cdrom: add ->check_events() support

In principle, cdrom just needs to pass through ->check_events() but
CDROM_MEDIA_CHANGED ioctl makes things a bit more complex.  Just as
with ->media_changed() support, cdrom code needs to buffer the events
and serve them to ioctl and vfs as requested.

As the code has to deal with both ->check_events() and
->media_changed(), and vfs and ioctl event buffering, this patch adds
check_events caching on top of the existing cdi->mc_flags buffering.

It may be a good idea to deprecate CDROM_MEDIA_CHANGED ioctl and
remove all this mess.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/include/linux/cdrom.h b/include/linux/cdrom.h
index 78e904796622..35eae4b67503 100644
--- a/include/linux/cdrom.h
+++ b/include/linux/cdrom.h
@@ -946,6 +946,8 @@ struct cdrom_device_info {
 /* device-related storage */
         unsigned int options    : 30;   /* options flags */
         unsigned mc_flags       : 2;    /* media change buffer flags */
+        unsigned int vfs_events;        /* cached events for vfs path */
+        unsigned int ioctl_events;      /* cached events for ioctl path */
         int use_count;                  /* number of times device opened */
         char name[20];                  /* name of the device type */
 /* per-device flags */
@@ -965,6 +967,8 @@ struct cdrom_device_ops {
         int (*open) (struct cdrom_device_info *, int);
         void (*release) (struct cdrom_device_info *);
         int (*drive_status) (struct cdrom_device_info *, int);
+        unsigned int (*check_events) (struct cdrom_device_info *cdi,
+                                      unsigned int clearing, int slot);
         int (*media_changed) (struct cdrom_device_info *, int);
         int (*tray_move) (struct cdrom_device_info *, int);
         int (*lock_door) (struct cdrom_device_info *, int);
@@ -993,6 +997,8 @@ extern int cdrom_open(struct cdrom_device_info *cdi, struct block_device *bdev,
 extern void cdrom_release(struct cdrom_device_info *cdi, fmode_t mode);
 extern int cdrom_ioctl(struct cdrom_device_info *cdi, struct block_device *bdev,
                        fmode_t mode, unsigned int cmd, unsigned long arg);
+extern unsigned int cdrom_check_events(struct cdrom_device_info *cdi,
+                                       unsigned int clearing);
 extern int cdrom_media_changed(struct cdrom_device_info *);
 
 extern int register_cdrom(struct cdrom_device_info *cdi);