percpu-refcount: Add a WARN() for ref going negative
authorKent Overstreet <kmo@daterainc.com>
Mon, 6 Jan 2014 21:13:26 +0000 (13:13 -0800)
committerTejun Heo <tj@kernel.org>
Tue, 21 Jan 2014 09:40:56 +0000 (04:40 -0500)
commit687b0ad2751ca8ea418396fa780e22571fba76a8
tree5603037cfd39eef273ec61186e37f9df000fce6f
parent6ce4eac1f600b34f2f7f58f9cd8f0503d79e42ae
percpu-refcount: Add a WARN() for ref going negative

AIO had a missing get, which led to an ioctx leak - after percpu_ref_kill() the
ref was 0 so percpu_ref_put() never saw it hit 0.

This wasn't noticed at the time because it all happened completely silently,
this adds a WARN() which would've caught the aio bug.

tj: Used WARN_ONCE() instead of WARN().

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
lib/percpu-refcount.c