From 56632b5bff5af10eb12d7e9499b5ffcadcb7a7b2 Mon Sep 17 00:00:00 2001 From: Ricardo Labiaga Date: Wed, 1 Apr 2009 09:22:58 -0400 Subject: nfs41: client callback structures Adds new list of rpc_xprt structures, and a readers/writers lock to protect the list. The list is used to preallocate resources for the backchannel during backchannel requests. Callbacks are not expected to cause significant latency, so only one callback will be allowed at this time. It also adds a pointer to the NFS callback service so that requests can be directed to it for processing. New callback members added to svc_serv. The NFSv4.1 callback service will sleep on the svc_serv->svc_cb_waitq until new callback requests arrive. The request will be queued in svc_serv->svc_cb_list. This patch adds this list, the sleep queue and spinlock to svc_serv. [nfs41: NFSv4.1 callback support] Signed-off-by: Ricardo Labiaga Signed-off-by: Benny Halevy --- include/linux/sunrpc/xprt.h | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) (limited to 'include/linux/sunrpc/xprt.h') diff --git a/include/linux/sunrpc/xprt.h b/include/linux/sunrpc/xprt.h index 08afe43118f4..703af7ebf6cf 100644 --- a/include/linux/sunrpc/xprt.h +++ b/include/linux/sunrpc/xprt.h @@ -97,6 +97,12 @@ struct rpc_rqst { unsigned long rq_xtime; /* when transmitted */ int rq_ntrans; + +#if defined(CONFIG_NFS_V4_1) + struct list_head rq_bc_list; /* Callback service list */ + unsigned long rq_bc_pa_state; /* Backchannel prealloc state */ + struct list_head rq_bc_pa_list; /* Backchannel prealloc list */ +#endif /* CONFIG_NFS_V4_1 */ }; #define rq_svec rq_snd_buf.head #define rq_slen rq_snd_buf.len @@ -174,6 +180,14 @@ struct rpc_xprt { spinlock_t reserve_lock; /* lock slot table */ u32 xid; /* Next XID value to use */ struct rpc_task * snd_task; /* Task blocked in send */ +#if defined(CONFIG_NFS_V4_1) + struct svc_serv *bc_serv; /* The RPC service which will */ + /* process the callback */ + spinlock_t bc_pa_lock; /* Protects the preallocated + * items */ + struct list_head bc_pa_list; /* List of preallocated + * backchannel rpc_rqst's */ +#endif /* CONFIG_NFS_V4_1 */ struct list_head recv; struct { @@ -192,6 +206,14 @@ struct rpc_xprt { const char *address_strings[RPC_DISPLAY_MAX]; }; +#if defined(CONFIG_NFS_V4_1) +/* + * Backchannel flags + */ +#define RPC_BC_PA_IN_USE 0x0001 /* Preallocated backchannel */ + /* buffer in use */ +#endif /* CONFIG_NFS_V4_1 */ + struct xprt_create { int ident; /* XPRT_TRANSPORT identifier */ struct sockaddr * srcaddr; /* optional local address */ -- cgit v1.2.2 From fb7a0b9addbdbbb13b7bc02abf55ee524ea19ce1 Mon Sep 17 00:00:00 2001 From: Ricardo Labiaga Date: Wed, 1 Apr 2009 09:23:00 -0400 Subject: nfs41: New backchannel helper routines This patch introduces support to setup the callback xprt on the client side. It allocates/ destroys the preallocated memory structures used to process backchannel requests. At setup time, xprt_setup_backchannel() is invoked to allocate one or more rpc_rqst structures and substructures. This ensures that they are available when an RPC callback arrives. The rpc_rqst structures are maintained in a linked list attached to the rpc_xprt structure. We keep track of the number of allocations so that they can be correctly removed when the channel is destroyed. When an RPC callback arrives, xprt_alloc_bc_request() is invoked to obtain a preallocated rpc_rqst structure. An rpc_xprt structure is returned, and its RPC_BC_PREALLOC_IN_USE bit is set in rpc_xprt->bc_flags. The structure is removed from the the list since it is now in use, and it will be later added back when its user is done with it. After the RPC callback replies, the rpc_rqst structure is returned by invoking xprt_free_bc_request(). This clears the RPC_BC_PREALLOC_IN_USE bit and adds it back to the list, allowing it to be reused by a subsequent RPC callback request. To be consistent with the reception of RPC messages, the backchannel requests should be placed into the 'struct rpc_rqst' rq_rcv_buf, which is then in turn copied to the 'struct rpc_rqst' rq_private_buf. [nfs41: Preallocate rpc_rqst receive buffer for handling callbacks] Signed-off-by: Ricardo Labiaga Signed-off-by: Benny Halevy [Update copyright notice and explain page allocation] Signed-off-by: Ricardo Labiaga Signed-off-by: Benny Halevy --- include/linux/sunrpc/xprt.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/sunrpc/xprt.h') diff --git a/include/linux/sunrpc/xprt.h b/include/linux/sunrpc/xprt.h index 703af7ebf6cf..beae030e80b5 100644 --- a/include/linux/sunrpc/xprt.h +++ b/include/linux/sunrpc/xprt.h @@ -183,6 +183,7 @@ struct rpc_xprt { #if defined(CONFIG_NFS_V4_1) struct svc_serv *bc_serv; /* The RPC service which will */ /* process the callback */ + unsigned int bc_alloc_count; /* Total number of preallocs */ spinlock_t bc_pa_lock; /* Protects the preallocated * items */ struct list_head bc_pa_list; /* List of preallocated -- cgit v1.2.2 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/xprt.h | 12 ++++++++++++ 1 file changed, 12 insertions(+) (limited to 'include/linux/sunrpc/xprt.h') 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 v1.2.2 From dd2b63d049480979016b959abc2d141cdddb1389 Mon Sep 17 00:00:00 2001 From: Ricardo Labiaga Date: Wed, 1 Apr 2009 09:23:28 -0400 Subject: nfs41: Rename rq_received to rq_reply_bytes_recvd The 'rq_received' member of 'struct rpc_rqst' is used to track when we have received a reply to our request. With v4.1, the backchannel can now accept callback requests over the existing connection. Rename this field to make it clear that it is only used for tracking reply bytes and not all bytes received on the connection. Signed-off-by: Ricardo Labiaga Signed-off-by: Benny Halevy --- include/linux/sunrpc/xprt.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'include/linux/sunrpc/xprt.h') diff --git a/include/linux/sunrpc/xprt.h b/include/linux/sunrpc/xprt.h index 55c6c37e249e..1175d58efc2e 100644 --- a/include/linux/sunrpc/xprt.h +++ b/include/linux/sunrpc/xprt.h @@ -67,7 +67,8 @@ struct rpc_rqst { struct rpc_task * rq_task; /* RPC task data */ __be32 rq_xid; /* request XID */ int rq_cong; /* has incremented xprt->cong */ - int rq_received; /* receive completed */ + int rq_reply_bytes_recvd; /* number of reply */ + /* bytes received */ u32 rq_seqno; /* gss seq no. used on req. */ int rq_enc_pages_num; struct page **rq_enc_pages; /* scratch pages for use by -- cgit v1.2.2