Am 27.10.2011 10:53, schrieb Kevin Wolf:
Am 26.10.2011 21:51, schrieb Eric Sunshine:
An entry in the VDI block map will hold an offset to the actual block if
the block is allocated, or one of two specially-interpreted values if
not allocated. Using VirtualBox terminology, value VDI_IMAGE_BLOCK_FREE
(0xffffffff) represents a never-allocated block (semantically arbitrary
content). VDI_IMAGE_BLOCK_ZERO (0xfffffffe) represents a "discarded"
block (semantically zero-filled). block/vdi knows only about
VDI_IMAGE_BLOCK_FREE. Teach it about VDI_IMAGE_BLOCK_ZERO.
Signed-off-by: Eric Sunshine <sunsh...@sunshineco.com>
Thanks, applied to the block branch.
Kevin
Kevin, I don't want to block improvements. Nevertheless
I'd like to see a small modification in this patch:
both #defines should be implemented without a type cast.
Please change them or wait until Eric sends an update.
My favorite is this:
#define VDI_UNALLOCATED UINT32_MAX
#define VDI_DISCARD (VDI_UNALLOCATED - 1)
This would also be ok:
#define VDI_UNALLOCATED 0xffffffffU
#define VDI_DISCARD 0xfffffffeU
Using the macro names and the definitions (with type cast)
from the original VirtualBox code would also be ok.
Cheers,
Stefan
