From c3c2bc80a6ff798467684f1805093d715c92e6b4 Mon Sep 17 00:00:00 2001
From: green <green>
Date: Wed, 19 Oct 2005 18:58:42 +0000
Subject: [PATCH] b=9482 r=adilger Check that there is no page_mapped() before
 trying to define it for 2.4 kernels.

---
 lustre/autoconf/lustre-core.m4         | 16 ++++++++++++++++
 lustre/include/linux/lustre_compat25.h |  2 ++
 2 files changed, 18 insertions(+)

diff --git a/lustre/autoconf/lustre-core.m4 b/lustre/autoconf/lustre-core.m4
index b77ce5f..5b48d1c 100644
--- a/lustre/autoconf/lustre-core.m4
+++ b/lustre/autoconf/lustre-core.m4
@@ -414,6 +414,21 @@ LB_LINUX_TRY_COMPILE([
 ])
 ])
 
+AC_DEFUN([LC_FUNC_PAGE_MAPPED],
+[AC_MSG_CHECKING([if kernel offers page_mapped])
+LB_LINUX_TRY_COMPILE([
+	#include <linux/mm.h>
+],[
+	page_mapped(NULL);
+],[
+	AC_MSG_RESULT([yes])
+	AC_DEFINE(HAVE_PAGE_MAPPED, 1, [page_mapped found])
+],[
+	AC_MSG_RESULT([no])
+])
+])
+
+
 #
 # LC_PROG_LINUX
 #
@@ -437,6 +452,7 @@ LC_FUNC_GRAB_CACHE_PAGE_NOWAIT_GFP
 LC_FUNC_DEV_SET_RDONLY
 LC_FUNC_FILEMAP_FDATAWRITE
 LC_STRUCT_STATFS
+LC_FUNC_PAGE_MAPPED
 ])
 
 #
diff --git a/lustre/include/linux/lustre_compat25.h b/lustre/include/linux/lustre_compat25.h
index 86430bf..e5260f1 100644
--- a/lustre/include/linux/lustre_compat25.h
+++ b/lustre/include/linux/lustre_compat25.h
@@ -287,6 +287,7 @@ static inline int mapping_mapped(struct address_space *mapping)
 #define ll_zap_page_range(vma, addr, len)  zap_page_range(vma->vm_mm, addr, len)
 #endif
 
+#ifndef HAVE_PAGE_MAPPED
 /* Poor man's page_mapped. substract from page count, counts from
    buffers/pagecache and our own count (we are supposed to hold one reference).
    What is left are user mappings and also others who work with this page now,
@@ -295,6 +296,7 @@ static inline int page_mapped(struct page *page)
 {
         return page_count(page) - !!page->mapping - !!page->buffers - 1;
 }
+#endif /* !HAVE_PAGE_MAPPED */
 
 #endif /* end of 2.4 compat macros */
 
-- 
1.8.3.1