[PATCH 19/28] xfs: fix xfs_rtrmapbt_mem_cursor for non-rmap filesystems

[Andrey Albershteyn <aalbersh@kernel.org>]

From: "Darrick J. Wong" <djwong@kernel.org>

Source kernel commit: 022d5f5fce7f0b6125d404eb74044e6238aef369

It's possible to construct an in-memory rtrmap btree for filesystems
that don't have the rmap feature enabled.  The kernel doesn't do this,
but xfs_repair will, if asked to reindex a filesystem that has rtreflink
enabled but not rtrmap.  Therefore, we must create the cursor with
enough levels to handle a maximally sized btree possible.

Note that the rtrmapbt btree cursor slab creates objects large enough to
handle xfs_rtrmap_maxlevels_ondisk() levels, so setting bc_nlevels to
the same value isn't costing us any extra memory.

Fixes: 4a61f12eb11958 ("xfs: create a shadow rmap btree during realtime rmap repair")
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Carlos Maiolino <cem@kernel.org>
---
 libxfs/xfs_rtrmap_btree.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libxfs/xfs_rtrmap_btree.c b/libxfs/xfs_rtrmap_btree.c
index 0cb2113d5b40..a15e460a1ec7 100644
--- a/libxfs/xfs_rtrmap_btree.c
+++ b/libxfs/xfs_rtrmap_btree.c
@@ -618,7 +618,7 @@ xfs_rtrmapbt_mem_cursor(
 	struct xfs_btree_cur	*cur;
 
 	cur = xfs_btree_alloc_cursor(mp, tp, &xfs_rtrmapbt_mem_ops,
-			mp->m_rtrmap_maxlevels, xfs_rtrmapbt_cur_cache);
+			xfs_rtrmapbt_maxlevels_ondisk(), xfs_rtrmapbt_cur_cache);
 	cur->bc_mem.xfbtree = xfbt;
 	cur->bc_nlevels = xfbt->nlevels;
 	cur->bc_group = xfs_group_hold(rtg_group(rtg));
-- 
2.54.0