A quote from the IB spec:
However, if the Consumer does not wait for the Affiliated Asynchronous
Last WQE Reached Event, then WQE and Data Segment leakage may occur.
Therefore, it is good programming practice to tear down a QP that is
associated with an SRQ by using the following process:
* Put the QP in the Error State;
* wait for the Affiliated Asynchronous Last WQE Reached Event;
* either:
* drain the CQ by invoking the Poll CQ verb and either wait for CQ
to be empty or the number of Poll CQ operations has exceeded CQ
capacity size; or
* post another WR that completes on the same CQ and wait for this WR to return as a WC;
* and then invoke a Destroy QP or Reset QP.
Signed-off-by: Bart Van Assche <bart.vanassche@xxxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Cc: Israel Rukshin <israelr@xxxxxxxxxxxx>
Cc: Max Gurtovoy <maxg@xxxxxxxxxxxx>
Cc: Laurence Oberman <loberman@xxxxxxxxxx>
---
drivers/infiniband/ulp/srp/ib_srp.c | 19 ++++++++++++++-----
1 file changed, 14 insertions(+), 5 deletions(-)
diff --git a/drivers/infiniband/ulp/srp/ib_srp.c b/drivers/infiniband/ulp/srp/ib_srp.c
index 2f85255d2aca..b50733910f7e 100644
--- a/drivers/infiniband/ulp/srp/ib_srp.c
+++ b/drivers/infiniband/ulp/srp/ib_srp.c
@@ -471,9 +471,13 @@ static struct srp_fr_pool *srp_alloc_fr_pool(struct srp_target_port *target)
* completion handler can access the queue pair while it is
* being destroyed.
*/
-static void srp_destroy_qp(struct ib_qp *qp)
+static void srp_destroy_qp(struct srp_rdma_ch *ch, struct ib_qp *qp)
{
- ib_drain_rq(qp);
+ spin_lock_irq(&ch->lock);
+ ib_process_cq_direct(ch->send_cq, -1);
+ spin_unlock_irq(&ch->lock);
+
+ ib_drain_qp(qp);
ib_destroy_qp(qp);
}
@@ -547,7 +551,7 @@ static int srp_create_ch_ib(struct srp_rdma_ch *ch)
}
if (ch->qp)
- srp_destroy_qp(ch->qp);
+ srp_destroy_qp(ch, ch->qp);
if (ch->recv_cq)
ib_free_cq(ch->recv_cq);
if (ch->send_cq)
@@ -571,7 +575,7 @@ static int srp_create_ch_ib(struct srp_rdma_ch *ch)
return 0;
err_qp:
- srp_destroy_qp(qp);
+ srp_destroy_qp(ch, qp);
err_send_cq:
ib_free_cq(send_cq);
@@ -614,7 +618,7 @@ static void srp_free_ch_ib(struct srp_target_port *target,
ib_destroy_fmr_pool(ch->fmr_pool);
}
- srp_destroy_qp(ch->qp);
+ srp_destroy_qp(ch, ch->qp);
ib_free_cq(ch->send_cq);
ib_free_cq(ch->recv_cq);
@@ -1827,6 +1831,11 @@ static struct srp_iu *__srp_get_tx_iu(struct srp_rdma_ch *ch,
return iu;
}
+/*
+ * Note: if this function is called from inside ib_drain_sq() then it will
+ * be called without ch->lock being held. If ib_drain_sq() dequeues a WQE
+ * with status IB_WC_SUCCESS then that's a bug.
+ */
static void srp_send_done(struct ib_cq *cq, struct ib_wc *wc)
{
struct srp_iu *iu = container_of(wc->wr_cqe, struct srp_iu, cqe);
--
2.11.0
--
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