From 5ff843721467b4ef8d857b4724e3da7f515cf242 Mon Sep 17 00:00:00 2001 From: Matt Lupfer Date: Thu, 5 Sep 2019 18:19:28 +0000 Subject: [PATCH] scsi: virtio_scsi: unplug LUNs when events missed The event handler calls scsi_scan_host() when events are missed, which will hotplug new LUNs. However, this function won't remove any unplugged LUNs. The result is that hotunplug doesn't work properly when the number of unplugged LUNs exceeds the event queue size (currently 8). Scan existing LUNs when events are missed to check if they are still present. If not, remove them. Link: https://lore.kernel.org/r/20190905181903.29756-1-mlupfer@ddn.com Signed-off-by: Matt Lupfer Reviewed-by: Stefan Hajnoczi Acked-by: Paolo Bonzini Signed-off-by: Martin K. Petersen --- drivers/scsi/virtio_scsi.c | 33 +++++++++++++++++++++++++++++++++ 1 file changed, 33 insertions(+) diff --git a/drivers/scsi/virtio_scsi.c b/drivers/scsi/virtio_scsi.c index cff083049d5c..bfec84aacd90 100644 --- a/drivers/scsi/virtio_scsi.c +++ b/drivers/scsi/virtio_scsi.c @@ -30,6 +30,8 @@ #include #include +#include "sd.h" + #define VIRTIO_SCSI_MEMPOOL_SZ 64 #define VIRTIO_SCSI_EVENT_LEN 8 #define VIRTIO_SCSI_VQ_BASE 2 @@ -324,6 +326,36 @@ static void virtscsi_handle_param_change(struct virtio_scsi *vscsi, scsi_device_put(sdev); } +static void virtscsi_rescan_hotunplug(struct virtio_scsi *vscsi) +{ + struct scsi_device *sdev; + struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev); + unsigned char scsi_cmd[MAX_COMMAND_SIZE]; + int result, inquiry_len, inq_result_len = 256; + char *inq_result = kmalloc(inq_result_len, GFP_KERNEL); + + shost_for_each_device(sdev, shost) { + inquiry_len = sdev->inquiry_len ? sdev->inquiry_len : 36; + + memset(scsi_cmd, 0, sizeof(scsi_cmd)); + scsi_cmd[0] = INQUIRY; + scsi_cmd[4] = (unsigned char) inquiry_len; + + memset(inq_result, 0, inq_result_len); + + result = scsi_execute_req(sdev, scsi_cmd, DMA_FROM_DEVICE, + inq_result, inquiry_len, NULL, + SD_TIMEOUT, SD_MAX_RETRIES, NULL); + + if (result == 0 && inq_result[0] >> 5) { + /* PQ indicates the LUN is not attached */ + scsi_remove_device(sdev); + } + } + + kfree(inq_result); +} + static void virtscsi_handle_event(struct work_struct *work) { struct virtio_scsi_event_node *event_node = @@ -335,6 +367,7 @@ static void virtscsi_handle_event(struct work_struct *work) cpu_to_virtio32(vscsi->vdev, VIRTIO_SCSI_T_EVENTS_MISSED)) { event->event &= ~cpu_to_virtio32(vscsi->vdev, VIRTIO_SCSI_T_EVENTS_MISSED); + virtscsi_rescan_hotunplug(vscsi); scsi_scan_host(virtio_scsi_host(vscsi->vdev)); }