[PATCH v2 05/35] fs: super: introduce a get_super_cdev to get super by a cdev reference

[Jan Kara]

On Thu 30-07-15 13:48:01, Dongsheng Yang wrote:
> As we have cdev in superblock now, we can provide get_super_cdev
> to get super_block by a cdev reference, similar with get_super
> which is working only for block_device.

The patch looks good to me. You can add:

Reviewed-by: Jan Kara <jack at suse.com>

								Honza

> 
> Signed-off-by: Dongsheng Yang <yangds.fnst at cn.fujitsu.com>
> ---
>  fs/super.c         | 15 +++++++++++++++
>  include/linux/fs.h |  1 +
>  2 files changed, 16 insertions(+)
> 
> diff --git a/fs/super.c b/fs/super.c
> index 46fd1f1..4c56dff 100644
> --- a/fs/super.c
> +++ b/fs/super.c
> @@ -613,6 +613,21 @@ struct super_block *get_super(struct block_device *bdev)
>  }
>  EXPORT_SYMBOL(get_super);
>  
> +static int cdev_compare(struct super_block *sb, void *key)
> +{
> +	return (sb->s_cdev == (struct cdev *)key);
> +}
> +
> +/**
> + * get_super_cdev - get the superblock of a cdev
> + * @cdev: char device to get the superblock for
> + */
> +struct super_block *get_super_cdev(struct cdev *cdev)
> +{
> +	return __get_super(cdev_compare, cdev);
> +}
> +EXPORT_SYMBOL(get_super_cdev);
> +
>  /**
>   * get_super_thawed - get thawed superblock of a device
>   * @bdev: device to get the superblock for
> diff --git a/include/linux/fs.h b/include/linux/fs.h
> index 2f1d9499..e5ea425a 100644
> --- a/include/linux/fs.h
> +++ b/include/linux/fs.h
> @@ -2744,6 +2744,7 @@ extern void get_filesystem(struct file_system_type *fs);
>  extern void put_filesystem(struct file_system_type *fs);
>  extern struct file_system_type *get_fs_type(const char *name);
>  extern struct super_block *get_super(struct block_device *);
> +extern struct super_block *get_super_cdev(struct cdev *);
>  extern struct super_block *get_super_thawed(struct block_device *);
>  extern struct super_block *get_active_super(struct block_device *bdev);
>  extern void drop_super(struct super_block *sb);
> -- 
> 1.8.4.2
> 
-- 
Jan Kara <jack at suse.com>
SUSE Labs, CR