NFS: readdir shouldn't read beyond the reply returned by the server

Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

fs/nfs/dir.c

@@ -573,11 +573,13 @@ int nfs_readdir_xdr_to_array(nfs_readdir_descriptor_t *desc, struct page *page,
 	if (!pages_ptr)
 		goto out_release_array;
 	do {
+		unsigned int pglen;
 		status = nfs_readdir_xdr_filler(pages, desc, &entry, file, inode);
 
 		if (status < 0)
 			break;
-		status = nfs_readdir_page_filler(desc, &entry, pages_ptr, page, array_size * PAGE_SIZE);
+		pglen = status;
+		status = nfs_readdir_page_filler(desc, &entry, pages_ptr, page, pglen);
 		if (status < 0) {
 			if (status == -ENOSPC)
 				status = 0;

fs/nfs/nfs2xdr.c

@@ -423,7 +423,7 @@ nfs_xdr_readdirres(struct rpc_rqst *req, __be32 *p, void *dummy)
 	struct page **page;
 	size_t hdrlen;
 	unsigned int pglen, recvd;
-	int status, nr = 0;
+	int status;
 
 	if ((status = ntohl(*p++)))
 		return nfs_stat_to_errno(status);
@@ -443,7 +443,7 @@ nfs_xdr_readdirres(struct rpc_rqst *req, __be32 *p, void *dummy)
 	if (pglen > recvd)
 		pglen = recvd;
 	page = rcvbuf->pages;
-	return nr;
+	return pglen;
 }
 
 static void print_overflow_msg(const char *func, const struct xdr_stream *xdr)

fs/nfs/nfs3xdr.c

@@ -555,7 +555,7 @@ nfs3_xdr_readdirres(struct rpc_rqst *req, __be32 *p, struct nfs3_readdirres *res
 	struct page **page;
 	size_t hdrlen;
 	u32 recvd, pglen;
-	int status, nr = 0;
+	int status;
 
 	status = ntohl(*p++);
 	/* Decode post_op_attrs */
@@ -586,7 +586,7 @@ nfs3_xdr_readdirres(struct rpc_rqst *req, __be32 *p, struct nfs3_readdirres *res
 		pglen = recvd;
 	page = rcvbuf->pages;
 
-	return nr;
+	return pglen;
 }
 
 __be32 *

fs/nfs/nfs4proc.c

@@ -2852,8 +2852,10 @@ static int _nfs4_proc_readdir(struct dentry *dentry, struct rpc_cred *cred,
 	nfs4_setup_readdir(cookie, NFS_COOKIEVERF(dir), dentry, &args);
 	res.pgbase = args.pgbase;
 	status = nfs4_call_sync(NFS_SERVER(dir), &msg, &args, &res, 0);
-	if (status == 0)
+	if (status >= 0) {
 		memcpy(NFS_COOKIEVERF(dir), res.verifier.data, NFS4_VERIFIER_SIZE);
+		status += args.pgbase;
+	}
 
 	nfs_invalidate_atime(dir);
 

fs/nfs/nfs4xdr.c

@@ -4518,7 +4518,7 @@ static int decode_readdir(struct xdr_stream *xdr, struct rpc_rqst *req, struct n
 	xdr_read_pages(xdr, pglen);
 
 
-	return 0;
+	return pglen;
 }
 
 static int decode_readlink(struct xdr_stream *xdr, struct rpc_rqst *req)