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/dax.h> 29 #include <linux/blkdev.h> 30 #include <linux/quotaops.h> 31 #include <linux/writeback.h> 32 #include <linux/buffer_head.h> 33 #include <linux/mpage.h> 34 #include <linux/fiemap.h> 35 #include <linux/namei.h> 36 #include <linux/uio.h> 37 #include "ext2.h" 38 #include "acl.h" 39 #include "xattr.h" 40 41 static int __ext2_write_inode(struct inode *inode, int do_sync); 42 43 /* 44 * Test whether an inode is a fast symlink. 45 */ 46 static inline int ext2_inode_is_fast_symlink(struct inode *inode) 47 { 48 int ea_blocks = EXT2_I(inode)->i_file_acl ? 49 (inode->i_sb->s_blocksize >> 9) : 0; 50 51 return (S_ISLNK(inode->i_mode) && 52 inode->i_blocks - ea_blocks == 0); 53 } 54 55 static void ext2_truncate_blocks(struct inode *inode, loff_t offset); 56 57 static void ext2_write_failed(struct address_space *mapping, loff_t to) 58 { 59 struct inode *inode = mapping->host; 60 61 if (to > inode->i_size) { 62 truncate_pagecache(inode, inode->i_size); 63 ext2_truncate_blocks(inode, inode->i_size); 64 } 65 } 66 67 /* 68 * Called at the last iput() if i_nlink is zero. 69 */ 70 void ext2_evict_inode(struct inode * inode) 71 { 72 struct ext2_block_alloc_info *rsv; 73 int want_delete = 0; 74 75 if (!inode->i_nlink && !is_bad_inode(inode)) { 76 want_delete = 1; 77 dquot_initialize(inode); 78 } else { 79 dquot_drop(inode); 80 } 81 82 truncate_inode_pages_final(&inode->i_data); 83 84 if (want_delete) { 85 sb_start_intwrite(inode->i_sb); 86 /* set dtime */ 87 EXT2_I(inode)->i_dtime = get_seconds(); 88 mark_inode_dirty(inode); 89 __ext2_write_inode(inode, inode_needs_sync(inode)); 90 /* truncate to 0 */ 91 inode->i_size = 0; 92 if (inode->i_blocks) 93 ext2_truncate_blocks(inode, 0); 94 ext2_xattr_delete_inode(inode); 95 } 96 97 invalidate_inode_buffers(inode); 98 clear_inode(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 sb_end_intwrite(inode->i_sb); 109 } 110 } 111 112 typedef struct { 113 __le32 *p; 114 __le32 key; 115 struct buffer_head *bh; 116 } Indirect; 117 118 static inline void add_chain(Indirect *p, struct buffer_head *bh, __le32 *v) 119 { 120 p->key = *(p->p = v); 121 p->bh = bh; 122 } 123 124 static inline int verify_chain(Indirect *from, Indirect *to) 125 { 126 while (from <= to && from->key == *from->p) 127 from++; 128 return (from > to); 129 } 130 131 /** 132 * ext2_block_to_path - parse the block number into array of offsets 133 * @inode: inode in question (we are only interested in its superblock) 134 * @i_block: block number to be parsed 135 * @offsets: array to store the offsets in 136 * @boundary: set this non-zero if the referred-to block is likely to be 137 * followed (on disk) by an indirect block. 138 * To store the locations of file's data ext2 uses a data structure common 139 * for UNIX filesystems - tree of pointers anchored in the inode, with 140 * data blocks at leaves and indirect blocks in intermediate nodes. 141 * This function translates the block number into path in that tree - 142 * return value is the path length and @offsets[n] is the offset of 143 * pointer to (n+1)th node in the nth one. If @block is out of range 144 * (negative or too large) warning is printed and zero returned. 145 * 146 * Note: function doesn't find node addresses, so no IO is needed. All 147 * we need to know is the capacity of indirect blocks (taken from the 148 * inode->i_sb). 149 */ 150 151 /* 152 * Portability note: the last comparison (check that we fit into triple 153 * indirect block) is spelled differently, because otherwise on an 154 * architecture with 32-bit longs and 8Kb pages we might get into trouble 155 * if our filesystem had 8Kb blocks. We might use long long, but that would 156 * kill us on x86. Oh, well, at least the sign propagation does not matter - 157 * i_block would have to be negative in the very beginning, so we would not 158 * get there at all. 159 */ 160 161 static int ext2_block_to_path(struct inode *inode, 162 long i_block, int offsets[4], int *boundary) 163 { 164 int ptrs = EXT2_ADDR_PER_BLOCK(inode->i_sb); 165 int ptrs_bits = EXT2_ADDR_PER_BLOCK_BITS(inode->i_sb); 166 const long direct_blocks = EXT2_NDIR_BLOCKS, 167 indirect_blocks = ptrs, 168 double_blocks = (1 << (ptrs_bits * 2)); 169 int n = 0; 170 int final = 0; 171 172 if (i_block < 0) { 173 ext2_msg(inode->i_sb, KERN_WARNING, 174 "warning: %s: block < 0", __func__); 175 } else if (i_block < direct_blocks) { 176 offsets[n++] = i_block; 177 final = direct_blocks; 178 } else if ( (i_block -= direct_blocks) < indirect_blocks) { 179 offsets[n++] = EXT2_IND_BLOCK; 180 offsets[n++] = i_block; 181 final = ptrs; 182 } else if ((i_block -= indirect_blocks) < double_blocks) { 183 offsets[n++] = EXT2_DIND_BLOCK; 184 offsets[n++] = i_block >> ptrs_bits; 185 offsets[n++] = i_block & (ptrs - 1); 186 final = ptrs; 187 } else if (((i_block -= double_blocks) >> (ptrs_bits * 2)) < ptrs) { 188 offsets[n++] = EXT2_TIND_BLOCK; 189 offsets[n++] = i_block >> (ptrs_bits * 2); 190 offsets[n++] = (i_block >> ptrs_bits) & (ptrs - 1); 191 offsets[n++] = i_block & (ptrs - 1); 192 final = ptrs; 193 } else { 194 ext2_msg(inode->i_sb, KERN_WARNING, 195 "warning: %s: block is too big", __func__); 196 } 197 if (boundary) 198 *boundary = final - 1 - (i_block & (ptrs - 1)); 199 200 return n; 201 } 202 203 /** 204 * ext2_get_branch - read the chain of indirect blocks leading to data 205 * @inode: inode in question 206 * @depth: depth of the chain (1 - direct pointer, etc.) 207 * @offsets: offsets of pointers in inode/indirect blocks 208 * @chain: place to store the result 209 * @err: here we store the error value 210 * 211 * Function fills the array of triples <key, p, bh> and returns %NULL 212 * if everything went OK or the pointer to the last filled triple 213 * (incomplete one) otherwise. Upon the return chain[i].key contains 214 * the number of (i+1)-th block in the chain (as it is stored in memory, 215 * i.e. little-endian 32-bit), chain[i].p contains the address of that 216 * number (it points into struct inode for i==0 and into the bh->b_data 217 * for i>0) and chain[i].bh points to the buffer_head of i-th indirect 218 * block for i>0 and NULL for i==0. In other words, it holds the block 219 * numbers of the chain, addresses they were taken from (and where we can 220 * verify that chain did not change) and buffer_heads hosting these 221 * numbers. 222 * 223 * Function stops when it stumbles upon zero pointer (absent block) 224 * (pointer to last triple returned, *@err == 0) 225 * or when it gets an IO error reading an indirect block 226 * (ditto, *@err == -EIO) 227 * or when it notices that chain had been changed while it was reading 228 * (ditto, *@err == -EAGAIN) 229 * or when it reads all @depth-1 indirect blocks successfully and finds 230 * the whole chain, all way to the data (returns %NULL, *err == 0). 231 */ 232 static Indirect *ext2_get_branch(struct inode *inode, 233 int depth, 234 int *offsets, 235 Indirect chain[4], 236 int *err) 237 { 238 struct super_block *sb = inode->i_sb; 239 Indirect *p = chain; 240 struct buffer_head *bh; 241 242 *err = 0; 243 /* i_data is not going away, no lock needed */ 244 add_chain (chain, NULL, EXT2_I(inode)->i_data + *offsets); 245 if (!p->key) 246 goto no_block; 247 while (--depth) { 248 bh = sb_bread(sb, le32_to_cpu(p->key)); 249 if (!bh) 250 goto failure; 251 read_lock(&EXT2_I(inode)->i_meta_lock); 252 if (!verify_chain(chain, p)) 253 goto changed; 254 add_chain(++p, bh, (__le32*)bh->b_data + *++offsets); 255 read_unlock(&EXT2_I(inode)->i_meta_lock); 256 if (!p->key) 257 goto no_block; 258 } 259 return NULL; 260 261 changed: 262 read_unlock(&EXT2_I(inode)->i_meta_lock); 263 brelse(bh); 264 *err = -EAGAIN; 265 goto no_block; 266 failure: 267 *err = -EIO; 268 no_block: 269 return p; 270 } 271 272 /** 273 * ext2_find_near - find a place for allocation with sufficient locality 274 * @inode: owner 275 * @ind: descriptor of indirect block. 276 * 277 * This function returns the preferred place for block allocation. 278 * It is used when heuristic for sequential allocation fails. 279 * Rules are: 280 * + if there is a block to the left of our position - allocate near it. 281 * + if pointer will live in indirect block - allocate near that block. 282 * + if pointer will live in inode - allocate in the same cylinder group. 283 * 284 * In the latter case we colour the starting block by the callers PID to 285 * prevent it from clashing with concurrent allocations for a different inode 286 * in the same block group. The PID is used here so that functionally related 287 * files will be close-by on-disk. 288 * 289 * Caller must make sure that @ind is valid and will stay that way. 290 */ 291 292 static ext2_fsblk_t ext2_find_near(struct inode *inode, Indirect *ind) 293 { 294 struct ext2_inode_info *ei = EXT2_I(inode); 295 __le32 *start = ind->bh ? (__le32 *) ind->bh->b_data : ei->i_data; 296 __le32 *p; 297 ext2_fsblk_t bg_start; 298 ext2_fsblk_t colour; 299 300 /* Try to find previous block */ 301 for (p = ind->p - 1; p >= start; p--) 302 if (*p) 303 return le32_to_cpu(*p); 304 305 /* No such thing, so let's try location of indirect block */ 306 if (ind->bh) 307 return ind->bh->b_blocknr; 308 309 /* 310 * It is going to be referred from inode itself? OK, just put it into 311 * the same cylinder group then. 312 */ 313 bg_start = ext2_group_first_block_no(inode->i_sb, ei->i_block_group); 314 colour = (current->pid % 16) * 315 (EXT2_BLOCKS_PER_GROUP(inode->i_sb) / 16); 316 return bg_start + colour; 317 } 318 319 /** 320 * ext2_find_goal - find a preferred place for allocation. 321 * @inode: owner 322 * @block: block we want 323 * @partial: pointer to the last triple within a chain 324 * 325 * Returns preferred place for a block (the goal). 326 */ 327 328 static inline ext2_fsblk_t ext2_find_goal(struct inode *inode, long block, 329 Indirect *partial) 330 { 331 struct ext2_block_alloc_info *block_i; 332 333 block_i = EXT2_I(inode)->i_block_alloc_info; 334 335 /* 336 * try the heuristic for sequential allocation, 337 * failing that at least try to get decent locality. 338 */ 339 if (block_i && (block == block_i->last_alloc_logical_block + 1) 340 && (block_i->last_alloc_physical_block != 0)) { 341 return block_i->last_alloc_physical_block + 1; 342 } 343 344 return ext2_find_near(inode, partial); 345 } 346 347 /** 348 * ext2_blks_to_allocate: Look up the block map and count the number 349 * of direct blocks need to be allocated for the given branch. 350 * 351 * @branch: chain of indirect blocks 352 * @k: number of blocks need for indirect blocks 353 * @blks: number of data blocks to be mapped. 354 * @blocks_to_boundary: the offset in the indirect block 355 * 356 * return the total number of blocks to be allocate, including the 357 * direct and indirect blocks. 358 */ 359 static int 360 ext2_blks_to_allocate(Indirect * branch, int k, unsigned long blks, 361 int blocks_to_boundary) 362 { 363 unsigned long count = 0; 364 365 /* 366 * Simple case, [t,d]Indirect block(s) has not allocated yet 367 * then it's clear blocks on that path have not allocated 368 */ 369 if (k > 0) { 370 /* right now don't hanel cross boundary allocation */ 371 if (blks < blocks_to_boundary + 1) 372 count += blks; 373 else 374 count += blocks_to_boundary + 1; 375 return count; 376 } 377 378 count++; 379 while (count < blks && count <= blocks_to_boundary 380 && le32_to_cpu(*(branch[0].p + count)) == 0) { 381 count++; 382 } 383 return count; 384 } 385 386 /** 387 * ext2_alloc_blocks: multiple allocate blocks needed for a branch 388 * @indirect_blks: the number of blocks need to allocate for indirect 389 * blocks 390 * 391 * @new_blocks: on return it will store the new block numbers for 392 * the indirect blocks(if needed) and the first direct block, 393 * @blks: on return it will store the total number of allocated 394 * direct blocks 395 */ 396 static int ext2_alloc_blocks(struct inode *inode, 397 ext2_fsblk_t goal, int indirect_blks, int blks, 398 ext2_fsblk_t new_blocks[4], int *err) 399 { 400 int target, i; 401 unsigned long count = 0; 402 int index = 0; 403 ext2_fsblk_t current_block = 0; 404 int ret = 0; 405 406 /* 407 * Here we try to allocate the requested multiple blocks at once, 408 * on a best-effort basis. 409 * To build a branch, we should allocate blocks for 410 * the indirect blocks(if not allocated yet), and at least 411 * the first direct block of this branch. That's the 412 * minimum number of blocks need to allocate(required) 413 */ 414 target = blks + indirect_blks; 415 416 while (1) { 417 count = target; 418 /* allocating blocks for indirect blocks and direct blocks */ 419 current_block = ext2_new_blocks(inode,goal,&count,err); 420 if (*err) 421 goto failed_out; 422 423 target -= count; 424 /* allocate blocks for indirect blocks */ 425 while (index < indirect_blks && count) { 426 new_blocks[index++] = current_block++; 427 count--; 428 } 429 430 if (count > 0) 431 break; 432 } 433 434 /* save the new block number for the first direct block */ 435 new_blocks[index] = current_block; 436 437 /* total number of blocks allocated for direct blocks */ 438 ret = count; 439 *err = 0; 440 return ret; 441 failed_out: 442 for (i = 0; i <index; i++) 443 ext2_free_blocks(inode, new_blocks[i], 1); 444 if (index) 445 mark_inode_dirty(inode); 446 return ret; 447 } 448 449 /** 450 * ext2_alloc_branch - allocate and set up a chain of blocks. 451 * @inode: owner 452 * @num: depth of the chain (number of blocks to allocate) 453 * @offsets: offsets (in the blocks) to store the pointers to next. 454 * @branch: place to store the chain in. 455 * 456 * This function allocates @num blocks, zeroes out all but the last one, 457 * links them into chain and (if we are synchronous) writes them to disk. 458 * In other words, it prepares a branch that can be spliced onto the 459 * inode. It stores the information about that chain in the branch[], in 460 * the same format as ext2_get_branch() would do. We are calling it after 461 * we had read the existing part of chain and partial points to the last 462 * triple of that (one with zero ->key). Upon the exit we have the same 463 * picture as after the successful ext2_get_block(), except that in one 464 * place chain is disconnected - *branch->p is still zero (we did not 465 * set the last link), but branch->key contains the number that should 466 * be placed into *branch->p to fill that gap. 467 * 468 * If allocation fails we free all blocks we've allocated (and forget 469 * their buffer_heads) and return the error value the from failed 470 * ext2_alloc_block() (normally -ENOSPC). Otherwise we set the chain 471 * as described above and return 0. 472 */ 473 474 static int ext2_alloc_branch(struct inode *inode, 475 int indirect_blks, int *blks, ext2_fsblk_t goal, 476 int *offsets, Indirect *branch) 477 { 478 int blocksize = inode->i_sb->s_blocksize; 479 int i, n = 0; 480 int err = 0; 481 struct buffer_head *bh; 482 int num; 483 ext2_fsblk_t new_blocks[4]; 484 ext2_fsblk_t current_block; 485 486 num = ext2_alloc_blocks(inode, goal, indirect_blks, 487 *blks, new_blocks, &err); 488 if (err) 489 return err; 490 491 branch[0].key = cpu_to_le32(new_blocks[0]); 492 /* 493 * metadata blocks and data blocks are allocated. 494 */ 495 for (n = 1; n <= indirect_blks; n++) { 496 /* 497 * Get buffer_head for parent block, zero it out 498 * and set the pointer to new one, then send 499 * parent to disk. 500 */ 501 bh = sb_getblk(inode->i_sb, new_blocks[n-1]); 502 if (unlikely(!bh)) { 503 err = -ENOMEM; 504 goto failed; 505 } 506 branch[n].bh = bh; 507 lock_buffer(bh); 508 memset(bh->b_data, 0, blocksize); 509 branch[n].p = (__le32 *) bh->b_data + offsets[n]; 510 branch[n].key = cpu_to_le32(new_blocks[n]); 511 *branch[n].p = branch[n].key; 512 if ( n == indirect_blks) { 513 current_block = new_blocks[n]; 514 /* 515 * End of chain, update the last new metablock of 516 * the chain to point to the new allocated 517 * data blocks numbers 518 */ 519 for (i=1; i < num; i++) 520 *(branch[n].p + i) = cpu_to_le32(++current_block); 521 } 522 set_buffer_uptodate(bh); 523 unlock_buffer(bh); 524 mark_buffer_dirty_inode(bh, inode); 525 /* We used to sync bh here if IS_SYNC(inode). 526 * But we now rely upon generic_write_sync() 527 * and b_inode_buffers. But not for directories. 528 */ 529 if (S_ISDIR(inode->i_mode) && IS_DIRSYNC(inode)) 530 sync_dirty_buffer(bh); 531 } 532 *blks = num; 533 return err; 534 535 failed: 536 for (i = 1; i < n; i++) 537 bforget(branch[i].bh); 538 for (i = 0; i < indirect_blks; i++) 539 ext2_free_blocks(inode, new_blocks[i], 1); 540 ext2_free_blocks(inode, new_blocks[i], num); 541 return err; 542 } 543 544 /** 545 * ext2_splice_branch - splice the allocated branch onto inode. 546 * @inode: owner 547 * @block: (logical) number of block we are adding 548 * @where: location of missing link 549 * @num: number of indirect blocks we are adding 550 * @blks: number of direct blocks we are adding 551 * 552 * This function fills the missing link and does all housekeeping needed in 553 * inode (->i_blocks, etc.). In case of success we end up with the full 554 * chain to new block and return 0. 555 */ 556 static void ext2_splice_branch(struct inode *inode, 557 long block, Indirect *where, int num, int blks) 558 { 559 int i; 560 struct ext2_block_alloc_info *block_i; 561 ext2_fsblk_t current_block; 562 563 block_i = EXT2_I(inode)->i_block_alloc_info; 564 565 /* XXX LOCKING probably should have i_meta_lock ?*/ 566 /* That's it */ 567 568 *where->p = where->key; 569 570 /* 571 * Update the host buffer_head or inode to point to more just allocated 572 * direct blocks blocks 573 */ 574 if (num == 0 && blks > 1) { 575 current_block = le32_to_cpu(where->key) + 1; 576 for (i = 1; i < blks; i++) 577 *(where->p + i ) = cpu_to_le32(current_block++); 578 } 579 580 /* 581 * update the most recently allocated logical & physical block 582 * in i_block_alloc_info, to assist find the proper goal block for next 583 * allocation 584 */ 585 if (block_i) { 586 block_i->last_alloc_logical_block = block + blks - 1; 587 block_i->last_alloc_physical_block = 588 le32_to_cpu(where[num].key) + blks - 1; 589 } 590 591 /* We are done with atomic stuff, now do the rest of housekeeping */ 592 593 /* had we spliced it onto indirect block? */ 594 if (where->bh) 595 mark_buffer_dirty_inode(where->bh, inode); 596 597 inode->i_ctime = CURRENT_TIME_SEC; 598 mark_inode_dirty(inode); 599 } 600 601 /* 602 * Allocation strategy is simple: if we have to allocate something, we will 603 * have to go the whole way to leaf. So let's do it before attaching anything 604 * to tree, set linkage between the newborn blocks, write them if sync is 605 * required, recheck the path, free and repeat if check fails, otherwise 606 * set the last missing link (that will protect us from any truncate-generated 607 * removals - all blocks on the path are immune now) and possibly force the 608 * write on the parent block. 609 * That has a nice additional property: no special recovery from the failed 610 * allocations is needed - we simply release blocks and do not touch anything 611 * reachable from inode. 612 * 613 * `handle' can be NULL if create == 0. 614 * 615 * return > 0, # of blocks mapped or allocated. 616 * return = 0, if plain lookup failed. 617 * return < 0, error case. 618 */ 619 static int ext2_get_blocks(struct inode *inode, 620 sector_t iblock, unsigned long maxblocks, 621 struct buffer_head *bh_result, 622 int create) 623 { 624 int err = -EIO; 625 int offsets[4]; 626 Indirect chain[4]; 627 Indirect *partial; 628 ext2_fsblk_t goal; 629 int indirect_blks; 630 int blocks_to_boundary = 0; 631 int depth; 632 struct ext2_inode_info *ei = EXT2_I(inode); 633 int count = 0; 634 ext2_fsblk_t first_block = 0; 635 636 BUG_ON(maxblocks == 0); 637 638 depth = ext2_block_to_path(inode,iblock,offsets,&blocks_to_boundary); 639 640 if (depth == 0) 641 return (err); 642 643 partial = ext2_get_branch(inode, depth, offsets, chain, &err); 644 /* Simplest case - block found, no allocation needed */ 645 if (!partial) { 646 first_block = le32_to_cpu(chain[depth - 1].key); 647 clear_buffer_new(bh_result); /* What's this do? */ 648 count++; 649 /*map more blocks*/ 650 while (count < maxblocks && count <= blocks_to_boundary) { 651 ext2_fsblk_t blk; 652 653 if (!verify_chain(chain, chain + depth - 1)) { 654 /* 655 * Indirect block might be removed by 656 * truncate while we were reading it. 657 * Handling of that case: forget what we've 658 * got now, go to reread. 659 */ 660 err = -EAGAIN; 661 count = 0; 662 break; 663 } 664 blk = le32_to_cpu(*(chain[depth-1].p + count)); 665 if (blk == first_block + count) 666 count++; 667 else 668 break; 669 } 670 if (err != -EAGAIN) 671 goto got_it; 672 } 673 674 /* Next simple case - plain lookup or failed read of indirect block */ 675 if (!create || err == -EIO) 676 goto cleanup; 677 678 mutex_lock(&ei->truncate_mutex); 679 /* 680 * If the indirect block is missing while we are reading 681 * the chain(ext2_get_branch() returns -EAGAIN err), or 682 * if the chain has been changed after we grab the semaphore, 683 * (either because another process truncated this branch, or 684 * another get_block allocated this branch) re-grab the chain to see if 685 * the request block has been allocated or not. 686 * 687 * Since we already block the truncate/other get_block 688 * at this point, we will have the current copy of the chain when we 689 * splice the branch into the tree. 690 */ 691 if (err == -EAGAIN || !verify_chain(chain, partial)) { 692 while (partial > chain) { 693 brelse(partial->bh); 694 partial--; 695 } 696 partial = ext2_get_branch(inode, depth, offsets, chain, &err); 697 if (!partial) { 698 count++; 699 mutex_unlock(&ei->truncate_mutex); 700 if (err) 701 goto cleanup; 702 clear_buffer_new(bh_result); 703 goto got_it; 704 } 705 } 706 707 /* 708 * Okay, we need to do block allocation. Lazily initialize the block 709 * allocation info here if necessary 710 */ 711 if (S_ISREG(inode->i_mode) && (!ei->i_block_alloc_info)) 712 ext2_init_block_alloc_info(inode); 713 714 goal = ext2_find_goal(inode, iblock, partial); 715 716 /* the number of blocks need to allocate for [d,t]indirect blocks */ 717 indirect_blks = (chain + depth) - partial - 1; 718 /* 719 * Next look up the indirect map to count the totoal number of 720 * direct blocks to allocate for this branch. 721 */ 722 count = ext2_blks_to_allocate(partial, indirect_blks, 723 maxblocks, blocks_to_boundary); 724 /* 725 * XXX ???? Block out ext2_truncate while we alter the tree 726 */ 727 err = ext2_alloc_branch(inode, indirect_blks, &count, goal, 728 offsets + (partial - chain), partial); 729 730 if (err) { 731 mutex_unlock(&ei->truncate_mutex); 732 goto cleanup; 733 } 734 735 if (IS_DAX(inode)) { 736 /* 737 * block must be initialised before we put it in the tree 738 * so that it's not found by another thread before it's 739 * initialised 740 */ 741 err = sb_issue_zeroout(inode->i_sb, 742 le32_to_cpu(chain[depth-1].key), count, 743 GFP_NOFS); 744 if (err) { 745 mutex_unlock(&ei->truncate_mutex); 746 goto cleanup; 747 } 748 } else 749 set_buffer_new(bh_result); 750 751 ext2_splice_branch(inode, iblock, partial, indirect_blks, count); 752 mutex_unlock(&ei->truncate_mutex); 753 got_it: 754 map_bh(bh_result, inode->i_sb, le32_to_cpu(chain[depth-1].key)); 755 if (count > blocks_to_boundary) 756 set_buffer_boundary(bh_result); 757 err = count; 758 /* Clean up and exit */ 759 partial = chain + depth - 1; /* the whole chain */ 760 cleanup: 761 while (partial > chain) { 762 brelse(partial->bh); 763 partial--; 764 } 765 return err; 766 } 767 768 int ext2_get_block(struct inode *inode, sector_t iblock, struct buffer_head *bh_result, int create) 769 { 770 unsigned max_blocks = bh_result->b_size >> inode->i_blkbits; 771 int ret = ext2_get_blocks(inode, iblock, max_blocks, 772 bh_result, create); 773 if (ret > 0) { 774 bh_result->b_size = (ret << inode->i_blkbits); 775 ret = 0; 776 } 777 return ret; 778 779 } 780 781 int ext2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, 782 u64 start, u64 len) 783 { 784 return generic_block_fiemap(inode, fieinfo, start, len, 785 ext2_get_block); 786 } 787 788 static int ext2_writepage(struct page *page, struct writeback_control *wbc) 789 { 790 return block_write_full_page(page, ext2_get_block, wbc); 791 } 792 793 static int ext2_readpage(struct file *file, struct page *page) 794 { 795 return mpage_readpage(page, ext2_get_block); 796 } 797 798 static int 799 ext2_readpages(struct file *file, struct address_space *mapping, 800 struct list_head *pages, unsigned nr_pages) 801 { 802 return mpage_readpages(mapping, pages, nr_pages, ext2_get_block); 803 } 804 805 static int 806 ext2_write_begin(struct file *file, struct address_space *mapping, 807 loff_t pos, unsigned len, unsigned flags, 808 struct page **pagep, void **fsdata) 809 { 810 int ret; 811 812 ret = block_write_begin(mapping, pos, len, flags, pagep, 813 ext2_get_block); 814 if (ret < 0) 815 ext2_write_failed(mapping, pos + len); 816 return ret; 817 } 818 819 static int ext2_write_end(struct file *file, struct address_space *mapping, 820 loff_t pos, unsigned len, unsigned copied, 821 struct page *page, void *fsdata) 822 { 823 int ret; 824 825 ret = generic_write_end(file, mapping, pos, len, copied, page, fsdata); 826 if (ret < len) 827 ext2_write_failed(mapping, pos + len); 828 return ret; 829 } 830 831 static int 832 ext2_nobh_write_begin(struct file *file, struct address_space *mapping, 833 loff_t pos, unsigned len, unsigned flags, 834 struct page **pagep, void **fsdata) 835 { 836 int ret; 837 838 ret = nobh_write_begin(mapping, pos, len, flags, pagep, fsdata, 839 ext2_get_block); 840 if (ret < 0) 841 ext2_write_failed(mapping, pos + len); 842 return ret; 843 } 844 845 static int ext2_nobh_writepage(struct page *page, 846 struct writeback_control *wbc) 847 { 848 return nobh_writepage(page, ext2_get_block, wbc); 849 } 850 851 static sector_t ext2_bmap(struct address_space *mapping, sector_t block) 852 { 853 return generic_block_bmap(mapping,block,ext2_get_block); 854 } 855 856 static ssize_t 857 ext2_direct_IO(struct kiocb *iocb, struct iov_iter *iter) 858 { 859 struct file *file = iocb->ki_filp; 860 struct address_space *mapping = file->f_mapping; 861 struct inode *inode = mapping->host; 862 size_t count = iov_iter_count(iter); 863 loff_t offset = iocb->ki_pos; 864 ssize_t ret; 865 866 if (IS_DAX(inode)) 867 ret = dax_do_io(iocb, inode, iter, ext2_get_block, NULL, 868 DIO_LOCKING); 869 else 870 ret = blockdev_direct_IO(iocb, inode, iter, ext2_get_block); 871 if (ret < 0 && iov_iter_rw(iter) == WRITE) 872 ext2_write_failed(mapping, offset + count); 873 return ret; 874 } 875 876 static int 877 ext2_writepages(struct address_space *mapping, struct writeback_control *wbc) 878 { 879 #ifdef CONFIG_FS_DAX 880 if (dax_mapping(mapping)) { 881 return dax_writeback_mapping_range(mapping, 882 mapping->host->i_sb->s_bdev, 883 wbc); 884 } 885 #endif 886 887 return mpage_writepages(mapping, wbc, ext2_get_block); 888 } 889 890 const struct address_space_operations ext2_aops = { 891 .readpage = ext2_readpage, 892 .readpages = ext2_readpages, 893 .writepage = ext2_writepage, 894 .write_begin = ext2_write_begin, 895 .write_end = ext2_write_end, 896 .bmap = ext2_bmap, 897 .direct_IO = ext2_direct_IO, 898 .writepages = ext2_writepages, 899 .migratepage = buffer_migrate_page, 900 .is_partially_uptodate = block_is_partially_uptodate, 901 .error_remove_page = generic_error_remove_page, 902 }; 903 904 const struct address_space_operations ext2_nobh_aops = { 905 .readpage = ext2_readpage, 906 .readpages = ext2_readpages, 907 .writepage = ext2_nobh_writepage, 908 .write_begin = ext2_nobh_write_begin, 909 .write_end = nobh_write_end, 910 .bmap = ext2_bmap, 911 .direct_IO = ext2_direct_IO, 912 .writepages = ext2_writepages, 913 .migratepage = buffer_migrate_page, 914 .error_remove_page = generic_error_remove_page, 915 }; 916 917 /* 918 * Probably it should be a library function... search for first non-zero word 919 * or memcmp with zero_page, whatever is better for particular architecture. 920 * Linus? 921 */ 922 static inline int all_zeroes(__le32 *p, __le32 *q) 923 { 924 while (p < q) 925 if (*p++) 926 return 0; 927 return 1; 928 } 929 930 /** 931 * ext2_find_shared - find the indirect blocks for partial truncation. 932 * @inode: inode in question 933 * @depth: depth of the affected branch 934 * @offsets: offsets of pointers in that branch (see ext2_block_to_path) 935 * @chain: place to store the pointers to partial indirect blocks 936 * @top: place to the (detached) top of branch 937 * 938 * This is a helper function used by ext2_truncate(). 939 * 940 * When we do truncate() we may have to clean the ends of several indirect 941 * blocks but leave the blocks themselves alive. Block is partially 942 * truncated if some data below the new i_size is referred from it (and 943 * it is on the path to the first completely truncated data block, indeed). 944 * We have to free the top of that path along with everything to the right 945 * of the path. Since no allocation past the truncation point is possible 946 * until ext2_truncate() finishes, we may safely do the latter, but top 947 * of branch may require special attention - pageout below the truncation 948 * point might try to populate it. 949 * 950 * We atomically detach the top of branch from the tree, store the block 951 * number of its root in *@top, pointers to buffer_heads of partially 952 * truncated blocks - in @chain[].bh and pointers to their last elements 953 * that should not be removed - in @chain[].p. Return value is the pointer 954 * to last filled element of @chain. 955 * 956 * The work left to caller to do the actual freeing of subtrees: 957 * a) free the subtree starting from *@top 958 * b) free the subtrees whose roots are stored in 959 * (@chain[i].p+1 .. end of @chain[i].bh->b_data) 960 * c) free the subtrees growing from the inode past the @chain[0].p 961 * (no partially truncated stuff there). 962 */ 963 964 static Indirect *ext2_find_shared(struct inode *inode, 965 int depth, 966 int offsets[4], 967 Indirect chain[4], 968 __le32 *top) 969 { 970 Indirect *partial, *p; 971 int k, err; 972 973 *top = 0; 974 for (k = depth; k > 1 && !offsets[k-1]; k--) 975 ; 976 partial = ext2_get_branch(inode, k, offsets, chain, &err); 977 if (!partial) 978 partial = chain + k-1; 979 /* 980 * If the branch acquired continuation since we've looked at it - 981 * fine, it should all survive and (new) top doesn't belong to us. 982 */ 983 write_lock(&EXT2_I(inode)->i_meta_lock); 984 if (!partial->key && *partial->p) { 985 write_unlock(&EXT2_I(inode)->i_meta_lock); 986 goto no_top; 987 } 988 for (p=partial; p>chain && all_zeroes((__le32*)p->bh->b_data,p->p); p--) 989 ; 990 /* 991 * OK, we've found the last block that must survive. The rest of our 992 * branch should be detached before unlocking. However, if that rest 993 * of branch is all ours and does not grow immediately from the inode 994 * it's easier to cheat and just decrement partial->p. 995 */ 996 if (p == chain + k - 1 && p > chain) { 997 p->p--; 998 } else { 999 *top = *p->p; 1000 *p->p = 0; 1001 } 1002 write_unlock(&EXT2_I(inode)->i_meta_lock); 1003 1004 while(partial > p) 1005 { 1006 brelse(partial->bh); 1007 partial--; 1008 } 1009 no_top: 1010 return partial; 1011 } 1012 1013 /** 1014 * ext2_free_data - free a list of data blocks 1015 * @inode: inode we are dealing with 1016 * @p: array of block numbers 1017 * @q: points immediately past the end of array 1018 * 1019 * We are freeing all blocks referred from that array (numbers are 1020 * stored as little-endian 32-bit) and updating @inode->i_blocks 1021 * appropriately. 1022 */ 1023 static inline void ext2_free_data(struct inode *inode, __le32 *p, __le32 *q) 1024 { 1025 unsigned long block_to_free = 0, count = 0; 1026 unsigned long nr; 1027 1028 for ( ; p < q ; p++) { 1029 nr = le32_to_cpu(*p); 1030 if (nr) { 1031 *p = 0; 1032 /* accumulate blocks to free if they're contiguous */ 1033 if (count == 0) 1034 goto free_this; 1035 else if (block_to_free == nr - count) 1036 count++; 1037 else { 1038 ext2_free_blocks (inode, block_to_free, count); 1039 mark_inode_dirty(inode); 1040 free_this: 1041 block_to_free = nr; 1042 count = 1; 1043 } 1044 } 1045 } 1046 if (count > 0) { 1047 ext2_free_blocks (inode, block_to_free, count); 1048 mark_inode_dirty(inode); 1049 } 1050 } 1051 1052 /** 1053 * ext2_free_branches - free an array of branches 1054 * @inode: inode we are dealing with 1055 * @p: array of block numbers 1056 * @q: pointer immediately past the end of array 1057 * @depth: depth of the branches to free 1058 * 1059 * We are freeing all blocks referred from these branches (numbers are 1060 * stored as little-endian 32-bit) and updating @inode->i_blocks 1061 * appropriately. 1062 */ 1063 static void ext2_free_branches(struct inode *inode, __le32 *p, __le32 *q, int depth) 1064 { 1065 struct buffer_head * bh; 1066 unsigned long nr; 1067 1068 if (depth--) { 1069 int addr_per_block = EXT2_ADDR_PER_BLOCK(inode->i_sb); 1070 for ( ; p < q ; p++) { 1071 nr = le32_to_cpu(*p); 1072 if (!nr) 1073 continue; 1074 *p = 0; 1075 bh = sb_bread(inode->i_sb, nr); 1076 /* 1077 * A read failure? Report error and clear slot 1078 * (should be rare). 1079 */ 1080 if (!bh) { 1081 ext2_error(inode->i_sb, "ext2_free_branches", 1082 "Read failure, inode=%ld, block=%ld", 1083 inode->i_ino, nr); 1084 continue; 1085 } 1086 ext2_free_branches(inode, 1087 (__le32*)bh->b_data, 1088 (__le32*)bh->b_data + addr_per_block, 1089 depth); 1090 bforget(bh); 1091 ext2_free_blocks(inode, nr, 1); 1092 mark_inode_dirty(inode); 1093 } 1094 } else 1095 ext2_free_data(inode, p, q); 1096 } 1097 1098 /* dax_sem must be held when calling this function */ 1099 static void __ext2_truncate_blocks(struct inode *inode, loff_t offset) 1100 { 1101 __le32 *i_data = EXT2_I(inode)->i_data; 1102 struct ext2_inode_info *ei = EXT2_I(inode); 1103 int addr_per_block = EXT2_ADDR_PER_BLOCK(inode->i_sb); 1104 int offsets[4]; 1105 Indirect chain[4]; 1106 Indirect *partial; 1107 __le32 nr = 0; 1108 int n; 1109 long iblock; 1110 unsigned blocksize; 1111 blocksize = inode->i_sb->s_blocksize; 1112 iblock = (offset + blocksize-1) >> EXT2_BLOCK_SIZE_BITS(inode->i_sb); 1113 1114 #ifdef CONFIG_FS_DAX 1115 WARN_ON(!rwsem_is_locked(&ei->dax_sem)); 1116 #endif 1117 1118 n = ext2_block_to_path(inode, iblock, offsets, NULL); 1119 if (n == 0) 1120 return; 1121 1122 /* 1123 * From here we block out all ext2_get_block() callers who want to 1124 * modify the block allocation tree. 1125 */ 1126 mutex_lock(&ei->truncate_mutex); 1127 1128 if (n == 1) { 1129 ext2_free_data(inode, i_data+offsets[0], 1130 i_data + EXT2_NDIR_BLOCKS); 1131 goto do_indirects; 1132 } 1133 1134 partial = ext2_find_shared(inode, n, offsets, chain, &nr); 1135 /* Kill the top of shared branch (already detached) */ 1136 if (nr) { 1137 if (partial == chain) 1138 mark_inode_dirty(inode); 1139 else 1140 mark_buffer_dirty_inode(partial->bh, inode); 1141 ext2_free_branches(inode, &nr, &nr+1, (chain+n-1) - partial); 1142 } 1143 /* Clear the ends of indirect blocks on the shared branch */ 1144 while (partial > chain) { 1145 ext2_free_branches(inode, 1146 partial->p + 1, 1147 (__le32*)partial->bh->b_data+addr_per_block, 1148 (chain+n-1) - partial); 1149 mark_buffer_dirty_inode(partial->bh, inode); 1150 brelse (partial->bh); 1151 partial--; 1152 } 1153 do_indirects: 1154 /* Kill the remaining (whole) subtrees */ 1155 switch (offsets[0]) { 1156 default: 1157 nr = i_data[EXT2_IND_BLOCK]; 1158 if (nr) { 1159 i_data[EXT2_IND_BLOCK] = 0; 1160 mark_inode_dirty(inode); 1161 ext2_free_branches(inode, &nr, &nr+1, 1); 1162 } 1163 case EXT2_IND_BLOCK: 1164 nr = i_data[EXT2_DIND_BLOCK]; 1165 if (nr) { 1166 i_data[EXT2_DIND_BLOCK] = 0; 1167 mark_inode_dirty(inode); 1168 ext2_free_branches(inode, &nr, &nr+1, 2); 1169 } 1170 case EXT2_DIND_BLOCK: 1171 nr = i_data[EXT2_TIND_BLOCK]; 1172 if (nr) { 1173 i_data[EXT2_TIND_BLOCK] = 0; 1174 mark_inode_dirty(inode); 1175 ext2_free_branches(inode, &nr, &nr+1, 3); 1176 } 1177 case EXT2_TIND_BLOCK: 1178 ; 1179 } 1180 1181 ext2_discard_reservation(inode); 1182 1183 mutex_unlock(&ei->truncate_mutex); 1184 } 1185 1186 static void ext2_truncate_blocks(struct inode *inode, loff_t offset) 1187 { 1188 /* 1189 * XXX: it seems like a bug here that we don't allow 1190 * IS_APPEND inode to have blocks-past-i_size trimmed off. 1191 * review and fix this. 1192 * 1193 * Also would be nice to be able to handle IO errors and such, 1194 * but that's probably too much to ask. 1195 */ 1196 if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || 1197 S_ISLNK(inode->i_mode))) 1198 return; 1199 if (ext2_inode_is_fast_symlink(inode)) 1200 return; 1201 if (IS_APPEND(inode) || IS_IMMUTABLE(inode)) 1202 return; 1203 1204 dax_sem_down_write(EXT2_I(inode)); 1205 __ext2_truncate_blocks(inode, offset); 1206 dax_sem_up_write(EXT2_I(inode)); 1207 } 1208 1209 static int ext2_setsize(struct inode *inode, loff_t newsize) 1210 { 1211 int error; 1212 1213 if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || 1214 S_ISLNK(inode->i_mode))) 1215 return -EINVAL; 1216 if (ext2_inode_is_fast_symlink(inode)) 1217 return -EINVAL; 1218 if (IS_APPEND(inode) || IS_IMMUTABLE(inode)) 1219 return -EPERM; 1220 1221 inode_dio_wait(inode); 1222 1223 if (IS_DAX(inode)) 1224 error = dax_truncate_page(inode, newsize, ext2_get_block); 1225 else if (test_opt(inode->i_sb, NOBH)) 1226 error = nobh_truncate_page(inode->i_mapping, 1227 newsize, ext2_get_block); 1228 else 1229 error = block_truncate_page(inode->i_mapping, 1230 newsize, ext2_get_block); 1231 if (error) 1232 return error; 1233 1234 dax_sem_down_write(EXT2_I(inode)); 1235 truncate_setsize(inode, newsize); 1236 __ext2_truncate_blocks(inode, newsize); 1237 dax_sem_up_write(EXT2_I(inode)); 1238 1239 inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC; 1240 if (inode_needs_sync(inode)) { 1241 sync_mapping_buffers(inode->i_mapping); 1242 sync_inode_metadata(inode, 1); 1243 } else { 1244 mark_inode_dirty(inode); 1245 } 1246 1247 return 0; 1248 } 1249 1250 static struct ext2_inode *ext2_get_inode(struct super_block *sb, ino_t ino, 1251 struct buffer_head **p) 1252 { 1253 struct buffer_head * bh; 1254 unsigned long block_group; 1255 unsigned long block; 1256 unsigned long offset; 1257 struct ext2_group_desc * gdp; 1258 1259 *p = NULL; 1260 if ((ino != EXT2_ROOT_INO && ino < EXT2_FIRST_INO(sb)) || 1261 ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count)) 1262 goto Einval; 1263 1264 block_group = (ino - 1) / EXT2_INODES_PER_GROUP(sb); 1265 gdp = ext2_get_group_desc(sb, block_group, NULL); 1266 if (!gdp) 1267 goto Egdp; 1268 /* 1269 * Figure out the offset within the block group inode table 1270 */ 1271 offset = ((ino - 1) % EXT2_INODES_PER_GROUP(sb)) * EXT2_INODE_SIZE(sb); 1272 block = le32_to_cpu(gdp->bg_inode_table) + 1273 (offset >> EXT2_BLOCK_SIZE_BITS(sb)); 1274 if (!(bh = sb_bread(sb, block))) 1275 goto Eio; 1276 1277 *p = bh; 1278 offset &= (EXT2_BLOCK_SIZE(sb) - 1); 1279 return (struct ext2_inode *) (bh->b_data + offset); 1280 1281 Einval: 1282 ext2_error(sb, "ext2_get_inode", "bad inode number: %lu", 1283 (unsigned long) ino); 1284 return ERR_PTR(-EINVAL); 1285 Eio: 1286 ext2_error(sb, "ext2_get_inode", 1287 "unable to read inode block - inode=%lu, block=%lu", 1288 (unsigned long) ino, block); 1289 Egdp: 1290 return ERR_PTR(-EIO); 1291 } 1292 1293 void ext2_set_inode_flags(struct inode *inode) 1294 { 1295 unsigned int flags = EXT2_I(inode)->i_flags; 1296 1297 inode->i_flags &= ~(S_SYNC | S_APPEND | S_IMMUTABLE | S_NOATIME | 1298 S_DIRSYNC | S_DAX); 1299 if (flags & EXT2_SYNC_FL) 1300 inode->i_flags |= S_SYNC; 1301 if (flags & EXT2_APPEND_FL) 1302 inode->i_flags |= S_APPEND; 1303 if (flags & EXT2_IMMUTABLE_FL) 1304 inode->i_flags |= S_IMMUTABLE; 1305 if (flags & EXT2_NOATIME_FL) 1306 inode->i_flags |= S_NOATIME; 1307 if (flags & EXT2_DIRSYNC_FL) 1308 inode->i_flags |= S_DIRSYNC; 1309 if (test_opt(inode->i_sb, DAX) && S_ISREG(inode->i_mode)) 1310 inode->i_flags |= S_DAX; 1311 } 1312 1313 /* Propagate flags from i_flags to EXT2_I(inode)->i_flags */ 1314 void ext2_get_inode_flags(struct ext2_inode_info *ei) 1315 { 1316 unsigned int flags = ei->vfs_inode.i_flags; 1317 1318 ei->i_flags &= ~(EXT2_SYNC_FL|EXT2_APPEND_FL| 1319 EXT2_IMMUTABLE_FL|EXT2_NOATIME_FL|EXT2_DIRSYNC_FL); 1320 if (flags & S_SYNC) 1321 ei->i_flags |= EXT2_SYNC_FL; 1322 if (flags & S_APPEND) 1323 ei->i_flags |= EXT2_APPEND_FL; 1324 if (flags & S_IMMUTABLE) 1325 ei->i_flags |= EXT2_IMMUTABLE_FL; 1326 if (flags & S_NOATIME) 1327 ei->i_flags |= EXT2_NOATIME_FL; 1328 if (flags & S_DIRSYNC) 1329 ei->i_flags |= EXT2_DIRSYNC_FL; 1330 } 1331 1332 struct inode *ext2_iget (struct super_block *sb, unsigned long ino) 1333 { 1334 struct ext2_inode_info *ei; 1335 struct buffer_head * bh; 1336 struct ext2_inode *raw_inode; 1337 struct inode *inode; 1338 long ret = -EIO; 1339 int n; 1340 uid_t i_uid; 1341 gid_t i_gid; 1342 1343 inode = iget_locked(sb, ino); 1344 if (!inode) 1345 return ERR_PTR(-ENOMEM); 1346 if (!(inode->i_state & I_NEW)) 1347 return inode; 1348 1349 ei = EXT2_I(inode); 1350 ei->i_block_alloc_info = NULL; 1351 1352 raw_inode = ext2_get_inode(inode->i_sb, ino, &bh); 1353 if (IS_ERR(raw_inode)) { 1354 ret = PTR_ERR(raw_inode); 1355 goto bad_inode; 1356 } 1357 1358 inode->i_mode = le16_to_cpu(raw_inode->i_mode); 1359 i_uid = (uid_t)le16_to_cpu(raw_inode->i_uid_low); 1360 i_gid = (gid_t)le16_to_cpu(raw_inode->i_gid_low); 1361 if (!(test_opt (inode->i_sb, NO_UID32))) { 1362 i_uid |= le16_to_cpu(raw_inode->i_uid_high) << 16; 1363 i_gid |= le16_to_cpu(raw_inode->i_gid_high) << 16; 1364 } 1365 i_uid_write(inode, i_uid); 1366 i_gid_write(inode, i_gid); 1367 set_nlink(inode, le16_to_cpu(raw_inode->i_links_count)); 1368 inode->i_size = le32_to_cpu(raw_inode->i_size); 1369 inode->i_atime.tv_sec = (signed)le32_to_cpu(raw_inode->i_atime); 1370 inode->i_ctime.tv_sec = (signed)le32_to_cpu(raw_inode->i_ctime); 1371 inode->i_mtime.tv_sec = (signed)le32_to_cpu(raw_inode->i_mtime); 1372 inode->i_atime.tv_nsec = inode->i_mtime.tv_nsec = inode->i_ctime.tv_nsec = 0; 1373 ei->i_dtime = le32_to_cpu(raw_inode->i_dtime); 1374 /* We now have enough fields to check if the inode was active or not. 1375 * This is needed because nfsd might try to access dead inodes 1376 * the test is that same one that e2fsck uses 1377 * NeilBrown 1999oct15 1378 */ 1379 if (inode->i_nlink == 0 && (inode->i_mode == 0 || ei->i_dtime)) { 1380 /* this inode is deleted */ 1381 brelse (bh); 1382 ret = -ESTALE; 1383 goto bad_inode; 1384 } 1385 inode->i_blocks = le32_to_cpu(raw_inode->i_blocks); 1386 ei->i_flags = le32_to_cpu(raw_inode->i_flags); 1387 ei->i_faddr = le32_to_cpu(raw_inode->i_faddr); 1388 ei->i_frag_no = raw_inode->i_frag; 1389 ei->i_frag_size = raw_inode->i_fsize; 1390 ei->i_file_acl = le32_to_cpu(raw_inode->i_file_acl); 1391 ei->i_dir_acl = 0; 1392 1393 if (ei->i_file_acl && 1394 !ext2_data_block_valid(EXT2_SB(sb), ei->i_file_acl, 1)) { 1395 ext2_error(sb, "ext2_iget", "bad extended attribute block %u", 1396 ei->i_file_acl); 1397 brelse(bh); 1398 ret = -EFSCORRUPTED; 1399 goto bad_inode; 1400 } 1401 1402 if (S_ISREG(inode->i_mode)) 1403 inode->i_size |= ((__u64)le32_to_cpu(raw_inode->i_size_high)) << 32; 1404 else 1405 ei->i_dir_acl = le32_to_cpu(raw_inode->i_dir_acl); 1406 ei->i_dtime = 0; 1407 inode->i_generation = le32_to_cpu(raw_inode->i_generation); 1408 ei->i_state = 0; 1409 ei->i_block_group = (ino - 1) / EXT2_INODES_PER_GROUP(inode->i_sb); 1410 ei->i_dir_start_lookup = 0; 1411 1412 /* 1413 * NOTE! The in-memory inode i_data array is in little-endian order 1414 * even on big-endian machines: we do NOT byteswap the block numbers! 1415 */ 1416 for (n = 0; n < EXT2_N_BLOCKS; n++) 1417 ei->i_data[n] = raw_inode->i_block[n]; 1418 1419 if (S_ISREG(inode->i_mode)) { 1420 inode->i_op = &ext2_file_inode_operations; 1421 if (test_opt(inode->i_sb, NOBH)) { 1422 inode->i_mapping->a_ops = &ext2_nobh_aops; 1423 inode->i_fop = &ext2_file_operations; 1424 } else { 1425 inode->i_mapping->a_ops = &ext2_aops; 1426 inode->i_fop = &ext2_file_operations; 1427 } 1428 } else if (S_ISDIR(inode->i_mode)) { 1429 inode->i_op = &ext2_dir_inode_operations; 1430 inode->i_fop = &ext2_dir_operations; 1431 if (test_opt(inode->i_sb, NOBH)) 1432 inode->i_mapping->a_ops = &ext2_nobh_aops; 1433 else 1434 inode->i_mapping->a_ops = &ext2_aops; 1435 } else if (S_ISLNK(inode->i_mode)) { 1436 if (ext2_inode_is_fast_symlink(inode)) { 1437 inode->i_link = (char *)ei->i_data; 1438 inode->i_op = &ext2_fast_symlink_inode_operations; 1439 nd_terminate_link(ei->i_data, inode->i_size, 1440 sizeof(ei->i_data) - 1); 1441 } else { 1442 inode->i_op = &ext2_symlink_inode_operations; 1443 inode_nohighmem(inode); 1444 if (test_opt(inode->i_sb, NOBH)) 1445 inode->i_mapping->a_ops = &ext2_nobh_aops; 1446 else 1447 inode->i_mapping->a_ops = &ext2_aops; 1448 } 1449 } else { 1450 inode->i_op = &ext2_special_inode_operations; 1451 if (raw_inode->i_block[0]) 1452 init_special_inode(inode, inode->i_mode, 1453 old_decode_dev(le32_to_cpu(raw_inode->i_block[0]))); 1454 else 1455 init_special_inode(inode, inode->i_mode, 1456 new_decode_dev(le32_to_cpu(raw_inode->i_block[1]))); 1457 } 1458 brelse (bh); 1459 ext2_set_inode_flags(inode); 1460 unlock_new_inode(inode); 1461 return inode; 1462 1463 bad_inode: 1464 iget_failed(inode); 1465 return ERR_PTR(ret); 1466 } 1467 1468 static int __ext2_write_inode(struct inode *inode, int do_sync) 1469 { 1470 struct ext2_inode_info *ei = EXT2_I(inode); 1471 struct super_block *sb = inode->i_sb; 1472 ino_t ino = inode->i_ino; 1473 uid_t uid = i_uid_read(inode); 1474 gid_t gid = i_gid_read(inode); 1475 struct buffer_head * bh; 1476 struct ext2_inode * raw_inode = ext2_get_inode(sb, ino, &bh); 1477 int n; 1478 int err = 0; 1479 1480 if (IS_ERR(raw_inode)) 1481 return -EIO; 1482 1483 /* For fields not not tracking in the in-memory inode, 1484 * initialise them to zero for new inodes. */ 1485 if (ei->i_state & EXT2_STATE_NEW) 1486 memset(raw_inode, 0, EXT2_SB(sb)->s_inode_size); 1487 1488 ext2_get_inode_flags(ei); 1489 raw_inode->i_mode = cpu_to_le16(inode->i_mode); 1490 if (!(test_opt(sb, NO_UID32))) { 1491 raw_inode->i_uid_low = cpu_to_le16(low_16_bits(uid)); 1492 raw_inode->i_gid_low = cpu_to_le16(low_16_bits(gid)); 1493 /* 1494 * Fix up interoperability with old kernels. Otherwise, old inodes get 1495 * re-used with the upper 16 bits of the uid/gid intact 1496 */ 1497 if (!ei->i_dtime) { 1498 raw_inode->i_uid_high = cpu_to_le16(high_16_bits(uid)); 1499 raw_inode->i_gid_high = cpu_to_le16(high_16_bits(gid)); 1500 } else { 1501 raw_inode->i_uid_high = 0; 1502 raw_inode->i_gid_high = 0; 1503 } 1504 } else { 1505 raw_inode->i_uid_low = cpu_to_le16(fs_high2lowuid(uid)); 1506 raw_inode->i_gid_low = cpu_to_le16(fs_high2lowgid(gid)); 1507 raw_inode->i_uid_high = 0; 1508 raw_inode->i_gid_high = 0; 1509 } 1510 raw_inode->i_links_count = cpu_to_le16(inode->i_nlink); 1511 raw_inode->i_size = cpu_to_le32(inode->i_size); 1512 raw_inode->i_atime = cpu_to_le32(inode->i_atime.tv_sec); 1513 raw_inode->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec); 1514 raw_inode->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec); 1515 1516 raw_inode->i_blocks = cpu_to_le32(inode->i_blocks); 1517 raw_inode->i_dtime = cpu_to_le32(ei->i_dtime); 1518 raw_inode->i_flags = cpu_to_le32(ei->i_flags); 1519 raw_inode->i_faddr = cpu_to_le32(ei->i_faddr); 1520 raw_inode->i_frag = ei->i_frag_no; 1521 raw_inode->i_fsize = ei->i_frag_size; 1522 raw_inode->i_file_acl = cpu_to_le32(ei->i_file_acl); 1523 if (!S_ISREG(inode->i_mode)) 1524 raw_inode->i_dir_acl = cpu_to_le32(ei->i_dir_acl); 1525 else { 1526 raw_inode->i_size_high = cpu_to_le32(inode->i_size >> 32); 1527 if (inode->i_size > 0x7fffffffULL) { 1528 if (!EXT2_HAS_RO_COMPAT_FEATURE(sb, 1529 EXT2_FEATURE_RO_COMPAT_LARGE_FILE) || 1530 EXT2_SB(sb)->s_es->s_rev_level == 1531 cpu_to_le32(EXT2_GOOD_OLD_REV)) { 1532 /* If this is the first large file 1533 * created, add a flag to the superblock. 1534 */ 1535 spin_lock(&EXT2_SB(sb)->s_lock); 1536 ext2_update_dynamic_rev(sb); 1537 EXT2_SET_RO_COMPAT_FEATURE(sb, 1538 EXT2_FEATURE_RO_COMPAT_LARGE_FILE); 1539 spin_unlock(&EXT2_SB(sb)->s_lock); 1540 ext2_write_super(sb); 1541 } 1542 } 1543 } 1544 1545 raw_inode->i_generation = cpu_to_le32(inode->i_generation); 1546 if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) { 1547 if (old_valid_dev(inode->i_rdev)) { 1548 raw_inode->i_block[0] = 1549 cpu_to_le32(old_encode_dev(inode->i_rdev)); 1550 raw_inode->i_block[1] = 0; 1551 } else { 1552 raw_inode->i_block[0] = 0; 1553 raw_inode->i_block[1] = 1554 cpu_to_le32(new_encode_dev(inode->i_rdev)); 1555 raw_inode->i_block[2] = 0; 1556 } 1557 } else for (n = 0; n < EXT2_N_BLOCKS; n++) 1558 raw_inode->i_block[n] = ei->i_data[n]; 1559 mark_buffer_dirty(bh); 1560 if (do_sync) { 1561 sync_dirty_buffer(bh); 1562 if (buffer_req(bh) && !buffer_uptodate(bh)) { 1563 printk ("IO error syncing ext2 inode [%s:%08lx]\n", 1564 sb->s_id, (unsigned long) ino); 1565 err = -EIO; 1566 } 1567 } 1568 ei->i_state &= ~EXT2_STATE_NEW; 1569 brelse (bh); 1570 return err; 1571 } 1572 1573 int ext2_write_inode(struct inode *inode, struct writeback_control *wbc) 1574 { 1575 return __ext2_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL); 1576 } 1577 1578 int ext2_setattr(struct dentry *dentry, struct iattr *iattr) 1579 { 1580 struct inode *inode = d_inode(dentry); 1581 int error; 1582 1583 error = inode_change_ok(inode, iattr); 1584 if (error) 1585 return error; 1586 1587 if (is_quota_modification(inode, iattr)) { 1588 error = dquot_initialize(inode); 1589 if (error) 1590 return error; 1591 } 1592 if ((iattr->ia_valid & ATTR_UID && !uid_eq(iattr->ia_uid, inode->i_uid)) || 1593 (iattr->ia_valid & ATTR_GID && !gid_eq(iattr->ia_gid, inode->i_gid))) { 1594 error = dquot_transfer(inode, iattr); 1595 if (error) 1596 return error; 1597 } 1598 if (iattr->ia_valid & ATTR_SIZE && iattr->ia_size != inode->i_size) { 1599 error = ext2_setsize(inode, iattr->ia_size); 1600 if (error) 1601 return error; 1602 } 1603 setattr_copy(inode, iattr); 1604 if (iattr->ia_valid & ATTR_MODE) 1605 error = posix_acl_chmod(inode, inode->i_mode); 1606 mark_inode_dirty(inode); 1607 1608 return error; 1609 } 1610