[Drbd-dev] [PATCH 14/26] md: convert to blk_alloc_disk/blk_cleanup_disk

[Hannes Reinecke]

On 5/21/21 7:51 AM, Christoph Hellwig wrote:
> Convert the md driver to use the blk_alloc_disk and blk_cleanup_disk
> helpers to simplify gendisk and request_queue allocation.
> 
> Signed-off-by: Christoph Hellwig <hch at lst.de>
> ---
>   drivers/md/md.c | 25 +++++++++----------------
>   1 file changed, 9 insertions(+), 16 deletions(-)
> 
> diff --git a/drivers/md/md.c b/drivers/md/md.c
> index 49f897fbb89b..d806be8cc210 100644
> --- a/drivers/md/md.c
> +++ b/drivers/md/md.c
> @@ -5598,12 +5598,10 @@ static void md_free(struct kobject *ko)
>   	if (mddev->sysfs_level)
>   		sysfs_put(mddev->sysfs_level);
>   
> -	if (mddev->gendisk)
> +	if (mddev->gendisk) {
>   		del_gendisk(mddev->gendisk);
> -	if (mddev->queue)
> -		blk_cleanup_queue(mddev->queue);
> -	if (mddev->gendisk)
> -		put_disk(mddev->gendisk);
> +		blk_cleanup_disk(mddev->gendisk);
> +	}
>   	percpu_ref_exit(&mddev->writes_pending);
>   
>   	bioset_exit(&mddev->bio_set);
> @@ -5711,20 +5709,13 @@ static int md_alloc(dev_t dev, char *name)
>   		goto abort;
>   
>   	error = -ENOMEM;
> -	mddev->queue = blk_alloc_queue(NUMA_NO_NODE);
> -	if (!mddev->queue)
> +	disk = blk_alloc_disk(NUMA_NO_NODE);
> +	if (!disk)
>   		goto abort;
>   
> -	blk_set_stacking_limits(&mddev->queue->limits);
> -
> -	disk = alloc_disk(1 << shift);
> -	if (!disk) {
> -		blk_cleanup_queue(mddev->queue);
> -		mddev->queue = NULL;
> -		goto abort;
> -	}
>   	disk->major = MAJOR(mddev->unit);
>   	disk->first_minor = unit << shift;
> +	disk->minors = 1 << shift;
>   	if (name)
>   		strcpy(disk->disk_name, name);
>   	else if (partitioned)
> @@ -5733,7 +5724,9 @@ static int md_alloc(dev_t dev, char *name)
>   		sprintf(disk->disk_name, "md%d", unit);
>   	disk->fops = &md_fops;
>   	disk->private_data = mddev;
> -	disk->queue = mddev->queue;
> +
> +	mddev->queue = disk->queue;
> +	blk_set_stacking_limits(&mddev->queue->limits);
>   	blk_queue_write_cache(mddev->queue, true, true);
>   	/* Allow extended partitions.  This makes the
>   	 * 'mdp' device redundant, but we can't really
> 
Wouldn't it make sense to introduce a helper 'blk_queue_from_disk()' or 
somesuch to avoid having to keep an explicit 'queue' pointer?


Cheers,

Hannes
-- 
Dr. Hannes Reinecke                Kernel Storage Architect
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