[FIX] Preload: dentry balance counter

Use atomic_t instead of int to avoid race conditions

Change-Id: Ie32d46a8c822ef8ef6110832c0fcc14ea1594e9c
Signed-off-by: Vyacheslav Cherkashin <v.cherkashin@samsung.com>

diff --git a/preload/preload_module.c b/preload/preload_module.c
index 580c066..0563eb7 100644 (file)
--- a/preload/preload_module.c
+++ b/preload/preload_module.c
@@ -41,7 +41,7 @@ struct us_priv {
        unsigned long origin;
 };
 
-static int get_put_counter;
+static atomic_t dentry_balance = ATOMIC_INIT(0);
 
 enum preload_status_t {
        SWAP_PRELOAD_NOT_READY = 0,
@@ -69,7 +69,7 @@ static inline struct process_data *__get_process_data(struct uretprobe *rp)
 
 static struct dentry *__get_dentry(struct dentry *dentry)
 {
-       get_put_counter++;
+       atomic_inc(&dentry_balance);
        return dget(dentry);
 }
 
@@ -129,7 +129,7 @@ struct dentry *get_dentry(const char *filepath)
 
 void put_dentry(struct dentry *dentry)
 {
-       get_put_counter--;
+       atomic_dec(&dentry_balance);
        dput(dentry);
 }
 
@@ -980,6 +980,8 @@ out_err:
 
 static void preload_module_exit(void)
 {
+       int balance;
+
        us_manager_unreg_cb(__preload_cbs_start_h);
        us_manager_unreg_cb(__preload_cbs_stop_h);
        unregister_preload_probes();
@@ -990,7 +992,10 @@ static void preload_module_exit(void)
        preload_storage_exit();
        preload_debugfs_exit();
 
-       WARN(get_put_counter, "Bad GET/PUT balance: %d\n", get_put_counter);
+       balance = atomic_read(&dentry_balance);
+       atomic_set(&dentry_balance, 0);
+
+       WARN(balance, "Bad GET/PUT dentry balance: %d\n", balance);
 }
 
 SWAP_LIGHT_INIT_MODULE(NULL, preload_module_init, preload_module_exit,