summaryrefslogtreecommitdiffstats
path: root/fs/f2fs/dir.c
blob: 94756f55a97e7d86052cdb49ce79fcc131738cfd (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
/*
 * fs/f2fs/dir.c
 *
 * Copyright (c) 2012 Samsung Electronics Co., Ltd.
 *             http://www.samsung.com/
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */
#include <linux/fs.h>
#include <linux/f2fs_fs.h>
#include "f2fs.h"
#include "node.h"
#include "acl.h"
#include "xattr.h"

static unsigned long dir_blocks(struct inode *inode)
{
	return ((unsigned long long) (i_size_read(inode) + PAGE_SIZE - 1))
							>> PAGE_SHIFT;
}

static unsigned int dir_buckets(unsigned int level, int dir_level)
{
	if (level + dir_level < MAX_DIR_HASH_DEPTH / 2)
		return 1 << (level + dir_level);
	else
		return MAX_DIR_BUCKETS;
}

static unsigned int bucket_blocks(unsigned int level)
{
	if (level < MAX_DIR_HASH_DEPTH / 2)
		return 2;
	else
		return 4;
}

static unsigned char f2fs_filetype_table[F2FS_FT_MAX] = {
	[F2FS_FT_UNKNOWN]	= DT_UNKNOWN,
	[F2FS_FT_REG_FILE]	= DT_REG,
	[F2FS_FT_DIR]		= DT_DIR,
	[F2FS_FT_CHRDEV]	= DT_CHR,
	[F2FS_FT_BLKDEV]	= DT_BLK,
	[F2FS_FT_FIFO]		= DT_FIFO,
	[F2FS_FT_SOCK]		= DT_SOCK,
	[F2FS_FT_SYMLINK]	= DT_LNK,
};

static unsigned char f2fs_type_by_mode[S_IFMT >> S_SHIFT] = {
	[S_IFREG >> S_SHIFT]	= F2FS_FT_REG_FILE,
	[S_IFDIR >> S_SHIFT]	= F2FS_FT_DIR,
	[S_IFCHR >> S_SHIFT]	= F2FS_FT_CHRDEV,
	[S_IFBLK >> S_SHIFT]	= F2FS_FT_BLKDEV,
	[S_IFIFO >> S_SHIFT]	= F2FS_FT_FIFO,
	[S_IFSOCK >> S_SHIFT]	= F2FS_FT_SOCK,
	[S_IFLNK >> S_SHIFT]	= F2FS_FT_SYMLINK,
};

void set_de_type(struct f2fs_dir_entry *de, umode_t mode)
{
	de->file_type = f2fs_type_by_mode[(mode & S_IFMT) >> S_SHIFT];
}

unsigned char get_de_type(struct f2fs_dir_entry *de)
{
	if (de->file_type < F2FS_FT_MAX)
		return f2fs_filetype_table[de->file_type];
	return DT_UNKNOWN;
}

static unsigned long dir_block_index(unsigned int level,
				int dir_level, unsigned int idx)
{
	unsigned long i;
	unsigned long bidx = 0;

	for (i = 0; i < level; i++)
		bidx += dir_buckets(i, dir_level) * bucket_blocks(i);
	bidx += idx * bucket_blocks(level);
	return bidx;
}

static struct f2fs_dir_entry *find_in_block(struct page *dentry_page,
				struct fscrypt_name *fname,
				f2fs_hash_t namehash,
				int *max_slots,
				struct page **res_page)
{
	struct f2fs_dentry_block *dentry_blk;
	struct f2fs_dir_entry *de;
	struct f2fs_dentry_ptr d;

	dentry_blk = (struct f2fs_dentry_block *)kmap(dentry_page);

	make_dentry_ptr_block(NULL, &d, dentry_blk);
	de = find_target_dentry(fname, namehash, max_slots, &d);
	if (de)
		*res_page = dentry_page;
	else
		kunmap(dentry_page);

	return de;
}

struct f2fs_dir_entry *find_target_dentry(struct fscrypt_name *fname,
			f2fs_hash_t namehash, int *max_slots,
			struct f2fs_dentry_ptr *d)
{
	struct f2fs_dir_entry *de;
	unsigned long bit_pos = 0;
	int max_len = 0;

	if (max_slots)
		*max_slots = 0;
	while (bit_pos < d->max) {
		if (!test_bit_le(bit_pos, d->bitmap)) {
			bit_pos++;
			max_len++;
			continue;
		}

		de = &d->dentry[bit_pos];

		if (unlikely(!de->name_len)) {
			bit_pos++;
			continue;
		}

		if (de->hash_code == namehash &&
		    fscrypt_match_name(fname, d->filename[bit_pos],
				       le16_to_cpu(de->name_len)))
			goto found;

		if (max_slots && max_len > *max_slots)
			*max_slots = max_len;
		max_len = 0;

		bit_pos += GET_DENTRY_SLOTS(le16_to_cpu(de->name_len));
	}

	de = NULL;
found:
	if (max_slots && max_len > *max_slots)
		*max_slots = max_len;
	return de;
}

static struct f2fs_dir_entry *find_in_level(struct inode *dir,
					unsigned int level,
					struct fscrypt_name *fname,
					struct page **res_page)
{
	struct qstr name = FSTR_TO_QSTR(&fname->disk_name);
	int s = GET_DENTRY_SLOTS(name.len);
	unsigned int nbucket, nblock;
	unsigned int bidx, end_block;
	struct page *dentry_page;
	struct f2fs_dir_entry *de = NULL;
	bool room = false;
	int max_slots;
	f2fs_hash_t namehash = f2fs_dentry_hash(&name, fname);

	nbucket = dir_buckets(level, F2FS_I(dir)->i_dir_level);
	nblock = bucket_blocks(level);

	bidx = dir_block_index(level, F2FS_I(dir)->i_dir_level,
					le32_to_cpu(namehash) % nbucket);
	end_block = bidx + nblock;

	for (; bidx < end_block; bidx++) {
		/* no need to allocate new dentry pages to all the indices */
		dentry_page = find_data_page(dir, bidx);
		if (IS_ERR(dentry_page)) {
			if (PTR_ERR(dentry_page) == -ENOENT) {
				room = true;
				continue;
			} else {
				*res_page = dentry_page;
				break;
			}
		}

		de = find_in_block(dentry_page, fname, namehash, &max_slots,
								res_page);
		if (de)
			break;

		if (max_slots >= s)
			room = true;
		f2fs_put_page(dentry_page, 0);
	}

	if (!de && room && F2FS_I(dir)->chash != namehash) {
		F2FS_I(dir)->chash = namehash;
		F2FS_I(dir)->clevel = level;
	}

	return de;
}

struct f2fs_dir_entry *__f2fs_find_entry(struct inode *dir,
			struct fscrypt_name *fname, struct page **res_page)
{
	unsigned long npages = dir_blocks(dir);
	struct f2fs_dir_entry *de = NULL;
	unsigned int max_depth;
	unsigned int level;

	if (f2fs_has_inline_dentry(dir)) {
		*res_page = NULL;
		de = find_in_inline_dir(dir, fname, res_page);
		goto out;
	}

	if (npages == 0) {
		*res_page = NULL;
		goto out;
	}

	max_depth = F2FS_I(dir)->i_current_depth;
	if (unlikely(max_depth > MAX_DIR_HASH_DEPTH)) {
		f2fs_msg(F2FS_I_SB(dir)->sb, KERN_WARNING,
				"Corrupted max_depth of %lu: %u",
				dir->i_ino, max_depth);
		max_depth = MAX_DIR_HASH_DEPTH;
		f2fs_i_depth_write(dir, max_depth);
	}

	for (level = 0; level < max_depth; level++) {
		*res_page = NULL;
		de = find_in_level(dir, level, fname, res_page);
		if (de || IS_ERR(*res_page))
			break;
	}
out:
	/* This is to increase the speed of f2fs_create */
	if (!de)
		F2FS_I(dir)->task = current;
	return de;
}

/*
 * Find an entry in the specified directory with the wanted name.
 * It returns the page where the entry was found (as a parameter - res_page),
 * and the entry itself. Page is returned mapped and unlocked.
 * Entry is guaranteed to be valid.
 */
struct f2fs_dir_entry *f2fs_find_entry(struct inode *dir,
			const struct qstr *child, struct page **res_page)
{
	struct f2fs_dir_entry *de = NULL;
	struct fscrypt_name fname;
	int err;

	err = fscrypt_setup_filename(dir, child, 1, &fname);
	if (err) {
		if (err == -ENOENT)
			*res_page = NULL;
		else
			*res_page = ERR_PTR(err);
		return NULL;
	}

	de = __f2fs_find_entry(dir, &fname, res_page);

	fscrypt_free_filename(&fname);
	return de;
}

struct f2fs_dir_entry *f2fs_parent_dir(struct inode *dir, struct page **p)
{
	struct qstr dotdot = QSTR_INIT("..", 2);

	return f2fs_find_entry(dir, &dotdot, p);
}

ino_t f2fs_inode_by_name(struct inode *dir, const struct qstr *qstr,
							struct page **page)
{
	ino_t res = 0;
	struct f2fs_dir_entry *de;

	de = f2fs_find_entry(dir, qstr, page);
	if (de) {
		res = le32_to_cpu(de->ino);
		f2fs_dentry_kunmap(dir, *page);
		f2fs_put_page(*page, 0);
	}

	return res;
}

void f2fs_set_link(struct inode *dir, struct f2fs_dir_entry *de,
		struct page *page, struct inode *inode)
{
	enum page_type type = f2fs_has_inline_dentry(dir) ? NODE : DATA;
	lock_page(page);
	f2fs_wait_on_page_writeback(page, type, true);
	de->ino = cpu_to_le32(inode->i_ino);
	set_de_type(de, inode->i_mode);
	f2fs_dentry_kunmap(dir, page);
	set_page_dirty(page);

	dir->i_mtime = dir->i_ctime = current_time(dir);
	f2fs_mark_inode_dirty_sync(dir, false);
	f2fs_put_page(page, 1);
}

static void init_dent_inode(const struct qstr *name, struct page *ipage)
{
	struct f2fs_inode *ri;

	f2fs_wait_on_page_writeback(ipage, NODE, true);

	/* copy name info. to this inode page */
	ri = F2FS_INODE(ipage);
	ri->i_namelen = cpu_to_le32(name->len);
	memcpy(ri->i_name, name->name, name->len);
	set_page_dirty(ipage);
}

void do_make_empty_dir(struct inode *inode, struct inode *parent,
					struct f2fs_dentry_ptr *d)
{
	struct qstr dot = QSTR_INIT(".", 1);
	struct qstr dotdot = QSTR_INIT("..", 2);

	/* update dirent of "." */
	f2fs_update_dentry(inode->i_ino, inode->i_mode, d, &dot, 0, 0);

	/* update dirent of ".." */
	f2fs_update_dentry(parent->i_ino, parent->i_mode, d, &dotdot, 0, 1);
}

static int make_empty_dir(struct inode *inode,
		struct inode *parent, struct page *page)
{
	struct page *dentry_page;
	struct f2fs_dentry_block *dentry_blk;
	struct f2fs_dentry_ptr d;

	if (f2fs_has_inline_dentry(inode))
		return make_empty_inline_dir(inode, parent, page);

	dentry_page = get_new_data_page(inode, page, 0, true);
	if (IS_ERR(dentry_page))
		return PTR_ERR(dentry_page);

	dentry_blk = kmap_atomic(dentry_page);

	make_dentry_ptr_block(NULL, &d, dentry_blk);
	do_make_empty_dir(inode, parent, &d);

	kunmap_atomic(dentry_blk);

	set_page_dirty(dentry_page);
	f2fs_put_page(dentry_page, 1);
	return 0;
}

struct page *init_inode_metadata(struct inode *inode, struct inode *dir,
			const struct qstr *new_name, const struct qstr *orig_name,
			struct page *dpage)
{
	struct page *page;
	int err;

	if (is_inode_flag_set(inode, FI_NEW_INODE)) {
		page = new_inode_page(inode);
		if (IS_ERR(page))
			return page;

		if (S_ISDIR(inode->i_mode)) {
			/* in order to handle error case */
			get_page(page);
			err = make_empty_dir(inode, dir, page);
			if (err) {
				lock_page(page);
				goto put_error;
			}
			put_page(page);
		}

		err = f2fs_init_acl(inode, dir, page, dpage);
		if (err)
			goto put_error;

		err = f2fs_init_security(inode, dir, orig_name, page);
		if (err)
			goto put_error;

		if (f2fs_encrypted_inode(dir) && f2fs_may_encrypt(inode)) {
			err = fscrypt_inherit_context(dir, inode, page, false);
			if (err)
				goto put_error;
		}
	} else {
		page = get_node_page(F2FS_I_SB(dir), inode->i_ino);
		if (IS_ERR(page))
			return page;

		set_cold_node(inode, page);
	}

	if (new_name) {
		init_dent_inode(new_name, page);
		if (f2fs_encrypted_inode(dir))
			file_set_enc_name(inode);
	}

	/*
	 * This file should be checkpointed during fsync.
	 * We lost i_pino from now on.
	 */
	if (is_inode_flag_set(inode, FI_INC_LINK)) {
		file_lost_pino(inode);
		/*
		 * If link the tmpfile to alias through linkat path,
		 * we should remove this inode from orphan list.
		 */
		if (inode->i_nlink == 0)
			remove_orphan_inode(F2FS_I_SB(dir), inode->i_ino);
		f2fs_i_links_write(inode, true);
	}
	return page;

put_error:
	clear_nlink(inode);
	update_inode(inode, page);
	f2fs_put_page(page, 1);
	return ERR_PTR(err);
}

void update_parent_metadata(struct inode *dir, struct inode *inode,
						unsigned int current_depth)
{
	if (inode && is_inode_flag_set(inode, FI_NEW_INODE)) {
		if (S_ISDIR(inode->i_mode))
			f2fs_i_links_write(dir, true);
		clear_inode_flag(inode, FI_NEW_INODE);
	}
	dir->i_mtime = dir->i_ctime = current_time(dir);
	f2fs_mark_inode_dirty_sync(dir, false);

	if (F2FS_I(dir)->i_current_depth != current_depth)
		f2fs_i_depth_write(dir, current_depth);

	if (inode && is_inode_flag_set(inode, FI_INC_LINK))
		clear_inode_flag(inode, FI_INC_LINK);
}

int room_for_filename(const void *bitmap, int slots, int max_slots)
{
	int bit_start = 0;
	int zero_start, zero_end;
next:
	zero_start = find_next_zero_bit_le(bitmap, max_slots, bit_start);
	if (zero_start >= max_slots)
		return max_slots;

	zero_end = find_next_bit_le(bitmap, max_slots, zero_start);
	if (zero_end - zero_start >= slots)
		return zero_start;

	bit_start = zero_end + 1;

	if (zero_end + 1 >= max_slots)
		return max_slots;
	goto next;
}

void f2fs_update_dentry(nid_t ino, umode_t mode, struct f2fs_dentry_ptr *d,
				const struct qstr *name, f2fs_hash_t name_hash,
				unsigned int bit_pos)
{
	struct f2fs_dir_entry *de;
	int slots = GET_DENTRY_SLOTS(name->len);
	int i;

	de = &d->dentry[bit_pos];
	de->hash_code = name_hash;
	de->name_len = cpu_to_le16(name->len);
	memcpy(d->filename[bit_pos], name->name, name->len);
	de->ino = cpu_to_le32(ino);
	set_de_type(de, mode);
	for (i = 0; i < slots; i++) {
		__set_bit_le(bit_pos + i, (void *)d->bitmap);
		/* avoid wrong garbage data for readdir */
		if (i)
			(de + i)->name_len = 0;
	}
}

int f2fs_add_regular_entry(struct inode *dir, const struct qstr *new_name,
				const struct qstr *orig_name,
				struct inode *inode, nid_t ino, umode_t mode)
{
	unsigned int bit_pos;
	unsigned int level;
	unsigned int current_depth;
	unsigned long bidx, block;
	f2fs_hash_t dentry_hash;
	unsigned int nbucket, nblock;
	struct page *dentry_page = NULL;
	struct f2fs_dentry_block *dentry_blk = NULL;
	struct f2fs_dentry_ptr d;
	struct page *page = NULL;
	int slots, err = 0;

	level = 0;
	slots = GET_DENTRY_SLOTS(new_name->len);
	dentry_hash = f2fs_dentry_hash(new_name, NULL);

	current_depth = F2FS_I(dir)->i_current_depth;
	if (F2FS_I(dir)->chash == dentry_hash) {
		level = F2FS_I(dir)->clevel;
		F2FS_I(dir)->chash = 0;
	}

start:
#ifdef CONFIG_F2FS_FAULT_INJECTION
	if (time_to_inject(F2FS_I_SB(dir), FAULT_DIR_DEPTH)) {
		f2fs_show_injection_info(FAULT_DIR_DEPTH);
		return -ENOSPC;
	}
#endif
	if (unlikely(current_depth == MAX_DIR_HASH_DEPTH))
		return -ENOSPC;

	/* Increase the depth, if required */
	if (level == current_depth)
		++current_depth;

	nbucket = dir_buckets(level, F2FS_I(dir)->i_dir_level);
	nblock = bucket_blocks(level);

	bidx = dir_block_index(level, F2FS_I(dir)->i_dir_level,
				(le32_to_cpu(dentry_hash) % nbucket));

	for (block = bidx; block <= (bidx + nblock - 1); block++) {
		dentry_page = get_new_data_page(dir, NULL, block, true);
		if (IS_ERR(dentry_page))
			return PTR_ERR(dentry_page);

		dentry_blk = kmap(dentry_page);
		bit_pos = room_for_filename(&dentry_blk->dentry_bitmap,
						slots, NR_DENTRY_IN_BLOCK);
		if (bit_pos < NR_DENTRY_IN_BLOCK)
			goto add_dentry;

		kunmap(dentry_page);
		f2fs_put_page(dentry_page, 1);
	}

	/* Move to next level to find the empty slot for new dentry */
	++level;
	goto start;
add_dentry:
	f2fs_wait_on_page_writeback(dentry_page, DATA, true);

	if (inode) {
		down_write(&F2FS_I(inode)->i_sem);
		page = init_inode_metadata(inode, dir, new_name,
						orig_name, NULL);
		if (IS_ERR(page)) {
			err = PTR_ERR(page);
			goto fail;
		}
	}

	make_dentry_ptr_block(NULL, &d, dentry_blk);
	f2fs_update_dentry(ino, mode, &d, new_name, dentry_hash, bit_pos);

	set_page_dirty(dentry_page);

	if (inode) {
		f2fs_i_pino_write(inode, dir->i_ino);
		f2fs_put_page(page, 1);
	}

	update_parent_metadata(dir, inode, current_depth);
fail:
	if (inode)
		up_write(&F2FS_I(inode)->i_sem);

	kunmap(dentry_page);
	f2fs_put_page(dentry_page, 1);

	return err;
}

int __f2fs_do_add_link(struct inode *dir, struct fscrypt_name *fname,
				struct inode *inode, nid_t ino, umode_t mode)
{
	struct qstr new_name;
	int err = -EAGAIN;

	new_name.name = fname_name(fname);
	new_name.len = fname_len(fname);

	if (f2fs_has_inline_dentry(dir))
		err = f2fs_add_inline_entry(dir, &new_name, fname->usr_fname,
							inode, ino, mode);
	if (err == -EAGAIN)
		err = f2fs_add_regular_entry(dir, &new_name, fname->usr_fname,
							inode, ino, mode);

	f2fs_update_time(F2FS_I_SB(dir), REQ_TIME);
	return err;
}

/*
 * Caller should grab and release a rwsem by calling f2fs_lock_op() and
 * f2fs_unlock_op().
 */
int __f2fs_add_link(struct inode *dir, const struct qstr *name,
				struct inode *inode, nid_t ino, umode_t mode)
{
	struct fscrypt_name fname;
	struct page *page = NULL;
	struct f2fs_dir_entry *de = NULL;
	int err;

	err = fscrypt_setup_filename(dir, name, 0, &fname);
	if (err)
		return err;

	/*
	 * An immature stakable filesystem shows a race condition between lookup
	 * and create. If we have same task when doing lookup and create, it's
	 * definitely fine as expected by VFS normally. Otherwise, let's just
	 * verify on-disk dentry one more time, which guarantees filesystem
	 * consistency more.
	 */
	if (current != F2FS_I(dir)->task) {
		de = __f2fs_find_entry(dir, &fname, &page);
		F2FS_I(dir)->task = NULL;
	}
	if (de) {
		f2fs_dentry_kunmap(dir, page);
		f2fs_put_page(page, 0);
		err = -EEXIST;
	} else if (IS_ERR(page)) {
		err = PTR_ERR(page);
	} else {
		err = __f2fs_do_add_link(dir, &fname, inode, ino, mode);
	}
	fscrypt_free_filename(&fname);
	return err;
}

int f2fs_do_tmpfile(struct inode *inode, struct inode *dir)
{
	struct page *page;
	int err = 0;

	down_write(&F2FS_I(inode)->i_sem);
	page = init_inode_metadata(inode, dir, NULL, NULL, NULL);
	if (IS_ERR(page)) {
		err = PTR_ERR(page);
		goto fail;
	}
	f2fs_put_page(page, 1);

	clear_inode_flag(inode, FI_NEW_INODE);
fail:
	up_write(&F2FS_I(inode)->i_sem);
	f2fs_update_time(F2FS_I_SB(inode), REQ_TIME);
	return err;
}

void f2fs_drop_nlink(struct inode *dir, struct inode *inode)
{
	struct f2fs_sb_info *sbi = F2FS_I_SB(dir);

	down_write(&F2FS_I(inode)->i_sem);

	if (S_ISDIR(inode->i_mode))
		f2fs_i_links_write(dir, false);
	inode->i_ctime = current_time(inode);

	f2fs_i_links_write(inode, false);
	if (S_ISDIR(inode->i_mode)) {
		f2fs_i_links_write(inode, false);
		f2fs_i_size_write(inode, 0);
	}
	up_write(&F2FS_I(inode)->i_sem);

	if (inode->i_nlink == 0)
		add_orphan_inode(inode);
	else
		release_orphan_inode(sbi);
}

/*
 * It only removes the dentry from the dentry page, corresponding name
 * entry in name page does not need to be touched during deletion.
 */
void f2fs_delete_entry(struct f2fs_dir_entry *dentry, struct page *page,
					struct inode *dir, struct inode *inode)
{
	struct	f2fs_dentry_block *dentry_blk;
	unsigned int bit_pos;
	int slots = GET_DENTRY_SLOTS(le16_to_cpu(dentry->name_len));
	int i;

	f2fs_update_time(F2FS_I_SB(dir), REQ_TIME);

	if (f2fs_has_inline_dentry(dir))
		return f2fs_delete_inline_entry(dentry, page, dir, inode);

	lock_page(page);
	f2fs_wait_on_page_writeback(page, DATA, true);

	dentry_blk = page_address(page);
	bit_pos = dentry - dentry_blk->dentry;
	for (i = 0; i < slots; i++)
		__clear_bit_le(bit_pos + i, &dentry_blk->dentry_bitmap);

	/* Let's check and deallocate this dentry page */
	bit_pos = find_next_bit_le(&dentry_blk->dentry_bitmap,
			NR_DENTRY_IN_BLOCK,
			0);
	kunmap(page); /* kunmap - pair of f2fs_find_entry */
	set_page_dirty(page);

	dir->i_ctime = dir->i_mtime = current_time(dir);
	f2fs_mark_inode_dirty_sync(dir, false);

	if (inode)
		f2fs_drop_nlink(dir, inode);

	if (bit_pos == NR_DENTRY_IN_BLOCK &&
			!truncate_hole(dir, page->index, page->index + 1)) {
		clear_page_dirty_for_io(page);
		ClearPagePrivate(page);
		ClearPageUptodate(page);
		inode_dec_dirty_pages(dir);
		remove_dirty_inode(dir);
	}
	f2fs_put_page(page, 1);
}

bool f2fs_empty_dir(struct inode *dir)
{
	unsigned long bidx;
	struct page *dentry_page;
	unsigned int bit_pos;
	struct f2fs_dentry_block *dentry_blk;
	unsigned long nblock = dir_blocks(dir);

	if (f2fs_has_inline_dentry(dir))
		return f2fs_empty_inline_dir(dir);

	for (bidx = 0; bidx < nblock; bidx++) {
		dentry_page = get_lock_data_page(dir, bidx, false);
		if (IS_ERR(dentry_page)) {
			if (PTR_ERR(dentry_page) == -ENOENT)
				continue;
			else
				return false;
		}

		dentry_blk = kmap_atomic(dentry_page);
		if (bidx == 0)
			bit_pos = 2;
		else
			bit_pos = 0;
		bit_pos = find_next_bit_le(&dentry_blk->dentry_bitmap,
						NR_DENTRY_IN_BLOCK,
						bit_pos);
		kunmap_atomic(dentry_blk);

		f2fs_put_page(dentry_page, 1);

		if (bit_pos < NR_DENTRY_IN_BLOCK)
			return false;
	}
	return true;
}

int f2fs_fill_dentries(struct dir_context *ctx, struct f2fs_dentry_ptr *d,
			unsigned int start_pos, struct fscrypt_str *fstr)
{
	unsigned char d_type = DT_UNKNOWN;
	unsigned int bit_pos;
	struct f2fs_dir_entry *de = NULL;
	struct fscrypt_str de_name = FSTR_INIT(NULL, 0);

	bit_pos = ((unsigned long)ctx->pos % d->max);

	while (bit_pos < d->max) {
		bit_pos = find_next_bit_le(d->bitmap, d->max, bit_pos);
		if (bit_pos >= d->max)
			break;

		de = &d->dentry[bit_pos];
		if (de->name_len == 0) {
			bit_pos++;
			ctx->pos = start_pos + bit_pos;
			continue;
		}

		d_type = get_de_type(de);

		de_name.name = d->filename[bit_pos];
		de_name.len = le16_to_cpu(de->name_len);

		if (f2fs_encrypted_inode(d->inode)) {
			int save_len = fstr->len;
			int err;

			err = fscrypt_fname_disk_to_usr(d->inode,
						(u32)de->hash_code, 0,
						&de_name, fstr);
			if (err)
				return err;

			de_name = *fstr;
			fstr->len = save_len;
		}

		if (!dir_emit(ctx, de_name.name, de_name.len,
					le32_to_cpu(de->ino), d_type))
			return 1;

		bit_pos += GET_DENTRY_SLOTS(le16_to_cpu(de->name_len));
		ctx->pos = start_pos + bit_pos;
	}
	return 0;
}

static int f2fs_readdir(struct file *file, struct dir_context *ctx)
{
	struct inode *inode = file_inode(file);
	unsigned long npages = dir_blocks(inode);
	struct f2fs_dentry_block *dentry_blk = NULL;
	struct page *dentry_page = NULL;
	struct file_ra_state *ra = &file->f_ra;
	unsigned int n = ((unsigned long)ctx->pos / NR_DENTRY_IN_BLOCK);
	struct f2fs_dentry_ptr d;
	struct fscrypt_str fstr = FSTR_INIT(NULL, 0);
	int err = 0;

	if (f2fs_encrypted_inode(inode)) {
		err = fscrypt_get_encryption_info(inode);
		if (err && err != -ENOKEY)
			return err;

		err = fscrypt_fname_alloc_buffer(inode, F2FS_NAME_LEN, &fstr);
		if (err < 0)
			return err;
	}

	if (f2fs_has_inline_dentry(inode)) {
		err = f2fs_read_inline_dir(file, ctx, &fstr);
		goto out;
	}

	/* readahead for multi pages of dir */
	if (npages - n > 1 && !ra_has_index(ra, n))
		page_cache_sync_readahead(inode->i_mapping, ra, file, n,
				min(npages - n, (pgoff_t)MAX_DIR_RA_PAGES));

	for (; n < npages; n++) {
		dentry_page = get_lock_data_page(inode, n, false);
		if (IS_ERR(dentry_page)) {
			err = PTR_ERR(dentry_page);
			if (err == -ENOENT) {
				err = 0;
				continue;
			} else {
				goto out;
			}
		}

		dentry_blk = kmap(dentry_page);

		make_dentry_ptr_block(inode, &d, dentry_blk);

		err = f2fs_fill_dentries(ctx, &d,
				n * NR_DENTRY_IN_BLOCK, &fstr);
		if (err) {
			kunmap(dentry_page);
			f2fs_put_page(dentry_page, 1);
			break;
		}

		ctx->pos = (n + 1) * NR_DENTRY_IN_BLOCK;
		kunmap(dentry_page);
		f2fs_put_page(dentry_page, 1);
	}
out:
	fscrypt_fname_free_buffer(&fstr);
	return err < 0 ? err : 0;
}

static int f2fs_dir_open(struct inode *inode, struct file *filp)
{
	if (f2fs_encrypted_inode(inode))
		return fscrypt_get_encryption_info(inode) ? -EACCES : 0;
	return 0;
}

const struct file_operations f2fs_dir_operations = {
	.llseek		= generic_file_llseek,
	.read		= generic_read_dir,
	.iterate_shared	= f2fs_readdir,
	.fsync		= f2fs_sync_file,
	.open		= f2fs_dir_open,
	.unlocked_ioctl	= f2fs_ioctl,
#ifdef CONFIG_COMPAT
	.compat_ioctl   = f2fs_compat_ioctl,
#endif
};