From: Mike Marciniszyn <mike.marciniszyn@intel.com>
Date: Thu, 24 Jan 2013 18:59:34 +0000 (+0000)
Subject: IB/qib: Fix for broken sparse warning fix
X-Git-Tag: v3.8-rc7~5^2^3
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=d359f35430c4ea4dd4e24d809aeaeff1fa54c314;p=platform%2Fkernel%2Flinux-stable.git

IB/qib: Fix for broken sparse warning fix

Commit 1fb9fed6d489 ("IB/qib: Fix QP RCU sparse warning") broke QP
hash list deletion in qp_remove() badly.

This patch restores the former for loop behavior, while still fixing
the sparse warnings.

Cc: <stable@vger.kernel.org>
Reviewed-by: Gary Leshner <gary.s.leshner@intel.com>
Signed-off-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
---

diff --git a/drivers/infiniband/hw/qib/qib_qp.c b/drivers/infiniband/hw/qib/qib_qp.c
index 4850d03..3527509 100644
--- a/drivers/infiniband/hw/qib/qib_qp.c
+++ b/drivers/infiniband/hw/qib/qib_qp.c
@@ -263,20 +263,15 @@ static void remove_qp(struct qib_ibdev *dev, struct qib_qp *qp)
 		struct qib_qp __rcu **qpp;
 
 		qpp = &dev->qp_table[n];
-		q = rcu_dereference_protected(*qpp,
-			lockdep_is_held(&dev->qpt_lock));
-		for (; q; qpp = &q->next) {
+		for (; (q = rcu_dereference_protected(*qpp,
+				lockdep_is_held(&dev->qpt_lock))) != NULL;
+				qpp = &q->next)
 			if (q == qp) {
 				atomic_dec(&qp->refcount);
 				*qpp = qp->next;
 				rcu_assign_pointer(qp->next, NULL);
-				q = rcu_dereference_protected(*qpp,
-					lockdep_is_held(&dev->qpt_lock));
 				break;
 			}
-			q = rcu_dereference_protected(*qpp,
-				lockdep_is_held(&dev->qpt_lock));
-		}
 	}
 
 	spin_unlock_irqrestore(&dev->qpt_lock, flags);