Return-Path: linux-nfs-owner@vger.kernel.org Received: from fieldses.org ([174.143.236.118]:59586 "EHLO fieldses.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752502AbaAQSEq (ORCPT ); Fri, 17 Jan 2014 13:04:46 -0500 Date: Fri, 17 Jan 2014 13:04:41 -0500 From: "J. Bruce Fields" To: Steven Whitehouse Cc: Bob Peterson , 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: <20140117180441.GB26636@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> <20140116185107.GE16829@fieldses.org> <1389953070.2734.17.camel@menhir> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <1389953070.2734.17.camel@menhir> Sender: linux-nfs-owner@vger.kernel.org List-ID: On Fri, Jan 17, 2014 at 10:04:30AM +0000, Steven Whitehouse wrote: > Hi, > > On Thu, 2014-01-16 at 13:51 -0500, J. Bruce Fields wrote: > > 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. > > > > I think the patch looks ok to me. Did you give it a spin to test it? Sure, just mkfs.gfs2 -p lock_nolock /dev/vdb mount /dev/vdb /mnt/ cd cthon NFSTESTDIR=/mnt/TMP ./runtests -a -f Which doesn't test much of anything (we'd need to inject artificial errors for now to test the error paths), but at least it doesn't blow up in some obvious way.... > If so then I will put it in the GFS2 -nmw tree, Thanks! --b. > > Steve. > > > 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); > > > >