Commit a5002d53 authored by John Snow's avatar John Snow Committed by Max Reitz
Browse files

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: default avatarJohn Snow <jsnow@redhat.com>
Message-id: 1450122916-4706-6-git-send-email-jsnow@redhat.com
Reviewed-by: default avatarMax Reitz <mreitz@redhat.com>
Signed-off-by: default avatarMax Reitz <mreitz@redhat.com>
parent 92d617ab

block/qapi.c

+4 −3
Original line number Diff line number Diff line
@@ -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

tests/qemu-iotests/110.out

+4 −1
Original line number Diff line number Diff line
@@ -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 ===