On Tue, May 29, 2018 at 08:53:06 -0400, John Ferlan wrote:
>
https://bugzilla.redhat.com/show_bug.cgi?id=1560946
>
> Similar to the the Logical backend, use qemu-img on the created
> disk partition device to set up for LUKS encryption. Secret mgmt
> for the device can be complicated by a reboot possibly changing
> the path to the device if the infrastructure changes.
>
> Signed-off-by: John Ferlan <jferlan(a)redhat.com>
> ---
> Changes in v2: Don't alter the result 'endOffset' of the
> DiskPartBoundaries, rather modify the input capacity value.
> Alteration of the value for the error path won't matter
> since the volume would be deleted anyway. The call to
> virStorageBackendDiskPartBoundaries was also slightly
> modified to check the return value vs -1 rather than != 0
> so that the call is similar to other calls. Separating
> that into it's own patch could have been done, but just
> felt like too much "busy work" to be worth the trouble.
>
> src/storage/storage_backend_disk.c | 49 ++++++++++++++++++++++----------------
> 1 file changed, 29 insertions(+), 20 deletions(-)
>
> diff --git a/src/storage/storage_backend_disk.c b/src/storage/storage_backend_disk.c
> index 2e3d1e04a4..e9578d01d6 100644
> --- a/src/storage/storage_backend_disk.c
> +++ b/src/storage/storage_backend_disk.c
> @@ -879,28 +879,26 @@ virStorageBackendDiskCreateVol(virStoragePoolObjPtr pool,
> char *partFormat = NULL;
> unsigned long long startOffset = 0, endOffset = 0;
> virStoragePoolDefPtr def = virStoragePoolObjGetDef(pool);
> + virErrorPtr save_err;
> virCommandPtr cmd = virCommandNewArgList(PARTED,
> def->source.devices[0].path,
> "mkpart",
> "--script",
> NULL);
>
> - if (vol->target.encryption != NULL) {
> - virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
> - "%s", _("storage pool does not support
encrypted "
> - "volumes"));
> - goto cleanup;
> - }
> -
> if (virStorageBackendDiskPartFormat(pool, vol, &partFormat) != 0)
> goto cleanup;
> virCommandAddArg(cmd, partFormat);
>
> - if (virStorageBackendDiskPartBoundaries(pool, &startOffset,
> - &endOffset,
> - vol->target.capacity) != 0) {
> + /* If we're going to encrypt using LUKS, then we could need up to
> + * an extra 2MB for the LUKS header - so account for that now */
> + if (vol->target.encryption &&
> + vol->target.encryption->format == VIR_STORAGE_ENCRYPTION_FORMAT_LUKS)
> + vol->target.capacity += 2 * 1024 * 1024;
So this is done only for LUKS encryption ...
> +
> + if (virStorageBackendDiskPartBoundaries(pool, &startOffset, &endOffset,
> + vol->target.capacity) < 0)
> goto cleanup;
> - }
>
> virCommandAddArgFormat(cmd, "%lluB", startOffset);
> virCommandAddArgFormat(cmd, "%lluB", endOffset);
> @@ -919,15 +917,15 @@ virStorageBackendDiskCreateVol(virStoragePoolObjPtr pool,
> VIR_FREE(vol->target.path);
>
> /* Fetch actual extent info, generate key */
> - if (virStorageBackendDiskReadPartitions(pool, vol) < 0) {
> - /* Best effort to remove the partition. Ignore any errors
> - * since we could be calling this with vol->target.path == NULL
> - */
> - virErrorPtr save_err = virSaveLastError();
> - ignore_value(virStorageBackendDiskDeleteVol(pool, vol, 0));
> - virSetError(save_err);
> - virFreeError(save_err);
> - goto cleanup;
> + if (virStorageBackendDiskReadPartitions(pool, vol) < 0)
> + goto error;
> +
> + if (vol->target.encryption) {
> + /* Adjust the sizes to account for the LUKS header */
> + vol->target.capacity -= 2 * 1024 * 1024;
> + vol->target.allocation -= 2 * 1024 * 1024;
but this is done for any encryption type, so if VIR_STORAGE_ENCRYPTION_FORMAT_QCOW
would be used it would rob off two megabytes of the volume size.
Honestly I think that VIR_STORAGE_ENCRYPTION_FORMAT_QCOW should be
disallowed for creation code right away, so that nobody creates the
broken format any more.
That way we don't have to deal with possibility that somebody with a old
qemu-img would run into problems here without adding much spurious code.
> + if (virStorageBackendCreateVolUsingQemuImg(pool, vol, NULL, 0) < 0)
> + goto error;
ACK if you reject VIR_STORAGE_ENCRYPTION_FORMAT_QCOW right at the
beginning.
OK... I'll add this to avoid QCOW and/or DEFAULT
if (vol->target.encryption &&
vol->target.encryption->format != VIR_STORAGE_ENCRYPTION_FORMAT_LUKS) {
virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
_("storage pool only supports LUKS encrypted volumes"));
Tks,
John
probably need a similar adjustment for the _logical backend too....