knfsd: Lockless lookup of NFSv4 identities.

Enable RCU protected lookups of the NFSv4 idmap.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

1 files changed, 6 insertions, 5 deletions

diff --git a/fs/nfsd/nfs4idmap.c b/fs/nfsd/nfs4idmap.c
index a5bb76593ce7..bf137fec33ff 100644
--- a/fs/nfsd/nfs4idmap.c
+++ b/fs/nfsd/nfs4idmap.c
@@ -65,6 +65,7 @@ struct ent {
         u32               id;
         char              name[IDMAP_NAMESZ];
         char              authname[IDMAP_NAMESZ];
+        struct rcu_head   rcu_head;
 };
 
 /* Common entry handling */
@@ -89,7 +90,7 @@ static void
 ent_put(struct kref *ref)
 {
         struct ent *map = container_of(ref, struct ent, h.ref);
-        kfree(map);
+        kfree_rcu(map, rcu_head);
 }
 
 static struct cache_head *
@@ -264,8 +265,8 @@ out:
 static struct ent *
 idtoname_lookup(struct cache_detail *cd, struct ent *item)
 {
-        struct cache_head *ch = sunrpc_cache_lookup(cd, &item->h,
-                                                    idtoname_hash(item));
+        struct cache_head *ch = sunrpc_cache_lookup_rcu(cd, &item->h,
+                                                        idtoname_hash(item));
         if (ch)
                 return container_of(ch, struct ent, h);
         else
@@ -422,8 +423,8 @@ out:
 static struct ent *
 nametoid_lookup(struct cache_detail *cd, struct ent *item)
 {
-        struct cache_head *ch = sunrpc_cache_lookup(cd, &item->h,
-                                                    nametoid_hash(item));
+        struct cache_head *ch = sunrpc_cache_lookup_rcu(cd, &item->h,
+                                                        nametoid_hash(item));
         if (ch)
                 return container_of(ch, struct ent, h);
         else