> Subject: [PATCH 3/3] scsi: storvsc: Correctly handle multiple flags in
> srb_status
>
> Hyper-V is observed to sometimes set multiple flags in the srb_status, such
> as ABORTED and ERROR. Current code in
> storvsc_handle_error() handles only a single flag being set, and does nothing
> when multiple flags are set. Fix this by changing the case statement into a
> series of "if" statements testing individual flags. The functionality for handling
> each flag is unchanged.
>
> Signed-off-by: Michael Kelley <mikelley@xxxxxxxxxxxxx>
> ---
> drivers/scsi/storvsc_drv.c | 61 +++++++++++++++++++++++++----------------
> -----
> 1 file changed, 33 insertions(+), 28 deletions(-)
>
> diff --git a/drivers/scsi/storvsc_drv.c b/drivers/scsi/storvsc_drv.c index
> fff9441..e96d2aa 100644
> --- a/drivers/scsi/storvsc_drv.c
> +++ b/drivers/scsi/storvsc_drv.c
> @@ -1009,17 +1009,40 @@ static void storvsc_handle_error(struct
> vmscsi_request *vm_srb,
> struct storvsc_scan_work *wrk;
> void (*process_err_fn)(struct work_struct *work);
> struct hv_host_device *host_dev = shost_priv(host);
> - bool do_work = false;
>
> - switch (SRB_STATUS(vm_srb->srb_status)) {
> - case SRB_STATUS_ERROR:
> + /*
> + * In some situations, Hyper-V sets multiple bits in the
> + * srb_status, such as ABORTED and ERROR. So process them
> + * individually, with the most specific bits first.
> + */
> +
> + if (vm_srb->srb_status & SRB_STATUS_INVALID_LUN) {
> + set_host_byte(scmnd, DID_NO_CONNECT);
> + process_err_fn = storvsc_remove_lun;
> + goto do_work;
> + }
> +
> + if (vm_srb->srb_status & SRB_STATUS_ABORTED) {
> + if (vm_srb->srb_status & SRB_STATUS_AUTOSENSE_VALID
> &&
> + /* Capacity data has changed */
> + (asc == 0x2a) && (ascq == 0x9)) {
> + process_err_fn = storvsc_device_scan;
> + /*
> + * Retry the I/O that triggered this.
> + */
> + set_host_byte(scmnd, DID_REQUEUE);
> + goto do_work;
> + }
> + }
> +
> + if (vm_srb->srb_status & SRB_STATUS_ERROR) {
I'm curious on SRB_STATUS_INVALID_LUN and SRB_STATUS_ABORTED, the actions on those two codes are different.
It doesn't look like we can get those two in the same status code.
> /*
> * Let upper layer deal with error when
> * sense message is present.
> */
> -
> if (vm_srb->srb_status & SRB_STATUS_AUTOSENSE_VALID)
> - break;
> + return;
> +
> /*
> * If there is an error; offline the device since all
> * error recovery strategies would have already been @@ -
> 1032,37 +1055,19 @@ static void storvsc_handle_error(struct vmscsi_request
> *vm_srb,
> set_host_byte(scmnd, DID_PASSTHROUGH);
> break;
> /*
> - * On Some Windows hosts TEST_UNIT_READY command can
> return
> - * SRB_STATUS_ERROR, let the upper level code deal with it
> - * based on the sense information.
> + * On some Hyper-V hosts TEST_UNIT_READY command can
> + * return SRB_STATUS_ERROR. Let the upper level code
> + * deal with it based on the sense information.
> */
> case TEST_UNIT_READY:
> break;
> default:
> set_host_byte(scmnd, DID_ERROR);
> }
> - break;
> - case SRB_STATUS_INVALID_LUN:
> - set_host_byte(scmnd, DID_NO_CONNECT);
> - do_work = true;
> - process_err_fn = storvsc_remove_lun;
> - break;
> - case SRB_STATUS_ABORTED:
> - if (vm_srb->srb_status & SRB_STATUS_AUTOSENSE_VALID
> &&
> - (asc == 0x2a) && (ascq == 0x9)) {
> - do_work = true;
> - process_err_fn = storvsc_device_scan;
> - /*
> - * Retry the I/O that triggered this.
> - */
> - set_host_byte(scmnd, DID_REQUEUE);
> - }
> - break;
> }
> + return;
>
> - if (!do_work)
> - return;
> -
> +do_work:
> /*
> * We need to schedule work to process this error; schedule it.
> */
> --
> 1.8.3.1
