On Sun, Sep 27, 2020 at 02:26:52PM +0800, Ming Lei wrote: > MD code uses perpcu-refcount internal to check if this percpu-refcount > variable is initialized, this way is a hack. > > Add percpu_ref_is_initialized for MD so that the hack can be avoided. > > Acked-by: Song Liu <[email protected]> > Suggested-by: Jens Axboe <[email protected]> > Tested-by: Veronika Kabatova <[email protected]> > Cc: Song Liu <[email protected]> > Cc: [email protected] > Cc: Sagi Grimberg <[email protected]> > Cc: Tejun Heo <[email protected]> > Cc: Christoph Hellwig <[email protected]> > Cc: Jens Axboe <[email protected]> > Cc: Bart Van Assche <[email protected]> > Signed-off-by: Ming Lei <[email protected]> > --- > drivers/md/md.c | 2 +- > include/linux/percpu-refcount.h | 1 + > lib/percpu-refcount.c | 6 ++++++ > 3 files changed, 8 insertions(+), 1 deletion(-) > > diff --git a/drivers/md/md.c b/drivers/md/md.c > index de8419b7ae98..241ff618d84e 100644 > --- a/drivers/md/md.c > +++ b/drivers/md/md.c > @@ -5631,7 +5631,7 @@ static void no_op(struct percpu_ref *r) {} > > int mddev_init_writes_pending(struct mddev *mddev) > { > - if (mddev->writes_pending.percpu_count_ptr) > + if (percpu_ref_is_initialized(&mddev->writes_pending)) > return 0;
I'd much rather use a flag in the containing mddev structure then exposing this new "API". That mddev code is pretty gross to be honest, we should just initialize the percpu_ref once instea of such a hack.
