On 10/08/2018 02:30 PM, Qu Wenruo wrote:
> Obviously, used bytes can't be larger than total bytes.
>
> Signed-off-by: Qu Wenruo <wqu@xxxxxxxx>
> ---
> check/mode-lowmem.c | 5 +++++
> 1 file changed, 5 insertions(+)
>
> diff --git a/check/mode-lowmem.c b/check/mode-lowmem.c
> index 07c03cad77af..1173b963b8f3 100644
> --- a/check/mode-lowmem.c
> +++ b/check/mode-lowmem.c
> @@ -4074,6 +4074,11 @@ static int check_dev_item(struct btrfs_fs_info *fs_info,
> used = btrfs_device_bytes_used(eb, dev_item);
> total_bytes = btrfs_device_total_bytes(eb, dev_item);
>
> + if (used > total_bytes) {
> + error("device %llu has incorrect used bytes %llu > total bytes %llu",
> + dev_id, used, total_bytes);
> + return ACCOUNTING_MISMATCH;
The message and return code point at an error in accounting logic.
However, if you have a fully allocated device and a DUP chunk ending
beyond device, then having used > total_bytes is expected...
So maybe there's two possibilities... There's an error in the accounting
logic, or there's an "over-allocation", which is another type of issue
which produces used > total with correct accounting logic.
> + }
> key.objectid = dev_id;
> key.type = BTRFS_DEV_EXTENT_KEY;
> key.offset = 0;
>
--
Hans van Kranenburg
