1 files changed, 46 insertions, 0 deletions
diff --git a/libdiskfs/io-readable.c b/libdiskfs/io-readable.c
new file mode 100644
index 00000000..ccc241ef
--- /dev/null
+++ b/libdiskfs/io-readable.c
@@ -0,0 +1,46 @@
+/* 
+   Copyright (C) 1994, 1995, 1996 Free Software Foundation
+
+   This program is free software; you can redistribute it and/or
+   modify it under the terms of the GNU General Public License as
+   published by the Free Software Foundation; either version 2, or (at
+   your option) any later version.
+
+   This program is distributed in the hope that it will be useful, but
+   WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
+
+#include "priv.h"
+#include "io_S.h"
+#include <fcntl.h>
+
+/* Implement io_readable as described in <hurd/io.defs>. */
+kern_return_t
+diskfs_S_io_readable (struct protid *cred,
+		      mach_msg_type_number_t *amount)
+{
+  struct node *np;
+
+  if (!cred)
+    return EOPNOTSUPP;
+  
+  if (!(cred->po->openstat & O_READ))
+    return EINVAL;
+
+  np = cred->po->np;
+  
+  mutex_lock (&np->lock);
+  iohelp_get_conch (&np->conch);
+  if (np->dn_stat.st_size > cred->po->filepointer)
+    *amount = np->dn_stat.st_size - cred->po->filepointer;
+  else
+    *amount = 0;
+
+  mutex_unlock (&np->lock);
+  return 0;
+}