[13/26] dm: convert to blk_alloc_disk/blk_cleanup_disk

Message ID 20210521055116.1053587-14-hch@lst.de
State New
Headers show
Series
  • [01/26] block: refactor device number setup in __device_add_disk
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Commit Message

Christoph Hellwig May 21, 2021, 5:51 a.m.
Convert the dm 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@lst.de>
---
 drivers/md/dm.c | 16 +++++++---------
 1 file changed, 7 insertions(+), 9 deletions(-)

Comments

Hannes Reinecke May 23, 2021, 8:10 a.m. | #1
On 5/21/21 7:51 AM, Christoph Hellwig wrote:
> Convert the dm 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@lst.de>

> ---

>   drivers/md/dm.c | 16 +++++++---------

>   1 file changed, 7 insertions(+), 9 deletions(-)

> 

> diff --git a/drivers/md/dm.c b/drivers/md/dm.c

> index ca2aedd8ee7d..3c7c2d257018 100644

> --- a/drivers/md/dm.c

> +++ b/drivers/md/dm.c

> @@ -1801,13 +1801,13 @@ static void cleanup_mapped_device(struct mapped_device *md)

>   		md->disk->private_data = NULL;

>   		spin_unlock(&_minor_lock);

>   		del_gendisk(md->disk);

> -		put_disk(md->disk);

>   	}

>   

> -	if (md->queue) {

> +	if (md->queue)

>   		dm_queue_destroy_keyslot_manager(md->queue);

> -		blk_cleanup_queue(md->queue);

> -	}

> +

> +	if (md->disk)

> +		blk_cleanup_disk(md->disk);

>   

>   	cleanup_srcu_struct(&md->io_barrier);

>   


Can't these conditionals be merged into a single 'if (md->disk)'?
Eg like:

	if (md->disk) {
		spin_lock(&_minor_lock);
		md->disk->private_data = NULL;
		spin_unlock(&_minor_lock);
		del_gendisk(md->disk);
		dm_queue_destroy_keyslot_manager(md->queue);
		blk_cleanup_disk(md->queue);
	}

We're now always allocating 'md->disk' and 'md->queue' together,
so how can we end up in a situation where one is set without the other?

> @@ -1869,13 +1869,10 @@ static struct mapped_device *alloc_dev(int minor)

>   	 * established. If request-based table is loaded: blk-mq will

>   	 * override accordingly.

>   	 */

> -	md->queue = blk_alloc_queue(numa_node_id);

> -	if (!md->queue)

> -		goto bad;

> -

> -	md->disk = alloc_disk_node(1, md->numa_node_id);

> +	md->disk = blk_alloc_disk(md->numa_node_id);

>   	if (!md->disk)

>   		goto bad;

> +	md->queue = md->disk->queue;

>   

>   	init_waitqueue_head(&md->wait);

>   	INIT_WORK(&md->work, dm_wq_work);

> @@ -1888,6 +1885,7 @@ static struct mapped_device *alloc_dev(int minor)

>   

>   	md->disk->major = _major;

>   	md->disk->first_minor = minor;

> +	md->disk->minors = 1;

>   	md->disk->fops = &dm_blk_dops;

>   	md->disk->queue = md->queue;

>   	md->disk->private_data = md;

> 

Cheers,

Hannes
-- 
Dr. Hannes Reinecke                Kernel Storage Architect
hare@suse.de                              +49 911 74053 688
SUSE Software Solutions GmbH, Maxfeldstr. 5, 90409 Nürnberg
HRB 36809 (AG Nürnberg), Geschäftsführer: Felix Imendörffer
Christoph Hellwig May 24, 2021, 7:25 a.m. | #2
On Sun, May 23, 2021 at 10:10:34AM +0200, Hannes Reinecke wrote:
> Can't these conditionals be merged into a single 'if (md->disk)'?

> Eg like:

>

> 	if (md->disk) {

> 		spin_lock(&_minor_lock);

> 		md->disk->private_data = NULL;

> 		spin_unlock(&_minor_lock);

> 		del_gendisk(md->disk);

> 		dm_queue_destroy_keyslot_manager(md->queue);

> 		blk_cleanup_disk(md->queue);

> 	}

>

> We're now always allocating 'md->disk' and 'md->queue' together,

> so how can we end up in a situation where one is set without the other?


I guess we could do that, not sure it is worth the churn, though.

Patch

diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index ca2aedd8ee7d..3c7c2d257018 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -1801,13 +1801,13 @@  static void cleanup_mapped_device(struct mapped_device *md)
 		md->disk->private_data = NULL;
 		spin_unlock(&_minor_lock);
 		del_gendisk(md->disk);
-		put_disk(md->disk);
 	}
 
-	if (md->queue) {
+	if (md->queue)
 		dm_queue_destroy_keyslot_manager(md->queue);
-		blk_cleanup_queue(md->queue);
-	}
+
+	if (md->disk)
+		blk_cleanup_disk(md->disk);
 
 	cleanup_srcu_struct(&md->io_barrier);
 
@@ -1869,13 +1869,10 @@  static struct mapped_device *alloc_dev(int minor)
 	 * established. If request-based table is loaded: blk-mq will
 	 * override accordingly.
 	 */
-	md->queue = blk_alloc_queue(numa_node_id);
-	if (!md->queue)
-		goto bad;
-
-	md->disk = alloc_disk_node(1, md->numa_node_id);
+	md->disk = blk_alloc_disk(md->numa_node_id);
 	if (!md->disk)
 		goto bad;
+	md->queue = md->disk->queue;
 
 	init_waitqueue_head(&md->wait);
 	INIT_WORK(&md->work, dm_wq_work);
@@ -1888,6 +1885,7 @@  static struct mapped_device *alloc_dev(int minor)
 
 	md->disk->major = _major;
 	md->disk->first_minor = minor;
+	md->disk->minors = 1;
 	md->disk->fops = &dm_blk_dops;
 	md->disk->queue = md->queue;
 	md->disk->private_data = md;