* Made the use of file devices more convenient and complete by adding

the methods IsFile() and GetFilePath() to BDiskDevice, and
  BDiskDeviceRoster::GetFileDeviceForPath().
* Added new syscalls to implement this functionality.
* Added new flag B_DISK_DEVICE_IS_FILE.
* Fixed wrong operator precedence assumption in the BDiskDevice class at
  several places.
* Minor cleanup.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@28052 a95241bf-73f2-0310-859d-f6bbb57e9c96

headers/os/storage/DiskDeviceDefs.h

@@ -62,6 +62,7 @@ enum {
 	B_DISK_DEVICE_HAS_MEDIA		= 0x02,
 	B_DISK_DEVICE_READ_ONLY		= 0x04,
 	B_DISK_DEVICE_WRITE_ONCE	= 0x08,
+	B_DISK_DEVICE_IS_FILE		= 0x10,
 };
 
 // disk system flags

headers/private/kernel/disk_device_manager/ddm_userland_interface.h

@@ -26,21 +26,25 @@ extern "C" {
 partition_id _user_get_next_disk_device_id(int32 *cookie, size_t *neededSize);
 partition_id _user_find_disk_device(const char *filename, size_t *neededSize);
 partition_id _user_find_partition(const char *filename, size_t *neededSize);
+partition_id _user_find_file_disk_device(const char *filename,
+				size_t *neededSize);
 status_t _user_get_disk_device_data(partition_id deviceID, bool deviceOnly,
 				user_disk_device_data *buffer, size_t bufferSize,
 				size_t *neededSize);
 
 partition_id _user_register_file_device(const char *filename);
 status_t _user_unregister_file_device(partition_id deviceID,
-									  const char *filename);
+				const char *filename);
 	// Only a valid deviceID or filename need to be passed. The other one
 	// is -1/NULL. If both is given only filename is ignored.
+status_t _user_get_file_disk_device_path(partition_id id, char* buffer,
+				size_t bufferSize);
 
 // disk systems
 status_t _user_get_disk_system_info(disk_system_id id,
-									user_disk_system_info *info);
+				user_disk_system_info *info);
 status_t _user_get_next_disk_system_info(int32 *cookie,
-										 user_disk_system_info *info);
+				user_disk_system_info *info);
 status_t _user_find_disk_system(const char *name, user_disk_system_info *info);
 
 // disk device modification

headers/private/storage/DiskDevice.h

@@ -37,6 +37,9 @@ public:
 									bool receiveCompleteProgressUpdates = true);
 			status_t			CancelModifications();
 
+			bool				IsFile() const;
+			status_t			GetFilePath(BPath* path) const;
+
 private:
 			friend class BDiskDeviceList;
 			friend class BDiskDeviceRoster;

headers/private/storage/DiskDeviceRoster.h

@@ -28,7 +28,7 @@ enum {
 	// Basic masks
 	B_DEVICE_REQUEST_MOUNT_POINT			= 0x0001,	// mount point changes
 	B_DEVICE_REQUEST_MOUNTING				= 0x0002,	// mounting/unmounting
-	B_DEVICE_REQUEST_PARTITION				= 0x0004,	// partition changes 
+	B_DEVICE_REQUEST_PARTITION				= 0x0004,	// partition changes
 	B_DEVICE_REQUEST_DEVICE					= 0x0008,	// device changes (media changes)
 	B_DEVICE_REQUEST_DEVICE_LIST			= 0x0010,	// device additions/removals
 	B_DEVICE_REQUEST_JOB_LIST				= 0x0020, 	// job addition/initiation/cancellation/completion
@@ -125,6 +125,8 @@ public:
 								BDiskDevice* device);
 			status_t		GetPartitionForPath(const char* filename,
 								BDiskDevice* device, BPartition** _partition);
+			status_t		GetFileDeviceForPath(const char* filename,
+								BDiskDevice* device);
 
 			status_t		StartWatching(BMessenger target,
 								uint32 eventMask = B_DEVICE_REQUEST_ALL);

headers/private/system/syscalls.h

@@ -441,9 +441,14 @@ extern status_t		_kern_get_cpuid(cpuid_info *info, uint32 eax, uint32 cpu);
 /* Disk Device Manager syscalls */
 
 // iterating, retrieving device/partition data
-extern partition_id	_kern_get_next_disk_device_id(int32 *cookie, size_t *neededSize);
+extern partition_id	_kern_get_next_disk_device_id(int32 *cookie,
-extern partition_id	_kern_find_disk_device(const char *filename, size_t *neededSize);
+						size_t *neededSize);
-extern partition_id	_kern_find_partition(const char *filename, size_t *neededSize);
+extern partition_id	_kern_find_disk_device(const char *filename,
+						size_t *neededSize);
+extern partition_id	_kern_find_partition(const char *filename,
+						size_t *neededSize);
+extern partition_id	_kern_find_file_disk_device(const char *filename,
+						size_t *neededSize);
 extern status_t		_kern_get_disk_device_data(partition_id deviceID,
 						bool deviceOnly, struct user_disk_device_data *buffer,
 						size_t bufferSize, size_t *neededSize);
@@ -452,6 +457,8 @@ extern status_t		_kern_unregister_file_device(partition_id deviceID,
 						const char *filename);
 	// Only a valid deviceID or filename need to be passed. The other one
 	// is -1/NULL. If both is given only filename is ignored.
+extern status_t		_kern_get_file_disk_device_path(partition_id id,
+						char* buffer, size_t bufferSize);
 
 // disk systems
 extern status_t		_kern_get_disk_system_info(disk_system_id id,

src/kits/storage/disk_device/DiskDevice.cpp

@@ -59,8 +59,8 @@ BDiskDevice::~BDiskDevice()
 bool
 BDiskDevice::HasMedia() const
 {
-	return (fDeviceData
+	return fDeviceData
-		&& fDeviceData->device_flags & B_DISK_DEVICE_HAS_MEDIA);
+		&& (fDeviceData->device_flags & B_DISK_DEVICE_HAS_MEDIA) != 0;
 }
 
 
@@ -71,8 +71,8 @@ BDiskDevice::HasMedia() const
 bool
 BDiskDevice::IsRemovableMedia() const
 {
-	return (fDeviceData
+	return fDeviceData
-		&& fDeviceData->device_flags & B_DISK_DEVICE_REMOVABLE);
+		&& (fDeviceData->device_flags & B_DISK_DEVICE_REMOVABLE) != 0;
 }
 
 
@@ -80,8 +80,8 @@ BDiskDevice::IsRemovableMedia() const
 bool
 BDiskDevice::IsReadOnlyMedia() const
 {
-	return (fDeviceData
+	return fDeviceData
-		&& fDeviceData->device_flags & B_DISK_DEVICE_READ_ONLY);
+		&& (fDeviceData->device_flags & B_DISK_DEVICE_READ_ONLY) != 0;
 }
 
 
@@ -89,8 +89,8 @@ BDiskDevice::IsReadOnlyMedia() const
 bool
 BDiskDevice::IsWriteOnceMedia() const
 {
-	return (fDeviceData
+	return fDeviceData
-		&& fDeviceData->device_flags & B_DISK_DEVICE_WRITE_ONCE);
+		&& (fDeviceData->device_flags & B_DISK_DEVICE_WRITE_ONCE) != 0;
 }
 
 
@@ -190,7 +190,7 @@ BDiskDevice::Unset()
 status_t
 BDiskDevice::InitCheck() const
 {
-	return (fDeviceData ? B_OK : B_NO_INIT);
+	return fDeviceData ? B_OK : B_NO_INIT;
 }
 
 
@@ -216,7 +216,7 @@ BDiskDevice::IsModified() const
 		{
 			return Visit(device, 0);
 		}
-		
+
 		virtual bool Visit(BPartition *partition, int32 level)
 		{
 			return partition->_IsModified();
@@ -229,7 +229,7 @@ BDiskDevice::IsModified() const
 
 // PrepareModifications
 /*!	\brief Initializes the partition hierarchy for modifications.
- * 	
+ *
  * 	Subsequent modifications are performed on so-called \a shadow structure
  * 	and not written to device until \ref CommitModifications is called.
  *
@@ -333,6 +333,36 @@ BDiskDevice::CancelModifications()
 }
 
 
+/*!	\brief Returns whether or not this device is a virtual device backed
+		up by a file.
+*/
+bool
+BDiskDevice::IsFile() const
+{
+	return fDeviceData
+		&& (fDeviceData->device_flags & B_DISK_DEVICE_IS_FILE) != 0;
+}
+
+
+/*!	\brief Retrieves the path of the file backing up the disk device.*/
+status_t
+BDiskDevice::GetFilePath(BPath* path) const
+{
+	if (path == NULL)
+		return B_BAD_VALUE;
+	if (!IsFile())
+		return B_BAD_TYPE;
+
+	char pathBuffer[B_PATH_NAME_LENGTH];
+	status_t status = _kern_get_file_disk_device_path(
+		fDeviceData->device_partition_data.id, pathBuffer, sizeof(pathBuffer));
+	if (status != B_OK)
+		return status;
+
+	return path->SetTo(pathBuffer);
+}
+
+
 // copy constructor
 /*!	\brief Privatized copy constructor to avoid usage.
 */

src/kits/storage/disk_device/DiskDeviceRoster.cpp

@@ -377,7 +377,7 @@ BDiskDeviceRoster::GetPartitionWithID(int32 id, BDiskDevice *device,
 	return B_OK;
 }
 
-// GetDeviceForPath
+
 status_t
 BDiskDeviceRoster::GetDeviceForPath(const char *filename, BDiskDevice *device)
 {
@@ -392,11 +392,10 @@ BDiskDeviceRoster::GetDeviceForPath(const char *filename, BDiskDevice *device)
 	return device->_SetTo(id, true, neededSize);
 }
 
-// GetPartitionForPath
+
 status_t
 BDiskDeviceRoster::GetPartitionForPath(const char *filename,
-									   BDiskDevice *device,
+	BDiskDevice *device, BPartition **partition)
-									   BPartition **partition)
 {
 	if (!filename || !device || !partition)
 		return B_BAD_VALUE;
@@ -416,6 +415,25 @@ BDiskDeviceRoster::GetPartitionForPath(const char *filename,
 	return B_OK;
 }
 
+
+status_t
+BDiskDeviceRoster::GetFileDeviceForPath(const char *filename,
+	BDiskDevice *device)
+{
+	if (!filename || !device)
+		return B_BAD_VALUE;
+
+	// get the device ID
+	size_t neededSize = 0;
+	partition_id id = _kern_find_file_disk_device(filename, &neededSize);
+	if (id < 0)
+		return id;
+
+	// download the device data
+	return device->_SetTo(id, true, neededSize);
+}
+
+
 // StartWatching
 /*!	\brief Adds a target to the list of targets to be notified on disk device
 		   events.

src/system/kernel/disk_device_manager/KFileDiskDevice.cpp

@@ -27,6 +27,7 @@ KFileDiskDevice::KFileDiskDevice(partition_id id)
 	: KDiskDevice(id),
 	  fFilePath(NULL)
 {
+	SetDeviceFlags(DeviceFlags() | B_DISK_DEVICE_IS_FILE);
 }
 
 // destructor

src/system/kernel/disk_device_manager/ddm_userland_interface.cpp

@@ -4,6 +4,7 @@
  *
  * Authors:
  *		Ingo Weinhold, bonefish@cs.tu-berlin.de
+ *		Axel Dörfler, axeld@pinc-software.de
  */
 
 /*! \file ddm_userland_interface.cpp
@@ -15,6 +16,7 @@
 
 #include <AutoDeleter.h>
 #include <ddm_userland_interface.h>
+#include <fs/KPath.h>
 #include <KDiskDevice.h>
 #include <KDiskDeviceManager.h>
 #include <KDiskDeviceUtils.h>
@@ -328,6 +330,38 @@ _user_find_partition(const char *_filename, size_t *neededSize)
 }
 
 
+partition_id
+_user_find_file_disk_device(const char *_filename, size_t *neededSize)
+{
+	UserStringParameter<false> filename;
+	status_t error = filename.Init(_filename, B_PATH_NAME_LENGTH);
+	if (error != B_OK)
+		return error;
+
+	KPath path(filename, true);
+
+	partition_id id = B_ENTRY_NOT_FOUND;
+	KDiskDeviceManager *manager = KDiskDeviceManager::Default();
+	// find the device
+	if (KFileDiskDevice* device = manager->RegisterFileDevice(path.Path())) {
+		PartitionRegistrar _(device, true);
+		id = device->ID();
+		if (neededSize) {
+			if (DeviceReadLocker locker = device) {
+				// get the needed size
+				UserDataWriter writer;
+				device->WriteUserData(writer);
+				error = copy_to_user_value(neededSize, writer.AllocatedSize());
+				if (error != B_OK)
+					return error;
+			} else
+				return B_ERROR;
+		}
+	}
+	return id;
+}
+
+
 // _user_get_disk_device_data
 /*!	\brief Writes data describing the disk device identified by ID and all
 		   its partitions into the supplied buffer.
@@ -459,6 +493,31 @@ _user_unregister_file_device(partition_id deviceID, const char *_filename)
 }
 
 
+status_t
+_user_get_file_disk_device_path(partition_id id, char* buffer,
+	size_t bufferSize)
+{
+	if (id < 0 || buffer == NULL || bufferSize == 0)
+		return B_BAD_VALUE;
+
+	KDiskDeviceManager *manager = KDiskDeviceManager::Default();
+
+	if (KDiskDevice *device = manager->RegisterDevice(id, true)) {
+		PartitionRegistrar _(device, true);
+		if (DeviceReadLocker locker = device) {
+			KFileDiskDevice* fileDevice
+				= dynamic_cast<KFileDiskDevice*>(device);
+			if (fileDevice == NULL)
+				return B_BAD_VALUE;
+
+			return user_strlcpy(buffer, fileDevice->FilePath(), bufferSize);
+		}
+	}
+
+	return B_ERROR;
+}
+
+
 // _user_get_disk_system_info
 status_t
 _user_get_disk_system_info(disk_system_id id, user_disk_system_info *_info)