librbd: attempt to restore deleted image from trash on known failures

If the image has watchers, snapshots, or group links, restore the image
from the trash back to the image directory since data removal hasn't yet
started.

Signed-off-by: Jason Dillaman <dillaman@redhat.com>

diff --git a/src/librbd/api/Image.cc b/src/librbd/api/Image.cc
index c77b6005aee615fb1a0fb1a0e78d510e0dbddad1..b657bc4fedf061849d7ed06822d0d3ea7f3c6640 100644 (file)
--- a/src/librbd/api/Image.cc
+++ b/src/librbd/api/Image.cc
@@ -750,6 +750,12 @@ int Image<I>::remove(IoCtx& io_ctx, const std::string &image_name,
       if (trash_image_source == RBD_TRASH_IMAGE_SOURCE_REMOVING) {
         // proceed with attempting to immediately remove the image
         r = Trash<I>::remove(io_ctx, image_id, true, prog_ctx);
+
+        if (r == -ENOTEMPTY || r == -EBUSY || r == -EMLINK) {
+          // best-effort try to restore the image if the removal
+          // failed for possible expected reasons
+          Trash<I>::restore(io_ctx, trash_image_source, image_id, image_name);
+        }
       }
       return r;
     } else if (r < 0 && r != -EOPNOTSUPP) {