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author | Chuck Lever <chuck.lever@oracle.com> | 2012-09-14 17:24:02 -0400 |
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committer | Trond Myklebust <Trond.Myklebust@netapp.com> | 2012-10-01 15:33:33 -0700 |
commit | ba9b584c1dc37851d9c6ca6d0d2ccba55d9aad04 (patch) | |
tree | d74fa5a04f928d5c508594f285381b41bfe4ac3c /net | |
parent | 1b63a75180c6c65c71655c250a4e6b578ba7d1c0 (diff) | |
download | linux-3.10-ba9b584c1dc37851d9c6ca6d0d2ccba55d9aad04.tar.gz linux-3.10-ba9b584c1dc37851d9c6ca6d0d2ccba55d9aad04.tar.bz2 linux-3.10-ba9b584c1dc37851d9c6ca6d0d2ccba55d9aad04.zip |
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')
-rw-r--r-- | net/sunrpc/clnt.c | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c index afbeefab660..cdc7564b451 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? |