[PATCH v2 1/9] userfaultfd/hugetlbfs: avoid including userfaultfd_k.h in hugetlb.h

[Axel Rasmussen <axelrasmussen@google.com>]

Minimizing header file inclusion is desirable. In this case, we can do
so just by forward declaring the enumeration our signature relies upon.

Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Axel Rasmussen <axelrasmussen@google.com>
---
 include/linux/hugetlb.h | 4 +++-
 mm/hugetlb.c            | 1 +
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index 09f1fd12a6fa..3f47650ab79b 100644
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -11,7 +11,6 @@
 #include <linux/kref.h>
 #include <linux/pgtable.h>
 #include <linux/gfp.h>
-#include <linux/userfaultfd_k.h>
 
 struct ctl_table;
 struct user_struct;
@@ -135,6 +134,8 @@ void hugetlb_show_meminfo(void);
 unsigned long hugetlb_total_pages(void);
 vm_fault_t hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma,
 			unsigned long address, unsigned int flags);
+
+enum mcopy_atomic_mode;
 #ifdef CONFIG_USERFAULTFD
 int hugetlb_mcopy_atomic_pte(struct mm_struct *dst_mm, pte_t *dst_pte,
 				struct vm_area_struct *dst_vma,
@@ -143,6 +144,7 @@ int hugetlb_mcopy_atomic_pte(struct mm_struct *dst_mm, pte_t *dst_pte,
 				enum mcopy_atomic_mode mode,
 				struct page **pagep);
 #endif /* CONFIG_USERFAULTFD */
+
 bool hugetlb_reserve_pages(struct inode *inode, long from, long to,
 						struct vm_area_struct *vma,
 						vm_flags_t vm_flags);
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 54d81d5947ed..b1652e747318 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -40,6 +40,7 @@
 #include <linux/hugetlb_cgroup.h>
 #include <linux/node.h>
 #include <linux/page_owner.h>
+#include <linux/userfaultfd_k.h>
 #include "internal.h"
 
 int hugetlb_max_hstate __read_mostly;
-- 
2.31.1.295.g9ea45b61b8-goog