xref: /titanic_51/usr/src/uts/common/fs/zfs/spa_config.c (revision cf5b5989488984444a152faba2a8183a71dcf485)
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 2007 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/spa.h>
30 #include <sys/spa_impl.h>
31 #include <sys/nvpair.h>
32 #include <sys/uio.h>
33 #include <sys/fs/zfs.h>
34 #include <sys/vdev_impl.h>
35 #include <sys/zfs_ioctl.h>
36 #include <sys/utsname.h>
37 #include <sys/systeminfo.h>
38 #include <sys/sunddi.h>
39 #ifdef _KERNEL
40 #include <sys/kobj.h>
41 #endif
42 
43 /*
44  * Pool configuration repository.
45  *
46  * The configuration for all pools, in addition to being stored on disk, is
47  * stored in /etc/zfs/zpool.cache as a packed nvlist.  The kernel maintains
48  * this list as pools are created, destroyed, or modified.
49  *
50  * We have a single nvlist which holds all the configuration information.  When
51  * the module loads, we read this information from the cache and populate the
52  * SPA namespace.  This namespace is maintained independently in spa.c.
53  * Whenever the namespace is modified, or the configuration of a pool is
54  * changed, we call spa_config_sync(), which walks through all the active pools
55  * and writes the configuration to disk.
56  */
57 
58 static uint64_t spa_config_generation = 1;
59 
60 /*
61  * This can be overridden in userland to preserve an alternate namespace for
62  * userland pools when doing testing.
63  */
64 const char *spa_config_dir = ZPOOL_CACHE_DIR;
65 
66 /*
67  * Called when the module is first loaded, this routine loads the configuration
68  * file into the SPA namespace.  It does not actually open or load the pools; it
69  * only populates the namespace.
70  */
71 void
72 spa_config_load(void)
73 {
74 	void *buf = NULL;
75 	nvlist_t *nvlist, *child;
76 	nvpair_t *nvpair;
77 	spa_t *spa;
78 	char pathname[128];
79 	struct _buf *file;
80 	uint64_t fsize;
81 
82 	/*
83 	 * Open the configuration file.
84 	 */
85 	(void) snprintf(pathname, sizeof (pathname), "%s%s/%s",
86 	    (rootdir != NULL) ? "./" : "", spa_config_dir, ZPOOL_CACHE_FILE);
87 
88 	file = kobj_open_file(pathname);
89 	if (file == (struct _buf *)-1)
90 		return;
91 
92 	if (kobj_get_filesize(file, &fsize) != 0)
93 		goto out;
94 
95 	buf = kmem_alloc(fsize, KM_SLEEP);
96 
97 	/*
98 	 * Read the nvlist from the file.
99 	 */
100 	if (kobj_read_file(file, buf, fsize, 0) < 0)
101 		goto out;
102 
103 	/*
104 	 * Unpack the nvlist.
105 	 */
106 	if (nvlist_unpack(buf, fsize, &nvlist, KM_SLEEP) != 0)
107 		goto out;
108 
109 	/*
110 	 * Iterate over all elements in the nvlist, creating a new spa_t for
111 	 * each one with the specified configuration.
112 	 */
113 	mutex_enter(&spa_namespace_lock);
114 	nvpair = NULL;
115 	while ((nvpair = nvlist_next_nvpair(nvlist, nvpair)) != NULL) {
116 
117 		if (nvpair_type(nvpair) != DATA_TYPE_NVLIST)
118 			continue;
119 
120 		VERIFY(nvpair_value_nvlist(nvpair, &child) == 0);
121 
122 		if (spa_lookup(nvpair_name(nvpair)) != NULL)
123 			continue;
124 		spa = spa_add(nvpair_name(nvpair), NULL);
125 
126 		/*
127 		 * We blindly duplicate the configuration here.  If it's
128 		 * invalid, we will catch it when the pool is first opened.
129 		 */
130 		VERIFY(nvlist_dup(child, &spa->spa_config, 0) == 0);
131 	}
132 	mutex_exit(&spa_namespace_lock);
133 
134 	nvlist_free(nvlist);
135 
136 out:
137 	if (buf != NULL)
138 		kmem_free(buf, fsize);
139 
140 	kobj_close_file(file);
141 }
142 
143 /*
144  * Synchronize all pools to disk.  This must be called with the namespace lock
145  * held.
146  */
147 void
148 spa_config_sync(void)
149 {
150 	spa_t *spa = NULL;
151 	nvlist_t *config;
152 	size_t buflen;
153 	char *buf;
154 	vnode_t *vp;
155 	int oflags = FWRITE | FTRUNC | FCREAT | FOFFMAX;
156 	char pathname[128];
157 	char pathname2[128];
158 
159 	ASSERT(MUTEX_HELD(&spa_namespace_lock));
160 
161 	VERIFY(nvlist_alloc(&config, NV_UNIQUE_NAME, KM_SLEEP) == 0);
162 
163 	/*
164 	 * Add all known pools to the configuration list, ignoring those with
165 	 * alternate root paths.
166 	 */
167 	spa = NULL;
168 	while ((spa = spa_next(spa)) != NULL) {
169 		mutex_enter(&spa->spa_config_cache_lock);
170 		if (spa->spa_config && spa->spa_name && !spa->spa_temporary) {
171 			VERIFY(nvlist_add_nvlist(config, spa->spa_name,
172 			    spa->spa_config) == 0);
173 		}
174 		mutex_exit(&spa->spa_config_cache_lock);
175 	}
176 
177 	/*
178 	 * Pack the configuration into a buffer.
179 	 */
180 	VERIFY(nvlist_size(config, &buflen, NV_ENCODE_XDR) == 0);
181 
182 	buf = kmem_alloc(buflen, KM_SLEEP);
183 
184 	VERIFY(nvlist_pack(config, &buf, &buflen, NV_ENCODE_XDR,
185 	    KM_SLEEP) == 0);
186 
187 	/*
188 	 * Write the configuration to disk.  We need to do the traditional
189 	 * 'write to temporary file, sync, move over original' to make sure we
190 	 * always have a consistent view of the data.
191 	 */
192 	(void) snprintf(pathname, sizeof (pathname), "%s/%s", spa_config_dir,
193 	    ZPOOL_CACHE_TMP);
194 
195 	if (vn_open(pathname, UIO_SYSSPACE, oflags, 0644, &vp, CRCREAT, 0) != 0)
196 		goto out;
197 
198 	if (vn_rdwr(UIO_WRITE, vp, buf, buflen, 0, UIO_SYSSPACE,
199 	    0, RLIM64_INFINITY, kcred, NULL) == 0 &&
200 	    VOP_FSYNC(vp, FSYNC, kcred) == 0) {
201 		(void) snprintf(pathname2, sizeof (pathname2), "%s/%s",
202 		    spa_config_dir, ZPOOL_CACHE_FILE);
203 		(void) vn_rename(pathname, pathname2, UIO_SYSSPACE);
204 	}
205 
206 	(void) VOP_CLOSE(vp, oflags, 1, 0, kcred);
207 	VN_RELE(vp);
208 
209 out:
210 	(void) vn_remove(pathname, UIO_SYSSPACE, RMFILE);
211 	spa_config_generation++;
212 
213 	kmem_free(buf, buflen);
214 	nvlist_free(config);
215 }
216 
217 /*
218  * Sigh.  Inside a local zone, we don't have access to /etc/zfs/zpool.cache,
219  * and we don't want to allow the local zone to see all the pools anyway.
220  * So we have to invent the ZFS_IOC_CONFIG ioctl to grab the configuration
221  * information for all pool visible within the zone.
222  */
223 nvlist_t *
224 spa_all_configs(uint64_t *generation)
225 {
226 	nvlist_t *pools;
227 	spa_t *spa;
228 
229 	if (*generation == spa_config_generation)
230 		return (NULL);
231 
232 	VERIFY(nvlist_alloc(&pools, NV_UNIQUE_NAME, KM_SLEEP) == 0);
233 
234 	spa = NULL;
235 	mutex_enter(&spa_namespace_lock);
236 	while ((spa = spa_next(spa)) != NULL) {
237 		if (INGLOBALZONE(curproc) ||
238 		    zone_dataset_visible(spa_name(spa), NULL)) {
239 			mutex_enter(&spa->spa_config_cache_lock);
240 			VERIFY(nvlist_add_nvlist(pools, spa_name(spa),
241 			    spa->spa_config) == 0);
242 			mutex_exit(&spa->spa_config_cache_lock);
243 		}
244 	}
245 	mutex_exit(&spa_namespace_lock);
246 
247 	*generation = spa_config_generation;
248 
249 	return (pools);
250 }
251 
252 void
253 spa_config_set(spa_t *spa, nvlist_t *config)
254 {
255 	mutex_enter(&spa->spa_config_cache_lock);
256 	if (spa->spa_config != NULL)
257 		nvlist_free(spa->spa_config);
258 	spa->spa_config = config;
259 	mutex_exit(&spa->spa_config_cache_lock);
260 }
261 
262 /*
263  * Generate the pool's configuration based on the current in-core state.
264  * We infer whether to generate a complete config or just one top-level config
265  * based on whether vd is the root vdev.
266  */
267 nvlist_t *
268 spa_config_generate(spa_t *spa, vdev_t *vd, uint64_t txg, int getstats)
269 {
270 	nvlist_t *config, *nvroot;
271 	vdev_t *rvd = spa->spa_root_vdev;
272 	unsigned long hostid = 0;
273 
274 	ASSERT(spa_config_held(spa, RW_READER) ||
275 	    spa_config_held(spa, RW_WRITER));
276 
277 	if (vd == NULL)
278 		vd = rvd;
279 
280 	/*
281 	 * If txg is -1, report the current value of spa->spa_config_txg.
282 	 */
283 	if (txg == -1ULL)
284 		txg = spa->spa_config_txg;
285 
286 	VERIFY(nvlist_alloc(&config, NV_UNIQUE_NAME, KM_SLEEP) == 0);
287 
288 	VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_VERSION,
289 	    spa_version(spa)) == 0);
290 	VERIFY(nvlist_add_string(config, ZPOOL_CONFIG_POOL_NAME,
291 	    spa_name(spa)) == 0);
292 	VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_STATE,
293 	    spa_state(spa)) == 0);
294 	VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_TXG,
295 	    txg) == 0);
296 	VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_GUID,
297 	    spa_guid(spa)) == 0);
298 	(void) ddi_strtoul(hw_serial, NULL, 10, &hostid);
299 	if (hostid != 0) {
300 		VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_HOSTID,
301 		    hostid) == 0);
302 	}
303 	VERIFY(nvlist_add_string(config, ZPOOL_CONFIG_HOSTNAME,
304 	    utsname.nodename) == 0);
305 
306 	if (vd != rvd) {
307 		VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_TOP_GUID,
308 		    vd->vdev_top->vdev_guid) == 0);
309 		VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_GUID,
310 		    vd->vdev_guid) == 0);
311 		if (vd->vdev_isspare)
312 			VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_IS_SPARE,
313 			    1ULL) == 0);
314 		if (vd->vdev_islog)
315 			VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_IS_LOG,
316 			    1ULL) == 0);
317 		vd = vd->vdev_top;		/* label contains top config */
318 	}
319 
320 	nvroot = vdev_config_generate(spa, vd, getstats, B_FALSE);
321 	VERIFY(nvlist_add_nvlist(config, ZPOOL_CONFIG_VDEV_TREE, nvroot) == 0);
322 	nvlist_free(nvroot);
323 
324 	return (config);
325 }
326 
327 /*
328  * Update all disk labels, generate a fresh config based on the current
329  * in-core state, and sync the global config cache.
330  */
331 void
332 spa_config_update(spa_t *spa, int what)
333 {
334 	vdev_t *rvd = spa->spa_root_vdev;
335 	uint64_t txg;
336 	int c;
337 
338 	ASSERT(MUTEX_HELD(&spa_namespace_lock));
339 
340 	spa_config_enter(spa, RW_WRITER, FTAG);
341 	txg = spa_last_synced_txg(spa) + 1;
342 	if (what == SPA_CONFIG_UPDATE_POOL) {
343 		vdev_config_dirty(rvd);
344 	} else {
345 		/*
346 		 * If we have top-level vdevs that were added but have
347 		 * not yet been prepared for allocation, do that now.
348 		 * (It's safe now because the config cache is up to date,
349 		 * so it will be able to translate the new DVAs.)
350 		 * See comments in spa_vdev_add() for full details.
351 		 */
352 		for (c = 0; c < rvd->vdev_children; c++) {
353 			vdev_t *tvd = rvd->vdev_child[c];
354 			if (tvd->vdev_ms_array == 0) {
355 				vdev_init(tvd, txg);
356 				vdev_config_dirty(tvd);
357 			}
358 		}
359 	}
360 	spa_config_exit(spa, FTAG);
361 
362 	/*
363 	 * Wait for the mosconfig to be regenerated and synced.
364 	 */
365 	txg_wait_synced(spa->spa_dsl_pool, txg);
366 
367 	/*
368 	 * Update the global config cache to reflect the new mosconfig.
369 	 */
370 	spa_config_sync();
371 
372 	if (what == SPA_CONFIG_UPDATE_POOL)
373 		spa_config_update(spa, SPA_CONFIG_UPDATE_VDEVS);
374 }
375