libzfs_diff.c revision 297121
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 2016 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 <stddef.h> 39#include <unistd.h> 40#include <stdio.h> 41#include <stdlib.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 56static boolean_t 57do_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 65typedef 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 */ 89static int 90get_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 */ 137static void 138stream_bytes(FILE *fp, const char *string) 139{ 140 char c; 141 142 while ((c = *string++) != '\0') { 143 if (c > ' ' && c != '\\' && c < '\177') { 144 (void) fprintf(fp, "%c", c); 145 } else { 146 (void) fprintf(fp, "\\%03o", (uint8_t)c); 147 } 148 } 149} 150 151static void 152print_what(FILE *fp, mode_t what) 153{ 154 char symbol; 155 156 switch (what & S_IFMT) { 157 case S_IFBLK: 158 symbol = 'B'; 159 break; 160 case S_IFCHR: 161 symbol = 'C'; 162 break; 163 case S_IFDIR: 164 symbol = '/'; 165 break; 166#ifdef S_IFDOOR 167 case S_IFDOOR: 168 symbol = '>'; 169 break; 170#endif 171 case S_IFIFO: 172 symbol = '|'; 173 break; 174 case S_IFLNK: 175 symbol = '@'; 176 break; 177#ifdef S_IFPORT 178 case S_IFPORT: 179 symbol = 'P'; 180 break; 181#endif 182 case S_IFSOCK: 183 symbol = '='; 184 break; 185 case S_IFREG: 186 symbol = 'F'; 187 break; 188 default: 189 symbol = '?'; 190 break; 191 } 192 (void) fprintf(fp, "%c", symbol); 193} 194 195static void 196print_cmn(FILE *fp, differ_info_t *di, const char *file) 197{ 198 stream_bytes(fp, di->dsmnt); 199 stream_bytes(fp, file); 200} 201 202static void 203print_rename(FILE *fp, differ_info_t *di, const char *old, const char *new, 204 zfs_stat_t *isb) 205{ 206 if (di->timestamped) 207 (void) fprintf(fp, "%10lld.%09lld\t", 208 (longlong_t)isb->zs_ctime[0], 209 (longlong_t)isb->zs_ctime[1]); 210 (void) fprintf(fp, "%c\t", ZDIFF_RENAMED); 211 if (di->classify) { 212 print_what(fp, isb->zs_mode); 213 (void) fprintf(fp, "\t"); 214 } 215 print_cmn(fp, di, old); 216 if (di->scripted) 217 (void) fprintf(fp, "\t"); 218 else 219 (void) fprintf(fp, " -> "); 220 print_cmn(fp, di, new); 221 (void) fprintf(fp, "\n"); 222} 223 224static void 225print_link_change(FILE *fp, differ_info_t *di, int delta, const char *file, 226 zfs_stat_t *isb) 227{ 228 if (di->timestamped) 229 (void) fprintf(fp, "%10lld.%09lld\t", 230 (longlong_t)isb->zs_ctime[0], 231 (longlong_t)isb->zs_ctime[1]); 232 (void) fprintf(fp, "%c\t", ZDIFF_MODIFIED); 233 if (di->classify) { 234 print_what(fp, isb->zs_mode); 235 (void) fprintf(fp, "\t"); 236 } 237 print_cmn(fp, di, file); 238 (void) fprintf(fp, "\t(%+d)", delta); 239 (void) fprintf(fp, "\n"); 240} 241 242static void 243print_file(FILE *fp, differ_info_t *di, char type, const char *file, 244 zfs_stat_t *isb) 245{ 246 if (di->timestamped) 247 (void) fprintf(fp, "%10lld.%09lld\t", 248 (longlong_t)isb->zs_ctime[0], 249 (longlong_t)isb->zs_ctime[1]); 250 (void) fprintf(fp, "%c\t", type); 251 if (di->classify) { 252 print_what(fp, isb->zs_mode); 253 (void) fprintf(fp, "\t"); 254 } 255 print_cmn(fp, di, file); 256 (void) fprintf(fp, "\n"); 257} 258 259static int 260write_inuse_diffs_one(FILE *fp, differ_info_t *di, uint64_t dobj) 261{ 262 struct zfs_stat fsb, tsb; 263 boolean_t same_name; 264 mode_t fmode, tmode; 265 char fobjname[MAXPATHLEN], tobjname[MAXPATHLEN]; 266 int fobjerr, tobjerr; 267 int change; 268 269 if (dobj == di->shares) 270 return (0); 271 272 /* 273 * Check the from and to snapshots for info on the object. If 274 * we get ENOENT, then the object just didn't exist in that 275 * snapshot. If we get ENOTSUP, then we tried to get 276 * info on a non-ZPL object, which we don't care about anyway. 277 */ 278 fobjerr = get_stats_for_obj(di, di->fromsnap, dobj, fobjname, 279 MAXPATHLEN, &fsb); 280 if (fobjerr && di->zerr != ENOENT && di->zerr != ENOTSUP) 281 return (-1); 282 283 tobjerr = get_stats_for_obj(di, di->tosnap, dobj, tobjname, 284 MAXPATHLEN, &tsb); 285 if (tobjerr && di->zerr != ENOENT && di->zerr != ENOTSUP) 286 return (-1); 287 288 /* 289 * Unallocated object sharing the same meta dnode block 290 */ 291 if (fobjerr && tobjerr) { 292 ASSERT(di->zerr == ENOENT || di->zerr == ENOTSUP); 293 di->zerr = 0; 294 return (0); 295 } 296 297 di->zerr = 0; /* negate get_stats_for_obj() from side that failed */ 298 fmode = fsb.zs_mode & S_IFMT; 299 tmode = tsb.zs_mode & S_IFMT; 300 if (fmode == S_IFDIR || tmode == S_IFDIR || fsb.zs_links == 0 || 301 tsb.zs_links == 0) 302 change = 0; 303 else 304 change = tsb.zs_links - fsb.zs_links; 305 306 if (fobjerr) { 307 if (change) { 308 print_link_change(fp, di, change, tobjname, &tsb); 309 return (0); 310 } 311 print_file(fp, di, ZDIFF_ADDED, tobjname, &tsb); 312 return (0); 313 } else if (tobjerr) { 314 if (change) { 315 print_link_change(fp, di, change, fobjname, &fsb); 316 return (0); 317 } 318 print_file(fp, di, ZDIFF_REMOVED, fobjname, &fsb); 319 return (0); 320 } 321 322 if (fmode != tmode && fsb.zs_gen == tsb.zs_gen) 323 tsb.zs_gen++; /* Force a generational difference */ 324 same_name = do_name_cmp(fobjname, tobjname); 325 326 /* Simple modification or no change */ 327 if (fsb.zs_gen == tsb.zs_gen) { 328 /* No apparent changes. Could we assert !this? */ 329 if (fsb.zs_ctime[0] == tsb.zs_ctime[0] && 330 fsb.zs_ctime[1] == tsb.zs_ctime[1]) 331 return (0); 332 if (change) { 333 print_link_change(fp, di, change, 334 change > 0 ? fobjname : tobjname, &tsb); 335 } else if (same_name) { 336 print_file(fp, di, ZDIFF_MODIFIED, fobjname, &tsb); 337 } else { 338 print_rename(fp, di, fobjname, tobjname, &tsb); 339 } 340 return (0); 341 } else { 342 /* file re-created or object re-used */ 343 print_file(fp, di, ZDIFF_REMOVED, fobjname, &fsb); 344 print_file(fp, di, ZDIFF_ADDED, tobjname, &tsb); 345 return (0); 346 } 347} 348 349static int 350write_inuse_diffs(FILE *fp, differ_info_t *di, dmu_diff_record_t *dr) 351{ 352 uint64_t o; 353 int err; 354 355 for (o = dr->ddr_first; o <= dr->ddr_last; o++) { 356 if (err = write_inuse_diffs_one(fp, di, o)) 357 return (err); 358 } 359 return (0); 360} 361 362static int 363describe_free(FILE *fp, differ_info_t *di, uint64_t object, char *namebuf, 364 int maxlen) 365{ 366 struct zfs_stat sb; 367 368 if (get_stats_for_obj(di, di->fromsnap, object, namebuf, 369 maxlen, &sb) != 0) { 370 /* Let it slide, if in the delete queue on from side */ 371 if (di->zerr == ENOENT && sb.zs_links == 0) { 372 di->zerr = 0; 373 return (0); 374 } 375 return (-1); 376 } 377 378 print_file(fp, di, ZDIFF_REMOVED, namebuf, &sb); 379 return (0); 380} 381 382static int 383write_free_diffs(FILE *fp, differ_info_t *di, dmu_diff_record_t *dr) 384{ 385 zfs_cmd_t zc = { 0 }; 386 libzfs_handle_t *lhdl = di->zhp->zfs_hdl; 387 char fobjname[MAXPATHLEN]; 388 389 (void) strlcpy(zc.zc_name, di->fromsnap, sizeof (zc.zc_name)); 390 zc.zc_obj = dr->ddr_first - 1; 391 392 ASSERT(di->zerr == 0); 393 394 while (zc.zc_obj < dr->ddr_last) { 395 int err; 396 397 err = ioctl(lhdl->libzfs_fd, ZFS_IOC_NEXT_OBJ, &zc); 398 if (err == 0) { 399 if (zc.zc_obj == di->shares) { 400 zc.zc_obj++; 401 continue; 402 } 403 if (zc.zc_obj > dr->ddr_last) { 404 break; 405 } 406 err = describe_free(fp, di, zc.zc_obj, fobjname, 407 MAXPATHLEN); 408 if (err) 409 break; 410 } else if (errno == ESRCH) { 411 break; 412 } else { 413 (void) snprintf(di->errbuf, sizeof (di->errbuf), 414 dgettext(TEXT_DOMAIN, 415 "next allocated object (> %lld) find failure"), 416 zc.zc_obj); 417 di->zerr = errno; 418 break; 419 } 420 } 421 if (di->zerr) 422 return (-1); 423 return (0); 424} 425 426static void * 427differ(void *arg) 428{ 429 differ_info_t *di = arg; 430 dmu_diff_record_t dr; 431 FILE *ofp; 432 int err = 0; 433 434 if ((ofp = fdopen(di->outputfd, "w")) == NULL) { 435 di->zerr = errno; 436 (void) strerror_r(errno, di->errbuf, sizeof (di->errbuf)); 437 (void) close(di->datafd); 438 return ((void *)-1); 439 } 440 441 for (;;) { 442 char *cp = (char *)&dr; 443 int len = sizeof (dr); 444 int rv; 445 446 do { 447 rv = read(di->datafd, cp, len); 448 cp += rv; 449 len -= rv; 450 } while (len > 0 && rv > 0); 451 452 if (rv < 0 || (rv == 0 && len != sizeof (dr))) { 453 di->zerr = EPIPE; 454 break; 455 } else if (rv == 0) { 456 /* end of file at a natural breaking point */ 457 break; 458 } 459 460 switch (dr.ddr_type) { 461 case DDR_FREE: 462 err = write_free_diffs(ofp, di, &dr); 463 break; 464 case DDR_INUSE: 465 err = write_inuse_diffs(ofp, di, &dr); 466 break; 467 default: 468 di->zerr = EPIPE; 469 break; 470 } 471 472 if (err || di->zerr) 473 break; 474 } 475 476 (void) fclose(ofp); 477 (void) close(di->datafd); 478 if (err) 479 return ((void *)-1); 480 if (di->zerr) { 481 ASSERT(di->zerr == EINVAL); 482 (void) snprintf(di->errbuf, sizeof (di->errbuf), 483 dgettext(TEXT_DOMAIN, 484 "Internal error: bad data from diff IOCTL")); 485 return ((void *)-1); 486 } 487 return ((void *)0); 488} 489 490static int 491find_shares_object(differ_info_t *di) 492{ 493 char fullpath[MAXPATHLEN]; 494 struct stat64 sb = { 0 }; 495 496 (void) strlcpy(fullpath, di->dsmnt, MAXPATHLEN); 497 (void) strlcat(fullpath, ZDIFF_SHARESDIR, MAXPATHLEN); 498 499 if (stat64(fullpath, &sb) != 0) { 500#ifdef illumos 501 (void) snprintf(di->errbuf, sizeof (di->errbuf), 502 dgettext(TEXT_DOMAIN, "Cannot stat %s"), fullpath); 503 return (zfs_error(di->zhp->zfs_hdl, EZFS_DIFF, di->errbuf)); 504#else 505 return (0); 506#endif 507 } 508 509 di->shares = (uint64_t)sb.st_ino; 510 return (0); 511} 512 513static int 514make_temp_snapshot(differ_info_t *di) 515{ 516 libzfs_handle_t *hdl = di->zhp->zfs_hdl; 517 zfs_cmd_t zc = { 0 }; 518 519 (void) snprintf(zc.zc_value, sizeof (zc.zc_value), 520 ZDIFF_PREFIX, getpid()); 521 (void) strlcpy(zc.zc_name, di->ds, sizeof (zc.zc_name)); 522 zc.zc_cleanup_fd = di->cleanupfd; 523 524 if (ioctl(hdl->libzfs_fd, ZFS_IOC_TMP_SNAPSHOT, &zc) != 0) { 525 int err = errno; 526 if (err == EPERM) { 527 (void) snprintf(di->errbuf, sizeof (di->errbuf), 528 dgettext(TEXT_DOMAIN, "The diff delegated " 529 "permission is needed in order\nto create a " 530 "just-in-time snapshot for diffing\n")); 531 return (zfs_error(hdl, EZFS_DIFF, di->errbuf)); 532 } else { 533 (void) snprintf(di->errbuf, sizeof (di->errbuf), 534 dgettext(TEXT_DOMAIN, "Cannot create just-in-time " 535 "snapshot of '%s'"), zc.zc_name); 536 return (zfs_standard_error(hdl, err, di->errbuf)); 537 } 538 } 539 540 di->tmpsnap = zfs_strdup(hdl, zc.zc_value); 541 di->tosnap = zfs_asprintf(hdl, "%s@%s", di->ds, di->tmpsnap); 542 return (0); 543} 544 545static void 546teardown_differ_info(differ_info_t *di) 547{ 548 free(di->ds); 549 free(di->dsmnt); 550 free(di->fromsnap); 551 free(di->frommnt); 552 free(di->tosnap); 553 free(di->tmpsnap); 554 free(di->tomnt); 555 (void) close(di->cleanupfd); 556} 557 558static int 559get_snapshot_names(differ_info_t *di, const char *fromsnap, 560 const char *tosnap) 561{ 562 libzfs_handle_t *hdl = di->zhp->zfs_hdl; 563 char *atptrf = NULL; 564 char *atptrt = NULL; 565 int fdslen, fsnlen; 566 int tdslen, tsnlen; 567 568 /* 569 * Can accept 570 * dataset@snap1 571 * dataset@snap1 dataset@snap2 572 * dataset@snap1 @snap2 573 * dataset@snap1 dataset 574 * @snap1 dataset@snap2 575 */ 576 if (tosnap == NULL) { 577 /* only a from snapshot given, must be valid */ 578 (void) snprintf(di->errbuf, sizeof (di->errbuf), 579 dgettext(TEXT_DOMAIN, 580 "Badly formed snapshot name %s"), fromsnap); 581 582 if (!zfs_validate_name(hdl, fromsnap, ZFS_TYPE_SNAPSHOT, 583 B_FALSE)) { 584 return (zfs_error(hdl, EZFS_INVALIDNAME, 585 di->errbuf)); 586 } 587 588 atptrf = strchr(fromsnap, '@'); 589 ASSERT(atptrf != NULL); 590 fdslen = atptrf - fromsnap; 591 592 di->fromsnap = zfs_strdup(hdl, fromsnap); 593 di->ds = zfs_strdup(hdl, fromsnap); 594 di->ds[fdslen] = '\0'; 595 596 /* the to snap will be a just-in-time snap of the head */ 597 return (make_temp_snapshot(di)); 598 } 599 600 (void) snprintf(di->errbuf, sizeof (di->errbuf), 601 dgettext(TEXT_DOMAIN, 602 "Unable to determine which snapshots to compare")); 603 604 atptrf = strchr(fromsnap, '@'); 605 atptrt = strchr(tosnap, '@'); 606 fdslen = atptrf ? atptrf - fromsnap : strlen(fromsnap); 607 tdslen = atptrt ? atptrt - tosnap : strlen(tosnap); 608 fsnlen = strlen(fromsnap) - fdslen; /* includes @ sign */ 609 tsnlen = strlen(tosnap) - tdslen; /* includes @ sign */ 610 611 if (fsnlen <= 1 || tsnlen == 1 || (fdslen == 0 && tdslen == 0) || 612 (fsnlen == 0 && tsnlen == 0)) { 613 return (zfs_error(hdl, EZFS_INVALIDNAME, di->errbuf)); 614 } else if ((fdslen > 0 && tdslen > 0) && 615 ((tdslen != fdslen || strncmp(fromsnap, tosnap, fdslen) != 0))) { 616 /* 617 * not the same dataset name, might be okay if 618 * tosnap is a clone of a fromsnap descendant. 619 */ 620 char origin[ZFS_MAXNAMELEN]; 621 zprop_source_t src; 622 zfs_handle_t *zhp; 623 624 di->ds = zfs_alloc(di->zhp->zfs_hdl, tdslen + 1); 625 (void) strncpy(di->ds, tosnap, tdslen); 626 di->ds[tdslen] = '\0'; 627 628 zhp = zfs_open(hdl, di->ds, ZFS_TYPE_FILESYSTEM); 629 while (zhp != NULL) { 630 if (zfs_prop_get(zhp, ZFS_PROP_ORIGIN, origin, 631 sizeof (origin), &src, NULL, 0, B_FALSE) != 0) { 632 (void) zfs_close(zhp); 633 zhp = NULL; 634 break; 635 } 636 if (strncmp(origin, fromsnap, fsnlen) == 0) 637 break; 638 639 (void) zfs_close(zhp); 640 zhp = zfs_open(hdl, origin, ZFS_TYPE_FILESYSTEM); 641 } 642 643 if (zhp == NULL) { 644 (void) snprintf(di->errbuf, sizeof (di->errbuf), 645 dgettext(TEXT_DOMAIN, 646 "Not an earlier snapshot from the same fs")); 647 return (zfs_error(hdl, EZFS_INVALIDNAME, di->errbuf)); 648 } else { 649 (void) zfs_close(zhp); 650 } 651 652 di->isclone = B_TRUE; 653 di->fromsnap = zfs_strdup(hdl, fromsnap); 654 if (tsnlen) { 655 di->tosnap = zfs_strdup(hdl, tosnap); 656 } else { 657 return (make_temp_snapshot(di)); 658 } 659 } else { 660 int dslen = fdslen ? fdslen : tdslen; 661 662 di->ds = zfs_alloc(hdl, dslen + 1); 663 (void) strncpy(di->ds, fdslen ? fromsnap : tosnap, dslen); 664 di->ds[dslen] = '\0'; 665 666 di->fromsnap = zfs_asprintf(hdl, "%s%s", di->ds, atptrf); 667 if (tsnlen) { 668 di->tosnap = zfs_asprintf(hdl, "%s%s", di->ds, atptrt); 669 } else { 670 return (make_temp_snapshot(di)); 671 } 672 } 673 return (0); 674} 675 676static int 677get_mountpoint(differ_info_t *di, char *dsnm, char **mntpt) 678{ 679 boolean_t mounted; 680 681 mounted = is_mounted(di->zhp->zfs_hdl, dsnm, mntpt); 682 if (mounted == B_FALSE) { 683 (void) snprintf(di->errbuf, sizeof (di->errbuf), 684 dgettext(TEXT_DOMAIN, 685 "Cannot diff an unmounted snapshot")); 686 return (zfs_error(di->zhp->zfs_hdl, EZFS_BADTYPE, di->errbuf)); 687 } 688 689 /* Avoid a double slash at the beginning of root-mounted datasets */ 690 if (**mntpt == '/' && *(*mntpt + 1) == '\0') 691 **mntpt = '\0'; 692 return (0); 693} 694 695static int 696get_mountpoints(differ_info_t *di) 697{ 698 char *strptr; 699 char *frommntpt; 700 701 /* 702 * first get the mountpoint for the parent dataset 703 */ 704 if (get_mountpoint(di, di->ds, &di->dsmnt) != 0) 705 return (-1); 706 707 strptr = strchr(di->tosnap, '@'); 708 ASSERT3P(strptr, !=, NULL); 709 di->tomnt = zfs_asprintf(di->zhp->zfs_hdl, "%s%s%s", di->dsmnt, 710 ZDIFF_SNAPDIR, ++strptr); 711 712 strptr = strchr(di->fromsnap, '@'); 713 ASSERT3P(strptr, !=, NULL); 714 715 frommntpt = di->dsmnt; 716 if (di->isclone) { 717 char *mntpt; 718 int err; 719 720 *strptr = '\0'; 721 err = get_mountpoint(di, di->fromsnap, &mntpt); 722 *strptr = '@'; 723 if (err != 0) 724 return (-1); 725 frommntpt = mntpt; 726 } 727 728 di->frommnt = zfs_asprintf(di->zhp->zfs_hdl, "%s%s%s", frommntpt, 729 ZDIFF_SNAPDIR, ++strptr); 730 731 if (di->isclone) 732 free(frommntpt); 733 734 return (0); 735} 736 737static int 738setup_differ_info(zfs_handle_t *zhp, const char *fromsnap, 739 const char *tosnap, differ_info_t *di) 740{ 741 di->zhp = zhp; 742 743 di->cleanupfd = open(ZFS_DEV, O_RDWR|O_EXCL); 744 VERIFY(di->cleanupfd >= 0); 745 746 if (get_snapshot_names(di, fromsnap, tosnap) != 0) 747 return (-1); 748 749 if (get_mountpoints(di) != 0) 750 return (-1); 751 752 if (find_shares_object(di) != 0) 753 return (-1); 754 755 return (0); 756} 757 758int 759zfs_show_diffs(zfs_handle_t *zhp, int outfd, const char *fromsnap, 760 const char *tosnap, int flags) 761{ 762 zfs_cmd_t zc = { 0 }; 763 char errbuf[1024]; 764 differ_info_t di = { 0 }; 765 pthread_t tid; 766 int pipefd[2]; 767 int iocerr; 768 769 (void) snprintf(errbuf, sizeof (errbuf), 770 dgettext(TEXT_DOMAIN, "zfs diff failed")); 771 772 if (setup_differ_info(zhp, fromsnap, tosnap, &di)) { 773 teardown_differ_info(&di); 774 return (-1); 775 } 776 777 if (pipe(pipefd)) { 778 zfs_error_aux(zhp->zfs_hdl, strerror(errno)); 779 teardown_differ_info(&di); 780 return (zfs_error(zhp->zfs_hdl, EZFS_PIPEFAILED, errbuf)); 781 } 782 783 di.scripted = (flags & ZFS_DIFF_PARSEABLE); 784 di.classify = (flags & ZFS_DIFF_CLASSIFY); 785 di.timestamped = (flags & ZFS_DIFF_TIMESTAMP); 786 787 di.outputfd = outfd; 788 di.datafd = pipefd[0]; 789 790 if (pthread_create(&tid, NULL, differ, &di)) { 791 zfs_error_aux(zhp->zfs_hdl, strerror(errno)); 792 (void) close(pipefd[0]); 793 (void) close(pipefd[1]); 794 teardown_differ_info(&di); 795 return (zfs_error(zhp->zfs_hdl, 796 EZFS_THREADCREATEFAILED, errbuf)); 797 } 798 799 /* do the ioctl() */ 800 (void) strlcpy(zc.zc_value, di.fromsnap, strlen(di.fromsnap) + 1); 801 (void) strlcpy(zc.zc_name, di.tosnap, strlen(di.tosnap) + 1); 802 zc.zc_cookie = pipefd[1]; 803 804 iocerr = ioctl(zhp->zfs_hdl->libzfs_fd, ZFS_IOC_DIFF, &zc); 805 if (iocerr != 0) { 806 (void) snprintf(errbuf, sizeof (errbuf), 807 dgettext(TEXT_DOMAIN, "Unable to obtain diffs")); 808 if (errno == EPERM) { 809 zfs_error_aux(zhp->zfs_hdl, dgettext(TEXT_DOMAIN, 810 "\n The sys_mount privilege or diff delegated " 811 "permission is needed\n to execute the " 812 "diff ioctl")); 813 } else if (errno == EXDEV) { 814 zfs_error_aux(zhp->zfs_hdl, dgettext(TEXT_DOMAIN, 815 "\n Not an earlier snapshot from the same fs")); 816 } else if (errno != EPIPE || di.zerr == 0) { 817 zfs_error_aux(zhp->zfs_hdl, strerror(errno)); 818 } 819 (void) close(pipefd[1]); 820 (void) pthread_cancel(tid); 821 (void) pthread_join(tid, NULL); 822 teardown_differ_info(&di); 823 if (di.zerr != 0 && di.zerr != EPIPE) { 824 zfs_error_aux(zhp->zfs_hdl, strerror(di.zerr)); 825 return (zfs_error(zhp->zfs_hdl, EZFS_DIFF, di.errbuf)); 826 } else { 827 return (zfs_error(zhp->zfs_hdl, EZFS_DIFFDATA, errbuf)); 828 } 829 } 830 831 (void) close(pipefd[1]); 832 (void) pthread_join(tid, NULL); 833 834 if (di.zerr != 0) { 835 zfs_error_aux(zhp->zfs_hdl, strerror(di.zerr)); 836 return (zfs_error(zhp->zfs_hdl, EZFS_DIFF, di.errbuf)); 837 } 838 teardown_differ_info(&di); 839 return (0); 840} 841