z3fold: fix memory leak in kmem cache (63398413) · Commits · 戴 / test

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. Link: http://lkml.kernel.org/r/20190917185352.44cf285d3ebd9e64548de5de@gmail.com Signed-off-by:

Vitaly Wool <vitalywool@gmail.com> Reported-by:

Markus Linnala <markus.linnala@gmail.com> Tested-by:

Markus Linnala <markus.linnala@gmail.com> Cc: Dan Streetman <ddstreet@ieee.org> Cc: Henry Burns <henrywolfeburns@gmail.com> Cc: Shakeel Butt <shakeelb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: <stable@vger.kernel.org> Signed-off-by:

Andrew Morton <akpm@linux-foundation.org> Signed-off-by:

Linus Torvalds <torvalds@linux-foundation.org>

mm/z3fold.c

+9 −6

Original line number	Diff line number	Diff line
		@@ -295,14 +295,11 @@ 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);
		@@ -310,6 +307,12 @@ 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);
		@@ -930,7 +933,7 @@ retry:
		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;

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