| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Jack Wang | 12275 | 86.95% | 26 | 33.33% |
| Vaishali Thakkar | 695 | 4.92% | 3 | 3.85% |
| Gioh Kim | 483 | 3.42% | 12 | 15.38% |
| Md Haris Iqbal | 283 | 2.00% | 10 | 12.82% |
| Danil Kipnis | 128 | 0.91% | 2 | 2.56% |
| Xiao Jiang | 86 | 0.61% | 8 | 10.26% |
| Li Zhijian | 57 | 0.40% | 1 | 1.28% |
| Ivan Orlov | 24 | 0.17% | 1 | 1.28% |
| Guoqing Jiang | 23 | 0.16% | 3 | 3.85% |
| Santosh kumar pradhan | 18 | 0.13% | 1 | 1.28% |
| Supriti Singh | 17 | 0.12% | 1 | 1.28% |
| Zhu Yanjun | 11 | 0.08% | 1 | 1.28% |
| Christophe Jaillet | 7 | 0.05% | 2 | 2.56% |
| Jason A. Donenfeld | 3 | 0.02% | 2 | 2.56% |
| Dima Stepanov | 2 | 0.01% | 1 | 1.28% |
| Jason Gunthorpe | 2 | 0.01% | 1 | 1.28% |
| Li Yang | 1 | 0.01% | 1 | 1.28% |
| Al Viro | 1 | 0.01% | 1 | 1.28% |
| Leon Romanovsky | 1 | 0.01% | 1 | 1.28% |
| Total | 14117 | 78 |
// 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 const struct class rtrs_clt_dev_class = { .name = "rtrs-client", }; 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 held. */ 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; /* * Assert that rcu lock must be held */ RCU_LOCKDEP_WARN(!rcu_read_lock_held(), "no rcu read lock held"); 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 != count) return nr < 0 ? nr : -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); pr_err("Failed to alloc clt_path->max_pages_per_mr %d: %pe\n", clt_path->max_pages_per_mr, req->mr); req->mr = NULL; 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 + get_random_u32_below(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_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, ¶m); 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_wrn_rl(s, "CM event: %s, status: %d\n", rdma_event_msg(ev->event), ev->status); 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)) { rtrs_err(s, "Failed to create CM ID, err: %pe\n", cm_id); return PTR_ERR(cm_id); } 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) { int ret = 0; rtrs_rdma_dev_pd_init(0, &dev_pd); ret = class_register(&rtrs_clt_dev_class); if (ret) { pr_err("Failed to create rtrs-client dev class\n"); return ret; } rtrs_wq = alloc_workqueue("rtrs_client_wq", 0, 0); if (!rtrs_wq) { class_unregister(&rtrs_clt_dev_class); return -ENOMEM; } return 0; } static void __exit rtrs_client_exit(void) { destroy_workqueue(rtrs_wq); class_unregister(&rtrs_clt_dev_class); rtrs_rdma_dev_pd_deinit(&dev_pd); } module_init(rtrs_client_init); module_exit(rtrs_client_exit);
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