Commit Graph

3 Commits

Author SHA1 Message Date
Eric Blake 497a30dbb0 qemu-img: Require -F with -b backing image
Back in commit d9f059aa6c (qemu-img: Deprecate use of -b without -F),
we deprecated the ability to create a file with a backing image that
requires qemu to perform format probing.  Qemu can still probe older
files for backwards compatibility, but it is time to finish off the
ability to create such images, due to the potential security risk they
present.  Update a couple of iotests affected by the change.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20210503213600.569128-3-eblake@redhat.com>
Reviewed-by: Connor Kuehl <ckuehl@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-07-09 13:18:32 +02:00
Vladimir Sementsov-Ogievskiy 9dd003a998 iotests: define group in each iotest
We are going to drop group file. Define group in tests as a preparatory
step.

The patch is generated by

    cd tests/qemu-iotests

    grep '^[0-9]\{3\} ' group | while read line; do
        file=$(awk '{print $1}' <<< "$line");
        groups=$(sed -e 's/^... //' <<< "$line");
        awk "NR==2{print \"# group: $groups\"}1" $file > tmp;
        cat tmp > $file;
    done

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20210116134424.82867-7-vsementsov@virtuozzo.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
2021-01-20 14:53:22 -06:00
Eric Blake 344acbd62f qcow: Tolerate backing_fmt=
qcow has no space in the metadata to store a backing format, and there
are existing qcow images backed both by raw or by other formats
(usually qcow) images, reliant on probing to tell the difference.  On
the bright side, because we probe every time, raw files are marked as
probed and we thus forbid a commit action into the backing file where
guest-controlled contents could change the result of the probe next
time around (the iotest added here proves that).

Still, allowing the user to specify the backing format during
creation, even if we can't record it, is a good thing.  This patch
blindly allows any value that resolves to a known driver, even if the
user's request is a mismatch from what probing finds; then the next
patch will further enhance things to verify that the user's request
matches what we actually probe.  With this and the next patch in
place, we will finally be ready to deprecate the creation of images
where a backing format was not explicitly specified by the user.

Note that this is only for QemuOpts usage; there is no change to the
QAPI to allow a format through -blockdev.

Add a new iotest 301 just for qcow, to demonstrate the latest
behavior, and to make it easier to show the improvements made in the
next patch.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200706203954.341758-6-eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-07-14 15:18:59 +02:00