cdrom: protect cdrom_device_info list by mutex

This patch protects the list of cdrom_device_info by cdrom_mutex
when the file in /proc/sys/dev/cdrom/ is written.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/drivers/cdrom/cdrom.c b/drivers/cdrom/cdrom.c
index fbcf4b3f8d0..326ef1b4a4e 100644
--- a/drivers/cdrom/cdrom.c
+++ b/drivers/cdrom/cdrom.c
@@ -3427,6 +3427,7 @@ static void cdrom_update_settings(void)
 {
         struct cdrom_device_info *cdi;
 
+        mutex_lock(&cdrom_mutex);
         for (cdi = topCdromPtr; cdi != NULL; cdi = cdi->next) {
                 if (autoclose && CDROM_CAN(CDC_CLOSE_TRAY))
                         cdi->options |= CDO_AUTO_CLOSE;
@@ -3445,6 +3446,7 @@ static void cdrom_update_settings(void)
                 else
                         cdi->options &= ~CDO_CHECK_TYPE;
         }
+        mutex_unlock(&cdrom_mutex);
 }
 
 static int cdrom_sysctl_handler(ctl_table *ctl, int write, struct file * filp,