Re: [Qemu-devel] [PATCH v3 2/3] scsi: Enhance scsi_sense_to_errno

[Paolo Bonzini <pbonzini@redhat.com>]

On 18/08/2017 16:15, Fam Zheng wrote:
> Two changes:
> 
> 1) Look at asc/ascq for NOT_READY and DATA_PROTECT;
> 2) Translate SPACE_ALLOC_FAILED as ENOSPC;
> 
> Signed-off-by: Fam Zheng <famz@redhat.com>
> ---
>  util/scsi.c | 7 +++----
>  1 file changed, 3 insertions(+), 4 deletions(-)
> 
> diff --git a/util/scsi.c b/util/scsi.c
> index 92ca436cd0..d42ce33449 100644
> --- a/util/scsi.c
> +++ b/util/scsi.c
> @@ -18,13 +18,11 @@
>  int scsi_sense_to_errno(int key, int asc, int ascq)
>  {
>      switch (key) {
> -    case 0x02: /* SCSI_SENSE_NOT_READY */
> -        return EBUSY;
> -    case 0x07: /* SCSI_SENSE_DATA_PROTECTION */
> -        return EACCES;
>      case 0x0b: /* SCSI_SENSE_COMMAND_ABORTED */
>          return ECANCELED;
> +    case 0x02: /* SCSI_SENSE_NOT_READY */
>      case 0x05: /* SCSI_SENSE_ILLEGAL_REQUEST */
> +    case 0x07: /* SCSI_SENSE_DATA_PROTECTION */
>          /* Parse ASCQ */
>          break;
>      default:

UNIT_ATTENTION should also be passed down to the guest without stopping
the VM.  Maybe map it to EAGAIN?

Looking at what Linux does:

- RECOVERED_ERROR should just return 0

- 0x0401 is "unit in the process of becoming ready", and it should also
be EAGAIN

- 0x0402 is "initializing command required", and probably can be fixed
by the guest by scsi-block but not by iscsi so it should be its own
errno, maybe ENOTCONN?  (iscsi might try sending START STOP UNIT
followed by a bunch of TEST UNIT READYs, see scsi_eh_try_stu in Linux's
drivers/scsi/scsi_error.c).

Paolo

> @@ -37,6 +35,7 @@ int scsi_sense_to_errno(int key, int asc, int ascq)
>      case 0x2600: /* SCSI_SENSE_ASCQ_INVALID_FIELD_IN_PARAMETER_LIST */
>          return EINVAL;
>      case 0x2100: /* SCSI_SENSE_ASCQ_LBA_OUT_OF_RANGE */
> +    case 0x2707: /* SCSI_SENSE_ASCQ_SPACE_ALLOC_FAILED */
>          return ENOSPC;
>      case 0x2500: /* SCSI_SENSE_ASCQ_LOGICAL_UNIT_NOT_SUPPORTED */
>          return ENOTSUP;
>