BlockdevRef is an alternate of BlockdevOptions (inline definition) and
str (reference to an existing block device by name). BlockdevRef
value "" is special: "no block device should be referenced." It's
actually interpreted that way in just one place: optional member
@backing of COW formats. Semantics:
* Present means "use this block device" as backing storage
* Absent means "default to the one stored in the image"
* Except "" means "don't use backing storage at all"
The first two are perfectly normal: when the parameter is absent, it
defaults to an implied value, but the value's meaning is the same.
The third one overloads the parameter with a second meaning. The
overloading is *implicit*, i.e. it's not visible in the types. Works
here, because "" is not a value block device ID.
Pressing argument values the schema accepts, but are semantically
invalid, into service to mean "do something else entirely" is not
general, as suitable invalid values need not exist. I also find it
ugly.
To clean this up, we could add a separate flag argument to suppress
@backing, or add a distinct value to @backing. This commit implements
the latter: add JSON null to the values of @backing, deprecate "".
Because we're so close to the 2.10 freeze, implement it in the
stupidest way possible: have qmp_blockdev_add() rewrite null to ""
before anything else can see the null. Works, because BlockdevRef
occurs only within arguments of blockdev-add. The proper way to do it
would be rewriting "" to null, preferably in a cleaner way, but that
requires fixing up code to work with null. Add a TODO comment for
that.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Acked-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Or, rather, force the open of a backing image if one was specified
for creation. Using a similar -unsafe option as rebase, allow qemu-img
to ignore the backing file validation if possible.
It may not always be possible, as in the existing case when a filesize
for the new image was not specified.
This is accomplished by shifting around the conditionals in
bdrv_img_create, such that a backing file is always opened unless we
provide BDRV_O_NO_BACKING. qemu-img is adjusted to pass this new flag
when -u is provided to create.
Sorry for the heinous looking diffstat, but it's mostly whitespace.
Inspired by: https://bugzilla.redhat.com/show_bug.cgi?id=1213786
Signed-off-by: John Snow <jsnow@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
It's been a long journey, but here we are.
The supported blockdev-add is not compatible to its experimental
predecessors; bump all Since: tags to 2.9.
x-blockdev-remove-medium, x-blockdev-insert-medium and
x-blockdev-change need a bit more work, so leave them alone for now.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
There's many tests that need Quorum support in order to run. At the
moment each test implements its own check to see if Quorum is
enabled. This patch centralizes all those checks in a new function
called iotests.supports_quorum().
Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Now that QAPI supports boxed types, we can have unions at the top level
of a command, so let's put our real options directly there for
blockdev-add instead of having a single "options" dict that contains the
real arguments.
blockdev-add is still experimental and we already made substantial
changes to the API recently, so we're free to make changes like this
one, too.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
We want to remove the 'id' option for blockdev-add. This removes one
user of the option and makes it use only node names.
Some test cases that used to work with an unattached BlockBackend are
removed, either because they don't make sense with an attached device or
because the equivalent test case with an attached device already exists.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
While in the long term we want throttling to be its own block filter
BDS, in the short term we want it to be part of the BB instead of a BDS;
even in the long term we may want legacy throttling to be automatically
tied to the BB.
blockdev-insert-medium and blockdev-remove-medium do not retain
throttling information in the BB (deliberately so). Therefore, using
them means tying this information to a BDS, which would break the model
described above. (The same applies to other flags such as
detect_zeroes.) We probably want to move this information to the BB or
its own filter BDS before blockdev-{insert,remove}-medium can be
considered completely stable.
Therefore, mark these functions experimental for the time being.
Suggested-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Acked-by: Markus Armbruster <armbru@redhat.com>
Acked-by: Kevin Wolf <kwolf@redhat.com>
Message-id: 1449847385-13986-2-git-send-email-mreitz@redhat.com
Reviewed-by: Eric Blake <eblake@redhat.com>
[PMM: fixed format nit (underlining) in qmp-commands.hx]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
The quorum driver is always built in, but it is disabled during
run-time if there's no SHA256 support available (see commit e94867e).
This patch skips the quorum test in iotest 139 in that case.
Signed-off-by: Alberto Garcia <berto@igalia.com>
Message-id: 1447172891-20410-1-git-send-email-berto@igalia.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
