From mboxrd@z Thu Jan 1 00:00:00 1970 From: Josh Boyer Subject: Re: [PATCH] fs: Fix mod_timer crash when removing USB sticks Date: Fri, 13 Jan 2012 00:42:07 -0500 Message-ID: References: <1326402935-31002-1-git-send-email-taysom@chromium.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Cc: Paul Taysom , Mandeep Baines , Olof Johansson , Greg KH , Jens Axboe , Theodore Tso , Andrew Morton , linux-usb-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Alexander Viro , linux-fsdevel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Paul Taysom Return-path: In-Reply-To: <1326402935-31002-1-git-send-email-taysom-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org> Sender: linux-usb-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-fsdevel.vger.kernel.org On Thu, Jan 12, 2012 at 4:15 PM, Paul Taysom wrote: > From: Paul Taysom > > A USB stick with a ext file system on it, would occasionally crash > when the stick was pulled. > > The problem was a timer was being set on the Backing Device Interface, > bdi, after the USB device had been removed and the bdi had been > unregistered. The bdi would then be later reinitialized by zeroing > the timer without removing from the timer from the timer queue. > This would eventually result in a kernel crash (NULL ptr dereference). What backtrace did you see when it crashed? There have been a number of reports where sd_revalidate_disk is at the top of the backtrace and this sounds like it might be related. josh -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html