The function get_shadow_from_swap_cache() can race with swapoff, though
it's only called by do_swap_page() now.
Fixes: aae466b0052e ("mm/swap: implement workingset detection for anonymous LRU")
Signed-off-by: Miaohe Lin <linmiaohe@xxxxxxxxxx>
---
mm/swap_state.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)
diff --git a/mm/swap_state.c b/mm/swap_state.c
index 272ea2108c9d..709c260d644a 100644
--- a/mm/swap_state.c
+++ b/mm/swap_state.c
@@ -83,11 +83,14 @@ void show_swap_cache_info(void)
void *get_shadow_from_swap_cache(swp_entry_t entry)
{
- struct address_space *address_space = swap_address_space(entry);
- pgoff_t idx = swp_offset(entry);
+ struct swap_info_struct *si;
struct page *page;
- page = xa_load(&address_space->i_pages, idx);
+ si = get_swap_device(entry);
+ if (!si)
+ return NULL;
+ page = xa_load(&swap_address_space(entry)->i_pages, swp_offset(entry));
+ put_swap_device(si);
if (xa_is_value(page))
return page;
return NULL;
--
2.19.1
