C++ Inode::CheckPermissions方法代码示例

static status_t
ext2_lookup(fs_volume* _volume, fs_vnode* _directory, const char* name,
	ino_t* _vnodeID)
{
	TRACE("ext2_lookup: name address: %p\n", name);
	TRACE("ext2_lookup: name: %s\n", name);
	Volume* volume = (Volume*)_volume->private_volume;
	Inode* directory = (Inode*)_directory->private_node;

	// check access permissions
	status_t status = directory->CheckPermissions(X_OK);
	if (status < B_OK)
		return status;

	HTree htree(volume, directory);
	DirectoryIterator* iterator;

	status = htree.Lookup(name, &iterator);
	if (status != B_OK)
		return status;

	ObjectDeleter<DirectoryIterator> iteratorDeleter(iterator);

	status = iterator->FindEntry(name, _vnodeID);
	if (status != B_OK)
		return status;

	return get_vnode(volume->FSVolume(), *_vnodeID, NULL);
}

static status_t
ext2_open(fs_volume* _volume, fs_vnode* _node, int openMode, void** _cookie)
{
	Volume* volume = (Volume*)_volume->private_volume;
	Inode* inode = (Inode*)_node->private_node;

	// opening a directory read-only is allowed, although you can't read
	// any data from it.
	if (inode->IsDirectory() && (openMode & O_RWMASK) != 0)
		return B_IS_A_DIRECTORY;

	status_t status =  inode->CheckPermissions(open_mode_to_access(openMode)
		| (openMode & O_TRUNC ? W_OK : 0));
	if (status != B_OK)
		return status;

	// Prepare the cookie
	file_cookie* cookie = new(std::nothrow) file_cookie;
	if (cookie == NULL)
		return B_NO_MEMORY;
	ObjectDeleter<file_cookie> cookieDeleter(cookie);

	cookie->open_mode = openMode & EXT2_OPEN_MODE_USER_MASK;
	cookie->last_size = inode->Size();
	cookie->last_notification = system_time();

	MethodDeleter<Inode, status_t> fileCacheEnabler(&Inode::EnableFileCache);
	if ((openMode & O_NOCACHE) != 0) {
		status = inode->DisableFileCache();
		if (status != B_OK)
			return status;
		fileCacheEnabler.SetTo(inode);
	}

	// Should we truncate the file?
	if ((openMode & O_TRUNC) != 0) {
		if ((openMode & O_RWMASK) == O_RDONLY)
			return B_NOT_ALLOWED;

		Transaction transaction(volume->GetJournal());
		inode->WriteLockInTransaction(transaction);

		status_t status = inode->Resize(transaction, 0);
		if (status == B_OK)
			status = inode->WriteBack(transaction);
		if (status == B_OK)
			status = transaction.Done();
		if (status != B_OK)
			return status;

		// TODO: No need to notify file size changed?
	}

	fileCacheEnabler.Detach();
	cookieDeleter.Detach();
	*_cookie = cookie;

	return B_OK;
}

static status_t
ext2_open_dir(fs_volume* _volume, fs_vnode* _node, void** _cookie)
{
	Inode* inode = (Inode*)_node->private_node;
	status_t status = inode->CheckPermissions(R_OK);
	if (status < B_OK)
		return status;

	if (!inode->IsDirectory())
		return B_NOT_A_DIRECTORY;

	DirectoryIterator* iterator = new(std::nothrow) DirectoryIterator(inode);
	if (iterator == NULL)
		return B_NO_MEMORY;

	*_cookie = iterator;
	return B_OK;
}

static status_t
btrfs_lookup(fs_volume* _volume, fs_vnode* _directory, const char* name,
	ino_t* _vnodeID)
{
	TRACE("btrfs_lookup: name address: %p (%s)\n", name, name);
	Volume* volume = (Volume*)_volume->private_volume;
	Inode* directory = (Inode*)_directory->private_node;

	// check access permissions
	status_t status = directory->CheckPermissions(X_OK);
	if (status < B_OK)
		return status;

	status = DirectoryIterator(directory).Lookup(name, strlen(name), _vnodeID);
	if (status != B_OK)
		return status;
	
	return get_vnode(volume->FSVolume(), *_vnodeID, NULL);
}

static status_t
btrfs_open(fs_volume* /*_volume*/, fs_vnode* _node, int openMode,
	void** _cookie)
{
	Inode* inode = (Inode*)_node->private_node;

	// opening a directory read-only is allowed, although you can't read
	// any data from it.
	if (inode->IsDirectory() && (openMode & O_RWMASK) != 0)
		return B_IS_A_DIRECTORY;

	status_t status =  inode->CheckPermissions(open_mode_to_access(openMode)
		| (openMode & O_TRUNC ? W_OK : 0));
	if (status != B_OK)
		return status;

	// Prepare the cookie
	file_cookie* cookie = new(std::nothrow) file_cookie;
	if (cookie == NULL)
		return B_NO_MEMORY;
	ObjectDeleter<file_cookie> cookieDeleter(cookie);

	cookie->open_mode = openMode & BTRFS_OPEN_MODE_USER_MASK;
	cookie->last_size = inode->Size();
	cookie->last_notification = system_time();

	if ((openMode & O_NOCACHE) != 0 && inode->FileCache() != NULL) {
		// Disable the file cache, if requested?
		status = file_cache_disable(inode->FileCache());
		if (status != B_OK)
			return status;
	}

	cookieDeleter.Detach();
	*_cookie = cookie;

	return B_OK;
}

static status_t
btrfs_access(fs_volume* _volume, fs_vnode* _node, int accessMode)
{
	Inode* inode = (Inode*)_node->private_node;
	return inode->CheckPermissions(accessMode);
}

/*static*/ status_t
Inode::Create(Transaction& transaction, Inode* parent, const char* name,
	int32 mode, int openMode, uint8 type, bool* _created, ino_t* _id,
	Inode** _inode, fs_vnode_ops* vnodeOps, uint32 publishFlags)
{
	TRACE("Inode::Create()\n");
	Volume* volume = transaction.GetVolume();

	DirectoryIterator* entries = NULL;
	ObjectDeleter<DirectoryIterator> entriesDeleter;

	if (parent != NULL) {
		parent->WriteLockInTransaction(transaction);

		TRACE("Inode::Create(): Looking up entry destination\n");
		HTree htree(volume, parent);

		status_t status = htree.Lookup(name, &entries);
		if (status == B_ENTRY_NOT_FOUND) {
			panic("We need to add the first node.\n");
			return B_ERROR;
		}
		if (status != B_OK)
			return status;
		entriesDeleter.SetTo(entries);

		TRACE("Inode::Create(): Looking up to see if file already exists\n");
		ino_t entryID;

		status = entries->FindEntry(name, &entryID);
		if (status == B_OK) {
			// File already exists
			TRACE("Inode::Create(): File already exists\n");
			if (S_ISDIR(mode) || S_ISLNK(mode) || (openMode & O_EXCL) != 0)
				return B_FILE_EXISTS;

			Vnode vnode(volume, entryID);
			Inode* inode;

			status = vnode.Get(&inode);
			if (status != B_OK) {
				TRACE("Inode::Create() Failed to get the inode from the "
					"vnode\n");
				return B_ENTRY_NOT_FOUND;
			}

			if (inode->IsDirectory() && (openMode & O_RWMASK) != O_RDONLY)
				return B_IS_A_DIRECTORY;
			if ((openMode & O_DIRECTORY) != 0 && !inode->IsDirectory())
				return B_NOT_A_DIRECTORY;

			if (inode->CheckPermissions(open_mode_to_access(openMode)
					| ((openMode & O_TRUNC) != 0 ? W_OK : 0)) != B_OK)
				return B_NOT_ALLOWED;

			if ((openMode & O_TRUNC) != 0) {
				// Truncate requested
				TRACE("Inode::Create(): Truncating file\n");
				inode->WriteLockInTransaction(transaction);

				status = inode->Resize(transaction, 0);
				if (status != B_OK)
					return status;
			}

			if (_created != NULL)
				*_created = false;
			if (_id != NULL)
				*_id = inode->ID();
			if (_inode != NULL)
				*_inode = inode;

			if (_id != NULL || _inode != NULL)
				vnode.Keep();

			TRACE("Inode::Create(): Done opening file\n");
			return B_OK;
		/*} else if ((mode & S_ATTR_DIR) == 0) {
			TRACE("Inode::Create(): (mode & S_ATTR_DIR) == 0\n");
			return B_BAD_VALUE;*/
		} else if ((openMode & O_DIRECTORY) != 0) {
			TRACE("Inode::Create(): (openMode & O_DIRECTORY) != 0\n");
			return B_ENTRY_NOT_FOUND;
		}

		// Return to initial position
		TRACE("Inode::Create(): Restarting iterator\n");
		entries->Restart();
	}

	status_t status;
	if (parent != NULL) {
		status = parent->CheckPermissions(W_OK);
		if (status != B_OK)
			return status;
	}

	TRACE("Inode::Create(): Allocating inode\n");
	ino_t id;
	status = volume->AllocateInode(transaction, parent, mode, id);
//.........这里部分代码省略.........