From: Sven Eckelmann <sven@narfation.org>
To: b.a.t.m.a.n@lists.open-mesh.org
Cc: "Linus Lüssing" <linus.luessing@ascom.ch>
Subject: Re: [B.A.T.M.A.N.] [PATCH 1/3] batman-adv: Correct rcu refcounting for gw_node
Date: Thu, 3 Feb 2011 18:56:37 +0100 [thread overview]
Message-ID: <201102031856.39736.sven@narfation.org> (raw)
In-Reply-To: <1296744201-11542-1-git-send-email-linus.luessing@ascom.ch>
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> For another the rcu protected macros rcu_dereference() and
> rcu_assign_pointer() for the bat_priv->curr_gw and curr_gw->orig_node
> need to be used.
What? Since when is curr_gw::orig_node rcu protected?
> - return curr_gateway_tmp->orig_node;
> + orig_node = rcu_dereference(curr_gateway_tmp->orig_node);
> + if (orig_node) {
> + rcu_read_unlock();
> + return NULL;
> + }
> +
> + rcu_read_unlock();
> + return orig_node;
> }
And you cannot return the (it is not, but when it would be) rcu protected
element without increasing the refcounter.
> + orig_node = rcu_dereference(gw_node->orig_node);
> + if (!orig_node->router)
> continue;
Same here
> - if (bat_priv->curr_gw != curr_gw_tmp) {
> - if ((bat_priv->curr_gw) && (!curr_gw_tmp))
> + if (curr_gw != curr_gw_tmp) {
> + orig_node = rcu_dereference(curr_gw_tmp->orig_node);
> + if ((curr_gw) && (!curr_gw_tmp))
And here
> - if (bat_priv->curr_gw != curr_gw_tmp) {
> - if ((bat_priv->curr_gw) && (!curr_gw_tmp))
> + if (curr_gw != curr_gw_tmp) {
> + orig_node = rcu_dereference(curr_gw_tmp->orig_node);
> + if ((curr_gw) && (!curr_gw_tmp))
Here again
> - if (bat_priv->curr_gw != curr_gw_tmp) {
> - if ((bat_priv->curr_gw) && (!curr_gw_tmp))
> + if (curr_gw != curr_gw_tmp) {
> + orig_node = rcu_dereference(curr_gw_tmp->orig_node);
> + if ((curr_gw) && (!curr_gw_tmp))
Here....
> - gw_bandwidth_to_kbit(gw_node->orig_node->gw_flags, &down, &up);
> + rcu_read_lock();
> + curr_gw = rcu_dereference(bat_priv->curr_gw);
> + orig_node = rcu_dereference(gw_node->orig_node);
> + gw_bandwidth_to_kbit(orig_node->gw_flags, &down, &up);
....
> diff --git a/batman-adv/unicast.c b/batman-adv/unicast.c
> index 6a9ab61..8816102 100644
> --- a/batman-adv/unicast.c
> +++ b/batman-adv/unicast.c
> @@ -298,7 +298,6 @@ int unicast_send_skb(struct sk_buff *skb, struct
> bat_priv *bat_priv) if (!orig_node)
> goto trans_search;
>
> - kref_get(&orig_node->refcount);
> goto find_router;
> } else {
> rcu_read_lock();
Why? Maybe this should be part of the patch 3/3?
And please to merge the refcounting stuff with the rcu pointer in one patch...
and maybe it is better to merge patch 2/3 with the rcu pointer patch.
Best regards,
Sven
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next prev parent reply other threads:[~2011-02-03 17:56 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-01-30 1:52 [B.A.T.M.A.N.] Reordered rcu refcounting Sven Eckelmann
2011-01-30 1:52 ` [B.A.T.M.A.N.] [PATCH 1/4] batman-adv: Correct rcu refcounting for gw_node Sven Eckelmann
2011-02-02 17:37 ` [B.A.T.M.A.N.] [PATCH] " Linus Lüssing
2011-02-02 19:49 ` Marek Lindner
2011-02-02 20:43 ` Linus Lüssing
2011-02-02 21:42 ` Sven Eckelmann
2011-02-03 0:19 ` Marek Lindner
2011-02-03 9:55 ` Linus Lüssing
2011-02-03 10:01 ` Sven Eckelmann
2011-02-03 14:43 ` [B.A.T.M.A.N.] [PATCH 1/3] " Linus Lüssing
2011-02-03 17:56 ` Sven Eckelmann [this message]
2011-02-03 14:43 ` [B.A.T.M.A.N.] [PATCH 2/3] batman-adv: add __rcu annotations " Linus Lüssing
2011-02-03 14:43 ` [B.A.T.M.A.N.] [PATCH 3/3] batman-adv: Increase orig_node refcount before releasing rcu read lock Linus Lüssing
2011-01-30 1:52 ` [B.A.T.M.A.N.] [PATCH 2/4] batman-adv: Correct rcu refcounting for softif_neigh Sven Eckelmann
2011-01-30 1:52 ` [B.A.T.M.A.N.] [PATCH 3/4] batman-adv: Correct rcu refcounting for batman_if Sven Eckelmann
2011-01-30 1:52 ` [B.A.T.M.A.N.] [PATCH 4/4] batman-adv: Correct rcu refcounting for neigh_node Sven Eckelmann
2011-01-30 15:20 ` [B.A.T.M.A.N.] [PATCHv2 " Sven Eckelmann
2011-02-03 17:02 ` [B.A.T.M.A.N.] Reordered rcu refcounting Marek Lindner
2011-02-03 17:03 ` [B.A.T.M.A.N.] [PATCH 1/4] batman-adv: Correct rcu refcounting for gw_node Marek Lindner
2011-02-03 17:03 ` [B.A.T.M.A.N.] [PATCH 2/4] batman-adv: Correct rcu refcounting for softif_neigh Marek Lindner
2011-02-03 17:03 ` [B.A.T.M.A.N.] [PATCH 3/4] batman-adv: Correct rcu refcounting for batman_if Marek Lindner
2011-02-03 17:03 ` [B.A.T.M.A.N.] [PATCH 4/4] batman-adv: Correct rcu refcounting for neigh_node Marek Lindner
2011-02-04 12:59 ` [B.A.T.M.A.N.] [PATCHv2 " Marek Lindner
2011-02-04 15:21 ` [B.A.T.M.A.N.] Reordered rcu refcounting, v3 Linus Lüssing
2011-02-04 15:21 ` [B.A.T.M.A.N.] [PATCH 1/7] batman-adv: Correct rcu refcounting for gw_node Linus Lüssing
2011-02-10 11:01 ` Linus Lüssing
2011-02-04 15:21 ` [B.A.T.M.A.N.] [PATCH 2/7] batman-adv: Correct rcu refcounting for softif_neigh Linus Lüssing
2011-02-10 12:45 ` Linus Lüssing
2011-02-10 13:57 ` Marek Lindner
2011-02-12 21:23 ` Linus Lüssing
2011-02-04 15:21 ` [B.A.T.M.A.N.] [PATCH 3/7] batman-adv: Correct rcu refcounting for batman_if Linus Lüssing
2011-02-04 15:21 ` [B.A.T.M.A.N.] [PATCH 4/7] batman-adv: Correct rcu refcounting for neigh_node Linus Lüssing
2011-02-04 15:21 ` [B.A.T.M.A.N.] [PATCH 5/7] batman-adv: Make bat_priv->curr_gw an rcu protected pointer Linus Lüssing
2011-02-08 13:18 ` Marek Lindner
2011-02-10 10:42 ` Linus Lüssing
2011-02-10 14:25 ` Marek Lindner
2011-02-12 21:21 ` Linus Lüssing
2011-02-12 21:21 ` [B.A.T.M.A.N.] [PATCHv2 " Linus Lüssing
2011-02-13 21:09 ` Marek Lindner
2011-02-04 15:21 ` [B.A.T.M.A.N.] [PATCH 6/7] batman-adv: add __rcu annotations for gw_node Linus Lüssing
2011-02-13 21:10 ` Marek Lindner
2011-02-04 15:21 ` [B.A.T.M.A.N.] [PATCH 7/7] batman-adv: Increase orig_node refcount before releasing rcu read lock Linus Lüssing
2011-02-04 16:33 ` [B.A.T.M.A.N.] [PATCHv2 " Linus Lüssing
2011-02-13 21:11 ` [B.A.T.M.A.N.] [PATCH " Marek Lindner
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