xref: /openbmc/linux/fs/f2fs/dir.c (revision 1c2f87c2)
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 
18 static 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 
24 static unsigned int dir_buckets(unsigned int level, int dir_level)
25 {
26 	if (level < MAX_DIR_HASH_DEPTH / 2)
27 		return 1 << (level + dir_level);
28 	else
29 		return 1 << ((MAX_DIR_HASH_DEPTH / 2 + dir_level) - 1);
30 }
31 
32 static 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 
40 static unsigned 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
52 static 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 
62 static void set_de_type(struct f2fs_dir_entry *de, struct inode *inode)
63 {
64 	umode_t mode = inode->i_mode;
65 	de->file_type = f2fs_type_by_mode[(mode & S_IFMT) >> S_SHIFT];
66 }
67 
68 static unsigned long dir_block_index(unsigned int level,
69 				int dir_level, unsigned int idx)
70 {
71 	unsigned long i;
72 	unsigned long bidx = 0;
73 
74 	for (i = 0; i < level; i++)
75 		bidx += dir_buckets(i, dir_level) * bucket_blocks(i);
76 	bidx += idx * bucket_blocks(level);
77 	return bidx;
78 }
79 
80 static bool early_match_name(const char *name, size_t namelen,
81 			f2fs_hash_t namehash, struct f2fs_dir_entry *de)
82 {
83 	if (le16_to_cpu(de->name_len) != namelen)
84 		return false;
85 
86 	if (de->hash_code != namehash)
87 		return false;
88 
89 	return true;
90 }
91 
92 static struct f2fs_dir_entry *find_in_block(struct page *dentry_page,
93 			const char *name, size_t namelen, int *max_slots,
94 			f2fs_hash_t namehash, struct page **res_page)
95 {
96 	struct f2fs_dir_entry *de;
97 	unsigned long bit_pos = 0;
98 	struct f2fs_dentry_block *dentry_blk = kmap(dentry_page);
99 	const void *dentry_bits = &dentry_blk->dentry_bitmap;
100 	int max_len = 0;
101 
102 	while (bit_pos < NR_DENTRY_IN_BLOCK) {
103 		if (!test_bit_le(bit_pos, dentry_bits)) {
104 			if (bit_pos == 0)
105 				max_len = 1;
106 			else if (!test_bit_le(bit_pos - 1, dentry_bits))
107 				max_len++;
108 			bit_pos++;
109 			continue;
110 		}
111 		de = &dentry_blk->dentry[bit_pos];
112 		if (early_match_name(name, namelen, namehash, de)) {
113 			if (!memcmp(dentry_blk->filename[bit_pos],
114 							name, namelen)) {
115 				*res_page = dentry_page;
116 				goto found;
117 			}
118 		}
119 		if (max_len > *max_slots) {
120 			*max_slots = max_len;
121 			max_len = 0;
122 		}
123 		bit_pos += GET_DENTRY_SLOTS(le16_to_cpu(de->name_len));
124 	}
125 
126 	de = NULL;
127 	kunmap(dentry_page);
128 found:
129 	if (max_len > *max_slots)
130 		*max_slots = max_len;
131 	return de;
132 }
133 
134 static struct f2fs_dir_entry *find_in_level(struct inode *dir,
135 		unsigned int level, const char *name, size_t namelen,
136 			f2fs_hash_t namehash, struct page **res_page)
137 {
138 	int s = GET_DENTRY_SLOTS(namelen);
139 	unsigned int nbucket, nblock;
140 	unsigned int bidx, end_block;
141 	struct page *dentry_page;
142 	struct f2fs_dir_entry *de = NULL;
143 	bool room = false;
144 	int max_slots = 0;
145 
146 	f2fs_bug_on(level > MAX_DIR_HASH_DEPTH);
147 
148 	nbucket = dir_buckets(level, F2FS_I(dir)->i_dir_level);
149 	nblock = bucket_blocks(level);
150 
151 	bidx = dir_block_index(level, F2FS_I(dir)->i_dir_level,
152 					le32_to_cpu(namehash) % nbucket);
153 	end_block = bidx + nblock;
154 
155 	for (; bidx < end_block; bidx++) {
156 		/* no need to allocate new dentry pages to all the indices */
157 		dentry_page = find_data_page(dir, bidx, true);
158 		if (IS_ERR(dentry_page)) {
159 			room = true;
160 			continue;
161 		}
162 
163 		de = find_in_block(dentry_page, name, namelen,
164 					&max_slots, namehash, res_page);
165 		if (de)
166 			break;
167 
168 		if (max_slots >= s)
169 			room = true;
170 		f2fs_put_page(dentry_page, 0);
171 	}
172 
173 	if (!de && room && F2FS_I(dir)->chash != namehash) {
174 		F2FS_I(dir)->chash = namehash;
175 		F2FS_I(dir)->clevel = level;
176 	}
177 
178 	return de;
179 }
180 
181 /*
182  * Find an entry in the specified directory with the wanted name.
183  * It returns the page where the entry was found (as a parameter - res_page),
184  * and the entry itself. Page is returned mapped and unlocked.
185  * Entry is guaranteed to be valid.
186  */
187 struct f2fs_dir_entry *f2fs_find_entry(struct inode *dir,
188 			struct qstr *child, struct page **res_page)
189 {
190 	const char *name = child->name;
191 	size_t namelen = child->len;
192 	unsigned long npages = dir_blocks(dir);
193 	struct f2fs_dir_entry *de = NULL;
194 	f2fs_hash_t name_hash;
195 	unsigned int max_depth;
196 	unsigned int level;
197 
198 	if (npages == 0)
199 		return NULL;
200 
201 	*res_page = NULL;
202 
203 	name_hash = f2fs_dentry_hash(name, namelen);
204 	max_depth = F2FS_I(dir)->i_current_depth;
205 
206 	for (level = 0; level < max_depth; level++) {
207 		de = find_in_level(dir, level, name,
208 				namelen, name_hash, res_page);
209 		if (de)
210 			break;
211 	}
212 	if (!de && F2FS_I(dir)->chash != name_hash) {
213 		F2FS_I(dir)->chash = name_hash;
214 		F2FS_I(dir)->clevel = level - 1;
215 	}
216 	return de;
217 }
218 
219 struct f2fs_dir_entry *f2fs_parent_dir(struct inode *dir, struct page **p)
220 {
221 	struct page *page;
222 	struct f2fs_dir_entry *de;
223 	struct f2fs_dentry_block *dentry_blk;
224 
225 	page = get_lock_data_page(dir, 0);
226 	if (IS_ERR(page))
227 		return NULL;
228 
229 	dentry_blk = kmap(page);
230 	de = &dentry_blk->dentry[1];
231 	*p = page;
232 	unlock_page(page);
233 	return de;
234 }
235 
236 ino_t f2fs_inode_by_name(struct inode *dir, struct qstr *qstr)
237 {
238 	ino_t res = 0;
239 	struct f2fs_dir_entry *de;
240 	struct page *page;
241 
242 	de = f2fs_find_entry(dir, qstr, &page);
243 	if (de) {
244 		res = le32_to_cpu(de->ino);
245 		kunmap(page);
246 		f2fs_put_page(page, 0);
247 	}
248 
249 	return res;
250 }
251 
252 void f2fs_set_link(struct inode *dir, struct f2fs_dir_entry *de,
253 		struct page *page, struct inode *inode)
254 {
255 	lock_page(page);
256 	f2fs_wait_on_page_writeback(page, DATA);
257 	de->ino = cpu_to_le32(inode->i_ino);
258 	set_de_type(de, inode);
259 	kunmap(page);
260 	set_page_dirty(page);
261 	dir->i_mtime = dir->i_ctime = CURRENT_TIME;
262 	mark_inode_dirty(dir);
263 
264 	f2fs_put_page(page, 1);
265 }
266 
267 static void init_dent_inode(const struct qstr *name, struct page *ipage)
268 {
269 	struct f2fs_inode *ri;
270 
271 	/* copy name info. to this inode page */
272 	ri = F2FS_INODE(ipage);
273 	ri->i_namelen = cpu_to_le32(name->len);
274 	memcpy(ri->i_name, name->name, name->len);
275 	set_page_dirty(ipage);
276 }
277 
278 int update_dent_inode(struct inode *inode, const struct qstr *name)
279 {
280 	struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
281 	struct page *page;
282 
283 	page = get_node_page(sbi, inode->i_ino);
284 	if (IS_ERR(page))
285 		return PTR_ERR(page);
286 
287 	init_dent_inode(name, page);
288 	f2fs_put_page(page, 1);
289 
290 	return 0;
291 }
292 
293 static int make_empty_dir(struct inode *inode,
294 		struct inode *parent, struct page *page)
295 {
296 	struct page *dentry_page;
297 	struct f2fs_dentry_block *dentry_blk;
298 	struct f2fs_dir_entry *de;
299 	void *kaddr;
300 
301 	dentry_page = get_new_data_page(inode, page, 0, true);
302 	if (IS_ERR(dentry_page))
303 		return PTR_ERR(dentry_page);
304 
305 	kaddr = kmap_atomic(dentry_page);
306 	dentry_blk = (struct f2fs_dentry_block *)kaddr;
307 
308 	de = &dentry_blk->dentry[0];
309 	de->name_len = cpu_to_le16(1);
310 	de->hash_code = 0;
311 	de->ino = cpu_to_le32(inode->i_ino);
312 	memcpy(dentry_blk->filename[0], ".", 1);
313 	set_de_type(de, inode);
314 
315 	de = &dentry_blk->dentry[1];
316 	de->hash_code = 0;
317 	de->name_len = cpu_to_le16(2);
318 	de->ino = cpu_to_le32(parent->i_ino);
319 	memcpy(dentry_blk->filename[1], "..", 2);
320 	set_de_type(de, inode);
321 
322 	test_and_set_bit_le(0, &dentry_blk->dentry_bitmap);
323 	test_and_set_bit_le(1, &dentry_blk->dentry_bitmap);
324 	kunmap_atomic(kaddr);
325 
326 	set_page_dirty(dentry_page);
327 	f2fs_put_page(dentry_page, 1);
328 	return 0;
329 }
330 
331 static struct page *init_inode_metadata(struct inode *inode,
332 		struct inode *dir, const struct qstr *name)
333 {
334 	struct page *page;
335 	int err;
336 
337 	if (is_inode_flag_set(F2FS_I(inode), FI_NEW_INODE)) {
338 		page = new_inode_page(inode, name);
339 		if (IS_ERR(page))
340 			return page;
341 
342 		if (S_ISDIR(inode->i_mode)) {
343 			err = make_empty_dir(inode, dir, page);
344 			if (err)
345 				goto error;
346 		}
347 
348 		err = f2fs_init_acl(inode, dir, page);
349 		if (err)
350 			goto put_error;
351 
352 		err = f2fs_init_security(inode, dir, name, page);
353 		if (err)
354 			goto put_error;
355 	} else {
356 		page = get_node_page(F2FS_SB(dir->i_sb), inode->i_ino);
357 		if (IS_ERR(page))
358 			return page;
359 
360 		set_cold_node(inode, page);
361 	}
362 
363 	init_dent_inode(name, page);
364 
365 	/*
366 	 * This file should be checkpointed during fsync.
367 	 * We lost i_pino from now on.
368 	 */
369 	if (is_inode_flag_set(F2FS_I(inode), FI_INC_LINK)) {
370 		file_lost_pino(inode);
371 		inc_nlink(inode);
372 	}
373 	return page;
374 
375 put_error:
376 	f2fs_put_page(page, 1);
377 	/* once the failed inode becomes a bad inode, i_mode is S_IFREG */
378 	truncate_inode_pages(&inode->i_data, 0);
379 	truncate_blocks(inode, 0);
380 	remove_dirty_dir_inode(inode);
381 error:
382 	remove_inode_page(inode);
383 	return ERR_PTR(err);
384 }
385 
386 static void update_parent_metadata(struct inode *dir, struct inode *inode,
387 						unsigned int current_depth)
388 {
389 	if (is_inode_flag_set(F2FS_I(inode), FI_NEW_INODE)) {
390 		if (S_ISDIR(inode->i_mode)) {
391 			inc_nlink(dir);
392 			set_inode_flag(F2FS_I(dir), FI_UPDATE_DIR);
393 		}
394 		clear_inode_flag(F2FS_I(inode), FI_NEW_INODE);
395 	}
396 	dir->i_mtime = dir->i_ctime = CURRENT_TIME;
397 	mark_inode_dirty(dir);
398 
399 	if (F2FS_I(dir)->i_current_depth != current_depth) {
400 		F2FS_I(dir)->i_current_depth = current_depth;
401 		set_inode_flag(F2FS_I(dir), FI_UPDATE_DIR);
402 	}
403 
404 	if (is_inode_flag_set(F2FS_I(inode), FI_INC_LINK))
405 		clear_inode_flag(F2FS_I(inode), FI_INC_LINK);
406 }
407 
408 static int room_for_filename(struct f2fs_dentry_block *dentry_blk, int slots)
409 {
410 	int bit_start = 0;
411 	int zero_start, zero_end;
412 next:
413 	zero_start = find_next_zero_bit_le(&dentry_blk->dentry_bitmap,
414 						NR_DENTRY_IN_BLOCK,
415 						bit_start);
416 	if (zero_start >= NR_DENTRY_IN_BLOCK)
417 		return NR_DENTRY_IN_BLOCK;
418 
419 	zero_end = find_next_bit_le(&dentry_blk->dentry_bitmap,
420 						NR_DENTRY_IN_BLOCK,
421 						zero_start);
422 	if (zero_end - zero_start >= slots)
423 		return zero_start;
424 
425 	bit_start = zero_end + 1;
426 
427 	if (zero_end + 1 >= NR_DENTRY_IN_BLOCK)
428 		return NR_DENTRY_IN_BLOCK;
429 	goto next;
430 }
431 
432 /*
433  * Caller should grab and release a rwsem by calling f2fs_lock_op() and
434  * f2fs_unlock_op().
435  */
436 int __f2fs_add_link(struct inode *dir, const struct qstr *name,
437 						struct inode *inode)
438 {
439 	unsigned int bit_pos;
440 	unsigned int level;
441 	unsigned int current_depth;
442 	unsigned long bidx, block;
443 	f2fs_hash_t dentry_hash;
444 	struct f2fs_dir_entry *de;
445 	unsigned int nbucket, nblock;
446 	size_t namelen = name->len;
447 	struct page *dentry_page = NULL;
448 	struct f2fs_dentry_block *dentry_blk = NULL;
449 	int slots = GET_DENTRY_SLOTS(namelen);
450 	struct page *page;
451 	int err = 0;
452 	int i;
453 
454 	dentry_hash = f2fs_dentry_hash(name->name, name->len);
455 	level = 0;
456 	current_depth = F2FS_I(dir)->i_current_depth;
457 	if (F2FS_I(dir)->chash == dentry_hash) {
458 		level = F2FS_I(dir)->clevel;
459 		F2FS_I(dir)->chash = 0;
460 	}
461 
462 start:
463 	if (unlikely(current_depth == MAX_DIR_HASH_DEPTH))
464 		return -ENOSPC;
465 
466 	/* Increase the depth, if required */
467 	if (level == current_depth)
468 		++current_depth;
469 
470 	nbucket = dir_buckets(level, F2FS_I(dir)->i_dir_level);
471 	nblock = bucket_blocks(level);
472 
473 	bidx = dir_block_index(level, F2FS_I(dir)->i_dir_level,
474 				(le32_to_cpu(dentry_hash) % nbucket));
475 
476 	for (block = bidx; block <= (bidx + nblock - 1); block++) {
477 		dentry_page = get_new_data_page(dir, NULL, block, true);
478 		if (IS_ERR(dentry_page))
479 			return PTR_ERR(dentry_page);
480 
481 		dentry_blk = kmap(dentry_page);
482 		bit_pos = room_for_filename(dentry_blk, slots);
483 		if (bit_pos < NR_DENTRY_IN_BLOCK)
484 			goto add_dentry;
485 
486 		kunmap(dentry_page);
487 		f2fs_put_page(dentry_page, 1);
488 	}
489 
490 	/* Move to next level to find the empty slot for new dentry */
491 	++level;
492 	goto start;
493 add_dentry:
494 	f2fs_wait_on_page_writeback(dentry_page, DATA);
495 
496 	down_write(&F2FS_I(inode)->i_sem);
497 	page = init_inode_metadata(inode, dir, name);
498 	if (IS_ERR(page)) {
499 		err = PTR_ERR(page);
500 		goto fail;
501 	}
502 	de = &dentry_blk->dentry[bit_pos];
503 	de->hash_code = dentry_hash;
504 	de->name_len = cpu_to_le16(namelen);
505 	memcpy(dentry_blk->filename[bit_pos], name->name, name->len);
506 	de->ino = cpu_to_le32(inode->i_ino);
507 	set_de_type(de, inode);
508 	for (i = 0; i < slots; i++)
509 		test_and_set_bit_le(bit_pos + i, &dentry_blk->dentry_bitmap);
510 	set_page_dirty(dentry_page);
511 
512 	/* we don't need to mark_inode_dirty now */
513 	F2FS_I(inode)->i_pino = dir->i_ino;
514 	update_inode(inode, page);
515 	f2fs_put_page(page, 1);
516 
517 	update_parent_metadata(dir, inode, current_depth);
518 fail:
519 	up_write(&F2FS_I(inode)->i_sem);
520 
521 	if (is_inode_flag_set(F2FS_I(dir), FI_UPDATE_DIR)) {
522 		update_inode_page(dir);
523 		clear_inode_flag(F2FS_I(dir), FI_UPDATE_DIR);
524 	}
525 	kunmap(dentry_page);
526 	f2fs_put_page(dentry_page, 1);
527 	return err;
528 }
529 
530 /*
531  * It only removes the dentry from the dentry page,corresponding name
532  * entry in name page does not need to be touched during deletion.
533  */
534 void f2fs_delete_entry(struct f2fs_dir_entry *dentry, struct page *page,
535 						struct inode *inode)
536 {
537 	struct	f2fs_dentry_block *dentry_blk;
538 	unsigned int bit_pos;
539 	struct address_space *mapping = page->mapping;
540 	struct inode *dir = mapping->host;
541 	int slots = GET_DENTRY_SLOTS(le16_to_cpu(dentry->name_len));
542 	void *kaddr = page_address(page);
543 	int i;
544 
545 	lock_page(page);
546 	f2fs_wait_on_page_writeback(page, DATA);
547 
548 	dentry_blk = (struct f2fs_dentry_block *)kaddr;
549 	bit_pos = dentry - (struct f2fs_dir_entry *)dentry_blk->dentry;
550 	for (i = 0; i < slots; i++)
551 		test_and_clear_bit_le(bit_pos + i, &dentry_blk->dentry_bitmap);
552 
553 	/* Let's check and deallocate this dentry page */
554 	bit_pos = find_next_bit_le(&dentry_blk->dentry_bitmap,
555 			NR_DENTRY_IN_BLOCK,
556 			0);
557 	kunmap(page); /* kunmap - pair of f2fs_find_entry */
558 	set_page_dirty(page);
559 
560 	dir->i_ctime = dir->i_mtime = CURRENT_TIME;
561 
562 	if (inode) {
563 		struct f2fs_sb_info *sbi = F2FS_SB(dir->i_sb);
564 
565 		down_write(&F2FS_I(inode)->i_sem);
566 
567 		if (S_ISDIR(inode->i_mode)) {
568 			drop_nlink(dir);
569 			update_inode_page(dir);
570 		}
571 		inode->i_ctime = CURRENT_TIME;
572 		drop_nlink(inode);
573 		if (S_ISDIR(inode->i_mode)) {
574 			drop_nlink(inode);
575 			i_size_write(inode, 0);
576 		}
577 		up_write(&F2FS_I(inode)->i_sem);
578 		update_inode_page(inode);
579 
580 		if (inode->i_nlink == 0)
581 			add_orphan_inode(sbi, inode->i_ino);
582 		else
583 			release_orphan_inode(sbi);
584 	}
585 
586 	if (bit_pos == NR_DENTRY_IN_BLOCK) {
587 		truncate_hole(dir, page->index, page->index + 1);
588 		clear_page_dirty_for_io(page);
589 		ClearPageUptodate(page);
590 		inode_dec_dirty_dents(dir);
591 	}
592 	f2fs_put_page(page, 1);
593 }
594 
595 bool f2fs_empty_dir(struct inode *dir)
596 {
597 	unsigned long bidx;
598 	struct page *dentry_page;
599 	unsigned int bit_pos;
600 	struct	f2fs_dentry_block *dentry_blk;
601 	unsigned long nblock = dir_blocks(dir);
602 
603 	for (bidx = 0; bidx < nblock; bidx++) {
604 		void *kaddr;
605 		dentry_page = get_lock_data_page(dir, bidx);
606 		if (IS_ERR(dentry_page)) {
607 			if (PTR_ERR(dentry_page) == -ENOENT)
608 				continue;
609 			else
610 				return false;
611 		}
612 
613 		kaddr = kmap_atomic(dentry_page);
614 		dentry_blk = (struct f2fs_dentry_block *)kaddr;
615 		if (bidx == 0)
616 			bit_pos = 2;
617 		else
618 			bit_pos = 0;
619 		bit_pos = find_next_bit_le(&dentry_blk->dentry_bitmap,
620 						NR_DENTRY_IN_BLOCK,
621 						bit_pos);
622 		kunmap_atomic(kaddr);
623 
624 		f2fs_put_page(dentry_page, 1);
625 
626 		if (bit_pos < NR_DENTRY_IN_BLOCK)
627 			return false;
628 	}
629 	return true;
630 }
631 
632 static int f2fs_readdir(struct file *file, struct dir_context *ctx)
633 {
634 	struct inode *inode = file_inode(file);
635 	unsigned long npages = dir_blocks(inode);
636 	unsigned int bit_pos = 0;
637 	struct f2fs_dentry_block *dentry_blk = NULL;
638 	struct f2fs_dir_entry *de = NULL;
639 	struct page *dentry_page = NULL;
640 	unsigned int n = ((unsigned long)ctx->pos / NR_DENTRY_IN_BLOCK);
641 	unsigned char d_type = DT_UNKNOWN;
642 
643 	bit_pos = ((unsigned long)ctx->pos % NR_DENTRY_IN_BLOCK);
644 
645 	for (; n < npages; n++) {
646 		dentry_page = get_lock_data_page(inode, n);
647 		if (IS_ERR(dentry_page))
648 			continue;
649 
650 		dentry_blk = kmap(dentry_page);
651 		while (bit_pos < NR_DENTRY_IN_BLOCK) {
652 			bit_pos = find_next_bit_le(&dentry_blk->dentry_bitmap,
653 							NR_DENTRY_IN_BLOCK,
654 							bit_pos);
655 			if (bit_pos >= NR_DENTRY_IN_BLOCK)
656 				break;
657 
658 			de = &dentry_blk->dentry[bit_pos];
659 			if (de->file_type < F2FS_FT_MAX)
660 				d_type = f2fs_filetype_table[de->file_type];
661 			else
662 				d_type = DT_UNKNOWN;
663 			if (!dir_emit(ctx,
664 					dentry_blk->filename[bit_pos],
665 					le16_to_cpu(de->name_len),
666 					le32_to_cpu(de->ino), d_type))
667 				goto stop;
668 
669 			bit_pos += GET_DENTRY_SLOTS(le16_to_cpu(de->name_len));
670 			ctx->pos = n * NR_DENTRY_IN_BLOCK + bit_pos;
671 		}
672 		bit_pos = 0;
673 		ctx->pos = (n + 1) * NR_DENTRY_IN_BLOCK;
674 		kunmap(dentry_page);
675 		f2fs_put_page(dentry_page, 1);
676 		dentry_page = NULL;
677 	}
678 stop:
679 	if (dentry_page && !IS_ERR(dentry_page)) {
680 		kunmap(dentry_page);
681 		f2fs_put_page(dentry_page, 1);
682 	}
683 
684 	return 0;
685 }
686 
687 const struct file_operations f2fs_dir_operations = {
688 	.llseek		= generic_file_llseek,
689 	.read		= generic_read_dir,
690 	.iterate	= f2fs_readdir,
691 	.fsync		= f2fs_sync_file,
692 	.unlocked_ioctl	= f2fs_ioctl,
693 };
694