1 /*
2  * CDDL HEADER START
3  *
4  * This file and its contents are supplied under the terms of the
5  * Common Development and Distribution License ("CDDL"), version 1.0.
6  * You may only use this file in accordance with the terms of version
7  * 1.0 of the CDDL.
8  *
9  * A full copy of the text of the CDDL should have accompanied this
10  * source.  A copy of the CDDL is also available via the Internet at
11  * http://www.illumos.org/license/CDDL.
12  *
13  * CDDL HEADER END
14  */
15 
16 /*
17  * Copyright (c) 2016, 2017 by Delphix. All rights reserved.
18  * Copyright (c) 2019, 2020 by Christian Schwarz. All rights reserved.
19  * Copyright 2020 Joyent, Inc.
20  */
21 
22 #include <sys/lua/lua.h>
23 #include <sys/lua/lauxlib.h>
24 
25 #include <sys/zcp.h>
26 #include <sys/zcp_set.h>
27 #include <sys/dsl_dir.h>
28 #include <sys/dsl_pool.h>
29 #include <sys/dsl_prop.h>
30 #include <sys/dsl_synctask.h>
31 #include <sys/dsl_dataset.h>
32 #include <sys/dsl_bookmark.h>
33 #include <sys/dsl_destroy.h>
34 #include <sys/dmu_objset.h>
35 #include <sys/zfs_znode.h>
36 #include <sys/zfeature.h>
37 #include <sys/metaslab.h>
38 
39 #define	DST_AVG_BLKSHIFT 14
40 
41 typedef struct zcp_inherit_prop_arg {
42 	lua_State		*zipa_state;
43 	const char		*zipa_prop;
44 	dsl_props_set_arg_t	zipa_dpsa;
45 } zcp_inherit_prop_arg_t;
46 
47 typedef int (zcp_synctask_func_t)(lua_State *, boolean_t, nvlist_t *);
48 typedef struct zcp_synctask_info {
49 	const char *name;
50 	zcp_synctask_func_t *func;
51 	const zcp_arg_t pargs[4];
52 	const zcp_arg_t kwargs[2];
53 	zfs_space_check_t space_check;
54 	int blocks_modified;
55 } zcp_synctask_info_t;
56 
57 static void
zcp_synctask_cleanup(void * arg)58 zcp_synctask_cleanup(void *arg)
59 {
60 	fnvlist_free(arg);
61 }
62 
63 /*
64  * Generic synctask interface for channel program syncfuncs.
65  *
66  * To perform some action in syncing context, we'd generally call
67  * dsl_sync_task(), but since the Lua script is already running inside a
68  * synctask we need to leave out some actions (such as acquiring the config
69  * rwlock and performing space checks).
70  *
71  * If 'sync' is false, executes a dry run and returns the error code.
72  *
73  * If we are not running in syncing context and we are not doing a dry run
74  * (meaning we are running a zfs.sync function in open-context) then we
75  * return a Lua error.
76  *
77  * This function also handles common fatal error cases for channel program
78  * library functions. If a fatal error occurs, err_dsname will be the dataset
79  * name reported in error messages, if supplied.
80  */
81 static int
zcp_sync_task(lua_State * state,dsl_checkfunc_t * checkfunc,dsl_syncfunc_t * syncfunc,void * arg,boolean_t sync,const char * err_dsname)82 zcp_sync_task(lua_State *state, dsl_checkfunc_t *checkfunc,
83     dsl_syncfunc_t *syncfunc, void *arg, boolean_t sync, const char *err_dsname)
84 {
85 	int err;
86 	zcp_run_info_t *ri = zcp_run_info(state);
87 
88 	err = checkfunc(arg, ri->zri_tx);
89 	if (!sync)
90 		return (err);
91 
92 	if (!ri->zri_sync) {
93 		return (luaL_error(state, "running functions from the zfs.sync "
94 		    "submodule requires passing sync=TRUE to "
95 		    "lzc_channel_program() (i.e. do not specify the \"-n\" "
96 		    "command line argument)"));
97 	}
98 
99 	if (err == 0) {
100 		syncfunc(arg, ri->zri_tx);
101 	} else if (err == EIO) {
102 		if (err_dsname != NULL) {
103 			return (luaL_error(state,
104 			    "I/O error while accessing dataset '%s'",
105 			    err_dsname));
106 		} else {
107 			return (luaL_error(state,
108 			    "I/O error while accessing dataset."));
109 		}
110 	}
111 
112 	return (err);
113 }
114 
115 
116 static int zcp_synctask_destroy(lua_State *, boolean_t, nvlist_t *);
117 static const zcp_synctask_info_t zcp_synctask_destroy_info = {
118 	.name = "destroy",
119 	.func = zcp_synctask_destroy,
120 	.pargs = {
121 	    {.za_name = "filesystem | snapshot", .za_lua_type = LUA_TSTRING },
122 	    {NULL, 0}
123 	},
124 	.kwargs = {
125 	    {.za_name = "defer", .za_lua_type = LUA_TBOOLEAN },
126 	    {NULL, 0}
127 	},
128 	.space_check = ZFS_SPACE_CHECK_DESTROY,
129 	.blocks_modified = 0
130 };
131 
132 static int
zcp_synctask_destroy(lua_State * state,boolean_t sync,nvlist_t * err_details)133 zcp_synctask_destroy(lua_State *state, boolean_t sync, nvlist_t *err_details)
134 {
135 	(void) err_details;
136 	int err;
137 	const char *dsname = lua_tostring(state, 1);
138 
139 	boolean_t issnap = (strchr(dsname, '@') != NULL);
140 
141 	if (!issnap && !lua_isnil(state, 2)) {
142 		return (luaL_error(state,
143 		    "'deferred' kwarg only supported for snapshots: %s",
144 		    dsname));
145 	}
146 
147 	if (issnap) {
148 		dsl_destroy_snapshot_arg_t ddsa = { 0 };
149 		ddsa.ddsa_name = dsname;
150 		if (!lua_isnil(state, 2)) {
151 			ddsa.ddsa_defer = lua_toboolean(state, 2);
152 		} else {
153 			ddsa.ddsa_defer = B_FALSE;
154 		}
155 
156 		err = zcp_sync_task(state, dsl_destroy_snapshot_check,
157 		    dsl_destroy_snapshot_sync, &ddsa, sync, dsname);
158 	} else {
159 		dsl_destroy_head_arg_t ddha = { 0 };
160 		ddha.ddha_name = dsname;
161 
162 		err = zcp_sync_task(state, dsl_destroy_head_check,
163 		    dsl_destroy_head_sync, &ddha, sync, dsname);
164 	}
165 
166 	return (err);
167 }
168 
169 static int zcp_synctask_promote(lua_State *, boolean_t, nvlist_t *);
170 static const zcp_synctask_info_t zcp_synctask_promote_info = {
171 	.name = "promote",
172 	.func = zcp_synctask_promote,
173 	.pargs = {
174 	    {.za_name = "clone", .za_lua_type = LUA_TSTRING },
175 	    {NULL, 0}
176 	},
177 	.kwargs = {
178 	    {NULL, 0}
179 	},
180 	.space_check = ZFS_SPACE_CHECK_RESERVED,
181 	.blocks_modified = 3
182 };
183 
184 static int
zcp_synctask_promote(lua_State * state,boolean_t sync,nvlist_t * err_details)185 zcp_synctask_promote(lua_State *state, boolean_t sync, nvlist_t *err_details)
186 {
187 	int err;
188 	dsl_dataset_promote_arg_t ddpa = { 0 };
189 	const char *dsname = lua_tostring(state, 1);
190 	zcp_run_info_t *ri = zcp_run_info(state);
191 
192 	ddpa.ddpa_clonename = dsname;
193 	ddpa.err_ds = err_details;
194 	ddpa.cr = ri->zri_cred;
195 	ddpa.proc = ri->zri_proc;
196 
197 	/*
198 	 * If there was a snapshot name conflict, then err_ds will be filled
199 	 * with a list of conflicting snapshot names.
200 	 */
201 	err = zcp_sync_task(state, dsl_dataset_promote_check,
202 	    dsl_dataset_promote_sync, &ddpa, sync, dsname);
203 
204 	return (err);
205 }
206 
207 static int zcp_synctask_rollback(lua_State *, boolean_t, nvlist_t *err_details);
208 static const zcp_synctask_info_t zcp_synctask_rollback_info = {
209 	.name = "rollback",
210 	.func = zcp_synctask_rollback,
211 	.space_check = ZFS_SPACE_CHECK_RESERVED,
212 	.blocks_modified = 1,
213 	.pargs = {
214 	    {.za_name = "filesystem", .za_lua_type = LUA_TSTRING },
215 	    {0, 0}
216 	},
217 	.kwargs = {
218 	    {0, 0}
219 	}
220 };
221 
222 static int
zcp_synctask_rollback(lua_State * state,boolean_t sync,nvlist_t * err_details)223 zcp_synctask_rollback(lua_State *state, boolean_t sync, nvlist_t *err_details)
224 {
225 	int err;
226 	const char *dsname = lua_tostring(state, 1);
227 	dsl_dataset_rollback_arg_t ddra = { 0 };
228 
229 	ddra.ddra_fsname = dsname;
230 	ddra.ddra_result = err_details;
231 
232 	err = zcp_sync_task(state, dsl_dataset_rollback_check,
233 	    dsl_dataset_rollback_sync, &ddra, sync, dsname);
234 
235 	return (err);
236 }
237 
238 static int zcp_synctask_snapshot(lua_State *, boolean_t, nvlist_t *);
239 static const zcp_synctask_info_t zcp_synctask_snapshot_info = {
240 	.name = "snapshot",
241 	.func = zcp_synctask_snapshot,
242 	.pargs = {
243 	    {.za_name = "filesystem@snapname | volume@snapname",
244 	    .za_lua_type = LUA_TSTRING },
245 	    {NULL, 0}
246 	},
247 	.kwargs = {
248 	    {NULL, 0}
249 	},
250 	.space_check = ZFS_SPACE_CHECK_NORMAL,
251 	.blocks_modified = 3
252 };
253 
254 static int
zcp_synctask_snapshot(lua_State * state,boolean_t sync,nvlist_t * err_details)255 zcp_synctask_snapshot(lua_State *state, boolean_t sync, nvlist_t *err_details)
256 {
257 	(void) err_details;
258 	int err;
259 	dsl_dataset_snapshot_arg_t ddsa = { 0 };
260 	const char *dsname = lua_tostring(state, 1);
261 	zcp_run_info_t *ri = zcp_run_info(state);
262 
263 	/*
264 	 * On old pools, the ZIL must not be active when a snapshot is created,
265 	 * but we can't suspend the ZIL because we're already in syncing
266 	 * context.
267 	 */
268 	if (spa_version(ri->zri_pool->dp_spa) < SPA_VERSION_FAST_SNAP) {
269 		return (SET_ERROR(ENOTSUP));
270 	}
271 
272 	/*
273 	 * We only allow for a single snapshot rather than a list, so the
274 	 * error list output is unnecessary.
275 	 */
276 	ddsa.ddsa_errors = NULL;
277 	ddsa.ddsa_props = NULL;
278 	ddsa.ddsa_cr = ri->zri_cred;
279 	ddsa.ddsa_proc = ri->zri_proc;
280 	ddsa.ddsa_snaps = fnvlist_alloc();
281 	fnvlist_add_boolean(ddsa.ddsa_snaps, dsname);
282 
283 	zcp_cleanup_handler_t *zch = zcp_register_cleanup(state,
284 	    zcp_synctask_cleanup, ddsa.ddsa_snaps);
285 
286 	err = zcp_sync_task(state, dsl_dataset_snapshot_check,
287 	    dsl_dataset_snapshot_sync, &ddsa, sync, dsname);
288 
289 	if (err == 0) {
290 		/*
291 		 * We may need to create a new device minor node for this
292 		 * dataset (if it is a zvol and the "snapdev" property is set).
293 		 * Save it in the nvlist so that it can be processed in open
294 		 * context.
295 		 */
296 		fnvlist_add_boolean(ri->zri_new_zvols, dsname);
297 	}
298 
299 	zcp_deregister_cleanup(state, zch);
300 	fnvlist_free(ddsa.ddsa_snaps);
301 
302 	return (err);
303 }
304 
305 static int zcp_synctask_rename_snapshot(lua_State *, boolean_t, nvlist_t *);
306 static const zcp_synctask_info_t zcp_synctask_rename_snapshot_info = {
307 	.name = "rename_snapshot",
308 	.func = zcp_synctask_rename_snapshot,
309 	.pargs = {
310 	    {.za_name = "filesystem | volume", .za_lua_type = LUA_TSTRING },
311 	    {.za_name = "oldsnapname", .za_lua_type = LUA_TSTRING },
312 	    {.za_name = "newsnapname", .za_lua_type = LUA_TSTRING },
313 	    {NULL, 0}
314 	},
315 	.space_check = ZFS_SPACE_CHECK_RESERVED,
316 	.blocks_modified = 1
317 };
318 
319 static int
zcp_synctask_rename_snapshot(lua_State * state,boolean_t sync,nvlist_t * err_details)320 zcp_synctask_rename_snapshot(lua_State *state, boolean_t sync,
321     nvlist_t *err_details)
322 {
323 	(void) err_details;
324 	int err;
325 	const char *fsname = lua_tostring(state, 1);
326 	const char *oldsnapname = lua_tostring(state, 2);
327 	const char *newsnapname = lua_tostring(state, 3);
328 
329 	struct dsl_dataset_rename_snapshot_arg ddrsa = { 0 };
330 	ddrsa.ddrsa_fsname = fsname;
331 	ddrsa.ddrsa_oldsnapname = oldsnapname;
332 	ddrsa.ddrsa_newsnapname = newsnapname;
333 	ddrsa.ddrsa_recursive = B_FALSE;
334 
335 	err = zcp_sync_task(state, dsl_dataset_rename_snapshot_check,
336 	    dsl_dataset_rename_snapshot_sync, &ddrsa, sync, NULL);
337 
338 	return (err);
339 }
340 
341 static int zcp_synctask_inherit_prop(lua_State *, boolean_t,
342     nvlist_t *err_details);
343 static const zcp_synctask_info_t zcp_synctask_inherit_prop_info = {
344 	.name = "inherit",
345 	.func = zcp_synctask_inherit_prop,
346 	.space_check = ZFS_SPACE_CHECK_RESERVED,
347 	.blocks_modified = 2, /* 2 * numprops */
348 	.pargs = {
349 		{ .za_name = "dataset", .za_lua_type = LUA_TSTRING },
350 		{ .za_name = "property", .za_lua_type = LUA_TSTRING },
351 		{ NULL, 0 }
352 	},
353 	.kwargs = {
354 		{ NULL, 0 }
355 	},
356 };
357 
358 static int
zcp_synctask_inherit_prop_check(void * arg,dmu_tx_t * tx)359 zcp_synctask_inherit_prop_check(void *arg, dmu_tx_t *tx)
360 {
361 	zcp_inherit_prop_arg_t *args = arg;
362 	zfs_prop_t prop = zfs_name_to_prop(args->zipa_prop);
363 
364 	if (prop == ZPROP_USERPROP) {
365 		if (zfs_prop_user(args->zipa_prop))
366 			return (0);
367 
368 		return (EINVAL);
369 	}
370 
371 	if (zfs_prop_readonly(prop))
372 		return (EINVAL);
373 
374 	if (!zfs_prop_inheritable(prop))
375 		return (EINVAL);
376 
377 	return (dsl_props_set_check(&args->zipa_dpsa, tx));
378 }
379 
380 static void
zcp_synctask_inherit_prop_sync(void * arg,dmu_tx_t * tx)381 zcp_synctask_inherit_prop_sync(void *arg, dmu_tx_t *tx)
382 {
383 	zcp_inherit_prop_arg_t *args = arg;
384 	dsl_props_set_arg_t *dpsa = &args->zipa_dpsa;
385 
386 	dsl_props_set_sync(dpsa, tx);
387 }
388 
389 static int
zcp_synctask_inherit_prop(lua_State * state,boolean_t sync,nvlist_t * err_details)390 zcp_synctask_inherit_prop(lua_State *state, boolean_t sync,
391     nvlist_t *err_details)
392 {
393 	(void) err_details;
394 	int err;
395 	zcp_inherit_prop_arg_t zipa = { 0 };
396 	dsl_props_set_arg_t *dpsa = &zipa.zipa_dpsa;
397 
398 	const char *dsname = lua_tostring(state, 1);
399 	const char *prop = lua_tostring(state, 2);
400 
401 	zipa.zipa_state = state;
402 	zipa.zipa_prop = prop;
403 	dpsa->dpsa_dsname = dsname;
404 	dpsa->dpsa_source = ZPROP_SRC_INHERITED;
405 	dpsa->dpsa_props = fnvlist_alloc();
406 	fnvlist_add_boolean(dpsa->dpsa_props, prop);
407 
408 	zcp_cleanup_handler_t *zch = zcp_register_cleanup(state,
409 	    zcp_synctask_cleanup, dpsa->dpsa_props);
410 
411 	err = zcp_sync_task(state, zcp_synctask_inherit_prop_check,
412 	    zcp_synctask_inherit_prop_sync, &zipa, sync, dsname);
413 
414 	zcp_deregister_cleanup(state, zch);
415 	fnvlist_free(dpsa->dpsa_props);
416 
417 	return (err);
418 }
419 
420 static int zcp_synctask_bookmark(lua_State *, boolean_t, nvlist_t *);
421 static const zcp_synctask_info_t zcp_synctask_bookmark_info = {
422 	.name = "bookmark",
423 	.func = zcp_synctask_bookmark,
424 	.pargs = {
425 	    {.za_name = "snapshot | bookmark", .za_lua_type = LUA_TSTRING },
426 	    {.za_name = "bookmark", .za_lua_type = LUA_TSTRING },
427 	    {NULL, 0}
428 	},
429 	.kwargs = {
430 	    {NULL, 0}
431 	},
432 	.space_check = ZFS_SPACE_CHECK_NORMAL,
433 	.blocks_modified = 1,
434 };
435 
436 static int
zcp_synctask_bookmark(lua_State * state,boolean_t sync,nvlist_t * err_details)437 zcp_synctask_bookmark(lua_State *state, boolean_t sync, nvlist_t *err_details)
438 {
439 	(void) err_details;
440 	int err;
441 	const char *source = lua_tostring(state, 1);
442 	const char *new = lua_tostring(state, 2);
443 
444 	nvlist_t *bmarks = fnvlist_alloc();
445 	fnvlist_add_string(bmarks, new, source);
446 
447 	zcp_cleanup_handler_t *zch = zcp_register_cleanup(state,
448 	    zcp_synctask_cleanup, bmarks);
449 
450 	dsl_bookmark_create_arg_t dbca = {
451 		.dbca_bmarks = bmarks,
452 		.dbca_errors = NULL,
453 	};
454 	err = zcp_sync_task(state, dsl_bookmark_create_check,
455 	    dsl_bookmark_create_sync, &dbca, sync, source);
456 
457 	zcp_deregister_cleanup(state, zch);
458 	fnvlist_free(bmarks);
459 
460 	return (err);
461 }
462 
463 static int zcp_synctask_set_prop(lua_State *, boolean_t, nvlist_t *err_details);
464 static const zcp_synctask_info_t zcp_synctask_set_prop_info = {
465 	.name = "set_prop",
466 	.func = zcp_synctask_set_prop,
467 	.space_check = ZFS_SPACE_CHECK_RESERVED,
468 	.blocks_modified = 2,
469 	.pargs = {
470 		{ .za_name = "dataset", .za_lua_type = LUA_TSTRING },
471 		{ .za_name = "property", .za_lua_type =  LUA_TSTRING },
472 		{ .za_name = "value", .za_lua_type =  LUA_TSTRING },
473 		{ NULL, 0 }
474 	},
475 	.kwargs = {
476 		{ NULL, 0 }
477 	}
478 };
479 
480 static int
zcp_synctask_set_prop(lua_State * state,boolean_t sync,nvlist_t * err_details)481 zcp_synctask_set_prop(lua_State *state, boolean_t sync, nvlist_t *err_details)
482 {
483 	(void) err_details;
484 	int err;
485 	zcp_set_prop_arg_t args = { 0 };
486 
487 	const char *dsname = lua_tostring(state, 1);
488 	const char *prop = lua_tostring(state, 2);
489 	const char *val = lua_tostring(state, 3);
490 
491 	args.state = state;
492 	args.dsname = dsname;
493 	args.prop = prop;
494 	args.val = val;
495 
496 	err = zcp_sync_task(state, zcp_set_prop_check, zcp_set_prop_sync,
497 	    &args, sync, dsname);
498 
499 	return (err);
500 }
501 
502 static int
zcp_synctask_wrapper(lua_State * state)503 zcp_synctask_wrapper(lua_State *state)
504 {
505 	int err;
506 	zcp_cleanup_handler_t *zch;
507 	int num_ret = 1;
508 	nvlist_t *err_details = fnvlist_alloc();
509 
510 	/*
511 	 * Make sure err_details is properly freed, even if a fatal error is
512 	 * thrown during the synctask.
513 	 */
514 	zch = zcp_register_cleanup(state, zcp_synctask_cleanup, err_details);
515 
516 	zcp_synctask_info_t *info = lua_touserdata(state, lua_upvalueindex(1));
517 	boolean_t sync = lua_toboolean(state, lua_upvalueindex(2));
518 
519 	zcp_run_info_t *ri = zcp_run_info(state);
520 	dsl_pool_t *dp = ri->zri_pool;
521 
522 	/* MOS space is triple-dittoed, so we multiply by 3. */
523 	uint64_t funcspace =
524 	    ((uint64_t)info->blocks_modified << DST_AVG_BLKSHIFT) * 3;
525 
526 	zcp_parse_args(state, info->name, info->pargs, info->kwargs);
527 
528 	err = 0;
529 	if (info->space_check != ZFS_SPACE_CHECK_NONE) {
530 		uint64_t quota = dsl_pool_unreserved_space(dp,
531 		    info->space_check);
532 		uint64_t used = dsl_dir_phys(dp->dp_root_dir)->dd_used_bytes +
533 		    ri->zri_space_used;
534 
535 		if (used + funcspace > quota) {
536 			err = SET_ERROR(ENOSPC);
537 		}
538 	}
539 
540 	if (err == 0) {
541 		err = info->func(state, sync, err_details);
542 	}
543 
544 	if (err == 0) {
545 		ri->zri_space_used += funcspace;
546 	}
547 
548 	lua_pushnumber(state, (lua_Number)err);
549 	if (fnvlist_num_pairs(err_details) > 0) {
550 		(void) zcp_nvlist_to_lua(state, err_details, NULL, 0);
551 		num_ret++;
552 	}
553 
554 	zcp_deregister_cleanup(state, zch);
555 	fnvlist_free(err_details);
556 
557 	return (num_ret);
558 }
559 
560 int
zcp_load_synctask_lib(lua_State * state,boolean_t sync)561 zcp_load_synctask_lib(lua_State *state, boolean_t sync)
562 {
563 	const zcp_synctask_info_t *zcp_synctask_funcs[] = {
564 		&zcp_synctask_destroy_info,
565 		&zcp_synctask_promote_info,
566 		&zcp_synctask_rollback_info,
567 		&zcp_synctask_snapshot_info,
568 		&zcp_synctask_rename_snapshot_info,
569 		&zcp_synctask_inherit_prop_info,
570 		&zcp_synctask_bookmark_info,
571 		&zcp_synctask_set_prop_info,
572 		NULL
573 	};
574 
575 	lua_newtable(state);
576 
577 	for (int i = 0; zcp_synctask_funcs[i] != NULL; i++) {
578 		const zcp_synctask_info_t *info = zcp_synctask_funcs[i];
579 		lua_pushlightuserdata(state, (void *)(uintptr_t)info);
580 		lua_pushboolean(state, sync);
581 		lua_pushcclosure(state, &zcp_synctask_wrapper, 2);
582 		lua_setfield(state, -2, info->name);
583 	}
584 
585 	return (1);
586 }
587