[PATCH AUTOSEL 5.14 59/99] RDMA/rtrs-clt: Fix counting inflight IO

[PATCH AUTOSEL 5.14 59/99] RDMA/rtrs-clt: Fix counting inflight IO

[Sasha Levin]

From: Gioh Kim <gi-oh.kim@ionos.com>

[ Upstream commit 0d8f2cfa23f04ca01f6d4bba09933cb6310193aa ]

There are mis-match at counting inflight IO after changing the multipath
policy.

For example, we started fio test with round-robin policy and then we
changed the policy to min-inflight. IOs created under the RR policy is
finished under the min-inflight policy and inflight counter only
decreased. So the counter would be negative value.  And also we started
fio test with min-inflight policy and changed the policy to the
round-robin. IOs created under the min-inflight policy increased the
inflight IO counter but the inflight IO counter was not decreased because
the policy was the round-robin when IO was finished.

So it should count IOs only if the IO is created under the min-inflight
policy. It should not care the policy when the IO is finished.

This patch adds a field mp_policy in struct rtrs_clt_io_req and stores the
multipath policy when an object of rtrs_clt_io_req is created. Then
rtrs-clt checks the mp_policy of only struct rtrs_clt_io_req instead of
the struct rtrs_clt.

Link: https://lore.kernel.org/r/20210806112112.124313-6-haris.iqbal@ionos.com
Signed-off-by: Gioh Kim <gi-oh.kim@ionos.com>
Signed-off-by: Jack Wang <jinpu.wang@ionos.com>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Md Haris Iqbal <haris.iqbal@ionos.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/infiniband/ulp/rtrs/rtrs-clt-stats.c | 2 +-
 drivers/infiniband/ulp/rtrs/rtrs-clt.c       | 7 ++++---
 drivers/infiniband/ulp/rtrs/rtrs-clt.h       | 1 +
 3 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/infiniband/ulp/rtrs/rtrs-clt-stats.c b/drivers/infiniband/ulp/rtrs/rtrs-clt-stats.c
index 26bbe5d6dff5..553e173975fb 100644
--- a/drivers/infiniband/ulp/rtrs/rtrs-clt-stats.c
+++ b/drivers/infiniband/ulp/rtrs/rtrs-clt-stats.c
@@ -180,7 +180,7 @@ void rtrs_clt_update_all_stats(struct rtrs_clt_io_req *req, int dir)
 
 	len = req->usr_len + req->data_len;
 	rtrs_clt_update_rdma_stats(stats, len, dir);
-	if (sess->clt->mp_policy == MP_POLICY_MIN_INFLIGHT)
+	if (req->mp_policy == MP_POLICY_MIN_INFLIGHT)
 		atomic_inc(&stats->inflight);
 }
 
diff --git a/drivers/infiniband/ulp/rtrs/rtrs-clt.c b/drivers/infiniband/ulp/rtrs/rtrs-clt.c
index f2c40e50f25e..3b3bc77d02cc 100644
--- a/drivers/infiniband/ulp/rtrs/rtrs-clt.c
+++ b/drivers/infiniband/ulp/rtrs/rtrs-clt.c
@@ -438,7 +438,7 @@ static void complete_rdma_req(struct rtrs_clt_io_req *req, int errno,
 	}
 	if (!refcount_dec_and_test(&req->ref))
 		return;
-	if (sess->clt->mp_policy == MP_POLICY_MIN_INFLIGHT)
+	if (req->mp_policy == MP_POLICY_MIN_INFLIGHT)
 		atomic_dec(&sess->stats->inflight);
 
 	req->in_use = false;
@@ -963,6 +963,7 @@ static void rtrs_clt_init_req(struct rtrs_clt_io_req *req,
 	req->need_inv_comp = false;
 	req->inv_errno = 0;
 	refcount_set(&req->ref, 1);
+	req->mp_policy = sess->clt->mp_policy;
 
 	iov_iter_kvec(&iter, READ, vec, 1, usr_len);
 	len = _copy_from_iter(req->iu->buf, usr_len, &iter);
@@ -1153,7 +1154,7 @@ static int rtrs_clt_write_req(struct rtrs_clt_io_req *req)
 			    "Write request failed: error=%d path=%s [%s:%u]\n",
 			    ret, kobject_name(&sess->kobj), sess->hca_name,
 			    sess->hca_port);
-		if (sess->clt->mp_policy == MP_POLICY_MIN_INFLIGHT)
+		if (req->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,
@@ -1259,7 +1260,7 @@ static int rtrs_clt_read_req(struct rtrs_clt_io_req *req)
 			    "Read request failed: error=%d path=%s [%s:%u]\n",
 			    ret, kobject_name(&sess->kobj), sess->hca_name,
 			    sess->hca_port);
-		if (sess->clt->mp_policy == MP_POLICY_MIN_INFLIGHT)
+		if (req->mp_policy == MP_POLICY_MIN_INFLIGHT)
 			atomic_dec(&sess->stats->inflight);
 		req->need_inv = false;
 		if (req->sg_cnt)
diff --git a/drivers/infiniband/ulp/rtrs/rtrs-clt.h b/drivers/infiniband/ulp/rtrs/rtrs-clt.h
index e276a2dfcf7c..12eaea44c1f9 100644
--- a/drivers/infiniband/ulp/rtrs/rtrs-clt.h
+++ b/drivers/infiniband/ulp/rtrs/rtrs-clt.h
@@ -102,6 +102,7 @@ struct rtrs_clt_io_req {
 	unsigned int		usr_len;
 	void			*priv;
 	bool			in_use;
+	enum rtrs_mp_policy     mp_policy;
 	struct rtrs_clt_con	*con;
 	struct rtrs_sg_desc	*desc;
 	struct ib_sge		*sge;
-- 
2.30.2

[PATCH AUTOSEL 5.14 74/99] RDMA/core/sa_query: Retry SA queries

[Sasha Levin]

From: Håkon Bugge <haakon.bugge@oracle.com>

[ Upstream commit 5f5a650999d5718af766fc70a120230b04235a6f ]

A MAD packet is sent as an unreliable datagram (UD). SA requests are sent
as MAD packets. As such, SA requests or responses may be silently dropped.

IB Core's MAD layer has a timeout and retry mechanism, which amongst
other, is used by RDMA CM. But it is not used by SA queries. The lack of
retries of SA queries leads to long specified timeout, and error being
returned in case of packet loss. The ULP or user-land process has to
perform the retry.

Fix this by taking advantage of the MAD layer's retry mechanism.

First, a check against a zero timeout is added in rdma_resolve_route(). In
send_mad(), we set the MAD layer timeout to one tenth of the specified
timeout and the number of retries to 10. The special case when timeout is
less than 10 is handled.

With this fix:

 # ucmatose -c 1000 -S 1024 -C 1

runs stable on an Infiniband fabric. Without this fix, we see an
intermittent behavior and it errors out with:

cmatose: event: RDMA_CM_EVENT_ROUTE_ERROR, error: -110

(110 is ETIMEDOUT)

Link: https://lore.kernel.org/r/1628784755-28316-1-git-send-email-haakon.bugge@oracle.com
Signed-off-by: Håkon Bugge <haakon.bugge@oracle.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/infiniband/core/cma.c      | 3 +++
 drivers/infiniband/core/sa_query.c | 9 ++++++++-
 2 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/drivers/infiniband/core/cma.c b/drivers/infiniband/core/cma.c
index 5d3b8b8d163d..c40791baced5 100644
--- a/drivers/infiniband/core/cma.c
+++ b/drivers/infiniband/core/cma.c
@@ -3132,6 +3132,9 @@ int rdma_resolve_route(struct rdma_cm_id *id, unsigned long timeout_ms)
 	struct rdma_id_private *id_priv;
 	int ret;
 
+	if (!timeout_ms)
+		return -EINVAL;
+
 	id_priv = container_of(id, struct rdma_id_private, id);
 	if (!cma_comp_exch(id_priv, RDMA_CM_ADDR_RESOLVED, RDMA_CM_ROUTE_QUERY))
 		return -EINVAL;
diff --git a/drivers/infiniband/core/sa_query.c b/drivers/infiniband/core/sa_query.c
index b61576f702b8..5a560820f6e0 100644
--- a/drivers/infiniband/core/sa_query.c
+++ b/drivers/infiniband/core/sa_query.c
@@ -1358,6 +1358,7 @@ static int send_mad(struct ib_sa_query *query, unsigned long timeout_ms,
 {
 	unsigned long flags;
 	int ret, id;
+	const int nmbr_sa_query_retries = 10;
 
 	xa_lock_irqsave(&queries, flags);
 	ret = __xa_alloc(&queries, &id, query, xa_limit_32b, gfp_mask);
@@ -1365,7 +1366,13 @@ static int send_mad(struct ib_sa_query *query, unsigned long timeout_ms,
 	if (ret < 0)
 		return ret;
 
-	query->mad_buf->timeout_ms  = timeout_ms;
+	query->mad_buf->timeout_ms  = timeout_ms / nmbr_sa_query_retries;
+	query->mad_buf->retries = nmbr_sa_query_retries;
+	if (!query->mad_buf->timeout_ms) {
+		/* Special case, very small timeout_ms */
+		query->mad_buf->timeout_ms = 1;
+		query->mad_buf->retries = timeout_ms;
+	}
 	query->mad_buf->context[0] = query;
 	query->id = id;
 
-- 
2.30.2