From: Christian Brauner <brauner@kernel.org>
To: Christoph Hellwig <hch@lst.de>
Cc: linux-fsdevel@vger.kernel.org, Al Viro <viro@zeniv.linux.org.uk>,
Seth Forshee <sforshee@kernel.org>,
linux-erofs@lists.ozlabs.org, Jan Kara <jack@suse.com>,
linux-ext4@vger.kernel.org,
linux-f2fs-devel@lists.sourceforge.net,
linux-mtd@lists.infradead.org, ocfs2-devel@oss.oracle.com,
reiserfs-devel@vger.kernel.org
Subject: Re: [PATCH 00/12] acl: remove remaining posix acl handlers
Date: Mon, 30 Jan 2023 11:23:22 +0100 [thread overview]
Message-ID: <20230130102322.kkq5u72skrmykilh@wittgenstein> (raw)
In-Reply-To: <20230130091615.GB5178@lst.de>
On Mon, Jan 30, 2023 at 10:16:15AM +0100, Christoph Hellwig wrote:
> On Mon, Jan 30, 2023 at 10:10:52AM +0100, Christian Brauner wrote:
> > However, a few filesystems still rely on the ->list() method of the
> > generix POSIX ACL xattr handlers in their ->listxattr() inode operation.
> > This is a very limited set of filesystems. For most of them there is no
> > dependence on the generic POSIX ACL xattr handler in any way.
> >
> > In addition, during inode initalization in inode_init_always() the
> > registered xattr handlers in sb->s_xattr are used to raise IOP_XATTR in
> > inode->i_opflags.
> >
> > With the incoming removal of the legacy POSIX ACL handlers it is at
> > least possible for a filesystem to only implement POSIX ACLs but no
> > other xattrs. If that were to happen we would miss to raise IOP_XATTR
> > because sb->s_xattr would be NULL. While there currently is no such
> > filesystem we should still make sure that this just works should it ever
> > happen in the future.
>
> Now the real questions is: do we care? Once Posix ACLs use an
> entirely separate path, nothing should rely on IOP_XATTR for them.
> So instead I think we're better off auditing all users of IOP_XATTR
> and making sure that nothing relies on them for ACLs, as we've very
> much split the VFS concept of ACLs from that from xattrs otherwise.
I had a patch like that but some filesystems create inodes that
explicitly remove IOP_XATTR to prevent any xattrs from being set on
specific inodes. I remember this for at least reiserfs and btrfs.
So we would probably need IOP_NOACL that can be raised by a filesystem
to explicitly opt out of them for specific inodes. That's probably fine
and avoids having to introduce something like SB_I_XATTR.
prev parent reply other threads:[~2023-01-30 10:23 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-01-25 11:28 [PATCH 00/12] acl: remove remaining posix acl handlers Christian Brauner
2023-01-25 11:28 ` [PATCH 11/12] reiserfs: drop " Christian Brauner
2023-01-30 9:10 ` [PATCH 00/12] acl: remove remaining " Christian Brauner
2023-01-30 9:16 ` Christoph Hellwig
2023-01-30 10:23 ` Christian Brauner [this message]
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