Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933642AbdC3KfN (ORCPT ); Thu, 30 Mar 2017 06:35:13 -0400 Received: from mail-oi0-f68.google.com ([209.85.218.68]:34782 "EHLO mail-oi0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933347AbdC3KfI (ORCPT ); Thu, 30 Mar 2017 06:35:08 -0400 MIME-Version: 1.0 In-Reply-To: <4c7a176b-6132-7936-a04f-d4def5e56320@nod.at> References: <1490864181-2192-1-git-send-email-richard@nod.at> <4c7a176b-6132-7936-a04f-d4def5e56320@nod.at> From: Amir Goldstein Date: Thu, 30 Mar 2017 13:35:06 +0300 Message-ID: Subject: Re: [PATCH] ubifs: Fix O_TMPFILE corner case in ubifs_link() To: Richard Weinberger Cc: Adrian Hunter , linux-mtd@lists.infradead.org, linux-kernel , Artem Bityutskiy , "stable [v4.9]" , Ralph Sennhauser 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: 1472 Lines: 35 On Thu, Mar 30, 2017 at 1:23 PM, Richard Weinberger wrote: > Am 30.03.2017 um 11:49 schrieb Richard Weinberger: >> Am 30.03.2017 um 11:32 schrieb Adrian Hunter: >>>> diff --git a/fs/ubifs/dir.c b/fs/ubifs/dir.c >>>> index 0858213a4e63..0139155045fe 100644 >>>> --- a/fs/ubifs/dir.c >>>> +++ b/fs/ubifs/dir.c >>>> @@ -748,6 +748,11 @@ static int ubifs_link(struct dentry *old_dentry, struct inode *dir, >>>> goto out_fname; >>>> >>>> lock_2_inodes(dir, inode); >>>> + >>>> + /* Handle O_TMPFILE corner case, it is allowed to link a O_TMPFILE. */ >>>> + if (inode->i_nlink == 0) >>>> + ubifs_delete_orphan(c, inode->i_ino); >>> >>> Isn't there also a deletion inode in the journal? If the recovery sees that >>> won't it delete the file data? >> >> Yes, but ubifs_link() adds a new journal entry which revives the inode. >> This should cancel out the deletion, right? >> You know the UBIFS journal better than I do. :-) > > Reading deeper into the proved that I was wrong. > AFAIKT UBIFS' journal has currently no way to revive a deleted inode. > So, we have to think about a new solution. > Not that I know anything about ubifs, but why do you need the deleted inode record in the first place for an O_TMPFILE. vfs ensures you that you can only link back an O_TMPFILE, not a deleted inode. It does not appear to be the right thing to do to pass deletion=1 to ubifs_jnl_update(), but deletion=0 doesn't look right as well..