From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qk0-f199.google.com (mail-qk0-f199.google.com [209.85.220.199]) by kanga.kvack.org (Postfix) with ESMTP id 1B5C46B02BC for ; Wed, 2 Nov 2016 15:34:13 -0400 (EDT) Received: by mail-qk0-f199.google.com with SMTP id i34so24642883qkh.1 for ; Wed, 02 Nov 2016 12:34:13 -0700 (PDT) Received: from mx1.redhat.com (mx1.redhat.com. [209.132.183.28]) by mx.google.com with ESMTPS id d29si1941110qtb.31.2016.11.02.12.34.12 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 02 Nov 2016 12:34:12 -0700 (PDT) From: Andrea Arcangeli Subject: [PATCH 28/33] userfaultfd: shmem: lock the page before adding it to pagecache Date: Wed, 2 Nov 2016 20:34:00 +0100 Message-Id: <1478115245-32090-29-git-send-email-aarcange@redhat.com> In-Reply-To: <1478115245-32090-1-git-send-email-aarcange@redhat.com> References: <1478115245-32090-1-git-send-email-aarcange@redhat.com> Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton Cc: linux-mm@kvack.org, Michael Rapoport , "Dr. David Alan Gilbert"@v2.random, " , Mike Kravetz , Shaohua Li , Pavel Emelyanov "@v2.random A VM_BUG_ON triggered on the shmem selftest. Signed-off-by: Andrea Arcangeli --- mm/shmem.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/mm/shmem.c b/mm/shmem.c index fe469e5..5d39f88 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -2214,6 +2214,10 @@ int shmem_mcopy_atomic_pte(struct mm_struct *dst_mm, *pagep = NULL; } + VM_BUG_ON(PageLocked(page) || PageSwapBacked(page)); + __SetPageLocked(page); + __SetPageSwapBacked(page); + ret = mem_cgroup_try_charge(page, dst_mm, gfp, &memcg, false); if (ret) goto out_release; @@ -2263,6 +2267,7 @@ int shmem_mcopy_atomic_pte(struct mm_struct *dst_mm, out_release_uncharge: mem_cgroup_cancel_charge(page, memcg, false); out_release: + unlock_page(page); put_page(page); out_dec_used_blocks: if (sbinfo->max_blocks) -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org