xref: /titanic_44/usr/src/uts/common/fs/zfs/dsl_prop.c (revision 28167c24ba5be8b7c1d05e02d053f4a55cd21cc9)
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, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*
23  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #pragma ident	"%Z%%M%	%I%	%E% SMI"
28 
29 #include <sys/dmu.h>
30 #include <sys/dmu_objset.h>
31 #include <sys/dmu_tx.h>
32 #include <sys/dsl_dataset.h>
33 #include <sys/dsl_dir.h>
34 #include <sys/dsl_prop.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_pool_t *dp, uint64_t ddobj, const char *propname,
67     int intsz, int numint, void *buf, char *setpoint)
68 {
69 	int err = 0;
70 	objset_t *mos = dp->dp_meta_objset;
71 
72 	if (setpoint)
73 		setpoint[0] = '\0';
74 
75 	ASSERT(RW_LOCK_HELD(&dp->dp_config_rwlock));
76 
77 	while (ddobj != 0) {
78 		dsl_dir_t *dd = dsl_dir_open_obj(dp, ddobj, NULL, FTAG);
79 		err = zap_lookup(mos, dd->dd_phys->dd_props_zapobj,
80 		    propname, intsz, numint, buf);
81 		if (err != ENOENT) {
82 			if (setpoint)
83 				dsl_dir_name(dd, setpoint);
84 			dsl_dir_close(dd, FTAG);
85 			break;
86 		}
87 		ASSERT3U(err, ==, ENOENT);
88 		ddobj = dd->dd_phys->dd_parent_obj;
89 		dsl_dir_close(dd, FTAG);
90 	}
91 	if (err == ENOENT)
92 		err = dodefault(propname, intsz, numint, buf);
93 
94 	return (err);
95 }
96 
97 /*
98  * Register interest in the named property.  We'll call the callback
99  * once to notify it of the current property value, and again each time
100  * the property changes, until this callback is unregistered.
101  *
102  * Return 0 on success, errno if the prop is not an integer value.
103  */
104 int
105 dsl_prop_register(dsl_dataset_t *ds, const char *propname,
106     dsl_prop_changed_cb_t *callback, void *cbarg)
107 {
108 	dsl_dir_t *dd;
109 	uint64_t value;
110 	dsl_prop_cb_record_t *cbr;
111 	int err;
112 
113 	dd = ds->ds_dir;
114 
115 	rw_enter(&dd->dd_pool->dp_config_rwlock, RW_READER);
116 
117 	err = dsl_prop_get_impl(dd->dd_pool, dd->dd_object, propname,
118 	    8, 1, &value, NULL);
119 	if (err == ENOENT) {
120 		err = 0;
121 		value = DSL_PROP_VALUE_UNDEFINED;
122 	}
123 	if (err != 0) {
124 		rw_exit(&dd->dd_pool->dp_config_rwlock);
125 		return (err);
126 	}
127 
128 	cbr = kmem_alloc(sizeof (dsl_prop_cb_record_t), KM_SLEEP);
129 	cbr->cbr_propname = kmem_alloc(strlen(propname)+1, KM_SLEEP);
130 	(void) strcpy((char *)cbr->cbr_propname, propname);
131 	cbr->cbr_func = callback;
132 	cbr->cbr_arg = cbarg;
133 	mutex_enter(&dd->dd_lock);
134 	list_insert_head(&dd->dd_prop_cbs, cbr);
135 	mutex_exit(&dd->dd_lock);
136 
137 	cbr->cbr_func(cbr->cbr_arg, value);
138 
139 	(void) dsl_dir_open_obj(dd->dd_pool, dd->dd_object, NULL, cbr);
140 	rw_exit(&dd->dd_pool->dp_config_rwlock);
141 	/* Leave dataset open until this callback is unregistered */
142 	return (0);
143 }
144 
145 int
146 dsl_prop_get_ds(dsl_dir_t *dd, const char *propname,
147     int intsz, int numints, void *buf, char *setpoint)
148 {
149 	int err;
150 
151 	rw_enter(&dd->dd_pool->dp_config_rwlock, RW_READER);
152 	err = dsl_prop_get_impl(dd->dd_pool, dd->dd_object,
153 	    propname, intsz, numints, buf, setpoint);
154 	rw_exit(&dd->dd_pool->dp_config_rwlock);
155 
156 	return (err);
157 }
158 
159 int
160 dsl_prop_get(const char *ddname, const char *propname,
161     int intsz, int numints, void *buf, char *setpoint)
162 {
163 	dsl_dir_t *dd;
164 	const char *tail;
165 	int err;
166 
167 	dd = dsl_dir_open(ddname, FTAG, &tail);
168 	if (dd == NULL)
169 		return (ENOENT);
170 	if (tail && tail[0] != '@') {
171 		dsl_dir_close(dd, FTAG);
172 		return (ENOENT);
173 	}
174 
175 	err = dsl_prop_get_ds(dd, propname, intsz, numints, buf, setpoint);
176 
177 	dsl_dir_close(dd, FTAG);
178 	return (err);
179 }
180 
181 /*
182  * Return 0 on success, ENOENT if ddname is invalid, EOVERFLOW if
183  * valuelen not big enough.
184  */
185 int
186 dsl_prop_get_string(const char *ddname, const char *propname,
187     char *value, int valuelen, char *setpoint)
188 {
189 	return (dsl_prop_get(ddname, propname, 1, valuelen, value, setpoint));
190 }
191 
192 /*
193  * Get the current property value.  It may have changed by the time this
194  * function returns, so it is NOT safe to follow up with
195  * dsl_prop_register() and assume that the value has not changed in
196  * between.
197  *
198  * Return 0 on success, ENOENT if ddname is invalid.
199  */
200 int
201 dsl_prop_get_integer(const char *ddname, const char *propname,
202     uint64_t *valuep, char *setpoint)
203 {
204 	return (dsl_prop_get(ddname, propname, 8, 1, valuep, setpoint));
205 }
206 
207 int
208 dsl_prop_get_ds_integer(dsl_dir_t *dd, const char *propname,
209     uint64_t *valuep, char *setpoint)
210 {
211 	return (dsl_prop_get_ds(dd, propname, 8, 1, valuep, setpoint));
212 }
213 
214 /*
215  * Unregister this callback.  Return 0 on success, ENOENT if ddname is
216  * invalid, ENOMSG if no matching callback registered.
217  */
218 int
219 dsl_prop_unregister(dsl_dataset_t *ds, const char *propname,
220     dsl_prop_changed_cb_t *callback, void *cbarg)
221 {
222 	dsl_dir_t *dd;
223 	dsl_prop_cb_record_t *cbr;
224 
225 	dd = ds->ds_dir;
226 
227 	mutex_enter(&dd->dd_lock);
228 	for (cbr = list_head(&dd->dd_prop_cbs);
229 	    cbr; cbr = list_next(&dd->dd_prop_cbs, cbr)) {
230 		if (strcmp(cbr->cbr_propname, propname) == 0 &&
231 		    cbr->cbr_func == callback &&
232 		    cbr->cbr_arg == cbarg)
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 static void
252 dsl_prop_changed_notify(dsl_pool_t *dp, uint64_t ddobj,
253     const char *propname, uint64_t value, int first)
254 {
255 	dsl_dir_t *dd;
256 	dsl_prop_cb_record_t *cbr;
257 	objset_t *mos = dp->dp_meta_objset;
258 	int err;
259 
260 	ASSERT(RW_WRITE_HELD(&dp->dp_config_rwlock));
261 	dd = dsl_dir_open_obj(dp, ddobj, NULL, FTAG);
262 
263 	if (!first) {
264 		/*
265 		 * If the prop is set here, then this change is not
266 		 * being inherited here or below; stop the recursion.
267 		 */
268 		err = zap_lookup(mos, dd->dd_phys->dd_props_zapobj, propname,
269 		    8, 1, &value);
270 		if (err == 0) {
271 			dsl_dir_close(dd, FTAG);
272 			return;
273 		}
274 		ASSERT3U(err, ==, ENOENT);
275 	}
276 
277 	mutex_enter(&dd->dd_lock);
278 	for (cbr = list_head(&dd->dd_prop_cbs);
279 	    cbr; cbr = list_next(&dd->dd_prop_cbs, cbr)) {
280 		if (strcmp(cbr->cbr_propname, propname) == 0) {
281 			cbr->cbr_func(cbr->cbr_arg, value);
282 		}
283 	}
284 	mutex_exit(&dd->dd_lock);
285 
286 	if (dd->dd_phys->dd_child_dir_zapobj) {
287 		zap_cursor_t zc;
288 		zap_attribute_t za;
289 
290 		for (zap_cursor_init(&zc, mos,
291 		    dd->dd_phys->dd_child_dir_zapobj);
292 		    zap_cursor_retrieve(&zc, &za) == 0;
293 		    zap_cursor_advance(&zc)) {
294 			/* XXX recursion could blow stack; esp. za! */
295 			dsl_prop_changed_notify(dp, za.za_first_integer,
296 			    propname, value, FALSE);
297 		}
298 		zap_cursor_fini(&zc);
299 	}
300 	dsl_dir_close(dd, FTAG);
301 }
302 
303 struct prop_set_arg {
304 	const char *name;
305 	int intsz;
306 	int numints;
307 	const void *buf;
308 };
309 
310 static int
311 dsl_prop_set_sync(dsl_dir_t *dd, void *arg, dmu_tx_t *tx)
312 {
313 	struct prop_set_arg *psa = arg;
314 	objset_t *mos = dd->dd_pool->dp_meta_objset;
315 	uint64_t zapobj = dd->dd_phys->dd_props_zapobj;
316 	uint64_t intval;
317 	int err, isint;
318 
319 	rw_enter(&dd->dd_pool->dp_config_rwlock, RW_WRITER);
320 
321 	isint = (dodefault(psa->name, 8, 1, &intval) == 0);
322 
323 	if (psa->numints == 0) {
324 		err = zap_remove(mos, zapobj, psa->name, tx);
325 		if (err == ENOENT) /* that's fine. */
326 			err = 0;
327 		if (err == 0 && isint) {
328 			err = dsl_prop_get_impl(dd->dd_pool,
329 			    dd->dd_phys->dd_parent_obj, psa->name,
330 			    8, 1, &intval, NULL);
331 		}
332 	} else {
333 		err = zap_update(mos, zapobj, psa->name,
334 		    psa->intsz, psa->numints, psa->buf, tx);
335 		if (isint)
336 			intval = *(uint64_t *)psa->buf;
337 	}
338 
339 	if (err == 0 && isint) {
340 		dsl_prop_changed_notify(dd->dd_pool,
341 		    dd->dd_object, psa->name, intval, TRUE);
342 	}
343 	rw_exit(&dd->dd_pool->dp_config_rwlock);
344 
345 	return (err);
346 }
347 
348 int
349 dsl_prop_set(const char *ddname, const char *propname,
350     int intsz, int numints, const void *buf)
351 {
352 	dsl_dir_t *dd;
353 	int err;
354 	struct prop_set_arg psa;
355 
356 	dd = dsl_dir_open(ddname, FTAG, NULL);
357 	if (dd == NULL)
358 		return (ENOENT);
359 
360 	psa.name = propname;
361 	psa.intsz = intsz;
362 	psa.numints = numints;
363 	psa.buf = buf;
364 	err = dsl_dir_sync_task(dd, dsl_prop_set_sync, &psa, 0);
365 
366 	dsl_dir_close(dd, FTAG);
367 
368 	return (err);
369 }
370 
371 /*
372  * Iterate over all properties for this dataset and return them in an nvlist.
373  */
374 int
375 dsl_prop_get_all(objset_t *os, nvlist_t **nvp)
376 {
377 	dsl_dataset_t *ds = os->os->os_dsl_dataset;
378 	dsl_dir_t *dd, *parent;
379 	int err = 0;
380 	dsl_pool_t *dp;
381 	objset_t *mos;
382 	zap_cursor_t zc;
383 	zap_attribute_t za;
384 	char setpoint[MAXNAMELEN];
385 	char *tmp;
386 	nvlist_t *prop;
387 
388 	if (dsl_dataset_is_snapshot(ds)) {
389 		VERIFY(nvlist_alloc(nvp, NV_UNIQUE_NAME, KM_SLEEP) == 0);
390 		return (0);
391 	}
392 
393 	dd = ds->ds_dir;
394 
395 	VERIFY(nvlist_alloc(nvp, NV_UNIQUE_NAME, KM_SLEEP) == 0);
396 
397 	dp = dd->dd_pool;
398 	mos = dp->dp_meta_objset;
399 
400 	rw_enter(&dp->dp_config_rwlock, RW_READER);
401 	while (dd != NULL) {
402 		dsl_dir_name(dd, setpoint);
403 
404 		for (zap_cursor_init(&zc, mos, dd->dd_phys->dd_props_zapobj);
405 		    (err = zap_cursor_retrieve(&zc, &za)) == 0;
406 		    zap_cursor_advance(&zc)) {
407 			if (nvlist_lookup_nvlist(*nvp, za.za_name, &prop) == 0)
408 				continue;
409 
410 			VERIFY(nvlist_alloc(&prop, NV_UNIQUE_NAME,
411 			    KM_SLEEP) == 0);
412 			if (za.za_integer_length == 1) {
413 				/*
414 				 * String property
415 				 */
416 
417 				tmp = kmem_alloc(za.za_num_integers, KM_SLEEP);
418 				err = zap_lookup(mos,
419 				    dd->dd_phys->dd_props_zapobj,
420 				    za.za_name, 1, za.za_num_integers,
421 				    tmp);
422 				if (err != 0) {
423 					kmem_free(tmp, za.za_num_integers);
424 					break;
425 				}
426 				VERIFY(nvlist_add_string(prop,
427 				    ZFS_PROP_VALUE, tmp) == 0);
428 				kmem_free(tmp, za.za_num_integers);
429 			} else {
430 				/*
431 				 * Integer property
432 				 */
433 				ASSERT(za.za_integer_length == 8);
434 				(void) nvlist_add_uint64(prop, ZFS_PROP_VALUE,
435 				    za.za_first_integer);
436 			}
437 
438 			VERIFY(nvlist_add_string(prop,
439 			    ZFS_PROP_SOURCE, setpoint) == 0);
440 			VERIFY(nvlist_add_nvlist(*nvp, za.za_name,
441 			    prop) == 0);
442 			nvlist_free(prop);
443 		}
444 		zap_cursor_fini(&zc);
445 
446 		if (err != ENOENT) {
447 			if (dd != ds->ds_dir)
448 				dsl_dir_close(dd, FTAG);
449 			break;
450 		} else {
451 			err = 0;
452 		}
453 
454 		/*
455 		 * Continue to parent.
456 		 */
457 		if (dd->dd_phys->dd_parent_obj == 0)
458 			parent = NULL;
459 		else
460 			parent = dsl_dir_open_obj(dp,
461 			    dd->dd_phys->dd_parent_obj, NULL, FTAG);
462 		if (dd != ds->ds_dir)
463 			dsl_dir_close(dd, FTAG);
464 		dd = parent;
465 	}
466 	rw_exit(&dp->dp_config_rwlock);
467 
468 	return (err);
469 }
470