[SCSI] host state model update: mediate host add/remove race

Add support to not allow additions to a host when it is being removed.

Signed-off-by: Mike Anderson <andmike@us.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

1 files changed, 14 insertions, 7 deletions

diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c
index 2d3c4ac475f2..076cbe3b5a05 100644
--- a/drivers/scsi/scsi_scan.c
+++ b/drivers/scsi/scsi_scan.c
@@ -1251,9 +1251,12 @@ struct scsi_device *__scsi_add_device(struct Scsi_Host *shost, uint channel,
 
         get_device(&starget->dev);
         down(&shost->scan_mutex);
-        res = scsi_probe_and_add_lun(starget, lun, NULL, &sdev, 1, hostdata);
-        if (res != SCSI_SCAN_LUN_PRESENT)
-                sdev = ERR_PTR(-ENODEV);
+        if (scsi_host_scan_allowed(shost)) {
+                res = scsi_probe_and_add_lun(starget, lun, NULL, &sdev, 1,
+                                             hostdata);
+                if (res != SCSI_SCAN_LUN_PRESENT)
+                        sdev = ERR_PTR(-ENODEV);
+        }
         up(&shost->scan_mutex);
         scsi_target_reap(starget);
         put_device(&starget->dev);
@@ -1403,11 +1406,15 @@ int scsi_scan_host_selected(struct Scsi_Host *shost, unsigned int channel,
                 return -EINVAL;
 
         down(&shost->scan_mutex);
-        if (channel == SCAN_WILD_CARD) 
-                for (channel = 0; channel <= shost->max_channel; channel++)
+        if (scsi_host_scan_allowed(shost)) {
+                if (channel == SCAN_WILD_CARD)
+                        for (channel = 0; channel <= shost->max_channel;
+                             channel++)
+                                scsi_scan_channel(shost, channel, id, lun,
+                                                  rescan);
+                else
                         scsi_scan_channel(shost, channel, id, lun, rescan);
-        else
-                scsi_scan_channel(shost, channel, id, lun, rescan);
+        }
         up(&shost->scan_mutex);
 
         return 0;