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/dax.h> 30 #include <linux/blkdev.h> 31 #include <linux/quotaops.h> 32 #include <linux/writeback.h> 33 #include <linux/buffer_head.h> 34 #include <linux/mpage.h> 35 #include <linux/fiemap.h> 36 #include <linux/iomap.h> 37 #include <linux/namei.h> 38 #include <linux/uio.h> 39 #include "ext2.h" 40 #include "acl.h" 41 #include "xattr.h" 42 43 static int __ext2_write_inode(struct inode *inode, int do_sync); 44 45 /* 46 * Test whether an inode is a fast symlink. 47 */ 48 static inline int ext2_inode_is_fast_symlink(struct inode *inode) 49 { 50 int ea_blocks = EXT2_I(inode)->i_file_acl ? 51 (inode->i_sb->s_blocksize >> 9) : 0; 52 53 return (S_ISLNK(inode->i_mode) && 54 inode->i_blocks - ea_blocks == 0); 55 } 56 57 static void ext2_truncate_blocks(struct inode *inode, loff_t offset); 58 59 void ext2_write_failed(struct address_space *mapping, loff_t to) 60 { 61 struct inode *inode = mapping->host; 62 63 if (to > inode->i_size) { 64 truncate_pagecache(inode, inode->i_size); 65 ext2_truncate_blocks(inode, inode->i_size); 66 } 67 } 68 69 /* 70 * Called at the last iput() if i_nlink is zero. 71 */ 72 void ext2_evict_inode(struct inode * inode) 73 { 74 struct ext2_block_alloc_info *rsv; 75 int want_delete = 0; 76 77 if (!inode->i_nlink && !is_bad_inode(inode)) { 78 want_delete = 1; 79 dquot_initialize(inode); 80 } else { 81 dquot_drop(inode); 82 } 83 84 truncate_inode_pages_final(&inode->i_data); 85 86 if (want_delete) { 87 sb_start_intwrite(inode->i_sb); 88 /* set dtime */ 89 EXT2_I(inode)->i_dtime = ktime_get_real_seconds(); 90 mark_inode_dirty(inode); 91 __ext2_write_inode(inode, inode_needs_sync(inode)); 92 /* truncate to 0 */ 93 inode->i_size = 0; 94 if (inode->i_blocks) 95 ext2_truncate_blocks(inode, 0); 96 ext2_xattr_delete_inode(inode); 97 } 98 99 invalidate_inode_buffers(inode); 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 mark_buffer_dirty_inode(bh, inode); 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 mark_buffer_dirty_inode(where->bh, inode); 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 BUG_ON(maxblocks == 0); 642 643 depth = ext2_block_to_path(inode,iblock,offsets,&blocks_to_boundary); 644 645 if (depth == 0) 646 return -EIO; 647 648 partial = ext2_get_branch(inode, depth, offsets, chain, &err); 649 /* Simplest case - block found, no allocation needed */ 650 if (!partial) { 651 first_block = le32_to_cpu(chain[depth - 1].key); 652 count++; 653 /*map more blocks*/ 654 while (count < maxblocks && count <= blocks_to_boundary) { 655 ext2_fsblk_t blk; 656 657 if (!verify_chain(chain, chain + depth - 1)) { 658 /* 659 * Indirect block might be removed by 660 * truncate while we were reading it. 661 * Handling of that case: forget what we've 662 * got now, go to reread. 663 */ 664 err = -EAGAIN; 665 count = 0; 666 partial = chain + depth - 1; 667 break; 668 } 669 blk = le32_to_cpu(*(chain[depth-1].p + count)); 670 if (blk == first_block + count) 671 count++; 672 else 673 break; 674 } 675 if (err != -EAGAIN) 676 goto got_it; 677 } 678 679 /* Next simple case - plain lookup or failed read of indirect block */ 680 if (!create || err == -EIO) 681 goto cleanup; 682 683 mutex_lock(&ei->truncate_mutex); 684 /* 685 * If the indirect block is missing while we are reading 686 * the chain(ext2_get_branch() returns -EAGAIN err), or 687 * if the chain has been changed after we grab the semaphore, 688 * (either because another process truncated this branch, or 689 * another get_block allocated this branch) re-grab the chain to see if 690 * the request block has been allocated or not. 691 * 692 * Since we already block the truncate/other get_block 693 * at this point, we will have the current copy of the chain when we 694 * splice the branch into the tree. 695 */ 696 if (err == -EAGAIN || !verify_chain(chain, partial)) { 697 while (partial > chain) { 698 brelse(partial->bh); 699 partial--; 700 } 701 partial = ext2_get_branch(inode, depth, offsets, chain, &err); 702 if (!partial) { 703 count++; 704 mutex_unlock(&ei->truncate_mutex); 705 goto got_it; 706 } 707 708 if (err) { 709 mutex_unlock(&ei->truncate_mutex); 710 goto cleanup; 711 } 712 } 713 714 /* 715 * Okay, we need to do block allocation. Lazily initialize the block 716 * allocation info here if necessary 717 */ 718 if (S_ISREG(inode->i_mode) && (!ei->i_block_alloc_info)) 719 ext2_init_block_alloc_info(inode); 720 721 goal = ext2_find_goal(inode, iblock, partial); 722 723 /* the number of blocks need to allocate for [d,t]indirect blocks */ 724 indirect_blks = (chain + depth) - partial - 1; 725 /* 726 * Next look up the indirect map to count the total number of 727 * direct blocks to allocate for this branch. 728 */ 729 count = ext2_blks_to_allocate(partial, indirect_blks, 730 maxblocks, blocks_to_boundary); 731 /* 732 * XXX ???? Block out ext2_truncate while we alter the tree 733 */ 734 err = ext2_alloc_branch(inode, indirect_blks, &count, goal, 735 offsets + (partial - chain), partial); 736 737 if (err) { 738 mutex_unlock(&ei->truncate_mutex); 739 goto cleanup; 740 } 741 742 if (IS_DAX(inode)) { 743 /* 744 * We must unmap blocks before zeroing so that writeback cannot 745 * overwrite zeros with stale data from block device page cache. 746 */ 747 clean_bdev_aliases(inode->i_sb->s_bdev, 748 le32_to_cpu(chain[depth-1].key), 749 count); 750 /* 751 * block must be initialised before we put it in the tree 752 * so that it's not found by another thread before it's 753 * initialised 754 */ 755 err = sb_issue_zeroout(inode->i_sb, 756 le32_to_cpu(chain[depth-1].key), count, 757 GFP_KERNEL); 758 if (err) { 759 mutex_unlock(&ei->truncate_mutex); 760 goto cleanup; 761 } 762 } 763 *new = true; 764 765 ext2_splice_branch(inode, iblock, partial, indirect_blks, count); 766 mutex_unlock(&ei->truncate_mutex); 767 got_it: 768 if (count > blocks_to_boundary) 769 *boundary = true; 770 err = count; 771 /* Clean up and exit */ 772 partial = chain + depth - 1; /* the whole chain */ 773 cleanup: 774 while (partial > chain) { 775 brelse(partial->bh); 776 partial--; 777 } 778 if (err > 0) 779 *bno = le32_to_cpu(chain[depth-1].key); 780 return err; 781 } 782 783 int ext2_get_block(struct inode *inode, sector_t iblock, 784 struct buffer_head *bh_result, int create) 785 { 786 unsigned max_blocks = bh_result->b_size >> inode->i_blkbits; 787 bool new = false, boundary = false; 788 u32 bno; 789 int ret; 790 791 ret = ext2_get_blocks(inode, iblock, max_blocks, &bno, &new, &boundary, 792 create); 793 if (ret <= 0) 794 return ret; 795 796 map_bh(bh_result, inode->i_sb, bno); 797 bh_result->b_size = (ret << inode->i_blkbits); 798 if (new) 799 set_buffer_new(bh_result); 800 if (boundary) 801 set_buffer_boundary(bh_result); 802 return 0; 803 804 } 805 806 static int ext2_iomap_begin(struct inode *inode, loff_t offset, loff_t length, 807 unsigned flags, struct iomap *iomap, struct iomap *srcmap) 808 { 809 unsigned int blkbits = inode->i_blkbits; 810 unsigned long first_block = offset >> blkbits; 811 unsigned long max_blocks = (length + (1 << blkbits) - 1) >> blkbits; 812 struct ext2_sb_info *sbi = EXT2_SB(inode->i_sb); 813 bool new = false, boundary = false; 814 u32 bno; 815 int ret; 816 bool create = flags & IOMAP_WRITE; 817 818 /* 819 * For writes that could fill holes inside i_size on a 820 * DIO_SKIP_HOLES filesystem we forbid block creations: only 821 * overwrites are permitted. 822 */ 823 if ((flags & IOMAP_DIRECT) && 824 (first_block << blkbits) < i_size_read(inode)) 825 create = 0; 826 827 /* 828 * Writes that span EOF might trigger an IO size update on completion, 829 * so consider them to be dirty for the purposes of O_DSYNC even if 830 * there is no other metadata changes pending or have been made here. 831 */ 832 if ((flags & IOMAP_WRITE) && offset + length > i_size_read(inode)) 833 iomap->flags |= IOMAP_F_DIRTY; 834 835 ret = ext2_get_blocks(inode, first_block, max_blocks, 836 &bno, &new, &boundary, create); 837 if (ret < 0) 838 return ret; 839 840 iomap->flags = 0; 841 iomap->offset = (u64)first_block << blkbits; 842 if (flags & IOMAP_DAX) 843 iomap->dax_dev = sbi->s_daxdev; 844 else 845 iomap->bdev = inode->i_sb->s_bdev; 846 847 if (ret == 0) { 848 /* 849 * Switch to buffered-io for writing to holes in a non-extent 850 * based filesystem to avoid stale data exposure problem. 851 */ 852 if (!create && (flags & IOMAP_WRITE) && (flags & IOMAP_DIRECT)) 853 return -ENOTBLK; 854 iomap->type = IOMAP_HOLE; 855 iomap->addr = IOMAP_NULL_ADDR; 856 iomap->length = 1 << blkbits; 857 } else { 858 iomap->type = IOMAP_MAPPED; 859 iomap->addr = (u64)bno << blkbits; 860 if (flags & IOMAP_DAX) 861 iomap->addr += sbi->s_dax_part_off; 862 iomap->length = (u64)ret << blkbits; 863 iomap->flags |= IOMAP_F_MERGED; 864 } 865 866 if (new) 867 iomap->flags |= IOMAP_F_NEW; 868 return 0; 869 } 870 871 static int 872 ext2_iomap_end(struct inode *inode, loff_t offset, loff_t length, 873 ssize_t written, unsigned flags, struct iomap *iomap) 874 { 875 /* 876 * Switch to buffered-io in case of any error. 877 * Blocks allocated can be used by the buffered-io path. 878 */ 879 if ((flags & IOMAP_DIRECT) && (flags & IOMAP_WRITE) && written == 0) 880 return -ENOTBLK; 881 882 if (iomap->type == IOMAP_MAPPED && 883 written < length && 884 (flags & IOMAP_WRITE)) 885 ext2_write_failed(inode->i_mapping, offset + length); 886 return 0; 887 } 888 889 const struct iomap_ops ext2_iomap_ops = { 890 .iomap_begin = ext2_iomap_begin, 891 .iomap_end = ext2_iomap_end, 892 }; 893 894 int ext2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, 895 u64 start, u64 len) 896 { 897 int ret; 898 899 inode_lock(inode); 900 len = min_t(u64, len, i_size_read(inode)); 901 ret = iomap_fiemap(inode, fieinfo, start, len, &ext2_iomap_ops); 902 inode_unlock(inode); 903 904 return ret; 905 } 906 907 static int ext2_read_folio(struct file *file, struct folio *folio) 908 { 909 return mpage_read_folio(folio, ext2_get_block); 910 } 911 912 static void ext2_readahead(struct readahead_control *rac) 913 { 914 mpage_readahead(rac, ext2_get_block); 915 } 916 917 static int 918 ext2_write_begin(struct file *file, struct address_space *mapping, 919 loff_t pos, unsigned len, struct page **pagep, void **fsdata) 920 { 921 int ret; 922 923 ret = block_write_begin(mapping, pos, len, pagep, ext2_get_block); 924 if (ret < 0) 925 ext2_write_failed(mapping, pos + len); 926 return ret; 927 } 928 929 static int ext2_write_end(struct file *file, struct address_space *mapping, 930 loff_t pos, unsigned len, unsigned copied, 931 struct page *page, void *fsdata) 932 { 933 int ret; 934 935 ret = generic_write_end(file, mapping, pos, len, copied, page, fsdata); 936 if (ret < len) 937 ext2_write_failed(mapping, pos + len); 938 return ret; 939 } 940 941 static sector_t ext2_bmap(struct address_space *mapping, sector_t block) 942 { 943 return generic_block_bmap(mapping,block,ext2_get_block); 944 } 945 946 static int 947 ext2_writepages(struct address_space *mapping, struct writeback_control *wbc) 948 { 949 return mpage_writepages(mapping, wbc, ext2_get_block); 950 } 951 952 static int 953 ext2_dax_writepages(struct address_space *mapping, struct writeback_control *wbc) 954 { 955 struct ext2_sb_info *sbi = EXT2_SB(mapping->host->i_sb); 956 957 return dax_writeback_mapping_range(mapping, sbi->s_daxdev, wbc); 958 } 959 960 const struct address_space_operations ext2_aops = { 961 .dirty_folio = block_dirty_folio, 962 .invalidate_folio = block_invalidate_folio, 963 .read_folio = ext2_read_folio, 964 .readahead = ext2_readahead, 965 .write_begin = ext2_write_begin, 966 .write_end = ext2_write_end, 967 .bmap = ext2_bmap, 968 .writepages = ext2_writepages, 969 .migrate_folio = buffer_migrate_folio, 970 .is_partially_uptodate = block_is_partially_uptodate, 971 .error_remove_folio = generic_error_remove_folio, 972 }; 973 974 static const struct address_space_operations ext2_dax_aops = { 975 .writepages = ext2_dax_writepages, 976 .dirty_folio = noop_dirty_folio, 977 }; 978 979 /* 980 * Probably it should be a library function... search for first non-zero word 981 * or memcmp with zero_page, whatever is better for particular architecture. 982 * Linus? 983 */ 984 static inline int all_zeroes(__le32 *p, __le32 *q) 985 { 986 while (p < q) 987 if (*p++) 988 return 0; 989 return 1; 990 } 991 992 /** 993 * ext2_find_shared - find the indirect blocks for partial truncation. 994 * @inode: inode in question 995 * @depth: depth of the affected branch 996 * @offsets: offsets of pointers in that branch (see ext2_block_to_path) 997 * @chain: place to store the pointers to partial indirect blocks 998 * @top: place to the (detached) top of branch 999 * 1000 * This is a helper function used by ext2_truncate(). 1001 * 1002 * When we do truncate() we may have to clean the ends of several indirect 1003 * blocks but leave the blocks themselves alive. Block is partially 1004 * truncated if some data below the new i_size is referred from it (and 1005 * it is on the path to the first completely truncated data block, indeed). 1006 * We have to free the top of that path along with everything to the right 1007 * of the path. Since no allocation past the truncation point is possible 1008 * until ext2_truncate() finishes, we may safely do the latter, but top 1009 * of branch may require special attention - pageout below the truncation 1010 * point might try to populate it. 1011 * 1012 * We atomically detach the top of branch from the tree, store the block 1013 * number of its root in *@top, pointers to buffer_heads of partially 1014 * truncated blocks - in @chain[].bh and pointers to their last elements 1015 * that should not be removed - in @chain[].p. Return value is the pointer 1016 * to last filled element of @chain. 1017 * 1018 * The work left to caller to do the actual freeing of subtrees: 1019 * a) free the subtree starting from *@top 1020 * b) free the subtrees whose roots are stored in 1021 * (@chain[i].p+1 .. end of @chain[i].bh->b_data) 1022 * c) free the subtrees growing from the inode past the @chain[0].p 1023 * (no partially truncated stuff there). 1024 */ 1025 1026 static Indirect *ext2_find_shared(struct inode *inode, 1027 int depth, 1028 int offsets[4], 1029 Indirect chain[4], 1030 __le32 *top) 1031 { 1032 Indirect *partial, *p; 1033 int k, err; 1034 1035 *top = 0; 1036 for (k = depth; k > 1 && !offsets[k-1]; k--) 1037 ; 1038 partial = ext2_get_branch(inode, k, offsets, chain, &err); 1039 if (!partial) 1040 partial = chain + k-1; 1041 /* 1042 * If the branch acquired continuation since we've looked at it - 1043 * fine, it should all survive and (new) top doesn't belong to us. 1044 */ 1045 write_lock(&EXT2_I(inode)->i_meta_lock); 1046 if (!partial->key && *partial->p) { 1047 write_unlock(&EXT2_I(inode)->i_meta_lock); 1048 goto no_top; 1049 } 1050 for (p=partial; p>chain && all_zeroes((__le32*)p->bh->b_data,p->p); p--) 1051 ; 1052 /* 1053 * OK, we've found the last block that must survive. The rest of our 1054 * branch should be detached before unlocking. However, if that rest 1055 * of branch is all ours and does not grow immediately from the inode 1056 * it's easier to cheat and just decrement partial->p. 1057 */ 1058 if (p == chain + k - 1 && p > chain) { 1059 p->p--; 1060 } else { 1061 *top = *p->p; 1062 *p->p = 0; 1063 } 1064 write_unlock(&EXT2_I(inode)->i_meta_lock); 1065 1066 while(partial > p) 1067 { 1068 brelse(partial->bh); 1069 partial--; 1070 } 1071 no_top: 1072 return partial; 1073 } 1074 1075 /** 1076 * ext2_free_data - free a list of data blocks 1077 * @inode: inode we are dealing with 1078 * @p: array of block numbers 1079 * @q: points immediately past the end of array 1080 * 1081 * We are freeing all blocks referred from that array (numbers are 1082 * stored as little-endian 32-bit) and updating @inode->i_blocks 1083 * appropriately. 1084 */ 1085 static inline void ext2_free_data(struct inode *inode, __le32 *p, __le32 *q) 1086 { 1087 ext2_fsblk_t block_to_free = 0, count = 0; 1088 ext2_fsblk_t nr; 1089 1090 for ( ; p < q ; p++) { 1091 nr = le32_to_cpu(*p); 1092 if (nr) { 1093 *p = 0; 1094 /* accumulate blocks to free if they're contiguous */ 1095 if (count == 0) 1096 goto free_this; 1097 else if (block_to_free == nr - count) 1098 count++; 1099 else { 1100 ext2_free_blocks (inode, block_to_free, count); 1101 mark_inode_dirty(inode); 1102 free_this: 1103 block_to_free = nr; 1104 count = 1; 1105 } 1106 } 1107 } 1108 if (count > 0) { 1109 ext2_free_blocks (inode, block_to_free, count); 1110 mark_inode_dirty(inode); 1111 } 1112 } 1113 1114 /** 1115 * ext2_free_branches - free an array of branches 1116 * @inode: inode we are dealing with 1117 * @p: array of block numbers 1118 * @q: pointer immediately past the end of array 1119 * @depth: depth of the branches to free 1120 * 1121 * We are freeing all blocks referred from these branches (numbers are 1122 * stored as little-endian 32-bit) and updating @inode->i_blocks 1123 * appropriately. 1124 */ 1125 static void ext2_free_branches(struct inode *inode, __le32 *p, __le32 *q, int depth) 1126 { 1127 struct buffer_head * bh; 1128 ext2_fsblk_t nr; 1129 1130 if (depth--) { 1131 int addr_per_block = EXT2_ADDR_PER_BLOCK(inode->i_sb); 1132 for ( ; p < q ; p++) { 1133 nr = le32_to_cpu(*p); 1134 if (!nr) 1135 continue; 1136 *p = 0; 1137 bh = sb_bread(inode->i_sb, nr); 1138 /* 1139 * A read failure? Report error and clear slot 1140 * (should be rare). 1141 */ 1142 if (!bh) { 1143 ext2_error(inode->i_sb, "ext2_free_branches", 1144 "Read failure, inode=%ld, block=%ld", 1145 inode->i_ino, nr); 1146 continue; 1147 } 1148 ext2_free_branches(inode, 1149 (__le32*)bh->b_data, 1150 (__le32*)bh->b_data + addr_per_block, 1151 depth); 1152 bforget(bh); 1153 ext2_free_blocks(inode, nr, 1); 1154 mark_inode_dirty(inode); 1155 } 1156 } else 1157 ext2_free_data(inode, p, q); 1158 } 1159 1160 /* mapping->invalidate_lock must be held when calling this function */ 1161 static void __ext2_truncate_blocks(struct inode *inode, loff_t offset) 1162 { 1163 __le32 *i_data = EXT2_I(inode)->i_data; 1164 struct ext2_inode_info *ei = EXT2_I(inode); 1165 int addr_per_block = EXT2_ADDR_PER_BLOCK(inode->i_sb); 1166 int offsets[4]; 1167 Indirect chain[4]; 1168 Indirect *partial; 1169 __le32 nr = 0; 1170 int n; 1171 long iblock; 1172 unsigned blocksize; 1173 blocksize = inode->i_sb->s_blocksize; 1174 iblock = (offset + blocksize-1) >> EXT2_BLOCK_SIZE_BITS(inode->i_sb); 1175 1176 #ifdef CONFIG_FS_DAX 1177 WARN_ON(!rwsem_is_locked(&inode->i_mapping->invalidate_lock)); 1178 #endif 1179 1180 n = ext2_block_to_path(inode, iblock, offsets, NULL); 1181 if (n == 0) 1182 return; 1183 1184 /* 1185 * From here we block out all ext2_get_block() callers who want to 1186 * modify the block allocation tree. 1187 */ 1188 mutex_lock(&ei->truncate_mutex); 1189 1190 if (n == 1) { 1191 ext2_free_data(inode, i_data+offsets[0], 1192 i_data + EXT2_NDIR_BLOCKS); 1193 goto do_indirects; 1194 } 1195 1196 partial = ext2_find_shared(inode, n, offsets, chain, &nr); 1197 /* Kill the top of shared branch (already detached) */ 1198 if (nr) { 1199 if (partial == chain) 1200 mark_inode_dirty(inode); 1201 else 1202 mark_buffer_dirty_inode(partial->bh, inode); 1203 ext2_free_branches(inode, &nr, &nr+1, (chain+n-1) - partial); 1204 } 1205 /* Clear the ends of indirect blocks on the shared branch */ 1206 while (partial > chain) { 1207 ext2_free_branches(inode, 1208 partial->p + 1, 1209 (__le32*)partial->bh->b_data+addr_per_block, 1210 (chain+n-1) - partial); 1211 mark_buffer_dirty_inode(partial->bh, inode); 1212 brelse (partial->bh); 1213 partial--; 1214 } 1215 do_indirects: 1216 /* Kill the remaining (whole) subtrees */ 1217 switch (offsets[0]) { 1218 default: 1219 nr = i_data[EXT2_IND_BLOCK]; 1220 if (nr) { 1221 i_data[EXT2_IND_BLOCK] = 0; 1222 mark_inode_dirty(inode); 1223 ext2_free_branches(inode, &nr, &nr+1, 1); 1224 } 1225 fallthrough; 1226 case EXT2_IND_BLOCK: 1227 nr = i_data[EXT2_DIND_BLOCK]; 1228 if (nr) { 1229 i_data[EXT2_DIND_BLOCK] = 0; 1230 mark_inode_dirty(inode); 1231 ext2_free_branches(inode, &nr, &nr+1, 2); 1232 } 1233 fallthrough; 1234 case EXT2_DIND_BLOCK: 1235 nr = i_data[EXT2_TIND_BLOCK]; 1236 if (nr) { 1237 i_data[EXT2_TIND_BLOCK] = 0; 1238 mark_inode_dirty(inode); 1239 ext2_free_branches(inode, &nr, &nr+1, 3); 1240 } 1241 break; 1242 case EXT2_TIND_BLOCK: 1243 ; 1244 } 1245 1246 ext2_discard_reservation(inode); 1247 1248 mutex_unlock(&ei->truncate_mutex); 1249 } 1250 1251 static void ext2_truncate_blocks(struct inode *inode, loff_t offset) 1252 { 1253 if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || 1254 S_ISLNK(inode->i_mode))) 1255 return; 1256 if (ext2_inode_is_fast_symlink(inode)) 1257 return; 1258 1259 filemap_invalidate_lock(inode->i_mapping); 1260 __ext2_truncate_blocks(inode, offset); 1261 filemap_invalidate_unlock(inode->i_mapping); 1262 } 1263 1264 static int ext2_setsize(struct inode *inode, loff_t newsize) 1265 { 1266 int error; 1267 1268 if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || 1269 S_ISLNK(inode->i_mode))) 1270 return -EINVAL; 1271 if (ext2_inode_is_fast_symlink(inode)) 1272 return -EINVAL; 1273 if (IS_APPEND(inode) || IS_IMMUTABLE(inode)) 1274 return -EPERM; 1275 1276 inode_dio_wait(inode); 1277 1278 if (IS_DAX(inode)) 1279 error = dax_truncate_page(inode, newsize, NULL, 1280 &ext2_iomap_ops); 1281 else 1282 error = block_truncate_page(inode->i_mapping, 1283 newsize, ext2_get_block); 1284 if (error) 1285 return error; 1286 1287 filemap_invalidate_lock(inode->i_mapping); 1288 truncate_setsize(inode, newsize); 1289 __ext2_truncate_blocks(inode, newsize); 1290 filemap_invalidate_unlock(inode->i_mapping); 1291 1292 inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode)); 1293 if (inode_needs_sync(inode)) { 1294 sync_mapping_buffers(inode->i_mapping); 1295 sync_inode_metadata(inode, 1); 1296 } else { 1297 mark_inode_dirty(inode); 1298 } 1299 1300 return 0; 1301 } 1302 1303 static struct ext2_inode *ext2_get_inode(struct super_block *sb, ino_t ino, 1304 struct buffer_head **p) 1305 { 1306 struct buffer_head * bh; 1307 unsigned long block_group; 1308 unsigned long block; 1309 unsigned long offset; 1310 struct ext2_group_desc * gdp; 1311 1312 *p = NULL; 1313 if ((ino != EXT2_ROOT_INO && ino < EXT2_FIRST_INO(sb)) || 1314 ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count)) 1315 goto Einval; 1316 1317 block_group = (ino - 1) / EXT2_INODES_PER_GROUP(sb); 1318 gdp = ext2_get_group_desc(sb, block_group, NULL); 1319 if (!gdp) 1320 goto Egdp; 1321 /* 1322 * Figure out the offset within the block group inode table 1323 */ 1324 offset = ((ino - 1) % EXT2_INODES_PER_GROUP(sb)) * EXT2_INODE_SIZE(sb); 1325 block = le32_to_cpu(gdp->bg_inode_table) + 1326 (offset >> EXT2_BLOCK_SIZE_BITS(sb)); 1327 if (!(bh = sb_bread(sb, block))) 1328 goto Eio; 1329 1330 *p = bh; 1331 offset &= (EXT2_BLOCK_SIZE(sb) - 1); 1332 return (struct ext2_inode *) (bh->b_data + offset); 1333 1334 Einval: 1335 ext2_error(sb, "ext2_get_inode", "bad inode number: %lu", 1336 (unsigned long) ino); 1337 return ERR_PTR(-EINVAL); 1338 Eio: 1339 ext2_error(sb, "ext2_get_inode", 1340 "unable to read inode block - inode=%lu, block=%lu", 1341 (unsigned long) ino, block); 1342 Egdp: 1343 return ERR_PTR(-EIO); 1344 } 1345 1346 void ext2_set_inode_flags(struct inode *inode) 1347 { 1348 unsigned int flags = EXT2_I(inode)->i_flags; 1349 1350 inode->i_flags &= ~(S_SYNC | S_APPEND | S_IMMUTABLE | S_NOATIME | 1351 S_DIRSYNC | S_DAX); 1352 if (flags & EXT2_SYNC_FL) 1353 inode->i_flags |= S_SYNC; 1354 if (flags & EXT2_APPEND_FL) 1355 inode->i_flags |= S_APPEND; 1356 if (flags & EXT2_IMMUTABLE_FL) 1357 inode->i_flags |= S_IMMUTABLE; 1358 if (flags & EXT2_NOATIME_FL) 1359 inode->i_flags |= S_NOATIME; 1360 if (flags & EXT2_DIRSYNC_FL) 1361 inode->i_flags |= S_DIRSYNC; 1362 if (test_opt(inode->i_sb, DAX) && S_ISREG(inode->i_mode)) 1363 inode->i_flags |= S_DAX; 1364 } 1365 1366 void ext2_set_file_ops(struct inode *inode) 1367 { 1368 inode->i_op = &ext2_file_inode_operations; 1369 inode->i_fop = &ext2_file_operations; 1370 if (IS_DAX(inode)) 1371 inode->i_mapping->a_ops = &ext2_dax_aops; 1372 else 1373 inode->i_mapping->a_ops = &ext2_aops; 1374 } 1375 1376 struct inode *ext2_iget (struct super_block *sb, unsigned long ino) 1377 { 1378 struct ext2_inode_info *ei; 1379 struct buffer_head * bh = NULL; 1380 struct ext2_inode *raw_inode; 1381 struct inode *inode; 1382 long ret = -EIO; 1383 int n; 1384 uid_t i_uid; 1385 gid_t i_gid; 1386 1387 inode = iget_locked(sb, ino); 1388 if (!inode) 1389 return ERR_PTR(-ENOMEM); 1390 if (!(inode->i_state & I_NEW)) 1391 return inode; 1392 1393 ei = EXT2_I(inode); 1394 ei->i_block_alloc_info = NULL; 1395 1396 raw_inode = ext2_get_inode(inode->i_sb, ino, &bh); 1397 if (IS_ERR(raw_inode)) { 1398 ret = PTR_ERR(raw_inode); 1399 goto bad_inode; 1400 } 1401 1402 inode->i_mode = le16_to_cpu(raw_inode->i_mode); 1403 i_uid = (uid_t)le16_to_cpu(raw_inode->i_uid_low); 1404 i_gid = (gid_t)le16_to_cpu(raw_inode->i_gid_low); 1405 if (!(test_opt (inode->i_sb, NO_UID32))) { 1406 i_uid |= le16_to_cpu(raw_inode->i_uid_high) << 16; 1407 i_gid |= le16_to_cpu(raw_inode->i_gid_high) << 16; 1408 } 1409 i_uid_write(inode, i_uid); 1410 i_gid_write(inode, i_gid); 1411 set_nlink(inode, le16_to_cpu(raw_inode->i_links_count)); 1412 inode->i_size = le32_to_cpu(raw_inode->i_size); 1413 inode_set_atime(inode, (signed)le32_to_cpu(raw_inode->i_atime), 0); 1414 inode_set_ctime(inode, (signed)le32_to_cpu(raw_inode->i_ctime), 0); 1415 inode_set_mtime(inode, (signed)le32_to_cpu(raw_inode->i_mtime), 0); 1416 ei->i_dtime = le32_to_cpu(raw_inode->i_dtime); 1417 /* We now have enough fields to check if the inode was active or not. 1418 * This is needed because nfsd might try to access dead inodes 1419 * the test is that same one that e2fsck uses 1420 * NeilBrown 1999oct15 1421 */ 1422 if (inode->i_nlink == 0 && (inode->i_mode == 0 || ei->i_dtime)) { 1423 /* this inode is deleted */ 1424 ret = -ESTALE; 1425 goto bad_inode; 1426 } 1427 inode->i_blocks = le32_to_cpu(raw_inode->i_blocks); 1428 ei->i_flags = le32_to_cpu(raw_inode->i_flags); 1429 ext2_set_inode_flags(inode); 1430 ei->i_faddr = le32_to_cpu(raw_inode->i_faddr); 1431 ei->i_frag_no = raw_inode->i_frag; 1432 ei->i_frag_size = raw_inode->i_fsize; 1433 ei->i_file_acl = le32_to_cpu(raw_inode->i_file_acl); 1434 ei->i_dir_acl = 0; 1435 1436 if (ei->i_file_acl && 1437 !ext2_data_block_valid(EXT2_SB(sb), ei->i_file_acl, 1)) { 1438 ext2_error(sb, "ext2_iget", "bad extended attribute block %u", 1439 ei->i_file_acl); 1440 ret = -EFSCORRUPTED; 1441 goto bad_inode; 1442 } 1443 1444 if (S_ISREG(inode->i_mode)) 1445 inode->i_size |= ((__u64)le32_to_cpu(raw_inode->i_size_high)) << 32; 1446 else 1447 ei->i_dir_acl = le32_to_cpu(raw_inode->i_dir_acl); 1448 if (i_size_read(inode) < 0) { 1449 ret = -EFSCORRUPTED; 1450 goto bad_inode; 1451 } 1452 ei->i_dtime = 0; 1453 inode->i_generation = le32_to_cpu(raw_inode->i_generation); 1454 ei->i_state = 0; 1455 ei->i_block_group = (ino - 1) / EXT2_INODES_PER_GROUP(inode->i_sb); 1456 ei->i_dir_start_lookup = 0; 1457 1458 /* 1459 * NOTE! The in-memory inode i_data array is in little-endian order 1460 * even on big-endian machines: we do NOT byteswap the block numbers! 1461 */ 1462 for (n = 0; n < EXT2_N_BLOCKS; n++) 1463 ei->i_data[n] = raw_inode->i_block[n]; 1464 1465 if (S_ISREG(inode->i_mode)) { 1466 ext2_set_file_ops(inode); 1467 } else if (S_ISDIR(inode->i_mode)) { 1468 inode->i_op = &ext2_dir_inode_operations; 1469 inode->i_fop = &ext2_dir_operations; 1470 inode->i_mapping->a_ops = &ext2_aops; 1471 } else if (S_ISLNK(inode->i_mode)) { 1472 if (ext2_inode_is_fast_symlink(inode)) { 1473 inode->i_link = (char *)ei->i_data; 1474 inode->i_op = &ext2_fast_symlink_inode_operations; 1475 nd_terminate_link(ei->i_data, inode->i_size, 1476 sizeof(ei->i_data) - 1); 1477 } else { 1478 inode->i_op = &ext2_symlink_inode_operations; 1479 inode_nohighmem(inode); 1480 inode->i_mapping->a_ops = &ext2_aops; 1481 } 1482 } else { 1483 inode->i_op = &ext2_special_inode_operations; 1484 if (raw_inode->i_block[0]) 1485 init_special_inode(inode, inode->i_mode, 1486 old_decode_dev(le32_to_cpu(raw_inode->i_block[0]))); 1487 else 1488 init_special_inode(inode, inode->i_mode, 1489 new_decode_dev(le32_to_cpu(raw_inode->i_block[1]))); 1490 } 1491 brelse (bh); 1492 unlock_new_inode(inode); 1493 return inode; 1494 1495 bad_inode: 1496 brelse(bh); 1497 iget_failed(inode); 1498 return ERR_PTR(ret); 1499 } 1500 1501 static int __ext2_write_inode(struct inode *inode, int do_sync) 1502 { 1503 struct ext2_inode_info *ei = EXT2_I(inode); 1504 struct super_block *sb = inode->i_sb; 1505 ino_t ino = inode->i_ino; 1506 uid_t uid = i_uid_read(inode); 1507 gid_t gid = i_gid_read(inode); 1508 struct buffer_head * bh; 1509 struct ext2_inode * raw_inode = ext2_get_inode(sb, ino, &bh); 1510 int n; 1511 int err = 0; 1512 1513 if (IS_ERR(raw_inode)) 1514 return -EIO; 1515 1516 /* For fields not tracking in the in-memory inode, 1517 * initialise them to zero for new inodes. */ 1518 if (ei->i_state & EXT2_STATE_NEW) 1519 memset(raw_inode, 0, EXT2_SB(sb)->s_inode_size); 1520 1521 raw_inode->i_mode = cpu_to_le16(inode->i_mode); 1522 if (!(test_opt(sb, NO_UID32))) { 1523 raw_inode->i_uid_low = cpu_to_le16(low_16_bits(uid)); 1524 raw_inode->i_gid_low = cpu_to_le16(low_16_bits(gid)); 1525 /* 1526 * Fix up interoperability with old kernels. Otherwise, old inodes get 1527 * re-used with the upper 16 bits of the uid/gid intact 1528 */ 1529 if (!ei->i_dtime) { 1530 raw_inode->i_uid_high = cpu_to_le16(high_16_bits(uid)); 1531 raw_inode->i_gid_high = cpu_to_le16(high_16_bits(gid)); 1532 } else { 1533 raw_inode->i_uid_high = 0; 1534 raw_inode->i_gid_high = 0; 1535 } 1536 } else { 1537 raw_inode->i_uid_low = cpu_to_le16(fs_high2lowuid(uid)); 1538 raw_inode->i_gid_low = cpu_to_le16(fs_high2lowgid(gid)); 1539 raw_inode->i_uid_high = 0; 1540 raw_inode->i_gid_high = 0; 1541 } 1542 raw_inode->i_links_count = cpu_to_le16(inode->i_nlink); 1543 raw_inode->i_size = cpu_to_le32(inode->i_size); 1544 raw_inode->i_atime = cpu_to_le32(inode_get_atime_sec(inode)); 1545 raw_inode->i_ctime = cpu_to_le32(inode_get_ctime_sec(inode)); 1546 raw_inode->i_mtime = cpu_to_le32(inode_get_mtime_sec(inode)); 1547 1548 raw_inode->i_blocks = cpu_to_le32(inode->i_blocks); 1549 raw_inode->i_dtime = cpu_to_le32(ei->i_dtime); 1550 raw_inode->i_flags = cpu_to_le32(ei->i_flags); 1551 raw_inode->i_faddr = cpu_to_le32(ei->i_faddr); 1552 raw_inode->i_frag = ei->i_frag_no; 1553 raw_inode->i_fsize = ei->i_frag_size; 1554 raw_inode->i_file_acl = cpu_to_le32(ei->i_file_acl); 1555 if (!S_ISREG(inode->i_mode)) 1556 raw_inode->i_dir_acl = cpu_to_le32(ei->i_dir_acl); 1557 else { 1558 raw_inode->i_size_high = cpu_to_le32(inode->i_size >> 32); 1559 if (inode->i_size > 0x7fffffffULL) { 1560 if (!EXT2_HAS_RO_COMPAT_FEATURE(sb, 1561 EXT2_FEATURE_RO_COMPAT_LARGE_FILE) || 1562 EXT2_SB(sb)->s_es->s_rev_level == 1563 cpu_to_le32(EXT2_GOOD_OLD_REV)) { 1564 /* If this is the first large file 1565 * created, add a flag to the superblock. 1566 */ 1567 spin_lock(&EXT2_SB(sb)->s_lock); 1568 ext2_update_dynamic_rev(sb); 1569 EXT2_SET_RO_COMPAT_FEATURE(sb, 1570 EXT2_FEATURE_RO_COMPAT_LARGE_FILE); 1571 spin_unlock(&EXT2_SB(sb)->s_lock); 1572 ext2_sync_super(sb, EXT2_SB(sb)->s_es, 1); 1573 } 1574 } 1575 } 1576 1577 raw_inode->i_generation = cpu_to_le32(inode->i_generation); 1578 if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) { 1579 if (old_valid_dev(inode->i_rdev)) { 1580 raw_inode->i_block[0] = 1581 cpu_to_le32(old_encode_dev(inode->i_rdev)); 1582 raw_inode->i_block[1] = 0; 1583 } else { 1584 raw_inode->i_block[0] = 0; 1585 raw_inode->i_block[1] = 1586 cpu_to_le32(new_encode_dev(inode->i_rdev)); 1587 raw_inode->i_block[2] = 0; 1588 } 1589 } else for (n = 0; n < EXT2_N_BLOCKS; n++) 1590 raw_inode->i_block[n] = ei->i_data[n]; 1591 mark_buffer_dirty(bh); 1592 if (do_sync) { 1593 sync_dirty_buffer(bh); 1594 if (buffer_req(bh) && !buffer_uptodate(bh)) { 1595 printk ("IO error syncing ext2 inode [%s:%08lx]\n", 1596 sb->s_id, (unsigned long) ino); 1597 err = -EIO; 1598 } 1599 } 1600 ei->i_state &= ~EXT2_STATE_NEW; 1601 brelse (bh); 1602 return err; 1603 } 1604 1605 int ext2_write_inode(struct inode *inode, struct writeback_control *wbc) 1606 { 1607 return __ext2_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL); 1608 } 1609 1610 int ext2_getattr(struct mnt_idmap *idmap, const struct path *path, 1611 struct kstat *stat, u32 request_mask, unsigned int query_flags) 1612 { 1613 struct inode *inode = d_inode(path->dentry); 1614 struct ext2_inode_info *ei = EXT2_I(inode); 1615 unsigned int flags; 1616 1617 flags = ei->i_flags & EXT2_FL_USER_VISIBLE; 1618 if (flags & EXT2_APPEND_FL) 1619 stat->attributes |= STATX_ATTR_APPEND; 1620 if (flags & EXT2_COMPR_FL) 1621 stat->attributes |= STATX_ATTR_COMPRESSED; 1622 if (flags & EXT2_IMMUTABLE_FL) 1623 stat->attributes |= STATX_ATTR_IMMUTABLE; 1624 if (flags & EXT2_NODUMP_FL) 1625 stat->attributes |= STATX_ATTR_NODUMP; 1626 stat->attributes_mask |= (STATX_ATTR_APPEND | 1627 STATX_ATTR_COMPRESSED | 1628 STATX_ATTR_ENCRYPTED | 1629 STATX_ATTR_IMMUTABLE | 1630 STATX_ATTR_NODUMP); 1631 1632 generic_fillattr(&nop_mnt_idmap, request_mask, inode, stat); 1633 return 0; 1634 } 1635 1636 int ext2_setattr(struct mnt_idmap *idmap, struct dentry *dentry, 1637 struct iattr *iattr) 1638 { 1639 struct inode *inode = d_inode(dentry); 1640 int error; 1641 1642 error = setattr_prepare(&nop_mnt_idmap, dentry, iattr); 1643 if (error) 1644 return error; 1645 1646 if (is_quota_modification(&nop_mnt_idmap, inode, iattr)) { 1647 error = dquot_initialize(inode); 1648 if (error) 1649 return error; 1650 } 1651 if (i_uid_needs_update(&nop_mnt_idmap, iattr, inode) || 1652 i_gid_needs_update(&nop_mnt_idmap, iattr, inode)) { 1653 error = dquot_transfer(&nop_mnt_idmap, inode, iattr); 1654 if (error) 1655 return error; 1656 } 1657 if (iattr->ia_valid & ATTR_SIZE && iattr->ia_size != inode->i_size) { 1658 error = ext2_setsize(inode, iattr->ia_size); 1659 if (error) 1660 return error; 1661 } 1662 setattr_copy(&nop_mnt_idmap, inode, iattr); 1663 if (iattr->ia_valid & ATTR_MODE) 1664 error = posix_acl_chmod(&nop_mnt_idmap, dentry, inode->i_mode); 1665 mark_inode_dirty(inode); 1666 1667 return error; 1668 } 1669