xref: /kernel/linux/linux-5.10/fs/exfat/namei.c (revision 8c2ecf20)
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
15static inline unsigned long exfat_d_version(struct dentry *dentry)
16{
17	return (unsigned long) dentry->d_fsdata;
18}
19
20static 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 */
34static 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 */
69static unsigned int exfat_striptail_len(unsigned int len, const char *name)
70{
71	while (len && name[len - 1] == '.')
72		len--;
73	return len;
74}
75
76/*
77 * Compute the hash for the exfat name corresponding to the dentry.  If the name
78 * is invalid, we leave the hash code unchanged so that the existing dentry can
79 * be used. The exfat fs routines will return ENOENT or EINVAL as appropriate.
80 */
81static int exfat_d_hash(const struct dentry *dentry, struct qstr *qstr)
82{
83	struct super_block *sb = dentry->d_sb;
84	struct nls_table *t = EXFAT_SB(sb)->nls_io;
85	const unsigned char *name = qstr->name;
86	unsigned int len = exfat_striptail_len(qstr->len, qstr->name);
87	unsigned long hash = init_name_hash(dentry);
88	int i, charlen;
89	wchar_t c;
90
91	for (i = 0; i < len; i += charlen) {
92		charlen = t->char2uni(&name[i], len - i, &c);
93		if (charlen < 0)
94			return charlen;
95		hash = partial_name_hash(exfat_toupper(sb, c), hash);
96	}
97
98	qstr->hash = end_name_hash(hash);
99	return 0;
100}
101
102static int exfat_d_cmp(const struct dentry *dentry, unsigned int len,
103		const char *str, const struct qstr *name)
104{
105	struct super_block *sb = dentry->d_sb;
106	struct nls_table *t = EXFAT_SB(sb)->nls_io;
107	unsigned int alen = exfat_striptail_len(name->len, name->name);
108	unsigned int blen = exfat_striptail_len(len, str);
109	wchar_t c1, c2;
110	int charlen, i;
111
112	if (alen != blen)
113		return 1;
114
115	for (i = 0; i < len; i += charlen) {
116		charlen = t->char2uni(&name->name[i], alen - i, &c1);
117		if (charlen < 0)
118			return 1;
119		if (charlen != t->char2uni(&str[i], blen - i, &c2))
120			return 1;
121
122		if (exfat_toupper(sb, c1) != exfat_toupper(sb, c2))
123			return 1;
124	}
125
126	return 0;
127}
128
129const struct dentry_operations exfat_dentry_ops = {
130	.d_revalidate	= exfat_d_revalidate,
131	.d_hash		= exfat_d_hash,
132	.d_compare	= exfat_d_cmp,
133};
134
135static int exfat_utf8_d_hash(const struct dentry *dentry, struct qstr *qstr)
136{
137	struct super_block *sb = dentry->d_sb;
138	const unsigned char *name = qstr->name;
139	unsigned int len = exfat_striptail_len(qstr->len, qstr->name);
140	unsigned long hash = init_name_hash(dentry);
141	int i, charlen;
142	unicode_t u;
143
144	for (i = 0; i < len; i += charlen) {
145		charlen = utf8_to_utf32(&name[i], len - i, &u);
146		if (charlen < 0)
147			return charlen;
148
149		/*
150		 * exfat_toupper() works only for code points up to the U+FFFF.
151		 */
152		hash = partial_name_hash(u <= 0xFFFF ? exfat_toupper(sb, u) : u,
153					 hash);
154	}
155
156	qstr->hash = end_name_hash(hash);
157	return 0;
158}
159
160static int exfat_utf8_d_cmp(const struct dentry *dentry, unsigned int len,
161		const char *str, const struct qstr *name)
162{
163	struct super_block *sb = dentry->d_sb;
164	unsigned int alen = exfat_striptail_len(name->len, name->name);
165	unsigned int blen = exfat_striptail_len(len, str);
166	unicode_t u_a, u_b;
167	int charlen, i;
168
169	if (alen != blen)
170		return 1;
171
172	for (i = 0; i < alen; i += charlen) {
173		charlen = utf8_to_utf32(&name->name[i], alen - i, &u_a);
174		if (charlen < 0)
175			return 1;
176		if (charlen != utf8_to_utf32(&str[i], blen - i, &u_b))
177			return 1;
178
179		if (u_a <= 0xFFFF && u_b <= 0xFFFF) {
180			if (exfat_toupper(sb, u_a) != exfat_toupper(sb, u_b))
181				return 1;
182		} else {
183			if (u_a != u_b)
184				return 1;
185		}
186	}
187
188	return 0;
189}
190
191const struct dentry_operations exfat_utf8_dentry_ops = {
192	.d_revalidate	= exfat_d_revalidate,
193	.d_hash		= exfat_utf8_d_hash,
194	.d_compare	= exfat_utf8_d_cmp,
195};
196
197/* used only in search empty_slot() */
198#define CNT_UNUSED_NOHIT        (-1)
199#define CNT_UNUSED_HIT          (-2)
200/* search EMPTY CONTINUOUS "num_entries" entries */
201static int exfat_search_empty_slot(struct super_block *sb,
202		struct exfat_hint_femp *hint_femp, struct exfat_chain *p_dir,
203		int num_entries)
204{
205	int i, dentry, num_empty = 0;
206	int dentries_per_clu;
207	unsigned int type;
208	struct exfat_chain clu;
209	struct exfat_dentry *ep;
210	struct exfat_sb_info *sbi = EXFAT_SB(sb);
211	struct buffer_head *bh;
212
213	dentries_per_clu = sbi->dentries_per_clu;
214
215	if (hint_femp->eidx != EXFAT_HINT_NONE) {
216		dentry = hint_femp->eidx;
217		if (num_entries <= hint_femp->count) {
218			hint_femp->eidx = EXFAT_HINT_NONE;
219			return dentry;
220		}
221
222		exfat_chain_dup(&clu, &hint_femp->cur);
223	} else {
224		exfat_chain_dup(&clu, p_dir);
225		dentry = 0;
226	}
227
228	while (clu.dir != EXFAT_EOF_CLUSTER) {
229		i = dentry & (dentries_per_clu - 1);
230
231		for (; i < dentries_per_clu; i++, dentry++) {
232			ep = exfat_get_dentry(sb, &clu, i, &bh, NULL);
233			if (!ep)
234				return -EIO;
235			type = exfat_get_entry_type(ep);
236			brelse(bh);
237
238			if (type == TYPE_UNUSED || type == TYPE_DELETED) {
239				num_empty++;
240				if (hint_femp->eidx == EXFAT_HINT_NONE) {
241					hint_femp->eidx = dentry;
242					hint_femp->count = CNT_UNUSED_NOHIT;
243					exfat_chain_set(&hint_femp->cur,
244						clu.dir, clu.size, clu.flags);
245				}
246
247				if (type == TYPE_UNUSED &&
248				    hint_femp->count != CNT_UNUSED_HIT)
249					hint_femp->count = CNT_UNUSED_HIT;
250			} else {
251				if (hint_femp->eidx != EXFAT_HINT_NONE &&
252				    hint_femp->count == CNT_UNUSED_HIT) {
253					/* unused empty group means
254					 * an empty group which includes
255					 * unused dentry
256					 */
257					exfat_fs_error(sb,
258						"found bogus dentry(%d) beyond unused empty group(%d) (start_clu : %u, cur_clu : %u)",
259						dentry, hint_femp->eidx,
260						p_dir->dir, clu.dir);
261					return -EIO;
262				}
263
264				num_empty = 0;
265				hint_femp->eidx = EXFAT_HINT_NONE;
266			}
267
268			if (num_empty >= num_entries) {
269				/* found and invalidate hint_femp */
270				hint_femp->eidx = EXFAT_HINT_NONE;
271				return (dentry - (num_entries - 1));
272			}
273		}
274
275		if (clu.flags == ALLOC_NO_FAT_CHAIN) {
276			if (--clu.size > 0)
277				clu.dir++;
278			else
279				clu.dir = EXFAT_EOF_CLUSTER;
280		} else {
281			if (exfat_get_next_cluster(sb, &clu.dir))
282				return -EIO;
283		}
284	}
285
286	return -ENOSPC;
287}
288
289static int exfat_check_max_dentries(struct inode *inode)
290{
291	if (EXFAT_B_TO_DEN(i_size_read(inode)) >= MAX_EXFAT_DENTRIES) {
292		/*
293		 * exFAT spec allows a dir to grow up to 8388608(256MB)
294		 * dentries
295		 */
296		return -ENOSPC;
297	}
298	return 0;
299}
300
301/* find empty directory entry.
302 * if there isn't any empty slot, expand cluster chain.
303 */
304static int exfat_find_empty_entry(struct inode *inode,
305		struct exfat_chain *p_dir, int num_entries)
306{
307	int dentry;
308	unsigned int ret, last_clu;
309	sector_t sector;
310	loff_t size = 0;
311	struct exfat_chain clu;
312	struct exfat_dentry *ep = NULL;
313	struct super_block *sb = inode->i_sb;
314	struct exfat_sb_info *sbi = EXFAT_SB(sb);
315	struct exfat_inode_info *ei = EXFAT_I(inode);
316	struct exfat_hint_femp hint_femp;
317
318	hint_femp.eidx = EXFAT_HINT_NONE;
319
320	if (ei->hint_femp.eidx != EXFAT_HINT_NONE) {
321		hint_femp = ei->hint_femp;
322		ei->hint_femp.eidx = EXFAT_HINT_NONE;
323	}
324
325	while ((dentry = exfat_search_empty_slot(sb, &hint_femp, p_dir,
326					num_entries)) < 0) {
327		if (dentry == -EIO)
328			break;
329
330		if (exfat_check_max_dentries(inode))
331			return -ENOSPC;
332
333		/*
334		 * Allocate new cluster to this directory
335		 */
336		if (ei->start_clu != EXFAT_EOF_CLUSTER) {
337			/* we trust p_dir->size regardless of FAT type */
338			if (exfat_find_last_cluster(sb, p_dir, &last_clu))
339				return -EIO;
340
341			exfat_chain_set(&clu, last_clu + 1, 0, p_dir->flags);
342		} else {
343			/* This directory is empty */
344			exfat_chain_set(&clu, EXFAT_EOF_CLUSTER, 0,
345					ALLOC_NO_FAT_CHAIN);
346		}
347
348		/* allocate a cluster */
349		ret = exfat_alloc_cluster(inode, 1, &clu);
350		if (ret)
351			return ret;
352
353		if (exfat_zeroed_cluster(inode, clu.dir))
354			return -EIO;
355
356		if (ei->start_clu == EXFAT_EOF_CLUSTER) {
357			ei->start_clu = clu.dir;
358			p_dir->dir = clu.dir;
359		}
360
361		/* append to the FAT chain */
362		if (clu.flags != p_dir->flags) {
363			/* no-fat-chain bit is disabled,
364			 * so fat-chain should be synced with alloc-bitmap
365			 */
366			exfat_chain_cont_cluster(sb, p_dir->dir, p_dir->size);
367			p_dir->flags = ALLOC_FAT_CHAIN;
368			hint_femp.cur.flags = ALLOC_FAT_CHAIN;
369		}
370
371		if (clu.flags == ALLOC_FAT_CHAIN)
372			if (exfat_ent_set(sb, last_clu, clu.dir))
373				return -EIO;
374
375		if (hint_femp.eidx == EXFAT_HINT_NONE) {
376			/* the special case that new dentry
377			 * should be allocated from the start of new cluster
378			 */
379			hint_femp.eidx = EXFAT_B_TO_DEN_IDX(p_dir->size, sbi);
380			hint_femp.count = sbi->dentries_per_clu;
381
382			exfat_chain_set(&hint_femp.cur, clu.dir, 0, clu.flags);
383		}
384		hint_femp.cur.size++;
385		p_dir->size++;
386		size = EXFAT_CLU_TO_B(p_dir->size, sbi);
387
388		/* update the directory entry */
389		if (p_dir->dir != sbi->root_dir) {
390			struct buffer_head *bh;
391
392			ep = exfat_get_dentry(sb,
393				&(ei->dir), ei->entry + 1, &bh, &sector);
394			if (!ep)
395				return -EIO;
396
397			ep->dentry.stream.valid_size = cpu_to_le64(size);
398			ep->dentry.stream.size = ep->dentry.stream.valid_size;
399			ep->dentry.stream.flags = p_dir->flags;
400			exfat_update_bh(bh, IS_DIRSYNC(inode));
401			brelse(bh);
402			if (exfat_update_dir_chksum(inode, &(ei->dir),
403			    ei->entry))
404				return -EIO;
405		}
406
407		/* directory inode should be updated in here */
408		i_size_write(inode, size);
409		ei->i_size_ondisk += sbi->cluster_size;
410		ei->i_size_aligned += sbi->cluster_size;
411		ei->flags = p_dir->flags;
412		inode->i_blocks += sbi->cluster_size >> 9;
413	}
414
415	return dentry;
416}
417
418/*
419 * Name Resolution Functions :
420 * Zero if it was successful; otherwise nonzero.
421 */
422static int __exfat_resolve_path(struct inode *inode, const unsigned char *path,
423		struct exfat_chain *p_dir, struct exfat_uni_name *p_uniname,
424		int lookup)
425{
426	int namelen;
427	int lossy = NLS_NAME_NO_LOSSY;
428	struct super_block *sb = inode->i_sb;
429	struct exfat_sb_info *sbi = EXFAT_SB(sb);
430	struct exfat_inode_info *ei = EXFAT_I(inode);
431
432	/* strip all trailing periods */
433	namelen = exfat_striptail_len(strlen(path), path);
434	if (!namelen)
435		return -ENOENT;
436
437	if (strlen(path) > (MAX_NAME_LENGTH * MAX_CHARSET_SIZE))
438		return -ENAMETOOLONG;
439
440	/*
441	 * strip all leading spaces :
442	 * "MS windows 7" supports leading spaces.
443	 * So we should skip this preprocessing for compatibility.
444	 */
445
446	/* file name conversion :
447	 * If lookup case, we allow bad-name for compatibility.
448	 */
449	namelen = exfat_nls_to_utf16(sb, path, namelen, p_uniname,
450			&lossy);
451	if (namelen < 0)
452		return namelen; /* return error value */
453
454	if ((lossy && !lookup) || !namelen)
455		return -EINVAL;
456
457	exfat_chain_set(p_dir, ei->start_clu,
458		EXFAT_B_TO_CLU(i_size_read(inode), sbi), ei->flags);
459
460	return 0;
461}
462
463static inline int exfat_resolve_path(struct inode *inode,
464		const unsigned char *path, struct exfat_chain *dir,
465		struct exfat_uni_name *uni)
466{
467	return __exfat_resolve_path(inode, path, dir, uni, 0);
468}
469
470static inline int exfat_resolve_path_for_lookup(struct inode *inode,
471		const unsigned char *path, struct exfat_chain *dir,
472		struct exfat_uni_name *uni)
473{
474	return __exfat_resolve_path(inode, path, dir, uni, 1);
475}
476
477static inline loff_t exfat_make_i_pos(struct exfat_dir_entry *info)
478{
479	return ((loff_t) info->dir.dir << 32) | (info->entry & 0xffffffff);
480}
481
482static int exfat_add_entry(struct inode *inode, const char *path,
483		struct exfat_chain *p_dir, unsigned int type,
484		struct exfat_dir_entry *info)
485{
486	int ret, dentry, num_entries;
487	struct super_block *sb = inode->i_sb;
488	struct exfat_sb_info *sbi = EXFAT_SB(sb);
489	struct exfat_uni_name uniname;
490	struct exfat_chain clu;
491	int clu_size = 0;
492	unsigned int start_clu = EXFAT_FREE_CLUSTER;
493
494	ret = exfat_resolve_path(inode, path, p_dir, &uniname);
495	if (ret)
496		goto out;
497
498	num_entries = exfat_calc_num_entries(&uniname);
499	if (num_entries < 0) {
500		ret = num_entries;
501		goto out;
502	}
503
504	/* exfat_find_empty_entry must be called before alloc_cluster() */
505	dentry = exfat_find_empty_entry(inode, p_dir, num_entries);
506	if (dentry < 0) {
507		ret = dentry; /* -EIO or -ENOSPC */
508		goto out;
509	}
510
511	if (type == TYPE_DIR) {
512		ret = exfat_alloc_new_dir(inode, &clu);
513		if (ret)
514			goto out;
515		start_clu = clu.dir;
516		clu_size = sbi->cluster_size;
517	}
518
519	/* update the directory entry */
520	/* fill the dos name directory entry information of the created file.
521	 * the first cluster is not determined yet. (0)
522	 */
523	ret = exfat_init_dir_entry(inode, p_dir, dentry, type,
524		start_clu, clu_size);
525	if (ret)
526		goto out;
527
528	ret = exfat_init_ext_entry(inode, p_dir, dentry, num_entries, &uniname);
529	if (ret)
530		goto out;
531
532	info->dir = *p_dir;
533	info->entry = dentry;
534	info->flags = ALLOC_NO_FAT_CHAIN;
535	info->type = type;
536
537	if (type == TYPE_FILE) {
538		info->attr = ATTR_ARCHIVE;
539		info->start_clu = EXFAT_EOF_CLUSTER;
540		info->size = 0;
541		info->num_subdirs = 0;
542	} else {
543		info->attr = ATTR_SUBDIR;
544		info->start_clu = start_clu;
545		info->size = clu_size;
546		info->num_subdirs = EXFAT_MIN_SUBDIR;
547	}
548	memset(&info->crtime, 0, sizeof(info->crtime));
549	memset(&info->mtime, 0, sizeof(info->mtime));
550	memset(&info->atime, 0, sizeof(info->atime));
551out:
552	return ret;
553}
554
555static int exfat_create(struct inode *dir, struct dentry *dentry, umode_t mode,
556		bool excl)
557{
558	struct super_block *sb = dir->i_sb;
559	struct inode *inode;
560	struct exfat_chain cdir;
561	struct exfat_dir_entry info;
562	loff_t i_pos;
563	int err;
564
565	mutex_lock(&EXFAT_SB(sb)->s_lock);
566	exfat_set_volume_dirty(sb);
567	err = exfat_add_entry(dir, dentry->d_name.name, &cdir, TYPE_FILE,
568		&info);
569	exfat_clear_volume_dirty(sb);
570	if (err)
571		goto unlock;
572
573	inode_inc_iversion(dir);
574	dir->i_ctime = dir->i_mtime = current_time(dir);
575	if (IS_DIRSYNC(dir))
576		exfat_sync_inode(dir);
577	else
578		mark_inode_dirty(dir);
579
580	i_pos = exfat_make_i_pos(&info);
581	inode = exfat_build_inode(sb, &info, i_pos);
582	err = PTR_ERR_OR_ZERO(inode);
583	if (err)
584		goto unlock;
585
586	inode_inc_iversion(inode);
587	inode->i_mtime = inode->i_atime = inode->i_ctime =
588		EXFAT_I(inode)->i_crtime = current_time(inode);
589	exfat_truncate_atime(&inode->i_atime);
590	/* timestamp is already written, so mark_inode_dirty() is unneeded. */
591
592	d_instantiate(dentry, inode);
593unlock:
594	mutex_unlock(&EXFAT_SB(sb)->s_lock);
595	return err;
596}
597
598/* lookup a file */
599static int exfat_find(struct inode *dir, struct qstr *qname,
600		struct exfat_dir_entry *info)
601{
602	int ret, dentry, num_entries, count;
603	struct exfat_chain cdir;
604	struct exfat_uni_name uni_name;
605	struct super_block *sb = dir->i_sb;
606	struct exfat_sb_info *sbi = EXFAT_SB(sb);
607	struct exfat_inode_info *ei = EXFAT_I(dir);
608	struct exfat_dentry *ep, *ep2;
609	struct exfat_entry_set_cache *es;
610	/* for optimized dir & entry to prevent long traverse of cluster chain */
611	struct exfat_hint hint_opt;
612
613	if (qname->len == 0)
614		return -ENOENT;
615
616	/* check the validity of directory name in the given pathname */
617	ret = exfat_resolve_path_for_lookup(dir, qname->name, &cdir, &uni_name);
618	if (ret)
619		return ret;
620
621	num_entries = exfat_calc_num_entries(&uni_name);
622	if (num_entries < 0)
623		return num_entries;
624
625	/* check the validation of hint_stat and initialize it if required */
626	if (ei->version != (inode_peek_iversion_raw(dir) & 0xffffffff)) {
627		ei->hint_stat.clu = cdir.dir;
628		ei->hint_stat.eidx = 0;
629		ei->version = (inode_peek_iversion_raw(dir) & 0xffffffff);
630		ei->hint_femp.eidx = EXFAT_HINT_NONE;
631	}
632
633	/* search the file name for directories */
634	dentry = exfat_find_dir_entry(sb, ei, &cdir, &uni_name,
635			num_entries, TYPE_ALL, &hint_opt);
636
637	if (dentry < 0)
638		return dentry; /* -error value */
639
640	info->dir = cdir;
641	info->entry = dentry;
642	info->num_subdirs = 0;
643
644	/* adjust cdir to the optimized value */
645	cdir.dir = hint_opt.clu;
646	if (cdir.flags & ALLOC_NO_FAT_CHAIN)
647		cdir.size -= dentry / sbi->dentries_per_clu;
648	dentry = hint_opt.eidx;
649	es = exfat_get_dentry_set(sb, &cdir, dentry, ES_2_ENTRIES);
650	if (!es)
651		return -EIO;
652	ep = exfat_get_dentry_cached(es, 0);
653	ep2 = exfat_get_dentry_cached(es, 1);
654
655	info->type = exfat_get_entry_type(ep);
656	info->attr = le16_to_cpu(ep->dentry.file.attr);
657	info->size = le64_to_cpu(ep2->dentry.stream.valid_size);
658	if (info->size == 0) {
659		info->flags = ALLOC_NO_FAT_CHAIN;
660		info->start_clu = EXFAT_EOF_CLUSTER;
661	} else {
662		info->flags = ep2->dentry.stream.flags;
663		info->start_clu =
664			le32_to_cpu(ep2->dentry.stream.start_clu);
665	}
666
667	exfat_get_entry_time(sbi, &info->crtime,
668			     ep->dentry.file.create_tz,
669			     ep->dentry.file.create_time,
670			     ep->dentry.file.create_date,
671			     ep->dentry.file.create_time_cs);
672	exfat_get_entry_time(sbi, &info->mtime,
673			     ep->dentry.file.modify_tz,
674			     ep->dentry.file.modify_time,
675			     ep->dentry.file.modify_date,
676			     ep->dentry.file.modify_time_cs);
677	exfat_get_entry_time(sbi, &info->atime,
678			     ep->dentry.file.access_tz,
679			     ep->dentry.file.access_time,
680			     ep->dentry.file.access_date,
681			     0);
682	exfat_free_dentry_set(es, false);
683
684	if (ei->start_clu == EXFAT_FREE_CLUSTER) {
685		exfat_fs_error(sb,
686			       "non-zero size file starts with zero cluster (size : %llu, p_dir : %u, entry : 0x%08x)",
687			       i_size_read(dir), ei->dir.dir, ei->entry);
688		return -EIO;
689	}
690
691	if (info->type == TYPE_DIR) {
692		exfat_chain_set(&cdir, info->start_clu,
693				EXFAT_B_TO_CLU(info->size, sbi), info->flags);
694		count = exfat_count_dir_entries(sb, &cdir);
695		if (count < 0)
696			return -EIO;
697
698		info->num_subdirs = count + EXFAT_MIN_SUBDIR;
699	}
700	return 0;
701}
702
703static int exfat_d_anon_disconn(struct dentry *dentry)
704{
705	return IS_ROOT(dentry) && (dentry->d_flags & DCACHE_DISCONNECTED);
706}
707
708static struct dentry *exfat_lookup(struct inode *dir, struct dentry *dentry,
709		unsigned int flags)
710{
711	struct super_block *sb = dir->i_sb;
712	struct inode *inode;
713	struct dentry *alias;
714	struct exfat_dir_entry info;
715	int err;
716	loff_t i_pos;
717	mode_t i_mode;
718
719	mutex_lock(&EXFAT_SB(sb)->s_lock);
720	err = exfat_find(dir, &dentry->d_name, &info);
721	if (err) {
722		if (err == -ENOENT) {
723			inode = NULL;
724			goto out;
725		}
726		goto unlock;
727	}
728
729	i_pos = exfat_make_i_pos(&info);
730	inode = exfat_build_inode(sb, &info, i_pos);
731	err = PTR_ERR_OR_ZERO(inode);
732	if (err)
733		goto unlock;
734
735	i_mode = inode->i_mode;
736	alias = d_find_alias(inode);
737
738	/*
739	 * Checking "alias->d_parent == dentry->d_parent" to make sure
740	 * FS is not corrupted (especially double linked dir).
741	 */
742	if (alias && alias->d_parent == dentry->d_parent &&
743			!exfat_d_anon_disconn(alias)) {
744
745		/*
746		 * Unhashed alias is able to exist because of revalidate()
747		 * called by lookup_fast. You can easily make this status
748		 * by calling create and lookup concurrently
749		 * In such case, we reuse an alias instead of new dentry
750		 */
751		if (d_unhashed(alias)) {
752			WARN_ON(alias->d_name.hash_len !=
753				dentry->d_name.hash_len);
754			exfat_info(sb, "rehashed a dentry(%p) in read lookup",
755				   alias);
756			d_drop(dentry);
757			d_rehash(alias);
758		} else if (!S_ISDIR(i_mode)) {
759			/*
760			 * This inode has non anonymous-DCACHE_DISCONNECTED
761			 * dentry. This means, the user did ->lookup() by an
762			 * another name (longname vs 8.3 alias of it) in past.
763			 *
764			 * Switch to new one for reason of locality if possible.
765			 */
766			d_move(alias, dentry);
767		}
768		iput(inode);
769		mutex_unlock(&EXFAT_SB(sb)->s_lock);
770		return alias;
771	}
772	dput(alias);
773out:
774	mutex_unlock(&EXFAT_SB(sb)->s_lock);
775	if (!inode)
776		exfat_d_version_set(dentry, inode_query_iversion(dir));
777
778	return d_splice_alias(inode, dentry);
779unlock:
780	mutex_unlock(&EXFAT_SB(sb)->s_lock);
781	return ERR_PTR(err);
782}
783
784/* remove an entry, BUT don't truncate */
785static int exfat_unlink(struct inode *dir, struct dentry *dentry)
786{
787	struct exfat_chain cdir;
788	struct exfat_dentry *ep;
789	struct super_block *sb = dir->i_sb;
790	struct inode *inode = dentry->d_inode;
791	struct exfat_inode_info *ei = EXFAT_I(inode);
792	struct buffer_head *bh;
793	sector_t sector;
794	int num_entries, entry, err = 0;
795
796	mutex_lock(&EXFAT_SB(sb)->s_lock);
797	exfat_chain_dup(&cdir, &ei->dir);
798	entry = ei->entry;
799	if (ei->dir.dir == DIR_DELETED) {
800		exfat_err(sb, "abnormal access to deleted dentry");
801		err = -ENOENT;
802		goto unlock;
803	}
804
805	ep = exfat_get_dentry(sb, &cdir, entry, &bh, &sector);
806	if (!ep) {
807		err = -EIO;
808		goto unlock;
809	}
810	num_entries = exfat_count_ext_entries(sb, &cdir, entry, ep);
811	if (num_entries < 0) {
812		err = -EIO;
813		brelse(bh);
814		goto unlock;
815	}
816	num_entries++;
817	brelse(bh);
818
819	exfat_set_volume_dirty(sb);
820	/* update the directory entry */
821	if (exfat_remove_entries(dir, &cdir, entry, 0, num_entries)) {
822		err = -EIO;
823		goto unlock;
824	}
825
826	/* This doesn't modify ei */
827	ei->dir.dir = DIR_DELETED;
828	exfat_clear_volume_dirty(sb);
829
830	inode_inc_iversion(dir);
831	dir->i_mtime = dir->i_atime = current_time(dir);
832	exfat_truncate_atime(&dir->i_atime);
833	if (IS_DIRSYNC(dir))
834		exfat_sync_inode(dir);
835	else
836		mark_inode_dirty(dir);
837
838	clear_nlink(inode);
839	inode->i_mtime = inode->i_atime = current_time(inode);
840	exfat_truncate_atime(&inode->i_atime);
841	exfat_unhash_inode(inode);
842	exfat_d_version_set(dentry, inode_query_iversion(dir));
843unlock:
844	mutex_unlock(&EXFAT_SB(sb)->s_lock);
845	return err;
846}
847
848static int exfat_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
849{
850	struct super_block *sb = dir->i_sb;
851	struct inode *inode;
852	struct exfat_dir_entry info;
853	struct exfat_chain cdir;
854	loff_t i_pos;
855	int err;
856
857	mutex_lock(&EXFAT_SB(sb)->s_lock);
858	exfat_set_volume_dirty(sb);
859	err = exfat_add_entry(dir, dentry->d_name.name, &cdir, TYPE_DIR,
860		&info);
861	exfat_clear_volume_dirty(sb);
862	if (err)
863		goto unlock;
864
865	inode_inc_iversion(dir);
866	dir->i_ctime = dir->i_mtime = current_time(dir);
867	if (IS_DIRSYNC(dir))
868		exfat_sync_inode(dir);
869	else
870		mark_inode_dirty(dir);
871	inc_nlink(dir);
872
873	i_pos = exfat_make_i_pos(&info);
874	inode = exfat_build_inode(sb, &info, i_pos);
875	err = PTR_ERR_OR_ZERO(inode);
876	if (err)
877		goto unlock;
878
879	inode_inc_iversion(inode);
880	inode->i_mtime = inode->i_atime = inode->i_ctime =
881		EXFAT_I(inode)->i_crtime = current_time(inode);
882	exfat_truncate_atime(&inode->i_atime);
883	/* timestamp is already written, so mark_inode_dirty() is unneeded. */
884
885	d_instantiate(dentry, inode);
886
887unlock:
888	mutex_unlock(&EXFAT_SB(sb)->s_lock);
889	return err;
890}
891
892static int exfat_check_dir_empty(struct super_block *sb,
893		struct exfat_chain *p_dir)
894{
895	int i, dentries_per_clu;
896	unsigned int type;
897	struct exfat_chain clu;
898	struct exfat_dentry *ep;
899	struct exfat_sb_info *sbi = EXFAT_SB(sb);
900	struct buffer_head *bh;
901
902	dentries_per_clu = sbi->dentries_per_clu;
903
904	if (p_dir->dir == EXFAT_EOF_CLUSTER)
905		return 0;
906
907	exfat_chain_dup(&clu, p_dir);
908
909	while (clu.dir != EXFAT_EOF_CLUSTER) {
910		for (i = 0; i < dentries_per_clu; i++) {
911			ep = exfat_get_dentry(sb, &clu, i, &bh, NULL);
912			if (!ep)
913				return -EIO;
914			type = exfat_get_entry_type(ep);
915			brelse(bh);
916			if (type == TYPE_UNUSED)
917				return 0;
918
919			if (type != TYPE_FILE && type != TYPE_DIR)
920				continue;
921
922			return -ENOTEMPTY;
923		}
924
925		if (clu.flags == ALLOC_NO_FAT_CHAIN) {
926			if (--clu.size > 0)
927				clu.dir++;
928			else
929				clu.dir = EXFAT_EOF_CLUSTER;
930		} else {
931			if (exfat_get_next_cluster(sb, &(clu.dir)))
932				return -EIO;
933		}
934	}
935
936	return 0;
937}
938
939static int exfat_rmdir(struct inode *dir, struct dentry *dentry)
940{
941	struct inode *inode = dentry->d_inode;
942	struct exfat_dentry *ep;
943	struct exfat_chain cdir, clu_to_free;
944	struct super_block *sb = inode->i_sb;
945	struct exfat_sb_info *sbi = EXFAT_SB(sb);
946	struct exfat_inode_info *ei = EXFAT_I(inode);
947	struct buffer_head *bh;
948	sector_t sector;
949	int num_entries, entry, err;
950
951	mutex_lock(&EXFAT_SB(inode->i_sb)->s_lock);
952
953	exfat_chain_dup(&cdir, &ei->dir);
954	entry = ei->entry;
955
956	if (ei->dir.dir == DIR_DELETED) {
957		exfat_err(sb, "abnormal access to deleted dentry");
958		err = -ENOENT;
959		goto unlock;
960	}
961
962	exfat_chain_set(&clu_to_free, ei->start_clu,
963		EXFAT_B_TO_CLU_ROUND_UP(i_size_read(inode), sbi), ei->flags);
964
965	err = exfat_check_dir_empty(sb, &clu_to_free);
966	if (err) {
967		if (err == -EIO)
968			exfat_err(sb, "failed to exfat_check_dir_empty : err(%d)",
969				  err);
970		goto unlock;
971	}
972
973	ep = exfat_get_dentry(sb, &cdir, entry, &bh, &sector);
974	if (!ep) {
975		err = -EIO;
976		goto unlock;
977	}
978
979	num_entries = exfat_count_ext_entries(sb, &cdir, entry, ep);
980	if (num_entries < 0) {
981		err = -EIO;
982		brelse(bh);
983		goto unlock;
984	}
985	num_entries++;
986	brelse(bh);
987
988	exfat_set_volume_dirty(sb);
989	err = exfat_remove_entries(dir, &cdir, entry, 0, num_entries);
990	if (err) {
991		exfat_err(sb, "failed to exfat_remove_entries : err(%d)", err);
992		goto unlock;
993	}
994	ei->dir.dir = DIR_DELETED;
995	exfat_clear_volume_dirty(sb);
996
997	inode_inc_iversion(dir);
998	dir->i_mtime = dir->i_atime = current_time(dir);
999	exfat_truncate_atime(&dir->i_atime);
1000	if (IS_DIRSYNC(dir))
1001		exfat_sync_inode(dir);
1002	else
1003		mark_inode_dirty(dir);
1004	drop_nlink(dir);
1005
1006	clear_nlink(inode);
1007	inode->i_mtime = inode->i_atime = current_time(inode);
1008	exfat_truncate_atime(&inode->i_atime);
1009	exfat_unhash_inode(inode);
1010	exfat_d_version_set(dentry, inode_query_iversion(dir));
1011unlock:
1012	mutex_unlock(&EXFAT_SB(inode->i_sb)->s_lock);
1013	return err;
1014}
1015
1016static int exfat_rename_file(struct inode *inode, struct exfat_chain *p_dir,
1017		int oldentry, struct exfat_uni_name *p_uniname,
1018		struct exfat_inode_info *ei)
1019{
1020	int ret, num_old_entries, num_new_entries;
1021	sector_t sector_old, sector_new;
1022	struct exfat_dentry *epold, *epnew;
1023	struct super_block *sb = inode->i_sb;
1024	struct buffer_head *new_bh, *old_bh;
1025	int sync = IS_DIRSYNC(inode);
1026
1027	epold = exfat_get_dentry(sb, p_dir, oldentry, &old_bh, &sector_old);
1028	if (!epold)
1029		return -EIO;
1030
1031	num_old_entries = exfat_count_ext_entries(sb, p_dir, oldentry, epold);
1032	if (num_old_entries < 0)
1033		return -EIO;
1034	num_old_entries++;
1035
1036	num_new_entries = exfat_calc_num_entries(p_uniname);
1037	if (num_new_entries < 0)
1038		return num_new_entries;
1039
1040	if (num_old_entries < num_new_entries) {
1041		int newentry;
1042
1043		newentry =
1044			exfat_find_empty_entry(inode, p_dir, num_new_entries);
1045		if (newentry < 0)
1046			return newentry; /* -EIO or -ENOSPC */
1047
1048		epnew = exfat_get_dentry(sb, p_dir, newentry, &new_bh,
1049			&sector_new);
1050		if (!epnew)
1051			return -EIO;
1052
1053		*epnew = *epold;
1054		if (exfat_get_entry_type(epnew) == TYPE_FILE) {
1055			epnew->dentry.file.attr |= cpu_to_le16(ATTR_ARCHIVE);
1056			ei->attr |= ATTR_ARCHIVE;
1057		}
1058		exfat_update_bh(new_bh, sync);
1059		brelse(old_bh);
1060		brelse(new_bh);
1061
1062		epold = exfat_get_dentry(sb, p_dir, oldentry + 1, &old_bh,
1063			&sector_old);
1064		if (!epold)
1065			return -EIO;
1066		epnew = exfat_get_dentry(sb, p_dir, newentry + 1, &new_bh,
1067			&sector_new);
1068		if (!epnew) {
1069			brelse(old_bh);
1070			return -EIO;
1071		}
1072
1073		*epnew = *epold;
1074		exfat_update_bh(new_bh, sync);
1075		brelse(old_bh);
1076		brelse(new_bh);
1077
1078		ret = exfat_init_ext_entry(inode, p_dir, newentry,
1079			num_new_entries, p_uniname);
1080		if (ret)
1081			return ret;
1082
1083		exfat_remove_entries(inode, p_dir, oldentry, 0,
1084			num_old_entries);
1085		ei->entry = newentry;
1086	} else {
1087		if (exfat_get_entry_type(epold) == TYPE_FILE) {
1088			epold->dentry.file.attr |= cpu_to_le16(ATTR_ARCHIVE);
1089			ei->attr |= ATTR_ARCHIVE;
1090		}
1091		exfat_update_bh(old_bh, sync);
1092		brelse(old_bh);
1093		ret = exfat_init_ext_entry(inode, p_dir, oldentry,
1094			num_new_entries, p_uniname);
1095		if (ret)
1096			return ret;
1097
1098		exfat_remove_entries(inode, p_dir, oldentry, num_new_entries,
1099			num_old_entries);
1100	}
1101	return 0;
1102}
1103
1104static int exfat_move_file(struct inode *inode, struct exfat_chain *p_olddir,
1105		int oldentry, struct exfat_chain *p_newdir,
1106		struct exfat_uni_name *p_uniname, struct exfat_inode_info *ei)
1107{
1108	int ret, newentry, num_new_entries, num_old_entries;
1109	sector_t sector_mov, sector_new;
1110	struct exfat_dentry *epmov, *epnew;
1111	struct super_block *sb = inode->i_sb;
1112	struct buffer_head *mov_bh, *new_bh;
1113
1114	epmov = exfat_get_dentry(sb, p_olddir, oldentry, &mov_bh, &sector_mov);
1115	if (!epmov)
1116		return -EIO;
1117
1118	num_old_entries = exfat_count_ext_entries(sb, p_olddir, oldentry,
1119		epmov);
1120	if (num_old_entries < 0)
1121		return -EIO;
1122	num_old_entries++;
1123
1124	num_new_entries = exfat_calc_num_entries(p_uniname);
1125	if (num_new_entries < 0)
1126		return num_new_entries;
1127
1128	newentry = exfat_find_empty_entry(inode, p_newdir, num_new_entries);
1129	if (newentry < 0)
1130		return newentry; /* -EIO or -ENOSPC */
1131
1132	epnew = exfat_get_dentry(sb, p_newdir, newentry, &new_bh, &sector_new);
1133	if (!epnew)
1134		return -EIO;
1135
1136	*epnew = *epmov;
1137	if (exfat_get_entry_type(epnew) == TYPE_FILE) {
1138		epnew->dentry.file.attr |= cpu_to_le16(ATTR_ARCHIVE);
1139		ei->attr |= ATTR_ARCHIVE;
1140	}
1141	exfat_update_bh(new_bh, IS_DIRSYNC(inode));
1142	brelse(mov_bh);
1143	brelse(new_bh);
1144
1145	epmov = exfat_get_dentry(sb, p_olddir, oldentry + 1, &mov_bh,
1146		&sector_mov);
1147	if (!epmov)
1148		return -EIO;
1149	epnew = exfat_get_dentry(sb, p_newdir, newentry + 1, &new_bh,
1150		&sector_new);
1151	if (!epnew) {
1152		brelse(mov_bh);
1153		return -EIO;
1154	}
1155
1156	*epnew = *epmov;
1157	exfat_update_bh(new_bh, IS_DIRSYNC(inode));
1158	brelse(mov_bh);
1159	brelse(new_bh);
1160
1161	ret = exfat_init_ext_entry(inode, p_newdir, newentry, num_new_entries,
1162		p_uniname);
1163	if (ret)
1164		return ret;
1165
1166	exfat_remove_entries(inode, p_olddir, oldentry, 0, num_old_entries);
1167
1168	exfat_chain_set(&ei->dir, p_newdir->dir, p_newdir->size,
1169		p_newdir->flags);
1170
1171	ei->entry = newentry;
1172	return 0;
1173}
1174
1175static void exfat_update_parent_info(struct exfat_inode_info *ei,
1176		struct inode *parent_inode)
1177{
1178	struct exfat_sb_info *sbi = EXFAT_SB(parent_inode->i_sb);
1179	struct exfat_inode_info *parent_ei = EXFAT_I(parent_inode);
1180	loff_t parent_isize = i_size_read(parent_inode);
1181
1182	/*
1183	 * the problem that struct exfat_inode_info caches wrong parent info.
1184	 *
1185	 * because of flag-mismatch of ei->dir,
1186	 * there is abnormal traversing cluster chain.
1187	 */
1188	if (unlikely(parent_ei->flags != ei->dir.flags ||
1189		     parent_isize != EXFAT_CLU_TO_B(ei->dir.size, sbi) ||
1190		     parent_ei->start_clu != ei->dir.dir)) {
1191		exfat_chain_set(&ei->dir, parent_ei->start_clu,
1192			EXFAT_B_TO_CLU_ROUND_UP(parent_isize, sbi),
1193			parent_ei->flags);
1194	}
1195}
1196
1197/* rename or move a old file into a new file */
1198static int __exfat_rename(struct inode *old_parent_inode,
1199		struct exfat_inode_info *ei, struct inode *new_parent_inode,
1200		struct dentry *new_dentry)
1201{
1202	int ret;
1203	int dentry;
1204	struct exfat_chain olddir, newdir;
1205	struct exfat_chain *p_dir = NULL;
1206	struct exfat_uni_name uni_name;
1207	struct exfat_dentry *ep;
1208	struct super_block *sb = old_parent_inode->i_sb;
1209	struct exfat_sb_info *sbi = EXFAT_SB(sb);
1210	const unsigned char *new_path = new_dentry->d_name.name;
1211	struct inode *new_inode = new_dentry->d_inode;
1212	int num_entries;
1213	struct exfat_inode_info *new_ei = NULL;
1214	unsigned int new_entry_type = TYPE_UNUSED;
1215	int new_entry = 0;
1216	struct buffer_head *old_bh, *new_bh = NULL;
1217
1218	/* check the validity of pointer parameters */
1219	if (new_path == NULL || strlen(new_path) == 0)
1220		return -EINVAL;
1221
1222	if (ei->dir.dir == DIR_DELETED) {
1223		exfat_err(sb, "abnormal access to deleted source dentry");
1224		return -ENOENT;
1225	}
1226
1227	exfat_update_parent_info(ei, old_parent_inode);
1228
1229	exfat_chain_dup(&olddir, &ei->dir);
1230	dentry = ei->entry;
1231
1232	ep = exfat_get_dentry(sb, &olddir, dentry, &old_bh, NULL);
1233	if (!ep) {
1234		ret = -EIO;
1235		goto out;
1236	}
1237	brelse(old_bh);
1238
1239	/* check whether new dir is existing directory and empty */
1240	if (new_inode) {
1241		ret = -EIO;
1242		new_ei = EXFAT_I(new_inode);
1243
1244		if (new_ei->dir.dir == DIR_DELETED) {
1245			exfat_err(sb, "abnormal access to deleted target dentry");
1246			goto out;
1247		}
1248
1249		exfat_update_parent_info(new_ei, new_parent_inode);
1250
1251		p_dir = &(new_ei->dir);
1252		new_entry = new_ei->entry;
1253		ep = exfat_get_dentry(sb, p_dir, new_entry, &new_bh, NULL);
1254		if (!ep)
1255			goto out;
1256
1257		new_entry_type = exfat_get_entry_type(ep);
1258		brelse(new_bh);
1259
1260		/* if new_inode exists, update ei */
1261		if (new_entry_type == TYPE_DIR) {
1262			struct exfat_chain new_clu;
1263
1264			new_clu.dir = new_ei->start_clu;
1265			new_clu.size =
1266				EXFAT_B_TO_CLU_ROUND_UP(i_size_read(new_inode),
1267				sbi);
1268			new_clu.flags = new_ei->flags;
1269
1270			ret = exfat_check_dir_empty(sb, &new_clu);
1271			if (ret)
1272				goto out;
1273		}
1274	}
1275
1276	/* check the validity of directory name in the given new pathname */
1277	ret = exfat_resolve_path(new_parent_inode, new_path, &newdir,
1278			&uni_name);
1279	if (ret)
1280		goto out;
1281
1282	exfat_set_volume_dirty(sb);
1283
1284	if (olddir.dir == newdir.dir)
1285		ret = exfat_rename_file(new_parent_inode, &olddir, dentry,
1286				&uni_name, ei);
1287	else
1288		ret = exfat_move_file(new_parent_inode, &olddir, dentry,
1289				&newdir, &uni_name, ei);
1290
1291	if (!ret && new_inode) {
1292		/* delete entries of new_dir */
1293		ep = exfat_get_dentry(sb, p_dir, new_entry, &new_bh, NULL);
1294		if (!ep) {
1295			ret = -EIO;
1296			goto del_out;
1297		}
1298
1299		num_entries = exfat_count_ext_entries(sb, p_dir, new_entry, ep);
1300		if (num_entries < 0) {
1301			ret = -EIO;
1302			goto del_out;
1303		}
1304		brelse(new_bh);
1305
1306		if (exfat_remove_entries(new_inode, p_dir, new_entry, 0,
1307				num_entries + 1)) {
1308			ret = -EIO;
1309			goto del_out;
1310		}
1311
1312		/* Free the clusters if new_inode is a dir(as if exfat_rmdir) */
1313		if (new_entry_type == TYPE_DIR &&
1314		    new_ei->start_clu != EXFAT_EOF_CLUSTER) {
1315			/* new_ei, new_clu_to_free */
1316			struct exfat_chain new_clu_to_free;
1317
1318			exfat_chain_set(&new_clu_to_free, new_ei->start_clu,
1319				EXFAT_B_TO_CLU_ROUND_UP(i_size_read(new_inode),
1320				sbi), new_ei->flags);
1321
1322			if (exfat_free_cluster(new_inode, &new_clu_to_free)) {
1323				/* just set I/O error only */
1324				ret = -EIO;
1325			}
1326
1327			i_size_write(new_inode, 0);
1328			new_ei->start_clu = EXFAT_EOF_CLUSTER;
1329			new_ei->flags = ALLOC_NO_FAT_CHAIN;
1330		}
1331del_out:
1332		/* Update new_inode ei
1333		 * Prevent syncing removed new_inode
1334		 * (new_ei is already initialized above code ("if (new_inode)")
1335		 */
1336		new_ei->dir.dir = DIR_DELETED;
1337	}
1338	exfat_clear_volume_dirty(sb);
1339out:
1340	return ret;
1341}
1342
1343static int exfat_rename(struct inode *old_dir, struct dentry *old_dentry,
1344		struct inode *new_dir, struct dentry *new_dentry,
1345		unsigned int flags)
1346{
1347	struct inode *old_inode, *new_inode;
1348	struct super_block *sb = old_dir->i_sb;
1349	loff_t i_pos;
1350	int err;
1351
1352	/*
1353	 * The VFS already checks for existence, so for local filesystems
1354	 * the RENAME_NOREPLACE implementation is equivalent to plain rename.
1355	 * Don't support any other flags
1356	 */
1357	if (flags & ~RENAME_NOREPLACE)
1358		return -EINVAL;
1359
1360	mutex_lock(&EXFAT_SB(sb)->s_lock);
1361	old_inode = old_dentry->d_inode;
1362	new_inode = new_dentry->d_inode;
1363
1364	err = __exfat_rename(old_dir, EXFAT_I(old_inode), new_dir, new_dentry);
1365	if (err)
1366		goto unlock;
1367
1368	inode_inc_iversion(new_dir);
1369	new_dir->i_ctime = new_dir->i_mtime = new_dir->i_atime =
1370		EXFAT_I(new_dir)->i_crtime = current_time(new_dir);
1371	exfat_truncate_atime(&new_dir->i_atime);
1372	if (IS_DIRSYNC(new_dir))
1373		exfat_sync_inode(new_dir);
1374	else
1375		mark_inode_dirty(new_dir);
1376
1377	i_pos = ((loff_t)EXFAT_I(old_inode)->dir.dir << 32) |
1378		(EXFAT_I(old_inode)->entry & 0xffffffff);
1379	exfat_unhash_inode(old_inode);
1380	exfat_hash_inode(old_inode, i_pos);
1381	if (IS_DIRSYNC(new_dir))
1382		exfat_sync_inode(old_inode);
1383	else
1384		mark_inode_dirty(old_inode);
1385
1386	if (S_ISDIR(old_inode->i_mode) && old_dir != new_dir) {
1387		drop_nlink(old_dir);
1388		if (!new_inode)
1389			inc_nlink(new_dir);
1390	}
1391
1392	inode_inc_iversion(old_dir);
1393	old_dir->i_ctime = old_dir->i_mtime = current_time(old_dir);
1394	if (IS_DIRSYNC(old_dir))
1395		exfat_sync_inode(old_dir);
1396	else
1397		mark_inode_dirty(old_dir);
1398
1399	if (new_inode) {
1400		exfat_unhash_inode(new_inode);
1401
1402		/* skip drop_nlink if new_inode already has been dropped */
1403		if (new_inode->i_nlink) {
1404			drop_nlink(new_inode);
1405			if (S_ISDIR(new_inode->i_mode))
1406				drop_nlink(new_inode);
1407		} else {
1408			exfat_warn(sb, "abnormal access to an inode dropped");
1409			WARN_ON(new_inode->i_nlink == 0);
1410		}
1411		new_inode->i_ctime = EXFAT_I(new_inode)->i_crtime =
1412			current_time(new_inode);
1413	}
1414
1415unlock:
1416	mutex_unlock(&EXFAT_SB(sb)->s_lock);
1417	return err;
1418}
1419
1420const struct inode_operations exfat_dir_inode_operations = {
1421	.create		= exfat_create,
1422	.lookup		= exfat_lookup,
1423	.unlink		= exfat_unlink,
1424	.mkdir		= exfat_mkdir,
1425	.rmdir		= exfat_rmdir,
1426	.rename		= exfat_rename,
1427	.setattr	= exfat_setattr,
1428	.getattr	= exfat_getattr,
1429};
1430