sunrpc: Hash uids by first computing their value in the initial userns

In svcauth_unix introduce a helper unix_gid_hash as otherwise the
expresion to generate the hash value is just too long.

Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>

1 files changed, 7 insertions, 2 deletions

diff --git a/net/sunrpc/svcauth_unix.c b/net/sunrpc/svcauth_unix.c
index 92166b57ec7a..faf17195a9fd 100644
--- a/net/sunrpc/svcauth_unix.c
+++ b/net/sunrpc/svcauth_unix.c
@@ -419,6 +419,11 @@ struct unix_gid {
         struct group_info       *gi;
 };
 
+static int unix_gid_hash(kuid_t uid)
+{
+        return hash_long(from_kuid(&init_user_ns, uid), GID_HASHBITS);
+}
+
 static void unix_gid_put(struct kref *kref)
 {
         struct cache_head *item = container_of(kref, struct cache_head, ref);
@@ -530,7 +535,7 @@ static int unix_gid_parse(struct cache_detail *cd,
                 ug.h.expiry_time = expiry;
                 ch = sunrpc_cache_update(cd,
                                          &ug.h, &ugp->h,
-                                         hash_long(uid, GID_HASHBITS));
+                                         unix_gid_hash(uid));
                 if (!ch)
                         err = -ENOMEM;
                 else {
@@ -621,7 +626,7 @@ static struct unix_gid *unix_gid_lookup(struct cache_detail *cd, kuid_t uid)
         struct cache_head *ch;
 
         ug.uid = uid;
-        ch = sunrpc_cache_lookup(cd, &ug.h, hash_long(uid, GID_HASHBITS));
+        ch = sunrpc_cache_lookup(cd, &ug.h, unix_gid_hash(uid));
         if (ch)
                 return container_of(ch, struct unix_gid, h);
         else