1 files changed, 70 insertions, 0 deletions
diff --git a/libdiskfs/diskfs-pager.h b/libdiskfs/diskfs-pager.h
new file mode 100644
index 00000000..4ec0b27b
--- /dev/null
+++ b/libdiskfs/diskfs-pager.h
@@ -0,0 +1,70 @@
+/* Map the disk image and handle faults accessing it.
+   Copyright (C) 1996, 1997 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>
+
+/* Start a pager for the whole disk, and store it in DISKFS_DISK_PAGER,
+   preparing a signal preemptor so that the `diskfs_catch_exception' macro
+   below works.  SIZE should be the size of the image to map, and the address
+   mapped is returned in IMAGE.  INFO, PAGER_BUCKET, & MAY_CACHE are passed
+   to `pager_create'.  */
+extern void diskfs_start_disk_pager (struct user_pager_info *info,
+				     struct port_bucket *pager_bucket, int may_cache,
+				     size_t size, void **image);
+
+extern struct pager *diskfs_disk_pager;
+
+struct disk_image_user
+  {
+    jmp_buf env;
+    struct disk_image_user *next;
+  };
+
+/* 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()					      \
+({									      \
+    struct disk_image_user *diu = alloca (sizeof *diu);			      \
+    error_t err;							      \
+    diu->next = (void *) cthread_data (cthread_self ());		      \
+    err = setjmp (diu->env);						      \
+    if (err == 0)							      \
+      cthread_set_data (cthread_self (), diu);				      \
+    err;								      \
+})
+
+/* No longer handle faults on `disk_image' in this thread.
+   Any unexpected fault hereafter will crash the program.  */
+#define diskfs_end_catch_exception()					      \
+({									      \
+    struct disk_image_user *diu = (void *) cthread_data (cthread_self ());    \
+    cthread_set_data (cthread_self (), diu->next);			      \
+})
+
+
+#endif	/* hurd/diskfs-pager.h */