If ->request_prepare() detects an error, it sets ->rq_task->tk_status.
This is easy for callers to ignore.
The only caller is xprt_request_enqueue_receive() and it does ignore the
error, as does call_encode() which calls it. This can result in a
request being queued to receive a reply without an allocated receive buffer.
So instead of setting rq_task->tk_status, return an error, and store in
->tk_status only in call_encode();
The call to xprt_request_enqueue_receive() is now earlier in
call_encode(), where the error can still be handled.
Signed-off-by: NeilBrown <neilb@xxxxxxx>
---
include/linux/sunrpc/xprt.h | 5 ++---
net/sunrpc/clnt.c | 6 +++---
net/sunrpc/xprt.c | 23 +++++++++++++++--------
net/sunrpc/xprtsock.c | 4 ++--
4 files changed, 22 insertions(+), 16 deletions(-)
diff --git a/include/linux/sunrpc/xprt.h b/include/linux/sunrpc/xprt.h
index 955ea4d7af0b..400750505222 100644
--- a/include/linux/sunrpc/xprt.h
+++ b/include/linux/sunrpc/xprt.h
@@ -141,7 +141,7 @@ struct rpc_xprt_ops {
void (*connect)(struct rpc_xprt *xprt, struct rpc_task *task);
int (*buf_alloc)(struct rpc_task *task);
void (*buf_free)(struct rpc_task *task);
- void (*prepare_request)(struct rpc_rqst *req);
+ int (*prepare_request)(struct rpc_rqst *req);
int (*send_request)(struct rpc_rqst *req);
void (*wait_for_reply_request)(struct rpc_task *task);
void (*timer)(struct rpc_xprt *xprt, struct rpc_task *task);
@@ -354,10 +354,9 @@ int xprt_reserve_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task);
void xprt_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task);
void xprt_free_slot(struct rpc_xprt *xprt,
struct rpc_rqst *req);
-void xprt_request_prepare(struct rpc_rqst *req);
bool xprt_prepare_transmit(struct rpc_task *task);
void xprt_request_enqueue_transmit(struct rpc_task *task);
-void xprt_request_enqueue_receive(struct rpc_task *task);
+int xprt_request_enqueue_receive(struct rpc_task *task);
void xprt_request_wait_receive(struct rpc_task *task);
void xprt_request_dequeue_xprt(struct rpc_task *task);
bool xprt_request_need_retransmit(struct rpc_task *task);
diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index 8bf2af8546d2..3c7407104d54 100644
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -1858,6 +1858,9 @@ call_encode(struct rpc_task *task)
xprt_request_dequeue_xprt(task);
/* Encode here so that rpcsec_gss can use correct sequence number. */
rpc_xdr_encode(task);
+ /* Add task to reply queue before transmission to avoid races */
+ if (task->tk_status == 0 && rpc_reply_expected(task))
+ task->tk_status = xprt_request_enqueue_receive(task);
/* Did the encode result in an error condition? */
if (task->tk_status != 0) {
/* Was the error nonfatal? */
@@ -1881,9 +1884,6 @@ call_encode(struct rpc_task *task)
return;
}
- /* Add task to reply queue before transmission to avoid races */
- if (rpc_reply_expected(task))
- xprt_request_enqueue_receive(task);
xprt_request_enqueue_transmit(task);
out:
task->tk_action = call_transmit;
diff --git a/net/sunrpc/xprt.c b/net/sunrpc/xprt.c
index 880bfe8dc7f6..73344ffb2692 100644
--- a/net/sunrpc/xprt.c
+++ b/net/sunrpc/xprt.c
@@ -69,10 +69,11 @@
/*
* Local functions
*/
-static void xprt_init(struct rpc_xprt *xprt, struct net *net);
+static void xprt_init(struct rpc_xprt *xprt, struct net *net);
static __be32 xprt_alloc_xid(struct rpc_xprt *xprt);
-static void xprt_destroy(struct rpc_xprt *xprt);
-static void xprt_request_init(struct rpc_task *task);
+static void xprt_destroy(struct rpc_xprt *xprt);
+static void xprt_request_init(struct rpc_task *task);
+static int xprt_request_prepare(struct rpc_rqst *req);
static DEFINE_SPINLOCK(xprt_list_lock);
static LIST_HEAD(xprt_list);
@@ -1143,16 +1144,19 @@ xprt_request_need_enqueue_receive(struct rpc_task *task, struct rpc_rqst *req)
* @task: RPC task
*
*/
-void
+int
xprt_request_enqueue_receive(struct rpc_task *task)
{
struct rpc_rqst *req = task->tk_rqstp;
struct rpc_xprt *xprt = req->rq_xprt;
+ int ret;
if (!xprt_request_need_enqueue_receive(task, req))
- return;
+ return 0;
- xprt_request_prepare(task->tk_rqstp);
+ ret = xprt_request_prepare(task->tk_rqstp);
+ if (ret)
+ return ret;
spin_lock(&xprt->queue_lock);
/* Update the softirq receive buffer */
@@ -1166,6 +1170,7 @@ xprt_request_enqueue_receive(struct rpc_task *task)
/* Turn off autodisconnect */
del_singleshot_timer_sync(&xprt->timer);
+ return 0;
}
/**
@@ -1452,14 +1457,16 @@ xprt_request_dequeue_xprt(struct rpc_task *task)
*
* Calls into the transport layer to do whatever is needed to prepare
* the request for transmission or receive.
+ * Returns error, or zero.
*/
-void
+static int
xprt_request_prepare(struct rpc_rqst *req)
{
struct rpc_xprt *xprt = req->rq_xprt;
if (xprt->ops->prepare_request)
- xprt->ops->prepare_request(req);
+ return xprt->ops->prepare_request(req);
+ return 0;
}
/**
diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c
index b52eaa8a0cda..29683136ed49 100644
--- a/net/sunrpc/xprtsock.c
+++ b/net/sunrpc/xprtsock.c
@@ -822,11 +822,11 @@ static int xs_stream_nospace(struct rpc_rqst *req, bool vm_wait)
return ret;
}
-static void
+static int
xs_stream_prepare_request(struct rpc_rqst *req)
{
xdr_free_bvec(&req->rq_rcv_buf);
- req->rq_task->tk_status = xdr_alloc_bvec(
+ return xdr_alloc_bvec(
&req->rq_rcv_buf, GFP_KERNEL | __GFP_NORETRY | __GFP_NOWARN);
}
--
2.35.1
