xfs: use iomap_bmap

Switch to the iomap based bmap implementation to get rid of one of the
last users of xfs_get_blocks.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

fs/xfs/xfs_aops.c

@@ -1378,10 +1378,9 @@ xfs_vm_bmap(
 	struct address_space	*mapping,
 	sector_t		block)
 {
-	struct inode		*inode = (struct inode *)mapping->host;
-	struct xfs_inode	*ip = XFS_I(inode);
+	struct xfs_inode	*ip = XFS_I(mapping->host);
 
-	trace_xfs_vm_bmap(XFS_I(inode));
+	trace_xfs_vm_bmap(ip);
 
 	/*
 	 * The swap code (ab-)uses ->bmap to get a block mapping and then
@@ -1394,9 +1393,7 @@ xfs_vm_bmap(
 	 */
 	if (xfs_is_reflink_inode(ip) || XFS_IS_REALTIME_INODE(ip))
 		return 0;
-
-	filemap_write_and_wait(mapping);
-	return generic_block_bmap(mapping, block, xfs_get_blocks);
+	return iomap_bmap(mapping, block, &xfs_iomap_ops);
 }
 
 STATIC int