[PATCH v8 38/63] mm: Convert delete_from_swap_cache to XArray

[Matthew Wilcox]

From: Matthew Wilcox 

Both callers of __delete_from_swap_cache have the swp_entry_t already,
so pass that in to make constructing the XA_STATE easier.

Signed-off-by: Matthew Wilcox 
---
 include/linux/swap.h |  5 +++--
 mm/swap_state.c  | 24 ++--
 mm/vmscan.c  |  2 +-
 3 files changed, 14 insertions(+), 17 deletions(-)

diff --git a/include/linux/swap.h b/include/linux/swap.h
index dab96af23d96..0b6a47a46c55 100644
--- a/include/linux/swap.h
+++ b/include/linux/swap.h
@@ -404,7 +404,7 @@ extern void show_swap_cache_info(void);
 extern int add_to_swap(struct page *page);
 extern int add_to_swap_cache(struct page *, swp_entry_t, gfp_t);
 extern int __add_to_swap_cache(struct page *page, swp_entry_t entry);
-extern void __delete_from_swap_cache(struct page *);
+extern void __delete_from_swap_cache(struct page *, swp_entry_t entry);
 extern void delete_from_swap_cache(struct page *);
 extern void free_page_and_swap_cache(struct page *);
 extern void free_pages_and_swap_cache(struct page **, int);
@@ -564,7 +564,8 @@ static inline int add_to_swap_cache(struct page *page, 
swp_entry_t entry,
return -1;
 }
 
-static inline void __delete_from_swap_cache(struct page *page)
+static inline void __delete_from_swap_cache(struct page *page,
+   swp_entry_t entry)
 {
 }
 
diff --git a/mm/swap_state.c b/mm/swap_state.c
index 329736723d36..21218f6e438b 100644
--- a/mm/swap_state.c
+++ b/mm/swap_state.c
@@ -154,23 +154,22 @@ int add_to_swap_cache(struct page *page, swp_entry_t 
entry, gfp_t gfp)
  * This must be called only on pages that have
  * been verified to be in the swap cache.
  */
-void __delete_from_swap_cache(struct page *page)
+void __delete_from_swap_cache(struct page *page, swp_entry_t entry)
 {
-   struct address_space *address_space;
+   struct address_space *address_space = swap_address_space(entry);
int i, nr = hpage_nr_pages(page);
-   swp_entry_t entry;
-   pgoff_t idx;
+   pgoff_t idx = swp_offset(entry);
+   XA_STATE(xas, _space->i_pages, idx);
 
VM_BUG_ON_PAGE(!PageLocked(page), page);
VM_BUG_ON_PAGE(!PageSwapCache(page), page);
VM_BUG_ON_PAGE(PageWriteback(page), page);
 
-   entry.val = page_private(page);
-   address_space = swap_address_space(entry);
-   idx = swp_offset(entry);
for (i = 0; i < nr; i++) {
-   radix_tree_delete(_space->i_pages, idx + i);
+   void *entry = xas_store(, NULL);
+   VM_BUG_ON_PAGE(entry != page + i, entry);
set_page_private(page + i, 0);
+   xas_next();
}
ClearPageSwapCache(page);
address_space->nrpages -= nr;
@@ -246,14 +245,11 @@ int add_to_swap(struct page *page)
  */
 void delete_from_swap_cache(struct page *page)
 {
-   swp_entry_t entry;
-   struct address_space *address_space;
-
-   entry.val = page_private(page);
+   swp_entry_t entry = { .val = page_private(page) };
+   struct address_space *address_space = swap_address_space(entry);
 
-   address_space = swap_address_space(entry);
xa_lock_irq(_space->i_pages);
-   __delete_from_swap_cache(page);
+   __delete_from_swap_cache(page, entry);
xa_unlock_irq(_space->i_pages);
 
put_swap_page(page, entry);
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 22bd3720b318..728d7e57cf11 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -689,7 +689,7 @@ static int __remove_mapping(struct address_space *mapping, 
struct page *page,
if (PageSwapCache(page)) {
swp_entry_t swap = { .val = page_private(page) };
mem_cgroup_swapout(page, swap);
-   __delete_from_swap_cache(page);
+   __delete_from_swap_cache(page, swap);
xa_unlock_irqrestore(>i_pages, flags);
put_swap_page(page, swap);
} else {
-- 
2.16.1

[PATCH v8 38/63] mm: Convert delete_from_swap_cache to XArray

[Matthew Wilcox]

From: Matthew Wilcox 

Both callers of __delete_from_swap_cache have the swp_entry_t already,
so pass that in to make constructing the XA_STATE easier.

Signed-off-by: Matthew Wilcox 
---
 include/linux/swap.h |  5 +++--
 mm/swap_state.c  | 24 ++--
 mm/vmscan.c  |  2 +-
 3 files changed, 14 insertions(+), 17 deletions(-)

diff --git a/include/linux/swap.h b/include/linux/swap.h
index dab96af23d96..0b6a47a46c55 100644
--- a/include/linux/swap.h
+++ b/include/linux/swap.h
@@ -404,7 +404,7 @@ extern void show_swap_cache_info(void);
 extern int add_to_swap(struct page *page);
 extern int add_to_swap_cache(struct page *, swp_entry_t, gfp_t);
 extern int __add_to_swap_cache(struct page *page, swp_entry_t entry);
-extern void __delete_from_swap_cache(struct page *);
+extern void __delete_from_swap_cache(struct page *, swp_entry_t entry);
 extern void delete_from_swap_cache(struct page *);
 extern void free_page_and_swap_cache(struct page *);
 extern void free_pages_and_swap_cache(struct page **, int);
@@ -564,7 +564,8 @@ static inline int add_to_swap_cache(struct page *page, 
swp_entry_t entry,
return -1;
 }
 
-static inline void __delete_from_swap_cache(struct page *page)
+static inline void __delete_from_swap_cache(struct page *page,
+   swp_entry_t entry)
 {
 }
 
diff --git a/mm/swap_state.c b/mm/swap_state.c
index 329736723d36..21218f6e438b 100644
--- a/mm/swap_state.c
+++ b/mm/swap_state.c
@@ -154,23 +154,22 @@ int add_to_swap_cache(struct page *page, swp_entry_t 
entry, gfp_t gfp)
  * This must be called only on pages that have
  * been verified to be in the swap cache.
  */
-void __delete_from_swap_cache(struct page *page)
+void __delete_from_swap_cache(struct page *page, swp_entry_t entry)
 {
-   struct address_space *address_space;
+   struct address_space *address_space = swap_address_space(entry);
int i, nr = hpage_nr_pages(page);
-   swp_entry_t entry;
-   pgoff_t idx;
+   pgoff_t idx = swp_offset(entry);
+   XA_STATE(xas, _space->i_pages, idx);
 
VM_BUG_ON_PAGE(!PageLocked(page), page);
VM_BUG_ON_PAGE(!PageSwapCache(page), page);
VM_BUG_ON_PAGE(PageWriteback(page), page);
 
-   entry.val = page_private(page);
-   address_space = swap_address_space(entry);
-   idx = swp_offset(entry);
for (i = 0; i < nr; i++) {
-   radix_tree_delete(_space->i_pages, idx + i);
+   void *entry = xas_store(, NULL);
+   VM_BUG_ON_PAGE(entry != page + i, entry);
set_page_private(page + i, 0);
+   xas_next();
}
ClearPageSwapCache(page);
address_space->nrpages -= nr;
@@ -246,14 +245,11 @@ int add_to_swap(struct page *page)
  */
 void delete_from_swap_cache(struct page *page)
 {
-   swp_entry_t entry;
-   struct address_space *address_space;
-
-   entry.val = page_private(page);
+   swp_entry_t entry = { .val = page_private(page) };
+   struct address_space *address_space = swap_address_space(entry);
 
-   address_space = swap_address_space(entry);
xa_lock_irq(_space->i_pages);
-   __delete_from_swap_cache(page);
+   __delete_from_swap_cache(page, entry);
xa_unlock_irq(_space->i_pages);
 
put_swap_page(page, entry);
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 22bd3720b318..728d7e57cf11 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -689,7 +689,7 @@ static int __remove_mapping(struct address_space *mapping, 
struct page *page,
if (PageSwapCache(page)) {
swp_entry_t swap = { .val = page_private(page) };
mem_cgroup_swapout(page, swap);
-   __delete_from_swap_cache(page);
+   __delete_from_swap_cache(page, swap);
xa_unlock_irqrestore(>i_pages, flags);
put_swap_page(page, swap);
} else {
-- 
2.16.1