[deliverable/linux.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)
{
	if (level < MAX_DIR_HASH_DEPTH / 2)
		return 1 << level;
	else
		return 1 << ((MAX_DIR_HASH_DEPTH / 2) - 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, unsigned int idx)
{
	unsigned long i;
	unsigned long bidx = 0;

	for (i = 0; i < level; i++)
		bidx += dir_buckets(i) * 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, end_pos, next_pos;
	struct f2fs_dentry_block *dentry_blk = kmap(dentry_page);
	int slots;

	bit_pos = find_next_bit_le(&dentry_blk->dentry_bitmap,
					NR_DENTRY_IN_BLOCK, 0);
	while (bit_pos < NR_DENTRY_IN_BLOCK) {
		de = &dentry_blk->dentry[bit_pos];
		slots = GET_DENTRY_SLOTS(le16_to_cpu(de->name_len));

		if (early_match_name(name, namelen, namehash, de)) {
			if (!memcmp(dentry_blk->filename[bit_pos],
							name, namelen)) {
				*res_page = dentry_page;
				goto found;
			}
		}
		next_pos = bit_pos + slots;
		bit_pos = find_next_bit_le(&dentry_blk->dentry_bitmap,
				NR_DENTRY_IN_BLOCK, next_pos);
		if (bit_pos >= NR_DENTRY_IN_BLOCK)
			end_pos = NR_DENTRY_IN_BLOCK;
		else
			end_pos = bit_pos;
		if (*max_slots < end_pos - next_pos)
			*max_slots = end_pos - next_pos;
	}

	de = NULL;
	kunmap(dentry_page);
found:
	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);
	nblock = bucket_blocks(level);

	bidx = dir_block_index(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);
	wait_on_page_writeback(page);
	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;

		wait_on_page_writeback(page);
	} else {
		page = get_node_page(F2FS_SB(dir->i_sb), inode->i_ino);
		if (IS_ERR(page))
			return page;

		wait_on_page_writeback(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);
	nblock = bucket_blocks(level);

	bidx = dir_block_index(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:
	wait_on_page_writeback(dentry_page);

	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:
	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;
	struct f2fs_sb_info *sbi = F2FS_SB(dir->i_sb);
	int slots = GET_DENTRY_SLOTS(le16_to_cpu(dentry->name_len));
	void *kaddr = page_address(page);
	int i;

	lock_page(page);
	wait_on_page_writeback(page);

	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) {
		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);
		}
		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);
		dec_page_count(sbi, F2FS_DIRTY_DENTS);
		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
	24	static unsigned int dir_buckets(unsigned int level)
	25	{
	26	if (level < MAX_DIR_HASH_DEPTH / 2)
	27	return 1 << level;
	28	else
	29	return 1 << ((MAX_DIR_HASH_DEPTH / 2) - 1);
	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
	68	static unsigned long dir_block_index(unsigned int 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) * bucket_blocks(i);
	75	bidx += idx * bucket_blocks(level);
	76	return bidx;
	77	}
	78
9836b8b9	79	static bool early_match_name(const char *name, size_t namelen,
6b4ea016 JK	80	f2fs_hash_t namehash, struct f2fs_dir_entry *de)
	81	{
	82	if (le16_to_cpu(de->name_len) != namelen)
	83	return false;
	84
25ca923b	85	if (de->hash_code != namehash)
6b4ea016 JK	86	return false;
	87
	88	return true;
	89	}
	90
	91	static struct f2fs_dir_entry find_in_block(struct page dentry_page,
9836b8b9	92	const char name, size_t namelen, int max_slots,
6b4ea016 JK	93	f2fs_hash_t namehash, struct page **res_page)
	94	{
	95	struct f2fs_dir_entry *de;
	96	unsigned long bit_pos, end_pos, next_pos;
	97	struct f2fs_dentry_block *dentry_blk = kmap(dentry_page);
	98	int slots;
	99
	100	bit_pos = find_next_bit_le(&dentry_blk->dentry_bitmap,
	101	NR_DENTRY_IN_BLOCK, 0);
	102	while (bit_pos < NR_DENTRY_IN_BLOCK) {
	103	de = &dentry_blk->dentry[bit_pos];
457d08ee	104	slots = GET_DENTRY_SLOTS(le16_to_cpu(de->name_len));
6b4ea016 JK	105
	106	if (early_match_name(name, namelen, namehash, de)) {
	107	if (!memcmp(dentry_blk->filename[bit_pos],
	108	name, namelen)) {
	109	*res_page = dentry_page;
	110	goto found;
	111	}
	112	}
	113	next_pos = bit_pos + slots;
	114	bit_pos = find_next_bit_le(&dentry_blk->dentry_bitmap,
	115	NR_DENTRY_IN_BLOCK, next_pos);
	116	if (bit_pos >= NR_DENTRY_IN_BLOCK)
	117	end_pos = NR_DENTRY_IN_BLOCK;
	118	else
	119	end_pos = bit_pos;
	120	if (*max_slots < end_pos - next_pos)
	121	*max_slots = end_pos - next_pos;
	122	}
	123
	124	de = NULL;
	125	kunmap(dentry_page);
	126	found:
	127	return de;
	128	}
	129
	130	static struct f2fs_dir_entry find_in_level(struct inode dir,
9836b8b9	131	unsigned int level, const char *name, size_t namelen,
6b4ea016 JK	132	f2fs_hash_t namehash, struct page **res_page)
6b4ea016 JK	133	{
457d08ee	134	int s = GET_DENTRY_SLOTS(namelen);
6b4ea016 JK	135	unsigned int nbucket, nblock;
	136	unsigned int bidx, end_block;
	137	struct page *dentry_page;
	138	struct f2fs_dir_entry *de = NULL;
	139	bool room = false;
	140	int max_slots = 0;
	141
5d56b671	142	f2fs_bug_on(level > MAX_DIR_HASH_DEPTH);
6b4ea016 JK	143
	144	nbucket = dir_buckets(level);
	145	nblock = bucket_blocks(level);
	146
25ca923b	147	bidx = dir_block_index(level, le32_to_cpu(namehash) % nbucket);
6b4ea016 JK	148	end_block = bidx + nblock;
	149
	150	for (; bidx < end_block; bidx++) {
	151	/* no need to allocate new dentry pages to all the indices */
c718379b	152	dentry_page = find_data_page(dir, bidx, true);
6b4ea016 JK	153	if (IS_ERR(dentry_page)) {
	154	room = true;
	155	continue;
	156	}
	157
	158	de = find_in_block(dentry_page, name, namelen,
	159	&max_slots, namehash, res_page);
	160	if (de)
	161	break;
	162
	163	if (max_slots >= s)
	164	room = true;
	165	f2fs_put_page(dentry_page, 0);
	166	}
	167
	168	if (!de && room && F2FS_I(dir)->chash != namehash) {
	169	F2FS_I(dir)->chash = namehash;
	170	F2FS_I(dir)->clevel = level;
	171	}
	172
	173	return de;
	174	}
	175
	176	/*
	177	* Find an entry in the specified directory with the wanted name.
	178	* It returns the page where the entry was found (as a parameter - res_page),
	179	* and the entry itself. Page is returned mapped and unlocked.
	180	* Entry is guaranteed to be valid.
	181	*/
	182	struct f2fs_dir_entry f2fs_find_entry(struct inode dir,
	183	struct qstr child, struct page *res_page)
	184	{
	185	const char *name = child->name;
9836b8b9	186	size_t namelen = child->len;
6b4ea016 JK	187	unsigned long npages = dir_blocks(dir);
	188	struct f2fs_dir_entry *de = NULL;
	189	f2fs_hash_t name_hash;
	190	unsigned int max_depth;
	191	unsigned int level;
	192
	193	if (npages == 0)
	194	return NULL;
	195
	196	*res_page = NULL;
	197
	198	name_hash = f2fs_dentry_hash(name, namelen);
	199	max_depth = F2FS_I(dir)->i_current_depth;
	200
	201	for (level = 0; level < max_depth; level++) {
	202	de = find_in_level(dir, level, name,
	203	namelen, name_hash, res_page);
	204	if (de)
	205	break;
	206	}
	207	if (!de && F2FS_I(dir)->chash != name_hash) {
	208	F2FS_I(dir)->chash = name_hash;
	209	F2FS_I(dir)->clevel = level - 1;
	210	}
	211	return de;
	212	}
	213
	214	struct f2fs_dir_entry f2fs_parent_dir(struct inode dir, struct page **p)
	215	{
4777f86b NJ	216	struct page *page;
	217	struct f2fs_dir_entry *de;
	218	struct f2fs_dentry_block *dentry_blk;
6b4ea016 JK	219
	220	page = get_lock_data_page(dir, 0);
	221	if (IS_ERR(page))
	222	return NULL;
	223
	224	dentry_blk = kmap(page);
	225	de = &dentry_blk->dentry[1];
	226	*p = page;
	227	unlock_page(page);
	228	return de;
	229	}
	230
	231	ino_t f2fs_inode_by_name(struct inode dir, struct qstr qstr)
	232	{
	233	ino_t res = 0;
	234	struct f2fs_dir_entry *de;
	235	struct page *page;
	236
	237	de = f2fs_find_entry(dir, qstr, &page);
	238	if (de) {
	239	res = le32_to_cpu(de->ino);
	240	kunmap(page);
	241	f2fs_put_page(page, 0);
	242	}
	243
	244	return res;
	245	}
	246
	247	void f2fs_set_link(struct inode dir, struct f2fs_dir_entry de,
	248	struct page page, struct inode inode)
	249	{
6b4ea016 JK	250	lock_page(page);
	251	wait_on_page_writeback(page);
	252	de->ino = cpu_to_le32(inode->i_ino);
	253	set_de_type(de, inode);
	254	kunmap(page);
	255	set_page_dirty(page);
	256	dir->i_mtime = dir->i_ctime = CURRENT_TIME;
	257	mark_inode_dirty(dir);
6666e6aa	258
6b4ea016	259	f2fs_put_page(page, 1);
6b4ea016 JK	260	}
6b4ea016 JK	261
44a83ff6	262	static void init_dent_inode(const struct qstr name, struct page ipage)
6b4ea016	263	{
58bfaf44	264	struct f2fs_inode *ri;
6b4ea016	265
53dc9a67	266	/* copy name info. to this inode page */
58bfaf44 JK	267	ri = F2FS_INODE(ipage);
	268	ri->i_namelen = cpu_to_le32(name->len);
	269	memcpy(ri->i_name, name->name, name->len);
6b4ea016 JK	270	set_page_dirty(ipage);
	271	}
	272
1cd14caf JK	273	int update_dent_inode(struct inode inode, const struct qstr name)
	274	{
	275	struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
	276	struct page *page;
	277
	278	page = get_node_page(sbi, inode->i_ino);
	279	if (IS_ERR(page))
	280	return PTR_ERR(page);
	281
	282	init_dent_inode(name, page);
	283	f2fs_put_page(page, 1);
	284
	285	return 0;
	286	}
	287
44a83ff6 JK	288	static int make_empty_dir(struct inode *inode,
44a83ff6 JK	289	struct inode parent, struct page page)
39936837 JK	290	{
	291	struct page *dentry_page;
	292	struct f2fs_dentry_block *dentry_blk;
	293	struct f2fs_dir_entry *de;
	294	void *kaddr;
	295
44a83ff6	296	dentry_page = get_new_data_page(inode, page, 0, true);
39936837 JK	297	if (IS_ERR(dentry_page))
	298	return PTR_ERR(dentry_page);
	299
	300	kaddr = kmap_atomic(dentry_page);
	301	dentry_blk = (struct f2fs_dentry_block *)kaddr;
	302
	303	de = &dentry_blk->dentry[0];
	304	de->name_len = cpu_to_le16(1);
	305	de->hash_code = 0;
	306	de->ino = cpu_to_le32(inode->i_ino);
	307	memcpy(dentry_blk->filename[0], ".", 1);
	308	set_de_type(de, inode);
	309
	310	de = &dentry_blk->dentry[1];
	311	de->hash_code = 0;
	312	de->name_len = cpu_to_le16(2);
	313	de->ino = cpu_to_le32(parent->i_ino);
	314	memcpy(dentry_blk->filename[1], "..", 2);
	315	set_de_type(de, inode);
	316
	317	test_and_set_bit_le(0, &dentry_blk->dentry_bitmap);
	318	test_and_set_bit_le(1, &dentry_blk->dentry_bitmap);
	319	kunmap_atomic(kaddr);
	320
	321	set_page_dirty(dentry_page);
	322	f2fs_put_page(dentry_page, 1);
	323	return 0;
	324	}
	325
44a83ff6	326	static struct page init_inode_metadata(struct inode inode,
69f24eac	327	struct inode dir, const struct qstr name)
6b4ea016	328	{
44a83ff6 JK	329	struct page *page;
	330	int err;
	331
6b4ea016	332	if (is_inode_flag_set(F2FS_I(inode), FI_NEW_INODE)) {
44a83ff6 JK	333	page = new_inode_page(inode, name);
	334	if (IS_ERR(page))
	335	return page;
6b4ea016 JK	336
6b4ea016 JK	337	if (S_ISDIR(inode->i_mode)) {
44a83ff6 JK	338	err = make_empty_dir(inode, dir, page);
	339	if (err)
	340	goto error;
6b4ea016 JK	341	}
6b4ea016 JK	342
2ed2d5b3	343	err = f2fs_init_acl(inode, dir, page);
44a83ff6	344	if (err)
a8865372	345	goto put_error;
44a83ff6	346
8ae8f162 JK	347	err = f2fs_init_security(inode, dir, name, page);
8ae8f162 JK	348	if (err)
a8865372	349	goto put_error;
8ae8f162	350
44a83ff6	351	wait_on_page_writeback(page);
6b4ea016	352	} else {
44a83ff6 JK	353	page = get_node_page(F2FS_SB(dir->i_sb), inode->i_ino);
	354	if (IS_ERR(page))
	355	return page;
	356
	357	wait_on_page_writeback(page);
	358	set_cold_node(inode, page);
6b4ea016	359	}
44a83ff6 JK	360
	361	init_dent_inode(name, page);
	362
83d5d6f6 JK	363	/*
	364	* This file should be checkpointed during fsync.
	365	* We lost i_pino from now on.
	366	*/
6b4ea016	367	if (is_inode_flag_set(F2FS_I(inode), FI_INC_LINK)) {
354a3399	368	file_lost_pino(inode);
6b4ea016	369	inc_nlink(inode);
6b4ea016	370	}
44a83ff6 JK	371	return page;
44a83ff6 JK	372
a8865372	373	put_error:
44a83ff6	374	f2fs_put_page(page, 1);
bd859c65 JK	375	/* once the failed inode becomes a bad inode, i_mode is S_IFREG */
	376	truncate_inode_pages(&inode->i_data, 0);
	377	truncate_blocks(inode, 0);
	378	remove_dirty_dir_inode(inode);
a8865372	379	error:
44a83ff6 JK	380	remove_inode_page(inode);
44a83ff6 JK	381	return ERR_PTR(err);
6b4ea016 JK	382	}
	383
	384	static void update_parent_metadata(struct inode dir, struct inode inode,
	385	unsigned int current_depth)
	386	{
6b4ea016 JK	387	if (is_inode_flag_set(F2FS_I(inode), FI_NEW_INODE)) {
	388	if (S_ISDIR(inode->i_mode)) {
	389	inc_nlink(dir);
699489bb	390	set_inode_flag(F2FS_I(dir), FI_UPDATE_DIR);
6b4ea016 JK	391	}
	392	clear_inode_flag(F2FS_I(inode), FI_NEW_INODE);
	393	}
	394	dir->i_mtime = dir->i_ctime = CURRENT_TIME;
a18ff063 JK	395	mark_inode_dirty(dir);
a18ff063 JK	396
6b4ea016 JK	397	if (F2FS_I(dir)->i_current_depth != current_depth) {
6b4ea016 JK	398	F2FS_I(dir)->i_current_depth = current_depth;
699489bb	399	set_inode_flag(F2FS_I(dir), FI_UPDATE_DIR);
6b4ea016 JK	400	}
6b4ea016 JK	401
6b4ea016 JK	402	if (is_inode_flag_set(F2FS_I(inode), FI_INC_LINK))
	403	clear_inode_flag(F2FS_I(inode), FI_INC_LINK);
	404	}
	405
	406	static int room_for_filename(struct f2fs_dentry_block *dentry_blk, int slots)
	407	{
	408	int bit_start = 0;
	409	int zero_start, zero_end;
	410	next:
	411	zero_start = find_next_zero_bit_le(&dentry_blk->dentry_bitmap,
	412	NR_DENTRY_IN_BLOCK,
	413	bit_start);
	414	if (zero_start >= NR_DENTRY_IN_BLOCK)
	415	return NR_DENTRY_IN_BLOCK;
	416
	417	zero_end = find_next_bit_le(&dentry_blk->dentry_bitmap,
	418	NR_DENTRY_IN_BLOCK,
	419	zero_start);
	420	if (zero_end - zero_start >= slots)
	421	return zero_start;
	422
	423	bit_start = zero_end + 1;
	424
	425	if (zero_end + 1 >= NR_DENTRY_IN_BLOCK)
	426	return NR_DENTRY_IN_BLOCK;
	427	goto next;
	428	}
	429
39936837	430	/*
4f4124d0 CY	431	* Caller should grab and release a rwsem by calling f2fs_lock_op() and
4f4124d0 CY	432	* f2fs_unlock_op().
39936837	433	*/
6c311ec6 CF	434	int __f2fs_add_link(struct inode dir, const struct qstr name,
6c311ec6 CF	435	struct inode *inode)
6b4ea016 JK	436	{
	437	unsigned int bit_pos;
	438	unsigned int level;
	439	unsigned int current_depth;
	440	unsigned long bidx, block;
	441	f2fs_hash_t dentry_hash;
	442	struct f2fs_dir_entry *de;
	443	unsigned int nbucket, nblock;
b7f7a5e0	444	size_t namelen = name->len;
6b4ea016 JK	445	struct page *dentry_page = NULL;
6b4ea016 JK	446	struct f2fs_dentry_block *dentry_blk = NULL;
457d08ee	447	int slots = GET_DENTRY_SLOTS(namelen);
44a83ff6	448	struct page *page;
6b4ea016 JK	449	int err = 0;
	450	int i;
	451
b7f7a5e0	452	dentry_hash = f2fs_dentry_hash(name->name, name->len);
6b4ea016 JK	453	level = 0;
	454	current_depth = F2FS_I(dir)->i_current_depth;
	455	if (F2FS_I(dir)->chash == dentry_hash) {
	456	level = F2FS_I(dir)->clevel;
	457	F2FS_I(dir)->chash = 0;
	458	}
	459
	460	start:
cfb271d4	461	if (unlikely(current_depth == MAX_DIR_HASH_DEPTH))
6b4ea016 JK	462	return -ENOSPC;
	463
	464	/* Increase the depth, if required */
	465	if (level == current_depth)
	466	++current_depth;
	467
	468	nbucket = dir_buckets(level);
	469	nblock = bucket_blocks(level);
	470
25ca923b	471	bidx = dir_block_index(level, (le32_to_cpu(dentry_hash) % nbucket));
6b4ea016 JK	472
6b4ea016 JK	473	for (block = bidx; block <= (bidx + nblock - 1); block++) {
64aa7ed9	474	dentry_page = get_new_data_page(dir, NULL, block, true);
39936837	475	if (IS_ERR(dentry_page))
6b4ea016	476	return PTR_ERR(dentry_page);
6b4ea016 JK	477
	478	dentry_blk = kmap(dentry_page);
	479	bit_pos = room_for_filename(dentry_blk, slots);
	480	if (bit_pos < NR_DENTRY_IN_BLOCK)
	481	goto add_dentry;
	482
	483	kunmap(dentry_page);
	484	f2fs_put_page(dentry_page, 1);
6b4ea016 JK	485	}
	486
	487	/* Move to next level to find the empty slot for new dentry */
	488	++level;
	489	goto start;
	490	add_dentry:
6b4ea016 JK	491	wait_on_page_writeback(dentry_page);
6b4ea016 JK	492
44a83ff6 JK	493	page = init_inode_metadata(inode, dir, name);
	494	if (IS_ERR(page)) {
	495	err = PTR_ERR(page);
	496	goto fail;
	497	}
6b4ea016	498	de = &dentry_blk->dentry[bit_pos];
25ca923b	499	de->hash_code = dentry_hash;
6b4ea016	500	de->name_len = cpu_to_le16(namelen);
b7f7a5e0	501	memcpy(dentry_blk->filename[bit_pos], name->name, name->len);
6b4ea016 JK	502	de->ino = cpu_to_le32(inode->i_ino);
	503	set_de_type(de, inode);
	504	for (i = 0; i < slots; i++)
	505	test_and_set_bit_le(bit_pos + i, &dentry_blk->dentry_bitmap);
	506	set_page_dirty(dentry_page);
6666e6aa	507
44a83ff6	508	/* we don't need to mark_inode_dirty now */
6666e6aa	509	F2FS_I(inode)->i_pino = dir->i_ino;
44a83ff6 JK	510	update_inode(inode, page);
	511	f2fs_put_page(page, 1);
	512
	513	update_parent_metadata(dir, inode, current_depth);
6b4ea016	514	fail:
924a2ddb JK	515	if (is_inode_flag_set(F2FS_I(dir), FI_UPDATE_DIR)) {
	516	update_inode_page(dir);
	517	clear_inode_flag(F2FS_I(dir), FI_UPDATE_DIR);
	518	}
6b4ea016 JK	519	kunmap(dentry_page);
6b4ea016 JK	520	f2fs_put_page(dentry_page, 1);
6b4ea016 JK	521	return err;
	522	}
	523
0a8165d7	524	/*
6b4ea016 JK	525	* It only removes the dentry from the dentry page,corresponding name
	526	* entry in name page does not need to be touched during deletion.
	527	*/
	528	void f2fs_delete_entry(struct f2fs_dir_entry dentry, struct page page,
	529	struct inode *inode)
	530	{
	531	struct f2fs_dentry_block *dentry_blk;
	532	unsigned int bit_pos;
	533	struct address_space *mapping = page->mapping;
	534	struct inode *dir = mapping->host;
	535	struct f2fs_sb_info *sbi = F2FS_SB(dir->i_sb);
457d08ee	536	int slots = GET_DENTRY_SLOTS(le16_to_cpu(dentry->name_len));
6b4ea016 JK	537	void *kaddr = page_address(page);
	538	int i;
	539
6b4ea016 JK	540	lock_page(page);
	541	wait_on_page_writeback(page);
	542
	543	dentry_blk = (struct f2fs_dentry_block *)kaddr;
	544	bit_pos = dentry - (struct f2fs_dir_entry *)dentry_blk->dentry;
	545	for (i = 0; i < slots; i++)
	546	test_and_clear_bit_le(bit_pos + i, &dentry_blk->dentry_bitmap);
	547
	548	/* Let's check and deallocate this dentry page */
	549	bit_pos = find_next_bit_le(&dentry_blk->dentry_bitmap,
	550	NR_DENTRY_IN_BLOCK,
	551	0);
	552	kunmap(page); /* kunmap - pair of f2fs_find_entry */
	553	set_page_dirty(page);
	554
	555	dir->i_ctime = dir->i_mtime = CURRENT_TIME;
	556
6b4ea016	557	if (inode) {
e8dae604 JK	558	if (S_ISDIR(inode->i_mode)) {
	559	drop_nlink(dir);
	560	update_inode_page(dir);
	561	}
16379987	562	inode->i_ctime = CURRENT_TIME;
6b4ea016 JK	563	drop_nlink(inode);
	564	if (S_ISDIR(inode->i_mode)) {
	565	drop_nlink(inode);
	566	i_size_write(inode, 0);
	567	}
39936837 JK	568	update_inode_page(inode);
39936837 JK	569
6b4ea016 JK	570	if (inode->i_nlink == 0)
6b4ea016 JK	571	add_orphan_inode(sbi, inode->i_ino);
cbd56e7d JK	572	else
cbd56e7d JK	573	release_orphan_inode(sbi);
6b4ea016 JK	574	}
	575
	576	if (bit_pos == NR_DENTRY_IN_BLOCK) {
6b4ea016 JK	577	truncate_hole(dir, page->index, page->index + 1);
	578	clear_page_dirty_for_io(page);
	579	ClearPageUptodate(page);
	580	dec_page_count(sbi, F2FS_DIRTY_DENTS);
	581	inode_dec_dirty_dents(dir);
6b4ea016	582	}
508198be	583	f2fs_put_page(page, 1);
6b4ea016 JK	584	}
	585
	586	bool f2fs_empty_dir(struct inode *dir)
	587	{
	588	unsigned long bidx;
	589	struct page *dentry_page;
	590	unsigned int bit_pos;
	591	struct f2fs_dentry_block *dentry_blk;
	592	unsigned long nblock = dir_blocks(dir);
	593
	594	for (bidx = 0; bidx < nblock; bidx++) {
	595	void *kaddr;
	596	dentry_page = get_lock_data_page(dir, bidx);
	597	if (IS_ERR(dentry_page)) {
	598	if (PTR_ERR(dentry_page) == -ENOENT)
	599	continue;
	600	else
	601	return false;
	602	}
	603
	604	kaddr = kmap_atomic(dentry_page);
	605	dentry_blk = (struct f2fs_dentry_block *)kaddr;
	606	if (bidx == 0)
	607	bit_pos = 2;
	608	else
	609	bit_pos = 0;
	610	bit_pos = find_next_bit_le(&dentry_blk->dentry_bitmap,
	611	NR_DENTRY_IN_BLOCK,
	612	bit_pos);
	613	kunmap_atomic(kaddr);
	614
	615	f2fs_put_page(dentry_page, 1);
	616
	617	if (bit_pos < NR_DENTRY_IN_BLOCK)
	618	return false;
	619	}
	620	return true;
	621	}
	622
6f7f231e	623	static int f2fs_readdir(struct file file, struct dir_context ctx)
6b4ea016	624	{
496ad9aa	625	struct inode *inode = file_inode(file);
6b4ea016	626	unsigned long npages = dir_blocks(inode);
99b072bb	627	unsigned int bit_pos = 0;
6b4ea016 JK	628	struct f2fs_dentry_block *dentry_blk = NULL;
	629	struct f2fs_dir_entry *de = NULL;
	630	struct page *dentry_page = NULL;
6f7f231e	631	unsigned int n = ((unsigned long)ctx->pos / NR_DENTRY_IN_BLOCK);
6b4ea016	632	unsigned char d_type = DT_UNKNOWN;
6b4ea016	633
6f7f231e	634	bit_pos = ((unsigned long)ctx->pos % NR_DENTRY_IN_BLOCK);
6b4ea016	635
6c311ec6	636	for (; n < npages; n++) {
6b4ea016 JK	637	dentry_page = get_lock_data_page(inode, n);
	638	if (IS_ERR(dentry_page))
	639	continue;
	640
6b4ea016 JK	641	dentry_blk = kmap(dentry_page);
6b4ea016 JK	642	while (bit_pos < NR_DENTRY_IN_BLOCK) {
6b4ea016 JK	643	bit_pos = find_next_bit_le(&dentry_blk->dentry_bitmap,
	644	NR_DENTRY_IN_BLOCK,
	645	bit_pos);
	646	if (bit_pos >= NR_DENTRY_IN_BLOCK)
	647	break;
	648
	649	de = &dentry_blk->dentry[bit_pos];
6f7f231e AV	650	if (de->file_type < F2FS_FT_MAX)
	651	d_type = f2fs_filetype_table[de->file_type];
	652	else
	653	d_type = DT_UNKNOWN;
	654	if (!dir_emit(ctx,
99b072bb JK	655	dentry_blk->filename[bit_pos],
	656	le16_to_cpu(de->name_len),
	657	le32_to_cpu(de->ino), d_type))
	658	goto stop;
	659
	660	bit_pos += GET_DENTRY_SLOTS(le16_to_cpu(de->name_len));
	661	ctx->pos = n * NR_DENTRY_IN_BLOCK + bit_pos;
6b4ea016 JK	662	}
6b4ea016 JK	663	bit_pos = 0;
6f7f231e	664	ctx->pos = (n + 1) * NR_DENTRY_IN_BLOCK;
6b4ea016 JK	665	kunmap(dentry_page);
	666	f2fs_put_page(dentry_page, 1);
	667	dentry_page = NULL;
	668	}
99b072bb	669	stop:
6b4ea016 JK	670	if (dentry_page && !IS_ERR(dentry_page)) {
	671	kunmap(dentry_page);
	672	f2fs_put_page(dentry_page, 1);
	673	}
	674
	675	return 0;
	676	}
	677
	678	const struct file_operations f2fs_dir_operations = {
	679	.llseek = generic_file_llseek,
	680	.read = generic_read_dir,
6f7f231e	681	.iterate = f2fs_readdir,
6b4ea016 JK	682	.fsync = f2fs_sync_file,
	683	.unlocked_ioctl = f2fs_ioctl,
	684	};