[Qemu-devel] [PATCH 22/50] blockdev: Check BB validity in drive-backup TA

[Max Reitz]

In the drive-backup transaction, 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 | 15 ++++++++++-----
 1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/blockdev.c b/blockdev.c
index 012c603..5f7eef5 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -1507,23 +1507,28 @@ typedef struct DriveBackupState {
 static void drive_backup_prepare(BlkTransactionState *common, Error **errp)
 {
     DriveBackupState *state = DO_UPCAST(DriveBackupState, common, common);
-    BlockDriverState *bs;
+    BlockBackend *blk;
     DriveBackup *backup;
     Error *local_err = NULL;
 
     assert(common->action->kind == TRANSACTION_ACTION_KIND_DRIVE_BACKUP);
     backup = common->action->drive_backup;
 
-    bs = bdrv_find(backup->device);
-    if (!bs) {
+    blk = blk_by_name(backup->device);
+    if (!blk) {
         error_set(errp, QERR_DEVICE_NOT_FOUND, backup->device);
         return;
     }
 
     /* AioContext is released in .clean() */
-    state->aio_context = bdrv_get_aio_context(bs);
+    state->aio_context = blk_get_aio_context(blk);
     aio_context_acquire(state->aio_context);
 
+    if (!blk_is_available(blk)) {
+        error_set(errp, QERR_DEVICE_HAS_NO_MEDIUM, backup->device);
+        return;
+    }
+
     qmp_drive_backup(backup->device, backup->target,
                      backup->has_format, backup->format,
                      backup->sync,
@@ -1537,7 +1542,7 @@ static void drive_backup_prepare(BlkTransactionState 
*common, Error **errp)
         return;
     }
 
-    state->bs = bs;
+    state->bs = blk_bs(blk);
     state->job = state->bs->job;
 }
 
-- 
2.1.0