IB/core: Use qp->usecnt to track multicast attach/detach
Just as we don't allow PDs, CQs, etc. to be destroyed if there are QPs
that are attached to them, don't let a QP be destroyed if there are
multicast group(s) attached to it. Use the existing usecnt field of
struct ib_qp which was added by commit 0e0ec7e ("RDMA/core: Export
ib_open_qp() to share XRC TGT QPs") to track this.
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
diff --git a/drivers/infiniband/core/verbs.c b/drivers/infiniband/core/verbs.c
index 575b780..c5b94d6 100644
--- a/drivers/infiniband/core/verbs.c
+++ b/drivers/infiniband/core/verbs.c
@@ -1183,23 +1183,33 @@
int ib_attach_mcast(struct ib_qp *qp, union ib_gid *gid, u16 lid)
{
+ int ret;
+
if (!qp->device->attach_mcast)
return -ENOSYS;
if (gid->raw[0] != 0xff || qp->qp_type != IB_QPT_UD)
return -EINVAL;
- return qp->device->attach_mcast(qp, gid, lid);
+ ret = qp->device->attach_mcast(qp, gid, lid);
+ if (!ret)
+ atomic_inc(&qp->usecnt);
+ return ret;
}
EXPORT_SYMBOL(ib_attach_mcast);
int ib_detach_mcast(struct ib_qp *qp, union ib_gid *gid, u16 lid)
{
+ int ret;
+
if (!qp->device->detach_mcast)
return -ENOSYS;
if (gid->raw[0] != 0xff || qp->qp_type != IB_QPT_UD)
return -EINVAL;
- return qp->device->detach_mcast(qp, gid, lid);
+ ret = qp->device->detach_mcast(qp, gid, lid);
+ if (!ret)
+ atomic_dec(&qp->usecnt);
+ return ret;
}
EXPORT_SYMBOL(ib_detach_mcast);
diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h
index c3cca5a..c84d101 100644
--- a/include/rdma/ib_verbs.h
+++ b/include/rdma/ib_verbs.h
@@ -964,7 +964,7 @@
struct ib_srq *srq;
struct ib_xrcd *xrcd; /* XRC TGT QPs only */
struct list_head xrcd_list;
- atomic_t usecnt; /* count times opened */
+ atomic_t usecnt; /* count times opened, mcast attaches */
struct list_head open_list;
struct ib_qp *real_qp;
struct ib_uobject *uobject;