From a5002d53029df4d7ebaf87c821b3dc07b65e5e52 Mon Sep 17 00:00:00 2001
From: John Snow <jsnow@redhat.com>
Date: Mon, 14 Dec 2015 14:55:16 -0500
Subject: [PATCH] block/qapi: allow best-effort query
For more complex BDS trees that can be created under normal circumstances,
we lose the ability to issue query commands because of our inability to
re-construct the absolute filename.
Instead, omit this field when it is a problem and present as much information
as we can.
This will change the expected output in iotest 110, where we will now see a
json filename and the lack of an absolute filename instead of an error.
Signed-off-by: John Snow <jsnow@redhat.com>
Message-id: 1450122916-4706-6-git-send-email-jsnow@redhat.com
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
---
block/qapi.c | 7 ++++---
tests/qemu-iotests/110.out | 5 ++++-
2 files changed, 8 insertions(+), 4 deletions(-)
diff --git a/block/qapi.c b/block/qapi.c
index 5587c6471c..fecac253de 100644
--- a/block/qapi.c
+++ b/block/qapi.c
@@ -245,10 +245,11 @@ void bdrv_query_image_info(BlockDriverState *bs,
info->has_backing_filename = true;
bdrv_get_full_backing_filename(bs, backing_filename2, PATH_MAX, &err);
if (err) {
- error_propagate(errp, err);
- qapi_free_ImageInfo(info);
+ /* Can't reconstruct the full backing filename, so we must omit
+ * this field and apply a Best Effort to this query. */
g_free(backing_filename2);
- return;
+ backing_filename2 = NULL;
+ error_free(err);
}
/* Always report the full_backing_filename if present, even if it's the
diff --git a/tests/qemu-iotests/110.out b/tests/qemu-iotests/110.out
index 0270980c26..b3584ff87f 100644
--- a/tests/qemu-iotests/110.out
+++ b/tests/qemu-iotests/110.out
@@ -11,7 +11,10 @@ backing file: t.IMGFMT.base (actual path: TEST_DIR/t.IMGFMT.base)
=== Non-reconstructable filename ===
-qemu-img: Cannot use relative backing file names for 'json:{"driver": "IMGFMT", "file": {"set-state.0.event": "read_aio", "image": {"driver": "file", "filename": "TEST_DIR/t.IMGFMT"}, "driver": "blkdebug", "set-state.0.new_state": 42}}'
+image: json:{"driver": "IMGFMT", "file": {"set-state.0.event": "read_aio", "image": {"driver": "file", "filename": "TEST_DIR/t.IMGFMT"}, "driver": "blkdebug", "set-state.0.new_state": 42}}
+file format: IMGFMT
+virtual size: 64M (67108864 bytes)
+backing file: t.IMGFMT.base (cannot determine actual path)
=== Backing name is always relative to the backed image ===
--
2.30.2