26.09.2020 10:33, Richard W.M. Jones wrote:
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.)
That's possible if we want it. Probably the best way is to add *depth parameter to
bdrv_is_allocated_above (and better on top of my "[PATCH v7 0/5] fix & merge
block_status_above and is_allocated_above")
--
Best regards,
Vladimir
