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 2010 Nexenta Systems, Inc. All rights reserved.
  25  * Copyright (c) 2011 by Delphix. All rights reserved.
  26  */
  27 
  28 #include <stdio.h>
  29 #include <stdlib.h>
  30 #include <strings.h>
  31 #include <unistd.h>
  32 #include <stddef.h>
  33 #include <libintl.h>
  34 #include <libzfs.h>
  35 
  36 #include "libzfs_impl.h"
  37 
  38 int
  39 zfs_iter_clones(zfs_handle_t *zhp, zfs_iter_f func, void *data)
  40 {
  41         nvlist_t *nvl = zfs_get_clones_nvl(zhp);
  42         nvpair_t *pair;
  43 
  44         if (nvl == NULL)
  45                 return (0);
  46 
  47         for (pair = nvlist_next_nvpair(nvl, NULL); pair != NULL;
  48             pair = nvlist_next_nvpair(nvl, pair)) {
  49                 zfs_handle_t *clone = zfs_open(zhp->zfs_hdl, nvpair_name(pair),
  50                     ZFS_TYPE_FILESYSTEM | ZFS_TYPE_VOLUME);
  51                 if (clone != NULL) {
  52                         int err = func(clone, data);
  53                         if (err != 0)
  54                                 return (err);
  55                 }
  56         }
  57         return (0);
  58 }
  59 
  60 static int
  61 zfs_do_list_ioctl(zfs_handle_t *zhp, int arg, zfs_cmd_t *zc)
  62 {
  63         int rc;
  64         uint64_t        orig_cookie;
  65 
  66         orig_cookie = zc->zc_cookie;
  67 top:
  68         (void) strlcpy(zc->zc_name, zhp->zfs_name, sizeof (zc->zc_name));
  69         rc = ioctl(zhp->zfs_hdl->libzfs_fd, arg, zc);
  70 
  71         if (rc == -1) {
  72                 switch (errno) {
  73                 case ENOMEM:
  74                         /* expand nvlist memory and try again */
  75                         if (zcmd_expand_dst_nvlist(zhp->zfs_hdl, zc) != 0) {
  76                                 zcmd_free_nvlists(zc);
  77                                 return (-1);
  78                         }
  79                         zc->zc_cookie = orig_cookie;
  80                         goto top;
  81                 /*
  82                  * An errno value of ESRCH indicates normal completion.
  83                  * If ENOENT is returned, then the underlying dataset
  84                  * has been removed since we obtained the handle.
  85                  */
  86                 case ESRCH:
  87                 case ENOENT:
  88                         rc = 1;
  89                         break;
  90                 default:
  91                         rc = zfs_standard_error(zhp->zfs_hdl, errno,
  92                             dgettext(TEXT_DOMAIN,
  93                             "cannot iterate filesystems"));
  94                         break;
  95                 }
  96         }
  97         return (rc);
  98 }
  99 
 100 /*
 101  * Iterate over all child filesystems
 102  */
 103 int
 104 zfs_iter_filesystems(zfs_handle_t *zhp, zfs_iter_f func, void *data)
 105 {
 106         zfs_cmd_t zc = { 0 };
 107         zfs_handle_t *nzhp;
 108         int ret;
 109 
 110         if (zhp->zfs_type != ZFS_TYPE_FILESYSTEM)
 111                 return (0);
 112 
 113         if (zcmd_alloc_dst_nvlist(zhp->zfs_hdl, &zc, 0) != 0)
 114                 return (-1);
 115 
 116         while ((ret = zfs_do_list_ioctl(zhp, ZFS_IOC_DATASET_LIST_NEXT,
 117             &zc)) == 0) {
 118                 /*
 119                  * Silently ignore errors, as the only plausible explanation is
 120                  * that the pool has since been removed.
 121                  */
 122                 if ((nzhp = make_dataset_handle_zc(zhp->zfs_hdl,
 123                     &zc)) == NULL) {
 124                         continue;
 125                 }
 126 
 127                 if ((ret = func(nzhp, data)) != 0) {
 128                         zcmd_free_nvlists(&zc);
 129                         return (ret);
 130                 }
 131         }
 132         zcmd_free_nvlists(&zc);
 133         return ((ret < 0) ? ret : 0);
 134 }
 135 
 136 /*
 137  * Iterate over all snapshots
 138  */
 139 int
 140 zfs_iter_snapshots(zfs_handle_t *zhp, zfs_iter_f func, void *data)
 141 {
 142         zfs_cmd_t zc = { 0 };
 143         zfs_handle_t *nzhp;
 144         int ret;
 145 
 146         if (zhp->zfs_type == ZFS_TYPE_SNAPSHOT)
 147                 return (0);
 148 
 149         if (zcmd_alloc_dst_nvlist(zhp->zfs_hdl, &zc, 0) != 0)
 150                 return (-1);
 151         while ((ret = zfs_do_list_ioctl(zhp, ZFS_IOC_SNAPSHOT_LIST_NEXT,
 152             &zc)) == 0) {
 153 
 154                 if ((nzhp = make_dataset_handle_zc(zhp->zfs_hdl,
 155                     &zc)) == NULL) {
 156                         continue;
 157                 }
 158 
 159                 if ((ret = func(nzhp, data)) != 0) {
 160                         zcmd_free_nvlists(&zc);
 161                         return (ret);
 162                 }
 163         }
 164         zcmd_free_nvlists(&zc);
 165         return ((ret < 0) ? ret : 0);
 166 }
 167 
 168 /*
 169  * Routines for dealing with the sorted snapshot functionality
 170  */
 171 typedef struct zfs_node {
 172         zfs_handle_t    *zn_handle;
 173         avl_node_t      zn_avlnode;
 174 } zfs_node_t;
 175 
 176 static int
 177 zfs_sort_snaps(zfs_handle_t *zhp, void *data)
 178 {
 179         avl_tree_t *avl = data;
 180         zfs_node_t *node;
 181         zfs_node_t search;
 182 
 183         search.zn_handle = zhp;
 184         node = avl_find(avl, &search, NULL);
 185         if (node) {
 186                 /*
 187                  * If this snapshot was renamed while we were creating the
 188                  * AVL tree, it's possible that we already inserted it under
 189                  * its old name. Remove the old handle before adding the new
 190                  * one.
 191                  */
 192                 zfs_close(node->zn_handle);
 193                 avl_remove(avl, node);
 194                 free(node);
 195         }
 196 
 197         node = zfs_alloc(zhp->zfs_hdl, sizeof (zfs_node_t));
 198         node->zn_handle = zhp;
 199         avl_add(avl, node);
 200 
 201         return (0);
 202 }
 203 
 204 static int
 205 zfs_snapshot_compare(const void *larg, const void *rarg)
 206 {
 207         zfs_handle_t *l = ((zfs_node_t *)larg)->zn_handle;
 208         zfs_handle_t *r = ((zfs_node_t *)rarg)->zn_handle;
 209         uint64_t lcreate, rcreate;
 210 
 211         /*
 212          * Sort them according to creation time.  We use the hidden
 213          * CREATETXG property to get an absolute ordering of snapshots.
 214          */
 215         lcreate = zfs_prop_get_int(l, ZFS_PROP_CREATETXG);
 216         rcreate = zfs_prop_get_int(r, ZFS_PROP_CREATETXG);
 217 
 218         if (lcreate < rcreate)
 219                 return (-1);
 220         else if (lcreate > rcreate)
 221                 return (+1);
 222         else
 223                 return (0);
 224 }
 225 
 226 int
 227 zfs_iter_snapshots_sorted(zfs_handle_t *zhp, zfs_iter_f callback, void *data)
 228 {
 229         int ret = 0;
 230         zfs_node_t *node;
 231         avl_tree_t avl;
 232         void *cookie = NULL;
 233 
 234         avl_create(&avl, zfs_snapshot_compare,
 235             sizeof (zfs_node_t), offsetof(zfs_node_t, zn_avlnode));
 236 
 237         ret = zfs_iter_snapshots(zhp, zfs_sort_snaps, &avl);
 238 
 239         for (node = avl_first(&avl); node != NULL; node = AVL_NEXT(&avl, node))
 240                 ret |= callback(node->zn_handle, data);
 241 
 242         while ((node = avl_destroy_nodes(&avl, &cookie)) != NULL)
 243                 free(node);
 244 
 245         avl_destroy(&avl);
 246 
 247         return (ret);
 248 }
 249 
 250 typedef struct {
 251         char *ssa_first;
 252         char *ssa_last;
 253         boolean_t ssa_seenfirst;
 254         boolean_t ssa_seenlast;
 255         zfs_iter_f ssa_func;
 256         void *ssa_arg;
 257 } snapspec_arg_t;
 258 
 259 static int
 260 snapspec_cb(zfs_handle_t *zhp, void *arg) {
 261         snapspec_arg_t *ssa = arg;
 262         char *shortsnapname;
 263         int err = 0;
 264 
 265         if (ssa->ssa_seenlast)
 266                 return (0);
 267         shortsnapname = zfs_strdup(zhp->zfs_hdl,
 268             strchr(zfs_get_name(zhp), '@') + 1);
 269 
 270         if (!ssa->ssa_seenfirst && strcmp(shortsnapname, ssa->ssa_first) == 0)
 271                 ssa->ssa_seenfirst = B_TRUE;
 272 
 273         if (ssa->ssa_seenfirst) {
 274                 err = ssa->ssa_func(zhp, ssa->ssa_arg);
 275         } else {
 276                 zfs_close(zhp);
 277         }
 278 
 279         if (strcmp(shortsnapname, ssa->ssa_last) == 0)
 280                 ssa->ssa_seenlast = B_TRUE;
 281         free(shortsnapname);
 282 
 283         return (err);
 284 }
 285 
 286 /*
 287  * spec is a string like "A,B%C,D"
 288  *
 289  * <snaps>, where <snaps> can be:
 290  *      <snap>          (single snapshot)
 291  *      <snap>%<snap>   (range of snapshots, inclusive)
 292  *      %<snap>         (range of snapshots, starting with earliest)
 293  *      <snap>%         (range of snapshots, ending with last)
 294  *      %               (all snapshots)
 295  *      <snaps>[,...]   (comma separated list of the above)
 296  *
 297  * If a snapshot can not be opened, continue trying to open the others, but
 298  * return ENOENT at the end.
 299  */
 300 int
 301 zfs_iter_snapspec(zfs_handle_t *fs_zhp, const char *spec_orig,
 302     zfs_iter_f func, void *arg)
 303 {
 304         char buf[ZFS_MAXNAMELEN];
 305         char *comma_separated, *cp;
 306         int err = 0;
 307         int ret = 0;
 308 
 309         (void) strlcpy(buf, spec_orig, sizeof (buf));
 310         cp = buf;
 311 
 312         while ((comma_separated = strsep(&cp, ",")) != NULL) {
 313                 char *pct = strchr(comma_separated, '%');
 314                 if (pct != NULL) {
 315                         snapspec_arg_t ssa = { 0 };
 316                         ssa.ssa_func = func;
 317                         ssa.ssa_arg = arg;
 318 
 319                         if (pct == comma_separated)
 320                                 ssa.ssa_seenfirst = B_TRUE;
 321                         else
 322                                 ssa.ssa_first = comma_separated;
 323                         *pct = '\0';
 324                         ssa.ssa_last = pct + 1;
 325 
 326                         /*
 327                          * If there is a lastname specified, make sure it
 328                          * exists.
 329                          */
 330                         if (ssa.ssa_last[0] != '\0') {
 331                                 char snapname[ZFS_MAXNAMELEN];
 332                                 (void) snprintf(snapname, sizeof (snapname),
 333                                     "%s@%s", zfs_get_name(fs_zhp),
 334                                     ssa.ssa_last);
 335                                 if (!zfs_dataset_exists(fs_zhp->zfs_hdl,
 336                                     snapname, ZFS_TYPE_SNAPSHOT)) {
 337                                         ret = ENOENT;
 338                                         continue;
 339                                 }
 340                         }
 341 
 342                         err = zfs_iter_snapshots_sorted(fs_zhp,
 343                             snapspec_cb, &ssa);
 344                         if (ret == 0)
 345                                 ret = err;
 346                         if (ret == 0 && (!ssa.ssa_seenfirst ||
 347                             (ssa.ssa_last[0] != '\0' && !ssa.ssa_seenlast))) {
 348                                 ret = ENOENT;
 349                         }
 350                 } else {
 351                         char snapname[ZFS_MAXNAMELEN];
 352                         zfs_handle_t *snap_zhp;
 353                         (void) snprintf(snapname, sizeof (snapname), "%s@%s",
 354                             zfs_get_name(fs_zhp), comma_separated);
 355                         snap_zhp = make_dataset_handle(fs_zhp->zfs_hdl,
 356                             snapname);
 357                         if (snap_zhp == NULL) {
 358                                 ret = ENOENT;
 359                                 continue;
 360                         }
 361                         err = func(snap_zhp, arg);
 362                         if (ret == 0)
 363                                 ret = err;
 364                 }
 365         }
 366 
 367         return (ret);
 368 }
 369 
 370 /*
 371  * Iterate over all children, snapshots and filesystems
 372  */
 373 int
 374 zfs_iter_children(zfs_handle_t *zhp, zfs_iter_f func, void *data)
 375 {
 376         int ret;
 377 
 378         if ((ret = zfs_iter_filesystems(zhp, func, data)) != 0)
 379                 return (ret);
 380 
 381         return (zfs_iter_snapshots(zhp, func, data));
 382 }
 383 
 384 
 385 typedef struct iter_stack_frame {
 386         struct iter_stack_frame *next;
 387         zfs_handle_t *zhp;
 388 } iter_stack_frame_t;
 389 
 390 typedef struct iter_dependents_arg {
 391         boolean_t first;
 392         boolean_t allowrecursion;
 393         iter_stack_frame_t *stack;
 394         zfs_iter_f func;
 395         void *data;
 396 } iter_dependents_arg_t;
 397 
 398 static int
 399 iter_dependents_cb(zfs_handle_t *zhp, void *arg)
 400 {
 401         iter_dependents_arg_t *ida = arg;
 402         int err;
 403         boolean_t first = ida->first;
 404         ida->first = B_FALSE;
 405 
 406         if (zhp->zfs_type == ZFS_TYPE_SNAPSHOT) {
 407                 err = zfs_iter_clones(zhp, iter_dependents_cb, ida);
 408         } else {
 409                 iter_stack_frame_t isf;
 410                 iter_stack_frame_t *f;
 411 
 412                 /*
 413                  * check if there is a cycle by seeing if this fs is already
 414                  * on the stack.
 415                  */
 416                 for (f = ida->stack; f != NULL; f = f->next) {
 417                         if (f->zhp->zfs_dmustats.dds_guid ==
 418                             zhp->zfs_dmustats.dds_guid) {
 419                                 if (ida->allowrecursion) {
 420                                         zfs_close(zhp);
 421                                         return (0);
 422                                 } else {
 423                                         zfs_error_aux(zhp->zfs_hdl,
 424                                             dgettext(TEXT_DOMAIN,
 425                                             "recursive dependency at '%s'"),
 426                                             zfs_get_name(zhp));
 427                                         err = zfs_error(zhp->zfs_hdl,
 428                                             EZFS_RECURSIVE,
 429                                             dgettext(TEXT_DOMAIN,
 430                                             "cannot determine dependent "
 431                                             "datasets"));
 432                                         zfs_close(zhp);
 433                                         return (err);
 434                                 }
 435                         }
 436                 }
 437 
 438                 isf.zhp = zhp;
 439                 isf.next = ida->stack;
 440                 ida->stack = &isf;
 441                 err = zfs_iter_filesystems(zhp, iter_dependents_cb, ida);
 442                 if (err == 0)
 443                         err = zfs_iter_snapshots(zhp, iter_dependents_cb, ida);
 444                 ida->stack = isf.next;
 445         }
 446         if (!first && err == 0)
 447                 err = ida->func(zhp, ida->data);
 448         return (err);
 449 }
 450 
 451 int
 452 zfs_iter_dependents(zfs_handle_t *zhp, boolean_t allowrecursion,
 453     zfs_iter_f func, void *data)
 454 {
 455         iter_dependents_arg_t ida;
 456         ida.allowrecursion = allowrecursion;
 457         ida.stack = NULL;
 458         ida.func = func;
 459         ida.data = data;
 460         ida.first = B_TRUE;
 461         return (iter_dependents_cb(zfs_handle_dup(zhp), &ida));
 462 }