1 files changed, 46 insertions, 0 deletions
diff --git a/libpager/pagemap.c b/libpager/pagemap.c
new file mode 100644
index 00000000..c6d924c7
--- /dev/null
+++ b/libpager/pagemap.c
@@ -0,0 +1,46 @@
+/* Pagemap manipulation for pager library
+   Copyright (C) 1994, 1997, 1999 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 <string.h>
+  
+/* Grow the pagemap of pager P as necessary to deal with address OFF */
+error_t
+_pager_pagemap_resize (struct pager *p, vm_address_t off)
+{
+  error_t err = 0;
+  
+  off /= __vm_page_size;
+
+  if (p->pagemapsize < off)
+    {
+      void *newaddr;
+      int newsize = round_page (off);
+
+      newaddr = mmap (0, newsize, PROT_READ|PROT_WRITE, MAP_ANON, 0, 0);
+      err = (newaddr == (void *) -1) ? errno : 0;
+      if (! err)
+	{
+	  bcopy (p->pagemap, newaddr, p->pagemapsize);
+	  munmap (p->pagemap, p->pagemapsize);
+	  p->pagemap = newaddr;
+	  p->pagemapsize = newsize;
+	}
+    }
+
+  return err;
+}