[PATCH net-next v4 04/27] skbuff: add SKBFL_DONT_ORPHAN flag

Pavel Begunkov
2022-07-07T11:52:20Z

We don't want to list every single ubuf_info callback in
skb_orphan_frags(), add a flag controlling the behaviour.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
---
include/linux/skbuff.h | 8 +++++---
net/core/skbuff.c | 2 +-
2 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index d3d10556f0fa..8e12b3b9ad6c 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -686,10 +686,13 @@ enum {
* charged to the kernel memory.
*/
SKBFL_PURE_ZEROCOPY = BIT(2),
+
+ SKBFL_DONT_ORPHAN = BIT(3),
};

#define SKBFL_ZEROCOPY_FRAG (SKBFL_ZEROCOPY_ENABLE | SKBFL_SHARED_FRAG)
-#define SKBFL_ALL_ZEROCOPY (SKBFL_ZEROCOPY_FRAG | SKBFL_PURE_ZEROCOPY)
+#define SKBFL_ALL_ZEROCOPY (SKBFL_ZEROCOPY_FRAG | SKBFL_PURE_ZEROCOPY | \
+ SKBFL_DONT_ORPHAN)

/*
* The callback notifies userspace to release buffers when skb DMA is done in
@@ -3182,8 +3185,7 @@ static inline int skb_orphan_frags(struct sk_buff *skb, gfp_t gfp_mask)
{
if (likely(!skb_zcopy(skb)))
return 0;
- if (!skb_zcopy_is_nouarg(skb) &&
- skb_uarg(skb)->callback == msg_zerocopy_callback)
+ if (skb_shinfo(skb)->flags & SKBFL_DONT_ORPHAN)
return 0;
return skb_copy_ubufs(skb, gfp_mask);
}
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 09f56bfa2771..fc22b3d32052 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -1193,7 +1193,7 @@ static struct ubuf_info *msg_zerocopy_alloc(struct sock *sk, size_t size)
uarg->len = 1;
uarg->bytelen = size;
uarg->zerocopy = 1;
- uarg->flags = SKBFL_ZEROCOPY_FRAG;
+ uarg->flags = SKBFL_ZEROCOPY_FRAG | SKBFL_DONT_ORPHAN;
refcount_set(&uarg->refcnt, 1);
sock_hold(sk);

--
2.36.1