Re: [libvirt] [PATCH 18/35] qemu: block: Always set discard for storage nodes
On 04/25/2018 11:15 AM, Peter Krempa wrote:
Enabling discard for the storage node allows the format drivers to
discard snapshots and other things, while configuration of the format
layer actually decides whether to actually discard data on request from
the host.
Signed-off-by: Peter Krempa <pkrempa(a)redhat.com>
---
src/qemu/qemu_block.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
Isn't this related to the {disk|src}->discard value? Which we copied
from patch 3.
So you'd just be unconditionally setting here regardless of what was
configured?
John
diff --git a/src/qemu/qemu_block.c b/src/qemu/qemu_block.c
index b1f495b731..6e76571796 100644
--- a/src/qemu/qemu_block.c
+++ b/src/qemu/qemu_block.c
@@ -1163,7 +1163,10 @@ qemuBlockStorageSourceGetBackendProps(virStorageSourcePtr src,
if (qemuBlockStorageSourceGetBlockdevGetCacheProps(src, fileprops) < 0)
goto cleanup;
- if (virJSONValueObjectAdd(fileprops, "b:read-only", src->readonly,
NULL) < 0)
+ if (virJSONValueObjectAdd(fileprops,
+ "b:read-only", src->readonly,
+ "s:discard", "unmap",
+ NULL) < 0)
goto cleanup;
}