1 /* 2 * linux/fs/ext2/inode.c 3 * 4 * Copyright (C) 1992, 1993, 1994, 1995 5 * Remy Card (card@masi.ibp.fr) 6 * Laboratoire MASI - Institut Blaise Pascal 7 * Universite Pierre et Marie Curie (Paris VI) 8 * 9 * from 10 * 11 * linux/fs/minix/inode.c 12 * 13 * Copyright (C) 1991, 1992 Linus Torvalds 14 * 15 * Goal-directed block allocation by Stephen Tweedie 16 * (sct@dcs.ed.ac.uk), 1993, 1998 17 * Big-endian to little-endian byte-swapping/bitmaps by 18 * David S. Miller (davem@caip.rutgers.edu), 1995 19 * 64-bit file support on 64-bit platforms by Jakub Jelinek 20 * (jj@sunsite.ms.mff.cuni.cz) 21 * 22 * Assorted race fixes, rewrite of ext2_get_block() by Al Viro, 2000 23 */ 24 25 #include <linux/time.h> 26 #include <linux/highuid.h> 27 #include <linux/pagemap.h> 28 #include <linux/dax.h> 29 #include <linux/blkdev.h> 30 #include <linux/quotaops.h> 31 #include <linux/writeback.h> 32 #include <linux/buffer_head.h> 33 #include <linux/mpage.h> 34 #include <linux/fiemap.h> 35 #include <linux/iomap.h> 36 #include <linux/namei.h> 37 #include <linux/uio.h> 38 #include "ext2.h" 39 #include "acl.h" 40 #include "xattr.h" 41 42 static int __ext2_write_inode(struct inode *inode, int do_sync); 43 44 /* 45 * Test whether an inode is a fast symlink. 46 */ 47 static inline int ext2_inode_is_fast_symlink(struct inode *inode) 48 { 49 int ea_blocks = EXT2_I(inode)->i_file_acl ? 50 (inode->i_sb->s_blocksize >> 9) : 0; 51 52 return (S_ISLNK(inode->i_mode) && 53 inode->i_blocks - ea_blocks == 0); 54 } 55 56 static void ext2_truncate_blocks(struct inode *inode, loff_t offset); 57 58 static void ext2_write_failed(struct address_space *mapping, loff_t to) 59 { 60 struct inode *inode = mapping->host; 61 62 if (to > inode->i_size) { 63 truncate_pagecache(inode, inode->i_size); 64 ext2_truncate_blocks(inode, inode->i_size); 65 } 66 } 67 68 /* 69 * Called at the last iput() if i_nlink is zero. 70 */ 71 void ext2_evict_inode(struct inode * inode) 72 { 73 struct ext2_block_alloc_info *rsv; 74 int want_delete = 0; 75 76 if (!inode->i_nlink && !is_bad_inode(inode)) { 77 want_delete = 1; 78 dquot_initialize(inode); 79 } else { 80 dquot_drop(inode); 81 } 82 83 truncate_inode_pages_final(&inode->i_data); 84 85 if (want_delete) { 86 sb_start_intwrite(inode->i_sb); 87 /* set dtime */ 88 EXT2_I(inode)->i_dtime = get_seconds(); 89 mark_inode_dirty(inode); 90 __ext2_write_inode(inode, inode_needs_sync(inode)); 91 /* truncate to 0 */ 92 inode->i_size = 0; 93 if (inode->i_blocks) 94 ext2_truncate_blocks(inode, 0); 95 ext2_xattr_delete_inode(inode); 96 } 97 98 invalidate_inode_buffers(inode); 99 clear_inode(inode); 100 101 ext2_discard_reservation(inode); 102 rsv = EXT2_I(inode)->i_block_alloc_info; 103 EXT2_I(inode)->i_block_alloc_info = NULL; 104 if (unlikely(rsv)) 105 kfree(rsv); 106 107 if (want_delete) { 108 ext2_free_inode(inode); 109 sb_end_intwrite(inode->i_sb); 110 } 111 } 112 113 typedef struct { 114 __le32 *p; 115 __le32 key; 116 struct buffer_head *bh; 117 } Indirect; 118 119 static inline void add_chain(Indirect *p, struct buffer_head *bh, __le32 *v) 120 { 121 p->key = *(p->p = v); 122 p->bh = bh; 123 } 124 125 static inline int verify_chain(Indirect *from, Indirect *to) 126 { 127 while (from <= to && from->key == *from->p) 128 from++; 129 return (from > to); 130 } 131 132 /** 133 * ext2_block_to_path - parse the block number into array of offsets 134 * @inode: inode in question (we are only interested in its superblock) 135 * @i_block: block number to be parsed 136 * @offsets: array to store the offsets in 137 * @boundary: set this non-zero if the referred-to block is likely to be 138 * followed (on disk) by an indirect block. 139 * To store the locations of file's data ext2 uses a data structure common 140 * for UNIX filesystems - tree of pointers anchored in the inode, with 141 * data blocks at leaves and indirect blocks in intermediate nodes. 142 * This function translates the block number into path in that tree - 143 * return value is the path length and @offsets[n] is the offset of 144 * pointer to (n+1)th node in the nth one. If @block is out of range 145 * (negative or too large) warning is printed and zero returned. 146 * 147 * Note: function doesn't find node addresses, so no IO is needed. All 148 * we need to know is the capacity of indirect blocks (taken from the 149 * inode->i_sb). 150 */ 151 152 /* 153 * Portability note: the last comparison (check that we fit into triple 154 * indirect block) is spelled differently, because otherwise on an 155 * architecture with 32-bit longs and 8Kb pages we might get into trouble 156 * if our filesystem had 8Kb blocks. We might use long long, but that would 157 * kill us on x86. Oh, well, at least the sign propagation does not matter - 158 * i_block would have to be negative in the very beginning, so we would not 159 * get there at all. 160 */ 161 162 static int ext2_block_to_path(struct inode *inode, 163 long i_block, int offsets[4], int *boundary) 164 { 165 int ptrs = EXT2_ADDR_PER_BLOCK(inode->i_sb); 166 int ptrs_bits = EXT2_ADDR_PER_BLOCK_BITS(inode->i_sb); 167 const long direct_blocks = EXT2_NDIR_BLOCKS, 168 indirect_blocks = ptrs, 169 double_blocks = (1 << (ptrs_bits * 2)); 170 int n = 0; 171 int final = 0; 172 173 if (i_block < 0) { 174 ext2_msg(inode->i_sb, KERN_WARNING, 175 "warning: %s: block < 0", __func__); 176 } else if (i_block < direct_blocks) { 177 offsets[n++] = i_block; 178 final = direct_blocks; 179 } else if ( (i_block -= direct_blocks) < indirect_blocks) { 180 offsets[n++] = EXT2_IND_BLOCK; 181 offsets[n++] = i_block; 182 final = ptrs; 183 } else if ((i_block -= indirect_blocks) < double_blocks) { 184 offsets[n++] = EXT2_DIND_BLOCK; 185 offsets[n++] = i_block >> ptrs_bits; 186 offsets[n++] = i_block & (ptrs - 1); 187 final = ptrs; 188 } else if (((i_block -= double_blocks) >> (ptrs_bits * 2)) < ptrs) { 189 offsets[n++] = EXT2_TIND_BLOCK; 190 offsets[n++] = i_block >> (ptrs_bits * 2); 191 offsets[n++] = (i_block >> ptrs_bits) & (ptrs - 1); 192 offsets[n++] = i_block & (ptrs - 1); 193 final = ptrs; 194 } else { 195 ext2_msg(inode->i_sb, KERN_WARNING, 196 "warning: %s: block is too big", __func__); 197 } 198 if (boundary) 199 *boundary = final - 1 - (i_block & (ptrs - 1)); 200 201 return n; 202 } 203 204 /** 205 * ext2_get_branch - read the chain of indirect blocks leading to data 206 * @inode: inode in question 207 * @depth: depth of the chain (1 - direct pointer, etc.) 208 * @offsets: offsets of pointers in inode/indirect blocks 209 * @chain: place to store the result 210 * @err: here we store the error value 211 * 212 * Function fills the array of triples <key, p, bh> and returns %NULL 213 * if everything went OK or the pointer to the last filled triple 214 * (incomplete one) otherwise. Upon the return chain[i].key contains 215 * the number of (i+1)-th block in the chain (as it is stored in memory, 216 * i.e. little-endian 32-bit), chain[i].p contains the address of that 217 * number (it points into struct inode for i==0 and into the bh->b_data 218 * for i>0) and chain[i].bh points to the buffer_head of i-th indirect 219 * block for i>0 and NULL for i==0. In other words, it holds the block 220 * numbers of the chain, addresses they were taken from (and where we can 221 * verify that chain did not change) and buffer_heads hosting these 222 * numbers. 223 * 224 * Function stops when it stumbles upon zero pointer (absent block) 225 * (pointer to last triple returned, *@err == 0) 226 * or when it gets an IO error reading an indirect block 227 * (ditto, *@err == -EIO) 228 * or when it notices that chain had been changed while it was reading 229 * (ditto, *@err == -EAGAIN) 230 * or when it reads all @depth-1 indirect blocks successfully and finds 231 * the whole chain, all way to the data (returns %NULL, *err == 0). 232 */ 233 static Indirect *ext2_get_branch(struct inode *inode, 234 int depth, 235 int *offsets, 236 Indirect chain[4], 237 int *err) 238 { 239 struct super_block *sb = inode->i_sb; 240 Indirect *p = chain; 241 struct buffer_head *bh; 242 243 *err = 0; 244 /* i_data is not going away, no lock needed */ 245 add_chain (chain, NULL, EXT2_I(inode)->i_data + *offsets); 246 if (!p->key) 247 goto no_block; 248 while (--depth) { 249 bh = sb_bread(sb, le32_to_cpu(p->key)); 250 if (!bh) 251 goto failure; 252 read_lock(&EXT2_I(inode)->i_meta_lock); 253 if (!verify_chain(chain, p)) 254 goto changed; 255 add_chain(++p, bh, (__le32*)bh->b_data + *++offsets); 256 read_unlock(&EXT2_I(inode)->i_meta_lock); 257 if (!p->key) 258 goto no_block; 259 } 260 return NULL; 261 262 changed: 263 read_unlock(&EXT2_I(inode)->i_meta_lock); 264 brelse(bh); 265 *err = -EAGAIN; 266 goto no_block; 267 failure: 268 *err = -EIO; 269 no_block: 270 return p; 271 } 272 273 /** 274 * ext2_find_near - find a place for allocation with sufficient locality 275 * @inode: owner 276 * @ind: descriptor of indirect block. 277 * 278 * This function returns the preferred place for block allocation. 279 * It is used when heuristic for sequential allocation fails. 280 * Rules are: 281 * + if there is a block to the left of our position - allocate near it. 282 * + if pointer will live in indirect block - allocate near that block. 283 * + if pointer will live in inode - allocate in the same cylinder group. 284 * 285 * In the latter case we colour the starting block by the callers PID to 286 * prevent it from clashing with concurrent allocations for a different inode 287 * in the same block group. The PID is used here so that functionally related 288 * files will be close-by on-disk. 289 * 290 * Caller must make sure that @ind is valid and will stay that way. 291 */ 292 293 static ext2_fsblk_t ext2_find_near(struct inode *inode, Indirect *ind) 294 { 295 struct ext2_inode_info *ei = EXT2_I(inode); 296 __le32 *start = ind->bh ? (__le32 *) ind->bh->b_data : ei->i_data; 297 __le32 *p; 298 ext2_fsblk_t bg_start; 299 ext2_fsblk_t colour; 300 301 /* Try to find previous block */ 302 for (p = ind->p - 1; p >= start; p--) 303 if (*p) 304 return le32_to_cpu(*p); 305 306 /* No such thing, so let's try location of indirect block */ 307 if (ind->bh) 308 return ind->bh->b_blocknr; 309 310 /* 311 * It is going to be referred from inode itself? OK, just put it into 312 * the same cylinder group then. 313 */ 314 bg_start = ext2_group_first_block_no(inode->i_sb, ei->i_block_group); 315 colour = (current->pid % 16) * 316 (EXT2_BLOCKS_PER_GROUP(inode->i_sb) / 16); 317 return bg_start + colour; 318 } 319 320 /** 321 * ext2_find_goal - find a preferred place for allocation. 322 * @inode: owner 323 * @block: block we want 324 * @partial: pointer to the last triple within a chain 325 * 326 * Returns preferred place for a block (the goal). 327 */ 328 329 static inline ext2_fsblk_t ext2_find_goal(struct inode *inode, long block, 330 Indirect *partial) 331 { 332 struct ext2_block_alloc_info *block_i; 333 334 block_i = EXT2_I(inode)->i_block_alloc_info; 335 336 /* 337 * try the heuristic for sequential allocation, 338 * failing that at least try to get decent locality. 339 */ 340 if (block_i && (block == block_i->last_alloc_logical_block + 1) 341 && (block_i->last_alloc_physical_block != 0)) { 342 return block_i->last_alloc_physical_block + 1; 343 } 344 345 return ext2_find_near(inode, partial); 346 } 347 348 /** 349 * ext2_blks_to_allocate: Look up the block map and count the number 350 * of direct blocks need to be allocated for the given branch. 351 * 352 * @branch: chain of indirect blocks 353 * @k: number of blocks need for indirect blocks 354 * @blks: number of data blocks to be mapped. 355 * @blocks_to_boundary: the offset in the indirect block 356 * 357 * return the total number of blocks to be allocate, including the 358 * direct and indirect blocks. 359 */ 360 static int 361 ext2_blks_to_allocate(Indirect * branch, int k, unsigned long blks, 362 int blocks_to_boundary) 363 { 364 unsigned long count = 0; 365 366 /* 367 * Simple case, [t,d]Indirect block(s) has not allocated yet 368 * then it's clear blocks on that path have not allocated 369 */ 370 if (k > 0) { 371 /* right now don't hanel cross boundary allocation */ 372 if (blks < blocks_to_boundary + 1) 373 count += blks; 374 else 375 count += blocks_to_boundary + 1; 376 return count; 377 } 378 379 count++; 380 while (count < blks && count <= blocks_to_boundary 381 && le32_to_cpu(*(branch[0].p + count)) == 0) { 382 count++; 383 } 384 return count; 385 } 386 387 /** 388 * ext2_alloc_blocks: multiple allocate blocks needed for a branch 389 * @indirect_blks: the number of blocks need to allocate for indirect 390 * blocks 391 * 392 * @new_blocks: on return it will store the new block numbers for 393 * the indirect blocks(if needed) and the first direct block, 394 * @blks: on return it will store the total number of allocated 395 * direct blocks 396 */ 397 static int ext2_alloc_blocks(struct inode *inode, 398 ext2_fsblk_t goal, int indirect_blks, int blks, 399 ext2_fsblk_t new_blocks[4], int *err) 400 { 401 int target, i; 402 unsigned long count = 0; 403 int index = 0; 404 ext2_fsblk_t current_block = 0; 405 int ret = 0; 406 407 /* 408 * Here we try to allocate the requested multiple blocks at once, 409 * on a best-effort basis. 410 * To build a branch, we should allocate blocks for 411 * the indirect blocks(if not allocated yet), and at least 412 * the first direct block of this branch. That's the 413 * minimum number of blocks need to allocate(required) 414 */ 415 target = blks + indirect_blks; 416 417 while (1) { 418 count = target; 419 /* allocating blocks for indirect blocks and direct blocks */ 420 current_block = ext2_new_blocks(inode,goal,&count,err); 421 if (*err) 422 goto failed_out; 423 424 target -= count; 425 /* allocate blocks for indirect blocks */ 426 while (index < indirect_blks && count) { 427 new_blocks[index++] = current_block++; 428 count--; 429 } 430 431 if (count > 0) 432 break; 433 } 434 435 /* save the new block number for the first direct block */ 436 new_blocks[index] = current_block; 437 438 /* total number of blocks allocated for direct blocks */ 439 ret = count; 440 *err = 0; 441 return ret; 442 failed_out: 443 for (i = 0; i <index; i++) 444 ext2_free_blocks(inode, new_blocks[i], 1); 445 if (index) 446 mark_inode_dirty(inode); 447 return ret; 448 } 449 450 /** 451 * ext2_alloc_branch - allocate and set up a chain of blocks. 452 * @inode: owner 453 * @num: depth of the chain (number of blocks to allocate) 454 * @offsets: offsets (in the blocks) to store the pointers to next. 455 * @branch: place to store the chain in. 456 * 457 * This function allocates @num blocks, zeroes out all but the last one, 458 * links them into chain and (if we are synchronous) writes them to disk. 459 * In other words, it prepares a branch that can be spliced onto the 460 * inode. It stores the information about that chain in the branch[], in 461 * the same format as ext2_get_branch() would do. We are calling it after 462 * we had read the existing part of chain and partial points to the last 463 * triple of that (one with zero ->key). Upon the exit we have the same 464 * picture as after the successful ext2_get_block(), except that in one 465 * place chain is disconnected - *branch->p is still zero (we did not 466 * set the last link), but branch->key contains the number that should 467 * be placed into *branch->p to fill that gap. 468 * 469 * If allocation fails we free all blocks we've allocated (and forget 470 * their buffer_heads) and return the error value the from failed 471 * ext2_alloc_block() (normally -ENOSPC). Otherwise we set the chain 472 * as described above and return 0. 473 */ 474 475 static int ext2_alloc_branch(struct inode *inode, 476 int indirect_blks, int *blks, ext2_fsblk_t goal, 477 int *offsets, Indirect *branch) 478 { 479 int blocksize = inode->i_sb->s_blocksize; 480 int i, n = 0; 481 int err = 0; 482 struct buffer_head *bh; 483 int num; 484 ext2_fsblk_t new_blocks[4]; 485 ext2_fsblk_t current_block; 486 487 num = ext2_alloc_blocks(inode, goal, indirect_blks, 488 *blks, new_blocks, &err); 489 if (err) 490 return err; 491 492 branch[0].key = cpu_to_le32(new_blocks[0]); 493 /* 494 * metadata blocks and data blocks are allocated. 495 */ 496 for (n = 1; n <= indirect_blks; n++) { 497 /* 498 * Get buffer_head for parent block, zero it out 499 * and set the pointer to new one, then send 500 * parent to disk. 501 */ 502 bh = sb_getblk(inode->i_sb, new_blocks[n-1]); 503 if (unlikely(!bh)) { 504 err = -ENOMEM; 505 goto failed; 506 } 507 branch[n].bh = bh; 508 lock_buffer(bh); 509 memset(bh->b_data, 0, blocksize); 510 branch[n].p = (__le32 *) bh->b_data + offsets[n]; 511 branch[n].key = cpu_to_le32(new_blocks[n]); 512 *branch[n].p = branch[n].key; 513 if ( n == indirect_blks) { 514 current_block = new_blocks[n]; 515 /* 516 * End of chain, update the last new metablock of 517 * the chain to point to the new allocated 518 * data blocks numbers 519 */ 520 for (i=1; i < num; i++) 521 *(branch[n].p + i) = cpu_to_le32(++current_block); 522 } 523 set_buffer_uptodate(bh); 524 unlock_buffer(bh); 525 mark_buffer_dirty_inode(bh, inode); 526 /* We used to sync bh here if IS_SYNC(inode). 527 * But we now rely upon generic_write_sync() 528 * and b_inode_buffers. But not for directories. 529 */ 530 if (S_ISDIR(inode->i_mode) && IS_DIRSYNC(inode)) 531 sync_dirty_buffer(bh); 532 } 533 *blks = num; 534 return err; 535 536 failed: 537 for (i = 1; i < n; i++) 538 bforget(branch[i].bh); 539 for (i = 0; i < indirect_blks; i++) 540 ext2_free_blocks(inode, new_blocks[i], 1); 541 ext2_free_blocks(inode, new_blocks[i], num); 542 return err; 543 } 544 545 /** 546 * ext2_splice_branch - splice the allocated branch onto inode. 547 * @inode: owner 548 * @block: (logical) number of block we are adding 549 * @where: location of missing link 550 * @num: number of indirect blocks we are adding 551 * @blks: number of direct blocks we are adding 552 * 553 * This function fills the missing link and does all housekeeping needed in 554 * inode (->i_blocks, etc.). In case of success we end up with the full 555 * chain to new block and return 0. 556 */ 557 static void ext2_splice_branch(struct inode *inode, 558 long block, Indirect *where, int num, int blks) 559 { 560 int i; 561 struct ext2_block_alloc_info *block_i; 562 ext2_fsblk_t current_block; 563 564 block_i = EXT2_I(inode)->i_block_alloc_info; 565 566 /* XXX LOCKING probably should have i_meta_lock ?*/ 567 /* That's it */ 568 569 *where->p = where->key; 570 571 /* 572 * Update the host buffer_head or inode to point to more just allocated 573 * direct blocks blocks 574 */ 575 if (num == 0 && blks > 1) { 576 current_block = le32_to_cpu(where->key) + 1; 577 for (i = 1; i < blks; i++) 578 *(where->p + i ) = cpu_to_le32(current_block++); 579 } 580 581 /* 582 * update the most recently allocated logical & physical block 583 * in i_block_alloc_info, to assist find the proper goal block for next 584 * allocation 585 */ 586 if (block_i) { 587 block_i->last_alloc_logical_block = block + blks - 1; 588 block_i->last_alloc_physical_block = 589 le32_to_cpu(where[num].key) + blks - 1; 590 } 591 592 /* We are done with atomic stuff, now do the rest of housekeeping */ 593 594 /* had we spliced it onto indirect block? */ 595 if (where->bh) 596 mark_buffer_dirty_inode(where->bh, inode); 597 598 inode->i_ctime = current_time(inode); 599 mark_inode_dirty(inode); 600 } 601 602 /* 603 * Allocation strategy is simple: if we have to allocate something, we will 604 * have to go the whole way to leaf. So let's do it before attaching anything 605 * to tree, set linkage between the newborn blocks, write them if sync is 606 * required, recheck the path, free and repeat if check fails, otherwise 607 * set the last missing link (that will protect us from any truncate-generated 608 * removals - all blocks on the path are immune now) and possibly force the 609 * write on the parent block. 610 * That has a nice additional property: no special recovery from the failed 611 * allocations is needed - we simply release blocks and do not touch anything 612 * reachable from inode. 613 * 614 * `handle' can be NULL if create == 0. 615 * 616 * return > 0, # of blocks mapped or allocated. 617 * return = 0, if plain lookup failed. 618 * return < 0, error case. 619 */ 620 static int ext2_get_blocks(struct inode *inode, 621 sector_t iblock, unsigned long maxblocks, 622 u32 *bno, bool *new, bool *boundary, 623 int create) 624 { 625 int err; 626 int offsets[4]; 627 Indirect chain[4]; 628 Indirect *partial; 629 ext2_fsblk_t goal; 630 int indirect_blks; 631 int blocks_to_boundary = 0; 632 int depth; 633 struct ext2_inode_info *ei = EXT2_I(inode); 634 int count = 0; 635 ext2_fsblk_t first_block = 0; 636 637 BUG_ON(maxblocks == 0); 638 639 depth = ext2_block_to_path(inode,iblock,offsets,&blocks_to_boundary); 640 641 if (depth == 0) 642 return -EIO; 643 644 partial = ext2_get_branch(inode, depth, offsets, chain, &err); 645 /* Simplest case - block found, no allocation needed */ 646 if (!partial) { 647 first_block = le32_to_cpu(chain[depth - 1].key); 648 count++; 649 /*map more blocks*/ 650 while (count < maxblocks && count <= blocks_to_boundary) { 651 ext2_fsblk_t blk; 652 653 if (!verify_chain(chain, chain + depth - 1)) { 654 /* 655 * Indirect block might be removed by 656 * truncate while we were reading it. 657 * Handling of that case: forget what we've 658 * got now, go to reread. 659 */ 660 err = -EAGAIN; 661 count = 0; 662 break; 663 } 664 blk = le32_to_cpu(*(chain[depth-1].p + count)); 665 if (blk == first_block + count) 666 count++; 667 else 668 break; 669 } 670 if (err != -EAGAIN) 671 goto got_it; 672 } 673 674 /* Next simple case - plain lookup or failed read of indirect block */ 675 if (!create || err == -EIO) 676 goto cleanup; 677 678 mutex_lock(&ei->truncate_mutex); 679 /* 680 * If the indirect block is missing while we are reading 681 * the chain(ext2_get_branch() returns -EAGAIN err), or 682 * if the chain has been changed after we grab the semaphore, 683 * (either because another process truncated this branch, or 684 * another get_block allocated this branch) re-grab the chain to see if 685 * the request block has been allocated or not. 686 * 687 * Since we already block the truncate/other get_block 688 * at this point, we will have the current copy of the chain when we 689 * splice the branch into the tree. 690 */ 691 if (err == -EAGAIN || !verify_chain(chain, partial)) { 692 while (partial > chain) { 693 brelse(partial->bh); 694 partial--; 695 } 696 partial = ext2_get_branch(inode, depth, offsets, chain, &err); 697 if (!partial) { 698 count++; 699 mutex_unlock(&ei->truncate_mutex); 700 if (err) 701 goto cleanup; 702 goto got_it; 703 } 704 } 705 706 /* 707 * Okay, we need to do block allocation. Lazily initialize the block 708 * allocation info here if necessary 709 */ 710 if (S_ISREG(inode->i_mode) && (!ei->i_block_alloc_info)) 711 ext2_init_block_alloc_info(inode); 712 713 goal = ext2_find_goal(inode, iblock, partial); 714 715 /* the number of blocks need to allocate for [d,t]indirect blocks */ 716 indirect_blks = (chain + depth) - partial - 1; 717 /* 718 * Next look up the indirect map to count the totoal number of 719 * direct blocks to allocate for this branch. 720 */ 721 count = ext2_blks_to_allocate(partial, indirect_blks, 722 maxblocks, blocks_to_boundary); 723 /* 724 * XXX ???? Block out ext2_truncate while we alter the tree 725 */ 726 err = ext2_alloc_branch(inode, indirect_blks, &count, goal, 727 offsets + (partial - chain), partial); 728 729 if (err) { 730 mutex_unlock(&ei->truncate_mutex); 731 goto cleanup; 732 } 733 734 if (IS_DAX(inode)) { 735 int i; 736 737 /* 738 * We must unmap blocks before zeroing so that writeback cannot 739 * overwrite zeros with stale data from block device page cache. 740 */ 741 for (i = 0; i < count; i++) { 742 unmap_underlying_metadata(inode->i_sb->s_bdev, 743 le32_to_cpu(chain[depth-1].key) + i); 744 } 745 /* 746 * block must be initialised before we put it in the tree 747 * so that it's not found by another thread before it's 748 * initialised 749 */ 750 err = sb_issue_zeroout(inode->i_sb, 751 le32_to_cpu(chain[depth-1].key), count, 752 GFP_NOFS); 753 if (err) { 754 mutex_unlock(&ei->truncate_mutex); 755 goto cleanup; 756 } 757 } else { 758 *new = true; 759 } 760 761 ext2_splice_branch(inode, iblock, partial, indirect_blks, count); 762 mutex_unlock(&ei->truncate_mutex); 763 got_it: 764 if (count > blocks_to_boundary) 765 *boundary = true; 766 err = count; 767 /* Clean up and exit */ 768 partial = chain + depth - 1; /* the whole chain */ 769 cleanup: 770 while (partial > chain) { 771 brelse(partial->bh); 772 partial--; 773 } 774 if (err > 0) 775 *bno = le32_to_cpu(chain[depth-1].key); 776 return err; 777 } 778 779 int ext2_get_block(struct inode *inode, sector_t iblock, 780 struct buffer_head *bh_result, int create) 781 { 782 unsigned max_blocks = bh_result->b_size >> inode->i_blkbits; 783 bool new = false, boundary = false; 784 u32 bno; 785 int ret; 786 787 ret = ext2_get_blocks(inode, iblock, max_blocks, &bno, &new, &boundary, 788 create); 789 if (ret <= 0) 790 return ret; 791 792 map_bh(bh_result, inode->i_sb, bno); 793 bh_result->b_size = (ret << inode->i_blkbits); 794 if (new) 795 set_buffer_new(bh_result); 796 if (boundary) 797 set_buffer_boundary(bh_result); 798 return 0; 799 800 } 801 802 #ifdef CONFIG_FS_DAX 803 static int ext2_iomap_begin(struct inode *inode, loff_t offset, loff_t length, 804 unsigned flags, struct iomap *iomap) 805 { 806 unsigned int blkbits = inode->i_blkbits; 807 unsigned long first_block = offset >> blkbits; 808 unsigned long max_blocks = (length + (1 << blkbits) - 1) >> blkbits; 809 bool new = false, boundary = false; 810 u32 bno; 811 int ret; 812 813 ret = ext2_get_blocks(inode, first_block, max_blocks, 814 &bno, &new, &boundary, flags & IOMAP_WRITE); 815 if (ret < 0) 816 return ret; 817 818 iomap->flags = 0; 819 iomap->bdev = inode->i_sb->s_bdev; 820 iomap->offset = (u64)first_block << blkbits; 821 822 if (ret == 0) { 823 iomap->type = IOMAP_HOLE; 824 iomap->blkno = IOMAP_NULL_BLOCK; 825 iomap->length = 1 << blkbits; 826 } else { 827 iomap->type = IOMAP_MAPPED; 828 iomap->blkno = (sector_t)bno << (blkbits - 9); 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 struct iomap_ops ext2_iomap_ops = { 850 .iomap_begin = ext2_iomap_begin, 851 .iomap_end = ext2_iomap_end, 852 }; 853 #endif /* CONFIG_FS_DAX */ 854 855 int ext2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, 856 u64 start, u64 len) 857 { 858 return generic_block_fiemap(inode, fieinfo, start, len, 859 ext2_get_block); 860 } 861 862 static int ext2_writepage(struct page *page, struct writeback_control *wbc) 863 { 864 return block_write_full_page(page, ext2_get_block, wbc); 865 } 866 867 static int ext2_readpage(struct file *file, struct page *page) 868 { 869 return mpage_readpage(page, ext2_get_block); 870 } 871 872 static int 873 ext2_readpages(struct file *file, struct address_space *mapping, 874 struct list_head *pages, unsigned nr_pages) 875 { 876 return mpage_readpages(mapping, pages, nr_pages, ext2_get_block); 877 } 878 879 static int 880 ext2_write_begin(struct file *file, struct address_space *mapping, 881 loff_t pos, unsigned len, unsigned flags, 882 struct page **pagep, void **fsdata) 883 { 884 int ret; 885 886 ret = block_write_begin(mapping, pos, len, flags, pagep, 887 ext2_get_block); 888 if (ret < 0) 889 ext2_write_failed(mapping, pos + len); 890 return ret; 891 } 892 893 static int ext2_write_end(struct file *file, struct address_space *mapping, 894 loff_t pos, unsigned len, unsigned copied, 895 struct page *page, void *fsdata) 896 { 897 int ret; 898 899 ret = generic_write_end(file, mapping, pos, len, copied, page, fsdata); 900 if (ret < len) 901 ext2_write_failed(mapping, pos + len); 902 return ret; 903 } 904 905 static int 906 ext2_nobh_write_begin(struct file *file, struct address_space *mapping, 907 loff_t pos, unsigned len, unsigned flags, 908 struct page **pagep, void **fsdata) 909 { 910 int ret; 911 912 ret = nobh_write_begin(mapping, pos, len, flags, pagep, fsdata, 913 ext2_get_block); 914 if (ret < 0) 915 ext2_write_failed(mapping, pos + len); 916 return ret; 917 } 918 919 static int ext2_nobh_writepage(struct page *page, 920 struct writeback_control *wbc) 921 { 922 return nobh_writepage(page, ext2_get_block, wbc); 923 } 924 925 static sector_t ext2_bmap(struct address_space *mapping, sector_t block) 926 { 927 return generic_block_bmap(mapping,block,ext2_get_block); 928 } 929 930 static ssize_t 931 ext2_direct_IO(struct kiocb *iocb, struct iov_iter *iter) 932 { 933 struct file *file = iocb->ki_filp; 934 struct address_space *mapping = file->f_mapping; 935 struct inode *inode = mapping->host; 936 size_t count = iov_iter_count(iter); 937 loff_t offset = iocb->ki_pos; 938 ssize_t ret; 939 940 if (WARN_ON_ONCE(IS_DAX(inode))) 941 return -EIO; 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 #ifdef CONFIG_FS_DAX 953 if (dax_mapping(mapping)) { 954 return dax_writeback_mapping_range(mapping, 955 mapping->host->i_sb->s_bdev, 956 wbc); 957 } 958 #endif 959 960 return mpage_writepages(mapping, wbc, ext2_get_block); 961 } 962 963 const struct address_space_operations ext2_aops = { 964 .readpage = ext2_readpage, 965 .readpages = ext2_readpages, 966 .writepage = ext2_writepage, 967 .write_begin = ext2_write_begin, 968 .write_end = ext2_write_end, 969 .bmap = ext2_bmap, 970 .direct_IO = ext2_direct_IO, 971 .writepages = ext2_writepages, 972 .migratepage = buffer_migrate_page, 973 .is_partially_uptodate = block_is_partially_uptodate, 974 .error_remove_page = generic_error_remove_page, 975 }; 976 977 const struct address_space_operations ext2_nobh_aops = { 978 .readpage = ext2_readpage, 979 .readpages = ext2_readpages, 980 .writepage = ext2_nobh_writepage, 981 .write_begin = ext2_nobh_write_begin, 982 .write_end = nobh_write_end, 983 .bmap = ext2_bmap, 984 .direct_IO = ext2_direct_IO, 985 .writepages = ext2_writepages, 986 .migratepage = buffer_migrate_page, 987 .error_remove_page = generic_error_remove_page, 988 }; 989 990 /* 991 * Probably it should be a library function... search for first non-zero word 992 * or memcmp with zero_page, whatever is better for particular architecture. 993 * Linus? 994 */ 995 static inline int all_zeroes(__le32 *p, __le32 *q) 996 { 997 while (p < q) 998 if (*p++) 999 return 0; 1000 return 1; 1001 } 1002 1003 /** 1004 * ext2_find_shared - find the indirect blocks for partial truncation. 1005 * @inode: inode in question 1006 * @depth: depth of the affected branch 1007 * @offsets: offsets of pointers in that branch (see ext2_block_to_path) 1008 * @chain: place to store the pointers to partial indirect blocks 1009 * @top: place to the (detached) top of branch 1010 * 1011 * This is a helper function used by ext2_truncate(). 1012 * 1013 * When we do truncate() we may have to clean the ends of several indirect 1014 * blocks but leave the blocks themselves alive. Block is partially 1015 * truncated if some data below the new i_size is referred from it (and 1016 * it is on the path to the first completely truncated data block, indeed). 1017 * We have to free the top of that path along with everything to the right 1018 * of the path. Since no allocation past the truncation point is possible 1019 * until ext2_truncate() finishes, we may safely do the latter, but top 1020 * of branch may require special attention - pageout below the truncation 1021 * point might try to populate it. 1022 * 1023 * We atomically detach the top of branch from the tree, store the block 1024 * number of its root in *@top, pointers to buffer_heads of partially 1025 * truncated blocks - in @chain[].bh and pointers to their last elements 1026 * that should not be removed - in @chain[].p. Return value is the pointer 1027 * to last filled element of @chain. 1028 * 1029 * The work left to caller to do the actual freeing of subtrees: 1030 * a) free the subtree starting from *@top 1031 * b) free the subtrees whose roots are stored in 1032 * (@chain[i].p+1 .. end of @chain[i].bh->b_data) 1033 * c) free the subtrees growing from the inode past the @chain[0].p 1034 * (no partially truncated stuff there). 1035 */ 1036 1037 static Indirect *ext2_find_shared(struct inode *inode, 1038 int depth, 1039 int offsets[4], 1040 Indirect chain[4], 1041 __le32 *top) 1042 { 1043 Indirect *partial, *p; 1044 int k, err; 1045 1046 *top = 0; 1047 for (k = depth; k > 1 && !offsets[k-1]; k--) 1048 ; 1049 partial = ext2_get_branch(inode, k, offsets, chain, &err); 1050 if (!partial) 1051 partial = chain + k-1; 1052 /* 1053 * If the branch acquired continuation since we've looked at it - 1054 * fine, it should all survive and (new) top doesn't belong to us. 1055 */ 1056 write_lock(&EXT2_I(inode)->i_meta_lock); 1057 if (!partial->key && *partial->p) { 1058 write_unlock(&EXT2_I(inode)->i_meta_lock); 1059 goto no_top; 1060 } 1061 for (p=partial; p>chain && all_zeroes((__le32*)p->bh->b_data,p->p); p--) 1062 ; 1063 /* 1064 * OK, we've found the last block that must survive. The rest of our 1065 * branch should be detached before unlocking. However, if that rest 1066 * of branch is all ours and does not grow immediately from the inode 1067 * it's easier to cheat and just decrement partial->p. 1068 */ 1069 if (p == chain + k - 1 && p > chain) { 1070 p->p--; 1071 } else { 1072 *top = *p->p; 1073 *p->p = 0; 1074 } 1075 write_unlock(&EXT2_I(inode)->i_meta_lock); 1076 1077 while(partial > p) 1078 { 1079 brelse(partial->bh); 1080 partial--; 1081 } 1082 no_top: 1083 return partial; 1084 } 1085 1086 /** 1087 * ext2_free_data - free a list of data blocks 1088 * @inode: inode we are dealing with 1089 * @p: array of block numbers 1090 * @q: points immediately past the end of array 1091 * 1092 * We are freeing all blocks referred from that array (numbers are 1093 * stored as little-endian 32-bit) and updating @inode->i_blocks 1094 * appropriately. 1095 */ 1096 static inline void ext2_free_data(struct inode *inode, __le32 *p, __le32 *q) 1097 { 1098 unsigned long block_to_free = 0, count = 0; 1099 unsigned long nr; 1100 1101 for ( ; p < q ; p++) { 1102 nr = le32_to_cpu(*p); 1103 if (nr) { 1104 *p = 0; 1105 /* accumulate blocks to free if they're contiguous */ 1106 if (count == 0) 1107 goto free_this; 1108 else if (block_to_free == nr - count) 1109 count++; 1110 else { 1111 ext2_free_blocks (inode, block_to_free, count); 1112 mark_inode_dirty(inode); 1113 free_this: 1114 block_to_free = nr; 1115 count = 1; 1116 } 1117 } 1118 } 1119 if (count > 0) { 1120 ext2_free_blocks (inode, block_to_free, count); 1121 mark_inode_dirty(inode); 1122 } 1123 } 1124 1125 /** 1126 * ext2_free_branches - free an array of branches 1127 * @inode: inode we are dealing with 1128 * @p: array of block numbers 1129 * @q: pointer immediately past the end of array 1130 * @depth: depth of the branches to free 1131 * 1132 * We are freeing all blocks referred from these branches (numbers are 1133 * stored as little-endian 32-bit) and updating @inode->i_blocks 1134 * appropriately. 1135 */ 1136 static void ext2_free_branches(struct inode *inode, __le32 *p, __le32 *q, int depth) 1137 { 1138 struct buffer_head * bh; 1139 unsigned long nr; 1140 1141 if (depth--) { 1142 int addr_per_block = EXT2_ADDR_PER_BLOCK(inode->i_sb); 1143 for ( ; p < q ; p++) { 1144 nr = le32_to_cpu(*p); 1145 if (!nr) 1146 continue; 1147 *p = 0; 1148 bh = sb_bread(inode->i_sb, nr); 1149 /* 1150 * A read failure? Report error and clear slot 1151 * (should be rare). 1152 */ 1153 if (!bh) { 1154 ext2_error(inode->i_sb, "ext2_free_branches", 1155 "Read failure, inode=%ld, block=%ld", 1156 inode->i_ino, nr); 1157 continue; 1158 } 1159 ext2_free_branches(inode, 1160 (__le32*)bh->b_data, 1161 (__le32*)bh->b_data + addr_per_block, 1162 depth); 1163 bforget(bh); 1164 ext2_free_blocks(inode, nr, 1); 1165 mark_inode_dirty(inode); 1166 } 1167 } else 1168 ext2_free_data(inode, p, q); 1169 } 1170 1171 /* dax_sem must be held when calling this function */ 1172 static void __ext2_truncate_blocks(struct inode *inode, loff_t offset) 1173 { 1174 __le32 *i_data = EXT2_I(inode)->i_data; 1175 struct ext2_inode_info *ei = EXT2_I(inode); 1176 int addr_per_block = EXT2_ADDR_PER_BLOCK(inode->i_sb); 1177 int offsets[4]; 1178 Indirect chain[4]; 1179 Indirect *partial; 1180 __le32 nr = 0; 1181 int n; 1182 long iblock; 1183 unsigned blocksize; 1184 blocksize = inode->i_sb->s_blocksize; 1185 iblock = (offset + blocksize-1) >> EXT2_BLOCK_SIZE_BITS(inode->i_sb); 1186 1187 #ifdef CONFIG_FS_DAX 1188 WARN_ON(!rwsem_is_locked(&ei->dax_sem)); 1189 #endif 1190 1191 n = ext2_block_to_path(inode, iblock, offsets, NULL); 1192 if (n == 0) 1193 return; 1194 1195 /* 1196 * From here we block out all ext2_get_block() callers who want to 1197 * modify the block allocation tree. 1198 */ 1199 mutex_lock(&ei->truncate_mutex); 1200 1201 if (n == 1) { 1202 ext2_free_data(inode, i_data+offsets[0], 1203 i_data + EXT2_NDIR_BLOCKS); 1204 goto do_indirects; 1205 } 1206 1207 partial = ext2_find_shared(inode, n, offsets, chain, &nr); 1208 /* Kill the top of shared branch (already detached) */ 1209 if (nr) { 1210 if (partial == chain) 1211 mark_inode_dirty(inode); 1212 else 1213 mark_buffer_dirty_inode(partial->bh, inode); 1214 ext2_free_branches(inode, &nr, &nr+1, (chain+n-1) - partial); 1215 } 1216 /* Clear the ends of indirect blocks on the shared branch */ 1217 while (partial > chain) { 1218 ext2_free_branches(inode, 1219 partial->p + 1, 1220 (__le32*)partial->bh->b_data+addr_per_block, 1221 (chain+n-1) - partial); 1222 mark_buffer_dirty_inode(partial->bh, inode); 1223 brelse (partial->bh); 1224 partial--; 1225 } 1226 do_indirects: 1227 /* Kill the remaining (whole) subtrees */ 1228 switch (offsets[0]) { 1229 default: 1230 nr = i_data[EXT2_IND_BLOCK]; 1231 if (nr) { 1232 i_data[EXT2_IND_BLOCK] = 0; 1233 mark_inode_dirty(inode); 1234 ext2_free_branches(inode, &nr, &nr+1, 1); 1235 } 1236 case EXT2_IND_BLOCK: 1237 nr = i_data[EXT2_DIND_BLOCK]; 1238 if (nr) { 1239 i_data[EXT2_DIND_BLOCK] = 0; 1240 mark_inode_dirty(inode); 1241 ext2_free_branches(inode, &nr, &nr+1, 2); 1242 } 1243 case EXT2_DIND_BLOCK: 1244 nr = i_data[EXT2_TIND_BLOCK]; 1245 if (nr) { 1246 i_data[EXT2_TIND_BLOCK] = 0; 1247 mark_inode_dirty(inode); 1248 ext2_free_branches(inode, &nr, &nr+1, 3); 1249 } 1250 case EXT2_TIND_BLOCK: 1251 ; 1252 } 1253 1254 ext2_discard_reservation(inode); 1255 1256 mutex_unlock(&ei->truncate_mutex); 1257 } 1258 1259 static void ext2_truncate_blocks(struct inode *inode, loff_t offset) 1260 { 1261 /* 1262 * XXX: it seems like a bug here that we don't allow 1263 * IS_APPEND inode to have blocks-past-i_size trimmed off. 1264 * review and fix this. 1265 * 1266 * Also would be nice to be able to handle IO errors and such, 1267 * but that's probably too much to ask. 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 if (IS_APPEND(inode) || IS_IMMUTABLE(inode)) 1275 return; 1276 1277 dax_sem_down_write(EXT2_I(inode)); 1278 __ext2_truncate_blocks(inode, offset); 1279 dax_sem_up_write(EXT2_I(inode)); 1280 } 1281 1282 static int ext2_setsize(struct inode *inode, loff_t newsize) 1283 { 1284 int error; 1285 1286 if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || 1287 S_ISLNK(inode->i_mode))) 1288 return -EINVAL; 1289 if (ext2_inode_is_fast_symlink(inode)) 1290 return -EINVAL; 1291 if (IS_APPEND(inode) || IS_IMMUTABLE(inode)) 1292 return -EPERM; 1293 1294 inode_dio_wait(inode); 1295 1296 if (IS_DAX(inode)) 1297 error = dax_truncate_page(inode, newsize, ext2_get_block); 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 /* Propagate flags from i_flags to EXT2_I(inode)->i_flags */ 1387 void ext2_get_inode_flags(struct ext2_inode_info *ei) 1388 { 1389 unsigned int flags = ei->vfs_inode.i_flags; 1390 1391 ei->i_flags &= ~(EXT2_SYNC_FL|EXT2_APPEND_FL| 1392 EXT2_IMMUTABLE_FL|EXT2_NOATIME_FL|EXT2_DIRSYNC_FL); 1393 if (flags & S_SYNC) 1394 ei->i_flags |= EXT2_SYNC_FL; 1395 if (flags & S_APPEND) 1396 ei->i_flags |= EXT2_APPEND_FL; 1397 if (flags & S_IMMUTABLE) 1398 ei->i_flags |= EXT2_IMMUTABLE_FL; 1399 if (flags & S_NOATIME) 1400 ei->i_flags |= EXT2_NOATIME_FL; 1401 if (flags & S_DIRSYNC) 1402 ei->i_flags |= EXT2_DIRSYNC_FL; 1403 } 1404 1405 struct inode *ext2_iget (struct super_block *sb, unsigned long ino) 1406 { 1407 struct ext2_inode_info *ei; 1408 struct buffer_head * bh; 1409 struct ext2_inode *raw_inode; 1410 struct inode *inode; 1411 long ret = -EIO; 1412 int n; 1413 uid_t i_uid; 1414 gid_t i_gid; 1415 1416 inode = iget_locked(sb, ino); 1417 if (!inode) 1418 return ERR_PTR(-ENOMEM); 1419 if (!(inode->i_state & I_NEW)) 1420 return inode; 1421 1422 ei = EXT2_I(inode); 1423 ei->i_block_alloc_info = NULL; 1424 1425 raw_inode = ext2_get_inode(inode->i_sb, ino, &bh); 1426 if (IS_ERR(raw_inode)) { 1427 ret = PTR_ERR(raw_inode); 1428 goto bad_inode; 1429 } 1430 1431 inode->i_mode = le16_to_cpu(raw_inode->i_mode); 1432 i_uid = (uid_t)le16_to_cpu(raw_inode->i_uid_low); 1433 i_gid = (gid_t)le16_to_cpu(raw_inode->i_gid_low); 1434 if (!(test_opt (inode->i_sb, NO_UID32))) { 1435 i_uid |= le16_to_cpu(raw_inode->i_uid_high) << 16; 1436 i_gid |= le16_to_cpu(raw_inode->i_gid_high) << 16; 1437 } 1438 i_uid_write(inode, i_uid); 1439 i_gid_write(inode, i_gid); 1440 set_nlink(inode, le16_to_cpu(raw_inode->i_links_count)); 1441 inode->i_size = le32_to_cpu(raw_inode->i_size); 1442 inode->i_atime.tv_sec = (signed)le32_to_cpu(raw_inode->i_atime); 1443 inode->i_ctime.tv_sec = (signed)le32_to_cpu(raw_inode->i_ctime); 1444 inode->i_mtime.tv_sec = (signed)le32_to_cpu(raw_inode->i_mtime); 1445 inode->i_atime.tv_nsec = inode->i_mtime.tv_nsec = inode->i_ctime.tv_nsec = 0; 1446 ei->i_dtime = le32_to_cpu(raw_inode->i_dtime); 1447 /* We now have enough fields to check if the inode was active or not. 1448 * This is needed because nfsd might try to access dead inodes 1449 * the test is that same one that e2fsck uses 1450 * NeilBrown 1999oct15 1451 */ 1452 if (inode->i_nlink == 0 && (inode->i_mode == 0 || ei->i_dtime)) { 1453 /* this inode is deleted */ 1454 brelse (bh); 1455 ret = -ESTALE; 1456 goto bad_inode; 1457 } 1458 inode->i_blocks = le32_to_cpu(raw_inode->i_blocks); 1459 ei->i_flags = le32_to_cpu(raw_inode->i_flags); 1460 ei->i_faddr = le32_to_cpu(raw_inode->i_faddr); 1461 ei->i_frag_no = raw_inode->i_frag; 1462 ei->i_frag_size = raw_inode->i_fsize; 1463 ei->i_file_acl = le32_to_cpu(raw_inode->i_file_acl); 1464 ei->i_dir_acl = 0; 1465 1466 if (ei->i_file_acl && 1467 !ext2_data_block_valid(EXT2_SB(sb), ei->i_file_acl, 1)) { 1468 ext2_error(sb, "ext2_iget", "bad extended attribute block %u", 1469 ei->i_file_acl); 1470 brelse(bh); 1471 ret = -EFSCORRUPTED; 1472 goto bad_inode; 1473 } 1474 1475 if (S_ISREG(inode->i_mode)) 1476 inode->i_size |= ((__u64)le32_to_cpu(raw_inode->i_size_high)) << 32; 1477 else 1478 ei->i_dir_acl = le32_to_cpu(raw_inode->i_dir_acl); 1479 ei->i_dtime = 0; 1480 inode->i_generation = le32_to_cpu(raw_inode->i_generation); 1481 ei->i_state = 0; 1482 ei->i_block_group = (ino - 1) / EXT2_INODES_PER_GROUP(inode->i_sb); 1483 ei->i_dir_start_lookup = 0; 1484 1485 /* 1486 * NOTE! The in-memory inode i_data array is in little-endian order 1487 * even on big-endian machines: we do NOT byteswap the block numbers! 1488 */ 1489 for (n = 0; n < EXT2_N_BLOCKS; n++) 1490 ei->i_data[n] = raw_inode->i_block[n]; 1491 1492 if (S_ISREG(inode->i_mode)) { 1493 inode->i_op = &ext2_file_inode_operations; 1494 if (test_opt(inode->i_sb, NOBH)) { 1495 inode->i_mapping->a_ops = &ext2_nobh_aops; 1496 inode->i_fop = &ext2_file_operations; 1497 } else { 1498 inode->i_mapping->a_ops = &ext2_aops; 1499 inode->i_fop = &ext2_file_operations; 1500 } 1501 } else if (S_ISDIR(inode->i_mode)) { 1502 inode->i_op = &ext2_dir_inode_operations; 1503 inode->i_fop = &ext2_dir_operations; 1504 if (test_opt(inode->i_sb, NOBH)) 1505 inode->i_mapping->a_ops = &ext2_nobh_aops; 1506 else 1507 inode->i_mapping->a_ops = &ext2_aops; 1508 } else if (S_ISLNK(inode->i_mode)) { 1509 if (ext2_inode_is_fast_symlink(inode)) { 1510 inode->i_link = (char *)ei->i_data; 1511 inode->i_op = &ext2_fast_symlink_inode_operations; 1512 nd_terminate_link(ei->i_data, inode->i_size, 1513 sizeof(ei->i_data) - 1); 1514 } else { 1515 inode->i_op = &ext2_symlink_inode_operations; 1516 inode_nohighmem(inode); 1517 if (test_opt(inode->i_sb, NOBH)) 1518 inode->i_mapping->a_ops = &ext2_nobh_aops; 1519 else 1520 inode->i_mapping->a_ops = &ext2_aops; 1521 } 1522 } else { 1523 inode->i_op = &ext2_special_inode_operations; 1524 if (raw_inode->i_block[0]) 1525 init_special_inode(inode, inode->i_mode, 1526 old_decode_dev(le32_to_cpu(raw_inode->i_block[0]))); 1527 else 1528 init_special_inode(inode, inode->i_mode, 1529 new_decode_dev(le32_to_cpu(raw_inode->i_block[1]))); 1530 } 1531 brelse (bh); 1532 ext2_set_inode_flags(inode); 1533 unlock_new_inode(inode); 1534 return inode; 1535 1536 bad_inode: 1537 iget_failed(inode); 1538 return ERR_PTR(ret); 1539 } 1540 1541 static int __ext2_write_inode(struct inode *inode, int do_sync) 1542 { 1543 struct ext2_inode_info *ei = EXT2_I(inode); 1544 struct super_block *sb = inode->i_sb; 1545 ino_t ino = inode->i_ino; 1546 uid_t uid = i_uid_read(inode); 1547 gid_t gid = i_gid_read(inode); 1548 struct buffer_head * bh; 1549 struct ext2_inode * raw_inode = ext2_get_inode(sb, ino, &bh); 1550 int n; 1551 int err = 0; 1552 1553 if (IS_ERR(raw_inode)) 1554 return -EIO; 1555 1556 /* For fields not not tracking in the in-memory inode, 1557 * initialise them to zero for new inodes. */ 1558 if (ei->i_state & EXT2_STATE_NEW) 1559 memset(raw_inode, 0, EXT2_SB(sb)->s_inode_size); 1560 1561 ext2_get_inode_flags(ei); 1562 raw_inode->i_mode = cpu_to_le16(inode->i_mode); 1563 if (!(test_opt(sb, NO_UID32))) { 1564 raw_inode->i_uid_low = cpu_to_le16(low_16_bits(uid)); 1565 raw_inode->i_gid_low = cpu_to_le16(low_16_bits(gid)); 1566 /* 1567 * Fix up interoperability with old kernels. Otherwise, old inodes get 1568 * re-used with the upper 16 bits of the uid/gid intact 1569 */ 1570 if (!ei->i_dtime) { 1571 raw_inode->i_uid_high = cpu_to_le16(high_16_bits(uid)); 1572 raw_inode->i_gid_high = cpu_to_le16(high_16_bits(gid)); 1573 } else { 1574 raw_inode->i_uid_high = 0; 1575 raw_inode->i_gid_high = 0; 1576 } 1577 } else { 1578 raw_inode->i_uid_low = cpu_to_le16(fs_high2lowuid(uid)); 1579 raw_inode->i_gid_low = cpu_to_le16(fs_high2lowgid(gid)); 1580 raw_inode->i_uid_high = 0; 1581 raw_inode->i_gid_high = 0; 1582 } 1583 raw_inode->i_links_count = cpu_to_le16(inode->i_nlink); 1584 raw_inode->i_size = cpu_to_le32(inode->i_size); 1585 raw_inode->i_atime = cpu_to_le32(inode->i_atime.tv_sec); 1586 raw_inode->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec); 1587 raw_inode->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec); 1588 1589 raw_inode->i_blocks = cpu_to_le32(inode->i_blocks); 1590 raw_inode->i_dtime = cpu_to_le32(ei->i_dtime); 1591 raw_inode->i_flags = cpu_to_le32(ei->i_flags); 1592 raw_inode->i_faddr = cpu_to_le32(ei->i_faddr); 1593 raw_inode->i_frag = ei->i_frag_no; 1594 raw_inode->i_fsize = ei->i_frag_size; 1595 raw_inode->i_file_acl = cpu_to_le32(ei->i_file_acl); 1596 if (!S_ISREG(inode->i_mode)) 1597 raw_inode->i_dir_acl = cpu_to_le32(ei->i_dir_acl); 1598 else { 1599 raw_inode->i_size_high = cpu_to_le32(inode->i_size >> 32); 1600 if (inode->i_size > 0x7fffffffULL) { 1601 if (!EXT2_HAS_RO_COMPAT_FEATURE(sb, 1602 EXT2_FEATURE_RO_COMPAT_LARGE_FILE) || 1603 EXT2_SB(sb)->s_es->s_rev_level == 1604 cpu_to_le32(EXT2_GOOD_OLD_REV)) { 1605 /* If this is the first large file 1606 * created, add a flag to the superblock. 1607 */ 1608 spin_lock(&EXT2_SB(sb)->s_lock); 1609 ext2_update_dynamic_rev(sb); 1610 EXT2_SET_RO_COMPAT_FEATURE(sb, 1611 EXT2_FEATURE_RO_COMPAT_LARGE_FILE); 1612 spin_unlock(&EXT2_SB(sb)->s_lock); 1613 ext2_write_super(sb); 1614 } 1615 } 1616 } 1617 1618 raw_inode->i_generation = cpu_to_le32(inode->i_generation); 1619 if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) { 1620 if (old_valid_dev(inode->i_rdev)) { 1621 raw_inode->i_block[0] = 1622 cpu_to_le32(old_encode_dev(inode->i_rdev)); 1623 raw_inode->i_block[1] = 0; 1624 } else { 1625 raw_inode->i_block[0] = 0; 1626 raw_inode->i_block[1] = 1627 cpu_to_le32(new_encode_dev(inode->i_rdev)); 1628 raw_inode->i_block[2] = 0; 1629 } 1630 } else for (n = 0; n < EXT2_N_BLOCKS; n++) 1631 raw_inode->i_block[n] = ei->i_data[n]; 1632 mark_buffer_dirty(bh); 1633 if (do_sync) { 1634 sync_dirty_buffer(bh); 1635 if (buffer_req(bh) && !buffer_uptodate(bh)) { 1636 printk ("IO error syncing ext2 inode [%s:%08lx]\n", 1637 sb->s_id, (unsigned long) ino); 1638 err = -EIO; 1639 } 1640 } 1641 ei->i_state &= ~EXT2_STATE_NEW; 1642 brelse (bh); 1643 return err; 1644 } 1645 1646 int ext2_write_inode(struct inode *inode, struct writeback_control *wbc) 1647 { 1648 return __ext2_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL); 1649 } 1650 1651 int ext2_setattr(struct dentry *dentry, struct iattr *iattr) 1652 { 1653 struct inode *inode = d_inode(dentry); 1654 int error; 1655 1656 error = setattr_prepare(dentry, iattr); 1657 if (error) 1658 return error; 1659 1660 if (is_quota_modification(inode, iattr)) { 1661 error = dquot_initialize(inode); 1662 if (error) 1663 return error; 1664 } 1665 if ((iattr->ia_valid & ATTR_UID && !uid_eq(iattr->ia_uid, inode->i_uid)) || 1666 (iattr->ia_valid & ATTR_GID && !gid_eq(iattr->ia_gid, inode->i_gid))) { 1667 error = dquot_transfer(inode, iattr); 1668 if (error) 1669 return error; 1670 } 1671 if (iattr->ia_valid & ATTR_SIZE && iattr->ia_size != inode->i_size) { 1672 error = ext2_setsize(inode, iattr->ia_size); 1673 if (error) 1674 return error; 1675 } 1676 setattr_copy(inode, iattr); 1677 if (iattr->ia_valid & ATTR_MODE) 1678 error = posix_acl_chmod(inode, inode->i_mode); 1679 mark_inode_dirty(inode); 1680 1681 return error; 1682 } 1683