xref: /titanic_52/usr/src/uts/common/fs/zfs/dsl_prop.c (revision a93a1f58a8763fa69172980b98e3d24720c1136e)
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 2007 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 	if ((prop = zfs_name_to_prop(propname)) == ZPROP_INVAL ||
48 	    zfs_prop_readonly(prop))
49 		return (ENOENT);
50 
51 	if (zfs_prop_get_type(prop) == PROP_TYPE_STRING) {
52 		if (intsz != 1)
53 			return (EOVERFLOW);
54 		(void) strncpy(buf, zfs_prop_default_string(prop),
55 		    numint);
56 	} else {
57 		if (intsz != 8 || numint < 1)
58 			return (EOVERFLOW);
59 
60 		*(uint64_t *)buf = zfs_prop_default_numeric(prop);
61 	}
62 
63 	return (0);
64 }
65 
66 static int
67 dsl_prop_get_impl(dsl_dir_t *dd, const char *propname,
68     int intsz, int numint, void *buf, char *setpoint)
69 {
70 	int err = ENOENT;
71 	zfs_prop_t prop;
72 
73 	if (setpoint)
74 		setpoint[0] = '\0';
75 
76 	prop = zfs_name_to_prop(propname);
77 
78 	/*
79 	 * Note: dd may be NULL, therefore we shouldn't dereference it
80 	 * ouside this loop.
81 	 */
82 	for (; dd != NULL; dd = dd->dd_parent) {
83 		objset_t *mos = dd->dd_pool->dp_meta_objset;
84 		ASSERT(RW_LOCK_HELD(&dd->dd_pool->dp_config_rwlock));
85 		err = zap_lookup(mos, dd->dd_phys->dd_props_zapobj,
86 		    propname, intsz, numint, buf);
87 		if (err != ENOENT) {
88 			if (setpoint)
89 				dsl_dir_name(dd, setpoint);
90 			break;
91 		}
92 
93 		/*
94 		 * Break out of this loop for non-inheritable properties.
95 		 */
96 		if (prop != ZPROP_INVAL &&
97 		    !zfs_prop_inheritable(prop))
98 			break;
99 	}
100 	if (err == ENOENT)
101 		err = dodefault(propname, intsz, numint, buf);
102 
103 	return (err);
104 }
105 
106 /*
107  * Register interest in the named property.  We'll call the callback
108  * once to notify it of the current property value, and again each time
109  * the property changes, until this callback is unregistered.
110  *
111  * Return 0 on success, errno if the prop is not an integer value.
112  */
113 int
114 dsl_prop_register(dsl_dataset_t *ds, const char *propname,
115     dsl_prop_changed_cb_t *callback, void *cbarg)
116 {
117 	dsl_dir_t *dd = ds->ds_dir;
118 	uint64_t value;
119 	dsl_prop_cb_record_t *cbr;
120 	int err;
121 	int need_rwlock;
122 
123 	need_rwlock = !RW_WRITE_HELD(&dd->dd_pool->dp_config_rwlock);
124 	if (need_rwlock)
125 		rw_enter(&dd->dd_pool->dp_config_rwlock, RW_READER);
126 
127 	err = dsl_prop_get_impl(dd, propname, 8, 1, &value, NULL);
128 	if (err != 0) {
129 		rw_exit(&dd->dd_pool->dp_config_rwlock);
130 		return (err);
131 	}
132 
133 	cbr = kmem_alloc(sizeof (dsl_prop_cb_record_t), KM_SLEEP);
134 	cbr->cbr_ds = ds;
135 	cbr->cbr_propname = kmem_alloc(strlen(propname)+1, KM_SLEEP);
136 	(void) strcpy((char *)cbr->cbr_propname, propname);
137 	cbr->cbr_func = callback;
138 	cbr->cbr_arg = cbarg;
139 	mutex_enter(&dd->dd_lock);
140 	list_insert_head(&dd->dd_prop_cbs, cbr);
141 	mutex_exit(&dd->dd_lock);
142 
143 	cbr->cbr_func(cbr->cbr_arg, value);
144 
145 	VERIFY(0 == dsl_dir_open_obj(dd->dd_pool, dd->dd_object,
146 	    NULL, cbr, &dd));
147 	if (need_rwlock)
148 		rw_exit(&dd->dd_pool->dp_config_rwlock);
149 	/* Leave dataset open until this callback is unregistered */
150 	return (0);
151 }
152 
153 int
154 dsl_prop_get_ds(dsl_dir_t *dd, const char *propname,
155     int intsz, int numints, void *buf, char *setpoint)
156 {
157 	int err;
158 
159 	rw_enter(&dd->dd_pool->dp_config_rwlock, RW_READER);
160 	err = dsl_prop_get_impl(dd, propname, intsz, numints, buf, setpoint);
161 	rw_exit(&dd->dd_pool->dp_config_rwlock);
162 
163 	return (err);
164 }
165 
166 /*
167  * Get property when config lock is already held.
168  */
169 int dsl_prop_get_ds_locked(dsl_dir_t *dd, const char *propname,
170     int intsz, int numints, void *buf, char *setpoint)
171 {
172 	ASSERT(RW_LOCK_HELD(&dd->dd_pool->dp_config_rwlock));
173 	return (dsl_prop_get_impl(dd, propname, intsz, numints, buf, setpoint));
174 }
175 
176 int
177 dsl_prop_get(const char *ddname, const char *propname,
178     int intsz, int numints, void *buf, char *setpoint)
179 {
180 	dsl_dir_t *dd;
181 	const char *tail;
182 	int err;
183 
184 	err = dsl_dir_open(ddname, FTAG, &dd, &tail);
185 	if (err)
186 		return (err);
187 	if (tail && tail[0] != '@') {
188 		dsl_dir_close(dd, FTAG);
189 		return (ENOENT);
190 	}
191 
192 	err = dsl_prop_get_ds(dd, propname, intsz, numints, buf, setpoint);
193 
194 	dsl_dir_close(dd, FTAG);
195 	return (err);
196 }
197 
198 /*
199  * Get the current property value.  It may have changed by the time this
200  * function returns, so it is NOT safe to follow up with
201  * dsl_prop_register() and assume that the value has not changed in
202  * between.
203  *
204  * Return 0 on success, ENOENT if ddname is invalid.
205  */
206 int
207 dsl_prop_get_integer(const char *ddname, const char *propname,
208     uint64_t *valuep, char *setpoint)
209 {
210 	return (dsl_prop_get(ddname, propname, 8, 1, valuep, setpoint));
211 }
212 
213 /*
214  * Unregister this callback.  Return 0 on success, ENOENT if ddname is
215  * invalid, ENOMSG if no matching callback registered.
216  */
217 int
218 dsl_prop_unregister(dsl_dataset_t *ds, const char *propname,
219     dsl_prop_changed_cb_t *callback, void *cbarg)
220 {
221 	dsl_dir_t *dd = ds->ds_dir;
222 	dsl_prop_cb_record_t *cbr;
223 
224 	mutex_enter(&dd->dd_lock);
225 	for (cbr = list_head(&dd->dd_prop_cbs);
226 	    cbr; cbr = list_next(&dd->dd_prop_cbs, cbr)) {
227 		if (cbr->cbr_ds == ds &&
228 		    cbr->cbr_func == callback &&
229 		    cbr->cbr_arg == cbarg &&
230 		    strcmp(cbr->cbr_propname, propname) == 0)
231 			break;
232 	}
233 
234 	if (cbr == NULL) {
235 		mutex_exit(&dd->dd_lock);
236 		return (ENOMSG);
237 	}
238 
239 	list_remove(&dd->dd_prop_cbs, cbr);
240 	mutex_exit(&dd->dd_lock);
241 	kmem_free((void*)cbr->cbr_propname, strlen(cbr->cbr_propname)+1);
242 	kmem_free(cbr, sizeof (dsl_prop_cb_record_t));
243 
244 	/* Clean up from dsl_prop_register */
245 	dsl_dir_close(dd, cbr);
246 	return (0);
247 }
248 
249 /*
250  * Return the number of callbacks that are registered for this dataset.
251  */
252 int
253 dsl_prop_numcb(dsl_dataset_t *ds)
254 {
255 	dsl_dir_t *dd = ds->ds_dir;
256 	dsl_prop_cb_record_t *cbr;
257 	int num = 0;
258 
259 	mutex_enter(&dd->dd_lock);
260 	for (cbr = list_head(&dd->dd_prop_cbs);
261 	    cbr; cbr = list_next(&dd->dd_prop_cbs, cbr)) {
262 		if (cbr->cbr_ds == ds)
263 			num++;
264 	}
265 	mutex_exit(&dd->dd_lock);
266 
267 	return (num);
268 }
269 
270 static void
271 dsl_prop_changed_notify(dsl_pool_t *dp, uint64_t ddobj,
272     const char *propname, uint64_t value, int first)
273 {
274 	dsl_dir_t *dd;
275 	dsl_prop_cb_record_t *cbr;
276 	objset_t *mos = dp->dp_meta_objset;
277 	zap_cursor_t zc;
278 	zap_attribute_t za;
279 	int err;
280 
281 	ASSERT(RW_WRITE_HELD(&dp->dp_config_rwlock));
282 	err = dsl_dir_open_obj(dp, ddobj, NULL, FTAG, &dd);
283 	if (err)
284 		return;
285 
286 	if (!first) {
287 		/*
288 		 * If the prop is set here, then this change is not
289 		 * being inherited here or below; stop the recursion.
290 		 */
291 		err = zap_lookup(mos, dd->dd_phys->dd_props_zapobj, propname,
292 		    8, 1, &value);
293 		if (err == 0) {
294 			dsl_dir_close(dd, FTAG);
295 			return;
296 		}
297 		ASSERT3U(err, ==, ENOENT);
298 	}
299 
300 	mutex_enter(&dd->dd_lock);
301 	for (cbr = list_head(&dd->dd_prop_cbs);
302 	    cbr; cbr = list_next(&dd->dd_prop_cbs, cbr)) {
303 		if (strcmp(cbr->cbr_propname, propname) == 0) {
304 			cbr->cbr_func(cbr->cbr_arg, value);
305 		}
306 	}
307 	mutex_exit(&dd->dd_lock);
308 
309 	for (zap_cursor_init(&zc, mos,
310 	    dd->dd_phys->dd_child_dir_zapobj);
311 	    zap_cursor_retrieve(&zc, &za) == 0;
312 	    zap_cursor_advance(&zc)) {
313 		/* XXX recursion could blow stack; esp. za! */
314 		dsl_prop_changed_notify(dp, za.za_first_integer,
315 		    propname, value, FALSE);
316 	}
317 	zap_cursor_fini(&zc);
318 	dsl_dir_close(dd, FTAG);
319 }
320 
321 struct prop_set_arg {
322 	const char *name;
323 	int intsz;
324 	int numints;
325 	const void *buf;
326 };
327 
328 
329 static void
330 dsl_prop_set_sync(void *arg1, void *arg2, cred_t *cr, dmu_tx_t *tx)
331 {
332 	dsl_dir_t *dd = arg1;
333 	struct prop_set_arg *psa = arg2;
334 	objset_t *mos = dd->dd_pool->dp_meta_objset;
335 	uint64_t zapobj = dd->dd_phys->dd_props_zapobj;
336 	uint64_t intval;
337 	int isint;
338 	char valbuf[32];
339 	char *valstr;
340 
341 	isint = (dodefault(psa->name, 8, 1, &intval) == 0);
342 
343 	if (psa->numints == 0) {
344 		int err = zap_remove(mos, zapobj, psa->name, tx);
345 		ASSERT(err == 0 || err == ENOENT);
346 		if (isint) {
347 			VERIFY(0 == dsl_prop_get_impl(dd->dd_parent,
348 			    psa->name, 8, 1, &intval, NULL));
349 		}
350 	} else {
351 		VERIFY(0 == zap_update(mos, zapobj, psa->name,
352 		    psa->intsz, psa->numints, psa->buf, tx));
353 		if (isint)
354 			intval = *(uint64_t *)psa->buf;
355 	}
356 
357 	if (isint) {
358 		dsl_prop_changed_notify(dd->dd_pool,
359 		    dd->dd_object, psa->name, intval, TRUE);
360 	}
361 	if (isint) {
362 		(void) snprintf(valbuf, sizeof (valbuf),
363 		    "%lld", (longlong_t)intval);
364 		valstr = valbuf;
365 	} else {
366 		valstr = (char *)psa->buf;
367 	}
368 	spa_history_internal_log((psa->numints == 0) ? LOG_DS_INHERIT :
369 	    LOG_DS_PROPSET, dd->dd_pool->dp_spa, tx, cr,
370 	    "%s=%s dataset = %llu", psa->name, valstr,
371 	    dd->dd_phys->dd_head_dataset_obj);
372 }
373 
374 int
375 dsl_prop_set_dd(dsl_dir_t *dd, const char *propname,
376     int intsz, int numints, const void *buf)
377 {
378 	struct prop_set_arg psa;
379 
380 	psa.name = propname;
381 	psa.intsz = intsz;
382 	psa.numints = numints;
383 	psa.buf = buf;
384 
385 	return (dsl_sync_task_do(dd->dd_pool,
386 	    NULL, dsl_prop_set_sync, dd, &psa, 2));
387 }
388 
389 int
390 dsl_prop_set(const char *ddname, const char *propname,
391     int intsz, int numints, const void *buf)
392 {
393 	dsl_dir_t *dd;
394 	int err;
395 
396 	/*
397 	 * We must do these checks before we get to the syncfunc, since
398 	 * it can't fail.
399 	 */
400 	if (strlen(propname) >= ZAP_MAXNAMELEN)
401 		return (ENAMETOOLONG);
402 	if (intsz * numints >= ZAP_MAXVALUELEN)
403 		return (E2BIG);
404 
405 	err = dsl_dir_open(ddname, FTAG, &dd, NULL);
406 	if (err)
407 		return (err);
408 	err = dsl_prop_set_dd(dd, propname, intsz, numints, buf);
409 	dsl_dir_close(dd, FTAG);
410 	return (err);
411 }
412 
413 /*
414  * Iterate over all properties for this dataset and return them in an nvlist.
415  */
416 int
417 dsl_prop_get_all(objset_t *os, nvlist_t **nvp)
418 {
419 	dsl_dataset_t *ds = os->os->os_dsl_dataset;
420 	dsl_dir_t *dd = ds->ds_dir;
421 	int err = 0;
422 	dsl_pool_t *dp;
423 	objset_t *mos;
424 
425 	if (dsl_dataset_is_snapshot(ds)) {
426 		VERIFY(nvlist_alloc(nvp, NV_UNIQUE_NAME, KM_SLEEP) == 0);
427 		return (0);
428 	}
429 
430 	VERIFY(nvlist_alloc(nvp, NV_UNIQUE_NAME, KM_SLEEP) == 0);
431 
432 	dp = dd->dd_pool;
433 	mos = dp->dp_meta_objset;
434 
435 	rw_enter(&dp->dp_config_rwlock, RW_READER);
436 	for (; dd != NULL; dd = dd->dd_parent) {
437 		char setpoint[MAXNAMELEN];
438 		zap_cursor_t zc;
439 		zap_attribute_t za;
440 
441 		dsl_dir_name(dd, setpoint);
442 
443 		for (zap_cursor_init(&zc, mos, dd->dd_phys->dd_props_zapobj);
444 		    (err = zap_cursor_retrieve(&zc, &za)) == 0;
445 		    zap_cursor_advance(&zc)) {
446 			nvlist_t *propval;
447 			zfs_prop_t prop;
448 			/*
449 			 * Skip non-inheritable properties.
450 			 */
451 			if ((prop = zfs_name_to_prop(za.za_name)) !=
452 			    ZPROP_INVAL && !zfs_prop_inheritable(prop) &&
453 			    dd != ds->ds_dir)
454 				continue;
455 
456 			if (nvlist_lookup_nvlist(*nvp, za.za_name,
457 			    &propval) == 0)
458 				continue;
459 
460 			VERIFY(nvlist_alloc(&propval, NV_UNIQUE_NAME,
461 			    KM_SLEEP) == 0);
462 			if (za.za_integer_length == 1) {
463 				/*
464 				 * String property
465 				 */
466 				char *tmp = kmem_alloc(za.za_num_integers,
467 				    KM_SLEEP);
468 				err = zap_lookup(mos,
469 				    dd->dd_phys->dd_props_zapobj,
470 				    za.za_name, 1, za.za_num_integers,
471 				    tmp);
472 				if (err != 0) {
473 					kmem_free(tmp, za.za_num_integers);
474 					break;
475 				}
476 				VERIFY(nvlist_add_string(propval, ZPROP_VALUE,
477 				    tmp) == 0);
478 				kmem_free(tmp, za.za_num_integers);
479 			} else {
480 				/*
481 				 * Integer property
482 				 */
483 				ASSERT(za.za_integer_length == 8);
484 				(void) nvlist_add_uint64(propval, ZPROP_VALUE,
485 				    za.za_first_integer);
486 			}
487 
488 			VERIFY(nvlist_add_string(propval, ZPROP_SOURCE,
489 			    setpoint) == 0);
490 			VERIFY(nvlist_add_nvlist(*nvp, za.za_name,
491 			    propval) == 0);
492 			nvlist_free(propval);
493 		}
494 		zap_cursor_fini(&zc);
495 
496 		if (err != ENOENT)
497 			break;
498 		err = 0;
499 	}
500 	rw_exit(&dp->dp_config_rwlock);
501 
502 	return (err);
503 }
504 
505 void
506 dsl_prop_nvlist_add_uint64(nvlist_t *nv, zfs_prop_t prop, uint64_t value)
507 {
508 	nvlist_t *propval;
509 
510 	VERIFY(nvlist_alloc(&propval, NV_UNIQUE_NAME, KM_SLEEP) == 0);
511 	VERIFY(nvlist_add_uint64(propval, ZPROP_VALUE, value) == 0);
512 	VERIFY(nvlist_add_nvlist(nv, zfs_prop_to_name(prop), propval) == 0);
513 	nvlist_free(propval);
514 }
515 
516 void
517 dsl_prop_nvlist_add_string(nvlist_t *nv, zfs_prop_t prop, const char *value)
518 {
519 	nvlist_t *propval;
520 
521 	VERIFY(nvlist_alloc(&propval, NV_UNIQUE_NAME, KM_SLEEP) == 0);
522 	VERIFY(nvlist_add_string(propval, ZPROP_VALUE, value) == 0);
523 	VERIFY(nvlist_add_nvlist(nv, zfs_prop_to_name(prop), propval) == 0);
524 	nvlist_free(propval);
525 }
526