diff options
| author | Jesper Dangaard Brouer <brouer@redhat.com> | 2013-03-27 05:55:25 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2013-03-27 12:48:33 -0400 |
| commit | 68399ac37e571c2d695ea3b08aa82235874b5158 (patch) | |
| tree | 03e6d64768df3178e8bb4ef897e5d8c6ca1cb24c /net | |
| parent | 167bfa71844a7a7415da0fa8c75e672f3bd438c8 (diff) | |
net: frag, avoid several CPUs grabbing same frag queue during LRU evictor loop
The LRU list is protected by its own lock, since commit 3ef0eb0db4
(net: frag, move LRU list maintenance outside of rwlock), and
no-longer by a read_lock.
This makes it possible, to remove the inet_frag_queue, which is about
to be "evicted", from the LRU list head. This avoids the problem, of
several CPUs grabbing the same frag queue.
Note, cannot remove the inet_frag_lru_del() call in fq_unlink()
called by inet_frag_kill(), because inet_frag_kill() is also used in
other situations. Thus, we use list_del_init() to allow this
double list_del to work.
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
| -rw-r--r-- | net/ipv4/inet_fragment.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/net/ipv4/inet_fragment.c b/net/ipv4/inet_fragment.c index 2bff045bec6..8ba548a8efc 100644 --- a/net/ipv4/inet_fragment.c +++ b/net/ipv4/inet_fragment.c @@ -204,6 +204,9 @@ int inet_frag_evictor(struct netns_frags *nf, struct inet_frags *f, bool force) q = list_first_entry(&nf->lru_list, struct inet_frag_queue, lru_list); atomic_inc(&q->refcnt); + /* Remove q from list to avoid several CPUs grabbing it */ + list_del_init(&q->lru_list); + spin_unlock(&nf->lru_lock); spin_lock(&q->lock); |