NFS: use SUNRPC cache creation and destruction helper for DNS cache

This cache was the first containerized and doesn't use net-aware cache
creation and destruction helpers.
This is a cleanup patch which just makes code looks clearer and reduce amount
of lines of code.

Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

1 files changed, 25 insertions, 35 deletions

diff --git a/fs/nfs/dns_resolve.c b/fs/nfs/dns_resolve.c
index 62c8c4127219..d5ce5f4f0f5f 100644
--- a/fs/nfs/dns_resolve.c
+++ b/fs/nfs/dns_resolve.c
@@ -353,48 +353,39 @@ ssize_t nfs_dns_resolve_name(struct net *net, char *name,
 }
 EXPORT_SYMBOL_GPL(nfs_dns_resolve_name);
 
+static struct cache_detail nfs_dns_resolve_template = {
+        .owner          = THIS_MODULE,
+        .hash_size      = NFS_DNS_HASHTBL_SIZE,
+        .name           = "dns_resolve",
+        .cache_put      = nfs_dns_ent_put,
+        .cache_upcall   = nfs_dns_upcall,
+        .cache_parse    = nfs_dns_parse,
+        .cache_show     = nfs_dns_show,
+        .match          = nfs_dns_match,
+        .init           = nfs_dns_ent_init,
+        .update         = nfs_dns_ent_update,
+        .alloc          = nfs_dns_ent_alloc,
+};
+
+
 int nfs_dns_resolver_cache_init(struct net *net)
 {
-        int err = -ENOMEM;
+        int err;
         struct nfs_net *nn = net_generic(net, nfs_net_id);
-        struct cache_detail *cd;
-        struct cache_head **tbl;
 
-        cd = kzalloc(sizeof(struct cache_detail), GFP_KERNEL);
-        if (cd == NULL)
-                goto err_cd;
-
-        tbl = kzalloc(NFS_DNS_HASHTBL_SIZE * sizeof(struct cache_head *),
-                        GFP_KERNEL);
-        if (tbl == NULL)
-                goto err_tbl;
-
-        cd->owner = THIS_MODULE,
-        cd->hash_size = NFS_DNS_HASHTBL_SIZE,
-        cd->hash_table = tbl,
-        cd->name = "dns_resolve",
-        cd->cache_put = nfs_dns_ent_put,
-        cd->cache_upcall = nfs_dns_upcall,
-        cd->cache_parse = nfs_dns_parse,
-        cd->cache_show = nfs_dns_show,
-        cd->match = nfs_dns_match,
-        cd->init = nfs_dns_ent_init,
-        cd->update = nfs_dns_ent_update,
-        cd->alloc = nfs_dns_ent_alloc,
-
-        nfs_cache_init(cd);
-        err = nfs_cache_register_net(net, cd);
+        nn->nfs_dns_resolve = cache_create_net(&nfs_dns_resolve_template, net);
+        if (IS_ERR(nn->nfs_dns_resolve))
+                return PTR_ERR(nn->nfs_dns_resolve);
+
+        nfs_cache_init(nn->nfs_dns_resolve);
+        err = nfs_cache_register_net(net, nn->nfs_dns_resolve);
         if (err)
                 goto err_reg;
-        nn->nfs_dns_resolve = cd;
         return 0;
 
 err_reg:
-        nfs_cache_destroy(cd);
-        kfree(cd->hash_table);
-err_tbl:
-        kfree(cd);
-err_cd:
+        nfs_cache_destroy(nn->nfs_dns_resolve);
+        cache_destroy_net(nn->nfs_dns_resolve, net);
         return err;
 }
 
@@ -405,8 +396,7 @@ void nfs_dns_resolver_cache_destroy(struct net *net)
 
         nfs_cache_unregister_net(net, cd);
         nfs_cache_destroy(cd);
-        kfree(cd->hash_table);
-        kfree(cd);
+        cache_destroy_net(nn->nfs_dns_resolve, net);
 }
 
 static int rpc_pipefs_event(struct notifier_block *nb, unsigned long event,