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| author | Kirill Tkhai <ktkhai@virtuozzo.com> | 2018-03-22 12:45:02 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2018-03-22 15:12:55 -0400 |
| commit | 76d3e153d0d16032ab68e3b698c4df05acef48c5 (patch) | |
| tree | 99dc22608c62b6beb7e22913c1aabe0b6f615d24 /net/ipv4 | |
| parent | f2d254fac13cc7c86871ea607c4ab1afa7f13e2e (diff) | |
| download | linux-stable-76d3e153d0d16032ab68e3b698c4df05acef48c5.tar.gz linux-stable-76d3e153d0d16032ab68e3b698c4df05acef48c5.tar.bz2 linux-stable-76d3e153d0d16032ab68e3b698c4df05acef48c5.zip | |
net: Revert "ipv4: get rid of ip_ra_lock"
This reverts commit ba3f571d5dde. The commit was made
after 1215e51edad1 "ipv4: fix a deadlock in ip_ra_control",
and killed ip_ra_lock, which became useless after rtnl_lock()
made used to destroy every raw ipv4 socket. This scales
very bad, and next patch in series reverts 1215e51edad1.
ip_ra_lock will be used again.
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4')
| -rw-r--r-- | net/ipv4/ip_sockglue.c | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c index 74c962b9b09c..be7c3b71914d 100644 --- a/net/ipv4/ip_sockglue.c +++ b/net/ipv4/ip_sockglue.c @@ -334,6 +334,7 @@ int ip_cmsg_send(struct sock *sk, struct msghdr *msg, struct ipcm_cookie *ipc, sent to multicast group to reach destination designated router. */ struct ip_ra_chain __rcu *ip_ra_chain; +static DEFINE_SPINLOCK(ip_ra_lock); static void ip_ra_destroy_rcu(struct rcu_head *head) @@ -355,17 +356,21 @@ int ip_ra_control(struct sock *sk, unsigned char on, new_ra = on ? kmalloc(sizeof(*new_ra), GFP_KERNEL) : NULL; + spin_lock_bh(&ip_ra_lock); for (rap = &ip_ra_chain; - (ra = rtnl_dereference(*rap)) != NULL; + (ra = rcu_dereference_protected(*rap, + lockdep_is_held(&ip_ra_lock))) != NULL; rap = &ra->next) { if (ra->sk == sk) { if (on) { + spin_unlock_bh(&ip_ra_lock); kfree(new_ra); return -EADDRINUSE; } /* dont let ip_call_ra_chain() use sk again */ ra->sk = NULL; RCU_INIT_POINTER(*rap, ra->next); + spin_unlock_bh(&ip_ra_lock); if (ra->destructor) ra->destructor(sk); @@ -379,14 +384,17 @@ int ip_ra_control(struct sock *sk, unsigned char on, return 0; } } - if (!new_ra) + if (!new_ra) { + spin_unlock_bh(&ip_ra_lock); return -ENOBUFS; + } new_ra->sk = sk; new_ra->destructor = destructor; RCU_INIT_POINTER(new_ra->next, ra); rcu_assign_pointer(*rap, new_ra); sock_hold(sk); + spin_unlock_bh(&ip_ra_lock); return 0; } |