contrib/lvm2/dist/tools/vgsplit.c

   1 /*      $NetBSD: vgsplit.c,v 1.1.1.2 2009/12/02 00:25:46 haad Exp $     */
   2
   3 /*
   4  * Copyright (C) 2001-2004 Sistina Software, Inc. All rights reserved.
   5  * Copyright (C) 2004-2009 Red Hat, Inc. All rights reserved.
   6  *
   7  * This file is part of LVM2.
   8  *
   9  * This copyrighted material is made available to anyone wishing to use,
  10  * modify, copy, or redistribute it subject to the terms and conditions
  11  * of the GNU Lesser General Public License v.2.1.
  12  *
  13  * You should have received a copy of the GNU Lesser General Public License
  14  * along with this program; if not, write to the Free Software Foundation,
  15  * Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  16  */
  17
  18 #include "tools.h"
  19
  20 /* FIXME Why not (lv->vg == vg) ? */
  21 static int _lv_is_in_vg(struct volume_group *vg, struct logical_volume *lv)
  22 {
  23         struct lv_list *lvl;
  24
  25         dm_list_iterate_items(lvl, &vg->lvs)
  26                 if (lv == lvl->lv)
  27                          return 1;
  28
  29         return 0;
  30 }
  31
  32 static int _move_one_lv(struct volume_group *vg_from,
  33                          struct volume_group *vg_to,
  34                          struct dm_list *lvh)
  35 {
  36         struct logical_volume *lv = dm_list_item(lvh, struct lv_list)->lv;
  37
  38         dm_list_move(&vg_to->lvs, lvh);
  39
  40         if (lv_is_active(lv)) {
  41                 log_error("Logical volume \"%s\" must be inactive", lv->name);
  42                 return 0;
  43         }
  44
  45         return 1;
  46 }
  47
  48 static int _move_lvs(struct volume_group *vg_from, struct volume_group *vg_to)
  49 {
  50         struct dm_list *lvh, *lvht;
  51         struct logical_volume *lv;
  52         struct lv_segment *seg;
  53         struct physical_volume *pv;
  54         struct volume_group *vg_with;
  55         unsigned s;
  56
  57         dm_list_iterate_safe(lvh, lvht, &vg_from->lvs) {
  58                 lv = dm_list_item(lvh, struct lv_list)->lv;
  59
  60                 if ((lv->status & SNAPSHOT))
  61                         continue;
  62
  63                 if ((lv->status & MIRRORED))
  64                         continue;
  65
  66                 /* Ensure all the PVs used by this LV remain in the same */
  67                 /* VG as each other */
  68                 vg_with = NULL;
  69                 dm_list_iterate_items(seg, &lv->segments) {
  70                         for (s = 0; s < seg->area_count; s++) {
  71                                 /* FIXME Check AREA_LV too */
  72                                 if (seg_type(seg, s) != AREA_PV)
  73                                         continue;
  74
  75                                 pv = seg_pv(seg, s);
  76                                 if (vg_with) {
  77                                         if (!pv_is_in_vg(vg_with, pv)) {
  78                                                 log_error("Can't split Logical "
  79                                                           "Volume %s between "
  80                                                           "two Volume Groups",
  81                                                           lv->name);
  82                                                 return 0;
  83                                         }
  84                                         continue;
  85                                 }
  86
  87                                 if (pv_is_in_vg(vg_from, pv)) {
  88                                         vg_with = vg_from;
  89                                         continue;
  90                                 }
  91                                 if (pv_is_in_vg(vg_to, pv)) {
  92                                         vg_with = vg_to;
  93                                         continue;
  94                                 }
  95                                 log_error("Physical Volume %s not found",
  96                                           pv_dev_name(pv));
  97                                 return 0;
  98                         }
  99
 100                 }
 101
 102                 if (vg_with == vg_from)
 103                         continue;
 104
 105                 /* Move this LV */
 106                 if (!_move_one_lv(vg_from, vg_to, lvh))
 107                         return_0;
 108         }
 109
 110         /* FIXME Ensure no LVs contain segs pointing at LVs in the other VG */
 111
 112         return 1;
 113 }
 114
 115 /*
 116  * Move the hidden / internal "snapshotN" LVs.from 'vg_from' to 'vg_to'.
 117  */
 118 static int _move_snapshots(struct volume_group *vg_from,
 119                            struct volume_group *vg_to)
 120 {
 121         struct dm_list *lvh, *lvht;
 122         struct logical_volume *lv;
 123         struct lv_segment *seg;
 124         int cow_from = 0;
 125         int origin_from = 0;
 126
 127         dm_list_iterate_safe(lvh, lvht, &vg_from->lvs) {
 128                 lv = dm_list_item(lvh, struct lv_list)->lv;
 129
 130                 if (!(lv->status & SNAPSHOT))
 131                         continue;
 132
 133                 dm_list_iterate_items(seg, &lv->segments) {
 134                         cow_from = _lv_is_in_vg(vg_from, seg->cow);
 135                         origin_from = _lv_is_in_vg(vg_from, seg->origin);
 136
 137                         if (cow_from && origin_from)
 138                                 continue;
 139                         if ((!cow_from && origin_from) ||
 140                              (cow_from && !origin_from)) {
 141                                 log_error("Can't split snapshot %s between"
 142                                           " two Volume Groups", seg->cow->name);
 143                                 return 0;
 144                         }
 145
 146                         /*
 147                          * At this point, the cow and origin should already be
 148                          * in vg_to.
 149                          */
 150                         if (_lv_is_in_vg(vg_to, seg->cow) &&
 151                             _lv_is_in_vg(vg_to, seg->origin)) {
 152                                 if (!_move_one_lv(vg_from, vg_to, lvh))
 153                                         return_0;
 154                         }
 155                 }
 156
 157         }
 158
 159         return 1;
 160 }
 161
 162 static int _move_mirrors(struct volume_group *vg_from,
 163                          struct volume_group *vg_to)
 164 {
 165         struct dm_list *lvh, *lvht;
 166         struct logical_volume *lv;
 167         struct lv_segment *seg;
 168         unsigned s, seg_in, log_in;
 169
 170         dm_list_iterate_safe(lvh, lvht, &vg_from->lvs) {
 171                 lv = dm_list_item(lvh, struct lv_list)->lv;
 172
 173                 if (!(lv->status & MIRRORED))
 174                         continue;
 175
 176                 seg = first_seg(lv);
 177
 178                 seg_in = 0;
 179                 for (s = 0; s < seg->area_count; s++)
 180                         if (_lv_is_in_vg(vg_to, seg_lv(seg, s)))
 181                             seg_in++;
 182
 183                 log_in = (!seg->log_lv || _lv_is_in_vg(vg_to, seg->log_lv));
 184
 185                 if ((seg_in && seg_in < seg->area_count) ||
 186                     (seg_in && seg->log_lv && !log_in) ||
 187                     (!seg_in && seg->log_lv && log_in)) {
 188                         log_error("Can't split mirror %s between "
 189                                   "two Volume Groups", lv->name);
 190                         return 0;
 191                 }
 192
 193                 if (seg_in == seg->area_count && log_in) {
 194                         if (!_move_one_lv(vg_from, vg_to, lvh))
 195                                 return_0;
 196                 }
 197         }
 198
 199         return 1;
 200 }
 201
 202 /*
 203  * Create or open the destination of the vgsplit operation.
 204  * Returns
 205  * - non-NULL: VG handle w/VG lock held
 206  * - NULL: no VG lock held
 207  */
 208 static struct volume_group *_vgsplit_to(struct cmd_context *cmd,
 209                                         const char *vg_name_to,
 210                                         int *existing_vg)
 211 {
 212         struct volume_group *vg_to = NULL;
 213
 214         log_verbose("Checking for new volume group \"%s\"", vg_name_to);
 215         /*
 216          * First try to create a new VG.  If we cannot create it,
 217          * and we get FAILED_EXIST (we will not be holding a lock),
 218          * a VG must already exist with this name.  We then try to
 219          * read the existing VG - the vgsplit will be into an existing VG.
 220          *
 221          * Otherwise, if the lock was successful, it must be the case that
 222          * we obtained a WRITE lock and could not find the vgname in the
 223          * system.  Thus, the split will be into a new VG.
 224          */
 225         vg_to = vg_create(cmd, vg_name_to);
 226         if (vg_read_error(vg_to) == FAILED_LOCKING) {
 227                 log_error("Can't get lock for %s", vg_name_to);
 228                 vg_release(vg_to);
 229                 return NULL;
 230         }
 231         if (vg_read_error(vg_to) == FAILED_EXIST) {
 232                 *existing_vg = 1;
 233                 vg_release(vg_to);
 234                 vg_to = vg_read_for_update(cmd, vg_name_to, NULL, 0);
 235
 236                 if (vg_read_error(vg_to)) {
 237                         vg_release(vg_to);
 238                         stack;
 239                         return NULL;
 240                 }
 241
 242         } else if (vg_read_error(vg_to) == SUCCESS) {
 243                 *existing_vg = 0;
 244         }
 245         return vg_to;
 246 }
 247
 248 /*
 249  * Open the source of the vgsplit operation.
 250  * Returns
 251  * - non-NULL: VG handle w/VG lock held
 252  * - NULL: no VG lock held
 253  */
 254 static struct volume_group *_vgsplit_from(struct cmd_context *cmd,
 255                                           const char *vg_name_from)
 256 {
 257         struct volume_group *vg_from;
 258
 259         log_verbose("Checking for volume group \"%s\"", vg_name_from);
 260
 261         vg_from = vg_read_for_update(cmd, vg_name_from, NULL, 0);
 262         if (vg_read_error(vg_from)) {
 263                 vg_release(vg_from);
 264                 return NULL;
 265         }
 266         return vg_from;
 267 }
 268
 269 /*
 270  * Has the user given an option related to a new vg as the split destination?
 271  */
 272 static int new_vg_option_specified(struct cmd_context *cmd)
 273 {
 274         return(arg_count(cmd, clustered_ARG) ||
 275                arg_count(cmd, alloc_ARG) ||
 276                arg_count(cmd, maxphysicalvolumes_ARG) ||
 277                arg_count(cmd, maxlogicalvolumes_ARG));
 278 }
 279
 280 int vgsplit(struct cmd_context *cmd, int argc, char **argv)
 281 {
 282         struct vgcreate_params vp_new;
 283         struct vgcreate_params vp_def;
 284         char *vg_name_from, *vg_name_to;
 285         struct volume_group *vg_to = NULL, *vg_from = NULL;
 286         int opt;
 287         int existing_vg = 0;
 288         int r = ECMD_FAILED;
 289         const char *lv_name;
 290         int lock_vg_from_first = 1;
 291
 292         if ((arg_count(cmd, name_ARG) + argc) < 3) {
 293                 log_error("Existing VG, new VG and either physical volumes "
 294                           "or logical volume required.");
 295                 return EINVALID_CMD_LINE;
 296         }
 297
 298         if (arg_count(cmd, name_ARG) && (argc > 2)) {
 299                 log_error("A logical volume name cannot be given with "
 300                           "physical volumes.");
 301                 return ECMD_FAILED;
 302         }
 303
 304         if (arg_count(cmd, name_ARG))
 305                 lv_name = arg_value(cmd, name_ARG);
 306         else
 307                 lv_name = NULL;
 308
 309         vg_name_from = skip_dev_dir(cmd, argv[0], NULL);
 310         vg_name_to = skip_dev_dir(cmd, argv[1], NULL);
 311         argc -= 2;
 312         argv += 2;
 313
 314         if (!strcmp(vg_name_to, vg_name_from)) {
 315                 log_error("Duplicate volume group name \"%s\"", vg_name_from);
 316                 return ECMD_FAILED;
 317         }
 318
 319         if (strcmp(vg_name_to, vg_name_from) < 0)
 320                 lock_vg_from_first = 0;
 321
 322         if (lock_vg_from_first) {
 323                 vg_from = _vgsplit_from(cmd, vg_name_from);
 324                 if (!vg_from) {
 325                         stack;
 326                         return ECMD_FAILED;
 327                 }
 328                 /*
 329                  * Set metadata format of original VG.
 330                  * NOTE: We must set the format before calling vg_create()
 331                  * since vg_create() calls the per-format constructor.
 332                  */
 333                 cmd->fmt = vg_from->fid->fmt;
 334
 335                 vg_to = _vgsplit_to(cmd, vg_name_to, &existing_vg);
 336                 if (!vg_to) {
 337                         unlock_and_release_vg(cmd, vg_from, vg_name_from);
 338                         stack;
 339                         return ECMD_FAILED;
 340                 }
 341         } else {
 342                 vg_to = _vgsplit_to(cmd, vg_name_to, &existing_vg);
 343                 if (!vg_to) {
 344                         stack;
 345                         return ECMD_FAILED;
 346                 }
 347                 vg_from = _vgsplit_from(cmd, vg_name_from);
 348                 if (!vg_from) {
 349                         unlock_and_release_vg(cmd, vg_to, vg_name_to);
 350                         stack;
 351                         return ECMD_FAILED;
 352                 }
 353
 354                 if (cmd->fmt != vg_from->fid->fmt) {
 355                         /* In this case we don't know the vg_from->fid->fmt */
 356                         log_error("Unable to set new VG metadata type based on "
 357                                   "source VG format - use -M option.");
 358                         goto bad;
 359                 }
 360         }
 361
 362         if (existing_vg) {
 363                 if (new_vg_option_specified(cmd)) {
 364                         log_error("Volume group \"%s\" exists, but new VG "
 365                                     "option specified", vg_name_to);
 366                         goto bad;
 367                 }
 368                 if (!vgs_are_compatible(cmd, vg_from,vg_to))
 369                         goto_bad;
 370         } else {
 371                 vgcreate_params_set_defaults(&vp_def, vg_from);
 372                 vp_def.vg_name = vg_name_to;
 373                 if (vgcreate_params_set_from_args(cmd, &vp_new, &vp_def)) {
 374                         r = EINVALID_CMD_LINE;
 375                         goto_bad;
 376                 }
 377
 378                 if (vgcreate_params_validate(cmd, &vp_new)) {
 379                         r = EINVALID_CMD_LINE;
 380                         goto_bad;
 381                 }
 382
 383                 if (!vg_set_extent_size(vg_to, vp_new.extent_size) ||
 384                     !vg_set_max_lv(vg_to, vp_new.max_lv) ||
 385                     !vg_set_max_pv(vg_to, vp_new.max_pv) ||
 386                     !vg_set_alloc_policy(vg_to, vp_new.alloc) ||
 387                     !vg_set_clustered(vg_to, vp_new.clustered))
 388                         goto_bad;
 389         }
 390
 391         /* Archive vg_from before changing it */
 392         if (!archive(vg_from))
 393                 goto_bad;
 394
 395         /* Move PVs across to new structure */
 396         for (opt = 0; opt < argc; opt++) {
 397                 if (!move_pv(vg_from, vg_to, argv[opt]))
 398                         goto_bad;
 399         }
 400
 401         /* If an LV given on the cmdline, move used_by PVs */
 402         if (lv_name && !move_pvs_used_by_lv(vg_from, vg_to, lv_name))
 403                 goto_bad;
 404
 405         /* Move required LVs across, checking consistency */
 406         if (!(_move_lvs(vg_from, vg_to)))
 407                 goto_bad;
 408
 409         /* FIXME Separate the 'move' from the 'validation' to fix dev stacks */
 410         /* Move required mirrors across */
 411         if (!(_move_mirrors(vg_from, vg_to)))
 412                 goto_bad;
 413
 414         /* Move required snapshots across */
 415         if (!(_move_snapshots(vg_from, vg_to)))
 416                 goto_bad;
 417
 418         /* Split metadata areas and check if both vgs have at least one area */
 419         if (!(vg_split_mdas(cmd, vg_from, vg_to)) && vg_from->pv_count) {
 420                 log_error("Cannot split: Nowhere to store metadata for new Volume Group");
 421                 goto bad;
 422         }
 423
 424         /* Set proper name for all PVs in new VG */
 425         if (!vg_rename(cmd, vg_to, vg_name_to))
 426                 goto_bad;
 427
 428         /* store it on disks */
 429         log_verbose("Writing out updated volume groups");
 430
 431         /*
 432          * First, write out the new VG as EXPORTED.  We do this first in case
 433          * there is a crash - we will still have the new VG information, in an
 434          * exported state.  Recovery after this point would be removal of the
 435          * new VG and redoing the vgsplit.
 436          * FIXME: recover automatically or instruct the user?
 437          */
 438         vg_to->status |= EXPORTED_VG;
 439
 440         if (!archive(vg_to))
 441                 goto_bad;
 442
 443         if (!vg_write(vg_to) || !vg_commit(vg_to))
 444                 goto_bad;
 445
 446         backup(vg_to);
 447
 448         /*
 449          * Next, write out the updated old VG.  If we crash after this point,
 450          * recovery is a vgimport on the new VG.
 451          * FIXME: recover automatically or instruct the user?
 452          */
 453         if (vg_from->pv_count) {
 454                 if (!vg_write(vg_from) || !vg_commit(vg_from))
 455                         goto_bad;
 456
 457                 backup(vg_from);
 458         }
 459
 460         /*
 461          * Finally, remove the EXPORTED flag from the new VG and write it out.
 462          */
 463         if (!test_mode()) {
 464                 vg_release(vg_to);
 465                 vg_to = vg_read_for_update(cmd, vg_name_to, NULL,
 466                                            READ_ALLOW_EXPORTED);
 467                 if (vg_read_error(vg_to)) {
 468                         log_error("Volume group \"%s\" became inconsistent: "
 469                                   "please fix manually", vg_name_to);
 470                         goto bad;
 471                 }
 472         }
 473
 474         vg_to->status &= ~EXPORTED_VG;
 475
 476         if (!vg_write(vg_to) || !vg_commit(vg_to))
 477                 goto_bad;
 478
 479         backup(vg_to);
 480
 481         log_print("%s volume group \"%s\" successfully split from \"%s\"",
 482                   existing_vg ? "Existing" : "New",
 483                   vg_to->name, vg_from->name);
 484
 485         r = ECMD_PROCESSED;
 486
 487 bad:
 488         if (lock_vg_from_first) {
 489                 unlock_and_release_vg(cmd, vg_to, vg_name_to);
 490                 unlock_and_release_vg(cmd, vg_from, vg_name_from);
 491         } else {
 492                 unlock_and_release_vg(cmd, vg_from, vg_name_from);
 493                 unlock_and_release_vg(cmd, vg_to, vg_name_to);
 494         }
 495         return r;
 496 }