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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Copyright (C) 2012-2013 Samsung Electronics Co., Ltd.
4 */
5
6#include <linux/init.h>
7#include <linux/buffer_head.h>
8#include <linux/mpage.h>
9#include <linux/bio.h>
10#include <linux/blkdev.h>
11#include <linux/time.h>
12#include <linux/writeback.h>
13#include <linux/uio.h>
14#include <linux/random.h>
15#include <linux/iversion.h>
16
17#include "exfat_raw.h"
18#include "exfat_fs.h"
19
20int __exfat_write_inode(struct inode *inode, int sync)
21{
22 unsigned long long on_disk_size;
23 struct exfat_dentry *ep, *ep2;
24 struct exfat_entry_set_cache es;
25 struct super_block *sb = inode->i_sb;
26 struct exfat_sb_info *sbi = EXFAT_SB(sb);
27 struct exfat_inode_info *ei = EXFAT_I(inode);
28 bool is_dir = (ei->type == TYPE_DIR) ? true : false;
29
30 if (inode->i_ino == EXFAT_ROOT_INO)
31 return 0;
32
33 /*
34 * If the inode is already unlinked, there is no need for updating it.
35 */
36 if (ei->dir.dir == DIR_DELETED)
37 return 0;
38
39 if (is_dir && ei->dir.dir == sbi->root_dir && ei->entry == -1)
40 return 0;
41
42 exfat_set_volume_dirty(sb);
43
44 /* get the directory entry of given file or directory */
45 if (exfat_get_dentry_set(&es, sb, &(ei->dir), ei->entry, ES_ALL_ENTRIES))
46 return -EIO;
47 ep = exfat_get_dentry_cached(&es, ES_IDX_FILE);
48 ep2 = exfat_get_dentry_cached(&es, ES_IDX_STREAM);
49
50 ep->dentry.file.attr = cpu_to_le16(exfat_make_attr(inode));
51
52 /* set FILE_INFO structure using the acquired struct exfat_dentry */
53 exfat_set_entry_time(sbi, &ei->i_crtime,
54 &ep->dentry.file.create_tz,
55 &ep->dentry.file.create_time,
56 &ep->dentry.file.create_date,
57 &ep->dentry.file.create_time_cs);
58 exfat_set_entry_time(sbi, &inode->i_mtime,
59 &ep->dentry.file.modify_tz,
60 &ep->dentry.file.modify_time,
61 &ep->dentry.file.modify_date,
62 &ep->dentry.file.modify_time_cs);
63 exfat_set_entry_time(sbi, &inode->i_atime,
64 &ep->dentry.file.access_tz,
65 &ep->dentry.file.access_time,
66 &ep->dentry.file.access_date,
67 NULL);
68
69 /* File size should be zero if there is no cluster allocated */
70 on_disk_size = i_size_read(inode);
71
72 if (ei->start_clu == EXFAT_EOF_CLUSTER)
73 on_disk_size = 0;
74
75 ep2->dentry.stream.valid_size = cpu_to_le64(on_disk_size);
76 ep2->dentry.stream.size = ep2->dentry.stream.valid_size;
77 if (on_disk_size) {
78 ep2->dentry.stream.flags = ei->flags;
79 ep2->dentry.stream.start_clu = cpu_to_le32(ei->start_clu);
80 } else {
81 ep2->dentry.stream.flags = ALLOC_FAT_CHAIN;
82 ep2->dentry.stream.start_clu = EXFAT_FREE_CLUSTER;
83 }
84
85 exfat_update_dir_chksum_with_entry_set(&es);
86 return exfat_put_dentry_set(&es, sync);
87}
88
89int exfat_write_inode(struct inode *inode, struct writeback_control *wbc)
90{
91 int ret;
92
93 mutex_lock(&EXFAT_SB(inode->i_sb)->s_lock);
94 ret = __exfat_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL);
95 mutex_unlock(&EXFAT_SB(inode->i_sb)->s_lock);
96
97 return ret;
98}
99
100void exfat_sync_inode(struct inode *inode)
101{
102 lockdep_assert_held(&EXFAT_SB(inode->i_sb)->s_lock);
103 __exfat_write_inode(inode, 1);
104}
105
106/*
107 * Input: inode, (logical) clu_offset, target allocation area
108 * Output: errcode, cluster number
109 * *clu = (~0), if it's unable to allocate a new cluster
110 */
111static int exfat_map_cluster(struct inode *inode, unsigned int clu_offset,
112 unsigned int *clu, int create)
113{
114 int ret;
115 unsigned int last_clu;
116 struct exfat_chain new_clu;
117 struct super_block *sb = inode->i_sb;
118 struct exfat_sb_info *sbi = EXFAT_SB(sb);
119 struct exfat_inode_info *ei = EXFAT_I(inode);
120 unsigned int local_clu_offset = clu_offset;
121 unsigned int num_to_be_allocated = 0, num_clusters = 0;
122
123 if (ei->i_size_ondisk > 0)
124 num_clusters =
125 EXFAT_B_TO_CLU_ROUND_UP(ei->i_size_ondisk, sbi);
126
127 if (clu_offset >= num_clusters)
128 num_to_be_allocated = clu_offset - num_clusters + 1;
129
130 if (!create && (num_to_be_allocated > 0)) {
131 *clu = EXFAT_EOF_CLUSTER;
132 return 0;
133 }
134
135 *clu = last_clu = ei->start_clu;
136
137 if (ei->flags == ALLOC_NO_FAT_CHAIN) {
138 if (clu_offset > 0 && *clu != EXFAT_EOF_CLUSTER) {
139 last_clu += clu_offset - 1;
140
141 if (clu_offset == num_clusters)
142 *clu = EXFAT_EOF_CLUSTER;
143 else
144 *clu += clu_offset;
145 }
146 } else if (ei->type == TYPE_FILE) {
147 unsigned int fclus = 0;
148 int err = exfat_get_cluster(inode, clu_offset,
149 &fclus, clu, &last_clu, 1);
150 if (err)
151 return -EIO;
152
153 clu_offset -= fclus;
154 } else {
155 /* hint information */
156 if (clu_offset > 0 && ei->hint_bmap.off != EXFAT_EOF_CLUSTER &&
157 ei->hint_bmap.off > 0 && clu_offset >= ei->hint_bmap.off) {
158 clu_offset -= ei->hint_bmap.off;
159 /* hint_bmap.clu should be valid */
160 WARN_ON(ei->hint_bmap.clu < 2);
161 *clu = ei->hint_bmap.clu;
162 }
163
164 while (clu_offset > 0 && *clu != EXFAT_EOF_CLUSTER) {
165 last_clu = *clu;
166 if (exfat_get_next_cluster(sb, clu))
167 return -EIO;
168 clu_offset--;
169 }
170 }
171
172 if (*clu == EXFAT_EOF_CLUSTER) {
173 exfat_set_volume_dirty(sb);
174
175 new_clu.dir = (last_clu == EXFAT_EOF_CLUSTER) ?
176 EXFAT_EOF_CLUSTER : last_clu + 1;
177 new_clu.size = 0;
178 new_clu.flags = ei->flags;
179
180 /* allocate a cluster */
181 if (num_to_be_allocated < 1) {
182 /* Broken FAT (i_sze > allocated FAT) */
183 exfat_fs_error(sb, "broken FAT chain.");
184 return -EIO;
185 }
186
187 ret = exfat_alloc_cluster(inode, num_to_be_allocated, &new_clu,
188 inode_needs_sync(inode));
189 if (ret)
190 return ret;
191
192 if (new_clu.dir == EXFAT_EOF_CLUSTER ||
193 new_clu.dir == EXFAT_FREE_CLUSTER) {
194 exfat_fs_error(sb,
195 "bogus cluster new allocated (last_clu : %u, new_clu : %u)",
196 last_clu, new_clu.dir);
197 return -EIO;
198 }
199
200 /* append to the FAT chain */
201 if (last_clu == EXFAT_EOF_CLUSTER) {
202 if (new_clu.flags == ALLOC_FAT_CHAIN)
203 ei->flags = ALLOC_FAT_CHAIN;
204 ei->start_clu = new_clu.dir;
205 } else {
206 if (new_clu.flags != ei->flags) {
207 /* no-fat-chain bit is disabled,
208 * so fat-chain should be synced with
209 * alloc-bitmap
210 */
211 exfat_chain_cont_cluster(sb, ei->start_clu,
212 num_clusters);
213 ei->flags = ALLOC_FAT_CHAIN;
214 }
215 if (new_clu.flags == ALLOC_FAT_CHAIN)
216 if (exfat_ent_set(sb, last_clu, new_clu.dir))
217 return -EIO;
218 }
219
220 num_clusters += num_to_be_allocated;
221 *clu = new_clu.dir;
222
223 inode->i_blocks +=
224 num_to_be_allocated << sbi->sect_per_clus_bits;
225
226 /*
227 * Move *clu pointer along FAT chains (hole care) because the
228 * caller of this function expect *clu to be the last cluster.
229 * This only works when num_to_be_allocated >= 2,
230 * *clu = (the first cluster of the allocated chain) =>
231 * (the last cluster of ...)
232 */
233 if (ei->flags == ALLOC_NO_FAT_CHAIN) {
234 *clu += num_to_be_allocated - 1;
235 } else {
236 while (num_to_be_allocated > 1) {
237 if (exfat_get_next_cluster(sb, clu))
238 return -EIO;
239 num_to_be_allocated--;
240 }
241 }
242
243 }
244
245 /* hint information */
246 ei->hint_bmap.off = local_clu_offset;
247 ei->hint_bmap.clu = *clu;
248
249 return 0;
250}
251
252static int exfat_map_new_buffer(struct exfat_inode_info *ei,
253 struct buffer_head *bh, loff_t pos)
254{
255 if (buffer_delay(bh) && pos > ei->i_size_aligned)
256 return -EIO;
257 set_buffer_new(bh);
258
259 /*
260 * Adjust i_size_aligned if i_size_ondisk is bigger than it.
261 */
262 if (ei->i_size_ondisk > ei->i_size_aligned)
263 ei->i_size_aligned = ei->i_size_ondisk;
264 return 0;
265}
266
267static int exfat_get_block(struct inode *inode, sector_t iblock,
268 struct buffer_head *bh_result, int create)
269{
270 struct exfat_inode_info *ei = EXFAT_I(inode);
271 struct super_block *sb = inode->i_sb;
272 struct exfat_sb_info *sbi = EXFAT_SB(sb);
273 unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits;
274 int err = 0;
275 unsigned long mapped_blocks = 0;
276 unsigned int cluster, sec_offset;
277 sector_t last_block;
278 sector_t phys = 0;
279 loff_t pos;
280
281 mutex_lock(&sbi->s_lock);
282 last_block = EXFAT_B_TO_BLK_ROUND_UP(i_size_read(inode), sb);
283 if (iblock >= last_block && !create)
284 goto done;
285
286 /* Is this block already allocated? */
287 err = exfat_map_cluster(inode, iblock >> sbi->sect_per_clus_bits,
288 &cluster, create);
289 if (err) {
290 if (err != -ENOSPC)
291 exfat_fs_error_ratelimit(sb,
292 "failed to bmap (inode : %p iblock : %llu, err : %d)",
293 inode, (unsigned long long)iblock, err);
294 goto unlock_ret;
295 }
296
297 if (cluster == EXFAT_EOF_CLUSTER)
298 goto done;
299
300 /* sector offset in cluster */
301 sec_offset = iblock & (sbi->sect_per_clus - 1);
302
303 phys = exfat_cluster_to_sector(sbi, cluster) + sec_offset;
304 mapped_blocks = sbi->sect_per_clus - sec_offset;
305 max_blocks = min(mapped_blocks, max_blocks);
306
307 /* Treat newly added block / cluster */
308 if (iblock < last_block)
309 create = 0;
310
311 if (create || buffer_delay(bh_result)) {
312 pos = EXFAT_BLK_TO_B((iblock + 1), sb);
313 if (ei->i_size_ondisk < pos)
314 ei->i_size_ondisk = pos;
315 }
316
317 if (create) {
318 err = exfat_map_new_buffer(ei, bh_result, pos);
319 if (err) {
320 exfat_fs_error(sb,
321 "requested for bmap out of range(pos : (%llu) > i_size_aligned(%llu)\n",
322 pos, ei->i_size_aligned);
323 goto unlock_ret;
324 }
325 }
326
327 if (buffer_delay(bh_result))
328 clear_buffer_delay(bh_result);
329 map_bh(bh_result, sb, phys);
330done:
331 bh_result->b_size = EXFAT_BLK_TO_B(max_blocks, sb);
332unlock_ret:
333 mutex_unlock(&sbi->s_lock);
334 return err;
335}
336
337static int exfat_read_folio(struct file *file, struct folio *folio)
338{
339 return mpage_read_folio(folio, exfat_get_block);
340}
341
342static void exfat_readahead(struct readahead_control *rac)
343{
344 mpage_readahead(rac, exfat_get_block);
345}
346
347static int exfat_writepages(struct address_space *mapping,
348 struct writeback_control *wbc)
349{
350 return mpage_writepages(mapping, wbc, exfat_get_block);
351}
352
353static void exfat_write_failed(struct address_space *mapping, loff_t to)
354{
355 struct inode *inode = mapping->host;
356
357 if (to > i_size_read(inode)) {
358 truncate_pagecache(inode, i_size_read(inode));
359 inode->i_mtime = inode->i_ctime = current_time(inode);
360 exfat_truncate(inode);
361 }
362}
363
364static int exfat_write_begin(struct file *file, struct address_space *mapping,
365 loff_t pos, unsigned int len,
366 struct page **pagep, void **fsdata)
367{
368 int ret;
369
370 *pagep = NULL;
371 ret = cont_write_begin(file, mapping, pos, len, pagep, fsdata,
372 exfat_get_block,
373 &EXFAT_I(mapping->host)->i_size_ondisk);
374
375 if (ret < 0)
376 exfat_write_failed(mapping, pos+len);
377
378 return ret;
379}
380
381static int exfat_write_end(struct file *file, struct address_space *mapping,
382 loff_t pos, unsigned int len, unsigned int copied,
383 struct page *pagep, void *fsdata)
384{
385 struct inode *inode = mapping->host;
386 struct exfat_inode_info *ei = EXFAT_I(inode);
387 int err;
388
389 err = generic_write_end(file, mapping, pos, len, copied, pagep, fsdata);
390
391 if (ei->i_size_aligned < i_size_read(inode)) {
392 exfat_fs_error(inode->i_sb,
393 "invalid size(size(%llu) > aligned(%llu)\n",
394 i_size_read(inode), ei->i_size_aligned);
395 return -EIO;
396 }
397
398 if (err < len)
399 exfat_write_failed(mapping, pos+len);
400
401 if (!(err < 0) && !(ei->attr & ATTR_ARCHIVE)) {
402 inode->i_mtime = inode->i_ctime = current_time(inode);
403 ei->attr |= ATTR_ARCHIVE;
404 mark_inode_dirty(inode);
405 }
406
407 return err;
408}
409
410static ssize_t exfat_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
411{
412 struct address_space *mapping = iocb->ki_filp->f_mapping;
413 struct inode *inode = mapping->host;
414 loff_t size = iocb->ki_pos + iov_iter_count(iter);
415 int rw = iov_iter_rw(iter);
416 ssize_t ret;
417
418 if (rw == WRITE) {
419 /*
420 * FIXME: blockdev_direct_IO() doesn't use ->write_begin(),
421 * so we need to update the ->i_size_aligned to block boundary.
422 *
423 * But we must fill the remaining area or hole by nul for
424 * updating ->i_size_aligned
425 *
426 * Return 0, and fallback to normal buffered write.
427 */
428 if (EXFAT_I(inode)->i_size_aligned < size)
429 return 0;
430 }
431
432 /*
433 * Need to use the DIO_LOCKING for avoiding the race
434 * condition of exfat_get_block() and ->truncate().
435 */
436 ret = blockdev_direct_IO(iocb, inode, iter, exfat_get_block);
437 if (ret < 0 && (rw & WRITE))
438 exfat_write_failed(mapping, size);
439 return ret;
440}
441
442static sector_t exfat_aop_bmap(struct address_space *mapping, sector_t block)
443{
444 sector_t blocknr;
445
446 /* exfat_get_cluster() assumes the requested blocknr isn't truncated. */
447 down_read(&EXFAT_I(mapping->host)->truncate_lock);
448 blocknr = generic_block_bmap(mapping, block, exfat_get_block);
449 up_read(&EXFAT_I(mapping->host)->truncate_lock);
450 return blocknr;
451}
452
453/*
454 * exfat_block_truncate_page() zeroes out a mapping from file offset `from'
455 * up to the end of the block which corresponds to `from'.
456 * This is required during truncate to physically zeroout the tail end
457 * of that block so it doesn't yield old data if the file is later grown.
458 * Also, avoid causing failure from fsx for cases of "data past EOF"
459 */
460int exfat_block_truncate_page(struct inode *inode, loff_t from)
461{
462 return block_truncate_page(inode->i_mapping, from, exfat_get_block);
463}
464
465static const struct address_space_operations exfat_aops = {
466 .dirty_folio = block_dirty_folio,
467 .invalidate_folio = block_invalidate_folio,
468 .read_folio = exfat_read_folio,
469 .readahead = exfat_readahead,
470 .writepages = exfat_writepages,
471 .write_begin = exfat_write_begin,
472 .write_end = exfat_write_end,
473 .direct_IO = exfat_direct_IO,
474 .bmap = exfat_aop_bmap,
475 .migrate_folio = buffer_migrate_folio,
476};
477
478static inline unsigned long exfat_hash(loff_t i_pos)
479{
480 return hash_32(i_pos, EXFAT_HASH_BITS);
481}
482
483void exfat_hash_inode(struct inode *inode, loff_t i_pos)
484{
485 struct exfat_sb_info *sbi = EXFAT_SB(inode->i_sb);
486 struct hlist_head *head = sbi->inode_hashtable + exfat_hash(i_pos);
487
488 spin_lock(&sbi->inode_hash_lock);
489 EXFAT_I(inode)->i_pos = i_pos;
490 hlist_add_head(&EXFAT_I(inode)->i_hash_fat, head);
491 spin_unlock(&sbi->inode_hash_lock);
492}
493
494void exfat_unhash_inode(struct inode *inode)
495{
496 struct exfat_sb_info *sbi = EXFAT_SB(inode->i_sb);
497
498 spin_lock(&sbi->inode_hash_lock);
499 hlist_del_init(&EXFAT_I(inode)->i_hash_fat);
500 EXFAT_I(inode)->i_pos = 0;
501 spin_unlock(&sbi->inode_hash_lock);
502}
503
504struct inode *exfat_iget(struct super_block *sb, loff_t i_pos)
505{
506 struct exfat_sb_info *sbi = EXFAT_SB(sb);
507 struct exfat_inode_info *info;
508 struct hlist_head *head = sbi->inode_hashtable + exfat_hash(i_pos);
509 struct inode *inode = NULL;
510
511 spin_lock(&sbi->inode_hash_lock);
512 hlist_for_each_entry(info, head, i_hash_fat) {
513 WARN_ON(info->vfs_inode.i_sb != sb);
514
515 if (i_pos != info->i_pos)
516 continue;
517 inode = igrab(&info->vfs_inode);
518 if (inode)
519 break;
520 }
521 spin_unlock(&sbi->inode_hash_lock);
522 return inode;
523}
524
525/* doesn't deal with root inode */
526static int exfat_fill_inode(struct inode *inode, struct exfat_dir_entry *info)
527{
528 struct exfat_sb_info *sbi = EXFAT_SB(inode->i_sb);
529 struct exfat_inode_info *ei = EXFAT_I(inode);
530 loff_t size = info->size;
531
532 ei->dir = info->dir;
533 ei->entry = info->entry;
534 ei->attr = info->attr;
535 ei->start_clu = info->start_clu;
536 ei->flags = info->flags;
537 ei->type = info->type;
538
539 ei->version = 0;
540 ei->hint_stat.eidx = 0;
541 ei->hint_stat.clu = info->start_clu;
542 ei->hint_femp.eidx = EXFAT_HINT_NONE;
543 ei->hint_bmap.off = EXFAT_EOF_CLUSTER;
544 ei->i_pos = 0;
545
546 inode->i_uid = sbi->options.fs_uid;
547 inode->i_gid = sbi->options.fs_gid;
548 inode_inc_iversion(inode);
549 inode->i_generation = get_random_u32();
550
551 if (info->attr & ATTR_SUBDIR) { /* directory */
552 inode->i_generation &= ~1;
553 inode->i_mode = exfat_make_mode(sbi, info->attr, 0777);
554 inode->i_op = &exfat_dir_inode_operations;
555 inode->i_fop = &exfat_dir_operations;
556 set_nlink(inode, info->num_subdirs);
557 } else { /* regular file */
558 inode->i_generation |= 1;
559 inode->i_mode = exfat_make_mode(sbi, info->attr, 0777);
560 inode->i_op = &exfat_file_inode_operations;
561 inode->i_fop = &exfat_file_operations;
562 inode->i_mapping->a_ops = &exfat_aops;
563 inode->i_mapping->nrpages = 0;
564 }
565
566 i_size_write(inode, size);
567
568 /* ondisk and aligned size should be aligned with block size */
569 if (size & (inode->i_sb->s_blocksize - 1)) {
570 size |= (inode->i_sb->s_blocksize - 1);
571 size++;
572 }
573
574 ei->i_size_aligned = size;
575 ei->i_size_ondisk = size;
576
577 exfat_save_attr(inode, info->attr);
578
579 inode->i_blocks = round_up(i_size_read(inode), sbi->cluster_size) >>
580 inode->i_blkbits;
581 inode->i_mtime = info->mtime;
582 inode->i_ctime = info->mtime;
583 ei->i_crtime = info->crtime;
584 inode->i_atime = info->atime;
585
586 return 0;
587}
588
589struct inode *exfat_build_inode(struct super_block *sb,
590 struct exfat_dir_entry *info, loff_t i_pos)
591{
592 struct inode *inode;
593 int err;
594
595 inode = exfat_iget(sb, i_pos);
596 if (inode)
597 goto out;
598 inode = new_inode(sb);
599 if (!inode) {
600 inode = ERR_PTR(-ENOMEM);
601 goto out;
602 }
603 inode->i_ino = iunique(sb, EXFAT_ROOT_INO);
604 inode_set_iversion(inode, 1);
605 err = exfat_fill_inode(inode, info);
606 if (err) {
607 iput(inode);
608 inode = ERR_PTR(err);
609 goto out;
610 }
611 exfat_hash_inode(inode, i_pos);
612 insert_inode_hash(inode);
613out:
614 return inode;
615}
616
617void exfat_evict_inode(struct inode *inode)
618{
619 truncate_inode_pages(&inode->i_data, 0);
620
621 if (!inode->i_nlink) {
622 i_size_write(inode, 0);
623 mutex_lock(&EXFAT_SB(inode->i_sb)->s_lock);
624 __exfat_truncate(inode);
625 mutex_unlock(&EXFAT_SB(inode->i_sb)->s_lock);
626 }
627
628 invalidate_inode_buffers(inode);
629 clear_inode(inode);
630 exfat_cache_inval_inode(inode);
631 exfat_unhash_inode(inode);
632}