NFSD: Add nfsd4_encode_open_delegation4()

To better align our implementation with the XDR specification,
refactor the part of nfsd4_encode_open() that encodes delegation
metadata.

As part of that refactor, remove an unnecessary BUG() call site and
a comment that appears to be stale.

Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index 4a1d428066cea5816514c6d81de09b087360921d..cacd069497968cbbbdb66bbc9d2872ec0ee91747 100644 (file)
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -4174,13 +4174,43 @@ nfsd4_encode_open_none_delegation4(struct xdr_stream *xdr,
        return status;
 }
 
+static __be32
+nfsd4_encode_open_delegation4(struct xdr_stream *xdr, struct nfsd4_open *open)
+{
+       __be32 status;
+
+       /* delegation_type */
+       if (xdr_stream_encode_u32(xdr, open->op_delegate_type) != XDR_UNIT)
+               return nfserr_resource;
+       switch (open->op_delegate_type) {
+       case NFS4_OPEN_DELEGATE_NONE:
+               status = nfs_ok;
+               break;
+       case NFS4_OPEN_DELEGATE_READ:
+               /* read */
+               status = nfsd4_encode_open_read_delegation4(xdr, open);
+               break;
+       case NFS4_OPEN_DELEGATE_WRITE:
+               /* write */
+               status = nfsd4_encode_open_write_delegation4(xdr, open);
+               break;
+       case NFS4_OPEN_DELEGATE_NONE_EXT:
+               /* od_whynone */
+               status = nfsd4_encode_open_none_delegation4(xdr, open);
+               break;
+       default:
+               status = nfserr_serverfault;
+       }
+
+       return status;
+}
+
 static __be32
 nfsd4_encode_open(struct nfsd4_compoundres *resp, __be32 nfserr,
                  union nfsd4_op_u *u)
 {
        struct nfsd4_open *open = &u->open;
        struct xdr_stream *xdr = resp->xdr;
-       __be32 *p;
 
        nfserr = nfsd4_encode_stateid4(xdr, &open->op_stateid);
        if (nfserr)
@@ -4196,28 +4226,8 @@ nfsd4_encode_open(struct nfsd4_compoundres *resp, __be32 nfserr,
        if (nfserr)
                return nfserr;
 
-       p = xdr_reserve_space(xdr, 4);
-       if (!p)
-               return nfserr_resource;
-
-       *p++ = cpu_to_be32(open->op_delegate_type);
-       switch (open->op_delegate_type) {
-       case NFS4_OPEN_DELEGATE_NONE:
-               break;
-       case NFS4_OPEN_DELEGATE_READ:
-               /* read */
-               return nfsd4_encode_open_read_delegation4(xdr, open);
-       case NFS4_OPEN_DELEGATE_WRITE:
-               /* write */
-               return nfsd4_encode_open_write_delegation4(xdr, open);
-       case NFS4_OPEN_DELEGATE_NONE_EXT:
-               /* od_whynone */
-               return nfsd4_encode_open_none_delegation4(xdr, open);
-       default:
-               BUG();
-       }
-       /* XXX save filehandle here */
-       return 0;
+       /* delegation */
+       return nfsd4_encode_open_delegation4(xdr, open);
 }
 
 static __be32