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