To support the server-side of an NFSv4.1 backchannel on RDMA connections, add a transport class that enables backward direction messages on an existing forward channel connection.
Signed-off-by: Chuck Lever <[email protected]> --- include/linux/sunrpc/xprt.h | 1 net/sunrpc/xprt.c | 1 net/sunrpc/xprtrdma/svc_rdma_backchannel.c | 219 ++++++++++++++++++++++++++++ net/sunrpc/xprtrdma/svc_rdma_transport.c | 14 +- net/sunrpc/xprtrdma/transport.c | 31 +++- net/sunrpc/xprtrdma/xprt_rdma.h | 11 + 6 files changed, 263 insertions(+), 14 deletions(-) diff --git a/include/linux/sunrpc/xprt.h b/include/linux/sunrpc/xprt.h index 69ef5b3..7637ccd 100644 --- a/include/linux/sunrpc/xprt.h +++ b/include/linux/sunrpc/xprt.h @@ -85,6 +85,7 @@ struct rpc_rqst { __u32 * rq_buffer; /* XDR encode buffer */ size_t rq_callsize, rq_rcvsize; + void * rq_privdata; /* xprt-specific per-rqst data */ size_t rq_xmit_bytes_sent; /* total bytes sent */ size_t rq_reply_bytes_recvd; /* total reply bytes */ /* received */ diff --git a/net/sunrpc/xprt.c b/net/sunrpc/xprt.c index 2e98f4a..37edea6 100644 --- a/net/sunrpc/xprt.c +++ b/net/sunrpc/xprt.c @@ -1425,3 +1425,4 @@ void xprt_put(struct rpc_xprt *xprt) if (atomic_dec_and_test(&xprt->count)) xprt_destroy(xprt); } +EXPORT_SYMBOL_GPL(xprt_put); diff --git a/net/sunrpc/xprtrdma/svc_rdma_backchannel.c b/net/sunrpc/xprtrdma/svc_rdma_backchannel.c index 69dab71..3534e75 100644 --- a/net/sunrpc/xprtrdma/svc_rdma_backchannel.c +++ b/net/sunrpc/xprtrdma/svc_rdma_backchannel.c @@ -84,3 +84,222 @@ out_notfound: goto out_unlock; } + +/* Server-side transport endpoint wants a whole page for its send + * buffer. The client RPC code constructs the RPC header in this + * buffer before it invokes ->send_request. + * + * Returns NULL if there was a temporary allocation failure. + */ +static void * +xprt_rdma_bc_allocate(struct rpc_task *task, size_t size) +{ + struct rpc_rqst *rqst = task->tk_rqstp; + struct svc_rdma_op_ctxt *ctxt; + struct svcxprt_rdma *rdma; + struct svc_xprt *sxprt; + struct page *page; + + /* Prevent an infinite loop: don't return NULL */ + if (size > PAGE_SIZE) + WARN_ONCE(1, "svcrdma: bc buffer request too large (size %zu)\n", + size); + + page = alloc_page(RPCRDMA_DEF_GFP); + if (!page) + return NULL; + + sxprt = rqst->rq_xprt->bc_xprt; + rdma = container_of(sxprt, struct svcxprt_rdma, sc_xprt); + ctxt = svc_rdma_get_context(rdma); + if (!ctxt) { + put_page(page); + return NULL; + } + + rqst->rq_privdata = ctxt; + ctxt->pages[0] = page; + ctxt->count = 1; + return page_address(page); +} + +static void +xprt_rdma_bc_free(void *buffer) +{ + /* No-op: ctxt and page have already been freed. */ +} + +static int +rpcrdma_bc_send_request(struct svcxprt_rdma *rdma, struct rpc_rqst *rqst) +{ + struct rpc_xprt *xprt = rqst->rq_xprt; + struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt); + struct rpcrdma_msg *headerp = (struct rpcrdma_msg *)rqst->rq_buffer; + struct svc_rdma_op_ctxt *ctxt; + int rc; + + /* Space in the send buffer for an RPC/RDMA header is reserved + * via xprt->tsh_size */ + headerp->rm_xid = rqst->rq_xid; + headerp->rm_vers = rpcrdma_version; + headerp->rm_credit = cpu_to_be32(r_xprt->rx_buf.rb_bc_max_requests); + headerp->rm_type = rdma_msg; + headerp->rm_body.rm_chunks[0] = xdr_zero; + headerp->rm_body.rm_chunks[1] = xdr_zero; + headerp->rm_body.rm_chunks[2] = xdr_zero; + +#ifdef SVCRDMA_BACKCHANNEL_DEBUG + pr_info("%s: %*ph\n", __func__, 64, rqst->rq_buffer); +#endif + + ctxt = (struct svc_rdma_op_ctxt *)rqst->rq_privdata; + rc = svc_rdma_bc_post_send(rdma, ctxt, &rqst->rq_snd_buf); + if (rc) + goto drop_connection; + return rc; + +drop_connection: + dprintk("svcrdma: failed to send bc call\n"); + svc_rdma_put_context(ctxt, 1); + xprt_disconnect_done(xprt); + return -ENOTCONN; +} + +/* Send an RPC call on the passive end of a transport + * connection. + */ +static int +xprt_rdma_bc_send_request(struct rpc_task *task) +{ + struct rpc_rqst *rqst = task->tk_rqstp; + struct svc_xprt *sxprt = rqst->rq_xprt->bc_xprt; + struct svcxprt_rdma *rdma; + u32 len; + + dprintk("svcrdma: sending bc call with xid: %08x\n", + be32_to_cpu(rqst->rq_xid)); + + if (!mutex_trylock(&sxprt->xpt_mutex)) { + rpc_sleep_on(&sxprt->xpt_bc_pending, task, NULL); + if (!mutex_trylock(&sxprt->xpt_mutex)) + return -EAGAIN; + rpc_wake_up_queued_task(&sxprt->xpt_bc_pending, task); + } + + len = -ENOTCONN; + rdma = container_of(sxprt, struct svcxprt_rdma, sc_xprt); + if (!test_bit(XPT_DEAD, &sxprt->xpt_flags)) + len = rpcrdma_bc_send_request(rdma, rqst); + + mutex_unlock(&sxprt->xpt_mutex); + + if (len < 0) + return len; + return 0; +} + +static void +xprt_rdma_bc_close(struct rpc_xprt *xprt) +{ + dprintk("svcrdma: %s: xprt %p\n", __func__, xprt); +} + +static void +xprt_rdma_bc_put(struct rpc_xprt *xprt) +{ + dprintk("svcrdma: %s: xprt %p\n", __func__, xprt); + + xprt_free(xprt); + module_put(THIS_MODULE); +} + +static struct rpc_xprt_ops xprt_rdma_bc_procs = { + .reserve_xprt = xprt_reserve_xprt_cong, + .release_xprt = xprt_release_xprt_cong, + .alloc_slot = xprt_alloc_slot, + .release_request = xprt_release_rqst_cong, + .buf_alloc = xprt_rdma_bc_allocate, + .buf_free = xprt_rdma_bc_free, + .send_request = xprt_rdma_bc_send_request, + .set_retrans_timeout = xprt_set_retrans_timeout_def, + .close = xprt_rdma_bc_close, + .destroy = xprt_rdma_bc_put, + .print_stats = xprt_rdma_print_stats +}; + +static const struct rpc_timeout xprt_rdma_bc_timeout = { + .to_initval = 60 * HZ, + .to_maxval = 60 * HZ, +}; + +/* It shouldn't matter if the number of backchannel session slots + * doesn't match the number of RPC/RDMA credits. That just means + * one or the other will have extra slots that aren't used. + */ +static struct rpc_xprt * +xprt_setup_rdma_bc(struct xprt_create *args) +{ + struct rpc_xprt *xprt; + struct rpcrdma_xprt *new_xprt; + + if (args->addrlen > sizeof(xprt->addr)) { + dprintk("RPC: %s: address too large\n", __func__); + return ERR_PTR(-EBADF); + } + + xprt = xprt_alloc(args->net, sizeof(*new_xprt), + RPCRDMA_MAX_BC_REQUESTS, + RPCRDMA_MAX_BC_REQUESTS); + if (xprt == NULL) { + dprintk("RPC: %s: couldn't allocate rpc_xprt\n", + __func__); + return ERR_PTR(-ENOMEM); + } + + xprt->timeout = &xprt_rdma_bc_timeout; + xprt_set_bound(xprt); + xprt_set_connected(xprt); + xprt->bind_timeout = RPCRDMA_BIND_TO; + xprt->reestablish_timeout = RPCRDMA_INIT_REEST_TO; + xprt->idle_timeout = RPCRDMA_IDLE_DISC_TO; + + xprt->prot = XPRT_TRANSPORT_BC_RDMA; + xprt->tsh_size = RPCRDMA_HDRLEN_MIN / sizeof(__be32); + xprt->ops = &xprt_rdma_bc_procs; + + memcpy(&xprt->addr, args->dstaddr, args->addrlen); + xprt->addrlen = args->addrlen; + xprt_rdma_format_addresses(xprt, (struct sockaddr *)&xprt->addr); + xprt->resvport = 0; + + xprt->max_payload = xprt_rdma_max_inline_read; + + new_xprt = rpcx_to_rdmax(xprt); + new_xprt->rx_buf.rb_bc_max_requests = xprt->max_reqs; + + xprt_get(xprt); + args->bc_xprt->xpt_bc_xprt = xprt; + xprt->bc_xprt = args->bc_xprt; + + if (!try_module_get(THIS_MODULE)) + goto out_fail; + + /* Final put for backchannel xprt is in __svc_rdma_free */ + xprt_get(xprt); + return xprt; + +out_fail: + xprt_rdma_free_addresses(xprt); + args->bc_xprt->xpt_bc_xprt = NULL; + xprt_put(xprt); + xprt_free(xprt); + return ERR_PTR(-EINVAL); +} + +struct xprt_class xprt_rdma_bc = { + .list = LIST_HEAD_INIT(xprt_rdma_bc.list), + .name = "rdma backchannel", + .owner = THIS_MODULE, + .ident = XPRT_TRANSPORT_BC_RDMA, + .setup = xprt_setup_rdma_bc, +}; diff --git a/net/sunrpc/xprtrdma/svc_rdma_transport.c b/net/sunrpc/xprtrdma/svc_rdma_transport.c index ed5dd93..8aea4ad 100644 --- a/net/sunrpc/xprtrdma/svc_rdma_transport.c +++ b/net/sunrpc/xprtrdma/svc_rdma_transport.c @@ -1212,12 +1212,14 @@ static void __svc_rdma_free(struct work_struct *work) { struct svcxprt_rdma *rdma = container_of(work, struct svcxprt_rdma, sc_work); - dprintk("svcrdma: svc_rdma_free(%p)\n", rdma); + struct svc_xprt *xprt = &rdma->sc_xprt; + + dprintk("svcrdma: %s(%p)\n", __func__, rdma); /* We should only be called from kref_put */ - if (atomic_read(&rdma->sc_xprt.xpt_ref.refcount) != 0) + if (atomic_read(&xprt->xpt_ref.refcount) != 0) pr_err("svcrdma: sc_xprt still in use? (%d)\n", - atomic_read(&rdma->sc_xprt.xpt_ref.refcount)); + atomic_read(&xprt->xpt_ref.refcount)); /* * Destroy queued, but not processed read completions. Note @@ -1252,6 +1254,12 @@ static void __svc_rdma_free(struct work_struct *work) pr_err("svcrdma: dma still in use? (%d)\n", atomic_read(&rdma->sc_dma_used)); + /* Final put of backchannel client transport */ + if (xprt->xpt_bc_xprt) { + xprt_put(xprt->xpt_bc_xprt); + xprt->xpt_bc_xprt = NULL; + } + /* De-allocate fastreg mr */ rdma_dealloc_frmr_q(rdma); diff --git a/net/sunrpc/xprtrdma/transport.c b/net/sunrpc/xprtrdma/transport.c index 8c545f7..43d25f4 100644 --- a/net/sunrpc/xprtrdma/transport.c +++ b/net/sunrpc/xprtrdma/transport.c @@ -63,7 +63,7 @@ */ static unsigned int xprt_rdma_slot_table_entries = RPCRDMA_DEF_SLOT_TABLE; -static unsigned int xprt_rdma_max_inline_read = RPCRDMA_DEF_INLINE; + unsigned int xprt_rdma_max_inline_read = RPCRDMA_DEF_INLINE; static unsigned int xprt_rdma_max_inline_write = RPCRDMA_DEF_INLINE; static unsigned int xprt_rdma_inline_write_padding; static unsigned int xprt_rdma_memreg_strategy = RPCRDMA_FRMR; @@ -143,12 +143,8 @@ static struct ctl_table sunrpc_table[] = { #endif -#define RPCRDMA_BIND_TO (60U * HZ) -#define RPCRDMA_INIT_REEST_TO (5U * HZ) -#define RPCRDMA_MAX_REEST_TO (30U * HZ) -#define RPCRDMA_IDLE_DISC_TO (5U * 60 * HZ) - -static struct rpc_xprt_ops xprt_rdma_procs; /* forward reference */ +static struct rpc_xprt_ops xprt_rdma_procs; +extern struct xprt_class xprt_rdma_bc; static void xprt_rdma_format_addresses4(struct rpc_xprt *xprt, struct sockaddr *sap) @@ -174,7 +170,7 @@ xprt_rdma_format_addresses6(struct rpc_xprt *xprt, struct sockaddr *sap) xprt->address_strings[RPC_DISPLAY_NETID] = RPCBIND_NETID_RDMA6; } -static void +void xprt_rdma_format_addresses(struct rpc_xprt *xprt, struct sockaddr *sap) { char buf[128]; @@ -203,7 +199,7 @@ xprt_rdma_format_addresses(struct rpc_xprt *xprt, struct sockaddr *sap) xprt->address_strings[RPC_DISPLAY_PROTO] = "rdma"; } -static void +void xprt_rdma_free_addresses(struct rpc_xprt *xprt) { unsigned int i; @@ -499,7 +495,7 @@ xprt_rdma_allocate(struct rpc_task *task, size_t size) if (req == NULL) return NULL; - flags = GFP_NOIO | __GFP_NOWARN; + flags = RPCRDMA_DEF_GFP; if (RPC_IS_SWAPPER(task)) flags = __GFP_MEMALLOC | GFP_NOWAIT | __GFP_NOWARN; @@ -639,7 +635,7 @@ drop_connection: return -ENOTCONN; /* implies disconnect */ } -static void xprt_rdma_print_stats(struct rpc_xprt *xprt, struct seq_file *seq) +void xprt_rdma_print_stats(struct rpc_xprt *xprt, struct seq_file *seq) { struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt); long idle_time = 0; @@ -740,6 +736,11 @@ void xprt_rdma_cleanup(void) rpcrdma_destroy_wq(); frwr_destroy_recovery_wq(); + + rc = xprt_unregister_transport(&xprt_rdma_bc); + if (rc) + dprintk("RPC: %s: xprt_unregister(bc) returned %i\n", + __func__, rc); } int xprt_rdma_init(void) @@ -763,6 +764,14 @@ int xprt_rdma_init(void) return rc; } + rc = xprt_register_transport(&xprt_rdma_bc); + if (rc) { + xprt_unregister_transport(&xprt_rdma); + rpcrdma_destroy_wq(); + frwr_destroy_recovery_wq(); + return rc; + } + dprintk("RPCRDMA Module Init, register RPC RDMA transport\n"); dprintk("Defaults:\n"); diff --git a/net/sunrpc/xprtrdma/xprt_rdma.h b/net/sunrpc/xprtrdma/xprt_rdma.h index 3895574..d83abbc 100644 --- a/net/sunrpc/xprtrdma/xprt_rdma.h +++ b/net/sunrpc/xprtrdma/xprt_rdma.h @@ -55,6 +55,11 @@ #define RDMA_RESOLVE_TIMEOUT (5000) /* 5 seconds */ #define RDMA_CONNECT_RETRY_MAX (2) /* retries if no listener backlog */ +#define RPCRDMA_BIND_TO (60U * HZ) +#define RPCRDMA_INIT_REEST_TO (5U * HZ) +#define RPCRDMA_MAX_REEST_TO (30U * HZ) +#define RPCRDMA_IDLE_DISC_TO (5U * 60 * HZ) + /* * Interface Adapter -- one per transport instance */ @@ -148,6 +153,8 @@ rdmab_to_msg(struct rpcrdma_regbuf *rb) return (struct rpcrdma_msg *)rb->rg_base; } +#define RPCRDMA_DEF_GFP (GFP_NOIO | __GFP_NOWARN) + /* * struct rpcrdma_rep -- this structure encapsulates state required to recv * and complete a reply, asychronously. It needs several pieces of @@ -516,6 +523,10 @@ int rpcrdma_marshal_req(struct rpc_rqst *); /* RPC/RDMA module init - xprtrdma/transport.c */ +extern unsigned int xprt_rdma_max_inline_read; +void xprt_rdma_format_addresses(struct rpc_xprt *xprt, struct sockaddr *sap); +void xprt_rdma_free_addresses(struct rpc_xprt *xprt); +void xprt_rdma_print_stats(struct rpc_xprt *xprt, struct seq_file *seq); int xprt_rdma_init(void); void xprt_rdma_cleanup(void); -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
