Re: [RFC 04/10] devfs & mtd: add MEMERASE ioctl support

[Sascha Hauer <s.hauer@pengutronix.de>]

On Fri, Oct 26, 2012 at 12:16:36PM +0200, Wolfram Sang wrote:
> To make that, we need to shift mtd_erase before mtd_ioctl.
> ubi-utils need that, especially ubiformat.
> 
> Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
> ---
>  drivers/mtd/core.c |   68 +++++++++++++++++++++++++++-------------------------
>  fs/devfs-core.c    |    3 ++-
>  2 files changed, 37 insertions(+), 34 deletions(-)
> 
> diff --git a/drivers/mtd/core.c b/drivers/mtd/core.c
> index 7c323a1..aca4f13 100644
> --- a/drivers/mtd/core.c
> +++ b/drivers/mtd/core.c
> @@ -114,7 +114,37 @@ static ssize_t mtd_write(struct cdev* cdev, const void *buf, size_t _count,
>  out:
>  	return ret ? ret : _count;
>  }
> -#endif
> +
> +static int mtd_erase(struct cdev *cdev, size_t count, loff_t offset)
> +{
> +	struct mtd_info *mtd = cdev->priv;
> +	struct erase_info erase;
> +	int ret;
> +
> +	memset(&erase, 0, sizeof(erase));
> +	erase.mtd = mtd;
> +	erase.addr = offset;
> +	erase.len = mtd->erasesize;
> +
> +	while (count > 0) {
> +		dev_dbg(cdev->dev, "erase %d %d\n", erase.addr, erase.len);
> +
> +		ret = mtd->block_isbad(mtd, erase.addr);
> +		if (ret > 0) {
> +			printf("Skipping bad block at 0x%08x\n", erase.addr);
> +		} else {
> +			ret = mtd->erase(mtd, &erase);
> +			if (ret)
> +				return ret;
> +		}
> +
> +		erase.addr += mtd->erasesize;
> +		count -= count > mtd->erasesize ? mtd->erasesize : count;
> +	}
> +
> +	return 0;
> +}
> +#endif /* CONFIG_MTD_WRITE */
>  
>  int mtd_ioctl(struct cdev *cdev, int request, void *buf)
>  {
> @@ -125,6 +155,7 @@ int mtd_ioctl(struct cdev *cdev, int request, void *buf)
>  	struct mtd_ecc_stats *ecc = buf;
>  #endif
>  	struct region_info_user *reg = buf;
> +	struct erase_info_user *ei = buf;
>  	loff_t *offset = buf;
>  
>  	switch (request) {
> @@ -137,6 +168,9 @@ int mtd_ioctl(struct cdev *cdev, int request, void *buf)
>  		dev_dbg(cdev->dev, "MEMSETBADBLOCK: 0x%08llx\n", *offset);
>  		ret = mtd->block_markbad(mtd, *offset);
>  		break;
> +	case MEMERASE:
> +		ret = mtd_erase(cdev, ei->length, ei->start + cdev->offset);
> +		break;

Please check this compiles with CONFIG_MTD_WRITE disabled.

>  #endif
>  	case MEMGETINFO:
>  		user->type	= mtd->type;
> @@ -174,38 +208,6 @@ int mtd_ioctl(struct cdev *cdev, int request, void *buf)
>  	return ret;
>  }
>  
> -#ifdef CONFIG_MTD_WRITE
> -static int mtd_erase(struct cdev *cdev, size_t count, loff_t offset)
> -{
> -	struct mtd_info *mtd = cdev->priv;
> -	struct erase_info erase;
> -	int ret;
> -
> -	memset(&erase, 0, sizeof(erase));
> -	erase.mtd = mtd;
> -	erase.addr = offset;
> -	erase.len = mtd->erasesize;
> -
> -	while (count > 0) {
> -		dev_dbg(cdev->dev, "erase %d %d\n", erase.addr, erase.len);
> -
> -		ret = mtd->block_isbad(mtd, erase.addr);
> -		if (ret > 0) {
> -			printf("Skipping bad block at 0x%08x\n", erase.addr);
> -		} else {
> -			ret = mtd->erase(mtd, &erase);
> -			if (ret)
> -				return ret;
> -		}
> -
> -		erase.addr += mtd->erasesize;
> -		count -= count > mtd->erasesize ? mtd->erasesize : count;
> -	}
> -
> -	return 0;
> -}
> -#endif
> -
>  static struct file_operations mtd_ops = {
>  	.read   = mtd_read,
>  #ifdef CONFIG_MTD_WRITE
> diff --git a/fs/devfs-core.c b/fs/devfs-core.c
> index 0d2f75a..262e0a2 100644
> --- a/fs/devfs-core.c
> +++ b/fs/devfs-core.c
> @@ -152,13 +152,14 @@ static int partition_ioctl(struct cdev *cdev, int request, void *buf)
>  		break;
>  #if (defined(CONFIG_NAND_ECC_HW) || defined(CONFIG_NAND_ECC_SOFT))
>  	case ECCGETSTATS:
> +#endif
> +	case MEMERASE:
>  		if (!cdev->ops->ioctl) {
>  			ret = -EINVAL;
>  			break;
>  		}
>  		ret = cdev->ops->ioctl(cdev, request, buf);
>  		break;

Are you sure this works for partitions? I assume you have to take
cdev->offset into account like for example the MEMGETBADBLOCK ioctl
does.

Sascha

-- 
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