From: Henry Burns henryburns@google.com
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.
[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 henryburns@google.com Suggested-by: Vitaly Wool vitalywool@gmail.com Acked-by: Vitaly Wool vitalywool@gmail.com Acked-by: David Rientjes rientjes@google.com Reviewed-by: Shakeel Butt shakeelb@google.com Cc: Vitaly Vul vitaly.vul@sony.com Cc: Mike Rapoport rppt@linux.vnet.ibm.com Cc: Xidong Wang wangxidong_97@163.com Cc: Jonathan Adams jwadams@google.com Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Linus Torvalds torvalds@linux-foundation.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- 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);