From: Or Gerlitz <ogerlitz@mellanox.com>
Date: Sun, 29 Apr 2012 14:04:22 +0000 (+0300)
Subject: IB/core: Use qp->usecnt to track multicast attach/detach
X-Git-Tag: v3.5-rc1~171^2~3
X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=c3bccbfbb71f5e8a77129c7a069f5c5648cc9cf1;p=linux.git

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 575b78045aaf..c5b94d647e1e 100644
--- a/drivers/infiniband/core/verbs.c
+++ b/drivers/infiniband/core/verbs.c
@@ -1183,23 +1183,33 @@ EXPORT_SYMBOL(ib_dealloc_fmr);
 
 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 c3cca5a4dacd..c84d1016618e 100644
--- a/include/rdma/ib_verbs.h
+++ b/include/rdma/ib_verbs.h
@@ -964,7 +964,7 @@ struct ib_qp {
 	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;