diff mbox series

[net,v3,3/4] tcp: refactor tcp_read_skb() a bit

Message ID 20220817195445.151609-4-xiyou.wangcong@gmail.com (mailing list archive)
State Accepted
Commit a8688821f3854f37fe0198b8945f9cfc051ab2cf
Delegated to: Netdev Maintainers
Headers show
Series tcp: some bug fixes for tcp_read_skb() | expand

Checks

Context Check Description
netdev/tree_selection success Clearly marked for net
netdev/fixes_present success Fixes tag present in non-next series
netdev/subject_prefix success Link
netdev/cover_letter success Series has a cover letter
netdev/patch_count success Link
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 342 this patch: 342
netdev/cc_maintainers warning 5 maintainers not CCed: yoshfuji@linux-ipv6.org davem@davemloft.net dsahern@kernel.org kuba@kernel.org pabeni@redhat.com
netdev/build_clang success Errors and warnings before: 5 this patch: 5
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 342 this patch: 342
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 34 lines checked
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Cong Wang Aug. 17, 2022, 7:54 p.m. UTC 
From: Cong Wang <cong.wang@bytedance.com>

As tcp_read_skb() only reads one skb at a time, the while loop is
unnecessary, we can turn it into an if. This also simplifies the
code logic.

Cc: Eric Dumazet <edumazet@google.com>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: Jakub Sitnicki <jakub@cloudflare.com>
Signed-off-by: Cong Wang <cong.wang@bytedance.com>
---
 net/ipv4/tcp.c | 26 +++++++++-----------------
 1 file changed, 9 insertions(+), 17 deletions(-)
diff mbox series

Patch

diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 181a0d350123..56a554b49caa 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -1761,25 +1761,17 @@  int tcp_read_skb(struct sock *sk, skb_read_actor_t recv_actor)
 	if (sk->sk_state == TCP_LISTEN)
 		return -ENOTCONN;
 
-	while ((skb = tcp_recv_skb(sk, seq, &offset)) != NULL) {
-		int used;
-
-		__skb_unlink(skb, &sk->sk_receive_queue);
-		WARN_ON(!skb_set_owner_sk_safe(skb, sk));
-		used = recv_actor(sk, skb);
-		if (used <= 0) {
-			if (!copied)
-				copied = used;
-			break;
-		}
-		seq += used;
-		copied += used;
+	skb = tcp_recv_skb(sk, seq, &offset);
+	if (!skb)
+		return 0;
 
-		if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN) {
+	__skb_unlink(skb, &sk->sk_receive_queue);
+	WARN_ON(!skb_set_owner_sk_safe(skb, sk));
+	copied = recv_actor(sk, skb);
+	if (copied > 0) {
+		seq += copied;
+		if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)
 			++seq;
-			break;
-		}
-		break;
 	}
 	consume_skb(skb);
 	WRITE_ONCE(tp->copied_seq, seq);