b=16098

[fs/lustre-release.git] / lustre / llite / llite_mmap.c

diff --git a/lustre/llite/llite_mmap.c b/lustre/llite/llite_mmap.c
index 147a4d7..7866bf4 100644 (file)
--- a/lustre/llite/llite_mmap.c
+++ b/lustre/llite/llite_mmap.c
@@ -1,22 +1,37 @@
 /* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
  * vim:expandtab:shiftwidth=8:tabstop=8:
  *
- *  Copyright (c) 2001-2003 Cluster File Systems, Inc.
+ * GPL HEADER START
  *
- *   This file is part of Lustre, http://www.lustre.org.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
- *   Lustre is free software; you can redistribute it and/or
- *   modify it under the terms of version 2 of the GNU General Public
- *   License as published by the 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 version 2 only,
+ * as published by the Free Software Foundation.
  *
- *   Lustre 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.
+ * 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 version 2 for more details (a copy is included
+ * in the LICENSE file that accompanied this code).
  *
- *   You should have received a copy of the GNU General Public License
- *   along with Lustre; if not, write to the Free Software
- *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ * You should have received a copy of the GNU General Public License
+ * version 2 along with this program; If not, see [sun.com URL with a
+ * copy of GPLv2].
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ *
+ * GPL HEADER END
+ */
+/*
+ * Copyright  2008 Sun Microsystems, Inc. All rights reserved
+ * Use is subject to license terms.
+ */
+/*
+ * This file is part of Lustre, http://www.lustre.org/
+ * Lustre is a trademark of Sun Microsystems, Inc.
  */
 
 #ifndef AUTOCONF_INCLUDED
@@ -290,6 +305,11 @@ static struct vm_area_struct * our_vma(unsigned long addr, size_t count)
         RETURN(ret);
 }
 
+int ll_region_mapped(unsigned long addr, size_t count)
+{
+        return !!our_vma(addr, count);
+}
+
 int lt_get_mmap_locks(struct ll_lock_tree *tree,
                       unsigned long addr, size_t count)
 {
@@ -328,20 +348,16 @@ int lt_get_mmap_locks(struct ll_lock_tree *tree,
         RETURN(0);
 }
 
-/* FIXME: there is a pagefault race goes as follow (only 2.4):
- * 1. A user process on node A accesses a portion of a mapped file,
- *    resulting in a page fault.  The pagefault handler invokes the
- *    ll_nopage function, which reads the page into memory.
- * 2. A user process on node B writes to the same portion of the file
- *    (either via mmap or write()), that cause node A to cancel the
- *    lock and truncate the page.
- * 3. Node A then executes the rest of do_no_page(), entering the
- *    now-invalid page into the PTEs.
+/**
+ * Page fault handler.
  *
- * Make the whole do_no_page as a hook to cover both the page cache
- * and page mapping installing with dlm lock would eliminate this race.
+ * \param vma - is virtiual area struct related to page fault
+ * \param address - address when hit fault
+ * \param type - of fault
  *
- * In 2.6, the truncate_count of address_space can cover this race.
+ * \return allocated and filled page for address
+ * \retval NOPAGE_SIGBUS if page not exist on this address
+ * \retval NOPAGE_OOM not have memory for allocate new page
  */
 struct page *ll_nopage(struct vm_area_struct *vma, unsigned long address,
                        int *type)
@@ -442,8 +458,13 @@ struct page *ll_nopage(struct vm_area_struct *vma, unsigned long address,
         vma->vm_flags |= VM_RAND_READ;
 
         page = filemap_nopage(vma, address, type);
-        LL_CDEBUG_PAGE(D_PAGE, page, "got addr %lu type %lx\n", address,
-                       (long)type);
+        if (page != NOPAGE_SIGBUS && page != NOPAGE_OOM)
+                LL_CDEBUG_PAGE(D_PAGE, page, "got addr %lu type %lx\n", address,
+                               (long)type);
+        else
+                CDEBUG(D_PAGE, "got addr %lu type %lx - SIGBUS\n",  address,
+                               (long)type);
+
         vma->vm_flags &= ~VM_RAND_READ;
         vma->vm_flags |= (rand_read | seq_read);