mm: Convert delete_from_swap_cache to XArray

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 <willy@infradead.org>

diff --git a/include/linux/swap.h b/include/linux/swap.h
index 112cebcf0402da2212eb390a1cd2f15d8c9fb1e6..cb479bf5842e2c05d2f86d7f669c9e9154383b30 100644 (file)
--- a/include/linux/swap.h
+++ b/include/linux/swap.h
@@ -403,7 +403,7 @@ 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);
@@ -557,7 +557,8 @@ 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 850314c2c3abb2ad0ee40c8d3becb5ddb755247f..f393c994cc602bf449a5c5566da1546c82ef6d18 100644 (file)
--- a/mm/swap_state.c
+++ b/mm/swap_state.c
@@ -154,23 +154,22 @@ unlock:
  * 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, &address_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(&address_space->i_pages, idx + i);
+               void *entry = xas_store(&xas, NULL);
+               VM_BUG_ON_PAGE(entry != page + i, entry);
                set_page_private(page + i, 0);
+               xas_next(&xas);
        }
        ClearPageSwapCache(page);
        address_space->nrpages -= nr;
@@ -243,14 +242,11 @@ fail:
  */
 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(&address_space->i_pages);
-       __delete_from_swap_cache(page);
+       __delete_from_swap_cache(page, entry);
        xa_unlock_irq(&address_space->i_pages);
 
        put_swap_page(page, entry);

diff --git a/mm/vmscan.c b/mm/vmscan.c
index c7ce2c1612259c45896bae9739a288966a28c970..80f731cf974e0fc99dfb1f3f285867b6b242090e 100644 (file)
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -923,7 +923,7 @@ 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(&mapping->i_pages, flags);
                put_swap_page(page, swap);
        } else {