Re: [PATCH 3/7] cdrom: factor out a cdrom_read_tocentry helper

From: Damien Le Moal
Date: Thu Apr 23 2020 - 03:41:26 EST


On 2020/04/23 16:15, Christoph Hellwig wrote:
> Factor out a version of the CDROMREADTOCENTRY ioctl handler that can
> be called directly from kernel space.
>
> Signed-off-by: Christoph Hellwig <hch@xxxxxx>
> ---
> drivers/cdrom/cdrom.c | 39 ++++++++++++++++++++++-----------------
> include/linux/cdrom.h | 3 +++
> 2 files changed, 25 insertions(+), 17 deletions(-)
>
> diff --git a/drivers/cdrom/cdrom.c b/drivers/cdrom/cdrom.c
> index a1d2112fd283..c91d1e138214 100644
> --- a/drivers/cdrom/cdrom.c
> +++ b/drivers/cdrom/cdrom.c
> @@ -2666,32 +2666,37 @@ static int cdrom_ioctl_read_tochdr(struct cdrom_device_info *cdi,
> return 0;
> }
>
> +int cdrom_read_tocentry(struct cdrom_device_info *cdi,
> + struct cdrom_tocentry *entry)
> +{
> + u8 requested_format = entry->cdte_format;
> + int ret;
> +
> + if (requested_format != CDROM_MSF && requested_format != CDROM_LBA)
> + return -EINVAL;
> +
> + /* make interface to low-level uniform */
> + entry->cdte_format = CDROM_MSF;
> + ret = cdi->ops->audio_ioctl(cdi, CDROMREADTOCENTRY, entry);
> + if (!ret)
> + sanitize_format(&entry->cdte_addr, &entry->cdte_format,
> + requested_format);
> + return ret;
> +}
> +EXPORT_SYMBOL_GPL(cdrom_read_tocentry);
> +
> static int cdrom_ioctl_read_tocentry(struct cdrom_device_info *cdi,
> void __user *argp)
> {
> struct cdrom_tocentry entry;
> - u8 requested_format;
> int ret;
>
> - /* cd_dbg(CD_DO_IOCTL, "entering CDROMREADTOCENTRY\n"); */
> -
> if (copy_from_user(&entry, argp, sizeof(entry)))
> return -EFAULT;
> -
> - requested_format = entry.cdte_format;
> - if (requested_format != CDROM_MSF && requested_format != CDROM_LBA)
> - return -EINVAL;
> - /* make interface to low-level uniform */
> - entry.cdte_format = CDROM_MSF;
> - ret = cdi->ops->audio_ioctl(cdi, CDROMREADTOCENTRY, &entry);
> - if (ret)
> - return ret;
> - sanitize_format(&entry.cdte_addr, &entry.cdte_format, requested_format);
> -
> - if (copy_to_user(argp, &entry, sizeof(entry)))
> + ret = cdrom_read_tocentry(cdi, &entry);
> + if (!ret && copy_to_user(argp, &entry, sizeof(entry)))
> return -EFAULT;
> - /* cd_dbg(CD_DO_IOCTL, "CDROMREADTOCENTRY successful\n"); */
> - return 0;
> + return ret;
> }
>
> static int cdrom_ioctl_play_msf(struct cdrom_device_info *cdi,
> diff --git a/include/linux/cdrom.h b/include/linux/cdrom.h
> index 4f74ce050253..008c4d79fa33 100644
> --- a/include/linux/cdrom.h
> +++ b/include/linux/cdrom.h
> @@ -94,6 +94,9 @@ struct cdrom_device_ops {
> struct packet_command *);
> };
>
> +int cdrom_read_tocentry(struct cdrom_device_info *cdi,
> + struct cdrom_tocentry *entry);
> +
> /* the general block_device operations structure: */
> extern int cdrom_open(struct cdrom_device_info *cdi, struct block_device *bdev,
> fmode_t mode);
>

Looks OK to me.

Reviewed-by: Damien Le Moal <damien.lemoal@xxxxxxx>


--
Damien Le Moal
Western Digital Research