1 files changed, 77 insertions, 0 deletions
diff --git a/libstore/map.c b/libstore/map.c
new file mode 100644
index 00000000..4ac8ce98
--- /dev/null
+++ b/libstore/map.c
@@ -0,0 +1,77 @@
+/* Direct store mapping
+
+   Copyright (C) 1997 Free Software Foundation, Inc.
+   Written by Miles Bader <miles@gnu.ai.mit.edu>
+   This task is part of the GNU Hurd.
+
+   The GNU Hurd 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.
+
+   The GNU Hurd 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., 59 Temple Place - Suite 330, Boston, MA 02111, USA. */
+
+#include <hurd.h>
+#include <hurd/io.h>
+
+#include "store.h"
+
+/* Return a memory object paging on STORE.  [among other reasons,] this may
+   fail because store contains non-contiguous regions on the underlying
+   object.  In such a case you can try calling some of the routines below to
+   get a pager.  */
+error_t store_map (const struct store *store, vm_prot_t prot,
+		   mach_port_t *memobj)
+{
+  error_t (*map) (const struct store *store, vm_prot_t prot,
+		  mach_port_t *memobj) =
+    store->class->map;
+  error_t err = map ? (*map) (store, prot, memobj) : EOPNOTSUPP;
+
+  if (err == EOPNOTSUPP && store->source != MACH_PORT_NULL)
+    /* Can't map the store directly, but we know it represents the file
+       STORE->source, so we can try mapping that instead.  */
+    {
+      mach_port_t rd_memobj, wr_memobj;
+      int ro = (store->flags & STORE_HARD_READONLY);
+
+      if ((prot & VM_PROT_WRITE) && ro)
+	return EACCES;
+
+      err = io_map (store->port, &rd_memobj, &wr_memobj);
+      if (! err)
+	{
+	  *memobj = rd_memobj;
+
+	  if (!ro || wr_memobj != MACH_PORT_NULL)
+	    /* If either we or the server think this object is writable, then
+	       the write-memory-object must be the same as the read one (if
+	       we only care about reading, then it can be null too).  */
+	    {
+	      if (rd_memobj == wr_memobj)
+		{
+		  if (rd_memobj != MACH_PORT_NULL)
+		    mach_port_mod_refs (mach_task_self (), rd_memobj,
+					MACH_PORT_RIGHT_SEND, -1);
+		}
+	      else
+		{
+		  if (rd_memobj != MACH_PORT_NULL)
+		    mach_port_deallocate (mach_task_self (), rd_memobj);
+		  if (wr_memobj != MACH_PORT_NULL)
+		    mach_port_deallocate (mach_task_self (), wr_memobj);
+		  err = EOPNOTSUPP;
+		}
+	    }
+	}
+    }
+
+  return err;
+}