xref: /openbmc/linux/fs/exfat/dir.c (revision a7ac198f)
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/compat.h>
8 #include <linux/bio.h>
9 #include <linux/buffer_head.h>
10 
11 #include "exfat_raw.h"
12 #include "exfat_fs.h"
13 
exfat_extract_uni_name(struct exfat_dentry * ep,unsigned short * uniname)14 static int exfat_extract_uni_name(struct exfat_dentry *ep,
15 		unsigned short *uniname)
16 {
17 	int i, len = 0;
18 
19 	for (i = 0; i < EXFAT_FILE_NAME_LEN; i++) {
20 		*uniname = le16_to_cpu(ep->dentry.name.unicode_0_14[i]);
21 		if (*uniname == 0x0)
22 			return len;
23 		uniname++;
24 		len++;
25 	}
26 
27 	*uniname = 0x0;
28 	return len;
29 
30 }
31 
exfat_get_uniname_from_ext_entry(struct super_block * sb,struct exfat_chain * p_dir,int entry,unsigned short * uniname)32 static int exfat_get_uniname_from_ext_entry(struct super_block *sb,
33 		struct exfat_chain *p_dir, int entry, unsigned short *uniname)
34 {
35 	int i, err;
36 	struct exfat_entry_set_cache es;
37 	unsigned int uni_len = 0, len;
38 
39 	err = exfat_get_dentry_set(&es, sb, p_dir, entry, ES_ALL_ENTRIES);
40 	if (err)
41 		return err;
42 
43 	/*
44 	 * First entry  : file entry
45 	 * Second entry : stream-extension entry
46 	 * Third entry  : first file-name entry
47 	 * So, the index of first file-name dentry should start from 2.
48 	 */
49 	for (i = ES_IDX_FIRST_FILENAME; i < es.num_entries; i++) {
50 		struct exfat_dentry *ep = exfat_get_dentry_cached(&es, i);
51 
52 		/* end of name entry */
53 		if (exfat_get_entry_type(ep) != TYPE_EXTEND)
54 			break;
55 
56 		len = exfat_extract_uni_name(ep, uniname);
57 		uni_len += len;
58 		if (len != EXFAT_FILE_NAME_LEN || uni_len >= MAX_NAME_LENGTH)
59 			break;
60 		uniname += EXFAT_FILE_NAME_LEN;
61 	}
62 
63 	exfat_put_dentry_set(&es, false);
64 	return 0;
65 }
66 
67 /* read a directory entry from the opened directory */
exfat_readdir(struct inode * inode,loff_t * cpos,struct exfat_dir_entry * dir_entry)68 static int exfat_readdir(struct inode *inode, loff_t *cpos, struct exfat_dir_entry *dir_entry)
69 {
70 	int i, dentries_per_clu, num_ext, err;
71 	unsigned int type, clu_offset, max_dentries;
72 	struct exfat_chain dir, clu;
73 	struct exfat_uni_name uni_name;
74 	struct exfat_dentry *ep;
75 	struct super_block *sb = inode->i_sb;
76 	struct exfat_sb_info *sbi = EXFAT_SB(sb);
77 	struct exfat_inode_info *ei = EXFAT_I(inode);
78 	unsigned int dentry = EXFAT_B_TO_DEN(*cpos) & 0xFFFFFFFF;
79 	struct buffer_head *bh;
80 
81 	/* check if the given file ID is opened */
82 	if (ei->type != TYPE_DIR)
83 		return -EPERM;
84 
85 	if (ei->entry == -1)
86 		exfat_chain_set(&dir, sbi->root_dir, 0, ALLOC_FAT_CHAIN);
87 	else
88 		exfat_chain_set(&dir, ei->start_clu,
89 			EXFAT_B_TO_CLU(i_size_read(inode), sbi), ei->flags);
90 
91 	dentries_per_clu = sbi->dentries_per_clu;
92 	max_dentries = (unsigned int)min_t(u64, MAX_EXFAT_DENTRIES,
93 				(u64)EXFAT_CLU_TO_DEN(sbi->num_clusters, sbi));
94 
95 	clu_offset = EXFAT_DEN_TO_CLU(dentry, sbi);
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);
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 			err = exfat_get_uniname_from_ext_entry(sb, &clu, i,
156 				uni_name.name);
157 			if (err) {
158 				brelse(bh);
159 				continue;
160 			}
161 			exfat_utf16_to_nls(sb, &uni_name,
162 				dir_entry->namebuf.lfn,
163 				dir_entry->namebuf.lfnbuf_len);
164 			brelse(bh);
165 
166 			ep = exfat_get_dentry(sb, &clu, i + 1, &bh);
167 			if (!ep)
168 				return -EIO;
169 			dir_entry->size =
170 				le64_to_cpu(ep->dentry.stream.valid_size);
171 			dir_entry->entry = dentry;
172 			brelse(bh);
173 
174 			ei->hint_bmap.off = EXFAT_DEN_TO_CLU(dentry, sbi);
175 			ei->hint_bmap.clu = clu.dir;
176 
177 			*cpos = EXFAT_DEN_TO_B(dentry + 1 + num_ext);
178 			return 0;
179 		}
180 
181 		if (clu.flags == ALLOC_NO_FAT_CHAIN) {
182 			if (--clu.size > 0)
183 				clu.dir++;
184 			else
185 				clu.dir = EXFAT_EOF_CLUSTER;
186 		} else {
187 			if (exfat_get_next_cluster(sb, &(clu.dir)))
188 				return -EIO;
189 		}
190 	}
191 
192 	dir_entry->namebuf.lfn[0] = '\0';
193 	*cpos = EXFAT_DEN_TO_B(dentry);
194 	return 0;
195 }
196 
exfat_init_namebuf(struct exfat_dentry_namebuf * nb)197 static void exfat_init_namebuf(struct exfat_dentry_namebuf *nb)
198 {
199 	nb->lfn = NULL;
200 	nb->lfnbuf_len = 0;
201 }
202 
exfat_alloc_namebuf(struct exfat_dentry_namebuf * nb)203 static int exfat_alloc_namebuf(struct exfat_dentry_namebuf *nb)
204 {
205 	nb->lfn = __getname();
206 	if (!nb->lfn)
207 		return -ENOMEM;
208 	nb->lfnbuf_len = MAX_VFSNAME_BUF_SIZE;
209 	return 0;
210 }
211 
exfat_free_namebuf(struct exfat_dentry_namebuf * nb)212 static void exfat_free_namebuf(struct exfat_dentry_namebuf *nb)
213 {
214 	if (!nb->lfn)
215 		return;
216 
217 	__putname(nb->lfn);
218 	exfat_init_namebuf(nb);
219 }
220 
221 /*
222  * Before calling dir_emit*(), sbi->s_lock should be released
223  * because page fault can occur in dir_emit*().
224  */
225 #define ITER_POS_FILLED_DOTS    (2)
exfat_iterate(struct file * file,struct dir_context * ctx)226 static int exfat_iterate(struct file *file, struct dir_context *ctx)
227 {
228 	struct inode *inode = file_inode(file);
229 	struct super_block *sb = inode->i_sb;
230 	struct inode *tmp;
231 	struct exfat_dir_entry de;
232 	struct exfat_dentry_namebuf *nb = &(de.namebuf);
233 	struct exfat_inode_info *ei = EXFAT_I(inode);
234 	unsigned long inum;
235 	loff_t cpos, i_pos;
236 	int err = 0, fake_offset = 0;
237 
238 	exfat_init_namebuf(nb);
239 
240 	cpos = ctx->pos;
241 	if (!dir_emit_dots(file, ctx))
242 		goto out;
243 
244 	if (ctx->pos == ITER_POS_FILLED_DOTS) {
245 		cpos = 0;
246 		fake_offset = 1;
247 	}
248 
249 	cpos = round_up(cpos, DENTRY_SIZE);
250 
251 	/* name buffer should be allocated before use */
252 	err = exfat_alloc_namebuf(nb);
253 	if (err)
254 		goto out;
255 get_new:
256 	mutex_lock(&EXFAT_SB(sb)->s_lock);
257 
258 	if (ei->flags == ALLOC_NO_FAT_CHAIN && cpos >= i_size_read(inode))
259 		goto end_of_dir;
260 
261 	err = exfat_readdir(inode, &cpos, &de);
262 	if (err) {
263 		/*
264 		 * At least we tried to read a sector.
265 		 * Move cpos to next sector position (should be aligned).
266 		 */
267 		if (err == -EIO) {
268 			cpos += 1 << (sb->s_blocksize_bits);
269 			cpos &= ~(sb->s_blocksize - 1);
270 		}
271 
272 		err = -EIO;
273 		goto end_of_dir;
274 	}
275 
276 	if (!nb->lfn[0])
277 		goto end_of_dir;
278 
279 	i_pos = ((loff_t)ei->start_clu << 32) |	(de.entry & 0xffffffff);
280 	tmp = exfat_iget(sb, i_pos);
281 	if (tmp) {
282 		inum = tmp->i_ino;
283 		iput(tmp);
284 	} else {
285 		inum = iunique(sb, EXFAT_ROOT_INO);
286 	}
287 
288 	mutex_unlock(&EXFAT_SB(sb)->s_lock);
289 	if (!dir_emit(ctx, nb->lfn, strlen(nb->lfn), inum,
290 			(de.attr & ATTR_SUBDIR) ? DT_DIR : DT_REG))
291 		goto out;
292 	ctx->pos = cpos;
293 	goto get_new;
294 
295 end_of_dir:
296 	if (!cpos && fake_offset)
297 		cpos = ITER_POS_FILLED_DOTS;
298 	ctx->pos = cpos;
299 	mutex_unlock(&EXFAT_SB(sb)->s_lock);
300 out:
301 	/*
302 	 * To improve performance, free namebuf after unlock sb_lock.
303 	 * If namebuf is not allocated, this function do nothing
304 	 */
305 	exfat_free_namebuf(nb);
306 	return err;
307 }
308 
309 WRAP_DIR_ITER(exfat_iterate) // FIXME!
310 const struct file_operations exfat_dir_operations = {
311 	.llseek		= generic_file_llseek,
312 	.read		= generic_read_dir,
313 	.iterate_shared	= shared_exfat_iterate,
314 	.unlocked_ioctl = exfat_ioctl,
315 #ifdef CONFIG_COMPAT
316 	.compat_ioctl = exfat_compat_ioctl,
317 #endif
318 	.fsync		= exfat_file_fsync,
319 };
320 
exfat_alloc_new_dir(struct inode * inode,struct exfat_chain * clu)321 int exfat_alloc_new_dir(struct inode *inode, struct exfat_chain *clu)
322 {
323 	int ret;
324 
325 	exfat_chain_set(clu, EXFAT_EOF_CLUSTER, 0, ALLOC_NO_FAT_CHAIN);
326 
327 	ret = exfat_alloc_cluster(inode, 1, clu, IS_DIRSYNC(inode));
328 	if (ret)
329 		return ret;
330 
331 	return exfat_zeroed_cluster(inode, clu->dir);
332 }
333 
exfat_calc_num_entries(struct exfat_uni_name * p_uniname)334 int exfat_calc_num_entries(struct exfat_uni_name *p_uniname)
335 {
336 	int len;
337 
338 	len = p_uniname->name_len;
339 	if (len == 0)
340 		return -EINVAL;
341 
342 	/* 1 file entry + 1 stream entry + name entries */
343 	return ES_ENTRY_NUM(len);
344 }
345 
exfat_get_entry_type(struct exfat_dentry * ep)346 unsigned int exfat_get_entry_type(struct exfat_dentry *ep)
347 {
348 	if (ep->type == EXFAT_UNUSED)
349 		return TYPE_UNUSED;
350 	if (IS_EXFAT_DELETED(ep->type))
351 		return TYPE_DELETED;
352 	if (ep->type == EXFAT_INVAL)
353 		return TYPE_INVALID;
354 	if (IS_EXFAT_CRITICAL_PRI(ep->type)) {
355 		if (ep->type == EXFAT_BITMAP)
356 			return TYPE_BITMAP;
357 		if (ep->type == EXFAT_UPCASE)
358 			return TYPE_UPCASE;
359 		if (ep->type == EXFAT_VOLUME)
360 			return TYPE_VOLUME;
361 		if (ep->type == EXFAT_FILE) {
362 			if (le16_to_cpu(ep->dentry.file.attr) & ATTR_SUBDIR)
363 				return TYPE_DIR;
364 			return TYPE_FILE;
365 		}
366 		return TYPE_CRITICAL_PRI;
367 	}
368 	if (IS_EXFAT_BENIGN_PRI(ep->type)) {
369 		if (ep->type == EXFAT_GUID)
370 			return TYPE_GUID;
371 		if (ep->type == EXFAT_PADDING)
372 			return TYPE_PADDING;
373 		if (ep->type == EXFAT_ACLTAB)
374 			return TYPE_ACLTAB;
375 		return TYPE_BENIGN_PRI;
376 	}
377 	if (IS_EXFAT_CRITICAL_SEC(ep->type)) {
378 		if (ep->type == EXFAT_STREAM)
379 			return TYPE_STREAM;
380 		if (ep->type == EXFAT_NAME)
381 			return TYPE_EXTEND;
382 		if (ep->type == EXFAT_ACL)
383 			return TYPE_ACL;
384 		return TYPE_CRITICAL_SEC;
385 	}
386 
387 	if (ep->type == EXFAT_VENDOR_EXT)
388 		return TYPE_VENDOR_EXT;
389 	if (ep->type == EXFAT_VENDOR_ALLOC)
390 		return TYPE_VENDOR_ALLOC;
391 
392 	return TYPE_BENIGN_SEC;
393 }
394 
exfat_set_entry_type(struct exfat_dentry * ep,unsigned int type)395 static void exfat_set_entry_type(struct exfat_dentry *ep, unsigned int type)
396 {
397 	if (type == TYPE_UNUSED) {
398 		ep->type = EXFAT_UNUSED;
399 	} else if (type == TYPE_DELETED) {
400 		ep->type &= EXFAT_DELETE;
401 	} else if (type == TYPE_STREAM) {
402 		ep->type = EXFAT_STREAM;
403 	} else if (type == TYPE_EXTEND) {
404 		ep->type = EXFAT_NAME;
405 	} else if (type == TYPE_BITMAP) {
406 		ep->type = EXFAT_BITMAP;
407 	} else if (type == TYPE_UPCASE) {
408 		ep->type = EXFAT_UPCASE;
409 	} else if (type == TYPE_VOLUME) {
410 		ep->type = EXFAT_VOLUME;
411 	} else if (type == TYPE_DIR) {
412 		ep->type = EXFAT_FILE;
413 		ep->dentry.file.attr = cpu_to_le16(ATTR_SUBDIR);
414 	} else if (type == TYPE_FILE) {
415 		ep->type = EXFAT_FILE;
416 		ep->dentry.file.attr = cpu_to_le16(ATTR_ARCHIVE);
417 	}
418 }
419 
exfat_init_stream_entry(struct exfat_dentry * ep,unsigned char flags,unsigned int start_clu,unsigned long long size)420 static void exfat_init_stream_entry(struct exfat_dentry *ep,
421 		unsigned char flags, unsigned int start_clu,
422 		unsigned long long size)
423 {
424 	exfat_set_entry_type(ep, TYPE_STREAM);
425 	ep->dentry.stream.flags = flags;
426 	ep->dentry.stream.start_clu = cpu_to_le32(start_clu);
427 	ep->dentry.stream.valid_size = cpu_to_le64(size);
428 	ep->dentry.stream.size = cpu_to_le64(size);
429 }
430 
exfat_init_name_entry(struct exfat_dentry * ep,unsigned short * uniname)431 static void exfat_init_name_entry(struct exfat_dentry *ep,
432 		unsigned short *uniname)
433 {
434 	int i;
435 
436 	exfat_set_entry_type(ep, TYPE_EXTEND);
437 	ep->dentry.name.flags = 0x0;
438 
439 	for (i = 0; i < EXFAT_FILE_NAME_LEN; i++) {
440 		if (*uniname != 0x0) {
441 			ep->dentry.name.unicode_0_14[i] = cpu_to_le16(*uniname);
442 			uniname++;
443 		} else {
444 			ep->dentry.name.unicode_0_14[i] = 0x0;
445 		}
446 	}
447 }
448 
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)449 int exfat_init_dir_entry(struct inode *inode, struct exfat_chain *p_dir,
450 		int entry, unsigned int type, unsigned int start_clu,
451 		unsigned long long size)
452 {
453 	struct super_block *sb = inode->i_sb;
454 	struct exfat_sb_info *sbi = EXFAT_SB(sb);
455 	struct timespec64 ts = current_time(inode);
456 	struct exfat_dentry *ep;
457 	struct buffer_head *bh;
458 
459 	/*
460 	 * We cannot use exfat_get_dentry_set here because file ep is not
461 	 * initialized yet.
462 	 */
463 	ep = exfat_get_dentry(sb, p_dir, entry, &bh);
464 	if (!ep)
465 		return -EIO;
466 
467 	exfat_set_entry_type(ep, type);
468 	exfat_set_entry_time(sbi, &ts,
469 			&ep->dentry.file.create_tz,
470 			&ep->dentry.file.create_time,
471 			&ep->dentry.file.create_date,
472 			&ep->dentry.file.create_time_cs);
473 	exfat_set_entry_time(sbi, &ts,
474 			&ep->dentry.file.modify_tz,
475 			&ep->dentry.file.modify_time,
476 			&ep->dentry.file.modify_date,
477 			&ep->dentry.file.modify_time_cs);
478 	exfat_set_entry_time(sbi, &ts,
479 			&ep->dentry.file.access_tz,
480 			&ep->dentry.file.access_time,
481 			&ep->dentry.file.access_date,
482 			NULL);
483 
484 	exfat_update_bh(bh, IS_DIRSYNC(inode));
485 	brelse(bh);
486 
487 	ep = exfat_get_dentry(sb, p_dir, entry + 1, &bh);
488 	if (!ep)
489 		return -EIO;
490 
491 	exfat_init_stream_entry(ep,
492 		(type == TYPE_FILE) ? ALLOC_FAT_CHAIN : ALLOC_NO_FAT_CHAIN,
493 		start_clu, size);
494 	exfat_update_bh(bh, IS_DIRSYNC(inode));
495 	brelse(bh);
496 
497 	return 0;
498 }
499 
exfat_update_dir_chksum(struct inode * inode,struct exfat_chain * p_dir,int entry)500 int exfat_update_dir_chksum(struct inode *inode, struct exfat_chain *p_dir,
501 		int entry)
502 {
503 	struct super_block *sb = inode->i_sb;
504 	int ret = 0;
505 	int i, num_entries;
506 	u16 chksum;
507 	struct exfat_dentry *ep, *fep;
508 	struct buffer_head *fbh, *bh;
509 
510 	fep = exfat_get_dentry(sb, p_dir, entry, &fbh);
511 	if (!fep)
512 		return -EIO;
513 
514 	num_entries = fep->dentry.file.num_ext + 1;
515 	chksum = exfat_calc_chksum16(fep, DENTRY_SIZE, 0, CS_DIR_ENTRY);
516 
517 	for (i = 1; i < num_entries; i++) {
518 		ep = exfat_get_dentry(sb, p_dir, entry + i, &bh);
519 		if (!ep) {
520 			ret = -EIO;
521 			goto release_fbh;
522 		}
523 		chksum = exfat_calc_chksum16(ep, DENTRY_SIZE, chksum,
524 				CS_DEFAULT);
525 		brelse(bh);
526 	}
527 
528 	fep->dentry.file.checksum = cpu_to_le16(chksum);
529 	exfat_update_bh(fbh, IS_DIRSYNC(inode));
530 release_fbh:
531 	brelse(fbh);
532 	return ret;
533 }
534 
exfat_free_benign_secondary_clusters(struct inode * inode,struct exfat_dentry * ep)535 static void exfat_free_benign_secondary_clusters(struct inode *inode,
536 		struct exfat_dentry *ep)
537 {
538 	struct super_block *sb = inode->i_sb;
539 	struct exfat_chain dir;
540 	unsigned int start_clu =
541 		le32_to_cpu(ep->dentry.generic_secondary.start_clu);
542 	u64 size = le64_to_cpu(ep->dentry.generic_secondary.size);
543 	unsigned char flags = ep->dentry.generic_secondary.flags;
544 
545 	if (!(flags & ALLOC_POSSIBLE) || !start_clu || !size)
546 		return;
547 
548 	exfat_chain_set(&dir, start_clu,
549 			EXFAT_B_TO_CLU_ROUND_UP(size, EXFAT_SB(sb)),
550 			flags);
551 	exfat_free_cluster(inode, &dir);
552 }
553 
exfat_init_ext_entry(struct inode * inode,struct exfat_chain * p_dir,int entry,int num_entries,struct exfat_uni_name * p_uniname)554 int exfat_init_ext_entry(struct inode *inode, struct exfat_chain *p_dir,
555 		int entry, int num_entries, struct exfat_uni_name *p_uniname)
556 {
557 	struct super_block *sb = inode->i_sb;
558 	int i;
559 	unsigned short *uniname = p_uniname->name;
560 	struct exfat_dentry *ep;
561 	struct buffer_head *bh;
562 	int sync = IS_DIRSYNC(inode);
563 
564 	ep = exfat_get_dentry(sb, p_dir, entry, &bh);
565 	if (!ep)
566 		return -EIO;
567 
568 	ep->dentry.file.num_ext = (unsigned char)(num_entries - 1);
569 	exfat_update_bh(bh, sync);
570 	brelse(bh);
571 
572 	ep = exfat_get_dentry(sb, p_dir, entry + 1, &bh);
573 	if (!ep)
574 		return -EIO;
575 
576 	ep->dentry.stream.name_len = p_uniname->name_len;
577 	ep->dentry.stream.name_hash = cpu_to_le16(p_uniname->name_hash);
578 	exfat_update_bh(bh, sync);
579 	brelse(bh);
580 
581 	for (i = EXFAT_FIRST_CLUSTER; i < num_entries; i++) {
582 		ep = exfat_get_dentry(sb, p_dir, entry + i, &bh);
583 		if (!ep)
584 			return -EIO;
585 
586 		if (exfat_get_entry_type(ep) & TYPE_BENIGN_SEC)
587 			exfat_free_benign_secondary_clusters(inode, ep);
588 
589 		exfat_init_name_entry(ep, uniname);
590 		exfat_update_bh(bh, sync);
591 		brelse(bh);
592 		uniname += EXFAT_FILE_NAME_LEN;
593 	}
594 
595 	exfat_update_dir_chksum(inode, p_dir, entry);
596 	return 0;
597 }
598 
exfat_remove_entries(struct inode * inode,struct exfat_chain * p_dir,int entry,int order,int num_entries)599 int exfat_remove_entries(struct inode *inode, struct exfat_chain *p_dir,
600 		int entry, int order, int num_entries)
601 {
602 	struct super_block *sb = inode->i_sb;
603 	int i;
604 	struct exfat_dentry *ep;
605 	struct buffer_head *bh;
606 
607 	for (i = order; i < num_entries; i++) {
608 		ep = exfat_get_dentry(sb, p_dir, entry + i, &bh);
609 		if (!ep)
610 			return -EIO;
611 
612 		if (exfat_get_entry_type(ep) & TYPE_BENIGN_SEC)
613 			exfat_free_benign_secondary_clusters(inode, ep);
614 
615 		exfat_set_entry_type(ep, TYPE_DELETED);
616 		exfat_update_bh(bh, IS_DIRSYNC(inode));
617 		brelse(bh);
618 	}
619 
620 	return 0;
621 }
622 
exfat_update_dir_chksum_with_entry_set(struct exfat_entry_set_cache * es)623 void exfat_update_dir_chksum_with_entry_set(struct exfat_entry_set_cache *es)
624 {
625 	int chksum_type = CS_DIR_ENTRY, i;
626 	unsigned short chksum = 0;
627 	struct exfat_dentry *ep;
628 
629 	for (i = ES_IDX_FILE; i < es->num_entries; i++) {
630 		ep = exfat_get_dentry_cached(es, i);
631 		chksum = exfat_calc_chksum16(ep, DENTRY_SIZE, chksum,
632 					     chksum_type);
633 		chksum_type = CS_DEFAULT;
634 	}
635 	ep = exfat_get_dentry_cached(es, ES_IDX_FILE);
636 	ep->dentry.file.checksum = cpu_to_le16(chksum);
637 	es->modified = true;
638 }
639 
exfat_put_dentry_set(struct exfat_entry_set_cache * es,int sync)640 int exfat_put_dentry_set(struct exfat_entry_set_cache *es, int sync)
641 {
642 	int i, err = 0;
643 
644 	if (es->modified)
645 		err = exfat_update_bhs(es->bh, es->num_bh, sync);
646 
647 	for (i = 0; i < es->num_bh; i++)
648 		if (err)
649 			bforget(es->bh[i]);
650 		else
651 			brelse(es->bh[i]);
652 
653 	if (IS_DYNAMIC_ES(es))
654 		kfree(es->bh);
655 
656 	return err;
657 }
658 
exfat_walk_fat_chain(struct super_block * sb,struct exfat_chain * p_dir,unsigned int byte_offset,unsigned int * clu)659 static int exfat_walk_fat_chain(struct super_block *sb,
660 		struct exfat_chain *p_dir, unsigned int byte_offset,
661 		unsigned int *clu)
662 {
663 	struct exfat_sb_info *sbi = EXFAT_SB(sb);
664 	unsigned int clu_offset;
665 	unsigned int cur_clu;
666 
667 	clu_offset = EXFAT_B_TO_CLU(byte_offset, sbi);
668 	cur_clu = p_dir->dir;
669 
670 	if (p_dir->flags == ALLOC_NO_FAT_CHAIN) {
671 		cur_clu += clu_offset;
672 	} else {
673 		while (clu_offset > 0) {
674 			if (exfat_get_next_cluster(sb, &cur_clu))
675 				return -EIO;
676 			if (cur_clu == EXFAT_EOF_CLUSTER) {
677 				exfat_fs_error(sb,
678 					"invalid dentry access beyond EOF (clu : %u, eidx : %d)",
679 					p_dir->dir,
680 					EXFAT_B_TO_DEN(byte_offset));
681 				return -EIO;
682 			}
683 			clu_offset--;
684 		}
685 	}
686 
687 	*clu = cur_clu;
688 	return 0;
689 }
690 
exfat_find_location(struct super_block * sb,struct exfat_chain * p_dir,int entry,sector_t * sector,int * offset)691 static int exfat_find_location(struct super_block *sb, struct exfat_chain *p_dir,
692 			       int entry, sector_t *sector, int *offset)
693 {
694 	int ret;
695 	unsigned int off, clu = 0;
696 	struct exfat_sb_info *sbi = EXFAT_SB(sb);
697 
698 	off = EXFAT_DEN_TO_B(entry);
699 
700 	ret = exfat_walk_fat_chain(sb, p_dir, off, &clu);
701 	if (ret)
702 		return ret;
703 
704 	/* byte offset in cluster */
705 	off = EXFAT_CLU_OFFSET(off, sbi);
706 
707 	/* byte offset in sector    */
708 	*offset = EXFAT_BLK_OFFSET(off, sb);
709 
710 	/* sector offset in cluster */
711 	*sector = EXFAT_B_TO_BLK(off, sb);
712 	*sector += exfat_cluster_to_sector(sbi, clu);
713 	return 0;
714 }
715 
716 #define EXFAT_MAX_RA_SIZE     (128*1024)
exfat_dir_readahead(struct super_block * sb,sector_t sec)717 static int exfat_dir_readahead(struct super_block *sb, sector_t sec)
718 {
719 	struct exfat_sb_info *sbi = EXFAT_SB(sb);
720 	struct buffer_head *bh;
721 	unsigned int max_ra_count = EXFAT_MAX_RA_SIZE >> sb->s_blocksize_bits;
722 	unsigned int page_ra_count = PAGE_SIZE >> sb->s_blocksize_bits;
723 	unsigned int adj_ra_count = max(sbi->sect_per_clus, page_ra_count);
724 	unsigned int ra_count = min(adj_ra_count, max_ra_count);
725 
726 	/* Read-ahead is not required */
727 	if (sbi->sect_per_clus == 1)
728 		return 0;
729 
730 	if (sec < sbi->data_start_sector) {
731 		exfat_err(sb, "requested sector is invalid(sect:%llu, root:%llu)",
732 			  (unsigned long long)sec, sbi->data_start_sector);
733 		return -EIO;
734 	}
735 
736 	/* Not sector aligned with ra_count, resize ra_count to page size */
737 	if ((sec - sbi->data_start_sector) & (ra_count - 1))
738 		ra_count = page_ra_count;
739 
740 	bh = sb_find_get_block(sb, sec);
741 	if (!bh || !buffer_uptodate(bh)) {
742 		unsigned int i;
743 
744 		for (i = 0; i < ra_count; i++)
745 			sb_breadahead(sb, (sector_t)(sec + i));
746 	}
747 	brelse(bh);
748 	return 0;
749 }
750 
exfat_get_dentry(struct super_block * sb,struct exfat_chain * p_dir,int entry,struct buffer_head ** bh)751 struct exfat_dentry *exfat_get_dentry(struct super_block *sb,
752 		struct exfat_chain *p_dir, int entry, struct buffer_head **bh)
753 {
754 	unsigned int dentries_per_page = EXFAT_B_TO_DEN(PAGE_SIZE);
755 	int off;
756 	sector_t sec;
757 
758 	if (p_dir->dir == DIR_DELETED) {
759 		exfat_err(sb, "abnormal access to deleted dentry");
760 		return NULL;
761 	}
762 
763 	if (exfat_find_location(sb, p_dir, entry, &sec, &off))
764 		return NULL;
765 
766 	if (p_dir->dir != EXFAT_FREE_CLUSTER &&
767 			!(entry & (dentries_per_page - 1)))
768 		exfat_dir_readahead(sb, sec);
769 
770 	*bh = sb_bread(sb, sec);
771 	if (!*bh)
772 		return NULL;
773 
774 	return (struct exfat_dentry *)((*bh)->b_data + off);
775 }
776 
777 enum exfat_validate_dentry_mode {
778 	ES_MODE_STARTED,
779 	ES_MODE_GET_FILE_ENTRY,
780 	ES_MODE_GET_STRM_ENTRY,
781 	ES_MODE_GET_NAME_ENTRY,
782 	ES_MODE_GET_CRITICAL_SEC_ENTRY,
783 	ES_MODE_GET_BENIGN_SEC_ENTRY,
784 };
785 
exfat_validate_entry(unsigned int type,enum exfat_validate_dentry_mode * mode)786 static bool exfat_validate_entry(unsigned int type,
787 		enum exfat_validate_dentry_mode *mode)
788 {
789 	if (type == TYPE_UNUSED || type == TYPE_DELETED)
790 		return false;
791 
792 	switch (*mode) {
793 	case ES_MODE_STARTED:
794 		if  (type != TYPE_FILE && type != TYPE_DIR)
795 			return false;
796 		*mode = ES_MODE_GET_FILE_ENTRY;
797 		break;
798 	case ES_MODE_GET_FILE_ENTRY:
799 		if (type != TYPE_STREAM)
800 			return false;
801 		*mode = ES_MODE_GET_STRM_ENTRY;
802 		break;
803 	case ES_MODE_GET_STRM_ENTRY:
804 		if (type != TYPE_EXTEND)
805 			return false;
806 		*mode = ES_MODE_GET_NAME_ENTRY;
807 		break;
808 	case ES_MODE_GET_NAME_ENTRY:
809 		if (type & TYPE_BENIGN_SEC)
810 			*mode = ES_MODE_GET_BENIGN_SEC_ENTRY;
811 		else if (type != TYPE_EXTEND)
812 			return false;
813 		break;
814 	case ES_MODE_GET_BENIGN_SEC_ENTRY:
815 		/* Assume unreconized benign secondary entry */
816 		if (!(type & TYPE_BENIGN_SEC))
817 			return false;
818 		break;
819 	default:
820 		return false;
821 	}
822 
823 	return true;
824 }
825 
exfat_get_dentry_cached(struct exfat_entry_set_cache * es,int num)826 struct exfat_dentry *exfat_get_dentry_cached(
827 	struct exfat_entry_set_cache *es, int num)
828 {
829 	int off = es->start_off + num * DENTRY_SIZE;
830 	struct buffer_head *bh = es->bh[EXFAT_B_TO_BLK(off, es->sb)];
831 	char *p = bh->b_data + EXFAT_BLK_OFFSET(off, es->sb);
832 
833 	return (struct exfat_dentry *)p;
834 }
835 
836 /*
837  * Returns a set of dentries for a file or dir.
838  *
839  * Note It provides a direct pointer to bh->data via exfat_get_dentry_cached().
840  * User should call exfat_get_dentry_set() after setting 'modified' to apply
841  * changes made in this entry set to the real device.
842  *
843  * in:
844  *   sb+p_dir+entry: indicates a file/dir
845  *   type:  specifies how many dentries should be included.
846  * return:
847  *   pointer of entry set on success,
848  *   NULL on failure.
849  */
exfat_get_dentry_set(struct exfat_entry_set_cache * es,struct super_block * sb,struct exfat_chain * p_dir,int entry,unsigned int type)850 int exfat_get_dentry_set(struct exfat_entry_set_cache *es,
851 		struct super_block *sb, struct exfat_chain *p_dir, int entry,
852 		unsigned int type)
853 {
854 	int ret, i, num_bh;
855 	unsigned int off;
856 	sector_t sec;
857 	struct exfat_sb_info *sbi = EXFAT_SB(sb);
858 	struct exfat_dentry *ep;
859 	int num_entries;
860 	enum exfat_validate_dentry_mode mode = ES_MODE_STARTED;
861 	struct buffer_head *bh;
862 
863 	if (p_dir->dir == DIR_DELETED) {
864 		exfat_err(sb, "access to deleted dentry");
865 		return -EIO;
866 	}
867 
868 	ret = exfat_find_location(sb, p_dir, entry, &sec, &off);
869 	if (ret)
870 		return ret;
871 
872 	memset(es, 0, sizeof(*es));
873 	es->sb = sb;
874 	es->modified = false;
875 	es->start_off = off;
876 	es->bh = es->__bh;
877 
878 	bh = sb_bread(sb, sec);
879 	if (!bh)
880 		return -EIO;
881 	es->bh[es->num_bh++] = bh;
882 
883 	ep = exfat_get_dentry_cached(es, ES_IDX_FILE);
884 	if (!exfat_validate_entry(exfat_get_entry_type(ep), &mode))
885 		goto put_es;
886 
887 	num_entries = type == ES_ALL_ENTRIES ?
888 		ep->dentry.file.num_ext + 1 : type;
889 	es->num_entries = num_entries;
890 
891 	num_bh = EXFAT_B_TO_BLK_ROUND_UP(off + num_entries * DENTRY_SIZE, sb);
892 	if (num_bh > ARRAY_SIZE(es->__bh)) {
893 		es->bh = kmalloc_array(num_bh, sizeof(*es->bh), GFP_NOFS);
894 		if (!es->bh) {
895 			brelse(bh);
896 			return -ENOMEM;
897 		}
898 		es->bh[0] = bh;
899 	}
900 
901 	for (i = 1; i < num_bh; i++) {
902 		/* get the next sector */
903 		if (exfat_is_last_sector_in_cluster(sbi, sec)) {
904 			unsigned int clu = exfat_sector_to_cluster(sbi, sec);
905 
906 			if (p_dir->flags == ALLOC_NO_FAT_CHAIN)
907 				clu++;
908 			else if (exfat_get_next_cluster(sb, &clu))
909 				goto put_es;
910 			sec = exfat_cluster_to_sector(sbi, clu);
911 		} else {
912 			sec++;
913 		}
914 
915 		bh = sb_bread(sb, sec);
916 		if (!bh)
917 			goto put_es;
918 		es->bh[es->num_bh++] = bh;
919 	}
920 
921 	/* validate cached dentries */
922 	for (i = ES_IDX_STREAM; i < num_entries; i++) {
923 		ep = exfat_get_dentry_cached(es, i);
924 		if (!exfat_validate_entry(exfat_get_entry_type(ep), &mode))
925 			goto put_es;
926 	}
927 	return 0;
928 
929 put_es:
930 	exfat_put_dentry_set(es, false);
931 	return -EIO;
932 }
933 
exfat_reset_empty_hint(struct exfat_hint_femp * hint_femp)934 static inline void exfat_reset_empty_hint(struct exfat_hint_femp *hint_femp)
935 {
936 	hint_femp->eidx = EXFAT_HINT_NONE;
937 	hint_femp->count = 0;
938 }
939 
exfat_set_empty_hint(struct exfat_inode_info * ei,struct exfat_hint_femp * candi_empty,struct exfat_chain * clu,int dentry,int num_entries,int entry_type)940 static inline void exfat_set_empty_hint(struct exfat_inode_info *ei,
941 		struct exfat_hint_femp *candi_empty, struct exfat_chain *clu,
942 		int dentry, int num_entries, int entry_type)
943 {
944 	if (ei->hint_femp.eidx == EXFAT_HINT_NONE ||
945 	    ei->hint_femp.eidx > dentry) {
946 		int total_entries = EXFAT_B_TO_DEN(i_size_read(&ei->vfs_inode));
947 
948 		if (candi_empty->count == 0) {
949 			candi_empty->cur = *clu;
950 			candi_empty->eidx = dentry;
951 		}
952 
953 		if (entry_type == TYPE_UNUSED)
954 			candi_empty->count += total_entries - dentry;
955 		else
956 			candi_empty->count++;
957 
958 		if (candi_empty->count == num_entries ||
959 		    candi_empty->count + candi_empty->eidx == total_entries)
960 			ei->hint_femp = *candi_empty;
961 	}
962 }
963 
964 enum {
965 	DIRENT_STEP_FILE,
966 	DIRENT_STEP_STRM,
967 	DIRENT_STEP_NAME,
968 	DIRENT_STEP_SECD,
969 };
970 
971 /*
972  * @ei:         inode info of parent directory
973  * @p_dir:      directory structure of parent directory
974  * @num_entries:entry size of p_uniname
975  * @hint_opt:   If p_uniname is found, filled with optimized dir/entry
976  *              for traversing cluster chain.
977  * @return:
978  *   >= 0:      file directory entry position where the name exists
979  *   -ENOENT:   entry with the name does not exist
980  *   -EIO:      I/O error
981  */
exfat_find_dir_entry(struct super_block * sb,struct exfat_inode_info * ei,struct exfat_chain * p_dir,struct exfat_uni_name * p_uniname,struct exfat_hint * hint_opt)982 int exfat_find_dir_entry(struct super_block *sb, struct exfat_inode_info *ei,
983 		struct exfat_chain *p_dir, struct exfat_uni_name *p_uniname,
984 		struct exfat_hint *hint_opt)
985 {
986 	int i, rewind = 0, dentry = 0, end_eidx = 0, num_ext = 0, len;
987 	int order, step, name_len = 0;
988 	int dentries_per_clu;
989 	unsigned int entry_type;
990 	unsigned short *uniname = NULL;
991 	struct exfat_chain clu;
992 	struct exfat_hint *hint_stat = &ei->hint_stat;
993 	struct exfat_hint_femp candi_empty;
994 	struct exfat_sb_info *sbi = EXFAT_SB(sb);
995 	int num_entries = exfat_calc_num_entries(p_uniname);
996 
997 	if (num_entries < 0)
998 		return num_entries;
999 
1000 	dentries_per_clu = sbi->dentries_per_clu;
1001 
1002 	exfat_chain_dup(&clu, p_dir);
1003 
1004 	if (hint_stat->eidx) {
1005 		clu.dir = hint_stat->clu;
1006 		dentry = hint_stat->eidx;
1007 		end_eidx = dentry;
1008 	}
1009 
1010 	exfat_reset_empty_hint(&ei->hint_femp);
1011 
1012 rewind:
1013 	order = 0;
1014 	step = DIRENT_STEP_FILE;
1015 	exfat_reset_empty_hint(&candi_empty);
1016 
1017 	while (clu.dir != EXFAT_EOF_CLUSTER) {
1018 		i = dentry & (dentries_per_clu - 1);
1019 		for (; i < dentries_per_clu; i++, dentry++) {
1020 			struct exfat_dentry *ep;
1021 			struct buffer_head *bh;
1022 
1023 			if (rewind && dentry == end_eidx)
1024 				goto not_found;
1025 
1026 			ep = exfat_get_dentry(sb, &clu, i, &bh);
1027 			if (!ep)
1028 				return -EIO;
1029 
1030 			entry_type = exfat_get_entry_type(ep);
1031 
1032 			if (entry_type == TYPE_UNUSED ||
1033 			    entry_type == TYPE_DELETED) {
1034 				step = DIRENT_STEP_FILE;
1035 
1036 				exfat_set_empty_hint(ei, &candi_empty, &clu,
1037 						dentry, num_entries,
1038 						entry_type);
1039 
1040 				brelse(bh);
1041 				if (entry_type == TYPE_UNUSED)
1042 					goto not_found;
1043 				continue;
1044 			}
1045 
1046 			exfat_reset_empty_hint(&candi_empty);
1047 
1048 			if (entry_type == TYPE_FILE || entry_type == TYPE_DIR) {
1049 				step = DIRENT_STEP_FILE;
1050 				hint_opt->clu = clu.dir;
1051 				hint_opt->eidx = i;
1052 				num_ext = ep->dentry.file.num_ext;
1053 				step = DIRENT_STEP_STRM;
1054 				brelse(bh);
1055 				continue;
1056 			}
1057 
1058 			if (entry_type == TYPE_STREAM) {
1059 				u16 name_hash;
1060 
1061 				if (step != DIRENT_STEP_STRM) {
1062 					step = DIRENT_STEP_FILE;
1063 					brelse(bh);
1064 					continue;
1065 				}
1066 				step = DIRENT_STEP_FILE;
1067 				name_hash = le16_to_cpu(
1068 						ep->dentry.stream.name_hash);
1069 				if (p_uniname->name_hash == name_hash &&
1070 				    p_uniname->name_len ==
1071 						ep->dentry.stream.name_len) {
1072 					step = DIRENT_STEP_NAME;
1073 					order = 1;
1074 					name_len = 0;
1075 				}
1076 				brelse(bh);
1077 				continue;
1078 			}
1079 
1080 			brelse(bh);
1081 			if (entry_type == TYPE_EXTEND) {
1082 				unsigned short entry_uniname[16], unichar;
1083 
1084 				if (step != DIRENT_STEP_NAME ||
1085 				    name_len >= MAX_NAME_LENGTH) {
1086 					step = DIRENT_STEP_FILE;
1087 					continue;
1088 				}
1089 
1090 				if (++order == 2)
1091 					uniname = p_uniname->name;
1092 				else
1093 					uniname += EXFAT_FILE_NAME_LEN;
1094 
1095 				len = exfat_extract_uni_name(ep, entry_uniname);
1096 				name_len += len;
1097 
1098 				unichar = *(uniname+len);
1099 				*(uniname+len) = 0x0;
1100 
1101 				if (exfat_uniname_ncmp(sb, uniname,
1102 					entry_uniname, len)) {
1103 					step = DIRENT_STEP_FILE;
1104 				} else if (p_uniname->name_len == name_len) {
1105 					if (order == num_ext)
1106 						goto found;
1107 					step = DIRENT_STEP_SECD;
1108 				}
1109 
1110 				*(uniname+len) = unichar;
1111 				continue;
1112 			}
1113 
1114 			if (entry_type &
1115 					(TYPE_CRITICAL_SEC | TYPE_BENIGN_SEC)) {
1116 				if (step == DIRENT_STEP_SECD) {
1117 					if (++order == num_ext)
1118 						goto found;
1119 					continue;
1120 				}
1121 			}
1122 			step = DIRENT_STEP_FILE;
1123 		}
1124 
1125 		if (clu.flags == ALLOC_NO_FAT_CHAIN) {
1126 			if (--clu.size > 0)
1127 				clu.dir++;
1128 			else
1129 				clu.dir = EXFAT_EOF_CLUSTER;
1130 		} else {
1131 			if (exfat_get_next_cluster(sb, &clu.dir))
1132 				return -EIO;
1133 		}
1134 	}
1135 
1136 not_found:
1137 	/*
1138 	 * We started at not 0 index,so we should try to find target
1139 	 * from 0 index to the index we started at.
1140 	 */
1141 	if (!rewind && end_eidx) {
1142 		rewind = 1;
1143 		dentry = 0;
1144 		clu.dir = p_dir->dir;
1145 		goto rewind;
1146 	}
1147 
1148 	/*
1149 	 * set the EXFAT_EOF_CLUSTER flag to avoid search
1150 	 * from the beginning again when allocated a new cluster
1151 	 */
1152 	if (ei->hint_femp.eidx == EXFAT_HINT_NONE) {
1153 		ei->hint_femp.cur.dir = EXFAT_EOF_CLUSTER;
1154 		ei->hint_femp.eidx = p_dir->size * dentries_per_clu;
1155 		ei->hint_femp.count = 0;
1156 	}
1157 
1158 	/* initialized hint_stat */
1159 	hint_stat->clu = p_dir->dir;
1160 	hint_stat->eidx = 0;
1161 	return -ENOENT;
1162 
1163 found:
1164 	/* next dentry we'll find is out of this cluster */
1165 	if (!((dentry + 1) & (dentries_per_clu - 1))) {
1166 		int ret = 0;
1167 
1168 		if (clu.flags == ALLOC_NO_FAT_CHAIN) {
1169 			if (--clu.size > 0)
1170 				clu.dir++;
1171 			else
1172 				clu.dir = EXFAT_EOF_CLUSTER;
1173 		} else {
1174 			ret = exfat_get_next_cluster(sb, &clu.dir);
1175 		}
1176 
1177 		if (ret || clu.dir == EXFAT_EOF_CLUSTER) {
1178 			/* just initialized hint_stat */
1179 			hint_stat->clu = p_dir->dir;
1180 			hint_stat->eidx = 0;
1181 			return (dentry - num_ext);
1182 		}
1183 	}
1184 
1185 	hint_stat->clu = clu.dir;
1186 	hint_stat->eidx = dentry + 1;
1187 	return dentry - num_ext;
1188 }
1189 
exfat_count_ext_entries(struct super_block * sb,struct exfat_chain * p_dir,int entry,struct exfat_dentry * ep)1190 int exfat_count_ext_entries(struct super_block *sb, struct exfat_chain *p_dir,
1191 		int entry, struct exfat_dentry *ep)
1192 {
1193 	int i, count = 0;
1194 	unsigned int type;
1195 	struct exfat_dentry *ext_ep;
1196 	struct buffer_head *bh;
1197 
1198 	for (i = 0, entry++; i < ep->dentry.file.num_ext; i++, entry++) {
1199 		ext_ep = exfat_get_dentry(sb, p_dir, entry, &bh);
1200 		if (!ext_ep)
1201 			return -EIO;
1202 
1203 		type = exfat_get_entry_type(ext_ep);
1204 		brelse(bh);
1205 		if (type & TYPE_CRITICAL_SEC || type & TYPE_BENIGN_SEC)
1206 			count++;
1207 	}
1208 	return count;
1209 }
1210 
exfat_count_dir_entries(struct super_block * sb,struct exfat_chain * p_dir)1211 int exfat_count_dir_entries(struct super_block *sb, struct exfat_chain *p_dir)
1212 {
1213 	int i, count = 0;
1214 	int dentries_per_clu;
1215 	unsigned int entry_type;
1216 	struct exfat_chain clu;
1217 	struct exfat_dentry *ep;
1218 	struct exfat_sb_info *sbi = EXFAT_SB(sb);
1219 	struct buffer_head *bh;
1220 
1221 	dentries_per_clu = sbi->dentries_per_clu;
1222 
1223 	exfat_chain_dup(&clu, p_dir);
1224 
1225 	while (clu.dir != EXFAT_EOF_CLUSTER) {
1226 		for (i = 0; i < dentries_per_clu; i++) {
1227 			ep = exfat_get_dentry(sb, &clu, i, &bh);
1228 			if (!ep)
1229 				return -EIO;
1230 			entry_type = exfat_get_entry_type(ep);
1231 			brelse(bh);
1232 
1233 			if (entry_type == TYPE_UNUSED)
1234 				return count;
1235 			if (entry_type != TYPE_DIR)
1236 				continue;
1237 			count++;
1238 		}
1239 
1240 		if (clu.flags == ALLOC_NO_FAT_CHAIN) {
1241 			if (--clu.size > 0)
1242 				clu.dir++;
1243 			else
1244 				clu.dir = EXFAT_EOF_CLUSTER;
1245 		} else {
1246 			if (exfat_get_next_cluster(sb, &(clu.dir)))
1247 				return -EIO;
1248 		}
1249 	}
1250 
1251 	return count;
1252 }
1253