SUNRPC: Fix a lock recursion in the auth_gss downcall

 When we look up a new cred in the auth_gss downcall so that we can stuff
 the credcache, we do not want that lookup to queue up an upcall in order
 to initialise it. To do an upcall here not only redundant, but since we
 are already holding the inode->i_mutex, it will trigger a lock recursion.

 This patch allows rpcauth cache searches to indicate that they can cope
 with uninitialised credentials.

 Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/include/linux/sunrpc/auth.h b/include/linux/sunrpc/auth.h
index b68c11a2d6d..bfc5fb27953 100644
--- a/include/linux/sunrpc/auth.h
+++ b/include/linux/sunrpc/auth.h
@@ -50,6 +50,7 @@ struct rpc_cred {
 };
 #define RPCAUTH_CRED_LOCKED     0x0001
 #define RPCAUTH_CRED_UPTODATE   0x0002
+#define RPCAUTH_CRED_NEW        0x0004
 
 #define RPCAUTH_CRED_MAGIC      0x0f4aa4f0
 
@@ -87,6 +88,10 @@ struct rpc_auth {
                                                  * uid/gid, fs[ug]id, gids)
                                                  */
 
+/* Flags for rpcauth_lookupcred() */
+#define RPCAUTH_LOOKUP_NEW              0x01    /* Accept an uninitialised cred */
+#define RPCAUTH_LOOKUP_ROOTCREDS        0x02    /* This really ought to go! */
+
 /*
  * Client authentication ops
  */