Commit e94867ed authored Aug 04, 2015 by Sascha Silbe Committed by Peter Maydell Aug 05, 2015

block: don't register quorum driver if SHA256 support is unavailable



Commit 488981a4 [block: convert quorum blockdrv to use crypto APIs]
broke qemu-iotest 041 on hosts with GnuTLS < 2.10.0. It converted a
compile-time check to a run-time check at device open time. The result
is that we now advertise a feature (the quorum block driver) that will
never work (on those hosts). There's no way (short of parsing
human-readable error messages) for qemu-iotests or any other API
consumer to recognise that the quorum block driver isn't _actually_
available and shouldn't be used or tested.

Move the run-time check to bdrv_quorum_init() to avoid registering the
quorum block driver if we know it cannot work. This way API consumers
can recognise it's unavailable.

Fixes: 488981a4
Signed-off-by: Sascha Silbe <silbe@linux.vnet.ibm.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-id: 1438699705-21761-1-git-send-email-silbe@linux.vnet.ibm.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

parent 2be4f242

block/quorum.c

+4 −6

Original line number	Diff line number	Diff line
		@@ -865,12 +865,6 @@ static int quorum_open(BlockDriverState bs, QDict options, int flags,
		int i;
		int ret = 0;

		if (!qcrypto_hash_supports(QCRYPTO_HASH_ALG_SHA256)) {
		error_setg(errp,
		"SHA256 hash support is required for quorum device");
		return -EINVAL;
		}

		qdict_flatten(options);

		/* count how many different children are present */
		@@ -1061,6 +1055,10 @@ static BlockDriver bdrv_quorum = {

		static void bdrv_quorum_init(void)
		{
		if (!qcrypto_hash_supports(QCRYPTO_HASH_ALG_SHA256)) {
		/* SHA256 hash support is required for quorum device */
		return;
		}
		bdrv_register(&bdrv_quorum);
		}