batman-adv uses a self-written reference implementation which is just based on atomic_t. This is less obvious when reading the code than kref and therefore increases the change that the reference counting will be missed.
Signed-off-by: Sven Eckelmann sven@narfation.org --- v6: - removed patches which are now applied in the branch next - rebased remaining patches on the patch "batman-adv: Avoid recursive call_rcu for batadv_nc_node" which was modified by Marek while he applied the patches (this unfortunately made some of the remaining patches "hard" to apply) v5: - add hack which allows to compile against stable kernel like 3.2.44 which also added the kref_get_unless_zero function v4: - fix function names in commit messages - fix double whitespace in batadv_tt_orig_list_entry_release kerneldoc - add extra patch for batadv_claim_free_ref kerneldoc fix - change the phrase "free it" in all *_free_ref/*_put functions to "release it" v3: - update copyright year v2: - split patchset into fixes and kref migration to make it easier when the decision is made where each patch will be applied
net/batman-adv/network-coding.c | 21 +++++++++++++-------- net/batman-adv/types.h | 2 +- 2 files changed, 14 insertions(+), 9 deletions(-)
diff --git a/net/batman-adv/network-coding.c b/net/batman-adv/network-coding.c index 0b30c15..7a1216e 100644 --- a/net/batman-adv/network-coding.c +++ b/net/batman-adv/network-coding.c @@ -32,6 +32,7 @@ #include <linux/jhash.h> #include <linux/jiffies.h> #include <linux/kernel.h> +#include <linux/kref.h> #include <linux/list.h> #include <linux/lockdep.h> #include <linux/netdevice.h> @@ -209,23 +210,26 @@ void batadv_nc_init_orig(struct batadv_orig_node *orig_node) /** * batadv_nc_node_release - release nc_node from lists and queue for free after * rcu grace period - * @nc_node: the nc node to free + * @ref: kref pointer of the nc_node */ -static void batadv_nc_node_release(struct batadv_nc_node *nc_node) +static void batadv_nc_node_release(struct kref *ref) { + struct batadv_nc_node *nc_node; + + nc_node = container_of(ref, struct batadv_nc_node, refcount); + batadv_orig_node_free_ref(nc_node->orig_node); kfree_rcu(nc_node, rcu); }
/** - * batadv_nc_node_free_ref - decrement the nc node refcounter and possibly + * batadv_nc_node_free_ref - decrement the nc_node refcounter and possibly * release it - * @nc_node: the nc node to free + * @nc_node: nc_node to be free'd */ static void batadv_nc_node_free_ref(struct batadv_nc_node *nc_node) { - if (atomic_dec_and_test(&nc_node->refcount)) - batadv_nc_node_release(nc_node); + kref_put(&nc_node->refcount, batadv_nc_node_release); }
/** @@ -797,7 +801,7 @@ static struct batadv_nc_node if (!batadv_compare_eth(nc_node->addr, orig_node->orig)) continue;
- if (!atomic_inc_not_zero(&nc_node->refcount)) + if (!kref_get_unless_zero(&nc_node->refcount)) continue;
/* Found a match */ @@ -848,7 +852,8 @@ static struct batadv_nc_node INIT_LIST_HEAD(&nc_node->list); ether_addr_copy(nc_node->addr, orig_node->orig); nc_node->orig_node = orig_neigh_node; - atomic_set(&nc_node->refcount, 2); + kref_init(&nc_node->refcount); + kref_get(&nc_node->refcount);
/* Select ingoing or outgoing coding node */ if (in_coding) { diff --git a/net/batman-adv/types.h b/net/batman-adv/types.h index 34c13b6..05421af 100644 --- a/net/batman-adv/types.h +++ b/net/batman-adv/types.h @@ -1067,7 +1067,7 @@ struct batadv_tt_roam_node { struct batadv_nc_node { struct list_head list; u8 addr[ETH_ALEN]; - atomic_t refcount; + struct kref refcount; struct rcu_head rcu; struct batadv_orig_node *orig_node; unsigned long last_seen;