Merge bitcoin/bitcoin#30255: log: use error level for critical log messages

fae3a1f log: use error level for critical log messages (MarcoFalke)

Pull request description:

  This picks up the first commit from bitcoin/bitcoin#29231, but extends it to also cover cases that were missed in it.

  As per https://github.com/bitcoin/bitcoin/blob/master/doc/developer-notes.md#logging, LogError should be used for severe problems that require the node to shut down.

ACKs for top commit:
  stickies-v:
    re-ACK fae3a1f, I'm ~0 on the latest force push as `user_error` was already logged at the right level through `GetNotifications().fatalError(user_error);` so I'd be in favour of deduplicating/cleaning up this logging logic but can be done in follow-up.
  kevkevinpal:
    ACK [fae3a1f](bitcoin/bitcoin@fae3a1f)
  achow101:
    ACK fae3a1f

Tree-SHA512: 3f99fd25d5a204d570a42d8fb2b450439aad7685692f9594cc813d97253c4df172a6ff3cf818959bfcf25dfcf8ee9a9c9ccc6028fcfcecdb47591e18c77ef246

Author: achow101

src/coins.cpp

@@ -361,7 +361,7 @@ static bool ExecuteBackedWrapper(Func func, const std::vector<std::function<void
         for (const auto& f : err_callbacks) {
             f();
         }
-        LogPrintf("Error reading from database: %s\n", e.what());
+        LogError("Error reading from database: %s\n", e.what());
         // Starting the shutdown sequence and returning false to the caller would be
         // interpreted as 'entry not found' (as opposed to unable to read data), and
         // could lead to invalid interpretation. Just exit immediately, as we can't

src/init.cpp

@@ -409,7 +409,7 @@ static void HandleSIGHUP(int)
 static BOOL WINAPI consoleCtrlHandler(DWORD dwCtrlType)
 {
     if (!(*Assert(g_shutdown))()) {
-        LogPrintf("Error: failed to send shutdown signal on Ctrl-C\n");
+        LogError("Failed to send shutdown signal on Ctrl-C\n");
         return false;
     }
     Sleep(INFINITE);
@@ -840,7 +840,7 @@ std::set<BlockFilterType> g_enabled_filter_types;
     // Since LogPrintf may itself allocate memory, set the handler directly
     // to terminate first.
     std::set_new_handler(std::terminate);
-    LogPrintf("Error: Out of memory. Terminating.\n");
+    LogError("Out of memory. Terminating.\n");
 
     // The log was successful, terminate now.
     std::terminate();
@@ -1175,9 +1175,9 @@ bool AppInitMain(NodeContext& node, interfaces::BlockAndHeaderTipInfo* tip_info)
     scheduler.scheduleEvery([&args, &node]{
         constexpr uint64_t min_disk_space = 50 << 20; // 50 MB
         if (!CheckDiskSpace(args.GetBlocksDirPath(), min_disk_space)) {
-            LogPrintf("Shutting down due to lack of disk space!\n");
+            LogError("Shutting down due to lack of disk space!\n");
             if (!(*Assert(node.shutdown))()) {
-                LogPrintf("Error: failed to send shutdown signal after disk space check\n");
+                LogError("Failed to send shutdown signal after disk space check\n");
             }
         }
     }, std::chrono::minutes{5});
@@ -1582,7 +1582,7 @@ bool AppInitMain(NodeContext& node, interfaces::BlockAndHeaderTipInfo* tip_info)
             try {
                 return f();
             } catch (const std::exception& e) {
-                LogPrintf("%s\n", e.what());
+                LogError("%s\n", e.what());
                 return std::make_tuple(node::ChainstateLoadStatus::FAILURE, _("Error opening block database"));
             }
         };
@@ -1614,10 +1614,10 @@ bool AppInitMain(NodeContext& node, interfaces::BlockAndHeaderTipInfo* tip_info)
                 if (fRet) {
                     do_reindex = true;
                     if (!Assert(node.shutdown)->reset()) {
-                        LogPrintf("Internal error: failed to reset shutdown signal.\n");
+                        LogError("Internal error: failed to reset shutdown signal.\n");
                     }
                 } else {
-                    LogPrintf("Aborted block database rebuild. Exiting.\n");
+                    LogError("Aborted block database rebuild. Exiting.\n");
                     return false;
                 }
             } else {
@@ -1752,7 +1752,7 @@ bool AppInitMain(NodeContext& node, interfaces::BlockAndHeaderTipInfo* tip_info)
         if (args.GetBoolArg("-stopafterblockimport", DEFAULT_STOPAFTERBLOCKIMPORT)) {
             LogPrintf("Stopping after block import\n");
             if (!(*Assert(node.shutdown))()) {
-                LogPrintf("Error: failed to send shutdown signal after finishing block import\n");
+                LogError("Failed to send shutdown signal after finishing block import\n");
             }
             return;
         }

src/node/interfaces.cpp

@@ -125,7 +125,7 @@ class NodeImpl : public Node
     void startShutdown() override
     {
         if (!(*Assert(Assert(m_context)->shutdown))()) {
-            LogPrintf("Error: failed to send shutdown signal\n");
+            LogError("Failed to send shutdown signal\n");
         }
         // Stop RPC for clean shutdown if any of waitfor* commands is executed.
         if (args().GetBoolArg("-server", false)) {

src/node/kernel_notifications.cpp

@@ -63,7 +63,7 @@ kernel::InterruptResult KernelNotifications::blockTip(SynchronizationState state
     uiInterface.NotifyBlockTip(state, &index);
     if (m_stop_at_height && index.nHeight >= m_stop_at_height) {
         if (!m_shutdown()) {
-            LogPrintf("Error: failed to send shutdown signal after reaching stop height\n");
+            LogError("Failed to send shutdown signal after reaching stop height\n");
         }
         return kernel::Interrupted{};
     }

src/validation.cpp

@@ -5967,8 +5967,8 @@ SnapshotCompletionResult ChainstateManager::MaybeCompleteSnapshotValidation()
             PACKAGE_NAME, snapshot_tip_height, snapshot_base_height, snapshot_base_height, PACKAGE_BUGREPORT
         );
 
-        LogPrintf("[snapshot] !!! %s\n", user_error.original);
-        LogPrintf("[snapshot] deleting snapshot, reverting to validated chain, and stopping node\n");
+        LogError("[snapshot] !!! %s\n", user_error.original);
+        LogError("[snapshot] deleting snapshot, reverting to validated chain, and stopping node\n");
 
         m_active_chainstate = m_ibd_chainstate.get();
         m_snapshot_chainstate->m_disabled = true;
@@ -6320,7 +6320,7 @@ bool ChainstateManager::ValidatedSnapshotCleanup()
                                    fs::path p_old,
                                    fs::path p_new,
                                    const fs::filesystem_error& err) {
-        LogPrintf("Error renaming path (%s) -> (%s): %s\n",
+        LogError("[snapshot] Error renaming path (%s) -> (%s): %s\n",
                   fs::PathToString(p_old), fs::PathToString(p_new), err.what());
         GetNotifications().fatalError(strprintf(_(
             "Rename of '%s' -> '%s' failed. "