1 files changed, 62 insertions, 0 deletions
diff --git a/libdiskfs/diskfs-pager.h b/libdiskfs/diskfs-pager.h
new file mode 100644
index 00000000..7b2463b3
--- /dev/null
+++ b/libdiskfs/diskfs-pager.h
@@ -0,0 +1,62 @@
+/* Map the disk image and handle faults accessing it.
+   Copyright (C) 1996 Free Software Foundation, Inc.
+   Written by Roland McGrath.
+
+   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. */
+
+#ifndef _HURD_DISKFS_PAGER_H
+#define _HURD_DISKFS_PAGER_H 1
+#include <hurd/pager.h>
+#include <hurd/ports.h>
+#include <setjmp.h>
+#include <cthreads.h>
+#include <errno.h>
+#include <assert.h>
+#include <stdlib.h>
+
+
+/* Set up the three variables below and prepare a signal preempter
+   so that the `diskfs_catch_exception' macro below works.
+   INFO and MAY_CACHE are passed to `pager_create'.  */
+extern void disk_pager_setup (struct user_pager_info *info, int may_cache);
+
+extern struct port_bucket *pager_bucket; /* Ports bucket used by pagers.  */
+extern struct pager *disk_pager; /* Pager backing to the disk.  */
+extern void *disk_image;	/* Region mapping entire disk from it.  */
+
+/* Return zero now.  Return a second time with a nonzero error_t
+   if this thread faults accessing `disk_image' before calling
+   `diskfs_end_catch_exception' (below).  */
+#define diskfs_catch_exception()					      \
+({									      \
+    jmp_buf *env = alloca (sizeof (jmp_buf));				      \
+    error_t err;							      \
+    assert (cthread_data (cthread_self ()) == 0);			      \
+    err = setjmp (*env);						      \
+    if (err == 0)							      \
+      cthread_set_data (cthread_self (), env);				      \
+    err;								      \
+})
+
+/* No longer handle faults on `disk_image' in this thread.
+   Any unexpected fault hereafter will crash the program.  */
+#define diskfs_end_catch_exception()					      \
+({									      \
+    assert (cthread_data () != 0);					      \
+    cthread_set_data (cthread_self (), 0);				      \
+})
+
+
+#endif	/* hurd/diskfs-pager.h */