fs/smb/smbdirect/connect.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *   Copyright (c) 2012,2016,2017,2025 Stefan Metzmacher
 */

#include "internal.h"
#include "../common/smb2status.h"

static int smbdirect_connect_setup_connection(struct smbdirect_socket *sc);
static int smbdirect_connect_resolve_addr(struct smbdirect_socket *sc,
					  const struct sockaddr *src,
					  const struct sockaddr *dst);
static int smbdirect_connect_rdma_event_handler(struct rdma_cm_id *id,
						struct rdma_cm_event *event);
static int smbdirect_connect_negotiate_start(struct smbdirect_socket *sc);
static void smbdirect_connect_negotiate_send_done(struct ib_cq *cq, struct ib_wc *wc);
static void smbdirect_connect_negotiate_recv_done(struct ib_cq *cq, struct ib_wc *wc);

int smbdirect_connect(struct smbdirect_socket *sc, const struct sockaddr *dst)
{
	const struct sockaddr *src = NULL;
	union {
		struct sockaddr sa;
		struct sockaddr_storage ss;
	} src_addr = {
		.sa = {
			.sa_family = AF_UNSPEC,
		},
	};
	int ret;

	if (sc->first_error)
		return -ENOTCONN;

	if (sc->status != SMBDIRECT_SOCKET_CREATED)
		return -EALREADY;

	if (WARN_ON_ONCE(!sc->rdma.cm_id))
		return -EINVAL;

	src_addr.ss = sc->rdma.cm_id->route.addr.src_addr;
	if (src_addr.sa.sa_family != AF_UNSPEC)
		src = &src_addr.sa;

	smbdirect_log_rdma_event(sc, SMBDIRECT_LOG_INFO,
		"connect: src: %pISpsfc dst: %pISpsfc\n",
		src, dst);

	ret = smbdirect_connect_setup_connection(sc);
	if (ret)
		return ret;

	ret = smbdirect_connect_resolve_addr(sc, src, dst);
	if (ret)
		return ret;

	/*
	 * The rest happens async via smbdirect_connect_rdma_event_handler()
	 * the caller will decide to wait or not.
	 */
	return 0;
}
__SMBDIRECT_EXPORT_SYMBOL__(smbdirect_connect);

static int smbdirect_connect_setup_connection(struct smbdirect_socket *sc)
{
	rdma_lock_handler(sc->rdma.cm_id);
	sc->rdma.cm_id->event_handler = smbdirect_connect_rdma_event_handler;
	rdma_unlock_handler(sc->rdma.cm_id);

	if (SMBDIRECT_CHECK_STATUS_WARN(sc, SMBDIRECT_SOCKET_CREATED))
		return -EINVAL;
	sc->status = SMBDIRECT_SOCKET_RESOLVE_ADDR_NEEDED;

	return 0;
}

static int smbdirect_connect_resolve_addr(struct smbdirect_socket *sc,
					  const struct sockaddr *src,
					  const struct sockaddr *dst)
{
	const struct smbdirect_socket_parameters *sp = &sc->parameters;
	struct sockaddr *src_addr = NULL;
	struct sockaddr *dst_addr = NULL;
	int ret;

	src_addr = (struct sockaddr *)src;
	if (src_addr && src_addr->sa_family == AF_UNSPEC)
		src_addr = NULL;
	dst_addr = (struct sockaddr *)dst;

	if (SMBDIRECT_CHECK_STATUS_WARN(sc, SMBDIRECT_SOCKET_RESOLVE_ADDR_NEEDED))
		return -EINVAL;
	sc->status = SMBDIRECT_SOCKET_RESOLVE_ADDR_RUNNING;
	sc->rdma.expected_event = RDMA_CM_EVENT_ADDR_RESOLVED;
	ret = rdma_resolve_addr(sc->rdma.cm_id, src_addr, dst_addr,
				sp->resolve_addr_timeout_msec);
	if (ret) {
		smbdirect_log_rdma_event(sc, SMBDIRECT_LOG_ERR,
			"rdma_resolve_addr() failed %1pe\n",
			SMBDIRECT_DEBUG_ERR_PTR(ret));
		return ret;
	}

	return 0;
}

static int smbdirect_connect_resolve_route(struct smbdirect_socket *sc)
{
	const struct smbdirect_socket_parameters *sp = &sc->parameters;
	int ret;

	if (SMBDIRECT_CHECK_STATUS_DISCONNECT(sc, SMBDIRECT_SOCKET_RESOLVE_ROUTE_NEEDED))
		return sc->first_error;
	sc->status = SMBDIRECT_SOCKET_RESOLVE_ROUTE_RUNNING;
	sc->rdma.expected_event = RDMA_CM_EVENT_ROUTE_RESOLVED;
	ret = rdma_resolve_route(sc->rdma.cm_id, sp->resolve_route_timeout_msec);
	if (ret) {
		smbdirect_log_rdma_event(sc, SMBDIRECT_LOG_ERR,
			"rdma_resolve_route() failed %1pe\n",
			SMBDIRECT_DEBUG_ERR_PTR(ret));
		return ret;
	}

	return 0;
}

static int smbdirect_connect_rdma_connect(struct smbdirect_socket *sc)
{
	struct smbdirect_socket_parameters *sp = &sc->parameters;
	struct rdma_conn_param conn_param;
	__be32 ird_ord_hdr[2];
	int ret;

	sc->ib.dev = sc->rdma.cm_id->device;

	if (!smbdirect_frwr_is_supported(&sc->ib.dev->attrs)) {
		smbdirect_log_rdma_event(sc, SMBDIRECT_LOG_ERR,
			"Fast Registration Work Requests (FRWR) is not supported device %.*s\n",
			IB_DEVICE_NAME_MAX,
			sc->ib.dev->name);
		smbdirect_log_rdma_event(sc, SMBDIRECT_LOG_ERR,
			"Device capability flags = %llx max_fast_reg_page_list_len = %u\n",
			sc->ib.dev->attrs.device_cap_flags,
			sc->ib.dev->attrs.max_fast_reg_page_list_len);
		return -EPROTONOSUPPORT;
	}

	if (sp->flags & SMBDIRECT_FLAG_PORT_RANGE_ONLY_IB &&
	    !rdma_ib_or_roce(sc->ib.dev, sc->rdma.cm_id->port_num)) {
		smbdirect_log_rdma_event(sc, SMBDIRECT_LOG_ERR,
			"Not IB: device: %.*s IW:%u local: %pISpsfc remote: %pISpsfc\n",
			IB_DEVICE_NAME_MAX,
			sc->ib.dev->name,
			rdma_protocol_iwarp(sc->ib.dev, sc->rdma.cm_id->port_num),
			&sc->rdma.cm_id->route.addr.src_addr,
			&sc->rdma.cm_id->route.addr.dst_addr);
		return -EPROTONOSUPPORT;
	}
	if (sp->flags & SMBDIRECT_FLAG_PORT_RANGE_ONLY_IW &&
	    !rdma_protocol_iwarp(sc->ib.dev, sc->rdma.cm_id->port_num)) {
		smbdirect_log_rdma_event(sc, SMBDIRECT_LOG_ERR,
			"Not IW: device: %.*s IB:%u local: %pISpsfc remote: %pISpsfc\n",
			IB_DEVICE_NAME_MAX,
			sc->ib.dev->name,
			rdma_ib_or_roce(sc->ib.dev, sc->rdma.cm_id->port_num),
			&sc->rdma.cm_id->route.addr.src_addr,
			&sc->rdma.cm_id->route.addr.dst_addr);
		return -EPROTONOSUPPORT;
	}

	smbdirect_log_rdma_event(sc, SMBDIRECT_LOG_INFO,
		"rdma connect: device: %.*s local: %pISpsfc remote: %pISpsfc\n",
		IB_DEVICE_NAME_MAX,
		sc->ib.dev->name,
		&sc->rdma.cm_id->route.addr.src_addr,
		&sc->rdma.cm_id->route.addr.dst_addr);

	sp->max_frmr_depth = min_t(u32, sp->max_frmr_depth,
				   sc->ib.dev->attrs.max_fast_reg_page_list_len);
	sc->mr_io.type = IB_MR_TYPE_MEM_REG;
	if (sc->ib.dev->attrs.kernel_cap_flags & IBK_SG_GAPS_REG)
		sc->mr_io.type = IB_MR_TYPE_SG_GAPS;

	sp->responder_resources = min_t(u8, sp->responder_resources,
					sc->ib.dev->attrs.max_qp_rd_atom);
	smbdirect_log_rdma_mr(sc, SMBDIRECT_LOG_INFO,
		"responder_resources=%d\n",
		sp->responder_resources);

	ret = smbdirect_connection_create_qp(sc);
	if (ret) {
		smbdirect_log_rdma_event(sc, SMBDIRECT_LOG_ERR,
			"smbdirect_connection_create_qp() failed %1pe\n",
			SMBDIRECT_DEBUG_ERR_PTR(ret));
		return ret;
	}

	memset(&conn_param, 0, sizeof(conn_param));
	conn_param.initiator_depth = sp->initiator_depth;
	conn_param.responder_resources = sp->responder_resources;

	/* Need to send IRD/ORD in private data for iWARP */
	if (rdma_protocol_iwarp(sc->ib.dev, sc->rdma.cm_id->port_num)) {
		ird_ord_hdr[0] = cpu_to_be32(conn_param.responder_resources);
		ird_ord_hdr[1] = cpu_to_be32(conn_param.initiator_depth);
		conn_param.private_data = ird_ord_hdr;
		conn_param.private_data_len = sizeof(ird_ord_hdr);
	} else {
		conn_param.private_data = NULL;
		conn_param.private_data_len = 0;
	}

	conn_param.retry_count = SMBDIRECT_RDMA_CM_RETRY;
	conn_param.rnr_retry_count = SMBDIRECT_RDMA_CM_RNR_RETRY;
	conn_param.flow_control = 0;

	if (SMBDIRECT_CHECK_STATUS_DISCONNECT(sc, SMBDIRECT_SOCKET_RDMA_CONNECT_NEEDED))
		return sc->first_error;
	sc->status = SMBDIRECT_SOCKET_RDMA_CONNECT_RUNNING;
	sc->rdma.expected_event = RDMA_CM_EVENT_ESTABLISHED;
	ret = rdma_connect_locked(sc->rdma.cm_id, &conn_param);
	if (ret) {
		smbdirect_log_rdma_event(sc, SMBDIRECT_LOG_ERR,
			"rdma_connect_locked() failed %1pe\n",
			SMBDIRECT_DEBUG_ERR_PTR(ret));
		return ret;
	}

	/*
	 * start with the rdma connect timeout and SMBDIRECT_KEEPALIVE_PENDING
	 * so that the timer will cause a disconnect.
	 */
	INIT_DELAYED_WORK(&sc->idle.timer_work, smbdirect_connection_idle_timer_work);
	sc->idle.keepalive = SMBDIRECT_KEEPALIVE_PENDING;
	mod_delayed_work(sc->workqueues.idle, &sc->idle.timer_work,
			 msecs_to_jiffies(sp->rdma_connect_timeout_msec));

	return 0;
}

static int smbdirect_connect_rdma_event_handler(struct rdma_cm_id *id,
						struct rdma_cm_event *event)
{
	struct smbdirect_socket *sc = id->context;
	u8 peer_initiator_depth;
	u8 peer_responder_resources;
	int ret;

	/*
	 * cma_cm_event_handler() has
	 * lockdep_assert_held(&id_priv->handler_mutex);
	 *
	 * Mutexes are not allowed in interrupts,
	 * and we rely on not being in an interrupt here,
	 * as we might sleep.
	 *
	 * We didn't timeout so we cancel our idle timer,
	 * it will be scheduled again if needed.
	 */
	WARN_ON_ONCE(in_interrupt());
	sc->idle.keepalive = SMBDIRECT_KEEPALIVE_NONE;
	cancel_delayed_work_sync(&sc->idle.timer_work);

	if (event->status || event->event != sc->rdma.expected_event) {
		int lvl = SMBDIRECT_LOG_ERR;

		ret = -ECONNABORTED;

		if (event->event == RDMA_CM_EVENT_REJECTED)
			ret = -ECONNREFUSED;
		if (event->event == RDMA_CM_EVENT_DEVICE_REMOVAL)
			ret = -ENETDOWN;
		if (IS_ERR(SMBDIRECT_DEBUG_ERR_PTR(event->status)))
			ret = event->status;

		if (ret == -ENODEV)
			lvl = SMBDIRECT_LOG_INFO;

		smbdirect_log_rdma_event(sc, lvl,
			"%s (first_error=%1pe, expected=%s) => event=%s status=%d => ret=%1pe\n",
			smbdirect_socket_status_string(sc->status),
			SMBDIRECT_DEBUG_ERR_PTR(sc->first_error),
			rdma_event_msg(sc->rdma.expected_event),
			rdma_event_msg(event->event),
			event->status,
			SMBDIRECT_DEBUG_ERR_PTR(ret));

		smbdirect_socket_schedule_cleanup_lvl(sc,
						      lvl,
						      ret);
		return 0;
	}

	smbdirect_log_rdma_event(sc, SMBDIRECT_LOG_INFO,
		"%s (first_error=%1pe) event=%s\n",
		smbdirect_socket_status_string(sc->status),
		SMBDIRECT_DEBUG_ERR_PTR(sc->first_error),
		rdma_event_msg(event->event));

	if (sc->first_error)
		return 0;

	switch (event->event) {
	case RDMA_CM_EVENT_ADDR_RESOLVED:
		if (SMBDIRECT_CHECK_STATUS_DISCONNECT(sc, SMBDIRECT_SOCKET_RESOLVE_ADDR_RUNNING))
			return 0;
		sc->status = SMBDIRECT_SOCKET_RESOLVE_ROUTE_NEEDED;

		ret = smbdirect_connect_resolve_route(sc);
		if (ret)
			smbdirect_socket_schedule_cleanup(sc, ret);
		return 0;

	case RDMA_CM_EVENT_ROUTE_RESOLVED:
		if (SMBDIRECT_CHECK_STATUS_DISCONNECT(sc, SMBDIRECT_SOCKET_RESOLVE_ROUTE_RUNNING))
			return 0;
		sc->status = SMBDIRECT_SOCKET_RDMA_CONNECT_NEEDED;

		ret = smbdirect_connect_rdma_connect(sc);
		if (ret)
			smbdirect_socket_schedule_cleanup(sc, ret);
		return 0;

	case RDMA_CM_EVENT_ESTABLISHED:
		smbdirect_connection_rdma_established(sc);

		if (SMBDIRECT_CHECK_STATUS_DISCONNECT(sc, SMBDIRECT_SOCKET_RDMA_CONNECT_RUNNING))
			return 0;
		sc->status = SMBDIRECT_SOCKET_NEGOTIATE_NEEDED;

		/*
		 * Here we work around an inconsistency between
		 * iWarp and other devices (at least rxe and irdma using RoCEv2)
		 */
		if (rdma_protocol_iwarp(id->device, id->port_num)) {
			/*
			 * iWarp devices report the peer's values
			 * with the perspective of the peer here.
			 * Tested with siw and irdma (in iwarp mode)
			 * We need to change to our perspective here,
			 * so we need to switch the values.
			 */
			peer_initiator_depth = event->param.conn.responder_resources;
			peer_responder_resources = event->param.conn.initiator_depth;
		} else {
			/*
			 * Non iWarp devices report the peer's values
			 * already changed to our perspective here.
			 * Tested with rxe and irdma (in roce mode).
			 */
			peer_initiator_depth = event->param.conn.initiator_depth;
			peer_responder_resources = event->param.conn.responder_resources;
		}
		smbdirect_connection_negotiate_rdma_resources(sc,
							      peer_initiator_depth,
							      peer_responder_resources,
							      &event->param.conn);

		ret = smbdirect_connect_negotiate_start(sc);
		if (ret)
			smbdirect_socket_schedule_cleanup(sc, ret);
		return 0;

	default:
		break;
	}

	/*
	 * This is an internal error
	 */
	WARN_ON_ONCE(sc->rdma.expected_event != RDMA_CM_EVENT_ESTABLISHED);
	smbdirect_socket_schedule_cleanup(sc, -ECONNABORTED);
	return 0;
}

static int smbdirect_connect_negotiate_start(struct smbdirect_socket *sc)
{
	const struct smbdirect_socket_parameters *sp = &sc->parameters;
	struct smbdirect_recv_io *recv_io = NULL;
	struct smbdirect_send_io *send_io = NULL;
	struct smbdirect_negotiate_req *nreq = NULL;
	int ret;

	if (SMBDIRECT_CHECK_STATUS_DISCONNECT(sc, SMBDIRECT_SOCKET_NEGOTIATE_NEEDED))
		return sc->first_error;
	sc->status = SMBDIRECT_SOCKET_NEGOTIATE_RUNNING;

	ret = smbdirect_connection_create_mem_pools(sc);
	if (ret) {
		smbdirect_log_rdma_event(sc, SMBDIRECT_LOG_ERR,
			"smbdirect_connection_create_mem_pools() failed %1pe\n",
			SMBDIRECT_DEBUG_ERR_PTR(ret));
		goto create_mem_pools_failed;
	}

	/*
	 * There is only a single batch credit
	 */
	atomic_set(&sc->send_io.bcredits.count, 1);

	/*
	 * Initialize the local credits to post
	 * IB_WR_SEND[_WITH_INV].
	 */
	atomic_set(&sc->send_io.lcredits.count, sp->send_credit_target);

	recv_io = smbdirect_connection_get_recv_io(sc);
	if (WARN_ON_ONCE(!recv_io)) {
		ret = -EINVAL;
		smbdirect_log_rdma_event(sc, SMBDIRECT_LOG_ERR,
			"smbdirect_connection_get_recv_io() failed %1pe\n",
			SMBDIRECT_DEBUG_ERR_PTR(ret));
		goto get_recv_io_failed;
	}
	recv_io->cqe.done = smbdirect_connect_negotiate_recv_done;

	send_io = smbdirect_connection_alloc_send_io(sc);
	if (IS_ERR(send_io)) {
		ret = PTR_ERR(send_io);
		smbdirect_log_rdma_event(sc, SMBDIRECT_LOG_ERR,
			"smbdirect_connection_alloc_send_io() failed %1pe\n",
			SMBDIRECT_DEBUG_ERR_PTR(ret));
		goto alloc_send_io_failed;
	}
	send_io->cqe.done = smbdirect_connect_negotiate_send_done;

	nreq = (struct smbdirect_negotiate_req *)send_io->packet;
	nreq->min_version = cpu_to_le16(SMBDIRECT_V1);
	nreq->max_version = cpu_to_le16(SMBDIRECT_V1);
	nreq->reserved = 0;
	nreq->credits_requested = cpu_to_le16(sp->send_credit_target);
	nreq->preferred_send_size = cpu_to_le32(sp->max_send_size);
	nreq->max_receive_size = cpu_to_le32(sp->max_recv_size);
	nreq->max_fragmented_size = cpu_to_le32(sp->max_fragmented_recv_size);

	smbdirect_log_negotiate(sc, SMBDIRECT_LOG_INFO,
		"ReqOut: %s%x, %s%x, %s%u, %s%u, %s%u, %s%u\n",
		"MinVersion=0x",
		le16_to_cpu(nreq->min_version),
		"MaxVersion=0x",
		le16_to_cpu(nreq->max_version),
		"CreditsRequested=",
		le16_to_cpu(nreq->credits_requested),
		"PreferredSendSize=",
		le32_to_cpu(nreq->preferred_send_size),
		"MaxRecvSize=",
		le32_to_cpu(nreq->max_receive_size),
		"MaxFragmentedSize=",
		le32_to_cpu(nreq->max_fragmented_size));

	send_io->sge[0].addr = ib_dma_map_single(sc->ib.dev,
						 nreq,
						 sizeof(*nreq),
						 DMA_TO_DEVICE);
	ret = ib_dma_mapping_error(sc->ib.dev, send_io->sge[0].addr);
	if (ret) {
		smbdirect_log_rdma_event(sc, SMBDIRECT_LOG_ERR,
			"ib_dma_mapping_error() failed %1pe\n",
			SMBDIRECT_DEBUG_ERR_PTR(ret));
		goto dma_mapping_failed;
	}

	send_io->sge[0].length = sizeof(*nreq);
	send_io->sge[0].lkey = sc->ib.pd->local_dma_lkey;
	send_io->num_sge = 1;

	ib_dma_sync_single_for_device(sc->ib.dev,
				      send_io->sge[0].addr,
				      send_io->sge[0].length,
				      DMA_TO_DEVICE);

	smbdirect_log_rdma_send(sc, SMBDIRECT_LOG_INFO,
		"sge addr=0x%llx length=%u lkey=0x%x\n",
		send_io->sge[0].addr,
		send_io->sge[0].length,
		send_io->sge[0].lkey);

	/*
	 * Now post the recv_io buffer in order to get
	 * the negotiate response
	 */
	sc->recv_io.expected = SMBDIRECT_EXPECT_NEGOTIATE_REP;
	ret = smbdirect_connection_post_recv_io(recv_io);
	if (ret) {
		smbdirect_log_rdma_event(sc, SMBDIRECT_LOG_ERR,
			"smbdirect_connection_post_recv_io() failed %1pe\n",
			SMBDIRECT_DEBUG_ERR_PTR(ret));
		goto post_recv_io_failed;
	}

	send_io->wr.next = NULL;
	send_io->wr.wr_cqe = &send_io->cqe;
	send_io->wr.sg_list = send_io->sge;
	send_io->wr.num_sge = send_io->num_sge;
	send_io->wr.opcode = IB_WR_SEND;
	send_io->wr.send_flags = IB_SEND_SIGNALED;

	ret = smbdirect_connection_post_send_wr(sc, &send_io->wr);
	if (ret) {
		/* if we reach here, post send failed */
		smbdirect_log_rdma_send(sc, SMBDIRECT_LOG_ERR,
			"smbdirect_connection_post_send_wr() failed %1pe\n",
			SMBDIRECT_DEBUG_ERR_PTR(ret));
		goto post_send_wr_failed;
	}

	/*
	 * start with the negotiate timeout and SMBDIRECT_KEEPALIVE_PENDING
	 * so that the timer will cause a disconnect.
	 */
	sc->idle.keepalive = SMBDIRECT_KEEPALIVE_PENDING;
	mod_delayed_work(sc->workqueues.idle, &sc->idle.timer_work,
			 msecs_to_jiffies(sp->negotiate_timeout_msec));

	return 0;

post_send_wr_failed:
	/*
	 * ib_dma_unmap_single is called in
	 * smbdirect_connection_free_send_io()
	 */
	smbdirect_connection_free_send_io(send_io);
	/*
	 * recv_io is given to the rdma layer,
	 * we should not put it even on error
	 * nor call smbdirect_connection_destroy_mem_pools()
	 * it will be cleaned up during disconnect.
	 */
	return ret;

post_recv_io_failed:
	/*
	 * ib_dma_unmap_single is called in
	 * smbdirect_connection_free_send_io()
	 */
dma_mapping_failed:
	smbdirect_connection_free_send_io(send_io);

alloc_send_io_failed:
	smbdirect_connection_put_recv_io(recv_io);

get_recv_io_failed:
	smbdirect_connection_destroy_mem_pools(sc);

create_mem_pools_failed:
	return ret;
}

static void smbdirect_connect_negotiate_send_done(struct ib_cq *cq, struct ib_wc *wc)
{
	struct smbdirect_send_io *send_io =
		container_of(wc->wr_cqe, struct smbdirect_send_io, cqe);
	struct smbdirect_socket *sc = send_io->socket;

	smbdirect_log_rdma_send(sc, SMBDIRECT_LOG_INFO,
		"smbdirect_send_io completed. status='%s (%d)', opcode=%d\n",
		ib_wc_status_msg(wc->status), wc->status, wc->opcode);

	/* Note this frees wc->wr_cqe, but not wc */
	smbdirect_connection_free_send_io(send_io);
	atomic_dec(&sc->send_io.pending.count);

	if (unlikely(wc->status != IB_WC_SUCCESS || WARN_ON_ONCE(wc->opcode != IB_WC_SEND))) {
		if (wc->status != IB_WC_WR_FLUSH_ERR)
			smbdirect_log_rdma_send(sc, SMBDIRECT_LOG_ERR,
				"wc->status=%s (%d) wc->opcode=%d\n",
				ib_wc_status_msg(wc->status), wc->status, wc->opcode);
		smbdirect_socket_schedule_cleanup(sc, -ECONNABORTED);
		return;
	}
}

static void smbdirect_connect_negotiate_recv_work(struct work_struct *work);

static void smbdirect_connect_negotiate_recv_done(struct ib_cq *cq, struct ib_wc *wc)
{
	struct smbdirect_recv_io *recv_io =
		container_of(wc->wr_cqe, struct smbdirect_recv_io, cqe);
	struct smbdirect_socket *sc = recv_io->socket;
	unsigned long flags;

	if (unlikely(wc->status != IB_WC_SUCCESS || WARN_ON_ONCE(wc->opcode != IB_WC_RECV))) {
		if (wc->status != IB_WC_WR_FLUSH_ERR)
			smbdirect_log_rdma_recv(sc, SMBDIRECT_LOG_ERR,
				"wc->status=%s (%d) wc->opcode=%d\n",
				ib_wc_status_msg(wc->status), wc->status, wc->opcode);
		goto error;
	}

	smbdirect_log_rdma_recv(sc, SMBDIRECT_LOG_INFO,
		"smbdirect_recv_io completed. status='%s (%d)', opcode=%d\n",
		ib_wc_status_msg(wc->status), wc->status, wc->opcode);

	/*
	 * This is an internal error!
	 */
	if (WARN_ON_ONCE(sc->recv_io.expected != SMBDIRECT_EXPECT_NEGOTIATE_REP))
		goto error;

	/*
	 * Don't reset timer to the keepalive interval in
	 * this will be done in smbdirect_accept_direct_negotiate_recv_work.
	 */

	ib_dma_sync_single_for_cpu(sc->ib.dev,
				   recv_io->sge.addr,
				   recv_io->sge.length,
				   DMA_FROM_DEVICE);

	/*
	 * Only remember recv_io if it has enough bytes,
	 * this gives smbdirect_accept_negotiate_recv_work enough
	 * information in order to disconnect if it was not
	 * valid.
	 */
	sc->recv_io.reassembly.full_packet_received = true;
	if (wc->byte_len >= sizeof(struct smbdirect_negotiate_resp))
		smbdirect_connection_reassembly_append_recv_io(sc, recv_io, 0);
	else
		smbdirect_connection_put_recv_io(recv_io);

	/*
	 * We continue via the workqueue as we may have
	 * complex work that might sleep.
	 *
	 * So we defer further processing of the negotiation
	 * to smbdirect_connect_negotiate_recv_work().
	 */
	spin_lock_irqsave(&sc->connect.lock, flags);
	if (!sc->first_error) {
		INIT_WORK(&sc->connect.work, smbdirect_connect_negotiate_recv_work);
		if (sc->status == SMBDIRECT_SOCKET_NEGOTIATE_RUNNING)
			queue_work(sc->workqueues.connect, &sc->connect.work);
	}
	spin_unlock_irqrestore(&sc->connect.lock, flags);

	return;

error:
	/*
	 * recv_io.posted.refill_work is still disabled,
	 * so smbdirect_connection_put_recv_io() won't
	 * start it.
	 */
	smbdirect_connection_put_recv_io(recv_io);
	smbdirect_socket_schedule_cleanup(sc, -ECONNABORTED);
}

static void smbdirect_connect_negotiate_recv_work(struct work_struct *work)
{
	struct smbdirect_socket *sc =
		container_of(work, struct smbdirect_socket, connect.work);
	struct smbdirect_socket_parameters *sp = &sc->parameters;
	struct smbdirect_recv_io *recv_io;
	struct smbdirect_negotiate_resp *nrep;
	unsigned long flags;
	u16 negotiated_version;
	u16 credits_requested;
	u16 credits_granted;
	u32 status;
	u32 max_readwrite_size;
	u32 preferred_send_size;
	u32 max_receive_size;
	u32 max_fragmented_size;
	int posted;
	int ret;

	if (sc->first_error)
		return;

	/*
	 * make sure we won't start again...
	 */
	disable_work(work);

	/*
	 * Reset timer to the keepalive interval in
	 * order to trigger our next keepalive message.
	 */
	sc->idle.keepalive = SMBDIRECT_KEEPALIVE_NONE;
	mod_delayed_work(sc->workqueues.idle, &sc->idle.timer_work,
			 msecs_to_jiffies(sp->keepalive_interval_msec));

	/*
	 * If smbdirect_connect_negotiate_recv_done() detected an
	 * invalid request we want to disconnect.
	 */
	recv_io = smbdirect_connection_reassembly_first_recv_io(sc);
	if (!recv_io) {
		smbdirect_socket_schedule_cleanup(sc, -ECONNABORTED);
		return;
	}
	spin_lock_irqsave(&sc->recv_io.reassembly.lock, flags);
	sc->recv_io.reassembly.queue_length--;
	list_del(&recv_io->list);
	spin_unlock_irqrestore(&sc->recv_io.reassembly.lock, flags);
	smbdirect_connection_put_recv_io(recv_io);

	if (SMBDIRECT_CHECK_STATUS_DISCONNECT(sc, SMBDIRECT_SOCKET_NEGOTIATE_RUNNING))
		return;

	/*
	 * Note recv_io is already part of the free list,
	 * as we just called smbdirect_connection_put_recv_io(),
	 * but it won't be reused before we call
	 * smbdirect_connection_recv_io_refill() below.
	 */

	nrep = (struct smbdirect_negotiate_resp *)recv_io->packet;
	negotiated_version = le16_to_cpu(nrep->negotiated_version);
	credits_requested = le16_to_cpu(nrep->credits_requested);
	credits_granted = le16_to_cpu(nrep->credits_granted);
	status = le32_to_cpu(nrep->status);
	max_readwrite_size = le32_to_cpu(nrep->max_readwrite_size);
	preferred_send_size = le32_to_cpu(nrep->preferred_send_size);
	max_receive_size = le32_to_cpu(nrep->max_receive_size);
	max_fragmented_size = le32_to_cpu(nrep->max_fragmented_size);

	smbdirect_log_negotiate(sc, SMBDIRECT_LOG_INFO,
		"RepIn: %s%x, %s%x, %s%x, %s%u, %s%u, %s%x, %s%u, %s%u, %s%u, %s%u\n",
		"MinVersion=0x",
		le16_to_cpu(nrep->min_version),
		"MaxVersion=0x",
		le16_to_cpu(nrep->max_version),
		"NegotiatedVersion=0x",
		le16_to_cpu(nrep->negotiated_version),
		"CreditsRequested=",
		le16_to_cpu(nrep->credits_requested),
		"CreditsGranted=",
		le16_to_cpu(nrep->credits_granted),
		"Status=0x",
		le32_to_cpu(nrep->status),
		"MaxReadWriteSize=",
		le32_to_cpu(nrep->max_readwrite_size),
		"PreferredSendSize=",
		le32_to_cpu(nrep->preferred_send_size),
		"MaxRecvSize=",
		le32_to_cpu(nrep->max_receive_size),
		"MaxFragmentedSize=",
		le32_to_cpu(nrep->max_fragmented_size));

	if (negotiated_version != SMBDIRECT_V1) {
		smbdirect_log_rdma_event(sc, SMBDIRECT_LOG_ERR,
			"invalid: negotiated_version=0x%x\n",
			negotiated_version);
		smbdirect_socket_schedule_cleanup(sc, -ECONNREFUSED);
		return;
	}

	if (status != le32_to_cpu(STATUS_SUCCESS)) {
		smbdirect_log_rdma_event(sc, SMBDIRECT_LOG_ERR,
			"invalid: status=0x%x != 0x0\n",
			status);
		smbdirect_socket_schedule_cleanup(sc, -ECONNREFUSED);
		return;
	}

	if (max_receive_size < SMBDIRECT_MIN_RECEIVE_SIZE) {
		smbdirect_log_rdma_event(sc, SMBDIRECT_LOG_ERR,
			"invalid: max_receive_size=%u < %u\n",
			max_receive_size,
			SMBDIRECT_MIN_RECEIVE_SIZE);
		smbdirect_socket_schedule_cleanup(sc, -ECONNABORTED);
		return;
	}

	if (max_fragmented_size < SMBDIRECT_MIN_FRAGMENTED_SIZE) {
		smbdirect_log_rdma_event(sc, SMBDIRECT_LOG_ERR,
			"invalid: max_fragmented_size=%u < %u\n",
			max_fragmented_size,
			SMBDIRECT_MIN_FRAGMENTED_SIZE);
		smbdirect_socket_schedule_cleanup(sc, -ECONNABORTED);
		return;
	}

	if (credits_granted == 0) {
		smbdirect_log_rdma_event(sc, SMBDIRECT_LOG_ERR,
			"invalid: credits_granted == 0\n");
		smbdirect_socket_schedule_cleanup(sc, -ECONNABORTED);
		return;
	}

	if (credits_requested == 0) {
		smbdirect_log_rdma_event(sc, SMBDIRECT_LOG_ERR,
			"invalid: credits_requested == 0\n");
		smbdirect_socket_schedule_cleanup(sc, -ECONNABORTED);
		return;
	}

	if (preferred_send_size > sp->max_recv_size) {
		smbdirect_log_rdma_event(sc, SMBDIRECT_LOG_ERR,
			"invalid: preferred_send_size=%u > max_recv_size=%u\n",
			preferred_send_size,
			sp->max_recv_size);
		smbdirect_socket_schedule_cleanup(sc, -ECONNABORTED);
		return;
	}

	/*
	 * We take the value from the peer, which is checked to be higher than 0,
	 * but we limit it to the max value we support in order to have
	 * the main logic simpler.
	 */
	sc->recv_io.credits.target = credits_requested;
	sc->recv_io.credits.target = min_t(u16, sc->recv_io.credits.target,
					   sp->recv_credit_max);

	/*
	 * At least the value of SMBDIRECT_MIN_RECEIVE_SIZE is used.
	 */
	sp->max_recv_size = min_t(u32, sp->max_recv_size, preferred_send_size);
	sp->max_recv_size = max_t(u32, sp->max_recv_size, SMBDIRECT_MIN_RECEIVE_SIZE);

	/*
	 * We already sent our sp->max_fragmented_recv_size
	 * to the peer, so we can't lower it here any more.
	 *
	 * TODO: but if the peer lowered sp->max_recv_size
	 * we will have to adjust our number of buffers.
	 *
	 * But for now we keep it as the cifs.ko code
	 * worked before.
	 */

	/*
	 * Note nrep->max_receive_size was already checked against
	 * SMBDIRECT_MIN_RECEIVE_SIZE above.
	 */
	sp->max_send_size = min_t(u32, sp->max_send_size, max_receive_size);

	/*
	 * Make sure the resulting max_frmr_depth is at least 1,
	 * which means max_read_write_size needs to be at least PAGE_SIZE.
	 */
	sp->max_read_write_size = min_t(u32, sp->max_frmr_depth * PAGE_SIZE,
					max_readwrite_size);
	if (sp->max_read_write_size < PAGE_SIZE) {
		smbdirect_log_rdma_event(sc, SMBDIRECT_LOG_ERR,
			"invalid: max_readwrite_size=%u < PAGE_SIZE(%lu)\n",
			max_readwrite_size,
			PAGE_SIZE);
		smbdirect_socket_schedule_cleanup(sc, -ECONNABORTED);
		return;
	}
	sp->max_frmr_depth = sp->max_read_write_size / PAGE_SIZE;

	/*
	 * Note nrep->credits_granted was already checked against 0 above.
	 */
	atomic_set(&sc->send_io.credits.count, credits_granted);

	/*
	 * Note nrep->max_fragmented_size was already checked against
	 * SMBDIRECT_MIN_FRAGMENTED_SIZE above.
	 */
	sp->max_fragmented_send_size = max_fragmented_size;

	ret = smbdirect_connection_create_mr_list(sc);
	if (ret) {
		smbdirect_log_rdma_mr(sc, SMBDIRECT_LOG_ERR,
			"smbdirect_connection_create_mr_list() failed %1pe\n",
			SMBDIRECT_DEBUG_ERR_PTR(ret));
		smbdirect_socket_schedule_cleanup(sc, ret);
		return;
	}

	/*
	 * Prepare for receiving data_transfer messages
	 */
	sc->recv_io.reassembly.full_packet_received = true;
	sc->recv_io.expected = SMBDIRECT_EXPECT_DATA_TRANSFER;
	list_for_each_entry(recv_io, &sc->recv_io.free.list, list)
		recv_io->cqe.done = smbdirect_connection_recv_io_done;
	recv_io = NULL;

	/*
	 * We should at least post 1 smbdirect_recv_io!
	 */
	posted = smbdirect_connection_recv_io_refill(sc);
	if (posted < 1) {
		smbdirect_log_rdma_event(sc, SMBDIRECT_LOG_ERR,
			"smbdirect_connection_recv_io_refill() failed %1pe\n",
			SMBDIRECT_DEBUG_ERR_PTR(ret));
		smbdirect_socket_schedule_cleanup(sc, -ECONNABORTED);
		return;
	}

	/*
	 * smbdirect_connection_negotiation_done()
	 * will setup all required things and wake up
	 * the waiter.
	 */
	smbdirect_connection_negotiation_done(sc);
}

int smbdirect_connect_sync(struct smbdirect_socket *sc,
			   const struct sockaddr *dst)
{
	int ret;

	ret = smbdirect_connect(sc, dst);
	if (ret) {
		smbdirect_log_rdma_event(sc, SMBDIRECT_LOG_ERR,
			"smbdirect_connect(%pISpsfc) failed %1pe\n",
			dst, SMBDIRECT_DEBUG_ERR_PTR(ret));
		return ret;
	}

	ret = smbdirect_connection_wait_for_connected(sc);
	if (ret) {
		int lvl = SMBDIRECT_LOG_ERR;

		if (ret == -ENODEV)
			lvl = SMBDIRECT_LOG_INFO;

		smbdirect_log_rdma_event(sc, lvl,
			"wait for smbdirect_connect(%pISpsfc) failed %1pe\n",
			dst, SMBDIRECT_DEBUG_ERR_PTR(ret));
		return ret;
	}

	return 0;
}
__SMBDIRECT_EXPORT_SYMBOL__(smbdirect_connect_sync);