Re: [PATCH] block: avoild hang when bio_list is non-NULL in submit_bio_wait()

[Gao Xiang <hsiangkao@linux.alibaba.com>]

On 2026/3/2 22:29, Christoph Hellwig wrote:
> On Mon, Mar 02, 2026 at 10:23:04PM +0800, Gao Xiang wrote:
>>>> I've trimmed down the call stack, as follows:
>>>>
>>>> f2fs_submit_read_io
>>>>     submit_bio
>>>>       mmc_blk_mq_recovery
>>>>         z_erofs_endio
>>>>           vm_map_ram
>>>
>>> ->bi_end_io code really should not be having random in_atomic()
>>> checks that make it completely different, but even if they have
>>
>> Thanks for the head-up.
>>
>> For this part, I'm pretty sure we need this particular one
>> otherwise the scheduling performance (latency sensitive)
>> is unacceptable for all Android phone users.
> 
> Where do you regularly get user context calls to ->bi_end_io?

The obvious one is that dm-verity, it's actually in
the workqueue context.

Thanks,
Gao Xiang