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

From: Qi Zheng
Date: Thu Jul 27 2023 - 05:19:13 EST




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