libcephsqlite: rework architecture and backend

This is a complete rewrite on top of SimpleRADOSStriper as well as the
API. The VFS is now a loadable extension as well.

Fixes: https://tracker.ceph.com/issues/40609
Signed-off-by: Patrick Donnelly <pdonnell@redhat.com>

CMakeLists.txt

@@ -281,12 +281,9 @@ endif(WITH_QATZIP)
 # needs mds and? XXX
 option(WITH_LIBCEPHFS "libcephfs client library" ON)
 
-find_package(SQLite3)
-if(SQLITE3_FOUND)
-  option(WITH_LIBCEPHSQLITE "libcephsqlite client library" ON)
-else()
-  message(WARNING "disabling WITH_LIBCEPHSQLITE, which depends on SQLite3")
-  set(WITH_LIBCEPHSQLITE OFF)
+option(WITH_LIBCEPHSQLITE "libcephsqlite client library" ON)
+if(WITH_LIBCEPHSQLITE)
+  find_package(SQLite3 REQUIRED)
 endif()
 
 # key-value store

cmake/modules/FindSQLite3.cmake

@@ -1,10 +1,12 @@
-find_path(SQLITE3_INCLUDE_DIR NAMES sqlite3.h PATHS /usr/include /usr/local/include)
-find_library(SQLITE3_LIBRARY NAMES sqlite3)
+find_path(SQLite3_INCLUDE_DIR NAMES sqlite3.h)
+find_library(SQLite3_LIBRARY NAMES sqlite3 sqlite)
 
 include(FindPackageHandleStandardArgs)
-find_package_handle_standard_args(SQLITE3 DEFAULT_MSG SQLITE3_LIBRARY SQLITE3_INCLUDE_DIR)
+find_package_handle_standard_args(SQLite3 DEFAULT_MSG SQLite3_LIBRARY SQLite3_INCLUDE_DIR)
 
-if(SQLITE3_FOUND)
-  set(SQLITE3_LIBRARIES ${SQLITE3_LIBRARY})
-  set(SQLITE3_INCLUDE_DIRS ${SQLITE3_INCLUDE_DIR})
+if(NOT TARGET SQLite3::SQLite3)
+  add_library(SQLite3::SQLite3 UNKNOWN IMPORTED)
+  set_target_properties(SQLite3::SQLite3 PROPERTIES
+      IMPORTED_LOCATION "${SQLite3_LIBRARY}"
+      INTERFACE_INCLUDE_DIRECTORIES "${SQLite3_INCLUDE_DIR}")
 endif()

src/CMakeLists.txt

@@ -804,16 +804,9 @@ if(WITH_LIBCEPHFS)
 endif(WITH_LIBCEPHFS)
 
 if(WITH_LIBCEPHSQLITE)
-  set(libcephsqlite_srcs libcephsqlite.cc)
-  add_library(cephsqlite ${CEPH_SHARED} ${libcephsqlite_srcs})
-  set_target_properties(cephsqlite PROPERTIES COMPILE_FLAGS "-I${SQLITE3_INCLUDE_DIRS}")
-  target_link_libraries(cephsqlite radosstriper librados ${SQLITE3_LIBRARIES} ${EXTRALIBS})
-  if(ENABLE_SHARED)
-    set_target_properties(cephsqlite PROPERTIES
-      OUTPUT_NAME cephsqlite
-      VERSION 1.0.0
-      SOVERSION 1)
-  endif(ENABLE_SHARED)
+  set(cephsqlite_srcs libcephsqlite.cc SimpleRADOSStriper.cc)
+  add_library(cephsqlite ${CEPH_SHARED} ${cephsqlite_srcs})
+  target_link_libraries(cephsqlite PRIVATE cls_lock_client librados ceph-common SQLite3::SQLite3 ${EXTRALIBS})
   install(TARGETS cephsqlite DESTINATION ${CMAKE_INSTALL_LIBDIR})
 endif(WITH_LIBCEPHSQLITE)
 

src/common/options.cc

@@ -5594,6 +5594,28 @@ std::vector<Option> get_global_options() {
     .set_description("Size of thread pool for ASIO completions")
     .add_tag("osd"),
 
+    Option("cephsqlite_lock_renewal_interval", Option::TYPE_MILLISECS, Option::LEVEL_ADVANCED)
+    .add_see_also("cephsqlite_lock_renewal_timeout")
+    .add_tag("client")
+    .set_default(2000)
+    .set_description("number of milliseconds before lock is renewed")
+    .set_min(100)
+    ,
+
+    Option("cephsqlite_lock_renewal_timeout", Option::TYPE_MILLISECS, Option::LEVEL_ADVANCED)
+    .add_see_also("cephsqlite_lock_renewal_interval")
+    .add_tag("client")
+    .set_default(30000)
+    .set_description("number of milliseconds before transaction lock times out")
+    .set_long_description("The amount of time before a running libcephsqlite VFS connection has to renew a lock on the database before the lock is automatically lost. If the lock is lost, the VFS will abort the process to prevent database corruption.")
+    .set_min(100),
+
+    Option("cephsqlite_blocklist_dead_locker", Option::TYPE_BOOL, Option::LEVEL_ADVANCED)
+    .add_tag("client")
+    .set_default(true)
+    .set_description("blocklist the last dead owner of the database lock")
+    .set_long_description("Require that the Ceph SQLite VFS blocklist the last dead owner of the database when cleanup was incomplete. DO NOT CHANGE THIS UNLESS YOU UNDERSTAND THE RAMIFICATIONS. CORRUPTION MAY RESULT."),
+
     // ----------------------------
     // Crimson specific options
 

src/common/subsys.h

@@ -81,3 +81,4 @@ SUBSYS(eventtrace, 1, 5)
 SUBSYS(prioritycache, 1, 5)
 SUBSYS(test, 0, 5)
 SUBSYS(cephfs_mirror, 0, 5)
+SUBSYS(cephsqlite, 0, 5)

src/include/CMakeLists.txt

@@ -1,3 +1,7 @@
+install(FILES
+  libcephsqlite.h
+  DESTINATION ${CMAKE_INSTALL_INCLUDEDIR})
+
 install(FILES
   rados/librados.h
   rados/rados_types.h

src/include/libcephsqlite.h

@@ -0,0 +1,67 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab
+
+/*
+ * Ceph - scalable distributed file system
+ *
+ * Copyright (C) 2021 Red Hat, Inc.
+ *
+ * This is free software; you can redistribute it and/or modify it under the
+ * terms of the GNU Lesser General Public License version 2.1, as published by
+ * the Free Software Foundation.  See file COPYING.
+ *
+ */
+
+#ifndef LIBCEPHSQLITE_H
+#define LIBCEPHSQLITE_H
+
+/* This loadable extension does not generally require using this header. It is
+ * here to allow controlling which version of the library is linked in. See
+ * also sqlite3_cephsqlite_init below. Additionally, you may specify which
+ * CephContext to use rather than the library instantiating its own and using
+ * whatever the default credential is.
+ */
+
+#include <sqlite3.h>
+
+#ifdef _WIN32
+#  define LIBCEPHSQLITE_API __declspec(dllexport)
+#else
+#  define LIBCEPHSQLITE_API extern "C"
+#endif
+
+/* This is the SQLite entry point when loaded as a dynamic library. You also
+ * need to ensure SQLite calls this method when using libcephsqlite as a static
+ * library or a dynamic library linked at compile time. For the latter case,
+ * you can do this by:
+ *
+ *   sqlite3_auto_extension((void (*)())sqlite3_cephsqlite_init);
+ *   sqlite3* db = nullptr;
+ *   int rc = sqlite3_open_v2(":memory:", &db, SQLITE_OPEN_READWRITE, nullptr);
+ *   if (rc == SQLITE_DONE) {
+ *     sqlite3_close(db);
+ *   } else {
+ *     // failure
+ *   }
+ *
+ * The throwaway database created (name == "") is a memory database opened so
+ * that SQLite runs the libcephsqlite initialization routine to register the
+ * VFS. AFter that's done, the VFS is available for a future database open with
+ * the VFS set to "ceph":
+ *
+ *   sqlite3_open_v2("foo:bar/baz.db", &db, SQLITE_OPEN_READWRITE, "ceph");
+ *
+ * You MUST do this before calling any other libcephsqlite routine so that
+ * sqlite3 can pass its API routines to the libcephsqlite extension.
+ */
+
+LIBCEPHSQLITE_API int sqlite3_cephsqlite_init(sqlite3* db, char** err, const sqlite3_api_routines* api);
+
+/* If you prefer to have libcephsqlite use a CephContext managed by your
+ * application, use this routine to set that. libcephsqlite can only have one
+ * context globally.
+ */
+
+LIBCEPHSQLITE_API int cephsqlite_setcct(class CephContext* cct, char** ident);
+
+#endif

src/libcephsqlite.h

@@ -1,24 +0,0 @@
-#ifndef LIBCEPHSQLITE_H
-#define LIBCEPHSQLITE_H
-
-#include "rados/librados.hpp"
-
-struct sqlite3;
-
-extern "C"
-sqlite3 *ceph_sqlite3_open(
-  librados::Rados &cluster,
-  const char *dbname,           /* eg. "sql" instead of "sql.db" */
-  const char *rados_namespace,
-  int ceph_pool_id,
-  bool must_create
-);
-
-extern "C"
-void ceph_sqlite3_set_db_params(
-  const char *dbname,           /* eg. "sql" instead of "sql.db" */
-  int stripe_count,
-  int obj_size
-);
-
-#endif