From 9318887cd520906cf387c8e87ddd3fc7e1a235b3 Mon Sep 17 00:00:00 2001
From: "cantab.net!aia21" <cantab.net!aia21>
Date: Wed, 17 Mar 2004 12:22:03 +0000
Subject: [PATCH] Add new API
 device.[hc]::ntfs_device_partition_start_sector_get() and make mkntfs use it.

(Logical change 1.336)
---
 include/ntfs/device.h |  2 ++
 libntfs/device.c      | 37 +++++++++++++++++++++++++++++++++++--
 2 files changed, 37 insertions(+), 2 deletions(-)

diff --git a/include/ntfs/device.h b/include/ntfs/device.h
index 7db9b0e7..4acd2896 100644
--- a/include/ntfs/device.h
+++ b/include/ntfs/device.h
@@ -109,4 +109,6 @@ extern s64 ntfs_cluster_write(const ntfs_volume *vol, const s64 lcn,
 
 extern s64 ntfs_device_size_get(struct ntfs_device *dev, int block_size);
 
+extern s64 ntfs_device_partition_start_sector_get(struct ntfs_device *dev);
+
 #endif /* defined _NTFS_DEVICE_H */
diff --git a/libntfs/device.c b/libntfs/device.c
index dc451d03..d0450c58 100644
--- a/libntfs/device.c
+++ b/libntfs/device.c
@@ -33,6 +33,9 @@
 #ifdef HAVE_LINUX_FD_H
 #	include <linux/fd.h>
 #endif
+#ifdef HAVE_LINUX_HDREG_H
+#	include <linux/hdreg.h>
+#endif
 
 #include "types.h"
 #include "mst.h"
@@ -40,10 +43,13 @@
 #include "device.h"
 
 #if defined(linux) && defined(_IO) && !defined(BLKGETSIZE)
-#define BLKGETSIZE _IO(0x12,96) /* Get device size in 512-byte blocks. */
+#define BLKGETSIZE	_IO(0x12,96)  /* Get device size in 512-byte blocks. */
 #endif
 #if defined(linux) && defined(_IOR) && !defined(BLKGETSIZE64)
-#define BLKGETSIZE64 _IOR(0x12,114,size_t) /* Get device size in bytes. */
+#define BLKGETSIZE64	_IOR(0x12,114,size_t)	/* Get device size in bytes. */
+#endif
+#if defined(linux) && !defined(HDIO_GETGEO)
+#define HDIO_GETGEO	0x0301	/* Get device geometry. */
 #endif
 
 /**
@@ -506,3 +512,30 @@ s64 ntfs_device_size_get(struct ntfs_device *dev, int block_size)
 	return (low + 1LL) / block_size;
 }
 
+/**
+ * ntfs_device_partition_start_sector_get - get starting sector of a partition
+ * @dev:	open device
+ *
+ * On success, return the starting sector of the partition @dev in the parent
+ * block device of @dev.  On error return -1 with errno set to the error code.
+ *
+ * The following error codes are defined:
+ *	ENOTSUP		System does not support HDIO_GETGEO ioctl
+ *	ENOTTY		@dev is a file or a device not supporting HDIO_GETGEO
+ */
+s64 ntfs_device_partition_start_sector_get(struct ntfs_device *dev)
+{
+#ifdef HDIO_GETGEO
+	{	struct hd_geometry geo;
+
+		if (!dev->d_ops->ioctl(dev, HDIO_GETGEO, &geo)) {
+			Dprintf("HDIO_GETGEO start_sect = %lu (0x%lx)\n",
+					geo.start, geo.start);
+			return geo.start;
+		}
+	}
+#else
+	errno = ENOTSUP;
+#endif
+	return -1;
+}