NFSD: Clean up stale comments in nfsd_dispatch()

Add a documenting comment for the function. Remove comments that
simply describe obvious aspects of the code, but leave comments
that explain the differences in processing of each NFS version.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

fs/nfsd/nfssvc.c

@@ -1000,8 +1000,18 @@ static bool nfs_request_too_big(struct svc_rqst *rqstp,
 	return rqstp->rq_arg.len > PAGE_SIZE;
 }
 
-int
-nfsd_dispatch(struct svc_rqst *rqstp, __be32 *statp)
+/**
+ * nfsd_dispatch - Process an NFS or NFSACL Request
+ * @rqstp: incoming request
+ * @statp: pointer to location of accept_stat field in RPC Reply buffer
+ *
+ * This RPC dispatcher integrates the NFS server's duplicate reply cache.
+ *
+ * Return values:
+ *  %0: Processing complete; do not send a Reply
+ *  %1: Processing complete; send Reply in rqstp->rq_res
+ */
+int nfsd_dispatch(struct svc_rqst *rqstp, __be32 *statp)
 {
 	const struct svc_procedure *proc;
 	__be32			nfserr;
@@ -1021,14 +1031,12 @@ nfsd_dispatch(struct svc_rqst *rqstp, __be32 *statp)
 	 * (necessary in the NFSv4.0 compound case)
 	 */
 	rqstp->rq_cachetype = proc->pc_cachetype;
-	/* Decode arguments */
 	if (!proc->pc_decode(rqstp, (__be32 *)rqstp->rq_arg.head[0].iov_base)) {
 		dprintk("nfsd: failed to decode arguments!\n");
 		*statp = rpc_garbage_args;
 		return 1;
 	}
 
-	/* Check whether we have this call in the cache. */
 	switch (nfsd_cache_lookup(rqstp)) {
 	case RC_DOIT:
 		break;
@@ -1038,14 +1046,14 @@ nfsd_dispatch(struct svc_rqst *rqstp, __be32 *statp)
 		return 0;
 	}
 
-	/* need to grab the location to store the status, as
-	 * nfsv4 does some encoding while processing 
+	/*
+	 * Need to grab the location to store the status, as
+	 * NFSv4 does some encoding while processing
 	 */
 	nfserrp = rqstp->rq_res.head[0].iov_base
 		+ rqstp->rq_res.head[0].iov_len;
 	rqstp->rq_res.head[0].iov_len += sizeof(__be32);
 
-	/* Now call the procedure handler, and encode NFS status. */
 	nfserr = proc->pc_func(rqstp);
 	nfserr = map_new_errors(rqstp->rq_vers, nfserr);
 	if (nfserr == nfserr_dropit || test_bit(RQ_DROPME, &rqstp->rq_flags)) {
@@ -1057,12 +1065,11 @@ nfsd_dispatch(struct svc_rqst *rqstp, __be32 *statp)
 	if (rqstp->rq_proc != 0)
 		*nfserrp++ = nfserr;
 
-	/* Encode result.
+	/*
 	 * For NFSv2, additional info is never returned in case of an error.
 	 */
 	if (!(nfserr && rqstp->rq_vers == 2)) {
 		if (!proc->pc_encode(rqstp, nfserrp)) {
-			/* Failed to encode result. Release cache entry */
 			dprintk("nfsd: failed to encode result!\n");
 			nfsd_cache_update(rqstp, RC_NOCACHE, NULL);
 			*statp = rpc_system_err;
@@ -1070,7 +1077,6 @@ nfsd_dispatch(struct svc_rqst *rqstp, __be32 *statp)
 		}
 	}
 
-	/* Store reply in cache. */
 	nfsd_cache_update(rqstp, rqstp->rq_cachetype, statp + 1);
 	return 1;
 }