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 */ 25 26 /* 27 * zfs diff support 28 */ 29 #include <ctype.h> 30 #include <errno.h> 31 #include <libintl.h> 32 #include <string.h> 33 #include <sys/types.h> 34 #include <sys/stat.h> 35 #include <fcntl.h> 36 #include <attr.h> 37 #include <stddef.h> 38 #include <unistd.h> 39 #include <stdio.h> 40 #include <stdlib.h> 41 #include <stropts.h> 42 #include <pthread.h> 43 #include <sys/zfs_ioctl.h> 44 #include <libzfs.h> 45 #include "libzfs_impl.h" 46 47 #define ZDIFF_SNAPDIR "/.zfs/snapshot/" 48 #define ZDIFF_SHARESDIR "/.zfs/shares/" 49 #define ZDIFF_PREFIX "zfs-diff-%d" 50 51 #define ZDIFF_ADDED '+' 52 #define ZDIFF_MODIFIED 'M' 53 #define ZDIFF_REMOVED '-' 54 #define ZDIFF_RENAMED 'R' 55 56 static boolean_t 57 do_name_cmp(const char *fpath, const char *tpath) 58 { 59 char *fname, *tname; 60 fname = strrchr(fpath, '/') + 1; 61 tname = strrchr(tpath, '/') + 1; 62 return (strcmp(fname, tname) == 0); 63 } 64 65 typedef struct differ_info { 66 zfs_handle_t *zhp; 67 char *fromsnap; 68 char *frommnt; 69 char *tosnap; 70 char *tomnt; 71 char *ds; 72 char *dsmnt; 73 char *tmpsnap; 74 char errbuf[1024]; 75 boolean_t isclone; 76 boolean_t scripted; 77 boolean_t classify; 78 boolean_t timestamped; 79 uint64_t shares; 80 int zerr; 81 int cleanupfd; 82 int outputfd; 83 int datafd; 84 } differ_info_t; 85 86 /* 87 * Given a {dsname, object id}, get the object path 88 */ 89 static int 90 get_stats_for_obj(differ_info_t *di, const char *dsname, uint64_t obj, 91 char *pn, int maxlen, zfs_stat_t *sb) 92 { 93 zfs_cmd_t zc = { 0 }; 94 int error; 95 96 (void) strlcpy(zc.zc_name, dsname, sizeof (zc.zc_name)); 97 zc.zc_obj = obj; 98 99 errno = 0; 100 error = ioctl(di->zhp->zfs_hdl->libzfs_fd, ZFS_IOC_OBJ_TO_STATS, &zc); 101 di->zerr = errno; 102 103 /* we can get stats even if we failed to get a path */ 104 (void) memcpy(sb, &zc.zc_stat, sizeof (zfs_stat_t)); 105 if (error == 0) { 106 ASSERT(di->zerr == 0); 107 (void) strlcpy(pn, zc.zc_value, maxlen); 108 return (0); 109 } 110 111 if (di->zerr == EPERM) { 112 (void) snprintf(di->errbuf, sizeof (di->errbuf), 113 dgettext(TEXT_DOMAIN, 114 "The sys_config privilege or diff delegated permission " 115 "is needed\nto discover path names")); 116 return (-1); 117 } else { 118 (void) snprintf(di->errbuf, sizeof (di->errbuf), 119 dgettext(TEXT_DOMAIN, 120 "Unable to determine path or stats for " 121 "object %lld in %s"), obj, dsname); 122 return (-1); 123 } 124 } 125 126 /* 127 * stream_bytes 128 * 129 * Prints a file name out a character at a time. If the character is 130 * not in the range of what we consider "printable" ASCII, display it 131 * as an escaped 3-digit octal value. ASCII values less than a space 132 * are all control characters and we declare the upper end as the 133 * DELete character. This also is the last 7-bit ASCII character. 134 * We choose to treat all 8-bit ASCII as not printable for this 135 * application. 136 */ 137 static void 138 stream_bytes(FILE *fp, const char *string) 139 { 140 while (*string) { 141 if (*string > ' ' && *string != '\\' && *string < '\177') 142 (void) fprintf(fp, "%c", *string++); 143 else 144 (void) fprintf(fp, "\\%03o", *string++); 145 } 146 } 147 148 static void 149 print_what(FILE *fp, mode_t what) 150 { 151 char symbol; 152 153 switch (what & S_IFMT) { 154 case S_IFBLK: 155 symbol = 'B'; 156 break; 157 case S_IFCHR: 158 symbol = 'C'; 159 break; 160 case S_IFDIR: 161 symbol = '/'; 162 break; 163 case S_IFDOOR: 164 symbol = '>'; 165 break; 166 case S_IFIFO: 167 symbol = '|'; 168 break; 169 case S_IFLNK: 170 symbol = '@'; 171 break; 172 case S_IFPORT: 173 symbol = 'P'; 174 break; 175 case S_IFSOCK: 176 symbol = '='; 177 break; 178 case S_IFREG: 179 symbol = 'F'; 180 break; 181 default: 182 symbol = '?'; 183 break; 184 } 185 (void) fprintf(fp, "%c", symbol); 186 } 187 188 static void 189 print_cmn(FILE *fp, differ_info_t *di, const char *file) 190 { 191 stream_bytes(fp, di->dsmnt); 192 stream_bytes(fp, file); 193 } 194 195 static void 196 print_rename(FILE *fp, differ_info_t *di, const char *old, const char *new, 197 zfs_stat_t *isb) 198 { 199 if (di->timestamped) 200 (void) fprintf(fp, "%10lld.%09lld\t", 201 (longlong_t)isb->zs_ctime[0], 202 (longlong_t)isb->zs_ctime[1]); 203 (void) fprintf(fp, "%c\t", ZDIFF_RENAMED); 204 if (di->classify) { 205 print_what(fp, isb->zs_mode); 206 (void) fprintf(fp, "\t"); 207 } 208 print_cmn(fp, di, old); 209 if (di->scripted) 210 (void) fprintf(fp, "\t"); 211 else 212 (void) fprintf(fp, " -> "); 213 print_cmn(fp, di, new); 214 (void) fprintf(fp, "\n"); 215 } 216 217 static void 218 print_link_change(FILE *fp, differ_info_t *di, int delta, const char *file, 219 zfs_stat_t *isb) 220 { 221 if (di->timestamped) 222 (void) fprintf(fp, "%10lld.%09lld\t", 223 (longlong_t)isb->zs_ctime[0], 224 (longlong_t)isb->zs_ctime[1]); 225 (void) fprintf(fp, "%c\t", ZDIFF_MODIFIED); 226 if (di->classify) { 227 print_what(fp, isb->zs_mode); 228 (void) fprintf(fp, "\t"); 229 } 230 print_cmn(fp, di, file); 231 (void) fprintf(fp, "\t(%+d)", delta); 232 (void) fprintf(fp, "\n"); 233 } 234 235 static void 236 print_file(FILE *fp, differ_info_t *di, char type, const char *file, 237 zfs_stat_t *isb) 238 { 239 if (di->timestamped) 240 (void) fprintf(fp, "%10lld.%09lld\t", 241 (longlong_t)isb->zs_ctime[0], 242 (longlong_t)isb->zs_ctime[1]); 243 (void) fprintf(fp, "%c\t", type); 244 if (di->classify) { 245 print_what(fp, isb->zs_mode); 246 (void) fprintf(fp, "\t"); 247 } 248 print_cmn(fp, di, file); 249 (void) fprintf(fp, "\n"); 250 } 251 252 static int 253 write_inuse_diffs_one(FILE *fp, differ_info_t *di, uint64_t dobj) 254 { 255 struct zfs_stat fsb, tsb; 256 boolean_t same_name; 257 mode_t fmode, tmode; 258 char fobjname[MAXPATHLEN], tobjname[MAXPATHLEN]; 259 int fobjerr, tobjerr; 260 int change; 261 262 if (dobj == di->shares) 263 return (0); 264 265 /* 266 * Check the from and to snapshots for info on the object. If 267 * we get ENOENT, then the object just didn't exist in that 268 * snapshot. If we get ENOTSUP, then we tried to get 269 * info on a non-ZPL object, which we don't care about anyway. 270 */ 271 fobjerr = get_stats_for_obj(di, di->fromsnap, dobj, fobjname, 272 MAXPATHLEN, &fsb); 273 if (fobjerr && di->zerr != ENOENT && di->zerr != ENOTSUP) 274 return (-1); 275 276 tobjerr = get_stats_for_obj(di, di->tosnap, dobj, tobjname, 277 MAXPATHLEN, &tsb); 278 if (tobjerr && di->zerr != ENOENT && di->zerr != ENOTSUP) 279 return (-1); 280 281 /* 282 * Unallocated object sharing the same meta dnode block 283 */ 284 if (fobjerr && tobjerr) { 285 ASSERT(di->zerr == ENOENT || di->zerr == ENOTSUP); 286 di->zerr = 0; 287 return (0); 288 } 289 290 di->zerr = 0; /* negate get_stats_for_obj() from side that failed */ 291 fmode = fsb.zs_mode & S_IFMT; 292 tmode = tsb.zs_mode & S_IFMT; 293 if (fmode == S_IFDIR || tmode == S_IFDIR || fsb.zs_links == 0 || 294 tsb.zs_links == 0) 295 change = 0; 296 else 297 change = tsb.zs_links - fsb.zs_links; 298 299 if (fobjerr) { 300 if (change) { 301 print_link_change(fp, di, change, tobjname, &tsb); 302 return (0); 303 } 304 print_file(fp, di, ZDIFF_ADDED, tobjname, &tsb); 305 return (0); 306 } else if (tobjerr) { 307 if (change) { 308 print_link_change(fp, di, change, fobjname, &fsb); 309 return (0); 310 } 311 print_file(fp, di, ZDIFF_REMOVED, fobjname, &fsb); 312 return (0); 313 } 314 315 if (fmode != tmode && fsb.zs_gen == tsb.zs_gen) 316 tsb.zs_gen++; /* Force a generational difference */ 317 same_name = do_name_cmp(fobjname, tobjname); 318 319 /* Simple modification or no change */ 320 if (fsb.zs_gen == tsb.zs_gen) { 321 /* No apparent changes. Could we assert !this? */ 322 if (fsb.zs_ctime[0] == tsb.zs_ctime[0] && 323 fsb.zs_ctime[1] == tsb.zs_ctime[1]) 324 return (0); 325 if (change) { 326 print_link_change(fp, di, change, 327 change > 0 ? fobjname : tobjname, &tsb); 328 } else if (same_name) { 329 print_file(fp, di, ZDIFF_MODIFIED, fobjname, &tsb); 330 } else { 331 print_rename(fp, di, fobjname, tobjname, &tsb); 332 } 333 return (0); 334 } else { 335 /* file re-created or object re-used */ 336 print_file(fp, di, ZDIFF_REMOVED, fobjname, &fsb); 337 print_file(fp, di, ZDIFF_ADDED, tobjname, &tsb); 338 return (0); 339 } 340 } 341 342 static int 343 write_inuse_diffs(FILE *fp, differ_info_t *di, dmu_diff_record_t *dr) 344 { 345 uint64_t o; 346 int err; 347 348 for (o = dr->ddr_first; o <= dr->ddr_last; o++) { 349 if (err = write_inuse_diffs_one(fp, di, o)) 350 return (err); 351 } 352 return (0); 353 } 354 355 static int 356 describe_free(FILE *fp, differ_info_t *di, uint64_t object, char *namebuf, 357 int maxlen) 358 { 359 struct zfs_stat sb; 360 361 if (get_stats_for_obj(di, di->fromsnap, object, namebuf, 362 maxlen, &sb) != 0) { 363 /* Let it slide, if in the delete queue on from side */ 364 if (di->zerr == ENOENT && sb.zs_links == 0) { 365 di->zerr = 0; 366 return (0); 367 } 368 return (-1); 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 = ioctl(lhdl->libzfs_fd, 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 if (err) 402 break; 403 } else if (errno == ESRCH) { 404 break; 405 } else { 406 (void) snprintf(di->errbuf, sizeof (di->errbuf), 407 dgettext(TEXT_DOMAIN, 408 "next allocated object (> %lld) find failure"), 409 zc.zc_obj); 410 di->zerr = errno; 411 break; 412 } 413 } 414 if (di->zerr) 415 return (-1); 416 return (0); 417 } 418 419 static void * 420 differ(void *arg) 421 { 422 differ_info_t *di = arg; 423 dmu_diff_record_t dr; 424 FILE *ofp; 425 int err = 0; 426 427 if ((ofp = fdopen(di->outputfd, "w")) == NULL) { 428 di->zerr = errno; 429 (void) strerror_r(errno, di->errbuf, sizeof (di->errbuf)); 430 (void) close(di->datafd); 431 return ((void *)-1); 432 } 433 434 for (;;) { 435 char *cp = (char *)&dr; 436 int len = sizeof (dr); 437 int rv; 438 439 do { 440 rv = read(di->datafd, cp, len); 441 cp += rv; 442 len -= rv; 443 } while (len > 0 && rv > 0); 444 445 if (rv < 0 || (rv == 0 && len != sizeof (dr))) { 446 di->zerr = EPIPE; 447 break; 448 } else if (rv == 0) { 449 /* end of file at a natural breaking point */ 450 break; 451 } 452 453 switch (dr.ddr_type) { 454 case DDR_FREE: 455 err = write_free_diffs(ofp, di, &dr); 456 break; 457 case DDR_INUSE: 458 err = write_inuse_diffs(ofp, di, &dr); 459 break; 460 default: 461 di->zerr = EPIPE; 462 break; 463 } 464 465 if (err || di->zerr) 466 break; 467 } 468 469 (void) fclose(ofp); 470 (void) close(di->datafd); 471 if (err) 472 return ((void *)-1); 473 if (di->zerr) { 474 ASSERT(di->zerr == EINVAL); 475 (void) snprintf(di->errbuf, sizeof (di->errbuf), 476 dgettext(TEXT_DOMAIN, 477 "Internal error: bad data from diff IOCTL")); 478 return ((void *)-1); 479 } 480 return ((void *)0); 481 } 482 483 static int 484 find_shares_object(differ_info_t *di) 485 { 486 char fullpath[MAXPATHLEN]; 487 struct stat64 sb = { 0 }; 488 489 (void) strlcpy(fullpath, di->dsmnt, MAXPATHLEN); 490 (void) strlcat(fullpath, ZDIFF_SHARESDIR, MAXPATHLEN); 491 492 if (stat64(fullpath, &sb) != 0) { 493 (void) snprintf(di->errbuf, sizeof (di->errbuf), 494 dgettext(TEXT_DOMAIN, "Cannot stat %s"), fullpath); 495 return (zfs_error(di->zhp->zfs_hdl, EZFS_DIFF, di->errbuf)); 496 } 497 498 di->shares = (uint64_t)sb.st_ino; 499 return (0); 500 } 501 502 static int 503 make_temp_snapshot(differ_info_t *di) 504 { 505 libzfs_handle_t *hdl = di->zhp->zfs_hdl; 506 zfs_cmd_t zc = { 0 }; 507 508 (void) snprintf(zc.zc_value, sizeof (zc.zc_value), 509 ZDIFF_PREFIX, getpid()); 510 (void) strlcpy(zc.zc_name, di->ds, sizeof (zc.zc_name)); 511 zc.zc_cleanup_fd = di->cleanupfd; 512 513 if (ioctl(hdl->libzfs_fd, ZFS_IOC_TMP_SNAPSHOT, &zc) != 0) { 514 int err = errno; 515 if (err == EPERM) { 516 (void) snprintf(di->errbuf, sizeof (di->errbuf), 517 dgettext(TEXT_DOMAIN, "The diff delegated " 518 "permission is needed in order\nto create a " 519 "just-in-time snapshot for diffing\n")); 520 return (zfs_error(hdl, EZFS_DIFF, di->errbuf)); 521 } else { 522 (void) snprintf(di->errbuf, sizeof (di->errbuf), 523 dgettext(TEXT_DOMAIN, "Cannot create just-in-time " 524 "snapshot of '%s'"), zc.zc_name); 525 return (zfs_standard_error(hdl, err, di->errbuf)); 526 } 527 } 528 529 di->tmpsnap = zfs_strdup(hdl, zc.zc_value); 530 di->tosnap = zfs_asprintf(hdl, "%s@%s", di->ds, di->tmpsnap); 531 return (0); 532 } 533 534 static void 535 teardown_differ_info(differ_info_t *di) 536 { 537 free(di->ds); 538 free(di->dsmnt); 539 free(di->fromsnap); 540 free(di->frommnt); 541 free(di->tosnap); 542 free(di->tmpsnap); 543 free(di->tomnt); 544 (void) close(di->cleanupfd); 545 } 546 547 static int 548 get_snapshot_names(differ_info_t *di, const char *fromsnap, 549 const char *tosnap) 550 { 551 libzfs_handle_t *hdl = di->zhp->zfs_hdl; 552 char *atptrf = NULL; 553 char *atptrt = NULL; 554 int fdslen, fsnlen; 555 int tdslen, tsnlen; 556 557 /* 558 * Can accept 559 * dataset@snap1 560 * dataset@snap1 dataset@snap2 561 * dataset@snap1 @snap2 562 * dataset@snap1 dataset 563 * @snap1 dataset@snap2 564 */ 565 if (tosnap == NULL) { 566 /* only a from snapshot given, must be valid */ 567 (void) snprintf(di->errbuf, sizeof (di->errbuf), 568 dgettext(TEXT_DOMAIN, 569 "Badly formed snapshot name %s"), fromsnap); 570 571 if (!zfs_validate_name(hdl, fromsnap, ZFS_TYPE_SNAPSHOT, 572 B_FALSE)) { 573 return (zfs_error(hdl, EZFS_INVALIDNAME, 574 di->errbuf)); 575 } 576 577 atptrf = strchr(fromsnap, '@'); 578 ASSERT(atptrf != NULL); 579 fdslen = atptrf - fromsnap; 580 581 di->fromsnap = zfs_strdup(hdl, fromsnap); 582 di->ds = zfs_strdup(hdl, fromsnap); 583 di->ds[fdslen] = '\0'; 584 585 /* the to snap will be a just-in-time snap of the head */ 586 return (make_temp_snapshot(di)); 587 } 588 589 (void) snprintf(di->errbuf, sizeof (di->errbuf), 590 dgettext(TEXT_DOMAIN, 591 "Unable to determine which snapshots to compare")); 592 593 atptrf = strchr(fromsnap, '@'); 594 atptrt = strchr(tosnap, '@'); 595 fdslen = atptrf ? atptrf - fromsnap : strlen(fromsnap); 596 tdslen = atptrt ? atptrt - tosnap : strlen(tosnap); 597 fsnlen = strlen(fromsnap) - fdslen; /* includes @ sign */ 598 tsnlen = strlen(tosnap) - tdslen; /* includes @ sign */ 599 600 if (fsnlen <= 1 || tsnlen == 1 || (fdslen == 0 && tdslen == 0) || 601 (fsnlen == 0 && tsnlen == 0)) { 602 return (zfs_error(hdl, EZFS_INVALIDNAME, di->errbuf)); 603 } else if ((fdslen > 0 && tdslen > 0) && 604 ((tdslen != fdslen || strncmp(fromsnap, tosnap, fdslen) != 0))) { 605 /* 606 * not the same dataset name, might be okay if 607 * tosnap is a clone of a fromsnap descendant. 608 */ 609 char origin[ZFS_MAXNAMELEN]; 610 zprop_source_t src; 611 zfs_handle_t *zhp; 612 613 di->ds = zfs_alloc(di->zhp->zfs_hdl, tdslen + 1); 614 (void) strncpy(di->ds, tosnap, tdslen); 615 di->ds[tdslen] = '\0'; 616 617 zhp = zfs_open(hdl, di->ds, ZFS_TYPE_FILESYSTEM); 618 while (zhp != NULL) { 619 (void) zfs_prop_get(zhp, ZFS_PROP_ORIGIN, 620 origin, sizeof (origin), &src, NULL, 0, B_FALSE); 621 622 if (strncmp(origin, fromsnap, fsnlen) == 0) 623 break; 624 625 (void) zfs_close(zhp); 626 zhp = zfs_open(hdl, origin, ZFS_TYPE_FILESYSTEM); 627 } 628 629 if (zhp == NULL) { 630 (void) snprintf(di->errbuf, sizeof (di->errbuf), 631 dgettext(TEXT_DOMAIN, 632 "Not an earlier snapshot from the same fs")); 633 return (zfs_error(hdl, EZFS_INVALIDNAME, di->errbuf)); 634 } else { 635 (void) zfs_close(zhp); 636 } 637 638 di->isclone = B_TRUE; 639 di->fromsnap = zfs_strdup(hdl, fromsnap); 640 if (tsnlen) { 641 di->tosnap = zfs_strdup(hdl, tosnap); 642 } else { 643 return (make_temp_snapshot(di)); 644 } 645 } else { 646 int dslen = fdslen ? fdslen : tdslen; 647 648 di->ds = zfs_alloc(hdl, dslen + 1); 649 (void) strncpy(di->ds, fdslen ? fromsnap : tosnap, dslen); 650 di->ds[dslen] = '\0'; 651 652 di->fromsnap = zfs_asprintf(hdl, "%s%s", di->ds, atptrf); 653 if (tsnlen) { 654 di->tosnap = zfs_asprintf(hdl, "%s%s", di->ds, atptrt); 655 } else { 656 return (make_temp_snapshot(di)); 657 } 658 } 659 return (0); 660 } 661 662 static int 663 get_mountpoint(differ_info_t *di, char *dsnm, char **mntpt) 664 { 665 boolean_t mounted; 666 667 mounted = is_mounted(di->zhp->zfs_hdl, dsnm, mntpt); 668 if (mounted == B_FALSE) { 669 (void) snprintf(di->errbuf, sizeof (di->errbuf), 670 dgettext(TEXT_DOMAIN, 671 "Cannot diff an unmounted snapshot")); 672 return (zfs_error(di->zhp->zfs_hdl, EZFS_BADTYPE, di->errbuf)); 673 } 674 675 /* Avoid a double slash at the beginning of root-mounted datasets */ 676 if (**mntpt == '/' && *(*mntpt + 1) == '\0') 677 **mntpt = '\0'; 678 return (0); 679 } 680 681 static int 682 get_mountpoints(differ_info_t *di) 683 { 684 char *strptr; 685 char *frommntpt; 686 687 /* 688 * first get the mountpoint for the parent dataset 689 */ 690 if (get_mountpoint(di, di->ds, &di->dsmnt) != 0) 691 return (-1); 692 693 strptr = strchr(di->tosnap, '@'); 694 ASSERT3P(strptr, !=, NULL); 695 di->tomnt = zfs_asprintf(di->zhp->zfs_hdl, "%s%s%s", di->dsmnt, 696 ZDIFF_SNAPDIR, ++strptr); 697 698 strptr = strchr(di->fromsnap, '@'); 699 ASSERT3P(strptr, !=, NULL); 700 701 frommntpt = di->dsmnt; 702 if (di->isclone) { 703 char *mntpt; 704 int err; 705 706 *strptr = '\0'; 707 err = get_mountpoint(di, di->fromsnap, &mntpt); 708 *strptr = '@'; 709 if (err != 0) 710 return (-1); 711 frommntpt = mntpt; 712 } 713 714 di->frommnt = zfs_asprintf(di->zhp->zfs_hdl, "%s%s%s", frommntpt, 715 ZDIFF_SNAPDIR, ++strptr); 716 717 if (di->isclone) 718 free(frommntpt); 719 720 return (0); 721 } 722 723 static int 724 setup_differ_info(zfs_handle_t *zhp, const char *fromsnap, 725 const char *tosnap, differ_info_t *di) 726 { 727 di->zhp = zhp; 728 729 di->cleanupfd = open(ZFS_DEV, O_RDWR|O_EXCL); 730 VERIFY(di->cleanupfd >= 0); 731 732 if (get_snapshot_names(di, fromsnap, tosnap) != 0) 733 return (-1); 734 735 if (get_mountpoints(di) != 0) 736 return (-1); 737 738 if (find_shares_object(di) != 0) 739 return (-1); 740 741 return (0); 742 } 743 744 int 745 zfs_show_diffs(zfs_handle_t *zhp, int outfd, const char *fromsnap, 746 const char *tosnap, int flags) 747 { 748 zfs_cmd_t zc = { 0 }; 749 char errbuf[1024]; 750 differ_info_t di = { 0 }; 751 pthread_t tid; 752 int pipefd[2]; 753 int iocerr; 754 755 (void) snprintf(errbuf, sizeof (errbuf), 756 dgettext(TEXT_DOMAIN, "zfs diff failed")); 757 758 if (setup_differ_info(zhp, fromsnap, tosnap, &di)) { 759 teardown_differ_info(&di); 760 return (-1); 761 } 762 763 if (pipe(pipefd)) { 764 zfs_error_aux(zhp->zfs_hdl, strerror(errno)); 765 teardown_differ_info(&di); 766 return (zfs_error(zhp->zfs_hdl, EZFS_PIPEFAILED, errbuf)); 767 } 768 769 di.scripted = (flags & ZFS_DIFF_PARSEABLE); 770 di.classify = (flags & ZFS_DIFF_CLASSIFY); 771 di.timestamped = (flags & ZFS_DIFF_TIMESTAMP); 772 773 di.outputfd = outfd; 774 di.datafd = pipefd[0]; 775 776 if (pthread_create(&tid, NULL, differ, &di)) { 777 zfs_error_aux(zhp->zfs_hdl, strerror(errno)); 778 (void) close(pipefd[0]); 779 (void) close(pipefd[1]); 780 teardown_differ_info(&di); 781 return (zfs_error(zhp->zfs_hdl, 782 EZFS_THREADCREATEFAILED, errbuf)); 783 } 784 785 /* do the ioctl() */ 786 (void) strlcpy(zc.zc_value, di.fromsnap, strlen(di.fromsnap) + 1); 787 (void) strlcpy(zc.zc_name, di.tosnap, strlen(di.tosnap) + 1); 788 zc.zc_cookie = pipefd[1]; 789 790 iocerr = ioctl(zhp->zfs_hdl->libzfs_fd, ZFS_IOC_DIFF, &zc); 791 if (iocerr != 0) { 792 (void) snprintf(errbuf, sizeof (errbuf), 793 dgettext(TEXT_DOMAIN, "Unable to obtain diffs")); 794 if (errno == EPERM) { 795 zfs_error_aux(zhp->zfs_hdl, dgettext(TEXT_DOMAIN, 796 "\n The sys_mount privilege or diff delegated " 797 "permission is needed\n to execute the " 798 "diff ioctl")); 799 } else if (errno == EXDEV) { 800 zfs_error_aux(zhp->zfs_hdl, dgettext(TEXT_DOMAIN, 801 "\n Not an earlier snapshot from the same fs")); 802 } else if (errno != EPIPE || di.zerr == 0) { 803 zfs_error_aux(zhp->zfs_hdl, strerror(errno)); 804 } 805 (void) close(pipefd[1]); 806 (void) pthread_cancel(tid); 807 (void) pthread_join(tid, NULL); 808 teardown_differ_info(&di); 809 if (di.zerr != 0 && di.zerr != EPIPE) { 810 zfs_error_aux(zhp->zfs_hdl, strerror(di.zerr)); 811 return (zfs_error(zhp->zfs_hdl, EZFS_DIFF, di.errbuf)); 812 } else { 813 return (zfs_error(zhp->zfs_hdl, EZFS_DIFFDATA, errbuf)); 814 } 815 } 816 817 (void) close(pipefd[1]); 818 (void) pthread_join(tid, NULL); 819 820 if (di.zerr != 0) { 821 zfs_error_aux(zhp->zfs_hdl, strerror(di.zerr)); 822 return (zfs_error(zhp->zfs_hdl, EZFS_DIFF, di.errbuf)); 823 } 824 teardown_differ_info(&di); 825 return (0); 826 } 827