From mboxrd@z Thu Jan 1 00:00:00 1970 From: bugzilla-daemon@bugzilla.kernel.org Subject: [Bug 101011] Kernel Oops when disconnecting a mounted ext4 usb stick Date: Fri, 14 Aug 2015 18:39:43 +0000 Message-ID: References: Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Return-path: Received: from mail.kernel.org ([198.145.29.136]:41515 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752053AbbHNSjs (ORCPT ); Fri, 14 Aug 2015 14:39:48 -0400 Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 1373B2081B for ; Fri, 14 Aug 2015 18:39:47 +0000 (UTC) Received: from bugzilla2.web.kernel.org (bugzilla2.web.kernel.org [172.20.200.52]) by mail.kernel.org (Postfix) with ESMTP id B1B0D2080A for ; Fri, 14 Aug 2015 18:39:43 +0000 (UTC) In-Reply-To: Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: linux-scsi@vger.kernel.org https://bugzilla.kernel.org/show_bug.cgi?id=101011 --- Comment #8 from Theodore Tso --- On Fri, Aug 14, 2015 at 11:02:14AM +0000, bugzilla-daemon@bugzilla.kernel.org wrote: > https://bugzilla.kernel.org/show_bug.cgi?id=101011 > > I can also confirm that this bug is present in latest stable kernel (4.1.5) and > reverting commit from comment 6 seems to fix it. Christoph, I've since gotten two reports from users that reverting your commit: "08439fec266c3: ext4: remove block_device_ejected" fixes a crash when a USB stick is yanked from their system. Looking at the reported stack dump, it looks like the crash is happening in account_page_dirtied() when it updates some bdi-specific statistics. I haven't been paying attention to the recent changes in how bdi gets torn down after the device gets removed, and in fact finding the recent changes wasn't obvioius enough after doing a brief search, but it seems to me that if reverting this patch is making any kind of differences, then the assertion in the commit description: bdi->dev now never goes away, so this function became useless. it implies that bdi->dev *does* become NULL, and checking for this is useful. In any case, I don't see any harm in reverting this commit; what do you think? Thanks, - Ted -- You are receiving this mail because: You are the assignee for the bug.