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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * linux/fs/ext2/inode.c
4 *
5 * Copyright (C) 1992, 1993, 1994, 1995
6 * Remy Card ([email protected])
7 * Laboratoire MASI - Institut Blaise Pascal
8 * Universite Pierre et Marie Curie (Paris VI)
9 *
10 * from
11 *
12 * linux/fs/minix/inode.c
13 *
14 * Copyright (C) 1991, 1992 Linus Torvalds
15 *
16 * Goal-directed block allocation by Stephen Tweedie
17 * ([email protected]), 1993, 1998
18 * Big-endian to little-endian byte-swapping/bitmaps by
19 * David S. Miller ([email protected]), 1995
20 * 64-bit file support on 64-bit platforms by Jakub Jelinek
21 * ([email protected])
22 *
23 * Assorted race fixes, rewrite of ext2_get_block() by Al Viro, 2000
24 */
25
26#include <linux/time.h>
27#include <linux/highuid.h>
28#include <linux/pagemap.h>
29#include <linux/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/*
43 * Test whether an inode is a fast symlink.
44 */
45static inline int ext2_inode_is_fast_symlink(struct inode *inode)
46{
47 int ea_blocks = EXT2_I(inode)->i_file_acl ?
48 (inode->i_sb->s_blocksize >> 9) : 0;
49
50 return (S_ISLNK(inode->i_mode) &&
51 inode->i_blocks - ea_blocks == 0);
52}
53
54static void ext2_truncate_blocks(struct inode *inode, loff_t offset);
55
56void ext2_write_failed(struct address_space *mapping, loff_t to)
57{
58 struct inode *inode = mapping->host;
59
60 if (to > inode->i_size) {
61 truncate_pagecache(inode, inode->i_size);
62 ext2_truncate_blocks(inode, inode->i_size);
63 }
64}
65
66/*
67 * Called at the last iput() if i_nlink is zero.
68 */
69void ext2_evict_inode(struct inode * inode)
70{
71 struct ext2_block_alloc_info *rsv;
72 int want_delete = 0;
73
74 if (!inode->i_nlink && !is_bad_inode(inode)) {
75 want_delete = 1;
76 dquot_initialize(inode);
77 } else {
78 dquot_drop(inode);
79 }
80
81 truncate_inode_pages_final(&inode->i_data);
82
83 if (want_delete) {
84 sb_start_intwrite(inode->i_sb);
85 /* set dtime */
86 EXT2_I(inode)->i_dtime = ktime_get_real_seconds();
87 mark_inode_dirty(inode);
88 sync_inode_metadata(inode, inode_needs_sync(inode));
89 /* truncate to 0 */
90 inode->i_size = 0;
91 if (inode->i_blocks)
92 ext2_truncate_blocks(inode, 0);
93 ext2_xattr_delete_inode(inode);
94 } else {
95 mmb_sync(&EXT2_I(inode)->i_metadata_bhs);
96 }
97 mmb_invalidate(&EXT2_I(inode)->i_metadata_bhs);
98 clear_inode(inode);
99
100 ext2_discard_reservation(inode);
101 rsv = EXT2_I(inode)->i_block_alloc_info;
102 EXT2_I(inode)->i_block_alloc_info = NULL;
103 if (unlikely(rsv))
104 kfree(rsv);
105
106 if (want_delete) {
107 ext2_free_inode(inode);
108 sb_end_intwrite(inode->i_sb);
109 }
110}
111
112typedef struct {
113 __le32 *p;
114 __le32 key;
115 struct buffer_head *bh;
116} Indirect;
117
118static inline void add_chain(Indirect *p, struct buffer_head *bh, __le32 *v)
119{
120 p->key = *(p->p = v);
121 p->bh = bh;
122}
123
124static inline int verify_chain(Indirect *from, Indirect *to)
125{
126 while (from <= to && from->key == *from->p)
127 from++;
128 return (from > to);
129}
130
131/**
132 * ext2_block_to_path - parse the block number into array of offsets
133 * @inode: inode in question (we are only interested in its superblock)
134 * @i_block: block number to be parsed
135 * @offsets: array to store the offsets in
136 * @boundary: set this non-zero if the referred-to block is likely to be
137 * followed (on disk) by an indirect block.
138 * To store the locations of file's data ext2 uses a data structure common
139 * for UNIX filesystems - tree of pointers anchored in the inode, with
140 * data blocks at leaves and indirect blocks in intermediate nodes.
141 * This function translates the block number into path in that tree -
142 * return value is the path length and @offsets[n] is the offset of
143 * pointer to (n+1)th node in the nth one. If @block is out of range
144 * (negative or too large) warning is printed and zero returned.
145 *
146 * Note: function doesn't find node addresses, so no IO is needed. All
147 * we need to know is the capacity of indirect blocks (taken from the
148 * inode->i_sb).
149 */
150
151/*
152 * Portability note: the last comparison (check that we fit into triple
153 * indirect block) is spelled differently, because otherwise on an
154 * architecture with 32-bit longs and 8Kb pages we might get into trouble
155 * if our filesystem had 8Kb blocks. We might use long long, but that would
156 * kill us on x86. Oh, well, at least the sign propagation does not matter -
157 * i_block would have to be negative in the very beginning, so we would not
158 * get there at all.
159 */
160
161static int ext2_block_to_path(struct inode *inode,
162 long i_block, int offsets[4], int *boundary)
163{
164 int ptrs = EXT2_ADDR_PER_BLOCK(inode->i_sb);
165 int ptrs_bits = EXT2_ADDR_PER_BLOCK_BITS(inode->i_sb);
166 const long direct_blocks = EXT2_NDIR_BLOCKS,
167 indirect_blocks = ptrs,
168 double_blocks = (1 << (ptrs_bits * 2));
169 int n = 0;
170 int final = 0;
171
172 if (i_block < 0) {
173 ext2_msg(inode->i_sb, KERN_WARNING,
174 "warning: %s: block < 0", __func__);
175 } else if (i_block < direct_blocks) {
176 offsets[n++] = i_block;
177 final = direct_blocks;
178 } else if ( (i_block -= direct_blocks) < indirect_blocks) {
179 offsets[n++] = EXT2_IND_BLOCK;
180 offsets[n++] = i_block;
181 final = ptrs;
182 } else if ((i_block -= indirect_blocks) < double_blocks) {
183 offsets[n++] = EXT2_DIND_BLOCK;
184 offsets[n++] = i_block >> ptrs_bits;
185 offsets[n++] = i_block & (ptrs - 1);
186 final = ptrs;
187 } else if (((i_block -= double_blocks) >> (ptrs_bits * 2)) < ptrs) {
188 offsets[n++] = EXT2_TIND_BLOCK;
189 offsets[n++] = i_block >> (ptrs_bits * 2);
190 offsets[n++] = (i_block >> ptrs_bits) & (ptrs - 1);
191 offsets[n++] = i_block & (ptrs - 1);
192 final = ptrs;
193 } else {
194 ext2_msg(inode->i_sb, KERN_WARNING,
195 "warning: %s: block is too big", __func__);
196 }
197 if (boundary)
198 *boundary = final - 1 - (i_block & (ptrs - 1));
199
200 return n;
201}
202
203/**
204 * ext2_get_branch - read the chain of indirect blocks leading to data
205 * @inode: inode in question
206 * @depth: depth of the chain (1 - direct pointer, etc.)
207 * @offsets: offsets of pointers in inode/indirect blocks
208 * @chain: place to store the result
209 * @err: here we store the error value
210 *
211 * Function fills the array of triples <key, p, bh> and returns %NULL
212 * if everything went OK or the pointer to the last filled triple
213 * (incomplete one) otherwise. Upon the return chain[i].key contains
214 * the number of (i+1)-th block in the chain (as it is stored in memory,
215 * i.e. little-endian 32-bit), chain[i].p contains the address of that
216 * number (it points into struct inode for i==0 and into the bh->b_data
217 * for i>0) and chain[i].bh points to the buffer_head of i-th indirect
218 * block for i>0 and NULL for i==0. In other words, it holds the block
219 * numbers of the chain, addresses they were taken from (and where we can
220 * verify that chain did not change) and buffer_heads hosting these
221 * numbers.
222 *
223 * Function stops when it stumbles upon zero pointer (absent block)
224 * (pointer to last triple returned, *@err == 0)
225 * or when it gets an IO error reading an indirect block
226 * (ditto, *@err == -EIO)
227 * or when it notices that chain had been changed while it was reading
228 * (ditto, *@err == -EAGAIN)
229 * or when it reads all @depth-1 indirect blocks successfully and finds
230 * the whole chain, all way to the data (returns %NULL, *err == 0).
231 */
232static Indirect *ext2_get_branch(struct inode *inode,
233 int depth,
234 int *offsets,
235 Indirect chain[4],
236 int *err)
237{
238 struct super_block *sb = inode->i_sb;
239 Indirect *p = chain;
240 struct buffer_head *bh;
241
242 *err = 0;
243 /* i_data is not going away, no lock needed */
244 add_chain (chain, NULL, EXT2_I(inode)->i_data + *offsets);
245 if (!p->key)
246 goto no_block;
247 while (--depth) {
248 bh = sb_bread(sb, le32_to_cpu(p->key));
249 if (!bh)
250 goto failure;
251 read_lock(&EXT2_I(inode)->i_meta_lock);
252 if (!verify_chain(chain, p))
253 goto changed;
254 add_chain(++p, bh, (__le32*)bh->b_data + *++offsets);
255 read_unlock(&EXT2_I(inode)->i_meta_lock);
256 if (!p->key)
257 goto no_block;
258 }
259 return NULL;
260
261changed:
262 read_unlock(&EXT2_I(inode)->i_meta_lock);
263 brelse(bh);
264 *err = -EAGAIN;
265 goto no_block;
266failure:
267 *err = -EIO;
268no_block:
269 return p;
270}
271
272/**
273 * ext2_find_near - find a place for allocation with sufficient locality
274 * @inode: owner
275 * @ind: descriptor of indirect block.
276 *
277 * This function returns the preferred place for block allocation.
278 * It is used when heuristic for sequential allocation fails.
279 * Rules are:
280 * + if there is a block to the left of our position - allocate near it.
281 * + if pointer will live in indirect block - allocate near that block.
282 * + if pointer will live in inode - allocate in the same cylinder group.
283 *
284 * In the latter case we colour the starting block by the callers PID to
285 * prevent it from clashing with concurrent allocations for a different inode
286 * in the same block group. The PID is used here so that functionally related
287 * files will be close-by on-disk.
288 *
289 * Caller must make sure that @ind is valid and will stay that way.
290 */
291
292static ext2_fsblk_t ext2_find_near(struct inode *inode, Indirect *ind)
293{
294 struct ext2_inode_info *ei = EXT2_I(inode);
295 __le32 *start = ind->bh ? (__le32 *) ind->bh->b_data : ei->i_data;
296 __le32 *p;
297 ext2_fsblk_t bg_start;
298 ext2_fsblk_t colour;
299
300 /* Try to find previous block */
301 for (p = ind->p - 1; p >= start; p--)
302 if (*p)
303 return le32_to_cpu(*p);
304
305 /* No such thing, so let's try location of indirect block */
306 if (ind->bh)
307 return ind->bh->b_blocknr;
308
309 /*
310 * It is going to be referred from inode itself? OK, just put it into
311 * the same cylinder group then.
312 */
313 bg_start = ext2_group_first_block_no(inode->i_sb, ei->i_block_group);
314 colour = (current->pid % 16) *
315 (EXT2_BLOCKS_PER_GROUP(inode->i_sb) / 16);
316 return bg_start + colour;
317}
318
319/**
320 * ext2_find_goal - find a preferred place for allocation.
321 * @inode: owner
322 * @block: block we want
323 * @partial: pointer to the last triple within a chain
324 *
325 * Returns preferred place for a block (the goal).
326 */
327
328static inline ext2_fsblk_t ext2_find_goal(struct inode *inode, long block,
329 Indirect *partial)
330 __must_hold(&EXT2_I(inode)->truncate_mutex)
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 number of direct blocks to allocate.
358 */
359static int
360ext2_blks_to_allocate(Indirect * branch, int k, unsigned long blks,
361 int blocks_to_boundary)
362{
363 unsigned long count = 0;
364
365 /*
366 * Simple case, [t,d]Indirect block(s) has not allocated yet
367 * then it's clear blocks on that path have not allocated
368 */
369 if (k > 0) {
370 /* right now don't hanel cross boundary allocation */
371 if (blks < blocks_to_boundary + 1)
372 count += blks;
373 else
374 count += blocks_to_boundary + 1;
375 return count;
376 }
377
378 count++;
379 while (count < blks && count <= blocks_to_boundary
380 && le32_to_cpu(*(branch[0].p + count)) == 0) {
381 count++;
382 }
383 return count;
384}
385
386/**
387 * ext2_alloc_blocks: Allocate multiple blocks needed for a branch.
388 * @inode: Owner.
389 * @goal: Preferred place for allocation.
390 * @indirect_blks: The number of blocks needed to allocate for indirect blocks.
391 * @blks: The number of blocks need to allocate for direct blocks.
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 * @err: Error pointer.
395 *
396 * Return: Number of blocks allocated.
397 */
398static int ext2_alloc_blocks(struct inode *inode,
399 ext2_fsblk_t goal, int indirect_blks, int blks,
400 ext2_fsblk_t new_blocks[4], int *err)
401 __must_hold(&EXT2_I(inode)->truncate_mutex)
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 for
413 * the indirect blocks(if not allocated yet), and at least
414 * the first direct block of this branch. That's the
415 * 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: owner
455 * @indirect_blks: depth of the chain (number of blocks to allocate)
456 * @blks: number of allocated direct blocks
457 * @goal: preferred place for allocation
458 * @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 the
464 * inode. It stores the information about that chain in the branch[], in
465 * the same format as ext2_get_branch() would do. We are calling it after
466 * we had read the existing part of chain and partial points to the last
467 * triple of that (one with zero ->key). Upon the exit we have the same
468 * picture as after the successful ext2_get_block(), except that in one
469 * place chain is disconnected - *branch->p is still zero (we did not
470 * set the last link), but branch->key contains the number that should
471 * be placed into *branch->p to fill that gap.
472 *
473 * If allocation fails we free all blocks we've allocated (and forget
474 * their buffer_heads) and return the error value the from failed
475 * ext2_alloc_block() (normally -ENOSPC). Otherwise we set the chain
476 * 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 __must_hold(&EXT2_I(inode)->truncate_mutex)
483{
484 int blocksize = inode->i_sb->s_blocksize;
485 int i, n = 0;
486 int err = 0;
487 struct buffer_head *bh;
488 int num;
489 ext2_fsblk_t new_blocks[4];
490 ext2_fsblk_t current_block;
491
492 num = ext2_alloc_blocks(inode, goal, indirect_blks,
493 *blks, new_blocks, &err);
494 if (err)
495 return err;
496
497 branch[0].key = cpu_to_le32(new_blocks[0]);
498 /*
499 * metadata blocks and data blocks are allocated.
500 */
501 for (n = 1; n <= indirect_blks; n++) {
502 /*
503 * Get buffer_head for parent block, zero it out
504 * and set the pointer to new one, then send
505 * parent to disk.
506 */
507 bh = sb_getblk(inode->i_sb, new_blocks[n-1]);
508 if (unlikely(!bh)) {
509 err = -ENOMEM;
510 goto failed;
511 }
512 branch[n].bh = bh;
513 lock_buffer(bh);
514 memset(bh->b_data, 0, blocksize);
515 branch[n].p = (__le32 *) bh->b_data + offsets[n];
516 branch[n].key = cpu_to_le32(new_blocks[n]);
517 *branch[n].p = branch[n].key;
518 if ( n == indirect_blks) {
519 current_block = new_blocks[n];
520 /*
521 * End of chain, update the last new metablock of
522 * the chain to point to the new allocated
523 * data blocks numbers
524 */
525 for (i=1; i < num; i++)
526 *(branch[n].p + i) = cpu_to_le32(++current_block);
527 }
528 set_buffer_uptodate(bh);
529 unlock_buffer(bh);
530 mmb_mark_buffer_dirty(bh, &EXT2_I(inode)->i_metadata_bhs);
531 /* We used to sync bh here if IS_SYNC(inode).
532 * But we now rely upon generic_write_sync()
533 * and b_inode_buffers. But not for directories.
534 */
535 if (S_ISDIR(inode->i_mode) && IS_DIRSYNC(inode))
536 sync_dirty_buffer(bh);
537 }
538 *blks = num;
539 return err;
540
541failed:
542 for (i = 1; i < n; i++)
543 bforget(branch[i].bh);
544 for (i = 0; i < indirect_blks; i++)
545 ext2_free_blocks(inode, new_blocks[i], 1);
546 ext2_free_blocks(inode, new_blocks[i], num);
547 return err;
548}
549
550/**
551 * ext2_splice_branch - splice the allocated branch onto inode.
552 * @inode: owner
553 * @block: (logical) number of block we are adding
554 * @where: location of missing link
555 * @num: number of indirect blocks we are adding
556 * @blks: number of direct blocks we are adding
557 *
558 * This function fills the missing link and does all housekeeping needed in
559 * inode (->i_blocks, etc.). In case of success we end up with the full
560 * chain to new block and return 0.
561 */
562static void ext2_splice_branch(struct inode *inode,
563 long block, Indirect *where, int num, int blks)
564 __must_hold(&EXT2_I(inode)->truncate_mutex)
565{
566 int i;
567 struct ext2_block_alloc_info *block_i;
568 ext2_fsblk_t current_block;
569
570 block_i = EXT2_I(inode)->i_block_alloc_info;
571
572 /* XXX LOCKING probably should have i_meta_lock ?*/
573 /* That's it */
574
575 *where->p = where->key;
576
577 /*
578 * Update the host buffer_head or inode to point to more just allocated
579 * direct blocks blocks
580 */
581 if (num == 0 && blks > 1) {
582 current_block = le32_to_cpu(where->key) + 1;
583 for (i = 1; i < blks; i++)
584 *(where->p + i ) = cpu_to_le32(current_block++);
585 }
586
587 /*
588 * update the most recently allocated logical & physical block
589 * in i_block_alloc_info, to assist find the proper goal block for next
590 * allocation
591 */
592 if (block_i) {
593 block_i->last_alloc_logical_block = block + blks - 1;
594 block_i->last_alloc_physical_block =
595 le32_to_cpu(where[num].key) + blks - 1;
596 }
597
598 /* We are done with atomic stuff, now do the rest of housekeeping */
599
600 /* had we spliced it onto indirect block? */
601 if (where->bh)
602 mmb_mark_buffer_dirty(where->bh, &EXT2_I(inode)->i_metadata_bhs);
603
604 inode_set_ctime_current(inode);
605 mark_inode_dirty(inode);
606}
607
608/*
609 * Allocation strategy is simple: if we have to allocate something, we will
610 * have to go the whole way to leaf. So let's do it before attaching anything
611 * to tree, set linkage between the newborn blocks, write them if sync is
612 * required, recheck the path, free and repeat if check fails, otherwise
613 * set the last missing link (that will protect us from any truncate-generated
614 * removals - all blocks on the path are immune now) and possibly force the
615 * write on the parent block.
616 * That has a nice additional property: no special recovery from the failed
617 * allocations is needed - we simply release blocks and do not touch anything
618 * reachable from inode.
619 *
620 * `handle' can be NULL if create == 0.
621 *
622 * return > 0, # of blocks mapped or allocated.
623 * return = 0, if plain lookup failed.
624 * return < 0, error case.
625 */
626static int ext2_get_blocks(struct inode *inode,
627 sector_t iblock, unsigned long maxblocks,
628 u32 *bno, bool *new, bool *boundary,
629 int create)
630{
631 int err;
632 int offsets[4];
633 Indirect chain[4];
634 Indirect *partial;
635 ext2_fsblk_t goal;
636 int indirect_blks;
637 int blocks_to_boundary = 0;
638 int depth;
639 struct ext2_inode_info *ei = EXT2_I(inode);
640 int count = 0;
641 ext2_fsblk_t first_block = 0;
642
643 if (WARN_ON_ONCE(maxblocks == 0))
644 return -EINVAL;
645
646 depth = ext2_block_to_path(inode,iblock,offsets,&blocks_to_boundary);
647
648 if (depth == 0)
649 return -EIO;
650
651 partial = ext2_get_branch(inode, depth, offsets, chain, &err);
652 /* Simplest case - block found, no allocation needed */
653 if (!partial) {
654 first_block = le32_to_cpu(chain[depth - 1].key);
655 count++;
656 /*map more blocks*/
657 while (count < maxblocks && count <= blocks_to_boundary) {
658 ext2_fsblk_t blk;
659
660 if (!verify_chain(chain, chain + depth - 1)) {
661 /*
662 * Indirect block might be removed by
663 * truncate while we were reading it.
664 * Handling of that case: forget what we've
665 * got now, go to reread.
666 */
667 err = -EAGAIN;
668 count = 0;
669 partial = chain + depth - 1;
670 break;
671 }
672 blk = le32_to_cpu(*(chain[depth-1].p + count));
673 if (blk == first_block + count)
674 count++;
675 else
676 break;
677 }
678 if (err != -EAGAIN)
679 goto got_it;
680 }
681
682 /* Next simple case - plain lookup or failed read of indirect block */
683 if (!create || err == -EIO)
684 goto cleanup;
685
686 mutex_lock(&ei->truncate_mutex);
687 /*
688 * If the indirect block is missing while we are reading
689 * the chain(ext2_get_branch() returns -EAGAIN err), or
690 * if the chain has been changed after we grab the semaphore,
691 * (either because another process truncated this branch, or
692 * another get_block allocated this branch) re-grab the chain to see if
693 * the request block has been allocated or not.
694 *
695 * Since we already block the truncate/other get_block
696 * at this point, we will have the current copy of the chain when we
697 * splice the branch into the tree.
698 */
699 if (err == -EAGAIN || !verify_chain(chain, partial)) {
700 while (partial > chain) {
701 brelse(partial->bh);
702 partial--;
703 }
704 partial = ext2_get_branch(inode, depth, offsets, chain, &err);
705 if (!partial) {
706 count++;
707 mutex_unlock(&ei->truncate_mutex);
708 goto got_it;
709 }
710
711 if (err) {
712 mutex_unlock(&ei->truncate_mutex);
713 goto cleanup;
714 }
715 }
716
717 /*
718 * Okay, we need to do block allocation. Lazily initialize the block
719 * allocation info here if necessary
720 */
721 if (S_ISREG(inode->i_mode) && (!ei->i_block_alloc_info))
722 ext2_init_block_alloc_info(inode);
723
724 goal = ext2_find_goal(inode, iblock, partial);
725
726 /* the number of blocks need to allocate for [d,t]indirect blocks */
727 indirect_blks = (chain + depth) - partial - 1;
728 /*
729 * Next look up the indirect map to count the total number of
730 * direct blocks to allocate for this branch.
731 */
732 count = ext2_blks_to_allocate(partial, indirect_blks,
733 maxblocks, blocks_to_boundary);
734 /*
735 * XXX ???? Block out ext2_truncate while we alter the tree
736 */
737 err = ext2_alloc_branch(inode, indirect_blks, &count, goal,
738 offsets + (partial - chain), partial);
739
740 if (err) {
741 mutex_unlock(&ei->truncate_mutex);
742 goto cleanup;
743 }
744
745 *new = true;
746
747 ext2_splice_branch(inode, iblock, partial, indirect_blks, count);
748 mutex_unlock(&ei->truncate_mutex);
749got_it:
750 if (count > blocks_to_boundary)
751 *boundary = true;
752 err = count;
753 /* Clean up and exit */
754 partial = chain + depth - 1; /* the whole chain */
755cleanup:
756 while (partial > chain) {
757 brelse(partial->bh);
758 partial--;
759 }
760 if (err > 0)
761 *bno = le32_to_cpu(chain[depth-1].key);
762 return err;
763}
764
765int ext2_get_block(struct inode *inode, sector_t iblock,
766 struct buffer_head *bh_result, int create)
767{
768 unsigned max_blocks = bh_result->b_size >> inode->i_blkbits;
769 bool new = false, boundary = false;
770 u32 bno;
771 int ret;
772
773 ret = ext2_get_blocks(inode, iblock, max_blocks, &bno, &new, &boundary,
774 create);
775 if (ret <= 0)
776 return ret;
777
778 map_bh(bh_result, inode->i_sb, bno);
779 bh_result->b_size = (ret << inode->i_blkbits);
780 if (new)
781 set_buffer_new(bh_result);
782 if (boundary)
783 set_buffer_boundary(bh_result);
784 return 0;
785
786}
787
788static int ext2_iomap_begin(struct inode *inode, loff_t offset, loff_t length,
789 unsigned flags, struct iomap *iomap, struct iomap *srcmap)
790{
791 unsigned int blkbits = inode->i_blkbits;
792 unsigned long first_block = offset >> blkbits;
793 unsigned long max_blocks = (length + (1 << blkbits) - 1) >> blkbits;
794 bool new = false, boundary = false;
795 u32 bno;
796 int ret;
797 bool create = flags & IOMAP_WRITE;
798
799 /*
800 * For writes that could fill holes inside i_size on a
801 * DIO_SKIP_HOLES filesystem we forbid block creations: only
802 * overwrites are permitted.
803 */
804 if ((flags & IOMAP_DIRECT) &&
805 (first_block << blkbits) < i_size_read(inode))
806 create = 0;
807
808 /*
809 * Writes that span EOF might trigger an IO size update on completion,
810 * so consider them to be dirty for the purposes of O_DSYNC even if
811 * there is no other metadata changes pending or have been made here.
812 */
813 if ((flags & IOMAP_WRITE) && offset + length > i_size_read(inode))
814 iomap->flags |= IOMAP_F_DIRTY;
815
816 ret = ext2_get_blocks(inode, first_block, max_blocks,
817 &bno, &new, &boundary, create);
818 if (ret < 0)
819 return ret;
820
821 iomap->flags = 0;
822 iomap->offset = (u64)first_block << blkbits;
823 iomap->bdev = inode->i_sb->s_bdev;
824
825 if (ret == 0) {
826 /*
827 * Switch to buffered-io for writing to holes in a non-extent
828 * based filesystem to avoid stale data exposure problem.
829 */
830 if (!create && (flags & IOMAP_WRITE) && (flags & IOMAP_DIRECT))
831 return -ENOTBLK;
832 iomap->type = IOMAP_HOLE;
833 iomap->addr = IOMAP_NULL_ADDR;
834 iomap->length = 1 << blkbits;
835 } else {
836 iomap->type = IOMAP_MAPPED;
837 iomap->addr = (u64)bno << blkbits;
838 iomap->length = (u64)ret << blkbits;
839 iomap->flags |= IOMAP_F_MERGED;
840 }
841
842 if (new)
843 iomap->flags |= IOMAP_F_NEW;
844 return 0;
845}
846
847static int
848ext2_iomap_end(struct inode *inode, loff_t offset, loff_t length,
849 ssize_t written, unsigned flags, struct iomap *iomap)
850{
851 /*
852 * Switch to buffered-io in case of any error.
853 * Blocks allocated can be used by the buffered-io path.
854 */
855 if ((flags & IOMAP_DIRECT) && (flags & IOMAP_WRITE) && written == 0)
856 return -ENOTBLK;
857
858 if (iomap->type == IOMAP_MAPPED &&
859 written < length &&
860 (flags & IOMAP_WRITE))
861 ext2_write_failed(inode->i_mapping, offset + length);
862 return 0;
863}
864
865static DEFINE_IOMAP_ITER_NEXT_END(ext2_iomap_next, ext2_iomap_begin,
866 ext2_iomap_end);
867
868const struct iomap_ops ext2_iomap_ops = {
869 .iomap_next = ext2_iomap_next,
870};
871
872int ext2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
873 u64 start, u64 len)
874{
875 int ret;
876 loff_t i_size;
877
878 inode_lock(inode);
879 i_size = i_size_read(inode);
880 /*
881 * iomap_fiemap() returns EINVAL for 0 length. Make sure we don't trim
882 * length to 0 but still trim the range as much as possible since
883 * ext2_get_blocks() iterates unmapped space block by block which is
884 * slow.
885 */
886 if (i_size == 0)
887 i_size = 1;
888 len = min_t(u64, len, i_size);
889 ret = iomap_fiemap(inode, fieinfo, start, len, &ext2_iomap_ops);
890 inode_unlock(inode);
891
892 return ret;
893}
894
895static int ext2_read_folio(struct file *file, struct folio *folio)
896{
897 return mpage_read_folio(folio, ext2_get_block);
898}
899
900static void ext2_readahead(struct readahead_control *rac)
901{
902 mpage_readahead(rac, ext2_get_block);
903}
904
905static int
906ext2_write_begin(const struct kiocb *iocb, struct address_space *mapping,
907 loff_t pos, unsigned len, struct folio **foliop, void **fsdata)
908{
909 int ret;
910
911 ret = block_write_begin(mapping, pos, len, foliop, ext2_get_block);
912 if (ret < 0)
913 ext2_write_failed(mapping, pos + len);
914 return ret;
915}
916
917static int ext2_write_end(const struct kiocb *iocb,
918 struct address_space *mapping,
919 loff_t pos, unsigned len, unsigned copied,
920 struct folio *folio, void *fsdata)
921{
922 int ret;
923
924 ret = generic_write_end(iocb, mapping, pos, len, copied, folio, fsdata);
925 if (ret < len)
926 ext2_write_failed(mapping, pos + len);
927 return ret;
928}
929
930static sector_t ext2_bmap(struct address_space *mapping, sector_t block)
931{
932 return generic_block_bmap(mapping,block,ext2_get_block);
933}
934
935static int
936ext2_writepages(struct address_space *mapping, struct writeback_control *wbc)
937{
938 return mpage_writepages(mapping, wbc, ext2_get_block);
939}
940
941
942const struct address_space_operations ext2_aops = {
943 .dirty_folio = block_dirty_folio,
944 .invalidate_folio = block_invalidate_folio,
945 .read_folio = ext2_read_folio,
946 .readahead = ext2_readahead,
947 .write_begin = ext2_write_begin,
948 .write_end = ext2_write_end,
949 .bmap = ext2_bmap,
950 .writepages = ext2_writepages,
951 .migrate_folio = buffer_migrate_folio,
952 .is_partially_uptodate = block_is_partially_uptodate,
953 .error_remove_folio = generic_error_remove_folio,
954};
955
956
957/*
958 * Probably it should be a library function... search for first non-zero word
959 * or memcmp with zero_page, whatever is better for particular architecture.
960 * Linus?
961 */
962static inline int all_zeroes(__le32 *p, __le32 *q)
963{
964 while (p < q)
965 if (*p++)
966 return 0;
967 return 1;
968}
969
970/**
971 * ext2_find_shared - find the indirect blocks for partial truncation.
972 * @inode: inode in question
973 * @depth: depth of the affected branch
974 * @offsets: offsets of pointers in that branch (see ext2_block_to_path)
975 * @chain: place to store the pointers to partial indirect blocks
976 * @top: place to the (detached) top of branch
977 *
978 * This is a helper function used by ext2_truncate().
979 *
980 * When we do truncate() we may have to clean the ends of several indirect
981 * blocks but leave the blocks themselves alive. Block is partially
982 * truncated if some data below the new i_size is referred from it (and
983 * it is on the path to the first completely truncated data block, indeed).
984 * We have to free the top of that path along with everything to the right
985 * of the path. Since no allocation past the truncation point is possible
986 * until ext2_truncate() finishes, we may safely do the latter, but top
987 * of branch may require special attention - pageout below the truncation
988 * point might try to populate it.
989 *
990 * We atomically detach the top of branch from the tree, store the block
991 * number of its root in *@top, pointers to buffer_heads of partially
992 * truncated blocks - in @chain[].bh and pointers to their last elements
993 * that should not be removed - in @chain[].p. Return value is the pointer
994 * to last filled element of @chain.
995 *
996 * The work left to caller to do the actual freeing of subtrees:
997 * a) free the subtree starting from *@top
998 * b) free the subtrees whose roots are stored in
999 * (@chain[i].p+1 .. end of @chain[i].bh->b_data)
1000 * c) free the subtrees growing from the inode past the @chain[0].p
1001 * (no partially truncated stuff there).
1002 */
1003
1004static Indirect *ext2_find_shared(struct inode *inode,
1005 int depth,
1006 int offsets[4],
1007 Indirect chain[4],
1008 __le32 *top)
1009 __must_hold(&EXT2_I(inode)->truncate_mutex)
1010{
1011 Indirect *partial, *p;
1012 int k, err;
1013
1014 *top = 0;
1015 for (k = depth; k > 1 && !offsets[k-1]; k--)
1016 ;
1017 partial = ext2_get_branch(inode, k, offsets, chain, &err);
1018 if (!partial)
1019 partial = chain + k-1;
1020 /*
1021 * If the branch acquired continuation since we've looked at it -
1022 * fine, it should all survive and (new) top doesn't belong to us.
1023 */
1024 write_lock(&EXT2_I(inode)->i_meta_lock);
1025 if (!partial->key && *partial->p) {
1026 write_unlock(&EXT2_I(inode)->i_meta_lock);
1027 goto no_top;
1028 }
1029 for (p=partial; p>chain && all_zeroes((__le32*)p->bh->b_data,p->p); p--)
1030 ;
1031 /*
1032 * OK, we've found the last block that must survive. The rest of our
1033 * branch should be detached before unlocking. However, if that rest
1034 * of branch is all ours and does not grow immediately from the inode
1035 * it's easier to cheat and just decrement partial->p.
1036 */
1037 if (p == chain + k - 1 && p > chain) {
1038 p->p--;
1039 } else {
1040 *top = *p->p;
1041 *p->p = 0;
1042 }
1043 write_unlock(&EXT2_I(inode)->i_meta_lock);
1044
1045 while(partial > p)
1046 {
1047 brelse(partial->bh);
1048 partial--;
1049 }
1050no_top:
1051 return partial;
1052}
1053
1054/**
1055 * ext2_free_data - free a list of data blocks
1056 * @inode: inode we are dealing with
1057 * @p: array of block numbers
1058 * @q: points immediately past the end of array
1059 *
1060 * We are freeing all blocks referred from that array (numbers are
1061 * stored as little-endian 32-bit) and updating @inode->i_blocks
1062 * appropriately.
1063 */
1064static inline void ext2_free_data(struct inode *inode, __le32 *p, __le32 *q)
1065 __must_hold(&EXT2_I(inode)->truncate_mutex)
1066{
1067 ext2_fsblk_t block_to_free = 0, count = 0;
1068 ext2_fsblk_t nr;
1069
1070 for ( ; p < q ; p++) {
1071 nr = le32_to_cpu(*p);
1072 if (nr) {
1073 *p = 0;
1074 /* accumulate blocks to free if they're contiguous */
1075 if (count == 0)
1076 goto free_this;
1077 else if (block_to_free == nr - count)
1078 count++;
1079 else {
1080 ext2_free_blocks (inode, block_to_free, count);
1081 mark_inode_dirty(inode);
1082 free_this:
1083 block_to_free = nr;
1084 count = 1;
1085 }
1086 }
1087 }
1088 if (count > 0) {
1089 ext2_free_blocks (inode, block_to_free, count);
1090 mark_inode_dirty(inode);
1091 }
1092}
1093
1094/**
1095 * ext2_free_branches - free an array of branches
1096 * @inode: inode we are dealing with
1097 * @p: array of block numbers
1098 * @q: pointer immediately past the end of array
1099 * @depth: depth of the branches to free
1100 *
1101 * We are freeing all blocks referred from these branches (numbers are
1102 * stored as little-endian 32-bit) and updating @inode->i_blocks
1103 * appropriately.
1104 */
1105static void ext2_free_branches(struct inode *inode, __le32 *p, __le32 *q, int depth)
1106 __must_hold(&EXT2_I(inode)->truncate_mutex)
1107{
1108 struct buffer_head * bh;
1109 ext2_fsblk_t nr;
1110
1111 if (depth--) {
1112 int addr_per_block = EXT2_ADDR_PER_BLOCK(inode->i_sb);
1113 for ( ; p < q ; p++) {
1114 nr = le32_to_cpu(*p);
1115 if (!nr)
1116 continue;
1117 *p = 0;
1118 bh = sb_bread(inode->i_sb, nr);
1119 /*
1120 * A read failure? Report error and clear slot
1121 * (should be rare).
1122 */
1123 if (!bh) {
1124 ext2_error(inode->i_sb, "ext2_free_branches",
1125 "Read failure, inode=%llu, block=%ld",
1126 inode->i_ino, nr);
1127 continue;
1128 }
1129 ext2_free_branches(inode,
1130 (__le32*)bh->b_data,
1131 (__le32*)bh->b_data + addr_per_block,
1132 depth);
1133 bforget(bh);
1134 ext2_free_blocks(inode, nr, 1);
1135 mark_inode_dirty(inode);
1136 }
1137 } else
1138 ext2_free_data(inode, p, q);
1139}
1140
1141/* mapping->invalidate_lock must be held when calling this function */
1142static void __ext2_truncate_blocks(struct inode *inode, loff_t offset)
1143{
1144 __le32 *i_data = EXT2_I(inode)->i_data;
1145 struct ext2_inode_info *ei = EXT2_I(inode);
1146 int addr_per_block = EXT2_ADDR_PER_BLOCK(inode->i_sb);
1147 int offsets[4];
1148 Indirect chain[4];
1149 Indirect *partial;
1150 __le32 nr = 0;
1151 int n;
1152 long iblock;
1153 unsigned blocksize;
1154 blocksize = inode->i_sb->s_blocksize;
1155 iblock = (offset + blocksize-1) >> EXT2_BLOCK_SIZE_BITS(inode->i_sb);
1156
1157
1158 n = ext2_block_to_path(inode, iblock, offsets, NULL);
1159 if (n == 0)
1160 return;
1161
1162 /*
1163 * From here we block out all ext2_get_block() callers who want to
1164 * modify the block allocation tree.
1165 */
1166 mutex_lock(&ei->truncate_mutex);
1167
1168 if (n == 1) {
1169 ext2_free_data(inode, i_data+offsets[0],
1170 i_data + EXT2_NDIR_BLOCKS);
1171 goto do_indirects;
1172 }
1173
1174 partial = ext2_find_shared(inode, n, offsets, chain, &nr);
1175 /* Kill the top of shared branch (already detached) */
1176 if (nr) {
1177 if (partial == chain)
1178 mark_inode_dirty(inode);
1179 else
1180 mmb_mark_buffer_dirty(partial->bh,
1181 &EXT2_I(inode)->i_metadata_bhs);
1182 ext2_free_branches(inode, &nr, &nr+1, (chain+n-1) - partial);
1183 }
1184 /* Clear the ends of indirect blocks on the shared branch */
1185 while (partial > chain) {
1186 ext2_free_branches(inode,
1187 partial->p + 1,
1188 (__le32*)partial->bh->b_data+addr_per_block,
1189 (chain+n-1) - partial);
1190 mmb_mark_buffer_dirty(partial->bh,
1191 &EXT2_I(inode)->i_metadata_bhs);
1192 brelse (partial->bh);
1193 partial--;
1194 }
1195do_indirects:
1196 /* Kill the remaining (whole) subtrees */
1197 switch (offsets[0]) {
1198 default:
1199 nr = i_data[EXT2_IND_BLOCK];
1200 if (nr) {
1201 i_data[EXT2_IND_BLOCK] = 0;
1202 mark_inode_dirty(inode);
1203 ext2_free_branches(inode, &nr, &nr+1, 1);
1204 }
1205 fallthrough;
1206 case EXT2_IND_BLOCK:
1207 nr = i_data[EXT2_DIND_BLOCK];
1208 if (nr) {
1209 i_data[EXT2_DIND_BLOCK] = 0;
1210 mark_inode_dirty(inode);
1211 ext2_free_branches(inode, &nr, &nr+1, 2);
1212 }
1213 fallthrough;
1214 case EXT2_DIND_BLOCK:
1215 nr = i_data[EXT2_TIND_BLOCK];
1216 if (nr) {
1217 i_data[EXT2_TIND_BLOCK] = 0;
1218 mark_inode_dirty(inode);
1219 ext2_free_branches(inode, &nr, &nr+1, 3);
1220 }
1221 break;
1222 case EXT2_TIND_BLOCK:
1223 ;
1224 }
1225
1226 ext2_discard_reservation(inode);
1227
1228 mutex_unlock(&ei->truncate_mutex);
1229}
1230
1231static void ext2_truncate_blocks(struct inode *inode, loff_t offset)
1232{
1233 if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
1234 S_ISLNK(inode->i_mode)))
1235 return;
1236 if (ext2_inode_is_fast_symlink(inode))
1237 return;
1238
1239 filemap_invalidate_lock(inode->i_mapping);
1240 __ext2_truncate_blocks(inode, offset);
1241 filemap_invalidate_unlock(inode->i_mapping);
1242}
1243
1244static int ext2_setsize(struct inode *inode, loff_t newsize)
1245{
1246 int error;
1247
1248 if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
1249 S_ISLNK(inode->i_mode)))
1250 return -EINVAL;
1251 if (ext2_inode_is_fast_symlink(inode))
1252 return -EINVAL;
1253 if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
1254 return -EPERM;
1255
1256 inode_dio_wait(inode);
1257
1258 error = block_truncate_page(inode->i_mapping, newsize, ext2_get_block);
1259 if (error)
1260 return error;
1261
1262 filemap_invalidate_lock(inode->i_mapping);
1263 truncate_setsize(inode, newsize);
1264 __ext2_truncate_blocks(inode, newsize);
1265 filemap_invalidate_unlock(inode->i_mapping);
1266
1267 inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode));
1268 mark_inode_dirty(inode);
1269 if (inode_needs_sync(inode))
1270 sync_inode_metadata(inode, 1);
1271
1272 return 0;
1273}
1274
1275static struct ext2_inode *ext2_get_inode(struct super_block *sb, ino_t ino,
1276 struct buffer_head **p)
1277{
1278 struct buffer_head * bh;
1279 unsigned long block_group;
1280 unsigned long block;
1281 unsigned long offset;
1282 struct ext2_group_desc * gdp;
1283
1284 *p = NULL;
1285 if ((ino != EXT2_ROOT_INO && ino < EXT2_FIRST_INO(sb)) ||
1286 ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count))
1287 goto Einval;
1288
1289 block_group = (ino - 1) / EXT2_INODES_PER_GROUP(sb);
1290 gdp = ext2_get_group_desc(sb, block_group, NULL);
1291 if (!gdp)
1292 goto Egdp;
1293 /*
1294 * Figure out the offset within the block group inode table
1295 */
1296 offset = ((ino - 1) % EXT2_INODES_PER_GROUP(sb)) * EXT2_INODE_SIZE(sb);
1297 block = le32_to_cpu(gdp->bg_inode_table) +
1298 (offset >> EXT2_BLOCK_SIZE_BITS(sb));
1299 if (!(bh = sb_bread(sb, block)))
1300 goto Eio;
1301
1302 *p = bh;
1303 offset &= (EXT2_BLOCK_SIZE(sb) - 1);
1304 return (struct ext2_inode *) (bh->b_data + offset);
1305
1306Einval:
1307 ext2_error(sb, "ext2_get_inode", "bad inode number: %lu",
1308 (unsigned long) ino);
1309 return ERR_PTR(-EINVAL);
1310Eio:
1311 ext2_error(sb, "ext2_get_inode",
1312 "unable to read inode block - inode=%lu, block=%lu",
1313 (unsigned long) ino, block);
1314Egdp:
1315 return ERR_PTR(-EIO);
1316}
1317
1318void ext2_set_inode_flags(struct inode *inode)
1319{
1320 unsigned int flags = EXT2_I(inode)->i_flags;
1321
1322 inode->i_flags &= ~(S_SYNC | S_APPEND | S_IMMUTABLE | S_NOATIME |
1323 S_DIRSYNC);
1324 if (flags & EXT2_SYNC_FL)
1325 inode->i_flags |= S_SYNC;
1326 if (flags & EXT2_APPEND_FL)
1327 inode->i_flags |= S_APPEND;
1328 if (flags & EXT2_IMMUTABLE_FL)
1329 inode->i_flags |= S_IMMUTABLE;
1330 if (flags & EXT2_NOATIME_FL)
1331 inode->i_flags |= S_NOATIME;
1332 if (flags & EXT2_DIRSYNC_FL)
1333 inode->i_flags |= S_DIRSYNC;
1334}
1335
1336void ext2_set_file_ops(struct inode *inode)
1337{
1338 inode->i_op = &ext2_file_inode_operations;
1339 inode->i_fop = &ext2_file_operations;
1340 inode->i_mapping->a_ops = &ext2_aops;
1341}
1342
1343struct inode *ext2_iget (struct super_block *sb, unsigned long ino)
1344{
1345 struct ext2_inode_info *ei;
1346 struct buffer_head * bh = NULL;
1347 struct ext2_inode *raw_inode;
1348 struct inode *inode;
1349 long ret = -EIO;
1350 int n;
1351 uid_t i_uid;
1352 gid_t i_gid;
1353
1354 inode = iget_locked(sb, ino);
1355 if (!inode)
1356 return ERR_PTR(-ENOMEM);
1357 if (!(inode_state_read_once(inode) & I_NEW))
1358 return inode;
1359
1360 ei = EXT2_I(inode);
1361 ei->i_block_alloc_info = NULL;
1362
1363 raw_inode = ext2_get_inode(inode->i_sb, ino, &bh);
1364 if (IS_ERR(raw_inode)) {
1365 ret = PTR_ERR(raw_inode);
1366 goto bad_inode;
1367 }
1368
1369 inode->i_mode = le16_to_cpu(raw_inode->i_mode);
1370 i_uid = (uid_t)le16_to_cpu(raw_inode->i_uid_low);
1371 i_gid = (gid_t)le16_to_cpu(raw_inode->i_gid_low);
1372 if (!(test_opt (inode->i_sb, NO_UID32))) {
1373 i_uid |= le16_to_cpu(raw_inode->i_uid_high) << 16;
1374 i_gid |= le16_to_cpu(raw_inode->i_gid_high) << 16;
1375 }
1376 i_uid_write(inode, i_uid);
1377 i_gid_write(inode, i_gid);
1378 set_nlink(inode, le16_to_cpu(raw_inode->i_links_count));
1379 inode->i_size = le32_to_cpu(raw_inode->i_size);
1380 inode_set_atime(inode, (signed)le32_to_cpu(raw_inode->i_atime), 0);
1381 inode_set_ctime(inode, (signed)le32_to_cpu(raw_inode->i_ctime), 0);
1382 inode_set_mtime(inode, (signed)le32_to_cpu(raw_inode->i_mtime), 0);
1383 ei->i_dtime = le32_to_cpu(raw_inode->i_dtime);
1384 /* We now have enough fields to check if the inode was active or not.
1385 * This is needed because nfsd might try to access dead inodes
1386 * the test is that same one that e2fsck uses
1387 * NeilBrown 1999oct15
1388 */
1389 if (inode->i_nlink == 0) {
1390 if (inode->i_mode == 0 || ei->i_dtime) {
1391 /* this inode is deleted */
1392 ret = -ESTALE;
1393 } else {
1394 ext2_error(sb, __func__,
1395 "inode %lu has zero i_nlink with mode 0%o and no dtime, "
1396 "filesystem may be corrupt",
1397 ino, inode->i_mode);
1398 ret = -EFSCORRUPTED;
1399 }
1400 goto bad_inode;
1401 }
1402 inode->i_blocks = le32_to_cpu(raw_inode->i_blocks);
1403 ei->i_flags = le32_to_cpu(raw_inode->i_flags);
1404 ext2_set_inode_flags(inode);
1405 ei->i_faddr = le32_to_cpu(raw_inode->i_faddr);
1406 ei->i_frag_no = raw_inode->i_frag;
1407 ei->i_frag_size = raw_inode->i_fsize;
1408 ei->i_file_acl = le32_to_cpu(raw_inode->i_file_acl);
1409 ei->i_dir_acl = 0;
1410
1411 if (ei->i_file_acl &&
1412 !ext2_data_block_valid(EXT2_SB(sb), ei->i_file_acl, 1)) {
1413 ext2_error(sb, "ext2_iget", "bad extended attribute block %u",
1414 ei->i_file_acl);
1415 ret = -EFSCORRUPTED;
1416 goto bad_inode;
1417 }
1418
1419 if (S_ISREG(inode->i_mode))
1420 inode->i_size |= ((__u64)le32_to_cpu(raw_inode->i_size_high)) << 32;
1421 else
1422 ei->i_dir_acl = le32_to_cpu(raw_inode->i_dir_acl);
1423 if (i_size_read(inode) < 0) {
1424 ret = -EFSCORRUPTED;
1425 goto bad_inode;
1426 }
1427 ei->i_dtime = 0;
1428 inode->i_generation = le32_to_cpu(raw_inode->i_generation);
1429 ei->i_state = 0;
1430 ei->i_block_group = (ino - 1) / EXT2_INODES_PER_GROUP(inode->i_sb);
1431 ei->i_dir_start_lookup = 0;
1432
1433 /*
1434 * NOTE! The in-memory inode i_data array is in little-endian order
1435 * even on big-endian machines: we do NOT byteswap the block numbers!
1436 */
1437 for (n = 0; n < EXT2_N_BLOCKS; n++)
1438 ei->i_data[n] = raw_inode->i_block[n];
1439
1440 if (S_ISREG(inode->i_mode)) {
1441 ext2_set_file_ops(inode);
1442 } else if (S_ISDIR(inode->i_mode)) {
1443 inode->i_op = &ext2_dir_inode_operations;
1444 inode->i_fop = &ext2_dir_operations;
1445 inode->i_mapping->a_ops = &ext2_aops;
1446 } else if (S_ISLNK(inode->i_mode)) {
1447 if (ext2_inode_is_fast_symlink(inode)) {
1448 inode->i_link = (char *)ei->i_data;
1449 inode->i_op = &ext2_fast_symlink_inode_operations;
1450 nd_terminate_link(ei->i_data, inode->i_size,
1451 sizeof(ei->i_data) - 1);
1452 } else {
1453 inode->i_op = &ext2_symlink_inode_operations;
1454 inode_nohighmem(inode);
1455 inode->i_mapping->a_ops = &ext2_aops;
1456 }
1457 } else {
1458 inode->i_op = &ext2_special_inode_operations;
1459 if (raw_inode->i_block[0])
1460 init_special_inode(inode, inode->i_mode,
1461 old_decode_dev(le32_to_cpu(raw_inode->i_block[0])));
1462 else
1463 init_special_inode(inode, inode->i_mode,
1464 new_decode_dev(le32_to_cpu(raw_inode->i_block[1])));
1465 }
1466 brelse (bh);
1467 unlock_new_inode(inode);
1468 return inode;
1469
1470bad_inode:
1471 brelse(bh);
1472 iget_failed(inode);
1473 return ERR_PTR(ret);
1474}
1475
1476int ext2_write_inode(struct inode *inode, struct writeback_control *wbc)
1477{
1478 struct ext2_inode_info *ei = EXT2_I(inode);
1479 struct super_block *sb = inode->i_sb;
1480 ino_t ino = inode->i_ino;
1481 uid_t uid = i_uid_read(inode);
1482 gid_t gid = i_gid_read(inode);
1483 struct buffer_head * bh;
1484 struct ext2_inode * raw_inode = ext2_get_inode(sb, ino, &bh);
1485 int n;
1486 int err = 0;
1487
1488 if (IS_ERR(raw_inode))
1489 return -EIO;
1490
1491 /* For fields not tracking in the in-memory inode,
1492 * initialise them to zero for new inodes. */
1493 if (ei->i_state & EXT2_STATE_NEW)
1494 memset(raw_inode, 0, EXT2_SB(sb)->s_inode_size);
1495
1496 raw_inode->i_mode = cpu_to_le16(inode->i_mode);
1497 if (!(test_opt(sb, NO_UID32))) {
1498 raw_inode->i_uid_low = cpu_to_le16(low_16_bits(uid));
1499 raw_inode->i_gid_low = cpu_to_le16(low_16_bits(gid));
1500/*
1501 * Fix up interoperability with old kernels. Otherwise, old inodes get
1502 * re-used with the upper 16 bits of the uid/gid intact
1503 */
1504 if (!ei->i_dtime) {
1505 raw_inode->i_uid_high = cpu_to_le16(high_16_bits(uid));
1506 raw_inode->i_gid_high = cpu_to_le16(high_16_bits(gid));
1507 } else {
1508 raw_inode->i_uid_high = 0;
1509 raw_inode->i_gid_high = 0;
1510 }
1511 } else {
1512 raw_inode->i_uid_low = cpu_to_le16(fs_high2lowuid(uid));
1513 raw_inode->i_gid_low = cpu_to_le16(fs_high2lowgid(gid));
1514 raw_inode->i_uid_high = 0;
1515 raw_inode->i_gid_high = 0;
1516 }
1517 raw_inode->i_links_count = cpu_to_le16(inode->i_nlink);
1518 raw_inode->i_size = cpu_to_le32(inode->i_size);
1519 raw_inode->i_atime = cpu_to_le32(inode_get_atime_sec(inode));
1520 raw_inode->i_ctime = cpu_to_le32(inode_get_ctime_sec(inode));
1521 raw_inode->i_mtime = cpu_to_le32(inode_get_mtime_sec(inode));
1522
1523 raw_inode->i_blocks = cpu_to_le32(inode->i_blocks);
1524 raw_inode->i_dtime = cpu_to_le32(ei->i_dtime);
1525 raw_inode->i_flags = cpu_to_le32(ei->i_flags);
1526 raw_inode->i_faddr = cpu_to_le32(ei->i_faddr);
1527 raw_inode->i_frag = ei->i_frag_no;
1528 raw_inode->i_fsize = ei->i_frag_size;
1529 raw_inode->i_file_acl = cpu_to_le32(ei->i_file_acl);
1530 if (!S_ISREG(inode->i_mode))
1531 raw_inode->i_dir_acl = cpu_to_le32(ei->i_dir_acl);
1532 else {
1533 raw_inode->i_size_high = cpu_to_le32(inode->i_size >> 32);
1534 if (inode->i_size > 0x7fffffffULL) {
1535 if (!EXT2_HAS_RO_COMPAT_FEATURE(sb,
1536 EXT2_FEATURE_RO_COMPAT_LARGE_FILE) ||
1537 EXT2_SB(sb)->s_es->s_rev_level ==
1538 cpu_to_le32(EXT2_GOOD_OLD_REV)) {
1539 /* If this is the first large file
1540 * created, add a flag to the superblock.
1541 */
1542 spin_lock(&EXT2_SB(sb)->s_lock);
1543 ext2_update_dynamic_rev(sb);
1544 EXT2_SET_RO_COMPAT_FEATURE(sb,
1545 EXT2_FEATURE_RO_COMPAT_LARGE_FILE);
1546 spin_unlock(&EXT2_SB(sb)->s_lock);
1547 ext2_sync_super(sb, EXT2_SB(sb)->s_es, 1);
1548 }
1549 }
1550 }
1551
1552 raw_inode->i_generation = cpu_to_le32(inode->i_generation);
1553 if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) {
1554 if (old_valid_dev(inode->i_rdev)) {
1555 raw_inode->i_block[0] =
1556 cpu_to_le32(old_encode_dev(inode->i_rdev));
1557 raw_inode->i_block[1] = 0;
1558 } else {
1559 raw_inode->i_block[0] = 0;
1560 raw_inode->i_block[1] =
1561 cpu_to_le32(new_encode_dev(inode->i_rdev));
1562 raw_inode->i_block[2] = 0;
1563 }
1564 } else for (n = 0; n < EXT2_N_BLOCKS; n++)
1565 raw_inode->i_block[n] = ei->i_data[n];
1566 mark_buffer_dirty(bh);
1567 ei->i_state &= ~EXT2_STATE_NEW;
1568 brelse (bh);
1569 set_inode_metadata_writeback(inode);
1570 return err;
1571}
1572
1573int ext2_sync_inode_metadata(struct inode *inode, struct writeback_control *wbc)
1574{
1575 struct buffer_head *bh;
1576 struct ext2_inode *raw_inode = ext2_get_inode(inode->i_sb, inode->i_ino,
1577 &bh);
1578 int err = 0;
1579
1580 if (IS_ERR(raw_inode))
1581 return -EIO;
1582 err = mmb_sync(&EXT2_I(inode)->i_metadata_bhs);
1583 if (err) {
1584 ext2_error(inode->i_sb, __func__,
1585 "Error syncing inode metadata ino=%lu\n",
1586 (unsigned long)inode->i_ino);
1587 goto out;
1588 }
1589 sync_dirty_buffer(bh);
1590 if (buffer_write_io_error(bh)) {
1591 ext2_error(inode->i_sb, __func__,
1592 "IO error syncing inode %lu\n",
1593 (unsigned long)inode->i_ino);
1594 err = -EIO;
1595 }
1596out:
1597 brelse(bh);
1598 return err;
1599}
1600
1601int ext2_getattr(const struct mnt_idmap *idmap, const struct path *path,
1602 struct kstat *stat, u32 request_mask, unsigned int query_flags)
1603{
1604 struct inode *inode = d_inode(path->dentry);
1605 struct ext2_inode_info *ei = EXT2_I(inode);
1606 unsigned int flags;
1607
1608 flags = ei->i_flags & EXT2_FL_USER_VISIBLE;
1609 if (flags & EXT2_APPEND_FL)
1610 stat->attributes |= STATX_ATTR_APPEND;
1611 if (flags & EXT2_COMPR_FL)
1612 stat->attributes |= STATX_ATTR_COMPRESSED;
1613 if (flags & EXT2_IMMUTABLE_FL)
1614 stat->attributes |= STATX_ATTR_IMMUTABLE;
1615 if (flags & EXT2_NODUMP_FL)
1616 stat->attributes |= STATX_ATTR_NODUMP;
1617 stat->attributes_mask |= (STATX_ATTR_APPEND |
1618 STATX_ATTR_COMPRESSED |
1619 STATX_ATTR_ENCRYPTED |
1620 STATX_ATTR_IMMUTABLE |
1621 STATX_ATTR_NODUMP);
1622
1623 generic_fillattr(&nop_mnt_idmap, request_mask, inode, stat);
1624 return 0;
1625}
1626
1627int ext2_setattr(const struct mnt_idmap *idmap, struct dentry *dentry,
1628 struct iattr *iattr)
1629{
1630 struct inode *inode = d_inode(dentry);
1631 int error;
1632
1633 error = setattr_prepare(&nop_mnt_idmap, dentry, iattr);
1634 if (error)
1635 return error;
1636
1637 if (is_quota_modification(&nop_mnt_idmap, inode, iattr)) {
1638 error = dquot_initialize(inode);
1639 if (error)
1640 return error;
1641 }
1642 if (i_uid_needs_update(&nop_mnt_idmap, iattr, inode) ||
1643 i_gid_needs_update(&nop_mnt_idmap, iattr, inode)) {
1644 error = dquot_transfer(&nop_mnt_idmap, inode, iattr);
1645 if (error)
1646 return error;
1647 }
1648 if (iattr->ia_valid & ATTR_SIZE && iattr->ia_size != inode->i_size) {
1649 error = ext2_setsize(inode, iattr->ia_size);
1650 if (error)
1651 return error;
1652 }
1653 setattr_copy(&nop_mnt_idmap, inode, iattr);
1654 if (iattr->ia_valid & ATTR_MODE)
1655 error = posix_acl_chmod(&nop_mnt_idmap, dentry, inode->i_mode);
1656 mark_inode_dirty(inode);
1657
1658 return error;
1659}