From: Dave Chinner <david@fromorbit.com>
To: "Darrick J. Wong" <darrick.wong@oracle.com>
Cc: Amir Goldstein <amir73il@gmail.com>,
linux-fsdevel <linux-fsdevel@vger.kernel.org>,
linux-xfs <linux-xfs@vger.kernel.org>,
Olga Kornievskaia <olga.kornievskaia@gmail.com>,
Linux NFS Mailing List <linux-nfs@vger.kernel.org>,
overlayfs <linux-unionfs@vger.kernel.org>,
ceph-devel@vger.kernel.org, linux-cifs@vger.kernel.org
Subject: Re: [PATCH 08/11] vfs: push EXDEV check down into ->remap_file_range
Date: Tue, 4 Dec 2018 10:37:14 +1100 [thread overview]
Message-ID: <20181203233714.GL6311@dastard> (raw)
In-Reply-To: <20181203191130.GD24487@magnolia>
On Mon, Dec 03, 2018 at 11:11:30AM -0800, Darrick J. Wong wrote:
> On Mon, Dec 03, 2018 at 01:04:07PM +0200, Amir Goldstein wrote:
> > On Mon, Dec 3, 2018 at 10:34 AM Dave Chinner <david@fromorbit.com> wrote:
> > >
> > > From: Dave Chinner <dchinner@redhat.com>
> > >
> > > before we can enable cross-device copies into copy_file_range(),
> > > we have to ensure that ->remap_file_range() implemenations will
> > > correctly reject attempts to do cross filesystem clones. Currently
> >
> > But you only fixed remap_file_range() implemenations of xfs and ocfs2...
> >
> > > these checks are done above calls to ->remap_file_range(), but
> > > we need to drive them inwards so that we get EXDEV protection for all
> > > callers of ->remap_file_range().
> > >
> > > Signed-off-by: Dave Chinner <dchinner@redhat.com>
> > > ---
> > > fs/read_write.c | 21 +++++++++++++--------
> > > 1 file changed, 13 insertions(+), 8 deletions(-)
> > >
> > > diff --git a/fs/read_write.c b/fs/read_write.c
> > > index 3288db1d5f21..174cf92eea1d 100644
> > > --- a/fs/read_write.c
> > > +++ b/fs/read_write.c
> > > @@ -1909,6 +1909,19 @@ int generic_remap_file_range_prep(struct file *file_in, loff_t pos_in,
> > > bool same_inode = (inode_in == inode_out);
> > > int ret;
> > >
> > > + /*
> > > + * FICLONE/FICLONERANGE ioctls enforce that src and dest files are on
> > > + * the same mount. Practically, they only need to be on the same file
> > > + * system. We check this here rather than at the ioctl layers because
> > > + * this is effectively a limitation of the fielsystem implementations,
> > > + * not so much the API itself. Further, ->remap_file_range() can be
> > > + * called from syscalls that don't have cross device copy restrictions
> > > + * (such as copy_file_range()) and so we need to catch them before we
> > > + * do any damage.
> > > + */
> > > + if (inode_in->i_sb != inode_out->i_sb)
> > > + return -EXDEV;
> > > +
> > > /* Don't touch certain kinds of inodes */
> > > if (IS_IMMUTABLE(inode_out))
> > > return -EPERM;
> > > @@ -2013,14 +2026,6 @@ loff_t do_clone_file_range(struct file *file_in, loff_t pos_in,
> > > if (!S_ISREG(inode_in->i_mode) || !S_ISREG(inode_out->i_mode))
> > > return -EINVAL;
> > >
> > > - /*
> > > - * FICLONE/FICLONERANGE ioctls enforce that src and dest files are on
> > > - * the same mount. Practically, they only need to be on the same file
> > > - * system.
> > > - */
> > > - if (inode_in->i_sb != inode_out->i_sb)
> > > - return -EXDEV;
> > > -
> >
>
> I think this is sort of backwards -- the checks should stay in
> do_clone_file_range, and vfs_copy_file_range should be calling that
> instead of directly calling ->remap_range():
>
> vfs_copy_file_range()
> {
> file_start_write(...);
> ret = do_clone_file_range(...);
> if (ret > 0)
> return ret;
> ret = do_copy_file_range(...);
> file_end_write(...);
> return ret;
> }
I'm already confused by the way we weave in and out of "vfs_/do_*"
functions, and this just makes it worse.
Just what the hell is supposed to be in a "vfs_" prefixed function,
and why the hell is it considered a "vfs" level function if we then
export it's internal functions for individual filesystems to use?
Cheers,
Dave.
--
Dave Chinner
david@fromorbit.com
next prev parent reply other threads:[~2018-12-03 23:40 UTC|newest]
Thread overview: 83+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-12-03 8:34 [PATCH 0/11] fs: fixes for major copy_file_range() issues Dave Chinner
2018-12-03 8:34 ` [PATCH 01/11] vfs: copy_file_range source range over EOF should fail Dave Chinner
2018-12-03 12:46 ` Amir Goldstein
2018-12-04 15:13 ` Christoph Hellwig
2018-12-04 21:29 ` Dave Chinner
2018-12-04 21:47 ` Olga Kornievskaia
2018-12-04 22:31 ` Dave Chinner
2018-12-05 16:51 ` J. Bruce Fields
2019-05-20 9:10 ` Amir Goldstein
2019-05-20 13:12 ` Olga Kornievskaia
2019-05-20 13:36 ` Amir Goldstein
2019-05-20 13:58 ` Olga Kornievskaia
2019-05-20 14:02 ` Amir Goldstein
2018-12-05 14:12 ` Christoph Hellwig
2018-12-05 21:08 ` Dave Chinner
2018-12-05 21:30 ` Christoph Hellwig
2018-12-03 8:34 ` [PATCH 02/11] vfs: introduce generic_copy_file_range() Dave Chinner
2018-12-03 10:03 ` Amir Goldstein
2018-12-03 23:00 ` Dave Chinner
2018-12-04 15:14 ` Christoph Hellwig
2018-12-03 8:34 ` [PATCH 03/11] vfs: no fallback for ->copy_file_range Dave Chinner
2018-12-03 10:22 ` Amir Goldstein
2018-12-03 23:02 ` Dave Chinner
2018-12-06 4:16 ` Amir Goldstein
2018-12-06 21:30 ` Dave Chinner
2018-12-07 5:38 ` Amir Goldstein
2018-12-03 18:23 ` Anna Schumaker
2018-12-04 15:16 ` Christoph Hellwig
2018-12-03 8:34 ` [PATCH 04/11] vfs: add missing checks to copy_file_range Dave Chinner
2018-12-03 12:42 ` Amir Goldstein
2018-12-03 19:04 ` Darrick J. Wong
2018-12-03 21:33 ` Olga Kornievskaia
2018-12-03 23:04 ` Dave Chinner
2018-12-04 15:18 ` Christoph Hellwig
2018-12-12 11:31 ` Luis Henriques
2018-12-12 16:42 ` Darrick J. Wong
2018-12-12 18:55 ` Olga Kornievskaia
2018-12-12 19:42 ` Matthew Wilcox
2018-12-12 20:22 ` Olga Kornievskaia
2018-12-13 10:29 ` Luis Henriques
2018-12-03 8:34 ` [PATCH 05/11] vfs: use inode_permission in copy_file_range() Dave Chinner
2018-12-03 12:47 ` Amir Goldstein
2018-12-03 18:18 ` Darrick J. Wong
2018-12-03 23:55 ` Dave Chinner
2018-12-05 17:28 ` J. Bruce Fields
2018-12-03 18:53 ` Eric Biggers
2018-12-04 15:19 ` Christoph Hellwig
2018-12-03 8:34 ` [PATCH 06/11] vfs: copy_file_range needs to strip setuid bits Dave Chinner
2018-12-03 12:51 ` Amir Goldstein
2018-12-04 15:21 ` Christoph Hellwig
2018-12-03 8:34 ` [PATCH 07/11] vfs: copy_file_range should update file timestamps Dave Chinner
2018-12-03 10:47 ` Amir Goldstein
2018-12-03 17:33 ` Olga Kornievskaia
2018-12-03 18:22 ` Darrick J. Wong
2018-12-03 23:19 ` Dave Chinner
2018-12-04 15:24 ` Christoph Hellwig
2018-12-03 8:34 ` [PATCH 08/11] vfs: push EXDEV check down into ->remap_file_range Dave Chinner
2018-12-03 11:04 ` Amir Goldstein
2018-12-03 19:11 ` Darrick J. Wong
2018-12-03 23:37 ` Dave Chinner [this message]
2018-12-03 23:58 ` Darrick J. Wong
2018-12-04 9:17 ` Amir Goldstein
2018-12-03 23:34 ` Dave Chinner
2018-12-03 18:24 ` Darrick J. Wong
2018-12-04 8:18 ` Olga Kornievskaia
2018-12-03 8:34 ` [PATCH 09/11] vfs: push copy_file_ranges -EXDEV checks down Dave Chinner
2018-12-03 12:36 ` Amir Goldstein
2018-12-03 17:58 ` Olga Kornievskaia
2018-12-03 18:53 ` Anna Schumaker
2018-12-03 19:27 ` Olga Kornievskaia
2018-12-03 23:40 ` Dave Chinner
2018-12-04 15:43 ` Christoph Hellwig
2018-12-04 22:18 ` Dave Chinner
2018-12-04 23:33 ` Olga Kornievskaia
2018-12-05 14:09 ` Christoph Hellwig
2018-12-05 17:01 ` Olga Kornievskaia
2018-12-03 8:34 ` [PATCH 10/11] vfs: allow generic_copy_file_range to copy across devices Dave Chinner
2018-12-03 12:54 ` Amir Goldstein
2018-12-03 8:34 ` [PATCH 11/11] ovl: allow cross-device copy_file_range calls Dave Chinner
2018-12-03 12:55 ` Amir Goldstein
2018-12-03 8:39 ` [PATCH 12/11] man-pages: copy_file_range updates Dave Chinner
2018-12-03 13:05 ` Amir Goldstein
2019-05-21 5:52 ` Amir Goldstein
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