On 11/23/2018 11:04 AM, Hans Holmberg wrote:
Great catch Javier! Nice refactoring work too. Reviewed-by: Hans Holmberg <hans.holmberg@xxxxxxxxxxxx> On Thu, Nov 22, 2018 at 2:47 PM Javier González <javier@xxxxxxxxxxx> wrote:The current kref implementation around pblk global caches triggers a false positive on refcount_inc_checked() (when called) as the kref is initialized to 0. Instead of usint kref_inc() on a 0 reference, which is in principle correct, use kref_init() to avoid the check. This is also more explicit about what actually happens on cache creation. In the process, do a small refactoring to use kref helpers. Signed-off-by: Javier González <javier@xxxxxxxxxxxx> --- drivers/lightnvm/pblk-init.c | 14 +++++--------- 1 file changed, 5 insertions(+), 9 deletions(-) diff --git a/drivers/lightnvm/pblk-init.c b/drivers/lightnvm/pblk-init.c index 13822594647c..e225bd60cbb4 100644 --- a/drivers/lightnvm/pblk-init.c +++ b/drivers/lightnvm/pblk-init.c @@ -350,23 +350,19 @@ static int pblk_create_global_caches(void) static int pblk_get_global_caches(void) { - int ret; + int ret = 0; mutex_lock(&pblk_caches.mutex); - if (kref_read(&pblk_caches.kref) > 0) { - kref_get(&pblk_caches.kref); - mutex_unlock(&pblk_caches.mutex); - return 0; - } + if (kref_get_unless_zero(&pblk_caches.kref)) + goto out; ret = pblk_create_global_caches(); - if (!ret) - kref_get(&pblk_caches.kref); + kref_init(&pblk_caches.kref); +out: mutex_unlock(&pblk_caches.mutex); - return ret; } -- 2.7.4
Picked up for 4.21.
