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: stable@kernel.org
Signed-off-by: Cheng Renquan <crquan@gmail.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Reviewed-by: Alasdair G Kergon <agk@redhat.com>
Reviewed-by: Jonathan Brassow <jbrassow@redhat.com>
diff --git a/drivers/md/dm-target.c b/drivers/md/dm-target.c
index 7decf10..db72c94 100644
--- a/drivers/md/dm-target.c
+++ b/drivers/md/dm-target.c
@@ -18,7 +18,6 @@
struct target_type tt;
struct list_head list;
- long use;
};
static LIST_HEAD(_targets);
@@ -44,12 +43,8 @@
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 @@
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 @@
BUG();
}
- if (ti->use) {
- DMCRIT("Attempt to unregister target still in use: %s",
- t->name);
- BUG();
- }
-
list_del(&ti->list);
kfree(ti);