xref: /titanic_41/usr/src/uts/common/fs/zfs/dsl_prop.c (revision dfb96a4f56fb431b915bc67e5d9d5c8d4f4f6679)
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 2006 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)) == ZFS_PROP_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), numint);
55 	} else {
56 		if (intsz != 8 || numint < 1)
57 			return (EOVERFLOW);
58 
59 		*(uint64_t *)buf = zfs_prop_default_numeric(prop);
60 	}
61 
62 	return (0);
63 }
64 
65 static int
66 dsl_prop_get_impl(dsl_dir_t *dd, const char *propname,
67     int intsz, int numint, void *buf, char *setpoint)
68 {
69 	int err = ENOENT;
70 	zfs_prop_t prop;
71 
72 	if (setpoint)
73 		setpoint[0] = '\0';
74 
75 	prop = zfs_name_to_prop(propname);
76 
77 	/*
78 	 * Note: dd may be NULL, therefore we shouldn't dereference it
79 	 * ouside this loop.
80 	 */
81 	for (; dd != NULL; dd = dd->dd_parent) {
82 		objset_t *mos = dd->dd_pool->dp_meta_objset;
83 		ASSERT(RW_LOCK_HELD(&dd->dd_pool->dp_config_rwlock));
84 		err = zap_lookup(mos, dd->dd_phys->dd_props_zapobj,
85 		    propname, intsz, numint, buf);
86 		if (err != ENOENT) {
87 			if (setpoint)
88 				dsl_dir_name(dd, setpoint);
89 			break;
90 		}
91 
92 		/*
93 		 * Break out of this loop for non-inheritable properties.
94 		 */
95 		if (prop != ZFS_PROP_INVAL &&
96 		    !zfs_prop_inheritable(prop))
97 			break;
98 	}
99 	if (err == ENOENT)
100 		err = dodefault(propname, intsz, numint, buf);
101 
102 	return (err);
103 }
104 
105 /*
106  * Register interest in the named property.  We'll call the callback
107  * once to notify it of the current property value, and again each time
108  * the property changes, until this callback is unregistered.
109  *
110  * Return 0 on success, errno if the prop is not an integer value.
111  */
112 int
113 dsl_prop_register(dsl_dataset_t *ds, const char *propname,
114     dsl_prop_changed_cb_t *callback, void *cbarg)
115 {
116 	dsl_dir_t *dd = ds->ds_dir;
117 	uint64_t value;
118 	dsl_prop_cb_record_t *cbr;
119 	int err;
120 	int need_rwlock;
121 
122 	need_rwlock = !RW_WRITE_HELD(&dd->dd_pool->dp_config_rwlock);
123 	if (need_rwlock)
124 		rw_enter(&dd->dd_pool->dp_config_rwlock, RW_READER);
125 
126 	err = dsl_prop_get_impl(dd, propname, 8, 1, &value, NULL);
127 	if (err != 0) {
128 		rw_exit(&dd->dd_pool->dp_config_rwlock);
129 		return (err);
130 	}
131 
132 	cbr = kmem_alloc(sizeof (dsl_prop_cb_record_t), KM_SLEEP);
133 	cbr->cbr_ds = ds;
134 	cbr->cbr_propname = kmem_alloc(strlen(propname)+1, KM_SLEEP);
135 	(void) strcpy((char *)cbr->cbr_propname, propname);
136 	cbr->cbr_func = callback;
137 	cbr->cbr_arg = cbarg;
138 	mutex_enter(&dd->dd_lock);
139 	list_insert_head(&dd->dd_prop_cbs, cbr);
140 	mutex_exit(&dd->dd_lock);
141 
142 	cbr->cbr_func(cbr->cbr_arg, value);
143 
144 	VERIFY(0 == dsl_dir_open_obj(dd->dd_pool, dd->dd_object,
145 	    NULL, cbr, &dd));
146 	if (need_rwlock)
147 		rw_exit(&dd->dd_pool->dp_config_rwlock);
148 	/* Leave dataset open until this callback is unregistered */
149 	return (0);
150 }
151 
152 int
153 dsl_prop_get_ds(dsl_dir_t *dd, const char *propname,
154     int intsz, int numints, void *buf, char *setpoint)
155 {
156 	int err;
157 
158 	rw_enter(&dd->dd_pool->dp_config_rwlock, RW_READER);
159 	err = dsl_prop_get_impl(dd, propname, intsz, numints, buf, setpoint);
160 	rw_exit(&dd->dd_pool->dp_config_rwlock);
161 
162 	return (err);
163 }
164 
165 int
166 dsl_prop_get(const char *ddname, const char *propname,
167     int intsz, int numints, void *buf, char *setpoint)
168 {
169 	dsl_dir_t *dd;
170 	const char *tail;
171 	int err;
172 
173 	err = dsl_dir_open(ddname, FTAG, &dd, &tail);
174 	if (err)
175 		return (err);
176 	if (tail && tail[0] != '@') {
177 		dsl_dir_close(dd, FTAG);
178 		return (ENOENT);
179 	}
180 
181 	err = dsl_prop_get_ds(dd, propname, intsz, numints, buf, setpoint);
182 
183 	dsl_dir_close(dd, FTAG);
184 	return (err);
185 }
186 
187 /*
188  * Get the current property value.  It may have changed by the time this
189  * function returns, so it is NOT safe to follow up with
190  * dsl_prop_register() and assume that the value has not changed in
191  * between.
192  *
193  * Return 0 on success, ENOENT if ddname is invalid.
194  */
195 int
196 dsl_prop_get_integer(const char *ddname, const char *propname,
197     uint64_t *valuep, char *setpoint)
198 {
199 	return (dsl_prop_get(ddname, propname, 8, 1, valuep, setpoint));
200 }
201 
202 /*
203  * Unregister this callback.  Return 0 on success, ENOENT if ddname is
204  * invalid, ENOMSG if no matching callback registered.
205  */
206 int
207 dsl_prop_unregister(dsl_dataset_t *ds, const char *propname,
208     dsl_prop_changed_cb_t *callback, void *cbarg)
209 {
210 	dsl_dir_t *dd = ds->ds_dir;
211 	dsl_prop_cb_record_t *cbr;
212 
213 	mutex_enter(&dd->dd_lock);
214 	for (cbr = list_head(&dd->dd_prop_cbs);
215 	    cbr; cbr = list_next(&dd->dd_prop_cbs, cbr)) {
216 		if (cbr->cbr_ds == ds &&
217 		    cbr->cbr_func == callback &&
218 		    cbr->cbr_arg == cbarg &&
219 		    strcmp(cbr->cbr_propname, propname) == 0)
220 			break;
221 	}
222 
223 	if (cbr == NULL) {
224 		mutex_exit(&dd->dd_lock);
225 		return (ENOMSG);
226 	}
227 
228 	list_remove(&dd->dd_prop_cbs, cbr);
229 	mutex_exit(&dd->dd_lock);
230 	kmem_free((void*)cbr->cbr_propname, strlen(cbr->cbr_propname)+1);
231 	kmem_free(cbr, sizeof (dsl_prop_cb_record_t));
232 
233 	/* Clean up from dsl_prop_register */
234 	dsl_dir_close(dd, cbr);
235 	return (0);
236 }
237 
238 /*
239  * Return the number of callbacks that are registered for this dataset.
240  */
241 int
242 dsl_prop_numcb(dsl_dataset_t *ds)
243 {
244 	dsl_dir_t *dd = ds->ds_dir;
245 	dsl_prop_cb_record_t *cbr;
246 	int num = 0;
247 
248 	mutex_enter(&dd->dd_lock);
249 	for (cbr = list_head(&dd->dd_prop_cbs);
250 	    cbr; cbr = list_next(&dd->dd_prop_cbs, cbr)) {
251 		if (cbr->cbr_ds == ds)
252 			num++;
253 	}
254 	mutex_exit(&dd->dd_lock);
255 
256 	return (num);
257 }
258 
259 static void
260 dsl_prop_changed_notify(dsl_pool_t *dp, uint64_t ddobj,
261     const char *propname, uint64_t value, int first)
262 {
263 	dsl_dir_t *dd;
264 	dsl_prop_cb_record_t *cbr;
265 	objset_t *mos = dp->dp_meta_objset;
266 	zap_cursor_t zc;
267 	zap_attribute_t za;
268 	int err;
269 
270 	ASSERT(RW_WRITE_HELD(&dp->dp_config_rwlock));
271 	err = dsl_dir_open_obj(dp, ddobj, NULL, FTAG, &dd);
272 	if (err)
273 		return;
274 
275 	if (!first) {
276 		/*
277 		 * If the prop is set here, then this change is not
278 		 * being inherited here or below; stop the recursion.
279 		 */
280 		err = zap_lookup(mos, dd->dd_phys->dd_props_zapobj, propname,
281 		    8, 1, &value);
282 		if (err == 0) {
283 			dsl_dir_close(dd, FTAG);
284 			return;
285 		}
286 		ASSERT3U(err, ==, ENOENT);
287 	}
288 
289 	mutex_enter(&dd->dd_lock);
290 	for (cbr = list_head(&dd->dd_prop_cbs);
291 	    cbr; cbr = list_next(&dd->dd_prop_cbs, cbr)) {
292 		if (strcmp(cbr->cbr_propname, propname) == 0) {
293 			cbr->cbr_func(cbr->cbr_arg, value);
294 		}
295 	}
296 	mutex_exit(&dd->dd_lock);
297 
298 	for (zap_cursor_init(&zc, mos,
299 	    dd->dd_phys->dd_child_dir_zapobj);
300 	    zap_cursor_retrieve(&zc, &za) == 0;
301 	    zap_cursor_advance(&zc)) {
302 		/* XXX recursion could blow stack; esp. za! */
303 		dsl_prop_changed_notify(dp, za.za_first_integer,
304 		    propname, value, FALSE);
305 	}
306 	zap_cursor_fini(&zc);
307 	dsl_dir_close(dd, FTAG);
308 }
309 
310 struct prop_set_arg {
311 	const char *name;
312 	int intsz;
313 	int numints;
314 	const void *buf;
315 };
316 
317 
318 static void
319 dsl_prop_set_sync(void *arg1, void *arg2, dmu_tx_t *tx)
320 {
321 	dsl_dir_t *dd = arg1;
322 	struct prop_set_arg *psa = arg2;
323 	objset_t *mos = dd->dd_pool->dp_meta_objset;
324 	uint64_t zapobj = dd->dd_phys->dd_props_zapobj;
325 	uint64_t intval;
326 	int isint;
327 
328 	isint = (dodefault(psa->name, 8, 1, &intval) == 0);
329 
330 	if (psa->numints == 0) {
331 		int err = zap_remove(mos, zapobj, psa->name, tx);
332 		ASSERT(err == 0 || err == ENOENT);
333 		if (isint) {
334 			VERIFY(0 == dsl_prop_get_impl(dd->dd_parent,
335 			    psa->name, 8, 1, &intval, NULL));
336 		}
337 	} else {
338 		VERIFY(0 == zap_update(mos, zapobj, psa->name,
339 		    psa->intsz, psa->numints, psa->buf, tx));
340 		if (isint)
341 			intval = *(uint64_t *)psa->buf;
342 	}
343 
344 	if (isint) {
345 		dsl_prop_changed_notify(dd->dd_pool,
346 		    dd->dd_object, psa->name, intval, TRUE);
347 	}
348 }
349 
350 int
351 dsl_prop_set_dd(dsl_dir_t *dd, const char *propname,
352     int intsz, int numints, const void *buf)
353 {
354 	struct prop_set_arg psa;
355 
356 	psa.name = propname;
357 	psa.intsz = intsz;
358 	psa.numints = numints;
359 	psa.buf = buf;
360 
361 	return (dsl_sync_task_do(dd->dd_pool,
362 	    NULL, dsl_prop_set_sync, dd, &psa, 2));
363 }
364 
365 int
366 dsl_prop_set(const char *ddname, const char *propname,
367     int intsz, int numints, const void *buf)
368 {
369 	dsl_dir_t *dd;
370 	int err;
371 
372 	/*
373 	 * We must do these checks before we get to the syncfunc, since
374 	 * it can't fail.
375 	 */
376 	if (strlen(propname) >= ZAP_MAXNAMELEN)
377 		return (ENAMETOOLONG);
378 	if (intsz * numints >= ZAP_MAXVALUELEN)
379 		return (E2BIG);
380 
381 	err = dsl_dir_open(ddname, FTAG, &dd, NULL);
382 	if (err)
383 		return (err);
384 	err = dsl_prop_set_dd(dd, propname, intsz, numints, buf);
385 	dsl_dir_close(dd, FTAG);
386 	return (err);
387 }
388 
389 /*
390  * Iterate over all properties for this dataset and return them in an nvlist.
391  */
392 int
393 dsl_prop_get_all(objset_t *os, nvlist_t **nvp)
394 {
395 	dsl_dataset_t *ds = os->os->os_dsl_dataset;
396 	dsl_dir_t *dd = ds->ds_dir;
397 	int err = 0;
398 	dsl_pool_t *dp;
399 	objset_t *mos;
400 
401 	if (dsl_dataset_is_snapshot(ds)) {
402 		VERIFY(nvlist_alloc(nvp, NV_UNIQUE_NAME, KM_SLEEP) == 0);
403 		return (0);
404 	}
405 
406 	VERIFY(nvlist_alloc(nvp, NV_UNIQUE_NAME, KM_SLEEP) == 0);
407 
408 	dp = dd->dd_pool;
409 	mos = dp->dp_meta_objset;
410 
411 	rw_enter(&dp->dp_config_rwlock, RW_READER);
412 	for (; dd != NULL; dd = dd->dd_parent) {
413 		char setpoint[MAXNAMELEN];
414 		zap_cursor_t zc;
415 		zap_attribute_t za;
416 
417 		dsl_dir_name(dd, setpoint);
418 
419 		for (zap_cursor_init(&zc, mos, dd->dd_phys->dd_props_zapobj);
420 		    (err = zap_cursor_retrieve(&zc, &za)) == 0;
421 		    zap_cursor_advance(&zc)) {
422 			nvlist_t *propval;
423 			zfs_prop_t prop;
424 			/*
425 			 * Skip non-inheritable properties.
426 			 */
427 			if ((prop = zfs_name_to_prop(za.za_name)) !=
428 			    ZFS_PROP_INVAL && !zfs_prop_inheritable(prop) &&
429 			    dd != ds->ds_dir)
430 				continue;
431 
432 			if (nvlist_lookup_nvlist(*nvp, za.za_name,
433 			    &propval) == 0)
434 				continue;
435 
436 			VERIFY(nvlist_alloc(&propval, NV_UNIQUE_NAME,
437 			    KM_SLEEP) == 0);
438 			if (za.za_integer_length == 1) {
439 				/*
440 				 * String property
441 				 */
442 				char *tmp = kmem_alloc(za.za_num_integers,
443 				    KM_SLEEP);
444 				err = zap_lookup(mos,
445 				    dd->dd_phys->dd_props_zapobj,
446 				    za.za_name, 1, za.za_num_integers,
447 				    tmp);
448 				if (err != 0) {
449 					kmem_free(tmp, za.za_num_integers);
450 					break;
451 				}
452 				VERIFY(nvlist_add_string(propval,
453 				    ZFS_PROP_VALUE, tmp) == 0);
454 				kmem_free(tmp, za.za_num_integers);
455 			} else {
456 				/*
457 				 * Integer property
458 				 */
459 				ASSERT(za.za_integer_length == 8);
460 				(void) nvlist_add_uint64(propval,
461 				    ZFS_PROP_VALUE, za.za_first_integer);
462 			}
463 
464 			VERIFY(nvlist_add_string(propval,
465 			    ZFS_PROP_SOURCE, setpoint) == 0);
466 			VERIFY(nvlist_add_nvlist(*nvp, za.za_name,
467 			    propval) == 0);
468 			nvlist_free(propval);
469 		}
470 		zap_cursor_fini(&zc);
471 
472 		if (err != ENOENT)
473 			break;
474 		err = 0;
475 	}
476 	rw_exit(&dp->dp_config_rwlock);
477 
478 	return (err);
479 }
480 
481 void
482 dsl_prop_nvlist_add_uint64(nvlist_t *nv, zfs_prop_t prop, uint64_t value)
483 {
484 	nvlist_t *propval;
485 
486 	VERIFY(nvlist_alloc(&propval, NV_UNIQUE_NAME, KM_SLEEP) == 0);
487 	VERIFY(nvlist_add_uint64(propval, ZFS_PROP_VALUE, value) == 0);
488 	VERIFY(nvlist_add_nvlist(nv, zfs_prop_to_name(prop), propval) == 0);
489 	nvlist_free(propval);
490 }
491 
492 void
493 dsl_prop_nvlist_add_string(nvlist_t *nv, zfs_prop_t prop, const char *value)
494 {
495 	nvlist_t *propval;
496 
497 	VERIFY(nvlist_alloc(&propval, NV_UNIQUE_NAME, KM_SLEEP) == 0);
498 	VERIFY(nvlist_add_string(propval, ZFS_PROP_VALUE, value) == 0);
499 	VERIFY(nvlist_add_nvlist(nv, zfs_prop_to_name(prop), propval) == 0);
500 	nvlist_free(propval);
501 }
502