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, 2018 by Delphix. All rights reserved.
26 * Copyright 2016 Joyent, Inc.
27 * Copyright 2016 Igor Kozhukhov <[email protected]>
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 <stropts.h>
45 #include <pthread.h>
46 #include <sys/zfs_ioctl.h>
47 #include <libzfs.h>
48 #include "libzfs_impl.h"
49
50 #define ZDIFF_SNAPDIR "/.zfs/snapshot/"
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
58
59 /*
60 * Given a {dsname, object id}, get the object path
61 */
62 static int
get_stats_for_obj(differ_info_t * di,const char * dsname,uint64_t obj,char * pn,int maxlen,zfs_stat_t * sb)63 get_stats_for_obj(differ_info_t *di, const char *dsname, uint64_t obj,
64 char *pn, int maxlen, zfs_stat_t *sb)
65 {
66 zfs_cmd_t zc = {"\0"};
67 int error;
68
69 (void) strlcpy(zc.zc_name, dsname, sizeof (zc.zc_name));
70 zc.zc_obj = obj;
71
72 errno = 0;
73 error = zfs_ioctl(di->zhp->zfs_hdl, ZFS_IOC_OBJ_TO_STATS, &zc);
74 di->zerr = errno;
75
76 /* we can get stats even if we failed to get a path */
77 (void) memcpy(sb, &zc.zc_stat, sizeof (zfs_stat_t));
78 if (error == 0) {
79 ASSERT(di->zerr == 0);
80 (void) strlcpy(pn, zc.zc_value, maxlen);
81 return (0);
82 }
83
84 if (di->zerr == ESTALE) {
85 (void) snprintf(pn, maxlen, "(on_delete_queue)");
86 return (0);
87 } else if (di->zerr == EPERM) {
88 (void) snprintf(di->errbuf, sizeof (di->errbuf),
89 dgettext(TEXT_DOMAIN,
90 "The sys_config privilege or diff delegated permission "
91 "is needed\nto discover path names"));
92 return (-1);
93 } else if (di->zerr == EACCES) {
94 (void) snprintf(di->errbuf, sizeof (di->errbuf),
95 dgettext(TEXT_DOMAIN,
96 "Key must be loaded to discover path names"));
97 return (-1);
98 } else {
99 (void) snprintf(di->errbuf, sizeof (di->errbuf),
100 dgettext(TEXT_DOMAIN,
101 "Unable to determine path or stats for "
102 "object %lld in %s"), (longlong_t)obj, dsname);
103 return (-1);
104 }
105 }
106
107 /*
108 * stream_bytes
109 *
110 * Prints a file name out a character at a time. If the character is
111 * not in the range of what we consider "printable" ASCII, display it
112 * as an escaped 4-digit octal value. ASCII values less than a space
113 * are all control characters and we declare the upper end as the
114 * DELete character. This also is the last 7-bit ASCII character.
115 * We choose to treat all 8-bit ASCII as not printable for this
116 * application.
117 */
118 static void
stream_bytes(FILE * fp,const char * string)119 stream_bytes(FILE *fp, const char *string)
120 {
121 char c;
122
123 while ((c = *string++) != '\0') {
124 if (c > ' ' && c != '\\' && c < '\177') {
125 (void) fprintf(fp, "%c", c);
126 } else {
127 (void) fprintf(fp, "\\%04o", (uint8_t)c);
128 }
129 }
130 }
131
132 static void
print_what(FILE * fp,mode_t what)133 print_what(FILE *fp, mode_t what)
134 {
135 char symbol;
136
137 switch (what & S_IFMT) {
138 case S_IFBLK:
139 symbol = 'B';
140 break;
141 case S_IFCHR:
142 symbol = 'C';
143 break;
144 case S_IFDIR:
145 symbol = '/';
146 break;
147 #ifdef S_IFDOOR
148 case S_IFDOOR:
149 symbol = '>';
150 break;
151 #endif
152 case S_IFIFO:
153 symbol = '|';
154 break;
155 case S_IFLNK:
156 symbol = '@';
157 break;
158 #ifdef S_IFPORT
159 case S_IFPORT:
160 symbol = 'P';
161 break;
162 #endif
163 case S_IFSOCK:
164 symbol = '=';
165 break;
166 case S_IFREG:
167 symbol = 'F';
168 break;
169 default:
170 symbol = '?';
171 break;
172 }
173 (void) fprintf(fp, "%c", symbol);
174 }
175
176 static void
print_cmn(FILE * fp,differ_info_t * di,const char * file)177 print_cmn(FILE *fp, differ_info_t *di, const char *file)
178 {
179 stream_bytes(fp, di->dsmnt);
180 stream_bytes(fp, file);
181 }
182
183 static void
print_rename(FILE * fp,differ_info_t * di,const char * old,const char * new,zfs_stat_t * isb)184 print_rename(FILE *fp, differ_info_t *di, const char *old, const char *new,
185 zfs_stat_t *isb)
186 {
187 if (di->timestamped)
188 (void) fprintf(fp, "%10lld.%09lld\t",
189 (longlong_t)isb->zs_ctime[0],
190 (longlong_t)isb->zs_ctime[1]);
191 (void) fprintf(fp, "%c\t", ZDIFF_RENAMED);
192 if (di->classify) {
193 print_what(fp, isb->zs_mode);
194 (void) fprintf(fp, "\t");
195 }
196 print_cmn(fp, di, old);
197 if (di->scripted)
198 (void) fprintf(fp, "\t");
199 else
200 (void) fprintf(fp, " -> ");
201 print_cmn(fp, di, new);
202 (void) fprintf(fp, "\n");
203 }
204
205 static void
print_link_change(FILE * fp,differ_info_t * di,int delta,const char * file,zfs_stat_t * isb)206 print_link_change(FILE *fp, differ_info_t *di, int delta, const char *file,
207 zfs_stat_t *isb)
208 {
209 if (di->timestamped)
210 (void) fprintf(fp, "%10lld.%09lld\t",
211 (longlong_t)isb->zs_ctime[0],
212 (longlong_t)isb->zs_ctime[1]);
213 (void) fprintf(fp, "%c\t", ZDIFF_MODIFIED);
214 if (di->classify) {
215 print_what(fp, isb->zs_mode);
216 (void) fprintf(fp, "\t");
217 }
218 print_cmn(fp, di, file);
219 (void) fprintf(fp, "\t(%+d)", delta);
220 (void) fprintf(fp, "\n");
221 }
222
223 static void
print_file(FILE * fp,differ_info_t * di,char type,const char * file,zfs_stat_t * isb)224 print_file(FILE *fp, differ_info_t *di, char type, const char *file,
225 zfs_stat_t *isb)
226 {
227 if (di->timestamped)
228 (void) fprintf(fp, "%10lld.%09lld\t",
229 (longlong_t)isb->zs_ctime[0],
230 (longlong_t)isb->zs_ctime[1]);
231 (void) fprintf(fp, "%c\t", type);
232 if (di->classify) {
233 print_what(fp, isb->zs_mode);
234 (void) fprintf(fp, "\t");
235 }
236 print_cmn(fp, di, file);
237 (void) fprintf(fp, "\n");
238 }
239
240 static int
write_inuse_diffs_one(FILE * fp,differ_info_t * di,uint64_t dobj)241 write_inuse_diffs_one(FILE *fp, differ_info_t *di, uint64_t dobj)
242 {
243 struct zfs_stat fsb, tsb;
244 mode_t fmode, tmode;
245 char fobjname[MAXPATHLEN], tobjname[MAXPATHLEN];
246 boolean_t already_logged = B_FALSE;
247 int fobjerr, tobjerr;
248 int change;
249
250 if (dobj == di->shares)
251 return (0);
252
253 /*
254 * Check the from and to snapshots for info on the object. If
255 * we get ENOENT, then the object just didn't exist in that
256 * snapshot. If we get ENOTSUP, then we tried to get
257 * info on a non-ZPL object, which we don't care about anyway.
258 * For any other error we print a warning which includes the
259 * errno and continue.
260 */
261
262 fobjerr = get_stats_for_obj(di, di->fromsnap, dobj, fobjname,
263 MAXPATHLEN, &fsb);
264 if (fobjerr && di->zerr != ENOTSUP && di->zerr != ENOENT) {
265 zfs_error_aux(di->zhp->zfs_hdl, "%s", strerror(di->zerr));
266 zfs_error(di->zhp->zfs_hdl, di->zerr, di->errbuf);
267 /*
268 * Let's not print an error for the same object more than
269 * once if it happens in both snapshots
270 */
271 already_logged = B_TRUE;
272 }
273
274 tobjerr = get_stats_for_obj(di, di->tosnap, dobj, tobjname,
275 MAXPATHLEN, &tsb);
276
277 if (tobjerr && di->zerr != ENOTSUP && di->zerr != ENOENT) {
278 if (!already_logged) {
279 zfs_error_aux(di->zhp->zfs_hdl,
280 "%s", strerror(di->zerr));
281 zfs_error(di->zhp->zfs_hdl, di->zerr, di->errbuf);
282 }
283 }
284 /*
285 * Unallocated object sharing the same meta dnode block
286 */
287 if (fobjerr && tobjerr) {
288 di->zerr = 0;
289 return (0);
290 }
291
292 di->zerr = 0; /* negate get_stats_for_obj() from side that failed */
293 fmode = fsb.zs_mode & S_IFMT;
294 tmode = tsb.zs_mode & S_IFMT;
295 if (fmode == S_IFDIR || tmode == S_IFDIR || fsb.zs_links == 0 ||
296 tsb.zs_links == 0)
297 change = 0;
298 else
299 change = tsb.zs_links - fsb.zs_links;
300
301 if (fobjerr) {
302 if (change) {
303 print_link_change(fp, di, change, tobjname, &tsb);
304 return (0);
305 }
306 print_file(fp, di, ZDIFF_ADDED, tobjname, &tsb);
307 return (0);
308 } else if (tobjerr) {
309 if (change) {
310 print_link_change(fp, di, change, fobjname, &fsb);
311 return (0);
312 }
313 print_file(fp, di, ZDIFF_REMOVED, fobjname, &fsb);
314 return (0);
315 }
316
317 if (fmode != tmode && fsb.zs_gen == tsb.zs_gen)
318 tsb.zs_gen++; /* Force a generational difference */
319
320 /* Simple modification or no change */
321 if (fsb.zs_gen == tsb.zs_gen) {
322 /* No apparent changes. Could we assert !this? */
323 if (fsb.zs_ctime[0] == tsb.zs_ctime[0] &&
324 fsb.zs_ctime[1] == tsb.zs_ctime[1])
325 return (0);
326 if (change) {
327 print_link_change(fp, di, change,
328 change > 0 ? fobjname : tobjname, &tsb);
329 } else if (strcmp(fobjname, tobjname) == 0) {
330 print_file(fp, di, ZDIFF_MODIFIED, fobjname, &tsb);
331 } else {
332 print_rename(fp, di, fobjname, tobjname, &tsb);
333 }
334 return (0);
335 } else {
336 /* file re-created or object re-used */
337 print_file(fp, di, ZDIFF_REMOVED, fobjname, &fsb);
338 print_file(fp, di, ZDIFF_ADDED, tobjname, &tsb);
339 return (0);
340 }
341 }
342
343 static int
write_inuse_diffs(FILE * fp,differ_info_t * di,dmu_diff_record_t * dr)344 write_inuse_diffs(FILE *fp, differ_info_t *di, dmu_diff_record_t *dr)
345 {
346 uint64_t o;
347 int err;
348
349 for (o = dr->ddr_first; o <= dr->ddr_last; o++) {
350 if ((err = write_inuse_diffs_one(fp, di, o)) != 0)
351 return (err);
352 }
353 return (0);
354 }
355
356 static int
describe_free(FILE * fp,differ_info_t * di,uint64_t object,char * namebuf,int maxlen)357 describe_free(FILE *fp, differ_info_t *di, uint64_t object, char *namebuf,
358 int maxlen)
359 {
360 struct zfs_stat sb;
361
362 (void) get_stats_for_obj(di, di->fromsnap, object, namebuf,
363 maxlen, &sb);
364
365 /* Don't print if in the delete queue on from side */
366 if (di->zerr == ESTALE || di->zerr == ENOENT) {
367 di->zerr = 0;
368 return (0);
369 }
370
371 print_file(fp, di, ZDIFF_REMOVED, namebuf, &sb);
372 return (0);
373 }
374
375 static int
write_free_diffs(FILE * fp,differ_info_t * di,dmu_diff_record_t * dr)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 = zfs_ioctl(lhdl, 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 } 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 (longlong_t)zc.zc_obj);
408 di->zerr = errno;
409 break;
410 }
411 }
412 if (di->zerr)
413 return (-1);
414 return (0);
415 }
416
417 static void *
differ(void * arg)418 differ(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 strlcpy(di->errbuf, strerror(errno), 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 == EPIPE);
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
481 static int
make_temp_snapshot(differ_info_t * di)482 make_temp_snapshot(differ_info_t *di)
483 {
484 libzfs_handle_t *hdl = di->zhp->zfs_hdl;
485 zfs_cmd_t zc = {"\0"};
486
487 (void) snprintf(zc.zc_value, sizeof (zc.zc_value),
488 ZDIFF_PREFIX, getpid());
489 (void) strlcpy(zc.zc_name, di->ds, sizeof (zc.zc_name));
490 zc.zc_cleanup_fd = di->cleanupfd;
491
492 if (zfs_ioctl(hdl, ZFS_IOC_TMP_SNAPSHOT, &zc) != 0) {
493 int err = errno;
494 if (err == EPERM) {
495 (void) snprintf(di->errbuf, sizeof (di->errbuf),
496 dgettext(TEXT_DOMAIN, "The diff delegated "
497 "permission is needed in order\nto create a "
498 "just-in-time snapshot for diffing\n"));
499 return (zfs_error(hdl, EZFS_DIFF, di->errbuf));
500 } else {
501 (void) snprintf(di->errbuf, sizeof (di->errbuf),
502 dgettext(TEXT_DOMAIN, "Cannot create just-in-time "
503 "snapshot of '%s'"), zc.zc_name);
504 return (zfs_standard_error(hdl, err, di->errbuf));
505 }
506 }
507
508 di->tmpsnap = zfs_strdup(hdl, zc.zc_value);
509 di->tosnap = zfs_asprintf(hdl, "%s@%s", di->ds, di->tmpsnap);
510 return (0);
511 }
512
513 static void
teardown_differ_info(differ_info_t * di)514 teardown_differ_info(differ_info_t *di)
515 {
516 free(di->ds);
517 free(di->dsmnt);
518 free(di->fromsnap);
519 free(di->frommnt);
520 free(di->tosnap);
521 free(di->tmpsnap);
522 free(di->tomnt);
523 (void) close(di->cleanupfd);
524 }
525
526 static int
get_snapshot_names(differ_info_t * di,const char * fromsnap,const char * tosnap)527 get_snapshot_names(differ_info_t *di, const char *fromsnap,
528 const char *tosnap)
529 {
530 libzfs_handle_t *hdl = di->zhp->zfs_hdl;
531 char *atptrf = NULL;
532 char *atptrt = NULL;
533 int fdslen, fsnlen;
534 int tdslen, tsnlen;
535
536 /*
537 * Can accept
538 * fdslen fsnlen tdslen tsnlen
539 * dataset@snap1
540 * 0. dataset@snap1 dataset@snap2 >0 >1 >0 >1
541 * 1. dataset@snap1 @snap2 >0 >1 ==0 >1
542 * 2. dataset@snap1 dataset >0 >1 >0 ==0
543 * 3. @snap1 dataset@snap2 ==0 >1 >0 >1
544 * 4. @snap1 dataset ==0 >1 >0 ==0
545 */
546 if (tosnap == NULL) {
547 /* only a from snapshot given, must be valid */
548 (void) snprintf(di->errbuf, sizeof (di->errbuf),
549 dgettext(TEXT_DOMAIN,
550 "Badly formed snapshot name %s"), fromsnap);
551
552 if (!zfs_validate_name(hdl, fromsnap, ZFS_TYPE_SNAPSHOT,
553 B_FALSE)) {
554 return (zfs_error(hdl, EZFS_INVALIDNAME,
555 di->errbuf));
556 }
557
558 atptrf = strchr(fromsnap, '@');
559 ASSERT(atptrf != NULL);
560 fdslen = atptrf - fromsnap;
561
562 di->fromsnap = zfs_strdup(hdl, fromsnap);
563 di->ds = zfs_strdup(hdl, fromsnap);
564 di->ds[fdslen] = '\0';
565
566 /* the to snap will be a just-in-time snap of the head */
567 return (make_temp_snapshot(di));
568 }
569
570 (void) snprintf(di->errbuf, sizeof (di->errbuf),
571 dgettext(TEXT_DOMAIN,
572 "Unable to determine which snapshots to compare"));
573
574 atptrf = strchr(fromsnap, '@');
575 atptrt = strchr(tosnap, '@');
576 fdslen = atptrf ? atptrf - fromsnap : strlen(fromsnap);
577 tdslen = atptrt ? atptrt - tosnap : strlen(tosnap);
578 fsnlen = strlen(fromsnap) - fdslen; /* includes @ sign */
579 tsnlen = strlen(tosnap) - tdslen; /* includes @ sign */
580
581 if (fsnlen <= 1 || tsnlen == 1 || (fdslen == 0 && tdslen == 0)) {
582 return (zfs_error(hdl, EZFS_INVALIDNAME, di->errbuf));
583 } else if ((fdslen > 0 && tdslen > 0) &&
584 ((tdslen != fdslen || strncmp(fromsnap, tosnap, fdslen) != 0))) {
585 /*
586 * not the same dataset name, might be okay if
587 * tosnap is a clone of a fromsnap descendant.
588 */
589 char origin[ZFS_MAX_DATASET_NAME_LEN];
590 zprop_source_t src;
591 zfs_handle_t *zhp;
592
593 di->ds = zfs_alloc(di->zhp->zfs_hdl, tdslen + 1);
594 (void) strncpy(di->ds, tosnap, tdslen);
595 di->ds[tdslen] = '\0';
596
597 zhp = zfs_open(hdl, di->ds, ZFS_TYPE_FILESYSTEM);
598 while (zhp != NULL) {
599 if (zfs_prop_get(zhp, ZFS_PROP_ORIGIN, origin,
600 sizeof (origin), &src, NULL, 0, B_FALSE) != 0) {
601 (void) zfs_close(zhp);
602 zhp = NULL;
603 break;
604 }
605 if (strncmp(origin, fromsnap, fsnlen) == 0)
606 break;
607
608 (void) zfs_close(zhp);
609 zhp = zfs_open(hdl, origin, ZFS_TYPE_FILESYSTEM);
610 }
611
612 if (zhp == NULL) {
613 (void) snprintf(di->errbuf, sizeof (di->errbuf),
614 dgettext(TEXT_DOMAIN,
615 "Not an earlier snapshot from the same fs"));
616 return (zfs_error(hdl, EZFS_INVALIDNAME, di->errbuf));
617 } else {
618 (void) zfs_close(zhp);
619 }
620
621 di->isclone = B_TRUE;
622 di->fromsnap = zfs_strdup(hdl, fromsnap);
623 if (tsnlen) {
624 di->tosnap = zfs_strdup(hdl, tosnap);
625 } else {
626 return (make_temp_snapshot(di));
627 }
628 } else {
629 int dslen = fdslen ? fdslen : tdslen;
630
631 di->ds = zfs_alloc(hdl, dslen + 1);
632 (void) strncpy(di->ds, fdslen ? fromsnap : tosnap, dslen);
633 di->ds[dslen] = '\0';
634
635 di->fromsnap = zfs_asprintf(hdl, "%s%s", di->ds, atptrf);
636 if (tsnlen) {
637 di->tosnap = zfs_asprintf(hdl, "%s%s", di->ds, atptrt);
638 } else {
639 return (make_temp_snapshot(di));
640 }
641 }
642 return (0);
643 }
644
645 static int
get_mountpoint(differ_info_t * di,char * dsnm,char ** mntpt)646 get_mountpoint(differ_info_t *di, char *dsnm, char **mntpt)
647 {
648 boolean_t mounted;
649
650 mounted = is_mounted(di->zhp->zfs_hdl, dsnm, mntpt);
651 if (mounted == B_FALSE) {
652 (void) snprintf(di->errbuf, sizeof (di->errbuf),
653 dgettext(TEXT_DOMAIN,
654 "Cannot diff an unmounted snapshot"));
655 return (zfs_error(di->zhp->zfs_hdl, EZFS_BADTYPE, di->errbuf));
656 }
657
658 /* Avoid a double slash at the beginning of root-mounted datasets */
659 if (**mntpt == '/' && *(*mntpt + 1) == '\0')
660 **mntpt = '\0';
661 return (0);
662 }
663
664 static int
get_mountpoints(differ_info_t * di)665 get_mountpoints(differ_info_t *di)
666 {
667 char *strptr;
668 char *frommntpt;
669
670 /*
671 * first get the mountpoint for the parent dataset
672 */
673 if (get_mountpoint(di, di->ds, &di->dsmnt) != 0)
674 return (-1);
675
676 strptr = strchr(di->tosnap, '@');
677 ASSERT3P(strptr, !=, NULL);
678 di->tomnt = zfs_asprintf(di->zhp->zfs_hdl, "%s%s%s", di->dsmnt,
679 ZDIFF_SNAPDIR, ++strptr);
680
681 strptr = strchr(di->fromsnap, '@');
682 ASSERT3P(strptr, !=, NULL);
683
684 frommntpt = di->dsmnt;
685 if (di->isclone) {
686 char *mntpt;
687 int err;
688
689 *strptr = '\0';
690 err = get_mountpoint(di, di->fromsnap, &mntpt);
691 *strptr = '@';
692 if (err != 0)
693 return (-1);
694 frommntpt = mntpt;
695 }
696
697 di->frommnt = zfs_asprintf(di->zhp->zfs_hdl, "%s%s%s", frommntpt,
698 ZDIFF_SNAPDIR, ++strptr);
699
700 if (di->isclone)
701 free(frommntpt);
702
703 return (0);
704 }
705
706 static int
setup_differ_info(zfs_handle_t * zhp,const char * fromsnap,const char * tosnap,differ_info_t * di)707 setup_differ_info(zfs_handle_t *zhp, const char *fromsnap,
708 const char *tosnap, differ_info_t *di)
709 {
710 di->zhp = zhp;
711
712 di->cleanupfd = open(ZFS_DEV, O_RDWR | O_CLOEXEC);
713 VERIFY(di->cleanupfd >= 0);
714
715 if (get_snapshot_names(di, fromsnap, tosnap) != 0)
716 return (-1);
717
718 if (get_mountpoints(di) != 0)
719 return (-1);
720
721 if (find_shares_object(di) != 0)
722 return (-1);
723
724 return (0);
725 }
726
727 int
zfs_show_diffs(zfs_handle_t * zhp,int outfd,const char * fromsnap,const char * tosnap,int flags)728 zfs_show_diffs(zfs_handle_t *zhp, int outfd, const char *fromsnap,
729 const char *tosnap, int flags)
730 {
731 zfs_cmd_t zc = {"\0"};
732 char errbuf[1024];
733 differ_info_t di = { 0 };
734 pthread_t tid;
735 int pipefd[2];
736 int iocerr;
737
738 (void) snprintf(errbuf, sizeof (errbuf),
739 dgettext(TEXT_DOMAIN, "zfs diff failed"));
740
741 if (setup_differ_info(zhp, fromsnap, tosnap, &di)) {
742 teardown_differ_info(&di);
743 return (-1);
744 }
745
746 if (pipe2(pipefd, O_CLOEXEC)) {
747 zfs_error_aux(zhp->zfs_hdl, "%s", strerror(errno));
748 teardown_differ_info(&di);
749 return (zfs_error(zhp->zfs_hdl, EZFS_PIPEFAILED, errbuf));
750 }
751
752 di.scripted = (flags & ZFS_DIFF_PARSEABLE);
753 di.classify = (flags & ZFS_DIFF_CLASSIFY);
754 di.timestamped = (flags & ZFS_DIFF_TIMESTAMP);
755
756 di.outputfd = outfd;
757 di.datafd = pipefd[0];
758
759 if (pthread_create(&tid, NULL, differ, &di)) {
760 zfs_error_aux(zhp->zfs_hdl, "%s", strerror(errno));
761 (void) close(pipefd[0]);
762 (void) close(pipefd[1]);
763 teardown_differ_info(&di);
764 return (zfs_error(zhp->zfs_hdl,
765 EZFS_THREADCREATEFAILED, errbuf));
766 }
767
768 /* do the ioctl() */
769 (void) strlcpy(zc.zc_value, di.fromsnap, strlen(di.fromsnap) + 1);
770 (void) strlcpy(zc.zc_name, di.tosnap, strlen(di.tosnap) + 1);
771 zc.zc_cookie = pipefd[1];
772
773 iocerr = zfs_ioctl(zhp->zfs_hdl, ZFS_IOC_DIFF, &zc);
774 if (iocerr != 0) {
775 (void) snprintf(errbuf, sizeof (errbuf),
776 dgettext(TEXT_DOMAIN, "Unable to obtain diffs"));
777 if (errno == EPERM) {
778 zfs_error_aux(zhp->zfs_hdl, dgettext(TEXT_DOMAIN,
779 "\n The sys_mount privilege or diff delegated "
780 "permission is needed\n to execute the "
781 "diff ioctl"));
782 } else if (errno == EXDEV) {
783 zfs_error_aux(zhp->zfs_hdl, dgettext(TEXT_DOMAIN,
784 "\n Not an earlier snapshot from the same fs"));
785 } else if (errno != EPIPE || di.zerr == 0) {
786 zfs_error_aux(zhp->zfs_hdl, "%s", strerror(errno));
787 }
788 (void) close(pipefd[1]);
789 (void) pthread_cancel(tid);
790 (void) pthread_join(tid, NULL);
791 teardown_differ_info(&di);
792 if (di.zerr != 0 && di.zerr != EPIPE) {
793 zfs_error_aux(zhp->zfs_hdl, "%s", strerror(di.zerr));
794 return (zfs_error(zhp->zfs_hdl, EZFS_DIFF, di.errbuf));
795 } else {
796 return (zfs_error(zhp->zfs_hdl, EZFS_DIFFDATA, errbuf));
797 }
798 }
799
800 (void) close(pipefd[1]);
801 (void) pthread_join(tid, NULL);
802
803 if (di.zerr != 0) {
804 zfs_error_aux(zhp->zfs_hdl, "%s", strerror(di.zerr));
805 return (zfs_error(zhp->zfs_hdl, EZFS_DIFF, di.errbuf));
806 }
807 teardown_differ_info(&di);
808 return (0);
809 }
810