From beef6fd02b906880c871ebdf6add166ebe54f632 Mon Sep 17 00:00:00 2001 From: Matej Genci Date: Fri, 28 Aug 2020 12:21:35 +0000 Subject: [PATCH] scsi: virtio_scsi: Rescan the entire target on transport reset when LUN is 0 VirtIO 1.0 spec says: The removed and rescan events ... when sent for LUN 0, they MAY apply to the entire target so the driver can ask the initiator to rescan the target to detect this. This change introduces the behaviour described above by scanning the entire SCSI target when LUN is set to 0. This is both a functional and a performance fix. It aligns the driver with the spec and allows control planes to hotplug targets with large numbers of LUNs without having to request a RESCAN for each one of them. Link: https://lore.kernel.org/r/CY4PR02MB33354370E0A81E75DD9DFE74FB520@CY4PR02MB3335.namprd02.prod.outlook.com Suggested-by: Felipe Franciosi Acked-by: Paolo Bonzini Signed-off-by: Matej Genci Signed-off-by: Martin K. Petersen --- drivers/scsi/virtio_scsi.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/scsi/virtio_scsi.c b/drivers/scsi/virtio_scsi.c index ca1c39b6f631..d454688dfd49 100644 --- a/drivers/scsi/virtio_scsi.c +++ b/drivers/scsi/virtio_scsi.c @@ -284,7 +284,12 @@ static void virtscsi_handle_transport_reset(struct virtio_scsi *vscsi, switch (virtio32_to_cpu(vscsi->vdev, event->reason)) { case VIRTIO_SCSI_EVT_RESET_RESCAN: - scsi_add_device(shost, 0, target, lun); + if (lun == 0) { + scsi_scan_target(&shost->shost_gendev, 0, target, + SCAN_WILD_CARD, SCSI_SCAN_INITIAL); + } else { + scsi_add_device(shost, 0, target, lun); + } break; case VIRTIO_SCSI_EVT_RESET_REMOVED: sdev = scsi_device_lookup(shost, 0, target, lun);