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, 2018 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 <stddef.h> 41 #include <unistd.h> 42 #include <stdio.h> 43 #include <stdlib.h> 44 #include <stropts.h> 45 #include <pthread.h> 46 #include <sys/zfs_ioctl.h> 47 #include <libzfs.h> 48 #include "libzfs_impl.h" 49 50 #define ZDIFF_SNAPDIR "/.zfs/snapshot/" 51 #define ZDIFF_PREFIX "zfs-diff-%d" 52 53 #define ZDIFF_ADDED '+' 54 #define ZDIFF_MODIFIED 'M' 55 #define ZDIFF_REMOVED '-' 56 #define ZDIFF_RENAMED 'R' 57 58 59 /* 60 * Given a {dsname, object id}, get the object path 61 */ 62 static int 63 get_stats_for_obj(differ_info_t *di, const char *dsname, uint64_t obj, 64 char *pn, int maxlen, zfs_stat_t *sb) 65 { 66 zfs_cmd_t zc = {"\0"}; 67 int error; 68 69 (void) strlcpy(zc.zc_name, dsname, sizeof (zc.zc_name)); 70 zc.zc_obj = obj; 71 72 errno = 0; 73 error = zfs_ioctl(di->zhp->zfs_hdl, ZFS_IOC_OBJ_TO_STATS, &zc); 74 di->zerr = errno; 75 76 /* we can get stats even if we failed to get a path */ 77 (void) memcpy(sb, &zc.zc_stat, sizeof (zfs_stat_t)); 78 if (error == 0) { 79 ASSERT(di->zerr == 0); 80 (void) strlcpy(pn, zc.zc_value, maxlen); 81 return (0); 82 } 83 84 if (di->zerr == ESTALE) { 85 (void) snprintf(pn, maxlen, "(on_delete_queue)"); 86 return (0); 87 } else if (di->zerr == EPERM) { 88 (void) snprintf(di->errbuf, sizeof (di->errbuf), 89 dgettext(TEXT_DOMAIN, 90 "The sys_config privilege or diff delegated permission " 91 "is needed\nto discover path names")); 92 return (-1); 93 } else if (di->zerr == EACCES) { 94 (void) snprintf(di->errbuf, sizeof (di->errbuf), 95 dgettext(TEXT_DOMAIN, 96 "Key must be loaded to discover path names")); 97 return (-1); 98 } else { 99 (void) snprintf(di->errbuf, sizeof (di->errbuf), 100 dgettext(TEXT_DOMAIN, 101 "Unable to determine path or stats for " 102 "object %lld in %s"), (longlong_t)obj, dsname); 103 return (-1); 104 } 105 } 106 107 /* 108 * stream_bytes 109 * 110 * Prints a file name out a character at a time. If the character is 111 * not in the range of what we consider "printable" ASCII, display it 112 * as an escaped 4-digit octal value. ASCII values less than a space 113 * are all control characters and we declare the upper end as the 114 * DELete character. This also is the last 7-bit ASCII character. 115 * We choose to treat all 8-bit ASCII as not printable for this 116 * application. 117 */ 118 static void 119 stream_bytes(FILE *fp, const char *string) 120 { 121 char c; 122 123 while ((c = *string++) != '\0') { 124 if (c > ' ' && c != '\\' && c < '\177') { 125 (void) fprintf(fp, "%c", c); 126 } else { 127 (void) fprintf(fp, "\\%04o", (uint8_t)c); 128 } 129 } 130 } 131 132 static void 133 print_what(FILE *fp, mode_t what) 134 { 135 char symbol; 136 137 switch (what & S_IFMT) { 138 case S_IFBLK: 139 symbol = 'B'; 140 break; 141 case S_IFCHR: 142 symbol = 'C'; 143 break; 144 case S_IFDIR: 145 symbol = '/'; 146 break; 147 #ifdef S_IFDOOR 148 case S_IFDOOR: 149 symbol = '>'; 150 break; 151 #endif 152 case S_IFIFO: 153 symbol = '|'; 154 break; 155 case S_IFLNK: 156 symbol = '@'; 157 break; 158 #ifdef S_IFPORT 159 case S_IFPORT: 160 symbol = 'P'; 161 break; 162 #endif 163 case S_IFSOCK: 164 symbol = '='; 165 break; 166 case S_IFREG: 167 symbol = 'F'; 168 break; 169 default: 170 symbol = '?'; 171 break; 172 } 173 (void) fprintf(fp, "%c", symbol); 174 } 175 176 static void 177 print_cmn(FILE *fp, differ_info_t *di, const char *file) 178 { 179 stream_bytes(fp, di->dsmnt); 180 stream_bytes(fp, file); 181 } 182 183 static void 184 print_rename(FILE *fp, differ_info_t *di, const char *old, const char *new, 185 zfs_stat_t *isb) 186 { 187 if (di->timestamped) 188 (void) fprintf(fp, "%10lld.%09lld\t", 189 (longlong_t)isb->zs_ctime[0], 190 (longlong_t)isb->zs_ctime[1]); 191 (void) fprintf(fp, "%c\t", ZDIFF_RENAMED); 192 if (di->classify) { 193 print_what(fp, isb->zs_mode); 194 (void) fprintf(fp, "\t"); 195 } 196 print_cmn(fp, di, old); 197 if (di->scripted) 198 (void) fprintf(fp, "\t"); 199 else 200 (void) fprintf(fp, " -> "); 201 print_cmn(fp, di, new); 202 (void) fprintf(fp, "\n"); 203 } 204 205 static void 206 print_link_change(FILE *fp, differ_info_t *di, int delta, const char *file, 207 zfs_stat_t *isb) 208 { 209 if (di->timestamped) 210 (void) fprintf(fp, "%10lld.%09lld\t", 211 (longlong_t)isb->zs_ctime[0], 212 (longlong_t)isb->zs_ctime[1]); 213 (void) fprintf(fp, "%c\t", ZDIFF_MODIFIED); 214 if (di->classify) { 215 print_what(fp, isb->zs_mode); 216 (void) fprintf(fp, "\t"); 217 } 218 print_cmn(fp, di, file); 219 (void) fprintf(fp, "\t(%+d)", delta); 220 (void) fprintf(fp, "\n"); 221 } 222 223 static void 224 print_file(FILE *fp, differ_info_t *di, char type, const char *file, 225 zfs_stat_t *isb) 226 { 227 if (di->timestamped) 228 (void) fprintf(fp, "%10lld.%09lld\t", 229 (longlong_t)isb->zs_ctime[0], 230 (longlong_t)isb->zs_ctime[1]); 231 (void) fprintf(fp, "%c\t", type); 232 if (di->classify) { 233 print_what(fp, isb->zs_mode); 234 (void) fprintf(fp, "\t"); 235 } 236 print_cmn(fp, di, file); 237 (void) fprintf(fp, "\n"); 238 } 239 240 static int 241 write_inuse_diffs_one(FILE *fp, differ_info_t *di, uint64_t dobj) 242 { 243 struct zfs_stat fsb, tsb; 244 mode_t fmode, tmode; 245 char fobjname[MAXPATHLEN], tobjname[MAXPATHLEN]; 246 boolean_t already_logged = B_FALSE; 247 int fobjerr, tobjerr; 248 int change; 249 250 if (dobj == di->shares) 251 return (0); 252 253 /* 254 * Check the from and to snapshots for info on the object. If 255 * we get ENOENT, then the object just didn't exist in that 256 * snapshot. If we get ENOTSUP, then we tried to get 257 * info on a non-ZPL object, which we don't care about anyway. 258 * For any other error we print a warning which includes the 259 * errno and continue. 260 */ 261 262 fobjerr = get_stats_for_obj(di, di->fromsnap, dobj, fobjname, 263 MAXPATHLEN, &fsb); 264 if (fobjerr && di->zerr != ENOTSUP && di->zerr != ENOENT) { 265 zfs_error_aux(di->zhp->zfs_hdl, "%s", strerror(di->zerr)); 266 zfs_error(di->zhp->zfs_hdl, di->zerr, di->errbuf); 267 /* 268 * Let's not print an error for the same object more than 269 * once if it happens in both snapshots 270 */ 271 already_logged = B_TRUE; 272 } 273 274 tobjerr = get_stats_for_obj(di, di->tosnap, dobj, tobjname, 275 MAXPATHLEN, &tsb); 276 277 if (tobjerr && di->zerr != ENOTSUP && di->zerr != ENOENT) { 278 if (!already_logged) { 279 zfs_error_aux(di->zhp->zfs_hdl, 280 "%s", strerror(di->zerr)); 281 zfs_error(di->zhp->zfs_hdl, di->zerr, di->errbuf); 282 } 283 } 284 /* 285 * Unallocated object sharing the same meta dnode block 286 */ 287 if (fobjerr && tobjerr) { 288 di->zerr = 0; 289 return (0); 290 } 291 292 di->zerr = 0; /* negate get_stats_for_obj() from side that failed */ 293 fmode = fsb.zs_mode & S_IFMT; 294 tmode = tsb.zs_mode & S_IFMT; 295 if (fmode == S_IFDIR || tmode == S_IFDIR || fsb.zs_links == 0 || 296 tsb.zs_links == 0) 297 change = 0; 298 else 299 change = tsb.zs_links - fsb.zs_links; 300 301 if (fobjerr) { 302 if (change) { 303 print_link_change(fp, di, change, tobjname, &tsb); 304 return (0); 305 } 306 print_file(fp, di, ZDIFF_ADDED, tobjname, &tsb); 307 return (0); 308 } else if (tobjerr) { 309 if (change) { 310 print_link_change(fp, di, change, fobjname, &fsb); 311 return (0); 312 } 313 print_file(fp, di, ZDIFF_REMOVED, fobjname, &fsb); 314 return (0); 315 } 316 317 if (fmode != tmode && fsb.zs_gen == tsb.zs_gen) 318 tsb.zs_gen++; /* Force a generational difference */ 319 320 /* Simple modification or no change */ 321 if (fsb.zs_gen == tsb.zs_gen) { 322 /* No apparent changes. Could we assert !this? */ 323 if (fsb.zs_ctime[0] == tsb.zs_ctime[0] && 324 fsb.zs_ctime[1] == tsb.zs_ctime[1]) 325 return (0); 326 if (change) { 327 print_link_change(fp, di, change, 328 change > 0 ? fobjname : tobjname, &tsb); 329 } else if (strcmp(fobjname, tobjname) == 0) { 330 print_file(fp, di, ZDIFF_MODIFIED, fobjname, &tsb); 331 } else { 332 print_rename(fp, di, fobjname, tobjname, &tsb); 333 } 334 return (0); 335 } else { 336 /* file re-created or object re-used */ 337 print_file(fp, di, ZDIFF_REMOVED, fobjname, &fsb); 338 print_file(fp, di, ZDIFF_ADDED, tobjname, &tsb); 339 return (0); 340 } 341 } 342 343 static int 344 write_inuse_diffs(FILE *fp, differ_info_t *di, dmu_diff_record_t *dr) 345 { 346 uint64_t o; 347 int err; 348 349 for (o = dr->ddr_first; o <= dr->ddr_last; o++) { 350 if ((err = write_inuse_diffs_one(fp, di, o)) != 0) 351 return (err); 352 } 353 return (0); 354 } 355 356 static int 357 describe_free(FILE *fp, differ_info_t *di, uint64_t object, char *namebuf, 358 int maxlen) 359 { 360 struct zfs_stat sb; 361 362 (void) get_stats_for_obj(di, di->fromsnap, object, namebuf, 363 maxlen, &sb); 364 365 /* Don't print if in the delete queue on from side */ 366 if (di->zerr == ESTALE || di->zerr == ENOENT) { 367 di->zerr = 0; 368 return (0); 369 } 370 371 print_file(fp, di, ZDIFF_REMOVED, namebuf, &sb); 372 return (0); 373 } 374 375 static int 376 write_free_diffs(FILE *fp, differ_info_t *di, dmu_diff_record_t *dr) 377 { 378 zfs_cmd_t zc = {"\0"}; 379 libzfs_handle_t *lhdl = di->zhp->zfs_hdl; 380 char fobjname[MAXPATHLEN]; 381 382 (void) strlcpy(zc.zc_name, di->fromsnap, sizeof (zc.zc_name)); 383 zc.zc_obj = dr->ddr_first - 1; 384 385 ASSERT(di->zerr == 0); 386 387 while (zc.zc_obj < dr->ddr_last) { 388 int err; 389 390 err = zfs_ioctl(lhdl, ZFS_IOC_NEXT_OBJ, &zc); 391 if (err == 0) { 392 if (zc.zc_obj == di->shares) { 393 zc.zc_obj++; 394 continue; 395 } 396 if (zc.zc_obj > dr->ddr_last) { 397 break; 398 } 399 err = describe_free(fp, di, zc.zc_obj, fobjname, 400 MAXPATHLEN); 401 } else if (errno == ESRCH) { 402 break; 403 } else { 404 (void) snprintf(di->errbuf, sizeof (di->errbuf), 405 dgettext(TEXT_DOMAIN, 406 "next allocated object (> %lld) find failure"), 407 (longlong_t)zc.zc_obj); 408 di->zerr = errno; 409 break; 410 } 411 } 412 if (di->zerr) 413 return (-1); 414 return (0); 415 } 416 417 static void * 418 differ(void *arg) 419 { 420 differ_info_t *di = arg; 421 dmu_diff_record_t dr; 422 FILE *ofp; 423 int err = 0; 424 425 if ((ofp = fdopen(di->outputfd, "w")) == NULL) { 426 di->zerr = errno; 427 strlcpy(di->errbuf, strerror(errno), sizeof (di->errbuf)); 428 (void) close(di->datafd); 429 return ((void *)-1); 430 } 431 432 for (;;) { 433 char *cp = (char *)&dr; 434 int len = sizeof (dr); 435 int rv; 436 437 do { 438 rv = read(di->datafd, cp, len); 439 cp += rv; 440 len -= rv; 441 } while (len > 0 && rv > 0); 442 443 if (rv < 0 || (rv == 0 && len != sizeof (dr))) { 444 di->zerr = EPIPE; 445 break; 446 } else if (rv == 0) { 447 /* end of file at a natural breaking point */ 448 break; 449 } 450 451 switch (dr.ddr_type) { 452 case DDR_FREE: 453 err = write_free_diffs(ofp, di, &dr); 454 break; 455 case DDR_INUSE: 456 err = write_inuse_diffs(ofp, di, &dr); 457 break; 458 default: 459 di->zerr = EPIPE; 460 break; 461 } 462 463 if (err || di->zerr) 464 break; 465 } 466 467 (void) fclose(ofp); 468 (void) close(di->datafd); 469 if (err) 470 return ((void *)-1); 471 if (di->zerr) { 472 ASSERT(di->zerr == EPIPE); 473 (void) snprintf(di->errbuf, sizeof (di->errbuf), 474 dgettext(TEXT_DOMAIN, 475 "Internal error: bad data from diff IOCTL")); 476 return ((void *)-1); 477 } 478 return ((void *)0); 479 } 480 481 static int 482 make_temp_snapshot(differ_info_t *di) 483 { 484 libzfs_handle_t *hdl = di->zhp->zfs_hdl; 485 zfs_cmd_t zc = {"\0"}; 486 487 (void) snprintf(zc.zc_value, sizeof (zc.zc_value), 488 ZDIFF_PREFIX, getpid()); 489 (void) strlcpy(zc.zc_name, di->ds, sizeof (zc.zc_name)); 490 zc.zc_cleanup_fd = di->cleanupfd; 491 492 if (zfs_ioctl(hdl, ZFS_IOC_TMP_SNAPSHOT, &zc) != 0) { 493 int err = errno; 494 if (err == EPERM) { 495 (void) snprintf(di->errbuf, sizeof (di->errbuf), 496 dgettext(TEXT_DOMAIN, "The diff delegated " 497 "permission is needed in order\nto create a " 498 "just-in-time snapshot for diffing\n")); 499 return (zfs_error(hdl, EZFS_DIFF, di->errbuf)); 500 } else { 501 (void) snprintf(di->errbuf, sizeof (di->errbuf), 502 dgettext(TEXT_DOMAIN, "Cannot create just-in-time " 503 "snapshot of '%s'"), zc.zc_name); 504 return (zfs_standard_error(hdl, err, di->errbuf)); 505 } 506 } 507 508 di->tmpsnap = zfs_strdup(hdl, zc.zc_value); 509 di->tosnap = zfs_asprintf(hdl, "%s@%s", di->ds, di->tmpsnap); 510 return (0); 511 } 512 513 static void 514 teardown_differ_info(differ_info_t *di) 515 { 516 free(di->ds); 517 free(di->dsmnt); 518 free(di->fromsnap); 519 free(di->frommnt); 520 free(di->tosnap); 521 free(di->tmpsnap); 522 free(di->tomnt); 523 (void) close(di->cleanupfd); 524 } 525 526 static int 527 get_snapshot_names(differ_info_t *di, const char *fromsnap, 528 const char *tosnap) 529 { 530 libzfs_handle_t *hdl = di->zhp->zfs_hdl; 531 char *atptrf = NULL; 532 char *atptrt = NULL; 533 int fdslen, fsnlen; 534 int tdslen, tsnlen; 535 536 /* 537 * Can accept 538 * fdslen fsnlen tdslen tsnlen 539 * dataset@snap1 540 * 0. dataset@snap1 dataset@snap2 >0 >1 >0 >1 541 * 1. dataset@snap1 @snap2 >0 >1 ==0 >1 542 * 2. dataset@snap1 dataset >0 >1 >0 ==0 543 * 3. @snap1 dataset@snap2 ==0 >1 >0 >1 544 * 4. @snap1 dataset ==0 >1 >0 ==0 545 */ 546 if (tosnap == NULL) { 547 /* only a from snapshot given, must be valid */ 548 (void) snprintf(di->errbuf, sizeof (di->errbuf), 549 dgettext(TEXT_DOMAIN, 550 "Badly formed snapshot name %s"), fromsnap); 551 552 if (!zfs_validate_name(hdl, fromsnap, ZFS_TYPE_SNAPSHOT, 553 B_FALSE)) { 554 return (zfs_error(hdl, EZFS_INVALIDNAME, 555 di->errbuf)); 556 } 557 558 atptrf = strchr(fromsnap, '@'); 559 ASSERT(atptrf != NULL); 560 fdslen = atptrf - fromsnap; 561 562 di->fromsnap = zfs_strdup(hdl, fromsnap); 563 di->ds = zfs_strdup(hdl, fromsnap); 564 di->ds[fdslen] = '\0'; 565 566 /* the to snap will be a just-in-time snap of the head */ 567 return (make_temp_snapshot(di)); 568 } 569 570 (void) snprintf(di->errbuf, sizeof (di->errbuf), 571 dgettext(TEXT_DOMAIN, 572 "Unable to determine which snapshots to compare")); 573 574 atptrf = strchr(fromsnap, '@'); 575 atptrt = strchr(tosnap, '@'); 576 fdslen = atptrf ? atptrf - fromsnap : strlen(fromsnap); 577 tdslen = atptrt ? atptrt - tosnap : strlen(tosnap); 578 fsnlen = strlen(fromsnap) - fdslen; /* includes @ sign */ 579 tsnlen = strlen(tosnap) - tdslen; /* includes @ sign */ 580 581 if (fsnlen <= 1 || tsnlen == 1 || (fdslen == 0 && tdslen == 0)) { 582 return (zfs_error(hdl, EZFS_INVALIDNAME, di->errbuf)); 583 } else if ((fdslen > 0 && tdslen > 0) && 584 ((tdslen != fdslen || strncmp(fromsnap, tosnap, fdslen) != 0))) { 585 /* 586 * not the same dataset name, might be okay if 587 * tosnap is a clone of a fromsnap descendant. 588 */ 589 char origin[ZFS_MAX_DATASET_NAME_LEN]; 590 zprop_source_t src; 591 zfs_handle_t *zhp; 592 593 di->ds = zfs_alloc(di->zhp->zfs_hdl, tdslen + 1); 594 (void) strncpy(di->ds, tosnap, tdslen); 595 di->ds[tdslen] = '\0'; 596 597 zhp = zfs_open(hdl, di->ds, ZFS_TYPE_FILESYSTEM); 598 while (zhp != NULL) { 599 if (zfs_prop_get(zhp, ZFS_PROP_ORIGIN, origin, 600 sizeof (origin), &src, NULL, 0, B_FALSE) != 0) { 601 (void) zfs_close(zhp); 602 zhp = NULL; 603 break; 604 } 605 if (strncmp(origin, fromsnap, fsnlen) == 0) 606 break; 607 608 (void) zfs_close(zhp); 609 zhp = zfs_open(hdl, origin, ZFS_TYPE_FILESYSTEM); 610 } 611 612 if (zhp == NULL) { 613 (void) snprintf(di->errbuf, sizeof (di->errbuf), 614 dgettext(TEXT_DOMAIN, 615 "Not an earlier snapshot from the same fs")); 616 return (zfs_error(hdl, EZFS_INVALIDNAME, di->errbuf)); 617 } else { 618 (void) zfs_close(zhp); 619 } 620 621 di->isclone = B_TRUE; 622 di->fromsnap = zfs_strdup(hdl, fromsnap); 623 if (tsnlen) { 624 di->tosnap = zfs_strdup(hdl, tosnap); 625 } else { 626 return (make_temp_snapshot(di)); 627 } 628 } else { 629 int dslen = fdslen ? fdslen : tdslen; 630 631 di->ds = zfs_alloc(hdl, dslen + 1); 632 (void) strncpy(di->ds, fdslen ? fromsnap : tosnap, dslen); 633 di->ds[dslen] = '\0'; 634 635 di->fromsnap = zfs_asprintf(hdl, "%s%s", di->ds, atptrf); 636 if (tsnlen) { 637 di->tosnap = zfs_asprintf(hdl, "%s%s", di->ds, atptrt); 638 } else { 639 return (make_temp_snapshot(di)); 640 } 641 } 642 return (0); 643 } 644 645 static int 646 get_mountpoint(differ_info_t *di, char *dsnm, char **mntpt) 647 { 648 boolean_t mounted; 649 650 mounted = is_mounted(di->zhp->zfs_hdl, dsnm, mntpt); 651 if (mounted == B_FALSE) { 652 (void) snprintf(di->errbuf, sizeof (di->errbuf), 653 dgettext(TEXT_DOMAIN, 654 "Cannot diff an unmounted snapshot")); 655 return (zfs_error(di->zhp->zfs_hdl, EZFS_BADTYPE, di->errbuf)); 656 } 657 658 /* Avoid a double slash at the beginning of root-mounted datasets */ 659 if (**mntpt == '/' && *(*mntpt + 1) == '\0') 660 **mntpt = '\0'; 661 return (0); 662 } 663 664 static int 665 get_mountpoints(differ_info_t *di) 666 { 667 char *strptr; 668 char *frommntpt; 669 670 /* 671 * first get the mountpoint for the parent dataset 672 */ 673 if (get_mountpoint(di, di->ds, &di->dsmnt) != 0) 674 return (-1); 675 676 strptr = strchr(di->tosnap, '@'); 677 ASSERT3P(strptr, !=, NULL); 678 di->tomnt = zfs_asprintf(di->zhp->zfs_hdl, "%s%s%s", di->dsmnt, 679 ZDIFF_SNAPDIR, ++strptr); 680 681 strptr = strchr(di->fromsnap, '@'); 682 ASSERT3P(strptr, !=, NULL); 683 684 frommntpt = di->dsmnt; 685 if (di->isclone) { 686 char *mntpt; 687 int err; 688 689 *strptr = '\0'; 690 err = get_mountpoint(di, di->fromsnap, &mntpt); 691 *strptr = '@'; 692 if (err != 0) 693 return (-1); 694 frommntpt = mntpt; 695 } 696 697 di->frommnt = zfs_asprintf(di->zhp->zfs_hdl, "%s%s%s", frommntpt, 698 ZDIFF_SNAPDIR, ++strptr); 699 700 if (di->isclone) 701 free(frommntpt); 702 703 return (0); 704 } 705 706 static int 707 setup_differ_info(zfs_handle_t *zhp, const char *fromsnap, 708 const char *tosnap, differ_info_t *di) 709 { 710 di->zhp = zhp; 711 712 di->cleanupfd = open(ZFS_DEV, O_RDWR | O_CLOEXEC); 713 VERIFY(di->cleanupfd >= 0); 714 715 if (get_snapshot_names(di, fromsnap, tosnap) != 0) 716 return (-1); 717 718 if (get_mountpoints(di) != 0) 719 return (-1); 720 721 if (find_shares_object(di) != 0) 722 return (-1); 723 724 return (0); 725 } 726 727 int 728 zfs_show_diffs(zfs_handle_t *zhp, int outfd, const char *fromsnap, 729 const char *tosnap, int flags) 730 { 731 zfs_cmd_t zc = {"\0"}; 732 char errbuf[1024]; 733 differ_info_t di = { 0 }; 734 pthread_t tid; 735 int pipefd[2]; 736 int iocerr; 737 738 (void) snprintf(errbuf, sizeof (errbuf), 739 dgettext(TEXT_DOMAIN, "zfs diff failed")); 740 741 if (setup_differ_info(zhp, fromsnap, tosnap, &di)) { 742 teardown_differ_info(&di); 743 return (-1); 744 } 745 746 if (pipe2(pipefd, O_CLOEXEC)) { 747 zfs_error_aux(zhp->zfs_hdl, "%s", strerror(errno)); 748 teardown_differ_info(&di); 749 return (zfs_error(zhp->zfs_hdl, EZFS_PIPEFAILED, errbuf)); 750 } 751 752 di.scripted = (flags & ZFS_DIFF_PARSEABLE); 753 di.classify = (flags & ZFS_DIFF_CLASSIFY); 754 di.timestamped = (flags & ZFS_DIFF_TIMESTAMP); 755 756 di.outputfd = outfd; 757 di.datafd = pipefd[0]; 758 759 if (pthread_create(&tid, NULL, differ, &di)) { 760 zfs_error_aux(zhp->zfs_hdl, "%s", strerror(errno)); 761 (void) close(pipefd[0]); 762 (void) close(pipefd[1]); 763 teardown_differ_info(&di); 764 return (zfs_error(zhp->zfs_hdl, 765 EZFS_THREADCREATEFAILED, errbuf)); 766 } 767 768 /* do the ioctl() */ 769 (void) strlcpy(zc.zc_value, di.fromsnap, strlen(di.fromsnap) + 1); 770 (void) strlcpy(zc.zc_name, di.tosnap, strlen(di.tosnap) + 1); 771 zc.zc_cookie = pipefd[1]; 772 773 iocerr = zfs_ioctl(zhp->zfs_hdl, ZFS_IOC_DIFF, &zc); 774 if (iocerr != 0) { 775 (void) snprintf(errbuf, sizeof (errbuf), 776 dgettext(TEXT_DOMAIN, "Unable to obtain diffs")); 777 if (errno == EPERM) { 778 zfs_error_aux(zhp->zfs_hdl, dgettext(TEXT_DOMAIN, 779 "\n The sys_mount privilege or diff delegated " 780 "permission is needed\n to execute the " 781 "diff ioctl")); 782 } else if (errno == EXDEV) { 783 zfs_error_aux(zhp->zfs_hdl, dgettext(TEXT_DOMAIN, 784 "\n Not an earlier snapshot from the same fs")); 785 } else if (errno != EPIPE || di.zerr == 0) { 786 zfs_error_aux(zhp->zfs_hdl, "%s", strerror(errno)); 787 } 788 (void) close(pipefd[1]); 789 (void) pthread_cancel(tid); 790 (void) pthread_join(tid, NULL); 791 teardown_differ_info(&di); 792 if (di.zerr != 0 && di.zerr != EPIPE) { 793 zfs_error_aux(zhp->zfs_hdl, "%s", strerror(di.zerr)); 794 return (zfs_error(zhp->zfs_hdl, EZFS_DIFF, di.errbuf)); 795 } else { 796 return (zfs_error(zhp->zfs_hdl, EZFS_DIFFDATA, errbuf)); 797 } 798 } 799 800 (void) close(pipefd[1]); 801 (void) pthread_join(tid, NULL); 802 803 if (di.zerr != 0) { 804 zfs_error_aux(zhp->zfs_hdl, "%s", strerror(di.zerr)); 805 return (zfs_error(zhp->zfs_hdl, EZFS_DIFF, di.errbuf)); 806 } 807 teardown_differ_info(&di); 808 return (0); 809 } 810