From: Cheng Renquan <crquan@gmail.com>
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>
---
drivers/md/dm-target.c | 20 +++-----------------
1 files changed, 3 insertions(+), 17 deletions(-)
Index: linux-2.6.29/drivers/md/dm-target.c
===================================================================
--- linux-2.6.29.orig/drivers/md/dm-target.c 2009-04-02 16:34:52.000000000 +0100
+++ linux-2.6.29/drivers/md/dm-target.c 2009-04-02 16:45:23.000000000 +0100
@@ -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_ty
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_ty
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_
BUG();
}
- if (ti->use) {
- DMCRIT("Attempt to unregister target still in use: %s",
- t->name);
- BUG();
- }
-
list_del(&ti->list);
kfree(ti);