[U-Boot] [PATCH] fs: btrfs: Fix wrong comparison in logical to physical mapping

[Joakim Tjernlund]

On Wed, 2018-07-04 at 19:10 +0200, Marek Behún wrote:
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> 
> 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 at nic.cz>
> ---
>  fs/btrfs/chunk-map.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/fs/btrfs/chunk-map.c b/fs/btrfs/chunk-map.c
> index beb6a4bb92..31619f6241 100644
> --- 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 - 1)
            maybe          logical >= item->logical + item->length   ?

>                         node = node->rb_right;