On 3/17/20 1:16 PM, Alberto Garcia wrote:
Now that the implementation of subclusters is complete we can finally
add the necessary options to create and read images with this feature,
which we call "extended L2 entries".
Signed-off-by: Alberto Garcia <be...@igalia.com>
Reviewed-by: Max Reitz <mre...@redhat.com>
---
+++ b/qapi/block-core.json
@@ -66,6 +66,9 @@
# standalone (read-only) raw image without looking at qcow2
# metadata (since: 4.0)
#
+# @extended-l2: true if the image has extended L2 entries; only valid for
+# compat >= 1.1 (since 5.0)
Looks like we'll have to tweak this to 5.1 now (multiple spots).
+++ b/block/qcow2.h
@@ -231,13 +231,16 @@ enum {
QCOW2_INCOMPAT_DIRTY_BITNR = 0,
QCOW2_INCOMPAT_CORRUPT_BITNR = 1,
QCOW2_INCOMPAT_DATA_FILE_BITNR = 2,
+ QCOW2_INCOMPAT_EXTL2_BITNR = 4,
Why are we skipping bit 3? (Hmm, now I have to go find the earlier
patch that touched the spec...)
aha - the spec documented compression bits (the spec change for those
made 5.0, but the qcow2 implementation did not); we'll have to rebase
depending on what lands first. But the resolution of that merge
conflict will result in both feature bits eventually existing here.
--
Eric Blake, Principal Software Engineer
Red Hat, Inc. +1-919-301-3226
Virtualization: qemu.org | libvirt.org
