path: root/fs/f2fs/f2fs.h

/*
 * fs/f2fs/f2fs.h
 *
 * 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.
 */
#ifndef _LINUX_F2FS_H
#define _LINUX_F2FS_H

#include <linux/types.h>
#include <linux/page-flags.h>
#include <linux/buffer_head.h>
#include <linux/slab.h>
#include <linux/crc32.h>
#include <linux/magic.h>
#include <linux/kobject.h>
#include <linux/sched.h>

#ifdef CONFIG_F2FS_CHECK_FS
#define f2fs_bug_on(condition)	BUG_ON(condition)
#else
#define f2fs_bug_on(condition)
#endif

/*
 * For mount options
 */
#define F2FS_MOUNT_BG_GC		0x00000001
#define F2FS_MOUNT_DISABLE_ROLL_FORWARD	0x00000002
#define F2FS_MOUNT_DISCARD		0x00000004
#define F2FS_MOUNT_NOHEAP		0x00000008
#define F2FS_MOUNT_XATTR_USER		0x00000010
#define F2FS_MOUNT_POSIX_ACL		0x00000020
#define F2FS_MOUNT_DISABLE_EXT_IDENTIFY	0x00000040
#define F2FS_MOUNT_INLINE_XATTR		0x00000080

#define clear_opt(sbi, option)	(sbi->mount_opt.opt &= ~F2FS_MOUNT_##option)
#define set_opt(sbi, option)	(sbi->mount_opt.opt |= F2FS_MOUNT_##option)
#define test_opt(sbi, option)	(sbi->mount_opt.opt & F2FS_MOUNT_##option)

#define ver_after(a, b)	(typecheck(unsigned long long, a) &&		\
		typecheck(unsigned long long, b) &&			\
		((long long)((a) - (b)) > 0))

typedef u32 block_t;	/*
			 * should not change u32, since it is the on-disk block
			 * address format, __le32.
			 */
typedef u32 nid_t;

struct f2fs_mount_info {
	unsigned int	opt;
};

#define CRCPOLY_LE 0xedb88320

static inline __u32 f2fs_crc32(void *buf, size_t len)
{
	unsigned char *p = (unsigned char *)buf;
	__u32 crc = F2FS_SUPER_MAGIC;
	int i;

	while (len--) {
		crc ^= *p++;
		for (i = 0; i < 8; i++)
			crc = (crc >> 1) ^ ((crc & 1) ? CRCPOLY_LE : 0);
	}
	return crc;
}

static inline bool f2fs_crc_valid(__u32 blk_crc, void *buf, size_t buf_size)
{
	return f2fs_crc32(buf, buf_size) == blk_crc;
}

/*
 * For checkpoint manager
 */
enum {
	NAT_BITMAP,
	SIT_BITMAP
};

/* for the list of orphan inodes */
struct orphan_inode_entry {
	struct list_head list;	/* list head */
	nid_t ino;		/* inode number */
};

/* for the list of directory inodes */
struct dir_inode_entry {
	struct list_head list;	/* list head */
	struct inode *inode;	/* vfs inode pointer */
};

/* for the list of blockaddresses to be discarded */
struct discard_entry {
	struct list_head list;	/* list head */
	block_t blkaddr;	/* block address to be discarded */
	int len;		/* # of consecutive blocks of the discard */
};

/* for the list of fsync inodes, used only during recovery */
struct fsync_inode_entry {
	struct list_head list;	/* list head */
	struct inode *inode;	/* vfs inode pointer */
	block_t blkaddr;	/* block address locating the last inode */
};

#define nats_in_cursum(sum)		(le16_to_cpu(sum->n_nats))
#define sits_in_cursum(sum)		(le16_to_cpu(sum->n_sits))

#define nat_in_journal(sum, i)		(sum->nat_j.entries[i].ne)
#define nid_in_journal(sum, i)		(sum->nat_j.entries[i].nid)
#define sit_in_journal(sum, i)		(sum->sit_j.entries[i].se)
#define segno_in_journal(sum, i)	(sum->sit_j.entries[i].segno)

static inline int update_nats_in_cursum(struct f2fs_summary_block *rs, int i)
{
	int before = nats_in_cursum(rs);
	rs->n_nats = cpu_to_le16(before + i);
	return before