NFS: Don't free a state ID the server does not recognize

The result of a TEST_STATEID operation can indicate a few different
things:

  o If NFS_OK is returned, then the client can continue using the
    state ID under test, and skip recovery.

  o RFC 5661 says that if the state ID was revoked, then the client
    must perform an explicit FREE_STATEID before trying to re-open.

  o If the server doesn't recognize the state ID at all, then no
    FREE_STATEID is needed, and the client can immediately continue
    with open recovery.

Let's err on the side of caution: if the server clearly tells us the
state ID is unknown, we skip the FREE_STATEID.  For any other error,
we issue a FREE_STATEID.  Sometimes that FREE_STATEID will be
unnecessary, but leaving unused state IDs on the server needlessly
ties up resources.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index af3abf9..afd61d7 100644 (file)
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -1764,7 +1764,8 @@ static int nfs41_check_expired_stateid(struct nfs4_state *state, nfs4_stateid *s
        if (state->flags & flags) {
                status = nfs41_test_stateid(server, stateid);
                if (status != NFS_OK) {
-                       nfs41_free_stateid(server, stateid);
+                       if (status != -NFS4ERR_BAD_STATEID)
+                               nfs41_free_stateid(server, stateid);
                        state->flags &= ~flags;
                }
        }
@@ -4697,7 +4698,9 @@ static int nfs41_check_expired_locks(struct nfs4_state *state)
                if (lsp->ls_flags & NFS_LOCK_INITIALIZED) {
                        status = nfs41_test_stateid(server, &lsp->ls_stateid);
                        if (status != NFS_OK) {
-                               nfs41_free_stateid(server, &lsp->ls_stateid);
+                               if (status != -NFS4ERR_BAD_STATEID)
+                                       nfs41_free_stateid(server,
+                                                       &lsp->ls_stateid);
                                lsp->ls_flags &= ~NFS_LOCK_INITIALIZED;
                                ret = status;
                        }