[PATCH 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.

Signed-off-by: Axel Rasmussen <axelrasmussen@google.com>
---
 include/linux/hugetlb.h | 5 ++++-
 mm/hugetlb.c            | 1 +
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index 1d3246b31a41..dfb749eaf348 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;
@@ -136,6 +135,8 @@ 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);
 #ifdef CONFIG_USERFAULTFD
+enum mcopy_atomic_mode;
+
 int hugetlb_mcopy_atomic_pte(struct mm_struct *dst_mm, pte_t *dst_pte,
 				struct vm_area_struct *dst_vma,
 				unsigned long dst_addr,
@@ -315,6 +316,8 @@ static inline void hugetlb_free_pgd_range(struct mmu_gather *tlb,
 }
 
 #ifdef CONFIG_USERFAULTFD
+enum mcopy_atomic_mode;
+
 static inline int hugetlb_mcopy_atomic_pte(struct mm_struct *dst_mm,
 						pte_t *dst_pte,
 						struct vm_area_struct *dst_vma,
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 9973dec4976c..3b93bbf8c80f 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