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/bat_iv_ogm.c | 4 ++-- net/batman-adv/hard-interface.c | 20 +++++++++++++------- net/batman-adv/hard-interface.h | 16 +++++++--------- net/batman-adv/originator.c | 8 ++++---- net/batman-adv/types.h | 2 +- 5 files changed, 27 insertions(+), 23 deletions(-)
diff --git a/net/batman-adv/bat_iv_ogm.c b/net/batman-adv/bat_iv_ogm.c index affcbb5..bf0e7d6 100644 --- a/net/batman-adv/bat_iv_ogm.c +++ b/net/batman-adv/bat_iv_ogm.c @@ -644,10 +644,10 @@ static void batadv_iv_ogm_aggregate_new(const unsigned char *packet_buff, unsigned char *skb_buff; unsigned int skb_size;
- if (!atomic_inc_not_zero(&if_incoming->refcount)) + if (!kref_get_unless_zero(&if_incoming->refcount)) return;
- if (!atomic_inc_not_zero(&if_outgoing->refcount)) + if (!kref_get_unless_zero(&if_outgoing->refcount)) goto out_free_incoming;
/* own packet should always be scheduled */ diff --git a/net/batman-adv/hard-interface.c b/net/batman-adv/hard-interface.c index b17e272..fb2d9c0 100644 --- a/net/batman-adv/hard-interface.c +++ b/net/batman-adv/hard-interface.c @@ -18,6 +18,7 @@ #include "hard-interface.h" #include "main.h"
+#include <linux/atomic.h> #include <linux/bug.h> #include <linux/byteorder/generic.h> #include <linux/errno.h> @@ -26,6 +27,7 @@ #include <linux/if_ether.h> #include <linux/if.h> #include <linux/kernel.h> +#include <linux/kref.h> #include <linux/list.h> #include <linux/netdevice.h> #include <linux/printk.h> @@ -50,10 +52,13 @@ /** * batadv_hardif_release - release hard interface from lists and queue for * free after rcu grace period - * @hard_iface: the hard interface to free + * @ref: kref pointer of the hard interface */ -void batadv_hardif_release(struct batadv_hard_iface *hard_iface) +void batadv_hardif_release(struct kref *ref) { + struct batadv_hard_iface *hard_iface; + + hard_iface = container_of(ref, struct batadv_hard_iface, refcount); dev_put(hard_iface->net_dev);
kfree_rcu(hard_iface, rcu); @@ -67,7 +72,7 @@ batadv_hardif_get_by_netdev(const struct net_device *net_dev) rcu_read_lock(); list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) { if (hard_iface->net_dev == net_dev && - atomic_inc_not_zero(&hard_iface->refcount)) + kref_get_unless_zero(&hard_iface->refcount)) goto out; }
@@ -172,7 +177,7 @@ batadv_hardif_get_active(const struct net_device *soft_iface) continue;
if (hard_iface->if_status == BATADV_IF_ACTIVE && - atomic_inc_not_zero(&hard_iface->refcount)) + kref_get_unless_zero(&hard_iface->refcount)) goto out; }
@@ -206,7 +211,7 @@ static void batadv_primary_if_select(struct batadv_priv *bat_priv,
ASSERT_RTNL();
- if (new_hard_iface && !atomic_inc_not_zero(&new_hard_iface->refcount)) + if (new_hard_iface && !kref_get_unless_zero(&new_hard_iface->refcount)) new_hard_iface = NULL;
curr_hard_iface = rcu_dereference_protected(bat_priv->primary_if, 1); @@ -434,7 +439,7 @@ int batadv_hardif_enable_interface(struct batadv_hard_iface *hard_iface, if (hard_iface->if_status != BATADV_IF_NOT_IN_USE) goto out;
- if (!atomic_inc_not_zero(&hard_iface->refcount)) + if (!kref_get_unless_zero(&hard_iface->refcount)) goto out;
soft_iface = dev_get_by_name(&init_net, iface_name); @@ -655,7 +660,8 @@ batadv_hardif_add_interface(struct net_device *net_dev) hard_iface->num_bcasts = BATADV_NUM_BCASTS_WIRELESS;
/* extra reference for return */ - atomic_set(&hard_iface->refcount, 2); + kref_init(&hard_iface->refcount); + kref_get(&hard_iface->refcount);
batadv_check_known_mac_addr(hard_iface->net_dev); list_add_tail_rcu(&hard_iface->list, &batadv_hardif_list); diff --git a/net/batman-adv/hard-interface.h b/net/batman-adv/hard-interface.h index 9eb08ad..5cecc6b 100644 --- a/net/batman-adv/hard-interface.h +++ b/net/batman-adv/hard-interface.h @@ -20,8 +20,8 @@
#include "main.h"
-#include <linux/atomic.h> #include <linux/compiler.h> +#include <linux/kref.h> #include <linux/notifier.h> #include <linux/rcupdate.h> #include <linux/stddef.h> @@ -61,18 +61,16 @@ void batadv_hardif_disable_interface(struct batadv_hard_iface *hard_iface, void batadv_hardif_remove_interfaces(void); int batadv_hardif_min_mtu(struct net_device *soft_iface); void batadv_update_min_mtu(struct net_device *soft_iface); -void batadv_hardif_release(struct batadv_hard_iface *hard_iface); +void batadv_hardif_release(struct kref *ref);
/** - * batadv_hardif_free_ref - decrement the hard interface refcounter and - * possibly release it + * batadv_hardif_free_ref - decrement the hard interface refcounter and possibly + * release it * @hard_iface: the hard interface to free */ -static inline void -batadv_hardif_free_ref(struct batadv_hard_iface *hard_iface) +static inline void batadv_hardif_free_ref(struct batadv_hard_iface *hard_iface) { - if (atomic_dec_and_test(&hard_iface->refcount)) - batadv_hardif_release(hard_iface); + kref_put(&hard_iface->refcount, batadv_hardif_release); }
static inline struct batadv_hard_iface * @@ -85,7 +83,7 @@ batadv_primary_if_get_selected(struct batadv_priv *bat_priv) if (!hard_iface) goto out;
- if (!atomic_inc_not_zero(&hard_iface->refcount)) + if (!kref_get_unless_zero(&hard_iface->refcount)) hard_iface = NULL;
out: diff --git a/net/batman-adv/originator.c b/net/batman-adv/originator.c index 9e3dbd8..bf27007 100644 --- a/net/batman-adv/originator.c +++ b/net/batman-adv/originator.c @@ -367,7 +367,7 @@ batadv_orig_ifinfo_new(struct batadv_orig_node *orig_node, goto out;
if (if_outgoing != BATADV_IF_DEFAULT && - !atomic_inc_not_zero(&if_outgoing->refcount)) { + !kref_get_unless_zero(&if_outgoing->refcount)) { kfree(orig_ifinfo); orig_ifinfo = NULL; goto out; @@ -447,7 +447,7 @@ batadv_neigh_ifinfo_new(struct batadv_neigh_node *neigh, if (!neigh_ifinfo) goto out;
- if (if_outgoing && !atomic_inc_not_zero(&if_outgoing->refcount)) { + if (if_outgoing && !kref_get_unless_zero(&if_outgoing->refcount)) { kfree(neigh_ifinfo); neigh_ifinfo = NULL; goto out; @@ -524,7 +524,7 @@ batadv_hardif_neigh_create(struct batadv_hard_iface *hard_iface, if (hardif_neigh) goto out;
- if (!atomic_inc_not_zero(&hard_iface->refcount)) + if (!kref_get_unless_zero(&hard_iface->refcount)) goto out;
hardif_neigh = kzalloc(sizeof(*hardif_neigh), GFP_ATOMIC); @@ -635,7 +635,7 @@ batadv_neigh_node_new(struct batadv_orig_node *orig_node, if (!neigh_node) goto out;
- if (!atomic_inc_not_zero(&hard_iface->refcount)) { + if (!kref_get_unless_zero(&hard_iface->refcount)) { kfree(neigh_node); neigh_node = NULL; goto out; diff --git a/net/batman-adv/types.h b/net/batman-adv/types.h index 68ca39e..74cb263 100644 --- a/net/batman-adv/types.h +++ b/net/batman-adv/types.h @@ -111,7 +111,7 @@ struct batadv_hard_iface { struct net_device *net_dev; u8 num_bcasts; struct kobject *hardif_obj; - atomic_t refcount; + struct kref refcount; struct packet_type batman_adv_ptype; struct net_device *soft_iface; struct rcu_head rcu;