[PATCH 2/3] mtd: ubiblock: introduce ubiblock_create_dev

[Boris Brezillon]

On Sat, 27 Aug 2016 21:44:16 +0200
Daniel Golle <daniel at makrotopia.org> wrote:

> Define function ubiblock_create_dev(char *name, dev_t *bdev)
> which returns the created device by setting the point bdev.
> This is useful for in-kernel users creating a ubiblock device
> in order to mount the root filesystem.

No specific comment on this one either, since it's only preparing stuff
for the real changes done in patch 3.

> 
> Signed-off-by: Daniel Golle <daniel at makrotopia.org>
> ---
>  drivers/mtd/ubi/block.c | 11 ++++++++++-
>  drivers/mtd/ubi/ubi.h   |  2 ++
>  include/linux/mtd/ubi.h | 16 ++++++++++++++++
>  3 files changed, 28 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/mtd/ubi/block.c b/drivers/mtd/ubi/block.c
> index ebf46ad..58b818f 100644
> --- a/drivers/mtd/ubi/block.c
> +++ b/drivers/mtd/ubi/block.c
> @@ -49,6 +49,7 @@
>  #include <linux/hdreg.h>
>  #include <linux/scatterlist.h>
>  #include <linux/idr.h>
> +#include <linux/kdev_t.h>
>  #include <asm/div64.h>
>  
>  #include "ubi-media.h"
> @@ -356,7 +357,11 @@ static struct blk_mq_ops ubiblock_mq_ops = {
>  
>  static DEFINE_IDR(ubiblock_minor_idr);
>  
> -int ubiblock_create(struct ubi_volume_info *vi)
> +int ubiblock_create(struct ubi_volume_info *vi) {
> +	return ubiblock_create_dev(vi, NULL);
> +}
> +
> +int ubiblock_create_dev(struct ubi_volume_info *vi, dev_t *bdev)
>  {
>  	struct ubiblock *dev;
>  	struct gendisk *gd;
> @@ -448,6 +453,10 @@ int ubiblock_create(struct ubi_volume_info *vi)
>  	add_disk(dev->gd);
>  	dev_info(disk_to_dev(dev->gd), "created from ubi%d:%d(%s)",
>  		 dev->ubi_num, dev->vol_id, vi->name);
> +
> +	if (bdev)
> +		*bdev = MKDEV(gd->major, gd->first_minor);
> +
>  	return 0;
>  
>  out_free_queue:
> diff --git a/drivers/mtd/ubi/ubi.h b/drivers/mtd/ubi/ubi.h
> index de1ea2e4..7700752 100644
> --- a/drivers/mtd/ubi/ubi.h
> +++ b/drivers/mtd/ubi/ubi.h
> @@ -39,6 +39,7 @@
>  #include <linux/notifier.h>
>  #include <linux/mtd/mtd.h>
>  #include <linux/mtd/ubi.h>
> +#include <linux/kdev_t.h>
>  #include <asm/pgtable.h>
>  
>  #include "ubi-media.h"
> @@ -917,6 +918,7 @@ static inline int ubi_update_fastmap(struct ubi_device *ubi) { return 0; }
>  int ubiblock_init(void);
>  void ubiblock_exit(void);
>  int ubiblock_create(struct ubi_volume_info *vi);
> +int ubiblock_create_dev(struct ubi_volume_info *vi, dev_t *bdev);
>  int ubiblock_remove(struct ubi_volume_info *vi);
>  #else
>  static inline int ubiblock_init(void) { return 0; }
> diff --git a/include/linux/mtd/ubi.h b/include/linux/mtd/ubi.h
> index 0b92aa5..3d6444f 100644
> --- a/include/linux/mtd/ubi.h
> +++ b/include/linux/mtd/ubi.h
> @@ -21,7 +21,9 @@
>  #ifndef __LINUX_UBI_H__
>  #define __LINUX_UBI_H__
>  
> +#include <linux/errno.h>
>  #include <linux/ioctl.h>
> +#include <linux/kdev_t.h>
>  #include <linux/types.h>
>  #include <linux/scatterlist.h>
>  #include <mtd/ubi-user.h>
> @@ -282,4 +284,18 @@ static inline int ubi_read_sg(struct ubi_volume_desc *desc, int lnum,
>  {
>  	return ubi_leb_read_sg(desc, lnum, sgl, offset, len, 0);
>  }
> +
> +
> +/*
> + * This function allows in-kernel users to create a ubiblock device and
> + * get to know about the created device.
> + */
> +#ifdef CONFIG_MTD_UBI_BLOCK
> +int ubiblock_create_dev(struct ubi_volume_info *vi, dev_t *bdev);
> +#else
> +int ubiblock_create_dev(struct ubi_volume_info *vi, dev_t *bdev) {
> +	return -ENOTSUPP;
> +}
> +#endif
> +
>  #endif /* !__LINUX_UBI_H__ */