diff options
author | Tejun Heo <tj@kernel.org> | 2014-06-28 08:10:14 -0400 |
---|---|---|
committer | Tejun Heo <tj@kernel.org> | 2014-06-28 08:10:14 -0400 |
commit | 9a1049da9bd2cd83fe11d46433e603c193aa9c71 (patch) | |
tree | 007d2843abf0f064c294659334e69e297ffc2b74 /drivers/target | |
parent | 7d742075120deb831c7b94c268ca20d409e91d60 (diff) |
percpu-refcount: require percpu_ref to be exited explicitly
Currently, a percpu_ref undoes percpu_ref_init() automatically by
freeing the allocated percpu area when the percpu_ref is killed.
While seemingly convenient, this has the following niggles.
* It's impossible to re-init a released reference counter without
going through re-allocation.
* In the similar vein, it's impossible to initialize a percpu_ref
count with static percpu variables.
* We need and have an explicit destructor anyway for failure paths -
percpu_ref_cancel_init().
This patch removes the automatic percpu counter freeing in
percpu_ref_kill_rcu() and repurposes percpu_ref_cancel_init() into a
generic destructor now named percpu_ref_exit(). percpu_ref_destroy()
is considered but it gets confusing with percpu_ref_kill() while
"exit" clearly indicates that it's the counterpart of
percpu_ref_init().
All percpu_ref_cancel_init() users are updated to invoke
percpu_ref_exit() instead and explicit percpu_ref_exit() calls are
added to the destruction path of all percpu_ref users.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Benjamin LaHaise <bcrl@kvack.org>
Cc: Kent Overstreet <kmo@daterainc.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Benjamin LaHaise <bcrl@kvack.org>
Cc: Nicholas A. Bellinger <nab@linux-iscsi.org>
Cc: Li Zefan <lizefan@huawei.com>
Diffstat (limited to 'drivers/target')
-rw-r--r-- | drivers/target/target_core_tpg.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/drivers/target/target_core_tpg.c b/drivers/target/target_core_tpg.c index c036595b17cf..fddfae61222f 100644 --- a/drivers/target/target_core_tpg.c +++ b/drivers/target/target_core_tpg.c | |||
@@ -825,7 +825,7 @@ int core_tpg_add_lun( | |||
825 | 825 | ||
826 | ret = core_dev_export(dev, tpg, lun); | 826 | ret = core_dev_export(dev, tpg, lun); |
827 | if (ret < 0) { | 827 | if (ret < 0) { |
828 | percpu_ref_cancel_init(&lun->lun_ref); | 828 | percpu_ref_exit(&lun->lun_ref); |
829 | return ret; | 829 | return ret; |
830 | } | 830 | } |
831 | 831 | ||
@@ -880,5 +880,7 @@ int core_tpg_post_dellun( | |||
880 | lun->lun_status = TRANSPORT_LUN_STATUS_FREE; | 880 | lun->lun_status = TRANSPORT_LUN_STATUS_FREE; |
881 | spin_unlock(&tpg->tpg_lun_lock); | 881 | spin_unlock(&tpg->tpg_lun_lock); |
882 | 882 | ||
883 | percpu_ref_exit(&lun->lun_ref); | ||
884 | |||
883 | return 0; | 885 | return 0; |
884 | } | 886 | } |