remote: Fix locking in stream APIs

Remote driver needs to make sure the driver lock is released before
entering client IO loop as that may block indefinitely in poll(). As a
direct consequence of not following this in stream APIs, tunneled
migration to a destination host which becomes non-responding may block
qemu driver. Luckily, if keepalive is turned for p2p migrations, both
remote and qemu drivers will get automagically unblocked after keepalive
timeout.
This commit is contained in:
Jiri Denemark 2012-07-17 16:36:23 +02:00
parent c7d5cdb15b
commit 17f3be079c

View File

@ -3976,12 +3976,14 @@ remoteStreamSend(virStreamPtr st,
VIR_DEBUG("st=%p data=%p nbytes=%zu", st, data, nbytes);
struct private_data *priv = st->conn->privateData;
virNetClientStreamPtr privst = st->privateData;
int rv = -1;
remoteDriverLock(priv);
int rv;
if (virNetClientStreamRaiseError(privst))
goto cleanup;
return -1;
remoteDriverLock(priv);
priv->localUses++;
remoteDriverUnlock(priv);
rv = virNetClientStreamSendPacket(privst,
priv->client,
@ -3989,9 +3991,9 @@ remoteStreamSend(virStreamPtr st,
data,
nbytes);
cleanup:
remoteDriverLock(priv);
priv->localUses--;
remoteDriverUnlock(priv);
return rv;
}
@ -4004,12 +4006,14 @@ remoteStreamRecv(virStreamPtr st,
VIR_DEBUG("st=%p data=%p nbytes=%zu", st, data, nbytes);
struct private_data *priv = st->conn->privateData;
virNetClientStreamPtr privst = st->privateData;
int rv = -1;
remoteDriverLock(priv);
int rv;
if (virNetClientStreamRaiseError(privst))
goto cleanup;
return -1;
remoteDriverLock(priv);
priv->localUses++;
remoteDriverUnlock(priv);
rv = virNetClientStreamRecvPacket(privst,
priv->client,
@ -4019,9 +4023,9 @@ remoteStreamRecv(virStreamPtr st,
VIR_DEBUG("Done %d", rv);
cleanup:
remoteDriverLock(priv);
priv->localUses--;
remoteDriverUnlock(priv);
return rv;
}
@ -4138,12 +4142,18 @@ remoteStreamFinish(virStreamPtr st)
if (virNetClientStreamRaiseError(privst))
goto cleanup;
priv->localUses++;
remoteDriverUnlock(priv);
ret = virNetClientStreamSendPacket(privst,
priv->client,
VIR_NET_OK,
NULL,
0);
remoteDriverLock(priv);
priv->localUses--;
cleanup:
virNetClientRemoveStream(priv->client, privst);
virNetClientStreamFree(privst);
@ -4167,12 +4177,18 @@ remoteStreamAbort(virStreamPtr st)
if (virNetClientStreamRaiseError(privst))
goto cleanup;
priv->localUses++;
remoteDriverUnlock(priv);
ret = virNetClientStreamSendPacket(privst,
priv->client,
VIR_NET_ERROR,
NULL,
0);
remoteDriverLock(priv);
priv->localUses--;
cleanup:
virNetClientRemoveStream(priv->client, privst);
virNetClientStreamFree(privst);