C++ HFSPLUS_I函数代码示例

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;
}

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

	if (HFSPLUS_IS_RSRC(inode))
		return -EPERM;

	mutex_lock(&sbi->vh_mutex);
	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(inode->i_ino,
					 dir, &dentry->d_name,
					 sbi->hidden_dir, &str);
		if (!res) {
			inode->i_flags |= S_DEAD;
			drop_nlink(inode);
		}
		goto out;
	}
	res = hfsplus_delete_cat(cnid, dir, &dentry->d_name);
	if (res)
		goto out;

	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) {
			sbi->file_count--;
			if (!atomic_read(&HFSPLUS_I(inode)->opencnt)) {
				res = hfsplus_delete_cat(inode->i_ino,
							 sbi->hidden_dir,
							 NULL);
				if (!res)
					hfsplus_delete_inode(inode);
			} else
				inode->i_flags |= S_DEAD;
		} else
			hfsplus_delete_inode(inode);
	} else
		sbi->file_count--;
	inode->i_ctime = CURRENT_TIME_SEC;
	mark_inode_dirty(inode);
out:
	mutex_unlock(&sbi->vh_mutex);
	return res;
}

int hfsplus_ext_write_extent(struct inode *inode)
{
	int res;

	mutex_lock(&HFSPLUS_I(inode)->extents_lock);
	res = hfsplus_ext_write_extent_locked(inode);
	mutex_unlock(&HFSPLUS_I(inode)->extents_lock);

	return res;
}

static void hfsplus_evict_inode(struct inode *inode)
{
	dprint(DBG_INODE, "hfsplus_evict_inode: %lu\n", inode->i_ino);
	truncate_inode_pages(&inode->i_data, 0);
	end_writeback(inode);
	if (HFSPLUS_IS_RSRC(inode)) {
		HFSPLUS_I(HFSPLUS_I(inode)->rsrc_inode)->rsrc_inode = NULL;
		iput(HFSPLUS_I(inode)->rsrc_inode);
	}
}

static int hfsplus_dir_release(struct inode *inode, struct file *file)
{
	struct hfsplus_readdir_data *rd = file->private_data;
	if (rd) {
		spin_lock(&HFSPLUS_I(inode)->open_dir_lock);
		list_del(&rd->list);
		spin_unlock(&HFSPLUS_I(inode)->open_dir_lock);
		kfree(rd);
	}
	return 0;
}

static int hfsplus_ext_read_extent(struct inode *inode, u32 block)
{
	struct hfs_find_data fd;
	int res;

	if (block >= HFSPLUS_I(inode).cached_start &&
	    block < HFSPLUS_I(inode).cached_start + HFSPLUS_I(inode).cached_blocks)
		return 0;

	hfs_find_init(HFSPLUS_SB(inode->i_sb).ext_tree, &fd);
	res = __hfsplus_ext_cache_extent(&fd, inode, block);
	hfs_find_exit(&fd);
	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_ioctl_setflags(struct file *file, int __user *user_flags)
{
	struct inode *inode = file_inode(file);
	struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
	unsigned int flags, new_fl = 0;
	int err = 0;

	err = mnt_want_write_file(file);
	if (err)
		goto out;

	if (!inode_owner_or_capable(inode)) {
		err = -EACCES;
		goto out_drop_write;
	}

	if (get_user(flags, user_flags)) {
		err = -EFAULT;
		goto out_drop_write;
	}

	mutex_lock(&inode->i_mutex);

	if ((flags & (FS_IMMUTABLE_FL|FS_APPEND_FL)) ||
	    inode->i_flags & (S_IMMUTABLE|S_APPEND)) {
		if (!capable(CAP_LINUX_IMMUTABLE)) {
			err = -EPERM;
			goto out_unlock_inode;
		}
	}

	/* don't silently ignore unsupported ext2 flags */
	if (flags & ~(FS_IMMUTABLE_FL|FS_APPEND_FL|FS_NODUMP_FL)) {
		err = -EOPNOTSUPP;
		goto out_unlock_inode;
	}

	if (flags & FS_IMMUTABLE_FL)
		new_fl |= S_IMMUTABLE;

	if (flags & FS_APPEND_FL)
		new_fl |= S_APPEND;

	inode_set_flags(inode, new_fl, S_IMMUTABLE | S_APPEND);

	if (flags & FS_NODUMP_FL)
		hip->userflags |= HFSPLUS_FLG_NODUMP;
	else
		hip->userflags &= ~HFSPLUS_FLG_NODUMP;

	inode->i_ctime = CURRENT_TIME_SEC;
	mark_inode_dirty(inode);

out_unlock_inode:
	mutex_unlock(&inode->i_mutex);
out_drop_write:
	mnt_drop_write_file(file);
out:
	return err;
}

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_i_callback(struct rcu_head *head)
{
	struct inode *inode = container_of(head, struct inode, i_rcu);

	INIT_LIST_HEAD(&inode->i_dentry);
	kmem_cache_free(hfsplus_inode_cachep, HFSPLUS_I(inode));
}

static inline int __hfsplus_ext_cache_extent(struct hfs_find_data *fd,
		struct inode *inode, u32 block)
{
	struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
	int res;

	WARN_ON(!mutex_is_locked(&hip->extents_lock));

	if (hip->extent_state & HFSPLUS_EXT_DIRTY) {
		res = __hfsplus_ext_write_extent(inode, fd);
		if (res)
			return res;
	}

	res = __hfsplus_ext_read_extent(fd, hip->cached_extents, inode->i_ino,
					block, HFSPLUS_IS_RSRC(inode) ?
						HFSPLUS_TYPE_RSRC :
						HFSPLUS_TYPE_DATA);
	if (!res) {
		hip->cached_start = be32_to_cpu(fd->key->ext.start_block);
		hip->cached_blocks =
			hfsplus_ext_block_count(hip->cached_extents);
	} else {
		hip->cached_start = hip->cached_blocks = 0;
		hip->extent_state &= ~(HFSPLUS_EXT_DIRTY | HFSPLUS_EXT_NEW);
	}
	return res;
}

static void __hfsplus_ext_write_extent(struct inode *inode,
		struct hfs_find_data *fd)
{
	struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
	int res;

	WARN_ON(!mutex_is_locked(&hip->extents_lock));

	hfsplus_ext_build_key(fd->search_key, inode->i_ino, hip->cached_start,
			      HFSPLUS_IS_RSRC(inode) ?
				HFSPLUS_TYPE_RSRC : HFSPLUS_TYPE_DATA);

	res = hfs_brec_find(fd);
	if (hip->extent_state & HFSPLUS_EXT_NEW) {
		if (res != -ENOENT)
			return;
		hfs_brec_insert(fd, hip->cached_extents,
				sizeof(hfsplus_extent_rec));
		hip->extent_state &= ~(HFSPLUS_EXT_DIRTY | HFSPLUS_EXT_NEW);
	} else {
		if (res)
			return;
		hfs_bnode_write(fd->bnode, hip->cached_extents,
				fd->entryoffset, fd->entrylength);
		hip->extent_state &= ~HFSPLUS_EXT_DIRTY;
	}

	/*
	 * We can't just use hfsplus_mark_inode_dirty here, because we
	 * also get called from hfsplus_write_inode, which should not
	 * redirty the inode.  Instead the callers have to be careful
	 * to explicily mark the inode dirty, too.
	 */
	set_bit(HFSPLUS_I_EXT_DIRTY, &hip->flags);
}

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;

	if (HFSPLUS_IS_RSRC(inode))
		return -EPERM;

	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(inode->i_ino,
					 dir, &dentry->d_name,
					 HFSPLUS_SB(sb).hidden_dir, &str);
		if (!res)
			inode->i_flags |= S_DEAD;
		return res;
	}
	res = hfsplus_delete_cat(cnid, dir, &dentry->d_name);
	if (res)
		return res;

	if (inode->i_nlink > 0)
		drop_nlink(inode);
	hfsplus_delete_inode(inode);
	if (inode->i_ino != cnid && !inode->i_nlink) {
		if (!atomic_read(&HFSPLUS_I(inode).opencnt)) {
			res = hfsplus_delete_cat(inode->i_ino, HFSPLUS_SB(sb).hidden_dir, NULL);
			if (!res)
				hfsplus_delete_inode(inode);
		} else
			inode->i_flags |= S_DEAD;
	} else
		clear_nlink(inode);
	inode->i_ctime = CURRENT_TIME_SEC;
	mark_inode_dirty(inode);

	return res;
}

static int hfsplus_link(struct dentry *src_dentry, struct inode *dst_dir,
			struct dentry *dst_dentry)
{
	struct hfsplus_sb_info *sbi = HFSPLUS_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 (!S_ISREG(inode->i_mode))
		return -EPERM;

	mutex_lock(&sbi->vh_mutex);
	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,
						 sbi->hidden_dir, &str);
			if (!res)
				break;
			if (res != -EEXIST)
				goto out;
		}
		HFSPLUS_I(inode)->linkid = id;
		cnid = sbi->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? */
			goto out;
		sbi->file_count++;
	}
	cnid = sbi->next_cnid++;
	res = hfsplus_create_cat(cnid, dst_dir, &dst_dentry->d_name, inode);
	if (res)
		goto out;

	inc_nlink(inode);
	hfsplus_instantiate(dst_dentry, inode, cnid);
	ihold(inode);
	inode->i_ctime = CURRENT_TIME_SEC;
	mark_inode_dirty(inode);
	sbi->file_count++;
	hfsplus_mark_mdb_dirty(dst_dir->i_sb);
out:
	mutex_unlock(&sbi->vh_mutex);
	return res;
}

static int hfsplus_write_begin(struct file *file, struct address_space *mapping,
			loff_t pos, unsigned len, unsigned flags,
			struct page **pagep, void **fsdata)
{
	*pagep = NULL;
	return cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
				hfsplus_get_block,
				&HFSPLUS_I(mapping->host).phys_size);
}