Commit 7f7ab336 authored by Qi Zheng's avatar Qi Zheng Committed by Trond Myklebust
Browse files

NFSv4.2: fix wrong shrinker_id 



Currently, the list_lru::shrinker_id corresponding to the nfs4_xattr
shrinkers is wrong:

>>> prog["nfs4_xattr_cache_lru"].shrinker_id
(int)0
>>> prog["nfs4_xattr_entry_lru"].shrinker_id
(int)0
>>> prog["nfs4_xattr_large_entry_lru"].shrinker_id
(int)0
>>> prog["nfs4_xattr_cache_shrinker"].id
(int)18
>>> prog["nfs4_xattr_entry_shrinker"].id
(int)19
>>> prog["nfs4_xattr_large_entry_shrinker"].id
(int)20

This is not what we expect, which will cause these shrinkers
not to be found in shrink_slab_memcg().

We should assign shrinker::id before calling list_lru_init_memcg(),
so that the corresponding list_lru::shrinker_id will be assigned
the correct value like below:

>>> prog["nfs4_xattr_cache_lru"].shrinker_id
(int)16
>>> prog["nfs4_xattr_entry_lru"].shrinker_id
(int)17
>>> prog["nfs4_xattr_large_entry_lru"].shrinker_id
(int)18
>>> prog["nfs4_xattr_cache_shrinker"].id
(int)16
>>> prog["nfs4_xattr_entry_shrinker"].id
(int)17
>>> prog["nfs4_xattr_large_entry_shrinker"].id
(int)18

So just do it.

Fixes: 95ad37f9 ("NFSv4.2: add client side xattr caching.")
Signed-off-by: default avatarQi Zheng <zhengqi.arch@bytedance.com>
Signed-off-by: default avatarTrond Myklebust <trond.myklebust@hammerspace.com>
parent 6ad477a6

fs/nfs/nfs42xattr.c

+44 −35
Original line number Diff line number Diff line
@@ -991,6 +991,29 @@ static void nfs4_xattr_cache_init_once(void *p) 
	INIT_LIST_HEAD(&cache->dispose);

}



static int nfs4_xattr_shrinker_init(struct shrinker *shrinker,

				    struct list_lru *lru, const char *name)

{

	int ret = 0;



	ret = register_shrinker(shrinker, name);

	if (ret)

		return ret;



	ret = list_lru_init_memcg(lru, shrinker);

	if (ret)

		unregister_shrinker(shrinker);



	return ret;

}



static void nfs4_xattr_shrinker_destroy(struct shrinker *shrinker,

					struct list_lru *lru)

{

	unregister_shrinker(shrinker);

	list_lru_destroy(lru);

}



int __init nfs4_xattr_cache_init(void)

{

	int ret = 0;
@@ -1002,44 +1025,30 @@ int __init nfs4_xattr_cache_init(void) 
	if (nfs4_xattr_cache_cachep == NULL)

		return -ENOMEM;



	ret = list_lru_init_memcg(&nfs4_xattr_large_entry_lru,

	    &nfs4_xattr_large_entry_shrinker);

	if (ret)

		goto out4;



	ret = list_lru_init_memcg(&nfs4_xattr_entry_lru,

	    &nfs4_xattr_entry_shrinker);

	if (ret)

		goto out3;



	ret = list_lru_init_memcg(&nfs4_xattr_cache_lru,

	    &nfs4_xattr_cache_shrinker);

	if (ret)

		goto out2;



	ret = register_shrinker(&nfs4_xattr_cache_shrinker, "nfs-xattr_cache");

	ret = nfs4_xattr_shrinker_init(&nfs4_xattr_cache_shrinker,

				       &nfs4_xattr_cache_lru,

				       "nfs-xattr_cache");

	if (ret)

		goto out1;



	ret = register_shrinker(&nfs4_xattr_entry_shrinker, "nfs-xattr_entry");

	ret = nfs4_xattr_shrinker_init(&nfs4_xattr_entry_shrinker,

				       &nfs4_xattr_entry_lru,

				       "nfs-xattr_entry");

	if (ret)

		goto out;

		goto out2;



	ret = register_shrinker(&nfs4_xattr_large_entry_shrinker,

	ret = nfs4_xattr_shrinker_init(&nfs4_xattr_large_entry_shrinker,

				       &nfs4_xattr_large_entry_lru,

				       "nfs-xattr_large_entry");

	if (!ret)

		return 0;



	unregister_shrinker(&nfs4_xattr_entry_shrinker);

out:

	unregister_shrinker(&nfs4_xattr_cache_shrinker);

out1:

	list_lru_destroy(&nfs4_xattr_cache_lru);

	nfs4_xattr_shrinker_destroy(&nfs4_xattr_entry_shrinker,

				    &nfs4_xattr_entry_lru);

out2:

	list_lru_destroy(&nfs4_xattr_entry_lru);

out3:

	list_lru_destroy(&nfs4_xattr_large_entry_lru);

out4:

	nfs4_xattr_shrinker_destroy(&nfs4_xattr_cache_shrinker,

				    &nfs4_xattr_cache_lru);

out1:

	kmem_cache_destroy(nfs4_xattr_cache_cachep);



	return ret;
@@ -1047,11 +1056,11 @@ int __init nfs4_xattr_cache_init(void) 


void nfs4_xattr_cache_exit(void)

{

	unregister_shrinker(&nfs4_xattr_large_entry_shrinker);

	unregister_shrinker(&nfs4_xattr_entry_shrinker);

	unregister_shrinker(&nfs4_xattr_cache_shrinker);

	list_lru_destroy(&nfs4_xattr_large_entry_lru);

	list_lru_destroy(&nfs4_xattr_entry_lru);

	list_lru_destroy(&nfs4_xattr_cache_lru);

	nfs4_xattr_shrinker_destroy(&nfs4_xattr_large_entry_shrinker,

				    &nfs4_xattr_large_entry_lru);

	nfs4_xattr_shrinker_destroy(&nfs4_xattr_entry_shrinker,

				    &nfs4_xattr_entry_lru);

	nfs4_xattr_shrinker_destroy(&nfs4_xattr_cache_shrinker,

				    &nfs4_xattr_cache_lru);

	kmem_cache_destroy(nfs4_xattr_cache_cachep);

}