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 /* 736 * We must unmap blocks before zeroing so that writeback cannot 737 * overwrite zeros with stale data from block device page cache. 738 */ 739 clean_bdev_aliases(inode->i_sb->s_bdev, 740 le32_to_cpu(chain[depth-1].key), 741 count); 742 /* 743 * block must be initialised before we put it in the tree 744 * so that it's not found by another thread before it's 745 * initialised 746 */ 747 err = sb_issue_zeroout(inode->i_sb, 748 le32_to_cpu(chain[depth-1].key), count, 749 GFP_NOFS); 750 if (err) { 751 mutex_unlock(&ei->truncate_mutex); 752 goto cleanup; 753 } 754 } 755 *new = true; 756 757 ext2_splice_branch(inode, iblock, partial, indirect_blks, count); 758 mutex_unlock(&ei->truncate_mutex); 759 got_it: 760 if (count > blocks_to_boundary) 761 *boundary = true; 762 err = count; 763 /* Clean up and exit */ 764 partial = chain + depth - 1; /* the whole chain */ 765 cleanup: 766 while (partial > chain) { 767 brelse(partial->bh); 768 partial--; 769 } 770 if (err > 0) 771 *bno = le32_to_cpu(chain[depth-1].key); 772 return err; 773 } 774 775 int ext2_get_block(struct inode *inode, sector_t iblock, 776 struct buffer_head *bh_result, int create) 777 { 778 unsigned max_blocks = bh_result->b_size >> inode->i_blkbits; 779 bool new = false, boundary = false; 780 u32 bno; 781 int ret; 782 783 ret = ext2_get_blocks(inode, iblock, max_blocks, &bno, &new, &boundary, 784 create); 785 if (ret <= 0) 786 return ret; 787 788 map_bh(bh_result, inode->i_sb, bno); 789 bh_result->b_size = (ret << inode->i_blkbits); 790 if (new) 791 set_buffer_new(bh_result); 792 if (boundary) 793 set_buffer_boundary(bh_result); 794 return 0; 795 796 } 797 798 #ifdef CONFIG_FS_DAX 799 static int ext2_iomap_begin(struct inode *inode, loff_t offset, loff_t length, 800 unsigned flags, struct iomap *iomap) 801 { 802 unsigned int blkbits = inode->i_blkbits; 803 unsigned long first_block = offset >> blkbits; 804 unsigned long max_blocks = (length + (1 << blkbits) - 1) >> blkbits; 805 bool new = false, boundary = false; 806 u32 bno; 807 int ret; 808 809 ret = ext2_get_blocks(inode, first_block, max_blocks, 810 &bno, &new, &boundary, flags & IOMAP_WRITE); 811 if (ret < 0) 812 return ret; 813 814 iomap->flags = 0; 815 iomap->bdev = inode->i_sb->s_bdev; 816 iomap->offset = (u64)first_block << blkbits; 817 818 if (ret == 0) { 819 iomap->type = IOMAP_HOLE; 820 iomap->blkno = IOMAP_NULL_BLOCK; 821 iomap->length = 1 << blkbits; 822 } else { 823 iomap->type = IOMAP_MAPPED; 824 iomap->blkno = (sector_t)bno << (blkbits - 9); 825 iomap->length = (u64)ret << blkbits; 826 iomap->flags |= IOMAP_F_MERGED; 827 } 828 829 if (new) 830 iomap->flags |= IOMAP_F_NEW; 831 return 0; 832 } 833 834 static int 835 ext2_iomap_end(struct inode *inode, loff_t offset, loff_t length, 836 ssize_t written, unsigned flags, struct iomap *iomap) 837 { 838 if (iomap->type == IOMAP_MAPPED && 839 written < length && 840 (flags & IOMAP_WRITE)) 841 ext2_write_failed(inode->i_mapping, offset + length); 842 return 0; 843 } 844 845 struct iomap_ops ext2_iomap_ops = { 846 .iomap_begin = ext2_iomap_begin, 847 .iomap_end = ext2_iomap_end, 848 }; 849 #else 850 /* Define empty ops for !CONFIG_FS_DAX case to avoid ugly ifdefs */ 851 struct iomap_ops ext2_iomap_ops; 852 #endif /* CONFIG_FS_DAX */ 853 854 int ext2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, 855 u64 start, u64 len) 856 { 857 return generic_block_fiemap(inode, fieinfo, start, len, 858 ext2_get_block); 859 } 860 861 static int ext2_writepage(struct page *page, struct writeback_control *wbc) 862 { 863 return block_write_full_page(page, ext2_get_block, wbc); 864 } 865 866 static int ext2_readpage(struct file *file, struct page *page) 867 { 868 return mpage_readpage(page, ext2_get_block); 869 } 870 871 static int 872 ext2_readpages(struct file *file, struct address_space *mapping, 873 struct list_head *pages, unsigned nr_pages) 874 { 875 return mpage_readpages(mapping, pages, nr_pages, ext2_get_block); 876 } 877 878 static int 879 ext2_write_begin(struct file *file, struct address_space *mapping, 880 loff_t pos, unsigned len, unsigned flags, 881 struct page **pagep, void **fsdata) 882 { 883 int ret; 884 885 ret = block_write_begin(mapping, pos, len, flags, pagep, 886 ext2_get_block); 887 if (ret < 0) 888 ext2_write_failed(mapping, pos + len); 889 return ret; 890 } 891 892 static int ext2_write_end(struct file *file, struct address_space *mapping, 893 loff_t pos, unsigned len, unsigned copied, 894 struct page *page, void *fsdata) 895 { 896 int ret; 897 898 ret = generic_write_end(file, mapping, pos, len, copied, page, fsdata); 899 if (ret < len) 900 ext2_write_failed(mapping, pos + len); 901 return ret; 902 } 903 904 static int 905 ext2_nobh_write_begin(struct file *file, struct address_space *mapping, 906 loff_t pos, unsigned len, unsigned flags, 907 struct page **pagep, void **fsdata) 908 { 909 int ret; 910 911 ret = nobh_write_begin(mapping, pos, len, flags, pagep, fsdata, 912 ext2_get_block); 913 if (ret < 0) 914 ext2_write_failed(mapping, pos + len); 915 return ret; 916 } 917 918 static int ext2_nobh_writepage(struct page *page, 919 struct writeback_control *wbc) 920 { 921 return nobh_writepage(page, ext2_get_block, wbc); 922 } 923 924 static sector_t ext2_bmap(struct address_space *mapping, sector_t block) 925 { 926 return generic_block_bmap(mapping,block,ext2_get_block); 927 } 928 929 static ssize_t 930 ext2_direct_IO(struct kiocb *iocb, struct iov_iter *iter) 931 { 932 struct file *file = iocb->ki_filp; 933 struct address_space *mapping = file->f_mapping; 934 struct inode *inode = mapping->host; 935 size_t count = iov_iter_count(iter); 936 loff_t offset = iocb->ki_pos; 937 ssize_t ret; 938 939 if (WARN_ON_ONCE(IS_DAX(inode))) 940 return -EIO; 941 942 ret = blockdev_direct_IO(iocb, inode, iter, ext2_get_block); 943 if (ret < 0 && iov_iter_rw(iter) == WRITE) 944 ext2_write_failed(mapping, offset + count); 945 return ret; 946 } 947 948 static int 949 ext2_writepages(struct address_space *mapping, struct writeback_control *wbc) 950 { 951 #ifdef CONFIG_FS_DAX 952 if (dax_mapping(mapping)) { 953 return dax_writeback_mapping_range(mapping, 954 mapping->host->i_sb->s_bdev, 955 wbc); 956 } 957 #endif 958 959 return mpage_writepages(mapping, wbc, ext2_get_block); 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 /* 990 * Probably it should be a library function... search for first non-zero word 991 * or memcmp with zero_page, whatever is better for particular architecture. 992 * Linus? 993 */ 994 static inline int all_zeroes(__le32 *p, __le32 *q) 995 { 996 while (p < q) 997 if (*p++) 998 return 0; 999 return 1; 1000 } 1001 1002 /** 1003 * ext2_find_shared - find the indirect blocks for partial truncation. 1004 * @inode: inode in question 1005 * @depth: depth of the affected branch 1006 * @offsets: offsets of pointers in that branch (see ext2_block_to_path) 1007 * @chain: place to store the pointers to partial indirect blocks 1008 * @top: place to the (detached) top of branch 1009 * 1010 * This is a helper function used by ext2_truncate(). 1011 * 1012 * When we do truncate() we may have to clean the ends of several indirect 1013 * blocks but leave the blocks themselves alive. Block is partially 1014 * truncated if some data below the new i_size is referred from it (and 1015 * it is on the path to the first completely truncated data block, indeed). 1016 * We have to free the top of that path along with everything to the right 1017 * of the path. Since no allocation past the truncation point is possible 1018 * until ext2_truncate() finishes, we may safely do the latter, but top 1019 * of branch may require special attention - pageout below the truncation 1020 * point might try to populate it. 1021 * 1022 * We atomically detach the top of branch from the tree, store the block 1023 * number of its root in *@top, pointers to buffer_heads of partially 1024 * truncated blocks - in @chain[].bh and pointers to their last elements 1025 * that should not be removed - in @chain[].p. Return value is the pointer 1026 * to last filled element of @chain. 1027 * 1028 * The work left to caller to do the actual freeing of subtrees: 1029 * a) free the subtree starting from *@top 1030 * b) free the subtrees whose roots are stored in 1031 * (@chain[i].p+1 .. end of @chain[i].bh->b_data) 1032 * c) free the subtrees growing from the inode past the @chain[0].p 1033 * (no partially truncated stuff there). 1034 */ 1035 1036 static Indirect *ext2_find_shared(struct inode *inode, 1037 int depth, 1038 int offsets[4], 1039 Indirect chain[4], 1040 __le32 *top) 1041 { 1042 Indirect *partial, *p; 1043 int k, err; 1044 1045 *top = 0; 1046 for (k = depth; k > 1 && !offsets[k-1]; k--) 1047 ; 1048 partial = ext2_get_branch(inode, k, offsets, chain, &err); 1049 if (!partial) 1050 partial = chain + k-1; 1051 /* 1052 * If the branch acquired continuation since we've looked at it - 1053 * fine, it should all survive and (new) top doesn't belong to us. 1054 */ 1055 write_lock(&EXT2_I(inode)->i_meta_lock); 1056 if (!partial->key && *partial->p) { 1057 write_unlock(&EXT2_I(inode)->i_meta_lock); 1058 goto no_top; 1059 } 1060 for (p=partial; p>chain && all_zeroes((__le32*)p->bh->b_data,p->p); p--) 1061 ; 1062 /* 1063 * OK, we've found the last block that must survive. The rest of our 1064 * branch should be detached before unlocking. However, if that rest 1065 * of branch is all ours and does not grow immediately from the inode 1066 * it's easier to cheat and just decrement partial->p. 1067 */ 1068 if (p == chain + k - 1 && p > chain) { 1069 p->p--; 1070 } else { 1071 *top = *p->p; 1072 *p->p = 0; 1073 } 1074 write_unlock(&EXT2_I(inode)->i_meta_lock); 1075 1076 while(partial > p) 1077 { 1078 brelse(partial->bh); 1079 partial--; 1080 } 1081 no_top: 1082 return partial; 1083 } 1084 1085 /** 1086 * ext2_free_data - free a list of data blocks 1087 * @inode: inode we are dealing with 1088 * @p: array of block numbers 1089 * @q: points immediately past the end of array 1090 * 1091 * We are freeing all blocks referred from that array (numbers are 1092 * stored as little-endian 32-bit) and updating @inode->i_blocks 1093 * appropriately. 1094 */ 1095 static inline void ext2_free_data(struct inode *inode, __le32 *p, __le32 *q) 1096 { 1097 unsigned long block_to_free = 0, count = 0; 1098 unsigned long nr; 1099 1100 for ( ; p < q ; p++) { 1101 nr = le32_to_cpu(*p); 1102 if (nr) { 1103 *p = 0; 1104 /* accumulate blocks to free if they're contiguous */ 1105 if (count == 0) 1106 goto free_this; 1107 else if (block_to_free == nr - count) 1108 count++; 1109 else { 1110 ext2_free_blocks (inode, block_to_free, count); 1111 mark_inode_dirty(inode); 1112 free_this: 1113 block_to_free = nr; 1114 count = 1; 1115 } 1116 } 1117 } 1118 if (count > 0) { 1119 ext2_free_blocks (inode, block_to_free, count); 1120 mark_inode_dirty(inode); 1121 } 1122 } 1123 1124 /** 1125 * ext2_free_branches - free an array of branches 1126 * @inode: inode we are dealing with 1127 * @p: array of block numbers 1128 * @q: pointer immediately past the end of array 1129 * @depth: depth of the branches to free 1130 * 1131 * We are freeing all blocks referred from these branches (numbers are 1132 * stored as little-endian 32-bit) and updating @inode->i_blocks 1133 * appropriately. 1134 */ 1135 static void ext2_free_branches(struct inode *inode, __le32 *p, __le32 *q, int depth) 1136 { 1137 struct buffer_head * bh; 1138 unsigned long nr; 1139 1140 if (depth--) { 1141 int addr_per_block = EXT2_ADDR_PER_BLOCK(inode->i_sb); 1142 for ( ; p < q ; p++) { 1143 nr = le32_to_cpu(*p); 1144 if (!nr) 1145 continue; 1146 *p = 0; 1147 bh = sb_bread(inode->i_sb, nr); 1148 /* 1149 * A read failure? Report error and clear slot 1150 * (should be rare). 1151 */ 1152 if (!bh) { 1153 ext2_error(inode->i_sb, "ext2_free_branches", 1154 "Read failure, inode=%ld, block=%ld", 1155 inode->i_ino, nr); 1156 continue; 1157 } 1158 ext2_free_branches(inode, 1159 (__le32*)bh->b_data, 1160 (__le32*)bh->b_data + addr_per_block, 1161 depth); 1162 bforget(bh); 1163 ext2_free_blocks(inode, nr, 1); 1164 mark_inode_dirty(inode); 1165 } 1166 } else 1167 ext2_free_data(inode, p, q); 1168 } 1169 1170 /* dax_sem must be held when calling this function */ 1171 static void __ext2_truncate_blocks(struct inode *inode, loff_t offset) 1172 { 1173 __le32 *i_data = EXT2_I(inode)->i_data; 1174 struct ext2_inode_info *ei = EXT2_I(inode); 1175 int addr_per_block = EXT2_ADDR_PER_BLOCK(inode->i_sb); 1176 int offsets[4]; 1177 Indirect chain[4]; 1178 Indirect *partial; 1179 __le32 nr = 0; 1180 int n; 1181 long iblock; 1182 unsigned blocksize; 1183 blocksize = inode->i_sb->s_blocksize; 1184 iblock = (offset + blocksize-1) >> EXT2_BLOCK_SIZE_BITS(inode->i_sb); 1185 1186 #ifdef CONFIG_FS_DAX 1187 WARN_ON(!rwsem_is_locked(&ei->dax_sem)); 1188 #endif 1189 1190 n = ext2_block_to_path(inode, iblock, offsets, NULL); 1191 if (n == 0) 1192 return; 1193 1194 /* 1195 * From here we block out all ext2_get_block() callers who want to 1196 * modify the block allocation tree. 1197 */ 1198 mutex_lock(&ei->truncate_mutex); 1199 1200 if (n == 1) { 1201 ext2_free_data(inode, i_data+offsets[0], 1202 i_data + EXT2_NDIR_BLOCKS); 1203 goto do_indirects; 1204 } 1205 1206 partial = ext2_find_shared(inode, n, offsets, chain, &nr); 1207 /* Kill the top of shared branch (already detached) */ 1208 if (nr) { 1209 if (partial == chain) 1210 mark_inode_dirty(inode); 1211 else 1212 mark_buffer_dirty_inode(partial->bh, inode); 1213 ext2_free_branches(inode, &nr, &nr+1, (chain+n-1) - partial); 1214 } 1215 /* Clear the ends of indirect blocks on the shared branch */ 1216 while (partial > chain) { 1217 ext2_free_branches(inode, 1218 partial->p + 1, 1219 (__le32*)partial->bh->b_data+addr_per_block, 1220 (chain+n-1) - partial); 1221 mark_buffer_dirty_inode(partial->bh, inode); 1222 brelse (partial->bh); 1223 partial--; 1224 } 1225 do_indirects: 1226 /* Kill the remaining (whole) subtrees */ 1227 switch (offsets[0]) { 1228 default: 1229 nr = i_data[EXT2_IND_BLOCK]; 1230 if (nr) { 1231 i_data[EXT2_IND_BLOCK] = 0; 1232 mark_inode_dirty(inode); 1233 ext2_free_branches(inode, &nr, &nr+1, 1); 1234 } 1235 case EXT2_IND_BLOCK: 1236 nr = i_data[EXT2_DIND_BLOCK]; 1237 if (nr) { 1238 i_data[EXT2_DIND_BLOCK] = 0; 1239 mark_inode_dirty(inode); 1240 ext2_free_branches(inode, &nr, &nr+1, 2); 1241 } 1242 case EXT2_DIND_BLOCK: 1243 nr = i_data[EXT2_TIND_BLOCK]; 1244 if (nr) { 1245 i_data[EXT2_TIND_BLOCK] = 0; 1246 mark_inode_dirty(inode); 1247 ext2_free_branches(inode, &nr, &nr+1, 3); 1248 } 1249 case EXT2_TIND_BLOCK: 1250 ; 1251 } 1252 1253 ext2_discard_reservation(inode); 1254 1255 mutex_unlock(&ei->truncate_mutex); 1256 } 1257 1258 static void ext2_truncate_blocks(struct inode *inode, loff_t offset) 1259 { 1260 /* 1261 * XXX: it seems like a bug here that we don't allow 1262 * IS_APPEND inode to have blocks-past-i_size trimmed off. 1263 * review and fix this. 1264 * 1265 * Also would be nice to be able to handle IO errors and such, 1266 * but that's probably too much to ask. 1267 */ 1268 if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || 1269 S_ISLNK(inode->i_mode))) 1270 return; 1271 if (ext2_inode_is_fast_symlink(inode)) 1272 return; 1273 if (IS_APPEND(inode) || IS_IMMUTABLE(inode)) 1274 return; 1275 1276 dax_sem_down_write(EXT2_I(inode)); 1277 __ext2_truncate_blocks(inode, offset); 1278 dax_sem_up_write(EXT2_I(inode)); 1279 } 1280 1281 static int ext2_setsize(struct inode *inode, loff_t newsize) 1282 { 1283 int error; 1284 1285 if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || 1286 S_ISLNK(inode->i_mode))) 1287 return -EINVAL; 1288 if (ext2_inode_is_fast_symlink(inode)) 1289 return -EINVAL; 1290 if (IS_APPEND(inode) || IS_IMMUTABLE(inode)) 1291 return -EPERM; 1292 1293 inode_dio_wait(inode); 1294 1295 if (IS_DAX(inode)) { 1296 error = iomap_zero_range(inode, newsize, 1297 PAGE_ALIGN(newsize) - newsize, NULL, 1298 &ext2_iomap_ops); 1299 } else if (test_opt(inode->i_sb, NOBH)) 1300 error = nobh_truncate_page(inode->i_mapping, 1301 newsize, ext2_get_block); 1302 else 1303 error = block_truncate_page(inode->i_mapping, 1304 newsize, ext2_get_block); 1305 if (error) 1306 return error; 1307 1308 dax_sem_down_write(EXT2_I(inode)); 1309 truncate_setsize(inode, newsize); 1310 __ext2_truncate_blocks(inode, newsize); 1311 dax_sem_up_write(EXT2_I(inode)); 1312 1313 inode->i_mtime = inode->i_ctime = current_time(inode); 1314 if (inode_needs_sync(inode)) { 1315 sync_mapping_buffers(inode->i_mapping); 1316 sync_inode_metadata(inode, 1); 1317 } else { 1318 mark_inode_dirty(inode); 1319 } 1320 1321 return 0; 1322 } 1323 1324 static struct ext2_inode *ext2_get_inode(struct super_block *sb, ino_t ino, 1325 struct buffer_head **p) 1326 { 1327 struct buffer_head * bh; 1328 unsigned long block_group; 1329 unsigned long block; 1330 unsigned long offset; 1331 struct ext2_group_desc * gdp; 1332 1333 *p = NULL; 1334 if ((ino != EXT2_ROOT_INO && ino < EXT2_FIRST_INO(sb)) || 1335 ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count)) 1336 goto Einval; 1337 1338 block_group = (ino - 1) / EXT2_INODES_PER_GROUP(sb); 1339 gdp = ext2_get_group_desc(sb, block_group, NULL); 1340 if (!gdp) 1341 goto Egdp; 1342 /* 1343 * Figure out the offset within the block group inode table 1344 */ 1345 offset = ((ino - 1) % EXT2_INODES_PER_GROUP(sb)) * EXT2_INODE_SIZE(sb); 1346 block = le32_to_cpu(gdp->bg_inode_table) + 1347 (offset >> EXT2_BLOCK_SIZE_BITS(sb)); 1348 if (!(bh = sb_bread(sb, block))) 1349 goto Eio; 1350 1351 *p = bh; 1352 offset &= (EXT2_BLOCK_SIZE(sb) - 1); 1353 return (struct ext2_inode *) (bh->b_data + offset); 1354 1355 Einval: 1356 ext2_error(sb, "ext2_get_inode", "bad inode number: %lu", 1357 (unsigned long) ino); 1358 return ERR_PTR(-EINVAL); 1359 Eio: 1360 ext2_error(sb, "ext2_get_inode", 1361 "unable to read inode block - inode=%lu, block=%lu", 1362 (unsigned long) ino, block); 1363 Egdp: 1364 return ERR_PTR(-EIO); 1365 } 1366 1367 void ext2_set_inode_flags(struct inode *inode) 1368 { 1369 unsigned int flags = EXT2_I(inode)->i_flags; 1370 1371 inode->i_flags &= ~(S_SYNC | S_APPEND | S_IMMUTABLE | S_NOATIME | 1372 S_DIRSYNC | S_DAX); 1373 if (flags & EXT2_SYNC_FL) 1374 inode->i_flags |= S_SYNC; 1375 if (flags & EXT2_APPEND_FL) 1376 inode->i_flags |= S_APPEND; 1377 if (flags & EXT2_IMMUTABLE_FL) 1378 inode->i_flags |= S_IMMUTABLE; 1379 if (flags & EXT2_NOATIME_FL) 1380 inode->i_flags |= S_NOATIME; 1381 if (flags & EXT2_DIRSYNC_FL) 1382 inode->i_flags |= S_DIRSYNC; 1383 if (test_opt(inode->i_sb, DAX) && S_ISREG(inode->i_mode)) 1384 inode->i_flags |= S_DAX; 1385 } 1386 1387 /* Propagate flags from i_flags to EXT2_I(inode)->i_flags */ 1388 void ext2_get_inode_flags(struct ext2_inode_info *ei) 1389 { 1390 unsigned int flags = ei->vfs_inode.i_flags; 1391 1392 ei->i_flags &= ~(EXT2_SYNC_FL|EXT2_APPEND_FL| 1393 EXT2_IMMUTABLE_FL|EXT2_NOATIME_FL|EXT2_DIRSYNC_FL); 1394 if (flags & S_SYNC) 1395 ei->i_flags |= EXT2_SYNC_FL; 1396 if (flags & S_APPEND) 1397 ei->i_flags |= EXT2_APPEND_FL; 1398 if (flags & S_IMMUTABLE) 1399 ei->i_flags |= EXT2_IMMUTABLE_FL; 1400 if (flags & S_NOATIME) 1401 ei->i_flags |= EXT2_NOATIME_FL; 1402 if (flags & S_DIRSYNC) 1403 ei->i_flags |= EXT2_DIRSYNC_FL; 1404 } 1405 1406 struct inode *ext2_iget (struct super_block *sb, unsigned long ino) 1407 { 1408 struct ext2_inode_info *ei; 1409 struct buffer_head * bh; 1410 struct ext2_inode *raw_inode; 1411 struct inode *inode; 1412 long ret = -EIO; 1413 int n; 1414 uid_t i_uid; 1415 gid_t i_gid; 1416 1417 inode = iget_locked(sb, ino); 1418 if (!inode) 1419 return ERR_PTR(-ENOMEM); 1420 if (!(inode->i_state & I_NEW)) 1421 return inode; 1422 1423 ei = EXT2_I(inode); 1424 ei->i_block_alloc_info = NULL; 1425 1426 raw_inode = ext2_get_inode(inode->i_sb, ino, &bh); 1427 if (IS_ERR(raw_inode)) { 1428 ret = PTR_ERR(raw_inode); 1429 goto bad_inode; 1430 } 1431 1432 inode->i_mode = le16_to_cpu(raw_inode->i_mode); 1433 i_uid = (uid_t)le16_to_cpu(raw_inode->i_uid_low); 1434 i_gid = (gid_t)le16_to_cpu(raw_inode->i_gid_low); 1435 if (!(test_opt (inode->i_sb, NO_UID32))) { 1436 i_uid |= le16_to_cpu(raw_inode->i_uid_high) << 16; 1437 i_gid |= le16_to_cpu(raw_inode->i_gid_high) << 16; 1438 } 1439 i_uid_write(inode, i_uid); 1440 i_gid_write(inode, i_gid); 1441 set_nlink(inode, le16_to_cpu(raw_inode->i_links_count)); 1442 inode->i_size = le32_to_cpu(raw_inode->i_size); 1443 inode->i_atime.tv_sec = (signed)le32_to_cpu(raw_inode->i_atime); 1444 inode->i_ctime.tv_sec = (signed)le32_to_cpu(raw_inode->i_ctime); 1445 inode->i_mtime.tv_sec = (signed)le32_to_cpu(raw_inode->i_mtime); 1446 inode->i_atime.tv_nsec = inode->i_mtime.tv_nsec = inode->i_ctime.tv_nsec = 0; 1447 ei->i_dtime = le32_to_cpu(raw_inode->i_dtime); 1448 /* We now have enough fields to check if the inode was active or not. 1449 * This is needed because nfsd might try to access dead inodes 1450 * the test is that same one that e2fsck uses 1451 * NeilBrown 1999oct15 1452 */ 1453 if (inode->i_nlink == 0 && (inode->i_mode == 0 || ei->i_dtime)) { 1454 /* this inode is deleted */ 1455 brelse (bh); 1456 ret = -ESTALE; 1457 goto bad_inode; 1458 } 1459 inode->i_blocks = le32_to_cpu(raw_inode->i_blocks); 1460 ei->i_flags = le32_to_cpu(raw_inode->i_flags); 1461 ei->i_faddr = le32_to_cpu(raw_inode->i_faddr); 1462 ei->i_frag_no = raw_inode->i_frag; 1463 ei->i_frag_size = raw_inode->i_fsize; 1464 ei->i_file_acl = le32_to_cpu(raw_inode->i_file_acl); 1465 ei->i_dir_acl = 0; 1466 1467 if (ei->i_file_acl && 1468 !ext2_data_block_valid(EXT2_SB(sb), ei->i_file_acl, 1)) { 1469 ext2_error(sb, "ext2_iget", "bad extended attribute block %u", 1470 ei->i_file_acl); 1471 brelse(bh); 1472 ret = -EFSCORRUPTED; 1473 goto bad_inode; 1474 } 1475 1476 if (S_ISREG(inode->i_mode)) 1477 inode->i_size |= ((__u64)le32_to_cpu(raw_inode->i_size_high)) << 32; 1478 else 1479 ei->i_dir_acl = le32_to_cpu(raw_inode->i_dir_acl); 1480 if (i_size_read(inode) < 0) { 1481 ret = -EFSCORRUPTED; 1482 goto bad_inode; 1483 } 1484 ei->i_dtime = 0; 1485 inode->i_generation = le32_to_cpu(raw_inode->i_generation); 1486 ei->i_state = 0; 1487 ei->i_block_group = (ino - 1) / EXT2_INODES_PER_GROUP(inode->i_sb); 1488 ei->i_dir_start_lookup = 0; 1489 1490 /* 1491 * NOTE! The in-memory inode i_data array is in little-endian order 1492 * even on big-endian machines: we do NOT byteswap the block numbers! 1493 */ 1494 for (n = 0; n < EXT2_N_BLOCKS; n++) 1495 ei->i_data[n] = raw_inode->i_block[n]; 1496 1497 if (S_ISREG(inode->i_mode)) { 1498 inode->i_op = &ext2_file_inode_operations; 1499 if (test_opt(inode->i_sb, NOBH)) { 1500 inode->i_mapping->a_ops = &ext2_nobh_aops; 1501 inode->i_fop = &ext2_file_operations; 1502 } else { 1503 inode->i_mapping->a_ops = &ext2_aops; 1504 inode->i_fop = &ext2_file_operations; 1505 } 1506 } else if (S_ISDIR(inode->i_mode)) { 1507 inode->i_op = &ext2_dir_inode_operations; 1508 inode->i_fop = &ext2_dir_operations; 1509 if (test_opt(inode->i_sb, NOBH)) 1510 inode->i_mapping->a_ops = &ext2_nobh_aops; 1511 else 1512 inode->i_mapping->a_ops = &ext2_aops; 1513 } else if (S_ISLNK(inode->i_mode)) { 1514 if (ext2_inode_is_fast_symlink(inode)) { 1515 inode->i_link = (char *)ei->i_data; 1516 inode->i_op = &ext2_fast_symlink_inode_operations; 1517 nd_terminate_link(ei->i_data, inode->i_size, 1518 sizeof(ei->i_data) - 1); 1519 } else { 1520 inode->i_op = &ext2_symlink_inode_operations; 1521 inode_nohighmem(inode); 1522 if (test_opt(inode->i_sb, NOBH)) 1523 inode->i_mapping->a_ops = &ext2_nobh_aops; 1524 else 1525 inode->i_mapping->a_ops = &ext2_aops; 1526 } 1527 } else { 1528 inode->i_op = &ext2_special_inode_operations; 1529 if (raw_inode->i_block[0]) 1530 init_special_inode(inode, inode->i_mode, 1531 old_decode_dev(le32_to_cpu(raw_inode->i_block[0]))); 1532 else 1533 init_special_inode(inode, inode->i_mode, 1534 new_decode_dev(le32_to_cpu(raw_inode->i_block[1]))); 1535 } 1536 brelse (bh); 1537 ext2_set_inode_flags(inode); 1538 unlock_new_inode(inode); 1539 return inode; 1540 1541 bad_inode: 1542 iget_failed(inode); 1543 return ERR_PTR(ret); 1544 } 1545 1546 static int __ext2_write_inode(struct inode *inode, int do_sync) 1547 { 1548 struct ext2_inode_info *ei = EXT2_I(inode); 1549 struct super_block *sb = inode->i_sb; 1550 ino_t ino = inode->i_ino; 1551 uid_t uid = i_uid_read(inode); 1552 gid_t gid = i_gid_read(inode); 1553 struct buffer_head * bh; 1554 struct ext2_inode * raw_inode = ext2_get_inode(sb, ino, &bh); 1555 int n; 1556 int err = 0; 1557 1558 if (IS_ERR(raw_inode)) 1559 return -EIO; 1560 1561 /* For fields not not tracking in the in-memory inode, 1562 * initialise them to zero for new inodes. */ 1563 if (ei->i_state & EXT2_STATE_NEW) 1564 memset(raw_inode, 0, EXT2_SB(sb)->s_inode_size); 1565 1566 ext2_get_inode_flags(ei); 1567 raw_inode->i_mode = cpu_to_le16(inode->i_mode); 1568 if (!(test_opt(sb, NO_UID32))) { 1569 raw_inode->i_uid_low = cpu_to_le16(low_16_bits(uid)); 1570 raw_inode->i_gid_low = cpu_to_le16(low_16_bits(gid)); 1571 /* 1572 * Fix up interoperability with old kernels. Otherwise, old inodes get 1573 * re-used with the upper 16 bits of the uid/gid intact 1574 */ 1575 if (!ei->i_dtime) { 1576 raw_inode->i_uid_high = cpu_to_le16(high_16_bits(uid)); 1577 raw_inode->i_gid_high = cpu_to_le16(high_16_bits(gid)); 1578 } else { 1579 raw_inode->i_uid_high = 0; 1580 raw_inode->i_gid_high = 0; 1581 } 1582 } else { 1583 raw_inode->i_uid_low = cpu_to_le16(fs_high2lowuid(uid)); 1584 raw_inode->i_gid_low = cpu_to_le16(fs_high2lowgid(gid)); 1585 raw_inode->i_uid_high = 0; 1586 raw_inode->i_gid_high = 0; 1587 } 1588 raw_inode->i_links_count = cpu_to_le16(inode->i_nlink); 1589 raw_inode->i_size = cpu_to_le32(inode->i_size); 1590 raw_inode->i_atime = cpu_to_le32(inode->i_atime.tv_sec); 1591 raw_inode->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec); 1592 raw_inode->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec); 1593 1594 raw_inode->i_blocks = cpu_to_le32(inode->i_blocks); 1595 raw_inode->i_dtime = cpu_to_le32(ei->i_dtime); 1596 raw_inode->i_flags = cpu_to_le32(ei->i_flags); 1597 raw_inode->i_faddr = cpu_to_le32(ei->i_faddr); 1598 raw_inode->i_frag = ei->i_frag_no; 1599 raw_inode->i_fsize = ei->i_frag_size; 1600 raw_inode->i_file_acl = cpu_to_le32(ei->i_file_acl); 1601 if (!S_ISREG(inode->i_mode)) 1602 raw_inode->i_dir_acl = cpu_to_le32(ei->i_dir_acl); 1603 else { 1604 raw_inode->i_size_high = cpu_to_le32(inode->i_size >> 32); 1605 if (inode->i_size > 0x7fffffffULL) { 1606 if (!EXT2_HAS_RO_COMPAT_FEATURE(sb, 1607 EXT2_FEATURE_RO_COMPAT_LARGE_FILE) || 1608 EXT2_SB(sb)->s_es->s_rev_level == 1609 cpu_to_le32(EXT2_GOOD_OLD_REV)) { 1610 /* If this is the first large file 1611 * created, add a flag to the superblock. 1612 */ 1613 spin_lock(&EXT2_SB(sb)->s_lock); 1614 ext2_update_dynamic_rev(sb); 1615 EXT2_SET_RO_COMPAT_FEATURE(sb, 1616 EXT2_FEATURE_RO_COMPAT_LARGE_FILE); 1617 spin_unlock(&EXT2_SB(sb)->s_lock); 1618 ext2_write_super(sb); 1619 } 1620 } 1621 } 1622 1623 raw_inode->i_generation = cpu_to_le32(inode->i_generation); 1624 if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) { 1625 if (old_valid_dev(inode->i_rdev)) { 1626 raw_inode->i_block[0] = 1627 cpu_to_le32(old_encode_dev(inode->i_rdev)); 1628 raw_inode->i_block[1] = 0; 1629 } else { 1630 raw_inode->i_block[0] = 0; 1631 raw_inode->i_block[1] = 1632 cpu_to_le32(new_encode_dev(inode->i_rdev)); 1633 raw_inode->i_block[2] = 0; 1634 } 1635 } else for (n = 0; n < EXT2_N_BLOCKS; n++) 1636 raw_inode->i_block[n] = ei->i_data[n]; 1637 mark_buffer_dirty(bh); 1638 if (do_sync) { 1639 sync_dirty_buffer(bh); 1640 if (buffer_req(bh) && !buffer_uptodate(bh)) { 1641 printk ("IO error syncing ext2 inode [%s:%08lx]\n", 1642 sb->s_id, (unsigned long) ino); 1643 err = -EIO; 1644 } 1645 } 1646 ei->i_state &= ~EXT2_STATE_NEW; 1647 brelse (bh); 1648 return err; 1649 } 1650 1651 int ext2_write_inode(struct inode *inode, struct writeback_control *wbc) 1652 { 1653 return __ext2_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL); 1654 } 1655 1656 int ext2_setattr(struct dentry *dentry, struct iattr *iattr) 1657 { 1658 struct inode *inode = d_inode(dentry); 1659 int error; 1660 1661 error = setattr_prepare(dentry, iattr); 1662 if (error) 1663 return error; 1664 1665 if (is_quota_modification(inode, iattr)) { 1666 error = dquot_initialize(inode); 1667 if (error) 1668 return error; 1669 } 1670 if ((iattr->ia_valid & ATTR_UID && !uid_eq(iattr->ia_uid, inode->i_uid)) || 1671 (iattr->ia_valid & ATTR_GID && !gid_eq(iattr->ia_gid, inode->i_gid))) { 1672 error = dquot_transfer(inode, iattr); 1673 if (error) 1674 return error; 1675 } 1676 if (iattr->ia_valid & ATTR_SIZE && iattr->ia_size != inode->i_size) { 1677 error = ext2_setsize(inode, iattr->ia_size); 1678 if (error) 1679 return error; 1680 } 1681 setattr_copy(inode, iattr); 1682 if (iattr->ia_valid & ATTR_MODE) 1683 error = posix_acl_chmod(inode, inode->i_mode); 1684 mark_inode_dirty(inode); 1685 1686 return error; 1687 } 1688