nfsd4: complete enforcement of 4.1 op ordering

Enforce the rules about compound op ordering.

Motivated by implementing RECLAIM_COMPLETE, for which the client is
implicit in the current session, so it is important to ensure a
succesful SEQUENCE proceeds the RECLAIM_COMPLETE.

Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

2 files changed, 43 insertions, 14 deletions

diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
index 37514c469846..e147dbcb7ef7 100644
--- a/fs/nfsd/nfs4proc.c
+++ b/fs/nfsd/nfs4proc.c
@@ -968,20 +968,36 @@ static struct nfsd4_operation nfsd4_ops[];
 static const char *nfsd4_op_name(unsigned opnum);
 
 /*
- * Enforce NFSv4.1 COMPOUND ordering rules.
+ * Enforce NFSv4.1 COMPOUND ordering rules:
  *
- * TODO:
- * - enforce NFS4ERR_NOT_ONLY_OP,
- * - DESTROY_SESSION MUST be the final operation in the COMPOUND request.
+ * Also note, enforced elsewhere:
+ *      - SEQUENCE other than as first op results in
+ *        NFS4ERR_SEQUENCE_POS. (Enforced in nfsd4_sequence().)
+ *      - BIND_CONN_TO_SESSION must be the only op in its compound
+ *        (Will be enforced in nfsd4_bind_conn_to_session().)
+ *      - DESTROY_SESSION must be the final operation in a compound, if
+ *        sessionid's in SEQUENCE and DESTROY_SESSION are the same.
+ *        (Enforced in nfsd4_destroy_session().)
  */
-static bool nfs41_op_ordering_ok(struct nfsd4_compoundargs *args)
+static __be32 nfs41_check_op_ordering(struct nfsd4_compoundargs *args)
 {
-        if (args->minorversion && args->opcnt > 0) {
-                struct nfsd4_op *op = &args->ops[0];
-                return (op->status == nfserr_op_illegal) ||
-                       (nfsd4_ops[op->opnum].op_flags & ALLOWED_AS_FIRST_OP);
-        }
-        return true;
+        struct nfsd4_op *op = &args->ops[0];
+
+        /* These ordering requirements don't apply to NFSv4.0: */
+        if (args->minorversion == 0)
+                return nfs_ok;
+        /* This is weird, but OK, not our problem: */
+        if (args->opcnt == 0)
+                return nfs_ok;
+        if (op->status == nfserr_op_illegal)
+                return nfs_ok;
+        if (!(nfsd4_ops[op->opnum].op_flags & ALLOWED_AS_FIRST_OP))
+                return nfserr_op_not_in_session;
+        if (op->opnum == OP_SEQUENCE)
+                return nfs_ok;
+        if (args->opcnt != 1)
+                return nfserr_not_only_op;
+        return nfs_ok;
 }
 
 /*
@@ -1023,13 +1039,13 @@ nfsd4_proc_compound(struct svc_rqst *rqstp,
         if (args->minorversion > nfsd_supported_minorversion)
                 goto out;
 
-        if (!nfs41_op_ordering_ok(args)) {
+        status = nfs41_check_op_ordering(args);
+        if (status) {
                 op = &args->ops[0];
-                op->status = nfserr_sequence_pos;
+                op->status = status;
                 goto encode_op;
         }
 
-        status = nfs_ok;
         while (!status && resp->opcnt < args->opcnt) {
                 op = &args->ops[resp->opcnt++];
 
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 4300d9ffe95f..bba9fff49cfe 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -1343,6 +1343,14 @@ out:
         return status;
 }
 
+static bool nfsd4_last_compound_op(struct svc_rqst *rqstp)
+{
+        struct nfsd4_compoundres *resp = rqstp->rq_resp;
+        struct nfsd4_compoundargs *argp = rqstp->rq_argp;
+
+        return argp->opcnt == resp->opcnt;
+}
+
 __be32
 nfsd4_destroy_session(struct svc_rqst *r,
                       struct nfsd4_compound_state *cstate,
@@ -1358,6 +1366,11 @@ nfsd4_destroy_session(struct svc_rqst *r,
          * - Do we need to clear any callback info from previous session?
          */
 
+        if (!memcmp(&sessionid->sessionid, &cstate->session->se_sessionid,
+                                        sizeof(struct nfs4_sessionid))) {
+                if (!nfsd4_last_compound_op(r))
+                        return nfserr_not_only_op;
+        }
         dump_sessionid(__func__, &sessionid->sessionid);
         spin_lock(&sessionid_lock);
         ses = find_in_sessionid_hashtbl(&sessionid->sessionid);