Re: [PATCH 4/6] null_blk: initialize cmd->bio in __alloc_cmd()

[Damien Le Moal]

On 10/5/22 12:16, Chaitanya Kulkarni wrote:
> The function __alloc_cmd() is responsible to allocate tag and
> initializae the different members of the null_cmd structure e.g.
> cmd->tag, cmd->error, and cmd->nq, Move only member bio that is initialized
> from alloc_cmd() into __alloc_cmd().
> 
> Signed-off-by: Chaitanya Kulkarni <kch@xxxxxxxxxx>

Reviewed-by: Damien Le Moal <damien.lemoal@xxxxxxxxxxxxxxxxxx>

> ---
>  drivers/block/null_blk/main.c | 9 ++++-----
>  1 file changed, 4 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/block/null_blk/main.c b/drivers/block/null_blk/main.c
> index b82c2ffeb086..765c1ca0edf5 100644
> --- a/drivers/block/null_blk/main.c
> +++ b/drivers/block/null_blk/main.c
> @@ -743,7 +743,7 @@ static void free_cmd(struct nullb_cmd *cmd)
>  
>  static enum hrtimer_restart null_cmd_timer_expired(struct hrtimer *timer);
>  
> -static struct nullb_cmd *__alloc_cmd(struct nullb_queue *nq)
> +static struct nullb_cmd *__alloc_cmd(struct nullb_queue *nq, struct bio *bio)
>  {
>  	struct nullb_cmd *cmd;
>  	unsigned int tag;
> @@ -754,6 +754,7 @@ static struct nullb_cmd *__alloc_cmd(struct nullb_queue *nq)
>  		cmd->tag = tag;
>  		cmd->error = BLK_STS_OK;
>  		cmd->nq = nq;
> +		cmd->bio = bio;
>  		if (nq->dev->irqmode == NULL_IRQ_TIMER) {
>  			hrtimer_init(&cmd->timer, CLOCK_MONOTONIC,
>  				     HRTIMER_MODE_REL);
> @@ -775,11 +776,9 @@ static struct nullb_cmd *alloc_cmd(struct nullb_queue *nq, struct bio *bio)
>  		 * This avoids multiple return statements, multiple calls to
>  		 * __alloc_cmd() and a fast path call to prepare_to_wait().
>  		 */
> -		cmd = __alloc_cmd(nq);
> -		if (cmd) {
> -			cmd->bio = bio;
> +		cmd = __alloc_cmd(nq, bio);
> +		if (cmd)
>  			return cmd;
> -		}
>  		prepare_to_wait(&nq->wait, &wait, TASK_UNINTERRUPTIBLE);
>  		io_schedule();
>  		finish_wait(&nq->wait, &wait);

-- 
Damien Le Moal
Western Digital Research