C++ HFSPLUS_SB函数代码示例

int hfsplus_show_options(struct seq_file *seq, struct vfsmount *mnt)
#endif
{
#if LINUX_VERSION_CODE >= KERNEL_VERSION(3,5,0)
	struct hfsplus_sb_info *sbi = HFSPLUS_SB(root->d_sb);
#else
	struct hfsplus_sb_info *sbi = HFSPLUS_SB(mnt->mnt_sb);
#endif
	if (sbi->creator != HFSPLUS_DEF_CR_TYPE)
		seq_printf(seq, ",creator=%.4s", (char *)&sbi->creator);
	if (sbi->type != HFSPLUS_DEF_CR_TYPE)
		seq_printf(seq, ",type=%.4s", (char *)&sbi->type);
	seq_printf(seq, ",umask=%o,uid=%u,gid=%u", sbi->umask,
#if LINUX_VERSION_CODE >= KERNEL_VERSION(3,7,0)
			from_kuid_munged(&init_user_ns, sbi->uid),
			from_kgid_munged(&init_user_ns, sbi->gid));
#else
			sbi->uid, sbi->gid);
#endif
	if (sbi->part >= 0)
		seq_printf(seq, ",part=%u", sbi->part);
	if (sbi->session >= 0)
		seq_printf(seq, ",session=%u", sbi->session);
	if (sbi->nls)
		seq_printf(seq, ",nls=%s", sbi->nls->charset);
	if (test_bit(HFSPLUS_SB_NODECOMPOSE, &sbi->flags))
		seq_printf(seq, ",nodecompose");
	if (test_bit(HFSPLUS_SB_NOBARRIER, &sbi->flags))
		seq_printf(seq, ",nobarrier");
	return 0;
}

int hfs_part_find(struct super_block *sb,
		  sector_t *part_start, sector_t *part_size)
{
	struct buffer_head *bh;
	__be16 *data;
	int i, size, res;

	res = -ENOENT;
	bh = sb_bread512(sb, *part_start + HFS_PMAP_BLK, data);
	if (!bh)
		return -EIO;

	switch (be16_to_cpu(*data)) {
	case HFS_OLD_PMAP_MAGIC:
	  {
		struct old_pmap *pm;
		struct old_pmap_entry *p;

		pm = (struct old_pmap *)bh->b_data;
		p = pm->pdEntry;
		size = 42;
		for (i = 0; i < size; p++, i++) {
			if (p->pdStart && p->pdSize &&
			    p->pdFSID == cpu_to_be32(0x54465331)/*"TFS1"*/ &&
			    (HFSPLUS_SB(sb).part < 0 || HFSPLUS_SB(sb).part == i)) {
				*part_start += be32_to_cpu(p->pdStart);
				*part_size = be32_to_cpu(p->pdSize);
				res = 0;
			}
		}
		break;
	  }
	case HFS_NEW_PMAP_MAGIC:
	  {
		struct new_pmap *pm;

		pm = (struct new_pmap *)bh->b_data;
		size = be32_to_cpu(pm->pmMapBlkCnt);
		for (i = 0; i < size;) {
			if (!memcmp(pm->pmPartType,"Apple_HFS", 9) &&
			    (HFSPLUS_SB(sb).part < 0 || HFSPLUS_SB(sb).part == i)) {
				*part_start += be32_to_cpu(pm->pmPyPartStart);
				*part_size = be32_to_cpu(pm->pmPartBlkCnt);
				res = 0;
				break;
			}
			brelse(bh);
			bh = sb_bread512(sb, *part_start + HFS_PMAP_BLK + ++i, pm);
			if (!bh)
				return -EIO;
			if (pm->pmSig != cpu_to_be16(HFS_NEW_PMAP_MAGIC))
				break;
		}
		break;
	  }
	}
	brelse(bh);

	return res;
}

static int hfsplus_get_last_session(struct super_block *sb,
                                    sector_t *start, sector_t *size)
{
    struct cdrom_multisession ms_info;
    struct cdrom_tocentry te;
    int res;

    /* default values */
    *start = 0;
    *size = sb->s_bdev->bd_inode->i_size >> 9;

    if (HFSPLUS_SB(sb)->session >= 0) {
        te.cdte_track = HFSPLUS_SB(sb)->session;
        te.cdte_format = CDROM_LBA;
        res = ioctl_by_bdev(sb->s_bdev,
                            CDROMREADTOCENTRY, (unsigned long)&te);
        if (!res && (te.cdte_ctrl & CDROM_DATA_TRACK) == 4) {
            *start = (sector_t)te.cdte_addr.lba << 2;
            return 0;
        }
        pr_err("invalid session number or type of track\n");
        return -EINVAL;
    }
    ms_info.addr_format = CDROM_LBA;
    res = ioctl_by_bdev(sb->s_bdev, CDROMMULTISESSION,
                        (unsigned long)&ms_info);
    if (!res && ms_info.xa_flag)
        *start = (sector_t)ms_info.addr.lba << 2;
    return 0;
}

static int hfsplus_unlink(struct inode *dir, struct dentry *dentry)
{
	struct super_block *sb = dir->i_sb;
	struct inode *inode = dentry->d_inode;
	struct qstr str;
	char name[32];
	u32 cnid;
	int res;
	hfsplus_handle_t hfsplus_handle;

	if (HFSPLUS_IS_RSRC(inode))
		return -EPERM;

	if ((res = hfsplus_journal_start(__FUNCTION__, dir->i_sb, &hfsplus_handle)))
		return res;

	cnid = (u32)(unsigned long)dentry->d_fsdata;
	if (inode->i_ino == cnid &&
	    atomic_read(&HFSPLUS_I(inode).opencnt)) {
		str.name = name;
		str.len = sprintf(name, "temp%lu", inode->i_ino);
		res = hfsplus_rename_cat(&hfsplus_handle, inode->i_ino,
					 dir, &dentry->d_name,
					 HFSPLUS_SB(sb).hidden_dir, &str);
		if (!res)
			inode->i_flags |= S_DEAD;
		hfsplus_journal_stop(&hfsplus_handle);
		return res;
	}
	res = hfsplus_delete_cat(&hfsplus_handle, cnid, dir, &dentry->d_name);
	if (res) {
		hfsplus_journal_stop(&hfsplus_handle);
		return res;
	}
	if (inode->i_nlink > 0)
		drop_nlink(inode);
	if (inode->i_ino == cnid)
		clear_nlink(inode);
	if (!inode->i_nlink) {
		if (inode->i_ino != cnid) {
			HFSPLUS_SB(sb).file_count--;
			if (!atomic_read(&HFSPLUS_I(inode).opencnt)) {
			res = hfsplus_delete_cat(&hfsplus_handle, inode->i_ino, HFSPLUS_SB(sb).hidden_dir, NULL);
				if (!res)
				hfsplus_delete_inode(&hfsplus_handle, inode);
			} else
				inode->i_flags |= S_DEAD;
		} else
			hfsplus_delete_inode(&hfsplus_handle,inode);
	} else
		HFSPLUS_SB(sb).file_count--;
	inode->i_ctime = CURRENT_TIME_SEC;
	res = hfsplus_journalled_mark_inode_dirty(__FUNCTION__, &hfsplus_handle, inode);

	hfsplus_journal_stop(&hfsplus_handle);
	return res;
}

/* Get a block at iblock for inode, possibly allocating if create */
int hfsplus_get_block(struct inode *inode, sector_t iblock,
		      struct buffer_head *bh_result, int create)
{
	struct super_block *sb;
	int res = -EIO;
	u32 ablock, dblock, mask;
	int shift;

	sb = inode->i_sb;

	/* Convert inode block to disk allocation block */
	shift = HFSPLUS_SB(sb).alloc_blksz_shift - sb->s_blocksize_bits;
	ablock = iblock >> HFSPLUS_SB(sb).fs_shift;

	if (iblock >= inode->i_blocks) {
		if (iblock > inode->i_blocks || !create)
			return -EIO;
		if (ablock >= HFSPLUS_I(inode).alloc_blocks) {
			res = hfsplus_file_extend(inode);
			if (res)
				return res;
		}
	} else
		create = 0;

	if (ablock < HFSPLUS_I(inode).first_blocks) {
		dblock = hfsplus_ext_find_block(HFSPLUS_I(inode).first_extents, ablock);
		goto done;
	}

	down(&HFSPLUS_I(inode).extents_lock);
	res = hfsplus_ext_read_extent(inode, ablock);
	if (!res) {
		dblock = hfsplus_ext_find_block(HFSPLUS_I(inode).cached_extents, ablock -
					     HFSPLUS_I(inode).cached_start);
	} else {
		up(&HFSPLUS_I(inode).extents_lock);
		return -EIO;
	}
	up(&HFSPLUS_I(inode).extents_lock);

done:
	dprint(DBG_EXTENT, "get_block(%lu): %llu - %u\n", inode->i_ino, (long long)iblock, dblock);
	mask = (1 << HFSPLUS_SB(sb).fs_shift) - 1;
	map_bh(bh_result, sb, (dblock << HFSPLUS_SB(sb).fs_shift) + HFSPLUS_SB(sb).blockoffset + (iblock & mask));
	if (create) {
		set_buffer_new(bh_result);
		HFSPLUS_I(inode).phys_size += sb->s_blocksize;
		inode->i_blocks++;
		mark_inode_dirty(inode);
	}
	return 0;
}

static int hfsplus_link(struct dentry *src_dentry, struct inode *dst_dir,
			struct dentry *dst_dentry)
{
	struct super_block *sb = dst_dir->i_sb;
	struct inode *inode = src_dentry->d_inode;
	struct inode *src_dir = src_dentry->d_parent->d_inode;
	struct qstr str;
	char name[32];
	u32 cnid, id;
	int res;

	if (HFSPLUS_IS_RSRC(inode))
		return -EPERM;

	if (inode->i_ino == (u32)(unsigned long)src_dentry->d_fsdata) {
		for (;;) {
			get_random_bytes(&id, sizeof(cnid));
			id &= 0x3fffffff;
			str.name = name;
			str.len = sprintf(name, "iNode%d", id);
			res = hfsplus_rename_cat(inode->i_ino,
						 src_dir, &src_dentry->d_name,
						 HFSPLUS_SB(sb).hidden_dir, &str);
			if (!res)
				break;
			if (res != -EEXIST)
				return res;
		}
		HFSPLUS_I(inode).dev = id;
		cnid = HFSPLUS_SB(sb).next_cnid++;
		src_dentry->d_fsdata = (void *)(unsigned long)cnid;
		res = hfsplus_create_cat(cnid, src_dir, &src_dentry->d_name, inode);
		if (res)
			/* panic? */
			return res;
		HFSPLUS_SB(sb).file_count++;
	}
	cnid = HFSPLUS_SB(sb).next_cnid++;
	res = hfsplus_create_cat(cnid, dst_dir, &dst_dentry->d_name, inode);
	if (res)
		return res;

	inc_nlink(inode);
	hfsplus_instantiate(dst_dentry, inode, cnid);
	atomic_inc(&inode->i_count);
	inode->i_ctime = CURRENT_TIME_SEC;
	mark_inode_dirty(inode);
	HFSPLUS_SB(sb).file_count++;
	sb->s_dirt = 1;

	return 0;
}

static int hfsplus_symlink(struct inode *dir, struct dentry *dentry,
			   const char *symname)
{
	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
	struct inode *inode;
	int res = -ENOSPC;

	mutex_lock(&sbi->vh_mutex);
	inode = hfsplus_new_inode(dir->i_sb, S_IFLNK | S_IRWXUGO);
	if (!inode)
		goto out;

	res = page_symlink(inode, symname, strlen(symname) + 1);
	if (res)
		goto out_err;

	res = hfsplus_create_cat(inode->i_ino, dir, &dentry->d_name, inode);
	if (res)
		goto out_err;

	hfsplus_instantiate(dentry, inode, inode->i_ino);
	mark_inode_dirty(inode);
	goto out;

out_err:
	clear_nlink(inode);
	hfsplus_delete_inode(inode);
	iput(inode);
out:
	mutex_unlock(&sbi->vh_mutex);
	return res;
}

int hfsplus_asc2uni(struct super_block *sb,
		    struct hfsplus_unistr *ustr, int max_unistr_len,
		    const char *astr, int len)
{
	int size, dsize, decompose;
	u16 *dstr, outlen = 0;
	wchar_t c;

	decompose = !test_bit(HFSPLUS_SB_NODECOMPOSE, &HFSPLUS_SB(sb)->flags);
	while (outlen < max_unistr_len && len > 0) {
		size = asc2unichar(sb, astr, len, &c);

		if (decompose)
			dstr = decompose_unichar(c, &dsize);
		else
			dstr = NULL;
		if (dstr) {
			if (outlen + dsize > max_unistr_len)
				break;
			do {
				ustr->unicode[outlen++] = cpu_to_be16(*dstr++);
			} while (--dsize > 0);
		} else
			ustr->unicode[outlen++] = cpu_to_be16(c);

		astr += size;
		len -= size;
	}
	ustr->length = cpu_to_be16(outlen);
	if (len > 0)
		return -ENAMETOOLONG;
	return 0;
}

static int hfs_parse_new_pmap(struct super_block *sb, void *buf,
		struct new_pmap *pm, sector_t *part_start, sector_t *part_size)
{
	struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb);
	int size = be32_to_cpu(pm->pmMapBlkCnt);
	int buf_size = hfsplus_min_io_size(sb);
	int res;
	int i = 0;

	do {
		if (!memcmp(pm->pmPartType, "Apple_HFS", 9) &&
		    (sbi->part < 0 || sbi->part == i)) {
			*part_start += be32_to_cpu(pm->pmPyPartStart);
			*part_size = be32_to_cpu(pm->pmPartBlkCnt);
			return 0;
		}

		if (++i >= size)
			return -ENOENT;

		pm = (struct new_pmap *)((u8 *)pm + HFSPLUS_SECTOR_SIZE);
		if ((u8 *)pm - (u8 *)buf >= buf_size) {
			res = hfsplus_submit_bio(sb,
						 *part_start + HFS_PMAP_BLK + i,
						 buf, (void **)&pm, REQ_OP_READ,
						 0);
			if (res)
				return res;
		}
	} while (pm->pmSig == cpu_to_be16(HFS_NEW_PMAP_MAGIC));

	return -ENOENT;
}

static int hfsplus_system_read_inode(struct inode *inode)
{
	struct hfsplus_vh *vhdr = HFSPLUS_SB(inode->i_sb)->s_vhdr;

	switch (inode->i_ino) {
	case HFSPLUS_EXT_CNID:
		hfsplus_inode_read_fork(inode, &vhdr->ext_file);
		inode->i_mapping->a_ops = &hfsplus_btree_aops;
		break;
	case HFSPLUS_CAT_CNID:
		hfsplus_inode_read_fork(inode, &vhdr->cat_file);
		inode->i_mapping->a_ops = &hfsplus_btree_aops;
		break;
	case HFSPLUS_ALLOC_CNID:
		hfsplus_inode_read_fork(inode, &vhdr->alloc_file);
		inode->i_mapping->a_ops = &hfsplus_aops;
		break;
	case HFSPLUS_START_CNID:
		hfsplus_inode_read_fork(inode, &vhdr->start_file);
		break;
	case HFSPLUS_ATTR_CNID:
		hfsplus_inode_read_fork(inode, &vhdr->attr_file);
		inode->i_mapping->a_ops = &hfsplus_btree_aops;
		break;
	default:
		return -EIO;
	}

	return 0;
}

int hfsplus_journaled_get_block(struct page *page)
{
  struct inode * const inode = page->mapping->host;
  struct super_block * const sb = inode->i_sb;
  struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
  u32 ablock, res;
  sector_t iblock;
  s32 block_num = -1;
  
  iblock = page->index << (PAGE_CACHE_SHIFT - inode->i_blkbits);
  ablock = iblock >> HFSPLUS_SB(sb)->fs_shift;
  if (ablock < hip->first_blocks) {
    block_num = hfsplus_ext_find_block(hip->first_extents, ablock);
  }
  else {
    mutex_lock(&hip->extents_lock);
    res = hfsplus_ext_read_extent(inode, ablock);
    if (!res) {
      mutex_lock(&hip->extents_lock);
      block_num = hfsplus_ext_find_block(hip->cached_extents, ablock -
      hip->cached_start);
      mutex_unlock(&hip->extents_lock);
    } else {
      mutex_unlock(&hip->extents_lock);
    }
    mutex_unlock(&hip->extents_lock);
  }
  
  return block_num;
}

static void hfsplus_put_super(struct super_block *sb)
{
	struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb);

	dprint(DBG_SUPER, "hfsplus_put_super\n");

	if (!sb->s_fs_info)
		return;

	if (!(sb->s_flags & MS_RDONLY) && sbi->s_vhdr) {
		struct hfsplus_vh *vhdr = sbi->s_vhdr;

		vhdr->modify_date = hfsp_now2mt();
		vhdr->attributes |= cpu_to_be32(HFSPLUS_VOL_UNMNT);
		vhdr->attributes &= cpu_to_be32(~HFSPLUS_VOL_INCNSTNT);

		hfsplus_sync_fs(sb, 1);
	}

	hfs_btree_close(sbi->cat_tree);
	hfs_btree_close(sbi->ext_tree);
	iput(sbi->alloc_file);
	iput(sbi->hidden_dir);
	kfree(sbi->s_vhdr);
	kfree(sbi->s_backup_vhdr);
	unload_nls(sbi->nls);
	kfree(sb->s_fs_info);
	sb->s_fs_info = NULL;
}

/*
 * "Blessing" an HFS+ filesystem writes metadata to the superblock informing
 * the platform firmware which file to boot from
 */
static int hfsplus_ioctl_bless(struct file *file, int __user *user_flags)
{
	struct dentry *dentry = file->f_path.dentry;
	struct inode *inode = dentry->d_inode;
	struct hfsplus_sb_info *sbi = HFSPLUS_SB(inode->i_sb);
	struct hfsplus_vh *vh = sbi->s_vhdr;
	struct hfsplus_vh *bvh = sbi->s_backup_vhdr;

	if (!capable(CAP_SYS_ADMIN))
		return -EPERM;

	mutex_lock(&sbi->vh_mutex);

	/* Directory containing the bootable system */
	vh->finder_info[0] = bvh->finder_info[0] =
		cpu_to_be32(parent_ino(dentry));

	/* Bootloader */
	vh->finder_info[1] = bvh->finder_info[1] = cpu_to_be32(inode->i_ino);

	/* Per spec, the OS X system folder - same as finder_info[0] here */
	vh->finder_info[5] = bvh->finder_info[5] =
		cpu_to_be32(parent_ino(dentry));

	mutex_unlock(&sbi->vh_mutex);
	return 0;
}

int hfsplus_asc2uni(struct super_block *sb, struct hfsplus_unistr *ustr,
		    const char *astr, int len)
{
	int size, dsize, decompose;
	u16 *dstr, outlen = 0;
	wchar_t c;

	decompose = !(HFSPLUS_SB(sb).flags & HFSPLUS_SB_NODECOMPOSE);
	while (outlen < HFSPLUS_MAX_STRLEN && len > 0) {
		size = asc2unichar(sb, astr, len, &c);

		if (decompose && (dstr = decompose_unichar(c, &dsize))) {
			if (outlen + dsize > HFSPLUS_MAX_STRLEN)
				break;
			do {
				ustr->unicode[outlen++] = cpu_to_be16(*dstr++);
			} while (--dsize > 0);
		} else
			ustr->unicode[outlen++] = cpu_to_be16(c);

		astr += size;
		len -= size;
	}
	ustr->length = cpu_to_be16(outlen);
	if (len > 0)
		return -ENAMETOOLONG;
	return 0;
}

/*
 * "Blessing" an HFS+ filesystem writes metadata to the superblock informing
 * the platform firmware which file to boot from
 */
static int hfsplus_ioctl_bless(struct file *file, int __user *user_flags)
{
	struct dentry *dentry = file->f_path.dentry;
	struct inode *inode = dentry->d_inode;
	struct hfsplus_sb_info *sbi = HFSPLUS_SB(inode->i_sb);
	struct hfsplus_vh *vh = sbi->s_vhdr;
	struct hfsplus_vh *bvh = sbi->s_backup_vhdr;
	u32 cnid = (unsigned long)dentry->d_fsdata;

	if (!capable(CAP_SYS_ADMIN))
		return -EPERM;

	mutex_lock(&sbi->vh_mutex);

	/* Directory containing the bootable system */
	vh->finder_info[0] = bvh->finder_info[0] =
		cpu_to_be32(parent_ino(dentry));

	/*
	 * Bootloader. Just using the inode here breaks in the case of
	 * hard links - the firmware wants the ID of the hard link file,
	 * but the inode points at the indirect inode
	 */
	vh->finder_info[1] = bvh->finder_info[1] = cpu_to_be32(cnid);

	/* Per spec, the OS X system folder - same as finder_info[0] here */
	vh->finder_info[5] = bvh->finder_info[5] =
		cpu_to_be32(parent_ino(dentry));

	mutex_unlock(&sbi->vh_mutex);
	return 0;
}