[libvirt] [PATCH 1/4] rbd: Add wiping RBD volumes by using rbd_discard() or rbd_write()

John Ferlan jferlan at redhat.com
Fri Jan 22 00:57:04 UTC 2016



On 01/13/2016 08:52 AM, Wido den Hollander wrote:
> This allows user to use the volume wiping functionality of the libvirt
> storage driver.
> 
> This patch also adds a new wiping algorithm VIR_STORAGE_VOL_WIPE_ALG_DISCARD
> 
> By default the VIR_STORAGE_VOL_WIPE_ALG_ZERO algorithm is used and with
> RBD this will called rbd_write() in chunks of the underlying object size
> to completely zero out the volume.
> 
> With VIR_STORAGE_VOL_WIPE_ALG_DISCARD it will call rbd_discard() in the
> same object size chunks which will trim/discard all underlying RADOS objects
> in the Ceph cluster.
> 
> Signed-off-by: Wido den Hollander <wido at widodh.nl>
> ---
>  include/libvirt/libvirt-storage.h |   4 +
>  src/storage/storage_backend_rbd.c | 157 +++++++++++++++++++++++++++++++++++++-
>  tools/virsh-volume.c              |   2 +-
>  3 files changed, 161 insertions(+), 2 deletions(-)
> 

Looks like I missed these (I'm behind). Also, not sure why only 1 & 2 of
4 are here and there's cover letter.  I assume they are the same as the
two I reviewed today.

John
> diff --git a/include/libvirt/libvirt-storage.h b/include/libvirt/libvirt-storage.h
> index 2c55c93..139add3 100644
> --- a/include/libvirt/libvirt-storage.h
> +++ b/include/libvirt/libvirt-storage.h
> @@ -153,6 +153,10 @@ typedef enum {
>  
>      VIR_STORAGE_VOL_WIPE_ALG_RANDOM = 8, /* 1-pass random */
>  
> +    VIR_STORAGE_VOL_WIPE_ALG_DISCARD = 9, /* 1-pass, discard all data on the
> +                                                     volume by using TRIM or
> +                                                     DISCARD */
> +
>  # ifdef VIR_ENUM_SENTINELS
>      VIR_STORAGE_VOL_WIPE_ALG_LAST
>      /*
> diff --git a/src/storage/storage_backend_rbd.c b/src/storage/storage_backend_rbd.c
> index e20a54d..c0001d0 100644
> --- a/src/storage/storage_backend_rbd.c
> +++ b/src/storage/storage_backend_rbd.c
> @@ -32,6 +32,7 @@
>  #include "base64.h"
>  #include "viruuid.h"
>  #include "virstring.h"
> +#include "virutil.h"
>  #include "rados/librados.h"
>  #include "rbd/librbd.h"
>  
> @@ -730,6 +731,159 @@ static int virStorageBackendRBDResizeVol(virConnectPtr conn ATTRIBUTE_UNUSED,
>      return ret;
>  }
>  
> +static int virStorageBackendRBDVolWipeZero(rbd_image_t image,
> +                                           char *imgname,
> +                                           rbd_image_info_t info,
> +                                           uint64_t stripe_count)
> +{
> +    int r = -1;
> +    size_t offset = 0;
> +    uint64_t length;
> +    char *writebuf;
> +
> +    if (VIR_ALLOC_N(writebuf, info.obj_size * stripe_count) < 0)
> +        goto cleanup;
> +
> +    while (offset < info.size) {
> +        length = MIN((info.size - offset), (info.obj_size * stripe_count));
> +
> +        r = rbd_write(image, offset, length, writebuf);
> +        if (r < 0) {
> +            virReportSystemError(-r, _("writing %llu bytes failed on "
> +                                       " RBD image %s at offset %llu"),
> +                                     (unsigned long long)length,
> +                                     imgname,
> +                                     (unsigned long long)offset);
> +            goto cleanup;
> +        }
> +
> +        VIR_DEBUG("Wrote %llu bytes to RBD image %s at offset %llu",
> +                  (unsigned long long)length,
> +                  imgname, (unsigned long long)offset);
> +
> +        offset += length;
> +    }
> +
> + cleanup:
> +    VIR_FREE(writebuf);
> +
> +    return r;
> +}
> +
> +static int virStorageBackendRBDVolWipeDiscard(rbd_image_t image,
> +                                              char *imgname,
> +                                              rbd_image_info_t info,
> +                                              uint64_t stripe_count)
> +{
> +    int r = -1;
> +    size_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));
> +
> +        r = rbd_discard(image, offset, length);
> +        if (r < 0) {
> +            virReportSystemError(-r, _("discarding %llu bytes failed on "
> +                                       " RBD image %s at offset %llu"),
> +                                     (unsigned long long)length,
> +                                     imgname,
> +                                     (unsigned long long)offset);
> +            goto cleanup;
> +        }
> +
> +        VIR_DEBUG("Discarded %llu bytes of RBD image %s at offset %llu",
> +                  (unsigned long long)length,
> +                  imgname, (unsigned long long)offset);
> +
> +        offset += length;
> +    }
> +
> + cleanup:
> +    return r;
> +}
> +
> +static int virStorageBackendRBDVolWipe(virConnectPtr conn,
> +                                       virStoragePoolObjPtr pool,
> +                                       virStorageVolDefPtr vol,
> +                                       unsigned int algorithm,
> +                                       unsigned int flags)
> +{
> +    virStorageBackendRBDState ptr;
> +    ptr.cluster = NULL;
> +    ptr.ioctx = NULL;
> +    rbd_image_t image = NULL;
> +    rbd_image_info_t info;
> +    uint64_t stripe_count;
> +    int r = -1;
> +
> +    virCheckFlags(VIR_STORAGE_VOL_WIPE_ALG_ZERO |
> +                  VIR_STORAGE_VOL_WIPE_ALG_DISCARD, -1);
> +
> +    VIR_DEBUG("Wiping RBD image %s/%s", pool->def->source.name, vol->name);
> +
> +    if (virStorageBackendRBDOpenRADOSConn(&ptr, conn, &pool->def->source) < 0)
> +        goto cleanup;
> +
> +    if (virStorageBackendRBDOpenIoCTX(&ptr, pool) < 0)
> +        goto cleanup;
> +
> +    r = rbd_open(ptr.ioctx, vol->name, &image, NULL);
> +    if (r < 0) {
> +        virReportSystemError(-r, _("failed to open the RBD image %s"),
> +                             vol->name);
> +        goto cleanup;
> +    }
> +
> +    r = rbd_stat(image, &info, sizeof(info));
> +    if (r < 0) {
> +        virReportSystemError(-r, _("failed to stat the RBD image %s"),
> +                             vol->name);
> +        goto cleanup;
> +    }
> +
> +    r = rbd_get_stripe_count(image, &stripe_count);
> +    if (r < 0) {
> +        virReportSystemError(-r, _("failed to get stripe count of RBD image %s"),
> +                             vol->name);
> +        goto cleanup;
> +    }
> +
> +    VIR_DEBUG("Need to wipe %llu bytes from RBD image %s/%s",
> +              (unsigned long long)info.size, pool->def->source.name, vol->name);
> +
> +    switch (algorithm) {
> +        case VIR_STORAGE_VOL_WIPE_ALG_ZERO:
> +            r = virStorageBackendRBDVolWipeZero(image, vol->name,
> +                                                info, stripe_count);
> +            break;
> +        case VIR_STORAGE_VOL_WIPE_ALG_DISCARD:
> +            r = virStorageBackendRBDVolWipeDiscard(image, vol->name,
> +                                                   info, stripe_count);
> +            break;
> +        default:
> +            virReportError(VIR_ERR_INVALID_ARG, _("unsupported algorithm %d"),
> +                           algorithm);
> +            r = -VIR_ERR_INVALID_ARG;
> +            goto cleanup;
> +    }
> +
> +    if (r < 0) {
> +        virReportSystemError(-r, _("failed to wipe RBD image %s"),
> +                             vol->name);
> +        goto cleanup;
> +    }
> +
> + cleanup:
> +    if (image)
> +        rbd_close(image);
> +
> +    virStorageBackendRBDCloseRADOSConn(&ptr);
> +    return r;
> +}
> +
>  virStorageBackend virStorageBackendRBD = {
>      .type = VIR_STORAGE_POOL_RBD,
>  
> @@ -738,5 +892,6 @@ virStorageBackend virStorageBackendRBD = {
>      .buildVol = virStorageBackendRBDBuildVol,
>      .refreshVol = virStorageBackendRBDRefreshVol,
>      .deleteVol = virStorageBackendRBDDeleteVol,
> -    .resizeVol = virStorageBackendRBDResizeVol,
> +    .wipeVol = virStorageBackendRBDVolWipe,
> +    .resizeVol = virStorageBackendRBDResizeVol
>  };
> diff --git a/tools/virsh-volume.c b/tools/virsh-volume.c
> index 661c876..f86980f 100644
> --- a/tools/virsh-volume.c
> +++ b/tools/virsh-volume.c
> @@ -906,7 +906,7 @@ static const vshCmdOptDef opts_vol_wipe[] = {
>  VIR_ENUM_DECL(virStorageVolWipeAlgorithm)
>  VIR_ENUM_IMPL(virStorageVolWipeAlgorithm, VIR_STORAGE_VOL_WIPE_ALG_LAST,
>                "zero", "nnsa", "dod", "bsi", "gutmann", "schneier",
> -              "pfitzner7", "pfitzner33", "random");
> +              "pfitzner7", "pfitzner33", "random", "discard");
>  
>  static bool
>  cmdVolWipe(vshControl *ctl, const vshCmd *cmd)
> 




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