projects/linux·blob assoc-array-fixes · refs

1652 lines · 46.8 KiB

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{
331 struct ext2_block_alloc_info *block_i;
332
333 block_i = EXT2_I(inode)->i_block_alloc_info;
334
335 /*
336 * try the heuristic for sequential allocation,
337 * failing that at least try to get decent locality.
338 */
339 if (block_i && (block == block_i->last_alloc_logical_block + 1)
340 && (block_i->last_alloc_physical_block != 0)) {
341 return block_i->last_alloc_physical_block + 1;
342 }
343
344 return ext2_find_near(inode, partial);
345}
346
347/**
348 * ext2_blks_to_allocate: Look up the block map and count the number
349 * of direct blocks need to be allocated for the given branch.
350 *
351 * @branch: chain of indirect blocks
352 * @k: number of blocks need for indirect blocks
353 * @blks: number of data blocks to be mapped.
354 * @blocks_to_boundary: the offset in the indirect block
355 *
356 * return the number of direct blocks to allocate.
357 */
358static int
359ext2_blks_to_allocate(Indirect * branch, int k, unsigned long blks,
360 int blocks_to_boundary)
361{
362 unsigned long count = 0;
363
364 /*
365 * Simple case, [t,d]Indirect block(s) has not allocated yet
366 * then it's clear blocks on that path have not allocated
367 */
368 if (k > 0) {
369 /* right now don't hanel cross boundary allocation */
370 if (blks < blocks_to_boundary + 1)
371 count += blks;
372 else
373 count += blocks_to_boundary + 1;
374 return count;
375 }
376
377 count++;
378 while (count < blks && count <= blocks_to_boundary
379 && le32_to_cpu(*(branch[0].p + count)) == 0) {
380 count++;
381 }
382 return count;
383}
384
385/**
386 * ext2_alloc_blocks: Allocate multiple blocks needed for a branch.
387 * @inode: Owner.
388 * @goal: Preferred place for allocation.
389 * @indirect_blks: The number of blocks needed to allocate for indirect blocks.
390 * @blks: The number of blocks need to allocate for direct blocks.
391 * @new_blocks: On return it will store the new block numbers for
392 * the indirect blocks(if needed) and the first direct block.
393 * @err: Error pointer.
394 *
395 * Return: Number of blocks allocated.
396 */
397static int ext2_alloc_blocks(struct inode *inode,
398 ext2_fsblk_t goal, int indirect_blks, int blks,
399 ext2_fsblk_t new_blocks[4], int *err)
400{
401 int target, i;
402 unsigned long count = 0;
403 int index = 0;
404 ext2_fsblk_t current_block = 0;
405 int ret = 0;
406
407 /*
408 * Here we try to allocate the requested multiple blocks at once,
409 * on a best-effort basis.
410 * To build a branch, we should allocate blocks for
411 * the indirect blocks(if not allocated yet), and at least
412 * the first direct block of this branch. That's the
413 * minimum number of blocks need to allocate(required)
414 */
415 target = blks + indirect_blks;
416
417 while (1) {
418 count = target;
419 /* allocating blocks for indirect blocks and direct blocks */
420 current_block = ext2_new_blocks(inode, goal, &count, err, 0);
421 if (*err)
422 goto failed_out;
423
424 target -= count;
425 /* allocate blocks for indirect blocks */
426 while (index < indirect_blks && count) {
427 new_blocks[index++] = current_block++;
428 count--;
429 }
430
431 if (count > 0)
432 break;
433 }
434
435 /* save the new block number for the first direct block */
436 new_blocks[index] = current_block;
437
438 /* total number of blocks allocated for direct blocks */
439 ret = count;
440 *err = 0;
441 return ret;
442failed_out:
443 for (i = 0; i <index; i++)
444 ext2_free_blocks(inode, new_blocks[i], 1);
445 if (index)
446 mark_inode_dirty(inode);
447 return ret;
448}
449
450/**
451 * ext2_alloc_branch - allocate and set up a chain of blocks.
452 * @inode: owner
453 * @indirect_blks: depth of the chain (number of blocks to allocate)
454 * @blks: number of allocated direct blocks
455 * @goal: preferred place for allocation
456 * @offsets: offsets (in the blocks) to store the pointers to next.
457 * @branch: place to store the chain in.
458 *
459 * This function allocates @num blocks, zeroes out all but the last one,
460 * links them into chain and (if we are synchronous) writes them to disk.
461 * In other words, it prepares a branch that can be spliced onto the
462 * inode. It stores the information about that chain in the branch[], in
463 * the same format as ext2_get_branch() would do. We are calling it after
464 * we had read the existing part of chain and partial points to the last
465 * triple of that (one with zero ->key). Upon the exit we have the same
466 * picture as after the successful ext2_get_block(), except that in one
467 * place chain is disconnected - *branch->p is still zero (we did not
468 * set the last link), but branch->key contains the number that should
469 * be placed into *branch->p to fill that gap.
470 *
471 * If allocation fails we free all blocks we've allocated (and forget
472 * their buffer_heads) and return the error value the from failed
473 * ext2_alloc_block() (normally -ENOSPC). Otherwise we set the chain
474 * as described above and return 0.
475 */
476
477static int ext2_alloc_branch(struct inode *inode,
478 int indirect_blks, int *blks, ext2_fsblk_t goal,
479 int *offsets, Indirect *branch)
480{
481 int blocksize = inode->i_sb->s_blocksize;
482 int i, n = 0;
483 int err = 0;
484 struct buffer_head *bh;
485 int num;
486 ext2_fsblk_t new_blocks[4];
487 ext2_fsblk_t current_block;
488
489 num = ext2_alloc_blocks(inode, goal, indirect_blks,
490 *blks, new_blocks, &err);
491 if (err)
492 return err;
493
494 branch[0].key = cpu_to_le32(new_blocks[0]);
495 /*
496 * metadata blocks and data blocks are allocated.
497 */
498 for (n = 1; n <= indirect_blks; n++) {
499 /*
500 * Get buffer_head for parent block, zero it out
501 * and set the pointer to new one, then send
502 * parent to disk.
503 */
504 bh = sb_getblk(inode->i_sb, new_blocks[n-1]);
505 if (unlikely(!bh)) {
506 err = -ENOMEM;
507 goto failed;
508 }
509 branch[n].bh = bh;
510 lock_buffer(bh);
511 memset(bh->b_data, 0, blocksize);
512 branch[n].p = (__le32 *) bh->b_data + offsets[n];
513 branch[n].key = cpu_to_le32(new_blocks[n]);
514 *branch[n].p = branch[n].key;
515 if ( n == indirect_blks) {
516 current_block = new_blocks[n];
517 /*
518 * End of chain, update the last new metablock of
519 * the chain to point to the new allocated
520 * data blocks numbers
521 */
522 for (i=1; i < num; i++)
523 *(branch[n].p + i) = cpu_to_le32(++current_block);
524 }
525 set_buffer_uptodate(bh);
526 unlock_buffer(bh);
527 mmb_mark_buffer_dirty(bh, &EXT2_I(inode)->i_metadata_bhs);
528 /* We used to sync bh here if IS_SYNC(inode).
529 * But we now rely upon generic_write_sync()
530 * and b_inode_buffers. But not for directories.
531 */
532 if (S_ISDIR(inode->i_mode) && IS_DIRSYNC(inode))
533 sync_dirty_buffer(bh);
534 }
535 *blks = num;
536 return err;
537
538failed:
539 for (i = 1; i < n; i++)
540 bforget(branch[i].bh);
541 for (i = 0; i < indirect_blks; i++)
542 ext2_free_blocks(inode, new_blocks[i], 1);
543 ext2_free_blocks(inode, new_blocks[i], num);
544 return err;
545}
546
547/**
548 * ext2_splice_branch - splice the allocated branch onto inode.
549 * @inode: owner
550 * @block: (logical) number of block we are adding
551 * @where: location of missing link
552 * @num: number of indirect blocks we are adding
553 * @blks: number of direct blocks we are adding
554 *
555 * This function fills the missing link and does all housekeeping needed in
556 * inode (->i_blocks, etc.). In case of success we end up with the full
557 * chain to new block and return 0.
558 */
559static void ext2_splice_branch(struct inode *inode,
560 long block, Indirect *where, int num, int blks)
561{
562 int i;
563 struct ext2_block_alloc_info *block_i;
564 ext2_fsblk_t current_block;
565
566 block_i = EXT2_I(inode)->i_block_alloc_info;
567
568 /* XXX LOCKING probably should have i_meta_lock ?*/
569 /* That's it */
570
571 *where->p = where->key;
572
573 /*
574 * Update the host buffer_head or inode to point to more just allocated
575 * direct blocks blocks
576 */
577 if (num == 0 && blks > 1) {
578 current_block = le32_to_cpu(where->key) + 1;
579 for (i = 1; i < blks; i++)
580 *(where->p + i ) = cpu_to_le32(current_block++);
581 }
582
583 /*
584 * update the most recently allocated logical & physical block
585 * in i_block_alloc_info, to assist find the proper goal block for next
586 * allocation
587 */
588 if (block_i) {
589 block_i->last_alloc_logical_block = block + blks - 1;
590 block_i->last_alloc_physical_block =
591 le32_to_cpu(where[num].key) + blks - 1;
592 }
593
594 /* We are done with atomic stuff, now do the rest of housekeeping */
595
596 /* had we spliced it onto indirect block? */
597 if (where->bh)
598 mmb_mark_buffer_dirty(where->bh, &EXT2_I(inode)->i_metadata_bhs);
599
600 inode_set_ctime_current(inode);
601 mark_inode_dirty(inode);
602}
603
604/*
605 * Allocation strategy is simple: if we have to allocate something, we will
606 * have to go the whole way to leaf. So let's do it before attaching anything
607 * to tree, set linkage between the newborn blocks, write them if sync is
608 * required, recheck the path, free and repeat if check fails, otherwise
609 * set the last missing link (that will protect us from any truncate-generated
610 * removals - all blocks on the path are immune now) and possibly force the
611 * write on the parent block.
612 * That has a nice additional property: no special recovery from the failed
613 * allocations is needed - we simply release blocks and do not touch anything
614 * reachable from inode.
615 *
616 * `handle' can be NULL if create == 0.
617 *
618 * return > 0, # of blocks mapped or allocated.
619 * return = 0, if plain lookup failed.
620 * return < 0, error case.
621 */
622static int ext2_get_blocks(struct inode *inode,
623 sector_t iblock, unsigned long maxblocks,
624 u32 *bno, bool *new, bool *boundary,
625 int create)
626{
627 int err;
628 int offsets[4];
629 Indirect chain[4];
630 Indirect *partial;
631 ext2_fsblk_t goal;
632 int indirect_blks;
633 int blocks_to_boundary = 0;
634 int depth;
635 struct ext2_inode_info *ei = EXT2_I(inode);
636 int count = 0;
637 ext2_fsblk_t first_block = 0;
638
639 if (WARN_ON_ONCE(maxblocks == 0))
640 return -EINVAL;
641
642 depth = ext2_block_to_path(inode,iblock,offsets,&blocks_to_boundary);
643
644 if (depth == 0)
645 return -EIO;
646
647 partial = ext2_get_branch(inode, depth, offsets, chain, &err);
648 /* Simplest case - block found, no allocation needed */
649 if (!partial) {
650 first_block = le32_to_cpu(chain[depth - 1].key);
651 count++;
652 /*map more blocks*/
653 while (count < maxblocks && count <= blocks_to_boundary) {
654 ext2_fsblk_t blk;
655
656 if (!verify_chain(chain, chain + depth - 1)) {
657 /*
658 * Indirect block might be removed by
659 * truncate while we were reading it.
660 * Handling of that case: forget what we've
661 * got now, go to reread.
662 */
663 err = -EAGAIN;
664 count = 0;
665 partial = chain + depth - 1;
666 break;
667 }
668 blk = le32_to_cpu(*(chain[depth-1].p + count));
669 if (blk == first_block + count)
670 count++;
671 else
672 break;
673 }
674 if (err != -EAGAIN)
675 goto got_it;
676 }
677
678 /* Next simple case - plain lookup or failed read of indirect block */
679 if (!create || err == -EIO)
680 goto cleanup;
681
682 mutex_lock(&ei->truncate_mutex);
683 /*
684 * If the indirect block is missing while we are reading
685 * the chain(ext2_get_branch() returns -EAGAIN err), or
686 * if the chain has been changed after we grab the semaphore,
687 * (either because another process truncated this branch, or
688 * another get_block allocated this branch) re-grab the chain to see if
689 * the request block has been allocated or not.
690 *
691 * Since we already block the truncate/other get_block
692 * at this point, we will have the current copy of the chain when we
693 * splice the branch into the tree.
694 */
695 if (err == -EAGAIN || !verify_chain(chain, partial)) {
696 while (partial > chain) {
697 brelse(partial->bh);
698 partial--;
699 }
700 partial = ext2_get_branch(inode, depth, offsets, chain, &err);
701 if (!partial) {
702 count++;
703 mutex_unlock(&ei->truncate_mutex);
704 goto got_it;
705 }
706
707 if (err) {
708 mutex_unlock(&ei->truncate_mutex);
709 goto cleanup;
710 }
711 }
712
713 /*
714 * Okay, we need to do block allocation. Lazily initialize the block
715 * allocation info here if necessary
716 */
717 if (S_ISREG(inode->i_mode) && (!ei->i_block_alloc_info))
718 ext2_init_block_alloc_info(inode);
719
720 goal = ext2_find_goal(inode, iblock, partial);
721
722 /* the number of blocks need to allocate for [d,t]indirect blocks */
723 indirect_blks = (chain + depth) - partial - 1;
724 /*
725 * Next look up the indirect map to count the total number of
726 * direct blocks to allocate for this branch.
727 */
728 count = ext2_blks_to_allocate(partial, indirect_blks,
729 maxblocks, blocks_to_boundary);
730 /*
731 * XXX ???? Block out ext2_truncate while we alter the tree
732 */
733 err = ext2_alloc_branch(inode, indirect_blks, &count, goal,
734 offsets + (partial - chain), partial);
735
736 if (err) {
737 mutex_unlock(&ei->truncate_mutex);
738 goto cleanup;
739 }
740
741 *new = true;
742
743 ext2_splice_branch(inode, iblock, partial, indirect_blks, count);
744 mutex_unlock(&ei->truncate_mutex);
745got_it:
746 if (count > blocks_to_boundary)
747 *boundary = true;
748 err = count;
749 /* Clean up and exit */
750 partial = chain + depth - 1; /* the whole chain */
751cleanup:
752 while (partial > chain) {
753 brelse(partial->bh);
754 partial--;
755 }
756 if (err > 0)
757 *bno = le32_to_cpu(chain[depth-1].key);
758 return err;
759}
760
761int ext2_get_block(struct inode *inode, sector_t iblock,
762 struct buffer_head *bh_result, int create)
763{
764 unsigned max_blocks = bh_result->b_size >> inode->i_blkbits;
765 bool new = false, boundary = false;
766 u32 bno;
767 int ret;
768
769 ret = ext2_get_blocks(inode, iblock, max_blocks, &bno, &new, &boundary,
770 create);
771 if (ret <= 0)
772 return ret;
773
774 map_bh(bh_result, inode->i_sb, bno);
775 bh_result->b_size = (ret << inode->i_blkbits);
776 if (new)
777 set_buffer_new(bh_result);
778 if (boundary)
779 set_buffer_boundary(bh_result);
780 return 0;
781
782}
783
784static int ext2_iomap_begin(struct inode *inode, loff_t offset, loff_t length,
785 unsigned flags, struct iomap *iomap, struct iomap *srcmap)
786{
787 unsigned int blkbits = inode->i_blkbits;
788 unsigned long first_block = offset >> blkbits;
789 unsigned long max_blocks = (length + (1 << blkbits) - 1) >> blkbits;
790 bool new = false, boundary = false;
791 u32 bno;
792 int ret;
793 bool create = flags & IOMAP_WRITE;
794
795 /*
796 * For writes that could fill holes inside i_size on a
797 * DIO_SKIP_HOLES filesystem we forbid block creations: only
798 * overwrites are permitted.
799 */
800 if ((flags & IOMAP_DIRECT) &&
801 (first_block << blkbits) < i_size_read(inode))
802 create = 0;
803
804 /*
805 * Writes that span EOF might trigger an IO size update on completion,
806 * so consider them to be dirty for the purposes of O_DSYNC even if
807 * there is no other metadata changes pending or have been made here.
808 */
809 if ((flags & IOMAP_WRITE) && offset + length > i_size_read(inode))
810 iomap->flags |= IOMAP_F_DIRTY;
811
812 ret = ext2_get_blocks(inode, first_block, max_blocks,
813 &bno, &new, &boundary, create);
814 if (ret < 0)
815 return ret;
816
817 iomap->flags = 0;
818 iomap->offset = (u64)first_block << blkbits;
819 iomap->bdev = inode->i_sb->s_bdev;
820
821 if (ret == 0) {
822 /*
823 * Switch to buffered-io for writing to holes in a non-extent
824 * based filesystem to avoid stale data exposure problem.
825 */
826 if (!create && (flags & IOMAP_WRITE) && (flags & IOMAP_DIRECT))
827 return -ENOTBLK;
828 iomap->type = IOMAP_HOLE;
829 iomap->addr = IOMAP_NULL_ADDR;
830 iomap->length = 1 << blkbits;
831 } else {
832 iomap->type = IOMAP_MAPPED;
833 iomap->addr = (u64)bno << blkbits;
834 iomap->length = (u64)ret << blkbits;
835 iomap->flags |= IOMAP_F_MERGED;
836 }
837
838 if (new)
839 iomap->flags |= IOMAP_F_NEW;
840 return 0;
841}
842
843static int
844ext2_iomap_end(struct inode *inode, loff_t offset, loff_t length,
845 ssize_t written, unsigned flags, struct iomap *iomap)
846{
847 /*
848 * Switch to buffered-io in case of any error.
849 * Blocks allocated can be used by the buffered-io path.
850 */
851 if ((flags & IOMAP_DIRECT) && (flags & IOMAP_WRITE) && written == 0)
852 return -ENOTBLK;
853
854 if (iomap->type == IOMAP_MAPPED &&
855 written < length &&
856 (flags & IOMAP_WRITE))
857 ext2_write_failed(inode->i_mapping, offset + length);
858 return 0;
859}
860
861static DEFINE_IOMAP_ITER_NEXT_END(ext2_iomap_next, ext2_iomap_begin,
862 ext2_iomap_end);
863
864const struct iomap_ops ext2_iomap_ops = {
865 .iomap_next = ext2_iomap_next,
866};
867
868int ext2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
869 u64 start, u64 len)
870{
871 int ret;
872 loff_t i_size;
873
874 inode_lock(inode);
875 i_size = i_size_read(inode);
876 /*
877 * iomap_fiemap() returns EINVAL for 0 length. Make sure we don't trim
878 * length to 0 but still trim the range as much as possible since
879 * ext2_get_blocks() iterates unmapped space block by block which is
880 * slow.
881 */
882 if (i_size == 0)
883 i_size = 1;
884 len = min_t(u64, len, i_size);
885 ret = iomap_fiemap(inode, fieinfo, start, len, &ext2_iomap_ops);
886 inode_unlock(inode);
887
888 return ret;
889}
890
891static int ext2_read_folio(struct file *file, struct folio *folio)
892{
893 return mpage_read_folio(folio, ext2_get_block);
894}
895
896static void ext2_readahead(struct readahead_control *rac)
897{
898 mpage_readahead(rac, ext2_get_block);
899}
900
901static int
902ext2_write_begin(const struct kiocb *iocb, struct address_space *mapping,
903 loff_t pos, unsigned len, struct folio **foliop, void **fsdata)
904{
905 int ret;
906
907 ret = block_write_begin(mapping, pos, len, foliop, ext2_get_block);
908 if (ret < 0)
909 ext2_write_failed(mapping, pos + len);
910 return ret;
911}
912
913static int ext2_write_end(const struct kiocb *iocb,
914 struct address_space *mapping,
915 loff_t pos, unsigned len, unsigned copied,
916 struct folio *folio, void *fsdata)
917{
918 int ret;
919
920 ret = generic_write_end(iocb, mapping, pos, len, copied, folio, fsdata);
921 if (ret < len)
922 ext2_write_failed(mapping, pos + len);
923 return ret;
924}
925
926static sector_t ext2_bmap(struct address_space *mapping, sector_t block)
927{
928 return generic_block_bmap(mapping,block,ext2_get_block);
929}
930
931static int
932ext2_writepages(struct address_space *mapping, struct writeback_control *wbc)
933{
934 return mpage_writepages(mapping, wbc, ext2_get_block);
935}
936
937
938const struct address_space_operations ext2_aops = {
939 .dirty_folio = block_dirty_folio,
940 .invalidate_folio = block_invalidate_folio,
941 .read_folio = ext2_read_folio,
942 .readahead = ext2_readahead,
943 .write_begin = ext2_write_begin,
944 .write_end = ext2_write_end,
945 .bmap = ext2_bmap,
946 .writepages = ext2_writepages,
947 .migrate_folio = buffer_migrate_folio,
948 .is_partially_uptodate = block_is_partially_uptodate,
949 .error_remove_folio = generic_error_remove_folio,
950};
951
952
953/*
954 * Probably it should be a library function... search for first non-zero word
955 * or memcmp with zero_page, whatever is better for particular architecture.
956 * Linus?
957 */
958static inline int all_zeroes(__le32 *p, __le32 *q)
959{
960 while (p < q)
961 if (*p++)
962 return 0;
963 return 1;
964}
965
966/**
967 * ext2_find_shared - find the indirect blocks for partial truncation.
968 * @inode: inode in question
969 * @depth: depth of the affected branch
970 * @offsets: offsets of pointers in that branch (see ext2_block_to_path)
971 * @chain: place to store the pointers to partial indirect blocks
972 * @top: place to the (detached) top of branch
973 *
974 * This is a helper function used by ext2_truncate().
975 *
976 * When we do truncate() we may have to clean the ends of several indirect
977 * blocks but leave the blocks themselves alive. Block is partially
978 * truncated if some data below the new i_size is referred from it (and
979 * it is on the path to the first completely truncated data block, indeed).
980 * We have to free the top of that path along with everything to the right
981 * of the path. Since no allocation past the truncation point is possible
982 * until ext2_truncate() finishes, we may safely do the latter, but top
983 * of branch may require special attention - pageout below the truncation
984 * point might try to populate it.
985 *
986 * We atomically detach the top of branch from the tree, store the block
987 * number of its root in *@top, pointers to buffer_heads of partially
988 * truncated blocks - in @chain[].bh and pointers to their last elements
989 * that should not be removed - in @chain[].p. Return value is the pointer
990 * to last filled element of @chain.
991 *
992 * The work left to caller to do the actual freeing of subtrees:
993 * a) free the subtree starting from *@top
994 * b) free the subtrees whose roots are stored in
995 * (@chain[i].p+1 .. end of @chain[i].bh->b_data)
996 * c) free the subtrees growing from the inode past the @chain[0].p
997 * (no partially truncated stuff there).
998 */
999
1000static Indirect *ext2_find_shared(struct inode *inode,
1001 int depth,
1002 int offsets[4],
1003 Indirect chain[4],
1004 __le32 *top)
1005{
1006 Indirect *partial, *p;
1007 int k, err;
1008
1009 *top = 0;
1010 for (k = depth; k > 1 && !offsets[k-1]; k--)
1011 ;
1012 partial = ext2_get_branch(inode, k, offsets, chain, &err);
1013 if (!partial)
1014 partial = chain + k-1;
1015 /*
1016 * If the branch acquired continuation since we've looked at it -
1017 * fine, it should all survive and (new) top doesn't belong to us.
1018 */
1019 write_lock(&EXT2_I(inode)->i_meta_lock);
1020 if (!partial->key && *partial->p) {
1021 write_unlock(&EXT2_I(inode)->i_meta_lock);
1022 goto no_top;
1023 }
1024 for (p=partial; p>chain && all_zeroes((__le32*)p->bh->b_data,p->p); p--)
1025 ;
1026 /*
1027 * OK, we've found the last block that must survive. The rest of our
1028 * branch should be detached before unlocking. However, if that rest
1029 * of branch is all ours and does not grow immediately from the inode
1030 * it's easier to cheat and just decrement partial->p.
1031 */
1032 if (p == chain + k - 1 && p > chain) {
1033 p->p--;
1034 } else {
1035 *top = *p->p;
1036 *p->p = 0;
1037 }
1038 write_unlock(&EXT2_I(inode)->i_meta_lock);
1039
1040 while(partial > p)
1041 {
1042 brelse(partial->bh);
1043 partial--;
1044 }
1045no_top:
1046 return partial;
1047}
1048
1049/**
1050 * ext2_free_data - free a list of data blocks
1051 * @inode: inode we are dealing with
1052 * @p: array of block numbers
1053 * @q: points immediately past the end of array
1054 *
1055 * We are freeing all blocks referred from that array (numbers are
1056 * stored as little-endian 32-bit) and updating @inode->i_blocks
1057 * appropriately.
1058 */
1059static inline void ext2_free_data(struct inode *inode, __le32 *p, __le32 *q)
1060{
1061 ext2_fsblk_t block_to_free = 0, count = 0;
1062 ext2_fsblk_t nr;
1063
1064 for ( ; p < q ; p++) {
1065 nr = le32_to_cpu(*p);
1066 if (nr) {
1067 *p = 0;
1068 /* accumulate blocks to free if they're contiguous */
1069 if (count == 0)
1070 goto free_this;
1071 else if (block_to_free == nr - count)
1072 count++;
1073 else {
1074 ext2_free_blocks (inode, block_to_free, count);
1075 mark_inode_dirty(inode);
1076 free_this:
1077 block_to_free = nr;
1078 count = 1;
1079 }
1080 }
1081 }
1082 if (count > 0) {
1083 ext2_free_blocks (inode, block_to_free, count);
1084 mark_inode_dirty(inode);
1085 }
1086}
1087
1088/**
1089 * ext2_free_branches - free an array of branches
1090 * @inode: inode we are dealing with
1091 * @p: array of block numbers
1092 * @q: pointer immediately past the end of array
1093 * @depth: depth of the branches to free
1094 *
1095 * We are freeing all blocks referred from these branches (numbers are
1096 * stored as little-endian 32-bit) and updating @inode->i_blocks
1097 * appropriately.
1098 */
1099static void ext2_free_branches(struct inode *inode, __le32 *p, __le32 *q, int depth)
1100{
1101 struct buffer_head * bh;
1102 ext2_fsblk_t nr;
1103
1104 if (depth--) {
1105 int addr_per_block = EXT2_ADDR_PER_BLOCK(inode->i_sb);
1106 for ( ; p < q ; p++) {
1107 nr = le32_to_cpu(*p);
1108 if (!nr)
1109 continue;
1110 *p = 0;
1111 bh = sb_bread(inode->i_sb, nr);
1112 /*
1113 * A read failure? Report error and clear slot
1114 * (should be rare).
1115 */
1116 if (!bh) {
1117 ext2_error(inode->i_sb, "ext2_free_branches",
1118 "Read failure, inode=%llu, block=%ld",
1119 inode->i_ino, nr);
1120 continue;
1121 }
1122 ext2_free_branches(inode,
1123 (__le32*)bh->b_data,
1124 (__le32*)bh->b_data + addr_per_block,
1125 depth);
1126 bforget(bh);
1127 ext2_free_blocks(inode, nr, 1);
1128 mark_inode_dirty(inode);
1129 }
1130 } else
1131 ext2_free_data(inode, p, q);
1132}
1133
1134/* mapping->invalidate_lock must be held when calling this function */
1135static void __ext2_truncate_blocks(struct inode *inode, loff_t offset)
1136{
1137 __le32 *i_data = EXT2_I(inode)->i_data;
1138 struct ext2_inode_info *ei = EXT2_I(inode);
1139 int addr_per_block = EXT2_ADDR_PER_BLOCK(inode->i_sb);
1140 int offsets[4];
1141 Indirect chain[4];
1142 Indirect *partial;
1143 __le32 nr = 0;
1144 int n;
1145 long iblock;
1146 unsigned blocksize;
1147 blocksize = inode->i_sb->s_blocksize;
1148 iblock = (offset + blocksize-1) >> EXT2_BLOCK_SIZE_BITS(inode->i_sb);
1149
1150
1151 n = ext2_block_to_path(inode, iblock, offsets, NULL);
1152 if (n == 0)
1153 return;
1154
1155 /*
1156 * From here we block out all ext2_get_block() callers who want to
1157 * modify the block allocation tree.
1158 */
1159 mutex_lock(&ei->truncate_mutex);
1160
1161 if (n == 1) {
1162 ext2_free_data(inode, i_data+offsets[0],
1163 i_data + EXT2_NDIR_BLOCKS);
1164 goto do_indirects;
1165 }
1166
1167 partial = ext2_find_shared(inode, n, offsets, chain, &nr);
1168 /* Kill the top of shared branch (already detached) */
1169 if (nr) {
1170 if (partial == chain)
1171 mark_inode_dirty(inode);
1172 else
1173 mmb_mark_buffer_dirty(partial->bh,
1174 &EXT2_I(inode)->i_metadata_bhs);
1175 ext2_free_branches(inode, &nr, &nr+1, (chain+n-1) - partial);
1176 }
1177 /* Clear the ends of indirect blocks on the shared branch */
1178 while (partial > chain) {
1179 ext2_free_branches(inode,
1180 partial->p + 1,
1181 (__le32*)partial->bh->b_data+addr_per_block,
1182 (chain+n-1) - partial);
1183 mmb_mark_buffer_dirty(partial->bh,
1184 &EXT2_I(inode)->i_metadata_bhs);
1185 brelse (partial->bh);
1186 partial--;
1187 }
1188do_indirects:
1189 /* Kill the remaining (whole) subtrees */
1190 switch (offsets[0]) {
1191 default:
1192 nr = i_data[EXT2_IND_BLOCK];
1193 if (nr) {
1194 i_data[EXT2_IND_BLOCK] = 0;
1195 mark_inode_dirty(inode);
1196 ext2_free_branches(inode, &nr, &nr+1, 1);
1197 }
1198 fallthrough;
1199 case EXT2_IND_BLOCK:
1200 nr = i_data[EXT2_DIND_BLOCK];
1201 if (nr) {
1202 i_data[EXT2_DIND_BLOCK] = 0;
1203 mark_inode_dirty(inode);
1204 ext2_free_branches(inode, &nr, &nr+1, 2);
1205 }
1206 fallthrough;
1207 case EXT2_DIND_BLOCK:
1208 nr = i_data[EXT2_TIND_BLOCK];
1209 if (nr) {
1210 i_data[EXT2_TIND_BLOCK] = 0;
1211 mark_inode_dirty(inode);
1212 ext2_free_branches(inode, &nr, &nr+1, 3);
1213 }
1214 break;
1215 case EXT2_TIND_BLOCK:
1216 ;
1217 }
1218
1219 ext2_discard_reservation(inode);
1220
1221 mutex_unlock(&ei->truncate_mutex);
1222}
1223
1224static void ext2_truncate_blocks(struct inode *inode, loff_t offset)
1225{
1226 if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
1227 S_ISLNK(inode->i_mode)))
1228 return;
1229 if (ext2_inode_is_fast_symlink(inode))
1230 return;
1231
1232 filemap_invalidate_lock(inode->i_mapping);
1233 __ext2_truncate_blocks(inode, offset);
1234 filemap_invalidate_unlock(inode->i_mapping);
1235}
1236
1237static int ext2_setsize(struct inode *inode, loff_t newsize)
1238{
1239 int error;
1240
1241 if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
1242 S_ISLNK(inode->i_mode)))
1243 return -EINVAL;
1244 if (ext2_inode_is_fast_symlink(inode))
1245 return -EINVAL;
1246 if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
1247 return -EPERM;
1248
1249 inode_dio_wait(inode);
1250
1251 error = block_truncate_page(inode->i_mapping, newsize, ext2_get_block);
1252 if (error)
1253 return error;
1254
1255 filemap_invalidate_lock(inode->i_mapping);
1256 truncate_setsize(inode, newsize);
1257 __ext2_truncate_blocks(inode, newsize);
1258 filemap_invalidate_unlock(inode->i_mapping);
1259
1260 inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode));
1261 mark_inode_dirty(inode);
1262 if (inode_needs_sync(inode))
1263 sync_inode_metadata(inode, 1);
1264
1265 return 0;
1266}
1267
1268static struct ext2_inode *ext2_get_inode(struct super_block *sb, ino_t ino,
1269 struct buffer_head **p)
1270{
1271 struct buffer_head * bh;
1272 unsigned long block_group;
1273 unsigned long block;
1274 unsigned long offset;
1275 struct ext2_group_desc * gdp;
1276
1277 *p = NULL;
1278 if ((ino != EXT2_ROOT_INO && ino < EXT2_FIRST_INO(sb)) ||
1279 ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count))
1280 goto Einval;
1281
1282 block_group = (ino - 1) / EXT2_INODES_PER_GROUP(sb);
1283 gdp = ext2_get_group_desc(sb, block_group, NULL);
1284 if (!gdp)
1285 goto Egdp;
1286 /*
1287 * Figure out the offset within the block group inode table
1288 */
1289 offset = ((ino - 1) % EXT2_INODES_PER_GROUP(sb)) * EXT2_INODE_SIZE(sb);
1290 block = le32_to_cpu(gdp->bg_inode_table) +
1291 (offset >> EXT2_BLOCK_SIZE_BITS(sb));
1292 if (!(bh = sb_bread(sb, block)))
1293 goto Eio;
1294
1295 *p = bh;
1296 offset &= (EXT2_BLOCK_SIZE(sb) - 1);
1297 return (struct ext2_inode *) (bh->b_data + offset);
1298
1299Einval:
1300 ext2_error(sb, "ext2_get_inode", "bad inode number: %lu",
1301 (unsigned long) ino);
1302 return ERR_PTR(-EINVAL);
1303Eio:
1304 ext2_error(sb, "ext2_get_inode",
1305 "unable to read inode block - inode=%lu, block=%lu",
1306 (unsigned long) ino, block);
1307Egdp:
1308 return ERR_PTR(-EIO);
1309}
1310
1311void ext2_set_inode_flags(struct inode *inode)
1312{
1313 unsigned int flags = EXT2_I(inode)->i_flags;
1314
1315 inode->i_flags &= ~(S_SYNC | S_APPEND | S_IMMUTABLE | S_NOATIME |
1316 S_DIRSYNC);
1317 if (flags & EXT2_SYNC_FL)
1318 inode->i_flags |= S_SYNC;
1319 if (flags & EXT2_APPEND_FL)
1320 inode->i_flags |= S_APPEND;
1321 if (flags & EXT2_IMMUTABLE_FL)
1322 inode->i_flags |= S_IMMUTABLE;
1323 if (flags & EXT2_NOATIME_FL)
1324 inode->i_flags |= S_NOATIME;
1325 if (flags & EXT2_DIRSYNC_FL)
1326 inode->i_flags |= S_DIRSYNC;
1327}
1328
1329void ext2_set_file_ops(struct inode *inode)
1330{
1331 inode->i_op = &ext2_file_inode_operations;
1332 inode->i_fop = &ext2_file_operations;
1333 inode->i_mapping->a_ops = &ext2_aops;
1334}
1335
1336struct inode *ext2_iget (struct super_block *sb, unsigned long ino)
1337{
1338 struct ext2_inode_info *ei;
1339 struct buffer_head * bh = NULL;
1340 struct ext2_inode *raw_inode;
1341 struct inode *inode;
1342 long ret = -EIO;
1343 int n;
1344 uid_t i_uid;
1345 gid_t i_gid;
1346
1347 inode = iget_locked(sb, ino);
1348 if (!inode)
1349 return ERR_PTR(-ENOMEM);
1350 if (!(inode_state_read_once(inode) & I_NEW))
1351 return inode;
1352
1353 ei = EXT2_I(inode);
1354 ei->i_block_alloc_info = NULL;
1355
1356 raw_inode = ext2_get_inode(inode->i_sb, ino, &bh);
1357 if (IS_ERR(raw_inode)) {
1358 ret = PTR_ERR(raw_inode);
1359 goto bad_inode;
1360 }
1361
1362 inode->i_mode = le16_to_cpu(raw_inode->i_mode);
1363 i_uid = (uid_t)le16_to_cpu(raw_inode->i_uid_low);
1364 i_gid = (gid_t)le16_to_cpu(raw_inode->i_gid_low);
1365 if (!(test_opt (inode->i_sb, NO_UID32))) {
1366 i_uid |= le16_to_cpu(raw_inode->i_uid_high) << 16;
1367 i_gid |= le16_to_cpu(raw_inode->i_gid_high) << 16;
1368 }
1369 i_uid_write(inode, i_uid);
1370 i_gid_write(inode, i_gid);
1371 set_nlink(inode, le16_to_cpu(raw_inode->i_links_count));
1372 inode->i_size = le32_to_cpu(raw_inode->i_size);
1373 inode_set_atime(inode, (signed)le32_to_cpu(raw_inode->i_atime), 0);
1374 inode_set_ctime(inode, (signed)le32_to_cpu(raw_inode->i_ctime), 0);
1375 inode_set_mtime(inode, (signed)le32_to_cpu(raw_inode->i_mtime), 0);
1376 ei->i_dtime = le32_to_cpu(raw_inode->i_dtime);
1377 /* We now have enough fields to check if the inode was active or not.
1378 * This is needed because nfsd might try to access dead inodes
1379 * the test is that same one that e2fsck uses
1380 * NeilBrown 1999oct15
1381 */
1382 if (inode->i_nlink == 0) {
1383 if (inode->i_mode == 0 || ei->i_dtime) {
1384 /* this inode is deleted */
1385 ret = -ESTALE;
1386 } else {
1387 ext2_error(sb, __func__,
1388 "inode %lu has zero i_nlink with mode 0%o and no dtime, "
1389 "filesystem may be corrupt",
1390 ino, inode->i_mode);
1391 ret = -EFSCORRUPTED;
1392 }
1393 goto bad_inode;
1394 }
1395 inode->i_blocks = le32_to_cpu(raw_inode->i_blocks);
1396 ei->i_flags = le32_to_cpu(raw_inode->i_flags);
1397 ext2_set_inode_flags(inode);
1398 ei->i_faddr = le32_to_cpu(raw_inode->i_faddr);
1399 ei->i_frag_no = raw_inode->i_frag;
1400 ei->i_frag_size = raw_inode->i_fsize;
1401 ei->i_file_acl = le32_to_cpu(raw_inode->i_file_acl);
1402 ei->i_dir_acl = 0;
1403
1404 if (ei->i_file_acl &&
1405 !ext2_data_block_valid(EXT2_SB(sb), ei->i_file_acl, 1)) {
1406 ext2_error(sb, "ext2_iget", "bad extended attribute block %u",
1407 ei->i_file_acl);
1408 ret = -EFSCORRUPTED;
1409 goto bad_inode;
1410 }
1411
1412 if (S_ISREG(inode->i_mode))
1413 inode->i_size |= ((__u64)le32_to_cpu(raw_inode->i_size_high)) << 32;
1414 else
1415 ei->i_dir_acl = le32_to_cpu(raw_inode->i_dir_acl);
1416 if (i_size_read(inode) < 0) {
1417 ret = -EFSCORRUPTED;
1418 goto bad_inode;
1419 }
1420 ei->i_dtime = 0;
1421 inode->i_generation = le32_to_cpu(raw_inode->i_generation);
1422 ei->i_state = 0;
1423 ei->i_block_group = (ino - 1) / EXT2_INODES_PER_GROUP(inode->i_sb);
1424 ei->i_dir_start_lookup = 0;
1425
1426 /*
1427 * NOTE! The in-memory inode i_data array is in little-endian order
1428 * even on big-endian machines: we do NOT byteswap the block numbers!
1429 */
1430 for (n = 0; n < EXT2_N_BLOCKS; n++)
1431 ei->i_data[n] = raw_inode->i_block[n];
1432
1433 if (S_ISREG(inode->i_mode)) {
1434 ext2_set_file_ops(inode);
1435 } else if (S_ISDIR(inode->i_mode)) {
1436 inode->i_op = &ext2_dir_inode_operations;
1437 inode->i_fop = &ext2_dir_operations;
1438 inode->i_mapping->a_ops = &ext2_aops;
1439 } else if (S_ISLNK(inode->i_mode)) {
1440 if (ext2_inode_is_fast_symlink(inode)) {
1441 inode->i_link = (char *)ei->i_data;
1442 inode->i_op = &ext2_fast_symlink_inode_operations;
1443 nd_terminate_link(ei->i_data, inode->i_size,
1444 sizeof(ei->i_data) - 1);
1445 } else {
1446 inode->i_op = &ext2_symlink_inode_operations;
1447 inode_nohighmem(inode);
1448 inode->i_mapping->a_ops = &ext2_aops;
1449 }
1450 } else {
1451 inode->i_op = &ext2_special_inode_operations;
1452 if (raw_inode->i_block[0])
1453 init_special_inode(inode, inode->i_mode,
1454 old_decode_dev(le32_to_cpu(raw_inode->i_block[0])));
1455 else
1456 init_special_inode(inode, inode->i_mode,
1457 new_decode_dev(le32_to_cpu(raw_inode->i_block[1])));
1458 }
1459 brelse (bh);
1460 unlock_new_inode(inode);
1461 return inode;
1462
1463bad_inode:
1464 brelse(bh);
1465 iget_failed(inode);
1466 return ERR_PTR(ret);
1467}
1468
1469int ext2_write_inode(struct inode *inode, struct writeback_control *wbc)
1470{
1471 struct ext2_inode_info *ei = EXT2_I(inode);
1472 struct super_block *sb = inode->i_sb;
1473 ino_t ino = inode->i_ino;
1474 uid_t uid = i_uid_read(inode);
1475 gid_t gid = i_gid_read(inode);
1476 struct buffer_head * bh;
1477 struct ext2_inode * raw_inode = ext2_get_inode(sb, ino, &bh);
1478 int n;
1479 int err = 0;
1480
1481 if (IS_ERR(raw_inode))
1482 return -EIO;
1483
1484 /* For fields not tracking in the in-memory inode,
1485 * initialise them to zero for new inodes. */
1486 if (ei->i_state & EXT2_STATE_NEW)
1487 memset(raw_inode, 0, EXT2_SB(sb)->s_inode_size);
1488
1489 raw_inode->i_mode = cpu_to_le16(inode->i_mode);
1490 if (!(test_opt(sb, NO_UID32))) {
1491 raw_inode->i_uid_low = cpu_to_le16(low_16_bits(uid));
1492 raw_inode->i_gid_low = cpu_to_le16(low_16_bits(gid));
1493/*
1494 * Fix up interoperability with old kernels. Otherwise, old inodes get
1495 * re-used with the upper 16 bits of the uid/gid intact
1496 */
1497 if (!ei->i_dtime) {
1498 raw_inode->i_uid_high = cpu_to_le16(high_16_bits(uid));
1499 raw_inode->i_gid_high = cpu_to_le16(high_16_bits(gid));
1500 } else {
1501 raw_inode->i_uid_high = 0;
1502 raw_inode->i_gid_high = 0;
1503 }
1504 } else {
1505 raw_inode->i_uid_low = cpu_to_le16(fs_high2lowuid(uid));
1506 raw_inode->i_gid_low = cpu_to_le16(fs_high2lowgid(gid));
1507 raw_inode->i_uid_high = 0;
1508 raw_inode->i_gid_high = 0;
1509 }
1510 raw_inode->i_links_count = cpu_to_le16(inode->i_nlink);
1511 raw_inode->i_size = cpu_to_le32(inode->i_size);
1512 raw_inode->i_atime = cpu_to_le32(inode_get_atime_sec(inode));
1513 raw_inode->i_ctime = cpu_to_le32(inode_get_ctime_sec(inode));
1514 raw_inode->i_mtime = cpu_to_le32(inode_get_mtime_sec(inode));
1515
1516 raw_inode->i_blocks = cpu_to_le32(inode->i_blocks);
1517 raw_inode->i_dtime = cpu_to_le32(ei->i_dtime);
1518 raw_inode->i_flags = cpu_to_le32(ei->i_flags);
1519 raw_inode->i_faddr = cpu_to_le32(ei->i_faddr);
1520 raw_inode->i_frag = ei->i_frag_no;
1521 raw_inode->i_fsize = ei->i_frag_size;
1522 raw_inode->i_file_acl = cpu_to_le32(ei->i_file_acl);
1523 if (!S_ISREG(inode->i_mode))
1524 raw_inode->i_dir_acl = cpu_to_le32(ei->i_dir_acl);
1525 else {
1526 raw_inode->i_size_high = cpu_to_le32(inode->i_size >> 32);
1527 if (inode->i_size > 0x7fffffffULL) {
1528 if (!EXT2_HAS_RO_COMPAT_FEATURE(sb,
1529 EXT2_FEATURE_RO_COMPAT_LARGE_FILE) ||
1530 EXT2_SB(sb)->s_es->s_rev_level ==
1531 cpu_to_le32(EXT2_GOOD_OLD_REV)) {
1532 /* If this is the first large file
1533 * created, add a flag to the superblock.
1534 */
1535 spin_lock(&EXT2_SB(sb)->s_lock);
1536 ext2_update_dynamic_rev(sb);
1537 EXT2_SET_RO_COMPAT_FEATURE(sb,
1538 EXT2_FEATURE_RO_COMPAT_LARGE_FILE);
1539 spin_unlock(&EXT2_SB(sb)->s_lock);
1540 ext2_sync_super(sb, EXT2_SB(sb)->s_es, 1);
1541 }
1542 }
1543 }
1544
1545 raw_inode->i_generation = cpu_to_le32(inode->i_generation);
1546 if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) {
1547 if (old_valid_dev(inode->i_rdev)) {
1548 raw_inode->i_block[0] =
1549 cpu_to_le32(old_encode_dev(inode->i_rdev));
1550 raw_inode->i_block[1] = 0;
1551 } else {
1552 raw_inode->i_block[0] = 0;
1553 raw_inode->i_block[1] =
1554 cpu_to_le32(new_encode_dev(inode->i_rdev));
1555 raw_inode->i_block[2] = 0;
1556 }
1557 } else for (n = 0; n < EXT2_N_BLOCKS; n++)
1558 raw_inode->i_block[n] = ei->i_data[n];
1559 mark_buffer_dirty(bh);
1560 ei->i_state &= ~EXT2_STATE_NEW;
1561 brelse (bh);
1562 set_inode_metadata_writeback(inode);
1563 return err;
1564}
1565
1566int ext2_sync_inode_metadata(struct inode *inode, struct writeback_control *wbc)
1567{
1568 struct buffer_head *bh;
1569 struct ext2_inode *raw_inode = ext2_get_inode(inode->i_sb, inode->i_ino,
1570 &bh);
1571 int err = 0;
1572
1573 if (IS_ERR(raw_inode))
1574 return -EIO;
1575 err = mmb_sync(&EXT2_I(inode)->i_metadata_bhs);
1576 if (err) {
1577 ext2_error(inode->i_sb, __func__,
1578 "Error syncing inode metadata ino=%lu\n",
1579 (unsigned long)inode->i_ino);
1580 goto out;
1581 }
1582 sync_dirty_buffer(bh);
1583 if (buffer_write_io_error(bh)) {
1584 ext2_error(inode->i_sb, __func__,
1585 "IO error syncing inode %lu\n",
1586 (unsigned long)inode->i_ino);
1587 err = -EIO;
1588 }
1589out:
1590 brelse(bh);
1591 return err;
1592}
1593
1594int ext2_getattr(struct mnt_idmap *idmap, const struct path *path,
1595 struct kstat *stat, u32 request_mask, unsigned int query_flags)
1596{
1597 struct inode *inode = d_inode(path->dentry);
1598 struct ext2_inode_info *ei = EXT2_I(inode);
1599 unsigned int flags;
1600
1601 flags = ei->i_flags & EXT2_FL_USER_VISIBLE;
1602 if (flags & EXT2_APPEND_FL)
1603 stat->attributes |= STATX_ATTR_APPEND;
1604 if (flags & EXT2_COMPR_FL)
1605 stat->attributes |= STATX_ATTR_COMPRESSED;
1606 if (flags & EXT2_IMMUTABLE_FL)
1607 stat->attributes |= STATX_ATTR_IMMUTABLE;
1608 if (flags & EXT2_NODUMP_FL)
1609 stat->attributes |= STATX_ATTR_NODUMP;
1610 stat->attributes_mask |= (STATX_ATTR_APPEND |
1611 STATX_ATTR_COMPRESSED |
1612 STATX_ATTR_ENCRYPTED |
1613 STATX_ATTR_IMMUTABLE |
1614 STATX_ATTR_NODUMP);
1615
1616 generic_fillattr(&nop_mnt_idmap, request_mask, inode, stat);
1617 return 0;
1618}
1619
1620int ext2_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
1621 struct iattr *iattr)
1622{
1623 struct inode *inode = d_inode(dentry);
1624 int error;
1625
1626 error = setattr_prepare(&nop_mnt_idmap, dentry, iattr);
1627 if (error)
1628 return error;
1629
1630 if (is_quota_modification(&nop_mnt_idmap, inode, iattr)) {
1631 error = dquot_initialize(inode);
1632 if (error)
1633 return error;
1634 }
1635 if (i_uid_needs_update(&nop_mnt_idmap, iattr, inode) ||
1636 i_gid_needs_update(&nop_mnt_idmap, iattr, inode)) {
1637 error = dquot_transfer(&nop_mnt_idmap, inode, iattr);
1638 if (error)
1639 return error;
1640 }
1641 if (iattr->ia_valid & ATTR_SIZE && iattr->ia_size != inode->i_size) {
1642 error = ext2_setsize(inode, iattr->ia_size);
1643 if (error)
1644 return error;
1645 }
1646 setattr_copy(&nop_mnt_idmap, inode, iattr);
1647 if (iattr->ia_valid & ATTR_MODE)
1648 error = posix_acl_chmod(&nop_mnt_idmap, dentry, inode->i_mode);
1649 mark_inode_dirty(inode);
1650
1651 return error;
1652}