packagefs: Use the package activation file

If the file exists load only the packages specified in it. If it doesn't
exist or any kind of error occurs, fall back to loading all packages in
the packages directory.

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

@@ -22,6 +22,7 @@
 #include <package/PackageInfoAttributes.h>
 
 #include <AutoDeleter.h>
+#include <PackagesDirectoryDefs.h>
 
 #include <fs/KPath.h>
 #include <team.h>
@@ -64,6 +65,13 @@ const char* const* kHomeShineThroughDirectories
 // sanity limit for activation change request
 const size_t kMaxActivationRequestSize = 10 * 1024 * 1024;
 
+// sanity limit for activation file size
+const size_t kMaxActivationFileSize = 10 * 1024 * 1024;
+
+static const char* const kActivationFilePath
+	= PACKAGES_DIRECTORY_CONFIG_DIRECTORY "/"
+		PACKAGES_DIRECTORY_ACTIVATION_FILE;
+
 
 // #pragma mark - ShineThroughDirectory
 
@@ -291,12 +299,7 @@ Volume::~Volume()
 	}
 
 	// delete the packages
-	Package* package = fPackages.Clear(true);
-	while (package != NULL) {
-		Package* next = package->FileNameHashTableNext();
-		package->ReleaseReference();
-		package = next;
-	}
+	_RemoveAllPackages();
 
 	// delete all indices
 	Index* index = fIndices.Clear(true);
@@ -731,6 +734,124 @@ Volume::_AddInitialPackages()
 	dprintf("packagefs: Adding packages from \"%s\"\n",
 		fPackagesDirectory->Path());
 
+	// 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");
+
+		// remove all packages already added
+		{
+			VolumeWriteLocker systemVolumeLocker(_SystemVolumeIfNotSelf());
+			VolumeWriteLocker volumeLocker(this);
+			_RemoveAllPackages();
+		}
+
+		// read the whole directory
+		error = _AddInitialPackagesFromDirectory();
+		if (error != B_OK)
+			RETURN_ERROR(error);
+	}
+
+	// add the packages to the node tree
+	VolumeWriteLocker systemVolumeLocker(_SystemVolumeIfNotSelf());
+	VolumeWriteLocker volumeLocker(this);
+	for (PackageFileNameHashTable::Iterator it = fPackages.GetIterator();
+		Package* package = it.Next();) {
+		error = _AddPackageContent(package, false);
+		if (error != B_OK) {
+			for (it.Rewind(); Package* activePackage = it.Next();) {
+				if (activePackage == package)
+					break;
+				_RemovePackageContent(activePackage, NULL, false);
+			}
+			RETURN_ERROR(error);
+		}
+	}
+
+	return B_OK;
+}
+
+
+status_t
+Volume::_AddInitialPackagesFromActivationFile()
+{
+	// try reading the activation file
+	int fd = openat(fPackagesDirectory->DirectoryFD(),
+		kActivationFilePath, O_RDONLY);
+	if (fd < 0) {
+		INFORM("Failed to open packages activation file: %s\n",
+			strerror(errno));
+		RETURN_ERROR(errno);
+	}
+	FileDescriptorCloser fdCloser(fd);
+
+	// read the whole file into memory to simplify things
+	struct stat st;
+	if (fstat(fd, &st) != 0) {
+		ERROR("Failed to stat packages activation file: %s\n",
+			strerror(errno));
+		RETURN_ERROR(errno);
+	}
+
+	if (st.st_size > kMaxActivationFileSize) {
+		ERROR("The packages activation file is too big.\n");
+		RETURN_ERROR(B_BAD_DATA);
+	}
+
+	char* fileContent = (char*)malloc(st.st_size + 1);
+	if (fileContent == NULL)
+		RETURN_ERROR(B_NO_MEMORY);
+	MemoryDeleter fileContentDeleter(fileContent);
+
+	ssize_t bytesRead = read(fd, fileContent, st.st_size);
+	if (bytesRead < 0) {
+		ERROR("Failed to read packages activation file: %s\n", strerror(errno));
+		RETURN_ERROR(errno);
+	}
+
+	if (bytesRead != st.st_size) {
+		ERROR("Failed to read whole packages activation file\n");
+		RETURN_ERROR(B_ERROR);
+	}
+
+	// null-terminate to simplify parsing
+	fileContent[st.st_size] = '\0';
+
+	// parse the file and add the respective packages
+	const char* packageName = fileContent;
+	char* const fileContentEnd = fileContent + st.st_size;
+	while (packageName < fileContentEnd) {
+		char* packageNameEnd = strchr(packageName, '\n');
+		if (packageNameEnd == NULL)
+			packageNameEnd = fileContentEnd;
+
+		// skip empty lines
+		if (packageName == packageNameEnd) {
+			packageName++;
+			continue;
+		}
+		*packageNameEnd = '\0';
+
+		if (packageNameEnd - packageName >= B_FILE_NAME_LENGTH) {
+			ERROR("Invalid packages activation file content.\n");
+			RETURN_ERROR(B_BAD_DATA);
+		}
+
+		status_t error = _LoadAndAddInitialPackage(packageName);
+		if (error != B_OK)
+			RETURN_ERROR(error);
+
+		packageName = packageNameEnd + 1;
+	}
+
+	return B_OK;
+}
+
+
+status_t
+Volume::_AddInitialPackagesFromDirectory()
+{
 	// iterate through the dir and create packages
 	int fd = dup(fPackagesDirectory->DirectoryFD());
 	if (fd < 0) {
@@ -758,32 +879,27 @@ Volume::_AddInitialPackages()
 			continue;
 		}
 
-		Package* package;
-		if (_LoadPackage(entry->d_name, package) != B_OK)
-			continue;
-		BReference<Package> packageReference(package, true);
-
-		VolumeWriteLocker systemVolumeLocker(_SystemVolumeIfNotSelf());
-		VolumeWriteLocker volumeLocker(this);
-		_AddPackage(package);
-
+		_LoadAndAddInitialPackage(entry->d_name);
 	}
 
-	// add the packages to the node tree
+	return B_OK;
+}
+
+
+status_t
+Volume::_LoadAndAddInitialPackage(const char* name)
+{
+	Package* package;
+	status_t error = _LoadPackage(name, package);
+	if (error != B_OK) {
+		ERROR("Failed to load package \"%s\": %s\n", name, strerror(error));
+		RETURN_ERROR(error);
+	}
+	BReference<Package> packageReference(package, true);
+
 	VolumeWriteLocker systemVolumeLocker(_SystemVolumeIfNotSelf());
 	VolumeWriteLocker volumeLocker(this);
-	for (PackageFileNameHashTable::Iterator it = fPackages.GetIterator();
-		Package* package = it.Next();) {
-		status_t error = _AddPackageContent(package, false);
-		if (error != B_OK) {
-			for (it.Rewind(); Package* activePackage = it.Next();) {
-				if (activePackage == package)
-					break;
-				_RemovePackageContent(activePackage, NULL, false);
-			}
-			RETURN_ERROR(error);
-		}
-	}
+	_AddPackage(package);
 
 	return B_OK;
 }
@@ -805,6 +921,18 @@ Volume::_RemovePackage(Package* package)
 }
 
 
+void
+Volume::_RemoveAllPackages()
+{
+	Package* package = fPackages.Clear(true);
+	while (package != NULL) {
+		Package* next = package->FileNameHashTableNext();
+		package->ReleaseReference();
+		package = next;
+	}
+}
+
+
 inline Package*
 Volume::_FindPackage(const char* fileName) const
 {

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

@@ -111,9 +111,13 @@ private:
 
 private:
 			status_t			_AddInitialPackages();
+			status_t			_AddInitialPackagesFromActivationFile();
+			status_t			_AddInitialPackagesFromDirectory();
+			status_t			_LoadAndAddInitialPackage(const char* name);
 
 	inline	void				_AddPackage(Package* package);
 	inline	void				_RemovePackage(Package* package);
+			void				_RemoveAllPackages();
 	inline	Package*			_FindPackage(const char* fileName) const;
 
 			status_t			_AddPackageContent(Package* package,