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 * @num: depth of the chain (number of blocks to allocate) 455 * @offsets: offsets (in the blocks) to store the pointers to next. 456 * @branch: place to store the chain in. 457 * 458 * This function allocates @num blocks, zeroes out all but the last one, 459 * links them into chain and (if we are synchronous) writes them to disk. 460 * In other words, it prepares a branch that can be spliced onto the 461 * inode. It stores the information about that chain in the branch[], in 462 * the same format as ext2_get_branch() would do. We are calling it after 463 * we had read the existing part of chain and partial points to the last 464 * triple of that (one with zero ->key). Upon the exit we have the same 465 * picture as after the successful ext2_get_block(), except that in one 466 * place chain is disconnected - *branch->p is still zero (we did not 467 * set the last link), but branch->key contains the number that should 468 * be placed into *branch->p to fill that gap. 469 * 470 * If allocation fails we free all blocks we've allocated (and forget 471 * their buffer_heads) and return the error value the from failed 472 * ext2_alloc_block() (normally -ENOSPC). Otherwise we set the chain 473 * as described above and return 0. 474 */ 475 476 static int ext2_alloc_branch(struct inode *inode, 477 int indirect_blks, int *blks, ext2_fsblk_t goal, 478 int *offsets, Indirect *branch) 479 { 480 int blocksize = inode->i_sb->s_blocksize; 481 int i, n = 0; 482 int err = 0; 483 struct buffer_head *bh; 484 int num; 485 ext2_fsblk_t new_blocks[4]; 486 ext2_fsblk_t current_block; 487 488 num = ext2_alloc_blocks(inode, goal, indirect_blks, 489 *blks, new_blocks, &err); 490 if (err) 491 return err; 492 493 branch[0].key = cpu_to_le32(new_blocks[0]); 494 /* 495 * metadata blocks and data blocks are allocated. 496 */ 497 for (n = 1; n <= indirect_blks; n++) { 498 /* 499 * Get buffer_head for parent block, zero it out 500 * and set the pointer to new one, then send 501 * parent to disk. 502 */ 503 bh = sb_getblk(inode->i_sb, new_blocks[n-1]); 504 if (unlikely(!bh)) { 505 err = -ENOMEM; 506 goto failed; 507 } 508 branch[n].bh = bh; 509 lock_buffer(bh); 510 memset(bh->b_data, 0, blocksize); 511 branch[n].p = (__le32 *) bh->b_data + offsets[n]; 512 branch[n].key = cpu_to_le32(new_blocks[n]); 513 *branch[n].p = branch[n].key; 514 if ( n == indirect_blks) { 515 current_block = new_blocks[n]; 516 /* 517 * End of chain, update the last new metablock of 518 * the chain to point to the new allocated 519 * data blocks numbers 520 */ 521 for (i=1; i < num; i++) 522 *(branch[n].p + i) = cpu_to_le32(++current_block); 523 } 524 set_buffer_uptodate(bh); 525 unlock_buffer(bh); 526 mark_buffer_dirty_inode(bh, inode); 527 /* We used to sync bh here if IS_SYNC(inode). 528 * But we now rely upon generic_write_sync() 529 * and b_inode_buffers. But not for directories. 530 */ 531 if (S_ISDIR(inode->i_mode) && IS_DIRSYNC(inode)) 532 sync_dirty_buffer(bh); 533 } 534 *blks = num; 535 return err; 536 537 failed: 538 for (i = 1; i < n; i++) 539 bforget(branch[i].bh); 540 for (i = 0; i < indirect_blks; i++) 541 ext2_free_blocks(inode, new_blocks[i], 1); 542 ext2_free_blocks(inode, new_blocks[i], num); 543 return err; 544 } 545 546 /** 547 * ext2_splice_branch - splice the allocated branch onto inode. 548 * @inode: owner 549 * @block: (logical) number of block we are adding 550 * @where: location of missing link 551 * @num: number of indirect blocks we are adding 552 * @blks: number of direct blocks we are adding 553 * 554 * This function fills the missing link and does all housekeeping needed in 555 * inode (->i_blocks, etc.). In case of success we end up with the full 556 * chain to new block and return 0. 557 */ 558 static void ext2_splice_branch(struct inode *inode, 559 long block, Indirect *where, int num, int blks) 560 { 561 int i; 562 struct ext2_block_alloc_info *block_i; 563 ext2_fsblk_t current_block; 564 565 block_i = EXT2_I(inode)->i_block_alloc_info; 566 567 /* XXX LOCKING probably should have i_meta_lock ?*/ 568 /* That's it */ 569 570 *where->p = where->key; 571 572 /* 573 * Update the host buffer_head or inode to point to more just allocated 574 * direct blocks blocks 575 */ 576 if (num == 0 && blks > 1) { 577 current_block = le32_to_cpu(where->key) + 1; 578 for (i = 1; i < blks; i++) 579 *(where->p + i ) = cpu_to_le32(current_block++); 580 } 581 582 /* 583 * update the most recently allocated logical & physical block 584 * in i_block_alloc_info, to assist find the proper goal block for next 585 * allocation 586 */ 587 if (block_i) { 588 block_i->last_alloc_logical_block = block + blks - 1; 589 block_i->last_alloc_physical_block = 590 le32_to_cpu(where[num].key) + blks - 1; 591 } 592 593 /* We are done with atomic stuff, now do the rest of housekeeping */ 594 595 /* had we spliced it onto indirect block? */ 596 if (where->bh) 597 mark_buffer_dirty_inode(where->bh, inode); 598 599 inode->i_ctime = current_time(inode); 600 mark_inode_dirty(inode); 601 } 602 603 /* 604 * Allocation strategy is simple: if we have to allocate something, we will 605 * have to go the whole way to leaf. So let's do it before attaching anything 606 * to tree, set linkage between the newborn blocks, write them if sync is 607 * required, recheck the path, free and repeat if check fails, otherwise 608 * set the last missing link (that will protect us from any truncate-generated 609 * removals - all blocks on the path are immune now) and possibly force the 610 * write on the parent block. 611 * That has a nice additional property: no special recovery from the failed 612 * allocations is needed - we simply release blocks and do not touch anything 613 * reachable from inode. 614 * 615 * `handle' can be NULL if create == 0. 616 * 617 * return > 0, # of blocks mapped or allocated. 618 * return = 0, if plain lookup failed. 619 * return < 0, error case. 620 */ 621 static int ext2_get_blocks(struct inode *inode, 622 sector_t iblock, unsigned long maxblocks, 623 u32 *bno, bool *new, bool *boundary, 624 int create) 625 { 626 int err; 627 int offsets[4]; 628 Indirect chain[4]; 629 Indirect *partial; 630 ext2_fsblk_t goal; 631 int indirect_blks; 632 int blocks_to_boundary = 0; 633 int depth; 634 struct ext2_inode_info *ei = EXT2_I(inode); 635 int count = 0; 636 ext2_fsblk_t first_block = 0; 637 638 BUG_ON(maxblocks == 0); 639 640 depth = ext2_block_to_path(inode,iblock,offsets,&blocks_to_boundary); 641 642 if (depth == 0) 643 return -EIO; 644 645 partial = ext2_get_branch(inode, depth, offsets, chain, &err); 646 /* Simplest case - block found, no allocation needed */ 647 if (!partial) { 648 first_block = le32_to_cpu(chain[depth - 1].key); 649 count++; 650 /*map more blocks*/ 651 while (count < maxblocks && count <= blocks_to_boundary) { 652 ext2_fsblk_t blk; 653 654 if (!verify_chain(chain, chain + depth - 1)) { 655 /* 656 * Indirect block might be removed by 657 * truncate while we were reading it. 658 * Handling of that case: forget what we've 659 * got now, go to reread. 660 */ 661 err = -EAGAIN; 662 count = 0; 663 partial = chain + depth - 1; 664 break; 665 } 666 blk = le32_to_cpu(*(chain[depth-1].p + count)); 667 if (blk == first_block + count) 668 count++; 669 else 670 break; 671 } 672 if (err != -EAGAIN) 673 goto got_it; 674 } 675 676 /* Next simple case - plain lookup or failed read of indirect block */ 677 if (!create || err == -EIO) 678 goto cleanup; 679 680 mutex_lock(&ei->truncate_mutex); 681 /* 682 * If the indirect block is missing while we are reading 683 * the chain(ext2_get_branch() returns -EAGAIN err), or 684 * if the chain has been changed after we grab the semaphore, 685 * (either because another process truncated this branch, or 686 * another get_block allocated this branch) re-grab the chain to see if 687 * the request block has been allocated or not. 688 * 689 * Since we already block the truncate/other get_block 690 * at this point, we will have the current copy of the chain when we 691 * splice the branch into the tree. 692 */ 693 if (err == -EAGAIN || !verify_chain(chain, partial)) { 694 while (partial > chain) { 695 brelse(partial->bh); 696 partial--; 697 } 698 partial = ext2_get_branch(inode, depth, offsets, chain, &err); 699 if (!partial) { 700 count++; 701 mutex_unlock(&ei->truncate_mutex); 702 if (err) 703 goto cleanup; 704 goto got_it; 705 } 706 } 707 708 /* 709 * Okay, we need to do block allocation. Lazily initialize the block 710 * allocation info here if necessary 711 */ 712 if (S_ISREG(inode->i_mode) && (!ei->i_block_alloc_info)) 713 ext2_init_block_alloc_info(inode); 714 715 goal = ext2_find_goal(inode, iblock, partial); 716 717 /* the number of blocks need to allocate for [d,t]indirect blocks */ 718 indirect_blks = (chain + depth) - partial - 1; 719 /* 720 * Next look up the indirect map to count the total number of 721 * direct blocks to allocate for this branch. 722 */ 723 count = ext2_blks_to_allocate(partial, indirect_blks, 724 maxblocks, blocks_to_boundary); 725 /* 726 * XXX ???? Block out ext2_truncate while we alter the tree 727 */ 728 err = ext2_alloc_branch(inode, indirect_blks, &count, goal, 729 offsets + (partial - chain), partial); 730 731 if (err) { 732 mutex_unlock(&ei->truncate_mutex); 733 goto cleanup; 734 } 735 736 if (IS_DAX(inode)) { 737 /* 738 * We must unmap blocks before zeroing so that writeback cannot 739 * overwrite zeros with stale data from block device page cache. 740 */ 741 clean_bdev_aliases(inode->i_sb->s_bdev, 742 le32_to_cpu(chain[depth-1].key), 743 count); 744 /* 745 * block must be initialised before we put it in the tree 746 * so that it's not found by another thread before it's 747 * initialised 748 */ 749 err = sb_issue_zeroout(inode->i_sb, 750 le32_to_cpu(chain[depth-1].key), count, 751 GFP_NOFS); 752 if (err) { 753 mutex_unlock(&ei->truncate_mutex); 754 goto cleanup; 755 } 756 } 757 *new = true; 758 759 ext2_splice_branch(inode, iblock, partial, indirect_blks, count); 760 mutex_unlock(&ei->truncate_mutex); 761 got_it: 762 if (count > blocks_to_boundary) 763 *boundary = true; 764 err = count; 765 /* Clean up and exit */ 766 partial = chain + depth - 1; /* the whole chain */ 767 cleanup: 768 while (partial > chain) { 769 brelse(partial->bh); 770 partial--; 771 } 772 if (err > 0) 773 *bno = le32_to_cpu(chain[depth-1].key); 774 return err; 775 } 776 777 int ext2_get_block(struct inode *inode, sector_t iblock, 778 struct buffer_head *bh_result, int create) 779 { 780 unsigned max_blocks = bh_result->b_size >> inode->i_blkbits; 781 bool new = false, boundary = false; 782 u32 bno; 783 int ret; 784 785 ret = ext2_get_blocks(inode, iblock, max_blocks, &bno, &new, &boundary, 786 create); 787 if (ret <= 0) 788 return ret; 789 790 map_bh(bh_result, inode->i_sb, bno); 791 bh_result->b_size = (ret << inode->i_blkbits); 792 if (new) 793 set_buffer_new(bh_result); 794 if (boundary) 795 set_buffer_boundary(bh_result); 796 return 0; 797 798 } 799 800 #ifdef CONFIG_FS_DAX 801 static int ext2_iomap_begin(struct inode *inode, loff_t offset, loff_t length, 802 unsigned flags, struct iomap *iomap) 803 { 804 unsigned int blkbits = inode->i_blkbits; 805 unsigned long first_block = offset >> blkbits; 806 unsigned long max_blocks = (length + (1 << blkbits) - 1) >> blkbits; 807 struct ext2_sb_info *sbi = EXT2_SB(inode->i_sb); 808 bool new = false, boundary = false; 809 u32 bno; 810 int ret; 811 812 ret = ext2_get_blocks(inode, first_block, max_blocks, 813 &bno, &new, &boundary, flags & IOMAP_WRITE); 814 if (ret < 0) 815 return ret; 816 817 iomap->flags = 0; 818 iomap->bdev = inode->i_sb->s_bdev; 819 iomap->offset = (u64)first_block << blkbits; 820 iomap->dax_dev = sbi->s_daxdev; 821 822 if (ret == 0) { 823 iomap->type = IOMAP_HOLE; 824 iomap->addr = IOMAP_NULL_ADDR; 825 iomap->length = 1 << blkbits; 826 } else { 827 iomap->type = IOMAP_MAPPED; 828 iomap->addr = (u64)bno << blkbits; 829 iomap->length = (u64)ret << blkbits; 830 iomap->flags |= IOMAP_F_MERGED; 831 } 832 833 if (new) 834 iomap->flags |= IOMAP_F_NEW; 835 return 0; 836 } 837 838 static int 839 ext2_iomap_end(struct inode *inode, loff_t offset, loff_t length, 840 ssize_t written, unsigned flags, struct iomap *iomap) 841 { 842 if (iomap->type == IOMAP_MAPPED && 843 written < length && 844 (flags & IOMAP_WRITE)) 845 ext2_write_failed(inode->i_mapping, offset + length); 846 return 0; 847 } 848 849 const struct iomap_ops ext2_iomap_ops = { 850 .iomap_begin = ext2_iomap_begin, 851 .iomap_end = ext2_iomap_end, 852 }; 853 #else 854 /* Define empty ops for !CONFIG_FS_DAX case to avoid ugly ifdefs */ 855 const struct iomap_ops ext2_iomap_ops; 856 #endif /* CONFIG_FS_DAX */ 857 858 int ext2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, 859 u64 start, u64 len) 860 { 861 return generic_block_fiemap(inode, fieinfo, start, len, 862 ext2_get_block); 863 } 864 865 static int ext2_writepage(struct page *page, struct writeback_control *wbc) 866 { 867 return block_write_full_page(page, ext2_get_block, wbc); 868 } 869 870 static int ext2_readpage(struct file *file, struct page *page) 871 { 872 return mpage_readpage(page, ext2_get_block); 873 } 874 875 static int 876 ext2_readpages(struct file *file, struct address_space *mapping, 877 struct list_head *pages, unsigned nr_pages) 878 { 879 return mpage_readpages(mapping, pages, nr_pages, ext2_get_block); 880 } 881 882 static int 883 ext2_write_begin(struct file *file, struct address_space *mapping, 884 loff_t pos, unsigned len, unsigned flags, 885 struct page **pagep, void **fsdata) 886 { 887 int ret; 888 889 ret = block_write_begin(mapping, pos, len, flags, pagep, 890 ext2_get_block); 891 if (ret < 0) 892 ext2_write_failed(mapping, pos + len); 893 return ret; 894 } 895 896 static int ext2_write_end(struct file *file, struct address_space *mapping, 897 loff_t pos, unsigned len, unsigned copied, 898 struct page *page, void *fsdata) 899 { 900 int ret; 901 902 ret = generic_write_end(file, mapping, pos, len, copied, page, fsdata); 903 if (ret < len) 904 ext2_write_failed(mapping, pos + len); 905 return ret; 906 } 907 908 static int 909 ext2_nobh_write_begin(struct file *file, struct address_space *mapping, 910 loff_t pos, unsigned len, unsigned flags, 911 struct page **pagep, void **fsdata) 912 { 913 int ret; 914 915 ret = nobh_write_begin(mapping, pos, len, flags, pagep, fsdata, 916 ext2_get_block); 917 if (ret < 0) 918 ext2_write_failed(mapping, pos + len); 919 return ret; 920 } 921 922 static int ext2_nobh_writepage(struct page *page, 923 struct writeback_control *wbc) 924 { 925 return nobh_writepage(page, ext2_get_block, wbc); 926 } 927 928 static sector_t ext2_bmap(struct address_space *mapping, sector_t block) 929 { 930 return generic_block_bmap(mapping,block,ext2_get_block); 931 } 932 933 static ssize_t 934 ext2_direct_IO(struct kiocb *iocb, struct iov_iter *iter) 935 { 936 struct file *file = iocb->ki_filp; 937 struct address_space *mapping = file->f_mapping; 938 struct inode *inode = mapping->host; 939 size_t count = iov_iter_count(iter); 940 loff_t offset = iocb->ki_pos; 941 ssize_t ret; 942 943 ret = blockdev_direct_IO(iocb, inode, iter, ext2_get_block); 944 if (ret < 0 && iov_iter_rw(iter) == WRITE) 945 ext2_write_failed(mapping, offset + count); 946 return ret; 947 } 948 949 static int 950 ext2_writepages(struct address_space *mapping, struct writeback_control *wbc) 951 { 952 return mpage_writepages(mapping, wbc, ext2_get_block); 953 } 954 955 static int 956 ext2_dax_writepages(struct address_space *mapping, struct writeback_control *wbc) 957 { 958 return dax_writeback_mapping_range(mapping, 959 mapping->host->i_sb->s_bdev, wbc); 960 } 961 962 const struct address_space_operations ext2_aops = { 963 .readpage = ext2_readpage, 964 .readpages = ext2_readpages, 965 .writepage = ext2_writepage, 966 .write_begin = ext2_write_begin, 967 .write_end = ext2_write_end, 968 .bmap = ext2_bmap, 969 .direct_IO = ext2_direct_IO, 970 .writepages = ext2_writepages, 971 .migratepage = buffer_migrate_page, 972 .is_partially_uptodate = block_is_partially_uptodate, 973 .error_remove_page = generic_error_remove_page, 974 }; 975 976 const struct address_space_operations ext2_nobh_aops = { 977 .readpage = ext2_readpage, 978 .readpages = ext2_readpages, 979 .writepage = ext2_nobh_writepage, 980 .write_begin = ext2_nobh_write_begin, 981 .write_end = nobh_write_end, 982 .bmap = ext2_bmap, 983 .direct_IO = ext2_direct_IO, 984 .writepages = ext2_writepages, 985 .migratepage = buffer_migrate_page, 986 .error_remove_page = generic_error_remove_page, 987 }; 988 989 static const struct address_space_operations ext2_dax_aops = { 990 .writepages = ext2_dax_writepages, 991 .direct_IO = noop_direct_IO, 992 .set_page_dirty = noop_set_page_dirty, 993 .invalidatepage = noop_invalidatepage, 994 }; 995 996 /* 997 * Probably it should be a library function... search for first non-zero word 998 * or memcmp with zero_page, whatever is better for particular architecture. 999 * Linus? 1000 */ 1001 static inline int all_zeroes(__le32 *p, __le32 *q) 1002 { 1003 while (p < q) 1004 if (*p++) 1005 return 0; 1006 return 1; 1007 } 1008 1009 /** 1010 * ext2_find_shared - find the indirect blocks for partial truncation. 1011 * @inode: inode in question 1012 * @depth: depth of the affected branch 1013 * @offsets: offsets of pointers in that branch (see ext2_block_to_path) 1014 * @chain: place to store the pointers to partial indirect blocks 1015 * @top: place to the (detached) top of branch 1016 * 1017 * This is a helper function used by ext2_truncate(). 1018 * 1019 * When we do truncate() we may have to clean the ends of several indirect 1020 * blocks but leave the blocks themselves alive. Block is partially 1021 * truncated if some data below the new i_size is referred from it (and 1022 * it is on the path to the first completely truncated data block, indeed). 1023 * We have to free the top of that path along with everything to the right 1024 * of the path. Since no allocation past the truncation point is possible 1025 * until ext2_truncate() finishes, we may safely do the latter, but top 1026 * of branch may require special attention - pageout below the truncation 1027 * point might try to populate it. 1028 * 1029 * We atomically detach the top of branch from the tree, store the block 1030 * number of its root in *@top, pointers to buffer_heads of partially 1031 * truncated blocks - in @chain[].bh and pointers to their last elements 1032 * that should not be removed - in @chain[].p. Return value is the pointer 1033 * to last filled element of @chain. 1034 * 1035 * The work left to caller to do the actual freeing of subtrees: 1036 * a) free the subtree starting from *@top 1037 * b) free the subtrees whose roots are stored in 1038 * (@chain[i].p+1 .. end of @chain[i].bh->b_data) 1039 * c) free the subtrees growing from the inode past the @chain[0].p 1040 * (no partially truncated stuff there). 1041 */ 1042 1043 static Indirect *ext2_find_shared(struct inode *inode, 1044 int depth, 1045 int offsets[4], 1046 Indirect chain[4], 1047 __le32 *top) 1048 { 1049 Indirect *partial, *p; 1050 int k, err; 1051 1052 *top = 0; 1053 for (k = depth; k > 1 && !offsets[k-1]; k--) 1054 ; 1055 partial = ext2_get_branch(inode, k, offsets, chain, &err); 1056 if (!partial) 1057 partial = chain + k-1; 1058 /* 1059 * If the branch acquired continuation since we've looked at it - 1060 * fine, it should all survive and (new) top doesn't belong to us. 1061 */ 1062 write_lock(&EXT2_I(inode)->i_meta_lock); 1063 if (!partial->key && *partial->p) { 1064 write_unlock(&EXT2_I(inode)->i_meta_lock); 1065 goto no_top; 1066 } 1067 for (p=partial; p>chain && all_zeroes((__le32*)p->bh->b_data,p->p); p--) 1068 ; 1069 /* 1070 * OK, we've found the last block that must survive. The rest of our 1071 * branch should be detached before unlocking. However, if that rest 1072 * of branch is all ours and does not grow immediately from the inode 1073 * it's easier to cheat and just decrement partial->p. 1074 */ 1075 if (p == chain + k - 1 && p > chain) { 1076 p->p--; 1077 } else { 1078 *top = *p->p; 1079 *p->p = 0; 1080 } 1081 write_unlock(&EXT2_I(inode)->i_meta_lock); 1082 1083 while(partial > p) 1084 { 1085 brelse(partial->bh); 1086 partial--; 1087 } 1088 no_top: 1089 return partial; 1090 } 1091 1092 /** 1093 * ext2_free_data - free a list of data blocks 1094 * @inode: inode we are dealing with 1095 * @p: array of block numbers 1096 * @q: points immediately past the end of array 1097 * 1098 * We are freeing all blocks referred from that array (numbers are 1099 * stored as little-endian 32-bit) and updating @inode->i_blocks 1100 * appropriately. 1101 */ 1102 static inline void ext2_free_data(struct inode *inode, __le32 *p, __le32 *q) 1103 { 1104 unsigned long block_to_free = 0, count = 0; 1105 unsigned long nr; 1106 1107 for ( ; p < q ; p++) { 1108 nr = le32_to_cpu(*p); 1109 if (nr) { 1110 *p = 0; 1111 /* accumulate blocks to free if they're contiguous */ 1112 if (count == 0) 1113 goto free_this; 1114 else if (block_to_free == nr - count) 1115 count++; 1116 else { 1117 ext2_free_blocks (inode, block_to_free, count); 1118 mark_inode_dirty(inode); 1119 free_this: 1120 block_to_free = nr; 1121 count = 1; 1122 } 1123 } 1124 } 1125 if (count > 0) { 1126 ext2_free_blocks (inode, block_to_free, count); 1127 mark_inode_dirty(inode); 1128 } 1129 } 1130 1131 /** 1132 * ext2_free_branches - free an array of branches 1133 * @inode: inode we are dealing with 1134 * @p: array of block numbers 1135 * @q: pointer immediately past the end of array 1136 * @depth: depth of the branches to free 1137 * 1138 * We are freeing all blocks referred from these branches (numbers are 1139 * stored as little-endian 32-bit) and updating @inode->i_blocks 1140 * appropriately. 1141 */ 1142 static void ext2_free_branches(struct inode *inode, __le32 *p, __le32 *q, int depth) 1143 { 1144 struct buffer_head * bh; 1145 unsigned long nr; 1146 1147 if (depth--) { 1148 int addr_per_block = EXT2_ADDR_PER_BLOCK(inode->i_sb); 1149 for ( ; p < q ; p++) { 1150 nr = le32_to_cpu(*p); 1151 if (!nr) 1152 continue; 1153 *p = 0; 1154 bh = sb_bread(inode->i_sb, nr); 1155 /* 1156 * A read failure? Report error and clear slot 1157 * (should be rare). 1158 */ 1159 if (!bh) { 1160 ext2_error(inode->i_sb, "ext2_free_branches", 1161 "Read failure, inode=%ld, block=%ld", 1162 inode->i_ino, nr); 1163 continue; 1164 } 1165 ext2_free_branches(inode, 1166 (__le32*)bh->b_data, 1167 (__le32*)bh->b_data + addr_per_block, 1168 depth); 1169 bforget(bh); 1170 ext2_free_blocks(inode, nr, 1); 1171 mark_inode_dirty(inode); 1172 } 1173 } else 1174 ext2_free_data(inode, p, q); 1175 } 1176 1177 /* dax_sem must be held when calling this function */ 1178 static void __ext2_truncate_blocks(struct inode *inode, loff_t offset) 1179 { 1180 __le32 *i_data = EXT2_I(inode)->i_data; 1181 struct ext2_inode_info *ei = EXT2_I(inode); 1182 int addr_per_block = EXT2_ADDR_PER_BLOCK(inode->i_sb); 1183 int offsets[4]; 1184 Indirect chain[4]; 1185 Indirect *partial; 1186 __le32 nr = 0; 1187 int n; 1188 long iblock; 1189 unsigned blocksize; 1190 blocksize = inode->i_sb->s_blocksize; 1191 iblock = (offset + blocksize-1) >> EXT2_BLOCK_SIZE_BITS(inode->i_sb); 1192 1193 #ifdef CONFIG_FS_DAX 1194 WARN_ON(!rwsem_is_locked(&ei->dax_sem)); 1195 #endif 1196 1197 n = ext2_block_to_path(inode, iblock, offsets, NULL); 1198 if (n == 0) 1199 return; 1200 1201 /* 1202 * From here we block out all ext2_get_block() callers who want to 1203 * modify the block allocation tree. 1204 */ 1205 mutex_lock(&ei->truncate_mutex); 1206 1207 if (n == 1) { 1208 ext2_free_data(inode, i_data+offsets[0], 1209 i_data + EXT2_NDIR_BLOCKS); 1210 goto do_indirects; 1211 } 1212 1213 partial = ext2_find_shared(inode, n, offsets, chain, &nr); 1214 /* Kill the top of shared branch (already detached) */ 1215 if (nr) { 1216 if (partial == chain) 1217 mark_inode_dirty(inode); 1218 else 1219 mark_buffer_dirty_inode(partial->bh, inode); 1220 ext2_free_branches(inode, &nr, &nr+1, (chain+n-1) - partial); 1221 } 1222 /* Clear the ends of indirect blocks on the shared branch */ 1223 while (partial > chain) { 1224 ext2_free_branches(inode, 1225 partial->p + 1, 1226 (__le32*)partial->bh->b_data+addr_per_block, 1227 (chain+n-1) - partial); 1228 mark_buffer_dirty_inode(partial->bh, inode); 1229 brelse (partial->bh); 1230 partial--; 1231 } 1232 do_indirects: 1233 /* Kill the remaining (whole) subtrees */ 1234 switch (offsets[0]) { 1235 default: 1236 nr = i_data[EXT2_IND_BLOCK]; 1237 if (nr) { 1238 i_data[EXT2_IND_BLOCK] = 0; 1239 mark_inode_dirty(inode); 1240 ext2_free_branches(inode, &nr, &nr+1, 1); 1241 } 1242 /* fall through */ 1243 case EXT2_IND_BLOCK: 1244 nr = i_data[EXT2_DIND_BLOCK]; 1245 if (nr) { 1246 i_data[EXT2_DIND_BLOCK] = 0; 1247 mark_inode_dirty(inode); 1248 ext2_free_branches(inode, &nr, &nr+1, 2); 1249 } 1250 /* fall through */ 1251 case EXT2_DIND_BLOCK: 1252 nr = i_data[EXT2_TIND_BLOCK]; 1253 if (nr) { 1254 i_data[EXT2_TIND_BLOCK] = 0; 1255 mark_inode_dirty(inode); 1256 ext2_free_branches(inode, &nr, &nr+1, 3); 1257 } 1258 case EXT2_TIND_BLOCK: 1259 ; 1260 } 1261 1262 ext2_discard_reservation(inode); 1263 1264 mutex_unlock(&ei->truncate_mutex); 1265 } 1266 1267 static void ext2_truncate_blocks(struct inode *inode, loff_t offset) 1268 { 1269 if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || 1270 S_ISLNK(inode->i_mode))) 1271 return; 1272 if (ext2_inode_is_fast_symlink(inode)) 1273 return; 1274 1275 dax_sem_down_write(EXT2_I(inode)); 1276 __ext2_truncate_blocks(inode, offset); 1277 dax_sem_up_write(EXT2_I(inode)); 1278 } 1279 1280 static int ext2_setsize(struct inode *inode, loff_t newsize) 1281 { 1282 int error; 1283 1284 if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || 1285 S_ISLNK(inode->i_mode))) 1286 return -EINVAL; 1287 if (ext2_inode_is_fast_symlink(inode)) 1288 return -EINVAL; 1289 if (IS_APPEND(inode) || IS_IMMUTABLE(inode)) 1290 return -EPERM; 1291 1292 inode_dio_wait(inode); 1293 1294 if (IS_DAX(inode)) { 1295 error = iomap_zero_range(inode, newsize, 1296 PAGE_ALIGN(newsize) - newsize, NULL, 1297 &ext2_iomap_ops); 1298 } else if (test_opt(inode->i_sb, NOBH)) 1299 error = nobh_truncate_page(inode->i_mapping, 1300 newsize, ext2_get_block); 1301 else 1302 error = block_truncate_page(inode->i_mapping, 1303 newsize, ext2_get_block); 1304 if (error) 1305 return error; 1306 1307 dax_sem_down_write(EXT2_I(inode)); 1308 truncate_setsize(inode, newsize); 1309 __ext2_truncate_blocks(inode, newsize); 1310 dax_sem_up_write(EXT2_I(inode)); 1311 1312 inode->i_mtime = inode->i_ctime = current_time(inode); 1313 if (inode_needs_sync(inode)) { 1314 sync_mapping_buffers(inode->i_mapping); 1315 sync_inode_metadata(inode, 1); 1316 } else { 1317 mark_inode_dirty(inode); 1318 } 1319 1320 return 0; 1321 } 1322 1323 static struct ext2_inode *ext2_get_inode(struct super_block *sb, ino_t ino, 1324 struct buffer_head **p) 1325 { 1326 struct buffer_head * bh; 1327 unsigned long block_group; 1328 unsigned long block; 1329 unsigned long offset; 1330 struct ext2_group_desc * gdp; 1331 1332 *p = NULL; 1333 if ((ino != EXT2_ROOT_INO && ino < EXT2_FIRST_INO(sb)) || 1334 ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count)) 1335 goto Einval; 1336 1337 block_group = (ino - 1) / EXT2_INODES_PER_GROUP(sb); 1338 gdp = ext2_get_group_desc(sb, block_group, NULL); 1339 if (!gdp) 1340 goto Egdp; 1341 /* 1342 * Figure out the offset within the block group inode table 1343 */ 1344 offset = ((ino - 1) % EXT2_INODES_PER_GROUP(sb)) * EXT2_INODE_SIZE(sb); 1345 block = le32_to_cpu(gdp->bg_inode_table) + 1346 (offset >> EXT2_BLOCK_SIZE_BITS(sb)); 1347 if (!(bh = sb_bread(sb, block))) 1348 goto Eio; 1349 1350 *p = bh; 1351 offset &= (EXT2_BLOCK_SIZE(sb) - 1); 1352 return (struct ext2_inode *) (bh->b_data + offset); 1353 1354 Einval: 1355 ext2_error(sb, "ext2_get_inode", "bad inode number: %lu", 1356 (unsigned long) ino); 1357 return ERR_PTR(-EINVAL); 1358 Eio: 1359 ext2_error(sb, "ext2_get_inode", 1360 "unable to read inode block - inode=%lu, block=%lu", 1361 (unsigned long) ino, block); 1362 Egdp: 1363 return ERR_PTR(-EIO); 1364 } 1365 1366 void ext2_set_inode_flags(struct inode *inode) 1367 { 1368 unsigned int flags = EXT2_I(inode)->i_flags; 1369 1370 inode->i_flags &= ~(S_SYNC | S_APPEND | S_IMMUTABLE | S_NOATIME | 1371 S_DIRSYNC | S_DAX); 1372 if (flags & EXT2_SYNC_FL) 1373 inode->i_flags |= S_SYNC; 1374 if (flags & EXT2_APPEND_FL) 1375 inode->i_flags |= S_APPEND; 1376 if (flags & EXT2_IMMUTABLE_FL) 1377 inode->i_flags |= S_IMMUTABLE; 1378 if (flags & EXT2_NOATIME_FL) 1379 inode->i_flags |= S_NOATIME; 1380 if (flags & EXT2_DIRSYNC_FL) 1381 inode->i_flags |= S_DIRSYNC; 1382 if (test_opt(inode->i_sb, DAX) && S_ISREG(inode->i_mode)) 1383 inode->i_flags |= S_DAX; 1384 } 1385 1386 void ext2_set_file_ops(struct inode *inode) 1387 { 1388 inode->i_op = &ext2_file_inode_operations; 1389 inode->i_fop = &ext2_file_operations; 1390 if (IS_DAX(inode)) 1391 inode->i_mapping->a_ops = &ext2_dax_aops; 1392 else if (test_opt(inode->i_sb, NOBH)) 1393 inode->i_mapping->a_ops = &ext2_nobh_aops; 1394 else 1395 inode->i_mapping->a_ops = &ext2_aops; 1396 } 1397 1398 struct inode *ext2_iget (struct super_block *sb, unsigned long ino) 1399 { 1400 struct ext2_inode_info *ei; 1401 struct buffer_head * bh; 1402 struct ext2_inode *raw_inode; 1403 struct inode *inode; 1404 long ret = -EIO; 1405 int n; 1406 uid_t i_uid; 1407 gid_t i_gid; 1408 1409 inode = iget_locked(sb, ino); 1410 if (!inode) 1411 return ERR_PTR(-ENOMEM); 1412 if (!(inode->i_state & I_NEW)) 1413 return inode; 1414 1415 ei = EXT2_I(inode); 1416 ei->i_block_alloc_info = NULL; 1417 1418 raw_inode = ext2_get_inode(inode->i_sb, ino, &bh); 1419 if (IS_ERR(raw_inode)) { 1420 ret = PTR_ERR(raw_inode); 1421 goto bad_inode; 1422 } 1423 1424 inode->i_mode = le16_to_cpu(raw_inode->i_mode); 1425 i_uid = (uid_t)le16_to_cpu(raw_inode->i_uid_low); 1426 i_gid = (gid_t)le16_to_cpu(raw_inode->i_gid_low); 1427 if (!(test_opt (inode->i_sb, NO_UID32))) { 1428 i_uid |= le16_to_cpu(raw_inode->i_uid_high) << 16; 1429 i_gid |= le16_to_cpu(raw_inode->i_gid_high) << 16; 1430 } 1431 i_uid_write(inode, i_uid); 1432 i_gid_write(inode, i_gid); 1433 set_nlink(inode, le16_to_cpu(raw_inode->i_links_count)); 1434 inode->i_size = le32_to_cpu(raw_inode->i_size); 1435 inode->i_atime.tv_sec = (signed)le32_to_cpu(raw_inode->i_atime); 1436 inode->i_ctime.tv_sec = (signed)le32_to_cpu(raw_inode->i_ctime); 1437 inode->i_mtime.tv_sec = (signed)le32_to_cpu(raw_inode->i_mtime); 1438 inode->i_atime.tv_nsec = inode->i_mtime.tv_nsec = inode->i_ctime.tv_nsec = 0; 1439 ei->i_dtime = le32_to_cpu(raw_inode->i_dtime); 1440 /* We now have enough fields to check if the inode was active or not. 1441 * This is needed because nfsd might try to access dead inodes 1442 * the test is that same one that e2fsck uses 1443 * NeilBrown 1999oct15 1444 */ 1445 if (inode->i_nlink == 0 && (inode->i_mode == 0 || ei->i_dtime)) { 1446 /* this inode is deleted */ 1447 brelse (bh); 1448 ret = -ESTALE; 1449 goto bad_inode; 1450 } 1451 inode->i_blocks = le32_to_cpu(raw_inode->i_blocks); 1452 ei->i_flags = le32_to_cpu(raw_inode->i_flags); 1453 ext2_set_inode_flags(inode); 1454 ei->i_faddr = le32_to_cpu(raw_inode->i_faddr); 1455 ei->i_frag_no = raw_inode->i_frag; 1456 ei->i_frag_size = raw_inode->i_fsize; 1457 ei->i_file_acl = le32_to_cpu(raw_inode->i_file_acl); 1458 ei->i_dir_acl = 0; 1459 1460 if (ei->i_file_acl && 1461 !ext2_data_block_valid(EXT2_SB(sb), ei->i_file_acl, 1)) { 1462 ext2_error(sb, "ext2_iget", "bad extended attribute block %u", 1463 ei->i_file_acl); 1464 brelse(bh); 1465 ret = -EFSCORRUPTED; 1466 goto bad_inode; 1467 } 1468 1469 if (S_ISREG(inode->i_mode)) 1470 inode->i_size |= ((__u64)le32_to_cpu(raw_inode->i_size_high)) << 32; 1471 else 1472 ei->i_dir_acl = le32_to_cpu(raw_inode->i_dir_acl); 1473 if (i_size_read(inode) < 0) { 1474 ret = -EFSCORRUPTED; 1475 goto bad_inode; 1476 } 1477 ei->i_dtime = 0; 1478 inode->i_generation = le32_to_cpu(raw_inode->i_generation); 1479 ei->i_state = 0; 1480 ei->i_block_group = (ino - 1) / EXT2_INODES_PER_GROUP(inode->i_sb); 1481 ei->i_dir_start_lookup = 0; 1482 1483 /* 1484 * NOTE! The in-memory inode i_data array is in little-endian order 1485 * even on big-endian machines: we do NOT byteswap the block numbers! 1486 */ 1487 for (n = 0; n < EXT2_N_BLOCKS; n++) 1488 ei->i_data[n] = raw_inode->i_block[n]; 1489 1490 if (S_ISREG(inode->i_mode)) { 1491 ext2_set_file_ops(inode); 1492 } else if (S_ISDIR(inode->i_mode)) { 1493 inode->i_op = &ext2_dir_inode_operations; 1494 inode->i_fop = &ext2_dir_operations; 1495 if (test_opt(inode->i_sb, NOBH)) 1496 inode->i_mapping->a_ops = &ext2_nobh_aops; 1497 else 1498 inode->i_mapping->a_ops = &ext2_aops; 1499 } else if (S_ISLNK(inode->i_mode)) { 1500 if (ext2_inode_is_fast_symlink(inode)) { 1501 inode->i_link = (char *)ei->i_data; 1502 inode->i_op = &ext2_fast_symlink_inode_operations; 1503 nd_terminate_link(ei->i_data, inode->i_size, 1504 sizeof(ei->i_data) - 1); 1505 } else { 1506 inode->i_op = &ext2_symlink_inode_operations; 1507 inode_nohighmem(inode); 1508 if (test_opt(inode->i_sb, NOBH)) 1509 inode->i_mapping->a_ops = &ext2_nobh_aops; 1510 else 1511 inode->i_mapping->a_ops = &ext2_aops; 1512 } 1513 } else { 1514 inode->i_op = &ext2_special_inode_operations; 1515 if (raw_inode->i_block[0]) 1516 init_special_inode(inode, inode->i_mode, 1517 old_decode_dev(le32_to_cpu(raw_inode->i_block[0]))); 1518 else 1519 init_special_inode(inode, inode->i_mode, 1520 new_decode_dev(le32_to_cpu(raw_inode->i_block[1]))); 1521 } 1522 brelse (bh); 1523 unlock_new_inode(inode); 1524 return inode; 1525 1526 bad_inode: 1527 iget_failed(inode); 1528 return ERR_PTR(ret); 1529 } 1530 1531 static int __ext2_write_inode(struct inode *inode, int do_sync) 1532 { 1533 struct ext2_inode_info *ei = EXT2_I(inode); 1534 struct super_block *sb = inode->i_sb; 1535 ino_t ino = inode->i_ino; 1536 uid_t uid = i_uid_read(inode); 1537 gid_t gid = i_gid_read(inode); 1538 struct buffer_head * bh; 1539 struct ext2_inode * raw_inode = ext2_get_inode(sb, ino, &bh); 1540 int n; 1541 int err = 0; 1542 1543 if (IS_ERR(raw_inode)) 1544 return -EIO; 1545 1546 /* For fields not not tracking in the in-memory inode, 1547 * initialise them to zero for new inodes. */ 1548 if (ei->i_state & EXT2_STATE_NEW) 1549 memset(raw_inode, 0, EXT2_SB(sb)->s_inode_size); 1550 1551 raw_inode->i_mode = cpu_to_le16(inode->i_mode); 1552 if (!(test_opt(sb, NO_UID32))) { 1553 raw_inode->i_uid_low = cpu_to_le16(low_16_bits(uid)); 1554 raw_inode->i_gid_low = cpu_to_le16(low_16_bits(gid)); 1555 /* 1556 * Fix up interoperability with old kernels. Otherwise, old inodes get 1557 * re-used with the upper 16 bits of the uid/gid intact 1558 */ 1559 if (!ei->i_dtime) { 1560 raw_inode->i_uid_high = cpu_to_le16(high_16_bits(uid)); 1561 raw_inode->i_gid_high = cpu_to_le16(high_16_bits(gid)); 1562 } else { 1563 raw_inode->i_uid_high = 0; 1564 raw_inode->i_gid_high = 0; 1565 } 1566 } else { 1567 raw_inode->i_uid_low = cpu_to_le16(fs_high2lowuid(uid)); 1568 raw_inode->i_gid_low = cpu_to_le16(fs_high2lowgid(gid)); 1569 raw_inode->i_uid_high = 0; 1570 raw_inode->i_gid_high = 0; 1571 } 1572 raw_inode->i_links_count = cpu_to_le16(inode->i_nlink); 1573 raw_inode->i_size = cpu_to_le32(inode->i_size); 1574 raw_inode->i_atime = cpu_to_le32(inode->i_atime.tv_sec); 1575 raw_inode->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec); 1576 raw_inode->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec); 1577 1578 raw_inode->i_blocks = cpu_to_le32(inode->i_blocks); 1579 raw_inode->i_dtime = cpu_to_le32(ei->i_dtime); 1580 raw_inode->i_flags = cpu_to_le32(ei->i_flags); 1581 raw_inode->i_faddr = cpu_to_le32(ei->i_faddr); 1582 raw_inode->i_frag = ei->i_frag_no; 1583 raw_inode->i_fsize = ei->i_frag_size; 1584 raw_inode->i_file_acl = cpu_to_le32(ei->i_file_acl); 1585 if (!S_ISREG(inode->i_mode)) 1586 raw_inode->i_dir_acl = cpu_to_le32(ei->i_dir_acl); 1587 else { 1588 raw_inode->i_size_high = cpu_to_le32(inode->i_size >> 32); 1589 if (inode->i_size > 0x7fffffffULL) { 1590 if (!EXT2_HAS_RO_COMPAT_FEATURE(sb, 1591 EXT2_FEATURE_RO_COMPAT_LARGE_FILE) || 1592 EXT2_SB(sb)->s_es->s_rev_level == 1593 cpu_to_le32(EXT2_GOOD_OLD_REV)) { 1594 /* If this is the first large file 1595 * created, add a flag to the superblock. 1596 */ 1597 spin_lock(&EXT2_SB(sb)->s_lock); 1598 ext2_update_dynamic_rev(sb); 1599 EXT2_SET_RO_COMPAT_FEATURE(sb, 1600 EXT2_FEATURE_RO_COMPAT_LARGE_FILE); 1601 spin_unlock(&EXT2_SB(sb)->s_lock); 1602 ext2_sync_super(sb, EXT2_SB(sb)->s_es, 1); 1603 } 1604 } 1605 } 1606 1607 raw_inode->i_generation = cpu_to_le32(inode->i_generation); 1608 if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) { 1609 if (old_valid_dev(inode->i_rdev)) { 1610 raw_inode->i_block[0] = 1611 cpu_to_le32(old_encode_dev(inode->i_rdev)); 1612 raw_inode->i_block[1] = 0; 1613 } else { 1614 raw_inode->i_block[0] = 0; 1615 raw_inode->i_block[1] = 1616 cpu_to_le32(new_encode_dev(inode->i_rdev)); 1617 raw_inode->i_block[2] = 0; 1618 } 1619 } else for (n = 0; n < EXT2_N_BLOCKS; n++) 1620 raw_inode->i_block[n] = ei->i_data[n]; 1621 mark_buffer_dirty(bh); 1622 if (do_sync) { 1623 sync_dirty_buffer(bh); 1624 if (buffer_req(bh) && !buffer_uptodate(bh)) { 1625 printk ("IO error syncing ext2 inode [%s:%08lx]\n", 1626 sb->s_id, (unsigned long) ino); 1627 err = -EIO; 1628 } 1629 } 1630 ei->i_state &= ~EXT2_STATE_NEW; 1631 brelse (bh); 1632 return err; 1633 } 1634 1635 int ext2_write_inode(struct inode *inode, struct writeback_control *wbc) 1636 { 1637 return __ext2_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL); 1638 } 1639 1640 int ext2_getattr(const struct path *path, struct kstat *stat, 1641 u32 request_mask, unsigned int query_falgs) 1642 { 1643 struct inode *inode = d_inode(path->dentry); 1644 struct ext2_inode_info *ei = EXT2_I(inode); 1645 unsigned int flags; 1646 1647 flags = ei->i_flags & EXT2_FL_USER_VISIBLE; 1648 if (flags & EXT2_APPEND_FL) 1649 stat->attributes |= STATX_ATTR_APPEND; 1650 if (flags & EXT2_COMPR_FL) 1651 stat->attributes |= STATX_ATTR_COMPRESSED; 1652 if (flags & EXT2_IMMUTABLE_FL) 1653 stat->attributes |= STATX_ATTR_IMMUTABLE; 1654 if (flags & EXT2_NODUMP_FL) 1655 stat->attributes |= STATX_ATTR_NODUMP; 1656 stat->attributes_mask |= (STATX_ATTR_APPEND | 1657 STATX_ATTR_COMPRESSED | 1658 STATX_ATTR_ENCRYPTED | 1659 STATX_ATTR_IMMUTABLE | 1660 STATX_ATTR_NODUMP); 1661 1662 generic_fillattr(inode, stat); 1663 return 0; 1664 } 1665 1666 int ext2_setattr(struct dentry *dentry, struct iattr *iattr) 1667 { 1668 struct inode *inode = d_inode(dentry); 1669 int error; 1670 1671 error = setattr_prepare(dentry, iattr); 1672 if (error) 1673 return error; 1674 1675 if (is_quota_modification(inode, iattr)) { 1676 error = dquot_initialize(inode); 1677 if (error) 1678 return error; 1679 } 1680 if ((iattr->ia_valid & ATTR_UID && !uid_eq(iattr->ia_uid, inode->i_uid)) || 1681 (iattr->ia_valid & ATTR_GID && !gid_eq(iattr->ia_gid, inode->i_gid))) { 1682 error = dquot_transfer(inode, iattr); 1683 if (error) 1684 return error; 1685 } 1686 if (iattr->ia_valid & ATTR_SIZE && iattr->ia_size != inode->i_size) { 1687 error = ext2_setsize(inode, iattr->ia_size); 1688 if (error) 1689 return error; 1690 } 1691 setattr_copy(inode, iattr); 1692 if (iattr->ia_valid & ATTR_MODE) 1693 error = posix_acl_chmod(inode, inode->i_mode); 1694 mark_inode_dirty(inode); 1695 1696 return error; 1697 } 1698