lib/libzfs/libzfs_import.c

   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 https://opensource.org/licenses/CDDL-1.0.
  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 2015 Nexenta Systems, Inc. All rights reserved.
  23  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
  24  * Copyright (c) 2012, 2018 by Delphix. All rights reserved.
  25  * Copyright 2015 RackTop Systems.
  26  * Copyright (c) 2016, Intel Corporation.
  27  */
  28
  29 #include <errno.h>
  30 #include <libintl.h>
  31 #include <libgen.h>
  32 #include <stddef.h>
  33 #include <stdlib.h>
  34 #include <string.h>
  35 #include <sys/stat.h>
  36 #include <unistd.h>
  37 #include <sys/vdev_impl.h>
  38 #include <libzfs.h>
  39 #include "libzfs_impl.h"
  40 #include <libzutil.h>
  41 #include <sys/arc_impl.h>
  42
  43 /*
  44  * Returns true if the named pool matches the given GUID.
  45  */
  46 static int
  47 pool_active(libzfs_handle_t *hdl, const char *name, uint64_t guid,
  48     boolean_t *isactive)
  49 {
  50         zpool_handle_t *zhp;
  51
  52         if (zpool_open_silent(hdl, name, &zhp) != 0)
  53                 return (-1);
  54
  55         if (zhp == NULL) {
  56                 *isactive = B_FALSE;
  57                 return (0);
  58         }
  59
  60         uint64_t theguid = fnvlist_lookup_uint64(zhp->zpool_config,
  61             ZPOOL_CONFIG_POOL_GUID);
  62
  63         zpool_close(zhp);
  64
  65         *isactive = (theguid == guid);
  66         return (0);
  67 }
  68
  69 static nvlist_t *
  70 refresh_config(libzfs_handle_t *hdl, nvlist_t *config)
  71 {
  72         nvlist_t *nvl;
  73         zfs_cmd_t zc = {"\0"};
  74         int err, dstbuf_size;
  75
  76         zcmd_write_conf_nvlist(hdl, &zc, config);
  77
  78         dstbuf_size = MAX(CONFIG_BUF_MINSIZE, zc.zc_nvlist_conf_size * 32);
  79
  80         zcmd_alloc_dst_nvlist(hdl, &zc, dstbuf_size);
  81
  82         while ((err = zfs_ioctl(hdl, ZFS_IOC_POOL_TRYIMPORT,
  83             &zc)) != 0 && errno == ENOMEM)
  84                 zcmd_expand_dst_nvlist(hdl, &zc);
  85
  86         if (err) {
  87                 zcmd_free_nvlists(&zc);
  88                 return (NULL);
  89         }
  90
  91         if (zcmd_read_dst_nvlist(hdl, &zc, &nvl) != 0) {
  92                 zcmd_free_nvlists(&zc);
  93                 return (NULL);
  94         }
  95
  96         zcmd_free_nvlists(&zc);
  97         return (nvl);
  98 }
  99
 100 static nvlist_t *
 101 refresh_config_libzfs(void *handle, nvlist_t *tryconfig)
 102 {
 103         return (refresh_config((libzfs_handle_t *)handle, tryconfig));
 104 }
 105
 106 static int
 107 pool_active_libzfs(void *handle, const char *name, uint64_t guid,
 108     boolean_t *isactive)
 109 {
 110         return (pool_active((libzfs_handle_t *)handle, name, guid, isactive));
 111 }
 112
 113 const pool_config_ops_t libzfs_config_ops = {
 114         .pco_refresh_config = refresh_config_libzfs,
 115         .pco_pool_active = pool_active_libzfs,
 116 };
 117
 118 /*
 119  * Return the offset of the given label.
 120  */
 121 static uint64_t
 122 label_offset(uint64_t size, int l)
 123 {
 124         ASSERT(P2PHASE_TYPED(size, sizeof (vdev_label_t), uint64_t) == 0);
 125         return (l * sizeof (vdev_label_t) + (l < VDEV_LABELS / 2 ?
 126             0 : size - VDEV_LABELS * sizeof (vdev_label_t)));
 127 }
 128
 129 /*
 130  * Given a file descriptor, clear (zero) the label information.  This function
 131  * is used in the appliance stack as part of the ZFS sysevent module and
 132  * to implement the "zpool labelclear" command.
 133  */
 134 int
 135 zpool_clear_label(int fd)
 136 {
 137         struct stat64 statbuf;
 138         int l;
 139         vdev_label_t *label;
 140         uint64_t size;
 141         boolean_t labels_cleared = B_FALSE, clear_l2arc_header = B_FALSE,
 142             header_cleared = B_FALSE;
 143
 144         if (fstat64_blk(fd, &statbuf) == -1)
 145                 return (0);
 146
 147         size = P2ALIGN_TYPED(statbuf.st_size, sizeof (vdev_label_t), uint64_t);
 148
 149         if ((label = calloc(1, sizeof (vdev_label_t))) == NULL)
 150                 return (-1);
 151
 152         for (l = 0; l < VDEV_LABELS; l++) {
 153                 uint64_t state, guid, l2cache;
 154                 nvlist_t *config;
 155
 156                 if (pread64(fd, label, sizeof (vdev_label_t),
 157                     label_offset(size, l)) != sizeof (vdev_label_t)) {
 158                         continue;
 159                 }
 160
 161                 if (nvlist_unpack(label->vl_vdev_phys.vp_nvlist,
 162                     sizeof (label->vl_vdev_phys.vp_nvlist), &config, 0) != 0) {
 163                         continue;
 164                 }
 165
 166                 /* Skip labels which do not have a valid guid. */
 167                 if (nvlist_lookup_uint64(config, ZPOOL_CONFIG_GUID,
 168                     &guid) != 0 || guid == 0) {
 169                         nvlist_free(config);
 170                         continue;
 171                 }
 172
 173                 /* Skip labels which are not in a known valid state. */
 174                 if (nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_STATE,
 175                     &state) != 0 || state > POOL_STATE_L2CACHE) {
 176                         nvlist_free(config);
 177                         continue;
 178                 }
 179
 180                 /* If the device is a cache device clear the header. */
 181                 if (!clear_l2arc_header) {
 182                         if (nvlist_lookup_uint64(config,
 183                             ZPOOL_CONFIG_POOL_STATE, &l2cache) == 0 &&
 184                             l2cache == POOL_STATE_L2CACHE) {
 185                                 clear_l2arc_header = B_TRUE;
 186                         }
 187                 }
 188
 189                 nvlist_free(config);
 190
 191                 /*
 192                  * A valid label was found, overwrite this label's nvlist
 193                  * and uberblocks with zeros on disk.  This is done to prevent
 194                  * system utilities, like blkid, from incorrectly detecting a
 195                  * partial label.  The leading pad space is left untouched.
 196                  */
 197                 memset(label, 0, sizeof (vdev_label_t));
 198                 size_t label_size = sizeof (vdev_label_t) - (2 * VDEV_PAD_SIZE);
 199
 200                 if (pwrite64(fd, label, label_size, label_offset(size, l) +
 201                     (2 * VDEV_PAD_SIZE)) == label_size)
 202                         labels_cleared = B_TRUE;
 203         }
 204
 205         if (clear_l2arc_header) {
 206                 _Static_assert(sizeof (*label) >= sizeof (l2arc_dev_hdr_phys_t),
 207                     "label < l2arc_dev_hdr_phys_t");
 208                 memset(label, 0, sizeof (l2arc_dev_hdr_phys_t));
 209                 if (pwrite64(fd, label, sizeof (l2arc_dev_hdr_phys_t),
 210                     VDEV_LABEL_START_SIZE) == sizeof (l2arc_dev_hdr_phys_t))
 211                         header_cleared = B_TRUE;
 212         }
 213
 214         free(label);
 215
 216         if (!labels_cleared || (clear_l2arc_header && !header_cleared))
 217                 return (-1);
 218
 219         return (0);
 220 }
 221
 222 static boolean_t
 223 find_guid(nvlist_t *nv, uint64_t guid)
 224 {
 225         nvlist_t **child;
 226         uint_t c, children;
 227
 228         if (fnvlist_lookup_uint64(nv, ZPOOL_CONFIG_GUID) == guid)
 229                 return (B_TRUE);
 230
 231         if (nvlist_lookup_nvlist_array(nv, ZPOOL_CONFIG_CHILDREN,
 232             &child, &children) == 0) {
 233                 for (c = 0; c < children; c++)
 234                         if (find_guid(child[c], guid))
 235                                 return (B_TRUE);
 236         }
 237
 238         return (B_FALSE);
 239 }
 240
 241 typedef struct aux_cbdata {
 242         const char      *cb_type;
 243         uint64_t        cb_guid;
 244         zpool_handle_t  *cb_zhp;
 245 } aux_cbdata_t;
 246
 247 static int
 248 find_aux(zpool_handle_t *zhp, void *data)
 249 {
 250         aux_cbdata_t *cbp = data;
 251         nvlist_t **list;
 252         uint_t count;
 253
 254         nvlist_t *nvroot = fnvlist_lookup_nvlist(zhp->zpool_config,
 255             ZPOOL_CONFIG_VDEV_TREE);
 256
 257         if (nvlist_lookup_nvlist_array(nvroot, cbp->cb_type,
 258             &list, &count) == 0) {
 259                 for (uint_t i = 0; i < count; i++) {
 260                         uint64_t guid = fnvlist_lookup_uint64(list[i],
 261                             ZPOOL_CONFIG_GUID);
 262                         if (guid == cbp->cb_guid) {
 263                                 cbp->cb_zhp = zhp;
 264                                 return (1);
 265                         }
 266                 }
 267         }
 268
 269         zpool_close(zhp);
 270         return (0);
 271 }
 272
 273 /*
 274  * Determines if the pool is in use.  If so, it returns true and the state of
 275  * the pool as well as the name of the pool.  Name string is allocated and
 276  * must be freed by the caller.
 277  */
 278 int
 279 zpool_in_use(libzfs_handle_t *hdl, int fd, pool_state_t *state, char **namestr,
 280     boolean_t *inuse)
 281 {
 282         nvlist_t *config;
 283         char *name = NULL;
 284         boolean_t ret;
 285         uint64_t guid = 0, vdev_guid;
 286         zpool_handle_t *zhp;
 287         nvlist_t *pool_config;
 288         uint64_t stateval, isspare;
 289         aux_cbdata_t cb = { 0 };
 290         boolean_t isactive;
 291
 292         *inuse = B_FALSE;
 293
 294         if (zpool_read_label(fd, &config, NULL) != 0) {
 295                 (void) no_memory(hdl);
 296                 return (-1);
 297         }
 298
 299         if (config == NULL)
 300                 return (0);
 301
 302         stateval = fnvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_STATE);
 303         vdev_guid = fnvlist_lookup_uint64(config, ZPOOL_CONFIG_GUID);
 304
 305         if (stateval != POOL_STATE_SPARE && stateval != POOL_STATE_L2CACHE) {
 306                 name = fnvlist_lookup_string(config, ZPOOL_CONFIG_POOL_NAME);
 307                 guid = fnvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_GUID);
 308         }
 309
 310         switch (stateval) {
 311         case POOL_STATE_EXPORTED:
 312                 /*
 313                  * A pool with an exported state may in fact be imported
 314                  * read-only, so check the in-core state to see if it's
 315                  * active and imported read-only.  If it is, set
 316                  * its state to active.
 317                  */
 318                 if (pool_active(hdl, name, guid, &isactive) == 0 && isactive &&
 319                     (zhp = zpool_open_canfail(hdl, name)) != NULL) {
 320                         if (zpool_get_prop_int(zhp, ZPOOL_PROP_READONLY, NULL))
 321                                 stateval = POOL_STATE_ACTIVE;
 322
 323                         /*
 324                          * All we needed the zpool handle for is the
 325                          * readonly prop check.
 326                          */
 327                         zpool_close(zhp);
 328                 }
 329
 330                 ret = B_TRUE;
 331                 break;
 332
 333         case POOL_STATE_ACTIVE:
 334                 /*
 335                  * For an active pool, we have to determine if it's really part
 336                  * of a currently active pool (in which case the pool will exist
 337                  * and the guid will be the same), or whether it's part of an
 338                  * active pool that was disconnected without being explicitly
 339                  * exported.
 340                  */
 341                 if (pool_active(hdl, name, guid, &isactive) != 0) {
 342                         nvlist_free(config);
 343                         return (-1);
 344                 }
 345
 346                 if (isactive) {
 347                         /*
 348                          * Because the device may have been removed while
 349                          * offlined, we only report it as active if the vdev is
 350                          * still present in the config.  Otherwise, pretend like
 351                          * it's not in use.
 352                          */
 353                         if ((zhp = zpool_open_canfail(hdl, name)) != NULL &&
 354                             (pool_config = zpool_get_config(zhp, NULL))
 355                             != NULL) {
 356                                 nvlist_t *nvroot = fnvlist_lookup_nvlist(
 357                                     pool_config, ZPOOL_CONFIG_VDEV_TREE);
 358                                 ret = find_guid(nvroot, vdev_guid);
 359                         } else {
 360                                 ret = B_FALSE;
 361                         }
 362
 363                         /*
 364                          * If this is an active spare within another pool, we
 365                          * treat it like an unused hot spare.  This allows the
 366                          * user to create a pool with a hot spare that currently
 367                          * in use within another pool.  Since we return B_TRUE,
 368                          * libdiskmgt will continue to prevent generic consumers
 369                          * from using the device.
 370                          */
 371                         if (ret && nvlist_lookup_uint64(config,
 372                             ZPOOL_CONFIG_IS_SPARE, &isspare) == 0 && isspare)
 373                                 stateval = POOL_STATE_SPARE;
 374
 375                         if (zhp != NULL)
 376                                 zpool_close(zhp);
 377                 } else {
 378                         stateval = POOL_STATE_POTENTIALLY_ACTIVE;
 379                         ret = B_TRUE;
 380                 }
 381                 break;
 382
 383         case POOL_STATE_SPARE:
 384                 /*
 385                  * For a hot spare, it can be either definitively in use, or
 386                  * potentially active.  To determine if it's in use, we iterate
 387                  * over all pools in the system and search for one with a spare
 388                  * with a matching guid.
 389                  *
 390                  * Due to the shared nature of spares, we don't actually report
 391                  * the potentially active case as in use.  This means the user
 392                  * can freely create pools on the hot spares of exported pools,
 393                  * but to do otherwise makes the resulting code complicated, and
 394                  * we end up having to deal with this case anyway.
 395                  */
 396                 cb.cb_zhp = NULL;
 397                 cb.cb_guid = vdev_guid;
 398                 cb.cb_type = ZPOOL_CONFIG_SPARES;
 399                 if (zpool_iter(hdl, find_aux, &cb) == 1) {
 400                         name = (char *)zpool_get_name(cb.cb_zhp);
 401                         ret = B_TRUE;
 402                 } else {
 403                         ret = B_FALSE;
 404                 }
 405                 break;
 406
 407         case POOL_STATE_L2CACHE:
 408
 409                 /*
 410                  * Check if any pool is currently using this l2cache device.
 411                  */
 412                 cb.cb_zhp = NULL;
 413                 cb.cb_guid = vdev_guid;
 414                 cb.cb_type = ZPOOL_CONFIG_L2CACHE;
 415                 if (zpool_iter(hdl, find_aux, &cb) == 1) {
 416                         name = (char *)zpool_get_name(cb.cb_zhp);
 417                         ret = B_TRUE;
 418                 } else {
 419                         ret = B_FALSE;
 420                 }
 421                 break;
 422
 423         default:
 424                 ret = B_FALSE;
 425         }
 426
 427
 428         if (ret) {
 429                 *namestr = zfs_strdup(hdl, name);
 430                 *state = (pool_state_t)stateval;
 431         }
 432
 433         if (cb.cb_zhp)
 434                 zpool_close(cb.cb_zhp);
 435
 436         nvlist_free(config);
 437         *inuse = ret;
 438         return (0);
 439 }