Extend API to pass dev_offset

Add option device offset.

include/ntfs-3g/device.h

@@ -90,6 +90,8 @@ struct ntfs_device {
 						   heads or -1. */
 	int d_sectors_per_track;		/* Disk geometry: number of
 						   sectors per track or -1. */
+	s64 dev_offset;				/* Offset from the start of the device
+						   where the ntfs filesystem begins.*/
 };
 
 struct stat;
@@ -117,6 +119,9 @@ struct ntfs_device_operations {
 
 extern struct ntfs_device *ntfs_device_alloc(const char *name, const long state,
 		struct ntfs_device_operations *dops, void *priv_data);
+extern struct ntfs_device *ntfs_device_alloc_ext(const char *name, const long state,
+		struct ntfs_device_operations *dops, void *priv_data, s64 dev_offset);
+
 extern int ntfs_device_free(struct ntfs_device *dev);
 extern int ntfs_device_sync(struct ntfs_device *dev);
 

include/ntfs-3g/volume.h

@@ -299,6 +299,7 @@ extern ntfs_volume *ntfs_device_mount(struct ntfs_device *dev,
 		ntfs_mount_flags flags);
 
 extern ntfs_volume *ntfs_mount(const char *name, ntfs_mount_flags flags);
+extern ntfs_volume *ntfs_mount_ext(const char *name, ntfs_mount_flags flags, const s64 dev_offset);
 extern int ntfs_umount(ntfs_volume *vol, const BOOL force);
 
 extern int ntfs_version_is_supported(ntfs_volume *vol);

libntfs-3g/device.c

@@ -114,6 +114,30 @@
 struct ntfs_device *ntfs_device_alloc(const char *name, const long state,
 		struct ntfs_device_operations *dops, void *priv_data)
 {
+	return ntfs_device_alloc_ext(name, state, dops, priv_data, 0);
+}
+
+/**
+ * ntfs_device_alloc_ext - allocate an ntfs device structure and pre-initialize it
+ * @name:	name of the device (must be present)
+ * @state:	initial device state (usually zero)
+ * @dops:	ntfs device operations to use with the device (must be present)
+ * @priv_data:	pointer to private data (optional)
+ * @dev_offset:	offset from beginning of device where the ntfs filesystem begins
+ *
+ * Allocate an ntfs device structure and pre-initialize it with the user-
+ * specified device operations @dops, device state @state, device name @name,
+ * and optional private data @priv_data.
+ *
+ * Note, @name is copied and can hence be freed after this functions returns.
+ *
+ * On success return a pointer to the allocated ntfs device structure and on
+ * error return NULL with errno set to the error code returned by ntfs_malloc().
+ */
+struct ntfs_device *ntfs_device_alloc_ext(const char *name, const long state,
+		struct ntfs_device_operations *dops, void *priv_data, const s64 dev_offset)
+{
+
 	struct ntfs_device *dev;
 
 	if (!name) {
@@ -134,6 +158,7 @@ struct ntfs_device *ntfs_device_alloc(const char *name, const long state,
 		dev->d_private = priv_data;
 		dev->d_heads = -1;
 		dev->d_sectors_per_track = -1;
+		dev->dev_offset = dev_offset;
 	}
 	return dev;
 }

libntfs-3g/volume.c

@@ -1413,13 +1413,46 @@ int ntfs_set_ignore_case(ntfs_volume *vol)
  */
 ntfs_volume *ntfs_mount(const char *name __attribute__((unused)),
 		ntfs_mount_flags flags __attribute__((unused)))
+{
+	return ntfs_mount_ext(name, flags, 0);
+}
+
+/**
+ * ntfs_mount_ext - open ntfs volume with dev_offset
+ * @name:	name of device/file to open
+ * @flags:	optional mount flags
+ * @dev_offset: offset from beginning of device where the ntfs filesystem begins
+ *
+ * This function mounts an ntfs volume. @name should contain the name of the
+ * device/file to mount as the ntfs volume.
+ *
+ * @flags is an optional second parameter. The same flags are used as for
+ * the mount system call (man 2 mount). Currently only the following flags
+ * is implemented:
+ *	NTFS_MNT_RDONLY	- mount volume read-only
+ *
+ * The function opens the device or file @name and verifies that it contains a
+ * valid bootsector. Then, it allocates an ntfs_volume structure and initializes
+ * some of the values inside the structure from the information stored in the
+ * bootsector. It proceeds to load the necessary system files and completes
+ * setting up the structure.
+ *
+ * Return the allocated volume structure on success and NULL on error with
+ * errno set to the error code.
+ *
+ * Note, that a copy is made of @name, and hence it can be discarded as
+ * soon as the function returns.
+ */
+
+ntfs_volume *ntfs_mount_ext(const char *name __attribute__((unused)),
+		ntfs_mount_flags flags __attribute__((unused)), const s64 dev_offset)
 {
 #ifndef NO_NTFS_DEVICE_DEFAULT_IO_OPS
 	struct ntfs_device *dev;
 	ntfs_volume *vol;
 
 	/* Allocate an ntfs_device structure. */
-	dev = ntfs_device_alloc(name, 0, &ntfs_device_default_io_ops, NULL);
+	dev = ntfs_device_alloc_ext(name, 0, &ntfs_device_default_io_ops, NULL, dev_offset);
 	if (!dev)
 		return NULL;
 	/* Call ntfs_device_mount() to do the actual mount. */