scsi: fixup kernel warning during rmmod()

Calling rmmod() on a FC driver will results in warnings like

WARNING: CPU: 60 PID: 14640 at fs/sysfs/group.c:237 device_del+0x54/0x240()
sysfs group ffffffff81eff140 not found for kobject '3:0:0:3'

The problem here is that during scsi_remove_target() we will iterate
over all devices, but fail to remove any of those as the call to
scsi_device_get() fails the check to module_is_live().  Hence the
devices will not be removed at this point, but all intermediate
structures like fc rport etc. will be.  Later on during
scsi_forget_host() the devices are removed for real, but the device
parent is already removed and causes this warning.

Signed-off-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Kyle Fortin <kyle.fortin@oracle.com>
Tested-by: Don Brace <don.brace@microsemi.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c
index bf53356..f796bd6 100644 (file)
--- a/drivers/scsi/scsi_sysfs.c
+++ b/drivers/scsi/scsi_sysfs.c
@@ -1376,13 +1376,19 @@ static void __scsi_remove_target(struct scsi_target *starget)
        spin_lock_irqsave(shost->host_lock, flags);
  restart:
        list_for_each_entry(sdev, &shost->__devices, siblings) {
+               /*
+                * We cannot call scsi_device_get() here, as
+                * we might've been called from rmmod() causing
+                * scsi_device_get() to fail the module_is_live()
+                * check.
+                */
                if (sdev->channel != starget->channel ||
                    sdev->id != starget->id ||
-                   scsi_device_get(sdev))
+                   !get_device(&sdev->sdev_gendev))
                        continue;
                spin_unlock_irqrestore(shost->host_lock, flags);
                scsi_remove_device(sdev);
-               scsi_device_put(sdev);
+               put_device(&sdev->sdev_gendev);
                spin_lock_irqsave(shost->host_lock, flags);
                goto restart;
        }