */ 297 298 static inline ext2_fsblk_t ext2_find_goal(struct inode *inode, long block, 299 Indirect *partial) 300 { 301 struct ext2_block_alloc_info *block_i; 302 303 block_i = EXT2_I(inode)->i_block_alloc_info; 304 305 /* 306 * try the heuristic for sequential allocation, 307 * failing that at least try to get decent locality. 308 */ 309 if (block_i && (block == block_i->last_alloc_logical_block + 1) 310 && (block_i->last_alloc_physical_block != 0)) { 311 return block_i->last_alloc_physical_block + 1; 312 } 313 314 return ext2_find_near(inode, partial); 315 } 316 317 /** 318 * ext2_blks_to_allocate: Look up the block map and count the number 319 * of direct blocks need to be allocated for the given branch. 320 * 321 * @branch: chain of indirect blocks 322 * @k: number of blocks need for indirect blocks 323 * @blks: number of data blocks to be mapped. 324 * @blocks_to_boundary: the offset in the indirect block 325 * 326 * return the total number of blocks to be allocate, including the 327 * direct and indirect blocks. 328 */ 329 static int 330 ext2_blks_to_allocate(Indirect * branch, int k, unsigned long blks, 331 int blocks_to_boundary) 332 { 333 unsigned long count = 0; 334 335 /* 336 * Simple case, [t,d]Indirect block(s) has not allocated yet 337 * then it's clear blocks on that path have not allocated 338 */ 339 if (k > 0) { 340 /* right now don't hanel cross boundary allocation */ 341 if (blks < blocks_to_boundary + 1) 342 count += blks; 343 else 344 count += blocks_to_boundary + 1; 345 return count; 346 } 347 348 count++; 349 while (count < blks && count <= blocks_to_boundary 350 && le32_to_cpu(*(branch[0].p + count)) == 0) { 351 count++; 352 } 353 return count; 354 } 355 356 /** 357 * ext2_alloc_blocks: multiple allocate blocks needed for a branch 358 * @indirect_blks: the number of blocks need to allocate for indirect 359 * blocks 360 * 361 * @new_blocks: on return it will store the new block numbers for 362 * the indirect blocks(if needed) and the first direct block, 363 * @blks: on return it will store the total number of allocated 364 * direct blocks 365 */ 366 static int ext2_alloc_blocks(struct inode *inode, 367 ext2_fsblk_t goal, int indirect_blks, int blks, 368 ext2_fsblk_t new_blocks[4], int *err) 369 { 370 int target, i; 371 unsigned long count = 0; 372 int index = 0; 373 ext2_fsblk_t current_block = 0; 374 int ret = 0; 375 376 /* 377 * Here we try to allocate the requested multiple blocks at once, 378 * on a best-effort basis. 379 * To build a branch, we should allocate blocks for 380 * the indirect blocks(if not allocated yet), and at least 381 * the first direct block of this branch. That's the 382 * minimum number of blocks need to allocate(required) 383 */ 384 target = blks + indirect_blks; 385 386 while (1) { 387 count = target; 388 /* allocating blocks for indirect blocks and direct blocks */ 389 current_block = ext2_new_blocks(inode,goal,&count,err); 390 if (*err) 391 goto failed_out; 392 393 target -= count; 394 /* allocate blocks for indirect blocks */ 395 while (index < indirect_blks && count) { 396 new_blocks[index++] = current_block++; 397 count--; 398 } 399 400 if (count > 0) 401 break; 402 } 403 404 /* save the new block number for the first direct block */ 405 new_blocks[index] = current_block; 406 407 /* total number of blocks allocated for direct blocks */ 408 ret = count; 409 *err = 0; 410 return ret; 411 failed_out: 412 for (i = 0; i <index; i++) 413 ext2_free_blocks(inode, new_blocks[i], 1); 414 return ret; 415 } 416 417 /** 418 * ext2_alloc_branch - allocate and set up a chain of blocks. 419 * @inode: owner 420 * @num: depth of the chain (number of blocks to allocate) 421 * @offsets: offsets (in the blocks) to store the pointers to next. 422 * @branch: place to store the chain in. 423 * 424 * This function allocates @num blocks, zeroes out all but the last one, 425 * links them into chain and (if we are synchronous) writes them to disk. 426 * In other words, it prepares a branch that can be spliced onto the 427 * inode. It stores the information about that chain in the branch[], in 428 * the same format as ext2_get_branch() would do. We are calling it after 429 * we had read the existing part of chain and partial points to the last 430 * triple of that (one with zero ->key). Upon the exit we have the same 431 * picture as after the successful ext2_get_block(), excpet that in one 432 * place chain is disconnected - *branch->p is still zero (we did not 433 * set the last link), but branch->key contains the number that should 434 * be placed into *branch->p to fill that gap. 435 * 436 * If allocation fails we free all blocks we've allocated (and forget 437 * their buffer_heads) and return the error value the from failed 438 * ext2_alloc_block() (normally -ENOSPC). Otherwise we set the chain 439 * as described above and return 0. 440 */ 441 442 static int ext2_alloc_branch(struct inode *inode, 443 int indirect_blks, int *blks, ext2_fsblk_t goal, 444 int *offsets, Indirect *branch) 445 { 446 int blocksize = inode->i_sb->s_blocksize; 447 int i, n = 0; 448 int err = 0; 449 struct buffer_head *bh; 450 int num; 451 ext2_fsblk_t new_blocks[4]; 452 ext2_fsblk_t current_block; 453 454 num = ext2_alloc_blocks(inode, goal, indirect_blks, 455 *blks, new_blocks, &err); 456 if (err) 457 return err; 458 459 branch[0].key = cpu_to_le32(new_blocks[0]); 460 /* 461 * metadata blocks and data blocks are allocated. 462 */ 463 for (n = 1; n <= indirect_blks; n++) { 464 /* 465 * Get buffer_head for parent block, zero it out 466 * and set the pointer to new one, then send 467 * parent to disk. 468 */ 469 bh = sb_getblk(inode->i_sb, new_blocks[n-1]); 470 branch[n].bh = bh; 471 lock_buffer(bh); 472 memset(bh->b_data, 0, blocksize); 473 branch[n].p = (__le32 *) bh->b_data + offsets[n]; 474 branch[n].key = cpu_to_le32(new_blocks[n]); 475 *branch[n].p = branch[n].key; 476 if ( n == indirect_blks) { 477 current_block = new_blocks[n]; 478 /* 479 * End of chain, update the last new metablock of 480 * the chain to point to the new allocated 481 * data blocks numbers 482 */ 483 for (i=1; i < num; i++) 484 *(branch[n].p + i) = cpu_to_le32(++current_block); 485 } 486 set_buffer_uptodate(bh); 487 unlock_buffer(bh); 488 mark_buffer_dirty_inode(bh, inode); 489 /* We used to sync bh here if IS_SYNC(inode). 490 * But we now rely upon generic_write_sync() 491 * and b_inode_buffers. But not for directories. 492 */ 493 if (S_ISDIR(inode->i_mode) && IS_DIRSYNC(inode)) 494 sync_dirty_buffer(bh); 495 } 496 *blks = num; 497 return err; 498 } 499 500 /** 501 * ext2_splice_branch - splice the allocated branch onto inode. 502 * @inode: owner 503 * @block: (logical) number of block we are adding 504 * @where: location of missing link 505 * @num: number of indirect blocks we are adding 506 * @blks: number of direct blocks we are adding 507 * 508 * This function fills the missing link and does all housekeeping needed in 509 * inode (->i_blocks, etc.). In case of success we end up with the full 510 * chain to new block and return 0. 511 */ 512 static void ext2_splice_branch(struct inode *inode, 513 long block, Indirect *where, int num, int blks) 514 { 515 int i; 516 struct ext2_block_alloc_info *block_i; 517 ext2_fsblk_t current_block; 518 519 block_i = EXT2_I(inode)->i_block_alloc_info; 520 521 /* XXX LOCKING probably should have i_meta_lock ?*/ 522 /* That's it */ 523 524 *where->p = where->key; 525 526 /* 527 * Update the host buffer_head or inode to point to more just allocated 528 * direct blocks blocks 529 */ 530 if (num == 0 && blks > 1) { 531 current_block = le32_to_cpu(where->key) + 1; 532 for (i = 1; i < blks; i++) 533 *(where->p + i ) = cpu_to_le32(current_block++); 534 } 535 536 /* 537 * update the most recently allocated logical & physical block 538 * in i_block_alloc_info, to assist find the proper goal block for next 539 * allocation 540 */ 541 if (block_i) { 542 block_i->last_alloc_logical_block = block + blks - 1; 543 block_i->last_alloc_physical_block = 544 le32_to_cpu(where[num].key) + blks - 1; 545 } 546 547 /* We are done with atomic stuff, now do the rest of housekeeping */ 548 549 /* had we spliced it onto indirect block? */ 550 if (where->bh) 551 mark_buffer_dirty_inode(where->bh, inode); 552 553 inode->i_ctime = CURRENT_TIME_SEC; 554 mark_inode_dirty(inode); 555 } 556 557 /* 558 * Allocation strategy is simple: if we have to allocate something, we will 559 * have to go the whole way to leaf. So let's do it before attaching anything 560 * to tree, set linkage between the newborn blocks, write them if sync is 561 * required, recheck the path, free and repeat if check fails, otherwise 562 * set the last missing link (that will protect us from any truncate-generated 563 * removals - all blocks on the path are immune now) and possibly force the 564 * write on the parent block. 565 * That has a nice additional property: no special recovery from the failed 566 * allocations is needed - we simply release blocks and do not touch anything 567 * reachable from inode. 568 * 569 * `handle' can be NULL if create == 0. 570 * 571 * return > 0, # of blocks mapped or allocated. 572 * return = 0, if plain lookup failed. 573 * return < 0, error case. 574 */ 575 static int ext2_get_blocks(struct inode *inode, 576 sector_t iblock, unsigned long maxblocks, 577 struct buffer_head *bh_result, 578 int create) 579 { 580 int err = -EIO; 581 int offsets[4]; 582 Indirect chain[4]; 583 Indirect *partial; 584 ext2_fsblk_t goal; 585 int indirect_blks; 586 int blocks_to_boundary = 0; 587 int depth; 588 struct ext2_inode_info *ei = EXT2_I(inode); 589 int count = 0; 590 ext2_fsblk_t first_block = 0; 591 592 depth = ext2_block_to_path(inode,iblock,offsets,&blocks_to_boundary); 593 594 if (depth == 0) 595 return (err); 596 597 partial = ext2_get_branch(inode, depth, offsets, chain, &err); 598 /* Simplest case - block found, no allocation needed */ 599 if (!partial) { 600 first_block = le32_to_cpu(chain[depth - 1].key); 601 clear_buffer_new(bh_result); /* What's this do? */ 602 count++; 603 /*map more blocks*/ 604 while (count < maxblocks && count <= blocks_to_boundary) { 605 ext2_fsblk_t blk; 606 607 if (!verify_chain(chain, chain + depth - 1)) { 608 /* 609 * Indirect block might be removed by 610 * truncate while we were reading it. 611 * Handling of that case: forget what we've 612 * got now, go to reread. 613 */ 614 err = -EAGAIN; 615 count = 0; 616 break; 617 } 618 blk = le32_to_cpu(*(chain[depth-1].p + count)); 619 if (blk == first_block + count) 620 count++; 621 else 622 break; 623 } 624 if (err != -EAGAIN) 625 goto got_it; 626 } 627 628 /* Next simple case - plain lookup or failed read of indirect block */ 629 if (!create || err == -EIO) 630 goto cleanup; 631 632 mutex_lock(&ei->truncate_mutex); 633 /* 634 * If the indirect block is missing while we are reading 635 * the chain(ext3_get_branch() returns -EAGAIN err), or 636 * if the chain has been changed after we grab the semaphore, 637 * (either because another process truncated this branch, or 638 * another get_block allocated this branch) re-grab the chain to see if 639 * the request block has been allocated or not. 640 * 641 * Since we already block the truncate/other get_block 642 * at this point, we will have the current copy of the chain when we 643 * splice the branch into the tree. 644 */ 645 if (err == -EAGAIN || !verify_chain(chain, partial)) { 646 while (partial > chain) { 647 brelse(partial->bh); 648 partial--; 649 } 650 partial = ext2_get_branch(inode, depth, offsets, chain, &err); 651 if (!partial) { 652 count++; 653 mutex_unlock(&ei->truncate_mutex); 654 if (err) 655 goto cleanup; 656 clear_buffer_new(bh_result); 657 goto got_it; 658 } 659 } 660 661 /* 662 * Okay, we need to do block allocation. Lazily initialize the block 663 * allocation info here if necessary 664 */ 665 if (S_ISREG(inode->i_mode) && (!ei->i_block_alloc_info)) 666 ext2_init_block_alloc_info(inode); 667 668 goal = ext2_find_goal(inode, iblock, partial); 669 670 /* the number of blocks need to allocate for [d,t]indirect blocks */ 671 indirect_blks = (chain + depth) - partial - 1; 672 /* 673 * Next look up the indirect map to count the totoal number of 674 * direct blocks to allocate for this branch. 675 */ 676 count = ext2_blks_to_allocate(partial, indirect_blks, 677 maxblocks, blocks_to_boundary); 678 /* 679 * XXX ???? Block out ext2_truncate while we alter the tree 680 */ 681 err = ext2_alloc_branch(inode, indirect_blks, &count, goal, 682 offsets + (partial - chain), partial); 683 684 if (err) { 685 mutex_unlock(&ei->truncate_mutex); 686 goto cleanup; 687 } 688 689 if (ext2_use_xip(inode->i_sb)) { 690 /* 691 * we need to clear the block 692 */ 693 err = ext2_clear_xip_target (inode, 694 le32_to_cpu(chain[depth-1].key)); 695 if (err) { 696 mutex_unlock(&ei->truncate_mutex); 697 goto cleanup; 698 } 699 } 700 701 ext2_splice_branch(inode, iblock, partial, indirect_blks, count); 702 mutex_unlock(&ei->truncate_mutex); 703 set_buffer_new(bh_result); 704 got_it: 705 map_bh(bh_result, inode->i_sb, le32_to_cpu(chain[depth-1].key)); 706 if (count > blocks_to_boundary) 707 set_buffer_boundary(bh_result); 708 err = count; 709 /* Clean up and exit */ 710 partial = chain + depth - 1; /* the whole chain */ 711 cleanup: 712 while (partial > chain) { 713 brelse(partial->bh); 714 partial--; 715 } 716 return err; 717 } 718 719 int ext2_get_block(struct inode *inode, sector_t iblock, struct buffer_head *bh_result, int create) 720 { 721 unsigned max_blocks = bh_result->b_size >> inode->i_blkbits; 722 int ret = ext2_get_blocks(inode, iblock, max_blocks, 723 bh_result, create); 724 if (ret > 0) { 725 bh_result->b_size = (ret << inode->i_blkbits); 726 ret = 0; 727 } 728 return ret; 729 730 } 731 732 int ext2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, 733 u64 start, u64 len) 734 { 735 return generic_block_fiemap(inode, fieinfo, start, len, 736 ext2_get_block); 737 } 738 739 static int ext2_writepage(struct page *page, struct writeback_control *wbc) 740 { 741 return block_write_full_page(page, ext2_get_block, wbc); 742 } 743 744 static int ext2_readpage(struct file *file, struct page *page) 745 { 746 return mpage_readpage(page, ext2_get_block); 747 } 748 749 static int 750 ext2_readpages(struct file *file, struct address_space *mapping, 751 struct list_head *pages, unsigned nr_pages) 752 { 753 return mpage_readpages(mapping, pages, nr_pages, ext2_get_block); 754 } 755 756 int __ext2_write_begin(struct file *file, struct address_space *mapping, 757 loff_t pos, unsigned len, unsigned flags, 758 struct page **pagep, void **fsdata) 759 { 760 return block_write_begin(file, mapping, pos, len, flags, pagep, fsdata, 761 ext2_get_block); 762 } 763 764 static int 765 ext2_write_begin(struct file *file, struct address_space *mapping, 766 loff_t pos, unsigned len, unsigned flags, 767 struct page **pagep, void **fsdata) 768 { 769 *pagep = NULL; 770 return __ext2_write_begin(file, mapping, pos, len, flags, pagep,fsdata); 771 } 772 773 static int 774 ext2_nobh_write_begin(struct file *file, struct address_space *mapping, 775 loff_t pos, unsigned len, unsigned flags, 776 struct page **pagep, void **fsdata) 777 { 778 /* 779 * Dir-in-pagecache still uses ext2_write_begin. Would have to rework 780 * directory handling code to pass around offsets rather than struct 781 * pages in order to make this work easily. 782 */ 783 return nobh_write_begin(file, mapping, pos, len, flags, pagep, fsdata, 784 ext2_get_block); 785 } 786 787 static int ext2_nobh_writepage(struct page *page, 788 struct writeback_control *wbc) 789 { 790 return nobh_writepage(page, ext2_get_block, wbc); 791 } 792 793 static sector_t ext2_bmap(struct address_space *mapping, sector_t block) 794 { 795 return generic_block_bmap(mapping,block,ext2_get_block); 796 } 797 798 static ssize_t 799 ext2_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov, 800 loff_t offset, unsigned long nr_segs) 801 { 802 struct file *file = iocb->ki_filp; 803 struct inode *inode = file->f_mapping->host; 804 805 return blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev, iov, 806 offset, nr_segs, ext2_get_block, NULL); 807 } 808 809 static int 810 ext2_writepages(struct address_space *mapping, struct writeback_control *wbc) 811 { 812 return mpage_writepages(mapping, wbc, ext2_get_block); 813 } 814 815 const struct address_space_operations ext2_aops = { 816 .readpage = ext2_readpage, 817 .readpages = ext2_readpages, 818 .writepage = ext2_writepage, 819 .sync_page = block_sync_page, 820 .write_begin = ext2_write_begin, 821 .write_end = generic_write_end, 822 .bmap = ext2_bmap, 823 .direct_IO = ext2_direct_IO, 824 .writepages = ext2_writepages, 825 .migratepage = buffer_migrate_page, 826 .is_partially_uptodate = block_is_partially_uptodate, 827 .error_remove_page = generic_error_remove_page, 828 }; 829 830 const struct address_space_operations ext2_aops_xip = { 831 .bmap = ext2_bmap, 832 .get_xip_mem = ext2_get_xip_mem, 833 }; 834 835 const struct address_space_operations ext2_nobh_aops = { 836 .readpage = ext2_readpage, 837 .readpages = ext2_readpages, 838 .writepage = ext2_nobh_writepage, 839 .sync_page = block_sync_page, 840 .write_begin = ext2_nobh_write_begin, 841 .write_end = nobh_write_end, 842 .bmap = ext2_bmap, 843 .direct_IO = ext2_direct_IO, 844 .writepages = ext2_writepages, 845 .migratepage = buffer_migrate_page, 846 .error_remove_page = generic_error_remove_page, 847 }; 848 849 /* 850 * Probably it should be a library function... search for first non-zero word 851 * or memcmp with zero_page, whatever is better for particular architecture. 852 * Linus? 853 */ 854 static inline int all_zeroes(__le32 *p, __le32 *q) 855 { 856 while (p < q) 857 if (*p++) 858 return 0; 859 return 1; 860 } 861 862 /** 863 * ext2_find_shared - find the indirect blocks for partial truncation. 864 * @inode: inode in question 865 * @depth: depth of the affected branch 866 * @offsets: offsets of pointers in that branch (see ext2_block_to_path) 867 * @chain: place to store the pointers to partial indirect blocks 868 * @top: place to the (detached) top of branch 869 * 870 * This is a helper function used by ext2_truncate(). 871 * 872 * When we do truncate() we may have to clean the ends of several indirect 873 * blocks but leave the blocks themselves alive. Block is partially 874 * truncated if some data below the new i_size is refered from it (and 875 * it is on the path to the first completely truncated data block, indeed). 876 * We have to free the top of that path along with everything to the right 877 * of the path. Since no allocation past the truncation point is possible 878 * until ext2_truncate() finishes, we may safely do the latter, but top 879 * of branch may require special attention - pageout below the truncation 880 * point might try to populate it. 881 * 882 * We atomically detach the top of branch from the tree, store the block 883 * number of its root in *@top, pointers to buffer_heads of partially 884 * truncated blocks - in @chain[].bh and pointers to their last elements 885 * that should not be removed - in @chain[].p. Return value is the pointer 886 * to last filled element of @chain. 887 * 888 * The work left to caller to do the actual freeing of subtrees: 889 * a) free the subtree starting from *@top 890 * b) free the subtrees whose roots are stored in 891 * (@chain[i].p+1 .. end of @chain[i].bh->b_data) 892 * c) free the subtrees growing from the inode past the @chain[0].p 893 * (no partially truncated stuff there). 894 */ 895 896 static Indirect *ext2_find_shared(struct inode *inode, 897 int depth, 898 int offsets[4], 899 Indirect chain[4], 900 __le32 *top) 901 { 902 Indirect *partial, *p; 903 int k, err; 904 905 *top = 0; 906 for (k = depth; k > 1 && !offsets[k-1]; k--) 907 ; 908 partial = ext2_get_branch(inode, k, offsets, chain, &err); 909 if (!partial) 910 partial = chain + k-1; 911 /* 912 * If the branch acquired continuation since we've looked at it - 913 * fine, it should all survive and (new) top doesn't belong to us. 914 */ 915 write_lock(&EXT2_I(inode)->i_meta_lock); 916 if (!partial->key && *partial->p) { 917 write_unlock(&EXT2_I(inode)->i_meta_lock); 918 goto no_top; 919 } 920 for (p=partial; p>chain && all_zeroes((__le32*)p->bh->b_data,p->p); p--) 921 ; 922 /* 923 * OK, we've found the last block that must survive. The rest of our 924 * branch should be detached before unlocking. However, if that rest 925 * of branch is all ours and does not grow immediately from the inode 926 * it's easier to cheat and just decrement partial->p. 927 */ 928 if (p == chain + k - 1 && p > chain) { 929 p->p--; 930 } else { 931 *top = *p->p; 932 *p->p = 0; 933 } 934 write_unlock(&EXT2_I(inode)->i_meta_lock); 935 936 while(partial > p) 937 { 938 brelse(partial->bh); 939 partial--; 940 } 941 no_top: 942 return partial; 943 } 944 945 /** 946 * ext2_free_data - free a list of data blocks 947 * @inode: inode we are dealing with 948 * @p: array of block numbers 949 * @q: points immediately past the end of array 950 * 951 * We are freeing all blocks refered from that array (numbers are 952 * stored as little-endian 32-bit) and updating @inode->i_blocks 953 * appropriately. 954 */ 955 static inline void ext2_free_data(struct inode *inode, __le32 *p, __le32 *q) 956 { 957 unsigned long block_to_free = 0, count = 0; 958 unsigned long nr; 959 960 for ( ; p < q ; p++) { 961 nr = le32_to_cpu(*p); 962 if (nr) { 963 *p = 0; 964 /* accumulate blocks to free if they're contiguous */ 965 if (count == 0) 966 goto free_this; 967 else if (block_to_free == nr - count) 968 count++; 969 else { 970 mark_inode_dirty(inode); 971 ext2_free_blocks (inode, block_to_free, count); 972 free_this: 973 block_to_free = nr; 974 count = 1; 975 } 976 } 977 } 978 if (count > 0) { 979 mark_inode_dirty(inode); 980 ext2_free_blocks (inode, block_to_free, count); 981 } 982 } 983 984 /** 985 * ext2_free_branches - free an array of branches 986 * @inode: inode we are dealing with 987 * @p: array of block numbers 988 * @q: pointer immediately past the end of array 989 * @depth: depth of the branches to free 990 * 991 * We are freeing all blocks refered from these branches (numbers are 992 * stored as little-endian 32-bit) and updating @inode->i_blocks 993 * appropriately. 994 */ 995 static void ext2_free_branches(struct inode *inode, __le32 *p, __le32 *q, int depth) 996 { 997 struct buffer_head * bh; 998 unsigned long nr; 999 1000 if (depth--) { 1001 int addr_per_block = EXT2_ADDR_PER_BLOCK(inode->i_sb); 1002 for ( ; p < q ; p++) { 1003 nr = le32_to_cpu(*p); 1004 if (!nr) 1005 continue; 1006 *p = 0; 1007 bh = sb_bread(inode->i_sb, nr); 1008 /* 1009 * A read failure? Report error and clear slot 1010 * (should be rare). 1011 */ 1012 if (!bh) { 1013 ext2_error(inode->i_sb, "ext2_free_branches", 1014 "Read failure, inode=%ld, block=%ld", 1015 inode->i_ino, nr); 1016 continue; 1017 } 1018 ext2_free_branches(inode, 1019 (__le32*)bh->b_data, 1020 (__le32*)bh->b_data + addr_per_block, 1021 depth); 1022 bforget(bh); 1023 ext2_free_blocks(inode, nr, 1); 1024 mark_inode_dirty(inode); 1025 } 1026 } else 1027 ext2_free_data(inode, p, q); 1028 } 1029 1030 void ext2_truncate(struct inode *inode) 1031 { 1032 __le32 *i_data = EXT2_I(inode)->i_data; 1033 struct ext2_inode_info *ei = EXT2_I(inode); 1034 int addr_per_block = EXT2_ADDR_PER_BLOCK(inode->i_sb); 1035 int offsets[4]; 1036 Indirect chain[4]; 1037 Indirect *partial; 1038 __le32 nr = 0; 1039 int n; 1040 long iblock; 1041 unsigned blocksize; 1042 1043 if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || 1044 S_ISLNK(inode->i_mode))) 1045 return; 1046 if (ext2_inode_is_fast_symlink(inode)) 1047 return; 1048 if (IS_APPEND(inode) || IS_IMMUTABLE(inode)) 1049 return; 1050 1051 blocksize = inode->i_sb->s_blocksize; 1052 iblock = (inode->i_size + blocksize-1) 1053 >> EXT2_BLOCK_SIZE_BITS(inode->i_sb); 1054 1055 if (mapping_is_xip(inode->i_mapping)) 1056 xip_truncate_page(inode->i_mapping, inode->i_size); 1057 else if (test_opt(inode->i_sb, NOBH)) 1058 nobh_truncate_page(inode->i_mapping, 1059 inode->i_size, ext2_get_block); 1060 else 1061 block_truncate_page(inode->i_mapping, 1062 inode->i_size, ext2_get_block); 1063 1064 n = ext2_block_to_path(inode, iblock, offsets, NULL); 1065 if (n == 0) 1066 return; 1067 1068 /* 1069 * From here we block out all ext2_get_block() callers who want to 1070 * modify the block allocation tree. 1071 */ 1072 mutex_lock(&ei->truncate_mutex); 1073 1074 if (n == 1) { 1075 ext2_free_data(inode, i_data+offsets[0], 1076 i_data + EXT2_NDIR_BLOCKS); 1077 goto do_indirects; 1078 } 1079 1080 partial = ext2_find_shared(inode, n, offsets, chain, &nr); 1081 /* Kill the top of shared branch (already detached) */ 1082 if (nr) { 1083 if (partial == chain) 1084 mark_inode_dirty(inode); 1085 else 1086 mark_buffer_dirty_inode(partial->bh, inode); 1087 ext2_free_branches(inode, &nr, &nr+1, (chain+n-1) - partial); 1088 } 1089 /* Clear the ends of indirect blocks on the shared branch */ 1090 while (partial > chain) { 1091 ext2_free_branches(inode, 1092 partial->p + 1, 1093 (__le32*)partial->bh->b_data+addr_per_block, 1094 (chain+n-1) - partial); 1095 mark_buffer_dirty_inode(partial->bh, inode); 1096 brelse (partial->bh); 1097 partial--; 1098 } 1099 do_indirects: 1100 /* Kill the remaining (whole) subtrees */ 1101 switch (offsets[0]) { 1102 default: 1103 nr = i_data[EXT2_IND_BLOCK]; 1104 if (nr) { 1105 i_data[EXT2_IND_BLOCK] = 0; 1106 mark_inode_dirty(inode); 1107 ext2_free_branches(inode, &nr, &nr+1, 1); 1108 } 1109 case EXT2_IND_BLOCK: 1110 nr = i_data[EXT2_DIND_BLOCK]; 1111 if (nr) { 1112 i_data[EXT2_DIND_BLOCK] = 0; 1113 mark_inode_dirty(inode); 1114 ext2_free_branches(inode, &nr, &nr+1, 2); 1115 } 1116 case EXT2_DIND_BLOCK: 1117 nr = i_data[EXT2_TIND_BLOCK]; 1118 if (nr) { 1119 i_data[EXT2_TIND_BLOCK] = 0; 1120 mark_inode_dirty(inode); 1121 ext2_free_branches(inode, &nr, &nr+1, 3); 1122 } 1123 case EXT2_TIND_BLOCK: 1124 ; 1125 } 1126 1127 ext2_discard_reservation(inode); 1128 1129 mutex_unlock(&ei->truncate_mutex); 1130 inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC; 1131 if (inode_needs_sync(inode)) { 1132 sync_mapping_buffers(inode->i_mapping); 1133 ext2_sync_inode (inode); 1134 } else { 1135 mark_inode_dirty(inode); 1136 } 1137 } 1138 1139 static struct ext2_inode *ext2_get_inode(struct super_block *sb, ino_t ino, 1140 struct buffer_head **p) 1141 { 1142 struct buffer_head * bh; 1143 unsigned long block_group; 1144 unsigned long block; 1145 unsigned long offset; 1146 struct ext2_group_desc * gdp; 1147 1148 *p = NULL; 1149 if ((ino != EXT2_ROOT_INO && ino < EXT2_FIRST_INO(sb)) || 1150 ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count)) 1151 goto Einval; 1152 1153 block_group = (ino - 1) / EXT2_INODES_PER_GROUP(sb); 1154 gdp = ext2_get_group_desc(sb, block_group, NULL); 1155 if (!gdp) 1156 goto Egdp; 1157 /* 1158 * Figure out the offset within the block group inode table 1159 */ 1160 offset = ((ino - 1) % EXT2_INODES_PER_GROUP(sb)) * EXT2_INODE_SIZE(sb); 1161 block = le32_to_cpu(gdp->bg_inode_table) + 1162 (offset >> EXT2_BLOCK_SIZE_BITS(sb)); 1163 if (!(bh = sb_bread(sb, block))) 1164 goto Eio; 1165 1166 *p = bh; 1167 offset &= (EXT2_BLOCK_SIZE(sb) - 1); 1168 return (struct ext2_inode *) (bh->b_data + offset); 1169 1170 Einval: 1171 ext2_error(sb, "ext2_get_inode", "bad inode number: %lu", 1172 (unsigned long) ino); 1173 return ERR_PTR(-EINVAL); 1174 Eio: 1175 ext2_error(sb, "ext2_get_inode", 1176 "unable to read inode block - inode=%lu, block=%lu", 1177 (unsigned long) ino, block); 1178 Egdp: 1179 return ERR_PTR(-EIO); 1180 } 1181 1182 void ext2_set_inode_flags(struct inode *inode) 1183 { 1184 unsigned int flags = EXT2_I(inode)->i_flags; 1185 1186 inode->i_flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC); 1187 if (flags & EXT2_SYNC_FL) 1188 inode->i_flags |= S_SYNC; 1189 if (flags & EXT2_APPEND_FL) 1190 inode->i_flags |= S_APPEND; 1191 if (flags & EXT2_IMMUTABLE_FL) 1192 inode->i_flags |= S_IMMUTABLE; 1193 if (flags & EXT2_NOATIME_FL) 1194 inode->i_flags |= S_NOATIME; 1195 if (flags & EXT2_DIRSYNC_FL) 1196 inode->i_flags |= S_DIRSYNC; 1197 } 1198 1199 /* Propagate flags from i_flags to EXT2_I(inode)->i_flags */ 1200 void ext2_get_inode_flags(struct ext2_inode_info *ei) 1201 { 1202 unsigned int flags = ei->vfs_inode.i_flags; 1203 1204 ei->i_flags &= ~(EXT2_SYNC_FL|EXT2_APPEND_FL| 1205 EXT2_IMMUTABLE_FL|EXT2_NOATIME_FL|EXT2_DIRSYNC_FL); 1206 if (flags & S_SYNC) 1207 ei->i_flags |= EXT2_SYNC_FL; 1208 if (flags & S_APPEND) 1209 ei->i_flags |= EXT2_APPEND_FL; 1210 if (flags & S_IMMUTABLE) 1211 ei->i_flags |= EXT2_IMMUTABLE_FL; 1212 if (flags & S_NOATIME) 1213 ei->i_flags |= EXT2_NOATIME_FL; 1214 if (flags & S_DIRSYNC) 1215 ei->i_flags |= EXT2_DIRSYNC_FL; 1216 } 1217 1218 struct inode *ext2_iget (struct super_block *sb, unsigned long ino) 1219 { 1220 struct ext2_inode_info *ei; 1221 struct buffer_head * bh; 1222 struct ext2_inode *raw_inode; 1223 struct inode *inode; 1224 long ret = -EIO; 1225 int n; 1226 1227 inode = iget_locked(sb, ino); 1228 if (!inode) 1229 return ERR_PTR(-ENOMEM); 1230 if (!(inode->i_state & I_NEW)) 1231 return inode; 1232 1233 ei = EXT2_I(inode); 1234 ei->i_block_alloc_info = NULL; 1235 1236 raw_inode = ext2_get_inode(inode->i_sb, ino, &bh); 1237 if (IS_ERR(raw_inode)) { 1238 ret = PTR_ERR(raw_inode); 1239 goto bad_inode; 1240 } 1241 1242 inode->i_mode = le16_to_cpu(raw_inode->i_mode); 1243 inode->i_uid = (uid_t)le16_to_cpu(raw_inode->i_uid_low); 1244 inode->i_gid = (gid_t)le16_to_cpu(raw_inode->i_gid_low); 1245 if (!(test_opt (inode->i_sb, NO_UID32))) { 1246 inode->i_uid |= le16_to_cpu(raw_inode->i_uid_high) << 16; 1247 inode->i_gid |= le16_to_cpu(raw_inode->i_gid_high) << 16; 1248 } 1249 inode->i_nlink = le16_to_cpu(raw_inode->i_links_count); 1250 inode->i_size = le32_to_cpu(raw_inode->i_size); 1251 inode->i_atime.tv_sec = (signed)le32_to_cpu(raw_inode->i_atime); 1252 inode->i_ctime.tv_sec = (signed)le32_to_cpu(raw_inode->i_ctime); 1253 inode->i_mtime.tv_sec = (signed)le32_to_cpu(raw_inode->i_mtime); 1254 inode->i_atime.tv_nsec = inode->i_mtime.tv_nsec = inode->i_ctime.tv_nsec = 0; 1255 ei->i_dtime = le32_to_cpu(raw_inode->i_dtime); 1256 /* We now have enough fields to check if the inode was active or not. 1257 * This is needed because nfsd might try to access dead inodes 1258 * the test is that same one that e2fsck uses 1259 * NeilBrown 1999oct15 1260 */ 1261 if (inode->i_nlink == 0 && (inode->i_mode == 0 || ei->i_dtime)) { 1262 /* this inode is deleted */ 1263 brelse (bh); 1264 ret = -ESTALE; 1265 goto bad_inode; 1266 } 1267 inode->i_blocks = le32_to_cpu(raw_inode->i_blocks); 1268 ei->i_flags = le32_to_cpu(raw_inode->i_flags); 1269 ei->i_faddr = le32_to_cpu(raw_inode->i_faddr); 1270 ei->i_frag_no = raw_inode->i_frag; 1271 ei->i_frag_size = raw_inode->i_fsize; 1272 ei->i_file_acl = le32_to_cpu(raw_inode->i_file_acl); 1273 ei->i_dir_acl = 0; 1274 if (S_ISREG(inode->i_mode)) 1275 inode->i_size |= ((__u64)le32_to_cpu(raw_inode->i_size_high)) << 32; 1276 else 1277 ei->i_dir_acl = le32_to_cpu(raw_inode->i_dir_acl); 1278 ei->i_dtime = 0; 1279 inode->i_generation = le32_to_cpu(raw_inode->i_generation); 1280 ei->i_state = 0; 1281 ei->i_block_group = (ino - 1) / EXT2_INODES_PER_GROUP(inode->i_sb); 1282 ei->i_dir_start_lookup = 0; 1283 1284 /* 1285 * NOTE! The in-memory inode i_data array is in little-endian order 1286 * even on big-endian machines: we do NOT byteswap the block numbers! 1287 */ 1288 for (n = 0; n < EXT2_N_BLOCKS; n++) 1289 ei->i_data[n] = raw_inode->i_block[n]; 1290 1291 if (S_ISREG(inode->i_mode)) { 1292 inode->i_op = &ext2_file_inode_operations; 1293 if (ext2_use_xip(inode->i_sb)) { 1294 inode->i_mapping->a_ops = &ext2_aops_xip; 1295 inode->i_fop = &ext2_xip_file_operations; 1296 } else if (test_opt(inode->i_sb, NOBH)) { 1297 inode->i_mapping->a_ops = &ext2_nobh_aops; 1298 inode->i_fop = &ext2_file_operations; 1299 } else { 1300 inode->i_mapping->a_ops = &ext2_aops; 1301 inode->i_fop = &ext2_file_operations; 1302 } 1303 } else if (S_ISDIR(inode->i_mode)) { 1304 inode->i_op = &ext2_dir_inode_operations; 1305 inode->i_fop = &ext2_dir_operations; 1306 if (test_opt(inode->i_sb, NOBH)) 1307 inode->i_mapping->a_ops = &ext2_nobh_aops; 1308 else 1309 inode->i_mapping->a_ops = &ext2_aops; 1310 } else if (S_ISLNK(inode->i_mode)) { 1311 if (ext2_inode_is_fast_symlink(inode)) { 1312 inode->i_op = &ext2_fast_symlink_inode_operations; 1313 nd_terminate_link(ei->i_data, inode->i_size, 1314 sizeof(ei->i_data) - 1); 1315 } else { 1316 inode->i_op = &ext2_symlink_inode_operations; 1317 if (test_opt(inode->i_sb, NOBH)) 1318 inode->i_mapping->a_ops = &ext2_nobh_aops; 1319 else 1320 inode->i_mapping->a_ops = &ext2_aops; 1321 } 1322 } else { 1323 inode->i_op = &ext2_special_inode_operations; 1324 if (raw_inode->i_block[0]) 1325 init_special_inode(inode, inode->i_mode, 1326 old_decode_dev(le32_to_cpu(raw_inode->i_block[0]))); 1327 else 1328 init_special_inode(inode, inode->i_mode, 1329 new_decode_dev(le32_to_cpu(raw_inode->i_block[1]))); 1330 } 1331 brelse (bh); 1332 ext2_set_inode_flags(inode); 1333 unlock_new_inode(inode); 1334 return inode; 1335 1336 bad_inode: 1337 iget_failed(inode); 1338 return ERR_PTR(ret); 1339 } 1340 1341 static int __ext2_write_inode(struct inode *inode, int do_sync) 1342 { 1343 struct ext2_inode_info *ei = EXT2_I(inode); 1344 struct super_block *sb = inode->i_sb; 1345 ino_t ino = inode->i_ino; 1346 uid_t uid = inode->i_uid; 1347 gid_t gid = inode->i_gid; 1348 struct buffer_head * bh; 1349 struct ext2_inode * raw_inode = ext2_get_inode(sb, ino, &bh); 1350 int n; 1351 int err = 0; 1352 1353 if (IS_ERR(raw_inode)) 1354 return -EIO; 1355 1356 /* For fields not not tracking in the in-memory inode, 1357 * initialise them to zero for new inodes. */ 1358 if (ei->i_state & EXT2_STATE_NEW) 1359 memset(raw_inode, 0, EXT2_SB(sb)->s_inode_size); 1360 1361 ext2_get_inode_flags(ei); 1362 raw_inode->i_mode = cpu_to_le16(inode->i_mode); 1363 if (!(test_opt(sb, NO_UID32))) { 1364 raw_inode->i_uid_low = cpu_to_le16(low_16_bits(uid)); 1365 raw_inode->i_gid_low = cpu_to_le16(low_16_bits(gid)); 1366 /* 1367 * Fix up interoperability with old kernels. Otherwise, old inodes get 1368 * re-used with the upper 16 bits of the uid/gid intact 1369 */ 1370 if (!ei->i_dtime) { 1371 raw_inode->i_uid_high = cpu_to_le16(high_16_bits(uid)); 1372 raw_inode->i_gid_high = cpu_to_le16(high_16_bits(gid)); 1373 } else { 1374 raw_inode->i_uid_high = 0; 1375 raw_inode->i_gid_high = 0; 1376 } 1377 } else { 1378 raw_inode->i_uid_low = cpu_to_le16(fs_high2lowuid(uid)); 1379 raw_inode->i_gid_low = cpu_to_le16(fs_high2lowgid(gid)); 1380 raw_inode->i_uid_high = 0; 1381 raw_inode->i_gid_high = 0; 1382 } 1383 raw_inode->i_links_count = cpu_to_le16(inode->i_nlink); 1384 raw_inode->i_size = cpu_to_le32(inode->i_size); 1385 raw_inode->i_atime = cpu_to_le32(inode->i_atime.tv_sec); 1386 raw_inode->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec); 1387 raw_inode->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec); 1388 1389 raw_inode->i_blocks = cpu_to_le32(inode->i_blocks); 1390 raw_inode->i_dtime = cpu_to_le32(ei->i_dtime); 1391 raw_inode->i_flags = cpu_to_le32(ei->i_flags); 1392 raw_inode->i_faddr = cpu_to_le32(ei->i_faddr); 1393 raw_inode->i_frag = ei->i_frag_no; 1394 raw_inode->i_fsize = ei->i_frag_size; 1395 raw_inode->i_file_acl = cpu_to_le32(ei->i_file_acl); 1396 if (!S_ISREG(inode->i_mode)) 1397 raw_inode->i_dir_acl = cpu_to_le32(ei->i_dir_acl); 1398 else { 1399 raw_inode->i_size_high = cpu_to_le32(inode->i_size >> 32); 1400 if (inode->i_size > 0x7fffffffULL) { 1401 if (!EXT2_HAS_RO_COMPAT_FEATURE(sb, 1402 EXT2_FEATURE_RO_COMPAT_LARGE_FILE) || 1403 EXT2_SB(sb)->s_es->s_rev_level == 1404 cpu_to_le32(EXT2_GOOD_OLD_REV)) { 1405 /* If this is the first large file 1406 * created, add a flag to the superblock. 1407 */ 1408 spin_lock(&EXT2_SB(sb)->s_lock); 1409 ext2_update_dynamic_rev(sb); 1410 EXT2_SET_RO_COMPAT_FEATURE(sb, 1411 EXT2_FEATURE_RO_COMPAT_LARGE_FILE); 1412 spin_unlock(&EXT2_SB(sb)->s_lock); 1413 ext2_write_super(sb); 1414 } 1415 } 1416 } 1417 1418 raw_inode->i_generation = cpu_to_le32(inode->i_generation); 1419 if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) { 1420 if (old_valid_dev(inode->i_rdev)) { 1421 raw_inode->i_block[0] = 1422 cpu_to_le32(old_encode_dev(inode->i_rdev)); 1423 raw_inode->i_block[1] = 0; 1424 } else { 1425 raw_inode->i_block[0] = 0; 1426 raw_inode->i_block[1] = 1427 cpu_to_le32(new_encode_dev(inode->i_rdev)); 1428 raw_inode->i_block[2] = 0; 1429 } 1430 } else for (n = 0; n < EXT2_N_BLOCKS; n++) 1431 raw_inode->i_block[n] = ei->i_data[n]; 1432 mark_buffer_dirty(bh); 1433 if (do_sync) { 1434 sync_dirty_buffer(bh); 1435 if (buffer_req(bh) && !buffer_uptodate(bh)) { 1436 printk ("IO error syncing ext2 inode [%s:%08lx]\n", 1437 sb->s_id, (unsigned long) ino); 1438 err = -EIO; 1439 } 1440 } 1441 ei->i_state &= ~EXT2_STATE_NEW; 1442 brelse (bh); 1443 return err; 1444 } 1445 1446 int ext2_write_inode(struct inode *inode, struct writeback_control *wbc) 1447 { 1448 return __ext2_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL); 1449 } 1450 1451 int ext2_sync_inode(struct inode *inode) 1452 { 1453 struct writeback_control wbc = { 1454 .sync_mode = WB_SYNC_ALL, 1455 .nr_to_write = 0, /* sys_fsync did this */ 1456 }; 1457 return sync_inode(inode, &wbc); 1458 } 1459 1460 int ext2_setattr(struct dentry *dentry, struct iattr *iattr) 1461 { 1462 struct inode *inode = dentry->d_inode; 1463 int error; 1464 1465 error = inode_change_ok(inode, iattr); 1466 if (error) 1467 return error; 1468 1469 if (is_quota_modification(inode, iattr)) 1470 dquot_initialize(inode); 1471 if ((iattr->ia_valid & ATTR_UID && iattr->ia_uid != inode->i_uid) || 1472 (iattr->ia_valid & ATTR_GID && iattr->ia_gid != inode->i_gid)) { 1473 error = dquot_transfer(inode, iattr); 1474 if (error) 1475 return error; 1476 } 1477 error = inode_setattr(inode, iattr); 1478 if (!error && (iattr->ia_valid & ATTR_MODE)) 1479 error = ext2_acl_chmod(inode); 1480 return error; 1481 } 1482