From c761f248397334400f8b4bb71cc4d01d3e4fc6ff Mon Sep 17 00:00:00 2001
From: Derrick Brashear <shadow@dementia.org>
Date: Tue, 20 May 2008 22:02:49 +0000
Subject: [PATCH] linux-hlist-unhashed-opencoding-20080520

LICENSE IPL10
FIXES 93871

if we can't use hlist_unhashed (which is dumb) or we don't have it (less dumb) work around it.

====================
This delta was composed from multiple commits as part of the CVS->Git migration.
The checkin message with each commit was inconsistent.
The following are the additional commit messages.
====================
LICENSE IPL10
FIXES 93871

if we can't use hlist_unhashed (which is dumb) or we don't have it (less dumb) w
ork around it.
---
 acinclude.m4                 |  4 ++++
 src/afs/LINUX/osi_vnodeops.c | 10 +++++++++-
 src/cf/linux-test4.m4        | 12 ++++++++++++
 3 files changed, 25 insertions(+), 1 deletion(-)

diff --git a/acinclude.m4 b/acinclude.m4
index 8d54456ca5..ed5f9a9f35 100644
--- a/acinclude.m4
+++ b/acinclude.m4
@@ -645,6 +645,7 @@ case $AFS_SYSNAME in *_linux* | *_umlinux*)
 		 LINUX_KERNEL_SELINUX
 		 LINUX_KERNEL_SOCK_CREATE
 		 LINUX_KERNEL_PAGE_FOLLOW_LINK
+		 LINUX_KERNEL_HLIST_UNHASHED
                  LINUX_KEY_TYPE_H_EXISTS
 		 LINUX_NEED_RHCONFIG
 		 LINUX_RECALC_SIGPENDING_ARG_TYPE
@@ -823,6 +824,9 @@ case $AFS_SYSNAME in *_linux* | *_umlinux*)
 		 if test "x$ac_cv_linux_kernel_page_follow_link" = "xyes" ; then
 		  AC_DEFINE(HAVE_KERNEL_PAGE_FOLLOW_LINK, 1, [define if your linux kernel provides page_follow_link])
 		 fi
+		 if test "x$ac_cv_linux_kernel_page_follow_link" = "xyes" ; then
+		  AC_DEFINE(HAVE_KERNEL_HLIST_UNHASHED, 1, [define if your linux kernel provides hlist_unhashed])
+		 fi
 		 if test "x$ac_linux_syscall" = "xyes" ; then
 		  AC_DEFINE(HAVE_KERNEL_LINUX_SYSCALL_H, 1, [define if your linux kernel has linux/syscall.h])
 		 fi
diff --git a/src/afs/LINUX/osi_vnodeops.c b/src/afs/LINUX/osi_vnodeops.c
index 6a324c880a..94b386c23c 100644
--- a/src/afs/LINUX/osi_vnodeops.c
+++ b/src/afs/LINUX/osi_vnodeops.c
@@ -1033,7 +1033,15 @@ afs_linux_lookup(struct inode *dip, struct dentry *dp)
 	ip = AFSTOV(vcp);
 	afs_getattr(vcp, &vattr, credp);
 	afs_fill_inode(ip, &vattr);
-	if (hlist_unhashed(&ip->i_hash))
+	if (
+#ifdef HAVE_KERNEL_HLIST_UNHASHED
+	    hlist_unhashed(&ip->i_hash)
+#elif defined(AFS_LINUX26_ENV)
+	    ip->i_hash.pprev == NULL
+#else
+	    ip->i_hash.prev == NULL
+#endif
+	    )
 	    insert_inode_hash(ip);
     }
     dp->d_op = &afs_dentry_operations;
diff --git a/src/cf/linux-test4.m4 b/src/cf/linux-test4.m4
index 448d55143b..f14d5f8e76 100644
--- a/src/cf/linux-test4.m4
+++ b/src/cf/linux-test4.m4
@@ -511,6 +511,18 @@ AC_DEFUN([LINUX_KERNEL_PAGE_FOLLOW_LINK], [
     CPPFLAGS="$save_CPPFLAGS"])
   AC_MSG_RESULT($ac_cv_linux_kernel_page_follow_link)])
 
+AC_DEFUN([LINUX_KERNEL_HLIST_UNHASHED], [
+  AC_MSG_CHECKING([for hlist_unhashed])
+  AC_CACHE_VAL([ac_cv_linux_kernel_hlist_unhashed], [
+    save_CPPFLAGS="$CPPFLAGS"
+    CPPFLAGS="$CPPFLAGS -Werror-implicit-function-declaration"
+    AC_TRY_KBUILD(
+[#include <linux/list.h>],
+[hlist_unhashed(0);],
+      ac_cv_linux_kernel_hlist_unhashed=yes,
+      ac_cv_linux_kernel_hlist_unhashed=no)
+    CPPFLAGS="$save_CPPFLAGS"])
+  AC_MSG_RESULT($ac_cv_linux_kernel_hlist_unhashed)])
 
 AC_DEFUN([LINUX_FS_STRUCT_ADDRESS_SPACE_HAS_GFP_MASK], [
   AC_MSG_CHECKING([for gfp_mask in struct address_space])