blockdev-backup: added support for data compression

The idea is simple - backup is "written-once" data. It is written block
by block and it is large enough. It would be nice to save storage
space and compress it.

Signed-off-by: Pavel Butsykin <pbutsykin@virtuozzo.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>
CC: Jeff Cody <jcody@redhat.com>
CC: Markus Armbruster <armbru@redhat.com>
CC: Eric Blake <eblake@redhat.com>
CC: John Snow <jsnow@redhat.com>
CC: Stefan Hajnoczi <stefanha@redhat.com>
CC: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

1 files changed, 5 insertions, 2 deletions

diff --git a/blockdev.c b/blockdev.c
index f5857d0..97062e3 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -3254,6 +3254,9 @@ void do_blockdev_backup(BlockdevBackup *backup, BlockJobTxn *txn, Error **errp)
     if (!backup->has_job_id) {
         backup->job_id = NULL;
     }
+    if (!backup->has_compress) {
+        backup->compress = false;
+    }
 
     bs = qmp_get_root_bs(backup->device, errp);
     if (!bs) {
@@ -3280,8 +3283,8 @@ void do_blockdev_backup(BlockdevBackup *backup, BlockJobTxn *txn, Error **errp)
         }
     }
     backup_start(backup->job_id, bs, target_bs, backup->speed, backup->sync,
-                 NULL, false, backup->on_source_error, backup->on_target_error,
-                 block_job_cb, bs, txn, &local_err);
+                 NULL, backup->compress, backup->on_source_error,
+                 backup->on_target_error, block_job_cb, bs, txn, &local_err);
     if (local_err != NULL) {
         error_propagate(errp, local_err);
     }