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 --- 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/originator.c | 15 +++++++++------ net/batman-adv/routing.c | 5 +++-- net/batman-adv/types.h | 2 +- 3 files changed, 13 insertions(+), 9 deletions(-)
diff --git a/net/batman-adv/originator.c b/net/batman-adv/originator.c index eb366c5..4874526 100644 --- a/net/batman-adv/originator.c +++ b/net/batman-adv/originator.c @@ -326,7 +326,7 @@ batadv_orig_ifinfo_get(struct batadv_orig_node *orig_node, if (tmp->if_outgoing != if_outgoing) continue;
- if (!atomic_inc_not_zero(&tmp->refcount)) + if (!kref_get_unless_zero(&tmp->refcount)) continue;
orig_ifinfo = tmp; @@ -377,7 +377,8 @@ batadv_orig_ifinfo_new(struct batadv_orig_node *orig_node, orig_ifinfo->batman_seqno_reset = reset_time; orig_ifinfo->if_outgoing = if_outgoing; INIT_HLIST_NODE(&orig_ifinfo->list); - atomic_set(&orig_ifinfo->refcount, 2); + kref_init(&orig_ifinfo->refcount); + kref_get(&orig_ifinfo->refcount); hlist_add_head_rcu(&orig_ifinfo->list, &orig_node->ifinfo_list); out: @@ -704,12 +705,15 @@ int batadv_hardif_neigh_seq_print_text(struct seq_file *seq, void *offset) /** * batadv_orig_ifinfo_release - release orig_ifinfo from lists and queue for * free after rcu grace period - * @orig_ifinfo: the orig_ifinfo object to release + * @ref: kref pointer of the orig_ifinfo */ -static void batadv_orig_ifinfo_release(struct batadv_orig_ifinfo *orig_ifinfo) +static void batadv_orig_ifinfo_release(struct kref *ref) { + struct batadv_orig_ifinfo *orig_ifinfo; struct batadv_neigh_node *router;
+ orig_ifinfo = container_of(ref, struct batadv_orig_ifinfo, refcount); + if (orig_ifinfo->if_outgoing != BATADV_IF_DEFAULT) batadv_hardif_free_ref(orig_ifinfo->if_outgoing);
@@ -728,8 +732,7 @@ static void batadv_orig_ifinfo_release(struct batadv_orig_ifinfo *orig_ifinfo) */ void batadv_orig_ifinfo_free_ref(struct batadv_orig_ifinfo *orig_ifinfo) { - if (atomic_dec_and_test(&orig_ifinfo->refcount)) - batadv_orig_ifinfo_release(orig_ifinfo); + kref_put(&orig_ifinfo->refcount, batadv_orig_ifinfo_release); }
/** diff --git a/net/batman-adv/routing.c b/net/batman-adv/routing.c index 0ba5993..99fd1df 100644 --- a/net/batman-adv/routing.c +++ b/net/batman-adv/routing.c @@ -25,6 +25,7 @@ #include <linux/etherdevice.h> #include <linux/if_ether.h> #include <linux/jiffies.h> +#include <linux/kref.h> #include <linux/netdevice.h> #include <linux/printk.h> #include <linux/rculist.h> @@ -497,7 +498,7 @@ batadv_find_router(struct batadv_priv *bat_priv,
hlist_for_each_entry_rcu(cand, &orig_node->ifinfo_list, list) { /* acquire some structures and references ... */ - if (!atomic_inc_not_zero(&cand->refcount)) + if (!kref_get_unless_zero(&cand->refcount)) continue;
cand_router = rcu_dereference(cand->router); @@ -524,7 +525,7 @@ batadv_find_router(struct batadv_priv *bat_priv, /* mark the first possible candidate */ if (!first_candidate) { atomic_inc(&cand_router->refcount); - atomic_inc(&cand->refcount); + kref_get(&cand->refcount); first_candidate = cand; first_candidate_router = cand_router; } diff --git a/net/batman-adv/types.h b/net/batman-adv/types.h index 7831bf0..a5e4310 100644 --- a/net/batman-adv/types.h +++ b/net/batman-adv/types.h @@ -141,7 +141,7 @@ struct batadv_orig_ifinfo { u32 last_real_seqno; u8 last_ttl; unsigned long batman_seqno_reset; - atomic_t refcount; + struct kref refcount; struct rcu_head rcu; };