xref: /titanic_52/usr/src/uts/common/fs/zfs/dsl_prop.c (revision 41efec2219526a9b3ecce26f97aba761ef1e1d0d)
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)) == 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 /*
166  * Get property when config lock is already held.
167  */
168 int dsl_prop_get_ds_locked(dsl_dir_t *dd, const char *propname,
169     int intsz, int numints, void *buf, char *setpoint)
170 {
171 	ASSERT(RW_LOCK_HELD(&dd->dd_pool->dp_config_rwlock));
172 	return (dsl_prop_get_impl(dd, propname, intsz, numints, buf, setpoint));
173 }
174 
175 int
176 dsl_prop_get(const char *ddname, const char *propname,
177     int intsz, int numints, void *buf, char *setpoint)
178 {
179 	dsl_dir_t *dd;
180 	const char *tail;
181 	int err;
182 
183 	err = dsl_dir_open(ddname, FTAG, &dd, &tail);
184 	if (err)
185 		return (err);
186 	if (tail && tail[0] != '@') {
187 		dsl_dir_close(dd, FTAG);
188 		return (ENOENT);
189 	}
190 
191 	err = dsl_prop_get_ds(dd, propname, intsz, numints, buf, setpoint);
192 
193 	dsl_dir_close(dd, FTAG);
194 	return (err);
195 }
196 
197 /*
198  * Get the current property value.  It may have changed by the time this
199  * function returns, so it is NOT safe to follow up with
200  * dsl_prop_register() and assume that the value has not changed in
201  * between.
202  *
203  * Return 0 on success, ENOENT if ddname is invalid.
204  */
205 int
206 dsl_prop_get_integer(const char *ddname, const char *propname,
207     uint64_t *valuep, char *setpoint)
208 {
209 	return (dsl_prop_get(ddname, propname, 8, 1, valuep, setpoint));
210 }
211 
212 /*
213  * Unregister this callback.  Return 0 on success, ENOENT if ddname is
214  * invalid, ENOMSG if no matching callback registered.
215  */
216 int
217 dsl_prop_unregister(dsl_dataset_t *ds, const char *propname,
218     dsl_prop_changed_cb_t *callback, void *cbarg)
219 {
220 	dsl_dir_t *dd = ds->ds_dir;
221 	dsl_prop_cb_record_t *cbr;
222 
223 	mutex_enter(&dd->dd_lock);
224 	for (cbr = list_head(&dd->dd_prop_cbs);
225 	    cbr; cbr = list_next(&dd->dd_prop_cbs, cbr)) {
226 		if (cbr->cbr_ds == ds &&
227 		    cbr->cbr_func == callback &&
228 		    cbr->cbr_arg == cbarg &&
229 		    strcmp(cbr->cbr_propname, propname) == 0)
230 			break;
231 	}
232 
233 	if (cbr == NULL) {
234 		mutex_exit(&dd->dd_lock);
235 		return (ENOMSG);
236 	}
237 
238 	list_remove(&dd->dd_prop_cbs, cbr);
239 	mutex_exit(&dd->dd_lock);
240 	kmem_free((void*)cbr->cbr_propname, strlen(cbr->cbr_propname)+1);
241 	kmem_free(cbr, sizeof (dsl_prop_cb_record_t));
242 
243 	/* Clean up from dsl_prop_register */
244 	dsl_dir_close(dd, cbr);
245 	return (0);
246 }
247 
248 /*
249  * Return the number of callbacks that are registered for this dataset.
250  */
251 int
252 dsl_prop_numcb(dsl_dataset_t *ds)
253 {
254 	dsl_dir_t *dd = ds->ds_dir;
255 	dsl_prop_cb_record_t *cbr;
256 	int num = 0;
257 
258 	mutex_enter(&dd->dd_lock);
259 	for (cbr = list_head(&dd->dd_prop_cbs);
260 	    cbr; cbr = list_next(&dd->dd_prop_cbs, cbr)) {
261 		if (cbr->cbr_ds == ds)
262 			num++;
263 	}
264 	mutex_exit(&dd->dd_lock);
265 
266 	return (num);
267 }
268 
269 static void
270 dsl_prop_changed_notify(dsl_pool_t *dp, uint64_t ddobj,
271     const char *propname, uint64_t value, int first)
272 {
273 	dsl_dir_t *dd;
274 	dsl_prop_cb_record_t *cbr;
275 	objset_t *mos = dp->dp_meta_objset;
276 	zap_cursor_t zc;
277 	zap_attribute_t za;
278 	int err;
279 
280 	ASSERT(RW_WRITE_HELD(&dp->dp_config_rwlock));
281 	err = dsl_dir_open_obj(dp, ddobj, NULL, FTAG, &dd);
282 	if (err)
283 		return;
284 
285 	if (!first) {
286 		/*
287 		 * If the prop is set here, then this change is not
288 		 * being inherited here or below; stop the recursion.
289 		 */
290 		err = zap_lookup(mos, dd->dd_phys->dd_props_zapobj, propname,
291 		    8, 1, &value);
292 		if (err == 0) {
293 			dsl_dir_close(dd, FTAG);
294 			return;
295 		}
296 		ASSERT3U(err, ==, ENOENT);
297 	}
298 
299 	mutex_enter(&dd->dd_lock);
300 	for (cbr = list_head(&dd->dd_prop_cbs);
301 	    cbr; cbr = list_next(&dd->dd_prop_cbs, cbr)) {
302 		if (strcmp(cbr->cbr_propname, propname) == 0) {
303 			cbr->cbr_func(cbr->cbr_arg, value);
304 		}
305 	}
306 	mutex_exit(&dd->dd_lock);
307 
308 	for (zap_cursor_init(&zc, mos,
309 	    dd->dd_phys->dd_child_dir_zapobj);
310 	    zap_cursor_retrieve(&zc, &za) == 0;
311 	    zap_cursor_advance(&zc)) {
312 		/* XXX recursion could blow stack; esp. za! */
313 		dsl_prop_changed_notify(dp, za.za_first_integer,
314 		    propname, value, FALSE);
315 	}
316 	zap_cursor_fini(&zc);
317 	dsl_dir_close(dd, FTAG);
318 }
319 
320 struct prop_set_arg {
321 	const char *name;
322 	int intsz;
323 	int numints;
324 	const void *buf;
325 };
326 
327 
328 static void
329 dsl_prop_set_sync(void *arg1, void *arg2, cred_t *cr, dmu_tx_t *tx)
330 {
331 	dsl_dir_t *dd = arg1;
332 	struct prop_set_arg *psa = arg2;
333 	objset_t *mos = dd->dd_pool->dp_meta_objset;
334 	uint64_t zapobj = dd->dd_phys->dd_props_zapobj;
335 	uint64_t intval;
336 	int isint;
337 	char valbuf[32];
338 	char *valstr;
339 
340 	isint = (dodefault(psa->name, 8, 1, &intval) == 0);
341 
342 	if (psa->numints == 0) {
343 		int err = zap_remove(mos, zapobj, psa->name, tx);
344 		ASSERT(err == 0 || err == ENOENT);
345 		if (isint) {
346 			VERIFY(0 == dsl_prop_get_impl(dd->dd_parent,
347 			    psa->name, 8, 1, &intval, NULL));
348 		}
349 	} else {
350 		VERIFY(0 == zap_update(mos, zapobj, psa->name,
351 		    psa->intsz, psa->numints, psa->buf, tx));
352 		if (isint)
353 			intval = *(uint64_t *)psa->buf;
354 	}
355 
356 	if (isint) {
357 		dsl_prop_changed_notify(dd->dd_pool,
358 		    dd->dd_object, psa->name, intval, TRUE);
359 	}
360 	if (isint) {
361 		(void) snprintf(valbuf, sizeof (valbuf),
362 		    "%lld", (longlong_t)intval);
363 		valstr = valbuf;
364 	} else {
365 		valstr = (char *)psa->buf;
366 	}
367 	spa_history_internal_log((psa->numints == 0) ? LOG_DS_INHERIT :
368 	    LOG_DS_PROPSET, dd->dd_pool->dp_spa, tx, cr,
369 	    "%s=%s dataset = %llu", psa->name, valstr,
370 	    dd->dd_phys->dd_head_dataset_obj);
371 }
372 
373 int
374 dsl_prop_set_dd(dsl_dir_t *dd, const char *propname,
375     int intsz, int numints, const void *buf)
376 {
377 	struct prop_set_arg psa;
378 
379 	psa.name = propname;
380 	psa.intsz = intsz;
381 	psa.numints = numints;
382 	psa.buf = buf;
383 
384 	return (dsl_sync_task_do(dd->dd_pool,
385 	    NULL, dsl_prop_set_sync, dd, &psa, 2));
386 }
387 
388 int
389 dsl_prop_set(const char *ddname, const char *propname,
390     int intsz, int numints, const void *buf)
391 {
392 	dsl_dir_t *dd;
393 	int err;
394 
395 	/*
396 	 * We must do these checks before we get to the syncfunc, since
397 	 * it can't fail.
398 	 */
399 	if (strlen(propname) >= ZAP_MAXNAMELEN)
400 		return (ENAMETOOLONG);
401 	if (intsz * numints >= ZAP_MAXVALUELEN)
402 		return (E2BIG);
403 
404 	err = dsl_dir_open(ddname, FTAG, &dd, NULL);
405 	if (err)
406 		return (err);
407 	err = dsl_prop_set_dd(dd, propname, intsz, numints, buf);
408 	dsl_dir_close(dd, FTAG);
409 	return (err);
410 }
411 
412 /*
413  * Iterate over all properties for this dataset and return them in an nvlist.
414  */
415 int
416 dsl_prop_get_all(objset_t *os, nvlist_t **nvp)
417 {
418 	dsl_dataset_t *ds = os->os->os_dsl_dataset;
419 	dsl_dir_t *dd = ds->ds_dir;
420 	int err = 0;
421 	dsl_pool_t *dp;
422 	objset_t *mos;
423 
424 	if (dsl_dataset_is_snapshot(ds)) {
425 		VERIFY(nvlist_alloc(nvp, NV_UNIQUE_NAME, KM_SLEEP) == 0);
426 		return (0);
427 	}
428 
429 	VERIFY(nvlist_alloc(nvp, NV_UNIQUE_NAME, KM_SLEEP) == 0);
430 
431 	dp = dd->dd_pool;
432 	mos = dp->dp_meta_objset;
433 
434 	rw_enter(&dp->dp_config_rwlock, RW_READER);
435 	for (; dd != NULL; dd = dd->dd_parent) {
436 		char setpoint[MAXNAMELEN];
437 		zap_cursor_t zc;
438 		zap_attribute_t za;
439 
440 		dsl_dir_name(dd, setpoint);
441 
442 		for (zap_cursor_init(&zc, mos, dd->dd_phys->dd_props_zapobj);
443 		    (err = zap_cursor_retrieve(&zc, &za)) == 0;
444 		    zap_cursor_advance(&zc)) {
445 			nvlist_t *propval;
446 			zfs_prop_t prop;
447 			/*
448 			 * Skip non-inheritable properties.
449 			 */
450 			if ((prop = zfs_name_to_prop(za.za_name)) !=
451 			    ZFS_PROP_INVAL && !zfs_prop_inheritable(prop) &&
452 			    dd != ds->ds_dir)
453 				continue;
454 
455 			if (nvlist_lookup_nvlist(*nvp, za.za_name,
456 			    &propval) == 0)
457 				continue;
458 
459 			VERIFY(nvlist_alloc(&propval, NV_UNIQUE_NAME,
460 			    KM_SLEEP) == 0);
461 			if (za.za_integer_length == 1) {
462 				/*
463 				 * String property
464 				 */
465 				char *tmp = kmem_alloc(za.za_num_integers,
466 				    KM_SLEEP);
467 				err = zap_lookup(mos,
468 				    dd->dd_phys->dd_props_zapobj,
469 				    za.za_name, 1, za.za_num_integers,
470 				    tmp);
471 				if (err != 0) {
472 					kmem_free(tmp, za.za_num_integers);
473 					break;
474 				}
475 				VERIFY(nvlist_add_string(propval,
476 				    ZFS_PROP_VALUE, tmp) == 0);
477 				kmem_free(tmp, za.za_num_integers);
478 			} else {
479 				/*
480 				 * Integer property
481 				 */
482 				ASSERT(za.za_integer_length == 8);
483 				(void) nvlist_add_uint64(propval,
484 				    ZFS_PROP_VALUE, za.za_first_integer);
485 			}
486 
487 			VERIFY(nvlist_add_string(propval,
488 			    ZFS_PROP_SOURCE, setpoint) == 0);
489 			VERIFY(nvlist_add_nvlist(*nvp, za.za_name,
490 			    propval) == 0);
491 			nvlist_free(propval);
492 		}
493 		zap_cursor_fini(&zc);
494 
495 		if (err != ENOENT)
496 			break;
497 		err = 0;
498 	}
499 	rw_exit(&dp->dp_config_rwlock);
500 
501 	return (err);
502 }
503 
504 void
505 dsl_prop_nvlist_add_uint64(nvlist_t *nv, zfs_prop_t prop, uint64_t value)
506 {
507 	nvlist_t *propval;
508 
509 	VERIFY(nvlist_alloc(&propval, NV_UNIQUE_NAME, KM_SLEEP) == 0);
510 	VERIFY(nvlist_add_uint64(propval, ZFS_PROP_VALUE, value) == 0);
511 	VERIFY(nvlist_add_nvlist(nv, zfs_prop_to_name(prop), propval) == 0);
512 	nvlist_free(propval);
513 }
514 
515 void
516 dsl_prop_nvlist_add_string(nvlist_t *nv, zfs_prop_t prop, const char *value)
517 {
518 	nvlist_t *propval;
519 
520 	VERIFY(nvlist_alloc(&propval, NV_UNIQUE_NAME, KM_SLEEP) == 0);
521 	VERIFY(nvlist_add_string(propval, ZFS_PROP_VALUE, value) == 0);
522 	VERIFY(nvlist_add_nvlist(nv, zfs_prop_to_name(prop), propval) == 0);
523 	nvlist_free(propval);
524 }
525