From mboxrd@z Thu Jan 1 00:00:00 1970 From: Amir Goldstein Subject: Re: [PATCH 3/7] ovl: Copy up only metadata during copy up where it makes sense Date: Mon, 2 Oct 2017 22:21:05 +0300 Message-ID: References: <1506951605-31440-1-git-send-email-vgoyal@redhat.com> <1506951605-31440-4-git-send-email-vgoyal@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Return-path: Received: from mail-qt0-f194.google.com ([209.85.216.194]:38683 "EHLO mail-qt0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751357AbdJBTVH (ORCPT ); Mon, 2 Oct 2017 15:21:07 -0400 Received: by mail-qt0-f194.google.com with SMTP id o3so191759qte.5 for ; Mon, 02 Oct 2017 12:21:06 -0700 (PDT) In-Reply-To: <1506951605-31440-4-git-send-email-vgoyal@redhat.com> Sender: linux-unionfs-owner@vger.kernel.org List-Id: linux-unionfs@vger.kernel.org To: Vivek Goyal Cc: overlayfs , Miklos Szeredi On Mon, Oct 2, 2017 at 4:40 PM, Vivek Goyal wrote: > If it makes sense to copy up only metadata during copy up, do it. This > is done for regular files which are not opened for WRITE and have origin > being saved. > > Signed-off-by: Vivek Goyal > --- > fs/overlayfs/copy_up.c | 27 +++++++++++++++++++-------- > 1 file changed, 19 insertions(+), 8 deletions(-) > > diff --git a/fs/overlayfs/copy_up.c b/fs/overlayfs/copy_up.c > index cdc4d79a1249..b2d9ed81e9ff 100644 > --- a/fs/overlayfs/copy_up.c > +++ b/fs/overlayfs/copy_up.c > @@ -306,11 +306,8 @@ static int ovl_set_origin(struct dentry *dentry, struct dentry *lower, > return PTR_ERR(fh); > } > > - /* > - * Do not fail when upper doesn't support xattrs. > - */ > err = ovl_check_setxattr(dentry, upper, OVL_XATTR_ORIGIN, fh, > - fh ? fh->len : 0, 0); > + fh ? fh->len : 0, -EOPNOTSUPP); > kfree(fh); > > return err; > @@ -328,6 +325,7 @@ struct ovl_copy_up_ctx { > struct dentry *workdir; > bool tmpfile; > bool origin; > + bool metadata_only; > }; > > static int ovl_link_up(struct ovl_copy_up_ctx *c) > @@ -464,11 +462,15 @@ static int ovl_copy_up_inode(struct ovl_copy_up_ctx *c, struct dentry *temp) > */ > if (c->origin) { > err = ovl_set_origin(c->dentry, c->lowerpath.dentry, temp); > - if (err) > - return err; > + if (err) { > + if (err != -EOPNOTSUPP) > + return err; > + /* Upper does not support xattr. Copy up data as well */ > + c->metadata_only = false; > + } > } > > - if (S_ISREG(c->stat.mode)) { > + if (S_ISREG(c->stat.mode) && !c->metadata_only) { > struct path upperpath; > I would set the meta inode size here. see: https://github.com/amir73il/linux/commits/ovl-rocopyup > ovl_path_upper(c->dentry, &upperpath); > @@ -596,6 +598,7 @@ static int ovl_copy_up_one(struct dentry *parent, struct dentry *dentry, > .dentry = dentry, > .workdir = ovl_workdir(dentry), > .origin = true, > + .metadata_only = true, > }; > > if (WARN_ON(!ctx.workdir)) > @@ -616,9 +619,17 @@ static int ovl_copy_up_one(struct dentry *parent, struct dentry *dentry, > if (err) > return err; > > + if (!S_ISREG(ctx.stat.mode)) > + ctx.metadata_only = false; > + > /* maybe truncate regular file. this has no effect on dirs */ > - if (flags & O_TRUNC) > + if (flags & O_TRUNC) { > ctx.stat.size = 0; > + ctx.metadata_only = false; > + } > + > + if (flags & (OPEN_FMODE(flags) & FMODE_WRITE)) > + ctx.metadata_only = false; > > if (S_ISLNK(ctx.stat.mode)) { > ctx.link = vfs_get_link(ctx.lowerpath.dentry, &done); > -- > 2.13.5 >