On 7/8/20 3:27 AM, John Garry wrote:
> On 03/07/2020 14:01, Hannes Reinecke wrote:
>
> +linux-block
>
> I figure that linux-block should be cc'ed here
>
>> Some drivers require to allocate requests for internal command
>> submission. These request will never be passed through the block
>> layer, but nevertheless require a valid tag to avoid them clashing
>> with normal I/O commands.
>> This patch adds a new request flag REQ_INTERNAL to mark such
>> requests and a terminates any such commands in blk_execute_rq_nowait()
>> with a WARN_ON_ONCE to signal such an invalid usage.
>>
>> Signed-off-by: Hannes Reinecke <hare@xxxxxxx>
>> ---
>> block/blk-exec.c | 5 +++++
>> include/linux/blk_types.h | 2 ++
>> include/linux/blkdev.h | 5 +++++
>> 3 files changed, 12 insertions(+)
>>
>> diff --git a/block/blk-exec.c b/block/blk-exec.c
>> index 85324d53d072..6869877e0d21 100644
>> --- a/block/blk-exec.c
>> +++ b/block/blk-exec.c
>> @@ -55,6 +55,11 @@ void blk_execute_rq_nowait(struct request_queue *q, struct gendisk *bd_disk,
>> rq->rq_disk = bd_disk;
>> rq->end_io = done;
>>
>> + if (WARN_ON_ONCE(blk_rq_is_internal(rq))) {
>> + blk_mq_end_request(rq, BLK_STS_NOTSUPP);
>> + return;
>> + }
>> +
>> blk_account_io_start(rq);
The whole concept seems very odd, and then there's this seemingly
randomly placed check and error condition. As I haven't seen the
actual use case for this, hard to make suggestions though.
--
Jens Axboe
