Eric Lee / smarc-fsl-linux-kernel

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Commit 38e6bc185d9544dfad1774b3f8902a0b061aea25

Authored by Amerigo Wang
Committed by David S. Miller
1 parent 47be03a28c

netpoll: make __netpoll_cleanup non-block 

Like the previous patch, slave_disable_netpoll() and __netpoll_cleanup()
may be called with read_lock() held too, so we should make them
non-block, by moving the cleanup and kfree() to call_rcu_bh() callbacks.

Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Cong Wang <amwang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Showing 5 changed files with 38 additions and 23 deletions Side-by-side Diff

drivers/net/bonding/bond_main.c
Diff comments   View file @ 38e6bc1
... ... @@ -1257,9 +1257,7 @@
1257 1257 return;
1258 1258  
1259 1259 slave->np = NULL;
1260   - synchronize_rcu_bh();
1261   - __netpoll_cleanup(np);
1262   - kfree(np);
  1260 + __netpoll_free_rcu(np);
1263 1261 }
1264 1262 static inline bool slave_dev_support_netpoll(struct net_device *slave_dev)
1265 1263 {
include/linux/netpoll.h
Diff comments   View file @ 38e6bc1
... ... @@ -23,6 +23,7 @@
23 23 u8 remote_mac[ETH_ALEN];
24 24  
25 25 struct list_head rx; /* rx_np list element */
  26 + struct rcu_head rcu;
26 27 };
27 28  
28 29 struct netpoll_info {
... ... @@ -38,6 +39,7 @@
38 39 struct delayed_work tx_work;
39 40  
40 41 struct netpoll *netpoll;
  42 + struct rcu_head rcu;
41 43 };
42 44  
43 45 void netpoll_send_udp(struct netpoll *np, const char *msg, int len);
... ... @@ -48,6 +50,7 @@
48 50 int netpoll_trap(void);
49 51 void netpoll_set_trap(int trap);
50 52 void __netpoll_cleanup(struct netpoll *np);
  53 +void __netpoll_free_rcu(struct netpoll *np);
51 54 void netpoll_cleanup(struct netpoll *np);
52 55 int __netpoll_rx(struct sk_buff *skb);
53 56 void netpoll_send_skb_on_dev(struct netpoll *np, struct sk_buff *skb,
net/8021q/vlan_dev.c
Diff comments   View file @ 38e6bc1
... ... @@ -704,11 +704,7 @@
704 704  
705 705 info->netpoll = NULL;
706 706  
707   - /* Wait for transmitting packets to finish before freeing. */
708   - synchronize_rcu_bh();
709   -
710   - __netpoll_cleanup(netpoll);
711   - kfree(netpoll);
  707 + __netpoll_free_rcu(netpoll);
712 708 }
713 709 #endif /* CONFIG_NET_POLL_CONTROLLER */
714 710  
net/bridge/br_device.c
Diff comments   View file @ 38e6bc1
... ... @@ -267,11 +267,7 @@
267 267  
268 268 p->np = NULL;
269 269  
270   - /* Wait for transmitting packets to finish before freeing. */
271   - synchronize_rcu_bh();
272   -
273   - __netpoll_cleanup(np);
274   - kfree(np);
  270 + __netpoll_free_rcu(np);
275 271 }
276 272  
277 273 #endif
... ... @@ -878,6 +878,24 @@
878 878 }
879 879 core_initcall(netpoll_init);
880 880  
  881 +static void rcu_cleanup_netpoll_info(struct rcu_head *rcu_head)
  882 +{
  883 + struct netpoll_info *npinfo =
  884 + container_of(rcu_head, struct netpoll_info, rcu);
  885 +
  886 + skb_queue_purge(&npinfo->arp_tx);
  887 + skb_queue_purge(&npinfo->txq);
  888 +
  889 + /* we can't call cancel_delayed_work_sync here, as we are in softirq */
  890 + cancel_delayed_work(&npinfo->tx_work);
  891 +
  892 + /* clean after last, unfinished work */
  893 + __skb_queue_purge(&npinfo->txq);
  894 + /* now cancel it again */
  895 + cancel_delayed_work(&npinfo->tx_work);
  896 + kfree(npinfo);
  897 +}
  898 +
881 899 void __netpoll_cleanup(struct netpoll *np)
882 900 {
883 901 struct netpoll_info *npinfo;
884 902  
885 903  
886 904  
887 905  
... ... @@ -903,20 +921,24 @@
903 921 ops->ndo_netpoll_cleanup(np->dev);
904 922  
905 923 RCU_INIT_POINTER(np->dev->npinfo, NULL);
  924 + call_rcu_bh(&npinfo->rcu, rcu_cleanup_netpoll_info);
  925 + }
  926 +}
  927 +EXPORT_SYMBOL_GPL(__netpoll_cleanup);
906 928  
907   - /* avoid racing with NAPI reading npinfo */
908   - synchronize_rcu_bh();
  929 +static void rcu_cleanup_netpoll(struct rcu_head *rcu_head)
  930 +{
  931 + struct netpoll *np = container_of(rcu_head, struct netpoll, rcu);
909 932  
910   - skb_queue_purge(&npinfo->arp_tx);
911   - skb_queue_purge(&npinfo->txq);
912   - cancel_delayed_work_sync(&npinfo->tx_work);
  933 + __netpoll_cleanup(np);
  934 + kfree(np);
  935 +}
913 936  
914   - /* clean after last, unfinished work */
915   - __skb_queue_purge(&npinfo->txq);
916   - kfree(npinfo);
917   - }
  937 +void __netpoll_free_rcu(struct netpoll *np)
  938 +{
  939 + call_rcu_bh(&np->rcu, rcu_cleanup_netpoll);
918 940 }
919   -EXPORT_SYMBOL_GPL(__netpoll_cleanup);
  941 +EXPORT_SYMBOL_GPL(__netpoll_free_rcu);
920 942  
921 943 void netpoll_cleanup(struct netpoll *np)
922 944 {