tcp/dccp: add SLAB_DESTROY_BY_RCU flag for request sockets
Before letting request sockets being put in TCP/DCCP regular
ehash table, we need to add either :
- SLAB_DESTROY_BY_RCU flag to their kmem_cache
- add RCU grace period before freeing them.
Since we carefully respected the SLAB_DESTROY_BY_RCU protocol
like ESTABLISH and TIMEWAIT sockets, use it here.
req_prot_init() being only used by TCP and DCCP, I did not add
a new slab_flags into their rsk_prot, but reuse prot->slab_flags
Since all reqsk_alloc() users are correctly dealing with a failure,
add the __GFP_NOWARN flag to avoid traces under pressure.
Fixes: 079096f103fa ("tcp/dccp: install syn_recv requests into ehash table")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/request_sock.h b/include/net/request_sock.h
index bae6936..dd423d8 100644
--- a/include/net/request_sock.h
+++ b/include/net/request_sock.h
@@ -82,7 +82,9 @@
static inline struct request_sock *
reqsk_alloc(const struct request_sock_ops *ops, struct sock *sk_listener)
{
- struct request_sock *req = kmem_cache_alloc(ops->slab, GFP_ATOMIC);
+ struct request_sock *req;
+
+ req = kmem_cache_alloc(ops->slab, GFP_ATOMIC | __GFP_NOWARN);
if (req) {
req->rsk_ops = ops;
