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) 2010, Oracle and/or its affiliates. All rights reserved. 24 * Copyright 2015 Nexenta Systems, Inc. All rights reserved. 25 * Copyright (c) 2015 by Delphix. All rights reserved. 26 * Copyright 2016 Joyent, Inc. 27 * Copyright 2016 Igor Kozhukhov <ikozhukhov@gmail.com> 28 */ 29 30 /* 31 * zfs diff support 32 */ 33 #include <ctype.h> 34 #include <errno.h> 35 #include <libintl.h> 36 #include <string.h> 37 #include <sys/types.h> 38 #include <sys/stat.h> 39 #include <fcntl.h> 40 #include <attr.h> 41 #include <stddef.h> 42 #include <unistd.h> 43 #include <stdio.h> 44 #include <stdlib.h> 45 #include <stropts.h> 46 #include <pthread.h> 47 #include <sys/zfs_ioctl.h> 48 #include <libzfs.h> 49 #include "libzfs_impl.h" 50 51 #define ZDIFF_SNAPDIR "/.zfs/snapshot/" 52 #define ZDIFF_SHARESDIR "/.zfs/shares/" 53 #define ZDIFF_PREFIX "zfs-diff-%d" 54 55 #define ZDIFF_ADDED '+' 56 #define ZDIFF_MODIFIED 'M' 57 #define ZDIFF_REMOVED '-' 58 #define ZDIFF_RENAMED 'R' 59 60 typedef struct differ_info { 61 zfs_handle_t *zhp; 62 char *fromsnap; 63 char *frommnt; 64 char *tosnap; 65 char *tomnt; 66 char *ds; 67 char *dsmnt; 68 char *tmpsnap; 69 char errbuf[1024]; 70 boolean_t isclone; 71 boolean_t scripted; 72 boolean_t classify; 73 boolean_t timestamped; 74 uint64_t shares; 75 int zerr; 76 int cleanupfd; 77 int outputfd; 78 int datafd; 79 } differ_info_t; 80 81 /* 82 * Given a {dsname, object id}, get the object path 83 */ 84 static int 85 get_stats_for_obj(differ_info_t *di, const char *dsname, uint64_t obj, 86 char *pn, int maxlen, zfs_stat_t *sb) 87 { 88 zfs_cmd_t zc = { 0 }; 89 int error; 90 91 (void) strlcpy(zc.zc_name, dsname, sizeof (zc.zc_name)); 92 zc.zc_obj = obj; 93 94 errno = 0; 95 error = ioctl(di->zhp->zfs_hdl->libzfs_fd, ZFS_IOC_OBJ_TO_STATS, &zc); 96 di->zerr = errno; 97 98 /* we can get stats even if we failed to get a path */ 99 (void) memcpy(sb, &zc.zc_stat, sizeof (zfs_stat_t)); 100 if (error == 0) { 101 ASSERT(di->zerr == 0); 102 (void) strlcpy(pn, zc.zc_value, maxlen); 103 return (0); 104 } 105 106 if (di->zerr == EPERM) { 107 (void) snprintf(di->errbuf, sizeof (di->errbuf), 108 dgettext(TEXT_DOMAIN, 109 "The sys_config privilege or diff delegated permission " 110 "is needed\nto discover path names")); 111 return (-1); 112 } else { 113 (void) snprintf(di->errbuf, sizeof (di->errbuf), 114 dgettext(TEXT_DOMAIN, 115 "Unable to determine path or stats for " 116 "object %lld in %s"), obj, dsname); 117 return (-1); 118 } 119 } 120 121 /* 122 * stream_bytes 123 * 124 * Prints a file name out a character at a time. If the character is 125 * not in the range of what we consider "printable" ASCII, display it 126 * as an escaped 3-digit octal value. ASCII values less than a space 127 * are all control characters and we declare the upper end as the 128 * DELete character. This also is the last 7-bit ASCII character. 129 * We choose to treat all 8-bit ASCII as not printable for this 130 * application. 131 */ 132 static void 133 stream_bytes(FILE *fp, const char *string) 134 { 135 char c; 136 137 while ((c = *string++) != '\0') { 138 if (c > ' ' && c != '\\' && c < '\177') { 139 (void) fprintf(fp, "%c", c); 140 } else { 141 (void) fprintf(fp, "\\%03o", (uint8_t)c); 142 } 143 } 144 } 145 146 static void 147 print_what(FILE *fp, mode_t what) 148 { 149 char symbol; 150 151 switch (what & S_IFMT) { 152 case S_IFBLK: 153 symbol = 'B'; 154 break; 155 case S_IFCHR: 156 symbol = 'C'; 157 break; 158 case S_IFDIR: 159 symbol = '/'; 160 break; 161 case S_IFDOOR: 162 symbol = '>'; 163 break; 164 case S_IFIFO: 165 symbol = '|'; 166 break; 167 case S_IFLNK: 168 symbol = '@'; 169 break; 170 case S_IFPORT: 171 symbol = 'P'; 172 break; 173 case S_IFSOCK: 174 symbol = '='; 175 break; 176 case S_IFREG: 177 symbol = 'F'; 178 break; 179 default: 180 symbol = '?'; 181 break; 182 } 183 (void) fprintf(fp, "%c", symbol); 184 } 185 186 static void 187 print_cmn(FILE *fp, differ_info_t *di, const char *file) 188 { 189 stream_bytes(fp, di->dsmnt); 190 stream_bytes(fp, file); 191 } 192 193 static void 194 print_rename(FILE *fp, differ_info_t *di, const char *old, const char *new, 195 zfs_stat_t *isb) 196 { 197 if (di->timestamped) 198 (void) fprintf(fp, "%10lld.%09lld\t", 199 (longlong_t)isb->zs_ctime[0], 200 (longlong_t)isb->zs_ctime[1]); 201 (void) fprintf(fp, "%c\t", ZDIFF_RENAMED); 202 if (di->classify) { 203 print_what(fp, isb->zs_mode); 204 (void) fprintf(fp, "\t"); 205 } 206 print_cmn(fp, di, old); 207 if (di->scripted) 208 (void) fprintf(fp, "\t"); 209 else 210 (void) fprintf(fp, " -> "); 211 print_cmn(fp, di, new); 212 (void) fprintf(fp, "\n"); 213 } 214 215 static void 216 print_link_change(FILE *fp, differ_info_t *di, int delta, const char *file, 217 zfs_stat_t *isb) 218 { 219 if (di->timestamped) 220 (void) fprintf(fp, "%10lld.%09lld\t", 221 (longlong_t)isb->zs_ctime[0], 222 (longlong_t)isb->zs_ctime[1]); 223 (void) fprintf(fp, "%c\t", ZDIFF_MODIFIED); 224 if (di->classify) { 225 print_what(fp, isb->zs_mode); 226 (void) fprintf(fp, "\t"); 227 } 228 print_cmn(fp, di, file); 229 (void) fprintf(fp, "\t(%+d)", delta); 230 (void) fprintf(fp, "\n"); 231 } 232 233 static void 234 print_file(FILE *fp, differ_info_t *di, char type, const char *file, 235 zfs_stat_t *isb) 236 { 237 if (di->timestamped) 238 (void) fprintf(fp, "%10lld.%09lld\t", 239 (longlong_t)isb->zs_ctime[0], 240 (longlong_t)isb->zs_ctime[1]); 241 (void) fprintf(fp, "%c\t", type); 242 if (di->classify) { 243 print_what(fp, isb->zs_mode); 244 (void) fprintf(fp, "\t"); 245 } 246 print_cmn(fp, di, file); 247 (void) fprintf(fp, "\n"); 248 } 249 250 static int 251 write_inuse_diffs_one(FILE *fp, differ_info_t *di, uint64_t dobj) 252 { 253 struct zfs_stat fsb, tsb; 254 mode_t fmode, tmode; 255 char fobjname[MAXPATHLEN], tobjname[MAXPATHLEN]; 256 int fobjerr, tobjerr; 257 int change; 258 259 if (dobj == di->shares) 260 return (0); 261 262 /* 263 * Check the from and to snapshots for info on the object. If 264 * we get ENOENT, then the object just didn't exist in that 265 * snapshot. If we get ENOTSUP, then we tried to get 266 * info on a non-ZPL object, which we don't care about anyway. 267 */ 268 fobjerr = get_stats_for_obj(di, di->fromsnap, dobj, fobjname, 269 MAXPATHLEN, &fsb); 270 if (fobjerr && di->zerr != ENOENT && di->zerr != ENOTSUP) 271 return (-1); 272 273 tobjerr = get_stats_for_obj(di, di->tosnap, dobj, tobjname, 274 MAXPATHLEN, &tsb); 275 if (tobjerr && di->zerr != ENOENT && di->zerr != ENOTSUP) 276 return (-1); 277 278 /* 279 * Unallocated object sharing the same meta dnode block 280 */ 281 if (fobjerr && tobjerr) { 282 ASSERT(di->zerr == ENOENT || di->zerr == ENOTSUP); 283 di->zerr = 0; 284 return (0); 285 } 286 287 di->zerr = 0; /* negate get_stats_for_obj() from side that failed */ 288 fmode = fsb.zs_mode & S_IFMT; 289 tmode = tsb.zs_mode & S_IFMT; 290 if (fmode == S_IFDIR || tmode == S_IFDIR || fsb.zs_links == 0 || 291 tsb.zs_links == 0) 292 change = 0; 293 else 294 change = tsb.zs_links - fsb.zs_links; 295 296 if (fobjerr) { 297 if (change) { 298 print_link_change(fp, di, change, tobjname, &tsb); 299 return (0); 300 } 301 print_file(fp, di, ZDIFF_ADDED, tobjname, &tsb); 302 return (0); 303 } else if (tobjerr) { 304 if (change) { 305 print_link_change(fp, di, change, fobjname, &fsb); 306 return (0); 307 } 308 print_file(fp, di, ZDIFF_REMOVED, fobjname, &fsb); 309 return (0); 310 } 311 312 if (fmode != tmode && fsb.zs_gen == tsb.zs_gen) 313 tsb.zs_gen++; /* Force a generational difference */ 314 315 /* Simple modification or no change */ 316 if (fsb.zs_gen == tsb.zs_gen) { 317 /* No apparent changes. Could we assert !this? */ 318 if (fsb.zs_ctime[0] == tsb.zs_ctime[0] && 319 fsb.zs_ctime[1] == tsb.zs_ctime[1]) 320 return (0); 321 if (change) { 322 print_link_change(fp, di, change, 323 change > 0 ? fobjname : tobjname, &tsb); 324 } else if (strcmp(fobjname, tobjname) == 0) { 325 print_file(fp, di, ZDIFF_MODIFIED, fobjname, &tsb); 326 } else { 327 print_rename(fp, di, fobjname, tobjname, &tsb); 328 } 329 return (0); 330 } else { 331 /* file re-created or object re-used */ 332 print_file(fp, di, ZDIFF_REMOVED, fobjname, &fsb); 333 print_file(fp, di, ZDIFF_ADDED, tobjname, &tsb); 334 return (0); 335 } 336 } 337 338 static int 339 write_inuse_diffs(FILE *fp, differ_info_t *di, dmu_diff_record_t *dr) 340 { 341 uint64_t o; 342 int err; 343 344 for (o = dr->ddr_first; o <= dr->ddr_last; o++) { 345 if ((err = write_inuse_diffs_one(fp, di, o)) != 0) 346 return (err); 347 } 348 return (0); 349 } 350 351 static int 352 describe_free(FILE *fp, differ_info_t *di, uint64_t object, char *namebuf, 353 int maxlen) 354 { 355 struct zfs_stat sb; 356 357 if (get_stats_for_obj(di, di->fromsnap, object, namebuf, 358 maxlen, &sb) != 0) { 359 /* Let it slide, if in the delete queue on from side */ 360 if (di->zerr == ENOENT && sb.zs_links == 0) { 361 di->zerr = 0; 362 return (0); 363 } 364 return (-1); 365 } 366 367 print_file(fp, di, ZDIFF_REMOVED, namebuf, &sb); 368 return (0); 369 } 370 371 static int 372 write_free_diffs(FILE *fp, differ_info_t *di, dmu_diff_record_t *dr) 373 { 374 zfs_cmd_t zc = { 0 }; 375 libzfs_handle_t *lhdl = di->zhp->zfs_hdl; 376 char fobjname[MAXPATHLEN]; 377 378 (void) strlcpy(zc.zc_name, di->fromsnap, sizeof (zc.zc_name)); 379 zc.zc_obj = dr->ddr_first - 1; 380 381 ASSERT(di->zerr == 0); 382 383 while (zc.zc_obj < dr->ddr_last) { 384 int err; 385 386 err = ioctl(lhdl->libzfs_fd, ZFS_IOC_NEXT_OBJ, &zc); 387 if (err == 0) { 388 if (zc.zc_obj == di->shares) { 389 zc.zc_obj++; 390 continue; 391 } 392 if (zc.zc_obj > dr->ddr_last) { 393 break; 394 } 395 err = describe_free(fp, di, zc.zc_obj, fobjname, 396 MAXPATHLEN); 397 if (err) 398 break; 399 } else if (errno == ESRCH) { 400 break; 401 } else { 402 (void) snprintf(di->errbuf, sizeof (di->errbuf), 403 dgettext(TEXT_DOMAIN, 404 "next allocated object (> %lld) find failure"), 405 zc.zc_obj); 406 di->zerr = errno; 407 break; 408 } 409 } 410 if (di->zerr) 411 return (-1); 412 return (0); 413 } 414 415 static void * 416 differ(void *arg) 417 { 418 differ_info_t *di = arg; 419 dmu_diff_record_t dr; 420 FILE *ofp; 421 int err = 0; 422 423 if ((ofp = fdopen(di->outputfd, "w")) == NULL) { 424 di->zerr = errno; 425 (void) strerror_r(errno, di->errbuf, sizeof (di->errbuf)); 426 (void) close(di->datafd); 427 return ((void *)-1); 428 } 429 430 for (;;) { 431 char *cp = (char *)&dr; 432 int len = sizeof (dr); 433 int rv; 434 435 do { 436 rv = read(di->datafd, cp, len); 437 cp += rv; 438 len -= rv; 439 } while (len > 0 && rv > 0); 440 441 if (rv < 0 || (rv == 0 && len != sizeof (dr))) { 442 di->zerr = EPIPE; 443 break; 444 } else if (rv == 0) { 445 /* end of file at a natural breaking point */ 446 break; 447 } 448 449 switch (dr.ddr_type) { 450 case DDR_FREE: 451 err = write_free_diffs(ofp, di, &dr); 452 break; 453 case DDR_INUSE: 454 err = write_inuse_diffs(ofp, di, &dr); 455 break; 456 default: 457 di->zerr = EPIPE; 458 break; 459 } 460 461 if (err || di->zerr) 462 break; 463 } 464 465 (void) fclose(ofp); 466 (void) close(di->datafd); 467 if (err) 468 return ((void *)-1); 469 if (di->zerr) { 470 ASSERT(di->zerr == EINVAL); 471 (void) snprintf(di->errbuf, sizeof (di->errbuf), 472 dgettext(TEXT_DOMAIN, 473 "Internal error: bad data from diff IOCTL")); 474 return ((void *)-1); 475 } 476 return ((void *)0); 477 } 478 479 static int 480 find_shares_object(differ_info_t *di) 481 { 482 char fullpath[MAXPATHLEN]; 483 struct stat64 sb = { 0 }; 484 485 (void) strlcpy(fullpath, di->dsmnt, MAXPATHLEN); 486 (void) strlcat(fullpath, ZDIFF_SHARESDIR, MAXPATHLEN); 487 488 if (stat64(fullpath, &sb) != 0) { 489 (void) snprintf(di->errbuf, sizeof (di->errbuf), 490 dgettext(TEXT_DOMAIN, "Cannot stat %s"), fullpath); 491 return (zfs_error(di->zhp->zfs_hdl, EZFS_DIFF, di->errbuf)); 492 } 493 494 di->shares = (uint64_t)sb.st_ino; 495 return (0); 496 } 497 498 static int 499 make_temp_snapshot(differ_info_t *di) 500 { 501 libzfs_handle_t *hdl = di->zhp->zfs_hdl; 502 zfs_cmd_t zc = { 0 }; 503 504 (void) snprintf(zc.zc_value, sizeof (zc.zc_value), 505 ZDIFF_PREFIX, getpid()); 506 (void) strlcpy(zc.zc_name, di->ds, sizeof (zc.zc_name)); 507 zc.zc_cleanup_fd = di->cleanupfd; 508 509 if (ioctl(hdl->libzfs_fd, ZFS_IOC_TMP_SNAPSHOT, &zc) != 0) { 510 int err = errno; 511 if (err == EPERM) { 512 (void) snprintf(di->errbuf, sizeof (di->errbuf), 513 dgettext(TEXT_DOMAIN, "The diff delegated " 514 "permission is needed in order\nto create a " 515 "just-in-time snapshot for diffing\n")); 516 return (zfs_error(hdl, EZFS_DIFF, di->errbuf)); 517 } else { 518 (void) snprintf(di->errbuf, sizeof (di->errbuf), 519 dgettext(TEXT_DOMAIN, "Cannot create just-in-time " 520 "snapshot of '%s'"), zc.zc_name); 521 return (zfs_standard_error(hdl, err, di->errbuf)); 522 } 523 } 524 525 di->tmpsnap = zfs_strdup(hdl, zc.zc_value); 526 di->tosnap = zfs_asprintf(hdl, "%s@%s", di->ds, di->tmpsnap); 527 return (0); 528 } 529 530 static void 531 teardown_differ_info(differ_info_t *di) 532 { 533 free(di->ds); 534 free(di->dsmnt); 535 free(di->fromsnap); 536 free(di->frommnt); 537 free(di->tosnap); 538 free(di->tmpsnap); 539 free(di->tomnt); 540 (void) close(di->cleanupfd); 541 } 542 543 static int 544 get_snapshot_names(differ_info_t *di, const char *fromsnap, 545 const char *tosnap) 546 { 547 libzfs_handle_t *hdl = di->zhp->zfs_hdl; 548 char *atptrf = NULL; 549 char *atptrt = NULL; 550 int fdslen, fsnlen; 551 int tdslen, tsnlen; 552 553 /* 554 * Can accept 555 * dataset@snap1 556 * dataset@snap1 dataset@snap2 557 * dataset@snap1 @snap2 558 * dataset@snap1 dataset 559 * @snap1 dataset@snap2 560 */ 561 if (tosnap == NULL) { 562 /* only a from snapshot given, must be valid */ 563 (void) snprintf(di->errbuf, sizeof (di->errbuf), 564 dgettext(TEXT_DOMAIN, 565 "Badly formed snapshot name %s"), fromsnap); 566 567 if (!zfs_validate_name(hdl, fromsnap, ZFS_TYPE_SNAPSHOT, 568 B_FALSE)) { 569 return (zfs_error(hdl, EZFS_INVALIDNAME, 570 di->errbuf)); 571 } 572 573 atptrf = strchr(fromsnap, '@'); 574 ASSERT(atptrf != NULL); 575 fdslen = atptrf - fromsnap; 576 577 di->fromsnap = zfs_strdup(hdl, fromsnap); 578 di->ds = zfs_strdup(hdl, fromsnap); 579 di->ds[fdslen] = '\0'; 580 581 /* the to snap will be a just-in-time snap of the head */ 582 return (make_temp_snapshot(di)); 583 } 584 585 (void) snprintf(di->errbuf, sizeof (di->errbuf), 586 dgettext(TEXT_DOMAIN, 587 "Unable to determine which snapshots to compare")); 588 589 atptrf = strchr(fromsnap, '@'); 590 atptrt = strchr(tosnap, '@'); 591 fdslen = atptrf ? atptrf - fromsnap : strlen(fromsnap); 592 tdslen = atptrt ? atptrt - tosnap : strlen(tosnap); 593 fsnlen = strlen(fromsnap) - fdslen; /* includes @ sign */ 594 tsnlen = strlen(tosnap) - tdslen; /* includes @ sign */ 595 596 if (fsnlen <= 1 || tsnlen == 1 || (fdslen == 0 && tdslen == 0) || 597 (fsnlen == 0 && tsnlen == 0)) { 598 return (zfs_error(hdl, EZFS_INVALIDNAME, di->errbuf)); 599 } else if ((fdslen > 0 && tdslen > 0) && 600 ((tdslen != fdslen || strncmp(fromsnap, tosnap, fdslen) != 0))) { 601 /* 602 * not the same dataset name, might be okay if 603 * tosnap is a clone of a fromsnap descendant. 604 */ 605 char origin[ZFS_MAX_DATASET_NAME_LEN]; 606 zprop_source_t src; 607 zfs_handle_t *zhp; 608 609 di->ds = zfs_alloc(di->zhp->zfs_hdl, tdslen + 1); 610 (void) strncpy(di->ds, tosnap, tdslen); 611 di->ds[tdslen] = '\0'; 612 613 zhp = zfs_open(hdl, di->ds, ZFS_TYPE_FILESYSTEM); 614 while (zhp != NULL) { 615 if (zfs_prop_get(zhp, ZFS_PROP_ORIGIN, origin, 616 sizeof (origin), &src, NULL, 0, B_FALSE) != 0) { 617 (void) zfs_close(zhp); 618 zhp = NULL; 619 break; 620 } 621 if (strncmp(origin, fromsnap, fsnlen) == 0) 622 break; 623 624 (void) zfs_close(zhp); 625 zhp = zfs_open(hdl, origin, ZFS_TYPE_FILESYSTEM); 626 } 627 628 if (zhp == NULL) { 629 (void) snprintf(di->errbuf, sizeof (di->errbuf), 630 dgettext(TEXT_DOMAIN, 631 "Not an earlier snapshot from the same fs")); 632 return (zfs_error(hdl, EZFS_INVALIDNAME, di->errbuf)); 633 } else { 634 (void) zfs_close(zhp); 635 } 636 637 di->isclone = B_TRUE; 638 di->fromsnap = zfs_strdup(hdl, fromsnap); 639 if (tsnlen) { 640 di->tosnap = zfs_strdup(hdl, tosnap); 641 } else { 642 return (make_temp_snapshot(di)); 643 } 644 } else { 645 int dslen = fdslen ? fdslen : tdslen; 646 647 di->ds = zfs_alloc(hdl, dslen + 1); 648 (void) strncpy(di->ds, fdslen ? fromsnap : tosnap, dslen); 649 di->ds[dslen] = '\0'; 650 651 di->fromsnap = zfs_asprintf(hdl, "%s%s", di->ds, atptrf); 652 if (tsnlen) { 653 di->tosnap = zfs_asprintf(hdl, "%s%s", di->ds, atptrt); 654 } else { 655 return (make_temp_snapshot(di)); 656 } 657 } 658 return (0); 659 } 660 661 static int 662 get_mountpoint(differ_info_t *di, char *dsnm, char **mntpt) 663 { 664 boolean_t mounted; 665 666 mounted = is_mounted(di->zhp->zfs_hdl, dsnm, mntpt); 667 if (mounted == B_FALSE) { 668 (void) snprintf(di->errbuf, sizeof (di->errbuf), 669 dgettext(TEXT_DOMAIN, 670 "Cannot diff an unmounted snapshot")); 671 return (zfs_error(di->zhp->zfs_hdl, EZFS_BADTYPE, di->errbuf)); 672 } 673 674 /* Avoid a double slash at the beginning of root-mounted datasets */ 675 if (**mntpt == '/' && *(*mntpt + 1) == '\0') 676 **mntpt = '\0'; 677 return (0); 678 } 679 680 static int 681 get_mountpoints(differ_info_t *di) 682 { 683 char *strptr; 684 char *frommntpt; 685 686 /* 687 * first get the mountpoint for the parent dataset 688 */ 689 if (get_mountpoint(di, di->ds, &di->dsmnt) != 0) 690 return (-1); 691 692 strptr = strchr(di->tosnap, '@'); 693 ASSERT3P(strptr, !=, NULL); 694 di->tomnt = zfs_asprintf(di->zhp->zfs_hdl, "%s%s%s", di->dsmnt, 695 ZDIFF_SNAPDIR, ++strptr); 696 697 strptr = strchr(di->fromsnap, '@'); 698 ASSERT3P(strptr, !=, NULL); 699 700 frommntpt = di->dsmnt; 701 if (di->isclone) { 702 char *mntpt; 703 int err; 704 705 *strptr = '\0'; 706 err = get_mountpoint(di, di->fromsnap, &mntpt); 707 *strptr = '@'; 708 if (err != 0) 709 return (-1); 710 frommntpt = mntpt; 711 } 712 713 di->frommnt = zfs_asprintf(di->zhp->zfs_hdl, "%s%s%s", frommntpt, 714 ZDIFF_SNAPDIR, ++strptr); 715 716 if (di->isclone) 717 free(frommntpt); 718 719 return (0); 720 } 721 722 static int 723 setup_differ_info(zfs_handle_t *zhp, const char *fromsnap, 724 const char *tosnap, differ_info_t *di) 725 { 726 di->zhp = zhp; 727 728 di->cleanupfd = open(ZFS_DEV, O_RDWR|O_EXCL); 729 VERIFY(di->cleanupfd >= 0); 730 731 if (get_snapshot_names(di, fromsnap, tosnap) != 0) 732 return (-1); 733 734 if (get_mountpoints(di) != 0) 735 return (-1); 736 737 if (find_shares_object(di) != 0) 738 return (-1); 739 740 return (0); 741 } 742 743 int 744 zfs_show_diffs(zfs_handle_t *zhp, int outfd, const char *fromsnap, 745 const char *tosnap, int flags) 746 { 747 zfs_cmd_t zc = { 0 }; 748 char errbuf[1024]; 749 differ_info_t di = { 0 }; 750 pthread_t tid; 751 int pipefd[2]; 752 int iocerr; 753 754 (void) snprintf(errbuf, sizeof (errbuf), 755 dgettext(TEXT_DOMAIN, "zfs diff failed")); 756 757 if (setup_differ_info(zhp, fromsnap, tosnap, &di)) { 758 teardown_differ_info(&di); 759 return (-1); 760 } 761 762 if (pipe(pipefd)) { 763 zfs_error_aux(zhp->zfs_hdl, strerror(errno)); 764 teardown_differ_info(&di); 765 return (zfs_error(zhp->zfs_hdl, EZFS_PIPEFAILED, errbuf)); 766 } 767 768 di.scripted = (flags & ZFS_DIFF_PARSEABLE); 769 di.classify = (flags & ZFS_DIFF_CLASSIFY); 770 di.timestamped = (flags & ZFS_DIFF_TIMESTAMP); 771 772 di.outputfd = outfd; 773 di.datafd = pipefd[0]; 774 775 if (pthread_create(&tid, NULL, differ, &di)) { 776 zfs_error_aux(zhp->zfs_hdl, strerror(errno)); 777 (void) close(pipefd[0]); 778 (void) close(pipefd[1]); 779 teardown_differ_info(&di); 780 return (zfs_error(zhp->zfs_hdl, 781 EZFS_THREADCREATEFAILED, errbuf)); 782 } 783 784 /* do the ioctl() */ 785 (void) strlcpy(zc.zc_value, di.fromsnap, strlen(di.fromsnap) + 1); 786 (void) strlcpy(zc.zc_name, di.tosnap, strlen(di.tosnap) + 1); 787 zc.zc_cookie = pipefd[1]; 788 789 iocerr = ioctl(zhp->zfs_hdl->libzfs_fd, ZFS_IOC_DIFF, &zc); 790 if (iocerr != 0) { 791 (void) snprintf(errbuf, sizeof (errbuf), 792 dgettext(TEXT_DOMAIN, "Unable to obtain diffs")); 793 if (errno == EPERM) { 794 zfs_error_aux(zhp->zfs_hdl, dgettext(TEXT_DOMAIN, 795 "\n The sys_mount privilege or diff delegated " 796 "permission is needed\n to execute the " 797 "diff ioctl")); 798 } else if (errno == EXDEV) { 799 zfs_error_aux(zhp->zfs_hdl, dgettext(TEXT_DOMAIN, 800 "\n Not an earlier snapshot from the same fs")); 801 } else if (errno != EPIPE || di.zerr == 0) { 802 zfs_error_aux(zhp->zfs_hdl, strerror(errno)); 803 } 804 (void) close(pipefd[1]); 805 (void) pthread_cancel(tid); 806 (void) pthread_join(tid, NULL); 807 teardown_differ_info(&di); 808 if (di.zerr != 0 && di.zerr != EPIPE) { 809 zfs_error_aux(zhp->zfs_hdl, strerror(di.zerr)); 810 return (zfs_error(zhp->zfs_hdl, EZFS_DIFF, di.errbuf)); 811 } else { 812 return (zfs_error(zhp->zfs_hdl, EZFS_DIFFDATA, errbuf)); 813 } 814 } 815 816 (void) close(pipefd[1]); 817 (void) pthread_join(tid, NULL); 818 819 if (di.zerr != 0) { 820 zfs_error_aux(zhp->zfs_hdl, strerror(di.zerr)); 821 return (zfs_error(zhp->zfs_hdl, EZFS_DIFF, di.errbuf)); 822 } 823 teardown_differ_info(&di); 824 return (0); 825 } 826