xfs: fix incorrect extent state in xfs_bmap_add_extent_unwritten_real

BugLink: http://bugs.launchpad.net/bugs/1745052

[ Upstream commit 5e422f5e ]

There was one spot in xfs_bmap_add_extent_unwritten_real that didn't use the
passed in new extent state but always converted to normal, leading to wrong
behavior when converting from normal to unwritten.

Only found by code inspection, it seems like this code path to move partial
extent from written to unwritten while merging it with the next extent is
rarely exercised.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>

fs/xfs/libxfs/xfs_bmap.c

@@ -2670,7 +2670,7 @@ xfs_bmap_add_extent_unwritten_real(
 					&i)))
 				goto done;
 			XFS_WANT_CORRUPTED_GOTO(mp, i == 0, done);
-			cur->bc_rec.b.br_state = XFS_EXT_NORM;
+			cur->bc_rec.b.br_state = new->br_state;
 			if ((error = xfs_btree_insert(cur, &i)))
 				goto done;
 			XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);