From: Henry Burns <[email protected]> commit 810481a246089117d98e3373a3cb735c3efc1f90 upstream.
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. [[email protected]: fix trylock_page return value test, per Shakeel] Link: http://lkml.kernel.org/r/[email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Henry Burns <[email protected]> Suggested-by: Vitaly Wool <[email protected]> Acked-by: Vitaly Wool <[email protected]> Acked-by: David Rientjes <[email protected]> Reviewed-by: Shakeel Butt <[email protected]> Cc: Vitaly Vul <[email protected]> Cc: Mike Rapoport <[email protected]> Cc: Xidong Wang <[email protected]> Cc: Jonathan Adams <[email protected]> Cc: <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- mm/z3fold.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) --- 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 ad 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);
