Merge #6085: backport: merge bitcoin#21727, bitcoin#22371, bitcoin#21526

, bitcoin#23174, bitcoin#23785, bitcoin#23581, bitcoin#23974, bitcoin#22932, bitcoin#24050, bitcoin#24515 (blockstorage backports)

1bf0bf4 merge bitcoin#24515: Only load BlockMan in BlockMan member functions (Kittywhiskers Van Gogh)
5c1eb67 merge bitcoin#24050: Give m_block_index ownership of CBlockIndexes (Kittywhiskers Van Gogh)
c440304 merge bitcoin#22932: Add CBlockIndex lock annotations, guard nStatus/nFile/nDataPos/nUndoPos by cs_main (Kittywhiskers Van Gogh)
e303a4e merge bitcoin#23974: Make blockstorage globals private members of BlockManager (Kittywhiskers Van Gogh)
301163c merge bitcoin#23581: Move BlockManager to node/blockstorage (Kittywhiskers Van Gogh)
732e871 merge bitcoin#23785: Move stuff to ChainstateManager (Kittywhiskers Van Gogh)
b402fd5 merge bitcoin#23174: have LoadBlockIndex account for snapshot use (Kittywhiskers Van Gogh)
a08f2f4 merge bitcoin#21526: UpdateTip/CheckBlockIndex assumeutxo support (Kittywhiskers Van Gogh)
472caa0 merge bitcoin#22371: Move pblocktree global to BlockManager (Kittywhiskers Van Gogh)
d69ca83 merge bitcoin#21727: Move more stuff to blockstorage (Kittywhiskers Van Gogh)
6df927f chore: exclude underscore placeholder from shadowing linter warnings (Kittywhiskers Van Gogh)

Pull request description:

  ## Additional Information

  * Dependent on #6078

  * Dependent on #6074

  * Dependent on #6083

  * Dependent on #6119

  * Dependency for #6138

  * In [bitcoin#24050](bitcoin#24050), `BlockMap` is given ownership of the `CBlockIndex` instance contained within the `unordered_map`. The same has not been done for `PrevBlockMap` as `PrevBlockMap` is populated with `pprev` pointers and doing so seems to break validation logic.

  * Dash has a specific linter for all Dash-specific code present in Core. The introduction of `util/translation.h` into `validation.h` has caused the linter to trigger shadowing warnings due to a conflict between the common use of `_` as a placeholder/throwaway name ([source](https://github.com/dashpay/dash/blob/37e026a038a60313214e01b6aba029809ea7ad39/src/spork.cpp#L44)) and upstream's usage of it to process translatable strings ([source](https://github.com/dashpay/dash/blob/37e026a038a60313214e01b6aba029809ea7ad39/src/util/translation.h#L55-L62)).

    Neither C++17 nor C++20 have an _official_ placeholder/throwaway term or annotation for structured bindings (which cannot use `[[maybe_unused]` or `std::ignore`) but [P2169](https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2023/p2169r4.pdf) is a proposal put forth to make it the official placeholder, in that light, the linter will silence shadowing warnings involving an underscore.

  ## Breaking Changes

  None expected

  ## Checklist:

  - [x] I have performed a self-review of my own code
  - [x] I have commented my code, particularly in hard-to-understand areas **(note: N/A)**
  - [x] I have added or updated relevant unit/integration/functional/e2e tests
  - [x] I have made corresponding changes to the documentation **(note: N/A)**
  - [x] I have assigned this pull request to a milestone _(for repository code-owners and collaborators only)_

ACKs for top commit:
  UdjinM6:
    utACK 1bf0bf4 (with one nit)
  knst:
    utACK 1bf0bf4
  PastaPastaPasta:
    utACK 1bf0bf4

Tree-SHA512: 875fff34fe91916722f017526135697466e521d7179c473a5c0c444e3aa873369019b804dee9f5f795fc7ebed5c2481b5ce2d895b2950782a37de7b098157ad4

src/Makefile.test_util.include

@@ -9,6 +9,7 @@ EXTRA_LIBRARIES += \
 
 TEST_UTIL_H = \
     test/util/blockfilter.h \
+    test/util/chainstate.h \
     test/util/index.h \
     test/util/logging.h \
     test/util/mining.h \

src/chain.h

@@ -10,6 +10,7 @@
 #include <consensus/params.h>
 #include <flatfile.h>
 #include <primitives/block.h>
+#include <sync.h>
 #include <uint256.h>
 
 #include <vector>
@@ -34,6 +35,8 @@ static constexpr int64_t TIMESTAMP_WINDOW = MAX_FUTURE_BLOCK_TIME;
  */
 static constexpr int64_t MAX_BLOCK_TIME_GAP = 25 * 60;
 
+extern RecursiveMutex cs_main;
+
 class CBlockFileInfo
 {
 public:
@@ -124,6 +127,14 @@ enum BlockStatus: uint32_t {
     BLOCK_FAILED_MASK        =   BLOCK_FAILED_VALID | BLOCK_FAILED_CHILD,
 
     BLOCK_CONFLICT_CHAINLOCK =   128, //!< conflicts with chainlock system
+
+    /**
+     * If set, this indicates that the block index entry is assumed-valid.
+     * Certain diagnostics will be skipped in e.g. CheckBlockIndex().
+     * It almost certainly means that the block's full validation is pending
+     * on a background chainstate. See `doc/assumeutxo.md`.
+     */
+    BLOCK_ASSUMED_VALID      =   256,
 };
 
 /** The block chain is a tree shaped structure starting with the
@@ -147,13 +158,13 @@ class CBlockIndex
     int nHeight{0};
 
     //! Which # file this block is stored in (blk?????.dat)
-    int nFile{0};
+    int nFile GUARDED_BY(::cs_main){0};
 
     //! Byte offset within blk?????.dat where this block's data is stored
-    unsigned int nDataPos{0};
+    unsigned int nDataPos GUARDED_BY(::cs_main){0};
 
     //! Byte offset within rev?????.dat where this block's undo data is stored
-    unsigned int nUndoPos{0};
+    unsigned int nUndoPos GUARDED_BY(::cs_main){0};
 
     //! (memory only) Total amount of work (expected number of hashes) in the chain up to and including this block
     arith_uint256 nChainWork{};
@@ -181,7 +192,7 @@ class CBlockIndex
     //! load to avoid the block index being spuriously rewound.
     //! @sa NeedsRedownload
     //! @sa ActivateSnapshot
-    uint32_t nStatus{0};
+    uint32_t nStatus GUARDED_BY(::cs_main){0};
 
     //! block header
     int32_t nVersion{0};
@@ -209,7 +220,9 @@ class CBlockIndex
     {
     }
 
-    FlatFilePos GetBlockPos() const {
+    FlatFilePos GetBlockPos() const EXCLUSIVE_LOCKS_REQUIRED(::cs_main)
+    {
+        AssertLockHeld(::cs_main);
         FlatFilePos ret;
         if (nStatus & BLOCK_HAVE_DATA) {
             ret.nFile = nFile;
@@ -218,7 +231,9 @@ class CBlockIndex
         return ret;
     }
 
-    FlatFilePos GetUndoPos() const {
+    FlatFilePos GetUndoPos() const EXCLUSIVE_LOCKS_REQUIRED(::cs_main)
+    {
+        AssertLockHeld(::cs_main);
         FlatFilePos ret;
         if (nStatus & BLOCK_HAVE_UNDO) {
             ret.nFile = nFile;
@@ -284,21 +299,38 @@ class CBlockIndex
 
     //! Check whether this block index entry is valid up to the passed validity level.
     bool IsValid(enum BlockStatus nUpTo = BLOCK_VALID_TRANSACTIONS) const
+        EXCLUSIVE_LOCKS_REQUIRED(::cs_main)
     {
+        AssertLockHeld(::cs_main);
         assert(!(nUpTo & ~BLOCK_VALID_MASK)); // Only validity flags allowed.
         if (nStatus & BLOCK_FAILED_MASK)
             return false;
         return ((nStatus & BLOCK_VALID_MASK) >= nUpTo);
     }
 
+    //! @returns true if the block is assumed-valid; this means it is queued to be
+    //!   validated by a background chainstate.
+    bool IsAssumedValid() const EXCLUSIVE_LOCKS_REQUIRED(::cs_main)
+    {
+        AssertLockHeld(::cs_main);
+        return nStatus & BLOCK_ASSUMED_VALID;
+    }
+
     //! Raise the validity level of this block index entry.
     //! Returns true if the validity was changed.
-    bool RaiseValidity(enum BlockStatus nUpTo)
+    bool RaiseValidity(enum BlockStatus nUpTo) EXCLUSIVE_LOCKS_REQUIRED(::cs_main)
     {
+        AssertLockHeld(::cs_main);
         assert(!(nUpTo & ~BLOCK_VALID_MASK)); // Only validity flags allowed.
-        if (nStatus & BLOCK_FAILED_MASK)
-            return false;
+        if (nStatus & BLOCK_FAILED_MASK) return false;
+
         if ((nStatus & BLOCK_VALID_MASK) < nUpTo) {
+            // If this block had been marked assumed-valid and we're raising
+            // its validity to a certain point, there is no longer an assumption.
+            if (nStatus & BLOCK_ASSUMED_VALID && nUpTo >= BLOCK_VALID_SCRIPTS) {
+                nStatus &= ~BLOCK_ASSUMED_VALID;
+            }
+
             nStatus = (nStatus & ~BLOCK_VALID_MASK) | nUpTo;
             return true;
         }
@@ -339,6 +371,7 @@ class CDiskBlockIndex : public CBlockIndex
 
     SERIALIZE_METHODS(CDiskBlockIndex, obj)
     {
+        LOCK(::cs_main);
         int _nVersion = s.GetVersion();
         if (!(s.GetType() & SER_GETHASH)) READWRITE(VARINT_MODE(_nVersion, VarIntMode::NONNEGATIVE_SIGNED));
 

src/index/base.cpp

@@ -64,7 +64,7 @@ bool BaseIndex::Init()
     if (locator.IsNull()) {
         m_best_block_index = nullptr;
     } else {
-        m_best_block_index = m_chainstate->m_blockman.FindForkInGlobalIndex(active_chain, locator);
+        m_best_block_index = m_chainstate->FindForkInGlobalIndex(locator);
     }
 
     // Note: this will latch to true immediately if the user starts up with an empty

src/index/coinstatsindex.cpp

@@ -272,7 +272,7 @@ bool CoinStatsIndex::Rewind(const CBlockIndex* current_tip, const CBlockIndex* n
 
     {
         LOCK(cs_main);
-        CBlockIndex* iter_tip{m_chainstate->m_blockman.LookupBlockIndex(current_tip->GetBlockHash())};
+        const CBlockIndex* iter_tip{m_chainstate->m_blockman.LookupBlockIndex(current_tip->GetBlockHash())};
         const auto& consensus_params{Params().GetConsensus()};
 
         do {

src/index/txindex.cpp

@@ -4,6 +4,7 @@
 
 #include <index/disktxpos.h>
 #include <index/txindex.h>
+#include <node/blockstorage.h>
 #include <node/ui_interface.h>
 #include <shutdown.h>
 #include <util/system.h>
@@ -203,7 +204,7 @@ bool TxIndex::Init()
     // Attempt to migrate txindex from the old database to the new one. Even if
     // chain_tip is null, the node could be reindexing and we still want to
     // delete txindex records in the old database.
-    if (!m_db->MigrateData(*pblocktree, m_chainstate->m_chain.GetLocator())) {
+    if (!m_db->MigrateData(*m_chainstate->m_blockman.m_block_tree_db, m_chainstate->m_chain.GetLocator())) {
         return false;
     }
 
@@ -215,7 +216,9 @@ bool TxIndex::WriteBlock(const CBlock& block, const CBlockIndex* pindex)
     // Exclude genesis block transaction because outputs are not spendable.
     if (pindex->nHeight == 0) return true;
 
-    CDiskTxPos pos(pindex->GetBlockPos(), GetSizeOfCompactSize(block.vtx.size()));
+    CDiskTxPos pos{
+        WITH_LOCK(::cs_main, return pindex->GetBlockPos()),
+        GetSizeOfCompactSize(block.vtx.size())};
     std::vector<std::pair<uint256, CDiskTxPos>> vPos;
     vPos.reserve(block.vtx.size());
     for (const auto& tx : block.vtx) {

src/init.cpp

@@ -338,7 +338,6 @@ void PrepareShutdown(NodeContext& node)
                 chainstate->ResetCoinsViews();
             }
         }
-        pblocktree.reset();
         node.chain_helper.reset();
         if (node.mnhf_manager) {
             node.mnhf_manager->DisconnectManagers();
@@ -831,47 +830,6 @@ static void BlockNotifyGenesisWait(const CBlockIndex* pBlockIndex)
     }
 }
 
-// If we're using -prune with -reindex, then delete block files that will be ignored by the
-// reindex.  Since reindexing works by starting at block file 0 and looping until a blockfile
-// is missing, do the same here to delete any later block files after a gap.  Also delete all
-// rev files since they'll be rewritten by the reindex anyway.  This ensures that vinfoBlockFile
-// is in sync with what's actually on disk by the time we start downloading, so that pruning
-// works correctly.
-static void CleanupBlockRevFiles()
-{
-    std::map<std::string, fs::path> mapBlockFiles;
-
-    // Glob all blk?????.dat and rev?????.dat files from the blocks directory.
-    // Remove the rev files immediately and insert the blk file paths into an
-    // ordered map keyed by block file index.
-    LogPrintf("Removing unusable blk?????.dat and rev?????.dat files for -reindex with -prune\n");
-    fs::path blocksdir = gArgs.GetBlocksDirPath();
-    for (fs::directory_iterator it(blocksdir); it != fs::directory_iterator(); it++) {
-        if (fs::is_regular_file(*it) &&
-            it->path().filename().string().length() == 12 &&
-            it->path().filename().string().substr(8,4) == ".dat")
-        {
-            if (it->path().filename().string().substr(0,3) == "blk")
-                mapBlockFiles[it->path().filename().string().substr(3,5)] = it->path();
-            else if (it->path().filename().string().substr(0,3) == "rev")
-                remove(it->path());
-        }
-    }
-
-    // Remove all block files that aren't part of a contiguous set starting at
-    // zero by walking the ordered map (keys are block file indices) by
-    // keeping a separate counter.  Once we hit a gap (or if 0 doesn't exist)
-    // start removing block files.
-    int nContigCounter = 0;
-    for (const std::pair<const std::string, fs::path>& item : mapBlockFiles) {
-        if (LocaleIndependentAtoi<int>(item.first) == nContigCounter) {
-            nContigCounter++;
-            continue;
-        }
-        remove(item.second);
-    }
-}
-
 #if HAVE_SYSTEM
 static void StartupNotify(const ArgsManager& args)
 {
@@ -1992,6 +1950,7 @@ bool AppInitMain(NodeContext& node, interfaces::BlockAndHeaderTipInfo* tip_info)
 
                 UnloadBlockIndex(node.mempool.get(), chainman);
 
+                auto& pblocktree{chainman.m_blockman.m_block_tree_db};
                 // new CBlockTreeDB tries to delete the existing file, which
                 // fails if it's still open from the previous loop. Close it first:
                 pblocktree.reset();

src/llmq/instantsend.cpp

@@ -16,6 +16,7 @@
 #include <index/txindex.h>
 #include <masternode/sync.h>
 #include <net_processing.h>
+#include <node/blockstorage.h>
 #include <spork.h>
 #include <txmempool.h>
 #include <util/irange.h>

src/miner.cpp

@@ -57,7 +57,8 @@ int64_t UpdateTime(CBlockHeader* pblock, const Consensus::Params& consensusParam
     return nNewTime - nOldTime;
 }
 
-BlockAssembler::Options::Options() {
+BlockAssembler::Options::Options()
+{
     blockMinFeeRate = CFeeRate(DEFAULT_BLOCK_MIN_TX_FEE);
     nBlockMaxSize = DEFAULT_BLOCK_MAX_SIZE;
 }

src/net_processing.cpp

@@ -3926,7 +3926,7 @@ void PeerManagerImpl::ProcessMessage(
         LOCK(cs_main);
 
         // Find the last block the caller has in the main chain
-        const CBlockIndex* pindex = m_chainman.m_blockman.FindForkInGlobalIndex(m_chainman.ActiveChain(), locator);
+        const CBlockIndex* pindex = m_chainman.ActiveChainstate().FindForkInGlobalIndex(locator);
 
         // Send the rest of the chain
         if (pindex)
@@ -4046,7 +4046,7 @@ void PeerManagerImpl::ProcessMessage(
         else
         {
             // Find the last block the caller has in the main chain
-            pindex = m_chainman.m_blockman.FindForkInGlobalIndex(m_chainman.ActiveChain(), locator);
+            pindex = m_chainman.ActiveChainstate().FindForkInGlobalIndex(locator);
             if (pindex)
                 pindex = m_chainman.ActiveChain().Next(pindex);
         }