From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964920AbWLTGkb (ORCPT ); Wed, 20 Dec 2006 01:40:31 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S964922AbWLTGkb (ORCPT ); Wed, 20 Dec 2006 01:40:31 -0500 Received: from mail1.sea5.speakeasy.net ([69.17.117.3]:47449 "EHLO mail1.sea5.speakeasy.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964920AbWLTGka (ORCPT ); Wed, 20 Dec 2006 01:40:30 -0500 X-Greylist: delayed 400 seconds by postgrey-1.27 at vger.kernel.org; Wed, 20 Dec 2006 01:40:30 EST Subject: [PATCH] fdtable: Provide free_fdtable() wrapper. From: Vadim Lobanov To: akpm@osdl.org, hch@lst.de, linux-kernel@vger.kernel.org Content-Type: text/plain Date: Tue, 19 Dec 2006 22:33:45 -0800 Message-Id: <1166596425.20073.2.camel@localhost.localdomain> Mime-Version: 1.0 X-Mailer: Evolution 2.8.2.1 (2.8.2.1-2.fc6) Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hi, Christoph Hellwig has expressed concerns that the recent fdtable changes expose the details of the RCU methodology used to release no-longer-used fdtable structures to the rest of the kernel. The trivial patch below addresses these concerns by introducing the appropriate free_fdtable() calls, which simply wrap the release RCU usage. Since free_fdtable() is a one-liner, it makes sense to promote it to an inline helper. Please apply. Signed-off-by: Vadim Lobanov diff -pru old/fs/file.c new/fs/file.c --- old/fs/file.c 2006-12-19 19:54:23.000000000 -0800 +++ new/fs/file.c 2006-12-19 20:04:02.000000000 -0800 @@ -206,7 +206,7 @@ static int expand_fdtable(struct files_s copy_fdtable(new_fdt, cur_fdt); rcu_assign_pointer(files->fdt, new_fdt); if (cur_fdt->max_fds > NR_OPEN_DEFAULT) - call_rcu(&cur_fdt->rcu, free_fdtable_rcu); + free_fdtable(cur_fdt); } else { /* Somebody else expanded, so undo our attempt */ free_fdarr(new_fdt); diff -pru old/include/linux/file.h new/include/linux/file.h --- old/include/linux/file.h 2006-12-19 19:54:25.000000000 -0800 +++ new/include/linux/file.h 2006-12-19 20:03:19.000000000 -0800 @@ -80,6 +80,11 @@ extern int expand_files(struct files_str extern void free_fdtable_rcu(struct rcu_head *rcu); extern void __init files_defer_init(void); +static inline void free_fdtable(struct fdtable *fdt) +{ + call_rcu(&fdt->rcu, free_fdtable_rcu); +} + static inline struct file * fcheck_files(struct files_struct *files, unsigned int fd) { struct file * file = NULL; diff -pru old/kernel/exit.c new/kernel/exit.c --- old/kernel/exit.c 2006-12-19 19:54:52.000000000 -0800 +++ new/kernel/exit.c 2006-12-19 20:04:20.000000000 -0800 @@ -466,7 +466,7 @@ void fastcall put_files_struct(struct fi fdt = files_fdtable(files); if (fdt != &files->fdtab) kmem_cache_free(files_cachep, files); - call_rcu(&fdt->rcu, free_fdtable_rcu); + free_fdtable(fdt); } }