This is main functionality of ibtrs-client module, which manages set of RDMA connections for each IBTRS session, does multipathing, load balancing and failover of RDMA requests. Signed-off-by: Roman Pen <roman.penyaev@xxxxxxxxxxxxxxxx> Signed-off-by: Danil Kipnis <danil.kipnis@xxxxxxxxxxxxxxxx> Cc: Jack Wang <jinpu.wang@xxxxxxxxxxxxxxxx> --- drivers/infiniband/ulp/ibtrs/ibtrs-clt.c | 2844 ++++++++++++++++++++++++++++++ 1 file changed, 2844 insertions(+) create mode 100644 drivers/infiniband/ulp/ibtrs/ibtrs-clt.c diff --git a/drivers/infiniband/ulp/ibtrs/ibtrs-clt.c b/drivers/infiniband/ulp/ibtrs/ibtrs-clt.c new file mode 100644 index 000000000000..dc0327a95ef6 --- /dev/null +++ b/drivers/infiniband/ulp/ibtrs/ibtrs-clt.c @@ -0,0 +1,2844 @@ +/* + * InfiniBand Transport Layer + * + * Copyright (c) 2014 - 2017 ProfitBricks GmbH. All rights reserved. + * Authors: Fabian Holler <mail@xxxxxxxxxx> + * Jack Wang <jinpu.wang@xxxxxxxxxxxxxxxx> + * Kleber Souza <kleber.souza@xxxxxxxxxxxxxxxx> + * Danil Kipnis <danil.kipnis@xxxxxxxxxxxxxxxx> + * Roman Penyaev <roman.penyaev@xxxxxxxxxxxxxxxx> + * Milind Dumbare <Milind.dumbare@xxxxxxxxx> + * + * Copyright (c) 2017 - 2018 ProfitBricks GmbH. All rights reserved. + * Authors: Danil Kipnis <danil.kipnis@xxxxxxxxxxxxxxxx> + * Roman Penyaev <roman.penyaev@xxxxxxxxxxxxxxxx> + * Swapnil Ingle <swapnil.ingle@xxxxxxxxxxxxxxxx> + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version 2 + * of the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, see <http://www.gnu.org/licenses/>. + */ + +#undef pr_fmt +#define pr_fmt(fmt) KBUILD_MODNAME " L" __stringify(__LINE__) ": " fmt + +#include <linux/module.h> +#include <linux/rculist.h> + +#include "ibtrs-clt.h" +#include "ibtrs-log.h" + +#define MAX_SEGMENTS 31 +#define IBTRS_CONNECT_TIMEOUT_MS 5000 + +MODULE_AUTHOR("ibnbd@xxxxxxxxxxxxxxxx"); +MODULE_DESCRIPTION("IBTRS Client"); +MODULE_VERSION(IBTRS_VER_STRING); +MODULE_LICENSE("GPL"); + +static ushort nr_cons_per_session; +module_param(nr_cons_per_session, ushort, 0444); +MODULE_PARM_DESC(nr_cons_per_session, "Number of connections per session." + " (default: nr_cpu_ids)"); + +static int retry_cnt = 7; +module_param_named(retry_cnt, retry_cnt, int, 0644); +MODULE_PARM_DESC(retry_cnt, "Number of times to send the message if the" + " remote side didn't respond with Ack or Nack (default: 7," + " min: " __stringify(MIN_RTR_CNT) ", max: " + __stringify(MAX_RTR_CNT) ")"); + +static int __read_mostly noreg_cnt = 0; +module_param_named(noreg_cnt, noreg_cnt, int, 0444); +MODULE_PARM_DESC(noreg_cnt, "Max number of SG entries when MR registration " + "does not happen (default: 0)"); + +static const struct ibtrs_ib_dev_pool_ops dev_pool_ops; +static struct ibtrs_ib_dev_pool dev_pool = { + .ops = &dev_pool_ops +}; +static struct workqueue_struct *ibtrs_wq; +static struct class *ibtrs_dev_class; + +static void ibtrs_rdma_error_recovery(struct ibtrs_clt_con *con); +static int ibtrs_clt_rdma_cm_handler(struct rdma_cm_id *cm_id, + struct rdma_cm_event *ev); +static void ibtrs_clt_rdma_done(struct ib_cq *cq, struct ib_wc *wc); +static void complete_rdma_req(struct ibtrs_clt_io_req *req, int errno, + bool notify, bool can_wait); +static int ibtrs_clt_write_req(struct ibtrs_clt_io_req *req); +static int ibtrs_clt_read_req(struct ibtrs_clt_io_req *req); + +bool ibtrs_clt_sess_is_connected(const struct ibtrs_clt_sess *sess) +{ + return sess->state == IBTRS_CLT_CONNECTED; +} + +static inline bool ibtrs_clt_is_connected(const struct ibtrs_clt *clt) +{ + struct ibtrs_clt_sess *sess; + bool connected = false; + + rcu_read_lock(); + list_for_each_entry_rcu(sess, &clt->paths_list, s.entry) + connected |= ibtrs_clt_sess_is_connected(sess); + rcu_read_unlock(); + + return connected; +} + +static inline struct ibtrs_tag * +__ibtrs_get_tag(struct ibtrs_clt *clt, enum ibtrs_clt_con_type con_type) +{ + size_t max_depth = clt->queue_depth; + struct ibtrs_tag *tag; + int cpu, bit; + + cpu = get_cpu(); + do { + bit = find_first_zero_bit(clt->tags_map, max_depth); + if (unlikely(bit >= max_depth)) { + put_cpu(); + return NULL; + } + + } while (unlikely(test_and_set_bit_lock(bit, clt->tags_map))); + put_cpu(); + + tag = GET_TAG(clt, bit); + WARN_ON(tag->mem_id != bit); + tag->cpu_id = cpu; + tag->con_type = con_type; + + return tag; +} + +static inline void __ibtrs_put_tag(struct ibtrs_clt *clt, + struct ibtrs_tag *tag) +{ + clear_bit_unlock(tag->mem_id, clt->tags_map); +} + +struct ibtrs_tag *ibtrs_clt_get_tag(struct ibtrs_clt *clt, + enum ibtrs_clt_con_type con_type, + int can_wait) +{ + struct ibtrs_tag *tag; + DEFINE_WAIT(wait); + + tag = __ibtrs_get_tag(clt, con_type); + if (likely(tag) || !can_wait) + return tag; + + do { + prepare_to_wait(&clt->tags_wait, &wait, TASK_UNINTERRUPTIBLE); + tag = __ibtrs_get_tag(clt, con_type); + if (likely(tag)) + break; + + io_schedule(); + } while (1); + + finish_wait(&clt->tags_wait, &wait); + + return tag; +} +EXPORT_SYMBOL(ibtrs_clt_get_tag); + +void ibtrs_clt_put_tag(struct ibtrs_clt *clt, struct ibtrs_tag *tag) +{ + if (WARN_ON(!test_bit(tag->mem_id, clt->tags_map))) + return; + + __ibtrs_put_tag(clt, tag); + + /* + * Putting a tag is a barrier, so we will observe + * new entry in the wait list, no worries. + */ + if (waitqueue_active(&clt->tags_wait)) + wake_up(&clt->tags_wait); +} +EXPORT_SYMBOL(ibtrs_clt_put_tag); + +struct ibtrs_tag *ibtrs_tag_from_pdu(void *pdu) +{ + return pdu - sizeof(struct ibtrs_tag); +} +EXPORT_SYMBOL(ibtrs_tag_from_pdu); + +void *ibtrs_tag_to_pdu(struct ibtrs_tag *tag) +{ + return tag + 1; +} +EXPORT_SYMBOL(ibtrs_tag_to_pdu); + +/** + * ibtrs_tag_to_clt_con() - returns RDMA connection id by the tag + * + * Note: + * IO connection starts from 1. + * 0 connection is for user messages. + */ +static struct ibtrs_clt_con *ibtrs_tag_to_clt_con(struct ibtrs_clt_sess *sess, + struct ibtrs_tag *tag) +{ + int id = 0; + + if (likely(tag->con_type == IBTRS_IO_CON)) + id = (tag->cpu_id % (sess->s.con_num - 1)) + 1; + + return to_clt_con(sess->s.con[id]); +} + +static void ibtrs_clt_fast_reg_done(struct ib_cq *cq, struct ib_wc *wc) +{ + struct ibtrs_clt_con *con = cq->cq_context; + struct ibtrs_clt_sess *sess = to_clt_sess(con->c.sess); + + if (unlikely(wc->status != IB_WC_SUCCESS)) { + ibtrs_err(sess, "Failed IB_WR_REG_MR: %s\n", + ib_wc_status_msg(wc->status)); + ibtrs_rdma_error_recovery(con); + } +} + +static struct ib_cqe fast_reg_cqe = { + .done = ibtrs_clt_fast_reg_done +}; + +static void ibtrs_clt_inv_rkey_done(struct ib_cq *cq, struct ib_wc *wc) +{ + struct ibtrs_clt_io_req *req = + container_of(wc->wr_cqe, typeof(*req), inv_cqe); + struct ibtrs_clt_con *con = cq->cq_context; + struct ibtrs_clt_sess *sess = to_clt_sess(con->c.sess); + + if (unlikely(wc->status != IB_WC_SUCCESS)) { + ibtrs_err(sess, "Failed IB_WR_LOCAL_INV: %s\n", + ib_wc_status_msg(wc->status)); + ibtrs_rdma_error_recovery(con); + } + req->need_inv = false; + if (likely(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 ibtrs_inv_rkey(struct ibtrs_clt_io_req *req) +{ + struct ibtrs_clt_con *con = req->con; + struct ib_send_wr *bad_wr; + struct ib_send_wr wr = { + .opcode = IB_WR_LOCAL_INV, + .wr_cqe = &req->inv_cqe, + .next = NULL, + .num_sge = 0, + .send_flags = IB_SEND_SIGNALED, + .ex.invalidate_rkey = req->mr->rkey, + }; + req->inv_cqe.done = ibtrs_clt_inv_rkey_done; + + return ib_post_send(con->c.qp, &wr, &bad_wr); +} + +static int ibtrs_post_send_rdma(struct ibtrs_clt_con *con, + struct ibtrs_clt_io_req *req, + struct ibtrs_rbuf *rbuf, u32 off, + u32 imm, struct ib_send_wr *wr) +{ + struct ibtrs_clt_sess *sess = to_clt_sess(con->c.sess); + enum ib_send_flags flags; + struct ib_sge sge; + + if (unlikely(!req->sg_size)) { + ibtrs_wrn(sess, "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 = sess->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->io_cnt) % sess->queue_depth ? + 0 : IB_SEND_SIGNALED; + + ib_dma_sync_single_for_device(sess->s.dev->ib_dev, req->iu->dma_addr, + req->sg_size, DMA_TO_DEVICE); + + return ibtrs_iu_post_rdma_write_imm(&con->c, req->iu, &sge, 1, + rbuf->rkey, rbuf->addr + off, + imm, flags, wr); +} + +static void complete_rdma_req(struct ibtrs_clt_io_req *req, int errno, + bool notify, bool can_wait) +{ + struct ibtrs_clt_con *con = req->con; + struct ibtrs_clt_sess *sess; + struct ibtrs_clt *clt; + int err; + + if (WARN_ON(!req->in_use)) + return; + if (WARN_ON(!req->con)) + return; + sess = to_clt_sess(con->c.sess); + clt = sess->clt; + + if (req->sg_cnt) { + if (unlikely(req->dir == DMA_FROM_DEVICE && req->need_inv)) { + /* + * We are here to invalidate RDMA read requests + * ourselves. In normal scenario server should + * send INV for all requested RDMA reads, 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 (likely(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; + } + + err = ibtrs_inv_rkey(req); + if (unlikely(err)) + ibtrs_err(sess, "Send INV WR key=%#x: %d\n", + req->mr->rkey, err); + else if (likely(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; + } + } + ib_dma_unmap_sg(sess->s.dev->ib_dev, req->sglist, + req->sg_cnt, req->dir); + } + if (sess->stats.enable_rdma_lat) + ibtrs_clt_update_rdma_lat(&sess->stats, + req->dir == DMA_FROM_DEVICE, + jiffies_to_msecs(jiffies - req->start_jiffies)); + ibtrs_clt_decrease_inflight(&sess->stats); + + req->in_use = false; + req->con = NULL; + + if (notify) + req->conf(req->priv, errno); +} + +static void process_io_rsp(struct ibtrs_clt_sess *sess, u32 msg_id, + s16 errno, bool w_inval) +{ + struct ibtrs_clt_io_req *req; + + if (WARN_ON(msg_id >= sess->queue_depth)) + return; + + req = &sess->reqs[msg_id]; + /* Drop need_inv if server responsed with invalidation */ + req->need_inv &= !w_inval; + complete_rdma_req(req, errno, true, false); +} + +static struct ib_cqe io_comp_cqe = { + .done = ibtrs_clt_rdma_done +}; + +static void ibtrs_clt_rdma_done(struct ib_cq *cq, struct ib_wc *wc) +{ + struct ibtrs_clt_con *con = cq->cq_context; + struct ibtrs_clt_sess *sess = to_clt_sess(con->c.sess); + u32 imm_type, imm_payload; + bool w_inval = false; + int err; + + if (unlikely(wc->status != IB_WC_SUCCESS)) { + if (wc->status != IB_WC_WR_FLUSH_ERR) { + ibtrs_err(sess, "RDMA failed: %s\n", + ib_wc_status_msg(wc->status)); + ibtrs_rdma_error_recovery(con); + } + return; + } + ibtrs_clt_update_wc_stats(con); + + switch (wc->opcode) { + case IB_WC_RDMA_WRITE: + /* + * post_send() RDMA write completions of IO reqs (read/write) + * and hb + */ + break; + case IB_WC_RECV: + /* + * Key invalidations from server side + */ + WARN_ON(!(wc->wc_flags & IB_WC_WITH_INVALIDATE)); + WARN_ON(wc->wr_cqe != &io_comp_cqe); + break; + + 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 != &io_comp_cqe)) + return; + + ibtrs_from_imm(be32_to_cpu(wc->ex.imm_data), + &imm_type, &imm_payload); + if (likely(imm_type == IBTRS_IO_RSP_IMM || + imm_type == IBTRS_IO_RSP_W_INV_IMM)) { + u32 msg_id; + + w_inval = (imm_type == IBTRS_IO_RSP_W_INV_IMM); + ibtrs_from_io_rsp_imm(imm_payload, &msg_id, &err); + process_io_rsp(sess, msg_id, err, w_inval); + } else if (imm_type == IBTRS_HB_MSG_IMM) { + WARN_ON(con->c.cid); + ibtrs_send_hb_ack(&sess->s); + } else if (imm_type == IBTRS_HB_ACK_IMM) { + WARN_ON(con->c.cid); + sess->s.hb_missed_cnt = 0; + } else { + ibtrs_wrn(sess, "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 = ibtrs_post_recv_empty_x2(&con->c, &io_comp_cqe); + else + err = ibtrs_post_recv_empty(&con->c, &io_comp_cqe); + if (unlikely(err)) { + ibtrs_err(sess, "ibtrs_post_recv_empty(): %d\n", err); + ibtrs_rdma_error_recovery(con); + break; + } + break; + default: + ibtrs_wrn(sess, "Unexpected WC type: %d\n", wc->opcode); + return; + } +} + +static int post_recv_io(struct ibtrs_clt_con *con, size_t q_size) +{ + int err, i; + + for (i = 0; i < q_size; i++) { + err = ibtrs_post_recv_empty(&con->c, &io_comp_cqe); + if (unlikely(err)) + return err; + } + + return 0; +} + +static int post_recv_sess(struct ibtrs_clt_sess *sess) +{ + size_t q_size; + int err, cid; + + for (cid = 0; cid < sess->s.con_num; cid++) { + if (cid == 0) + q_size = SERVICE_CON_QUEUE_DEPTH; + else + q_size = sess->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(sess->s.con[cid]), q_size); + if (unlikely(err)) { + ibtrs_err(sess, "post_recv_io(), err: %d\n", err); + return err; + } + } + + return 0; +} + +struct path_it { + int i; + struct list_head skip_list; + struct ibtrs_clt *clt; + struct ibtrs_clt_sess *(*next_path)(struct path_it *); +}; + +#define do_each_path(path, clt, it) { \ + path_it_init(it, clt); \ + rcu_read_lock(); \ + for ((it)->i = 0; ((path) = ((it)->next_path)(it)) && \ + (it)->i < (it)->clt->paths_num; \ + (it)->i++) + +#define while_each_path(it) \ + path_it_deinit(it); \ + rcu_read_unlock(); \ + } + +/** + * list_next_or_null_rr_rcu - get next list element in round-robin fashion. + * @head: the head for the list. + * @ptr: the list head to take the next element from. + * @type: the type of the struct this is embedded in. + * @memb: the name of the list_head within the struct. + * + * Next element returned in round-robin fashion, i.e. head will be skipped, + * but if list is observed as empty, NULL will be returned. + * + * This primitive 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(). + */ +#define list_next_or_null_rr_rcu(head, ptr, type, memb) \ +({ \ + list_next_or_null_rcu(head, ptr, type, memb) ?: \ + list_next_or_null_rcu(head, READ_ONCE((ptr)->next), type, memb); \ +}) + +/** + * get_next_path_rr() - Returns path in round-robin fashion. + * + * Related to @MP_POLICY_RR + * + * Locks: + * rcu_read_lock() must be hold. + */ +static struct ibtrs_clt_sess *get_next_path_rr(struct path_it *it) +{ + struct ibtrs_clt_sess __rcu **ppcpu_path; + struct ibtrs_clt_sess *path; + struct ibtrs_clt *clt; + + clt = it->clt; + + /* + * Here we use two RCU objects: @paths_list and @pcpu_path + * pointer. See ibtrs_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 (unlikely(!path)) + path = list_first_or_null_rcu(&clt->paths_list, + typeof(*path), s.entry); + else + path = list_next_or_null_rr_rcu(&clt->paths_list, + &path->s.entry, + typeof(*path), + s.entry); + rcu_assign_pointer(*ppcpu_path, path); + + return path; +} + +/** + * get_next_path_min_inflight() - Returns path with minimal inflight count. + * + * Related to @MP_POLICY_MIN_INFLIGHT + * + * Locks: + * rcu_read_lock() must be hold. + */ +static struct ibtrs_clt_sess *get_next_path_min_inflight(struct path_it *it) +{ + struct ibtrs_clt_sess *min_path = NULL; + struct ibtrs_clt *clt = it->clt; + struct ibtrs_clt_sess *sess; + int min_inflight = INT_MAX; + int inflight; + + list_for_each_entry_rcu(sess, &clt->paths_list, s.entry) { + if (unlikely(!list_empty(raw_cpu_ptr(sess->mp_skip_entry)))) + continue; + + inflight = atomic_read(&sess->stats.inflight); + + if (inflight < min_inflight) { + min_inflight = inflight; + min_path = sess; + } + } + + /* + * 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 ibtrs_clt *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 + it->next_path = get_next_path_min_inflight; +} + +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 policy. + * 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); +} + +static inline void ibtrs_clt_init_req(struct ibtrs_clt_io_req *req, + struct ibtrs_clt_sess *sess, + ibtrs_conf_fn *conf, + struct ibtrs_tag *tag, 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->tag = tag; + 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 = ibtrs_tag_to_clt_con(sess, tag); + req->conf = conf; + req->need_inv = false; + req->need_inv_comp = false; + req->inv_errno = 0; + + iov_iter_kvec(&iter, ITER_KVEC, vec, 1, usr_len); + len = _copy_from_iter(req->iu->buf, usr_len, &iter); + WARN_ON(len != usr_len); + + reinit_completion(&req->inv_comp); + if (sess->stats.enable_rdma_lat) + req->start_jiffies = jiffies; +} + +static inline struct ibtrs_clt_io_req * +ibtrs_clt_get_req(struct ibtrs_clt_sess *sess, ibtrs_conf_fn *conf, + struct ibtrs_tag *tag, void *priv, + const struct kvec *vec, size_t usr_len, + struct scatterlist *sg, size_t sg_cnt, + size_t data_len, int dir) +{ + struct ibtrs_clt_io_req *req; + + req = &sess->reqs[tag->mem_id]; + ibtrs_clt_init_req(req, sess, conf, tag, priv, vec, usr_len, + sg, sg_cnt, data_len, dir); + return req; +} + +static inline struct ibtrs_clt_io_req * +ibtrs_clt_get_copy_req(struct ibtrs_clt_sess *alive_sess, + struct ibtrs_clt_io_req *fail_req) +{ + struct ibtrs_clt_io_req *req; + struct kvec vec = { + .iov_base = fail_req->iu->buf, + .iov_len = fail_req->usr_len + }; + + req = &alive_sess->reqs[fail_req->tag->mem_id]; + ibtrs_clt_init_req(req, alive_sess, fail_req->conf, fail_req->tag, + 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 ibtrs_clt_failover_req(struct ibtrs_clt *clt, + struct ibtrs_clt_io_req *fail_req) +{ + struct ibtrs_clt_sess *alive_sess; + struct ibtrs_clt_io_req *req; + int err = -ECONNABORTED; + struct path_it it; + + do_each_path(alive_sess, clt, &it) { + if (unlikely(alive_sess->state != IBTRS_CLT_CONNECTED)) + continue; + req = ibtrs_clt_get_copy_req(alive_sess, fail_req); + if (req->dir == DMA_TO_DEVICE) + err = ibtrs_clt_write_req(req); + else + err = ibtrs_clt_read_req(req); + if (unlikely(err)) { + req->in_use = false; + continue; + } + /* Success path */ + ibtrs_clt_inc_failover_cnt(&alive_sess->stats); + break; + } while_each_path(&it); + + return err; +} + +static void fail_all_outstanding_reqs(struct ibtrs_clt_sess *sess) +{ + struct ibtrs_clt *clt = sess->clt; + struct ibtrs_clt_io_req *req; + int i, err; + + if (!sess->reqs) + return; + for (i = 0; i < sess->queue_depth; ++i) { + req = &sess->reqs[i]; + if (!req->in_use) + continue; + + /* + * Safely (without notification) complete failed request. + * After completion this request is still usebale and can + * be failovered to another path. + */ + complete_rdma_req(req, -ECONNABORTED, false, true); + + err = ibtrs_clt_failover_req(clt, req); + if (unlikely(err)) + /* Failover failed, notify anyway */ + req->conf(req->priv, err); + } +} + +static void free_sess_reqs(struct ibtrs_clt_sess *sess) +{ + struct ibtrs_clt_io_req *req; + int i; + + if (!sess->reqs) + return; + for (i = 0; i < sess->queue_depth; ++i) { + req = &sess->reqs[i]; + if (req->mr) + ib_dereg_mr(req->mr); + kfree(req->sge); + ibtrs_iu_free(req->iu, DMA_TO_DEVICE, + sess->s.dev->ib_dev); + } + kfree(sess->reqs); + sess->reqs = NULL; +} + +static int alloc_sess_reqs(struct ibtrs_clt_sess *sess) +{ + struct ibtrs_clt_io_req *req; + struct ibtrs_clt *clt = sess->clt; + int i, err = -ENOMEM; + + sess->reqs = kcalloc(sess->queue_depth, sizeof(*sess->reqs), + GFP_KERNEL); + if (unlikely(!sess->reqs)) + return -ENOMEM; + + for (i = 0; i < sess->queue_depth; ++i) { + req = &sess->reqs[i]; + req->iu = ibtrs_iu_alloc(i, sess->max_hdr_size, GFP_KERNEL, + sess->s.dev->ib_dev, DMA_TO_DEVICE, + ibtrs_clt_rdma_done); + if (unlikely(!req->iu)) + goto out; + + req->sge = kmalloc_array(clt->max_segments + 1, + sizeof(*req->sge), GFP_KERNEL); + if (unlikely(!req->sge)) + goto out; + + req->mr = ib_alloc_mr(sess->s.dev->ib_pd, IB_MR_TYPE_MEM_REG, + clt->max_segments + 1); + if (unlikely(IS_ERR(req->mr))) { + err = PTR_ERR(req->mr); + req->mr = NULL; + goto out; + } + + init_completion(&req->inv_comp); + } + + return 0; + +out: + free_sess_reqs(sess); + + return err; +} + +static int alloc_tags(struct ibtrs_clt *clt) +{ + unsigned int chunk_bits; + int err, i; + + clt->tags_map = kcalloc(BITS_TO_LONGS(clt->queue_depth), sizeof(long), + GFP_KERNEL); + if (unlikely(!clt->tags_map)) { + err = -ENOMEM; + goto out_err; + } + clt->tags = kcalloc(clt->queue_depth, TAG_SIZE(clt), GFP_KERNEL); + if (unlikely(!clt->tags)) { + err = -ENOMEM; + goto err_map; + } + chunk_bits = ilog2(clt->queue_depth - 1) + 1; + for (i = 0; i < clt->queue_depth; i++) { + struct ibtrs_tag *tag; + + tag = GET_TAG(clt, i); + tag->mem_id = i; + tag->mem_off = i << (MAX_IMM_PAYL_BITS - chunk_bits); + } + + return 0; + +err_map: + kfree(clt->tags_map); + clt->tags_map = NULL; +out_err: + return err; +} + +static void free_tags(struct ibtrs_clt *clt) +{ + kfree(clt->tags_map); + clt->tags_map = NULL; + kfree(clt->tags); + clt->tags = NULL; +} + +static void query_fast_reg_mode(struct ibtrs_clt_sess *sess) +{ + struct ib_device *ib_dev; + u64 max_pages_per_mr; + int mr_page_shift; + + ib_dev = sess->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)); + sess->max_pages_per_mr = + min3(sess->max_pages_per_mr, (u32)max_pages_per_mr, + ib_dev->attrs.max_fast_reg_page_list_len); + sess->max_sge = ib_dev->attrs.max_sge; +} + +static bool __ibtrs_clt_change_state(struct ibtrs_clt_sess *sess, + enum ibtrs_clt_state new_state) +{ + enum ibtrs_clt_state old_state; + bool changed = false; + + old_state = sess->state; + switch (new_state) { + case IBTRS_CLT_CONNECTING: + switch (old_state) { + case IBTRS_CLT_RECONNECTING: + changed = true; + /* FALLTHRU */ + default: + break; + } + break; + case IBTRS_CLT_RECONNECTING: + switch (old_state) { + case IBTRS_CLT_CONNECTED: + case IBTRS_CLT_CONNECTING_ERR: + case IBTRS_CLT_CLOSED: + changed = true; + /* FALLTHRU */ + default: + break; + } + break; + case IBTRS_CLT_CONNECTED: + switch (old_state) { + case IBTRS_CLT_CONNECTING: + changed = true; + /* FALLTHRU */ + default: + break; + } + break; + case IBTRS_CLT_CONNECTING_ERR: + switch (old_state) { + case IBTRS_CLT_CONNECTING: + changed = true; + /* FALLTHRU */ + default: + break; + } + break; + case IBTRS_CLT_CLOSING: + switch (old_state) { + case IBTRS_CLT_CONNECTING: + case IBTRS_CLT_CONNECTING_ERR: + case IBTRS_CLT_RECONNECTING: + case IBTRS_CLT_CONNECTED: + changed = true; + /* FALLTHRU */ + default: + break; + } + break; + case IBTRS_CLT_CLOSED: + switch (old_state) { + case IBTRS_CLT_CLOSING: + changed = true; + /* FALLTHRU */ + default: + break; + } + break; + case IBTRS_CLT_DEAD: + switch (old_state) { + case IBTRS_CLT_CLOSED: + changed = true; + /* FALLTHRU */ + default: + break; + } + break; + default: + break; + } + if (changed) { + sess->state = new_state; + wake_up_locked(&sess->state_wq); + } + + return changed; +} + +static bool ibtrs_clt_change_state_from_to(struct ibtrs_clt_sess *sess, + enum ibtrs_clt_state old_state, + enum ibtrs_clt_state new_state) +{ + bool changed = false; + + spin_lock_irq(&sess->state_wq.lock); + if (sess->state == old_state) + changed = __ibtrs_clt_change_state(sess, new_state); + spin_unlock_irq(&sess->state_wq.lock); + + return changed; +} + +static bool ibtrs_clt_change_state_get_old(struct ibtrs_clt_sess *sess, + enum ibtrs_clt_state new_state, + enum ibtrs_clt_state *old_state) +{ + bool changed; + + spin_lock_irq(&sess->state_wq.lock); + *old_state = sess->state; + changed = __ibtrs_clt_change_state(sess, new_state); + spin_unlock_irq(&sess->state_wq.lock); + + return changed; +} + +static bool ibtrs_clt_change_state(struct ibtrs_clt_sess *sess, + enum ibtrs_clt_state new_state) +{ + enum ibtrs_clt_state old_state; + + return ibtrs_clt_change_state_get_old(sess, new_state, &old_state); +} + +static enum ibtrs_clt_state ibtrs_clt_state(struct ibtrs_clt_sess *sess) +{ + enum ibtrs_clt_state state; + + spin_lock_irq(&sess->state_wq.lock); + state = sess->state; + spin_unlock_irq(&sess->state_wq.lock); + + return state; +} + +static void ibtrs_clt_hb_err_handler(struct ibtrs_con *c, int err) +{ + struct ibtrs_clt_con *con; + + (void)err; + con = container_of(c, typeof(*con), c); + ibtrs_rdma_error_recovery(con); +} + +static void ibtrs_clt_init_hb(struct ibtrs_clt_sess *sess) +{ + ibtrs_init_hb(&sess->s, &io_comp_cqe, + IBTRS_HB_INTERVAL_MS, + IBTRS_HB_MISSED_MAX, + ibtrs_clt_hb_err_handler, + ibtrs_wq); +} + +static void ibtrs_clt_start_hb(struct ibtrs_clt_sess *sess) +{ + ibtrs_start_hb(&sess->s); +} + +static void ibtrs_clt_stop_hb(struct ibtrs_clt_sess *sess) +{ + ibtrs_stop_hb(&sess->s); +} + +static void ibtrs_clt_reconnect_work(struct work_struct *work); +static void ibtrs_clt_close_work(struct work_struct *work); + +static struct ibtrs_clt_sess *alloc_sess(struct ibtrs_clt *clt, + const struct ibtrs_addr *path, + size_t con_num, u16 max_segments) +{ + struct ibtrs_clt_sess *sess; + int err = -ENOMEM; + int cpu; + + sess = kzalloc(sizeof(*sess), GFP_KERNEL); + if (unlikely(!sess)) + goto err; + + /* Extra connection for user messages */ + con_num += 1; + + sess->s.con = kcalloc(con_num, sizeof(*sess->s.con), GFP_KERNEL); + if (unlikely(!sess->s.con)) + goto err_free_sess; + + mutex_init(&sess->init_mutex); + uuid_gen(&sess->s.uuid); + memcpy(&sess->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(&sess->s.src_addr, path->src, + rdma_addr_size((struct sockaddr *)path->src)); + strlcpy(sess->s.sessname, clt->sessname, sizeof(sess->s.sessname)); + sess->s.con_num = con_num; + sess->clt = clt; + sess->max_pages_per_mr = max_segments; + init_waitqueue_head(&sess->state_wq); + sess->state = IBTRS_CLT_CONNECTING; + atomic_set(&sess->connected_cnt, 0); + INIT_WORK(&sess->close_work, ibtrs_clt_close_work); + INIT_DELAYED_WORK(&sess->reconnect_dwork, ibtrs_clt_reconnect_work); + ibtrs_clt_init_hb(sess); + + sess->mp_skip_entry = alloc_percpu(typeof(*sess->mp_skip_entry)); + if (unlikely(!sess->mp_skip_entry)) + goto err_free_con; + + for_each_possible_cpu(cpu) + INIT_LIST_HEAD(per_cpu_ptr(sess->mp_skip_entry, cpu)); + + err = ibtrs_clt_init_stats(&sess->stats); + if (unlikely(err)) + goto err_free_percpu; + + return sess; + +err_free_percpu: + free_percpu(sess->mp_skip_entry); +err_free_con: + kfree(sess->s.con); +err_free_sess: + kfree(sess); +err: + return ERR_PTR(err); +} + +static void free_sess(struct ibtrs_clt_sess *sess) +{ + ibtrs_clt_free_stats(&sess->stats); + free_percpu(sess->mp_skip_entry); + kfree(sess->s.con); + kfree(sess->rbufs); + kfree(sess); +} + +static int create_con(struct ibtrs_clt_sess *sess, unsigned int cid) +{ + struct ibtrs_clt_con *con; + + con = kzalloc(sizeof(*con), GFP_KERNEL); + if (unlikely(!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.sess = &sess->s; + atomic_set(&con->io_cnt, 0); + + sess->s.con[cid] = &con->c; + + return 0; +} + +static void destroy_con(struct ibtrs_clt_con *con) +{ + struct ibtrs_clt_sess *sess = to_clt_sess(con->c.sess); + + sess->s.con[con->c.cid] = NULL; + kfree(con); +} + +static int create_con_cq_qp(struct ibtrs_clt_con *con) +{ + struct ibtrs_clt_sess *sess = to_clt_sess(con->c.sess); + u16 cq_size, wr_queue_size; + int err, cq_vector; + + /* + * This function can fail, but still destroy_con_cq_qp() should + * be called, this is because create_con_cq_qp() is called on cm + * event path, thus caller/waiter never knows: have we failed before + * create_con_cq_qp() or after. To solve this dilemma without + * creating any additional flags just allow destroy_con_cq_qp() be + * called many times. + */ + + if (con->c.cid == 0) { + /* + * One completion for each receive and two for each send + * (send request + registration) + * + 2 for drain and heartbeat + * in case qp gets into error state + */ + cq_size = wr_queue_size = SERVICE_CON_QUEUE_DEPTH * 3 + 2; + /* We must be the first here */ + if (WARN_ON(sess->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. + */ + sess->s.dev = ibtrs_ib_dev_find_or_add( + con->c.cm_id->device, &dev_pool); + if (unlikely(!sess->s.dev)) { + ibtrs_wrn(sess, "ibtrs_ib_dev_find_get_or_add(): no memory\n"); + return -ENOMEM; + } + sess->s.dev_ref = 1; + query_fast_reg_mode(sess); + } 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(!sess->s.dev)) + return -EINVAL; + if (WARN_ON(!sess->queue_depth)) + return -EINVAL; + + /* Shared between connections */ + sess->s.dev_ref++; + cq_size = wr_queue_size = + min_t(int, sess->s.dev->ib_dev->attrs.max_qp_wr, + /* QD * (REQ + RSP + FR REGS or INVS) + drain */ + sess->queue_depth * 3 + 1); + } + cq_vector = con->cpu % sess->s.dev->ib_dev->num_comp_vectors; + err = ibtrs_cq_qp_create(&sess->s, &con->c, sess->max_sge, + cq_vector, cq_size, wr_queue_size, + IB_POLL_SOFTIRQ); + /* + * In case of error we do not bother to clean previous allocations, + * since destroy_con_cq_qp() must be called. + */ + + if (unlikely(err)) + return err; + + return err; +} + +static void destroy_con_cq_qp(struct ibtrs_clt_con *con) +{ + struct ibtrs_clt_sess *sess = to_clt_sess(con->c.sess); + + /* + * Be careful here: destroy_con_cq_qp() can be called even + * create_con_cq_qp() failed, see comments there. + */ + + ibtrs_cq_qp_destroy(&con->c); + if (sess->s.dev_ref && !--sess->s.dev_ref) { + ibtrs_ib_dev_put(sess->s.dev); + sess->s.dev = NULL; + } +} + +static void stop_cm(struct ibtrs_clt_con *con) +{ + rdma_disconnect(con->c.cm_id); + if (con->c.qp) + ib_drain_qp(con->c.qp); +} + +static void destroy_cm(struct ibtrs_clt_con *con) +{ + rdma_destroy_id(con->c.cm_id); + con->c.cm_id = NULL; +} + +static int create_cm(struct ibtrs_clt_con *con) +{ + struct ibtrs_clt_sess *sess = to_clt_sess(con->c.sess); + struct rdma_cm_id *cm_id; + int err; + + cm_id = rdma_create_id(&init_net, ibtrs_clt_rdma_cm_handler, con, + sess->s.dst_addr.ss_family == AF_IB ? + RDMA_PS_IB : RDMA_PS_TCP, IB_QPT_RC); + if (unlikely(IS_ERR(cm_id))) { + err = PTR_ERR(cm_id); + ibtrs_err(sess, "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) { + ibtrs_err(sess, "Set address reuse failed, err: %d\n", err); + goto destroy_cm; + } + err = rdma_resolve_addr(cm_id, (struct sockaddr *)&sess->s.src_addr, + (struct sockaddr *)&sess->s.dst_addr, + IBTRS_CONNECT_TIMEOUT_MS); + if (unlikely(err)) { + ibtrs_err(sess, "Failed to resolve address, err: %d\n", err); + goto destroy_cm; + } + /* + * 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(sess->state_wq, + con->cm_err || sess->state != IBTRS_CLT_CONNECTING, + msecs_to_jiffies(IBTRS_CONNECT_TIMEOUT_MS)); + if (unlikely(err == 0 || err == -ERESTARTSYS)) { + if (err == 0) + err = -ETIMEDOUT; + /* Timedout or interrupted */ + goto errr; + } + if (unlikely(con->cm_err < 0)) { + err = con->cm_err; + goto errr; + } + if (unlikely(sess->state != IBTRS_CLT_CONNECTING)) { + /* Device removal */ + err = -ECONNABORTED; + goto errr; + } + + return 0; + +errr: + stop_cm(con); + /* Is safe to call destroy if cq_qp is not inited */ + destroy_con_cq_qp(con); +destroy_cm: + destroy_cm(con); + + return err; +} + +static void ibtrs_clt_sess_up(struct ibtrs_clt_sess *sess) +{ + struct ibtrs_clt *clt = sess->clt; + int up; + + /* + * We can fire RECONNECTED event only when all paths were + * connected on ibtrs_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 ibtrs_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, IBTRS_CLT_LINK_EV_RECONNECTED); + mutex_unlock(&clt->paths_ev_mutex); + + /* Mark session as established */ + sess->established = true; + sess->reconnect_attempts = 0; + sess->stats.reconnects.successful_cnt++; +} + +static void ibtrs_clt_sess_down(struct ibtrs_clt_sess *sess) +{ + struct ibtrs_clt *clt = sess->clt; + + if (!sess->established) + return; + + sess->established = false; + mutex_lock(&clt->paths_ev_mutex); + WARN_ON(!clt->paths_up); + if (--clt->paths_up == 0) + clt->link_ev(clt->priv, IBTRS_CLT_LINK_EV_DISCONNECTED); + mutex_unlock(&clt->paths_ev_mutex); +} + +static void ibtrs_clt_stop_and_destroy_conns(struct ibtrs_clt_sess *sess) +{ + struct ibtrs_clt_con *con; + unsigned int cid; + + WARN_ON(sess->state == IBTRS_CLT_CONNECTED); + + /* + * Possible race with ibtrs_clt_open(), when DEVICE_REMOVAL comes + * exactly in between. Start destroying after it finishes. + */ + mutex_lock(&sess->init_mutex); + mutex_unlock(&sess->init_mutex); + + /* + * All IO paths must observe !CONNECTED state before we + * free everything. + */ + synchronize_rcu(); + + ibtrs_clt_stop_hb(sess); + + /* + * 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 < sess->s.con_num; cid++) { + if (!sess->s.con[cid]) + break; + con = to_clt_con(sess->s.con[cid]); + stop_cm(con); + } + fail_all_outstanding_reqs(sess); + free_sess_reqs(sess); + ibtrs_clt_sess_down(sess); + + /* + * 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(sess->state_wq, !atomic_read(&sess->connected_cnt), + msecs_to_jiffies(IBTRS_CONNECT_TIMEOUT_MS)); + + for (cid = 0; cid < sess->s.con_num; cid++) { + if (!sess->s.con[cid]) + break; + con = to_clt_con(sess->s.con[cid]); + destroy_con_cq_qp(con); + destroy_cm(con); + destroy_con(con); + } +} + +static inline bool xchg_sessions(struct ibtrs_clt_sess __rcu **rcu_ppcpu_path, + struct ibtrs_clt_sess *sess, + struct ibtrs_clt_sess *next) +{ + struct ibtrs_clt_sess **ppcpu_path; + + /* Call cmpxchg() without sparse warnings */ + ppcpu_path = (typeof(ppcpu_path))rcu_ppcpu_path; + return (sess == cmpxchg(ppcpu_path, sess, next)); +} + +static void ibtrs_clt_remove_path_from_arr(struct ibtrs_clt_sess *sess) +{ + struct ibtrs_clt *clt = sess->clt; + struct ibtrs_clt_sess *next; + bool wait_for_grace = false; + int cpu; + + mutex_lock(&clt->paths_mutex); + list_del_rcu(&sess->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(): ibtrs_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. + */ + next = list_next_or_null_rr_rcu(&clt->paths_list, &sess->s.entry, + typeof(*next), s.entry); + + /* + * @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 ibtrs_clt_sess __rcu **ppcpu_path; + + ppcpu_path = per_cpu_ptr(clt->pcpu_path, cpu); + if (rcu_dereference(*ppcpu_path) != sess) + /* + * 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 (xchg_sessions(ppcpu_path, sess, 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 ibtrs_clt_add_path_to_arr(struct ibtrs_clt_sess *sess, + struct ibtrs_addr *addr) +{ + struct ibtrs_clt *clt = sess->clt; + + mutex_lock(&clt->paths_mutex); + clt->paths_num++; + + /* + * Firstly increase paths_num, wait for GP and then + * add path to the list. Why? Since we add path with + * !CONNECTED state explanation is similar to what has + * been written in ibtrs_clt_remove_path_from_arr(). + */ + synchronize_rcu(); + + list_add_tail_rcu(&sess->s.entry, &clt->paths_list); + mutex_unlock(&clt->paths_mutex); +} + +static void ibtrs_clt_close_work(struct work_struct *work) +{ + struct ibtrs_clt_sess *sess; + + sess = container_of(work, struct ibtrs_clt_sess, close_work); + + cancel_delayed_work_sync(&sess->reconnect_dwork); + ibtrs_clt_stop_and_destroy_conns(sess); + /* + * Sounds stupid, huh? No, it is not. Consider this sequence: + * + * #CPU0 #CPU1 + * 1. CONNECTED->RECONNECTING + * 2. RECONNECTING->CLOSING + * 3. queue_work(&reconnect_dwork) + * 4. queue_work(&close_work); + * 5. reconnect_work(); close_work(); + * + * To avoid that case do cancel twice: before and after. + */ + cancel_delayed_work_sync(&sess->reconnect_dwork); + ibtrs_clt_change_state(sess, IBTRS_CLT_CLOSED); +} + +static void ibtrs_clt_close_conns(struct ibtrs_clt_sess *sess, bool wait) +{ + if (ibtrs_clt_change_state(sess, IBTRS_CLT_CLOSING)) + queue_work(ibtrs_wq, &sess->close_work); + if (wait) + flush_work(&sess->close_work); +} + +static int init_conns(struct ibtrs_clt_sess *sess) +{ + unsigned int cid; + int err; + + /* + * On every new session connections increase reconnect counter + * to avoid clashes with previous sessions not yet closed + * sessions on a server side. + */ + sess->s.recon_cnt++; + + /* Establish all RDMA connections */ + for (cid = 0; cid < sess->s.con_num; cid++) { + err = create_con(sess, cid); + if (unlikely(err)) + goto destroy; + + err = create_cm(to_clt_con(sess->s.con[cid])); + if (unlikely(err)) { + destroy_con(to_clt_con(sess->s.con[cid])); + goto destroy; + } + } + err = alloc_sess_reqs(sess); + if (unlikely(err)) + goto destroy; + + ibtrs_clt_start_hb(sess); + + return 0; + +destroy: + while (cid--) { + struct ibtrs_clt_con *con = to_clt_con(sess->s.con[cid]); + + stop_cm(con); + destroy_con_cq_qp(con); + 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. + */ + ibtrs_clt_change_state(sess, IBTRS_CLT_CONNECTING_ERR); + + return err; +} + +static int ibtrs_rdma_addr_resolved(struct ibtrs_clt_con *con) +{ + struct ibtrs_clt_sess *sess = to_clt_sess(con->c.sess); + int err; + + err = create_con_cq_qp(con); + if (unlikely(err)) { + ibtrs_err(sess, "create_con_cq_qp(), err: %d\n", err); + return err; + } + err = rdma_resolve_route(con->c.cm_id, IBTRS_CONNECT_TIMEOUT_MS); + if (unlikely(err)) { + ibtrs_err(sess, "Resolving route failed, err: %d\n", err); + destroy_con_cq_qp(con); + } + + return err; +} + +static int ibtrs_rdma_route_resolved(struct ibtrs_clt_con *con) +{ + struct ibtrs_clt_sess *sess = to_clt_sess(con->c.sess); + struct ibtrs_clt *clt = sess->clt; + struct ibtrs_msg_conn_req msg; + struct rdma_conn_param param; + + int err; + + memset(¶m, 0, sizeof(param)); + param.retry_count = clamp(retry_cnt, MIN_RTR_CNT, MAX_RTR_CNT); + param.rnr_retry_count = 7; + param.private_data = &msg; + param.private_data_len = sizeof(msg); + + /* + * Those two are the part of struct cma_hdr which is shared + * with private_data in case of AF_IB, so put zeroes to avoid + * wrong validation inside cma.c on receiver side. + */ + msg.__cma_version = 0; + msg.__ip_version = 0; + msg.magic = cpu_to_le16(IBTRS_MAGIC); + msg.version = cpu_to_le16(IBTRS_PROTO_VER); + msg.cid = cpu_to_le16(con->c.cid); + msg.cid_num = cpu_to_le16(sess->s.con_num); + msg.recon_cnt = cpu_to_le16(sess->s.recon_cnt); + uuid_copy(&msg.sess_uuid, &sess->s.uuid); + uuid_copy(&msg.paths_uuid, &clt->paths_uuid); + + err = rdma_connect(con->c.cm_id, ¶m); + if (err) + ibtrs_err(sess, "rdma_connect(): %d\n", err); + + return err; +} + +static int ibtrs_rdma_conn_established(struct ibtrs_clt_con *con, + struct rdma_cm_event *ev) +{ + struct ibtrs_clt_sess *sess = to_clt_sess(con->c.sess); + struct ibtrs_clt *clt = sess->clt; + const struct ibtrs_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 (unlikely(len < sizeof(*msg))) { + ibtrs_err(sess, "Invalid IBTRS connection response\n"); + return -ECONNRESET; + } + if (unlikely(le16_to_cpu(msg->magic) != IBTRS_MAGIC)) { + ibtrs_err(sess, "Invalid IBTRS magic\n"); + return -ECONNRESET; + } + version = le16_to_cpu(msg->version); + if (unlikely(version >> 8 != IBTRS_PROTO_VER_MAJOR)) { + ibtrs_err(sess, "Unsupported major IBTRS version: %d, expected %d\n", + version >> 8, IBTRS_PROTO_VER_MAJOR); + return -ECONNRESET; + } + errno = le16_to_cpu(msg->errno); + if (unlikely(errno)) { + ibtrs_err(sess, "Invalid IBTRS message: errno %d\n", + errno); + return -ECONNRESET; + } + if (con->c.cid == 0) { + queue_depth = le16_to_cpu(msg->queue_depth); + + if (queue_depth > MAX_SESS_QUEUE_DEPTH) { + ibtrs_err(sess, "Invalid IBTRS message: queue=%d\n", + queue_depth); + return -ECONNRESET; + } + if (!sess->rbufs || sess->queue_depth < queue_depth) { + kfree(sess->rbufs); + sess->rbufs = kcalloc(queue_depth, sizeof(*sess->rbufs), + GFP_KERNEL); + if (unlikely(!sess->rbufs)) { + ibtrs_err(sess, "Failed to allocate " + "queue_depth=%d\n", queue_depth); + return -ENOMEM; + } + } + sess->queue_depth = queue_depth; + sess->max_hdr_size = le32_to_cpu(msg->max_hdr_size); + sess->max_io_size = le32_to_cpu(msg->max_io_size); + sess->chunk_size = sess->max_io_size + sess->max_hdr_size; + + /* + * Global queue depth and 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 = min_not_zero(sess->queue_depth, + clt->queue_depth); + clt->max_io_size = min_not_zero(sess->max_io_size, + clt->max_io_size); + mutex_unlock(&clt->paths_mutex); + + /* + * Cache the hca_port and hca_name for sysfs + */ + sess->hca_port = con->c.cm_id->port_num; + scnprintf(sess->hca_name, sizeof(sess->hca_name), + sess->s.dev->ib_dev->name); + sess->s.src_addr = con->c.cm_id->route.addr.src_addr; + } + + return 0; +} + +static int ibtrs_rdma_conn_rejected(struct ibtrs_clt_con *con, + struct rdma_cm_event *ev) +{ + struct ibtrs_clt_sess *sess = to_clt_sess(con->c.sess); + const struct ibtrs_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) + ibtrs_err(sess, + "Previous session is still exists on the " + "server, please reconnect later\n"); + else + ibtrs_err(sess, + "Connect rejected: status %d (%s), ibtrs " + "errno %d\n", status, rej_msg, errno); + } else { + ibtrs_err(sess, + "Connect rejected but with malformed message: " + "status %d (%s)\n", status, rej_msg); + } + + return -ECONNRESET; +} + +static void ibtrs_rdma_error_recovery(struct ibtrs_clt_con *con) +{ + struct ibtrs_clt_sess *sess = to_clt_sess(con->c.sess); + + if (ibtrs_clt_change_state_from_to(sess, + IBTRS_CLT_CONNECTED, + IBTRS_CLT_RECONNECTING)) { + /* + * Normal scenario, reconnect if we were successfully connected + */ + queue_delayed_work(ibtrs_wq, &sess->reconnect_dwork, 0); + } 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. + */ + ibtrs_clt_change_state_from_to(sess, + IBTRS_CLT_CONNECTING, + IBTRS_CLT_CONNECTING_ERR); + } +} + +static inline void flag_success_on_conn(struct ibtrs_clt_con *con) +{ + struct ibtrs_clt_sess *sess = to_clt_sess(con->c.sess); + + atomic_inc(&sess->connected_cnt); + con->cm_err = 1; +} + +static inline void flag_error_on_conn(struct ibtrs_clt_con *con, int cm_err) +{ + if (con->cm_err == 1) { + struct ibtrs_clt_sess *sess; + + sess = to_clt_sess(con->c.sess); + if (atomic_dec_and_test(&sess->connected_cnt)) + wake_up(&sess->state_wq); + } + con->cm_err = cm_err; +} + +static int ibtrs_clt_rdma_cm_handler(struct rdma_cm_id *cm_id, + struct rdma_cm_event *ev) +{ + struct ibtrs_clt_con *con = cm_id->context; + struct ibtrs_clt_sess *sess = to_clt_sess(con->c.sess); + int cm_err = 0; + + switch (ev->event) { + case RDMA_CM_EVENT_ADDR_RESOLVED: + cm_err = ibtrs_rdma_addr_resolved(con); + break; + case RDMA_CM_EVENT_ROUTE_RESOLVED: + cm_err = ibtrs_rdma_route_resolved(con); + break; + case RDMA_CM_EVENT_ESTABLISHED: + con->cm_err = ibtrs_rdma_conn_established(con, ev); + if (likely(!con->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(&sess->state_wq); + return 0; + } + break; + case RDMA_CM_EVENT_REJECTED: + cm_err = ibtrs_rdma_conn_rejected(con, ev); + break; + case RDMA_CM_EVENT_CONNECT_ERROR: + case RDMA_CM_EVENT_UNREACHABLE: + ibtrs_wrn(sess, "CM error event %d\n", ev->event); + cm_err = -ECONNRESET; + break; + case RDMA_CM_EVENT_ADDR_ERROR: + case RDMA_CM_EVENT_ROUTE_ERROR: + cm_err = -EHOSTUNREACH; + break; + case RDMA_CM_EVENT_DISCONNECTED: + case RDMA_CM_EVENT_ADDR_CHANGE: + case RDMA_CM_EVENT_TIMEWAIT_EXIT: + cm_err = -ECONNRESET; + break; + case RDMA_CM_EVENT_DEVICE_REMOVAL: + /* + * Device removal is a special case. Queue close and return 0. + */ + ibtrs_clt_close_conns(sess, false); + return 0; + default: + ibtrs_err(sess, "Unexpected RDMA CM event (%d)\n", ev->event); + 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); + ibtrs_rdma_error_recovery(con); + } + + return 0; +} + +static void ibtrs_clt_info_req_done(struct ib_cq *cq, struct ib_wc *wc) +{ + struct ibtrs_clt_con *con = cq->cq_context; + struct ibtrs_clt_sess *sess = to_clt_sess(con->c.sess); + struct ibtrs_iu *iu; + + iu = container_of(wc->wr_cqe, struct ibtrs_iu, cqe); + ibtrs_iu_free(iu, DMA_TO_DEVICE, sess->s.dev->ib_dev); + + if (unlikely(wc->status != IB_WC_SUCCESS)) { + ibtrs_err(sess, "Sess info request send failed: %s\n", + ib_wc_status_msg(wc->status)); + ibtrs_clt_change_state(sess, IBTRS_CLT_CONNECTING_ERR); + return; + } + + ibtrs_clt_update_wc_stats(con); +} + +static int process_info_rsp(struct ibtrs_clt_sess *sess, + const struct ibtrs_msg_info_rsp *msg) +{ + unsigned int sg_cnt, total_len; + int i, sgi; + + sg_cnt = le16_to_cpu(msg->sg_cnt); + if (unlikely(!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 (unlikely((ilog2(sg_cnt-1)+1) + (ilog2(sess->chunk_size-1)+1) > + MAX_IMM_PAYL_BITS)) { + ibtrs_err(sess, "RDMA immediate size (%db) not enough to " + "encode %d buffers of size %dB\n", MAX_IMM_PAYL_BITS, + sg_cnt, sess->chunk_size); + return -EINVAL; + } + if (unlikely(!sg_cnt || (sess->queue_depth % sg_cnt))) { + ibtrs_err(sess, "Incorrect sg_cnt %d, is not multiple\n", + sg_cnt); + return -EINVAL; + } + total_len = 0; + for (sgi = 0, i = 0; sgi < sg_cnt && i < sess->queue_depth; sgi++) { + const struct ibtrs_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 (unlikely(!len || (len % sess->chunk_size))) { + ibtrs_err(sess, "Incorrect [%d].len %d\n", sgi, len); + return -EINVAL; + } + for ( ; len && i < sess->queue_depth; i++) { + sess->rbufs[i].addr = addr; + sess->rbufs[i].rkey = rkey; + + len -= sess->chunk_size; + addr += sess->chunk_size; + } + } + /* Sanity check */ + if (unlikely(sgi != sg_cnt || i != sess->queue_depth)) { + ibtrs_err(sess, "Incorrect sg vector, not fully mapped\n"); + return -EINVAL; + } + if (unlikely(total_len != sess->chunk_size * sess->queue_depth)) { + ibtrs_err(sess, "Incorrect total_len %d\n", total_len); + return -EINVAL; + } + + return 0; +} + +static void ibtrs_clt_info_rsp_done(struct ib_cq *cq, struct ib_wc *wc) +{ + struct ibtrs_clt_con *con = cq->cq_context; + struct ibtrs_clt_sess *sess = to_clt_sess(con->c.sess); + struct ibtrs_msg_info_rsp *msg; + enum ibtrs_clt_state state; + struct ibtrs_iu *iu; + size_t rx_sz; + int err; + + state = IBTRS_CLT_CONNECTING_ERR; + + WARN_ON(con->c.cid); + iu = container_of(wc->wr_cqe, struct ibtrs_iu, cqe); + if (unlikely(wc->status != IB_WC_SUCCESS)) { + ibtrs_err(sess, "Sess info response recv failed: %s\n", + ib_wc_status_msg(wc->status)); + goto out; + } + WARN_ON(wc->opcode != IB_WC_RECV); + + if (unlikely(wc->byte_len < sizeof(*msg))) { + ibtrs_err(sess, "Sess info response is malformed: size %d\n", + wc->byte_len); + goto out; + } + ib_dma_sync_single_for_cpu(sess->s.dev->ib_dev, iu->dma_addr, + iu->size, DMA_FROM_DEVICE); + msg = iu->buf; + if (unlikely(le16_to_cpu(msg->type) != IBTRS_MSG_INFO_RSP)) { + ibtrs_err(sess, "Sess 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 (unlikely(wc->byte_len < rx_sz)) { + ibtrs_err(sess, "Sess info response is malformed: size %d\n", + wc->byte_len); + goto out; + } + err = process_info_rsp(sess, msg); + if (unlikely(err)) + goto out; + + err = post_recv_sess(sess); + if (unlikely(err)) + goto out; + + state = IBTRS_CLT_CONNECTED; + +out: + ibtrs_clt_update_wc_stats(con); + ibtrs_iu_free(iu, DMA_FROM_DEVICE, sess->s.dev->ib_dev); + ibtrs_clt_change_state(sess, state); +} + +static int ibtrs_send_sess_info(struct ibtrs_clt_sess *sess) +{ + struct ibtrs_clt_con *usr_con = to_clt_con(sess->s.con[0]); + struct ibtrs_msg_info_req *msg; + struct ibtrs_iu *tx_iu, *rx_iu; + size_t rx_sz; + int err; + + rx_sz = sizeof(struct ibtrs_msg_info_rsp); + rx_sz += sizeof(u64) * MAX_SESS_QUEUE_DEPTH; + + tx_iu = ibtrs_iu_alloc(0, sizeof(struct ibtrs_msg_info_req), GFP_KERNEL, + sess->s.dev->ib_dev, DMA_TO_DEVICE, + ibtrs_clt_info_req_done); + rx_iu = ibtrs_iu_alloc(0, rx_sz, GFP_KERNEL, sess->s.dev->ib_dev, + DMA_FROM_DEVICE, ibtrs_clt_info_rsp_done); + if (unlikely(!tx_iu || !rx_iu)) { + ibtrs_err(sess, "ibtrs_iu_alloc(): no memory\n"); + err = -ENOMEM; + goto out; + } + /* Prepare for getting info response */ + err = ibtrs_iu_post_recv(&usr_con->c, rx_iu); + if (unlikely(err)) { + ibtrs_err(sess, "ibtrs_iu_post_recv(), err: %d\n", err); + goto out; + } + rx_iu = NULL; + + msg = tx_iu->buf; + msg->type = cpu_to_le16(IBTRS_MSG_INFO_REQ); + memcpy(msg->sessname, sess->s.sessname, sizeof(msg->sessname)); + + ib_dma_sync_single_for_device(sess->s.dev->ib_dev, tx_iu->dma_addr, + tx_iu->size, DMA_TO_DEVICE); + + /* Send info request */ + err = ibtrs_iu_post_send(&usr_con->c, tx_iu, sizeof(*msg), NULL); + if (unlikely(err)) { + ibtrs_err(sess, "ibtrs_iu_post_send(), err: %d\n", err); + goto out; + } + tx_iu = NULL; + + /* Wait for state change */ + wait_event_interruptible_timeout(sess->state_wq, + sess->state != IBTRS_CLT_CONNECTING, + msecs_to_jiffies(IBTRS_CONNECT_TIMEOUT_MS)); + if (unlikely(sess->state != IBTRS_CLT_CONNECTED)) { + if (sess->state == IBTRS_CLT_CONNECTING_ERR) + err = -ECONNRESET; + else + err = -ETIMEDOUT; + goto out; + } + +out: + if (tx_iu) + ibtrs_iu_free(tx_iu, DMA_TO_DEVICE, sess->s.dev->ib_dev); + if (rx_iu) + ibtrs_iu_free(rx_iu, DMA_FROM_DEVICE, sess->s.dev->ib_dev); + if (unlikely(err)) + /* If we've never taken async path because of malloc problems */ + ibtrs_clt_change_state(sess, IBTRS_CLT_CONNECTING_ERR); + + return err; +} + +/** + * init_sess() - establishes all session connections and does handshake + * + * In case of error full close or reconnect procedure should be taken, + * because reconnect or close async works can be started. + */ +static int init_sess(struct ibtrs_clt_sess *sess) +{ + int err; + + mutex_lock(&sess->init_mutex); + err = init_conns(sess); + if (unlikely(err)) { + ibtrs_err(sess, "init_conns(), err: %d\n", err); + goto out; + } + err = ibtrs_send_sess_info(sess); + if (unlikely(err)) { + ibtrs_err(sess, "ibtrs_send_sess_info(), err: %d\n", err); + goto out; + } + ibtrs_clt_sess_up(sess); +out: + mutex_unlock(&sess->init_mutex); + + return err; +} + +static void ibtrs_clt_reconnect_work(struct work_struct *work) +{ + struct ibtrs_clt_sess *sess; + struct ibtrs_clt *clt; + unsigned int delay_ms; + int err; + + sess = container_of(to_delayed_work(work), struct ibtrs_clt_sess, + reconnect_dwork); + clt = sess->clt; + + if (ibtrs_clt_state(sess) == IBTRS_CLT_CLOSING) + /* User requested closing */ + return; + + if (sess->reconnect_attempts >= clt->max_reconnect_attempts) { + /* Close a session completely if max attempts is reached */ + ibtrs_clt_close_conns(sess, false); + return; + } + sess->reconnect_attempts++; + + /* Stop everything */ + ibtrs_clt_stop_and_destroy_conns(sess); + ibtrs_clt_change_state(sess, IBTRS_CLT_CONNECTING); + + err = init_sess(sess); + if (unlikely(err)) + goto reconnect_again; + + return; + +reconnect_again: + if (ibtrs_clt_change_state(sess, IBTRS_CLT_RECONNECTING)) { + sess->stats.reconnects.fail_cnt++; + delay_ms = clt->reconnect_delay_sec * 1000; + queue_delayed_work(ibtrs_wq, &sess->reconnect_dwork, + msecs_to_jiffies(delay_ms)); + } +} + +static void ibtrs_clt_dev_release(struct device *dev) +{ + /* Nobody plays with device references, so nop */ +} + +static struct ibtrs_clt *alloc_clt(const char *sessname, size_t paths_num, + short port, size_t pdu_sz, + void *priv, link_clt_ev_fn *link_ev, + unsigned int max_segments, + unsigned int reconnect_delay_sec, + unsigned int max_reconnect_attempts) +{ + struct ibtrs_clt *clt; + int err; + + if (unlikely(!paths_num || paths_num > MAX_PATHS_NUM)) + return ERR_PTR(-EINVAL); + + if (unlikely(strlen(sessname) >= sizeof(clt->sessname))) + return ERR_PTR(-EINVAL); + + clt = kzalloc(sizeof(*clt), GFP_KERNEL); + if (unlikely(!clt)) + return ERR_PTR(-ENOMEM); + + clt->pcpu_path = alloc_percpu(typeof(*clt->pcpu_path)); + if (unlikely(!clt->pcpu_path)) { + kfree(clt); + return ERR_PTR(-ENOMEM); + } + + 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 = 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; + strlcpy(clt->sessname, sessname, sizeof(clt->sessname)); + init_waitqueue_head(&clt->tags_wait); + mutex_init(&clt->paths_ev_mutex); + mutex_init(&clt->paths_mutex); + + clt->dev.class = ibtrs_dev_class; + clt->dev.release = ibtrs_clt_dev_release; + dev_set_name(&clt->dev, "%s", sessname); + + err = device_register(&clt->dev); + if (unlikely(err)) + goto percpu_free; + + err = ibtrs_clt_create_sysfs_root_folders(clt); + if (unlikely(err)) + goto dev_unregister; + + return clt; + +dev_unregister: + /* Nobody plays with dev refs, so dev.release() is nop */ + device_unregister(&clt->dev); +percpu_free: + free_percpu(clt->pcpu_path); + kfree(clt); + + return ERR_PTR(err); +} + +static void wait_for_inflight_tags(struct ibtrs_clt *clt) +{ + if (clt->tags_map) { + size_t sz = clt->queue_depth; + + wait_event(clt->tags_wait, + find_first_bit(clt->tags_map, sz) >= sz); + } +} + +static void free_clt(struct ibtrs_clt *clt) +{ + ibtrs_clt_destroy_sysfs_root_folders(clt); + wait_for_inflight_tags(clt); + free_tags(clt); + free_percpu(clt->pcpu_path); + /* Nobody plays with dev refs, so dev.release() is nop */ + device_unregister(&clt->dev); + kfree(clt); +} + +struct ibtrs_clt *ibtrs_clt_open(void *priv, link_clt_ev_fn *link_ev, + const char *sessname, + const struct ibtrs_addr *paths, + size_t paths_num, + short port, + size_t pdu_sz, u8 reconnect_delay_sec, + u16 max_segments, + s16 max_reconnect_attempts) +{ + struct ibtrs_clt_sess *sess, *tmp; + struct ibtrs_clt *clt; + int err, i; + + clt = alloc_clt(sessname, paths_num, port, pdu_sz, priv, link_ev, + max_segments, reconnect_delay_sec, + max_reconnect_attempts); + if (unlikely(IS_ERR(clt))) { + err = PTR_ERR(clt); + goto out; + } + for (i = 0; i < paths_num; i++) { + struct ibtrs_clt_sess *sess; + + sess = alloc_sess(clt, &paths[i], nr_cons_per_session, + max_segments); + if (unlikely(IS_ERR(sess))) { + err = PTR_ERR(sess); + ibtrs_err(clt, "alloc_sess(), err: %d\n", err); + goto close_all_sess; + } + list_add_tail_rcu(&sess->s.entry, &clt->paths_list); + + err = init_sess(sess); + if (unlikely(err)) + goto close_all_sess; + + err = ibtrs_clt_create_sess_files(sess); + if (unlikely(err)) + goto close_all_sess; + } + err = alloc_tags(clt); + if (unlikely(err)) { + ibtrs_err(clt, "alloc_tags(), err: %d\n", err); + goto close_all_sess; + } + err = ibtrs_clt_create_sysfs_root_files(clt); + if (unlikely(err)) + goto close_all_sess; + + /* + * There is a race if someone decides to completely remove just + * newly created path using sysfs entry. To avoid the race we + * use simple 'opened' flag, see ibtrs_clt_remove_path_from_sysfs(). + */ + clt->opened = true; + + /* Do not let module be unloaded if client is alive */ + __module_get(THIS_MODULE); + + return clt; + +close_all_sess: + list_for_each_entry_safe(sess, tmp, &clt->paths_list, s.entry) { + ibtrs_clt_destroy_sess_files(sess, NULL); + ibtrs_clt_close_conns(sess, true); + free_sess(sess); + } + free_clt(clt); + +out: + return ERR_PTR(err); +} +EXPORT_SYMBOL(ibtrs_clt_open); + +void ibtrs_clt_close(struct ibtrs_clt *clt) +{ + struct ibtrs_clt_sess *sess, *tmp; + + /* Firstly forbid sysfs access */ + ibtrs_clt_destroy_sysfs_root_files(clt); + ibtrs_clt_destroy_sysfs_root_folders(clt); + + /* Now it is safe to iterate over all paths without locks */ + list_for_each_entry_safe(sess, tmp, &clt->paths_list, s.entry) { + ibtrs_clt_destroy_sess_files(sess, NULL); + ibtrs_clt_close_conns(sess, true); + free_sess(sess); + } + free_clt(clt); + module_put(THIS_MODULE); +} +EXPORT_SYMBOL(ibtrs_clt_close); + +int ibtrs_clt_reconnect_from_sysfs(struct ibtrs_clt_sess *sess) +{ + enum ibtrs_clt_state old_state; + int err = -EBUSY; + bool changed; + + changed = ibtrs_clt_change_state_get_old(sess, IBTRS_CLT_RECONNECTING, + &old_state); + if (changed) { + sess->reconnect_attempts = 0; + queue_delayed_work(ibtrs_wq, &sess->reconnect_dwork, 0); + } + if (changed || old_state == IBTRS_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(&sess->reconnect_dwork); + err = ibtrs_clt_sess_is_connected(sess) ? 0 : -ENOTCONN; + } + + return err; +} + +int ibtrs_clt_disconnect_from_sysfs(struct ibtrs_clt_sess *sess) +{ + ibtrs_clt_close_conns(sess, true); + + return 0; +} + +int ibtrs_clt_remove_path_from_sysfs(struct ibtrs_clt_sess *sess, + const struct attribute *sysfs_self) +{ + struct ibtrs_clt *clt = sess->clt; + enum ibtrs_clt_state old_state; + bool changed; + + /* + * That can happen only when userspace tries to remove path + * very early, when ibtrs_clt_open() is not yet finished. + */ + if (unlikely(!clt->opened)) + return -EBUSY; + + /* + * 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 ibtrs_clt_reconnect(), which can again start + * reconnecting. + * 2. State was observed as DEAD - we have someone in parallel + * removing the path. + */ + do { + ibtrs_clt_close_conns(sess, true); + } while (!(changed = ibtrs_clt_change_state_get_old(sess, + IBTRS_CLT_DEAD, + &old_state)) && + old_state != IBTRS_CLT_DEAD); + + /* + * If state was successfully changed to DEAD, commit suicide. + */ + if (likely(changed)) { + ibtrs_clt_destroy_sess_files(sess, sysfs_self); + ibtrs_clt_remove_path_from_arr(sess); + free_sess(sess); + } + + return 0; +} + +void ibtrs_clt_set_max_reconnect_attempts(struct ibtrs_clt *clt, int value) +{ + clt->max_reconnect_attempts = (unsigned int)value; +} + +int ibtrs_clt_get_max_reconnect_attempts(const struct ibtrs_clt *clt) +{ + return (int)clt->max_reconnect_attempts; +} + +static int ibtrs_post_rdma_write_sg(struct ibtrs_clt_con *con, + struct ibtrs_clt_io_req *req, + struct ibtrs_rbuf *rbuf, + u32 size, u32 imm) +{ + struct ibtrs_clt_sess *sess = to_clt_sess(con->c.sess); + struct ib_sge *sge = req->sge; + enum ib_send_flags flags; + struct scatterlist *sg; + size_t num_sge; + int i; + + for_each_sg(req->sglist, sg, req->sg_cnt, i) { + sge[i].addr = sg_dma_address(sg); + sge[i].length = sg_dma_len(sg); + sge[i].lkey = sess->s.dev->ib_pd->local_dma_lkey; + } + sge[i].addr = req->iu->dma_addr; + sge[i].length = size; + sge[i].lkey = sess->s.dev->ib_pd->local_dma_lkey; + + num_sge = 1 + req->sg_cnt; + + /* + * 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->io_cnt) % sess->queue_depth ? + 0 : IB_SEND_SIGNALED; + + ib_dma_sync_single_for_device(sess->s.dev->ib_dev, req->iu->dma_addr, + size, DMA_TO_DEVICE); + + return ibtrs_iu_post_rdma_write_imm(&con->c, req->iu, sge, num_sge, + rbuf->rkey, rbuf->addr, imm, + flags, NULL); +} + +static int ibtrs_clt_write_req(struct ibtrs_clt_io_req *req) +{ + struct ibtrs_clt_con *con = req->con; + struct ibtrs_clt_sess *sess = to_clt_sess(con->c.sess); + struct ibtrs_msg_rdma_write *msg; + + struct ibtrs_rbuf *rbuf; + int ret, count = 0; + u32 imm, buf_id; + + const size_t tsize = sizeof(*msg) + req->data_len + req->usr_len; + + if (unlikely(tsize > sess->chunk_size)) { + ibtrs_wrn(sess, "Write request failed, size too big %zu > %d\n", + tsize, sess->chunk_size); + return -EMSGSIZE; + } + if (req->sg_cnt) { + count = ib_dma_map_sg(sess->s.dev->ib_dev, req->sglist, + req->sg_cnt, req->dir); + if (unlikely(!count)) { + ibtrs_wrn(sess, "Write request failed, map failed\n"); + return -EINVAL; + } + } + /* put ibtrs msg after sg and user message */ + msg = req->iu->buf + req->usr_len; + msg->type = cpu_to_le16(IBTRS_MSG_WRITE); + msg->usr_len = cpu_to_le16(req->usr_len); + + /* ibtrs message on server side will be after user data and message */ + imm = req->tag->mem_off + req->data_len + req->usr_len; + imm = ibtrs_to_io_req_imm(imm); + buf_id = req->tag->mem_id; + req->sg_size = tsize; + rbuf = &sess->rbufs[buf_id]; + + /* + * Update stats now, after request is successfully sent it is not + * safe anymore to touch it. + */ + ibtrs_clt_update_all_stats(req, WRITE); + + ret = ibtrs_post_rdma_write_sg(req->con, req, rbuf, + req->usr_len + sizeof(*msg), + imm); + if (unlikely(ret)) { + ibtrs_err(sess, "Write request failed: %d\n", ret); + ibtrs_clt_decrease_inflight(&sess->stats); + if (req->sg_cnt) + ib_dma_unmap_sg(sess->s.dev->ib_dev, req->sglist, + req->sg_cnt, req->dir); + } + + return ret; +} + +static int ibtrs_map_sg_fr(struct ibtrs_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 (unlikely(nr < req->sg_cnt)) { + if (nr < 0) + return nr; + return -EINVAL; + } + ib_update_fast_reg_key(req->mr, ib_inc_rkey(req->mr->rkey)); + + return nr; +} + +static int ibtrs_clt_read_req(struct ibtrs_clt_io_req *req) +{ + struct ibtrs_clt_con *con = req->con; + struct ibtrs_clt_sess *sess = to_clt_sess(con->c.sess); + struct ibtrs_msg_rdma_read *msg; + struct ibtrs_ib_dev *dev; + struct scatterlist *sg; + + struct ib_reg_wr rwr; + struct ib_send_wr *wr = NULL; + + int i, ret, count = 0; + u32 imm, buf_id; + + const size_t tsize = sizeof(*msg) + req->data_len + req->usr_len; + + dev = sess->s.dev; + + if (unlikely(tsize > sess->chunk_size)) { + ibtrs_wrn(sess, "Read request failed, message size is" + " %zu, bigger than CHUNK_SIZE %d\n", tsize, + sess->chunk_size); + return -EMSGSIZE; + } + + if (req->sg_cnt) { + count = ib_dma_map_sg(dev->ib_dev, req->sglist, req->sg_cnt, + req->dir); + if (unlikely(!count)) { + ibtrs_wrn(sess, "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(IBTRS_MSG_READ); + msg->usr_len = cpu_to_le16(req->usr_len); + + if (count > noreg_cnt) { + ret = ibtrs_map_sg_fr(req, count); + if (ret < 0) { + ibtrs_err_rl(sess, + "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; + } + memset(&rwr, 0, sizeof(rwr)); + rwr.wr.next = NULL; + rwr.wr.opcode = IB_WR_REG_MR; + rwr.wr.wr_cqe = &fast_reg_cqe; + rwr.wr.num_sge = 0; + rwr.mr = req->mr; + rwr.key = req->mr->rkey; + rwr.access = (IB_ACCESS_LOCAL_WRITE | + IB_ACCESS_REMOTE_WRITE); + wr = &rwr.wr; + + msg->sg_cnt = cpu_to_le16(1); + msg->flags = cpu_to_le16(ibtrs_invalidate_flag()); + + 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 = !!ibtrs_invalidate_flag(); + + } else { + msg->sg_cnt = cpu_to_le16(count); + msg->flags = 0; + + for_each_sg(req->sglist, sg, req->sg_cnt, i) { + msg->desc[i].addr = cpu_to_le64(sg_dma_address(sg)); + msg->desc[i].key = cpu_to_le32(dev->ib_pd->unsafe_global_rkey); + msg->desc[i].len = cpu_to_le32(sg_dma_len(sg)); + } + } + /* + * ibtrs message will be after the space reserved for disk data and + * user message + */ + imm = req->tag->mem_off + req->data_len + req->usr_len; + imm = ibtrs_to_io_req_imm(imm); + buf_id = req->tag->mem_id; + + req->sg_size = sizeof(*msg); + req->sg_size += le16_to_cpu(msg->sg_cnt) * sizeof(struct ibtrs_sg_desc); + req->sg_size += req->usr_len; + + /* + * Update stats now, after request is successfully sent it is not + * safe anymore to touch it. + */ + ibtrs_clt_update_all_stats(req, READ); + + ret = ibtrs_post_send_rdma(req->con, req, &sess->rbufs[buf_id], + req->data_len, imm, wr); + if (unlikely(ret)) { + ibtrs_err(sess, "Read request failed: %d\n", ret); + ibtrs_clt_decrease_inflight(&sess->stats); + req->need_inv = false; + if (req->sg_cnt) + ib_dma_unmap_sg(dev->ib_dev, req->sglist, + req->sg_cnt, req->dir); + } + + return ret; +} + +int ibtrs_clt_request(int dir, ibtrs_conf_fn *conf, struct ibtrs_clt *clt, + struct ibtrs_tag *tag, void *priv, const struct kvec *vec, + size_t nr, size_t data_len, struct scatterlist *sg, + unsigned int sg_cnt) +{ + struct ibtrs_clt_io_req *req; + struct ibtrs_clt_sess *sess; + + 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 ibtrs_msg_rdma_read) + + sg_cnt * sizeof(struct ibtrs_sg_desc); + dma_dir = DMA_FROM_DEVICE; + } else { + hdr_len = sizeof(struct ibtrs_msg_rdma_write); + dma_dir = DMA_TO_DEVICE; + } + + do_each_path(sess, clt, &it) { + if (unlikely(sess->state != IBTRS_CLT_CONNECTED)) + continue; + + if (unlikely(usr_len + hdr_len > sess->max_hdr_size)) { + ibtrs_wrn_rl(sess, "%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, sess->max_hdr_size); + err = -EMSGSIZE; + break; + } + req = ibtrs_clt_get_req(sess, conf, tag, priv, vec, usr_len, + sg, sg_cnt, data_len, dma_dir); + if (dir == READ) + err = ibtrs_clt_read_req(req); + else + err = ibtrs_clt_write_req(req); + if (unlikely(err)) { + req->in_use = false; + continue; + } + /* Success path */ + break; + } while_each_path(&it); + + return err; +} +EXPORT_SYMBOL(ibtrs_clt_request); + +int ibtrs_clt_query(struct ibtrs_clt *clt, struct ibtrs_attrs *attr) +{ + if (unlikely(!ibtrs_clt_is_connected(clt))) + return -ECOMM; + + attr->queue_depth = clt->queue_depth; + attr->max_io_size = clt->max_io_size; + attr->sess_kobj = &clt->dev.kobj; + strlcpy(attr->sessname, clt->sessname, sizeof(attr->sessname)); + + return 0; +} +EXPORT_SYMBOL(ibtrs_clt_query); + +int ibtrs_clt_create_path_from_sysfs(struct ibtrs_clt *clt, + struct ibtrs_addr *addr) +{ + struct ibtrs_clt_sess *sess; + int err; + + sess = alloc_sess(clt, addr, nr_cons_per_session, clt->max_segments); + if (unlikely(IS_ERR(sess))) + return PTR_ERR(sess); + + /* + * 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. + */ + ibtrs_clt_add_path_to_arr(sess, addr); + + err = init_sess(sess); + if (unlikely(err)) + goto close_sess; + + err = ibtrs_clt_create_sess_files(sess); + if (unlikely(err)) + goto close_sess; + + return 0; + +close_sess: + ibtrs_clt_remove_path_from_arr(sess); + ibtrs_clt_close_conns(sess, true); + free_sess(sess); + + return err; +} + +static int check_module_params(void) +{ + if (nr_cons_per_session == 0) + nr_cons_per_session = min_t(unsigned int, nr_cpu_ids, U16_MAX); + + return 0; +} + +static int ibtrs_clt_ib_dev_init(struct ibtrs_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 ibtrs_ib_dev_pool_ops dev_pool_ops = { + .init = ibtrs_clt_ib_dev_init +}; + +static int __init ibtrs_client_init(void) +{ + int err; + + pr_info("Loading module %s, version %s, proto %s: " + "(retry_cnt: %d, noreg_cnt: %d)\n", + KBUILD_MODNAME, IBTRS_VER_STRING, IBTRS_PROTO_VER_STRING, + retry_cnt, noreg_cnt); + + ibtrs_ib_dev_pool_init(noreg_cnt ? IB_PD_UNSAFE_GLOBAL_RKEY : 0, + &dev_pool); + + err = check_module_params(); + if (unlikely(err)) { + pr_err("Failed to load module, invalid module parameters," + " err: %d\n", err); + return err; + } + ibtrs_dev_class = class_create(THIS_MODULE, "ibtrs-client"); + if (unlikely(IS_ERR(ibtrs_dev_class))) { + pr_err("Failed to create ibtrs-client dev class\n"); + return PTR_ERR(ibtrs_dev_class); + } + ibtrs_wq = alloc_workqueue("ibtrs_client_wq", WQ_MEM_RECLAIM, 0); + if (unlikely(!ibtrs_wq)) { + pr_err("Failed to load module, alloc ibtrs_client_wq failed\n"); + class_destroy(ibtrs_dev_class); + return -ENOMEM; + } + + return 0; +} + +static void __exit ibtrs_client_exit(void) +{ + destroy_workqueue(ibtrs_wq); + class_destroy(ibtrs_dev_class); + ibtrs_ib_dev_pool_deinit(&dev_pool); +} + +module_init(ibtrs_client_init); +module_exit(ibtrs_client_exit); -- 2.13.1 -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
