diff --git a/src/test/util/chainstate.h b/src/test/util/chainstate.h
--- a/src/test/util/chainstate.h
+++ b/src/test/util/chainstate.h
@@ -121,8 +121,24 @@
return node.chainman->ActiveHeight()));
}
- return node.chainman->ActivateSnapshot(auto_infile, metadata,
- in_memory_chainstate);
+ auto &new_active = node.chainman->ActiveChainstate();
+ auto *tip = new_active.m_chain.Tip();
+
+ // Disconnect a block so that the snapshot chainstate will be ahead,
+ // otherwise it will refuse to activate.
+ //
+ // TODO this is a unittest-specific hack, and we should probably rethink how
+ // to better generate/activate snapshots in unittests.
+ if (tip->pprev) {
+ new_active.m_chain.SetTip(*(tip->pprev));
+ }
+
+ bool res = node.chainman->ActivateSnapshot(auto_infile, metadata,
+ in_memory_chainstate);
+
+ // Restore the old tip.
+ new_active.m_chain.SetTip(*tip);
+ return res;
}
#endif // BITCOIN_TEST_UTIL_CHAINSTATE_H
diff --git a/src/validation.cpp b/src/validation.cpp
--- a/src/validation.cpp
+++ b/src/validation.cpp
@@ -6523,65 +6523,78 @@
current_coinstip_cache_size * SNAPSHOT_CACHE_PERC));
}
- bool snapshot_ok = this->PopulateAndValidateSnapshot(*snapshot_chainstate,
- coins_file, metadata);
+ auto cleanup_bad_snapshot =
+ [&](const char *reason) EXCLUSIVE_LOCKS_REQUIRED(::cs_main) {
+ LogPrintf("[snapshot] activation failed - %s\n", reason);
+ this->MaybeRebalanceCaches();
+
+ // PopulateAndValidateSnapshot can return (in error) before the
+ // leveldb datadir has been created, so only attempt removal if we
+ // got that far.
+ if (auto snapshot_datadir = node::FindSnapshotChainstateDir()) {
+ // We have to destruct leveldb::DB in order to release the db
+ // lock, otherwise DestroyDB() (in DeleteCoinsDBFromDisk()) will
+ // fail. See `leveldb::~DBImpl()`. Destructing the chainstate
+ // (and so resetting the coinsviews object) does this.
+ snapshot_chainstate.reset();
+ bool removed = DeleteCoinsDBFromDisk(*snapshot_datadir,
+ /*is_snapshot=*/true);
+ if (!removed) {
+ AbortNode(strprintf(
+ "Failed to remove snapshot chainstate dir (%s). "
+ "Manually remove it before restarting.\n",
+ fs::PathToString(*snapshot_datadir)));
+ }
+ }
+ return false;
+ };
+ if (!this->PopulateAndValidateSnapshot(*snapshot_chainstate, coins_file,
+ metadata)) {
+ LOCK(::cs_main);
+ return cleanup_bad_snapshot("population failed");
+ }
+
+ // cs_main required for rest of snapshot activation.
+ LOCK(::cs_main);
+
+ // Do a final check to ensure that the snapshot chainstate is actually a
+ // more work chain than the active chainstate; a user could have loaded a
+ // snapshot very late in the IBD process, and we wouldn't want to load a
+ // useless chainstate.
+ if (!CBlockIndexWorkComparator()(ActiveTip(),
+ snapshot_chainstate->m_chain.Tip())) {
+ return cleanup_bad_snapshot("work does not exceed active chainstate");
+ }
// If not in-memory, persist the base blockhash for use during subsequent
// initialization.
if (!in_memory) {
- LOCK(::cs_main);
if (!node::WriteSnapshotBaseBlockhash(*snapshot_chainstate)) {
- snapshot_ok = false;
- }
- }
- if (!snapshot_ok) {
- LOCK(::cs_main);
- this->MaybeRebalanceCaches();
-
- // PopulateAndValidateSnapshot can return (in error) before the leveldb
- // datadir has been created, so only attempt removal if we got that far.
- if (auto snapshot_datadir = node::FindSnapshotChainstateDir()) {
- // We have to destruct leveldb::DB in order to release the db lock,
- // otherwise DestroyDB() (in DeleteCoinsDBFromDisk()) will fail. See
- // `leveldb::~DBImpl()`. Destructing the chainstate (and so
- // resetting the coinsviews object) does this.
- snapshot_chainstate.reset();
- bool removed =
- DeleteCoinsDBFromDisk(*snapshot_datadir, /*is_snapshot=*/true);
- if (!removed) {
- AbortNode(
- strprintf("Failed to remove snapshot chainstate dir (%s). "
- "Manually remove it before restarting.\n",
- fs::PathToString(*snapshot_datadir)));
- }
+ return cleanup_bad_snapshot("could not write base blockhash");
}
- return false;
}
- {
- LOCK(::cs_main);
- assert(!m_snapshot_chainstate);
- m_snapshot_chainstate.swap(snapshot_chainstate);
- const bool chaintip_loaded = m_snapshot_chainstate->LoadChainTip();
- assert(chaintip_loaded);
-
- // Transfer possession of the mempool to the snapshot chainstate.
- // Mempool is empty at this point because we're still in IBD.
- Assert(m_active_chainstate->m_mempool->size() == 0);
- Assert(!m_snapshot_chainstate->m_mempool);
- m_snapshot_chainstate->m_mempool = m_active_chainstate->m_mempool;
- m_active_chainstate->m_mempool = nullptr;
- m_active_chainstate = m_snapshot_chainstate.get();
- m_blockman.m_snapshot_height = this->GetSnapshotBaseHeight();
-
- LogPrintf("[snapshot] successfully activated snapshot %s\n",
- base_blockhash.ToString());
- LogPrintf("[snapshot] (%.2f MB)\n",
- m_snapshot_chainstate->CoinsTip().DynamicMemoryUsage() /
- (1000 * 1000));
+ assert(!m_snapshot_chainstate);
+ m_snapshot_chainstate.swap(snapshot_chainstate);
+ const bool chaintip_loaded = m_snapshot_chainstate->LoadChainTip();
+ assert(chaintip_loaded);
- this->MaybeRebalanceCaches();
- }
+ // Transfer possession of the mempool to the snapshot chainstate.
+ // Mempool is empty at this point because we're still in IBD.
+ Assert(m_active_chainstate->m_mempool->size() == 0);
+ Assert(!m_snapshot_chainstate->m_mempool);
+ m_snapshot_chainstate->m_mempool = m_active_chainstate->m_mempool;
+ m_active_chainstate->m_mempool = nullptr;
+ m_active_chainstate = m_snapshot_chainstate.get();
+ m_blockman.m_snapshot_height = this->GetSnapshotBaseHeight();
+
+ LogPrintf("[snapshot] successfully activated snapshot %s\n",
+ base_blockhash.ToString());
+ LogPrintf("[snapshot] (%.2f MB)\n",
+ m_snapshot_chainstate->CoinsTip().DynamicMemoryUsage() /
+ (1000 * 1000));
+
+ this->MaybeRebalanceCaches();
return true;
}
@@ -6643,6 +6656,16 @@
const AssumeutxoData &au_data = *maybe_au_data;
+ // This work comparison is a duplicate check with the one performed later in
+ // ActivateSnapshot(), but is done so that we avoid doing the long work of
+ // staging a snapshot that isn't actually usable.
+ if (WITH_LOCK(::cs_main, return !CBlockIndexWorkComparator()(
+ ActiveTip(), snapshot_start_block))) {
+ LogPrintf("[snapshot] activation failed - work does not exceed active "
+ "chainstate\n");
+ return false;
+ }
+
COutPoint outpoint;
Coin coin;
const uint64_t coins_count = metadata.m_coins_count;