This file implements the RDMA transport provider for 9P. It allows
mounts to be performed over iWARP and IB capable network interfaces
and uses the OpenFabrics API to perform I/O.
Signed-off-by: Tom Tucker <[EMAIL PROTECTED]>
Signed-off-by: Latchesar Ionkov <[EMAIL PROTECTED]>
---
net/9p/trans_rdma.c | 1025 +++++++++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 1025 insertions(+), 0 deletions(-)
diff --git a/net/9p/trans_rdma.c b/net/9p/trans_rdma.c
new file mode 100644
index 0000000..f919768
--- /dev/null
+++ b/net/9p/trans_rdma.c
@@ -0,0 +1,1025 @@
+/*
+ * linux/fs/9p/trans_rdma.c
+ *
+ * RDMA transport layer based on the trans_fd.c implementation.
+ *
+ * Copyright (C) 2008 by Tom Tucker <[EMAIL PROTECTED]>
+ * Copyright (C) 2006 by Russ Cox <[EMAIL PROTECTED]>
+ * Copyright (C) 2004-2005 by Latchesar Ionkov <[EMAIL PROTECTED]>
+ * Copyright (C) 2004-2008 by Eric Van Hensbergen <[EMAIL PROTECTED]>
+ * Copyright (C) 1997-2002 by Ron Minnich <[EMAIL PROTECTED]>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to:
+ * Free Software Foundation
+ * 51 Franklin Street, Fifth Floor
+ * Boston, MA 02111-1301 USA
+ *
+ */
+
+#include <linux/in.h>
+#include <linux/module.h>
+#include <linux/net.h>
+#include <linux/ipv6.h>
+#include <linux/kthread.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/un.h>
+#include <linux/uaccess.h>
+#include <linux/inet.h>
+#include <linux/idr.h>
+#include <linux/file.h>
+#include <linux/parser.h>
+#include <net/9p/9p.h>
+#include <net/9p/transport.h>
+#include <rdma/ib_verbs.h>
+#include <rdma/rdma_cm.h>
+#include <rdma/ib_verbs.h>
+
+#define P9_PORT 5640
+#define P9_RDMA_SQ_DEPTH 32
+#define P9_RDMA_RQ_DEPTH 32
+#define P9_RDMA_SEND_SGE 4
+#define P9_RDMA_RECV_SGE 4
+#define P9_RDMA_IRD 0
+#define P9_RDMA_ORD 0
+#define P9_RDMA_TIMEOUT 30000 /* 30 seconds */
+#define P9_RDMA_MAXSIZE (4*4096) /* Min SGE is 4, so we
can
+ * safely advertise a maxsize
+ * of 64k */
+
+#define P9_RDMA_MAX_SGE (P9_RDMA_MAXSIZE >> PAGE_SHIFT)
+/**
+ * struct p9_trans_rdma - RDMA transport instance
+ *
+ * @state: tracks the transport state machine for connection setup and tear
down
+ * @cm_id: The RDMA CM ID
+ * @pd: Protection Domain pointer
+ * @qp: Queue Pair pointer
+ * @cq: Completion Queue pointer
+ * @lkey: The local access only memory region key
+ * @next_tag: The next tag for tracking rpc
+ * @timeout: Number of uSecs to wait for connection management events
+ * @sq_depth: The depth of the Send Queue
+ * @sq_count: Number of WR on the Send Queue
+ * @rq_depth: The depth of the Receive Queue. NB: I _think_ that 9P is
+ * purely req/rpl (i.e. no unaffiliated replies, but I'm not sure, so
+ * I'm allowing this to be tweaked separately.
+ * @addr: The remote peer's address
+ * @req_lock: Protects the active request list
+ * @req_list: List of sent RPC awaiting replies
+ * @send_wait: Wait list when the SQ fills up
+ * @cm_done: Completion event for connection management tracking
+ */
+struct p9_trans_rdma {
+ enum {
+ P9_RDMA_INIT,
+ P9_RDMA_ADDR_RESOLVED,
+ P9_RDMA_ROUTE_RESOLVED,
+ P9_RDMA_CONNECTED,
+ P9_RDMA_FLUSHING,
+ P9_RDMA_CLOSING,
+ P9_RDMA_CLOSED,
+ } state;
+ struct rdma_cm_id *cm_id;
+ struct ib_pd *pd;
+ struct ib_qp *qp;
+ struct ib_cq *cq;
+ struct ib_mr *dma_mr;
+ u32 lkey;
+ atomic_t next_tag;
+ long timeout;
+ int sq_depth;
+ atomic_t sq_count;
+ int rq_depth;
+ struct sockaddr_in addr;
+
+ spinlock_t req_lock;
+ struct list_head req_list;
+
+ wait_queue_head_t send_wait;
+ struct completion cm_done;
+ struct p9_idpool *tagpool;
+};
+
+/**
+ * p9_rdma_context - Keeps track of in-process WR
+ *
+ * @wc_op: Mellanox's broken HW doesn't provide the original WR op
+ * when the CQE completes in error. This forces apps to keep track of
+ * the op themselves. Yes, it's a Pet Peeve of mine ;-)
+ * @busa: Bus address to unmap when the WR completes
+ * @req: Keeps track of requests (send)
+ * @rcall: Keepts track of replies (receive)
+ */
+struct p9_rdma_req;
+struct p9_rdma_context {
+ enum ib_wc_opcode wc_op;
+ dma_addr_t busa;
+ union {
+ struct p9_rdma_req *req;
+ struct p9_fcall *rcall;
+ };
+};
+
+#define P9_RDMA_REQ_FLUSHING 0
+#define P9_RDMA_REQ_COMPLETE 1
+/**
+ * struct p9_rdma_req - tracks the request and reply fcall structures.
+ *
+ * @req_lock: protects req_list
+ * @tcall: request &p9_fcall structure
+ * @rcall: response &p9_fcall structure
+ * @err: error state
+ * @cb: callback for when response is received
+ * @cba: argument to pass to callback
+ * @flush: flag to indicate RPC has been flushed
+ * @req_list: list link for higher level objects to chain requests
+ *
+ */
+struct p9_rdma_req {
+ struct p9_fcall *tcall;
+ struct p9_fcall *rcall;
+ struct completion done;
+ struct list_head list;
+ u16 tag;
+ int err;
+ atomic_t ref;
+ unsigned long flags;
+ spinlock_t lock;
+};
+
+static struct p9_rdma_req *rdma_req_get(void)
+{
+ struct p9_rdma_req *req;
+ req = kzalloc(sizeof *req, GFP_KERNEL);
+ if (req) {
+ atomic_set(&req->ref, 1);
+ init_completion(&req->done);
+ INIT_LIST_HEAD(&req->list);
+ spin_lock_init(&req->lock);
+ req->flags = 0;
+ }
+ return req;
+}
+
+static void rdma_req_put(struct p9_rdma_req *req)
+{
+ if (req && atomic_dec_and_test(&req->ref))
+ kfree(req);
+}
+
+/**
+ * p9_rdma_opts - Collection of mount options
+ *
+ * @sq_depth: The requested depth of the SQ. This really doesn't need
+ * to be any deeper than the number of threads used in the client
+ * @rq_depth: The depth of the RQ. Should be greater than or equal to SQ depth
+ * @timeout: Time to wait in msecs for CM events
+ */
+struct p9_rdma_opts {
+ short port;
+ int sq_depth;
+ int rq_depth;
+ long timeout;
+};
+
+/*
+ * Option Parsing (code inspired by NFS code)
+ */
+
+enum {
+ /* Options that take integer arguments */
+ Opt_port, Opt_rq_depth, Opt_sq_depth, Opt_timeout, Opt_err,
+};
+
+static match_table_t tokens = {
+ {Opt_port, "port=%u"},
+ {Opt_sq_depth, "sq=%u"},
+ {Opt_rq_depth, "rq=%u"},
+ {Opt_timeout, "timeout=%u"},
+ {Opt_err, NULL},
+};
+
+static int
+rdma_rpc(struct p9_trans *t, struct p9_fcall *tc, struct p9_fcall **rc);
+
+/**
+ * parse_options - parse mount options into session structure
+ * @options: options string passed from mount
+ * @opts: transport-specific structure to parse options into
+ *
+ * Returns 0 upon success, -ERRNO upon failure
+ */
+static int parse_opts(char *params, struct p9_rdma_opts *opts)
+{
+ char *p;
+ substring_t args[MAX_OPT_ARGS];
+ int option;
+ char *options;
+ int ret;
+
+ opts->port = P9_PORT;
+ opts->sq_depth = P9_RDMA_SQ_DEPTH;
+ opts->rq_depth = P9_RDMA_RQ_DEPTH;
+ opts->timeout = P9_RDMA_TIMEOUT;
+
+ if (!params)
+ return 0;
+
+ options = kstrdup(params, GFP_KERNEL);
+ if (!options) {
+ P9_DPRINTK(P9_DEBUG_ERROR,
+ "failed to allocate copy of option string\n");
+ return -ENOMEM;
+ }
+
+ while ((p = strsep(&options, ",")) != NULL) {
+ int token;
+ int r;
+ if (!*p)
+ continue;
+ token = match_token(p, tokens, args);
+ r = match_int(&args[0], &option);
+ if (r < 0) {
+ P9_DPRINTK(P9_DEBUG_ERROR,
+ "integer field, but no integer?\n");
+ ret = r;
+ continue;
+ }
+ switch (token) {
+ case Opt_port:
+ opts->port = option;
+ break;
+ case Opt_sq_depth:
+ opts->sq_depth = option;
+ break;
+ case Opt_rq_depth:
+ opts->rq_depth = option;
+ break;
+ case Opt_timeout:
+ opts->timeout = option;
+ break;
+ default:
+ continue;
+ }
+ }
+ /* RQ must be at least as large as the SQ */
+ opts->rq_depth = max(opts->rq_depth, opts->sq_depth);
+ kfree(options);
+ return 0;
+}
+
+/*
+ * Queues the request to the list of active requests on the transport
+ */
+static void enqueue_request(struct p9_trans_rdma *rdma,
+ struct p9_rdma_context *c)
+{
+ struct p9_rdma_req *req = c->req;
+ unsigned long flags;
+ atomic_inc(&req->ref);
+ spin_lock_irqsave(&rdma->req_lock, flags);
+ list_add_tail(&req->list, &rdma->req_list);
+ spin_unlock_irqrestore(&rdma->req_lock, flags);
+}
+
+static void dequeue_request(struct p9_trans_rdma *rdma, struct p9_rdma_req
*req)
+{
+ unsigned long flags;
+ spin_lock_irqsave(&rdma->req_lock, flags);
+ list_del(&req->list);
+ spin_unlock_irqrestore(&rdma->req_lock, flags);
+ rdma_req_put(req);
+}
+
+/*
+ * Searches the list of requests on the transport and returns the request
+ * with the matching tag
+ */
+static struct p9_rdma_req *
+find_req(struct p9_trans_rdma *rdma, u16 tag)
+{
+ unsigned long flags;
+ struct p9_rdma_req *req;
+ int found = 0;
+
+ spin_lock_irqsave(&rdma->req_lock, flags);
+ list_for_each_entry(req, &rdma->req_list, list) {
+ if (req->tag == tag) {
+ found = 1;
+ atomic_inc(&req->ref);
+ break;
+ }
+ }
+ spin_unlock_irqrestore(&rdma->req_lock, flags);
+
+ return found ? req : 0;
+}
+
+static int
+p9_cm_event_handler(struct rdma_cm_id *id,
+ struct rdma_cm_event *event)
+{
+ struct p9_trans *t = id->context;
+ struct p9_trans_rdma *rdma = t->priv;
+ switch (event->event) {
+ case RDMA_CM_EVENT_ADDR_RESOLVED:
+ BUG_ON(rdma->state != P9_RDMA_INIT);
+ rdma->state = P9_RDMA_ADDR_RESOLVED;
+ break;
+
+ case RDMA_CM_EVENT_ROUTE_RESOLVED:
+ BUG_ON(rdma->state != P9_RDMA_ADDR_RESOLVED);
+ rdma->state = P9_RDMA_ROUTE_RESOLVED;
+ break;
+
+ case RDMA_CM_EVENT_ESTABLISHED:
+ BUG_ON(rdma->state != P9_RDMA_ROUTE_RESOLVED);
+ rdma->state = P9_RDMA_CONNECTED;
+ break;
+
+ case RDMA_CM_EVENT_DISCONNECTED:
+ if (rdma)
+ rdma->state = P9_RDMA_CLOSED;
+ if (t)
+ t->status = Disconnected;
+ break;
+
+ case RDMA_CM_EVENT_TIMEWAIT_EXIT:
+ break;
+
+ case RDMA_CM_EVENT_ADDR_CHANGE:
+ case RDMA_CM_EVENT_ROUTE_ERROR:
+ case RDMA_CM_EVENT_DEVICE_REMOVAL:
+ case RDMA_CM_EVENT_MULTICAST_JOIN:
+ case RDMA_CM_EVENT_MULTICAST_ERROR:
+ case RDMA_CM_EVENT_REJECTED:
+ case RDMA_CM_EVENT_CONNECT_REQUEST:
+ case RDMA_CM_EVENT_CONNECT_RESPONSE:
+ case RDMA_CM_EVENT_CONNECT_ERROR:
+ case RDMA_CM_EVENT_ADDR_ERROR:
+ case RDMA_CM_EVENT_UNREACHABLE:
+ t->status = Disconnected;
+ rdma_disconnect(rdma->cm_id);
+ break;
+ default:
+ BUG();
+ }
+ complete(&rdma->cm_done);
+ return 0;
+}
+
+static void process_request(struct p9_trans *trans, struct p9_rdma_req *req)
+{
+ int ecode;
+ struct p9_str *ename;
+
+ if (req->rcall->id == P9_RERROR) {
+ ecode = req->rcall->params.rerror.errno;
+ ename = &req->rcall->params.rerror.error;
+
+ P9_DPRINTK(P9_DEBUG_MUX, "Rerror %.*s\n", ename->len,
+ ename->str);
+
+ if (trans->extended)
+ req->err = -ecode;
+
+ if (!req->err) {
+ req->err = p9_errstr2errno(ename->str, ename->len);
+
+ /* string match failed */
+ if (!req->err) {
+ PRINT_FCALL_ERROR("unknown error", req->rcall);
+ req->err = -ESERVERFAULT;
+ }
+ }
+ } else if (req->tcall && req->rcall->id != req->tcall->id + 1) {
+ P9_DPRINTK(P9_DEBUG_ERROR,
+ "fcall mismatch: expected %d, got %d\n",
+ req->tcall->id + 1, req->rcall->id);
+ if (!req->err)
+ req->err = -EIO;
+ }
+}
+
+static void
+handle_recv(struct p9_trans *trans, struct p9_trans_rdma *rdma,
+ struct p9_rdma_context *c, enum ib_wc_status status, u32 byte_len)
+{
+ struct p9_rdma_req *req;
+ unsigned long flags;
+ int err;
+
+ req = NULL;
+ err = -EIO;
+ ib_dma_unmap_single(rdma->cm_id->device, c->busa, trans->msize,
+ DMA_FROM_DEVICE);
+
+ if (status != IB_WC_SUCCESS)
+ goto err_out;
+
+ err = p9_deserialize_fcall(c->rcall->sdata, byte_len,
+ c->rcall, trans->extended);
+ if (err < 0)
+ goto err_out;
+
+#ifdef CONFIG_NET_9P_DEBUG
+ if ((p9_debug_level&P9_DEBUG_FCALL) == P9_DEBUG_FCALL) {
+ char buf[150];
+
+ p9_printfcall(buf, sizeof(buf), c->rcall,
+ trans->extended);
+ printk(KERN_NOTICE ">>> %p %s\n", trans, buf);
+ }
+#endif
+ req = find_req(rdma, c->rcall->tag);
+ if (req) {
+ spin_lock_irqsave(&req->lock, flags);
+ if (!test_bit(P9_RDMA_REQ_FLUSHING, &req->flags)) {
+ set_bit(P9_RDMA_REQ_COMPLETE, &req->flags);
+ req->rcall = c->rcall;
+ process_request(trans, req);
+ complete(&req->done);
+ }
+ spin_unlock_irqrestore(&req->lock, flags);
+ rdma_req_put(req);
+ }
+ return;
+
+ err_out:
+ P9_DPRINTK(P9_DEBUG_ERROR, "req %p err %d status %d\n",
+ req, err, status);
+ rdma->state = P9_RDMA_FLUSHING;
+ trans->status = Disconnected;
+ return;
+}
+
+static void
+handle_send(struct p9_trans *trans, struct p9_trans_rdma *rdma,
+ struct p9_rdma_context *c, enum ib_wc_status status, u32 byte_len)
+{
+ ib_dma_unmap_single(rdma->cm_id->device,
+ c->busa, c->req->tcall->size,
+ DMA_TO_DEVICE);
+}
+
+static void qp_event_handler(struct ib_event *event, void *context)
+{
+ P9_DPRINTK(P9_DEBUG_ERROR, "QP event %d context %p\n",
+ event->event, context);
+}
+
+static void cq_comp_handler(struct ib_cq *cq, void *cq_context)
+{
+ struct p9_trans *trans = cq_context;
+ struct p9_trans_rdma *rdma = trans->priv;
+ int ret;
+ struct ib_wc wc;
+
+ ib_req_notify_cq(rdma->cq, IB_CQ_NEXT_COMP);
+ while ((ret = ib_poll_cq(cq, 1, &wc)) > 0) {
+ struct p9_rdma_context *c = (void *)wc.wr_id;
+
+ switch (c->wc_op) {
+ case IB_WC_RECV:
+ handle_recv(trans, rdma, c, wc.status, wc.byte_len);
+ break;
+
+ case IB_WC_SEND:
+ handle_send(trans, rdma, c, wc.status, wc.byte_len);
+ atomic_dec(&rdma->sq_count);
+ wake_up(&rdma->send_wait);
+ rdma_req_put(c->req);
+ break;
+
+ default:
+ printk(KERN_ERR "9prdma: unexpected completion type, "
+ "c->wc_op=%d, wc.opcode=%d, status=%d\n",
+ c->wc_op, wc.opcode, wc.status);
+ break;
+ }
+ kfree(c);
+ }
+}
+
+static void cq_event_handler(struct ib_event *e, void *v)
+{
+ P9_DPRINTK(P9_DEBUG_ERROR, "CQ event %d context %p\n",
+ e->event, v);
+}
+
+static void rdma_destroy_trans(struct p9_trans *t)
+{
+ struct p9_trans_rdma *rdma = t->priv;
+
+ if (!rdma)
+ return;
+
+ if (rdma->dma_mr && !IS_ERR(rdma->dma_mr))
+ ib_dereg_mr(rdma->dma_mr);
+
+ if (rdma->qp && !IS_ERR(rdma->qp))
+ ib_destroy_qp(rdma->qp);
+
+ if (rdma->pd && !IS_ERR(rdma->pd))
+ ib_dealloc_pd(rdma->pd);
+
+ if (rdma->cq && !IS_ERR(rdma->cq))
+ ib_destroy_cq(rdma->cq);
+
+ if (rdma->cm_id && !IS_ERR(rdma->cm_id))
+ rdma_destroy_id(rdma->cm_id);
+
+ if (rdma->tagpool)
+ p9_idpool_destroy(rdma->tagpool);
+
+ kfree(rdma);
+}
+
+static int
+post_recv(struct p9_trans *trans, struct p9_rdma_context *c)
+{
+ struct p9_trans_rdma *rdma = trans->priv;
+ struct ib_recv_wr wr, *bad_wr;
+ struct ib_sge sge;
+ int ret;
+
+ c->busa = ib_dma_map_single(rdma->cm_id->device,
+ c->rcall->sdata, trans->msize,
+ DMA_FROM_DEVICE);
+ if (ib_dma_mapping_error(rdma->cm_id->device, c->busa))
+ goto error;
+
+ sge.addr = c->busa;
+ sge.length = trans->msize;
+ sge.lkey = rdma->lkey;
+
+ wr.next = NULL;
+ c->wc_op = IB_WC_RECV;
+ wr.wr_id = (u64)c;
+ wr.sg_list = &sge;
+ wr.num_sge = 1;
+ ret = ib_post_recv(rdma->qp, &wr, &bad_wr);
+ return ret;
+
+ error:
+ P9_DPRINTK(P9_DEBUG_ERROR, "EIO\n");
+ return -EIO;
+}
+
+static struct p9_fcall *alloc_fcall(struct p9_trans *trans)
+{
+ struct p9_fcall *fc;
+ fc = kmalloc(sizeof(struct p9_fcall) + trans->msize, GFP_KERNEL);
+ if (fc)
+ fc->sdata = fc + 1;
+ return fc;
+}
+
+static u16 p9_get_tag(struct p9_trans *trans)
+{
+ int tag;
+ struct p9_trans_rdma *rdma;
+
+ rdma = trans->priv;
+ tag = p9_idpool_get(rdma->tagpool);
+ if (tag < 0)
+ return P9_NOTAG;
+ else
+ return (u16) tag;
+}
+
+static void p9_put_tag(struct p9_trans *trans, u16 tag)
+{
+ struct p9_trans_rdma *rdma;
+
+ rdma = trans->priv;
+ if (tag != P9_NOTAG && p9_idpool_check(tag, rdma->tagpool))
+ p9_idpool_put(tag, rdma->tagpool);
+}
+
+static int send_request(struct p9_trans *trans, struct p9_rdma_context *c)
+{
+ struct p9_trans_rdma *rdma = trans->priv;
+ struct ib_send_wr wr, *bad_wr;
+ struct ib_sge sge;
+
+ c->busa = ib_dma_map_single(rdma->cm_id->device,
+ c->req->tcall->sdata, c->req->tcall->size,
+ DMA_TO_DEVICE);
+ if (ib_dma_mapping_error(rdma->cm_id->device, c->busa))
+ goto error;
+
+#ifdef CONFIG_NET_9P_DEBUG
+ if ((p9_debug_level&P9_DEBUG_FCALL) == P9_DEBUG_FCALL) {
+ char buf[150];
+
+ p9_printfcall(buf, sizeof(buf), c->req->tcall, trans->extended);
+ printk(KERN_NOTICE "<<< %p %s\n", trans, buf);
+ }
+#endif
+ sge.addr = c->busa;
+ sge.length = c->req->tcall->size;
+ sge.lkey = rdma->lkey;
+
+ wr.next = NULL;
+ c->wc_op = IB_WC_SEND;
+ wr.wr_id = (u64)c;
+ wr.opcode = IB_WR_SEND;
+ wr.send_flags = IB_SEND_SIGNALED;
+ wr.sg_list = &sge;
+ wr.num_sge = 1;
+
+ if (atomic_inc_return(&rdma->sq_count) >= rdma->sq_depth)
+ wait_event_interruptible
+ (rdma->send_wait,
+ (atomic_read(&rdma->sq_count) < rdma->sq_depth));
+
+ return ib_post_send(rdma->qp, &wr, &bad_wr);
+
+ error:
+ P9_DPRINTK(P9_DEBUG_ERROR, "EIO\n");
+ return -EIO;
+}
+
+static void flush_request(struct p9_trans *trans, struct p9_rdma_req *req)
+{
+ struct p9_trans_rdma *rdma = trans->priv;
+ struct p9_fcall *tc;
+ struct p9_fcall *rc;
+ unsigned long flags;
+ int err;
+
+ /* Check if we received a response despite being interrupted. */
+ spin_lock_irqsave(&req->lock, flags);
+ if (!test_bit(P9_RDMA_REQ_COMPLETE, &req->flags))
+ set_bit(P9_RDMA_REQ_FLUSHING, &req->flags);
+ spin_unlock_irqrestore(&req->lock, flags);
+ if (!test_bit(P9_RDMA_REQ_FLUSHING, &req->flags))
+ goto out;
+
+ tc = p9_create_tflush(req->tag);
+ if (!tc) {
+ rdma->state = P9_RDMA_FLUSHING;
+ goto out;
+ }
+
+ clear_thread_flag(TIF_SIGPENDING);
+ err = rdma_rpc(trans, tc, &rc);
+ kfree(tc);
+out:
+ return;
+}
+
+/**
+ * rdma_rpc- sends 9P request and waits until a response is available.
+ * The function can be interrupted.
+ * @t: transport data
+ * @tc: request to be sent
+ * @rc: pointer where a pointer to the response is stored
+ *
+ */
+static int
+rdma_rpc(struct p9_trans *t, struct p9_fcall *tc, struct p9_fcall **rc)
+{
+ int err = -ENOMEM, sigpending;
+ u16 tag;
+ struct p9_rdma_req *req;
+ struct p9_trans_rdma *rdma;
+ struct p9_rdma_context *req_context = NULL;
+ struct p9_rdma_context *rpl_context = NULL;
+ unsigned long flags;
+
+ if (t && t->status != Disconnected)
+ rdma = t->priv;
+ else
+ return -EREMOTEIO;
+
+ /* Initialize the request */
+ req = rdma_req_get();
+ if (!req)
+ goto err_close_0;
+ req->tcall = tc;
+ if (req->tcall->id == P9_TVERSION)
+ tag = P9_NOTAG;
+ else
+ tag = p9_get_tag(t);
+
+ req->tag = tag;
+ p9_set_tag(req->tcall, tag);
+
+ /* Allocate an fcall for the reply */
+ rpl_context = kmalloc(sizeof *rpl_context, GFP_KERNEL);
+ if (!rpl_context)
+ goto err_close_1;
+
+ rpl_context->rcall = alloc_fcall(t);
+ if (!rpl_context->rcall) {
+ kfree(rpl_context);
+ goto err_close_1;
+ }
+
+ /*
+ * Post a receive buffer for this request. We don't know
+ * which request this reply buffer will end up servicing, but
+ * we allocate it here to ensure that there is a receive
+ * buffer available for every request
+ */
+ err = post_recv(t, rpl_context);
+ if (err) {
+ kfree(rpl_context->rcall);
+ kfree(rpl_context);
+ goto err_close_1;
+ }
+
+ /* Post the request */
+ req_context = kmalloc(sizeof *req_context, GFP_KERNEL);
+ if (!req_context)
+ goto err_close_1;
+ req_context->req = req;
+ enqueue_request(rdma, req_context);
+ atomic_inc(&req->ref);
+ err = send_request(t, req_context);
+ if (err) {
+ dequeue_request(rdma, req);
+ rdma_req_put(req);
+ kfree(req_context);
+ goto err_close_1;
+ }
+
+ sigpending = 0;
+ if (signal_pending(current)) {
+ sigpending = 1;
+ clear_thread_flag(TIF_SIGPENDING);
+ }
+
+ /* Wait for the response */
+ err = wait_for_completion_interruptible(&req->done);
+
+ /* Take request off the active queue */
+ dequeue_request(rdma, req);
+
+ /* If not, we need to flush request at the server. */
+ if (err == -ERESTARTSYS && rdma->state == P9_RDMA_CONNECTED &&
+ tc->id != P9_TFLUSH) {
+ flush_request(t, req);
+ sigpending = 1;
+ }
+
+ if (sigpending) {
+ spin_lock_irqsave(¤t->sighand->siglock, flags);
+ recalc_sigpending();
+ spin_unlock_irqrestore(¤t->sighand->siglock, flags);
+ }
+
+ /* If we got disconnected while waiting, return an error */
+ if (rdma->state != P9_RDMA_CONNECTED) {
+ P9_DPRINTK(P9_DEBUG_ERROR, "EIO\n");
+ err = -EIO;
+ goto err_close_1;
+ }
+
+ if (rc)
+ *rc = req->rcall;
+ else
+ kfree(req->rcall);
+
+ /* Return the RPC request's error if there is one */
+ if (req->err < 0)
+ err = req->err;
+
+ rdma_req_put(req);
+ p9_put_tag(t, tag);
+ return err;
+
+ err_close_1:
+ rdma_req_put(req);
+ p9_put_tag(t, tag);
+
+ err_close_0:
+ spin_lock_irqsave(&rdma->req_lock, flags);
+ if (rdma->state < P9_RDMA_CLOSING) {
+ rdma->state = P9_RDMA_CLOSING;
+ spin_unlock_irqrestore(&rdma->req_lock, flags);
+ rdma_disconnect(rdma->cm_id);
+ } else
+ spin_unlock_irqrestore(&rdma->req_lock, flags);
+ return err;
+}
+
+static void rdma_close(struct p9_trans *trans)
+{
+ struct p9_trans_rdma *rdma = trans->priv;
+ if (!rdma)
+ return;
+
+ trans->status = Disconnected;
+ rdma_disconnect(rdma->cm_id);
+ rdma_destroy_trans(trans);
+}
+
+/**
+ * alloc_trans - Allocate and initialize the rdma transport structure
+ * @msize: MTU
+ * @dotu: Extension attribute
+ * @opts: Mount options structure
+ */
+static struct p9_trans *
+alloc_trans(int msize, unsigned char dotu, struct p9_rdma_opts *opts)
+{
+ struct p9_trans *trans;
+ struct p9_trans_rdma *rdma;
+
+ trans = kmalloc(sizeof(struct p9_trans), GFP_KERNEL);
+ if (!trans)
+ return NULL;
+
+ trans->msize = msize;
+ trans->extended = dotu;
+ trans->rpc = rdma_rpc;
+ trans->close = rdma_close;
+
+ rdma = trans->priv = kzalloc(sizeof(struct p9_trans_rdma), GFP_KERNEL);
+ if (!rdma) {
+ kfree(trans);
+ return NULL;
+ }
+
+ rdma->sq_depth = opts->sq_depth;
+ rdma->rq_depth = opts->rq_depth;
+ rdma->timeout = opts->timeout;
+ spin_lock_init(&rdma->req_lock);
+ INIT_LIST_HEAD(&rdma->req_list);
+ init_waitqueue_head(&rdma->send_wait);
+ init_completion(&rdma->cm_done);
+ atomic_set(&rdma->sq_count, 0);
+ atomic_set(&rdma->next_tag, 1);
+
+ trans->priv = rdma;
+
+ return trans;
+}
+
+/**
+ * trans_create_rdma - Transport method for creating atransport instance
+ * @addr: IP address string
+ * @args: Mount options string
+ * @msize: Max message size
+ * @dotu: Protocol extension flag
+ */
+static struct p9_trans *
+rdma_create_trans(const char *addr, char *args, int msize, unsigned char dotu)
+{
+ int err;
+ struct p9_trans *trans;
+ struct p9_rdma_opts opts;
+ struct p9_trans_rdma *rdma;
+ struct rdma_conn_param conn_param;
+ struct ib_qp_init_attr qp_attr;
+ struct ib_device_attr devattr;
+
+ /* Parse the transport specific mount options */
+ err = parse_opts(args, &opts);
+ if (err < 0)
+ return ERR_PTR(err);
+
+ /* Create and initialize the RDMA transport structure */
+ trans = alloc_trans(msize, dotu, &opts);
+ if (!trans)
+ return ERR_PTR(-ENOMEM);
+
+ /* Create the RDMA CM ID */
+ rdma = trans->priv;
+ rdma->cm_id = rdma_create_id(p9_cm_event_handler, trans, RDMA_PS_TCP);
+ if (IS_ERR(rdma->cm_id))
+ goto error;
+
+ /* Resolve the server's address */
+ rdma->addr.sin_family = AF_INET;
+ rdma->addr.sin_addr.s_addr = in_aton(addr);
+ rdma->addr.sin_port = htons(opts.port);
+ err = rdma_resolve_addr(rdma->cm_id, NULL,
+ (struct sockaddr *)&rdma->addr,
+ rdma->timeout);
+ if (err)
+ goto error;
+ wait_for_completion_interruptible(&rdma->cm_done);
+ if (rdma->state != P9_RDMA_ADDR_RESOLVED)
+ goto error;
+
+ /* Resolve the route to the server */
+ err = rdma_resolve_route(rdma->cm_id, rdma->timeout);
+ if (err)
+ goto error;
+ wait_for_completion_interruptible(&rdma->cm_done);
+ if (rdma->state != P9_RDMA_ROUTE_RESOLVED)
+ goto error;
+
+ /* Query the device attributes */
+ err = ib_query_device(rdma->cm_id->device, &devattr);
+ if (err)
+ goto error;
+
+ /* Create the Completion Queue */
+ rdma->cq = ib_create_cq(rdma->cm_id->device, cq_comp_handler,
+ cq_event_handler, trans,
+ opts.sq_depth + opts.rq_depth + 1, 0);
+ if (IS_ERR(rdma->cq))
+ goto error;
+ ib_req_notify_cq(rdma->cq, IB_CQ_NEXT_COMP);
+
+ /* Create the Protection Domain */
+ rdma->pd = ib_alloc_pd(rdma->cm_id->device);
+ if (IS_ERR(rdma->pd))
+ goto error;
+
+ /* Cache the DMA lkey in the transport */
+ rdma->dma_mr = NULL;
+ if (0 == (devattr.device_cap_flags & IB_DEVICE_LOCAL_DMA_LKEY)) {
+ rdma->dma_mr = ib_get_dma_mr(rdma->pd, IB_ACCESS_LOCAL_WRITE);
+ if (IS_ERR(rdma->dma_mr))
+ goto error;
+ rdma->lkey = rdma->dma_mr->lkey;
+ } else
+ rdma->lkey = rdma->cm_id->device->local_dma_lkey;
+
+ /* Create the Queue Pair */
+ memset(&qp_attr, 0, sizeof qp_attr);
+ qp_attr.event_handler = qp_event_handler;
+ qp_attr.qp_context = trans;
+ qp_attr.cap.max_send_wr = opts.sq_depth;
+ qp_attr.cap.max_recv_wr = opts.rq_depth;
+ qp_attr.cap.max_send_sge = P9_RDMA_SEND_SGE;
+ qp_attr.cap.max_recv_sge = P9_RDMA_RECV_SGE;
+ qp_attr.sq_sig_type = IB_SIGNAL_REQ_WR;
+ qp_attr.qp_type = IB_QPT_RC;
+ qp_attr.send_cq = rdma->cq;
+ qp_attr.recv_cq = rdma->cq;
+ err = rdma_create_qp(rdma->cm_id, rdma->pd, &qp_attr);
+ if (err)
+ goto error;
+ rdma->qp = rdma->cm_id->qp;
+
+ /* Request a connection */
+ memset(&conn_param, 0, sizeof(conn_param));
+ conn_param.private_data = NULL;
+ conn_param.private_data_len = 0;
+ conn_param.responder_resources = P9_RDMA_IRD;
+ conn_param.initiator_depth = P9_RDMA_ORD;
+ err = rdma_connect(rdma->cm_id, &conn_param);
+ if (err)
+ goto error;
+ wait_for_completion_interruptible(&rdma->cm_done);
+ if (rdma->state != P9_RDMA_CONNECTED)
+ goto error;
+
+ rdma->tagpool = p9_idpool_create();
+ if (IS_ERR(rdma->tagpool)) {
+ rdma->tagpool = NULL;
+ goto error;
+ }
+
+ return trans;
+
+error:
+ rdma_destroy_trans(trans);
+ return ERR_PTR(-ENOTCONN);
+}
+
+static struct p9_trans_module p9_rdma_trans = {
+ .name = "rdma",
+ .maxsize = P9_RDMA_MAXSIZE,
+ .def = 0,
+ .create = rdma_create_trans,
+};
+
+/**
+ * p9_trans_rdma_init - Register the 9P RDMA transport driver
+ */
+static int __init p9_trans_rdma_init(void)
+{
+ v9fs_register_trans(&p9_rdma_trans);
+ return 0;
+}
+
+static void __exit p9_trans_rdma_exit(void)
+{
+ v9fs_unregister_trans(&p9_rdma_trans);
+}
+
+module_init(p9_trans_rdma_init);
+module_exit(p9_trans_rdma_exit);
+
+MODULE_AUTHOR("Tom Tucker <[EMAIL PROTECTED]>");
+MODULE_DESCRIPTION("RDMA Transport for 9P");
+MODULE_LICENSE("Dual BSD/GPL");
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