On Mon, Feb 15, 2010 at 03:06:10PM +0100, Karel Zak wrote:
> On Sun, Feb 14, 2010 at 04:53:40PM -0800, H. Peter Anvin wrote:
> > On 02/05/2010 12:07 PM, H. Peter Anvin wrote:
> > > On 01/28/2010 02:44 PM, Karel Zak wrote:
> > I would like to suggest the following patch. Otherwise, we are using
> > the minimum alignment *for the current device*, but disk layouts have a
> > nasty tendency to outlive their respective media.
[...]
> In some cases we cannot ignore disk topology, for example for
> desktop-class 4K disks (or some NetApp setups, etc.) you have to use
> alignment_offset to calculate the physical block boundary.
The proper patch to implement your request is:
diff --git a/fdisk/fdisk.c b/fdisk/fdisk.c
index b752d9b..1c7aee1 100644
--- a/fdisk/fdisk.c
+++ b/fdisk/fdisk.c
@@ -1080,11 +1080,15 @@ update_sector_offset(void)
* device where the offset is quarter of of whole size
* of the device).
*/
- unsigned long long x;
+ unsigned long long x = 0;
- if (has_topology)
- x = alignment_offset ? alignment_offset : io_size;
- else
+ if (has_topology) {
+ if (alignment_offset)
+ x = alignment_offset;
+ else if (io_size > 2048 * 512)
+ x = io_size;
+ }
+ if (x == 0)
x = grain = 2048 * 512;
sector_offset = x / sector_size;
--
To unsubscribe from this list: send the line "unsubscribe util-linux-ng" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
