xref: /titanic_41/usr/src/uts/common/fs/zfs/dsl_prop.c (revision 5aefb6555731130ca4fd295960123d71f2d21fe8)
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/spa.h>
35 #include <sys/zio_checksum.h> /* for the default checksum value */
36 #include <sys/zap.h>
37 #include <sys/fs/zfs.h>
38 
39 #include "zfs_prop.h"
40 
41 static int
42 dodefault(const char *propname, int intsz, int numint, void *buf)
43 {
44 	zfs_prop_t prop;
45 
46 	if ((prop = zfs_name_to_prop(propname)) == ZFS_PROP_INVAL ||
47 	    zfs_prop_readonly(prop))
48 		return (ENOENT);
49 
50 	if (zfs_prop_get_type(prop) == prop_type_string) {
51 		if (intsz != 1)
52 			return (EOVERFLOW);
53 		(void) strncpy(buf, zfs_prop_default_string(prop), numint);
54 	} else {
55 		if (intsz != 8 || numint < 1)
56 			return (EOVERFLOW);
57 
58 		*(uint64_t *)buf = zfs_prop_default_numeric(prop);
59 	}
60 
61 	return (0);
62 }
63 
64 static int
65 dsl_prop_get_impl(dsl_pool_t *dp, uint64_t ddobj, const char *propname,
66     int intsz, int numint, void *buf, char *setpoint)
67 {
68 	int err = 0;
69 	objset_t *mos = dp->dp_meta_objset;
70 
71 	if (setpoint)
72 		setpoint[0] = '\0';
73 
74 	ASSERT(RW_LOCK_HELD(&dp->dp_config_rwlock));
75 
76 	while (ddobj != 0) {
77 		dsl_dir_t *dd;
78 		err = dsl_dir_open_obj(dp, ddobj, NULL, FTAG, &dd);
79 		if (err)
80 			break;
81 		err = zap_lookup(mos, dd->dd_phys->dd_props_zapobj,
82 		    propname, intsz, numint, buf);
83 		if (err != ENOENT) {
84 			if (setpoint)
85 				dsl_dir_name(dd, setpoint);
86 			dsl_dir_close(dd, FTAG);
87 			break;
88 		}
89 		ASSERT3U(err, ==, ENOENT);
90 		ddobj = dd->dd_phys->dd_parent_obj;
91 		dsl_dir_close(dd, FTAG);
92 	}
93 	if (err == ENOENT)
94 		err = dodefault(propname, intsz, numint, buf);
95 
96 	return (err);
97 }
98 
99 /*
100  * Register interest in the named property.  We'll call the callback
101  * once to notify it of the current property value, and again each time
102  * the property changes, until this callback is unregistered.
103  *
104  * Return 0 on success, errno if the prop is not an integer value.
105  */
106 int
107 dsl_prop_register(dsl_dataset_t *ds, const char *propname,
108     dsl_prop_changed_cb_t *callback, void *cbarg)
109 {
110 	dsl_dir_t *dd;
111 	uint64_t value;
112 	dsl_prop_cb_record_t *cbr;
113 	int err;
114 
115 	dd = ds->ds_dir;
116 
117 	rw_enter(&dd->dd_pool->dp_config_rwlock, RW_READER);
118 
119 	err = dsl_prop_get_impl(dd->dd_pool, dd->dd_object, propname,
120 	    8, 1, &value, NULL);
121 	if (err == ENOENT) {
122 		err = 0;
123 		value = DSL_PROP_VALUE_UNDEFINED;
124 	}
125 	if (err != 0) {
126 		rw_exit(&dd->dd_pool->dp_config_rwlock);
127 		return (err);
128 	}
129 
130 	cbr = kmem_alloc(sizeof (dsl_prop_cb_record_t), KM_SLEEP);
131 	cbr->cbr_propname = kmem_alloc(strlen(propname)+1, KM_SLEEP);
132 	(void) strcpy((char *)cbr->cbr_propname, propname);
133 	cbr->cbr_func = callback;
134 	cbr->cbr_arg = cbarg;
135 	mutex_enter(&dd->dd_lock);
136 	list_insert_head(&dd->dd_prop_cbs, cbr);
137 	mutex_exit(&dd->dd_lock);
138 
139 	cbr->cbr_func(cbr->cbr_arg, value);
140 
141 	VERIFY(0 == dsl_dir_open_obj(dd->dd_pool, dd->dd_object,
142 	    NULL, cbr, &dd));
143 	rw_exit(&dd->dd_pool->dp_config_rwlock);
144 	/* Leave dataset open until this callback is unregistered */
145 	return (0);
146 }
147 
148 int
149 dsl_prop_get_ds(dsl_dir_t *dd, const char *propname,
150     int intsz, int numints, void *buf, char *setpoint)
151 {
152 	int err;
153 
154 	rw_enter(&dd->dd_pool->dp_config_rwlock, RW_READER);
155 	err = dsl_prop_get_impl(dd->dd_pool, dd->dd_object,
156 	    propname, intsz, numints, buf, setpoint);
157 	rw_exit(&dd->dd_pool->dp_config_rwlock);
158 
159 	return (err);
160 }
161 
162 int
163 dsl_prop_get(const char *ddname, const char *propname,
164     int intsz, int numints, void *buf, char *setpoint)
165 {
166 	dsl_dir_t *dd;
167 	const char *tail;
168 	int err;
169 
170 	err = dsl_dir_open(ddname, FTAG, &dd, &tail);
171 	if (err)
172 		return (err);
173 	if (tail && tail[0] != '@') {
174 		dsl_dir_close(dd, FTAG);
175 		return (ENOENT);
176 	}
177 
178 	err = dsl_prop_get_ds(dd, propname, intsz, numints, buf, setpoint);
179 
180 	dsl_dir_close(dd, FTAG);
181 	return (err);
182 }
183 
184 /*
185  * Return 0 on success, ENOENT if ddname is invalid, EOVERFLOW if
186  * valuelen not big enough.
187  */
188 int
189 dsl_prop_get_string(const char *ddname, const char *propname,
190     char *value, int valuelen, char *setpoint)
191 {
192 	return (dsl_prop_get(ddname, propname, 1, valuelen, value, setpoint));
193 }
194 
195 /*
196  * Get the current property value.  It may have changed by the time this
197  * function returns, so it is NOT safe to follow up with
198  * dsl_prop_register() and assume that the value has not changed in
199  * between.
200  *
201  * Return 0 on success, ENOENT if ddname is invalid.
202  */
203 int
204 dsl_prop_get_integer(const char *ddname, const char *propname,
205     uint64_t *valuep, char *setpoint)
206 {
207 	return (dsl_prop_get(ddname, propname, 8, 1, valuep, setpoint));
208 }
209 
210 int
211 dsl_prop_get_ds_integer(dsl_dir_t *dd, const char *propname,
212     uint64_t *valuep, char *setpoint)
213 {
214 	return (dsl_prop_get_ds(dd, propname, 8, 1, valuep, setpoint));
215 }
216 
217 /*
218  * Unregister this callback.  Return 0 on success, ENOENT if ddname is
219  * invalid, ENOMSG if no matching callback registered.
220  */
221 int
222 dsl_prop_unregister(dsl_dataset_t *ds, const char *propname,
223     dsl_prop_changed_cb_t *callback, void *cbarg)
224 {
225 	dsl_dir_t *dd;
226 	dsl_prop_cb_record_t *cbr;
227 
228 	dd = ds->ds_dir;
229 
230 	mutex_enter(&dd->dd_lock);
231 	for (cbr = list_head(&dd->dd_prop_cbs);
232 	    cbr; cbr = list_next(&dd->dd_prop_cbs, cbr)) {
233 		if (strcmp(cbr->cbr_propname, propname) == 0 &&
234 		    cbr->cbr_func == callback &&
235 		    cbr->cbr_arg == cbarg)
236 			break;
237 	}
238 
239 	if (cbr == NULL) {
240 		mutex_exit(&dd->dd_lock);
241 		return (ENOMSG);
242 	}
243 
244 	list_remove(&dd->dd_prop_cbs, cbr);
245 	mutex_exit(&dd->dd_lock);
246 	kmem_free((void*)cbr->cbr_propname, strlen(cbr->cbr_propname)+1);
247 	kmem_free(cbr, sizeof (dsl_prop_cb_record_t));
248 
249 	/* Clean up from dsl_prop_register */
250 	dsl_dir_close(dd, cbr);
251 	return (0);
252 }
253 
254 static void
255 dsl_prop_changed_notify(dsl_pool_t *dp, uint64_t ddobj,
256     const char *propname, uint64_t value, int first)
257 {
258 	dsl_dir_t *dd;
259 	dsl_prop_cb_record_t *cbr;
260 	objset_t *mos = dp->dp_meta_objset;
261 	int err;
262 
263 	ASSERT(RW_WRITE_HELD(&dp->dp_config_rwlock));
264 	err = dsl_dir_open_obj(dp, ddobj, NULL, FTAG, &dd);
265 	if (err)
266 		return;
267 
268 	if (!first) {
269 		/*
270 		 * If the prop is set here, then this change is not
271 		 * being inherited here or below; stop the recursion.
272 		 */
273 		err = zap_lookup(mos, dd->dd_phys->dd_props_zapobj, propname,
274 		    8, 1, &value);
275 		if (err == 0) {
276 			dsl_dir_close(dd, FTAG);
277 			return;
278 		}
279 		ASSERT3U(err, ==, ENOENT);
280 	}
281 
282 	mutex_enter(&dd->dd_lock);
283 	for (cbr = list_head(&dd->dd_prop_cbs);
284 	    cbr; cbr = list_next(&dd->dd_prop_cbs, cbr)) {
285 		if (strcmp(cbr->cbr_propname, propname) == 0) {
286 			cbr->cbr_func(cbr->cbr_arg, value);
287 		}
288 	}
289 	mutex_exit(&dd->dd_lock);
290 
291 	if (dd->dd_phys->dd_child_dir_zapobj) {
292 		zap_cursor_t zc;
293 		zap_attribute_t za;
294 
295 		for (zap_cursor_init(&zc, mos,
296 		    dd->dd_phys->dd_child_dir_zapobj);
297 		    zap_cursor_retrieve(&zc, &za) == 0;
298 		    zap_cursor_advance(&zc)) {
299 			/* XXX recursion could blow stack; esp. za! */
300 			dsl_prop_changed_notify(dp, za.za_first_integer,
301 			    propname, value, FALSE);
302 		}
303 		zap_cursor_fini(&zc);
304 	}
305 	dsl_dir_close(dd, FTAG);
306 }
307 
308 struct prop_set_arg {
309 	const char *name;
310 	int intsz;
311 	int numints;
312 	const void *buf;
313 };
314 
315 static int
316 dsl_prop_set_sync(dsl_dir_t *dd, void *arg, dmu_tx_t *tx)
317 {
318 	struct prop_set_arg *psa = arg;
319 	objset_t *mos = dd->dd_pool->dp_meta_objset;
320 	uint64_t zapobj = dd->dd_phys->dd_props_zapobj;
321 	uint64_t intval;
322 	int err, isint;
323 
324 	rw_enter(&dd->dd_pool->dp_config_rwlock, RW_WRITER);
325 
326 	isint = (dodefault(psa->name, 8, 1, &intval) == 0);
327 
328 	if (psa->numints == 0) {
329 		err = zap_remove(mos, zapobj, psa->name, tx);
330 		if (err == ENOENT) /* that's fine. */
331 			err = 0;
332 		if (err == 0 && isint) {
333 			err = dsl_prop_get_impl(dd->dd_pool,
334 			    dd->dd_phys->dd_parent_obj, psa->name,
335 			    8, 1, &intval, NULL);
336 		}
337 	} else {
338 		err = 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 (err == 0 && isint) {
345 		dsl_prop_changed_notify(dd->dd_pool,
346 		    dd->dd_object, psa->name, intval, TRUE);
347 	}
348 	rw_exit(&dd->dd_pool->dp_config_rwlock);
349 
350 	return (err);
351 }
352 
353 int
354 dsl_prop_set(const char *ddname, const char *propname,
355     int intsz, int numints, const void *buf)
356 {
357 	dsl_dir_t *dd;
358 	int err;
359 	struct prop_set_arg psa;
360 
361 	err = dsl_dir_open(ddname, FTAG, &dd, NULL);
362 	if (err)
363 		return (err);
364 
365 	psa.name = propname;
366 	psa.intsz = intsz;
367 	psa.numints = numints;
368 	psa.buf = buf;
369 	err = dsl_dir_sync_task(dd, dsl_prop_set_sync, &psa, 1<<20);
370 
371 	dsl_dir_close(dd, FTAG);
372 
373 	return (err);
374 }
375 
376 /*
377  * Iterate over all properties for this dataset and return them in an nvlist.
378  */
379 int
380 dsl_prop_get_all(objset_t *os, nvlist_t **nvp)
381 {
382 	dsl_dataset_t *ds = os->os->os_dsl_dataset;
383 	dsl_dir_t *dd, *parent;
384 	int err = 0;
385 	dsl_pool_t *dp;
386 	objset_t *mos;
387 	zap_cursor_t zc;
388 	zap_attribute_t za;
389 	char setpoint[MAXNAMELEN];
390 	char *tmp;
391 	nvlist_t *prop;
392 
393 	if (dsl_dataset_is_snapshot(ds)) {
394 		VERIFY(nvlist_alloc(nvp, NV_UNIQUE_NAME, KM_SLEEP) == 0);
395 		return (0);
396 	}
397 
398 	dd = ds->ds_dir;
399 
400 	VERIFY(nvlist_alloc(nvp, NV_UNIQUE_NAME, KM_SLEEP) == 0);
401 
402 	dp = dd->dd_pool;
403 	mos = dp->dp_meta_objset;
404 
405 	rw_enter(&dp->dp_config_rwlock, RW_READER);
406 	while (dd != NULL) {
407 		dsl_dir_name(dd, setpoint);
408 
409 		for (zap_cursor_init(&zc, mos, dd->dd_phys->dd_props_zapobj);
410 		    (err = zap_cursor_retrieve(&zc, &za)) == 0;
411 		    zap_cursor_advance(&zc)) {
412 			if (nvlist_lookup_nvlist(*nvp, za.za_name, &prop) == 0)
413 				continue;
414 
415 			VERIFY(nvlist_alloc(&prop, NV_UNIQUE_NAME,
416 			    KM_SLEEP) == 0);
417 			if (za.za_integer_length == 1) {
418 				/*
419 				 * String property
420 				 */
421 
422 				tmp = kmem_alloc(za.za_num_integers, KM_SLEEP);
423 				err = zap_lookup(mos,
424 				    dd->dd_phys->dd_props_zapobj,
425 				    za.za_name, 1, za.za_num_integers,
426 				    tmp);
427 				if (err != 0) {
428 					kmem_free(tmp, za.za_num_integers);
429 					break;
430 				}
431 				VERIFY(nvlist_add_string(prop,
432 				    ZFS_PROP_VALUE, tmp) == 0);
433 				kmem_free(tmp, za.za_num_integers);
434 			} else {
435 				/*
436 				 * Integer property
437 				 */
438 				ASSERT(za.za_integer_length == 8);
439 				(void) nvlist_add_uint64(prop, ZFS_PROP_VALUE,
440 				    za.za_first_integer);
441 			}
442 
443 			VERIFY(nvlist_add_string(prop,
444 			    ZFS_PROP_SOURCE, setpoint) == 0);
445 			VERIFY(nvlist_add_nvlist(*nvp, za.za_name,
446 			    prop) == 0);
447 			nvlist_free(prop);
448 		}
449 		zap_cursor_fini(&zc);
450 
451 		if (err != ENOENT) {
452 			if (dd != ds->ds_dir)
453 				dsl_dir_close(dd, FTAG);
454 			break;
455 		} else {
456 			err = 0;
457 		}
458 
459 		/*
460 		 * Continue to parent.
461 		 */
462 		if (dd->dd_phys->dd_parent_obj == 0)
463 			parent = NULL;
464 		else
465 			err = dsl_dir_open_obj(dp,
466 			    dd->dd_phys->dd_parent_obj, NULL, FTAG, &parent);
467 		if (dd != ds->ds_dir)
468 			dsl_dir_close(dd, FTAG);
469 		if (err)
470 			break;
471 		dd = parent;
472 	}
473 	rw_exit(&dp->dp_config_rwlock);
474 
475 	return (err);
476 }
477