Re: [PATCH] block, bfq: initialize active lists for all actuators

["yu kuai" <yukuai@fygo.io>]

在 2026/10/5 18:41, lirongqing 写道:

> From: Li RongQing<lirongqing@baidu.com>
>
> Commit 2d31c684a053 ("block, bfq: inject I/O to underutilized
> actuators") extended bfqd->active_list from a single list_head to an
> array indexed by actuator, but bfq_init_queue() still only initialized
> the first two entries:
>
>          INIT_LIST_HEAD(&bfqd->active_list[0]);
>          INIT_LIST_HEAD(&bfqd->active_list[1]);
>
> For devices with more than two independent access ranges, the remaining
> list heads stay zeroed by kzalloc() and are never set up as empty lists.
> When BFQ later adds a bfq_queue to one of those lists, list_add() writes
> through head->next, which is NULL, corrupting the list or crashing the
> kernel.
>
> Initialize every actuator's active list using bfqd->num_actuators,
> which is already set up earlier in bfq_init_queue().
>
> Fixes: 2d31c684a053 ("block, bfq: inject I/O to underutilized actuators")
> Signed-off-by: Li RongQing<lirongqing@baidu.com>
> ---
>   block/bfq-iosched.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
Reviewed-by: Yu Kuai <yukuai@fygo.io>

-- 
Thanks,
Kuai