nfs41: consider minorversion in callback_xdr:process_op

Note that this patch changes the nfsv4.0 behavior also when
CONFIG_NFS_V4_1 is not defined where NFS4ERR_MINOR_VERS_MISMATCH
will be returned if the client received a CB_COMPOUND
with minorversion != 0.  Previously, it would have
returned NFS4ERR_OP_ILLEGAL for CB_SEQUENCE.
(or if the server is broken and sent OP_CB_GETATTR or OP_CB_RECALL
with minorversion!=0, they would have been processed normally.

Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[nfs41: refactor op preprocessing out of process_op]
See http://linux-nfs.org/pipermail/pnfs/2009-June/007845.html
[nfs41: define CB_NOTIFY_DEVICEID as not supported]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>

1 files changed, 71 insertions, 14 deletions

diff --git a/fs/nfs/callback_xdr.c b/fs/nfs/callback_xdr.c
index f6cc79b1d1f3..41c5be1c1be5 100644
--- a/fs/nfs/callback_xdr.c
+++ b/fs/nfs/callback_xdr.c
@@ -356,31 +356,87 @@ out:
         return status;
 }
 
-static __be32 process_op(struct svc_rqst *rqstp,
+#if defined(CONFIG_NFS_V4_1)
+
+static __be32
+preprocess_nfs41_op(int nop, unsigned int op_nr, struct callback_op **op)
+{
+        switch (op_nr) {
+        case OP_CB_GETATTR:
+        case OP_CB_RECALL:
+                *op = &callback_ops[op_nr];
+                break;
+
+        case OP_CB_LAYOUTRECALL:
+        case OP_CB_NOTIFY_DEVICEID:
+        case OP_CB_NOTIFY:
+        case OP_CB_PUSH_DELEG:
+        case OP_CB_RECALL_ANY:
+        case OP_CB_RECALLABLE_OBJ_AVAIL:
+        case OP_CB_RECALL_SLOT:
+        case OP_CB_SEQUENCE:
+        case OP_CB_WANTS_CANCELLED:
+        case OP_CB_NOTIFY_LOCK:
+                return htonl(NFS4ERR_NOTSUPP);
+
+        default:
+                return htonl(NFS4ERR_OP_ILLEGAL);
+        }
+
+        return htonl(NFS_OK);
+}
+
+#else /* CONFIG_NFS_V4_1 */
+
+static __be32
+preprocess_nfs41_op(int nop, unsigned int op_nr, struct callback_op **op)
+{
+        return htonl(NFS4ERR_MINOR_VERS_MISMATCH);
+}
+
+#endif /* CONFIG_NFS_V4_1 */
+
+static __be32
+preprocess_nfs4_op(unsigned int op_nr, struct callback_op **op)
+{
+        switch (op_nr) {
+        case OP_CB_GETATTR:
+        case OP_CB_RECALL:
+                *op = &callback_ops[op_nr];
+                break;
+        default:
+                return htonl(NFS4ERR_OP_ILLEGAL);
+        }
+
+        return htonl(NFS_OK);
+}
+
+static __be32 process_op(uint32_t minorversion, int nop,
+                struct svc_rqst *rqstp,
                 struct xdr_stream *xdr_in, void *argp,
                 struct xdr_stream *xdr_out, void *resp)
 {
         struct callback_op *op = &callback_ops[0];
         unsigned int op_nr = OP_CB_ILLEGAL;
-        __be32 status = 0;
+        __be32 status;
         long maxlen;
         __be32 res;
 
         dprintk("%s: start\n", __func__);
         status = decode_op_hdr(xdr_in, &op_nr);
-        if (likely(status == 0)) {
-                switch (op_nr) {
-                        case OP_CB_GETATTR:
-                        case OP_CB_RECALL:
-                                op = &callback_ops[op_nr];
-                                break;
-                        default:
-                                op_nr = OP_CB_ILLEGAL;
-                                op = &callback_ops[0];
-                                status = htonl(NFS4ERR_OP_ILLEGAL);
-                }
+        if (unlikely(status)) {
+                status = htonl(NFS4ERR_OP_ILLEGAL);
+                goto out;
         }
 
+        dprintk("%s: minorversion=%d nop=%d op_nr=%u\n",
+                __func__, minorversion, nop, op_nr);
+
+        status = minorversion ? preprocess_nfs41_op(nop, op_nr, &op) :
+                                preprocess_nfs4_op(op_nr, &op);
+        if (status == htonl(NFS4ERR_OP_ILLEGAL))
+                op_nr = OP_CB_ILLEGAL;
+out:
         maxlen = xdr_out->end - xdr_out->p;
         if (maxlen > 0 && maxlen < PAGE_SIZE) {
                 if (likely(status == 0 && op->decode_args != NULL))
@@ -428,7 +484,8 @@ static __be32 nfs4_callback_compound(struct svc_rqst *rqstp, void *argp, void *r
                 return rpc_system_err;
 
         while (status == 0 && nops != hdr_arg.nops) {
-                status = process_op(rqstp, &xdr_in, argp, &xdr_out, resp);
+                status = process_op(hdr_arg.minorversion, nops,
+                                    rqstp, &xdr_in, argp, &xdr_out, resp);
                 nops++;
         }