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xfrm: state: use rcu_deref and assign_pointer helpers

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Before xfrm_state_find() can use rcu_read_lock instead of xfrm_state_lock
we need to switch users of the hash table to assign/obtain the pointers
with the appropriate rcu helpers.

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 12:16:08 +02:00 committed by Steffen Klassert
parent b65e3d7be0
commit c8406998b8
1 changed files with 10 additions and 8 deletions
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18
net/xfrm/xfrm_state.c
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@ -28,6 +28,9 @@
#include "xfrm_hash.h"
#define xfrm_state_deref_prot(table, net) \
rcu_dereference_protected((table), lockdep_is_held(&(net)->xfrm.xfrm_state_lock))
/* Each xfrm_state may be linked to two tables:
1. Hash table by (spi,daddr,ah/esp) to find SA by SPI. (input,ctl)
@ -131,18 +134,17 @@ static void xfrm_hash_resize(struct work_struct *work)
write_seqcount_begin(&xfrm_state_hash_generation);
nhashmask = (nsize / sizeof(struct hlist_head)) - 1U;
odst = xfrm_state_deref_prot(net->xfrm.state_bydst, net);
for (i = net->xfrm.state_hmask; i >= 0; i--)
xfrm_hash_transfer(net->xfrm.state_bydst+i, ndst, nsrc, nspi,
nhashmask);
xfrm_hash_transfer(odst + i, ndst, nsrc, nspi, nhashmask);
odst = net->xfrm.state_bydst;
osrc = net->xfrm.state_bysrc;
ospi = net->xfrm.state_byspi;
osrc = xfrm_state_deref_prot(net->xfrm.state_bysrc, net);
ospi = xfrm_state_deref_prot(net->xfrm.state_byspi, net);
ohashmask = net->xfrm.state_hmask;
net->xfrm.state_bydst = ndst;
net->xfrm.state_bysrc = nsrc;
net->xfrm.state_byspi = nspi;
rcu_assign_pointer(net->xfrm.state_bydst, ndst);
rcu_assign_pointer(net->xfrm.state_bysrc, nsrc);
rcu_assign_pointer(net->xfrm.state_byspi, nspi);
net->xfrm.state_hmask = nhashmask;
write_seqcount_end(&xfrm_state_hash_generation);