netvm: propagate page->pfmemalloc from skb_alloc_page to skb

The skb->pfmemalloc flag gets set to true iff during the slab allocation
of data in __alloc_skb that the the PFMEMALLOC reserves were used.  If
page splitting is used, it is possible that pages will be allocated from
the PFMEMALLOC reserve without propagating this information to the skb.
This patch propagates page->pfmemalloc from pages allocated for fragments
to the skb.

It works by reintroducing and expanding the skb_alloc_page() API to take
an skb.  If the page was allocated from pfmemalloc reserves, it is
automatically copied.  If the driver allocates the page before the skb, it
should call skb_propagate_pfmemalloc() after the skb is allocated to
ensure the flag is copied properly.

Failure to do so is not critical.  The resulting driver may perform slower
if it is used for swap-over-NBD or swap-over-NFS but it should not result
in failure.

[davem@davemloft.net: API rename and consistency]
Signed-off-by: Mel Gorman <mgorman@suse.de>
Acked-by: David S. Miller <davem@davemloft.net>
Cc: Neil Brown <neilb@suse.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Christie <michaelc@cs.wisc.edu>
Cc: Eric B Munson <emunson@mgebm.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Sebastian Andrzej Siewior <sebastian@breakpoint.cc>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Christoph Lameter <cl@linux.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

6 files changed, 6 insertions, 7 deletions

diff --git a/drivers/net/ethernet/chelsio/cxgb4/sge.c b/drivers/net/ethernet/chelsio/cxgb4/sge.c
index 8596acaa402b..d49933ed551f 100644
--- a/drivers/net/ethernet/chelsio/cxgb4/sge.c
+++ b/drivers/net/ethernet/chelsio/cxgb4/sge.c
@@ -528,7 +528,7 @@ static unsigned int refill_fl(struct adapter *adap, struct sge_fl *q, int n,
 #endif
 
         while (n--) {
-                pg = alloc_page(gfp);
+                pg = __skb_alloc_page(gfp, NULL);
                 if (unlikely(!pg)) {
                         q->alloc_failed++;
                         break;
diff --git a/drivers/net/ethernet/chelsio/cxgb4vf/sge.c b/drivers/net/ethernet/chelsio/cxgb4vf/sge.c
index f2d1ecdcaf98..8877fbfefb63 100644
--- a/drivers/net/ethernet/chelsio/cxgb4vf/sge.c
+++ b/drivers/net/ethernet/chelsio/cxgb4vf/sge.c
@@ -653,7 +653,7 @@ static unsigned int refill_fl(struct adapter *adapter, struct sge_fl *fl,
 
 alloc_small_pages:
         while (n--) {
-                page = alloc_page(gfp | __GFP_NOWARN | __GFP_COLD);
+                page = __skb_alloc_page(gfp | __GFP_NOWARN, NULL);
                 if (unlikely(!page)) {
                         fl->alloc_failed++;
                         break;
diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c
index 1050411e7ca3..b7c2d5050572 100644
--- a/drivers/net/ethernet/intel/igb/igb_main.c
+++ b/drivers/net/ethernet/intel/igb/igb_main.c
@@ -6235,7 +6235,7 @@ static bool igb_alloc_mapped_page(struct igb_ring *rx_ring,
                 return true;
 
         if (!page) {
-                page = alloc_page(GFP_ATOMIC | __GFP_COLD);
+                page = __skb_alloc_page(GFP_ATOMIC, bi->skb);
                 bi->page = page;
                 if (unlikely(!page)) {
                         rx_ring->rx_stats.alloc_failed++;
diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
index c709eae58c63..4326f74f7137 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
@@ -1141,8 +1141,8 @@ static bool ixgbe_alloc_mapped_page(struct ixgbe_ring *rx_ring,
 
         /* alloc new page for storage */
         if (likely(!page)) {
-                page = alloc_pages(GFP_ATOMIC | __GFP_COLD | __GFP_COMP,
-                                   ixgbe_rx_pg_order(rx_ring));
+                page = __skb_alloc_pages(GFP_ATOMIC | __GFP_COLD | __GFP_COMP,
+                                         bi->skb, ixgbe_rx_pg_order(rx_ring));
                 if (unlikely(!page)) {
                         rx_ring->rx_stats.alloc_rx_page_failed++;
                         return false;
diff --git a/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c b/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
index 3f9841d619ad..60ef64587412 100644
--- a/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
+++ b/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
@@ -352,7 +352,6 @@ static void ixgbevf_alloc_rx_buffers(struct ixgbevf_adapter *adapter,
                                 adapter->alloc_rx_buff_failed++;
                                 goto no_buffers;
                         }
-
                         bi->skb = skb;
                 }
                 if (!bi->dma) {
diff --git a/drivers/net/usb/cdc-phonet.c b/drivers/net/usb/cdc-phonet.c
index 187c144c5e5b..64610048ce87 100644
--- a/drivers/net/usb/cdc-phonet.c
+++ b/drivers/net/usb/cdc-phonet.c
@@ -130,7 +130,7 @@ static int rx_submit(struct usbpn_dev *pnd, struct urb *req, gfp_t gfp_flags)
         struct page *page;
         int err;
 
-        page = alloc_page(gfp_flags);
+        page = __skb_alloc_page(gfp_flags | __GFP_NOMEMALLOC, NULL);
         if (!page)
                 return -ENOMEM;