[PATCH net-next v2 1/2] gtp: remove unnecessary rcu_read_lock

[Andreas Schultz]

The rcu read lock is hold by default in the ip input path. There
is no need to hold it twice in the socket recv decapsulate code path.

Signed-off-by: Andreas Schultz <aschu...@tpip.net>
---
 drivers/net/gtp.c | 24 ++++--------------------
 1 file changed, 4 insertions(+), 20 deletions(-)

diff --git a/drivers/net/gtp.c b/drivers/net/gtp.c
index 8b6810b..5c63a37 100644
--- a/drivers/net/gtp.c
+++ b/drivers/net/gtp.c
@@ -184,7 +184,6 @@ static int gtp0_udp_encap_recv(struct gtp_dev *gtp, struct 
sk_buff *skb,
                              sizeof(struct gtp0_header);
        struct gtp0_header *gtp0;
        struct pdp_ctx *pctx;
-       int ret = 0;
 
        if (!pskb_may_pull(skb, hdrlen))
                return -1;
@@ -197,26 +196,19 @@ static int gtp0_udp_encap_recv(struct gtp_dev *gtp, 
struct sk_buff *skb,
        if (gtp0->type != GTP_TPDU)
                return 1;
 
-       rcu_read_lock();
        pctx = gtp0_pdp_find(gtp, be64_to_cpu(gtp0->tid));
        if (!pctx) {
                netdev_dbg(gtp->dev, "No PDP ctx to decap skb=%p\n", skb);
-               ret = -1;
-               goto out_rcu;
+               return -1;
        }
 
        if (!gtp_check_src_ms(skb, pctx, hdrlen)) {
                netdev_dbg(gtp->dev, "No PDP ctx for this MS\n");
-               ret = -1;
-               goto out_rcu;
+               return -1;
        }
-       rcu_read_unlock();
 
        /* Get rid of the GTP + UDP headers. */
        return iptunnel_pull_header(skb, hdrlen, skb->protocol, xnet);
-out_rcu:
-       rcu_read_unlock();
-       return ret;
 }
 
 static int gtp1u_udp_encap_recv(struct gtp_dev *gtp, struct sk_buff *skb,
@@ -226,7 +218,6 @@ static int gtp1u_udp_encap_recv(struct gtp_dev *gtp, struct 
sk_buff *skb,
                              sizeof(struct gtp1_header);
        struct gtp1_header *gtp1;
        struct pdp_ctx *pctx;
-       int ret = 0;
 
        if (!pskb_may_pull(skb, hdrlen))
                return -1;
@@ -254,26 +245,19 @@ static int gtp1u_udp_encap_recv(struct gtp_dev *gtp, 
struct sk_buff *skb,
 
        gtp1 = (struct gtp1_header *)(skb->data + sizeof(struct udphdr));
 
-       rcu_read_lock();
        pctx = gtp1_pdp_find(gtp, ntohl(gtp1->tid));
        if (!pctx) {
                netdev_dbg(gtp->dev, "No PDP ctx to decap skb=%p\n", skb);
-               ret = -1;
-               goto out_rcu;
+               return -1;
        }
 
        if (!gtp_check_src_ms(skb, pctx, hdrlen)) {
                netdev_dbg(gtp->dev, "No PDP ctx for this MS\n");
-               ret = -1;
-               goto out_rcu;
+               return -1;
        }
-       rcu_read_unlock();
 
        /* Get rid of the GTP + UDP headers. */
        return iptunnel_pull_header(skb, hdrlen, skb->protocol, xnet);
-out_rcu:
-       rcu_read_unlock();
-       return ret;
 }
 
 static void gtp_encap_disable(struct gtp_dev *gtp)
-- 
2.10.2