xfs: revert "xfs: factor rmap btree size into the indlen calculations"

In commit fd26a88093ba we added a worst case estimate for rmapbt blocks
needed to satisfy the block mapping request.  Since then, we added the
ability to reserve enough space in each AG such that we should never run
out of blocks to grow the rmapbt, which makes this calculation
unnecessary.  Revert the commit because it makes the extra delalloc
indlen accounting unnecessary and incorrect.

Reported-by: Eryu Guan <eguan@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

fs/xfs/libxfs/xfs_bmap.c

@@ -49,7 +49,6 @@
 #include "xfs_rmap.h"
 #include "xfs_ag_resv.h"
 #include "xfs_refcount.h"
-#include "xfs_rmap_btree.h"
 #include "xfs_icache.h"
 
 
@@ -192,12 +191,8 @@ xfs_bmap_worst_indlen(
 	int		maxrecs;	/* maximum record count at this level */
 	xfs_mount_t	*mp;		/* mount structure */
 	xfs_filblks_t	rval;		/* return value */
-	xfs_filblks_t   orig_len;
 
 	mp = ip->i_mount;
-
-	/* Calculate the worst-case size of the bmbt. */
-	orig_len = len;
 	maxrecs = mp->m_bmap_dmxr[0];
 	for (level = 0, rval = 0;
 	     level < XFS_BM_MAXLEVELS(mp, XFS_DATA_FORK);
@@ -205,20 +200,12 @@ xfs_bmap_worst_indlen(
 		len += maxrecs - 1;
 		do_div(len, maxrecs);
 		rval += len;
-		if (len == 1) {
-			rval += XFS_BM_MAXLEVELS(mp, XFS_DATA_FORK) -
+		if (len == 1)
+			return rval + XFS_BM_MAXLEVELS(mp, XFS_DATA_FORK) -
 				level - 1;
-			break;
-		}
 		if (level == 0)
 			maxrecs = mp->m_bmap_dmxr[1];
 	}
-
-	/* Calculate the worst-case size of the rmapbt. */
-	if (xfs_sb_version_hasrmapbt(&mp->m_sb))
-		rval += 1 + xfs_rmapbt_calc_size(mp, orig_len) +
-				mp->m_rmap_maxlevels;
-
 	return rval;
 }