[PATCH] btrfs: read key again after incrementing slot in move_existing_remaps()

[Mark Harmstone <mark@harmstone.com>]

Fix move_existing_remaps() so that if we increment the slot because the
key we encounter isn't a REMAP_BACKREF, we don't reuse the objectid and
offset of the old item.

Link: https://lore.kernel.org/linux-btrfs/20260125123908.2096548-1-clm@meta.com/
Reported-by: Chris Mason <clm@fb.com>
Fixes: bbea42dfb91f ("btrfs: move existing remaps before relocating block group")
Signed-off-by: Mark Harmstone <mark@harmstone.com>
---
 fs/btrfs/relocation.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c
index 5a8644667620..2dee4d708f95 100644
--- a/fs/btrfs/relocation.c
+++ b/fs/btrfs/relocation.c
@@ -4394,6 +4394,8 @@ static int move_existing_remaps(struct btrfs_fs_info *fs_info,
 
 				leaf = path->nodes[0];
 			}
+
+			btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
 		}
 
 		remap = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_remap_item);
-- 
2.52.0