xref: /titanic_44/usr/src/lib/libzfs/common/libzfs_config.c (revision a60349c89adffc0902b2353230891d8e7f2b24d9)
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 /*
23  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 /*
28  * Copyright (c) 2012 by Delphix. All rights reserved.
29  */
30 
31 /*
32  * The pool configuration repository is stored in /etc/zfs/zpool.cache as a
33  * single packed nvlist.  While it would be nice to just read in this
34  * file from userland, this wouldn't work from a local zone.  So we have to have
35  * a zpool ioctl to return the complete configuration for all pools.  In the
36  * global zone, this will be identical to reading the file and unpacking it in
37  * userland.
38  */
39 
40 #include <errno.h>
41 #include <sys/stat.h>
42 #include <fcntl.h>
43 #include <stddef.h>
44 #include <string.h>
45 #include <unistd.h>
46 #include <libintl.h>
47 #include <libuutil.h>
48 
49 #include "libzfs_impl.h"
50 
51 typedef struct config_node {
52 	char		*cn_name;
53 	nvlist_t	*cn_config;
54 	uu_avl_node_t	cn_avl;
55 } config_node_t;
56 
57 /* ARGSUSED */
58 static int
59 config_node_compare(const void *a, const void *b, void *unused)
60 {
61 	int ret;
62 
63 	const config_node_t *ca = (config_node_t *)a;
64 	const config_node_t *cb = (config_node_t *)b;
65 
66 	ret = strcmp(ca->cn_name, cb->cn_name);
67 
68 	if (ret < 0)
69 		return (-1);
70 	else if (ret > 0)
71 		return (1);
72 	else
73 		return (0);
74 }
75 
76 void
77 namespace_clear(libzfs_handle_t *hdl)
78 {
79 	if (hdl->libzfs_ns_avl) {
80 		config_node_t *cn;
81 		void *cookie = NULL;
82 
83 		while ((cn = uu_avl_teardown(hdl->libzfs_ns_avl,
84 		    &cookie)) != NULL) {
85 			nvlist_free(cn->cn_config);
86 			free(cn->cn_name);
87 			free(cn);
88 		}
89 
90 		uu_avl_destroy(hdl->libzfs_ns_avl);
91 		hdl->libzfs_ns_avl = NULL;
92 	}
93 
94 	if (hdl->libzfs_ns_avlpool) {
95 		uu_avl_pool_destroy(hdl->libzfs_ns_avlpool);
96 		hdl->libzfs_ns_avlpool = NULL;
97 	}
98 }
99 
100 /*
101  * Loads the pool namespace, or re-loads it if the cache has changed.
102  */
103 static int
104 namespace_reload(libzfs_handle_t *hdl)
105 {
106 	nvlist_t *config;
107 	config_node_t *cn;
108 	nvpair_t *elem;
109 	zfs_cmd_t zc = { 0 };
110 	void *cookie;
111 
112 	if (hdl->libzfs_ns_gen == 0) {
113 		/*
114 		 * This is the first time we've accessed the configuration
115 		 * cache.  Initialize the AVL tree and then fall through to the
116 		 * common code.
117 		 */
118 		if ((hdl->libzfs_ns_avlpool = uu_avl_pool_create("config_pool",
119 		    sizeof (config_node_t),
120 		    offsetof(config_node_t, cn_avl),
121 		    config_node_compare, UU_DEFAULT)) == NULL)
122 			return (no_memory(hdl));
123 
124 		if ((hdl->libzfs_ns_avl = uu_avl_create(hdl->libzfs_ns_avlpool,
125 		    NULL, UU_DEFAULT)) == NULL)
126 			return (no_memory(hdl));
127 	}
128 
129 	if (zcmd_alloc_dst_nvlist(hdl, &zc, 0) != 0)
130 		return (-1);
131 
132 	for (;;) {
133 		zc.zc_cookie = hdl->libzfs_ns_gen;
134 		if (ioctl(hdl->libzfs_fd, ZFS_IOC_POOL_CONFIGS, &zc) != 0) {
135 			switch (errno) {
136 			case EEXIST:
137 				/*
138 				 * The namespace hasn't changed.
139 				 */
140 				zcmd_free_nvlists(&zc);
141 				return (0);
142 
143 			case ENOMEM:
144 				if (zcmd_expand_dst_nvlist(hdl, &zc) != 0) {
145 					zcmd_free_nvlists(&zc);
146 					return (-1);
147 				}
148 				break;
149 
150 			default:
151 				zcmd_free_nvlists(&zc);
152 				return (zfs_standard_error(hdl, errno,
153 				    dgettext(TEXT_DOMAIN, "failed to read "
154 				    "pool configuration")));
155 			}
156 		} else {
157 			hdl->libzfs_ns_gen = zc.zc_cookie;
158 			break;
159 		}
160 	}
161 
162 	if (zcmd_read_dst_nvlist(hdl, &zc, &config) != 0) {
163 		zcmd_free_nvlists(&zc);
164 		return (-1);
165 	}
166 
167 	zcmd_free_nvlists(&zc);
168 
169 	/*
170 	 * Clear out any existing configuration information.
171 	 */
172 	cookie = NULL;
173 	while ((cn = uu_avl_teardown(hdl->libzfs_ns_avl, &cookie)) != NULL) {
174 		nvlist_free(cn->cn_config);
175 		free(cn->cn_name);
176 		free(cn);
177 	}
178 
179 	elem = NULL;
180 	while ((elem = nvlist_next_nvpair(config, elem)) != NULL) {
181 		nvlist_t *child;
182 		uu_avl_index_t where;
183 
184 		if ((cn = zfs_alloc(hdl, sizeof (config_node_t))) == NULL) {
185 			nvlist_free(config);
186 			return (-1);
187 		}
188 
189 		if ((cn->cn_name = zfs_strdup(hdl,
190 		    nvpair_name(elem))) == NULL) {
191 			free(cn);
192 			nvlist_free(config);
193 			return (-1);
194 		}
195 
196 		verify(nvpair_value_nvlist(elem, &child) == 0);
197 		if (nvlist_dup(child, &cn->cn_config, 0) != 0) {
198 			free(cn->cn_name);
199 			free(cn);
200 			nvlist_free(config);
201 			return (no_memory(hdl));
202 		}
203 		verify(uu_avl_find(hdl->libzfs_ns_avl, cn, NULL, &where)
204 		    == NULL);
205 
206 		uu_avl_insert(hdl->libzfs_ns_avl, cn, where);
207 	}
208 
209 	nvlist_free(config);
210 	return (0);
211 }
212 
213 /*
214  * Retrieve the configuration for the given pool.  The configuration is a nvlist
215  * describing the vdevs, as well as the statistics associated with each one.
216  */
217 nvlist_t *
218 zpool_get_config(zpool_handle_t *zhp, nvlist_t **oldconfig)
219 {
220 	if (oldconfig)
221 		*oldconfig = zhp->zpool_old_config;
222 	return (zhp->zpool_config);
223 }
224 
225 /*
226  * Retrieves a list of enabled features and their refcounts and caches it in
227  * the pool handle.
228  */
229 nvlist_t *
230 zpool_get_features(zpool_handle_t *zhp)
231 {
232 	nvlist_t *config, *features;
233 
234 	config = zpool_get_config(zhp, NULL);
235 
236 	if (config == NULL || !nvlist_exists(config,
237 	    ZPOOL_CONFIG_FEATURE_STATS)) {
238 		int error;
239 		boolean_t missing = B_FALSE;
240 
241 		error = zpool_refresh_stats(zhp, &missing);
242 
243 		if (error != 0 || missing)
244 			return (NULL);
245 
246 		config = zpool_get_config(zhp, NULL);
247 	}
248 
249 	verify(nvlist_lookup_nvlist(config, ZPOOL_CONFIG_FEATURE_STATS,
250 	    &features) == 0);
251 
252 	return (features);
253 }
254 
255 /*
256  * Refresh the vdev statistics associated with the given pool.  This is used in
257  * iostat to show configuration changes and determine the delta from the last
258  * time the function was called.  This function can fail, in case the pool has
259  * been destroyed.
260  */
261 int
262 zpool_refresh_stats(zpool_handle_t *zhp, boolean_t *missing)
263 {
264 	zfs_cmd_t zc = { 0 };
265 	int error;
266 	nvlist_t *config;
267 	libzfs_handle_t *hdl = zhp->zpool_hdl;
268 
269 	*missing = B_FALSE;
270 	(void) strcpy(zc.zc_name, zhp->zpool_name);
271 
272 	if (zhp->zpool_config_size == 0)
273 		zhp->zpool_config_size = 1 << 16;
274 
275 	if (zcmd_alloc_dst_nvlist(hdl, &zc, zhp->zpool_config_size) != 0)
276 		return (-1);
277 
278 	for (;;) {
279 		if (ioctl(zhp->zpool_hdl->libzfs_fd, ZFS_IOC_POOL_STATS,
280 		    &zc) == 0) {
281 			/*
282 			 * The real error is returned in the zc_cookie field.
283 			 */
284 			error = zc.zc_cookie;
285 			break;
286 		}
287 
288 		if (errno == ENOMEM) {
289 			if (zcmd_expand_dst_nvlist(hdl, &zc) != 0) {
290 				zcmd_free_nvlists(&zc);
291 				return (-1);
292 			}
293 		} else {
294 			zcmd_free_nvlists(&zc);
295 			if (errno == ENOENT || errno == EINVAL)
296 				*missing = B_TRUE;
297 			zhp->zpool_state = POOL_STATE_UNAVAIL;
298 			return (0);
299 		}
300 	}
301 
302 	if (zcmd_read_dst_nvlist(hdl, &zc, &config) != 0) {
303 		zcmd_free_nvlists(&zc);
304 		return (-1);
305 	}
306 
307 	zcmd_free_nvlists(&zc);
308 
309 	zhp->zpool_config_size = zc.zc_nvlist_dst_size;
310 
311 	if (zhp->zpool_config != NULL) {
312 		uint64_t oldtxg, newtxg;
313 
314 		verify(nvlist_lookup_uint64(zhp->zpool_config,
315 		    ZPOOL_CONFIG_POOL_TXG, &oldtxg) == 0);
316 		verify(nvlist_lookup_uint64(config,
317 		    ZPOOL_CONFIG_POOL_TXG, &newtxg) == 0);
318 
319 		if (zhp->zpool_old_config != NULL)
320 			nvlist_free(zhp->zpool_old_config);
321 
322 		if (oldtxg != newtxg) {
323 			nvlist_free(zhp->zpool_config);
324 			zhp->zpool_old_config = NULL;
325 		} else {
326 			zhp->zpool_old_config = zhp->zpool_config;
327 		}
328 	}
329 
330 	zhp->zpool_config = config;
331 	if (error)
332 		zhp->zpool_state = POOL_STATE_UNAVAIL;
333 	else
334 		zhp->zpool_state = POOL_STATE_ACTIVE;
335 
336 	return (0);
337 }
338 
339 /*
340  * If the __ZFS_POOL_RESTRICT environment variable is set we only iterate over
341  * pools it lists.
342  *
343  * This is an undocumented feature for use during testing only.
344  *
345  * This function returns B_TRUE if the pool should be skipped
346  * during iteration.
347  */
348 static boolean_t
349 check_restricted(const char *poolname)
350 {
351 	static boolean_t initialized = B_FALSE;
352 	static char *restricted = NULL;
353 
354 	const char *cur, *end;
355 	int len, namelen;
356 
357 	if (!initialized) {
358 		initialized = B_TRUE;
359 		restricted = getenv("__ZFS_POOL_RESTRICT");
360 	}
361 
362 	if (NULL == restricted)
363 		return (B_FALSE);
364 
365 	cur = restricted;
366 	namelen = strlen(poolname);
367 	do {
368 		end = strchr(cur, ' ');
369 		len = (NULL == end) ? strlen(cur) : (end - cur);
370 
371 		if (len == namelen && 0 == strncmp(cur, poolname, len)) {
372 			return (B_FALSE);
373 		}
374 
375 		cur += (len + 1);
376 	} while (NULL != end);
377 
378 	return (B_TRUE);
379 }
380 
381 /*
382  * Iterate over all pools in the system.
383  */
384 int
385 zpool_iter(libzfs_handle_t *hdl, zpool_iter_f func, void *data)
386 {
387 	config_node_t *cn;
388 	zpool_handle_t *zhp;
389 	int ret;
390 
391 	/*
392 	 * If someone makes a recursive call to zpool_iter(), we want to avoid
393 	 * refreshing the namespace because that will invalidate the parent
394 	 * context.  We allow recursive calls, but simply re-use the same
395 	 * namespace AVL tree.
396 	 */
397 	if (!hdl->libzfs_pool_iter && namespace_reload(hdl) != 0)
398 		return (-1);
399 
400 	hdl->libzfs_pool_iter++;
401 	for (cn = uu_avl_first(hdl->libzfs_ns_avl); cn != NULL;
402 	    cn = uu_avl_next(hdl->libzfs_ns_avl, cn)) {
403 
404 		if (check_restricted(cn->cn_name))
405 			continue;
406 
407 		if (zpool_open_silent(hdl, cn->cn_name, &zhp) != 0) {
408 			hdl->libzfs_pool_iter--;
409 			return (-1);
410 		}
411 
412 		if (zhp == NULL)
413 			continue;
414 
415 		if ((ret = func(zhp, data)) != 0) {
416 			hdl->libzfs_pool_iter--;
417 			return (ret);
418 		}
419 	}
420 	hdl->libzfs_pool_iter--;
421 
422 	return (0);
423 }
424 
425 /*
426  * Iterate over root datasets, calling the given function for each.  The zfs
427  * handle passed each time must be explicitly closed by the callback.
428  */
429 int
430 zfs_iter_root(libzfs_handle_t *hdl, zfs_iter_f func, void *data)
431 {
432 	config_node_t *cn;
433 	zfs_handle_t *zhp;
434 	int ret;
435 
436 	if (namespace_reload(hdl) != 0)
437 		return (-1);
438 
439 	for (cn = uu_avl_first(hdl->libzfs_ns_avl); cn != NULL;
440 	    cn = uu_avl_next(hdl->libzfs_ns_avl, cn)) {
441 
442 		if (check_restricted(cn->cn_name))
443 			continue;
444 
445 		if ((zhp = make_dataset_handle(hdl, cn->cn_name)) == NULL)
446 			continue;
447 
448 		if ((ret = func(zhp, data)) != 0)
449 			return (ret);
450 	}
451 
452 	return (0);
453 }
454