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author | Martin KaFai Lau | 2015-09-15 23:30:08 +0200 |
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committer | David S. Miller | 2015-09-15 23:53:05 +0200 |
commit | 8e3d5be7368107f0c27a1f8126d79b01a47e9567 (patch) | |
tree | 9930ab62052124ba2e56db04cdbab518a533f4bc /net/rxrpc/ar-transport.c | |
parent | ipv6: Fix dst_entry refcnt bugs in ip6_tunnel (diff) | |
download | kernel-qcow2-linux-8e3d5be7368107f0c27a1f8126d79b01a47e9567.tar.gz kernel-qcow2-linux-8e3d5be7368107f0c27a1f8126d79b01a47e9567.tar.xz kernel-qcow2-linux-8e3d5be7368107f0c27a1f8126d79b01a47e9567.zip |
ipv6: Avoid double dst_free
It is a prep work to get dst freeing from fib tree undergo
a rcu grace period.
The following is a common paradigm:
if (ip6_del_rt(rt))
dst_free(rt)
which means, if rt cannot be deleted from the fib tree, dst_free(rt) now.
1. We don't know the ip6_del_rt(rt) failure is because it
was not managed by fib tree (e.g. DST_NOCACHE) or it had already been
removed from the fib tree.
2. If rt had been managed by the fib tree, ip6_del_rt(rt) failure means
dst_free(rt) has been called already. A second
dst_free(rt) is not always obviously safe. The rt may have
been destroyed already.
3. If rt is a DST_NOCACHE, dst_free(rt) should not be called.
4. It is a stopper to make dst freeing from fib tree undergo a
rcu grace period.
This patch is to use a DST_NOCACHE flag to indicate a rt is
not managed by the fib tree.
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/rxrpc/ar-transport.c')
0 files changed, 0 insertions, 0 deletions