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  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_SIZE - 1))
 21							>> PAGE_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 struct f2fs_dir_entry *find_in_block(struct page *dentry_page,
 80				struct fscrypt_name *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
106struct f2fs_dir_entry *find_target_dentry(struct fscrypt_name *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 fscrypt_str de_name = FSTR_INIT(NULL, 0);
114	struct fscrypt_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;
152found:
153	if (max_slots && max_len > *max_slots)
154		*max_slots = max_len;
155	return de;
156}
157
158static struct f2fs_dir_entry *find_in_level(struct inode *dir,
159					unsigned int level,
160					struct fscrypt_name *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	nbucket = dir_buckets(level, F2FS_I(dir)->i_dir_level);
176	nblock = bucket_blocks(level);
177
178	bidx = dir_block_index(level, F2FS_I(dir)->i_dir_level,
179					le32_to_cpu(namehash) % nbucket);
180	end_block = bidx + nblock;
181
182	for (; bidx < end_block; bidx++) {
183		/* no need to allocate new dentry pages to all the indices */
184		dentry_page = find_data_page(dir, bidx);
185		if (IS_ERR(dentry_page)) {
186			room = true;
187			continue;
188		}
189
190		de = find_in_block(dentry_page, fname, namehash, &max_slots,
191								res_page);
192		if (de)
193			break;
194
195		if (max_slots >= s)
196			room = true;
197		f2fs_put_page(dentry_page, 0);
198	}
199
200	if (!de && room && F2FS_I(dir)->chash != namehash) {
201		F2FS_I(dir)->chash = namehash;
202		F2FS_I(dir)->clevel = level;
203	}
204
205	return de;
206}
207
208/*
209 * Find an entry in the specified directory with the wanted name.
210 * It returns the page where the entry was found (as a parameter - res_page),
211 * and the entry itself. Page is returned mapped and unlocked.
212 * Entry is guaranteed to be valid.
213 */
214struct f2fs_dir_entry *f2fs_find_entry(struct inode *dir,
215			struct qstr *child, struct page **res_page)
216{
217	unsigned long npages = dir_blocks(dir);
218	struct f2fs_dir_entry *de = NULL;
219	unsigned int max_depth;
220	unsigned int level;
221	struct fscrypt_name fname;
222	int err;
223
224	*res_page = NULL;
225
226	err = fscrypt_setup_filename(dir, child, 1, &fname);
227	if (err)
228		return NULL;
229
230	if (f2fs_has_inline_dentry(dir)) {
231		de = find_in_inline_dir(dir, &fname, res_page);
232		goto out;
233	}
234
235	if (npages == 0)
236		goto out;
237
238	max_depth = F2FS_I(dir)->i_current_depth;
239	if (unlikely(max_depth > MAX_DIR_HASH_DEPTH)) {
240		f2fs_msg(F2FS_I_SB(dir)->sb, KERN_WARNING,
241				"Corrupted max_depth of %lu: %u",
242				dir->i_ino, max_depth);
243		max_depth = MAX_DIR_HASH_DEPTH;
244		F2FS_I(dir)->i_current_depth = max_depth;
245		mark_inode_dirty(dir);
246	}
247
248	for (level = 0; level < max_depth; level++) {
249		de = find_in_level(dir, level, &fname, res_page);
250		if (de)
251			break;
252	}
253out:
254	fscrypt_free_filename(&fname);
255	return de;
256}
257
258struct f2fs_dir_entry *f2fs_parent_dir(struct inode *dir, struct page **p)
259{
260	struct page *page;
261	struct f2fs_dir_entry *de;
262	struct f2fs_dentry_block *dentry_blk;
263
264	if (f2fs_has_inline_dentry(dir))
265		return f2fs_parent_inline_dir(dir, p);
266
267	page = get_lock_data_page(dir, 0, false);
268	if (IS_ERR(page))
269		return NULL;
270
271	dentry_blk = kmap(page);
272	de = &dentry_blk->dentry[1];
273	*p = page;
274	unlock_page(page);
275	return de;
276}
277
278ino_t f2fs_inode_by_name(struct inode *dir, struct qstr *qstr)
279{
280	ino_t res = 0;
281	struct f2fs_dir_entry *de;
282	struct page *page;
283
284	de = f2fs_find_entry(dir, qstr, &page);
285	if (de) {
286		res = le32_to_cpu(de->ino);
287		f2fs_dentry_kunmap(dir, page);
288		f2fs_put_page(page, 0);
289	}
290
291	return res;
292}
293
294void f2fs_set_link(struct inode *dir, struct f2fs_dir_entry *de,
295		struct page *page, struct inode *inode)
296{
297	enum page_type type = f2fs_has_inline_dentry(dir) ? NODE : DATA;
298	lock_page(page);
299	f2fs_wait_on_page_writeback(page, type, true);
300	de->ino = cpu_to_le32(inode->i_ino);
301	set_de_type(de, inode->i_mode);
302	f2fs_dentry_kunmap(dir, page);
303	set_page_dirty(page);
304	dir->i_mtime = dir->i_ctime = CURRENT_TIME;
305	mark_inode_dirty(dir);
306
307	f2fs_put_page(page, 1);
308}
309
310static void init_dent_inode(const struct qstr *name, struct page *ipage)
311{
312	struct f2fs_inode *ri;
313
314	f2fs_wait_on_page_writeback(ipage, NODE, true);
315
316	/* copy name info. to this inode page */
317	ri = F2FS_INODE(ipage);
318	ri->i_namelen = cpu_to_le32(name->len);
319	memcpy(ri->i_name, name->name, name->len);
320	set_page_dirty(ipage);
321}
322
323int update_dent_inode(struct inode *inode, struct inode *to,
324					const struct qstr *name)
325{
326	struct page *page;
327
328	if (file_enc_name(to))
329		return 0;
330
331	page = get_node_page(F2FS_I_SB(inode), inode->i_ino);
332	if (IS_ERR(page))
333		return PTR_ERR(page);
334
335	init_dent_inode(name, page);
336	f2fs_put_page(page, 1);
337
338	return 0;
339}
340
341void do_make_empty_dir(struct inode *inode, struct inode *parent,
342					struct f2fs_dentry_ptr *d)
343{
344	struct qstr dot = QSTR_INIT(".", 1);
345	struct qstr dotdot = QSTR_INIT("..", 2);
346
347	/* update dirent of "." */
348	f2fs_update_dentry(inode->i_ino, inode->i_mode, d, &dot, 0, 0);
349
350	/* update dirent of ".." */
351	f2fs_update_dentry(parent->i_ino, parent->i_mode, d, &dotdot, 0, 1);
352}
353
354static int make_empty_dir(struct inode *inode,
355		struct inode *parent, struct page *page)
356{
357	struct page *dentry_page;
358	struct f2fs_dentry_block *dentry_blk;
359	struct f2fs_dentry_ptr d;
360
361	if (f2fs_has_inline_dentry(inode))
362		return make_empty_inline_dir(inode, parent, page);
363
364	dentry_page = get_new_data_page(inode, page, 0, true);
365	if (IS_ERR(dentry_page))
366		return PTR_ERR(dentry_page);
367
368	dentry_blk = kmap_atomic(dentry_page);
369
370	make_dentry_ptr(NULL, &d, (void *)dentry_blk, 1);
371	do_make_empty_dir(inode, parent, &d);
372
373	kunmap_atomic(dentry_blk);
374
375	set_page_dirty(dentry_page);
376	f2fs_put_page(dentry_page, 1);
377	return 0;
378}
379
380struct page *init_inode_metadata(struct inode *inode, struct inode *dir,
381			const struct qstr *name, struct page *dpage)
382{
383	struct page *page;
384	int err;
385
386	if (is_inode_flag_set(F2FS_I(inode), FI_NEW_INODE)) {
387		page = new_inode_page(inode);
388		if (IS_ERR(page))
389			return page;
390
391		if (S_ISDIR(inode->i_mode)) {
392			err = make_empty_dir(inode, dir, page);
393			if (err)
394				goto error;
395		}
396
397		err = f2fs_init_acl(inode, dir, page, dpage);
398		if (err)
399			goto put_error;
400
401		err = f2fs_init_security(inode, dir, name, page);
402		if (err)
403			goto put_error;
404
405		if (f2fs_encrypted_inode(dir) && f2fs_may_encrypt(inode)) {
406			err = fscrypt_inherit_context(dir, inode, page, false);
407			if (err)
408				goto put_error;
409		}
410	} else {
411		page = get_node_page(F2FS_I_SB(dir), inode->i_ino);
412		if (IS_ERR(page))
413			return page;
414
415		set_cold_node(inode, page);
416	}
417
418	if (name)
419		init_dent_inode(name, page);
420
421	/*
422	 * This file should be checkpointed during fsync.
423	 * We lost i_pino from now on.
424	 */
425	if (is_inode_flag_set(F2FS_I(inode), FI_INC_LINK)) {
426		file_lost_pino(inode);
427		/*
428		 * If link the tmpfile to alias through linkat path,
429		 * we should remove this inode from orphan list.
430		 */
431		if (inode->i_nlink == 0)
432			remove_orphan_inode(F2FS_I_SB(dir), inode->i_ino);
433		inc_nlink(inode);
434	}
435	return page;
436
437put_error:
438	f2fs_put_page(page, 1);
439error:
440	/* once the failed inode becomes a bad inode, i_mode is S_IFREG */
441	truncate_inode_pages(&inode->i_data, 0);
442	truncate_blocks(inode, 0, false);
443	remove_dirty_inode(inode);
444	remove_inode_page(inode);
445	return ERR_PTR(err);
446}
447
448void update_parent_metadata(struct inode *dir, struct inode *inode,
449						unsigned int current_depth)
450{
451	if (inode && is_inode_flag_set(F2FS_I(inode), FI_NEW_INODE)) {
452		if (S_ISDIR(inode->i_mode)) {
453			inc_nlink(dir);
454			set_inode_flag(F2FS_I(dir), FI_UPDATE_DIR);
455		}
456		clear_inode_flag(F2FS_I(inode), FI_NEW_INODE);
457	}
458	dir->i_mtime = dir->i_ctime = CURRENT_TIME;
459	mark_inode_dirty(dir);
460
461	if (F2FS_I(dir)->i_current_depth != current_depth) {
462		F2FS_I(dir)->i_current_depth = current_depth;
463		set_inode_flag(F2FS_I(dir), FI_UPDATE_DIR);
464	}
465
466	if (inode && is_inode_flag_set(F2FS_I(inode), FI_INC_LINK))
467		clear_inode_flag(F2FS_I(inode), FI_INC_LINK);
468}
469
470int room_for_filename(const void *bitmap, int slots, int max_slots)
471{
472	int bit_start = 0;
473	int zero_start, zero_end;
474next:
475	zero_start = find_next_zero_bit_le(bitmap, max_slots, bit_start);
476	if (zero_start >= max_slots)
477		return max_slots;
478
479	zero_end = find_next_bit_le(bitmap, max_slots, zero_start);
480	if (zero_end - zero_start >= slots)
481		return zero_start;
482
483	bit_start = zero_end + 1;
484
485	if (zero_end + 1 >= max_slots)
486		return max_slots;
487	goto next;
488}
489
490void f2fs_update_dentry(nid_t ino, umode_t mode, struct f2fs_dentry_ptr *d,
491				const struct qstr *name, f2fs_hash_t name_hash,
492				unsigned int bit_pos)
493{
494	struct f2fs_dir_entry *de;
495	int slots = GET_DENTRY_SLOTS(name->len);
496	int i;
497
498	de = &d->dentry[bit_pos];
499	de->hash_code = name_hash;
500	de->name_len = cpu_to_le16(name->len);
501	memcpy(d->filename[bit_pos], name->name, name->len);
502	de->ino = cpu_to_le32(ino);
503	set_de_type(de, mode);
504	for (i = 0; i < slots; i++) {
505		test_and_set_bit_le(bit_pos + i, (void *)d->bitmap);
506		/* avoid wrong garbage data for readdir */
507		if (i)
508			(de + i)->name_len = 0;
509	}
510}
511
512/*
513 * Caller should grab and release a rwsem by calling f2fs_lock_op() and
514 * f2fs_unlock_op().
515 */
516int __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 fscrypt_name fname;
530	struct qstr new_name;
531	int slots, err;
532
533	err = fscrypt_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
558start:
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;
594add_dentry:
595	f2fs_wait_on_page_writeback(dentry_page, DATA, true);
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);
621fail:
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);
631out:
632	fscrypt_free_filename(&fname);
633	f2fs_update_time(F2FS_I_SB(dir), REQ_TIME);
634	return err;
635}
636
637int f2fs_do_tmpfile(struct inode *inode, struct inode *dir)
638{
639	struct page *page;
640	int err = 0;
641
642	down_write(&F2FS_I(inode)->i_sem);
643	page = init_inode_metadata(inode, dir, NULL, NULL);
644	if (IS_ERR(page)) {
645		err = PTR_ERR(page);
646		goto fail;
647	}
648	/* we don't need to mark_inode_dirty now */
649	update_inode(inode, page);
650	f2fs_put_page(page, 1);
651
652	clear_inode_flag(F2FS_I(inode), FI_NEW_INODE);
653fail:
654	up_write(&F2FS_I(inode)->i_sem);
655	f2fs_update_time(F2FS_I_SB(inode), REQ_TIME);
656	return err;
657}
658
659void f2fs_drop_nlink(struct inode *dir, struct inode *inode, struct page *page)
660{
661	struct f2fs_sb_info *sbi = F2FS_I_SB(dir);
662
663	down_write(&F2FS_I(inode)->i_sem);
664
665	if (S_ISDIR(inode->i_mode)) {
666		drop_nlink(dir);
667		if (page)
668			update_inode(dir, page);
669		else
670			update_inode_page(dir);
671	}
672	inode->i_ctime = CURRENT_TIME;
673
674	drop_nlink(inode);
675	if (S_ISDIR(inode->i_mode)) {
676		drop_nlink(inode);
677		i_size_write(inode, 0);
678	}
679	up_write(&F2FS_I(inode)->i_sem);
680	update_inode_page(inode);
681
682	if (inode->i_nlink == 0)
683		add_orphan_inode(sbi, inode->i_ino);
684	else
685		release_orphan_inode(sbi);
686}
687
688/*
689 * It only removes the dentry from the dentry page, corresponding name
690 * entry in name page does not need to be touched during deletion.
691 */
692void f2fs_delete_entry(struct f2fs_dir_entry *dentry, struct page *page,
693					struct inode *dir, struct inode *inode)
694{
695	struct	f2fs_dentry_block *dentry_blk;
696	unsigned int bit_pos;
697	int slots = GET_DENTRY_SLOTS(le16_to_cpu(dentry->name_len));
698	int i;
699
700	f2fs_update_time(F2FS_I_SB(dir), REQ_TIME);
701
702	if (f2fs_has_inline_dentry(dir))
703		return f2fs_delete_inline_entry(dentry, page, dir, inode);
704
705	lock_page(page);
706	f2fs_wait_on_page_writeback(page, DATA, true);
707
708	dentry_blk = page_address(page);
709	bit_pos = dentry - dentry_blk->dentry;
710	for (i = 0; i < slots; i++)
711		clear_bit_le(bit_pos + i, &dentry_blk->dentry_bitmap);
712
713	/* Let's check and deallocate this dentry page */
714	bit_pos = find_next_bit_le(&dentry_blk->dentry_bitmap,
715			NR_DENTRY_IN_BLOCK,
716			0);
717	kunmap(page); /* kunmap - pair of f2fs_find_entry */
718	set_page_dirty(page);
719
720	dir->i_ctime = dir->i_mtime = CURRENT_TIME;
721
722	if (inode)
723		f2fs_drop_nlink(dir, inode, NULL);
724
725	if (bit_pos == NR_DENTRY_IN_BLOCK &&
726			!truncate_hole(dir, page->index, page->index + 1)) {
727		clear_page_dirty_for_io(page);
728		ClearPagePrivate(page);
729		ClearPageUptodate(page);
730		inode_dec_dirty_pages(dir);
731	}
732	f2fs_put_page(page, 1);
733}
734
735bool f2fs_empty_dir(struct inode *dir)
736{
737	unsigned long bidx;
738	struct page *dentry_page;
739	unsigned int bit_pos;
740	struct f2fs_dentry_block *dentry_blk;
741	unsigned long nblock = dir_blocks(dir);
742
743	if (f2fs_has_inline_dentry(dir))
744		return f2fs_empty_inline_dir(dir);
745
746	for (bidx = 0; bidx < nblock; bidx++) {
747		dentry_page = get_lock_data_page(dir, bidx, false);
748		if (IS_ERR(dentry_page)) {
749			if (PTR_ERR(dentry_page) == -ENOENT)
750				continue;
751			else
752				return false;
753		}
754
755		dentry_blk = kmap_atomic(dentry_page);
756		if (bidx == 0)
757			bit_pos = 2;
758		else
759			bit_pos = 0;
760		bit_pos = find_next_bit_le(&dentry_blk->dentry_bitmap,
761						NR_DENTRY_IN_BLOCK,
762						bit_pos);
763		kunmap_atomic(dentry_blk);
764
765		f2fs_put_page(dentry_page, 1);
766
767		if (bit_pos < NR_DENTRY_IN_BLOCK)
768			return false;
769	}
770	return true;
771}
772
773bool f2fs_fill_dentries(struct dir_context *ctx, struct f2fs_dentry_ptr *d,
774			unsigned int start_pos, struct fscrypt_str *fstr)
775{
776	unsigned char d_type = DT_UNKNOWN;
777	unsigned int bit_pos;
778	struct f2fs_dir_entry *de = NULL;
779	struct fscrypt_str de_name = FSTR_INIT(NULL, 0);
780
781	bit_pos = ((unsigned long)ctx->pos % d->max);
782
783	while (bit_pos < d->max) {
784		bit_pos = find_next_bit_le(d->bitmap, d->max, bit_pos);
785		if (bit_pos >= d->max)
786			break;
787
788		de = &d->dentry[bit_pos];
789		if (de->name_len == 0) {
790			bit_pos++;
791			ctx->pos = start_pos + bit_pos;
792			continue;
793		}
794
795		if (de->file_type < F2FS_FT_MAX)
796			d_type = f2fs_filetype_table[de->file_type];
797		else
798			d_type = DT_UNKNOWN;
799
800		de_name.name = d->filename[bit_pos];
801		de_name.len = le16_to_cpu(de->name_len);
802
803		if (f2fs_encrypted_inode(d->inode)) {
804			int save_len = fstr->len;
805			int ret;
806
807			de_name.name = kmalloc(de_name.len, GFP_NOFS);
808			if (!de_name.name)
809				return false;
810
811			memcpy(de_name.name, d->filename[bit_pos], de_name.len);
812
813			ret = fscrypt_fname_disk_to_usr(d->inode,
814						(u32)de->hash_code, 0,
815						&de_name, fstr);
816			kfree(de_name.name);
817			if (ret < 0)
818				return true;
819
820			de_name = *fstr;
821			fstr->len = save_len;
822		}
823
824		if (!dir_emit(ctx, de_name.name, de_name.len,
825					le32_to_cpu(de->ino), d_type))
826			return true;
827
828		bit_pos += GET_DENTRY_SLOTS(le16_to_cpu(de->name_len));
829		ctx->pos = start_pos + bit_pos;
830	}
831	return false;
832}
833
834static int f2fs_readdir(struct file *file, struct dir_context *ctx)
835{
836	struct inode *inode = file_inode(file);
837	unsigned long npages = dir_blocks(inode);
838	struct f2fs_dentry_block *dentry_blk = NULL;
839	struct page *dentry_page = NULL;
840	struct file_ra_state *ra = &file->f_ra;
841	unsigned int n = ((unsigned long)ctx->pos / NR_DENTRY_IN_BLOCK);
842	struct f2fs_dentry_ptr d;
843	struct fscrypt_str fstr = FSTR_INIT(NULL, 0);
844	int err = 0;
845
846	if (f2fs_encrypted_inode(inode)) {
847		err = fscrypt_get_encryption_info(inode);
848		if (err && err != -ENOKEY)
849			return err;
850
851		err = fscrypt_fname_alloc_buffer(inode, F2FS_NAME_LEN, &fstr);
852		if (err < 0)
853			return err;
854	}
855
856	if (f2fs_has_inline_dentry(inode)) {
857		err = f2fs_read_inline_dir(file, ctx, &fstr);
858		goto out;
859	}
860
861	/* readahead for multi pages of dir */
862	if (npages - n > 1 && !ra_has_index(ra, n))
863		page_cache_sync_readahead(inode->i_mapping, ra, file, n,
864				min(npages - n, (pgoff_t)MAX_DIR_RA_PAGES));
865
866	for (; n < npages; n++) {
867		dentry_page = get_lock_data_page(inode, n, false);
868		if (IS_ERR(dentry_page)) {
869			err = PTR_ERR(dentry_page);
870			if (err == -ENOENT)
871				continue;
872			else
873				goto out;
874		}
875
876		dentry_blk = kmap(dentry_page);
877
878		make_dentry_ptr(inode, &d, (void *)dentry_blk, 1);
879
880		if (f2fs_fill_dentries(ctx, &d, n * NR_DENTRY_IN_BLOCK, &fstr)) {
881			kunmap(dentry_page);
882			f2fs_put_page(dentry_page, 1);
883			break;
884		}
885
886		ctx->pos = (n + 1) * NR_DENTRY_IN_BLOCK;
887		kunmap(dentry_page);
888		f2fs_put_page(dentry_page, 1);
889	}
890out:
891	fscrypt_fname_free_buffer(&fstr);
892	return err;
893}
894
895static int f2fs_dir_open(struct inode *inode, struct file *filp)
896{
897	if (f2fs_encrypted_inode(inode))
898		return fscrypt_get_encryption_info(inode) ? -EACCES : 0;
899	return 0;
900}
901
902const struct file_operations f2fs_dir_operations = {
903	.llseek		= generic_file_llseek,
904	.read		= generic_read_dir,
905	.iterate	= f2fs_readdir,
906	.fsync		= f2fs_sync_file,
907	.open		= f2fs_dir_open,
908	.unlocked_ioctl	= f2fs_ioctl,
909#ifdef CONFIG_COMPAT
910	.compat_ioctl   = f2fs_compat_ioctl,
911#endif
912};