1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright (C) 2012-2013 Samsung Electronics Co., Ltd.
4 */
5
6 #include <linux/iversion.h>
7 #include <linux/namei.h>
8 #include <linux/slab.h>
9 #include <linux/buffer_head.h>
10 #include <linux/nls.h>
11
12 #include "exfat_raw.h"
13 #include "exfat_fs.h"
14
15 static inline unsigned long exfat_d_version(struct dentry *dentry)
16 {
17 return (unsigned long) dentry->d_fsdata;
18 }
19
20 static inline void exfat_d_version_set(struct dentry *dentry,
21 unsigned long version)
22 {
23 dentry->d_fsdata = (void *) version;
24 }
25
26 /*
27 * If new entry was created in the parent, it could create the 8.3 alias (the
28 * shortname of logname). So, the parent may have the negative-dentry which
29 * matches the created 8.3 alias.
30 *
31 * If it happened, the negative dentry isn't actually negative anymore. So,
32 * drop it.
33 */
34 static int exfat_d_revalidate(struct dentry *dentry, unsigned int flags)
35 {
36 int ret;
37
38 if (flags & LOOKUP_RCU)
39 return -ECHILD;
40
41 /*
42 * This is not negative dentry. Always valid.
43 *
44 * Note, rename() to existing directory entry will have ->d_inode, and
45 * will use existing name which isn't specified name by user.
46 *
47 * We may be able to drop this positive dentry here. But dropping
48 * positive dentry isn't good idea. So it's unsupported like
49 * rename("filename", "FILENAME") for now.
50 */
51 if (d_really_is_positive(dentry))
52 return 1;
53
54 /*
55 * Drop the negative dentry, in order to make sure to use the case
56 * sensitive name which is specified by user if this is for creation.
57 */
58 if (flags & (LOOKUP_CREATE | LOOKUP_RENAME_TARGET))
59 return 0;
60
61 spin_lock(&dentry->d_lock);
62 ret = inode_eq_iversion(d_inode(dentry->d_parent),
63 exfat_d_version(dentry));
64 spin_unlock(&dentry->d_lock);
65 return ret;
66 }
67
68 /* returns the length of a struct qstr, ignoring trailing dots if necessary */
69 static unsigned int exfat_striptail_len(unsigned int len, const char *name,
70 bool keep_last_dots)
71 {
72 if (!keep_last_dots) {
73 while (len && name[len - 1] == '.')
74 len--;
75 }
76 return len;
77 }
78
79 /*
80 * Compute the hash for the exfat name corresponding to the dentry. If the name
81 * is invalid, we leave the hash code unchanged so that the existing dentry can
82 * be used. The exfat fs routines will return ENOENT or EINVAL as appropriate.
83 */
84 static int exfat_d_hash(const struct dentry *dentry, struct qstr *qstr)
85 {
86 struct super_block *sb = dentry->d_sb;
87 struct nls_table *t = EXFAT_SB(sb)->nls_io;
88 const unsigned char *name = qstr->name;
89 unsigned int len = exfat_striptail_len(qstr->len, qstr->name,
90 EXFAT_SB(sb)->options.keep_last_dots);
91 unsigned long hash = init_name_hash(dentry);
92 int i, charlen;
93 wchar_t c;
94
95 for (i = 0; i < len; i += charlen) {
96 charlen = t->char2uni(&name[i], len - i, &c);
97 if (charlen < 0)
98 return charlen;
99 hash = partial_name_hash(exfat_toupper(sb, c), hash);
100 }
101
102 qstr->hash = end_name_hash(hash);
103 return 0;
104 }
105
106 static int exfat_d_cmp(const struct dentry *dentry, unsigned int len,
107 const char *str, const struct qstr *name)
108 {
109 struct super_block *sb = dentry->d_sb;
110 struct nls_table *t = EXFAT_SB(sb)->nls_io;
111 unsigned int alen = exfat_striptail_len(name->len, name->name,
112 EXFAT_SB(sb)->options.keep_last_dots);
113 unsigned int blen = exfat_striptail_len(len, str,
114 EXFAT_SB(sb)->options.keep_last_dots);
115 wchar_t c1, c2;
116 int charlen, i;
117
118 if (alen != blen)
119 return 1;
120
121 for (i = 0; i < len; i += charlen) {
122 charlen = t->char2uni(&name->name[i], alen - i, &c1);
123 if (charlen < 0)
124 return 1;
125 if (charlen != t->char2uni(&str[i], blen - i, &c2))
126 return 1;
127
128 if (exfat_toupper(sb, c1) != exfat_toupper(sb, c2))
129 return 1;
130 }
131
132 return 0;
133 }
134
135 const struct dentry_operations exfat_dentry_ops = {
136 .d_revalidate = exfat_d_revalidate,
137 .d_hash = exfat_d_hash,
138 .d_compare = exfat_d_cmp,
139 };
140
141 static int exfat_utf8_d_hash(const struct dentry *dentry, struct qstr *qstr)
142 {
143 struct super_block *sb = dentry->d_sb;
144 const unsigned char *name = qstr->name;
145 unsigned int len = exfat_striptail_len(qstr->len, qstr->name,
146 EXFAT_SB(sb)->options.keep_last_dots);
147 unsigned long hash = init_name_hash(dentry);
148 int i, charlen;
149 unicode_t u;
150
151 for (i = 0; i < len; i += charlen) {
152 charlen = utf8_to_utf32(&name[i], len - i, &u);
153 if (charlen < 0)
154 return charlen;
155
156 /*
157 * exfat_toupper() works only for code points up to the U+FFFF.
158 */
159 hash = partial_name_hash(u <= 0xFFFF ? exfat_toupper(sb, u) : u,
160 hash);
161 }
162
163 qstr->hash = end_name_hash(hash);
164 return 0;
165 }
166
167 static int exfat_utf8_d_cmp(const struct dentry *dentry, unsigned int len,
168 const char *str, const struct qstr *name)
169 {
170 struct super_block *sb = dentry->d_sb;
171 unsigned int alen = exfat_striptail_len(name->len, name->name,
172 EXFAT_SB(sb)->options.keep_last_dots);
173 unsigned int blen = exfat_striptail_len(len, str,
174 EXFAT_SB(sb)->options.keep_last_dots);
175
176 unicode_t u_a, u_b;
177 int charlen, i;
178
179 if (alen != blen)
180 return 1;
181
182 for (i = 0; i < alen; i += charlen) {
183 charlen = utf8_to_utf32(&name->name[i], alen - i, &u_a);
184 if (charlen < 0)
185 return 1;
186 if (charlen != utf8_to_utf32(&str[i], blen - i, &u_b))
187 return 1;
188
189 if (u_a <= 0xFFFF && u_b <= 0xFFFF) {
190 if (exfat_toupper(sb, u_a) != exfat_toupper(sb, u_b))
191 return 1;
192 } else {
193 if (u_a != u_b)
194 return 1;
195 }
196 }
197
198 return 0;
199 }
200
201 const struct dentry_operations exfat_utf8_dentry_ops = {
202 .d_revalidate = exfat_d_revalidate,
203 .d_hash = exfat_utf8_d_hash,
204 .d_compare = exfat_utf8_d_cmp,
205 };
206
207 /* search EMPTY CONTINUOUS "num_entries" entries */
208 static int exfat_search_empty_slot(struct super_block *sb,
209 struct exfat_hint_femp *hint_femp, struct exfat_chain *p_dir,
210 int num_entries, struct exfat_entry_set_cache *es)
211 {
212 int i, dentry, ret;
213 int dentries_per_clu;
214 struct exfat_chain clu;
215 struct exfat_sb_info *sbi = EXFAT_SB(sb);
216 int total_entries = EXFAT_CLU_TO_DEN(p_dir->size, sbi);
217
218 dentries_per_clu = sbi->dentries_per_clu;
219
220 if (hint_femp->eidx != EXFAT_HINT_NONE) {
221 dentry = hint_femp->eidx;
222
223 /*
224 * If hint_femp->count is enough, it is needed to check if
225 * there are actual empty entries.
226 * Otherwise, and if "dentry + hint_famp->count" is also equal
227 * to "p_dir->size * dentries_per_clu", it means ENOSPC.
228 */
229 if (dentry + hint_femp->count == total_entries &&
230 num_entries > hint_femp->count)
231 return -ENOSPC;
232
233 hint_femp->eidx = EXFAT_HINT_NONE;
234 exfat_chain_dup(&clu, &hint_femp->cur);
235 } else {
236 exfat_chain_dup(&clu, p_dir);
237 dentry = 0;
238 }
239
240 while (dentry + num_entries < total_entries &&
241 clu.dir != EXFAT_EOF_CLUSTER) {
242 i = dentry & (dentries_per_clu - 1);
243
244 ret = exfat_get_empty_dentry_set(es, sb, &clu, i, num_entries);
245 if (ret < 0)
246 return ret;
247 else if (ret == 0)
248 return dentry;
249
250 dentry += ret;
251 i += ret;
252
253 while (i >= dentries_per_clu) {
254 if (clu.flags == ALLOC_NO_FAT_CHAIN) {
255 if (--clu.size > 0)
256 clu.dir++;
257 else
258 clu.dir = EXFAT_EOF_CLUSTER;
259 } else {
260 if (exfat_get_next_cluster(sb, &clu.dir))
261 return -EIO;
262 }
263
264 i -= dentries_per_clu;
265 }
266 }
267
268 hint_femp->eidx = dentry;
269 hint_femp->count = 0;
270 if (dentry == total_entries || clu.dir == EXFAT_EOF_CLUSTER)
271 exfat_chain_set(&hint_femp->cur, EXFAT_EOF_CLUSTER, 0,
272 clu.flags);
273 else
274 hint_femp->cur = clu;
275
276 return -ENOSPC;
277 }
278
279 static int exfat_check_max_dentries(struct inode *inode)
280 {
281 if (EXFAT_B_TO_DEN(i_size_read(inode)) >= MAX_EXFAT_DENTRIES) {
282 /*
283 * exFAT spec allows a dir to grow up to 8388608(256MB)
284 * dentries
285 */
286 return -ENOSPC;
287 }
288 return 0;
289 }
290
291 /* find empty directory entry.
292 * if there isn't any empty slot, expand cluster chain.
293 */
294 static int exfat_find_empty_entry(struct inode *inode,
295 struct exfat_chain *p_dir, int num_entries,
296 struct exfat_entry_set_cache *es)
297 {
298 int dentry;
299 unsigned int ret, last_clu;
300 loff_t size = 0;
301 struct exfat_chain clu;
302 struct super_block *sb = inode->i_sb;
303 struct exfat_sb_info *sbi = EXFAT_SB(sb);
304 struct exfat_inode_info *ei = EXFAT_I(inode);
305 struct exfat_hint_femp hint_femp;
306
307 hint_femp.eidx = EXFAT_HINT_NONE;
308
309 if (ei->hint_femp.eidx != EXFAT_HINT_NONE) {
310 hint_femp = ei->hint_femp;
311 ei->hint_femp.eidx = EXFAT_HINT_NONE;
312 }
313
314 while ((dentry = exfat_search_empty_slot(sb, &hint_femp, p_dir,
315 num_entries, es)) < 0) {
316 if (dentry == -EIO)
317 break;
318
319 if (exfat_check_max_dentries(inode))
320 return -ENOSPC;
321
322 /*
323 * Allocate new cluster to this directory
324 */
325 if (ei->start_clu != EXFAT_EOF_CLUSTER) {
326 /* we trust p_dir->size regardless of FAT type */
327 if (exfat_find_last_cluster(sb, p_dir, &last_clu))
328 return -EIO;
329
330 exfat_chain_set(&clu, last_clu + 1, 0, p_dir->flags);
331 } else {
332 /* This directory is empty */
333 exfat_chain_set(&clu, EXFAT_EOF_CLUSTER, 0,
334 ALLOC_NO_FAT_CHAIN);
335 }
336
337 /* allocate a cluster */
338 ret = exfat_alloc_cluster(inode, 1, &clu, IS_DIRSYNC(inode));
339 if (ret)
340 return ret;
341
342 if (exfat_zeroed_cluster(inode, clu.dir))
343 return -EIO;
344
345 if (ei->start_clu == EXFAT_EOF_CLUSTER) {
346 ei->start_clu = clu.dir;
347 p_dir->dir = clu.dir;
348 }
349
350 /* append to the FAT chain */
351 if (clu.flags != p_dir->flags) {
352 /* no-fat-chain bit is disabled,
353 * so fat-chain should be synced with alloc-bitmap
354 */
355 exfat_chain_cont_cluster(sb, p_dir->dir, p_dir->size);
356 p_dir->flags = ALLOC_FAT_CHAIN;
357 hint_femp.cur.flags = ALLOC_FAT_CHAIN;
358 }
359
360 if (clu.flags == ALLOC_FAT_CHAIN)
361 if (exfat_ent_set(sb, last_clu, clu.dir))
362 return -EIO;
363
364 if (hint_femp.cur.dir == EXFAT_EOF_CLUSTER)
365 exfat_chain_set(&hint_femp.cur, clu.dir, 0, clu.flags);
366
367 hint_femp.count += sbi->dentries_per_clu;
368
369 hint_femp.cur.size++;
370 p_dir->size++;
371 size = EXFAT_CLU_TO_B(p_dir->size, sbi);
372
373 /* directory inode should be updated in here */
374 i_size_write(inode, size);
375 ei->i_size_ondisk += sbi->cluster_size;
376 ei->i_size_aligned += sbi->cluster_size;
377 ei->valid_size += sbi->cluster_size;
378 ei->flags = p_dir->flags;
379 inode->i_blocks += sbi->cluster_size >> 9;
380 }
381
382 return dentry;
383 }
384
385 /*
386 * Name Resolution Functions :
387 * Zero if it was successful; otherwise nonzero.
388 */
389 static int __exfat_resolve_path(struct inode *inode, const unsigned char *path,
390 struct exfat_chain *p_dir, struct exfat_uni_name *p_uniname,
391 int lookup)
392 {
393 int namelen;
394 int lossy = NLS_NAME_NO_LOSSY;
395 struct super_block *sb = inode->i_sb;
396 struct exfat_sb_info *sbi = EXFAT_SB(sb);
397 struct exfat_inode_info *ei = EXFAT_I(inode);
398 int pathlen = strlen(path);
399
400 /*
401 * get the length of the pathname excluding
402 * trailing periods, if any.
403 */
404 namelen = exfat_striptail_len(pathlen, path, false);
405 if (EXFAT_SB(sb)->options.keep_last_dots) {
406 /*
407 * Do not allow the creation of files with names
408 * ending with period(s).
409 */
410 if (!lookup && (namelen < pathlen))
411 return -EINVAL;
412 namelen = pathlen;
413 }
414 if (!namelen)
415 return -ENOENT;
416 if (pathlen > (MAX_NAME_LENGTH * MAX_CHARSET_SIZE))
417 return -ENAMETOOLONG;
418
419 /*
420 * strip all leading spaces :
421 * "MS windows 7" supports leading spaces.
422 * So we should skip this preprocessing for compatibility.
423 */
424
425 /* file name conversion :
426 * If lookup case, we allow bad-name for compatibility.
427 */
428 namelen = exfat_nls_to_utf16(sb, path, namelen, p_uniname,
429 &lossy);
430 if (namelen < 0)
431 return namelen; /* return error value */
432
433 if ((lossy && !lookup) || !namelen)
434 return (lossy & NLS_NAME_OVERLEN) ? -ENAMETOOLONG : -EINVAL;
435
436 exfat_chain_set(p_dir, ei->start_clu,
437 EXFAT_B_TO_CLU(i_size_read(inode), sbi), ei->flags);
438
439 return 0;
440 }
441
442 static inline int exfat_resolve_path(struct inode *inode,
443 const unsigned char *path, struct exfat_chain *dir,
444 struct exfat_uni_name *uni)
445 {
446 return __exfat_resolve_path(inode, path, dir, uni, 0);
447 }
448
449 static inline int exfat_resolve_path_for_lookup(struct inode *inode,
450 const unsigned char *path, struct exfat_chain *dir,
451 struct exfat_uni_name *uni)
452 {
453 return __exfat_resolve_path(inode, path, dir, uni, 1);
454 }
455
456 static inline loff_t exfat_make_i_pos(struct exfat_dir_entry *info)
457 {
458 return ((loff_t) info->dir.dir << 32) | (info->entry & 0xffffffff);
459 }
460
461 static int exfat_add_entry(struct inode *inode, const char *path,
462 struct exfat_chain *p_dir, unsigned int type,
463 struct exfat_dir_entry *info)
464 {
465 int ret, dentry, num_entries;
466 struct super_block *sb = inode->i_sb;
467 struct exfat_sb_info *sbi = EXFAT_SB(sb);
468 struct exfat_uni_name uniname;
469 struct exfat_chain clu;
470 struct timespec64 ts = current_time(inode);
471 struct exfat_entry_set_cache es;
472 int clu_size = 0;
473 unsigned int start_clu = EXFAT_FREE_CLUSTER;
474
475 ret = exfat_resolve_path(inode, path, p_dir, &uniname);
476 if (ret)
477 goto out;
478
479 num_entries = exfat_calc_num_entries(&uniname);
480 if (num_entries < 0) {
481 ret = num_entries;
482 goto out;
483 }
484
485 /* exfat_find_empty_entry must be called before alloc_cluster() */
486 dentry = exfat_find_empty_entry(inode, p_dir, num_entries, &es);
487 if (dentry < 0) {
488 ret = dentry; /* -EIO or -ENOSPC */
489 goto out;
490 }
491
492 if (type == TYPE_DIR && !sbi->options.zero_size_dir) {
493 ret = exfat_alloc_new_dir(inode, &clu);
494 if (ret) {
495 exfat_put_dentry_set(&es, false);
496 goto out;
497 }
498 start_clu = clu.dir;
499 clu_size = sbi->cluster_size;
500 }
501
502 /* update the directory entry */
503 /* fill the dos name directory entry information of the created file.
504 * the first cluster is not determined yet. (0)
505 */
506 exfat_init_dir_entry(&es, type, start_clu, clu_size, &ts);
507 exfat_init_ext_entry(&es, num_entries, &uniname);
508
509 ret = exfat_put_dentry_set(&es, IS_DIRSYNC(inode));
510 if (ret)
511 goto out;
512
513 info->dir = *p_dir;
514 info->entry = dentry;
515 info->flags = ALLOC_NO_FAT_CHAIN;
516 info->type = type;
517
518 if (type == TYPE_FILE) {
519 info->attr = EXFAT_ATTR_ARCHIVE;
520 info->start_clu = EXFAT_EOF_CLUSTER;
521 info->size = 0;
522 info->num_subdirs = 0;
523 } else {
524 info->attr = EXFAT_ATTR_SUBDIR;
525 if (sbi->options.zero_size_dir)
526 info->start_clu = EXFAT_EOF_CLUSTER;
527 else
528 info->start_clu = start_clu;
529 info->size = clu_size;
530 info->num_subdirs = EXFAT_MIN_SUBDIR;
531 }
532 info->valid_size = info->size;
533
534 memset(&info->crtime, 0, sizeof(info->crtime));
535 memset(&info->mtime, 0, sizeof(info->mtime));
536 memset(&info->atime, 0, sizeof(info->atime));
537 out:
538 return ret;
539 }
540
541 static int exfat_create(struct mnt_idmap *idmap, struct inode *dir,
542 struct dentry *dentry, umode_t mode, bool excl)
543 {
544 struct super_block *sb = dir->i_sb;
545 struct inode *inode;
546 struct exfat_chain cdir;
547 struct exfat_dir_entry info;
548 loff_t i_pos;
549 int err;
550 loff_t size = i_size_read(dir);
551
552 mutex_lock(&EXFAT_SB(sb)->s_lock);
553 exfat_set_volume_dirty(sb);
554 err = exfat_add_entry(dir, dentry->d_name.name, &cdir, TYPE_FILE,
555 &info);
556 if (err)
557 goto unlock;
558
559 inode_inc_iversion(dir);
560 inode_set_mtime_to_ts(dir, inode_set_ctime_current(dir));
561 if (IS_DIRSYNC(dir) && size != i_size_read(dir))
562 exfat_sync_inode(dir);
563 else
564 mark_inode_dirty(dir);
565
566 i_pos = exfat_make_i_pos(&info);
567 inode = exfat_build_inode(sb, &info, i_pos);
568 err = PTR_ERR_OR_ZERO(inode);
569 if (err)
570 goto unlock;
571
572 inode_inc_iversion(inode);
573 EXFAT_I(inode)->i_crtime = simple_inode_init_ts(inode);
574 exfat_truncate_inode_atime(inode);
575
576 /* timestamp is already written, so mark_inode_dirty() is unneeded. */
577
578 d_instantiate(dentry, inode);
579 unlock:
580 mutex_unlock(&EXFAT_SB(sb)->s_lock);
581 return err;
582 }
583
584 /* lookup a file */
585 static int exfat_find(struct inode *dir, struct qstr *qname,
586 struct exfat_dir_entry *info)
587 {
588 int ret, dentry, count;
589 struct exfat_chain cdir;
590 struct exfat_uni_name uni_name;
591 struct super_block *sb = dir->i_sb;
592 struct exfat_sb_info *sbi = EXFAT_SB(sb);
593 struct exfat_inode_info *ei = EXFAT_I(dir);
594 struct exfat_dentry *ep, *ep2;
595 struct exfat_entry_set_cache es;
596 /* for optimized dir & entry to prevent long traverse of cluster chain */
597 struct exfat_hint hint_opt;
598
599 if (qname->len == 0)
600 return -ENOENT;
601
602 /* check the validity of directory name in the given pathname */
603 ret = exfat_resolve_path_for_lookup(dir, qname->name, &cdir, &uni_name);
604 if (ret)
605 return ret;
606
607 /* check the validation of hint_stat and initialize it if required */
608 if (ei->version != (inode_peek_iversion_raw(dir) & 0xffffffff)) {
609 ei->hint_stat.clu = cdir.dir;
610 ei->hint_stat.eidx = 0;
611 ei->version = (inode_peek_iversion_raw(dir) & 0xffffffff);
612 ei->hint_femp.eidx = EXFAT_HINT_NONE;
613 }
614
615 /* search the file name for directories */
616 dentry = exfat_find_dir_entry(sb, ei, &cdir, &uni_name, &hint_opt);
617 if (dentry < 0)
618 return dentry; /* -error value */
619
620 info->dir = cdir;
621 info->entry = dentry;
622 info->num_subdirs = 0;
623
624 /* adjust cdir to the optimized value */
625 cdir.dir = hint_opt.clu;
626 if (cdir.flags & ALLOC_NO_FAT_CHAIN)
627 cdir.size -= dentry / sbi->dentries_per_clu;
628 dentry = hint_opt.eidx;
629 if (exfat_get_dentry_set(&es, sb, &cdir, dentry, ES_2_ENTRIES))
630 return -EIO;
631 ep = exfat_get_dentry_cached(&es, ES_IDX_FILE);
632 ep2 = exfat_get_dentry_cached(&es, ES_IDX_STREAM);
633
634 info->type = exfat_get_entry_type(ep);
635 info->attr = le16_to_cpu(ep->dentry.file.attr);
636 info->size = le64_to_cpu(ep2->dentry.stream.valid_size);
637 info->valid_size = le64_to_cpu(ep2->dentry.stream.valid_size);
638 info->size = le64_to_cpu(ep2->dentry.stream.size);
639 if (info->size == 0) {
640 info->flags = ALLOC_NO_FAT_CHAIN;
641 info->start_clu = EXFAT_EOF_CLUSTER;
642 } else {
643 info->flags = ep2->dentry.stream.flags;
644 info->start_clu =
645 le32_to_cpu(ep2->dentry.stream.start_clu);
646 }
647
648 exfat_get_entry_time(sbi, &info->crtime,
649 ep->dentry.file.create_tz,
650 ep->dentry.file.create_time,
651 ep->dentry.file.create_date,
652 ep->dentry.file.create_time_cs);
653 exfat_get_entry_time(sbi, &info->mtime,
654 ep->dentry.file.modify_tz,
655 ep->dentry.file.modify_time,
656 ep->dentry.file.modify_date,
657 ep->dentry.file.modify_time_cs);
658 exfat_get_entry_time(sbi, &info->atime,
659 ep->dentry.file.access_tz,
660 ep->dentry.file.access_time,
661 ep->dentry.file.access_date,
662 0);
663 exfat_put_dentry_set(&es, false);
664
665 if (ei->start_clu == EXFAT_FREE_CLUSTER) {
666 exfat_fs_error(sb,
667 "non-zero size file starts with zero cluster (size : %llu, p_dir : %u, entry : 0x%08x)",
668 i_size_read(dir), ei->dir.dir, ei->entry);
669 return -EIO;
670 }
671
672 if (info->type == TYPE_DIR) {
673 exfat_chain_set(&cdir, info->start_clu,
674 EXFAT_B_TO_CLU(info->size, sbi), info->flags);
675 count = exfat_count_dir_entries(sb, &cdir);
676 if (count < 0)
677 return -EIO;
678
679 info->num_subdirs = count + EXFAT_MIN_SUBDIR;
680 }
681 return 0;
682 }
683
684 static int exfat_d_anon_disconn(struct dentry *dentry)
685 {
686 return IS_ROOT(dentry) && (dentry->d_flags & DCACHE_DISCONNECTED);
687 }
688
689 static struct dentry *exfat_lookup(struct inode *dir, struct dentry *dentry,
690 unsigned int flags)
691 {
692 struct super_block *sb = dir->i_sb;
693 struct inode *inode;
694 struct dentry *alias;
695 struct exfat_dir_entry info;
696 int err;
697 loff_t i_pos;
698 mode_t i_mode;
699
700 mutex_lock(&EXFAT_SB(sb)->s_lock);
701 err = exfat_find(dir, &dentry->d_name, &info);
702 if (err) {
703 if (err == -ENOENT) {
704 inode = NULL;
705 goto out;
706 }
707 goto unlock;
708 }
709
710 i_pos = exfat_make_i_pos(&info);
711 inode = exfat_build_inode(sb, &info, i_pos);
712 err = PTR_ERR_OR_ZERO(inode);
713 if (err)
714 goto unlock;
715
716 i_mode = inode->i_mode;
717 alias = d_find_alias(inode);
718
719 /*
720 * Checking "alias->d_parent == dentry->d_parent" to make sure
721 * FS is not corrupted (especially double linked dir).
722 */
723 if (alias && alias->d_parent == dentry->d_parent &&
724 !exfat_d_anon_disconn(alias)) {
725
726 /*
727 * Unhashed alias is able to exist because of revalidate()
728 * called by lookup_fast. You can easily make this status
729 * by calling create and lookup concurrently
730 * In such case, we reuse an alias instead of new dentry
731 */
732 if (d_unhashed(alias)) {
733 WARN_ON(alias->d_name.hash_len !=
734 dentry->d_name.hash_len);
735 exfat_info(sb, "rehashed a dentry(%p) in read lookup",
736 alias);
737 d_drop(dentry);
738 d_rehash(alias);
739 } else if (!S_ISDIR(i_mode)) {
740 /*
741 * This inode has non anonymous-DCACHE_DISCONNECTED
742 * dentry. This means, the user did ->lookup() by an
743 * another name (longname vs 8.3 alias of it) in past.
744 *
745 * Switch to new one for reason of locality if possible.
746 */
747 d_move(alias, dentry);
748 }
749 iput(inode);
750 mutex_unlock(&EXFAT_SB(sb)->s_lock);
751 return alias;
752 }
753 dput(alias);
754 out:
755 mutex_unlock(&EXFAT_SB(sb)->s_lock);
756 if (!inode)
757 exfat_d_version_set(dentry, inode_query_iversion(dir));
758
759 return d_splice_alias(inode, dentry);
760 unlock:
761 mutex_unlock(&EXFAT_SB(sb)->s_lock);
762 return ERR_PTR(err);
763 }
764
765 /* remove an entry, BUT don't truncate */
766 static int exfat_unlink(struct inode *dir, struct dentry *dentry)
767 {
768 struct exfat_chain cdir;
769 struct super_block *sb = dir->i_sb;
770 struct inode *inode = dentry->d_inode;
771 struct exfat_inode_info *ei = EXFAT_I(inode);
772 struct exfat_entry_set_cache es;
773 int entry, err = 0;
774
775 mutex_lock(&EXFAT_SB(sb)->s_lock);
776 exfat_chain_dup(&cdir, &ei->dir);
777 entry = ei->entry;
778 if (ei->dir.dir == DIR_DELETED) {
779 exfat_err(sb, "abnormal access to deleted dentry");
780 err = -ENOENT;
781 goto unlock;
782 }
783
784 err = exfat_get_dentry_set(&es, sb, &cdir, entry, ES_ALL_ENTRIES);
785 if (err) {
786 err = -EIO;
787 goto unlock;
788 }
789
790 exfat_set_volume_dirty(sb);
791
792 /* update the directory entry */
793 exfat_remove_entries(inode, &es, ES_IDX_FILE);
794
795 err = exfat_put_dentry_set(&es, IS_DIRSYNC(inode));
796 if (err)
797 goto unlock;
798
799 /* This doesn't modify ei */
800 ei->dir.dir = DIR_DELETED;
801
802 inode_inc_iversion(dir);
803 simple_inode_init_ts(dir);
804 exfat_truncate_inode_atime(dir);
805 mark_inode_dirty(dir);
806
807 clear_nlink(inode);
808 simple_inode_init_ts(inode);
809 exfat_truncate_inode_atime(inode);
810 exfat_unhash_inode(inode);
811 exfat_d_version_set(dentry, inode_query_iversion(dir));
812 unlock:
813 mutex_unlock(&EXFAT_SB(sb)->s_lock);
814 return err;
815 }
816
817 static int exfat_mkdir(struct mnt_idmap *idmap, struct inode *dir,
818 struct dentry *dentry, umode_t mode)
819 {
820 struct super_block *sb = dir->i_sb;
821 struct inode *inode;
822 struct exfat_dir_entry info;
823 struct exfat_chain cdir;
824 loff_t i_pos;
825 int err;
826 loff_t size = i_size_read(dir);
827
828 mutex_lock(&EXFAT_SB(sb)->s_lock);
829 exfat_set_volume_dirty(sb);
830 err = exfat_add_entry(dir, dentry->d_name.name, &cdir, TYPE_DIR,
831 &info);
832 if (err)
833 goto unlock;
834
835 inode_inc_iversion(dir);
836 inode_set_mtime_to_ts(dir, inode_set_ctime_current(dir));
837 if (IS_DIRSYNC(dir) && size != i_size_read(dir))
838 exfat_sync_inode(dir);
839 else
840 mark_inode_dirty(dir);
841 inc_nlink(dir);
842
843 i_pos = exfat_make_i_pos(&info);
844 inode = exfat_build_inode(sb, &info, i_pos);
845 err = PTR_ERR_OR_ZERO(inode);
846 if (err)
847 goto unlock;
848
849 inode_inc_iversion(inode);
850 EXFAT_I(inode)->i_crtime = simple_inode_init_ts(inode);
851 exfat_truncate_inode_atime(inode);
852 /* timestamp is already written, so mark_inode_dirty() is unneeded. */
853
854 d_instantiate(dentry, inode);
855
856 unlock:
857 mutex_unlock(&EXFAT_SB(sb)->s_lock);
858 return err;
859 }
860
861 static int exfat_check_dir_empty(struct super_block *sb,
862 struct exfat_chain *p_dir)
863 {
864 int i, dentries_per_clu;
865 unsigned int type;
866 struct exfat_chain clu;
867 struct exfat_dentry *ep;
868 struct exfat_sb_info *sbi = EXFAT_SB(sb);
869 struct buffer_head *bh;
870
871 dentries_per_clu = sbi->dentries_per_clu;
872
873 if (p_dir->dir == EXFAT_EOF_CLUSTER)
874 return 0;
875
876 exfat_chain_dup(&clu, p_dir);
877
878 while (clu.dir != EXFAT_EOF_CLUSTER) {
879 for (i = 0; i < dentries_per_clu; i++) {
880 ep = exfat_get_dentry(sb, &clu, i, &bh);
881 if (!ep)
882 return -EIO;
883 type = exfat_get_entry_type(ep);
884 brelse(bh);
885 if (type == TYPE_UNUSED)
886 return 0;
887
888 if (type != TYPE_FILE && type != TYPE_DIR)
889 continue;
890
891 return -ENOTEMPTY;
892 }
893
894 if (clu.flags == ALLOC_NO_FAT_CHAIN) {
895 if (--clu.size > 0)
896 clu.dir++;
897 else
898 clu.dir = EXFAT_EOF_CLUSTER;
899 } else {
900 if (exfat_get_next_cluster(sb, &(clu.dir)))
901 return -EIO;
902 }
903 }
904
905 return 0;
906 }
907
908 static int exfat_rmdir(struct inode *dir, struct dentry *dentry)
909 {
910 struct inode *inode = dentry->d_inode;
911 struct exfat_chain cdir, clu_to_free;
912 struct super_block *sb = inode->i_sb;
913 struct exfat_sb_info *sbi = EXFAT_SB(sb);
914 struct exfat_inode_info *ei = EXFAT_I(inode);
915 struct exfat_entry_set_cache es;
916 int entry, err;
917
918 mutex_lock(&EXFAT_SB(inode->i_sb)->s_lock);
919
920 exfat_chain_dup(&cdir, &ei->dir);
921 entry = ei->entry;
922
923 if (ei->dir.dir == DIR_DELETED) {
924 exfat_err(sb, "abnormal access to deleted dentry");
925 err = -ENOENT;
926 goto unlock;
927 }
928
929 exfat_chain_set(&clu_to_free, ei->start_clu,
930 EXFAT_B_TO_CLU_ROUND_UP(i_size_read(inode), sbi), ei->flags);
931
932 err = exfat_check_dir_empty(sb, &clu_to_free);
933 if (err) {
934 if (err == -EIO)
935 exfat_err(sb, "failed to exfat_check_dir_empty : err(%d)",
936 err);
937 goto unlock;
938 }
939
940 err = exfat_get_dentry_set(&es, sb, &cdir, entry, ES_ALL_ENTRIES);
941 if (err) {
942 err = -EIO;
943 goto unlock;
944 }
945
946 exfat_set_volume_dirty(sb);
947
948 exfat_remove_entries(inode, &es, ES_IDX_FILE);
949
950 err = exfat_put_dentry_set(&es, IS_DIRSYNC(dir));
951 if (err)
952 goto unlock;
953
954 ei->dir.dir = DIR_DELETED;
955
956 inode_inc_iversion(dir);
957 simple_inode_init_ts(dir);
958 exfat_truncate_inode_atime(dir);
959 if (IS_DIRSYNC(dir))
960 exfat_sync_inode(dir);
961 else
962 mark_inode_dirty(dir);
963 drop_nlink(dir);
964
965 clear_nlink(inode);
966 simple_inode_init_ts(inode);
967 exfat_truncate_inode_atime(inode);
968 exfat_unhash_inode(inode);
969 exfat_d_version_set(dentry, inode_query_iversion(dir));
970 unlock:
971 mutex_unlock(&EXFAT_SB(inode->i_sb)->s_lock);
972 return err;
973 }
974
975 static int exfat_rename_file(struct inode *inode, struct exfat_chain *p_dir,
976 int oldentry, struct exfat_uni_name *p_uniname,
977 struct exfat_inode_info *ei)
978 {
979 int ret, num_new_entries;
980 struct exfat_dentry *epold, *epnew;
981 struct super_block *sb = inode->i_sb;
982 struct exfat_entry_set_cache old_es, new_es;
983 int sync = IS_DIRSYNC(inode);
984
985 num_new_entries = exfat_calc_num_entries(p_uniname);
986 if (num_new_entries < 0)
987 return num_new_entries;
988
989 ret = exfat_get_dentry_set(&old_es, sb, p_dir, oldentry, ES_ALL_ENTRIES);
990 if (ret) {
991 ret = -EIO;
992 return ret;
993 }
994
995 epold = exfat_get_dentry_cached(&old_es, ES_IDX_FILE);
996
997 if (old_es.num_entries < num_new_entries) {
998 int newentry;
999
1000 newentry = exfat_find_empty_entry(inode, p_dir, num_new_entries,
1001 &new_es);
1002 if (newentry < 0) {
1003 ret = newentry; /* -EIO or -ENOSPC */
1004 goto put_old_es;
1005 }
1006
1007 epnew = exfat_get_dentry_cached(&new_es, ES_IDX_FILE);
1008 *epnew = *epold;
1009 if (exfat_get_entry_type(epnew) == TYPE_FILE) {
1010 epnew->dentry.file.attr |= cpu_to_le16(EXFAT_ATTR_ARCHIVE);
1011 ei->attr |= EXFAT_ATTR_ARCHIVE;
1012 }
1013
1014 epold = exfat_get_dentry_cached(&old_es, ES_IDX_STREAM);
1015 epnew = exfat_get_dentry_cached(&new_es, ES_IDX_STREAM);
1016 *epnew = *epold;
1017
1018 exfat_init_ext_entry(&new_es, num_new_entries, p_uniname);
1019
1020 ret = exfat_put_dentry_set(&new_es, sync);
1021 if (ret)
1022 goto put_old_es;
1023
1024 exfat_remove_entries(inode, &old_es, ES_IDX_FILE);
1025 ei->dir = *p_dir;
1026 ei->entry = newentry;
1027 } else {
1028 if (exfat_get_entry_type(epold) == TYPE_FILE) {
1029 epold->dentry.file.attr |= cpu_to_le16(EXFAT_ATTR_ARCHIVE);
1030 ei->attr |= EXFAT_ATTR_ARCHIVE;
1031 }
1032
1033 exfat_remove_entries(inode, &old_es, ES_IDX_FIRST_FILENAME + 1);
1034 exfat_init_ext_entry(&old_es, num_new_entries, p_uniname);
1035 }
1036 return exfat_put_dentry_set(&old_es, sync);
1037
1038 put_old_es:
1039 exfat_put_dentry_set(&old_es, false);
1040 return ret;
1041 }
1042
1043 static int exfat_move_file(struct inode *inode, struct exfat_chain *p_olddir,
1044 int oldentry, struct exfat_chain *p_newdir,
1045 struct exfat_uni_name *p_uniname, struct exfat_inode_info *ei)
1046 {
1047 int ret, newentry, num_new_entries;
1048 struct exfat_dentry *epmov, *epnew;
1049 struct super_block *sb = inode->i_sb;
1050 struct exfat_entry_set_cache mov_es, new_es;
1051
1052 num_new_entries = exfat_calc_num_entries(p_uniname);
1053 if (num_new_entries < 0)
1054 return num_new_entries;
1055
1056 ret = exfat_get_dentry_set(&mov_es, sb, p_olddir, oldentry,
1057 ES_ALL_ENTRIES);
1058 if (ret)
1059 return -EIO;
1060
1061 newentry = exfat_find_empty_entry(inode, p_newdir, num_new_entries,
1062 &new_es);
1063 if (newentry < 0) {
1064 ret = newentry; /* -EIO or -ENOSPC */
1065 goto put_mov_es;
1066 }
1067
1068 epmov = exfat_get_dentry_cached(&mov_es, ES_IDX_FILE);
1069 epnew = exfat_get_dentry_cached(&new_es, ES_IDX_FILE);
1070 *epnew = *epmov;
1071 if (exfat_get_entry_type(epnew) == TYPE_FILE) {
1072 epnew->dentry.file.attr |= cpu_to_le16(EXFAT_ATTR_ARCHIVE);
1073 ei->attr |= EXFAT_ATTR_ARCHIVE;
1074 }
1075
1076 epmov = exfat_get_dentry_cached(&mov_es, ES_IDX_STREAM);
1077 epnew = exfat_get_dentry_cached(&new_es, ES_IDX_STREAM);
1078 *epnew = *epmov;
1079
1080 exfat_init_ext_entry(&new_es, num_new_entries, p_uniname);
1081 exfat_remove_entries(inode, &mov_es, ES_IDX_FILE);
1082
1083 exfat_chain_set(&ei->dir, p_newdir->dir, p_newdir->size,
1084 p_newdir->flags);
1085
1086 ei->entry = newentry;
1087
1088 ret = exfat_put_dentry_set(&new_es, IS_DIRSYNC(inode));
1089 if (ret)
1090 goto put_mov_es;
1091
1092 return exfat_put_dentry_set(&mov_es, IS_DIRSYNC(inode));
1093
1094 put_mov_es:
1095 exfat_put_dentry_set(&mov_es, false);
1096
1097 return ret;
1098 }
1099
1100 /* rename or move a old file into a new file */
1101 static int __exfat_rename(struct inode *old_parent_inode,
1102 struct exfat_inode_info *ei, struct inode *new_parent_inode,
1103 struct dentry *new_dentry)
1104 {
1105 int ret;
1106 int dentry;
1107 struct exfat_chain olddir, newdir;
1108 struct exfat_chain *p_dir = NULL;
1109 struct exfat_uni_name uni_name;
1110 struct exfat_dentry *ep;
1111 struct super_block *sb = old_parent_inode->i_sb;
1112 struct exfat_sb_info *sbi = EXFAT_SB(sb);
1113 const unsigned char *new_path = new_dentry->d_name.name;
1114 struct inode *new_inode = new_dentry->d_inode;
1115 struct exfat_inode_info *new_ei = NULL;
1116 unsigned int new_entry_type = TYPE_UNUSED;
1117 int new_entry = 0;
1118 struct buffer_head *new_bh = NULL;
1119
1120 /* check the validity of pointer parameters */
1121 if (new_path == NULL || strlen(new_path) == 0)
1122 return -EINVAL;
1123
1124 if (ei->dir.dir == DIR_DELETED) {
1125 exfat_err(sb, "abnormal access to deleted source dentry");
1126 return -ENOENT;
1127 }
1128
1129 exfat_chain_set(&olddir, EXFAT_I(old_parent_inode)->start_clu,
1130 EXFAT_B_TO_CLU_ROUND_UP(i_size_read(old_parent_inode), sbi),
1131 EXFAT_I(old_parent_inode)->flags);
1132 dentry = ei->entry;
1133
1134 /* check whether new dir is existing directory and empty */
1135 if (new_inode) {
1136 ret = -EIO;
1137 new_ei = EXFAT_I(new_inode);
1138
1139 if (new_ei->dir.dir == DIR_DELETED) {
1140 exfat_err(sb, "abnormal access to deleted target dentry");
1141 goto out;
1142 }
1143
1144 p_dir = &(new_ei->dir);
1145 new_entry = new_ei->entry;
1146 ep = exfat_get_dentry(sb, p_dir, new_entry, &new_bh);
1147 if (!ep)
1148 goto out;
1149
1150 new_entry_type = exfat_get_entry_type(ep);
1151 brelse(new_bh);
1152
1153 /* if new_inode exists, update ei */
1154 if (new_entry_type == TYPE_DIR) {
1155 struct exfat_chain new_clu;
1156
1157 new_clu.dir = new_ei->start_clu;
1158 new_clu.size =
1159 EXFAT_B_TO_CLU_ROUND_UP(i_size_read(new_inode),
1160 sbi);
1161 new_clu.flags = new_ei->flags;
1162
1163 ret = exfat_check_dir_empty(sb, &new_clu);
1164 if (ret)
1165 goto out;
1166 }
1167 }
1168
1169 /* check the validity of directory name in the given new pathname */
1170 ret = exfat_resolve_path(new_parent_inode, new_path, &newdir,
1171 &uni_name);
1172 if (ret)
1173 goto out;
1174
1175 exfat_set_volume_dirty(sb);
1176
1177 if (olddir.dir == newdir.dir)
1178 ret = exfat_rename_file(new_parent_inode, &olddir, dentry,
1179 &uni_name, ei);
1180 else
1181 ret = exfat_move_file(new_parent_inode, &olddir, dentry,
1182 &newdir, &uni_name, ei);
1183
1184 if (!ret && new_inode) {
1185 struct exfat_entry_set_cache es;
1186
1187 /* delete entries of new_dir */
1188 ret = exfat_get_dentry_set(&es, sb, p_dir, new_entry,
1189 ES_ALL_ENTRIES);
1190 if (ret) {
1191 ret = -EIO;
1192 goto del_out;
1193 }
1194
1195 exfat_remove_entries(new_inode, &es, ES_IDX_FILE);
1196
1197 ret = exfat_put_dentry_set(&es, IS_DIRSYNC(new_inode));
1198 if (ret)
1199 goto del_out;
1200
1201 /* Free the clusters if new_inode is a dir(as if exfat_rmdir) */
1202 if (new_entry_type == TYPE_DIR &&
1203 new_ei->start_clu != EXFAT_EOF_CLUSTER) {
1204 /* new_ei, new_clu_to_free */
1205 struct exfat_chain new_clu_to_free;
1206
1207 exfat_chain_set(&new_clu_to_free, new_ei->start_clu,
1208 EXFAT_B_TO_CLU_ROUND_UP(i_size_read(new_inode),
1209 sbi), new_ei->flags);
1210
1211 if (exfat_free_cluster(new_inode, &new_clu_to_free)) {
1212 /* just set I/O error only */
1213 ret = -EIO;
1214 }
1215
1216 i_size_write(new_inode, 0);
1217 new_ei->valid_size = 0;
1218 new_ei->start_clu = EXFAT_EOF_CLUSTER;
1219 new_ei->flags = ALLOC_NO_FAT_CHAIN;
1220 }
1221 del_out:
1222 /* Update new_inode ei
1223 * Prevent syncing removed new_inode
1224 * (new_ei is already initialized above code ("if (new_inode)")
1225 */
1226 new_ei->dir.dir = DIR_DELETED;
1227 }
1228 out:
1229 return ret;
1230 }
1231
1232 static int exfat_rename(struct mnt_idmap *idmap,
1233 struct inode *old_dir, struct dentry *old_dentry,
1234 struct inode *new_dir, struct dentry *new_dentry,
1235 unsigned int flags)
1236 {
1237 struct inode *old_inode, *new_inode;
1238 struct super_block *sb = old_dir->i_sb;
1239 loff_t i_pos;
1240 int err;
1241 loff_t size = i_size_read(new_dir);
1242
1243 /*
1244 * The VFS already checks for existence, so for local filesystems
1245 * the RENAME_NOREPLACE implementation is equivalent to plain rename.
1246 * Don't support any other flags
1247 */
1248 if (flags & ~RENAME_NOREPLACE)
1249 return -EINVAL;
1250
1251 mutex_lock(&EXFAT_SB(sb)->s_lock);
1252 old_inode = old_dentry->d_inode;
1253 new_inode = new_dentry->d_inode;
1254
1255 err = __exfat_rename(old_dir, EXFAT_I(old_inode), new_dir, new_dentry);
1256 if (err)
1257 goto unlock;
1258
1259 inode_inc_iversion(new_dir);
1260 simple_rename_timestamp(old_dir, old_dentry, new_dir, new_dentry);
1261 EXFAT_I(new_dir)->i_crtime = current_time(new_dir);
1262 exfat_truncate_inode_atime(new_dir);
1263 if (IS_DIRSYNC(new_dir) && size != i_size_read(new_dir))
1264 exfat_sync_inode(new_dir);
1265 else
1266 mark_inode_dirty(new_dir);
1267
1268 i_pos = ((loff_t)EXFAT_I(old_inode)->dir.dir << 32) |
1269 (EXFAT_I(old_inode)->entry & 0xffffffff);
1270 exfat_unhash_inode(old_inode);
1271 exfat_hash_inode(old_inode, i_pos);
1272 if (IS_DIRSYNC(new_dir))
1273 exfat_sync_inode(old_inode);
1274 else
1275 mark_inode_dirty(old_inode);
1276
1277 if (S_ISDIR(old_inode->i_mode) && old_dir != new_dir) {
1278 drop_nlink(old_dir);
1279 if (!new_inode)
1280 inc_nlink(new_dir);
1281 }
1282
1283 inode_inc_iversion(old_dir);
1284 if (new_dir != old_dir)
1285 mark_inode_dirty(old_dir);
1286
1287 if (new_inode) {
1288 exfat_unhash_inode(new_inode);
1289
1290 /* skip drop_nlink if new_inode already has been dropped */
1291 if (new_inode->i_nlink) {
1292 drop_nlink(new_inode);
1293 if (S_ISDIR(new_inode->i_mode))
1294 drop_nlink(new_inode);
1295 } else {
1296 exfat_warn(sb, "abnormal access to an inode dropped");
1297 WARN_ON(new_inode->i_nlink == 0);
1298 }
1299 EXFAT_I(new_inode)->i_crtime = current_time(new_inode);
1300 }
1301
1302 unlock:
1303 mutex_unlock(&EXFAT_SB(sb)->s_lock);
1304 return err;
1305 }
1306
1307 const struct inode_operations exfat_dir_inode_operations = {
1308 .create = exfat_create,
1309 .lookup = exfat_lookup,
1310 .unlink = exfat_unlink,
1311 .mkdir = exfat_mkdir,
1312 .rmdir = exfat_rmdir,
1313 .rename = exfat_rename,
1314 .setattr = exfat_setattr,
1315 .getattr = exfat_getattr,
1316 };
1317
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