dm target: use module refcount directly

The tt_internal's 'use' field is superfluous: the module's refcount can do the work properly. An acceptable side-effect is that this increases the reference counts reported by 'lsmod'. Remove the superfluous test when removing a target module. [Crash possible without this on SMP - agk] Cc: [email protected] Signed-off-by: Cheng Renquan <[email protected]> Signed-off-by: Alasdair G Kergon <[email protected]> Reviewed-by: Alasdair G Kergon <[email protected]> Reviewed-by: Jonathan Brassow <[email protected]>
redpig · Apr 2, 2009 · 5642b8a · 5642b8a
1 parent 35bf659
commit 5642b8a
Showing 1 changed file with 3 additions and 17 deletions.
diff --git a/drivers/md/dm-target.c b/drivers/md/dm-target.c
@@ -18,7 +18,6 @@ struct tt_internal {
 	struct target_type tt;
 
 	struct list_head list;
-	long use;
 };
 
 static LIST_HEAD(_targets);
@@ -44,12 +43,8 @@ static struct tt_internal *get_target_type(const char *name)
 	down_read(&_lock);
 
 	ti = __find_target_type(name);
-	if (ti) {
-		if ((ti->use == 0) && !try_module_get(ti->tt.module))
-			ti = NULL;
-		else
-			ti->use++;
-	}
+	if (ti && !try_module_get(ti->tt.module))
+		ti = NULL;
 
 	up_read(&_lock);
 	return ti;
@@ -77,10 +72,7 @@ void dm_put_target_type(struct target_type *t)
 	struct tt_internal *ti = (struct tt_internal *) t;
 
 	down_read(&_lock);
-	if (--ti->use == 0)
-		module_put(ti->tt.module);
-
-	BUG_ON(ti->use < 0);
+	module_put(ti->tt.module);
 	up_read(&_lock);
 
 	return;
@@ -140,12 +132,6 @@ void dm_unregister_target(struct target_type *t)
 		BUG();
 	}
 
-	if (ti->use) {
-		DMCRIT("Attempt to unregister target still in use: %s",
-		       t->name);
-		BUG();
-	}
-
 	list_del(&ti->list);
 	kfree(ti);