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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/infiniband/ulp/rtrs/rtrs-clt.c
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/infiniband/ulp/rtrs/rtrs-clt.c')
-rw-r--r--drivers/infiniband/ulp/rtrs/rtrs-clt.c3180
1 files changed, 3180 insertions, 0 deletions
diff --git a/drivers/infiniband/ulp/rtrs/rtrs-clt.c b/drivers/infiniband/ulp/rtrs/rtrs-clt.c
new file mode 100644
index 000000000..cc07c91f9
--- /dev/null
+++ b/drivers/infiniband/ulp/rtrs/rtrs-clt.c
@@ -0,0 +1,3180 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * RDMA Transport Layer
+ *
+ * Copyright (c) 2014 - 2018 ProfitBricks GmbH. All rights reserved.
+ * Copyright (c) 2018 - 2019 1&1 IONOS Cloud GmbH. All rights reserved.
+ * Copyright (c) 2019 - 2020 1&1 IONOS SE. All rights reserved.
+ */
+
+#undef pr_fmt
+#define pr_fmt(fmt) KBUILD_MODNAME " L" __stringify(__LINE__) ": " fmt
+
+#include <linux/module.h>
+#include <linux/rculist.h>
+#include <linux/random.h>
+
+#include "rtrs-clt.h"
+#include "rtrs-log.h"
+#include "rtrs-clt-trace.h"
+
+#define RTRS_CONNECT_TIMEOUT_MS 30000
+/*
+ * Wait a bit before trying to reconnect after a failure
+ * in order to give server time to finish clean up which
+ * leads to "false positives" failed reconnect attempts
+ */
+#define RTRS_RECONNECT_BACKOFF 1000
+/*
+ * Wait for additional random time between 0 and 8 seconds
+ * before starting to reconnect to avoid clients reconnecting
+ * all at once in case of a major network outage
+ */
+#define RTRS_RECONNECT_SEED 8
+
+#define FIRST_CONN 0x01
+/* limit to 128 * 4k = 512k max IO */
+#define RTRS_MAX_SEGMENTS 128
+
+MODULE_DESCRIPTION("RDMA Transport Client");
+MODULE_LICENSE("GPL");
+
+static const struct rtrs_rdma_dev_pd_ops dev_pd_ops;
+static struct rtrs_rdma_dev_pd dev_pd = {
+ .ops = &dev_pd_ops
+};
+
+static struct workqueue_struct *rtrs_wq;
+static struct class *rtrs_clt_dev_class;
+
+static inline bool rtrs_clt_is_connected(const struct rtrs_clt_sess *clt)
+{
+ struct rtrs_clt_path *clt_path;
+ bool connected = false;
+
+ rcu_read_lock();
+ list_for_each_entry_rcu(clt_path, &clt->paths_list, s.entry)
+ if (READ_ONCE(clt_path->state) == RTRS_CLT_CONNECTED) {
+ connected = true;
+ break;
+ }
+ rcu_read_unlock();
+
+ return connected;
+}
+
+static struct rtrs_permit *
+__rtrs_get_permit(struct rtrs_clt_sess *clt, enum rtrs_clt_con_type con_type)
+{
+ size_t max_depth = clt->queue_depth;
+ struct rtrs_permit *permit;
+ int bit;
+
+ /*
+ * Adapted from null_blk get_tag(). Callers from different cpus may
+ * grab the same bit, since find_first_zero_bit is not atomic.
+ * But then the test_and_set_bit_lock will fail for all the
+ * callers but one, so that they will loop again.
+ * This way an explicit spinlock is not required.
+ */
+ do {
+ bit = find_first_zero_bit(clt->permits_map, max_depth);
+ if (bit >= max_depth)
+ return NULL;
+ } while (test_and_set_bit_lock(bit, clt->permits_map));
+
+ permit = get_permit(clt, bit);
+ WARN_ON(permit->mem_id != bit);
+ permit->cpu_id = raw_smp_processor_id();
+ permit->con_type = con_type;
+
+ return permit;
+}
+
+static inline void __rtrs_put_permit(struct rtrs_clt_sess *clt,
+ struct rtrs_permit *permit)
+{
+ clear_bit_unlock(permit->mem_id, clt->permits_map);
+}
+
+/**
+ * rtrs_clt_get_permit() - allocates permit for future RDMA operation
+ * @clt: Current session
+ * @con_type: Type of connection to use with the permit
+ * @can_wait: Wait type
+ *
+ * Description:
+ * Allocates permit for the following RDMA operation. Permit is used
+ * to preallocate all resources and to propagate memory pressure
+ * up earlier.
+ *
+ * Context:
+ * Can sleep if @wait == RTRS_PERMIT_WAIT
+ */
+struct rtrs_permit *rtrs_clt_get_permit(struct rtrs_clt_sess *clt,
+ enum rtrs_clt_con_type con_type,
+ enum wait_type can_wait)
+{
+ struct rtrs_permit *permit;
+ DEFINE_WAIT(wait);
+
+ permit = __rtrs_get_permit(clt, con_type);
+ if (permit || !can_wait)
+ return permit;
+
+ do {
+ prepare_to_wait(&clt->permits_wait, &wait,
+ TASK_UNINTERRUPTIBLE);
+ permit = __rtrs_get_permit(clt, con_type);
+ if (permit)
+ break;
+
+ io_schedule();
+ } while (1);
+
+ finish_wait(&clt->permits_wait, &wait);
+
+ return permit;
+}
+EXPORT_SYMBOL(rtrs_clt_get_permit);
+
+/**
+ * rtrs_clt_put_permit() - puts allocated permit
+ * @clt: Current session
+ * @permit: Permit to be freed
+ *
+ * Context:
+ * Does not matter
+ */
+void rtrs_clt_put_permit(struct rtrs_clt_sess *clt,
+ struct rtrs_permit *permit)
+{
+ if (WARN_ON(!test_bit(permit->mem_id, clt->permits_map)))
+ return;
+
+ __rtrs_put_permit(clt, permit);
+
+ /*
+ * rtrs_clt_get_permit() adds itself to the &clt->permits_wait list
+ * before calling schedule(). So if rtrs_clt_get_permit() is sleeping
+ * it must have added itself to &clt->permits_wait before
+ * __rtrs_put_permit() finished.
+ * Hence it is safe to guard wake_up() with a waitqueue_active() test.
+ */
+ if (waitqueue_active(&clt->permits_wait))
+ wake_up(&clt->permits_wait);
+}
+EXPORT_SYMBOL(rtrs_clt_put_permit);
+
+/**
+ * rtrs_permit_to_clt_con() - returns RDMA connection pointer by the permit
+ * @clt_path: client path pointer
+ * @permit: permit for the allocation of the RDMA buffer
+ * Note:
+ * IO connection starts from 1.
+ * 0 connection is for user messages.
+ */
+static
+struct rtrs_clt_con *rtrs_permit_to_clt_con(struct rtrs_clt_path *clt_path,
+ struct rtrs_permit *permit)
+{
+ int id = 0;
+
+ if (permit->con_type == RTRS_IO_CON)
+ id = (permit->cpu_id % (clt_path->s.irq_con_num - 1)) + 1;
+
+ return to_clt_con(clt_path->s.con[id]);
+}
+
+/**
+ * rtrs_clt_change_state() - change the session state through session state
+ * machine.
+ *
+ * @clt_path: client path to change the state of.
+ * @new_state: state to change to.
+ *
+ * returns true if sess's state is changed to new state, otherwise return false.
+ *
+ * Locks:
+ * state_wq lock must be hold.
+ */
+static bool rtrs_clt_change_state(struct rtrs_clt_path *clt_path,
+ enum rtrs_clt_state new_state)
+{
+ enum rtrs_clt_state old_state;
+ bool changed = false;
+
+ lockdep_assert_held(&clt_path->state_wq.lock);
+
+ old_state = clt_path->state;
+ switch (new_state) {
+ case RTRS_CLT_CONNECTING:
+ switch (old_state) {
+ case RTRS_CLT_RECONNECTING:
+ changed = true;
+ fallthrough;
+ default:
+ break;
+ }
+ break;
+ case RTRS_CLT_RECONNECTING:
+ switch (old_state) {
+ case RTRS_CLT_CONNECTED:
+ case RTRS_CLT_CONNECTING_ERR:
+ case RTRS_CLT_CLOSED:
+ changed = true;
+ fallthrough;
+ default:
+ break;
+ }
+ break;
+ case RTRS_CLT_CONNECTED:
+ switch (old_state) {
+ case RTRS_CLT_CONNECTING:
+ changed = true;
+ fallthrough;
+ default:
+ break;
+ }
+ break;
+ case RTRS_CLT_CONNECTING_ERR:
+ switch (old_state) {
+ case RTRS_CLT_CONNECTING:
+ changed = true;
+ fallthrough;
+ default:
+ break;
+ }
+ break;
+ case RTRS_CLT_CLOSING:
+ switch (old_state) {
+ case RTRS_CLT_CONNECTING:
+ case RTRS_CLT_CONNECTING_ERR:
+ case RTRS_CLT_RECONNECTING:
+ case RTRS_CLT_CONNECTED:
+ changed = true;
+ fallthrough;
+ default:
+ break;
+ }
+ break;
+ case RTRS_CLT_CLOSED:
+ switch (old_state) {
+ case RTRS_CLT_CLOSING:
+ changed = true;
+ fallthrough;
+ default:
+ break;
+ }
+ break;
+ case RTRS_CLT_DEAD:
+ switch (old_state) {
+ case RTRS_CLT_CLOSED:
+ changed = true;
+ fallthrough;
+ default:
+ break;
+ }
+ break;
+ default:
+ break;
+ }
+ if (changed) {
+ clt_path->state = new_state;
+ wake_up_locked(&clt_path->state_wq);
+ }
+
+ return changed;
+}
+
+static bool rtrs_clt_change_state_from_to(struct rtrs_clt_path *clt_path,
+ enum rtrs_clt_state old_state,
+ enum rtrs_clt_state new_state)
+{
+ bool changed = false;
+
+ spin_lock_irq(&clt_path->state_wq.lock);
+ if (clt_path->state == old_state)
+ changed = rtrs_clt_change_state(clt_path, new_state);
+ spin_unlock_irq(&clt_path->state_wq.lock);
+
+ return changed;
+}
+
+static void rtrs_clt_stop_and_destroy_conns(struct rtrs_clt_path *clt_path);
+static void rtrs_rdma_error_recovery(struct rtrs_clt_con *con)
+{
+ struct rtrs_clt_path *clt_path = to_clt_path(con->c.path);
+
+ trace_rtrs_rdma_error_recovery(clt_path);
+
+ if (rtrs_clt_change_state_from_to(clt_path,
+ RTRS_CLT_CONNECTED,
+ RTRS_CLT_RECONNECTING)) {
+ queue_work(rtrs_wq, &clt_path->err_recovery_work);
+ } else {
+ /*
+ * Error can happen just on establishing new connection,
+ * so notify waiter with error state, waiter is responsible
+ * for cleaning the rest and reconnect if needed.
+ */
+ rtrs_clt_change_state_from_to(clt_path,
+ RTRS_CLT_CONNECTING,
+ RTRS_CLT_CONNECTING_ERR);
+ }
+}
+
+static void rtrs_clt_fast_reg_done(struct ib_cq *cq, struct ib_wc *wc)
+{
+ struct rtrs_clt_con *con = to_clt_con(wc->qp->qp_context);
+
+ if (wc->status != IB_WC_SUCCESS) {
+ rtrs_err(con->c.path, "Failed IB_WR_REG_MR: %s\n",
+ ib_wc_status_msg(wc->status));
+ rtrs_rdma_error_recovery(con);
+ }
+}
+
+static struct ib_cqe fast_reg_cqe = {
+ .done = rtrs_clt_fast_reg_done
+};
+
+static void complete_rdma_req(struct rtrs_clt_io_req *req, int errno,
+ bool notify, bool can_wait);
+
+static void rtrs_clt_inv_rkey_done(struct ib_cq *cq, struct ib_wc *wc)
+{
+ struct rtrs_clt_io_req *req =
+ container_of(wc->wr_cqe, typeof(*req), inv_cqe);
+ struct rtrs_clt_con *con = to_clt_con(wc->qp->qp_context);
+
+ if (wc->status != IB_WC_SUCCESS) {
+ rtrs_err(con->c.path, "Failed IB_WR_LOCAL_INV: %s\n",
+ ib_wc_status_msg(wc->status));
+ rtrs_rdma_error_recovery(con);
+ }
+ req->need_inv = false;
+ if (req->need_inv_comp)
+ complete(&req->inv_comp);
+ else
+ /* Complete request from INV callback */
+ complete_rdma_req(req, req->inv_errno, true, false);
+}
+
+static int rtrs_inv_rkey(struct rtrs_clt_io_req *req)
+{
+ struct rtrs_clt_con *con = req->con;
+ struct ib_send_wr wr = {
+ .opcode = IB_WR_LOCAL_INV,
+ .wr_cqe = &req->inv_cqe,
+ .send_flags = IB_SEND_SIGNALED,
+ .ex.invalidate_rkey = req->mr->rkey,
+ };
+ req->inv_cqe.done = rtrs_clt_inv_rkey_done;
+
+ return ib_post_send(con->c.qp, &wr, NULL);
+}
+
+static void complete_rdma_req(struct rtrs_clt_io_req *req, int errno,
+ bool notify, bool can_wait)
+{
+ struct rtrs_clt_con *con = req->con;
+ struct rtrs_clt_path *clt_path;
+ int err;
+
+ if (!req->in_use)
+ return;
+ if (WARN_ON(!req->con))
+ return;
+ clt_path = to_clt_path(con->c.path);
+
+ if (req->sg_cnt) {
+ if (req->dir == DMA_FROM_DEVICE && req->need_inv) {
+ /*
+ * We are here to invalidate read requests
+ * ourselves. In normal scenario server should
+ * send INV for all read requests, but
+ * we are here, thus two things could happen:
+ *
+ * 1. this is failover, when errno != 0
+ * and can_wait == 1,
+ *
+ * 2. something totally bad happened and
+ * server forgot to send INV, so we
+ * should do that ourselves.
+ */
+
+ if (can_wait) {
+ req->need_inv_comp = true;
+ } else {
+ /* This should be IO path, so always notify */
+ WARN_ON(!notify);
+ /* Save errno for INV callback */
+ req->inv_errno = errno;
+ }
+
+ refcount_inc(&req->ref);
+ err = rtrs_inv_rkey(req);
+ if (err) {
+ rtrs_err(con->c.path, "Send INV WR key=%#x: %d\n",
+ req->mr->rkey, err);
+ } else if (can_wait) {
+ wait_for_completion(&req->inv_comp);
+ } else {
+ /*
+ * Something went wrong, so request will be
+ * completed from INV callback.
+ */
+ WARN_ON_ONCE(1);
+
+ return;
+ }
+ if (!refcount_dec_and_test(&req->ref))
+ return;
+ }
+ ib_dma_unmap_sg(clt_path->s.dev->ib_dev, req->sglist,
+ req->sg_cnt, req->dir);
+ }
+ if (!refcount_dec_and_test(&req->ref))
+ return;
+ if (req->mp_policy == MP_POLICY_MIN_INFLIGHT)
+ atomic_dec(&clt_path->stats->inflight);
+
+ req->in_use = false;
+ req->con = NULL;
+
+ if (errno) {
+ rtrs_err_rl(con->c.path, "IO request failed: error=%d path=%s [%s:%u] notify=%d\n",
+ errno, kobject_name(&clt_path->kobj), clt_path->hca_name,
+ clt_path->hca_port, notify);
+ }
+
+ if (notify)
+ req->conf(req->priv, errno);
+}
+
+static int rtrs_post_send_rdma(struct rtrs_clt_con *con,
+ struct rtrs_clt_io_req *req,
+ struct rtrs_rbuf *rbuf, u32 off,
+ u32 imm, struct ib_send_wr *wr)
+{
+ struct rtrs_clt_path *clt_path = to_clt_path(con->c.path);
+ enum ib_send_flags flags;
+ struct ib_sge sge;
+
+ if (!req->sg_size) {
+ rtrs_wrn(con->c.path,
+ "Doing RDMA Write failed, no data supplied\n");
+ return -EINVAL;
+ }
+
+ /* user data and user message in the first list element */
+ sge.addr = req->iu->dma_addr;
+ sge.length = req->sg_size;
+ sge.lkey = clt_path->s.dev->ib_pd->local_dma_lkey;
+
+ /*
+ * From time to time we have to post signalled sends,
+ * or send queue will fill up and only QP reset can help.
+ */
+ flags = atomic_inc_return(&con->c.wr_cnt) % clt_path->s.signal_interval ?
+ 0 : IB_SEND_SIGNALED;
+
+ ib_dma_sync_single_for_device(clt_path->s.dev->ib_dev,
+ req->iu->dma_addr,
+ req->sg_size, DMA_TO_DEVICE);
+
+ return rtrs_iu_post_rdma_write_imm(&con->c, req->iu, &sge, 1,
+ rbuf->rkey, rbuf->addr + off,
+ imm, flags, wr, NULL);
+}
+
+static void process_io_rsp(struct rtrs_clt_path *clt_path, u32 msg_id,
+ s16 errno, bool w_inval)
+{
+ struct rtrs_clt_io_req *req;
+
+ if (WARN_ON(msg_id >= clt_path->queue_depth))
+ return;
+
+ req = &clt_path->reqs[msg_id];
+ /* Drop need_inv if server responded with send with invalidation */
+ req->need_inv &= !w_inval;
+ complete_rdma_req(req, errno, true, false);
+}
+
+static void rtrs_clt_recv_done(struct rtrs_clt_con *con, struct ib_wc *wc)
+{
+ struct rtrs_iu *iu;
+ int err;
+ struct rtrs_clt_path *clt_path = to_clt_path(con->c.path);
+
+ WARN_ON((clt_path->flags & RTRS_MSG_NEW_RKEY_F) == 0);
+ iu = container_of(wc->wr_cqe, struct rtrs_iu,
+ cqe);
+ err = rtrs_iu_post_recv(&con->c, iu);
+ if (err) {
+ rtrs_err(con->c.path, "post iu failed %d\n", err);
+ rtrs_rdma_error_recovery(con);
+ }
+}
+
+static void rtrs_clt_rkey_rsp_done(struct rtrs_clt_con *con, struct ib_wc *wc)
+{
+ struct rtrs_clt_path *clt_path = to_clt_path(con->c.path);
+ struct rtrs_msg_rkey_rsp *msg;
+ u32 imm_type, imm_payload;
+ bool w_inval = false;
+ struct rtrs_iu *iu;
+ u32 buf_id;
+ int err;
+
+ WARN_ON((clt_path->flags & RTRS_MSG_NEW_RKEY_F) == 0);
+
+ iu = container_of(wc->wr_cqe, struct rtrs_iu, cqe);
+
+ if (wc->byte_len < sizeof(*msg)) {
+ rtrs_err(con->c.path, "rkey response is malformed: size %d\n",
+ wc->byte_len);
+ goto out;
+ }
+ ib_dma_sync_single_for_cpu(clt_path->s.dev->ib_dev, iu->dma_addr,
+ iu->size, DMA_FROM_DEVICE);
+ msg = iu->buf;
+ if (le16_to_cpu(msg->type) != RTRS_MSG_RKEY_RSP) {
+ rtrs_err(clt_path->clt,
+ "rkey response is malformed: type %d\n",
+ le16_to_cpu(msg->type));
+ goto out;
+ }
+ buf_id = le16_to_cpu(msg->buf_id);
+ if (WARN_ON(buf_id >= clt_path->queue_depth))
+ goto out;
+
+ rtrs_from_imm(be32_to_cpu(wc->ex.imm_data), &imm_type, &imm_payload);
+ if (imm_type == RTRS_IO_RSP_IMM ||
+ imm_type == RTRS_IO_RSP_W_INV_IMM) {
+ u32 msg_id;
+
+ w_inval = (imm_type == RTRS_IO_RSP_W_INV_IMM);
+ rtrs_from_io_rsp_imm(imm_payload, &msg_id, &err);
+
+ if (WARN_ON(buf_id != msg_id))
+ goto out;
+ clt_path->rbufs[buf_id].rkey = le32_to_cpu(msg->rkey);
+ process_io_rsp(clt_path, msg_id, err, w_inval);
+ }
+ ib_dma_sync_single_for_device(clt_path->s.dev->ib_dev, iu->dma_addr,
+ iu->size, DMA_FROM_DEVICE);
+ return rtrs_clt_recv_done(con, wc);
+out:
+ rtrs_rdma_error_recovery(con);
+}
+
+static void rtrs_clt_rdma_done(struct ib_cq *cq, struct ib_wc *wc);
+
+static struct ib_cqe io_comp_cqe = {
+ .done = rtrs_clt_rdma_done
+};
+
+/*
+ * Post x2 empty WRs: first is for this RDMA with IMM,
+ * second is for RECV with INV, which happened earlier.
+ */
+static int rtrs_post_recv_empty_x2(struct rtrs_con *con, struct ib_cqe *cqe)
+{
+ struct ib_recv_wr wr_arr[2], *wr;
+ int i;
+
+ memset(wr_arr, 0, sizeof(wr_arr));
+ for (i = 0; i < ARRAY_SIZE(wr_arr); i++) {
+ wr = &wr_arr[i];
+ wr->wr_cqe = cqe;
+ if (i)
+ /* Chain backwards */
+ wr->next = &wr_arr[i - 1];
+ }
+
+ return ib_post_recv(con->qp, wr, NULL);
+}
+
+static void rtrs_clt_rdma_done(struct ib_cq *cq, struct ib_wc *wc)
+{
+ struct rtrs_clt_con *con = to_clt_con(wc->qp->qp_context);
+ struct rtrs_clt_path *clt_path = to_clt_path(con->c.path);
+ u32 imm_type, imm_payload;
+ bool w_inval = false;
+ int err;
+
+ if (wc->status != IB_WC_SUCCESS) {
+ if (wc->status != IB_WC_WR_FLUSH_ERR) {
+ rtrs_err(clt_path->clt, "RDMA failed: %s\n",
+ ib_wc_status_msg(wc->status));
+ rtrs_rdma_error_recovery(con);
+ }
+ return;
+ }
+ rtrs_clt_update_wc_stats(con);
+
+ switch (wc->opcode) {
+ case IB_WC_RECV_RDMA_WITH_IMM:
+ /*
+ * post_recv() RDMA write completions of IO reqs (read/write)
+ * and hb
+ */
+ if (WARN_ON(wc->wr_cqe->done != rtrs_clt_rdma_done))
+ return;
+ rtrs_from_imm(be32_to_cpu(wc->ex.imm_data),
+ &imm_type, &imm_payload);
+ if (imm_type == RTRS_IO_RSP_IMM ||
+ imm_type == RTRS_IO_RSP_W_INV_IMM) {
+ u32 msg_id;
+
+ w_inval = (imm_type == RTRS_IO_RSP_W_INV_IMM);
+ rtrs_from_io_rsp_imm(imm_payload, &msg_id, &err);
+
+ process_io_rsp(clt_path, msg_id, err, w_inval);
+ } else if (imm_type == RTRS_HB_MSG_IMM) {
+ WARN_ON(con->c.cid);
+ rtrs_send_hb_ack(&clt_path->s);
+ if (clt_path->flags & RTRS_MSG_NEW_RKEY_F)
+ return rtrs_clt_recv_done(con, wc);
+ } else if (imm_type == RTRS_HB_ACK_IMM) {
+ WARN_ON(con->c.cid);
+ clt_path->s.hb_missed_cnt = 0;
+ clt_path->s.hb_cur_latency =
+ ktime_sub(ktime_get(), clt_path->s.hb_last_sent);
+ if (clt_path->flags & RTRS_MSG_NEW_RKEY_F)
+ return rtrs_clt_recv_done(con, wc);
+ } else {
+ rtrs_wrn(con->c.path, "Unknown IMM type %u\n",
+ imm_type);
+ }
+ if (w_inval)
+ /*
+ * Post x2 empty WRs: first is for this RDMA with IMM,
+ * second is for RECV with INV, which happened earlier.
+ */
+ err = rtrs_post_recv_empty_x2(&con->c, &io_comp_cqe);
+ else
+ err = rtrs_post_recv_empty(&con->c, &io_comp_cqe);
+ if (err) {
+ rtrs_err(con->c.path, "rtrs_post_recv_empty(): %d\n",
+ err);
+ rtrs_rdma_error_recovery(con);
+ }
+ break;
+ case IB_WC_RECV:
+ /*
+ * Key invalidations from server side
+ */
+ WARN_ON(!(wc->wc_flags & IB_WC_WITH_INVALIDATE ||
+ wc->wc_flags & IB_WC_WITH_IMM));
+ WARN_ON(wc->wr_cqe->done != rtrs_clt_rdma_done);
+ if (clt_path->flags & RTRS_MSG_NEW_RKEY_F) {
+ if (wc->wc_flags & IB_WC_WITH_INVALIDATE)
+ return rtrs_clt_recv_done(con, wc);
+
+ return rtrs_clt_rkey_rsp_done(con, wc);
+ }
+ break;
+ case IB_WC_RDMA_WRITE:
+ /*
+ * post_send() RDMA write completions of IO reqs (read/write)
+ * and hb.
+ */
+ break;
+
+ default:
+ rtrs_wrn(clt_path->clt, "Unexpected WC type: %d\n", wc->opcode);
+ return;
+ }
+}
+
+static int post_recv_io(struct rtrs_clt_con *con, size_t q_size)
+{
+ int err, i;
+ struct rtrs_clt_path *clt_path = to_clt_path(con->c.path);
+
+ for (i = 0; i < q_size; i++) {
+ if (clt_path->flags & RTRS_MSG_NEW_RKEY_F) {
+ struct rtrs_iu *iu = &con->rsp_ius[i];
+
+ err = rtrs_iu_post_recv(&con->c, iu);
+ } else {
+ err = rtrs_post_recv_empty(&con->c, &io_comp_cqe);
+ }
+ if (err)
+ return err;
+ }
+
+ return 0;
+}
+
+static int post_recv_path(struct rtrs_clt_path *clt_path)
+{
+ size_t q_size = 0;
+ int err, cid;
+
+ for (cid = 0; cid < clt_path->s.con_num; cid++) {
+ if (cid == 0)
+ q_size = SERVICE_CON_QUEUE_DEPTH;
+ else
+ q_size = clt_path->queue_depth;
+
+ /*
+ * x2 for RDMA read responses + FR key invalidations,
+ * RDMA writes do not require any FR registrations.
+ */
+ q_size *= 2;
+
+ err = post_recv_io(to_clt_con(clt_path->s.con[cid]), q_size);
+ if (err) {
+ rtrs_err(clt_path->clt, "post_recv_io(), err: %d\n",
+ err);
+ return err;
+ }
+ }
+
+ return 0;
+}
+
+struct path_it {
+ int i;
+ struct list_head skip_list;
+ struct rtrs_clt_sess *clt;
+ struct rtrs_clt_path *(*next_path)(struct path_it *it);
+};
+
+/*
+ * rtrs_clt_get_next_path_or_null - get clt path from the list or return NULL
+ * @head: the head for the list.
+ * @clt_path: The element to take the next clt_path from.
+ *
+ * Next clt path returned in round-robin fashion, i.e. head will be skipped,
+ * but if list is observed as empty, NULL will be returned.
+ *
+ * This function may safely run concurrently with the _rcu list-mutation
+ * primitives such as list_add_rcu() as long as it's guarded by rcu_read_lock().
+ */
+static inline struct rtrs_clt_path *
+rtrs_clt_get_next_path_or_null(struct list_head *head, struct rtrs_clt_path *clt_path)
+{
+ return list_next_or_null_rcu(head, &clt_path->s.entry, typeof(*clt_path), s.entry) ?:
+ list_next_or_null_rcu(head,
+ READ_ONCE((&clt_path->s.entry)->next),
+ typeof(*clt_path), s.entry);
+}
+
+/**
+ * get_next_path_rr() - Returns path in round-robin fashion.
+ * @it: the path pointer
+ *
+ * Related to @MP_POLICY_RR
+ *
+ * Locks:
+ * rcu_read_lock() must be hold.
+ */
+static struct rtrs_clt_path *get_next_path_rr(struct path_it *it)
+{
+ struct rtrs_clt_path __rcu **ppcpu_path;
+ struct rtrs_clt_path *path;
+ struct rtrs_clt_sess *clt;
+
+ clt = it->clt;
+
+ /*
+ * Here we use two RCU objects: @paths_list and @pcpu_path
+ * pointer. See rtrs_clt_remove_path_from_arr() for details
+ * how that is handled.
+ */
+
+ ppcpu_path = this_cpu_ptr(clt->pcpu_path);
+ path = rcu_dereference(*ppcpu_path);
+ if (!path)
+ path = list_first_or_null_rcu(&clt->paths_list,
+ typeof(*path), s.entry);
+ else
+ path = rtrs_clt_get_next_path_or_null(&clt->paths_list, path);
+
+ rcu_assign_pointer(*ppcpu_path, path);
+
+ return path;
+}
+
+/**
+ * get_next_path_min_inflight() - Returns path with minimal inflight count.
+ * @it: the path pointer
+ *
+ * Related to @MP_POLICY_MIN_INFLIGHT
+ *
+ * Locks:
+ * rcu_read_lock() must be hold.
+ */
+static struct rtrs_clt_path *get_next_path_min_inflight(struct path_it *it)
+{
+ struct rtrs_clt_path *min_path = NULL;
+ struct rtrs_clt_sess *clt = it->clt;
+ struct rtrs_clt_path *clt_path;
+ int min_inflight = INT_MAX;
+ int inflight;
+
+ list_for_each_entry_rcu(clt_path, &clt->paths_list, s.entry) {
+ if (READ_ONCE(clt_path->state) != RTRS_CLT_CONNECTED)
+ continue;
+
+ if (!list_empty(raw_cpu_ptr(clt_path->mp_skip_entry)))
+ continue;
+
+ inflight = atomic_read(&clt_path->stats->inflight);
+
+ if (inflight < min_inflight) {
+ min_inflight = inflight;
+ min_path = clt_path;
+ }
+ }
+
+ /*
+ * add the path to the skip list, so that next time we can get
+ * a different one
+ */
+ if (min_path)
+ list_add(raw_cpu_ptr(min_path->mp_skip_entry), &it->skip_list);
+
+ return min_path;
+}
+
+/**
+ * get_next_path_min_latency() - Returns path with minimal latency.
+ * @it: the path pointer
+ *
+ * Return: a path with the lowest latency or NULL if all paths are tried
+ *
+ * Locks:
+ * rcu_read_lock() must be hold.
+ *
+ * Related to @MP_POLICY_MIN_LATENCY
+ *
+ * This DOES skip an already-tried path.
+ * There is a skip-list to skip a path if the path has tried but failed.
+ * It will try the minimum latency path and then the second minimum latency
+ * path and so on. Finally it will return NULL if all paths are tried.
+ * Therefore the caller MUST check the returned
+ * path is NULL and trigger the IO error.
+ */
+static struct rtrs_clt_path *get_next_path_min_latency(struct path_it *it)
+{
+ struct rtrs_clt_path *min_path = NULL;
+ struct rtrs_clt_sess *clt = it->clt;
+ struct rtrs_clt_path *clt_path;
+ ktime_t min_latency = KTIME_MAX;
+ ktime_t latency;
+
+ list_for_each_entry_rcu(clt_path, &clt->paths_list, s.entry) {
+ if (READ_ONCE(clt_path->state) != RTRS_CLT_CONNECTED)
+ continue;
+
+ if (!list_empty(raw_cpu_ptr(clt_path->mp_skip_entry)))
+ continue;
+
+ latency = clt_path->s.hb_cur_latency;
+
+ if (latency < min_latency) {
+ min_latency = latency;
+ min_path = clt_path;
+ }
+ }
+
+ /*
+ * add the path to the skip list, so that next time we can get
+ * a different one
+ */
+ if (min_path)
+ list_add(raw_cpu_ptr(min_path->mp_skip_entry), &it->skip_list);
+
+ return min_path;
+}
+
+static inline void path_it_init(struct path_it *it, struct rtrs_clt_sess *clt)
+{
+ INIT_LIST_HEAD(&it->skip_list);
+ it->clt = clt;
+ it->i = 0;
+
+ if (clt->mp_policy == MP_POLICY_RR)
+ it->next_path = get_next_path_rr;
+ else if (clt->mp_policy == MP_POLICY_MIN_INFLIGHT)
+ it->next_path = get_next_path_min_inflight;
+ else
+ it->next_path = get_next_path_min_latency;
+}
+
+static inline void path_it_deinit(struct path_it *it)
+{
+ struct list_head *skip, *tmp;
+ /*
+ * The skip_list is used only for the MIN_INFLIGHT and MIN_LATENCY policies.
+ * We need to remove paths from it, so that next IO can insert
+ * paths (->mp_skip_entry) into a skip_list again.
+ */
+ list_for_each_safe(skip, tmp, &it->skip_list)
+ list_del_init(skip);
+}
+
+/**
+ * rtrs_clt_init_req() - Initialize an rtrs_clt_io_req holding information
+ * about an inflight IO.
+ * The user buffer holding user control message (not data) is copied into
+ * the corresponding buffer of rtrs_iu (req->iu->buf), which later on will
+ * also hold the control message of rtrs.
+ * @req: an io request holding information about IO.
+ * @clt_path: client path
+ * @conf: conformation callback function to notify upper layer.
+ * @permit: permit for allocation of RDMA remote buffer
+ * @priv: private pointer
+ * @vec: kernel vector containing control message
+ * @usr_len: length of the user message
+ * @sg: scater list for IO data
+ * @sg_cnt: number of scater list entries
+ * @data_len: length of the IO data
+ * @dir: direction of the IO.
+ */
+static void rtrs_clt_init_req(struct rtrs_clt_io_req *req,
+ struct rtrs_clt_path *clt_path,
+ void (*conf)(void *priv, int errno),
+ struct rtrs_permit *permit, void *priv,
+ const struct kvec *vec, size_t usr_len,
+ struct scatterlist *sg, size_t sg_cnt,
+ size_t data_len, int dir)
+{
+ struct iov_iter iter;
+ size_t len;
+
+ req->permit = permit;
+ req->in_use = true;
+ req->usr_len = usr_len;
+ req->data_len = data_len;
+ req->sglist = sg;
+ req->sg_cnt = sg_cnt;
+ req->priv = priv;
+ req->dir = dir;
+ req->con = rtrs_permit_to_clt_con(clt_path, permit);
+ req->conf = conf;
+ req->need_inv = false;
+ req->need_inv_comp = false;
+ req->inv_errno = 0;
+ refcount_set(&req->ref, 1);
+ req->mp_policy = clt_path->clt->mp_policy;
+
+ iov_iter_kvec(&iter, ITER_SOURCE, vec, 1, usr_len);
+ len = _copy_from_iter(req->iu->buf, usr_len, &iter);
+ WARN_ON(len != usr_len);
+
+ reinit_completion(&req->inv_comp);
+}
+
+static struct rtrs_clt_io_req *
+rtrs_clt_get_req(struct rtrs_clt_path *clt_path,
+ void (*conf)(void *priv, int errno),
+ struct rtrs_permit *permit, void *priv,
+ const struct kvec *vec, size_t usr_len,
+ struct scatterlist *sg, size_t sg_cnt,
+ size_t data_len, int dir)
+{
+ struct rtrs_clt_io_req *req;
+
+ req = &clt_path->reqs[permit->mem_id];
+ rtrs_clt_init_req(req, clt_path, conf, permit, priv, vec, usr_len,
+ sg, sg_cnt, data_len, dir);
+ return req;
+}
+
+static struct rtrs_clt_io_req *
+rtrs_clt_get_copy_req(struct rtrs_clt_path *alive_path,
+ struct rtrs_clt_io_req *fail_req)
+{
+ struct rtrs_clt_io_req *req;
+ struct kvec vec = {
+ .iov_base = fail_req->iu->buf,
+ .iov_len = fail_req->usr_len
+ };
+
+ req = &alive_path->reqs[fail_req->permit->mem_id];
+ rtrs_clt_init_req(req, alive_path, fail_req->conf, fail_req->permit,
+ fail_req->priv, &vec, fail_req->usr_len,
+ fail_req->sglist, fail_req->sg_cnt,
+ fail_req->data_len, fail_req->dir);
+ return req;
+}
+
+static int rtrs_post_rdma_write_sg(struct rtrs_clt_con *con,
+ struct rtrs_clt_io_req *req,
+ struct rtrs_rbuf *rbuf, bool fr_en,
+ u32 count, u32 size, u32 imm,
+ struct ib_send_wr *wr,
+ struct ib_send_wr *tail)
+{
+ struct rtrs_clt_path *clt_path = to_clt_path(con->c.path);
+ struct ib_sge *sge = req->sge;
+ enum ib_send_flags flags;
+ struct scatterlist *sg;
+ size_t num_sge;
+ int i;
+ struct ib_send_wr *ptail = NULL;
+
+ if (fr_en) {
+ i = 0;
+ sge[i].addr = req->mr->iova;
+ sge[i].length = req->mr->length;
+ sge[i].lkey = req->mr->lkey;
+ i++;
+ num_sge = 2;
+ ptail = tail;
+ } else {
+ for_each_sg(req->sglist, sg, count, i) {
+ sge[i].addr = sg_dma_address(sg);
+ sge[i].length = sg_dma_len(sg);
+ sge[i].lkey = clt_path->s.dev->ib_pd->local_dma_lkey;
+ }
+ num_sge = 1 + count;
+ }
+ sge[i].addr = req->iu->dma_addr;
+ sge[i].length = size;
+ sge[i].lkey = clt_path->s.dev->ib_pd->local_dma_lkey;
+
+ /*
+ * From time to time we have to post signalled sends,
+ * or send queue will fill up and only QP reset can help.
+ */
+ flags = atomic_inc_return(&con->c.wr_cnt) % clt_path->s.signal_interval ?
+ 0 : IB_SEND_SIGNALED;
+
+ ib_dma_sync_single_for_device(clt_path->s.dev->ib_dev,
+ req->iu->dma_addr,
+ size, DMA_TO_DEVICE);
+
+ return rtrs_iu_post_rdma_write_imm(&con->c, req->iu, sge, num_sge,
+ rbuf->rkey, rbuf->addr, imm,
+ flags, wr, ptail);
+}
+
+static int rtrs_map_sg_fr(struct rtrs_clt_io_req *req, size_t count)
+{
+ int nr;
+
+ /* Align the MR to a 4K page size to match the block virt boundary */
+ nr = ib_map_mr_sg(req->mr, req->sglist, count, NULL, SZ_4K);
+ if (nr < 0)
+ return nr;
+ if (nr < req->sg_cnt)
+ return -EINVAL;
+ ib_update_fast_reg_key(req->mr, ib_inc_rkey(req->mr->rkey));
+
+ return nr;
+}
+
+static int rtrs_clt_write_req(struct rtrs_clt_io_req *req)
+{
+ struct rtrs_clt_con *con = req->con;
+ struct rtrs_path *s = con->c.path;
+ struct rtrs_clt_path *clt_path = to_clt_path(s);
+ struct rtrs_msg_rdma_write *msg;
+
+ struct rtrs_rbuf *rbuf;
+ int ret, count = 0;
+ u32 imm, buf_id;
+ struct ib_reg_wr rwr;
+ struct ib_send_wr inv_wr;
+ struct ib_send_wr *wr = NULL;
+ bool fr_en = false;
+
+ const size_t tsize = sizeof(*msg) + req->data_len + req->usr_len;
+
+ if (tsize > clt_path->chunk_size) {
+ rtrs_wrn(s, "Write request failed, size too big %zu > %d\n",
+ tsize, clt_path->chunk_size);
+ return -EMSGSIZE;
+ }
+ if (req->sg_cnt) {
+ count = ib_dma_map_sg(clt_path->s.dev->ib_dev, req->sglist,
+ req->sg_cnt, req->dir);
+ if (!count) {
+ rtrs_wrn(s, "Write request failed, map failed\n");
+ return -EINVAL;
+ }
+ }
+ /* put rtrs msg after sg and user message */
+ msg = req->iu->buf + req->usr_len;
+ msg->type = cpu_to_le16(RTRS_MSG_WRITE);
+ msg->usr_len = cpu_to_le16(req->usr_len);
+
+ /* rtrs message on server side will be after user data and message */
+ imm = req->permit->mem_off + req->data_len + req->usr_len;
+ imm = rtrs_to_io_req_imm(imm);
+ buf_id = req->permit->mem_id;
+ req->sg_size = tsize;
+ rbuf = &clt_path->rbufs[buf_id];
+
+ if (count) {
+ ret = rtrs_map_sg_fr(req, count);
+ if (ret < 0) {
+ rtrs_err_rl(s,
+ "Write request failed, failed to map fast reg. data, err: %d\n",
+ ret);
+ ib_dma_unmap_sg(clt_path->s.dev->ib_dev, req->sglist,
+ req->sg_cnt, req->dir);
+ return ret;
+ }
+ inv_wr = (struct ib_send_wr) {
+ .opcode = IB_WR_LOCAL_INV,
+ .wr_cqe = &req->inv_cqe,
+ .send_flags = IB_SEND_SIGNALED,
+ .ex.invalidate_rkey = req->mr->rkey,
+ };
+ req->inv_cqe.done = rtrs_clt_inv_rkey_done;
+ rwr = (struct ib_reg_wr) {
+ .wr.opcode = IB_WR_REG_MR,
+ .wr.wr_cqe = &fast_reg_cqe,
+ .mr = req->mr,
+ .key = req->mr->rkey,
+ .access = (IB_ACCESS_LOCAL_WRITE),
+ };
+ wr = &rwr.wr;
+ fr_en = true;
+ refcount_inc(&req->ref);
+ }
+ /*
+ * Update stats now, after request is successfully sent it is not
+ * safe anymore to touch it.
+ */
+ rtrs_clt_update_all_stats(req, WRITE);
+
+ ret = rtrs_post_rdma_write_sg(req->con, req, rbuf, fr_en, count,
+ req->usr_len + sizeof(*msg),
+ imm, wr, &inv_wr);
+ if (ret) {
+ rtrs_err_rl(s,
+ "Write request failed: error=%d path=%s [%s:%u]\n",
+ ret, kobject_name(&clt_path->kobj), clt_path->hca_name,
+ clt_path->hca_port);
+ if (req->mp_policy == MP_POLICY_MIN_INFLIGHT)
+ atomic_dec(&clt_path->stats->inflight);
+ if (req->sg_cnt)
+ ib_dma_unmap_sg(clt_path->s.dev->ib_dev, req->sglist,
+ req->sg_cnt, req->dir);
+ }
+
+ return ret;
+}
+
+static int rtrs_clt_read_req(struct rtrs_clt_io_req *req)
+{
+ struct rtrs_clt_con *con = req->con;
+ struct rtrs_path *s = con->c.path;
+ struct rtrs_clt_path *clt_path = to_clt_path(s);
+ struct rtrs_msg_rdma_read *msg;
+ struct rtrs_ib_dev *dev = clt_path->s.dev;
+
+ struct ib_reg_wr rwr;
+ struct ib_send_wr *wr = NULL;
+
+ int ret, count = 0;
+ u32 imm, buf_id;
+
+ const size_t tsize = sizeof(*msg) + req->data_len + req->usr_len;
+
+ if (tsize > clt_path->chunk_size) {
+ rtrs_wrn(s,
+ "Read request failed, message size is %zu, bigger than CHUNK_SIZE %d\n",
+ tsize, clt_path->chunk_size);
+ return -EMSGSIZE;
+ }
+
+ if (req->sg_cnt) {
+ count = ib_dma_map_sg(dev->ib_dev, req->sglist, req->sg_cnt,
+ req->dir);
+ if (!count) {
+ rtrs_wrn(s,
+ "Read request failed, dma map failed\n");
+ return -EINVAL;
+ }
+ }
+ /* put our message into req->buf after user message*/
+ msg = req->iu->buf + req->usr_len;
+ msg->type = cpu_to_le16(RTRS_MSG_READ);
+ msg->usr_len = cpu_to_le16(req->usr_len);
+
+ if (count) {
+ ret = rtrs_map_sg_fr(req, count);
+ if (ret < 0) {
+ rtrs_err_rl(s,
+ "Read request failed, failed to map fast reg. data, err: %d\n",
+ ret);
+ ib_dma_unmap_sg(dev->ib_dev, req->sglist, req->sg_cnt,
+ req->dir);
+ return ret;
+ }
+ rwr = (struct ib_reg_wr) {
+ .wr.opcode = IB_WR_REG_MR,
+ .wr.wr_cqe = &fast_reg_cqe,
+ .mr = req->mr,
+ .key = req->mr->rkey,
+ .access = (IB_ACCESS_LOCAL_WRITE |
+ IB_ACCESS_REMOTE_WRITE),
+ };
+ wr = &rwr.wr;
+
+ msg->sg_cnt = cpu_to_le16(1);
+ msg->flags = cpu_to_le16(RTRS_MSG_NEED_INVAL_F);
+
+ msg->desc[0].addr = cpu_to_le64(req->mr->iova);
+ msg->desc[0].key = cpu_to_le32(req->mr->rkey);
+ msg->desc[0].len = cpu_to_le32(req->mr->length);
+
+ /* Further invalidation is required */
+ req->need_inv = !!RTRS_MSG_NEED_INVAL_F;
+
+ } else {
+ msg->sg_cnt = 0;
+ msg->flags = 0;
+ }
+ /*
+ * rtrs message will be after the space reserved for disk data and
+ * user message
+ */
+ imm = req->permit->mem_off + req->data_len + req->usr_len;
+ imm = rtrs_to_io_req_imm(imm);
+ buf_id = req->permit->mem_id;
+
+ req->sg_size = sizeof(*msg);
+ req->sg_size += le16_to_cpu(msg->sg_cnt) * sizeof(struct rtrs_sg_desc);
+ req->sg_size += req->usr_len;
+
+ /*
+ * Update stats now, after request is successfully sent it is not
+ * safe anymore to touch it.
+ */
+ rtrs_clt_update_all_stats(req, READ);
+
+ ret = rtrs_post_send_rdma(req->con, req, &clt_path->rbufs[buf_id],
+ req->data_len, imm, wr);
+ if (ret) {
+ rtrs_err_rl(s,
+ "Read request failed: error=%d path=%s [%s:%u]\n",
+ ret, kobject_name(&clt_path->kobj), clt_path->hca_name,
+ clt_path->hca_port);
+ if (req->mp_policy == MP_POLICY_MIN_INFLIGHT)
+ atomic_dec(&clt_path->stats->inflight);
+ req->need_inv = false;
+ if (req->sg_cnt)
+ ib_dma_unmap_sg(dev->ib_dev, req->sglist,
+ req->sg_cnt, req->dir);
+ }
+
+ return ret;
+}
+
+/**
+ * rtrs_clt_failover_req() - Try to find an active path for a failed request
+ * @clt: clt context
+ * @fail_req: a failed io request.
+ */
+static int rtrs_clt_failover_req(struct rtrs_clt_sess *clt,
+ struct rtrs_clt_io_req *fail_req)
+{
+ struct rtrs_clt_path *alive_path;
+ struct rtrs_clt_io_req *req;
+ int err = -ECONNABORTED;
+ struct path_it it;
+
+ rcu_read_lock();
+ for (path_it_init(&it, clt);
+ (alive_path = it.next_path(&it)) && it.i < it.clt->paths_num;
+ it.i++) {
+ if (READ_ONCE(alive_path->state) != RTRS_CLT_CONNECTED)
+ continue;
+ req = rtrs_clt_get_copy_req(alive_path, fail_req);
+ if (req->dir == DMA_TO_DEVICE)
+ err = rtrs_clt_write_req(req);
+ else
+ err = rtrs_clt_read_req(req);
+ if (err) {
+ req->in_use = false;
+ continue;
+ }
+ /* Success path */
+ rtrs_clt_inc_failover_cnt(alive_path->stats);
+ break;
+ }
+ path_it_deinit(&it);
+ rcu_read_unlock();
+
+ return err;
+}
+
+static void fail_all_outstanding_reqs(struct rtrs_clt_path *clt_path)
+{
+ struct rtrs_clt_sess *clt = clt_path->clt;
+ struct rtrs_clt_io_req *req;
+ int i, err;
+
+ if (!clt_path->reqs)
+ return;
+ for (i = 0; i < clt_path->queue_depth; ++i) {
+ req = &clt_path->reqs[i];
+ if (!req->in_use)
+ continue;
+
+ /*
+ * Safely (without notification) complete failed request.
+ * After completion this request is still useble and can
+ * be failovered to another path.
+ */
+ complete_rdma_req(req, -ECONNABORTED, false, true);
+
+ err = rtrs_clt_failover_req(clt, req);
+ if (err)
+ /* Failover failed, notify anyway */
+ req->conf(req->priv, err);
+ }
+}
+
+static void free_path_reqs(struct rtrs_clt_path *clt_path)
+{
+ struct rtrs_clt_io_req *req;
+ int i;
+
+ if (!clt_path->reqs)
+ return;
+ for (i = 0; i < clt_path->queue_depth; ++i) {
+ req = &clt_path->reqs[i];
+ if (req->mr)
+ ib_dereg_mr(req->mr);
+ kfree(req->sge);
+ rtrs_iu_free(req->iu, clt_path->s.dev->ib_dev, 1);
+ }
+ kfree(clt_path->reqs);
+ clt_path->reqs = NULL;
+}
+
+static int alloc_path_reqs(struct rtrs_clt_path *clt_path)
+{
+ struct rtrs_clt_io_req *req;
+ int i, err = -ENOMEM;
+
+ clt_path->reqs = kcalloc(clt_path->queue_depth,
+ sizeof(*clt_path->reqs),
+ GFP_KERNEL);
+ if (!clt_path->reqs)
+ return -ENOMEM;
+
+ for (i = 0; i < clt_path->queue_depth; ++i) {
+ req = &clt_path->reqs[i];
+ req->iu = rtrs_iu_alloc(1, clt_path->max_hdr_size, GFP_KERNEL,
+ clt_path->s.dev->ib_dev,
+ DMA_TO_DEVICE,
+ rtrs_clt_rdma_done);
+ if (!req->iu)
+ goto out;
+
+ req->sge = kcalloc(2, sizeof(*req->sge), GFP_KERNEL);
+ if (!req->sge)
+ goto out;
+
+ req->mr = ib_alloc_mr(clt_path->s.dev->ib_pd,
+ IB_MR_TYPE_MEM_REG,
+ clt_path->max_pages_per_mr);
+ if (IS_ERR(req->mr)) {
+ err = PTR_ERR(req->mr);
+ req->mr = NULL;
+ pr_err("Failed to alloc clt_path->max_pages_per_mr %d\n",
+ clt_path->max_pages_per_mr);
+ goto out;
+ }
+
+ init_completion(&req->inv_comp);
+ }
+
+ return 0;
+
+out:
+ free_path_reqs(clt_path);
+
+ return err;
+}
+
+static int alloc_permits(struct rtrs_clt_sess *clt)
+{
+ unsigned int chunk_bits;
+ int err, i;
+
+ clt->permits_map = bitmap_zalloc(clt->queue_depth, GFP_KERNEL);
+ if (!clt->permits_map) {
+ err = -ENOMEM;
+ goto out_err;
+ }
+ clt->permits = kcalloc(clt->queue_depth, permit_size(clt), GFP_KERNEL);
+ if (!clt->permits) {
+ err = -ENOMEM;
+ goto err_map;
+ }
+ chunk_bits = ilog2(clt->queue_depth - 1) + 1;
+ for (i = 0; i < clt->queue_depth; i++) {
+ struct rtrs_permit *permit;
+
+ permit = get_permit(clt, i);
+ permit->mem_id = i;
+ permit->mem_off = i << (MAX_IMM_PAYL_BITS - chunk_bits);
+ }
+
+ return 0;
+
+err_map:
+ bitmap_free(clt->permits_map);
+ clt->permits_map = NULL;
+out_err:
+ return err;
+}
+
+static void free_permits(struct rtrs_clt_sess *clt)
+{
+ if (clt->permits_map)
+ wait_event(clt->permits_wait,
+ bitmap_empty(clt->permits_map, clt->queue_depth));
+
+ bitmap_free(clt->permits_map);
+ clt->permits_map = NULL;
+ kfree(clt->permits);
+ clt->permits = NULL;
+}
+
+static void query_fast_reg_mode(struct rtrs_clt_path *clt_path)
+{
+ struct ib_device *ib_dev;
+ u64 max_pages_per_mr;
+ int mr_page_shift;
+
+ ib_dev = clt_path->s.dev->ib_dev;
+
+ /*
+ * Use the smallest page size supported by the HCA, down to a
+ * minimum of 4096 bytes. We're unlikely to build large sglists
+ * out of smaller entries.
+ */
+ mr_page_shift = max(12, ffs(ib_dev->attrs.page_size_cap) - 1);
+ max_pages_per_mr = ib_dev->attrs.max_mr_size;
+ do_div(max_pages_per_mr, (1ull << mr_page_shift));
+ clt_path->max_pages_per_mr =
+ min3(clt_path->max_pages_per_mr, (u32)max_pages_per_mr,
+ ib_dev->attrs.max_fast_reg_page_list_len);
+ clt_path->clt->max_segments =
+ min(clt_path->max_pages_per_mr, clt_path->clt->max_segments);
+}
+
+static bool rtrs_clt_change_state_get_old(struct rtrs_clt_path *clt_path,
+ enum rtrs_clt_state new_state,
+ enum rtrs_clt_state *old_state)
+{
+ bool changed;
+
+ spin_lock_irq(&clt_path->state_wq.lock);
+ if (old_state)
+ *old_state = clt_path->state;
+ changed = rtrs_clt_change_state(clt_path, new_state);
+ spin_unlock_irq(&clt_path->state_wq.lock);
+
+ return changed;
+}
+
+static void rtrs_clt_hb_err_handler(struct rtrs_con *c)
+{
+ struct rtrs_clt_con *con = container_of(c, typeof(*con), c);
+
+ rtrs_rdma_error_recovery(con);
+}
+
+static void rtrs_clt_init_hb(struct rtrs_clt_path *clt_path)
+{
+ rtrs_init_hb(&clt_path->s, &io_comp_cqe,
+ RTRS_HB_INTERVAL_MS,
+ RTRS_HB_MISSED_MAX,
+ rtrs_clt_hb_err_handler,
+ rtrs_wq);
+}
+
+static void rtrs_clt_reconnect_work(struct work_struct *work);
+static void rtrs_clt_close_work(struct work_struct *work);
+
+static void rtrs_clt_err_recovery_work(struct work_struct *work)
+{
+ struct rtrs_clt_path *clt_path;
+ struct rtrs_clt_sess *clt;
+ int delay_ms;
+
+ clt_path = container_of(work, struct rtrs_clt_path, err_recovery_work);
+ clt = clt_path->clt;
+ delay_ms = clt->reconnect_delay_sec * 1000;
+ rtrs_clt_stop_and_destroy_conns(clt_path);
+ queue_delayed_work(rtrs_wq, &clt_path->reconnect_dwork,
+ msecs_to_jiffies(delay_ms +
+ prandom_u32_max(RTRS_RECONNECT_SEED)));
+}
+
+static struct rtrs_clt_path *alloc_path(struct rtrs_clt_sess *clt,
+ const struct rtrs_addr *path,
+ size_t con_num, u32 nr_poll_queues)
+{
+ struct rtrs_clt_path *clt_path;
+ int err = -ENOMEM;
+ int cpu;
+ size_t total_con;
+
+ clt_path = kzalloc(sizeof(*clt_path), GFP_KERNEL);
+ if (!clt_path)
+ goto err;
+
+ /*
+ * irqmode and poll
+ * +1: Extra connection for user messages
+ */
+ total_con = con_num + nr_poll_queues + 1;
+ clt_path->s.con = kcalloc(total_con, sizeof(*clt_path->s.con),
+ GFP_KERNEL);
+ if (!clt_path->s.con)
+ goto err_free_path;
+
+ clt_path->s.con_num = total_con;
+ clt_path->s.irq_con_num = con_num + 1;
+
+ clt_path->stats = kzalloc(sizeof(*clt_path->stats), GFP_KERNEL);
+ if (!clt_path->stats)
+ goto err_free_con;
+
+ mutex_init(&clt_path->init_mutex);
+ uuid_gen(&clt_path->s.uuid);
+ memcpy(&clt_path->s.dst_addr, path->dst,
+ rdma_addr_size((struct sockaddr *)path->dst));
+
+ /*
+ * rdma_resolve_addr() passes src_addr to cma_bind_addr, which
+ * checks the sa_family to be non-zero. If user passed src_addr=NULL
+ * the sess->src_addr will contain only zeros, which is then fine.
+ */
+ if (path->src)
+ memcpy(&clt_path->s.src_addr, path->src,
+ rdma_addr_size((struct sockaddr *)path->src));
+ strscpy(clt_path->s.sessname, clt->sessname,
+ sizeof(clt_path->s.sessname));
+ clt_path->clt = clt;
+ clt_path->max_pages_per_mr = RTRS_MAX_SEGMENTS;
+ init_waitqueue_head(&clt_path->state_wq);
+ clt_path->state = RTRS_CLT_CONNECTING;
+ atomic_set(&clt_path->connected_cnt, 0);
+ INIT_WORK(&clt_path->close_work, rtrs_clt_close_work);
+ INIT_WORK(&clt_path->err_recovery_work, rtrs_clt_err_recovery_work);
+ INIT_DELAYED_WORK(&clt_path->reconnect_dwork, rtrs_clt_reconnect_work);
+ rtrs_clt_init_hb(clt_path);
+
+ clt_path->mp_skip_entry = alloc_percpu(typeof(*clt_path->mp_skip_entry));
+ if (!clt_path->mp_skip_entry)
+ goto err_free_stats;
+
+ for_each_possible_cpu(cpu)
+ INIT_LIST_HEAD(per_cpu_ptr(clt_path->mp_skip_entry, cpu));
+
+ err = rtrs_clt_init_stats(clt_path->stats);
+ if (err)
+ goto err_free_percpu;
+
+ return clt_path;
+
+err_free_percpu:
+ free_percpu(clt_path->mp_skip_entry);
+err_free_stats:
+ kfree(clt_path->stats);
+err_free_con:
+ kfree(clt_path->s.con);
+err_free_path:
+ kfree(clt_path);
+err:
+ return ERR_PTR(err);
+}
+
+void free_path(struct rtrs_clt_path *clt_path)
+{
+ free_percpu(clt_path->mp_skip_entry);
+ mutex_destroy(&clt_path->init_mutex);
+ kfree(clt_path->s.con);
+ kfree(clt_path->rbufs);
+ kfree(clt_path);
+}
+
+static int create_con(struct rtrs_clt_path *clt_path, unsigned int cid)
+{
+ struct rtrs_clt_con *con;
+
+ con = kzalloc(sizeof(*con), GFP_KERNEL);
+ if (!con)
+ return -ENOMEM;
+
+ /* Map first two connections to the first CPU */
+ con->cpu = (cid ? cid - 1 : 0) % nr_cpu_ids;
+ con->c.cid = cid;
+ con->c.path = &clt_path->s;
+ /* Align with srv, init as 1 */
+ atomic_set(&con->c.wr_cnt, 1);
+ mutex_init(&con->con_mutex);
+
+ clt_path->s.con[cid] = &con->c;
+
+ return 0;
+}
+
+static void destroy_con(struct rtrs_clt_con *con)
+{
+ struct rtrs_clt_path *clt_path = to_clt_path(con->c.path);
+
+ clt_path->s.con[con->c.cid] = NULL;
+ mutex_destroy(&con->con_mutex);
+ kfree(con);
+}
+
+static int create_con_cq_qp(struct rtrs_clt_con *con)
+{
+ struct rtrs_clt_path *clt_path = to_clt_path(con->c.path);
+ u32 max_send_wr, max_recv_wr, cq_num, max_send_sge, wr_limit;
+ int err, cq_vector;
+ struct rtrs_msg_rkey_rsp *rsp;
+
+ lockdep_assert_held(&con->con_mutex);
+ if (con->c.cid == 0) {
+ max_send_sge = 1;
+ /* We must be the first here */
+ if (WARN_ON(clt_path->s.dev))
+ return -EINVAL;
+
+ /*
+ * The whole session uses device from user connection.
+ * Be careful not to close user connection before ib dev
+ * is gracefully put.
+ */
+ clt_path->s.dev = rtrs_ib_dev_find_or_add(con->c.cm_id->device,
+ &dev_pd);
+ if (!clt_path->s.dev) {
+ rtrs_wrn(clt_path->clt,
+ "rtrs_ib_dev_find_get_or_add(): no memory\n");
+ return -ENOMEM;
+ }
+ clt_path->s.dev_ref = 1;
+ query_fast_reg_mode(clt_path);
+ wr_limit = clt_path->s.dev->ib_dev->attrs.max_qp_wr;
+ /*
+ * Two (request + registration) completion for send
+ * Two for recv if always_invalidate is set on server
+ * or one for recv.
+ * + 2 for drain and heartbeat
+ * in case qp gets into error state.
+ */
+ max_send_wr =
+ min_t(int, wr_limit, SERVICE_CON_QUEUE_DEPTH * 2 + 2);
+ max_recv_wr = max_send_wr;
+ } else {
+ /*
+ * Here we assume that session members are correctly set.
+ * This is always true if user connection (cid == 0) is
+ * established first.
+ */
+ if (WARN_ON(!clt_path->s.dev))
+ return -EINVAL;
+ if (WARN_ON(!clt_path->queue_depth))
+ return -EINVAL;
+
+ wr_limit = clt_path->s.dev->ib_dev->attrs.max_qp_wr;
+ /* Shared between connections */
+ clt_path->s.dev_ref++;
+ max_send_wr = min_t(int, wr_limit,
+ /* QD * (REQ + RSP + FR REGS or INVS) + drain */
+ clt_path->queue_depth * 4 + 1);
+ max_recv_wr = min_t(int, wr_limit,
+ clt_path->queue_depth * 3 + 1);
+ max_send_sge = 2;
+ }
+ atomic_set(&con->c.sq_wr_avail, max_send_wr);
+ cq_num = max_send_wr + max_recv_wr;
+ /* alloc iu to recv new rkey reply when server reports flags set */
+ if (clt_path->flags & RTRS_MSG_NEW_RKEY_F || con->c.cid == 0) {
+ con->rsp_ius = rtrs_iu_alloc(cq_num, sizeof(*rsp),
+ GFP_KERNEL,
+ clt_path->s.dev->ib_dev,
+ DMA_FROM_DEVICE,
+ rtrs_clt_rdma_done);
+ if (!con->rsp_ius)
+ return -ENOMEM;
+ con->queue_num = cq_num;
+ }
+ cq_num = max_send_wr + max_recv_wr;
+ cq_vector = con->cpu % clt_path->s.dev->ib_dev->num_comp_vectors;
+ if (con->c.cid >= clt_path->s.irq_con_num)
+ err = rtrs_cq_qp_create(&clt_path->s, &con->c, max_send_sge,
+ cq_vector, cq_num, max_send_wr,
+ max_recv_wr, IB_POLL_DIRECT);
+ else
+ err = rtrs_cq_qp_create(&clt_path->s, &con->c, max_send_sge,
+ cq_vector, cq_num, max_send_wr,
+ max_recv_wr, IB_POLL_SOFTIRQ);
+ /*
+ * In case of error we do not bother to clean previous allocations,
+ * since destroy_con_cq_qp() must be called.
+ */
+ return err;
+}
+
+static void destroy_con_cq_qp(struct rtrs_clt_con *con)
+{
+ struct rtrs_clt_path *clt_path = to_clt_path(con->c.path);
+
+ /*
+ * Be careful here: destroy_con_cq_qp() can be called even
+ * create_con_cq_qp() failed, see comments there.
+ */
+ lockdep_assert_held(&con->con_mutex);
+ rtrs_cq_qp_destroy(&con->c);
+ if (con->rsp_ius) {
+ rtrs_iu_free(con->rsp_ius, clt_path->s.dev->ib_dev,
+ con->queue_num);
+ con->rsp_ius = NULL;
+ con->queue_num = 0;
+ }
+ if (clt_path->s.dev_ref && !--clt_path->s.dev_ref) {
+ rtrs_ib_dev_put(clt_path->s.dev);
+ clt_path->s.dev = NULL;
+ }
+}
+
+static void stop_cm(struct rtrs_clt_con *con)
+{
+ rdma_disconnect(con->c.cm_id);
+ if (con->c.qp)
+ ib_drain_qp(con->c.qp);
+}
+
+static void destroy_cm(struct rtrs_clt_con *con)
+{
+ rdma_destroy_id(con->c.cm_id);
+ con->c.cm_id = NULL;
+}
+
+static int rtrs_rdma_addr_resolved(struct rtrs_clt_con *con)
+{
+ struct rtrs_path *s = con->c.path;
+ int err;
+
+ mutex_lock(&con->con_mutex);
+ err = create_con_cq_qp(con);
+ mutex_unlock(&con->con_mutex);
+ if (err) {
+ rtrs_err(s, "create_con_cq_qp(), err: %d\n", err);
+ return err;
+ }
+ err = rdma_resolve_route(con->c.cm_id, RTRS_CONNECT_TIMEOUT_MS);
+ if (err)
+ rtrs_err(s, "Resolving route failed, err: %d\n", err);
+
+ return err;
+}
+
+static int rtrs_rdma_route_resolved(struct rtrs_clt_con *con)
+{
+ struct rtrs_clt_path *clt_path = to_clt_path(con->c.path);
+ struct rtrs_clt_sess *clt = clt_path->clt;
+ struct rtrs_msg_conn_req msg;
+ struct rdma_conn_param param;
+
+ int err;
+
+ param = (struct rdma_conn_param) {
+ .retry_count = 7,
+ .rnr_retry_count = 7,
+ .private_data = &msg,
+ .private_data_len = sizeof(msg),
+ };
+
+ msg = (struct rtrs_msg_conn_req) {
+ .magic = cpu_to_le16(RTRS_MAGIC),
+ .version = cpu_to_le16(RTRS_PROTO_VER),
+ .cid = cpu_to_le16(con->c.cid),
+ .cid_num = cpu_to_le16(clt_path->s.con_num),
+ .recon_cnt = cpu_to_le16(clt_path->s.recon_cnt),
+ };
+ msg.first_conn = clt_path->for_new_clt ? FIRST_CONN : 0;
+ uuid_copy(&msg.sess_uuid, &clt_path->s.uuid);
+ uuid_copy(&msg.paths_uuid, &clt->paths_uuid);
+
+ err = rdma_connect_locked(con->c.cm_id, &param);
+ if (err)
+ rtrs_err(clt, "rdma_connect_locked(): %d\n", err);
+
+ return err;
+}
+
+static int rtrs_rdma_conn_established(struct rtrs_clt_con *con,
+ struct rdma_cm_event *ev)
+{
+ struct rtrs_clt_path *clt_path = to_clt_path(con->c.path);
+ struct rtrs_clt_sess *clt = clt_path->clt;
+ const struct rtrs_msg_conn_rsp *msg;
+ u16 version, queue_depth;
+ int errno;
+ u8 len;
+
+ msg = ev->param.conn.private_data;
+ len = ev->param.conn.private_data_len;
+ if (len < sizeof(*msg)) {
+ rtrs_err(clt, "Invalid RTRS connection response\n");
+ return -ECONNRESET;
+ }
+ if (le16_to_cpu(msg->magic) != RTRS_MAGIC) {
+ rtrs_err(clt, "Invalid RTRS magic\n");
+ return -ECONNRESET;
+ }
+ version = le16_to_cpu(msg->version);
+ if (version >> 8 != RTRS_PROTO_VER_MAJOR) {
+ rtrs_err(clt, "Unsupported major RTRS version: %d, expected %d\n",
+ version >> 8, RTRS_PROTO_VER_MAJOR);
+ return -ECONNRESET;
+ }
+ errno = le16_to_cpu(msg->errno);
+ if (errno) {
+ rtrs_err(clt, "Invalid RTRS message: errno %d\n",
+ errno);
+ return -ECONNRESET;
+ }
+ if (con->c.cid == 0) {
+ queue_depth = le16_to_cpu(msg->queue_depth);
+
+ if (clt_path->queue_depth > 0 && queue_depth != clt_path->queue_depth) {
+ rtrs_err(clt, "Error: queue depth changed\n");
+
+ /*
+ * Stop any more reconnection attempts
+ */
+ clt_path->reconnect_attempts = -1;
+ rtrs_err(clt,
+ "Disabling auto-reconnect. Trigger a manual reconnect after issue is resolved\n");
+ return -ECONNRESET;
+ }
+
+ if (!clt_path->rbufs) {
+ clt_path->rbufs = kcalloc(queue_depth,
+ sizeof(*clt_path->rbufs),
+ GFP_KERNEL);
+ if (!clt_path->rbufs)
+ return -ENOMEM;
+ }
+ clt_path->queue_depth = queue_depth;
+ clt_path->s.signal_interval = min_not_zero(queue_depth,
+ (unsigned short) SERVICE_CON_QUEUE_DEPTH);
+ clt_path->max_hdr_size = le32_to_cpu(msg->max_hdr_size);
+ clt_path->max_io_size = le32_to_cpu(msg->max_io_size);
+ clt_path->flags = le32_to_cpu(msg->flags);
+ clt_path->chunk_size = clt_path->max_io_size + clt_path->max_hdr_size;
+
+ /*
+ * Global IO size is always a minimum.
+ * If while a reconnection server sends us a value a bit
+ * higher - client does not care and uses cached minimum.
+ *
+ * Since we can have several sessions (paths) restablishing
+ * connections in parallel, use lock.
+ */
+ mutex_lock(&clt->paths_mutex);
+ clt->queue_depth = clt_path->queue_depth;
+ clt->max_io_size = min_not_zero(clt_path->max_io_size,
+ clt->max_io_size);
+ mutex_unlock(&clt->paths_mutex);
+
+ /*
+ * Cache the hca_port and hca_name for sysfs
+ */
+ clt_path->hca_port = con->c.cm_id->port_num;
+ scnprintf(clt_path->hca_name, sizeof(clt_path->hca_name),
+ clt_path->s.dev->ib_dev->name);
+ clt_path->s.src_addr = con->c.cm_id->route.addr.src_addr;
+ /* set for_new_clt, to allow future reconnect on any path */
+ clt_path->for_new_clt = 1;
+ }
+
+ return 0;
+}
+
+static inline void flag_success_on_conn(struct rtrs_clt_con *con)
+{
+ struct rtrs_clt_path *clt_path = to_clt_path(con->c.path);
+
+ atomic_inc(&clt_path->connected_cnt);
+ con->cm_err = 1;
+}
+
+static int rtrs_rdma_conn_rejected(struct rtrs_clt_con *con,
+ struct rdma_cm_event *ev)
+{
+ struct rtrs_path *s = con->c.path;
+ const struct rtrs_msg_conn_rsp *msg;
+ const char *rej_msg;
+ int status, errno;
+ u8 data_len;
+
+ status = ev->status;
+ rej_msg = rdma_reject_msg(con->c.cm_id, status);
+ msg = rdma_consumer_reject_data(con->c.cm_id, ev, &data_len);
+
+ if (msg && data_len >= sizeof(*msg)) {
+ errno = (int16_t)le16_to_cpu(msg->errno);
+ if (errno == -EBUSY)
+ rtrs_err(s,
+ "Previous session is still exists on the server, please reconnect later\n");
+ else
+ rtrs_err(s,
+ "Connect rejected: status %d (%s), rtrs errno %d\n",
+ status, rej_msg, errno);
+ } else {
+ rtrs_err(s,
+ "Connect rejected but with malformed message: status %d (%s)\n",
+ status, rej_msg);
+ }
+
+ return -ECONNRESET;
+}
+
+void rtrs_clt_close_conns(struct rtrs_clt_path *clt_path, bool wait)
+{
+ trace_rtrs_clt_close_conns(clt_path);
+
+ if (rtrs_clt_change_state_get_old(clt_path, RTRS_CLT_CLOSING, NULL))
+ queue_work(rtrs_wq, &clt_path->close_work);
+ if (wait)
+ flush_work(&clt_path->close_work);
+}
+
+static inline void flag_error_on_conn(struct rtrs_clt_con *con, int cm_err)
+{
+ if (con->cm_err == 1) {
+ struct rtrs_clt_path *clt_path;
+
+ clt_path = to_clt_path(con->c.path);
+ if (atomic_dec_and_test(&clt_path->connected_cnt))
+
+ wake_up(&clt_path->state_wq);
+ }
+ con->cm_err = cm_err;
+}
+
+static int rtrs_clt_rdma_cm_handler(struct rdma_cm_id *cm_id,
+ struct rdma_cm_event *ev)
+{
+ struct rtrs_clt_con *con = cm_id->context;
+ struct rtrs_path *s = con->c.path;
+ struct rtrs_clt_path *clt_path = to_clt_path(s);
+ int cm_err = 0;
+
+ switch (ev->event) {
+ case RDMA_CM_EVENT_ADDR_RESOLVED:
+ cm_err = rtrs_rdma_addr_resolved(con);
+ break;
+ case RDMA_CM_EVENT_ROUTE_RESOLVED:
+ cm_err = rtrs_rdma_route_resolved(con);
+ break;
+ case RDMA_CM_EVENT_ESTABLISHED:
+ cm_err = rtrs_rdma_conn_established(con, ev);
+ if (!cm_err) {
+ /*
+ * Report success and wake up. Here we abuse state_wq,
+ * i.e. wake up without state change, but we set cm_err.
+ */
+ flag_success_on_conn(con);
+ wake_up(&clt_path->state_wq);
+ return 0;
+ }
+ break;
+ case RDMA_CM_EVENT_REJECTED:
+ cm_err = rtrs_rdma_conn_rejected(con, ev);
+ break;
+ case RDMA_CM_EVENT_DISCONNECTED:
+ /* No message for disconnecting */
+ cm_err = -ECONNRESET;
+ break;
+ case RDMA_CM_EVENT_CONNECT_ERROR:
+ case RDMA_CM_EVENT_UNREACHABLE:
+ case RDMA_CM_EVENT_ADDR_CHANGE:
+ case RDMA_CM_EVENT_TIMEWAIT_EXIT:
+ rtrs_wrn(s, "CM error (CM event: %s, err: %d)\n",
+ rdma_event_msg(ev->event), ev->status);
+ cm_err = -ECONNRESET;
+ break;
+ case RDMA_CM_EVENT_ADDR_ERROR:
+ case RDMA_CM_EVENT_ROUTE_ERROR:
+ rtrs_wrn(s, "CM error (CM event: %s, err: %d)\n",
+ rdma_event_msg(ev->event), ev->status);
+ cm_err = -EHOSTUNREACH;
+ break;
+ case RDMA_CM_EVENT_DEVICE_REMOVAL:
+ /*
+ * Device removal is a special case. Queue close and return 0.
+ */
+ rtrs_clt_close_conns(clt_path, false);
+ return 0;
+ default:
+ rtrs_err(s, "Unexpected RDMA CM error (CM event: %s, err: %d)\n",
+ rdma_event_msg(ev->event), ev->status);
+ cm_err = -ECONNRESET;
+ break;
+ }
+
+ if (cm_err) {
+ /*
+ * cm error makes sense only on connection establishing,
+ * in other cases we rely on normal procedure of reconnecting.
+ */
+ flag_error_on_conn(con, cm_err);
+ rtrs_rdma_error_recovery(con);
+ }
+
+ return 0;
+}
+
+/* The caller should do the cleanup in case of error */
+static int create_cm(struct rtrs_clt_con *con)
+{
+ struct rtrs_path *s = con->c.path;
+ struct rtrs_clt_path *clt_path = to_clt_path(s);
+ struct rdma_cm_id *cm_id;
+ int err;
+
+ cm_id = rdma_create_id(&init_net, rtrs_clt_rdma_cm_handler, con,
+ clt_path->s.dst_addr.ss_family == AF_IB ?
+ RDMA_PS_IB : RDMA_PS_TCP, IB_QPT_RC);
+ if (IS_ERR(cm_id)) {
+ err = PTR_ERR(cm_id);
+ rtrs_err(s, "Failed to create CM ID, err: %d\n", err);
+
+ return err;
+ }
+ con->c.cm_id = cm_id;
+ con->cm_err = 0;
+ /* allow the port to be reused */
+ err = rdma_set_reuseaddr(cm_id, 1);
+ if (err != 0) {
+ rtrs_err(s, "Set address reuse failed, err: %d\n", err);
+ return err;
+ }
+ err = rdma_resolve_addr(cm_id, (struct sockaddr *)&clt_path->s.src_addr,
+ (struct sockaddr *)&clt_path->s.dst_addr,
+ RTRS_CONNECT_TIMEOUT_MS);
+ if (err) {
+ rtrs_err(s, "Failed to resolve address, err: %d\n", err);
+ return err;
+ }
+ /*
+ * Combine connection status and session events. This is needed
+ * for waiting two possible cases: cm_err has something meaningful
+ * or session state was really changed to error by device removal.
+ */
+ err = wait_event_interruptible_timeout(
+ clt_path->state_wq,
+ con->cm_err || clt_path->state != RTRS_CLT_CONNECTING,
+ msecs_to_jiffies(RTRS_CONNECT_TIMEOUT_MS));
+ if (err == 0 || err == -ERESTARTSYS) {
+ if (err == 0)
+ err = -ETIMEDOUT;
+ /* Timedout or interrupted */
+ return err;
+ }
+ if (con->cm_err < 0)
+ return con->cm_err;
+ if (READ_ONCE(clt_path->state) != RTRS_CLT_CONNECTING)
+ /* Device removal */
+ return -ECONNABORTED;
+
+ return 0;
+}
+
+static void rtrs_clt_path_up(struct rtrs_clt_path *clt_path)
+{
+ struct rtrs_clt_sess *clt = clt_path->clt;
+ int up;
+
+ /*
+ * We can fire RECONNECTED event only when all paths were
+ * connected on rtrs_clt_open(), then each was disconnected
+ * and the first one connected again. That's why this nasty
+ * game with counter value.
+ */
+
+ mutex_lock(&clt->paths_ev_mutex);
+ up = ++clt->paths_up;
+ /*
+ * Here it is safe to access paths num directly since up counter
+ * is greater than MAX_PATHS_NUM only while rtrs_clt_open() is
+ * in progress, thus paths removals are impossible.
+ */
+ if (up > MAX_PATHS_NUM && up == MAX_PATHS_NUM + clt->paths_num)
+ clt->paths_up = clt->paths_num;
+ else if (up == 1)
+ clt->link_ev(clt->priv, RTRS_CLT_LINK_EV_RECONNECTED);
+ mutex_unlock(&clt->paths_ev_mutex);
+
+ /* Mark session as established */
+ clt_path->established = true;
+ clt_path->reconnect_attempts = 0;
+ clt_path->stats->reconnects.successful_cnt++;
+}
+
+static void rtrs_clt_path_down(struct rtrs_clt_path *clt_path)
+{
+ struct rtrs_clt_sess *clt = clt_path->clt;
+
+ if (!clt_path->established)
+ return;
+
+ clt_path->established = false;
+ mutex_lock(&clt->paths_ev_mutex);
+ WARN_ON(!clt->paths_up);
+ if (--clt->paths_up == 0)
+ clt->link_ev(clt->priv, RTRS_CLT_LINK_EV_DISCONNECTED);
+ mutex_unlock(&clt->paths_ev_mutex);
+}
+
+static void rtrs_clt_stop_and_destroy_conns(struct rtrs_clt_path *clt_path)
+{
+ struct rtrs_clt_con *con;
+ unsigned int cid;
+
+ WARN_ON(READ_ONCE(clt_path->state) == RTRS_CLT_CONNECTED);
+
+ /*
+ * Possible race with rtrs_clt_open(), when DEVICE_REMOVAL comes
+ * exactly in between. Start destroying after it finishes.
+ */
+ mutex_lock(&clt_path->init_mutex);
+ mutex_unlock(&clt_path->init_mutex);
+
+ /*
+ * All IO paths must observe !CONNECTED state before we
+ * free everything.
+ */
+ synchronize_rcu();
+
+ rtrs_stop_hb(&clt_path->s);
+
+ /*
+ * The order it utterly crucial: firstly disconnect and complete all
+ * rdma requests with error (thus set in_use=false for requests),
+ * then fail outstanding requests checking in_use for each, and
+ * eventually notify upper layer about session disconnection.
+ */
+
+ for (cid = 0; cid < clt_path->s.con_num; cid++) {
+ if (!clt_path->s.con[cid])
+ break;
+ con = to_clt_con(clt_path->s.con[cid]);
+ stop_cm(con);
+ }
+ fail_all_outstanding_reqs(clt_path);
+ free_path_reqs(clt_path);
+ rtrs_clt_path_down(clt_path);
+
+ /*
+ * Wait for graceful shutdown, namely when peer side invokes
+ * rdma_disconnect(). 'connected_cnt' is decremented only on
+ * CM events, thus if other side had crashed and hb has detected
+ * something is wrong, here we will stuck for exactly timeout ms,
+ * since CM does not fire anything. That is fine, we are not in
+ * hurry.
+ */
+ wait_event_timeout(clt_path->state_wq,
+ !atomic_read(&clt_path->connected_cnt),
+ msecs_to_jiffies(RTRS_CONNECT_TIMEOUT_MS));
+
+ for (cid = 0; cid < clt_path->s.con_num; cid++) {
+ if (!clt_path->s.con[cid])
+ break;
+ con = to_clt_con(clt_path->s.con[cid]);
+ mutex_lock(&con->con_mutex);
+ destroy_con_cq_qp(con);
+ mutex_unlock(&con->con_mutex);
+ destroy_cm(con);
+ destroy_con(con);
+ }
+}
+
+static void rtrs_clt_remove_path_from_arr(struct rtrs_clt_path *clt_path)
+{
+ struct rtrs_clt_sess *clt = clt_path->clt;
+ struct rtrs_clt_path *next;
+ bool wait_for_grace = false;
+ int cpu;
+
+ mutex_lock(&clt->paths_mutex);
+ list_del_rcu(&clt_path->s.entry);
+
+ /* Make sure everybody observes path removal. */
+ synchronize_rcu();
+
+ /*
+ * At this point nobody sees @sess in the list, but still we have
+ * dangling pointer @pcpu_path which _can_ point to @sess. Since
+ * nobody can observe @sess in the list, we guarantee that IO path
+ * will not assign @sess to @pcpu_path, i.e. @pcpu_path can be equal
+ * to @sess, but can never again become @sess.
+ */
+
+ /*
+ * Decrement paths number only after grace period, because
+ * caller of do_each_path() must firstly observe list without
+ * path and only then decremented paths number.
+ *
+ * Otherwise there can be the following situation:
+ * o Two paths exist and IO is coming.
+ * o One path is removed:
+ * CPU#0 CPU#1
+ * do_each_path(): rtrs_clt_remove_path_from_arr():
+ * path = get_next_path()
+ * ^^^ list_del_rcu(path)
+ * [!CONNECTED path] clt->paths_num--
+ * ^^^^^^^^^
+ * load clt->paths_num from 2 to 1
+ * ^^^^^^^^^
+ * sees 1
+ *
+ * path is observed as !CONNECTED, but do_each_path() loop
+ * ends, because expression i < clt->paths_num is false.
+ */
+ clt->paths_num--;
+
+ /*
+ * Get @next connection from current @sess which is going to be
+ * removed. If @sess is the last element, then @next is NULL.
+ */
+ rcu_read_lock();
+ next = rtrs_clt_get_next_path_or_null(&clt->paths_list, clt_path);
+ rcu_read_unlock();
+
+ /*
+ * @pcpu paths can still point to the path which is going to be
+ * removed, so change the pointer manually.
+ */
+ for_each_possible_cpu(cpu) {
+ struct rtrs_clt_path __rcu **ppcpu_path;
+
+ ppcpu_path = per_cpu_ptr(clt->pcpu_path, cpu);
+ if (rcu_dereference_protected(*ppcpu_path,
+ lockdep_is_held(&clt->paths_mutex)) != clt_path)
+ /*
+ * synchronize_rcu() was called just after deleting
+ * entry from the list, thus IO code path cannot
+ * change pointer back to the pointer which is going
+ * to be removed, we are safe here.
+ */
+ continue;
+
+ /*
+ * We race with IO code path, which also changes pointer,
+ * thus we have to be careful not to overwrite it.
+ */
+ if (try_cmpxchg((struct rtrs_clt_path **)ppcpu_path, &clt_path,
+ next))
+ /*
+ * @ppcpu_path was successfully replaced with @next,
+ * that means that someone could also pick up the
+ * @sess and dereferencing it right now, so wait for
+ * a grace period is required.
+ */
+ wait_for_grace = true;
+ }
+ if (wait_for_grace)
+ synchronize_rcu();
+
+ mutex_unlock(&clt->paths_mutex);
+}
+
+static void rtrs_clt_add_path_to_arr(struct rtrs_clt_path *clt_path)
+{
+ struct rtrs_clt_sess *clt = clt_path->clt;
+
+ mutex_lock(&clt->paths_mutex);
+ clt->paths_num++;
+
+ list_add_tail_rcu(&clt_path->s.entry, &clt->paths_list);
+ mutex_unlock(&clt->paths_mutex);
+}
+
+static void rtrs_clt_close_work(struct work_struct *work)
+{
+ struct rtrs_clt_path *clt_path;
+
+ clt_path = container_of(work, struct rtrs_clt_path, close_work);
+
+ cancel_work_sync(&clt_path->err_recovery_work);
+ cancel_delayed_work_sync(&clt_path->reconnect_dwork);
+ rtrs_clt_stop_and_destroy_conns(clt_path);
+ rtrs_clt_change_state_get_old(clt_path, RTRS_CLT_CLOSED, NULL);
+}
+
+static int init_conns(struct rtrs_clt_path *clt_path)
+{
+ unsigned int cid;
+ int err, i;
+
+ /*
+ * On every new session connections increase reconnect counter
+ * to avoid clashes with previous sessions not yet closed
+ * sessions on a server side.
+ */
+ clt_path->s.recon_cnt++;
+
+ /* Establish all RDMA connections */
+ for (cid = 0; cid < clt_path->s.con_num; cid++) {
+ err = create_con(clt_path, cid);
+ if (err)
+ goto destroy;
+
+ err = create_cm(to_clt_con(clt_path->s.con[cid]));
+ if (err)
+ goto destroy;
+ }
+ err = alloc_path_reqs(clt_path);
+ if (err)
+ goto destroy;
+
+ return 0;
+
+destroy:
+ /* Make sure we do the cleanup in the order they are created */
+ for (i = 0; i <= cid; i++) {
+ struct rtrs_clt_con *con;
+
+ if (!clt_path->s.con[i])
+ break;
+
+ con = to_clt_con(clt_path->s.con[i]);
+ if (con->c.cm_id) {
+ stop_cm(con);
+ mutex_lock(&con->con_mutex);
+ destroy_con_cq_qp(con);
+ mutex_unlock(&con->con_mutex);
+ destroy_cm(con);
+ }
+ destroy_con(con);
+ }
+ /*
+ * If we've never taken async path and got an error, say,
+ * doing rdma_resolve_addr(), switch to CONNECTION_ERR state
+ * manually to keep reconnecting.
+ */
+ rtrs_clt_change_state_get_old(clt_path, RTRS_CLT_CONNECTING_ERR, NULL);
+
+ return err;
+}
+
+static void rtrs_clt_info_req_done(struct ib_cq *cq, struct ib_wc *wc)
+{
+ struct rtrs_clt_con *con = to_clt_con(wc->qp->qp_context);
+ struct rtrs_clt_path *clt_path = to_clt_path(con->c.path);
+ struct rtrs_iu *iu;
+
+ iu = container_of(wc->wr_cqe, struct rtrs_iu, cqe);
+ rtrs_iu_free(iu, clt_path->s.dev->ib_dev, 1);
+
+ if (wc->status != IB_WC_SUCCESS) {
+ rtrs_err(clt_path->clt, "Path info request send failed: %s\n",
+ ib_wc_status_msg(wc->status));
+ rtrs_clt_change_state_get_old(clt_path, RTRS_CLT_CONNECTING_ERR, NULL);
+ return;
+ }
+
+ rtrs_clt_update_wc_stats(con);
+}
+
+static int process_info_rsp(struct rtrs_clt_path *clt_path,
+ const struct rtrs_msg_info_rsp *msg)
+{
+ unsigned int sg_cnt, total_len;
+ int i, sgi;
+
+ sg_cnt = le16_to_cpu(msg->sg_cnt);
+ if (!sg_cnt || (clt_path->queue_depth % sg_cnt)) {
+ rtrs_err(clt_path->clt,
+ "Incorrect sg_cnt %d, is not multiple\n",
+ sg_cnt);
+ return -EINVAL;
+ }
+
+ /*
+ * Check if IB immediate data size is enough to hold the mem_id and
+ * the offset inside the memory chunk.
+ */
+ if ((ilog2(sg_cnt - 1) + 1) + (ilog2(clt_path->chunk_size - 1) + 1) >
+ MAX_IMM_PAYL_BITS) {
+ rtrs_err(clt_path->clt,
+ "RDMA immediate size (%db) not enough to encode %d buffers of size %dB\n",
+ MAX_IMM_PAYL_BITS, sg_cnt, clt_path->chunk_size);
+ return -EINVAL;
+ }
+ total_len = 0;
+ for (sgi = 0, i = 0; sgi < sg_cnt && i < clt_path->queue_depth; sgi++) {
+ const struct rtrs_sg_desc *desc = &msg->desc[sgi];
+ u32 len, rkey;
+ u64 addr;
+
+ addr = le64_to_cpu(desc->addr);
+ rkey = le32_to_cpu(desc->key);
+ len = le32_to_cpu(desc->len);
+
+ total_len += len;
+
+ if (!len || (len % clt_path->chunk_size)) {
+ rtrs_err(clt_path->clt, "Incorrect [%d].len %d\n",
+ sgi,
+ len);
+ return -EINVAL;
+ }
+ for ( ; len && i < clt_path->queue_depth; i++) {
+ clt_path->rbufs[i].addr = addr;
+ clt_path->rbufs[i].rkey = rkey;
+
+ len -= clt_path->chunk_size;
+ addr += clt_path->chunk_size;
+ }
+ }
+ /* Sanity check */
+ if (sgi != sg_cnt || i != clt_path->queue_depth) {
+ rtrs_err(clt_path->clt,
+ "Incorrect sg vector, not fully mapped\n");
+ return -EINVAL;
+ }
+ if (total_len != clt_path->chunk_size * clt_path->queue_depth) {
+ rtrs_err(clt_path->clt, "Incorrect total_len %d\n", total_len);
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static void rtrs_clt_info_rsp_done(struct ib_cq *cq, struct ib_wc *wc)
+{
+ struct rtrs_clt_con *con = to_clt_con(wc->qp->qp_context);
+ struct rtrs_clt_path *clt_path = to_clt_path(con->c.path);
+ struct rtrs_msg_info_rsp *msg;
+ enum rtrs_clt_state state;
+ struct rtrs_iu *iu;
+ size_t rx_sz;
+ int err;
+
+ state = RTRS_CLT_CONNECTING_ERR;
+
+ WARN_ON(con->c.cid);
+ iu = container_of(wc->wr_cqe, struct rtrs_iu, cqe);
+ if (wc->status != IB_WC_SUCCESS) {
+ rtrs_err(clt_path->clt, "Path info response recv failed: %s\n",
+ ib_wc_status_msg(wc->status));
+ goto out;
+ }
+ WARN_ON(wc->opcode != IB_WC_RECV);
+
+ if (wc->byte_len < sizeof(*msg)) {
+ rtrs_err(clt_path->clt, "Path info response is malformed: size %d\n",
+ wc->byte_len);
+ goto out;
+ }
+ ib_dma_sync_single_for_cpu(clt_path->s.dev->ib_dev, iu->dma_addr,
+ iu->size, DMA_FROM_DEVICE);
+ msg = iu->buf;
+ if (le16_to_cpu(msg->type) != RTRS_MSG_INFO_RSP) {
+ rtrs_err(clt_path->clt, "Path info response is malformed: type %d\n",
+ le16_to_cpu(msg->type));
+ goto out;
+ }
+ rx_sz = sizeof(*msg);
+ rx_sz += sizeof(msg->desc[0]) * le16_to_cpu(msg->sg_cnt);
+ if (wc->byte_len < rx_sz) {
+ rtrs_err(clt_path->clt, "Path info response is malformed: size %d\n",
+ wc->byte_len);
+ goto out;
+ }
+ err = process_info_rsp(clt_path, msg);
+ if (err)
+ goto out;
+
+ err = post_recv_path(clt_path);
+ if (err)
+ goto out;
+
+ state = RTRS_CLT_CONNECTED;
+
+out:
+ rtrs_clt_update_wc_stats(con);
+ rtrs_iu_free(iu, clt_path->s.dev->ib_dev, 1);
+ rtrs_clt_change_state_get_old(clt_path, state, NULL);
+}
+
+static int rtrs_send_path_info(struct rtrs_clt_path *clt_path)
+{
+ struct rtrs_clt_con *usr_con = to_clt_con(clt_path->s.con[0]);
+ struct rtrs_msg_info_req *msg;
+ struct rtrs_iu *tx_iu, *rx_iu;
+ size_t rx_sz;
+ int err;
+
+ rx_sz = sizeof(struct rtrs_msg_info_rsp);
+ rx_sz += sizeof(struct rtrs_sg_desc) * clt_path->queue_depth;
+
+ tx_iu = rtrs_iu_alloc(1, sizeof(struct rtrs_msg_info_req), GFP_KERNEL,
+ clt_path->s.dev->ib_dev, DMA_TO_DEVICE,
+ rtrs_clt_info_req_done);
+ rx_iu = rtrs_iu_alloc(1, rx_sz, GFP_KERNEL, clt_path->s.dev->ib_dev,
+ DMA_FROM_DEVICE, rtrs_clt_info_rsp_done);
+ if (!tx_iu || !rx_iu) {
+ err = -ENOMEM;
+ goto out;
+ }
+ /* Prepare for getting info response */
+ err = rtrs_iu_post_recv(&usr_con->c, rx_iu);
+ if (err) {
+ rtrs_err(clt_path->clt, "rtrs_iu_post_recv(), err: %d\n", err);
+ goto out;
+ }
+ rx_iu = NULL;
+
+ msg = tx_iu->buf;
+ msg->type = cpu_to_le16(RTRS_MSG_INFO_REQ);
+ memcpy(msg->pathname, clt_path->s.sessname, sizeof(msg->pathname));
+
+ ib_dma_sync_single_for_device(clt_path->s.dev->ib_dev,
+ tx_iu->dma_addr,
+ tx_iu->size, DMA_TO_DEVICE);
+
+ /* Send info request */
+ err = rtrs_iu_post_send(&usr_con->c, tx_iu, sizeof(*msg), NULL);
+ if (err) {
+ rtrs_err(clt_path->clt, "rtrs_iu_post_send(), err: %d\n", err);
+ goto out;
+ }
+ tx_iu = NULL;
+
+ /* Wait for state change */
+ wait_event_interruptible_timeout(clt_path->state_wq,
+ clt_path->state != RTRS_CLT_CONNECTING,
+ msecs_to_jiffies(
+ RTRS_CONNECT_TIMEOUT_MS));
+ if (READ_ONCE(clt_path->state) != RTRS_CLT_CONNECTED) {
+ if (READ_ONCE(clt_path->state) == RTRS_CLT_CONNECTING_ERR)
+ err = -ECONNRESET;
+ else
+ err = -ETIMEDOUT;
+ }
+
+out:
+ if (tx_iu)
+ rtrs_iu_free(tx_iu, clt_path->s.dev->ib_dev, 1);
+ if (rx_iu)
+ rtrs_iu_free(rx_iu, clt_path->s.dev->ib_dev, 1);
+ if (err)
+ /* If we've never taken async path because of malloc problems */
+ rtrs_clt_change_state_get_old(clt_path,
+ RTRS_CLT_CONNECTING_ERR, NULL);
+
+ return err;
+}
+
+/**
+ * init_path() - establishes all path connections and does handshake
+ * @clt_path: client path.
+ * In case of error full close or reconnect procedure should be taken,
+ * because reconnect or close async works can be started.
+ */
+static int init_path(struct rtrs_clt_path *clt_path)
+{
+ int err;
+ char str[NAME_MAX];
+ struct rtrs_addr path = {
+ .src = &clt_path->s.src_addr,
+ .dst = &clt_path->s.dst_addr,
+ };
+
+ rtrs_addr_to_str(&path, str, sizeof(str));
+
+ mutex_lock(&clt_path->init_mutex);
+ err = init_conns(clt_path);
+ if (err) {
+ rtrs_err(clt_path->clt,
+ "init_conns() failed: err=%d path=%s [%s:%u]\n", err,
+ str, clt_path->hca_name, clt_path->hca_port);
+ goto out;
+ }
+ err = rtrs_send_path_info(clt_path);
+ if (err) {
+ rtrs_err(clt_path->clt,
+ "rtrs_send_path_info() failed: err=%d path=%s [%s:%u]\n",
+ err, str, clt_path->hca_name, clt_path->hca_port);
+ goto out;
+ }
+ rtrs_clt_path_up(clt_path);
+ rtrs_start_hb(&clt_path->s);
+out:
+ mutex_unlock(&clt_path->init_mutex);
+
+ return err;
+}
+
+static void rtrs_clt_reconnect_work(struct work_struct *work)
+{
+ struct rtrs_clt_path *clt_path;
+ struct rtrs_clt_sess *clt;
+ int err;
+
+ clt_path = container_of(to_delayed_work(work), struct rtrs_clt_path,
+ reconnect_dwork);
+ clt = clt_path->clt;
+
+ trace_rtrs_clt_reconnect_work(clt_path);
+
+ if (READ_ONCE(clt_path->state) != RTRS_CLT_RECONNECTING)
+ return;
+
+ if (clt_path->reconnect_attempts >= clt->max_reconnect_attempts) {
+ /* Close a path completely if max attempts is reached */
+ rtrs_clt_close_conns(clt_path, false);
+ return;
+ }
+ clt_path->reconnect_attempts++;
+
+ msleep(RTRS_RECONNECT_BACKOFF);
+ if (rtrs_clt_change_state_get_old(clt_path, RTRS_CLT_CONNECTING, NULL)) {
+ err = init_path(clt_path);
+ if (err)
+ goto reconnect_again;
+ }
+
+ return;
+
+reconnect_again:
+ if (rtrs_clt_change_state_get_old(clt_path, RTRS_CLT_RECONNECTING, NULL)) {
+ clt_path->stats->reconnects.fail_cnt++;
+ queue_work(rtrs_wq, &clt_path->err_recovery_work);
+ }
+}
+
+static void rtrs_clt_dev_release(struct device *dev)
+{
+ struct rtrs_clt_sess *clt = container_of(dev, struct rtrs_clt_sess,
+ dev);
+
+ mutex_destroy(&clt->paths_ev_mutex);
+ mutex_destroy(&clt->paths_mutex);
+ kfree(clt);
+}
+
+static struct rtrs_clt_sess *alloc_clt(const char *sessname, size_t paths_num,
+ u16 port, size_t pdu_sz, void *priv,
+ void (*link_ev)(void *priv,
+ enum rtrs_clt_link_ev ev),
+ unsigned int reconnect_delay_sec,
+ unsigned int max_reconnect_attempts)
+{
+ struct rtrs_clt_sess *clt;
+ int err;
+
+ if (!paths_num || paths_num > MAX_PATHS_NUM)
+ return ERR_PTR(-EINVAL);
+
+ if (strlen(sessname) >= sizeof(clt->sessname))
+ return ERR_PTR(-EINVAL);
+
+ clt = kzalloc(sizeof(*clt), GFP_KERNEL);
+ if (!clt)
+ return ERR_PTR(-ENOMEM);
+
+ clt->pcpu_path = alloc_percpu(typeof(*clt->pcpu_path));
+ if (!clt->pcpu_path) {
+ kfree(clt);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ clt->dev.class = rtrs_clt_dev_class;
+ clt->dev.release = rtrs_clt_dev_release;
+ uuid_gen(&clt->paths_uuid);
+ INIT_LIST_HEAD_RCU(&clt->paths_list);
+ clt->paths_num = paths_num;
+ clt->paths_up = MAX_PATHS_NUM;
+ clt->port = port;
+ clt->pdu_sz = pdu_sz;
+ clt->max_segments = RTRS_MAX_SEGMENTS;
+ clt->reconnect_delay_sec = reconnect_delay_sec;
+ clt->max_reconnect_attempts = max_reconnect_attempts;
+ clt->priv = priv;
+ clt->link_ev = link_ev;
+ clt->mp_policy = MP_POLICY_MIN_INFLIGHT;
+ strscpy(clt->sessname, sessname, sizeof(clt->sessname));
+ init_waitqueue_head(&clt->permits_wait);
+ mutex_init(&clt->paths_ev_mutex);
+ mutex_init(&clt->paths_mutex);
+ device_initialize(&clt->dev);
+
+ err = dev_set_name(&clt->dev, "%s", sessname);
+ if (err)
+ goto err_put;
+
+ /*
+ * Suppress user space notification until
+ * sysfs files are created
+ */
+ dev_set_uevent_suppress(&clt->dev, true);
+ err = device_add(&clt->dev);
+ if (err)
+ goto err_put;
+
+ clt->kobj_paths = kobject_create_and_add("paths", &clt->dev.kobj);
+ if (!clt->kobj_paths) {
+ err = -ENOMEM;
+ goto err_del;
+ }
+ err = rtrs_clt_create_sysfs_root_files(clt);
+ if (err) {
+ kobject_del(clt->kobj_paths);
+ kobject_put(clt->kobj_paths);
+ goto err_del;
+ }
+ dev_set_uevent_suppress(&clt->dev, false);
+ kobject_uevent(&clt->dev.kobj, KOBJ_ADD);
+
+ return clt;
+err_del:
+ device_del(&clt->dev);
+err_put:
+ free_percpu(clt->pcpu_path);
+ put_device(&clt->dev);
+ return ERR_PTR(err);
+}
+
+static void free_clt(struct rtrs_clt_sess *clt)
+{
+ free_percpu(clt->pcpu_path);
+
+ /*
+ * release callback will free clt and destroy mutexes in last put
+ */
+ device_unregister(&clt->dev);
+}
+
+/**
+ * rtrs_clt_open() - Open a path to an RTRS server
+ * @ops: holds the link event callback and the private pointer.
+ * @pathname: name of the path to an RTRS server
+ * @paths: Paths to be established defined by their src and dst addresses
+ * @paths_num: Number of elements in the @paths array
+ * @port: port to be used by the RTRS session
+ * @pdu_sz: Size of extra payload which can be accessed after permit allocation.
+ * @reconnect_delay_sec: time between reconnect tries
+ * @max_reconnect_attempts: Number of times to reconnect on error before giving
+ * up, 0 for * disabled, -1 for forever
+ * @nr_poll_queues: number of polling mode connection using IB_POLL_DIRECT flag
+ *
+ * Starts session establishment with the rtrs_server. The function can block
+ * up to ~2000ms before it returns.
+ *
+ * Return a valid pointer on success otherwise PTR_ERR.
+ */
+struct rtrs_clt_sess *rtrs_clt_open(struct rtrs_clt_ops *ops,
+ const char *pathname,
+ const struct rtrs_addr *paths,
+ size_t paths_num, u16 port,
+ size_t pdu_sz, u8 reconnect_delay_sec,
+ s16 max_reconnect_attempts, u32 nr_poll_queues)
+{
+ struct rtrs_clt_path *clt_path, *tmp;
+ struct rtrs_clt_sess *clt;
+ int err, i;
+
+ if (strchr(pathname, '/') || strchr(pathname, '.')) {
+ pr_err("pathname cannot contain / and .\n");
+ err = -EINVAL;
+ goto out;
+ }
+
+ clt = alloc_clt(pathname, paths_num, port, pdu_sz, ops->priv,
+ ops->link_ev,
+ reconnect_delay_sec,
+ max_reconnect_attempts);
+ if (IS_ERR(clt)) {
+ err = PTR_ERR(clt);
+ goto out;
+ }
+ for (i = 0; i < paths_num; i++) {
+ struct rtrs_clt_path *clt_path;
+
+ clt_path = alloc_path(clt, &paths[i], nr_cpu_ids,
+ nr_poll_queues);
+ if (IS_ERR(clt_path)) {
+ err = PTR_ERR(clt_path);
+ goto close_all_path;
+ }
+ if (!i)
+ clt_path->for_new_clt = 1;
+ list_add_tail_rcu(&clt_path->s.entry, &clt->paths_list);
+
+ err = init_path(clt_path);
+ if (err) {
+ list_del_rcu(&clt_path->s.entry);
+ rtrs_clt_close_conns(clt_path, true);
+ free_percpu(clt_path->stats->pcpu_stats);
+ kfree(clt_path->stats);
+ free_path(clt_path);
+ goto close_all_path;
+ }
+
+ err = rtrs_clt_create_path_files(clt_path);
+ if (err) {
+ list_del_rcu(&clt_path->s.entry);
+ rtrs_clt_close_conns(clt_path, true);
+ free_percpu(clt_path->stats->pcpu_stats);
+ kfree(clt_path->stats);
+ free_path(clt_path);
+ goto close_all_path;
+ }
+ }
+ err = alloc_permits(clt);
+ if (err)
+ goto close_all_path;
+
+ return clt;
+
+close_all_path:
+ list_for_each_entry_safe(clt_path, tmp, &clt->paths_list, s.entry) {
+ rtrs_clt_destroy_path_files(clt_path, NULL);
+ rtrs_clt_close_conns(clt_path, true);
+ kobject_put(&clt_path->kobj);
+ }
+ rtrs_clt_destroy_sysfs_root(clt);
+ free_clt(clt);
+
+out:
+ return ERR_PTR(err);
+}
+EXPORT_SYMBOL(rtrs_clt_open);
+
+/**
+ * rtrs_clt_close() - Close a path
+ * @clt: Session handle. Session is freed upon return.
+ */
+void rtrs_clt_close(struct rtrs_clt_sess *clt)
+{
+ struct rtrs_clt_path *clt_path, *tmp;
+
+ /* Firstly forbid sysfs access */
+ rtrs_clt_destroy_sysfs_root(clt);
+
+ /* Now it is safe to iterate over all paths without locks */
+ list_for_each_entry_safe(clt_path, tmp, &clt->paths_list, s.entry) {
+ rtrs_clt_close_conns(clt_path, true);
+ rtrs_clt_destroy_path_files(clt_path, NULL);
+ kobject_put(&clt_path->kobj);
+ }
+ free_permits(clt);
+ free_clt(clt);
+}
+EXPORT_SYMBOL(rtrs_clt_close);
+
+int rtrs_clt_reconnect_from_sysfs(struct rtrs_clt_path *clt_path)
+{
+ enum rtrs_clt_state old_state;
+ int err = -EBUSY;
+ bool changed;
+
+ changed = rtrs_clt_change_state_get_old(clt_path,
+ RTRS_CLT_RECONNECTING,
+ &old_state);
+ if (changed) {
+ clt_path->reconnect_attempts = 0;
+ rtrs_clt_stop_and_destroy_conns(clt_path);
+ queue_delayed_work(rtrs_wq, &clt_path->reconnect_dwork, 0);
+ }
+ if (changed || old_state == RTRS_CLT_RECONNECTING) {
+ /*
+ * flush_delayed_work() queues pending work for immediate
+ * execution, so do the flush if we have queued something
+ * right now or work is pending.
+ */
+ flush_delayed_work(&clt_path->reconnect_dwork);
+ err = (READ_ONCE(clt_path->state) ==
+ RTRS_CLT_CONNECTED ? 0 : -ENOTCONN);
+ }
+
+ return err;
+}
+
+int rtrs_clt_remove_path_from_sysfs(struct rtrs_clt_path *clt_path,
+ const struct attribute *sysfs_self)
+{
+ enum rtrs_clt_state old_state;
+ bool changed;
+
+ /*
+ * Continue stopping path till state was changed to DEAD or
+ * state was observed as DEAD:
+ * 1. State was changed to DEAD - we were fast and nobody
+ * invoked rtrs_clt_reconnect(), which can again start
+ * reconnecting.
+ * 2. State was observed as DEAD - we have someone in parallel
+ * removing the path.
+ */
+ do {
+ rtrs_clt_close_conns(clt_path, true);
+ changed = rtrs_clt_change_state_get_old(clt_path,
+ RTRS_CLT_DEAD,
+ &old_state);
+ } while (!changed && old_state != RTRS_CLT_DEAD);
+
+ if (changed) {
+ rtrs_clt_remove_path_from_arr(clt_path);
+ rtrs_clt_destroy_path_files(clt_path, sysfs_self);
+ kobject_put(&clt_path->kobj);
+ }
+
+ return 0;
+}
+
+void rtrs_clt_set_max_reconnect_attempts(struct rtrs_clt_sess *clt, int value)
+{
+ clt->max_reconnect_attempts = (unsigned int)value;
+}
+
+int rtrs_clt_get_max_reconnect_attempts(const struct rtrs_clt_sess *clt)
+{
+ return (int)clt->max_reconnect_attempts;
+}
+
+/**
+ * rtrs_clt_request() - Request data transfer to/from server via RDMA.
+ *
+ * @dir: READ/WRITE
+ * @ops: callback function to be called as confirmation, and the pointer.
+ * @clt: Session
+ * @permit: Preallocated permit
+ * @vec: Message that is sent to server together with the request.
+ * Sum of len of all @vec elements limited to <= IO_MSG_SIZE.
+ * Since the msg is copied internally it can be allocated on stack.
+ * @nr: Number of elements in @vec.
+ * @data_len: length of data sent to/from server
+ * @sg: Pages to be sent/received to/from server.
+ * @sg_cnt: Number of elements in the @sg
+ *
+ * Return:
+ * 0: Success
+ * <0: Error
+ *
+ * On dir=READ rtrs client will request a data transfer from Server to client.
+ * The data that the server will respond with will be stored in @sg when
+ * the user receives an %RTRS_CLT_RDMA_EV_RDMA_REQUEST_WRITE_COMPL event.
+ * On dir=WRITE rtrs client will rdma write data in sg to server side.
+ */
+int rtrs_clt_request(int dir, struct rtrs_clt_req_ops *ops,
+ struct rtrs_clt_sess *clt, struct rtrs_permit *permit,
+ const struct kvec *vec, size_t nr, size_t data_len,
+ struct scatterlist *sg, unsigned int sg_cnt)
+{
+ struct rtrs_clt_io_req *req;
+ struct rtrs_clt_path *clt_path;
+
+ enum dma_data_direction dma_dir;
+ int err = -ECONNABORTED, i;
+ size_t usr_len, hdr_len;
+ struct path_it it;
+
+ /* Get kvec length */
+ for (i = 0, usr_len = 0; i < nr; i++)
+ usr_len += vec[i].iov_len;
+
+ if (dir == READ) {
+ hdr_len = sizeof(struct rtrs_msg_rdma_read) +
+ sg_cnt * sizeof(struct rtrs_sg_desc);
+ dma_dir = DMA_FROM_DEVICE;
+ } else {
+ hdr_len = sizeof(struct rtrs_msg_rdma_write);
+ dma_dir = DMA_TO_DEVICE;
+ }
+
+ rcu_read_lock();
+ for (path_it_init(&it, clt);
+ (clt_path = it.next_path(&it)) && it.i < it.clt->paths_num; it.i++) {
+ if (READ_ONCE(clt_path->state) != RTRS_CLT_CONNECTED)
+ continue;
+
+ if (usr_len + hdr_len > clt_path->max_hdr_size) {
+ rtrs_wrn_rl(clt_path->clt,
+ "%s request failed, user message size is %zu and header length %zu, but max size is %u\n",
+ dir == READ ? "Read" : "Write",
+ usr_len, hdr_len, clt_path->max_hdr_size);
+ err = -EMSGSIZE;
+ break;
+ }
+ req = rtrs_clt_get_req(clt_path, ops->conf_fn, permit, ops->priv,
+ vec, usr_len, sg, sg_cnt, data_len,
+ dma_dir);
+ if (dir == READ)
+ err = rtrs_clt_read_req(req);
+ else
+ err = rtrs_clt_write_req(req);
+ if (err) {
+ req->in_use = false;
+ continue;
+ }
+ /* Success path */
+ break;
+ }
+ path_it_deinit(&it);
+ rcu_read_unlock();
+
+ return err;
+}
+EXPORT_SYMBOL(rtrs_clt_request);
+
+int rtrs_clt_rdma_cq_direct(struct rtrs_clt_sess *clt, unsigned int index)
+{
+ /* If no path, return -1 for block layer not to try again */
+ int cnt = -1;
+ struct rtrs_con *con;
+ struct rtrs_clt_path *clt_path;
+ struct path_it it;
+
+ rcu_read_lock();
+ for (path_it_init(&it, clt);
+ (clt_path = it.next_path(&it)) && it.i < it.clt->paths_num; it.i++) {
+ if (READ_ONCE(clt_path->state) != RTRS_CLT_CONNECTED)
+ continue;
+
+ con = clt_path->s.con[index + 1];
+ cnt = ib_process_cq_direct(con->cq, -1);
+ if (cnt)
+ break;
+ }
+ path_it_deinit(&it);
+ rcu_read_unlock();
+
+ return cnt;
+}
+EXPORT_SYMBOL(rtrs_clt_rdma_cq_direct);
+
+/**
+ * rtrs_clt_query() - queries RTRS session attributes
+ *@clt: session pointer
+ *@attr: query results for session attributes.
+ * Returns:
+ * 0 on success
+ * -ECOMM no connection to the server
+ */
+int rtrs_clt_query(struct rtrs_clt_sess *clt, struct rtrs_attrs *attr)
+{
+ if (!rtrs_clt_is_connected(clt))
+ return -ECOMM;
+
+ attr->queue_depth = clt->queue_depth;
+ attr->max_segments = clt->max_segments;
+ /* Cap max_io_size to min of remote buffer size and the fr pages */
+ attr->max_io_size = min_t(int, clt->max_io_size,
+ clt->max_segments * SZ_4K);
+
+ return 0;
+}
+EXPORT_SYMBOL(rtrs_clt_query);
+
+int rtrs_clt_create_path_from_sysfs(struct rtrs_clt_sess *clt,
+ struct rtrs_addr *addr)
+{
+ struct rtrs_clt_path *clt_path;
+ int err;
+
+ clt_path = alloc_path(clt, addr, nr_cpu_ids, 0);
+ if (IS_ERR(clt_path))
+ return PTR_ERR(clt_path);
+
+ mutex_lock(&clt->paths_mutex);
+ if (clt->paths_num == 0) {
+ /*
+ * When all the paths are removed for a session,
+ * the addition of the first path is like a new session for
+ * the storage server
+ */
+ clt_path->for_new_clt = 1;
+ }
+
+ mutex_unlock(&clt->paths_mutex);
+
+ /*
+ * It is totally safe to add path in CONNECTING state: coming
+ * IO will never grab it. Also it is very important to add
+ * path before init, since init fires LINK_CONNECTED event.
+ */
+ rtrs_clt_add_path_to_arr(clt_path);
+
+ err = init_path(clt_path);
+ if (err)
+ goto close_path;
+
+ err = rtrs_clt_create_path_files(clt_path);
+ if (err)
+ goto close_path;
+
+ return 0;
+
+close_path:
+ rtrs_clt_remove_path_from_arr(clt_path);
+ rtrs_clt_close_conns(clt_path, true);
+ free_percpu(clt_path->stats->pcpu_stats);
+ kfree(clt_path->stats);
+ free_path(clt_path);
+
+ return err;
+}
+
+static int rtrs_clt_ib_dev_init(struct rtrs_ib_dev *dev)
+{
+ if (!(dev->ib_dev->attrs.device_cap_flags &
+ IB_DEVICE_MEM_MGT_EXTENSIONS)) {
+ pr_err("Memory registrations not supported.\n");
+ return -ENOTSUPP;
+ }
+
+ return 0;
+}
+
+static const struct rtrs_rdma_dev_pd_ops dev_pd_ops = {
+ .init = rtrs_clt_ib_dev_init
+};
+
+static int __init rtrs_client_init(void)
+{
+ rtrs_rdma_dev_pd_init(0, &dev_pd);
+
+ rtrs_clt_dev_class = class_create(THIS_MODULE, "rtrs-client");
+ if (IS_ERR(rtrs_clt_dev_class)) {
+ pr_err("Failed to create rtrs-client dev class\n");
+ return PTR_ERR(rtrs_clt_dev_class);
+ }
+ rtrs_wq = alloc_workqueue("rtrs_client_wq", 0, 0);
+ if (!rtrs_wq) {
+ class_destroy(rtrs_clt_dev_class);
+ return -ENOMEM;
+ }
+
+ return 0;
+}
+
+static void __exit rtrs_client_exit(void)
+{
+ destroy_workqueue(rtrs_wq);
+ class_destroy(rtrs_clt_dev_class);
+ rtrs_rdma_dev_pd_deinit(&dev_pd);
+}
+
+module_init(rtrs_client_init);
+module_exit(rtrs_client_exit);