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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
20static int __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 = NULL;
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 indode 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 es = exfat_get_dentry_set(sb, &(ei->dir), ei->entry, ES_ALL_ENTRIES);
46 if (!es)
47 return -EIO;
48 ep = exfat_get_dentry_cached(es, 0);
49 ep2 = exfat_get_dentry_cached(es, 1);
50
51 ep->dentry.file.attr = cpu_to_le16(exfat_make_attr(inode));
52
53 /* set FILE_INFO structure using the acquired struct exfat_dentry */
54 exfat_set_entry_time(sbi, &ei->i_crtime,
55 &ep->dentry.file.create_tz,
56 &ep->dentry.file.create_time,
57 &ep->dentry.file.create_date,
58 &ep->dentry.file.create_time_cs);
59 exfat_set_entry_time(sbi, &inode->i_mtime,
60 &ep->dentry.file.modify_tz,
61 &ep->dentry.file.modify_time,
62 &ep->dentry.file.modify_date,
63 &ep->dentry.file.modify_time_cs);
64 exfat_set_entry_time(sbi, &inode->i_atime,
65 &ep->dentry.file.access_tz,
66 &ep->dentry.file.access_time,
67 &ep->dentry.file.access_date,
68 NULL);
69
70 /* File size should be zero if there is no cluster allocated */
71 on_disk_size = i_size_read(inode);
72
73 if (ei->start_clu == EXFAT_EOF_CLUSTER)
74 on_disk_size = 0;
75
76 ep2->dentry.stream.valid_size = cpu_to_le64(on_disk_size);
77 ep2->dentry.stream.size = ep2->dentry.stream.valid_size;
78
79 exfat_update_dir_chksum_with_entry_set(es);
80 return exfat_free_dentry_set(es, sync);
81}
82
83int exfat_write_inode(struct inode *inode, struct writeback_control *wbc)
84{
85 int ret;
86
87 mutex_lock(&EXFAT_SB(inode->i_sb)->s_lock);
88 ret = __exfat_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL);
89 mutex_unlock(&EXFAT_SB(inode->i_sb)->s_lock);
90
91 return ret;
92}
93
94void exfat_sync_inode(struct inode *inode)
95{
96 lockdep_assert_held(&EXFAT_SB(inode->i_sb)->s_lock);
97 __exfat_write_inode(inode, 1);
98}
99
100/*
101 * Input: inode, (logical) clu_offset, target allocation area
102 * Output: errcode, cluster number
103 * *clu = (~0), if it's unable to allocate a new cluster
104 */
105static int exfat_map_cluster(struct inode *inode, unsigned int clu_offset,
106 unsigned int *clu, int create)
107{
108 int ret, modified = false;
109 unsigned int last_clu;
110 struct exfat_chain new_clu;
111 struct super_block *sb = inode->i_sb;
112 struct exfat_sb_info *sbi = EXFAT_SB(sb);
113 struct exfat_inode_info *ei = EXFAT_I(inode);
114 unsigned int local_clu_offset = clu_offset;
115 unsigned int num_to_be_allocated = 0, num_clusters = 0;
116
117 ei->rwoffset = EXFAT_CLU_TO_B(clu_offset, sbi);
118
119 if (EXFAT_I(inode)->i_size_ondisk > 0)
120 num_clusters =
121 EXFAT_B_TO_CLU_ROUND_UP(EXFAT_I(inode)->i_size_ondisk,
122 sbi);
123
124 if (clu_offset >= num_clusters)
125 num_to_be_allocated = clu_offset - num_clusters + 1;
126
127 if (!create && (num_to_be_allocated > 0)) {
128 *clu = EXFAT_EOF_CLUSTER;
129 return 0;
130 }
131
132 *clu = last_clu = ei->start_clu;
133
134 if (ei->flags == ALLOC_NO_FAT_CHAIN) {
135 if (clu_offset > 0 && *clu != EXFAT_EOF_CLUSTER) {
136 last_clu += clu_offset - 1;
137
138 if (clu_offset == num_clusters)
139 *clu = EXFAT_EOF_CLUSTER;
140 else
141 *clu += clu_offset;
142 }
143 } else if (ei->type == TYPE_FILE) {
144 unsigned int fclus = 0;
145 int err = exfat_get_cluster(inode, clu_offset,
146 &fclus, clu, &last_clu, 1);
147 if (err)
148 return -EIO;
149
150 clu_offset -= fclus;
151 } else {
152 /* hint information */
153 if (clu_offset > 0 && ei->hint_bmap.off != EXFAT_EOF_CLUSTER &&
154 ei->hint_bmap.off > 0 && clu_offset >= ei->hint_bmap.off) {
155 clu_offset -= ei->hint_bmap.off;
156 /* hint_bmap.clu should be valid */
157 WARN_ON(ei->hint_bmap.clu < 2);
158 *clu = ei->hint_bmap.clu;
159 }
160
161 while (clu_offset > 0 && *clu != EXFAT_EOF_CLUSTER) {
162 last_clu = *clu;
163 if (exfat_get_next_cluster(sb, clu))
164 return -EIO;
165 clu_offset--;
166 }
167 }
168
169 if (*clu == EXFAT_EOF_CLUSTER) {
170 exfat_set_volume_dirty(sb);
171
172 new_clu.dir = (last_clu == EXFAT_EOF_CLUSTER) ?
173 EXFAT_EOF_CLUSTER : last_clu + 1;
174 new_clu.size = 0;
175 new_clu.flags = ei->flags;
176
177 /* allocate a cluster */
178 if (num_to_be_allocated < 1) {
179 /* Broken FAT (i_sze > allocated FAT) */
180 exfat_fs_error(sb, "broken FAT chain.");
181 return -EIO;
182 }
183
184 ret = exfat_alloc_cluster(inode, num_to_be_allocated, &new_clu);
185 if (ret)
186 return ret;
187
188 if (new_clu.dir == EXFAT_EOF_CLUSTER ||
189 new_clu.dir == EXFAT_FREE_CLUSTER) {
190 exfat_fs_error(sb,
191 "bogus cluster new allocated (last_clu : %u, new_clu : %u)",
192 last_clu, new_clu.dir);
193 return -EIO;
194 }
195
196 /* append to the FAT chain */
197 if (last_clu == EXFAT_EOF_CLUSTER) {
198 if (new_clu.flags == ALLOC_FAT_CHAIN)
199 ei->flags = ALLOC_FAT_CHAIN;
200 ei->start_clu = new_clu.dir;
201 modified = true;
202 } else {
203 if (new_clu.flags != ei->flags) {
204 /* no-fat-chain bit is disabled,
205 * so fat-chain should be synced with
206 * alloc-bitmap
207 */
208 exfat_chain_cont_cluster(sb, ei->start_clu,
209 num_clusters);
210 ei->flags = ALLOC_FAT_CHAIN;
211 modified = true;
212 }
213 if (new_clu.flags == ALLOC_FAT_CHAIN)
214 if (exfat_ent_set(sb, last_clu, new_clu.dir))
215 return -EIO;
216 }
217
218 num_clusters += num_to_be_allocated;
219 *clu = new_clu.dir;
220
221 if (ei->dir.dir != DIR_DELETED && modified) {
222 struct exfat_dentry *ep;
223 struct exfat_entry_set_cache *es;
224 int err;
225
226 es = exfat_get_dentry_set(sb, &(ei->dir), ei->entry,
227 ES_ALL_ENTRIES);
228 if (!es)
229 return -EIO;
230 /* get stream entry */
231 ep = exfat_get_dentry_cached(es, 1);
232
233 /* update directory entry */
234 ep->dentry.stream.flags = ei->flags;
235 ep->dentry.stream.start_clu =
236 cpu_to_le32(ei->start_clu);
237 ep->dentry.stream.valid_size =
238 cpu_to_le64(i_size_read(inode));
239 ep->dentry.stream.size =
240 ep->dentry.stream.valid_size;
241
242 exfat_update_dir_chksum_with_entry_set(es);
243 err = exfat_free_dentry_set(es, inode_needs_sync(inode));
244 if (err)
245 return err;
246 } /* end of if != DIR_DELETED */
247
248 inode->i_blocks +=
249 num_to_be_allocated << sbi->sect_per_clus_bits;
250
251 /*
252 * Move *clu pointer along FAT chains (hole care) because the
253 * caller of this function expect *clu to be the last cluster.
254 * This only works when num_to_be_allocated >= 2,
255 * *clu = (the first cluster of the allocated chain) =>
256 * (the last cluster of ...)
257 */
258 if (ei->flags == ALLOC_NO_FAT_CHAIN) {
259 *clu += num_to_be_allocated - 1;
260 } else {
261 while (num_to_be_allocated > 1) {
262 if (exfat_get_next_cluster(sb, clu))
263 return -EIO;
264 num_to_be_allocated--;
265 }
266 }
267
268 }
269
270 /* hint information */
271 ei->hint_bmap.off = local_clu_offset;
272 ei->hint_bmap.clu = *clu;
273
274 return 0;
275}
276
277static int exfat_map_new_buffer(struct exfat_inode_info *ei,
278 struct buffer_head *bh, loff_t pos)
279{
280 if (buffer_delay(bh) && pos > ei->i_size_aligned)
281 return -EIO;
282 set_buffer_new(bh);
283
284 /*
285 * Adjust i_size_aligned if i_size_ondisk is bigger than it.
286 */
287 if (ei->i_size_ondisk > ei->i_size_aligned)
288 ei->i_size_aligned = ei->i_size_ondisk;
289 return 0;
290}
291
292static int exfat_get_block(struct inode *inode, sector_t iblock,
293 struct buffer_head *bh_result, int create)
294{
295 struct exfat_inode_info *ei = EXFAT_I(inode);
296 struct super_block *sb = inode->i_sb;
297 struct exfat_sb_info *sbi = EXFAT_SB(sb);
298 unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits;
299 int err = 0;
300 unsigned long mapped_blocks = 0;
301 unsigned int cluster, sec_offset;
302 sector_t last_block;
303 sector_t phys = 0;
304 loff_t pos;
305
306 mutex_lock(&sbi->s_lock);
307 last_block = EXFAT_B_TO_BLK_ROUND_UP(i_size_read(inode), sb);
308 if (iblock >= last_block && !create)
309 goto done;
310
311 /* Is this block already allocated? */
312 err = exfat_map_cluster(inode, iblock >> sbi->sect_per_clus_bits,
313 &cluster, create);
314 if (err) {
315 if (err != -ENOSPC)
316 exfat_fs_error_ratelimit(sb,
317 "failed to bmap (inode : %p iblock : %llu, err : %d)",
318 inode, (unsigned long long)iblock, err);
319 goto unlock_ret;
320 }
321
322 if (cluster == EXFAT_EOF_CLUSTER)
323 goto done;
324
325 /* sector offset in cluster */
326 sec_offset = iblock & (sbi->sect_per_clus - 1);
327
328 phys = exfat_cluster_to_sector(sbi, cluster) + sec_offset;
329 mapped_blocks = sbi->sect_per_clus - sec_offset;
330 max_blocks = min(mapped_blocks, max_blocks);
331
332 /* Treat newly added block / cluster */
333 if (iblock < last_block)
334 create = 0;
335
336 if (create || buffer_delay(bh_result)) {
337 pos = EXFAT_BLK_TO_B((iblock + 1), sb);
338 if (ei->i_size_ondisk < pos)
339 ei->i_size_ondisk = pos;
340 }
341
342 if (create) {
343 err = exfat_map_new_buffer(ei, bh_result, pos);
344 if (err) {
345 exfat_fs_error(sb,
346 "requested for bmap out of range(pos : (%llu) > i_size_aligned(%llu)\n",
347 pos, ei->i_size_aligned);
348 goto unlock_ret;
349 }
350 }
351
352 if (buffer_delay(bh_result))
353 clear_buffer_delay(bh_result);
354 map_bh(bh_result, sb, phys);
355done:
356 bh_result->b_size = EXFAT_BLK_TO_B(max_blocks, sb);
357unlock_ret:
358 mutex_unlock(&sbi->s_lock);
359 return err;
360}
361
362static int exfat_readpage(struct file *file, struct page *page)
363{
364 return mpage_readpage(page, exfat_get_block);
365}
366
367static void exfat_readahead(struct readahead_control *rac)
368{
369 mpage_readahead(rac, exfat_get_block);
370}
371
372static int exfat_writepage(struct page *page, struct writeback_control *wbc)
373{
374 return block_write_full_page(page, exfat_get_block, wbc);
375}
376
377static int exfat_writepages(struct address_space *mapping,
378 struct writeback_control *wbc)
379{
380 return mpage_writepages(mapping, wbc, exfat_get_block);
381}
382
383static void exfat_write_failed(struct address_space *mapping, loff_t to)
384{
385 struct inode *inode = mapping->host;
386
387 if (to > i_size_read(inode)) {
388 truncate_pagecache(inode, i_size_read(inode));
389 exfat_truncate(inode, EXFAT_I(inode)->i_size_aligned);
390 }
391}
392
393static int exfat_write_begin(struct file *file, struct address_space *mapping,
394 loff_t pos, unsigned int len, unsigned int flags,
395 struct page **pagep, void **fsdata)
396{
397 int ret;
398
399 *pagep = NULL;
400 ret = cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
401 exfat_get_block,
402 &EXFAT_I(mapping->host)->i_size_ondisk);
403
404 if (ret < 0)
405 exfat_write_failed(mapping, pos+len);
406
407 return ret;
408}
409
410static int exfat_write_end(struct file *file, struct address_space *mapping,
411 loff_t pos, unsigned int len, unsigned int copied,
412 struct page *pagep, void *fsdata)
413{
414 struct inode *inode = mapping->host;
415 struct exfat_inode_info *ei = EXFAT_I(inode);
416 int err;
417
418 err = generic_write_end(file, mapping, pos, len, copied, pagep, fsdata);
419
420 if (EXFAT_I(inode)->i_size_aligned < i_size_read(inode)) {
421 exfat_fs_error(inode->i_sb,
422 "invalid size(size(%llu) > aligned(%llu)\n",
423 i_size_read(inode), EXFAT_I(inode)->i_size_aligned);
424 return -EIO;
425 }
426
427 if (err < len)
428 exfat_write_failed(mapping, pos+len);
429
430 if (!(err < 0) && !(ei->attr & ATTR_ARCHIVE)) {
431 inode->i_mtime = inode->i_ctime = current_time(inode);
432 ei->attr |= ATTR_ARCHIVE;
433 mark_inode_dirty(inode);
434 }
435
436 return err;
437}
438
439static ssize_t exfat_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
440{
441 struct address_space *mapping = iocb->ki_filp->f_mapping;
442 struct inode *inode = mapping->host;
443 loff_t size = iocb->ki_pos + iov_iter_count(iter);
444 int rw = iov_iter_rw(iter);
445 ssize_t ret;
446
447 if (rw == WRITE) {
448 /*
449 * FIXME: blockdev_direct_IO() doesn't use ->write_begin(),
450 * so we need to update the ->i_size_aligned to block boundary.
451 *
452 * But we must fill the remaining area or hole by nul for
453 * updating ->i_size_aligned
454 *
455 * Return 0, and fallback to normal buffered write.
456 */
457 if (EXFAT_I(inode)->i_size_aligned < size)
458 return 0;
459 }
460
461 /*
462 * Need to use the DIO_LOCKING for avoiding the race
463 * condition of exfat_get_block() and ->truncate().
464 */
465 ret = blockdev_direct_IO(iocb, inode, iter, exfat_get_block);
466 if (ret < 0 && (rw & WRITE))
467 exfat_write_failed(mapping, size);
468 return ret;
469}
470
471static sector_t exfat_aop_bmap(struct address_space *mapping, sector_t block)
472{
473 sector_t blocknr;
474
475 /* exfat_get_cluster() assumes the requested blocknr isn't truncated. */
476 down_read(&EXFAT_I(mapping->host)->truncate_lock);
477 blocknr = generic_block_bmap(mapping, block, exfat_get_block);
478 up_read(&EXFAT_I(mapping->host)->truncate_lock);
479 return blocknr;
480}
481
482/*
483 * exfat_block_truncate_page() zeroes out a mapping from file offset `from'
484 * up to the end of the block which corresponds to `from'.
485 * This is required during truncate to physically zeroout the tail end
486 * of that block so it doesn't yield old data if the file is later grown.
487 * Also, avoid causing failure from fsx for cases of "data past EOF"
488 */
489int exfat_block_truncate_page(struct inode *inode, loff_t from)
490{
491 return block_truncate_page(inode->i_mapping, from, exfat_get_block);
492}
493
494static const struct address_space_operations exfat_aops = {
495 .readpage = exfat_readpage,
496 .readahead = exfat_readahead,
497 .writepage = exfat_writepage,
498 .writepages = exfat_writepages,
499 .write_begin = exfat_write_begin,
500 .write_end = exfat_write_end,
501 .direct_IO = exfat_direct_IO,
502 .bmap = exfat_aop_bmap
503};
504
505static inline unsigned long exfat_hash(loff_t i_pos)
506{
507 return hash_32(i_pos, EXFAT_HASH_BITS);
508}
509
510void exfat_hash_inode(struct inode *inode, loff_t i_pos)
511{
512 struct exfat_sb_info *sbi = EXFAT_SB(inode->i_sb);
513 struct hlist_head *head = sbi->inode_hashtable + exfat_hash(i_pos);
514
515 spin_lock(&sbi->inode_hash_lock);
516 EXFAT_I(inode)->i_pos = i_pos;
517 hlist_add_head(&EXFAT_I(inode)->i_hash_fat, head);
518 spin_unlock(&sbi->inode_hash_lock);
519}
520
521void exfat_unhash_inode(struct inode *inode)
522{
523 struct exfat_sb_info *sbi = EXFAT_SB(inode->i_sb);
524
525 spin_lock(&sbi->inode_hash_lock);
526 hlist_del_init(&EXFAT_I(inode)->i_hash_fat);
527 EXFAT_I(inode)->i_pos = 0;
528 spin_unlock(&sbi->inode_hash_lock);
529}
530
531struct inode *exfat_iget(struct super_block *sb, loff_t i_pos)
532{
533 struct exfat_sb_info *sbi = EXFAT_SB(sb);
534 struct exfat_inode_info *info;
535 struct hlist_head *head = sbi->inode_hashtable + exfat_hash(i_pos);
536 struct inode *inode = NULL;
537
538 spin_lock(&sbi->inode_hash_lock);
539 hlist_for_each_entry(info, head, i_hash_fat) {
540 WARN_ON(info->vfs_inode.i_sb != sb);
541
542 if (i_pos != info->i_pos)
543 continue;
544 inode = igrab(&info->vfs_inode);
545 if (inode)
546 break;
547 }
548 spin_unlock(&sbi->inode_hash_lock);
549 return inode;
550}
551
552/* doesn't deal with root inode */
553static int exfat_fill_inode(struct inode *inode, struct exfat_dir_entry *info)
554{
555 struct exfat_sb_info *sbi = EXFAT_SB(inode->i_sb);
556 struct exfat_inode_info *ei = EXFAT_I(inode);
557 loff_t size = info->size;
558
559 memcpy(&ei->dir, &info->dir, sizeof(struct exfat_chain));
560 ei->entry = info->entry;
561 ei->attr = info->attr;
562 ei->start_clu = info->start_clu;
563 ei->flags = info->flags;
564 ei->type = info->type;
565
566 ei->version = 0;
567 ei->hint_stat.eidx = 0;
568 ei->hint_stat.clu = info->start_clu;
569 ei->hint_femp.eidx = EXFAT_HINT_NONE;
570 ei->rwoffset = 0;
571 ei->hint_bmap.off = EXFAT_EOF_CLUSTER;
572 ei->i_pos = 0;
573
574 inode->i_uid = sbi->options.fs_uid;
575 inode->i_gid = sbi->options.fs_gid;
576 inode_inc_iversion(inode);
577 inode->i_generation = prandom_u32();
578
579 if (info->attr & ATTR_SUBDIR) { /* directory */
580 inode->i_generation &= ~1;
581 inode->i_mode = exfat_make_mode(sbi, info->attr, 0777);
582 inode->i_op = &exfat_dir_inode_operations;
583 inode->i_fop = &exfat_dir_operations;
584 set_nlink(inode, info->num_subdirs);
585 } else { /* regular file */
586 inode->i_generation |= 1;
587 inode->i_mode = exfat_make_mode(sbi, info->attr, 0777);
588 inode->i_op = &exfat_file_inode_operations;
589 inode->i_fop = &exfat_file_operations;
590 inode->i_mapping->a_ops = &exfat_aops;
591 inode->i_mapping->nrpages = 0;
592 }
593
594 i_size_write(inode, size);
595
596 /* ondisk and aligned size should be aligned with block size */
597 if (size & (inode->i_sb->s_blocksize - 1)) {
598 size |= (inode->i_sb->s_blocksize - 1);
599 size++;
600 }
601
602 ei->i_size_aligned = size;
603 ei->i_size_ondisk = size;
604
605 exfat_save_attr(inode, info->attr);
606
607 inode->i_blocks = ((i_size_read(inode) + (sbi->cluster_size - 1)) &
608 ~(sbi->cluster_size - 1)) >> inode->i_blkbits;
609 inode->i_mtime = info->mtime;
610 inode->i_ctime = info->mtime;
611 ei->i_crtime = info->crtime;
612 inode->i_atime = info->atime;
613
614 return 0;
615}
616
617struct inode *exfat_build_inode(struct super_block *sb,
618 struct exfat_dir_entry *info, loff_t i_pos)
619{
620 struct inode *inode;
621 int err;
622
623 inode = exfat_iget(sb, i_pos);
624 if (inode)
625 goto out;
626 inode = new_inode(sb);
627 if (!inode) {
628 inode = ERR_PTR(-ENOMEM);
629 goto out;
630 }
631 inode->i_ino = iunique(sb, EXFAT_ROOT_INO);
632 inode_set_iversion(inode, 1);
633 err = exfat_fill_inode(inode, info);
634 if (err) {
635 iput(inode);
636 inode = ERR_PTR(err);
637 goto out;
638 }
639 exfat_hash_inode(inode, i_pos);
640 insert_inode_hash(inode);
641out:
642 return inode;
643}
644
645void exfat_evict_inode(struct inode *inode)
646{
647 truncate_inode_pages(&inode->i_data, 0);
648
649 if (!inode->i_nlink) {
650 i_size_write(inode, 0);
651 mutex_lock(&EXFAT_SB(inode->i_sb)->s_lock);
652 __exfat_truncate(inode, 0);
653 mutex_unlock(&EXFAT_SB(inode->i_sb)->s_lock);
654 }
655
656 invalidate_inode_buffers(inode);
657 clear_inode(inode);
658 exfat_cache_inval_inode(inode);
659 exfat_unhash_inode(inode);
660}