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 static void ext2_write_failed(struct address_space *mapping, loff_t to) 60 { 61 struct inode *inode = mapping->host; 62 63 if (to > inode->i_size) { 64 truncate_pagecache(inode, 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: multiple allocate blocks needed for a branch 389 * @indirect_blks: the number of blocks need to allocate for indirect 390 * blocks 391 * @blks: the number of blocks need to allocate for direct blocks 392 * @new_blocks: on return it will store the new block numbers for 393 * the indirect blocks(if needed) and the first direct block, 394 */ 395 static int ext2_alloc_blocks(struct inode *inode, 396 ext2_fsblk_t goal, int indirect_blks, int blks, 397 ext2_fsblk_t new_blocks[4], int *err) 398 { 399 int target, i; 400 unsigned long count = 0; 401 int index = 0; 402 ext2_fsblk_t current_block = 0; 403 int ret = 0; 404 405 /* 406 * Here we try to allocate the requested multiple blocks at once, 407 * on a best-effort basis. 408 * To build a branch, we should allocate blocks for 409 * the indirect blocks(if not allocated yet), and at least 410 * the first direct block of this branch. That's the 411 * minimum number of blocks need to allocate(required) 412 */ 413 target = blks + indirect_blks; 414 415 while (1) { 416 count = target; 417 /* allocating blocks for indirect blocks and direct blocks */ 418 current_block = ext2_new_blocks(inode,goal,&count,err); 419 if (*err) 420 goto failed_out; 421 422 target -= count; 423 /* allocate blocks for indirect blocks */ 424 while (index < indirect_blks && count) { 425 new_blocks[index++] = current_block++; 426 count--; 427 } 428 429 if (count > 0) 430 break; 431 } 432 433 /* save the new block number for the first direct block */ 434 new_blocks[index] = current_block; 435 436 /* total number of blocks allocated for direct blocks */ 437 ret = count; 438 *err = 0; 439 return ret; 440 failed_out: 441 for (i = 0; i <index; i++) 442 ext2_free_blocks(inode, new_blocks[i], 1); 443 if (index) 444 mark_inode_dirty(inode); 445 return ret; 446 } 447 448 /** 449 * ext2_alloc_branch - allocate and set up a chain of blocks. 450 * @inode: owner 451 * @indirect_blks: depth of the chain (number of blocks to allocate) 452 * @blks: number of allocated direct blocks 453 * @goal: preferred place for allocation 454 * @offsets: offsets (in the blocks) to store the pointers to next. 455 * @branch: place to store the chain in. 456 * 457 * This function allocates @num blocks, zeroes out all but the last one, 458 * links them into chain and (if we are synchronous) writes them to disk. 459 * In other words, it prepares a branch that can be spliced onto the 460 * inode. It stores the information about that chain in the branch[], in 461 * the same format as ext2_get_branch() would do. We are calling it after 462 * we had read the existing part of chain and partial points to the last 463 * triple of that (one with zero ->key). Upon the exit we have the same 464 * picture as after the successful ext2_get_block(), except that in one 465 * place chain is disconnected - *branch->p is still zero (we did not 466 * set the last link), but branch->key contains the number that should 467 * be placed into *branch->p to fill that gap. 468 * 469 * If allocation fails we free all blocks we've allocated (and forget 470 * their buffer_heads) and return the error value the from failed 471 * ext2_alloc_block() (normally -ENOSPC). Otherwise we set the chain 472 * as described above and return 0. 473 */ 474 475 static int ext2_alloc_branch(struct inode *inode, 476 int indirect_blks, int *blks, ext2_fsblk_t goal, 477 int *offsets, Indirect *branch) 478 { 479 int blocksize = inode->i_sb->s_blocksize; 480 int i, n = 0; 481 int err = 0; 482 struct buffer_head *bh; 483 int num; 484 ext2_fsblk_t new_blocks[4]; 485 ext2_fsblk_t current_block; 486 487 num = ext2_alloc_blocks(inode, goal, indirect_blks, 488 *blks, new_blocks, &err); 489 if (err) 490 return err; 491 492 branch[0].key = cpu_to_le32(new_blocks[0]); 493 /* 494 * metadata blocks and data blocks are allocated. 495 */ 496 for (n = 1; n <= indirect_blks; n++) { 497 /* 498 * Get buffer_head for parent block, zero it out 499 * and set the pointer to new one, then send 500 * parent to disk. 501 */ 502 bh = sb_getblk(inode->i_sb, new_blocks[n-1]); 503 if (unlikely(!bh)) { 504 err = -ENOMEM; 505 goto failed; 506 } 507 branch[n].bh = bh; 508 lock_buffer(bh); 509 memset(bh->b_data, 0, blocksize); 510 branch[n].p = (__le32 *) bh->b_data + offsets[n]; 511 branch[n].key = cpu_to_le32(new_blocks[n]); 512 *branch[n].p = branch[n].key; 513 if ( n == indirect_blks) { 514 current_block = new_blocks[n]; 515 /* 516 * End of chain, update the last new metablock of 517 * the chain to point to the new allocated 518 * data blocks numbers 519 */ 520 for (i=1; i < num; i++) 521 *(branch[n].p + i) = cpu_to_le32(++current_block); 522 } 523 set_buffer_uptodate(bh); 524 unlock_buffer(bh); 525 mark_buffer_dirty_inode(bh, inode); 526 /* We used to sync bh here if IS_SYNC(inode). 527 * But we now rely upon generic_write_sync() 528 * and b_inode_buffers. But not for directories. 529 */ 530 if (S_ISDIR(inode->i_mode) && IS_DIRSYNC(inode)) 531 sync_dirty_buffer(bh); 532 } 533 *blks = num; 534 return err; 535 536 failed: 537 for (i = 1; i < n; i++) 538 bforget(branch[i].bh); 539 for (i = 0; i < indirect_blks; i++) 540 ext2_free_blocks(inode, new_blocks[i], 1); 541 ext2_free_blocks(inode, new_blocks[i], num); 542 return err; 543 } 544 545 /** 546 * ext2_splice_branch - splice the allocated branch onto inode. 547 * @inode: owner 548 * @block: (logical) number of block we are adding 549 * @where: location of missing link 550 * @num: number of indirect blocks we are adding 551 * @blks: number of direct blocks we are adding 552 * 553 * This function fills the missing link and does all housekeeping needed in 554 * inode (->i_blocks, etc.). In case of success we end up with the full 555 * chain to new block and return 0. 556 */ 557 static void ext2_splice_branch(struct inode *inode, 558 long block, Indirect *where, int num, int blks) 559 { 560 int i; 561 struct ext2_block_alloc_info *block_i; 562 ext2_fsblk_t current_block; 563 564 block_i = EXT2_I(inode)->i_block_alloc_info; 565 566 /* XXX LOCKING probably should have i_meta_lock ?*/ 567 /* That's it */ 568 569 *where->p = where->key; 570 571 /* 572 * Update the host buffer_head or inode to point to more just allocated 573 * direct blocks blocks 574 */ 575 if (num == 0 && blks > 1) { 576 current_block = le32_to_cpu(where->key) + 1; 577 for (i = 1; i < blks; i++) 578 *(where->p + i ) = cpu_to_le32(current_block++); 579 } 580 581 /* 582 * update the most recently allocated logical & physical block 583 * in i_block_alloc_info, to assist find the proper goal block for next 584 * allocation 585 */ 586 if (block_i) { 587 block_i->last_alloc_logical_block = block + blks - 1; 588 block_i->last_alloc_physical_block = 589 le32_to_cpu(where[num].key) + blks - 1; 590 } 591 592 /* We are done with atomic stuff, now do the rest of housekeeping */ 593 594 /* had we spliced it onto indirect block? */ 595 if (where->bh) 596 mark_buffer_dirty_inode(where->bh, inode); 597 598 inode->i_ctime = current_time(inode); 599 mark_inode_dirty(inode); 600 } 601 602 /* 603 * Allocation strategy is simple: if we have to allocate something, we will 604 * have to go the whole way to leaf. So let's do it before attaching anything 605 * to tree, set linkage between the newborn blocks, write them if sync is 606 * required, recheck the path, free and repeat if check fails, otherwise 607 * set the last missing link (that will protect us from any truncate-generated 608 * removals - all blocks on the path are immune now) and possibly force the 609 * write on the parent block. 610 * That has a nice additional property: no special recovery from the failed 611 * allocations is needed - we simply release blocks and do not touch anything 612 * reachable from inode. 613 * 614 * `handle' can be NULL if create == 0. 615 * 616 * return > 0, # of blocks mapped or allocated. 617 * return = 0, if plain lookup failed. 618 * return < 0, error case. 619 */ 620 static int ext2_get_blocks(struct inode *inode, 621 sector_t iblock, unsigned long maxblocks, 622 u32 *bno, bool *new, bool *boundary, 623 int create) 624 { 625 int err; 626 int offsets[4]; 627 Indirect chain[4]; 628 Indirect *partial; 629 ext2_fsblk_t goal; 630 int indirect_blks; 631 int blocks_to_boundary = 0; 632 int depth; 633 struct ext2_inode_info *ei = EXT2_I(inode); 634 int count = 0; 635 ext2_fsblk_t first_block = 0; 636 637 BUG_ON(maxblocks == 0); 638 639 depth = ext2_block_to_path(inode,iblock,offsets,&blocks_to_boundary); 640 641 if (depth == 0) 642 return -EIO; 643 644 partial = ext2_get_branch(inode, depth, offsets, chain, &err); 645 /* Simplest case - block found, no allocation needed */ 646 if (!partial) { 647 first_block = le32_to_cpu(chain[depth - 1].key); 648 count++; 649 /*map more blocks*/ 650 while (count < maxblocks && count <= blocks_to_boundary) { 651 ext2_fsblk_t blk; 652 653 if (!verify_chain(chain, chain + depth - 1)) { 654 /* 655 * Indirect block might be removed by 656 * truncate while we were reading it. 657 * Handling of that case: forget what we've 658 * got now, go to reread. 659 */ 660 err = -EAGAIN; 661 count = 0; 662 partial = chain + depth - 1; 663 break; 664 } 665 blk = le32_to_cpu(*(chain[depth-1].p + count)); 666 if (blk == first_block + count) 667 count++; 668 else 669 break; 670 } 671 if (err != -EAGAIN) 672 goto got_it; 673 } 674 675 /* Next simple case - plain lookup or failed read of indirect block */ 676 if (!create || err == -EIO) 677 goto cleanup; 678 679 mutex_lock(&ei->truncate_mutex); 680 /* 681 * If the indirect block is missing while we are reading 682 * the chain(ext2_get_branch() returns -EAGAIN err), or 683 * if the chain has been changed after we grab the semaphore, 684 * (either because another process truncated this branch, or 685 * another get_block allocated this branch) re-grab the chain to see if 686 * the request block has been allocated or not. 687 * 688 * Since we already block the truncate/other get_block 689 * at this point, we will have the current copy of the chain when we 690 * splice the branch into the tree. 691 */ 692 if (err == -EAGAIN || !verify_chain(chain, partial)) { 693 while (partial > chain) { 694 brelse(partial->bh); 695 partial--; 696 } 697 partial = ext2_get_branch(inode, depth, offsets, chain, &err); 698 if (!partial) { 699 count++; 700 mutex_unlock(&ei->truncate_mutex); 701 goto got_it; 702 } 703 704 if (err) { 705 mutex_unlock(&ei->truncate_mutex); 706 goto cleanup; 707 } 708 } 709 710 /* 711 * Okay, we need to do block allocation. Lazily initialize the block 712 * allocation info here if necessary 713 */ 714 if (S_ISREG(inode->i_mode) && (!ei->i_block_alloc_info)) 715 ext2_init_block_alloc_info(inode); 716 717 goal = ext2_find_goal(inode, iblock, partial); 718 719 /* the number of blocks need to allocate for [d,t]indirect blocks */ 720 indirect_blks = (chain + depth) - partial - 1; 721 /* 722 * Next look up the indirect map to count the total number of 723 * direct blocks to allocate for this branch. 724 */ 725 count = ext2_blks_to_allocate(partial, indirect_blks, 726 maxblocks, blocks_to_boundary); 727 /* 728 * XXX ???? Block out ext2_truncate while we alter the tree 729 */ 730 err = ext2_alloc_branch(inode, indirect_blks, &count, goal, 731 offsets + (partial - chain), partial); 732 733 if (err) { 734 mutex_unlock(&ei->truncate_mutex); 735 goto cleanup; 736 } 737 738 if (IS_DAX(inode)) { 739 /* 740 * We must unmap blocks before zeroing so that writeback cannot 741 * overwrite zeros with stale data from block device page cache. 742 */ 743 clean_bdev_aliases(inode->i_sb->s_bdev, 744 le32_to_cpu(chain[depth-1].key), 745 count); 746 /* 747 * block must be initialised before we put it in the tree 748 * so that it's not found by another thread before it's 749 * initialised 750 */ 751 err = sb_issue_zeroout(inode->i_sb, 752 le32_to_cpu(chain[depth-1].key), count, 753 GFP_NOFS); 754 if (err) { 755 mutex_unlock(&ei->truncate_mutex); 756 goto cleanup; 757 } 758 } 759 *new = true; 760 761 ext2_splice_branch(inode, iblock, partial, indirect_blks, count); 762 mutex_unlock(&ei->truncate_mutex); 763 got_it: 764 if (count > blocks_to_boundary) 765 *boundary = true; 766 err = count; 767 /* Clean up and exit */ 768 partial = chain + depth - 1; /* the whole chain */ 769 cleanup: 770 while (partial > chain) { 771 brelse(partial->bh); 772 partial--; 773 } 774 if (err > 0) 775 *bno = le32_to_cpu(chain[depth-1].key); 776 return err; 777 } 778 779 int ext2_get_block(struct inode *inode, sector_t iblock, 780 struct buffer_head *bh_result, int create) 781 { 782 unsigned max_blocks = bh_result->b_size >> inode->i_blkbits; 783 bool new = false, boundary = false; 784 u32 bno; 785 int ret; 786 787 ret = ext2_get_blocks(inode, iblock, max_blocks, &bno, &new, &boundary, 788 create); 789 if (ret <= 0) 790 return ret; 791 792 map_bh(bh_result, inode->i_sb, bno); 793 bh_result->b_size = (ret << inode->i_blkbits); 794 if (new) 795 set_buffer_new(bh_result); 796 if (boundary) 797 set_buffer_boundary(bh_result); 798 return 0; 799 800 } 801 802 static int ext2_iomap_begin(struct inode *inode, loff_t offset, loff_t length, 803 unsigned flags, struct iomap *iomap, struct iomap *srcmap) 804 { 805 unsigned int blkbits = inode->i_blkbits; 806 unsigned long first_block = offset >> blkbits; 807 unsigned long max_blocks = (length + (1 << blkbits) - 1) >> blkbits; 808 struct ext2_sb_info *sbi = EXT2_SB(inode->i_sb); 809 bool new = false, boundary = false; 810 u32 bno; 811 int ret; 812 813 ret = ext2_get_blocks(inode, first_block, max_blocks, 814 &bno, &new, &boundary, flags & IOMAP_WRITE); 815 if (ret < 0) 816 return ret; 817 818 iomap->flags = 0; 819 iomap->offset = (u64)first_block << blkbits; 820 if (flags & IOMAP_DAX) 821 iomap->dax_dev = sbi->s_daxdev; 822 else 823 iomap->bdev = inode->i_sb->s_bdev; 824 825 if (ret == 0) { 826 iomap->type = IOMAP_HOLE; 827 iomap->addr = IOMAP_NULL_ADDR; 828 iomap->length = 1 << blkbits; 829 } else { 830 iomap->type = IOMAP_MAPPED; 831 iomap->addr = (u64)bno << blkbits; 832 if (flags & IOMAP_DAX) 833 iomap->addr += sbi->s_dax_part_off; 834 iomap->length = (u64)ret << blkbits; 835 iomap->flags |= IOMAP_F_MERGED; 836 } 837 838 if (new) 839 iomap->flags |= IOMAP_F_NEW; 840 return 0; 841 } 842 843 static int 844 ext2_iomap_end(struct inode *inode, loff_t offset, loff_t length, 845 ssize_t written, unsigned flags, struct iomap *iomap) 846 { 847 if (iomap->type == IOMAP_MAPPED && 848 written < length && 849 (flags & IOMAP_WRITE)) 850 ext2_write_failed(inode->i_mapping, offset + length); 851 return 0; 852 } 853 854 const struct iomap_ops ext2_iomap_ops = { 855 .iomap_begin = ext2_iomap_begin, 856 .iomap_end = ext2_iomap_end, 857 }; 858 859 int ext2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, 860 u64 start, u64 len) 861 { 862 int ret; 863 864 inode_lock(inode); 865 len = min_t(u64, len, i_size_read(inode)); 866 ret = iomap_fiemap(inode, fieinfo, start, len, &ext2_iomap_ops); 867 inode_unlock(inode); 868 869 return ret; 870 } 871 872 static int ext2_writepage(struct page *page, struct writeback_control *wbc) 873 { 874 return block_write_full_page(page, ext2_get_block, wbc); 875 } 876 877 static int ext2_read_folio(struct file *file, struct folio *folio) 878 { 879 return mpage_read_folio(folio, ext2_get_block); 880 } 881 882 static void ext2_readahead(struct readahead_control *rac) 883 { 884 mpage_readahead(rac, ext2_get_block); 885 } 886 887 static int 888 ext2_write_begin(struct file *file, struct address_space *mapping, 889 loff_t pos, unsigned len, struct page **pagep, void **fsdata) 890 { 891 int ret; 892 893 ret = block_write_begin(mapping, pos, len, pagep, ext2_get_block); 894 if (ret < 0) 895 ext2_write_failed(mapping, pos + len); 896 return ret; 897 } 898 899 static int ext2_write_end(struct file *file, struct address_space *mapping, 900 loff_t pos, unsigned len, unsigned copied, 901 struct page *page, void *fsdata) 902 { 903 int ret; 904 905 ret = generic_write_end(file, mapping, pos, len, copied, page, fsdata); 906 if (ret < len) 907 ext2_write_failed(mapping, pos + len); 908 return ret; 909 } 910 911 static int 912 ext2_nobh_write_begin(struct file *file, struct address_space *mapping, 913 loff_t pos, unsigned len, struct page **pagep, void **fsdata) 914 { 915 int ret; 916 917 ret = nobh_write_begin(mapping, pos, len, pagep, fsdata, 918 ext2_get_block); 919 if (ret < 0) 920 ext2_write_failed(mapping, pos + len); 921 return ret; 922 } 923 924 static int ext2_nobh_writepage(struct page *page, 925 struct writeback_control *wbc) 926 { 927 return nobh_writepage(page, ext2_get_block, wbc); 928 } 929 930 static sector_t ext2_bmap(struct address_space *mapping, sector_t block) 931 { 932 return generic_block_bmap(mapping,block,ext2_get_block); 933 } 934 935 static ssize_t 936 ext2_direct_IO(struct kiocb *iocb, struct iov_iter *iter) 937 { 938 struct file *file = iocb->ki_filp; 939 struct address_space *mapping = file->f_mapping; 940 struct inode *inode = mapping->host; 941 size_t count = iov_iter_count(iter); 942 loff_t offset = iocb->ki_pos; 943 ssize_t ret; 944 945 ret = blockdev_direct_IO(iocb, inode, iter, ext2_get_block); 946 if (ret < 0 && iov_iter_rw(iter) == WRITE) 947 ext2_write_failed(mapping, offset + count); 948 return ret; 949 } 950 951 static int 952 ext2_writepages(struct address_space *mapping, struct writeback_control *wbc) 953 { 954 return mpage_writepages(mapping, wbc, ext2_get_block); 955 } 956 957 static int 958 ext2_dax_writepages(struct address_space *mapping, struct writeback_control *wbc) 959 { 960 struct ext2_sb_info *sbi = EXT2_SB(mapping->host->i_sb); 961 962 return dax_writeback_mapping_range(mapping, sbi->s_daxdev, wbc); 963 } 964 965 const struct address_space_operations ext2_aops = { 966 .dirty_folio = block_dirty_folio, 967 .invalidate_folio = block_invalidate_folio, 968 .read_folio = ext2_read_folio, 969 .readahead = ext2_readahead, 970 .writepage = ext2_writepage, 971 .write_begin = ext2_write_begin, 972 .write_end = ext2_write_end, 973 .bmap = ext2_bmap, 974 .direct_IO = ext2_direct_IO, 975 .writepages = ext2_writepages, 976 .migratepage = buffer_migrate_page, 977 .is_partially_uptodate = block_is_partially_uptodate, 978 .error_remove_page = generic_error_remove_page, 979 }; 980 981 const struct address_space_operations ext2_nobh_aops = { 982 .dirty_folio = block_dirty_folio, 983 .invalidate_folio = block_invalidate_folio, 984 .read_folio = ext2_read_folio, 985 .readahead = ext2_readahead, 986 .writepage = ext2_nobh_writepage, 987 .write_begin = ext2_nobh_write_begin, 988 .write_end = nobh_write_end, 989 .bmap = ext2_bmap, 990 .direct_IO = ext2_direct_IO, 991 .writepages = ext2_writepages, 992 .migratepage = buffer_migrate_page, 993 .error_remove_page = generic_error_remove_page, 994 }; 995 996 static const struct address_space_operations ext2_dax_aops = { 997 .writepages = ext2_dax_writepages, 998 .direct_IO = noop_direct_IO, 999 .dirty_folio = noop_dirty_folio, 1000 }; 1001 1002 /* 1003 * Probably it should be a library function... search for first non-zero word 1004 * or memcmp with zero_page, whatever is better for particular architecture. 1005 * Linus? 1006 */ 1007 static inline int all_zeroes(__le32 *p, __le32 *q) 1008 { 1009 while (p < q) 1010 if (*p++) 1011 return 0; 1012 return 1; 1013 } 1014 1015 /** 1016 * ext2_find_shared - find the indirect blocks for partial truncation. 1017 * @inode: inode in question 1018 * @depth: depth of the affected branch 1019 * @offsets: offsets of pointers in that branch (see ext2_block_to_path) 1020 * @chain: place to store the pointers to partial indirect blocks 1021 * @top: place to the (detached) top of branch 1022 * 1023 * This is a helper function used by ext2_truncate(). 1024 * 1025 * When we do truncate() we may have to clean the ends of several indirect 1026 * blocks but leave the blocks themselves alive. Block is partially 1027 * truncated if some data below the new i_size is referred from it (and 1028 * it is on the path to the first completely truncated data block, indeed). 1029 * We have to free the top of that path along with everything to the right 1030 * of the path. Since no allocation past the truncation point is possible 1031 * until ext2_truncate() finishes, we may safely do the latter, but top 1032 * of branch may require special attention - pageout below the truncation 1033 * point might try to populate it. 1034 * 1035 * We atomically detach the top of branch from the tree, store the block 1036 * number of its root in *@top, pointers to buffer_heads of partially 1037 * truncated blocks - in @chain[].bh and pointers to their last elements 1038 * that should not be removed - in @chain[].p. Return value is the pointer 1039 * to last filled element of @chain. 1040 * 1041 * The work left to caller to do the actual freeing of subtrees: 1042 * a) free the subtree starting from *@top 1043 * b) free the subtrees whose roots are stored in 1044 * (@chain[i].p+1 .. end of @chain[i].bh->b_data) 1045 * c) free the subtrees growing from the inode past the @chain[0].p 1046 * (no partially truncated stuff there). 1047 */ 1048 1049 static Indirect *ext2_find_shared(struct inode *inode, 1050 int depth, 1051 int offsets[4], 1052 Indirect chain[4], 1053 __le32 *top) 1054 { 1055 Indirect *partial, *p; 1056 int k, err; 1057 1058 *top = 0; 1059 for (k = depth; k > 1 && !offsets[k-1]; k--) 1060 ; 1061 partial = ext2_get_branch(inode, k, offsets, chain, &err); 1062 if (!partial) 1063 partial = chain + k-1; 1064 /* 1065 * If the branch acquired continuation since we've looked at it - 1066 * fine, it should all survive and (new) top doesn't belong to us. 1067 */ 1068 write_lock(&EXT2_I(inode)->i_meta_lock); 1069 if (!partial->key && *partial->p) { 1070 write_unlock(&EXT2_I(inode)->i_meta_lock); 1071 goto no_top; 1072 } 1073 for (p=partial; p>chain && all_zeroes((__le32*)p->bh->b_data,p->p); p--) 1074 ; 1075 /* 1076 * OK, we've found the last block that must survive. The rest of our 1077 * branch should be detached before unlocking. However, if that rest 1078 * of branch is all ours and does not grow immediately from the inode 1079 * it's easier to cheat and just decrement partial->p. 1080 */ 1081 if (p == chain + k - 1 && p > chain) { 1082 p->p--; 1083 } else { 1084 *top = *p->p; 1085 *p->p = 0; 1086 } 1087 write_unlock(&EXT2_I(inode)->i_meta_lock); 1088 1089 while(partial > p) 1090 { 1091 brelse(partial->bh); 1092 partial--; 1093 } 1094 no_top: 1095 return partial; 1096 } 1097 1098 /** 1099 * ext2_free_data - free a list of data blocks 1100 * @inode: inode we are dealing with 1101 * @p: array of block numbers 1102 * @q: points immediately past the end of array 1103 * 1104 * We are freeing all blocks referred from that array (numbers are 1105 * stored as little-endian 32-bit) and updating @inode->i_blocks 1106 * appropriately. 1107 */ 1108 static inline void ext2_free_data(struct inode *inode, __le32 *p, __le32 *q) 1109 { 1110 unsigned long block_to_free = 0, count = 0; 1111 unsigned long nr; 1112 1113 for ( ; p < q ; p++) { 1114 nr = le32_to_cpu(*p); 1115 if (nr) { 1116 *p = 0; 1117 /* accumulate blocks to free if they're contiguous */ 1118 if (count == 0) 1119 goto free_this; 1120 else if (block_to_free == nr - count) 1121 count++; 1122 else { 1123 ext2_free_blocks (inode, block_to_free, count); 1124 mark_inode_dirty(inode); 1125 free_this: 1126 block_to_free = nr; 1127 count = 1; 1128 } 1129 } 1130 } 1131 if (count > 0) { 1132 ext2_free_blocks (inode, block_to_free, count); 1133 mark_inode_dirty(inode); 1134 } 1135 } 1136 1137 /** 1138 * ext2_free_branches - free an array of branches 1139 * @inode: inode we are dealing with 1140 * @p: array of block numbers 1141 * @q: pointer immediately past the end of array 1142 * @depth: depth of the branches to free 1143 * 1144 * We are freeing all blocks referred from these branches (numbers are 1145 * stored as little-endian 32-bit) and updating @inode->i_blocks 1146 * appropriately. 1147 */ 1148 static void ext2_free_branches(struct inode *inode, __le32 *p, __le32 *q, int depth) 1149 { 1150 struct buffer_head * bh; 1151 unsigned long nr; 1152 1153 if (depth--) { 1154 int addr_per_block = EXT2_ADDR_PER_BLOCK(inode->i_sb); 1155 for ( ; p < q ; p++) { 1156 nr = le32_to_cpu(*p); 1157 if (!nr) 1158 continue; 1159 *p = 0; 1160 bh = sb_bread(inode->i_sb, nr); 1161 /* 1162 * A read failure? Report error and clear slot 1163 * (should be rare). 1164 */ 1165 if (!bh) { 1166 ext2_error(inode->i_sb, "ext2_free_branches", 1167 "Read failure, inode=%ld, block=%ld", 1168 inode->i_ino, nr); 1169 continue; 1170 } 1171 ext2_free_branches(inode, 1172 (__le32*)bh->b_data, 1173 (__le32*)bh->b_data + addr_per_block, 1174 depth); 1175 bforget(bh); 1176 ext2_free_blocks(inode, nr, 1); 1177 mark_inode_dirty(inode); 1178 } 1179 } else 1180 ext2_free_data(inode, p, q); 1181 } 1182 1183 /* mapping->invalidate_lock must be held when calling this function */ 1184 static void __ext2_truncate_blocks(struct inode *inode, loff_t offset) 1185 { 1186 __le32 *i_data = EXT2_I(inode)->i_data; 1187 struct ext2_inode_info *ei = EXT2_I(inode); 1188 int addr_per_block = EXT2_ADDR_PER_BLOCK(inode->i_sb); 1189 int offsets[4]; 1190 Indirect chain[4]; 1191 Indirect *partial; 1192 __le32 nr = 0; 1193 int n; 1194 long iblock; 1195 unsigned blocksize; 1196 blocksize = inode->i_sb->s_blocksize; 1197 iblock = (offset + blocksize-1) >> EXT2_BLOCK_SIZE_BITS(inode->i_sb); 1198 1199 #ifdef CONFIG_FS_DAX 1200 WARN_ON(!rwsem_is_locked(&inode->i_mapping->invalidate_lock)); 1201 #endif 1202 1203 n = ext2_block_to_path(inode, iblock, offsets, NULL); 1204 if (n == 0) 1205 return; 1206 1207 /* 1208 * From here we block out all ext2_get_block() callers who want to 1209 * modify the block allocation tree. 1210 */ 1211 mutex_lock(&ei->truncate_mutex); 1212 1213 if (n == 1) { 1214 ext2_free_data(inode, i_data+offsets[0], 1215 i_data + EXT2_NDIR_BLOCKS); 1216 goto do_indirects; 1217 } 1218 1219 partial = ext2_find_shared(inode, n, offsets, chain, &nr); 1220 /* Kill the top of shared branch (already detached) */ 1221 if (nr) { 1222 if (partial == chain) 1223 mark_inode_dirty(inode); 1224 else 1225 mark_buffer_dirty_inode(partial->bh, inode); 1226 ext2_free_branches(inode, &nr, &nr+1, (chain+n-1) - partial); 1227 } 1228 /* Clear the ends of indirect blocks on the shared branch */ 1229 while (partial > chain) { 1230 ext2_free_branches(inode, 1231 partial->p + 1, 1232 (__le32*)partial->bh->b_data+addr_per_block, 1233 (chain+n-1) - partial); 1234 mark_buffer_dirty_inode(partial->bh, inode); 1235 brelse (partial->bh); 1236 partial--; 1237 } 1238 do_indirects: 1239 /* Kill the remaining (whole) subtrees */ 1240 switch (offsets[0]) { 1241 default: 1242 nr = i_data[EXT2_IND_BLOCK]; 1243 if (nr) { 1244 i_data[EXT2_IND_BLOCK] = 0; 1245 mark_inode_dirty(inode); 1246 ext2_free_branches(inode, &nr, &nr+1, 1); 1247 } 1248 fallthrough; 1249 case EXT2_IND_BLOCK: 1250 nr = i_data[EXT2_DIND_BLOCK]; 1251 if (nr) { 1252 i_data[EXT2_DIND_BLOCK] = 0; 1253 mark_inode_dirty(inode); 1254 ext2_free_branches(inode, &nr, &nr+1, 2); 1255 } 1256 fallthrough; 1257 case EXT2_DIND_BLOCK: 1258 nr = i_data[EXT2_TIND_BLOCK]; 1259 if (nr) { 1260 i_data[EXT2_TIND_BLOCK] = 0; 1261 mark_inode_dirty(inode); 1262 ext2_free_branches(inode, &nr, &nr+1, 3); 1263 } 1264 break; 1265 case EXT2_TIND_BLOCK: 1266 ; 1267 } 1268 1269 ext2_discard_reservation(inode); 1270 1271 mutex_unlock(&ei->truncate_mutex); 1272 } 1273 1274 static void ext2_truncate_blocks(struct inode *inode, loff_t offset) 1275 { 1276 if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || 1277 S_ISLNK(inode->i_mode))) 1278 return; 1279 if (ext2_inode_is_fast_symlink(inode)) 1280 return; 1281 1282 filemap_invalidate_lock(inode->i_mapping); 1283 __ext2_truncate_blocks(inode, offset); 1284 filemap_invalidate_unlock(inode->i_mapping); 1285 } 1286 1287 static int ext2_setsize(struct inode *inode, loff_t newsize) 1288 { 1289 int error; 1290 1291 if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || 1292 S_ISLNK(inode->i_mode))) 1293 return -EINVAL; 1294 if (ext2_inode_is_fast_symlink(inode)) 1295 return -EINVAL; 1296 if (IS_APPEND(inode) || IS_IMMUTABLE(inode)) 1297 return -EPERM; 1298 1299 inode_dio_wait(inode); 1300 1301 if (IS_DAX(inode)) { 1302 error = dax_zero_range(inode, newsize, 1303 PAGE_ALIGN(newsize) - newsize, NULL, 1304 &ext2_iomap_ops); 1305 } else if (test_opt(inode->i_sb, NOBH)) 1306 error = nobh_truncate_page(inode->i_mapping, 1307 newsize, ext2_get_block); 1308 else 1309 error = block_truncate_page(inode->i_mapping, 1310 newsize, ext2_get_block); 1311 if (error) 1312 return error; 1313 1314 filemap_invalidate_lock(inode->i_mapping); 1315 truncate_setsize(inode, newsize); 1316 __ext2_truncate_blocks(inode, newsize); 1317 filemap_invalidate_unlock(inode->i_mapping); 1318 1319 inode->i_mtime = inode->i_ctime = current_time(inode); 1320 if (inode_needs_sync(inode)) { 1321 sync_mapping_buffers(inode->i_mapping); 1322 sync_inode_metadata(inode, 1); 1323 } else { 1324 mark_inode_dirty(inode); 1325 } 1326 1327 return 0; 1328 } 1329 1330 static struct ext2_inode *ext2_get_inode(struct super_block *sb, ino_t ino, 1331 struct buffer_head **p) 1332 { 1333 struct buffer_head * bh; 1334 unsigned long block_group; 1335 unsigned long block; 1336 unsigned long offset; 1337 struct ext2_group_desc * gdp; 1338 1339 *p = NULL; 1340 if ((ino != EXT2_ROOT_INO && ino < EXT2_FIRST_INO(sb)) || 1341 ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count)) 1342 goto Einval; 1343 1344 block_group = (ino - 1) / EXT2_INODES_PER_GROUP(sb); 1345 gdp = ext2_get_group_desc(sb, block_group, NULL); 1346 if (!gdp) 1347 goto Egdp; 1348 /* 1349 * Figure out the offset within the block group inode table 1350 */ 1351 offset = ((ino - 1) % EXT2_INODES_PER_GROUP(sb)) * EXT2_INODE_SIZE(sb); 1352 block = le32_to_cpu(gdp->bg_inode_table) + 1353 (offset >> EXT2_BLOCK_SIZE_BITS(sb)); 1354 if (!(bh = sb_bread(sb, block))) 1355 goto Eio; 1356 1357 *p = bh; 1358 offset &= (EXT2_BLOCK_SIZE(sb) - 1); 1359 return (struct ext2_inode *) (bh->b_data + offset); 1360 1361 Einval: 1362 ext2_error(sb, "ext2_get_inode", "bad inode number: %lu", 1363 (unsigned long) ino); 1364 return ERR_PTR(-EINVAL); 1365 Eio: 1366 ext2_error(sb, "ext2_get_inode", 1367 "unable to read inode block - inode=%lu, block=%lu", 1368 (unsigned long) ino, block); 1369 Egdp: 1370 return ERR_PTR(-EIO); 1371 } 1372 1373 void ext2_set_inode_flags(struct inode *inode) 1374 { 1375 unsigned int flags = EXT2_I(inode)->i_flags; 1376 1377 inode->i_flags &= ~(S_SYNC | S_APPEND | S_IMMUTABLE | S_NOATIME | 1378 S_DIRSYNC | S_DAX); 1379 if (flags & EXT2_SYNC_FL) 1380 inode->i_flags |= S_SYNC; 1381 if (flags & EXT2_APPEND_FL) 1382 inode->i_flags |= S_APPEND; 1383 if (flags & EXT2_IMMUTABLE_FL) 1384 inode->i_flags |= S_IMMUTABLE; 1385 if (flags & EXT2_NOATIME_FL) 1386 inode->i_flags |= S_NOATIME; 1387 if (flags & EXT2_DIRSYNC_FL) 1388 inode->i_flags |= S_DIRSYNC; 1389 if (test_opt(inode->i_sb, DAX) && S_ISREG(inode->i_mode)) 1390 inode->i_flags |= S_DAX; 1391 } 1392 1393 void ext2_set_file_ops(struct inode *inode) 1394 { 1395 inode->i_op = &ext2_file_inode_operations; 1396 inode->i_fop = &ext2_file_operations; 1397 if (IS_DAX(inode)) 1398 inode->i_mapping->a_ops = &ext2_dax_aops; 1399 else if (test_opt(inode->i_sb, NOBH)) 1400 inode->i_mapping->a_ops = &ext2_nobh_aops; 1401 else 1402 inode->i_mapping->a_ops = &ext2_aops; 1403 } 1404 1405 struct inode *ext2_iget (struct super_block *sb, unsigned long ino) 1406 { 1407 struct ext2_inode_info *ei; 1408 struct buffer_head * bh = NULL; 1409 struct ext2_inode *raw_inode; 1410 struct inode *inode; 1411 long ret = -EIO; 1412 int n; 1413 uid_t i_uid; 1414 gid_t i_gid; 1415 1416 inode = iget_locked(sb, ino); 1417 if (!inode) 1418 return ERR_PTR(-ENOMEM); 1419 if (!(inode->i_state & I_NEW)) 1420 return inode; 1421 1422 ei = EXT2_I(inode); 1423 ei->i_block_alloc_info = NULL; 1424 1425 raw_inode = ext2_get_inode(inode->i_sb, ino, &bh); 1426 if (IS_ERR(raw_inode)) { 1427 ret = PTR_ERR(raw_inode); 1428 goto bad_inode; 1429 } 1430 1431 inode->i_mode = le16_to_cpu(raw_inode->i_mode); 1432 i_uid = (uid_t)le16_to_cpu(raw_inode->i_uid_low); 1433 i_gid = (gid_t)le16_to_cpu(raw_inode->i_gid_low); 1434 if (!(test_opt (inode->i_sb, NO_UID32))) { 1435 i_uid |= le16_to_cpu(raw_inode->i_uid_high) << 16; 1436 i_gid |= le16_to_cpu(raw_inode->i_gid_high) << 16; 1437 } 1438 i_uid_write(inode, i_uid); 1439 i_gid_write(inode, i_gid); 1440 set_nlink(inode, le16_to_cpu(raw_inode->i_links_count)); 1441 inode->i_size = le32_to_cpu(raw_inode->i_size); 1442 inode->i_atime.tv_sec = (signed)le32_to_cpu(raw_inode->i_atime); 1443 inode->i_ctime.tv_sec = (signed)le32_to_cpu(raw_inode->i_ctime); 1444 inode->i_mtime.tv_sec = (signed)le32_to_cpu(raw_inode->i_mtime); 1445 inode->i_atime.tv_nsec = inode->i_mtime.tv_nsec = inode->i_ctime.tv_nsec = 0; 1446 ei->i_dtime = le32_to_cpu(raw_inode->i_dtime); 1447 /* We now have enough fields to check if the inode was active or not. 1448 * This is needed because nfsd might try to access dead inodes 1449 * the test is that same one that e2fsck uses 1450 * NeilBrown 1999oct15 1451 */ 1452 if (inode->i_nlink == 0 && (inode->i_mode == 0 || ei->i_dtime)) { 1453 /* this inode is deleted */ 1454 ret = -ESTALE; 1455 goto bad_inode; 1456 } 1457 inode->i_blocks = le32_to_cpu(raw_inode->i_blocks); 1458 ei->i_flags = le32_to_cpu(raw_inode->i_flags); 1459 ext2_set_inode_flags(inode); 1460 ei->i_faddr = le32_to_cpu(raw_inode->i_faddr); 1461 ei->i_frag_no = raw_inode->i_frag; 1462 ei->i_frag_size = raw_inode->i_fsize; 1463 ei->i_file_acl = le32_to_cpu(raw_inode->i_file_acl); 1464 ei->i_dir_acl = 0; 1465 1466 if (ei->i_file_acl && 1467 !ext2_data_block_valid(EXT2_SB(sb), ei->i_file_acl, 1)) { 1468 ext2_error(sb, "ext2_iget", "bad extended attribute block %u", 1469 ei->i_file_acl); 1470 ret = -EFSCORRUPTED; 1471 goto bad_inode; 1472 } 1473 1474 if (S_ISREG(inode->i_mode)) 1475 inode->i_size |= ((__u64)le32_to_cpu(raw_inode->i_size_high)) << 32; 1476 else 1477 ei->i_dir_acl = le32_to_cpu(raw_inode->i_dir_acl); 1478 if (i_size_read(inode) < 0) { 1479 ret = -EFSCORRUPTED; 1480 goto bad_inode; 1481 } 1482 ei->i_dtime = 0; 1483 inode->i_generation = le32_to_cpu(raw_inode->i_generation); 1484 ei->i_state = 0; 1485 ei->i_block_group = (ino - 1) / EXT2_INODES_PER_GROUP(inode->i_sb); 1486 ei->i_dir_start_lookup = 0; 1487 1488 /* 1489 * NOTE! The in-memory inode i_data array is in little-endian order 1490 * even on big-endian machines: we do NOT byteswap the block numbers! 1491 */ 1492 for (n = 0; n < EXT2_N_BLOCKS; n++) 1493 ei->i_data[n] = raw_inode->i_block[n]; 1494 1495 if (S_ISREG(inode->i_mode)) { 1496 ext2_set_file_ops(inode); 1497 } else if (S_ISDIR(inode->i_mode)) { 1498 inode->i_op = &ext2_dir_inode_operations; 1499 inode->i_fop = &ext2_dir_operations; 1500 if (test_opt(inode->i_sb, NOBH)) 1501 inode->i_mapping->a_ops = &ext2_nobh_aops; 1502 else 1503 inode->i_mapping->a_ops = &ext2_aops; 1504 } else if (S_ISLNK(inode->i_mode)) { 1505 if (ext2_inode_is_fast_symlink(inode)) { 1506 inode->i_link = (char *)ei->i_data; 1507 inode->i_op = &ext2_fast_symlink_inode_operations; 1508 nd_terminate_link(ei->i_data, inode->i_size, 1509 sizeof(ei->i_data) - 1); 1510 } else { 1511 inode->i_op = &ext2_symlink_inode_operations; 1512 inode_nohighmem(inode); 1513 if (test_opt(inode->i_sb, NOBH)) 1514 inode->i_mapping->a_ops = &ext2_nobh_aops; 1515 else 1516 inode->i_mapping->a_ops = &ext2_aops; 1517 } 1518 } else { 1519 inode->i_op = &ext2_special_inode_operations; 1520 if (raw_inode->i_block[0]) 1521 init_special_inode(inode, inode->i_mode, 1522 old_decode_dev(le32_to_cpu(raw_inode->i_block[0]))); 1523 else 1524 init_special_inode(inode, inode->i_mode, 1525 new_decode_dev(le32_to_cpu(raw_inode->i_block[1]))); 1526 } 1527 brelse (bh); 1528 unlock_new_inode(inode); 1529 return inode; 1530 1531 bad_inode: 1532 brelse(bh); 1533 iget_failed(inode); 1534 return ERR_PTR(ret); 1535 } 1536 1537 static int __ext2_write_inode(struct inode *inode, int do_sync) 1538 { 1539 struct ext2_inode_info *ei = EXT2_I(inode); 1540 struct super_block *sb = inode->i_sb; 1541 ino_t ino = inode->i_ino; 1542 uid_t uid = i_uid_read(inode); 1543 gid_t gid = i_gid_read(inode); 1544 struct buffer_head * bh; 1545 struct ext2_inode * raw_inode = ext2_get_inode(sb, ino, &bh); 1546 int n; 1547 int err = 0; 1548 1549 if (IS_ERR(raw_inode)) 1550 return -EIO; 1551 1552 /* For fields not tracking in the in-memory inode, 1553 * initialise them to zero for new inodes. */ 1554 if (ei->i_state & EXT2_STATE_NEW) 1555 memset(raw_inode, 0, EXT2_SB(sb)->s_inode_size); 1556 1557 raw_inode->i_mode = cpu_to_le16(inode->i_mode); 1558 if (!(test_opt(sb, NO_UID32))) { 1559 raw_inode->i_uid_low = cpu_to_le16(low_16_bits(uid)); 1560 raw_inode->i_gid_low = cpu_to_le16(low_16_bits(gid)); 1561 /* 1562 * Fix up interoperability with old kernels. Otherwise, old inodes get 1563 * re-used with the upper 16 bits of the uid/gid intact 1564 */ 1565 if (!ei->i_dtime) { 1566 raw_inode->i_uid_high = cpu_to_le16(high_16_bits(uid)); 1567 raw_inode->i_gid_high = cpu_to_le16(high_16_bits(gid)); 1568 } else { 1569 raw_inode->i_uid_high = 0; 1570 raw_inode->i_gid_high = 0; 1571 } 1572 } else { 1573 raw_inode->i_uid_low = cpu_to_le16(fs_high2lowuid(uid)); 1574 raw_inode->i_gid_low = cpu_to_le16(fs_high2lowgid(gid)); 1575 raw_inode->i_uid_high = 0; 1576 raw_inode->i_gid_high = 0; 1577 } 1578 raw_inode->i_links_count = cpu_to_le16(inode->i_nlink); 1579 raw_inode->i_size = cpu_to_le32(inode->i_size); 1580 raw_inode->i_atime = cpu_to_le32(inode->i_atime.tv_sec); 1581 raw_inode->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec); 1582 raw_inode->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec); 1583 1584 raw_inode->i_blocks = cpu_to_le32(inode->i_blocks); 1585 raw_inode->i_dtime = cpu_to_le32(ei->i_dtime); 1586 raw_inode->i_flags = cpu_to_le32(ei->i_flags); 1587 raw_inode->i_faddr = cpu_to_le32(ei->i_faddr); 1588 raw_inode->i_frag = ei->i_frag_no; 1589 raw_inode->i_fsize = ei->i_frag_size; 1590 raw_inode->i_file_acl = cpu_to_le32(ei->i_file_acl); 1591 if (!S_ISREG(inode->i_mode)) 1592 raw_inode->i_dir_acl = cpu_to_le32(ei->i_dir_acl); 1593 else { 1594 raw_inode->i_size_high = cpu_to_le32(inode->i_size >> 32); 1595 if (inode->i_size > 0x7fffffffULL) { 1596 if (!EXT2_HAS_RO_COMPAT_FEATURE(sb, 1597 EXT2_FEATURE_RO_COMPAT_LARGE_FILE) || 1598 EXT2_SB(sb)->s_es->s_rev_level == 1599 cpu_to_le32(EXT2_GOOD_OLD_REV)) { 1600 /* If this is the first large file 1601 * created, add a flag to the superblock. 1602 */ 1603 spin_lock(&EXT2_SB(sb)->s_lock); 1604 ext2_update_dynamic_rev(sb); 1605 EXT2_SET_RO_COMPAT_FEATURE(sb, 1606 EXT2_FEATURE_RO_COMPAT_LARGE_FILE); 1607 spin_unlock(&EXT2_SB(sb)->s_lock); 1608 ext2_sync_super(sb, EXT2_SB(sb)->s_es, 1); 1609 } 1610 } 1611 } 1612 1613 raw_inode->i_generation = cpu_to_le32(inode->i_generation); 1614 if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) { 1615 if (old_valid_dev(inode->i_rdev)) { 1616 raw_inode->i_block[0] = 1617 cpu_to_le32(old_encode_dev(inode->i_rdev)); 1618 raw_inode->i_block[1] = 0; 1619 } else { 1620 raw_inode->i_block[0] = 0; 1621 raw_inode->i_block[1] = 1622 cpu_to_le32(new_encode_dev(inode->i_rdev)); 1623 raw_inode->i_block[2] = 0; 1624 } 1625 } else for (n = 0; n < EXT2_N_BLOCKS; n++) 1626 raw_inode->i_block[n] = ei->i_data[n]; 1627 mark_buffer_dirty(bh); 1628 if (do_sync) { 1629 sync_dirty_buffer(bh); 1630 if (buffer_req(bh) && !buffer_uptodate(bh)) { 1631 printk ("IO error syncing ext2 inode [%s:%08lx]\n", 1632 sb->s_id, (unsigned long) ino); 1633 err = -EIO; 1634 } 1635 } 1636 ei->i_state &= ~EXT2_STATE_NEW; 1637 brelse (bh); 1638 return err; 1639 } 1640 1641 int ext2_write_inode(struct inode *inode, struct writeback_control *wbc) 1642 { 1643 return __ext2_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL); 1644 } 1645 1646 int ext2_getattr(struct user_namespace *mnt_userns, const struct path *path, 1647 struct kstat *stat, u32 request_mask, unsigned int query_flags) 1648 { 1649 struct inode *inode = d_inode(path->dentry); 1650 struct ext2_inode_info *ei = EXT2_I(inode); 1651 unsigned int flags; 1652 1653 flags = ei->i_flags & EXT2_FL_USER_VISIBLE; 1654 if (flags & EXT2_APPEND_FL) 1655 stat->attributes |= STATX_ATTR_APPEND; 1656 if (flags & EXT2_COMPR_FL) 1657 stat->attributes |= STATX_ATTR_COMPRESSED; 1658 if (flags & EXT2_IMMUTABLE_FL) 1659 stat->attributes |= STATX_ATTR_IMMUTABLE; 1660 if (flags & EXT2_NODUMP_FL) 1661 stat->attributes |= STATX_ATTR_NODUMP; 1662 stat->attributes_mask |= (STATX_ATTR_APPEND | 1663 STATX_ATTR_COMPRESSED | 1664 STATX_ATTR_ENCRYPTED | 1665 STATX_ATTR_IMMUTABLE | 1666 STATX_ATTR_NODUMP); 1667 1668 generic_fillattr(&init_user_ns, inode, stat); 1669 return 0; 1670 } 1671 1672 int ext2_setattr(struct user_namespace *mnt_userns, struct dentry *dentry, 1673 struct iattr *iattr) 1674 { 1675 struct inode *inode = d_inode(dentry); 1676 int error; 1677 1678 error = setattr_prepare(&init_user_ns, dentry, iattr); 1679 if (error) 1680 return error; 1681 1682 if (is_quota_modification(inode, iattr)) { 1683 error = dquot_initialize(inode); 1684 if (error) 1685 return error; 1686 } 1687 if ((iattr->ia_valid & ATTR_UID && !uid_eq(iattr->ia_uid, inode->i_uid)) || 1688 (iattr->ia_valid & ATTR_GID && !gid_eq(iattr->ia_gid, inode->i_gid))) { 1689 error = dquot_transfer(inode, iattr); 1690 if (error) 1691 return error; 1692 } 1693 if (iattr->ia_valid & ATTR_SIZE && iattr->ia_size != inode->i_size) { 1694 error = ext2_setsize(inode, iattr->ia_size); 1695 if (error) 1696 return error; 1697 } 1698 setattr_copy(&init_user_ns, inode, iattr); 1699 if (iattr->ia_valid & ATTR_MODE) 1700 error = posix_acl_chmod(&init_user_ns, inode, inode->i_mode); 1701 mark_inode_dirty(inode); 1702 1703 return error; 1704 } 1705