xref: /illumos-gate/usr/src/uts/common/fs/zfs/zcp_get.c (revision 9f755eec1bb2532196698ec9bd1aaeb85dc903c4)
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  */
19 
20 #include "lua.h"
21 #include "lualib.h"
22 #include "lauxlib.h"
23 
24 #include <zfs_prop.h>
25 
26 #include <sys/dsl_prop.h>
27 #include <sys/dsl_synctask.h>
28 #include <sys/dsl_dataset.h>
29 #include <sys/dsl_dir.h>
30 #include <sys/dmu_objset.h>
31 #include <sys/mntent.h>
32 #include <sys/sunddi.h>
33 #include <sys/zap.h>
34 #include <sys/zcp.h>
35 #include <sys/zcp_iter.h>
36 #include <sys/zcp_global.h>
37 #include <sys/zfs_ioctl.h>
38 #include <sys/zfs_znode.h>
39 #include <sys/zvol.h>
40 
41 #ifdef _KERNEL
42 #include <sys/zfs_vfsops.h>
43 #endif
44 
45 static int
46 get_objset_type(dsl_dataset_t *ds, zfs_type_t *type)
47 {
48 	int error;
49 	objset_t *os;
50 	error = dmu_objset_from_ds(ds, &os);
51 	if (error != 0)
52 		return (error);
53 	if (ds->ds_is_snapshot) {
54 		*type = ZFS_TYPE_SNAPSHOT;
55 	} else {
56 		switch (os->os_phys->os_type) {
57 		case DMU_OST_ZFS:
58 			*type = ZFS_TYPE_FILESYSTEM;
59 			break;
60 		case DMU_OST_ZVOL:
61 			*type = ZFS_TYPE_VOLUME;
62 			break;
63 		default:
64 			return (EINVAL);
65 		}
66 	}
67 	return (0);
68 }
69 
70 /*
71  * Returns the string name of ds's type in str (a buffer which should be
72  * at least 12 bytes long).
73  */
74 static int
75 get_objset_type_name(dsl_dataset_t *ds, char *str)
76 {
77 	int error;
78 	zfs_type_t type;
79 	error = get_objset_type(ds, &type);
80 	if (error != 0)
81 		return (error);
82 	switch (type) {
83 	case ZFS_TYPE_SNAPSHOT:
84 		(void) strcpy(str, "snapshot");
85 		break;
86 	case ZFS_TYPE_FILESYSTEM:
87 		(void) strcpy(str, "filesystem");
88 		break;
89 	case ZFS_TYPE_VOLUME:
90 		(void) strcpy(str, "volume");
91 		break;
92 	default:
93 		return (EINVAL);
94 	}
95 	return (0);
96 }
97 
98 /*
99  * Determines the source of a property given its setpoint and
100  * property type. It pushes the source to the lua stack.
101  */
102 static void
103 get_prop_src(lua_State *state, const char *setpoint, zfs_prop_t prop)
104 {
105 	if (zfs_prop_readonly(prop) || (prop == ZFS_PROP_VERSION)) {
106 		lua_pushnil(state);
107 	} else {
108 		const char *src;
109 		if (strcmp("", setpoint) == 0) {
110 			src = "default";
111 		} else {
112 			src = setpoint;
113 		}
114 		(void) lua_pushstring(state, src);
115 	}
116 }
117 
118 /*
119  * Given an error encountered while getting properties, either longjmp's for
120  * a fatal error or pushes nothing to the stack for a non fatal one.
121  */
122 static int
123 zcp_handle_error(lua_State *state, const char *dataset_name,
124     const char *property_name, int error)
125 {
126 	ASSERT3S(error, !=, 0);
127 	if (error == ENOENT) {
128 		return (0);
129 	} else if (error == EINVAL) {
130 		return (luaL_error(state,
131 		    "property '%s' is not a valid property on dataset '%s'",
132 		    property_name, dataset_name));
133 	} else if (error == EIO) {
134 		return (luaL_error(state,
135 		    "I/O error while retrieving property '%s' on dataset '%s'",
136 		    property_name, dataset_name));
137 	} else {
138 		return (luaL_error(state, "unexpected error %d while "
139 		    "retrieving property '%s' on dataset '%s'",
140 		    error, property_name, dataset_name));
141 	}
142 }
143 
144 /*
145  * Look up a user defined property in the zap object. If it exists, push it
146  * and the setpoint onto the stack, otherwise don't push anything.
147  */
148 static int
149 zcp_get_user_prop(lua_State *state, dsl_pool_t *dp, const char *dataset_name,
150     const char *property_name)
151 {
152 	int error;
153 	char *buf;
154 	char setpoint[ZFS_MAX_DATASET_NAME_LEN];
155 	/*
156 	 * zcp_dataset_hold will either successfully return the requested
157 	 * dataset or throw a lua error and longjmp out of the zfs.get_prop call
158 	 * without returning.
159 	 */
160 	dsl_dataset_t *ds = zcp_dataset_hold(state, dp, dataset_name, FTAG);
161 	if (ds == NULL)
162 		return (1); /* not reached; zcp_dataset_hold() longjmp'd */
163 
164 	buf = kmem_alloc(ZAP_MAXVALUELEN, KM_SLEEP);
165 	error = dsl_prop_get_ds(ds, property_name, 1, ZAP_MAXVALUELEN,
166 	    buf, setpoint);
167 	dsl_dataset_rele(ds, FTAG);
168 
169 	if (error != 0) {
170 		kmem_free(buf, ZAP_MAXVALUELEN);
171 		return (zcp_handle_error(state, dataset_name, property_name,
172 		    error));
173 	}
174 	(void) lua_pushstring(state, buf);
175 	(void) lua_pushstring(state, setpoint);
176 	kmem_free(buf, ZAP_MAXVALUELEN);
177 	return (2);
178 }
179 
180 /*
181  * Check if the property we're looking for is stored in the ds_dir. If so,
182  * return it in the 'val' argument. Return 0 on success and ENOENT and if
183  * the property is not present.
184  */
185 static int
186 get_dsl_dir_prop(dsl_dataset_t *ds, zfs_prop_t zfs_prop,
187     uint64_t *val)
188 {
189 	dsl_dir_t *dd = ds->ds_dir;
190 	mutex_enter(&dd->dd_lock);
191 	switch (zfs_prop) {
192 	case ZFS_PROP_USEDSNAP:
193 		*val = dsl_dir_get_usedsnap(dd);
194 		break;
195 	case ZFS_PROP_USEDCHILD:
196 		*val = dsl_dir_get_usedchild(dd);
197 		break;
198 	case ZFS_PROP_USEDDS:
199 		*val = dsl_dir_get_usedds(dd);
200 		break;
201 	case ZFS_PROP_USEDREFRESERV:
202 		*val = dsl_dir_get_usedrefreserv(dd);
203 		break;
204 	case ZFS_PROP_LOGICALUSED:
205 		*val = dsl_dir_get_logicalused(dd);
206 		break;
207 	default:
208 		mutex_exit(&dd->dd_lock);
209 		return (ENOENT);
210 	}
211 	mutex_exit(&dd->dd_lock);
212 	return (0);
213 }
214 
215 /*
216  * Takes a dataset, a property, a value and that value's setpoint as
217  * found in the ZAP. Checks if the property has been changed in the vfs.
218  * If so, val and setpoint will be overwritten with updated content.
219  * Otherwise, they are left unchanged.
220  */
221 static int
222 get_temporary_prop(dsl_dataset_t *ds, zfs_prop_t zfs_prop, uint64_t *val,
223     char *setpoint)
224 {
225 #ifndef _KERNEL
226 	return (0);
227 #else
228 	int error;
229 	zfsvfs_t *zfvp;
230 	vfs_t *vfsp;
231 	objset_t *os;
232 	uint64_t tmp = *val;
233 
234 	error = dmu_objset_from_ds(ds, &os);
235 	if (error != 0)
236 		return (error);
237 
238 	error = getzfsvfs_impl(os, &zfvp);
239 	if (error != 0)
240 		return (error);
241 
242 	vfsp = zfvp->z_vfs;
243 
244 	switch (zfs_prop) {
245 	case ZFS_PROP_ATIME:
246 		if (vfs_optionisset(vfsp, MNTOPT_NOATIME, NULL))
247 			tmp = 0;
248 		if (vfs_optionisset(vfsp, MNTOPT_ATIME, NULL))
249 			tmp = 1;
250 		break;
251 	case ZFS_PROP_DEVICES:
252 		if (vfs_optionisset(vfsp, MNTOPT_NODEVICES, NULL))
253 			tmp = 0;
254 		if (vfs_optionisset(vfsp, MNTOPT_DEVICES, NULL))
255 			tmp = 1;
256 		break;
257 	case ZFS_PROP_EXEC:
258 		if (vfs_optionisset(vfsp, MNTOPT_NOEXEC, NULL))
259 			tmp = 0;
260 		if (vfs_optionisset(vfsp, MNTOPT_EXEC, NULL))
261 			tmp = 1;
262 		break;
263 	case ZFS_PROP_SETUID:
264 		if (vfs_optionisset(vfsp, MNTOPT_NOSETUID, NULL))
265 			tmp = 0;
266 		if (vfs_optionisset(vfsp, MNTOPT_SETUID, NULL))
267 			tmp = 1;
268 		break;
269 	case ZFS_PROP_READONLY:
270 		if (vfs_optionisset(vfsp, MNTOPT_RW, NULL))
271 			tmp = 0;
272 		if (vfs_optionisset(vfsp, MNTOPT_RO, NULL))
273 			tmp = 1;
274 		break;
275 	case ZFS_PROP_XATTR:
276 		if (vfs_optionisset(vfsp, MNTOPT_NOXATTR, NULL))
277 			tmp = 0;
278 		if (vfs_optionisset(vfsp, MNTOPT_XATTR, NULL))
279 			tmp = 1;
280 		break;
281 	case ZFS_PROP_NBMAND:
282 		if (vfs_optionisset(vfsp, MNTOPT_NONBMAND, NULL))
283 			tmp = 0;
284 		if (vfs_optionisset(vfsp, MNTOPT_NBMAND, NULL))
285 			tmp = 1;
286 		break;
287 	default:
288 		VFS_RELE(vfsp);
289 		return (ENOENT);
290 	}
291 
292 	VFS_RELE(vfsp);
293 	if (tmp != *val) {
294 		(void) strcpy(setpoint, "temporary");
295 		*val = tmp;
296 	}
297 	return (0);
298 #endif
299 }
300 
301 /*
302  * Check if the property we're looking for is stored at the dsl_dataset or
303  * dsl_dir level. If so, push the property value and source onto the lua stack
304  * and return 0. If it is not present or a failure occurs in lookup, return a
305  * non-zero error value.
306  */
307 static int
308 get_special_prop(lua_State *state, dsl_dataset_t *ds, const char *dsname,
309     zfs_prop_t zfs_prop)
310 {
311 	int error = 0;
312 	objset_t *os;
313 	uint64_t numval;
314 	char *strval = kmem_alloc(ZAP_MAXVALUELEN, KM_SLEEP);
315 	char setpoint[ZFS_MAX_DATASET_NAME_LEN] =
316 	    "Internal error - setpoint not determined";
317 	zfs_type_t ds_type;
318 	zprop_type_t prop_type = zfs_prop_get_type(zfs_prop);
319 	(void) get_objset_type(ds, &ds_type);
320 
321 	switch (zfs_prop) {
322 	case ZFS_PROP_REFRATIO:
323 		numval = dsl_get_refratio(ds);
324 		break;
325 	case ZFS_PROP_USED:
326 		numval = dsl_get_used(ds);
327 		break;
328 	case ZFS_PROP_CLONES: {
329 		nvlist_t *clones = fnvlist_alloc();
330 		error = get_clones_stat_impl(ds, clones);
331 		if (error == 0) {
332 			/* push list to lua stack */
333 			VERIFY0(zcp_nvlist_to_lua(state, clones, NULL, 0));
334 			/* source */
335 			(void) lua_pushnil(state);
336 		}
337 		nvlist_free(clones);
338 		kmem_free(strval, ZAP_MAXVALUELEN);
339 		return (error);
340 	}
341 	case ZFS_PROP_COMPRESSRATIO:
342 		numval = dsl_get_compressratio(ds);
343 		break;
344 	case ZFS_PROP_CREATION:
345 		numval = dsl_get_creation(ds);
346 		break;
347 	case ZFS_PROP_REFERENCED:
348 		numval = dsl_get_referenced(ds);
349 		break;
350 	case ZFS_PROP_AVAILABLE:
351 		numval = dsl_get_available(ds);
352 		break;
353 	case ZFS_PROP_LOGICALREFERENCED:
354 		numval = dsl_get_logicalreferenced(ds);
355 		break;
356 	case ZFS_PROP_CREATETXG:
357 		numval = dsl_get_creationtxg(ds);
358 		break;
359 	case ZFS_PROP_GUID:
360 		numval = dsl_get_guid(ds);
361 		break;
362 	case ZFS_PROP_UNIQUE:
363 		numval = dsl_get_unique(ds);
364 		break;
365 	case ZFS_PROP_OBJSETID:
366 		numval = dsl_get_objsetid(ds);
367 		break;
368 	case ZFS_PROP_ORIGIN:
369 		dsl_dir_get_origin(ds->ds_dir, strval);
370 		break;
371 	case ZFS_PROP_USERACCOUNTING:
372 		error = dmu_objset_from_ds(ds, &os);
373 		if (error == 0)
374 			numval = dmu_objset_userspace_present(os);
375 		break;
376 	case ZFS_PROP_WRITTEN:
377 		error = dsl_get_written(ds, &numval);
378 		break;
379 	case ZFS_PROP_TYPE:
380 		error = get_objset_type_name(ds, strval);
381 		break;
382 	case ZFS_PROP_PREV_SNAP:
383 		error = dsl_get_prev_snap(ds, strval);
384 		break;
385 	case ZFS_PROP_NAME:
386 		dsl_dataset_name(ds, strval);
387 		break;
388 	case ZFS_PROP_MOUNTPOINT:
389 		error = dsl_get_mountpoint(ds, dsname, strval, setpoint);
390 		break;
391 	case ZFS_PROP_VERSION:
392 		/* should be a snapshot or filesystem */
393 		ASSERT(ds_type != ZFS_TYPE_VOLUME);
394 		error = dmu_objset_from_ds(ds, &os);
395 		/* look in the master node for the version */
396 		if (error == 0) {
397 			error = zap_lookup(os, MASTER_NODE_OBJ, ZPL_VERSION_STR,
398 			    sizeof (numval), 1, &numval);
399 		}
400 		break;
401 	case ZFS_PROP_DEFER_DESTROY:
402 		numval = dsl_get_defer_destroy(ds);
403 		break;
404 	case ZFS_PROP_USERREFS:
405 		numval = dsl_get_userrefs(ds);
406 		break;
407 	case ZFS_PROP_FILESYSTEM_COUNT:
408 		error = dsl_dir_get_filesystem_count(ds->ds_dir, &numval);
409 		(void) strcpy(setpoint, "");
410 		break;
411 	case ZFS_PROP_SNAPSHOT_COUNT:
412 		error = dsl_dir_get_snapshot_count(ds->ds_dir, &numval);
413 		(void) strcpy(setpoint, "");
414 		break;
415 	case ZFS_PROP_REMAPTXG:
416 		error = dsl_dir_get_remaptxg(ds->ds_dir, &numval);
417 		break;
418 	case ZFS_PROP_NUMCLONES:
419 		numval = dsl_get_numclones(ds);
420 		break;
421 	case ZFS_PROP_INCONSISTENT:
422 		numval = dsl_get_inconsistent(ds);
423 		break;
424 	case ZFS_PROP_IVSET_GUID:
425 		if (dsl_dataset_is_zapified(ds)) {
426 			error = zap_lookup(ds->ds_dir->dd_pool->dp_meta_objset,
427 			    ds->ds_object, DS_FIELD_IVSET_GUID,
428 			    sizeof (numval), 1, &numval);
429 		} else {
430 			error = ENOENT;
431 		}
432 		break;
433 	case ZFS_PROP_RECEIVE_RESUME_TOKEN: {
434 		char *token = get_receive_resume_stats_impl(ds);
435 		VERIFY3U(strlcpy(strval, token, ZAP_MAXVALUELEN), <,
436 		    ZAP_MAXVALUELEN);
437 		strfree(token);
438 		if (strcmp(strval, "") == 0) {
439 			token = get_child_receive_stats(ds);
440 			VERIFY3U(strlcpy(strval, token, ZAP_MAXVALUELEN), <,
441 			    ZAP_MAXVALUELEN);
442 			strfree(token);
443 			if (strcmp(strval, "") == 0)
444 				error = ENOENT;
445 		}
446 		break;
447 	}
448 	case ZFS_PROP_VOLSIZE:
449 		ASSERT(ds_type == ZFS_TYPE_VOLUME ||
450 		    ds_type == ZFS_TYPE_SNAPSHOT);
451 		error = dmu_objset_from_ds(ds, &os);
452 		if (error == 0) {
453 			error = zap_lookup(os, ZVOL_ZAP_OBJ, "size",
454 			    sizeof (numval), 1, &numval);
455 		}
456 		if (error == 0)
457 			(void) strlcpy(setpoint, dsname,
458 			    ZFS_MAX_DATASET_NAME_LEN);
459 
460 		break;
461 	case ZFS_PROP_VOLBLOCKSIZE: {
462 		ASSERT(ds_type == ZFS_TYPE_VOLUME);
463 		dmu_object_info_t doi;
464 		error = dmu_objset_from_ds(ds, &os);
465 		if (error == 0) {
466 			error = dmu_object_info(os, ZVOL_OBJ, &doi);
467 			if (error == 0)
468 				numval = doi.doi_data_block_size;
469 		}
470 		break;
471 	}
472 	default:
473 		/* Did not match these props, check in the dsl_dir */
474 		error = get_dsl_dir_prop(ds, zfs_prop, &numval);
475 	}
476 	if (error != 0) {
477 		kmem_free(strval, ZAP_MAXVALUELEN);
478 		return (error);
479 	}
480 
481 	switch (prop_type) {
482 	case PROP_TYPE_NUMBER: {
483 		(void) lua_pushnumber(state, numval);
484 		break;
485 	}
486 	case PROP_TYPE_STRING: {
487 		(void) lua_pushstring(state, strval);
488 		break;
489 	}
490 	case PROP_TYPE_INDEX: {
491 		const char *propval;
492 		error = zfs_prop_index_to_string(zfs_prop, numval, &propval);
493 		if (error != 0) {
494 			kmem_free(strval, ZAP_MAXVALUELEN);
495 			return (error);
496 		}
497 		(void) lua_pushstring(state, propval);
498 		break;
499 	}
500 	}
501 	kmem_free(strval, ZAP_MAXVALUELEN);
502 
503 	/* Push the source to the stack */
504 	get_prop_src(state, setpoint, zfs_prop);
505 	return (0);
506 }
507 
508 /*
509  * Look up a property and its source in the zap object. If the value is
510  * present and successfully retrieved, push the value and source on the
511  * lua stack and return 0. On failure, return a non-zero error value.
512  */
513 static int
514 get_zap_prop(lua_State *state, dsl_dataset_t *ds, zfs_prop_t zfs_prop)
515 {
516 	int error = 0;
517 	char setpoint[ZFS_MAX_DATASET_NAME_LEN];
518 	char *strval = kmem_alloc(ZAP_MAXVALUELEN, KM_SLEEP);
519 	uint64_t numval;
520 	const char *prop_name = zfs_prop_to_name(zfs_prop);
521 	zprop_type_t prop_type = zfs_prop_get_type(zfs_prop);
522 
523 	if (prop_type == PROP_TYPE_STRING) {
524 		/* Push value to lua stack */
525 		error = dsl_prop_get_ds(ds, prop_name, 1,
526 		    ZAP_MAXVALUELEN, strval, setpoint);
527 		if (error == 0)
528 			(void) lua_pushstring(state, strval);
529 	} else {
530 		error = dsl_prop_get_ds(ds, prop_name, sizeof (numval),
531 		    1, &numval, setpoint);
532 
533 		/* Fill in temorary value for prop, if applicable */
534 		(void) get_temporary_prop(ds, zfs_prop, &numval, setpoint);
535 
536 		/* Push value to lua stack */
537 		if (prop_type == PROP_TYPE_INDEX) {
538 			const char *propval;
539 			error = zfs_prop_index_to_string(zfs_prop, numval,
540 			    &propval);
541 			if (error == 0)
542 				(void) lua_pushstring(state, propval);
543 		} else {
544 			if (error == 0)
545 				(void) lua_pushnumber(state, numval);
546 		}
547 	}
548 	kmem_free(strval, ZAP_MAXVALUELEN);
549 	if (error == 0)
550 		get_prop_src(state, setpoint, zfs_prop);
551 	return (error);
552 }
553 
554 /*
555  * Determine whether property is valid for a given dataset
556  */
557 boolean_t
558 prop_valid_for_ds(dsl_dataset_t *ds, zfs_prop_t zfs_prop)
559 {
560 	int error;
561 	zfs_type_t zfs_type;
562 
563 	/* properties not supported */
564 	if ((zfs_prop == ZFS_PROP_ISCSIOPTIONS) ||
565 	    (zfs_prop == ZFS_PROP_MOUNTED))
566 		return (B_FALSE);
567 
568 	/* if we want the origin prop, ds must be a clone */
569 	if ((zfs_prop == ZFS_PROP_ORIGIN) && (!dsl_dir_is_clone(ds->ds_dir)))
570 		return (B_FALSE);
571 
572 	error = get_objset_type(ds, &zfs_type);
573 	if (error != 0)
574 		return (B_FALSE);
575 	return (zfs_prop_valid_for_type(zfs_prop, zfs_type, B_FALSE));
576 }
577 
578 /*
579  * Look up a given dataset property. On success return 2, the number of
580  * values pushed to the lua stack (property value and source). On a fatal
581  * error, longjmp. On a non fatal error push nothing.
582  */
583 static int
584 zcp_get_system_prop(lua_State *state, dsl_pool_t *dp, const char *dataset_name,
585     zfs_prop_t zfs_prop)
586 {
587 	int error;
588 	/*
589 	 * zcp_dataset_hold will either successfully return the requested
590 	 * dataset or throw a lua error and longjmp out of the zfs.get_prop call
591 	 * without returning.
592 	 */
593 	dsl_dataset_t *ds = zcp_dataset_hold(state, dp, dataset_name, FTAG);
594 	if (ds == NULL)
595 		return (1); /* not reached; zcp_dataset_hold() longjmp'd */
596 
597 	/* Check that the property is valid for the given dataset */
598 	const char *prop_name = zfs_prop_to_name(zfs_prop);
599 	if (!prop_valid_for_ds(ds, zfs_prop)) {
600 		dsl_dataset_rele(ds, FTAG);
601 		return (0);
602 	}
603 
604 	/* Check if the property can be accessed directly */
605 	error = get_special_prop(state, ds, dataset_name, zfs_prop);
606 	if (error == 0) {
607 		dsl_dataset_rele(ds, FTAG);
608 		/* The value and source have been pushed by get_special_prop */
609 		return (2);
610 	}
611 	if (error != ENOENT) {
612 		dsl_dataset_rele(ds, FTAG);
613 		return (zcp_handle_error(state, dataset_name,
614 		    prop_name, error));
615 	}
616 
617 	/* If we were unable to find it, look in the zap object */
618 	error = get_zap_prop(state, ds, zfs_prop);
619 	dsl_dataset_rele(ds, FTAG);
620 	if (error != 0) {
621 		return (zcp_handle_error(state, dataset_name,
622 		    prop_name, error));
623 	}
624 	/* The value and source have been pushed by get_zap_prop */
625 	return (2);
626 }
627 
628 static zfs_userquota_prop_t
629 get_userquota_prop(const char *prop_name)
630 {
631 	zfs_userquota_prop_t type;
632 	/* Figure out the property type ({user|group}{quota|used}) */
633 	for (type = 0; type < ZFS_NUM_USERQUOTA_PROPS; type++) {
634 		if (strncmp(prop_name, zfs_userquota_prop_prefixes[type],
635 		    strlen(zfs_userquota_prop_prefixes[type])) == 0)
636 			break;
637 	}
638 	return (type);
639 }
640 
641 #ifdef _KERNEL
642 /*
643  * Given the name of a zfs_userquota_prop, this function determines the
644  * prop type as well as the numeric group/user ids based on the string
645  * following the '@' in the property name. On success, returns 0. On failure,
646  * returns a non-zero error.
647  * 'domain' must be free'd by caller using strfree()
648  */
649 static int
650 parse_userquota_prop(const char *prop_name, zfs_userquota_prop_t *type,
651     char **domain, uint64_t *rid)
652 {
653 	char *cp, *end, *domain_val;
654 
655 	*type = get_userquota_prop(prop_name);
656 	if (*type >= ZFS_NUM_USERQUOTA_PROPS)
657 		return (EINVAL);
658 
659 	*rid = 0;
660 	cp = strchr(prop_name, '@') + 1;
661 	if (strncmp(cp, "S-1-", 4) == 0) {
662 		/*
663 		 * It's a numeric SID (eg "S-1-234-567-89") and we want to
664 		 * seperate the domain id and the rid
665 		 */
666 		int domain_len = strrchr(cp, '-') - cp;
667 		domain_val = kmem_alloc(domain_len + 1, KM_SLEEP);
668 		(void) strncpy(domain_val, cp, domain_len);
669 		domain_val[domain_len] = '\0';
670 		cp += domain_len + 1;
671 
672 		(void) ddi_strtoll(cp, &end, 10, (longlong_t *)rid);
673 		if (*end != '\0') {
674 			strfree(domain_val);
675 			return (EINVAL);
676 		}
677 	} else {
678 		/* It's only a user/group ID (eg "12345"), just get the rid */
679 		domain_val = NULL;
680 		(void) ddi_strtoll(cp, &end, 10, (longlong_t *)rid);
681 		if (*end != '\0')
682 			return (EINVAL);
683 	}
684 	*domain = domain_val;
685 	return (0);
686 }
687 
688 /*
689  * Look up {user|group}{quota|used} property for given dataset. On success
690  * push the value (quota or used amount) and the setpoint. On failure, push
691  * a lua error.
692  */
693 static int
694 zcp_get_userquota_prop(lua_State *state, dsl_pool_t *dp,
695     const char *dataset_name, const char *prop_name)
696 {
697 	zfsvfs_t *zfvp;
698 	zfsvfs_t *zfsvfs;
699 	int error;
700 	zfs_userquota_prop_t type;
701 	char *domain;
702 	uint64_t rid, value;
703 	objset_t *os;
704 
705 	dsl_dataset_t *ds = zcp_dataset_hold(state, dp, dataset_name, FTAG);
706 	if (ds == NULL)
707 		return (1); /* not reached; zcp_dataset_hold() longjmp'd */
708 
709 	error = parse_userquota_prop(prop_name, &type, &domain, &rid);
710 	if (error == 0) {
711 		error = dmu_objset_from_ds(ds, &os);
712 		if (error == 0) {
713 			zfsvfs = kmem_zalloc(sizeof (zfsvfs_t), KM_SLEEP);
714 			error = zfsvfs_create_impl(&zfvp, zfsvfs, os);
715 			if (error == 0) {
716 				error = zfs_userspace_one(zfvp, type, domain,
717 				    rid, &value);
718 				zfsvfs_free(zfvp);
719 			}
720 		}
721 		if (domain != NULL)
722 			strfree(domain);
723 	}
724 	dsl_dataset_rele(ds, FTAG);
725 
726 	if ((value == 0) && ((type == ZFS_PROP_USERQUOTA) ||
727 	    (type == ZFS_PROP_GROUPQUOTA)))
728 		error = ENOENT;
729 	if (error != 0) {
730 		return (zcp_handle_error(state, dataset_name,
731 		    prop_name, error));
732 	}
733 
734 	(void) lua_pushnumber(state, value);
735 	(void) lua_pushstring(state, dataset_name);
736 	return (2);
737 }
738 #endif
739 
740 /*
741  * Determines the name of the snapshot referenced in the written property
742  * name. Returns snapshot name in snap_name, a buffer that must be at least
743  * as large as ZFS_MAX_DATASET_NAME_LEN
744  */
745 static void
746 parse_written_prop(const char *dataset_name, const char *prop_name,
747     char *snap_name)
748 {
749 	ASSERT(zfs_prop_written(prop_name));
750 	const char *name = prop_name + ZFS_WRITTEN_PROP_PREFIX_LEN;
751 	if (strchr(name, '@') == NULL) {
752 		(void) sprintf(snap_name, "%s@%s", dataset_name, name);
753 	} else {
754 		(void) strcpy(snap_name, name);
755 	}
756 }
757 
758 /*
759  * Look up written@ property for given dataset. On success
760  * push the value and the setpoint. If error is fatal, we will
761  * longjmp, otherwise push nothing.
762  */
763 static int
764 zcp_get_written_prop(lua_State *state, dsl_pool_t *dp,
765     const char *dataset_name, const char *prop_name)
766 {
767 	char snap_name[ZFS_MAX_DATASET_NAME_LEN];
768 	uint64_t used, comp, uncomp;
769 	dsl_dataset_t *old;
770 	int error = 0;
771 
772 	parse_written_prop(dataset_name, prop_name, snap_name);
773 	dsl_dataset_t *new = zcp_dataset_hold(state, dp, dataset_name, FTAG);
774 	if (new == NULL)
775 		return (1); /* not reached; zcp_dataset_hold() longjmp'd */
776 
777 	error = dsl_dataset_hold(dp, snap_name, FTAG, &old);
778 	if (error != 0) {
779 		dsl_dataset_rele(new, FTAG);
780 		return (zcp_dataset_hold_error(state, dp, snap_name,
781 		    error));
782 	}
783 	error = dsl_dataset_space_written(old, new,
784 	    &used, &comp, &uncomp);
785 
786 	dsl_dataset_rele(old, FTAG);
787 	dsl_dataset_rele(new, FTAG);
788 
789 	if (error != 0) {
790 		return (zcp_handle_error(state, dataset_name,
791 		    snap_name, error));
792 	}
793 	(void) lua_pushnumber(state, used);
794 	(void) lua_pushstring(state, dataset_name);
795 	return (2);
796 }
797 
798 static int zcp_get_prop(lua_State *state);
799 static zcp_lib_info_t zcp_get_prop_info = {
800 	.name = "get_prop",
801 	.func = zcp_get_prop,
802 	.pargs = {
803 	    { .za_name = "dataset", .za_lua_type = LUA_TSTRING},
804 	    { .za_name = "property", .za_lua_type =  LUA_TSTRING},
805 	    {NULL, 0}
806 	},
807 	.kwargs = {
808 	    {NULL, 0}
809 	}
810 };
811 
812 static int
813 zcp_get_prop(lua_State *state)
814 {
815 	const char *dataset_name;
816 	const char *property_name;
817 	dsl_pool_t *dp = zcp_run_info(state)->zri_pool;
818 	zcp_lib_info_t *libinfo = &zcp_get_prop_info;
819 
820 	zcp_parse_args(state, libinfo->name, libinfo->pargs, libinfo->kwargs);
821 
822 	dataset_name = lua_tostring(state, 1);
823 	property_name = lua_tostring(state, 2);
824 
825 	/* User defined property */
826 	if (zfs_prop_user(property_name)) {
827 		return (zcp_get_user_prop(state, dp,
828 		    dataset_name, property_name));
829 	}
830 	/* userspace property */
831 	if (zfs_prop_userquota(property_name)) {
832 #ifdef _KERNEL
833 		return (zcp_get_userquota_prop(state, dp,
834 		    dataset_name, property_name));
835 #else
836 		return (luaL_error(state,
837 		    "user quota properties only supported in kernel mode",
838 		    property_name));
839 #endif
840 	}
841 	/* written@ property */
842 	if (zfs_prop_written(property_name)) {
843 		return (zcp_get_written_prop(state, dp,
844 		    dataset_name, property_name));
845 	}
846 
847 	zfs_prop_t zfs_prop = zfs_name_to_prop(property_name);
848 	/* Valid system property */
849 	if (zfs_prop != ZPROP_INVAL) {
850 		return (zcp_get_system_prop(state, dp, dataset_name,
851 		    zfs_prop));
852 	}
853 
854 	/* Invalid property name */
855 	return (luaL_error(state,
856 	    "'%s' is not a valid property", property_name));
857 }
858 
859 int
860 zcp_load_get_lib(lua_State *state)
861 {
862 	lua_pushcclosure(state, zcp_get_prop_info.func, 0);
863 	lua_setfield(state, -2, zcp_get_prop_info.name);
864 
865 	return (1);
866 }
867