diff options
| author | Vitaly Kuznetsov <vkuznets@redhat.com> | 2014-11-06 18:21:25 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-11-26 19:00:32 -0800 |
| commit | 8d9560ebcc6448472b3afe8f36f37d6b0de8f5a4 (patch) | |
| tree | 3111728c85dfb7bbd26fce7625d9dfcae742860c /drivers/hv/hv_snapshot.c | |
| parent | 649142074d86afebe0505431a93957505d244dd6 (diff) | |
Drivers: hv: kvp,vss: Fast propagation of userspace communication failure
If we fail to send a message to userspace daemon with cn_netlink_send()
there is no need to wait for userspace to reply as it is not going to
happen. This happens when kvp or vss daemon is stopped after a successful
handshake. Report HV_E_FAIL immediately and cancel the timeout job so
host won't receive two failures.
Use pr_warn() for VSS and pr_debug() for KVP deliberately as VSS request
are rare and result in a failed backup. KVP requests are much more frequent
after a successful handshake so avoid flooding logs. It would be nice to
have an ability to de-negotiate with the host in case userspace daemon gets
disconnected so we won't receive new requests. But I'm not sure it is
possible.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/hv/hv_snapshot.c')
| -rw-r--r-- | drivers/hv/hv_snapshot.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/drivers/hv/hv_snapshot.c b/drivers/hv/hv_snapshot.c index 21e51be74e6c..9d5e0d1efdb5 100644 --- a/drivers/hv/hv_snapshot.c +++ b/drivers/hv/hv_snapshot.c @@ -96,6 +96,7 @@ vss_cn_callback(struct cn_msg *msg, struct netlink_skb_parms *nsp) static void vss_send_op(struct work_struct *dummy) { int op = vss_transaction.msg->vss_hdr.operation; + int rc; struct cn_msg *msg; struct hv_vss_msg *vss_msg; @@ -111,7 +112,12 @@ static void vss_send_op(struct work_struct *dummy) vss_msg->vss_hdr.operation = op; msg->len = sizeof(struct hv_vss_msg); - cn_netlink_send(msg, 0, 0, GFP_ATOMIC); + rc = cn_netlink_send(msg, 0, 0, GFP_ATOMIC); + if (rc) { + pr_warn("VSS: failed to communicate to the daemon: %d\n", rc); + if (cancel_delayed_work_sync(&vss_timeout_work)) + vss_respond_to_host(HV_E_FAIL); + } kfree(msg); return; |