[libvirt] [PATCH] storage: Ignore block devices that fail format detection

[John Ferlan]

ping*2?

Tks -

John

On 10/30/2015 11:13 AM, John Ferlan wrote:
> https://bugzilla.redhat.com/show_bug.cgi?id=1276198
> 
> Prior to commit id '98322052' failure to saferead the block device would
> cause an error to be logged and the device to be skipped while attempting
> to discover/create a stable target path for a new LUN (NPIV).
> 
> This was because virStorageBackendSCSIFindLUs ignored errors from
> processLU and virStorageBackendSCSINewLun.
> 
> Ignoring the failure allowed a multipath device with an "active" and
> "ghost" to be present on the host with the "ghost" block device being
> ignored. This patch will return a -2 to the caller indicating the desire
> to ignore the block device since it cannot be used directly rather than
> fail the pool startup.
> 
> Additionally, it was found during some debugging that it was possible
> for the virStorageBackendDetectBlockVolFormatFD to not detect a format,
> which while not a probably - we probably should at least add some sort
> of warning message.
> 
> Signed-off-by: John Ferlan <jferlan at redhat.com>
> ---
>  src/storage/storage_backend.c      | 4 ++++
>  src/storage/storage_backend_scsi.c | 7 ++++++-
>  2 files changed, 10 insertions(+), 1 deletion(-)
> 
> diff --git a/src/storage/storage_backend.c b/src/storage/storage_backend.c
> index a375fe0..2de606f 100644
> --- a/src/storage/storage_backend.c
> +++ b/src/storage/storage_backend.c
> @@ -1393,6 +1393,10 @@ virStorageBackendDetectBlockVolFormatFD(virStorageSourcePtr target,
>          }
>      }
>  
> +    if (target->format == VIR_STORAGE_POOL_DISK_UNKNOWN)
> +        VIR_WARN("cannot determine the target format for '%s'",
> +                 target->path);
> +
>      return 0;
>  }
>  
> diff --git a/src/storage/storage_backend_scsi.c b/src/storage/storage_backend_scsi.c
> index a593a2b..d60473d 100644
> --- a/src/storage/storage_backend_scsi.c
> +++ b/src/storage/storage_backend_scsi.c
> @@ -224,9 +224,14 @@ virStorageBackendSCSINewLun(virStoragePoolObjPtr pool,
>          goto cleanup;
>      }
>  
> +    /* Failing to process the format is not fatal - we'll just skip
> +     * this volume.
> +     */
>      if (virStorageBackendUpdateVolInfo(vol, true,
> -                                       VIR_STORAGE_VOL_OPEN_DEFAULT) < 0)
> +                                       VIR_STORAGE_VOL_OPEN_DEFAULT) < 0) {
> +        retval = -2;
>          goto cleanup;
> +    }
>  
>      if (!(vol->key = virStorageBackendSCSISerial(vol->target.path)))
>          goto cleanup;
>