libzfs_diff.c revision 325147
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 58typedef 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 */ 82static int 83get_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 */ 130static void 131stream_bytes(FILE *fp, const char *string) 132{ 133 char c; 134 135 while ((c = *string++) != '\0') { 136 if (c > ' ' && c != '\\' && c < '\177') { 137 (void) fprintf(fp, "%c", c); 138 } else { 139 (void) fprintf(fp, "\\%03o", (uint8_t)c); 140 } 141 } 142} 143 144static void 145print_what(FILE *fp, mode_t what) 146{ 147 char symbol; 148 149 switch (what & S_IFMT) { 150 case S_IFBLK: 151 symbol = 'B'; 152 break; 153 case S_IFCHR: 154 symbol = 'C'; 155 break; 156 case S_IFDIR: 157 symbol = '/'; 158 break; 159#ifdef S_IFDOOR 160 case S_IFDOOR: 161 symbol = '>'; 162 break; 163#endif 164 case S_IFIFO: 165 symbol = '|'; 166 break; 167 case S_IFLNK: 168 symbol = '@'; 169 break; 170#ifdef S_IFPORT 171 case S_IFPORT: 172 symbol = 'P'; 173 break; 174#endif 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 188static void 189print_cmn(FILE *fp, differ_info_t *di, const char *file) 190{ 191 stream_bytes(fp, di->dsmnt); 192 stream_bytes(fp, file); 193} 194 195static void 196print_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 217static void 218print_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 235static void 236print_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 252static int 253write_inuse_diffs_one(FILE *fp, differ_info_t *di, uint64_t dobj) 254{ 255 struct zfs_stat fsb, tsb; 256 mode_t fmode, tmode; 257 char fobjname[MAXPATHLEN], tobjname[MAXPATHLEN]; 258 int fobjerr, tobjerr; 259 int change; 260 261 if (dobj == di->shares) 262 return (0); 263 264 /* 265 * Check the from and to snapshots for info on the object. If 266 * we get ENOENT, then the object just didn't exist in that 267 * snapshot. If we get ENOTSUP, then we tried to get 268 * info on a non-ZPL object, which we don't care about anyway. 269 */ 270 fobjerr = get_stats_for_obj(di, di->fromsnap, dobj, fobjname, 271 MAXPATHLEN, &fsb); 272 if (fobjerr && di->zerr != ENOENT && di->zerr != ENOTSUP) 273 return (-1); 274 275 tobjerr = get_stats_for_obj(di, di->tosnap, dobj, tobjname, 276 MAXPATHLEN, &tsb); 277 if (tobjerr && di->zerr != ENOENT && di->zerr != ENOTSUP) 278 return (-1); 279 280 /* 281 * Unallocated object sharing the same meta dnode block 282 */ 283 if (fobjerr && tobjerr) { 284 ASSERT(di->zerr == ENOENT || di->zerr == ENOTSUP); 285 di->zerr = 0; 286 return (0); 287 } 288 289 di->zerr = 0; /* negate get_stats_for_obj() from side that failed */ 290 fmode = fsb.zs_mode & S_IFMT; 291 tmode = tsb.zs_mode & S_IFMT; 292 if (fmode == S_IFDIR || tmode == S_IFDIR || fsb.zs_links == 0 || 293 tsb.zs_links == 0) 294 change = 0; 295 else 296 change = tsb.zs_links - fsb.zs_links; 297 298 if (fobjerr) { 299 if (change) { 300 print_link_change(fp, di, change, tobjname, &tsb); 301 return (0); 302 } 303 print_file(fp, di, ZDIFF_ADDED, tobjname, &tsb); 304 return (0); 305 } else if (tobjerr) { 306 if (change) { 307 print_link_change(fp, di, change, fobjname, &fsb); 308 return (0); 309 } 310 print_file(fp, di, ZDIFF_REMOVED, fobjname, &fsb); 311 return (0); 312 } 313 314 if (fmode != tmode && fsb.zs_gen == tsb.zs_gen) 315 tsb.zs_gen++; /* Force a generational difference */ 316 317 /* Simple modification or no change */ 318 if (fsb.zs_gen == tsb.zs_gen) { 319 /* No apparent changes. Could we assert !this? */ 320 if (fsb.zs_ctime[0] == tsb.zs_ctime[0] && 321 fsb.zs_ctime[1] == tsb.zs_ctime[1]) 322 return (0); 323 if (change) { 324 print_link_change(fp, di, change, 325 change > 0 ? fobjname : tobjname, &tsb); 326 } else if (strcmp(fobjname, tobjname) == 0) { 327 print_file(fp, di, ZDIFF_MODIFIED, fobjname, &tsb); 328 } else { 329 print_rename(fp, di, fobjname, tobjname, &tsb); 330 } 331 return (0); 332 } else { 333 /* file re-created or object re-used */ 334 print_file(fp, di, ZDIFF_REMOVED, fobjname, &fsb); 335 print_file(fp, di, ZDIFF_ADDED, tobjname, &tsb); 336 return (0); 337 } 338} 339 340static int 341write_inuse_diffs(FILE *fp, differ_info_t *di, dmu_diff_record_t *dr) 342{ 343 uint64_t o; 344 int err; 345 346 for (o = dr->ddr_first; o <= dr->ddr_last; o++) { 347 if ((err = write_inuse_diffs_one(fp, di, o)) != 0) 348 return (err); 349 } 350 return (0); 351} 352 353static int 354describe_free(FILE *fp, differ_info_t *di, uint64_t object, char *namebuf, 355 int maxlen) 356{ 357 struct zfs_stat sb; 358 359 if (get_stats_for_obj(di, di->fromsnap, object, namebuf, 360 maxlen, &sb) != 0) { 361 /* Let it slide, if in the delete queue on from side */ 362 if (di->zerr == ENOENT && sb.zs_links == 0) { 363 di->zerr = 0; 364 return (0); 365 } 366 return (-1); 367 } 368 369 print_file(fp, di, ZDIFF_REMOVED, namebuf, &sb); 370 return (0); 371} 372 373static int 374write_free_diffs(FILE *fp, differ_info_t *di, dmu_diff_record_t *dr) 375{ 376 zfs_cmd_t zc = { 0 }; 377 libzfs_handle_t *lhdl = di->zhp->zfs_hdl; 378 char fobjname[MAXPATHLEN]; 379 380 (void) strlcpy(zc.zc_name, di->fromsnap, sizeof (zc.zc_name)); 381 zc.zc_obj = dr->ddr_first - 1; 382 383 ASSERT(di->zerr == 0); 384 385 while (zc.zc_obj < dr->ddr_last) { 386 int err; 387 388 err = ioctl(lhdl->libzfs_fd, ZFS_IOC_NEXT_OBJ, &zc); 389 if (err == 0) { 390 if (zc.zc_obj == di->shares) { 391 zc.zc_obj++; 392 continue; 393 } 394 if (zc.zc_obj > dr->ddr_last) { 395 break; 396 } 397 err = describe_free(fp, di, zc.zc_obj, fobjname, 398 MAXPATHLEN); 399 if (err) 400 break; 401 } else if (errno == ESRCH) { 402 break; 403 } else { 404 (void) snprintf(di->errbuf, sizeof (di->errbuf), 405 dgettext(TEXT_DOMAIN, 406 "next allocated object (> %lld) find failure"), 407 zc.zc_obj); 408 di->zerr = errno; 409 break; 410 } 411 } 412 if (di->zerr) 413 return (-1); 414 return (0); 415} 416 417static void * 418differ(void *arg) 419{ 420 differ_info_t *di = arg; 421 dmu_diff_record_t dr; 422 FILE *ofp; 423 int err = 0; 424 425 if ((ofp = fdopen(di->outputfd, "w")) == NULL) { 426 di->zerr = errno; 427 (void) strerror_r(errno, di->errbuf, sizeof (di->errbuf)); 428 (void) close(di->datafd); 429 return ((void *)-1); 430 } 431 432 for (;;) { 433 char *cp = (char *)&dr; 434 int len = sizeof (dr); 435 int rv; 436 437 do { 438 rv = read(di->datafd, cp, len); 439 cp += rv; 440 len -= rv; 441 } while (len > 0 && rv > 0); 442 443 if (rv < 0 || (rv == 0 && len != sizeof (dr))) { 444 di->zerr = EPIPE; 445 break; 446 } else if (rv == 0) { 447 /* end of file at a natural breaking point */ 448 break; 449 } 450 451 switch (dr.ddr_type) { 452 case DDR_FREE: 453 err = write_free_diffs(ofp, di, &dr); 454 break; 455 case DDR_INUSE: 456 err = write_inuse_diffs(ofp, di, &dr); 457 break; 458 default: 459 di->zerr = EPIPE; 460 break; 461 } 462 463 if (err || di->zerr) 464 break; 465 } 466 467 (void) fclose(ofp); 468 (void) close(di->datafd); 469 if (err) 470 return ((void *)-1); 471 if (di->zerr) { 472 ASSERT(di->zerr == EINVAL); 473 (void) snprintf(di->errbuf, sizeof (di->errbuf), 474 dgettext(TEXT_DOMAIN, 475 "Internal error: bad data from diff IOCTL")); 476 return ((void *)-1); 477 } 478 return ((void *)0); 479} 480 481static int 482find_shares_object(differ_info_t *di) 483{ 484 char fullpath[MAXPATHLEN]; 485 struct stat64 sb = { 0 }; 486 487 (void) strlcpy(fullpath, di->dsmnt, MAXPATHLEN); 488 (void) strlcat(fullpath, ZDIFF_SHARESDIR, MAXPATHLEN); 489 490 if (stat64(fullpath, &sb) != 0) { 491#ifdef illumos 492 (void) snprintf(di->errbuf, sizeof (di->errbuf), 493 dgettext(TEXT_DOMAIN, "Cannot stat %s"), fullpath); 494 return (zfs_error(di->zhp->zfs_hdl, EZFS_DIFF, di->errbuf)); 495#else 496 return (0); 497#endif 498 } 499 500 di->shares = (uint64_t)sb.st_ino; 501 return (0); 502} 503 504static int 505make_temp_snapshot(differ_info_t *di) 506{ 507 libzfs_handle_t *hdl = di->zhp->zfs_hdl; 508 zfs_cmd_t zc = { 0 }; 509 510 (void) snprintf(zc.zc_value, sizeof (zc.zc_value), 511 ZDIFF_PREFIX, getpid()); 512 (void) strlcpy(zc.zc_name, di->ds, sizeof (zc.zc_name)); 513 zc.zc_cleanup_fd = di->cleanupfd; 514 515 if (ioctl(hdl->libzfs_fd, ZFS_IOC_TMP_SNAPSHOT, &zc) != 0) { 516 int err = errno; 517 if (err == EPERM) { 518 (void) snprintf(di->errbuf, sizeof (di->errbuf), 519 dgettext(TEXT_DOMAIN, "The diff delegated " 520 "permission is needed in order\nto create a " 521 "just-in-time snapshot for diffing\n")); 522 return (zfs_error(hdl, EZFS_DIFF, di->errbuf)); 523 } else { 524 (void) snprintf(di->errbuf, sizeof (di->errbuf), 525 dgettext(TEXT_DOMAIN, "Cannot create just-in-time " 526 "snapshot of '%s'"), zc.zc_name); 527 return (zfs_standard_error(hdl, err, di->errbuf)); 528 } 529 } 530 531 di->tmpsnap = zfs_strdup(hdl, zc.zc_value); 532 di->tosnap = zfs_asprintf(hdl, "%s@%s", di->ds, di->tmpsnap); 533 return (0); 534} 535 536static void 537teardown_differ_info(differ_info_t *di) 538{ 539 free(di->ds); 540 free(di->dsmnt); 541 free(di->fromsnap); 542 free(di->frommnt); 543 free(di->tosnap); 544 free(di->tmpsnap); 545 free(di->tomnt); 546 (void) close(di->cleanupfd); 547} 548 549static int 550get_snapshot_names(differ_info_t *di, const char *fromsnap, 551 const char *tosnap) 552{ 553 libzfs_handle_t *hdl = di->zhp->zfs_hdl; 554 char *atptrf = NULL; 555 char *atptrt = NULL; 556 int fdslen, fsnlen; 557 int tdslen, tsnlen; 558 559 /* 560 * Can accept 561 * dataset@snap1 562 * dataset@snap1 dataset@snap2 563 * dataset@snap1 @snap2 564 * dataset@snap1 dataset 565 * @snap1 dataset@snap2 566 */ 567 if (tosnap == NULL) { 568 /* only a from snapshot given, must be valid */ 569 (void) snprintf(di->errbuf, sizeof (di->errbuf), 570 dgettext(TEXT_DOMAIN, 571 "Badly formed snapshot name %s"), fromsnap); 572 573 if (!zfs_validate_name(hdl, fromsnap, ZFS_TYPE_SNAPSHOT, 574 B_FALSE)) { 575 return (zfs_error(hdl, EZFS_INVALIDNAME, 576 di->errbuf)); 577 } 578 579 atptrf = strchr(fromsnap, '@'); 580 ASSERT(atptrf != NULL); 581 fdslen = atptrf - fromsnap; 582 583 di->fromsnap = zfs_strdup(hdl, fromsnap); 584 di->ds = zfs_strdup(hdl, fromsnap); 585 di->ds[fdslen] = '\0'; 586 587 /* the to snap will be a just-in-time snap of the head */ 588 return (make_temp_snapshot(di)); 589 } 590 591 (void) snprintf(di->errbuf, sizeof (di->errbuf), 592 dgettext(TEXT_DOMAIN, 593 "Unable to determine which snapshots to compare")); 594 595 atptrf = strchr(fromsnap, '@'); 596 atptrt = strchr(tosnap, '@'); 597 fdslen = atptrf ? atptrf - fromsnap : strlen(fromsnap); 598 tdslen = atptrt ? atptrt - tosnap : strlen(tosnap); 599 fsnlen = strlen(fromsnap) - fdslen; /* includes @ sign */ 600 tsnlen = strlen(tosnap) - tdslen; /* includes @ sign */ 601 602 if (fsnlen <= 1 || tsnlen == 1 || (fdslen == 0 && tdslen == 0) || 603 (fsnlen == 0 && tsnlen == 0)) { 604 return (zfs_error(hdl, EZFS_INVALIDNAME, di->errbuf)); 605 } else if ((fdslen > 0 && tdslen > 0) && 606 ((tdslen != fdslen || strncmp(fromsnap, tosnap, fdslen) != 0))) { 607 /* 608 * not the same dataset name, might be okay if 609 * tosnap is a clone of a fromsnap descendant. 610 */ 611 char origin[ZFS_MAX_DATASET_NAME_LEN]; 612 zprop_source_t src; 613 zfs_handle_t *zhp; 614 615 di->ds = zfs_alloc(di->zhp->zfs_hdl, tdslen + 1); 616 (void) strncpy(di->ds, tosnap, tdslen); 617 di->ds[tdslen] = '\0'; 618 619 zhp = zfs_open(hdl, di->ds, ZFS_TYPE_FILESYSTEM); 620 while (zhp != NULL) { 621 if (zfs_prop_get(zhp, ZFS_PROP_ORIGIN, origin, 622 sizeof (origin), &src, NULL, 0, B_FALSE) != 0) { 623 (void) zfs_close(zhp); 624 zhp = NULL; 625 break; 626 } 627 if (strncmp(origin, fromsnap, fsnlen) == 0) 628 break; 629 630 (void) zfs_close(zhp); 631 zhp = zfs_open(hdl, origin, ZFS_TYPE_FILESYSTEM); 632 } 633 634 if (zhp == NULL) { 635 (void) snprintf(di->errbuf, sizeof (di->errbuf), 636 dgettext(TEXT_DOMAIN, 637 "Not an earlier snapshot from the same fs")); 638 return (zfs_error(hdl, EZFS_INVALIDNAME, di->errbuf)); 639 } else { 640 (void) zfs_close(zhp); 641 } 642 643 di->isclone = B_TRUE; 644 di->fromsnap = zfs_strdup(hdl, fromsnap); 645 if (tsnlen) { 646 di->tosnap = zfs_strdup(hdl, tosnap); 647 } else { 648 return (make_temp_snapshot(di)); 649 } 650 } else { 651 int dslen = fdslen ? fdslen : tdslen; 652 653 di->ds = zfs_alloc(hdl, dslen + 1); 654 (void) strncpy(di->ds, fdslen ? fromsnap : tosnap, dslen); 655 di->ds[dslen] = '\0'; 656 657 di->fromsnap = zfs_asprintf(hdl, "%s%s", di->ds, atptrf); 658 if (tsnlen) { 659 di->tosnap = zfs_asprintf(hdl, "%s%s", di->ds, atptrt); 660 } else { 661 return (make_temp_snapshot(di)); 662 } 663 } 664 return (0); 665} 666 667static int 668get_mountpoint(differ_info_t *di, char *dsnm, char **mntpt) 669{ 670 boolean_t mounted; 671 672 mounted = is_mounted(di->zhp->zfs_hdl, dsnm, mntpt); 673 if (mounted == B_FALSE) { 674 (void) snprintf(di->errbuf, sizeof (di->errbuf), 675 dgettext(TEXT_DOMAIN, 676 "Cannot diff an unmounted snapshot")); 677 return (zfs_error(di->zhp->zfs_hdl, EZFS_BADTYPE, di->errbuf)); 678 } 679 680 /* Avoid a double slash at the beginning of root-mounted datasets */ 681 if (**mntpt == '/' && *(*mntpt + 1) == '\0') 682 **mntpt = '\0'; 683 return (0); 684} 685 686static int 687get_mountpoints(differ_info_t *di) 688{ 689 char *strptr; 690 char *frommntpt; 691 692 /* 693 * first get the mountpoint for the parent dataset 694 */ 695 if (get_mountpoint(di, di->ds, &di->dsmnt) != 0) 696 return (-1); 697 698 strptr = strchr(di->tosnap, '@'); 699 ASSERT3P(strptr, !=, NULL); 700 di->tomnt = zfs_asprintf(di->zhp->zfs_hdl, "%s%s%s", di->dsmnt, 701 ZDIFF_SNAPDIR, ++strptr); 702 703 strptr = strchr(di->fromsnap, '@'); 704 ASSERT3P(strptr, !=, NULL); 705 706 frommntpt = di->dsmnt; 707 if (di->isclone) { 708 char *mntpt; 709 int err; 710 711 *strptr = '\0'; 712 err = get_mountpoint(di, di->fromsnap, &mntpt); 713 *strptr = '@'; 714 if (err != 0) 715 return (-1); 716 frommntpt = mntpt; 717 } 718 719 di->frommnt = zfs_asprintf(di->zhp->zfs_hdl, "%s%s%s", frommntpt, 720 ZDIFF_SNAPDIR, ++strptr); 721 722 if (di->isclone) 723 free(frommntpt); 724 725 return (0); 726} 727 728static int 729setup_differ_info(zfs_handle_t *zhp, const char *fromsnap, 730 const char *tosnap, differ_info_t *di) 731{ 732 di->zhp = zhp; 733 734 di->cleanupfd = open(ZFS_DEV, O_RDWR|O_EXCL); 735 VERIFY(di->cleanupfd >= 0); 736 737 if (get_snapshot_names(di, fromsnap, tosnap) != 0) 738 return (-1); 739 740 if (get_mountpoints(di) != 0) 741 return (-1); 742 743 if (find_shares_object(di) != 0) 744 return (-1); 745 746 return (0); 747} 748 749int 750zfs_show_diffs(zfs_handle_t *zhp, int outfd, const char *fromsnap, 751 const char *tosnap, int flags) 752{ 753 zfs_cmd_t zc = { 0 }; 754 char errbuf[1024]; 755 differ_info_t di = { 0 }; 756 pthread_t tid; 757 int pipefd[2]; 758 int iocerr; 759 760 (void) snprintf(errbuf, sizeof (errbuf), 761 dgettext(TEXT_DOMAIN, "zfs diff failed")); 762 763 if (setup_differ_info(zhp, fromsnap, tosnap, &di)) { 764 teardown_differ_info(&di); 765 return (-1); 766 } 767 768 if (pipe(pipefd)) { 769 zfs_error_aux(zhp->zfs_hdl, strerror(errno)); 770 teardown_differ_info(&di); 771 return (zfs_error(zhp->zfs_hdl, EZFS_PIPEFAILED, errbuf)); 772 } 773 774 di.scripted = (flags & ZFS_DIFF_PARSEABLE); 775 di.classify = (flags & ZFS_DIFF_CLASSIFY); 776 di.timestamped = (flags & ZFS_DIFF_TIMESTAMP); 777 778 di.outputfd = outfd; 779 di.datafd = pipefd[0]; 780 781 if (pthread_create(&tid, NULL, differ, &di)) { 782 zfs_error_aux(zhp->zfs_hdl, strerror(errno)); 783 (void) close(pipefd[0]); 784 (void) close(pipefd[1]); 785 teardown_differ_info(&di); 786 return (zfs_error(zhp->zfs_hdl, 787 EZFS_THREADCREATEFAILED, errbuf)); 788 } 789 790 /* do the ioctl() */ 791 (void) strlcpy(zc.zc_value, di.fromsnap, strlen(di.fromsnap) + 1); 792 (void) strlcpy(zc.zc_name, di.tosnap, strlen(di.tosnap) + 1); 793 zc.zc_cookie = pipefd[1]; 794 795 iocerr = ioctl(zhp->zfs_hdl->libzfs_fd, ZFS_IOC_DIFF, &zc); 796 if (iocerr != 0) { 797 (void) snprintf(errbuf, sizeof (errbuf), 798 dgettext(TEXT_DOMAIN, "Unable to obtain diffs")); 799 if (errno == EPERM) { 800 zfs_error_aux(zhp->zfs_hdl, dgettext(TEXT_DOMAIN, 801 "\n The sys_mount privilege or diff delegated " 802 "permission is needed\n to execute the " 803 "diff ioctl")); 804 } else if (errno == EXDEV) { 805 zfs_error_aux(zhp->zfs_hdl, dgettext(TEXT_DOMAIN, 806 "\n Not an earlier snapshot from the same fs")); 807 } else if (errno != EPIPE || di.zerr == 0) { 808 zfs_error_aux(zhp->zfs_hdl, strerror(errno)); 809 } 810 (void) close(pipefd[1]); 811 (void) pthread_cancel(tid); 812 (void) pthread_join(tid, NULL); 813 teardown_differ_info(&di); 814 if (di.zerr != 0 && di.zerr != EPIPE) { 815 zfs_error_aux(zhp->zfs_hdl, strerror(di.zerr)); 816 return (zfs_error(zhp->zfs_hdl, EZFS_DIFF, di.errbuf)); 817 } else { 818 return (zfs_error(zhp->zfs_hdl, EZFS_DIFFDATA, errbuf)); 819 } 820 } 821 822 (void) close(pipefd[1]); 823 (void) pthread_join(tid, NULL); 824 825 if (di.zerr != 0) { 826 zfs_error_aux(zhp->zfs_hdl, strerror(di.zerr)); 827 return (zfs_error(zhp->zfs_hdl, EZFS_DIFF, di.errbuf)); 828 } 829 teardown_differ_info(&di); 830 return (0); 831} 832