fs: btrfs: Fix wrong comparison in logical to physical mapping

The comparison
  logical > item->logical + item->length
in btrfs_map_logical_to_physical is wrong and should be instead
  logical >= item->logical + item->length
For example, if
  item->logical = 4096
  item->length = 4096
and we are looking for logical = 8192, it is not part of item (item is
[4096, 8191]). But the comparison is false and we think we have found
the correct item, although we should be searing in the right subtree.

This fixes some bugs I encountered.

Signed-off-by: Marek Behun <marek.behun@nic.cz>

diff --git a/fs/btrfs/chunk-map.c b/fs/btrfs/chunk-map.c
index beb6a4b..0c9a659 100644 (file)
--- a/fs/btrfs/chunk-map.c
+++ b/fs/btrfs/chunk-map.c
@@ -78,7 +78,7 @@ u64 btrfs_map_logical_to_physical(u64 logical)
 
                if (item->logical > logical)
                        node = node->rb_left;
-               else if (logical > item->logical + item->length)
+               else if (logical >= item->logical + item->length)
                        node = node->rb_right;
                else
                        return item->physical + logical - item->logical;