Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Wed, 5 Feb 2003 11:40:06 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Wed, 5 Feb 2003 11:40:06 -0500 Received: from caramon.arm.linux.org.uk ([212.18.232.186]:23823 "EHLO caramon.arm.linux.org.uk") by vger.kernel.org with ESMTP id ; Wed, 5 Feb 2003 11:40:05 -0500 Date: Wed, 5 Feb 2003 16:49:37 +0000 From: Russell King To: Rik van Riel , Andrew Morton , torvalds@transmeta.com, linux-kernel@vger.kernel.org, tytso@thunk.org, rddunlap@osdl.org Subject: Re: [PATCH][RESEND 3] disassociate_ctty SMP fix Message-ID: <20030205164937.C28758@flint.arm.linux.org.uk> Mail-Followup-To: Rik van Riel , Andrew Morton , torvalds@transmeta.com, linux-kernel@vger.kernel.org, tytso@thunk.org, rddunlap@osdl.org References:

<20030204175109.57bbfc51.akpm@digeo.com> <20030205095114.A25479@flint.arm.linux.org.uk> <20030205145126.A28758@flint.arm.linux.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5.1i In-Reply-To: <20030205145126.A28758@flint.arm.linux.org.uk>; from rmk@arm.linux.org.uk on Wed, Feb 05, 2003 at 02:51:26PM +0000 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1416 Lines: 34 Ok, here's my proposed fix, which appears to work with preempt. I haven't tested on non-preempt, nor (obviously since its from me) SMP. However, I forsee no problems caused by this change. release_dev() sets filp->private_data to NULL when the tty layer has done with the file descriptor. However, it remains on the tty_files list until __fput completes. --- orig/drivers/char/tty_io.c Fri Jan 17 10:39:10 2003 +++ linux/drivers/char/tty_io.c Wed Feb 5 16:38:23 2003 @@ -442,6 +442,13 @@ file_list_lock(); for (l = tty->tty_files.next; l != &tty->tty_files; l = l->next) { struct file * filp = list_entry(l, struct file, f_list); + /* + * If this file descriptor has been closed, ignore it; it + * will be going away shortly. (We don't test filp->f_count + * for zero since that could open another race.) --rmk + */ + if (filp->private_data == NULL) + continue; if (IS_CONSOLE_DEV(filp->f_dentry->d_inode->i_rdev) || IS_SYSCONS_DEV(filp->f_dentry->d_inode->i_rdev)) { cons_filp = filp; -- Russell King (rmk@arm.linux.org.uk) The developer of ARM Linux http://www.arm.linux.org.uk/personal/aboutme.html - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/