OpenZFS 7431 - ZFS Channel Programs

Authored by: Chris Williamson <[email protected]>
Reviewed by: Matthew Ahrens <[email protected]>
Reviewed by: George Wilson <[email protected]>
Reviewed by: John Kennedy <[email protected]>
Reviewed by: Dan Kimmel <[email protected]>
Approved by: Garrett D'Amore <[email protected]>
Ported-by: Don Brady <[email protected]>
Ported-by: John Kennedy <[email protected]>

OpenZFS-issue: https://www.illumos.org/issues/7431
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/dfc11533

Porting Notes:
* The CLI long option arguments for '-t' and '-m' don't parse on linux
* Switched from kmem_alloc to vmem_alloc in zcp_lua_alloc
* Lua implementation is built as its own module (zlua.ko)
* Lua headers consumed directly by zfs code moved to 'include/sys/lua/'
* There is no native setjmp/longjump available in stock Linux kernel.
  Brought over implementations from illumos and FreeBSD
* The get_temporary_prop() was adapted due to VFS platform differences
* Use of inline functions in lua parser to reduce stack usage per C call
* Skip some ZFS Test Suite ZCP tests on sparc64 to avoid stack overflow

1 files changed, 146 insertions, 0 deletions

diff --git a/include/sys/zcp.h b/include/sys/zcp.h
new file mode 100644
index 000000000..ca9719ecf
--- /dev/null
+++ b/include/sys/zcp.h
@@ -0,0 +1,146 @@
+/*
+ * CDDL HEADER START
+ *
+ * This file and its contents are supplied under the terms of the
+ * Common Development and Distribution License ("CDDL"), version 1.0.
+ * You may only use this file in accordance with the terms of version
+ * 1.0 of the CDDL.
+ *
+ * A full copy of the text of the CDDL should have accompanied this
+ * source.  A copy of the CDDL is also available via the Internet at
+ * http://www.illumos.org/license/CDDL.
+ *
+ * CDDL HEADER END
+ */
+
+/*
+ * Copyright (c) 2016 by Delphix. All rights reserved.
+ */
+
+#ifndef _SYS_ZCP_H
+#define	_SYS_ZCP_H
+
+#include <sys/dmu_tx.h>
+#include <sys/dsl_pool.h>
+
+#include <sys/lua/lua.h>
+#include <sys/lua/lualib.h>
+#include <sys/lua/lauxlib.h>
+
+#ifdef	__cplusplus
+extern "C" {
+#endif
+
+#define	ZCP_RUN_INFO_KEY "runinfo"
+
+extern uint64_t zfs_lua_max_instrlimit;
+extern uint64_t zfs_lua_max_memlimit;
+
+int zcp_argerror(lua_State *, int, const char *, ...);
+
+int zcp_eval(const char *, const char *, uint64_t, uint64_t, nvpair_t *,
+    nvlist_t *);
+
+int zcp_load_list_lib(lua_State *);
+
+int zcp_load_synctask_lib(lua_State *, boolean_t);
+
+typedef void (zcp_cleanup_t)(void *);
+
+typedef struct zcp_run_info {
+	dsl_pool_t	*zri_pool;
+
+	/*
+	 * An estimate of the total ammount of space consumed by all
+	 * synctasks we have successfully performed so far in this
+	 * channel program. Used to generate ENOSPC errors for syncfuncs.
+	 */
+	int		zri_space_used;
+
+	/*
+	 * The credentials of the thread which originally invoked the channel
+	 * program. Since channel programs are always invoked from the synctask
+	 * thread they should always do permissions checks against this cred
+	 * rather than the 'current' thread's.
+	 */
+	cred_t		*zri_cred;
+
+	/*
+	 * The tx in which this channel program is running.
+	 */
+	dmu_tx_t	*zri_tx;
+
+	/*
+	 * The maximum number of Lua instructions the channel program is allowed
+	 * to execute. If it takes longer than this it will time out. A value
+	 * of 0 indicates no instruction limit.
+	 */
+	uint64_t	zri_maxinstrs;
+
+	/*
+	 * The number of Lua instructions the channel program has executed.
+	 */
+	uint64_t	zri_curinstrs;
+
+	/*
+	 * Boolean indicating whether or not the channel program exited
+	 * because it timed out.
+	 */
+	boolean_t	zri_timed_out;
+
+	/*
+	 * The currently registered cleanup function, which will be called
+	 * with the stored argument if a fatal error occurs.
+	 */
+	zcp_cleanup_t	*zri_cleanup;
+	void		*zri_cleanup_arg;
+} zcp_run_info_t;
+
+zcp_run_info_t *zcp_run_info(lua_State *);
+void zcp_register_cleanup(lua_State *, zcp_cleanup_t, void *);
+void zcp_clear_cleanup(lua_State *);
+void zcp_cleanup(lua_State *);
+
+/*
+ * Argument parsing routines for channel program callback functions.
+ */
+typedef struct zcp_arg {
+	/*
+	 * The name of this argument. For keyword arguments this is the name
+	 * functions will use to set the argument. For positional arguments
+	 * the name has no programatic meaning, but will appear in error
+	 * messages and help output.
+	 */
+	const char *za_name;
+
+	/*
+	 * The Lua type this argument should have (e.g. LUA_TSTRING,
+	 * LUA_TBOOLEAN) see the lua_type() function documentation for a
+	 * complete list. Calling a function with an argument that does
+	 * not match the expected type will result in the program terminating.
+	 */
+	const int za_lua_type;
+} zcp_arg_t;
+
+void zcp_parse_args(lua_State *, const char *, const zcp_arg_t *,
+    const zcp_arg_t *);
+int zcp_nvlist_to_lua(lua_State *, nvlist_t *, char *, int);
+int zcp_dataset_hold_error(lua_State *, dsl_pool_t *, const char *, int);
+struct dsl_dataset *zcp_dataset_hold(lua_State *, dsl_pool_t *,
+    const char *, void *);
+
+typedef int (zcp_lib_func_t)(lua_State *);
+typedef struct zcp_lib_info {
+	const char *name;
+	zcp_lib_func_t *func;
+	const zcp_arg_t pargs[4];
+	const zcp_arg_t kwargs[2];
+} zcp_lib_info_t;
+
+int zcp_nvlist_to_lua(lua_State *, nvlist_t *, char *, int);
+
+#ifdef	__cplusplus
+}
+#endif
+
+#endif	/* _SYS_ZCP_H */