From 4fd7715fbe33db933555a0ab122df9f178e0e3e4 Mon Sep 17 00:00:00 2001
From: James Simmons <uja.ornl@yahoo.com>
Date: Mon, 19 Jun 2017 12:36:04 -0400
Subject: [PATCH] LU-9558 llite: handle struct vm_operations changes

For the linux 4.11 kernel passing in struct vm_area_struct
to struct vm_operations members has been removed since
struct vm_area_struct has been merged into struct vm_fault.
Handle these changes in the llite layer.

Linux-commit: 11bac80004499ea59f361ef2a5516c84b6eab675

Change-Id: Ie44dd50de487044e3e2205978b7a36b15f7b0983
Signed-off-by: James Simmons <uja.ornl@yahoo.com>
---
 lustre/autoconf/lustre-core.m4 | 26 ++++++++++++++++++++++++++
 lustre/llite/llite_mmap.c      | 16 ++++++++++++++++
 lustre/llite/vvp_io.c          |  4 ++++
 3 files changed, 46 insertions(+)

diff --git a/lustre/autoconf/lustre-core.m4 b/lustre/autoconf/lustre-core.m4
index 89a64c5..f1ed50a 100644
--- a/lustre/autoconf/lustre-core.m4
+++ b/lustre/autoconf/lustre-core.m4
@@ -2492,6 +2492,29 @@ vm_fault_address, [
 ]) # LC_HAVE_VM_FAULT_ADDRESS
 
 #
+# LC_VM_OPERATIONS_REMOVE_VMF_ARG
+#
+# Kernel version 4.11 commit 11bac80004499ea59f361ef2a5516c84b6eab675
+# removed struct vm_area_struct as an argument for vm_operations since
+# in the same kernel version struct vma_area_struct was folded into
+# struct vm_fault.
+#
+AC_DEFUN([LC_VM_OPERATIONS_REMOVE_VMF_ARG], [
+LB_CHECK_COMPILE([if 'struct vm_operations' removed struct vm_area_struct],
+vm_operations_no_vm_area_struct, [
+	#include <linux/mm.h>
+],[
+	struct vm_fault vmf;
+
+	((struct vm_operations_struct *)0)->fault(&vmf);
+	((struct vm_operations_struct *)0)->page_mkwrite(&vmf);
+],[
+	AC_DEFINE(HAVE_VM_OPS_USE_VM_FAULT_ONLY, 1,
+		['struct vm_operations' remove struct vm_area_struct argument])
+])
+]) # LC_VM_OPERATIONS_REMOVE_VMF_ARG
+
+#
 # LC_PROG_LINUX
 #
 # Lustre linux kernel checks
@@ -2699,6 +2722,9 @@ AC_DEFUN([LC_PROG_LINUX], [
 	LC_IOP_GENERIC_READLINK
 	LC_HAVE_VM_FAULT_ADDRESS
 
+	# 4.11
+	LC_VM_OPERATIONS_REMOVE_VMF_ARG
+
 	#
 	AS_IF([test "x$enable_server" != xno], [
 		LC_STACK_SIZE
diff --git a/lustre/llite/llite_mmap.c b/lustre/llite/llite_mmap.c
index 6fc266c..2adbc52 100644
--- a/lustre/llite/llite_mmap.c
+++ b/lustre/llite/llite_mmap.c
@@ -283,7 +283,11 @@ static int ll_fault0(struct vm_area_struct *vma, struct vm_fault *vmf)
 	if (ll_sbi_has_fast_read(ll_i2sbi(file_inode(vma->vm_file)))) {
 		/* do fast fault */
 		ll_cl_add(vma->vm_file, env, NULL, LCC_MMAP);
+#ifdef	HAVE_VM_OPS_USE_VM_FAULT_ONLY
+		fault_ret = filemap_fault(vmf);
+#else
 		fault_ret = filemap_fault(vma, vmf);
+#endif
 		ll_cl_remove(vma->vm_file, env);
 
 		/* - If there is no error, then the page was found in cache and
@@ -342,8 +346,14 @@ out:
 	RETURN(fault_ret);
 }
 
+#ifdef HAVE_VM_OPS_USE_VM_FAULT_ONLY
+static int ll_fault(struct vm_fault *vmf)
+{
+	struct vm_area_struct *vma = vmf->vma;
+#else
 static int ll_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 {
+#endif
 	int count = 0;
 	bool printed = false;
 	int result;
@@ -385,8 +395,14 @@ restart:
         return result;
 }
 
+#ifdef HAVE_VM_OPS_USE_VM_FAULT_ONLY
+static int ll_page_mkwrite(struct vm_fault *vmf)
+{
+	struct vm_area_struct *vma = vmf->vma;
+#else
 static int ll_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
 {
+#endif
 	int count = 0;
 	bool printed = false;
 	bool retry;
diff --git a/lustre/llite/vvp_io.c b/lustre/llite/vvp_io.c
index c272256..a1fa7fe 100644
--- a/lustre/llite/vvp_io.c
+++ b/lustre/llite/vvp_io.c
@@ -1130,7 +1130,11 @@ static int vvp_io_kernel_fault(struct vvp_fault_io *cfio)
 {
 	struct vm_fault *vmf = cfio->ft_vmf;
 
+#ifdef HAVE_VM_OPS_USE_VM_FAULT_ONLY
+	cfio->ft_flags = filemap_fault(vmf);
+#else
 	cfio->ft_flags = filemap_fault(cfio->ft_vma, vmf);
+#endif
 	cfio->ft_flags_valid = 1;
 
 	if (vmf->page) {
-- 
1.8.3.1