tcp: add gfp parameter to tcp_fragment

tcp_fragment can be called from process context (from tso_fragment).
Add a new gfp parameter to allow it to preserve atomic memory if
possible.

Signed-off-by: Octavian Purdila <octavian.purdila@intel.com>
Reviewed-by: Christoph Paasch <christoph.paasch@uclouvain.be>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 11 insertions, 9 deletions

diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 931529d5daa2..40661fc1e233 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -1167,7 +1167,7 @@ static int tcp_match_skb_to_sack(struct sock *sk, struct sk_buff *skb,
                         }
                         pkt_len = new_len;
                 }
-                err = tcp_fragment(sk, skb, pkt_len, mss);
+                err = tcp_fragment(sk, skb, pkt_len, mss, GFP_ATOMIC);
                 if (err < 0)
                         return err;
         }
@@ -2241,7 +2241,8 @@ static void tcp_mark_head_lost(struct sock *sk, int packets, int mark_head)
                                 break;
 
                         mss = skb_shinfo(skb)->gso_size;
-                        err = tcp_fragment(sk, skb, (packets - oldcnt) * mss, mss);
+                        err = tcp_fragment(sk, skb, (packets - oldcnt) * mss,
+                                           mss, GFP_ATOMIC);
                         if (err < 0)
                                 break;
                         cnt = packets;
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index d463c35db33d..ad7549f1d0ad 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -1074,7 +1074,7 @@ static void tcp_adjust_pcount(struct sock *sk, const struct sk_buff *skb, int de
  * Remember, these are still headerless SKBs at this point.
  */
 int tcp_fragment(struct sock *sk, struct sk_buff *skb, u32 len,
-                 unsigned int mss_now)
+                 unsigned int mss_now, gfp_t gfp)
 {
         struct tcp_sock *tp = tcp_sk(sk);
         struct sk_buff *buff;
@@ -1089,11 +1089,11 @@ int tcp_fragment(struct sock *sk, struct sk_buff *skb, u32 len,
         if (nsize < 0)
                 nsize = 0;
 
-        if (skb_unclone(skb, GFP_ATOMIC))
+        if (skb_unclone(skb, gfp))
                 return -ENOMEM;
 
         /* Get a new skb... force flag on. */
-        buff = sk_stream_alloc_skb(sk, nsize, GFP_ATOMIC);
+        buff = sk_stream_alloc_skb(sk, nsize, gfp);
         if (buff == NULL)
                 return -ENOMEM; /* We'll just try again later. */
 
@@ -1625,7 +1625,7 @@ static int tso_fragment(struct sock *sk, struct sk_buff *skb, unsigned int len,
 
         /* All of a TSO frame must be composed of paged data.  */
         if (skb->len != skb->data_len)
-                return tcp_fragment(sk, skb, len, mss_now);
+                return tcp_fragment(sk, skb, len, mss_now, gfp);
 
         buff = sk_stream_alloc_skb(sk, 0, gfp);
         if (unlikely(buff == NULL))
@@ -2122,7 +2122,8 @@ void tcp_send_loss_probe(struct sock *sk)
                 goto rearm_timer;
 
         if ((pcount > 1) && (skb->len > (pcount - 1) * mss)) {
-                if (unlikely(tcp_fragment(sk, skb, (pcount - 1) * mss, mss)))
+                if (unlikely(tcp_fragment(sk, skb, (pcount - 1) * mss, mss,
+                                          GFP_ATOMIC)))
                         goto rearm_timer;
                 skb = tcp_write_queue_tail(sk);
         }
@@ -2463,7 +2464,7 @@ int __tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb)
                 return -EAGAIN;
 
         if (skb->len > cur_mss) {
-                if (tcp_fragment(sk, skb, cur_mss, cur_mss))
+                if (tcp_fragment(sk, skb, cur_mss, cur_mss, GFP_ATOMIC))
                         return -ENOMEM; /* We'll try again later. */
         } else {
                 int oldpcount = tcp_skb_pcount(skb);
@@ -3244,7 +3245,7 @@ int tcp_write_wakeup(struct sock *sk)
                     skb->len > mss) {
                         seg_size = min(seg_size, mss);
                         TCP_SKB_CB(skb)->tcp_flags |= TCPHDR_PSH;
-                        if (tcp_fragment(sk, skb, seg_size, mss))
+                        if (tcp_fragment(sk, skb, seg_size, mss, GFP_ATOMIC))
                                 return -1;
                 } else if (!tcp_skb_pcount(skb))
                         tcp_set_skb_tso_segs(sk, skb, mss);