FreeBSD/Linux Kernel Cross Reference
sys/boot/zfs/zfsimpl.c
1 /*-
2 * Copyright (c) 2007 Doug Rabson
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD: releng/7.3/sys/boot/zfs/zfsimpl.c 200690 2009-12-18 21:02:32Z jhb $");
29
30 /*
31 * Stand-alone ZFS file reader.
32 */
33
34 #include "zfsimpl.h"
35 #include "zfssubr.c"
36
37 /*
38 * List of all vdevs, chained through v_alllink.
39 */
40 static vdev_list_t zfs_vdevs;
41
42 /*
43 * List of all pools, chained through spa_link.
44 */
45 static spa_list_t zfs_pools;
46
47 static uint64_t zfs_crc64_table[256];
48 static const dnode_phys_t *dnode_cache_obj = 0;
49 static uint64_t dnode_cache_bn;
50 static char *dnode_cache_buf;
51 static char *zap_scratch;
52 static char *zfs_temp_buf, *zfs_temp_end, *zfs_temp_ptr;
53
54 #define TEMP_SIZE (1024 * 1024)
55
56 static int zio_read(spa_t *spa, const blkptr_t *bp, void *buf);
57
58 static void
59 zfs_init(void)
60 {
61 STAILQ_INIT(&zfs_vdevs);
62 STAILQ_INIT(&zfs_pools);
63
64 zfs_temp_buf = malloc(TEMP_SIZE);
65 zfs_temp_end = zfs_temp_buf + TEMP_SIZE;
66 zfs_temp_ptr = zfs_temp_buf;
67 dnode_cache_buf = malloc(SPA_MAXBLOCKSIZE);
68 zap_scratch = malloc(SPA_MAXBLOCKSIZE);
69
70 zfs_init_crc();
71 }
72
73 static char *
74 zfs_alloc_temp(size_t sz)
75 {
76 char *p;
77
78 if (zfs_temp_ptr + sz > zfs_temp_end) {
79 printf("ZFS: out of temporary buffer space\n");
80 for (;;) ;
81 }
82 p = zfs_temp_ptr;
83 zfs_temp_ptr += sz;
84
85 return (p);
86 }
87
88 static void
89 zfs_reset_temp(void)
90 {
91
92 zfs_temp_ptr = zfs_temp_buf;
93 }
94
95 static int
96 xdr_int(const unsigned char **xdr, int *ip)
97 {
98 *ip = ((*xdr)[0] << 24)
99 | ((*xdr)[1] << 16)
100 | ((*xdr)[2] << 8)
101 | ((*xdr)[3] << 0);
102 (*xdr) += 4;
103 return (0);
104 }
105
106 static int
107 xdr_u_int(const unsigned char **xdr, u_int *ip)
108 {
109 *ip = ((*xdr)[0] << 24)
110 | ((*xdr)[1] << 16)
111 | ((*xdr)[2] << 8)
112 | ((*xdr)[3] << 0);
113 (*xdr) += 4;
114 return (0);
115 }
116
117 static int
118 xdr_uint64_t(const unsigned char **xdr, uint64_t *lp)
119 {
120 u_int hi, lo;
121
122 xdr_u_int(xdr, &hi);
123 xdr_u_int(xdr, &lo);
124 *lp = (((uint64_t) hi) << 32) | lo;
125 return (0);
126 }
127
128 static int
129 nvlist_find(const unsigned char *nvlist, const char *name, int type,
130 int* elementsp, void *valuep)
131 {
132 const unsigned char *p, *pair;
133 int junk;
134 int encoded_size, decoded_size;
135
136 p = nvlist;
137 xdr_int(&p, &junk);
138 xdr_int(&p, &junk);
139
140 pair = p;
141 xdr_int(&p, &encoded_size);
142 xdr_int(&p, &decoded_size);
143 while (encoded_size && decoded_size) {
144 int namelen, pairtype, elements;
145 const char *pairname;
146
147 xdr_int(&p, &namelen);
148 pairname = (const char*) p;
149 p += roundup(namelen, 4);
150 xdr_int(&p, &pairtype);
151
152 if (!memcmp(name, pairname, namelen) && type == pairtype) {
153 xdr_int(&p, &elements);
154 if (elementsp)
155 *elementsp = elements;
156 if (type == DATA_TYPE_UINT64) {
157 xdr_uint64_t(&p, (uint64_t *) valuep);
158 return (0);
159 } else if (type == DATA_TYPE_STRING) {
160 int len;
161 xdr_int(&p, &len);
162 (*(const char**) valuep) = (const char*) p;
163 return (0);
164 } else if (type == DATA_TYPE_NVLIST
165 || type == DATA_TYPE_NVLIST_ARRAY) {
166 (*(const unsigned char**) valuep) =
167 (const unsigned char*) p;
168 return (0);
169 } else {
170 return (EIO);
171 }
172 } else {
173 /*
174 * Not the pair we are looking for, skip to the next one.
175 */
176 p = pair + encoded_size;
177 }
178
179 pair = p;
180 xdr_int(&p, &encoded_size);
181 xdr_int(&p, &decoded_size);
182 }
183
184 return (EIO);
185 }
186
187 /*
188 * Return the next nvlist in an nvlist array.
189 */
190 static const unsigned char *
191 nvlist_next(const unsigned char *nvlist)
192 {
193 const unsigned char *p, *pair;
194 int junk;
195 int encoded_size, decoded_size;
196
197 p = nvlist;
198 xdr_int(&p, &junk);
199 xdr_int(&p, &junk);
200
201 pair = p;
202 xdr_int(&p, &encoded_size);
203 xdr_int(&p, &decoded_size);
204 while (encoded_size && decoded_size) {
205 p = pair + encoded_size;
206
207 pair = p;
208 xdr_int(&p, &encoded_size);
209 xdr_int(&p, &decoded_size);
210 }
211
212 return p;
213 }
214
215 #ifdef TEST
216
217 static const unsigned char *
218 nvlist_print(const unsigned char *nvlist, unsigned int indent)
219 {
220 static const char* typenames[] = {
221 "DATA_TYPE_UNKNOWN",
222 "DATA_TYPE_BOOLEAN",
223 "DATA_TYPE_BYTE",
224 "DATA_TYPE_INT16",
225 "DATA_TYPE_UINT16",
226 "DATA_TYPE_INT32",
227 "DATA_TYPE_UINT32",
228 "DATA_TYPE_INT64",
229 "DATA_TYPE_UINT64",
230 "DATA_TYPE_STRING",
231 "DATA_TYPE_BYTE_ARRAY",
232 "DATA_TYPE_INT16_ARRAY",
233 "DATA_TYPE_UINT16_ARRAY",
234 "DATA_TYPE_INT32_ARRAY",
235 "DATA_TYPE_UINT32_ARRAY",
236 "DATA_TYPE_INT64_ARRAY",
237 "DATA_TYPE_UINT64_ARRAY",
238 "DATA_TYPE_STRING_ARRAY",
239 "DATA_TYPE_HRTIME",
240 "DATA_TYPE_NVLIST",
241 "DATA_TYPE_NVLIST_ARRAY",
242 "DATA_TYPE_BOOLEAN_VALUE",
243 "DATA_TYPE_INT8",
244 "DATA_TYPE_UINT8",
245 "DATA_TYPE_BOOLEAN_ARRAY",
246 "DATA_TYPE_INT8_ARRAY",
247 "DATA_TYPE_UINT8_ARRAY"
248 };
249
250 unsigned int i, j;
251 const unsigned char *p, *pair;
252 int junk;
253 int encoded_size, decoded_size;
254
255 p = nvlist;
256 xdr_int(&p, &junk);
257 xdr_int(&p, &junk);
258
259 pair = p;
260 xdr_int(&p, &encoded_size);
261 xdr_int(&p, &decoded_size);
262 while (encoded_size && decoded_size) {
263 int namelen, pairtype, elements;
264 const char *pairname;
265
266 xdr_int(&p, &namelen);
267 pairname = (const char*) p;
268 p += roundup(namelen, 4);
269 xdr_int(&p, &pairtype);
270
271 for (i = 0; i < indent; i++)
272 printf(" ");
273 printf("%s %s", typenames[pairtype], pairname);
274
275 xdr_int(&p, &elements);
276 switch (pairtype) {
277 case DATA_TYPE_UINT64: {
278 uint64_t val;
279 xdr_uint64_t(&p, &val);
280 printf(" = 0x%llx\n", val);
281 break;
282 }
283
284 case DATA_TYPE_STRING: {
285 int len;
286 xdr_int(&p, &len);
287 printf(" = \"%s\"\n", p);
288 break;
289 }
290
291 case DATA_TYPE_NVLIST:
292 printf("\n");
293 nvlist_print(p, indent + 1);
294 break;
295
296 case DATA_TYPE_NVLIST_ARRAY:
297 for (j = 0; j < elements; j++) {
298 printf("[%d]\n", j);
299 p = nvlist_print(p, indent + 1);
300 if (j != elements - 1) {
301 for (i = 0; i < indent; i++)
302 printf(" ");
303 printf("%s %s", typenames[pairtype], pairname);
304 }
305 }
306 break;
307
308 default:
309 printf("\n");
310 }
311
312 p = pair + encoded_size;
313
314 pair = p;
315 xdr_int(&p, &encoded_size);
316 xdr_int(&p, &decoded_size);
317 }
318
319 return p;
320 }
321
322 #endif
323
324 static int
325 vdev_read_phys(vdev_t *vdev, const blkptr_t *bp, void *buf,
326 off_t offset, size_t size)
327 {
328 size_t psize;
329 int rc;
330
331 if (bp) {
332 psize = BP_GET_PSIZE(bp);
333 } else {
334 psize = size;
335 }
336
337 /*printf("ZFS: reading %d bytes at 0x%llx to %p\n", psize, offset, buf);*/
338 rc = vdev->v_phys_read(vdev, vdev->v_read_priv, offset, buf, psize);
339 if (rc)
340 return (rc);
341 if (bp && zio_checksum_error(bp, buf))
342 return (EIO);
343
344 return (0);
345 }
346
347 static int
348 vdev_disk_read(vdev_t *vdev, const blkptr_t *bp, void *buf,
349 off_t offset, size_t bytes)
350 {
351
352 return (vdev_read_phys(vdev, bp, buf,
353 offset + VDEV_LABEL_START_SIZE, bytes));
354 }
355
356
357 static int
358 vdev_mirror_read(vdev_t *vdev, const blkptr_t *bp, void *buf,
359 off_t offset, size_t bytes)
360 {
361 vdev_t *kid;
362 int rc;
363
364 rc = EIO;
365 STAILQ_FOREACH(kid, &vdev->v_children, v_childlink) {
366 if (kid->v_state != VDEV_STATE_HEALTHY)
367 continue;
368 rc = kid->v_read(kid, bp, buf, offset, bytes);
369 if (!rc)
370 return (0);
371 }
372
373 return (rc);
374 }
375
376 static vdev_t *
377 vdev_find(uint64_t guid)
378 {
379 vdev_t *vdev;
380
381 STAILQ_FOREACH(vdev, &zfs_vdevs, v_alllink)
382 if (vdev->v_guid == guid)
383 return (vdev);
384
385 return (0);
386 }
387
388 static vdev_t *
389 vdev_create(uint64_t guid, vdev_read_t *read)
390 {
391 vdev_t *vdev;
392
393 vdev = malloc(sizeof(vdev_t));
394 memset(vdev, 0, sizeof(vdev_t));
395 STAILQ_INIT(&vdev->v_children);
396 vdev->v_guid = guid;
397 vdev->v_state = VDEV_STATE_OFFLINE;
398 vdev->v_read = read;
399 vdev->v_phys_read = 0;
400 vdev->v_read_priv = 0;
401 STAILQ_INSERT_TAIL(&zfs_vdevs, vdev, v_alllink);
402
403 return (vdev);
404 }
405
406 static int
407 vdev_init_from_nvlist(const unsigned char *nvlist, vdev_t **vdevp)
408 {
409 int rc;
410 uint64_t guid, id, ashift, nparity;
411 const char *type;
412 const char *path;
413 vdev_t *vdev, *kid;
414 const unsigned char *kids;
415 int nkids, i;
416
417 if (nvlist_find(nvlist, ZPOOL_CONFIG_GUID,
418 DATA_TYPE_UINT64, 0, &guid)
419 || nvlist_find(nvlist, ZPOOL_CONFIG_ID,
420 DATA_TYPE_UINT64, 0, &id)
421 || nvlist_find(nvlist, ZPOOL_CONFIG_TYPE,
422 DATA_TYPE_STRING, 0, &type)) {
423 printf("ZFS: can't find vdev details\n");
424 return (ENOENT);
425 }
426
427 /*
428 * Assume that if we've seen this vdev tree before, this one
429 * will be identical.
430 */
431 vdev = vdev_find(guid);
432 if (vdev) {
433 if (vdevp)
434 *vdevp = vdev;
435 return (0);
436 }
437
438 if (strcmp(type, VDEV_TYPE_MIRROR)
439 && strcmp(type, VDEV_TYPE_DISK)
440 && strcmp(type, VDEV_TYPE_RAIDZ)) {
441 printf("ZFS: can only boot from disk, mirror or raidz vdevs\n");
442 return (EIO);
443 }
444
445 if (!strcmp(type, VDEV_TYPE_MIRROR))
446 vdev = vdev_create(guid, vdev_mirror_read);
447 else if (!strcmp(type, VDEV_TYPE_RAIDZ))
448 vdev = vdev_create(guid, vdev_raidz_read);
449 else
450 vdev = vdev_create(guid, vdev_disk_read);
451
452 vdev->v_id = id;
453 if (nvlist_find(nvlist, ZPOOL_CONFIG_ASHIFT,
454 DATA_TYPE_UINT64, 0, &ashift) == 0)
455 vdev->v_ashift = ashift;
456 else
457 vdev->v_ashift = 0;
458 if (nvlist_find(nvlist, ZPOOL_CONFIG_NPARITY,
459 DATA_TYPE_UINT64, 0, &nparity) == 0)
460 vdev->v_nparity = nparity;
461 else
462 vdev->v_nparity = 0;
463 if (nvlist_find(nvlist, ZPOOL_CONFIG_PATH,
464 DATA_TYPE_STRING, 0, &path) == 0) {
465 if (strlen(path) > 5
466 && path[0] == '/'
467 && path[1] == 'd'
468 && path[2] == 'e'
469 && path[3] == 'v'
470 && path[4] == '/')
471 path += 5;
472 vdev->v_name = strdup(path);
473 } else {
474 if (!strcmp(type, "raidz")) {
475 if (vdev->v_nparity == 1)
476 vdev->v_name = "raidz1";
477 else
478 vdev->v_name = "raidz2";
479 } else {
480 vdev->v_name = strdup(type);
481 }
482 }
483 rc = nvlist_find(nvlist, ZPOOL_CONFIG_CHILDREN,
484 DATA_TYPE_NVLIST_ARRAY, &nkids, &kids);
485 /*
486 * Its ok if we don't have any kids.
487 */
488 if (rc == 0) {
489 vdev->v_nchildren = nkids;
490 for (i = 0; i < nkids; i++) {
491 rc = vdev_init_from_nvlist(kids, &kid);
492 if (rc)
493 return (rc);
494 STAILQ_INSERT_TAIL(&vdev->v_children, kid, v_childlink);
495 kids = nvlist_next(kids);
496 }
497 } else {
498 vdev->v_nchildren = 0;
499 }
500
501 if (vdevp)
502 *vdevp = vdev;
503 return (0);
504 }
505
506 static void
507 vdev_set_state(vdev_t *vdev)
508 {
509 vdev_t *kid;
510 int good_kids;
511 int bad_kids;
512
513 /*
514 * A mirror or raidz is healthy if all its kids are healthy. A
515 * mirror is degraded if any of its kids is healthy; a raidz
516 * is degraded if at most nparity kids are offline.
517 */
518 if (STAILQ_FIRST(&vdev->v_children)) {
519 good_kids = 0;
520 bad_kids = 0;
521 STAILQ_FOREACH(kid, &vdev->v_children, v_childlink) {
522 if (kid->v_state == VDEV_STATE_HEALTHY)
523 good_kids++;
524 else
525 bad_kids++;
526 }
527 if (bad_kids == 0) {
528 vdev->v_state = VDEV_STATE_HEALTHY;
529 } else {
530 if (vdev->v_read == vdev_mirror_read) {
531 if (good_kids) {
532 vdev->v_state = VDEV_STATE_DEGRADED;
533 } else {
534 vdev->v_state = VDEV_STATE_OFFLINE;
535 }
536 } else if (vdev->v_read == vdev_raidz_read) {
537 if (bad_kids > vdev->v_nparity) {
538 vdev->v_state = VDEV_STATE_OFFLINE;
539 } else {
540 vdev->v_state = VDEV_STATE_DEGRADED;
541 }
542 }
543 }
544 }
545 }
546
547 static spa_t *
548 spa_find_by_guid(uint64_t guid)
549 {
550 spa_t *spa;
551
552 STAILQ_FOREACH(spa, &zfs_pools, spa_link)
553 if (spa->spa_guid == guid)
554 return (spa);
555
556 return (0);
557 }
558
559 #ifdef BOOT2
560
561 static spa_t *
562 spa_find_by_name(const char *name)
563 {
564 spa_t *spa;
565
566 STAILQ_FOREACH(spa, &zfs_pools, spa_link)
567 if (!strcmp(spa->spa_name, name))
568 return (spa);
569
570 return (0);
571 }
572
573 #endif
574
575 static spa_t *
576 spa_create(uint64_t guid)
577 {
578 spa_t *spa;
579
580 spa = malloc(sizeof(spa_t));
581 memset(spa, 0, sizeof(spa_t));
582 STAILQ_INIT(&spa->spa_vdevs);
583 spa->spa_guid = guid;
584 STAILQ_INSERT_TAIL(&zfs_pools, spa, spa_link);
585
586 return (spa);
587 }
588
589 static const char *
590 state_name(vdev_state_t state)
591 {
592 static const char* names[] = {
593 "UNKNOWN",
594 "CLOSED",
595 "OFFLINE",
596 "CANT_OPEN",
597 "DEGRADED",
598 "ONLINE"
599 };
600 return names[state];
601 }
602
603 #ifdef BOOT2
604
605 #define pager_printf printf
606
607 #else
608
609 static void
610 pager_printf(const char *fmt, ...)
611 {
612 char line[80];
613 va_list args;
614
615 va_start(args, fmt);
616 vsprintf(line, fmt, args);
617 va_end(args);
618 pager_output(line);
619 }
620
621 #endif
622
623 #define STATUS_FORMAT " %-16s %-10s\n"
624
625 static void
626 print_state(int indent, const char *name, vdev_state_t state)
627 {
628 int i;
629 char buf[512];
630
631 buf[0] = 0;
632 for (i = 0; i < indent; i++)
633 strcat(buf, " ");
634 strcat(buf, name);
635 pager_printf(STATUS_FORMAT, buf, state_name(state));
636
637 }
638
639 static void
640 vdev_status(vdev_t *vdev, int indent)
641 {
642 vdev_t *kid;
643 print_state(indent, vdev->v_name, vdev->v_state);
644
645 STAILQ_FOREACH(kid, &vdev->v_children, v_childlink) {
646 vdev_status(kid, indent + 1);
647 }
648 }
649
650 static void
651 spa_status(spa_t *spa)
652 {
653 vdev_t *vdev;
654 int good_kids, bad_kids, degraded_kids;
655 vdev_state_t state;
656
657 pager_printf(" pool: %s\n", spa->spa_name);
658 pager_printf("config:\n\n");
659 pager_printf(STATUS_FORMAT, "NAME", "STATE");
660
661 good_kids = 0;
662 degraded_kids = 0;
663 bad_kids = 0;
664 STAILQ_FOREACH(vdev, &spa->spa_vdevs, v_childlink) {
665 if (vdev->v_state == VDEV_STATE_HEALTHY)
666 good_kids++;
667 else if (vdev->v_state == VDEV_STATE_DEGRADED)
668 degraded_kids++;
669 else
670 bad_kids++;
671 }
672
673 state = VDEV_STATE_CLOSED;
674 if (good_kids > 0 && (degraded_kids + bad_kids) == 0)
675 state = VDEV_STATE_HEALTHY;
676 else if ((good_kids + degraded_kids) > 0)
677 state = VDEV_STATE_DEGRADED;
678
679 print_state(0, spa->spa_name, state);
680 STAILQ_FOREACH(vdev, &spa->spa_vdevs, v_childlink) {
681 vdev_status(vdev, 1);
682 }
683 }
684
685 static void
686 spa_all_status(void)
687 {
688 spa_t *spa;
689 int first = 1;
690
691 STAILQ_FOREACH(spa, &zfs_pools, spa_link) {
692 if (!first)
693 pager_printf("\n");
694 first = 0;
695 spa_status(spa);
696 }
697 }
698
699 static int
700 vdev_probe(vdev_phys_read_t *read, void *read_priv, spa_t **spap)
701 {
702 vdev_t vtmp;
703 vdev_phys_t *vdev_label = (vdev_phys_t *) zap_scratch;
704 spa_t *spa;
705 vdev_t *vdev, *top_vdev, *pool_vdev;
706 off_t off;
707 blkptr_t bp;
708 const unsigned char *nvlist;
709 uint64_t val;
710 uint64_t guid;
711 uint64_t pool_txg, pool_guid;
712 const char *pool_name;
713 const unsigned char *vdevs;
714 int i, rc;
715 char upbuf[1024];
716 const struct uberblock *up;
717
718 /*
719 * Load the vdev label and figure out which
720 * uberblock is most current.
721 */
722 memset(&vtmp, 0, sizeof(vtmp));
723 vtmp.v_phys_read = read;
724 vtmp.v_read_priv = read_priv;
725 off = offsetof(vdev_label_t, vl_vdev_phys);
726 BP_ZERO(&bp);
727 BP_SET_LSIZE(&bp, sizeof(vdev_phys_t));
728 BP_SET_PSIZE(&bp, sizeof(vdev_phys_t));
729 BP_SET_CHECKSUM(&bp, ZIO_CHECKSUM_LABEL);
730 BP_SET_COMPRESS(&bp, ZIO_COMPRESS_OFF);
731 ZIO_SET_CHECKSUM(&bp.blk_cksum, off, 0, 0, 0);
732 if (vdev_read_phys(&vtmp, &bp, vdev_label, off, 0))
733 return (EIO);
734
735 if (vdev_label->vp_nvlist[0] != NV_ENCODE_XDR) {
736 return (EIO);
737 }
738
739 nvlist = (const unsigned char *) vdev_label->vp_nvlist + 4;
740
741 if (nvlist_find(nvlist,
742 ZPOOL_CONFIG_VERSION,
743 DATA_TYPE_UINT64, 0, &val)) {
744 return (EIO);
745 }
746
747 if (val > SPA_VERSION) {
748 printf("ZFS: unsupported ZFS version %u (should be %u)\n",
749 (unsigned) val, (unsigned) SPA_VERSION);
750 return (EIO);
751 }
752
753 if (nvlist_find(nvlist,
754 ZPOOL_CONFIG_POOL_STATE,
755 DATA_TYPE_UINT64, 0, &val)) {
756 return (EIO);
757 }
758
759 #ifndef TEST
760 if (val != POOL_STATE_ACTIVE) {
761 /*
762 * Don't print a message here. If we happen to reboot
763 * while where is an exported pool around, we don't
764 * need a cascade of confusing messages during boot.
765 */
766 /*printf("ZFS: pool is not active\n");*/
767 return (EIO);
768 }
769 #endif
770
771 if (nvlist_find(nvlist,
772 ZPOOL_CONFIG_POOL_TXG,
773 DATA_TYPE_UINT64, 0, &pool_txg)
774 || nvlist_find(nvlist,
775 ZPOOL_CONFIG_POOL_GUID,
776 DATA_TYPE_UINT64, 0, &pool_guid)
777 || nvlist_find(nvlist,
778 ZPOOL_CONFIG_POOL_NAME,
779 DATA_TYPE_STRING, 0, &pool_name)) {
780 /*
781 * Cache and spare devices end up here - just ignore
782 * them.
783 */
784 /*printf("ZFS: can't find pool details\n");*/
785 return (EIO);
786 }
787
788 /*
789 * Create the pool if this is the first time we've seen it.
790 */
791 spa = spa_find_by_guid(pool_guid);
792 if (!spa) {
793 spa = spa_create(pool_guid);
794 spa->spa_name = strdup(pool_name);
795 }
796 if (pool_txg > spa->spa_txg)
797 spa->spa_txg = pool_txg;
798
799 /*
800 * Get the vdev tree and create our in-core copy of it.
801 * If we already have a healthy vdev with this guid, this must
802 * be some kind of alias (overlapping slices, dangerously dedicated
803 * disks etc).
804 */
805 if (nvlist_find(nvlist,
806 ZPOOL_CONFIG_GUID,
807 DATA_TYPE_UINT64, 0, &guid)) {
808 return (EIO);
809 }
810 vdev = vdev_find(guid);
811 if (vdev && vdev->v_state == VDEV_STATE_HEALTHY) {
812 return (EIO);
813 }
814
815 if (nvlist_find(nvlist,
816 ZPOOL_CONFIG_VDEV_TREE,
817 DATA_TYPE_NVLIST, 0, &vdevs)) {
818 return (EIO);
819 }
820 rc = vdev_init_from_nvlist(vdevs, &top_vdev);
821 if (rc)
822 return (rc);
823
824 /*
825 * Add the toplevel vdev to the pool if its not already there.
826 */
827 STAILQ_FOREACH(pool_vdev, &spa->spa_vdevs, v_childlink)
828 if (top_vdev == pool_vdev)
829 break;
830 if (!pool_vdev && top_vdev)
831 STAILQ_INSERT_TAIL(&spa->spa_vdevs, top_vdev, v_childlink);
832
833 /*
834 * We should already have created an incomplete vdev for this
835 * vdev. Find it and initialise it with our read proc.
836 */
837 vdev = vdev_find(guid);
838 if (vdev) {
839 vdev->v_phys_read = read;
840 vdev->v_read_priv = read_priv;
841 vdev->v_state = VDEV_STATE_HEALTHY;
842 } else {
843 printf("ZFS: inconsistent nvlist contents\n");
844 return (EIO);
845 }
846
847 /*
848 * Re-evaluate top-level vdev state.
849 */
850 vdev_set_state(top_vdev);
851
852 /*
853 * Ok, we are happy with the pool so far. Lets find
854 * the best uberblock and then we can actually access
855 * the contents of the pool.
856 */
857 for (i = 0;
858 i < VDEV_UBERBLOCK_RING >> UBERBLOCK_SHIFT;
859 i++) {
860 off = offsetof(vdev_label_t, vl_uberblock);
861 off += i << UBERBLOCK_SHIFT;
862 BP_ZERO(&bp);
863 DVA_SET_OFFSET(&bp.blk_dva[0], off);
864 BP_SET_LSIZE(&bp, 1 << UBERBLOCK_SHIFT);
865 BP_SET_PSIZE(&bp, 1 << UBERBLOCK_SHIFT);
866 BP_SET_CHECKSUM(&bp, ZIO_CHECKSUM_LABEL);
867 BP_SET_COMPRESS(&bp, ZIO_COMPRESS_OFF);
868 ZIO_SET_CHECKSUM(&bp.blk_cksum, off, 0, 0, 0);
869 if (vdev_read_phys(vdev, &bp, upbuf, off, 0))
870 continue;
871
872 up = (const struct uberblock *) upbuf;
873 if (up->ub_magic != UBERBLOCK_MAGIC)
874 continue;
875 if (up->ub_txg < spa->spa_txg)
876 continue;
877 if (up->ub_txg > spa->spa_uberblock.ub_txg) {
878 spa->spa_uberblock = *up;
879 } else if (up->ub_txg == spa->spa_uberblock.ub_txg) {
880 if (up->ub_timestamp > spa->spa_uberblock.ub_timestamp)
881 spa->spa_uberblock = *up;
882 }
883 }
884
885 if (spap)
886 *spap = spa;
887 return (0);
888 }
889
890 static int
891 ilog2(int n)
892 {
893 int v;
894
895 for (v = 0; v < 32; v++)
896 if (n == (1 << v))
897 return v;
898 return -1;
899 }
900
901 static int
902 zio_read_gang(spa_t *spa, const blkptr_t *bp, const dva_t *dva, void *buf)
903 {
904 zio_gbh_phys_t zio_gb;
905 vdev_t *vdev;
906 int vdevid;
907 off_t offset;
908 int i;
909
910 vdevid = DVA_GET_VDEV(dva);
911 offset = DVA_GET_OFFSET(dva);
912 STAILQ_FOREACH(vdev, &spa->spa_vdevs, v_childlink)
913 if (vdev->v_id == vdevid)
914 break;
915 if (!vdev || !vdev->v_read)
916 return (EIO);
917 if (vdev->v_read(vdev, bp, &zio_gb, offset, SPA_GANGBLOCKSIZE))
918 return (EIO);
919
920 for (i = 0; i < SPA_GBH_NBLKPTRS; i++) {
921 if (zio_read(spa, &zio_gb.zg_blkptr[i], buf))
922 return (EIO);
923 }
924
925 return (0);
926 }
927
928 static int
929 zio_read(spa_t *spa, const blkptr_t *bp, void *buf)
930 {
931 int cpfunc = BP_GET_COMPRESS(bp);
932 size_t lsize = BP_GET_LSIZE(bp);
933 size_t psize = BP_GET_PSIZE(bp);
934 void *pbuf;
935 int i;
936
937 zfs_reset_temp();
938 if (cpfunc != ZIO_COMPRESS_OFF)
939 pbuf = zfs_alloc_temp(psize);
940 else
941 pbuf = buf;
942
943 for (i = 0; i < SPA_DVAS_PER_BP; i++) {
944 const dva_t *dva = &bp->blk_dva[i];
945 vdev_t *vdev;
946 int vdevid;
947 off_t offset;
948
949 if (!dva->dva_word[0] && !dva->dva_word[1])
950 continue;
951
952 if (DVA_GET_GANG(dva)) {
953 printf("ZFS: gang block detected!\n");
954 if (zio_read_gang(spa, bp, dva, buf))
955 return (EIO);
956 } else {
957 vdevid = DVA_GET_VDEV(dva);
958 offset = DVA_GET_OFFSET(dva);
959 STAILQ_FOREACH(vdev, &spa->spa_vdevs, v_childlink)
960 if (vdev->v_id == vdevid)
961 break;
962 if (!vdev || !vdev->v_read) {
963 continue;
964 }
965 if (vdev->v_read(vdev, bp, pbuf, offset, psize))
966 continue;
967
968 if (cpfunc != ZIO_COMPRESS_OFF) {
969 if (zio_decompress_data(cpfunc, pbuf, psize,
970 buf, lsize))
971 return (EIO);
972 }
973 }
974
975 return (0);
976 }
977 printf("ZFS: i/o error - all block copies unavailable\n");
978
979 return (EIO);
980 }
981
982 static int
983 dnode_read(spa_t *spa, const dnode_phys_t *dnode, off_t offset, void *buf, size_t buflen)
984 {
985 int ibshift = dnode->dn_indblkshift - SPA_BLKPTRSHIFT;
986 int bsize = dnode->dn_datablkszsec << SPA_MINBLOCKSHIFT;
987 int nlevels = dnode->dn_nlevels;
988 int i, rc;
989
990 /*
991 * Note: bsize may not be a power of two here so we need to do an
992 * actual divide rather than a bitshift.
993 */
994 while (buflen > 0) {
995 uint64_t bn = offset / bsize;
996 int boff = offset % bsize;
997 int ibn;
998 const blkptr_t *indbp;
999 blkptr_t bp;
1000
1001 if (bn > dnode->dn_maxblkid)
1002 return (EIO);
1003
1004 if (dnode == dnode_cache_obj && bn == dnode_cache_bn)
1005 goto cached;
1006
1007 indbp = dnode->dn_blkptr;
1008 for (i = 0; i < nlevels; i++) {
1009 /*
1010 * Copy the bp from the indirect array so that
1011 * we can re-use the scratch buffer for multi-level
1012 * objects.
1013 */
1014 ibn = bn >> ((nlevels - i - 1) * ibshift);
1015 ibn &= ((1 << ibshift) - 1);
1016 bp = indbp[ibn];
1017 rc = zio_read(spa, &bp, dnode_cache_buf);
1018 if (rc)
1019 return (rc);
1020 indbp = (const blkptr_t *) dnode_cache_buf;
1021 }
1022 dnode_cache_obj = dnode;
1023 dnode_cache_bn = bn;
1024 cached:
1025
1026 /*
1027 * The buffer contains our data block. Copy what we
1028 * need from it and loop.
1029 */
1030 i = bsize - boff;
1031 if (i > buflen) i = buflen;
1032 memcpy(buf, &dnode_cache_buf[boff], i);
1033 buf = ((char*) buf) + i;
1034 offset += i;
1035 buflen -= i;
1036 }
1037
1038 return (0);
1039 }
1040
1041 /*
1042 * Lookup a value in a microzap directory. Assumes that the zap
1043 * scratch buffer contains the directory contents.
1044 */
1045 static int
1046 mzap_lookup(spa_t *spa, const dnode_phys_t *dnode, const char *name, uint64_t *value)
1047 {
1048 const mzap_phys_t *mz;
1049 const mzap_ent_phys_t *mze;
1050 size_t size;
1051 int chunks, i;
1052
1053 /*
1054 * Microzap objects use exactly one block. Read the whole
1055 * thing.
1056 */
1057 size = dnode->dn_datablkszsec * 512;
1058
1059 mz = (const mzap_phys_t *) zap_scratch;
1060 chunks = size / MZAP_ENT_LEN - 1;
1061
1062 for (i = 0; i < chunks; i++) {
1063 mze = &mz->mz_chunk[i];
1064 if (!strcmp(mze->mze_name, name)) {
1065 *value = mze->mze_value;
1066 return (0);
1067 }
1068 }
1069
1070 return (ENOENT);
1071 }
1072
1073 /*
1074 * Compare a name with a zap leaf entry. Return non-zero if the name
1075 * matches.
1076 */
1077 static int
1078 fzap_name_equal(const zap_leaf_t *zl, const zap_leaf_chunk_t *zc, const char *name)
1079 {
1080 size_t namelen;
1081 const zap_leaf_chunk_t *nc;
1082 const char *p;
1083
1084 namelen = zc->l_entry.le_name_length;
1085
1086 nc = &ZAP_LEAF_CHUNK(zl, zc->l_entry.le_name_chunk);
1087 p = name;
1088 while (namelen > 0) {
1089 size_t len;
1090 len = namelen;
1091 if (len > ZAP_LEAF_ARRAY_BYTES)
1092 len = ZAP_LEAF_ARRAY_BYTES;
1093 if (memcmp(p, nc->l_array.la_array, len))
1094 return (0);
1095 p += len;
1096 namelen -= len;
1097 nc = &ZAP_LEAF_CHUNK(zl, nc->l_array.la_next);
1098 }
1099
1100 return 1;
1101 }
1102
1103 /*
1104 * Extract a uint64_t value from a zap leaf entry.
1105 */
1106 static uint64_t
1107 fzap_leaf_value(const zap_leaf_t *zl, const zap_leaf_chunk_t *zc)
1108 {
1109 const zap_leaf_chunk_t *vc;
1110 int i;
1111 uint64_t value;
1112 const uint8_t *p;
1113
1114 vc = &ZAP_LEAF_CHUNK(zl, zc->l_entry.le_value_chunk);
1115 for (i = 0, value = 0, p = vc->l_array.la_array; i < 8; i++) {
1116 value = (value << 8) | p[i];
1117 }
1118
1119 return value;
1120 }
1121
1122 /*
1123 * Lookup a value in a fatzap directory. Assumes that the zap scratch
1124 * buffer contains the directory header.
1125 */
1126 static int
1127 fzap_lookup(spa_t *spa, const dnode_phys_t *dnode, const char *name, uint64_t *value)
1128 {
1129 int bsize = dnode->dn_datablkszsec << SPA_MINBLOCKSHIFT;
1130 zap_phys_t zh = *(zap_phys_t *) zap_scratch;
1131 fat_zap_t z;
1132 uint64_t *ptrtbl;
1133 uint64_t hash;
1134 int rc;
1135
1136 if (zh.zap_magic != ZAP_MAGIC)
1137 return (EIO);
1138
1139 z.zap_block_shift = ilog2(bsize);
1140 z.zap_phys = (zap_phys_t *) zap_scratch;
1141
1142 /*
1143 * Figure out where the pointer table is and read it in if necessary.
1144 */
1145 if (zh.zap_ptrtbl.zt_blk) {
1146 rc = dnode_read(spa, dnode, zh.zap_ptrtbl.zt_blk * bsize,
1147 zap_scratch, bsize);
1148 if (rc)
1149 return (rc);
1150 ptrtbl = (uint64_t *) zap_scratch;
1151 } else {
1152 ptrtbl = &ZAP_EMBEDDED_PTRTBL_ENT(&z, 0);
1153 }
1154
1155 hash = zap_hash(zh.zap_salt, name);
1156
1157 zap_leaf_t zl;
1158 zl.l_bs = z.zap_block_shift;
1159
1160 off_t off = ptrtbl[hash >> (64 - zh.zap_ptrtbl.zt_shift)] << zl.l_bs;
1161 zap_leaf_chunk_t *zc;
1162
1163 rc = dnode_read(spa, dnode, off, zap_scratch, bsize);
1164 if (rc)
1165 return (rc);
1166
1167 zl.l_phys = (zap_leaf_phys_t *) zap_scratch;
1168
1169 /*
1170 * Make sure this chunk matches our hash.
1171 */
1172 if (zl.l_phys->l_hdr.lh_prefix_len > 0
1173 && zl.l_phys->l_hdr.lh_prefix
1174 != hash >> (64 - zl.l_phys->l_hdr.lh_prefix_len))
1175 return (ENOENT);
1176
1177 /*
1178 * Hash within the chunk to find our entry.
1179 */
1180 int shift = (64 - ZAP_LEAF_HASH_SHIFT(&zl) - zl.l_phys->l_hdr.lh_prefix_len);
1181 int h = (hash >> shift) & ((1 << ZAP_LEAF_HASH_SHIFT(&zl)) - 1);
1182 h = zl.l_phys->l_hash[h];
1183 if (h == 0xffff)
1184 return (ENOENT);
1185 zc = &ZAP_LEAF_CHUNK(&zl, h);
1186 while (zc->l_entry.le_hash != hash) {
1187 if (zc->l_entry.le_next == 0xffff) {
1188 zc = 0;
1189 break;
1190 }
1191 zc = &ZAP_LEAF_CHUNK(&zl, zc->l_entry.le_next);
1192 }
1193 if (fzap_name_equal(&zl, zc, name)) {
1194 *value = fzap_leaf_value(&zl, zc);
1195 return (0);
1196 }
1197
1198 return (ENOENT);
1199 }
1200
1201 /*
1202 * Lookup a name in a zap object and return its value as a uint64_t.
1203 */
1204 static int
1205 zap_lookup(spa_t *spa, const dnode_phys_t *dnode, const char *name, uint64_t *value)
1206 {
1207 int rc;
1208 uint64_t zap_type;
1209 size_t size = dnode->dn_datablkszsec * 512;
1210
1211 rc = dnode_read(spa, dnode, 0, zap_scratch, size);
1212 if (rc)
1213 return (rc);
1214
1215 zap_type = *(uint64_t *) zap_scratch;
1216 if (zap_type == ZBT_MICRO)
1217 return mzap_lookup(spa, dnode, name, value);
1218 else
1219 return fzap_lookup(spa, dnode, name, value);
1220 }
1221
1222 #ifdef BOOT2
1223
1224 /*
1225 * List a microzap directory. Assumes that the zap scratch buffer contains
1226 * the directory contents.
1227 */
1228 static int
1229 mzap_list(spa_t *spa, const dnode_phys_t *dnode)
1230 {
1231 const mzap_phys_t *mz;
1232 const mzap_ent_phys_t *mze;
1233 size_t size;
1234 int chunks, i;
1235
1236 /*
1237 * Microzap objects use exactly one block. Read the whole
1238 * thing.
1239 */
1240 size = dnode->dn_datablkszsec * 512;
1241 mz = (const mzap_phys_t *) zap_scratch;
1242 chunks = size / MZAP_ENT_LEN - 1;
1243
1244 for (i = 0; i < chunks; i++) {
1245 mze = &mz->mz_chunk[i];
1246 if (mze->mze_name[0])
1247 //printf("%-32s 0x%llx\n", mze->mze_name, mze->mze_value);
1248 printf("%s\n", mze->mze_name);
1249 }
1250
1251 return (0);
1252 }
1253
1254 /*
1255 * List a fatzap directory. Assumes that the zap scratch buffer contains
1256 * the directory header.
1257 */
1258 static int
1259 fzap_list(spa_t *spa, const dnode_phys_t *dnode)
1260 {
1261 int bsize = dnode->dn_datablkszsec << SPA_MINBLOCKSHIFT;
1262 zap_phys_t zh = *(zap_phys_t *) zap_scratch;
1263 fat_zap_t z;
1264 int i, j;
1265
1266 if (zh.zap_magic != ZAP_MAGIC)
1267 return (EIO);
1268
1269 z.zap_block_shift = ilog2(bsize);
1270 z.zap_phys = (zap_phys_t *) zap_scratch;
1271
1272 /*
1273 * This assumes that the leaf blocks start at block 1. The
1274 * documentation isn't exactly clear on this.
1275 */
1276 zap_leaf_t zl;
1277 zl.l_bs = z.zap_block_shift;
1278 for (i = 0; i < zh.zap_num_leafs; i++) {
1279 off_t off = (i + 1) << zl.l_bs;
1280 char name[256], *p;
1281 uint64_t value;
1282
1283 if (dnode_read(spa, dnode, off, zap_scratch, bsize))
1284 return (EIO);
1285
1286 zl.l_phys = (zap_leaf_phys_t *) zap_scratch;
1287
1288 for (j = 0; j < ZAP_LEAF_NUMCHUNKS(&zl); j++) {
1289 zap_leaf_chunk_t *zc, *nc;
1290 int namelen;
1291
1292 zc = &ZAP_LEAF_CHUNK(&zl, j);
1293 if (zc->l_entry.le_type != ZAP_CHUNK_ENTRY)
1294 continue;
1295 namelen = zc->l_entry.le_name_length;
1296 if (namelen > sizeof(name))
1297 namelen = sizeof(name);
1298
1299 /*
1300 * Paste the name back together.
1301 */
1302 nc = &ZAP_LEAF_CHUNK(&zl, zc->l_entry.le_name_chunk);
1303 p = name;
1304 while (namelen > 0) {
1305 int len;
1306 len = namelen;
1307 if (len > ZAP_LEAF_ARRAY_BYTES)
1308 len = ZAP_LEAF_ARRAY_BYTES;
1309 memcpy(p, nc->l_array.la_array, len);
1310 p += len;
1311 namelen -= len;
1312 nc = &ZAP_LEAF_CHUNK(&zl, nc->l_array.la_next);
1313 }
1314
1315 /*
1316 * Assume the first eight bytes of the value are
1317 * a uint64_t.
1318 */
1319 value = fzap_leaf_value(&zl, zc);
1320
1321 printf("%-32s 0x%llx\n", name, value);
1322 }
1323 }
1324
1325 return (0);
1326 }
1327
1328 /*
1329 * List a zap directory.
1330 */
1331 static int
1332 zap_list(spa_t *spa, const dnode_phys_t *dnode)
1333 {
1334 uint64_t zap_type;
1335 size_t size = dnode->dn_datablkszsec * 512;
1336
1337 if (dnode_read(spa, dnode, 0, zap_scratch, size))
1338 return (EIO);
1339
1340 zap_type = *(uint64_t *) zap_scratch;
1341 if (zap_type == ZBT_MICRO)
1342 return mzap_list(spa, dnode);
1343 else
1344 return fzap_list(spa, dnode);
1345 }
1346
1347 #endif
1348
1349 static int
1350 objset_get_dnode(spa_t *spa, const objset_phys_t *os, uint64_t objnum, dnode_phys_t *dnode)
1351 {
1352 off_t offset;
1353
1354 offset = objnum * sizeof(dnode_phys_t);
1355 return dnode_read(spa, &os->os_meta_dnode, offset,
1356 dnode, sizeof(dnode_phys_t));
1357 }
1358
1359 /*
1360 * Find the object set given the object number of its dataset object
1361 * and return its details in *objset
1362 */
1363 static int
1364 zfs_mount_dataset(spa_t *spa, uint64_t objnum, objset_phys_t *objset)
1365 {
1366 dnode_phys_t dataset;
1367 dsl_dataset_phys_t *ds;
1368
1369 if (objset_get_dnode(spa, &spa->spa_mos, objnum, &dataset)) {
1370 printf("ZFS: can't find dataset %llu\n", objnum);
1371 return (EIO);
1372 }
1373
1374 ds = (dsl_dataset_phys_t *) &dataset.dn_bonus;
1375 if (zio_read(spa, &ds->ds_bp, objset)) {
1376 printf("ZFS: can't read object set for dataset %llu\n", objnum);
1377 return (EIO);
1378 }
1379
1380 return (0);
1381 }
1382
1383 /*
1384 * Find the object set pointed to by the BOOTFS property or the root
1385 * dataset if there is none and return its details in *objset
1386 */
1387 static int
1388 zfs_mount_root(spa_t *spa, objset_phys_t *objset)
1389 {
1390 dnode_phys_t dir, propdir;
1391 uint64_t props, bootfs, root;
1392
1393 /*
1394 * Start with the MOS directory object.
1395 */
1396 if (objset_get_dnode(spa, &spa->spa_mos, DMU_POOL_DIRECTORY_OBJECT, &dir)) {
1397 printf("ZFS: can't read MOS object directory\n");
1398 return (EIO);
1399 }
1400
1401 /*
1402 * Lookup the pool_props and see if we can find a bootfs.
1403 */
1404 if (zap_lookup(spa, &dir, DMU_POOL_PROPS, &props) == 0
1405 && objset_get_dnode(spa, &spa->spa_mos, props, &propdir) == 0
1406 && zap_lookup(spa, &propdir, "bootfs", &bootfs) == 0
1407 && bootfs != 0)
1408 return zfs_mount_dataset(spa, bootfs, objset);
1409
1410 /*
1411 * Lookup the root dataset directory
1412 */
1413 if (zap_lookup(spa, &dir, DMU_POOL_ROOT_DATASET, &root)
1414 || objset_get_dnode(spa, &spa->spa_mos, root, &dir)) {
1415 printf("ZFS: can't find root dsl_dir\n");
1416 return (EIO);
1417 }
1418
1419 /*
1420 * Use the information from the dataset directory's bonus buffer
1421 * to find the dataset object and from that the object set itself.
1422 */
1423 dsl_dir_phys_t *dd = (dsl_dir_phys_t *) &dir.dn_bonus;
1424 return zfs_mount_dataset(spa, dd->dd_head_dataset_obj, objset);
1425 }
1426
1427 static int
1428 zfs_mount_pool(spa_t *spa)
1429 {
1430 /*
1431 * Find the MOS and work our way in from there.
1432 */
1433 if (zio_read(spa, &spa->spa_uberblock.ub_rootbp, &spa->spa_mos)) {
1434 printf("ZFS: can't read MOS\n");
1435 return (EIO);
1436 }
1437
1438 /*
1439 * Find the root object set
1440 */
1441 if (zfs_mount_root(spa, &spa->spa_root_objset)) {
1442 printf("Can't find root filesystem - giving up\n");
1443 return (EIO);
1444 }
1445
1446 return (0);
1447 }
1448
1449 /*
1450 * Lookup a file and return its dnode.
1451 */
1452 static int
1453 zfs_lookup(spa_t *spa, const char *upath, dnode_phys_t *dnode)
1454 {
1455 int rc;
1456 uint64_t objnum, rootnum, parentnum;
1457 dnode_phys_t dn;
1458 const znode_phys_t *zp = (const znode_phys_t *) dn.dn_bonus;
1459 const char *p, *q;
1460 char element[256];
1461 char path[1024];
1462 int symlinks_followed = 0;
1463
1464 if (spa->spa_root_objset.os_type != DMU_OST_ZFS) {
1465 printf("ZFS: unexpected object set type %llu\n",
1466 spa->spa_root_objset.os_type);
1467 return (EIO);
1468 }
1469
1470 /*
1471 * Get the root directory dnode.
1472 */
1473 rc = objset_get_dnode(spa, &spa->spa_root_objset, MASTER_NODE_OBJ, &dn);
1474 if (rc)
1475 return (rc);
1476
1477 rc = zap_lookup(spa, &dn, ZFS_ROOT_OBJ, &rootnum);
1478 if (rc)
1479 return (rc);
1480
1481 rc = objset_get_dnode(spa, &spa->spa_root_objset, rootnum, &dn);
1482 if (rc)
1483 return (rc);
1484
1485 objnum = rootnum;
1486 p = upath;
1487 while (p && *p) {
1488 while (*p == '/')
1489 p++;
1490 if (!*p)
1491 break;
1492 q = strchr(p, '/');
1493 if (q) {
1494 memcpy(element, p, q - p);
1495 element[q - p] = 0;
1496 p = q;
1497 } else {
1498 strcpy(element, p);
1499 p = 0;
1500 }
1501
1502 if ((zp->zp_mode >> 12) != 0x4) {
1503 return (ENOTDIR);
1504 }
1505
1506 parentnum = objnum;
1507 rc = zap_lookup(spa, &dn, element, &objnum);
1508 if (rc)
1509 return (rc);
1510 objnum = ZFS_DIRENT_OBJ(objnum);
1511
1512 rc = objset_get_dnode(spa, &spa->spa_root_objset, objnum, &dn);
1513 if (rc)
1514 return (rc);
1515
1516 /*
1517 * Check for symlink.
1518 */
1519 if ((zp->zp_mode >> 12) == 0xa) {
1520 if (symlinks_followed > 10)
1521 return (EMLINK);
1522 symlinks_followed++;
1523
1524 /*
1525 * Read the link value and copy the tail of our
1526 * current path onto the end.
1527 */
1528 if (p)
1529 strcpy(&path[zp->zp_size], p);
1530 else
1531 path[zp->zp_size] = 0;
1532 if (zp->zp_size + sizeof(znode_phys_t) <= dn.dn_bonuslen) {
1533 memcpy(path, &dn.dn_bonus[sizeof(znode_phys_t)],
1534 zp->zp_size);
1535 } else {
1536 rc = dnode_read(spa, &dn, 0, path, zp->zp_size);
1537 if (rc)
1538 return (rc);
1539 }
1540
1541 /*
1542 * Restart with the new path, starting either at
1543 * the root or at the parent depending whether or
1544 * not the link is relative.
1545 */
1546 p = path;
1547 if (*p == '/')
1548 objnum = rootnum;
1549 else
1550 objnum = parentnum;
1551 objset_get_dnode(spa, &spa->spa_root_objset, objnum, &dn);
1552 }
1553 }
1554
1555 *dnode = dn;
1556 return (0);
1557 }
Cache object: fb64e073079df57076a9a9d9ceec119c
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