[SCSI] Generate uevents on certain unit attention codes

Generate a uevent when the following Unit Attention ASC/ASCQ
codes are received:

    2A/01  MODE PARAMETERS CHANGED
    2A/09  CAPACITY DATA HAS CHANGED
    38/07  THIN PROVISIONING SOFT THRESHOLD REACHED
    3F/03  INQUIRY DATA HAS CHANGED
    3F/0E  REPORTED LUNS DATA HAS CHANGED

Log kernel messages when the following Unit Attention ASC/ASCQ
codes are received that are not as specific as those above:

    2A/xx  PARAMETERS CHANGED
    3F/xx  TARGET OPERATING CONDITIONS HAVE CHANGED

Added logic to set expecting_lun_change for other LUNs on the target
after REPORTED LUNS DATA HAS CHANGED is received, so that duplicate
uevents are not generated, and clear expecting_lun_change when a
REPORT LUNS command completes, in accordance with the SPC-3
specification regarding reporting of the 3F 0E ASC/ASCQ UA.

[jejb: remove SPC3 test in scsi_report_lun_change and some docbook fixes and
       unused variable fix, both reported by Fengguang Wu]
Signed-off-by: Ewan D. Milne <emilne@redhat.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

1 files changed, 12 insertions, 1 deletions

diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h
index a44954c7cdc2..d65fbec2533d 100644
--- a/include/scsi/scsi_device.h
+++ b/include/scsi/scsi_device.h
@@ -52,8 +52,15 @@ enum scsi_device_state {
 
 enum scsi_device_event {
         SDEV_EVT_MEDIA_CHANGE   = 1,    /* media has changed */
+        SDEV_EVT_INQUIRY_CHANGE_REPORTED,               /* 3F 03  UA reported */
+        SDEV_EVT_CAPACITY_CHANGE_REPORTED,              /* 2A 09  UA reported */
+        SDEV_EVT_SOFT_THRESHOLD_REACHED_REPORTED,       /* 38 07  UA reported */
+        SDEV_EVT_MODE_PARAMETER_CHANGE_REPORTED,        /* 2A 01  UA reported */
+        SDEV_EVT_LUN_CHANGE_REPORTED,                   /* 3F 0E  UA reported */
+
+        SDEV_EVT_FIRST          = SDEV_EVT_MEDIA_CHANGE,
+        SDEV_EVT_LAST           = SDEV_EVT_LUN_CHANGE_REPORTED,
 
-        SDEV_EVT_LAST           = SDEV_EVT_MEDIA_CHANGE,
         SDEV_EVT_MAXBITS        = SDEV_EVT_LAST + 1
 };
 
@@ -164,6 +171,7 @@ struct scsi_device {
         atomic_t disk_events_disable_depth; /* disable depth for disk events */
 
         DECLARE_BITMAP(supported_events, SDEV_EVT_MAXBITS); /* supported events */
+        DECLARE_BITMAP(pending_events, SDEV_EVT_MAXBITS); /* pending events */
         struct list_head event_list;    /* asserted events */
         struct work_struct event_work;
 
@@ -261,6 +269,9 @@ struct scsi_target {
                                                  * means no lun present. */
         unsigned int            no_report_luns:1;       /* Don't use
                                                  * REPORT LUNS for scanning. */
+        unsigned int            expecting_lun_change:1; /* A device has reported
+                                                 * a 3F/0E UA, other devices on
+                                                 * the same target will also. */
         /* commands actually active on LLD. protected by host lock. */
         unsigned int            target_busy;
         /*