From ba9b584c1dc37851d9c6ca6d0d2ccba55d9aad04 Mon Sep 17 00:00:00 2001 From: Chuck Lever Date: Fri, 14 Sep 2012 17:24:02 -0400 Subject: SUNRPC: Introduce rpc_clone_client_set_auth() An ULP is supposed to be able to replace a GSS rpc_auth object with another GSS rpc_auth object using rpcauth_create(). However, rpcauth_create() in 3.5 reliably fails with -EEXIST in this case. This is because when gss_create() attempts to create the upcall pipes, sometimes they are already there. For example if a pipe FS mount event occurs, or a previous GSS flavor was in use for this rpc_clnt. It turns out that's not the only problem here. While working on a fix for the above problem, we noticed that replacing an rpc_clnt's rpc_auth is not safe, since dereferencing the cl_auth field is not protected in any way. So we're deprecating the ability of rpcauth_create() to switch an rpc_clnt's security flavor during normal operation. Instead, let's add a fresh API that clones an rpc_clnt and gives the clone a new flavor before it's used. This makes immediate use of the new __rpc_clone_client() helper. This can be used in a similar fashion to rpcauth_create() when a client is hunting for the correct security flavor. Instead of replacing an rpc_clnt's security flavor in a loop, the ULP replaces the whole rpc_clnt. To fix the -EEXIST problem, any ULP logic that relies on replacing an rpc_clnt's rpc_auth with rpcauth_create() must be changed to use this API instead. Signed-off-by: Chuck Lever Signed-off-by: Trond Myklebust --- include/linux/sunrpc/clnt.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include') diff --git a/include/linux/sunrpc/clnt.h b/include/linux/sunrpc/clnt.h index 523547ecfee..34206b84d8d 100644 --- a/include/linux/sunrpc/clnt.h +++ b/include/linux/sunrpc/clnt.h @@ -130,6 +130,8 @@ struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *, const struct rpc_program *, u32); void rpc_task_reset_client(struct rpc_task *task, struct rpc_clnt *clnt); struct rpc_clnt *rpc_clone_client(struct rpc_clnt *); +struct rpc_clnt *rpc_clone_client_set_auth(struct rpc_clnt *, + rpc_authflavor_t); void rpc_shutdown_client(struct rpc_clnt *); void rpc_release_client(struct rpc_clnt *); void rpc_task_release_client(struct rpc_task *); -- cgit v1.2.3-70-g09d2