From: Julian Wiedmann jwi@linux.ibm.com
[ Upstream commit 238965b71b968dc5b3c0fe430e946f488322c4b5 ]
The HiperSockets-based transport path in af_iucv is still too closely entangled with qeth. With commit a647a02512ca ("s390/qeth: speed-up L3 IQD xmit"), the relevant xmit code in qeth has begun to use skb_cow_head(). So to avoid unnecessary skb head expansions, af_iucv must learn to 1) respect dev->needed_headroom when allocating skbs, and 2) drop the header reference before cloning the skb.
While at it, also stop hard-coding the LL-header creation stage and just use the appropriate helper.
Fixes: a647a02512ca ("s390/qeth: speed-up L3 IQD xmit") Signed-off-by: Julian Wiedmann jwi@linux.ibm.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- net/iucv/af_iucv.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-)
diff --git a/net/iucv/af_iucv.c b/net/iucv/af_iucv.c index f024914da1b2..e07daee1227c 100644 --- a/net/iucv/af_iucv.c +++ b/net/iucv/af_iucv.c @@ -13,6 +13,7 @@ #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
#include <linux/module.h> +#include <linux/netdevice.h> #include <linux/types.h> #include <linux/list.h> #include <linux/errno.h> @@ -355,6 +356,9 @@ static int afiucv_hs_send(struct iucv_message *imsg, struct sock *sock, err = -ENODEV; goto err_free; } + + dev_hard_header(skb, skb->dev, ETH_P_AF_IUCV, NULL, NULL, skb->len); + if (!(skb->dev->flags & IFF_UP) || !netif_carrier_ok(skb->dev)) { err = -ENETDOWN; goto err_free; @@ -367,6 +371,8 @@ static int afiucv_hs_send(struct iucv_message *imsg, struct sock *sock, skb_trim(skb, skb->dev->mtu); } skb->protocol = cpu_to_be16(ETH_P_AF_IUCV); + + __skb_header_release(skb); nskb = skb_clone(skb, GFP_ATOMIC); if (!nskb) { err = -ENOMEM; @@ -466,12 +472,14 @@ static void iucv_sever_path(struct sock *sk, int with_user_data) /* Send controlling flags through an IUCV socket for HIPER transport */ static int iucv_send_ctrl(struct sock *sk, u8 flags) { + struct iucv_sock *iucv = iucv_sk(sk); int err = 0; int blen; struct sk_buff *skb; u8 shutdown = 0;
- blen = sizeof(struct af_iucv_trans_hdr) + ETH_HLEN; + blen = sizeof(struct af_iucv_trans_hdr) + + LL_RESERVED_SPACE(iucv->hs_dev); if (sk->sk_shutdown & SEND_SHUTDOWN) { /* controlling flags should be sent anyway */ shutdown = sk->sk_shutdown; @@ -1131,7 +1139,8 @@ static int iucv_sock_sendmsg(struct socket *sock, struct msghdr *msg, * segmented records using the MSG_EOR flag), but * for SOCK_STREAM we might want to improve it in future */ if (iucv->transport == AF_IUCV_TRANS_HIPER) { - headroom = sizeof(struct af_iucv_trans_hdr) + ETH_HLEN; + headroom = sizeof(struct af_iucv_trans_hdr) + + LL_RESERVED_SPACE(iucv->hs_dev); linear = len; } else { if (len < PAGE_SIZE) {