From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail115-95.sinamail.sina.com.cn (mail115-95.sinamail.sina.com.cn [218.30.115.95]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2480B7F9 for ; Mon, 1 Jan 2024 01:55:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=sina.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=sina.com X-SMAIL-HELO: localhost.localdomain Received: from unknown (HELO localhost.localdomain)([113.118.70.64]) by sina.com (172.16.235.24) with ESMTP id 65921B8100004871; Mon, 1 Jan 2024 09:55:16 +0800 (CST) X-Sender: hdanton@sina.com X-Auth-ID: hdanton@sina.com Authentication-Results: sina.com; spf=none smtp.mailfrom=hdanton@sina.com; dkim=none header.i=none; dmarc=none action=none header.from=hdanton@sina.com X-SMAIL-MID: 15200245089584 X-SMAIL-UIID: 0DEB7DF064144DCD825404CC9C1C793E-20240101-095516-1 From: Hillf Danton To: Matthew Wilcox Cc: Genes Lists , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org Subject: Re: 6.6.8 stable: crash in folio_mark_dirty Date: Mon, 1 Jan 2024 09:55:04 +0800 Message-Id: <20240101015504.2446-1-hdanton@sina.com> In-Reply-To: References: <8bb29431064fc1f70a42edef75a8788dd4a0eecc.camel@sapience.com> <20231231012846.2355-1-hdanton@sina.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit On Sun, 31 Dec 2023 13:07:03 +0000 Matthew Wilcox > On Sun, Dec 31, 2023 at 09:28:46AM +0800, Hillf Danton wrote: > > On Sat, Dec 30, 2023 at 10:23:26AM -0500 Genes Lists > > > Apologies in advance, but I cannot git bisect this since machine was > > > running for 10 days on 6.6.8 before this happened. > > > > > > Dec 30 07:00:36 s6 kernel: ------------[ cut here ]------------ > > > Dec 30 07:00:36 s6 kernel: WARNING: CPU: 0 PID: 521524 at mm/page-writeback.c:2668 __folio_mark_dirty (??:?) > > > Dec 30 07:00:36 s6 kernel: CPU: 0 PID: 521524 Comm: rsync Not tainted 6.6.8-stable-1 #13 d238f5ab6a206cdb0cc5cd72f8688230f23d58df > > > Dec 30 07:00:36 s6 kernel: block_dirty_folio (??:?) > > > Dec 30 07:00:36 s6 kernel: unmap_page_range (??:?) > > > Dec 30 07:00:36 s6 kernel: unmap_vmas (??:?) > > > Dec 30 07:00:36 s6 kernel: exit_mmap (??:?) > > > Dec 30 07:00:36 s6 kernel: __mmput (??:?) > > > Dec 30 07:00:36 s6 kernel: do_exit (??:?) > > > Dec 30 07:00:36 s6 kernel: do_group_exit (??:?) > > > Dec 30 07:00:36 s6 kernel: __x64_sys_exit_group (??:?) > > > Dec 30 07:00:36 s6 kernel: do_syscall_64 (??:?) > > > > See what comes out if race is handled. > > Only for thoughts. > > I don't think this can happen. Look at the call trace; > block_dirty_folio() is called from unmap_page_range(). That means the > page is in the page tables. We unmap the pages in a folio from the > page tables before we set folio->mapping to NULL. Look at > invalidate_inode_pages2_range() for example: > > unmap_mapping_pages(mapping, indices[i], > (1 + end - indices[i]), false); > folio_lock(folio); > folio_wait_writeback(folio); > if (folio_mapped(folio)) > unmap_mapping_folio(folio); > BUG_ON(folio_mapped(folio)); > if (!invalidate_complete_folio2(mapping, folio)) > What is missed here is the same check [1] in invalidate_inode_pages2_range(), so I built no wheel. folio_lock(folio); if (unlikely(folio->mapping != mapping)) { folio_unlock(folio); continue; } [1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/mm/truncate.c#n658