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 <stddef.h> 37#include <unistd.h> 38#include <stdio.h> 39#include <stdlib.h> 40#include <pthread.h> 41#include <sys/zfs_ioctl.h> 42#include <libzfs.h> 43#include "libzfs_impl.h" 44 45#define ZDIFF_SNAPDIR "/.zfs/snapshot/" 46#define ZDIFF_SHARESDIR "/.zfs/shares/" 47#define ZDIFF_PREFIX "zfs-diff-%d" 48 49#define ZDIFF_ADDED '+' 50#define ZDIFF_MODIFIED 'M' 51#define ZDIFF_REMOVED '-' 52#define ZDIFF_RENAMED 'R' 53 54static boolean_t 55do_name_cmp(const char *fpath, const char *tpath) 56{ 57 char *fname, *tname; 58 fname = strrchr(fpath, '/') + 1; 59 tname = strrchr(tpath, '/') + 1; 60 return (strcmp(fname, tname) == 0); 61} 62 63typedef struct differ_info { 64 zfs_handle_t *zhp; 65 char *fromsnap; 66 char *frommnt; 67 char *tosnap; 68 char *tomnt; 69 char *ds; 70 char *dsmnt; 71 char *tmpsnap; 72 char errbuf[1024]; 73 boolean_t isclone; 74 boolean_t scripted; 75 boolean_t classify; 76 boolean_t timestamped; 77 uint64_t shares; 78 int zerr; 79 int cleanupfd; 80 int outputfd; 81 int datafd; 82} differ_info_t; 83 84/* 85 * Given a {dsname, object id}, get the object path 86 */ 87static int 88get_stats_for_obj(differ_info_t *di, const char *dsname, uint64_t obj, 89 char *pn, int maxlen, zfs_stat_t *sb) 90{ 91 zfs_cmd_t zc = { 0 }; 92 int error; 93 94 (void) strlcpy(zc.zc_name, dsname, sizeof (zc.zc_name)); 95 zc.zc_obj = obj; 96 97 errno = 0; 98 error = ioctl(di->zhp->zfs_hdl->libzfs_fd, ZFS_IOC_OBJ_TO_STATS, &zc); 99 di->zerr = errno; 100 101 /* we can get stats even if we failed to get a path */ 102 (void) memcpy(sb, &zc.zc_stat, sizeof (zfs_stat_t)); 103 if (error == 0) { 104 ASSERT(di->zerr == 0); 105 (void) strlcpy(pn, zc.zc_value, maxlen); 106 return (0); 107 } 108 109 if (di->zerr == EPERM) { 110 (void) snprintf(di->errbuf, sizeof (di->errbuf), 111 dgettext(TEXT_DOMAIN, 112 "The sys_config privilege or diff delegated permission " 113 "is needed\nto discover path names")); 114 return (-1); 115 } else { 116 (void) snprintf(di->errbuf, sizeof (di->errbuf), 117 dgettext(TEXT_DOMAIN, 118 "Unable to determine path or stats for " 119 "object %lld in %s"), obj, dsname); 120 return (-1); 121 } 122} 123 124/* 125 * stream_bytes 126 * 127 * Prints a file name out a character at a time. If the character is 128 * not in the range of what we consider "printable" ASCII, display it 129 * as an escaped 3-digit octal value. ASCII values less than a space 130 * are all control characters and we declare the upper end as the 131 * DELete character. This also is the last 7-bit ASCII character. 132 * We choose to treat all 8-bit ASCII as not printable for this 133 * application. 134 */ 135static void 136stream_bytes(FILE *fp, const char *string) 137{ 138 while (*string) { 139 if (*string > ' ' && *string != '\\' && *string < '\177') 140 (void) fprintf(fp, "%c", *string++); 141 else { 142 (void) fprintf(fp, "\\%03hho", 143 (unsigned char)*string++); 144 } 145 } 146} 147 148static void 149print_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#ifdef S_IFDOOR 164 case S_IFDOOR: 165 symbol = '>'; 166 break; 167#endif 168 case S_IFIFO: 169 symbol = '|'; 170 break; 171 case S_IFLNK: 172 symbol = '@'; 173 break; 174#ifdef S_IFPORT 175 case S_IFPORT: 176 symbol = 'P'; 177 break; 178#endif 179 case S_IFSOCK: 180 symbol = '='; 181 break; 182 case S_IFREG: 183 symbol = 'F'; 184 break; 185 default: 186 symbol = '?'; 187 break; 188 } 189 (void) fprintf(fp, "%c", symbol); 190} 191 192static void 193print_cmn(FILE *fp, differ_info_t *di, const char *file) 194{ 195 stream_bytes(fp, di->dsmnt); 196 stream_bytes(fp, file); 197} 198 199static void 200print_rename(FILE *fp, differ_info_t *di, const char *old, const char *new, 201 zfs_stat_t *isb) 202{ 203 if (di->timestamped) 204 (void) fprintf(fp, "%10lld.%09lld\t", 205 (longlong_t)isb->zs_ctime[0], 206 (longlong_t)isb->zs_ctime[1]); 207 (void) fprintf(fp, "%c\t", ZDIFF_RENAMED); 208 if (di->classify) { 209 print_what(fp, isb->zs_mode); 210 (void) fprintf(fp, "\t"); 211 } 212 print_cmn(fp, di, old); 213 if (di->scripted) 214 (void) fprintf(fp, "\t"); 215 else 216 (void) fprintf(fp, " -> "); 217 print_cmn(fp, di, new); 218 (void) fprintf(fp, "\n"); 219} 220 221static void 222print_link_change(FILE *fp, differ_info_t *di, int delta, const char *file, 223 zfs_stat_t *isb) 224{ 225 if (di->timestamped) 226 (void) fprintf(fp, "%10lld.%09lld\t", 227 (longlong_t)isb->zs_ctime[0], 228 (longlong_t)isb->zs_ctime[1]); 229 (void) fprintf(fp, "%c\t", ZDIFF_MODIFIED); 230 if (di->classify) { 231 print_what(fp, isb->zs_mode); 232 (void) fprintf(fp, "\t"); 233 } 234 print_cmn(fp, di, file); 235 (void) fprintf(fp, "\t(%+d)", delta); 236 (void) fprintf(fp, "\n"); 237} 238 239static void 240print_file(FILE *fp, differ_info_t *di, char type, const char *file, 241 zfs_stat_t *isb) 242{ 243 if (di->timestamped) 244 (void) fprintf(fp, "%10lld.%09lld\t", 245 (longlong_t)isb->zs_ctime[0], 246 (longlong_t)isb->zs_ctime[1]); 247 (void) fprintf(fp, "%c\t", type); 248 if (di->classify) { 249 print_what(fp, isb->zs_mode); 250 (void) fprintf(fp, "\t"); 251 } 252 print_cmn(fp, di, file); 253 (void) fprintf(fp, "\n"); 254} 255 256static int 257write_inuse_diffs_one(FILE *fp, differ_info_t *di, uint64_t dobj) 258{ 259 struct zfs_stat fsb, tsb; 260 boolean_t same_name; 261 mode_t fmode, tmode; 262 char fobjname[MAXPATHLEN], tobjname[MAXPATHLEN]; 263 int fobjerr, tobjerr; 264 int change; 265 266 if (dobj == di->shares) 267 return (0); 268 269 /* 270 * Check the from and to snapshots for info on the object. If 271 * we get ENOENT, then the object just didn't exist in that 272 * snapshot. If we get ENOTSUP, then we tried to get 273 * info on a non-ZPL object, which we don't care about anyway. 274 */ 275 fobjerr = get_stats_for_obj(di, di->fromsnap, dobj, fobjname, 276 MAXPATHLEN, &fsb); 277 if (fobjerr && di->zerr != ENOENT && di->zerr != ENOTSUP) 278 return (-1); 279 280 tobjerr = get_stats_for_obj(di, di->tosnap, dobj, tobjname, 281 MAXPATHLEN, &tsb); 282 if (tobjerr && di->zerr != ENOENT && di->zerr != ENOTSUP) 283 return (-1); 284 285 /* 286 * Unallocated object sharing the same meta dnode block 287 */ 288 if (fobjerr && tobjerr) { 289 ASSERT(di->zerr == ENOENT || di->zerr == ENOTSUP); 290 di->zerr = 0; 291 return (0); 292 } 293 294 di->zerr = 0; /* negate get_stats_for_obj() from side that failed */ 295 fmode = fsb.zs_mode & S_IFMT; 296 tmode = tsb.zs_mode & S_IFMT; 297 if (fmode == S_IFDIR || tmode == S_IFDIR || fsb.zs_links == 0 || 298 tsb.zs_links == 0) 299 change = 0; 300 else 301 change = tsb.zs_links - fsb.zs_links; 302 303 if (fobjerr) { 304 if (change) { 305 print_link_change(fp, di, change, tobjname, &tsb); 306 return (0); 307 } 308 print_file(fp, di, ZDIFF_ADDED, tobjname, &tsb); 309 return (0); 310 } else if (tobjerr) { 311 if (change) { 312 print_link_change(fp, di, change, fobjname, &fsb); 313 return (0); 314 } 315 print_file(fp, di, ZDIFF_REMOVED, fobjname, &fsb); 316 return (0); 317 } 318 319 if (fmode != tmode && fsb.zs_gen == tsb.zs_gen) 320 tsb.zs_gen++; /* Force a generational difference */ 321 same_name = do_name_cmp(fobjname, tobjname); 322 323 /* Simple modification or no change */ 324 if (fsb.zs_gen == tsb.zs_gen) { 325 /* No apparent changes. Could we assert !this? */ 326 if (fsb.zs_ctime[0] == tsb.zs_ctime[0] && 327 fsb.zs_ctime[1] == tsb.zs_ctime[1]) 328 return (0); 329 if (change) { 330 print_link_change(fp, di, change, 331 change > 0 ? fobjname : tobjname, &tsb); 332 } else if (same_name) { 333 print_file(fp, di, ZDIFF_MODIFIED, fobjname, &tsb); 334 } else { 335 print_rename(fp, di, fobjname, tobjname, &tsb); 336 } 337 return (0); 338 } else { 339 /* file re-created or object re-used */ 340 print_file(fp, di, ZDIFF_REMOVED, fobjname, &fsb); 341 print_file(fp, di, ZDIFF_ADDED, tobjname, &tsb); 342 return (0); 343 } 344} 345 346static int 347write_inuse_diffs(FILE *fp, differ_info_t *di, dmu_diff_record_t *dr) 348{ 349 uint64_t o; 350 int err; 351 352 for (o = dr->ddr_first; o <= dr->ddr_last; o++) { 353 if (err = write_inuse_diffs_one(fp, di, o)) 354 return (err); 355 } 356 return (0); 357} 358 359static int 360describe_free(FILE *fp, differ_info_t *di, uint64_t object, char *namebuf, 361 int maxlen) 362{ 363 struct zfs_stat sb; 364 365 if (get_stats_for_obj(di, di->fromsnap, object, namebuf, 366 maxlen, &sb) != 0) { 367 /* Let it slide, if in the delete queue on from side */ 368 if (di->zerr == ENOENT && sb.zs_links == 0) { 369 di->zerr = 0; 370 return (0); 371 } 372 return (-1); 373 } 374 375 print_file(fp, di, ZDIFF_REMOVED, namebuf, &sb); 376 return (0); 377} 378 379static int 380write_free_diffs(FILE *fp, differ_info_t *di, dmu_diff_record_t *dr) 381{ 382 zfs_cmd_t zc = { 0 }; 383 libzfs_handle_t *lhdl = di->zhp->zfs_hdl; 384 char fobjname[MAXPATHLEN]; 385 386 (void) strlcpy(zc.zc_name, di->fromsnap, sizeof (zc.zc_name)); 387 zc.zc_obj = dr->ddr_first - 1; 388 389 ASSERT(di->zerr == 0); 390 391 while (zc.zc_obj < dr->ddr_last) { 392 int err; 393 394 err = ioctl(lhdl->libzfs_fd, ZFS_IOC_NEXT_OBJ, &zc); 395 if (err == 0) { 396 if (zc.zc_obj == di->shares) { 397 zc.zc_obj++; 398 continue; 399 } 400 if (zc.zc_obj > dr->ddr_last) { 401 break; 402 } 403 err = describe_free(fp, di, zc.zc_obj, fobjname, 404 MAXPATHLEN); 405 if (err) 406 break; 407 } else if (errno == ESRCH) { 408 break; 409 } else { 410 (void) snprintf(di->errbuf, sizeof (di->errbuf), 411 dgettext(TEXT_DOMAIN, 412 "next allocated object (> %lld) find failure"), 413 zc.zc_obj); 414 di->zerr = errno; 415 break; 416 } 417 } 418 if (di->zerr) 419 return (-1); 420 return (0); 421} 422 423static void * 424differ(void *arg) 425{ 426 differ_info_t *di = arg; 427 dmu_diff_record_t dr; 428 FILE *ofp; 429 int err = 0; 430 431 if ((ofp = fdopen(di->outputfd, "w")) == NULL) { 432 di->zerr = errno; 433 (void) strerror_r(errno, di->errbuf, sizeof (di->errbuf)); 434 (void) close(di->datafd); 435 return ((void *)-1); 436 } 437 438 for (;;) { 439 char *cp = (char *)&dr; 440 int len = sizeof (dr); 441 int rv; 442 443 do { 444 rv = read(di->datafd, cp, len); 445 cp += rv; 446 len -= rv; 447 } while (len > 0 && rv > 0); 448 449 if (rv < 0 || (rv == 0 && len != sizeof (dr))) { 450 di->zerr = EPIPE; 451 break; 452 } else if (rv == 0) { 453 /* end of file at a natural breaking point */ 454 break; 455 } 456 457 switch (dr.ddr_type) { 458 case DDR_FREE: 459 err = write_free_diffs(ofp, di, &dr); 460 break; 461 case DDR_INUSE: 462 err = write_inuse_diffs(ofp, di, &dr); 463 break; 464 default: 465 di->zerr = EPIPE; 466 break; 467 } 468 469 if (err || di->zerr) 470 break; 471 } 472 473 (void) fclose(ofp); 474 (void) close(di->datafd); 475 if (err) 476 return ((void *)-1); 477 if (di->zerr) { 478 ASSERT(di->zerr == EINVAL); 479 (void) snprintf(di->errbuf, sizeof (di->errbuf), 480 dgettext(TEXT_DOMAIN, 481 "Internal error: bad data from diff IOCTL")); 482 return ((void *)-1); 483 } 484 return ((void *)0); 485} 486 487static int 488find_shares_object(differ_info_t *di) 489{ 490 char fullpath[MAXPATHLEN]; 491 struct stat64 sb = { 0 }; 492 493 (void) strlcpy(fullpath, di->dsmnt, MAXPATHLEN); 494 (void) strlcat(fullpath, ZDIFF_SHARESDIR, MAXPATHLEN); 495 496 if (stat64(fullpath, &sb) != 0) { 497#ifdef sun 498 (void) snprintf(di->errbuf, sizeof (di->errbuf), 499 dgettext(TEXT_DOMAIN, "Cannot stat %s"), fullpath); 500 return (zfs_error(di->zhp->zfs_hdl, EZFS_DIFF, di->errbuf)); 501#else 502 return (0); 503#endif 504 } 505 506 di->shares = (uint64_t)sb.st_ino; 507 return (0); 508} 509 510static int 511make_temp_snapshot(differ_info_t *di) 512{ 513 libzfs_handle_t *hdl = di->zhp->zfs_hdl; 514 zfs_cmd_t zc = { 0 }; 515 516 (void) snprintf(zc.zc_value, sizeof (zc.zc_value), 517 ZDIFF_PREFIX, getpid()); 518 (void) strlcpy(zc.zc_name, di->ds, sizeof (zc.zc_name)); 519 zc.zc_cleanup_fd = di->cleanupfd; 520 521 if (ioctl(hdl->libzfs_fd, ZFS_IOC_TMP_SNAPSHOT, &zc) != 0) { 522 int err = errno; 523 if (err == EPERM) { 524 (void) snprintf(di->errbuf, sizeof (di->errbuf), 525 dgettext(TEXT_DOMAIN, "The diff delegated " 526 "permission is needed in order\nto create a " 527 "just-in-time snapshot for diffing\n")); 528 return (zfs_error(hdl, EZFS_DIFF, di->errbuf)); 529 } else { 530 (void) snprintf(di->errbuf, sizeof (di->errbuf), 531 dgettext(TEXT_DOMAIN, "Cannot create just-in-time " 532 "snapshot of '%s'"), zc.zc_name); 533 return (zfs_standard_error(hdl, err, di->errbuf)); 534 } 535 } 536 537 di->tmpsnap = zfs_strdup(hdl, zc.zc_value); 538 di->tosnap = zfs_asprintf(hdl, "%s@%s", di->ds, di->tmpsnap); 539 return (0); 540} 541 542static void 543teardown_differ_info(differ_info_t *di) 544{ 545 free(di->ds); 546 free(di->dsmnt); 547 free(di->fromsnap); 548 free(di->frommnt); 549 free(di->tosnap); 550 free(di->tmpsnap); 551 free(di->tomnt); 552 (void) close(di->cleanupfd); 553} 554 555static int 556get_snapshot_names(differ_info_t *di, const char *fromsnap, 557 const char *tosnap) 558{ 559 libzfs_handle_t *hdl = di->zhp->zfs_hdl; 560 char *atptrf = NULL; 561 char *atptrt = NULL; 562 int fdslen, fsnlen; 563 int tdslen, tsnlen; 564 565 /* 566 * Can accept 567 * dataset@snap1 568 * dataset@snap1 dataset@snap2 569 * dataset@snap1 @snap2 570 * dataset@snap1 dataset 571 * @snap1 dataset@snap2 572 */ 573 if (tosnap == NULL) { 574 /* only a from snapshot given, must be valid */ 575 (void) snprintf(di->errbuf, sizeof (di->errbuf), 576 dgettext(TEXT_DOMAIN, 577 "Badly formed snapshot name %s"), fromsnap); 578 579 if (!zfs_validate_name(hdl, fromsnap, ZFS_TYPE_SNAPSHOT, 580 B_FALSE)) { 581 return (zfs_error(hdl, EZFS_INVALIDNAME, 582 di->errbuf)); 583 } 584 585 atptrf = strchr(fromsnap, '@'); 586 ASSERT(atptrf != NULL); 587 fdslen = atptrf - fromsnap; 588 589 di->fromsnap = zfs_strdup(hdl, fromsnap); 590 di->ds = zfs_strdup(hdl, fromsnap); 591 di->ds[fdslen] = '\0'; 592 593 /* the to snap will be a just-in-time snap of the head */ 594 return (make_temp_snapshot(di)); 595 } 596 597 (void) snprintf(di->errbuf, sizeof (di->errbuf), 598 dgettext(TEXT_DOMAIN, 599 "Unable to determine which snapshots to compare")); 600 601 atptrf = strchr(fromsnap, '@'); 602 atptrt = strchr(tosnap, '@'); 603 fdslen = atptrf ? atptrf - fromsnap : strlen(fromsnap); 604 tdslen = atptrt ? atptrt - tosnap : strlen(tosnap); 605 fsnlen = strlen(fromsnap) - fdslen; /* includes @ sign */ 606 tsnlen = strlen(tosnap) - tdslen; /* includes @ sign */ 607 608 if (fsnlen <= 1 || tsnlen == 1 || (fdslen == 0 && tdslen == 0) || 609 (fsnlen == 0 && tsnlen == 0)) { 610 return (zfs_error(hdl, EZFS_INVALIDNAME, di->errbuf)); 611 } else if ((fdslen > 0 && tdslen > 0) && 612 ((tdslen != fdslen || strncmp(fromsnap, tosnap, fdslen) != 0))) { 613 /* 614 * not the same dataset name, might be okay if 615 * tosnap is a clone of a fromsnap descendant. 616 */ 617 char origin[ZFS_MAXNAMELEN]; 618 zprop_source_t src; 619 zfs_handle_t *zhp; 620 621 di->ds = zfs_alloc(di->zhp->zfs_hdl, tdslen + 1); 622 (void) strncpy(di->ds, tosnap, tdslen); 623 di->ds[tdslen] = '\0'; 624 625 zhp = zfs_open(hdl, di->ds, ZFS_TYPE_FILESYSTEM); 626 while (zhp != NULL) { 627 (void) zfs_prop_get(zhp, ZFS_PROP_ORIGIN, 628 origin, sizeof (origin), &src, NULL, 0, B_FALSE); 629 630 if (strncmp(origin, fromsnap, fsnlen) == 0) 631 break; 632 633 (void) zfs_close(zhp); 634 zhp = zfs_open(hdl, origin, ZFS_TYPE_FILESYSTEM); 635 } 636 637 if (zhp == NULL) { 638 (void) snprintf(di->errbuf, sizeof (di->errbuf), 639 dgettext(TEXT_DOMAIN, 640 "Not an earlier snapshot from the same fs")); 641 return (zfs_error(hdl, EZFS_INVALIDNAME, di->errbuf)); 642 } else { 643 (void) zfs_close(zhp); 644 } 645 646 di->isclone = B_TRUE; 647 di->fromsnap = zfs_strdup(hdl, fromsnap); 648 if (tsnlen) { 649 di->tosnap = zfs_strdup(hdl, tosnap); 650 } else { 651 return (make_temp_snapshot(di)); 652 } 653 } else { 654 int dslen = fdslen ? fdslen : tdslen; 655 656 di->ds = zfs_alloc(hdl, dslen + 1); 657 (void) strncpy(di->ds, fdslen ? fromsnap : tosnap, dslen); 658 di->ds[dslen] = '\0'; 659 660 di->fromsnap = zfs_asprintf(hdl, "%s%s", di->ds, atptrf); 661 if (tsnlen) { 662 di->tosnap = zfs_asprintf(hdl, "%s%s", di->ds, atptrt); 663 } else { 664 return (make_temp_snapshot(di)); 665 } 666 } 667 return (0); 668} 669 670static int 671get_mountpoint(differ_info_t *di, char *dsnm, char **mntpt) 672{ 673 boolean_t mounted; 674 675 mounted = is_mounted(di->zhp->zfs_hdl, dsnm, mntpt); 676 if (mounted == B_FALSE) { 677 (void) snprintf(di->errbuf, sizeof (di->errbuf), 678 dgettext(TEXT_DOMAIN, 679 "Cannot diff an unmounted snapshot")); 680 return (zfs_error(di->zhp->zfs_hdl, EZFS_BADTYPE, di->errbuf)); 681 } 682 683 /* Avoid a double slash at the beginning of root-mounted datasets */ 684 if (**mntpt == '/' && *(*mntpt + 1) == '\0') 685 **mntpt = '\0'; 686 return (0); 687} 688 689static int 690get_mountpoints(differ_info_t *di) 691{ 692 char *strptr; 693 char *frommntpt; 694 695 /* 696 * first get the mountpoint for the parent dataset 697 */ 698 if (get_mountpoint(di, di->ds, &di->dsmnt) != 0) 699 return (-1); 700 701 strptr = strchr(di->tosnap, '@'); 702 ASSERT3P(strptr, !=, NULL); 703 di->tomnt = zfs_asprintf(di->zhp->zfs_hdl, "%s%s%s", di->dsmnt, 704 ZDIFF_SNAPDIR, ++strptr); 705 706 strptr = strchr(di->fromsnap, '@'); 707 ASSERT3P(strptr, !=, NULL); 708 709 frommntpt = di->dsmnt; 710 if (di->isclone) { 711 char *mntpt; 712 int err; 713 714 *strptr = '\0'; 715 err = get_mountpoint(di, di->fromsnap, &mntpt); 716 *strptr = '@'; 717 if (err != 0) 718 return (-1); 719 frommntpt = mntpt; 720 } 721 722 di->frommnt = zfs_asprintf(di->zhp->zfs_hdl, "%s%s%s", frommntpt, 723 ZDIFF_SNAPDIR, ++strptr); 724 725 if (di->isclone) 726 free(frommntpt); 727 728 return (0); 729} 730 731static int 732setup_differ_info(zfs_handle_t *zhp, const char *fromsnap, 733 const char *tosnap, differ_info_t *di) 734{ 735 di->zhp = zhp; 736 737 di->cleanupfd = open(ZFS_DEV, O_RDWR|O_EXCL); 738 VERIFY(di->cleanupfd >= 0); 739 740 if (get_snapshot_names(di, fromsnap, tosnap) != 0) 741 return (-1); 742 743 if (get_mountpoints(di) != 0) 744 return (-1); 745 746 if (find_shares_object(di) != 0) 747 return (-1); 748 749 return (0); 750} 751 752int 753zfs_show_diffs(zfs_handle_t *zhp, int outfd, const char *fromsnap, 754 const char *tosnap, int flags) 755{ 756 zfs_cmd_t zc = { 0 }; 757 char errbuf[1024]; 758 differ_info_t di = { 0 }; 759 pthread_t tid; 760 int pipefd[2]; 761 int iocerr; 762 763 (void) snprintf(errbuf, sizeof (errbuf), 764 dgettext(TEXT_DOMAIN, "zfs diff failed")); 765 766 if (setup_differ_info(zhp, fromsnap, tosnap, &di)) { 767 teardown_differ_info(&di); 768 return (-1); 769 } 770 771 if (pipe(pipefd)) { 772 zfs_error_aux(zhp->zfs_hdl, strerror(errno)); 773 teardown_differ_info(&di); 774 return (zfs_error(zhp->zfs_hdl, EZFS_PIPEFAILED, errbuf)); 775 } 776 777 di.scripted = (flags & ZFS_DIFF_PARSEABLE); 778 di.classify = (flags & ZFS_DIFF_CLASSIFY); 779 di.timestamped = (flags & ZFS_DIFF_TIMESTAMP); 780 781 di.outputfd = outfd; 782 di.datafd = pipefd[0]; 783 784 if (pthread_create(&tid, NULL, differ, &di)) { 785 zfs_error_aux(zhp->zfs_hdl, strerror(errno)); 786 (void) close(pipefd[0]); 787 (void) close(pipefd[1]); 788 teardown_differ_info(&di); 789 return (zfs_error(zhp->zfs_hdl, 790 EZFS_THREADCREATEFAILED, errbuf)); 791 } 792 793 /* do the ioctl() */ 794 (void) strlcpy(zc.zc_value, di.fromsnap, strlen(di.fromsnap) + 1); 795 (void) strlcpy(zc.zc_name, di.tosnap, strlen(di.tosnap) + 1); 796 zc.zc_cookie = pipefd[1]; 797 798 iocerr = ioctl(zhp->zfs_hdl->libzfs_fd, ZFS_IOC_DIFF, &zc); 799 if (iocerr != 0) { 800 (void) snprintf(errbuf, sizeof (errbuf), 801 dgettext(TEXT_DOMAIN, "Unable to obtain diffs")); 802 if (errno == EPERM) { 803 zfs_error_aux(zhp->zfs_hdl, dgettext(TEXT_DOMAIN, 804 "\n The sys_mount privilege or diff delegated " 805 "permission is needed\n to execute the " 806 "diff ioctl")); 807 } else if (errno == EXDEV) { 808 zfs_error_aux(zhp->zfs_hdl, dgettext(TEXT_DOMAIN, 809 "\n Not an earlier snapshot from the same fs")); 810 } else if (errno != EPIPE || di.zerr == 0) { 811 zfs_error_aux(zhp->zfs_hdl, strerror(errno)); 812 } 813 (void) close(pipefd[1]); 814 (void) pthread_cancel(tid); 815 (void) pthread_join(tid, NULL); 816 teardown_differ_info(&di); 817 if (di.zerr != 0 && di.zerr != EPIPE) { 818 zfs_error_aux(zhp->zfs_hdl, strerror(di.zerr)); 819 return (zfs_error(zhp->zfs_hdl, EZFS_DIFF, di.errbuf)); 820 } else { 821 return (zfs_error(zhp->zfs_hdl, EZFS_DIFFDATA, errbuf)); 822 } 823 } 824 825 (void) close(pipefd[1]); 826 (void) pthread_join(tid, NULL); 827 828 if (di.zerr != 0) { 829 zfs_error_aux(zhp->zfs_hdl, strerror(di.zerr)); 830 return (zfs_error(zhp->zfs_hdl, EZFS_DIFF, di.errbuf)); 831 } 832 teardown_differ_info(&di); 833 return (0); 834} 835