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linux_dsm_epyc7002/drivers/infiniband/ulp/rtrs/rtrs-clt.c
Jack Wang 03ed5a8cda RDMA/rtrs: remove WQ_MEM_RECLAIM for rtrs_wq 
lockdep triggers a warning from time to time when running a regression
test:

 rnbd_client L685: </dev/nullb0@bla> Device disconnected.
 rnbd_client L1756: Unloading module

 workqueue: WQ_MEM_RECLAIM rtrs_client_wq:rtrs_clt_reconnect_work [rtrs_client] is flushing !WQ_MEM_RECLAIM ib_addr:process_one_req [ib_core]
 WARNING: CPU: 2 PID: 18824 at kernel/workqueue.c:2517 check_flush_dependency+0xad/0x130

The root cause is workqueue core expect flushing should not be done for a
!WQ_MEM_RECLAIM wq from a WQ_MEM_RECLAIM workqueue.

In above case ib_addr workqueue without WQ_MEM_RECLAIM, but rtrs_wq
WQ_MEM_RECLAIM.

To avoid the warning, remove the WQ_MEM_RECLAIM flag.

Fixes: 9cb8374804 ("RDMA/rtrs: server: main functionality")
Fixes: 6a98d71dae ("RDMA/rtrs: client: main functionality")
Link: https://lore.kernel.org/r/20200724111508.15734-4-haris.iqbal@cloud.ionos.com
Signed-off-by: Jack Wang <jinpu.wang@cloud.ionos.com>
Signed-off-by: Md Haris Iqbal <haris.iqbal@cloud.ionos.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2020-07-29 14:26:53 -03:00

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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* RDMA Transport Layer
*
* Copyright (c) 2014 - 2018 ProfitBricks GmbH. All rights reserved.
* Copyright (c) 2018 - 2019 1&1 IONOS Cloud GmbH. All rights reserved.
* Copyright (c) 2019 - 2020 1&1 IONOS SE. All rights reserved.
*/
#undef pr_fmt
#define pr_fmt(fmt) KBUILD_MODNAME " L" __stringify(__LINE__) ": " fmt
#include <linux/module.h>
#include <linux/rculist.h>
#include <linux/random.h>
#include "rtrs-clt.h"
#include "rtrs-log.h"
#define RTRS_CONNECT_TIMEOUT_MS 30000
/*
* Wait a bit before trying to reconnect after a failure
* in order to give server time to finish clean up which
* leads to "false positives" failed reconnect attempts
*/
#define RTRS_RECONNECT_BACKOFF 1000
/*
* Wait for additional random time between 0 and 8 seconds
* before starting to reconnect to avoid clients reconnecting
* all at once in case of a major network outage
*/
#define RTRS_RECONNECT_SEED 8
MODULE_DESCRIPTION("RDMA Transport Client");
MODULE_LICENSE("GPL");
static const struct rtrs_rdma_dev_pd_ops dev_pd_ops;
static struct rtrs_rdma_dev_pd dev_pd = {
.ops = &dev_pd_ops
};
static struct workqueue_struct *rtrs_wq;
static struct class *rtrs_clt_dev_class;
static inline bool rtrs_clt_is_connected(const struct rtrs_clt *clt)
{
struct rtrs_clt_sess *sess;
bool connected = false;
rcu_read_lock();
list_for_each_entry_rcu(sess, &clt->paths_list, s.entry)
connected |= READ_ONCE(sess->state) == RTRS_CLT_CONNECTED;
rcu_read_unlock();
return connected;
}
static struct rtrs_permit *
__rtrs_get_permit(struct rtrs_clt *clt, enum rtrs_clt_con_type con_type)
{
size_t max_depth = clt->queue_depth;
struct rtrs_permit *permit;
int bit;
/*
* Adapted from null_blk get_tag(). Callers from different cpus may
* grab the same bit, since find_first_zero_bit is not atomic.
* But then the test_and_set_bit_lock will fail for all the
* callers but one, so that they will loop again.
* This way an explicit spinlock is not required.
*/
do {
bit = find_first_zero_bit(clt->permits_map, max_depth);
if (unlikely(bit >= max_depth))
return NULL;
} while (unlikely(test_and_set_bit_lock(bit, clt->permits_map)));
permit = get_permit(clt, bit);
WARN_ON(permit->mem_id != bit);
permit->cpu_id = raw_smp_processor_id();
permit->con_type = con_type;
return permit;
}
static inline void __rtrs_put_permit(struct rtrs_clt *clt,
struct rtrs_permit *permit)
{
clear_bit_unlock(permit->mem_id, clt->permits_map);
}
/**
* rtrs_clt_get_permit() - allocates permit for future RDMA operation
* @clt: Current session
* @con_type: Type of connection to use with the permit
* @can_wait: Wait type
*
* Description:
* Allocates permit for the following RDMA operation. Permit is used
* to preallocate all resources and to propagate memory pressure
* up earlier.
*
* Context:
* Can sleep if @wait == RTRS_TAG_WAIT
*/
struct rtrs_permit *rtrs_clt_get_permit(struct rtrs_clt *clt,
enum rtrs_clt_con_type con_type,
int can_wait)
{
struct rtrs_permit *permit;
DEFINE_WAIT(wait);
permit = __rtrs_get_permit(clt, con_type);
if (likely(permit) || !can_wait)
return permit;
do {
prepare_to_wait(&clt->permits_wait, &wait,
TASK_UNINTERRUPTIBLE);
permit = __rtrs_get_permit(clt, con_type);
if (likely(permit))
break;
io_schedule();
} while (1);
finish_wait(&clt->permits_wait, &wait);
return permit;
}
EXPORT_SYMBOL(rtrs_clt_get_permit);
/**
* rtrs_clt_put_permit() - puts allocated permit
* @clt: Current session
* @permit: Permit to be freed
*
* Context:
* Does not matter
*/
void rtrs_clt_put_permit(struct rtrs_clt *clt, struct rtrs_permit *permit)
{
if (WARN_ON(!test_bit(permit->mem_id, clt->permits_map)))
return;
__rtrs_put_permit(clt, permit);
/*
* rtrs_clt_get_permit() adds itself to the &clt->permits_wait list
* before calling schedule(). So if rtrs_clt_get_permit() is sleeping
* it must have added itself to &clt->permits_wait before
* __rtrs_put_permit() finished.
* Hence it is safe to guard wake_up() with a waitqueue_active() test.
*/
if (waitqueue_active(&clt->permits_wait))
wake_up(&clt->permits_wait);
}
EXPORT_SYMBOL(rtrs_clt_put_permit);
void *rtrs_permit_to_pdu(struct rtrs_permit *permit)
{
return permit + 1;
}
EXPORT_SYMBOL(rtrs_permit_to_pdu);
/**
* rtrs_permit_to_clt_con() - returns RDMA connection pointer by the permit
* @sess: client session pointer
* @permit: permit for the allocation of the RDMA buffer
* Note:
* IO connection starts from 1.
* 0 connection is for user messages.
*/
static
struct rtrs_clt_con *rtrs_permit_to_clt_con(struct rtrs_clt_sess *sess,
struct rtrs_permit *permit)
{
int id = 0;
if (likely(permit->con_type == RTRS_IO_CON))
id = (permit->cpu_id % (sess->s.con_num - 1)) + 1;
return to_clt_con(sess->s.con[id]);
}
/**
* __rtrs_clt_change_state() - change the session state through session state
* machine.
*
* @sess: client session to change the state of.
* @new_state: state to change to.
*
* returns true if successful, false if the requested state can not be set.
*
* Locks:
* state_wq lock must be hold.
*/
static bool __rtrs_clt_change_state(struct rtrs_clt_sess *sess,
enum rtrs_clt_state new_state)
{
enum rtrs_clt_state old_state;
bool changed = false;
lockdep_assert_held(&sess->state_wq.lock);
old_state = sess->state;
switch (new_state) {
case RTRS_CLT_CONNECTING:
switch (old_state) {
case RTRS_CLT_RECONNECTING:
changed = true;
fallthrough;
default:
break;
}
break;
case RTRS_CLT_RECONNECTING:
switch (old_state) {
case RTRS_CLT_CONNECTED:
case RTRS_CLT_CONNECTING_ERR:
case RTRS_CLT_CLOSED:
changed = true;
fallthrough;
default:
break;
}
break;
case RTRS_CLT_CONNECTED:
switch (old_state) {
case RTRS_CLT_CONNECTING:
changed = true;
fallthrough;
default:
break;
}
break;
case RTRS_CLT_CONNECTING_ERR:
switch (old_state) {
case RTRS_CLT_CONNECTING:
changed = true;
fallthrough;
default:
break;
}
break;
case RTRS_CLT_CLOSING:
switch (old_state) {
case RTRS_CLT_CONNECTING:
case RTRS_CLT_CONNECTING_ERR:
case RTRS_CLT_RECONNECTING:
case RTRS_CLT_CONNECTED:
changed = true;
fallthrough;
default:
break;
}
break;
case RTRS_CLT_CLOSED:
switch (old_state) {
case RTRS_CLT_CLOSING:
changed = true;
fallthrough;
default:
break;
}
break;
case RTRS_CLT_DEAD:
switch (old_state) {
case RTRS_CLT_CLOSED:
changed = true;
fallthrough;
default:
break;
}
break;
default:
break;
}
if (changed) {
sess->state = new_state;
wake_up_locked(&sess->state_wq);
}
return changed;
}
static bool rtrs_clt_change_state_from_to(struct rtrs_clt_sess *sess,
enum rtrs_clt_state old_state,
enum rtrs_clt_state new_state)
{
bool changed = false;
spin_lock_irq(&sess->state_wq.lock);
if (sess->state == old_state)
changed = __rtrs_clt_change_state(sess, new_state);
spin_unlock_irq(&sess->state_wq.lock);
return changed;
}
static void rtrs_rdma_error_recovery(struct rtrs_clt_con *con)
{
struct rtrs_clt_sess *sess = to_clt_sess(con->c.sess);
if (rtrs_clt_change_state_from_to(sess,
RTRS_CLT_CONNECTED,
RTRS_CLT_RECONNECTING)) {
struct rtrs_clt *clt = sess->clt;
unsigned int delay_ms;
/*
* Normal scenario, reconnect if we were successfully connected
*/
delay_ms = clt->reconnect_delay_sec * 1000;
queue_delayed_work(rtrs_wq, &sess->reconnect_dwork,
msecs_to_jiffies(delay_ms +
prandom_u32() % RTRS_RECONNECT_SEED));
} else {
/*
* Error can happen just on establishing new connection,
* so notify waiter with error state, waiter is responsible
* for cleaning the rest and reconnect if needed.
*/
rtrs_clt_change_state_from_to(sess,
RTRS_CLT_CONNECTING,
RTRS_CLT_CONNECTING_ERR);
}
}
static void rtrs_clt_fast_reg_done(struct ib_cq *cq, struct ib_wc *wc)
{
struct rtrs_clt_con *con = cq->cq_context;
if (unlikely(wc->status != IB_WC_SUCCESS)) {
rtrs_err(con->c.sess, "Failed IB_WR_REG_MR: %s\n",
ib_wc_status_msg(wc->status));
rtrs_rdma_error_recovery(con);
}
}
static struct ib_cqe fast_reg_cqe = {
.done = rtrs_clt_fast_reg_done
};
static void complete_rdma_req(struct rtrs_clt_io_req *req, int errno,
bool notify, bool can_wait);
static void rtrs_clt_inv_rkey_done(struct ib_cq *cq, struct ib_wc *wc)
{
struct rtrs_clt_io_req *req =
container_of(wc->wr_cqe, typeof(*req), inv_cqe);
struct rtrs_clt_con *con = cq->cq_context;
if (unlikely(wc->status != IB_WC_SUCCESS)) {
rtrs_err(con->c.sess, "Failed IB_WR_LOCAL_INV: %s\n",
ib_wc_status_msg(wc->status));
rtrs_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 rtrs_inv_rkey(struct rtrs_clt_io_req *req)
{
struct rtrs_clt_con *con = req->con;
struct ib_send_wr wr = {
.opcode = IB_WR_LOCAL_INV,
.wr_cqe = &req->inv_cqe,
.send_flags = IB_SEND_SIGNALED,
.ex.invalidate_rkey = req->mr->rkey,
};
req->inv_cqe.done = rtrs_clt_inv_rkey_done;
return ib_post_send(con->c.qp, &wr, NULL);
}
static void complete_rdma_req(struct rtrs_clt_io_req *req, int errno,
bool notify, bool can_wait)
{
struct rtrs_clt_con *con = req->con;
struct rtrs_clt_sess *sess;
int err;
if (WARN_ON(!req->in_use))
return;
if (WARN_ON(!req->con))
return;
sess = to_clt_sess(con->c.sess);
if (req->sg_cnt) {
if (unlikely(req->dir == DMA_FROM_DEVICE && req->need_inv)) {
/*
* We are here to invalidate read requests
* ourselves. In normal scenario server should
* send INV for all read requests, but
* we are here, thus two things could happen:
*
* 1. this is failover, when errno != 0
* and can_wait == 1,
*
* 2. something totally bad happened and
* server forgot to send INV, so we
* should do that ourselves.
*/
if (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 = rtrs_inv_rkey(req);
if (unlikely(err)) {
rtrs_err(con->c.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->clt->mp_policy == MP_POLICY_MIN_INFLIGHT)
atomic_dec(&sess->stats->inflight);
req->in_use = false;
req->con = NULL;
if (notify)
req->conf(req->priv, errno);
}
static int rtrs_post_send_rdma(struct rtrs_clt_con *con,
struct rtrs_clt_io_req *req,
struct rtrs_rbuf *rbuf, u32 off,
u32 imm, struct ib_send_wr *wr)
{
struct rtrs_clt_sess *sess = to_clt_sess(con->c.sess);
enum ib_send_flags flags;
struct ib_sge sge;
if (unlikely(!req->sg_size)) {
rtrs_wrn(con->c.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 rtrs_iu_post_rdma_write_imm(&con->c, req->iu, &sge, 1,
rbuf->rkey, rbuf->addr + off,
imm, flags, wr);
}
static void process_io_rsp(struct rtrs_clt_sess *sess, u32 msg_id,
s16 errno, bool w_inval)
{
struct rtrs_clt_io_req *req;
if (WARN_ON(msg_id >= sess->queue_depth))
return;
req = &sess->reqs[msg_id];
/* Drop need_inv if server responded with send with invalidation */
req->need_inv &= !w_inval;
complete_rdma_req(req, errno, true, false);
}
static void rtrs_clt_recv_done(struct rtrs_clt_con *con, struct ib_wc *wc)
{
struct rtrs_iu *iu;
int err;
struct rtrs_clt_sess *sess = to_clt_sess(con->c.sess);
WARN_ON(sess->flags != RTRS_MSG_NEW_RKEY_F);
iu = container_of(wc->wr_cqe, struct rtrs_iu,
cqe);
err = rtrs_iu_post_recv(&con->c, iu);
if (unlikely(err)) {
rtrs_err(con->c.sess, "post iu failed %d\n", err);
rtrs_rdma_error_recovery(con);
}
}
static void rtrs_clt_rkey_rsp_done(struct rtrs_clt_con *con, struct ib_wc *wc)
{
struct rtrs_clt_sess *sess = to_clt_sess(con->c.sess);
struct rtrs_msg_rkey_rsp *msg;
u32 imm_type, imm_payload;
bool w_inval = false;
struct rtrs_iu *iu;
u32 buf_id;
int err;
WARN_ON(sess->flags != RTRS_MSG_NEW_RKEY_F);
iu = container_of(wc->wr_cqe, struct rtrs_iu, cqe);
if (unlikely(wc->byte_len < sizeof(*msg))) {
rtrs_err(con->c.sess, "rkey 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) != RTRS_MSG_RKEY_RSP)) {
rtrs_err(sess->clt, "rkey response is malformed: type %d\n",
le16_to_cpu(msg->type));
goto out;
}
buf_id = le16_to_cpu(msg->buf_id);
if (WARN_ON(buf_id >= sess->queue_depth))
goto out;
rtrs_from_imm(be32_to_cpu(wc->ex.imm_data), &imm_type, &imm_payload);
if (likely(imm_type == RTRS_IO_RSP_IMM ||
imm_type == RTRS_IO_RSP_W_INV_IMM)) {
u32 msg_id;
w_inval = (imm_type == RTRS_IO_RSP_W_INV_IMM);
rtrs_from_io_rsp_imm(imm_payload, &msg_id, &err);
if (WARN_ON(buf_id != msg_id))
goto out;
sess->rbufs[buf_id].rkey = le32_to_cpu(msg->rkey);
process_io_rsp(sess, msg_id, err, w_inval);
}
ib_dma_sync_single_for_device(sess->s.dev->ib_dev, iu->dma_addr,
iu->size, DMA_FROM_DEVICE);
return rtrs_clt_recv_done(con, wc);
out:
rtrs_rdma_error_recovery(con);
}
static void rtrs_clt_rdma_done(struct ib_cq *cq, struct ib_wc *wc);
static struct ib_cqe io_comp_cqe = {
.done = rtrs_clt_rdma_done
};
/*
* Post x2 empty WRs: first is for this RDMA with IMM,
* second is for RECV with INV, which happened earlier.
*/
static int rtrs_post_recv_empty_x2(struct rtrs_con *con, struct ib_cqe *cqe)
{
struct ib_recv_wr wr_arr[2], *wr;
int i;
memset(wr_arr, 0, sizeof(wr_arr));
for (i = 0; i < ARRAY_SIZE(wr_arr); i++) {
wr = &wr_arr[i];
wr->wr_cqe = cqe;
if (i)
/* Chain backwards */
wr->next = &wr_arr[i - 1];
}
return ib_post_recv(con->qp, wr, NULL);
}
static void rtrs_clt_rdma_done(struct ib_cq *cq, struct ib_wc *wc)
{
struct rtrs_clt_con *con = cq->cq_context;
struct rtrs_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) {
rtrs_err(sess->clt, "RDMA failed: %s\n",
ib_wc_status_msg(wc->status));
rtrs_rdma_error_recovery(con);
}
return;
}
rtrs_clt_update_wc_stats(con);
switch (wc->opcode) {
case IB_WC_RECV_RDMA_WITH_IMM:
/*
* post_recv() RDMA write completions of IO reqs (read/write)
* and hb
*/
if (WARN_ON(wc->wr_cqe->done != rtrs_clt_rdma_done))
return;
rtrs_from_imm(be32_to_cpu(wc->ex.imm_data),
&imm_type, &imm_payload);
if (likely(imm_type == RTRS_IO_RSP_IMM ||
imm_type == RTRS_IO_RSP_W_INV_IMM)) {
u32 msg_id;
w_inval = (imm_type == RTRS_IO_RSP_W_INV_IMM);
rtrs_from_io_rsp_imm(imm_payload, &msg_id, &err);
process_io_rsp(sess, msg_id, err, w_inval);
} else if (imm_type == RTRS_HB_MSG_IMM) {
WARN_ON(con->c.cid);
rtrs_send_hb_ack(&sess->s);
if (sess->flags == RTRS_MSG_NEW_RKEY_F)
return rtrs_clt_recv_done(con, wc);
} else if (imm_type == RTRS_HB_ACK_IMM) {
WARN_ON(con->c.cid);
sess->s.hb_missed_cnt = 0;
if (sess->flags == RTRS_MSG_NEW_RKEY_F)
return rtrs_clt_recv_done(con, wc);
} else {
rtrs_wrn(con->c.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 = rtrs_post_recv_empty_x2(&con->c, &io_comp_cqe);
else
err = rtrs_post_recv_empty(&con->c, &io_comp_cqe);
if (unlikely(err)) {
rtrs_err(con->c.sess, "rtrs_post_recv_empty(): %d\n",
err);
rtrs_rdma_error_recovery(con);
break;
}
break;
case IB_WC_RECV:
/*
* Key invalidations from server side
*/
WARN_ON(!(wc->wc_flags & IB_WC_WITH_INVALIDATE ||
wc->wc_flags & IB_WC_WITH_IMM));
WARN_ON(wc->wr_cqe->done != rtrs_clt_rdma_done);
if (sess->flags == RTRS_MSG_NEW_RKEY_F) {
if (wc->wc_flags & IB_WC_WITH_INVALIDATE)
return rtrs_clt_recv_done(con, wc);
return rtrs_clt_rkey_rsp_done(con, wc);
}
break;
case IB_WC_RDMA_WRITE:
/*
* post_send() RDMA write completions of IO reqs (read/write)
* and hb
*/
break;
default:
rtrs_wrn(sess->clt, "Unexpected WC type: %d\n", wc->opcode);
return;
}
}
static int post_recv_io(struct rtrs_clt_con *con, size_t q_size)
{
int err, i;
struct rtrs_clt_sess *sess = to_clt_sess(con->c.sess);
for (i = 0; i < q_size; i++) {
if (sess->flags == RTRS_MSG_NEW_RKEY_F) {
struct rtrs_iu *iu = &con->rsp_ius[i];
err = rtrs_iu_post_recv(&con->c, iu);
} else {
err = rtrs_post_recv_empty(&con->c, &io_comp_cqe);
}
if (unlikely(err))
return err;
}
return 0;
}
static int post_recv_sess(struct rtrs_clt_sess *sess)
{
size_t q_size = 0;
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)) {
rtrs_err(sess->clt, "post_recv_io(), err: %d\n", err);
return err;
}
}
return 0;
}
struct path_it {
int i;
struct list_head skip_list;
struct rtrs_clt *clt;
struct rtrs_clt_sess *(*next_path)(struct path_it *it);
};
/**
* 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.
* @it: the path pointer
*
* Related to @MP_POLICY_RR
*
* Locks:
* rcu_read_lock() must be hold.
*/
static struct rtrs_clt_sess *get_next_path_rr(struct path_it *it)
{
struct rtrs_clt_sess __rcu **ppcpu_path;
struct rtrs_clt_sess *path;
struct rtrs_clt *clt;
clt = it->clt;
/*
* Here we use two RCU objects: @paths_list and @pcpu_path
* pointer. See rtrs_clt_remove_path_from_arr() for details
* how that is handled.
*/
ppcpu_path = this_cpu_ptr(clt->pcpu_path);
path = rcu_dereference(*ppcpu_path);
if (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.
* @it: the path pointer
*
* Related to @MP_POLICY_MIN_INFLIGHT
*
* Locks:
* rcu_read_lock() must be hold.
*/
static struct rtrs_clt_sess *get_next_path_min_inflight(struct path_it *it)
{
struct rtrs_clt_sess *min_path = NULL;
struct rtrs_clt *clt = it->clt;
struct rtrs_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 rtrs_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);
}
/**
* rtrs_clt_init_req() Initialize an rtrs_clt_io_req holding information
* about an inflight IO.
* The user buffer holding user control message (not data) is copied into
* the corresponding buffer of rtrs_iu (req->iu->buf), which later on will
* also hold the control message of rtrs.
* @req: an io request holding information about IO.
* @sess: client session
* @conf: conformation callback function to notify upper layer.
* @permit: permit for allocation of RDMA remote buffer
* @priv: private pointer
* @vec: kernel vector containing control message
* @usr_len: length of the user message
* @sg: scater list for IO data
* @sg_cnt: number of scater list entries
* @data_len: length of the IO data
* @dir: direction of the IO.
*/
static void rtrs_clt_init_req(struct rtrs_clt_io_req *req,
struct rtrs_clt_sess *sess,
void (*conf)(void *priv, int errno),
struct rtrs_permit *permit, void *priv,
const struct kvec *vec, size_t usr_len,
struct scatterlist *sg, size_t sg_cnt,
size_t data_len, int dir)
{
struct iov_iter iter;
size_t len;
req->permit = permit;
req->in_use = true;
req->usr_len = usr_len;
req->data_len = data_len;
req->sglist = sg;
req->sg_cnt = sg_cnt;
req->priv = priv;
req->dir = dir;
req->con = rtrs_permit_to_clt_con(sess, permit);
req->conf = conf;
req->need_inv = false;
req->need_inv_comp = false;
req->inv_errno = 0;
iov_iter_kvec(&iter, READ, vec, 1, usr_len);
len = _copy_from_iter(req->iu->buf, usr_len, &iter);
WARN_ON(len != usr_len);
reinit_completion(&req->inv_comp);
}
static struct rtrs_clt_io_req *
rtrs_clt_get_req(struct rtrs_clt_sess *sess,
void (*conf)(void *priv, int errno),
struct rtrs_permit *permit, void *priv,
const struct kvec *vec, size_t usr_len,
struct scatterlist *sg, size_t sg_cnt,
size_t data_len, int dir)
{
struct rtrs_clt_io_req *req;
req = &sess->reqs[permit->mem_id];
rtrs_clt_init_req(req, sess, conf, permit, priv, vec, usr_len,
sg, sg_cnt, data_len, dir);
return req;
}
static struct rtrs_clt_io_req *
rtrs_clt_get_copy_req(struct rtrs_clt_sess *alive_sess,
struct rtrs_clt_io_req *fail_req)
{
struct rtrs_clt_io_req *req;
struct kvec vec = {
.iov_base = fail_req->iu->buf,
.iov_len = fail_req->usr_len
};
req = &alive_sess->reqs[fail_req->permit->mem_id];
rtrs_clt_init_req(req, alive_sess, fail_req->conf, fail_req->permit,
fail_req->priv, &vec, fail_req->usr_len,
fail_req->sglist, fail_req->sg_cnt,
fail_req->data_len, fail_req->dir);
return req;
}
static int rtrs_post_rdma_write_sg(struct rtrs_clt_con *con,
struct rtrs_clt_io_req *req,
struct rtrs_rbuf *rbuf,
u32 size, u32 imm)
{
struct rtrs_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 rtrs_iu_post_rdma_write_imm(&con->c, req->iu, sge, num_sge,
rbuf->rkey, rbuf->addr, imm,
flags, NULL);
}
static int rtrs_clt_write_req(struct rtrs_clt_io_req *req)
{
struct rtrs_clt_con *con = req->con;
struct rtrs_sess *s = con->c.sess;
struct rtrs_clt_sess *sess = to_clt_sess(s);
struct rtrs_msg_rdma_write *msg;
struct rtrs_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)) {
rtrs_wrn(s, "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)) {
rtrs_wrn(s, "Write request failed, map failed\n");
return -EINVAL;
}
}
/* put rtrs msg after sg and user message */
msg = req->iu->buf + req->usr_len;
msg->type = cpu_to_le16(RTRS_MSG_WRITE);
msg->usr_len = cpu_to_le16(req->usr_len);
/* rtrs message on server side will be after user data and message */
imm = req->permit->mem_off + req->data_len + req->usr_len;
imm = rtrs_to_io_req_imm(imm);
buf_id = req->permit->mem_id;
req->sg_size = tsize;
rbuf = &sess->rbufs[buf_id];
/*
* Update stats now, after request is successfully sent it is not
* safe anymore to touch it.
*/
rtrs_clt_update_all_stats(req, WRITE);
ret = rtrs_post_rdma_write_sg(req->con, req, rbuf,
req->usr_len + sizeof(*msg),
imm);
if (unlikely(ret)) {
rtrs_err(s, "Write request failed: %d\n", ret);
if (sess->clt->mp_policy == MP_POLICY_MIN_INFLIGHT)
atomic_dec(&sess->stats->inflight);
if (req->sg_cnt)
ib_dma_unmap_sg(sess->s.dev->ib_dev, req->sglist,
req->sg_cnt, req->dir);
}
return ret;
}
static int rtrs_map_sg_fr(struct rtrs_clt_io_req *req, size_t count)
{
int nr;
/* Align the MR to a 4K page size to match the block virt boundary */
nr = ib_map_mr_sg(req->mr, req->sglist, count, NULL, SZ_4K);
if (nr < 0)
return nr;
if (unlikely(nr < req->sg_cnt))
return -EINVAL;
ib_update_fast_reg_key(req->mr, ib_inc_rkey(req->mr->rkey));
return nr;
}
static int rtrs_clt_read_req(struct rtrs_clt_io_req *req)
{
struct rtrs_clt_con *con = req->con;
struct rtrs_sess *s = con->c.sess;
struct rtrs_clt_sess *sess = to_clt_sess(s);
struct rtrs_msg_rdma_read *msg;
struct rtrs_ib_dev *dev;
struct ib_reg_wr rwr;
struct ib_send_wr *wr = NULL;
int ret, count = 0;
u32 imm, buf_id;
const size_t tsize = sizeof(*msg) + req->data_len + req->usr_len;
s = &sess->s;
dev = sess->s.dev;
if (unlikely(tsize > sess->chunk_size)) {
rtrs_wrn(s,
"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)) {
rtrs_wrn(s,
"Read request failed, dma map failed\n");
return -EINVAL;
}
}
/* put our message into req->buf after user message*/
msg = req->iu->buf + req->usr_len;
msg->type = cpu_to_le16(RTRS_MSG_READ);
msg->usr_len = cpu_to_le16(req->usr_len);
if (count) {
ret = rtrs_map_sg_fr(req, count);
if (ret < 0) {
rtrs_err_rl(s,
"Read request failed, failed to map fast reg. data, err: %d\n",
ret);
ib_dma_unmap_sg(dev->ib_dev, req->sglist, req->sg_cnt,
req->dir);
return ret;
}
rwr = (struct ib_reg_wr) {
.wr.opcode = IB_WR_REG_MR,
.wr.wr_cqe = &fast_reg_cqe,
.mr = req->mr,
.key = req->mr->rkey,
.access = (IB_ACCESS_LOCAL_WRITE |
IB_ACCESS_REMOTE_WRITE),
};
wr = &rwr.wr;
msg->sg_cnt = cpu_to_le16(1);
msg->flags = cpu_to_le16(RTRS_MSG_NEED_INVAL_F);
msg->desc[0].addr = cpu_to_le64(req->mr->iova);
msg->desc[0].key = cpu_to_le32(req->mr->rkey);
msg->desc[0].len = cpu_to_le32(req->mr->length);
/* Further invalidation is required */
req->need_inv = !!RTRS_MSG_NEED_INVAL_F;
} else {
msg->sg_cnt = 0;
msg->flags = 0;
}
/*
* rtrs message will be after the space reserved for disk data and
* user message
*/
imm = req->permit->mem_off + req->data_len + req->usr_len;
imm = rtrs_to_io_req_imm(imm);
buf_id = req->permit->mem_id;
req->sg_size = sizeof(*msg);
req->sg_size += le16_to_cpu(msg->sg_cnt) * sizeof(struct rtrs_sg_desc);
req->sg_size += req->usr_len;
/*
* Update stats now, after request is successfully sent it is not
* safe anymore to touch it.
*/
rtrs_clt_update_all_stats(req, READ);
ret = rtrs_post_send_rdma(req->con, req, &sess->rbufs[buf_id],
req->data_len, imm, wr);
if (unlikely(ret)) {
rtrs_err(s, "Read request failed: %d\n", ret);
if (sess->clt->mp_policy == MP_POLICY_MIN_INFLIGHT)
atomic_dec(&sess->stats->inflight);
req->need_inv = false;
if (req->sg_cnt)
ib_dma_unmap_sg(dev->ib_dev, req->sglist,
req->sg_cnt, req->dir);
}
return ret;
}
/**
* rtrs_clt_failover_req() Try to find an active path for a failed request
* @clt: clt context
* @fail_req: a failed io request.
*/
static int rtrs_clt_failover_req(struct rtrs_clt *clt,
struct rtrs_clt_io_req *fail_req)
{
struct rtrs_clt_sess *alive_sess;
struct rtrs_clt_io_req *req;
int err = -ECONNABORTED;
struct path_it it;
rcu_read_lock();
for (path_it_init(&it, clt);
(alive_sess = it.next_path(&it)) && it.i < it.clt->paths_num;
it.i++) {
if (unlikely(READ_ONCE(alive_sess->state) !=
RTRS_CLT_CONNECTED))
continue;
req = rtrs_clt_get_copy_req(alive_sess, fail_req);
if (req->dir == DMA_TO_DEVICE)
err = rtrs_clt_write_req(req);
else
err = rtrs_clt_read_req(req);
if (unlikely(err)) {
req->in_use = false;
continue;
}
/* Success path */
rtrs_clt_inc_failover_cnt(alive_sess->stats);
break;
}
path_it_deinit(&it);
rcu_read_unlock();
return err;
}
static void fail_all_outstanding_reqs(struct rtrs_clt_sess *sess)
{
struct rtrs_clt *clt = sess->clt;
struct rtrs_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 useble and can
* be failovered to another path.
*/
complete_rdma_req(req, -ECONNABORTED, false, true);
err = rtrs_clt_failover_req(clt, req);
if (unlikely(err))
/* Failover failed, notify anyway */
req->conf(req->priv, err);
}
}
static void free_sess_reqs(struct rtrs_clt_sess *sess)
{
struct rtrs_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);
rtrs_iu_free(req->iu, DMA_TO_DEVICE,
sess->s.dev->ib_dev, 1);
}
kfree(sess->reqs);
sess->reqs = NULL;
}
static int alloc_sess_reqs(struct rtrs_clt_sess *sess)
{
struct rtrs_clt_io_req *req;
struct rtrs_clt *clt = sess->clt;
int i, err = -ENOMEM;
sess->reqs = kcalloc(sess->queue_depth, sizeof(*sess->reqs),
GFP_KERNEL);
if (!sess->reqs)
return -ENOMEM;
for (i = 0; i < sess->queue_depth; ++i) {
req = &sess->reqs[i];
req->iu = rtrs_iu_alloc(1, sess->max_hdr_size, GFP_KERNEL,
sess->s.dev->ib_dev,
DMA_TO_DEVICE,
rtrs_clt_rdma_done);
if (!req->iu)
goto out;
req->sge = kmalloc_array(clt->max_segments + 1,
sizeof(*req->sge), GFP_KERNEL);
if (!req->sge)
goto out;
req->mr = ib_alloc_mr(sess->s.dev->ib_pd, IB_MR_TYPE_MEM_REG,
sess->max_pages_per_mr);
if (IS_ERR(req->mr)) {
err = PTR_ERR(req->mr);
req->mr = NULL;
pr_err("Failed to alloc sess->max_pages_per_mr %d\n",
sess->max_pages_per_mr);
goto out;
}
init_completion(&req->inv_comp);
}
return 0;
out:
free_sess_reqs(sess);
return err;
}
static int alloc_permits(struct rtrs_clt *clt)
{
unsigned int chunk_bits;
int err, i;
clt->permits_map = kcalloc(BITS_TO_LONGS(clt->queue_depth),
sizeof(long), GFP_KERNEL);
if (!clt->permits_map) {
err = -ENOMEM;
goto out_err;
}
clt->permits = kcalloc(clt->queue_depth, permit_size(clt), GFP_KERNEL);
if (!clt->permits) {
err = -ENOMEM;
goto err_map;
}
chunk_bits = ilog2(clt->queue_depth - 1) + 1;
for (i = 0; i < clt->queue_depth; i++) {
struct rtrs_permit *permit;
permit = get_permit(clt, i);
permit->mem_id = i;
permit->mem_off = i << (MAX_IMM_PAYL_BITS - chunk_bits);
}
return 0;
err_map:
kfree(clt->permits_map);
clt->permits_map = NULL;
out_err:
return err;
}
static void free_permits(struct rtrs_clt *clt)
{
kfree(clt->permits_map);
clt->permits_map = NULL;
kfree(clt->permits);
clt->permits = NULL;
}
static void query_fast_reg_mode(struct rtrs_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_send_sge = ib_dev->attrs.max_send_sge;
}
static bool rtrs_clt_change_state_get_old(struct rtrs_clt_sess *sess,
enum rtrs_clt_state new_state,
enum rtrs_clt_state *old_state)
{
bool changed;
spin_lock_irq(&sess->state_wq.lock);
*old_state = sess->state;
changed = __rtrs_clt_change_state(sess, new_state);
spin_unlock_irq(&sess->state_wq.lock);
return changed;
}
static bool rtrs_clt_change_state(struct rtrs_clt_sess *sess,
enum rtrs_clt_state new_state)
{
enum rtrs_clt_state old_state;
return rtrs_clt_change_state_get_old(sess, new_state, &old_state);
}
static void rtrs_clt_hb_err_handler(struct rtrs_con *c)
{
struct rtrs_clt_con *con = container_of(c, typeof(*con), c);
rtrs_rdma_error_recovery(con);
}
static void rtrs_clt_init_hb(struct rtrs_clt_sess *sess)
{
rtrs_init_hb(&sess->s, &io_comp_cqe,
RTRS_HB_INTERVAL_MS,
RTRS_HB_MISSED_MAX,
rtrs_clt_hb_err_handler,
rtrs_wq);
}
static void rtrs_clt_start_hb(struct rtrs_clt_sess *sess)
{
rtrs_start_hb(&sess->s);
}
static void rtrs_clt_stop_hb(struct rtrs_clt_sess *sess)
{
rtrs_stop_hb(&sess->s);
}
static void rtrs_clt_reconnect_work(struct work_struct *work);
static void rtrs_clt_close_work(struct work_struct *work);
static struct rtrs_clt_sess *alloc_sess(struct rtrs_clt *clt,
const struct rtrs_addr *path,
size_t con_num, u16 max_segments,
size_t max_segment_size)
{
struct rtrs_clt_sess *sess;
int err = -ENOMEM;
int cpu;
sess = kzalloc(sizeof(*sess), GFP_KERNEL);
if (!sess)
goto err;
/* Extra connection for user messages */
con_num += 1;
sess->s.con = kcalloc(con_num, sizeof(*sess->s.con), GFP_KERNEL);
if (!sess->s.con)
goto err_free_sess;
sess->stats = kzalloc(sizeof(*sess->stats), GFP_KERNEL);
if (!sess->stats)
goto err_free_con;
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 * max_segment_size >> 12;
init_waitqueue_head(&sess->state_wq);
sess->state = RTRS_CLT_CONNECTING;
atomic_set(&sess->connected_cnt, 0);
INIT_WORK(&sess->close_work, rtrs_clt_close_work);
INIT_DELAYED_WORK(&sess->reconnect_dwork, rtrs_clt_reconnect_work);
rtrs_clt_init_hb(sess);
sess->mp_skip_entry = alloc_percpu(typeof(*sess->mp_skip_entry));
if (!sess->mp_skip_entry)
goto err_free_stats;
for_each_possible_cpu(cpu)
INIT_LIST_HEAD(per_cpu_ptr(sess->mp_skip_entry, cpu));
err = rtrs_clt_init_stats(sess->stats);
if (err)
goto err_free_percpu;
return sess;
err_free_percpu:
free_percpu(sess->mp_skip_entry);
err_free_stats:
kfree(sess->stats);
err_free_con:
kfree(sess->s.con);
err_free_sess:
kfree(sess);
err:
return ERR_PTR(err);
}
void free_sess(struct rtrs_clt_sess *sess)
{
free_percpu(sess->mp_skip_entry);
mutex_destroy(&sess->init_mutex);
kfree(sess->s.con);
kfree(sess->rbufs);
kfree(sess);
}
static int create_con(struct rtrs_clt_sess *sess, unsigned int cid)
{
struct rtrs_clt_con *con;
con = kzalloc(sizeof(*con), GFP_KERNEL);
if (!con)
return -ENOMEM;
/* Map first two connections to the first CPU */
con->cpu = (cid ? cid - 1 : 0) % nr_cpu_ids;
con->c.cid = cid;
con->c.sess = &sess->s;
atomic_set(&con->io_cnt, 0);
sess->s.con[cid] = &con->c;
return 0;
}
static void destroy_con(struct rtrs_clt_con *con)
{
struct rtrs_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 rtrs_clt_con *con)
{
struct rtrs_clt_sess *sess = to_clt_sess(con->c.sess);
u16 wr_queue_size;
int err, cq_vector;
struct rtrs_msg_rkey_rsp *rsp;
/*
* 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
*/
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 = rtrs_ib_dev_find_or_add(con->c.cm_id->device,
&dev_pd);
if (!sess->s.dev) {
rtrs_wrn(sess->clt,
"rtrs_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++;
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);
}
/* alloc iu to recv new rkey reply when server reports flags set */
if (sess->flags == RTRS_MSG_NEW_RKEY_F || con->c.cid == 0) {
con->rsp_ius = rtrs_iu_alloc(wr_queue_size, sizeof(*rsp),
GFP_KERNEL, sess->s.dev->ib_dev,
DMA_FROM_DEVICE,
rtrs_clt_rdma_done);
if (!con->rsp_ius)
return -ENOMEM;
con->queue_size = wr_queue_size;
}
cq_vector = con->cpu % sess->s.dev->ib_dev->num_comp_vectors;
err = rtrs_cq_qp_create(&sess->s, &con->c, sess->max_send_sge,
cq_vector, wr_queue_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.
*/
return err;
}
static void destroy_con_cq_qp(struct rtrs_clt_con *con)
{
struct rtrs_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.
*/
rtrs_cq_qp_destroy(&con->c);
if (con->rsp_ius) {
rtrs_iu_free(con->rsp_ius, DMA_FROM_DEVICE,
sess->s.dev->ib_dev, con->queue_size);
con->rsp_ius = NULL;
con->queue_size = 0;
}
if (sess->s.dev_ref && !--sess->s.dev_ref) {
rtrs_ib_dev_put(sess->s.dev);
sess->s.dev = NULL;
}
}
static void stop_cm(struct rtrs_clt_con *con)
{
rdma_disconnect(con->c.cm_id);
if (con->c.qp)
ib_drain_qp(con->c.qp);
}
static void destroy_cm(struct rtrs_clt_con *con)
{
rdma_destroy_id(con->c.cm_id);
con->c.cm_id = NULL;
}
static int rtrs_rdma_addr_resolved(struct rtrs_clt_con *con)
{
struct rtrs_sess *s = con->c.sess;
int err;
err = create_con_cq_qp(con);
if (err) {
rtrs_err(s, "create_con_cq_qp(), err: %d\n", err);
return err;
}
err = rdma_resolve_route(con->c.cm_id, RTRS_CONNECT_TIMEOUT_MS);
if (err) {
rtrs_err(s, "Resolving route failed, err: %d\n", err);
destroy_con_cq_qp(con);
}
return err;
}
static int rtrs_rdma_route_resolved(struct rtrs_clt_con *con)
{
struct rtrs_clt_sess *sess = to_clt_sess(con->c.sess);
struct rtrs_clt *clt = sess->clt;
struct rtrs_msg_conn_req msg;
struct rdma_conn_param param;
int err;
param = (struct rdma_conn_param) {
.retry_count = 7,
.rnr_retry_count = 7,
.private_data = &msg,
.private_data_len = sizeof(msg),
};
msg = (struct rtrs_msg_conn_req) {
.magic = cpu_to_le16(RTRS_MAGIC),
.version = cpu_to_le16(RTRS_PROTO_VER),
.cid = cpu_to_le16(con->c.cid),
.cid_num = cpu_to_le16(sess->s.con_num),
.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)
rtrs_err(clt, "rdma_connect(): %d\n", err);
return err;
}
static int rtrs_rdma_conn_established(struct rtrs_clt_con *con,
struct rdma_cm_event *ev)
{
struct rtrs_clt_sess *sess = to_clt_sess(con->c.sess);
struct rtrs_clt *clt = sess->clt;
const struct rtrs_msg_conn_rsp *msg;
u16 version, queue_depth;
int errno;
u8 len;
msg = ev->param.conn.private_data;
len = ev->param.conn.private_data_len;
if (len < sizeof(*msg)) {
rtrs_err(clt, "Invalid RTRS connection response\n");
return -ECONNRESET;
}
if (le16_to_cpu(msg->magic) != RTRS_MAGIC) {
rtrs_err(clt, "Invalid RTRS magic\n");
return -ECONNRESET;
}
version = le16_to_cpu(msg->version);
if (version >> 8 != RTRS_PROTO_VER_MAJOR) {
rtrs_err(clt, "Unsupported major RTRS version: %d, expected %d\n",
version >> 8, RTRS_PROTO_VER_MAJOR);
return -ECONNRESET;
}
errno = le16_to_cpu(msg->errno);
if (errno) {
rtrs_err(clt, "Invalid RTRS message: errno %d\n",
errno);
return -ECONNRESET;
}
if (con->c.cid == 0) {
queue_depth = le16_to_cpu(msg->queue_depth);
if (queue_depth > MAX_SESS_QUEUE_DEPTH) {
rtrs_err(clt, "Invalid RTRS 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 (!sess->rbufs)
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->flags = le32_to_cpu(msg->flags);
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 inline void flag_success_on_conn(struct rtrs_clt_con *con)
{
struct rtrs_clt_sess *sess = to_clt_sess(con->c.sess);
atomic_inc(&sess->connected_cnt);
con->cm_err = 1;
}
static int rtrs_rdma_conn_rejected(struct rtrs_clt_con *con,
struct rdma_cm_event *ev)
{
struct rtrs_sess *s = con->c.sess;
const struct rtrs_msg_conn_rsp *msg;
const char *rej_msg;
int status, errno;
u8 data_len;
status = ev->status;
rej_msg = rdma_reject_msg(con->c.cm_id, status);
msg = rdma_consumer_reject_data(con->c.cm_id, ev, &data_len);
if (msg && data_len >= sizeof(*msg)) {
errno = (int16_t)le16_to_cpu(msg->errno);
if (errno == -EBUSY)
rtrs_err(s,
"Previous session is still exists on the server, please reconnect later\n");
else
rtrs_err(s,
"Connect rejected: status %d (%s), rtrs errno %d\n",
status, rej_msg, errno);
} else {
rtrs_err(s,
"Connect rejected but with malformed message: status %d (%s)\n",
status, rej_msg);
}
return -ECONNRESET;
}
static void rtrs_clt_close_conns(struct rtrs_clt_sess *sess, bool wait)
{
if (rtrs_clt_change_state(sess, RTRS_CLT_CLOSING))
queue_work(rtrs_wq, &sess->close_work);
if (wait)
flush_work(&sess->close_work);
}
static inline void flag_error_on_conn(struct rtrs_clt_con *con, int cm_err)
{
if (con->cm_err == 1) {
struct rtrs_clt_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 rtrs_clt_rdma_cm_handler(struct rdma_cm_id *cm_id,
struct rdma_cm_event *ev)
{
struct rtrs_clt_con *con = cm_id->context;
struct rtrs_sess *s = con->c.sess;
struct rtrs_clt_sess *sess = to_clt_sess(s);
int cm_err = 0;
switch (ev->event) {
case RDMA_CM_EVENT_ADDR_RESOLVED:
cm_err = rtrs_rdma_addr_resolved(con);
break;
case RDMA_CM_EVENT_ROUTE_RESOLVED:
cm_err = rtrs_rdma_route_resolved(con);
break;
case RDMA_CM_EVENT_ESTABLISHED:
con->cm_err = rtrs_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 = rtrs_rdma_conn_rejected(con, ev);
break;
case RDMA_CM_EVENT_CONNECT_ERROR:
case RDMA_CM_EVENT_UNREACHABLE:
rtrs_wrn(s, "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.
*/
rtrs_clt_close_conns(sess, false);
return 0;
default:
rtrs_err(s, "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);
rtrs_rdma_error_recovery(con);
}
return 0;
}
static int create_cm(struct rtrs_clt_con *con)
{
struct rtrs_sess *s = con->c.sess;
struct rtrs_clt_sess *sess = to_clt_sess(s);
struct rdma_cm_id *cm_id;
int err;
cm_id = rdma_create_id(&init_net, rtrs_clt_rdma_cm_handler, con,
sess->s.dst_addr.ss_family == AF_IB ?
RDMA_PS_IB : RDMA_PS_TCP, IB_QPT_RC);
if (IS_ERR(cm_id)) {
err = PTR_ERR(cm_id);
rtrs_err(s, "Failed to create CM ID, err: %d\n", err);
return err;
}
con->c.cm_id = cm_id;
con->cm_err = 0;
/* allow the port to be reused */
err = rdma_set_reuseaddr(cm_id, 1);
if (err != 0) {
rtrs_err(s, "Set address reuse failed, err: %d\n", err);
goto destroy_cm;
}
err = rdma_resolve_addr(cm_id, (struct sockaddr *)&sess->s.src_addr,
(struct sockaddr *)&sess->s.dst_addr,
RTRS_CONNECT_TIMEOUT_MS);
if (err) {
rtrs_err(s, "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 != RTRS_CLT_CONNECTING,
msecs_to_jiffies(RTRS_CONNECT_TIMEOUT_MS));
if (err == 0 || err == -ERESTARTSYS) {
if (err == 0)
err = -ETIMEDOUT;
/* Timedout or interrupted */
goto errr;
}
if (con->cm_err < 0) {
err = con->cm_err;
goto errr;
}
if (READ_ONCE(sess->state) != RTRS_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 rtrs_clt_sess_up(struct rtrs_clt_sess *sess)
{
struct rtrs_clt *clt = sess->clt;
int up;
/*
* We can fire RECONNECTED event only when all paths were
* connected on rtrs_clt_open(), then each was disconnected
* and the first one connected again. That's why this nasty
* game with counter value.
*/
mutex_lock(&clt->paths_ev_mutex);
up = ++clt->paths_up;
/*
* Here it is safe to access paths num directly since up counter
* is greater than MAX_PATHS_NUM only while rtrs_clt_open() is
* in progress, thus paths removals are impossible.
*/
if (up > MAX_PATHS_NUM && up == MAX_PATHS_NUM + clt->paths_num)
clt->paths_up = clt->paths_num;
else if (up == 1)
clt->link_ev(clt->priv, RTRS_CLT_LINK_EV_RECONNECTED);
mutex_unlock(&clt->paths_ev_mutex);
/* Mark session as established */
sess->established = true;
sess->reconnect_attempts = 0;
sess->stats->reconnects.successful_cnt++;
}
static void rtrs_clt_sess_down(struct rtrs_clt_sess *sess)
{
struct rtrs_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, RTRS_CLT_LINK_EV_DISCONNECTED);
mutex_unlock(&clt->paths_ev_mutex);
}
static void rtrs_clt_stop_and_destroy_conns(struct rtrs_clt_sess *sess)
{
struct rtrs_clt_con *con;
unsigned int cid;
WARN_ON(READ_ONCE(sess->state) == RTRS_CLT_CONNECTED);
/*
* Possible race with rtrs_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();
rtrs_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);
rtrs_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(RTRS_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 rtrs_clt_sess __rcu **rcu_ppcpu_path,
struct rtrs_clt_sess *sess,
struct rtrs_clt_sess *next)
{
struct rtrs_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 rtrs_clt_remove_path_from_arr(struct rtrs_clt_sess *sess)
{
struct rtrs_clt *clt = sess->clt;
struct rtrs_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(): rtrs_clt_remove_path_from_arr():
* path = get_next_path()
* ^^^ list_del_rcu(path)
* [!CONNECTED path] clt->paths_num--
* ^^^^^^^^^
* load clt->paths_num from 2 to 1
* ^^^^^^^^^
* sees 1
*
* path is observed as !CONNECTED, but do_each_path() loop
* ends, because expression i < clt->paths_num is false.
*/
clt->paths_num--;
/*
* Get @next connection from current @sess which is going to be
* removed. If @sess is the last element, then @next is NULL.
*/
rcu_read_lock();
next = list_next_or_null_rr_rcu(&clt->paths_list, &sess->s.entry,
typeof(*next), s.entry);
rcu_read_unlock();
/*
* @pcpu paths can still point to the path which is going to be
* removed, so change the pointer manually.
*/
for_each_possible_cpu(cpu) {
struct rtrs_clt_sess __rcu **ppcpu_path;
ppcpu_path = per_cpu_ptr(clt->pcpu_path, cpu);
if (rcu_dereference_protected(*ppcpu_path,
lockdep_is_held(&clt->paths_mutex)) != 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 rtrs_clt_add_path_to_arr(struct rtrs_clt_sess *sess,
struct rtrs_addr *addr)
{
struct rtrs_clt *clt = sess->clt;
mutex_lock(&clt->paths_mutex);
clt->paths_num++;
list_add_tail_rcu(&sess->s.entry, &clt->paths_list);
mutex_unlock(&clt->paths_mutex);
}
static void rtrs_clt_close_work(struct work_struct *work)
{
struct rtrs_clt_sess *sess;
sess = container_of(work, struct rtrs_clt_sess, close_work);
cancel_delayed_work_sync(&sess->reconnect_dwork);
rtrs_clt_stop_and_destroy_conns(sess);
rtrs_clt_change_state(sess, RTRS_CLT_CLOSED);
}
static int init_conns(struct rtrs_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 (err)
goto destroy;
err = create_cm(to_clt_con(sess->s.con[cid]));
if (err) {
destroy_con(to_clt_con(sess->s.con[cid]));
goto destroy;
}
}
err = alloc_sess_reqs(sess);
if (err)
goto destroy;
rtrs_clt_start_hb(sess);
return 0;
destroy:
while (cid--) {
struct rtrs_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.
*/
rtrs_clt_change_state(sess, RTRS_CLT_CONNECTING_ERR);
return err;
}
static void rtrs_clt_info_req_done(struct ib_cq *cq, struct ib_wc *wc)
{
struct rtrs_clt_con *con = cq->cq_context;
struct rtrs_clt_sess *sess = to_clt_sess(con->c.sess);
struct rtrs_iu *iu;
iu = container_of(wc->wr_cqe, struct rtrs_iu, cqe);
rtrs_iu_free(iu, DMA_TO_DEVICE, sess->s.dev->ib_dev, 1);
if (unlikely(wc->status != IB_WC_SUCCESS)) {
rtrs_err(sess->clt, "Sess info request send failed: %s\n",
ib_wc_status_msg(wc->status));
rtrs_clt_change_state(sess, RTRS_CLT_CONNECTING_ERR);
return;
}
rtrs_clt_update_wc_stats(con);
}
static int process_info_rsp(struct rtrs_clt_sess *sess,
const struct rtrs_msg_info_rsp *msg)
{
unsigned int sg_cnt, total_len;
int i, sgi;
sg_cnt = le16_to_cpu(msg->sg_cnt);
if (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)) {
rtrs_err(sess->clt,
"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))) {
rtrs_err(sess->clt, "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 rtrs_sg_desc *desc = &msg->desc[sgi];
u32 len, rkey;
u64 addr;
addr = le64_to_cpu(desc->addr);
rkey = le32_to_cpu(desc->key);
len = le32_to_cpu(desc->len);
total_len += len;
if (unlikely(!len || (len % sess->chunk_size))) {
rtrs_err(sess->clt, "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)) {
rtrs_err(sess->clt, "Incorrect sg vector, not fully mapped\n");
return -EINVAL;
}
if (unlikely(total_len != sess->chunk_size * sess->queue_depth)) {
rtrs_err(sess->clt, "Incorrect total_len %d\n", total_len);
return -EINVAL;
}
return 0;
}
static void rtrs_clt_info_rsp_done(struct ib_cq *cq, struct ib_wc *wc)
{
struct rtrs_clt_con *con = cq->cq_context;
struct rtrs_clt_sess *sess = to_clt_sess(con->c.sess);
struct rtrs_msg_info_rsp *msg;
enum rtrs_clt_state state;
struct rtrs_iu *iu;
size_t rx_sz;
int err;
state = RTRS_CLT_CONNECTING_ERR;
WARN_ON(con->c.cid);
iu = container_of(wc->wr_cqe, struct rtrs_iu, cqe);
if (unlikely(wc->status != IB_WC_SUCCESS)) {
rtrs_err(sess->clt, "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))) {
rtrs_err(sess->clt, "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) != RTRS_MSG_INFO_RSP)) {
rtrs_err(sess->clt, "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)) {
rtrs_err(sess->clt, "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 = RTRS_CLT_CONNECTED;
out:
rtrs_clt_update_wc_stats(con);
rtrs_iu_free(iu, DMA_FROM_DEVICE, sess->s.dev->ib_dev, 1);
rtrs_clt_change_state(sess, state);
}
static int rtrs_send_sess_info(struct rtrs_clt_sess *sess)
{
struct rtrs_clt_con *usr_con = to_clt_con(sess->s.con[0]);
struct rtrs_msg_info_req *msg;
struct rtrs_iu *tx_iu, *rx_iu;
size_t rx_sz;
int err;
rx_sz = sizeof(struct rtrs_msg_info_rsp);
rx_sz += sizeof(u64) * MAX_SESS_QUEUE_DEPTH;
tx_iu = rtrs_iu_alloc(1, sizeof(struct rtrs_msg_info_req), GFP_KERNEL,
sess->s.dev->ib_dev, DMA_TO_DEVICE,
rtrs_clt_info_req_done);
rx_iu = rtrs_iu_alloc(1, rx_sz, GFP_KERNEL, sess->s.dev->ib_dev,
DMA_FROM_DEVICE, rtrs_clt_info_rsp_done);
if (unlikely(!tx_iu || !rx_iu)) {
err = -ENOMEM;
goto out;
}
/* Prepare for getting info response */
err = rtrs_iu_post_recv(&usr_con->c, rx_iu);
if (unlikely(err)) {
rtrs_err(sess->clt, "rtrs_iu_post_recv(), err: %d\n", err);
goto out;
}
rx_iu = NULL;
msg = tx_iu->buf;
msg->type = cpu_to_le16(RTRS_MSG_INFO_REQ);
memcpy(msg->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 = rtrs_iu_post_send(&usr_con->c, tx_iu, sizeof(*msg), NULL);
if (unlikely(err)) {
rtrs_err(sess->clt, "rtrs_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 != RTRS_CLT_CONNECTING,
msecs_to_jiffies(
RTRS_CONNECT_TIMEOUT_MS));
if (unlikely(READ_ONCE(sess->state) != RTRS_CLT_CONNECTED)) {
if (READ_ONCE(sess->state) == RTRS_CLT_CONNECTING_ERR)
err = -ECONNRESET;
else
err = -ETIMEDOUT;
goto out;
}
out:
if (tx_iu)
rtrs_iu_free(tx_iu, DMA_TO_DEVICE, sess->s.dev->ib_dev, 1);
if (rx_iu)
rtrs_iu_free(rx_iu, DMA_FROM_DEVICE, sess->s.dev->ib_dev, 1);
if (unlikely(err))
/* If we've never taken async path because of malloc problems */
rtrs_clt_change_state(sess, RTRS_CLT_CONNECTING_ERR);
return err;
}
/**
* init_sess() - establishes all session connections and does handshake
* @sess: client session.
* 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 rtrs_clt_sess *sess)
{
int err;
mutex_lock(&sess->init_mutex);
err = init_conns(sess);
if (err) {
rtrs_err(sess->clt, "init_conns(), err: %d\n", err);
goto out;
}
err = rtrs_send_sess_info(sess);
if (err) {
rtrs_err(sess->clt, "rtrs_send_sess_info(), err: %d\n", err);
goto out;
}
rtrs_clt_sess_up(sess);
out:
mutex_unlock(&sess->init_mutex);
return err;
}
static void rtrs_clt_reconnect_work(struct work_struct *work)
{
struct rtrs_clt_sess *sess;
struct rtrs_clt *clt;
unsigned int delay_ms;
int err;
sess = container_of(to_delayed_work(work), struct rtrs_clt_sess,
reconnect_dwork);
clt = sess->clt;
if (READ_ONCE(sess->state) != RTRS_CLT_RECONNECTING)
return;
if (sess->reconnect_attempts >= clt->max_reconnect_attempts) {
/* Close a session completely if max attempts is reached */
rtrs_clt_close_conns(sess, false);
return;
}
sess->reconnect_attempts++;
/* Stop everything */
rtrs_clt_stop_and_destroy_conns(sess);
msleep(RTRS_RECONNECT_BACKOFF);
if (rtrs_clt_change_state(sess, RTRS_CLT_CONNECTING)) {
err = init_sess(sess);
if (err)
goto reconnect_again;
}
return;
reconnect_again:
if (rtrs_clt_change_state(sess, RTRS_CLT_RECONNECTING)) {
sess->stats->reconnects.fail_cnt++;
delay_ms = clt->reconnect_delay_sec * 1000;
queue_delayed_work(rtrs_wq, &sess->reconnect_dwork,
msecs_to_jiffies(delay_ms +
prandom_u32() %
RTRS_RECONNECT_SEED));
}
}
static void rtrs_clt_dev_release(struct device *dev)
{
struct rtrs_clt *clt = container_of(dev, struct rtrs_clt, dev);
kfree(clt);
}
static struct rtrs_clt *alloc_clt(const char *sessname, size_t paths_num,
u16 port, size_t pdu_sz, void *priv,
void (*link_ev)(void *priv,
enum rtrs_clt_link_ev ev),
unsigned int max_segments,
size_t max_segment_size,
unsigned int reconnect_delay_sec,
unsigned int max_reconnect_attempts)
{
struct rtrs_clt *clt;
int err;
if (!paths_num || paths_num > MAX_PATHS_NUM)
return ERR_PTR(-EINVAL);
if (strlen(sessname) >= sizeof(clt->sessname))
return ERR_PTR(-EINVAL);
clt = kzalloc(sizeof(*clt), GFP_KERNEL);
if (!clt)
return ERR_PTR(-ENOMEM);
clt->pcpu_path = alloc_percpu(typeof(*clt->pcpu_path));
if (!clt->pcpu_path) {
kfree(clt);
return ERR_PTR(-ENOMEM);
}
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->max_segment_size = max_segment_size;
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->permits_wait);
mutex_init(&clt->paths_ev_mutex);
mutex_init(&clt->paths_mutex);
clt->dev.class = rtrs_clt_dev_class;
clt->dev.release = rtrs_clt_dev_release;
err = dev_set_name(&clt->dev, "%s", sessname);
if (err) {
free_percpu(clt->pcpu_path);
kfree(clt);
return ERR_PTR(err);
}
/*
* Suppress user space notification until
* sysfs files are created
*/
dev_set_uevent_suppress(&clt->dev, true);
err = device_register(&clt->dev);
if (err) {
free_percpu(clt->pcpu_path);
put_device(&clt->dev);
return ERR_PTR(err);
}
clt->kobj_paths = kobject_create_and_add("paths", &clt->dev.kobj);
if (!clt->kobj_paths) {
free_percpu(clt->pcpu_path);
device_unregister(&clt->dev);
return NULL;
}
err = rtrs_clt_create_sysfs_root_files(clt);
if (err) {
free_percpu(clt->pcpu_path);
kobject_del(clt->kobj_paths);
kobject_put(clt->kobj_paths);
device_unregister(&clt->dev);
return ERR_PTR(err);
}
dev_set_uevent_suppress(&clt->dev, false);
kobject_uevent(&clt->dev.kobj, KOBJ_ADD);
return clt;
}
static void wait_for_inflight_permits(struct rtrs_clt *clt)
{
if (clt->permits_map) {
size_t sz = clt->queue_depth;
wait_event(clt->permits_wait,
find_first_bit(clt->permits_map, sz) >= sz);
}
}
static void free_clt(struct rtrs_clt *clt)
{
wait_for_inflight_permits(clt);
free_permits(clt);
free_percpu(clt->pcpu_path);
mutex_destroy(&clt->paths_ev_mutex);
mutex_destroy(&clt->paths_mutex);
/* release callback will free clt in last put */
device_unregister(&clt->dev);
}
/**
* rtrs_clt_open() - Open a session to an RTRS server
* @ops: holds the link event callback and the private pointer.
* @sessname: name of the session
* @paths: Paths to be established defined by their src and dst addresses
* @paths_num: Number of elements in the @paths array
* @port: port to be used by the RTRS session
* @pdu_sz: Size of extra payload which can be accessed after permit allocation.
* @reconnect_delay_sec: time between reconnect tries
* @max_segments: Max. number of segments per IO request
* @max_segment_size: Max. size of one segment
* @max_reconnect_attempts: Number of times to reconnect on error before giving
* up, 0 for * disabled, -1 for forever
*
* Starts session establishment with the rtrs_server. The function can block
* up to ~2000ms before it returns.
*
* Return a valid pointer on success otherwise PTR_ERR.
*/
struct rtrs_clt *rtrs_clt_open(struct rtrs_clt_ops *ops,
const char *sessname,
const struct rtrs_addr *paths,
size_t paths_num, u16 port,
size_t pdu_sz, u8 reconnect_delay_sec,
u16 max_segments,
size_t max_segment_size,
s16 max_reconnect_attempts)
{
struct rtrs_clt_sess *sess, *tmp;
struct rtrs_clt *clt;
int err, i;
clt = alloc_clt(sessname, paths_num, port, pdu_sz, ops->priv,
ops->link_ev,
max_segments, max_segment_size, reconnect_delay_sec,
max_reconnect_attempts);
if (IS_ERR(clt)) {
err = PTR_ERR(clt);
goto out;
}
for (i = 0; i < paths_num; i++) {
struct rtrs_clt_sess *sess;
sess = alloc_sess(clt, &paths[i], nr_cpu_ids,
max_segments, max_segment_size);
if (IS_ERR(sess)) {
err = PTR_ERR(sess);
goto close_all_sess;
}
list_add_tail_rcu(&sess->s.entry, &clt->paths_list);
err = init_sess(sess);
if (err) {
list_del_rcu(&sess->s.entry);
rtrs_clt_close_conns(sess, true);
free_sess(sess);
goto close_all_sess;
}
err = rtrs_clt_create_sess_files(sess);
if (err) {
list_del_rcu(&sess->s.entry);
rtrs_clt_close_conns(sess, true);
free_sess(sess);
goto close_all_sess;
}
}
err = alloc_permits(clt);
if (err)
goto close_all_sess;
return clt;
close_all_sess:
list_for_each_entry_safe(sess, tmp, &clt->paths_list, s.entry) {
rtrs_clt_destroy_sess_files(sess, NULL);
rtrs_clt_close_conns(sess, true);
kobject_put(&sess->kobj);
}
rtrs_clt_destroy_sysfs_root_files(clt);
rtrs_clt_destroy_sysfs_root_folders(clt);
free_clt(clt);
out:
return ERR_PTR(err);
}
EXPORT_SYMBOL(rtrs_clt_open);
/**
* rtrs_clt_close() - Close a session
* @clt: Session handle. Session is freed upon return.
*/
void rtrs_clt_close(struct rtrs_clt *clt)
{
struct rtrs_clt_sess *sess, *tmp;
/* Firstly forbid sysfs access */
rtrs_clt_destroy_sysfs_root_files(clt);
rtrs_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) {
rtrs_clt_destroy_sess_files(sess, NULL);
rtrs_clt_close_conns(sess, true);
kobject_put(&sess->kobj);
}
free_clt(clt);
}
EXPORT_SYMBOL(rtrs_clt_close);
int rtrs_clt_reconnect_from_sysfs(struct rtrs_clt_sess *sess)
{
enum rtrs_clt_state old_state;
int err = -EBUSY;
bool changed;
changed = rtrs_clt_change_state_get_old(sess, RTRS_CLT_RECONNECTING,
&old_state);
if (changed) {
sess->reconnect_attempts = 0;
queue_delayed_work(rtrs_wq, &sess->reconnect_dwork, 0);
}
if (changed || old_state == RTRS_CLT_RECONNECTING) {
/*
* flush_delayed_work() queues pending work for immediate
* execution, so do the flush if we have queued something
* right now or work is pending.
*/
flush_delayed_work(&sess->reconnect_dwork);
err = (READ_ONCE(sess->state) ==
RTRS_CLT_CONNECTED ? 0 : -ENOTCONN);
}
return err;
}
int rtrs_clt_disconnect_from_sysfs(struct rtrs_clt_sess *sess)
{
rtrs_clt_close_conns(sess, true);
return 0;
}
int rtrs_clt_remove_path_from_sysfs(struct rtrs_clt_sess *sess,
const struct attribute *sysfs_self)
{
enum rtrs_clt_state old_state;
bool changed;
/*
* Continue stopping path till state was changed to DEAD or
* state was observed as DEAD:
* 1. State was changed to DEAD - we were fast and nobody
* invoked rtrs_clt_reconnect(), which can again start
* reconnecting.
* 2. State was observed as DEAD - we have someone in parallel
* removing the path.
*/
do {
rtrs_clt_close_conns(sess, true);
changed = rtrs_clt_change_state_get_old(sess,
RTRS_CLT_DEAD,
&old_state);
} while (!changed && old_state != RTRS_CLT_DEAD);
if (likely(changed)) {
rtrs_clt_destroy_sess_files(sess, sysfs_self);
rtrs_clt_remove_path_from_arr(sess);
kobject_put(&sess->kobj);
}
return 0;
}
void rtrs_clt_set_max_reconnect_attempts(struct rtrs_clt *clt, int value)
{
clt->max_reconnect_attempts = (unsigned int)value;
}
int rtrs_clt_get_max_reconnect_attempts(const struct rtrs_clt *clt)
{
return (int)clt->max_reconnect_attempts;
}
/**
* rtrs_clt_request() - Request data transfer to/from server via RDMA.
*
* @dir: READ/WRITE
* @ops: callback function to be called as confirmation, and the pointer.
* @clt: Session
* @permit: Preallocated permit
* @vec: Message that is sent to server together with the request.
* Sum of len of all @vec elements limited to <= IO_MSG_SIZE.
* Since the msg is copied internally it can be allocated on stack.
* @nr: Number of elements in @vec.
* @data_len: length of data sent to/from server
* @sg: Pages to be sent/received to/from server.
* @sg_cnt: Number of elements in the @sg
*
* Return:
* 0: Success
* <0: Error
*
* On dir=READ rtrs client will request a data transfer from Server to client.
* The data that the server will respond with will be stored in @sg when
* the user receives an %RTRS_CLT_RDMA_EV_RDMA_REQUEST_WRITE_COMPL event.
* On dir=WRITE rtrs client will rdma write data in sg to server side.
*/
int rtrs_clt_request(int dir, struct rtrs_clt_req_ops *ops,
struct rtrs_clt *clt, struct rtrs_permit *permit,
const struct kvec *vec, size_t nr, size_t data_len,
struct scatterlist *sg, unsigned int sg_cnt)
{
struct rtrs_clt_io_req *req;
struct rtrs_clt_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 rtrs_msg_rdma_read) +
sg_cnt * sizeof(struct rtrs_sg_desc);
dma_dir = DMA_FROM_DEVICE;
} else {
hdr_len = sizeof(struct rtrs_msg_rdma_write);
dma_dir = DMA_TO_DEVICE;
}
rcu_read_lock();
for (path_it_init(&it, clt);
(sess = it.next_path(&it)) && it.i < it.clt->paths_num; it.i++) {
if (unlikely(READ_ONCE(sess->state) != RTRS_CLT_CONNECTED))
continue;
if (unlikely(usr_len + hdr_len > sess->max_hdr_size)) {
rtrs_wrn_rl(sess->clt,
"%s request failed, user message size is %zu and header length %zu, but max size is %u\n",
dir == READ ? "Read" : "Write",
usr_len, hdr_len, sess->max_hdr_size);
err = -EMSGSIZE;
break;
}
req = rtrs_clt_get_req(sess, ops->conf_fn, permit, ops->priv,
vec, usr_len, sg, sg_cnt, data_len,
dma_dir);
if (dir == READ)
err = rtrs_clt_read_req(req);
else
err = rtrs_clt_write_req(req);
if (unlikely(err)) {
req->in_use = false;
continue;
}
/* Success path */
break;
}
path_it_deinit(&it);
rcu_read_unlock();
return err;
}
EXPORT_SYMBOL(rtrs_clt_request);
/**
* rtrs_clt_query() - queries RTRS session attributes
*@clt: session pointer
*@attr: query results for session attributes.
* Returns:
* 0 on success
* -ECOMM no connection to the server
*/
int rtrs_clt_query(struct rtrs_clt *clt, struct rtrs_attrs *attr)
{
if (!rtrs_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(rtrs_clt_query);
int rtrs_clt_create_path_from_sysfs(struct rtrs_clt *clt,
struct rtrs_addr *addr)
{
struct rtrs_clt_sess *sess;
int err;
sess = alloc_sess(clt, addr, nr_cpu_ids, clt->max_segments,
clt->max_segment_size);
if (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.
*/
rtrs_clt_add_path_to_arr(sess, addr);
err = init_sess(sess);
if (err)
goto close_sess;
err = rtrs_clt_create_sess_files(sess);
if (err)
goto close_sess;
return 0;
close_sess:
rtrs_clt_remove_path_from_arr(sess);
rtrs_clt_close_conns(sess, true);
free_sess(sess);
return err;
}
static int rtrs_clt_ib_dev_init(struct rtrs_ib_dev *dev)
{
if (!(dev->ib_dev->attrs.device_cap_flags &
IB_DEVICE_MEM_MGT_EXTENSIONS)) {
pr_err("Memory registrations not supported.\n");
return -ENOTSUPP;
}
return 0;
}
static const struct rtrs_rdma_dev_pd_ops dev_pd_ops = {
.init = rtrs_clt_ib_dev_init
};
static int __init rtrs_client_init(void)
{
rtrs_rdma_dev_pd_init(0, &dev_pd);
rtrs_clt_dev_class = class_create(THIS_MODULE, "rtrs-client");
if (IS_ERR(rtrs_clt_dev_class)) {
pr_err("Failed to create rtrs-client dev class\n");
return PTR_ERR(rtrs_clt_dev_class);
}
rtrs_wq = alloc_workqueue("rtrs_client_wq", 0, 0);
if (!rtrs_wq) {
class_destroy(rtrs_clt_dev_class);
return -ENOMEM;
}
return 0;
}
static void __exit rtrs_client_exit(void)
{
destroy_workqueue(rtrs_wq);
class_destroy(rtrs_clt_dev_class);
rtrs_rdma_dev_pd_deinit(&dev_pd);
}
module_init(rtrs_client_init);
module_exit(rtrs_client_exit);
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