[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 "node.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)
{
	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;

	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 (namelen > F2FS_NAME_LEN)
		return NULL;

	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)
{
	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);

	/* update parent inode number before releasing dentry page */
	F2FS_I(inode)->i_pino = dir->i_ino;

	f2fs_put_page(page, 1);
}

void init_dent_inode(const struct qstr *name, struct page *ipage)
{
	struct f2fs_node *rn;

	if (IS_ERR(ipage))
		return;

	wait_on_page_writeback(ipage);

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

static int make_empty_dir(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, NULL, 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 int init_inode_metadata(struct inode *inode,
		struct inode *dir, const struct qstr *name)
{
	if (is_inode_flag_set(F2FS_I(inode), FI_NEW_INODE)) {
		int err;
		err = new_inode_page(inode, name);
		if (err)
			return err;

		if (S_ISDIR(inode->i_mode)) {
			err = make_empty_dir(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);
		set_cold_node(inode, ipage);
		init_dent_inode(name, ipage);
		f2fs_put_page(ipage, 1);
	}
	if (is_inode_flag_set(F2FS_I(inode), FI_INC_LINK)) {
		inc_nlink(inode);
		update_inode_page(inode);
	}
	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)
		update_inode_page(dir);
	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;
}

/*
 * Caller should grab and release a mutex by calling mutex_lock_op() and
 * mutex_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);
	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 (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:
	err = init_inode_metadata(inode, dir, name);
	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->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);

	update_parent_metadata(dir, inode, current_depth);

	/* update parent inode number before releasing dentry page */
	F2FS_I(inode)->i_pino = dir->i_ino;
fail:
	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 && S_ISDIR(inode->i_mode)) {
		drop_nlink(dir);
		update_inode_page(dir);
	} else {
		mark_inode_dirty(dir);
	}

	if (inode) {
		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);
	}

	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, void *dirent, filldir_t filldir)
{
	unsigned long pos = file->f_pos;
	struct inode *inode = file_inode(file);
	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"
398b1ac5	14	#include "node.h"
6b4ea016 JK	15	#include "acl.h"
	16
	17	static unsigned long dir_blocks(struct inode *inode)
	18	{
	19	return ((unsigned long long) (i_size_read(inode) + PAGE_CACHE_SIZE - 1))
	20	>> PAGE_CACHE_SHIFT;
	21	}
	22
	23	static unsigned int dir_buckets(unsigned int level)
	24	{
	25	if (level < MAX_DIR_HASH_DEPTH / 2)
	26	return 1 << level;
	27	else
	28	return 1 << ((MAX_DIR_HASH_DEPTH / 2) - 1);
	29	}
	30
	31	static unsigned int bucket_blocks(unsigned int level)
	32	{
	33	if (level < MAX_DIR_HASH_DEPTH / 2)
	34	return 2;
	35	else
	36	return 4;
	37	}
	38
	39	static unsigned char f2fs_filetype_table[F2FS_FT_MAX] = {
	40	[F2FS_FT_UNKNOWN] = DT_UNKNOWN,
	41	[F2FS_FT_REG_FILE] = DT_REG,
	42	[F2FS_FT_DIR] = DT_DIR,
	43	[F2FS_FT_CHRDEV] = DT_CHR,
	44	[F2FS_FT_BLKDEV] = DT_BLK,
	45	[F2FS_FT_FIFO] = DT_FIFO,
	46	[F2FS_FT_SOCK] = DT_SOCK,
	47	[F2FS_FT_SYMLINK] = DT_LNK,
	48	};
	49
	50	#define S_SHIFT 12
	51	static unsigned char f2fs_type_by_mode[S_IFMT >> S_SHIFT] = {
	52	[S_IFREG >> S_SHIFT] = F2FS_FT_REG_FILE,
	53	[S_IFDIR >> S_SHIFT] = F2FS_FT_DIR,
	54	[S_IFCHR >> S_SHIFT] = F2FS_FT_CHRDEV,
	55	[S_IFBLK >> S_SHIFT] = F2FS_FT_BLKDEV,
	56	[S_IFIFO >> S_SHIFT] = F2FS_FT_FIFO,
	57	[S_IFSOCK >> S_SHIFT] = F2FS_FT_SOCK,
	58	[S_IFLNK >> S_SHIFT] = F2FS_FT_SYMLINK,
	59	};
	60
	61	static void set_de_type(struct f2fs_dir_entry de, struct inode inode)
	62	{
0ecc833b	63	umode_t mode = inode->i_mode;
6b4ea016 JK	64	de->file_type = f2fs_type_by_mode[(mode & S_IFMT) >> S_SHIFT];
	65	}
	66
	67	static unsigned long dir_block_index(unsigned int level, unsigned int idx)
	68	{
	69	unsigned long i;
	70	unsigned long bidx = 0;
	71
	72	for (i = 0; i < level; i++)
	73	bidx += dir_buckets(i) * bucket_blocks(i);
	74	bidx += idx * bucket_blocks(level);
	75	return bidx;
	76	}
	77
9836b8b9	78	static bool early_match_name(const char *name, size_t namelen,
6b4ea016 JK	79	f2fs_hash_t namehash, struct f2fs_dir_entry *de)
	80	{
	81	if (le16_to_cpu(de->name_len) != namelen)
	82	return false;
	83
25ca923b	84	if (de->hash_code != namehash)
6b4ea016 JK	85	return false;
	86
	87	return true;
	88	}
	89
	90	static struct f2fs_dir_entry find_in_block(struct page dentry_page,
9836b8b9	91	const char name, size_t namelen, int max_slots,
6b4ea016 JK	92	f2fs_hash_t namehash, struct page **res_page)
	93	{
	94	struct f2fs_dir_entry *de;
	95	unsigned long bit_pos, end_pos, next_pos;
	96	struct f2fs_dentry_block *dentry_blk = kmap(dentry_page);
	97	int slots;
	98
	99	bit_pos = find_next_bit_le(&dentry_blk->dentry_bitmap,
	100	NR_DENTRY_IN_BLOCK, 0);
	101	while (bit_pos < NR_DENTRY_IN_BLOCK) {
	102	de = &dentry_blk->dentry[bit_pos];
457d08ee	103	slots = GET_DENTRY_SLOTS(le16_to_cpu(de->name_len));
6b4ea016 JK	104
	105	if (early_match_name(name, namelen, namehash, de)) {
	106	if (!memcmp(dentry_blk->filename[bit_pos],
	107	name, namelen)) {
	108	*res_page = dentry_page;
	109	goto found;
	110	}
	111	}
	112	next_pos = bit_pos + slots;
	113	bit_pos = find_next_bit_le(&dentry_blk->dentry_bitmap,
	114	NR_DENTRY_IN_BLOCK, next_pos);
	115	if (bit_pos >= NR_DENTRY_IN_BLOCK)
	116	end_pos = NR_DENTRY_IN_BLOCK;
	117	else
	118	end_pos = bit_pos;
	119	if (*max_slots < end_pos - next_pos)
	120	*max_slots = end_pos - next_pos;
	121	}
	122
	123	de = NULL;
	124	kunmap(dentry_page);
	125	found:
	126	return de;
	127	}
	128
	129	static struct f2fs_dir_entry find_in_level(struct inode dir,
9836b8b9	130	unsigned int level, const char *name, size_t namelen,
6b4ea016 JK	131	f2fs_hash_t namehash, struct page **res_page)
6b4ea016 JK	132	{
457d08ee	133	int s = GET_DENTRY_SLOTS(namelen);
6b4ea016 JK	134	unsigned int nbucket, nblock;
	135	unsigned int bidx, end_block;
	136	struct page *dentry_page;
	137	struct f2fs_dir_entry *de = NULL;
	138	bool room = false;
	139	int max_slots = 0;
	140
	141	BUG_ON(level > MAX_DIR_HASH_DEPTH);
	142
	143	nbucket = dir_buckets(level);
	144	nblock = bucket_blocks(level);
	145
25ca923b	146	bidx = dir_block_index(level, le32_to_cpu(namehash) % nbucket);
6b4ea016 JK	147	end_block = bidx + nblock;
	148
	149	for (; bidx < end_block; bidx++) {
	150	/* no need to allocate new dentry pages to all the indices */
c718379b	151	dentry_page = find_data_page(dir, bidx, true);
6b4ea016 JK	152	if (IS_ERR(dentry_page)) {
	153	room = true;
	154	continue;
	155	}
	156
	157	de = find_in_block(dentry_page, name, namelen,
	158	&max_slots, namehash, res_page);
	159	if (de)
	160	break;
	161
	162	if (max_slots >= s)
	163	room = true;
	164	f2fs_put_page(dentry_page, 0);
	165	}
	166
	167	if (!de && room && F2FS_I(dir)->chash != namehash) {
	168	F2FS_I(dir)->chash = namehash;
	169	F2FS_I(dir)->clevel = level;
	170	}
	171
	172	return de;
	173	}
	174
	175	/*
	176	* Find an entry in the specified directory with the wanted name.
	177	* It returns the page where the entry was found (as a parameter - res_page),
	178	* and the entry itself. Page is returned mapped and unlocked.
	179	* Entry is guaranteed to be valid.
	180	*/
	181	struct f2fs_dir_entry f2fs_find_entry(struct inode dir,
	182	struct qstr child, struct page *res_page)
	183	{
	184	const char *name = child->name;
9836b8b9	185	size_t namelen = child->len;
6b4ea016 JK	186	unsigned long npages = dir_blocks(dir);
	187	struct f2fs_dir_entry *de = NULL;
	188	f2fs_hash_t name_hash;
	189	unsigned int max_depth;
	190	unsigned int level;
	191
5a20d339 JK	192	if (namelen > F2FS_NAME_LEN)
	193	return NULL;
	194
6b4ea016 JK	195	if (npages == 0)
	196	return NULL;
	197
	198	*res_page = NULL;
	199
	200	name_hash = f2fs_dentry_hash(name, namelen);
	201	max_depth = F2FS_I(dir)->i_current_depth;
	202
	203	for (level = 0; level < max_depth; level++) {
	204	de = find_in_level(dir, level, name,
	205	namelen, name_hash, res_page);
	206	if (de)
	207	break;
	208	}
	209	if (!de && F2FS_I(dir)->chash != name_hash) {
	210	F2FS_I(dir)->chash = name_hash;
	211	F2FS_I(dir)->clevel = level - 1;
	212	}
	213	return de;
	214	}
	215
	216	struct f2fs_dir_entry f2fs_parent_dir(struct inode dir, struct page **p)
	217	{
	218	struct page *page = NULL;
	219	struct f2fs_dir_entry *de = NULL;
	220	struct f2fs_dentry_block *dentry_blk = NULL;
	221
	222	page = get_lock_data_page(dir, 0);
	223	if (IS_ERR(page))
	224	return NULL;
	225
	226	dentry_blk = kmap(page);
	227	de = &dentry_blk->dentry[1];
	228	*p = page;
	229	unlock_page(page);
	230	return de;
	231	}
	232
	233	ino_t f2fs_inode_by_name(struct inode dir, struct qstr qstr)
	234	{
	235	ino_t res = 0;
	236	struct f2fs_dir_entry *de;
	237	struct page *page;
	238
	239	de = f2fs_find_entry(dir, qstr, &page);
	240	if (de) {
	241	res = le32_to_cpu(de->ino);
	242	kunmap(page);
	243	f2fs_put_page(page, 0);
	244	}
	245
	246	return res;
	247	}
	248
	249	void f2fs_set_link(struct inode dir, struct f2fs_dir_entry de,
	250	struct page page, struct inode inode)
	251	{
6b4ea016 JK	252	lock_page(page);
	253	wait_on_page_writeback(page);
	254	de->ino = cpu_to_le32(inode->i_ino);
	255	set_de_type(de, inode);
	256	kunmap(page);
	257	set_page_dirty(page);
	258	dir->i_mtime = dir->i_ctime = CURRENT_TIME;
	259	mark_inode_dirty(dir);
6666e6aa JK	260
	261	/* update parent inode number before releasing dentry page */
	262	F2FS_I(inode)->i_pino = dir->i_ino;
	263
6b4ea016	264	f2fs_put_page(page, 1);
6b4ea016 JK	265	}
6b4ea016 JK	266
53dc9a67	267	void init_dent_inode(const struct qstr name, struct page ipage)
6b4ea016	268	{
6b4ea016 JK	269	struct f2fs_node *rn;
	270
	271	if (IS_ERR(ipage))
	272	return;
	273
	274	wait_on_page_writeback(ipage);
	275
53dc9a67	276	/* copy name info. to this inode page */
6b4ea016	277	rn = (struct f2fs_node *)page_address(ipage);
53dc9a67 AV	278	rn->i.i_namelen = cpu_to_le32(name->len);
53dc9a67 AV	279	memcpy(rn->i.i_name, name->name, name->len);
6b4ea016 JK	280	set_page_dirty(ipage);
	281	}
	282
39936837 JK	283	static int make_empty_dir(struct inode inode, struct inode parent)
	284	{
	285	struct page *dentry_page;
	286	struct f2fs_dentry_block *dentry_blk;
	287	struct f2fs_dir_entry *de;
	288	void *kaddr;
	289
64aa7ed9	290	dentry_page = get_new_data_page(inode, NULL, 0, true);
39936837 JK	291	if (IS_ERR(dentry_page))
	292	return PTR_ERR(dentry_page);
	293
	294	kaddr = kmap_atomic(dentry_page);
	295	dentry_blk = (struct f2fs_dentry_block *)kaddr;
	296
	297	de = &dentry_blk->dentry[0];
	298	de->name_len = cpu_to_le16(1);
	299	de->hash_code = 0;
	300	de->ino = cpu_to_le32(inode->i_ino);
	301	memcpy(dentry_blk->filename[0], ".", 1);
	302	set_de_type(de, inode);
	303
	304	de = &dentry_blk->dentry[1];
	305	de->hash_code = 0;
	306	de->name_len = cpu_to_le16(2);
	307	de->ino = cpu_to_le32(parent->i_ino);
	308	memcpy(dentry_blk->filename[1], "..", 2);
	309	set_de_type(de, inode);
	310
	311	test_and_set_bit_le(0, &dentry_blk->dentry_bitmap);
	312	test_and_set_bit_le(1, &dentry_blk->dentry_bitmap);
	313	kunmap_atomic(kaddr);
	314
	315	set_page_dirty(dentry_page);
	316	f2fs_put_page(dentry_page, 1);
	317	return 0;
	318	}
	319
69f24eac AV	320	static int init_inode_metadata(struct inode *inode,
69f24eac AV	321	struct inode dir, const struct qstr name)
6b4ea016	322	{
6b4ea016 JK	323	if (is_inode_flag_set(F2FS_I(inode), FI_NEW_INODE)) {
6b4ea016 JK	324	int err;
69f24eac	325	err = new_inode_page(inode, name);
6b4ea016 JK	326	if (err)
	327	return err;
	328
	329	if (S_ISDIR(inode->i_mode)) {
39936837	330	err = make_empty_dir(inode, dir);
6b4ea016 JK	331	if (err) {
	332	remove_inode_page(inode);
	333	return err;
	334	}
	335	}
	336
	337	err = f2fs_init_acl(inode, dir);
	338	if (err) {
	339	remove_inode_page(inode);
	340	return err;
	341	}
	342	} else {
	343	struct page *ipage;
	344	ipage = get_node_page(F2FS_SB(dir->i_sb), inode->i_ino);
	345	if (IS_ERR(ipage))
	346	return PTR_ERR(ipage);
398b1ac5	347	set_cold_node(inode, ipage);
69f24eac	348	init_dent_inode(name, ipage);
6b4ea016 JK	349	f2fs_put_page(ipage, 1);
	350	}
	351	if (is_inode_flag_set(F2FS_I(inode), FI_INC_LINK)) {
	352	inc_nlink(inode);
39936837	353	update_inode_page(inode);
6b4ea016 JK	354	}
	355	return 0;
	356	}
	357
	358	static void update_parent_metadata(struct inode dir, struct inode inode,
	359	unsigned int current_depth)
	360	{
	361	bool need_dir_update = false;
	362
	363	if (is_inode_flag_set(F2FS_I(inode), FI_NEW_INODE)) {
	364	if (S_ISDIR(inode->i_mode)) {
	365	inc_nlink(dir);
	366	need_dir_update = true;
	367	}
	368	clear_inode_flag(F2FS_I(inode), FI_NEW_INODE);
	369	}
	370	dir->i_mtime = dir->i_ctime = CURRENT_TIME;
	371	if (F2FS_I(dir)->i_current_depth != current_depth) {
	372	F2FS_I(dir)->i_current_depth = current_depth;
	373	need_dir_update = true;
	374	}
	375
	376	if (need_dir_update)
39936837	377	update_inode_page(dir);
6b4ea016 JK	378	else
	379	mark_inode_dirty(dir);
	380
	381	if (is_inode_flag_set(F2FS_I(inode), FI_INC_LINK))
	382	clear_inode_flag(F2FS_I(inode), FI_INC_LINK);
	383	}
	384
	385	static int room_for_filename(struct f2fs_dentry_block *dentry_blk, int slots)
	386	{
	387	int bit_start = 0;
	388	int zero_start, zero_end;
	389	next:
	390	zero_start = find_next_zero_bit_le(&dentry_blk->dentry_bitmap,
	391	NR_DENTRY_IN_BLOCK,
	392	bit_start);
	393	if (zero_start >= NR_DENTRY_IN_BLOCK)
	394	return NR_DENTRY_IN_BLOCK;
	395
	396	zero_end = find_next_bit_le(&dentry_blk->dentry_bitmap,
	397	NR_DENTRY_IN_BLOCK,
	398	zero_start);
	399	if (zero_end - zero_start >= slots)
	400	return zero_start;
	401
	402	bit_start = zero_end + 1;
	403
	404	if (zero_end + 1 >= NR_DENTRY_IN_BLOCK)
	405	return NR_DENTRY_IN_BLOCK;
	406	goto next;
	407	}
	408
39936837 JK	409	/*
	410	* Caller should grab and release a mutex by calling mutex_lock_op() and
	411	* mutex_unlock_op().
	412	*/
b7f7a5e0	413	int __f2fs_add_link(struct inode dir, const struct qstr name, struct inode *inode)
6b4ea016 JK	414	{
	415	unsigned int bit_pos;
	416	unsigned int level;
	417	unsigned int current_depth;
	418	unsigned long bidx, block;
	419	f2fs_hash_t dentry_hash;
	420	struct f2fs_dir_entry *de;
	421	unsigned int nbucket, nblock;
b7f7a5e0	422	size_t namelen = name->len;
6b4ea016 JK	423	struct page *dentry_page = NULL;
6b4ea016 JK	424	struct f2fs_dentry_block *dentry_blk = NULL;
457d08ee	425	int slots = GET_DENTRY_SLOTS(namelen);
6b4ea016 JK	426	int err = 0;
	427	int i;
	428
b7f7a5e0	429	dentry_hash = f2fs_dentry_hash(name->name, name->len);
6b4ea016 JK	430	level = 0;
	431	current_depth = F2FS_I(dir)->i_current_depth;
	432	if (F2FS_I(dir)->chash == dentry_hash) {
	433	level = F2FS_I(dir)->clevel;
	434	F2FS_I(dir)->chash = 0;
	435	}
	436
	437	start:
	438	if (current_depth == MAX_DIR_HASH_DEPTH)
	439	return -ENOSPC;
	440
	441	/* Increase the depth, if required */
	442	if (level == current_depth)
	443	++current_depth;
	444
	445	nbucket = dir_buckets(level);
	446	nblock = bucket_blocks(level);
	447
25ca923b	448	bidx = dir_block_index(level, (le32_to_cpu(dentry_hash) % nbucket));
6b4ea016 JK	449
6b4ea016 JK	450	for (block = bidx; block <= (bidx + nblock - 1); block++) {
64aa7ed9	451	dentry_page = get_new_data_page(dir, NULL, block, true);
39936837	452	if (IS_ERR(dentry_page))
6b4ea016	453	return PTR_ERR(dentry_page);
6b4ea016 JK	454
	455	dentry_blk = kmap(dentry_page);
	456	bit_pos = room_for_filename(dentry_blk, slots);
	457	if (bit_pos < NR_DENTRY_IN_BLOCK)
	458	goto add_dentry;
	459
	460	kunmap(dentry_page);
	461	f2fs_put_page(dentry_page, 1);
6b4ea016 JK	462	}
	463
	464	/* Move to next level to find the empty slot for new dentry */
	465	++level;
	466	goto start;
	467	add_dentry:
b7f7a5e0	468	err = init_inode_metadata(inode, dir, name);
6b4ea016 JK	469	if (err)
	470	goto fail;
	471
	472	wait_on_page_writeback(dentry_page);
	473
	474	de = &dentry_blk->dentry[bit_pos];
25ca923b	475	de->hash_code = dentry_hash;
6b4ea016	476	de->name_len = cpu_to_le16(namelen);
b7f7a5e0	477	memcpy(dentry_blk->filename[bit_pos], name->name, name->len);
6b4ea016 JK	478	de->ino = cpu_to_le32(inode->i_ino);
	479	set_de_type(de, inode);
	480	for (i = 0; i < slots; i++)
	481	test_and_set_bit_le(bit_pos + i, &dentry_blk->dentry_bitmap);
	482	set_page_dirty(dentry_page);
6666e6aa	483
6b4ea016	484	update_parent_metadata(dir, inode, current_depth);
6666e6aa JK	485
	486	/* update parent inode number before releasing dentry page */
	487	F2FS_I(inode)->i_pino = dir->i_ino;
6b4ea016 JK	488	fail:
	489	kunmap(dentry_page);
	490	f2fs_put_page(dentry_page, 1);
6b4ea016 JK	491	return err;
	492	}
	493
0a8165d7	494	/*
6b4ea016 JK	495	* It only removes the dentry from the dentry page,corresponding name
	496	* entry in name page does not need to be touched during deletion.
	497	*/
	498	void f2fs_delete_entry(struct f2fs_dir_entry dentry, struct page page,
	499	struct inode *inode)
	500	{
	501	struct f2fs_dentry_block *dentry_blk;
	502	unsigned int bit_pos;
	503	struct address_space *mapping = page->mapping;
	504	struct inode *dir = mapping->host;
	505	struct f2fs_sb_info *sbi = F2FS_SB(dir->i_sb);
457d08ee	506	int slots = GET_DENTRY_SLOTS(le16_to_cpu(dentry->name_len));
6b4ea016 JK	507	void *kaddr = page_address(page);
	508	int i;
	509
6b4ea016 JK	510	lock_page(page);
	511	wait_on_page_writeback(page);
	512
	513	dentry_blk = (struct f2fs_dentry_block *)kaddr;
	514	bit_pos = dentry - (struct f2fs_dir_entry *)dentry_blk->dentry;
	515	for (i = 0; i < slots; i++)
	516	test_and_clear_bit_le(bit_pos + i, &dentry_blk->dentry_bitmap);
	517
	518	/* Let's check and deallocate this dentry page */
	519	bit_pos = find_next_bit_le(&dentry_blk->dentry_bitmap,
	520	NR_DENTRY_IN_BLOCK,
	521	0);
	522	kunmap(page); /* kunmap - pair of f2fs_find_entry */
	523	set_page_dirty(page);
	524
	525	dir->i_ctime = dir->i_mtime = CURRENT_TIME;
	526
	527	if (inode && S_ISDIR(inode->i_mode)) {
	528	drop_nlink(dir);
39936837	529	update_inode_page(dir);
6b4ea016 JK	530	} else {
	531	mark_inode_dirty(dir);
	532	}
	533
	534	if (inode) {
16379987	535	inode->i_ctime = CURRENT_TIME;
6b4ea016 JK	536	drop_nlink(inode);
	537	if (S_ISDIR(inode->i_mode)) {
	538	drop_nlink(inode);
	539	i_size_write(inode, 0);
	540	}
39936837 JK	541	update_inode_page(inode);
39936837 JK	542
6b4ea016 JK	543	if (inode->i_nlink == 0)
	544	add_orphan_inode(sbi, inode->i_ino);
	545	}
	546
	547	if (bit_pos == NR_DENTRY_IN_BLOCK) {
6b4ea016 JK	548	truncate_hole(dir, page->index, page->index + 1);
	549	clear_page_dirty_for_io(page);
	550	ClearPageUptodate(page);
	551	dec_page_count(sbi, F2FS_DIRTY_DENTS);
	552	inode_dec_dirty_dents(dir);
6b4ea016	553	}
508198be	554	f2fs_put_page(page, 1);
6b4ea016 JK	555	}
	556
	557	bool f2fs_empty_dir(struct inode *dir)
	558	{
	559	unsigned long bidx;
	560	struct page *dentry_page;
	561	unsigned int bit_pos;
	562	struct f2fs_dentry_block *dentry_blk;
	563	unsigned long nblock = dir_blocks(dir);
	564
	565	for (bidx = 0; bidx < nblock; bidx++) {
	566	void *kaddr;
	567	dentry_page = get_lock_data_page(dir, bidx);
	568	if (IS_ERR(dentry_page)) {
	569	if (PTR_ERR(dentry_page) == -ENOENT)
	570	continue;
	571	else
	572	return false;
	573	}
	574
	575	kaddr = kmap_atomic(dentry_page);
	576	dentry_blk = (struct f2fs_dentry_block *)kaddr;
	577	if (bidx == 0)
	578	bit_pos = 2;
	579	else
	580	bit_pos = 0;
	581	bit_pos = find_next_bit_le(&dentry_blk->dentry_bitmap,
	582	NR_DENTRY_IN_BLOCK,
	583	bit_pos);
	584	kunmap_atomic(kaddr);
	585
	586	f2fs_put_page(dentry_page, 1);
	587
	588	if (bit_pos < NR_DENTRY_IN_BLOCK)
	589	return false;
	590	}
	591	return true;
	592	}
	593
	594	static int f2fs_readdir(struct file file, void dirent, filldir_t filldir)
	595	{
	596	unsigned long pos = file->f_pos;
496ad9aa	597	struct inode *inode = file_inode(file);
6b4ea016 JK	598	unsigned long npages = dir_blocks(inode);
	599	unsigned char *types = NULL;
	600	unsigned int bit_pos = 0, start_bit_pos = 0;
	601	int over = 0;
	602	struct f2fs_dentry_block *dentry_blk = NULL;
	603	struct f2fs_dir_entry *de = NULL;
	604	struct page *dentry_page = NULL;
	605	unsigned int n = 0;
	606	unsigned char d_type = DT_UNKNOWN;
	607	int slots;
	608
	609	types = f2fs_filetype_table;
	610	bit_pos = (pos % NR_DENTRY_IN_BLOCK);
	611	n = (pos / NR_DENTRY_IN_BLOCK);
	612
	613	for ( ; n < npages; n++) {
	614	dentry_page = get_lock_data_page(inode, n);
	615	if (IS_ERR(dentry_page))
	616	continue;
	617
	618	start_bit_pos = bit_pos;
	619	dentry_blk = kmap(dentry_page);
	620	while (bit_pos < NR_DENTRY_IN_BLOCK) {
	621	d_type = DT_UNKNOWN;
	622	bit_pos = find_next_bit_le(&dentry_blk->dentry_bitmap,
	623	NR_DENTRY_IN_BLOCK,
	624	bit_pos);
	625	if (bit_pos >= NR_DENTRY_IN_BLOCK)
	626	break;
	627
	628	de = &dentry_blk->dentry[bit_pos];
	629	if (types && de->file_type < F2FS_FT_MAX)
	630	d_type = types[de->file_type];
	631
	632	over = filldir(dirent,
	633	dentry_blk->filename[bit_pos],
	634	le16_to_cpu(de->name_len),
	635	(n * NR_DENTRY_IN_BLOCK) + bit_pos,
	636	le32_to_cpu(de->ino), d_type);
	637	if (over) {
	638	file->f_pos += bit_pos - start_bit_pos;
	639	goto success;
	640	}
457d08ee	641	slots = GET_DENTRY_SLOTS(le16_to_cpu(de->name_len));
6b4ea016 JK	642	bit_pos += slots;
	643	}
	644	bit_pos = 0;
	645	file->f_pos = (n + 1) * NR_DENTRY_IN_BLOCK;
	646	kunmap(dentry_page);
	647	f2fs_put_page(dentry_page, 1);
	648	dentry_page = NULL;
	649	}
	650	success:
	651	if (dentry_page && !IS_ERR(dentry_page)) {
	652	kunmap(dentry_page);
	653	f2fs_put_page(dentry_page, 1);
	654	}
	655
	656	return 0;
	657	}
	658
	659	const struct file_operations f2fs_dir_operations = {
	660	.llseek = generic_file_llseek,
	661	.read = generic_read_dir,
	662	.readdir = f2fs_readdir,
	663	.fsync = f2fs_sync_file,
	664	.unlocked_ioctl = f2fs_ioctl,
	665	};