Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756071Ab3HaGLv (ORCPT ); Sat, 31 Aug 2013 02:11:51 -0400 Received: from mail-ve0-f181.google.com ([209.85.128.181]:62181 "EHLO mail-ve0-f181.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754512Ab3HaGLt (ORCPT ); Sat, 31 Aug 2013 02:11:49 -0400 MIME-Version: 1.0 In-Reply-To: <51F735AE.2050902@cn.fujitsu.com> References: <1374919965-11690-1-git-send-email-a3at.mail@gmail.com> <51F735AE.2050902@cn.fujitsu.com> Date: Sat, 31 Aug 2013 10:11:48 +0400 Message-ID: Subject: Re: [PATCH] btrfs: use list_for_each_entry_safe() when delete items From: Azat Khuzhin To: miaox@cn.fujitsu.com Cc: linux-btrfs@vger.kernel.org, chris.mason@fusionio.com, open list Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2248 Lines: 75 On Tue, Jul 30, 2013 at 7:40 AM, Miao Xie wrote: > On mon, 29 Jul 2013 11:48:32 +0400, Azat Khuzhin wrote: >> On Sat, Jul 27, 2013 at 2:12 PM, Azat Khuzhin wrote: >>> Replace list_for_each_entry() by list_for_each_entry_safe() in >>> __btrfs_close_devices() >>> >>> There is another place that delete items lock_stripe_add(), but there we >>> don't need safe version, because after deleting we exit from loop. >>> >>> Signed-off-by: Azat Khuzhin >>> --- >>> fs/btrfs/volumes.c | 4 ++-- >>> 1 file changed, 2 insertions(+), 2 deletions(-) >>> >>> diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c >>> index 78b8717..1d1b595 100644 >>> --- a/fs/btrfs/volumes.c >>> +++ b/fs/btrfs/volumes.c >>> @@ -616,13 +616,13 @@ static void free_device(struct rcu_head *head) >>> >>> static int __btrfs_close_devices(struct btrfs_fs_devices *fs_devices) >>> { >>> - struct btrfs_device *device; >>> + struct btrfs_device *device, *next; >>> >>> if (--fs_devices->opened > 0) >>> return 0; >>> >>> mutex_lock(&fs_devices->device_list_mutex); >>> - list_for_each_entry(device, &fs_devices->devices, dev_list) { >>> + list_for_each_entry_safe(device, next, &fs_devices->devices, dev_list) { >>> struct btrfs_device *new_device; >>> struct rcu_string *name; >> >> There is "kfree(device);" at the end of loop, maybe there must "goto >> again;" after it? >> (instead of this patch) Ugh. I was looking into another function! > > Your fix is right, we needn't search from the head once again. > > The other fix way is: > call_rcu(&device->rcu, free_device); > + device = new_device; > } > but from the viewpoint of the readability, this way is not so good. > > Reviewed-by: Miao Xie Thanks! Miao, should I resend patch with you reviewed-by? > >> >>> >>> -- >>> 1.7.10.4 >>> >> >> >> > -- Respectfully Azat Khuzhin -- 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/