xfs: remove suport for filesystems without unwritten extent flag

The option to enable unwritten extents was made default in 2003,
removed from mkfs in 2007, and cannot be disabled in v5.  We also
rely on it for a lot of common functionality, so filesystems without
it will run a completely untested and buggy code path.  Enabling the
support also is a simple bit flip using xfs_db, so legacy file
systems can still be brought forward.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

1 files changed, 1 insertions, 50 deletions

diff --git a/fs/xfs/xfs_bmap_util.c b/fs/xfs/xfs_bmap_util.c
index 6de8d90041ff..416524f6ba69 100644
--- a/fs/xfs/xfs_bmap_util.c
+++ b/fs/xfs/xfs_bmap_util.c
@@ -1043,44 +1043,6 @@ out_trans_cancel:
 }
 
 static int
-xfs_adjust_extent_unmap_boundaries(
-	struct xfs_inode	*ip,
-	xfs_fileoff_t		*startoffset_fsb,
-	xfs_fileoff_t		*endoffset_fsb)
-{
-	struct xfs_mount	*mp = ip->i_mount;
-	struct xfs_bmbt_irec	imap;
-	int			nimap, error;
-	xfs_extlen_t		mod = 0;
-
-	nimap = 1;
-	error = xfs_bmapi_read(ip, *startoffset_fsb, 1, &imap, &nimap, 0);
-	if (error)
-		return error;
-
-	if (nimap && imap.br_startblock != HOLESTARTBLOCK) {
-		ASSERT(imap.br_startblock != DELAYSTARTBLOCK);
-		div_u64_rem(imap.br_startblock, mp->m_sb.sb_rextsize, &mod);
-		if (mod)
-			*startoffset_fsb += mp->m_sb.sb_rextsize - mod;
-	}
-
-	nimap = 1;
-	error = xfs_bmapi_read(ip, *endoffset_fsb - 1, 1, &imap, &nimap, 0);
-	if (error)
-		return error;
-
-	if (nimap && imap.br_startblock != HOLESTARTBLOCK) {
-		ASSERT(imap.br_startblock != DELAYSTARTBLOCK);
-		mod++;
-		if (mod && mod != mp->m_sb.sb_rextsize)
-			*endoffset_fsb -= mod;
-	}
-
-	return 0;
-}
-
-static int
 xfs_flush_unmap_range(
 	struct xfs_inode	*ip,
 	xfs_off_t		offset,
@@ -1133,19 +1095,8 @@ xfs_free_file_space(
 	endoffset_fsb = XFS_B_TO_FSBT(mp, offset + len);
 
 	/*
-	 * Need to zero the stuff we're not freeing, on disk.  If it's a RT file
-	 * and we can't use unwritten extents then we actually need to ensure
-	 * to zero the whole extent, otherwise we just need to take of block
-	 * boundaries, and xfs_bunmapi will handle the rest.
+	 * Need to zero the stuff we're not freeing, on disk.
 	 */
-	if (XFS_IS_REALTIME_INODE(ip) &&
-	    !xfs_sb_version_hasextflgbit(&mp->m_sb)) {
-		error = xfs_adjust_extent_unmap_boundaries(ip, &startoffset_fsb,
-				&endoffset_fsb);
-		if (error)
-			return error;
-	}
-
 	if (endoffset_fsb > startoffset_fsb) {
 		while (!done) {
 			error = xfs_unmap_extent(ip, startoffset_fsb,