Commit 3f68c1f5 authored by Darrick J. Wong's avatar Darrick J. Wong Committed by Dave Chinner
Browse files

xfs: support returning partial reflink results 



Back when the XFS reflink code only supported clone_file_range, we were
only able to return zero or negative error codes to userspace.  However,
now that copy_file_range (which returns bytes copied) can use XFS'
clone_file_range, we have the opportunity to return partial results.
For example, if userspace sends a 1GB clone request and we run out of
space halfway through, we at least can tell userspace that we completed
512M of that request like a regular write.

Signed-off-by: default avatarDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: default avatarDave Chinner <dchinner@redhat.com>
Signed-off-by: default avatarDave Chinner <david@fromorbit.com>
parent 9f04aaff

fs/xfs/xfs_file.c

+1 −4
Original line number Diff line number Diff line
@@ -928,14 +928,11 @@ xfs_file_remap_range( 
	loff_t		len,

	unsigned int	remap_flags)

{

	int		ret;



	if (remap_flags & ~(REMAP_FILE_DEDUP | REMAP_FILE_ADVISORY))

		return -EINVAL;



	ret = xfs_reflink_remap_range(file_in, pos_in, file_out, pos_out,

	return xfs_reflink_remap_range(file_in, pos_in, file_out, pos_out,

			len, remap_flags);

	return ret < 0 ? ret : len;

}



STATIC int

fs/xfs/xfs_reflink.c

+12 −5
Original line number Diff line number Diff line
@@ -1122,13 +1122,15 @@ xfs_reflink_remap_blocks( 
	loff_t			pos_in,

	struct xfs_inode	*dest,

	loff_t			pos_out,

	loff_t			remap_len)

	loff_t			remap_len,

	loff_t			*remapped)

{

	struct xfs_bmbt_irec	imap;

	xfs_fileoff_t		srcoff;

	xfs_fileoff_t		destoff;

	xfs_filblks_t		len;

	xfs_filblks_t		range_len;

	xfs_filblks_t		remapped_len = 0;

	xfs_off_t		new_isize = pos_out + remap_len;

	int			nimaps;

	int			error = 0;
@@ -1175,10 +1177,13 @@ xfs_reflink_remap_blocks( 
		srcoff += range_len;

		destoff += range_len;

		len -= range_len;

		remapped_len += range_len;

	}



	if (error)

		trace_xfs_reflink_remap_blocks_error(dest, error, _RET_IP_);

	*remapped = min_t(loff_t, remap_len,

			  XFS_FSB_TO_B(src->i_mount, remapped_len));

	return error;

}
@@ -1387,7 +1392,7 @@ out_unlock: 
/*

 * Link a range of blocks from one file to another.

 */

int

loff_t

xfs_reflink_remap_range(

	struct file		*file_in,

	loff_t			pos_in,
@@ -1401,8 +1406,9 @@ xfs_reflink_remap_range( 
	struct inode		*inode_out = file_inode(file_out);

	struct xfs_inode	*dest = XFS_I(inode_out);

	struct xfs_mount	*mp = src->i_mount;

	loff_t			remapped = 0;

	xfs_extlen_t		cowextsize;

	ssize_t			ret;

	int			ret;



	if (!xfs_sb_version_hasreflink(&mp->m_sb))

		return -EOPNOTSUPP;
@@ -1418,7 +1424,8 @@ xfs_reflink_remap_range( 


	trace_xfs_reflink_remap_range(src, pos_in, len, dest, pos_out);



	ret = xfs_reflink_remap_blocks(src, pos_in, dest, pos_out, len);

	ret = xfs_reflink_remap_blocks(src, pos_in, dest, pos_out, len,

			&remapped);

	if (ret)

		goto out_unlock;
@@ -1441,7 +1448,7 @@ out_unlock: 
	xfs_reflink_remap_unlock(file_in, file_out);

	if (ret)

		trace_xfs_reflink_remap_range_error(dest, ret, _RET_IP_);

	return ret;

	return remapped > 0 ? remapped : ret;

}



/*

fs/xfs/xfs_reflink.h

+1 −1
Original line number Diff line number Diff line
@@ -27,7 +27,7 @@ extern int xfs_reflink_cancel_cow_range(struct xfs_inode *ip, xfs_off_t offset, 
extern int xfs_reflink_end_cow(struct xfs_inode *ip, xfs_off_t offset,

		xfs_off_t count);

extern int xfs_reflink_recover_cow(struct xfs_mount *mp);

extern int xfs_reflink_remap_range(struct file *file_in, loff_t pos_in,

extern loff_t xfs_reflink_remap_range(struct file *file_in, loff_t pos_in,

		struct file *file_out, loff_t pos_out, loff_t len,

		unsigned int remap_flags);

extern int xfs_reflink_inode_has_shared_extents(struct xfs_trans *tp,

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