Fixes: 418a3ab1e778 (mm/balloon_compaction: List interfaces)
A #GP is reported in the guest when requesting balloon inflation via
virtio-balloon. The reason is that the virtio-balloon driver has
removed the page from its internal page list (via balloon_page_pop),
but balloon_page_enqueue_one also calls "list_del" to do the removal.
So remove the list_del in balloon_page_enqueue_one, and have the callers
do the page removal from their own page lists.
Signed-off-by: Wei Wang <wei.w.wang@xxxxxxxxx>
---
mm/balloon_compaction.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/mm/balloon_compaction.c b/mm/balloon_compaction.c
index 83a7b61..1a5ddc4 100644
--- a/mm/balloon_compaction.c
+++ b/mm/balloon_compaction.c
@@ -11,6 +11,7 @@
#include <linux/export.h>
#include <linux/balloon_compaction.h>
+/* Callers ensure that @page has been removed from its original list. */
static void balloon_page_enqueue_one(struct balloon_dev_info *b_dev_info,
struct page *page)
{
@@ -21,7 +22,6 @@ static void balloon_page_enqueue_one(struct balloon_dev_info *b_dev_info,
* memory corruption is possible and we should stop execution.
*/
BUG_ON(!trylock_page(page));
- list_del(&page->lru);
balloon_page_insert(b_dev_info, page);
unlock_page(page);
__count_vm_event(BALLOON_INFLATE);
@@ -47,6 +47,7 @@ size_t balloon_page_list_enqueue(struct balloon_dev_info *b_dev_info,
spin_lock_irqsave(&b_dev_info->pages_lock, flags);
list_for_each_entry_safe(page, tmp, pages, lru) {
+ list_del(&page->lru);
balloon_page_enqueue_one(b_dev_info, page);
n_pages++;
}
--
2.7.4
