IB/hfi1: Fix deadlock with txreq allocation slow path
A failure in the get_txreq() inline will result in a
slow path retry using __get_txreq().
__get_txreq() attempts to procure the qp s_lock, which
is already held in all callers.
Fix by deleting the s_lock maintenance in __get_txreq()
and add sparse syntax hooks to future proof the code.
Cc: Stable <stable@vger.kernel.org> # 4.6+
Reviewed-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
diff --git a/drivers/infiniband/hw/hfi1/verbs_txreq.c b/drivers/infiniband/hw/hfi1/verbs_txreq.c
index bc95c41..d8fb056 100644
--- a/drivers/infiniband/hw/hfi1/verbs_txreq.c
+++ b/drivers/infiniband/hw/hfi1/verbs_txreq.c
@@ -92,11 +92,10 @@
struct verbs_txreq *__get_txreq(struct hfi1_ibdev *dev,
struct rvt_qp *qp)
+ __must_hold(&qp->s_lock)
{
struct verbs_txreq *tx = ERR_PTR(-EBUSY);
- unsigned long flags;
- spin_lock_irqsave(&qp->s_lock, flags);
write_seqlock(&dev->iowait_lock);
if (ib_rvt_state_ops[qp->state] & RVT_PROCESS_RECV_OK) {
struct hfi1_qp_priv *priv;
@@ -116,7 +115,6 @@
}
out:
write_sequnlock(&dev->iowait_lock);
- spin_unlock_irqrestore(&qp->s_lock, flags);
return tx;
}