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-rw-r--r--net/sunrpc/clnt.c117
-rw-r--r--net/sunrpc/stats.c6
-rw-r--r--net/sunrpc/sunrpc.h37
-rw-r--r--net/sunrpc/xprt.c38
4 files changed, 189 insertions, 9 deletions
diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index aca3ab6fc140..f3e93b8eb90f 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)
{
@@ -1098,7 +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);
@@ -1133,6 +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
*/
diff --git a/net/sunrpc/stats.c b/net/sunrpc/stats.c
index 1ef6e46d9da2..8487aa0f1f5a 100644
--- a/net/sunrpc/stats.c
+++ b/net/sunrpc/stats.c
@@ -141,12 +141,14 @@ EXPORT_SYMBOL_GPL(rpc_free_iostats);
void rpc_count_iostats(struct rpc_task *task)
{
struct rpc_rqst *req = task->tk_rqstp;
- struct rpc_iostats *stats = task->tk_client->cl_metrics;
+ struct rpc_iostats *stats;
struct rpc_iostats *op_metrics;
long rtt, execute, queue;
- if (!stats || !req)
+ if (!task->tk_client || !task->tk_client->cl_metrics || !req)
return;
+
+ stats = task->tk_client->cl_metrics;
op_metrics = &stats[task->tk_msg.rpc_proc->p_statidx];
op_metrics->om_ops++;
diff --git a/net/sunrpc/sunrpc.h b/net/sunrpc/sunrpc.h
new file mode 100644
index 000000000000..5d9dd742264b
--- /dev/null
+++ b/net/sunrpc/sunrpc.h
@@ -0,0 +1,37 @@
+/******************************************************************************
+
+(c) 2008 NetApp. All Rights Reserved.
+
+NetApp provides this source code under the GPL v2 License.
+The GPL v2 license is available at
+http://opensource.org/licenses/gpl-license.php.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+******************************************************************************/
+
+/*
+ * Functions and macros used internally by RPC
+ */
+
+#ifndef _NET_SUNRPC_SUNRPC_H
+#define _NET_SUNRPC_SUNRPC_H
+
+static inline int rpc_reply_expected(struct rpc_task *task)
+{
+ return (task->tk_msg.rpc_proc != NULL) &&
+ (task->tk_msg.rpc_proc->p_decode != NULL);
+}
+
+#endif /* _NET_SUNRPC_SUNRPC_H */
+
diff --git a/net/sunrpc/xprt.c b/net/sunrpc/xprt.c
index 52739f82df1e..0eea2bfe111b 100644
--- a/net/sunrpc/xprt.c
+++ b/net/sunrpc/xprt.c
@@ -12,8 +12,9 @@
* - Next, the caller puts together the RPC message, stuffs it into
* the request struct, and calls xprt_transmit().
* - xprt_transmit sends the message and installs the caller on the
- * transport's wait list. At the same time, it installs a timer that
- * is run after the packet's timeout has expired.
+ * transport's wait list. At the same time, if a reply is expected,
+ * it installs a timer that is run after the packet's timeout has
+ * expired.
* - When a packet arrives, the data_ready handler walks the list of
* pending requests for that transport. If a matching XID is found, the
* caller is woken up, and the timer removed.
@@ -46,6 +47,8 @@
#include <linux/sunrpc/clnt.h>
#include <linux/sunrpc/metrics.h>
+#include "sunrpc.h"
+
/*
* Local variables
*/
@@ -873,7 +876,10 @@ void xprt_transmit(struct rpc_task *task)
dprintk("RPC: %5u xprt_transmit(%u)\n", task->tk_pid, req->rq_slen);
if (!req->rq_received) {
- if (list_empty(&req->rq_list)) {
+ if (list_empty(&req->rq_list) && rpc_reply_expected(task)) {
+ /*
+ * Add to the list only if we're expecting a reply
+ */
spin_lock_bh(&xprt->transport_lock);
/* Update the softirq receive buffer */
memcpy(&req->rq_private_buf, &req->rq_rcv_buf,
@@ -908,8 +914,13 @@ void xprt_transmit(struct rpc_task *task)
/* Don't race with disconnect */
if (!xprt_connected(xprt))
task->tk_status = -ENOTCONN;
- else if (!req->rq_received)
+ else if (!req->rq_received && rpc_reply_expected(task)) {
+ /*
+ * Sleep on the pending queue since
+ * we're expecting a reply.
+ */
rpc_sleep_on(&xprt->pending, task, xprt_timer);
+ }
spin_unlock_bh(&xprt->transport_lock);
}
@@ -982,11 +993,17 @@ static void xprt_request_init(struct rpc_task *task, struct rpc_xprt *xprt)
*/
void xprt_release(struct rpc_task *task)
{
- struct rpc_xprt *xprt = task->tk_xprt;
+ struct rpc_xprt *xprt;
struct rpc_rqst *req;
+ int is_bc_request;
if (!(req = task->tk_rqstp))
return;
+
+ /* Preallocated backchannel request? */
+ is_bc_request = bc_prealloc(req);
+
+ xprt = req->rq_xprt;
rpc_count_iostats(task);
spin_lock_bh(&xprt->transport_lock);
xprt->ops->release_xprt(xprt, task);
@@ -999,10 +1016,19 @@ void xprt_release(struct rpc_task *task)
mod_timer(&xprt->timer,
xprt->last_used + xprt->idle_timeout);
spin_unlock_bh(&xprt->transport_lock);
- xprt->ops->buf_free(req->rq_buffer);
+ if (!bc_prealloc(req))
+ xprt->ops->buf_free(req->rq_buffer);
task->tk_rqstp = NULL;
if (req->rq_release_snd_buf)
req->rq_release_snd_buf(req);
+
+ /*
+ * Early exit if this is a backchannel preallocated request.
+ * There is no need to have it added to the RPC slot list.
+ */
+ if (is_bc_request)
+ return;
+
memset(req, 0, sizeof(*req)); /* mark unused */
dprintk("RPC: %5u release request %p\n", task->tk_pid, req);
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