Add yet empty package-links directory

* Add PackageLinksDirectory Directory subclass. Currently not doing
  anything.
* PackageFSRoot: Create a PackageLinksDirectory.
* Volume: Add/remove the package links directory for the system volume.

src/add-ons/kernel/file_systems/packagefs/Jamfile

@@ -23,6 +23,7 @@ HAIKU_PACKAGE_FS_SOURCES =
 	PackageFile.cpp
 	PackageFSRoot.cpp
 	PackageLeafNode.cpp
+	PackageLinksDirectory.cpp
 	PackageNode.cpp
 	PackageNodeAttribute.cpp
 	PackageSymlink.cpp

src/add-ons/kernel/file_systems/packagefs/PackageFSRoot.cpp

@@ -11,6 +11,10 @@
 #include <vfs.h>
 
 #include "DebugSupport.h"
+#include "PackageLinksDirectory.h"
+
+
+static const char* const kPackageLinksDirectoryName = "package-links";
 
 
 mutex PackageFSRoot::sRootListLock = MUTEX_INITIALIZER("packagefs root list");
@@ -21,7 +25,8 @@ PackageFSRoot::PackageFSRoot(dev_t deviceID, ino_t nodeID)
 	:
 	fDeviceID(deviceID),
 	fNodeID(nodeID),
-	fSystemVolume(NULL)
+	fSystemVolume(NULL),
+	fPackageLinksDirectory(NULL)
 {
 	rw_lock_init(&fLock, "packagefs root");
 }
@@ -53,6 +58,15 @@ PackageFSRoot::Init()
 	if (error != B_OK)
 		RETURN_ERROR(error);
 
+	// create package links directory
+	fPackageLinksDirectory = new(std::nothrow) PackageLinksDirectory;
+	if (fPackageLinksDirectory == NULL)
+		return B_NO_MEMORY;
+
+	error = fPackageLinksDirectory->Init(NULL, kPackageLinksDirectoryName);
+	if (error != B_OK)
+		RETURN_ERROR(error);
+
 	return B_OK;
 }
 

src/add-ons/kernel/file_systems/packagefs/PackageFSRoot.h

@@ -17,6 +17,9 @@
 #include "Volume.h"
 
 
+class PackageLinksDirectory;
+
+
 class PackageFSRoot : private BReferenceable,
 	public DoublyLinkedListLinkImpl<PackageFSRoot> {
 public:
@@ -45,6 +48,8 @@ public:
 			bool				IsCustom() const	{ return fDeviceID < 0; }
 
 			Volume*				SystemVolume() const;
+			PackageLinksDirectory* GetPackageLinksDirectory() const
+									{ return fPackageLinksDirectory; }
 
 private:
 			typedef DoublyLinkedList<PackageFSRoot> RootList;
@@ -69,6 +74,7 @@ private:
 			VolumeList			fVolumes;
 			Volume*				fSystemVolume;
 			PackageFamilyHashTable fPackageFamilies;
+			PackageLinksDirectory* fPackageLinksDirectory;
 };
 
 

src/add-ons/kernel/file_systems/packagefs/PackageLinksDirectory.cpp

@@ -0,0 +1,116 @@
+/*
+ * Copyright 2011, Ingo Weinhold, ingo_weinhold@gmx.de.
+ * Distributed under the terms of the MIT License.
+ */
+
+
+#include "PackageLinksDirectory.h"
+
+#include "AttributeDirectoryCookie.h"
+
+
+namespace {
+
+class EmptyAttributeDirectoryCookie : public AttributeDirectoryCookie {
+public:
+	virtual status_t Close()
+	{
+		return B_OK;
+	}
+
+	virtual status_t Read(dev_t volumeID, ino_t nodeID, struct dirent* buffer,
+		size_t bufferSize, uint32* _count)
+	{
+		*_count = 0;
+		return B_OK;
+	}
+
+	virtual status_t Rewind()
+	{
+		return B_OK;
+	}
+};
+
+
+}	// unnamed namespace
+
+
+PackageLinksDirectory::PackageLinksDirectory()
+	:
+	Directory(0)
+		// the ID needs to be assigned later, when added to a volume
+{
+	bigtime_t timeMicros = real_time_clock_usecs();
+
+	fModifiedTime.tv_sec = timeMicros / 1000000;
+	fModifiedTime.tv_nsec = (timeMicros % 1000000) * 1000;
+}
+
+
+PackageLinksDirectory::~PackageLinksDirectory()
+{
+}
+
+
+status_t
+PackageLinksDirectory::Init(Directory* parent, const char* name)
+{
+	return Directory::Init(parent, name);
+}
+
+
+mode_t
+PackageLinksDirectory::Mode() const
+{
+	return S_IFDIR | S_IRUSR | S_IXUSR | S_IRGRP | S_IXGRP | S_IROTH | S_IXOTH;
+}
+
+
+uid_t
+PackageLinksDirectory::UserID() const
+{
+	return 0;
+}
+
+
+gid_t
+PackageLinksDirectory::GroupID() const
+{
+	return 0;
+}
+
+
+timespec
+PackageLinksDirectory::ModifiedTime() const
+{
+	return fModifiedTime;
+}
+
+
+off_t
+PackageLinksDirectory::FileSize() const
+{
+	return 0;
+}
+
+
+status_t
+PackageLinksDirectory::OpenAttributeDirectory(
+	AttributeDirectoryCookie*& _cookie)
+{
+	AttributeDirectoryCookie* cookie
+		= new(std::nothrow) EmptyAttributeDirectoryCookie;
+	if (cookie == NULL)
+		return B_NO_MEMORY;
+
+	_cookie = cookie;
+	return B_OK;
+}
+
+
+status_t
+PackageLinksDirectory::OpenAttribute(const char* name, int openMode,
+	AttributeCookie*& _cookie)
+{
+	return B_ENTRY_NOT_FOUND;
+}

src/add-ons/kernel/file_systems/packagefs/PackageLinksDirectory.h

@@ -0,0 +1,35 @@
+/*
+ * Copyright 2011, Ingo Weinhold, ingo_weinhold@gmx.de.
+ * Distributed under the terms of the MIT License.
+ */
+#ifndef PACKAGE_LINKS_DIRECTORY_H
+#define PACKAGE_LINKS_DIRECTORY_H
+
+
+#include "Directory.h"
+
+
+class PackageLinksDirectory : public Directory {
+public:
+								PackageLinksDirectory();
+	virtual						~PackageLinksDirectory();
+
+	virtual	status_t			Init(Directory* parent, const char* name);
+
+	virtual	mode_t				Mode() const;
+	virtual	uid_t				UserID() const;
+	virtual	gid_t				GroupID() const;
+	virtual	timespec			ModifiedTime() const;
+	virtual	off_t				FileSize() const;
+
+	virtual	status_t			OpenAttributeDirectory(
+									AttributeDirectoryCookie*& _cookie);
+	virtual	status_t			OpenAttribute(const char* name, int openMode,
+									AttributeCookie*& _cookie);
+
+private:
+			timespec			fModifiedTime;
+};
+
+
+#endif	// PACKAGE_LINKS_DIRECTORY_H

src/add-ons/kernel/file_systems/packagefs/Volume.cpp

@@ -35,6 +35,7 @@
 #include "PackageDirectory.h"
 #include "PackageFile.h"
 #include "PackageFSRoot.h"
+#include "PackageLinksDirectory.h"
 #include "PackageSymlink.h"
 #include "Resolvable.h"
 #include "UnpackingLeafNode.h"
@@ -447,8 +448,12 @@ Volume::~Volume()
 		node = next;
 	}
 
-	if (fPackageFSRoot != NULL)
+	if (fPackageFSRoot != NULL) {
+		if (this == fPackageFSRoot->SystemVolume())
+			_RemovePackageLinksDirectory();
+
 		fPackageFSRoot->UnregisterVolume(this);
+	}
 
 	if (fRootDirectory != NULL)
 		fRootDirectory->ReleaseReference();
@@ -1375,6 +1380,37 @@ Volume::_CreateShineThroughDirectories(const char* shineThroughSetting)
 status_t
 Volume::_AddPackageLinksDirectory()
 {
-// TODO:...
+	// called when mounting, so we don't need to lock the volume
+
+	PackageLinksDirectory* packageLinksDirectory
+		= fPackageFSRoot->GetPackageLinksDirectory();
+
+	NodeWriteLocker rootDirectoryWriteLocker(fRootDirectory);
+	NodeWriteLocker packageLinksDirectoryWriteLocker(packageLinksDirectory);
+
+	packageLinksDirectory->SetID(fNextNodeID++);
+	packageLinksDirectory->SetParent(fRootDirectory);
+
+	fRootDirectory->AddChild(packageLinksDirectory);
+	fNodes.Insert(packageLinksDirectory);
+	packageLinksDirectory->AcquireReference();
+
 	return B_OK;
 }
+
+
+void
+Volume::_RemovePackageLinksDirectory()
+{
+	PackageLinksDirectory* packageLinksDirectory
+		= fPackageFSRoot->GetPackageLinksDirectory();
+
+	VolumeWriteLocker volumeLocker(this);
+	NodeWriteLocker rootDirectoryWriteLocker(fRootDirectory);
+	NodeWriteLocker packageLinksDirectoryWriteLocker(packageLinksDirectory);
+
+	if (packageLinksDirectory->Parent() == fRootDirectory) {
+		_RemoveNode(packageLinksDirectory);
+		packageLinksDirectory->SetParent(NULL);
+	}
+}

src/add-ons/kernel/file_systems/packagefs/Volume.h

@@ -144,7 +144,10 @@ private:
 			status_t			_InitMountType(const char* mountType);
 			status_t			_CreateShineThroughDirectories(
 									const char* shineThroughSetting);
+
 			status_t			_AddPackageLinksDirectory();
+			void				_RemovePackageLinksDirectory();
+
 private:
 	mutable	rw_lock				fLock;
 			fs_volume*			fFSVolume;