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 <hch@lst.de>
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/drivers/cdrom/cdrom.c b/drivers/cdrom/cdrom.c
index c91d1e1..06896c0 100644 (file)
--- a/drivers/cdrom/cdrom.c
+++ b/drivers/cdrom/cdrom.c
@@ -2295,37 +2295,46 @@ retry:
        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 008c4d7..8543fa5 100644 (file)
--- 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);