3 files changed, 52 insertions, 0 deletions

diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index bf4f5ffda703..067d144d141b 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -1651,6 +1651,50 @@ static void nfs_access_free_entry(struct nfs_access_entry *entry)
         smp_mb__after_atomic_dec();
 }
 
+int nfs_access_cache_shrinker(int nr_to_scan, gfp_t gfp_mask)
+{
+        LIST_HEAD(head);
+        struct nfs_inode *nfsi;
+        struct nfs_access_entry *cache;
+
+        spin_lock(&nfs_access_lru_lock);
+restart:
+        list_for_each_entry(nfsi, &nfs_access_lru_list, access_cache_inode_lru) {
+                struct inode *inode;
+
+                if (nr_to_scan-- == 0)
+                        break;
+                inode = igrab(&nfsi->vfs_inode);
+                if (inode == NULL)
+                        continue;
+                spin_lock(&inode->i_lock);
+                if (list_empty(&nfsi->access_cache_entry_lru))
+                        goto remove_lru_entry;
+                cache = list_entry(nfsi->access_cache_entry_lru.next,
+                                struct nfs_access_entry, lru);
+                list_move(&cache->lru, &head);
+                rb_erase(&cache->rb_node, &nfsi->access_cache);
+                if (!list_empty(&nfsi->access_cache_entry_lru))
+                        list_move_tail(&nfsi->access_cache_inode_lru,
+                                        &nfs_access_lru_list);
+                else {
+remove_lru_entry:
+                        list_del_init(&nfsi->access_cache_inode_lru);
+                        clear_bit(NFS_INO_ACL_LRU_SET, &nfsi->flags);
+                }
+                spin_unlock(&inode->i_lock);
+                iput(inode);
+                goto restart;
+        }
+        spin_unlock(&nfs_access_lru_lock);
+        while (!list_empty(&head)) {
+                cache = list_entry(head.next, struct nfs_access_entry, lru);
+                list_del(&cache->lru);
+                nfs_access_free_entry(cache);
+        }
+        return (atomic_long_read(&nfs_access_nr_entries) / 100) * sysctl_vfs_cache_pressure;
+}
+
 static void __nfs_access_zap_cache(struct inode *inode)
 {
         struct nfs_inode *nfsi = NFS_I(inode);
diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
index e4f4e5def0fc..660e9ff5341c 100644
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h
@@ -66,6 +66,9 @@ extern int nfs4_proc_fs_locations(struct inode *dir, struct dentry *dentry,
                                   struct page *page);
 #endif
 
+/* dir.c */
+extern int nfs_access_cache_shrinker(int nr_to_scan, gfp_t gfp_mask);
+
 /* inode.c */
 extern struct inode *nfs_alloc_inode(struct super_block *sb);
 extern void nfs_destroy_inode(struct inode *);
diff --git a/fs/nfs/super.c b/fs/nfs/super.c
index e8a9bee74d9d..06c321beacfe 100644
--- a/fs/nfs/super.c
+++ b/fs/nfs/super.c
@@ -221,6 +221,8 @@ module_param_call(idmap_cache_timeout, param_set_idmap_timeout, param_get_int,
                  &nfs_idmap_cache_timeout, 0644);
 #endif
 
+static struct shrinker *acl_shrinker;
+
 /*
  * Register the NFS filesystems
  */
@@ -240,6 +242,7 @@ int __init register_nfs_fs(void)
         if (ret < 0)
                 goto error_2;
 #endif
+        acl_shrinker = set_shrinker(DEFAULT_SEEKS, nfs_access_cache_shrinker);
         return 0;
 
 #ifdef CONFIG_NFS_V4
@@ -257,6 +260,8 @@ error_0:
  */
 void __exit unregister_nfs_fs(void)
 {
+        if (acl_shrinker != NULL)
+                remove_shrinker(acl_shrinker);
 #ifdef CONFIG_NFS_V4
         unregister_filesystem(&nfs4_fs_type);
         nfs_unregister_sysctl();