Re: [tarantool-patches] Re: [PATCH v1 1/1] box: support reload whole module

[Kirill Shcherbatov <kshcherbatov@tarantool.org>]

> During our verbal discussion with Kirill, he noticed that the fact that
> box.schema.func.reload() reloads the whole module when it is passed a
> function name is rather confusing: the user may not know that and call
> box.schema.func.reload() once per each used function, in which case he
> will effectively reload the whole module that contains those functions
> multiple times, which is pointless. Turns out Kirill isn't the only one
> who finds such an API weird, see
> 
>   https://github.com/tarantool/tarantool/issues/910#issuecomment-331435227
> 
> I talked to Kostja and he doesn't mind banning this API, i.e. making
> box.schema.func.reload() interpret its argument only as a module name.
> 
> So let's rework this patch so that box_func_reload() directly calls
> module_reload(), and remove func_reload() altogether. As for the access
> checks, box_func_reload() should work only if the caller has the global
> execute privilege.

Closes #2946.

@TarantoolBot document
Title: fixed module reload
There was a bug in tarantool documentation:
https://tarantool.io/en/doc/1.7/book/box/
box_schema/#lua-function.box.schema.func.reload
Now it is allowed to reload all functions in loadable
module via one method. Legacy method including finction
name is forbidden.
box.schema.func.reload("utils")       -- ok since now
box.schema.func.reload("utils.func1") -- forbidden since now

Global reload is still unsupported because it seems
to be useless.
box.schema.func.reload()              -- invalid!
---
https://github.com/tarantool/tarantool/compare/kshch/gh-2946-module-reload
https://github.com/tarantool/tarantool/issues/2946

 src/box/call.c                | 23 +++++++++++++----------
 src/box/call.h                |  9 ++++++++-
 src/box/errcode.h             |  1 +
 src/box/func.c                | 16 ----------------
 src/box/func.h                | 11 ++++++++++-
 src/box/lua/call.c            |  6 +++---
 src/box/lua/schema.lua        |  2 +-
 test/box/func_reload.result   | 23 ++++++++---------------
 test/box/func_reload.test.lua | 14 ++++++--------
 test/box/misc.result          |  1 +
 10 files changed, 51 insertions(+), 55 deletions(-)

diff --git a/src/box/call.c b/src/box/call.c
index 438be19..b9750c5 100644
--- a/src/box/call.c
+++ b/src/box/call.c
@@ -132,20 +132,23 @@ box_c_call(struct func *func, struct call_request *request, struct port *port)
 }
 
 int
-box_func_reload(const char *name)
+box_module_reload(const char *name)
 {
-	size_t name_len = strlen(name);
-	struct func *func = NULL;
-	if ((access_check_func(name, name_len, &func)) != 0)
-		return -1;
-	if (func == NULL) {
-		diag_set(ClientError, ER_NO_SUCH_FUNCTION, name);
+	struct credentials *credentials = effective_user();
+	if ((credentials->universal_access & (PRIV_X | PRIV_U)) !=
+	    (PRIV_X | PRIV_U)) {
+		struct user *user = user_find(credentials->uid);
+		if (user != NULL)
+			diag_set(AccessDeniedError, priv_name(PRIV_U),
+				 schema_object_name(SC_UNIVERSE), "",
+				 user->def->name);
 		return -1;
 	}
-	if (func->def->language != FUNC_LANGUAGE_C || func->func == NULL)
-		return 0; /* Nothing to do */
-	if (func_reload(func) == 0)
+	struct module *module = NULL;
+	if (module_reload(name, name + strlen(name), &module) == 0 &&
+	    module != NULL)
 		return 0;
+	diag_set(ClientError, ER_NO_SUCH_MODULE, name);
 	return -1;
 }
 
diff --git a/src/box/call.h b/src/box/call.h
index eabba69..1b54551 100644
--- a/src/box/call.h
+++ b/src/box/call.h
@@ -42,8 +42,15 @@ struct box_function_ctx {
 	struct port *port;
 };
 
+/**
+ * Reload loadable module by name.
+ *
+ * @param name of the module to reload.
+ * @retval -1 on error.
+ * @retval 0 on success.
+ */
 int
-box_func_reload(const char *name);
+box_module_reload(const char *name);
 
 int
 box_process_call(struct call_request *request, struct port *port);
diff --git a/src/box/errcode.h b/src/box/errcode.h
index c76018c..64f9af1 100644
--- a/src/box/errcode.h
+++ b/src/box/errcode.h
@@ -215,6 +215,7 @@ struct errcode_record {
 	/*160 */_(ER_ACTION_MISMATCH,		"Field %d contains %s on conflict action, but %s in index parts") \
 	/*161 */_(ER_VIEW_MISSING_SQL,		"Space declared as a view must have SQL statement") \
 	/*162 */_(ER_FOREIGN_KEY_CONSTRAINT,	"Can not commit transaction: deferred foreign keys violations are not resolved") \
+	/*163 */_(ER_NO_SUCH_MODULE,		"Module '%s' does not exist") \
 
 /*
  * !IMPORTANT! Please follow instructions at start of the file
diff --git a/src/box/func.c b/src/box/func.c
index dfbc5f3..a817851 100644
--- a/src/box/func.c
+++ b/src/box/func.c
@@ -298,9 +298,6 @@ module_sym(struct module *module, const char *name)
 	return f;
 }
 
-/*
- * Reload a dso.
- */
 int
 module_reload(const char *package, const char *package_end, struct module **module)
 {
@@ -436,19 +433,6 @@ func_load(struct func *func)
 }
 
 int
-func_reload(struct func *func)
-{
-	struct func_name name;
-	func_split_name(func->def->name, &name);
-	struct module *module = NULL;
-	if (module_reload(name.package, name.package_end, &module) != 0) {
-		diag_log();
-		return -1;
-	}
-	return 0;
-}
-
-int
 func_call(struct func *func, box_function_ctx_t *ctx, const char *args,
 	  const char *args_end)
 {
diff --git a/src/box/func.h b/src/box/func.h
index 0957546..8dcd61d 100644
--- a/src/box/func.h
+++ b/src/box/func.h
@@ -113,8 +113,17 @@ int
 func_call(struct func *func, box_function_ctx_t *ctx, const char *args,
 	  const char *args_end);
 
+/**
+ * Reload dynamically loadable module.
+ *
+ * @param package name begin pointer.
+ * @param package_end package_end name end pointer.
+ * @param[out] module a pointer to store module object on success.
+ * @retval -1 on error.
+ * @retval 0 on success.
+ */
 int
-func_reload(struct func *func);
+module_reload(const char *package, const char *package_end, struct module **module);
 
 #if defined(__cplusplus)
 } /* extern "C" */
diff --git a/src/box/lua/call.c b/src/box/lua/call.c
index 8f3461a..d20cbbb 100644
--- a/src/box/lua/call.c
+++ b/src/box/lua/call.c
@@ -458,10 +458,10 @@ box_lua_eval(struct call_request *request, struct port *port)
 }
 
 static int
-lbox_func_reload(lua_State *L)
+lbox_module_reload(lua_State *L)
 {
 	const char *name = luaL_checkstring(L, 1);
-	if (box_func_reload(name) != 0)
+	if (box_module_reload(name) != 0)
 		return luaT_error(L);
 	return 0;
 }
@@ -469,7 +469,7 @@ lbox_func_reload(lua_State *L)
 static const struct luaL_Reg boxlib_internal[] = {
 	{"call_loadproc",  lbox_call_loadproc},
 	{"sql_create_function",  lbox_sql_create_function},
-	{"func_reload", lbox_func_reload},
+	{"module_reload", lbox_module_reload},
 	{NULL, NULL}
 };
 
diff --git a/src/box/lua/schema.lua b/src/box/lua/schema.lua
index 87c79bd..ab8072c 100644
--- a/src/box/lua/schema.lua
+++ b/src/box/lua/schema.lua
@@ -1951,7 +1951,7 @@ function box.schema.func.exists(name_or_id)
     return tuple ~= nil
 end
 
-box.schema.func.reload = internal.func_reload
+box.schema.func.reload = internal.module_reload
 
 box.internal.collation = {}
 box.internal.collation.create = function(name, coll_type, locale, opts)
diff --git a/test/box/func_reload.result b/test/box/func_reload.result
index 5aeb85c..b024cd1 100644
--- a/test/box/func_reload.result
+++ b/test/box/func_reload.result
@@ -51,8 +51,9 @@ fio.symlink(reload1_path, reload_path)
 - true
 ...
 --check not fail on non-load func
-box.schema.func.reload("reload.foo")
+box.schema.func.reload("reload")
 ---
+- error: Module 'reload' does not exist
 ...
 -- test of usual case reload. No hanging calls
 box.space.test:insert{0}
@@ -74,7 +75,7 @@ fio.symlink(reload2_path, reload_path)
 ---
 - true
 ...
-box.schema.func.reload("reload.foo")
+box.schema.func.reload("reload")
 ---
 ...
 c:call("reload.foo")
@@ -98,7 +99,7 @@ fio.symlink(reload1_path, reload_path)
 ---
 - true
 ...
-box.schema.func.reload("reload.foo")
+box.schema.func.reload("reload")
 ---
 ...
 fibers = 10
@@ -111,7 +112,7 @@ while box.space.test:count() < fibers do fiber.sleep(0.001) end
 ---
 ...
 -- double reload doesn't fail waiting functions
-box.schema.func.reload("reload.foo")
+box.schema.func.reload("reload")
 ---
 ...
 _ = fio.unlink(reload_path)
@@ -121,7 +122,7 @@ fio.symlink(reload2_path, reload_path)
 ---
 - true
 ...
-box.schema.func.reload("reload.foo")
+box.schema.func.reload("reload")
 ---
 ...
 c:call("reload.foo")
@@ -208,7 +209,7 @@ _ = fiber.create(function() ch:put(c:call("reload.test_reload")) end)
 while s:get({1}) == nil do fiber.yield(0.0001) end
 ---
 ...
-box.schema.func.reload("reload.test_reload")
+box.schema.func.reload("reload")
 ---
 ...
 _ = fiber.create(function() ch:put(c:call("reload.test_reload")) end)
@@ -242,14 +243,6 @@ fio.symlink(reload1_path, reload_path)
 ---
 - true
 ...
-s, e = pcall(box.schema.func.reload, "reload.test_reload")
----
-...
-s, string.find(tostring(e), 'test_reload_fail') ~= nil
----
-- false
-- true
-...
 c:call("reload.test_reload")
 ---
 - [[2]]
@@ -273,5 +266,5 @@ box.schema.func.reload()
 ...
 box.schema.func.reload("non-existing")
 ---
-- error: Function 'non-existing' does not exist
+- error: Module 'non-existing' does not exist
 ...
diff --git a/test/box/func_reload.test.lua b/test/box/func_reload.test.lua
index dc56d84..8906898 100644
--- a/test/box/func_reload.test.lua
+++ b/test/box/func_reload.test.lua
@@ -20,7 +20,7 @@ _ = fio.unlink(reload_path)
 fio.symlink(reload1_path, reload_path)
 
 --check not fail on non-load func
-box.schema.func.reload("reload.foo")
+box.schema.func.reload("reload")
 
 -- test of usual case reload. No hanging calls
 box.space.test:insert{0}
@@ -29,7 +29,7 @@ box.space.test:delete{0}
 _ = fio.unlink(reload_path)
 fio.symlink(reload2_path, reload_path)
 
-box.schema.func.reload("reload.foo")
+box.schema.func.reload("reload")
 c:call("reload.foo")
 box.space.test:select{}
 box.space.test:truncate()
@@ -37,18 +37,18 @@ box.space.test:truncate()
 -- test case with hanging calls
 _ = fio.unlink(reload_path)
 fio.symlink(reload1_path, reload_path)
-box.schema.func.reload("reload.foo")
+box.schema.func.reload("reload")
 
 fibers = 10
 for i = 1, fibers do fiber.create(function() c:call("reload.foo", {i}) end) end
 
 while box.space.test:count() < fibers do fiber.sleep(0.001) end
 -- double reload doesn't fail waiting functions
-box.schema.func.reload("reload.foo")
+box.schema.func.reload("reload")
 
 _ = fio.unlink(reload_path)
 fio.symlink(reload2_path, reload_path)
-box.schema.func.reload("reload.foo")
+box.schema.func.reload("reload")
 c:call("reload.foo")
 
 while box.space.test:count() < 2 * fibers + 1 do fiber.sleep(0.001) end
@@ -71,7 +71,7 @@ _ = fio.unlink(reload_path)
 fio.symlink(reload2_path, reload_path)
 _ = fiber.create(function() ch:put(c:call("reload.test_reload")) end)
 while s:get({1}) == nil do fiber.yield(0.0001) end
-box.schema.func.reload("reload.test_reload")
+box.schema.func.reload("reload")
 _ = fiber.create(function() ch:put(c:call("reload.test_reload")) end)
 ch:get()
 ch:get()
@@ -82,8 +82,6 @@ box.schema.user.grant('guest', 'execute', 'function', 'reload.test_reload_fail')
 c:call("reload.test_reload_fail")
 _ = fio.unlink(reload_path)
 fio.symlink(reload1_path, reload_path)
-s, e = pcall(box.schema.func.reload, "reload.test_reload")
-s, string.find(tostring(e), 'test_reload_fail') ~= nil
 c:call("reload.test_reload")
 c:call("reload.test_reload_fail")
 
diff --git a/test/box/misc.result b/test/box/misc.result
index a00d033..777b40b 100644
--- a/test/box/misc.result
+++ b/test/box/misc.result
@@ -487,6 +487,7 @@ t;
   160: box.error.ACTION_MISMATCH
   161: box.error.VIEW_MISSING_SQL
   162: box.error.FOREIGN_KEY_CONSTRAINT
+  163: box.error.NO_SUCH_MODULE
 ...
 test_run:cmd("setopt delimiter ''");
 ---
-- 
2.7.4