Consolidated and fixed device_geometry computation.

* The only implementation that would accept more than 2 TB was the one in
  scsi_disk. But even that one was limited to 63 TB.
* Now there is a new utility function devfs_compute_geometry_size() which
  does it correctly for sizes up to 2^64 which should be good enough for
  quite some time :-)
* This fixes bug #8992.

headers/private/kernel/fs/devfs.h

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2008, Axel Dörfler, [email protected]. All rights reserved.
+ * Copyright 2002-2012, Axel Dörfler, [email protected].
  * Distributed under the terms of the MIT License.
  *
  * Copyright 2001-2002, Travis Geiselbrecht. All rights reserved.
@@ -29,6 +29,9 @@ status_t devfs_publish_device(const char *path, device_hooks *calls);
 status_t devfs_publish_directory(const char *path);
 status_t devfs_rescan_driver(const char *driverName);
 
+void devfs_compute_geometry_size(device_geometry* geometry, uint64 blockCount,
+	uint32 blockSize);
+
 #ifdef __cplusplus
 }
 #endif

src/add-ons/kernel/drivers/disk/scsi/scsi_cd/scsi_cd.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright 2004-2010, Haiku, Inc. All rights reserved.
+ * Copyright 2004-2012, Haiku, Inc. All rights reserved.
  * Copyright 2002-2003, Thomas Kurschel. All rights reserved.
  *
  * Distributed under the terms of the MIT License.
@@ -21,6 +21,7 @@
 
 #include <algorithm>
 
+#include <fs/devfs.h>
 #include <io_requests.h>
 #include <vm/vm_page.h>
 
@@ -205,10 +206,8 @@ get_geometry(cd_handle *handle, device_geometry *geometry)
 	if (status == B_DEV_MEDIA_CHANGED)
 		return B_DEV_MEDIA_CHANGED;
 
-	geometry->bytes_per_sector = info->block_size;
-	geometry->sectors_per_track = 1;
-	geometry->cylinder_count = info->capacity;
-	geometry->head_count = 1;
+	devfs_compute_geometry_size(geometry, info->capacity, info->block_size);
+
 	geometry->device_type = info->device_type;
 	geometry->removable = info->removable;
 

src/add-ons/kernel/drivers/disk/scsi/scsi_disk/scsi_disk.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright 2008, Axel Dörfler, [email protected].
+ * Copyright 2008-2012, Axel Dörfler, [email protected].
  * Copyright 2002/03, Thomas Kurschel. All rights reserved.
  * Distributed under the terms of the MIT License.
  */
@@ -20,6 +20,8 @@
 #include <string.h>
 #include <stdlib.h>
 
+#include <fs/devfs.h>
+
 #include "dma_resources.h"
 #include "IORequest.h"
 #include "IOSchedulerSimple.h"
@@ -65,7 +67,7 @@ static device_manager_info* sDeviceManager;
 
 
 static status_t
-update_capacity(das_driver_info *device)
+update_capacity(das_driver_info* device)
 {
 	TRACE("update_capacity()\n");
 
@@ -88,20 +90,12 @@ get_geometry(das_handle* handle, device_geometry* geometry)
 	das_driver_info* info = handle->info;
 
 	status_t status = update_capacity(info);
-	if (status < B_OK)
+	if (status != B_OK)
 		return status;
 
-	geometry->bytes_per_sector = info->block_size;
-	if (info->capacity > UINT_MAX) {
-		// TODO this doesn't work for capacity greater than 35TB
-		geometry->sectors_per_track = 256;
-		geometry->cylinder_count = info->capacity / (256 * 32);
-		geometry->head_count = 32;
-	} else {
-		geometry->sectors_per_track = 1;
-		geometry->cylinder_count = info->capacity;
-		geometry->head_count = 1;
-	}
+
+	devfs_compute_geometry_size(geometry, info->capacity, info->block_size);
+
 	geometry->device_type = B_DISK;
 	geometry->removable = info->removable;
 

src/add-ons/kernel/drivers/disk/usb/usb_disk/usb_disk.cpp

@@ -1,18 +1,23 @@
 /*
- * Copyright 2008-2010, Haiku Inc. All rights reserved.
+ * Copyright 2008-2012, Haiku Inc. All rights reserved.
  * Distributed under the terms of the MIT License.
  *
  * Authors:
  *		Michael Lotz <[email protected]>
  */
 
-#include <ByteOrder.h>
-#include <KernelExport.h>
-#include <Drivers.h>
-#include <malloc.h>
-#include <stdio.h>
-#include <string.h>
+
 #include "usb_disk.h"
+
+#include <ByteOrder.h>
+#include <Drivers.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <fs/devfs.h>
+
 #include "usb_disk_scsi.h"
 
 
@@ -463,7 +468,7 @@ usb_disk_request_sense(device_lun *lun)
 				TRACE_ALWAYS("request_sense: media changed\n");
 				lun->media_changed = true;
 				lun->media_present = true;
-				
+
 				return B_DEV_MEDIA_CHANGED;
 			}
 			// fall through
@@ -1058,17 +1063,17 @@ usb_disk_ioctl(void *cookie, uint32 op, void *buffer, size_t length)
 					break;
 			}
 
-			device_geometry *geometry = (device_geometry *)buffer;
-			geometry->bytes_per_sector = lun->block_size;
-			geometry->cylinder_count = lun->block_count;
-			geometry->sectors_per_track = geometry->head_count = 1;
-			geometry->device_type = lun->device_type;
-			geometry->removable = lun->removable;
-			geometry->read_only = lun->write_protected;
-			geometry->write_once = (lun->device_type == B_WORM);
+			device_geometry geometry;
+			devfs_compute_geometry_size(&geometry, lun->block_count,
+				lun->block_size);
+
+			geometry.device_type = lun->device_type;
+			geometry.removable = lun->removable;
+			geometry.read_only = lun->write_protected;
+			geometry.write_once = lun->device_type == B_WORM;
 			TRACE("B_GET_GEOMETRY: %ld sectors at %ld bytes per sector\n",
-				geometry->cylinder_count, geometry->bytes_per_sector);
-			result = B_OK;
+				geometry.cylinder_count, geometry.bytes_per_sector);
+			result = user_memcpy(buffer, &geometry, sizeof(device_geometry));
 			break;
 		}
 

src/system/kernel/device_manager/devfs.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2011, Axel Dörfler, axeld@pinc-software.de.
+ * Copyright 2002-2012, Axel Dörfler, axeld@pinc-software.de.
  * Distributed under the terms of the MIT License.
  *
  * Copyright 2001-2002, Travis Geiselbrecht. All rights reserved.
@@ -26,6 +26,7 @@
 #include <debug.h>
 #include <elf.h>
 #include <FindDirectory.h>
+#include <fs/devfs.h>
 #include <fs/KPath.h>
 #include <fs/node_monitor.h>
 #include <kdevice_manager.h>
@@ -1498,17 +1499,16 @@ devfs_ioctl(fs_volume* _volume, fs_vnode* _vnode, void* _cookie, uint32 op,
 				device_geometry geometry;
 				status_t status = vnode->stream.u.dev.device->Control(
 					cookie->device_cookie, op, &geometry, length);
-				if (status < B_OK)
+				if (status != B_OK)
 					return status;
 
 				// patch values to match partition size
-				geometry.sectors_per_track = 0;
 				if (geometry.bytes_per_sector == 0)
 					geometry.bytes_per_sector = 512;
-				geometry.sectors_per_track = partition->info.size
-					/ geometry.bytes_per_sector;
-				geometry.head_count = 1;
-				geometry.cylinder_count = 1;
+
+				devfs_compute_geometry_size(&geometry,
+					partition->info.size / geometry.bytes_per_sector,
+					geometry.bytes_per_sector);
 
 				return user_memcpy(buffer, &geometry, sizeof(device_geometry));
 			}
@@ -2207,6 +2207,21 @@ devfs_unpublish_device(BaseDevice* device, bool disconnect)
 }
 
 
+void
+devfs_compute_geometry_size(device_geometry* geometry, uint64 blockCount,
+	uint32 blockSize)
+{
+	if (blockCount > UINT32_MAX)
+		geometry->head_count = (blockCount + UINT32_MAX - 1) / UINT32_MAX;
+	else
+		geometry->head_count = 1;
+
+	geometry->cylinder_count = 1;
+	geometry->sectors_per_track = blockCount / geometry->head_count;
+	geometry->bytes_per_sector = blockSize;
+}
+
+
 //	#pragma mark - support API for legacy drivers