lib/libzfs/libzfs_iter.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 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 (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
  24  * Copyright (c) 2013, 2019 by Delphix. All rights reserved.
  25  * Copyright 2014 Nexenta Systems, Inc.  All rights reserved.
  26  * Copyright (c) 2019 Datto Inc.
  27  */
  28
  29 #include <stdio.h>
  30 #include <stdlib.h>
  31 #include <strings.h>
  32 #include <unistd.h>
  33 #include <stddef.h>
  34 #include <libintl.h>
  35 #include <libzfs.h>
  36 #include <libzutil.h>
  37 #include <sys/mntent.h>
  38
  39 #include "libzfs_impl.h"
  40
  41 static int
  42 zfs_iter_clones(zfs_handle_t *zhp, zfs_iter_f func, void *data)
  43 {
  44         nvlist_t *nvl = zfs_get_clones_nvl(zhp);
  45         nvpair_t *pair;
  46
  47         if (nvl == NULL)
  48                 return (0);
  49
  50         for (pair = nvlist_next_nvpair(nvl, NULL); pair != NULL;
  51             pair = nvlist_next_nvpair(nvl, pair)) {
  52                 zfs_handle_t *clone = zfs_open(zhp->zfs_hdl, nvpair_name(pair),
  53                     ZFS_TYPE_FILESYSTEM | ZFS_TYPE_VOLUME);
  54                 if (clone != NULL) {
  55                         int err = func(clone, data);
  56                         if (err != 0)
  57                                 return (err);
  58                 }
  59         }
  60         return (0);
  61 }
  62
  63 static int
  64 zfs_do_list_ioctl(zfs_handle_t *zhp, int arg, zfs_cmd_t *zc)
  65 {
  66         int rc;
  67         uint64_t        orig_cookie;
  68
  69         orig_cookie = zc->zc_cookie;
  70 top:
  71         (void) strlcpy(zc->zc_name, zhp->zfs_name, sizeof (zc->zc_name));
  72         rc = zfs_ioctl(zhp->zfs_hdl, arg, zc);
  73
  74         if (rc == -1) {
  75                 switch (errno) {
  76                 case ENOMEM:
  77                         /* expand nvlist memory and try again */
  78                         if (zcmd_expand_dst_nvlist(zhp->zfs_hdl, zc) != 0) {
  79                                 zcmd_free_nvlists(zc);
  80                                 return (-1);
  81                         }
  82                         zc->zc_cookie = orig_cookie;
  83                         goto top;
  84                 /*
  85                  * An errno value of ESRCH indicates normal completion.
  86                  * If ENOENT is returned, then the underlying dataset
  87                  * has been removed since we obtained the handle.
  88                  */
  89                 case ESRCH:
  90                 case ENOENT:
  91                         rc = 1;
  92                         break;
  93                 default:
  94                         rc = zfs_standard_error(zhp->zfs_hdl, errno,
  95                             dgettext(TEXT_DOMAIN,
  96                             "cannot iterate filesystems"));
  97                         break;
  98                 }
  99         }
 100         return (rc);
 101 }
 102
 103 /*
 104  * Iterate over all child filesystems
 105  */
 106 int
 107 zfs_iter_filesystems(zfs_handle_t *zhp, zfs_iter_f func, void *data)
 108 {
 109         zfs_cmd_t zc = {"\0"};
 110         zfs_handle_t *nzhp;
 111         int ret;
 112
 113         if (zhp->zfs_type != ZFS_TYPE_FILESYSTEM)
 114                 return (0);
 115
 116         if (zcmd_alloc_dst_nvlist(zhp->zfs_hdl, &zc, 0) != 0)
 117                 return (-1);
 118
 119         while ((ret = zfs_do_list_ioctl(zhp, ZFS_IOC_DATASET_LIST_NEXT,
 120             &zc)) == 0) {
 121                 /*
 122                  * Silently ignore errors, as the only plausible explanation is
 123                  * that the pool has since been removed.
 124                  */
 125                 if ((nzhp = make_dataset_handle_zc(zhp->zfs_hdl,
 126                     &zc)) == NULL) {
 127                         continue;
 128                 }
 129
 130                 if ((ret = func(nzhp, data)) != 0) {
 131                         zcmd_free_nvlists(&zc);
 132                         return (ret);
 133                 }
 134         }
 135         zcmd_free_nvlists(&zc);
 136         return ((ret < 0) ? ret : 0);
 137 }
 138
 139 /*
 140  * Iterate over all snapshots
 141  */
 142 int
 143 zfs_iter_snapshots(zfs_handle_t *zhp, boolean_t simple, zfs_iter_f func,
 144     void *data, uint64_t min_txg, uint64_t max_txg)
 145 {
 146         zfs_cmd_t zc = {"\0"};
 147         zfs_handle_t *nzhp;
 148         int ret;
 149         nvlist_t *range_nvl = NULL;
 150
 151         if (zhp->zfs_type == ZFS_TYPE_SNAPSHOT ||
 152             zhp->zfs_type == ZFS_TYPE_BOOKMARK)
 153                 return (0);
 154
 155         zc.zc_simple = simple;
 156
 157         if (zcmd_alloc_dst_nvlist(zhp->zfs_hdl, &zc, 0) != 0)
 158                 return (-1);
 159
 160         if (min_txg != 0) {
 161                 range_nvl = fnvlist_alloc();
 162                 fnvlist_add_uint64(range_nvl, SNAP_ITER_MIN_TXG, min_txg);
 163         }
 164         if (max_txg != 0) {
 165                 if (range_nvl == NULL)
 166                         range_nvl = fnvlist_alloc();
 167                 fnvlist_add_uint64(range_nvl, SNAP_ITER_MAX_TXG, max_txg);
 168         }
 169
 170         if (range_nvl != NULL &&
 171             zcmd_write_src_nvlist(zhp->zfs_hdl, &zc, range_nvl) != 0) {
 172                 zcmd_free_nvlists(&zc);
 173                 fnvlist_free(range_nvl);
 174                 return (-1);
 175         }
 176
 177         while ((ret = zfs_do_list_ioctl(zhp, ZFS_IOC_SNAPSHOT_LIST_NEXT,
 178             &zc)) == 0) {
 179
 180                 if (simple)
 181                         nzhp = make_dataset_simple_handle_zc(zhp, &zc);
 182                 else
 183                         nzhp = make_dataset_handle_zc(zhp->zfs_hdl, &zc);
 184                 if (nzhp == NULL)
 185                         continue;
 186
 187                 if ((ret = func(nzhp, data)) != 0) {
 188                         zcmd_free_nvlists(&zc);
 189                         fnvlist_free(range_nvl);
 190                         return (ret);
 191                 }
 192         }
 193         zcmd_free_nvlists(&zc);
 194         fnvlist_free(range_nvl);
 195         return ((ret < 0) ? ret : 0);
 196 }
 197
 198 /*
 199  * Iterate over all bookmarks
 200  */
 201 int
 202 zfs_iter_bookmarks(zfs_handle_t *zhp, zfs_iter_f func, void *data)
 203 {
 204         zfs_handle_t *nzhp;
 205         nvlist_t *props = NULL;
 206         nvlist_t *bmarks = NULL;
 207         int err;
 208         nvpair_t *pair;
 209
 210         if ((zfs_get_type(zhp) & (ZFS_TYPE_SNAPSHOT | ZFS_TYPE_BOOKMARK)) != 0)
 211                 return (0);
 212
 213         /* Setup the requested properties nvlist. */
 214         props = fnvlist_alloc();
 215         for (zfs_prop_t p = 0; p < ZFS_NUM_PROPS; p++) {
 216                 if (zfs_prop_valid_for_type(p, ZFS_TYPE_BOOKMARK, B_FALSE)) {
 217                         fnvlist_add_boolean(props, zfs_prop_to_name(p));
 218                 }
 219         }
 220         fnvlist_add_boolean(props, "redact_complete");
 221
 222         if ((err = lzc_get_bookmarks(zhp->zfs_name, props, &bmarks)) != 0)
 223                 goto out;
 224
 225         for (pair = nvlist_next_nvpair(bmarks, NULL);
 226             pair != NULL; pair = nvlist_next_nvpair(bmarks, pair)) {
 227                 char name[ZFS_MAX_DATASET_NAME_LEN];
 228                 char *bmark_name;
 229                 nvlist_t *bmark_props;
 230
 231                 bmark_name = nvpair_name(pair);
 232                 bmark_props = fnvpair_value_nvlist(pair);
 233
 234                 if (snprintf(name, sizeof (name), "%s#%s", zhp->zfs_name,
 235                     bmark_name) >= sizeof (name)) {
 236                         err = EINVAL;
 237                         goto out;
 238                 }
 239
 240                 nzhp = make_bookmark_handle(zhp, name, bmark_props);
 241                 if (nzhp == NULL)
 242                         continue;
 243
 244                 if ((err = func(nzhp, data)) != 0)
 245                         goto out;
 246         }
 247
 248 out:
 249         fnvlist_free(props);
 250         fnvlist_free(bmarks);
 251
 252         return (err);
 253 }
 254
 255 /*
 256  * Routines for dealing with the sorted snapshot functionality
 257  */
 258 typedef struct zfs_node {
 259         zfs_handle_t    *zn_handle;
 260         avl_node_t      zn_avlnode;
 261 } zfs_node_t;
 262
 263 static int
 264 zfs_sort_snaps(zfs_handle_t *zhp, void *data)
 265 {
 266         avl_tree_t *avl = data;
 267         zfs_node_t *node;
 268         zfs_node_t search;
 269
 270         search.zn_handle = zhp;
 271         node = avl_find(avl, &search, NULL);
 272         if (node) {
 273                 /*
 274                  * If this snapshot was renamed while we were creating the
 275                  * AVL tree, it's possible that we already inserted it under
 276                  * its old name. Remove the old handle before adding the new
 277                  * one.
 278                  */
 279                 zfs_close(node->zn_handle);
 280                 avl_remove(avl, node);
 281                 free(node);
 282         }
 283
 284         node = zfs_alloc(zhp->zfs_hdl, sizeof (zfs_node_t));
 285         node->zn_handle = zhp;
 286         avl_add(avl, node);
 287
 288         return (0);
 289 }
 290
 291 static int
 292 zfs_snapshot_compare(const void *larg, const void *rarg)
 293 {
 294         zfs_handle_t *l = ((zfs_node_t *)larg)->zn_handle;
 295         zfs_handle_t *r = ((zfs_node_t *)rarg)->zn_handle;
 296         uint64_t lcreate, rcreate;
 297
 298         /*
 299          * Sort them according to creation time.  We use the hidden
 300          * CREATETXG property to get an absolute ordering of snapshots.
 301          */
 302         lcreate = zfs_prop_get_int(l, ZFS_PROP_CREATETXG);
 303         rcreate = zfs_prop_get_int(r, ZFS_PROP_CREATETXG);
 304
 305         return (TREE_CMP(lcreate, rcreate));
 306 }
 307
 308 int
 309 zfs_iter_snapshots_sorted(zfs_handle_t *zhp, zfs_iter_f callback, void *data,
 310     uint64_t min_txg, uint64_t max_txg)
 311 {
 312         int ret = 0;
 313         zfs_node_t *node;
 314         avl_tree_t avl;
 315         void *cookie = NULL;
 316
 317         avl_create(&avl, zfs_snapshot_compare,
 318             sizeof (zfs_node_t), offsetof(zfs_node_t, zn_avlnode));
 319
 320         ret = zfs_iter_snapshots(zhp, B_FALSE, zfs_sort_snaps, &avl, min_txg,
 321             max_txg);
 322
 323         for (node = avl_first(&avl); node != NULL; node = AVL_NEXT(&avl, node))
 324                 ret |= callback(node->zn_handle, data);
 325
 326         while ((node = avl_destroy_nodes(&avl, &cookie)) != NULL)
 327                 free(node);
 328
 329         avl_destroy(&avl);
 330
 331         return (ret);
 332 }
 333
 334 typedef struct {
 335         char *ssa_first;
 336         char *ssa_last;
 337         boolean_t ssa_seenfirst;
 338         boolean_t ssa_seenlast;
 339         zfs_iter_f ssa_func;
 340         void *ssa_arg;
 341 } snapspec_arg_t;
 342
 343 static int
 344 snapspec_cb(zfs_handle_t *zhp, void *arg)
 345 {
 346         snapspec_arg_t *ssa = arg;
 347         const char *shortsnapname;
 348         int err = 0;
 349
 350         if (ssa->ssa_seenlast)
 351                 return (0);
 352
 353         shortsnapname = strchr(zfs_get_name(zhp), '@') + 1;
 354         if (!ssa->ssa_seenfirst && strcmp(shortsnapname, ssa->ssa_first) == 0)
 355                 ssa->ssa_seenfirst = B_TRUE;
 356         if (strcmp(shortsnapname, ssa->ssa_last) == 0)
 357                 ssa->ssa_seenlast = B_TRUE;
 358
 359         if (ssa->ssa_seenfirst) {
 360                 err = ssa->ssa_func(zhp, ssa->ssa_arg);
 361         } else {
 362                 zfs_close(zhp);
 363         }
 364
 365         return (err);
 366 }
 367
 368 /*
 369  * spec is a string like "A,B%C,D"
 370  *
 371  * <snaps>, where <snaps> can be:
 372  *      <snap>          (single snapshot)
 373  *      <snap>%<snap>   (range of snapshots, inclusive)
 374  *      %<snap>         (range of snapshots, starting with earliest)
 375  *      <snap>%         (range of snapshots, ending with last)
 376  *      %               (all snapshots)
 377  *      <snaps>[,...]   (comma separated list of the above)
 378  *
 379  * If a snapshot can not be opened, continue trying to open the others, but
 380  * return ENOENT at the end.
 381  */
 382 int
 383 zfs_iter_snapspec(zfs_handle_t *fs_zhp, const char *spec_orig,
 384     zfs_iter_f func, void *arg)
 385 {
 386         char *buf, *comma_separated, *cp;
 387         int err = 0;
 388         int ret = 0;
 389
 390         buf = zfs_strdup(fs_zhp->zfs_hdl, spec_orig);
 391         cp = buf;
 392
 393         while ((comma_separated = strsep(&cp, ",")) != NULL) {
 394                 char *pct = strchr(comma_separated, '%');
 395                 if (pct != NULL) {
 396                         snapspec_arg_t ssa = { 0 };
 397                         ssa.ssa_func = func;
 398                         ssa.ssa_arg = arg;
 399
 400                         if (pct == comma_separated)
 401                                 ssa.ssa_seenfirst = B_TRUE;
 402                         else
 403                                 ssa.ssa_first = comma_separated;
 404                         *pct = '\0';
 405                         ssa.ssa_last = pct + 1;
 406
 407                         /*
 408                          * If there is a lastname specified, make sure it
 409                          * exists.
 410                          */
 411                         if (ssa.ssa_last[0] != '\0') {
 412                                 char snapname[ZFS_MAX_DATASET_NAME_LEN];
 413                                 (void) snprintf(snapname, sizeof (snapname),
 414                                     "%s@%s", zfs_get_name(fs_zhp),
 415                                     ssa.ssa_last);
 416                                 if (!zfs_dataset_exists(fs_zhp->zfs_hdl,
 417                                     snapname, ZFS_TYPE_SNAPSHOT)) {
 418                                         ret = ENOENT;
 419                                         continue;
 420                                 }
 421                         }
 422
 423                         err = zfs_iter_snapshots_sorted(fs_zhp,
 424                             snapspec_cb, &ssa, 0, 0);
 425                         if (ret == 0)
 426                                 ret = err;
 427                         if (ret == 0 && (!ssa.ssa_seenfirst ||
 428                             (ssa.ssa_last[0] != '\0' && !ssa.ssa_seenlast))) {
 429                                 ret = ENOENT;
 430                         }
 431                 } else {
 432                         char snapname[ZFS_MAX_DATASET_NAME_LEN];
 433                         zfs_handle_t *snap_zhp;
 434                         (void) snprintf(snapname, sizeof (snapname), "%s@%s",
 435                             zfs_get_name(fs_zhp), comma_separated);
 436                         snap_zhp = make_dataset_handle(fs_zhp->zfs_hdl,
 437                             snapname);
 438                         if (snap_zhp == NULL) {
 439                                 ret = ENOENT;
 440                                 continue;
 441                         }
 442                         err = func(snap_zhp, arg);
 443                         if (ret == 0)
 444                                 ret = err;
 445                 }
 446         }
 447
 448         free(buf);
 449         return (ret);
 450 }
 451
 452 /*
 453  * Iterate over all children, snapshots and filesystems
 454  * Process snapshots before filesystems because they are nearer the input
 455  * handle: this is extremely important when used with zfs_iter_f functions
 456  * looking for data, following the logic that we would like to find it as soon
 457  * and as close as possible.
 458  */
 459 int
 460 zfs_iter_children(zfs_handle_t *zhp, zfs_iter_f func, void *data)
 461 {
 462         int ret;
 463
 464         if ((ret = zfs_iter_snapshots(zhp, B_FALSE, func, data, 0, 0)) != 0)
 465                 return (ret);
 466
 467         return (zfs_iter_filesystems(zhp, func, data));
 468 }
 469
 470
 471 typedef struct iter_stack_frame {
 472         struct iter_stack_frame *next;
 473         zfs_handle_t *zhp;
 474 } iter_stack_frame_t;
 475
 476 typedef struct iter_dependents_arg {
 477         boolean_t first;
 478         boolean_t allowrecursion;
 479         iter_stack_frame_t *stack;
 480         zfs_iter_f func;
 481         void *data;
 482 } iter_dependents_arg_t;
 483
 484 static int
 485 iter_dependents_cb(zfs_handle_t *zhp, void *arg)
 486 {
 487         iter_dependents_arg_t *ida = arg;
 488         int err = 0;
 489         boolean_t first = ida->first;
 490         ida->first = B_FALSE;
 491
 492         if (zhp->zfs_type == ZFS_TYPE_SNAPSHOT) {
 493                 err = zfs_iter_clones(zhp, iter_dependents_cb, ida);
 494         } else if (zhp->zfs_type != ZFS_TYPE_BOOKMARK) {
 495                 iter_stack_frame_t isf;
 496                 iter_stack_frame_t *f;
 497
 498                 /*
 499                  * check if there is a cycle by seeing if this fs is already
 500                  * on the stack.
 501                  */
 502                 for (f = ida->stack; f != NULL; f = f->next) {
 503                         if (f->zhp->zfs_dmustats.dds_guid ==
 504                             zhp->zfs_dmustats.dds_guid) {
 505                                 if (ida->allowrecursion) {
 506                                         zfs_close(zhp);
 507                                         return (0);
 508                                 } else {
 509                                         zfs_error_aux(zhp->zfs_hdl,
 510                                             dgettext(TEXT_DOMAIN,
 511                                             "recursive dependency at '%s'"),
 512                                             zfs_get_name(zhp));
 513                                         err = zfs_error(zhp->zfs_hdl,
 514                                             EZFS_RECURSIVE,
 515                                             dgettext(TEXT_DOMAIN,
 516                                             "cannot determine dependent "
 517                                             "datasets"));
 518                                         zfs_close(zhp);
 519                                         return (err);
 520                                 }
 521                         }
 522                 }
 523
 524                 isf.zhp = zhp;
 525                 isf.next = ida->stack;
 526                 ida->stack = &isf;
 527                 err = zfs_iter_filesystems(zhp, iter_dependents_cb, ida);
 528                 if (err == 0)
 529                         err = zfs_iter_snapshots(zhp, B_FALSE,
 530                             iter_dependents_cb, ida, 0, 0);
 531                 ida->stack = isf.next;
 532         }
 533
 534         if (!first && err == 0)
 535                 err = ida->func(zhp, ida->data);
 536         else
 537                 zfs_close(zhp);
 538
 539         return (err);
 540 }
 541
 542 int
 543 zfs_iter_dependents(zfs_handle_t *zhp, boolean_t allowrecursion,
 544     zfs_iter_f func, void *data)
 545 {
 546         iter_dependents_arg_t ida;
 547         ida.allowrecursion = allowrecursion;
 548         ida.stack = NULL;
 549         ida.func = func;
 550         ida.data = data;
 551         ida.first = B_TRUE;
 552         return (iter_dependents_cb(zfs_handle_dup(zhp), &ida));
 553 }
 554
 555 /*
 556  * Iterate over mounted children of the specified dataset
 557  */
 558 int
 559 zfs_iter_mounted(zfs_handle_t *zhp, zfs_iter_f func, void *data)
 560 {
 561         char mnt_prop[ZFS_MAXPROPLEN];
 562         struct mnttab entry;
 563         zfs_handle_t *mtab_zhp;
 564         size_t namelen = strlen(zhp->zfs_name);
 565         FILE *mnttab;
 566         int err = 0;
 567
 568         if ((mnttab = fopen(MNTTAB, "re")) == NULL)
 569                 return (ENOENT);
 570
 571         while (err == 0 && getmntent(mnttab, &entry) == 0) {
 572                 /* Ignore non-ZFS entries */
 573                 if (strcmp(entry.mnt_fstype, MNTTYPE_ZFS) != 0)
 574                         continue;
 575
 576                 /* Ignore datasets not within the provided dataset */
 577                 if (strncmp(entry.mnt_special, zhp->zfs_name, namelen) != 0 ||
 578                     entry.mnt_special[namelen] != '/')
 579                         continue;
 580
 581                 /* Skip snapshot of any child dataset */
 582                 if (strchr(entry.mnt_special, '@') != NULL)
 583                         continue;
 584
 585                 if ((mtab_zhp = zfs_open(zhp->zfs_hdl, entry.mnt_special,
 586                     ZFS_TYPE_FILESYSTEM)) == NULL)
 587                         continue;
 588
 589                 /* Ignore legacy mounts as they are user managed */
 590                 verify(zfs_prop_get(mtab_zhp, ZFS_PROP_MOUNTPOINT, mnt_prop,
 591                     sizeof (mnt_prop), NULL, NULL, 0, B_FALSE) == 0);
 592                 if (strcmp(mnt_prop, "legacy") == 0) {
 593                         zfs_close(mtab_zhp);
 594                         continue;
 595                 }
 596
 597                 err = func(mtab_zhp, data);
 598         }
 599
 600         fclose(mnttab);
 601
 602         return (err);
 603 }