Merge bitcoin/bitcoin#24789: init, index: disallow indexes when running reindex-chainstate

dac44fc init: disallow reindex-chainstate with optional indexes (Martin Zumsande)
62e1428 doc: Add note that -reindex will rebuild optional indexes (Martin Zumsande)

Pull request description:

  When started together with `-reindex-chainstate`, currently coinstatsindex gets corrupted and the blockfilterindex flatfiles duplicated. See the OP of #24630 for more a more detailed explanation on why this happens.

  This is an alternative to #24630 which does not wipe and rebuild the indexes but returns an `InitError` when they are activated, thus requiring the user to deactivate them temporarily until the `-reindex-chainstate` run is finished.

  This also disallows `-reindex-chainstate` in combination with `-txindex`, which is not leading to corruption, but currently still rebuilds the index unnecessarily and unexpectedly.

  As a long-term goal, it would be desirable to have the indexes tolerate `reindex-chainstate` by ignoring their `BlockConnected` notifications (there is discussion in #24630 about this) or possibly move `reindex-chainstate` option  into a `bitcoin-chainstate` executable, which could also solve the problem. But these would be larger projects - until then, it might be better to disallow the interaction than having corrupted indexes.

  The first commit adjusts the `-reindex` doc to mention that this option does rebuild all active indexes.

ACKs for top commit:
  ryanofsky:
    Code review ACK dac44fc. Just fixed IsArgSet call and edited error messages since last review

Tree-SHA512: c1abf7d350648ae227c3fd6c95d9a54c3bac9de70915275dea1c87cca6d9a76a056c0e306d95ef8cfe4df1f8525b418e0e7a4f52ded3be464041c0dc297f8930

Author: fanquake

src/init.cpp

@@ -424,8 +424,8 @@ void SetupServerArgs(ArgsManager& argsman)
     argsman.AddArg("-prune=<n>", strprintf("Reduce storage requirements by enabling pruning (deleting) of old blocks. This allows the pruneblockchain RPC to be called to delete specific blocks, and enables automatic pruning of old blocks if a target size in MiB is provided. This mode is incompatible with -txindex and -coinstatsindex. "
             "Warning: Reverting this setting requires re-downloading the entire blockchain. "
             "(default: 0 = disable pruning blocks, 1 = allow manual pruning via RPC, >=%u = automatically prune block files to stay under the specified target size in MiB)", MIN_DISK_SPACE_FOR_BLOCK_FILES / 1024 / 1024), ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);
-    argsman.AddArg("-reindex", "Rebuild chain state and block index from the blk*.dat files on disk", ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);
-    argsman.AddArg("-reindex-chainstate", "Rebuild chain state from the currently indexed blocks. When in pruning mode or if blocks on disk might be corrupted, use full -reindex instead.", ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);
+    argsman.AddArg("-reindex", "Rebuild chain state and block index from the blk*.dat files on disk. This will also rebuild active optional indexes.", ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);
+    argsman.AddArg("-reindex-chainstate", "Rebuild chain state from the currently indexed blocks. When in pruning mode or if blocks on disk might be corrupted, use full -reindex instead. Deactivate all optional indexes before running this.", ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);
     argsman.AddArg("-settings=<file>", strprintf("Specify path to dynamic settings data file. Can be disabled with -nosettings. File is written at runtime and not meant to be edited by users (use %s instead for custom settings). Relative paths will be prefixed by datadir location. (default: %s)", BITCOIN_CONF_FILENAME, BITCOIN_SETTINGS_FILENAME), ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);
 #if HAVE_SYSTEM
     argsman.AddArg("-startupnotify=<cmd>", "Execute command on startup.", ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);
@@ -1033,6 +1033,19 @@ bool AppInitParameterInteraction(const ArgsManager& args, bool use_syscall_sandb
         return InitError(_("No proxy server specified. Use -proxy=<ip> or -proxy=<ip:port>."));
     }
 
+    if (args.GetBoolArg("-reindex-chainstate", false)) {
+        // indexes that must be deactivated to prevent index corruption, see #24630
+        if (args.GetBoolArg("-coinstatsindex", DEFAULT_COINSTATSINDEX)) {
+            return InitError(_("-reindex-chainstate option is not compatible with -coinstatsindex. Please temporarily disable coinstatsindex while using -reindex-chainstate, or replace -reindex-chainstate with -reindex to fully rebuild all indexes."));
+        }
+        if (g_enabled_filter_types.count(BlockFilterType::BASIC)) {
+            return InitError(_("-reindex-chainstate option is not compatible with -blockfilterindex. Please temporarily disable blockfilterindex while using -reindex-chainstate, or replace -reindex-chainstate with -reindex to fully rebuild all indexes."));
+        }
+        if (args.GetBoolArg("-txindex", DEFAULT_TXINDEX)) {
+            return InitError(_("-reindex-chainstate option is not compatible with -txindex. Please temporarily disable txindex while using -reindex-chainstate, or replace -reindex-chainstate with -reindex to fully rebuild all indexes."));
+        }
+    }
+
 #if defined(USE_SYSCALL_SANDBOX)
     if (args.IsArgSet("-sandbox") && !args.IsArgNegated("-sandbox")) {
         const std::string sandbox_arg{args.GetArg("-sandbox", "")};

test/functional/feature_coinstatsindex.py

@@ -223,6 +223,20 @@ def _test_coin_stats_index(self):
         res10 = index_node.gettxoutsetinfo('muhash')
         assert(res8['txouts'] < res10['txouts'])
 
+        self.log.info("Test that the index works with -reindex")
+
+        self.restart_node(1, extra_args=["-coinstatsindex", "-reindex"])
+        res11 = index_node.gettxoutsetinfo('muhash')
+        assert_equal(res11, res10)
+
+        self.log.info("Test that -reindex-chainstate is disallowed with coinstatsindex")
+
+        self.nodes[1].assert_start_raises_init_error(
+            expected_msg='Error: -reindex-chainstate option is not compatible with -coinstatsindex. '
+            'Please temporarily disable coinstatsindex while using -reindex-chainstate, or replace -reindex-chainstate with -reindex to fully rebuild all indexes.',
+            extra_args=['-coinstatsindex', '-reindex-chainstate'],
+        )
+
     def _test_use_index_option(self):
         self.log.info("Test use_index option for nodes running the index")
 

test/functional/p2p_blockfilters.py

@@ -250,6 +250,12 @@ def run_test(self):
         msg = "Error: Cannot set -peerblockfilters without -blockfilterindex."
         self.nodes[0].assert_start_raises_init_error(expected_msg=msg)
 
+        self.log.info("Test -blockfilterindex with -reindex-chainstate raises an error")
+        self.nodes[0].assert_start_raises_init_error(
+            expected_msg='Error: -reindex-chainstate option is not compatible with -blockfilterindex. '
+            'Please temporarily disable blockfilterindex while using -reindex-chainstate, or replace -reindex-chainstate with -reindex to fully rebuild all indexes.',
+            extra_args=['-blockfilterindex', '-reindex-chainstate'],
+        )
 
 def compute_last_header(prev_header, hashes):
     """Compute the last filter header from a starting header and a sequence of filter hashes."""