From d52d6bc04213ce5f95b17c6d61422758e735432d Mon Sep 17 00:00:00 2001
From: Jason Volk <jason@zemos.net>
Date: Sun, 3 Jan 2021 21:42:23 -0800
Subject: [PATCH] ircd::db: Add conf item to disable file deletion on open; add
 to -safe mode diagnostic.

---
 construct/construct.cc     |  1 +
 include/ircd/db/database.h |  1 +
 ircd/db_database.cc        | 17 +++++++++++++++++
 3 files changed, 19 insertions(+)

diff --git a/construct/construct.cc b/construct/construct.cc
index f6fe9ce24..60f6a50b3 100644
--- a/construct/construct.cc
+++ b/construct/construct.cc
@@ -479,6 +479,7 @@ applyargs()
 		nocompact = true;
 		noautoapps = true;
 		ircd::server::enable.set("false");
+		ircd::db::auto_deletion.set("false");
 	}
 
 	if(single && !bootstrap)
diff --git a/include/ircd/db/database.h b/include/ircd/db/database.h
index 51c5ddfab..1235772b6 100644
--- a/include/ircd/db/database.h
+++ b/include/ircd/db/database.h
@@ -20,6 +20,7 @@ namespace ircd::db
 	extern conf::item<bool> open_repair;
 	extern conf::item<bool> open_slave;
 	extern conf::item<bool> auto_compact;
+	extern conf::item<bool> auto_deletion;
 
 	// General information
 	const std::string &name(const database &);
diff --git a/ircd/db_database.cc b/ircd/db_database.cc
index 18fc7f322..41864430e 100644
--- a/ircd/db_database.cc
+++ b/ircd/db_database.cc
@@ -70,6 +70,17 @@ ircd::db::auto_compact
 	{ "persist",  false                  },
 };
 
+/// Conf item toggles whether rocksdb is allowed to perform file deletion and
+/// garbage collection operations as normal. This can be prevented for
+/// diagnostic and safemode purposes.
+decltype(ircd::db::auto_deletion)
+ircd::db::auto_deletion
+{
+	{ "name",     "ircd.db.deletion.auto" },
+	{ "default",  true                    },
+	{ "persist",  false                   },
+};
+
 /// Conf item dictates whether databases will be opened in slave mode; this
 /// is a recent feature of RocksDB which may not be available. It allows two
 /// instances of a database, so long as only one is not opened as a slave.
@@ -1232,6 +1243,12 @@ try
 	return checkpointer;
 }()}
 {
+	// Disable file deletions here if ordered by the conf item (generally for
+	// -safe mode operation). If this can be done via DBOptions rather than
+	// here it would be better.
+	if(!db::auto_deletion)
+		db::fdeletions(*this, false);
+
 	// Conduct drops from schema changes. The database must be fully opened
 	// as if they were not dropped first, then we conduct the drop operation
 	// here. The drop operation has no effects until the database is next