[PATCH -next v4 2/6] Revert "mm: mark swap_lock and swap_active_head static"

[Liu Shixin <liushixin2@huawei.com>]

This reverts commit 633423a09cb5cfe61438283e1ce49c23cf4a0611.

swap_lock and swap_active_head will be used in next patch, so export it
again.

Signed-off-by: Liu Shixin <liushixin2@huawei.com>
---
 include/linux/swapfile.h | 2 ++
 mm/swapfile.c            | 4 ++--
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/include/linux/swapfile.h b/include/linux/swapfile.h
index 2fbcc9afd814..75fc069594a5 100644
--- a/include/linux/swapfile.h
+++ b/include/linux/swapfile.h
@@ -6,6 +6,8 @@
  * these were static in swapfile.c but frontswap.c needs them and we don't
  * want to expose them to the dozens of source files that include swap.h
  */
+extern spinlock_t swap_lock;
+extern struct plist_head swap_active_head;
 extern struct swap_info_struct *swap_info[];
 extern unsigned long generic_max_swapfile_size(void);
 /* Maximum swapfile size supported for the arch (not inclusive). */
diff --git a/mm/swapfile.c b/mm/swapfile.c
index 469d9af86be2..d383b282f269 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -51,7 +51,7 @@ static bool swap_count_continued(struct swap_info_struct *, pgoff_t,
 				 unsigned char);
 static void free_swap_count_continuations(struct swap_info_struct *);
 
-static DEFINE_SPINLOCK(swap_lock);
+DEFINE_SPINLOCK(swap_lock);
 static unsigned int nr_swapfiles;
 atomic_long_t nr_swap_pages;
 /*
@@ -77,7 +77,7 @@ static const char Unused_offset[] = "Unused swap offset entry ";
  * all active swap_info_structs
  * protected with swap_lock, and ordered by priority.
  */
-static PLIST_HEAD(swap_active_head);
+PLIST_HEAD(swap_active_head);
 
 /*
  * all available (active, not full) swap_info_structs
-- 
2.25.1