Re: [PATCH v3 16/49] nfsd: dynamically allocate the nfsd-filecache shrinker

[Qi Zheng <zhengqi.arch@xxxxxxxxxxxxx>]

On 2023/7/27 16:04, Qi Zheng wrote:
> Use new APIs to dynamically allocate the nfsd-filecache shrinker.
>
> Signed-off-by: Qi Zheng <zhengqi.arch@xxxxxxxxxxxxx>
> Reviewed-by: Muchun Song <songmuchun@xxxxxxxxxxxxx>
> ---
>   fs/nfsd/filecache.c | 22 ++++++++++++----------
>   1 file changed, 12 insertions(+), 10 deletions(-)
>
> diff --git a/fs/nfsd/filecache.c b/fs/nfsd/filecache.c
> index ee9c923192e0..872eb9501965 100644
> --- a/fs/nfsd/filecache.c
> +++ b/fs/nfsd/filecache.c
> @@ -521,11 +521,7 @@ nfsd_file_lru_scan(struct shrinker *s, struct 
> shrink_control *sc)
>         return ret;
>   }
>   
> -static struct shrinker	nfsd_file_shrinker = {
> -       .scan_objects = nfsd_file_lru_scan,
> -       .count_objects = nfsd_file_lru_count,
> -       .seeks = 1,
> -};
> +static struct shrinker *nfsd_file_shrinker;
>   
>   /**
>    * nfsd_file_cond_queue - conditionally unhash and queue a nfsd_file
> @@ -746,12 +742,18 @@ nfsd_file_cache_init(void)
>                 goto out_err;
>         }
>   
> -	ret = register_shrinker(&nfsd_file_shrinker, "nfsd-filecache");
> -       if (ret) {
> -               pr_err("nfsd: failed to register nfsd_file_shrinker: %d\n", 
> ret);
> +       nfsd_file_shrinker = shrinker_alloc(0, "nfsd-filecache");
> +       if (!nfsd_file_shrinker) {
Here should set ret to -ENOMEM, will fix.

> +               pr_err("nfsd: failed to allocate nfsd_file_shrinker\n");
>                 goto out_lru;
>         }
>   
> +	nfsd_file_shrinker->count_objects = nfsd_file_lru_count;
> +       nfsd_file_shrinker->scan_objects = nfsd_file_lru_scan;
> +       nfsd_file_shrinker->seeks = 1;
> +
> +       shrinker_register(nfsd_file_shrinker);
> +
>         ret = lease_register_notifier(&nfsd_file_lease_notifier);
>         if (ret) {
>                 pr_err("nfsd: unable to register lease notifier: %d\n", ret);
> @@ -774,7 +776,7 @@ nfsd_file_cache_init(void)
>   out_notifier:
>         lease_unregister_notifier(&nfsd_file_lease_notifier);
>   out_shrinker:
> -       unregister_shrinker(&nfsd_file_shrinker);
> +       shrinker_free(nfsd_file_shrinker);
>   out_lru:
>         list_lru_destroy(&nfsd_file_lru);
>   out_err:
> @@ -891,7 +893,7 @@ nfsd_file_cache_shutdown(void)
>                 return;
>   
>   	lease_unregister_notifier(&nfsd_file_lease_notifier);
> -       unregister_shrinker(&nfsd_file_shrinker);
> +       shrinker_free(nfsd_file_shrinker);
>         /*
>          * make sure all callers of nfsd_file_lru_cb are done before
>          * calling nfsd_file_cache_purge