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path: root/drivers/hv/hv_snapshot.c
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Diffstat (limited to 'drivers/hv/hv_snapshot.c')
-rw-r--r--drivers/hv/hv_snapshot.c36
1 files changed, 17 insertions, 19 deletions
diff --git a/drivers/hv/hv_snapshot.c b/drivers/hv/hv_snapshot.c
index 815405f2e777..67def4a831c8 100644
--- a/drivers/hv/hv_snapshot.c
+++ b/drivers/hv/hv_snapshot.c
@@ -53,7 +53,6 @@ static struct {
struct vmbus_channel *recv_channel; /* chn we got the request */
u64 recv_req_id; /* request ID. */
struct hv_vss_msg *msg; /* current message */
- void *vss_context; /* for the channel callback */
} vss_transaction;
@@ -74,6 +73,13 @@ static void vss_timeout_func(struct work_struct *dummy);
static DECLARE_DELAYED_WORK(vss_timeout_work, vss_timeout_func);
static DECLARE_WORK(vss_send_op_work, vss_send_op);
+static void vss_poll_wrapper(void *channel)
+{
+ /* Transaction is finished, reset the state here to avoid races. */
+ vss_transaction.state = HVUTIL_READY;
+ hv_vss_onchannelcallback(channel);
+}
+
/*
* Callback when data is received from user mode.
*/
@@ -86,12 +92,7 @@ static void vss_timeout_func(struct work_struct *dummy)
pr_warn("VSS: timeout waiting for daemon to reply\n");
vss_respond_to_host(HV_E_FAIL);
- /* Transaction is finished, reset the state. */
- if (vss_transaction.state > HVUTIL_READY)
- vss_transaction.state = HVUTIL_READY;
-
- hv_poll_channel(vss_transaction.vss_context,
- hv_vss_onchannelcallback);
+ hv_poll_channel(vss_transaction.recv_channel, vss_poll_wrapper);
}
static int vss_handle_handshake(struct hv_vss_msg *vss_msg)
@@ -112,7 +113,7 @@ static int vss_handle_handshake(struct hv_vss_msg *vss_msg)
default:
return -EINVAL;
}
- vss_transaction.state = HVUTIL_READY;
+ hv_poll_channel(vss_transaction.recv_channel, vss_poll_wrapper);
pr_debug("VSS: userspace daemon ver. %d registered\n", dm_reg_value);
return 0;
}
@@ -138,9 +139,8 @@ static int vss_on_msg(void *msg, int len)
if (cancel_delayed_work_sync(&vss_timeout_work)) {
vss_respond_to_host(vss_msg->error);
/* Transaction is finished, reset the state. */
- vss_transaction.state = HVUTIL_READY;
- hv_poll_channel(vss_transaction.vss_context,
- hv_vss_onchannelcallback);
+ hv_poll_channel(vss_transaction.recv_channel,
+ vss_poll_wrapper);
}
} else {
/* This is a spurious call! */
@@ -238,15 +238,8 @@ void hv_vss_onchannelcallback(void *context)
struct icmsg_hdr *icmsghdrp;
struct icmsg_negotiate *negop = NULL;
- if (vss_transaction.state > HVUTIL_READY) {
- /*
- * We will defer processing this callback once
- * the current transaction is complete.
- */
- vss_transaction.vss_context = context;
+ if (vss_transaction.state > HVUTIL_READY)
return;
- }
- vss_transaction.vss_context = NULL;
vmbus_recvpacket(channel, recv_buffer, PAGE_SIZE * 2, &recvlen,
&requestid);
@@ -338,6 +331,11 @@ static void vss_on_reset(void)
int
hv_vss_init(struct hv_util_service *srv)
{
+ if (vmbus_proto_version < VERSION_WIN8_1) {
+ pr_warn("Integration service 'Backup (volume snapshot)'"
+ " not supported on this host version.\n");
+ return -ENOTSUPP;
+ }
recv_buffer = srv->recv_buffer;
/*