Return-Path: linux-nfs-owner@vger.kernel.org Received: from fieldses.org ([174.143.236.118]:57285 "EHLO fieldses.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755187AbaDGUvc (ORCPT ); Mon, 7 Apr 2014 16:51:32 -0400 Date: Mon, 7 Apr 2014 16:51:21 -0400 To: Sage Weil Cc: Viro Alexander , "Yan, Zheng" , Trond Myklebust , David Howells , linux-fsdevel@vger.kernel.org, linux-nfs@vger.kernel.org, ceph-devel@vger.kernel.org Subject: Re: [PATCH][RESEND] vfs: Make __d_materialise_dentry() set the materialised dentry name correctly Message-ID: <20140407205121.GA4426@fieldses.org> References: <1394115376-17109-1-git-send-email-zheng.z.yan@intel.com> <6487FCC2-FB5C-4A32-94EF-5D3352A39781@primarydata.com> <53392EDA.7000904@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: From: "J. Bruce Fields" Sender: linux-nfs-owner@vger.kernel.org List-ID: On Mon, Apr 07, 2014 at 06:56:28AM -0700, Sage Weil wrote: > Hi Al, > > Can this go to Linus via your tree? I believe this has been fixed by da1ce0670c14d8380e423a3239e562a1dc15fa9e "vfs: add cross-rename". Though probably the patch should still go in, possibly with a changelog update. We want it for stable kernels if nothing else. --b. > > Thanks! > sage > > > On Mon, 31 Mar 2014, Yan, Zheng wrote: > > > Hi Al, > > > > Could you include this in 3.15 > > > > Regards > > Yan, Zheng > > > > On 03/06/2014 10:35 PM, Trond Myklebust wrote: > > > > > > On Mar 6, 2014, at 9:16, Yan, Zheng wrote: > > > > > >> From: David Howells > > >> > > >> Make __d_materialise_dentry() set the materialised dentry name correctly by > > >> flipping the arguments to switch_names(). > > >> > > >> switch_names() is lazy: if both names are internal to their dentries, it'll > > >> overwrite that of the first dentry with that of the second, and won't update > > >> that of the second. > > >> > > >> In the case of __d_materialise_dentry(), the second is an already extant > > >> anonymous dentry that we want to insert into the tree in place of the dentry we > > >> just looked up[*]. However, the dentry we just looked up carries the name we > > >> actually want to use. > > >> > > >> [*] This is used by NFS to join a mount of a subtree into a mount of a tree > > >> nearer the root when the two meet, where both mounts share a superblock and > > >> thus a set of dentries. > > >> > > >> Signed-off-by: David Howells > > >> --- > > >> fs/dcache.c | 2 +- > > >> 1 file changed, 1 insertion(+), 1 deletion(-) > > >> > > >> diff --git a/fs/dcache.c b/fs/dcache.c > > >> index 265e0ce..ff779d4 100644 > > >> --- a/fs/dcache.c > > >> +++ b/fs/dcache.c > > >> @@ -2698,7 +2698,7 @@ static void __d_materialise_dentry(struct dentry *dentry, struct dentry *anon) > > >> > > >> dparent = dentry->d_parent; > > >> > > >> - switch_names(dentry, anon); > > >> + switch_names(anon, dentry); > > >> swap(dentry->d_name.hash, anon->d_name.hash); > > >> > > >> dentry->d_parent = dentry; > > > > > > Well spotted... > > > > > > We ought to better document the fact that ?switch_names? is asymmetrical. Perhaps change it to ?update_target_name?, and then switch the argument names so that the ?target? really is the thing that gets updated? > > > > > > _________________________________ > > > Trond Myklebust > > > Linux NFS client maintainer, PrimaryData > > > trond.myklebust@primarydata.com > > > > > > > -- > > To unsubscribe from this list: send the line "unsubscribe ceph-devel" in > > the body of a message to majordomo@vger.kernel.org > > More majordomo info at http://vger.kernel.org/majordomo-info.html > > > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html