dm log: use standard kernel module refcount

Avoid private module usage accounting by removing 'use' from
dm_dirty_log_internal.  The standard module reference counting is
sufficient.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

diff --git a/drivers/md/dm-log.c b/drivers/md/dm-log.c
index 737961f..094c8f0 100644 (file)
--- a/drivers/md/dm-log.c
+++ b/drivers/md/dm-log.c
@@ -20,7 +20,6 @@ struct dm_dirty_log_internal {
        struct dm_dirty_log_type *type;
 
        struct list_head list;
-       long use;
 };
 
 static LIST_HEAD(_log_types);
@@ -44,12 +43,8 @@ static struct dm_dirty_log_internal *_get_dirty_log_type(const char *name)
        spin_lock(&_lock);
 
        log_type = __find_dirty_log_type(name);
-       if (log_type) {
-               if (!log_type->use && !try_module_get(log_type->type->module))
-                       log_type = NULL;
-               else
-                       log_type->use++;
-       }
+       if (log_type && !try_module_get(log_type->type->module))
+               log_type = NULL;
 
        spin_unlock(&_lock);
 
@@ -120,10 +115,7 @@ static void put_type(struct dm_dirty_log_type *type)
        if (!log_type)
                goto out;
 
-       if (!--log_type->use)
-               module_put(type->module);
-
-       BUG_ON(log_type->use < 0);
+       module_put(type->module);
 
 out:
        spin_unlock(&_lock);
@@ -173,11 +165,6 @@ int dm_dirty_log_type_unregister(struct dm_dirty_log_type *type)
                return -EINVAL;
        }
 
-       if (log_type->use) {
-               spin_unlock(&_lock);
-               return -ETXTBSY;
-       }
-
        list_del(&log_type->list);
 
        spin_unlock(&_lock);