Re: [PATCH 3/5] block: move rescan_partitions to fs/block_dev.c

[Hannes Reinecke <hare@suse.de>]

On 11/6/19 4:14 PM, Christoph Hellwig wrote:
> Large parts of rescan_partitions aren't about partitions, and
> moving it to block_dev.c will allow for some further cleanups by
> merging it into its only caller.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>  block/partition-generic.c | 37 ++-----------------------------------
>  fs/block_dev.c            | 38 ++++++++++++++++++++++++++++++++++++--
>  include/linux/fs.h        |  2 --
>  include/linux/genhd.h     |  4 ++--
>  4 files changed, 40 insertions(+), 41 deletions(-)
> 
> diff --git a/block/partition-generic.c b/block/partition-generic.c
> index eae9daa8a523..7a6e406ac490 100644
> --- a/block/partition-generic.c
> +++ b/block/partition-generic.c
> @@ -439,7 +439,7 @@ static bool disk_unlock_native_capacity(struct gendisk *disk)
>  	}
>  }
>  
> -static int drop_partitions(struct gendisk *disk, struct block_device *bdev)
> +int blk_drop_partitions(struct gendisk *disk, struct block_device *bdev)
>  {
>  	struct disk_part_iter piter;
>  	struct hd_struct *part;
> @@ -573,7 +573,7 @@ static bool blk_add_partition(struct gendisk *disk, struct block_device *bdev,
>  	return true;
>  }
>  
> -static int blk_add_partitions(struct gendisk *disk, struct block_device *bdev)
> +int blk_add_partitions(struct gendisk *disk, struct block_device *bdev)
>  {
>  	struct parsed_partitions *state;
>  	int ret = -EAGAIN, p, highest;
> @@ -632,39 +632,6 @@ static int blk_add_partitions(struct gendisk *disk, struct block_device *bdev)
>  	return ret;
>  }
>  
> -int rescan_partitions(struct gendisk *disk, struct block_device *bdev,
> -		bool invalidate)
> -{
> -	int ret;
> -
> -rescan:
> -	ret = drop_partitions(disk, bdev);
> -	if (ret)
> -		return ret;
> -
> -	if (invalidate)
> -		set_capacity(disk, 0);
> -	else if (disk->fops->revalidate_disk)
> -		disk->fops->revalidate_disk(disk);
> -
> -	check_disk_size_change(disk, bdev, !invalidate);
> -	bdev->bd_invalidated = 0;
> -
> -	if (!get_capacity(disk)) {
> -		/*
> -		 * Tell userspace that the media / partition table may have
> -		 * changed.
> -		 */
> -		kobject_uevent(&disk_to_dev(disk)->kobj, KOBJ_CHANGE);
> -		return 0;
> -	}
> -	
> -	ret = blk_add_partitions(disk, bdev);
> -	if (ret == -EAGAIN)
> -		goto rescan;
> -	return ret;
> -}
> -
>  unsigned char *read_dev_sector(struct block_device *bdev, sector_t n, Sector *p)
>  {
>  	struct address_space *mapping = bdev->bd_inode->i_mapping;
> diff --git a/fs/block_dev.c b/fs/block_dev.c
> index 0af62b76d031..f0710085e1f1 100644
> --- a/fs/block_dev.c
> +++ b/fs/block_dev.c
> @@ -1416,8 +1416,8 @@ static void flush_disk(struct block_device *bdev, bool kill_dirty)
>   * and adjusts it if it differs. When shrinking the bdev size, its all caches
>   * are freed.
>   */
> -void check_disk_size_change(struct gendisk *disk, struct block_device *bdev,
> -		bool verbose)
> +static void check_disk_size_change(struct gendisk *disk,
> +		struct block_device *bdev, bool verbose)
>  {
>  	loff_t disk_size, bdev_size;
>  
> @@ -1508,6 +1508,40 @@ EXPORT_SYMBOL(bd_set_size);
>  
>  static void __blkdev_put(struct block_device *bdev, fmode_t mode, int for_part);
>  
> +static int rescan_partitions(struct gendisk *disk, struct block_device *bdev,
> +		bool invalidate)
> +{
> +	int ret;
> +
> +rescan:
> +	ret = blk_drop_partitions(disk, bdev);
> +	if (ret)
> +		return ret;
> +
> +	if (invalidate)
> +		set_capacity(disk, 0);
> +	else if (disk->fops->revalidate_disk)
> +		disk->fops->revalidate_disk(disk);
> +
> +	check_disk_size_change(disk, bdev, !invalidate);
> +	bdev->bd_invalidated = 0;
> +
> +	if (!get_capacity(disk)) {
> +		/*
> +		 * Tell userspace that the media / partition table may have
> +		 * changed.
> +		 */
> +		kobject_uevent(&disk_to_dev(disk)->kobj, KOBJ_CHANGE);
> +		return 0;
> +	}
> +	
> +	ret = blk_add_partitions(disk, bdev);
> +	if (ret == -EAGAIN)
> +		goto rescan;
> +	return ret;
> +}
> +
> +
>  static void bdev_disk_changed(struct block_device *bdev, bool invalidate)
>  {
>  	if (disk_part_scan_enabled(bdev->bd_disk)) {

... see my comments in the previous patch to drop get_capacity() and
have check_disk_size_change() return bool ...

Cheers,

Hannes
-- 
Dr. Hannes Reinecke		      Teamlead Storage & Networking
hare@suse.de			                  +49 911 74053 688
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