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 total number of blocks to be allocate, including the 359 * direct and indirect blocks. 360 */ 361 static int 362 ext2_blks_to_allocate(Indirect * branch, int k, unsigned long blks, 363 int blocks_to_boundary) 364 { 365 unsigned long count = 0; 366 367 /* 368 * Simple case, [t,d]Indirect block(s) has not allocated yet 369 * then it's clear blocks on that path have not allocated 370 */ 371 if (k > 0) { 372 /* right now don't hanel cross boundary allocation */ 373 if (blks < blocks_to_boundary + 1) 374 count += blks; 375 else 376 count += blocks_to_boundary + 1; 377 return count; 378 } 379 380 count++; 381 while (count < blks && count <= blocks_to_boundary 382 && le32_to_cpu(*(branch[0].p + count)) == 0) { 383 count++; 384 } 385 return count; 386 } 387 388 /** 389 * ext2_alloc_blocks: multiple allocate blocks needed for a branch 390 * @indirect_blks: the number of blocks need to allocate for indirect 391 * blocks 392 * 393 * @new_blocks: on return it will store the new block numbers for 394 * the indirect blocks(if needed) and the first direct block, 395 * @blks: on return it will store the total number of allocated 396 * direct blocks 397 */ 398 static int ext2_alloc_blocks(struct inode *inode, 399 ext2_fsblk_t goal, int indirect_blks, int blks, 400 ext2_fsblk_t new_blocks[4], int *err) 401 { 402 int target, i; 403 unsigned long count = 0; 404 int index = 0; 405 ext2_fsblk_t current_block = 0; 406 int ret = 0; 407 408 /* 409 * Here we try to allocate the requested multiple blocks at once, 410 * on a best-effort basis. 411 * To build a branch, we should allocate blocks for 412 * the indirect blocks(if not allocated yet), and at least 413 * the first direct block of this branch. That's the 414 * minimum number of blocks need to allocate(required) 415 */ 416 target = blks + indirect_blks; 417 418 while (1) { 419 count = target; 420 /* allocating blocks for indirect blocks and direct blocks */ 421 current_block = ext2_new_blocks(inode,goal,&count,err); 422 if (*err) 423 goto failed_out; 424 425 target -= count; 426 /* allocate blocks for indirect blocks */ 427 while (index < indirect_blks && count) { 428 new_blocks[index++] = current_block++; 429 count--; 430 } 431 432 if (count > 0) 433 break; 434 } 435 436 /* save the new block number for the first direct block */ 437 new_blocks[index] = current_block; 438 439 /* total number of blocks allocated for direct blocks */ 440 ret = count; 441 *err = 0; 442 return ret; 443 failed_out: 444 for (i = 0; i <index; i++) 445 ext2_free_blocks(inode, new_blocks[i], 1); 446 if (index) 447 mark_inode_dirty(inode); 448 return ret; 449 } 450 451 /** 452 * ext2_alloc_branch - allocate and set up a chain of blocks. 453 * @inode: owner 454 * @indirect_blks: depth of the chain (number of blocks to allocate) 455 * @blks: number of allocated direct blocks 456 * @goal: preferred place for allocation 457 * @offsets: offsets (in the blocks) to store the pointers to next. 458 * @branch: place to store the chain in. 459 * 460 * This function allocates @num blocks, zeroes out all but the last one, 461 * links them into chain and (if we are synchronous) writes them to disk. 462 * In other words, it prepares a branch that can be spliced onto the 463 * inode. It stores the information about that chain in the branch[], in 464 * the same format as ext2_get_branch() would do. We are calling it after 465 * we had read the existing part of chain and partial points to the last 466 * triple of that (one with zero ->key). Upon the exit we have the same 467 * picture as after the successful ext2_get_block(), except that in one 468 * place chain is disconnected - *branch->p is still zero (we did not 469 * set the last link), but branch->key contains the number that should 470 * be placed into *branch->p to fill that gap. 471 * 472 * If allocation fails we free all blocks we've allocated (and forget 473 * their buffer_heads) and return the error value the from failed 474 * ext2_alloc_block() (normally -ENOSPC). Otherwise we set the chain 475 * as described above and return 0. 476 */ 477 478 static int ext2_alloc_branch(struct inode *inode, 479 int indirect_blks, int *blks, ext2_fsblk_t goal, 480 int *offsets, Indirect *branch) 481 { 482 int blocksize = inode->i_sb->s_blocksize; 483 int i, n = 0; 484 int err = 0; 485 struct buffer_head *bh; 486 int num; 487 ext2_fsblk_t new_blocks[4]; 488 ext2_fsblk_t current_block; 489 490 num = ext2_alloc_blocks(inode, goal, indirect_blks, 491 *blks, new_blocks, &err); 492 if (err) 493 return err; 494 495 branch[0].key = cpu_to_le32(new_blocks[0]); 496 /* 497 * metadata blocks and data blocks are allocated. 498 */ 499 for (n = 1; n <= indirect_blks; n++) { 500 /* 501 * Get buffer_head for parent block, zero it out 502 * and set the pointer to new one, then send 503 * parent to disk. 504 */ 505 bh = sb_getblk(inode->i_sb, new_blocks[n-1]); 506 if (unlikely(!bh)) { 507 err = -ENOMEM; 508 goto failed; 509 } 510 branch[n].bh = bh; 511 lock_buffer(bh); 512 memset(bh->b_data, 0, blocksize); 513 branch[n].p = (__le32 *) bh->b_data + offsets[n]; 514 branch[n].key = cpu_to_le32(new_blocks[n]); 515 *branch[n].p = branch[n].key; 516 if ( n == indirect_blks) { 517 current_block = new_blocks[n]; 518 /* 519 * End of chain, update the last new metablock of 520 * the chain to point to the new allocated 521 * data blocks numbers 522 */ 523 for (i=1; i < num; i++) 524 *(branch[n].p + i) = cpu_to_le32(++current_block); 525 } 526 set_buffer_uptodate(bh); 527 unlock_buffer(bh); 528 mark_buffer_dirty_inode(bh, inode); 529 /* We used to sync bh here if IS_SYNC(inode). 530 * But we now rely upon generic_write_sync() 531 * and b_inode_buffers. But not for directories. 532 */ 533 if (S_ISDIR(inode->i_mode) && IS_DIRSYNC(inode)) 534 sync_dirty_buffer(bh); 535 } 536 *blks = num; 537 return err; 538 539 failed: 540 for (i = 1; i < n; i++) 541 bforget(branch[i].bh); 542 for (i = 0; i < indirect_blks; i++) 543 ext2_free_blocks(inode, new_blocks[i], 1); 544 ext2_free_blocks(inode, new_blocks[i], num); 545 return err; 546 } 547 548 /** 549 * ext2_splice_branch - splice the allocated branch onto inode. 550 * @inode: owner 551 * @block: (logical) number of block we are adding 552 * @where: location of missing link 553 * @num: number of indirect blocks we are adding 554 * @blks: number of direct blocks we are adding 555 * 556 * This function fills the missing link and does all housekeeping needed in 557 * inode (->i_blocks, etc.). In case of success we end up with the full 558 * chain to new block and return 0. 559 */ 560 static void ext2_splice_branch(struct inode *inode, 561 long block, Indirect *where, int num, int blks) 562 { 563 int i; 564 struct ext2_block_alloc_info *block_i; 565 ext2_fsblk_t current_block; 566 567 block_i = EXT2_I(inode)->i_block_alloc_info; 568 569 /* XXX LOCKING probably should have i_meta_lock ?*/ 570 /* That's it */ 571 572 *where->p = where->key; 573 574 /* 575 * Update the host buffer_head or inode to point to more just allocated 576 * direct blocks blocks 577 */ 578 if (num == 0 && blks > 1) { 579 current_block = le32_to_cpu(where->key) + 1; 580 for (i = 1; i < blks; i++) 581 *(where->p + i ) = cpu_to_le32(current_block++); 582 } 583 584 /* 585 * update the most recently allocated logical & physical block 586 * in i_block_alloc_info, to assist find the proper goal block for next 587 * allocation 588 */ 589 if (block_i) { 590 block_i->last_alloc_logical_block = block + blks - 1; 591 block_i->last_alloc_physical_block = 592 le32_to_cpu(where[num].key) + blks - 1; 593 } 594 595 /* We are done with atomic stuff, now do the rest of housekeeping */ 596 597 /* had we spliced it onto indirect block? */ 598 if (where->bh) 599 mark_buffer_dirty_inode(where->bh, inode); 600 601 inode->i_ctime = current_time(inode); 602 mark_inode_dirty(inode); 603 } 604 605 /* 606 * Allocation strategy is simple: if we have to allocate something, we will 607 * have to go the whole way to leaf. So let's do it before attaching anything 608 * to tree, set linkage between the newborn blocks, write them if sync is 609 * required, recheck the path, free and repeat if check fails, otherwise 610 * set the last missing link (that will protect us from any truncate-generated 611 * removals - all blocks on the path are immune now) and possibly force the 612 * write on the parent block. 613 * That has a nice additional property: no special recovery from the failed 614 * allocations is needed - we simply release blocks and do not touch anything 615 * reachable from inode. 616 * 617 * `handle' can be NULL if create == 0. 618 * 619 * return > 0, # of blocks mapped or allocated. 620 * return = 0, if plain lookup failed. 621 * return < 0, error case. 622 */ 623 static int ext2_get_blocks(struct inode *inode, 624 sector_t iblock, unsigned long maxblocks, 625 u32 *bno, bool *new, bool *boundary, 626 int create) 627 { 628 int err; 629 int offsets[4]; 630 Indirect chain[4]; 631 Indirect *partial; 632 ext2_fsblk_t goal; 633 int indirect_blks; 634 int blocks_to_boundary = 0; 635 int depth; 636 struct ext2_inode_info *ei = EXT2_I(inode); 637 int count = 0; 638 ext2_fsblk_t first_block = 0; 639 640 BUG_ON(maxblocks == 0); 641 642 depth = ext2_block_to_path(inode,iblock,offsets,&blocks_to_boundary); 643 644 if (depth == 0) 645 return -EIO; 646 647 partial = ext2_get_branch(inode, depth, offsets, chain, &err); 648 /* Simplest case - block found, no allocation needed */ 649 if (!partial) { 650 first_block = le32_to_cpu(chain[depth - 1].key); 651 count++; 652 /*map more blocks*/ 653 while (count < maxblocks && count <= blocks_to_boundary) { 654 ext2_fsblk_t blk; 655 656 if (!verify_chain(chain, chain + depth - 1)) { 657 /* 658 * Indirect block might be removed by 659 * truncate while we were reading it. 660 * Handling of that case: forget what we've 661 * got now, go to reread. 662 */ 663 err = -EAGAIN; 664 count = 0; 665 partial = chain + depth - 1; 666 break; 667 } 668 blk = le32_to_cpu(*(chain[depth-1].p + count)); 669 if (blk == first_block + count) 670 count++; 671 else 672 break; 673 } 674 if (err != -EAGAIN) 675 goto got_it; 676 } 677 678 /* Next simple case - plain lookup or failed read of indirect block */ 679 if (!create || err == -EIO) 680 goto cleanup; 681 682 mutex_lock(&ei->truncate_mutex); 683 /* 684 * If the indirect block is missing while we are reading 685 * the chain(ext2_get_branch() returns -EAGAIN err), or 686 * if the chain has been changed after we grab the semaphore, 687 * (either because another process truncated this branch, or 688 * another get_block allocated this branch) re-grab the chain to see if 689 * the request block has been allocated or not. 690 * 691 * Since we already block the truncate/other get_block 692 * at this point, we will have the current copy of the chain when we 693 * splice the branch into the tree. 694 */ 695 if (err == -EAGAIN || !verify_chain(chain, partial)) { 696 while (partial > chain) { 697 brelse(partial->bh); 698 partial--; 699 } 700 partial = ext2_get_branch(inode, depth, offsets, chain, &err); 701 if (!partial) { 702 count++; 703 mutex_unlock(&ei->truncate_mutex); 704 goto got_it; 705 } 706 707 if (err) { 708 mutex_unlock(&ei->truncate_mutex); 709 goto cleanup; 710 } 711 } 712 713 /* 714 * Okay, we need to do block allocation. Lazily initialize the block 715 * allocation info here if necessary 716 */ 717 if (S_ISREG(inode->i_mode) && (!ei->i_block_alloc_info)) 718 ext2_init_block_alloc_info(inode); 719 720 goal = ext2_find_goal(inode, iblock, partial); 721 722 /* the number of blocks need to allocate for [d,t]indirect blocks */ 723 indirect_blks = (chain + depth) - partial - 1; 724 /* 725 * Next look up the indirect map to count the total number of 726 * direct blocks to allocate for this branch. 727 */ 728 count = ext2_blks_to_allocate(partial, indirect_blks, 729 maxblocks, blocks_to_boundary); 730 /* 731 * XXX ???? Block out ext2_truncate while we alter the tree 732 */ 733 err = ext2_alloc_branch(inode, indirect_blks, &count, goal, 734 offsets + (partial - chain), partial); 735 736 if (err) { 737 mutex_unlock(&ei->truncate_mutex); 738 goto cleanup; 739 } 740 741 if (IS_DAX(inode)) { 742 /* 743 * We must unmap blocks before zeroing so that writeback cannot 744 * overwrite zeros with stale data from block device page cache. 745 */ 746 clean_bdev_aliases(inode->i_sb->s_bdev, 747 le32_to_cpu(chain[depth-1].key), 748 count); 749 /* 750 * block must be initialised before we put it in the tree 751 * so that it's not found by another thread before it's 752 * initialised 753 */ 754 err = sb_issue_zeroout(inode->i_sb, 755 le32_to_cpu(chain[depth-1].key), count, 756 GFP_NOFS); 757 if (err) { 758 mutex_unlock(&ei->truncate_mutex); 759 goto cleanup; 760 } 761 } 762 *new = true; 763 764 ext2_splice_branch(inode, iblock, partial, indirect_blks, count); 765 mutex_unlock(&ei->truncate_mutex); 766 got_it: 767 if (count > blocks_to_boundary) 768 *boundary = true; 769 err = count; 770 /* Clean up and exit */ 771 partial = chain + depth - 1; /* the whole chain */ 772 cleanup: 773 while (partial > chain) { 774 brelse(partial->bh); 775 partial--; 776 } 777 if (err > 0) 778 *bno = le32_to_cpu(chain[depth-1].key); 779 return err; 780 } 781 782 int ext2_get_block(struct inode *inode, sector_t iblock, 783 struct buffer_head *bh_result, int create) 784 { 785 unsigned max_blocks = bh_result->b_size >> inode->i_blkbits; 786 bool new = false, boundary = false; 787 u32 bno; 788 int ret; 789 790 ret = ext2_get_blocks(inode, iblock, max_blocks, &bno, &new, &boundary, 791 create); 792 if (ret <= 0) 793 return ret; 794 795 map_bh(bh_result, inode->i_sb, bno); 796 bh_result->b_size = (ret << inode->i_blkbits); 797 if (new) 798 set_buffer_new(bh_result); 799 if (boundary) 800 set_buffer_boundary(bh_result); 801 return 0; 802 803 } 804 805 #ifdef CONFIG_FS_DAX 806 static int ext2_iomap_begin(struct inode *inode, loff_t offset, loff_t length, 807 unsigned flags, struct iomap *iomap, struct iomap *srcmap) 808 { 809 unsigned int blkbits = inode->i_blkbits; 810 unsigned long first_block = offset >> blkbits; 811 unsigned long max_blocks = (length + (1 << blkbits) - 1) >> blkbits; 812 struct ext2_sb_info *sbi = EXT2_SB(inode->i_sb); 813 bool new = false, boundary = false; 814 u32 bno; 815 int ret; 816 817 ret = ext2_get_blocks(inode, first_block, max_blocks, 818 &bno, &new, &boundary, flags & IOMAP_WRITE); 819 if (ret < 0) 820 return ret; 821 822 iomap->flags = 0; 823 iomap->bdev = inode->i_sb->s_bdev; 824 iomap->offset = (u64)first_block << blkbits; 825 iomap->dax_dev = sbi->s_daxdev; 826 827 if (ret == 0) { 828 iomap->type = IOMAP_HOLE; 829 iomap->addr = IOMAP_NULL_ADDR; 830 iomap->length = 1 << blkbits; 831 } else { 832 iomap->type = IOMAP_MAPPED; 833 iomap->addr = (u64)bno << blkbits; 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 #else 859 /* Define empty ops for !CONFIG_FS_DAX case to avoid ugly ifdefs */ 860 const struct iomap_ops ext2_iomap_ops; 861 #endif /* CONFIG_FS_DAX */ 862 863 int ext2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, 864 u64 start, u64 len) 865 { 866 return generic_block_fiemap(inode, fieinfo, start, len, 867 ext2_get_block); 868 } 869 870 static int ext2_writepage(struct page *page, struct writeback_control *wbc) 871 { 872 return block_write_full_page(page, ext2_get_block, wbc); 873 } 874 875 static int ext2_readpage(struct file *file, struct page *page) 876 { 877 return mpage_readpage(page, ext2_get_block); 878 } 879 880 static int 881 ext2_readpages(struct file *file, struct address_space *mapping, 882 struct list_head *pages, unsigned nr_pages) 883 { 884 return mpage_readpages(mapping, pages, nr_pages, 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, unsigned flags, 890 struct page **pagep, void **fsdata) 891 { 892 int ret; 893 894 ret = block_write_begin(mapping, pos, len, flags, pagep, 895 ext2_get_block); 896 if (ret < 0) 897 ext2_write_failed(mapping, pos + len); 898 return ret; 899 } 900 901 static int ext2_write_end(struct file *file, struct address_space *mapping, 902 loff_t pos, unsigned len, unsigned copied, 903 struct page *page, void *fsdata) 904 { 905 int ret; 906 907 ret = generic_write_end(file, mapping, pos, len, copied, page, fsdata); 908 if (ret < len) 909 ext2_write_failed(mapping, pos + len); 910 return ret; 911 } 912 913 static int 914 ext2_nobh_write_begin(struct file *file, struct address_space *mapping, 915 loff_t pos, unsigned len, unsigned flags, 916 struct page **pagep, void **fsdata) 917 { 918 int ret; 919 920 ret = nobh_write_begin(mapping, pos, len, flags, pagep, fsdata, 921 ext2_get_block); 922 if (ret < 0) 923 ext2_write_failed(mapping, pos + len); 924 return ret; 925 } 926 927 static int ext2_nobh_writepage(struct page *page, 928 struct writeback_control *wbc) 929 { 930 return nobh_writepage(page, ext2_get_block, wbc); 931 } 932 933 static sector_t ext2_bmap(struct address_space *mapping, sector_t block) 934 { 935 return generic_block_bmap(mapping,block,ext2_get_block); 936 } 937 938 static ssize_t 939 ext2_direct_IO(struct kiocb *iocb, struct iov_iter *iter) 940 { 941 struct file *file = iocb->ki_filp; 942 struct address_space *mapping = file->f_mapping; 943 struct inode *inode = mapping->host; 944 size_t count = iov_iter_count(iter); 945 loff_t offset = iocb->ki_pos; 946 ssize_t ret; 947 948 ret = blockdev_direct_IO(iocb, inode, iter, ext2_get_block); 949 if (ret < 0 && iov_iter_rw(iter) == WRITE) 950 ext2_write_failed(mapping, offset + count); 951 return ret; 952 } 953 954 static int 955 ext2_writepages(struct address_space *mapping, struct writeback_control *wbc) 956 { 957 return mpage_writepages(mapping, wbc, ext2_get_block); 958 } 959 960 static int 961 ext2_dax_writepages(struct address_space *mapping, struct writeback_control *wbc) 962 { 963 return dax_writeback_mapping_range(mapping, 964 mapping->host->i_sb->s_bdev, wbc); 965 } 966 967 const struct address_space_operations ext2_aops = { 968 .readpage = ext2_readpage, 969 .readpages = ext2_readpages, 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 .readpage = ext2_readpage, 983 .readpages = ext2_readpages, 984 .writepage = ext2_nobh_writepage, 985 .write_begin = ext2_nobh_write_begin, 986 .write_end = nobh_write_end, 987 .bmap = ext2_bmap, 988 .direct_IO = ext2_direct_IO, 989 .writepages = ext2_writepages, 990 .migratepage = buffer_migrate_page, 991 .error_remove_page = generic_error_remove_page, 992 }; 993 994 static const struct address_space_operations ext2_dax_aops = { 995 .writepages = ext2_dax_writepages, 996 .direct_IO = noop_direct_IO, 997 .set_page_dirty = noop_set_page_dirty, 998 .invalidatepage = noop_invalidatepage, 999 }; 1000 1001 /* 1002 * Probably it should be a library function... search for first non-zero word 1003 * or memcmp with zero_page, whatever is better for particular architecture. 1004 * Linus? 1005 */ 1006 static inline int all_zeroes(__le32 *p, __le32 *q) 1007 { 1008 while (p < q) 1009 if (*p++) 1010 return 0; 1011 return 1; 1012 } 1013 1014 /** 1015 * ext2_find_shared - find the indirect blocks for partial truncation. 1016 * @inode: inode in question 1017 * @depth: depth of the affected branch 1018 * @offsets: offsets of pointers in that branch (see ext2_block_to_path) 1019 * @chain: place to store the pointers to partial indirect blocks 1020 * @top: place to the (detached) top of branch 1021 * 1022 * This is a helper function used by ext2_truncate(). 1023 * 1024 * When we do truncate() we may have to clean the ends of several indirect 1025 * blocks but leave the blocks themselves alive. Block is partially 1026 * truncated if some data below the new i_size is referred from it (and 1027 * it is on the path to the first completely truncated data block, indeed). 1028 * We have to free the top of that path along with everything to the right 1029 * of the path. Since no allocation past the truncation point is possible 1030 * until ext2_truncate() finishes, we may safely do the latter, but top 1031 * of branch may require special attention - pageout below the truncation 1032 * point might try to populate it. 1033 * 1034 * We atomically detach the top of branch from the tree, store the block 1035 * number of its root in *@top, pointers to buffer_heads of partially 1036 * truncated blocks - in @chain[].bh and pointers to their last elements 1037 * that should not be removed - in @chain[].p. Return value is the pointer 1038 * to last filled element of @chain. 1039 * 1040 * The work left to caller to do the actual freeing of subtrees: 1041 * a) free the subtree starting from *@top 1042 * b) free the subtrees whose roots are stored in 1043 * (@chain[i].p+1 .. end of @chain[i].bh->b_data) 1044 * c) free the subtrees growing from the inode past the @chain[0].p 1045 * (no partially truncated stuff there). 1046 */ 1047 1048 static Indirect *ext2_find_shared(struct inode *inode, 1049 int depth, 1050 int offsets[4], 1051 Indirect chain[4], 1052 __le32 *top) 1053 { 1054 Indirect *partial, *p; 1055 int k, err; 1056 1057 *top = 0; 1058 for (k = depth; k > 1 && !offsets[k-1]; k--) 1059 ; 1060 partial = ext2_get_branch(inode, k, offsets, chain, &err); 1061 if (!partial) 1062 partial = chain + k-1; 1063 /* 1064 * If the branch acquired continuation since we've looked at it - 1065 * fine, it should all survive and (new) top doesn't belong to us. 1066 */ 1067 write_lock(&EXT2_I(inode)->i_meta_lock); 1068 if (!partial->key && *partial->p) { 1069 write_unlock(&EXT2_I(inode)->i_meta_lock); 1070 goto no_top; 1071 } 1072 for (p=partial; p>chain && all_zeroes((__le32*)p->bh->b_data,p->p); p--) 1073 ; 1074 /* 1075 * OK, we've found the last block that must survive. The rest of our 1076 * branch should be detached before unlocking. However, if that rest 1077 * of branch is all ours and does not grow immediately from the inode 1078 * it's easier to cheat and just decrement partial->p. 1079 */ 1080 if (p == chain + k - 1 && p > chain) { 1081 p->p--; 1082 } else { 1083 *top = *p->p; 1084 *p->p = 0; 1085 } 1086 write_unlock(&EXT2_I(inode)->i_meta_lock); 1087 1088 while(partial > p) 1089 { 1090 brelse(partial->bh); 1091 partial--; 1092 } 1093 no_top: 1094 return partial; 1095 } 1096 1097 /** 1098 * ext2_free_data - free a list of data blocks 1099 * @inode: inode we are dealing with 1100 * @p: array of block numbers 1101 * @q: points immediately past the end of array 1102 * 1103 * We are freeing all blocks referred from that array (numbers are 1104 * stored as little-endian 32-bit) and updating @inode->i_blocks 1105 * appropriately. 1106 */ 1107 static inline void ext2_free_data(struct inode *inode, __le32 *p, __le32 *q) 1108 { 1109 unsigned long block_to_free = 0, count = 0; 1110 unsigned long nr; 1111 1112 for ( ; p < q ; p++) { 1113 nr = le32_to_cpu(*p); 1114 if (nr) { 1115 *p = 0; 1116 /* accumulate blocks to free if they're contiguous */ 1117 if (count == 0) 1118 goto free_this; 1119 else if (block_to_free == nr - count) 1120 count++; 1121 else { 1122 ext2_free_blocks (inode, block_to_free, count); 1123 mark_inode_dirty(inode); 1124 free_this: 1125 block_to_free = nr; 1126 count = 1; 1127 } 1128 } 1129 } 1130 if (count > 0) { 1131 ext2_free_blocks (inode, block_to_free, count); 1132 mark_inode_dirty(inode); 1133 } 1134 } 1135 1136 /** 1137 * ext2_free_branches - free an array of branches 1138 * @inode: inode we are dealing with 1139 * @p: array of block numbers 1140 * @q: pointer immediately past the end of array 1141 * @depth: depth of the branches to free 1142 * 1143 * We are freeing all blocks referred from these branches (numbers are 1144 * stored as little-endian 32-bit) and updating @inode->i_blocks 1145 * appropriately. 1146 */ 1147 static void ext2_free_branches(struct inode *inode, __le32 *p, __le32 *q, int depth) 1148 { 1149 struct buffer_head * bh; 1150 unsigned long nr; 1151 1152 if (depth--) { 1153 int addr_per_block = EXT2_ADDR_PER_BLOCK(inode->i_sb); 1154 for ( ; p < q ; p++) { 1155 nr = le32_to_cpu(*p); 1156 if (!nr) 1157 continue; 1158 *p = 0; 1159 bh = sb_bread(inode->i_sb, nr); 1160 /* 1161 * A read failure? Report error and clear slot 1162 * (should be rare). 1163 */ 1164 if (!bh) { 1165 ext2_error(inode->i_sb, "ext2_free_branches", 1166 "Read failure, inode=%ld, block=%ld", 1167 inode->i_ino, nr); 1168 continue; 1169 } 1170 ext2_free_branches(inode, 1171 (__le32*)bh->b_data, 1172 (__le32*)bh->b_data + addr_per_block, 1173 depth); 1174 bforget(bh); 1175 ext2_free_blocks(inode, nr, 1); 1176 mark_inode_dirty(inode); 1177 } 1178 } else 1179 ext2_free_data(inode, p, q); 1180 } 1181 1182 /* dax_sem must be held when calling this function */ 1183 static void __ext2_truncate_blocks(struct inode *inode, loff_t offset) 1184 { 1185 __le32 *i_data = EXT2_I(inode)->i_data; 1186 struct ext2_inode_info *ei = EXT2_I(inode); 1187 int addr_per_block = EXT2_ADDR_PER_BLOCK(inode->i_sb); 1188 int offsets[4]; 1189 Indirect chain[4]; 1190 Indirect *partial; 1191 __le32 nr = 0; 1192 int n; 1193 long iblock; 1194 unsigned blocksize; 1195 blocksize = inode->i_sb->s_blocksize; 1196 iblock = (offset + blocksize-1) >> EXT2_BLOCK_SIZE_BITS(inode->i_sb); 1197 1198 #ifdef CONFIG_FS_DAX 1199 WARN_ON(!rwsem_is_locked(&ei->dax_sem)); 1200 #endif 1201 1202 n = ext2_block_to_path(inode, iblock, offsets, NULL); 1203 if (n == 0) 1204 return; 1205 1206 /* 1207 * From here we block out all ext2_get_block() callers who want to 1208 * modify the block allocation tree. 1209 */ 1210 mutex_lock(&ei->truncate_mutex); 1211 1212 if (n == 1) { 1213 ext2_free_data(inode, i_data+offsets[0], 1214 i_data + EXT2_NDIR_BLOCKS); 1215 goto do_indirects; 1216 } 1217 1218 partial = ext2_find_shared(inode, n, offsets, chain, &nr); 1219 /* Kill the top of shared branch (already detached) */ 1220 if (nr) { 1221 if (partial == chain) 1222 mark_inode_dirty(inode); 1223 else 1224 mark_buffer_dirty_inode(partial->bh, inode); 1225 ext2_free_branches(inode, &nr, &nr+1, (chain+n-1) - partial); 1226 } 1227 /* Clear the ends of indirect blocks on the shared branch */ 1228 while (partial > chain) { 1229 ext2_free_branches(inode, 1230 partial->p + 1, 1231 (__le32*)partial->bh->b_data+addr_per_block, 1232 (chain+n-1) - partial); 1233 mark_buffer_dirty_inode(partial->bh, inode); 1234 brelse (partial->bh); 1235 partial--; 1236 } 1237 do_indirects: 1238 /* Kill the remaining (whole) subtrees */ 1239 switch (offsets[0]) { 1240 default: 1241 nr = i_data[EXT2_IND_BLOCK]; 1242 if (nr) { 1243 i_data[EXT2_IND_BLOCK] = 0; 1244 mark_inode_dirty(inode); 1245 ext2_free_branches(inode, &nr, &nr+1, 1); 1246 } 1247 /* fall through */ 1248 case EXT2_IND_BLOCK: 1249 nr = i_data[EXT2_DIND_BLOCK]; 1250 if (nr) { 1251 i_data[EXT2_DIND_BLOCK] = 0; 1252 mark_inode_dirty(inode); 1253 ext2_free_branches(inode, &nr, &nr+1, 2); 1254 } 1255 /* fall through */ 1256 case EXT2_DIND_BLOCK: 1257 nr = i_data[EXT2_TIND_BLOCK]; 1258 if (nr) { 1259 i_data[EXT2_TIND_BLOCK] = 0; 1260 mark_inode_dirty(inode); 1261 ext2_free_branches(inode, &nr, &nr+1, 3); 1262 } 1263 case EXT2_TIND_BLOCK: 1264 ; 1265 } 1266 1267 ext2_discard_reservation(inode); 1268 1269 mutex_unlock(&ei->truncate_mutex); 1270 } 1271 1272 static void ext2_truncate_blocks(struct inode *inode, loff_t offset) 1273 { 1274 if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || 1275 S_ISLNK(inode->i_mode))) 1276 return; 1277 if (ext2_inode_is_fast_symlink(inode)) 1278 return; 1279 1280 dax_sem_down_write(EXT2_I(inode)); 1281 __ext2_truncate_blocks(inode, offset); 1282 dax_sem_up_write(EXT2_I(inode)); 1283 } 1284 1285 static int ext2_setsize(struct inode *inode, loff_t newsize) 1286 { 1287 int error; 1288 1289 if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || 1290 S_ISLNK(inode->i_mode))) 1291 return -EINVAL; 1292 if (ext2_inode_is_fast_symlink(inode)) 1293 return -EINVAL; 1294 if (IS_APPEND(inode) || IS_IMMUTABLE(inode)) 1295 return -EPERM; 1296 1297 inode_dio_wait(inode); 1298 1299 if (IS_DAX(inode)) { 1300 error = iomap_zero_range(inode, newsize, 1301 PAGE_ALIGN(newsize) - newsize, NULL, 1302 &ext2_iomap_ops); 1303 } else if (test_opt(inode->i_sb, NOBH)) 1304 error = nobh_truncate_page(inode->i_mapping, 1305 newsize, ext2_get_block); 1306 else 1307 error = block_truncate_page(inode->i_mapping, 1308 newsize, ext2_get_block); 1309 if (error) 1310 return error; 1311 1312 dax_sem_down_write(EXT2_I(inode)); 1313 truncate_setsize(inode, newsize); 1314 __ext2_truncate_blocks(inode, newsize); 1315 dax_sem_up_write(EXT2_I(inode)); 1316 1317 inode->i_mtime = inode->i_ctime = current_time(inode); 1318 if (inode_needs_sync(inode)) { 1319 sync_mapping_buffers(inode->i_mapping); 1320 sync_inode_metadata(inode, 1); 1321 } else { 1322 mark_inode_dirty(inode); 1323 } 1324 1325 return 0; 1326 } 1327 1328 static struct ext2_inode *ext2_get_inode(struct super_block *sb, ino_t ino, 1329 struct buffer_head **p) 1330 { 1331 struct buffer_head * bh; 1332 unsigned long block_group; 1333 unsigned long block; 1334 unsigned long offset; 1335 struct ext2_group_desc * gdp; 1336 1337 *p = NULL; 1338 if ((ino != EXT2_ROOT_INO && ino < EXT2_FIRST_INO(sb)) || 1339 ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count)) 1340 goto Einval; 1341 1342 block_group = (ino - 1) / EXT2_INODES_PER_GROUP(sb); 1343 gdp = ext2_get_group_desc(sb, block_group, NULL); 1344 if (!gdp) 1345 goto Egdp; 1346 /* 1347 * Figure out the offset within the block group inode table 1348 */ 1349 offset = ((ino - 1) % EXT2_INODES_PER_GROUP(sb)) * EXT2_INODE_SIZE(sb); 1350 block = le32_to_cpu(gdp->bg_inode_table) + 1351 (offset >> EXT2_BLOCK_SIZE_BITS(sb)); 1352 if (!(bh = sb_bread(sb, block))) 1353 goto Eio; 1354 1355 *p = bh; 1356 offset &= (EXT2_BLOCK_SIZE(sb) - 1); 1357 return (struct ext2_inode *) (bh->b_data + offset); 1358 1359 Einval: 1360 ext2_error(sb, "ext2_get_inode", "bad inode number: %lu", 1361 (unsigned long) ino); 1362 return ERR_PTR(-EINVAL); 1363 Eio: 1364 ext2_error(sb, "ext2_get_inode", 1365 "unable to read inode block - inode=%lu, block=%lu", 1366 (unsigned long) ino, block); 1367 Egdp: 1368 return ERR_PTR(-EIO); 1369 } 1370 1371 void ext2_set_inode_flags(struct inode *inode) 1372 { 1373 unsigned int flags = EXT2_I(inode)->i_flags; 1374 1375 inode->i_flags &= ~(S_SYNC | S_APPEND | S_IMMUTABLE | S_NOATIME | 1376 S_DIRSYNC | S_DAX); 1377 if (flags & EXT2_SYNC_FL) 1378 inode->i_flags |= S_SYNC; 1379 if (flags & EXT2_APPEND_FL) 1380 inode->i_flags |= S_APPEND; 1381 if (flags & EXT2_IMMUTABLE_FL) 1382 inode->i_flags |= S_IMMUTABLE; 1383 if (flags & EXT2_NOATIME_FL) 1384 inode->i_flags |= S_NOATIME; 1385 if (flags & EXT2_DIRSYNC_FL) 1386 inode->i_flags |= S_DIRSYNC; 1387 if (test_opt(inode->i_sb, DAX) && S_ISREG(inode->i_mode)) 1388 inode->i_flags |= S_DAX; 1389 } 1390 1391 void ext2_set_file_ops(struct inode *inode) 1392 { 1393 inode->i_op = &ext2_file_inode_operations; 1394 inode->i_fop = &ext2_file_operations; 1395 if (IS_DAX(inode)) 1396 inode->i_mapping->a_ops = &ext2_dax_aops; 1397 else if (test_opt(inode->i_sb, NOBH)) 1398 inode->i_mapping->a_ops = &ext2_nobh_aops; 1399 else 1400 inode->i_mapping->a_ops = &ext2_aops; 1401 } 1402 1403 struct inode *ext2_iget (struct super_block *sb, unsigned long ino) 1404 { 1405 struct ext2_inode_info *ei; 1406 struct buffer_head * bh = NULL; 1407 struct ext2_inode *raw_inode; 1408 struct inode *inode; 1409 long ret = -EIO; 1410 int n; 1411 uid_t i_uid; 1412 gid_t i_gid; 1413 1414 inode = iget_locked(sb, ino); 1415 if (!inode) 1416 return ERR_PTR(-ENOMEM); 1417 if (!(inode->i_state & I_NEW)) 1418 return inode; 1419 1420 ei = EXT2_I(inode); 1421 ei->i_block_alloc_info = NULL; 1422 1423 raw_inode = ext2_get_inode(inode->i_sb, ino, &bh); 1424 if (IS_ERR(raw_inode)) { 1425 ret = PTR_ERR(raw_inode); 1426 goto bad_inode; 1427 } 1428 1429 inode->i_mode = le16_to_cpu(raw_inode->i_mode); 1430 i_uid = (uid_t)le16_to_cpu(raw_inode->i_uid_low); 1431 i_gid = (gid_t)le16_to_cpu(raw_inode->i_gid_low); 1432 if (!(test_opt (inode->i_sb, NO_UID32))) { 1433 i_uid |= le16_to_cpu(raw_inode->i_uid_high) << 16; 1434 i_gid |= le16_to_cpu(raw_inode->i_gid_high) << 16; 1435 } 1436 i_uid_write(inode, i_uid); 1437 i_gid_write(inode, i_gid); 1438 set_nlink(inode, le16_to_cpu(raw_inode->i_links_count)); 1439 inode->i_size = le32_to_cpu(raw_inode->i_size); 1440 inode->i_atime.tv_sec = (signed)le32_to_cpu(raw_inode->i_atime); 1441 inode->i_ctime.tv_sec = (signed)le32_to_cpu(raw_inode->i_ctime); 1442 inode->i_mtime.tv_sec = (signed)le32_to_cpu(raw_inode->i_mtime); 1443 inode->i_atime.tv_nsec = inode->i_mtime.tv_nsec = inode->i_ctime.tv_nsec = 0; 1444 ei->i_dtime = le32_to_cpu(raw_inode->i_dtime); 1445 /* We now have enough fields to check if the inode was active or not. 1446 * This is needed because nfsd might try to access dead inodes 1447 * the test is that same one that e2fsck uses 1448 * NeilBrown 1999oct15 1449 */ 1450 if (inode->i_nlink == 0 && (inode->i_mode == 0 || ei->i_dtime)) { 1451 /* this inode is deleted */ 1452 ret = -ESTALE; 1453 goto bad_inode; 1454 } 1455 inode->i_blocks = le32_to_cpu(raw_inode->i_blocks); 1456 ei->i_flags = le32_to_cpu(raw_inode->i_flags); 1457 ext2_set_inode_flags(inode); 1458 ei->i_faddr = le32_to_cpu(raw_inode->i_faddr); 1459 ei->i_frag_no = raw_inode->i_frag; 1460 ei->i_frag_size = raw_inode->i_fsize; 1461 ei->i_file_acl = le32_to_cpu(raw_inode->i_file_acl); 1462 ei->i_dir_acl = 0; 1463 1464 if (ei->i_file_acl && 1465 !ext2_data_block_valid(EXT2_SB(sb), ei->i_file_acl, 1)) { 1466 ext2_error(sb, "ext2_iget", "bad extended attribute block %u", 1467 ei->i_file_acl); 1468 ret = -EFSCORRUPTED; 1469 goto bad_inode; 1470 } 1471 1472 if (S_ISREG(inode->i_mode)) 1473 inode->i_size |= ((__u64)le32_to_cpu(raw_inode->i_size_high)) << 32; 1474 else 1475 ei->i_dir_acl = le32_to_cpu(raw_inode->i_dir_acl); 1476 if (i_size_read(inode) < 0) { 1477 ret = -EFSCORRUPTED; 1478 goto bad_inode; 1479 } 1480 ei->i_dtime = 0; 1481 inode->i_generation = le32_to_cpu(raw_inode->i_generation); 1482 ei->i_state = 0; 1483 ei->i_block_group = (ino - 1) / EXT2_INODES_PER_GROUP(inode->i_sb); 1484 ei->i_dir_start_lookup = 0; 1485 1486 /* 1487 * NOTE! The in-memory inode i_data array is in little-endian order 1488 * even on big-endian machines: we do NOT byteswap the block numbers! 1489 */ 1490 for (n = 0; n < EXT2_N_BLOCKS; n++) 1491 ei->i_data[n] = raw_inode->i_block[n]; 1492 1493 if (S_ISREG(inode->i_mode)) { 1494 ext2_set_file_ops(inode); 1495 } else if (S_ISDIR(inode->i_mode)) { 1496 inode->i_op = &ext2_dir_inode_operations; 1497 inode->i_fop = &ext2_dir_operations; 1498 if (test_opt(inode->i_sb, NOBH)) 1499 inode->i_mapping->a_ops = &ext2_nobh_aops; 1500 else 1501 inode->i_mapping->a_ops = &ext2_aops; 1502 } else if (S_ISLNK(inode->i_mode)) { 1503 if (ext2_inode_is_fast_symlink(inode)) { 1504 inode->i_link = (char *)ei->i_data; 1505 inode->i_op = &ext2_fast_symlink_inode_operations; 1506 nd_terminate_link(ei->i_data, inode->i_size, 1507 sizeof(ei->i_data) - 1); 1508 } else { 1509 inode->i_op = &ext2_symlink_inode_operations; 1510 inode_nohighmem(inode); 1511 if (test_opt(inode->i_sb, NOBH)) 1512 inode->i_mapping->a_ops = &ext2_nobh_aops; 1513 else 1514 inode->i_mapping->a_ops = &ext2_aops; 1515 } 1516 } else { 1517 inode->i_op = &ext2_special_inode_operations; 1518 if (raw_inode->i_block[0]) 1519 init_special_inode(inode, inode->i_mode, 1520 old_decode_dev(le32_to_cpu(raw_inode->i_block[0]))); 1521 else 1522 init_special_inode(inode, inode->i_mode, 1523 new_decode_dev(le32_to_cpu(raw_inode->i_block[1]))); 1524 } 1525 brelse (bh); 1526 unlock_new_inode(inode); 1527 return inode; 1528 1529 bad_inode: 1530 brelse(bh); 1531 iget_failed(inode); 1532 return ERR_PTR(ret); 1533 } 1534 1535 static int __ext2_write_inode(struct inode *inode, int do_sync) 1536 { 1537 struct ext2_inode_info *ei = EXT2_I(inode); 1538 struct super_block *sb = inode->i_sb; 1539 ino_t ino = inode->i_ino; 1540 uid_t uid = i_uid_read(inode); 1541 gid_t gid = i_gid_read(inode); 1542 struct buffer_head * bh; 1543 struct ext2_inode * raw_inode = ext2_get_inode(sb, ino, &bh); 1544 int n; 1545 int err = 0; 1546 1547 if (IS_ERR(raw_inode)) 1548 return -EIO; 1549 1550 /* For fields not not tracking in the in-memory inode, 1551 * initialise them to zero for new inodes. */ 1552 if (ei->i_state & EXT2_STATE_NEW) 1553 memset(raw_inode, 0, EXT2_SB(sb)->s_inode_size); 1554 1555 raw_inode->i_mode = cpu_to_le16(inode->i_mode); 1556 if (!(test_opt(sb, NO_UID32))) { 1557 raw_inode->i_uid_low = cpu_to_le16(low_16_bits(uid)); 1558 raw_inode->i_gid_low = cpu_to_le16(low_16_bits(gid)); 1559 /* 1560 * Fix up interoperability with old kernels. Otherwise, old inodes get 1561 * re-used with the upper 16 bits of the uid/gid intact 1562 */ 1563 if (!ei->i_dtime) { 1564 raw_inode->i_uid_high = cpu_to_le16(high_16_bits(uid)); 1565 raw_inode->i_gid_high = cpu_to_le16(high_16_bits(gid)); 1566 } else { 1567 raw_inode->i_uid_high = 0; 1568 raw_inode->i_gid_high = 0; 1569 } 1570 } else { 1571 raw_inode->i_uid_low = cpu_to_le16(fs_high2lowuid(uid)); 1572 raw_inode->i_gid_low = cpu_to_le16(fs_high2lowgid(gid)); 1573 raw_inode->i_uid_high = 0; 1574 raw_inode->i_gid_high = 0; 1575 } 1576 raw_inode->i_links_count = cpu_to_le16(inode->i_nlink); 1577 raw_inode->i_size = cpu_to_le32(inode->i_size); 1578 raw_inode->i_atime = cpu_to_le32(inode->i_atime.tv_sec); 1579 raw_inode->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec); 1580 raw_inode->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec); 1581 1582 raw_inode->i_blocks = cpu_to_le32(inode->i_blocks); 1583 raw_inode->i_dtime = cpu_to_le32(ei->i_dtime); 1584 raw_inode->i_flags = cpu_to_le32(ei->i_flags); 1585 raw_inode->i_faddr = cpu_to_le32(ei->i_faddr); 1586 raw_inode->i_frag = ei->i_frag_no; 1587 raw_inode->i_fsize = ei->i_frag_size; 1588 raw_inode->i_file_acl = cpu_to_le32(ei->i_file_acl); 1589 if (!S_ISREG(inode->i_mode)) 1590 raw_inode->i_dir_acl = cpu_to_le32(ei->i_dir_acl); 1591 else { 1592 raw_inode->i_size_high = cpu_to_le32(inode->i_size >> 32); 1593 if (inode->i_size > 0x7fffffffULL) { 1594 if (!EXT2_HAS_RO_COMPAT_FEATURE(sb, 1595 EXT2_FEATURE_RO_COMPAT_LARGE_FILE) || 1596 EXT2_SB(sb)->s_es->s_rev_level == 1597 cpu_to_le32(EXT2_GOOD_OLD_REV)) { 1598 /* If this is the first large file 1599 * created, add a flag to the superblock. 1600 */ 1601 spin_lock(&EXT2_SB(sb)->s_lock); 1602 ext2_update_dynamic_rev(sb); 1603 EXT2_SET_RO_COMPAT_FEATURE(sb, 1604 EXT2_FEATURE_RO_COMPAT_LARGE_FILE); 1605 spin_unlock(&EXT2_SB(sb)->s_lock); 1606 ext2_sync_super(sb, EXT2_SB(sb)->s_es, 1); 1607 } 1608 } 1609 } 1610 1611 raw_inode->i_generation = cpu_to_le32(inode->i_generation); 1612 if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) { 1613 if (old_valid_dev(inode->i_rdev)) { 1614 raw_inode->i_block[0] = 1615 cpu_to_le32(old_encode_dev(inode->i_rdev)); 1616 raw_inode->i_block[1] = 0; 1617 } else { 1618 raw_inode->i_block[0] = 0; 1619 raw_inode->i_block[1] = 1620 cpu_to_le32(new_encode_dev(inode->i_rdev)); 1621 raw_inode->i_block[2] = 0; 1622 } 1623 } else for (n = 0; n < EXT2_N_BLOCKS; n++) 1624 raw_inode->i_block[n] = ei->i_data[n]; 1625 mark_buffer_dirty(bh); 1626 if (do_sync) { 1627 sync_dirty_buffer(bh); 1628 if (buffer_req(bh) && !buffer_uptodate(bh)) { 1629 printk ("IO error syncing ext2 inode [%s:%08lx]\n", 1630 sb->s_id, (unsigned long) ino); 1631 err = -EIO; 1632 } 1633 } 1634 ei->i_state &= ~EXT2_STATE_NEW; 1635 brelse (bh); 1636 return err; 1637 } 1638 1639 int ext2_write_inode(struct inode *inode, struct writeback_control *wbc) 1640 { 1641 return __ext2_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL); 1642 } 1643 1644 int ext2_getattr(const struct path *path, struct kstat *stat, 1645 u32 request_mask, unsigned int query_flags) 1646 { 1647 struct inode *inode = d_inode(path->dentry); 1648 struct ext2_inode_info *ei = EXT2_I(inode); 1649 unsigned int flags; 1650 1651 flags = ei->i_flags & EXT2_FL_USER_VISIBLE; 1652 if (flags & EXT2_APPEND_FL) 1653 stat->attributes |= STATX_ATTR_APPEND; 1654 if (flags & EXT2_COMPR_FL) 1655 stat->attributes |= STATX_ATTR_COMPRESSED; 1656 if (flags & EXT2_IMMUTABLE_FL) 1657 stat->attributes |= STATX_ATTR_IMMUTABLE; 1658 if (flags & EXT2_NODUMP_FL) 1659 stat->attributes |= STATX_ATTR_NODUMP; 1660 stat->attributes_mask |= (STATX_ATTR_APPEND | 1661 STATX_ATTR_COMPRESSED | 1662 STATX_ATTR_ENCRYPTED | 1663 STATX_ATTR_IMMUTABLE | 1664 STATX_ATTR_NODUMP); 1665 1666 generic_fillattr(inode, stat); 1667 return 0; 1668 } 1669 1670 int ext2_setattr(struct dentry *dentry, struct iattr *iattr) 1671 { 1672 struct inode *inode = d_inode(dentry); 1673 int error; 1674 1675 error = setattr_prepare(dentry, iattr); 1676 if (error) 1677 return error; 1678 1679 if (is_quota_modification(inode, iattr)) { 1680 error = dquot_initialize(inode); 1681 if (error) 1682 return error; 1683 } 1684 if ((iattr->ia_valid & ATTR_UID && !uid_eq(iattr->ia_uid, inode->i_uid)) || 1685 (iattr->ia_valid & ATTR_GID && !gid_eq(iattr->ia_gid, inode->i_gid))) { 1686 error = dquot_transfer(inode, iattr); 1687 if (error) 1688 return error; 1689 } 1690 if (iattr->ia_valid & ATTR_SIZE && iattr->ia_size != inode->i_size) { 1691 error = ext2_setsize(inode, iattr->ia_size); 1692 if (error) 1693 return error; 1694 } 1695 setattr_copy(inode, iattr); 1696 if (iattr->ia_valid & ATTR_MODE) 1697 error = posix_acl_chmod(inode, inode->i_mode); 1698 mark_inode_dirty(inode); 1699 1700 return error; 1701 } 1702