From: Florian Westphal <fw@strlen.de>
To: <netdev@vger.kernel.org>
Cc: Florian Westphal <fw@strlen.de>
Subject: [PATCH net-next 6/6] xfrm: state: don't use lock anymore unless acquire operation is needed
Date: Tue, 9 Aug 2016 12:16:09 +0200 [thread overview]
Message-ID: <1470737769-30438-7-git-send-email-fw@strlen.de> (raw)
In-Reply-To: <1470737769-30438-1-git-send-email-fw@strlen.de>
push the lock down, after earlier patches we can rely on rcu to
make sure state struct won't go away.
Signed-off-by: Florian Westphal <fw@strlen.de>
---
include/net/netns/xfrm.h | 6 +++---
net/xfrm/xfrm_state.c | 6 ++++--
2 files changed, 7 insertions(+), 5 deletions(-)
diff --git a/include/net/netns/xfrm.h b/include/net/netns/xfrm.h
index 24cd394..1ab51d1 100644
--- a/include/net/netns/xfrm.h
+++ b/include/net/netns/xfrm.h
@@ -38,9 +38,9 @@ struct netns_xfrm {
* mode. Also, it can be used by ah/esp icmp error handler to find
* offending SA.
*/
- struct hlist_head *state_bydst;
- struct hlist_head *state_bysrc;
- struct hlist_head *state_byspi;
+ struct hlist_head __rcu *state_bydst;
+ struct hlist_head __rcu *state_bysrc;
+ struct hlist_head __rcu *state_byspi;
unsigned int state_hmask;
unsigned int state_num;
struct work_struct state_hash_work;
diff --git a/net/xfrm/xfrm_state.c b/net/xfrm/xfrm_state.c
index 53e7867..1a15b65 100644
--- a/net/xfrm/xfrm_state.c
+++ b/net/xfrm/xfrm_state.c
@@ -799,7 +799,7 @@ xfrm_state_find(const xfrm_address_t *daddr, const xfrm_address_t *saddr,
sequence = read_seqcount_begin(&xfrm_state_hash_generation);
- spin_lock_bh(&net->xfrm.xfrm_state_lock);
+ rcu_read_lock();
h = xfrm_dst_hash(net, daddr, saddr, tmpl->reqid, encap_family);
hlist_for_each_entry_rcu(x, net->xfrm.state_bydst + h, bydst) {
if (x->props.family == encap_family &&
@@ -870,6 +870,7 @@ found:
}
if (km_query(x, tmpl, pol) == 0) {
+ spin_lock_bh(&net->xfrm.xfrm_state_lock);
x->km.state = XFRM_STATE_ACQ;
list_add(&x->km.all, &net->xfrm.state_all);
hlist_add_head_rcu(&x->bydst, net->xfrm.state_bydst + h);
@@ -883,6 +884,7 @@ found:
tasklet_hrtimer_start(&x->mtimer, ktime_set(net->xfrm.sysctl_acq_expires, 0), HRTIMER_MODE_REL);
net->xfrm.state_num++;
xfrm_hash_grow_check(net, x->bydst.next != NULL);
+ spin_unlock_bh(&net->xfrm.xfrm_state_lock);
} else {
x->km.state = XFRM_STATE_DEAD;
to_put = x;
@@ -899,7 +901,7 @@ out:
} else {
*err = acquire_in_progress ? -EAGAIN : error;
}
- spin_unlock_bh(&net->xfrm.xfrm_state_lock);
+ rcu_read_unlock();
if (to_put)
xfrm_state_put(to_put);
--
2.7.3
next prev parent reply other threads:[~2016-08-09 10:16 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-08-09 10:16 [PATCH net-next 0/6] xfrm: convert xfrm_state_find to rcu Florian Westphal
2016-08-09 10:16 ` [PATCH net-next 1/6] xfrm: state: use hlist_for_each_entry_rcu helper Florian Westphal
2016-08-09 10:16 ` [PATCH net-next 2/6] xfrm: state: use atomic_inc_not_zero to increment refcount Florian Westphal
2016-08-09 10:16 ` [PATCH net-next 3/6] xfrm: state: delay freeing until rcu grace period has elapsed Florian Westphal
2016-08-09 10:16 ` [PATCH net-next 4/6] xfrm: state: add sequence count to detect hash resizes Florian Westphal
2016-08-09 10:16 ` [PATCH net-next 5/6] xfrm: state: use rcu_deref and assign_pointer helpers Florian Westphal
2016-08-09 10:16 ` Florian Westphal [this message]
2016-08-11 11:13 ` [PATCH net-next 0/6] xfrm: convert xfrm_state_find to rcu Steffen Klassert
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