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-rw-r--r--include/linux/swap.h17
-rw-r--r--mm/shmem.c3
-rw-r--r--mm/swap_state.c57
-rw-r--r--mm/swapfile.c2
-rw-r--r--mm/vmscan.c2
5 files changed, 69 insertions, 12 deletions
diff --git a/include/linux/swap.h b/include/linux/swap.h
index 51ec9cdb92c0..8a4c592698a9 100644
--- a/include/linux/swap.h
+++ b/include/linux/swap.h
@@ -414,9 +414,13 @@ extern struct address_space *swapper_spaces[];
extern unsigned long total_swapcache_pages(void);
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 void __delete_from_swap_cache(struct page *, swp_entry_t entry);
+extern int add_to_swap_cache(struct page *page, swp_entry_t entry,
+ gfp_t gfp, void **shadowp);
+extern void __delete_from_swap_cache(struct page *page,
+ swp_entry_t entry, void *shadow);
extern void delete_from_swap_cache(struct page *);
+extern void clear_shadow_from_swap_cache(int type, unsigned long begin,
+ unsigned long end);
extern void free_page_and_swap_cache(struct page *);
extern void free_pages_and_swap_cache(struct page **, int);
extern struct page *lookup_swap_cache(swp_entry_t entry,
@@ -570,13 +574,13 @@ static inline int add_to_swap(struct page *page)
}
static inline int add_to_swap_cache(struct page *page, swp_entry_t entry,
- gfp_t gfp_mask)
+ gfp_t gfp_mask, void **shadowp)
{
return -1;
}
static inline void __delete_from_swap_cache(struct page *page,
- swp_entry_t entry)
+ swp_entry_t entry, void *shadow)
{
}
@@ -584,6 +588,11 @@ static inline void delete_from_swap_cache(struct page *page)
{
}
+static inline void clear_shadow_from_swap_cache(int type, unsigned long begin,
+ unsigned long end)
+{
+}
+
static inline int page_swapcount(struct page *page)
{
return 0;
diff --git a/mm/shmem.c b/mm/shmem.c
index eb6b36d89722..49bde088a7ea 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -1434,7 +1434,8 @@ static int shmem_writepage(struct page *page, struct writeback_control *wbc)
list_add(&info->swaplist, &shmem_swaplist);
if (add_to_swap_cache(page, swap,
- __GFP_HIGH | __GFP_NOMEMALLOC | __GFP_NOWARN) == 0) {
+ __GFP_HIGH | __GFP_NOMEMALLOC | __GFP_NOWARN,
+ NULL) == 0) {
spin_lock_irq(&info->lock);
shmem_recalc_inode(inode);
info->swapped++;
diff --git a/mm/swap_state.c b/mm/swap_state.c
index e82f4f8b1f63..a29b33c7c236 100644
--- a/mm/swap_state.c
+++ b/mm/swap_state.c
@@ -110,12 +110,14 @@ void show_swap_cache_info(void)
* add_to_swap_cache resembles add_to_page_cache_locked on swapper_space,
* but sets SwapCache flag and private instead of mapping and index.
*/
-int add_to_swap_cache(struct page *page, swp_entry_t entry, gfp_t gfp)
+int add_to_swap_cache(struct page *page, swp_entry_t entry,
+ gfp_t gfp, void **shadowp)
{
struct address_space *address_space = swap_address_space(entry);
pgoff_t idx = swp_offset(entry);
XA_STATE_ORDER(xas, &address_space->i_pages, idx, compound_order(page));
unsigned long i, nr = hpage_nr_pages(page);
+ void *old;
VM_BUG_ON_PAGE(!PageLocked(page), page);
VM_BUG_ON_PAGE(PageSwapCache(page), page);
@@ -125,16 +127,25 @@ int add_to_swap_cache(struct page *page, swp_entry_t entry, gfp_t gfp)
SetPageSwapCache(page);
do {
+ unsigned long nr_shadows = 0;
+
xas_lock_irq(&xas);
xas_create_range(&xas);
if (xas_error(&xas))
goto unlock;
for (i = 0; i < nr; i++) {
VM_BUG_ON_PAGE(xas.xa_index != idx + i, page);
+ old = xas_load(&xas);
+ if (xa_is_value(old)) {
+ nr_shadows++;
+ if (shadowp)
+ *shadowp = old;
+ }
set_page_private(page + i, entry.val + i);
xas_store(&xas, page);
xas_next(&xas);
}
+ address_space->nrexceptional -= nr_shadows;
address_space->nrpages += nr;
__mod_node_page_state(page_pgdat(page), NR_FILE_PAGES, nr);
ADD_CACHE_INFO(add_total, nr);
@@ -154,7 +165,8 @@ 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, swp_entry_t entry)
+void __delete_from_swap_cache(struct page *page,
+ swp_entry_t entry, void *shadow)
{
struct address_space *address_space = swap_address_space(entry);
int i, nr = hpage_nr_pages(page);
@@ -166,12 +178,14 @@ void __delete_from_swap_cache(struct page *page, swp_entry_t entry)
VM_BUG_ON_PAGE(PageWriteback(page), page);
for (i = 0; i < nr; i++) {
- void *entry = xas_store(&xas, NULL);
+ void *entry = xas_store(&xas, shadow);
VM_BUG_ON_PAGE(entry != page, entry);
set_page_private(page + i, 0);
xas_next(&xas);
}
ClearPageSwapCache(page);
+ if (shadow)
+ address_space->nrexceptional += nr;
address_space->nrpages -= nr;
__mod_node_page_state(page_pgdat(page), NR_FILE_PAGES, -nr);
ADD_CACHE_INFO(del_total, nr);
@@ -208,7 +222,7 @@ int add_to_swap(struct page *page)
* Add it to the swap cache.
*/
err = add_to_swap_cache(page, entry,
- __GFP_HIGH|__GFP_NOMEMALLOC|__GFP_NOWARN);
+ __GFP_HIGH|__GFP_NOMEMALLOC|__GFP_NOWARN, NULL);
if (err)
/*
* add_to_swap_cache() doesn't return -EEXIST, so we can safely
@@ -246,13 +260,44 @@ void delete_from_swap_cache(struct page *page)
struct address_space *address_space = swap_address_space(entry);
xa_lock_irq(&address_space->i_pages);
- __delete_from_swap_cache(page, entry);
+ __delete_from_swap_cache(page, entry, NULL);
xa_unlock_irq(&address_space->i_pages);
put_swap_page(page, entry);
page_ref_sub(page, hpage_nr_pages(page));
}
+void clear_shadow_from_swap_cache(int type, unsigned long begin,
+ unsigned long end)
+{
+ unsigned long curr = begin;
+ void *old;
+
+ for (;;) {
+ unsigned long nr_shadows = 0;
+ swp_entry_t entry = swp_entry(type, curr);
+ struct address_space *address_space = swap_address_space(entry);
+ XA_STATE(xas, &address_space->i_pages, curr);
+
+ xa_lock_irq(&address_space->i_pages);
+ xas_for_each(&xas, old, end) {
+ if (!xa_is_value(old))
+ continue;
+ xas_store(&xas, NULL);
+ nr_shadows++;
+ }
+ address_space->nrexceptional -= nr_shadows;
+ xa_unlock_irq(&address_space->i_pages);
+
+ /* search the next swapcache until we meet end */
+ curr >>= SWAP_ADDRESS_SPACE_SHIFT;
+ curr++;
+ curr <<= SWAP_ADDRESS_SPACE_SHIFT;
+ if (curr > end)
+ break;
+ }
+}
+
/*
* If we are the only user, then try to free up the swap cache.
*
@@ -429,7 +474,7 @@ struct page *__read_swap_cache_async(swp_entry_t entry, gfp_t gfp_mask,
__SetPageSwapBacked(page);
/* May fail (-ENOMEM) if XArray node allocation failed. */
- if (add_to_swap_cache(page, entry, gfp_mask & GFP_RECLAIM_MASK)) {
+ if (add_to_swap_cache(page, entry, gfp_mask & GFP_RECLAIM_MASK, NULL)) {
put_swap_page(page, entry);
goto fail_unlock;
}
diff --git a/mm/swapfile.c b/mm/swapfile.c
index 82183432fdd0..e653eea1eb88 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -696,6 +696,7 @@ static void add_to_avail_list(struct swap_info_struct *p)
static void swap_range_free(struct swap_info_struct *si, unsigned long offset,
unsigned int nr_entries)
{
+ unsigned long begin = offset;
unsigned long end = offset + nr_entries - 1;
void (*swap_slot_free_notify)(struct block_device *, unsigned long);
@@ -721,6 +722,7 @@ static void swap_range_free(struct swap_info_struct *si, unsigned long offset,
swap_slot_free_notify(si->bdev, offset);
offset++;
}
+ clear_shadow_from_swap_cache(si->type, begin, end);
}
static void set_cluster_next(struct swap_info_struct *si, unsigned long next)
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 017f323318a3..e84c4dd08c4e 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -896,7 +896,7 @@ 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, swap);
+ __delete_from_swap_cache(page, swap, NULL);
xa_unlock_irqrestore(&mapping->i_pages, flags);
put_swap_page(page, swap);
workingset_eviction(page, target_memcg);
generated by cgit v1.2.3 (git 2.39.1) at 2024-07-07 13:54:51 +0000