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authorChuck Lever <chuck.lever@oracle.com>2012-09-15 01:24:02 +0400
committerTrond Myklebust <Trond.Myklebust@netapp.com>2012-10-02 02:33:33 +0400
commitba9b584c1dc37851d9c6ca6d0d2ccba55d9aad04 (patch)
treed74fa5a04f928d5c508594f285381b41bfe4ac3c /net/sunrpc
parent1b63a75180c6c65c71655c250a4e6b578ba7d1c0 (diff)
downloadlinux-ba9b584c1dc37851d9c6ca6d0d2ccba55d9aad04.tar.xz
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 <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Diffstat (limited to 'net/sunrpc')
-rw-r--r--net/sunrpc/clnt.c22
1 files changed, 22 insertions, 0 deletions
diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index afbeefab6600..cdc7564b4512 100644
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -548,6 +548,28 @@ struct rpc_clnt *rpc_clone_client(struct rpc_clnt *clnt)
}
EXPORT_SYMBOL_GPL(rpc_clone_client);
+/**
+ * rpc_clone_client_set_auth - Clone an RPC client structure and set its auth
+ *
+ * @clnt: RPC client whose parameters are copied
+ * @auth: security flavor for new client
+ *
+ * Returns a fresh RPC client or an ERR_PTR.
+ */
+struct rpc_clnt *
+rpc_clone_client_set_auth(struct rpc_clnt *clnt, rpc_authflavor_t flavor)
+{
+ struct rpc_create_args args = {
+ .program = clnt->cl_program,
+ .prognumber = clnt->cl_prog,
+ .version = clnt->cl_vers,
+ .authflavor = flavor,
+ .client_name = clnt->cl_principal,
+ };
+ return __rpc_clone_client(&args, clnt);
+}
+EXPORT_SYMBOL_GPL(rpc_clone_client_set_auth);
+
/*
* Kill all tasks for the given client.
* XXX: kill their descendants as well?