From: Vitaly Wool <vitalyw...@gmail.com> commit 63398413c00c7836ea87a1fa205c91d2199b25cf upstream.
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/20190917185352.44cf285d3ebd9e64548de...@gmail.com Signed-off-by: Vitaly Wool <vitalyw...@gmail.com> Reported-by: Markus Linnala <markus.linn...@gmail.com> Tested-by: Markus Linnala <markus.linn...@gmail.com> Cc: Dan Streetman <ddstr...@ieee.org> Cc: Henry Burns <henrywolfebu...@gmail.com> Cc: Shakeel Butt <shake...@google.com> Cc: Vlastimil Babka <vba...@suse.cz> Cc: <sta...@vger.kernel.org> Signed-off-by: Andrew Morton <a...@linux-foundation.org> Signed-off-by: Linus Torvalds <torva...@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org> --- mm/z3fold.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-) --- a/mm/z3fold.c +++ b/mm/z3fold.c @@ -297,14 +297,11 @@ static void z3fold_unregister_migration( } /* 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); @@ -312,6 +309,12 @@ static struct z3fold_header *init_z3fold 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); @@ -932,7 +935,7 @@ 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;
