On 01/27/2016 05:20 AM, Wido den Hollander wrote:
> Using VIR_STORAGE_VOL_WIPE_ALG_TRIM a RBD volume can be trimmed down
> to 0 bytes using rbd_dicard()
s/dicard/discard
>
> Effectively all the data on the volume will be lost/gone, but the volume
> remains available for use afterwards.
>
> Starting at offset 0 the storage pool will call rbd_discard() in stripe
> size * count increments which is usually 4MB. Stripe size being 4MB and
> count 1.
>
> rbd_discard() is available since Ceph version Dumpling (0.67) which dates
> back to August 2013.
>
> Signed-off-by: Wido den Hollander <wido@xxxxxxxxx>
> ---
> src/storage/storage_backend_rbd.c | 42 ++++++++++++++++++++++++++++++++++++++-
> 1 file changed, 41 insertions(+), 1 deletion(-)
>
> diff --git a/src/storage/storage_backend_rbd.c b/src/storage/storage_backend_rbd.c
> index 7e669ff..8a95388 100644
> --- a/src/storage/storage_backend_rbd.c
> +++ b/src/storage/storage_backend_rbd.c
> @@ -772,6 +772,41 @@ virStorageBackendRBDVolWipeZero(rbd_image_t image,
> }
>
> static int
> +virStorageBackendRBDVolWipeDiscard(rbd_image_t image,
> + char *imgname,
> + rbd_image_info_t info,
Like WipeZero, I adjusted to be *info to silence coverity. Other
adjustments for info-> and &info were similarly made and pushed.
Tks -
John
> + uint64_t stripe_count)
> +{
> + int r = -1;
> + int ret = -1;
> + uint64_t offset = 0;
> + uint64_t length;
> +
> + VIR_DEBUG("Wiping RBD %s volume using discard)", imgname);
> +
> + while (offset < info.size) {
> + length = MIN((info.size - offset), (info.obj_size * stripe_count));
> +
> + if ((r = rbd_discard(image, offset, length)) < 0) {
> + virReportSystemError(-r, _("discarding %zu bytes failed on "
> + "RBD image %s at offset %zu"),
> + length, imgname, offset);
> + goto cleanup;
> + }
> +
> + VIR_DEBUG("Discarded %zu bytes of RBD image %s at offset %zu",
> + length, imgname, offset);
> +
> + offset += length;
> + }
> +
> + ret = 0;
> +
> + cleanup:
> + return ret;
> +}
> +
> +static int
> virStorageBackendRBDVolWipe(virConnectPtr conn,
> virStoragePoolObjPtr pool,
> virStorageVolDefPtr vol,
> @@ -787,7 +822,8 @@ virStorageBackendRBDVolWipe(virConnectPtr conn,
> int r = -1;
> int ret = -1;
>
> - virCheckFlags(VIR_STORAGE_VOL_WIPE_ALG_ZERO, -1);
> + virCheckFlags(VIR_STORAGE_VOL_WIPE_ALG_ZERO |
> + VIR_STORAGE_VOL_WIPE_ALG_TRIM, -1);
>
> VIR_DEBUG("Wiping RBD image %s/%s", pool->def->source.name, vol->name);
>
> @@ -823,6 +859,10 @@ virStorageBackendRBDVolWipe(virConnectPtr conn,
> r = virStorageBackendRBDVolWipeZero(image, vol->name,
> info, stripe_count);
> break;
> + case VIR_STORAGE_VOL_WIPE_ALG_TRIM:
> + r = virStorageBackendRBDVolWipeDiscard(image, vol->name,
> + info, stripe_count);
> + break;
> default:
> virReportError(VIR_ERR_INVALID_ARG, _("unsupported algorithm %d"),
> algorithm);
>
--
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