Re: [PATCH v2 08/15] blktrace: pass blk_user_trace2 to setup functions

[Damien Le Moal]

On 9/26/25 00:02, Johannes Thumshirn wrote:
> Pass struct blk_user_trace_setup2 to blktrace_setup_finalize(). This
> prepares for the incoming extension of the blktrace protocol with a 64bit
> act_mask.
> 
> Reviewed-by: Christoph Hellwig <hch@xxxxxx>
> Signed-off-by: Johannes Thumshirn <johannes.thumshirn@xxxxxxx>

Reviewed-by: Damien Le Moal <dlemoal@xxxxxxxxxx>

One nit below.

> @@ -649,7 +659,9 @@ int blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
>  		mutex_unlock(&q->debugfs_mutex);
>  		return PTR_ERR(bt);
>  	}
> -	blk_trace_setup_finalize(q, name, bt, &buts);
> +	bt->version = 1;
> +	blk_trace_setup_finalize(q, name, bt, &buts2);

I wonder if it may not be cleaner to pass the version number to
blk_trace_setup_finalize() and have that function do "bt->version = version;" ?


> +	strcpy(buts.name, buts2.name);
>  	mutex_unlock(&q->debugfs_mutex);
>  
>  	if (copy_to_user(arg, &buts, sizeof(buts))) {
> @@ -665,7 +677,7 @@ static int compat_blk_trace_setup(struct request_queue *q, char *name,
>  				  dev_t dev, struct block_device *bdev,
>  				  char __user *arg)
>  {
> -	struct blk_user_trace_setup buts;
> +	struct blk_user_trace_setup2 buts2;
>  	struct compat_blk_user_trace_setup cbuts;
>  	struct blk_trace *bt;
>  
> @@ -675,7 +687,7 @@ static int compat_blk_trace_setup(struct request_queue *q, char *name,
>  	if (!cbuts.buf_size || !cbuts.buf_nr)
>  		return -EINVAL;
>  
> -	buts = (struct blk_user_trace_setup) {
> +	buts2 = (struct blk_user_trace_setup2) {
>  		.act_mask = cbuts.act_mask,
>  		.buf_size = cbuts.buf_size,
>  		.buf_nr = cbuts.buf_nr,
> @@ -685,16 +697,17 @@ static int compat_blk_trace_setup(struct request_queue *q, char *name,
>  	};
>  
>  	mutex_lock(&q->debugfs_mutex);
> -	bt = blk_trace_setup_prepare(q, name, dev, buts.buf_size, buts.buf_nr,
> +	bt = blk_trace_setup_prepare(q, name, dev, buts2.buf_size, buts2.buf_nr,
>  				     bdev);
>  	if (IS_ERR(bt)) {
>  		mutex_unlock(&q->debugfs_mutex);
>  		return PTR_ERR(bt);
>  	}
> -	blk_trace_setup_finalize(q, name, bt, &buts);
> +	bt->version = 1;
> +	blk_trace_setup_finalize(q, name, bt, &buts2);
>  	mutex_unlock(&q->debugfs_mutex);
>  
> -	if (copy_to_user(arg, &buts.name, ARRAY_SIZE(buts.name))) {
> +	if (copy_to_user(arg, &buts2.name, ARRAY_SIZE(buts2.name))) {
>  		blk_trace_remove(q);
>  		return -EFAULT;
>  	}


-- 
Damien Le Moal
Western Digital Research