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 int fobjerr, tobjerr;
247 int change;
248
249 if (dobj == di->shares)
250 return (0);
251
252 /*
253 * Check the from and to snapshots for info on the object. If
254 * we get ENOENT, then the object just didn't exist in that
255 * snapshot. If we get ENOTSUP, then we tried to get
256 * info on a non-ZPL object, which we don't care about anyway.
257 */
258 fobjerr = get_stats_for_obj(di, di->fromsnap, dobj, fobjname,
259 MAXPATHLEN, &fsb);
260 if (fobjerr && di->zerr != ENOENT && di->zerr != ENOTSUP)
261 return (-1);
262
263 tobjerr = get_stats_for_obj(di, di->tosnap, dobj, tobjname,
264 MAXPATHLEN, &tsb);
265 if (tobjerr && di->zerr != ENOENT && di->zerr != ENOTSUP)
266 return (-1);
267
268 /*
269 * Unallocated object sharing the same meta dnode block
270 */
271 if (fobjerr && tobjerr) {
272 ASSERT(di->zerr == ENOENT || di->zerr == ENOTSUP);
273 di->zerr = 0;
274 return (0);
275 }
276
277 di->zerr = 0; /* negate get_stats_for_obj() from side that failed */
278 fmode = fsb.zs_mode & S_IFMT;
279 tmode = tsb.zs_mode & S_IFMT;
280 if (fmode == S_IFDIR || tmode == S_IFDIR || fsb.zs_links == 0 ||
281 tsb.zs_links == 0)
282 change = 0;
283 else
284 change = tsb.zs_links - fsb.zs_links;
285
286 if (fobjerr) {
287 if (change) {
288 print_link_change(fp, di, change, tobjname, &tsb);
289 return (0);
290 }
291 print_file(fp, di, ZDIFF_ADDED, tobjname, &tsb);
292 return (0);
293 } else if (tobjerr) {
294 if (change) {
295 print_link_change(fp, di, change, fobjname, &fsb);
296 return (0);
297 }
298 print_file(fp, di, ZDIFF_REMOVED, fobjname, &fsb);
299 return (0);
300 }
301
302 if (fmode != tmode && fsb.zs_gen == tsb.zs_gen)
303 tsb.zs_gen++; /* Force a generational difference */
304
305 /* Simple modification or no change */
306 if (fsb.zs_gen == tsb.zs_gen) {
307 /* No apparent changes. Could we assert !this? */
308 if (fsb.zs_ctime[0] == tsb.zs_ctime[0] &&
309 fsb.zs_ctime[1] == tsb.zs_ctime[1])
310 return (0);
311 if (change) {
312 print_link_change(fp, di, change,
313 change > 0 ? fobjname : tobjname, &tsb);
314 } else if (strcmp(fobjname, tobjname) == 0) {
315 print_file(fp, di, ZDIFF_MODIFIED, fobjname, &tsb);
316 } else {
317 print_rename(fp, di, fobjname, tobjname, &tsb);
318 }
319 return (0);
320 } else {
321 /* file re-created or object re-used */
322 print_file(fp, di, ZDIFF_REMOVED, fobjname, &fsb);
323 print_file(fp, di, ZDIFF_ADDED, tobjname, &tsb);
324 return (0);
325 }
326 }
327
328 static int
write_inuse_diffs(FILE * fp,differ_info_t * di,dmu_diff_record_t * dr)329 write_inuse_diffs(FILE *fp, differ_info_t *di, dmu_diff_record_t *dr)
330 {
331 uint64_t o;
332 int err;
333
334 for (o = dr->ddr_first; o <= dr->ddr_last; o++) {
335 if ((err = write_inuse_diffs_one(fp, di, o)) != 0)
336 return (err);
337 }
338 return (0);
339 }
340
341 static int
describe_free(FILE * fp,differ_info_t * di,uint64_t object,char * namebuf,int maxlen)342 describe_free(FILE *fp, differ_info_t *di, uint64_t object, char *namebuf,
343 int maxlen)
344 {
345 struct zfs_stat sb;
346
347 if (get_stats_for_obj(di, di->fromsnap, object, namebuf,
348 maxlen, &sb) != 0) {
349 return (-1);
350 }
351 /* Don't print if in the delete queue on from side */
352 if (di->zerr == ESTALE) {
353 di->zerr = 0;
354 return (0);
355 }
356
357 print_file(fp, di, ZDIFF_REMOVED, namebuf, &sb);
358 return (0);
359 }
360
361 static int
write_free_diffs(FILE * fp,differ_info_t * di,dmu_diff_record_t * dr)362 write_free_diffs(FILE *fp, differ_info_t *di, dmu_diff_record_t *dr)
363 {
364 zfs_cmd_t zc = {"\0"};
365 libzfs_handle_t *lhdl = di->zhp->zfs_hdl;
366 char fobjname[MAXPATHLEN];
367
368 (void) strlcpy(zc.zc_name, di->fromsnap, sizeof (zc.zc_name));
369 zc.zc_obj = dr->ddr_first - 1;
370
371 ASSERT(di->zerr == 0);
372
373 while (zc.zc_obj < dr->ddr_last) {
374 int err;
375
376 err = zfs_ioctl(lhdl, ZFS_IOC_NEXT_OBJ, &zc);
377 if (err == 0) {
378 if (zc.zc_obj == di->shares) {
379 zc.zc_obj++;
380 continue;
381 }
382 if (zc.zc_obj > dr->ddr_last) {
383 break;
384 }
385 err = describe_free(fp, di, zc.zc_obj, fobjname,
386 MAXPATHLEN);
387 if (err)
388 break;
389 } else if (errno == ESRCH) {
390 break;
391 } else {
392 (void) snprintf(di->errbuf, sizeof (di->errbuf),
393 dgettext(TEXT_DOMAIN,
394 "next allocated object (> %lld) find failure"),
395 (longlong_t)zc.zc_obj);
396 di->zerr = errno;
397 break;
398 }
399 }
400 if (di->zerr)
401 return (-1);
402 return (0);
403 }
404
405 static void *
differ(void * arg)406 differ(void *arg)
407 {
408 differ_info_t *di = arg;
409 dmu_diff_record_t dr;
410 FILE *ofp;
411 int err = 0;
412
413 if ((ofp = fdopen(di->outputfd, "w")) == NULL) {
414 di->zerr = errno;
415 strlcpy(di->errbuf, strerror(errno), sizeof (di->errbuf));
416 (void) close(di->datafd);
417 return ((void *)-1);
418 }
419
420 for (;;) {
421 char *cp = (char *)&dr;
422 int len = sizeof (dr);
423 int rv;
424
425 do {
426 rv = read(di->datafd, cp, len);
427 cp += rv;
428 len -= rv;
429 } while (len > 0 && rv > 0);
430
431 if (rv < 0 || (rv == 0 && len != sizeof (dr))) {
432 di->zerr = EPIPE;
433 break;
434 } else if (rv == 0) {
435 /* end of file at a natural breaking point */
436 break;
437 }
438
439 switch (dr.ddr_type) {
440 case DDR_FREE:
441 err = write_free_diffs(ofp, di, &dr);
442 break;
443 case DDR_INUSE:
444 err = write_inuse_diffs(ofp, di, &dr);
445 break;
446 default:
447 di->zerr = EPIPE;
448 break;
449 }
450
451 if (err || di->zerr)
452 break;
453 }
454
455 (void) fclose(ofp);
456 (void) close(di->datafd);
457 if (err)
458 return ((void *)-1);
459 if (di->zerr) {
460 ASSERT(di->zerr == EPIPE);
461 (void) snprintf(di->errbuf, sizeof (di->errbuf),
462 dgettext(TEXT_DOMAIN,
463 "Internal error: bad data from diff IOCTL"));
464 return ((void *)-1);
465 }
466 return ((void *)0);
467 }
468
469 static int
make_temp_snapshot(differ_info_t * di)470 make_temp_snapshot(differ_info_t *di)
471 {
472 libzfs_handle_t *hdl = di->zhp->zfs_hdl;
473 zfs_cmd_t zc = {"\0"};
474
475 (void) snprintf(zc.zc_value, sizeof (zc.zc_value),
476 ZDIFF_PREFIX, getpid());
477 (void) strlcpy(zc.zc_name, di->ds, sizeof (zc.zc_name));
478 zc.zc_cleanup_fd = di->cleanupfd;
479
480 if (zfs_ioctl(hdl, ZFS_IOC_TMP_SNAPSHOT, &zc) != 0) {
481 int err = errno;
482 if (err == EPERM) {
483 (void) snprintf(di->errbuf, sizeof (di->errbuf),
484 dgettext(TEXT_DOMAIN, "The diff delegated "
485 "permission is needed in order\nto create a "
486 "just-in-time snapshot for diffing\n"));
487 return (zfs_error(hdl, EZFS_DIFF, di->errbuf));
488 } else {
489 (void) snprintf(di->errbuf, sizeof (di->errbuf),
490 dgettext(TEXT_DOMAIN, "Cannot create just-in-time "
491 "snapshot of '%s'"), zc.zc_name);
492 return (zfs_standard_error(hdl, err, di->errbuf));
493 }
494 }
495
496 di->tmpsnap = zfs_strdup(hdl, zc.zc_value);
497 di->tosnap = zfs_asprintf(hdl, "%s@%s", di->ds, di->tmpsnap);
498 return (0);
499 }
500
501 static void
teardown_differ_info(differ_info_t * di)502 teardown_differ_info(differ_info_t *di)
503 {
504 free(di->ds);
505 free(di->dsmnt);
506 free(di->fromsnap);
507 free(di->frommnt);
508 free(di->tosnap);
509 free(di->tmpsnap);
510 free(di->tomnt);
511 (void) close(di->cleanupfd);
512 }
513
514 static int
get_snapshot_names(differ_info_t * di,const char * fromsnap,const char * tosnap)515 get_snapshot_names(differ_info_t *di, const char *fromsnap,
516 const char *tosnap)
517 {
518 libzfs_handle_t *hdl = di->zhp->zfs_hdl;
519 char *atptrf = NULL;
520 char *atptrt = NULL;
521 int fdslen, fsnlen;
522 int tdslen, tsnlen;
523
524 /*
525 * Can accept
526 * fdslen fsnlen tdslen tsnlen
527 * dataset@snap1
528 * 0. dataset@snap1 dataset@snap2 >0 >1 >0 >1
529 * 1. dataset@snap1 @snap2 >0 >1 ==0 >1
530 * 2. dataset@snap1 dataset >0 >1 >0 ==0
531 * 3. @snap1 dataset@snap2 ==0 >1 >0 >1
532 * 4. @snap1 dataset ==0 >1 >0 ==0
533 */
534 if (tosnap == NULL) {
535 /* only a from snapshot given, must be valid */
536 (void) snprintf(di->errbuf, sizeof (di->errbuf),
537 dgettext(TEXT_DOMAIN,
538 "Badly formed snapshot name %s"), fromsnap);
539
540 if (!zfs_validate_name(hdl, fromsnap, ZFS_TYPE_SNAPSHOT,
541 B_FALSE)) {
542 return (zfs_error(hdl, EZFS_INVALIDNAME,
543 di->errbuf));
544 }
545
546 atptrf = strchr(fromsnap, '@');
547 ASSERT(atptrf != NULL);
548 fdslen = atptrf - fromsnap;
549
550 di->fromsnap = zfs_strdup(hdl, fromsnap);
551 di->ds = zfs_strdup(hdl, fromsnap);
552 di->ds[fdslen] = '\0';
553
554 /* the to snap will be a just-in-time snap of the head */
555 return (make_temp_snapshot(di));
556 }
557
558 (void) snprintf(di->errbuf, sizeof (di->errbuf),
559 dgettext(TEXT_DOMAIN,
560 "Unable to determine which snapshots to compare"));
561
562 atptrf = strchr(fromsnap, '@');
563 atptrt = strchr(tosnap, '@');
564 fdslen = atptrf ? atptrf - fromsnap : strlen(fromsnap);
565 tdslen = atptrt ? atptrt - tosnap : strlen(tosnap);
566 fsnlen = strlen(fromsnap) - fdslen; /* includes @ sign */
567 tsnlen = strlen(tosnap) - tdslen; /* includes @ sign */
568
569 if (fsnlen <= 1 || tsnlen == 1 || (fdslen == 0 && tdslen == 0)) {
570 return (zfs_error(hdl, EZFS_INVALIDNAME, di->errbuf));
571 } else if ((fdslen > 0 && tdslen > 0) &&
572 ((tdslen != fdslen || strncmp(fromsnap, tosnap, fdslen) != 0))) {
573 /*
574 * not the same dataset name, might be okay if
575 * tosnap is a clone of a fromsnap descendant.
576 */
577 char origin[ZFS_MAX_DATASET_NAME_LEN];
578 zprop_source_t src;
579 zfs_handle_t *zhp;
580
581 di->ds = zfs_alloc(di->zhp->zfs_hdl, tdslen + 1);
582 (void) strncpy(di->ds, tosnap, tdslen);
583 di->ds[tdslen] = '\0';
584
585 zhp = zfs_open(hdl, di->ds, ZFS_TYPE_FILESYSTEM);
586 while (zhp != NULL) {
587 if (zfs_prop_get(zhp, ZFS_PROP_ORIGIN, origin,
588 sizeof (origin), &src, NULL, 0, B_FALSE) != 0) {
589 (void) zfs_close(zhp);
590 zhp = NULL;
591 break;
592 }
593 if (strncmp(origin, fromsnap, fsnlen) == 0)
594 break;
595
596 (void) zfs_close(zhp);
597 zhp = zfs_open(hdl, origin, ZFS_TYPE_FILESYSTEM);
598 }
599
600 if (zhp == NULL) {
601 (void) snprintf(di->errbuf, sizeof (di->errbuf),
602 dgettext(TEXT_DOMAIN,
603 "Not an earlier snapshot from the same fs"));
604 return (zfs_error(hdl, EZFS_INVALIDNAME, di->errbuf));
605 } else {
606 (void) zfs_close(zhp);
607 }
608
609 di->isclone = B_TRUE;
610 di->fromsnap = zfs_strdup(hdl, fromsnap);
611 if (tsnlen) {
612 di->tosnap = zfs_strdup(hdl, tosnap);
613 } else {
614 return (make_temp_snapshot(di));
615 }
616 } else {
617 int dslen = fdslen ? fdslen : tdslen;
618
619 di->ds = zfs_alloc(hdl, dslen + 1);
620 (void) strncpy(di->ds, fdslen ? fromsnap : tosnap, dslen);
621 di->ds[dslen] = '\0';
622
623 di->fromsnap = zfs_asprintf(hdl, "%s%s", di->ds, atptrf);
624 if (tsnlen) {
625 di->tosnap = zfs_asprintf(hdl, "%s%s", di->ds, atptrt);
626 } else {
627 return (make_temp_snapshot(di));
628 }
629 }
630 return (0);
631 }
632
633 static int
get_mountpoint(differ_info_t * di,char * dsnm,char ** mntpt)634 get_mountpoint(differ_info_t *di, char *dsnm, char **mntpt)
635 {
636 boolean_t mounted;
637
638 mounted = is_mounted(di->zhp->zfs_hdl, dsnm, mntpt);
639 if (mounted == B_FALSE) {
640 (void) snprintf(di->errbuf, sizeof (di->errbuf),
641 dgettext(TEXT_DOMAIN,
642 "Cannot diff an unmounted snapshot"));
643 return (zfs_error(di->zhp->zfs_hdl, EZFS_BADTYPE, di->errbuf));
644 }
645
646 /* Avoid a double slash at the beginning of root-mounted datasets */
647 if (**mntpt == '/' && *(*mntpt + 1) == '\0')
648 **mntpt = '\0';
649 return (0);
650 }
651
652 static int
get_mountpoints(differ_info_t * di)653 get_mountpoints(differ_info_t *di)
654 {
655 char *strptr;
656 char *frommntpt;
657
658 /*
659 * first get the mountpoint for the parent dataset
660 */
661 if (get_mountpoint(di, di->ds, &di->dsmnt) != 0)
662 return (-1);
663
664 strptr = strchr(di->tosnap, '@');
665 ASSERT3P(strptr, !=, NULL);
666 di->tomnt = zfs_asprintf(di->zhp->zfs_hdl, "%s%s%s", di->dsmnt,
667 ZDIFF_SNAPDIR, ++strptr);
668
669 strptr = strchr(di->fromsnap, '@');
670 ASSERT3P(strptr, !=, NULL);
671
672 frommntpt = di->dsmnt;
673 if (di->isclone) {
674 char *mntpt;
675 int err;
676
677 *strptr = '\0';
678 err = get_mountpoint(di, di->fromsnap, &mntpt);
679 *strptr = '@';
680 if (err != 0)
681 return (-1);
682 frommntpt = mntpt;
683 }
684
685 di->frommnt = zfs_asprintf(di->zhp->zfs_hdl, "%s%s%s", frommntpt,
686 ZDIFF_SNAPDIR, ++strptr);
687
688 if (di->isclone)
689 free(frommntpt);
690
691 return (0);
692 }
693
694 static int
setup_differ_info(zfs_handle_t * zhp,const char * fromsnap,const char * tosnap,differ_info_t * di)695 setup_differ_info(zfs_handle_t *zhp, const char *fromsnap,
696 const char *tosnap, differ_info_t *di)
697 {
698 di->zhp = zhp;
699
700 di->cleanupfd = open(ZFS_DEV, O_RDWR);
701 VERIFY(di->cleanupfd >= 0);
702
703 if (get_snapshot_names(di, fromsnap, tosnap) != 0)
704 return (-1);
705
706 if (get_mountpoints(di) != 0)
707 return (-1);
708
709 if (find_shares_object(di) != 0)
710 return (-1);
711
712 return (0);
713 }
714
715 int
zfs_show_diffs(zfs_handle_t * zhp,int outfd,const char * fromsnap,const char * tosnap,int flags)716 zfs_show_diffs(zfs_handle_t *zhp, int outfd, const char *fromsnap,
717 const char *tosnap, int flags)
718 {
719 zfs_cmd_t zc = {"\0"};
720 char errbuf[1024];
721 differ_info_t di = { 0 };
722 pthread_t tid;
723 int pipefd[2];
724 int iocerr;
725
726 (void) snprintf(errbuf, sizeof (errbuf),
727 dgettext(TEXT_DOMAIN, "zfs diff failed"));
728
729 if (setup_differ_info(zhp, fromsnap, tosnap, &di)) {
730 teardown_differ_info(&di);
731 return (-1);
732 }
733
734 if (pipe(pipefd)) {
735 zfs_error_aux(zhp->zfs_hdl, strerror(errno));
736 teardown_differ_info(&di);
737 return (zfs_error(zhp->zfs_hdl, EZFS_PIPEFAILED, errbuf));
738 }
739
740 di.scripted = (flags & ZFS_DIFF_PARSEABLE);
741 di.classify = (flags & ZFS_DIFF_CLASSIFY);
742 di.timestamped = (flags & ZFS_DIFF_TIMESTAMP);
743
744 di.outputfd = outfd;
745 di.datafd = pipefd[0];
746
747 if (pthread_create(&tid, NULL, differ, &di)) {
748 zfs_error_aux(zhp->zfs_hdl, strerror(errno));
749 (void) close(pipefd[0]);
750 (void) close(pipefd[1]);
751 teardown_differ_info(&di);
752 return (zfs_error(zhp->zfs_hdl,
753 EZFS_THREADCREATEFAILED, errbuf));
754 }
755
756 /* do the ioctl() */
757 (void) strlcpy(zc.zc_value, di.fromsnap, strlen(di.fromsnap) + 1);
758 (void) strlcpy(zc.zc_name, di.tosnap, strlen(di.tosnap) + 1);
759 zc.zc_cookie = pipefd[1];
760
761 iocerr = zfs_ioctl(zhp->zfs_hdl, ZFS_IOC_DIFF, &zc);
762 if (iocerr != 0) {
763 (void) snprintf(errbuf, sizeof (errbuf),
764 dgettext(TEXT_DOMAIN, "Unable to obtain diffs"));
765 if (errno == EPERM) {
766 zfs_error_aux(zhp->zfs_hdl, dgettext(TEXT_DOMAIN,
767 "\n The sys_mount privilege or diff delegated "
768 "permission is needed\n to execute the "
769 "diff ioctl"));
770 } else if (errno == EXDEV) {
771 zfs_error_aux(zhp->zfs_hdl, dgettext(TEXT_DOMAIN,
772 "\n Not an earlier snapshot from the same fs"));
773 } else if (errno != EPIPE || di.zerr == 0) {
774 zfs_error_aux(zhp->zfs_hdl, strerror(errno));
775 }
776 (void) close(pipefd[1]);
777 (void) pthread_cancel(tid);
778 (void) pthread_join(tid, NULL);
779 teardown_differ_info(&di);
780 if (di.zerr != 0 && di.zerr != EPIPE) {
781 zfs_error_aux(zhp->zfs_hdl, strerror(di.zerr));
782 return (zfs_error(zhp->zfs_hdl, EZFS_DIFF, di.errbuf));
783 } else {
784 return (zfs_error(zhp->zfs_hdl, EZFS_DIFFDATA, errbuf));
785 }
786 }
787
788 (void) close(pipefd[1]);
789 (void) pthread_join(tid, NULL);
790
791 if (di.zerr != 0) {
792 zfs_error_aux(zhp->zfs_hdl, strerror(di.zerr));
793 return (zfs_error(zhp->zfs_hdl, EZFS_DIFF, di.errbuf));
794 }
795 teardown_differ_info(&di);
796 return (0);
797 }
798