2020-04-25 07:59:43

by Christoph Hellwig

Subject: [PATCH 4/7] cdrom: factor out a cdrom_multisession helper

Factor out a version of the CDROMMULTISESSION ioctl handler that can
be called directly from kernel space.

Signed-off-by: Christoph Hellwig <[email protected]>
Reviewed-by: Damien Le Moal <[email protected]>
---
drivers/cdrom/cdrom.c | 41 +++++++++++++++++++++++++----------------
include/linux/cdrom.h | 2 ++
2 files changed, 27 insertions(+), 16 deletions(-)

diff --git a/drivers/cdrom/cdrom.c b/drivers/cdrom/cdrom.c
index c91d1e1382142..06896c07b1333 100644
--- a/drivers/cdrom/cdrom.c
+++ b/drivers/cdrom/cdrom.c
@@ -2295,37 +2295,46 @@ static int cdrom_read_cdda(struct cdrom_device_info *cdi, __u8 __user *ubuf,
return cdrom_read_cdda_old(cdi, ubuf, lba, nframes);
}

-static int cdrom_ioctl_multisession(struct cdrom_device_info *cdi,
- void __user *argp)
+int cdrom_multisession(struct cdrom_device_info *cdi,
+ struct cdrom_multisession *info)
{
- struct cdrom_multisession ms_info;
u8 requested_format;
int ret;

- cd_dbg(CD_DO_IOCTL, "entering CDROMMULTISESSION\n");
-
if (!(cdi->ops->capability & CDC_MULTI_SESSION))
return -ENOSYS;

- if (copy_from_user(&ms_info, argp, sizeof(ms_info)))
- return -EFAULT;
-
- requested_format = ms_info.addr_format;
+ requested_format = info->addr_format;
if (requested_format != CDROM_MSF && requested_format != CDROM_LBA)
return -EINVAL;
- ms_info.addr_format = CDROM_LBA;
+ info->addr_format = CDROM_LBA;

- ret = cdi->ops->get_last_session(cdi, &ms_info);
- if (ret)
- return ret;
+ ret = cdi->ops->get_last_session(cdi, info);
+ if (!ret)
+ sanitize_format(&info->addr, &info->addr_format,
+ requested_format);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(cdrom_multisession);

- sanitize_format(&ms_info.addr, &ms_info.addr_format, requested_format);
+static int cdrom_ioctl_multisession(struct cdrom_device_info *cdi,
+ void __user *argp)
+{
+ struct cdrom_multisession info;
+ int ret;
+
+ cd_dbg(CD_DO_IOCTL, "entering CDROMMULTISESSION\n");

- if (copy_to_user(argp, &ms_info, sizeof(ms_info)))
+ if (copy_from_user(&info, argp, sizeof(info)))
+ return -EFAULT;
+ ret = cdrom_multisession(cdi, &info);
+ if (ret)
+ return ret;
+ if (copy_to_user(argp, &info, sizeof(info)))
return -EFAULT;

cd_dbg(CD_DO_IOCTL, "CDROMMULTISESSION successful\n");
- return 0;
+ return ret;
}

static int cdrom_ioctl_eject(struct cdrom_device_info *cdi)
diff --git a/include/linux/cdrom.h b/include/linux/cdrom.h
index 008c4d79fa332..8543fa59da720 100644
--- a/include/linux/cdrom.h
+++ b/include/linux/cdrom.h
@@ -94,6 +94,8 @@ struct cdrom_device_ops {
struct packet_command *);
};

+int cdrom_multisession(struct cdrom_device_info *cdi,
+ struct cdrom_multisession *info);
int cdrom_read_tocentry(struct cdrom_device_info *cdi,
struct cdrom_tocentry *entry);

--
2.26.1

2020-04-27 06:21:42

by Hannes Reinecke

Subject: Re: [PATCH 4/7] cdrom: factor out a cdrom_multisession helper

On 4/25/20 9:57 AM, Christoph Hellwig wrote:
> Factor out a version of the CDROMMULTISESSION ioctl handler that can
> be called directly from kernel space.
>
> Signed-off-by: Christoph Hellwig <[email protected]>
> Reviewed-by: Damien Le Moal <[email protected]>
> ---
> drivers/cdrom/cdrom.c | 41 +++++++++++++++++++++++++----------------
> include/linux/cdrom.h | 2 ++
> 2 files changed, 27 insertions(+), 16 deletions(-)
>
Reviewed-by: Hannes Reinecke <[email protected]>

Cheers,

Hannes
--
Dr. Hannes Reinecke Teamlead Storage & Networking
[email protected] +49 911 74053 688
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