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 static void ext2_truncate_blocks(struct inode *inode, loff_t offset); 58 59 static void ext2_write_failed(struct address_space *mapping, loff_t to) 60 { 61 struct inode *inode = mapping->host; 62 63 if (to > inode->i_size) { 64 truncate_pagecache(inode, to, inode->i_size); 65 ext2_truncate_blocks(inode, inode->i_size); 66 } 67 } 68 69 /* 70 * Called at the last iput() if i_nlink is zero. 71 */ 72 void ext2_evict_inode(struct inode * inode) 73 { 74 struct ext2_block_alloc_info *rsv; 75 int want_delete = 0; 76 77 if (!inode->i_nlink && !is_bad_inode(inode)) { 78 want_delete = 1; 79 dquot_initialize(inode); 80 } else { 81 dquot_drop(inode); 82 } 83 84 truncate_inode_pages(&inode->i_data, 0); 85 86 if (want_delete) { 87 /* set dtime */ 88 EXT2_I(inode)->i_dtime = get_seconds(); 89 mark_inode_dirty(inode); 90 __ext2_write_inode(inode, inode_needs_sync(inode)); 91 /* truncate to 0 */ 92 inode->i_size = 0; 93 if (inode->i_blocks) 94 ext2_truncate_blocks(inode, 0); 95 } 96 97 invalidate_inode_buffers(inode); 98 end_writeback(inode); 99 100 ext2_discard_reservation(inode); 101 rsv = EXT2_I(inode)->i_block_alloc_info; 102 EXT2_I(inode)->i_block_alloc_info = NULL; 103 if (unlikely(rsv)) 104 kfree(rsv); 105 106 if (want_delete) 107 ext2_free_inode(inode); 108 } 109 110 typedef struct { 111 __le32 *p; 112 __le32 key; 113 struct buffer_head *bh; 114 } Indirect; 115 116 static inline void add_chain(Indirect *p, struct buffer_head *bh, __le32 *v) 117 { 118 p->key = *(p->p = v); 119 p->bh = bh; 120 } 121 122 static inline int verify_chain(Indirect *from, Indirect *to) 123 { 124 while (from <= to && from->key == *from->p) 125 from++; 126 return (from > to); 127 } 128 129 /** 130 * ext2_block_to_path - parse the block number into array of offsets 131 * @inode: inode in question (we are only interested in its superblock) 132 * @i_block: block number to be parsed 133 * @offsets: array to store the offsets in 134 * @boundary: set this non-zero if the referred-to block is likely to be 135 * followed (on disk) by an indirect block. 136 * To store the locations of file's data ext2 uses a data structure common 137 * for UNIX filesystems - tree of pointers anchored in the inode, with 138 * data blocks at leaves and indirect blocks in intermediate nodes. 139 * This function translates the block number into path in that tree - 140 * return value is the path length and @offsets[n] is the offset of 141 * pointer to (n+1)th node in the nth one. If @block is out of range 142 * (negative or too large) warning is printed and zero returned. 143 * 144 * Note: function doesn't find node addresses, so no IO is needed. All 145 * we need to know is the capacity of indirect blocks (taken from the 146 * inode->i_sb). 147 */ 148 149 /* 150 * Portability note: the last comparison (check that we fit into triple 151 * indirect block) is spelled differently, because otherwise on an 152 * architecture with 32-bit longs and 8Kb pages we might get into trouble 153 * if our filesystem had 8Kb blocks. We might use long long, but that would 154 * kill us on x86. Oh, well, at least the sign propagation does not matter - 155 * i_block would have to be negative in the very beginning, so we would not 156 * get there at all. 157 */ 158 159 static int ext2_block_to_path(struct inode *inode, 160 long i_block, int offsets[4], int *boundary) 161 { 162 int ptrs = EXT2_ADDR_PER_BLOCK(inode->i_sb); 163 int ptrs_bits = EXT2_ADDR_PER_BLOCK_BITS(inode->i_sb); 164 const long direct_blocks = EXT2_NDIR_BLOCKS, 165 indirect_blocks = ptrs, 166 double_blocks = (1 << (ptrs_bits * 2)); 167 int n = 0; 168 int final = 0; 169 170 if (i_block < 0) { 171 ext2_msg(inode->i_sb, KERN_WARNING, 172 "warning: %s: block < 0", __func__); 173 } else if (i_block < direct_blocks) { 174 offsets[n++] = i_block; 175 final = direct_blocks; 176 } else if ( (i_block -= direct_blocks) < indirect_blocks) { 177 offsets[n++] = EXT2_IND_BLOCK; 178 offsets[n++] = i_block; 179 final = ptrs; 180 } else if ((i_block -= indirect_blocks) < double_blocks) { 181 offsets[n++] = EXT2_DIND_BLOCK; 182 offsets[n++] = i_block >> ptrs_bits; 183 offsets[n++] = i_block & (ptrs - 1); 184 final = ptrs; 185 } else if (((i_block -= double_blocks) >> (ptrs_bits * 2)) < ptrs) { 186 offsets[n++] = EXT2_TIND_BLOCK; 187 offsets[n++] = i_block >> (ptrs_bits * 2); 188 offsets[n++] = (i_block >> ptrs_bits) & (ptrs - 1); 189 offsets[n++] = i_block & (ptrs - 1); 190 final = ptrs; 191 } else { 192 ext2_msg(inode->i_sb, KERN_WARNING, 193 "warning: %s: block is too big", __func__); 194 } 195 if (boundary) 196 *boundary = final - 1 - (i_block & (ptrs - 1)); 197 198 return n; 199 } 200 201 /** 202 * ext2_get_branch - read the chain of indirect blocks leading to data 203 * @inode: inode in question 204 * @depth: depth of the chain (1 - direct pointer, etc.) 205 * @offsets: offsets of pointers in inode/indirect blocks 206 * @chain: place to store the result 207 * @err: here we store the error value 208 * 209 * Function fills the array of triples <key, p, bh> and returns %NULL 210 * if everything went OK or the pointer to the last filled triple 211 * (incomplete one) otherwise. Upon the return chain[i].key contains 212 * the number of (i+1)-th block in the chain (as it is stored in memory, 213 * i.e. little-endian 32-bit), chain[i].p contains the address of that 214 * number (it points into struct inode for i==0 and into the bh->b_data 215 * for i>0) and chain[i].bh points to the buffer_head of i-th indirect 216 * block for i>0 and NULL for i==0. In other words, it holds the block 217 * numbers of the chain, addresses they were taken from (and where we can 218 * verify that chain did not change) and buffer_heads hosting these 219 * numbers. 220 * 221 * Function stops when it stumbles upon zero pointer (absent block) 222 * (pointer to last triple returned, *@err == 0) 223 * or when it gets an IO error reading an indirect block 224 * (ditto, *@err == -EIO) 225 * or when it notices that chain had been changed while it was reading 226 * (ditto, *@err == -EAGAIN) 227 * or when it reads all @depth-1 indirect blocks successfully and finds 228 * the whole chain, all way to the data (returns %NULL, *err == 0). 229 */ 230 static Indirect *ext2_get_branch(struct inode *inode, 231 int depth, 232 int *offsets, 233 Indirect chain[4], 234 int *err) 235 { 236 struct super_block *sb = inode->i_sb; 237 Indirect *p = chain; 238 struct buffer_head *bh; 239 240 *err = 0; 241 /* i_data is not going away, no lock needed */ 242 add_chain (chain, NULL, EXT2_I(inode)->i_data + *offsets); 243 if (!p->key) 244 goto no_block; 245 while (--depth) { 246 bh = sb_bread(sb, le32_to_cpu(p->key)); 247 if (!bh) 248 goto failure; 249 read_lock(&EXT2_I(inode)->i_meta_lock); 250 if (!verify_chain(chain, p)) 251 goto changed; 252 add_chain(++p, bh, (__le32*)bh->b_data + *++offsets); 253 read_unlock(&EXT2_I(inode)->i_meta_lock); 254 if (!p->key) 255 goto no_block; 256 } 257 return NULL; 258 259 changed: 260 read_unlock(&EXT2_I(inode)->i_meta_lock); 261 brelse(bh); 262 *err = -EAGAIN; 263 goto no_block; 264 failure: 265 *err = -EIO; 266 no_block: 267 return p; 268 } 269 270 /** 271 * ext2_find_near - find a place for allocation with sufficient locality 272 * @inode: owner 273 * @ind: descriptor of indirect block. 274 * 275 * This function returns the preferred place for block allocation. 276 * It is used when heuristic for sequential allocation fails. 277 * Rules are: 278 * + if there is a block to the left of our position - allocate near it. 279 * + if pointer will live in indirect block - allocate near that block. 280 * + if pointer will live in inode - allocate in the same cylinder group. 281 * 282 * In the latter case we colour the starting block by the callers PID to 283 * prevent it from clashing with concurrent allocations for a different inode 284 * in the same block group. The PID is used here so that functionally related 285 * files will be close-by on-disk. 286 * 287 * Caller must make sure that @ind is valid and will stay that way. 288 */ 289 290 static ext2_fsblk_t ext2_find_near(struct inode *inode, Indirect *ind) 291 { 292 struct ext2_inode_info *ei = EXT2_I(inode); 293 __le32 *start = ind->bh ? (__le32 *) ind->bh->b_data : ei->i_data; 294 __le32 *p; 295 ext2_fsblk_t bg_start; 296 ext2_fsblk_t colour; 297 298 /* Try to find previous block */ 299 for (p = ind->p - 1; p >= start; p--) 300 if (*p) 301 return le32_to_cpu(*p); 302 303 /* No such thing, so let's try location of indirect block */ 304 if (ind->bh) 305 return ind->bh->b_blocknr; 306 307 /* 308 * It is going to be referred from inode itself? OK, just put it into 309 * the same cylinder group then. 310 */ 311 bg_start = ext2_group_first_block_no(inode->i_sb, ei->i_block_group); 312 colour = (current->pid % 16) * 313 (EXT2_BLOCKS_PER_GROUP(inode->i_sb) / 16); 314 return bg_start + colour; 315 } 316 317 /** 318 * ext2_find_goal - find a preferred place for allocation. 319 * @inode: owner 320 * @block: block we want 321 * @partial: pointer to the last triple within a chain 322 * 323 * Returns preferred place for a block (the goal). 324 */ 325 326 static inline ext2_fsblk_t ext2_find_goal(struct inode *inode, long block, 327 Indirect *partial) 328 { 329 struct ext2_block_alloc_info *block_i; 330 331 block_i = EXT2_I(inode)->i_block_alloc_info; 332 333 /* 334 * try the heuristic for sequential allocation, 335 * failing that at least try to get decent locality. 336 */ 337 if (block_i && (block == block_i->last_alloc_logical_block + 1) 338 && (block_i->last_alloc_physical_block != 0)) { 339 return block_i->last_alloc_physical_block + 1; 340 } 341 342 return ext2_find_near(inode, partial); 343 } 344 345 /** 346 * ext2_blks_to_allocate: Look up the block map and count the number 347 * of direct blocks need to be allocated for the given branch. 348 * 349 * @branch: chain of indirect blocks 350 * @k: number of blocks need for indirect blocks 351 * @blks: number of data blocks to be mapped. 352 * @blocks_to_boundary: the offset in the indirect block 353 * 354 * return the total number of blocks to be allocate, including the 355 * direct and indirect blocks. 356 */ 357 static int 358 ext2_blks_to_allocate(Indirect * branch, int k, unsigned long blks, 359 int blocks_to_boundary) 360 { 361 unsigned long count = 0; 362 363 /* 364 * Simple case, [t,d]Indirect block(s) has not allocated yet 365 * then it's clear blocks on that path have not allocated 366 */ 367 if (k > 0) { 368 /* right now don't hanel cross boundary allocation */ 369 if (blks < blocks_to_boundary + 1) 370 count += blks; 371 else 372 count += blocks_to_boundary + 1; 373 return count; 374 } 375 376 count++; 377 while (count < blks && count <= blocks_to_boundary 378 && le32_to_cpu(*(branch[0].p + count)) == 0) { 379 count++; 380 } 381 return count; 382 } 383 384 /** 385 * ext2_alloc_blocks: multiple allocate blocks needed for a branch 386 * @indirect_blks: the number of blocks need to allocate for indirect 387 * blocks 388 * 389 * @new_blocks: on return it will store the new block numbers for 390 * the indirect blocks(if needed) and the first direct block, 391 * @blks: on return it will store the total number of allocated 392 * direct blocks 393 */ 394 static int ext2_alloc_blocks(struct inode *inode, 395 ext2_fsblk_t goal, int indirect_blks, int blks, 396 ext2_fsblk_t new_blocks[4], int *err) 397 { 398 int target, i; 399 unsigned long count = 0; 400 int index = 0; 401 ext2_fsblk_t current_block = 0; 402 int ret = 0; 403 404 /* 405 * Here we try to allocate the requested multiple blocks at once, 406 * on a best-effort basis. 407 * To build a branch, we should allocate blocks for 408 * the indirect blocks(if not allocated yet), and at least 409 * the first direct block of this branch. That's the 410 * minimum number of blocks need to allocate(required) 411 */ 412 target = blks + indirect_blks; 413 414 while (1) { 415 count = target; 416 /* allocating blocks for indirect blocks and direct blocks */ 417 current_block = ext2_new_blocks(inode,goal,&count,err); 418 if (*err) 419 goto failed_out; 420 421 target -= count; 422 /* allocate blocks for indirect blocks */ 423 while (index < indirect_blks && count) { 424 new_blocks[index++] = current_block++; 425 count--; 426 } 427 428 if (count > 0) 429 break; 430 } 431 432 /* save the new block number for the first direct block */ 433 new_blocks[index] = current_block; 434 435 /* total number of blocks allocated for direct blocks */ 436 ret = count; 437 *err = 0; 438 return ret; 439 failed_out: 440 for (i = 0; i <index; i++) 441 ext2_free_blocks(inode, new_blocks[i], 1); 442 if (index) 443 mark_inode_dirty(inode); 444 return ret; 445 } 446 447 /** 448 * ext2_alloc_branch - allocate and set up a chain of blocks. 449 * @inode: owner 450 * @num: depth of the chain (number of blocks to allocate) 451 * @offsets: offsets (in the blocks) to store the pointers to next. 452 * @branch: place to store the chain in. 453 * 454 * This function allocates @num blocks, zeroes out all but the last one, 455 * links them into chain and (if we are synchronous) writes them to disk. 456 * In other words, it prepares a branch that can be spliced onto the 457 * inode. It stores the information about that chain in the branch[], in 458 * the same format as ext2_get_branch() would do. We are calling it after 459 * we had read the existing part of chain and partial points to the last 460 * triple of that (one with zero ->key). Upon the exit we have the same 461 * picture as after the successful ext2_get_block(), except that in one 462 * place chain is disconnected - *branch->p is still zero (we did not 463 * set the last link), but branch->key contains the number that should 464 * be placed into *branch->p to fill that gap. 465 * 466 * If allocation fails we free all blocks we've allocated (and forget 467 * their buffer_heads) and return the error value the from failed 468 * ext2_alloc_block() (normally -ENOSPC). Otherwise we set the chain 469 * as described above and return 0. 470 */ 471 472 static int ext2_alloc_branch(struct inode *inode, 473 int indirect_blks, int *blks, ext2_fsblk_t goal, 474 int *offsets, Indirect *branch) 475 { 476 int blocksize = inode->i_sb->s_blocksize; 477 int i, n = 0; 478 int err = 0; 479 struct buffer_head *bh; 480 int num; 481 ext2_fsblk_t new_blocks[4]; 482 ext2_fsblk_t current_block; 483 484 num = ext2_alloc_blocks(inode, goal, indirect_blks, 485 *blks, new_blocks, &err); 486 if (err) 487 return err; 488 489 branch[0].key = cpu_to_le32(new_blocks[0]); 490 /* 491 * metadata blocks and data blocks are allocated. 492 */ 493 for (n = 1; n <= indirect_blks; n++) { 494 /* 495 * Get buffer_head for parent block, zero it out 496 * and set the pointer to new one, then send 497 * parent to disk. 498 */ 499 bh = sb_getblk(inode->i_sb, new_blocks[n-1]); 500 branch[n].bh = bh; 501 lock_buffer(bh); 502 memset(bh->b_data, 0, blocksize); 503 branch[n].p = (__le32 *) bh->b_data + offsets[n]; 504 branch[n].key = cpu_to_le32(new_blocks[n]); 505 *branch[n].p = branch[n].key; 506 if ( n == indirect_blks) { 507 current_block = new_blocks[n]; 508 /* 509 * End of chain, update the last new metablock of 510 * the chain to point to the new allocated 511 * data blocks numbers 512 */ 513 for (i=1; i < num; i++) 514 *(branch[n].p + i) = cpu_to_le32(++current_block); 515 } 516 set_buffer_uptodate(bh); 517 unlock_buffer(bh); 518 mark_buffer_dirty_inode(bh, inode); 519 /* We used to sync bh here if IS_SYNC(inode). 520 * But we now rely upon generic_write_sync() 521 * and b_inode_buffers. But not for directories. 522 */ 523 if (S_ISDIR(inode->i_mode) && IS_DIRSYNC(inode)) 524 sync_dirty_buffer(bh); 525 } 526 *blks = num; 527 return err; 528 } 529 530 /** 531 * ext2_splice_branch - splice the allocated branch onto inode. 532 * @inode: owner 533 * @block: (logical) number of block we are adding 534 * @where: location of missing link 535 * @num: number of indirect blocks we are adding 536 * @blks: number of direct blocks we are adding 537 * 538 * This function fills the missing link and does all housekeeping needed in 539 * inode (->i_blocks, etc.). In case of success we end up with the full 540 * chain to new block and return 0. 541 */ 542 static void ext2_splice_branch(struct inode *inode, 543 long block, Indirect *where, int num, int blks) 544 { 545 int i; 546 struct ext2_block_alloc_info *block_i; 547 ext2_fsblk_t current_block; 548 549 block_i = EXT2_I(inode)->i_block_alloc_info; 550 551 /* XXX LOCKING probably should have i_meta_lock ?*/ 552 /* That's it */ 553 554 *where->p = where->key; 555 556 /* 557 * Update the host buffer_head or inode to point to more just allocated 558 * direct blocks blocks 559 */ 560 if (num == 0 && blks > 1) { 561 current_block = le32_to_cpu(where->key) + 1; 562 for (i = 1; i < blks; i++) 563 *(where->p + i ) = cpu_to_le32(current_block++); 564 } 565 566 /* 567 * update the most recently allocated logical & physical block 568 * in i_block_alloc_info, to assist find the proper goal block for next 569 * allocation 570 */ 571 if (block_i) { 572 block_i->last_alloc_logical_block = block + blks - 1; 573 block_i->last_alloc_physical_block = 574 le32_to_cpu(where[num].key) + blks - 1; 575 } 576 577 /* We are done with atomic stuff, now do the rest of housekeeping */ 578 579 /* had we spliced it onto indirect block? */ 580 if (where->bh) 581 mark_buffer_dirty_inode(where->bh, inode); 582 583 inode->i_ctime = CURRENT_TIME_SEC; 584 mark_inode_dirty(inode); 585 } 586 587 /* 588 * Allocation strategy is simple: if we have to allocate something, we will 589 * have to go the whole way to leaf. So let's do it before attaching anything 590 * to tree, set linkage between the newborn blocks, write them if sync is 591 * required, recheck the path, free and repeat if check fails, otherwise 592 * set the last missing link (that will protect us from any truncate-generated 593 * removals - all blocks on the path are immune now) and possibly force the 594 * write on the parent block. 595 * That has a nice additional property: no special recovery from the failed 596 * allocations is needed - we simply release blocks and do not touch anything 597 * reachable from inode. 598 * 599 * `handle' can be NULL if create == 0. 600 * 601 * return > 0, # of blocks mapped or allocated. 602 * return = 0, if plain lookup failed. 603 * return < 0, error case. 604 */ 605 static int ext2_get_blocks(struct inode *inode, 606 sector_t iblock, unsigned long maxblocks, 607 struct buffer_head *bh_result, 608 int create) 609 { 610 int err = -EIO; 611 int offsets[4]; 612 Indirect chain[4]; 613 Indirect *partial; 614 ext2_fsblk_t goal; 615 int indirect_blks; 616 int blocks_to_boundary = 0; 617 int depth; 618 struct ext2_inode_info *ei = EXT2_I(inode); 619 int count = 0; 620 ext2_fsblk_t first_block = 0; 621 622 depth = ext2_block_to_path(inode,iblock,offsets,&blocks_to_boundary); 623 624 if (depth == 0) 625 return (err); 626 627 partial = ext2_get_branch(inode, depth, offsets, chain, &err); 628 /* Simplest case - block found, no allocation needed */ 629 if (!partial) { 630 first_block = le32_to_cpu(chain[depth - 1].key); 631 clear_buffer_new(bh_result); /* What's this do? */ 632 count++; 633 /*map more blocks*/ 634 while (count < maxblocks && count <= blocks_to_boundary) { 635 ext2_fsblk_t blk; 636 637 if (!verify_chain(chain, chain + depth - 1)) { 638 /* 639 * Indirect block might be removed by 640 * truncate while we were reading it. 641 * Handling of that case: forget what we've 642 * got now, go to reread. 643 */ 644 err = -EAGAIN; 645 count = 0; 646 break; 647 } 648 blk = le32_to_cpu(*(chain[depth-1].p + count)); 649 if (blk == first_block + count) 650 count++; 651 else 652 break; 653 } 654 if (err != -EAGAIN) 655 goto got_it; 656 } 657 658 /* Next simple case - plain lookup or failed read of indirect block */ 659 if (!create || err == -EIO) 660 goto cleanup; 661 662 mutex_lock(&ei->truncate_mutex); 663 /* 664 * If the indirect block is missing while we are reading 665 * the chain(ext2_get_branch() returns -EAGAIN err), or 666 * if the chain has been changed after we grab the semaphore, 667 * (either because another process truncated this branch, or 668 * another get_block allocated this branch) re-grab the chain to see if 669 * the request block has been allocated or not. 670 * 671 * Since we already block the truncate/other get_block 672 * at this point, we will have the current copy of the chain when we 673 * splice the branch into the tree. 674 */ 675 if (err == -EAGAIN || !verify_chain(chain, partial)) { 676 while (partial > chain) { 677 brelse(partial->bh); 678 partial--; 679 } 680 partial = ext2_get_branch(inode, depth, offsets, chain, &err); 681 if (!partial) { 682 count++; 683 mutex_unlock(&ei->truncate_mutex); 684 if (err) 685 goto cleanup; 686 clear_buffer_new(bh_result); 687 goto got_it; 688 } 689 } 690 691 /* 692 * Okay, we need to do block allocation. Lazily initialize the block 693 * allocation info here if necessary 694 */ 695 if (S_ISREG(inode->i_mode) && (!ei->i_block_alloc_info)) 696 ext2_init_block_alloc_info(inode); 697 698 goal = ext2_find_goal(inode, iblock, partial); 699 700 /* the number of blocks need to allocate for [d,t]indirect blocks */ 701 indirect_blks = (chain + depth) - partial - 1; 702 /* 703 * Next look up the indirect map to count the totoal number of 704 * direct blocks to allocate for this branch. 705 */ 706 count = ext2_blks_to_allocate(partial, indirect_blks, 707 maxblocks, blocks_to_boundary); 708 /* 709 * XXX ???? Block out ext2_truncate while we alter the tree 710 */ 711 err = ext2_alloc_branch(inode, indirect_blks, &count, goal, 712 offsets + (partial - chain), partial); 713 714 if (err) { 715 mutex_unlock(&ei->truncate_mutex); 716 goto cleanup; 717 } 718 719 if (ext2_use_xip(inode->i_sb)) { 720 /* 721 * we need to clear the block 722 */ 723 err = ext2_clear_xip_target (inode, 724 le32_to_cpu(chain[depth-1].key)); 725 if (err) { 726 mutex_unlock(&ei->truncate_mutex); 727 goto cleanup; 728 } 729 } 730 731 ext2_splice_branch(inode, iblock, partial, indirect_blks, count); 732 mutex_unlock(&ei->truncate_mutex); 733 set_buffer_new(bh_result); 734 got_it: 735 map_bh(bh_result, inode->i_sb, le32_to_cpu(chain[depth-1].key)); 736 if (count > blocks_to_boundary) 737 set_buffer_boundary(bh_result); 738 err = count; 739 /* Clean up and exit */ 740 partial = chain + depth - 1; /* the whole chain */ 741 cleanup: 742 while (partial > chain) { 743 brelse(partial->bh); 744 partial--; 745 } 746 return err; 747 } 748 749 int ext2_get_block(struct inode *inode, sector_t iblock, struct buffer_head *bh_result, int create) 750 { 751 unsigned max_blocks = bh_result->b_size >> inode->i_blkbits; 752 int ret = ext2_get_blocks(inode, iblock, max_blocks, 753 bh_result, create); 754 if (ret > 0) { 755 bh_result->b_size = (ret << inode->i_blkbits); 756 ret = 0; 757 } 758 return ret; 759 760 } 761 762 int ext2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, 763 u64 start, u64 len) 764 { 765 return generic_block_fiemap(inode, fieinfo, start, len, 766 ext2_get_block); 767 } 768 769 static int ext2_writepage(struct page *page, struct writeback_control *wbc) 770 { 771 return block_write_full_page(page, ext2_get_block, wbc); 772 } 773 774 static int ext2_readpage(struct file *file, struct page *page) 775 { 776 return mpage_readpage(page, ext2_get_block); 777 } 778 779 static int 780 ext2_readpages(struct file *file, struct address_space *mapping, 781 struct list_head *pages, unsigned nr_pages) 782 { 783 return mpage_readpages(mapping, pages, nr_pages, ext2_get_block); 784 } 785 786 static int 787 ext2_write_begin(struct file *file, struct address_space *mapping, 788 loff_t pos, unsigned len, unsigned flags, 789 struct page **pagep, void **fsdata) 790 { 791 int ret; 792 793 ret = block_write_begin(mapping, pos, len, flags, pagep, 794 ext2_get_block); 795 if (ret < 0) 796 ext2_write_failed(mapping, pos + len); 797 return ret; 798 } 799 800 static int ext2_write_end(struct file *file, struct address_space *mapping, 801 loff_t pos, unsigned len, unsigned copied, 802 struct page *page, void *fsdata) 803 { 804 int ret; 805 806 ret = generic_write_end(file, mapping, pos, len, copied, page, fsdata); 807 if (ret < len) 808 ext2_write_failed(mapping, pos + len); 809 return ret; 810 } 811 812 static int 813 ext2_nobh_write_begin(struct file *file, struct address_space *mapping, 814 loff_t pos, unsigned len, unsigned flags, 815 struct page **pagep, void **fsdata) 816 { 817 int ret; 818 819 ret = nobh_write_begin(mapping, pos, len, flags, pagep, fsdata, 820 ext2_get_block); 821 if (ret < 0) 822 ext2_write_failed(mapping, pos + len); 823 return ret; 824 } 825 826 static int ext2_nobh_writepage(struct page *page, 827 struct writeback_control *wbc) 828 { 829 return nobh_writepage(page, ext2_get_block, wbc); 830 } 831 832 static sector_t ext2_bmap(struct address_space *mapping, sector_t block) 833 { 834 return generic_block_bmap(mapping,block,ext2_get_block); 835 } 836 837 static ssize_t 838 ext2_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov, 839 loff_t offset, unsigned long nr_segs) 840 { 841 struct file *file = iocb->ki_filp; 842 struct address_space *mapping = file->f_mapping; 843 struct inode *inode = mapping->host; 844 ssize_t ret; 845 846 ret = blockdev_direct_IO(rw, iocb, inode, iov, offset, nr_segs, 847 ext2_get_block); 848 if (ret < 0 && (rw & WRITE)) 849 ext2_write_failed(mapping, offset + iov_length(iov, nr_segs)); 850 return ret; 851 } 852 853 static int 854 ext2_writepages(struct address_space *mapping, struct writeback_control *wbc) 855 { 856 return mpage_writepages(mapping, wbc, ext2_get_block); 857 } 858 859 const struct address_space_operations ext2_aops = { 860 .readpage = ext2_readpage, 861 .readpages = ext2_readpages, 862 .writepage = ext2_writepage, 863 .write_begin = ext2_write_begin, 864 .write_end = ext2_write_end, 865 .bmap = ext2_bmap, 866 .direct_IO = ext2_direct_IO, 867 .writepages = ext2_writepages, 868 .migratepage = buffer_migrate_page, 869 .is_partially_uptodate = block_is_partially_uptodate, 870 .error_remove_page = generic_error_remove_page, 871 }; 872 873 const struct address_space_operations ext2_aops_xip = { 874 .bmap = ext2_bmap, 875 .get_xip_mem = ext2_get_xip_mem, 876 }; 877 878 const struct address_space_operations ext2_nobh_aops = { 879 .readpage = ext2_readpage, 880 .readpages = ext2_readpages, 881 .writepage = ext2_nobh_writepage, 882 .write_begin = ext2_nobh_write_begin, 883 .write_end = nobh_write_end, 884 .bmap = ext2_bmap, 885 .direct_IO = ext2_direct_IO, 886 .writepages = ext2_writepages, 887 .migratepage = buffer_migrate_page, 888 .error_remove_page = generic_error_remove_page, 889 }; 890 891 /* 892 * Probably it should be a library function... search for first non-zero word 893 * or memcmp with zero_page, whatever is better for particular architecture. 894 * Linus? 895 */ 896 static inline int all_zeroes(__le32 *p, __le32 *q) 897 { 898 while (p < q) 899 if (*p++) 900 return 0; 901 return 1; 902 } 903 904 /** 905 * ext2_find_shared - find the indirect blocks for partial truncation. 906 * @inode: inode in question 907 * @depth: depth of the affected branch 908 * @offsets: offsets of pointers in that branch (see ext2_block_to_path) 909 * @chain: place to store the pointers to partial indirect blocks 910 * @top: place to the (detached) top of branch 911 * 912 * This is a helper function used by ext2_truncate(). 913 * 914 * When we do truncate() we may have to clean the ends of several indirect 915 * blocks but leave the blocks themselves alive. Block is partially 916 * truncated if some data below the new i_size is referred from it (and 917 * it is on the path to the first completely truncated data block, indeed). 918 * We have to free the top of that path along with everything to the right 919 * of the path. Since no allocation past the truncation point is possible 920 * until ext2_truncate() finishes, we may safely do the latter, but top 921 * of branch may require special attention - pageout below the truncation 922 * point might try to populate it. 923 * 924 * We atomically detach the top of branch from the tree, store the block 925 * number of its root in *@top, pointers to buffer_heads of partially 926 * truncated blocks - in @chain[].bh and pointers to their last elements 927 * that should not be removed - in @chain[].p. Return value is the pointer 928 * to last filled element of @chain. 929 * 930 * The work left to caller to do the actual freeing of subtrees: 931 * a) free the subtree starting from *@top 932 * b) free the subtrees whose roots are stored in 933 * (@chain[i].p+1 .. end of @chain[i].bh->b_data) 934 * c) free the subtrees growing from the inode past the @chain[0].p 935 * (no partially truncated stuff there). 936 */ 937 938 static Indirect *ext2_find_shared(struct inode *inode, 939 int depth, 940 int offsets[4], 941 Indirect chain[4], 942 __le32 *top) 943 { 944 Indirect *partial, *p; 945 int k, err; 946 947 *top = 0; 948 for (k = depth; k > 1 && !offsets[k-1]; k--) 949 ; 950 partial = ext2_get_branch(inode, k, offsets, chain, &err); 951 if (!partial) 952 partial = chain + k-1; 953 /* 954 * If the branch acquired continuation since we've looked at it - 955 * fine, it should all survive and (new) top doesn't belong to us. 956 */ 957 write_lock(&EXT2_I(inode)->i_meta_lock); 958 if (!partial->key && *partial->p) { 959 write_unlock(&EXT2_I(inode)->i_meta_lock); 960 goto no_top; 961 } 962 for (p=partial; p>chain && all_zeroes((__le32*)p->bh->b_data,p->p); p--) 963 ; 964 /* 965 * OK, we've found the last block that must survive. The rest of our 966 * branch should be detached before unlocking. However, if that rest 967 * of branch is all ours and does not grow immediately from the inode 968 * it's easier to cheat and just decrement partial->p. 969 */ 970 if (p == chain + k - 1 && p > chain) { 971 p->p--; 972 } else { 973 *top = *p->p; 974 *p->p = 0; 975 } 976 write_unlock(&EXT2_I(inode)->i_meta_lock); 977 978 while(partial > p) 979 { 980 brelse(partial->bh); 981 partial--; 982 } 983 no_top: 984 return partial; 985 } 986 987 /** 988 * ext2_free_data - free a list of data blocks 989 * @inode: inode we are dealing with 990 * @p: array of block numbers 991 * @q: points immediately past the end of array 992 * 993 * We are freeing all blocks referred from that array (numbers are 994 * stored as little-endian 32-bit) and updating @inode->i_blocks 995 * appropriately. 996 */ 997 static inline void ext2_free_data(struct inode *inode, __le32 *p, __le32 *q) 998 { 999 unsigned long block_to_free = 0, count = 0; 1000 unsigned long nr; 1001 1002 for ( ; p < q ; p++) { 1003 nr = le32_to_cpu(*p); 1004 if (nr) { 1005 *p = 0; 1006 /* accumulate blocks to free if they're contiguous */ 1007 if (count == 0) 1008 goto free_this; 1009 else if (block_to_free == nr - count) 1010 count++; 1011 else { 1012 ext2_free_blocks (inode, block_to_free, count); 1013 mark_inode_dirty(inode); 1014 free_this: 1015 block_to_free = nr; 1016 count = 1; 1017 } 1018 } 1019 } 1020 if (count > 0) { 1021 ext2_free_blocks (inode, block_to_free, count); 1022 mark_inode_dirty(inode); 1023 } 1024 } 1025 1026 /** 1027 * ext2_free_branches - free an array of branches 1028 * @inode: inode we are dealing with 1029 * @p: array of block numbers 1030 * @q: pointer immediately past the end of array 1031 * @depth: depth of the branches to free 1032 * 1033 * We are freeing all blocks referred from these branches (numbers are 1034 * stored as little-endian 32-bit) and updating @inode->i_blocks 1035 * appropriately. 1036 */ 1037 static void ext2_free_branches(struct inode *inode, __le32 *p, __le32 *q, int depth) 1038 { 1039 struct buffer_head * bh; 1040 unsigned long nr; 1041 1042 if (depth--) { 1043 int addr_per_block = EXT2_ADDR_PER_BLOCK(inode->i_sb); 1044 for ( ; p < q ; p++) { 1045 nr = le32_to_cpu(*p); 1046 if (!nr) 1047 continue; 1048 *p = 0; 1049 bh = sb_bread(inode->i_sb, nr); 1050 /* 1051 * A read failure? Report error and clear slot 1052 * (should be rare). 1053 */ 1054 if (!bh) { 1055 ext2_error(inode->i_sb, "ext2_free_branches", 1056 "Read failure, inode=%ld, block=%ld", 1057 inode->i_ino, nr); 1058 continue; 1059 } 1060 ext2_free_branches(inode, 1061 (__le32*)bh->b_data, 1062 (__le32*)bh->b_data + addr_per_block, 1063 depth); 1064 bforget(bh); 1065 ext2_free_blocks(inode, nr, 1); 1066 mark_inode_dirty(inode); 1067 } 1068 } else 1069 ext2_free_data(inode, p, q); 1070 } 1071 1072 static void __ext2_truncate_blocks(struct inode *inode, loff_t offset) 1073 { 1074 __le32 *i_data = EXT2_I(inode)->i_data; 1075 struct ext2_inode_info *ei = EXT2_I(inode); 1076 int addr_per_block = EXT2_ADDR_PER_BLOCK(inode->i_sb); 1077 int offsets[4]; 1078 Indirect chain[4]; 1079 Indirect *partial; 1080 __le32 nr = 0; 1081 int n; 1082 long iblock; 1083 unsigned blocksize; 1084 blocksize = inode->i_sb->s_blocksize; 1085 iblock = (offset + blocksize-1) >> EXT2_BLOCK_SIZE_BITS(inode->i_sb); 1086 1087 n = ext2_block_to_path(inode, iblock, offsets, NULL); 1088 if (n == 0) 1089 return; 1090 1091 /* 1092 * From here we block out all ext2_get_block() callers who want to 1093 * modify the block allocation tree. 1094 */ 1095 mutex_lock(&ei->truncate_mutex); 1096 1097 if (n == 1) { 1098 ext2_free_data(inode, i_data+offsets[0], 1099 i_data + EXT2_NDIR_BLOCKS); 1100 goto do_indirects; 1101 } 1102 1103 partial = ext2_find_shared(inode, n, offsets, chain, &nr); 1104 /* Kill the top of shared branch (already detached) */ 1105 if (nr) { 1106 if (partial == chain) 1107 mark_inode_dirty(inode); 1108 else 1109 mark_buffer_dirty_inode(partial->bh, inode); 1110 ext2_free_branches(inode, &nr, &nr+1, (chain+n-1) - partial); 1111 } 1112 /* Clear the ends of indirect blocks on the shared branch */ 1113 while (partial > chain) { 1114 ext2_free_branches(inode, 1115 partial->p + 1, 1116 (__le32*)partial->bh->b_data+addr_per_block, 1117 (chain+n-1) - partial); 1118 mark_buffer_dirty_inode(partial->bh, inode); 1119 brelse (partial->bh); 1120 partial--; 1121 } 1122 do_indirects: 1123 /* Kill the remaining (whole) subtrees */ 1124 switch (offsets[0]) { 1125 default: 1126 nr = i_data[EXT2_IND_BLOCK]; 1127 if (nr) { 1128 i_data[EXT2_IND_BLOCK] = 0; 1129 mark_inode_dirty(inode); 1130 ext2_free_branches(inode, &nr, &nr+1, 1); 1131 } 1132 case EXT2_IND_BLOCK: 1133 nr = i_data[EXT2_DIND_BLOCK]; 1134 if (nr) { 1135 i_data[EXT2_DIND_BLOCK] = 0; 1136 mark_inode_dirty(inode); 1137 ext2_free_branches(inode, &nr, &nr+1, 2); 1138 } 1139 case EXT2_DIND_BLOCK: 1140 nr = i_data[EXT2_TIND_BLOCK]; 1141 if (nr) { 1142 i_data[EXT2_TIND_BLOCK] = 0; 1143 mark_inode_dirty(inode); 1144 ext2_free_branches(inode, &nr, &nr+1, 3); 1145 } 1146 case EXT2_TIND_BLOCK: 1147 ; 1148 } 1149 1150 ext2_discard_reservation(inode); 1151 1152 mutex_unlock(&ei->truncate_mutex); 1153 } 1154 1155 static void ext2_truncate_blocks(struct inode *inode, loff_t offset) 1156 { 1157 /* 1158 * XXX: it seems like a bug here that we don't allow 1159 * IS_APPEND inode to have blocks-past-i_size trimmed off. 1160 * review and fix this. 1161 * 1162 * Also would be nice to be able to handle IO errors and such, 1163 * but that's probably too much to ask. 1164 */ 1165 if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || 1166 S_ISLNK(inode->i_mode))) 1167 return; 1168 if (ext2_inode_is_fast_symlink(inode)) 1169 return; 1170 if (IS_APPEND(inode) || IS_IMMUTABLE(inode)) 1171 return; 1172 __ext2_truncate_blocks(inode, offset); 1173 } 1174 1175 static int ext2_setsize(struct inode *inode, loff_t newsize) 1176 { 1177 int error; 1178 1179 if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || 1180 S_ISLNK(inode->i_mode))) 1181 return -EINVAL; 1182 if (ext2_inode_is_fast_symlink(inode)) 1183 return -EINVAL; 1184 if (IS_APPEND(inode) || IS_IMMUTABLE(inode)) 1185 return -EPERM; 1186 1187 inode_dio_wait(inode); 1188 1189 if (mapping_is_xip(inode->i_mapping)) 1190 error = xip_truncate_page(inode->i_mapping, newsize); 1191 else if (test_opt(inode->i_sb, NOBH)) 1192 error = nobh_truncate_page(inode->i_mapping, 1193 newsize, ext2_get_block); 1194 else 1195 error = block_truncate_page(inode->i_mapping, 1196 newsize, ext2_get_block); 1197 if (error) 1198 return error; 1199 1200 truncate_setsize(inode, newsize); 1201 __ext2_truncate_blocks(inode, newsize); 1202 1203 inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC; 1204 if (inode_needs_sync(inode)) { 1205 sync_mapping_buffers(inode->i_mapping); 1206 sync_inode_metadata(inode, 1); 1207 } else { 1208 mark_inode_dirty(inode); 1209 } 1210 1211 return 0; 1212 } 1213 1214 static struct ext2_inode *ext2_get_inode(struct super_block *sb, ino_t ino, 1215 struct buffer_head **p) 1216 { 1217 struct buffer_head * bh; 1218 unsigned long block_group; 1219 unsigned long block; 1220 unsigned long offset; 1221 struct ext2_group_desc * gdp; 1222 1223 *p = NULL; 1224 if ((ino != EXT2_ROOT_INO && ino < EXT2_FIRST_INO(sb)) || 1225 ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count)) 1226 goto Einval; 1227 1228 block_group = (ino - 1) / EXT2_INODES_PER_GROUP(sb); 1229 gdp = ext2_get_group_desc(sb, block_group, NULL); 1230 if (!gdp) 1231 goto Egdp; 1232 /* 1233 * Figure out the offset within the block group inode table 1234 */ 1235 offset = ((ino - 1) % EXT2_INODES_PER_GROUP(sb)) * EXT2_INODE_SIZE(sb); 1236 block = le32_to_cpu(gdp->bg_inode_table) + 1237 (offset >> EXT2_BLOCK_SIZE_BITS(sb)); 1238 if (!(bh = sb_bread(sb, block))) 1239 goto Eio; 1240 1241 *p = bh; 1242 offset &= (EXT2_BLOCK_SIZE(sb) - 1); 1243 return (struct ext2_inode *) (bh->b_data + offset); 1244 1245 Einval: 1246 ext2_error(sb, "ext2_get_inode", "bad inode number: %lu", 1247 (unsigned long) ino); 1248 return ERR_PTR(-EINVAL); 1249 Eio: 1250 ext2_error(sb, "ext2_get_inode", 1251 "unable to read inode block - inode=%lu, block=%lu", 1252 (unsigned long) ino, block); 1253 Egdp: 1254 return ERR_PTR(-EIO); 1255 } 1256 1257 void ext2_set_inode_flags(struct inode *inode) 1258 { 1259 unsigned int flags = EXT2_I(inode)->i_flags; 1260 1261 inode->i_flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC); 1262 if (flags & EXT2_SYNC_FL) 1263 inode->i_flags |= S_SYNC; 1264 if (flags & EXT2_APPEND_FL) 1265 inode->i_flags |= S_APPEND; 1266 if (flags & EXT2_IMMUTABLE_FL) 1267 inode->i_flags |= S_IMMUTABLE; 1268 if (flags & EXT2_NOATIME_FL) 1269 inode->i_flags |= S_NOATIME; 1270 if (flags & EXT2_DIRSYNC_FL) 1271 inode->i_flags |= S_DIRSYNC; 1272 } 1273 1274 /* Propagate flags from i_flags to EXT2_I(inode)->i_flags */ 1275 void ext2_get_inode_flags(struct ext2_inode_info *ei) 1276 { 1277 unsigned int flags = ei->vfs_inode.i_flags; 1278 1279 ei->i_flags &= ~(EXT2_SYNC_FL|EXT2_APPEND_FL| 1280 EXT2_IMMUTABLE_FL|EXT2_NOATIME_FL|EXT2_DIRSYNC_FL); 1281 if (flags & S_SYNC) 1282 ei->i_flags |= EXT2_SYNC_FL; 1283 if (flags & S_APPEND) 1284 ei->i_flags |= EXT2_APPEND_FL; 1285 if (flags & S_IMMUTABLE) 1286 ei->i_flags |= EXT2_IMMUTABLE_FL; 1287 if (flags & S_NOATIME) 1288 ei->i_flags |= EXT2_NOATIME_FL; 1289 if (flags & S_DIRSYNC) 1290 ei->i_flags |= EXT2_DIRSYNC_FL; 1291 } 1292 1293 struct inode *ext2_iget (struct super_block *sb, unsigned long ino) 1294 { 1295 struct ext2_inode_info *ei; 1296 struct buffer_head * bh; 1297 struct ext2_inode *raw_inode; 1298 struct inode *inode; 1299 long ret = -EIO; 1300 int n; 1301 1302 inode = iget_locked(sb, ino); 1303 if (!inode) 1304 return ERR_PTR(-ENOMEM); 1305 if (!(inode->i_state & I_NEW)) 1306 return inode; 1307 1308 ei = EXT2_I(inode); 1309 ei->i_block_alloc_info = NULL; 1310 1311 raw_inode = ext2_get_inode(inode->i_sb, ino, &bh); 1312 if (IS_ERR(raw_inode)) { 1313 ret = PTR_ERR(raw_inode); 1314 goto bad_inode; 1315 } 1316 1317 inode->i_mode = le16_to_cpu(raw_inode->i_mode); 1318 inode->i_uid = (uid_t)le16_to_cpu(raw_inode->i_uid_low); 1319 inode->i_gid = (gid_t)le16_to_cpu(raw_inode->i_gid_low); 1320 if (!(test_opt (inode->i_sb, NO_UID32))) { 1321 inode->i_uid |= le16_to_cpu(raw_inode->i_uid_high) << 16; 1322 inode->i_gid |= le16_to_cpu(raw_inode->i_gid_high) << 16; 1323 } 1324 inode->i_nlink = le16_to_cpu(raw_inode->i_links_count); 1325 inode->i_size = le32_to_cpu(raw_inode->i_size); 1326 inode->i_atime.tv_sec = (signed)le32_to_cpu(raw_inode->i_atime); 1327 inode->i_ctime.tv_sec = (signed)le32_to_cpu(raw_inode->i_ctime); 1328 inode->i_mtime.tv_sec = (signed)le32_to_cpu(raw_inode->i_mtime); 1329 inode->i_atime.tv_nsec = inode->i_mtime.tv_nsec = inode->i_ctime.tv_nsec = 0; 1330 ei->i_dtime = le32_to_cpu(raw_inode->i_dtime); 1331 /* We now have enough fields to check if the inode was active or not. 1332 * This is needed because nfsd might try to access dead inodes 1333 * the test is that same one that e2fsck uses 1334 * NeilBrown 1999oct15 1335 */ 1336 if (inode->i_nlink == 0 && (inode->i_mode == 0 || ei->i_dtime)) { 1337 /* this inode is deleted */ 1338 brelse (bh); 1339 ret = -ESTALE; 1340 goto bad_inode; 1341 } 1342 inode->i_blocks = le32_to_cpu(raw_inode->i_blocks); 1343 ei->i_flags = le32_to_cpu(raw_inode->i_flags); 1344 ei->i_faddr = le32_to_cpu(raw_inode->i_faddr); 1345 ei->i_frag_no = raw_inode->i_frag; 1346 ei->i_frag_size = raw_inode->i_fsize; 1347 ei->i_file_acl = le32_to_cpu(raw_inode->i_file_acl); 1348 ei->i_dir_acl = 0; 1349 if (S_ISREG(inode->i_mode)) 1350 inode->i_size |= ((__u64)le32_to_cpu(raw_inode->i_size_high)) << 32; 1351 else 1352 ei->i_dir_acl = le32_to_cpu(raw_inode->i_dir_acl); 1353 ei->i_dtime = 0; 1354 inode->i_generation = le32_to_cpu(raw_inode->i_generation); 1355 ei->i_state = 0; 1356 ei->i_block_group = (ino - 1) / EXT2_INODES_PER_GROUP(inode->i_sb); 1357 ei->i_dir_start_lookup = 0; 1358 1359 /* 1360 * NOTE! The in-memory inode i_data array is in little-endian order 1361 * even on big-endian machines: we do NOT byteswap the block numbers! 1362 */ 1363 for (n = 0; n < EXT2_N_BLOCKS; n++) 1364 ei->i_data[n] = raw_inode->i_block[n]; 1365 1366 if (S_ISREG(inode->i_mode)) { 1367 inode->i_op = &ext2_file_inode_operations; 1368 if (ext2_use_xip(inode->i_sb)) { 1369 inode->i_mapping->a_ops = &ext2_aops_xip; 1370 inode->i_fop = &ext2_xip_file_operations; 1371 } else if (test_opt(inode->i_sb, NOBH)) { 1372 inode->i_mapping->a_ops = &ext2_nobh_aops; 1373 inode->i_fop = &ext2_file_operations; 1374 } else { 1375 inode->i_mapping->a_ops = &ext2_aops; 1376 inode->i_fop = &ext2_file_operations; 1377 } 1378 } else if (S_ISDIR(inode->i_mode)) { 1379 inode->i_op = &ext2_dir_inode_operations; 1380 inode->i_fop = &ext2_dir_operations; 1381 if (test_opt(inode->i_sb, NOBH)) 1382 inode->i_mapping->a_ops = &ext2_nobh_aops; 1383 else 1384 inode->i_mapping->a_ops = &ext2_aops; 1385 } else if (S_ISLNK(inode->i_mode)) { 1386 if (ext2_inode_is_fast_symlink(inode)) { 1387 inode->i_op = &ext2_fast_symlink_inode_operations; 1388 nd_terminate_link(ei->i_data, inode->i_size, 1389 sizeof(ei->i_data) - 1); 1390 } else { 1391 inode->i_op = &ext2_symlink_inode_operations; 1392 if (test_opt(inode->i_sb, NOBH)) 1393 inode->i_mapping->a_ops = &ext2_nobh_aops; 1394 else 1395 inode->i_mapping->a_ops = &ext2_aops; 1396 } 1397 } else { 1398 inode->i_op = &ext2_special_inode_operations; 1399 if (raw_inode->i_block[0]) 1400 init_special_inode(inode, inode->i_mode, 1401 old_decode_dev(le32_to_cpu(raw_inode->i_block[0]))); 1402 else 1403 init_special_inode(inode, inode->i_mode, 1404 new_decode_dev(le32_to_cpu(raw_inode->i_block[1]))); 1405 } 1406 brelse (bh); 1407 ext2_set_inode_flags(inode); 1408 unlock_new_inode(inode); 1409 return inode; 1410 1411 bad_inode: 1412 iget_failed(inode); 1413 return ERR_PTR(ret); 1414 } 1415 1416 static int __ext2_write_inode(struct inode *inode, int do_sync) 1417 { 1418 struct ext2_inode_info *ei = EXT2_I(inode); 1419 struct super_block *sb = inode->i_sb; 1420 ino_t ino = inode->i_ino; 1421 uid_t uid = inode->i_uid; 1422 gid_t gid = inode->i_gid; 1423 struct buffer_head * bh; 1424 struct ext2_inode * raw_inode = ext2_get_inode(sb, ino, &bh); 1425 int n; 1426 int err = 0; 1427 1428 if (IS_ERR(raw_inode)) 1429 return -EIO; 1430 1431 /* For fields not not tracking in the in-memory inode, 1432 * initialise them to zero for new inodes. */ 1433 if (ei->i_state & EXT2_STATE_NEW) 1434 memset(raw_inode, 0, EXT2_SB(sb)->s_inode_size); 1435 1436 ext2_get_inode_flags(ei); 1437 raw_inode->i_mode = cpu_to_le16(inode->i_mode); 1438 if (!(test_opt(sb, NO_UID32))) { 1439 raw_inode->i_uid_low = cpu_to_le16(low_16_bits(uid)); 1440 raw_inode->i_gid_low = cpu_to_le16(low_16_bits(gid)); 1441 /* 1442 * Fix up interoperability with old kernels. Otherwise, old inodes get 1443 * re-used with the upper 16 bits of the uid/gid intact 1444 */ 1445 if (!ei->i_dtime) { 1446 raw_inode->i_uid_high = cpu_to_le16(high_16_bits(uid)); 1447 raw_inode->i_gid_high = cpu_to_le16(high_16_bits(gid)); 1448 } else { 1449 raw_inode->i_uid_high = 0; 1450 raw_inode->i_gid_high = 0; 1451 } 1452 } else { 1453 raw_inode->i_uid_low = cpu_to_le16(fs_high2lowuid(uid)); 1454 raw_inode->i_gid_low = cpu_to_le16(fs_high2lowgid(gid)); 1455 raw_inode->i_uid_high = 0; 1456 raw_inode->i_gid_high = 0; 1457 } 1458 raw_inode->i_links_count = cpu_to_le16(inode->i_nlink); 1459 raw_inode->i_size = cpu_to_le32(inode->i_size); 1460 raw_inode->i_atime = cpu_to_le32(inode->i_atime.tv_sec); 1461 raw_inode->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec); 1462 raw_inode->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec); 1463 1464 raw_inode->i_blocks = cpu_to_le32(inode->i_blocks); 1465 raw_inode->i_dtime = cpu_to_le32(ei->i_dtime); 1466 raw_inode->i_flags = cpu_to_le32(ei->i_flags); 1467 raw_inode->i_faddr = cpu_to_le32(ei->i_faddr); 1468 raw_inode->i_frag = ei->i_frag_no; 1469 raw_inode->i_fsize = ei->i_frag_size; 1470 raw_inode->i_file_acl = cpu_to_le32(ei->i_file_acl); 1471 if (!S_ISREG(inode->i_mode)) 1472 raw_inode->i_dir_acl = cpu_to_le32(ei->i_dir_acl); 1473 else { 1474 raw_inode->i_size_high = cpu_to_le32(inode->i_size >> 32); 1475 if (inode->i_size > 0x7fffffffULL) { 1476 if (!EXT2_HAS_RO_COMPAT_FEATURE(sb, 1477 EXT2_FEATURE_RO_COMPAT_LARGE_FILE) || 1478 EXT2_SB(sb)->s_es->s_rev_level == 1479 cpu_to_le32(EXT2_GOOD_OLD_REV)) { 1480 /* If this is the first large file 1481 * created, add a flag to the superblock. 1482 */ 1483 spin_lock(&EXT2_SB(sb)->s_lock); 1484 ext2_update_dynamic_rev(sb); 1485 EXT2_SET_RO_COMPAT_FEATURE(sb, 1486 EXT2_FEATURE_RO_COMPAT_LARGE_FILE); 1487 spin_unlock(&EXT2_SB(sb)->s_lock); 1488 ext2_write_super(sb); 1489 } 1490 } 1491 } 1492 1493 raw_inode->i_generation = cpu_to_le32(inode->i_generation); 1494 if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) { 1495 if (old_valid_dev(inode->i_rdev)) { 1496 raw_inode->i_block[0] = 1497 cpu_to_le32(old_encode_dev(inode->i_rdev)); 1498 raw_inode->i_block[1] = 0; 1499 } else { 1500 raw_inode->i_block[0] = 0; 1501 raw_inode->i_block[1] = 1502 cpu_to_le32(new_encode_dev(inode->i_rdev)); 1503 raw_inode->i_block[2] = 0; 1504 } 1505 } else for (n = 0; n < EXT2_N_BLOCKS; n++) 1506 raw_inode->i_block[n] = ei->i_data[n]; 1507 mark_buffer_dirty(bh); 1508 if (do_sync) { 1509 sync_dirty_buffer(bh); 1510 if (buffer_req(bh) && !buffer_uptodate(bh)) { 1511 printk ("IO error syncing ext2 inode [%s:%08lx]\n", 1512 sb->s_id, (unsigned long) ino); 1513 err = -EIO; 1514 } 1515 } 1516 ei->i_state &= ~EXT2_STATE_NEW; 1517 brelse (bh); 1518 return err; 1519 } 1520 1521 int ext2_write_inode(struct inode *inode, struct writeback_control *wbc) 1522 { 1523 return __ext2_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL); 1524 } 1525 1526 int ext2_setattr(struct dentry *dentry, struct iattr *iattr) 1527 { 1528 struct inode *inode = dentry->d_inode; 1529 int error; 1530 1531 error = inode_change_ok(inode, iattr); 1532 if (error) 1533 return error; 1534 1535 if (is_quota_modification(inode, iattr)) 1536 dquot_initialize(inode); 1537 if ((iattr->ia_valid & ATTR_UID && iattr->ia_uid != inode->i_uid) || 1538 (iattr->ia_valid & ATTR_GID && iattr->ia_gid != inode->i_gid)) { 1539 error = dquot_transfer(inode, iattr); 1540 if (error) 1541 return error; 1542 } 1543 if (iattr->ia_valid & ATTR_SIZE && iattr->ia_size != inode->i_size) { 1544 error = ext2_setsize(inode, iattr->ia_size); 1545 if (error) 1546 return error; 1547 } 1548 setattr_copy(inode, iattr); 1549 if (iattr->ia_valid & ATTR_MODE) 1550 error = ext2_acl_chmod(inode); 1551 mark_inode_dirty(inode); 1552 1553 return error; 1554 } 1555