scripts: dbgbmap[d3].py: Moved rbyd/bptr checks behind --no-ckmeta/ckdata

Checking every data block for errors really slows down dbgbmap.py, which
is unfortunate for realtime rendering.

To be fair, the real issue is our naive crc32c impl, but the mindset of
these scripts is if you want speed you really shouldn't be using Python
and should rewrite the script in Rust/C/something (see prettyasserts for
example). You _could_ speed things up with a table-based crc32c, but at
that point you should probably just find C-bindings for crc32c (maybe
optional like inotify?... actually that's not a bad idea...).

At least --no-ckmeta/--no-ckdata allow for the previous behavior of not
checking for relevant errors for a bit of speed.

---

Note that --no-ckmeta currently doesn't really do anything. I toyed with
adding a non-fetching Rbyd.fetchtrunk method, but this seems out of
scope for these scripts.

scripts/dbgbmap.py

@@ -4249,6 +4249,8 @@ def main_(f, disk, mroots=None, *,
         block_size=None,
         block_count=None,
         blocks=None,
+        no_ckmeta=False,
+        no_ckdata=False,
         mtree_only=False,
         chars=[],
         colors=[],
@@ -4427,8 +4429,17 @@ def main_(f, disk, mroots=None, *,
                                 range(block_size))
                     corrupted = True
 
-                # corrupt block?
-                elif not child:
+                # corrupt metadata?
+                elif (not no_ckmeta
+                        and isinstance(child, (Mdir, Rbyd))
+                        and not child):
+                    bmap[b] = BmapBlock(b, 'corrupt', child, range(block_size))
+                    corrupted = True
+
+                # corrupt data?
+                elif (not no_ckdata
+                        and isinstance(child, Bptr)
+                        and not child):
                     bmap[b] = BmapBlock(b, 'corrupt', child, range(block_size))
                     corrupted = True
 
@@ -4778,6 +4789,14 @@ if __name__ == "__main__":
                     if ',' in x
                     else int(x, 0)),
             help="Show a specific block, may be a range.")
+    parser.add_argument(
+            '--no-ckmeta',
+            action='store_true',
+            help="Don't check metadata blocks for errors.")
+    parser.add_argument(
+            '--no-ckdata',
+            action='store_true',
+            help="Don't check metadata + data blocks for errors.")
     parser.add_argument(
             '--mtree-only',
             action='store_true',

scripts/dbgbmapd3.py

@@ -4578,6 +4578,8 @@ def main(disk, output, mroots=None, *,
         block_size=None,
         block_count=None,
         blocks=None,
+        no_ckmeta=False,
+        no_ckdata=False,
         mtree_only=False,
         quiet=False,
         labels=[],
@@ -4754,8 +4756,17 @@ def main(disk, output, mroots=None, *,
                                 range(block_size))
                     corrupted = True
 
-                # corrupt block?
-                elif not child:
+                # corrupt metadata?
+                elif (not no_ckmeta
+                        and isinstance(child, (Mdir, Rbyd))
+                        and not child):
+                    bmap[b] = BmapBlock(b, 'corrupt', child, range(block_size))
+                    corrupted = True
+
+                # corrupt data?
+                elif (not no_ckdata
+                        and isinstance(child, Bptr)
+                        and not child):
                     bmap[b] = BmapBlock(b, 'corrupt', child, range(block_size))
                     corrupted = True
 
@@ -5727,6 +5738,14 @@ if __name__ == "__main__":
                     if ',' in x
                     else int(x, 0)),
             help="Show a specific block, may be a range.")
+    parser.add_argument(
+            '--no-ckmeta',
+            action='store_true',
+            help="Don't check metadata blocks for errors.")
+    parser.add_argument(
+            '--no-ckdata',
+            action='store_true',
+            help="Don't check metadata + data blocks for errors.")
     parser.add_argument(
             '--mtree-only',
             action='store_true',