Return-Path: linux-nfs-owner@vger.kernel.org Received: from fieldses.org ([174.143.236.118]:33312 "EHLO fieldses.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751484AbaAPSvM (ORCPT ); Thu, 16 Jan 2014 13:51:12 -0500 Date: Thu, 16 Jan 2014 13:51:07 -0500 From: "J. Bruce Fields" To: Bob Peterson Cc: Steven Whitehouse , Al Viro , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-nfs@vger.kernel.org, Miklos Szeredi Subject: Re: [PATCH] dcache: fix d_splice_alias handling of aliases Message-ID: <20140116185107.GE16829@fieldses.org> References: <20140115151749.GF23999@fieldses.org> <20140116161015.GC16829@fieldses.org> <1389888942.2779.34.camel@menhir> <20140116164411.GD16829@fieldses.org> <1875464309.3327883.1389891247171.JavaMail.root@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <1875464309.3327883.1389891247171.JavaMail.root@redhat.com> Sender: linux-nfs-owner@vger.kernel.org List-ID: On Thu, Jan 16, 2014 at 11:54:07AM -0500, Bob Peterson wrote: > ----- Original Message ----- > | Something like this? > (snip) > | @@ -779,6 +782,11 @@ static struct dentry *__gfs2_lookup(struct inode *dir, > | struct dentry *dentry, > | } > | > | d = d_splice_alias(inode, dentry); > | + if (IS_ERR(d)) { > | + iput(inode); > | + gfs2_glock_dq_uninit(&gh); > | + return ERR_PTR(error); > > ---------------------------------^ > Shouldn't that be ERR_PTR(d)? Oops, yeah--well, actually just "d" I guess. This is what I've got for what it's worth. --b. commit 6fba5295019b52a03d76c9e9570952466051a7a6 Author: J. Bruce Fields Date: Thu Jan 16 11:44:53 2014 -0500 gfs2: revert "GFS2: d_splice_alias() can't return error" 0d0d110720d7960b77c03c9f2597faaff4b484ae asserts that "d_splice_alias() can't return error unless it was given an IS_ERR(inode)". That was true of the implementation of d_splice_alias, but this is really a problem with d_splice_alias: at a minimum it should be able to return -ELOOP in the case where inserting the given dentry would cause a directory loop. Signed-off-by: J. Bruce Fields diff --git a/fs/gfs2/inode.c b/fs/gfs2/inode.c index 7119504..3f44902 100644 --- a/fs/gfs2/inode.c +++ b/fs/gfs2/inode.c @@ -585,6 +585,9 @@ static int gfs2_create_inode(struct inode *dir, struct dentry *dentry, error = PTR_ERR(inode); if (!IS_ERR(inode)) { d = d_splice_alias(inode, dentry); + error = PTR_ERR(d); + if (IS_ERR(d)) + goto fail_gunlock; error = 0; if (file) { if (S_ISREG(inode->i_mode)) { @@ -779,6 +782,11 @@ static struct dentry *__gfs2_lookup(struct inode *dir, struct dentry *dentry, } d = d_splice_alias(inode, dentry); + if (IS_ERR(d)) { + iput(inode); + gfs2_glock_dq_uninit(&gh); + return d; + } if (file && S_ISREG(inode->i_mode)) error = finish_open(file, dentry, gfs2_open_common, opened);