struct inode * sysv_new_inode(const struct inode * dir, mode_t mode)
{
	struct super_block *sb = dir->i_sb;
	struct sysv_sb_info *sbi = SYSV_SB(sb);
	struct inode *inode;
	u16 ino;
	unsigned count;

	inode = new_inode(sb);
	if (!inode)
		return ERR_PTR(-ENOMEM);

	lock_super(sb);
	count = fs16_to_cpu(sbi, *sbi->s_sb_fic_count);
	if (count == 0 || (*sv_sb_fic_inode(sb,count-1) == 0)) {
		count = refill_free_cache(sb);
		if (count == 0) {
			iput(inode);
			unlock_super(sb);
			return ERR_PTR(-ENOSPC);
		}
	}
	/* Now count > 0. */
	ino = *sv_sb_fic_inode(sb,--count);
	*sbi->s_sb_fic_count = cpu_to_fs16(sbi, count);
	fs16_add(sbi, sbi->s_sb_total_free_inodes, -1);
	dirty_sb(sb);
	
	if (dir->i_mode & S_ISGID) {
		inode->i_gid = dir->i_gid;
		if (S_ISDIR(mode))
			mode |= S_ISGID;
	} else
		inode->i_gid = current->fsgid;

	inode->i_uid = current->fsuid;
	inode->i_ino = fs16_to_cpu(sbi, ino);
	inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
	inode->i_blocks = inode->i_blksize = 0;
	memset(SYSV_I(inode)->i_data, 0, sizeof(SYSV_I(inode)->i_data));
	SYSV_I(inode)->i_dir_start_lookup = 0;
	insert_inode_hash(inode);
	mark_inode_dirty(inode);

	inode->i_mode = mode;		/* for sysv_write_inode() */
	sysv_write_inode(inode, 0);	/* ensure inode not allocated again */
	mark_inode_dirty(inode);	/* cleared by sysv_write_inode() */
	/* That's it. */
	unlock_super(sb);
	return inode;
}
void sysv_free_inode(struct inode * inode)
{
	struct super_block *sb = inode->i_sb;
	struct sysv_sb_info *sbi = SYSV_SB(sb);
	unsigned int ino;
	struct buffer_head * bh;
	struct sysv_inode * raw_inode;
	unsigned count;

	sb = inode->i_sb;
	ino = inode->i_ino;
	if (ino <= SYSV_ROOT_INO || ino > sbi->s_ninodes) {
		printk("sysv_free_inode: inode 0,1,2 or nonexistent inode\n");
		return;
	}
	raw_inode = sysv_raw_inode(sb, ino, &bh);
	if (!raw_inode) {
		printk("sysv_free_inode: unable to read inode block on device "
		       "%s\n", inode->i_sb->s_id);
		return;
	}
	lock_super(sb);
	count = fs16_to_cpu(sbi, *sbi->s_sb_fic_count);
	if (count < sbi->s_fic_size) {
		*sv_sb_fic_inode(sb,count++) = cpu_to_fs16(sbi, ino);
		*sbi->s_sb_fic_count = cpu_to_fs16(sbi, count);
	}
	fs16_add(sbi, sbi->s_sb_total_free_inodes, 1);
	dirty_sb(sb);
	memset(raw_inode, 0, sizeof(struct sysv_inode));
	mark_buffer_dirty(bh);
	unlock_super(sb);
	brelse(bh);
}
static int refill_free_cache(struct super_block *sb)
{
	struct sysv_sb_info *sbi = SYSV_SB(sb);
	struct buffer_head * bh;
	struct sysv_inode * raw_inode;
	int i = 0, ino;

	ino = SYSV_ROOT_INO+1;
	raw_inode = sysv_raw_inode(sb, ino, &bh);
	if (!raw_inode)
		goto out;
	while (ino <= sbi->s_ninodes) {
		if (raw_inode->i_mode == 0 && raw_inode->i_nlink == 0) {
			*sv_sb_fic_inode(sb,i++) = cpu_to_fs16(SYSV_SB(sb), ino);
			if (i == sbi->s_fic_size)
				break;
		}
		if ((ino++ & sbi->s_inodes_per_block_1) == 0) {
			brelse(bh);
			raw_inode = sysv_raw_inode(sb, ino, &bh);
			if (!raw_inode)
				goto out;
		} else
			raw_inode++;
	}
	brelse(bh);
out:
	return i;
}
struct inode * sysv_new_inode(const struct inode * dir, umode_t mode)
{
	struct super_block *sb = dir->i_sb;
	struct sysv_sb_info *sbi = SYSV_SB(sb);
	struct inode *inode;
	sysv_ino_t ino;
	unsigned count;
	struct writeback_control wbc = {
		.sync_mode = WB_SYNC_NONE
	};

	inode = new_inode(sb);
	if (!inode)
		return ERR_PTR(-ENOMEM);

	lock_super(sb);
	count = fs16_to_cpu(sbi, *sbi->s_sb_fic_count);
	if (count == 0 || (*sv_sb_fic_inode(sb,count-1) == 0)) {
		count = refill_free_cache(sb);
		if (count == 0) {
			iput(inode);
			unlock_super(sb);
			return ERR_PTR(-ENOSPC);
		}
	}
	/* Now count > 0. */
	ino = *sv_sb_fic_inode(sb,--count);
	*sbi->s_sb_fic_count = cpu_to_fs16(sbi, count);
	fs16_add(sbi, sbi->s_sb_total_free_inodes, -1);
	dirty_sb(sb);
	inode_init_owner(inode, dir, mode);
	inode->i_ino = fs16_to_cpu(sbi, ino);
	inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME_SEC;
	inode->i_blocks = 0;
	memset(SYSV_I(inode)->i_data, 0, sizeof(SYSV_I(inode)->i_data));
	SYSV_I(inode)->i_dir_start_lookup = 0;
	insert_inode_hash(inode);
	mark_inode_dirty(inode);

	sysv_write_inode(inode, &wbc);	/* ensure inode not allocated again */
	mark_inode_dirty(inode);	/* cleared by sysv_write_inode() */
	/* That's it. */
	unlock_super(sb);
	return inode;
}