zcp_get.c revision 332525
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 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
45static int
46get_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 */
74static int
75get_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 */
102static void
103get_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 */
122static int
123zcp_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 */
148static int
149zcp_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 */
185static int
186get_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 */
221static int
222get_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#ifdef illumos
230	zfsvfs_t *zfvp;
231#endif
232	vfs_t *vfsp;
233	objset_t *os;
234	uint64_t tmp = *val;
235
236	error = dmu_objset_from_ds(ds, &os);
237	if (error != 0)
238		return (error);
239
240	error = getzfsvfs_impl(os, &vfsp);
241	if (error != 0)
242		return (error);
243#ifdef illumos
244	vfsp = zfvp->z_vfs;
245#endif
246	switch (zfs_prop) {
247	case ZFS_PROP_ATIME:
248		if (vfs_optionisset(vfsp, MNTOPT_NOATIME, NULL))
249			tmp = 0;
250		if (vfs_optionisset(vfsp, MNTOPT_ATIME, NULL))
251			tmp = 1;
252		break;
253	case ZFS_PROP_DEVICES:
254		if (vfs_optionisset(vfsp, MNTOPT_NODEVICES, NULL))
255			tmp = 0;
256		if (vfs_optionisset(vfsp, MNTOPT_DEVICES, NULL))
257			tmp = 1;
258		break;
259	case ZFS_PROP_EXEC:
260		if (vfs_optionisset(vfsp, MNTOPT_NOEXEC, NULL))
261			tmp = 0;
262		if (vfs_optionisset(vfsp, MNTOPT_EXEC, NULL))
263			tmp = 1;
264		break;
265	case ZFS_PROP_SETUID:
266		if (vfs_optionisset(vfsp, MNTOPT_NOSETUID, NULL))
267			tmp = 0;
268		if (vfs_optionisset(vfsp, MNTOPT_SETUID, NULL))
269			tmp = 1;
270		break;
271	case ZFS_PROP_READONLY:
272		if (vfs_optionisset(vfsp, MNTOPT_RW, NULL))
273			tmp = 0;
274		if (vfs_optionisset(vfsp, MNTOPT_RO, NULL))
275			tmp = 1;
276		break;
277	case ZFS_PROP_XATTR:
278		if (vfs_optionisset(vfsp, MNTOPT_NOXATTR, NULL))
279			tmp = 0;
280		if (vfs_optionisset(vfsp, MNTOPT_XATTR, NULL))
281			tmp = 1;
282		break;
283	case ZFS_PROP_NBMAND:
284		if (vfs_optionisset(vfsp, MNTOPT_NONBMAND, NULL))
285			tmp = 0;
286		if (vfs_optionisset(vfsp, MNTOPT_NBMAND, NULL))
287			tmp = 1;
288		break;
289	default:
290#ifdef illumos
291		VFS_RELE(vfsp);
292#else
293		vfs_rel(vfsp);
294#endif
295		return (ENOENT);
296	}
297
298#ifdef illumos
299	VFS_RELE(vfsp);
300#else
301	vfs_rel(vfsp);
302#endif
303	if (tmp != *val) {
304		(void) strcpy(setpoint, "temporary");
305		*val = tmp;
306	}
307	return (0);
308#endif
309}
310
311/*
312 * Check if the property we're looking for is stored at the dsl_dataset or
313 * dsl_dir level. If so, push the property value and source onto the lua stack
314 * and return 0. If it is not present or a failure occurs in lookup, return a
315 * non-zero error value.
316 */
317static int
318get_special_prop(lua_State *state, dsl_dataset_t *ds, const char *dsname,
319    zfs_prop_t zfs_prop)
320{
321	int error = 0;
322	objset_t *os;
323	uint64_t numval;
324	char *strval = kmem_alloc(ZAP_MAXVALUELEN, KM_SLEEP);
325	char setpoint[ZFS_MAX_DATASET_NAME_LEN] =
326	    "Internal error - setpoint not determined";
327	zfs_type_t ds_type;
328	zprop_type_t prop_type = zfs_prop_get_type(zfs_prop);
329	(void) get_objset_type(ds, &ds_type);
330
331	switch (zfs_prop) {
332	case ZFS_PROP_REFRATIO:
333		numval = dsl_get_refratio(ds);
334		break;
335	case ZFS_PROP_USED:
336		numval = dsl_get_used(ds);
337		break;
338	case ZFS_PROP_CLONES: {
339		nvlist_t *clones = fnvlist_alloc();
340		error = get_clones_stat_impl(ds, clones);
341		if (error == 0) {
342			/* push list to lua stack */
343			VERIFY0(zcp_nvlist_to_lua(state, clones, NULL, 0));
344			/* source */
345			(void) lua_pushnil(state);
346		}
347		nvlist_free(clones);
348		kmem_free(strval, ZAP_MAXVALUELEN);
349		return (error);
350	}
351	case ZFS_PROP_COMPRESSRATIO:
352		numval = dsl_get_compressratio(ds);
353		break;
354	case ZFS_PROP_CREATION:
355		numval = dsl_get_creation(ds);
356		break;
357	case ZFS_PROP_REFERENCED:
358		numval = dsl_get_referenced(ds);
359		break;
360	case ZFS_PROP_AVAILABLE:
361		numval = dsl_get_available(ds);
362		break;
363	case ZFS_PROP_LOGICALREFERENCED:
364		numval = dsl_get_logicalreferenced(ds);
365		break;
366	case ZFS_PROP_CREATETXG:
367		numval = dsl_get_creationtxg(ds);
368		break;
369	case ZFS_PROP_GUID:
370		numval = dsl_get_guid(ds);
371		break;
372	case ZFS_PROP_UNIQUE:
373		numval = dsl_get_unique(ds);
374		break;
375	case ZFS_PROP_OBJSETID:
376		numval = dsl_get_objsetid(ds);
377		break;
378	case ZFS_PROP_ORIGIN:
379		dsl_dir_get_origin(ds->ds_dir, strval);
380		break;
381	case ZFS_PROP_USERACCOUNTING:
382		error = dmu_objset_from_ds(ds, &os);
383		if (error == 0)
384			numval = dmu_objset_userspace_present(os);
385		break;
386	case ZFS_PROP_WRITTEN:
387		error = dsl_get_written(ds, &numval);
388		break;
389	case ZFS_PROP_TYPE:
390		error = get_objset_type_name(ds, strval);
391		break;
392	case ZFS_PROP_PREV_SNAP:
393		error = dsl_get_prev_snap(ds, strval);
394		break;
395	case ZFS_PROP_NAME:
396		dsl_dataset_name(ds, strval);
397		break;
398	case ZFS_PROP_MOUNTPOINT:
399		error = dsl_get_mountpoint(ds, dsname, strval, setpoint);
400		break;
401	case ZFS_PROP_VERSION:
402		/* should be a snapshot or filesystem */
403		ASSERT(ds_type != ZFS_TYPE_VOLUME);
404		error = dmu_objset_from_ds(ds, &os);
405		/* look in the master node for the version */
406		if (error == 0) {
407			error = zap_lookup(os, MASTER_NODE_OBJ, ZPL_VERSION_STR,
408			    sizeof (numval), 1, &numval);
409		}
410		break;
411	case ZFS_PROP_DEFER_DESTROY:
412		numval = dsl_get_defer_destroy(ds);
413		break;
414	case ZFS_PROP_USERREFS:
415		numval = dsl_get_userrefs(ds);
416		break;
417	case ZFS_PROP_FILESYSTEM_COUNT:
418		error = dsl_dir_get_filesystem_count(ds->ds_dir, &numval);
419		(void) strcpy(setpoint, "");
420		break;
421	case ZFS_PROP_SNAPSHOT_COUNT:
422		error = dsl_dir_get_snapshot_count(ds->ds_dir, &numval);
423		(void) strcpy(setpoint, "");
424		break;
425	case ZFS_PROP_REMAPTXG:
426		error = dsl_dir_get_remaptxg(ds->ds_dir, &numval);
427		break;
428	case ZFS_PROP_NUMCLONES:
429		numval = dsl_get_numclones(ds);
430		break;
431	case ZFS_PROP_INCONSISTENT:
432		numval = dsl_get_inconsistent(ds);
433		break;
434	case ZFS_PROP_RECEIVE_RESUME_TOKEN:
435		VERIFY3U(strlcpy(strval, get_receive_resume_stats_impl(ds),
436		    ZAP_MAXVALUELEN), <, ZAP_MAXVALUELEN);
437		if (strcmp(strval, "") == 0) {
438			VERIFY3U(strlcpy(strval, get_child_receive_stats(ds),
439			    ZAP_MAXVALUELEN), <, ZAP_MAXVALUELEN);
440			if (strcmp(strval, "") == 0)
441				error = ENOENT;
442		}
443		break;
444	case ZFS_PROP_VOLSIZE:
445		ASSERT(ds_type == ZFS_TYPE_VOLUME);
446		error = dmu_objset_from_ds(ds, &os);
447		if (error == 0) {
448			error = zap_lookup(os, ZVOL_ZAP_OBJ, "size",
449			    sizeof (numval), 1, &numval);
450		}
451		if (error == 0)
452			(void) strcpy(setpoint, dsname);
453
454		break;
455	case ZFS_PROP_VOLBLOCKSIZE: {
456		ASSERT(ds_type == ZFS_TYPE_VOLUME);
457		dmu_object_info_t doi;
458		error = dmu_objset_from_ds(ds, &os);
459		if (error == 0) {
460			error = dmu_object_info(os, ZVOL_OBJ, &doi);
461			if (error == 0)
462				numval = doi.doi_data_block_size;
463		}
464		break;
465	}
466	default:
467		/* Did not match these props, check in the dsl_dir */
468		error = get_dsl_dir_prop(ds, zfs_prop, &numval);
469	}
470	if (error != 0) {
471		kmem_free(strval, ZAP_MAXVALUELEN);
472		return (error);
473	}
474
475	switch (prop_type) {
476	case PROP_TYPE_NUMBER: {
477		(void) lua_pushnumber(state, numval);
478		break;
479	}
480	case PROP_TYPE_STRING: {
481		(void) lua_pushstring(state, strval);
482		break;
483	}
484	case PROP_TYPE_INDEX: {
485		const char *propval;
486		error = zfs_prop_index_to_string(zfs_prop, numval, &propval);
487		if (error != 0) {
488			kmem_free(strval, ZAP_MAXVALUELEN);
489			return (error);
490		}
491		(void) lua_pushstring(state, propval);
492		break;
493	}
494	}
495	kmem_free(strval, ZAP_MAXVALUELEN);
496
497	/* Push the source to the stack */
498	get_prop_src(state, setpoint, zfs_prop);
499	return (0);
500}
501
502/*
503 * Look up a property and its source in the zap object. If the value is
504 * present and successfully retrieved, push the value and source on the
505 * lua stack and return 0. On failure, return a non-zero error value.
506 */
507static int
508get_zap_prop(lua_State *state, dsl_dataset_t *ds, zfs_prop_t zfs_prop)
509{
510	int error = 0;
511	char setpoint[ZFS_MAX_DATASET_NAME_LEN];
512	char *strval = kmem_alloc(ZAP_MAXVALUELEN, KM_SLEEP);
513	uint64_t numval;
514	const char *prop_name = zfs_prop_to_name(zfs_prop);
515	zprop_type_t prop_type = zfs_prop_get_type(zfs_prop);
516
517	if (prop_type == PROP_TYPE_STRING) {
518		/* Push value to lua stack */
519		error = dsl_prop_get_ds(ds, prop_name, 1,
520		    ZAP_MAXVALUELEN, strval, setpoint);
521		if (error == 0)
522			(void) lua_pushstring(state, strval);
523	} else {
524		error = dsl_prop_get_ds(ds, prop_name, sizeof (numval),
525		    1, &numval, setpoint);
526
527		/* Fill in temorary value for prop, if applicable */
528		(void) get_temporary_prop(ds, zfs_prop, &numval, setpoint);
529
530		/* Push value to lua stack */
531		if (prop_type == PROP_TYPE_INDEX) {
532			const char *propval;
533			error = zfs_prop_index_to_string(zfs_prop, numval,
534			    &propval);
535			if (error == 0)
536				(void) lua_pushstring(state, propval);
537		} else {
538			if (error == 0)
539				(void) lua_pushnumber(state, numval);
540		}
541	}
542	kmem_free(strval, ZAP_MAXVALUELEN);
543	if (error == 0)
544		get_prop_src(state, setpoint, zfs_prop);
545	return (error);
546}
547
548/*
549 * Determine whether property is valid for a given dataset
550 */
551boolean_t
552prop_valid_for_ds(dsl_dataset_t *ds, zfs_prop_t zfs_prop)
553{
554	int error;
555	zfs_type_t zfs_type;
556
557	/* properties not supported */
558	if ((zfs_prop == ZFS_PROP_ISCSIOPTIONS) ||
559	    (zfs_prop == ZFS_PROP_MOUNTED))
560		return (B_FALSE);
561
562	/* if we want the origin prop, ds must be a clone */
563	if ((zfs_prop == ZFS_PROP_ORIGIN) && (!dsl_dir_is_clone(ds->ds_dir)))
564		return (B_FALSE);
565
566	error = get_objset_type(ds, &zfs_type);
567	if (error != 0)
568		return (B_FALSE);
569	return (zfs_prop_valid_for_type(zfs_prop, zfs_type));
570}
571
572/*
573 * Look up a given dataset property. On success return 2, the number of
574 * values pushed to the lua stack (property value and source). On a fatal
575 * error, longjmp. On a non fatal error push nothing.
576 */
577static int
578zcp_get_system_prop(lua_State *state, dsl_pool_t *dp, const char *dataset_name,
579    zfs_prop_t zfs_prop)
580{
581	int error;
582	/*
583	 * zcp_dataset_hold will either successfully return the requested
584	 * dataset or throw a lua error and longjmp out of the zfs.get_prop call
585	 * without returning.
586	 */
587	dsl_dataset_t *ds = zcp_dataset_hold(state, dp, dataset_name, FTAG);
588	if (ds == NULL)
589		return (1); /* not reached; zcp_dataset_hold() longjmp'd */
590
591	/* Check that the property is valid for the given dataset */
592	const char *prop_name = zfs_prop_to_name(zfs_prop);
593	if (!prop_valid_for_ds(ds, zfs_prop)) {
594		dsl_dataset_rele(ds, FTAG);
595		return (0);
596	}
597
598	/* Check if the property can be accessed directly */
599	error = get_special_prop(state, ds, dataset_name, zfs_prop);
600	if (error == 0) {
601		dsl_dataset_rele(ds, FTAG);
602		/* The value and source have been pushed by get_special_prop */
603		return (2);
604	}
605	if (error != ENOENT) {
606		dsl_dataset_rele(ds, FTAG);
607		return (zcp_handle_error(state, dataset_name,
608		    prop_name, error));
609	}
610
611	/* If we were unable to find it, look in the zap object */
612	error = get_zap_prop(state, ds, zfs_prop);
613	dsl_dataset_rele(ds, FTAG);
614	if (error != 0) {
615		return (zcp_handle_error(state, dataset_name,
616		    prop_name, error));
617	}
618	/* The value and source have been pushed by get_zap_prop */
619	return (2);
620}
621
622static zfs_userquota_prop_t
623get_userquota_prop(const char *prop_name)
624{
625	zfs_userquota_prop_t type;
626	/* Figure out the property type ({user|group}{quota|used}) */
627	for (type = 0; type < ZFS_NUM_USERQUOTA_PROPS; type++) {
628		if (strncmp(prop_name, zfs_userquota_prop_prefixes[type],
629		    strlen(zfs_userquota_prop_prefixes[type])) == 0)
630			break;
631	}
632	return (type);
633}
634
635#ifdef _KERNEL
636/*
637 * Given the name of a zfs_userquota_prop, this function determines the
638 * prop type as well as the numeric group/user ids based on the string
639 * following the '@' in the property name. On success, returns 0. On failure,
640 * returns a non-zero error.
641 * 'domain' must be free'd by caller using strfree()
642 */
643static int
644parse_userquota_prop(const char *prop_name, zfs_userquota_prop_t *type,
645    char **domain, uint64_t *rid)
646{
647	char *cp, *end, *domain_val;
648
649	*type = get_userquota_prop(prop_name);
650	if (*type >= ZFS_NUM_USERQUOTA_PROPS)
651		return (EINVAL);
652
653	*rid = 0;
654	cp = strchr(prop_name, '@') + 1;
655	if (strncmp(cp, "S-1-", 4) == 0) {
656		/*
657		 * It's a numeric SID (eg "S-1-234-567-89") and we want to
658		 * seperate the domain id and the rid
659		 */
660		int domain_len = strrchr(cp, '-') - cp;
661		domain_val = kmem_alloc(domain_len + 1, KM_SLEEP);
662		(void) strncpy(domain_val, cp, domain_len);
663		domain_val[domain_len] = '\0';
664		cp += domain_len + 1;
665
666		(void) ddi_strtoll(cp, &end, 10, (longlong_t *)rid);
667		if (*end != '\0') {
668			strfree(domain_val);
669			return (EINVAL);
670		}
671	} else {
672		/* It's only a user/group ID (eg "12345"), just get the rid */
673		domain_val = NULL;
674		(void) ddi_strtoll(cp, &end, 10, (longlong_t *)rid);
675		if (*end != '\0')
676			return (EINVAL);
677	}
678	*domain = domain_val;
679	return (0);
680}
681
682/*
683 * Look up {user|group}{quota|used} property for given dataset. On success
684 * push the value (quota or used amount) and the setpoint. On failure, push
685 * a lua error.
686 */
687static int
688zcp_get_userquota_prop(lua_State *state, dsl_pool_t *dp,
689    const char *dataset_name, const char *prop_name)
690{
691	zfsvfs_t *zfvp;
692	zfsvfs_t *zfsvfs;
693	int error;
694	zfs_userquota_prop_t type;
695	char *domain;
696	uint64_t rid, value;
697	objset_t *os;
698
699	dsl_dataset_t *ds = zcp_dataset_hold(state, dp, dataset_name, FTAG);
700	if (ds == NULL)
701		return (1); /* not reached; zcp_dataset_hold() longjmp'd */
702
703	error = parse_userquota_prop(prop_name, &type, &domain, &rid);
704	if (error == 0) {
705		error = dmu_objset_from_ds(ds, &os);
706		if (error == 0) {
707			zfsvfs = kmem_zalloc(sizeof (zfsvfs_t), KM_SLEEP);
708			error = zfsvfs_create_impl(&zfvp, zfsvfs, os);
709			if (error == 0) {
710				error = zfs_userspace_one(zfvp, type, domain,
711				    rid, &value);
712				zfsvfs_free(zfvp);
713			}
714		}
715		if (domain != NULL)
716			strfree(domain);
717	}
718	dsl_dataset_rele(ds, FTAG);
719
720	if ((value == 0) && ((type == ZFS_PROP_USERQUOTA) ||
721	    (type == ZFS_PROP_GROUPQUOTA)))
722		error = ENOENT;
723	if (error != 0) {
724		return (zcp_handle_error(state, dataset_name,
725		    prop_name, error));
726	}
727
728	(void) lua_pushnumber(state, value);
729	(void) lua_pushstring(state, dataset_name);
730	return (2);
731}
732#endif
733
734/*
735 * Determines the name of the snapshot referenced in the written property
736 * name. Returns snapshot name in snap_name, a buffer that must be at least
737 * as large as ZFS_MAX_DATASET_NAME_LEN
738 */
739static void
740parse_written_prop(const char *dataset_name, const char *prop_name,
741    char *snap_name)
742{
743	ASSERT(zfs_prop_written(prop_name));
744	const char *name = prop_name + ZFS_WRITTEN_PROP_PREFIX_LEN;
745	if (strchr(name, '@') == NULL) {
746		(void) sprintf(snap_name, "%s@%s", dataset_name, name);
747	} else {
748		(void) strcpy(snap_name, name);
749	}
750}
751
752/*
753 * Look up written@ property for given dataset. On success
754 * push the value and the setpoint. If error is fatal, we will
755 * longjmp, otherwise push nothing.
756 */
757static int
758zcp_get_written_prop(lua_State *state, dsl_pool_t *dp,
759    const char *dataset_name, const char *prop_name)
760{
761	char snap_name[ZFS_MAX_DATASET_NAME_LEN];
762	uint64_t used, comp, uncomp;
763	dsl_dataset_t *old;
764	int error = 0;
765
766	parse_written_prop(dataset_name, prop_name, snap_name);
767	dsl_dataset_t *new = zcp_dataset_hold(state, dp, dataset_name, FTAG);
768	if (new == NULL)
769		return (1); /* not reached; zcp_dataset_hold() longjmp'd */
770
771	error = dsl_dataset_hold(dp, snap_name, FTAG, &old);
772	if (error != 0) {
773		dsl_dataset_rele(new, FTAG);
774		return (zcp_dataset_hold_error(state, dp, snap_name,
775		    error));
776	}
777	error = dsl_dataset_space_written(old, new,
778	    &used, &comp, &uncomp);
779
780	dsl_dataset_rele(old, FTAG);
781	dsl_dataset_rele(new, FTAG);
782
783	if (error != 0) {
784		return (zcp_handle_error(state, dataset_name,
785		    snap_name, error));
786	}
787	(void) lua_pushnumber(state, used);
788	(void) lua_pushstring(state, dataset_name);
789	return (2);
790}
791
792static int zcp_get_prop(lua_State *state);
793static zcp_lib_info_t zcp_get_prop_info = {
794	.name = "get_prop",
795	.func = zcp_get_prop,
796	.pargs = {
797	    { .za_name = "dataset", .za_lua_type = LUA_TSTRING},
798	    { .za_name = "property", .za_lua_type =  LUA_TSTRING},
799	    {NULL, 0}
800	},
801	.kwargs = {
802	    {NULL, 0}
803	}
804};
805
806static int
807zcp_get_prop(lua_State *state)
808{
809	const char *dataset_name;
810	const char *property_name;
811	dsl_pool_t *dp = zcp_run_info(state)->zri_pool;
812	zcp_lib_info_t *libinfo = &zcp_get_prop_info;
813
814	zcp_parse_args(state, libinfo->name, libinfo->pargs, libinfo->kwargs);
815
816	dataset_name = lua_tostring(state, 1);
817	property_name = lua_tostring(state, 2);
818
819	/* User defined property */
820	if (zfs_prop_user(property_name)) {
821		return (zcp_get_user_prop(state, dp,
822		    dataset_name, property_name));
823	}
824	/* userspace property */
825	if (zfs_prop_userquota(property_name)) {
826#ifdef _KERNEL
827		return (zcp_get_userquota_prop(state, dp,
828		    dataset_name, property_name));
829#else
830		return (luaL_error(state,
831		    "user quota properties only supported in kernel mode",
832		    property_name));
833#endif
834	}
835	/* written@ property */
836	if (zfs_prop_written(property_name)) {
837		return (zcp_get_written_prop(state, dp,
838		    dataset_name, property_name));
839	}
840
841	zfs_prop_t zfs_prop = zfs_name_to_prop(property_name);
842	/* Valid system property */
843	if (zfs_prop != ZPROP_INVAL) {
844		return (zcp_get_system_prop(state, dp, dataset_name,
845		    zfs_prop));
846	}
847
848	/* Invalid property name */
849	return (luaL_error(state,
850	    "'%s' is not a valid property", property_name));
851}
852
853int
854zcp_load_get_lib(lua_State *state)
855{
856	lua_pushcclosure(state, zcp_get_prop_info.func, 0);
857	lua_setfield(state, -2, zcp_get_prop_info.name);
858
859	return (1);
860}
861