[PATCH 05/24] ibtrs: client: main functionality

Roman Pen
2018-02-02T14:08:45Z

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@profitbricks.com>
Signed-off-by: Danil Kipnis <danil.kipnis@profitbricks.com>
Cc: Jack Wang <jinpu.wang@profitbricks.com>
---
drivers/infiniband/ulp/ibtrs/ibtrs-clt.c | 3496 ++++++++++++++++++++++++++++++
1 file changed, 3496 insertions(+)

diff --git a/drivers/infiniband/ulp/ibtrs/ibtrs-clt.c b/drivers/infiniband/ulp/ibtrs/ibtrs-clt.c
new file mode 100644
index 000000000000..aa0a17f2a78c
--- /dev/null
+++ b/drivers/infiniband/ulp/ibtrs/ibtrs-clt.c
@@ -0,0 +1,3496 @@
+/*
+ * InfiniBand Transport Layer
+ *
+ * Copyright (c) 2014 - 2017 ProfitBricks GmbH. All rights reserved.
+ * Authors: Fabian Holler <mail@fholler.de>
+ * Jack Wang <jinpu.wang@profitbricks.com>
+ * Kleber Souza <kleber.souza@profitbricks.com>
+ * Danil Kipnis <danil.kipnis@profitbricks.com>
+ * Roman Penyaev <roman.penyaev@profitbricks.com>
+ * Milind Dumbare <Milind.dumbare@gmail.com>
+ *
+ * Copyright (c) 2017 - 2018 ProfitBricks GmbH. All rights reserved.
+ * Authors: Danil Kipnis <danil.kipnis@profitbricks.com>
+ * Roman Penyaev <roman.penyaev@profitbricks.com>
+ *
+ * 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 <rdma/ib_fmr_pool.h>
+
+#include "ibtrs-clt.h"
+#include "ibtrs-log.h"
+
+#define RECONNECT_SEED 8
+#define MAX_SEGMENTS 31
+
+#define IBTRS_CONNECT_TIMEOUT_MS 5000
+
+MODULE_AUTHOR("ibnbd@profitbricks.com");
+MODULE_DESCRIPTION("IBTRS Client");
+MODULE_VERSION(IBTRS_VER_STRING);
+MODULE_LICENSE("GPL");
+
+static bool use_fr;
+module_param(use_fr, bool, 0444);
+MODULE_PARM_DESC(use_fr, "use FRWR mode for memory registration if possible."
+ " (default: 0)");
+
+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_count = 7;
+
+static int retry_count_set(const char *val, const struct kernel_param *kp)
+{
+ int err, ival;
+
+ err = kstrtoint(val, 0, &ival);
+ if (err)
+ return err;
+
+ if (ival < MIN_RTR_CNT || ival > MAX_RTR_CNT)
+ return -EINVAL;
+
+ retry_count = ival;
+
+ return 0;
+}
+
+static const struct kernel_param_ops retry_count_ops = {
+ .set = retry_count_set,
+ .get = param_get_int,
+};
+module_param_cb(retry_count, &retry_count_ops, &retry_count, 0644);
+
+MODULE_PARM_DESC(retry_count, "Number of times to send the message if the"
+ " remote side didn't respond with Ack or Nack (default: 3,"
+ " min: " __stringify(MIN_RTR_CNT) ", max: "
+ __stringify(MAX_RTR_CNT) ")");
+
+static int fmr_sg_cnt = 4;
+module_param_named(fmr_sg_cnt, fmr_sg_cnt, int, 0644);
+MODULE_PARM_DESC(fmr_sg_cnt, "when sg_cnt is bigger than fmr_sg_cnt, enable"
+ " FMR (default: 4)");
+
+static struct workqueue_struct *ibtrs_wq;
+
+static void ibtrs_rdma_error_recovery(struct ibtrs_clt_con *con);
+static void ibtrs_clt_rdma_done(struct ib_cq *cq, struct ib_wc *wc);
+
+static inline void ibtrs_clt_state_lock(void)
+{
+ rcu_read_lock();
+}
+
+static inline void ibtrs_clt_state_unlock(void)
+{
+ rcu_read_unlock();
+}
+
+#define cmpxchg_min(var, new) ({ \
+ typeof(var) old; \
+ \
+ do { \
+ old = var; \
+ new = (!old ? new : min_t(typeof(var), old, new)); \
+ } while (cmpxchg(&var, old, new) != old); \
+})
+
+static void ibtrs_clt_set_min_queue_depth(struct ibtrs_clt *clt, size_t new)
+{
+ /* Can be updated from different sessions (paths), so cmpxchg */
+
+ cmpxchg_min(clt->queue_depth, new);
+}
+
+static void ibtrs_clt_set_min_io_size(struct ibtrs_clt *clt, size_t new)
+{
+ /* Can be updated from different sessions (paths), so cmpxchg */
+
+ cmpxchg_min(clt->max_io_size, new);
+}
+
+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;
+
+ ibtrs_clt_state_lock();
+ list_for_each_entry_rcu(sess, &clt->paths_list, s.entry)
+ connected |= ibtrs_clt_sess_is_connected(sess);
+ ibtrs_clt_state_unlock();
+
+ return connected;
+}
+
+/**
+ * struct ibtrs_fr_desc - fast registration work request arguments
+ * @entry: Entry in ibtrs_fr_pool.free_list.
+ * @mr: Memory region.
+ */
+struct ibtrs_fr_desc {
+ struct list_head entry;
+ struct ib_mr *mr;
+};
+
+/**
+ * struct ibtrs_fr_pool - pool of fast registration descriptors
+ *
+ * An entry is available for allocation if and only if it occurs in @free_list.
+ *
+ * @size: Number of descriptors in this pool.
+ * @max_page_list_len: Maximum fast registration work request page list length.
+ * @lock: Protects free_list.
+ * @free_list: List of free descriptors.
+ * @desc: Fast registration descriptor pool.
+ */
+struct ibtrs_fr_pool {
+ int size;
+ int max_page_list_len;
+ spinlock_t lock; /* protects free_list */
+ struct list_head free_list;
+ struct ibtrs_fr_desc desc[0];
+};
+
+/**
+ * struct ibtrs_map_state - per-request DMA memory mapping state
+ * @desc: Pointer to the element of the buffer descriptor array
+ * that is being filled in.
+ * @pages: Array with DMA addresses of pages being considered for
+ * memory registration.
+ * @base_dma_addr: DMA address of the first page that has not yet been mapped.
+ * @dma_len: Number of bytes that will be registered with the next
+ * FMR or FR memory registration call.
+ * @total_len: Total number of bytes in the sg-list being mapped.
+ * @npages: Number of page addresses in the pages[] array.
+ * @nmdesc: Number of FMR or FR memory descriptors used for mapping.
+ * @ndesc: Number of buffer descriptors that have been filled in.
+ */
+struct ibtrs_map_state {
+ union {
+ struct ib_pool_fmr **next_fmr;
+ struct ibtrs_fr_desc **next_fr;
+ };
+ struct ibtrs_sg_desc *desc;
+ union {
+ u64 *pages;
+ struct scatterlist *sg;
+ };
+ dma_addr_t base_dma_addr;
+ u32 dma_len;
+ u32 total_len;
+ u32 npages;
+ u32 nmdesc;
+ u32 ndesc;
+ enum dma_data_direction dir;
+};
+
+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);
+
+/**
+ * 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]);
+}
+
+/**
+ * ibtrs_destroy_fr_pool() - free the resources owned by a pool
+ * @pool: Fast registration pool to be destroyed.
+ */
+static void ibtrs_destroy_fr_pool(struct ibtrs_fr_pool *pool)
+{
+ struct ibtrs_fr_desc *d;
+ int i, err;
+
+ if (!pool)
+ return;
+
+ for (i = 0, d = &pool->desc[0]; i < pool->size; i++, d++) {
+ if (d->mr) {
+ err = ib_dereg_mr(d->mr);
+ if (err)
+ pr_err("Failed to deregister memory region,"
+ " err: %d\n", err);
+ }
+ }
+ kfree(pool);
+}
+
+/**
+ * ibtrs_create_fr_pool() - allocate and initialize a pool for fast registration
+ * @device: IB device to allocate fast registration descriptors for.
+ * @pd: Protection domain associated with the FR descriptors.
+ * @pool_size: Number of descriptors to allocate.
+ * @max_page_list_len: Maximum fast registration work request page list length.
+ */
+static struct ibtrs_fr_pool *ibtrs_create_fr_pool(struct ib_device *device,
+ struct ib_pd *pd,
+ int pool_size,
+ int max_page_list_len)
+{
+ struct ibtrs_fr_pool *pool;
+ struct ibtrs_fr_desc *d;
+ struct ib_mr *mr;
+ int i, ret;
+
+ if (pool_size <= 0) {
+ pr_warn("Creating fr pool failed, invalid pool size %d\n",
+ pool_size);
+ ret = -EINVAL;
+ goto err;
+ }
+
+ pool = kzalloc(sizeof(*pool) + pool_size * sizeof(*d), GFP_KERNEL);
+ if (!pool) {
+ ret = -ENOMEM;
+ goto err;
+ }
+
+ pool->size = pool_size;
+ pool->max_page_list_len = max_page_list_len;
+ spin_lock_init(&pool->lock);
+ INIT_LIST_HEAD(&pool->free_list);
+
+ for (i = 0, d = &pool->desc[0]; i < pool->size; i++, d++) {
+ mr = ib_alloc_mr(pd, IB_MR_TYPE_MEM_REG, max_page_list_len);
+ if (IS_ERR(mr)) {
+ pr_warn("Failed to allocate fast region memory\n");
+ ret = PTR_ERR(mr);
+ goto destroy_pool;
+ }
+ d->mr = mr;
+ list_add_tail(&d->entry, &pool->free_list);
+ }
+
+ return pool;
+
+destroy_pool:
+ ibtrs_destroy_fr_pool(pool);
+err:
+ return ERR_PTR(ret);
+}
+
+/**
+ * ibtrs_fr_pool_get() - obtain a descriptor suitable for fast registration
+ * @pool: Pool to obtain descriptor from.
+ */
+static struct ibtrs_fr_desc *ibtrs_fr_pool_get(struct ibtrs_fr_pool *pool)
+{
+ struct ibtrs_fr_desc *d = NULL;
+
+ spin_lock_bh(&pool->lock);
+ if (!list_empty(&pool->free_list)) {
+ d = list_first_entry(&pool->free_list, typeof(*d), entry);
+ list_del(&d->entry);
+ }
+ spin_unlock_bh(&pool->lock);
+
+ return d;
+}
+
+/**
+ * ibtrs_fr_pool_put() - put an FR descriptor back in the free list
+ * @pool: Pool the descriptor was allocated from.
+ * @desc: Pointer to an array of fast registration descriptor pointers.
+ * @n: Number of descriptors to put back.
+ *
+ * Note: The caller must already have queued an invalidation request for
+ * desc->mr->rkey before calling this function.
+ */
+static void ibtrs_fr_pool_put(struct ibtrs_fr_pool *pool,
+ struct ibtrs_fr_desc **desc, int n)
+{
+ int i;
+
+ spin_lock_bh(&pool->lock);
+ for (i = 0; i < n; i++)
+ list_add(&desc[i]->entry, &pool->free_list);
+ spin_unlock_bh(&pool->lock);
+}
+
+static void ibtrs_map_desc(struct ibtrs_map_state *state, dma_addr_t dma_addr,
+ u32 dma_len, u32 rkey, u32 max_desc)
+{
+ struct ibtrs_sg_desc *desc = state->desc;
+
+ pr_debug("dma_addr %llu, key %u, dma_len %u\n",
+ dma_addr, rkey, dma_len);
+ desc->addr = cpu_to_le64(dma_addr);
+ desc->key = cpu_to_le32(rkey);
+ desc->len = cpu_to_le32(dma_len);
+
+ state->total_len += dma_len;
+ if (state->ndesc < max_desc) {
+ state->desc++;
+ state->ndesc++;
+ } else {
+ state->ndesc = INT_MIN;
+ pr_err("Could not fit S/G list into buffer descriptor %d.\n",
+ max_desc);
+ }
+}
+
+static int ibtrs_map_finish_fmr(struct ibtrs_map_state *state,
+ struct ibtrs_clt_con *con)
+{
+ struct ibtrs_clt_sess *sess = to_clt_sess(con->c.sess);
+ struct ib_pool_fmr *fmr;
+ dma_addr_t dma_addr;
+ u64 io_addr = 0;
+
+ fmr = ib_fmr_pool_map_phys(sess->fmr_pool, state->pages,
+ state->npages, io_addr);
+ if (IS_ERR(fmr)) {
+ ibtrs_wrn_rl(sess, "Failed to map FMR from FMR pool, "
+ "err: %ld\n", PTR_ERR(fmr));
+ return PTR_ERR(fmr);
+ }
+
+ *state->next_fmr++ = fmr;
+ state->nmdesc++;
+ dma_addr = state->base_dma_addr & ~sess->mr_page_mask;
+ pr_debug("ndesc = %d, nmdesc = %d, npages = %d\n",
+ state->ndesc, state->nmdesc, state->npages);
+ if (state->dir == DMA_TO_DEVICE)
+ ibtrs_map_desc(state, dma_addr, state->dma_len, fmr->fmr->lkey,
+ sess->max_desc);
+ else
+ ibtrs_map_desc(state, dma_addr, state->dma_len, fmr->fmr->rkey,
+ sess->max_desc);
+
+ return 0;
+}
+
+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
+};
+
+/* TODO */
+static int ibtrs_map_finish_fr(struct ibtrs_map_state *state,
+ struct ibtrs_clt_con *con, int sg_cnt,
+ unsigned int *sg_offset_p)
+{
+ struct ibtrs_clt_sess *sess = to_clt_sess(con->c.sess);
+ struct ibtrs_fr_desc *desc;
+ struct ib_send_wr *bad_wr;
+ struct ib_reg_wr wr;
+ struct ib_pd *pd;
+ u32 rkey;
+ int n;
+
+ pd = sess->s.ib_dev->pd;
+ if (sg_cnt == 1 && (pd->flags & IB_PD_UNSAFE_GLOBAL_RKEY)) {
+ unsigned int sg_offset = sg_offset_p ? *sg_offset_p : 0;
+
+ ibtrs_map_desc(state, sg_dma_address(state->sg) + sg_offset,
+ sg_dma_len(state->sg) - sg_offset,
+ pd->unsafe_global_rkey, sess->max_desc);
+ if (sg_offset_p)
+ *sg_offset_p = 0;
+ return 1;
+ }
+
+ desc = ibtrs_fr_pool_get(con->fr_pool);
+ if (!desc) {
+ ibtrs_wrn_rl(sess, "Failed to get descriptor from FR pool\n");
+ return -ENOMEM;
+ }
+
+ rkey = ib_inc_rkey(desc->mr->rkey);
+ ib_update_fast_reg_key(desc->mr, rkey);
+
+ memset(&wr, 0, sizeof(wr));
+ n = ib_map_mr_sg(desc->mr, state->sg, sg_cnt, sg_offset_p,
+ sess->mr_page_size);
+ if (unlikely(n < 0)) {
+ ibtrs_fr_pool_put(con->fr_pool, &desc, 1);
+ return n;
+ }
+
+ wr.wr.next = NULL;
+ wr.wr.opcode = IB_WR_REG_MR;
+ wr.wr.wr_cqe = &fast_reg_cqe;
+ wr.wr.num_sge = 0;
+ wr.wr.send_flags = 0;
+ wr.mr = desc->mr;
+ wr.key = desc->mr->rkey;
+ wr.access = (IB_ACCESS_LOCAL_WRITE | IB_ACCESS_REMOTE_WRITE);
+
+ *state->next_fr++ = desc;
+ state->nmdesc++;
+
+ ibtrs_map_desc(state, state->base_dma_addr, state->dma_len,
+ desc->mr->rkey, sess->max_desc);
+
+ return ib_post_send(con->c.qp, &wr.wr, &bad_wr);
+}
+
+static int ibtrs_finish_fmr_mapping(struct ibtrs_map_state *state,
+ struct ibtrs_clt_con *con)
+{
+ struct ibtrs_clt_sess *sess = to_clt_sess(con->c.sess);
+ struct ib_pd *pd = sess->s.ib_dev->pd;
+ int ret = 0;
+
+ if (state->npages == 0)
+ return 0;
+
+ if (state->npages == 1 && (pd->flags & IB_PD_UNSAFE_GLOBAL_RKEY))
+ ibtrs_map_desc(state, state->base_dma_addr, state->dma_len,
+ pd->unsafe_global_rkey,
+ sess->max_desc);
+ else
+ ret = ibtrs_map_finish_fmr(state, con);
+
+ if (ret == 0) {
+ state->npages = 0;
+ state->dma_len = 0;
+ }
+
+ return ret;
+}
+
+static int ibtrs_map_sg_entry(struct ibtrs_map_state *state,
+ struct ibtrs_clt_con *con, struct scatterlist *sg,
+ int sg_count)
+{
+ struct ibtrs_clt_sess *sess = to_clt_sess(con->c.sess);
+ unsigned int dma_len, len;
+ struct ib_device *ibdev;
+ dma_addr_t dma_addr;
+ int ret;
+
+ ibdev = sess->s.ib_dev->dev;
+ dma_addr = ib_sg_dma_address(ibdev, sg);
+ dma_len = ib_sg_dma_len(ibdev, sg);
+ if (!dma_len)
+ return 0;
+
+ while (dma_len) {
+ unsigned int offset = dma_addr & ~sess->mr_page_mask;
+
+ if (state->npages == sess->max_pages_per_mr ||
+ offset != 0) {
+ ret = ibtrs_finish_fmr_mapping(state, con);
+ if (ret)
+ return ret;
+ }
+
+ len = min_t(unsigned int, dma_len,
+ sess->mr_page_size - offset);
+
+ if (!state->npages)
+ state->base_dma_addr = dma_addr;
+ state->pages[state->npages++] =
+ dma_addr & sess->mr_page_mask;
+ state->dma_len += len;
+ dma_addr += len;
+ dma_len -= len;
+ }
+
+ /*
+ * If the last entry of the MR wasn't a full page, then we need to
+ * close it out and start a new one -- we can only merge at page
+ * boundaries.
+ */
+ ret = 0;
+ if (len != sess->mr_page_size)
+ ret = ibtrs_finish_fmr_mapping(state, con);
+ return ret;
+}
+
+static int ibtrs_map_fr(struct ibtrs_map_state *state,
+ struct ibtrs_clt_con *con,
+ struct scatterlist *sg, int sg_count)
+{
+ unsigned int sg_offset = 0;
+
+ state->sg = sg;
+
+ while (sg_count) {
+ int i, n;
+
+ n = ibtrs_map_finish_fr(state, con, sg_count, &sg_offset);
+ if (unlikely(n < 0))
+ return n;
+
+ sg_count -= n;
+ for (i = 0; i < n; i++)
+ state->sg = sg_next(state->sg);
+ }
+
+ return 0;
+}
+
+static int ibtrs_map_fmr(struct ibtrs_map_state *state,
+ struct ibtrs_clt_con *con,
+ struct scatterlist *sg_first_entry,
+ int sg_first_entry_index, int sg_count)
+{
+ int i, ret;
+ struct scatterlist *sg;
+
+ for (i = sg_first_entry_index, sg = sg_first_entry; i < sg_count;
+ i++, sg = sg_next(sg)) {
+ ret = ibtrs_map_sg_entry(state, con, sg, sg_count);
+ if (ret)
+ return ret;
+ }
+ return 0;
+}
+
+static int ibtrs_map_sg(struct ibtrs_map_state *state,
+ struct ibtrs_clt_con *con,
+ struct ibtrs_clt_io_req *req)
+{
+ struct ibtrs_clt_sess *sess = to_clt_sess(con->c.sess);
+ int ret = 0;
+
+ state->pages = req->map_page;
+ if (sess->fast_reg_mode == IBTRS_FAST_MEM_FR) {
+ state->next_fr = req->fr_list;
+ ret = ibtrs_map_fr(state, con, req->sglist, req->sg_cnt);
+ if (ret)
+ goto out;
+ } else if (sess->fast_reg_mode == IBTRS_FAST_MEM_FMR) {
+ state->next_fmr = req->fmr_list;
+ ret = ibtrs_map_fmr(state, con, req->sglist, 0,
+ req->sg_cnt);
+ if (ret)
+ goto out;
+ ret = ibtrs_finish_fmr_mapping(state, con);
+ if (ret)
+ goto out;
+ }
+
+out:
+ req->nmdesc = state->nmdesc;
+ return ret;
+}
+
+static void ibtrs_clt_inv_rkey_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_LOCAL_INV: %s\n",
+ ib_wc_status_msg(wc->status));
+ ibtrs_rdma_error_recovery(con);
+ }
+}
+
+static struct ib_cqe local_inv_cqe = {
+ .done = ibtrs_clt_inv_rkey_done
+};
+
+static int ibtrs_inv_rkey(struct ibtrs_clt_con *con, u32 rkey)
+{
+ struct ib_send_wr *bad_wr;
+ struct ib_send_wr wr = {
+ .opcode = IB_WR_LOCAL_INV,
+ .wr_cqe = &local_inv_cqe,
+ .next = NULL,
+ .num_sge = 0,
+ .send_flags = 0,
+ .ex.invalidate_rkey = rkey,
+ };
+
+ return ib_post_send(con->c.qp, &wr, &bad_wr);
+}
+
+static void ibtrs_unmap_fast_reg_data(struct ibtrs_clt_con *con,
+ struct ibtrs_clt_io_req *req)
+{
+ struct ibtrs_clt_sess *sess = to_clt_sess(con->c.sess);
+ int i, ret;
+
+ if (sess->fast_reg_mode == IBTRS_FAST_MEM_FR) {
+ struct ibtrs_fr_desc **pfr;
+
+ for (i = req->nmdesc, pfr = req->fr_list; i > 0; i--, pfr++) {
+ ret = ibtrs_inv_rkey(con, (*pfr)->mr->rkey);
+ if (ret < 0) {
+ ibtrs_err(sess,
+ "Invalidating registered RDMA memory for"
+ " rkey %#x failed, err: %d\n",
+ (*pfr)->mr->rkey, ret);
+ }
+ }
+ if (req->nmdesc)
+ ibtrs_fr_pool_put(con->fr_pool, req->fr_list,
+ req->nmdesc);
+ } else {
+ struct ib_pool_fmr **pfmr;
+
+ for (i = req->nmdesc, pfmr = req->fmr_list; i > 0; i--, pfmr++)
+ ib_fmr_pool_unmap(*pfmr);
+ }
+ req->nmdesc = 0;
+}
+
+/*
+ * We have more scatter/gather entries, so use fast_reg_map
+ * trying to merge as many entries as we can.
+ */
+static int ibtrs_fast_reg_map_data(struct ibtrs_clt_con *con,
+ struct ibtrs_sg_desc *desc,
+ struct ibtrs_clt_io_req *req)
+{
+ struct ibtrs_clt_sess *sess = to_clt_sess(con->c.sess);
+ struct ibtrs_map_state state;
+ int ret;
+
+ memset(&state, 0, sizeof(state));
+ state.desc = desc;
+ state.dir = req->dir;
+ ret = ibtrs_map_sg(&state, con, req);
+
+ if (unlikely(ret))
+ goto unmap;
+
+ if (unlikely(state.ndesc <= 0)) {
+ ibtrs_err(sess,
+ "Could not fit S/G list into buffer descriptor %d\n",
+ state.ndesc);
+ ret = -EIO;
+ goto unmap;
+ }
+
+ return state.ndesc;
+unmap:
+ ibtrs_unmap_fast_reg_data(con, req);
+ return ret;
+}
+
+static int ibtrs_post_send_rdma(struct ibtrs_clt_con *con,
+ struct ibtrs_clt_io_req *req,
+ u64 addr, u32 off, u32 imm)
+{
+ struct ibtrs_clt_sess *sess = to_clt_sess(con->c.sess);
+ enum ib_send_flags flags;
+ struct ib_sge list[1];
+
+ 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 */
+ list[0].addr = req->iu->dma_addr;
+ list[0].length = req->sg_size;
+ list[0].lkey = sess->s.ib_dev->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;
+ return ibtrs_iu_post_rdma_write_imm(&con->c, req->iu, list, 1,
+ sess->srv_rdma_buf_rkey,
+ addr + off, imm, flags);
+}
+
+static void ibtrs_set_sge_with_desc(struct ib_sge *list,
+ struct ibtrs_sg_desc *desc)
+{
+ list->addr = le64_to_cpu(desc->addr);
+ list->length = le32_to_cpu(desc->len);
+ list->lkey = le32_to_cpu(desc->key);
+ pr_debug("dma_addr %llu, key %u, dma_len %u\n",
+ list->addr, list->lkey, list->length);
+}
+
+static void ibtrs_set_rdma_desc_last(struct ibtrs_clt_con *con,
+ struct ib_sge *list,
+ struct ibtrs_clt_io_req *req,
+ struct ib_rdma_wr *wr, int offset,
+ struct ibtrs_sg_desc *desc, int m,
+ int n, u64 addr, u32 size, u32 imm)
+{
+ struct ibtrs_clt_sess *sess = to_clt_sess(con->c.sess);
+ enum ib_send_flags flags;
+ int i;
+
+ for (i = m; i < n; i++, desc++)
+ ibtrs_set_sge_with_desc(&list[i], desc);
+
+ list[i].addr = req->iu->dma_addr;
+ list[i].length = size;
+ list[i].lkey = sess->s.ib_dev->lkey;
+
+ wr->wr.wr_cqe = &req->iu->cqe;
+ wr->wr.sg_list = &list[m];
+ wr->wr.num_sge = n - m + 1;
+ wr->remote_addr = addr + offset;
+ wr->rkey = sess->srv_rdma_buf_rkey;
+
+ /*
+ * 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;
+
+ wr->wr.opcode = IB_WR_RDMA_WRITE_WITH_IMM;
+ wr->wr.send_flags = flags;
+ wr->wr.ex.imm_data = cpu_to_be32(imm);
+}
+
+static int ibtrs_post_send_rdma_desc_more(struct ibtrs_clt_con *con,
+ struct ib_sge *list,
+ struct ibtrs_clt_io_req *req,
+ struct ibtrs_sg_desc *desc, int n,
+ u64 addr, u32 size, u32 imm)
+{
+ struct ibtrs_clt_sess *sess = to_clt_sess(con->c.sess);
+ size_t max_sge, num_sge, num_wr;
+ struct ib_send_wr *bad_wr;
+ struct ib_rdma_wr *wrs, *wr;
+ int j = 0, k, offset = 0, len = 0;
+ int m = 0;
+ int ret;
+
+ max_sge = sess->max_sge;
+ num_sge = 1 + n;
+ num_wr = DIV_ROUND_UP(num_sge, max_sge);
+
+ wrs = kcalloc(num_wr, sizeof(*wrs), GFP_ATOMIC);
+ if (!wrs)
+ return -ENOMEM;
+
+ if (num_wr == 1)
+ goto last_one;
+
+ for (; j < num_wr; j++) {
+ wr = &wrs[j];
+ for (k = 0; k < max_sge; k++, desc++) {
+ m = k + j * max_sge;
+ ibtrs_set_sge_with_desc(&list[m], desc);
+ len += le32_to_cpu(desc->len);
+ }
+ wr->wr.wr_cqe = &req->iu->cqe;
+ wr->wr.sg_list = &list[m];
+ wr->wr.num_sge = max_sge;
+ wr->remote_addr = addr + offset;
+ wr->rkey = sess->srv_rdma_buf_rkey;
+
+ offset += len;
+ wr->wr.next = &wrs[j + 1].wr;
+ wr->wr.opcode = IB_WR_RDMA_WRITE;
+ }
+
+last_one:
+ wr = &wrs[j];
+
+ ibtrs_set_rdma_desc_last(con, list, req, wr, offset,
+ desc, m, n, addr, size, imm);
+
+ ret = ib_post_send(con->c.qp, &wrs[0].wr, &bad_wr);
+ if (unlikely(ret))
+ ibtrs_err(sess, "Posting write request to QP failed,"
+ " err: %d\n", ret);
+ kfree(wrs);
+ return ret;
+}
+
+static int ibtrs_post_send_rdma_desc(struct ibtrs_clt_con *con,
+ struct ibtrs_clt_io_req *req,
+ struct ibtrs_sg_desc *desc, int n,
+ u64 addr, u32 size, u32 imm)
+{
+ struct ibtrs_clt_sess *sess = to_clt_sess(con->c.sess);
+ enum ib_send_flags flags;
+ struct ib_sge *list;
+ size_t num_sge;
+ int ret, i;
+
+ num_sge = 1 + n;
+ list = kmalloc_array(num_sge, sizeof(*list), GFP_ATOMIC);
+ if (!list)
+ return -ENOMEM;
+
+ if (num_sge < sess->max_sge) {
+ for (i = 0; i < n; i++, desc++)
+ ibtrs_set_sge_with_desc(&list[i], desc);
+ list[i].addr = req->iu->dma_addr;
+ list[i].length = size;
+ list[i].lkey = sess->s.ib_dev->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;
+ ret = ibtrs_iu_post_rdma_write_imm(&con->c, req->iu, list,
+ num_sge,
+ sess->srv_rdma_buf_rkey,
+ addr, imm, flags);
+ } else {
+ ret = ibtrs_post_send_rdma_desc_more(con, list, req, desc, n,
+ addr, size, imm);
+ }
+
+ kfree(list);
+ return ret;
+}
+
+static int ibtrs_post_send_rdma_more(struct ibtrs_clt_con *con,
+ struct ibtrs_clt_io_req *req,
+ u64 addr, u32 size, u32 imm)
+{
+ struct ibtrs_clt_sess *sess = to_clt_sess(con->c.sess);
+ struct ib_device *ibdev = sess->s.ib_dev->dev;
+ enum ib_send_flags flags;
+ struct scatterlist *sg;
+ struct ib_sge *list;
+ size_t num_sge;
+ int i, ret;
+
+ num_sge = 1 + req->sg_cnt;
+ list = kmalloc_array(num_sge, sizeof(*list), GFP_ATOMIC);
+ if (!list)
+ return -ENOMEM;
+
+ for_each_sg(req->sglist, sg, req->sg_cnt, i) {
+ list[i].addr = ib_sg_dma_address(ibdev, sg);
+ list[i].length = ib_sg_dma_len(ibdev, sg);
+ list[i].lkey = sess->s.ib_dev->lkey;
+ }
+ list[i].addr = req->iu->dma_addr;
+ list[i].length = size;
+ list[i].lkey = sess->s.ib_dev->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;
+ ret = ibtrs_iu_post_rdma_write_imm(&con->c, req->iu, list, num_sge,
+ sess->srv_rdma_buf_rkey,
+ addr, imm, flags);
+ kfree(list);
+
+ return ret;
+}
+
+static inline unsigned long ibtrs_clt_get_raw_ms(void)
+{
+ struct timespec ts;
+
+ getrawmonotonic(&ts);
+
+ return timespec_to_ns(&ts) / NSEC_PER_MSEC;
+}
+
+static void complete_rdma_req(struct ibtrs_clt_io_req *req,
+ int errno, bool notify)
+{
+ struct ibtrs_clt_con *con = req->con;
+ struct ibtrs_clt_sess *sess;
+ enum dma_data_direction dir;
+ struct ibtrs_clt *clt;
+ void *priv;
+
+ 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 > fmr_sg_cnt)
+ ibtrs_unmap_fast_reg_data(req->con, req);
+ if (req->sg_cnt)
+ ib_dma_unmap_sg(sess->s.ib_dev->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,
+ ibtrs_clt_get_raw_ms() -
+ req->start_time);
+ ibtrs_clt_decrease_inflight(&sess->stats);
+
+ req->in_use = false;
+ req->con = NULL;
+ priv = req->priv;
+ dir = req->dir;
+
+ if (notify)
+ req->conf(priv, errno);
+}
+
+static void process_io_rsp(struct ibtrs_clt_sess *sess, u32 msg_id, s16 errno)
+{
+ if (WARN_ON(msg_id >= sess->queue_depth))
+ return;
+
+ complete_rdma_req(&sess->reqs[msg_id], errno, true);
+}
+
+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;
+ 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_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;
+ 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;
+ }
+ ibtrs_from_imm(be32_to_cpu(wc->ex.imm_data),
+ &imm_type, &imm_payload);
+ if (likely(imm_type == IBTRS_IO_RSP_IMM)) {
+ u32 msg_id;
+
+ ibtrs_from_io_rsp_imm(imm_payload, &msg_id, &err);
+ process_io_rsp(sess, msg_id, err);
+ } 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);
+ }
+ break;
+ default:
+ ibtrs_wrn(sess, "Unexpected WC type: %s\n",
+ ib_wc_opcode_str(wc->opcode));
+ return;
+ }
+}
+
+static int post_recv_io(struct ibtrs_clt_con *con)
+{
+ struct ibtrs_clt_sess *sess = to_clt_sess(con->c.sess);
+ int err, i;
+
+ for (i = 0; i < sess->queue_depth; 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)
+{
+ int err, cid;
+
+ for (cid = 0; cid < sess->s.con_num; cid++) {
+ err = post_recv_io(to_clt_con(sess->s.con[cid]));
+ 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); \
+ ibtrs_clt_state_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); \
+ ibtrs_clt_state_unlock(); \
+ }
+
+/**
+ * get_next_path_rr() - Returns path in round-robin fashion.
+ *
+ * Related to @MP_POLICY_RR
+ *
+ * Locks:
+ * ibtrs_clt_state_lock() must be hold.
+ */
+static struct ibtrs_clt_sess *get_next_path_rr(struct path_it *it)
+{
+ struct ibtrs_clt_sess __percpu * __rcu *ppcpu_path, *path;
+ struct ibtrs_clt *clt = it->clt;
+
+ 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_rcu_rr(path, &clt->paths_list,
+ 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:
+ * ibtrs_clt_state_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)
+{
+ 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;
+ copy_from_kvec(req->iu->buf, vec, usr_len);
+ if (sess->stats.enable_rdma_lat)
+ req->start_time = ibtrs_clt_get_raw_ms();
+}
+
+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_write_req(struct ibtrs_clt_io_req *req);
+static int ibtrs_clt_read_req(struct ibtrs_clt_io_req *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,
+ bool failover)
+{
+ struct ibtrs_clt *clt = sess->clt;
+ struct ibtrs_clt_io_req *req;
+ int i;
+
+ if (!sess->reqs)
+ return;
+ for (i = 0; i < sess->queue_depth; ++i) {
+ bool notify;
+ int err = 0;
+
+ req = &sess->reqs[i];
+ if (!req->in_use)
+ continue;
+
+ if (failover)
+ err = ibtrs_clt_failover_req(clt, req);
+
+ notify = (!failover || err);
+ complete_rdma_req(req, -ECONNABORTED, notify);
+ }
+}
+
+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 (sess->fast_reg_mode == IBTRS_FAST_MEM_FR)
+ kfree(req->fr_list);
+ else if (sess->fast_reg_mode == IBTRS_FAST_MEM_FMR)
+ kfree(req->fmr_list);
+ kfree(req->map_page);
+ ibtrs_iu_free(req->iu, DMA_TO_DEVICE,
+ sess->s.ib_dev->dev);
+ }
+ kfree(sess->reqs);
+ sess->reqs = NULL;
+}
+
+static int alloc_sess_reqs(struct ibtrs_clt_sess *sess)
+{
+ struct ibtrs_clt_io_req *req;
+ void *mr_list;
+ int i;
+
+ 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_req_size, GFP_KERNEL,
+ sess->s.ib_dev->dev, DMA_TO_DEVICE,
+ ibtrs_clt_rdma_done);
+ if (unlikely(!req->iu))
+ goto out;
+ mr_list = kmalloc_array(sess->max_pages_per_mr,
+ sizeof(void *), GFP_KERNEL);
+ if (unlikely(!mr_list))
+ goto out;
+ if (sess->fast_reg_mode == IBTRS_FAST_MEM_FR)
+ req->fr_list = mr_list;
+ else if (sess->fast_reg_mode == IBTRS_FAST_MEM_FMR)
+ req->fmr_list = mr_list;
+
+ req->map_page = kmalloc_array(sess->max_pages_per_mr,
+ sizeof(void *), GFP_KERNEL);
+ if (unlikely(!req->map_page))
+ goto out;
+ }
+
+ return 0;
+
+out:
+ free_sess_reqs(sess);
+
+ return -ENOMEM;
+}
+
+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 ibtrs_ib_dev *ib_dev;
+ u64 max_pages_per_mr;
+ int mr_page_shift;
+
+ ib_dev = sess->s.ib_dev;
+ if (ib_dev->dev->alloc_fmr && ib_dev->dev->dealloc_fmr &&
+ ib_dev->dev->map_phys_fmr && ib_dev->dev->unmap_fmr) {
+ sess->fast_reg_mode = IBTRS_FAST_MEM_FMR;
+ ibtrs_info(sess, "Device %s supports FMR\n", ib_dev->dev->name);
+ }
+ if (ib_dev->attrs.device_cap_flags & IB_DEVICE_MEM_MGT_EXTENSIONS &&
+ use_fr) {
+ sess->fast_reg_mode = IBTRS_FAST_MEM_FR;
+ ibtrs_info(sess, "Device %s supports FR\n", ib_dev->dev->name);
+ }
+
+ /*
+ * 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);
+ sess->mr_page_size = 1 << mr_page_shift;
+ sess->max_sge = ib_dev->attrs.max_sge;
+ sess->mr_page_mask = ~((u64)sess->mr_page_size - 1);
+ max_pages_per_mr = ib_dev->attrs.max_mr_size;
+ do_div(max_pages_per_mr, sess->mr_page_size);
+ sess->max_pages_per_mr = min_t(u64, sess->max_pages_per_mr,
+ max_pages_per_mr);
+ if (sess->fast_reg_mode == IBTRS_FAST_MEM_FR) {
+ sess->max_pages_per_mr =
+ min_t(u32, sess->max_pages_per_mr,
+ ib_dev->attrs.max_fast_reg_page_list_len);
+ }
+ sess->mr_max_size = sess->mr_page_size * sess->max_pages_per_mr;
+}
+
+static int alloc_con_fast_pool(struct ibtrs_clt_con *con)
+{
+ struct ibtrs_clt_sess *sess = to_clt_sess(con->c.sess);
+ struct ibtrs_fr_pool *fr_pool;
+ int err = 0;
+
+ if (sess->fast_reg_mode == IBTRS_FAST_MEM_FR) {
+ fr_pool = ibtrs_create_fr_pool(sess->s.ib_dev->dev,
+ sess->s.ib_dev->pd,
+ sess->queue_depth,
+ sess->max_pages_per_mr);
+ if (unlikely(IS_ERR(fr_pool))) {
+ err = PTR_ERR(fr_pool);
+ ibtrs_err(sess, "FR pool allocation failed, err: %d\n",
+ err);
+ return err;
+ }
+ con->fr_pool = fr_pool;
+ }
+
+ return err;
+}
+
+static void free_con_fast_pool(struct ibtrs_clt_con *con)
+{
+ if (con->fr_pool) {
+ ibtrs_destroy_fr_pool(con->fr_pool);
+ con->fr_pool = NULL;
+ }
+}
+
+static int alloc_sess_fast_pool(struct ibtrs_clt_sess *sess)
+{
+ struct ib_fmr_pool_param fmr_param;
+ struct ib_fmr_pool *fmr_pool;
+ int err = 0;
+
+ if (sess->fast_reg_mode == IBTRS_FAST_MEM_FMR) {
+ memset(&fmr_param, 0, sizeof(fmr_param));
+ fmr_param.pool_size = sess->queue_depth *
+ sess->max_pages_per_mr;
+ fmr_param.dirty_watermark = fmr_param.pool_size / 4;
+ fmr_param.cache = 0;
+ fmr_param.max_pages_per_fmr = sess->max_pages_per_mr;
+ fmr_param.page_shift = ilog2(sess->mr_page_size);
+ fmr_param.access = (IB_ACCESS_LOCAL_WRITE |
+ IB_ACCESS_REMOTE_WRITE);
+
+ fmr_pool = ib_create_fmr_pool(sess->s.ib_dev->pd, &fmr_param);
+ if (unlikely(IS_ERR(fmr_pool))) {
+ err = PTR_ERR(fmr_pool);
+ ibtrs_err(sess, "FMR pool allocation failed, err: %d\n",
+ err);
+ return err;
+ }
+ sess->fmr_pool = fmr_pool;
+ }
+
+ return err;
+}
+
+static void free_sess_fast_pool(struct ibtrs_clt_sess *sess)
+{
+ if (sess->fmr_pool) {
+ ib_destroy_fmr_pool(sess->fmr_pool);
+ sess->fmr_pool = NULL;
+ }
+}
+
+static int alloc_sess_io_bufs(struct ibtrs_clt_sess *sess)
+{
+ int ret;
+
+ ret = alloc_sess_reqs(sess);
+ if (unlikely(ret)) {
+ ibtrs_err(sess, "alloc_sess_reqs(), err: %d\n", ret);
+ return ret;
+ }
+ ret = alloc_sess_fast_pool(sess);
+ if (unlikely(ret)) {
+ ibtrs_err(sess, "alloc_sess_fast_pool(), err: %d\n", ret);
+ goto free_reqs;
+ }
+
+ return 0;
+
+free_reqs:
+ free_sess_reqs(sess);
+
+ return ret;
+}
+
+static void free_sess_io_bufs(struct ibtrs_clt_sess *sess)
+{
+ free_sess_reqs(sess);
+ free_sess_fast_pool(sess);
+}
+
+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->srv_rdma_addr);
+ 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) {
+ cq_size = SERVICE_CON_QUEUE_DEPTH;
+ /* + 2 for drain and heartbeat */
+ wr_queue_size = SERVICE_CON_QUEUE_DEPTH + 2;
+ /* We must be the first here */
+ if (WARN_ON(sess->s.ib_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.ib_dev = ibtrs_ib_dev_find_get(con->c.cm_id);
+ if (unlikely(!sess->s.ib_dev)) {
+ ibtrs_wrn(sess, "ibtrs_ib_dev_find_get(): no memory\n");
+ return -ENOMEM;
+ }
+ sess->s.ib_dev_ref = 1;
+ query_fast_reg_mode(sess);
+ } else {
+ int num_wr;
+
+ /*
+ * 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.ib_dev))
+ return -EINVAL;
+ if (WARN_ON(!sess->queue_depth))
+ return -EINVAL;
+
+ /* Shared between connections */
+ sess->s.ib_dev_ref++;
+ cq_size = sess->queue_depth;
+ num_wr = DIV_ROUND_UP(sess->max_pages_per_mr, sess->max_sge);
+ wr_queue_size = sess->s.ib_dev->attrs.max_qp_wr;
+ wr_queue_size = min_t(int, wr_queue_size,
+ sess->queue_depth * num_wr *
+ (use_fr ? 3 : 2) + 1);
+ }
+ cq_vector = con->cpu % sess->s.ib_dev->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;
+
+ if (con->c.cid) {
+ err = alloc_con_fast_pool(con);
+ if (unlikely(err))
+ ibtrs_cq_qp_destroy(&con->c);
+ }
+
+ 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 (con->c.cid != 0)
+ free_con_fast_pool(con);
+ if (sess->s.ib_dev_ref && !--sess->s.ib_dev_ref) {
+ ibtrs_ib_dev_put(sess->s.ib_dev);
+ sess->s.ib_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 ibtrs_clt_rdma_cm_handler(struct rdma_cm_id *cm_id,
+ struct rdma_cm_event *ev);
+
+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,
+ bool failover)
+{
+ 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++) {
+ con = to_clt_con(sess->s.con[cid]);
+ if (!con)
+ break;
+
+ stop_cm(con);
+ }
+ fail_all_outstanding_reqs(sess, failover);
+ free_sess_io_bufs(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++) {
+ con = to_clt_con(sess->s.con[cid]);
+ if (!con)
+ break;
+
+ destroy_con_cq_qp(con);
+ destroy_cm(con);
+ destroy_con(con);
+ }
+}
+
+static void ibtrs_clt_remove_path_from_arr(struct ibtrs_clt_sess *sess)
+{
+ struct ibtrs_clt *clt = sess->clt;
+ struct ibtrs_clt_sess *next;
+ int cpu;
+
+ mutex_lock(&clt->paths_mutex);
+ list_del_rcu(&sess->s.entry);
+
+ /* Make sure everybody observes path removal. */
+ synchronize_rcu();
+
+ /*
+ * 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--;
+
+ next = list_next_or_null_rcu_rr(sess, &clt->paths_list, 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 **ppcpu_path;
+
+ ppcpu_path = per_cpu_ptr(clt->pcpu_path, cpu);
+ if (*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 override it.
+ */
+ cmpxchg(ppcpu_path, sess, next);
+ }
+ mutex_unlock(&clt->paths_mutex);
+}
+
+static inline bool __ibtrs_clt_path_exists(struct ibtrs_clt *clt,
+ struct ibtrs_addr *addr)
+{
+ struct ibtrs_clt_sess *sess;
+
+ list_for_each_entry(sess, &clt->paths_list, s.entry)
+ if (!sockaddr_cmp((struct sockaddr *)&sess->s.dst_addr,
+ addr->dst))
+ return true;
+
+ return false;
+}
+
+static bool ibtrs_clt_path_exists(struct ibtrs_clt *clt,
+ struct ibtrs_addr *addr)
+{
+ bool res;
+
+ mutex_lock(&clt->paths_mutex);
+ res = __ibtrs_clt_path_exists(clt, addr);
+ mutex_unlock(&clt->paths_mutex);
+
+ return res;
+}
+
+static int ibtrs_clt_add_path_to_arr(struct ibtrs_clt_sess *sess,
+ struct ibtrs_addr *addr)
+{
+ struct ibtrs_clt *clt = sess->clt;
+ int err = 0;
+
+ mutex_lock(&clt->paths_mutex);
+ if (!__ibtrs_clt_path_exists(clt, addr)) {
+ list_add_tail_rcu(&sess->s.entry, &clt->paths_list);
+ clt->paths_num++;
+ } else
+ err = -EEXIST;
+ mutex_unlock(&clt->paths_mutex);
+
+ return err;
+}
+
+static void ibtrs_clt_close_work(struct work_struct *work)
+{
+ struct ibtrs_clt_sess *sess;
+ /*
+ * Always try to do a failover, if only single path remains,
+ * all requests will be completed with error.
+ */
+ bool failover = true;
+
+ sess = container_of(work, struct ibtrs_clt_sess, close_work);
+
+ cancel_delayed_work_sync(&sess->reconnect_dwork);
+ ibtrs_clt_stop_and_destroy_conns(sess, failover);
+ /*
+ * 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;
+ }
+ }
+ /* Allocate all session related buffers */
+ err = alloc_sess_io_bufs(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(&param, 0, sizeof(param));
+ param.retry_count = retry_count;
+ 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_VERSION);
+ 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, &param);
+ 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);
+ 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");
+ return -ECONNRESET;
+ }
+ if (unlikely(le16_to_cpu(msg->magic) != IBTRS_MAGIC)) {
+ ibtrs_err(sess, "Invalid IBTRS magic");
+ return -ECONNRESET;
+ }
+ version = le16_to_cpu(msg->version);
+ if (unlikely(version >> 8 != IBTRS_VER_MAJOR)) {
+ ibtrs_err(sess, "Unsupported major IBTRS version: %d",
+ version);
+ return -ECONNRESET;
+ }
+ errno = le16_to_cpu(msg->errno);
+ if (unlikely(errno)) {
+ ibtrs_err(sess, "Invalid IBTRS message: errno %d",
+ 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->srv_rdma_addr || sess->queue_depth < queue_depth) {
+ kfree(sess->srv_rdma_addr);
+ sess->srv_rdma_addr =
+ kcalloc(queue_depth,
+ sizeof(*sess->srv_rdma_addr),
+ GFP_KERNEL);
+ if (unlikely(!sess->srv_rdma_addr)) {
+ ibtrs_err(sess, "Failed to allocate "
+ "queue_depth=%d\n", queue_depth);
+ return -ENOMEM;
+ }
+ }
+ sess->queue_depth = queue_depth;
+ sess->srv_rdma_buf_rkey = le32_to_cpu(msg->rkey);
+ sess->max_req_size = le32_to_cpu(msg->max_req_size);
+ sess->max_io_size = le32_to_cpu(msg->max_io_size);
+ sess->chunk_size = sess->max_io_size + sess->max_req_size;
+ sess->max_desc = sess->max_req_size;
+ sess->max_desc -= sizeof(u32) + sizeof(u32) + IO_MSG_SIZE;
+ sess->max_desc /= sizeof(struct ibtrs_sg_desc);
+
+ /*
+ * Global queue depth and is always a minimum. If while a
+ * reconnection server sends us a value a bit higher -
+ * client does not care and uses cached minimum.
+ */
+ ibtrs_clt_set_min_queue_depth(sess->clt, sess->queue_depth);
+ ibtrs_clt_set_min_io_size(sess->clt, sess->max_io_size);
+ }
+
+ 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.ib_dev->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 addr_num;
+ int i;
+
+ addr_num = le16_to_cpu(msg->addr_num);
+ /*
+ * Check if IB immediate data size is enough to hold the mem_id and
+ * the offset inside the memory chunk.
+ */
+ if (unlikely(ilog2(addr_num - 1) + ilog2(sess->chunk_size - 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,
+ addr_num, sess->chunk_size);
+ return -EINVAL;
+ }
+ if (unlikely(addr_num > sess->queue_depth)) {
+ ibtrs_err(sess, "Incorrect addr_num=%d\n", addr_num);
+ return -EINVAL;
+ }
+ for (i = 0; i < msg->addr_num; i++)
+ sess->srv_rdma_addr[i] = le64_to_cpu(msg->addr[i]);
+
+ 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;
+ }
+ 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",
+ le32_to_cpu(msg->type));
+ goto out;
+ }
+ rx_sz = sizeof(*msg);
+ rx_sz += sizeof(msg->addr[0]) * le16_to_cpu(msg->addr_num);
+ 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.ib_dev->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.ib_dev->dev, DMA_TO_DEVICE,
+ ibtrs_clt_info_req_done);
+ rx_iu = ibtrs_iu_alloc(0, rx_sz, GFP_KERNEL, sess->s.ib_dev->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));
+
+ /* Send info request */
+ err = ibtrs_iu_post_send(&usr_con->c, tx_iu, sizeof(*msg));
+ 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.ib_dev->dev);
+ if (rx_iu)
+ ibtrs_iu_free(rx_iu, DMA_FROM_DEVICE, sess->s.ib_dev->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, true);
+ 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 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);
+
+ err = ibtrs_clt_create_sysfs_root_folders(clt);
+ if (unlikely(err)) {
+ free_percpu(clt->pcpu_path);
+ kfree(clt);
+ return ERR_PTR(err);
+ }
+
+ return clt;
+}
+
+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);
+ 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_clt_rdma_write_desc(struct ibtrs_clt_con *con,
+ struct ibtrs_clt_io_req *req, u64 buf,
+ size_t u_msg_len, u32 imm,
+ struct ibtrs_msg_rdma_write *msg)
+{
+ struct ibtrs_clt_sess *sess = to_clt_sess(con->c.sess);
+ struct ibtrs_sg_desc *desc;
+ int ret;
+
+ desc = kmalloc_array(sess->max_pages_per_mr, sizeof(*desc), GFP_ATOMIC);
+ if (unlikely(!desc))
+ return -ENOMEM;
+
+ ret = ibtrs_fast_reg_map_data(con, desc, req);
+ if (unlikely(ret < 0)) {
+ ibtrs_err_rl(sess,
+ "Write request failed, fast reg. data mapping"
+ " failed, err: %d\n", ret);
+ kfree(desc);
+ return ret;
+ }
+ ret = ibtrs_post_send_rdma_desc(con, req, desc, ret, buf,
+ u_msg_len + sizeof(*msg), imm);
+ if (unlikely(ret)) {
+ ibtrs_err(sess, "Write request failed, posting work"
+ " request failed, err: %d\n", ret);
+ ibtrs_unmap_fast_reg_data(con, req);
+ }
+ kfree(desc);
+ return ret;
+}
+
+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;
+
+ int ret, count = 0;
+ u32 imm, buf_id;
+ u64 buf;
+
+ 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.ib_dev->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;
+ buf = sess->srv_rdma_addr[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);
+
+ if (count > fmr_sg_cnt)
+ ret = ibtrs_clt_rdma_write_desc(req->con, req, buf,
+ req->usr_len, imm, msg);
+ else
+ ret = ibtrs_post_send_rdma_more(req->con, req, buf,
+ 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.ib_dev->dev, req->sglist,
+ req->sg_cnt, req->dir);
+ }
+
+ return ret;
+}
+
+int ibtrs_clt_write(struct ibtrs_clt *clt, ibtrs_conf_fn *conf,
+ 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;
+
+ int err = -ECONNABORTED;
+ struct path_it it;
+ size_t usr_len;
+
+ usr_len = kvec_length(vec, nr);
+ do_each_path(sess, clt, &it) {
+ if (unlikely(sess->state != IBTRS_CLT_CONNECTED))
+ continue;
+
+ if (unlikely(usr_len > IO_MSG_SIZE)) {
+ ibtrs_wrn_rl(sess, "Write request failed, user message"
+ " size is %zu B big, max size is %d B\n",
+ usr_len, IO_MSG_SIZE);
+ err = -EMSGSIZE;
+ break;
+ }
+ req = ibtrs_clt_get_req(sess, conf, tag, priv, vec, usr_len,
+ sg, sg_cnt, data_len, DMA_TO_DEVICE);
+ err = ibtrs_clt_write_req(req);
+ if (unlikely(err)) {
+ req->in_use = false;
+ continue;
+ }
+ /* Success path */
+ break;
+ } while_each_path(&it);
+
+ return err;
+}
+
+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 *ibdev;
+ struct scatterlist *sg;
+
+ int i, ret, count = 0;
+ u32 imm, buf_id;
+
+ const size_t tsize = sizeof(*msg) + req->data_len + req->usr_len;
+
+ ibdev = sess->s.ib_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(ibdev->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->sg_cnt = cpu_to_le32(count);
+ msg->usr_len = cpu_to_le16(req->usr_len);
+
+ if (count > fmr_sg_cnt) {
+ ret = ibtrs_fast_reg_map_data(req->con, msg->desc, req);
+ if (ret < 0) {
+ ibtrs_err_rl(sess,
+ "Read request failed, failed to map "
+ " fast reg. data, err: %d\n", ret);
+ ib_dma_unmap_sg(ibdev->dev, req->sglist, req->sg_cnt,
+ req->dir);
+ return ret;
+ }
+ msg->sg_cnt = cpu_to_le32(ret);
+ } else {
+ for_each_sg(req->sglist, sg, req->sg_cnt, i) {
+ msg->desc[i].addr =
+ cpu_to_le64(ib_sg_dma_address(ibdev->dev, sg));
+ msg->desc[i].key =
+ cpu_to_le32(ibdev->rkey);
+ msg->desc[i].len =
+ cpu_to_le32(ib_sg_dma_len(ibdev->dev, sg));
+ }
+ req->nmdesc = 0;
+ }
+ /*
+ * 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 += le32_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->srv_rdma_addr[buf_id],
+ req->data_len, imm);
+ if (unlikely(ret)) {
+ ibtrs_err(sess, "Read request failed: %d\n", ret);
+ ibtrs_clt_decrease_inflight(&sess->stats);
+ if (unlikely(count > fmr_sg_cnt))
+ ibtrs_unmap_fast_reg_data(req->con, req);
+ if (req->sg_cnt)
+ ib_dma_unmap_sg(ibdev->dev, req->sglist,
+ req->sg_cnt, req->dir);
+ }
+
+ return ret;
+}
+
+int ibtrs_clt_read(struct ibtrs_clt *clt, ibtrs_conf_fn *conf,
+ 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;
+
+ int err = -ECONNABORTED;
+ struct path_it it;
+ size_t usr_len;
+
+ usr_len = kvec_length(vec, nr);
+ do_each_path(sess, clt, &it) {
+ if (unlikely(sess->state != IBTRS_CLT_CONNECTED))
+ continue;
+
+ if (unlikely(usr_len > IO_MSG_SIZE ||
+ sizeof(struct ibtrs_msg_rdma_read) +
+ sg_cnt * sizeof(struct ibtrs_sg_desc) >
+ sess->max_req_size)) {
+ ibtrs_wrn_rl(sess, "Read request failed, user message"
+ " size is %zu B big, max size is %d B\n",
+ usr_len, IO_MSG_SIZE);
+ err = -EMSGSIZE;
+ break;
+ }
+ req = ibtrs_clt_get_req(sess, conf, tag, priv, vec, usr_len,
+ sg, sg_cnt, data_len, DMA_FROM_DEVICE);
+ err = ibtrs_clt_read_req(req);
+ if (unlikely(err)) {
+ req->in_use = false;
+ continue;
+ }
+ /* Success path */
+ break;
+ } while_each_path(&it);
+
+ return err;
+}
+
+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 len, struct scatterlist *sg,
+ unsigned int sg_len)
+{
+ if (dir == READ)
+ return ibtrs_clt_read(clt, conf, tag, priv, vec, nr, len, sg,
+ sg_len);
+ else
+ return ibtrs_clt_write(clt, conf, tag, priv, vec, nr, len, sg,
+ sg_len);
+}
+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;
+ 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;
+
+ if (ibtrs_clt_path_exists(clt, addr))
+ return -EEXIST;
+
+ 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.
+ */
+ err = ibtrs_clt_add_path_to_arr(sess, addr);
+ if (unlikely(err))
+ goto free_sess;
+
+ 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:
+ free_sess(sess);
+
+ return err;
+}
+
+static int check_module_params(void)
+{
+ if (fmr_sg_cnt > MAX_SEGMENTS || fmr_sg_cnt < 0) {
+ pr_err("invalid fmr_sg_cnt values\n");
+ return -EINVAL;
+ }
+ if (nr_cons_per_session == 0)
+ nr_cons_per_session = min_t(unsigned int, nr_cpu_ids, U16_MAX);
+
+ return 0;
+}
+
+static int __init ibtrs_client_init(void)
+{
+ int err;
+
+ pr_info("Loading module %s, version: %s "
+ "(use_fr: %d, retry_count: %d, "
+ "fmr_sg_cnt: %d)\n",
+ KBUILD_MODNAME, IBTRS_VER_STRING,
+ use_fr, retry_count, fmr_sg_cnt);
+ err = check_module_params();
+ if (err) {
+ pr_err("Failed to load module, invalid module parameters,"
+ " err: %d\n", err);
+ return err;
+ }
+ ibtrs_wq = alloc_workqueue("ibtrs_client_wq", WQ_MEM_RECLAIM, 0);
+ if (!ibtrs_wq) {
+ pr_err("Failed to load module, alloc ibtrs_client_wq failed\n");
+ return -ENOMEM;
+ }
+ err = ibtrs_clt_create_sysfs_module_files();
+ if (err) {
+ pr_err("Failed to load module, can't create sysfs files,"
+ " err: %d\n", err);
+ goto out_ibtrs_wq;
+ }
+
+ return 0;
+
+out_ibtrs_wq:
+ destroy_workqueue(ibtrs_wq);
+
+ return err;
+}
+
+static void __exit ibtrs_client_exit(void)
+{
+ ibtrs_clt_destroy_sysfs_module_files();
+ destroy_workqueue(ibtrs_wq);
+}
+
+module_init(ibtrs_client_init);
+module_exit(ibtrs_client_exit);
--
2.13.1