packagefs: Initial support for booting into old states

If an old state is specified via mount parameters we load the packages
as specified in its activated-packages file.

The interface for the package daemon, the package daemon itself, and
the package kit are still to be adjusted, so ATM some PM components
might be a bit confused when an old state was booted.

src/add-ons/kernel/file_systems/packagefs/volume/PackagesDirectory.cpp

@@ -17,6 +17,7 @@
 
 PackagesDirectory::PackagesDirectory()
 	:
+	fStateName(),
 	fPath(NULL),
 	fDirFD(-1),
 	fNodeRef(),
@@ -34,7 +35,20 @@ PackagesDirectory::~PackagesDirectory()
 }
 
 
-status_t PackagesDirectory::Init(const char* path, dev_t mountPointDeviceID,
+/*static*/ bool
+PackagesDirectory::IsNewer(const PackagesDirectory* a,
+	const PackagesDirectory* b)
+{
+	if (b->fStateName.IsEmpty())
+		return false;
+	if (a->fStateName.IsEmpty())
+		return true;
+	return strcmp(a->fStateName, b->fStateName) > 0;
+}
+
+
+status_t
+PackagesDirectory::Init(const char* path, dev_t mountPointDeviceID,
 	ino_t mountPointNodeID, struct stat& _st)
 {
 	// Open the directory. We want the path be interpreted depending on from
@@ -56,14 +70,41 @@ status_t PackagesDirectory::Init(const char* path, dev_t mountPointDeviceID,
 			"packages", &vnode);
 	}
 	if (error != B_OK) {
-		ERROR("Failed to open package domain \"%s\"\n", strerror(error));
+		ERROR("Failed to open packages directory \"%s\"\n", strerror(error));
 		RETURN_ERROR(error);
 	}
 
+	return _Init(vnode, _st);
+}
+
+
+status_t
+PackagesDirectory::InitOldState(dev_t adminDirDeviceID, ino_t adminDirNodeID,
+	const char* stateName)
+{
+	if (!fStateName.SetTo(stateName))
+		RETURN_ERROR(B_NO_MEMORY);
+
+	struct vnode* vnode;
+	status_t error = vfs_entry_ref_to_vnode(adminDirDeviceID, adminDirNodeID,
+		stateName, &vnode);
+	if (error != B_OK) {
+		ERROR("Failed to open old state directory \"%s\"\n", strerror(error));
+		RETURN_ERROR(error);
+	}
+
+	struct stat st;
+	return _Init(vnode, st);
+}
+
+
+status_t
+PackagesDirectory::_Init(struct vnode* vnode, struct stat& _st)
+{
 	fDirFD = vfs_open_vnode(vnode, O_RDONLY, true);
 
 	if (fDirFD < 0) {
-		ERROR("Failed to open package domain \"%s\"\n", strerror(fDirFD));
+		ERROR("Failed to open packages directory \"%s\"\n", strerror(fDirFD));
 		vfs_put_vnode(vnode);
 		RETURN_ERROR(fDirFD);
 	}
@@ -83,8 +124,8 @@ status_t PackagesDirectory::Init(const char* path, dev_t mountPointDeviceID,
 		RETURN_ERROR(normalizedPath.InitCheck());
 
 	char* normalizedPathBuffer = normalizedPath.LockBuffer();
-	error = vfs_entry_ref_to_path(fNodeRef.device, fNodeRef.node, NULL, true,
-		normalizedPathBuffer, normalizedPath.BufferSize());
+	status_t error = vfs_entry_ref_to_path(fNodeRef.device, fNodeRef.node, NULL,
+		true, normalizedPathBuffer, normalizedPath.BufferSize());
 	if (error != B_OK)
 		RETURN_ERROR(error);
 

src/add-ons/kernel/file_systems/packagefs/volume/PackagesDirectory.h

@@ -9,15 +9,22 @@
 #include <sys/stat.h>
 
 #include <Referenceable.h>
+#include <util/DoublyLinkedList.h>
+#include <util/OpenHashTable.h>
 
 #include "NodeRef.h"
+#include "String.h"
 
 
-class PackagesDirectory : public BReferenceable {
+class PackagesDirectory : public BReferenceable,
+	public DoublyLinkedListLinkImpl<PackagesDirectory> {
 public:
 								PackagesDirectory();
 								~PackagesDirectory();
 
+			const String&		StateName() const
+									{ return fStateName; }
+									// empty for the latest state
 			const char*			Path() const
 									{ return fPath; }
 			int					DirectoryFD() const
@@ -31,12 +38,57 @@ public:
 
 			status_t			Init(const char* path, dev_t mountPointDeviceID,
 									ino_t mountPointNodeID, struct stat& _st);
+			status_t			InitOldState(dev_t adminDirDeviceID,
+									ino_t adminDirNodeID,
+									const char* stateName);
+
+	static	bool				IsNewer(const PackagesDirectory* a,
+									const PackagesDirectory* b);
+
+			PackagesDirectory*&	HashTableNext()
+									{ return fHashNext; }
 
 private:
+			status_t			_Init(struct vnode* vnode, struct stat& _st);
+
+private:
+			String				fStateName;
 			char*				fPath;
 			int					fDirFD;
 			node_ref			fNodeRef;
+			PackagesDirectory*	fHashNext;
 };
 
 
+struct PackagesDirectoryHashDefinition {
+	typedef const node_ref&		KeyType;
+	typedef	PackagesDirectory	ValueType;
+
+	size_t HashKey(const node_ref& key) const
+	{
+		return (size_t)key.device ^ (size_t)key.node;
+	}
+
+	size_t Hash(const PackagesDirectory* value) const
+	{
+		return HashKey(value->NodeRef());
+	}
+
+	bool Compare(const node_ref& key, const PackagesDirectory* value) const
+	{
+		return key == value->NodeRef();
+	}
+
+	PackagesDirectory*& GetLink(PackagesDirectory* value) const
+	{
+		return value->HashTableNext();
+	}
+};
+
+
+typedef BOpenHashTable<PackagesDirectoryHashDefinition>
+	PackagesDirectoryHashTable;
+typedef DoublyLinkedList<PackagesDirectory> PackagesDirectoryList;
+
+
 #endif	// PACKAGES_DIRECTORY_H

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

@@ -35,7 +35,6 @@
 #include "PackageFSRoot.h"
 #include "PackageLinkDirectory.h"
 #include "PackageLinksDirectory.h"
-#include "PackagesDirectory.h"
 #include "Resolvable.h"
 #include "SizeIndex.h"
 #include "UnpackingLeafNode.h"
@@ -62,6 +61,10 @@ const size_t kMaxActivationRequestSize = 10 * 1024 * 1024;
 // sanity limit for activation file size
 const size_t kMaxActivationFileSize = 10 * 1024 * 1024;
 
+static const char* const kAdministrativeDirectoryName
+	= PACKAGES_DIRECTORY_ADMIN_DIRECTORY;
+static const char* const kActivationFileName
+	= PACKAGES_DIRECTORY_ACTIVATION_FILE;
 static const char* const kActivationFilePath
 	= PACKAGES_DIRECTORY_ADMIN_DIRECTORY "/"
 		PACKAGES_DIRECTORY_ACTIVATION_FILE;
@@ -165,6 +168,8 @@ Volume::Volume(fs_volume* fsVolume)
 	fRootDirectory(NULL),
 	fPackageFSRoot(NULL),
 	fPackagesDirectory(NULL),
+	fPackagesDirectories(),
+	fPackagesDirectoriesByNodeRef(),
 	fPackageSettings(),
 	fNextNodeID(kRootDirectoryID + 1)
 {
@@ -213,8 +218,8 @@ Volume::~Volume()
 	if (fRootDirectory != NULL)
 		fRootDirectory->ReleaseReference();
 
-	if (fPackagesDirectory != NULL)
-		fPackagesDirectory->ReleaseReference();
+	while (PackagesDirectory* directory = fPackagesDirectories.RemoveHead())
+		directory->ReleaseReference();
 
 	rw_lock_destroy(&fLock);
 }
@@ -224,7 +229,11 @@ status_t
 Volume::Mount(const char* parameterString)
 {
 	// init the hash tables
-	status_t error = fNodes.Init();
+	status_t error = fPackagesDirectoriesByNodeRef.Init();
+	if (error != B_OK)
+		RETURN_ERROR(error);
+
+	error = fNodes.Init();
 	if (error != B_OK)
 		RETURN_ERROR(error);
 
@@ -305,6 +314,7 @@ Volume::Mount(const char* parameterString)
 	const char* volumeName = NULL;
 	const char* mountType = NULL;
 	const char* shineThrough = NULL;
+	const char* packagesState = NULL;
 
 	void* parameterHandle = parse_driver_settings_string(parameterString);
 	if (parameterHandle != NULL) {
@@ -315,6 +325,8 @@ Volume::Mount(const char* parameterString)
 		mountType = get_driver_parameter(parameterHandle, "type", NULL, NULL);
 		shineThrough = get_driver_parameter(parameterHandle, "shine-through",
 			NULL, NULL);
+		packagesState = get_driver_parameter(parameterHandle, "state", NULL,
+			NULL);
 	}
 
 	CObjectDeleter<void, status_t> parameterHandleDeleter(parameterHandle,
@@ -348,6 +360,8 @@ Volume::Mount(const char* parameterString)
 	fPackagesDirectory = new(std::nothrow) PackagesDirectory;
 	if (fPackagesDirectory == NULL)
 		RETURN_ERROR(B_NO_MEMORY);
+	fPackagesDirectories.Add(fPackagesDirectory);
+	fPackagesDirectoriesByNodeRef.Insert(fPackagesDirectory);
 
 	struct stat st;
 	error = fPackagesDirectory->Init(packages, fMountPoint.deviceID,
@@ -355,6 +369,13 @@ Volume::Mount(const char* parameterString)
 	if (error != B_OK)
 		RETURN_ERROR(error);
 
+	// If a packages state has been specified, load the needed states.
+	if (packagesState != NULL) {
+		error = _LoadOldPackagesStates(packagesState);
+		if (error != B_OK)
+			RETURN_ERROR(error);
+	}
+
 	// If no volume name is given, infer it from the mount type.
 	if (volumeName == NULL) {
 		switch (fMountType) {
@@ -620,14 +641,89 @@ Volume::PackageLinkNodeChanged(Node* node, uint32 statFields,
 }
 
 
+status_t
+Volume::_LoadOldPackagesStates(const char* packagesState)
+{
+	// open and stat the admininistrative dir
+	int fd = openat(fPackagesDirectory->DirectoryFD(),
+		kAdministrativeDirectoryName, O_RDONLY);
+	if (fd < 0) {
+		ERROR("Failed to open administrative directory: %s\n", strerror(errno));
+		RETURN_ERROR(errno);
+	}
+
+	struct stat adminDirStat;
+	if (fstat(fd, &adminDirStat) < 0) {
+		ERROR("Failed to fstat() administrative directory: %s\n",
+			strerror(errno));
+		RETURN_ERROR(errno);
+	}
+
+	// iterate through the "administrative" dir
+	DIR* dir = fdopendir(fd);
+	if (dir == NULL) {
+		ERROR("Failed to open administrative directory: %s\n", strerror(errno));
+		RETURN_ERROR(errno);
+	}
+	CObjectDeleter<DIR, int> dirCloser(dir, closedir);
+
+	while (dirent* entry = readdir(dir)) {
+		if (strncmp(entry->d_name, "state_", 6) != 0
+			|| strcmp(entry->d_name, packagesState) < 0) {
+			continue;
+		}
+
+		PackagesDirectory* packagesDirectory
+			= new(std::nothrow) PackagesDirectory;
+		status_t error = packagesDirectory->InitOldState(adminDirStat.st_dev,
+			adminDirStat.st_ino, entry->d_name);
+		if (error != B_OK) {
+			delete packagesDirectory;
+			continue;
+		}
+
+		fPackagesDirectories.Add(packagesDirectory);
+		fPackagesDirectoriesByNodeRef.Insert(packagesDirectory);
+
+		INFORM("added old packages dir state \"%s\"\n",
+			packagesDirectory->StateName().Data());
+	}
+
+	// sort the packages directories by state age
+	fPackagesDirectories.Sort(&PackagesDirectory::IsNewer);
+
+	return B_OK;
+}
+
+
 status_t
 Volume::_AddInitialPackages()
 {
-	dprintf("packagefs: Adding packages from \"%s\"\n",
-		fPackagesDirectory->Path());
+	PackagesDirectory* packagesDirectory = fPackagesDirectories.Last();
+	INFORM("Adding packages from \"%s\"\n", packagesDirectory->Path());
+
+	// try reading the activation file of the oldest state
+	status_t error = _AddInitialPackagesFromActivationFile(packagesDirectory);
+	if (error != B_OK && packagesDirectory != fPackagesDirectory) {
+		WARN("Loading packages from old state \"%s\" failed. Loading packages "
+			"from latest state.\n", packagesDirectory->StateName().Data());
+
+		// remove all packages already added
+		{
+			VolumeWriteLocker systemVolumeLocker(_SystemVolumeIfNotSelf());
+			VolumeWriteLocker volumeLocker(this);
+			_RemoveAllPackages();
+		}
+
+		// remove the old states
+		while (fPackagesDirectories.Last() != fPackagesDirectory)
+			fPackagesDirectories.RemoveTail()->ReleaseReference();
+
+		// try reading the activation file of the latest state
+		packagesDirectory = fPackagesDirectory;
+		error = _AddInitialPackagesFromActivationFile(packagesDirectory);
+	}
 
-	// try reading the activation file
-	status_t error = _AddInitialPackagesFromActivationFile();
 	if (error != B_OK) {
 		INFORM("Loading packages from activation file failed. Loading all "
 			"packages in packages directory.\n");
@@ -666,11 +762,14 @@ Volume::_AddInitialPackages()
 
 
 status_t
-Volume::_AddInitialPackagesFromActivationFile()
+Volume::_AddInitialPackagesFromActivationFile(
+	PackagesDirectory* packagesDirectory)
 {
 	// try reading the activation file
-	int fd = openat(fPackagesDirectory->DirectoryFD(),
-		kActivationFilePath, O_RDONLY);
+	int fd = openat(packagesDirectory->DirectoryFD(),
+		packagesDirectory == fPackagesDirectory
+			? kActivationFilePath : kActivationFileName,
+		O_RDONLY);
 	if (fd < 0) {
 		INFORM("Failed to open packages activation file: %s\n",
 			strerror(errno));
@@ -730,7 +829,8 @@ Volume::_AddInitialPackagesFromActivationFile()
 			RETURN_ERROR(B_BAD_DATA);
 		}
 
-		status_t error = _LoadAndAddInitialPackage(packageName);
+		status_t error = _LoadAndAddInitialPackage(packagesDirectory,
+			packageName);
 		if (error != B_OK)
 			RETURN_ERROR(error);
 
@@ -771,7 +871,7 @@ Volume::_AddInitialPackagesFromDirectory()
 			continue;
 		}
 
-		_LoadAndAddInitialPackage(entry->d_name);
+		_LoadAndAddInitialPackage(fPackagesDirectory, entry->d_name);
 	}
 
 	return B_OK;
@@ -779,10 +879,11 @@ Volume::_AddInitialPackagesFromDirectory()
 
 
 status_t
-Volume::_LoadAndAddInitialPackage(const char* name)
+Volume::_LoadAndAddInitialPackage(PackagesDirectory* packagesDirectory,
+	const char* name)
 {
 	Package* package;
-	status_t error = _LoadPackage(name, package);
+	status_t error = _LoadPackage(packagesDirectory, name, package);
 	if (error != B_OK) {
 		ERROR("Failed to load package \"%s\": %s\n", name, strerror(error));
 		RETURN_ERROR(error);
@@ -1309,17 +1410,28 @@ Volume::_RemoveNodeAndVNode(Node* node)
 
 
 status_t
-Volume::_LoadPackage(const char* name, Package*& _package)
+Volume::_LoadPackage(PackagesDirectory* packagesDirectory, const char* name,
+	Package*& _package)
 {
-	// check whether the entry is a file
+	// Find the package -- check the specified packages directory and iterate
+	// toward the newer states.
 	struct stat st;
-	if (fstatat(fPackagesDirectory->DirectoryFD(), name, &st, 0) < 0
-		|| !S_ISREG(st.st_mode)) {
-		return B_BAD_VALUE;
+	for (;;) {
+		if (packagesDirectory == NULL)
+			return B_ENTRY_NOT_FOUND;
+
+		if (fstatat(packagesDirectory->DirectoryFD(), name, &st, 0) == 0) {
+			// check whether the entry is a file
+			if (!S_ISREG(st.st_mode))
+				return B_BAD_VALUE;
+			break;
+		}
+
+		packagesDirectory = fPackagesDirectories.GetPrevious(packagesDirectory);
 	}
 
 	// create a package
-	Package* package = new(std::nothrow) Package(this, fPackagesDirectory,
+	Package* package = new(std::nothrow) Package(this, packagesDirectory,
 		st.st_dev, st.st_ino);
 	if (package == NULL)
 		RETURN_ERROR(B_NO_MEMORY);
@@ -1417,7 +1529,7 @@ INFORM("Volume::_ChangeActivation(): %" B_PRId32 " new packages, %" B_PRId32 " o
 		}
 
 		Package* package;
-		status_t error = _LoadPackage(item->name, package);
+		status_t error = _LoadPackage(fPackagesDirectory, item->name, package);
 		if (error != B_OK) {
 			ERROR("Volume::_ChangeActivation(): failed to load package "
 				"\"%s\"\n", item->name);

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

@@ -21,6 +21,7 @@
 #include "NodeListener.h"
 #include "Package.h"
 #include "PackageLinksListener.h"
+#include "PackagesDirectory.h"
 #include "PackageSettings.h"
 #include "Query.h"
 
@@ -109,10 +110,16 @@ private:
 			struct ActivationChangeRequest;
 
 private:
+			status_t			_LoadOldPackagesStates(
+									const char* packagesState);
+
 			status_t			_AddInitialPackages();
-			status_t			_AddInitialPackagesFromActivationFile();
+			status_t			_AddInitialPackagesFromActivationFile(
+									PackagesDirectory* packagesDirectory);
 			status_t			_AddInitialPackagesFromDirectory();
-			status_t			_LoadAndAddInitialPackage(const char* name);
+			status_t			_LoadAndAddInitialPackage(
+									PackagesDirectory* packagesDirectory,
+									const char* name);
 
 	inline	void				_AddPackage(Package* package);
 	inline	void				_RemovePackage(Package* package);
@@ -145,8 +152,9 @@ private:
 			void				_RemoveNodeAndVNode(Node* node);
 									// caller must hold a reference
 
-			status_t			_LoadPackage(const char* name,
-									Package*& _package);
+			status_t			_LoadPackage(
+									PackagesDirectory* packagesDirectory,
+									const char* name, Package*& _package);
 
 			status_t			_ChangeActivation(
 									ActivationChangeRequest& request);
@@ -178,6 +186,8 @@ private:
 			::PackageFSRoot*	fPackageFSRoot;
 			::MountType			fMountType;
 			PackagesDirectory*	fPackagesDirectory;
+			PackagesDirectoryList fPackagesDirectories;
+			PackagesDirectoryHashTable fPackagesDirectoriesByNodeRef;
 			PackageSettings		fPackageSettings;
 
 			struct {