Re: [PATCH] block: ensure we hold a queue reference when using queue limits

[Jens Axboe <axboe@kernel.dk>]

On 1/12/24 7:05 PM, Ming Lei wrote:
> On Sat, Jan 13, 2024 at 12:15?AM Jens Axboe <axboe@kernel.dk> wrote:
>>
>> q_usage_counter is the only thing preventing us from the limits changing
>> under us in __bio_split_to_limits, but blk_mq_submit_bio doesn't hold
>> it while calling into it.
>>
>> Move the splitting inside the region where we know we've got a queue
>> reference. Ideally this could still remain a shared section of code, but
>> let's keep the fix simple and defer any refactoring here to later.
>>
>> Reported-by: Christoph Hellwig <hch@lst.de>
>> Fixes: 9d497e2941c3 ("block: don't protect submit_bio_checks by q_usage_counter")
> 
> The fixes tag is wrong, and it should be:
> 
> Fixes: 900e08075202 ("block: move queue enter logic into blk_mq_submit_bio()")

You're right, I fixed it up.

-- 
Jens Axboe