Commit Graph

6 Commits

Author SHA1 Message Date
Vladimir Sementsov-Ogievskiy 549084eaed iotest 147: add cases to test new @name parameter of nbd-server-add
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20180119135719.24745-4-vsementsov@virtuozzo.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
2018-01-26 09:37:21 -06:00
Eric Blake 1104d83c72 nbd-client: Refuse read-only client with BDRV_O_RDWR
The NBD spec says that clients should not try to write/trim to
an export advertised as read-only by the server.  But we failed
to check that, and would allow the block layer to use NBD with
BDRV_O_RDWR even when the server is read-only, which meant we
were depending on the server sending a proper EPERM failure for
various commands, and also exposes a leaky abstraction: using
qemu-io in read-write mode would succeed on 'w -z 0 0' because
of local short-circuiting logic, but 'w 0 0' would send a
request over the wire (where it then depends on the server, and
fails at least for qemu-nbd but might pass for other NBD
implementations).

With this patch, a client MUST request read-only mode to access
a server that is doing a read-only export, or else it will get
a message like:

can't open device nbd://localhost:10809/foo: request for write access conflicts with read-only export

It is no longer possible to even attempt writes over the wire
(including the corner case of 0-length writes), because the block
layer enforces the explicit read-only request; this matches the
behavior of qcow2 when backed by a read-only POSIX file.

Fix several iotests to comply with the new behavior (since
qemu-nbd of an internal snapshot, as well as nbd-server-add over QMP,
default to a read-only export, we must tell blockdev-add/qemu-io to
set up a read-only client).

CC: qemu-stable@nongnu.org
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20171108215703.9295-3-eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
2017-11-09 10:10:17 -06:00
Fam Zheng cf1cd117e2 iotests: 147: Don't test inet6 if not available
This is the case in our docker tests, as we use --net=none there. Skip
this method.

Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-05-26 16:48:21 +02:00
Markus Armbruster 9445673ea6 nbd: Tidy up blockdev-add interface
SocketAddress is a simple union, and simple unions are awkward: they
have their variant members wrapped in a "data" object on the wire, and
require additional indirections in C.  I intend to limit its use to
existing external interfaces, and convert all internal interfaces to
SocketAddressFlat.

BlockdevOptionsNbd is an external interface using SocketAddress.  We
already use SocketAddressFlat elsewhere in blockdev-add.  Replace it
by SocketAddressFlat while we can (it's new in 2.9) for simplicity and
consistency.  For example,

    { "execute": "blockdev-add",
      "arguments": { "node-name": "foo", "driver": "nbd",
                     "server": { "type": "inet",
		                 "data": { "host": "localhost",
				           "port": "12345" } } } }

becomes

    { "execute": "blockdev-add",
      "arguments": { "node-name": "foo", "driver": "nbd",
                     "server": { "type": "inet",
		                 "host": "localhost", "port": "12345" } } }

Since the internal interfaces still take SocketAddress, this requires
conversion function socket_address_crumple().  It'll go away when I
update the interfaces.

Unfortunately, SocketAddress is also visible in -drive since 2.8:

    -drive if=none,driver=nbd,server.type=inet,server.data.host=127.0.0.1,server.data.port=12345

Nobody should be using it, as it's fairly new and has never been
documented, so adding still more compatibility gunk to keep it working
isn't worth the trouble.  You now have to use

    -drive if=none,driver=nbd,server.type=inet,server.host=127.0.0.1,server.port=12345

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-id: 1490895797-29094-9-git-send-email-armbru@redhat.com

[mreitz: Change iotest 147 accordingly]

Because of this interface change, iotest 147 has to be adapted.
Unfortunately, we cannot just flatten all of the addresses because
nbd-server-start still takes a plain SocketAddress. Therefore, we need
both and this is most easily achieved by writing the SocketAddress into
the code and flattening it where necessary.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20170330221243.17333-1-mreitz@redhat.com

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-04-03 17:11:39 +02:00
Markus Armbruster 79b7a77eda block: Declare blockdev-add and blockdev-del supported
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>
2017-03-28 15:23:23 +02:00
Max Reitz b74fc7f78e iotests: Add test for NBD's blockdev-add interface
Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-10-27 19:05:23 +02:00