packagefs: Add a .settings package symlink

It points to the settings directory appropriate for global settings.
When a package is installed in ~/config, we cannot use the settings/
subdirectory for global settings, since then the files could clash with
equally named user specific settings files (e.g. in case of
ssh/known_hosts). So we use ~/config/settings/global for global
settings instead.

build/jam/HaikuImage

@@ -212,8 +212,11 @@ AddDirectoryToHaikuImage home mail draft ;
 AddDirectoryToHaikuImage home mail in ;
 AddDirectoryToHaikuImage home mail out ;
 
-AddSymlinkToHaikuImage home config settings : deskbar : be ;
+# global settings when a package is installed in ~/config
+AddDirectoryToHaikuImage home config settings global ;
+
 # Deskbar Application links
+AddSymlinkToHaikuImage home config settings : deskbar : be ;
 AddDirectoryToHaikuImage home config settings deskbar Applications ;
 DESKBAR_APPLICATIONS = ActivityMonitor CharacterMap CodyCam CDPlayer DeskCalc
 	Devices DiskProbe DriveSetup DiskUsage Expander Icon-O-Matic Installer

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

@@ -20,13 +20,15 @@
 
 
 static const char* const kSelfLinkName = ".self";
+static const char* const kSettingsLinkName = ".settings";
 
 
 PackageLinkDirectory::PackageLinkDirectory()
 	:
 	Directory(0),
 		// the ID needs to be assigned later, when added to a volume
-	fSelfLink(NULL)
+	fSelfLink(NULL),
+	fSettingsLink(NULL)
 {
 	get_real_time(fModifiedTime);
 }
@@ -36,6 +38,8 @@ PackageLinkDirectory::~PackageLinkDirectory()
 {
 	if (fSelfLink != NULL)
 		fSelfLink->ReleaseReference();
+	if (fSettingsLink != NULL)
+		fSettingsLink->ReleaseReference();
 
 	while (DependencyLink* link = fDependencyLinks.RemoveHead())
 		link->ReleaseReference();
@@ -154,55 +158,32 @@ PackageLinkDirectory::_Update(PackageLinksListener* listener)
 {
 	// Always remove all dependency links -- if there's still a package, they
 	// will be re-created below.
-	while (DependencyLink* link = fDependencyLinks.RemoveHead()) {
-		NodeWriteLocker linkLocker(link);
-		if (listener != NULL)
-			listener->PackageLinkNodeRemoved(link);
-
-		RemoveChild(link);
-		linkLocker.Unlock();
-		link->ReleaseReference();
-	}
+	while (DependencyLink* link = fDependencyLinks.RemoveHead())
+		_RemoveLink(link, listener);
 
 	// check, if empty
 	Package* package = fPackages.Head();
 	if (package == NULL) {
-		// remove self link, if any
-		if (fSelfLink != NULL) {
-			NodeWriteLocker selfLinkLocker(fSelfLink);
-			if (listener != NULL)
-				listener->PackageLinkNodeRemoved(fSelfLink);
+		// remove self and settings link
+		_RemoveLink(fSelfLink, listener);
+		fSelfLink = NULL;
 
-			RemoveChild(fSelfLink);
-			selfLinkLocker.Unlock();
-			fSelfLink->ReleaseReference();
-			fSelfLink = NULL;
-		}
+		_RemoveLink(fSettingsLink, listener);
+		fSettingsLink = NULL;
 
 		return B_OK;
 	}
 
-	// create/update self link
-	if (fSelfLink == NULL) {
-		fSelfLink = new(std::nothrow) Link(package);
-		if (fSelfLink == NULL)
-			return B_NO_MEMORY;
+	// create/update self and settings link
+	status_t error = _CreateOrUpdateLink(fSelfLink, package,
+		Link::TYPE_INSTALLATION_LOCATION, kSelfLinkName, listener);
+	if (error != B_OK)
+		RETURN_ERROR(error);
 
-		status_t error = fSelfLink->Init(this, kSelfLinkName,
-			NODE_FLAG_CONST_NAME);
-		if (error != B_OK)
-			RETURN_ERROR(error);
-
-		AddChild(fSelfLink);
-
-		if (listener != NULL) {
-			NodeWriteLocker selfLinkLocker(fSelfLink);
-			listener->PackageLinkNodeAdded(fSelfLink);
-		}
-	} else {
-		NodeWriteLocker selfLinkLocker(fSelfLink);
-		fSelfLink->Update(package, listener);
-	}
+	error = _CreateOrUpdateLink(fSettingsLink, package, Link::TYPE_SETTINGS,
+		kSettingsLinkName, listener);
+	if (error != B_OK)
+		RETURN_ERROR(error);
 
 	// update the dependency links
 	return _UpdateDependencies(listener);
@@ -256,3 +237,47 @@ PackageLinkDirectory::_UpdateDependencies(PackageLinksListener* listener)
 
 	return B_OK;
 }
+
+
+void
+PackageLinkDirectory::_RemoveLink(Link* link, PackageLinksListener* listener)
+{
+	if (link != NULL) {
+		NodeWriteLocker linkLocker(link);
+		if (listener != NULL)
+			listener->PackageLinkNodeRemoved(link);
+
+		RemoveChild(link);
+		linkLocker.Unlock();
+		link->ReleaseReference();
+	}
+}
+
+
+status_t
+PackageLinkDirectory::_CreateOrUpdateLink(Link*& link, Package* package,
+	Link::Type type, const char* name, PackageLinksListener* listener)
+{
+	if (link == NULL) {
+		link = new(std::nothrow) Link(package, type);
+		if (link == NULL)
+			return B_NO_MEMORY;
+
+		status_t error = link->Init(this, name, NODE_FLAG_CONST_NAME);
+		if (error != B_OK)
+			RETURN_ERROR(error);
+
+		AddChild(link);
+
+		if (listener != NULL) {
+			NodeWriteLocker lLinkLocker(link);
+			listener->PackageLinkNodeAdded(link);
+		}
+	} else {
+		NodeWriteLocker lLinkLocker(link);
+		link->Update(package, listener);
+	}
+
+
+	return B_OK;
+}

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

@@ -41,7 +41,7 @@ private:
 			struct DependencyLink : public PackageLinkSymlink {
 				DependencyLink(Package* package)
 					:
-					PackageLinkSymlink(package)
+					PackageLinkSymlink(package, TYPE_INSTALLATION_LOCATION)
 				{
 				}
 
@@ -58,10 +58,18 @@ private:
 			status_t			_UpdateDependencies(
 									PackageLinksListener* listener);
 
+			status_t			_CreateOrUpdateLink(Link*& link,
+									Package* package, Link::Type type,
+									const char* name,
+									PackageLinksListener* listener);
+			void				_RemoveLink(Link* link,
+									PackageLinksListener* listener);
+
 private:
 			timespec			fModifiedTime;
 			PackageList			fPackages;
 			Link*				fSelfLink;
+			Link*				fSettingsLink;
 			FamilyDependencyList fDependencyLinks;
 };
 

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

@@ -17,27 +17,32 @@
 #include "Volume.h"
 
 
-static const char* const kSystemLinkPath = "../..";
-static const char* const kCommonLinkPath = "../../../common";
-static const char* const kHomeLinkPath = "../../../home/config";
+static const char* const kLinkPaths[PackageLinkSymlink::TYPE_ENUM_COUNT]
+		[PACKAGE_FS_MOUNT_TYPE_ENUM_COUNT] = {
+	{
+		"../..",
+		"../../../common",
+		"../../../home/config"
+	},
+	{
+		"../../../common/settings",
+		"../../../common/settings",
+		"../../../home/config/settings/global"
+	}
+};
 
 static const char* const kUnknownLinkTarget = "?";
 
 
 static const char*
-link_path_for_mount_type(MountType type)
+link_path_for_mount_type(MountType mountType, PackageLinkSymlink::Type linkType)
 {
-	switch (type) {
-		case PACKAGE_FS_MOUNT_TYPE_SYSTEM:
-			return kSystemLinkPath;
-		case PACKAGE_FS_MOUNT_TYPE_COMMON:
-			return kCommonLinkPath;
-		case PACKAGE_FS_MOUNT_TYPE_HOME:
-			return kHomeLinkPath;
-		case PACKAGE_FS_MOUNT_TYPE_CUSTOM:
-		default:
-			return "?";
+	if (mountType < 0 || mountType >= PACKAGE_FS_MOUNT_TYPE_ENUM_COUNT
+		|| linkType < 0 || linkType >= PackageLinkSymlink::TYPE_ENUM_COUNT) {
+		return kUnknownLinkTarget;
 	}
+
+	return kLinkPaths[linkType][mountType];
 }
 
 
@@ -71,10 +76,11 @@ private:
 // #pragma mark - PackageLinkSymlink
 
 
-PackageLinkSymlink::PackageLinkSymlink(Package* package)
+PackageLinkSymlink::PackageLinkSymlink(Package* package, Type type)
 	:
 	Node(0),
-	fLinkPath(kUnknownLinkTarget)
+	fLinkPath(kUnknownLinkTarget),
+	fType(type)
 {
 	Update(package, NULL);
 }
@@ -94,7 +100,7 @@ PackageLinkSymlink::Update(Package* package, PackageLinksListener* listener)
 		fLinkPath = package->InstallPath();
 		if (fLinkPath == NULL) {
 			fLinkPath = link_path_for_mount_type(
-				package->Volume()->MountType());
+				package->Volume()->MountType(), fType);
 		}
 	} else
 		fLinkPath = kUnknownLinkTarget;

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

@@ -15,7 +15,16 @@ class PackageLinksListener;
 
 class PackageLinkSymlink : public Node {
 public:
-								PackageLinkSymlink(Package* package);
+			enum Type {
+				TYPE_INSTALLATION_LOCATION,
+				TYPE_SETTINGS,
+
+				TYPE_ENUM_COUNT
+			};
+
+public:
+								PackageLinkSymlink(Package* package,
+									Type type);
 	virtual						~PackageLinkSymlink();
 
 			void				Update(Package* package,
@@ -37,6 +46,7 @@ private:
 private:
 			timespec			fModifiedTime;
 			const char*			fLinkPath;
+			Type				fType;
 };