1 files changed, 940 insertions, 0 deletions

diff --git a/fs/f2fs/dir.c b/fs/f2fs/dir.c
new file mode 100644
index 000000000..2cd85ce3e
--- /dev/null
+++ b/fs/f2fs/dir.c
@@ -0,0 +1,940 @@
+/*
+ * fs/f2fs/dir.c
+ *
+ * Copyright (c) 2012 Samsung Electronics Co., Ltd.
+ *             http://www.samsung.com/
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/fs.h>
+#include <linux/f2fs_fs.h>
+#include <linux/sched/signal.h>
+#include "f2fs.h"
+#include "node.h"
+#include "acl.h"
+#include "xattr.h"
+#include <trace/events/f2fs.h>
+
+static unsigned long dir_blocks(struct inode *inode)
+{
+	return ((unsigned long long) (i_size_read(inode) + PAGE_SIZE - 1))
+							>> PAGE_SHIFT;
+}
+
+static unsigned int dir_buckets(unsigned int level, int dir_level)
+{
+	if (level + dir_level < MAX_DIR_HASH_DEPTH / 2)
+		return 1 << (level + dir_level);
+	else
+		return MAX_DIR_BUCKETS;
+}
+
+static unsigned int bucket_blocks(unsigned int level)
+{
+	if (level < MAX_DIR_HASH_DEPTH / 2)
+		return 2;
+	else
+		return 4;
+}
+
+static unsigned char f2fs_filetype_table[F2FS_FT_MAX] = {
+	[F2FS_FT_UNKNOWN]	= DT_UNKNOWN,
+	[F2FS_FT_REG_FILE]	= DT_REG,
+	[F2FS_FT_DIR]		= DT_DIR,
+	[F2FS_FT_CHRDEV]	= DT_CHR,
+	[F2FS_FT_BLKDEV]	= DT_BLK,
+	[F2FS_FT_FIFO]		= DT_FIFO,
+	[F2FS_FT_SOCK]		= DT_SOCK,
+	[F2FS_FT_SYMLINK]	= DT_LNK,
+};
+
+static unsigned char f2fs_type_by_mode[S_IFMT >> S_SHIFT] = {
+	[S_IFREG >> S_SHIFT]	= F2FS_FT_REG_FILE,
+	[S_IFDIR >> S_SHIFT]	= F2FS_FT_DIR,
+	[S_IFCHR >> S_SHIFT]	= F2FS_FT_CHRDEV,
+	[S_IFBLK >> S_SHIFT]	= F2FS_FT_BLKDEV,
+	[S_IFIFO >> S_SHIFT]	= F2FS_FT_FIFO,
+	[S_IFSOCK >> S_SHIFT]	= F2FS_FT_SOCK,
+	[S_IFLNK >> S_SHIFT]	= F2FS_FT_SYMLINK,
+};
+
+static void set_de_type(struct f2fs_dir_entry *de, umode_t mode)
+{
+	de->file_type = f2fs_type_by_mode[(mode & S_IFMT) >> S_SHIFT];
+}
+
+unsigned char f2fs_get_de_type(struct f2fs_dir_entry *de)
+{
+	if (de->file_type < F2FS_FT_MAX)
+		return f2fs_filetype_table[de->file_type];
+	return DT_UNKNOWN;
+}
+
+static unsigned long dir_block_index(unsigned int level,
+				int dir_level, unsigned int idx)
+{
+	unsigned long i;
+	unsigned long bidx = 0;
+
+	for (i = 0; i < level; i++)
+		bidx += dir_buckets(i, dir_level) * bucket_blocks(i);
+	bidx += idx * bucket_blocks(level);
+	return bidx;
+}
+
+static struct f2fs_dir_entry *find_in_block(struct page *dentry_page,
+				struct fscrypt_name *fname,
+				f2fs_hash_t namehash,
+				int *max_slots,
+				struct page **res_page)
+{
+	struct f2fs_dentry_block *dentry_blk;
+	struct f2fs_dir_entry *de;
+	struct f2fs_dentry_ptr d;
+
+	dentry_blk = (struct f2fs_dentry_block *)page_address(dentry_page);
+
+	make_dentry_ptr_block(NULL, &d, dentry_blk);
+	de = f2fs_find_target_dentry(fname, namehash, max_slots, &d);
+	if (de)
+		*res_page = dentry_page;
+
+	return de;
+}
+
+struct f2fs_dir_entry *f2fs_find_target_dentry(struct fscrypt_name *fname,
+			f2fs_hash_t namehash, int *max_slots,
+			struct f2fs_dentry_ptr *d)
+{
+	struct f2fs_dir_entry *de;
+	unsigned long bit_pos = 0;
+	int max_len = 0;
+
+	if (max_slots)
+		*max_slots = 0;
+	while (bit_pos < d->max) {
+		if (!test_bit_le(bit_pos, d->bitmap)) {
+			bit_pos++;
+			max_len++;
+			continue;
+		}
+
+		de = &d->dentry[bit_pos];
+
+		if (unlikely(!de->name_len)) {
+			bit_pos++;
+			continue;
+		}
+
+		if (de->hash_code == namehash &&
+		    fscrypt_match_name(fname, d->filename[bit_pos],
+				       le16_to_cpu(de->name_len)))
+			goto found;
+
+		if (max_slots && max_len > *max_slots)
+			*max_slots = max_len;
+		max_len = 0;
+
+		bit_pos += GET_DENTRY_SLOTS(le16_to_cpu(de->name_len));
+	}
+
+	de = NULL;
+found:
+	if (max_slots && max_len > *max_slots)
+		*max_slots = max_len;
+	return de;
+}
+
+static struct f2fs_dir_entry *find_in_level(struct inode *dir,
+					unsigned int level,
+					struct fscrypt_name *fname,
+					struct page **res_page)
+{
+	struct qstr name = FSTR_TO_QSTR(&fname->disk_name);
+	int s = GET_DENTRY_SLOTS(name.len);
+	unsigned int nbucket, nblock;
+	unsigned int bidx, end_block;
+	struct page *dentry_page;
+	struct f2fs_dir_entry *de = NULL;
+	bool room = false;
+	int max_slots;
+	f2fs_hash_t namehash = f2fs_dentry_hash(&name, fname);
+
+	nbucket = dir_buckets(level, F2FS_I(dir)->i_dir_level);
+	nblock = bucket_blocks(level);
+
+	bidx = dir_block_index(level, F2FS_I(dir)->i_dir_level,
+					le32_to_cpu(namehash) % nbucket);
+	end_block = bidx + nblock;
+
+	for (; bidx < end_block; bidx++) {
+		/* no need to allocate new dentry pages to all the indices */
+		dentry_page = f2fs_find_data_page(dir, bidx);
+		if (IS_ERR(dentry_page)) {
+			if (PTR_ERR(dentry_page) == -ENOENT) {
+				room = true;
+				continue;
+			} else {
+				*res_page = dentry_page;
+				break;
+			}
+		}
+
+		de = find_in_block(dentry_page, fname, namehash, &max_slots,
+								res_page);
+		if (de)
+			break;
+
+		if (max_slots >= s)
+			room = true;
+		f2fs_put_page(dentry_page, 0);
+	}
+
+	if (!de && room && F2FS_I(dir)->chash != namehash) {
+		F2FS_I(dir)->chash = namehash;
+		F2FS_I(dir)->clevel = level;
+	}
+
+	return de;
+}
+
+struct f2fs_dir_entry *__f2fs_find_entry(struct inode *dir,
+			struct fscrypt_name *fname, struct page **res_page)
+{
+	unsigned long npages = dir_blocks(dir);
+	struct f2fs_dir_entry *de = NULL;
+	unsigned int max_depth;
+	unsigned int level;
+
+	*res_page = NULL;
+
+	if (f2fs_has_inline_dentry(dir)) {
+		de = f2fs_find_in_inline_dir(dir, fname, res_page);
+		goto out;
+	}
+
+	if (npages == 0)
+		goto out;
+
+	max_depth = F2FS_I(dir)->i_current_depth;
+	if (unlikely(max_depth > MAX_DIR_HASH_DEPTH)) {
+		f2fs_msg(F2FS_I_SB(dir)->sb, KERN_WARNING,
+				"Corrupted max_depth of %lu: %u",
+				dir->i_ino, max_depth);
+		max_depth = MAX_DIR_HASH_DEPTH;
+		f2fs_i_depth_write(dir, max_depth);
+	}
+
+	for (level = 0; level < max_depth; level++) {
+		de = find_in_level(dir, level, fname, res_page);
+		if (de || IS_ERR(*res_page))
+			break;
+	}
+out:
+	/* This is to increase the speed of f2fs_create */
+	if (!de)
+		F2FS_I(dir)->task = current;
+	return de;
+}
+
+/*
+ * Find an entry in the specified directory with the wanted name.
+ * It returns the page where the entry was found (as a parameter - res_page),
+ * and the entry itself. Page is returned mapped and unlocked.
+ * Entry is guaranteed to be valid.
+ */
+struct f2fs_dir_entry *f2fs_find_entry(struct inode *dir,
+			const struct qstr *child, struct page **res_page)
+{
+	struct f2fs_dir_entry *de = NULL;
+	struct fscrypt_name fname;
+	int err;
+
+	err = fscrypt_setup_filename(dir, child, 1, &fname);
+	if (err) {
+		if (err == -ENOENT)
+			*res_page = NULL;
+		else
+			*res_page = ERR_PTR(err);
+		return NULL;
+	}
+
+	de = __f2fs_find_entry(dir, &fname, res_page);
+
+	fscrypt_free_filename(&fname);
+	return de;
+}
+
+struct f2fs_dir_entry *f2fs_parent_dir(struct inode *dir, struct page **p)
+{
+	struct qstr dotdot = QSTR_INIT("..", 2);
+
+	return f2fs_find_entry(dir, &dotdot, p);
+}
+
+ino_t f2fs_inode_by_name(struct inode *dir, const struct qstr *qstr,
+							struct page **page)
+{
+	ino_t res = 0;
+	struct f2fs_dir_entry *de;
+
+	de = f2fs_find_entry(dir, qstr, page);
+	if (de) {
+		res = le32_to_cpu(de->ino);
+		f2fs_put_page(*page, 0);
+	}
+
+	return res;
+}
+
+void f2fs_set_link(struct inode *dir, struct f2fs_dir_entry *de,
+		struct page *page, struct inode *inode)
+{
+	enum page_type type = f2fs_has_inline_dentry(dir) ? NODE : DATA;
+	lock_page(page);
+	f2fs_wait_on_page_writeback(page, type, true);
+	de->ino = cpu_to_le32(inode->i_ino);
+	set_de_type(de, inode->i_mode);
+	set_page_dirty(page);
+
+	dir->i_mtime = dir->i_ctime = current_time(dir);
+	f2fs_mark_inode_dirty_sync(dir, false);
+	f2fs_put_page(page, 1);
+}
+
+static void init_dent_inode(const struct qstr *name, struct page *ipage)
+{
+	struct f2fs_inode *ri;
+
+	f2fs_wait_on_page_writeback(ipage, NODE, true);
+
+	/* copy name info. to this inode page */
+	ri = F2FS_INODE(ipage);
+	ri->i_namelen = cpu_to_le32(name->len);
+	memcpy(ri->i_name, name->name, name->len);
+	set_page_dirty(ipage);
+}
+
+void f2fs_do_make_empty_dir(struct inode *inode, struct inode *parent,
+					struct f2fs_dentry_ptr *d)
+{
+	struct qstr dot = QSTR_INIT(".", 1);
+	struct qstr dotdot = QSTR_INIT("..", 2);
+
+	/* update dirent of "." */
+	f2fs_update_dentry(inode->i_ino, inode->i_mode, d, &dot, 0, 0);
+
+	/* update dirent of ".." */
+	f2fs_update_dentry(parent->i_ino, parent->i_mode, d, &dotdot, 0, 1);
+}
+
+static int make_empty_dir(struct inode *inode,
+		struct inode *parent, struct page *page)
+{
+	struct page *dentry_page;
+	struct f2fs_dentry_block *dentry_blk;
+	struct f2fs_dentry_ptr d;
+
+	if (f2fs_has_inline_dentry(inode))
+		return f2fs_make_empty_inline_dir(inode, parent, page);
+
+	dentry_page = f2fs_get_new_data_page(inode, page, 0, true);
+	if (IS_ERR(dentry_page))
+		return PTR_ERR(dentry_page);
+
+	dentry_blk = page_address(dentry_page);
+
+	make_dentry_ptr_block(NULL, &d, dentry_blk);
+	f2fs_do_make_empty_dir(inode, parent, &d);
+
+	set_page_dirty(dentry_page);
+	f2fs_put_page(dentry_page, 1);
+	return 0;
+}
+
+struct page *f2fs_init_inode_metadata(struct inode *inode, struct inode *dir,
+			const struct qstr *new_name, const struct qstr *orig_name,
+			struct page *dpage)
+{
+	struct page *page;
+	int dummy_encrypt = DUMMY_ENCRYPTION_ENABLED(F2FS_I_SB(dir));
+	int err;
+
+	if (is_inode_flag_set(inode, FI_NEW_INODE)) {
+		page = f2fs_new_inode_page(inode);
+		if (IS_ERR(page))
+			return page;
+
+		if (S_ISDIR(inode->i_mode)) {
+			/* in order to handle error case */
+			get_page(page);
+			err = make_empty_dir(inode, dir, page);
+			if (err) {
+				lock_page(page);
+				goto put_error;
+			}
+			put_page(page);
+		}
+
+		err = f2fs_init_acl(inode, dir, page, dpage);
+		if (err)
+			goto put_error;
+
+		err = f2fs_init_security(inode, dir, orig_name, page);
+		if (err)
+			goto put_error;
+
+		if ((f2fs_encrypted_inode(dir) || dummy_encrypt) &&
+					f2fs_may_encrypt(inode)) {
+			err = fscrypt_inherit_context(dir, inode, page, false);
+			if (err)
+				goto put_error;
+		}
+	} else {
+		page = f2fs_get_node_page(F2FS_I_SB(dir), inode->i_ino);
+		if (IS_ERR(page))
+			return page;
+	}
+
+	if (new_name) {
+		init_dent_inode(new_name, page);
+		if (f2fs_encrypted_inode(dir))
+			file_set_enc_name(inode);
+	}
+
+	/*
+	 * This file should be checkpointed during fsync.
+	 * We lost i_pino from now on.
+	 */
+	if (is_inode_flag_set(inode, FI_INC_LINK)) {
+		if (!S_ISDIR(inode->i_mode))
+			file_lost_pino(inode);
+		/*
+		 * If link the tmpfile to alias through linkat path,
+		 * we should remove this inode from orphan list.
+		 */
+		if (inode->i_nlink == 0)
+			f2fs_remove_orphan_inode(F2FS_I_SB(dir), inode->i_ino);
+		f2fs_i_links_write(inode, true);
+	}
+	return page;
+
+put_error:
+	clear_nlink(inode);
+	f2fs_update_inode(inode, page);
+	f2fs_put_page(page, 1);
+	return ERR_PTR(err);
+}
+
+void f2fs_update_parent_metadata(struct inode *dir, struct inode *inode,
+						unsigned int current_depth)
+{
+	if (inode && is_inode_flag_set(inode, FI_NEW_INODE)) {
+		if (S_ISDIR(inode->i_mode))
+			f2fs_i_links_write(dir, true);
+		clear_inode_flag(inode, FI_NEW_INODE);
+	}
+	dir->i_mtime = dir->i_ctime = current_time(dir);
+	f2fs_mark_inode_dirty_sync(dir, false);
+
+	if (F2FS_I(dir)->i_current_depth != current_depth)
+		f2fs_i_depth_write(dir, current_depth);
+
+	if (inode && is_inode_flag_set(inode, FI_INC_LINK))
+		clear_inode_flag(inode, FI_INC_LINK);
+}
+
+int f2fs_room_for_filename(const void *bitmap, int slots, int max_slots)
+{
+	int bit_start = 0;
+	int zero_start, zero_end;
+next:
+	zero_start = find_next_zero_bit_le(bitmap, max_slots, bit_start);
+	if (zero_start >= max_slots)
+		return max_slots;
+
+	zero_end = find_next_bit_le(bitmap, max_slots, zero_start);
+	if (zero_end - zero_start >= slots)
+		return zero_start;
+
+	bit_start = zero_end + 1;
+
+	if (zero_end + 1 >= max_slots)
+		return max_slots;
+	goto next;
+}
+
+void f2fs_update_dentry(nid_t ino, umode_t mode, struct f2fs_dentry_ptr *d,
+				const struct qstr *name, f2fs_hash_t name_hash,
+				unsigned int bit_pos)
+{
+	struct f2fs_dir_entry *de;
+	int slots = GET_DENTRY_SLOTS(name->len);
+	int i;
+
+	de = &d->dentry[bit_pos];
+	de->hash_code = name_hash;
+	de->name_len = cpu_to_le16(name->len);
+	memcpy(d->filename[bit_pos], name->name, name->len);
+	de->ino = cpu_to_le32(ino);
+	set_de_type(de, mode);
+	for (i = 0; i < slots; i++) {
+		__set_bit_le(bit_pos + i, (void *)d->bitmap);
+		/* avoid wrong garbage data for readdir */
+		if (i)
+			(de + i)->name_len = 0;
+	}
+}
+
+int f2fs_add_regular_entry(struct inode *dir, const struct qstr *new_name,
+				const struct qstr *orig_name,
+				struct inode *inode, nid_t ino, umode_t mode)
+{
+	unsigned int bit_pos;
+	unsigned int level;
+	unsigned int current_depth;
+	unsigned long bidx, block;
+	f2fs_hash_t dentry_hash;
+	unsigned int nbucket, nblock;
+	struct page *dentry_page = NULL;
+	struct f2fs_dentry_block *dentry_blk = NULL;
+	struct f2fs_dentry_ptr d;
+	struct page *page = NULL;
+	int slots, err = 0;
+
+	level = 0;
+	slots = GET_DENTRY_SLOTS(new_name->len);
+	dentry_hash = f2fs_dentry_hash(new_name, NULL);
+
+	current_depth = F2FS_I(dir)->i_current_depth;
+	if (F2FS_I(dir)->chash == dentry_hash) {
+		level = F2FS_I(dir)->clevel;
+		F2FS_I(dir)->chash = 0;
+	}
+
+start:
+	if (time_to_inject(F2FS_I_SB(dir), FAULT_DIR_DEPTH)) {
+		f2fs_show_injection_info(FAULT_DIR_DEPTH);
+		return -ENOSPC;
+	}
+
+	if (unlikely(current_depth == MAX_DIR_HASH_DEPTH))
+		return -ENOSPC;
+
+	/* Increase the depth, if required */
+	if (level == current_depth)
+		++current_depth;
+
+	nbucket = dir_buckets(level, F2FS_I(dir)->i_dir_level);
+	nblock = bucket_blocks(level);
+
+	bidx = dir_block_index(level, F2FS_I(dir)->i_dir_level,
+				(le32_to_cpu(dentry_hash) % nbucket));
+
+	for (block = bidx; block <= (bidx + nblock - 1); block++) {
+		dentry_page = f2fs_get_new_data_page(dir, NULL, block, true);
+		if (IS_ERR(dentry_page))
+			return PTR_ERR(dentry_page);
+
+		dentry_blk = page_address(dentry_page);
+		bit_pos = f2fs_room_for_filename(&dentry_blk->dentry_bitmap,
+						slots, NR_DENTRY_IN_BLOCK);
+		if (bit_pos < NR_DENTRY_IN_BLOCK)
+			goto add_dentry;
+
+		f2fs_put_page(dentry_page, 1);
+	}
+
+	/* Move to next level to find the empty slot for new dentry */
+	++level;
+	goto start;
+add_dentry:
+	f2fs_wait_on_page_writeback(dentry_page, DATA, true);
+
+	if (inode) {
+		down_write(&F2FS_I(inode)->i_sem);
+		page = f2fs_init_inode_metadata(inode, dir, new_name,
+						orig_name, NULL);
+		if (IS_ERR(page)) {
+			err = PTR_ERR(page);
+			goto fail;
+		}
+	}
+
+	make_dentry_ptr_block(NULL, &d, dentry_blk);
+	f2fs_update_dentry(ino, mode, &d, new_name, dentry_hash, bit_pos);
+
+	set_page_dirty(dentry_page);
+
+	if (inode) {
+		f2fs_i_pino_write(inode, dir->i_ino);
+
+		/* synchronize inode page's data from inode cache */
+		if (is_inode_flag_set(inode, FI_NEW_INODE))
+			f2fs_update_inode(inode, page);
+
+		f2fs_put_page(page, 1);
+	}
+
+	f2fs_update_parent_metadata(dir, inode, current_depth);
+fail:
+	if (inode)
+		up_write(&F2FS_I(inode)->i_sem);
+
+	f2fs_put_page(dentry_page, 1);
+
+	return err;
+}
+
+int f2fs_add_dentry(struct inode *dir, struct fscrypt_name *fname,
+				struct inode *inode, nid_t ino, umode_t mode)
+{
+	struct qstr new_name;
+	int err = -EAGAIN;
+
+	new_name.name = fname_name(fname);
+	new_name.len = fname_len(fname);
+
+	if (f2fs_has_inline_dentry(dir))
+		err = f2fs_add_inline_entry(dir, &new_name, fname->usr_fname,
+							inode, ino, mode);
+	if (err == -EAGAIN)
+		err = f2fs_add_regular_entry(dir, &new_name, fname->usr_fname,
+							inode, ino, mode);
+
+	f2fs_update_time(F2FS_I_SB(dir), REQ_TIME);
+	return err;
+}
+
+/*
+ * Caller should grab and release a rwsem by calling f2fs_lock_op() and
+ * f2fs_unlock_op().
+ */
+int f2fs_do_add_link(struct inode *dir, const struct qstr *name,
+				struct inode *inode, nid_t ino, umode_t mode)
+{
+	struct fscrypt_name fname;
+	struct page *page = NULL;
+	struct f2fs_dir_entry *de = NULL;
+	int err;
+
+	err = fscrypt_setup_filename(dir, name, 0, &fname);
+	if (err)
+		return err;
+
+	/*
+	 * An immature stakable filesystem shows a race condition between lookup
+	 * and create. If we have same task when doing lookup and create, it's
+	 * definitely fine as expected by VFS normally. Otherwise, let's just
+	 * verify on-disk dentry one more time, which guarantees filesystem
+	 * consistency more.
+	 */
+	if (current != F2FS_I(dir)->task) {
+		de = __f2fs_find_entry(dir, &fname, &page);
+		F2FS_I(dir)->task = NULL;
+	}
+	if (de) {
+		f2fs_put_page(page, 0);
+		err = -EEXIST;
+	} else if (IS_ERR(page)) {
+		err = PTR_ERR(page);
+	} else {
+		err = f2fs_add_dentry(dir, &fname, inode, ino, mode);
+	}
+	fscrypt_free_filename(&fname);
+	return err;
+}
+
+int f2fs_do_tmpfile(struct inode *inode, struct inode *dir)
+{
+	struct page *page;
+	int err = 0;
+
+	down_write(&F2FS_I(inode)->i_sem);
+	page = f2fs_init_inode_metadata(inode, dir, NULL, NULL, NULL);
+	if (IS_ERR(page)) {
+		err = PTR_ERR(page);
+		goto fail;
+	}
+	f2fs_put_page(page, 1);
+
+	clear_inode_flag(inode, FI_NEW_INODE);
+fail:
+	up_write(&F2FS_I(inode)->i_sem);
+	f2fs_update_time(F2FS_I_SB(inode), REQ_TIME);
+	return err;
+}
+
+void f2fs_drop_nlink(struct inode *dir, struct inode *inode)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(dir);
+
+	down_write(&F2FS_I(inode)->i_sem);
+
+	if (S_ISDIR(inode->i_mode))
+		f2fs_i_links_write(dir, false);
+	inode->i_ctime = current_time(inode);
+
+	f2fs_i_links_write(inode, false);
+	if (S_ISDIR(inode->i_mode)) {
+		f2fs_i_links_write(inode, false);
+		f2fs_i_size_write(inode, 0);
+	}
+	up_write(&F2FS_I(inode)->i_sem);
+
+	if (inode->i_nlink == 0)
+		f2fs_add_orphan_inode(inode);
+	else
+		f2fs_release_orphan_inode(sbi);
+}
+
+/*
+ * It only removes the dentry from the dentry page, corresponding name
+ * entry in name page does not need to be touched during deletion.
+ */
+void f2fs_delete_entry(struct f2fs_dir_entry *dentry, struct page *page,
+					struct inode *dir, struct inode *inode)
+{
+	struct	f2fs_dentry_block *dentry_blk;
+	unsigned int bit_pos;
+	int slots = GET_DENTRY_SLOTS(le16_to_cpu(dentry->name_len));
+	int i;
+
+	f2fs_update_time(F2FS_I_SB(dir), REQ_TIME);
+
+	if (F2FS_OPTION(F2FS_I_SB(dir)).fsync_mode == FSYNC_MODE_STRICT)
+		f2fs_add_ino_entry(F2FS_I_SB(dir), dir->i_ino, TRANS_DIR_INO);
+
+	if (f2fs_has_inline_dentry(dir))
+		return f2fs_delete_inline_entry(dentry, page, dir, inode);
+
+	lock_page(page);
+	f2fs_wait_on_page_writeback(page, DATA, true);
+
+	dentry_blk = page_address(page);
+	bit_pos = dentry - dentry_blk->dentry;
+	for (i = 0; i < slots; i++)
+		__clear_bit_le(bit_pos + i, &dentry_blk->dentry_bitmap);
+
+	/* Let's check and deallocate this dentry page */
+	bit_pos = find_next_bit_le(&dentry_blk->dentry_bitmap,
+			NR_DENTRY_IN_BLOCK,
+			0);
+	set_page_dirty(page);
+
+	dir->i_ctime = dir->i_mtime = current_time(dir);
+	f2fs_mark_inode_dirty_sync(dir, false);
+
+	if (inode)
+		f2fs_drop_nlink(dir, inode);
+
+	if (bit_pos == NR_DENTRY_IN_BLOCK &&
+		!f2fs_truncate_hole(dir, page->index, page->index + 1)) {
+		f2fs_clear_radix_tree_dirty_tag(page);
+		clear_page_dirty_for_io(page);
+		ClearPagePrivate(page);
+		ClearPageUptodate(page);
+		clear_cold_data(page);
+		inode_dec_dirty_pages(dir);
+		f2fs_remove_dirty_inode(dir);
+	}
+	f2fs_put_page(page, 1);
+}
+
+bool f2fs_empty_dir(struct inode *dir)
+{
+	unsigned long bidx;
+	struct page *dentry_page;
+	unsigned int bit_pos;
+	struct f2fs_dentry_block *dentry_blk;
+	unsigned long nblock = dir_blocks(dir);
+
+	if (f2fs_has_inline_dentry(dir))
+		return f2fs_empty_inline_dir(dir);
+
+	for (bidx = 0; bidx < nblock; bidx++) {
+		dentry_page = f2fs_get_lock_data_page(dir, bidx, false);
+		if (IS_ERR(dentry_page)) {
+			if (PTR_ERR(dentry_page) == -ENOENT)
+				continue;
+			else
+				return false;
+		}
+
+		dentry_blk = page_address(dentry_page);
+		if (bidx == 0)
+			bit_pos = 2;
+		else
+			bit_pos = 0;
+		bit_pos = find_next_bit_le(&dentry_blk->dentry_bitmap,
+						NR_DENTRY_IN_BLOCK,
+						bit_pos);
+
+		f2fs_put_page(dentry_page, 1);
+
+		if (bit_pos < NR_DENTRY_IN_BLOCK)
+			return false;
+	}
+	return true;
+}
+
+int f2fs_fill_dentries(struct dir_context *ctx, struct f2fs_dentry_ptr *d,
+			unsigned int start_pos, struct fscrypt_str *fstr)
+{
+	unsigned char d_type = DT_UNKNOWN;
+	unsigned int bit_pos;
+	struct f2fs_dir_entry *de = NULL;
+	struct fscrypt_str de_name = FSTR_INIT(NULL, 0);
+	struct f2fs_sb_info *sbi = F2FS_I_SB(d->inode);
+	int err = 0;
+
+	bit_pos = ((unsigned long)ctx->pos % d->max);
+
+	while (bit_pos < d->max) {
+		bit_pos = find_next_bit_le(d->bitmap, d->max, bit_pos);
+		if (bit_pos >= d->max)
+			break;
+
+		de = &d->dentry[bit_pos];
+		if (de->name_len == 0) {
+			bit_pos++;
+			ctx->pos = start_pos + bit_pos;
+			continue;
+		}
+
+		d_type = f2fs_get_de_type(de);
+
+		de_name.name = d->filename[bit_pos];
+		de_name.len = le16_to_cpu(de->name_len);
+
+		/* check memory boundary before moving forward */
+		bit_pos += GET_DENTRY_SLOTS(le16_to_cpu(de->name_len));
+		if (unlikely(bit_pos > d->max ||
+				le16_to_cpu(de->name_len) > F2FS_NAME_LEN)) {
+			f2fs_msg(sbi->sb, KERN_WARNING,
+				"%s: corrupted namelen=%d, run fsck to fix.",
+				__func__, le16_to_cpu(de->name_len));
+			set_sbi_flag(sbi, SBI_NEED_FSCK);
+			err = -EINVAL;
+			goto out;
+		}
+
+		if (f2fs_encrypted_inode(d->inode)) {
+			int save_len = fstr->len;
+
+			err = fscrypt_fname_disk_to_usr(d->inode,
+						(u32)de->hash_code, 0,
+						&de_name, fstr);
+			if (err)
+				return err;
+
+			de_name = *fstr;
+			fstr->len = save_len;
+		}
+
+		if (!dir_emit(ctx, de_name.name, de_name.len,
+					le32_to_cpu(de->ino), d_type))
+			return 1;
+
+		if (sbi->readdir_ra == 1)
+			f2fs_ra_node_page(sbi, le32_to_cpu(de->ino));
+
+		ctx->pos = start_pos + bit_pos;
+	}
+out:
+	return err;
+}
+
+static int f2fs_readdir(struct file *file, struct dir_context *ctx)
+{
+	struct inode *inode = file_inode(file);
+	unsigned long npages = dir_blocks(inode);
+	struct f2fs_dentry_block *dentry_blk = NULL;
+	struct page *dentry_page = NULL;
+	struct file_ra_state *ra = &file->f_ra;
+	loff_t start_pos = ctx->pos;
+	unsigned int n = ((unsigned long)ctx->pos / NR_DENTRY_IN_BLOCK);
+	struct f2fs_dentry_ptr d;
+	struct fscrypt_str fstr = FSTR_INIT(NULL, 0);
+	int err = 0;
+
+	if (f2fs_encrypted_inode(inode)) {
+		err = fscrypt_get_encryption_info(inode);
+		if (err && err != -ENOKEY)
+			goto out;
+
+		err = fscrypt_fname_alloc_buffer(inode, F2FS_NAME_LEN, &fstr);
+		if (err < 0)
+			goto out;
+	}
+
+	if (f2fs_has_inline_dentry(inode)) {
+		err = f2fs_read_inline_dir(file, ctx, &fstr);
+		goto out_free;
+	}
+
+	for (; n < npages; n++, ctx->pos = n * NR_DENTRY_IN_BLOCK) {
+
+		/* allow readdir() to be interrupted */
+		if (fatal_signal_pending(current)) {
+			err = -ERESTARTSYS;
+			goto out_free;
+		}
+		cond_resched();
+
+		/* readahead for multi pages of dir */
+		if (npages - n > 1 && !ra_has_index(ra, n))
+			page_cache_sync_readahead(inode->i_mapping, ra, file, n,
+				min(npages - n, (pgoff_t)MAX_DIR_RA_PAGES));
+
+		dentry_page = f2fs_get_lock_data_page(inode, n, false);
+		if (IS_ERR(dentry_page)) {
+			err = PTR_ERR(dentry_page);
+			if (err == -ENOENT) {
+				err = 0;
+				continue;
+			} else {
+				goto out_free;
+			}
+		}
+
+		dentry_blk = page_address(dentry_page);
+
+		make_dentry_ptr_block(inode, &d, dentry_blk);
+
+		err = f2fs_fill_dentries(ctx, &d,
+				n * NR_DENTRY_IN_BLOCK, &fstr);
+		if (err) {
+			f2fs_put_page(dentry_page, 1);
+			break;
+		}
+
+		f2fs_put_page(dentry_page, 1);
+	}
+out_free:
+	fscrypt_fname_free_buffer(&fstr);
+out:
+	trace_f2fs_readdir(inode, start_pos, ctx->pos, err);
+	return err < 0 ? err : 0;
+}
+
+static int f2fs_dir_open(struct inode *inode, struct file *filp)
+{
+	if (f2fs_encrypted_inode(inode))
+		return fscrypt_get_encryption_info(inode) ? -EACCES : 0;
+	return 0;
+}
+
+const struct file_operations f2fs_dir_operations = {
+	.llseek		= generic_file_llseek,
+	.read		= generic_read_dir,
+	.iterate_shared	= f2fs_readdir,
+	.fsync		= f2fs_sync_file,
+	.open		= f2fs_dir_open,
+	.unlocked_ioctl	= f2fs_ioctl,
+#ifdef CONFIG_COMPAT
+	.compat_ioctl   = f2fs_compat_ioctl,
+#endif
+};