From b0a773c922a46941b96bc312352370c92ba38179 Mon Sep 17 00:00:00 2001
From: Jason Volk <jason@zemos.net>
Date: Sat, 11 Jan 2020 19:14:32 -0800
Subject: [PATCH] ircd::db: Add conf item to repair on open.

---
 construct/construct.cc     |  7 +++++++
 include/ircd/db/database.h |  1 +
 ircd/db.cc                 | 21 ++++++++++++++++++++-
 3 files changed, 28 insertions(+), 1 deletion(-)

diff --git a/construct/construct.cc b/construct/construct.cc
index 5a73db419..cc3d1a635 100644
--- a/construct/construct.cc
+++ b/construct/construct.cc
@@ -24,6 +24,7 @@ bool nolisten;
 bool noautomod;
 bool checkdb;
 bool pitrecdb;
+bool repairdb;
 bool nojs;
 bool nodirect;
 bool noaio;
@@ -51,6 +52,7 @@ lgetopt opts[]
 	{ "noautomod",  &noautomod,     lgetopt::BOOL,    "Normal execution but without autoloading modules" },
 	{ "checkdb",    &checkdb,       lgetopt::BOOL,    "Perform complete checks of databases when opening" },
 	{ "pitrecdb",   &pitrecdb,      lgetopt::BOOL,    "Allow Point-In-Time-Recover if DB reports corruption after crash" },
+	{ "repairdb",   &repairdb,      lgetopt::BOOL,    "Perform full DB repair after deep block/file corruption." },
 	{ "nojs",       &nojs,          lgetopt::BOOL,    "Disable SpiderMonkey JS subsystem from initializing. (noop when not available)." },
 	{ "nodirect",   &nodirect,      lgetopt::BOOL,    "Disable direct IO (O_DIRECT) for unsupporting filesystems." },
 	{ "noaio",      &noaio,         lgetopt::BOOL,    "Disable the AIO interface in favor of traditional syscalls. " },
@@ -468,6 +470,11 @@ applyargs()
 	else
 		ircd::db::open_recover.set("absolute");
 
+	if(repairdb)
+		ircd::db::open_repair.set("true");
+	else
+		ircd::db::open_repair.set("false");
+
 	if(nodirect)
 		ircd::fs::fd::opts::direct_io_enable.set("false");
 	else
diff --git a/include/ircd/db/database.h b/include/ircd/db/database.h
index a5e603414..5656cb622 100644
--- a/include/ircd/db/database.h
+++ b/include/ircd/db/database.h
@@ -18,6 +18,7 @@ namespace ircd::db
 	// Broad conf items
 	extern conf::item<bool> open_check;
 	extern conf::item<std::string> open_recover;
+	extern conf::item<bool> open_repair;
 
 	// General information
 	const std::string &name(const database &);
diff --git a/ircd/db.cc b/ircd/db.cc
index 4fff07842..5fb5b95d5 100644
--- a/ircd/db.cc
+++ b/ircd/db.cc
@@ -383,6 +383,25 @@ ircd::db::open_recover
 	{ "persist",  false                   },
 };
 
+/// Conf item determines if database repair should occur (before open). This
+/// mechanism can be used when SST file corruption occurs which is too deep
+/// for log-based recovery. The affected blocks may be discarded; this risks
+/// destabilizing an application expecting the data in those blocks to exist.
+///
+/// !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
+///
+/// Use with caution.
+///
+/// !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
+///
+decltype(ircd::db::open_repair)
+ircd::db::open_repair
+{
+	{ "name",     "ircd.db.open.repair"  },
+	{ "default",  false                  },
+	{ "persist",  false                  },
+};
+
 void
 ircd::db::sync(database &d)
 {
@@ -1098,7 +1117,7 @@ try
 }
 ,fsck
 {
-	false
+	db::open_repair
 }
 ,read_only
 {