NFSD: Add a helper that encodes NFSv3 directory offset cookies

Refactor: De-duplicate identical code that handles encoding of
directory offset cookies across page boundaries.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

fs/nfsd/nfs3proc.c

@@ -495,17 +495,7 @@ nfsd3_proc_readdir(struct svc_rqst *rqstp)
 		count += PAGE_SIZE;
 	}
 	resp->count = count >> 2;
-	if (resp->offset) {
-		if (unlikely(resp->offset1)) {
-			/* we ended up with offset on a page boundary */
-			*resp->offset = htonl(offset >> 32);
-			*resp->offset1 = htonl(offset & 0xffffffff);
-			resp->offset1 = NULL;
-		} else {
-			xdr_encode_hyper(resp->offset, offset);
-		}
-		resp->offset = NULL;
-	}
+	nfs3svc_encode_cookie3(resp, offset);
 
 	return rpc_success;
 }
@@ -560,17 +550,7 @@ nfsd3_proc_readdirplus(struct svc_rqst *rqstp)
 		count += PAGE_SIZE;
 	}
 	resp->count = count >> 2;
-	if (resp->offset) {
-		if (unlikely(resp->offset1)) {
-			/* we ended up with offset on a page boundary */
-			*resp->offset = htonl(offset >> 32);
-			*resp->offset1 = htonl(offset & 0xffffffff);
-			resp->offset1 = NULL;
-		} else {
-			xdr_encode_hyper(resp->offset, offset);
-		}
-		resp->offset = NULL;
-	}
+	nfs3svc_encode_cookie3(resp, offset);
 
 out:
 	return rpc_success;

fs/nfsd/nfs3xdr.c

@@ -1219,6 +1219,28 @@ static __be32 *encode_entryplus_baggage(struct nfsd3_readdirres *cd, __be32 *p,
 	return p;
 }
 
+/**
+ * nfs3svc_encode_cookie3 - Encode a directory offset cookie
+ * @resp: readdir result context
+ * @offset: offset cookie to encode
+ *
+ */
+void nfs3svc_encode_cookie3(struct nfsd3_readdirres *resp, u64 offset)
+{
+	if (!resp->offset)
+		return;
+
+	if (resp->offset1) {
+		/* we ended up with offset on a page boundary */
+		*resp->offset = cpu_to_be32(offset >> 32);
+		*resp->offset1 = cpu_to_be32(offset & 0xffffffff);
+		resp->offset1 = NULL;
+	} else {
+		xdr_encode_hyper(resp->offset, offset);
+	}
+	resp->offset = NULL;
+}
+
 /*
  * Encode a directory entry. This one works for both normal readdir
  * and readdirplus.
@@ -1244,19 +1266,7 @@ encode_entry(struct readdir_cd *ccd, const char *name, int namlen,
 	int		elen;		/* estimated entry length in words */
 	int		num_entry_words = 0;	/* actual number of words */
 
-	if (cd->offset) {
-		u64 offset64 = offset;
-
-		if (unlikely(cd->offset1)) {
-			/* we ended up with offset on a page boundary */
-			*cd->offset = htonl(offset64 >> 32);
-			*cd->offset1 = htonl(offset64 & 0xffffffff);
-			cd->offset1 = NULL;
-		} else {
-			xdr_encode_hyper(cd->offset, offset64);
-		}
-		cd->offset = NULL;
-	}
+	nfs3svc_encode_cookie3(cd, offset);
 
 	/*
 	dprintk("encode_entry(%.*s @%ld%s)\n",

fs/nfsd/xdr3.h

@@ -300,6 +300,8 @@ int nfs3svc_encode_commitres(struct svc_rqst *, __be32 *);
 
 void nfs3svc_release_fhandle(struct svc_rqst *);
 void nfs3svc_release_fhandle2(struct svc_rqst *);
+
+void nfs3svc_encode_cookie3(struct nfsd3_readdirres *resp, u64 offset);
 int nfs3svc_encode_entry(void *, const char *name,
 				int namlen, loff_t offset, u64 ino,
 				unsigned int);