xref: /illumos-gate/usr/src/uts/common/fs/zfs/dsl_prop.c (revision 8b80e8cb6855118d46f605e91b5ed4ce83417395)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*
22  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 #pragma ident	"%Z%%M%	%I%	%E% SMI"
27 
28 #include <sys/dmu.h>
29 #include <sys/dmu_objset.h>
30 #include <sys/dmu_tx.h>
31 #include <sys/dsl_dataset.h>
32 #include <sys/dsl_dir.h>
33 #include <sys/dsl_prop.h>
34 #include <sys/dsl_synctask.h>
35 #include <sys/spa.h>
36 #include <sys/zio_checksum.h> /* for the default checksum value */
37 #include <sys/zap.h>
38 #include <sys/fs/zfs.h>
39 
40 #include "zfs_prop.h"
41 
42 static int
43 dodefault(const char *propname, int intsz, int numint, void *buf)
44 {
45 	zfs_prop_t prop;
46 
47 	/*
48 	 * The setonce properties are read-only, BUT they still
49 	 * have a default value that can be used as the initial
50 	 * value.
51 	 */
52 	if ((prop = zfs_name_to_prop(propname)) == ZPROP_INVAL ||
53 	    (zfs_prop_readonly(prop) && !zfs_prop_setonce(prop)))
54 		return (ENOENT);
55 
56 	if (zfs_prop_get_type(prop) == PROP_TYPE_STRING) {
57 		if (intsz != 1)
58 			return (EOVERFLOW);
59 		(void) strncpy(buf, zfs_prop_default_string(prop),
60 		    numint);
61 	} else {
62 		if (intsz != 8 || numint < 1)
63 			return (EOVERFLOW);
64 
65 		*(uint64_t *)buf = zfs_prop_default_numeric(prop);
66 	}
67 
68 	return (0);
69 }
70 
71 int
72 dsl_prop_get_dd(dsl_dir_t *dd, const char *propname,
73     int intsz, int numint, void *buf, char *setpoint)
74 {
75 	int err = ENOENT;
76 	objset_t *mos = dd->dd_pool->dp_meta_objset;
77 	zfs_prop_t prop;
78 
79 	ASSERT(RW_LOCK_HELD(&dd->dd_pool->dp_config_rwlock));
80 
81 	if (setpoint)
82 		setpoint[0] = '\0';
83 
84 	prop = zfs_name_to_prop(propname);
85 
86 	/*
87 	 * Note: dd may be NULL, therefore we shouldn't dereference it
88 	 * ouside this loop.
89 	 */
90 	for (; dd != NULL; dd = dd->dd_parent) {
91 		ASSERT(RW_LOCK_HELD(&dd->dd_pool->dp_config_rwlock));
92 		err = zap_lookup(mos, dd->dd_phys->dd_props_zapobj,
93 		    propname, intsz, numint, buf);
94 		if (err != ENOENT) {
95 			if (setpoint)
96 				dsl_dir_name(dd, setpoint);
97 			break;
98 		}
99 
100 		/*
101 		 * Break out of this loop for non-inheritable properties.
102 		 */
103 		if (prop != ZPROP_INVAL && !zfs_prop_inheritable(prop))
104 			break;
105 	}
106 	if (err == ENOENT)
107 		err = dodefault(propname, intsz, numint, buf);
108 
109 	return (err);
110 }
111 
112 int
113 dsl_prop_get_ds(dsl_dataset_t *ds, const char *propname,
114     int intsz, int numint, void *buf, char *setpoint)
115 {
116 	ASSERT(RW_LOCK_HELD(&ds->ds_dir->dd_pool->dp_config_rwlock));
117 
118 	if (ds->ds_phys->ds_props_obj) {
119 		int err = zap_lookup(ds->ds_dir->dd_pool->dp_meta_objset,
120 		    ds->ds_phys->ds_props_obj, propname, intsz, numint, buf);
121 		if (err != ENOENT) {
122 			if (setpoint)
123 				dsl_dataset_name(ds, setpoint);
124 			return (err);
125 		}
126 	}
127 
128 	return (dsl_prop_get_dd(ds->ds_dir, propname,
129 	    intsz, numint, buf, setpoint));
130 }
131 
132 /*
133  * Register interest in the named property.  We'll call the callback
134  * once to notify it of the current property value, and again each time
135  * the property changes, until this callback is unregistered.
136  *
137  * Return 0 on success, errno if the prop is not an integer value.
138  */
139 int
140 dsl_prop_register(dsl_dataset_t *ds, const char *propname,
141     dsl_prop_changed_cb_t *callback, void *cbarg)
142 {
143 	dsl_dir_t *dd = ds->ds_dir;
144 	dsl_pool_t *dp = dd->dd_pool;
145 	uint64_t value;
146 	dsl_prop_cb_record_t *cbr;
147 	int err;
148 	int need_rwlock;
149 
150 	need_rwlock = !RW_WRITE_HELD(&dp->dp_config_rwlock);
151 	if (need_rwlock)
152 		rw_enter(&dp->dp_config_rwlock, RW_READER);
153 
154 	err = dsl_prop_get_ds(ds, propname, 8, 1, &value, NULL);
155 	if (err != 0) {
156 		if (need_rwlock)
157 			rw_exit(&dp->dp_config_rwlock);
158 		return (err);
159 	}
160 
161 	cbr = kmem_alloc(sizeof (dsl_prop_cb_record_t), KM_SLEEP);
162 	cbr->cbr_ds = ds;
163 	cbr->cbr_propname = kmem_alloc(strlen(propname)+1, KM_SLEEP);
164 	(void) strcpy((char *)cbr->cbr_propname, propname);
165 	cbr->cbr_func = callback;
166 	cbr->cbr_arg = cbarg;
167 	mutex_enter(&dd->dd_lock);
168 	list_insert_head(&dd->dd_prop_cbs, cbr);
169 	mutex_exit(&dd->dd_lock);
170 
171 	cbr->cbr_func(cbr->cbr_arg, value);
172 
173 	VERIFY(0 == dsl_dir_open_obj(dp, dd->dd_object,
174 	    NULL, cbr, &dd));
175 	if (need_rwlock)
176 		rw_exit(&dp->dp_config_rwlock);
177 	/* Leave dir open until this callback is unregistered */
178 	return (0);
179 }
180 
181 int
182 dsl_prop_get(const char *dsname, const char *propname,
183     int intsz, int numints, void *buf, char *setpoint)
184 {
185 	dsl_dataset_t *ds;
186 	int err;
187 
188 	err = dsl_dataset_hold(dsname, FTAG, &ds);
189 	if (err)
190 		return (err);
191 
192 	rw_enter(&ds->ds_dir->dd_pool->dp_config_rwlock, RW_READER);
193 	err = dsl_prop_get_ds(ds, propname, intsz, numints, buf, setpoint);
194 	rw_exit(&ds->ds_dir->dd_pool->dp_config_rwlock);
195 
196 	dsl_dataset_rele(ds, FTAG);
197 	return (err);
198 }
199 
200 /*
201  * Get the current property value.  It may have changed by the time this
202  * function returns, so it is NOT safe to follow up with
203  * dsl_prop_register() and assume that the value has not changed in
204  * between.
205  *
206  * Return 0 on success, ENOENT if ddname is invalid.
207  */
208 int
209 dsl_prop_get_integer(const char *ddname, const char *propname,
210     uint64_t *valuep, char *setpoint)
211 {
212 	return (dsl_prop_get(ddname, propname, 8, 1, valuep, setpoint));
213 }
214 
215 /*
216  * Unregister this callback.  Return 0 on success, ENOENT if ddname is
217  * invalid, ENOMSG if no matching callback registered.
218  */
219 int
220 dsl_prop_unregister(dsl_dataset_t *ds, const char *propname,
221     dsl_prop_changed_cb_t *callback, void *cbarg)
222 {
223 	dsl_dir_t *dd = ds->ds_dir;
224 	dsl_prop_cb_record_t *cbr;
225 
226 	mutex_enter(&dd->dd_lock);
227 	for (cbr = list_head(&dd->dd_prop_cbs);
228 	    cbr; cbr = list_next(&dd->dd_prop_cbs, cbr)) {
229 		if (cbr->cbr_ds == ds &&
230 		    cbr->cbr_func == callback &&
231 		    cbr->cbr_arg == cbarg &&
232 		    strcmp(cbr->cbr_propname, propname) == 0)
233 			break;
234 	}
235 
236 	if (cbr == NULL) {
237 		mutex_exit(&dd->dd_lock);
238 		return (ENOMSG);
239 	}
240 
241 	list_remove(&dd->dd_prop_cbs, cbr);
242 	mutex_exit(&dd->dd_lock);
243 	kmem_free((void*)cbr->cbr_propname, strlen(cbr->cbr_propname)+1);
244 	kmem_free(cbr, sizeof (dsl_prop_cb_record_t));
245 
246 	/* Clean up from dsl_prop_register */
247 	dsl_dir_close(dd, cbr);
248 	return (0);
249 }
250 
251 /*
252  * Return the number of callbacks that are registered for this dataset.
253  */
254 int
255 dsl_prop_numcb(dsl_dataset_t *ds)
256 {
257 	dsl_dir_t *dd = ds->ds_dir;
258 	dsl_prop_cb_record_t *cbr;
259 	int num = 0;
260 
261 	mutex_enter(&dd->dd_lock);
262 	for (cbr = list_head(&dd->dd_prop_cbs);
263 	    cbr; cbr = list_next(&dd->dd_prop_cbs, cbr)) {
264 		if (cbr->cbr_ds == ds)
265 			num++;
266 	}
267 	mutex_exit(&dd->dd_lock);
268 
269 	return (num);
270 }
271 
272 static void
273 dsl_prop_changed_notify(dsl_pool_t *dp, uint64_t ddobj,
274     const char *propname, uint64_t value, int first)
275 {
276 	dsl_dir_t *dd;
277 	dsl_prop_cb_record_t *cbr;
278 	objset_t *mos = dp->dp_meta_objset;
279 	zap_cursor_t zc;
280 	zap_attribute_t *za;
281 	int err;
282 	uint64_t dummyval;
283 
284 	ASSERT(RW_WRITE_HELD(&dp->dp_config_rwlock));
285 	err = dsl_dir_open_obj(dp, ddobj, NULL, FTAG, &dd);
286 	if (err)
287 		return;
288 
289 	if (!first) {
290 		/*
291 		 * If the prop is set here, then this change is not
292 		 * being inherited here or below; stop the recursion.
293 		 */
294 		err = zap_lookup(mos, dd->dd_phys->dd_props_zapobj, propname,
295 		    8, 1, &dummyval);
296 		if (err == 0) {
297 			dsl_dir_close(dd, FTAG);
298 			return;
299 		}
300 		ASSERT3U(err, ==, ENOENT);
301 	}
302 
303 	mutex_enter(&dd->dd_lock);
304 	for (cbr = list_head(&dd->dd_prop_cbs); cbr;
305 	    cbr = list_next(&dd->dd_prop_cbs, cbr)) {
306 		uint64_t propobj = cbr->cbr_ds->ds_phys->ds_props_obj;
307 
308 		if (strcmp(cbr->cbr_propname, propname) != 0)
309 			continue;
310 
311 		/*
312 		 * If the property is set on this ds, then it is not
313 		 * inherited here; don't call the callback.
314 		 */
315 		if (propobj && 0 == zap_lookup(mos, propobj, propname,
316 		    8, 1, &dummyval))
317 			continue;
318 
319 		cbr->cbr_func(cbr->cbr_arg, value);
320 	}
321 	mutex_exit(&dd->dd_lock);
322 
323 	za = kmem_alloc(sizeof (zap_attribute_t), KM_SLEEP);
324 	for (zap_cursor_init(&zc, mos,
325 	    dd->dd_phys->dd_child_dir_zapobj);
326 	    zap_cursor_retrieve(&zc, za) == 0;
327 	    zap_cursor_advance(&zc)) {
328 		dsl_prop_changed_notify(dp, za->za_first_integer,
329 		    propname, value, FALSE);
330 	}
331 	kmem_free(za, sizeof (zap_attribute_t));
332 	zap_cursor_fini(&zc);
333 	dsl_dir_close(dd, FTAG);
334 }
335 
336 struct prop_set_arg {
337 	const char *name;
338 	int intsz;
339 	int numints;
340 	const void *buf;
341 };
342 
343 
344 static void
345 dsl_prop_set_sync(void *arg1, void *arg2, cred_t *cr, dmu_tx_t *tx)
346 {
347 	dsl_dataset_t *ds = arg1;
348 	struct prop_set_arg *psa = arg2;
349 	objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
350 	uint64_t zapobj, intval;
351 	int isint;
352 	char valbuf[32];
353 	char *valstr;
354 
355 	isint = (dodefault(psa->name, 8, 1, &intval) == 0);
356 
357 	if (dsl_dataset_is_snapshot(ds)) {
358 		ASSERT(spa_version(ds->ds_dir->dd_pool->dp_spa) >=
359 		    SPA_VERSION_SNAP_PROPS);
360 		if (ds->ds_phys->ds_props_obj == 0) {
361 			dmu_buf_will_dirty(ds->ds_dbuf, tx);
362 			ds->ds_phys->ds_props_obj =
363 			    zap_create(mos,
364 			    DMU_OT_DSL_PROPS, DMU_OT_NONE, 0, tx);
365 		}
366 		zapobj = ds->ds_phys->ds_props_obj;
367 	} else {
368 		zapobj = ds->ds_dir->dd_phys->dd_props_zapobj;
369 	}
370 
371 	if (psa->numints == 0) {
372 		int err = zap_remove(mos, zapobj, psa->name, tx);
373 		ASSERT(err == 0 || err == ENOENT);
374 		if (isint) {
375 			VERIFY(0 == dsl_prop_get_ds(ds,
376 			    psa->name, 8, 1, &intval, NULL));
377 		}
378 	} else {
379 		VERIFY(0 == zap_update(mos, zapobj, psa->name,
380 		    psa->intsz, psa->numints, psa->buf, tx));
381 		if (isint)
382 			intval = *(uint64_t *)psa->buf;
383 	}
384 
385 	if (isint) {
386 		if (dsl_dataset_is_snapshot(ds)) {
387 			dsl_prop_cb_record_t *cbr;
388 			/*
389 			 * It's a snapshot; nothing can inherit this
390 			 * property, so just look for callbacks on this
391 			 * ds here.
392 			 */
393 			mutex_enter(&ds->ds_dir->dd_lock);
394 			for (cbr = list_head(&ds->ds_dir->dd_prop_cbs); cbr;
395 			    cbr = list_next(&ds->ds_dir->dd_prop_cbs, cbr)) {
396 				if (cbr->cbr_ds == ds &&
397 				    strcmp(cbr->cbr_propname, psa->name) == 0)
398 					cbr->cbr_func(cbr->cbr_arg, intval);
399 			}
400 			mutex_exit(&ds->ds_dir->dd_lock);
401 		} else {
402 			dsl_prop_changed_notify(ds->ds_dir->dd_pool,
403 			    ds->ds_dir->dd_object, psa->name, intval, TRUE);
404 		}
405 	}
406 	if (isint) {
407 		(void) snprintf(valbuf, sizeof (valbuf),
408 		    "%lld", (longlong_t)intval);
409 		valstr = valbuf;
410 	} else {
411 		valstr = (char *)psa->buf;
412 	}
413 	spa_history_internal_log((psa->numints == 0) ? LOG_DS_INHERIT :
414 	    LOG_DS_PROPSET, ds->ds_dir->dd_pool->dp_spa, tx, cr,
415 	    "%s=%s dataset = %llu", psa->name, valstr, ds->ds_object);
416 }
417 
418 void
419 dsl_prop_set_uint64_sync(dsl_dir_t *dd, const char *name, uint64_t val,
420     cred_t *cr, dmu_tx_t *tx)
421 {
422 	objset_t *mos = dd->dd_pool->dp_meta_objset;
423 	uint64_t zapobj = dd->dd_phys->dd_props_zapobj;
424 
425 	ASSERT(dmu_tx_is_syncing(tx));
426 
427 	VERIFY(0 == zap_update(mos, zapobj, name, sizeof (val), 1, &val, tx));
428 
429 	dsl_prop_changed_notify(dd->dd_pool, dd->dd_object, name, val, TRUE);
430 
431 	spa_history_internal_log(LOG_DS_PROPSET, dd->dd_pool->dp_spa, tx, cr,
432 	    "%s=%llu dataset = %llu", name, (u_longlong_t)val,
433 	    dd->dd_phys->dd_head_dataset_obj);
434 }
435 
436 int
437 dsl_prop_set(const char *dsname, const char *propname,
438     int intsz, int numints, const void *buf)
439 {
440 	dsl_dataset_t *ds;
441 	int err;
442 	struct prop_set_arg psa;
443 
444 	/*
445 	 * We must do these checks before we get to the syncfunc, since
446 	 * it can't fail.
447 	 */
448 	if (strlen(propname) >= ZAP_MAXNAMELEN)
449 		return (ENAMETOOLONG);
450 	if (intsz * numints >= ZAP_MAXVALUELEN)
451 		return (E2BIG);
452 
453 	err = dsl_dataset_hold(dsname, FTAG, &ds);
454 	if (err)
455 		return (err);
456 
457 	if (dsl_dataset_is_snapshot(ds) &&
458 	    spa_version(ds->ds_dir->dd_pool->dp_spa) < SPA_VERSION_SNAP_PROPS) {
459 		dsl_dataset_rele(ds, FTAG);
460 		return (ENOTSUP);
461 	}
462 
463 	psa.name = propname;
464 	psa.intsz = intsz;
465 	psa.numints = numints;
466 	psa.buf = buf;
467 	err = dsl_sync_task_do(ds->ds_dir->dd_pool,
468 	    NULL, dsl_prop_set_sync, ds, &psa, 2);
469 
470 	dsl_dataset_rele(ds, FTAG);
471 	return (err);
472 }
473 
474 /*
475  * Iterate over all properties for this dataset and return them in an nvlist.
476  */
477 int
478 dsl_prop_get_all(objset_t *os, nvlist_t **nvp, boolean_t local)
479 {
480 	dsl_dataset_t *ds = os->os->os_dsl_dataset;
481 	dsl_dir_t *dd = ds->ds_dir;
482 	boolean_t snapshot = dsl_dataset_is_snapshot(ds);
483 	int err = 0;
484 	dsl_pool_t *dp = dd->dd_pool;
485 	objset_t *mos = dp->dp_meta_objset;
486 	uint64_t propobj = ds->ds_phys->ds_props_obj;
487 
488 	VERIFY(nvlist_alloc(nvp, NV_UNIQUE_NAME, KM_SLEEP) == 0);
489 
490 	if (local && snapshot && !propobj)
491 		return (0);
492 
493 	rw_enter(&dp->dp_config_rwlock, RW_READER);
494 	while (dd != NULL) {
495 		char setpoint[MAXNAMELEN];
496 		zap_cursor_t zc;
497 		zap_attribute_t za;
498 		dsl_dir_t *dd_next;
499 
500 		if (propobj) {
501 			dsl_dataset_name(ds, setpoint);
502 			dd_next = dd;
503 		} else {
504 			dsl_dir_name(dd, setpoint);
505 			propobj = dd->dd_phys->dd_props_zapobj;
506 			dd_next = dd->dd_parent;
507 		}
508 
509 		for (zap_cursor_init(&zc, mos, propobj);
510 		    (err = zap_cursor_retrieve(&zc, &za)) == 0;
511 		    zap_cursor_advance(&zc)) {
512 			nvlist_t *propval;
513 			zfs_prop_t prop = zfs_name_to_prop(za.za_name);
514 
515 			/* Skip non-inheritable properties. */
516 			if (prop != ZPROP_INVAL &&
517 			    !zfs_prop_inheritable(prop) &&
518 			    (dd != ds->ds_dir || (snapshot && dd != dd_next)))
519 				continue;
520 
521 			/* Skip properties not valid for this type. */
522 			if (snapshot && prop != ZPROP_INVAL &&
523 			    !zfs_prop_valid_for_type(prop, ZFS_TYPE_SNAPSHOT))
524 				continue;
525 
526 			/* Skip properties already defined */
527 			if (nvlist_lookup_nvlist(*nvp, za.za_name,
528 			    &propval) == 0)
529 				continue;
530 
531 			VERIFY(nvlist_alloc(&propval, NV_UNIQUE_NAME,
532 			    KM_SLEEP) == 0);
533 			if (za.za_integer_length == 1) {
534 				/*
535 				 * String property
536 				 */
537 				char *tmp = kmem_alloc(za.za_num_integers,
538 				    KM_SLEEP);
539 				err = zap_lookup(mos, propobj,
540 				    za.za_name, 1, za.za_num_integers, tmp);
541 				if (err != 0) {
542 					kmem_free(tmp, za.za_num_integers);
543 					break;
544 				}
545 				VERIFY(nvlist_add_string(propval, ZPROP_VALUE,
546 				    tmp) == 0);
547 				kmem_free(tmp, za.za_num_integers);
548 			} else {
549 				/*
550 				 * Integer property
551 				 */
552 				ASSERT(za.za_integer_length == 8);
553 				(void) nvlist_add_uint64(propval, ZPROP_VALUE,
554 				    za.za_first_integer);
555 			}
556 
557 			VERIFY(nvlist_add_string(propval, ZPROP_SOURCE,
558 			    setpoint) == 0);
559 			VERIFY(nvlist_add_nvlist(*nvp, za.za_name,
560 			    propval) == 0);
561 			nvlist_free(propval);
562 		}
563 		zap_cursor_fini(&zc);
564 
565 		if (err != ENOENT)
566 			break;
567 		err = 0;
568 		/*
569 		 * If we are just after the props that have been set
570 		 * locally, then we are done after the first iteration.
571 		 */
572 		if (local)
573 			break;
574 		dd = dd_next;
575 		propobj = 0;
576 	}
577 	rw_exit(&dp->dp_config_rwlock);
578 
579 	return (err);
580 }
581 
582 void
583 dsl_prop_nvlist_add_uint64(nvlist_t *nv, zfs_prop_t prop, uint64_t value)
584 {
585 	nvlist_t *propval;
586 
587 	VERIFY(nvlist_alloc(&propval, NV_UNIQUE_NAME, KM_SLEEP) == 0);
588 	VERIFY(nvlist_add_uint64(propval, ZPROP_VALUE, value) == 0);
589 	VERIFY(nvlist_add_nvlist(nv, zfs_prop_to_name(prop), propval) == 0);
590 	nvlist_free(propval);
591 }
592 
593 void
594 dsl_prop_nvlist_add_string(nvlist_t *nv, zfs_prop_t prop, const char *value)
595 {
596 	nvlist_t *propval;
597 
598 	VERIFY(nvlist_alloc(&propval, NV_UNIQUE_NAME, KM_SLEEP) == 0);
599 	VERIFY(nvlist_add_string(propval, ZPROP_VALUE, value) == 0);
600 	VERIFY(nvlist_add_nvlist(nv, zfs_prop_to_name(prop), propval) == 0);
601 	nvlist_free(propval);
602 }
603