diff mbox series

[06/26] brd: convert to blk_alloc_disk/blk_cleanup_disk

Message ID 20210521055116.1053587-7-hch@lst.de (mailing list archive)
State New
Headers show
Series [01/26] block: refactor device number setup in __device_add_disk | expand

Commit Message

Christoph Hellwig May 21, 2021, 5:50 a.m. UTC
Convert the brd driver to use the blk_alloc_disk and blk_cleanup_disk
helpers to simplify gendisk and request_queue allocation.  This also
allows to remove the request_queue pointer in struct request_queue,
and to simplify the initialization as blk_cleanup_disk can be called
on any disk returned from blk_alloc_disk.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 drivers/block/brd.c | 94 ++++++++++++++++-----------------------------
 1 file changed, 33 insertions(+), 61 deletions(-)

Comments

Hannes Reinecke May 23, 2021, 7:58 a.m. UTC | #1
On 5/21/21 7:50 AM, Christoph Hellwig wrote:
> Convert the brd driver to use the blk_alloc_disk and blk_cleanup_disk
> helpers to simplify gendisk and request_queue allocation.  This also
> allows to remove the request_queue pointer in struct request_queue,
> and to simplify the initialization as blk_cleanup_disk can be called
> on any disk returned from blk_alloc_disk.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>   drivers/block/brd.c | 94 ++++++++++++++++-----------------------------
>   1 file changed, 33 insertions(+), 61 deletions(-)
> 
> diff --git a/drivers/block/brd.c b/drivers/block/brd.c
> index 7562cf30b14e..95694113e38e 100644
> --- a/drivers/block/brd.c
> +++ b/drivers/block/brd.c
> @@ -38,9 +38,7 @@
>    * device).
>    */
>   struct brd_device {
> -	int		brd_number;
> -
> -	struct request_queue	*brd_queue;
> +	int			brd_number;
>   	struct gendisk		*brd_disk;
>   	struct list_head	brd_list;
>   
> @@ -372,7 +370,7 @@ static LIST_HEAD(brd_devices);
>   static DEFINE_MUTEX(brd_devices_mutex);
>   static struct dentry *brd_debugfs_dir;
>   
> -static struct brd_device *brd_alloc(int i)
> +static int brd_alloc(int i)
>   {
>   	struct brd_device *brd;
>   	struct gendisk *disk;
> @@ -380,64 +378,55 @@ static struct brd_device *brd_alloc(int i)
>   
>   	brd = kzalloc(sizeof(*brd), GFP_KERNEL);
>   	if (!brd)
> -		goto out;
> +		return -ENOMEM;
>   	brd->brd_number		= i;
>   	spin_lock_init(&brd->brd_lock);
>   	INIT_RADIX_TREE(&brd->brd_pages, GFP_ATOMIC);
>   
> -	brd->brd_queue = blk_alloc_queue(NUMA_NO_NODE);
> -	if (!brd->brd_queue)
> -		goto out_free_dev;
> -
>   	snprintf(buf, DISK_NAME_LEN, "ram%d", i);
>   	if (!IS_ERR_OR_NULL(brd_debugfs_dir))
>   		debugfs_create_u64(buf, 0444, brd_debugfs_dir,
>   				&brd->brd_nr_pages);
>   
> -	/* This is so fdisk will align partitions on 4k, because of
> -	 * direct_access API needing 4k alignment, returning a PFN
> -	 * (This is only a problem on very small devices <= 4M,
> -	 *  otherwise fdisk will align on 1M. Regardless this call
> -	 *  is harmless)
> -	 */
> -	blk_queue_physical_block_size(brd->brd_queue, PAGE_SIZE);
> -	disk = brd->brd_disk = alloc_disk(max_part);
> +	disk = brd->brd_disk = blk_alloc_disk(NUMA_NO_NODE);
>   	if (!disk)
> -		goto out_free_queue;
> +		goto out_free_dev;
> +
>   	disk->major		= RAMDISK_MAJOR;
>   	disk->first_minor	= i * max_part;
> +	disk->minors		= max_part;
>   	disk->fops		= &brd_fops;
>   	disk->private_data	= brd;
>   	disk->flags		= GENHD_FL_EXT_DEVT;
>   	strlcpy(disk->disk_name, buf, DISK_NAME_LEN);
>   	set_capacity(disk, rd_size * 2);
> +	
> +	/*
> +	 * This is so fdisk will align partitions on 4k, because of
> +	 * direct_access API needing 4k alignment, returning a PFN
> +	 * (This is only a problem on very small devices <= 4M,
> +	 *  otherwise fdisk will align on 1M. Regardless this call
> +	 *  is harmless)
> +	 */
> +	blk_queue_physical_block_size(disk->queue, PAGE_SIZE);
>   

Maybe converting the comment to refer to 'PAGE_SIZE' instead of 4k while 
you're at it ...

>   	/* Tell the block layer that this is not a rotational device */
> -	blk_queue_flag_set(QUEUE_FLAG_NONROT, brd->brd_queue);
> -	blk_queue_flag_clear(QUEUE_FLAG_ADD_RANDOM, brd->brd_queue);
> +	blk_queue_flag_set(QUEUE_FLAG_NONROT, disk->queue);
> +	blk_queue_flag_clear(QUEUE_FLAG_ADD_RANDOM, disk->queue);
> +	add_disk(disk);
> +	list_add_tail(&brd->brd_list, &brd_devices);
>   
> -	return brd;
> +	return 0;
>   
> -out_free_queue:
> -	blk_cleanup_queue(brd->brd_queue);
>   out_free_dev:
>   	kfree(brd);
> -out:
> -	return NULL;
> -}
> -
> -static void brd_free(struct brd_device *brd)
> -{
> -	put_disk(brd->brd_disk);
> -	blk_cleanup_queue(brd->brd_queue);
> -	brd_free_pages(brd);
> -	kfree(brd);
> +	return -ENOMEM;
>   }
>   
>   static void brd_probe(dev_t dev)
>   {
> -	struct brd_device *brd;
>   	int i = MINOR(dev) / max_part;
> +	struct brd_device *brd;
>   
>   	mutex_lock(&brd_devices_mutex);
>   	list_for_each_entry(brd, &brd_devices, brd_list) {
> @@ -445,13 +434,7 @@ static void brd_probe(dev_t dev)
>   			goto out_unlock;
>   	}
>   
> -	brd = brd_alloc(i);
> -	if (brd) {
> -		brd->brd_disk->queue = brd->brd_queue;
> -		add_disk(brd->brd_disk);
> -		list_add_tail(&brd->brd_list, &brd_devices);
> -	}
> -
> +	brd_alloc(i);
>   out_unlock:
>   	mutex_unlock(&brd_devices_mutex);
>   }
> @@ -460,7 +443,9 @@ static void brd_del_one(struct brd_device *brd)
>   {
>   	list_del(&brd->brd_list);
>   	del_gendisk(brd->brd_disk);
> -	brd_free(brd);
> +	blk_cleanup_disk(brd->brd_disk);
> +	brd_free_pages(brd);
> +	kfree(brd);
>   }
>   
>   static inline void brd_check_and_reset_par(void)
> @@ -485,7 +470,7 @@ static inline void brd_check_and_reset_par(void)
>   static int __init brd_init(void)
>   {
>   	struct brd_device *brd, *next;
> -	int i;
> +	int err, i;
>   
>   	/*
>   	 * brd module now has a feature to instantiate underlying device
> @@ -511,22 +496,11 @@ static int __init brd_init(void)
>   
>   	mutex_lock(&brd_devices_mutex);
>   	for (i = 0; i < rd_nr; i++) {
> -		brd = brd_alloc(i);
> -		if (!brd)
> +		err = brd_alloc(i);
> +		if (err)
>   			goto out_free;
> -		list_add_tail(&brd->brd_list, &brd_devices);
>   	}
>   
> -	/* point of no return */
> -
> -	list_for_each_entry(brd, &brd_devices, brd_list) {
> -		/*
> -		 * associate with queue just before adding disk for
> -		 * avoiding to mess up failure path
> -		 */
> -		brd->brd_disk->queue = brd->brd_queue;
> -		add_disk(brd->brd_disk);
> -	}
>   	mutex_unlock(&brd_devices_mutex);
>   
>   	pr_info("brd: module loaded\n");
> @@ -535,15 +509,13 @@ static int __init brd_init(void)
>   out_free:
>   	debugfs_remove_recursive(brd_debugfs_dir);
>   
> -	list_for_each_entry_safe(brd, next, &brd_devices, brd_list) {
> -		list_del(&brd->brd_list);
> -		brd_free(brd);
> -	}
> +	list_for_each_entry_safe(brd, next, &brd_devices, brd_list)
> +		brd_del_one(brd);
>   	mutex_unlock(&brd_devices_mutex);
>   	unregister_blkdev(RAMDISK_MAJOR, "ramdisk");
>   
>   	pr_info("brd: module NOT loaded !!!\n");
> -	return -ENOMEM;
> +	return err;
>   }
>   
>   static void __exit brd_exit(void)
> 
Other than that:

Reviewed-by: Hannes Reinecke <hare@suse.de>

Cheers,

Hannes
Christoph Hellwig May 24, 2021, 7:24 a.m. UTC | #2
On Sun, May 23, 2021 at 09:58:48AM +0200, Hannes Reinecke wrote:
>> +	/*
>> +	 * This is so fdisk will align partitions on 4k, because of
>> +	 * direct_access API needing 4k alignment, returning a PFN
>> +	 * (This is only a problem on very small devices <= 4M,
>> +	 *  otherwise fdisk will align on 1M. Regardless this call
>> +	 *  is harmless)
>> +	 */
>> +	blk_queue_physical_block_size(disk->queue, PAGE_SIZE);
>>   
>
> Maybe converting the comment to refer to 'PAGE_SIZE' instead of 4k while 
> you're at it ...

I really do not want to touch these kinds of unrelated things here.
diff mbox series

Patch

diff --git a/drivers/block/brd.c b/drivers/block/brd.c
index 7562cf30b14e..95694113e38e 100644
--- a/drivers/block/brd.c
+++ b/drivers/block/brd.c
@@ -38,9 +38,7 @@ 
  * device).
  */
 struct brd_device {
-	int		brd_number;
-
-	struct request_queue	*brd_queue;
+	int			brd_number;
 	struct gendisk		*brd_disk;
 	struct list_head	brd_list;
 
@@ -372,7 +370,7 @@  static LIST_HEAD(brd_devices);
 static DEFINE_MUTEX(brd_devices_mutex);
 static struct dentry *brd_debugfs_dir;
 
-static struct brd_device *brd_alloc(int i)
+static int brd_alloc(int i)
 {
 	struct brd_device *brd;
 	struct gendisk *disk;
@@ -380,64 +378,55 @@  static struct brd_device *brd_alloc(int i)
 
 	brd = kzalloc(sizeof(*brd), GFP_KERNEL);
 	if (!brd)
-		goto out;
+		return -ENOMEM;
 	brd->brd_number		= i;
 	spin_lock_init(&brd->brd_lock);
 	INIT_RADIX_TREE(&brd->brd_pages, GFP_ATOMIC);
 
-	brd->brd_queue = blk_alloc_queue(NUMA_NO_NODE);
-	if (!brd->brd_queue)
-		goto out_free_dev;
-
 	snprintf(buf, DISK_NAME_LEN, "ram%d", i);
 	if (!IS_ERR_OR_NULL(brd_debugfs_dir))
 		debugfs_create_u64(buf, 0444, brd_debugfs_dir,
 				&brd->brd_nr_pages);
 
-	/* This is so fdisk will align partitions on 4k, because of
-	 * direct_access API needing 4k alignment, returning a PFN
-	 * (This is only a problem on very small devices <= 4M,
-	 *  otherwise fdisk will align on 1M. Regardless this call
-	 *  is harmless)
-	 */
-	blk_queue_physical_block_size(brd->brd_queue, PAGE_SIZE);
-	disk = brd->brd_disk = alloc_disk(max_part);
+	disk = brd->brd_disk = blk_alloc_disk(NUMA_NO_NODE);
 	if (!disk)
-		goto out_free_queue;
+		goto out_free_dev;
+
 	disk->major		= RAMDISK_MAJOR;
 	disk->first_minor	= i * max_part;
+	disk->minors		= max_part;
 	disk->fops		= &brd_fops;
 	disk->private_data	= brd;
 	disk->flags		= GENHD_FL_EXT_DEVT;
 	strlcpy(disk->disk_name, buf, DISK_NAME_LEN);
 	set_capacity(disk, rd_size * 2);
+	
+	/*
+	 * This is so fdisk will align partitions on 4k, because of
+	 * direct_access API needing 4k alignment, returning a PFN
+	 * (This is only a problem on very small devices <= 4M,
+	 *  otherwise fdisk will align on 1M. Regardless this call
+	 *  is harmless)
+	 */
+	blk_queue_physical_block_size(disk->queue, PAGE_SIZE);
 
 	/* Tell the block layer that this is not a rotational device */
-	blk_queue_flag_set(QUEUE_FLAG_NONROT, brd->brd_queue);
-	blk_queue_flag_clear(QUEUE_FLAG_ADD_RANDOM, brd->brd_queue);
+	blk_queue_flag_set(QUEUE_FLAG_NONROT, disk->queue);
+	blk_queue_flag_clear(QUEUE_FLAG_ADD_RANDOM, disk->queue);
+	add_disk(disk);
+	list_add_tail(&brd->brd_list, &brd_devices);
 
-	return brd;
+	return 0;
 
-out_free_queue:
-	blk_cleanup_queue(brd->brd_queue);
 out_free_dev:
 	kfree(brd);
-out:
-	return NULL;
-}
-
-static void brd_free(struct brd_device *brd)
-{
-	put_disk(brd->brd_disk);
-	blk_cleanup_queue(brd->brd_queue);
-	brd_free_pages(brd);
-	kfree(brd);
+	return -ENOMEM;
 }
 
 static void brd_probe(dev_t dev)
 {
-	struct brd_device *brd;
 	int i = MINOR(dev) / max_part;
+	struct brd_device *brd;
 
 	mutex_lock(&brd_devices_mutex);
 	list_for_each_entry(brd, &brd_devices, brd_list) {
@@ -445,13 +434,7 @@  static void brd_probe(dev_t dev)
 			goto out_unlock;
 	}
 
-	brd = brd_alloc(i);
-	if (brd) {
-		brd->brd_disk->queue = brd->brd_queue;
-		add_disk(brd->brd_disk);
-		list_add_tail(&brd->brd_list, &brd_devices);
-	}
-
+	brd_alloc(i);
 out_unlock:
 	mutex_unlock(&brd_devices_mutex);
 }
@@ -460,7 +443,9 @@  static void brd_del_one(struct brd_device *brd)
 {
 	list_del(&brd->brd_list);
 	del_gendisk(brd->brd_disk);
-	brd_free(brd);
+	blk_cleanup_disk(brd->brd_disk);
+	brd_free_pages(brd);
+	kfree(brd);
 }
 
 static inline void brd_check_and_reset_par(void)
@@ -485,7 +470,7 @@  static inline void brd_check_and_reset_par(void)
 static int __init brd_init(void)
 {
 	struct brd_device *brd, *next;
-	int i;
+	int err, i;
 
 	/*
 	 * brd module now has a feature to instantiate underlying device
@@ -511,22 +496,11 @@  static int __init brd_init(void)
 
 	mutex_lock(&brd_devices_mutex);
 	for (i = 0; i < rd_nr; i++) {
-		brd = brd_alloc(i);
-		if (!brd)
+		err = brd_alloc(i);
+		if (err)
 			goto out_free;
-		list_add_tail(&brd->brd_list, &brd_devices);
 	}
 
-	/* point of no return */
-
-	list_for_each_entry(brd, &brd_devices, brd_list) {
-		/*
-		 * associate with queue just before adding disk for
-		 * avoiding to mess up failure path
-		 */
-		brd->brd_disk->queue = brd->brd_queue;
-		add_disk(brd->brd_disk);
-	}
 	mutex_unlock(&brd_devices_mutex);
 
 	pr_info("brd: module loaded\n");
@@ -535,15 +509,13 @@  static int __init brd_init(void)
 out_free:
 	debugfs_remove_recursive(brd_debugfs_dir);
 
-	list_for_each_entry_safe(brd, next, &brd_devices, brd_list) {
-		list_del(&brd->brd_list);
-		brd_free(brd);
-	}
+	list_for_each_entry_safe(brd, next, &brd_devices, brd_list)
+		brd_del_one(brd);
 	mutex_unlock(&brd_devices_mutex);
 	unregister_blkdev(RAMDISK_MAJOR, "ramdisk");
 
 	pr_info("brd: module NOT loaded !!!\n");
-	return -ENOMEM;
+	return err;
 }
 
 static void __exit brd_exit(void)