libzfs_iter.c revision 248571
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) 2012 by Delphix. All rights reserved. 26 * Copyright (c) 2012 Pawel Jakub Dawidek <pawel@dawidek.net>. 27 * All rights reserved. 28 */ 29 30#include <stdio.h> 31#include <stdlib.h> 32#include <strings.h> 33#include <unistd.h> 34#include <stddef.h> 35#include <libintl.h> 36#include <libzfs.h> 37 38#include "libzfs_impl.h" 39 40int 41zfs_iter_clones(zfs_handle_t *zhp, zfs_iter_f func, void *data) 42{ 43 nvlist_t *nvl = zfs_get_clones_nvl(zhp); 44 nvpair_t *pair; 45 46 if (nvl == NULL) 47 return (0); 48 49 for (pair = nvlist_next_nvpair(nvl, NULL); pair != NULL; 50 pair = nvlist_next_nvpair(nvl, pair)) { 51 zfs_handle_t *clone = zfs_open(zhp->zfs_hdl, nvpair_name(pair), 52 ZFS_TYPE_FILESYSTEM | ZFS_TYPE_VOLUME); 53 if (clone != NULL) { 54 int err = func(clone, data); 55 if (err != 0) 56 return (err); 57 } 58 } 59 return (0); 60} 61 62static int 63zfs_do_list_ioctl(zfs_handle_t *zhp, unsigned long arg, zfs_cmd_t *zc) 64{ 65 int rc; 66 uint64_t orig_cookie; 67 68 orig_cookie = zc->zc_cookie; 69top: 70 (void) strlcpy(zc->zc_name, zhp->zfs_name, sizeof (zc->zc_name)); 71 rc = ioctl(zhp->zfs_hdl->libzfs_fd, arg, zc); 72 73 if (rc == -1) { 74 switch (errno) { 75 case ENOMEM: 76 /* expand nvlist memory and try again */ 77 if (zcmd_expand_dst_nvlist(zhp->zfs_hdl, zc) != 0) { 78 zcmd_free_nvlists(zc); 79 return (-1); 80 } 81 zc->zc_cookie = orig_cookie; 82 goto top; 83 /* 84 * An errno value of ESRCH indicates normal completion. 85 * If ENOENT is returned, then the underlying dataset 86 * has been removed since we obtained the handle. 87 */ 88 case ESRCH: 89 case ENOENT: 90 rc = 1; 91 break; 92 default: 93 rc = zfs_standard_error(zhp->zfs_hdl, errno, 94 dgettext(TEXT_DOMAIN, 95 "cannot iterate filesystems")); 96 break; 97 } 98 } 99 return (rc); 100} 101 102/* 103 * Iterate over all child filesystems 104 */ 105int 106zfs_iter_filesystems(zfs_handle_t *zhp, zfs_iter_f func, void *data) 107{ 108 zfs_cmd_t zc = { 0 }; 109 zfs_handle_t *nzhp; 110 int ret; 111 112 if (zhp->zfs_type != ZFS_TYPE_FILESYSTEM) 113 return (0); 114 115 if (zcmd_alloc_dst_nvlist(zhp->zfs_hdl, &zc, 0) != 0) 116 return (-1); 117 118 while ((ret = zfs_do_list_ioctl(zhp, ZFS_IOC_DATASET_LIST_NEXT, 119 &zc)) == 0) { 120 /* 121 * Silently ignore errors, as the only plausible explanation is 122 * that the pool has since been removed. 123 */ 124 if ((nzhp = make_dataset_handle_zc(zhp->zfs_hdl, 125 &zc)) == NULL) { 126 continue; 127 } 128 129 if ((ret = func(nzhp, data)) != 0) { 130 zcmd_free_nvlists(&zc); 131 return (ret); 132 } 133 } 134 zcmd_free_nvlists(&zc); 135 return ((ret < 0) ? ret : 0); 136} 137 138/* 139 * Iterate over all snapshots 140 */ 141int 142zfs_iter_snapshots(zfs_handle_t *zhp, boolean_t simple, zfs_iter_f func, 143 void *data) 144{ 145 zfs_cmd_t zc = { 0 }; 146 zfs_handle_t *nzhp; 147 int ret; 148 149 if (zhp->zfs_type == ZFS_TYPE_SNAPSHOT) 150 return (0); 151 152 zc.zc_simple = simple; 153 154 if (zcmd_alloc_dst_nvlist(zhp->zfs_hdl, &zc, 0) != 0) 155 return (-1); 156 while ((ret = zfs_do_list_ioctl(zhp, ZFS_IOC_SNAPSHOT_LIST_NEXT, 157 &zc)) == 0) { 158 159 if (simple) 160 nzhp = make_dataset_simple_handle_zc(zhp, &zc); 161 else 162 nzhp = make_dataset_handle_zc(zhp->zfs_hdl, &zc); 163 if (nzhp == NULL) 164 continue; 165 166 if ((ret = func(nzhp, data)) != 0) { 167 zcmd_free_nvlists(&zc); 168 return (ret); 169 } 170 } 171 zcmd_free_nvlists(&zc); 172 return ((ret < 0) ? ret : 0); 173} 174 175/* 176 * Routines for dealing with the sorted snapshot functionality 177 */ 178typedef struct zfs_node { 179 zfs_handle_t *zn_handle; 180 avl_node_t zn_avlnode; 181} zfs_node_t; 182 183static int 184zfs_sort_snaps(zfs_handle_t *zhp, void *data) 185{ 186 avl_tree_t *avl = data; 187 zfs_node_t *node; 188 zfs_node_t search; 189 190 search.zn_handle = zhp; 191 node = avl_find(avl, &search, NULL); 192 if (node) { 193 /* 194 * If this snapshot was renamed while we were creating the 195 * AVL tree, it's possible that we already inserted it under 196 * its old name. Remove the old handle before adding the new 197 * one. 198 */ 199 zfs_close(node->zn_handle); 200 avl_remove(avl, node); 201 free(node); 202 } 203 204 node = zfs_alloc(zhp->zfs_hdl, sizeof (zfs_node_t)); 205 node->zn_handle = zhp; 206 avl_add(avl, node); 207 208 return (0); 209} 210 211static int 212zfs_snapshot_compare(const void *larg, const void *rarg) 213{ 214 zfs_handle_t *l = ((zfs_node_t *)larg)->zn_handle; 215 zfs_handle_t *r = ((zfs_node_t *)rarg)->zn_handle; 216 uint64_t lcreate, rcreate; 217 218 /* 219 * Sort them according to creation time. We use the hidden 220 * CREATETXG property to get an absolute ordering of snapshots. 221 */ 222 lcreate = zfs_prop_get_int(l, ZFS_PROP_CREATETXG); 223 rcreate = zfs_prop_get_int(r, ZFS_PROP_CREATETXG); 224 225 if (lcreate < rcreate) 226 return (-1); 227 else if (lcreate > rcreate) 228 return (+1); 229 else 230 return (0); 231} 232 233int 234zfs_iter_snapshots_sorted(zfs_handle_t *zhp, zfs_iter_f callback, void *data) 235{ 236 int ret = 0; 237 zfs_node_t *node; 238 avl_tree_t avl; 239 void *cookie = NULL; 240 241 avl_create(&avl, zfs_snapshot_compare, 242 sizeof (zfs_node_t), offsetof(zfs_node_t, zn_avlnode)); 243 244 ret = zfs_iter_snapshots(zhp, B_FALSE, zfs_sort_snaps, &avl); 245 246 for (node = avl_first(&avl); node != NULL; node = AVL_NEXT(&avl, node)) 247 ret |= callback(node->zn_handle, data); 248 249 while ((node = avl_destroy_nodes(&avl, &cookie)) != NULL) 250 free(node); 251 252 avl_destroy(&avl); 253 254 return (ret); 255} 256 257typedef struct { 258 char *ssa_first; 259 char *ssa_last; 260 boolean_t ssa_seenfirst; 261 boolean_t ssa_seenlast; 262 zfs_iter_f ssa_func; 263 void *ssa_arg; 264} snapspec_arg_t; 265 266static int 267snapspec_cb(zfs_handle_t *zhp, void *arg) { 268 snapspec_arg_t *ssa = arg; 269 char *shortsnapname; 270 int err = 0; 271 272 if (ssa->ssa_seenlast) 273 return (0); 274 shortsnapname = zfs_strdup(zhp->zfs_hdl, 275 strchr(zfs_get_name(zhp), '@') + 1); 276 277 if (!ssa->ssa_seenfirst && strcmp(shortsnapname, ssa->ssa_first) == 0) 278 ssa->ssa_seenfirst = B_TRUE; 279 280 if (ssa->ssa_seenfirst) { 281 err = ssa->ssa_func(zhp, ssa->ssa_arg); 282 } else { 283 zfs_close(zhp); 284 } 285 286 if (strcmp(shortsnapname, ssa->ssa_last) == 0) 287 ssa->ssa_seenlast = B_TRUE; 288 free(shortsnapname); 289 290 return (err); 291} 292 293/* 294 * spec is a string like "A,B%C,D" 295 * 296 * <snaps>, where <snaps> can be: 297 * <snap> (single snapshot) 298 * <snap>%<snap> (range of snapshots, inclusive) 299 * %<snap> (range of snapshots, starting with earliest) 300 * <snap>% (range of snapshots, ending with last) 301 * % (all snapshots) 302 * <snaps>[,...] (comma separated list of the above) 303 * 304 * If a snapshot can not be opened, continue trying to open the others, but 305 * return ENOENT at the end. 306 */ 307int 308zfs_iter_snapspec(zfs_handle_t *fs_zhp, const char *spec_orig, 309 zfs_iter_f func, void *arg) 310{ 311 char *buf, *comma_separated, *cp; 312 int err = 0; 313 int ret = 0; 314 315 buf = zfs_strdup(fs_zhp->zfs_hdl, spec_orig); 316 cp = buf; 317 318 while ((comma_separated = strsep(&cp, ",")) != NULL) { 319 char *pct = strchr(comma_separated, '%'); 320 if (pct != NULL) { 321 snapspec_arg_t ssa = { 0 }; 322 ssa.ssa_func = func; 323 ssa.ssa_arg = arg; 324 325 if (pct == comma_separated) 326 ssa.ssa_seenfirst = B_TRUE; 327 else 328 ssa.ssa_first = comma_separated; 329 *pct = '\0'; 330 ssa.ssa_last = pct + 1; 331 332 /* 333 * If there is a lastname specified, make sure it 334 * exists. 335 */ 336 if (ssa.ssa_last[0] != '\0') { 337 char snapname[ZFS_MAXNAMELEN]; 338 (void) snprintf(snapname, sizeof (snapname), 339 "%s@%s", zfs_get_name(fs_zhp), 340 ssa.ssa_last); 341 if (!zfs_dataset_exists(fs_zhp->zfs_hdl, 342 snapname, ZFS_TYPE_SNAPSHOT)) { 343 ret = ENOENT; 344 continue; 345 } 346 } 347 348 err = zfs_iter_snapshots_sorted(fs_zhp, 349 snapspec_cb, &ssa); 350 if (ret == 0) 351 ret = err; 352 if (ret == 0 && (!ssa.ssa_seenfirst || 353 (ssa.ssa_last[0] != '\0' && !ssa.ssa_seenlast))) { 354 ret = ENOENT; 355 } 356 } else { 357 char snapname[ZFS_MAXNAMELEN]; 358 zfs_handle_t *snap_zhp; 359 (void) snprintf(snapname, sizeof (snapname), "%s@%s", 360 zfs_get_name(fs_zhp), comma_separated); 361 snap_zhp = make_dataset_handle(fs_zhp->zfs_hdl, 362 snapname); 363 if (snap_zhp == NULL) { 364 ret = ENOENT; 365 continue; 366 } 367 err = func(snap_zhp, arg); 368 if (ret == 0) 369 ret = err; 370 } 371 } 372 373 free(buf); 374 return (ret); 375} 376 377/* 378 * Iterate over all children, snapshots and filesystems 379 */ 380int 381zfs_iter_children(zfs_handle_t *zhp, zfs_iter_f func, void *data) 382{ 383 int ret; 384 385 if ((ret = zfs_iter_filesystems(zhp, func, data)) != 0) 386 return (ret); 387 388 return (zfs_iter_snapshots(zhp, B_FALSE, func, data)); 389} 390 391 392typedef struct iter_stack_frame { 393 struct iter_stack_frame *next; 394 zfs_handle_t *zhp; 395} iter_stack_frame_t; 396 397typedef struct iter_dependents_arg { 398 boolean_t first; 399 boolean_t allowrecursion; 400 iter_stack_frame_t *stack; 401 zfs_iter_f func; 402 void *data; 403} iter_dependents_arg_t; 404 405static int 406iter_dependents_cb(zfs_handle_t *zhp, void *arg) 407{ 408 iter_dependents_arg_t *ida = arg; 409 int err; 410 boolean_t first = ida->first; 411 ida->first = B_FALSE; 412 413 if (zhp->zfs_type == ZFS_TYPE_SNAPSHOT) { 414 err = zfs_iter_clones(zhp, iter_dependents_cb, ida); 415 } else { 416 iter_stack_frame_t isf; 417 iter_stack_frame_t *f; 418 419 /* 420 * check if there is a cycle by seeing if this fs is already 421 * on the stack. 422 */ 423 for (f = ida->stack; f != NULL; f = f->next) { 424 if (f->zhp->zfs_dmustats.dds_guid == 425 zhp->zfs_dmustats.dds_guid) { 426 if (ida->allowrecursion) { 427 zfs_close(zhp); 428 return (0); 429 } else { 430 zfs_error_aux(zhp->zfs_hdl, 431 dgettext(TEXT_DOMAIN, 432 "recursive dependency at '%s'"), 433 zfs_get_name(zhp)); 434 err = zfs_error(zhp->zfs_hdl, 435 EZFS_RECURSIVE, 436 dgettext(TEXT_DOMAIN, 437 "cannot determine dependent " 438 "datasets")); 439 zfs_close(zhp); 440 return (err); 441 } 442 } 443 } 444 445 isf.zhp = zhp; 446 isf.next = ida->stack; 447 ida->stack = &isf; 448 err = zfs_iter_filesystems(zhp, iter_dependents_cb, ida); 449 if (err == 0) { 450 err = zfs_iter_snapshots(zhp, B_FALSE, 451 iter_dependents_cb, ida); 452 } 453 ida->stack = isf.next; 454 } 455 if (!first && err == 0) 456 err = ida->func(zhp, ida->data); 457 return (err); 458} 459 460int 461zfs_iter_dependents(zfs_handle_t *zhp, boolean_t allowrecursion, 462 zfs_iter_f func, void *data) 463{ 464 iter_dependents_arg_t ida; 465 ida.allowrecursion = allowrecursion; 466 ida.stack = NULL; 467 ida.func = func; 468 ida.data = data; 469 ida.first = B_TRUE; 470 return (iter_dependents_cb(zfs_handle_dup(zhp), &ida)); 471} 472