On 03/04/2017 01:50 AM, Stephen Hemminger wrote:
Needs more testing but this does fix the observed problem.

From: Stephen Hemminger <sthem...@microsoft.com>

Subject: [PATCH] hv_storvsc: fix error handling

The Hyper-V storvsc SCSI driver was hiding all errors in INQUIRY and
MODE_SENSE commands. This caused the scan process to incorrectly think
devices were present and online.  Also invalid LUN errors were not
being handled correctly.

This fixes problems booting a GEN2 VM on Hyper-V. It effectively
reverts commit 4ed51a21c0f69 ("Staging: hv: storvsc: Fixup
srb and scsi status for INQUIRY and MODE_SENSE")

Signed-off-by: Stephen Hemminger <sthem...@microsoft.com>
---
 drivers/scsi/storvsc_drv.c | 48 ++++------------------------------------------
 1 file changed, 4 insertions(+), 44 deletions(-)

diff --git a/drivers/scsi/storvsc_drv.c b/drivers/scsi/storvsc_drv.c
index 638e5f427c90..8cc241fc54b8 100644
--- a/drivers/scsi/storvsc_drv.c
+++ b/drivers/scsi/storvsc_drv.c
@@ -543,28 +543,6 @@ static void storvsc_host_scan(struct work_struct *work)
        kfree(wrk);
 }

-static void storvsc_remove_lun(struct work_struct *work)
-{
-       struct storvsc_scan_work *wrk;
-       struct scsi_device *sdev;
-
-       wrk = container_of(work, struct storvsc_scan_work, work);
-       if (!scsi_host_get(wrk->host))
-               goto done;
-
-       sdev = scsi_device_lookup(wrk->host, 0, wrk->tgt_id, wrk->lun);
-
-       if (sdev) {
-               scsi_remove_device(sdev);
-               scsi_device_put(sdev);
-       }
-       scsi_host_put(wrk->host);
-
-done:
-       kfree(wrk);
-}
-
-
 /*
  * We can get incoming messages from the host that are not in response to
  * messages that we have sent out. An example of this would be messages
@@ -955,8 +933,7 @@ static void storvsc_handle_error(struct vmscsi_request 
*vm_srb,
                }
                break;
        case SRB_STATUS_INVALID_LUN:
-               do_work = true;
-               process_err_fn = storvsc_remove_lun;
+               set_host_byte(scmnd, DID_NO_CONNECT);
                break;
        case SRB_STATUS_ABORTED:
                if (vm_srb->srb_status & SRB_STATUS_AUTOSENSE_VALID &&
@@ -1050,32 +1027,15 @@ static void storvsc_on_io_completion(struct 
storvsc_device *stor_device,

        stor_pkt = &request->vstor_packet;

-       /*
-        * The current SCSI handling on the host side does
-        * not correctly handle:
-        * INQUIRY command with page code parameter set to 0x80
-        * MODE_SENSE command with cmd[2] == 0x1c
-        *
-        * Setup srb and scsi status so this won't be fatal.
-        * We do this so we can distinguish truly fatal failues
-        * (srb status == 0x4) and off-line the device in that case.
-        */
-
-       if ((stor_pkt->vm_srb.cdb[0] == INQUIRY) ||
-          (stor_pkt->vm_srb.cdb[0] == MODE_SENSE)) {
-               vstor_packet->vm_srb.scsi_status = 0;
-               vstor_packet->vm_srb.srb_status = SRB_STATUS_SUCCESS;
-       }
-
-
        /* Copy over the status...etc */
        stor_pkt->vm_srb.scsi_status = vstor_packet->vm_srb.scsi_status;
        stor_pkt->vm_srb.srb_status = vstor_packet->vm_srb.srb_status;
        stor_pkt->vm_srb.sense_info_length =
        vstor_packet->vm_srb.sense_info_length;

-       if (vstor_packet->vm_srb.scsi_status != 0 ||
-           vstor_packet->vm_srb.srb_status != SRB_STATUS_SUCCESS)
+       if (stor_pkt->vm_srb.cdb[0] != INQUIRY &&
+           (vstor_packet->vm_srb.scsi_status != 0 ||
+            vstor_packet->vm_srb.srb_status != SRB_STATUS_SUCCESS))
                storvsc_log(device, STORVSC_LOGGING_WARN,
                        "cmd 0x%x scsi status 0x%x srb status 0x%x\n",
                        stor_pkt->vm_srb.cdb[0],

I really do wonder; according to the comments above the wrong error handling really only affects inquiry VPD page 0x80 and MODE_SENSE page 0x1c. So why do we need to blank out _every_ inquiry? Wouldn't it far better to check _what_ goes wrong when asking for page 0x80, and fix up things correctly?

Cheers,

Hannes
--
Dr. Hannes Reinecke                   zSeries & Storage
h...@suse.de                          +49 911 74053 688
SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg
GF: J. Hawn, J. Guild, F. Imendörffer, HRB 16746 (AG Nürnberg)

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