From: Matej Genci matej.genci@nutanix.com
mainline inclusion from mainline-5.10 commit beef6fd02b90 category: bugfix bugzilla: NA CVE: NA
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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@CY4PR02MB33... Suggested-by: Felipe Franciosi felipe@nutanix.com Acked-by: Paolo Bonzini pbonzini@redhat.com Signed-off-by: Matej Genci matej.genci@nutanix.com Signed-off-by: Martin K. Petersen martin.petersen@oracle.com Signed-off-by: Wenchao Hao haowenchao@huawei.com Reviewed-by: Jason Yan yanaijie@huawei.com Reviewed-by: Miaohe Lin linmiaohe@huawei.com Reviewed-by: Miaohe Lin linmiaohe@huawei.com Signed-off-by: Yang Yingliang yangyingliang@huawei.com --- 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 3d331a864b2fc..8118c06f491b9 100644 --- a/drivers/scsi/virtio_scsi.c +++ b/drivers/scsi/virtio_scsi.c @@ -323,7 +323,12 @@ 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);