NFSv4.1: Enable state protection

Use the EXCHGID4_FLAG_BIND_PRINC_STATEID exchange_id flag to enable
stateid protection. This means that if we create a stateid using a
particular principal, then we must use the same principal if we
want to change that state.
IOW: if we OPEN a file using a particular credential, then we have
to use the same credential in subsequent OPEN_DOWNGRADE, CLOSE,
or DELEGRETURN operations that use that stateid.

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

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 98f0df3ee50d181fd9653358207075c49a518934..7490359f6c60320c6e4f1b8380d4bc5542f3517f 100644 (file)
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -5528,7 +5528,8 @@ int nfs4_proc_exchange_id(struct nfs_client *clp, struct rpc_cred *cred)
        struct nfs41_exchange_id_args args = {
                .verifier = &verifier,
                .client = clp,
-               .flags = EXCHGID4_FLAG_SUPP_MOVED_REFER,
+               .flags = EXCHGID4_FLAG_SUPP_MOVED_REFER |
+                       EXCHGID4_FLAG_BIND_PRINC_STATEID,
        };
        struct nfs41_exchange_id_res res = {
                0