Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751737AbaJTMeT (ORCPT ); Mon, 20 Oct 2014 08:34:19 -0400 Received: from zeniv.linux.org.uk ([195.92.253.2]:54609 "EHLO ZenIV.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751194AbaJTMeS (ORCPT ); Mon, 20 Oct 2014 08:34:18 -0400 Date: Mon, 20 Oct 2014 13:34:15 +0100 From: Al Viro To: Richard Weinberger Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, OGAWA Hirofumi Subject: Re: [PATCH 1/2] fat: Fix d_splice_alias() return code checking Message-ID: <20141020123415.GN7996@ZenIV.linux.org.uk> References: <1413715184-30196-1-git-send-email-richard@nod.at> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1413715184-30196-1-git-send-email-richard@nod.at> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Oct 19, 2014 at 12:39:43PM +0200, Richard Weinberger wrote: > d_splice_alias() can return a valid dentry, NULL or an ERR_PTR. > Currently the code checks not for ERR_PTR. > Fix this by using IS_ERR_OR_NULL(). Why do we need to set ->d_time for non-NULL inode anyway? AFAICS, it's never checked for positive dentries, and the moment when positive dentry become negative is when we want to set it anyway. What am I missing here? Why not simply do this: diff --git a/fs/fat/namei_vfat.c b/fs/fat/namei_vfat.c index 6df8d3d..e2dc6bf 100644 --- a/fs/fat/namei_vfat.c +++ b/fs/fat/namei_vfat.c @@ -725,15 +725,14 @@ static struct dentry *vfat_lookup(struct inode *dir, struct dentry *dentry, inode = NULL; goto out; } - goto error; + inode = ERR_PTR(inode); + goto out; } inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos); brelse(sinfo.bh); - if (IS_ERR(inode)) { - err = PTR_ERR(inode); - goto error; - } + if (IS_ERR(inode)) + goto out; alias = d_find_alias(inode); if (alias && !vfat_d_anon_disconn(alias)) { @@ -754,16 +753,10 @@ static struct dentry *vfat_lookup(struct inode *dir, struct dentry *dentry, dput(alias); out: + if (!inode) + dentry->d_time = dir->i_version; mutex_unlock(&MSDOS_SB(sb)->s_lock); - dentry->d_time = dentry->d_parent->d_inode->i_version; - dentry = d_splice_alias(inode, dentry); - if (dentry) - dentry->d_time = dentry->d_parent->d_inode->i_version; - return dentry; - -error: - mutex_unlock(&MSDOS_SB(sb)->s_lock); - return ERR_PTR(err); + return d_splice_alias(inode, dentry); } static int vfat_create(struct inode *dir, struct dentry *dentry, umode_t mode, @@ -793,7 +786,6 @@ static int vfat_create(struct inode *dir, struct dentry *dentry, umode_t mode, inode->i_mtime = inode->i_atime = inode->i_ctime = ts; /* timestamp is already written, so mark_inode_dirty() is unneeded. */ - dentry->d_time = dentry->d_parent->d_inode->i_version; d_instantiate(dentry, inode); out: mutex_unlock(&MSDOS_SB(sb)->s_lock); @@ -824,6 +816,7 @@ static int vfat_rmdir(struct inode *dir, struct dentry *dentry) clear_nlink(inode); inode->i_mtime = inode->i_atime = CURRENT_TIME_SEC; fat_detach(inode); + dentry->d_time = dir->i_version; out: mutex_unlock(&MSDOS_SB(sb)->s_lock); @@ -849,6 +842,7 @@ static int vfat_unlink(struct inode *dir, struct dentry *dentry) clear_nlink(inode); inode->i_mtime = inode->i_atime = CURRENT_TIME_SEC; fat_detach(inode); + dentry->d_time = dir->i_version; out: mutex_unlock(&MSDOS_SB(sb)->s_lock); @@ -889,7 +883,6 @@ static int vfat_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) inode->i_mtime = inode->i_atime = inode->i_ctime = ts; /* timestamp is already written, so mark_inode_dirty() is unneeded. */ - dentry->d_time = dentry->d_parent->d_inode->i_version; d_instantiate(dentry, inode); mutex_unlock(&MSDOS_SB(sb)->s_lock); -- 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/