From e96f78ab2703f3b0d512f6b469bc685d2ef20475 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Sat, 3 Oct 2015 06:27:28 -0700 Subject: [PATCH] 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 Signed-off-by: David S. Miller --- include/net/request_sock.h | 4 +++- net/core/sock.c | 2 +- 2 files changed, 4 insertions(+), 2 deletions(-) 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 sock *req_to_sk(struct request_sock *req) 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; diff --git a/net/core/sock.c b/net/core/sock.c index 3307c02..7dd1263 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -2758,7 +2758,7 @@ static int req_prot_init(const struct proto *prot) rsk_prot->slab = kmem_cache_create(rsk_prot->slab_name, rsk_prot->obj_size, 0, - 0, NULL); + prot->slab_flags, NULL); if (!rsk_prot->slab) { pr_crit("%s: Can't create request sock SLAB cache!\n", -- 2.7.4