xt_condition: make mutex per-net

The mutex protects per-net resources, so make it per-net too.

Signed-off-by: Jeremy Sowden <jeremy@azazel.net>

diff --git a/extensions/xt_condition.c b/extensions/xt_condition.c
index 1d9d7352f06991e00f820c731cb082419ca6a7bd..e1672985e59b15aa19df1183d6fe801ef7a9852d 100644 (file)
--- a/extensions/xt_condition.c
+++ b/extensions/xt_condition.c
@@ -58,11 +58,10 @@ struct condition_variable {
        char name[sizeof_field(struct xt_condition_mtinfo, name)];
 };
 
-/* proc_lock is a user context only semaphore used for write access */
-/*           to the conditions' list.                               */
-static DEFINE_MUTEX(proc_lock);
-
 struct condition_net {
+       /* proc_lock is a user context only semaphore used for write access */
+       /*           to the conditions' list.                               */
+       struct mutex proc_lock;
        struct list_head conditions_list;
        struct proc_dir_entry *proc_net_condition;
        bool after_clear;
@@ -145,11 +144,11 @@ static int condition_mt_check(const struct xt_mtchk_param *par)
         * Let's acquire the lock, check for the condition and add it
         * or increase the reference counter.
         */
-       mutex_lock(&proc_lock);
+       mutex_lock(&condition_net->proc_lock);
        list_for_each_entry(var, &condition_net->conditions_list, list) {
                if (strcmp(info->name, var->name) == 0) {
                        var->refcount++;
-                       mutex_unlock(&proc_lock);
+                       mutex_unlock(&condition_net->proc_lock);
                        info->condvar = var;
                        return 0;
                }
@@ -158,7 +157,7 @@ static int condition_mt_check(const struct xt_mtchk_param *par)
        /* At this point, we need to allocate a new condition variable. */
        var = kmalloc(sizeof(struct condition_variable), GFP_KERNEL);
        if (var == NULL) {
-               mutex_unlock(&proc_lock);
+               mutex_unlock(&condition_net->proc_lock);
                return -ENOMEM;
        }
 
@@ -168,7 +167,7 @@ static int condition_mt_check(const struct xt_mtchk_param *par)
                           condition_net->proc_net_condition, &condition_proc_fops, var);
        if (var->status_proc == NULL) {
                kfree(var);
-               mutex_unlock(&proc_lock);
+               mutex_unlock(&condition_net->proc_lock);
                return -ENOMEM;
        }
 
@@ -179,7 +178,7 @@ static int condition_mt_check(const struct xt_mtchk_param *par)
        var->enabled  = false;
        wmb();
        list_add(&var->list, &condition_net->conditions_list);
-       mutex_unlock(&proc_lock);
+       mutex_unlock(&condition_net->proc_lock);
        info->condvar = var;
        return 0;
 }
@@ -193,15 +192,15 @@ static void condition_mt_destroy(const struct xt_mtdtor_param *par)
        if (cnet->after_clear)
                return;
 
-       mutex_lock(&proc_lock);
+       mutex_lock(&cnet->proc_lock);
        if (--var->refcount == 0) {
                list_del(&var->list);
                remove_proc_entry(var->name, cnet->proc_net_condition);
-               mutex_unlock(&proc_lock);
+               mutex_unlock(&cnet->proc_lock);
                kfree(var);
                return;
        }
-       mutex_unlock(&proc_lock);
+       mutex_unlock(&cnet->proc_lock);
 }
 
 static struct xt_match condition_mt_reg[] __read_mostly = {
@@ -232,6 +231,8 @@ static const char *const dir_name = "nf_condition";
 static int __net_init condition_net_init(struct net *net)
 {
        struct condition_net *condition_net = condition_pernet(net);
+
+       mutex_init(&condition_net->proc_lock);
        INIT_LIST_HEAD(&condition_net->conditions_list);
        condition_net->proc_net_condition = proc_mkdir(dir_name, net->proc_net);
        if (condition_net->proc_net_condition == NULL)
@@ -247,13 +248,13 @@ static void __net_exit condition_net_exit(struct net *net)
        struct condition_variable *var = NULL;
 
        remove_proc_subtree(dir_name, net->proc_net);
-       mutex_lock(&proc_lock);
+       mutex_lock(&condition_net->proc_lock);
        list_for_each_safe(pos, q, &condition_net->conditions_list) {
                var = list_entry(pos, struct condition_variable, list);
                list_del(pos);
                kfree(var);
        }
-       mutex_unlock(&proc_lock);
+       mutex_unlock(&condition_net->proc_lock);
        condition_net->after_clear = true;
 }
 
@@ -269,7 +270,6 @@ static int __init condition_mt_init(void)
 {
        int ret;
 
-       mutex_init(&proc_lock);
        ret = register_pernet_subsys(&condition_net_ops);
        if (ret != 0)
                return ret;