xref: /openbmc/linux/fs/f2fs/dir.c (revision 9cfc5c90)
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 + 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 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 void 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 
67 static 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 
79 static struct f2fs_dir_entry *find_in_block(struct page *dentry_page,
80 				struct f2fs_filename *fname,
81 				f2fs_hash_t namehash,
82 				int *max_slots,
83 				struct page **res_page)
84 {
85 	struct f2fs_dentry_block *dentry_blk;
86 	struct f2fs_dir_entry *de;
87 	struct f2fs_dentry_ptr d;
88 
89 	dentry_blk = (struct f2fs_dentry_block *)kmap(dentry_page);
90 
91 	make_dentry_ptr(NULL, &d, (void *)dentry_blk, 1);
92 	de = find_target_dentry(fname, namehash, max_slots, &d);
93 	if (de)
94 		*res_page = dentry_page;
95 	else
96 		kunmap(dentry_page);
97 
98 	/*
99 	 * For the most part, it should be a bug when name_len is zero.
100 	 * We stop here for figuring out where the bugs has occurred.
101 	 */
102 	f2fs_bug_on(F2FS_P_SB(dentry_page), d.max < 0);
103 	return de;
104 }
105 
106 struct f2fs_dir_entry *find_target_dentry(struct f2fs_filename *fname,
107 			f2fs_hash_t namehash, int *max_slots,
108 			struct f2fs_dentry_ptr *d)
109 {
110 	struct f2fs_dir_entry *de;
111 	unsigned long bit_pos = 0;
112 	int max_len = 0;
113 	struct f2fs_str de_name = FSTR_INIT(NULL, 0);
114 	struct f2fs_str *name = &fname->disk_name;
115 
116 	if (max_slots)
117 		*max_slots = 0;
118 	while (bit_pos < d->max) {
119 		if (!test_bit_le(bit_pos, d->bitmap)) {
120 			bit_pos++;
121 			max_len++;
122 			continue;
123 		}
124 
125 		de = &d->dentry[bit_pos];
126 
127 		/* encrypted case */
128 		de_name.name = d->filename[bit_pos];
129 		de_name.len = le16_to_cpu(de->name_len);
130 
131 		/* show encrypted name */
132 		if (fname->hash) {
133 			if (de->hash_code == fname->hash)
134 				goto found;
135 		} else if (de_name.len == name->len &&
136 			de->hash_code == namehash &&
137 			!memcmp(de_name.name, name->name, name->len))
138 			goto found;
139 
140 		if (max_slots && max_len > *max_slots)
141 			*max_slots = max_len;
142 		max_len = 0;
143 
144 		/* remain bug on condition */
145 		if (unlikely(!de->name_len))
146 			d->max = -1;
147 
148 		bit_pos += GET_DENTRY_SLOTS(le16_to_cpu(de->name_len));
149 	}
150 
151 	de = NULL;
152 found:
153 	if (max_slots && max_len > *max_slots)
154 		*max_slots = max_len;
155 	return de;
156 }
157 
158 static struct f2fs_dir_entry *find_in_level(struct inode *dir,
159 					unsigned int level,
160 					struct f2fs_filename *fname,
161 					struct page **res_page)
162 {
163 	struct qstr name = FSTR_TO_QSTR(&fname->disk_name);
164 	int s = GET_DENTRY_SLOTS(name.len);
165 	unsigned int nbucket, nblock;
166 	unsigned int bidx, end_block;
167 	struct page *dentry_page;
168 	struct f2fs_dir_entry *de = NULL;
169 	bool room = false;
170 	int max_slots;
171 	f2fs_hash_t namehash;
172 
173 	namehash = f2fs_dentry_hash(&name);
174 
175 	f2fs_bug_on(F2FS_I_SB(dir), level > MAX_DIR_HASH_DEPTH);
176 
177 	nbucket = dir_buckets(level, F2FS_I(dir)->i_dir_level);
178 	nblock = bucket_blocks(level);
179 
180 	bidx = dir_block_index(level, F2FS_I(dir)->i_dir_level,
181 					le32_to_cpu(namehash) % nbucket);
182 	end_block = bidx + nblock;
183 
184 	for (; bidx < end_block; bidx++) {
185 		/* no need to allocate new dentry pages to all the indices */
186 		dentry_page = find_data_page(dir, bidx);
187 		if (IS_ERR(dentry_page)) {
188 			room = true;
189 			continue;
190 		}
191 
192 		de = find_in_block(dentry_page, fname, namehash, &max_slots,
193 								res_page);
194 		if (de)
195 			break;
196 
197 		if (max_slots >= s)
198 			room = true;
199 		f2fs_put_page(dentry_page, 0);
200 	}
201 
202 	if (!de && room && F2FS_I(dir)->chash != namehash) {
203 		F2FS_I(dir)->chash = namehash;
204 		F2FS_I(dir)->clevel = level;
205 	}
206 
207 	return de;
208 }
209 
210 /*
211  * Find an entry in the specified directory with the wanted name.
212  * It returns the page where the entry was found (as a parameter - res_page),
213  * and the entry itself. Page is returned mapped and unlocked.
214  * Entry is guaranteed to be valid.
215  */
216 struct f2fs_dir_entry *f2fs_find_entry(struct inode *dir,
217 			struct qstr *child, struct page **res_page)
218 {
219 	unsigned long npages = dir_blocks(dir);
220 	struct f2fs_dir_entry *de = NULL;
221 	unsigned int max_depth;
222 	unsigned int level;
223 	struct f2fs_filename fname;
224 	int err;
225 
226 	*res_page = NULL;
227 
228 	err = f2fs_fname_setup_filename(dir, child, 1, &fname);
229 	if (err)
230 		return NULL;
231 
232 	if (f2fs_has_inline_dentry(dir)) {
233 		de = find_in_inline_dir(dir, &fname, res_page);
234 		goto out;
235 	}
236 
237 	if (npages == 0)
238 		goto out;
239 
240 	max_depth = F2FS_I(dir)->i_current_depth;
241 
242 	for (level = 0; level < max_depth; level++) {
243 		de = find_in_level(dir, level, &fname, res_page);
244 		if (de)
245 			break;
246 	}
247 out:
248 	f2fs_fname_free_filename(&fname);
249 	return de;
250 }
251 
252 struct f2fs_dir_entry *f2fs_parent_dir(struct inode *dir, struct page **p)
253 {
254 	struct page *page;
255 	struct f2fs_dir_entry *de;
256 	struct f2fs_dentry_block *dentry_blk;
257 
258 	if (f2fs_has_inline_dentry(dir))
259 		return f2fs_parent_inline_dir(dir, p);
260 
261 	page = get_lock_data_page(dir, 0, false);
262 	if (IS_ERR(page))
263 		return NULL;
264 
265 	dentry_blk = kmap(page);
266 	de = &dentry_blk->dentry[1];
267 	*p = page;
268 	unlock_page(page);
269 	return de;
270 }
271 
272 ino_t f2fs_inode_by_name(struct inode *dir, struct qstr *qstr)
273 {
274 	ino_t res = 0;
275 	struct f2fs_dir_entry *de;
276 	struct page *page;
277 
278 	de = f2fs_find_entry(dir, qstr, &page);
279 	if (de) {
280 		res = le32_to_cpu(de->ino);
281 		f2fs_dentry_kunmap(dir, page);
282 		f2fs_put_page(page, 0);
283 	}
284 
285 	return res;
286 }
287 
288 void f2fs_set_link(struct inode *dir, struct f2fs_dir_entry *de,
289 		struct page *page, struct inode *inode)
290 {
291 	enum page_type type = f2fs_has_inline_dentry(dir) ? NODE : DATA;
292 	lock_page(page);
293 	f2fs_wait_on_page_writeback(page, type);
294 	de->ino = cpu_to_le32(inode->i_ino);
295 	set_de_type(de, inode->i_mode);
296 	f2fs_dentry_kunmap(dir, page);
297 	set_page_dirty(page);
298 	dir->i_mtime = dir->i_ctime = CURRENT_TIME;
299 	mark_inode_dirty(dir);
300 
301 	f2fs_put_page(page, 1);
302 }
303 
304 static void init_dent_inode(const struct qstr *name, struct page *ipage)
305 {
306 	struct f2fs_inode *ri;
307 
308 	f2fs_wait_on_page_writeback(ipage, NODE);
309 
310 	/* copy name info. to this inode page */
311 	ri = F2FS_INODE(ipage);
312 	ri->i_namelen = cpu_to_le32(name->len);
313 	memcpy(ri->i_name, name->name, name->len);
314 	set_page_dirty(ipage);
315 }
316 
317 int update_dent_inode(struct inode *inode, struct inode *to,
318 					const struct qstr *name)
319 {
320 	struct page *page;
321 
322 	if (file_enc_name(to))
323 		return 0;
324 
325 	page = get_node_page(F2FS_I_SB(inode), inode->i_ino);
326 	if (IS_ERR(page))
327 		return PTR_ERR(page);
328 
329 	init_dent_inode(name, page);
330 	f2fs_put_page(page, 1);
331 
332 	return 0;
333 }
334 
335 void do_make_empty_dir(struct inode *inode, struct inode *parent,
336 					struct f2fs_dentry_ptr *d)
337 {
338 	struct f2fs_dir_entry *de;
339 
340 	de = &d->dentry[0];
341 	de->name_len = cpu_to_le16(1);
342 	de->hash_code = 0;
343 	de->ino = cpu_to_le32(inode->i_ino);
344 	memcpy(d->filename[0], ".", 1);
345 	set_de_type(de, inode->i_mode);
346 
347 	de = &d->dentry[1];
348 	de->hash_code = 0;
349 	de->name_len = cpu_to_le16(2);
350 	de->ino = cpu_to_le32(parent->i_ino);
351 	memcpy(d->filename[1], "..", 2);
352 	set_de_type(de, parent->i_mode);
353 
354 	test_and_set_bit_le(0, (void *)d->bitmap);
355 	test_and_set_bit_le(1, (void *)d->bitmap);
356 }
357 
358 static int make_empty_dir(struct inode *inode,
359 		struct inode *parent, struct page *page)
360 {
361 	struct page *dentry_page;
362 	struct f2fs_dentry_block *dentry_blk;
363 	struct f2fs_dentry_ptr d;
364 
365 	if (f2fs_has_inline_dentry(inode))
366 		return make_empty_inline_dir(inode, parent, page);
367 
368 	dentry_page = get_new_data_page(inode, page, 0, true);
369 	if (IS_ERR(dentry_page))
370 		return PTR_ERR(dentry_page);
371 
372 	dentry_blk = kmap_atomic(dentry_page);
373 
374 	make_dentry_ptr(NULL, &d, (void *)dentry_blk, 1);
375 	do_make_empty_dir(inode, parent, &d);
376 
377 	kunmap_atomic(dentry_blk);
378 
379 	set_page_dirty(dentry_page);
380 	f2fs_put_page(dentry_page, 1);
381 	return 0;
382 }
383 
384 struct page *init_inode_metadata(struct inode *inode, struct inode *dir,
385 			const struct qstr *name, struct page *dpage)
386 {
387 	struct page *page;
388 	int err;
389 
390 	if (is_inode_flag_set(F2FS_I(inode), FI_NEW_INODE)) {
391 		page = new_inode_page(inode);
392 		if (IS_ERR(page))
393 			return page;
394 
395 		if (S_ISDIR(inode->i_mode)) {
396 			err = make_empty_dir(inode, dir, page);
397 			if (err)
398 				goto error;
399 		}
400 
401 		err = f2fs_init_acl(inode, dir, page, dpage);
402 		if (err)
403 			goto put_error;
404 
405 		err = f2fs_init_security(inode, dir, name, page);
406 		if (err)
407 			goto put_error;
408 
409 		if (f2fs_encrypted_inode(dir) && f2fs_may_encrypt(inode)) {
410 			err = f2fs_inherit_context(dir, inode, page);
411 			if (err)
412 				goto put_error;
413 		}
414 	} else {
415 		page = get_node_page(F2FS_I_SB(dir), inode->i_ino);
416 		if (IS_ERR(page))
417 			return page;
418 
419 		set_cold_node(inode, page);
420 	}
421 
422 	if (name)
423 		init_dent_inode(name, page);
424 
425 	/*
426 	 * This file should be checkpointed during fsync.
427 	 * We lost i_pino from now on.
428 	 */
429 	if (is_inode_flag_set(F2FS_I(inode), FI_INC_LINK)) {
430 		file_lost_pino(inode);
431 		/*
432 		 * If link the tmpfile to alias through linkat path,
433 		 * we should remove this inode from orphan list.
434 		 */
435 		if (inode->i_nlink == 0)
436 			remove_orphan_inode(F2FS_I_SB(dir), inode->i_ino);
437 		inc_nlink(inode);
438 	}
439 	return page;
440 
441 put_error:
442 	f2fs_put_page(page, 1);
443 error:
444 	/* once the failed inode becomes a bad inode, i_mode is S_IFREG */
445 	truncate_inode_pages(&inode->i_data, 0);
446 	truncate_blocks(inode, 0, false);
447 	remove_dirty_dir_inode(inode);
448 	remove_inode_page(inode);
449 	return ERR_PTR(err);
450 }
451 
452 void update_parent_metadata(struct inode *dir, struct inode *inode,
453 						unsigned int current_depth)
454 {
455 	if (inode && is_inode_flag_set(F2FS_I(inode), FI_NEW_INODE)) {
456 		if (S_ISDIR(inode->i_mode)) {
457 			inc_nlink(dir);
458 			set_inode_flag(F2FS_I(dir), FI_UPDATE_DIR);
459 		}
460 		clear_inode_flag(F2FS_I(inode), FI_NEW_INODE);
461 	}
462 	dir->i_mtime = dir->i_ctime = CURRENT_TIME;
463 	mark_inode_dirty(dir);
464 
465 	if (F2FS_I(dir)->i_current_depth != current_depth) {
466 		F2FS_I(dir)->i_current_depth = current_depth;
467 		set_inode_flag(F2FS_I(dir), FI_UPDATE_DIR);
468 	}
469 
470 	if (inode && is_inode_flag_set(F2FS_I(inode), FI_INC_LINK))
471 		clear_inode_flag(F2FS_I(inode), FI_INC_LINK);
472 }
473 
474 int room_for_filename(const void *bitmap, int slots, int max_slots)
475 {
476 	int bit_start = 0;
477 	int zero_start, zero_end;
478 next:
479 	zero_start = find_next_zero_bit_le(bitmap, max_slots, bit_start);
480 	if (zero_start >= max_slots)
481 		return max_slots;
482 
483 	zero_end = find_next_bit_le(bitmap, max_slots, zero_start);
484 	if (zero_end - zero_start >= slots)
485 		return zero_start;
486 
487 	bit_start = zero_end + 1;
488 
489 	if (zero_end + 1 >= max_slots)
490 		return max_slots;
491 	goto next;
492 }
493 
494 void f2fs_update_dentry(nid_t ino, umode_t mode, struct f2fs_dentry_ptr *d,
495 				const struct qstr *name, f2fs_hash_t name_hash,
496 				unsigned int bit_pos)
497 {
498 	struct f2fs_dir_entry *de;
499 	int slots = GET_DENTRY_SLOTS(name->len);
500 	int i;
501 
502 	de = &d->dentry[bit_pos];
503 	de->hash_code = name_hash;
504 	de->name_len = cpu_to_le16(name->len);
505 	memcpy(d->filename[bit_pos], name->name, name->len);
506 	de->ino = cpu_to_le32(ino);
507 	set_de_type(de, mode);
508 	for (i = 0; i < slots; i++)
509 		test_and_set_bit_le(bit_pos + i, (void *)d->bitmap);
510 }
511 
512 /*
513  * Caller should grab and release a rwsem by calling f2fs_lock_op() and
514  * f2fs_unlock_op().
515  */
516 int __f2fs_add_link(struct inode *dir, const struct qstr *name,
517 				struct inode *inode, nid_t ino, umode_t mode)
518 {
519 	unsigned int bit_pos;
520 	unsigned int level;
521 	unsigned int current_depth;
522 	unsigned long bidx, block;
523 	f2fs_hash_t dentry_hash;
524 	unsigned int nbucket, nblock;
525 	struct page *dentry_page = NULL;
526 	struct f2fs_dentry_block *dentry_blk = NULL;
527 	struct f2fs_dentry_ptr d;
528 	struct page *page = NULL;
529 	struct f2fs_filename fname;
530 	struct qstr new_name;
531 	int slots, err;
532 
533 	err = f2fs_fname_setup_filename(dir, name, 0, &fname);
534 	if (err)
535 		return err;
536 
537 	new_name.name = fname_name(&fname);
538 	new_name.len = fname_len(&fname);
539 
540 	if (f2fs_has_inline_dentry(dir)) {
541 		err = f2fs_add_inline_entry(dir, &new_name, inode, ino, mode);
542 		if (!err || err != -EAGAIN)
543 			goto out;
544 		else
545 			err = 0;
546 	}
547 
548 	level = 0;
549 	slots = GET_DENTRY_SLOTS(new_name.len);
550 	dentry_hash = f2fs_dentry_hash(&new_name);
551 
552 	current_depth = F2FS_I(dir)->i_current_depth;
553 	if (F2FS_I(dir)->chash == dentry_hash) {
554 		level = F2FS_I(dir)->clevel;
555 		F2FS_I(dir)->chash = 0;
556 	}
557 
558 start:
559 	if (unlikely(current_depth == MAX_DIR_HASH_DEPTH)) {
560 		err = -ENOSPC;
561 		goto out;
562 	}
563 
564 	/* Increase the depth, if required */
565 	if (level == current_depth)
566 		++current_depth;
567 
568 	nbucket = dir_buckets(level, F2FS_I(dir)->i_dir_level);
569 	nblock = bucket_blocks(level);
570 
571 	bidx = dir_block_index(level, F2FS_I(dir)->i_dir_level,
572 				(le32_to_cpu(dentry_hash) % nbucket));
573 
574 	for (block = bidx; block <= (bidx + nblock - 1); block++) {
575 		dentry_page = get_new_data_page(dir, NULL, block, true);
576 		if (IS_ERR(dentry_page)) {
577 			err = PTR_ERR(dentry_page);
578 			goto out;
579 		}
580 
581 		dentry_blk = kmap(dentry_page);
582 		bit_pos = room_for_filename(&dentry_blk->dentry_bitmap,
583 						slots, NR_DENTRY_IN_BLOCK);
584 		if (bit_pos < NR_DENTRY_IN_BLOCK)
585 			goto add_dentry;
586 
587 		kunmap(dentry_page);
588 		f2fs_put_page(dentry_page, 1);
589 	}
590 
591 	/* Move to next level to find the empty slot for new dentry */
592 	++level;
593 	goto start;
594 add_dentry:
595 	f2fs_wait_on_page_writeback(dentry_page, DATA);
596 
597 	if (inode) {
598 		down_write(&F2FS_I(inode)->i_sem);
599 		page = init_inode_metadata(inode, dir, &new_name, NULL);
600 		if (IS_ERR(page)) {
601 			err = PTR_ERR(page);
602 			goto fail;
603 		}
604 		if (f2fs_encrypted_inode(dir))
605 			file_set_enc_name(inode);
606 	}
607 
608 	make_dentry_ptr(NULL, &d, (void *)dentry_blk, 1);
609 	f2fs_update_dentry(ino, mode, &d, &new_name, dentry_hash, bit_pos);
610 
611 	set_page_dirty(dentry_page);
612 
613 	if (inode) {
614 		/* we don't need to mark_inode_dirty now */
615 		F2FS_I(inode)->i_pino = dir->i_ino;
616 		update_inode(inode, page);
617 		f2fs_put_page(page, 1);
618 	}
619 
620 	update_parent_metadata(dir, inode, current_depth);
621 fail:
622 	if (inode)
623 		up_write(&F2FS_I(inode)->i_sem);
624 
625 	if (is_inode_flag_set(F2FS_I(dir), FI_UPDATE_DIR)) {
626 		update_inode_page(dir);
627 		clear_inode_flag(F2FS_I(dir), FI_UPDATE_DIR);
628 	}
629 	kunmap(dentry_page);
630 	f2fs_put_page(dentry_page, 1);
631 out:
632 	f2fs_fname_free_filename(&fname);
633 	return err;
634 }
635 
636 int f2fs_do_tmpfile(struct inode *inode, struct inode *dir)
637 {
638 	struct page *page;
639 	int err = 0;
640 
641 	down_write(&F2FS_I(inode)->i_sem);
642 	page = init_inode_metadata(inode, dir, NULL, NULL);
643 	if (IS_ERR(page)) {
644 		err = PTR_ERR(page);
645 		goto fail;
646 	}
647 	/* we don't need to mark_inode_dirty now */
648 	update_inode(inode, page);
649 	f2fs_put_page(page, 1);
650 
651 	clear_inode_flag(F2FS_I(inode), FI_NEW_INODE);
652 fail:
653 	up_write(&F2FS_I(inode)->i_sem);
654 	return err;
655 }
656 
657 void f2fs_drop_nlink(struct inode *dir, struct inode *inode, struct page *page)
658 {
659 	struct f2fs_sb_info *sbi = F2FS_I_SB(dir);
660 
661 	down_write(&F2FS_I(inode)->i_sem);
662 
663 	if (S_ISDIR(inode->i_mode)) {
664 		drop_nlink(dir);
665 		if (page)
666 			update_inode(dir, page);
667 		else
668 			update_inode_page(dir);
669 	}
670 	inode->i_ctime = CURRENT_TIME;
671 
672 	drop_nlink(inode);
673 	if (S_ISDIR(inode->i_mode)) {
674 		drop_nlink(inode);
675 		i_size_write(inode, 0);
676 	}
677 	up_write(&F2FS_I(inode)->i_sem);
678 	update_inode_page(inode);
679 
680 	if (inode->i_nlink == 0)
681 		add_orphan_inode(sbi, inode->i_ino);
682 	else
683 		release_orphan_inode(sbi);
684 }
685 
686 /*
687  * It only removes the dentry from the dentry page, corresponding name
688  * entry in name page does not need to be touched during deletion.
689  */
690 void f2fs_delete_entry(struct f2fs_dir_entry *dentry, struct page *page,
691 					struct inode *dir, struct inode *inode)
692 {
693 	struct	f2fs_dentry_block *dentry_blk;
694 	unsigned int bit_pos;
695 	int slots = GET_DENTRY_SLOTS(le16_to_cpu(dentry->name_len));
696 	int i;
697 
698 	if (f2fs_has_inline_dentry(dir))
699 		return f2fs_delete_inline_entry(dentry, page, dir, inode);
700 
701 	lock_page(page);
702 	f2fs_wait_on_page_writeback(page, DATA);
703 
704 	dentry_blk = page_address(page);
705 	bit_pos = dentry - dentry_blk->dentry;
706 	for (i = 0; i < slots; i++)
707 		clear_bit_le(bit_pos + i, &dentry_blk->dentry_bitmap);
708 
709 	/* Let's check and deallocate this dentry page */
710 	bit_pos = find_next_bit_le(&dentry_blk->dentry_bitmap,
711 			NR_DENTRY_IN_BLOCK,
712 			0);
713 	kunmap(page); /* kunmap - pair of f2fs_find_entry */
714 	set_page_dirty(page);
715 
716 	dir->i_ctime = dir->i_mtime = CURRENT_TIME;
717 
718 	if (inode)
719 		f2fs_drop_nlink(dir, inode, NULL);
720 
721 	if (bit_pos == NR_DENTRY_IN_BLOCK &&
722 			!truncate_hole(dir, page->index, page->index + 1)) {
723 		clear_page_dirty_for_io(page);
724 		ClearPagePrivate(page);
725 		ClearPageUptodate(page);
726 		inode_dec_dirty_pages(dir);
727 	}
728 	f2fs_put_page(page, 1);
729 }
730 
731 bool f2fs_empty_dir(struct inode *dir)
732 {
733 	unsigned long bidx;
734 	struct page *dentry_page;
735 	unsigned int bit_pos;
736 	struct f2fs_dentry_block *dentry_blk;
737 	unsigned long nblock = dir_blocks(dir);
738 
739 	if (f2fs_has_inline_dentry(dir))
740 		return f2fs_empty_inline_dir(dir);
741 
742 	for (bidx = 0; bidx < nblock; bidx++) {
743 		dentry_page = get_lock_data_page(dir, bidx, false);
744 		if (IS_ERR(dentry_page)) {
745 			if (PTR_ERR(dentry_page) == -ENOENT)
746 				continue;
747 			else
748 				return false;
749 		}
750 
751 		dentry_blk = kmap_atomic(dentry_page);
752 		if (bidx == 0)
753 			bit_pos = 2;
754 		else
755 			bit_pos = 0;
756 		bit_pos = find_next_bit_le(&dentry_blk->dentry_bitmap,
757 						NR_DENTRY_IN_BLOCK,
758 						bit_pos);
759 		kunmap_atomic(dentry_blk);
760 
761 		f2fs_put_page(dentry_page, 1);
762 
763 		if (bit_pos < NR_DENTRY_IN_BLOCK)
764 			return false;
765 	}
766 	return true;
767 }
768 
769 bool f2fs_fill_dentries(struct dir_context *ctx, struct f2fs_dentry_ptr *d,
770 				unsigned int start_pos, struct f2fs_str *fstr)
771 {
772 	unsigned char d_type = DT_UNKNOWN;
773 	unsigned int bit_pos;
774 	struct f2fs_dir_entry *de = NULL;
775 	struct f2fs_str de_name = FSTR_INIT(NULL, 0);
776 
777 	bit_pos = ((unsigned long)ctx->pos % d->max);
778 
779 	while (bit_pos < d->max) {
780 		bit_pos = find_next_bit_le(d->bitmap, d->max, bit_pos);
781 		if (bit_pos >= d->max)
782 			break;
783 
784 		de = &d->dentry[bit_pos];
785 		if (de->file_type < F2FS_FT_MAX)
786 			d_type = f2fs_filetype_table[de->file_type];
787 		else
788 			d_type = DT_UNKNOWN;
789 
790 		de_name.name = d->filename[bit_pos];
791 		de_name.len = le16_to_cpu(de->name_len);
792 
793 		if (f2fs_encrypted_inode(d->inode)) {
794 			int save_len = fstr->len;
795 			int ret;
796 
797 			de_name.name = kmalloc(de_name.len, GFP_NOFS);
798 			if (!de_name.name)
799 				return false;
800 
801 			memcpy(de_name.name, d->filename[bit_pos], de_name.len);
802 
803 			ret = f2fs_fname_disk_to_usr(d->inode, &de->hash_code,
804 							&de_name, fstr);
805 			kfree(de_name.name);
806 			if (ret < 0)
807 				return true;
808 
809 			de_name = *fstr;
810 			fstr->len = save_len;
811 		}
812 
813 		if (!dir_emit(ctx, de_name.name, de_name.len,
814 					le32_to_cpu(de->ino), d_type))
815 			return true;
816 
817 		bit_pos += GET_DENTRY_SLOTS(le16_to_cpu(de->name_len));
818 		ctx->pos = start_pos + bit_pos;
819 	}
820 	return false;
821 }
822 
823 static int f2fs_readdir(struct file *file, struct dir_context *ctx)
824 {
825 	struct inode *inode = file_inode(file);
826 	unsigned long npages = dir_blocks(inode);
827 	struct f2fs_dentry_block *dentry_blk = NULL;
828 	struct page *dentry_page = NULL;
829 	struct file_ra_state *ra = &file->f_ra;
830 	unsigned int n = ((unsigned long)ctx->pos / NR_DENTRY_IN_BLOCK);
831 	struct f2fs_dentry_ptr d;
832 	struct f2fs_str fstr = FSTR_INIT(NULL, 0);
833 	int err = 0;
834 
835 	if (f2fs_encrypted_inode(inode)) {
836 		err = f2fs_get_encryption_info(inode);
837 		if (err)
838 			return err;
839 
840 		err = f2fs_fname_crypto_alloc_buffer(inode, F2FS_NAME_LEN,
841 								&fstr);
842 		if (err < 0)
843 			return err;
844 	}
845 
846 	if (f2fs_has_inline_dentry(inode)) {
847 		err = f2fs_read_inline_dir(file, ctx, &fstr);
848 		goto out;
849 	}
850 
851 	/* readahead for multi pages of dir */
852 	if (npages - n > 1 && !ra_has_index(ra, n))
853 		page_cache_sync_readahead(inode->i_mapping, ra, file, n,
854 				min(npages - n, (pgoff_t)MAX_DIR_RA_PAGES));
855 
856 	for (; n < npages; n++) {
857 		dentry_page = get_lock_data_page(inode, n, false);
858 		if (IS_ERR(dentry_page))
859 			continue;
860 
861 		dentry_blk = kmap(dentry_page);
862 
863 		make_dentry_ptr(inode, &d, (void *)dentry_blk, 1);
864 
865 		if (f2fs_fill_dentries(ctx, &d, n * NR_DENTRY_IN_BLOCK, &fstr))
866 			goto stop;
867 
868 		ctx->pos = (n + 1) * NR_DENTRY_IN_BLOCK;
869 		kunmap(dentry_page);
870 		f2fs_put_page(dentry_page, 1);
871 		dentry_page = NULL;
872 	}
873 stop:
874 	if (dentry_page && !IS_ERR(dentry_page)) {
875 		kunmap(dentry_page);
876 		f2fs_put_page(dentry_page, 1);
877 	}
878 out:
879 	f2fs_fname_crypto_free_buffer(&fstr);
880 	return err;
881 }
882 
883 const struct file_operations f2fs_dir_operations = {
884 	.llseek		= generic_file_llseek,
885 	.read		= generic_read_dir,
886 	.iterate	= f2fs_readdir,
887 	.fsync		= f2fs_sync_file,
888 	.unlocked_ioctl	= f2fs_ioctl,
889 #ifdef CONFIG_COMPAT
890 	.compat_ioctl   = f2fs_compat_ioctl,
891 #endif
892 };
893