[SCSI] sr,sd: send media state change modification events

This will send for a card reader slot (remove/add media):
  UEVENT[1187091572.155884] change   /devices/pci0000:00/0000:00:1d.7/usb5/5-2/5-2:1.0/host7/target7:0:0/7:0:0:0 (scsi)
  UEVENT[1187091572.162314] remove   /block/sdb/sdb1 (block)
  UEVENT[1187091572.172464] add      /block/sdb/sdb1 (block)
  UEVENT[1187091572.175408] change   /devices/pci0000:00/0000:00:1d.7/usb5/5-2/5-2:1.0/host7/target7:0:0/7:0:0:0 (scsi)

and for a DVD drive (add/eject media):
  UEVENT[1187091590.189159] change   /devices/pci0000:00/0000:00:1f.1/host4/target4:0:0/4:0:0:0 (scsi)
  UEVENT[1187091590.957124] add      /module/isofs (module)
  UEVENT[1187091604.468207] change   /devices/pci0000:00/0000:00:1f.1/host4/target4:0:0/4:0:0:0 (scsi)

Userspace gets events, even for unpartitioned media. This unifies
the event handling for asynchronoous events (AN) and events caused by
perodical polling the device from userspace.

Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>

[jejb: modified for new event API]

Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

1 files changed, 11 insertions, 3 deletions

diff --git a/drivers/scsi/sr.c b/drivers/scsi/sr.c
index c61999031141..7702681d93f9 100644
--- a/drivers/scsi/sr.c
+++ b/drivers/scsi/sr.c
@@ -192,8 +192,9 @@ static int sr_media_change(struct cdrom_device_info *cdi, int slot)
                  * and we will figure it out later once the drive is
                  * available again.  */
                 cd->device->changed = 1;
-                return 1;       /* This will force a flush, if called from
-                                 * check_disk_change */
+                /* This will force a flush, if called from check_disk_change */
+                retval = 1;
+                goto out;
         };
 
         retval = cd->device->changed;
@@ -203,9 +204,16 @@ static int sr_media_change(struct cdrom_device_info *cdi, int slot)
         if (retval) {
                 /* check multisession offset etc */
                 sr_cd_check(cdi);
-
                 get_sectorsize(cd);
         }
+
+out:
+        /* Notify userspace, that media has changed. */
+        if (retval != cd->previous_state)
+                sdev_evt_send_simple(cd->device, SDEV_EVT_MEDIA_CHANGE,
+                                     GFP_KERNEL);
+        cd->previous_state = retval;
+
         return retval;
 }