From 810481a246089117d98e3373a3cb735c3efc1f90 Mon Sep 17 00:00:00 2001 From: Henry Burns Date: Thu, 11 Jul 2019 20:52:14 -0700 Subject: [PATCH] mm/z3fold.c: lock z3fold page before __SetPageMovable() Following zsmalloc.c's example we call trylock_page() and unlock_page(). Also make z3fold_page_migrate() assert that newpage is passed in locked, as per the documentation. [akpm@linux-foundation.org: fix trylock_page return value test, per Shakeel] Link: http://lkml.kernel.org/r/20190702005122.41036-1-henryburns@google.com Link: http://lkml.kernel.org/r/20190702233538.52793-1-henryburns@google.com Signed-off-by: Henry Burns Suggested-by: Vitaly Wool Acked-by: Vitaly Wool Acked-by: David Rientjes Reviewed-by: Shakeel Butt Cc: Vitaly Vul Cc: Mike Rapoport Cc: Xidong Wang Cc: Jonathan Adams Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/z3fold.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/mm/z3fold.c b/mm/z3fold.c index 985732c8b025..dfcd69d08c1e 100644 --- a/mm/z3fold.c +++ b/mm/z3fold.c @@ -924,7 +924,16 @@ retry: set_bit(PAGE_HEADLESS, &page->private); goto headless; } - __SetPageMovable(page, pool->inode->i_mapping); + if (can_sleep) { + lock_page(page); + __SetPageMovable(page, pool->inode->i_mapping); + unlock_page(page); + } else { + if (trylock_page(page)) { + __SetPageMovable(page, pool->inode->i_mapping); + unlock_page(page); + } + } z3fold_page_lock(zhdr); found: @@ -1331,6 +1340,7 @@ static int z3fold_page_migrate(struct address_space *mapping, struct page *newpa VM_BUG_ON_PAGE(!PageMovable(page), page); VM_BUG_ON_PAGE(!PageIsolated(page), page); + VM_BUG_ON_PAGE(!PageLocked(newpage), newpage); zhdr = page_address(page); pool = zhdr_to_pool(zhdr);