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, 2017 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
58 typedef 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 */
82 static int
get_stats_for_obj(differ_info_t * di,const char * dsname,uint64_t obj,char * pn,int maxlen,zfs_stat_t * sb)83 get_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 == ESTALE) {
105 (void) snprintf(pn, maxlen, "(on_delete_queue)");
106 return (0);
107 } else if (di->zerr == EPERM) {
108 (void) snprintf(di->errbuf, sizeof (di->errbuf),
109 dgettext(TEXT_DOMAIN,
110 "The sys_config privilege or diff delegated permission "
111 "is needed\nto discover path names"));
112 return (-1);
113 } else {
114 (void) snprintf(di->errbuf, sizeof (di->errbuf),
115 dgettext(TEXT_DOMAIN,
116 "Unable to determine path or stats for "
117 "object %lld in %s"), obj, dsname);
118 return (-1);
119 }
120 }
121
122 /*
123 * stream_bytes
124 *
125 * Prints a file name out a character at a time. If the character is
126 * not in the range of what we consider "printable" ASCII, display it
127 * as an escaped 3-digit octal value. ASCII values less than a space
128 * are all control characters and we declare the upper end as the
129 * DELete character. This also is the last 7-bit ASCII character.
130 * We choose to treat all 8-bit ASCII as not printable for this
131 * application.
132 */
133 static void
stream_bytes(FILE * fp,const char * string)134 stream_bytes(FILE *fp, const char *string)
135 {
136 char c;
137
138 while ((c = *string++) != '\0') {
139 if (c > ' ' && c != '\\' && c < '\177') {
140 (void) fprintf(fp, "%c", c);
141 } else {
142 (void) fprintf(fp, "\\%03o", (uint8_t)c);
143 }
144 }
145 }
146
147 static void
print_what(FILE * fp,mode_t what)148 print_what(FILE *fp, mode_t what)
149 {
150 char symbol;
151
152 switch (what & S_IFMT) {
153 case S_IFBLK:
154 symbol = 'B';
155 break;
156 case S_IFCHR:
157 symbol = 'C';
158 break;
159 case S_IFDIR:
160 symbol = '/';
161 break;
162 #ifdef S_IFDOOR
163 case S_IFDOOR:
164 symbol = '>';
165 break;
166 #endif
167 case S_IFIFO:
168 symbol = '|';
169 break;
170 case S_IFLNK:
171 symbol = '@';
172 break;
173 #ifdef S_IFPORT
174 case S_IFPORT:
175 symbol = 'P';
176 break;
177 #endif
178 case S_IFSOCK:
179 symbol = '=';
180 break;
181 case S_IFREG:
182 symbol = 'F';
183 break;
184 default:
185 symbol = '?';
186 break;
187 }
188 (void) fprintf(fp, "%c", symbol);
189 }
190
191 static void
print_cmn(FILE * fp,differ_info_t * di,const char * file)192 print_cmn(FILE *fp, differ_info_t *di, const char *file)
193 {
194 stream_bytes(fp, di->dsmnt);
195 stream_bytes(fp, file);
196 }
197
198 static void
print_rename(FILE * fp,differ_info_t * di,const char * old,const char * new,zfs_stat_t * isb)199 print_rename(FILE *fp, differ_info_t *di, const char *old, const char *new,
200 zfs_stat_t *isb)
201 {
202 if (di->timestamped)
203 (void) fprintf(fp, "%10lld.%09lld\t",
204 (longlong_t)isb->zs_ctime[0],
205 (longlong_t)isb->zs_ctime[1]);
206 (void) fprintf(fp, "%c\t", ZDIFF_RENAMED);
207 if (di->classify) {
208 print_what(fp, isb->zs_mode);
209 (void) fprintf(fp, "\t");
210 }
211 print_cmn(fp, di, old);
212 if (di->scripted)
213 (void) fprintf(fp, "\t");
214 else
215 (void) fprintf(fp, " -> ");
216 print_cmn(fp, di, new);
217 (void) fprintf(fp, "\n");
218 }
219
220 static void
print_link_change(FILE * fp,differ_info_t * di,int delta,const char * file,zfs_stat_t * isb)221 print_link_change(FILE *fp, differ_info_t *di, int delta, const char *file,
222 zfs_stat_t *isb)
223 {
224 if (di->timestamped)
225 (void) fprintf(fp, "%10lld.%09lld\t",
226 (longlong_t)isb->zs_ctime[0],
227 (longlong_t)isb->zs_ctime[1]);
228 (void) fprintf(fp, "%c\t", ZDIFF_MODIFIED);
229 if (di->classify) {
230 print_what(fp, isb->zs_mode);
231 (void) fprintf(fp, "\t");
232 }
233 print_cmn(fp, di, file);
234 (void) fprintf(fp, "\t(%+d)", delta);
235 (void) fprintf(fp, "\n");
236 }
237
238 static void
print_file(FILE * fp,differ_info_t * di,char type,const char * file,zfs_stat_t * isb)239 print_file(FILE *fp, differ_info_t *di, char type, const char *file,
240 zfs_stat_t *isb)
241 {
242 if (di->timestamped)
243 (void) fprintf(fp, "%10lld.%09lld\t",
244 (longlong_t)isb->zs_ctime[0],
245 (longlong_t)isb->zs_ctime[1]);
246 (void) fprintf(fp, "%c\t", type);
247 if (di->classify) {
248 print_what(fp, isb->zs_mode);
249 (void) fprintf(fp, "\t");
250 }
251 print_cmn(fp, di, file);
252 (void) fprintf(fp, "\n");
253 }
254
255 static int
write_inuse_diffs_one(FILE * fp,differ_info_t * di,uint64_t dobj)256 write_inuse_diffs_one(FILE *fp, differ_info_t *di, uint64_t dobj)
257 {
258 struct zfs_stat fsb, tsb;
259 mode_t fmode, tmode;
260 char fobjname[MAXPATHLEN], tobjname[MAXPATHLEN];
261 int fobjerr, tobjerr;
262 int change;
263
264 if (dobj == di->shares)
265 return (0);
266
267 /*
268 * Check the from and to snapshots for info on the object. If
269 * we get ENOENT, then the object just didn't exist in that
270 * snapshot. If we get ENOTSUP, then we tried to get
271 * info on a non-ZPL object, which we don't care about anyway.
272 */
273 fobjerr = get_stats_for_obj(di, di->fromsnap, dobj, fobjname,
274 MAXPATHLEN, &fsb);
275 if (fobjerr && di->zerr != ENOENT && di->zerr != ENOTSUP)
276 return (-1);
277
278 tobjerr = get_stats_for_obj(di, di->tosnap, dobj, tobjname,
279 MAXPATHLEN, &tsb);
280 if (tobjerr && di->zerr != ENOENT && di->zerr != ENOTSUP)
281 return (-1);
282
283 /*
284 * Unallocated object sharing the same meta dnode block
285 */
286 if (fobjerr && tobjerr) {
287 ASSERT(di->zerr == ENOENT || di->zerr == ENOTSUP);
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 if (get_stats_for_obj(di, di->fromsnap, object, namebuf,
363 maxlen, &sb) != 0) {
364 /* Let it slide, if in the delete queue on from side */
365 if (di->zerr == ENOENT && sb.zs_links == 0) {
366 di->zerr = 0;
367 return (0);
368 }
369 return (-1);
370 }
371
372 print_file(fp, di, ZDIFF_REMOVED, namebuf, &sb);
373 return (0);
374 }
375
376 static int
write_free_diffs(FILE * fp,differ_info_t * di,dmu_diff_record_t * dr)377 write_free_diffs(FILE *fp, differ_info_t *di, dmu_diff_record_t *dr)
378 {
379 zfs_cmd_t zc = { 0 };
380 libzfs_handle_t *lhdl = di->zhp->zfs_hdl;
381 char fobjname[MAXPATHLEN];
382
383 (void) strlcpy(zc.zc_name, di->fromsnap, sizeof (zc.zc_name));
384 zc.zc_obj = dr->ddr_first - 1;
385
386 ASSERT(di->zerr == 0);
387
388 while (zc.zc_obj < dr->ddr_last) {
389 int err;
390
391 err = ioctl(lhdl->libzfs_fd, ZFS_IOC_NEXT_OBJ, &zc);
392 if (err == 0) {
393 if (zc.zc_obj == di->shares) {
394 zc.zc_obj++;
395 continue;
396 }
397 if (zc.zc_obj > dr->ddr_last) {
398 break;
399 }
400 err = describe_free(fp, di, zc.zc_obj, fobjname,
401 MAXPATHLEN);
402 if (err)
403 break;
404 } else if (errno == ESRCH) {
405 break;
406 } else {
407 (void) snprintf(di->errbuf, sizeof (di->errbuf),
408 dgettext(TEXT_DOMAIN,
409 "next allocated object (> %lld) find failure"),
410 zc.zc_obj);
411 di->zerr = errno;
412 break;
413 }
414 }
415 if (di->zerr)
416 return (-1);
417 return (0);
418 }
419
420 static void *
differ(void * arg)421 differ(void *arg)
422 {
423 differ_info_t *di = arg;
424 dmu_diff_record_t dr;
425 FILE *ofp;
426 int err = 0;
427
428 if ((ofp = fdopen(di->outputfd, "w")) == NULL) {
429 di->zerr = errno;
430 (void) strerror_r(errno, di->errbuf, sizeof (di->errbuf));
431 (void) close(di->datafd);
432 return ((void *)-1);
433 }
434
435 for (;;) {
436 char *cp = (char *)&dr;
437 int len = sizeof (dr);
438 int rv;
439
440 do {
441 rv = read(di->datafd, cp, len);
442 cp += rv;
443 len -= rv;
444 } while (len > 0 && rv > 0);
445
446 if (rv < 0 || (rv == 0 && len != sizeof (dr))) {
447 di->zerr = EPIPE;
448 break;
449 } else if (rv == 0) {
450 /* end of file at a natural breaking point */
451 break;
452 }
453
454 switch (dr.ddr_type) {
455 case DDR_FREE:
456 err = write_free_diffs(ofp, di, &dr);
457 break;
458 case DDR_INUSE:
459 err = write_inuse_diffs(ofp, di, &dr);
460 break;
461 default:
462 di->zerr = EPIPE;
463 break;
464 }
465
466 if (err || di->zerr)
467 break;
468 }
469
470 (void) fclose(ofp);
471 (void) close(di->datafd);
472 if (err)
473 return ((void *)-1);
474 if (di->zerr) {
475 ASSERT(di->zerr == EINVAL);
476 (void) snprintf(di->errbuf, sizeof (di->errbuf),
477 dgettext(TEXT_DOMAIN,
478 "Internal error: bad data from diff IOCTL"));
479 return ((void *)-1);
480 }
481 return ((void *)0);
482 }
483
484 static int
find_shares_object(differ_info_t * di)485 find_shares_object(differ_info_t *di)
486 {
487 char fullpath[MAXPATHLEN];
488 struct stat64 sb = { 0 };
489
490 (void) strlcpy(fullpath, di->dsmnt, MAXPATHLEN);
491 (void) strlcat(fullpath, ZDIFF_SHARESDIR, MAXPATHLEN);
492
493 if (stat64(fullpath, &sb) != 0) {
494 #ifdef illumos
495 (void) snprintf(di->errbuf, sizeof (di->errbuf),
496 dgettext(TEXT_DOMAIN, "Cannot stat %s"), fullpath);
497 return (zfs_error(di->zhp->zfs_hdl, EZFS_DIFF, di->errbuf));
498 #else
499 return (0);
500 #endif
501 }
502
503 di->shares = (uint64_t)sb.st_ino;
504 return (0);
505 }
506
507 static int
make_temp_snapshot(differ_info_t * di)508 make_temp_snapshot(differ_info_t *di)
509 {
510 libzfs_handle_t *hdl = di->zhp->zfs_hdl;
511 zfs_cmd_t zc = { 0 };
512
513 (void) snprintf(zc.zc_value, sizeof (zc.zc_value),
514 ZDIFF_PREFIX, getpid());
515 (void) strlcpy(zc.zc_name, di->ds, sizeof (zc.zc_name));
516 zc.zc_cleanup_fd = di->cleanupfd;
517
518 if (ioctl(hdl->libzfs_fd, ZFS_IOC_TMP_SNAPSHOT, &zc) != 0) {
519 int err = errno;
520 if (err == EPERM) {
521 (void) snprintf(di->errbuf, sizeof (di->errbuf),
522 dgettext(TEXT_DOMAIN, "The diff delegated "
523 "permission is needed in order\nto create a "
524 "just-in-time snapshot for diffing\n"));
525 return (zfs_error(hdl, EZFS_DIFF, di->errbuf));
526 } else {
527 (void) snprintf(di->errbuf, sizeof (di->errbuf),
528 dgettext(TEXT_DOMAIN, "Cannot create just-in-time "
529 "snapshot of '%s'"), zc.zc_name);
530 return (zfs_standard_error(hdl, err, di->errbuf));
531 }
532 }
533
534 di->tmpsnap = zfs_strdup(hdl, zc.zc_value);
535 di->tosnap = zfs_asprintf(hdl, "%s@%s", di->ds, di->tmpsnap);
536 return (0);
537 }
538
539 static void
teardown_differ_info(differ_info_t * di)540 teardown_differ_info(differ_info_t *di)
541 {
542 free(di->ds);
543 free(di->dsmnt);
544 free(di->fromsnap);
545 free(di->frommnt);
546 free(di->tosnap);
547 free(di->tmpsnap);
548 free(di->tomnt);
549 (void) close(di->cleanupfd);
550 }
551
552 static int
get_snapshot_names(differ_info_t * di,const char * fromsnap,const char * tosnap)553 get_snapshot_names(differ_info_t *di, const char *fromsnap,
554 const char *tosnap)
555 {
556 libzfs_handle_t *hdl = di->zhp->zfs_hdl;
557 char *atptrf = NULL;
558 char *atptrt = NULL;
559 int fdslen, fsnlen;
560 int tdslen, tsnlen;
561
562 /*
563 * Can accept
564 * dataset@snap1
565 * dataset@snap1 dataset@snap2
566 * dataset@snap1 @snap2
567 * dataset@snap1 dataset
568 * @snap1 dataset@snap2
569 */
570 if (tosnap == NULL) {
571 /* only a from snapshot given, must be valid */
572 (void) snprintf(di->errbuf, sizeof (di->errbuf),
573 dgettext(TEXT_DOMAIN,
574 "Badly formed snapshot name %s"), fromsnap);
575
576 if (!zfs_validate_name(hdl, fromsnap, ZFS_TYPE_SNAPSHOT,
577 B_FALSE)) {
578 return (zfs_error(hdl, EZFS_INVALIDNAME,
579 di->errbuf));
580 }
581
582 atptrf = strchr(fromsnap, '@');
583 ASSERT(atptrf != NULL);
584 fdslen = atptrf - fromsnap;
585
586 di->fromsnap = zfs_strdup(hdl, fromsnap);
587 di->ds = zfs_strdup(hdl, fromsnap);
588 di->ds[fdslen] = '\0';
589
590 /* the to snap will be a just-in-time snap of the head */
591 return (make_temp_snapshot(di));
592 }
593
594 (void) snprintf(di->errbuf, sizeof (di->errbuf),
595 dgettext(TEXT_DOMAIN,
596 "Unable to determine which snapshots to compare"));
597
598 atptrf = strchr(fromsnap, '@');
599 atptrt = strchr(tosnap, '@');
600 fdslen = atptrf ? atptrf - fromsnap : strlen(fromsnap);
601 tdslen = atptrt ? atptrt - tosnap : strlen(tosnap);
602 fsnlen = strlen(fromsnap) - fdslen; /* includes @ sign */
603 tsnlen = strlen(tosnap) - tdslen; /* includes @ sign */
604
605 if (fsnlen <= 1 || tsnlen == 1 || (fdslen == 0 && tdslen == 0) ||
606 (fsnlen == 0 && tsnlen == 0)) {
607 return (zfs_error(hdl, EZFS_INVALIDNAME, di->errbuf));
608 } else if ((fdslen > 0 && tdslen > 0) &&
609 ((tdslen != fdslen || strncmp(fromsnap, tosnap, fdslen) != 0))) {
610 /*
611 * not the same dataset name, might be okay if
612 * tosnap is a clone of a fromsnap descendant.
613 */
614 char origin[ZFS_MAX_DATASET_NAME_LEN];
615 zprop_source_t src;
616 zfs_handle_t *zhp;
617
618 di->ds = zfs_alloc(di->zhp->zfs_hdl, tdslen + 1);
619 (void) strncpy(di->ds, tosnap, tdslen);
620 di->ds[tdslen] = '\0';
621
622 zhp = zfs_open(hdl, di->ds, ZFS_TYPE_FILESYSTEM);
623 while (zhp != NULL) {
624 if (zfs_prop_get(zhp, ZFS_PROP_ORIGIN, origin,
625 sizeof (origin), &src, NULL, 0, B_FALSE) != 0) {
626 (void) zfs_close(zhp);
627 zhp = NULL;
628 break;
629 }
630 if (strncmp(origin, fromsnap, fsnlen) == 0)
631 break;
632
633 (void) zfs_close(zhp);
634 zhp = zfs_open(hdl, origin, ZFS_TYPE_FILESYSTEM);
635 }
636
637 if (zhp == NULL) {
638 (void) snprintf(di->errbuf, sizeof (di->errbuf),
639 dgettext(TEXT_DOMAIN,
640 "Not an earlier snapshot from the same fs"));
641 return (zfs_error(hdl, EZFS_INVALIDNAME, di->errbuf));
642 } else {
643 (void) zfs_close(zhp);
644 }
645
646 di->isclone = B_TRUE;
647 di->fromsnap = zfs_strdup(hdl, fromsnap);
648 if (tsnlen) {
649 di->tosnap = zfs_strdup(hdl, tosnap);
650 } else {
651 return (make_temp_snapshot(di));
652 }
653 } else {
654 int dslen = fdslen ? fdslen : tdslen;
655
656 di->ds = zfs_alloc(hdl, dslen + 1);
657 (void) strncpy(di->ds, fdslen ? fromsnap : tosnap, dslen);
658 di->ds[dslen] = '\0';
659
660 di->fromsnap = zfs_asprintf(hdl, "%s%s", di->ds, atptrf);
661 if (tsnlen) {
662 di->tosnap = zfs_asprintf(hdl, "%s%s", di->ds, atptrt);
663 } else {
664 return (make_temp_snapshot(di));
665 }
666 }
667 return (0);
668 }
669
670 static int
get_mountpoint(differ_info_t * di,char * dsnm,char ** mntpt)671 get_mountpoint(differ_info_t *di, char *dsnm, char **mntpt)
672 {
673 boolean_t mounted;
674
675 mounted = is_mounted(di->zhp->zfs_hdl, dsnm, mntpt);
676 if (mounted == B_FALSE) {
677 (void) snprintf(di->errbuf, sizeof (di->errbuf),
678 dgettext(TEXT_DOMAIN,
679 "Cannot diff an unmounted snapshot"));
680 return (zfs_error(di->zhp->zfs_hdl, EZFS_BADTYPE, di->errbuf));
681 }
682
683 /* Avoid a double slash at the beginning of root-mounted datasets */
684 if (**mntpt == '/' && *(*mntpt + 1) == '\0')
685 **mntpt = '\0';
686 return (0);
687 }
688
689 static int
get_mountpoints(differ_info_t * di)690 get_mountpoints(differ_info_t *di)
691 {
692 char *strptr;
693 char *frommntpt;
694
695 /*
696 * first get the mountpoint for the parent dataset
697 */
698 if (get_mountpoint(di, di->ds, &di->dsmnt) != 0)
699 return (-1);
700
701 strptr = strchr(di->tosnap, '@');
702 ASSERT3P(strptr, !=, NULL);
703 di->tomnt = zfs_asprintf(di->zhp->zfs_hdl, "%s%s%s", di->dsmnt,
704 ZDIFF_SNAPDIR, ++strptr);
705
706 strptr = strchr(di->fromsnap, '@');
707 ASSERT3P(strptr, !=, NULL);
708
709 frommntpt = di->dsmnt;
710 if (di->isclone) {
711 char *mntpt;
712 int err;
713
714 *strptr = '\0';
715 err = get_mountpoint(di, di->fromsnap, &mntpt);
716 *strptr = '@';
717 if (err != 0)
718 return (-1);
719 frommntpt = mntpt;
720 }
721
722 di->frommnt = zfs_asprintf(di->zhp->zfs_hdl, "%s%s%s", frommntpt,
723 ZDIFF_SNAPDIR, ++strptr);
724
725 if (di->isclone)
726 free(frommntpt);
727
728 return (0);
729 }
730
731 static int
setup_differ_info(zfs_handle_t * zhp,const char * fromsnap,const char * tosnap,differ_info_t * di)732 setup_differ_info(zfs_handle_t *zhp, const char *fromsnap,
733 const char *tosnap, differ_info_t *di)
734 {
735 di->zhp = zhp;
736
737 di->cleanupfd = open(ZFS_DEV, O_RDWR|O_EXCL);
738 VERIFY(di->cleanupfd >= 0);
739
740 if (get_snapshot_names(di, fromsnap, tosnap) != 0)
741 return (-1);
742
743 if (get_mountpoints(di) != 0)
744 return (-1);
745
746 if (find_shares_object(di) != 0)
747 return (-1);
748
749 return (0);
750 }
751
752 int
zfs_show_diffs(zfs_handle_t * zhp,int outfd,const char * fromsnap,const char * tosnap,int flags)753 zfs_show_diffs(zfs_handle_t *zhp, int outfd, const char *fromsnap,
754 const char *tosnap, int flags)
755 {
756 zfs_cmd_t zc = { 0 };
757 char errbuf[1024];
758 differ_info_t di = { 0 };
759 pthread_t tid;
760 int pipefd[2];
761 int iocerr;
762
763 (void) snprintf(errbuf, sizeof (errbuf),
764 dgettext(TEXT_DOMAIN, "zfs diff failed"));
765
766 if (setup_differ_info(zhp, fromsnap, tosnap, &di)) {
767 teardown_differ_info(&di);
768 return (-1);
769 }
770
771 if (pipe(pipefd)) {
772 zfs_error_aux(zhp->zfs_hdl, strerror(errno));
773 teardown_differ_info(&di);
774 return (zfs_error(zhp->zfs_hdl, EZFS_PIPEFAILED, errbuf));
775 }
776
777 di.scripted = (flags & ZFS_DIFF_PARSEABLE);
778 di.classify = (flags & ZFS_DIFF_CLASSIFY);
779 di.timestamped = (flags & ZFS_DIFF_TIMESTAMP);
780
781 di.outputfd = outfd;
782 di.datafd = pipefd[0];
783
784 if (pthread_create(&tid, NULL, differ, &di)) {
785 zfs_error_aux(zhp->zfs_hdl, strerror(errno));
786 (void) close(pipefd[0]);
787 (void) close(pipefd[1]);
788 teardown_differ_info(&di);
789 return (zfs_error(zhp->zfs_hdl,
790 EZFS_THREADCREATEFAILED, errbuf));
791 }
792
793 /* do the ioctl() */
794 (void) strlcpy(zc.zc_value, di.fromsnap, strlen(di.fromsnap) + 1);
795 (void) strlcpy(zc.zc_name, di.tosnap, strlen(di.tosnap) + 1);
796 zc.zc_cookie = pipefd[1];
797
798 iocerr = ioctl(zhp->zfs_hdl->libzfs_fd, ZFS_IOC_DIFF, &zc);
799 if (iocerr != 0) {
800 (void) snprintf(errbuf, sizeof (errbuf),
801 dgettext(TEXT_DOMAIN, "Unable to obtain diffs"));
802 if (errno == EPERM) {
803 zfs_error_aux(zhp->zfs_hdl, dgettext(TEXT_DOMAIN,
804 "\n The sys_mount privilege or diff delegated "
805 "permission is needed\n to execute the "
806 "diff ioctl"));
807 } else if (errno == EXDEV) {
808 zfs_error_aux(zhp->zfs_hdl, dgettext(TEXT_DOMAIN,
809 "\n Not an earlier snapshot from the same fs"));
810 } else if (errno != EPIPE || di.zerr == 0) {
811 zfs_error_aux(zhp->zfs_hdl, strerror(errno));
812 }
813 (void) close(pipefd[1]);
814 (void) pthread_cancel(tid);
815 (void) pthread_join(tid, NULL);
816 teardown_differ_info(&di);
817 if (di.zerr != 0 && di.zerr != EPIPE) {
818 zfs_error_aux(zhp->zfs_hdl, strerror(di.zerr));
819 return (zfs_error(zhp->zfs_hdl, EZFS_DIFF, di.errbuf));
820 } else {
821 return (zfs_error(zhp->zfs_hdl, EZFS_DIFFDATA, errbuf));
822 }
823 }
824
825 (void) close(pipefd[1]);
826 (void) pthread_join(tid, NULL);
827
828 if (di.zerr != 0) {
829 zfs_error_aux(zhp->zfs_hdl, strerror(di.zerr));
830 return (zfs_error(zhp->zfs_hdl, EZFS_DIFF, di.errbuf));
831 }
832 teardown_differ_info(&di);
833 return (0);
834 }
835