On Tue, Sep 20, 2016 at 10:33:57AM +0800, Chao Yu wrote:
> register_shrinker can fail after commit 1d3d4437eae1 ("vmscan: per-node
> deferred work"), we should detect the failure of it, otherwise we may
> fail to register shrinker after raid5 configuration was setup successfully.
>
> Signed-off-by: Chao Yu <yuch...@huawei.com>
> ---
> drivers/md/raid5.c | 7 ++++++-
> 1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
> index 766c3b7..b819a9a 100644
> --- a/drivers/md/raid5.c
> +++ b/drivers/md/raid5.c
> @@ -6632,7 +6632,12 @@ static struct r5conf *setup_conf(struct mddev *mddev)
> conf->shrinker.count_objects = raid5_cache_count;
> conf->shrinker.batch = 128;
> conf->shrinker.flags = 0;
> - register_shrinker(&conf->shrinker);
> + if (register_shrinker(&conf->shrinker)) {
> + printk(KERN_ERR
> + "md/raid:%s: couldn't register shrinker.\n",
> + mdname(mddev));
> + goto abort;
> + }
>
> sprintf(pers_name, "raid%d", mddev->new_level);
> conf->thread = md_register_thread(raid5d, mddev, pers_name);
shrinker isn't fatal for raid5. Idealy we can ignore the error and stop
automatically stripe cache increase, but probable it's not worthy the effort.
Applied the patch.
Also the free_conf need better way to check if shrinker register successes. I
add another patch to fix it.
Thanks,
Shaohua
