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Diffstat (limited to 'mm/balloon_compaction.c')
-rw-r--r--mm/balloon_compaction.c21
1 files changed, 13 insertions, 8 deletions
diff --git a/mm/balloon_compaction.c b/mm/balloon_compaction.c
index d3e00731e262..2a4a649805c1 100644
--- a/mm/balloon_compaction.c
+++ b/mm/balloon_compaction.c
@@ -94,13 +94,8 @@ size_t balloon_page_list_dequeue(struct balloon_dev_info *b_dev_info,
if (!trylock_page(page))
continue;
- if (IS_ENABLED(CONFIG_BALLOON_COMPACTION) &&
- PageIsolated(page)) {
- /* raced with isolation */
- unlock_page(page);
- continue;
- }
- balloon_page_delete(page);
+ list_del(&page->lru);
+ balloon_page_finalize(page);
__count_vm_event(BALLOON_DEFLATE);
list_add(&page->lru, pages);
unlock_page(page);
@@ -211,6 +206,9 @@ static bool balloon_page_isolate(struct page *page, isolate_mode_t mode)
struct balloon_dev_info *b_dev_info = balloon_page_device(page);
unsigned long flags;
+ if (!b_dev_info)
+ return false;
+
spin_lock_irqsave(&b_dev_info->pages_lock, flags);
list_del(&page->lru);
b_dev_info->isolated_pages++;
@@ -224,6 +222,10 @@ static void balloon_page_putback(struct page *page)
struct balloon_dev_info *b_dev_info = balloon_page_device(page);
unsigned long flags;
+ /* Isolated balloon pages cannot get deflated. */
+ if (WARN_ON_ONCE(!b_dev_info))
+ return;
+
spin_lock_irqsave(&b_dev_info->pages_lock, flags);
list_add(&page->lru, &b_dev_info->pages);
b_dev_info->isolated_pages--;
@@ -239,6 +241,10 @@ static int balloon_page_migrate(struct page *newpage, struct page *page,
VM_BUG_ON_PAGE(!PageLocked(page), page);
VM_BUG_ON_PAGE(!PageLocked(newpage), newpage);
+ /* Isolated balloon pages cannot get deflated. */
+ if (WARN_ON_ONCE(!balloon))
+ return -EAGAIN;
+
return balloon->migratepage(balloon, newpage, page, mode);
}
@@ -247,6 +253,5 @@ const struct movable_operations balloon_mops = {
.isolate_page = balloon_page_isolate,
.putback_page = balloon_page_putback,
};
-EXPORT_SYMBOL_GPL(balloon_mops);
#endif /* CONFIG_BALLOON_COMPACTION */