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: 488981a4af396551a3178d032cc2b41d9553ada2
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>
diff --git a/block/quorum.c b/block/quorum.c
index 4e66221..2f6c45f 100644
--- a/block/quorum.c
+++ b/block/quorum.c
@@ -865,12 +865,6 @@
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 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);
}
