Adds rpc_run_bc_task() which is called by the NFS callback service to
process backchannel requests. It performs similar work to rpc_run_task()
though "schedules" the backchannel task to be executed starting at the
call_trasmit state in the RPC state machine.
It also introduces some miscellaneous updates to the argument validation,
call_transmit, and transport cleanup functions to take into account
that there are now forechannel and backchannel tasks.
Backchannel requests do not carry an RPC message structure, since the
payload has already been XDR encoded using the existing NFSv4 callback
mechanism.
Signed-off-by: Ricardo Labiaga <ricardo.labiaga@xxxxxxxxxx>
Signed-off-by: Benny Halevy <bhalevy@xxxxxxxxxxx>
---
include/linux/sunrpc/sched.h | 2 +
include/linux/sunrpc/xprt.h | 12 +++++++++
net/sunrpc/clnt.c | 52 ++++++++++++++++++++++++++++++++++++++++-
net/sunrpc/stats.c | 6 +++-
net/sunrpc/sunrpc.h | 35 ++++++++++++++++++++++++++++
net/sunrpc/xprt.c | 36 ++++++++++++++++++++++++-----
6 files changed, 133 insertions(+), 10 deletions(-)
create mode 100644 net/sunrpc/sunrpc.h
diff --git a/include/linux/sunrpc/sched.h b/include/linux/sunrpc/sched.h
index 1773768..4010977 100644
--- a/include/linux/sunrpc/sched.h
+++ b/include/linux/sunrpc/sched.h
@@ -210,6 +210,8 @@ struct rpc_wait_queue {
*/
struct rpc_task *rpc_new_task(const struct rpc_task_setup *);
struct rpc_task *rpc_run_task(const struct rpc_task_setup *);
+struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req,
+ const struct rpc_call_ops *ops);
void rpc_put_task(struct rpc_task *);
void rpc_exit_task(struct rpc_task *);
void rpc_release_calldata(const struct rpc_call_ops *, void *);
diff --git a/include/linux/sunrpc/xprt.h b/include/linux/sunrpc/xprt.h
index 035431b..45a92e2 100644
--- a/include/linux/sunrpc/xprt.h
+++ b/include/linux/sunrpc/xprt.h
@@ -215,6 +215,18 @@ struct rpc_xprt {
/* buffer in use */
#endif /* CONFIG_NFS_V4_1 */
+#if defined(CONFIG_NFS_V4_1)
+static inline int bc_prealloc(struct rpc_rqst *req)
+{
+ return test_bit(RPC_BC_PA_IN_USE, &req->rq_bc_pa_state);
+}
+#else
+static inline int bc_prealloc(struct rpc_rqst *req)
+{
+ return 0;
+}
+#endif /* CONFIG_NFS_V4_1 */
+
struct xprt_create {
int ident; /* XPRT_TRANSPORT identifier */
struct sockaddr * srcaddr; /* optional local address */
diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index dd0ff2d..f5418ac 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
@@ -602,6 +604,51 @@ 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_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;
+}
+EXPORT_SYMBOL_GPL(rpc_run_bc_task);
+#endif /* CONFIG_NFS_V4_1 */
+
void
rpc_call_start(struct rpc_task *task)
{
@@ -1094,10 +1141,11 @@ 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);
+ if (task->tk_client != NULL)
+ rpc_wake_up_queued_task(&task->tk_xprt->pending, task);
}
/*
diff --git a/net/sunrpc/stats.c b/net/sunrpc/stats.c
index 50b049c..89dc28e 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 0000000..b462de4
--- /dev/null
+++ b/net/sunrpc/sunrpc.h
@@ -0,0 +1,35 @@
+/******************************************************************************
+
+(c) 2008 Network Appliance, Inc. All Rights Reserved.
+
+Network Appliance 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
+
+#define rpc_reply_expected(task) \
+ (((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 848a7af..cc1e5f2 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
*/
@@ -852,7 +855,10 @@ 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,
@@ -883,8 +889,13 @@ 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);
return;
}
@@ -967,11 +978,15 @@ 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 prealloc;
+ BUG_ON(atomic_read(&task->tk_count) < 0);
if (!(req = task->tk_rqstp))
return;
+ prealloc = bc_prealloc(req); /* Preallocated backchannel request? */
+ xprt = req->rq_xprt;
rpc_count_iostats(task);
spin_lock_bh(&xprt->transport_lock);
xprt->ops->release_xprt(xprt, task);
@@ -984,10 +999,19 @@ 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 (prealloc)
+ return;
+
memset(req, 0, sizeof(*req)); /* mark unused */
dprintk("RPC: %5u release request %p\n", task->tk_pid, req);
--
1.6.0.2
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