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author | Linus Torvalds <torvalds@linux-foundation.org> | 2016-01-23 18:45:06 -0800 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-01-23 18:45:06 -0800 |
commit | 048ccca8c1c8f583deec3367d7df521bb1f542ae (patch) | |
tree | efa882c88f658f711d63581a3063203c63682338 /net/sunrpc/xprtrdma/svc_rdma_backchannel.c | |
parent | b3e27d5d4a29bcc8e057b496d5ef5194addaaac0 (diff) | |
parent | 34356f64ac0df2326fa50e2d4bca6f7c03ed16c1 (diff) | |
download | lwn-048ccca8c1c8f583deec3367d7df521bb1f542ae.tar.gz lwn-048ccca8c1c8f583deec3367d7df521bb1f542ae.zip |
Merge tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dledford/rdma
Pull rdma updates from Doug Ledford:
"Initial roundup of 4.5 merge window patches
- Remove usage of ib_query_device and instead store attributes in
ib_device struct
- Move iopoll out of block and into lib, rename to irqpoll, and use
in several places in the rdma stack as our new completion queue
polling library mechanism. Update the other block drivers that
already used iopoll to use the new mechanism too.
- Replace the per-entry GID table locks with a single GID table lock
- IPoIB multicast cleanup
- Cleanups to the IB MR facility
- Add support for 64bit extended IB counters
- Fix for netlink oops while parsing RDMA nl messages
- RoCEv2 support for the core IB code
- mlx4 RoCEv2 support
- mlx5 RoCEv2 support
- Cross Channel support for mlx5
- Timestamp support for mlx5
- Atomic support for mlx5
- Raw QP support for mlx5
- MAINTAINERS update for mlx4/mlx5
- Misc ocrdma, qib, nes, usNIC, cxgb3, cxgb4, mlx4, mlx5 updates
- Add support for remote invalidate to the iSER driver (pushed
through the RDMA tree due to dependencies, acknowledged by nab)
- Update to NFSoRDMA (pushed through the RDMA tree due to
dependencies, acknowledged by Bruce)"
* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dledford/rdma: (169 commits)
IB/mlx5: Unify CQ create flags check
IB/mlx5: Expose Raw Packet QP to user space consumers
{IB, net}/mlx5: Move the modify QP operation table to mlx5_ib
IB/mlx5: Support setting Ethernet priority for Raw Packet QPs
IB/mlx5: Add Raw Packet QP query functionality
IB/mlx5: Add create and destroy functionality for Raw Packet QP
IB/mlx5: Refactor mlx5_ib_qp to accommodate other QP types
IB/mlx5: Allocate a Transport Domain for each ucontext
net/mlx5_core: Warn on unsupported events of QP/RQ/SQ
net/mlx5_core: Add RQ and SQ event handling
net/mlx5_core: Export transport objects
IB/mlx5: Expose CQE version to user-space
IB/mlx5: Add CQE version 1 support to user QPs and SRQs
IB/mlx5: Fix data validation in mlx5_ib_alloc_ucontext
IB/sa: Fix netlink local service GFP crash
IB/srpt: Remove redundant wc array
IB/qib: Improve ipoib UD performance
IB/mlx4: Advertise RoCE v2 support
IB/mlx4: Create and use another QP1 for RoCEv2
IB/mlx4: Enable send of RoCE QP1 packets with IP/UDP headers
...
Diffstat (limited to 'net/sunrpc/xprtrdma/svc_rdma_backchannel.c')
-rw-r--r-- | net/sunrpc/xprtrdma/svc_rdma_backchannel.c | 371 |
1 files changed, 371 insertions, 0 deletions
diff --git a/net/sunrpc/xprtrdma/svc_rdma_backchannel.c b/net/sunrpc/xprtrdma/svc_rdma_backchannel.c new file mode 100644 index 000000000000..65a7c232a345 --- /dev/null +++ b/net/sunrpc/xprtrdma/svc_rdma_backchannel.c @@ -0,0 +1,371 @@ +/* + * Copyright (c) 2015 Oracle. All rights reserved. + * + * Support for backward direction RPCs on RPC/RDMA (server-side). + */ + +#include <linux/sunrpc/svc_rdma.h> +#include "xprt_rdma.h" + +#define RPCDBG_FACILITY RPCDBG_SVCXPRT + +#undef SVCRDMA_BACKCHANNEL_DEBUG + +int svc_rdma_handle_bc_reply(struct rpc_xprt *xprt, struct rpcrdma_msg *rmsgp, + struct xdr_buf *rcvbuf) +{ + struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt); + struct kvec *dst, *src = &rcvbuf->head[0]; + struct rpc_rqst *req; + unsigned long cwnd; + u32 credits; + size_t len; + __be32 xid; + __be32 *p; + int ret; + + p = (__be32 *)src->iov_base; + len = src->iov_len; + xid = rmsgp->rm_xid; + +#ifdef SVCRDMA_BACKCHANNEL_DEBUG + pr_info("%s: xid=%08x, length=%zu\n", + __func__, be32_to_cpu(xid), len); + pr_info("%s: RPC/RDMA: %*ph\n", + __func__, (int)RPCRDMA_HDRLEN_MIN, rmsgp); + pr_info("%s: RPC: %*ph\n", + __func__, (int)len, p); +#endif + + ret = -EAGAIN; + if (src->iov_len < 24) + goto out_shortreply; + + spin_lock_bh(&xprt->transport_lock); + req = xprt_lookup_rqst(xprt, xid); + if (!req) + goto out_notfound; + + dst = &req->rq_private_buf.head[0]; + memcpy(&req->rq_private_buf, &req->rq_rcv_buf, sizeof(struct xdr_buf)); + if (dst->iov_len < len) + goto out_unlock; + memcpy(dst->iov_base, p, len); + + credits = be32_to_cpu(rmsgp->rm_credit); + if (credits == 0) + credits = 1; /* don't deadlock */ + else if (credits > r_xprt->rx_buf.rb_bc_max_requests) + credits = r_xprt->rx_buf.rb_bc_max_requests; + + cwnd = xprt->cwnd; + xprt->cwnd = credits << RPC_CWNDSHIFT; + if (xprt->cwnd > cwnd) + xprt_release_rqst_cong(req->rq_task); + + ret = 0; + xprt_complete_rqst(req->rq_task, rcvbuf->len); + rcvbuf->len = 0; + +out_unlock: + spin_unlock_bh(&xprt->transport_lock); +out: + return ret; + +out_shortreply: + dprintk("svcrdma: short bc reply: xprt=%p, len=%zu\n", + xprt, src->iov_len); + goto out; + +out_notfound: + dprintk("svcrdma: unrecognized bc reply: xprt=%p, xid=%08x\n", + xprt, be32_to_cpu(xid)); + + goto out_unlock; +} + +/* Send a backwards direction RPC call. + * + * Caller holds the connection's mutex and has already marshaled + * the RPC/RDMA request. + * + * This is similar to svc_rdma_reply, but takes an rpc_rqst + * instead, does not support chunks, and avoids blocking memory + * allocation. + * + * XXX: There is still an opportunity to block in svc_rdma_send() + * if there are no SQ entries to post the Send. This may occur if + * the adapter has a small maximum SQ depth. + */ +static int svc_rdma_bc_sendto(struct svcxprt_rdma *rdma, + struct rpc_rqst *rqst) +{ + struct xdr_buf *sndbuf = &rqst->rq_snd_buf; + struct svc_rdma_op_ctxt *ctxt; + struct svc_rdma_req_map *vec; + struct ib_send_wr send_wr; + int ret; + + vec = svc_rdma_get_req_map(rdma); + ret = svc_rdma_map_xdr(rdma, sndbuf, vec); + if (ret) + goto out_err; + + /* Post a recv buffer to handle the reply for this request. */ + ret = svc_rdma_post_recv(rdma, GFP_NOIO); + if (ret) { + pr_err("svcrdma: Failed to post bc receive buffer, err=%d.\n", + ret); + pr_err("svcrdma: closing transport %p.\n", rdma); + set_bit(XPT_CLOSE, &rdma->sc_xprt.xpt_flags); + ret = -ENOTCONN; + goto out_err; + } + + ctxt = svc_rdma_get_context(rdma); + ctxt->pages[0] = virt_to_page(rqst->rq_buffer); + ctxt->count = 1; + + ctxt->wr_op = IB_WR_SEND; + ctxt->direction = DMA_TO_DEVICE; + ctxt->sge[0].lkey = rdma->sc_pd->local_dma_lkey; + ctxt->sge[0].length = sndbuf->len; + ctxt->sge[0].addr = + ib_dma_map_page(rdma->sc_cm_id->device, ctxt->pages[0], 0, + sndbuf->len, DMA_TO_DEVICE); + if (ib_dma_mapping_error(rdma->sc_cm_id->device, ctxt->sge[0].addr)) { + ret = -EIO; + goto out_unmap; + } + atomic_inc(&rdma->sc_dma_used); + + memset(&send_wr, 0, sizeof(send_wr)); + send_wr.wr_id = (unsigned long)ctxt; + send_wr.sg_list = ctxt->sge; + send_wr.num_sge = 1; + send_wr.opcode = IB_WR_SEND; + send_wr.send_flags = IB_SEND_SIGNALED; + + ret = svc_rdma_send(rdma, &send_wr); + if (ret) { + ret = -EIO; + goto out_unmap; + } + +out_err: + svc_rdma_put_req_map(rdma, vec); + dprintk("svcrdma: %s returns %d\n", __func__, ret); + return ret; + +out_unmap: + svc_rdma_unmap_dma(ctxt); + svc_rdma_put_context(ctxt, 1); + goto out_err; +} + +/* 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_xprt *sxprt = rqst->rq_xprt->bc_xprt; + struct svcxprt_rdma *rdma; + struct page *page; + + rdma = container_of(sxprt, struct svcxprt_rdma, sc_xprt); + + /* Prevent an infinite loop: try to make this case work */ + if (size > PAGE_SIZE) + WARN_ONCE(1, "svcrdma: large bc buffer request (size %zu)\n", + size); + + page = alloc_page(RPCRDMA_DEF_GFP); + if (!page) + return NULL; + + 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; + 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 + + rc = svc_rdma_bc_sendto(rdma, rqst); + if (rc) + goto drop_connection; + return rc; + +drop_connection: + dprintk("svcrdma: failed to send bc call\n"); + 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; + int ret; + + 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); + } + + ret = -ENOTCONN; + rdma = container_of(sxprt, struct svcxprt_rdma, sc_xprt); + if (!test_bit(XPT_DEAD, &sxprt->xpt_flags)) + ret = rpcrdma_bc_send_request(rdma, rqst); + + mutex_unlock(&sxprt->xpt_mutex); + + if (ret < 0) + return ret; + 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) { + 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, +}; |