Subject: [RFC PATCH v3 11/12] skbuff: add flags to ubuf_info for ubuf setup

From: Jonathan Lemon <[email-masked]>
Date: Wed, 30 Dec 2020 11:12:43 -0800

From: Jonathan Lemon <[email-masked]>

Currently, when an ubuf is attached to a new skb, the shared
flags word is initialized to a fixed value.  Instead of doing
this, set the default flags in the ubuf, and have new skbs
inherit from this default.

This is needed when setting up different zerocopy types.

Signed-off-by: Jonathan Lemon <[email-masked]>
---
 include/linux/skbuff.h | 3 ++-
 net/core/skbuff.c      | 1 +
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 66fde9a7b851..58010df9d183 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -480,6 +480,7 @@ struct ubuf_info {
 		};
 	};
 	refcount_t refcnt;
+	u8 flags;
 
 	struct mmpin {
 		struct user_struct *user;
@@ -1456,7 +1457,7 @@ static inline void skb_zcopy_set(struct sk_buff *skb, struct ubuf_info *uarg,
 		else
 			skb_zcopy_get(uarg);
 		skb_shinfo(skb)->destructor_arg = uarg;
-		skb_shinfo(skb)->flags |= SKBFL_ZEROCOPY_FRAG;
+		skb_shinfo(skb)->flags |= uarg->flags;
 	}
 }
 
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 124e4752afb6..ee288af095f0 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -1119,6 +1119,7 @@ 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;
 	refcount_set(&uarg->refcnt, 1);
 	sock_hold(sk);
 
-- 
2.24.1