leandrof/linux
1
0
Fork 0
forked from Minki/linux
Code Issues Pull Requests Packages Projects Releases Wiki Activity

xfrm: state: don't use lock anymore unless acquire operation is needed

Browse Source 
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>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
This commit is contained in:
Florian Westphal 2016-08-09 12:16:09 +02:00 committed by Steffen Klassert
parent c8406998b8
commit d737a58055
2 changed files with 7 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
include/net/netns/xfrm.h
View File

@ -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;

6
net/xfrm/xfrm_state.c
View File

@ -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);