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 4850d03870c297667e65c96b50d5ccec50b5aa01..35275099cafd660cd2fc20ab865d08c417f51735 100644 (file)
--- 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];
                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);
                        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;
                        }
                                break;
                        }

-                       q = rcu_dereference_protected(*qpp,
-                               lockdep_is_held(&dev->qpt_lock));
-               }

        }
 
        spin_unlock_irqrestore(&dev->qpt_lock, flags);
        }
 
        spin_unlock_irqrestore(&dev->qpt_lock, flags);