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 08afe43118f..703af7ebf6c 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 v1.2.3-70-g09d2 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 + net/sunrpc/Makefile | 1 + net/sunrpc/backchannel_rqst.c | 278 ++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 280 insertions(+) create mode 100644 net/sunrpc/backchannel_rqst.c (limited to 'include/linux/sunrpc/xprt.h') diff --git a/include/linux/sunrpc/xprt.h b/include/linux/sunrpc/xprt.h index 703af7ebf6c..beae030e80b 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 diff --git a/net/sunrpc/Makefile b/net/sunrpc/Makefile index 5369aa369b3..4a01f9684b8 100644 --- a/net/sunrpc/Makefile +++ b/net/sunrpc/Makefile @@ -13,5 +13,6 @@ sunrpc-y := clnt.o xprt.o socklib.o xprtsock.o sched.o \ rpcb_clnt.o timer.o xdr.o \ sunrpc_syms.o cache.o rpc_pipe.o \ svc_xprt.o +sunrpc-$(CONFIG_NFS_V4_1) += backchannel_rqst.o sunrpc-$(CONFIG_PROC_FS) += stats.o sunrpc-$(CONFIG_SYSCTL) += sysctl.o diff --git a/net/sunrpc/backchannel_rqst.c b/net/sunrpc/backchannel_rqst.c new file mode 100644 index 00000000000..f56e18a2349 --- /dev/null +++ b/net/sunrpc/backchannel_rqst.c @@ -0,0 +1,278 @@ +/****************************************************************************** + +(c) 2007 Network Appliance, Inc. All Rights Reserved. +(c) 2009 NetApp. All Rights Reserved. + +NetApp 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. + +******************************************************************************/ + +#include +#include + +#ifdef RPC_DEBUG +#define RPCDBG_FACILITY RPCDBG_TRANS +#endif + +#if defined(CONFIG_NFS_V4_1) + +/* + * Helper routines that track the number of preallocation elements + * on the transport. + */ +static inline int xprt_need_to_requeue(struct rpc_xprt *xprt) +{ + return xprt->bc_alloc_count > 0; +} + +static inline void xprt_inc_alloc_count(struct rpc_xprt *xprt, unsigned int n) +{ + xprt->bc_alloc_count += n; +} + +static inline int xprt_dec_alloc_count(struct rpc_xprt *xprt, unsigned int n) +{ + return xprt->bc_alloc_count -= n; +} + +/* + * Free the preallocated rpc_rqst structure and the memory + * buffers hanging off of it. + */ +static void xprt_free_allocation(struct rpc_rqst *req) +{ + struct xdr_buf *xbufp; + + dprintk("RPC: free allocations for req= %p\n", req); + BUG_ON(test_bit(RPC_BC_PA_IN_USE, &req->rq_bc_pa_state)); + xbufp = &req->rq_private_buf; + free_page((unsigned long)xbufp->head[0].iov_base); + xbufp = &req->rq_snd_buf; + free_page((unsigned long)xbufp->head[0].iov_base); + list_del(&req->rq_bc_pa_list); + kfree(req); +} + +/* + * Preallocate up to min_reqs structures and related buffers for use + * by the backchannel. This function can be called multiple times + * when creating new sessions that use the same rpc_xprt. The + * preallocated buffers are added to the pool of resources used by + * the rpc_xprt. Anyone of these resources may be used used by an + * incoming callback request. It's up to the higher levels in the + * stack to enforce that the maximum number of session slots is not + * being exceeded. + * + * Some callback arguments can be large. For example, a pNFS server + * using multiple deviceids. The list can be unbound, but the client + * has the ability to tell the server the maximum size of the callback + * requests. Each deviceID is 16 bytes, so allocate one page + * for the arguments to have enough room to receive a number of these + * deviceIDs. The NFS client indicates to the pNFS server that its + * callback requests can be up to 4096 bytes in size. + */ +int xprt_setup_backchannel(struct rpc_xprt *xprt, unsigned int min_reqs) +{ + struct page *page_rcv = NULL, *page_snd = NULL; + struct xdr_buf *xbufp = NULL; + struct rpc_rqst *req, *tmp; + struct list_head tmp_list; + int i; + + dprintk("RPC: setup backchannel transport\n"); + + /* + * We use a temporary list to keep track of the preallocated + * buffers. Once we're done building the list we splice it + * into the backchannel preallocation list off of the rpc_xprt + * struct. This helps minimize the amount of time the list + * lock is held on the rpc_xprt struct. It also makes cleanup + * easier in case of memory allocation errors. + */ + INIT_LIST_HEAD(&tmp_list); + for (i = 0; i < min_reqs; i++) { + /* Pre-allocate one backchannel rpc_rqst */ + req = kzalloc(sizeof(struct rpc_rqst), GFP_KERNEL); + if (req == NULL) { + printk(KERN_ERR "Failed to create bc rpc_rqst\n"); + goto out_free; + } + + /* Add the allocated buffer to the tmp list */ + dprintk("RPC: adding req= %p\n", req); + list_add(&req->rq_bc_pa_list, &tmp_list); + + req->rq_xprt = xprt; + INIT_LIST_HEAD(&req->rq_list); + INIT_LIST_HEAD(&req->rq_bc_list); + + /* Preallocate one XDR receive buffer */ + page_rcv = alloc_page(GFP_KERNEL); + if (page_rcv == NULL) { + printk(KERN_ERR "Failed to create bc receive xbuf\n"); + goto out_free; + } + xbufp = &req->rq_rcv_buf; + xbufp->head[0].iov_base = page_address(page_rcv); + xbufp->head[0].iov_len = PAGE_SIZE; + xbufp->tail[0].iov_base = NULL; + xbufp->tail[0].iov_len = 0; + xbufp->page_len = 0; + xbufp->len = PAGE_SIZE; + xbufp->buflen = PAGE_SIZE; + + /* Preallocate one XDR send buffer */ + page_snd = alloc_page(GFP_KERNEL); + if (page_snd == NULL) { + printk(KERN_ERR "Failed to create bc snd xbuf\n"); + goto out_free; + } + + xbufp = &req->rq_snd_buf; + xbufp->head[0].iov_base = page_address(page_snd); + xbufp->head[0].iov_len = 0; + xbufp->tail[0].iov_base = NULL; + xbufp->tail[0].iov_len = 0; + xbufp->page_len = 0; + xbufp->len = 0; + xbufp->buflen = PAGE_SIZE; + } + + /* + * Add the temporary list to the backchannel preallocation list + */ + spin_lock_bh(&xprt->bc_pa_lock); + list_splice(&tmp_list, &xprt->bc_pa_list); + xprt_inc_alloc_count(xprt, min_reqs); + spin_unlock_bh(&xprt->bc_pa_lock); + + dprintk("RPC: setup backchannel transport done\n"); + return 0; + +out_free: + /* + * Memory allocation failed, free the temporary list + */ + list_for_each_entry_safe(req, tmp, &tmp_list, rq_bc_pa_list) + xprt_free_allocation(req); + + dprintk("RPC: setup backchannel transport failed\n"); + return -1; +} +EXPORT_SYMBOL(xprt_setup_backchannel); + +/* + * Destroys the backchannel preallocated structures. + * Since these structures may have been allocated by multiple calls + * to xprt_setup_backchannel, we only destroy up to the maximum number + * of reqs specified by the caller. + * @xprt: the transport holding the preallocated strucures + * @max_reqs the maximum number of preallocated structures to destroy + */ +void xprt_destroy_backchannel(struct rpc_xprt *xprt, unsigned int max_reqs) +{ + struct rpc_rqst *req = NULL, *tmp = NULL; + + dprintk("RPC: destroy backchannel transport\n"); + + BUG_ON(max_reqs == 0); + spin_lock_bh(&xprt->bc_pa_lock); + xprt_dec_alloc_count(xprt, max_reqs); + list_for_each_entry_safe(req, tmp, &xprt->bc_pa_list, rq_bc_pa_list) { + dprintk("RPC: req=%p\n", req); + xprt_free_allocation(req); + if (--max_reqs == 0) + break; + } + spin_unlock_bh(&xprt->bc_pa_lock); + + dprintk("RPC: backchannel list empty= %s\n", + list_empty(&xprt->bc_pa_list) ? "true" : "false"); +} +EXPORT_SYMBOL(xprt_destroy_backchannel); + +/* + * One or more rpc_rqst structure have been preallocated during the + * backchannel setup. Buffer space for the send and private XDR buffers + * has been preallocated as well. Use xprt_alloc_bc_request to allocate + * to this request. Use xprt_free_bc_request to return it. + * + * Return an available rpc_rqst, otherwise NULL if non are available. + */ +struct rpc_rqst *xprt_alloc_bc_request(struct rpc_xprt *xprt) +{ + struct rpc_rqst *req; + + dprintk("RPC: allocate a backchannel request\n"); + spin_lock_bh(&xprt->bc_pa_lock); + if (!list_empty(&xprt->bc_pa_list)) { + req = list_first_entry(&xprt->bc_pa_list, struct rpc_rqst, + rq_bc_pa_list); + list_del(&req->rq_bc_pa_list); + } else { + req = NULL; + } + spin_unlock_bh(&xprt->bc_pa_lock); + + if (req != NULL) { + set_bit(RPC_BC_PA_IN_USE, &req->rq_bc_pa_state); + req->rq_received = 0; + req->rq_bytes_sent = 0; + memcpy(&req->rq_private_buf, &req->rq_rcv_buf, + sizeof(req->rq_private_buf)); + } + dprintk("RPC: backchannel req=%p\n", req); + return req; +} + +/* + * Return the preallocated rpc_rqst structure and XDR buffers + * associated with this rpc_task. + */ +void xprt_free_bc_request(struct rpc_rqst *req) +{ + struct rpc_xprt *xprt = req->rq_xprt; + + dprintk("RPC: free backchannel req=%p\n", req); + + smp_mb__before_clear_bit(); + BUG_ON(!test_bit(RPC_BC_PA_IN_USE, &req->rq_bc_pa_state)); + clear_bit(RPC_BC_PA_IN_USE, &req->rq_bc_pa_state); + smp_mb__after_clear_bit(); + + if (!xprt_need_to_requeue(xprt)) { + /* + * The last remaining session was destroyed while this + * entry was in use. Free the entry and don't attempt + * to add back to the list because there is no need to + * have anymore preallocated entries. + */ + dprintk("RPC: Last session removed req=%p\n", req); + xprt_free_allocation(req); + return; + } + + /* + * Return it to the list of preallocations so that it + * may be reused by a new callback request. + */ + spin_lock_bh(&xprt->bc_pa_lock); + list_add(&req->rq_bc_pa_list, &xprt->bc_pa_list); + spin_unlock_bh(&xprt->bc_pa_lock); +} + +#endif /* CONFIG_NFS_V4_1 */ -- cgit v1.2.3-70-g09d2 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 +++++ net/sunrpc/clnt.c | 117 ++++++++++++++++++++++++++++++++++++++++++- net/sunrpc/stats.c | 6 ++- net/sunrpc/sunrpc.h | 37 ++++++++++++++ net/sunrpc/xprt.c | 38 +++++++++++--- 6 files changed, 203 insertions(+), 9 deletions(-) create mode 100644 net/sunrpc/sunrpc.h (limited to 'include/linux/sunrpc/xprt.h') diff --git a/include/linux/sunrpc/sched.h b/include/linux/sunrpc/sched.h index 177376880fa..401097781fc 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 beae030e80b..55c6c37e249 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 aca3ab6fc14..f3e93b8eb90 100644 --- a/net/sunrpc/clnt.c +++ b/net/sunrpc/clnt.c @@ -36,7 +36,9 @@ #include #include #include +#include +#include "sunrpc.h" #ifdef RPC_DEBUG # define RPCDBG_FACILITY RPCDBG_CALL @@ -63,6 +65,9 @@ static void call_decode(struct rpc_task *task); 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); +#if defined(CONFIG_NFS_V4_1) +static void call_bc_transmit(struct rpc_task *task); +#endif /* CONFIG_NFS_V4_1 */ 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); @@ -613,6 +618,50 @@ 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_bc_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; +} +#endif /* CONFIG_NFS_V4_1 */ + void rpc_call_start(struct rpc_task *task) { @@ -1098,7 +1147,7 @@ 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); @@ -1133,6 +1182,72 @@ call_transmit_status(struct rpc_task *task) } } +#if defined(CONFIG_NFS_V4_1) +/* + * 5b. Send the backchannel RPC reply. On error, drop the reply. In + * addition, disconnect on connectivity errors. + */ +static void +call_bc_transmit(struct rpc_task *task) +{ + struct rpc_rqst *req = task->tk_rqstp; + + BUG_ON(task->tk_status != 0); + task->tk_status = xprt_prepare_transmit(task); + if (task->tk_status == -EAGAIN) { + /* + * Could not reserve the transport. Try again after the + * transport is released. + */ + task->tk_status = 0; + task->tk_action = call_bc_transmit; + return; + } + + task->tk_action = rpc_exit_task; + if (task->tk_status < 0) { + printk(KERN_NOTICE "RPC: Could not send backchannel reply " + "error: %d\n", task->tk_status); + return; + } + + xprt_transmit(task); + xprt_end_transmit(task); + dprint_status(task); + switch (task->tk_status) { + case 0: + /* Success */ + break; + case -EHOSTDOWN: + case -EHOSTUNREACH: + case -ENETUNREACH: + case -ETIMEDOUT: + /* + * Problem reaching the server. Disconnect and let the + * forechannel reestablish the connection. The server will + * have to retransmit the backchannel request and we'll + * reprocess it. Since these ops are idempotent, there's no + * need to cache our reply at this time. + */ + printk(KERN_NOTICE "RPC: Could not send backchannel reply " + "error: %d\n", task->tk_status); + xprt_conditional_disconnect(task->tk_xprt, + req->rq_connect_cookie); + break; + default: + /* + * We were unable to reply and will have to drop the + * request. The server should reconnect and retransmit. + */ + BUG_ON(task->tk_status == -EAGAIN); + printk(KERN_NOTICE "RPC: Could not send backchannel reply " + "error: %d\n", task->tk_status); + break; + } + rpc_wake_up_queued_task(&req->rq_xprt->pending, task); +} +#endif /* CONFIG_NFS_V4_1 */ + /* * 6. Sort out the RPC call status */ diff --git a/net/sunrpc/stats.c b/net/sunrpc/stats.c index 1ef6e46d9da..8487aa0f1f5 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 00000000000..5d9dd742264 --- /dev/null +++ b/net/sunrpc/sunrpc.h @@ -0,0 +1,37 @@ +/****************************************************************************** + +(c) 2008 NetApp. All Rights Reserved. + +NetApp 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 + +static inline int rpc_reply_expected(struct rpc_task *task) +{ + return (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 52739f82df1..0eea2bfe111 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 #include +#include "sunrpc.h" + /* * Local variables */ @@ -873,7 +876,10 @@ 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, @@ -908,8 +914,13 @@ 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); } @@ -982,11 +993,17 @@ 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 is_bc_request; if (!(req = task->tk_rqstp)) return; + + /* Preallocated backchannel request? */ + is_bc_request = bc_prealloc(req); + + xprt = req->rq_xprt; rpc_count_iostats(task); spin_lock_bh(&xprt->transport_lock); xprt->ops->release_xprt(xprt, task); @@ -999,10 +1016,19 @@ 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 (is_bc_request) + return; + memset(req, 0, sizeof(*req)); /* mark unused */ dprintk("RPC: %5u release request %p\n", task->tk_pid, req); -- cgit v1.2.3-70-g09d2 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 ++- net/sunrpc/backchannel_rqst.c | 2 +- net/sunrpc/clnt.c | 8 ++++---- net/sunrpc/stats.c | 2 +- net/sunrpc/xprt.c | 15 ++++++++------- 5 files changed, 16 insertions(+), 14 deletions(-) (limited to 'include/linux/sunrpc/xprt.h') diff --git a/include/linux/sunrpc/xprt.h b/include/linux/sunrpc/xprt.h index 55c6c37e249..1175d58efc2 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 diff --git a/net/sunrpc/backchannel_rqst.c b/net/sunrpc/backchannel_rqst.c index f56e18a2349..5a7d342e308 100644 --- a/net/sunrpc/backchannel_rqst.c +++ b/net/sunrpc/backchannel_rqst.c @@ -230,7 +230,7 @@ struct rpc_rqst *xprt_alloc_bc_request(struct rpc_xprt *xprt) if (req != NULL) { set_bit(RPC_BC_PA_IN_USE, &req->rq_bc_pa_state); - req->rq_received = 0; + req->rq_reply_bytes_recvd = 0; req->rq_bytes_sent = 0; memcpy(&req->rq_private_buf, &req->rq_rcv_buf, sizeof(req->rq_private_buf)); diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c index f3e93b8eb90..5bc2f45bddf 100644 --- a/net/sunrpc/clnt.c +++ b/net/sunrpc/clnt.c @@ -1258,8 +1258,8 @@ call_status(struct rpc_task *task) struct rpc_rqst *req = task->tk_rqstp; int status; - if (req->rq_received > 0 && !req->rq_bytes_sent) - task->tk_status = req->rq_received; + if (req->rq_reply_bytes_recvd > 0 && !req->rq_bytes_sent) + task->tk_status = req->rq_reply_bytes_recvd; dprint_status(task); @@ -1376,7 +1376,7 @@ call_decode(struct rpc_task *task) /* * Ensure that we see all writes made by xprt_complete_rqst() - * before it changed req->rq_received. + * before it changed req->rq_reply_bytes_recvd. */ smp_rmb(); req->rq_rcv_buf.len = req->rq_private_buf.len; @@ -1417,7 +1417,7 @@ out_retry: task->tk_status = 0; /* Note: rpc_verify_header() may have freed the RPC slot */ if (task->tk_rqstp == req) { - req->rq_received = req->rq_rcv_buf.len = 0; + req->rq_reply_bytes_recvd = req->rq_rcv_buf.len = 0; if (task->tk_client->cl_discrtry) xprt_conditional_disconnect(task->tk_xprt, req->rq_connect_cookie); diff --git a/net/sunrpc/stats.c b/net/sunrpc/stats.c index 8487aa0f1f5..1b4e6791ecf 100644 --- a/net/sunrpc/stats.c +++ b/net/sunrpc/stats.c @@ -156,7 +156,7 @@ void rpc_count_iostats(struct rpc_task *task) op_metrics->om_timeouts += task->tk_timeouts; op_metrics->om_bytes_sent += task->tk_bytes_sent; - op_metrics->om_bytes_recv += req->rq_received; + op_metrics->om_bytes_recv += req->rq_reply_bytes_recvd; queue = (long)req->rq_xtime - task->tk_start; if (queue < 0) diff --git a/net/sunrpc/xprt.c b/net/sunrpc/xprt.c index c144611223f..f412a852bc7 100644 --- a/net/sunrpc/xprt.c +++ b/net/sunrpc/xprt.c @@ -806,9 +806,10 @@ void xprt_complete_rqst(struct rpc_task *task, int copied) list_del_init(&req->rq_list); req->rq_private_buf.len = copied; - /* Ensure all writes are done before we update req->rq_received */ + /* Ensure all writes are done before we update */ + /* req->rq_reply_bytes_recvd */ smp_wmb(); - req->rq_received = copied; + req->rq_reply_bytes_recvd = copied; rpc_wake_up_queued_task(&xprt->pending, task); } EXPORT_SYMBOL_GPL(xprt_complete_rqst); @@ -823,7 +824,7 @@ static void xprt_timer(struct rpc_task *task) dprintk("RPC: %5u xprt_timer\n", task->tk_pid); spin_lock_bh(&xprt->transport_lock); - if (!req->rq_received) { + if (!req->rq_reply_bytes_recvd) { if (xprt->ops->timer) xprt->ops->timer(task); } else @@ -845,8 +846,8 @@ int xprt_prepare_transmit(struct rpc_task *task) dprintk("RPC: %5u xprt_prepare_transmit\n", task->tk_pid); spin_lock_bh(&xprt->transport_lock); - if (req->rq_received && !req->rq_bytes_sent) { - err = req->rq_received; + if (req->rq_reply_bytes_recvd && !req->rq_bytes_sent) { + err = req->rq_reply_bytes_recvd; goto out_unlock; } if (!xprt->ops->reserve_xprt(task)) @@ -875,7 +876,7 @@ 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 (!req->rq_reply_bytes_recvd) { if (list_empty(&req->rq_list) && rpc_reply_expected(task)) { /* * Add to the list only if we're expecting a reply @@ -914,7 +915,7 @@ 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 && rpc_reply_expected(task)) { + else if (!req->rq_reply_bytes_recvd && rpc_reply_expected(task)) { /* * Sleep on the pending queue since * we're expecting a reply. -- cgit v1.2.3-70-g09d2