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>

1 files changed, 3 insertions, 16 deletions

diff --git a/drivers/md/dm-log.c b/drivers/md/dm-log.c
index 737961f275c1..094c8f0e0097 100644
--- 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);