On Fri, Sep 25, 2020 at 03:32:48PM -0500, Eric Blake wrote:
+The second is related to exposing the source of various extents within
+the image, with a single context named:
+
+ qemu:allocation-depth
+
+In the allocation depth context, bits 0 and 1 form a tri-state value:
+
+ bits 0-1 clear: NBD_STATE_DEPTH_UNALLOC, means the extent is unallocated
+ bit 0 set: NBD_STATE_DEPTH_LOCAL, the extent is allocated in this image
+ bit 1 set: NBD_STATE_DEPTH_BACKING, the extent is inherited from a
+ backing layer
From the cover description I imagined it would show the actual depth, ie:
top -> backing -> backing -> backing
depth: 1 2 3 .... (0 = unallocated)
I wonder if that is possible? (Perhaps there's something I don't
understand here.)