[PATCH] mm: fix swap offset when replacing shmem page
We used to have a single swap address space with swp_entry_t.val
as its radix tree index. This is not the case anymore. Now Each
swp_type() has its own address space and should use swp_offset()
as radix tree index.
Signed-off-by: Yu Zhao
---
mm/shmem.c | 11 +++
1 file changed, 7 insertions(+), 4 deletions(-)
diff --git a/mm/shmem.c b/mm/shmem.c
index d44991ea5ed4..a92c6ae26915 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -1509,11 +1509,13 @@ static int shmem_replace_page(struct page **pagep,
gfp_t gfp,
{
struct page *oldpage, *newpage;
struct address_space *swap_mapping;
- pgoff_t swap_index;
+ swp_entry_t entry;
int error;
+ VM_BUG_ON(PageSwapCache(*pagep));
+
oldpage = *pagep;
- swap_index = page_private(oldpage);
+ entry.val = page_private(oldpage);
swap_mapping = page_mapping(oldpage);
/*
@@ -1532,7 +1534,7 @@ static int shmem_replace_page(struct page **pagep, gfp_t
gfp,
__SetPageLocked(newpage);
__SetPageSwapBacked(newpage);
SetPageUptodate(newpage);
- set_page_private(newpage, swap_index);
+ set_page_private(newpage, entry.val);
SetPageSwapCache(newpage);
/*
@@ -1540,7 +1542,8 @@ static int shmem_replace_page(struct page **pagep, gfp_t
gfp,
* a nice clean interface for us to replace oldpage by newpage there.
*/
xa_lock_irq(_mapping->i_pages);
- error = shmem_replace_entry(swap_mapping, swap_index, oldpage, newpage);
+ error = shmem_replace_entry(swap_mapping, swp_offset(entry),
+ oldpage, newpage);
if (!error) {
__inc_node_page_state(newpage, NR_FILE_PAGES);
__dec_node_page_state(oldpage, NR_FILE_PAGES);
--
2.19.1.1215.g8438c0b245-goog
[PATCH] mm: fix swap offset when replacing shmem page
We used to have a single swap address space with swp_entry_t.val
as its radix tree index. This is not the case anymore. Now Each
swp_type() has its own address space and should use swp_offset()
as radix tree index.
Signed-off-by: Yu Zhao
---
mm/shmem.c | 11 +++
1 file changed, 7 insertions(+), 4 deletions(-)
diff --git a/mm/shmem.c b/mm/shmem.c
index d44991ea5ed4..a92c6ae26915 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -1509,11 +1509,13 @@ static int shmem_replace_page(struct page **pagep,
gfp_t gfp,
{
struct page *oldpage, *newpage;
struct address_space *swap_mapping;
- pgoff_t swap_index;
+ swp_entry_t entry;
int error;
+ VM_BUG_ON(PageSwapCache(*pagep));
+
oldpage = *pagep;
- swap_index = page_private(oldpage);
+ entry.val = page_private(oldpage);
swap_mapping = page_mapping(oldpage);
/*
@@ -1532,7 +1534,7 @@ static int shmem_replace_page(struct page **pagep, gfp_t
gfp,
__SetPageLocked(newpage);
__SetPageSwapBacked(newpage);
SetPageUptodate(newpage);
- set_page_private(newpage, swap_index);
+ set_page_private(newpage, entry.val);
SetPageSwapCache(newpage);
/*
@@ -1540,7 +1542,8 @@ static int shmem_replace_page(struct page **pagep, gfp_t
gfp,
* a nice clean interface for us to replace oldpage by newpage there.
*/
xa_lock_irq(_mapping->i_pages);
- error = shmem_replace_entry(swap_mapping, swap_index, oldpage, newpage);
+ error = shmem_replace_entry(swap_mapping, swp_offset(entry),
+ oldpage, newpage);
if (!error) {
__inc_node_page_state(newpage, NR_FILE_PAGES);
__dec_node_page_state(oldpage, NR_FILE_PAGES);
--
2.19.1.1215.g8438c0b245-goog
