xref: /openbmc/linux/fs/f2fs/dir.c (revision aac5987a)
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_SIZE - 1))
21 							>> PAGE_SHIFT;
22 }
23 
24 static 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 
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 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 void set_de_type(struct f2fs_dir_entry *de, umode_t mode)
62 {
63 	de->file_type = f2fs_type_by_mode[(mode & S_IFMT) >> S_SHIFT];
64 }
65 
66 unsigned char get_de_type(struct f2fs_dir_entry *de)
67 {
68 	if (de->file_type < F2FS_FT_MAX)
69 		return f2fs_filetype_table[de->file_type];
70 	return DT_UNKNOWN;
71 }
72 
73 static unsigned long dir_block_index(unsigned int level,
74 				int dir_level, unsigned int idx)
75 {
76 	unsigned long i;
77 	unsigned long bidx = 0;
78 
79 	for (i = 0; i < level; i++)
80 		bidx += dir_buckets(i, dir_level) * bucket_blocks(i);
81 	bidx += idx * bucket_blocks(level);
82 	return bidx;
83 }
84 
85 static struct f2fs_dir_entry *find_in_block(struct page *dentry_page,
86 				struct fscrypt_name *fname,
87 				f2fs_hash_t namehash,
88 				int *max_slots,
89 				struct page **res_page)
90 {
91 	struct f2fs_dentry_block *dentry_blk;
92 	struct f2fs_dir_entry *de;
93 	struct f2fs_dentry_ptr d;
94 
95 	dentry_blk = (struct f2fs_dentry_block *)kmap(dentry_page);
96 
97 	make_dentry_ptr(NULL, &d, (void *)dentry_blk, 1);
98 	de = find_target_dentry(fname, namehash, max_slots, &d);
99 	if (de)
100 		*res_page = dentry_page;
101 	else
102 		kunmap(dentry_page);
103 
104 	return de;
105 }
106 
107 struct f2fs_dir_entry *find_target_dentry(struct fscrypt_name *fname,
108 			f2fs_hash_t namehash, int *max_slots,
109 			struct f2fs_dentry_ptr *d)
110 {
111 	struct f2fs_dir_entry *de;
112 	unsigned long bit_pos = 0;
113 	int max_len = 0;
114 	struct fscrypt_str de_name = FSTR_INIT(NULL, 0);
115 	struct fscrypt_str *name = &fname->disk_name;
116 
117 	if (max_slots)
118 		*max_slots = 0;
119 	while (bit_pos < d->max) {
120 		if (!test_bit_le(bit_pos, d->bitmap)) {
121 			bit_pos++;
122 			max_len++;
123 			continue;
124 		}
125 
126 		de = &d->dentry[bit_pos];
127 
128 		if (unlikely(!de->name_len)) {
129 			bit_pos++;
130 			continue;
131 		}
132 
133 		/* encrypted case */
134 		de_name.name = d->filename[bit_pos];
135 		de_name.len = le16_to_cpu(de->name_len);
136 
137 		/* show encrypted name */
138 		if (fname->hash) {
139 			if (de->hash_code == cpu_to_le32(fname->hash))
140 				goto found;
141 		} else if (de_name.len == name->len &&
142 			de->hash_code == namehash &&
143 			!memcmp(de_name.name, name->name, name->len))
144 			goto found;
145 
146 		if (max_slots && max_len > *max_slots)
147 			*max_slots = max_len;
148 		max_len = 0;
149 
150 		bit_pos += GET_DENTRY_SLOTS(le16_to_cpu(de->name_len));
151 	}
152 
153 	de = NULL;
154 found:
155 	if (max_slots && max_len > *max_slots)
156 		*max_slots = max_len;
157 	return de;
158 }
159 
160 static struct f2fs_dir_entry *find_in_level(struct inode *dir,
161 					unsigned int level,
162 					struct fscrypt_name *fname,
163 					struct page **res_page)
164 {
165 	struct qstr name = FSTR_TO_QSTR(&fname->disk_name);
166 	int s = GET_DENTRY_SLOTS(name.len);
167 	unsigned int nbucket, nblock;
168 	unsigned int bidx, end_block;
169 	struct page *dentry_page;
170 	struct f2fs_dir_entry *de = NULL;
171 	bool room = false;
172 	int max_slots;
173 	f2fs_hash_t namehash;
174 
175 	if(fname->hash)
176 		namehash = cpu_to_le32(fname->hash);
177 	else
178 		namehash = f2fs_dentry_hash(&name);
179 
180 	nbucket = dir_buckets(level, F2FS_I(dir)->i_dir_level);
181 	nblock = bucket_blocks(level);
182 
183 	bidx = dir_block_index(level, F2FS_I(dir)->i_dir_level,
184 					le32_to_cpu(namehash) % nbucket);
185 	end_block = bidx + nblock;
186 
187 	for (; bidx < end_block; bidx++) {
188 		/* no need to allocate new dentry pages to all the indices */
189 		dentry_page = find_data_page(dir, bidx);
190 		if (IS_ERR(dentry_page)) {
191 			if (PTR_ERR(dentry_page) == -ENOENT) {
192 				room = true;
193 				continue;
194 			} else {
195 				*res_page = dentry_page;
196 				break;
197 			}
198 		}
199 
200 		de = find_in_block(dentry_page, fname, namehash, &max_slots,
201 								res_page);
202 		if (de)
203 			break;
204 
205 		if (max_slots >= s)
206 			room = true;
207 		f2fs_put_page(dentry_page, 0);
208 	}
209 
210 	/* This is to increase the speed of f2fs_create */
211 	if (!de && room) {
212 		F2FS_I(dir)->task = current;
213 		if (F2FS_I(dir)->chash != namehash) {
214 			F2FS_I(dir)->chash = namehash;
215 			F2FS_I(dir)->clevel = level;
216 		}
217 	}
218 
219 	return de;
220 }
221 
222 struct f2fs_dir_entry *__f2fs_find_entry(struct inode *dir,
223 			struct fscrypt_name *fname, struct page **res_page)
224 {
225 	unsigned long npages = dir_blocks(dir);
226 	struct f2fs_dir_entry *de = NULL;
227 	unsigned int max_depth;
228 	unsigned int level;
229 
230 	if (f2fs_has_inline_dentry(dir)) {
231 		*res_page = NULL;
232 		de = find_in_inline_dir(dir, fname, res_page);
233 		goto out;
234 	}
235 
236 	if (npages == 0) {
237 		*res_page = NULL;
238 		goto out;
239 	}
240 
241 	max_depth = F2FS_I(dir)->i_current_depth;
242 	if (unlikely(max_depth > MAX_DIR_HASH_DEPTH)) {
243 		f2fs_msg(F2FS_I_SB(dir)->sb, KERN_WARNING,
244 				"Corrupted max_depth of %lu: %u",
245 				dir->i_ino, max_depth);
246 		max_depth = MAX_DIR_HASH_DEPTH;
247 		f2fs_i_depth_write(dir, max_depth);
248 	}
249 
250 	for (level = 0; level < max_depth; level++) {
251 		*res_page = NULL;
252 		de = find_in_level(dir, level, fname, res_page);
253 		if (de || IS_ERR(*res_page))
254 			break;
255 	}
256 out:
257 	return de;
258 }
259 
260 /*
261  * Find an entry in the specified directory with the wanted name.
262  * It returns the page where the entry was found (as a parameter - res_page),
263  * and the entry itself. Page is returned mapped and unlocked.
264  * Entry is guaranteed to be valid.
265  */
266 struct f2fs_dir_entry *f2fs_find_entry(struct inode *dir,
267 			const struct qstr *child, struct page **res_page)
268 {
269 	struct f2fs_dir_entry *de = NULL;
270 	struct fscrypt_name fname;
271 	int err;
272 
273 	err = fscrypt_setup_filename(dir, child, 1, &fname);
274 	if (err) {
275 		if (err == -ENOENT)
276 			*res_page = NULL;
277 		else
278 			*res_page = ERR_PTR(err);
279 		return NULL;
280 	}
281 
282 	de = __f2fs_find_entry(dir, &fname, res_page);
283 
284 	fscrypt_free_filename(&fname);
285 	return de;
286 }
287 
288 struct f2fs_dir_entry *f2fs_parent_dir(struct inode *dir, struct page **p)
289 {
290 	struct qstr dotdot = QSTR_INIT("..", 2);
291 
292 	return f2fs_find_entry(dir, &dotdot, p);
293 }
294 
295 ino_t f2fs_inode_by_name(struct inode *dir, const struct qstr *qstr,
296 							struct page **page)
297 {
298 	ino_t res = 0;
299 	struct f2fs_dir_entry *de;
300 
301 	de = f2fs_find_entry(dir, qstr, page);
302 	if (de) {
303 		res = le32_to_cpu(de->ino);
304 		f2fs_dentry_kunmap(dir, *page);
305 		f2fs_put_page(*page, 0);
306 	}
307 
308 	return res;
309 }
310 
311 void f2fs_set_link(struct inode *dir, struct f2fs_dir_entry *de,
312 		struct page *page, struct inode *inode)
313 {
314 	enum page_type type = f2fs_has_inline_dentry(dir) ? NODE : DATA;
315 	lock_page(page);
316 	f2fs_wait_on_page_writeback(page, type, true);
317 	de->ino = cpu_to_le32(inode->i_ino);
318 	set_de_type(de, inode->i_mode);
319 	f2fs_dentry_kunmap(dir, page);
320 	set_page_dirty(page);
321 
322 	dir->i_mtime = dir->i_ctime = current_time(dir);
323 	f2fs_mark_inode_dirty_sync(dir, false);
324 	f2fs_put_page(page, 1);
325 }
326 
327 static void init_dent_inode(const struct qstr *name, struct page *ipage)
328 {
329 	struct f2fs_inode *ri;
330 
331 	f2fs_wait_on_page_writeback(ipage, NODE, true);
332 
333 	/* copy name info. to this inode page */
334 	ri = F2FS_INODE(ipage);
335 	ri->i_namelen = cpu_to_le32(name->len);
336 	memcpy(ri->i_name, name->name, name->len);
337 	set_page_dirty(ipage);
338 }
339 
340 int update_dent_inode(struct inode *inode, struct inode *to,
341 					const struct qstr *name)
342 {
343 	struct page *page;
344 
345 	if (file_enc_name(to))
346 		return 0;
347 
348 	page = get_node_page(F2FS_I_SB(inode), inode->i_ino);
349 	if (IS_ERR(page))
350 		return PTR_ERR(page);
351 
352 	init_dent_inode(name, page);
353 	f2fs_put_page(page, 1);
354 
355 	return 0;
356 }
357 
358 void do_make_empty_dir(struct inode *inode, struct inode *parent,
359 					struct f2fs_dentry_ptr *d)
360 {
361 	struct qstr dot = QSTR_INIT(".", 1);
362 	struct qstr dotdot = QSTR_INIT("..", 2);
363 
364 	/* update dirent of "." */
365 	f2fs_update_dentry(inode->i_ino, inode->i_mode, d, &dot, 0, 0);
366 
367 	/* update dirent of ".." */
368 	f2fs_update_dentry(parent->i_ino, parent->i_mode, d, &dotdot, 0, 1);
369 }
370 
371 static int make_empty_dir(struct inode *inode,
372 		struct inode *parent, struct page *page)
373 {
374 	struct page *dentry_page;
375 	struct f2fs_dentry_block *dentry_blk;
376 	struct f2fs_dentry_ptr d;
377 
378 	if (f2fs_has_inline_dentry(inode))
379 		return make_empty_inline_dir(inode, parent, page);
380 
381 	dentry_page = get_new_data_page(inode, page, 0, true);
382 	if (IS_ERR(dentry_page))
383 		return PTR_ERR(dentry_page);
384 
385 	dentry_blk = kmap_atomic(dentry_page);
386 
387 	make_dentry_ptr(NULL, &d, (void *)dentry_blk, 1);
388 	do_make_empty_dir(inode, parent, &d);
389 
390 	kunmap_atomic(dentry_blk);
391 
392 	set_page_dirty(dentry_page);
393 	f2fs_put_page(dentry_page, 1);
394 	return 0;
395 }
396 
397 struct page *init_inode_metadata(struct inode *inode, struct inode *dir,
398 			const struct qstr *new_name, const struct qstr *orig_name,
399 			struct page *dpage)
400 {
401 	struct page *page;
402 	int err;
403 
404 	if (is_inode_flag_set(inode, FI_NEW_INODE)) {
405 		page = new_inode_page(inode);
406 		if (IS_ERR(page))
407 			return page;
408 
409 		if (S_ISDIR(inode->i_mode)) {
410 			/* in order to handle error case */
411 			get_page(page);
412 			err = make_empty_dir(inode, dir, page);
413 			if (err) {
414 				lock_page(page);
415 				goto put_error;
416 			}
417 			put_page(page);
418 		}
419 
420 		err = f2fs_init_acl(inode, dir, page, dpage);
421 		if (err)
422 			goto put_error;
423 
424 		err = f2fs_init_security(inode, dir, orig_name, page);
425 		if (err)
426 			goto put_error;
427 
428 		if (f2fs_encrypted_inode(dir) && f2fs_may_encrypt(inode)) {
429 			err = fscrypt_inherit_context(dir, inode, page, false);
430 			if (err)
431 				goto put_error;
432 		}
433 	} else {
434 		page = get_node_page(F2FS_I_SB(dir), inode->i_ino);
435 		if (IS_ERR(page))
436 			return page;
437 
438 		set_cold_node(inode, page);
439 	}
440 
441 	if (new_name)
442 		init_dent_inode(new_name, page);
443 
444 	/*
445 	 * This file should be checkpointed during fsync.
446 	 * We lost i_pino from now on.
447 	 */
448 	if (is_inode_flag_set(inode, FI_INC_LINK)) {
449 		file_lost_pino(inode);
450 		/*
451 		 * If link the tmpfile to alias through linkat path,
452 		 * we should remove this inode from orphan list.
453 		 */
454 		if (inode->i_nlink == 0)
455 			remove_orphan_inode(F2FS_I_SB(dir), inode->i_ino);
456 		f2fs_i_links_write(inode, true);
457 	}
458 	return page;
459 
460 put_error:
461 	clear_nlink(inode);
462 	update_inode(inode, page);
463 	f2fs_put_page(page, 1);
464 	return ERR_PTR(err);
465 }
466 
467 void update_parent_metadata(struct inode *dir, struct inode *inode,
468 						unsigned int current_depth)
469 {
470 	if (inode && is_inode_flag_set(inode, FI_NEW_INODE)) {
471 		if (S_ISDIR(inode->i_mode))
472 			f2fs_i_links_write(dir, true);
473 		clear_inode_flag(inode, FI_NEW_INODE);
474 	}
475 	dir->i_mtime = dir->i_ctime = current_time(dir);
476 	f2fs_mark_inode_dirty_sync(dir, false);
477 
478 	if (F2FS_I(dir)->i_current_depth != current_depth)
479 		f2fs_i_depth_write(dir, current_depth);
480 
481 	if (inode && is_inode_flag_set(inode, FI_INC_LINK))
482 		clear_inode_flag(inode, FI_INC_LINK);
483 }
484 
485 int room_for_filename(const void *bitmap, int slots, int max_slots)
486 {
487 	int bit_start = 0;
488 	int zero_start, zero_end;
489 next:
490 	zero_start = find_next_zero_bit_le(bitmap, max_slots, bit_start);
491 	if (zero_start >= max_slots)
492 		return max_slots;
493 
494 	zero_end = find_next_bit_le(bitmap, max_slots, zero_start);
495 	if (zero_end - zero_start >= slots)
496 		return zero_start;
497 
498 	bit_start = zero_end + 1;
499 
500 	if (zero_end + 1 >= max_slots)
501 		return max_slots;
502 	goto next;
503 }
504 
505 void f2fs_update_dentry(nid_t ino, umode_t mode, struct f2fs_dentry_ptr *d,
506 				const struct qstr *name, f2fs_hash_t name_hash,
507 				unsigned int bit_pos)
508 {
509 	struct f2fs_dir_entry *de;
510 	int slots = GET_DENTRY_SLOTS(name->len);
511 	int i;
512 
513 	de = &d->dentry[bit_pos];
514 	de->hash_code = name_hash;
515 	de->name_len = cpu_to_le16(name->len);
516 	memcpy(d->filename[bit_pos], name->name, name->len);
517 	de->ino = cpu_to_le32(ino);
518 	set_de_type(de, mode);
519 	for (i = 0; i < slots; i++) {
520 		__set_bit_le(bit_pos + i, (void *)d->bitmap);
521 		/* avoid wrong garbage data for readdir */
522 		if (i)
523 			(de + i)->name_len = 0;
524 	}
525 }
526 
527 int f2fs_add_regular_entry(struct inode *dir, const struct qstr *new_name,
528 				const struct qstr *orig_name,
529 				struct inode *inode, nid_t ino, umode_t mode)
530 {
531 	unsigned int bit_pos;
532 	unsigned int level;
533 	unsigned int current_depth;
534 	unsigned long bidx, block;
535 	f2fs_hash_t dentry_hash;
536 	unsigned int nbucket, nblock;
537 	struct page *dentry_page = NULL;
538 	struct f2fs_dentry_block *dentry_blk = NULL;
539 	struct f2fs_dentry_ptr d;
540 	struct page *page = NULL;
541 	int slots, err = 0;
542 
543 	level = 0;
544 	slots = GET_DENTRY_SLOTS(new_name->len);
545 	dentry_hash = f2fs_dentry_hash(new_name);
546 
547 	current_depth = F2FS_I(dir)->i_current_depth;
548 	if (F2FS_I(dir)->chash == dentry_hash) {
549 		level = F2FS_I(dir)->clevel;
550 		F2FS_I(dir)->chash = 0;
551 	}
552 
553 start:
554 #ifdef CONFIG_F2FS_FAULT_INJECTION
555 	if (time_to_inject(F2FS_I_SB(dir), FAULT_DIR_DEPTH)) {
556 		f2fs_show_injection_info(FAULT_DIR_DEPTH);
557 		return -ENOSPC;
558 	}
559 #endif
560 	if (unlikely(current_depth == MAX_DIR_HASH_DEPTH))
561 		return -ENOSPC;
562 
563 	/* Increase the depth, if required */
564 	if (level == current_depth)
565 		++current_depth;
566 
567 	nbucket = dir_buckets(level, F2FS_I(dir)->i_dir_level);
568 	nblock = bucket_blocks(level);
569 
570 	bidx = dir_block_index(level, F2FS_I(dir)->i_dir_level,
571 				(le32_to_cpu(dentry_hash) % nbucket));
572 
573 	for (block = bidx; block <= (bidx + nblock - 1); block++) {
574 		dentry_page = get_new_data_page(dir, NULL, block, true);
575 		if (IS_ERR(dentry_page))
576 			return PTR_ERR(dentry_page);
577 
578 		dentry_blk = kmap(dentry_page);
579 		bit_pos = room_for_filename(&dentry_blk->dentry_bitmap,
580 						slots, NR_DENTRY_IN_BLOCK);
581 		if (bit_pos < NR_DENTRY_IN_BLOCK)
582 			goto add_dentry;
583 
584 		kunmap(dentry_page);
585 		f2fs_put_page(dentry_page, 1);
586 	}
587 
588 	/* Move to next level to find the empty slot for new dentry */
589 	++level;
590 	goto start;
591 add_dentry:
592 	f2fs_wait_on_page_writeback(dentry_page, DATA, true);
593 
594 	if (inode) {
595 		down_write(&F2FS_I(inode)->i_sem);
596 		page = init_inode_metadata(inode, dir, new_name,
597 						orig_name, NULL);
598 		if (IS_ERR(page)) {
599 			err = PTR_ERR(page);
600 			goto fail;
601 		}
602 		if (f2fs_encrypted_inode(dir))
603 			file_set_enc_name(inode);
604 	}
605 
606 	make_dentry_ptr(NULL, &d, (void *)dentry_blk, 1);
607 	f2fs_update_dentry(ino, mode, &d, new_name, dentry_hash, bit_pos);
608 
609 	set_page_dirty(dentry_page);
610 
611 	if (inode) {
612 		f2fs_i_pino_write(inode, dir->i_ino);
613 		f2fs_put_page(page, 1);
614 	}
615 
616 	update_parent_metadata(dir, inode, current_depth);
617 fail:
618 	if (inode)
619 		up_write(&F2FS_I(inode)->i_sem);
620 
621 	kunmap(dentry_page);
622 	f2fs_put_page(dentry_page, 1);
623 
624 	return err;
625 }
626 
627 int __f2fs_do_add_link(struct inode *dir, struct fscrypt_name *fname,
628 				struct inode *inode, nid_t ino, umode_t mode)
629 {
630 	struct qstr new_name;
631 	int err = -EAGAIN;
632 
633 	new_name.name = fname_name(fname);
634 	new_name.len = fname_len(fname);
635 
636 	if (f2fs_has_inline_dentry(dir))
637 		err = f2fs_add_inline_entry(dir, &new_name, fname->usr_fname,
638 							inode, ino, mode);
639 	if (err == -EAGAIN)
640 		err = f2fs_add_regular_entry(dir, &new_name, fname->usr_fname,
641 							inode, ino, mode);
642 
643 	f2fs_update_time(F2FS_I_SB(dir), REQ_TIME);
644 	return err;
645 }
646 
647 /*
648  * Caller should grab and release a rwsem by calling f2fs_lock_op() and
649  * f2fs_unlock_op().
650  */
651 int __f2fs_add_link(struct inode *dir, const struct qstr *name,
652 				struct inode *inode, nid_t ino, umode_t mode)
653 {
654 	struct fscrypt_name fname;
655 	struct page *page = NULL;
656 	struct f2fs_dir_entry *de = NULL;
657 	int err;
658 
659 	err = fscrypt_setup_filename(dir, name, 0, &fname);
660 	if (err)
661 		return err;
662 
663 	/*
664 	 * An immature stakable filesystem shows a race condition between lookup
665 	 * and create. If we have same task when doing lookup and create, it's
666 	 * definitely fine as expected by VFS normally. Otherwise, let's just
667 	 * verify on-disk dentry one more time, which guarantees filesystem
668 	 * consistency more.
669 	 */
670 	if (current != F2FS_I(dir)->task) {
671 		de = __f2fs_find_entry(dir, &fname, &page);
672 		F2FS_I(dir)->task = NULL;
673 	}
674 	if (de) {
675 		f2fs_dentry_kunmap(dir, page);
676 		f2fs_put_page(page, 0);
677 		err = -EEXIST;
678 	} else if (IS_ERR(page)) {
679 		err = PTR_ERR(page);
680 	} else {
681 		err = __f2fs_do_add_link(dir, &fname, inode, ino, mode);
682 	}
683 	fscrypt_free_filename(&fname);
684 	return err;
685 }
686 
687 int f2fs_do_tmpfile(struct inode *inode, struct inode *dir)
688 {
689 	struct page *page;
690 	int err = 0;
691 
692 	down_write(&F2FS_I(inode)->i_sem);
693 	page = init_inode_metadata(inode, dir, NULL, NULL, NULL);
694 	if (IS_ERR(page)) {
695 		err = PTR_ERR(page);
696 		goto fail;
697 	}
698 	f2fs_put_page(page, 1);
699 
700 	clear_inode_flag(inode, FI_NEW_INODE);
701 fail:
702 	up_write(&F2FS_I(inode)->i_sem);
703 	f2fs_update_time(F2FS_I_SB(inode), REQ_TIME);
704 	return err;
705 }
706 
707 void f2fs_drop_nlink(struct inode *dir, struct inode *inode)
708 {
709 	struct f2fs_sb_info *sbi = F2FS_I_SB(dir);
710 
711 	down_write(&F2FS_I(inode)->i_sem);
712 
713 	if (S_ISDIR(inode->i_mode))
714 		f2fs_i_links_write(dir, false);
715 	inode->i_ctime = current_time(inode);
716 
717 	f2fs_i_links_write(inode, false);
718 	if (S_ISDIR(inode->i_mode)) {
719 		f2fs_i_links_write(inode, false);
720 		f2fs_i_size_write(inode, 0);
721 	}
722 	up_write(&F2FS_I(inode)->i_sem);
723 
724 	if (inode->i_nlink == 0)
725 		add_orphan_inode(inode);
726 	else
727 		release_orphan_inode(sbi);
728 }
729 
730 /*
731  * It only removes the dentry from the dentry page, corresponding name
732  * entry in name page does not need to be touched during deletion.
733  */
734 void f2fs_delete_entry(struct f2fs_dir_entry *dentry, struct page *page,
735 					struct inode *dir, struct inode *inode)
736 {
737 	struct	f2fs_dentry_block *dentry_blk;
738 	unsigned int bit_pos;
739 	int slots = GET_DENTRY_SLOTS(le16_to_cpu(dentry->name_len));
740 	int i;
741 
742 	f2fs_update_time(F2FS_I_SB(dir), REQ_TIME);
743 
744 	if (f2fs_has_inline_dentry(dir))
745 		return f2fs_delete_inline_entry(dentry, page, dir, inode);
746 
747 	lock_page(page);
748 	f2fs_wait_on_page_writeback(page, DATA, true);
749 
750 	dentry_blk = page_address(page);
751 	bit_pos = dentry - dentry_blk->dentry;
752 	for (i = 0; i < slots; i++)
753 		clear_bit_le(bit_pos + i, &dentry_blk->dentry_bitmap);
754 
755 	/* Let's check and deallocate this dentry page */
756 	bit_pos = find_next_bit_le(&dentry_blk->dentry_bitmap,
757 			NR_DENTRY_IN_BLOCK,
758 			0);
759 	kunmap(page); /* kunmap - pair of f2fs_find_entry */
760 	set_page_dirty(page);
761 
762 	dir->i_ctime = dir->i_mtime = current_time(dir);
763 	f2fs_mark_inode_dirty_sync(dir, false);
764 
765 	if (inode)
766 		f2fs_drop_nlink(dir, inode);
767 
768 	if (bit_pos == NR_DENTRY_IN_BLOCK &&
769 			!truncate_hole(dir, page->index, page->index + 1)) {
770 		clear_page_dirty_for_io(page);
771 		ClearPagePrivate(page);
772 		ClearPageUptodate(page);
773 		inode_dec_dirty_pages(dir);
774 		remove_dirty_inode(dir);
775 	}
776 	f2fs_put_page(page, 1);
777 }
778 
779 bool f2fs_empty_dir(struct inode *dir)
780 {
781 	unsigned long bidx;
782 	struct page *dentry_page;
783 	unsigned int bit_pos;
784 	struct f2fs_dentry_block *dentry_blk;
785 	unsigned long nblock = dir_blocks(dir);
786 
787 	if (f2fs_has_inline_dentry(dir))
788 		return f2fs_empty_inline_dir(dir);
789 
790 	for (bidx = 0; bidx < nblock; bidx++) {
791 		dentry_page = get_lock_data_page(dir, bidx, false);
792 		if (IS_ERR(dentry_page)) {
793 			if (PTR_ERR(dentry_page) == -ENOENT)
794 				continue;
795 			else
796 				return false;
797 		}
798 
799 		dentry_blk = kmap_atomic(dentry_page);
800 		if (bidx == 0)
801 			bit_pos = 2;
802 		else
803 			bit_pos = 0;
804 		bit_pos = find_next_bit_le(&dentry_blk->dentry_bitmap,
805 						NR_DENTRY_IN_BLOCK,
806 						bit_pos);
807 		kunmap_atomic(dentry_blk);
808 
809 		f2fs_put_page(dentry_page, 1);
810 
811 		if (bit_pos < NR_DENTRY_IN_BLOCK)
812 			return false;
813 	}
814 	return true;
815 }
816 
817 int f2fs_fill_dentries(struct dir_context *ctx, struct f2fs_dentry_ptr *d,
818 			unsigned int start_pos, struct fscrypt_str *fstr)
819 {
820 	unsigned char d_type = DT_UNKNOWN;
821 	unsigned int bit_pos;
822 	struct f2fs_dir_entry *de = NULL;
823 	struct fscrypt_str de_name = FSTR_INIT(NULL, 0);
824 
825 	bit_pos = ((unsigned long)ctx->pos % d->max);
826 
827 	while (bit_pos < d->max) {
828 		bit_pos = find_next_bit_le(d->bitmap, d->max, bit_pos);
829 		if (bit_pos >= d->max)
830 			break;
831 
832 		de = &d->dentry[bit_pos];
833 		if (de->name_len == 0) {
834 			bit_pos++;
835 			ctx->pos = start_pos + bit_pos;
836 			continue;
837 		}
838 
839 		d_type = get_de_type(de);
840 
841 		de_name.name = d->filename[bit_pos];
842 		de_name.len = le16_to_cpu(de->name_len);
843 
844 		if (f2fs_encrypted_inode(d->inode)) {
845 			int save_len = fstr->len;
846 			int err;
847 
848 			err = fscrypt_fname_disk_to_usr(d->inode,
849 						(u32)de->hash_code, 0,
850 						&de_name, fstr);
851 			if (err)
852 				return err;
853 
854 			de_name = *fstr;
855 			fstr->len = save_len;
856 		}
857 
858 		if (!dir_emit(ctx, de_name.name, de_name.len,
859 					le32_to_cpu(de->ino), d_type))
860 			return 1;
861 
862 		bit_pos += GET_DENTRY_SLOTS(le16_to_cpu(de->name_len));
863 		ctx->pos = start_pos + bit_pos;
864 	}
865 	return 0;
866 }
867 
868 static int f2fs_readdir(struct file *file, struct dir_context *ctx)
869 {
870 	struct inode *inode = file_inode(file);
871 	unsigned long npages = dir_blocks(inode);
872 	struct f2fs_dentry_block *dentry_blk = NULL;
873 	struct page *dentry_page = NULL;
874 	struct file_ra_state *ra = &file->f_ra;
875 	unsigned int n = ((unsigned long)ctx->pos / NR_DENTRY_IN_BLOCK);
876 	struct f2fs_dentry_ptr d;
877 	struct fscrypt_str fstr = FSTR_INIT(NULL, 0);
878 	int err = 0;
879 
880 	if (f2fs_encrypted_inode(inode)) {
881 		err = fscrypt_get_encryption_info(inode);
882 		if (err && err != -ENOKEY)
883 			return err;
884 
885 		err = fscrypt_fname_alloc_buffer(inode, F2FS_NAME_LEN, &fstr);
886 		if (err < 0)
887 			return err;
888 	}
889 
890 	if (f2fs_has_inline_dentry(inode)) {
891 		err = f2fs_read_inline_dir(file, ctx, &fstr);
892 		goto out;
893 	}
894 
895 	/* readahead for multi pages of dir */
896 	if (npages - n > 1 && !ra_has_index(ra, n))
897 		page_cache_sync_readahead(inode->i_mapping, ra, file, n,
898 				min(npages - n, (pgoff_t)MAX_DIR_RA_PAGES));
899 
900 	for (; n < npages; n++) {
901 		dentry_page = get_lock_data_page(inode, n, false);
902 		if (IS_ERR(dentry_page)) {
903 			err = PTR_ERR(dentry_page);
904 			if (err == -ENOENT) {
905 				err = 0;
906 				continue;
907 			} else {
908 				goto out;
909 			}
910 		}
911 
912 		dentry_blk = kmap(dentry_page);
913 
914 		make_dentry_ptr(inode, &d, (void *)dentry_blk, 1);
915 
916 		err = f2fs_fill_dentries(ctx, &d,
917 				n * NR_DENTRY_IN_BLOCK, &fstr);
918 		if (err) {
919 			kunmap(dentry_page);
920 			f2fs_put_page(dentry_page, 1);
921 			break;
922 		}
923 
924 		ctx->pos = (n + 1) * NR_DENTRY_IN_BLOCK;
925 		kunmap(dentry_page);
926 		f2fs_put_page(dentry_page, 1);
927 	}
928 out:
929 	fscrypt_fname_free_buffer(&fstr);
930 	return err < 0 ? err : 0;
931 }
932 
933 static int f2fs_dir_open(struct inode *inode, struct file *filp)
934 {
935 	if (f2fs_encrypted_inode(inode))
936 		return fscrypt_get_encryption_info(inode) ? -EACCES : 0;
937 	return 0;
938 }
939 
940 const struct file_operations f2fs_dir_operations = {
941 	.llseek		= generic_file_llseek,
942 	.read		= generic_read_dir,
943 	.iterate_shared	= f2fs_readdir,
944 	.fsync		= f2fs_sync_file,
945 	.open		= f2fs_dir_open,
946 	.unlocked_ioctl	= f2fs_ioctl,
947 #ifdef CONFIG_COMPAT
948 	.compat_ioctl   = f2fs_compat_ioctl,
949 #endif
950 };
951