[libvirt] [PATCH 1/2] rbd: Implement wiping RBD volumes using rbd_discard()
This allows user to use the volume wiping functionality of the libvirt
storage driver.
All data from the volume will be wiped by calling rbd_discard() in chunks of the
underlying object and stripe size inside Ceph.
This will ensure all data is zeroed and leaves the user with a completely empty volume
ready for use again.
Signed-off-by: Wido den Hollander <wido(a)widodh.nl>
---
src/storage/storage_backend_rbd.c | 90 ++++++++++++++++++++++++++++++++++++++-
1 file changed, 89 insertions(+), 1 deletion(-)
diff --git a/src/storage/storage_backend_rbd.c b/src/storage/storage_backend_rbd.c
index cdbfdee..5e16e7a 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"
@@ -700,6 +701,92 @@ static int virStorageBackendRBDResizeVol(virConnectPtr conn
ATTRIBUTE_UNUSED,
return ret;
}
+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;
+ int r = -1;
+ size_t offset = 0;
+ uint64_t stripe_count;
+ uint64_t length;
+
+ virCheckFlags(0, -1);
+
+ VIR_DEBUG("Wiping RBD image %s/%s", pool->def->source.name,
vol->name);
+
+ if (algorithm != VIR_STORAGE_VOL_WIPE_ALG_ZERO) {
+ virReportError(VIR_ERR_NO_SUPPORT, "%s",
+ _("RBD storage pool does not support other wiping"
+ " algorithms than zero"));
+ goto cleanup;
+ }
+
+ 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);
+
+ 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,
+ vol->name,
+ (unsigned long long)offset);
+ goto cleanup;
+ }
+
+ VIR_DEBUG("Discarded %llu bytes of RBD image %s/%s at offset %llu",
+ (unsigned long long)length,
+ pool->def->source.name,
+ vol->name, (unsigned long long)offset);
+
+ offset += length;
+ }
+
+ cleanup:
+ if (image)
+ rbd_close(image);
+
+ virStorageBackendRBDCloseRADOSConn(&ptr);
+ return r;
+}
+
virStorageBackend virStorageBackendRBD = {
.type = VIR_STORAGE_POOL_RBD,
@@ -708,5 +795,6 @@ virStorageBackend virStorageBackendRBD = {
.buildVol = virStorageBackendRBDBuildVol,
.refreshVol = virStorageBackendRBDRefreshVol,
.deleteVol = virStorageBackendRBDDeleteVol,
- .resizeVol = virStorageBackendRBDResizeVol,
+ .wipeVol = virStorageBackendRBDVolWipe,
+ .resizeVol = virStorageBackendRBDResizeVol
};
--
1.9.1