From 55ae1aabfb108106dd095de2578ceef1c755a8b8 Mon Sep 17 00:00:00 2001 From: Ricardo Labiaga Date: Wed, 1 Apr 2009 09:23:03 -0400 Subject: nfs41: Add backchannel processing support to RPC state machine 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. Introduce a new transmit state for the client to reply on to backchannel requests. This new state simply reserves the transport and issues the reply. In case of a connection related error, disconnects the transport and drops the reply. It requires the forechannel to re-establish the connection and the server to retransmit the request, as stated in NFSv4.1 section 2.9.2 "Client and Server Transport Behavior". Note: There is no need to loop attempting to reserve the transport. If EAGAIN is returned by xprt_prepare_transmit(), return with tk_status == 0, setting tk_action to call_bc_transmit. rpc_execute() will invoke it again after the task is taken off the sleep queue. [nfs41: rpc_run_bc_task() need not be exported outside RPC module] [nfs41: New call_bc_transmit RPC state] Signed-off-by: Ricardo Labiaga Signed-off-by: Benny Halevy [nfs41: Backchannel: No need to loop in call_bc_transmit()] Signed-off-by: Andy Adamson Signed-off-by: Ricardo Labiaga Signed-off-by: Benny Halevy [rpc_count_iostats incorrectly exits early] Signed-off-by: Ricardo Labiaga Signed-off-by: Benny Halevy [Convert rpc_reply_expected() to inline function] [Remove unnecessary BUG_ON()] [Rename variable] Signed-off-by: Ricardo Labiaga Signed-off-by: Benny Halevy --- include/linux/sunrpc/sched.h | 2 ++ include/linux/sunrpc/xprt.h | 12 ++++++++++++ 2 files changed, 14 insertions(+) (limited to 'include/linux') diff --git a/include/linux/sunrpc/sched.h b/include/linux/sunrpc/sched.h index 177376880fab..401097781fc0 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 beae030e80b5..55c6c37e249e 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 */ -- cgit v1.2.3