block: fix external snapshot abort permission error
In external_snapshot_abort(), we try to undo what was done in external_snapshot_prepare() calling bdrv_replace_node() to swap the nodes back. However, we receive a permissions error as writers are blocked on the old node, which is now the new node backing file. An easy fix (initially suggested by Kevin Wolf) is to call bdrv_set_backing_hd() on the new node, to set the backing node to NULL. Signed-off-by: Jeff Cody <jcody@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
		
							parent
							
								
									272545cf21
								
							
						
					
					
						commit
						719fc28c80
					
				| 
						 | 
				
			
			@ -1803,7 +1803,11 @@ static void external_snapshot_abort(BlkActionState *common)
 | 
			
		|||
                             DO_UPCAST(ExternalSnapshotState, common, common);
 | 
			
		||||
    if (state->new_bs) {
 | 
			
		||||
        if (state->overlay_appended) {
 | 
			
		||||
            bdrv_ref(state->old_bs);   /* we can't let bdrv_set_backind_hd()
 | 
			
		||||
                                          close state->old_bs; we need it */
 | 
			
		||||
            bdrv_set_backing_hd(state->new_bs, NULL, &error_abort);
 | 
			
		||||
            bdrv_replace_node(state->new_bs, state->old_bs, &error_abort);
 | 
			
		||||
            bdrv_unref(state->old_bs); /* bdrv_replace_node() ref'ed old_bs */
 | 
			
		||||
        }
 | 
			
		||||
    }
 | 
			
		||||
}
 | 
			
		||||
| 
						 | 
				
			
			
 | 
			
		|||
		Loading…
	
		Reference in New Issue