1/*
2 * fs/f2fs/dir.c
3 *
4 * Copyright (c) 2012 Samsung Electronics Co., Ltd.
5 *             http://www.samsung.com/
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 */
11#include <linux/fs.h>
12#include <linux/f2fs_fs.h>
13#include "f2fs.h"
14#include "node.h"
15#include "acl.h"
16#include "xattr.h"
17
18static unsigned long dir_blocks(struct inode *inode)
19{
20	return ((unsigned long long) (i_size_read(inode) + PAGE_CACHE_SIZE - 1))
21							>> PAGE_CACHE_SHIFT;
22}
23
24static unsigned int dir_buckets(unsigned int level, int dir_level)
25{
26	if (level + dir_level < MAX_DIR_HASH_DEPTH / 2)
27		return 1 << (level + dir_level);
28	else
29		return MAX_DIR_BUCKETS;
30}
31
32static unsigned int bucket_blocks(unsigned int level)
33{
34	if (level < MAX_DIR_HASH_DEPTH / 2)
35		return 2;
36	else
37		return 4;
38}
39
40unsigned char f2fs_filetype_table[F2FS_FT_MAX] = {
41	[F2FS_FT_UNKNOWN]	= DT_UNKNOWN,
42	[F2FS_FT_REG_FILE]	= DT_REG,
43	[F2FS_FT_DIR]		= DT_DIR,
44	[F2FS_FT_CHRDEV]	= DT_CHR,
45	[F2FS_FT_BLKDEV]	= DT_BLK,
46	[F2FS_FT_FIFO]		= DT_FIFO,
47	[F2FS_FT_SOCK]		= DT_SOCK,
48	[F2FS_FT_SYMLINK]	= DT_LNK,
49};
50
51#define S_SHIFT 12
52static unsigned char f2fs_type_by_mode[S_IFMT >> S_SHIFT] = {
53	[S_IFREG >> S_SHIFT]	= F2FS_FT_REG_FILE,
54	[S_IFDIR >> S_SHIFT]	= F2FS_FT_DIR,
55	[S_IFCHR >> S_SHIFT]	= F2FS_FT_CHRDEV,
56	[S_IFBLK >> S_SHIFT]	= F2FS_FT_BLKDEV,
57	[S_IFIFO >> S_SHIFT]	= F2FS_FT_FIFO,
58	[S_IFSOCK >> S_SHIFT]	= F2FS_FT_SOCK,
59	[S_IFLNK >> S_SHIFT]	= F2FS_FT_SYMLINK,
60};
61
62void set_de_type(struct f2fs_dir_entry *de, umode_t mode)
63{
64	de->file_type = f2fs_type_by_mode[(mode & S_IFMT) >> S_SHIFT];
65}
66
67static unsigned long dir_block_index(unsigned int level,
68				int dir_level, unsigned int idx)
69{
70	unsigned long i;
71	unsigned long bidx = 0;
72
73	for (i = 0; i < level; i++)
74		bidx += dir_buckets(i, dir_level) * bucket_blocks(i);
75	bidx += idx * bucket_blocks(level);
76	return bidx;
77}
78
79static bool early_match_name(size_t namelen, f2fs_hash_t namehash,
80				struct f2fs_dir_entry *de)
81{
82	if (le16_to_cpu(de->name_len) != namelen)
83		return false;
84
85	if (de->hash_code != namehash)
86		return false;
87
88	return true;
89}
90
91static struct f2fs_dir_entry *find_in_block(struct page *dentry_page,
92				struct qstr *name, int *max_slots,
93				struct page **res_page)
94{
95	struct f2fs_dentry_block *dentry_blk;
96	struct f2fs_dir_entry *de;
97	struct f2fs_dentry_ptr d;
98
99	dentry_blk = (struct f2fs_dentry_block *)kmap(dentry_page);
100
101	make_dentry_ptr(&d, (void *)dentry_blk, 1);
102	de = find_target_dentry(name, max_slots, &d);
103
104	if (de)
105		*res_page = dentry_page;
106	else
107		kunmap(dentry_page);
108
109	/*
110	 * For the most part, it should be a bug when name_len is zero.
111	 * We stop here for figuring out where the bugs has occurred.
112	 */
113	f2fs_bug_on(F2FS_P_SB(dentry_page), d.max < 0);
114	return de;
115}
116
117struct f2fs_dir_entry *find_target_dentry(struct qstr *name, int *max_slots,
118						struct f2fs_dentry_ptr *d)
119{
120	struct f2fs_dir_entry *de;
121	unsigned long bit_pos = 0;
122	f2fs_hash_t namehash = f2fs_dentry_hash(name);
123	int max_len = 0;
124
125	if (max_slots)
126		*max_slots = 0;
127	while (bit_pos < d->max) {
128		if (!test_bit_le(bit_pos, d->bitmap)) {
129			bit_pos++;
130			max_len++;
131			continue;
132		}
133
134		de = &d->dentry[bit_pos];
135		if (early_match_name(name->len, namehash, de) &&
136			!memcmp(d->filename[bit_pos], name->name, name->len))
137			goto found;
138
139		if (max_slots && max_len > *max_slots)
140			*max_slots = max_len;
141		max_len = 0;
142
143		/* remain bug on condition */
144		if (unlikely(!de->name_len))
145			d->max = -1;
146
147		bit_pos += GET_DENTRY_SLOTS(le16_to_cpu(de->name_len));
148	}
149
150	de = NULL;
151found:
152	if (max_slots && max_len > *max_slots)
153		*max_slots = max_len;
154	return de;
155}
156
157static struct f2fs_dir_entry *find_in_level(struct inode *dir,
158			unsigned int level, struct qstr *name,
159			f2fs_hash_t namehash, struct page **res_page)
160{
161	int s = GET_DENTRY_SLOTS(name->len);
162	unsigned int nbucket, nblock;
163	unsigned int bidx, end_block;
164	struct page *dentry_page;
165	struct f2fs_dir_entry *de = NULL;
166	bool room = false;
167	int max_slots;
168
169	f2fs_bug_on(F2FS_I_SB(dir), level > MAX_DIR_HASH_DEPTH);
170
171	nbucket = dir_buckets(level, F2FS_I(dir)->i_dir_level);
172	nblock = bucket_blocks(level);
173
174	bidx = dir_block_index(level, F2FS_I(dir)->i_dir_level,
175					le32_to_cpu(namehash) % nbucket);
176	end_block = bidx + nblock;
177
178	for (; bidx < end_block; bidx++) {
179		/* no need to allocate new dentry pages to all the indices */
180		dentry_page = find_data_page(dir, bidx, true);
181		if (IS_ERR(dentry_page)) {
182			room = true;
183			continue;
184		}
185
186		de = find_in_block(dentry_page, name, &max_slots, res_page);
187		if (de)
188			break;
189
190		if (max_slots >= s)
191			room = true;
192		f2fs_put_page(dentry_page, 0);
193	}
194
195	if (!de && room && F2FS_I(dir)->chash != namehash) {
196		F2FS_I(dir)->chash = namehash;
197		F2FS_I(dir)->clevel = level;
198	}
199
200	return de;
201}
202
203/*
204 * Find an entry in the specified directory with the wanted name.
205 * It returns the page where the entry was found (as a parameter - res_page),
206 * and the entry itself. Page is returned mapped and unlocked.
207 * Entry is guaranteed to be valid.
208 */
209struct f2fs_dir_entry *f2fs_find_entry(struct inode *dir,
210			struct qstr *child, struct page **res_page)
211{
212	unsigned long npages = dir_blocks(dir);
213	struct f2fs_dir_entry *de = NULL;
214	f2fs_hash_t name_hash;
215	unsigned int max_depth;
216	unsigned int level;
217
218	*res_page = NULL;
219
220	if (f2fs_has_inline_dentry(dir))
221		return find_in_inline_dir(dir, child, res_page);
222
223	if (npages == 0)
224		return NULL;
225
226	name_hash = f2fs_dentry_hash(child);
227	max_depth = F2FS_I(dir)->i_current_depth;
228
229	for (level = 0; level < max_depth; level++) {
230		de = find_in_level(dir, level, child, name_hash, res_page);
231		if (de)
232			break;
233	}
234	if (!de && F2FS_I(dir)->chash != name_hash) {
235		F2FS_I(dir)->chash = name_hash;
236		F2FS_I(dir)->clevel = level - 1;
237	}
238	return de;
239}
240
241struct f2fs_dir_entry *f2fs_parent_dir(struct inode *dir, struct page **p)
242{
243	struct page *page;
244	struct f2fs_dir_entry *de;
245	struct f2fs_dentry_block *dentry_blk;
246
247	if (f2fs_has_inline_dentry(dir))
248		return f2fs_parent_inline_dir(dir, p);
249
250	page = get_lock_data_page(dir, 0);
251	if (IS_ERR(page))
252		return NULL;
253
254	dentry_blk = kmap(page);
255	de = &dentry_blk->dentry[1];
256	*p = page;
257	unlock_page(page);
258	return de;
259}
260
261ino_t f2fs_inode_by_name(struct inode *dir, struct qstr *qstr)
262{
263	ino_t res = 0;
264	struct f2fs_dir_entry *de;
265	struct page *page;
266
267	de = f2fs_find_entry(dir, qstr, &page);
268	if (de) {
269		res = le32_to_cpu(de->ino);
270		f2fs_dentry_kunmap(dir, page);
271		f2fs_put_page(page, 0);
272	}
273
274	return res;
275}
276
277void f2fs_set_link(struct inode *dir, struct f2fs_dir_entry *de,
278		struct page *page, struct inode *inode)
279{
280	enum page_type type = f2fs_has_inline_dentry(dir) ? NODE : DATA;
281	lock_page(page);
282	f2fs_wait_on_page_writeback(page, type);
283	de->ino = cpu_to_le32(inode->i_ino);
284	set_de_type(de, inode->i_mode);
285	f2fs_dentry_kunmap(dir, page);
286	set_page_dirty(page);
287	dir->i_mtime = dir->i_ctime = CURRENT_TIME;
288	mark_inode_dirty(dir);
289
290	f2fs_put_page(page, 1);
291}
292
293static void init_dent_inode(const struct qstr *name, struct page *ipage)
294{
295	struct f2fs_inode *ri;
296
297	f2fs_wait_on_page_writeback(ipage, NODE);
298
299	/* copy name info. to this inode page */
300	ri = F2FS_INODE(ipage);
301	ri->i_namelen = cpu_to_le32(name->len);
302	memcpy(ri->i_name, name->name, name->len);
303	set_page_dirty(ipage);
304}
305
306int update_dent_inode(struct inode *inode, const struct qstr *name)
307{
308	struct page *page;
309
310	page = get_node_page(F2FS_I_SB(inode), inode->i_ino);
311	if (IS_ERR(page))
312		return PTR_ERR(page);
313
314	init_dent_inode(name, page);
315	f2fs_put_page(page, 1);
316
317	return 0;
318}
319
320void do_make_empty_dir(struct inode *inode, struct inode *parent,
321					struct f2fs_dentry_ptr *d)
322{
323	struct f2fs_dir_entry *de;
324
325	de = &d->dentry[0];
326	de->name_len = cpu_to_le16(1);
327	de->hash_code = 0;
328	de->ino = cpu_to_le32(inode->i_ino);
329	memcpy(d->filename[0], ".", 1);
330	set_de_type(de, inode->i_mode);
331
332	de = &d->dentry[1];
333	de->hash_code = 0;
334	de->name_len = cpu_to_le16(2);
335	de->ino = cpu_to_le32(parent->i_ino);
336	memcpy(d->filename[1], "..", 2);
337	set_de_type(de, parent->i_mode);
338
339	test_and_set_bit_le(0, (void *)d->bitmap);
340	test_and_set_bit_le(1, (void *)d->bitmap);
341}
342
343static int make_empty_dir(struct inode *inode,
344		struct inode *parent, struct page *page)
345{
346	struct page *dentry_page;
347	struct f2fs_dentry_block *dentry_blk;
348	struct f2fs_dentry_ptr d;
349
350	if (f2fs_has_inline_dentry(inode))
351		return make_empty_inline_dir(inode, parent, page);
352
353	dentry_page = get_new_data_page(inode, page, 0, true);
354	if (IS_ERR(dentry_page))
355		return PTR_ERR(dentry_page);
356
357	dentry_blk = kmap_atomic(dentry_page);
358
359	make_dentry_ptr(&d, (void *)dentry_blk, 1);
360	do_make_empty_dir(inode, parent, &d);
361
362	kunmap_atomic(dentry_blk);
363
364	set_page_dirty(dentry_page);
365	f2fs_put_page(dentry_page, 1);
366	return 0;
367}
368
369struct page *init_inode_metadata(struct inode *inode, struct inode *dir,
370			const struct qstr *name, struct page *dpage)
371{
372	struct page *page;
373	int err;
374
375	if (is_inode_flag_set(F2FS_I(inode), FI_NEW_INODE)) {
376		page = new_inode_page(inode);
377		if (IS_ERR(page))
378			return page;
379
380		if (S_ISDIR(inode->i_mode)) {
381			err = make_empty_dir(inode, dir, page);
382			if (err)
383				goto error;
384		}
385
386		err = f2fs_init_acl(inode, dir, page, dpage);
387		if (err)
388			goto put_error;
389
390		err = f2fs_init_security(inode, dir, name, page);
391		if (err)
392			goto put_error;
393	} else {
394		page = get_node_page(F2FS_I_SB(dir), inode->i_ino);
395		if (IS_ERR(page))
396			return page;
397
398		set_cold_node(inode, page);
399	}
400
401	if (name)
402		init_dent_inode(name, page);
403
404	/*
405	 * This file should be checkpointed during fsync.
406	 * We lost i_pino from now on.
407	 */
408	if (is_inode_flag_set(F2FS_I(inode), FI_INC_LINK)) {
409		file_lost_pino(inode);
410		/*
411		 * If link the tmpfile to alias through linkat path,
412		 * we should remove this inode from orphan list.
413		 */
414		if (inode->i_nlink == 0)
415			remove_orphan_inode(F2FS_I_SB(dir), inode->i_ino);
416		inc_nlink(inode);
417	}
418	return page;
419
420put_error:
421	f2fs_put_page(page, 1);
422error:
423	/* once the failed inode becomes a bad inode, i_mode is S_IFREG */
424	truncate_inode_pages(&inode->i_data, 0);
425	truncate_blocks(inode, 0, false);
426	remove_dirty_dir_inode(inode);
427	remove_inode_page(inode);
428	return ERR_PTR(err);
429}
430
431void update_parent_metadata(struct inode *dir, struct inode *inode,
432						unsigned int current_depth)
433{
434	if (inode && is_inode_flag_set(F2FS_I(inode), FI_NEW_INODE)) {
435		if (S_ISDIR(inode->i_mode)) {
436			inc_nlink(dir);
437			set_inode_flag(F2FS_I(dir), FI_UPDATE_DIR);
438		}
439		clear_inode_flag(F2FS_I(inode), FI_NEW_INODE);
440	}
441	dir->i_mtime = dir->i_ctime = CURRENT_TIME;
442	mark_inode_dirty(dir);
443
444	if (F2FS_I(dir)->i_current_depth != current_depth) {
445		F2FS_I(dir)->i_current_depth = current_depth;
446		set_inode_flag(F2FS_I(dir), FI_UPDATE_DIR);
447	}
448
449	if (inode && is_inode_flag_set(F2FS_I(inode), FI_INC_LINK))
450		clear_inode_flag(F2FS_I(inode), FI_INC_LINK);
451}
452
453int room_for_filename(const void *bitmap, int slots, int max_slots)
454{
455	int bit_start = 0;
456	int zero_start, zero_end;
457next:
458	zero_start = find_next_zero_bit_le(bitmap, max_slots, bit_start);
459	if (zero_start >= max_slots)
460		return max_slots;
461
462	zero_end = find_next_bit_le(bitmap, max_slots, zero_start);
463	if (zero_end - zero_start >= slots)
464		return zero_start;
465
466	bit_start = zero_end + 1;
467
468	if (zero_end + 1 >= max_slots)
469		return max_slots;
470	goto next;
471}
472
473void f2fs_update_dentry(nid_t ino, umode_t mode, struct f2fs_dentry_ptr *d,
474				const struct qstr *name, f2fs_hash_t name_hash,
475				unsigned int bit_pos)
476{
477	struct f2fs_dir_entry *de;
478	int slots = GET_DENTRY_SLOTS(name->len);
479	int i;
480
481	de = &d->dentry[bit_pos];
482	de->hash_code = name_hash;
483	de->name_len = cpu_to_le16(name->len);
484	memcpy(d->filename[bit_pos], name->name, name->len);
485	de->ino = cpu_to_le32(ino);
486	set_de_type(de, mode);
487	for (i = 0; i < slots; i++)
488		test_and_set_bit_le(bit_pos + i, (void *)d->bitmap);
489}
490
491/*
492 * Caller should grab and release a rwsem by calling f2fs_lock_op() and
493 * f2fs_unlock_op().
494 */
495int __f2fs_add_link(struct inode *dir, const struct qstr *name,
496				struct inode *inode, nid_t ino, umode_t mode)
497{
498	unsigned int bit_pos;
499	unsigned int level;
500	unsigned int current_depth;
501	unsigned long bidx, block;
502	f2fs_hash_t dentry_hash;
503	unsigned int nbucket, nblock;
504	size_t namelen = name->len;
505	struct page *dentry_page = NULL;
506	struct f2fs_dentry_block *dentry_blk = NULL;
507	struct f2fs_dentry_ptr d;
508	int slots = GET_DENTRY_SLOTS(namelen);
509	struct page *page = NULL;
510	int err = 0;
511
512	if (f2fs_has_inline_dentry(dir)) {
513		err = f2fs_add_inline_entry(dir, name, inode, ino, mode);
514		if (!err || err != -EAGAIN)
515			return err;
516		else
517			err = 0;
518	}
519
520	dentry_hash = f2fs_dentry_hash(name);
521	level = 0;
522	current_depth = F2FS_I(dir)->i_current_depth;
523	if (F2FS_I(dir)->chash == dentry_hash) {
524		level = F2FS_I(dir)->clevel;
525		F2FS_I(dir)->chash = 0;
526	}
527
528start:
529	if (unlikely(current_depth == MAX_DIR_HASH_DEPTH))
530		return -ENOSPC;
531
532	/* Increase the depth, if required */
533	if (level == current_depth)
534		++current_depth;
535
536	nbucket = dir_buckets(level, F2FS_I(dir)->i_dir_level);
537	nblock = bucket_blocks(level);
538
539	bidx = dir_block_index(level, F2FS_I(dir)->i_dir_level,
540				(le32_to_cpu(dentry_hash) % nbucket));
541
542	for (block = bidx; block <= (bidx + nblock - 1); block++) {
543		dentry_page = get_new_data_page(dir, NULL, block, true);
544		if (IS_ERR(dentry_page))
545			return PTR_ERR(dentry_page);
546
547		dentry_blk = kmap(dentry_page);
548		bit_pos = room_for_filename(&dentry_blk->dentry_bitmap,
549						slots, NR_DENTRY_IN_BLOCK);
550		if (bit_pos < NR_DENTRY_IN_BLOCK)
551			goto add_dentry;
552
553		kunmap(dentry_page);
554		f2fs_put_page(dentry_page, 1);
555	}
556
557	/* Move to next level to find the empty slot for new dentry */
558	++level;
559	goto start;
560add_dentry:
561	f2fs_wait_on_page_writeback(dentry_page, DATA);
562
563	if (inode) {
564		down_write(&F2FS_I(inode)->i_sem);
565		page = init_inode_metadata(inode, dir, name, NULL);
566		if (IS_ERR(page)) {
567			err = PTR_ERR(page);
568			goto fail;
569		}
570	}
571
572	make_dentry_ptr(&d, (void *)dentry_blk, 1);
573	f2fs_update_dentry(ino, mode, &d, name, dentry_hash, bit_pos);
574
575	set_page_dirty(dentry_page);
576
577	if (inode) {
578		/* we don't need to mark_inode_dirty now */
579		F2FS_I(inode)->i_pino = dir->i_ino;
580		update_inode(inode, page);
581		f2fs_put_page(page, 1);
582	}
583
584	update_parent_metadata(dir, inode, current_depth);
585fail:
586	if (inode)
587		up_write(&F2FS_I(inode)->i_sem);
588
589	if (is_inode_flag_set(F2FS_I(dir), FI_UPDATE_DIR)) {
590		update_inode_page(dir);
591		clear_inode_flag(F2FS_I(dir), FI_UPDATE_DIR);
592	}
593	kunmap(dentry_page);
594	f2fs_put_page(dentry_page, 1);
595	return err;
596}
597
598int f2fs_do_tmpfile(struct inode *inode, struct inode *dir)
599{
600	struct page *page;
601	int err = 0;
602
603	down_write(&F2FS_I(inode)->i_sem);
604	page = init_inode_metadata(inode, dir, NULL, NULL);
605	if (IS_ERR(page)) {
606		err = PTR_ERR(page);
607		goto fail;
608	}
609	/* we don't need to mark_inode_dirty now */
610	update_inode(inode, page);
611	f2fs_put_page(page, 1);
612
613	clear_inode_flag(F2FS_I(inode), FI_NEW_INODE);
614fail:
615	up_write(&F2FS_I(inode)->i_sem);
616	return err;
617}
618
619void f2fs_drop_nlink(struct inode *dir, struct inode *inode, struct page *page)
620{
621	struct f2fs_sb_info *sbi = F2FS_I_SB(dir);
622
623	down_write(&F2FS_I(inode)->i_sem);
624
625	if (S_ISDIR(inode->i_mode)) {
626		drop_nlink(dir);
627		if (page)
628			update_inode(dir, page);
629		else
630			update_inode_page(dir);
631	}
632	inode->i_ctime = CURRENT_TIME;
633
634	drop_nlink(inode);
635	if (S_ISDIR(inode->i_mode)) {
636		drop_nlink(inode);
637		i_size_write(inode, 0);
638	}
639	up_write(&F2FS_I(inode)->i_sem);
640	update_inode_page(inode);
641
642	if (inode->i_nlink == 0)
643		add_orphan_inode(sbi, inode->i_ino);
644	else
645		release_orphan_inode(sbi);
646}
647
648/*
649 * It only removes the dentry from the dentry page, corresponding name
650 * entry in name page does not need to be touched during deletion.
651 */
652void f2fs_delete_entry(struct f2fs_dir_entry *dentry, struct page *page,
653					struct inode *dir, struct inode *inode)
654{
655	struct	f2fs_dentry_block *dentry_blk;
656	unsigned int bit_pos;
657	int slots = GET_DENTRY_SLOTS(le16_to_cpu(dentry->name_len));
658	int i;
659
660	if (f2fs_has_inline_dentry(dir))
661		return f2fs_delete_inline_entry(dentry, page, dir, inode);
662
663	lock_page(page);
664	f2fs_wait_on_page_writeback(page, DATA);
665
666	dentry_blk = page_address(page);
667	bit_pos = dentry - dentry_blk->dentry;
668	for (i = 0; i < slots; i++)
669		clear_bit_le(bit_pos + i, &dentry_blk->dentry_bitmap);
670
671	/* Let's check and deallocate this dentry page */
672	bit_pos = find_next_bit_le(&dentry_blk->dentry_bitmap,
673			NR_DENTRY_IN_BLOCK,
674			0);
675	kunmap(page); /* kunmap - pair of f2fs_find_entry */
676	set_page_dirty(page);
677
678	dir->i_ctime = dir->i_mtime = CURRENT_TIME;
679
680	if (inode)
681		f2fs_drop_nlink(dir, inode, NULL);
682
683	if (bit_pos == NR_DENTRY_IN_BLOCK) {
684		truncate_hole(dir, page->index, page->index + 1);
685		clear_page_dirty_for_io(page);
686		ClearPagePrivate(page);
687		ClearPageUptodate(page);
688		inode_dec_dirty_pages(dir);
689	}
690	f2fs_put_page(page, 1);
691}
692
693bool f2fs_empty_dir(struct inode *dir)
694{
695	unsigned long bidx;
696	struct page *dentry_page;
697	unsigned int bit_pos;
698	struct f2fs_dentry_block *dentry_blk;
699	unsigned long nblock = dir_blocks(dir);
700
701	if (f2fs_has_inline_dentry(dir))
702		return f2fs_empty_inline_dir(dir);
703
704	for (bidx = 0; bidx < nblock; bidx++) {
705		dentry_page = get_lock_data_page(dir, bidx);
706		if (IS_ERR(dentry_page)) {
707			if (PTR_ERR(dentry_page) == -ENOENT)
708				continue;
709			else
710				return false;
711		}
712
713		dentry_blk = kmap_atomic(dentry_page);
714		if (bidx == 0)
715			bit_pos = 2;
716		else
717			bit_pos = 0;
718		bit_pos = find_next_bit_le(&dentry_blk->dentry_bitmap,
719						NR_DENTRY_IN_BLOCK,
720						bit_pos);
721		kunmap_atomic(dentry_blk);
722
723		f2fs_put_page(dentry_page, 1);
724
725		if (bit_pos < NR_DENTRY_IN_BLOCK)
726			return false;
727	}
728	return true;
729}
730
731bool f2fs_fill_dentries(struct dir_context *ctx, struct f2fs_dentry_ptr *d,
732						unsigned int start_pos)
733{
734	unsigned char d_type = DT_UNKNOWN;
735	unsigned int bit_pos;
736	struct f2fs_dir_entry *de = NULL;
737
738	bit_pos = ((unsigned long)ctx->pos % d->max);
739
740	while (bit_pos < d->max) {
741		bit_pos = find_next_bit_le(d->bitmap, d->max, bit_pos);
742		if (bit_pos >= d->max)
743			break;
744
745		de = &d->dentry[bit_pos];
746		if (de->file_type < F2FS_FT_MAX)
747			d_type = f2fs_filetype_table[de->file_type];
748		else
749			d_type = DT_UNKNOWN;
750		if (!dir_emit(ctx, d->filename[bit_pos],
751					le16_to_cpu(de->name_len),
752					le32_to_cpu(de->ino), d_type))
753			return true;
754
755		bit_pos += GET_DENTRY_SLOTS(le16_to_cpu(de->name_len));
756		ctx->pos = start_pos + bit_pos;
757	}
758	return false;
759}
760
761static int f2fs_readdir(struct file *file, struct dir_context *ctx)
762{
763	struct inode *inode = file_inode(file);
764	unsigned long npages = dir_blocks(inode);
765	struct f2fs_dentry_block *dentry_blk = NULL;
766	struct page *dentry_page = NULL;
767	struct file_ra_state *ra = &file->f_ra;
768	unsigned int n = ((unsigned long)ctx->pos / NR_DENTRY_IN_BLOCK);
769	struct f2fs_dentry_ptr d;
770
771	if (f2fs_has_inline_dentry(inode))
772		return f2fs_read_inline_dir(file, ctx);
773
774	/* readahead for multi pages of dir */
775	if (npages - n > 1 && !ra_has_index(ra, n))
776		page_cache_sync_readahead(inode->i_mapping, ra, file, n,
777				min(npages - n, (pgoff_t)MAX_DIR_RA_PAGES));
778
779	for (; n < npages; n++) {
780		dentry_page = get_lock_data_page(inode, n);
781		if (IS_ERR(dentry_page))
782			continue;
783
784		dentry_blk = kmap(dentry_page);
785
786		make_dentry_ptr(&d, (void *)dentry_blk, 1);
787
788		if (f2fs_fill_dentries(ctx, &d, n * NR_DENTRY_IN_BLOCK))
789			goto stop;
790
791		ctx->pos = (n + 1) * NR_DENTRY_IN_BLOCK;
792		kunmap(dentry_page);
793		f2fs_put_page(dentry_page, 1);
794		dentry_page = NULL;
795	}
796stop:
797	if (dentry_page && !IS_ERR(dentry_page)) {
798		kunmap(dentry_page);
799		f2fs_put_page(dentry_page, 1);
800	}
801
802	return 0;
803}
804
805const struct file_operations f2fs_dir_operations = {
806	.llseek		= generic_file_llseek,
807	.read		= generic_read_dir,
808	.iterate	= f2fs_readdir,
809	.fsync		= f2fs_sync_file,
810	.unlocked_ioctl	= f2fs_ioctl,
811};
812