Call blk_is_available() before using blk_bs() to obtain the root BlockDriverState behind the BlockBackend.
Signed-off-by: Max Reitz <mre...@redhat.com> --- blockdev.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) diff --git a/blockdev.c b/blockdev.c index 9476c72..e335d06 100644 --- a/blockdev.c +++ b/blockdev.c @@ -2452,6 +2452,7 @@ void qmp_blockdev_backup(const char *device, const char *target, BlockdevOnError on_target_error, Error **errp) { + BlockBackend *blk; BlockDriverState *bs; BlockDriverState *target_bs; Error *local_err = NULL; @@ -2467,15 +2468,21 @@ void qmp_blockdev_backup(const char *device, const char *target, on_target_error = BLOCKDEV_ON_ERROR_REPORT; } - bs = bdrv_find(device); - if (!bs) { + blk = blk_by_name(device); + if (!blk) { error_set(errp, QERR_DEVICE_NOT_FOUND, device); return; } - aio_context = bdrv_get_aio_context(bs); + aio_context = blk_get_aio_context(blk); aio_context_acquire(aio_context); + if (!blk_is_available(blk)) { + error_set(errp, QERR_DEVICE_HAS_NO_MEDIUM, device); + goto out; + } + bs = blk_bs(blk); + target_bs = bdrv_find(target); if (!target_bs) { error_set(errp, QERR_DEVICE_NOT_FOUND, target); -- 2.1.0