[SCSI] sd,sr: add early detection of medium not present
The current scsi_test_unit_ready() is updated to return sense code
information (in struct scsi_sense_hdr). The sd and sr drivers are
changed to interpret the sense code return asc 0x3a as no media and
adjust the device status accordingly.
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
diff --git a/drivers/scsi/sr.c b/drivers/scsi/sr.c
index 7702681..896be4a 100644
--- a/drivers/scsi/sr.c
+++ b/drivers/scsi/sr.c
@@ -179,18 +179,24 @@
{
struct scsi_cd *cd = cdi->handle;
int retval;
+ struct scsi_sense_hdr *sshdr;
if (CDSL_CURRENT != slot) {
/* no changer support */
return -EINVAL;
}
- retval = scsi_test_unit_ready(cd->device, SR_TIMEOUT, MAX_RETRIES);
- if (retval) {
- /* Unable to test, unit probably not ready. This usually
- * means there is no disc in the drive. Mark as changed,
- * and we will figure it out later once the drive is
- * available again. */
+ sshdr = kzalloc(sizeof(*sshdr), GFP_KERNEL);
+ retval = scsi_test_unit_ready(cd->device, SR_TIMEOUT, MAX_RETRIES,
+ sshdr);
+ if (retval || (scsi_sense_valid(sshdr) &&
+ /* 0x3a is medium not present */
+ sshdr->asc == 0x3a)) {
+ /* Media not present or unable to test, unit probably not
+ * ready. This usually means there is no disc in the drive.
+ * Mark as changed, and we will figure it out later once
+ * the drive is available again.
+ */
cd->device->changed = 1;
/* This will force a flush, if called from check_disk_change */
retval = 1;
@@ -213,6 +219,7 @@
sdev_evt_send_simple(cd->device, SDEV_EVT_MEDIA_CHANGE,
GFP_KERNEL);
cd->previous_state = retval;
+ kfree(sshdr);
return retval;
}