On 08/29/18 21:15, Damien Le Moal wrote:
> For an I/O trying to read an offline zone, another zone must be chosen
> using zbd_find_zone(). However, in zbd_adjust_block(), the variable
> range is set to 0 for an offline zone, which in the case of a random
> read pattern causes evaluation of the first if condition of the
> DDIR_READ case to true, resulting in the use of the offline zone.
>
> Fix this simply by setting range to -1 so that the first if statement is
> false and zbd_find_zone() executed.
>
> Signed-off-by: Damien Le Moal <damien.lemoal@xxxxxxx>
> ---
> zbd.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/zbd.c b/zbd.c
> index 19511454..e98c5a50 100644
> --- a/zbd.c
> +++ b/zbd.c
> @@ -1157,7 +1157,7 @@ enum io_u_action zbd_adjust_block(struct thread_data *td, struct io_u *io_u)
> * hit the medium.
> */
> range = zb->cond != BLK_ZONE_COND_OFFLINE ?
> - ((zb->wp - zb->start) << 9) - io_u->buflen : 0;
> + ((zb->wp - zb->start) << 9) - io_u->buflen : -1;
> if (td_random(td) && range >= 0) {
> io_u->offset = (zb->start << 9) +
> ((io_u->offset - (zb->start << 9)) %
>
Reviewed-by: Bart Van Assche <bvanassche@xxxxxxx>
