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-rw-r--r--net/sunrpc/clnt.c143
1 files changed, 136 insertions, 7 deletions
diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index 5abab09..5bc2f45 100644
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -36,7 +36,9 @@
#include <linux/sunrpc/clnt.h>
#include <linux/sunrpc/rpc_pipe_fs.h>
#include <linux/sunrpc/metrics.h>
+#include <linux/sunrpc/bc_xprt.h>
+#include "sunrpc.h"
#ifdef RPC_DEBUG
# define RPCDBG_FACILITY RPCDBG_CALL
@@ -63,6 +65,9 @@ static void call_decode(struct rpc_task *task);
static void call_bind(struct rpc_task *task);
static void call_bind_status(struct rpc_task *task);
static void call_transmit(struct rpc_task *task);
+#if defined(CONFIG_NFS_V4_1)
+static void call_bc_transmit(struct rpc_task *task);
+#endif /* CONFIG_NFS_V4_1 */
static void call_status(struct rpc_task *task);
static void call_transmit_status(struct rpc_task *task);
static void call_refresh(struct rpc_task *task);
@@ -613,6 +618,50 @@ rpc_call_async(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags,
}
EXPORT_SYMBOL_GPL(rpc_call_async);
+#if defined(CONFIG_NFS_V4_1)
+/**
+ * rpc_run_bc_task - Allocate a new RPC task for backchannel use, then run
+ * rpc_execute against it
+ * @ops: RPC call ops
+ */
+struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req,
+ const struct rpc_call_ops *tk_ops)
+{
+ struct rpc_task *task;
+ struct xdr_buf *xbufp = &req->rq_snd_buf;
+ struct rpc_task_setup task_setup_data = {
+ .callback_ops = tk_ops,
+ };
+
+ dprintk("RPC: rpc_run_bc_task req= %p\n", req);
+ /*
+ * Create an rpc_task to send the data
+ */
+ task = rpc_new_task(&task_setup_data);
+ if (!task) {
+ xprt_free_bc_request(req);
+ goto out;
+ }
+ task->tk_rqstp = req;
+
+ /*
+ * Set up the xdr_buf length.
+ * This also indicates that the buffer is XDR encoded already.
+ */
+ xbufp->len = xbufp->head[0].iov_len + xbufp->page_len +
+ xbufp->tail[0].iov_len;
+
+ task->tk_action = call_bc_transmit;
+ atomic_inc(&task->tk_count);
+ BUG_ON(atomic_read(&task->tk_count) != 2);
+ rpc_execute(task);
+
+out:
+ dprintk("RPC: rpc_run_bc_task: task= %p\n", task);
+ return task;
+}
+#endif /* CONFIG_NFS_V4_1 */
+
void
rpc_call_start(struct rpc_task *task)
{
@@ -695,6 +744,19 @@ void rpc_force_rebind(struct rpc_clnt *clnt)
EXPORT_SYMBOL_GPL(rpc_force_rebind);
/*
+ * Restart an (async) RPC call from the call_prepare state.
+ * Usually called from within the exit handler.
+ */
+void
+rpc_restart_call_prepare(struct rpc_task *task)
+{
+ if (RPC_ASSASSINATED(task))
+ return;
+ task->tk_action = rpc_prepare_task;
+}
+EXPORT_SYMBOL_GPL(rpc_restart_call_prepare);
+
+/*
* Restart an (async) RPC call. Usually called from within the
* exit handler.
*/
@@ -1085,7 +1147,7 @@ call_transmit(struct rpc_task *task)
* in order to allow access to the socket to other RPC requests.
*/
call_transmit_status(task);
- if (task->tk_msg.rpc_proc->p_decode != NULL)
+ if (rpc_reply_expected(task))
return;
task->tk_action = rpc_exit_task;
rpc_wake_up_queued_task(&task->tk_xprt->pending, task);
@@ -1120,6 +1182,72 @@ call_transmit_status(struct rpc_task *task)
}
}
+#if defined(CONFIG_NFS_V4_1)
+/*
+ * 5b. Send the backchannel RPC reply. On error, drop the reply. In
+ * addition, disconnect on connectivity errors.
+ */
+static void
+call_bc_transmit(struct rpc_task *task)
+{
+ struct rpc_rqst *req = task->tk_rqstp;
+
+ BUG_ON(task->tk_status != 0);
+ task->tk_status = xprt_prepare_transmit(task);
+ if (task->tk_status == -EAGAIN) {
+ /*
+ * Could not reserve the transport. Try again after the
+ * transport is released.
+ */
+ task->tk_status = 0;
+ task->tk_action = call_bc_transmit;
+ return;
+ }
+
+ task->tk_action = rpc_exit_task;
+ if (task->tk_status < 0) {
+ printk(KERN_NOTICE "RPC: Could not send backchannel reply "
+ "error: %d\n", task->tk_status);
+ return;
+ }
+
+ xprt_transmit(task);
+ xprt_end_transmit(task);
+ dprint_status(task);
+ switch (task->tk_status) {
+ case 0:
+ /* Success */
+ break;
+ case -EHOSTDOWN:
+ case -EHOSTUNREACH:
+ case -ENETUNREACH:
+ case -ETIMEDOUT:
+ /*
+ * Problem reaching the server. Disconnect and let the
+ * forechannel reestablish the connection. The server will
+ * have to retransmit the backchannel request and we'll
+ * reprocess it. Since these ops are idempotent, there's no
+ * need to cache our reply at this time.
+ */
+ printk(KERN_NOTICE "RPC: Could not send backchannel reply "
+ "error: %d\n", task->tk_status);
+ xprt_conditional_disconnect(task->tk_xprt,
+ req->rq_connect_cookie);
+ break;
+ default:
+ /*
+ * We were unable to reply and will have to drop the
+ * request. The server should reconnect and retransmit.
+ */
+ BUG_ON(task->tk_status == -EAGAIN);
+ printk(KERN_NOTICE "RPC: Could not send backchannel reply "
+ "error: %d\n", task->tk_status);
+ break;
+ }
+ rpc_wake_up_queued_task(&req->rq_xprt->pending, task);
+}
+#endif /* CONFIG_NFS_V4_1 */
+
/*
* 6. Sort out the RPC call status
*/
@@ -1130,8 +1258,8 @@ call_status(struct rpc_task *task)
struct rpc_rqst *req = task->tk_rqstp;
int status;
- if (req->rq_received > 0 && !req->rq_bytes_sent)
- task->tk_status = req->rq_received;
+ if (req->rq_reply_bytes_recvd > 0 && !req->rq_bytes_sent)
+ task->tk_status = req->rq_reply_bytes_recvd;
dprint_status(task);
@@ -1248,7 +1376,7 @@ call_decode(struct rpc_task *task)
/*
* Ensure that we see all writes made by xprt_complete_rqst()
- * before it changed req->rq_received.
+ * before it changed req->rq_reply_bytes_recvd.
*/
smp_rmb();
req->rq_rcv_buf.len = req->rq_private_buf.len;
@@ -1289,7 +1417,7 @@ out_retry:
task->tk_status = 0;
/* Note: rpc_verify_header() may have freed the RPC slot */
if (task->tk_rqstp == req) {
- req->rq_received = req->rq_rcv_buf.len = 0;
+ req->rq_reply_bytes_recvd = req->rq_rcv_buf.len = 0;
if (task->tk_client->cl_discrtry)
xprt_conditional_disconnect(task->tk_xprt,
req->rq_connect_cookie);
@@ -1377,13 +1505,14 @@ rpc_verify_header(struct rpc_task *task)
}
if ((len -= 3) < 0)
goto out_overflow;
- p += 1; /* skip XID */
+ p += 1; /* skip XID */
if ((n = ntohl(*p++)) != RPC_REPLY) {
dprintk("RPC: %5u %s: not an RPC reply: %x\n",
- task->tk_pid, __func__, n);
+ task->tk_pid, __func__, n);
goto out_garbage;
}
+
if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) {
if (--len < 0)
goto out_overflow;