[GitHub/exynos8895/android_kernel_samsung_universal8895.git] / fs / f2fs / dir.c

/*
 * 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 "f2fs.h"
#include "node.h"
#include "acl.h"
#include "xattr.h"

static unsigned long dir_blocks(struct inode *inode)
{
	return ((unsigned long long) (i_size_read(inode) + PAGE_CACHE_SIZE - 1))
							>> PAGE_CACHE_SHIFT;
}

static unsigned int dir_buckets(unsigned int level, int dir_level)
{
	if (level < MAX_DIR_HASH_DEPTH / 2)
		return 1 << (level + dir_level);
	else
		return 1 << ((MAX_DIR_HASH_DEPTH / 2 + dir_level) - 1);
}

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,
};

#define S_SHIFT 12
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, struct inode *inode)
{
	umode_t mode = inode->i_mode;
	de->file_type = f2fs_type_by_mode[(mode & S_IFMT) >> S_SHIFT];
}

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 bool early_match_name(const char *name, size_t namelen,
			f2fs_hash_t namehash, struct f2fs_dir_entry *de)
{
	if (le16_to_cpu(de->name_len) != namelen)
		return false;

	if (de->hash_code != namehash)
		return false;

	return true;
}

static struct f2fs_dir_entry *find_in_block(struct page *dentry_page,
			const char *name, size_t namelen, int *max_slots,
			f2fs_hash_t namehash, struct page **res_page)
{
	struct f2fs_dir_entry *de;
	unsigned long bit_pos = 0;
	struct f2fs_dentry_block *dentry_blk = kmap(dentry_page);
	const void *dentry_bits = &dentry_blk->dentry_bitmap;
	int max_len = 0;

	while (bit_pos < NR_DENTRY_IN_BLOCK) {
		if (!test_bit_le(bit_pos, dentry_bits)) {
			if (bit_pos == 0)
				max_len = 1;
			else if (!test_bit_le(bit_pos - 1, dentry_bits))
				max_len++;
			bit_pos++;
			continue;
		}
		de = &dentry_blk->dentry[bit_pos];
		if (early_match_name(name, namelen, namehash, de)) {
			if (!memcmp(dentry_blk->filename[bit_pos],
							name, namelen)) {
				*res_page = dentry_page;
				goto found;
			}
		}
		if (max_len > *max_slots) {
			*max_slots = max_len;
			max_len = 0;
		}
		bit_pos += GET_DENTRY_SLOTS(le16_to_cpu(de->name_len));
	}

	de = NULL;
	kunmap(dentry_page);
found:
	if (max_len > *max_slots)
		*max_slots = max_len;
	return de;
}

static struct f2fs_dir_entry *find_in_level(struct inode *dir,
		unsigned int level, const char *name, size_t namelen,
			f2fs_hash_t namehash, struct page **res_page)
{
	int s = GET_DENTRY_SLOTS(namelen);
	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 = 0;

	f2fs_bug_on(level > MAX_DIR_HASH_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(namehash) % nbucket);
	end_block = bidx + nblock;

	for (; bidx < end_block; bidx++) {
		/* no need to allocate new dentry pages to all the indices */
		dentry_page = find_data_page(dir, bidx, true);
		if (IS_ERR(dentry_page)) {
			room = true;
			continue;
		}

		de = find_in_block(dentry_page, name, namelen,
					&max_slots, namehash, 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;
}

/*
 * 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,
			struct qstr *child, struct page **res_page)
{
	const char *name = child->name;
	size_t namelen = child->len;
	unsigned long npages = dir_blocks(dir);
	struct f2fs_dir_entry *de = NULL;
	f2fs_hash_t name_hash;
	unsigned int max_depth;
	unsigned int level;

	if (npages == 0)
		return NULL;

	*res_page = NULL;

	name_hash = f2fs_dentry_hash(name, namelen);
	max_depth = F2FS_I(dir)->i_current_depth;

	for (level = 0; level < max_depth; level++) {
		de = find_in_level(dir, level, name,
				namelen, name_hash, res_page);
		if (de)
			break;
	}
	if (!de && F2FS_I(dir)->chash != name_hash) {
		F2FS_I(dir)->chash = name_hash;
		F2FS_I(dir)->clevel = level - 1;
	}
	return de;
}

struct f2fs_dir_entry *f2fs_parent_dir(struct inode *dir, struct page **p)
{
	struct page *page;
	struct f2fs_dir_entry *de;
	struct f2fs_dentry_block *dentry_blk;

	page = get_lock_data_page(dir, 0);
	if (IS_ERR(page))
		return NULL;

	dentry_blk = kmap(page);
	de = &dentry_blk->dentry[1];
	*p = page;
	unlock_page(page);
	return de;
}

ino_t f2fs_inode_by_name(struct inode *dir, struct qstr *qstr)
{
	ino_t res = 0;
	struct f2fs_dir_entry *de;
	struct page *page;

	de = f2fs_find_entry(dir, qstr, &page);
	if (de) {
		res = le32_to_cpu(de->ino);
		kunmap(page);
		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)
{
	lock_page(page);
	f2fs_wait_on_page_writeback(page, DATA);
	de->ino = cpu_to_le32(inode->i_ino);
	set_de_type(de, inode);
	kunmap(page);
	set_page_dirty(page);
	dir->i_mtime = dir->i_ctime = CURRENT_TIME;
	mark_inode_dirty(dir);

	f2fs_put_page(page, 1);
}

static void init_dent_inode(const struct qstr *name, struct page *ipage)
{
	struct f2fs_inode *ri;

	/* 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);
}

int update_dent_inode(struct inode *inode, const struct qstr *name)
{
	struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
	struct page *page;

	page = get_node_page(sbi, inode->i_ino);
	if (IS_ERR(page))
		return PTR_ERR(page);

	init_dent_inode(name, page);
	f2fs_put_page(page, 1);

	return 0;
}

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_dir_entry *de;
	void *kaddr;

	dentry_page = get_new_data_page(inode, page, 0, true);
	if (IS_ERR(dentry_page))
		return PTR_ERR(dentry_page);

	kaddr = kmap_atomic(dentry_page);
	dentry_blk = (struct f2fs_dentry_block *)kaddr;

	de = &dentry_blk->dentry[0];
	de->name_len = cpu_to_le16(1);
	de->hash_code = 0;
	de->ino = cpu_to_le32(inode->i_ino);
	memcpy(dentry_blk->filename[0], ".", 1);
	set_de_type(de, inode);

	de = &dentry_blk->dentry[1];
	de->hash_code = 0;
	de->name_len = cpu_to_le16(2);
	de->ino = cpu_to_le32(parent->i_ino);
	memcpy(dentry_blk->filename[1], "..", 2);
	set_de_type(de, inode);

	test_and_set_bit_le(0, &dentry_blk->dentry_bitmap);
	test_and_set_bit_le(1, &dentry_blk->dentry_bitmap);
	kunmap_atomic(kaddr);

	set_page_dirty(dentry_page);
	f2fs_put_page(dentry_page, 1);
	return 0;
}

static struct page *init_inode_metadata(struct inode *inode,
		struct inode *dir, const struct qstr *name)
{
	struct page *page;
	int err;

	if (is_inode_flag_set(F2FS_I(inode), FI_NEW_INODE)) {
		page = new_inode_page(inode, name);
		if (IS_ERR(page))
			return page;

		if (S_ISDIR(inode->i_mode)) {
			err = make_empty_dir(inode, dir, page);
			if (err)
				goto error;
		}

		err = f2fs_init_acl(inode, dir, page);
		if (err)
			goto put_error;

		err = f2fs_init_security(inode, dir, name, page);
		if (err)
			goto put_error;
	} else {
		page = get_node_page(F2FS_SB(dir->i_sb), inode->i_ino);
		if (IS_ERR(page))
			return page;

		set_cold_node(inode, page);
	}

	init_dent_inode(name, page);

	/*
	 * This file should be checkpointed during fsync.
	 * We lost i_pino from now on.
	 */
	if (is_inode_flag_set(F2FS_I(inode), FI_INC_LINK)) {
		file_lost_pino(inode);
		inc_nlink(inode);
	}
	return page;

put_error:
	f2fs_put_page(page, 1);
	/* once the failed inode becomes a bad inode, i_mode is S_IFREG */
	truncate_inode_pages(&inode->i_data, 0);
	truncate_blocks(inode, 0);
	remove_dirty_dir_inode(inode);
error:
	remove_inode_page(inode);
	return ERR_PTR(err);
}

static void update_parent_metadata(struct inode *dir, struct inode *inode,
						unsigned int current_depth)
{
	if (is_inode_flag_set(F2FS_I(inode), FI_NEW_INODE)) {
		if (S_ISDIR(inode->i_mode)) {
			inc_nlink(dir);
			set_inode_flag(F2FS_I(dir), FI_UPDATE_DIR);
		}
		clear_inode_flag(F2FS_I(inode), FI_NEW_INODE);
	}
	dir->i_mtime = dir->i_ctime = CURRENT_TIME;
	mark_inode_dirty(dir);

	if (F2FS_I(dir)->i_current_depth != current_depth) {
		F2FS_I(dir)->i_current_depth = current_depth;
		set_inode_flag(F2FS_I(dir), FI_UPDATE_DIR);
	}

	if (is_inode_flag_set(F2FS_I(inode), FI_INC_LINK))
		clear_inode_flag(F2FS_I(inode), FI_INC_LINK);
}

static int room_for_filename(struct f2fs_dentry_block *dentry_blk, int slots)
{
	int bit_start = 0;
	int zero_start, zero_end;
next:
	zero_start = find_next_zero_bit_le(&dentry_blk->dentry_bitmap,
						NR_DENTRY_IN_BLOCK,
						bit_start);
	if (zero_start >= NR_DENTRY_IN_BLOCK)
		return NR_DENTRY_IN_BLOCK;

	zero_end = find_next_bit_le(&dentry_blk->dentry_bitmap,
						NR_DENTRY_IN_BLOCK,
						zero_start);
	if (zero_end - zero_start >= slots)
		return zero_start;

	bit_start = zero_end + 1;

	if (zero_end + 1 >= NR_DENTRY_IN_BLOCK)
		return NR_DENTRY_IN_BLOCK;
	goto next;
}

/*
 * Caller should grab and release a rwsem by calling f2fs_lock_op() and
 * f2fs_unlock_op().
 */
int __f2fs_add_link(struct inode *dir, const struct qstr *name,
						struct inode *inode)
{
	unsigned int bit_pos;
	unsigned int level;
	unsigned int current_depth;
	unsigned long bidx, block;
	f2fs_hash_t dentry_hash;
	struct f2fs_dir_entry *de;
	unsigned int nbucket, nblock;
	size_t namelen = name->len;
	struct page *dentry_page = NULL;
	struct f2fs_dentry_block *dentry_blk = NULL;
	int slots = GET_DENTRY_SLOTS(namelen);
	struct page *page;
	int err = 0;
	int i;

	dentry_hash = f2fs_dentry_hash(name->name, name->len);
	level = 0;
	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 (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 = get_new_data_page(dir, NULL, block, true);
		if (IS_ERR(dentry_page))
			return PTR_ERR(dentry_page);

		dentry_blk = kmap(dentry_page);
		bit_pos = room_for_filename(dentry_blk, slots);
		if (bit_pos < NR_DENTRY_IN_BLOCK)
			goto add_dentry;

		kunmap(dentry_page);
		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);

	down_write(&F2FS_I(inode)->i_sem);
	page = init_inode_metadata(inode, dir, name);
	if (IS_ERR(page)) {
		err = PTR_ERR(page);
		goto fail;
	}
	de = &dentry_blk->dentry[bit_pos];
	de->hash_code = dentry_hash;
	de->name_len = cpu_to_le16(namelen);
	memcpy(dentry_blk->filename[bit_pos], name->name, name->len);
	de->ino = cpu_to_le32(inode->i_ino);
	set_de_type(de, inode);
	for (i = 0; i < slots; i++)
		test_and_set_bit_le(bit_pos + i, &dentry_blk->dentry_bitmap);
	set_page_dirty(dentry_page);

	/* we don't need to mark_inode_dirty now */
	F2FS_I(inode)->i_pino = dir->i_ino;
	update_inode(inode, page);
	f2fs_put_page(page, 1);

	update_parent_metadata(dir, inode, current_depth);
fail:
	up_write(&F2FS_I(inode)->i_sem);

	if (is_inode_flag_set(F2FS_I(dir), FI_UPDATE_DIR)) {
		update_inode_page(dir);
		clear_inode_flag(F2FS_I(dir), FI_UPDATE_DIR);
	}
	kunmap(dentry_page);
	f2fs_put_page(dentry_page, 1);
	return err;
}

/*
 * 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 *inode)
{
	struct	f2fs_dentry_block *dentry_blk;
	unsigned int bit_pos;
	struct address_space *mapping = page->mapping;
	struct inode *dir = mapping->host;
	int slots = GET_DENTRY_SLOTS(le16_to_cpu(dentry->name_len));
	void *kaddr = page_address(page);
	int i;

	lock_page(page);
	f2fs_wait_on_page_writeback(page, DATA);

	dentry_blk = (struct f2fs_dentry_block *)kaddr;
	bit_pos = dentry - (struct f2fs_dir_entry *)dentry_blk->dentry;
	for (i = 0; i < slots; i++)
		test_and_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);
	kunmap(page); /* kunmap - pair of f2fs_find_entry */
	set_page_dirty(page);

	dir->i_ctime = dir->i_mtime = CURRENT_TIME;

	if (inode) {
		struct f2fs_sb_info *sbi = F2FS_SB(dir->i_sb);

		down_write(&F2FS_I(inode)->i_sem);

		if (S_ISDIR(inode->i_mode)) {
			drop_nlink(dir);
			update_inode_page(dir);
		}
		inode->i_ctime = CURRENT_TIME;
		drop_nlink(inode);
		if (S_ISDIR(inode->i_mode)) {
			drop_nlink(inode);
			i_size_write(inode, 0);
		}
		up_write(&F2FS_I(inode)->i_sem);
		update_inode_page(inode);

		if (inode->i_nlink == 0)
			add_orphan_inode(sbi, inode->i_ino);
		else
			release_orphan_inode(sbi);
	}

	if (bit_pos == NR_DENTRY_IN_BLOCK) {
		truncate_hole(dir, page->index, page->index + 1);
		clear_page_dirty_for_io(page);
		ClearPageUptodate(page);
		inode_dec_dirty_dents(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);

	for (bidx = 0; bidx < nblock; bidx++) {
		void *kaddr;
		dentry_page = get_lock_data_page(dir, bidx);
		if (IS_ERR(dentry_page)) {
			if (PTR_ERR(dentry_page) == -ENOENT)
				continue;
			else
				return false;
		}

		kaddr = kmap_atomic(dentry_page);
		dentry_blk = (struct f2fs_dentry_block *)kaddr;
		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);
		kunmap_atomic(kaddr);

		f2fs_put_page(dentry_page, 1);

		if (bit_pos < NR_DENTRY_IN_BLOCK)
			return false;
	}
	return true;
}

static int f2fs_readdir(struct file *file, struct dir_context *ctx)
{
	struct inode *inode = file_inode(file);
	unsigned long npages = dir_blocks(inode);
	unsigned int bit_pos = 0;
	struct f2fs_dentry_block *dentry_blk = NULL;
	struct f2fs_dir_entry *de = NULL;
	struct page *dentry_page = NULL;
	unsigned int n = ((unsigned long)ctx->pos / NR_DENTRY_IN_BLOCK);
	unsigned char d_type = DT_UNKNOWN;

	bit_pos = ((unsigned long)ctx->pos % NR_DENTRY_IN_BLOCK);

	for (; n < npages; n++) {
		dentry_page = get_lock_data_page(inode, n);
		if (IS_ERR(dentry_page))
			continue;

		dentry_blk = kmap(dentry_page);
		while (bit_pos < NR_DENTRY_IN_BLOCK) {
			bit_pos = find_next_bit_le(&dentry_blk->dentry_bitmap,
							NR_DENTRY_IN_BLOCK,
							bit_pos);
			if (bit_pos >= NR_DENTRY_IN_BLOCK)
				break;

			de = &dentry_blk->dentry[bit_pos];
			if (de->file_type < F2FS_FT_MAX)
				d_type = f2fs_filetype_table[de->file_type];
			else
				d_type = DT_UNKNOWN;
			if (!dir_emit(ctx,
					dentry_blk->filename[bit_pos],
					le16_to_cpu(de->name_len),
					le32_to_cpu(de->ino), d_type))
				goto stop;

			bit_pos += GET_DENTRY_SLOTS(le16_to_cpu(de->name_len));
			ctx->pos = n * NR_DENTRY_IN_BLOCK + bit_pos;
		}
		bit_pos = 0;
		ctx->pos = (n + 1) * NR_DENTRY_IN_BLOCK;
		kunmap(dentry_page);
		f2fs_put_page(dentry_page, 1);
		dentry_page = NULL;
	}
stop:
	if (dentry_page && !IS_ERR(dentry_page)) {
		kunmap(dentry_page);
		f2fs_put_page(dentry_page, 1);
	}

	return 0;
}

const struct file_operations f2fs_dir_operations = {
	.llseek		= generic_file_llseek,
	.read		= generic_read_dir,
	.iterate	= f2fs_readdir,
	.fsync		= f2fs_sync_file,
	.unlocked_ioctl	= f2fs_ioctl,
};
Commit	Line	Data
0a8165d7	1	/*
6b4ea016 JK	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"
398b1ac5	14	#include "node.h"
6b4ea016	15	#include "acl.h"
8ae8f162	16	#include "xattr.h"
6b4ea016 JK	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
38431545	24	static unsigned int dir_buckets(unsigned int level, int dir_level)
6b4ea016 JK	25	{
6b4ea016 JK	26	if (level < MAX_DIR_HASH_DEPTH / 2)
38431545	27	return 1 << (level + dir_level);
6b4ea016	28	else
38431545	29	return 1 << ((MAX_DIR_HASH_DEPTH / 2 + dir_level) - 1);
6b4ea016 JK	30	}
	31
	32	static unsigned int bucket_blocks(unsigned int level)
	33	{
	34	if (level < MAX_DIR_HASH_DEPTH / 2)
	35	return 2;
	36	else
	37	return 4;
	38	}
	39
	40	static unsigned char f2fs_filetype_table[F2FS_FT_MAX] = {
	41	[F2FS_FT_UNKNOWN] = DT_UNKNOWN,
	42	[F2FS_FT_REG_FILE] = DT_REG,
	43	[F2FS_FT_DIR] = DT_DIR,
	44	[F2FS_FT_CHRDEV] = DT_CHR,
	45	[F2FS_FT_BLKDEV] = DT_BLK,
	46	[F2FS_FT_FIFO] = DT_FIFO,
	47	[F2FS_FT_SOCK] = DT_SOCK,
	48	[F2FS_FT_SYMLINK] = DT_LNK,
	49	};
	50
	51	#define S_SHIFT 12
	52	static unsigned char f2fs_type_by_mode[S_IFMT >> S_SHIFT] = {
	53	[S_IFREG >> S_SHIFT] = F2FS_FT_REG_FILE,
	54	[S_IFDIR >> S_SHIFT] = F2FS_FT_DIR,
	55	[S_IFCHR >> S_SHIFT] = F2FS_FT_CHRDEV,
	56	[S_IFBLK >> S_SHIFT] = F2FS_FT_BLKDEV,
	57	[S_IFIFO >> S_SHIFT] = F2FS_FT_FIFO,
	58	[S_IFSOCK >> S_SHIFT] = F2FS_FT_SOCK,
	59	[S_IFLNK >> S_SHIFT] = F2FS_FT_SYMLINK,
	60	};
	61
	62	static void set_de_type(struct f2fs_dir_entry de, struct inode inode)
	63	{
0ecc833b	64	umode_t mode = inode->i_mode;
6b4ea016 JK	65	de->file_type = f2fs_type_by_mode[(mode & S_IFMT) >> S_SHIFT];
	66	}
	67
38431545 JK	68	static unsigned long dir_block_index(unsigned int level,
38431545 JK	69	int dir_level, unsigned int idx)
6b4ea016 JK	70	{
	71	unsigned long i;
	72	unsigned long bidx = 0;
	73
	74	for (i = 0; i < level; i++)
38431545	75	bidx += dir_buckets(i, dir_level) * bucket_blocks(i);
6b4ea016 JK	76	bidx += idx * bucket_blocks(level);
	77	return bidx;
	78	}
	79
9836b8b9	80	static bool early_match_name(const char *name, size_t namelen,
6b4ea016 JK	81	f2fs_hash_t namehash, struct f2fs_dir_entry *de)
	82	{
	83	if (le16_to_cpu(de->name_len) != namelen)
	84	return false;
	85
25ca923b	86	if (de->hash_code != namehash)
6b4ea016 JK	87	return false;
	88
	89	return true;
	90	}
	91
	92	static struct f2fs_dir_entry find_in_block(struct page dentry_page,
9836b8b9	93	const char name, size_t namelen, int max_slots,
6b4ea016 JK	94	f2fs_hash_t namehash, struct page **res_page)
	95	{
	96	struct f2fs_dir_entry *de;
5d0c6671	97	unsigned long bit_pos = 0;
6b4ea016	98	struct f2fs_dentry_block *dentry_blk = kmap(dentry_page);
20f70751	99	const void *dentry_bits = &dentry_blk->dentry_bitmap;
5d0c6671	100	int max_len = 0;
6b4ea016	101
6b4ea016	102	while (bit_pos < NR_DENTRY_IN_BLOCK) {
20f70751	103	if (!test_bit_le(bit_pos, dentry_bits)) {
5d0c6671 JK	104	if (bit_pos == 0)
5d0c6671 JK	105	max_len = 1;
20f70751	106	else if (!test_bit_le(bit_pos - 1, dentry_bits))
5d0c6671 JK	107	max_len++;
	108	bit_pos++;
	109	continue;
	110	}
20f70751	111	de = &dentry_blk->dentry[bit_pos];
6b4ea016 JK	112	if (early_match_name(name, namelen, namehash, de)) {
	113	if (!memcmp(dentry_blk->filename[bit_pos],
	114	name, namelen)) {
	115	*res_page = dentry_page;
	116	goto found;
	117	}
	118	}
5d0c6671 JK	119	if (max_len > *max_slots) {
	120	*max_slots = max_len;
	121	max_len = 0;
	122	}
	123	bit_pos += GET_DENTRY_SLOTS(le16_to_cpu(de->name_len));
6b4ea016 JK	124	}
	125
	126	de = NULL;
	127	kunmap(dentry_page);
	128	found:
5d0c6671 JK	129	if (max_len > *max_slots)
5d0c6671 JK	130	*max_slots = max_len;
6b4ea016 JK	131	return de;
	132	}
	133
	134	static struct f2fs_dir_entry find_in_level(struct inode dir,
9836b8b9	135	unsigned int level, const char *name, size_t namelen,
6b4ea016 JK	136	f2fs_hash_t namehash, struct page **res_page)
6b4ea016 JK	137	{
457d08ee	138	int s = GET_DENTRY_SLOTS(namelen);
6b4ea016 JK	139	unsigned int nbucket, nblock;
	140	unsigned int bidx, end_block;
	141	struct page *dentry_page;
	142	struct f2fs_dir_entry *de = NULL;
	143	bool room = false;
	144	int max_slots = 0;
	145
5d56b671	146	f2fs_bug_on(level > MAX_DIR_HASH_DEPTH);
6b4ea016	147
38431545	148	nbucket = dir_buckets(level, F2FS_I(dir)->i_dir_level);
6b4ea016 JK	149	nblock = bucket_blocks(level);
6b4ea016 JK	150
38431545 JK	151	bidx = dir_block_index(level, F2FS_I(dir)->i_dir_level,
38431545 JK	152	le32_to_cpu(namehash) % nbucket);
6b4ea016 JK	153	end_block = bidx + nblock;
	154
	155	for (; bidx < end_block; bidx++) {
	156	/* no need to allocate new dentry pages to all the indices */
c718379b	157	dentry_page = find_data_page(dir, bidx, true);
6b4ea016 JK	158	if (IS_ERR(dentry_page)) {
	159	room = true;
	160	continue;
	161	}
	162
	163	de = find_in_block(dentry_page, name, namelen,
	164	&max_slots, namehash, res_page);
	165	if (de)
	166	break;
	167
	168	if (max_slots >= s)
	169	room = true;
	170	f2fs_put_page(dentry_page, 0);
	171	}
	172
	173	if (!de && room && F2FS_I(dir)->chash != namehash) {
	174	F2FS_I(dir)->chash = namehash;
	175	F2FS_I(dir)->clevel = level;
	176	}
	177
	178	return de;
	179	}
	180
	181	/*
	182	* Find an entry in the specified directory with the wanted name.
	183	* It returns the page where the entry was found (as a parameter - res_page),
	184	* and the entry itself. Page is returned mapped and unlocked.
	185	* Entry is guaranteed to be valid.
	186	*/
	187	struct f2fs_dir_entry f2fs_find_entry(struct inode dir,
	188	struct qstr child, struct page *res_page)
	189	{
	190	const char *name = child->name;
9836b8b9	191	size_t namelen = child->len;
6b4ea016 JK	192	unsigned long npages = dir_blocks(dir);
	193	struct f2fs_dir_entry *de = NULL;
	194	f2fs_hash_t name_hash;
	195	unsigned int max_depth;
	196	unsigned int level;
	197
	198	if (npages == 0)
	199	return NULL;
	200
	201	*res_page = NULL;
	202
	203	name_hash = f2fs_dentry_hash(name, namelen);
	204	max_depth = F2FS_I(dir)->i_current_depth;
	205
	206	for (level = 0; level < max_depth; level++) {
	207	de = find_in_level(dir, level, name,
	208	namelen, name_hash, res_page);
	209	if (de)
	210	break;
	211	}
	212	if (!de && F2FS_I(dir)->chash != name_hash) {
	213	F2FS_I(dir)->chash = name_hash;
	214	F2FS_I(dir)->clevel = level - 1;
	215	}
	216	return de;
	217	}
	218
	219	struct f2fs_dir_entry f2fs_parent_dir(struct inode dir, struct page **p)
	220	{
4777f86b NJ	221	struct page *page;
	222	struct f2fs_dir_entry *de;
	223	struct f2fs_dentry_block *dentry_blk;
6b4ea016 JK	224
	225	page = get_lock_data_page(dir, 0);
	226	if (IS_ERR(page))
	227	return NULL;
	228
	229	dentry_blk = kmap(page);
	230	de = &dentry_blk->dentry[1];
	231	*p = page;
	232	unlock_page(page);
	233	return de;
	234	}
	235
	236	ino_t f2fs_inode_by_name(struct inode dir, struct qstr qstr)
	237	{
	238	ino_t res = 0;
	239	struct f2fs_dir_entry *de;
	240	struct page *page;
	241
	242	de = f2fs_find_entry(dir, qstr, &page);
	243	if (de) {
	244	res = le32_to_cpu(de->ino);
	245	kunmap(page);
	246	f2fs_put_page(page, 0);
	247	}
	248
	249	return res;
	250	}
	251
	252	void f2fs_set_link(struct inode dir, struct f2fs_dir_entry de,
	253	struct page page, struct inode inode)
	254	{
6b4ea016	255	lock_page(page);
3cb5ad15	256	f2fs_wait_on_page_writeback(page, DATA);
6b4ea016 JK	257	de->ino = cpu_to_le32(inode->i_ino);
	258	set_de_type(de, inode);
	259	kunmap(page);
	260	set_page_dirty(page);
	261	dir->i_mtime = dir->i_ctime = CURRENT_TIME;
	262	mark_inode_dirty(dir);
6666e6aa	263
6b4ea016	264	f2fs_put_page(page, 1);
6b4ea016 JK	265	}
6b4ea016 JK	266
44a83ff6	267	static void init_dent_inode(const struct qstr name, struct page ipage)
6b4ea016	268	{
58bfaf44	269	struct f2fs_inode *ri;
6b4ea016	270
53dc9a67	271	/* copy name info. to this inode page */
58bfaf44 JK	272	ri = F2FS_INODE(ipage);
	273	ri->i_namelen = cpu_to_le32(name->len);
	274	memcpy(ri->i_name, name->name, name->len);
6b4ea016 JK	275	set_page_dirty(ipage);
	276	}
	277
1cd14caf JK	278	int update_dent_inode(struct inode inode, const struct qstr name)
	279	{
	280	struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
	281	struct page *page;
	282
	283	page = get_node_page(sbi, inode->i_ino);
	284	if (IS_ERR(page))
	285	return PTR_ERR(page);
	286
	287	init_dent_inode(name, page);
	288	f2fs_put_page(page, 1);
	289
	290	return 0;
	291	}
	292
44a83ff6 JK	293	static int make_empty_dir(struct inode *inode,
44a83ff6 JK	294	struct inode parent, struct page page)
39936837 JK	295	{
	296	struct page *dentry_page;
	297	struct f2fs_dentry_block *dentry_blk;
	298	struct f2fs_dir_entry *de;
	299	void *kaddr;
	300
44a83ff6	301	dentry_page = get_new_data_page(inode, page, 0, true);
39936837 JK	302	if (IS_ERR(dentry_page))
	303	return PTR_ERR(dentry_page);
	304
	305	kaddr = kmap_atomic(dentry_page);
	306	dentry_blk = (struct f2fs_dentry_block *)kaddr;
	307
	308	de = &dentry_blk->dentry[0];
	309	de->name_len = cpu_to_le16(1);
	310	de->hash_code = 0;
	311	de->ino = cpu_to_le32(inode->i_ino);
	312	memcpy(dentry_blk->filename[0], ".", 1);
	313	set_de_type(de, inode);
	314
	315	de = &dentry_blk->dentry[1];
	316	de->hash_code = 0;
	317	de->name_len = cpu_to_le16(2);
	318	de->ino = cpu_to_le32(parent->i_ino);
	319	memcpy(dentry_blk->filename[1], "..", 2);
	320	set_de_type(de, inode);
	321
	322	test_and_set_bit_le(0, &dentry_blk->dentry_bitmap);
	323	test_and_set_bit_le(1, &dentry_blk->dentry_bitmap);
	324	kunmap_atomic(kaddr);
	325
	326	set_page_dirty(dentry_page);
	327	f2fs_put_page(dentry_page, 1);
	328	return 0;
	329	}
	330
44a83ff6	331	static struct page init_inode_metadata(struct inode inode,
69f24eac	332	struct inode dir, const struct qstr name)
6b4ea016	333	{
44a83ff6 JK	334	struct page *page;
	335	int err;
	336
6b4ea016	337	if (is_inode_flag_set(F2FS_I(inode), FI_NEW_INODE)) {
44a83ff6 JK	338	page = new_inode_page(inode, name);
	339	if (IS_ERR(page))
	340	return page;
6b4ea016 JK	341
6b4ea016 JK	342	if (S_ISDIR(inode->i_mode)) {
44a83ff6 JK	343	err = make_empty_dir(inode, dir, page);
	344	if (err)
	345	goto error;
6b4ea016 JK	346	}
6b4ea016 JK	347
2ed2d5b3	348	err = f2fs_init_acl(inode, dir, page);
44a83ff6	349	if (err)
a8865372	350	goto put_error;
44a83ff6	351
8ae8f162 JK	352	err = f2fs_init_security(inode, dir, name, page);
8ae8f162 JK	353	if (err)
a8865372	354	goto put_error;
6b4ea016	355	} else {
44a83ff6 JK	356	page = get_node_page(F2FS_SB(dir->i_sb), inode->i_ino);
	357	if (IS_ERR(page))
	358	return page;
	359
44a83ff6	360	set_cold_node(inode, page);
6b4ea016	361	}
44a83ff6 JK	362
	363	init_dent_inode(name, page);
	364
83d5d6f6 JK	365	/*
	366	* This file should be checkpointed during fsync.
	367	* We lost i_pino from now on.
	368	*/
6b4ea016	369	if (is_inode_flag_set(F2FS_I(inode), FI_INC_LINK)) {
354a3399	370	file_lost_pino(inode);
6b4ea016	371	inc_nlink(inode);
6b4ea016	372	}
44a83ff6 JK	373	return page;
44a83ff6 JK	374
a8865372	375	put_error:
44a83ff6	376	f2fs_put_page(page, 1);
bd859c65 JK	377	/* once the failed inode becomes a bad inode, i_mode is S_IFREG */
	378	truncate_inode_pages(&inode->i_data, 0);
	379	truncate_blocks(inode, 0);
	380	remove_dirty_dir_inode(inode);
a8865372	381	error:
44a83ff6 JK	382	remove_inode_page(inode);
44a83ff6 JK	383	return ERR_PTR(err);
6b4ea016 JK	384	}
	385
	386	static void update_parent_metadata(struct inode dir, struct inode inode,
	387	unsigned int current_depth)
	388	{
6b4ea016 JK	389	if (is_inode_flag_set(F2FS_I(inode), FI_NEW_INODE)) {
	390	if (S_ISDIR(inode->i_mode)) {
	391	inc_nlink(dir);
699489bb	392	set_inode_flag(F2FS_I(dir), FI_UPDATE_DIR);
6b4ea016 JK	393	}
	394	clear_inode_flag(F2FS_I(inode), FI_NEW_INODE);
	395	}
	396	dir->i_mtime = dir->i_ctime = CURRENT_TIME;
a18ff063 JK	397	mark_inode_dirty(dir);
a18ff063 JK	398
6b4ea016 JK	399	if (F2FS_I(dir)->i_current_depth != current_depth) {
6b4ea016 JK	400	F2FS_I(dir)->i_current_depth = current_depth;
699489bb	401	set_inode_flag(F2FS_I(dir), FI_UPDATE_DIR);
6b4ea016 JK	402	}
6b4ea016 JK	403
6b4ea016 JK	404	if (is_inode_flag_set(F2FS_I(inode), FI_INC_LINK))
	405	clear_inode_flag(F2FS_I(inode), FI_INC_LINK);
	406	}
	407
	408	static int room_for_filename(struct f2fs_dentry_block *dentry_blk, int slots)
	409	{
	410	int bit_start = 0;
	411	int zero_start, zero_end;
	412	next:
	413	zero_start = find_next_zero_bit_le(&dentry_blk->dentry_bitmap,
	414	NR_DENTRY_IN_BLOCK,
	415	bit_start);
	416	if (zero_start >= NR_DENTRY_IN_BLOCK)
	417	return NR_DENTRY_IN_BLOCK;
	418
	419	zero_end = find_next_bit_le(&dentry_blk->dentry_bitmap,
	420	NR_DENTRY_IN_BLOCK,
	421	zero_start);
	422	if (zero_end - zero_start >= slots)
	423	return zero_start;
	424
	425	bit_start = zero_end + 1;
	426
	427	if (zero_end + 1 >= NR_DENTRY_IN_BLOCK)
	428	return NR_DENTRY_IN_BLOCK;
	429	goto next;
	430	}
	431
39936837	432	/*
4f4124d0 CY	433	* Caller should grab and release a rwsem by calling f2fs_lock_op() and
4f4124d0 CY	434	* f2fs_unlock_op().
39936837	435	*/
6c311ec6 CF	436	int __f2fs_add_link(struct inode dir, const struct qstr name,
6c311ec6 CF	437	struct inode *inode)
6b4ea016 JK	438	{
	439	unsigned int bit_pos;
	440	unsigned int level;
	441	unsigned int current_depth;
	442	unsigned long bidx, block;
	443	f2fs_hash_t dentry_hash;
	444	struct f2fs_dir_entry *de;
	445	unsigned int nbucket, nblock;
b7f7a5e0	446	size_t namelen = name->len;
6b4ea016 JK	447	struct page *dentry_page = NULL;
6b4ea016 JK	448	struct f2fs_dentry_block *dentry_blk = NULL;
457d08ee	449	int slots = GET_DENTRY_SLOTS(namelen);
44a83ff6	450	struct page *page;
6b4ea016 JK	451	int err = 0;
	452	int i;
	453
b7f7a5e0	454	dentry_hash = f2fs_dentry_hash(name->name, name->len);
6b4ea016 JK	455	level = 0;
	456	current_depth = F2FS_I(dir)->i_current_depth;
	457	if (F2FS_I(dir)->chash == dentry_hash) {
	458	level = F2FS_I(dir)->clevel;
	459	F2FS_I(dir)->chash = 0;
	460	}
	461
	462	start:
cfb271d4	463	if (unlikely(current_depth == MAX_DIR_HASH_DEPTH))
6b4ea016 JK	464	return -ENOSPC;
	465
	466	/* Increase the depth, if required */
	467	if (level == current_depth)
	468	++current_depth;
	469
38431545	470	nbucket = dir_buckets(level, F2FS_I(dir)->i_dir_level);
6b4ea016 JK	471	nblock = bucket_blocks(level);
6b4ea016 JK	472
38431545 JK	473	bidx = dir_block_index(level, F2FS_I(dir)->i_dir_level,
38431545 JK	474	(le32_to_cpu(dentry_hash) % nbucket));
6b4ea016 JK	475
6b4ea016 JK	476	for (block = bidx; block <= (bidx + nblock - 1); block++) {
64aa7ed9	477	dentry_page = get_new_data_page(dir, NULL, block, true);
39936837	478	if (IS_ERR(dentry_page))
6b4ea016	479	return PTR_ERR(dentry_page);
6b4ea016 JK	480
	481	dentry_blk = kmap(dentry_page);
	482	bit_pos = room_for_filename(dentry_blk, slots);
	483	if (bit_pos < NR_DENTRY_IN_BLOCK)
	484	goto add_dentry;
	485
	486	kunmap(dentry_page);
	487	f2fs_put_page(dentry_page, 1);
6b4ea016 JK	488	}
	489
	490	/* Move to next level to find the empty slot for new dentry */
	491	++level;
	492	goto start;
	493	add_dentry:
3cb5ad15	494	f2fs_wait_on_page_writeback(dentry_page, DATA);
6b4ea016	495
d928bfbf	496	down_write(&F2FS_I(inode)->i_sem);
44a83ff6 JK	497	page = init_inode_metadata(inode, dir, name);
	498	if (IS_ERR(page)) {
	499	err = PTR_ERR(page);
	500	goto fail;
	501	}
6b4ea016	502	de = &dentry_blk->dentry[bit_pos];
25ca923b	503	de->hash_code = dentry_hash;
6b4ea016	504	de->name_len = cpu_to_le16(namelen);
b7f7a5e0	505	memcpy(dentry_blk->filename[bit_pos], name->name, name->len);
6b4ea016 JK	506	de->ino = cpu_to_le32(inode->i_ino);
	507	set_de_type(de, inode);
	508	for (i = 0; i < slots; i++)
	509	test_and_set_bit_le(bit_pos + i, &dentry_blk->dentry_bitmap);
	510	set_page_dirty(dentry_page);
6666e6aa	511
44a83ff6	512	/* we don't need to mark_inode_dirty now */
6666e6aa	513	F2FS_I(inode)->i_pino = dir->i_ino;
44a83ff6 JK	514	update_inode(inode, page);
	515	f2fs_put_page(page, 1);
	516
	517	update_parent_metadata(dir, inode, current_depth);
6b4ea016	518	fail:
d928bfbf JK	519	up_write(&F2FS_I(inode)->i_sem);
d928bfbf JK	520
924a2ddb JK	521	if (is_inode_flag_set(F2FS_I(dir), FI_UPDATE_DIR)) {
	522	update_inode_page(dir);
	523	clear_inode_flag(F2FS_I(dir), FI_UPDATE_DIR);
	524	}
6b4ea016 JK	525	kunmap(dentry_page);
6b4ea016 JK	526	f2fs_put_page(dentry_page, 1);
6b4ea016 JK	527	return err;
	528	}
	529
0a8165d7	530	/*
6b4ea016 JK	531	* It only removes the dentry from the dentry page,corresponding name
	532	* entry in name page does not need to be touched during deletion.
	533	*/
	534	void f2fs_delete_entry(struct f2fs_dir_entry dentry, struct page page,
	535	struct inode *inode)
	536	{
	537	struct f2fs_dentry_block *dentry_blk;
	538	unsigned int bit_pos;
	539	struct address_space *mapping = page->mapping;
	540	struct inode *dir = mapping->host;
457d08ee	541	int slots = GET_DENTRY_SLOTS(le16_to_cpu(dentry->name_len));
6b4ea016 JK	542	void *kaddr = page_address(page);
	543	int i;
	544
6b4ea016	545	lock_page(page);
3cb5ad15	546	f2fs_wait_on_page_writeback(page, DATA);
6b4ea016 JK	547
	548	dentry_blk = (struct f2fs_dentry_block *)kaddr;
	549	bit_pos = dentry - (struct f2fs_dir_entry *)dentry_blk->dentry;
	550	for (i = 0; i < slots; i++)
	551	test_and_clear_bit_le(bit_pos + i, &dentry_blk->dentry_bitmap);
	552
	553	/* Let's check and deallocate this dentry page */
	554	bit_pos = find_next_bit_le(&dentry_blk->dentry_bitmap,
	555	NR_DENTRY_IN_BLOCK,
	556	0);
	557	kunmap(page); /* kunmap - pair of f2fs_find_entry */
	558	set_page_dirty(page);
	559
	560	dir->i_ctime = dir->i_mtime = CURRENT_TIME;
	561
6b4ea016	562	if (inode) {
1fe54f9d JK	563	struct f2fs_sb_info *sbi = F2FS_SB(dir->i_sb);
1fe54f9d JK	564
d928bfbf JK	565	down_write(&F2FS_I(inode)->i_sem);
d928bfbf JK	566
e8dae604 JK	567	if (S_ISDIR(inode->i_mode)) {
	568	drop_nlink(dir);
	569	update_inode_page(dir);
	570	}
16379987	571	inode->i_ctime = CURRENT_TIME;
6b4ea016 JK	572	drop_nlink(inode);
	573	if (S_ISDIR(inode->i_mode)) {
	574	drop_nlink(inode);
	575	i_size_write(inode, 0);
	576	}
d928bfbf	577	up_write(&F2FS_I(inode)->i_sem);
39936837 JK	578	update_inode_page(inode);
39936837 JK	579
6b4ea016 JK	580	if (inode->i_nlink == 0)
6b4ea016 JK	581	add_orphan_inode(sbi, inode->i_ino);
cbd56e7d JK	582	else
cbd56e7d JK	583	release_orphan_inode(sbi);
6b4ea016 JK	584	}
	585
	586	if (bit_pos == NR_DENTRY_IN_BLOCK) {
6b4ea016 JK	587	truncate_hole(dir, page->index, page->index + 1);
	588	clear_page_dirty_for_io(page);
	589	ClearPageUptodate(page);
6b4ea016	590	inode_dec_dirty_dents(dir);
6b4ea016	591	}
508198be	592	f2fs_put_page(page, 1);
6b4ea016 JK	593	}
	594
	595	bool f2fs_empty_dir(struct inode *dir)
	596	{
	597	unsigned long bidx;
	598	struct page *dentry_page;
	599	unsigned int bit_pos;
	600	struct f2fs_dentry_block *dentry_blk;
	601	unsigned long nblock = dir_blocks(dir);
	602
	603	for (bidx = 0; bidx < nblock; bidx++) {
	604	void *kaddr;
	605	dentry_page = get_lock_data_page(dir, bidx);
	606	if (IS_ERR(dentry_page)) {
	607	if (PTR_ERR(dentry_page) == -ENOENT)
	608	continue;
	609	else
	610	return false;
	611	}
	612
	613	kaddr = kmap_atomic(dentry_page);
	614	dentry_blk = (struct f2fs_dentry_block *)kaddr;
	615	if (bidx == 0)
	616	bit_pos = 2;
	617	else
	618	bit_pos = 0;
	619	bit_pos = find_next_bit_le(&dentry_blk->dentry_bitmap,
	620	NR_DENTRY_IN_BLOCK,
	621	bit_pos);
	622	kunmap_atomic(kaddr);
	623
	624	f2fs_put_page(dentry_page, 1);
	625
	626	if (bit_pos < NR_DENTRY_IN_BLOCK)
	627	return false;
	628	}
	629	return true;
	630	}
	631
6f7f231e	632	static int f2fs_readdir(struct file file, struct dir_context ctx)
6b4ea016	633	{
496ad9aa	634	struct inode *inode = file_inode(file);
6b4ea016	635	unsigned long npages = dir_blocks(inode);
99b072bb	636	unsigned int bit_pos = 0;
6b4ea016 JK	637	struct f2fs_dentry_block *dentry_blk = NULL;
	638	struct f2fs_dir_entry *de = NULL;
	639	struct page *dentry_page = NULL;
6f7f231e	640	unsigned int n = ((unsigned long)ctx->pos / NR_DENTRY_IN_BLOCK);
6b4ea016	641	unsigned char d_type = DT_UNKNOWN;
6b4ea016	642
6f7f231e	643	bit_pos = ((unsigned long)ctx->pos % NR_DENTRY_IN_BLOCK);
6b4ea016	644
6c311ec6	645	for (; n < npages; n++) {
6b4ea016 JK	646	dentry_page = get_lock_data_page(inode, n);
	647	if (IS_ERR(dentry_page))
	648	continue;
	649
6b4ea016 JK	650	dentry_blk = kmap(dentry_page);
6b4ea016 JK	651	while (bit_pos < NR_DENTRY_IN_BLOCK) {
6b4ea016 JK	652	bit_pos = find_next_bit_le(&dentry_blk->dentry_bitmap,
	653	NR_DENTRY_IN_BLOCK,
	654	bit_pos);
	655	if (bit_pos >= NR_DENTRY_IN_BLOCK)
	656	break;
	657
	658	de = &dentry_blk->dentry[bit_pos];
6f7f231e AV	659	if (de->file_type < F2FS_FT_MAX)
	660	d_type = f2fs_filetype_table[de->file_type];
	661	else
	662	d_type = DT_UNKNOWN;
	663	if (!dir_emit(ctx,
99b072bb JK	664	dentry_blk->filename[bit_pos],
	665	le16_to_cpu(de->name_len),
	666	le32_to_cpu(de->ino), d_type))
	667	goto stop;
	668
	669	bit_pos += GET_DENTRY_SLOTS(le16_to_cpu(de->name_len));
	670	ctx->pos = n * NR_DENTRY_IN_BLOCK + bit_pos;
6b4ea016 JK	671	}
6b4ea016 JK	672	bit_pos = 0;
6f7f231e	673	ctx->pos = (n + 1) * NR_DENTRY_IN_BLOCK;
6b4ea016 JK	674	kunmap(dentry_page);
	675	f2fs_put_page(dentry_page, 1);
	676	dentry_page = NULL;
	677	}
99b072bb	678	stop:
6b4ea016 JK	679	if (dentry_page && !IS_ERR(dentry_page)) {
	680	kunmap(dentry_page);
	681	f2fs_put_page(dentry_page, 1);
	682	}
	683
	684	return 0;
	685	}
	686
	687	const struct file_operations f2fs_dir_operations = {
	688	.llseek = generic_file_llseek,
	689	.read = generic_read_dir,
6f7f231e	690	.iterate = f2fs_readdir,
6b4ea016 JK	691	.fsync = f2fs_sync_file,
	692	.unlocked_ioctl = f2fs_ioctl,
	693	};