Re: [PATCH 02/15] xfs: refactor clonerange preparation into a separate helper

[Dave Chinner <david@fromorbit.com>]

On Fri, Oct 05, 2018 at 05:02:28PM +1000, Dave Chinner wrote:
> On Thu, Oct 04, 2018 at 05:44:47PM -0700, Darrick J. Wong wrote:
> > From: Darrick J. Wong <darrick.wong@oracle.com>
> > 
> > Refactor all the reflink preparation steps into a separate helper that
> > we'll use to land all the upcoming fixes for insufficient input checks.
> > 
> > Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
> .....
> 
> > +xfs_reflink_remap_range(
> > +	struct file		*file_in,
> > +	loff_t			pos_in,
> > +	struct file		*file_out,
> > +	loff_t			pos_out,
> > +	u64			len,
> > +	bool			is_dedupe)
> > +{
> > +	struct inode		*inode_in = file_inode(file_in);
> > +	struct xfs_inode	*src = XFS_I(inode_in);
> > +	struct inode		*inode_out = file_inode(file_out);
> > +	struct xfs_inode	*dest = XFS_I(inode_out);
> > +	struct xfs_mount	*mp = src->i_mount;
> > +	xfs_fileoff_t		sfsbno, dfsbno;
> > +	xfs_filblks_t		fsblen;
> > +	xfs_extlen_t		cowextsize;
> > +	ssize_t			ret;
> > +
> > +	if (!xfs_sb_version_hasreflink(&mp->m_sb))
> > +		return -EOPNOTSUPP;
> > +
> > +	if (XFS_FORCED_SHUTDOWN(mp))
> > +		return -EIO;
> > +
> > +	/* Prepare and then clone file data. */
> > +	ret = xfs_reflink_remap_prep(file_in, pos_in, file_out, pos_out,
> > +			len, is_dedupe);

More than one bug. vfs_clone_file_prep_inodes() modifes the length
parameter in the case of whole file reflink by way of "len == 0"
on a non-zero length file. So I fixed this, too.

-Dave.
-- 
Dave Chinner
david@fromorbit.com