[parted-devel] [PATCH] libparted: Fix _device_probe_geometry

[Brian C. Lane]

dev->length is in 512b blocks, sectors should also be in the same units,
so divide sector_size by PED_SECTOR_SIZE_DEFAULT.

CHS sectors also start at 1, so add 1 to it and use 2 as the fallback
default.

FWIW the HDIO_GETGEO ioctl returns this on a 2048 sector 512b/sector scsi_debug
disk:

cyl=1024 heads=1 sectors=2

With this change all tests pass, but it should also be tried with the
32G SD card.
---
 libparted/arch/linux.c | 12 +++---------
 1 file changed, 3 insertions(+), 9 deletions(-)

diff --git a/libparted/arch/linux.c b/libparted/arch/linux.c
index 6422c56..326b956 100644
--- a/libparted/arch/linux.c
+++ b/libparted/arch/linux.c
@@ -871,7 +871,7 @@ _device_probe_geometry (PedDevice* dev)
 
         if (!ioctl (arch_specific->fd, BLKSSZGET, &sector_size)) {
                 /* get the sector count first */
-                dev->bios_geom.sectors = sector_size;
+                dev->bios_geom.sectors = 1 + (sector_size / PED_SECTOR_SIZE_DEFAULT);
                 dev->bios_geom.heads = 255;
         } else if (!ioctl (arch_specific->fd, HDIO_GETGEO, &geometry)
                         && geometry.sectors && geometry.heads) {
@@ -885,20 +885,14 @@ _device_probe_geometry (PedDevice* dev)
                         _("Could not determine sector size for %s: %s.\n"
                           "Using the default sector size (%lld)."),
                         dev->path, strerror (errno), PED_SECTOR_SIZE_DEFAULT);
-                dev->bios_geom.sectors = PED_SECTOR_SIZE_DEFAULT;
+                dev->bios_geom.sectors = 2;
                 dev->bios_geom.heads = 255;
         }
 
-        dev->hw_geom.heads = dev->bios_geom.heads;
-        dev->hw_geom.sectors = dev->bios_geom.sectors;
-
         dev->bios_geom.cylinders
                 = dev->length / (dev->bios_geom.heads
                                  * dev->bios_geom.sectors);
-        dev->hw_geom.cylinders
-                = dev->length / (dev->hw_geom.heads
-                                 * dev->hw_geom.sectors);
-
+        dev->hw_geom = dev->bios_geom;
         return 1;
 }
 
-- 
2.5.0