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_NOFS); 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 .direct_IO = noop_direct_IO, 969 .writepages = ext2_writepages, 970 .migrate_folio = buffer_migrate_folio, 971 .is_partially_uptodate = block_is_partially_uptodate, 972 .error_remove_page = generic_error_remove_page, 973 }; 974 975 static const struct address_space_operations ext2_dax_aops = { 976 .writepages = ext2_dax_writepages, 977 .direct_IO = noop_direct_IO, 978 .dirty_folio = noop_dirty_folio, 979 }; 980 981 /* 982 * Probably it should be a library function... search for first non-zero word 983 * or memcmp with zero_page, whatever is better for particular architecture. 984 * Linus? 985 */ 986 static inline int all_zeroes(__le32 *p, __le32 *q) 987 { 988 while (p < q) 989 if (*p++) 990 return 0; 991 return 1; 992 } 993 994 /** 995 * ext2_find_shared - find the indirect blocks for partial truncation. 996 * @inode: inode in question 997 * @depth: depth of the affected branch 998 * @offsets: offsets of pointers in that branch (see ext2_block_to_path) 999 * @chain: place to store the pointers to partial indirect blocks 1000 * @top: place to the (detached) top of branch 1001 * 1002 * This is a helper function used by ext2_truncate(). 1003 * 1004 * When we do truncate() we may have to clean the ends of several indirect 1005 * blocks but leave the blocks themselves alive. Block is partially 1006 * truncated if some data below the new i_size is referred from it (and 1007 * it is on the path to the first completely truncated data block, indeed). 1008 * We have to free the top of that path along with everything to the right 1009 * of the path. Since no allocation past the truncation point is possible 1010 * until ext2_truncate() finishes, we may safely do the latter, but top 1011 * of branch may require special attention - pageout below the truncation 1012 * point might try to populate it. 1013 * 1014 * We atomically detach the top of branch from the tree, store the block 1015 * number of its root in *@top, pointers to buffer_heads of partially 1016 * truncated blocks - in @chain[].bh and pointers to their last elements 1017 * that should not be removed - in @chain[].p. Return value is the pointer 1018 * to last filled element of @chain. 1019 * 1020 * The work left to caller to do the actual freeing of subtrees: 1021 * a) free the subtree starting from *@top 1022 * b) free the subtrees whose roots are stored in 1023 * (@chain[i].p+1 .. end of @chain[i].bh->b_data) 1024 * c) free the subtrees growing from the inode past the @chain[0].p 1025 * (no partially truncated stuff there). 1026 */ 1027 1028 static Indirect *ext2_find_shared(struct inode *inode, 1029 int depth, 1030 int offsets[4], 1031 Indirect chain[4], 1032 __le32 *top) 1033 { 1034 Indirect *partial, *p; 1035 int k, err; 1036 1037 *top = 0; 1038 for (k = depth; k > 1 && !offsets[k-1]; k--) 1039 ; 1040 partial = ext2_get_branch(inode, k, offsets, chain, &err); 1041 if (!partial) 1042 partial = chain + k-1; 1043 /* 1044 * If the branch acquired continuation since we've looked at it - 1045 * fine, it should all survive and (new) top doesn't belong to us. 1046 */ 1047 write_lock(&EXT2_I(inode)->i_meta_lock); 1048 if (!partial->key && *partial->p) { 1049 write_unlock(&EXT2_I(inode)->i_meta_lock); 1050 goto no_top; 1051 } 1052 for (p=partial; p>chain && all_zeroes((__le32*)p->bh->b_data,p->p); p--) 1053 ; 1054 /* 1055 * OK, we've found the last block that must survive. The rest of our 1056 * branch should be detached before unlocking. However, if that rest 1057 * of branch is all ours and does not grow immediately from the inode 1058 * it's easier to cheat and just decrement partial->p. 1059 */ 1060 if (p == chain + k - 1 && p > chain) { 1061 p->p--; 1062 } else { 1063 *top = *p->p; 1064 *p->p = 0; 1065 } 1066 write_unlock(&EXT2_I(inode)->i_meta_lock); 1067 1068 while(partial > p) 1069 { 1070 brelse(partial->bh); 1071 partial--; 1072 } 1073 no_top: 1074 return partial; 1075 } 1076 1077 /** 1078 * ext2_free_data - free a list of data blocks 1079 * @inode: inode we are dealing with 1080 * @p: array of block numbers 1081 * @q: points immediately past the end of array 1082 * 1083 * We are freeing all blocks referred from that array (numbers are 1084 * stored as little-endian 32-bit) and updating @inode->i_blocks 1085 * appropriately. 1086 */ 1087 static inline void ext2_free_data(struct inode *inode, __le32 *p, __le32 *q) 1088 { 1089 ext2_fsblk_t block_to_free = 0, count = 0; 1090 ext2_fsblk_t nr; 1091 1092 for ( ; p < q ; p++) { 1093 nr = le32_to_cpu(*p); 1094 if (nr) { 1095 *p = 0; 1096 /* accumulate blocks to free if they're contiguous */ 1097 if (count == 0) 1098 goto free_this; 1099 else if (block_to_free == nr - count) 1100 count++; 1101 else { 1102 ext2_free_blocks (inode, block_to_free, count); 1103 mark_inode_dirty(inode); 1104 free_this: 1105 block_to_free = nr; 1106 count = 1; 1107 } 1108 } 1109 } 1110 if (count > 0) { 1111 ext2_free_blocks (inode, block_to_free, count); 1112 mark_inode_dirty(inode); 1113 } 1114 } 1115 1116 /** 1117 * ext2_free_branches - free an array of branches 1118 * @inode: inode we are dealing with 1119 * @p: array of block numbers 1120 * @q: pointer immediately past the end of array 1121 * @depth: depth of the branches to free 1122 * 1123 * We are freeing all blocks referred from these branches (numbers are 1124 * stored as little-endian 32-bit) and updating @inode->i_blocks 1125 * appropriately. 1126 */ 1127 static void ext2_free_branches(struct inode *inode, __le32 *p, __le32 *q, int depth) 1128 { 1129 struct buffer_head * bh; 1130 ext2_fsblk_t nr; 1131 1132 if (depth--) { 1133 int addr_per_block = EXT2_ADDR_PER_BLOCK(inode->i_sb); 1134 for ( ; p < q ; p++) { 1135 nr = le32_to_cpu(*p); 1136 if (!nr) 1137 continue; 1138 *p = 0; 1139 bh = sb_bread(inode->i_sb, nr); 1140 /* 1141 * A read failure? Report error and clear slot 1142 * (should be rare). 1143 */ 1144 if (!bh) { 1145 ext2_error(inode->i_sb, "ext2_free_branches", 1146 "Read failure, inode=%ld, block=%ld", 1147 inode->i_ino, nr); 1148 continue; 1149 } 1150 ext2_free_branches(inode, 1151 (__le32*)bh->b_data, 1152 (__le32*)bh->b_data + addr_per_block, 1153 depth); 1154 bforget(bh); 1155 ext2_free_blocks(inode, nr, 1); 1156 mark_inode_dirty(inode); 1157 } 1158 } else 1159 ext2_free_data(inode, p, q); 1160 } 1161 1162 /* mapping->invalidate_lock must be held when calling this function */ 1163 static void __ext2_truncate_blocks(struct inode *inode, loff_t offset) 1164 { 1165 __le32 *i_data = EXT2_I(inode)->i_data; 1166 struct ext2_inode_info *ei = EXT2_I(inode); 1167 int addr_per_block = EXT2_ADDR_PER_BLOCK(inode->i_sb); 1168 int offsets[4]; 1169 Indirect chain[4]; 1170 Indirect *partial; 1171 __le32 nr = 0; 1172 int n; 1173 long iblock; 1174 unsigned blocksize; 1175 blocksize = inode->i_sb->s_blocksize; 1176 iblock = (offset + blocksize-1) >> EXT2_BLOCK_SIZE_BITS(inode->i_sb); 1177 1178 #ifdef CONFIG_FS_DAX 1179 WARN_ON(!rwsem_is_locked(&inode->i_mapping->invalidate_lock)); 1180 #endif 1181 1182 n = ext2_block_to_path(inode, iblock, offsets, NULL); 1183 if (n == 0) 1184 return; 1185 1186 /* 1187 * From here we block out all ext2_get_block() callers who want to 1188 * modify the block allocation tree. 1189 */ 1190 mutex_lock(&ei->truncate_mutex); 1191 1192 if (n == 1) { 1193 ext2_free_data(inode, i_data+offsets[0], 1194 i_data + EXT2_NDIR_BLOCKS); 1195 goto do_indirects; 1196 } 1197 1198 partial = ext2_find_shared(inode, n, offsets, chain, &nr); 1199 /* Kill the top of shared branch (already detached) */ 1200 if (nr) { 1201 if (partial == chain) 1202 mark_inode_dirty(inode); 1203 else 1204 mark_buffer_dirty_inode(partial->bh, inode); 1205 ext2_free_branches(inode, &nr, &nr+1, (chain+n-1) - partial); 1206 } 1207 /* Clear the ends of indirect blocks on the shared branch */ 1208 while (partial > chain) { 1209 ext2_free_branches(inode, 1210 partial->p + 1, 1211 (__le32*)partial->bh->b_data+addr_per_block, 1212 (chain+n-1) - partial); 1213 mark_buffer_dirty_inode(partial->bh, inode); 1214 brelse (partial->bh); 1215 partial--; 1216 } 1217 do_indirects: 1218 /* Kill the remaining (whole) subtrees */ 1219 switch (offsets[0]) { 1220 default: 1221 nr = i_data[EXT2_IND_BLOCK]; 1222 if (nr) { 1223 i_data[EXT2_IND_BLOCK] = 0; 1224 mark_inode_dirty(inode); 1225 ext2_free_branches(inode, &nr, &nr+1, 1); 1226 } 1227 fallthrough; 1228 case EXT2_IND_BLOCK: 1229 nr = i_data[EXT2_DIND_BLOCK]; 1230 if (nr) { 1231 i_data[EXT2_DIND_BLOCK] = 0; 1232 mark_inode_dirty(inode); 1233 ext2_free_branches(inode, &nr, &nr+1, 2); 1234 } 1235 fallthrough; 1236 case EXT2_DIND_BLOCK: 1237 nr = i_data[EXT2_TIND_BLOCK]; 1238 if (nr) { 1239 i_data[EXT2_TIND_BLOCK] = 0; 1240 mark_inode_dirty(inode); 1241 ext2_free_branches(inode, &nr, &nr+1, 3); 1242 } 1243 break; 1244 case EXT2_TIND_BLOCK: 1245 ; 1246 } 1247 1248 ext2_discard_reservation(inode); 1249 1250 mutex_unlock(&ei->truncate_mutex); 1251 } 1252 1253 static void ext2_truncate_blocks(struct inode *inode, loff_t offset) 1254 { 1255 if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || 1256 S_ISLNK(inode->i_mode))) 1257 return; 1258 if (ext2_inode_is_fast_symlink(inode)) 1259 return; 1260 1261 filemap_invalidate_lock(inode->i_mapping); 1262 __ext2_truncate_blocks(inode, offset); 1263 filemap_invalidate_unlock(inode->i_mapping); 1264 } 1265 1266 static int ext2_setsize(struct inode *inode, loff_t newsize) 1267 { 1268 int error; 1269 1270 if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || 1271 S_ISLNK(inode->i_mode))) 1272 return -EINVAL; 1273 if (ext2_inode_is_fast_symlink(inode)) 1274 return -EINVAL; 1275 if (IS_APPEND(inode) || IS_IMMUTABLE(inode)) 1276 return -EPERM; 1277 1278 inode_dio_wait(inode); 1279 1280 if (IS_DAX(inode)) 1281 error = dax_truncate_page(inode, newsize, NULL, 1282 &ext2_iomap_ops); 1283 else 1284 error = block_truncate_page(inode->i_mapping, 1285 newsize, ext2_get_block); 1286 if (error) 1287 return error; 1288 1289 filemap_invalidate_lock(inode->i_mapping); 1290 truncate_setsize(inode, newsize); 1291 __ext2_truncate_blocks(inode, newsize); 1292 filemap_invalidate_unlock(inode->i_mapping); 1293 1294 inode->i_mtime = inode_set_ctime_current(inode); 1295 if (inode_needs_sync(inode)) { 1296 sync_mapping_buffers(inode->i_mapping); 1297 sync_inode_metadata(inode, 1); 1298 } else { 1299 mark_inode_dirty(inode); 1300 } 1301 1302 return 0; 1303 } 1304 1305 static struct ext2_inode *ext2_get_inode(struct super_block *sb, ino_t ino, 1306 struct buffer_head **p) 1307 { 1308 struct buffer_head * bh; 1309 unsigned long block_group; 1310 unsigned long block; 1311 unsigned long offset; 1312 struct ext2_group_desc * gdp; 1313 1314 *p = NULL; 1315 if ((ino != EXT2_ROOT_INO && ino < EXT2_FIRST_INO(sb)) || 1316 ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count)) 1317 goto Einval; 1318 1319 block_group = (ino - 1) / EXT2_INODES_PER_GROUP(sb); 1320 gdp = ext2_get_group_desc(sb, block_group, NULL); 1321 if (!gdp) 1322 goto Egdp; 1323 /* 1324 * Figure out the offset within the block group inode table 1325 */ 1326 offset = ((ino - 1) % EXT2_INODES_PER_GROUP(sb)) * EXT2_INODE_SIZE(sb); 1327 block = le32_to_cpu(gdp->bg_inode_table) + 1328 (offset >> EXT2_BLOCK_SIZE_BITS(sb)); 1329 if (!(bh = sb_bread(sb, block))) 1330 goto Eio; 1331 1332 *p = bh; 1333 offset &= (EXT2_BLOCK_SIZE(sb) - 1); 1334 return (struct ext2_inode *) (bh->b_data + offset); 1335 1336 Einval: 1337 ext2_error(sb, "ext2_get_inode", "bad inode number: %lu", 1338 (unsigned long) ino); 1339 return ERR_PTR(-EINVAL); 1340 Eio: 1341 ext2_error(sb, "ext2_get_inode", 1342 "unable to read inode block - inode=%lu, block=%lu", 1343 (unsigned long) ino, block); 1344 Egdp: 1345 return ERR_PTR(-EIO); 1346 } 1347 1348 void ext2_set_inode_flags(struct inode *inode) 1349 { 1350 unsigned int flags = EXT2_I(inode)->i_flags; 1351 1352 inode->i_flags &= ~(S_SYNC | S_APPEND | S_IMMUTABLE | S_NOATIME | 1353 S_DIRSYNC | S_DAX); 1354 if (flags & EXT2_SYNC_FL) 1355 inode->i_flags |= S_SYNC; 1356 if (flags & EXT2_APPEND_FL) 1357 inode->i_flags |= S_APPEND; 1358 if (flags & EXT2_IMMUTABLE_FL) 1359 inode->i_flags |= S_IMMUTABLE; 1360 if (flags & EXT2_NOATIME_FL) 1361 inode->i_flags |= S_NOATIME; 1362 if (flags & EXT2_DIRSYNC_FL) 1363 inode->i_flags |= S_DIRSYNC; 1364 if (test_opt(inode->i_sb, DAX) && S_ISREG(inode->i_mode)) 1365 inode->i_flags |= S_DAX; 1366 } 1367 1368 void ext2_set_file_ops(struct inode *inode) 1369 { 1370 inode->i_op = &ext2_file_inode_operations; 1371 inode->i_fop = &ext2_file_operations; 1372 if (IS_DAX(inode)) 1373 inode->i_mapping->a_ops = &ext2_dax_aops; 1374 else 1375 inode->i_mapping->a_ops = &ext2_aops; 1376 } 1377 1378 struct inode *ext2_iget (struct super_block *sb, unsigned long ino) 1379 { 1380 struct ext2_inode_info *ei; 1381 struct buffer_head * bh = NULL; 1382 struct ext2_inode *raw_inode; 1383 struct inode *inode; 1384 long ret = -EIO; 1385 int n; 1386 uid_t i_uid; 1387 gid_t i_gid; 1388 1389 inode = iget_locked(sb, ino); 1390 if (!inode) 1391 return ERR_PTR(-ENOMEM); 1392 if (!(inode->i_state & I_NEW)) 1393 return inode; 1394 1395 ei = EXT2_I(inode); 1396 ei->i_block_alloc_info = NULL; 1397 1398 raw_inode = ext2_get_inode(inode->i_sb, ino, &bh); 1399 if (IS_ERR(raw_inode)) { 1400 ret = PTR_ERR(raw_inode); 1401 goto bad_inode; 1402 } 1403 1404 inode->i_mode = le16_to_cpu(raw_inode->i_mode); 1405 i_uid = (uid_t)le16_to_cpu(raw_inode->i_uid_low); 1406 i_gid = (gid_t)le16_to_cpu(raw_inode->i_gid_low); 1407 if (!(test_opt (inode->i_sb, NO_UID32))) { 1408 i_uid |= le16_to_cpu(raw_inode->i_uid_high) << 16; 1409 i_gid |= le16_to_cpu(raw_inode->i_gid_high) << 16; 1410 } 1411 i_uid_write(inode, i_uid); 1412 i_gid_write(inode, i_gid); 1413 set_nlink(inode, le16_to_cpu(raw_inode->i_links_count)); 1414 inode->i_size = le32_to_cpu(raw_inode->i_size); 1415 inode->i_atime.tv_sec = (signed)le32_to_cpu(raw_inode->i_atime); 1416 inode_set_ctime(inode, (signed)le32_to_cpu(raw_inode->i_ctime), 0); 1417 inode->i_mtime.tv_sec = (signed)le32_to_cpu(raw_inode->i_mtime); 1418 inode->i_atime.tv_nsec = inode->i_mtime.tv_nsec = 0; 1419 ei->i_dtime = le32_to_cpu(raw_inode->i_dtime); 1420 /* We now have enough fields to check if the inode was active or not. 1421 * This is needed because nfsd might try to access dead inodes 1422 * the test is that same one that e2fsck uses 1423 * NeilBrown 1999oct15 1424 */ 1425 if (inode->i_nlink == 0 && (inode->i_mode == 0 || ei->i_dtime)) { 1426 /* this inode is deleted */ 1427 ret = -ESTALE; 1428 goto bad_inode; 1429 } 1430 inode->i_blocks = le32_to_cpu(raw_inode->i_blocks); 1431 ei->i_flags = le32_to_cpu(raw_inode->i_flags); 1432 ext2_set_inode_flags(inode); 1433 ei->i_faddr = le32_to_cpu(raw_inode->i_faddr); 1434 ei->i_frag_no = raw_inode->i_frag; 1435 ei->i_frag_size = raw_inode->i_fsize; 1436 ei->i_file_acl = le32_to_cpu(raw_inode->i_file_acl); 1437 ei->i_dir_acl = 0; 1438 1439 if (ei->i_file_acl && 1440 !ext2_data_block_valid(EXT2_SB(sb), ei->i_file_acl, 1)) { 1441 ext2_error(sb, "ext2_iget", "bad extended attribute block %u", 1442 ei->i_file_acl); 1443 ret = -EFSCORRUPTED; 1444 goto bad_inode; 1445 } 1446 1447 if (S_ISREG(inode->i_mode)) 1448 inode->i_size |= ((__u64)le32_to_cpu(raw_inode->i_size_high)) << 32; 1449 else 1450 ei->i_dir_acl = le32_to_cpu(raw_inode->i_dir_acl); 1451 if (i_size_read(inode) < 0) { 1452 ret = -EFSCORRUPTED; 1453 goto bad_inode; 1454 } 1455 ei->i_dtime = 0; 1456 inode->i_generation = le32_to_cpu(raw_inode->i_generation); 1457 ei->i_state = 0; 1458 ei->i_block_group = (ino - 1) / EXT2_INODES_PER_GROUP(inode->i_sb); 1459 ei->i_dir_start_lookup = 0; 1460 1461 /* 1462 * NOTE! The in-memory inode i_data array is in little-endian order 1463 * even on big-endian machines: we do NOT byteswap the block numbers! 1464 */ 1465 for (n = 0; n < EXT2_N_BLOCKS; n++) 1466 ei->i_data[n] = raw_inode->i_block[n]; 1467 1468 if (S_ISREG(inode->i_mode)) { 1469 ext2_set_file_ops(inode); 1470 } else if (S_ISDIR(inode->i_mode)) { 1471 inode->i_op = &ext2_dir_inode_operations; 1472 inode->i_fop = &ext2_dir_operations; 1473 inode->i_mapping->a_ops = &ext2_aops; 1474 } else if (S_ISLNK(inode->i_mode)) { 1475 if (ext2_inode_is_fast_symlink(inode)) { 1476 inode->i_link = (char *)ei->i_data; 1477 inode->i_op = &ext2_fast_symlink_inode_operations; 1478 nd_terminate_link(ei->i_data, inode->i_size, 1479 sizeof(ei->i_data) - 1); 1480 } else { 1481 inode->i_op = &ext2_symlink_inode_operations; 1482 inode_nohighmem(inode); 1483 inode->i_mapping->a_ops = &ext2_aops; 1484 } 1485 } else { 1486 inode->i_op = &ext2_special_inode_operations; 1487 if (raw_inode->i_block[0]) 1488 init_special_inode(inode, inode->i_mode, 1489 old_decode_dev(le32_to_cpu(raw_inode->i_block[0]))); 1490 else 1491 init_special_inode(inode, inode->i_mode, 1492 new_decode_dev(le32_to_cpu(raw_inode->i_block[1]))); 1493 } 1494 brelse (bh); 1495 unlock_new_inode(inode); 1496 return inode; 1497 1498 bad_inode: 1499 brelse(bh); 1500 iget_failed(inode); 1501 return ERR_PTR(ret); 1502 } 1503 1504 static int __ext2_write_inode(struct inode *inode, int do_sync) 1505 { 1506 struct ext2_inode_info *ei = EXT2_I(inode); 1507 struct super_block *sb = inode->i_sb; 1508 ino_t ino = inode->i_ino; 1509 uid_t uid = i_uid_read(inode); 1510 gid_t gid = i_gid_read(inode); 1511 struct buffer_head * bh; 1512 struct ext2_inode * raw_inode = ext2_get_inode(sb, ino, &bh); 1513 int n; 1514 int err = 0; 1515 1516 if (IS_ERR(raw_inode)) 1517 return -EIO; 1518 1519 /* For fields not tracking in the in-memory inode, 1520 * initialise them to zero for new inodes. */ 1521 if (ei->i_state & EXT2_STATE_NEW) 1522 memset(raw_inode, 0, EXT2_SB(sb)->s_inode_size); 1523 1524 raw_inode->i_mode = cpu_to_le16(inode->i_mode); 1525 if (!(test_opt(sb, NO_UID32))) { 1526 raw_inode->i_uid_low = cpu_to_le16(low_16_bits(uid)); 1527 raw_inode->i_gid_low = cpu_to_le16(low_16_bits(gid)); 1528 /* 1529 * Fix up interoperability with old kernels. Otherwise, old inodes get 1530 * re-used with the upper 16 bits of the uid/gid intact 1531 */ 1532 if (!ei->i_dtime) { 1533 raw_inode->i_uid_high = cpu_to_le16(high_16_bits(uid)); 1534 raw_inode->i_gid_high = cpu_to_le16(high_16_bits(gid)); 1535 } else { 1536 raw_inode->i_uid_high = 0; 1537 raw_inode->i_gid_high = 0; 1538 } 1539 } else { 1540 raw_inode->i_uid_low = cpu_to_le16(fs_high2lowuid(uid)); 1541 raw_inode->i_gid_low = cpu_to_le16(fs_high2lowgid(gid)); 1542 raw_inode->i_uid_high = 0; 1543 raw_inode->i_gid_high = 0; 1544 } 1545 raw_inode->i_links_count = cpu_to_le16(inode->i_nlink); 1546 raw_inode->i_size = cpu_to_le32(inode->i_size); 1547 raw_inode->i_atime = cpu_to_le32(inode->i_atime.tv_sec); 1548 raw_inode->i_ctime = cpu_to_le32(inode_get_ctime(inode).tv_sec); 1549 raw_inode->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec); 1550 1551 raw_inode->i_blocks = cpu_to_le32(inode->i_blocks); 1552 raw_inode->i_dtime = cpu_to_le32(ei->i_dtime); 1553 raw_inode->i_flags = cpu_to_le32(ei->i_flags); 1554 raw_inode->i_faddr = cpu_to_le32(ei->i_faddr); 1555 raw_inode->i_frag = ei->i_frag_no; 1556 raw_inode->i_fsize = ei->i_frag_size; 1557 raw_inode->i_file_acl = cpu_to_le32(ei->i_file_acl); 1558 if (!S_ISREG(inode->i_mode)) 1559 raw_inode->i_dir_acl = cpu_to_le32(ei->i_dir_acl); 1560 else { 1561 raw_inode->i_size_high = cpu_to_le32(inode->i_size >> 32); 1562 if (inode->i_size > 0x7fffffffULL) { 1563 if (!EXT2_HAS_RO_COMPAT_FEATURE(sb, 1564 EXT2_FEATURE_RO_COMPAT_LARGE_FILE) || 1565 EXT2_SB(sb)->s_es->s_rev_level == 1566 cpu_to_le32(EXT2_GOOD_OLD_REV)) { 1567 /* If this is the first large file 1568 * created, add a flag to the superblock. 1569 */ 1570 spin_lock(&EXT2_SB(sb)->s_lock); 1571 ext2_update_dynamic_rev(sb); 1572 EXT2_SET_RO_COMPAT_FEATURE(sb, 1573 EXT2_FEATURE_RO_COMPAT_LARGE_FILE); 1574 spin_unlock(&EXT2_SB(sb)->s_lock); 1575 ext2_sync_super(sb, EXT2_SB(sb)->s_es, 1); 1576 } 1577 } 1578 } 1579 1580 raw_inode->i_generation = cpu_to_le32(inode->i_generation); 1581 if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) { 1582 if (old_valid_dev(inode->i_rdev)) { 1583 raw_inode->i_block[0] = 1584 cpu_to_le32(old_encode_dev(inode->i_rdev)); 1585 raw_inode->i_block[1] = 0; 1586 } else { 1587 raw_inode->i_block[0] = 0; 1588 raw_inode->i_block[1] = 1589 cpu_to_le32(new_encode_dev(inode->i_rdev)); 1590 raw_inode->i_block[2] = 0; 1591 } 1592 } else for (n = 0; n < EXT2_N_BLOCKS; n++) 1593 raw_inode->i_block[n] = ei->i_data[n]; 1594 mark_buffer_dirty(bh); 1595 if (do_sync) { 1596 sync_dirty_buffer(bh); 1597 if (buffer_req(bh) && !buffer_uptodate(bh)) { 1598 printk ("IO error syncing ext2 inode [%s:%08lx]\n", 1599 sb->s_id, (unsigned long) ino); 1600 err = -EIO; 1601 } 1602 } 1603 ei->i_state &= ~EXT2_STATE_NEW; 1604 brelse (bh); 1605 return err; 1606 } 1607 1608 int ext2_write_inode(struct inode *inode, struct writeback_control *wbc) 1609 { 1610 return __ext2_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL); 1611 } 1612 1613 int ext2_getattr(struct mnt_idmap *idmap, const struct path *path, 1614 struct kstat *stat, u32 request_mask, unsigned int query_flags) 1615 { 1616 struct inode *inode = d_inode(path->dentry); 1617 struct ext2_inode_info *ei = EXT2_I(inode); 1618 unsigned int flags; 1619 1620 flags = ei->i_flags & EXT2_FL_USER_VISIBLE; 1621 if (flags & EXT2_APPEND_FL) 1622 stat->attributes |= STATX_ATTR_APPEND; 1623 if (flags & EXT2_COMPR_FL) 1624 stat->attributes |= STATX_ATTR_COMPRESSED; 1625 if (flags & EXT2_IMMUTABLE_FL) 1626 stat->attributes |= STATX_ATTR_IMMUTABLE; 1627 if (flags & EXT2_NODUMP_FL) 1628 stat->attributes |= STATX_ATTR_NODUMP; 1629 stat->attributes_mask |= (STATX_ATTR_APPEND | 1630 STATX_ATTR_COMPRESSED | 1631 STATX_ATTR_ENCRYPTED | 1632 STATX_ATTR_IMMUTABLE | 1633 STATX_ATTR_NODUMP); 1634 1635 generic_fillattr(&nop_mnt_idmap, request_mask, inode, stat); 1636 return 0; 1637 } 1638 1639 int ext2_setattr(struct mnt_idmap *idmap, struct dentry *dentry, 1640 struct iattr *iattr) 1641 { 1642 struct inode *inode = d_inode(dentry); 1643 int error; 1644 1645 error = setattr_prepare(&nop_mnt_idmap, dentry, iattr); 1646 if (error) 1647 return error; 1648 1649 if (is_quota_modification(&nop_mnt_idmap, inode, iattr)) { 1650 error = dquot_initialize(inode); 1651 if (error) 1652 return error; 1653 } 1654 if (i_uid_needs_update(&nop_mnt_idmap, iattr, inode) || 1655 i_gid_needs_update(&nop_mnt_idmap, iattr, inode)) { 1656 error = dquot_transfer(&nop_mnt_idmap, inode, iattr); 1657 if (error) 1658 return error; 1659 } 1660 if (iattr->ia_valid & ATTR_SIZE && iattr->ia_size != inode->i_size) { 1661 error = ext2_setsize(inode, iattr->ia_size); 1662 if (error) 1663 return error; 1664 } 1665 setattr_copy(&nop_mnt_idmap, inode, iattr); 1666 if (iattr->ia_valid & ATTR_MODE) 1667 error = posix_acl_chmod(&nop_mnt_idmap, dentry, inode->i_mode); 1668 mark_inode_dirty(inode); 1669 1670 return error; 1671 } 1672