xref: /openbmc/linux/fs/f2fs/dir.c (revision 9d749629)
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 
17 static unsigned long dir_blocks(struct inode *inode)
18 {
19 	return ((unsigned long long) (i_size_read(inode) + PAGE_CACHE_SIZE - 1))
20 							>> PAGE_CACHE_SHIFT;
21 }
22 
23 static unsigned int dir_buckets(unsigned int level)
24 {
25 	if (level < MAX_DIR_HASH_DEPTH / 2)
26 		return 1 << level;
27 	else
28 		return 1 << ((MAX_DIR_HASH_DEPTH / 2) - 1);
29 }
30 
31 static unsigned int bucket_blocks(unsigned int level)
32 {
33 	if (level < MAX_DIR_HASH_DEPTH / 2)
34 		return 2;
35 	else
36 		return 4;
37 }
38 
39 static unsigned char f2fs_filetype_table[F2FS_FT_MAX] = {
40 	[F2FS_FT_UNKNOWN]	= DT_UNKNOWN,
41 	[F2FS_FT_REG_FILE]	= DT_REG,
42 	[F2FS_FT_DIR]		= DT_DIR,
43 	[F2FS_FT_CHRDEV]	= DT_CHR,
44 	[F2FS_FT_BLKDEV]	= DT_BLK,
45 	[F2FS_FT_FIFO]		= DT_FIFO,
46 	[F2FS_FT_SOCK]		= DT_SOCK,
47 	[F2FS_FT_SYMLINK]	= DT_LNK,
48 };
49 
50 #define S_SHIFT 12
51 static unsigned char f2fs_type_by_mode[S_IFMT >> S_SHIFT] = {
52 	[S_IFREG >> S_SHIFT]	= F2FS_FT_REG_FILE,
53 	[S_IFDIR >> S_SHIFT]	= F2FS_FT_DIR,
54 	[S_IFCHR >> S_SHIFT]	= F2FS_FT_CHRDEV,
55 	[S_IFBLK >> S_SHIFT]	= F2FS_FT_BLKDEV,
56 	[S_IFIFO >> S_SHIFT]	= F2FS_FT_FIFO,
57 	[S_IFSOCK >> S_SHIFT]	= F2FS_FT_SOCK,
58 	[S_IFLNK >> S_SHIFT]	= F2FS_FT_SYMLINK,
59 };
60 
61 static void set_de_type(struct f2fs_dir_entry *de, struct inode *inode)
62 {
63 	mode_t mode = inode->i_mode;
64 	de->file_type = f2fs_type_by_mode[(mode & S_IFMT) >> S_SHIFT];
65 }
66 
67 static unsigned long dir_block_index(unsigned int level, unsigned int idx)
68 {
69 	unsigned long i;
70 	unsigned long bidx = 0;
71 
72 	for (i = 0; i < level; i++)
73 		bidx += dir_buckets(i) * bucket_blocks(i);
74 	bidx += idx * bucket_blocks(level);
75 	return bidx;
76 }
77 
78 static bool early_match_name(const char *name, size_t namelen,
79 			f2fs_hash_t namehash, struct f2fs_dir_entry *de)
80 {
81 	if (le16_to_cpu(de->name_len) != namelen)
82 		return false;
83 
84 	if (de->hash_code != namehash)
85 		return false;
86 
87 	return true;
88 }
89 
90 static struct f2fs_dir_entry *find_in_block(struct page *dentry_page,
91 			const char *name, size_t namelen, int *max_slots,
92 			f2fs_hash_t namehash, struct page **res_page)
93 {
94 	struct f2fs_dir_entry *de;
95 	unsigned long bit_pos, end_pos, next_pos;
96 	struct f2fs_dentry_block *dentry_blk = kmap(dentry_page);
97 	int slots;
98 
99 	bit_pos = find_next_bit_le(&dentry_blk->dentry_bitmap,
100 					NR_DENTRY_IN_BLOCK, 0);
101 	while (bit_pos < NR_DENTRY_IN_BLOCK) {
102 		de = &dentry_blk->dentry[bit_pos];
103 		slots = GET_DENTRY_SLOTS(le16_to_cpu(de->name_len));
104 
105 		if (early_match_name(name, namelen, namehash, de)) {
106 			if (!memcmp(dentry_blk->filename[bit_pos],
107 							name, namelen)) {
108 				*res_page = dentry_page;
109 				goto found;
110 			}
111 		}
112 		next_pos = bit_pos + slots;
113 		bit_pos = find_next_bit_le(&dentry_blk->dentry_bitmap,
114 				NR_DENTRY_IN_BLOCK, next_pos);
115 		if (bit_pos >= NR_DENTRY_IN_BLOCK)
116 			end_pos = NR_DENTRY_IN_BLOCK;
117 		else
118 			end_pos = bit_pos;
119 		if (*max_slots < end_pos - next_pos)
120 			*max_slots = end_pos - next_pos;
121 	}
122 
123 	de = NULL;
124 	kunmap(dentry_page);
125 found:
126 	return de;
127 }
128 
129 static struct f2fs_dir_entry *find_in_level(struct inode *dir,
130 		unsigned int level, const char *name, size_t namelen,
131 			f2fs_hash_t namehash, struct page **res_page)
132 {
133 	int s = GET_DENTRY_SLOTS(namelen);
134 	unsigned int nbucket, nblock;
135 	unsigned int bidx, end_block;
136 	struct page *dentry_page;
137 	struct f2fs_dir_entry *de = NULL;
138 	bool room = false;
139 	int max_slots = 0;
140 
141 	BUG_ON(level > MAX_DIR_HASH_DEPTH);
142 
143 	nbucket = dir_buckets(level);
144 	nblock = bucket_blocks(level);
145 
146 	bidx = dir_block_index(level, le32_to_cpu(namehash) % nbucket);
147 	end_block = bidx + nblock;
148 
149 	for (; bidx < end_block; bidx++) {
150 		/* no need to allocate new dentry pages to all the indices */
151 		dentry_page = find_data_page(dir, bidx);
152 		if (IS_ERR(dentry_page)) {
153 			room = true;
154 			continue;
155 		}
156 
157 		de = find_in_block(dentry_page, name, namelen,
158 					&max_slots, namehash, res_page);
159 		if (de)
160 			break;
161 
162 		if (max_slots >= s)
163 			room = true;
164 		f2fs_put_page(dentry_page, 0);
165 	}
166 
167 	if (!de && room && F2FS_I(dir)->chash != namehash) {
168 		F2FS_I(dir)->chash = namehash;
169 		F2FS_I(dir)->clevel = level;
170 	}
171 
172 	return de;
173 }
174 
175 /*
176  * Find an entry in the specified directory with the wanted name.
177  * It returns the page where the entry was found (as a parameter - res_page),
178  * and the entry itself. Page is returned mapped and unlocked.
179  * Entry is guaranteed to be valid.
180  */
181 struct f2fs_dir_entry *f2fs_find_entry(struct inode *dir,
182 			struct qstr *child, struct page **res_page)
183 {
184 	const char *name = child->name;
185 	size_t namelen = child->len;
186 	unsigned long npages = dir_blocks(dir);
187 	struct f2fs_dir_entry *de = NULL;
188 	f2fs_hash_t name_hash;
189 	unsigned int max_depth;
190 	unsigned int level;
191 
192 	if (npages == 0)
193 		return NULL;
194 
195 	*res_page = NULL;
196 
197 	name_hash = f2fs_dentry_hash(name, namelen);
198 	max_depth = F2FS_I(dir)->i_current_depth;
199 
200 	for (level = 0; level < max_depth; level++) {
201 		de = find_in_level(dir, level, name,
202 				namelen, name_hash, res_page);
203 		if (de)
204 			break;
205 	}
206 	if (!de && F2FS_I(dir)->chash != name_hash) {
207 		F2FS_I(dir)->chash = name_hash;
208 		F2FS_I(dir)->clevel = level - 1;
209 	}
210 	return de;
211 }
212 
213 struct f2fs_dir_entry *f2fs_parent_dir(struct inode *dir, struct page **p)
214 {
215 	struct page *page = NULL;
216 	struct f2fs_dir_entry *de = NULL;
217 	struct f2fs_dentry_block *dentry_blk = NULL;
218 
219 	page = get_lock_data_page(dir, 0);
220 	if (IS_ERR(page))
221 		return NULL;
222 
223 	dentry_blk = kmap(page);
224 	de = &dentry_blk->dentry[1];
225 	*p = page;
226 	unlock_page(page);
227 	return de;
228 }
229 
230 ino_t f2fs_inode_by_name(struct inode *dir, struct qstr *qstr)
231 {
232 	ino_t res = 0;
233 	struct f2fs_dir_entry *de;
234 	struct page *page;
235 
236 	de = f2fs_find_entry(dir, qstr, &page);
237 	if (de) {
238 		res = le32_to_cpu(de->ino);
239 		kunmap(page);
240 		f2fs_put_page(page, 0);
241 	}
242 
243 	return res;
244 }
245 
246 void f2fs_set_link(struct inode *dir, struct f2fs_dir_entry *de,
247 		struct page *page, struct inode *inode)
248 {
249 	struct f2fs_sb_info *sbi = F2FS_SB(dir->i_sb);
250 
251 	mutex_lock_op(sbi, DENTRY_OPS);
252 	lock_page(page);
253 	wait_on_page_writeback(page);
254 	de->ino = cpu_to_le32(inode->i_ino);
255 	set_de_type(de, inode);
256 	kunmap(page);
257 	set_page_dirty(page);
258 	dir->i_mtime = dir->i_ctime = CURRENT_TIME;
259 	mark_inode_dirty(dir);
260 
261 	/* update parent inode number before releasing dentry page */
262 	F2FS_I(inode)->i_pino = dir->i_ino;
263 
264 	f2fs_put_page(page, 1);
265 	mutex_unlock_op(sbi, DENTRY_OPS);
266 }
267 
268 void init_dent_inode(struct dentry *dentry, struct page *ipage)
269 {
270 	struct f2fs_node *rn;
271 
272 	if (IS_ERR(ipage))
273 		return;
274 
275 	wait_on_page_writeback(ipage);
276 
277 	/* copy dentry info. to this inode page */
278 	rn = (struct f2fs_node *)page_address(ipage);
279 	rn->i.i_namelen = cpu_to_le32(dentry->d_name.len);
280 	memcpy(rn->i.i_name, dentry->d_name.name, dentry->d_name.len);
281 	set_page_dirty(ipage);
282 }
283 
284 static int init_inode_metadata(struct inode *inode, struct dentry *dentry)
285 {
286 	struct inode *dir = dentry->d_parent->d_inode;
287 
288 	if (is_inode_flag_set(F2FS_I(inode), FI_NEW_INODE)) {
289 		int err;
290 		err = new_inode_page(inode, dentry);
291 		if (err)
292 			return err;
293 
294 		if (S_ISDIR(inode->i_mode)) {
295 			err = f2fs_make_empty(inode, dir);
296 			if (err) {
297 				remove_inode_page(inode);
298 				return err;
299 			}
300 		}
301 
302 		err = f2fs_init_acl(inode, dir);
303 		if (err) {
304 			remove_inode_page(inode);
305 			return err;
306 		}
307 	} else {
308 		struct page *ipage;
309 		ipage = get_node_page(F2FS_SB(dir->i_sb), inode->i_ino);
310 		if (IS_ERR(ipage))
311 			return PTR_ERR(ipage);
312 		set_cold_node(inode, ipage);
313 		init_dent_inode(dentry, ipage);
314 		f2fs_put_page(ipage, 1);
315 	}
316 	if (is_inode_flag_set(F2FS_I(inode), FI_INC_LINK)) {
317 		inc_nlink(inode);
318 		f2fs_write_inode(inode, NULL);
319 	}
320 	return 0;
321 }
322 
323 static void update_parent_metadata(struct inode *dir, struct inode *inode,
324 						unsigned int current_depth)
325 {
326 	bool need_dir_update = false;
327 
328 	if (is_inode_flag_set(F2FS_I(inode), FI_NEW_INODE)) {
329 		if (S_ISDIR(inode->i_mode)) {
330 			inc_nlink(dir);
331 			need_dir_update = true;
332 		}
333 		clear_inode_flag(F2FS_I(inode), FI_NEW_INODE);
334 	}
335 	dir->i_mtime = dir->i_ctime = CURRENT_TIME;
336 	if (F2FS_I(dir)->i_current_depth != current_depth) {
337 		F2FS_I(dir)->i_current_depth = current_depth;
338 		need_dir_update = true;
339 	}
340 
341 	if (need_dir_update)
342 		f2fs_write_inode(dir, NULL);
343 	else
344 		mark_inode_dirty(dir);
345 
346 	if (is_inode_flag_set(F2FS_I(inode), FI_INC_LINK))
347 		clear_inode_flag(F2FS_I(inode), FI_INC_LINK);
348 }
349 
350 static int room_for_filename(struct f2fs_dentry_block *dentry_blk, int slots)
351 {
352 	int bit_start = 0;
353 	int zero_start, zero_end;
354 next:
355 	zero_start = find_next_zero_bit_le(&dentry_blk->dentry_bitmap,
356 						NR_DENTRY_IN_BLOCK,
357 						bit_start);
358 	if (zero_start >= NR_DENTRY_IN_BLOCK)
359 		return NR_DENTRY_IN_BLOCK;
360 
361 	zero_end = find_next_bit_le(&dentry_blk->dentry_bitmap,
362 						NR_DENTRY_IN_BLOCK,
363 						zero_start);
364 	if (zero_end - zero_start >= slots)
365 		return zero_start;
366 
367 	bit_start = zero_end + 1;
368 
369 	if (zero_end + 1 >= NR_DENTRY_IN_BLOCK)
370 		return NR_DENTRY_IN_BLOCK;
371 	goto next;
372 }
373 
374 int f2fs_add_link(struct dentry *dentry, struct inode *inode)
375 {
376 	unsigned int bit_pos;
377 	unsigned int level;
378 	unsigned int current_depth;
379 	unsigned long bidx, block;
380 	f2fs_hash_t dentry_hash;
381 	struct f2fs_dir_entry *de;
382 	unsigned int nbucket, nblock;
383 	struct inode *dir = dentry->d_parent->d_inode;
384 	struct f2fs_sb_info *sbi = F2FS_SB(dir->i_sb);
385 	const char *name = dentry->d_name.name;
386 	size_t namelen = dentry->d_name.len;
387 	struct page *dentry_page = NULL;
388 	struct f2fs_dentry_block *dentry_blk = NULL;
389 	int slots = GET_DENTRY_SLOTS(namelen);
390 	int err = 0;
391 	int i;
392 
393 	dentry_hash = f2fs_dentry_hash(name, dentry->d_name.len);
394 	level = 0;
395 	current_depth = F2FS_I(dir)->i_current_depth;
396 	if (F2FS_I(dir)->chash == dentry_hash) {
397 		level = F2FS_I(dir)->clevel;
398 		F2FS_I(dir)->chash = 0;
399 	}
400 
401 start:
402 	if (current_depth == MAX_DIR_HASH_DEPTH)
403 		return -ENOSPC;
404 
405 	/* Increase the depth, if required */
406 	if (level == current_depth)
407 		++current_depth;
408 
409 	nbucket = dir_buckets(level);
410 	nblock = bucket_blocks(level);
411 
412 	bidx = dir_block_index(level, (le32_to_cpu(dentry_hash) % nbucket));
413 
414 	for (block = bidx; block <= (bidx + nblock - 1); block++) {
415 		mutex_lock_op(sbi, DENTRY_OPS);
416 		dentry_page = get_new_data_page(dir, block, true);
417 		if (IS_ERR(dentry_page)) {
418 			mutex_unlock_op(sbi, DENTRY_OPS);
419 			return PTR_ERR(dentry_page);
420 		}
421 
422 		dentry_blk = kmap(dentry_page);
423 		bit_pos = room_for_filename(dentry_blk, slots);
424 		if (bit_pos < NR_DENTRY_IN_BLOCK)
425 			goto add_dentry;
426 
427 		kunmap(dentry_page);
428 		f2fs_put_page(dentry_page, 1);
429 		mutex_unlock_op(sbi, DENTRY_OPS);
430 	}
431 
432 	/* Move to next level to find the empty slot for new dentry */
433 	++level;
434 	goto start;
435 add_dentry:
436 	err = init_inode_metadata(inode, dentry);
437 	if (err)
438 		goto fail;
439 
440 	wait_on_page_writeback(dentry_page);
441 
442 	de = &dentry_blk->dentry[bit_pos];
443 	de->hash_code = dentry_hash;
444 	de->name_len = cpu_to_le16(namelen);
445 	memcpy(dentry_blk->filename[bit_pos], name, namelen);
446 	de->ino = cpu_to_le32(inode->i_ino);
447 	set_de_type(de, inode);
448 	for (i = 0; i < slots; i++)
449 		test_and_set_bit_le(bit_pos + i, &dentry_blk->dentry_bitmap);
450 	set_page_dirty(dentry_page);
451 
452 	update_parent_metadata(dir, inode, current_depth);
453 
454 	/* update parent inode number before releasing dentry page */
455 	F2FS_I(inode)->i_pino = dir->i_ino;
456 fail:
457 	kunmap(dentry_page);
458 	f2fs_put_page(dentry_page, 1);
459 	mutex_unlock_op(sbi, DENTRY_OPS);
460 	return err;
461 }
462 
463 /*
464  * It only removes the dentry from the dentry page,corresponding name
465  * entry in name page does not need to be touched during deletion.
466  */
467 void f2fs_delete_entry(struct f2fs_dir_entry *dentry, struct page *page,
468 						struct inode *inode)
469 {
470 	struct	f2fs_dentry_block *dentry_blk;
471 	unsigned int bit_pos;
472 	struct address_space *mapping = page->mapping;
473 	struct inode *dir = mapping->host;
474 	struct f2fs_sb_info *sbi = F2FS_SB(dir->i_sb);
475 	int slots = GET_DENTRY_SLOTS(le16_to_cpu(dentry->name_len));
476 	void *kaddr = page_address(page);
477 	int i;
478 
479 	mutex_lock_op(sbi, DENTRY_OPS);
480 
481 	lock_page(page);
482 	wait_on_page_writeback(page);
483 
484 	dentry_blk = (struct f2fs_dentry_block *)kaddr;
485 	bit_pos = dentry - (struct f2fs_dir_entry *)dentry_blk->dentry;
486 	for (i = 0; i < slots; i++)
487 		test_and_clear_bit_le(bit_pos + i, &dentry_blk->dentry_bitmap);
488 
489 	/* Let's check and deallocate this dentry page */
490 	bit_pos = find_next_bit_le(&dentry_blk->dentry_bitmap,
491 			NR_DENTRY_IN_BLOCK,
492 			0);
493 	kunmap(page); /* kunmap - pair of f2fs_find_entry */
494 	set_page_dirty(page);
495 
496 	dir->i_ctime = dir->i_mtime = CURRENT_TIME;
497 
498 	if (inode && S_ISDIR(inode->i_mode)) {
499 		drop_nlink(dir);
500 		f2fs_write_inode(dir, NULL);
501 	} else {
502 		mark_inode_dirty(dir);
503 	}
504 
505 	if (inode) {
506 		inode->i_ctime = CURRENT_TIME;
507 		drop_nlink(inode);
508 		if (S_ISDIR(inode->i_mode)) {
509 			drop_nlink(inode);
510 			i_size_write(inode, 0);
511 		}
512 		f2fs_write_inode(inode, NULL);
513 		if (inode->i_nlink == 0)
514 			add_orphan_inode(sbi, inode->i_ino);
515 	}
516 
517 	if (bit_pos == NR_DENTRY_IN_BLOCK) {
518 		truncate_hole(dir, page->index, page->index + 1);
519 		clear_page_dirty_for_io(page);
520 		ClearPageUptodate(page);
521 		dec_page_count(sbi, F2FS_DIRTY_DENTS);
522 		inode_dec_dirty_dents(dir);
523 	}
524 	f2fs_put_page(page, 1);
525 
526 	mutex_unlock_op(sbi, DENTRY_OPS);
527 }
528 
529 int f2fs_make_empty(struct inode *inode, struct inode *parent)
530 {
531 	struct page *dentry_page;
532 	struct f2fs_dentry_block *dentry_blk;
533 	struct f2fs_dir_entry *de;
534 	void *kaddr;
535 
536 	dentry_page = get_new_data_page(inode, 0, true);
537 	if (IS_ERR(dentry_page))
538 		return PTR_ERR(dentry_page);
539 
540 	kaddr = kmap_atomic(dentry_page);
541 	dentry_blk = (struct f2fs_dentry_block *)kaddr;
542 
543 	de = &dentry_blk->dentry[0];
544 	de->name_len = cpu_to_le16(1);
545 	de->hash_code = f2fs_dentry_hash(".", 1);
546 	de->ino = cpu_to_le32(inode->i_ino);
547 	memcpy(dentry_blk->filename[0], ".", 1);
548 	set_de_type(de, inode);
549 
550 	de = &dentry_blk->dentry[1];
551 	de->hash_code = f2fs_dentry_hash("..", 2);
552 	de->name_len = cpu_to_le16(2);
553 	de->ino = cpu_to_le32(parent->i_ino);
554 	memcpy(dentry_blk->filename[1], "..", 2);
555 	set_de_type(de, inode);
556 
557 	test_and_set_bit_le(0, &dentry_blk->dentry_bitmap);
558 	test_and_set_bit_le(1, &dentry_blk->dentry_bitmap);
559 	kunmap_atomic(kaddr);
560 
561 	set_page_dirty(dentry_page);
562 	f2fs_put_page(dentry_page, 1);
563 	return 0;
564 }
565 
566 bool f2fs_empty_dir(struct inode *dir)
567 {
568 	unsigned long bidx;
569 	struct page *dentry_page;
570 	unsigned int bit_pos;
571 	struct	f2fs_dentry_block *dentry_blk;
572 	unsigned long nblock = dir_blocks(dir);
573 
574 	for (bidx = 0; bidx < nblock; bidx++) {
575 		void *kaddr;
576 		dentry_page = get_lock_data_page(dir, bidx);
577 		if (IS_ERR(dentry_page)) {
578 			if (PTR_ERR(dentry_page) == -ENOENT)
579 				continue;
580 			else
581 				return false;
582 		}
583 
584 		kaddr = kmap_atomic(dentry_page);
585 		dentry_blk = (struct f2fs_dentry_block *)kaddr;
586 		if (bidx == 0)
587 			bit_pos = 2;
588 		else
589 			bit_pos = 0;
590 		bit_pos = find_next_bit_le(&dentry_blk->dentry_bitmap,
591 						NR_DENTRY_IN_BLOCK,
592 						bit_pos);
593 		kunmap_atomic(kaddr);
594 
595 		f2fs_put_page(dentry_page, 1);
596 
597 		if (bit_pos < NR_DENTRY_IN_BLOCK)
598 			return false;
599 	}
600 	return true;
601 }
602 
603 static int f2fs_readdir(struct file *file, void *dirent, filldir_t filldir)
604 {
605 	unsigned long pos = file->f_pos;
606 	struct inode *inode = file->f_dentry->d_inode;
607 	unsigned long npages = dir_blocks(inode);
608 	unsigned char *types = NULL;
609 	unsigned int bit_pos = 0, start_bit_pos = 0;
610 	int over = 0;
611 	struct f2fs_dentry_block *dentry_blk = NULL;
612 	struct f2fs_dir_entry *de = NULL;
613 	struct page *dentry_page = NULL;
614 	unsigned int n = 0;
615 	unsigned char d_type = DT_UNKNOWN;
616 	int slots;
617 
618 	types = f2fs_filetype_table;
619 	bit_pos = (pos % NR_DENTRY_IN_BLOCK);
620 	n = (pos / NR_DENTRY_IN_BLOCK);
621 
622 	for ( ; n < npages; n++) {
623 		dentry_page = get_lock_data_page(inode, n);
624 		if (IS_ERR(dentry_page))
625 			continue;
626 
627 		start_bit_pos = bit_pos;
628 		dentry_blk = kmap(dentry_page);
629 		while (bit_pos < NR_DENTRY_IN_BLOCK) {
630 			d_type = DT_UNKNOWN;
631 			bit_pos = find_next_bit_le(&dentry_blk->dentry_bitmap,
632 							NR_DENTRY_IN_BLOCK,
633 							bit_pos);
634 			if (bit_pos >= NR_DENTRY_IN_BLOCK)
635 				break;
636 
637 			de = &dentry_blk->dentry[bit_pos];
638 			if (types && de->file_type < F2FS_FT_MAX)
639 				d_type = types[de->file_type];
640 
641 			over = filldir(dirent,
642 					dentry_blk->filename[bit_pos],
643 					le16_to_cpu(de->name_len),
644 					(n * NR_DENTRY_IN_BLOCK) + bit_pos,
645 					le32_to_cpu(de->ino), d_type);
646 			if (over) {
647 				file->f_pos += bit_pos - start_bit_pos;
648 				goto success;
649 			}
650 			slots = GET_DENTRY_SLOTS(le16_to_cpu(de->name_len));
651 			bit_pos += slots;
652 		}
653 		bit_pos = 0;
654 		file->f_pos = (n + 1) * NR_DENTRY_IN_BLOCK;
655 		kunmap(dentry_page);
656 		f2fs_put_page(dentry_page, 1);
657 		dentry_page = NULL;
658 	}
659 success:
660 	if (dentry_page && !IS_ERR(dentry_page)) {
661 		kunmap(dentry_page);
662 		f2fs_put_page(dentry_page, 1);
663 	}
664 
665 	return 0;
666 }
667 
668 const struct file_operations f2fs_dir_operations = {
669 	.llseek		= generic_file_llseek,
670 	.read		= generic_read_dir,
671 	.readdir	= f2fs_readdir,
672 	.fsync		= f2fs_sync_file,
673 	.unlocked_ioctl	= f2fs_ioctl,
674 };
675