Currently there is a leak in init_z3fold_page() -- it allocates
handles from kmem cache even for headless pages, but then they are
never used and never freed, so eventually kmem cache may get
exhausted. This patch provides a fix for that.
Reported-by: Markus Linnala <markus.linnala@xxxxxxxxx>
Signed-off-by: Vitaly Wool <vitalywool@xxxxxxxxx>
---
mm/z3fold.c | 15 +++++++++------
1 file changed, 9 insertions(+), 6 deletions(-)
diff --git a/mm/z3fold.c b/mm/z3fold.c
index 6397725b5ec6..7dffef2599c3 100644
--- a/mm/z3fold.c
+++ b/mm/z3fold.c
@@ -301,14 +301,11 @@ static void z3fold_unregister_migration(struct z3fold_pool *pool)
}
/* Initializes the z3fold header of a newly allocated z3fold page */
-static struct z3fold_header *init_z3fold_page(struct page *page,
+static struct z3fold_header *init_z3fold_page(struct page *page, bool headless,
struct z3fold_pool *pool, gfp_t gfp)
{
struct z3fold_header *zhdr = page_address(page);
- struct z3fold_buddy_slots *slots = alloc_slots(pool, gfp);
-
- if (!slots)
- return NULL;
+ struct z3fold_buddy_slots *slots;
INIT_LIST_HEAD(&page->lru);
clear_bit(PAGE_HEADLESS, &page->private);
@@ -316,6 +313,12 @@ static struct z3fold_header *init_z3fold_page(struct page *page,
clear_bit(NEEDS_COMPACTING, &page->private);
clear_bit(PAGE_STALE, &page->private);
clear_bit(PAGE_CLAIMED, &page->private);
+ if (headless)
+ return zhdr;
+
+ slots = alloc_slots(pool, gfp);
+ if (!slots)
+ return NULL;
spin_lock_init(&zhdr->page_lock);
kref_init(&zhdr->refcount);
@@ -962,7 +965,7 @@ static int z3fold_alloc(struct z3fold_pool *pool, size_t size, gfp_t gfp,
if (!page)
return -ENOMEM;
- zhdr = init_z3fold_page(page, pool, gfp);
+ zhdr = init_z3fold_page(page, bud == HEADLESS, pool, gfp);
if (!zhdr) {
__free_page(page);
return -ENOMEM;
--
2.17.1
