[PATCH 3.14 51/73] srp-target: Retry when QP creation fails with ENOMEM

Greg Kroah-Hartman
2014-12-05T23:19:30Z

From: Bart Van Assche <bvanassche@acm.org>

commit ab477c1ff5e0a744c072404bf7db51bfe1f05b6e upstream.

It is not guaranteed to that srp_sq_size is supported
by the HCA. So if we failed to create the QP with ENOMEM,
try with a smaller srp_sq_size. Keep it up until we hit
MIN_SRPT_SQ_SIZE, then fail the connection.

Reported-by: Mark Lehrer <lehrer@gmail.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/infiniband/ulp/srpt/ib_srpt.c | 8 ++++++++
1 file changed, 8 insertions(+)

--- a/drivers/infiniband/ulp/srpt/ib_srpt.c
+++ b/drivers/infiniband/ulp/srpt/ib_srpt.c
@@ -2091,6 +2091,7 @@ static int srpt_create_ch_ib(struct srpt
if (!qp_init)
goto out;

+retry:
ch->cq = ib_create_cq(sdev->device, srpt_completion, NULL, ch,
ch->rq_size + srp_sq_size, 0);
if (IS_ERR(ch->cq)) {
@@ -2114,6 +2115,13 @@ static int srpt_create_ch_ib(struct srpt
ch->qp = ib_create_qp(sdev->pd, qp_init);
if (IS_ERR(ch->qp)) {
ret = PTR_ERR(ch->qp);
+ if (ret == -ENOMEM) {
+ srp_sq_size /= 2;
+ if (srp_sq_size >= MIN_SRPT_SQ_SIZE) {
+ ib_destroy_cq(ch->cq);
+ goto retry;
+ }
+ }
printk(KERN_ERR "failed to create_qp ret= %d\n", ret);
goto err_destroy_cq;
}