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 sector_t ext2_bmap(struct address_space *mapping, sector_t block) 912 { 913 return generic_block_bmap(mapping,block,ext2_get_block); 914 } 915 916 static ssize_t 917 ext2_direct_IO(struct kiocb *iocb, struct iov_iter *iter) 918 { 919 struct file *file = iocb->ki_filp; 920 struct address_space *mapping = file->f_mapping; 921 struct inode *inode = mapping->host; 922 size_t count = iov_iter_count(iter); 923 loff_t offset = iocb->ki_pos; 924 ssize_t ret; 925 926 ret = blockdev_direct_IO(iocb, inode, iter, ext2_get_block); 927 if (ret < 0 && iov_iter_rw(iter) == WRITE) 928 ext2_write_failed(mapping, offset + count); 929 return ret; 930 } 931 932 static int 933 ext2_writepages(struct address_space *mapping, struct writeback_control *wbc) 934 { 935 return mpage_writepages(mapping, wbc, ext2_get_block); 936 } 937 938 static int 939 ext2_dax_writepages(struct address_space *mapping, struct writeback_control *wbc) 940 { 941 struct ext2_sb_info *sbi = EXT2_SB(mapping->host->i_sb); 942 943 return dax_writeback_mapping_range(mapping, sbi->s_daxdev, wbc); 944 } 945 946 const struct address_space_operations ext2_aops = { 947 .dirty_folio = block_dirty_folio, 948 .invalidate_folio = block_invalidate_folio, 949 .read_folio = ext2_read_folio, 950 .readahead = ext2_readahead, 951 .writepage = ext2_writepage, 952 .write_begin = ext2_write_begin, 953 .write_end = ext2_write_end, 954 .bmap = ext2_bmap, 955 .direct_IO = ext2_direct_IO, 956 .writepages = ext2_writepages, 957 .migrate_folio = buffer_migrate_folio, 958 .is_partially_uptodate = block_is_partially_uptodate, 959 .error_remove_page = generic_error_remove_page, 960 }; 961 962 static const struct address_space_operations ext2_dax_aops = { 963 .writepages = ext2_dax_writepages, 964 .direct_IO = noop_direct_IO, 965 .dirty_folio = noop_dirty_folio, 966 }; 967 968 /* 969 * Probably it should be a library function... search for first non-zero word 970 * or memcmp with zero_page, whatever is better for particular architecture. 971 * Linus? 972 */ 973 static inline int all_zeroes(__le32 *p, __le32 *q) 974 { 975 while (p < q) 976 if (*p++) 977 return 0; 978 return 1; 979 } 980 981 /** 982 * ext2_find_shared - find the indirect blocks for partial truncation. 983 * @inode: inode in question 984 * @depth: depth of the affected branch 985 * @offsets: offsets of pointers in that branch (see ext2_block_to_path) 986 * @chain: place to store the pointers to partial indirect blocks 987 * @top: place to the (detached) top of branch 988 * 989 * This is a helper function used by ext2_truncate(). 990 * 991 * When we do truncate() we may have to clean the ends of several indirect 992 * blocks but leave the blocks themselves alive. Block is partially 993 * truncated if some data below the new i_size is referred from it (and 994 * it is on the path to the first completely truncated data block, indeed). 995 * We have to free the top of that path along with everything to the right 996 * of the path. Since no allocation past the truncation point is possible 997 * until ext2_truncate() finishes, we may safely do the latter, but top 998 * of branch may require special attention - pageout below the truncation 999 * point might try to populate it. 1000 * 1001 * We atomically detach the top of branch from the tree, store the block 1002 * number of its root in *@top, pointers to buffer_heads of partially 1003 * truncated blocks - in @chain[].bh and pointers to their last elements 1004 * that should not be removed - in @chain[].p. Return value is the pointer 1005 * to last filled element of @chain. 1006 * 1007 * The work left to caller to do the actual freeing of subtrees: 1008 * a) free the subtree starting from *@top 1009 * b) free the subtrees whose roots are stored in 1010 * (@chain[i].p+1 .. end of @chain[i].bh->b_data) 1011 * c) free the subtrees growing from the inode past the @chain[0].p 1012 * (no partially truncated stuff there). 1013 */ 1014 1015 static Indirect *ext2_find_shared(struct inode *inode, 1016 int depth, 1017 int offsets[4], 1018 Indirect chain[4], 1019 __le32 *top) 1020 { 1021 Indirect *partial, *p; 1022 int k, err; 1023 1024 *top = 0; 1025 for (k = depth; k > 1 && !offsets[k-1]; k--) 1026 ; 1027 partial = ext2_get_branch(inode, k, offsets, chain, &err); 1028 if (!partial) 1029 partial = chain + k-1; 1030 /* 1031 * If the branch acquired continuation since we've looked at it - 1032 * fine, it should all survive and (new) top doesn't belong to us. 1033 */ 1034 write_lock(&EXT2_I(inode)->i_meta_lock); 1035 if (!partial->key && *partial->p) { 1036 write_unlock(&EXT2_I(inode)->i_meta_lock); 1037 goto no_top; 1038 } 1039 for (p=partial; p>chain && all_zeroes((__le32*)p->bh->b_data,p->p); p--) 1040 ; 1041 /* 1042 * OK, we've found the last block that must survive. The rest of our 1043 * branch should be detached before unlocking. However, if that rest 1044 * of branch is all ours and does not grow immediately from the inode 1045 * it's easier to cheat and just decrement partial->p. 1046 */ 1047 if (p == chain + k - 1 && p > chain) { 1048 p->p--; 1049 } else { 1050 *top = *p->p; 1051 *p->p = 0; 1052 } 1053 write_unlock(&EXT2_I(inode)->i_meta_lock); 1054 1055 while(partial > p) 1056 { 1057 brelse(partial->bh); 1058 partial--; 1059 } 1060 no_top: 1061 return partial; 1062 } 1063 1064 /** 1065 * ext2_free_data - free a list of data blocks 1066 * @inode: inode we are dealing with 1067 * @p: array of block numbers 1068 * @q: points immediately past the end of array 1069 * 1070 * We are freeing all blocks referred from that array (numbers are 1071 * stored as little-endian 32-bit) and updating @inode->i_blocks 1072 * appropriately. 1073 */ 1074 static inline void ext2_free_data(struct inode *inode, __le32 *p, __le32 *q) 1075 { 1076 unsigned long block_to_free = 0, count = 0; 1077 unsigned long nr; 1078 1079 for ( ; p < q ; p++) { 1080 nr = le32_to_cpu(*p); 1081 if (nr) { 1082 *p = 0; 1083 /* accumulate blocks to free if they're contiguous */ 1084 if (count == 0) 1085 goto free_this; 1086 else if (block_to_free == nr - count) 1087 count++; 1088 else { 1089 ext2_free_blocks (inode, block_to_free, count); 1090 mark_inode_dirty(inode); 1091 free_this: 1092 block_to_free = nr; 1093 count = 1; 1094 } 1095 } 1096 } 1097 if (count > 0) { 1098 ext2_free_blocks (inode, block_to_free, count); 1099 mark_inode_dirty(inode); 1100 } 1101 } 1102 1103 /** 1104 * ext2_free_branches - free an array of branches 1105 * @inode: inode we are dealing with 1106 * @p: array of block numbers 1107 * @q: pointer immediately past the end of array 1108 * @depth: depth of the branches to free 1109 * 1110 * We are freeing all blocks referred from these branches (numbers are 1111 * stored as little-endian 32-bit) and updating @inode->i_blocks 1112 * appropriately. 1113 */ 1114 static void ext2_free_branches(struct inode *inode, __le32 *p, __le32 *q, int depth) 1115 { 1116 struct buffer_head * bh; 1117 unsigned long nr; 1118 1119 if (depth--) { 1120 int addr_per_block = EXT2_ADDR_PER_BLOCK(inode->i_sb); 1121 for ( ; p < q ; p++) { 1122 nr = le32_to_cpu(*p); 1123 if (!nr) 1124 continue; 1125 *p = 0; 1126 bh = sb_bread(inode->i_sb, nr); 1127 /* 1128 * A read failure? Report error and clear slot 1129 * (should be rare). 1130 */ 1131 if (!bh) { 1132 ext2_error(inode->i_sb, "ext2_free_branches", 1133 "Read failure, inode=%ld, block=%ld", 1134 inode->i_ino, nr); 1135 continue; 1136 } 1137 ext2_free_branches(inode, 1138 (__le32*)bh->b_data, 1139 (__le32*)bh->b_data + addr_per_block, 1140 depth); 1141 bforget(bh); 1142 ext2_free_blocks(inode, nr, 1); 1143 mark_inode_dirty(inode); 1144 } 1145 } else 1146 ext2_free_data(inode, p, q); 1147 } 1148 1149 /* mapping->invalidate_lock must be held when calling this function */ 1150 static void __ext2_truncate_blocks(struct inode *inode, loff_t offset) 1151 { 1152 __le32 *i_data = EXT2_I(inode)->i_data; 1153 struct ext2_inode_info *ei = EXT2_I(inode); 1154 int addr_per_block = EXT2_ADDR_PER_BLOCK(inode->i_sb); 1155 int offsets[4]; 1156 Indirect chain[4]; 1157 Indirect *partial; 1158 __le32 nr = 0; 1159 int n; 1160 long iblock; 1161 unsigned blocksize; 1162 blocksize = inode->i_sb->s_blocksize; 1163 iblock = (offset + blocksize-1) >> EXT2_BLOCK_SIZE_BITS(inode->i_sb); 1164 1165 #ifdef CONFIG_FS_DAX 1166 WARN_ON(!rwsem_is_locked(&inode->i_mapping->invalidate_lock)); 1167 #endif 1168 1169 n = ext2_block_to_path(inode, iblock, offsets, NULL); 1170 if (n == 0) 1171 return; 1172 1173 /* 1174 * From here we block out all ext2_get_block() callers who want to 1175 * modify the block allocation tree. 1176 */ 1177 mutex_lock(&ei->truncate_mutex); 1178 1179 if (n == 1) { 1180 ext2_free_data(inode, i_data+offsets[0], 1181 i_data + EXT2_NDIR_BLOCKS); 1182 goto do_indirects; 1183 } 1184 1185 partial = ext2_find_shared(inode, n, offsets, chain, &nr); 1186 /* Kill the top of shared branch (already detached) */ 1187 if (nr) { 1188 if (partial == chain) 1189 mark_inode_dirty(inode); 1190 else 1191 mark_buffer_dirty_inode(partial->bh, inode); 1192 ext2_free_branches(inode, &nr, &nr+1, (chain+n-1) - partial); 1193 } 1194 /* Clear the ends of indirect blocks on the shared branch */ 1195 while (partial > chain) { 1196 ext2_free_branches(inode, 1197 partial->p + 1, 1198 (__le32*)partial->bh->b_data+addr_per_block, 1199 (chain+n-1) - partial); 1200 mark_buffer_dirty_inode(partial->bh, inode); 1201 brelse (partial->bh); 1202 partial--; 1203 } 1204 do_indirects: 1205 /* Kill the remaining (whole) subtrees */ 1206 switch (offsets[0]) { 1207 default: 1208 nr = i_data[EXT2_IND_BLOCK]; 1209 if (nr) { 1210 i_data[EXT2_IND_BLOCK] = 0; 1211 mark_inode_dirty(inode); 1212 ext2_free_branches(inode, &nr, &nr+1, 1); 1213 } 1214 fallthrough; 1215 case EXT2_IND_BLOCK: 1216 nr = i_data[EXT2_DIND_BLOCK]; 1217 if (nr) { 1218 i_data[EXT2_DIND_BLOCK] = 0; 1219 mark_inode_dirty(inode); 1220 ext2_free_branches(inode, &nr, &nr+1, 2); 1221 } 1222 fallthrough; 1223 case EXT2_DIND_BLOCK: 1224 nr = i_data[EXT2_TIND_BLOCK]; 1225 if (nr) { 1226 i_data[EXT2_TIND_BLOCK] = 0; 1227 mark_inode_dirty(inode); 1228 ext2_free_branches(inode, &nr, &nr+1, 3); 1229 } 1230 break; 1231 case EXT2_TIND_BLOCK: 1232 ; 1233 } 1234 1235 ext2_discard_reservation(inode); 1236 1237 mutex_unlock(&ei->truncate_mutex); 1238 } 1239 1240 static void ext2_truncate_blocks(struct inode *inode, loff_t offset) 1241 { 1242 if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || 1243 S_ISLNK(inode->i_mode))) 1244 return; 1245 if (ext2_inode_is_fast_symlink(inode)) 1246 return; 1247 1248 filemap_invalidate_lock(inode->i_mapping); 1249 __ext2_truncate_blocks(inode, offset); 1250 filemap_invalidate_unlock(inode->i_mapping); 1251 } 1252 1253 static int ext2_setsize(struct inode *inode, loff_t newsize) 1254 { 1255 int error; 1256 1257 if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || 1258 S_ISLNK(inode->i_mode))) 1259 return -EINVAL; 1260 if (ext2_inode_is_fast_symlink(inode)) 1261 return -EINVAL; 1262 if (IS_APPEND(inode) || IS_IMMUTABLE(inode)) 1263 return -EPERM; 1264 1265 inode_dio_wait(inode); 1266 1267 if (IS_DAX(inode)) 1268 error = dax_zero_range(inode, newsize, 1269 PAGE_ALIGN(newsize) - newsize, NULL, 1270 &ext2_iomap_ops); 1271 else 1272 error = block_truncate_page(inode->i_mapping, 1273 newsize, ext2_get_block); 1274 if (error) 1275 return error; 1276 1277 filemap_invalidate_lock(inode->i_mapping); 1278 truncate_setsize(inode, newsize); 1279 __ext2_truncate_blocks(inode, newsize); 1280 filemap_invalidate_unlock(inode->i_mapping); 1281 1282 inode->i_mtime = inode->i_ctime = current_time(inode); 1283 if (inode_needs_sync(inode)) { 1284 sync_mapping_buffers(inode->i_mapping); 1285 sync_inode_metadata(inode, 1); 1286 } else { 1287 mark_inode_dirty(inode); 1288 } 1289 1290 return 0; 1291 } 1292 1293 static struct ext2_inode *ext2_get_inode(struct super_block *sb, ino_t ino, 1294 struct buffer_head **p) 1295 { 1296 struct buffer_head * bh; 1297 unsigned long block_group; 1298 unsigned long block; 1299 unsigned long offset; 1300 struct ext2_group_desc * gdp; 1301 1302 *p = NULL; 1303 if ((ino != EXT2_ROOT_INO && ino < EXT2_FIRST_INO(sb)) || 1304 ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count)) 1305 goto Einval; 1306 1307 block_group = (ino - 1) / EXT2_INODES_PER_GROUP(sb); 1308 gdp = ext2_get_group_desc(sb, block_group, NULL); 1309 if (!gdp) 1310 goto Egdp; 1311 /* 1312 * Figure out the offset within the block group inode table 1313 */ 1314 offset = ((ino - 1) % EXT2_INODES_PER_GROUP(sb)) * EXT2_INODE_SIZE(sb); 1315 block = le32_to_cpu(gdp->bg_inode_table) + 1316 (offset >> EXT2_BLOCK_SIZE_BITS(sb)); 1317 if (!(bh = sb_bread(sb, block))) 1318 goto Eio; 1319 1320 *p = bh; 1321 offset &= (EXT2_BLOCK_SIZE(sb) - 1); 1322 return (struct ext2_inode *) (bh->b_data + offset); 1323 1324 Einval: 1325 ext2_error(sb, "ext2_get_inode", "bad inode number: %lu", 1326 (unsigned long) ino); 1327 return ERR_PTR(-EINVAL); 1328 Eio: 1329 ext2_error(sb, "ext2_get_inode", 1330 "unable to read inode block - inode=%lu, block=%lu", 1331 (unsigned long) ino, block); 1332 Egdp: 1333 return ERR_PTR(-EIO); 1334 } 1335 1336 void ext2_set_inode_flags(struct inode *inode) 1337 { 1338 unsigned int flags = EXT2_I(inode)->i_flags; 1339 1340 inode->i_flags &= ~(S_SYNC | S_APPEND | S_IMMUTABLE | S_NOATIME | 1341 S_DIRSYNC | S_DAX); 1342 if (flags & EXT2_SYNC_FL) 1343 inode->i_flags |= S_SYNC; 1344 if (flags & EXT2_APPEND_FL) 1345 inode->i_flags |= S_APPEND; 1346 if (flags & EXT2_IMMUTABLE_FL) 1347 inode->i_flags |= S_IMMUTABLE; 1348 if (flags & EXT2_NOATIME_FL) 1349 inode->i_flags |= S_NOATIME; 1350 if (flags & EXT2_DIRSYNC_FL) 1351 inode->i_flags |= S_DIRSYNC; 1352 if (test_opt(inode->i_sb, DAX) && S_ISREG(inode->i_mode)) 1353 inode->i_flags |= S_DAX; 1354 } 1355 1356 void ext2_set_file_ops(struct inode *inode) 1357 { 1358 inode->i_op = &ext2_file_inode_operations; 1359 inode->i_fop = &ext2_file_operations; 1360 if (IS_DAX(inode)) 1361 inode->i_mapping->a_ops = &ext2_dax_aops; 1362 else 1363 inode->i_mapping->a_ops = &ext2_aops; 1364 } 1365 1366 struct inode *ext2_iget (struct super_block *sb, unsigned long ino) 1367 { 1368 struct ext2_inode_info *ei; 1369 struct buffer_head * bh = NULL; 1370 struct ext2_inode *raw_inode; 1371 struct inode *inode; 1372 long ret = -EIO; 1373 int n; 1374 uid_t i_uid; 1375 gid_t i_gid; 1376 1377 inode = iget_locked(sb, ino); 1378 if (!inode) 1379 return ERR_PTR(-ENOMEM); 1380 if (!(inode->i_state & I_NEW)) 1381 return inode; 1382 1383 ei = EXT2_I(inode); 1384 ei->i_block_alloc_info = NULL; 1385 1386 raw_inode = ext2_get_inode(inode->i_sb, ino, &bh); 1387 if (IS_ERR(raw_inode)) { 1388 ret = PTR_ERR(raw_inode); 1389 goto bad_inode; 1390 } 1391 1392 inode->i_mode = le16_to_cpu(raw_inode->i_mode); 1393 i_uid = (uid_t)le16_to_cpu(raw_inode->i_uid_low); 1394 i_gid = (gid_t)le16_to_cpu(raw_inode->i_gid_low); 1395 if (!(test_opt (inode->i_sb, NO_UID32))) { 1396 i_uid |= le16_to_cpu(raw_inode->i_uid_high) << 16; 1397 i_gid |= le16_to_cpu(raw_inode->i_gid_high) << 16; 1398 } 1399 i_uid_write(inode, i_uid); 1400 i_gid_write(inode, i_gid); 1401 set_nlink(inode, le16_to_cpu(raw_inode->i_links_count)); 1402 inode->i_size = le32_to_cpu(raw_inode->i_size); 1403 inode->i_atime.tv_sec = (signed)le32_to_cpu(raw_inode->i_atime); 1404 inode->i_ctime.tv_sec = (signed)le32_to_cpu(raw_inode->i_ctime); 1405 inode->i_mtime.tv_sec = (signed)le32_to_cpu(raw_inode->i_mtime); 1406 inode->i_atime.tv_nsec = inode->i_mtime.tv_nsec = inode->i_ctime.tv_nsec = 0; 1407 ei->i_dtime = le32_to_cpu(raw_inode->i_dtime); 1408 /* We now have enough fields to check if the inode was active or not. 1409 * This is needed because nfsd might try to access dead inodes 1410 * the test is that same one that e2fsck uses 1411 * NeilBrown 1999oct15 1412 */ 1413 if (inode->i_nlink == 0 && (inode->i_mode == 0 || ei->i_dtime)) { 1414 /* this inode is deleted */ 1415 ret = -ESTALE; 1416 goto bad_inode; 1417 } 1418 inode->i_blocks = le32_to_cpu(raw_inode->i_blocks); 1419 ei->i_flags = le32_to_cpu(raw_inode->i_flags); 1420 ext2_set_inode_flags(inode); 1421 ei->i_faddr = le32_to_cpu(raw_inode->i_faddr); 1422 ei->i_frag_no = raw_inode->i_frag; 1423 ei->i_frag_size = raw_inode->i_fsize; 1424 ei->i_file_acl = le32_to_cpu(raw_inode->i_file_acl); 1425 ei->i_dir_acl = 0; 1426 1427 if (ei->i_file_acl && 1428 !ext2_data_block_valid(EXT2_SB(sb), ei->i_file_acl, 1)) { 1429 ext2_error(sb, "ext2_iget", "bad extended attribute block %u", 1430 ei->i_file_acl); 1431 ret = -EFSCORRUPTED; 1432 goto bad_inode; 1433 } 1434 1435 if (S_ISREG(inode->i_mode)) 1436 inode->i_size |= ((__u64)le32_to_cpu(raw_inode->i_size_high)) << 32; 1437 else 1438 ei->i_dir_acl = le32_to_cpu(raw_inode->i_dir_acl); 1439 if (i_size_read(inode) < 0) { 1440 ret = -EFSCORRUPTED; 1441 goto bad_inode; 1442 } 1443 ei->i_dtime = 0; 1444 inode->i_generation = le32_to_cpu(raw_inode->i_generation); 1445 ei->i_state = 0; 1446 ei->i_block_group = (ino - 1) / EXT2_INODES_PER_GROUP(inode->i_sb); 1447 ei->i_dir_start_lookup = 0; 1448 1449 /* 1450 * NOTE! The in-memory inode i_data array is in little-endian order 1451 * even on big-endian machines: we do NOT byteswap the block numbers! 1452 */ 1453 for (n = 0; n < EXT2_N_BLOCKS; n++) 1454 ei->i_data[n] = raw_inode->i_block[n]; 1455 1456 if (S_ISREG(inode->i_mode)) { 1457 ext2_set_file_ops(inode); 1458 } else if (S_ISDIR(inode->i_mode)) { 1459 inode->i_op = &ext2_dir_inode_operations; 1460 inode->i_fop = &ext2_dir_operations; 1461 inode->i_mapping->a_ops = &ext2_aops; 1462 } else if (S_ISLNK(inode->i_mode)) { 1463 if (ext2_inode_is_fast_symlink(inode)) { 1464 inode->i_link = (char *)ei->i_data; 1465 inode->i_op = &ext2_fast_symlink_inode_operations; 1466 nd_terminate_link(ei->i_data, inode->i_size, 1467 sizeof(ei->i_data) - 1); 1468 } else { 1469 inode->i_op = &ext2_symlink_inode_operations; 1470 inode_nohighmem(inode); 1471 inode->i_mapping->a_ops = &ext2_aops; 1472 } 1473 } else { 1474 inode->i_op = &ext2_special_inode_operations; 1475 if (raw_inode->i_block[0]) 1476 init_special_inode(inode, inode->i_mode, 1477 old_decode_dev(le32_to_cpu(raw_inode->i_block[0]))); 1478 else 1479 init_special_inode(inode, inode->i_mode, 1480 new_decode_dev(le32_to_cpu(raw_inode->i_block[1]))); 1481 } 1482 brelse (bh); 1483 unlock_new_inode(inode); 1484 return inode; 1485 1486 bad_inode: 1487 brelse(bh); 1488 iget_failed(inode); 1489 return ERR_PTR(ret); 1490 } 1491 1492 static int __ext2_write_inode(struct inode *inode, int do_sync) 1493 { 1494 struct ext2_inode_info *ei = EXT2_I(inode); 1495 struct super_block *sb = inode->i_sb; 1496 ino_t ino = inode->i_ino; 1497 uid_t uid = i_uid_read(inode); 1498 gid_t gid = i_gid_read(inode); 1499 struct buffer_head * bh; 1500 struct ext2_inode * raw_inode = ext2_get_inode(sb, ino, &bh); 1501 int n; 1502 int err = 0; 1503 1504 if (IS_ERR(raw_inode)) 1505 return -EIO; 1506 1507 /* For fields not tracking in the in-memory inode, 1508 * initialise them to zero for new inodes. */ 1509 if (ei->i_state & EXT2_STATE_NEW) 1510 memset(raw_inode, 0, EXT2_SB(sb)->s_inode_size); 1511 1512 raw_inode->i_mode = cpu_to_le16(inode->i_mode); 1513 if (!(test_opt(sb, NO_UID32))) { 1514 raw_inode->i_uid_low = cpu_to_le16(low_16_bits(uid)); 1515 raw_inode->i_gid_low = cpu_to_le16(low_16_bits(gid)); 1516 /* 1517 * Fix up interoperability with old kernels. Otherwise, old inodes get 1518 * re-used with the upper 16 bits of the uid/gid intact 1519 */ 1520 if (!ei->i_dtime) { 1521 raw_inode->i_uid_high = cpu_to_le16(high_16_bits(uid)); 1522 raw_inode->i_gid_high = cpu_to_le16(high_16_bits(gid)); 1523 } else { 1524 raw_inode->i_uid_high = 0; 1525 raw_inode->i_gid_high = 0; 1526 } 1527 } else { 1528 raw_inode->i_uid_low = cpu_to_le16(fs_high2lowuid(uid)); 1529 raw_inode->i_gid_low = cpu_to_le16(fs_high2lowgid(gid)); 1530 raw_inode->i_uid_high = 0; 1531 raw_inode->i_gid_high = 0; 1532 } 1533 raw_inode->i_links_count = cpu_to_le16(inode->i_nlink); 1534 raw_inode->i_size = cpu_to_le32(inode->i_size); 1535 raw_inode->i_atime = cpu_to_le32(inode->i_atime.tv_sec); 1536 raw_inode->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec); 1537 raw_inode->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec); 1538 1539 raw_inode->i_blocks = cpu_to_le32(inode->i_blocks); 1540 raw_inode->i_dtime = cpu_to_le32(ei->i_dtime); 1541 raw_inode->i_flags = cpu_to_le32(ei->i_flags); 1542 raw_inode->i_faddr = cpu_to_le32(ei->i_faddr); 1543 raw_inode->i_frag = ei->i_frag_no; 1544 raw_inode->i_fsize = ei->i_frag_size; 1545 raw_inode->i_file_acl = cpu_to_le32(ei->i_file_acl); 1546 if (!S_ISREG(inode->i_mode)) 1547 raw_inode->i_dir_acl = cpu_to_le32(ei->i_dir_acl); 1548 else { 1549 raw_inode->i_size_high = cpu_to_le32(inode->i_size >> 32); 1550 if (inode->i_size > 0x7fffffffULL) { 1551 if (!EXT2_HAS_RO_COMPAT_FEATURE(sb, 1552 EXT2_FEATURE_RO_COMPAT_LARGE_FILE) || 1553 EXT2_SB(sb)->s_es->s_rev_level == 1554 cpu_to_le32(EXT2_GOOD_OLD_REV)) { 1555 /* If this is the first large file 1556 * created, add a flag to the superblock. 1557 */ 1558 spin_lock(&EXT2_SB(sb)->s_lock); 1559 ext2_update_dynamic_rev(sb); 1560 EXT2_SET_RO_COMPAT_FEATURE(sb, 1561 EXT2_FEATURE_RO_COMPAT_LARGE_FILE); 1562 spin_unlock(&EXT2_SB(sb)->s_lock); 1563 ext2_sync_super(sb, EXT2_SB(sb)->s_es, 1); 1564 } 1565 } 1566 } 1567 1568 raw_inode->i_generation = cpu_to_le32(inode->i_generation); 1569 if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) { 1570 if (old_valid_dev(inode->i_rdev)) { 1571 raw_inode->i_block[0] = 1572 cpu_to_le32(old_encode_dev(inode->i_rdev)); 1573 raw_inode->i_block[1] = 0; 1574 } else { 1575 raw_inode->i_block[0] = 0; 1576 raw_inode->i_block[1] = 1577 cpu_to_le32(new_encode_dev(inode->i_rdev)); 1578 raw_inode->i_block[2] = 0; 1579 } 1580 } else for (n = 0; n < EXT2_N_BLOCKS; n++) 1581 raw_inode->i_block[n] = ei->i_data[n]; 1582 mark_buffer_dirty(bh); 1583 if (do_sync) { 1584 sync_dirty_buffer(bh); 1585 if (buffer_req(bh) && !buffer_uptodate(bh)) { 1586 printk ("IO error syncing ext2 inode [%s:%08lx]\n", 1587 sb->s_id, (unsigned long) ino); 1588 err = -EIO; 1589 } 1590 } 1591 ei->i_state &= ~EXT2_STATE_NEW; 1592 brelse (bh); 1593 return err; 1594 } 1595 1596 int ext2_write_inode(struct inode *inode, struct writeback_control *wbc) 1597 { 1598 return __ext2_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL); 1599 } 1600 1601 int ext2_getattr(struct user_namespace *mnt_userns, const struct path *path, 1602 struct kstat *stat, u32 request_mask, unsigned int query_flags) 1603 { 1604 struct inode *inode = d_inode(path->dentry); 1605 struct ext2_inode_info *ei = EXT2_I(inode); 1606 unsigned int flags; 1607 1608 flags = ei->i_flags & EXT2_FL_USER_VISIBLE; 1609 if (flags & EXT2_APPEND_FL) 1610 stat->attributes |= STATX_ATTR_APPEND; 1611 if (flags & EXT2_COMPR_FL) 1612 stat->attributes |= STATX_ATTR_COMPRESSED; 1613 if (flags & EXT2_IMMUTABLE_FL) 1614 stat->attributes |= STATX_ATTR_IMMUTABLE; 1615 if (flags & EXT2_NODUMP_FL) 1616 stat->attributes |= STATX_ATTR_NODUMP; 1617 stat->attributes_mask |= (STATX_ATTR_APPEND | 1618 STATX_ATTR_COMPRESSED | 1619 STATX_ATTR_ENCRYPTED | 1620 STATX_ATTR_IMMUTABLE | 1621 STATX_ATTR_NODUMP); 1622 1623 generic_fillattr(&init_user_ns, inode, stat); 1624 return 0; 1625 } 1626 1627 int ext2_setattr(struct user_namespace *mnt_userns, struct dentry *dentry, 1628 struct iattr *iattr) 1629 { 1630 struct inode *inode = d_inode(dentry); 1631 int error; 1632 1633 error = setattr_prepare(&init_user_ns, dentry, iattr); 1634 if (error) 1635 return error; 1636 1637 if (is_quota_modification(mnt_userns, inode, iattr)) { 1638 error = dquot_initialize(inode); 1639 if (error) 1640 return error; 1641 } 1642 if (i_uid_needs_update(mnt_userns, iattr, inode) || 1643 i_gid_needs_update(mnt_userns, iattr, inode)) { 1644 error = dquot_transfer(mnt_userns, inode, iattr); 1645 if (error) 1646 return error; 1647 } 1648 if (iattr->ia_valid & ATTR_SIZE && iattr->ia_size != inode->i_size) { 1649 error = ext2_setsize(inode, iattr->ia_size); 1650 if (error) 1651 return error; 1652 } 1653 setattr_copy(&init_user_ns, inode, iattr); 1654 if (iattr->ia_valid & ATTR_MODE) 1655 error = posix_acl_chmod(&init_user_ns, inode, inode->i_mode); 1656 mark_inode_dirty(inode); 1657 1658 return error; 1659 } 1660