[mirror_ubuntu-artful-kernel.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 "acl.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)
{
	mode_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, int 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, int 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, int 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;

	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);
		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;
	int 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 = NULL;
	struct f2fs_dir_entry *de = NULL;
	struct f2fs_dentry_block *dentry_blk = NULL;

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

	mutex_lock_op(sbi, DENTRY_OPS);
	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);
	mutex_unlock_op(sbi, DENTRY_OPS);
}

void init_dent_inode(struct dentry *dentry, struct page *ipage)
{
	struct inode *dir = dentry->d_parent->d_inode;
	struct f2fs_node *rn;

	if (IS_ERR(ipage))
		return;

	wait_on_page_writeback(ipage);

	/* copy dentry info. to this inode page */
	rn = (struct f2fs_node *)page_address(ipage);
	rn->i.i_pino = cpu_to_le32(dir->i_ino);
	rn->i.i_namelen = cpu_to_le32(dentry->d_name.len);
	memcpy(rn->i.i_name, dentry->d_name.name, dentry->d_name.len);
	set_page_dirty(ipage);
}

static int init_inode_metadata(struct inode *inode, struct dentry *dentry)
{
	struct inode *dir = dentry->d_parent->d_inode;

	if (is_inode_flag_set(F2FS_I(inode), FI_NEW_INODE)) {
		int err;
		err = new_inode_page(inode, dentry);
		if (err)
			return err;

		if (S_ISDIR(inode->i_mode)) {
			err = f2fs_make_empty(inode, dir);
			if (err) {
				remove_inode_page(inode);
				return err;
			}
		}

		err = f2fs_init_acl(inode, dir);
		if (err) {
			remove_inode_page(inode);
			return err;
		}
	} else {
		struct page *ipage;
		ipage = get_node_page(F2FS_SB(dir->i_sb), inode->i_ino);
		if (IS_ERR(ipage))
			return PTR_ERR(ipage);
		init_dent_inode(dentry, ipage);
		f2fs_put_page(ipage, 1);
	}
	if (is_inode_flag_set(F2FS_I(inode), FI_INC_LINK)) {
		inc_nlink(inode);
		f2fs_write_inode(inode, NULL);
	}
	return 0;
}

static void update_parent_metadata(struct inode *dir, struct inode *inode,
						unsigned int current_depth)
{
	bool need_dir_update = false;

	if (is_inode_flag_set(F2FS_I(inode), FI_NEW_INODE)) {
		if (S_ISDIR(inode->i_mode)) {
			inc_nlink(dir);
			need_dir_update = true;
		}
		clear_inode_flag(F2FS_I(inode), FI_NEW_INODE);
	}
	dir->i_mtime = dir->i_ctime = CURRENT_TIME;
	if (F2FS_I(dir)->i_current_depth != current_depth) {
		F2FS_I(dir)->i_current_depth = current_depth;
		need_dir_update = true;
	}

	if (need_dir_update)
		f2fs_write_inode(dir, NULL);
	else
		mark_inode_dirty(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;
}

int f2fs_add_link(struct dentry *dentry, 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;
	struct inode *dir = dentry->d_parent->d_inode;
	struct f2fs_sb_info *sbi = F2FS_SB(dir->i_sb);
	const char *name = dentry->d_name.name;
	int namelen = dentry->d_name.len;
	struct page *dentry_page = NULL;
	struct f2fs_dentry_block *dentry_blk = NULL;
	int slots = GET_DENTRY_SLOTS(namelen);
	int err = 0;
	int i;

	dentry_hash = f2fs_dentry_hash(name, dentry->d_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 (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++) {
		mutex_lock_op(sbi, DENTRY_OPS);
		dentry_page = get_new_data_page(dir, block, true);
		if (IS_ERR(dentry_page)) {
			mutex_unlock_op(sbi, DENTRY_OPS);
			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);
		mutex_unlock_op(sbi, DENTRY_OPS);
	}

	/* Move to next level to find the empty slot for new dentry */
	++level;
	goto start;
add_dentry:
	err = init_inode_metadata(inode, dentry);
	if (err)
		goto fail;

	wait_on_page_writeback(dentry_page);

	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, namelen);
	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);
	update_parent_metadata(dir, inode, current_depth);
fail:
	kunmap(dentry_page);
	f2fs_put_page(dentry_page, 1);
	mutex_unlock_op(sbi, DENTRY_OPS);
	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;

	mutex_lock_op(sbi, DENTRY_OPS);

	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 && S_ISDIR(inode->i_mode)) {
		drop_nlink(dir);
		f2fs_write_inode(dir, NULL);
	} else {
		mark_inode_dirty(dir);
	}

	if (inode) {
		inode->i_ctime = dir->i_ctime = dir->i_mtime = CURRENT_TIME;
		drop_nlink(inode);
		if (S_ISDIR(inode->i_mode)) {
			drop_nlink(inode);
			i_size_write(inode, 0);
		}
		f2fs_write_inode(inode, NULL);
		if (inode->i_nlink == 0)
			add_orphan_inode(sbi, inode->i_ino);
	}

	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);

	mutex_unlock_op(sbi, DENTRY_OPS);
}

int f2fs_make_empty(struct inode *inode, struct inode *parent)
{
	struct page *dentry_page;
	struct f2fs_dentry_block *dentry_blk;
	struct f2fs_dir_entry *de;
	void *kaddr;

	dentry_page = get_new_data_page(inode, 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;
}

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, void *dirent, filldir_t filldir)
{
	unsigned long pos = file->f_pos;
	struct inode *inode = file->f_dentry->d_inode;
	unsigned long npages = dir_blocks(inode);
	unsigned char *types = NULL;
	unsigned int bit_pos = 0, start_bit_pos = 0;
	int over = 0;
	struct f2fs_dentry_block *dentry_blk = NULL;
	struct f2fs_dir_entry *de = NULL;
	struct page *dentry_page = NULL;
	unsigned int n = 0;
	unsigned char d_type = DT_UNKNOWN;
	int slots;

	types = f2fs_filetype_table;
	bit_pos = (pos % NR_DENTRY_IN_BLOCK);
	n = (pos / NR_DENTRY_IN_BLOCK);

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

		start_bit_pos = bit_pos;
		dentry_blk = kmap(dentry_page);
		while (bit_pos < NR_DENTRY_IN_BLOCK) {
			d_type = DT_UNKNOWN;
			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 (types && de->file_type < F2FS_FT_MAX)
				d_type = types[de->file_type];

			over = filldir(dirent,
					dentry_blk->filename[bit_pos],
					le16_to_cpu(de->name_len),
					(n * NR_DENTRY_IN_BLOCK) + bit_pos,
					le32_to_cpu(de->ino), d_type);
			if (over) {
				file->f_pos += bit_pos - start_bit_pos;
				goto success;
			}
			slots = GET_DENTRY_SLOTS(le16_to_cpu(de->name_len));
			bit_pos += slots;
		}
		bit_pos = 0;
		file->f_pos = (n + 1) * NR_DENTRY_IN_BLOCK;
		kunmap(dentry_page);
		f2fs_put_page(dentry_page, 1);
		dentry_page = NULL;
	}
success:
	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,
	.readdir	= 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"
	14	#include "acl.h"
	15
	16	static unsigned long dir_blocks(struct inode *inode)
	17	{
	18	return ((unsigned long long) (i_size_read(inode) + PAGE_CACHE_SIZE - 1))
	19	>> PAGE_CACHE_SHIFT;
	20	}
	21
	22	static unsigned int dir_buckets(unsigned int level)
	23	{
	24	if (level < MAX_DIR_HASH_DEPTH / 2)
	25	return 1 << level;
	26	else
	27	return 1 << ((MAX_DIR_HASH_DEPTH / 2) - 1);
	28	}
	29
	30	static unsigned int bucket_blocks(unsigned int level)
	31	{
	32	if (level < MAX_DIR_HASH_DEPTH / 2)
	33	return 2;
	34	else
	35	return 4;
	36	}
	37
	38	static unsigned char f2fs_filetype_table[F2FS_FT_MAX] = {
	39	[F2FS_FT_UNKNOWN] = DT_UNKNOWN,
	40	[F2FS_FT_REG_FILE] = DT_REG,
	41	[F2FS_FT_DIR] = DT_DIR,
	42	[F2FS_FT_CHRDEV] = DT_CHR,
	43	[F2FS_FT_BLKDEV] = DT_BLK,
	44	[F2FS_FT_FIFO] = DT_FIFO,
	45	[F2FS_FT_SOCK] = DT_SOCK,
	46	[F2FS_FT_SYMLINK] = DT_LNK,
	47	};
	48
	49	#define S_SHIFT 12
	50	static unsigned char f2fs_type_by_mode[S_IFMT >> S_SHIFT] = {
	51	[S_IFREG >> S_SHIFT] = F2FS_FT_REG_FILE,
	52	[S_IFDIR >> S_SHIFT] = F2FS_FT_DIR,
	53	[S_IFCHR >> S_SHIFT] = F2FS_FT_CHRDEV,
	54	[S_IFBLK >> S_SHIFT] = F2FS_FT_BLKDEV,
	55	[S_IFIFO >> S_SHIFT] = F2FS_FT_FIFO,
	56	[S_IFSOCK >> S_SHIFT] = F2FS_FT_SOCK,
	57	[S_IFLNK >> S_SHIFT] = F2FS_FT_SYMLINK,
	58	};
	59
	60	static void set_de_type(struct f2fs_dir_entry de, struct inode inode)
	61	{
	62	mode_t mode = inode->i_mode;
	63	de->file_type = f2fs_type_by_mode[(mode & S_IFMT) >> S_SHIFT];
	64	}
	65
66	static unsigned long dir_block_index(unsigned int level, unsigned int idx)
67	{
68	unsigned long i;
69	unsigned long bidx = 0;
70
71	for (i = 0; i < level; i++)
72	bidx += dir_buckets(i) * bucket_blocks(i);
73	bidx += idx * bucket_blocks(level);
74	return bidx;
75	}
76
77	static bool early_match_name(const char *name, int namelen,
78	f2fs_hash_t namehash, struct f2fs_dir_entry *de)
79	{
80	if (le16_to_cpu(de->name_len) != namelen)
81	return false;
82
25ca923b	83	if (de->hash_code != namehash)
6b4ea016 JK	84	return false;
	85
	86	return true;
	87	}
	88
	89	static struct f2fs_dir_entry find_in_block(struct page dentry_page,
	90	const char name, int namelen, int max_slots,
	91	f2fs_hash_t namehash, struct page **res_page)
	92	{
	93	struct f2fs_dir_entry *de;
	94	unsigned long bit_pos, end_pos, next_pos;
	95	struct f2fs_dentry_block *dentry_blk = kmap(dentry_page);
	96	int slots;
	97
	98	bit_pos = find_next_bit_le(&dentry_blk->dentry_bitmap,
	99	NR_DENTRY_IN_BLOCK, 0);
	100	while (bit_pos < NR_DENTRY_IN_BLOCK) {
	101	de = &dentry_blk->dentry[bit_pos];
457d08ee	102	slots = GET_DENTRY_SLOTS(le16_to_cpu(de->name_len));
6b4ea016 JK	103
	104	if (early_match_name(name, namelen, namehash, de)) {
	105	if (!memcmp(dentry_blk->filename[bit_pos],
	106	name, namelen)) {
	107	*res_page = dentry_page;
	108	goto found;
	109	}
	110	}
	111	next_pos = bit_pos + slots;
	112	bit_pos = find_next_bit_le(&dentry_blk->dentry_bitmap,
	113	NR_DENTRY_IN_BLOCK, next_pos);
	114	if (bit_pos >= NR_DENTRY_IN_BLOCK)
	115	end_pos = NR_DENTRY_IN_BLOCK;
	116	else
	117	end_pos = bit_pos;
	118	if (*max_slots < end_pos - next_pos)
	119	*max_slots = end_pos - next_pos;
	120	}
	121
	122	de = NULL;
	123	kunmap(dentry_page);
	124	found:
	125	return de;
	126	}
	127
	128	static struct f2fs_dir_entry find_in_level(struct inode dir,
	129	unsigned int level, const char *name, int namelen,
	130	f2fs_hash_t namehash, struct page **res_page)
	131	{
457d08ee	132	int s = GET_DENTRY_SLOTS(namelen);
6b4ea016 JK	133	unsigned int nbucket, nblock;
	134	unsigned int bidx, end_block;
	135	struct page *dentry_page;
	136	struct f2fs_dir_entry *de = NULL;
	137	bool room = false;
	138	int max_slots = 0;
	139
	140	BUG_ON(level > MAX_DIR_HASH_DEPTH);
	141
	142	nbucket = dir_buckets(level);
	143	nblock = bucket_blocks(level);
	144
25ca923b	145	bidx = dir_block_index(level, le32_to_cpu(namehash) % nbucket);
6b4ea016 JK	146	end_block = bidx + nblock;
	147
	148	for (; bidx < end_block; bidx++) {
	149	/* no need to allocate new dentry pages to all the indices */
	150	dentry_page = find_data_page(dir, bidx);
	151	if (IS_ERR(dentry_page)) {
	152	room = true;
	153	continue;
	154	}
	155
	156	de = find_in_block(dentry_page, name, namelen,
	157	&max_slots, namehash, res_page);
	158	if (de)
	159	break;
	160
	161	if (max_slots >= s)
	162	room = true;
	163	f2fs_put_page(dentry_page, 0);
	164	}
	165
	166	if (!de && room && F2FS_I(dir)->chash != namehash) {
	167	F2FS_I(dir)->chash = namehash;
	168	F2FS_I(dir)->clevel = level;
	169	}
	170
	171	return de;
	172	}
	173
	174	/*
	175	* Find an entry in the specified directory with the wanted name.
	176	* It returns the page where the entry was found (as a parameter - res_page),
	177	* and the entry itself. Page is returned mapped and unlocked.
	178	* Entry is guaranteed to be valid.
	179	*/
	180	struct f2fs_dir_entry f2fs_find_entry(struct inode dir,
	181	struct qstr child, struct page *res_page)
	182	{
	183	const char *name = child->name;
	184	int namelen = child->len;
	185	unsigned long npages = dir_blocks(dir);
	186	struct f2fs_dir_entry *de = NULL;
	187	f2fs_hash_t name_hash;
	188	unsigned int max_depth;
	189	unsigned int level;
	190
	191	if (npages == 0)
	192	return NULL;
	193
	194	*res_page = NULL;
	195
	196	name_hash = f2fs_dentry_hash(name, namelen);
	197	max_depth = F2FS_I(dir)->i_current_depth;
	198
	199	for (level = 0; level < max_depth; level++) {
	200	de = find_in_level(dir, level, name,
	201	namelen, name_hash, res_page);
	202	if (de)
	203	break;
	204	}
	205	if (!de && F2FS_I(dir)->chash != name_hash) {
	206	F2FS_I(dir)->chash = name_hash;
	207	F2FS_I(dir)->clevel = level - 1;
	208	}
	209	return de;
210	}
211
212	struct f2fs_dir_entry f2fs_parent_dir(struct inode dir, struct page **p)
213	{
214	struct page *page = NULL;
215	struct f2fs_dir_entry *de = NULL;
216	struct f2fs_dentry_block *dentry_blk = NULL;
217
218	page = get_lock_data_page(dir, 0);
219	if (IS_ERR(page))
220	return NULL;
221
222	dentry_blk = kmap(page);
223	de = &dentry_blk->dentry[1];
224	*p = page;
225	unlock_page(page);
226	return de;
227	}
228
229	ino_t f2fs_inode_by_name(struct inode dir, struct qstr qstr)
230	{
231	ino_t res = 0;
232	struct f2fs_dir_entry *de;
233	struct page *page;
234
235	de = f2fs_find_entry(dir, qstr, &page);
236	if (de) {
237	res = le32_to_cpu(de->ino);
238	kunmap(page);
239	f2fs_put_page(page, 0);
240	}
241
242	return res;
243	}
244
245	void f2fs_set_link(struct inode dir, struct f2fs_dir_entry de,
246	struct page page, struct inode inode)
247	{
248	struct f2fs_sb_info *sbi = F2FS_SB(dir->i_sb);
249
250	mutex_lock_op(sbi, DENTRY_OPS);
251	lock_page(page);
252	wait_on_page_writeback(page);
253	de->ino = cpu_to_le32(inode->i_ino);
254	set_de_type(de, inode);
255	kunmap(page);
256	set_page_dirty(page);
257	dir->i_mtime = dir->i_ctime = CURRENT_TIME;
258	mark_inode_dirty(dir);
259	f2fs_put_page(page, 1);
260	mutex_unlock_op(sbi, DENTRY_OPS);
261	}
262
263	void init_dent_inode(struct dentry dentry, struct page ipage)
264	{
265	struct inode *dir = dentry->d_parent->d_inode;
266	struct f2fs_node *rn;
267
268	if (IS_ERR(ipage))
269	return;
270
271	wait_on_page_writeback(ipage);
272
273	/* copy dentry info. to this inode page */
274	rn = (struct f2fs_node *)page_address(ipage);
275	rn->i.i_pino = cpu_to_le32(dir->i_ino);
276	rn->i.i_namelen = cpu_to_le32(dentry->d_name.len);
277	memcpy(rn->i.i_name, dentry->d_name.name, dentry->d_name.len);
278	set_page_dirty(ipage);
279	}
280
281	static int init_inode_metadata(struct inode inode, struct dentry dentry)
282	{
283	struct inode *dir = dentry->d_parent->d_inode;
284
285	if (is_inode_flag_set(F2FS_I(inode), FI_NEW_INODE)) {
286	int err;
287	err = new_inode_page(inode, dentry);
288	if (err)
289	return err;
290
291	if (S_ISDIR(inode->i_mode)) {
292	err = f2fs_make_empty(inode, dir);
293	if (err) {
294	remove_inode_page(inode);
295	return err;
296	}
297	}
298
299	err = f2fs_init_acl(inode, dir);
300	if (err) {
301	remove_inode_page(inode);
302	return err;
303	}
304	} else {
305	struct page *ipage;
306	ipage = get_node_page(F2FS_SB(dir->i_sb), inode->i_ino);
307	if (IS_ERR(ipage))
308	return PTR_ERR(ipage);
309	init_dent_inode(dentry, ipage);
310	f2fs_put_page(ipage, 1);
311	}
312	if (is_inode_flag_set(F2FS_I(inode), FI_INC_LINK)) {
313	inc_nlink(inode);
314	f2fs_write_inode(inode, NULL);
315	}
316	return 0;
317	}
318
319	static void update_parent_metadata(struct inode dir, struct inode inode,
320	unsigned int current_depth)
321	{
322	bool need_dir_update = false;
323
324	if (is_inode_flag_set(F2FS_I(inode), FI_NEW_INODE)) {
325	if (S_ISDIR(inode->i_mode)) {
326	inc_nlink(dir);
327	need_dir_update = true;
328	}
329	clear_inode_flag(F2FS_I(inode), FI_NEW_INODE);
330	}
331	dir->i_mtime = dir->i_ctime = CURRENT_TIME;
332	if (F2FS_I(dir)->i_current_depth != current_depth) {
333	F2FS_I(dir)->i_current_depth = current_depth;
334	need_dir_update = true;
335	}
336
337	if (need_dir_update)
338	f2fs_write_inode(dir, NULL);
339	else
340	mark_inode_dirty(dir);
341
342	if (is_inode_flag_set(F2FS_I(inode), FI_INC_LINK))
343	clear_inode_flag(F2FS_I(inode), FI_INC_LINK);
344	}
345
346	static int room_for_filename(struct f2fs_dentry_block *dentry_blk, int slots)
347	{
348	int bit_start = 0;
349	int zero_start, zero_end;
350	next:
351	zero_start = find_next_zero_bit_le(&dentry_blk->dentry_bitmap,
352	NR_DENTRY_IN_BLOCK,
353	bit_start);
354	if (zero_start >= NR_DENTRY_IN_BLOCK)
355	return NR_DENTRY_IN_BLOCK;
356
357	zero_end = find_next_bit_le(&dentry_blk->dentry_bitmap,
358	NR_DENTRY_IN_BLOCK,
359	zero_start);
360	if (zero_end - zero_start >= slots)
361	return zero_start;
362
363	bit_start = zero_end + 1;
364
365	if (zero_end + 1 >= NR_DENTRY_IN_BLOCK)
366	return NR_DENTRY_IN_BLOCK;
367	goto next;
368	}
369
370	int f2fs_add_link(struct dentry dentry, struct inode inode)
371	{
372	unsigned int bit_pos;
373	unsigned int level;
374	unsigned int current_depth;
375	unsigned long bidx, block;
376	f2fs_hash_t dentry_hash;
377	struct f2fs_dir_entry *de;
378	unsigned int nbucket, nblock;
379	struct inode *dir = dentry->d_parent->d_inode;
380	struct f2fs_sb_info *sbi = F2FS_SB(dir->i_sb);
381	const char *name = dentry->d_name.name;
382	int namelen = dentry->d_name.len;
383	struct page *dentry_page = NULL;
384	struct f2fs_dentry_block *dentry_blk = NULL;
457d08ee	385	int slots = GET_DENTRY_SLOTS(namelen);
6b4ea016 JK	386	int err = 0;
	387	int i;
	388
	389	dentry_hash = f2fs_dentry_hash(name, dentry->d_name.len);
	390	level = 0;
	391	current_depth = F2FS_I(dir)->i_current_depth;
	392	if (F2FS_I(dir)->chash == dentry_hash) {
	393	level = F2FS_I(dir)->clevel;
	394	F2FS_I(dir)->chash = 0;
	395	}
	396
	397	start:
	398	if (current_depth == MAX_DIR_HASH_DEPTH)
	399	return -ENOSPC;
	400
	401	/* Increase the depth, if required */
	402	if (level == current_depth)
	403	++current_depth;
	404
	405	nbucket = dir_buckets(level);
	406	nblock = bucket_blocks(level);
	407
25ca923b	408	bidx = dir_block_index(level, (le32_to_cpu(dentry_hash) % nbucket));
6b4ea016 JK	409
	410	for (block = bidx; block <= (bidx + nblock - 1); block++) {
	411	mutex_lock_op(sbi, DENTRY_OPS);
	412	dentry_page = get_new_data_page(dir, block, true);
	413	if (IS_ERR(dentry_page)) {
	414	mutex_unlock_op(sbi, DENTRY_OPS);
	415	return PTR_ERR(dentry_page);
	416	}
	417
	418	dentry_blk = kmap(dentry_page);
	419	bit_pos = room_for_filename(dentry_blk, slots);
	420	if (bit_pos < NR_DENTRY_IN_BLOCK)
	421	goto add_dentry;
	422
	423	kunmap(dentry_page);
	424	f2fs_put_page(dentry_page, 1);
	425	mutex_unlock_op(sbi, DENTRY_OPS);
	426	}
	427
	428	/* Move to next level to find the empty slot for new dentry */
	429	++level;
	430	goto start;
	431	add_dentry:
	432	err = init_inode_metadata(inode, dentry);
	433	if (err)
	434	goto fail;
	435
	436	wait_on_page_writeback(dentry_page);
	437
	438	de = &dentry_blk->dentry[bit_pos];
25ca923b	439	de->hash_code = dentry_hash;
6b4ea016 JK	440	de->name_len = cpu_to_le16(namelen);
	441	memcpy(dentry_blk->filename[bit_pos], name, namelen);
	442	de->ino = cpu_to_le32(inode->i_ino);
	443	set_de_type(de, inode);
	444	for (i = 0; i < slots; i++)
	445	test_and_set_bit_le(bit_pos + i, &dentry_blk->dentry_bitmap);
	446	set_page_dirty(dentry_page);
	447	update_parent_metadata(dir, inode, current_depth);
	448	fail:
	449	kunmap(dentry_page);
	450	f2fs_put_page(dentry_page, 1);
	451	mutex_unlock_op(sbi, DENTRY_OPS);
	452	return err;
	453	}
	454
0a8165d7	455	/*
6b4ea016 JK	456	* It only removes the dentry from the dentry page,corresponding name
	457	* entry in name page does not need to be touched during deletion.
	458	*/
	459	void f2fs_delete_entry(struct f2fs_dir_entry dentry, struct page page,
	460	struct inode *inode)
	461	{
	462	struct f2fs_dentry_block *dentry_blk;
	463	unsigned int bit_pos;
	464	struct address_space *mapping = page->mapping;
	465	struct inode *dir = mapping->host;
	466	struct f2fs_sb_info *sbi = F2FS_SB(dir->i_sb);
457d08ee	467	int slots = GET_DENTRY_SLOTS(le16_to_cpu(dentry->name_len));
6b4ea016 JK	468	void *kaddr = page_address(page);
	469	int i;
	470
	471	mutex_lock_op(sbi, DENTRY_OPS);
	472
	473	lock_page(page);
	474	wait_on_page_writeback(page);
	475
	476	dentry_blk = (struct f2fs_dentry_block *)kaddr;
	477	bit_pos = dentry - (struct f2fs_dir_entry *)dentry_blk->dentry;
	478	for (i = 0; i < slots; i++)
	479	test_and_clear_bit_le(bit_pos + i, &dentry_blk->dentry_bitmap);
	480
	481	/* Let's check and deallocate this dentry page */
	482	bit_pos = find_next_bit_le(&dentry_blk->dentry_bitmap,
	483	NR_DENTRY_IN_BLOCK,
	484	0);
	485	kunmap(page); /* kunmap - pair of f2fs_find_entry */
	486	set_page_dirty(page);
	487
	488	dir->i_ctime = dir->i_mtime = CURRENT_TIME;
	489
	490	if (inode && S_ISDIR(inode->i_mode)) {
	491	drop_nlink(dir);
	492	f2fs_write_inode(dir, NULL);
	493	} else {
	494	mark_inode_dirty(dir);
	495	}
	496
	497	if (inode) {
	498	inode->i_ctime = dir->i_ctime = dir->i_mtime = CURRENT_TIME;
	499	drop_nlink(inode);
	500	if (S_ISDIR(inode->i_mode)) {
	501	drop_nlink(inode);
	502	i_size_write(inode, 0);
	503	}
	504	f2fs_write_inode(inode, NULL);
	505	if (inode->i_nlink == 0)
	506	add_orphan_inode(sbi, inode->i_ino);
	507	}
	508
	509	if (bit_pos == NR_DENTRY_IN_BLOCK) {
6b4ea016 JK	510	truncate_hole(dir, page->index, page->index + 1);
	511	clear_page_dirty_for_io(page);
	512	ClearPageUptodate(page);
	513	dec_page_count(sbi, F2FS_DIRTY_DENTS);
	514	inode_dec_dirty_dents(dir);
6b4ea016	515	}
508198be NJ	516	f2fs_put_page(page, 1);
508198be NJ	517
6b4ea016 JK	518	mutex_unlock_op(sbi, DENTRY_OPS);
	519	}
	520
	521	int f2fs_make_empty(struct inode inode, struct inode parent)
	522	{
	523	struct page *dentry_page;
	524	struct f2fs_dentry_block *dentry_blk;
	525	struct f2fs_dir_entry *de;
	526	void *kaddr;
	527
	528	dentry_page = get_new_data_page(inode, 0, true);
	529	if (IS_ERR(dentry_page))
	530	return PTR_ERR(dentry_page);
	531
	532	kaddr = kmap_atomic(dentry_page);
	533	dentry_blk = (struct f2fs_dentry_block *)kaddr;
	534
	535	de = &dentry_blk->dentry[0];
	536	de->name_len = cpu_to_le16(1);
	537	de->hash_code = 0;
	538	de->ino = cpu_to_le32(inode->i_ino);
	539	memcpy(dentry_blk->filename[0], ".", 1);
	540	set_de_type(de, inode);
	541
	542	de = &dentry_blk->dentry[1];
	543	de->hash_code = 0;
	544	de->name_len = cpu_to_le16(2);
	545	de->ino = cpu_to_le32(parent->i_ino);
	546	memcpy(dentry_blk->filename[1], "..", 2);
	547	set_de_type(de, inode);
	548
	549	test_and_set_bit_le(0, &dentry_blk->dentry_bitmap);
	550	test_and_set_bit_le(1, &dentry_blk->dentry_bitmap);
	551	kunmap_atomic(kaddr);
	552
	553	set_page_dirty(dentry_page);
	554	f2fs_put_page(dentry_page, 1);
	555	return 0;
	556	}
	557
	558	bool f2fs_empty_dir(struct inode *dir)
	559	{
	560	unsigned long bidx;
	561	struct page *dentry_page;
	562	unsigned int bit_pos;
	563	struct f2fs_dentry_block *dentry_blk;
	564	unsigned long nblock = dir_blocks(dir);
	565
	566	for (bidx = 0; bidx < nblock; bidx++) {
	567	void *kaddr;
	568	dentry_page = get_lock_data_page(dir, bidx);
	569	if (IS_ERR(dentry_page)) {
	570	if (PTR_ERR(dentry_page) == -ENOENT)
	571	continue;
	572	else
	573	return false;
	574	}
	575
	576	kaddr = kmap_atomic(dentry_page);
	577	dentry_blk = (struct f2fs_dentry_block *)kaddr;
	578	if (bidx == 0)
	579	bit_pos = 2;
	580	else
	581	bit_pos = 0;
582	bit_pos = find_next_bit_le(&dentry_blk->dentry_bitmap,
583	NR_DENTRY_IN_BLOCK,
584	bit_pos);
585	kunmap_atomic(kaddr);
586
587	f2fs_put_page(dentry_page, 1);
588
589	if (bit_pos < NR_DENTRY_IN_BLOCK)
590	return false;
591	}
592	return true;
593	}
594
595	static int f2fs_readdir(struct file file, void dirent, filldir_t filldir)
596	{
597	unsigned long pos = file->f_pos;
598	struct inode *inode = file->f_dentry->d_inode;
599	unsigned long npages = dir_blocks(inode);
600	unsigned char *types = NULL;
601	unsigned int bit_pos = 0, start_bit_pos = 0;
602	int over = 0;
603	struct f2fs_dentry_block *dentry_blk = NULL;
604	struct f2fs_dir_entry *de = NULL;
605	struct page *dentry_page = NULL;
606	unsigned int n = 0;
607	unsigned char d_type = DT_UNKNOWN;
608	int slots;
609
610	types = f2fs_filetype_table;
611	bit_pos = (pos % NR_DENTRY_IN_BLOCK);
612	n = (pos / NR_DENTRY_IN_BLOCK);
613
614	for ( ; n < npages; n++) {
615	dentry_page = get_lock_data_page(inode, n);
616	if (IS_ERR(dentry_page))
617	continue;
618
619	start_bit_pos = bit_pos;
620	dentry_blk = kmap(dentry_page);
621	while (bit_pos < NR_DENTRY_IN_BLOCK) {
622	d_type = DT_UNKNOWN;
623	bit_pos = find_next_bit_le(&dentry_blk->dentry_bitmap,
624	NR_DENTRY_IN_BLOCK,
625	bit_pos);
626	if (bit_pos >= NR_DENTRY_IN_BLOCK)
627	break;
628
629	de = &dentry_blk->dentry[bit_pos];
630	if (types && de->file_type < F2FS_FT_MAX)
631	d_type = types[de->file_type];
632
633	over = filldir(dirent,
634	dentry_blk->filename[bit_pos],
635	le16_to_cpu(de->name_len),
636	(n * NR_DENTRY_IN_BLOCK) + bit_pos,
637	le32_to_cpu(de->ino), d_type);
638	if (over) {
639	file->f_pos += bit_pos - start_bit_pos;
640	goto success;
641	}
457d08ee	642	slots = GET_DENTRY_SLOTS(le16_to_cpu(de->name_len));
6b4ea016 JK	643	bit_pos += slots;
	644	}
	645	bit_pos = 0;
	646	file->f_pos = (n + 1) * NR_DENTRY_IN_BLOCK;
	647	kunmap(dentry_page);
	648	f2fs_put_page(dentry_page, 1);
	649	dentry_page = NULL;
	650	}
	651	success:
	652	if (dentry_page && !IS_ERR(dentry_page)) {
	653	kunmap(dentry_page);
	654	f2fs_put_page(dentry_page, 1);
	655	}
	656
	657	return 0;
	658	}
	659
	660	const struct file_operations f2fs_dir_operations = {
	661	.llseek = generic_file_llseek,
	662	.read = generic_read_dir,
	663	.readdir = f2fs_readdir,
	664	.fsync = f2fs_sync_file,
	665	.unlocked_ioctl = f2fs_ioctl,
	666	};