From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 03C56C47259 for ; Tue, 5 May 2020 16:58:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CD17C20836 for ; Tue, 5 May 2020 16:58:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588697935; bh=N18rhaJtm01k8g6a0UjT7Q6LzqEp+W4aYkEI1nt+QGM=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=WQ8bJ7fnGFz6wEYALjRBuE3mpc81fiB90dCjtviqVFLF6Njyb8dxBjLPx2uWVvL5R RAtEkeTm8tk1jagc1eX1TNRdt9UQLZKo07fyZV2YzajQ5t7FOI7eX2ZhItm/lNEHDY xqpZ3zcw/jl/bGAug2poEStN0/0SBUd0UsFP5lu8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730706AbgEEQ6z (ORCPT ); Tue, 5 May 2020 12:58:55 -0400 Received: from mail.kernel.org ([198.145.29.99]:38888 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730672AbgEEQ6t (ORCPT ); Tue, 5 May 2020 12:58:49 -0400 Received: from gmail.com (unknown [104.132.1.76]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id B49B120757; Tue, 5 May 2020 16:58:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588697928; bh=N18rhaJtm01k8g6a0UjT7Q6LzqEp+W4aYkEI1nt+QGM=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=MGVAziaxz2CPuV6fer1oeWX2KYKiEaAs3iXbuxTffNfh5rfa2+3lCDNDfJR97mRGz FR7XkyVbck8+3uHqPfXEA9DYmQ1TwPHGVfgOLtQD/FNDGlHK7UNxn86jwi3KrNKcaH bIefYvdqDROf14QqFG54fWlXC7ASGAUqAj+Gy+d4= Date: Tue, 5 May 2020 09:58:47 -0700 From: Eric Biggers To: Jaegeuk Kim Cc: linux-kernel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, kernel-team@android.com Subject: Re: [f2fs-dev] [PATCH] f2fs: get parent inode when recovering pino Message-ID: <20200505165847.GA98848@gmail.com> References: <20200505153139.201697-1-jaegeuk@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200505153139.201697-1-jaegeuk@kernel.org> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, May 05, 2020 at 08:31:39AM -0700, Jaegeuk Kim wrote: > We had to grab the inode before retrieving i_ino. > > Signed-off-by: Jaegeuk Kim > --- > fs/f2fs/file.c | 8 +++++++- > 1 file changed, 7 insertions(+), 1 deletion(-) > > diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c > index a0a4413d6083b..9d4c3e3503567 100644 > --- a/fs/f2fs/file.c > +++ b/fs/f2fs/file.c > @@ -168,6 +168,7 @@ static const struct vm_operations_struct f2fs_file_vm_ops = { > static int get_parent_ino(struct inode *inode, nid_t *pino) > { > struct dentry *dentry; > + struct inode *parent; > > inode = igrab(inode); > dentry = d_find_any_alias(inode); > @@ -175,8 +176,13 @@ static int get_parent_ino(struct inode *inode, nid_t *pino) > if (!dentry) > return 0; > > - *pino = parent_ino(dentry); > + parent = igrab(d_inode(dentry->d_parent)); > dput(dentry); > + if (!parent) > + return 0; > + > + *pino = parent->i_ino; > + iput(parent); > return 1; This doesn't appear to be necessary. parent_ino() is: spin_lock(&dentry->d_lock); res = dentry->d_parent->d_inode->i_ino; spin_unlock(&dentry->d_lock); Since dentry is locked and referenced, ->d_parent is stable and positive. In the encrypt+casefold patch I was reviewing, it's indeed necessary, but only because there was a check of inode->i_flags added outside the locked region. The following would be simpler: spin_lock(&dentry->d_lock); dir = dentry->d_parent->d_inode; *pino = dir->i_ino; needs_recovery = IS_ENCRYPTED(dir) && IS_CASEFOLDED(dir); spin_unlock(&dentry->d_lock); BTW, d_find_any_alias() is unnecessary too. This code should just be using file_dentry(file) from f2fs_do_sync_file(). - Eric