[PATCH 5.15 079/121] net: introduce __skb_fill_page_desc_noacc

From: Greg Kroah-Hartman
Date: Tue Sep 13 2022 - 10:38:26 EST


From: Pavel Begunkov <asml.silence@xxxxxxxxx>

[ Upstream commit 84ce071e38a6e25ea3ea91188e5482ac1f17b3af ]

Managed pages contain pinned userspace pages and controlled by upper
layers, there is no need in tracking skb->pfmemalloc for them. Introduce
a helper for filling frags but ignoring page tracking, it'll be needed
later.

Signed-off-by: Pavel Begunkov <asml.silence@xxxxxxxxx>
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
include/linux/skbuff.h | 28 +++++++++++++++++-----------
1 file changed, 17 insertions(+), 11 deletions(-)

diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index ae598ed86b50b..be7cc31d58961 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -2232,6 +2232,22 @@ static inline unsigned int skb_pagelen(const struct sk_buff *skb)
return skb_headlen(skb) + __skb_pagelen(skb);
}

+static inline void __skb_fill_page_desc_noacc(struct skb_shared_info *shinfo,
+ int i, struct page *page,
+ int off, int size)
+{
+ skb_frag_t *frag = &shinfo->frags[i];
+
+ /*
+ * Propagate page pfmemalloc to the skb if we can. The problem is
+ * that not all callers have unique ownership of the page but rely
+ * on page_is_pfmemalloc doing the right thing(tm).
+ */
+ frag->bv_page = page;
+ frag->bv_offset = off;
+ skb_frag_size_set(frag, size);
+}
+
/**
* __skb_fill_page_desc - initialise a paged fragment in an skb
* @skb: buffer containing fragment to be initialised
@@ -2248,17 +2264,7 @@ static inline unsigned int skb_pagelen(const struct sk_buff *skb)
static inline void __skb_fill_page_desc(struct sk_buff *skb, int i,
struct page *page, int off, int size)
{
- skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
-
- /*
- * Propagate page pfmemalloc to the skb if we can. The problem is
- * that not all callers have unique ownership of the page but rely
- * on page_is_pfmemalloc doing the right thing(tm).
- */
- frag->bv_page = page;
- frag->bv_offset = off;
- skb_frag_size_set(frag, size);
-
+ __skb_fill_page_desc_noacc(skb_shinfo(skb), i, page, off, size);
page = compound_head(page);
if (page_is_pfmemalloc(page))
skb->pfmemalloc = true;
--
2.35.1