[PATCH net 1/2] Revert "net: defer call to cgroup_sk_alloc()"

[Eric Dumazet]

This reverts commit fbb1fb4ad415cb31ce944f65a5ca700aaf73a227.

This was not the proper fix, lets cleanly revert it, so that
following patch can be carried to stable versions.

sock_cgroup_ptr() callers do not expect a NULL return value.

Signed-off-by: Eric Dumazet <eduma...@google.com>
Cc: Johannes Weiner <han...@cmpxchg.org>
Cc: Tejun Heo <t...@kernel.org>
---
 kernel/cgroup/cgroup.c          | 11 +++++++++++
 net/core/sock.c                 |  3 ++-
 net/ipv4/inet_connection_sock.c |  5 -----
 3 files changed, 13 insertions(+), 6 deletions(-)

diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c
index 
3380a3e49af501e457991b2823020494cf32af80..44857278eb8aa6a2bbf27b7eb12137ef42628170
 100644
--- a/kernel/cgroup/cgroup.c
+++ b/kernel/cgroup/cgroup.c
@@ -5709,6 +5709,17 @@ void cgroup_sk_alloc(struct sock_cgroup_data *skcd)
        if (cgroup_sk_alloc_disabled)
                return;
 
+       /* Socket clone path */
+       if (skcd->val) {
+               /*
+                * We might be cloning a socket which is left in an empty
+                * cgroup and the cgroup might have already been rmdir'd.
+                * Don't use cgroup_get_live().
+                */
+               cgroup_get(sock_cgroup_ptr(skcd));
+               return;
+       }
+
        rcu_read_lock();
 
        while (true) {
diff --git a/net/core/sock.c b/net/core/sock.c
index 
4499e31538132ed59a16d92e6f6b923e776df84e..70c6ccbdf49f2f8a5a0f7c41c7849ea01459be50
 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -1680,7 +1680,6 @@ struct sock *sk_clone_lock(const struct sock *sk, const 
gfp_t priority)
 
                /* sk->sk_memcg will be populated at accept() time */
                newsk->sk_memcg = NULL;
-               memset(&newsk->sk_cgrp_data, 0, sizeof(newsk->sk_cgrp_data));
 
                atomic_set(&newsk->sk_drops, 0);
                newsk->sk_send_head     = NULL;
@@ -1719,6 +1718,8 @@ struct sock *sk_clone_lock(const struct sock *sk, const 
gfp_t priority)
                newsk->sk_incoming_cpu = raw_smp_processor_id();
                atomic64_set(&newsk->sk_cookie, 0);
 
+               cgroup_sk_alloc(&newsk->sk_cgrp_data);
+
                /*
                 * Before updating sk_refcnt, we must commit prior changes to 
memory
                 * (Documentation/RCU/rculist_nulls.txt for details)
diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c
index 
d32c74507314cc4b91d040de8e877e4bd8204106..67aec7a106860b26c929fea1624d652c87972f04
 100644
--- a/net/ipv4/inet_connection_sock.c
+++ b/net/ipv4/inet_connection_sock.c
@@ -26,8 +26,6 @@
 #include <net/tcp.h>
 #include <net/sock_reuseport.h>
 #include <net/addrconf.h>
-#include <net/cls_cgroup.h>
-#include <net/netprio_cgroup.h>
 
 #ifdef INET_CSK_DEBUG
 const char inet_csk_timer_bug_msg[] = "inet_csk BUG: unknown timer value\n";
@@ -478,9 +476,6 @@ struct sock *inet_csk_accept(struct sock *sk, int flags, 
int *err, bool kern)
                spin_unlock_bh(&queue->fastopenq.lock);
        }
        mem_cgroup_sk_alloc(newsk);
-       cgroup_sk_alloc(&newsk->sk_cgrp_data);
-       sock_update_classid(&newsk->sk_cgrp_data);
-       sock_update_netprioidx(&newsk->sk_cgrp_data);
 out:
        release_sock(sk);
        if (req)
-- 
2.15.0.rc0.271.g36b669edcc-goog