1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright (C) 2012-2013 Samsung Electronics Co., Ltd.
4 */
5
6 #include <linux/slab.h>
7 #include <linux/bio.h>
8 #include <linux/buffer_head.h>
9
10 #include "exfat_raw.h"
11 #include "exfat_fs.h"
12
exfat_extract_uni_name(struct exfat_dentry * ep,unsigned short * uniname)13 static int exfat_extract_uni_name(struct exfat_dentry *ep,
14 unsigned short *uniname)
15 {
16 int i, len = 0;
17
18 for (i = 0; i < EXFAT_FILE_NAME_LEN; i++) {
19 *uniname = le16_to_cpu(ep->dentry.name.unicode_0_14[i]);
20 if (*uniname == 0x0)
21 return len;
22 uniname++;
23 len++;
24 }
25
26 *uniname = 0x0;
27 return len;
28
29 }
30
exfat_get_uniname_from_ext_entry(struct super_block * sb,struct exfat_chain * p_dir,int entry,unsigned short * uniname)31 static void exfat_get_uniname_from_ext_entry(struct super_block *sb,
32 struct exfat_chain *p_dir, int entry, unsigned short *uniname)
33 {
34 int i;
35 struct exfat_entry_set_cache *es;
36 unsigned int uni_len = 0, len;
37
38 es = exfat_get_dentry_set(sb, p_dir, entry, ES_ALL_ENTRIES);
39 if (!es)
40 return;
41
42 /*
43 * First entry : file entry
44 * Second entry : stream-extension entry
45 * Third entry : first file-name entry
46 * So, the index of first file-name dentry should start from 2.
47 */
48 for (i = 2; i < es->num_entries; i++) {
49 struct exfat_dentry *ep = exfat_get_dentry_cached(es, i);
50
51 /* end of name entry */
52 if (exfat_get_entry_type(ep) != TYPE_EXTEND)
53 break;
54
55 len = exfat_extract_uni_name(ep, uniname);
56 uni_len += len;
57 if (len != EXFAT_FILE_NAME_LEN || uni_len >= MAX_NAME_LENGTH)
58 break;
59 uniname += EXFAT_FILE_NAME_LEN;
60 }
61
62 exfat_free_dentry_set(es, false);
63 }
64
65 /* read a directory entry from the opened directory */
exfat_readdir(struct inode * inode,loff_t * cpos,struct exfat_dir_entry * dir_entry)66 static int exfat_readdir(struct inode *inode, loff_t *cpos, struct exfat_dir_entry *dir_entry)
67 {
68 int i, dentries_per_clu, dentries_per_clu_bits = 0, num_ext;
69 unsigned int type, clu_offset, max_dentries;
70 sector_t sector;
71 struct exfat_chain dir, clu;
72 struct exfat_uni_name uni_name;
73 struct exfat_dentry *ep;
74 struct super_block *sb = inode->i_sb;
75 struct exfat_sb_info *sbi = EXFAT_SB(sb);
76 struct exfat_inode_info *ei = EXFAT_I(inode);
77 unsigned int dentry = EXFAT_B_TO_DEN(*cpos) & 0xFFFFFFFF;
78 struct buffer_head *bh;
79
80 /* check if the given file ID is opened */
81 if (ei->type != TYPE_DIR)
82 return -EPERM;
83
84 if (ei->entry == -1)
85 exfat_chain_set(&dir, sbi->root_dir, 0, ALLOC_FAT_CHAIN);
86 else
87 exfat_chain_set(&dir, ei->start_clu,
88 EXFAT_B_TO_CLU(i_size_read(inode), sbi), ei->flags);
89
90 dentries_per_clu = sbi->dentries_per_clu;
91 dentries_per_clu_bits = ilog2(dentries_per_clu);
92 max_dentries = (unsigned int)min_t(u64, MAX_EXFAT_DENTRIES,
93 (u64)sbi->num_clusters << dentries_per_clu_bits);
94
95 clu_offset = dentry >> dentries_per_clu_bits;
96 exfat_chain_dup(&clu, &dir);
97
98 if (clu.flags == ALLOC_NO_FAT_CHAIN) {
99 clu.dir += clu_offset;
100 clu.size -= clu_offset;
101 } else {
102 /* hint_information */
103 if (clu_offset > 0 && ei->hint_bmap.off != EXFAT_EOF_CLUSTER &&
104 ei->hint_bmap.off > 0 && clu_offset >= ei->hint_bmap.off) {
105 clu_offset -= ei->hint_bmap.off;
106 clu.dir = ei->hint_bmap.clu;
107 }
108
109 while (clu_offset > 0 && clu.dir != EXFAT_EOF_CLUSTER) {
110 if (exfat_get_next_cluster(sb, &(clu.dir)))
111 return -EIO;
112
113 clu_offset--;
114 }
115 }
116
117 while (clu.dir != EXFAT_EOF_CLUSTER && dentry < max_dentries) {
118 i = dentry & (dentries_per_clu - 1);
119
120 for ( ; i < dentries_per_clu; i++, dentry++) {
121 ep = exfat_get_dentry(sb, &clu, i, &bh, §or);
122 if (!ep)
123 return -EIO;
124
125 type = exfat_get_entry_type(ep);
126 if (type == TYPE_UNUSED) {
127 brelse(bh);
128 break;
129 }
130
131 if (type != TYPE_FILE && type != TYPE_DIR) {
132 brelse(bh);
133 continue;
134 }
135
136 num_ext = ep->dentry.file.num_ext;
137 dir_entry->attr = le16_to_cpu(ep->dentry.file.attr);
138 exfat_get_entry_time(sbi, &dir_entry->crtime,
139 ep->dentry.file.create_tz,
140 ep->dentry.file.create_time,
141 ep->dentry.file.create_date,
142 ep->dentry.file.create_time_cs);
143 exfat_get_entry_time(sbi, &dir_entry->mtime,
144 ep->dentry.file.modify_tz,
145 ep->dentry.file.modify_time,
146 ep->dentry.file.modify_date,
147 ep->dentry.file.modify_time_cs);
148 exfat_get_entry_time(sbi, &dir_entry->atime,
149 ep->dentry.file.access_tz,
150 ep->dentry.file.access_time,
151 ep->dentry.file.access_date,
152 0);
153
154 *uni_name.name = 0x0;
155 exfat_get_uniname_from_ext_entry(sb, &clu, i,
156 uni_name.name);
157 exfat_utf16_to_nls(sb, &uni_name,
158 dir_entry->namebuf.lfn,
159 dir_entry->namebuf.lfnbuf_len);
160 brelse(bh);
161
162 ep = exfat_get_dentry(sb, &clu, i + 1, &bh, NULL);
163 if (!ep)
164 return -EIO;
165 dir_entry->size =
166 le64_to_cpu(ep->dentry.stream.valid_size);
167 dir_entry->entry = dentry;
168 brelse(bh);
169
170 ei->hint_bmap.off = dentry >> dentries_per_clu_bits;
171 ei->hint_bmap.clu = clu.dir;
172
173 *cpos = EXFAT_DEN_TO_B(dentry + 1 + num_ext);
174 return 0;
175 }
176
177 if (clu.flags == ALLOC_NO_FAT_CHAIN) {
178 if (--clu.size > 0)
179 clu.dir++;
180 else
181 clu.dir = EXFAT_EOF_CLUSTER;
182 } else {
183 if (exfat_get_next_cluster(sb, &(clu.dir)))
184 return -EIO;
185 }
186 }
187
188 dir_entry->namebuf.lfn[0] = '\0';
189 *cpos = EXFAT_DEN_TO_B(dentry);
190 return 0;
191 }
192
exfat_init_namebuf(struct exfat_dentry_namebuf * nb)193 static void exfat_init_namebuf(struct exfat_dentry_namebuf *nb)
194 {
195 nb->lfn = NULL;
196 nb->lfnbuf_len = 0;
197 }
198
exfat_alloc_namebuf(struct exfat_dentry_namebuf * nb)199 static int exfat_alloc_namebuf(struct exfat_dentry_namebuf *nb)
200 {
201 nb->lfn = __getname();
202 if (!nb->lfn)
203 return -ENOMEM;
204 nb->lfnbuf_len = MAX_VFSNAME_BUF_SIZE;
205 return 0;
206 }
207
exfat_free_namebuf(struct exfat_dentry_namebuf * nb)208 static void exfat_free_namebuf(struct exfat_dentry_namebuf *nb)
209 {
210 if (!nb->lfn)
211 return;
212
213 __putname(nb->lfn);
214 exfat_init_namebuf(nb);
215 }
216
217 /*
218 * Before calling dir_emit*(), sbi->s_lock should be released
219 * because page fault can occur in dir_emit*().
220 */
221 #define ITER_POS_FILLED_DOTS (2)
exfat_iterate(struct file * filp,struct dir_context * ctx)222 static int exfat_iterate(struct file *filp, struct dir_context *ctx)
223 {
224 struct inode *inode = filp->f_path.dentry->d_inode;
225 struct super_block *sb = inode->i_sb;
226 struct inode *tmp;
227 struct exfat_dir_entry de;
228 struct exfat_dentry_namebuf *nb = &(de.namebuf);
229 struct exfat_inode_info *ei = EXFAT_I(inode);
230 unsigned long inum;
231 loff_t cpos, i_pos;
232 int err = 0, fake_offset = 0;
233
234 exfat_init_namebuf(nb);
235
236 cpos = ctx->pos;
237 if (!dir_emit_dots(filp, ctx))
238 goto out;
239
240 if (ctx->pos == ITER_POS_FILLED_DOTS) {
241 cpos = 0;
242 fake_offset = 1;
243 }
244
245 cpos = round_up(cpos, DENTRY_SIZE);
246
247 /* name buffer should be allocated before use */
248 err = exfat_alloc_namebuf(nb);
249 if (err)
250 goto out;
251 get_new:
252 mutex_lock(&EXFAT_SB(sb)->s_lock);
253
254 if (ei->flags == ALLOC_NO_FAT_CHAIN && cpos >= i_size_read(inode))
255 goto end_of_dir;
256
257 err = exfat_readdir(inode, &cpos, &de);
258 if (err) {
259 /*
260 * At least we tried to read a sector.
261 * Move cpos to next sector position (should be aligned).
262 */
263 if (err == -EIO) {
264 cpos += 1 << (sb->s_blocksize_bits);
265 cpos &= ~(sb->s_blocksize - 1);
266 }
267
268 err = -EIO;
269 goto end_of_dir;
270 }
271
272 if (!nb->lfn[0])
273 goto end_of_dir;
274
275 i_pos = ((loff_t)ei->start_clu << 32) | (de.entry & 0xffffffff);
276 tmp = exfat_iget(sb, i_pos);
277 if (tmp) {
278 inum = tmp->i_ino;
279 iput(tmp);
280 } else {
281 inum = iunique(sb, EXFAT_ROOT_INO);
282 }
283
284 mutex_unlock(&EXFAT_SB(sb)->s_lock);
285 if (!dir_emit(ctx, nb->lfn, strlen(nb->lfn), inum,
286 (de.attr & ATTR_SUBDIR) ? DT_DIR : DT_REG))
287 goto out;
288 ctx->pos = cpos;
289 goto get_new;
290
291 end_of_dir:
292 if (!cpos && fake_offset)
293 cpos = ITER_POS_FILLED_DOTS;
294 ctx->pos = cpos;
295 mutex_unlock(&EXFAT_SB(sb)->s_lock);
296 out:
297 /*
298 * To improve performance, free namebuf after unlock sb_lock.
299 * If namebuf is not allocated, this function do nothing
300 */
301 exfat_free_namebuf(nb);
302 return err;
303 }
304
305 const struct file_operations exfat_dir_operations = {
306 .llseek = generic_file_llseek,
307 .read = generic_read_dir,
308 .iterate = exfat_iterate,
309 .fsync = exfat_file_fsync,
310 };
311
exfat_alloc_new_dir(struct inode * inode,struct exfat_chain * clu)312 int exfat_alloc_new_dir(struct inode *inode, struct exfat_chain *clu)
313 {
314 int ret;
315
316 exfat_chain_set(clu, EXFAT_EOF_CLUSTER, 0, ALLOC_NO_FAT_CHAIN);
317
318 ret = exfat_alloc_cluster(inode, 1, clu, IS_DIRSYNC(inode));
319 if (ret)
320 return ret;
321
322 return exfat_zeroed_cluster(inode, clu->dir);
323 }
324
exfat_calc_num_entries(struct exfat_uni_name * p_uniname)325 int exfat_calc_num_entries(struct exfat_uni_name *p_uniname)
326 {
327 int len;
328
329 len = p_uniname->name_len;
330 if (len == 0)
331 return -EINVAL;
332
333 /* 1 file entry + 1 stream entry + name entries */
334 return ((len - 1) / EXFAT_FILE_NAME_LEN + 3);
335 }
336
exfat_get_entry_type(struct exfat_dentry * ep)337 unsigned int exfat_get_entry_type(struct exfat_dentry *ep)
338 {
339 if (ep->type == EXFAT_UNUSED)
340 return TYPE_UNUSED;
341 if (IS_EXFAT_DELETED(ep->type))
342 return TYPE_DELETED;
343 if (ep->type == EXFAT_INVAL)
344 return TYPE_INVALID;
345 if (IS_EXFAT_CRITICAL_PRI(ep->type)) {
346 if (ep->type == EXFAT_BITMAP)
347 return TYPE_BITMAP;
348 if (ep->type == EXFAT_UPCASE)
349 return TYPE_UPCASE;
350 if (ep->type == EXFAT_VOLUME)
351 return TYPE_VOLUME;
352 if (ep->type == EXFAT_FILE) {
353 if (le16_to_cpu(ep->dentry.file.attr) & ATTR_SUBDIR)
354 return TYPE_DIR;
355 return TYPE_FILE;
356 }
357 return TYPE_CRITICAL_PRI;
358 }
359 if (IS_EXFAT_BENIGN_PRI(ep->type)) {
360 if (ep->type == EXFAT_GUID)
361 return TYPE_GUID;
362 if (ep->type == EXFAT_PADDING)
363 return TYPE_PADDING;
364 if (ep->type == EXFAT_ACLTAB)
365 return TYPE_ACLTAB;
366 return TYPE_BENIGN_PRI;
367 }
368 if (IS_EXFAT_CRITICAL_SEC(ep->type)) {
369 if (ep->type == EXFAT_STREAM)
370 return TYPE_STREAM;
371 if (ep->type == EXFAT_NAME)
372 return TYPE_EXTEND;
373 if (ep->type == EXFAT_ACL)
374 return TYPE_ACL;
375 return TYPE_CRITICAL_SEC;
376 }
377 return TYPE_BENIGN_SEC;
378 }
379
exfat_set_entry_type(struct exfat_dentry * ep,unsigned int type)380 static void exfat_set_entry_type(struct exfat_dentry *ep, unsigned int type)
381 {
382 if (type == TYPE_UNUSED) {
383 ep->type = EXFAT_UNUSED;
384 } else if (type == TYPE_DELETED) {
385 ep->type &= EXFAT_DELETE;
386 } else if (type == TYPE_STREAM) {
387 ep->type = EXFAT_STREAM;
388 } else if (type == TYPE_EXTEND) {
389 ep->type = EXFAT_NAME;
390 } else if (type == TYPE_BITMAP) {
391 ep->type = EXFAT_BITMAP;
392 } else if (type == TYPE_UPCASE) {
393 ep->type = EXFAT_UPCASE;
394 } else if (type == TYPE_VOLUME) {
395 ep->type = EXFAT_VOLUME;
396 } else if (type == TYPE_DIR) {
397 ep->type = EXFAT_FILE;
398 ep->dentry.file.attr = cpu_to_le16(ATTR_SUBDIR);
399 } else if (type == TYPE_FILE) {
400 ep->type = EXFAT_FILE;
401 ep->dentry.file.attr = cpu_to_le16(ATTR_ARCHIVE);
402 }
403 }
404
exfat_init_stream_entry(struct exfat_dentry * ep,unsigned char flags,unsigned int start_clu,unsigned long long size)405 static void exfat_init_stream_entry(struct exfat_dentry *ep,
406 unsigned char flags, unsigned int start_clu,
407 unsigned long long size)
408 {
409 exfat_set_entry_type(ep, TYPE_STREAM);
410 ep->dentry.stream.flags = flags;
411 ep->dentry.stream.start_clu = cpu_to_le32(start_clu);
412 ep->dentry.stream.valid_size = cpu_to_le64(size);
413 ep->dentry.stream.size = cpu_to_le64(size);
414 }
415
exfat_init_name_entry(struct exfat_dentry * ep,unsigned short * uniname)416 static void exfat_init_name_entry(struct exfat_dentry *ep,
417 unsigned short *uniname)
418 {
419 int i;
420
421 exfat_set_entry_type(ep, TYPE_EXTEND);
422 ep->dentry.name.flags = 0x0;
423
424 for (i = 0; i < EXFAT_FILE_NAME_LEN; i++) {
425 if (*uniname != 0x0) {
426 ep->dentry.name.unicode_0_14[i] = cpu_to_le16(*uniname);
427 uniname++;
428 } else {
429 ep->dentry.name.unicode_0_14[i] = 0x0;
430 }
431 }
432 }
433
exfat_init_dir_entry(struct inode * inode,struct exfat_chain * p_dir,int entry,unsigned int type,unsigned int start_clu,unsigned long long size)434 int exfat_init_dir_entry(struct inode *inode, struct exfat_chain *p_dir,
435 int entry, unsigned int type, unsigned int start_clu,
436 unsigned long long size)
437 {
438 struct super_block *sb = inode->i_sb;
439 struct exfat_sb_info *sbi = EXFAT_SB(sb);
440 struct timespec64 ts = current_time(inode);
441 sector_t sector;
442 struct exfat_dentry *ep;
443 struct buffer_head *bh;
444
445 /*
446 * We cannot use exfat_get_dentry_set here because file ep is not
447 * initialized yet.
448 */
449 ep = exfat_get_dentry(sb, p_dir, entry, &bh, §or);
450 if (!ep)
451 return -EIO;
452
453 exfat_set_entry_type(ep, type);
454 exfat_set_entry_time(sbi, &ts,
455 &ep->dentry.file.create_tz,
456 &ep->dentry.file.create_time,
457 &ep->dentry.file.create_date,
458 &ep->dentry.file.create_time_cs);
459 exfat_set_entry_time(sbi, &ts,
460 &ep->dentry.file.modify_tz,
461 &ep->dentry.file.modify_time,
462 &ep->dentry.file.modify_date,
463 &ep->dentry.file.modify_time_cs);
464 exfat_set_entry_time(sbi, &ts,
465 &ep->dentry.file.access_tz,
466 &ep->dentry.file.access_time,
467 &ep->dentry.file.access_date,
468 NULL);
469
470 exfat_update_bh(bh, IS_DIRSYNC(inode));
471 brelse(bh);
472
473 ep = exfat_get_dentry(sb, p_dir, entry + 1, &bh, §or);
474 if (!ep)
475 return -EIO;
476
477 exfat_init_stream_entry(ep,
478 (type == TYPE_FILE) ? ALLOC_FAT_CHAIN : ALLOC_NO_FAT_CHAIN,
479 start_clu, size);
480 exfat_update_bh(bh, IS_DIRSYNC(inode));
481 brelse(bh);
482
483 return 0;
484 }
485
exfat_update_dir_chksum(struct inode * inode,struct exfat_chain * p_dir,int entry)486 int exfat_update_dir_chksum(struct inode *inode, struct exfat_chain *p_dir,
487 int entry)
488 {
489 struct super_block *sb = inode->i_sb;
490 int ret = 0;
491 int i, num_entries;
492 sector_t sector;
493 u16 chksum;
494 struct exfat_dentry *ep, *fep;
495 struct buffer_head *fbh, *bh;
496
497 fep = exfat_get_dentry(sb, p_dir, entry, &fbh, §or);
498 if (!fep)
499 return -EIO;
500
501 num_entries = fep->dentry.file.num_ext + 1;
502 chksum = exfat_calc_chksum16(fep, DENTRY_SIZE, 0, CS_DIR_ENTRY);
503
504 for (i = 1; i < num_entries; i++) {
505 ep = exfat_get_dentry(sb, p_dir, entry + i, &bh, NULL);
506 if (!ep) {
507 ret = -EIO;
508 goto release_fbh;
509 }
510 chksum = exfat_calc_chksum16(ep, DENTRY_SIZE, chksum,
511 CS_DEFAULT);
512 brelse(bh);
513 }
514
515 fep->dentry.file.checksum = cpu_to_le16(chksum);
516 exfat_update_bh(fbh, IS_DIRSYNC(inode));
517 release_fbh:
518 brelse(fbh);
519 return ret;
520 }
521
exfat_init_ext_entry(struct inode * inode,struct exfat_chain * p_dir,int entry,int num_entries,struct exfat_uni_name * p_uniname)522 int exfat_init_ext_entry(struct inode *inode, struct exfat_chain *p_dir,
523 int entry, int num_entries, struct exfat_uni_name *p_uniname)
524 {
525 struct super_block *sb = inode->i_sb;
526 int i;
527 sector_t sector;
528 unsigned short *uniname = p_uniname->name;
529 struct exfat_dentry *ep;
530 struct buffer_head *bh;
531 int sync = IS_DIRSYNC(inode);
532
533 ep = exfat_get_dentry(sb, p_dir, entry, &bh, §or);
534 if (!ep)
535 return -EIO;
536
537 ep->dentry.file.num_ext = (unsigned char)(num_entries - 1);
538 exfat_update_bh(bh, sync);
539 brelse(bh);
540
541 ep = exfat_get_dentry(sb, p_dir, entry + 1, &bh, §or);
542 if (!ep)
543 return -EIO;
544
545 ep->dentry.stream.name_len = p_uniname->name_len;
546 ep->dentry.stream.name_hash = cpu_to_le16(p_uniname->name_hash);
547 exfat_update_bh(bh, sync);
548 brelse(bh);
549
550 for (i = EXFAT_FIRST_CLUSTER; i < num_entries; i++) {
551 ep = exfat_get_dentry(sb, p_dir, entry + i, &bh, §or);
552 if (!ep)
553 return -EIO;
554
555 exfat_init_name_entry(ep, uniname);
556 exfat_update_bh(bh, sync);
557 brelse(bh);
558 uniname += EXFAT_FILE_NAME_LEN;
559 }
560
561 exfat_update_dir_chksum(inode, p_dir, entry);
562 return 0;
563 }
564
exfat_remove_entries(struct inode * inode,struct exfat_chain * p_dir,int entry,int order,int num_entries)565 int exfat_remove_entries(struct inode *inode, struct exfat_chain *p_dir,
566 int entry, int order, int num_entries)
567 {
568 struct super_block *sb = inode->i_sb;
569 int i;
570 sector_t sector;
571 struct exfat_dentry *ep;
572 struct buffer_head *bh;
573
574 for (i = order; i < num_entries; i++) {
575 ep = exfat_get_dentry(sb, p_dir, entry + i, &bh, §or);
576 if (!ep)
577 return -EIO;
578
579 exfat_set_entry_type(ep, TYPE_DELETED);
580 exfat_update_bh(bh, IS_DIRSYNC(inode));
581 brelse(bh);
582 }
583
584 return 0;
585 }
586
exfat_update_dir_chksum_with_entry_set(struct exfat_entry_set_cache * es)587 void exfat_update_dir_chksum_with_entry_set(struct exfat_entry_set_cache *es)
588 {
589 int chksum_type = CS_DIR_ENTRY, i;
590 unsigned short chksum = 0;
591 struct exfat_dentry *ep;
592
593 for (i = 0; i < es->num_entries; i++) {
594 ep = exfat_get_dentry_cached(es, i);
595 chksum = exfat_calc_chksum16(ep, DENTRY_SIZE, chksum,
596 chksum_type);
597 chksum_type = CS_DEFAULT;
598 }
599 ep = exfat_get_dentry_cached(es, 0);
600 ep->dentry.file.checksum = cpu_to_le16(chksum);
601 es->modified = true;
602 }
603
exfat_free_dentry_set(struct exfat_entry_set_cache * es,int sync)604 int exfat_free_dentry_set(struct exfat_entry_set_cache *es, int sync)
605 {
606 int i, err = 0;
607
608 if (es->modified)
609 err = exfat_update_bhs(es->bh, es->num_bh, sync);
610
611 for (i = 0; i < es->num_bh; i++)
612 if (err)
613 bforget(es->bh[i]);
614 else
615 brelse(es->bh[i]);
616
617 if (IS_DYNAMIC_ES(es))
618 kfree(es->bh);
619
620 kfree(es);
621 return err;
622 }
623
exfat_walk_fat_chain(struct super_block * sb,struct exfat_chain * p_dir,unsigned int byte_offset,unsigned int * clu)624 static int exfat_walk_fat_chain(struct super_block *sb,
625 struct exfat_chain *p_dir, unsigned int byte_offset,
626 unsigned int *clu)
627 {
628 struct exfat_sb_info *sbi = EXFAT_SB(sb);
629 unsigned int clu_offset;
630 unsigned int cur_clu;
631
632 clu_offset = EXFAT_B_TO_CLU(byte_offset, sbi);
633 cur_clu = p_dir->dir;
634
635 if (p_dir->flags == ALLOC_NO_FAT_CHAIN) {
636 cur_clu += clu_offset;
637 } else {
638 while (clu_offset > 0) {
639 if (exfat_get_next_cluster(sb, &cur_clu))
640 return -EIO;
641 if (cur_clu == EXFAT_EOF_CLUSTER) {
642 exfat_fs_error(sb,
643 "invalid dentry access beyond EOF (clu : %u, eidx : %d)",
644 p_dir->dir,
645 EXFAT_B_TO_DEN(byte_offset));
646 return -EIO;
647 }
648 clu_offset--;
649 }
650 }
651
652 *clu = cur_clu;
653 return 0;
654 }
655
exfat_find_location(struct super_block * sb,struct exfat_chain * p_dir,int entry,sector_t * sector,int * offset)656 int exfat_find_location(struct super_block *sb, struct exfat_chain *p_dir,
657 int entry, sector_t *sector, int *offset)
658 {
659 int ret;
660 unsigned int off, clu = 0;
661 struct exfat_sb_info *sbi = EXFAT_SB(sb);
662
663 off = EXFAT_DEN_TO_B(entry);
664
665 ret = exfat_walk_fat_chain(sb, p_dir, off, &clu);
666 if (ret)
667 return ret;
668
669 /* byte offset in cluster */
670 off = EXFAT_CLU_OFFSET(off, sbi);
671
672 /* byte offset in sector */
673 *offset = EXFAT_BLK_OFFSET(off, sb);
674
675 /* sector offset in cluster */
676 *sector = EXFAT_B_TO_BLK(off, sb);
677 *sector += exfat_cluster_to_sector(sbi, clu);
678 return 0;
679 }
680
681 #define EXFAT_MAX_RA_SIZE (128*1024)
exfat_dir_readahead(struct super_block * sb,sector_t sec)682 static int exfat_dir_readahead(struct super_block *sb, sector_t sec)
683 {
684 struct exfat_sb_info *sbi = EXFAT_SB(sb);
685 struct buffer_head *bh;
686 unsigned int max_ra_count = EXFAT_MAX_RA_SIZE >> sb->s_blocksize_bits;
687 unsigned int page_ra_count = PAGE_SIZE >> sb->s_blocksize_bits;
688 unsigned int adj_ra_count = max(sbi->sect_per_clus, page_ra_count);
689 unsigned int ra_count = min(adj_ra_count, max_ra_count);
690
691 /* Read-ahead is not required */
692 if (sbi->sect_per_clus == 1)
693 return 0;
694
695 if (sec < sbi->data_start_sector) {
696 exfat_err(sb, "requested sector is invalid(sect:%llu, root:%llu)",
697 (unsigned long long)sec, sbi->data_start_sector);
698 return -EIO;
699 }
700
701 /* Not sector aligned with ra_count, resize ra_count to page size */
702 if ((sec - sbi->data_start_sector) & (ra_count - 1))
703 ra_count = page_ra_count;
704
705 bh = sb_find_get_block(sb, sec);
706 if (!bh || !buffer_uptodate(bh)) {
707 unsigned int i;
708
709 for (i = 0; i < ra_count; i++)
710 sb_breadahead(sb, (sector_t)(sec + i));
711 }
712 brelse(bh);
713 return 0;
714 }
715
exfat_get_dentry(struct super_block * sb,struct exfat_chain * p_dir,int entry,struct buffer_head ** bh,sector_t * sector)716 struct exfat_dentry *exfat_get_dentry(struct super_block *sb,
717 struct exfat_chain *p_dir, int entry, struct buffer_head **bh,
718 sector_t *sector)
719 {
720 unsigned int dentries_per_page = EXFAT_B_TO_DEN(PAGE_SIZE);
721 int off;
722 sector_t sec;
723
724 if (p_dir->dir == DIR_DELETED) {
725 exfat_err(sb, "abnormal access to deleted dentry");
726 return NULL;
727 }
728
729 if (exfat_find_location(sb, p_dir, entry, &sec, &off))
730 return NULL;
731
732 if (p_dir->dir != EXFAT_FREE_CLUSTER &&
733 !(entry & (dentries_per_page - 1)))
734 exfat_dir_readahead(sb, sec);
735
736 *bh = sb_bread(sb, sec);
737 if (!*bh)
738 return NULL;
739
740 if (sector)
741 *sector = sec;
742 return (struct exfat_dentry *)((*bh)->b_data + off);
743 }
744
745 enum exfat_validate_dentry_mode {
746 ES_MODE_STARTED,
747 ES_MODE_GET_FILE_ENTRY,
748 ES_MODE_GET_STRM_ENTRY,
749 ES_MODE_GET_NAME_ENTRY,
750 ES_MODE_GET_CRITICAL_SEC_ENTRY,
751 };
752
exfat_validate_entry(unsigned int type,enum exfat_validate_dentry_mode * mode)753 static bool exfat_validate_entry(unsigned int type,
754 enum exfat_validate_dentry_mode *mode)
755 {
756 if (type == TYPE_UNUSED || type == TYPE_DELETED)
757 return false;
758
759 switch (*mode) {
760 case ES_MODE_STARTED:
761 if (type != TYPE_FILE && type != TYPE_DIR)
762 return false;
763 *mode = ES_MODE_GET_FILE_ENTRY;
764 return true;
765 case ES_MODE_GET_FILE_ENTRY:
766 if (type != TYPE_STREAM)
767 return false;
768 *mode = ES_MODE_GET_STRM_ENTRY;
769 return true;
770 case ES_MODE_GET_STRM_ENTRY:
771 if (type != TYPE_EXTEND)
772 return false;
773 *mode = ES_MODE_GET_NAME_ENTRY;
774 return true;
775 case ES_MODE_GET_NAME_ENTRY:
776 if (type == TYPE_STREAM)
777 return false;
778 if (type != TYPE_EXTEND) {
779 if (!(type & TYPE_CRITICAL_SEC))
780 return false;
781 *mode = ES_MODE_GET_CRITICAL_SEC_ENTRY;
782 }
783 return true;
784 case ES_MODE_GET_CRITICAL_SEC_ENTRY:
785 if (type == TYPE_EXTEND || type == TYPE_STREAM)
786 return false;
787 if ((type & TYPE_CRITICAL_SEC) != TYPE_CRITICAL_SEC)
788 return false;
789 return true;
790 default:
791 WARN_ON_ONCE(1);
792 return false;
793 }
794 }
795
exfat_get_dentry_cached(struct exfat_entry_set_cache * es,int num)796 struct exfat_dentry *exfat_get_dentry_cached(
797 struct exfat_entry_set_cache *es, int num)
798 {
799 int off = es->start_off + num * DENTRY_SIZE;
800 struct buffer_head *bh = es->bh[EXFAT_B_TO_BLK(off, es->sb)];
801 char *p = bh->b_data + EXFAT_BLK_OFFSET(off, es->sb);
802
803 return (struct exfat_dentry *)p;
804 }
805
806 /*
807 * Returns a set of dentries for a file or dir.
808 *
809 * Note It provides a direct pointer to bh->data via exfat_get_dentry_cached().
810 * User should call exfat_get_dentry_set() after setting 'modified' to apply
811 * changes made in this entry set to the real device.
812 *
813 * in:
814 * sb+p_dir+entry: indicates a file/dir
815 * type: specifies how many dentries should be included.
816 * return:
817 * pointer of entry set on success,
818 * NULL on failure.
819 */
exfat_get_dentry_set(struct super_block * sb,struct exfat_chain * p_dir,int entry,unsigned int type)820 struct exfat_entry_set_cache *exfat_get_dentry_set(struct super_block *sb,
821 struct exfat_chain *p_dir, int entry, unsigned int type)
822 {
823 int ret, i, num_bh;
824 unsigned int off, byte_offset, clu = 0;
825 sector_t sec;
826 struct exfat_sb_info *sbi = EXFAT_SB(sb);
827 struct exfat_entry_set_cache *es;
828 struct exfat_dentry *ep;
829 int num_entries;
830 enum exfat_validate_dentry_mode mode = ES_MODE_STARTED;
831 struct buffer_head *bh;
832
833 if (p_dir->dir == DIR_DELETED) {
834 exfat_err(sb, "access to deleted dentry");
835 return NULL;
836 }
837
838 byte_offset = EXFAT_DEN_TO_B(entry);
839 ret = exfat_walk_fat_chain(sb, p_dir, byte_offset, &clu);
840 if (ret)
841 return NULL;
842
843 es = kzalloc(sizeof(*es), GFP_KERNEL);
844 if (!es)
845 return NULL;
846 es->sb = sb;
847 es->modified = false;
848
849 /* byte offset in cluster */
850 byte_offset = EXFAT_CLU_OFFSET(byte_offset, sbi);
851
852 /* byte offset in sector */
853 off = EXFAT_BLK_OFFSET(byte_offset, sb);
854 es->start_off = off;
855 es->bh = es->__bh;
856
857 /* sector offset in cluster */
858 sec = EXFAT_B_TO_BLK(byte_offset, sb);
859 sec += exfat_cluster_to_sector(sbi, clu);
860
861 bh = sb_bread(sb, sec);
862 if (!bh)
863 goto free_es;
864 es->bh[es->num_bh++] = bh;
865
866 ep = exfat_get_dentry_cached(es, 0);
867 if (!exfat_validate_entry(exfat_get_entry_type(ep), &mode))
868 goto free_es;
869
870 num_entries = type == ES_ALL_ENTRIES ?
871 ep->dentry.file.num_ext + 1 : type;
872 es->num_entries = num_entries;
873
874 num_bh = EXFAT_B_TO_BLK_ROUND_UP(off + num_entries * DENTRY_SIZE, sb);
875 if (num_bh > ARRAY_SIZE(es->__bh)) {
876 es->bh = kmalloc_array(num_bh, sizeof(*es->bh), GFP_KERNEL);
877 if (!es->bh) {
878 brelse(bh);
879 kfree(es);
880 return NULL;
881 }
882 es->bh[0] = bh;
883 }
884
885 for (i = 1; i < num_bh; i++) {
886 /* get the next sector */
887 if (exfat_is_last_sector_in_cluster(sbi, sec)) {
888 if (p_dir->flags == ALLOC_NO_FAT_CHAIN)
889 clu++;
890 else if (exfat_get_next_cluster(sb, &clu))
891 goto free_es;
892 sec = exfat_cluster_to_sector(sbi, clu);
893 } else {
894 sec++;
895 }
896
897 bh = sb_bread(sb, sec);
898 if (!bh)
899 goto free_es;
900 es->bh[es->num_bh++] = bh;
901 }
902
903 /* validiate cached dentries */
904 for (i = 1; i < num_entries; i++) {
905 ep = exfat_get_dentry_cached(es, i);
906 if (!exfat_validate_entry(exfat_get_entry_type(ep), &mode))
907 goto free_es;
908 }
909 return es;
910
911 free_es:
912 exfat_free_dentry_set(es, false);
913 return NULL;
914 }
915
916 enum {
917 DIRENT_STEP_FILE,
918 DIRENT_STEP_STRM,
919 DIRENT_STEP_NAME,
920 DIRENT_STEP_SECD,
921 };
922
923 /*
924 * @ei: inode info of parent directory
925 * @p_dir: directory structure of parent directory
926 * @num_entries:entry size of p_uniname
927 * @hint_opt: If p_uniname is found, filled with optimized dir/entry
928 * for traversing cluster chain.
929 * @return:
930 * >= 0: file directory entry position where the name exists
931 * -ENOENT: entry with the name does not exist
932 * -EIO: I/O error
933 */
exfat_find_dir_entry(struct super_block * sb,struct exfat_inode_info * ei,struct exfat_chain * p_dir,struct exfat_uni_name * p_uniname,int num_entries,unsigned int type,struct exfat_hint * hint_opt)934 int exfat_find_dir_entry(struct super_block *sb, struct exfat_inode_info *ei,
935 struct exfat_chain *p_dir, struct exfat_uni_name *p_uniname,
936 int num_entries, unsigned int type, struct exfat_hint *hint_opt)
937 {
938 int i, rewind = 0, dentry = 0, end_eidx = 0, num_ext = 0, len;
939 int order, step, name_len = 0;
940 int dentries_per_clu, num_empty = 0;
941 unsigned int entry_type;
942 unsigned short *uniname = NULL;
943 struct exfat_chain clu;
944 struct exfat_hint *hint_stat = &ei->hint_stat;
945 struct exfat_hint_femp candi_empty;
946 struct exfat_sb_info *sbi = EXFAT_SB(sb);
947
948 dentries_per_clu = sbi->dentries_per_clu;
949
950 exfat_chain_dup(&clu, p_dir);
951
952 if (hint_stat->eidx) {
953 clu.dir = hint_stat->clu;
954 dentry = hint_stat->eidx;
955 end_eidx = dentry;
956 }
957
958 candi_empty.eidx = EXFAT_HINT_NONE;
959 rewind:
960 order = 0;
961 step = DIRENT_STEP_FILE;
962 while (clu.dir != EXFAT_EOF_CLUSTER) {
963 i = dentry & (dentries_per_clu - 1);
964 for (; i < dentries_per_clu; i++, dentry++) {
965 struct exfat_dentry *ep;
966 struct buffer_head *bh;
967
968 if (rewind && dentry == end_eidx)
969 goto not_found;
970
971 ep = exfat_get_dentry(sb, &clu, i, &bh, NULL);
972 if (!ep)
973 return -EIO;
974
975 entry_type = exfat_get_entry_type(ep);
976
977 if (entry_type == TYPE_UNUSED ||
978 entry_type == TYPE_DELETED) {
979 step = DIRENT_STEP_FILE;
980
981 num_empty++;
982 if (candi_empty.eidx == EXFAT_HINT_NONE &&
983 num_empty == 1) {
984 exfat_chain_set(&candi_empty.cur,
985 clu.dir, clu.size, clu.flags);
986 }
987
988 if (candi_empty.eidx == EXFAT_HINT_NONE &&
989 num_empty >= num_entries) {
990 candi_empty.eidx =
991 dentry - (num_empty - 1);
992 WARN_ON(candi_empty.eidx < 0);
993 candi_empty.count = num_empty;
994
995 if (ei->hint_femp.eidx ==
996 EXFAT_HINT_NONE ||
997 candi_empty.eidx <=
998 ei->hint_femp.eidx)
999 ei->hint_femp = candi_empty;
1000 }
1001
1002 brelse(bh);
1003 if (entry_type == TYPE_UNUSED)
1004 goto not_found;
1005 continue;
1006 }
1007
1008 num_empty = 0;
1009 candi_empty.eidx = EXFAT_HINT_NONE;
1010
1011 if (entry_type == TYPE_FILE || entry_type == TYPE_DIR) {
1012 step = DIRENT_STEP_FILE;
1013 hint_opt->clu = clu.dir;
1014 hint_opt->eidx = i;
1015 if (type == TYPE_ALL || type == entry_type) {
1016 num_ext = ep->dentry.file.num_ext;
1017 step = DIRENT_STEP_STRM;
1018 }
1019 brelse(bh);
1020 continue;
1021 }
1022
1023 if (entry_type == TYPE_STREAM) {
1024 u16 name_hash;
1025
1026 if (step != DIRENT_STEP_STRM) {
1027 step = DIRENT_STEP_FILE;
1028 brelse(bh);
1029 continue;
1030 }
1031 step = DIRENT_STEP_FILE;
1032 name_hash = le16_to_cpu(
1033 ep->dentry.stream.name_hash);
1034 if (p_uniname->name_hash == name_hash &&
1035 p_uniname->name_len ==
1036 ep->dentry.stream.name_len) {
1037 step = DIRENT_STEP_NAME;
1038 order = 1;
1039 name_len = 0;
1040 }
1041 brelse(bh);
1042 continue;
1043 }
1044
1045 brelse(bh);
1046 if (entry_type == TYPE_EXTEND) {
1047 unsigned short entry_uniname[16], unichar;
1048
1049 if (step != DIRENT_STEP_NAME ||
1050 name_len >= MAX_NAME_LENGTH) {
1051 step = DIRENT_STEP_FILE;
1052 continue;
1053 }
1054
1055 if (++order == 2)
1056 uniname = p_uniname->name;
1057 else
1058 uniname += EXFAT_FILE_NAME_LEN;
1059
1060 len = exfat_extract_uni_name(ep, entry_uniname);
1061 name_len += len;
1062
1063 unichar = *(uniname+len);
1064 *(uniname+len) = 0x0;
1065
1066 if (exfat_uniname_ncmp(sb, uniname,
1067 entry_uniname, len)) {
1068 step = DIRENT_STEP_FILE;
1069 } else if (p_uniname->name_len == name_len) {
1070 if (order == num_ext)
1071 goto found;
1072 step = DIRENT_STEP_SECD;
1073 }
1074
1075 *(uniname+len) = unichar;
1076 continue;
1077 }
1078
1079 if (entry_type &
1080 (TYPE_CRITICAL_SEC | TYPE_BENIGN_SEC)) {
1081 if (step == DIRENT_STEP_SECD) {
1082 if (++order == num_ext)
1083 goto found;
1084 continue;
1085 }
1086 }
1087 step = DIRENT_STEP_FILE;
1088 }
1089
1090 if (clu.flags == ALLOC_NO_FAT_CHAIN) {
1091 if (--clu.size > 0)
1092 clu.dir++;
1093 else
1094 clu.dir = EXFAT_EOF_CLUSTER;
1095 } else {
1096 if (exfat_get_next_cluster(sb, &clu.dir))
1097 return -EIO;
1098 }
1099 }
1100
1101 not_found:
1102 /*
1103 * We started at not 0 index,so we should try to find target
1104 * from 0 index to the index we started at.
1105 */
1106 if (!rewind && end_eidx) {
1107 rewind = 1;
1108 dentry = 0;
1109 clu.dir = p_dir->dir;
1110 /* reset empty hint */
1111 num_empty = 0;
1112 candi_empty.eidx = EXFAT_HINT_NONE;
1113 goto rewind;
1114 }
1115
1116 /* initialized hint_stat */
1117 hint_stat->clu = p_dir->dir;
1118 hint_stat->eidx = 0;
1119 return -ENOENT;
1120
1121 found:
1122 /* next dentry we'll find is out of this cluster */
1123 if (!((dentry + 1) & (dentries_per_clu - 1))) {
1124 int ret = 0;
1125
1126 if (clu.flags == ALLOC_NO_FAT_CHAIN) {
1127 if (--clu.size > 0)
1128 clu.dir++;
1129 else
1130 clu.dir = EXFAT_EOF_CLUSTER;
1131 } else {
1132 ret = exfat_get_next_cluster(sb, &clu.dir);
1133 }
1134
1135 if (ret || clu.dir == EXFAT_EOF_CLUSTER) {
1136 /* just initialized hint_stat */
1137 hint_stat->clu = p_dir->dir;
1138 hint_stat->eidx = 0;
1139 return (dentry - num_ext);
1140 }
1141 }
1142
1143 hint_stat->clu = clu.dir;
1144 hint_stat->eidx = dentry + 1;
1145 return dentry - num_ext;
1146 }
1147
exfat_count_ext_entries(struct super_block * sb,struct exfat_chain * p_dir,int entry,struct exfat_dentry * ep)1148 int exfat_count_ext_entries(struct super_block *sb, struct exfat_chain *p_dir,
1149 int entry, struct exfat_dentry *ep)
1150 {
1151 int i, count = 0;
1152 unsigned int type;
1153 struct exfat_dentry *ext_ep;
1154 struct buffer_head *bh;
1155
1156 for (i = 0, entry++; i < ep->dentry.file.num_ext; i++, entry++) {
1157 ext_ep = exfat_get_dentry(sb, p_dir, entry, &bh, NULL);
1158 if (!ext_ep)
1159 return -EIO;
1160
1161 type = exfat_get_entry_type(ext_ep);
1162 brelse(bh);
1163 if (type == TYPE_EXTEND || type == TYPE_STREAM)
1164 count++;
1165 else
1166 break;
1167 }
1168 return count;
1169 }
1170
exfat_count_dir_entries(struct super_block * sb,struct exfat_chain * p_dir)1171 int exfat_count_dir_entries(struct super_block *sb, struct exfat_chain *p_dir)
1172 {
1173 int i, count = 0;
1174 int dentries_per_clu;
1175 unsigned int entry_type;
1176 struct exfat_chain clu;
1177 struct exfat_dentry *ep;
1178 struct exfat_sb_info *sbi = EXFAT_SB(sb);
1179 struct buffer_head *bh;
1180
1181 dentries_per_clu = sbi->dentries_per_clu;
1182
1183 exfat_chain_dup(&clu, p_dir);
1184
1185 while (clu.dir != EXFAT_EOF_CLUSTER) {
1186 for (i = 0; i < dentries_per_clu; i++) {
1187 ep = exfat_get_dentry(sb, &clu, i, &bh, NULL);
1188 if (!ep)
1189 return -EIO;
1190 entry_type = exfat_get_entry_type(ep);
1191 brelse(bh);
1192
1193 if (entry_type == TYPE_UNUSED)
1194 return count;
1195 if (entry_type != TYPE_DIR)
1196 continue;
1197 count++;
1198 }
1199
1200 if (clu.flags == ALLOC_NO_FAT_CHAIN) {
1201 if (--clu.size > 0)
1202 clu.dir++;
1203 else
1204 clu.dir = EXFAT_EOF_CLUSTER;
1205 } else {
1206 if (exfat_get_next_cluster(sb, &(clu.dir)))
1207 return -EIO;
1208 }
1209 }
1210
1211 return count;
1212 }
1213