scsi_debug: add Capacity Changed Unit Attention

Via sysfs the virtual_gb scsi_debug parameter can be changed while
LUs are in use. If that changes, the 'Capacity data has changed'
Unit Attention is queued on all LUs.

Signed-off-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c
index d337eaa128d0db7f77ccec956bad6d542713551e..ee99aca92bca2c31e704186da4ba669e2c738834 100644 (file)
--- a/drivers/scsi/scsi_debug.c
+++ b/drivers/scsi/scsi_debug.c
@@ -179,7 +179,8 @@ static const char *scsi_debug_version_date = "20141022";
 #define SDEBUG_UA_POR 0                /* Power on, reset, or bus device reset */
 #define SDEBUG_UA_BUS_RESET 1
 #define SDEBUG_UA_MODE_CHANGED 2
-#define SDEBUG_NUM_UAS 3
+#define SDEBUG_UA_CAPACITY_CHANGED 3
+#define SDEBUG_NUM_UAS 4
 
 /* for check_readiness() */
 #define UAS_ONLY 1
@@ -582,6 +583,11 @@ static int check_readiness(struct scsi_cmnd *SCpnt, int uas_only,
                        if (debug)
                                cp = "mode parameters changed";
                        break;
+               case SDEBUG_UA_CAPACITY_CHANGED:
+                       mk_sense_buffer(SCpnt, UNIT_ATTENTION,
+                                       UA_CHANGED_ASC, CAPACITY_CHANGED_ASCQ);
+                       if (debug)
+                               cp = "capacity data changed";
                default:
                        pr_warn("%s: unexpected unit attention code=%d\n",
                                __func__, k);
@@ -3638,16 +3644,30 @@ static ssize_t virtual_gb_show(struct device_driver *ddp, char *buf)
 {
         return scnprintf(buf, PAGE_SIZE, "%d\n", scsi_debug_virtual_gb);
 }
+
 static ssize_t virtual_gb_store(struct device_driver *ddp, const char *buf,
                                size_t count)
 {
-        int n;
+       int n;
+       bool changed;
 
        if ((count > 0) && (1 == sscanf(buf, "%d", &n)) && (n >= 0)) {
+               changed = (scsi_debug_virtual_gb != n);
                scsi_debug_virtual_gb = n;
-
                sdebug_capacity = get_sdebug_capacity();
-
+               if (changed) {
+                       struct sdebug_host_info *sdhp;
+                       struct sdebug_dev_info *dp;
+
+                       list_for_each_entry(sdhp, &sdebug_host_list,
+                                           host_list) {
+                               list_for_each_entry(dp, &sdhp->dev_info_list,
+                                                   dev_list) {
+                                       set_bit(SDEBUG_UA_CAPACITY_CHANGED,
+                                               dp->uas_bm);
+                               }
+                       }
+               }
                return count;
        }
        return -EINVAL;