From 940e3318c36394939d805e797d7be39ddaaa7911 Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Wed, 9 Nov 2005 21:45:24 -0500 Subject: [PATCH] [PATCH] SUNRPC: don't reencode when looping in call transmit. If the call to xprt_transmit() fails due to socket buffer space exhaustion, we do not need to re-encode the RPC message when we loop back through call_transmit. Re-encoding can actually end up triggering the WARN_ON() in call_decode() if we re-encode something like a read() request and auth->au_rslack has changed. It can also cause us to increment the RPCSEC_GSS sequence number beyond the limits of the allowed window. Signed-off-by: Trond Myklebust Signed-off-by: Linus Torvalds --- net/sunrpc/clnt.c | 32 +++++++++++++++++++++++++++++--- 1 file changed, 29 insertions(+), 3 deletions(-) diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c index 702ede309b0..61c3abeacca 100644 --- a/net/sunrpc/clnt.c +++ b/net/sunrpc/clnt.c @@ -55,6 +55,7 @@ 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); 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); static void call_refreshresult(struct rpc_task *task); static void call_timeout(struct rpc_task *task); @@ -672,6 +673,18 @@ call_allocate(struct rpc_task *task) rpc_exit(task, -ERESTARTSYS); } +static inline int +rpc_task_need_encode(struct rpc_task *task) +{ + return task->tk_rqstp->rq_snd_buf.len == 0; +} + +static inline void +rpc_task_force_reencode(struct rpc_task *task) +{ + task->tk_rqstp->rq_snd_buf.len = 0; +} + /* * 3. Encode arguments of an RPC call */ @@ -867,12 +880,14 @@ call_transmit(struct rpc_task *task) if (task->tk_status != 0) return; /* Encode here so that rpcsec_gss can use correct sequence number. */ - if (task->tk_rqstp->rq_bytes_sent == 0) { + if (rpc_task_need_encode(task)) { + task->tk_rqstp->rq_bytes_sent = 0; call_encode(task); /* Did the encode result in an error condition? */ if (task->tk_status != 0) goto out_nosend; } + task->tk_action = call_transmit_status; xprt_transmit(task); if (task->tk_status < 0) return; @@ -884,6 +899,7 @@ call_transmit(struct rpc_task *task) out_nosend: /* release socket write lock before attempting to handle error */ xprt_abort_transmit(task); + rpc_task_force_reencode(task); } /* @@ -915,7 +931,6 @@ call_status(struct rpc_task *task) break; case -ECONNREFUSED: case -ENOTCONN: - req->rq_bytes_sent = 0; if (clnt->cl_autobind) clnt->cl_port = 0; task->tk_action = call_bind; @@ -937,7 +952,18 @@ call_status(struct rpc_task *task) } /* - * 6a. Handle RPC timeout + * 6a. Handle transmission errors. + */ +static void +call_transmit_status(struct rpc_task *task) +{ + if (task->tk_status != -EAGAIN) + rpc_task_force_reencode(task); + call_status(task); +} + +/* + * 6b. Handle RPC timeout * We do not release the request slot, so we keep using the * same XID for all retransmits. */