libzfs_diff.c revision 307122
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 <stddef.h> 41#include <unistd.h> 42#include <stdio.h> 43#include <stdlib.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 58static boolean_t 59do_name_cmp(const char *fpath, const char *tpath) 60{ 61 char *fname, *tname; 62 fname = strrchr(fpath, '/') + 1; 63 tname = strrchr(tpath, '/') + 1; 64 return (strcmp(fname, tname) == 0); 65} 66 67typedef struct differ_info { 68 zfs_handle_t *zhp; 69 char *fromsnap; 70 char *frommnt; 71 char *tosnap; 72 char *tomnt; 73 char *ds; 74 char *dsmnt; 75 char *tmpsnap; 76 char errbuf[1024]; 77 boolean_t isclone; 78 boolean_t scripted; 79 boolean_t classify; 80 boolean_t timestamped; 81 uint64_t shares; 82 int zerr; 83 int cleanupfd; 84 int outputfd; 85 int datafd; 86} differ_info_t; 87 88/* 89 * Given a {dsname, object id}, get the object path 90 */ 91static int 92get_stats_for_obj(differ_info_t *di, const char *dsname, uint64_t obj, 93 char *pn, int maxlen, zfs_stat_t *sb) 94{ 95 zfs_cmd_t zc = { 0 }; 96 int error; 97 98 (void) strlcpy(zc.zc_name, dsname, sizeof (zc.zc_name)); 99 zc.zc_obj = obj; 100 101 errno = 0; 102 error = ioctl(di->zhp->zfs_hdl->libzfs_fd, ZFS_IOC_OBJ_TO_STATS, &zc); 103 di->zerr = errno; 104 105 /* we can get stats even if we failed to get a path */ 106 (void) memcpy(sb, &zc.zc_stat, sizeof (zfs_stat_t)); 107 if (error == 0) { 108 ASSERT(di->zerr == 0); 109 (void) strlcpy(pn, zc.zc_value, maxlen); 110 return (0); 111 } 112 113 if (di->zerr == EPERM) { 114 (void) snprintf(di->errbuf, sizeof (di->errbuf), 115 dgettext(TEXT_DOMAIN, 116 "The sys_config privilege or diff delegated permission " 117 "is needed\nto discover path names")); 118 return (-1); 119 } else { 120 (void) snprintf(di->errbuf, sizeof (di->errbuf), 121 dgettext(TEXT_DOMAIN, 122 "Unable to determine path or stats for " 123 "object %lld in %s"), obj, dsname); 124 return (-1); 125 } 126} 127 128/* 129 * stream_bytes 130 * 131 * Prints a file name out a character at a time. If the character is 132 * not in the range of what we consider "printable" ASCII, display it 133 * as an escaped 3-digit octal value. ASCII values less than a space 134 * are all control characters and we declare the upper end as the 135 * DELete character. This also is the last 7-bit ASCII character. 136 * We choose to treat all 8-bit ASCII as not printable for this 137 * application. 138 */ 139static void 140stream_bytes(FILE *fp, const char *string) 141{ 142 char c; 143 144 while ((c = *string++) != '\0') { 145 if (c > ' ' && c != '\\' && c < '\177') { 146 (void) fprintf(fp, "%c", c); 147 } else { 148 (void) fprintf(fp, "\\%03o", (uint8_t)c); 149 } 150 } 151} 152 153static void 154print_what(FILE *fp, mode_t what) 155{ 156 char symbol; 157 158 switch (what & S_IFMT) { 159 case S_IFBLK: 160 symbol = 'B'; 161 break; 162 case S_IFCHR: 163 symbol = 'C'; 164 break; 165 case S_IFDIR: 166 symbol = '/'; 167 break; 168#ifdef S_IFDOOR 169 case S_IFDOOR: 170 symbol = '>'; 171 break; 172#endif 173 case S_IFIFO: 174 symbol = '|'; 175 break; 176 case S_IFLNK: 177 symbol = '@'; 178 break; 179#ifdef S_IFPORT 180 case S_IFPORT: 181 symbol = 'P'; 182 break; 183#endif 184 case S_IFSOCK: 185 symbol = '='; 186 break; 187 case S_IFREG: 188 symbol = 'F'; 189 break; 190 default: 191 symbol = '?'; 192 break; 193 } 194 (void) fprintf(fp, "%c", symbol); 195} 196 197static void 198print_cmn(FILE *fp, differ_info_t *di, const char *file) 199{ 200 stream_bytes(fp, di->dsmnt); 201 stream_bytes(fp, file); 202} 203 204static void 205print_rename(FILE *fp, differ_info_t *di, const char *old, const char *new, 206 zfs_stat_t *isb) 207{ 208 if (di->timestamped) 209 (void) fprintf(fp, "%10lld.%09lld\t", 210 (longlong_t)isb->zs_ctime[0], 211 (longlong_t)isb->zs_ctime[1]); 212 (void) fprintf(fp, "%c\t", ZDIFF_RENAMED); 213 if (di->classify) { 214 print_what(fp, isb->zs_mode); 215 (void) fprintf(fp, "\t"); 216 } 217 print_cmn(fp, di, old); 218 if (di->scripted) 219 (void) fprintf(fp, "\t"); 220 else 221 (void) fprintf(fp, " -> "); 222 print_cmn(fp, di, new); 223 (void) fprintf(fp, "\n"); 224} 225 226static void 227print_link_change(FILE *fp, differ_info_t *di, int delta, const char *file, 228 zfs_stat_t *isb) 229{ 230 if (di->timestamped) 231 (void) fprintf(fp, "%10lld.%09lld\t", 232 (longlong_t)isb->zs_ctime[0], 233 (longlong_t)isb->zs_ctime[1]); 234 (void) fprintf(fp, "%c\t", ZDIFF_MODIFIED); 235 if (di->classify) { 236 print_what(fp, isb->zs_mode); 237 (void) fprintf(fp, "\t"); 238 } 239 print_cmn(fp, di, file); 240 (void) fprintf(fp, "\t(%+d)", delta); 241 (void) fprintf(fp, "\n"); 242} 243 244static void 245print_file(FILE *fp, differ_info_t *di, char type, const char *file, 246 zfs_stat_t *isb) 247{ 248 if (di->timestamped) 249 (void) fprintf(fp, "%10lld.%09lld\t", 250 (longlong_t)isb->zs_ctime[0], 251 (longlong_t)isb->zs_ctime[1]); 252 (void) fprintf(fp, "%c\t", type); 253 if (di->classify) { 254 print_what(fp, isb->zs_mode); 255 (void) fprintf(fp, "\t"); 256 } 257 print_cmn(fp, di, file); 258 (void) fprintf(fp, "\n"); 259} 260 261static int 262write_inuse_diffs_one(FILE *fp, differ_info_t *di, uint64_t dobj) 263{ 264 struct zfs_stat fsb, tsb; 265 boolean_t same_name; 266 mode_t fmode, tmode; 267 char fobjname[MAXPATHLEN], tobjname[MAXPATHLEN]; 268 int fobjerr, tobjerr; 269 int change; 270 271 if (dobj == di->shares) 272 return (0); 273 274 /* 275 * Check the from and to snapshots for info on the object. If 276 * we get ENOENT, then the object just didn't exist in that 277 * snapshot. If we get ENOTSUP, then we tried to get 278 * info on a non-ZPL object, which we don't care about anyway. 279 */ 280 fobjerr = get_stats_for_obj(di, di->fromsnap, dobj, fobjname, 281 MAXPATHLEN, &fsb); 282 if (fobjerr && di->zerr != ENOENT && di->zerr != ENOTSUP) 283 return (-1); 284 285 tobjerr = get_stats_for_obj(di, di->tosnap, dobj, tobjname, 286 MAXPATHLEN, &tsb); 287 if (tobjerr && di->zerr != ENOENT && di->zerr != ENOTSUP) 288 return (-1); 289 290 /* 291 * Unallocated object sharing the same meta dnode block 292 */ 293 if (fobjerr && tobjerr) { 294 ASSERT(di->zerr == ENOENT || di->zerr == ENOTSUP); 295 di->zerr = 0; 296 return (0); 297 } 298 299 di->zerr = 0; /* negate get_stats_for_obj() from side that failed */ 300 fmode = fsb.zs_mode & S_IFMT; 301 tmode = tsb.zs_mode & S_IFMT; 302 if (fmode == S_IFDIR || tmode == S_IFDIR || fsb.zs_links == 0 || 303 tsb.zs_links == 0) 304 change = 0; 305 else 306 change = tsb.zs_links - fsb.zs_links; 307 308 if (fobjerr) { 309 if (change) { 310 print_link_change(fp, di, change, tobjname, &tsb); 311 return (0); 312 } 313 print_file(fp, di, ZDIFF_ADDED, tobjname, &tsb); 314 return (0); 315 } else if (tobjerr) { 316 if (change) { 317 print_link_change(fp, di, change, fobjname, &fsb); 318 return (0); 319 } 320 print_file(fp, di, ZDIFF_REMOVED, fobjname, &fsb); 321 return (0); 322 } 323 324 if (fmode != tmode && fsb.zs_gen == tsb.zs_gen) 325 tsb.zs_gen++; /* Force a generational difference */ 326 same_name = do_name_cmp(fobjname, tobjname); 327 328 /* Simple modification or no change */ 329 if (fsb.zs_gen == tsb.zs_gen) { 330 /* No apparent changes. Could we assert !this? */ 331 if (fsb.zs_ctime[0] == tsb.zs_ctime[0] && 332 fsb.zs_ctime[1] == tsb.zs_ctime[1]) 333 return (0); 334 if (change) { 335 print_link_change(fp, di, change, 336 change > 0 ? fobjname : tobjname, &tsb); 337 } else if (same_name) { 338 print_file(fp, di, ZDIFF_MODIFIED, fobjname, &tsb); 339 } else { 340 print_rename(fp, di, fobjname, tobjname, &tsb); 341 } 342 return (0); 343 } else { 344 /* file re-created or object re-used */ 345 print_file(fp, di, ZDIFF_REMOVED, fobjname, &fsb); 346 print_file(fp, di, ZDIFF_ADDED, tobjname, &tsb); 347 return (0); 348 } 349} 350 351static int 352write_inuse_diffs(FILE *fp, differ_info_t *di, dmu_diff_record_t *dr) 353{ 354 uint64_t o; 355 int err; 356 357 for (o = dr->ddr_first; o <= dr->ddr_last; o++) { 358 if ((err = write_inuse_diffs_one(fp, di, o)) != 0) 359 return (err); 360 } 361 return (0); 362} 363 364static int 365describe_free(FILE *fp, differ_info_t *di, uint64_t object, char *namebuf, 366 int maxlen) 367{ 368 struct zfs_stat sb; 369 370 if (get_stats_for_obj(di, di->fromsnap, object, namebuf, 371 maxlen, &sb) != 0) { 372 /* Let it slide, if in the delete queue on from side */ 373 if (di->zerr == ENOENT && sb.zs_links == 0) { 374 di->zerr = 0; 375 return (0); 376 } 377 return (-1); 378 } 379 380 print_file(fp, di, ZDIFF_REMOVED, namebuf, &sb); 381 return (0); 382} 383 384static int 385write_free_diffs(FILE *fp, differ_info_t *di, dmu_diff_record_t *dr) 386{ 387 zfs_cmd_t zc = { 0 }; 388 libzfs_handle_t *lhdl = di->zhp->zfs_hdl; 389 char fobjname[MAXPATHLEN]; 390 391 (void) strlcpy(zc.zc_name, di->fromsnap, sizeof (zc.zc_name)); 392 zc.zc_obj = dr->ddr_first - 1; 393 394 ASSERT(di->zerr == 0); 395 396 while (zc.zc_obj < dr->ddr_last) { 397 int err; 398 399 err = ioctl(lhdl->libzfs_fd, ZFS_IOC_NEXT_OBJ, &zc); 400 if (err == 0) { 401 if (zc.zc_obj == di->shares) { 402 zc.zc_obj++; 403 continue; 404 } 405 if (zc.zc_obj > dr->ddr_last) { 406 break; 407 } 408 err = describe_free(fp, di, zc.zc_obj, fobjname, 409 MAXPATHLEN); 410 if (err) 411 break; 412 } else if (errno == ESRCH) { 413 break; 414 } else { 415 (void) snprintf(di->errbuf, sizeof (di->errbuf), 416 dgettext(TEXT_DOMAIN, 417 "next allocated object (> %lld) find failure"), 418 zc.zc_obj); 419 di->zerr = errno; 420 break; 421 } 422 } 423 if (di->zerr) 424 return (-1); 425 return (0); 426} 427 428static void * 429differ(void *arg) 430{ 431 differ_info_t *di = arg; 432 dmu_diff_record_t dr; 433 FILE *ofp; 434 int err = 0; 435 436 if ((ofp = fdopen(di->outputfd, "w")) == NULL) { 437 di->zerr = errno; 438 (void) strerror_r(errno, di->errbuf, sizeof (di->errbuf)); 439 (void) close(di->datafd); 440 return ((void *)-1); 441 } 442 443 for (;;) { 444 char *cp = (char *)&dr; 445 int len = sizeof (dr); 446 int rv; 447 448 do { 449 rv = read(di->datafd, cp, len); 450 cp += rv; 451 len -= rv; 452 } while (len > 0 && rv > 0); 453 454 if (rv < 0 || (rv == 0 && len != sizeof (dr))) { 455 di->zerr = EPIPE; 456 break; 457 } else if (rv == 0) { 458 /* end of file at a natural breaking point */ 459 break; 460 } 461 462 switch (dr.ddr_type) { 463 case DDR_FREE: 464 err = write_free_diffs(ofp, di, &dr); 465 break; 466 case DDR_INUSE: 467 err = write_inuse_diffs(ofp, di, &dr); 468 break; 469 default: 470 di->zerr = EPIPE; 471 break; 472 } 473 474 if (err || di->zerr) 475 break; 476 } 477 478 (void) fclose(ofp); 479 (void) close(di->datafd); 480 if (err) 481 return ((void *)-1); 482 if (di->zerr) { 483 ASSERT(di->zerr == EINVAL); 484 (void) snprintf(di->errbuf, sizeof (di->errbuf), 485 dgettext(TEXT_DOMAIN, 486 "Internal error: bad data from diff IOCTL")); 487 return ((void *)-1); 488 } 489 return ((void *)0); 490} 491 492static int 493find_shares_object(differ_info_t *di) 494{ 495 char fullpath[MAXPATHLEN]; 496 struct stat64 sb = { 0 }; 497 498 (void) strlcpy(fullpath, di->dsmnt, MAXPATHLEN); 499 (void) strlcat(fullpath, ZDIFF_SHARESDIR, MAXPATHLEN); 500 501 if (stat64(fullpath, &sb) != 0) { 502#ifdef illumos 503 (void) snprintf(di->errbuf, sizeof (di->errbuf), 504 dgettext(TEXT_DOMAIN, "Cannot stat %s"), fullpath); 505 return (zfs_error(di->zhp->zfs_hdl, EZFS_DIFF, di->errbuf)); 506#else 507 return (0); 508#endif 509 } 510 511 di->shares = (uint64_t)sb.st_ino; 512 return (0); 513} 514 515static int 516make_temp_snapshot(differ_info_t *di) 517{ 518 libzfs_handle_t *hdl = di->zhp->zfs_hdl; 519 zfs_cmd_t zc = { 0 }; 520 521 (void) snprintf(zc.zc_value, sizeof (zc.zc_value), 522 ZDIFF_PREFIX, getpid()); 523 (void) strlcpy(zc.zc_name, di->ds, sizeof (zc.zc_name)); 524 zc.zc_cleanup_fd = di->cleanupfd; 525 526 if (ioctl(hdl->libzfs_fd, ZFS_IOC_TMP_SNAPSHOT, &zc) != 0) { 527 int err = errno; 528 if (err == EPERM) { 529 (void) snprintf(di->errbuf, sizeof (di->errbuf), 530 dgettext(TEXT_DOMAIN, "The diff delegated " 531 "permission is needed in order\nto create a " 532 "just-in-time snapshot for diffing\n")); 533 return (zfs_error(hdl, EZFS_DIFF, di->errbuf)); 534 } else { 535 (void) snprintf(di->errbuf, sizeof (di->errbuf), 536 dgettext(TEXT_DOMAIN, "Cannot create just-in-time " 537 "snapshot of '%s'"), zc.zc_name); 538 return (zfs_standard_error(hdl, err, di->errbuf)); 539 } 540 } 541 542 di->tmpsnap = zfs_strdup(hdl, zc.zc_value); 543 di->tosnap = zfs_asprintf(hdl, "%s@%s", di->ds, di->tmpsnap); 544 return (0); 545} 546 547static void 548teardown_differ_info(differ_info_t *di) 549{ 550 free(di->ds); 551 free(di->dsmnt); 552 free(di->fromsnap); 553 free(di->frommnt); 554 free(di->tosnap); 555 free(di->tmpsnap); 556 free(di->tomnt); 557 (void) close(di->cleanupfd); 558} 559 560static int 561get_snapshot_names(differ_info_t *di, const char *fromsnap, 562 const char *tosnap) 563{ 564 libzfs_handle_t *hdl = di->zhp->zfs_hdl; 565 char *atptrf = NULL; 566 char *atptrt = NULL; 567 int fdslen, fsnlen; 568 int tdslen, tsnlen; 569 570 /* 571 * Can accept 572 * dataset@snap1 573 * dataset@snap1 dataset@snap2 574 * dataset@snap1 @snap2 575 * dataset@snap1 dataset 576 * @snap1 dataset@snap2 577 */ 578 if (tosnap == NULL) { 579 /* only a from snapshot given, must be valid */ 580 (void) snprintf(di->errbuf, sizeof (di->errbuf), 581 dgettext(TEXT_DOMAIN, 582 "Badly formed snapshot name %s"), fromsnap); 583 584 if (!zfs_validate_name(hdl, fromsnap, ZFS_TYPE_SNAPSHOT, 585 B_FALSE)) { 586 return (zfs_error(hdl, EZFS_INVALIDNAME, 587 di->errbuf)); 588 } 589 590 atptrf = strchr(fromsnap, '@'); 591 ASSERT(atptrf != NULL); 592 fdslen = atptrf - fromsnap; 593 594 di->fromsnap = zfs_strdup(hdl, fromsnap); 595 di->ds = zfs_strdup(hdl, fromsnap); 596 di->ds[fdslen] = '\0'; 597 598 /* the to snap will be a just-in-time snap of the head */ 599 return (make_temp_snapshot(di)); 600 } 601 602 (void) snprintf(di->errbuf, sizeof (di->errbuf), 603 dgettext(TEXT_DOMAIN, 604 "Unable to determine which snapshots to compare")); 605 606 atptrf = strchr(fromsnap, '@'); 607 atptrt = strchr(tosnap, '@'); 608 fdslen = atptrf ? atptrf - fromsnap : strlen(fromsnap); 609 tdslen = atptrt ? atptrt - tosnap : strlen(tosnap); 610 fsnlen = strlen(fromsnap) - fdslen; /* includes @ sign */ 611 tsnlen = strlen(tosnap) - tdslen; /* includes @ sign */ 612 613 if (fsnlen <= 1 || tsnlen == 1 || (fdslen == 0 && tdslen == 0) || 614 (fsnlen == 0 && tsnlen == 0)) { 615 return (zfs_error(hdl, EZFS_INVALIDNAME, di->errbuf)); 616 } else if ((fdslen > 0 && tdslen > 0) && 617 ((tdslen != fdslen || strncmp(fromsnap, tosnap, fdslen) != 0))) { 618 /* 619 * not the same dataset name, might be okay if 620 * tosnap is a clone of a fromsnap descendant. 621 */ 622 char origin[ZFS_MAX_DATASET_NAME_LEN]; 623 zprop_source_t src; 624 zfs_handle_t *zhp; 625 626 di->ds = zfs_alloc(di->zhp->zfs_hdl, tdslen + 1); 627 (void) strncpy(di->ds, tosnap, tdslen); 628 di->ds[tdslen] = '\0'; 629 630 zhp = zfs_open(hdl, di->ds, ZFS_TYPE_FILESYSTEM); 631 while (zhp != NULL) { 632 if (zfs_prop_get(zhp, ZFS_PROP_ORIGIN, origin, 633 sizeof (origin), &src, NULL, 0, B_FALSE) != 0) { 634 (void) zfs_close(zhp); 635 zhp = NULL; 636 break; 637 } 638 if (strncmp(origin, fromsnap, fsnlen) == 0) 639 break; 640 641 (void) zfs_close(zhp); 642 zhp = zfs_open(hdl, origin, ZFS_TYPE_FILESYSTEM); 643 } 644 645 if (zhp == NULL) { 646 (void) snprintf(di->errbuf, sizeof (di->errbuf), 647 dgettext(TEXT_DOMAIN, 648 "Not an earlier snapshot from the same fs")); 649 return (zfs_error(hdl, EZFS_INVALIDNAME, di->errbuf)); 650 } else { 651 (void) zfs_close(zhp); 652 } 653 654 di->isclone = B_TRUE; 655 di->fromsnap = zfs_strdup(hdl, fromsnap); 656 if (tsnlen) { 657 di->tosnap = zfs_strdup(hdl, tosnap); 658 } else { 659 return (make_temp_snapshot(di)); 660 } 661 } else { 662 int dslen = fdslen ? fdslen : tdslen; 663 664 di->ds = zfs_alloc(hdl, dslen + 1); 665 (void) strncpy(di->ds, fdslen ? fromsnap : tosnap, dslen); 666 di->ds[dslen] = '\0'; 667 668 di->fromsnap = zfs_asprintf(hdl, "%s%s", di->ds, atptrf); 669 if (tsnlen) { 670 di->tosnap = zfs_asprintf(hdl, "%s%s", di->ds, atptrt); 671 } else { 672 return (make_temp_snapshot(di)); 673 } 674 } 675 return (0); 676} 677 678static int 679get_mountpoint(differ_info_t *di, char *dsnm, char **mntpt) 680{ 681 boolean_t mounted; 682 683 mounted = is_mounted(di->zhp->zfs_hdl, dsnm, mntpt); 684 if (mounted == B_FALSE) { 685 (void) snprintf(di->errbuf, sizeof (di->errbuf), 686 dgettext(TEXT_DOMAIN, 687 "Cannot diff an unmounted snapshot")); 688 return (zfs_error(di->zhp->zfs_hdl, EZFS_BADTYPE, di->errbuf)); 689 } 690 691 /* Avoid a double slash at the beginning of root-mounted datasets */ 692 if (**mntpt == '/' && *(*mntpt + 1) == '\0') 693 **mntpt = '\0'; 694 return (0); 695} 696 697static int 698get_mountpoints(differ_info_t *di) 699{ 700 char *strptr; 701 char *frommntpt; 702 703 /* 704 * first get the mountpoint for the parent dataset 705 */ 706 if (get_mountpoint(di, di->ds, &di->dsmnt) != 0) 707 return (-1); 708 709 strptr = strchr(di->tosnap, '@'); 710 ASSERT3P(strptr, !=, NULL); 711 di->tomnt = zfs_asprintf(di->zhp->zfs_hdl, "%s%s%s", di->dsmnt, 712 ZDIFF_SNAPDIR, ++strptr); 713 714 strptr = strchr(di->fromsnap, '@'); 715 ASSERT3P(strptr, !=, NULL); 716 717 frommntpt = di->dsmnt; 718 if (di->isclone) { 719 char *mntpt; 720 int err; 721 722 *strptr = '\0'; 723 err = get_mountpoint(di, di->fromsnap, &mntpt); 724 *strptr = '@'; 725 if (err != 0) 726 return (-1); 727 frommntpt = mntpt; 728 } 729 730 di->frommnt = zfs_asprintf(di->zhp->zfs_hdl, "%s%s%s", frommntpt, 731 ZDIFF_SNAPDIR, ++strptr); 732 733 if (di->isclone) 734 free(frommntpt); 735 736 return (0); 737} 738 739static int 740setup_differ_info(zfs_handle_t *zhp, const char *fromsnap, 741 const char *tosnap, differ_info_t *di) 742{ 743 di->zhp = zhp; 744 745 di->cleanupfd = open(ZFS_DEV, O_RDWR|O_EXCL); 746 VERIFY(di->cleanupfd >= 0); 747 748 if (get_snapshot_names(di, fromsnap, tosnap) != 0) 749 return (-1); 750 751 if (get_mountpoints(di) != 0) 752 return (-1); 753 754 if (find_shares_object(di) != 0) 755 return (-1); 756 757 return (0); 758} 759 760int 761zfs_show_diffs(zfs_handle_t *zhp, int outfd, const char *fromsnap, 762 const char *tosnap, int flags) 763{ 764 zfs_cmd_t zc = { 0 }; 765 char errbuf[1024]; 766 differ_info_t di = { 0 }; 767 pthread_t tid; 768 int pipefd[2]; 769 int iocerr; 770 771 (void) snprintf(errbuf, sizeof (errbuf), 772 dgettext(TEXT_DOMAIN, "zfs diff failed")); 773 774 if (setup_differ_info(zhp, fromsnap, tosnap, &di)) { 775 teardown_differ_info(&di); 776 return (-1); 777 } 778 779 if (pipe(pipefd)) { 780 zfs_error_aux(zhp->zfs_hdl, strerror(errno)); 781 teardown_differ_info(&di); 782 return (zfs_error(zhp->zfs_hdl, EZFS_PIPEFAILED, errbuf)); 783 } 784 785 di.scripted = (flags & ZFS_DIFF_PARSEABLE); 786 di.classify = (flags & ZFS_DIFF_CLASSIFY); 787 di.timestamped = (flags & ZFS_DIFF_TIMESTAMP); 788 789 di.outputfd = outfd; 790 di.datafd = pipefd[0]; 791 792 if (pthread_create(&tid, NULL, differ, &di)) { 793 zfs_error_aux(zhp->zfs_hdl, strerror(errno)); 794 (void) close(pipefd[0]); 795 (void) close(pipefd[1]); 796 teardown_differ_info(&di); 797 return (zfs_error(zhp->zfs_hdl, 798 EZFS_THREADCREATEFAILED, errbuf)); 799 } 800 801 /* do the ioctl() */ 802 (void) strlcpy(zc.zc_value, di.fromsnap, strlen(di.fromsnap) + 1); 803 (void) strlcpy(zc.zc_name, di.tosnap, strlen(di.tosnap) + 1); 804 zc.zc_cookie = pipefd[1]; 805 806 iocerr = ioctl(zhp->zfs_hdl->libzfs_fd, ZFS_IOC_DIFF, &zc); 807 if (iocerr != 0) { 808 (void) snprintf(errbuf, sizeof (errbuf), 809 dgettext(TEXT_DOMAIN, "Unable to obtain diffs")); 810 if (errno == EPERM) { 811 zfs_error_aux(zhp->zfs_hdl, dgettext(TEXT_DOMAIN, 812 "\n The sys_mount privilege or diff delegated " 813 "permission is needed\n to execute the " 814 "diff ioctl")); 815 } else if (errno == EXDEV) { 816 zfs_error_aux(zhp->zfs_hdl, dgettext(TEXT_DOMAIN, 817 "\n Not an earlier snapshot from the same fs")); 818 } else if (errno != EPIPE || di.zerr == 0) { 819 zfs_error_aux(zhp->zfs_hdl, strerror(errno)); 820 } 821 (void) close(pipefd[1]); 822 (void) pthread_cancel(tid); 823 (void) pthread_join(tid, NULL); 824 teardown_differ_info(&di); 825 if (di.zerr != 0 && di.zerr != EPIPE) { 826 zfs_error_aux(zhp->zfs_hdl, strerror(di.zerr)); 827 return (zfs_error(zhp->zfs_hdl, EZFS_DIFF, di.errbuf)); 828 } else { 829 return (zfs_error(zhp->zfs_hdl, EZFS_DIFFDATA, errbuf)); 830 } 831 } 832 833 (void) close(pipefd[1]); 834 (void) pthread_join(tid, NULL); 835 836 if (di.zerr != 0) { 837 zfs_error_aux(zhp->zfs_hdl, strerror(di.zerr)); 838 return (zfs_error(zhp->zfs_hdl, EZFS_DIFF, di.errbuf)); 839 } 840 teardown_differ_info(&di); 841 return (0); 842} 843