From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 89C5AC433F5 for ; Sat, 27 Nov 2021 13:13:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1355016AbhK0NQN (ORCPT ); Sat, 27 Nov 2021 08:16:13 -0500 Received: from ams.source.kernel.org ([145.40.68.75]:50892 "EHLO ams.source.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239018AbhK0NOL (ORCPT ); Sat, 27 Nov 2021 08:14:11 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 559C4B81B58 for ; Sat, 27 Nov 2021 13:10:56 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id BF4B3C53FBF; Sat, 27 Nov 2021 13:10:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1638018655; bh=0REmCfJEHZUkZIruD9zMi4zSkibpkObELj7k7Nbmbzw=; h=Subject:To:Cc:From:Date:From; b=aiBd+BIkmt0wpZrEKqMSrCejBboBTork6m9VZjvm6S2YTv/EWW5FL/u62AhDDpfI2 ZuecmQkq+o+Xna7K7nvKh+993yhOzJjY4m9xDfWyT1abxl+FNEzkudnsMI4QkcLp6u QXX04Lj2HLQQz0Z2eWzYUBag5U0X/3aGgnUXXzuc= Subject: FAILED: patch "[PATCH] fuse: release pipe buf after last use" failed to apply to 4.4-stable tree To: mszeredi@redhat.com, jmforbes@linuxtx.org, stable@vger.kernel.org Cc: From: Date: Sat, 27 Nov 2021 14:10:52 +0100 Message-ID: <163801865218547@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org The patch below does not apply to the 4.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 473441720c8616dfaf4451f9c7ea14f0eb5e5d65 Mon Sep 17 00:00:00 2001 From: Miklos Szeredi Date: Thu, 25 Nov 2021 14:05:18 +0100 Subject: [PATCH] fuse: release pipe buf after last use Checking buf->flags should be done before the pipe_buf_release() is called on the pipe buffer, since releasing the buffer might modify the flags. This is exactly what page_cache_pipe_buf_release() does, and which results in the same VM_BUG_ON_PAGE(PageLRU(page)) that the original patch was trying to fix. Reported-by: Justin Forbes Fixes: 712a951025c0 ("fuse: fix page stealing") Cc: # v2.6.35 Signed-off-by: Miklos Szeredi diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c index 79f7eda49e06..cd54a529460d 100644 --- a/fs/fuse/dev.c +++ b/fs/fuse/dev.c @@ -847,17 +847,17 @@ static int fuse_try_move_page(struct fuse_copy_state *cs, struct page **pagep) replace_page_cache_page(oldpage, newpage); + get_page(newpage); + + if (!(buf->flags & PIPE_BUF_FLAG_LRU)) + lru_cache_add(newpage); + /* * Release while we have extra ref on stolen page. Otherwise * anon_pipe_buf_release() might think the page can be reused. */ pipe_buf_release(cs->pipe, buf); - get_page(newpage); - - if (!(buf->flags & PIPE_BUF_FLAG_LRU)) - lru_cache_add(newpage); - err = 0; spin_lock(&cs->req->waitq.lock); if (test_bit(FR_ABORTED, &cs->req->flags))