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1// SPDX-License-Identifier: GPL-2.02/*3 * linux/fs/ext2/inode.c4 *5 * Copyright (C) 1992, 1993, 1994, 19956 * Remy Card (card@masi.ibp.fr)7 * Laboratoire MASI - Institut Blaise Pascal8 * Universite Pierre et Marie Curie (Paris VI)9 *10 * from11 *12 * linux/fs/minix/inode.c13 *14 * Copyright (C) 1991, 1992 Linus Torvalds15 *16 * Goal-directed block allocation by Stephen Tweedie17 * (sct@dcs.ed.ac.uk), 1993, 199818 * Big-endian to little-endian byte-swapping/bitmaps by19 * David S. Miller (davem@caip.rutgers.edu), 199520 * 64-bit file support on 64-bit platforms by Jakub Jelinek21 * (jj@sunsite.ms.mff.cuni.cz)22 *23 * Assorted race fixes, rewrite of ext2_get_block() by Al Viro, 200024 */25 26#include <linux/time.h>27#include <linux/highuid.h>28#include <linux/pagemap.h>29#include <linux/dax.h>30#include <linux/blkdev.h>31#include <linux/quotaops.h>32#include <linux/writeback.h>33#include <linux/buffer_head.h>34#include <linux/mpage.h>35#include <linux/fiemap.h>36#include <linux/iomap.h>37#include <linux/namei.h>38#include <linux/uio.h>39#include "ext2.h"40#include "acl.h"41#include "xattr.h"42 43static int __ext2_write_inode(struct inode *inode, int do_sync);44 45/*46 * Test whether an inode is a fast symlink.47 */48static inline int ext2_inode_is_fast_symlink(struct inode *inode)49{50 int ea_blocks = EXT2_I(inode)->i_file_acl ?51 (inode->i_sb->s_blocksize >> 9) : 0;52 53 return (S_ISLNK(inode->i_mode) &&54 inode->i_blocks - ea_blocks == 0);55}56 57static void ext2_truncate_blocks(struct inode *inode, loff_t offset);58 59void ext2_write_failed(struct address_space *mapping, loff_t to)60{61 struct inode *inode = mapping->host;62 63 if (to > inode->i_size) {64 truncate_pagecache(inode, inode->i_size);65 ext2_truncate_blocks(inode, inode->i_size);66 }67}68 69/*70 * Called at the last iput() if i_nlink is zero.71 */72void ext2_evict_inode(struct inode * inode)73{74 struct ext2_block_alloc_info *rsv;75 int want_delete = 0;76 77 if (!inode->i_nlink && !is_bad_inode(inode)) {78 want_delete = 1;79 dquot_initialize(inode);80 } else {81 dquot_drop(inode);82 }83 84 truncate_inode_pages_final(&inode->i_data);85 86 if (want_delete) {87 sb_start_intwrite(inode->i_sb);88 /* set dtime */89 EXT2_I(inode)->i_dtime = ktime_get_real_seconds();90 mark_inode_dirty(inode);91 __ext2_write_inode(inode, inode_needs_sync(inode));92 /* truncate to 0 */93 inode->i_size = 0;94 if (inode->i_blocks)95 ext2_truncate_blocks(inode, 0);96 ext2_xattr_delete_inode(inode);97 }98 99 invalidate_inode_buffers(inode);100 clear_inode(inode);101 102 ext2_discard_reservation(inode);103 rsv = EXT2_I(inode)->i_block_alloc_info;104 EXT2_I(inode)->i_block_alloc_info = NULL;105 if (unlikely(rsv))106 kfree(rsv);107 108 if (want_delete) {109 ext2_free_inode(inode);110 sb_end_intwrite(inode->i_sb);111 }112}113 114typedef struct {115 __le32 *p;116 __le32 key;117 struct buffer_head *bh;118} Indirect;119 120static inline void add_chain(Indirect *p, struct buffer_head *bh, __le32 *v)121{122 p->key = *(p->p = v);123 p->bh = bh;124}125 126static inline int verify_chain(Indirect *from, Indirect *to)127{128 while (from <= to && from->key == *from->p)129 from++;130 return (from > to);131}132 133/**134 * ext2_block_to_path - parse the block number into array of offsets135 * @inode: inode in question (we are only interested in its superblock)136 * @i_block: block number to be parsed137 * @offsets: array to store the offsets in138 * @boundary: set this non-zero if the referred-to block is likely to be139 * followed (on disk) by an indirect block.140 * To store the locations of file's data ext2 uses a data structure common141 * for UNIX filesystems - tree of pointers anchored in the inode, with142 * data blocks at leaves and indirect blocks in intermediate nodes.143 * This function translates the block number into path in that tree -144 * return value is the path length and @offsets[n] is the offset of145 * pointer to (n+1)th node in the nth one. If @block is out of range146 * (negative or too large) warning is printed and zero returned.147 *148 * Note: function doesn't find node addresses, so no IO is needed. All149 * we need to know is the capacity of indirect blocks (taken from the150 * inode->i_sb).151 */152 153/*154 * Portability note: the last comparison (check that we fit into triple155 * indirect block) is spelled differently, because otherwise on an156 * architecture with 32-bit longs and 8Kb pages we might get into trouble157 * if our filesystem had 8Kb blocks. We might use long long, but that would158 * kill us on x86. Oh, well, at least the sign propagation does not matter -159 * i_block would have to be negative in the very beginning, so we would not160 * get there at all.161 */162 163static int ext2_block_to_path(struct inode *inode,164 long i_block, int offsets[4], int *boundary)165{166 int ptrs = EXT2_ADDR_PER_BLOCK(inode->i_sb);167 int ptrs_bits = EXT2_ADDR_PER_BLOCK_BITS(inode->i_sb);168 const long direct_blocks = EXT2_NDIR_BLOCKS,169 indirect_blocks = ptrs,170 double_blocks = (1 << (ptrs_bits * 2));171 int n = 0;172 int final = 0;173 174 if (i_block < 0) {175 ext2_msg(inode->i_sb, KERN_WARNING,176 "warning: %s: block < 0", __func__);177 } else if (i_block < direct_blocks) {178 offsets[n++] = i_block;179 final = direct_blocks;180 } else if ( (i_block -= direct_blocks) < indirect_blocks) {181 offsets[n++] = EXT2_IND_BLOCK;182 offsets[n++] = i_block;183 final = ptrs;184 } else if ((i_block -= indirect_blocks) < double_blocks) {185 offsets[n++] = EXT2_DIND_BLOCK;186 offsets[n++] = i_block >> ptrs_bits;187 offsets[n++] = i_block & (ptrs - 1);188 final = ptrs;189 } else if (((i_block -= double_blocks) >> (ptrs_bits * 2)) < ptrs) {190 offsets[n++] = EXT2_TIND_BLOCK;191 offsets[n++] = i_block >> (ptrs_bits * 2);192 offsets[n++] = (i_block >> ptrs_bits) & (ptrs - 1);193 offsets[n++] = i_block & (ptrs - 1);194 final = ptrs;195 } else {196 ext2_msg(inode->i_sb, KERN_WARNING,197 "warning: %s: block is too big", __func__);198 }199 if (boundary)200 *boundary = final - 1 - (i_block & (ptrs - 1));201 202 return n;203}204 205/**206 * ext2_get_branch - read the chain of indirect blocks leading to data207 * @inode: inode in question208 * @depth: depth of the chain (1 - direct pointer, etc.)209 * @offsets: offsets of pointers in inode/indirect blocks210 * @chain: place to store the result211 * @err: here we store the error value212 *213 * Function fills the array of triples <key, p, bh> and returns %NULL214 * if everything went OK or the pointer to the last filled triple215 * (incomplete one) otherwise. Upon the return chain[i].key contains216 * the number of (i+1)-th block in the chain (as it is stored in memory,217 * i.e. little-endian 32-bit), chain[i].p contains the address of that218 * number (it points into struct inode for i==0 and into the bh->b_data219 * for i>0) and chain[i].bh points to the buffer_head of i-th indirect220 * block for i>0 and NULL for i==0. In other words, it holds the block221 * numbers of the chain, addresses they were taken from (and where we can222 * verify that chain did not change) and buffer_heads hosting these223 * numbers.224 *225 * Function stops when it stumbles upon zero pointer (absent block)226 * (pointer to last triple returned, *@err == 0)227 * or when it gets an IO error reading an indirect block228 * (ditto, *@err == -EIO)229 * or when it notices that chain had been changed while it was reading230 * (ditto, *@err == -EAGAIN)231 * or when it reads all @depth-1 indirect blocks successfully and finds232 * the whole chain, all way to the data (returns %NULL, *err == 0).233 */234static Indirect *ext2_get_branch(struct inode *inode,235 int depth,236 int *offsets,237 Indirect chain[4],238 int *err)239{240 struct super_block *sb = inode->i_sb;241 Indirect *p = chain;242 struct buffer_head *bh;243 244 *err = 0;245 /* i_data is not going away, no lock needed */246 add_chain (chain, NULL, EXT2_I(inode)->i_data + *offsets);247 if (!p->key)248 goto no_block;249 while (--depth) {250 bh = sb_bread(sb, le32_to_cpu(p->key));251 if (!bh)252 goto failure;253 read_lock(&EXT2_I(inode)->i_meta_lock);254 if (!verify_chain(chain, p))255 goto changed;256 add_chain(++p, bh, (__le32*)bh->b_data + *++offsets);257 read_unlock(&EXT2_I(inode)->i_meta_lock);258 if (!p->key)259 goto no_block;260 }261 return NULL;262 263changed:264 read_unlock(&EXT2_I(inode)->i_meta_lock);265 brelse(bh);266 *err = -EAGAIN;267 goto no_block;268failure:269 *err = -EIO;270no_block:271 return p;272}273 274/**275 * ext2_find_near - find a place for allocation with sufficient locality276 * @inode: owner277 * @ind: descriptor of indirect block.278 *279 * This function returns the preferred place for block allocation.280 * It is used when heuristic for sequential allocation fails.281 * Rules are:282 * + if there is a block to the left of our position - allocate near it.283 * + if pointer will live in indirect block - allocate near that block.284 * + if pointer will live in inode - allocate in the same cylinder group.285 *286 * In the latter case we colour the starting block by the callers PID to287 * prevent it from clashing with concurrent allocations for a different inode288 * in the same block group. The PID is used here so that functionally related289 * files will be close-by on-disk.290 *291 * Caller must make sure that @ind is valid and will stay that way.292 */293 294static ext2_fsblk_t ext2_find_near(struct inode *inode, Indirect *ind)295{296 struct ext2_inode_info *ei = EXT2_I(inode);297 __le32 *start = ind->bh ? (__le32 *) ind->bh->b_data : ei->i_data;298 __le32 *p;299 ext2_fsblk_t bg_start;300 ext2_fsblk_t colour;301 302 /* Try to find previous block */303 for (p = ind->p - 1; p >= start; p--)304 if (*p)305 return le32_to_cpu(*p);306 307 /* No such thing, so let's try location of indirect block */308 if (ind->bh)309 return ind->bh->b_blocknr;310 311 /*312 * It is going to be referred from inode itself? OK, just put it into313 * the same cylinder group then.314 */315 bg_start = ext2_group_first_block_no(inode->i_sb, ei->i_block_group);316 colour = (current->pid % 16) *317 (EXT2_BLOCKS_PER_GROUP(inode->i_sb) / 16);318 return bg_start + colour;319}320 321/**322 * ext2_find_goal - find a preferred place for allocation.323 * @inode: owner324 * @block: block we want325 * @partial: pointer to the last triple within a chain326 *327 * Returns preferred place for a block (the goal).328 */329 330static inline ext2_fsblk_t ext2_find_goal(struct inode *inode, long block,331 Indirect *partial)332{333 struct ext2_block_alloc_info *block_i;334 335 block_i = EXT2_I(inode)->i_block_alloc_info;336 337 /*338 * try the heuristic for sequential allocation,339 * failing that at least try to get decent locality.340 */341 if (block_i && (block == block_i->last_alloc_logical_block + 1)342 && (block_i->last_alloc_physical_block != 0)) {343 return block_i->last_alloc_physical_block + 1;344 }345 346 return ext2_find_near(inode, partial);347}348 349/**350 * ext2_blks_to_allocate: Look up the block map and count the number351 * of direct blocks need to be allocated for the given branch.352 *353 * @branch: chain of indirect blocks354 * @k: number of blocks need for indirect blocks355 * @blks: number of data blocks to be mapped.356 * @blocks_to_boundary: the offset in the indirect block357 *358 * return the number of direct blocks to allocate.359 */360static int361ext2_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 yet368 * then it's clear blocks on that path have not allocated369 */370 if (k > 0) {371 /* right now don't hanel cross boundary allocation */372 if (blks < blocks_to_boundary + 1)373 count += blks;374 else375 count += blocks_to_boundary + 1;376 return count;377 }378 379 count++;380 while (count < blks && count <= blocks_to_boundary381 && le32_to_cpu(*(branch[0].p + count)) == 0) {382 count++;383 }384 return count;385}386 387/**388 * ext2_alloc_blocks: Allocate multiple blocks needed for a branch.389 * @inode: Owner.390 * @goal: Preferred place for allocation.391 * @indirect_blks: The number of blocks needed to allocate for indirect blocks.392 * @blks: The number of blocks need to allocate for direct blocks.393 * @new_blocks: On return it will store the new block numbers for394 * the indirect blocks(if needed) and the first direct block.395 * @err: Error pointer.396 *397 * Return: Number of blocks allocated.398 */399static int ext2_alloc_blocks(struct inode *inode,400 ext2_fsblk_t goal, int indirect_blks, int blks,401 ext2_fsblk_t new_blocks[4], int *err)402{403 int target, i;404 unsigned long count = 0;405 int index = 0;406 ext2_fsblk_t current_block = 0;407 int ret = 0;408 409 /*410 * Here we try to allocate the requested multiple blocks at once,411 * on a best-effort basis.412 * To build a branch, we should allocate blocks for413 * the indirect blocks(if not allocated yet), and at least414 * the first direct block of this branch. That's the415 * minimum number of blocks need to allocate(required)416 */417 target = blks + indirect_blks;418 419 while (1) {420 count = target;421 /* allocating blocks for indirect blocks and direct blocks */422 current_block = ext2_new_blocks(inode, goal, &count, err, 0);423 if (*err)424 goto failed_out;425 426 target -= count;427 /* allocate blocks for indirect blocks */428 while (index < indirect_blks && count) {429 new_blocks[index++] = current_block++;430 count--;431 }432 433 if (count > 0)434 break;435 }436 437 /* save the new block number for the first direct block */438 new_blocks[index] = current_block;439 440 /* total number of blocks allocated for direct blocks */441 ret = count;442 *err = 0;443 return ret;444failed_out:445 for (i = 0; i <index; i++)446 ext2_free_blocks(inode, new_blocks[i], 1);447 if (index)448 mark_inode_dirty(inode);449 return ret;450}451 452/**453 * ext2_alloc_branch - allocate and set up a chain of blocks.454 * @inode: owner455 * @indirect_blks: depth of the chain (number of blocks to allocate)456 * @blks: number of allocated direct blocks457 * @goal: preferred place for allocation458 * @offsets: offsets (in the blocks) to store the pointers to next.459 * @branch: place to store the chain in.460 *461 * This function allocates @num blocks, zeroes out all but the last one,462 * links them into chain and (if we are synchronous) writes them to disk.463 * In other words, it prepares a branch that can be spliced onto the464 * inode. It stores the information about that chain in the branch[], in465 * the same format as ext2_get_branch() would do. We are calling it after466 * we had read the existing part of chain and partial points to the last467 * triple of that (one with zero ->key). Upon the exit we have the same468 * picture as after the successful ext2_get_block(), except that in one469 * place chain is disconnected - *branch->p is still zero (we did not470 * set the last link), but branch->key contains the number that should471 * be placed into *branch->p to fill that gap.472 *473 * If allocation fails we free all blocks we've allocated (and forget474 * their buffer_heads) and return the error value the from failed475 * ext2_alloc_block() (normally -ENOSPC). Otherwise we set the chain476 * as described above and return 0.477 */478 479static int ext2_alloc_branch(struct inode *inode,480 int indirect_blks, int *blks, ext2_fsblk_t goal,481 int *offsets, Indirect *branch)482{483 int blocksize = inode->i_sb->s_blocksize;484 int i, n = 0;485 int err = 0;486 struct buffer_head *bh;487 int num;488 ext2_fsblk_t new_blocks[4];489 ext2_fsblk_t current_block;490 491 num = ext2_alloc_blocks(inode, goal, indirect_blks,492 *blks, new_blocks, &err);493 if (err)494 return err;495 496 branch[0].key = cpu_to_le32(new_blocks[0]);497 /*498 * metadata blocks and data blocks are allocated.499 */500 for (n = 1; n <= indirect_blks; n++) {501 /*502 * Get buffer_head for parent block, zero it out503 * and set the pointer to new one, then send504 * parent to disk.505 */506 bh = sb_getblk(inode->i_sb, new_blocks[n-1]);507 if (unlikely(!bh)) {508 err = -ENOMEM;509 goto failed;510 }511 branch[n].bh = bh;512 lock_buffer(bh);513 memset(bh->b_data, 0, blocksize);514 branch[n].p = (__le32 *) bh->b_data + offsets[n];515 branch[n].key = cpu_to_le32(new_blocks[n]);516 *branch[n].p = branch[n].key;517 if ( n == indirect_blks) {518 current_block = new_blocks[n];519 /*520 * End of chain, update the last new metablock of521 * the chain to point to the new allocated522 * data blocks numbers523 */524 for (i=1; i < num; i++)525 *(branch[n].p + i) = cpu_to_le32(++current_block);526 }527 set_buffer_uptodate(bh);528 unlock_buffer(bh);529 mark_buffer_dirty_inode(bh, inode);530 /* We used to sync bh here if IS_SYNC(inode).531 * But we now rely upon generic_write_sync()532 * and b_inode_buffers. But not for directories.533 */534 if (S_ISDIR(inode->i_mode) && IS_DIRSYNC(inode))535 sync_dirty_buffer(bh);536 }537 *blks = num;538 return err;539 540failed:541 for (i = 1; i < n; i++)542 bforget(branch[i].bh);543 for (i = 0; i < indirect_blks; i++)544 ext2_free_blocks(inode, new_blocks[i], 1);545 ext2_free_blocks(inode, new_blocks[i], num);546 return err;547}548 549/**550 * ext2_splice_branch - splice the allocated branch onto inode.551 * @inode: owner552 * @block: (logical) number of block we are adding553 * @where: location of missing link554 * @num: number of indirect blocks we are adding555 * @blks: number of direct blocks we are adding556 *557 * This function fills the missing link and does all housekeeping needed in558 * inode (->i_blocks, etc.). In case of success we end up with the full559 * chain to new block and return 0.560 */561static void ext2_splice_branch(struct inode *inode,562 long block, Indirect *where, int num, int blks)563{564 int i;565 struct ext2_block_alloc_info *block_i;566 ext2_fsblk_t current_block;567 568 block_i = EXT2_I(inode)->i_block_alloc_info;569 570 /* XXX LOCKING probably should have i_meta_lock ?*/571 /* That's it */572 573 *where->p = where->key;574 575 /*576 * Update the host buffer_head or inode to point to more just allocated577 * direct blocks blocks578 */579 if (num == 0 && blks > 1) {580 current_block = le32_to_cpu(where->key) + 1;581 for (i = 1; i < blks; i++)582 *(where->p + i ) = cpu_to_le32(current_block++);583 }584 585 /*586 * update the most recently allocated logical & physical block587 * in i_block_alloc_info, to assist find the proper goal block for next588 * allocation589 */590 if (block_i) {591 block_i->last_alloc_logical_block = block + blks - 1;592 block_i->last_alloc_physical_block =593 le32_to_cpu(where[num].key) + blks - 1;594 }595 596 /* We are done with atomic stuff, now do the rest of housekeeping */597 598 /* had we spliced it onto indirect block? */599 if (where->bh)600 mark_buffer_dirty_inode(where->bh, inode);601 602 inode_set_ctime_current(inode);603 mark_inode_dirty(inode);604}605 606/*607 * Allocation strategy is simple: if we have to allocate something, we will608 * have to go the whole way to leaf. So let's do it before attaching anything609 * to tree, set linkage between the newborn blocks, write them if sync is610 * required, recheck the path, free and repeat if check fails, otherwise611 * set the last missing link (that will protect us from any truncate-generated612 * removals - all blocks on the path are immune now) and possibly force the613 * write on the parent block.614 * That has a nice additional property: no special recovery from the failed615 * allocations is needed - we simply release blocks and do not touch anything616 * reachable from inode.617 *618 * `handle' can be NULL if create == 0.619 *620 * return > 0, # of blocks mapped or allocated.621 * return = 0, if plain lookup failed.622 * return < 0, error case.623 */624static int ext2_get_blocks(struct inode *inode,625 sector_t iblock, unsigned long maxblocks,626 u32 *bno, bool *new, bool *boundary,627 int create)628{629 int err;630 int offsets[4];631 Indirect chain[4];632 Indirect *partial;633 ext2_fsblk_t goal;634 int indirect_blks;635 int blocks_to_boundary = 0;636 int depth;637 struct ext2_inode_info *ei = EXT2_I(inode);638 int count = 0;639 ext2_fsblk_t first_block = 0;640 641 BUG_ON(maxblocks == 0);642 643 depth = ext2_block_to_path(inode,iblock,offsets,&blocks_to_boundary);644 645 if (depth == 0)646 return -EIO;647 648 partial = ext2_get_branch(inode, depth, offsets, chain, &err);649 /* Simplest case - block found, no allocation needed */650 if (!partial) {651 first_block = le32_to_cpu(chain[depth - 1].key);652 count++;653 /*map more blocks*/654 while (count < maxblocks && count <= blocks_to_boundary) {655 ext2_fsblk_t blk;656 657 if (!verify_chain(chain, chain + depth - 1)) {658 /*659 * Indirect block might be removed by660 * truncate while we were reading it.661 * Handling of that case: forget what we've662 * got now, go to reread.663 */664 err = -EAGAIN;665 count = 0;666 partial = chain + depth - 1;667 break;668 }669 blk = le32_to_cpu(*(chain[depth-1].p + count));670 if (blk == first_block + count)671 count++;672 else673 break;674 }675 if (err != -EAGAIN)676 goto got_it;677 }678 679 /* Next simple case - plain lookup or failed read of indirect block */680 if (!create || err == -EIO)681 goto cleanup;682 683 mutex_lock(&ei->truncate_mutex);684 /*685 * If the indirect block is missing while we are reading686 * the chain(ext2_get_branch() returns -EAGAIN err), or687 * if the chain has been changed after we grab the semaphore,688 * (either because another process truncated this branch, or689 * another get_block allocated this branch) re-grab the chain to see if690 * the request block has been allocated or not.691 *692 * Since we already block the truncate/other get_block693 * at this point, we will have the current copy of the chain when we694 * splice the branch into the tree.695 */696 if (err == -EAGAIN || !verify_chain(chain, partial)) {697 while (partial > chain) {698 brelse(partial->bh);699 partial--;700 }701 partial = ext2_get_branch(inode, depth, offsets, chain, &err);702 if (!partial) {703 count++;704 mutex_unlock(&ei->truncate_mutex);705 goto got_it;706 }707 708 if (err) {709 mutex_unlock(&ei->truncate_mutex);710 goto cleanup;711 }712 }713 714 /*715 * Okay, we need to do block allocation. Lazily initialize the block716 * allocation info here if necessary717 */718 if (S_ISREG(inode->i_mode) && (!ei->i_block_alloc_info))719 ext2_init_block_alloc_info(inode);720 721 goal = ext2_find_goal(inode, iblock, partial);722 723 /* the number of blocks need to allocate for [d,t]indirect blocks */724 indirect_blks = (chain + depth) - partial - 1;725 /*726 * Next look up the indirect map to count the total number of727 * direct blocks to allocate for this branch.728 */729 count = ext2_blks_to_allocate(partial, indirect_blks,730 maxblocks, blocks_to_boundary);731 /*732 * XXX ???? Block out ext2_truncate while we alter the tree733 */734 err = ext2_alloc_branch(inode, indirect_blks, &count, goal,735 offsets + (partial - chain), partial);736 737 if (err) {738 mutex_unlock(&ei->truncate_mutex);739 goto cleanup;740 }741 742 if (IS_DAX(inode)) {743 /*744 * We must unmap blocks before zeroing so that writeback cannot745 * overwrite zeros with stale data from block device page cache.746 */747 clean_bdev_aliases(inode->i_sb->s_bdev,748 le32_to_cpu(chain[depth-1].key),749 count);750 /*751 * block must be initialised before we put it in the tree752 * so that it's not found by another thread before it's753 * initialised754 */755 err = sb_issue_zeroout(inode->i_sb,756 le32_to_cpu(chain[depth-1].key), count,757 GFP_KERNEL);758 if (err) {759 mutex_unlock(&ei->truncate_mutex);760 goto cleanup;761 }762 }763 *new = true;764 765 ext2_splice_branch(inode, iblock, partial, indirect_blks, count);766 mutex_unlock(&ei->truncate_mutex);767got_it:768 if (count > blocks_to_boundary)769 *boundary = true;770 err = count;771 /* Clean up and exit */772 partial = chain + depth - 1; /* the whole chain */773cleanup:774 while (partial > chain) {775 brelse(partial->bh);776 partial--;777 }778 if (err > 0)779 *bno = le32_to_cpu(chain[depth-1].key);780 return err;781}782 783int ext2_get_block(struct inode *inode, sector_t iblock,784 struct buffer_head *bh_result, int create)785{786 unsigned max_blocks = bh_result->b_size >> inode->i_blkbits;787 bool new = false, boundary = false;788 u32 bno;789 int ret;790 791 ret = ext2_get_blocks(inode, iblock, max_blocks, &bno, &new, &boundary,792 create);793 if (ret <= 0)794 return ret;795 796 map_bh(bh_result, inode->i_sb, bno);797 bh_result->b_size = (ret << inode->i_blkbits);798 if (new)799 set_buffer_new(bh_result);800 if (boundary)801 set_buffer_boundary(bh_result);802 return 0;803 804}805 806static int ext2_iomap_begin(struct inode *inode, loff_t offset, loff_t length,807 unsigned flags, struct iomap *iomap, struct iomap *srcmap)808{809 unsigned int blkbits = inode->i_blkbits;810 unsigned long first_block = offset >> blkbits;811 unsigned long max_blocks = (length + (1 << blkbits) - 1) >> blkbits;812 struct ext2_sb_info *sbi = EXT2_SB(inode->i_sb);813 bool new = false, boundary = false;814 u32 bno;815 int ret;816 bool create = flags & IOMAP_WRITE;817 818 /*819 * For writes that could fill holes inside i_size on a820 * DIO_SKIP_HOLES filesystem we forbid block creations: only821 * overwrites are permitted.822 */823 if ((flags & IOMAP_DIRECT) &&824 (first_block << blkbits) < i_size_read(inode))825 create = 0;826 827 /*828 * Writes that span EOF might trigger an IO size update on completion,829 * so consider them to be dirty for the purposes of O_DSYNC even if830 * there is no other metadata changes pending or have been made here.831 */832 if ((flags & IOMAP_WRITE) && offset + length > i_size_read(inode))833 iomap->flags |= IOMAP_F_DIRTY;834 835 ret = ext2_get_blocks(inode, first_block, max_blocks,836 &bno, &new, &boundary, create);837 if (ret < 0)838 return ret;839 840 iomap->flags = 0;841 iomap->offset = (u64)first_block << blkbits;842 if (flags & IOMAP_DAX)843 iomap->dax_dev = sbi->s_daxdev;844 else845 iomap->bdev = inode->i_sb->s_bdev;846 847 if (ret == 0) {848 /*849 * Switch to buffered-io for writing to holes in a non-extent850 * based filesystem to avoid stale data exposure problem.851 */852 if (!create && (flags & IOMAP_WRITE) && (flags & IOMAP_DIRECT))853 return -ENOTBLK;854 iomap->type = IOMAP_HOLE;855 iomap->addr = IOMAP_NULL_ADDR;856 iomap->length = 1 << blkbits;857 } else {858 iomap->type = IOMAP_MAPPED;859 iomap->addr = (u64)bno << blkbits;860 if (flags & IOMAP_DAX)861 iomap->addr += sbi->s_dax_part_off;862 iomap->length = (u64)ret << blkbits;863 iomap->flags |= IOMAP_F_MERGED;864 }865 866 if (new)867 iomap->flags |= IOMAP_F_NEW;868 return 0;869}870 871static int872ext2_iomap_end(struct inode *inode, loff_t offset, loff_t length,873 ssize_t written, unsigned flags, struct iomap *iomap)874{875 /*876 * Switch to buffered-io in case of any error.877 * Blocks allocated can be used by the buffered-io path.878 */879 if ((flags & IOMAP_DIRECT) && (flags & IOMAP_WRITE) && written == 0)880 return -ENOTBLK;881 882 if (iomap->type == IOMAP_MAPPED &&883 written < length &&884 (flags & IOMAP_WRITE))885 ext2_write_failed(inode->i_mapping, offset + length);886 return 0;887}888 889const struct iomap_ops ext2_iomap_ops = {890 .iomap_begin = ext2_iomap_begin,891 .iomap_end = ext2_iomap_end,892};893 894int ext2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,895 u64 start, u64 len)896{897 int ret;898 899 inode_lock(inode);900 len = min_t(u64, len, i_size_read(inode));901 ret = iomap_fiemap(inode, fieinfo, start, len, &ext2_iomap_ops);902 inode_unlock(inode);903 904 return ret;905}906 907static int ext2_read_folio(struct file *file, struct folio *folio)908{909 return mpage_read_folio(folio, ext2_get_block);910}911 912static void ext2_readahead(struct readahead_control *rac)913{914 mpage_readahead(rac, ext2_get_block);915}916 917static int918ext2_write_begin(struct file *file, struct address_space *mapping,919 loff_t pos, unsigned len, struct folio **foliop, void **fsdata)920{921 int ret;922 923 ret = block_write_begin(mapping, pos, len, foliop, ext2_get_block);924 if (ret < 0)925 ext2_write_failed(mapping, pos + len);926 return ret;927}928 929static int ext2_write_end(struct file *file, struct address_space *mapping,930 loff_t pos, unsigned len, unsigned copied,931 struct folio *folio, void *fsdata)932{933 int ret;934 935 ret = generic_write_end(file, mapping, pos, len, copied, folio, fsdata);936 if (ret < len)937 ext2_write_failed(mapping, pos + len);938 return ret;939}940 941static sector_t ext2_bmap(struct address_space *mapping, sector_t block)942{943 return generic_block_bmap(mapping,block,ext2_get_block);944}945 946static int947ext2_writepages(struct address_space *mapping, struct writeback_control *wbc)948{949 return mpage_writepages(mapping, wbc, ext2_get_block);950}951 952static int953ext2_dax_writepages(struct address_space *mapping, struct writeback_control *wbc)954{955 struct ext2_sb_info *sbi = EXT2_SB(mapping->host->i_sb);956 957 return dax_writeback_mapping_range(mapping, sbi->s_daxdev, wbc);958}959 960const struct address_space_operations ext2_aops = {961 .dirty_folio = block_dirty_folio,962 .invalidate_folio = block_invalidate_folio,963 .read_folio = ext2_read_folio,964 .readahead = ext2_readahead,965 .write_begin = ext2_write_begin,966 .write_end = ext2_write_end,967 .bmap = ext2_bmap,968 .writepages = ext2_writepages,969 .migrate_folio = buffer_migrate_folio,970 .is_partially_uptodate = block_is_partially_uptodate,971 .error_remove_folio = generic_error_remove_folio,972};973 974static const struct address_space_operations ext2_dax_aops = {975 .writepages = ext2_dax_writepages,976 .dirty_folio = noop_dirty_folio,977};978 979/*980 * Probably it should be a library function... search for first non-zero word981 * or memcmp with zero_page, whatever is better for particular architecture.982 * Linus?983 */984static inline int all_zeroes(__le32 *p, __le32 *q)985{986 while (p < q)987 if (*p++)988 return 0;989 return 1;990}991 992/**993 * ext2_find_shared - find the indirect blocks for partial truncation.994 * @inode: inode in question995 * @depth: depth of the affected branch996 * @offsets: offsets of pointers in that branch (see ext2_block_to_path)997 * @chain: place to store the pointers to partial indirect blocks998 * @top: place to the (detached) top of branch999 *1000 * This is a helper function used by ext2_truncate().1001 *1002 * When we do truncate() we may have to clean the ends of several indirect1003 * blocks but leave the blocks themselves alive. Block is partially1004 * truncated if some data below the new i_size is referred from it (and1005 * it is on the path to the first completely truncated data block, indeed).1006 * We have to free the top of that path along with everything to the right1007 * of the path. Since no allocation past the truncation point is possible1008 * until ext2_truncate() finishes, we may safely do the latter, but top1009 * of branch may require special attention - pageout below the truncation1010 * point might try to populate it.1011 *1012 * We atomically detach the top of branch from the tree, store the block1013 * number of its root in *@top, pointers to buffer_heads of partially1014 * truncated blocks - in @chain[].bh and pointers to their last elements1015 * that should not be removed - in @chain[].p. Return value is the pointer1016 * to last filled element of @chain.1017 *1018 * The work left to caller to do the actual freeing of subtrees:1019 * a) free the subtree starting from *@top1020 * b) free the subtrees whose roots are stored in1021 * (@chain[i].p+1 .. end of @chain[i].bh->b_data)1022 * c) free the subtrees growing from the inode past the @chain[0].p1023 * (no partially truncated stuff there).1024 */1025 1026static Indirect *ext2_find_shared(struct inode *inode,1027 int depth,1028 int offsets[4],1029 Indirect chain[4],1030 __le32 *top)1031{1032 Indirect *partial, *p;1033 int k, err;1034 1035 *top = 0;1036 for (k = depth; k > 1 && !offsets[k-1]; k--)1037 ;1038 partial = ext2_get_branch(inode, k, offsets, chain, &err);1039 if (!partial)1040 partial = chain + k-1;1041 /*1042 * If the branch acquired continuation since we've looked at it -1043 * fine, it should all survive and (new) top doesn't belong to us.1044 */1045 write_lock(&EXT2_I(inode)->i_meta_lock);1046 if (!partial->key && *partial->p) {1047 write_unlock(&EXT2_I(inode)->i_meta_lock);1048 goto no_top;1049 }1050 for (p=partial; p>chain && all_zeroes((__le32*)p->bh->b_data,p->p); p--)1051 ;1052 /*1053 * OK, we've found the last block that must survive. The rest of our1054 * branch should be detached before unlocking. However, if that rest1055 * of branch is all ours and does not grow immediately from the inode1056 * it's easier to cheat and just decrement partial->p.1057 */1058 if (p == chain + k - 1 && p > chain) {1059 p->p--;1060 } else {1061 *top = *p->p;1062 *p->p = 0;1063 }1064 write_unlock(&EXT2_I(inode)->i_meta_lock);1065 1066 while(partial > p)1067 {1068 brelse(partial->bh);1069 partial--;1070 }1071no_top:1072 return partial;1073}1074 1075/**1076 * ext2_free_data - free a list of data blocks1077 * @inode: inode we are dealing with1078 * @p: array of block numbers1079 * @q: points immediately past the end of array1080 *1081 * We are freeing all blocks referred from that array (numbers are1082 * stored as little-endian 32-bit) and updating @inode->i_blocks1083 * appropriately.1084 */1085static inline void ext2_free_data(struct inode *inode, __le32 *p, __le32 *q)1086{1087 ext2_fsblk_t block_to_free = 0, count = 0;1088 ext2_fsblk_t nr;1089 1090 for ( ; p < q ; p++) {1091 nr = le32_to_cpu(*p);1092 if (nr) {1093 *p = 0;1094 /* accumulate blocks to free if they're contiguous */1095 if (count == 0)1096 goto free_this;1097 else if (block_to_free == nr - count)1098 count++;1099 else {1100 ext2_free_blocks (inode, block_to_free, count);1101 mark_inode_dirty(inode);1102 free_this:1103 block_to_free = nr;1104 count = 1;1105 }1106 }1107 }1108 if (count > 0) {1109 ext2_free_blocks (inode, block_to_free, count);1110 mark_inode_dirty(inode);1111 }1112}1113 1114/**1115 * ext2_free_branches - free an array of branches1116 * @inode: inode we are dealing with1117 * @p: array of block numbers1118 * @q: pointer immediately past the end of array1119 * @depth: depth of the branches to free1120 *1121 * We are freeing all blocks referred from these branches (numbers are1122 * stored as little-endian 32-bit) and updating @inode->i_blocks1123 * appropriately.1124 */1125static void ext2_free_branches(struct inode *inode, __le32 *p, __le32 *q, int depth)1126{1127 struct buffer_head * bh;1128 ext2_fsblk_t nr;1129 1130 if (depth--) {1131 int addr_per_block = EXT2_ADDR_PER_BLOCK(inode->i_sb);1132 for ( ; p < q ; p++) {1133 nr = le32_to_cpu(*p);1134 if (!nr)1135 continue;1136 *p = 0;1137 bh = sb_bread(inode->i_sb, nr);1138 /*1139 * A read failure? Report error and clear slot1140 * (should be rare).1141 */ 1142 if (!bh) {1143 ext2_error(inode->i_sb, "ext2_free_branches",1144 "Read failure, inode=%ld, block=%ld",1145 inode->i_ino, nr);1146 continue;1147 }1148 ext2_free_branches(inode,1149 (__le32*)bh->b_data,1150 (__le32*)bh->b_data + addr_per_block,1151 depth);1152 bforget(bh);1153 ext2_free_blocks(inode, nr, 1);1154 mark_inode_dirty(inode);1155 }1156 } else1157 ext2_free_data(inode, p, q);1158}1159 1160/* mapping->invalidate_lock must be held when calling this function */1161static void __ext2_truncate_blocks(struct inode *inode, loff_t offset)1162{1163 __le32 *i_data = EXT2_I(inode)->i_data;1164 struct ext2_inode_info *ei = EXT2_I(inode);1165 int addr_per_block = EXT2_ADDR_PER_BLOCK(inode->i_sb);1166 int offsets[4];1167 Indirect chain[4];1168 Indirect *partial;1169 __le32 nr = 0;1170 int n;1171 long iblock;1172 unsigned blocksize;1173 blocksize = inode->i_sb->s_blocksize;1174 iblock = (offset + blocksize-1) >> EXT2_BLOCK_SIZE_BITS(inode->i_sb);1175 1176#ifdef CONFIG_FS_DAX1177 WARN_ON(!rwsem_is_locked(&inode->i_mapping->invalidate_lock));1178#endif1179 1180 n = ext2_block_to_path(inode, iblock, offsets, NULL);1181 if (n == 0)1182 return;1183 1184 /*1185 * From here we block out all ext2_get_block() callers who want to1186 * modify the block allocation tree.1187 */1188 mutex_lock(&ei->truncate_mutex);1189 1190 if (n == 1) {1191 ext2_free_data(inode, i_data+offsets[0],1192 i_data + EXT2_NDIR_BLOCKS);1193 goto do_indirects;1194 }1195 1196 partial = ext2_find_shared(inode, n, offsets, chain, &nr);1197 /* Kill the top of shared branch (already detached) */1198 if (nr) {1199 if (partial == chain)1200 mark_inode_dirty(inode);1201 else1202 mark_buffer_dirty_inode(partial->bh, inode);1203 ext2_free_branches(inode, &nr, &nr+1, (chain+n-1) - partial);1204 }1205 /* Clear the ends of indirect blocks on the shared branch */1206 while (partial > chain) {1207 ext2_free_branches(inode,1208 partial->p + 1,1209 (__le32*)partial->bh->b_data+addr_per_block,1210 (chain+n-1) - partial);1211 mark_buffer_dirty_inode(partial->bh, inode);1212 brelse (partial->bh);1213 partial--;1214 }1215do_indirects:1216 /* Kill the remaining (whole) subtrees */1217 switch (offsets[0]) {1218 default:1219 nr = i_data[EXT2_IND_BLOCK];1220 if (nr) {1221 i_data[EXT2_IND_BLOCK] = 0;1222 mark_inode_dirty(inode);1223 ext2_free_branches(inode, &nr, &nr+1, 1);1224 }1225 fallthrough;1226 case EXT2_IND_BLOCK:1227 nr = i_data[EXT2_DIND_BLOCK];1228 if (nr) {1229 i_data[EXT2_DIND_BLOCK] = 0;1230 mark_inode_dirty(inode);1231 ext2_free_branches(inode, &nr, &nr+1, 2);1232 }1233 fallthrough;1234 case EXT2_DIND_BLOCK:1235 nr = i_data[EXT2_TIND_BLOCK];1236 if (nr) {1237 i_data[EXT2_TIND_BLOCK] = 0;1238 mark_inode_dirty(inode);1239 ext2_free_branches(inode, &nr, &nr+1, 3);1240 }1241 break;1242 case EXT2_TIND_BLOCK:1243 ;1244 }1245 1246 ext2_discard_reservation(inode);1247 1248 mutex_unlock(&ei->truncate_mutex);1249}1250 1251static void ext2_truncate_blocks(struct inode *inode, loff_t offset)1252{1253 if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||1254 S_ISLNK(inode->i_mode)))1255 return;1256 if (ext2_inode_is_fast_symlink(inode))1257 return;1258 1259 filemap_invalidate_lock(inode->i_mapping);1260 __ext2_truncate_blocks(inode, offset);1261 filemap_invalidate_unlock(inode->i_mapping);1262}1263 1264static int ext2_setsize(struct inode *inode, loff_t newsize)1265{1266 int error;1267 1268 if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||1269 S_ISLNK(inode->i_mode)))1270 return -EINVAL;1271 if (ext2_inode_is_fast_symlink(inode))1272 return -EINVAL;1273 if (IS_APPEND(inode) || IS_IMMUTABLE(inode))1274 return -EPERM;1275 1276 inode_dio_wait(inode);1277 1278 if (IS_DAX(inode))1279 error = dax_truncate_page(inode, newsize, NULL,1280 &ext2_iomap_ops);1281 else1282 error = block_truncate_page(inode->i_mapping,1283 newsize, ext2_get_block);1284 if (error)1285 return error;1286 1287 filemap_invalidate_lock(inode->i_mapping);1288 truncate_setsize(inode, newsize);1289 __ext2_truncate_blocks(inode, newsize);1290 filemap_invalidate_unlock(inode->i_mapping);1291 1292 inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode));1293 if (inode_needs_sync(inode)) {1294 sync_mapping_buffers(inode->i_mapping);1295 sync_inode_metadata(inode, 1);1296 } else {1297 mark_inode_dirty(inode);1298 }1299 1300 return 0;1301}1302 1303static struct ext2_inode *ext2_get_inode(struct super_block *sb, ino_t ino,1304 struct buffer_head **p)1305{1306 struct buffer_head * bh;1307 unsigned long block_group;1308 unsigned long block;1309 unsigned long offset;1310 struct ext2_group_desc * gdp;1311 1312 *p = NULL;1313 if ((ino != EXT2_ROOT_INO && ino < EXT2_FIRST_INO(sb)) ||1314 ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count))1315 goto Einval;1316 1317 block_group = (ino - 1) / EXT2_INODES_PER_GROUP(sb);1318 gdp = ext2_get_group_desc(sb, block_group, NULL);1319 if (!gdp)1320 goto Egdp;1321 /*1322 * Figure out the offset within the block group inode table1323 */1324 offset = ((ino - 1) % EXT2_INODES_PER_GROUP(sb)) * EXT2_INODE_SIZE(sb);1325 block = le32_to_cpu(gdp->bg_inode_table) +1326 (offset >> EXT2_BLOCK_SIZE_BITS(sb));1327 if (!(bh = sb_bread(sb, block)))1328 goto Eio;1329 1330 *p = bh;1331 offset &= (EXT2_BLOCK_SIZE(sb) - 1);1332 return (struct ext2_inode *) (bh->b_data + offset);1333 1334Einval:1335 ext2_error(sb, "ext2_get_inode", "bad inode number: %lu",1336 (unsigned long) ino);1337 return ERR_PTR(-EINVAL);1338Eio:1339 ext2_error(sb, "ext2_get_inode",1340 "unable to read inode block - inode=%lu, block=%lu",1341 (unsigned long) ino, block);1342Egdp:1343 return ERR_PTR(-EIO);1344}1345 1346void ext2_set_inode_flags(struct inode *inode)1347{1348 unsigned int flags = EXT2_I(inode)->i_flags;1349 1350 inode->i_flags &= ~(S_SYNC | S_APPEND | S_IMMUTABLE | S_NOATIME |1351 S_DIRSYNC | S_DAX);1352 if (flags & EXT2_SYNC_FL)1353 inode->i_flags |= S_SYNC;1354 if (flags & EXT2_APPEND_FL)1355 inode->i_flags |= S_APPEND;1356 if (flags & EXT2_IMMUTABLE_FL)1357 inode->i_flags |= S_IMMUTABLE;1358 if (flags & EXT2_NOATIME_FL)1359 inode->i_flags |= S_NOATIME;1360 if (flags & EXT2_DIRSYNC_FL)1361 inode->i_flags |= S_DIRSYNC;1362 if (test_opt(inode->i_sb, DAX) && S_ISREG(inode->i_mode))1363 inode->i_flags |= S_DAX;1364}1365 1366void ext2_set_file_ops(struct inode *inode)1367{1368 inode->i_op = &ext2_file_inode_operations;1369 inode->i_fop = &ext2_file_operations;1370 if (IS_DAX(inode))1371 inode->i_mapping->a_ops = &ext2_dax_aops;1372 else1373 inode->i_mapping->a_ops = &ext2_aops;1374}1375 1376struct inode *ext2_iget (struct super_block *sb, unsigned long ino)1377{1378 struct ext2_inode_info *ei;1379 struct buffer_head * bh = NULL;1380 struct ext2_inode *raw_inode;1381 struct inode *inode;1382 long ret = -EIO;1383 int n;1384 uid_t i_uid;1385 gid_t i_gid;1386 1387 inode = iget_locked(sb, ino);1388 if (!inode)1389 return ERR_PTR(-ENOMEM);1390 if (!(inode->i_state & I_NEW))1391 return inode;1392 1393 ei = EXT2_I(inode);1394 ei->i_block_alloc_info = NULL;1395 1396 raw_inode = ext2_get_inode(inode->i_sb, ino, &bh);1397 if (IS_ERR(raw_inode)) {1398 ret = PTR_ERR(raw_inode);1399 goto bad_inode;1400 }1401 1402 inode->i_mode = le16_to_cpu(raw_inode->i_mode);1403 i_uid = (uid_t)le16_to_cpu(raw_inode->i_uid_low);1404 i_gid = (gid_t)le16_to_cpu(raw_inode->i_gid_low);1405 if (!(test_opt (inode->i_sb, NO_UID32))) {1406 i_uid |= le16_to_cpu(raw_inode->i_uid_high) << 16;1407 i_gid |= le16_to_cpu(raw_inode->i_gid_high) << 16;1408 }1409 i_uid_write(inode, i_uid);1410 i_gid_write(inode, i_gid);1411 set_nlink(inode, le16_to_cpu(raw_inode->i_links_count));1412 inode->i_size = le32_to_cpu(raw_inode->i_size);1413 inode_set_atime(inode, (signed)le32_to_cpu(raw_inode->i_atime), 0);1414 inode_set_ctime(inode, (signed)le32_to_cpu(raw_inode->i_ctime), 0);1415 inode_set_mtime(inode, (signed)le32_to_cpu(raw_inode->i_mtime), 0);1416 ei->i_dtime = le32_to_cpu(raw_inode->i_dtime);1417 /* We now have enough fields to check if the inode was active or not.1418 * This is needed because nfsd might try to access dead inodes1419 * the test is that same one that e2fsck uses1420 * NeilBrown 1999oct151421 */1422 if (inode->i_nlink == 0 && (inode->i_mode == 0 || ei->i_dtime)) {1423 /* this inode is deleted */1424 ret = -ESTALE;1425 goto bad_inode;1426 }1427 inode->i_blocks = le32_to_cpu(raw_inode->i_blocks);1428 ei->i_flags = le32_to_cpu(raw_inode->i_flags);1429 ext2_set_inode_flags(inode);1430 ei->i_faddr = le32_to_cpu(raw_inode->i_faddr);1431 ei->i_frag_no = raw_inode->i_frag;1432 ei->i_frag_size = raw_inode->i_fsize;1433 ei->i_file_acl = le32_to_cpu(raw_inode->i_file_acl);1434 ei->i_dir_acl = 0;1435 1436 if (ei->i_file_acl &&1437 !ext2_data_block_valid(EXT2_SB(sb), ei->i_file_acl, 1)) {1438 ext2_error(sb, "ext2_iget", "bad extended attribute block %u",1439 ei->i_file_acl);1440 ret = -EFSCORRUPTED;1441 goto bad_inode;1442 }1443 1444 if (S_ISREG(inode->i_mode))1445 inode->i_size |= ((__u64)le32_to_cpu(raw_inode->i_size_high)) << 32;1446 else1447 ei->i_dir_acl = le32_to_cpu(raw_inode->i_dir_acl);1448 if (i_size_read(inode) < 0) {1449 ret = -EFSCORRUPTED;1450 goto bad_inode;1451 }1452 ei->i_dtime = 0;1453 inode->i_generation = le32_to_cpu(raw_inode->i_generation);1454 ei->i_state = 0;1455 ei->i_block_group = (ino - 1) / EXT2_INODES_PER_GROUP(inode->i_sb);1456 ei->i_dir_start_lookup = 0;1457 1458 /*1459 * NOTE! The in-memory inode i_data array is in little-endian order1460 * even on big-endian machines: we do NOT byteswap the block numbers!1461 */1462 for (n = 0; n < EXT2_N_BLOCKS; n++)1463 ei->i_data[n] = raw_inode->i_block[n];1464 1465 if (S_ISREG(inode->i_mode)) {1466 ext2_set_file_ops(inode);1467 } else if (S_ISDIR(inode->i_mode)) {1468 inode->i_op = &ext2_dir_inode_operations;1469 inode->i_fop = &ext2_dir_operations;1470 inode->i_mapping->a_ops = &ext2_aops;1471 } else if (S_ISLNK(inode->i_mode)) {1472 if (ext2_inode_is_fast_symlink(inode)) {1473 inode->i_link = (char *)ei->i_data;1474 inode->i_op = &ext2_fast_symlink_inode_operations;1475 nd_terminate_link(ei->i_data, inode->i_size,1476 sizeof(ei->i_data) - 1);1477 } else {1478 inode->i_op = &ext2_symlink_inode_operations;1479 inode_nohighmem(inode);1480 inode->i_mapping->a_ops = &ext2_aops;1481 }1482 } else {1483 inode->i_op = &ext2_special_inode_operations;1484 if (raw_inode->i_block[0])1485 init_special_inode(inode, inode->i_mode,1486 old_decode_dev(le32_to_cpu(raw_inode->i_block[0])));1487 else 1488 init_special_inode(inode, inode->i_mode,1489 new_decode_dev(le32_to_cpu(raw_inode->i_block[1])));1490 }1491 brelse (bh);1492 unlock_new_inode(inode);1493 return inode;1494 1495bad_inode:1496 brelse(bh);1497 iget_failed(inode);1498 return ERR_PTR(ret);1499}1500 1501static int __ext2_write_inode(struct inode *inode, int do_sync)1502{1503 struct ext2_inode_info *ei = EXT2_I(inode);1504 struct super_block *sb = inode->i_sb;1505 ino_t ino = inode->i_ino;1506 uid_t uid = i_uid_read(inode);1507 gid_t gid = i_gid_read(inode);1508 struct buffer_head * bh;1509 struct ext2_inode * raw_inode = ext2_get_inode(sb, ino, &bh);1510 int n;1511 int err = 0;1512 1513 if (IS_ERR(raw_inode))1514 return -EIO;1515 1516 /* For fields not tracking in the in-memory inode,1517 * initialise them to zero for new inodes. */1518 if (ei->i_state & EXT2_STATE_NEW)1519 memset(raw_inode, 0, EXT2_SB(sb)->s_inode_size);1520 1521 raw_inode->i_mode = cpu_to_le16(inode->i_mode);1522 if (!(test_opt(sb, NO_UID32))) {1523 raw_inode->i_uid_low = cpu_to_le16(low_16_bits(uid));1524 raw_inode->i_gid_low = cpu_to_le16(low_16_bits(gid));1525/*1526 * Fix up interoperability with old kernels. Otherwise, old inodes get1527 * re-used with the upper 16 bits of the uid/gid intact1528 */1529 if (!ei->i_dtime) {1530 raw_inode->i_uid_high = cpu_to_le16(high_16_bits(uid));1531 raw_inode->i_gid_high = cpu_to_le16(high_16_bits(gid));1532 } else {1533 raw_inode->i_uid_high = 0;1534 raw_inode->i_gid_high = 0;1535 }1536 } else {1537 raw_inode->i_uid_low = cpu_to_le16(fs_high2lowuid(uid));1538 raw_inode->i_gid_low = cpu_to_le16(fs_high2lowgid(gid));1539 raw_inode->i_uid_high = 0;1540 raw_inode->i_gid_high = 0;1541 }1542 raw_inode->i_links_count = cpu_to_le16(inode->i_nlink);1543 raw_inode->i_size = cpu_to_le32(inode->i_size);1544 raw_inode->i_atime = cpu_to_le32(inode_get_atime_sec(inode));1545 raw_inode->i_ctime = cpu_to_le32(inode_get_ctime_sec(inode));1546 raw_inode->i_mtime = cpu_to_le32(inode_get_mtime_sec(inode));1547 1548 raw_inode->i_blocks = cpu_to_le32(inode->i_blocks);1549 raw_inode->i_dtime = cpu_to_le32(ei->i_dtime);1550 raw_inode->i_flags = cpu_to_le32(ei->i_flags);1551 raw_inode->i_faddr = cpu_to_le32(ei->i_faddr);1552 raw_inode->i_frag = ei->i_frag_no;1553 raw_inode->i_fsize = ei->i_frag_size;1554 raw_inode->i_file_acl = cpu_to_le32(ei->i_file_acl);1555 if (!S_ISREG(inode->i_mode))1556 raw_inode->i_dir_acl = cpu_to_le32(ei->i_dir_acl);1557 else {1558 raw_inode->i_size_high = cpu_to_le32(inode->i_size >> 32);1559 if (inode->i_size > 0x7fffffffULL) {1560 if (!EXT2_HAS_RO_COMPAT_FEATURE(sb,1561 EXT2_FEATURE_RO_COMPAT_LARGE_FILE) ||1562 EXT2_SB(sb)->s_es->s_rev_level ==1563 cpu_to_le32(EXT2_GOOD_OLD_REV)) {1564 /* If this is the first large file1565 * created, add a flag to the superblock.1566 */1567 spin_lock(&EXT2_SB(sb)->s_lock);1568 ext2_update_dynamic_rev(sb);1569 EXT2_SET_RO_COMPAT_FEATURE(sb,1570 EXT2_FEATURE_RO_COMPAT_LARGE_FILE);1571 spin_unlock(&EXT2_SB(sb)->s_lock);1572 ext2_sync_super(sb, EXT2_SB(sb)->s_es, 1);1573 }1574 }1575 }1576 1577 raw_inode->i_generation = cpu_to_le32(inode->i_generation);1578 if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) {1579 if (old_valid_dev(inode->i_rdev)) {1580 raw_inode->i_block[0] =1581 cpu_to_le32(old_encode_dev(inode->i_rdev));1582 raw_inode->i_block[1] = 0;1583 } else {1584 raw_inode->i_block[0] = 0;1585 raw_inode->i_block[1] =1586 cpu_to_le32(new_encode_dev(inode->i_rdev));1587 raw_inode->i_block[2] = 0;1588 }1589 } else for (n = 0; n < EXT2_N_BLOCKS; n++)1590 raw_inode->i_block[n] = ei->i_data[n];1591 mark_buffer_dirty(bh);1592 if (do_sync) {1593 sync_dirty_buffer(bh);1594 if (buffer_req(bh) && !buffer_uptodate(bh)) {1595 printk ("IO error syncing ext2 inode [%s:%08lx]\n",1596 sb->s_id, (unsigned long) ino);1597 err = -EIO;1598 }1599 }1600 ei->i_state &= ~EXT2_STATE_NEW;1601 brelse (bh);1602 return err;1603}1604 1605int ext2_write_inode(struct inode *inode, struct writeback_control *wbc)1606{1607 return __ext2_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL);1608}1609 1610int ext2_getattr(struct mnt_idmap *idmap, const struct path *path,1611 struct kstat *stat, u32 request_mask, unsigned int query_flags)1612{1613 struct inode *inode = d_inode(path->dentry);1614 struct ext2_inode_info *ei = EXT2_I(inode);1615 unsigned int flags;1616 1617 flags = ei->i_flags & EXT2_FL_USER_VISIBLE;1618 if (flags & EXT2_APPEND_FL)1619 stat->attributes |= STATX_ATTR_APPEND;1620 if (flags & EXT2_COMPR_FL)1621 stat->attributes |= STATX_ATTR_COMPRESSED;1622 if (flags & EXT2_IMMUTABLE_FL)1623 stat->attributes |= STATX_ATTR_IMMUTABLE;1624 if (flags & EXT2_NODUMP_FL)1625 stat->attributes |= STATX_ATTR_NODUMP;1626 stat->attributes_mask |= (STATX_ATTR_APPEND |1627 STATX_ATTR_COMPRESSED |1628 STATX_ATTR_ENCRYPTED |1629 STATX_ATTR_IMMUTABLE |1630 STATX_ATTR_NODUMP);1631 1632 generic_fillattr(&nop_mnt_idmap, request_mask, inode, stat);1633 return 0;1634}1635 1636int ext2_setattr(struct mnt_idmap *idmap, struct dentry *dentry,1637 struct iattr *iattr)1638{1639 struct inode *inode = d_inode(dentry);1640 int error;1641 1642 error = setattr_prepare(&nop_mnt_idmap, dentry, iattr);1643 if (error)1644 return error;1645 1646 if (is_quota_modification(&nop_mnt_idmap, inode, iattr)) {1647 error = dquot_initialize(inode);1648 if (error)1649 return error;1650 }1651 if (i_uid_needs_update(&nop_mnt_idmap, iattr, inode) ||1652 i_gid_needs_update(&nop_mnt_idmap, iattr, inode)) {1653 error = dquot_transfer(&nop_mnt_idmap, inode, iattr);1654 if (error)1655 return error;1656 }1657 if (iattr->ia_valid & ATTR_SIZE && iattr->ia_size != inode->i_size) {1658 error = ext2_setsize(inode, iattr->ia_size);1659 if (error)1660 return error;1661 }1662 setattr_copy(&nop_mnt_idmap, inode, iattr);1663 if (iattr->ia_valid & ATTR_MODE)1664 error = posix_acl_chmod(&nop_mnt_idmap, dentry, inode->i_mode);1665 mark_inode_dirty(inode);1666 1667 return error;1668}1669