Re: [PATCH v2 10/13] ceph: allow idmapped setattr inode op

From: Aleksandr Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com>
To: Christian Brauner <brauner@kernel.org>
Cc: Xiubo Li <xiubli@redhat.com>,
	stgraber@ubuntu.com, linux-fsdevel@vger.kernel.org,
	Jeff Layton <jlayton@kernel.org>,
	Ilya Dryomov <idryomov@gmail.com>,
	ceph-devel@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 10/13] ceph: allow idmapped setattr inode op
Date: Fri, 2 Jun 2023 15:15:12 +0200	[thread overview]
Message-ID: <CAEivzxfOgiQjXob+J1S5MsBFJjDGX_hApD_xR1s7q-S9eQh_bw@mail.gmail.com> (raw)
In-Reply-To: <20230602-behoben-tauglich-b6ecd903f2a9@brauner>

On Fri, Jun 2, 2023 at 3:08 PM Christian Brauner <brauner@kernel.org> wrote:
>
> On Fri, Jun 02, 2023 at 03:05:50PM +0200, Aleksandr Mikhalitsyn wrote:
> > On Fri, Jun 2, 2023 at 2:54 PM Christian Brauner <brauner@kernel.org> wrote:
> > >
> > > On Fri, Jun 02, 2023 at 02:45:30PM +0200, Aleksandr Mikhalitsyn wrote:
> > > > On Fri, Jun 2, 2023 at 3:30 AM Xiubo Li <xiubli@redhat.com> wrote:
> > > > >
> > > > >
> > > > > On 5/24/23 23:33, Alexander Mikhalitsyn wrote:
> > > > > > From: Christian Brauner <christian.brauner@ubuntu.com>
> > > > > >
> > > > > > Enable __ceph_setattr() to handle idmapped mounts. This is just a matter
> > > > > > of passing down the mount's idmapping.
> > > > > >
> > > > > > Cc: Jeff Layton <jlayton@kernel.org>
> > > > > > Cc: Ilya Dryomov <idryomov@gmail.com>
> > > > > > Cc: ceph-devel@vger.kernel.org
> > > > > > Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
> > > > > > Signed-off-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com>
> > > > > > ---
> > > > > >   fs/ceph/inode.c | 11 +++++++++--
> > > > > >   1 file changed, 9 insertions(+), 2 deletions(-)
> > > > > >
> > > > > > diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c
> > > > > > index 37e1cbfc7c89..f1f934439be0 100644
> > > > > > --- a/fs/ceph/inode.c
> > > > > > +++ b/fs/ceph/inode.c
> > > > > > @@ -2050,6 +2050,13 @@ int __ceph_setattr(struct inode *inode, struct iattr *attr)
> > > > > >
> > > > > >       dout("setattr %p issued %s\n", inode, ceph_cap_string(issued));
> > > > > >
> > > > > > +     /*
> > > > > > +      * The attr->ia_{g,u}id members contain the target {g,u}id we're
> > >
> > > This is now obsolete... In earlier imlementations attr->ia_{g,u}id was
> > > used and contained the filesystem wide value, not the idmapped mount
> > > value.
> > >
> > > However, this was misleading and we changed that in commit b27c82e12965
> > > ("attr: port attribute changes to new types") and introduced dedicated
> > > new types into struct iattr->ia_vfs{g,u}id. So the you need to use
> > > attr->ia_vfs{g,u}id as documented in include/linux/fs.h and you need to
> > > transform them into filesystem wide values and then to raw values you
> > > send over the wire.
> > >
> > > Alex should be able to figure this out though.
> >
> > Hi Christian,
> >
> > Thanks for pointing this out. Unfortunately I wasn't able to notice
> > that. I'll take a look closer and fix that.
>
> Just to clarify: I wasn't trying to imply that you should've figured
> this out on your own. I was just trying to say that you should be able
> figure out the exact details how to implement this in ceph after I told
> you about the attr->ia_vfs{g,u}id change.

No problem, I've got your idea the same as you explained it ;-)
I'll rework that place and I will recheck that we pass xfstests after that.