From: Alan Stern Subject: Re: Weird I/O errors with USB hard drive not remounting filesystem readonly Date: Mon, 23 Nov 2009 15:33:56 -0500 (EST) Message-ID: References: <20091123200605.GA19446@roll> Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Cc: Jan Kara , , , Jens Axboe , , To: tmhikaru@gmail.com Return-path: Received: from iolanthe.rowland.org ([192.131.102.54]:59361 "HELO iolanthe.rowland.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1755791AbZKWUdu (ORCPT ); Mon, 23 Nov 2009 15:33:50 -0500 In-Reply-To: <20091123200605.GA19446@roll> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Mon, 23 Nov 2009 tmhikaru@gmail.com wrote: > Uhh, this could be a problem. CONFIG_USB_MON=y is set in my .config BUT, > although I followed the directions and debugfs is mounted, > > root@roll:/home/tm# mount > /dev/root on / type ext4 (rw,relatime,barrier=1,data=ordered,data_err=abort) > proc on /proc type proc (rw) > sysfs on /sys type sysfs (rw) > usbfs on /proc/bus/usb type usbfs (rw) > none_debugs on /sys/kernel/debug type debugfs (rw) > > I receive this message when I test if usbmon's directory exists: > > root@roll:/home/tm# ls /sys/kernel/debug/usbmon > ls: cannot access /sys/kernel/debug/usbmon: No such file or directory > > According to the kernel documentation usbmon should be loaded already. Help? The documentation is slightly out of date. The usbmon directory has been moved down a level, to /sys/kernel/debug/usb/usbmon. Alan Stern