1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * linux/fs/ext2/inode.c 4 * 5 * Copyright (C) 1992, 1993, 1994, 1995 6 * Remy Card (card@masi.ibp.fr) 7 * Laboratoire MASI - Institut Blaise Pascal 8 * Universite Pierre et Marie Curie (Paris VI) 9 * 10 * from 11 * 12 * linux/fs/minix/inode.c 13 * 14 * Copyright (C) 1991, 1992 Linus Torvalds 15 * 16 * Goal-directed block allocation by Stephen Tweedie 17 * (sct@dcs.ed.ac.uk), 1993, 1998 18 * Big-endian to little-endian byte-swapping/bitmaps by 19 * David S. Miller (davem@caip.rutgers.edu), 1995 20 * 64-bit file support on 64-bit platforms by Jakub Jelinek 21 * (jj@sunsite.ms.mff.cuni.cz) 22 * 23 * Assorted race fixes, rewrite of ext2_get_block() by Al Viro, 2000 24 */ 25 26 #include <linux/time.h> 27 #include <linux/highuid.h> 28 #include <linux/pagemap.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/iomap.h> 36 #include <linux/namei.h> 37 #include <linux/uio.h> 38 #include "ext2.h" 39 #include "acl.h" 40 #include "xattr.h" 41 42 static int __ext2_write_inode(struct inode *inode, int do_sync); 43 44 /* 45 * Test whether an inode is a fast symlink. 46 */ 47 static inline int ext2_inode_is_fast_symlink(struct inode *inode) 48 { 49 int ea_blocks = EXT2_I(inode)->i_file_acl ? 50 (inode->i_sb->s_blocksize >> 9) : 0; 51 52 return (S_ISLNK(inode->i_mode) && 53 inode->i_blocks - ea_blocks == 0); 54 } 55 56 static void ext2_truncate_blocks(struct inode *inode, loff_t offset); 57 58 void ext2_write_failed(struct address_space *mapping, loff_t to) 59 { 60 struct inode *inode = mapping->host; 61 62 if (to > inode->i_size) { 63 truncate_pagecache(inode, inode->i_size); 64 ext2_truncate_blocks(inode, inode->i_size); 65 } 66 } 67 68 /* 69 * Called at the last iput() if i_nlink is zero. 70 */ 71 void ext2_evict_inode(struct inode * inode) 72 { 73 struct ext2_block_alloc_info *rsv; 74 int want_delete = 0; 75 76 if (!inode->i_nlink && !is_bad_inode(inode)) { 77 want_delete = 1; 78 dquot_initialize(inode); 79 } else { 80 dquot_drop(inode); 81 } 82 83 truncate_inode_pages_final(&inode->i_data); 84 85 if (want_delete) { 86 sb_start_intwrite(inode->i_sb); 87 /* set dtime */ 88 EXT2_I(inode)->i_dtime = ktime_get_real_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 ext2_xattr_delete_inode(inode); 96 } else { 97 mmb_sync(&EXT2_I(inode)->i_metadata_bhs); 98 } 99 mmb_invalidate(&EXT2_I(inode)->i_metadata_bhs); 100 clear_inode(inode); 101 102 ext2_discard_reservation(inode); 103 rsv = EXT2_I(inode)->i_block_alloc_info; 104 EXT2_I(inode)->i_block_alloc_info = NULL; 105 if (unlikely(rsv)) 106 kfree(rsv); 107 108 if (want_delete) { 109 ext2_free_inode(inode); 110 sb_end_intwrite(inode->i_sb); 111 } 112 } 113 114 typedef struct { 115 __le32 *p; 116 __le32 key; 117 struct buffer_head *bh; 118 } Indirect; 119 120 static inline void add_chain(Indirect *p, struct buffer_head *bh, __le32 *v) 121 { 122 p->key = *(p->p = v); 123 p->bh = bh; 124 } 125 126 static inline int verify_chain(Indirect *from, Indirect *to) 127 { 128 while (from <= to && from->key == *from->p) 129 from++; 130 return (from > to); 131 } 132 133 /** 134 * ext2_block_to_path - parse the block number into array of offsets 135 * @inode: inode in question (we are only interested in its superblock) 136 * @i_block: block number to be parsed 137 * @offsets: array to store the offsets in 138 * @boundary: set this non-zero if the referred-to block is likely to be 139 * followed (on disk) by an indirect block. 140 * To store the locations of file's data ext2 uses a data structure common 141 * for UNIX filesystems - tree of pointers anchored in the inode, with 142 * data blocks at leaves and indirect blocks in intermediate nodes. 143 * This function translates the block number into path in that tree - 144 * return value is the path length and @offsets[n] is the offset of 145 * pointer to (n+1)th node in the nth one. If @block is out of range 146 * (negative or too large) warning is printed and zero returned. 147 * 148 * Note: function doesn't find node addresses, so no IO is needed. All 149 * we need to know is the capacity of indirect blocks (taken from the 150 * inode->i_sb). 151 */ 152 153 /* 154 * Portability note: the last comparison (check that we fit into triple 155 * indirect block) is spelled differently, because otherwise on an 156 * architecture with 32-bit longs and 8Kb pages we might get into trouble 157 * if our filesystem had 8Kb blocks. We might use long long, but that would 158 * kill us on x86. Oh, well, at least the sign propagation does not matter - 159 * i_block would have to be negative in the very beginning, so we would not 160 * get there at all. 161 */ 162 163 static int ext2_block_to_path(struct inode *inode, 164 long i_block, int offsets[4], int *boundary) 165 { 166 int ptrs = EXT2_ADDR_PER_BLOCK(inode->i_sb); 167 int ptrs_bits = EXT2_ADDR_PER_BLOCK_BITS(inode->i_sb); 168 const long direct_blocks = EXT2_NDIR_BLOCKS, 169 indirect_blocks = ptrs, 170 double_blocks = (1 << (ptrs_bits * 2)); 171 int n = 0; 172 int final = 0; 173 174 if (i_block < 0) { 175 ext2_msg(inode->i_sb, KERN_WARNING, 176 "warning: %s: block < 0", __func__); 177 } else if (i_block < direct_blocks) { 178 offsets[n++] = i_block; 179 final = direct_blocks; 180 } else if ( (i_block -= direct_blocks) < indirect_blocks) { 181 offsets[n++] = EXT2_IND_BLOCK; 182 offsets[n++] = i_block; 183 final = ptrs; 184 } else if ((i_block -= indirect_blocks) < double_blocks) { 185 offsets[n++] = EXT2_DIND_BLOCK; 186 offsets[n++] = i_block >> ptrs_bits; 187 offsets[n++] = i_block & (ptrs - 1); 188 final = ptrs; 189 } else if (((i_block -= double_blocks) >> (ptrs_bits * 2)) < ptrs) { 190 offsets[n++] = EXT2_TIND_BLOCK; 191 offsets[n++] = i_block >> (ptrs_bits * 2); 192 offsets[n++] = (i_block >> ptrs_bits) & (ptrs - 1); 193 offsets[n++] = i_block & (ptrs - 1); 194 final = ptrs; 195 } else { 196 ext2_msg(inode->i_sb, KERN_WARNING, 197 "warning: %s: block is too big", __func__); 198 } 199 if (boundary) 200 *boundary = final - 1 - (i_block & (ptrs - 1)); 201 202 return n; 203 } 204 205 /** 206 * ext2_get_branch - read the chain of indirect blocks leading to data 207 * @inode: inode in question 208 * @depth: depth of the chain (1 - direct pointer, etc.) 209 * @offsets: offsets of pointers in inode/indirect blocks 210 * @chain: place to store the result 211 * @err: here we store the error value 212 * 213 * Function fills the array of triples <key, p, bh> and returns %NULL 214 * if everything went OK or the pointer to the last filled triple 215 * (incomplete one) otherwise. Upon the return chain[i].key contains 216 * the number of (i+1)-th block in the chain (as it is stored in memory, 217 * i.e. little-endian 32-bit), chain[i].p contains the address of that 218 * number (it points into struct inode for i==0 and into the bh->b_data 219 * for i>0) and chain[i].bh points to the buffer_head of i-th indirect 220 * block for i>0 and NULL for i==0. In other words, it holds the block 221 * numbers of the chain, addresses they were taken from (and where we can 222 * verify that chain did not change) and buffer_heads hosting these 223 * numbers. 224 * 225 * Function stops when it stumbles upon zero pointer (absent block) 226 * (pointer to last triple returned, *@err == 0) 227 * or when it gets an IO error reading an indirect block 228 * (ditto, *@err == -EIO) 229 * or when it notices that chain had been changed while it was reading 230 * (ditto, *@err == -EAGAIN) 231 * or when it reads all @depth-1 indirect blocks successfully and finds 232 * the whole chain, all way to the data (returns %NULL, *err == 0). 233 */ 234 static Indirect *ext2_get_branch(struct inode *inode, 235 int depth, 236 int *offsets, 237 Indirect chain[4], 238 int *err) 239 { 240 struct super_block *sb = inode->i_sb; 241 Indirect *p = chain; 242 struct buffer_head *bh; 243 244 *err = 0; 245 /* i_data is not going away, no lock needed */ 246 add_chain (chain, NULL, EXT2_I(inode)->i_data + *offsets); 247 if (!p->key) 248 goto no_block; 249 while (--depth) { 250 bh = sb_bread(sb, le32_to_cpu(p->key)); 251 if (!bh) 252 goto failure; 253 read_lock(&EXT2_I(inode)->i_meta_lock); 254 if (!verify_chain(chain, p)) 255 goto changed; 256 add_chain(++p, bh, (__le32*)bh->b_data + *++offsets); 257 read_unlock(&EXT2_I(inode)->i_meta_lock); 258 if (!p->key) 259 goto no_block; 260 } 261 return NULL; 262 263 changed: 264 read_unlock(&EXT2_I(inode)->i_meta_lock); 265 brelse(bh); 266 *err = -EAGAIN; 267 goto no_block; 268 failure: 269 *err = -EIO; 270 no_block: 271 return p; 272 } 273 274 /** 275 * ext2_find_near - find a place for allocation with sufficient locality 276 * @inode: owner 277 * @ind: descriptor of indirect block. 278 * 279 * This function returns the preferred place for block allocation. 280 * It is used when heuristic for sequential allocation fails. 281 * Rules are: 282 * + if there is a block to the left of our position - allocate near it. 283 * + if pointer will live in indirect block - allocate near that block. 284 * + if pointer will live in inode - allocate in the same cylinder group. 285 * 286 * In the latter case we colour the starting block by the callers PID to 287 * prevent it from clashing with concurrent allocations for a different inode 288 * in the same block group. The PID is used here so that functionally related 289 * files will be close-by on-disk. 290 * 291 * Caller must make sure that @ind is valid and will stay that way. 292 */ 293 294 static ext2_fsblk_t ext2_find_near(struct inode *inode, Indirect *ind) 295 { 296 struct ext2_inode_info *ei = EXT2_I(inode); 297 __le32 *start = ind->bh ? (__le32 *) ind->bh->b_data : ei->i_data; 298 __le32 *p; 299 ext2_fsblk_t bg_start; 300 ext2_fsblk_t colour; 301 302 /* Try to find previous block */ 303 for (p = ind->p - 1; p >= start; p--) 304 if (*p) 305 return le32_to_cpu(*p); 306 307 /* No such thing, so let's try location of indirect block */ 308 if (ind->bh) 309 return ind->bh->b_blocknr; 310 311 /* 312 * It is going to be referred from inode itself? OK, just put it into 313 * the same cylinder group then. 314 */ 315 bg_start = ext2_group_first_block_no(inode->i_sb, ei->i_block_group); 316 colour = (current->pid % 16) * 317 (EXT2_BLOCKS_PER_GROUP(inode->i_sb) / 16); 318 return bg_start + colour; 319 } 320 321 /** 322 * ext2_find_goal - find a preferred place for allocation. 323 * @inode: owner 324 * @block: block we want 325 * @partial: pointer to the last triple within a chain 326 * 327 * Returns preferred place for a block (the goal). 328 */ 329 330 static inline ext2_fsblk_t ext2_find_goal(struct inode *inode, long block, 331 Indirect *partial) 332 { 333 struct ext2_block_alloc_info *block_i; 334 335 block_i = EXT2_I(inode)->i_block_alloc_info; 336 337 /* 338 * try the heuristic for sequential allocation, 339 * failing that at least try to get decent locality. 340 */ 341 if (block_i && (block == block_i->last_alloc_logical_block + 1) 342 && (block_i->last_alloc_physical_block != 0)) { 343 return block_i->last_alloc_physical_block + 1; 344 } 345 346 return ext2_find_near(inode, partial); 347 } 348 349 /** 350 * ext2_blks_to_allocate: Look up the block map and count the number 351 * of direct blocks need to be allocated for the given branch. 352 * 353 * @branch: chain of indirect blocks 354 * @k: number of blocks need for indirect blocks 355 * @blks: number of data blocks to be mapped. 356 * @blocks_to_boundary: the offset in the indirect block 357 * 358 * return the number of direct blocks to allocate. 359 */ 360 static int 361 ext2_blks_to_allocate(Indirect * branch, int k, unsigned long blks, 362 int blocks_to_boundary) 363 { 364 unsigned long count = 0; 365 366 /* 367 * Simple case, [t,d]Indirect block(s) has not allocated yet 368 * then it's clear blocks on that path have not allocated 369 */ 370 if (k > 0) { 371 /* right now don't hanel cross boundary allocation */ 372 if (blks < blocks_to_boundary + 1) 373 count += blks; 374 else 375 count += blocks_to_boundary + 1; 376 return count; 377 } 378 379 count++; 380 while (count < blks && count <= blocks_to_boundary 381 && le32_to_cpu(*(branch[0].p + count)) == 0) { 382 count++; 383 } 384 return count; 385 } 386 387 /** 388 * ext2_alloc_blocks: Allocate multiple blocks needed for a branch. 389 * @inode: Owner. 390 * @goal: Preferred place for allocation. 391 * @indirect_blks: The number of blocks needed to allocate for indirect blocks. 392 * @blks: The number of blocks need to allocate for direct blocks. 393 * @new_blocks: On return it will store the new block numbers for 394 * the indirect blocks(if needed) and the first direct block. 395 * @err: Error pointer. 396 * 397 * Return: Number of blocks allocated. 398 */ 399 static int ext2_alloc_blocks(struct inode *inode, 400 ext2_fsblk_t goal, int indirect_blks, int blks, 401 ext2_fsblk_t new_blocks[4], int *err) 402 { 403 int target, i; 404 unsigned long count = 0; 405 int index = 0; 406 ext2_fsblk_t current_block = 0; 407 int ret = 0; 408 409 /* 410 * Here we try to allocate the requested multiple blocks at once, 411 * on a best-effort basis. 412 * To build a branch, we should allocate blocks for 413 * the indirect blocks(if not allocated yet), and at least 414 * the first direct block of this branch. That's the 415 * minimum number of blocks need to allocate(required) 416 */ 417 target = blks + indirect_blks; 418 419 while (1) { 420 count = target; 421 /* allocating blocks for indirect blocks and direct blocks */ 422 current_block = ext2_new_blocks(inode, goal, &count, err, 0); 423 if (*err) 424 goto failed_out; 425 426 target -= count; 427 /* allocate blocks for indirect blocks */ 428 while (index < indirect_blks && count) { 429 new_blocks[index++] = current_block++; 430 count--; 431 } 432 433 if (count > 0) 434 break; 435 } 436 437 /* save the new block number for the first direct block */ 438 new_blocks[index] = current_block; 439 440 /* total number of blocks allocated for direct blocks */ 441 ret = count; 442 *err = 0; 443 return ret; 444 failed_out: 445 for (i = 0; i <index; i++) 446 ext2_free_blocks(inode, new_blocks[i], 1); 447 if (index) 448 mark_inode_dirty(inode); 449 return ret; 450 } 451 452 /** 453 * ext2_alloc_branch - allocate and set up a chain of blocks. 454 * @inode: owner 455 * @indirect_blks: depth of the chain (number of blocks to allocate) 456 * @blks: number of allocated direct blocks 457 * @goal: preferred place for allocation 458 * @offsets: offsets (in the blocks) to store the pointers to next. 459 * @branch: place to store the chain in. 460 * 461 * This function allocates @num blocks, zeroes out all but the last one, 462 * links them into chain and (if we are synchronous) writes them to disk. 463 * In other words, it prepares a branch that can be spliced onto the 464 * inode. It stores the information about that chain in the branch[], in 465 * the same format as ext2_get_branch() would do. We are calling it after 466 * we had read the existing part of chain and partial points to the last 467 * triple of that (one with zero ->key). Upon the exit we have the same 468 * picture as after the successful ext2_get_block(), except that in one 469 * place chain is disconnected - *branch->p is still zero (we did not 470 * set the last link), but branch->key contains the number that should 471 * be placed into *branch->p to fill that gap. 472 * 473 * If allocation fails we free all blocks we've allocated (and forget 474 * their buffer_heads) and return the error value the from failed 475 * ext2_alloc_block() (normally -ENOSPC). Otherwise we set the chain 476 * as described above and return 0. 477 */ 478 479 static int ext2_alloc_branch(struct inode *inode, 480 int indirect_blks, int *blks, ext2_fsblk_t goal, 481 int *offsets, Indirect *branch) 482 { 483 int blocksize = inode->i_sb->s_blocksize; 484 int i, n = 0; 485 int err = 0; 486 struct buffer_head *bh; 487 int num; 488 ext2_fsblk_t new_blocks[4]; 489 ext2_fsblk_t current_block; 490 491 num = ext2_alloc_blocks(inode, goal, indirect_blks, 492 *blks, new_blocks, &err); 493 if (err) 494 return err; 495 496 branch[0].key = cpu_to_le32(new_blocks[0]); 497 /* 498 * metadata blocks and data blocks are allocated. 499 */ 500 for (n = 1; n <= indirect_blks; n++) { 501 /* 502 * Get buffer_head for parent block, zero it out 503 * and set the pointer to new one, then send 504 * parent to disk. 505 */ 506 bh = sb_getblk(inode->i_sb, new_blocks[n-1]); 507 if (unlikely(!bh)) { 508 err = -ENOMEM; 509 goto failed; 510 } 511 branch[n].bh = bh; 512 lock_buffer(bh); 513 memset(bh->b_data, 0, blocksize); 514 branch[n].p = (__le32 *) bh->b_data + offsets[n]; 515 branch[n].key = cpu_to_le32(new_blocks[n]); 516 *branch[n].p = branch[n].key; 517 if ( n == indirect_blks) { 518 current_block = new_blocks[n]; 519 /* 520 * End of chain, update the last new metablock of 521 * the chain to point to the new allocated 522 * data blocks numbers 523 */ 524 for (i=1; i < num; i++) 525 *(branch[n].p + i) = cpu_to_le32(++current_block); 526 } 527 set_buffer_uptodate(bh); 528 unlock_buffer(bh); 529 mmb_mark_buffer_dirty(bh, &EXT2_I(inode)->i_metadata_bhs); 530 /* We used to sync bh here if IS_SYNC(inode). 531 * But we now rely upon generic_write_sync() 532 * and b_inode_buffers. But not for directories. 533 */ 534 if (S_ISDIR(inode->i_mode) && IS_DIRSYNC(inode)) 535 sync_dirty_buffer(bh); 536 } 537 *blks = num; 538 return err; 539 540 failed: 541 for (i = 1; i < n; i++) 542 bforget(branch[i].bh); 543 for (i = 0; i < indirect_blks; i++) 544 ext2_free_blocks(inode, new_blocks[i], 1); 545 ext2_free_blocks(inode, new_blocks[i], num); 546 return err; 547 } 548 549 /** 550 * ext2_splice_branch - splice the allocated branch onto inode. 551 * @inode: owner 552 * @block: (logical) number of block we are adding 553 * @where: location of missing link 554 * @num: number of indirect blocks we are adding 555 * @blks: number of direct blocks we are adding 556 * 557 * This function fills the missing link and does all housekeeping needed in 558 * inode (->i_blocks, etc.). In case of success we end up with the full 559 * chain to new block and return 0. 560 */ 561 static void ext2_splice_branch(struct inode *inode, 562 long block, Indirect *where, int num, int blks) 563 { 564 int i; 565 struct ext2_block_alloc_info *block_i; 566 ext2_fsblk_t current_block; 567 568 block_i = EXT2_I(inode)->i_block_alloc_info; 569 570 /* XXX LOCKING probably should have i_meta_lock ?*/ 571 /* That's it */ 572 573 *where->p = where->key; 574 575 /* 576 * Update the host buffer_head or inode to point to more just allocated 577 * direct blocks blocks 578 */ 579 if (num == 0 && blks > 1) { 580 current_block = le32_to_cpu(where->key) + 1; 581 for (i = 1; i < blks; i++) 582 *(where->p + i ) = cpu_to_le32(current_block++); 583 } 584 585 /* 586 * update the most recently allocated logical & physical block 587 * in i_block_alloc_info, to assist find the proper goal block for next 588 * allocation 589 */ 590 if (block_i) { 591 block_i->last_alloc_logical_block = block + blks - 1; 592 block_i->last_alloc_physical_block = 593 le32_to_cpu(where[num].key) + blks - 1; 594 } 595 596 /* We are done with atomic stuff, now do the rest of housekeeping */ 597 598 /* had we spliced it onto indirect block? */ 599 if (where->bh) 600 mmb_mark_buffer_dirty(where->bh, &EXT2_I(inode)->i_metadata_bhs); 601 602 inode_set_ctime_current(inode); 603 mark_inode_dirty(inode); 604 } 605 606 /* 607 * Allocation strategy is simple: if we have to allocate something, we will 608 * have to go the whole way to leaf. So let's do it before attaching anything 609 * to tree, set linkage between the newborn blocks, write them if sync is 610 * required, recheck the path, free and repeat if check fails, otherwise 611 * set the last missing link (that will protect us from any truncate-generated 612 * removals - all blocks on the path are immune now) and possibly force the 613 * write on the parent block. 614 * That has a nice additional property: no special recovery from the failed 615 * allocations is needed - we simply release blocks and do not touch anything 616 * reachable from inode. 617 * 618 * `handle' can be NULL if create == 0. 619 * 620 * return > 0, # of blocks mapped or allocated. 621 * return = 0, if plain lookup failed. 622 * return < 0, error case. 623 */ 624 static int ext2_get_blocks(struct inode *inode, 625 sector_t iblock, unsigned long maxblocks, 626 u32 *bno, bool *new, bool *boundary, 627 int create) 628 { 629 int err; 630 int offsets[4]; 631 Indirect chain[4]; 632 Indirect *partial; 633 ext2_fsblk_t goal; 634 int indirect_blks; 635 int blocks_to_boundary = 0; 636 int depth; 637 struct ext2_inode_info *ei = EXT2_I(inode); 638 int count = 0; 639 ext2_fsblk_t first_block = 0; 640 641 if (WARN_ON_ONCE(maxblocks == 0)) 642 return -EINVAL; 643 644 depth = ext2_block_to_path(inode,iblock,offsets,&blocks_to_boundary); 645 646 if (depth == 0) 647 return -EIO; 648 649 partial = ext2_get_branch(inode, depth, offsets, chain, &err); 650 /* Simplest case - block found, no allocation needed */ 651 if (!partial) { 652 first_block = le32_to_cpu(chain[depth - 1].key); 653 count++; 654 /*map more blocks*/ 655 while (count < maxblocks && count <= blocks_to_boundary) { 656 ext2_fsblk_t blk; 657 658 if (!verify_chain(chain, chain + depth - 1)) { 659 /* 660 * Indirect block might be removed by 661 * truncate while we were reading it. 662 * Handling of that case: forget what we've 663 * got now, go to reread. 664 */ 665 err = -EAGAIN; 666 count = 0; 667 partial = chain + depth - 1; 668 break; 669 } 670 blk = le32_to_cpu(*(chain[depth-1].p + count)); 671 if (blk == first_block + count) 672 count++; 673 else 674 break; 675 } 676 if (err != -EAGAIN) 677 goto got_it; 678 } 679 680 /* Next simple case - plain lookup or failed read of indirect block */ 681 if (!create || err == -EIO) 682 goto cleanup; 683 684 mutex_lock(&ei->truncate_mutex); 685 /* 686 * If the indirect block is missing while we are reading 687 * the chain(ext2_get_branch() returns -EAGAIN err), or 688 * if the chain has been changed after we grab the semaphore, 689 * (either because another process truncated this branch, or 690 * another get_block allocated this branch) re-grab the chain to see if 691 * the request block has been allocated or not. 692 * 693 * Since we already block the truncate/other get_block 694 * at this point, we will have the current copy of the chain when we 695 * splice the branch into the tree. 696 */ 697 if (err == -EAGAIN || !verify_chain(chain, partial)) { 698 while (partial > chain) { 699 brelse(partial->bh); 700 partial--; 701 } 702 partial = ext2_get_branch(inode, depth, offsets, chain, &err); 703 if (!partial) { 704 count++; 705 mutex_unlock(&ei->truncate_mutex); 706 goto got_it; 707 } 708 709 if (err) { 710 mutex_unlock(&ei->truncate_mutex); 711 goto cleanup; 712 } 713 } 714 715 /* 716 * Okay, we need to do block allocation. Lazily initialize the block 717 * allocation info here if necessary 718 */ 719 if (S_ISREG(inode->i_mode) && (!ei->i_block_alloc_info)) 720 ext2_init_block_alloc_info(inode); 721 722 goal = ext2_find_goal(inode, iblock, partial); 723 724 /* the number of blocks need to allocate for [d,t]indirect blocks */ 725 indirect_blks = (chain + depth) - partial - 1; 726 /* 727 * Next look up the indirect map to count the total number of 728 * direct blocks to allocate for this branch. 729 */ 730 count = ext2_blks_to_allocate(partial, indirect_blks, 731 maxblocks, blocks_to_boundary); 732 /* 733 * XXX ???? Block out ext2_truncate while we alter the tree 734 */ 735 err = ext2_alloc_branch(inode, indirect_blks, &count, goal, 736 offsets + (partial - chain), partial); 737 738 if (err) { 739 mutex_unlock(&ei->truncate_mutex); 740 goto cleanup; 741 } 742 743 *new = true; 744 745 ext2_splice_branch(inode, iblock, partial, indirect_blks, count); 746 mutex_unlock(&ei->truncate_mutex); 747 got_it: 748 if (count > blocks_to_boundary) 749 *boundary = true; 750 err = count; 751 /* Clean up and exit */ 752 partial = chain + depth - 1; /* the whole chain */ 753 cleanup: 754 while (partial > chain) { 755 brelse(partial->bh); 756 partial--; 757 } 758 if (err > 0) 759 *bno = le32_to_cpu(chain[depth-1].key); 760 return err; 761 } 762 763 int ext2_get_block(struct inode *inode, sector_t iblock, 764 struct buffer_head *bh_result, int create) 765 { 766 unsigned max_blocks = bh_result->b_size >> inode->i_blkbits; 767 bool new = false, boundary = false; 768 u32 bno; 769 int ret; 770 771 ret = ext2_get_blocks(inode, iblock, max_blocks, &bno, &new, &boundary, 772 create); 773 if (ret <= 0) 774 return ret; 775 776 map_bh(bh_result, inode->i_sb, bno); 777 bh_result->b_size = (ret << inode->i_blkbits); 778 if (new) 779 set_buffer_new(bh_result); 780 if (boundary) 781 set_buffer_boundary(bh_result); 782 return 0; 783 784 } 785 786 static int ext2_iomap_begin(struct inode *inode, loff_t offset, loff_t length, 787 unsigned flags, struct iomap *iomap, struct iomap *srcmap) 788 { 789 unsigned int blkbits = inode->i_blkbits; 790 unsigned long first_block = offset >> blkbits; 791 unsigned long max_blocks = (length + (1 << blkbits) - 1) >> blkbits; 792 bool new = false, boundary = false; 793 u32 bno; 794 int ret; 795 bool create = flags & IOMAP_WRITE; 796 797 /* 798 * For writes that could fill holes inside i_size on a 799 * DIO_SKIP_HOLES filesystem we forbid block creations: only 800 * overwrites are permitted. 801 */ 802 if ((flags & IOMAP_DIRECT) && 803 (first_block << blkbits) < i_size_read(inode)) 804 create = 0; 805 806 /* 807 * Writes that span EOF might trigger an IO size update on completion, 808 * so consider them to be dirty for the purposes of O_DSYNC even if 809 * there is no other metadata changes pending or have been made here. 810 */ 811 if ((flags & IOMAP_WRITE) && offset + length > i_size_read(inode)) 812 iomap->flags |= IOMAP_F_DIRTY; 813 814 ret = ext2_get_blocks(inode, first_block, max_blocks, 815 &bno, &new, &boundary, create); 816 if (ret < 0) 817 return ret; 818 819 iomap->flags = 0; 820 iomap->offset = (u64)first_block << blkbits; 821 iomap->bdev = inode->i_sb->s_bdev; 822 823 if (ret == 0) { 824 /* 825 * Switch to buffered-io for writing to holes in a non-extent 826 * based filesystem to avoid stale data exposure problem. 827 */ 828 if (!create && (flags & IOMAP_WRITE) && (flags & IOMAP_DIRECT)) 829 return -ENOTBLK; 830 iomap->type = IOMAP_HOLE; 831 iomap->addr = IOMAP_NULL_ADDR; 832 iomap->length = 1 << blkbits; 833 } else { 834 iomap->type = IOMAP_MAPPED; 835 iomap->addr = (u64)bno << blkbits; 836 iomap->length = (u64)ret << blkbits; 837 iomap->flags |= IOMAP_F_MERGED; 838 } 839 840 if (new) 841 iomap->flags |= IOMAP_F_NEW; 842 return 0; 843 } 844 845 static int 846 ext2_iomap_end(struct inode *inode, loff_t offset, loff_t length, 847 ssize_t written, unsigned flags, struct iomap *iomap) 848 { 849 /* 850 * Switch to buffered-io in case of any error. 851 * Blocks allocated can be used by the buffered-io path. 852 */ 853 if ((flags & IOMAP_DIRECT) && (flags & IOMAP_WRITE) && written == 0) 854 return -ENOTBLK; 855 856 if (iomap->type == IOMAP_MAPPED && 857 written < length && 858 (flags & IOMAP_WRITE)) 859 ext2_write_failed(inode->i_mapping, offset + length); 860 return 0; 861 } 862 863 const struct iomap_ops ext2_iomap_ops = { 864 .iomap_begin = ext2_iomap_begin, 865 .iomap_end = ext2_iomap_end, 866 }; 867 868 int ext2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, 869 u64 start, u64 len) 870 { 871 int ret; 872 loff_t i_size; 873 874 inode_lock(inode); 875 i_size = i_size_read(inode); 876 /* 877 * iomap_fiemap() returns EINVAL for 0 length. Make sure we don't trim 878 * length to 0 but still trim the range as much as possible since 879 * ext2_get_blocks() iterates unmapped space block by block which is 880 * slow. 881 */ 882 if (i_size == 0) 883 i_size = 1; 884 len = min_t(u64, len, i_size); 885 ret = iomap_fiemap(inode, fieinfo, start, len, &ext2_iomap_ops); 886 inode_unlock(inode); 887 888 return ret; 889 } 890 891 static int ext2_read_folio(struct file *file, struct folio *folio) 892 { 893 return mpage_read_folio(folio, ext2_get_block); 894 } 895 896 static void ext2_readahead(struct readahead_control *rac) 897 { 898 mpage_readahead(rac, ext2_get_block); 899 } 900 901 static int 902 ext2_write_begin(const struct kiocb *iocb, struct address_space *mapping, 903 loff_t pos, unsigned len, struct folio **foliop, void **fsdata) 904 { 905 int ret; 906 907 ret = block_write_begin(mapping, pos, len, foliop, ext2_get_block); 908 if (ret < 0) 909 ext2_write_failed(mapping, pos + len); 910 return ret; 911 } 912 913 static int ext2_write_end(const struct kiocb *iocb, 914 struct address_space *mapping, 915 loff_t pos, unsigned len, unsigned copied, 916 struct folio *folio, void *fsdata) 917 { 918 int ret; 919 920 ret = generic_write_end(iocb, mapping, pos, len, copied, folio, fsdata); 921 if (ret < len) 922 ext2_write_failed(mapping, pos + len); 923 return ret; 924 } 925 926 static sector_t ext2_bmap(struct address_space *mapping, sector_t block) 927 { 928 return generic_block_bmap(mapping,block,ext2_get_block); 929 } 930 931 static int 932 ext2_writepages(struct address_space *mapping, struct writeback_control *wbc) 933 { 934 return mpage_writepages(mapping, wbc, ext2_get_block); 935 } 936 937 938 const struct address_space_operations ext2_aops = { 939 .dirty_folio = block_dirty_folio, 940 .invalidate_folio = block_invalidate_folio, 941 .read_folio = ext2_read_folio, 942 .readahead = ext2_readahead, 943 .write_begin = ext2_write_begin, 944 .write_end = ext2_write_end, 945 .bmap = ext2_bmap, 946 .writepages = ext2_writepages, 947 .migrate_folio = buffer_migrate_folio, 948 .is_partially_uptodate = block_is_partially_uptodate, 949 .error_remove_folio = generic_error_remove_folio, 950 }; 951 952 953 /* 954 * Probably it should be a library function... search for first non-zero word 955 * or memcmp with zero_page, whatever is better for particular architecture. 956 * Linus? 957 */ 958 static inline int all_zeroes(__le32 *p, __le32 *q) 959 { 960 while (p < q) 961 if (*p++) 962 return 0; 963 return 1; 964 } 965 966 /** 967 * ext2_find_shared - find the indirect blocks for partial truncation. 968 * @inode: inode in question 969 * @depth: depth of the affected branch 970 * @offsets: offsets of pointers in that branch (see ext2_block_to_path) 971 * @chain: place to store the pointers to partial indirect blocks 972 * @top: place to the (detached) top of branch 973 * 974 * This is a helper function used by ext2_truncate(). 975 * 976 * When we do truncate() we may have to clean the ends of several indirect 977 * blocks but leave the blocks themselves alive. Block is partially 978 * truncated if some data below the new i_size is referred from it (and 979 * it is on the path to the first completely truncated data block, indeed). 980 * We have to free the top of that path along with everything to the right 981 * of the path. Since no allocation past the truncation point is possible 982 * until ext2_truncate() finishes, we may safely do the latter, but top 983 * of branch may require special attention - pageout below the truncation 984 * point might try to populate it. 985 * 986 * We atomically detach the top of branch from the tree, store the block 987 * number of its root in *@top, pointers to buffer_heads of partially 988 * truncated blocks - in @chain[].bh and pointers to their last elements 989 * that should not be removed - in @chain[].p. Return value is the pointer 990 * to last filled element of @chain. 991 * 992 * The work left to caller to do the actual freeing of subtrees: 993 * a) free the subtree starting from *@top 994 * b) free the subtrees whose roots are stored in 995 * (@chain[i].p+1 .. end of @chain[i].bh->b_data) 996 * c) free the subtrees growing from the inode past the @chain[0].p 997 * (no partially truncated stuff there). 998 */ 999 1000 static Indirect *ext2_find_shared(struct inode *inode, 1001 int depth, 1002 int offsets[4], 1003 Indirect chain[4], 1004 __le32 *top) 1005 { 1006 Indirect *partial, *p; 1007 int k, err; 1008 1009 *top = 0; 1010 for (k = depth; k > 1 && !offsets[k-1]; k--) 1011 ; 1012 partial = ext2_get_branch(inode, k, offsets, chain, &err); 1013 if (!partial) 1014 partial = chain + k-1; 1015 /* 1016 * If the branch acquired continuation since we've looked at it - 1017 * fine, it should all survive and (new) top doesn't belong to us. 1018 */ 1019 write_lock(&EXT2_I(inode)->i_meta_lock); 1020 if (!partial->key && *partial->p) { 1021 write_unlock(&EXT2_I(inode)->i_meta_lock); 1022 goto no_top; 1023 } 1024 for (p=partial; p>chain && all_zeroes((__le32*)p->bh->b_data,p->p); p--) 1025 ; 1026 /* 1027 * OK, we've found the last block that must survive. The rest of our 1028 * branch should be detached before unlocking. However, if that rest 1029 * of branch is all ours and does not grow immediately from the inode 1030 * it's easier to cheat and just decrement partial->p. 1031 */ 1032 if (p == chain + k - 1 && p > chain) { 1033 p->p--; 1034 } else { 1035 *top = *p->p; 1036 *p->p = 0; 1037 } 1038 write_unlock(&EXT2_I(inode)->i_meta_lock); 1039 1040 while(partial > p) 1041 { 1042 brelse(partial->bh); 1043 partial--; 1044 } 1045 no_top: 1046 return partial; 1047 } 1048 1049 /** 1050 * ext2_free_data - free a list of data blocks 1051 * @inode: inode we are dealing with 1052 * @p: array of block numbers 1053 * @q: points immediately past the end of array 1054 * 1055 * We are freeing all blocks referred from that array (numbers are 1056 * stored as little-endian 32-bit) and updating @inode->i_blocks 1057 * appropriately. 1058 */ 1059 static inline void ext2_free_data(struct inode *inode, __le32 *p, __le32 *q) 1060 { 1061 ext2_fsblk_t block_to_free = 0, count = 0; 1062 ext2_fsblk_t nr; 1063 1064 for ( ; p < q ; p++) { 1065 nr = le32_to_cpu(*p); 1066 if (nr) { 1067 *p = 0; 1068 /* accumulate blocks to free if they're contiguous */ 1069 if (count == 0) 1070 goto free_this; 1071 else if (block_to_free == nr - count) 1072 count++; 1073 else { 1074 ext2_free_blocks (inode, block_to_free, count); 1075 mark_inode_dirty(inode); 1076 free_this: 1077 block_to_free = nr; 1078 count = 1; 1079 } 1080 } 1081 } 1082 if (count > 0) { 1083 ext2_free_blocks (inode, block_to_free, count); 1084 mark_inode_dirty(inode); 1085 } 1086 } 1087 1088 /** 1089 * ext2_free_branches - free an array of branches 1090 * @inode: inode we are dealing with 1091 * @p: array of block numbers 1092 * @q: pointer immediately past the end of array 1093 * @depth: depth of the branches to free 1094 * 1095 * We are freeing all blocks referred from these branches (numbers are 1096 * stored as little-endian 32-bit) and updating @inode->i_blocks 1097 * appropriately. 1098 */ 1099 static void ext2_free_branches(struct inode *inode, __le32 *p, __le32 *q, int depth) 1100 { 1101 struct buffer_head * bh; 1102 ext2_fsblk_t nr; 1103 1104 if (depth--) { 1105 int addr_per_block = EXT2_ADDR_PER_BLOCK(inode->i_sb); 1106 for ( ; p < q ; p++) { 1107 nr = le32_to_cpu(*p); 1108 if (!nr) 1109 continue; 1110 *p = 0; 1111 bh = sb_bread(inode->i_sb, nr); 1112 /* 1113 * A read failure? Report error and clear slot 1114 * (should be rare). 1115 */ 1116 if (!bh) { 1117 ext2_error(inode->i_sb, "ext2_free_branches", 1118 "Read failure, inode=%llu, block=%ld", 1119 inode->i_ino, nr); 1120 continue; 1121 } 1122 ext2_free_branches(inode, 1123 (__le32*)bh->b_data, 1124 (__le32*)bh->b_data + addr_per_block, 1125 depth); 1126 bforget(bh); 1127 ext2_free_blocks(inode, nr, 1); 1128 mark_inode_dirty(inode); 1129 } 1130 } else 1131 ext2_free_data(inode, p, q); 1132 } 1133 1134 /* mapping->invalidate_lock must be held when calling this function */ 1135 static void __ext2_truncate_blocks(struct inode *inode, loff_t offset) 1136 { 1137 __le32 *i_data = EXT2_I(inode)->i_data; 1138 struct ext2_inode_info *ei = EXT2_I(inode); 1139 int addr_per_block = EXT2_ADDR_PER_BLOCK(inode->i_sb); 1140 int offsets[4]; 1141 Indirect chain[4]; 1142 Indirect *partial; 1143 __le32 nr = 0; 1144 int n; 1145 long iblock; 1146 unsigned blocksize; 1147 blocksize = inode->i_sb->s_blocksize; 1148 iblock = (offset + blocksize-1) >> EXT2_BLOCK_SIZE_BITS(inode->i_sb); 1149 1150 1151 n = ext2_block_to_path(inode, iblock, offsets, NULL); 1152 if (n == 0) 1153 return; 1154 1155 /* 1156 * From here we block out all ext2_get_block() callers who want to 1157 * modify the block allocation tree. 1158 */ 1159 mutex_lock(&ei->truncate_mutex); 1160 1161 if (n == 1) { 1162 ext2_free_data(inode, i_data+offsets[0], 1163 i_data + EXT2_NDIR_BLOCKS); 1164 goto do_indirects; 1165 } 1166 1167 partial = ext2_find_shared(inode, n, offsets, chain, &nr); 1168 /* Kill the top of shared branch (already detached) */ 1169 if (nr) { 1170 if (partial == chain) 1171 mark_inode_dirty(inode); 1172 else 1173 mmb_mark_buffer_dirty(partial->bh, 1174 &EXT2_I(inode)->i_metadata_bhs); 1175 ext2_free_branches(inode, &nr, &nr+1, (chain+n-1) - partial); 1176 } 1177 /* Clear the ends of indirect blocks on the shared branch */ 1178 while (partial > chain) { 1179 ext2_free_branches(inode, 1180 partial->p + 1, 1181 (__le32*)partial->bh->b_data+addr_per_block, 1182 (chain+n-1) - partial); 1183 mmb_mark_buffer_dirty(partial->bh, 1184 &EXT2_I(inode)->i_metadata_bhs); 1185 brelse (partial->bh); 1186 partial--; 1187 } 1188 do_indirects: 1189 /* Kill the remaining (whole) subtrees */ 1190 switch (offsets[0]) { 1191 default: 1192 nr = i_data[EXT2_IND_BLOCK]; 1193 if (nr) { 1194 i_data[EXT2_IND_BLOCK] = 0; 1195 mark_inode_dirty(inode); 1196 ext2_free_branches(inode, &nr, &nr+1, 1); 1197 } 1198 fallthrough; 1199 case EXT2_IND_BLOCK: 1200 nr = i_data[EXT2_DIND_BLOCK]; 1201 if (nr) { 1202 i_data[EXT2_DIND_BLOCK] = 0; 1203 mark_inode_dirty(inode); 1204 ext2_free_branches(inode, &nr, &nr+1, 2); 1205 } 1206 fallthrough; 1207 case EXT2_DIND_BLOCK: 1208 nr = i_data[EXT2_TIND_BLOCK]; 1209 if (nr) { 1210 i_data[EXT2_TIND_BLOCK] = 0; 1211 mark_inode_dirty(inode); 1212 ext2_free_branches(inode, &nr, &nr+1, 3); 1213 } 1214 break; 1215 case EXT2_TIND_BLOCK: 1216 ; 1217 } 1218 1219 ext2_discard_reservation(inode); 1220 1221 mutex_unlock(&ei->truncate_mutex); 1222 } 1223 1224 static void ext2_truncate_blocks(struct inode *inode, loff_t offset) 1225 { 1226 if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || 1227 S_ISLNK(inode->i_mode))) 1228 return; 1229 if (ext2_inode_is_fast_symlink(inode)) 1230 return; 1231 1232 filemap_invalidate_lock(inode->i_mapping); 1233 __ext2_truncate_blocks(inode, offset); 1234 filemap_invalidate_unlock(inode->i_mapping); 1235 } 1236 1237 static int ext2_setsize(struct inode *inode, loff_t newsize) 1238 { 1239 int error; 1240 1241 if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || 1242 S_ISLNK(inode->i_mode))) 1243 return -EINVAL; 1244 if (ext2_inode_is_fast_symlink(inode)) 1245 return -EINVAL; 1246 if (IS_APPEND(inode) || IS_IMMUTABLE(inode)) 1247 return -EPERM; 1248 1249 inode_dio_wait(inode); 1250 1251 error = block_truncate_page(inode->i_mapping, newsize, ext2_get_block); 1252 if (error) 1253 return error; 1254 1255 filemap_invalidate_lock(inode->i_mapping); 1256 truncate_setsize(inode, newsize); 1257 __ext2_truncate_blocks(inode, newsize); 1258 filemap_invalidate_unlock(inode->i_mapping); 1259 1260 inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode)); 1261 if (inode_needs_sync(inode)) { 1262 mmb_sync(&EXT2_I(inode)->i_metadata_bhs); 1263 sync_inode_metadata(inode, 1); 1264 } else { 1265 mark_inode_dirty(inode); 1266 } 1267 1268 return 0; 1269 } 1270 1271 static struct ext2_inode *ext2_get_inode(struct super_block *sb, ino_t ino, 1272 struct buffer_head **p) 1273 { 1274 struct buffer_head * bh; 1275 unsigned long block_group; 1276 unsigned long block; 1277 unsigned long offset; 1278 struct ext2_group_desc * gdp; 1279 1280 *p = NULL; 1281 if ((ino != EXT2_ROOT_INO && ino < EXT2_FIRST_INO(sb)) || 1282 ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count)) 1283 goto Einval; 1284 1285 block_group = (ino - 1) / EXT2_INODES_PER_GROUP(sb); 1286 gdp = ext2_get_group_desc(sb, block_group, NULL); 1287 if (!gdp) 1288 goto Egdp; 1289 /* 1290 * Figure out the offset within the block group inode table 1291 */ 1292 offset = ((ino - 1) % EXT2_INODES_PER_GROUP(sb)) * EXT2_INODE_SIZE(sb); 1293 block = le32_to_cpu(gdp->bg_inode_table) + 1294 (offset >> EXT2_BLOCK_SIZE_BITS(sb)); 1295 if (!(bh = sb_bread(sb, block))) 1296 goto Eio; 1297 1298 *p = bh; 1299 offset &= (EXT2_BLOCK_SIZE(sb) - 1); 1300 return (struct ext2_inode *) (bh->b_data + offset); 1301 1302 Einval: 1303 ext2_error(sb, "ext2_get_inode", "bad inode number: %lu", 1304 (unsigned long) ino); 1305 return ERR_PTR(-EINVAL); 1306 Eio: 1307 ext2_error(sb, "ext2_get_inode", 1308 "unable to read inode block - inode=%lu, block=%lu", 1309 (unsigned long) ino, block); 1310 Egdp: 1311 return ERR_PTR(-EIO); 1312 } 1313 1314 void ext2_set_inode_flags(struct inode *inode) 1315 { 1316 unsigned int flags = EXT2_I(inode)->i_flags; 1317 1318 inode->i_flags &= ~(S_SYNC | S_APPEND | S_IMMUTABLE | S_NOATIME | 1319 S_DIRSYNC); 1320 if (flags & EXT2_SYNC_FL) 1321 inode->i_flags |= S_SYNC; 1322 if (flags & EXT2_APPEND_FL) 1323 inode->i_flags |= S_APPEND; 1324 if (flags & EXT2_IMMUTABLE_FL) 1325 inode->i_flags |= S_IMMUTABLE; 1326 if (flags & EXT2_NOATIME_FL) 1327 inode->i_flags |= S_NOATIME; 1328 if (flags & EXT2_DIRSYNC_FL) 1329 inode->i_flags |= S_DIRSYNC; 1330 } 1331 1332 void ext2_set_file_ops(struct inode *inode) 1333 { 1334 inode->i_op = &ext2_file_inode_operations; 1335 inode->i_fop = &ext2_file_operations; 1336 inode->i_mapping->a_ops = &ext2_aops; 1337 } 1338 1339 struct inode *ext2_iget (struct super_block *sb, unsigned long ino) 1340 { 1341 struct ext2_inode_info *ei; 1342 struct buffer_head * bh = NULL; 1343 struct ext2_inode *raw_inode; 1344 struct inode *inode; 1345 long ret = -EIO; 1346 int n; 1347 uid_t i_uid; 1348 gid_t i_gid; 1349 1350 inode = iget_locked(sb, ino); 1351 if (!inode) 1352 return ERR_PTR(-ENOMEM); 1353 if (!(inode_state_read_once(inode) & I_NEW)) 1354 return inode; 1355 1356 ei = EXT2_I(inode); 1357 ei->i_block_alloc_info = NULL; 1358 1359 raw_inode = ext2_get_inode(inode->i_sb, ino, &bh); 1360 if (IS_ERR(raw_inode)) { 1361 ret = PTR_ERR(raw_inode); 1362 goto bad_inode; 1363 } 1364 1365 inode->i_mode = le16_to_cpu(raw_inode->i_mode); 1366 i_uid = (uid_t)le16_to_cpu(raw_inode->i_uid_low); 1367 i_gid = (gid_t)le16_to_cpu(raw_inode->i_gid_low); 1368 if (!(test_opt (inode->i_sb, NO_UID32))) { 1369 i_uid |= le16_to_cpu(raw_inode->i_uid_high) << 16; 1370 i_gid |= le16_to_cpu(raw_inode->i_gid_high) << 16; 1371 } 1372 i_uid_write(inode, i_uid); 1373 i_gid_write(inode, i_gid); 1374 set_nlink(inode, le16_to_cpu(raw_inode->i_links_count)); 1375 inode->i_size = le32_to_cpu(raw_inode->i_size); 1376 inode_set_atime(inode, (signed)le32_to_cpu(raw_inode->i_atime), 0); 1377 inode_set_ctime(inode, (signed)le32_to_cpu(raw_inode->i_ctime), 0); 1378 inode_set_mtime(inode, (signed)le32_to_cpu(raw_inode->i_mtime), 0); 1379 ei->i_dtime = le32_to_cpu(raw_inode->i_dtime); 1380 /* We now have enough fields to check if the inode was active or not. 1381 * This is needed because nfsd might try to access dead inodes 1382 * the test is that same one that e2fsck uses 1383 * NeilBrown 1999oct15 1384 */ 1385 if (inode->i_nlink == 0) { 1386 if (inode->i_mode == 0 || ei->i_dtime) { 1387 /* this inode is deleted */ 1388 ret = -ESTALE; 1389 } else { 1390 ext2_error(sb, __func__, 1391 "inode %lu has zero i_nlink with mode 0%o and no dtime, " 1392 "filesystem may be corrupt", 1393 ino, inode->i_mode); 1394 ret = -EFSCORRUPTED; 1395 } 1396 goto bad_inode; 1397 } 1398 inode->i_blocks = le32_to_cpu(raw_inode->i_blocks); 1399 ei->i_flags = le32_to_cpu(raw_inode->i_flags); 1400 ext2_set_inode_flags(inode); 1401 ei->i_faddr = le32_to_cpu(raw_inode->i_faddr); 1402 ei->i_frag_no = raw_inode->i_frag; 1403 ei->i_frag_size = raw_inode->i_fsize; 1404 ei->i_file_acl = le32_to_cpu(raw_inode->i_file_acl); 1405 ei->i_dir_acl = 0; 1406 1407 if (ei->i_file_acl && 1408 !ext2_data_block_valid(EXT2_SB(sb), ei->i_file_acl, 1)) { 1409 ext2_error(sb, "ext2_iget", "bad extended attribute block %u", 1410 ei->i_file_acl); 1411 ret = -EFSCORRUPTED; 1412 goto bad_inode; 1413 } 1414 1415 if (S_ISREG(inode->i_mode)) 1416 inode->i_size |= ((__u64)le32_to_cpu(raw_inode->i_size_high)) << 32; 1417 else 1418 ei->i_dir_acl = le32_to_cpu(raw_inode->i_dir_acl); 1419 if (i_size_read(inode) < 0) { 1420 ret = -EFSCORRUPTED; 1421 goto bad_inode; 1422 } 1423 ei->i_dtime = 0; 1424 inode->i_generation = le32_to_cpu(raw_inode->i_generation); 1425 ei->i_state = 0; 1426 ei->i_block_group = (ino - 1) / EXT2_INODES_PER_GROUP(inode->i_sb); 1427 ei->i_dir_start_lookup = 0; 1428 1429 /* 1430 * NOTE! The in-memory inode i_data array is in little-endian order 1431 * even on big-endian machines: we do NOT byteswap the block numbers! 1432 */ 1433 for (n = 0; n < EXT2_N_BLOCKS; n++) 1434 ei->i_data[n] = raw_inode->i_block[n]; 1435 1436 if (S_ISREG(inode->i_mode)) { 1437 ext2_set_file_ops(inode); 1438 } else if (S_ISDIR(inode->i_mode)) { 1439 inode->i_op = &ext2_dir_inode_operations; 1440 inode->i_fop = &ext2_dir_operations; 1441 inode->i_mapping->a_ops = &ext2_aops; 1442 } else if (S_ISLNK(inode->i_mode)) { 1443 if (ext2_inode_is_fast_symlink(inode)) { 1444 inode->i_link = (char *)ei->i_data; 1445 inode->i_op = &ext2_fast_symlink_inode_operations; 1446 nd_terminate_link(ei->i_data, inode->i_size, 1447 sizeof(ei->i_data) - 1); 1448 } else { 1449 inode->i_op = &ext2_symlink_inode_operations; 1450 inode_nohighmem(inode); 1451 inode->i_mapping->a_ops = &ext2_aops; 1452 } 1453 } else { 1454 inode->i_op = &ext2_special_inode_operations; 1455 if (raw_inode->i_block[0]) 1456 init_special_inode(inode, inode->i_mode, 1457 old_decode_dev(le32_to_cpu(raw_inode->i_block[0]))); 1458 else 1459 init_special_inode(inode, inode->i_mode, 1460 new_decode_dev(le32_to_cpu(raw_inode->i_block[1]))); 1461 } 1462 brelse (bh); 1463 unlock_new_inode(inode); 1464 return inode; 1465 1466 bad_inode: 1467 brelse(bh); 1468 iget_failed(inode); 1469 return ERR_PTR(ret); 1470 } 1471 1472 static int __ext2_write_inode(struct inode *inode, int do_sync) 1473 { 1474 struct ext2_inode_info *ei = EXT2_I(inode); 1475 struct super_block *sb = inode->i_sb; 1476 ino_t ino = inode->i_ino; 1477 uid_t uid = i_uid_read(inode); 1478 gid_t gid = i_gid_read(inode); 1479 struct buffer_head * bh; 1480 struct ext2_inode * raw_inode = ext2_get_inode(sb, ino, &bh); 1481 int n; 1482 int err = 0; 1483 1484 if (IS_ERR(raw_inode)) 1485 return -EIO; 1486 1487 /* For fields not tracking in the in-memory inode, 1488 * initialise them to zero for new inodes. */ 1489 if (ei->i_state & EXT2_STATE_NEW) 1490 memset(raw_inode, 0, EXT2_SB(sb)->s_inode_size); 1491 1492 raw_inode->i_mode = cpu_to_le16(inode->i_mode); 1493 if (!(test_opt(sb, NO_UID32))) { 1494 raw_inode->i_uid_low = cpu_to_le16(low_16_bits(uid)); 1495 raw_inode->i_gid_low = cpu_to_le16(low_16_bits(gid)); 1496 /* 1497 * Fix up interoperability with old kernels. Otherwise, old inodes get 1498 * re-used with the upper 16 bits of the uid/gid intact 1499 */ 1500 if (!ei->i_dtime) { 1501 raw_inode->i_uid_high = cpu_to_le16(high_16_bits(uid)); 1502 raw_inode->i_gid_high = cpu_to_le16(high_16_bits(gid)); 1503 } else { 1504 raw_inode->i_uid_high = 0; 1505 raw_inode->i_gid_high = 0; 1506 } 1507 } else { 1508 raw_inode->i_uid_low = cpu_to_le16(fs_high2lowuid(uid)); 1509 raw_inode->i_gid_low = cpu_to_le16(fs_high2lowgid(gid)); 1510 raw_inode->i_uid_high = 0; 1511 raw_inode->i_gid_high = 0; 1512 } 1513 raw_inode->i_links_count = cpu_to_le16(inode->i_nlink); 1514 raw_inode->i_size = cpu_to_le32(inode->i_size); 1515 raw_inode->i_atime = cpu_to_le32(inode_get_atime_sec(inode)); 1516 raw_inode->i_ctime = cpu_to_le32(inode_get_ctime_sec(inode)); 1517 raw_inode->i_mtime = cpu_to_le32(inode_get_mtime_sec(inode)); 1518 1519 raw_inode->i_blocks = cpu_to_le32(inode->i_blocks); 1520 raw_inode->i_dtime = cpu_to_le32(ei->i_dtime); 1521 raw_inode->i_flags = cpu_to_le32(ei->i_flags); 1522 raw_inode->i_faddr = cpu_to_le32(ei->i_faddr); 1523 raw_inode->i_frag = ei->i_frag_no; 1524 raw_inode->i_fsize = ei->i_frag_size; 1525 raw_inode->i_file_acl = cpu_to_le32(ei->i_file_acl); 1526 if (!S_ISREG(inode->i_mode)) 1527 raw_inode->i_dir_acl = cpu_to_le32(ei->i_dir_acl); 1528 else { 1529 raw_inode->i_size_high = cpu_to_le32(inode->i_size >> 32); 1530 if (inode->i_size > 0x7fffffffULL) { 1531 if (!EXT2_HAS_RO_COMPAT_FEATURE(sb, 1532 EXT2_FEATURE_RO_COMPAT_LARGE_FILE) || 1533 EXT2_SB(sb)->s_es->s_rev_level == 1534 cpu_to_le32(EXT2_GOOD_OLD_REV)) { 1535 /* If this is the first large file 1536 * created, add a flag to the superblock. 1537 */ 1538 spin_lock(&EXT2_SB(sb)->s_lock); 1539 ext2_update_dynamic_rev(sb); 1540 EXT2_SET_RO_COMPAT_FEATURE(sb, 1541 EXT2_FEATURE_RO_COMPAT_LARGE_FILE); 1542 spin_unlock(&EXT2_SB(sb)->s_lock); 1543 ext2_sync_super(sb, EXT2_SB(sb)->s_es, 1); 1544 } 1545 } 1546 } 1547 1548 raw_inode->i_generation = cpu_to_le32(inode->i_generation); 1549 if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) { 1550 if (old_valid_dev(inode->i_rdev)) { 1551 raw_inode->i_block[0] = 1552 cpu_to_le32(old_encode_dev(inode->i_rdev)); 1553 raw_inode->i_block[1] = 0; 1554 } else { 1555 raw_inode->i_block[0] = 0; 1556 raw_inode->i_block[1] = 1557 cpu_to_le32(new_encode_dev(inode->i_rdev)); 1558 raw_inode->i_block[2] = 0; 1559 } 1560 } else for (n = 0; n < EXT2_N_BLOCKS; n++) 1561 raw_inode->i_block[n] = ei->i_data[n]; 1562 mark_buffer_dirty(bh); 1563 if (do_sync) { 1564 sync_dirty_buffer(bh); 1565 if (buffer_req(bh) && !buffer_uptodate(bh)) { 1566 printk ("IO error syncing ext2 inode [%s:%08lx]\n", 1567 sb->s_id, (unsigned long) ino); 1568 err = -EIO; 1569 } 1570 } 1571 ei->i_state &= ~EXT2_STATE_NEW; 1572 brelse (bh); 1573 return err; 1574 } 1575 1576 int ext2_write_inode(struct inode *inode, struct writeback_control *wbc) 1577 { 1578 return __ext2_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL); 1579 } 1580 1581 int ext2_getattr(struct mnt_idmap *idmap, const struct path *path, 1582 struct kstat *stat, u32 request_mask, unsigned int query_flags) 1583 { 1584 struct inode *inode = d_inode(path->dentry); 1585 struct ext2_inode_info *ei = EXT2_I(inode); 1586 unsigned int flags; 1587 1588 flags = ei->i_flags & EXT2_FL_USER_VISIBLE; 1589 if (flags & EXT2_APPEND_FL) 1590 stat->attributes |= STATX_ATTR_APPEND; 1591 if (flags & EXT2_COMPR_FL) 1592 stat->attributes |= STATX_ATTR_COMPRESSED; 1593 if (flags & EXT2_IMMUTABLE_FL) 1594 stat->attributes |= STATX_ATTR_IMMUTABLE; 1595 if (flags & EXT2_NODUMP_FL) 1596 stat->attributes |= STATX_ATTR_NODUMP; 1597 stat->attributes_mask |= (STATX_ATTR_APPEND | 1598 STATX_ATTR_COMPRESSED | 1599 STATX_ATTR_ENCRYPTED | 1600 STATX_ATTR_IMMUTABLE | 1601 STATX_ATTR_NODUMP); 1602 1603 generic_fillattr(&nop_mnt_idmap, request_mask, inode, stat); 1604 return 0; 1605 } 1606 1607 int ext2_setattr(struct mnt_idmap *idmap, struct dentry *dentry, 1608 struct iattr *iattr) 1609 { 1610 struct inode *inode = d_inode(dentry); 1611 int error; 1612 1613 error = setattr_prepare(&nop_mnt_idmap, dentry, iattr); 1614 if (error) 1615 return error; 1616 1617 if (is_quota_modification(&nop_mnt_idmap, inode, iattr)) { 1618 error = dquot_initialize(inode); 1619 if (error) 1620 return error; 1621 } 1622 if (i_uid_needs_update(&nop_mnt_idmap, iattr, inode) || 1623 i_gid_needs_update(&nop_mnt_idmap, iattr, inode)) { 1624 error = dquot_transfer(&nop_mnt_idmap, inode, iattr); 1625 if (error) 1626 return error; 1627 } 1628 if (iattr->ia_valid & ATTR_SIZE && iattr->ia_size != inode->i_size) { 1629 error = ext2_setsize(inode, iattr->ia_size); 1630 if (error) 1631 return error; 1632 } 1633 setattr_copy(&nop_mnt_idmap, inode, iattr); 1634 if (iattr->ia_valid & ATTR_MODE) 1635 error = posix_acl_chmod(&nop_mnt_idmap, dentry, inode->i_mode); 1636 mark_inode_dirty(inode); 1637 1638 return error; 1639 } 1640