From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S264928AbTLFBlV (ORCPT ); Fri, 5 Dec 2003 20:41:21 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S264927AbTLFBk1 (ORCPT ); Fri, 5 Dec 2003 20:40:27 -0500 Received: from mail.kroah.org ([65.200.24.183]:44769 "EHLO perch.kroah.org") by vger.kernel.org with ESMTP id S264920AbTLFBkC (ORCPT ); Fri, 5 Dec 2003 20:40:02 -0500 Date: Fri, 5 Dec 2003 17:38:44 -0800 From: Greg KH To: Mike Gorse Cc: Maneesh Soni , linux-kernel@vger.kernel.org, mochel@digitalimplant.org Subject: Re: Oops w/sysfs when closing a disconnected usb serial device Message-ID: <20031206013844.GA16844@kroah.com> References: <20031201093804.GA6918@in.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.4.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Dec 01, 2003 at 06:55:38PM -0500, Mike Gorse wrote: > Hi Maneesh, > > On Mon, 1 Dec 2003, Maneesh Soni wrote: > > > IMO d->d_inode is not expected to be NULL at this point. The only > > place it can become NULL is in d_delete(d) call, but as the dentry ref. > > count will be atleast 2, even this will not make d_inode NULL and it should > > only unhash the dentry. Probably it will become more clear if you post > > the oops message. > > > It is trying to delete a directory which is gone already. I'll post the > oops below. > > > Mean while, I think kobject_del should not remove corresponding sysfs directory > > until all the other references to kobject has gone. There can be references > > taken in sysfs_open_file() from user space. The following patch moves the > > sysfs_remove_dir() call, to kobject_cleanup() and I think it may solve your > > problem also. It will be nice if you can test it. > > > I wish your patch solved things in itself, but, without the added sysfs > check, I now get a new oops when disconnecting the device, even if no > applications are using it. Try the patch below. With your sysfs patch I don't get any oopses anymore. I still need to beat on this patch a lot more before I think it solves all of the current issues. Can you let me know if it works for you or not? thanks, greg k-h diff -Nru a/drivers/usb/serial/usb-serial.c b/drivers/usb/serial/usb-serial.c --- a/drivers/usb/serial/usb-serial.c Fri Dec 5 17:37:16 2003 +++ b/drivers/usb/serial/usb-serial.c Fri Dec 5 17:37:16 2003 @@ -493,12 +493,15 @@ return retval; } -static void __serial_close(struct usb_serial_port *port, struct file *filp) +static void serial_close(struct tty_struct *tty, struct file * filp) { - if (!port->open_count) { - dbg ("%s - port not opened", __FUNCTION__); + struct usb_serial_port *port = (struct usb_serial_port *) tty->driver_data; + struct usb_serial *serial = get_usb_serial (port, __FUNCTION__); + + if (!serial) return; - } + + dbg("%s - port %d", __FUNCTION__, port->number); --port->open_count; if (port->open_count <= 0) { @@ -506,30 +509,18 @@ * port is being closed by the last owner */ port->serial->type->close(port, filp); port->open_count = 0; + + if (port->tty) { + if (port->tty->driver_data) + port->tty->driver_data = NULL; + port->tty = NULL; + } } module_put(port->serial->type->owner); kobject_put(&port->serial->kobj); } -static void serial_close(struct tty_struct *tty, struct file * filp) -{ - struct usb_serial_port *port = (struct usb_serial_port *) tty->driver_data; - struct usb_serial *serial = get_usb_serial (port, __FUNCTION__); - - if (!serial) - return; - - dbg("%s - port %d", __FUNCTION__, port->number); - - /* if disconnect beat us to the punch here, there's nothing to do */ - if (tty && tty->driver_data) { - __serial_close(port, filp); - tty->driver_data = NULL; - } - port->tty = NULL; -} - static int serial_write (struct tty_struct * tty, int from_user, const unsigned char *buf, int count) { struct usb_serial_port *port = (struct usb_serial_port *) tty->driver_data; @@ -848,19 +839,6 @@ dbg ("%s - %s", __FUNCTION__, kobj->name); serial = to_usb_serial(kobj); - - /* fail all future close/read/write/ioctl/etc calls */ - for (i = 0; i < serial->num_ports; ++i) { - port = serial->port[i]; - if (port->tty != NULL) { - port->tty->driver_data = NULL; - while (port->open_count > 0) { - __serial_close(port, NULL); - } - port->tty = NULL; - } - } - serial_shutdown (serial); /* return the minor range that this device had */ @@ -1242,7 +1220,7 @@ /* register all of the individual ports with the driver core */ for (i = 0; i < num_ports; ++i) { port = serial->port[i]; - port->dev.parent = &serial->dev->dev; + port->dev.parent = &interface->dev; port->dev.driver = NULL; port->dev.bus = &usb_serial_bus_type; port->dev.release = &port_release;