IB/IPoIB: Convert IPoIB to memalloc_noio_* calls

Commit 21caf2fc1931 ("mm: teach mm by current context info to not do I/O
during memory allocation") added the memalloc_noio_(save|restore) functions
to enable people to modify the MM behavior by disabling I/O during memory
allocation. This was further extended in Fixes: 934f3072c17c ("mm: clear
__GFP_FS when PF_MEMALLOC_NOIO is set"). memalloc_noio_* functions prevent
allocation paths recursing back into the filesystem without explicitly
changing the flags for every allocation site.

However the IPoIB hasn't been keeping up with the changes and missed
completely these memalloc_noio_* calls. This led to update of
allocation site with special QP creation flag, see commit 09b93088d750
("IB: Add a QP creation flag to use GFP_NOIO allocations"), while this
flag is supported by small number of drivers in IB stack.

Let's change it by updating to memalloc_noio_* calls and allow
for every driver underneath enjoy NOIO allocations.

Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Reviewed-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

drivers/infiniband/ulp/ipoib/ipoib_cm.c

@@ -39,6 +39,7 @@
 #include <linux/vmalloc.h>
 #include <linux/moduleparam.h>
 #include <linux/sched/signal.h>
+#include <linux/sched/mm.h>
 
 #include "ipoib.h"
 
@@ -1047,9 +1048,8 @@ static struct ib_qp *ipoib_cm_create_tx_qp(struct net_device *dev, struct ipoib_
 		.sq_sig_type		= IB_SIGNAL_ALL_WR,
 		.qp_type		= IB_QPT_RC,
 		.qp_context		= tx,
-		.create_flags		= IB_QP_CREATE_USE_GFP_NOIO
+		.create_flags		= 0
 	};
-
 	struct ib_qp *tx_qp;
 
 	if (dev->features & NETIF_F_SG)
@@ -1057,10 +1057,6 @@ static struct ib_qp *ipoib_cm_create_tx_qp(struct net_device *dev, struct ipoib_
 			min_t(u32, priv->ca->attrs.max_sge, MAX_SKB_FRAGS + 1);
 
 	tx_qp = ib_create_qp(priv->pd, &attr);
-	if (PTR_ERR(tx_qp) == -EINVAL) {
-		attr.create_flags &= ~IB_QP_CREATE_USE_GFP_NOIO;
-		tx_qp = ib_create_qp(priv->pd, &attr);
-	}
 	tx->max_send_sge = attr.cap.max_send_sge;
 	return tx_qp;
 }
@@ -1131,10 +1127,11 @@ static int ipoib_cm_tx_init(struct ipoib_cm_tx *p, u32 qpn,
 			    struct sa_path_rec *pathrec)
 {
 	struct ipoib_dev_priv *priv = ipoib_priv(p->dev);
+	unsigned int noio_flag;
 	int ret;
 
-	p->tx_ring = __vmalloc(ipoib_sendq_size * sizeof *p->tx_ring,
-			       GFP_NOIO, PAGE_KERNEL);
+	noio_flag = memalloc_noio_save();
+	p->tx_ring = vzalloc(ipoib_sendq_size * sizeof(*p->tx_ring));
 	if (!p->tx_ring) {
 		ret = -ENOMEM;
 		goto err_tx;
@@ -1142,9 +1139,10 @@ static int ipoib_cm_tx_init(struct ipoib_cm_tx *p, u32 qpn,
 	memset(p->tx_ring, 0, ipoib_sendq_size * sizeof *p->tx_ring);
 
 	p->qp = ipoib_cm_create_tx_qp(p->dev, p);
+	memalloc_noio_restore(noio_flag);
 	if (IS_ERR(p->qp)) {
 		ret = PTR_ERR(p->qp);
-		ipoib_warn(priv, "failed to allocate tx qp: %d\n", ret);
+		ipoib_warn(priv, "failed to create tx qp: %d\n", ret);
 		goto err_qp;
 	}