The Design and Implementation of the FreeBSD Operating System, Second Edition
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FreeBSD/Linux Kernel Cross Reference
sys/boot/zfs/zfsimpl.c

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    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/11.0/sys/boot/zfs/zfsimpl.c 294040 2016-01-14 21:31:26Z smh $");
   29 
   30 /*
   31  *      Stand-alone ZFS file reader.
   32  */
   33 
   34 #include <sys/stat.h>
   35 #include <sys/stdint.h>
   36 
   37 #include "zfsimpl.h"
   38 #include "zfssubr.c"
   39 
   40 
   41 struct zfsmount {
   42         const spa_t     *spa;
   43         objset_phys_t   objset;
   44         uint64_t        rootobj;
   45 };
   46 
   47 /*
   48  * List of all vdevs, chained through v_alllink.
   49  */
   50 static vdev_list_t zfs_vdevs;
   51 
   52  /*
   53  * List of ZFS features supported for read
   54  */
   55 static const char *features_for_read[] = {
   56         "org.illumos:lz4_compress",
   57         "com.delphix:hole_birth",
   58         "com.delphix:extensible_dataset",
   59         "com.delphix:embedded_data",
   60         "org.open-zfs:large_blocks",
   61         NULL
   62 };
   63 
   64 /*
   65  * List of all pools, chained through spa_link.
   66  */
   67 static spa_list_t zfs_pools;
   68 
   69 static uint64_t zfs_crc64_table[256];
   70 static const dnode_phys_t *dnode_cache_obj = 0;
   71 static uint64_t dnode_cache_bn;
   72 static char *dnode_cache_buf;
   73 static char *zap_scratch;
   74 static char *zfs_temp_buf, *zfs_temp_end, *zfs_temp_ptr;
   75 
   76 #define TEMP_SIZE       (1024 * 1024)
   77 
   78 static int zio_read(const spa_t *spa, const blkptr_t *bp, void *buf);
   79 static int zfs_get_root(const spa_t *spa, uint64_t *objid);
   80 static int zfs_rlookup(const spa_t *spa, uint64_t objnum, char *result);
   81 
   82 static void
   83 zfs_init(void)
   84 {
   85         STAILQ_INIT(&zfs_vdevs);
   86         STAILQ_INIT(&zfs_pools);
   87 
   88         zfs_temp_buf = malloc(TEMP_SIZE);
   89         zfs_temp_end = zfs_temp_buf + TEMP_SIZE;
   90         zfs_temp_ptr = zfs_temp_buf;
   91         dnode_cache_buf = malloc(SPA_MAXBLOCKSIZE);
   92         zap_scratch = malloc(SPA_MAXBLOCKSIZE);
   93 
   94         zfs_init_crc();
   95 }
   96 
   97 static void *
   98 zfs_alloc(size_t size)
   99 {
  100         char *ptr;
  101 
  102         if (zfs_temp_ptr + size > zfs_temp_end) {
  103                 printf("ZFS: out of temporary buffer space\n");
  104                 for (;;) ;
  105         }
  106         ptr = zfs_temp_ptr;
  107         zfs_temp_ptr += size;
  108 
  109         return (ptr);
  110 }
  111 
  112 static void
  113 zfs_free(void *ptr, size_t size)
  114 {
  115 
  116         zfs_temp_ptr -= size;
  117         if (zfs_temp_ptr != ptr) {
  118                 printf("ZFS: zfs_alloc()/zfs_free() mismatch\n");
  119                 for (;;) ;
  120         }
  121 }
  122 
  123 static int
  124 xdr_int(const unsigned char **xdr, int *ip)
  125 {
  126         *ip = ((*xdr)[0] << 24)
  127                 | ((*xdr)[1] << 16)
  128                 | ((*xdr)[2] << 8)
  129                 | ((*xdr)[3] << 0);
  130         (*xdr) += 4;
  131         return (0);
  132 }
  133 
  134 static int
  135 xdr_u_int(const unsigned char **xdr, u_int *ip)
  136 {
  137         *ip = ((*xdr)[0] << 24)
  138                 | ((*xdr)[1] << 16)
  139                 | ((*xdr)[2] << 8)
  140                 | ((*xdr)[3] << 0);
  141         (*xdr) += 4;
  142         return (0);
  143 }
  144 
  145 static int
  146 xdr_uint64_t(const unsigned char **xdr, uint64_t *lp)
  147 {
  148         u_int hi, lo;
  149 
  150         xdr_u_int(xdr, &hi);
  151         xdr_u_int(xdr, &lo);
  152         *lp = (((uint64_t) hi) << 32) | lo;
  153         return (0);
  154 }
  155 
  156 static int
  157 nvlist_find(const unsigned char *nvlist, const char *name, int type,
  158             int* elementsp, void *valuep)
  159 {
  160         const unsigned char *p, *pair;
  161         int junk;
  162         int encoded_size, decoded_size;
  163 
  164         p = nvlist;
  165         xdr_int(&p, &junk);
  166         xdr_int(&p, &junk);
  167 
  168         pair = p;
  169         xdr_int(&p, &encoded_size);
  170         xdr_int(&p, &decoded_size);
  171         while (encoded_size && decoded_size) {
  172                 int namelen, pairtype, elements;
  173                 const char *pairname;
  174 
  175                 xdr_int(&p, &namelen);
  176                 pairname = (const char*) p;
  177                 p += roundup(namelen, 4);
  178                 xdr_int(&p, &pairtype);
  179 
  180                 if (!memcmp(name, pairname, namelen) && type == pairtype) {
  181                         xdr_int(&p, &elements);
  182                         if (elementsp)
  183                                 *elementsp = elements;
  184                         if (type == DATA_TYPE_UINT64) {
  185                                 xdr_uint64_t(&p, (uint64_t *) valuep);
  186                                 return (0);
  187                         } else if (type == DATA_TYPE_STRING) {
  188                                 int len;
  189                                 xdr_int(&p, &len);
  190                                 (*(const char**) valuep) = (const char*) p;
  191                                 return (0);
  192                         } else if (type == DATA_TYPE_NVLIST
  193                                    || type == DATA_TYPE_NVLIST_ARRAY) {
  194                                 (*(const unsigned char**) valuep) =
  195                                          (const unsigned char*) p;
  196                                 return (0);
  197                         } else {
  198                                 return (EIO);
  199                         }
  200                 } else {
  201                         /*
  202                          * Not the pair we are looking for, skip to the next one.
  203                          */
  204                         p = pair + encoded_size;
  205                 }
  206 
  207                 pair = p;
  208                 xdr_int(&p, &encoded_size);
  209                 xdr_int(&p, &decoded_size);
  210         }
  211 
  212         return (EIO);
  213 }
  214 
  215 static int
  216 nvlist_check_features_for_read(const unsigned char *nvlist)
  217 {
  218         const unsigned char *p, *pair;
  219         int junk;
  220         int encoded_size, decoded_size;
  221         int rc;
  222 
  223         rc = 0;
  224 
  225         p = nvlist;
  226         xdr_int(&p, &junk);
  227         xdr_int(&p, &junk);
  228 
  229         pair = p;
  230         xdr_int(&p, &encoded_size);
  231         xdr_int(&p, &decoded_size);
  232         while (encoded_size && decoded_size) {
  233                 int namelen, pairtype;
  234                 const char *pairname;
  235                 int i, found;
  236 
  237                 found = 0;
  238 
  239                 xdr_int(&p, &namelen);
  240                 pairname = (const char*) p;
  241                 p += roundup(namelen, 4);
  242                 xdr_int(&p, &pairtype);
  243 
  244                 for (i = 0; features_for_read[i] != NULL; i++) {
  245                         if (!memcmp(pairname, features_for_read[i], namelen)) {
  246                                 found = 1;
  247                                 break;
  248                         }
  249                 }
  250 
  251                 if (!found) {
  252                         printf("ZFS: unsupported feature: %s\n", pairname);
  253                         rc = EIO;
  254                 }
  255 
  256                 p = pair + encoded_size;
  257 
  258                 pair = p;
  259                 xdr_int(&p, &encoded_size);
  260                 xdr_int(&p, &decoded_size);
  261         }
  262 
  263         return (rc);
  264 }
  265 
  266 /*
  267  * Return the next nvlist in an nvlist array.
  268  */
  269 static const unsigned char *
  270 nvlist_next(const unsigned char *nvlist)
  271 {
  272         const unsigned char *p, *pair;
  273         int junk;
  274         int encoded_size, decoded_size;
  275 
  276         p = nvlist;
  277         xdr_int(&p, &junk);
  278         xdr_int(&p, &junk);
  279 
  280         pair = p;
  281         xdr_int(&p, &encoded_size);
  282         xdr_int(&p, &decoded_size);
  283         while (encoded_size && decoded_size) {
  284                 p = pair + encoded_size;
  285 
  286                 pair = p;
  287                 xdr_int(&p, &encoded_size);
  288                 xdr_int(&p, &decoded_size);
  289         }
  290 
  291         return p;
  292 }
  293 
  294 #ifdef TEST
  295 
  296 static const unsigned char *
  297 nvlist_print(const unsigned char *nvlist, unsigned int indent)
  298 {
  299         static const char* typenames[] = {
  300                 "DATA_TYPE_UNKNOWN",
  301                 "DATA_TYPE_BOOLEAN",
  302                 "DATA_TYPE_BYTE",
  303                 "DATA_TYPE_INT16",
  304                 "DATA_TYPE_UINT16",
  305                 "DATA_TYPE_INT32",
  306                 "DATA_TYPE_UINT32",
  307                 "DATA_TYPE_INT64",
  308                 "DATA_TYPE_UINT64",
  309                 "DATA_TYPE_STRING",
  310                 "DATA_TYPE_BYTE_ARRAY",
  311                 "DATA_TYPE_INT16_ARRAY",
  312                 "DATA_TYPE_UINT16_ARRAY",
  313                 "DATA_TYPE_INT32_ARRAY",
  314                 "DATA_TYPE_UINT32_ARRAY",
  315                 "DATA_TYPE_INT64_ARRAY",
  316                 "DATA_TYPE_UINT64_ARRAY",
  317                 "DATA_TYPE_STRING_ARRAY",
  318                 "DATA_TYPE_HRTIME",
  319                 "DATA_TYPE_NVLIST",
  320                 "DATA_TYPE_NVLIST_ARRAY",
  321                 "DATA_TYPE_BOOLEAN_VALUE",
  322                 "DATA_TYPE_INT8",
  323                 "DATA_TYPE_UINT8",
  324                 "DATA_TYPE_BOOLEAN_ARRAY",
  325                 "DATA_TYPE_INT8_ARRAY",
  326                 "DATA_TYPE_UINT8_ARRAY"
  327         };
  328 
  329         unsigned int i, j;
  330         const unsigned char *p, *pair;
  331         int junk;
  332         int encoded_size, decoded_size;
  333 
  334         p = nvlist;
  335         xdr_int(&p, &junk);
  336         xdr_int(&p, &junk);
  337 
  338         pair = p;
  339         xdr_int(&p, &encoded_size);
  340         xdr_int(&p, &decoded_size);
  341         while (encoded_size && decoded_size) {
  342                 int namelen, pairtype, elements;
  343                 const char *pairname;
  344 
  345                 xdr_int(&p, &namelen);
  346                 pairname = (const char*) p;
  347                 p += roundup(namelen, 4);
  348                 xdr_int(&p, &pairtype);
  349 
  350                 for (i = 0; i < indent; i++)
  351                         printf(" ");
  352                 printf("%s %s", typenames[pairtype], pairname);
  353 
  354                 xdr_int(&p, &elements);
  355                 switch (pairtype) {
  356                 case DATA_TYPE_UINT64: {
  357                         uint64_t val;
  358                         xdr_uint64_t(&p, &val);
  359                         printf(" = 0x%jx\n", (uintmax_t)val);
  360                         break;
  361                 }
  362 
  363                 case DATA_TYPE_STRING: {
  364                         int len;
  365                         xdr_int(&p, &len);
  366                         printf(" = \"%s\"\n", p);
  367                         break;
  368                 }
  369 
  370                 case DATA_TYPE_NVLIST:
  371                         printf("\n");
  372                         nvlist_print(p, indent + 1);
  373                         break;
  374 
  375                 case DATA_TYPE_NVLIST_ARRAY:
  376                         for (j = 0; j < elements; j++) {
  377                                 printf("[%d]\n", j);
  378                                 p = nvlist_print(p, indent + 1);
  379                                 if (j != elements - 1) {
  380                                         for (i = 0; i < indent; i++)
  381                                                 printf(" ");
  382                                         printf("%s %s", typenames[pairtype], pairname);
  383                                 }
  384                         }
  385                         break;
  386 
  387                 default:
  388                         printf("\n");
  389                 }
  390 
  391                 p = pair + encoded_size;
  392 
  393                 pair = p;
  394                 xdr_int(&p, &encoded_size);
  395                 xdr_int(&p, &decoded_size);
  396         }
  397 
  398         return p;
  399 }
  400 
  401 #endif
  402 
  403 static int
  404 vdev_read_phys(vdev_t *vdev, const blkptr_t *bp, void *buf,
  405     off_t offset, size_t size)
  406 {
  407         size_t psize;
  408         int rc;
  409 
  410         if (!vdev->v_phys_read)
  411                 return (EIO);
  412 
  413         if (bp) {
  414                 psize = BP_GET_PSIZE(bp);
  415         } else {
  416                 psize = size;
  417         }
  418 
  419         /*printf("ZFS: reading %d bytes at 0x%jx to %p\n", psize, (uintmax_t)offset, buf);*/
  420         rc = vdev->v_phys_read(vdev, vdev->v_read_priv, offset, buf, psize);
  421         if (rc)
  422                 return (rc);
  423         if (bp && zio_checksum_verify(bp, buf))
  424                 return (EIO);
  425 
  426         return (0);
  427 }
  428 
  429 static int
  430 vdev_disk_read(vdev_t *vdev, const blkptr_t *bp, void *buf,
  431     off_t offset, size_t bytes)
  432 {
  433 
  434         return (vdev_read_phys(vdev, bp, buf,
  435                 offset + VDEV_LABEL_START_SIZE, bytes));
  436 }
  437 
  438 
  439 static int
  440 vdev_mirror_read(vdev_t *vdev, const blkptr_t *bp, void *buf,
  441     off_t offset, size_t bytes)
  442 {
  443         vdev_t *kid;
  444         int rc;
  445 
  446         rc = EIO;
  447         STAILQ_FOREACH(kid, &vdev->v_children, v_childlink) {
  448                 if (kid->v_state != VDEV_STATE_HEALTHY)
  449                         continue;
  450                 rc = kid->v_read(kid, bp, buf, offset, bytes);
  451                 if (!rc)
  452                         return (0);
  453         }
  454 
  455         return (rc);
  456 }
  457 
  458 static int
  459 vdev_replacing_read(vdev_t *vdev, const blkptr_t *bp, void *buf,
  460     off_t offset, size_t bytes)
  461 {
  462         vdev_t *kid;
  463 
  464         /*
  465          * Here we should have two kids:
  466          * First one which is the one we are replacing and we can trust
  467          * only this one to have valid data, but it might not be present.
  468          * Second one is that one we are replacing with. It is most likely
  469          * healthy, but we can't trust it has needed data, so we won't use it.
  470          */
  471         kid = STAILQ_FIRST(&vdev->v_children);
  472         if (kid == NULL)
  473                 return (EIO);
  474         if (kid->v_state != VDEV_STATE_HEALTHY)
  475                 return (EIO);
  476         return (kid->v_read(kid, bp, buf, offset, bytes));
  477 }
  478 
  479 static vdev_t *
  480 vdev_find(uint64_t guid)
  481 {
  482         vdev_t *vdev;
  483 
  484         STAILQ_FOREACH(vdev, &zfs_vdevs, v_alllink)
  485                 if (vdev->v_guid == guid)
  486                         return (vdev);
  487 
  488         return (0);
  489 }
  490 
  491 static vdev_t *
  492 vdev_create(uint64_t guid, vdev_read_t *read)
  493 {
  494         vdev_t *vdev;
  495 
  496         vdev = malloc(sizeof(vdev_t));
  497         memset(vdev, 0, sizeof(vdev_t));
  498         STAILQ_INIT(&vdev->v_children);
  499         vdev->v_guid = guid;
  500         vdev->v_state = VDEV_STATE_OFFLINE;
  501         vdev->v_read = read;
  502         vdev->v_phys_read = 0;
  503         vdev->v_read_priv = 0;
  504         STAILQ_INSERT_TAIL(&zfs_vdevs, vdev, v_alllink);
  505 
  506         return (vdev);
  507 }
  508 
  509 static int
  510 vdev_init_from_nvlist(const unsigned char *nvlist, vdev_t *pvdev,
  511     vdev_t **vdevp, int is_newer)
  512 {
  513         int rc;
  514         uint64_t guid, id, ashift, nparity;
  515         const char *type;
  516         const char *path;
  517         vdev_t *vdev, *kid;
  518         const unsigned char *kids;
  519         int nkids, i, is_new;
  520         uint64_t is_offline, is_faulted, is_degraded, is_removed, isnt_present;
  521 
  522         if (nvlist_find(nvlist, ZPOOL_CONFIG_GUID,
  523                         DATA_TYPE_UINT64, 0, &guid)
  524             || nvlist_find(nvlist, ZPOOL_CONFIG_ID,
  525                            DATA_TYPE_UINT64, 0, &id)
  526             || nvlist_find(nvlist, ZPOOL_CONFIG_TYPE,
  527                            DATA_TYPE_STRING, 0, &type)) {
  528                 printf("ZFS: can't find vdev details\n");
  529                 return (ENOENT);
  530         }
  531 
  532         if (strcmp(type, VDEV_TYPE_MIRROR)
  533             && strcmp(type, VDEV_TYPE_DISK)
  534 #ifdef ZFS_TEST
  535             && strcmp(type, VDEV_TYPE_FILE)
  536 #endif
  537             && strcmp(type, VDEV_TYPE_RAIDZ)
  538             && strcmp(type, VDEV_TYPE_REPLACING)) {
  539                 printf("ZFS: can only boot from disk, mirror, raidz1, raidz2 and raidz3 vdevs\n");
  540                 return (EIO);
  541         }
  542 
  543         is_offline = is_removed = is_faulted = is_degraded = isnt_present = 0;
  544 
  545         nvlist_find(nvlist, ZPOOL_CONFIG_OFFLINE, DATA_TYPE_UINT64, 0,
  546                         &is_offline);
  547         nvlist_find(nvlist, ZPOOL_CONFIG_REMOVED, DATA_TYPE_UINT64, 0,
  548                         &is_removed);
  549         nvlist_find(nvlist, ZPOOL_CONFIG_FAULTED, DATA_TYPE_UINT64, 0,
  550                         &is_faulted);
  551         nvlist_find(nvlist, ZPOOL_CONFIG_DEGRADED, DATA_TYPE_UINT64, 0,
  552                         &is_degraded);
  553         nvlist_find(nvlist, ZPOOL_CONFIG_NOT_PRESENT, DATA_TYPE_UINT64, 0,
  554                         &isnt_present);
  555 
  556         vdev = vdev_find(guid);
  557         if (!vdev) {
  558                 is_new = 1;
  559 
  560                 if (!strcmp(type, VDEV_TYPE_MIRROR))
  561                         vdev = vdev_create(guid, vdev_mirror_read);
  562                 else if (!strcmp(type, VDEV_TYPE_RAIDZ))
  563                         vdev = vdev_create(guid, vdev_raidz_read);
  564                 else if (!strcmp(type, VDEV_TYPE_REPLACING))
  565                         vdev = vdev_create(guid, vdev_replacing_read);
  566                 else
  567                         vdev = vdev_create(guid, vdev_disk_read);
  568 
  569                 vdev->v_id = id;
  570                 vdev->v_top = pvdev != NULL ? pvdev : vdev;
  571                 if (nvlist_find(nvlist, ZPOOL_CONFIG_ASHIFT,
  572                         DATA_TYPE_UINT64, 0, &ashift) == 0)
  573                         vdev->v_ashift = ashift;
  574                 else
  575                         vdev->v_ashift = 0;
  576                 if (nvlist_find(nvlist, ZPOOL_CONFIG_NPARITY,
  577                         DATA_TYPE_UINT64, 0, &nparity) == 0)
  578                         vdev->v_nparity = nparity;
  579                 else
  580                         vdev->v_nparity = 0;
  581                 if (nvlist_find(nvlist, ZPOOL_CONFIG_PATH,
  582                                 DATA_TYPE_STRING, 0, &path) == 0) {
  583                         if (strncmp(path, "/dev/", 5) == 0)
  584                                 path += 5;
  585                         vdev->v_name = strdup(path);
  586                 } else {
  587                         if (!strcmp(type, "raidz")) {
  588                                 if (vdev->v_nparity == 1)
  589                                         vdev->v_name = "raidz1";
  590                                 else if (vdev->v_nparity == 2)
  591                                         vdev->v_name = "raidz2";
  592                                 else if (vdev->v_nparity == 3)
  593                                         vdev->v_name = "raidz3";
  594                                 else {
  595                                         printf("ZFS: can only boot from disk, mirror, raidz1, raidz2 and raidz3 vdevs\n");
  596                                         return (EIO);
  597                                 }
  598                         } else {
  599                                 vdev->v_name = strdup(type);
  600                         }
  601                 }
  602         } else {
  603                 is_new = 0;
  604         }
  605 
  606         if (is_new || is_newer) {
  607                 /*
  608                  * This is either new vdev or we've already seen this vdev,
  609                  * but from an older vdev label, so let's refresh its state
  610                  * from the newer label.
  611                  */
  612                 if (is_offline)
  613                         vdev->v_state = VDEV_STATE_OFFLINE;
  614                 else if (is_removed)
  615                         vdev->v_state = VDEV_STATE_REMOVED;
  616                 else if (is_faulted)
  617                         vdev->v_state = VDEV_STATE_FAULTED;
  618                 else if (is_degraded)
  619                         vdev->v_state = VDEV_STATE_DEGRADED;
  620                 else if (isnt_present)
  621                         vdev->v_state = VDEV_STATE_CANT_OPEN;
  622         }
  623 
  624         rc = nvlist_find(nvlist, ZPOOL_CONFIG_CHILDREN,
  625                          DATA_TYPE_NVLIST_ARRAY, &nkids, &kids);
  626         /*
  627          * Its ok if we don't have any kids.
  628          */
  629         if (rc == 0) {
  630                 vdev->v_nchildren = nkids;
  631                 for (i = 0; i < nkids; i++) {
  632                         rc = vdev_init_from_nvlist(kids, vdev, &kid, is_newer);
  633                         if (rc)
  634                                 return (rc);
  635                         if (is_new)
  636                                 STAILQ_INSERT_TAIL(&vdev->v_children, kid,
  637                                                    v_childlink);
  638                         kids = nvlist_next(kids);
  639                 }
  640         } else {
  641                 vdev->v_nchildren = 0;
  642         }
  643 
  644         if (vdevp)
  645                 *vdevp = vdev;
  646         return (0);
  647 }
  648 
  649 static void
  650 vdev_set_state(vdev_t *vdev)
  651 {
  652         vdev_t *kid;
  653         int good_kids;
  654         int bad_kids;
  655 
  656         /*
  657          * A mirror or raidz is healthy if all its kids are healthy. A
  658          * mirror is degraded if any of its kids is healthy; a raidz
  659          * is degraded if at most nparity kids are offline.
  660          */
  661         if (STAILQ_FIRST(&vdev->v_children)) {
  662                 good_kids = 0;
  663                 bad_kids = 0;
  664                 STAILQ_FOREACH(kid, &vdev->v_children, v_childlink) {
  665                         if (kid->v_state == VDEV_STATE_HEALTHY)
  666                                 good_kids++;
  667                         else
  668                                 bad_kids++;
  669                 }
  670                 if (bad_kids == 0) {
  671                         vdev->v_state = VDEV_STATE_HEALTHY;
  672                 } else {
  673                         if (vdev->v_read == vdev_mirror_read) {
  674                                 if (good_kids) {
  675                                         vdev->v_state = VDEV_STATE_DEGRADED;
  676                                 } else {
  677                                         vdev->v_state = VDEV_STATE_OFFLINE;
  678                                 }
  679                         } else if (vdev->v_read == vdev_raidz_read) {
  680                                 if (bad_kids > vdev->v_nparity) {
  681                                         vdev->v_state = VDEV_STATE_OFFLINE;
  682                                 } else {
  683                                         vdev->v_state = VDEV_STATE_DEGRADED;
  684                                 }
  685                         }
  686                 }
  687         }
  688 }
  689 
  690 static spa_t *
  691 spa_find_by_guid(uint64_t guid)
  692 {
  693         spa_t *spa;
  694 
  695         STAILQ_FOREACH(spa, &zfs_pools, spa_link)
  696                 if (spa->spa_guid == guid)
  697                         return (spa);
  698 
  699         return (0);
  700 }
  701 
  702 static spa_t *
  703 spa_find_by_name(const char *name)
  704 {
  705         spa_t *spa;
  706 
  707         STAILQ_FOREACH(spa, &zfs_pools, spa_link)
  708                 if (!strcmp(spa->spa_name, name))
  709                         return (spa);
  710 
  711         return (0);
  712 }
  713 
  714 #ifdef BOOT2
  715 static spa_t *
  716 spa_get_primary(void)
  717 {
  718 
  719         return (STAILQ_FIRST(&zfs_pools));
  720 }
  721 
  722 static vdev_t *
  723 spa_get_primary_vdev(const spa_t *spa)
  724 {
  725         vdev_t *vdev;
  726         vdev_t *kid;
  727 
  728         if (spa == NULL)
  729                 spa = spa_get_primary();
  730         if (spa == NULL)
  731                 return (NULL);
  732         vdev = STAILQ_FIRST(&spa->spa_vdevs);
  733         if (vdev == NULL)
  734                 return (NULL);
  735         for (kid = STAILQ_FIRST(&vdev->v_children); kid != NULL;
  736              kid = STAILQ_FIRST(&vdev->v_children))
  737                 vdev = kid;
  738         return (vdev);
  739 }
  740 #endif
  741 
  742 static spa_t *
  743 spa_create(uint64_t guid)
  744 {
  745         spa_t *spa;
  746 
  747         spa = malloc(sizeof(spa_t));
  748         memset(spa, 0, sizeof(spa_t));
  749         STAILQ_INIT(&spa->spa_vdevs);
  750         spa->spa_guid = guid;
  751         STAILQ_INSERT_TAIL(&zfs_pools, spa, spa_link);
  752 
  753         return (spa);
  754 }
  755 
  756 static const char *
  757 state_name(vdev_state_t state)
  758 {
  759         static const char* names[] = {
  760                 "UNKNOWN",
  761                 "CLOSED",
  762                 "OFFLINE",
  763                 "REMOVED",
  764                 "CANT_OPEN",
  765                 "FAULTED",
  766                 "DEGRADED",
  767                 "ONLINE"
  768         };
  769         return names[state];
  770 }
  771 
  772 #ifdef BOOT2
  773 
  774 #define pager_printf printf
  775 
  776 #else
  777 
  778 static void
  779 pager_printf(const char *fmt, ...)
  780 {
  781         char line[80];
  782         va_list args;
  783 
  784         va_start(args, fmt);
  785         vsprintf(line, fmt, args);
  786         va_end(args);
  787         pager_output(line);
  788 }
  789 
  790 #endif
  791 
  792 #define STATUS_FORMAT   "        %s %s\n"
  793 
  794 static void
  795 print_state(int indent, const char *name, vdev_state_t state)
  796 {
  797         int i;
  798         char buf[512];
  799 
  800         buf[0] = 0;
  801         for (i = 0; i < indent; i++)
  802                 strcat(buf, "  ");
  803         strcat(buf, name);
  804         pager_printf(STATUS_FORMAT, buf, state_name(state));
  805         
  806 }
  807 
  808 static void
  809 vdev_status(vdev_t *vdev, int indent)
  810 {
  811         vdev_t *kid;
  812         print_state(indent, vdev->v_name, vdev->v_state);
  813 
  814         STAILQ_FOREACH(kid, &vdev->v_children, v_childlink) {
  815                 vdev_status(kid, indent + 1);
  816         }
  817 }
  818 
  819 static void
  820 spa_status(spa_t *spa)
  821 {
  822         static char bootfs[ZFS_MAXNAMELEN];
  823         uint64_t rootid;
  824         vdev_t *vdev;
  825         int good_kids, bad_kids, degraded_kids;
  826         vdev_state_t state;
  827 
  828         pager_printf("  pool: %s\n", spa->spa_name);
  829         if (zfs_get_root(spa, &rootid) == 0 &&
  830             zfs_rlookup(spa, rootid, bootfs) == 0) {
  831                 if (bootfs[0] == '\0')
  832                         pager_printf("bootfs: %s\n", spa->spa_name);
  833                 else
  834                         pager_printf("bootfs: %s/%s\n", spa->spa_name, bootfs);
  835         }
  836         pager_printf("config:\n\n");
  837         pager_printf(STATUS_FORMAT, "NAME", "STATE");
  838 
  839         good_kids = 0;
  840         degraded_kids = 0;
  841         bad_kids = 0;
  842         STAILQ_FOREACH(vdev, &spa->spa_vdevs, v_childlink) {
  843                 if (vdev->v_state == VDEV_STATE_HEALTHY)
  844                         good_kids++;
  845                 else if (vdev->v_state == VDEV_STATE_DEGRADED)
  846                         degraded_kids++;
  847                 else
  848                         bad_kids++;
  849         }
  850 
  851         state = VDEV_STATE_CLOSED;
  852         if (good_kids > 0 && (degraded_kids + bad_kids) == 0)
  853                 state = VDEV_STATE_HEALTHY;
  854         else if ((good_kids + degraded_kids) > 0)
  855                 state = VDEV_STATE_DEGRADED;
  856 
  857         print_state(0, spa->spa_name, state);
  858         STAILQ_FOREACH(vdev, &spa->spa_vdevs, v_childlink) {
  859                 vdev_status(vdev, 1);
  860         }
  861 }
  862 
  863 static void
  864 spa_all_status(void)
  865 {
  866         spa_t *spa;
  867         int first = 1;
  868 
  869         STAILQ_FOREACH(spa, &zfs_pools, spa_link) {
  870                 if (!first)
  871                         pager_printf("\n");
  872                 first = 0;
  873                 spa_status(spa);
  874         }
  875 }
  876 
  877 static int
  878 vdev_probe(vdev_phys_read_t *read, void *read_priv, spa_t **spap)
  879 {
  880         vdev_t vtmp;
  881         vdev_phys_t *vdev_label = (vdev_phys_t *) zap_scratch;
  882         spa_t *spa;
  883         vdev_t *vdev, *top_vdev, *pool_vdev;
  884         off_t off;
  885         blkptr_t bp;
  886         const unsigned char *nvlist;
  887         uint64_t val;
  888         uint64_t guid;
  889         uint64_t pool_txg, pool_guid;
  890         uint64_t is_log;
  891         const char *pool_name;
  892         const unsigned char *vdevs;
  893         const unsigned char *features;
  894         int i, rc, is_newer;
  895         char *upbuf;
  896         const struct uberblock *up;
  897 
  898         /*
  899          * Load the vdev label and figure out which
  900          * uberblock is most current.
  901          */
  902         memset(&vtmp, 0, sizeof(vtmp));
  903         vtmp.v_phys_read = read;
  904         vtmp.v_read_priv = read_priv;
  905         off = offsetof(vdev_label_t, vl_vdev_phys);
  906         BP_ZERO(&bp);
  907         BP_SET_LSIZE(&bp, sizeof(vdev_phys_t));
  908         BP_SET_PSIZE(&bp, sizeof(vdev_phys_t));
  909         BP_SET_CHECKSUM(&bp, ZIO_CHECKSUM_LABEL);
  910         BP_SET_COMPRESS(&bp, ZIO_COMPRESS_OFF);
  911         DVA_SET_OFFSET(BP_IDENTITY(&bp), off);
  912         ZIO_SET_CHECKSUM(&bp.blk_cksum, off, 0, 0, 0);
  913         if (vdev_read_phys(&vtmp, &bp, vdev_label, off, 0))
  914                 return (EIO);
  915 
  916         if (vdev_label->vp_nvlist[0] != NV_ENCODE_XDR) {
  917                 return (EIO);
  918         }
  919 
  920         nvlist = (const unsigned char *) vdev_label->vp_nvlist + 4;
  921 
  922         if (nvlist_find(nvlist,
  923                         ZPOOL_CONFIG_VERSION,
  924                         DATA_TYPE_UINT64, 0, &val)) {
  925                 return (EIO);
  926         }
  927 
  928         if (!SPA_VERSION_IS_SUPPORTED(val)) {
  929                 printf("ZFS: unsupported ZFS version %u (should be %u)\n",
  930                     (unsigned) val, (unsigned) SPA_VERSION);
  931                 return (EIO);
  932         }
  933 
  934         /* Check ZFS features for read */
  935         if (nvlist_find(nvlist,
  936                         ZPOOL_CONFIG_FEATURES_FOR_READ,
  937                         DATA_TYPE_NVLIST, 0, &features) == 0
  938             && nvlist_check_features_for_read(features) != 0)
  939                 return (EIO);
  940 
  941         if (nvlist_find(nvlist,
  942                         ZPOOL_CONFIG_POOL_STATE,
  943                         DATA_TYPE_UINT64, 0, &val)) {
  944                 return (EIO);
  945         }
  946 
  947         if (val == POOL_STATE_DESTROYED) {
  948                 /* We don't boot only from destroyed pools. */
  949                 return (EIO);
  950         }
  951 
  952         if (nvlist_find(nvlist,
  953                         ZPOOL_CONFIG_POOL_TXG,
  954                         DATA_TYPE_UINT64, 0, &pool_txg)
  955             || nvlist_find(nvlist,
  956                            ZPOOL_CONFIG_POOL_GUID,
  957                            DATA_TYPE_UINT64, 0, &pool_guid)
  958             || nvlist_find(nvlist,
  959                            ZPOOL_CONFIG_POOL_NAME,
  960                            DATA_TYPE_STRING, 0, &pool_name)) {
  961                 /*
  962                  * Cache and spare devices end up here - just ignore
  963                  * them.
  964                  */
  965                 /*printf("ZFS: can't find pool details\n");*/
  966                 return (EIO);
  967         }
  968 
  969         is_log = 0;
  970         (void) nvlist_find(nvlist, ZPOOL_CONFIG_IS_LOG, DATA_TYPE_UINT64, 0,
  971             &is_log);
  972         if (is_log)
  973                 return (EIO);
  974 
  975         /*
  976          * Create the pool if this is the first time we've seen it.
  977          */
  978         spa = spa_find_by_guid(pool_guid);
  979         if (!spa) {
  980                 spa = spa_create(pool_guid);
  981                 spa->spa_name = strdup(pool_name);
  982         }
  983         if (pool_txg > spa->spa_txg) {
  984                 spa->spa_txg = pool_txg;
  985                 is_newer = 1;
  986         } else
  987                 is_newer = 0;
  988 
  989         /*
  990          * Get the vdev tree and create our in-core copy of it.
  991          * If we already have a vdev with this guid, this must
  992          * be some kind of alias (overlapping slices, dangerously dedicated
  993          * disks etc).
  994          */
  995         if (nvlist_find(nvlist,
  996                         ZPOOL_CONFIG_GUID,
  997                         DATA_TYPE_UINT64, 0, &guid)) {
  998                 return (EIO);
  999         }
 1000         vdev = vdev_find(guid);
 1001         if (vdev && vdev->v_phys_read)  /* Has this vdev already been inited? */
 1002                 return (EIO);
 1003 
 1004         if (nvlist_find(nvlist,
 1005                         ZPOOL_CONFIG_VDEV_TREE,
 1006                         DATA_TYPE_NVLIST, 0, &vdevs)) {
 1007                 return (EIO);
 1008         }
 1009 
 1010         rc = vdev_init_from_nvlist(vdevs, NULL, &top_vdev, is_newer);
 1011         if (rc)
 1012                 return (rc);
 1013 
 1014         /*
 1015          * Add the toplevel vdev to the pool if its not already there.
 1016          */
 1017         STAILQ_FOREACH(pool_vdev, &spa->spa_vdevs, v_childlink)
 1018                 if (top_vdev == pool_vdev)
 1019                         break;
 1020         if (!pool_vdev && top_vdev)
 1021                 STAILQ_INSERT_TAIL(&spa->spa_vdevs, top_vdev, v_childlink);
 1022 
 1023         /*
 1024          * We should already have created an incomplete vdev for this
 1025          * vdev. Find it and initialise it with our read proc.
 1026          */
 1027         vdev = vdev_find(guid);
 1028         if (vdev) {
 1029                 vdev->v_phys_read = read;
 1030                 vdev->v_read_priv = read_priv;
 1031                 vdev->v_state = VDEV_STATE_HEALTHY;
 1032         } else {
 1033                 printf("ZFS: inconsistent nvlist contents\n");
 1034                 return (EIO);
 1035         }
 1036 
 1037         /*
 1038          * Re-evaluate top-level vdev state.
 1039          */
 1040         vdev_set_state(top_vdev);
 1041 
 1042         /*
 1043          * Ok, we are happy with the pool so far. Lets find
 1044          * the best uberblock and then we can actually access
 1045          * the contents of the pool.
 1046          */
 1047         upbuf = zfs_alloc(VDEV_UBERBLOCK_SIZE(vdev));
 1048         up = (const struct uberblock *)upbuf;
 1049         for (i = 0;
 1050              i < VDEV_UBERBLOCK_COUNT(vdev);
 1051              i++) {
 1052                 off = VDEV_UBERBLOCK_OFFSET(vdev, i);
 1053                 BP_ZERO(&bp);
 1054                 DVA_SET_OFFSET(&bp.blk_dva[0], off);
 1055                 BP_SET_LSIZE(&bp, VDEV_UBERBLOCK_SIZE(vdev));
 1056                 BP_SET_PSIZE(&bp, VDEV_UBERBLOCK_SIZE(vdev));
 1057                 BP_SET_CHECKSUM(&bp, ZIO_CHECKSUM_LABEL);
 1058                 BP_SET_COMPRESS(&bp, ZIO_COMPRESS_OFF);
 1059                 ZIO_SET_CHECKSUM(&bp.blk_cksum, off, 0, 0, 0);
 1060 
 1061                 if (vdev_read_phys(vdev, &bp, upbuf, off, 0))
 1062                         continue;
 1063 
 1064                 if (up->ub_magic != UBERBLOCK_MAGIC)
 1065                         continue;
 1066                 if (up->ub_txg < spa->spa_txg)
 1067                         continue;
 1068                 if (up->ub_txg > spa->spa_uberblock.ub_txg) {
 1069                         spa->spa_uberblock = *up;
 1070                 } else if (up->ub_txg == spa->spa_uberblock.ub_txg) {
 1071                         if (up->ub_timestamp > spa->spa_uberblock.ub_timestamp)
 1072                                 spa->spa_uberblock = *up;
 1073                 }
 1074         }
 1075         zfs_free(upbuf, VDEV_UBERBLOCK_SIZE(vdev));
 1076 
 1077         if (spap)
 1078                 *spap = spa;
 1079         return (0);
 1080 }
 1081 
 1082 static int
 1083 ilog2(int n)
 1084 {
 1085         int v;
 1086 
 1087         for (v = 0; v < 32; v++)
 1088                 if (n == (1 << v))
 1089                         return v;
 1090         return -1;
 1091 }
 1092 
 1093 static int
 1094 zio_read_gang(const spa_t *spa, const blkptr_t *bp, void *buf)
 1095 {
 1096         blkptr_t gbh_bp;
 1097         zio_gbh_phys_t zio_gb;
 1098         char *pbuf;
 1099         int i;
 1100 
 1101         /* Artificial BP for gang block header. */
 1102         gbh_bp = *bp;
 1103         BP_SET_PSIZE(&gbh_bp, SPA_GANGBLOCKSIZE);
 1104         BP_SET_LSIZE(&gbh_bp, SPA_GANGBLOCKSIZE);
 1105         BP_SET_CHECKSUM(&gbh_bp, ZIO_CHECKSUM_GANG_HEADER);
 1106         BP_SET_COMPRESS(&gbh_bp, ZIO_COMPRESS_OFF);
 1107         for (i = 0; i < SPA_DVAS_PER_BP; i++)
 1108                 DVA_SET_GANG(&gbh_bp.blk_dva[i], 0);
 1109 
 1110         /* Read gang header block using the artificial BP. */
 1111         if (zio_read(spa, &gbh_bp, &zio_gb))
 1112                 return (EIO);
 1113 
 1114         pbuf = buf;
 1115         for (i = 0; i < SPA_GBH_NBLKPTRS; i++) {
 1116                 blkptr_t *gbp = &zio_gb.zg_blkptr[i];
 1117 
 1118                 if (BP_IS_HOLE(gbp))
 1119                         continue;
 1120                 if (zio_read(spa, gbp, pbuf))
 1121                         return (EIO);
 1122                 pbuf += BP_GET_PSIZE(gbp);
 1123         }
 1124 
 1125         if (zio_checksum_verify(bp, buf))
 1126                 return (EIO);
 1127         return (0);
 1128 }
 1129 
 1130 static int
 1131 zio_read(const spa_t *spa, const blkptr_t *bp, void *buf)
 1132 {
 1133         int cpfunc = BP_GET_COMPRESS(bp);
 1134         uint64_t align, size;
 1135         void *pbuf;
 1136         int i, error;
 1137 
 1138         /*
 1139          * Process data embedded in block pointer
 1140          */
 1141         if (BP_IS_EMBEDDED(bp)) {
 1142                 ASSERT(BPE_GET_ETYPE(bp) == BP_EMBEDDED_TYPE_DATA);
 1143 
 1144                 size = BPE_GET_PSIZE(bp);
 1145                 ASSERT(size <= BPE_PAYLOAD_SIZE);
 1146 
 1147                 if (cpfunc != ZIO_COMPRESS_OFF)
 1148                         pbuf = zfs_alloc(size);
 1149                 else
 1150                         pbuf = buf;
 1151 
 1152                 decode_embedded_bp_compressed(bp, pbuf);
 1153                 error = 0;
 1154 
 1155                 if (cpfunc != ZIO_COMPRESS_OFF) {
 1156                         error = zio_decompress_data(cpfunc, pbuf,
 1157                             size, buf, BP_GET_LSIZE(bp));
 1158                         zfs_free(pbuf, size);
 1159                 }
 1160                 if (error != 0)
 1161                         printf("ZFS: i/o error - unable to decompress block pointer data, error %d\n",
 1162                             error);
 1163                 return (error);
 1164         }
 1165 
 1166         error = EIO;
 1167 
 1168         for (i = 0; i < SPA_DVAS_PER_BP; i++) {
 1169                 const dva_t *dva = &bp->blk_dva[i];
 1170                 vdev_t *vdev;
 1171                 int vdevid;
 1172                 off_t offset;
 1173 
 1174                 if (!dva->dva_word[0] && !dva->dva_word[1])
 1175                         continue;
 1176 
 1177                 vdevid = DVA_GET_VDEV(dva);
 1178                 offset = DVA_GET_OFFSET(dva);
 1179                 STAILQ_FOREACH(vdev, &spa->spa_vdevs, v_childlink) {
 1180                         if (vdev->v_id == vdevid)
 1181                                 break;
 1182                 }
 1183                 if (!vdev || !vdev->v_read)
 1184                         continue;
 1185 
 1186                 size = BP_GET_PSIZE(bp);
 1187                 if (vdev->v_read == vdev_raidz_read) {
 1188                         align = 1ULL << vdev->v_top->v_ashift;
 1189                         if (P2PHASE(size, align) != 0)
 1190                                 size = P2ROUNDUP(size, align);
 1191                 }
 1192                 if (size != BP_GET_PSIZE(bp) || cpfunc != ZIO_COMPRESS_OFF)
 1193                         pbuf = zfs_alloc(size);
 1194                 else
 1195                         pbuf = buf;
 1196 
 1197                 if (DVA_GET_GANG(dva))
 1198                         error = zio_read_gang(spa, bp, pbuf);
 1199                 else
 1200                         error = vdev->v_read(vdev, bp, pbuf, offset, size);
 1201                 if (error == 0) {
 1202                         if (cpfunc != ZIO_COMPRESS_OFF)
 1203                                 error = zio_decompress_data(cpfunc, pbuf,
 1204                                     BP_GET_PSIZE(bp), buf, BP_GET_LSIZE(bp));
 1205                         else if (size != BP_GET_PSIZE(bp))
 1206                                 bcopy(pbuf, buf, BP_GET_PSIZE(bp));
 1207                 }
 1208                 if (buf != pbuf)
 1209                         zfs_free(pbuf, size);
 1210                 if (error == 0)
 1211                         break;
 1212         }
 1213         if (error != 0)
 1214                 printf("ZFS: i/o error - all block copies unavailable\n");
 1215         return (error);
 1216 }
 1217 
 1218 static int
 1219 dnode_read(const spa_t *spa, const dnode_phys_t *dnode, off_t offset, void *buf, size_t buflen)
 1220 {
 1221         int ibshift = dnode->dn_indblkshift - SPA_BLKPTRSHIFT;
 1222         int bsize = dnode->dn_datablkszsec << SPA_MINBLOCKSHIFT;
 1223         int nlevels = dnode->dn_nlevels;
 1224         int i, rc;
 1225 
 1226         if (bsize > SPA_MAXBLOCKSIZE) {
 1227                 printf("ZFS: I/O error - blocks larger than 128K are not supported\n");
 1228                 return (EIO);
 1229         }
 1230 
 1231         /*
 1232          * Note: bsize may not be a power of two here so we need to do an
 1233          * actual divide rather than a bitshift.
 1234          */
 1235         while (buflen > 0) {
 1236                 uint64_t bn = offset / bsize;
 1237                 int boff = offset % bsize;
 1238                 int ibn;
 1239                 const blkptr_t *indbp;
 1240                 blkptr_t bp;
 1241 
 1242                 if (bn > dnode->dn_maxblkid)
 1243                         return (EIO);
 1244 
 1245                 if (dnode == dnode_cache_obj && bn == dnode_cache_bn)
 1246                         goto cached;
 1247 
 1248                 indbp = dnode->dn_blkptr;
 1249                 for (i = 0; i < nlevels; i++) {
 1250                         /*
 1251                          * Copy the bp from the indirect array so that
 1252                          * we can re-use the scratch buffer for multi-level
 1253                          * objects.
 1254                          */
 1255                         ibn = bn >> ((nlevels - i - 1) * ibshift);
 1256                         ibn &= ((1 << ibshift) - 1);
 1257                         bp = indbp[ibn];
 1258                         if (BP_IS_HOLE(&bp)) {
 1259                                 memset(dnode_cache_buf, 0, bsize);
 1260                                 break;
 1261                         }
 1262                         rc = zio_read(spa, &bp, dnode_cache_buf);
 1263                         if (rc)
 1264                                 return (rc);
 1265                         indbp = (const blkptr_t *) dnode_cache_buf;
 1266                 }
 1267                 dnode_cache_obj = dnode;
 1268                 dnode_cache_bn = bn;
 1269         cached:
 1270 
 1271                 /*
 1272                  * The buffer contains our data block. Copy what we
 1273                  * need from it and loop.
 1274                  */ 
 1275                 i = bsize - boff;
 1276                 if (i > buflen) i = buflen;
 1277                 memcpy(buf, &dnode_cache_buf[boff], i);
 1278                 buf = ((char*) buf) + i;
 1279                 offset += i;
 1280                 buflen -= i;
 1281         }
 1282 
 1283         return (0);
 1284 }
 1285 
 1286 /*
 1287  * Lookup a value in a microzap directory. Assumes that the zap
 1288  * scratch buffer contains the directory contents.
 1289  */
 1290 static int
 1291 mzap_lookup(const dnode_phys_t *dnode, const char *name, uint64_t *value)
 1292 {
 1293         const mzap_phys_t *mz;
 1294         const mzap_ent_phys_t *mze;
 1295         size_t size;
 1296         int chunks, i;
 1297 
 1298         /*
 1299          * Microzap objects use exactly one block. Read the whole
 1300          * thing.
 1301          */
 1302         size = dnode->dn_datablkszsec * 512;
 1303 
 1304         mz = (const mzap_phys_t *) zap_scratch;
 1305         chunks = size / MZAP_ENT_LEN - 1;
 1306 
 1307         for (i = 0; i < chunks; i++) {
 1308                 mze = &mz->mz_chunk[i];
 1309                 if (!strcmp(mze->mze_name, name)) {
 1310                         *value = mze->mze_value;
 1311                         return (0);
 1312                 }
 1313         }
 1314 
 1315         return (ENOENT);
 1316 }
 1317 
 1318 /*
 1319  * Compare a name with a zap leaf entry. Return non-zero if the name
 1320  * matches.
 1321  */
 1322 static int
 1323 fzap_name_equal(const zap_leaf_t *zl, const zap_leaf_chunk_t *zc, const char *name)
 1324 {
 1325         size_t namelen;
 1326         const zap_leaf_chunk_t *nc;
 1327         const char *p;
 1328 
 1329         namelen = zc->l_entry.le_name_numints;
 1330                         
 1331         nc = &ZAP_LEAF_CHUNK(zl, zc->l_entry.le_name_chunk);
 1332         p = name;
 1333         while (namelen > 0) {
 1334                 size_t len;
 1335                 len = namelen;
 1336                 if (len > ZAP_LEAF_ARRAY_BYTES)
 1337                         len = ZAP_LEAF_ARRAY_BYTES;
 1338                 if (memcmp(p, nc->l_array.la_array, len))
 1339                         return (0);
 1340                 p += len;
 1341                 namelen -= len;
 1342                 nc = &ZAP_LEAF_CHUNK(zl, nc->l_array.la_next);
 1343         }
 1344 
 1345         return 1;
 1346 }
 1347 
 1348 /*
 1349  * Extract a uint64_t value from a zap leaf entry.
 1350  */
 1351 static uint64_t
 1352 fzap_leaf_value(const zap_leaf_t *zl, const zap_leaf_chunk_t *zc)
 1353 {
 1354         const zap_leaf_chunk_t *vc;
 1355         int i;
 1356         uint64_t value;
 1357         const uint8_t *p;
 1358 
 1359         vc = &ZAP_LEAF_CHUNK(zl, zc->l_entry.le_value_chunk);
 1360         for (i = 0, value = 0, p = vc->l_array.la_array; i < 8; i++) {
 1361                 value = (value << 8) | p[i];
 1362         }
 1363 
 1364         return value;
 1365 }
 1366 
 1367 /*
 1368  * Lookup a value in a fatzap directory. Assumes that the zap scratch
 1369  * buffer contains the directory header.
 1370  */
 1371 static int
 1372 fzap_lookup(const spa_t *spa, const dnode_phys_t *dnode, const char *name, uint64_t *value)
 1373 {
 1374         int bsize = dnode->dn_datablkszsec << SPA_MINBLOCKSHIFT;
 1375         zap_phys_t zh = *(zap_phys_t *) zap_scratch;
 1376         fat_zap_t z;
 1377         uint64_t *ptrtbl;
 1378         uint64_t hash;
 1379         int rc;
 1380 
 1381         if (zh.zap_magic != ZAP_MAGIC)
 1382                 return (EIO);
 1383 
 1384         z.zap_block_shift = ilog2(bsize);
 1385         z.zap_phys = (zap_phys_t *) zap_scratch;
 1386 
 1387         /*
 1388          * Figure out where the pointer table is and read it in if necessary.
 1389          */
 1390         if (zh.zap_ptrtbl.zt_blk) {
 1391                 rc = dnode_read(spa, dnode, zh.zap_ptrtbl.zt_blk * bsize,
 1392                                zap_scratch, bsize);
 1393                 if (rc)
 1394                         return (rc);
 1395                 ptrtbl = (uint64_t *) zap_scratch;
 1396         } else {
 1397                 ptrtbl = &ZAP_EMBEDDED_PTRTBL_ENT(&z, 0);
 1398         }
 1399 
 1400         hash = zap_hash(zh.zap_salt, name);
 1401 
 1402         zap_leaf_t zl;
 1403         zl.l_bs = z.zap_block_shift;
 1404 
 1405         off_t off = ptrtbl[hash >> (64 - zh.zap_ptrtbl.zt_shift)] << zl.l_bs;
 1406         zap_leaf_chunk_t *zc;
 1407 
 1408         rc = dnode_read(spa, dnode, off, zap_scratch, bsize);
 1409         if (rc)
 1410                 return (rc);
 1411 
 1412         zl.l_phys = (zap_leaf_phys_t *) zap_scratch;
 1413 
 1414         /*
 1415          * Make sure this chunk matches our hash.
 1416          */
 1417         if (zl.l_phys->l_hdr.lh_prefix_len > 0
 1418             && zl.l_phys->l_hdr.lh_prefix
 1419             != hash >> (64 - zl.l_phys->l_hdr.lh_prefix_len))
 1420                 return (ENOENT);
 1421 
 1422         /*
 1423          * Hash within the chunk to find our entry.
 1424          */
 1425         int shift = (64 - ZAP_LEAF_HASH_SHIFT(&zl) - zl.l_phys->l_hdr.lh_prefix_len);
 1426         int h = (hash >> shift) & ((1 << ZAP_LEAF_HASH_SHIFT(&zl)) - 1);
 1427         h = zl.l_phys->l_hash[h];
 1428         if (h == 0xffff)
 1429                 return (ENOENT);
 1430         zc = &ZAP_LEAF_CHUNK(&zl, h);
 1431         while (zc->l_entry.le_hash != hash) {
 1432                 if (zc->l_entry.le_next == 0xffff) {
 1433                         zc = 0;
 1434                         break;
 1435                 }
 1436                 zc = &ZAP_LEAF_CHUNK(&zl, zc->l_entry.le_next);
 1437         }
 1438         if (fzap_name_equal(&zl, zc, name)) {
 1439                 if (zc->l_entry.le_value_intlen * zc->l_entry.le_value_numints > 8)
 1440                         return (E2BIG);
 1441                 *value = fzap_leaf_value(&zl, zc);
 1442                 return (0);
 1443         }
 1444 
 1445         return (ENOENT);
 1446 }
 1447 
 1448 /*
 1449  * Lookup a name in a zap object and return its value as a uint64_t.
 1450  */
 1451 static int
 1452 zap_lookup(const spa_t *spa, const dnode_phys_t *dnode, const char *name, uint64_t *value)
 1453 {
 1454         int rc;
 1455         uint64_t zap_type;
 1456         size_t size = dnode->dn_datablkszsec << SPA_MINBLOCKSHIFT;
 1457 
 1458         rc = dnode_read(spa, dnode, 0, zap_scratch, size);
 1459         if (rc)
 1460                 return (rc);
 1461 
 1462         zap_type = *(uint64_t *) zap_scratch;
 1463         if (zap_type == ZBT_MICRO)
 1464                 return mzap_lookup(dnode, name, value);
 1465         else if (zap_type == ZBT_HEADER)
 1466                 return fzap_lookup(spa, dnode, name, value);
 1467         printf("ZFS: invalid zap_type=%d\n", (int)zap_type);
 1468         return (EIO);
 1469 }
 1470 
 1471 /*
 1472  * List a microzap directory. Assumes that the zap scratch buffer contains
 1473  * the directory contents.
 1474  */
 1475 static int
 1476 mzap_list(const dnode_phys_t *dnode, int (*callback)(const char *))
 1477 {
 1478         const mzap_phys_t *mz;
 1479         const mzap_ent_phys_t *mze;
 1480         size_t size;
 1481         int chunks, i;
 1482 
 1483         /*
 1484          * Microzap objects use exactly one block. Read the whole
 1485          * thing.
 1486          */
 1487         size = dnode->dn_datablkszsec * 512;
 1488         mz = (const mzap_phys_t *) zap_scratch;
 1489         chunks = size / MZAP_ENT_LEN - 1;
 1490 
 1491         for (i = 0; i < chunks; i++) {
 1492                 mze = &mz->mz_chunk[i];
 1493                 if (mze->mze_name[0])
 1494                         //printf("%-32s 0x%jx\n", mze->mze_name, (uintmax_t)mze->mze_value);
 1495                         callback(mze->mze_name);
 1496         }
 1497 
 1498         return (0);
 1499 }
 1500 
 1501 /*
 1502  * List a fatzap directory. Assumes that the zap scratch buffer contains
 1503  * the directory header.
 1504  */
 1505 static int
 1506 fzap_list(const spa_t *spa, const dnode_phys_t *dnode, int (*callback)(const char *))
 1507 {
 1508         int bsize = dnode->dn_datablkszsec << SPA_MINBLOCKSHIFT;
 1509         zap_phys_t zh = *(zap_phys_t *) zap_scratch;
 1510         fat_zap_t z;
 1511         int i, j;
 1512 
 1513         if (zh.zap_magic != ZAP_MAGIC)
 1514                 return (EIO);
 1515 
 1516         z.zap_block_shift = ilog2(bsize);
 1517         z.zap_phys = (zap_phys_t *) zap_scratch;
 1518 
 1519         /*
 1520          * This assumes that the leaf blocks start at block 1. The
 1521          * documentation isn't exactly clear on this.
 1522          */
 1523         zap_leaf_t zl;
 1524         zl.l_bs = z.zap_block_shift;
 1525         for (i = 0; i < zh.zap_num_leafs; i++) {
 1526                 off_t off = (i + 1) << zl.l_bs;
 1527                 char name[256], *p;
 1528                 uint64_t value;
 1529 
 1530                 if (dnode_read(spa, dnode, off, zap_scratch, bsize))
 1531                         return (EIO);
 1532 
 1533                 zl.l_phys = (zap_leaf_phys_t *) zap_scratch;
 1534 
 1535                 for (j = 0; j < ZAP_LEAF_NUMCHUNKS(&zl); j++) {
 1536                         zap_leaf_chunk_t *zc, *nc;
 1537                         int namelen;
 1538 
 1539                         zc = &ZAP_LEAF_CHUNK(&zl, j);
 1540                         if (zc->l_entry.le_type != ZAP_CHUNK_ENTRY)
 1541                                 continue;
 1542                         namelen = zc->l_entry.le_name_numints;
 1543                         if (namelen > sizeof(name))
 1544                                 namelen = sizeof(name);
 1545 
 1546                         /*
 1547                          * Paste the name back together.
 1548                          */
 1549                         nc = &ZAP_LEAF_CHUNK(&zl, zc->l_entry.le_name_chunk);
 1550                         p = name;
 1551                         while (namelen > 0) {
 1552                                 int len;
 1553                                 len = namelen;
 1554                                 if (len > ZAP_LEAF_ARRAY_BYTES)
 1555                                         len = ZAP_LEAF_ARRAY_BYTES;
 1556                                 memcpy(p, nc->l_array.la_array, len);
 1557                                 p += len;
 1558                                 namelen -= len;
 1559                                 nc = &ZAP_LEAF_CHUNK(&zl, nc->l_array.la_next);
 1560                         }
 1561 
 1562                         /*
 1563                          * Assume the first eight bytes of the value are
 1564                          * a uint64_t.
 1565                          */
 1566                         value = fzap_leaf_value(&zl, zc);
 1567 
 1568                         //printf("%s 0x%jx\n", name, (uintmax_t)value);
 1569                         callback((const char *)name);
 1570                 }
 1571         }
 1572 
 1573         return (0);
 1574 }
 1575 
 1576 static int zfs_printf(const char *name)
 1577 {
 1578 
 1579         printf("%s\n", name);
 1580 
 1581         return (0);
 1582 }
 1583 
 1584 /*
 1585  * List a zap directory.
 1586  */
 1587 static int
 1588 zap_list(const spa_t *spa, const dnode_phys_t *dnode)
 1589 {
 1590         uint64_t zap_type;
 1591         size_t size = dnode->dn_datablkszsec * 512;
 1592 
 1593         if (dnode_read(spa, dnode, 0, zap_scratch, size))
 1594                 return (EIO);
 1595 
 1596         zap_type = *(uint64_t *) zap_scratch;
 1597         if (zap_type == ZBT_MICRO)
 1598                 return mzap_list(dnode, zfs_printf);
 1599         else
 1600                 return fzap_list(spa, dnode, zfs_printf);
 1601 }
 1602 
 1603 static int
 1604 objset_get_dnode(const spa_t *spa, const objset_phys_t *os, uint64_t objnum, dnode_phys_t *dnode)
 1605 {
 1606         off_t offset;
 1607 
 1608         offset = objnum * sizeof(dnode_phys_t);
 1609         return dnode_read(spa, &os->os_meta_dnode, offset,
 1610                 dnode, sizeof(dnode_phys_t));
 1611 }
 1612 
 1613 static int
 1614 mzap_rlookup(const spa_t *spa, const dnode_phys_t *dnode, char *name, uint64_t value)
 1615 {
 1616         const mzap_phys_t *mz;
 1617         const mzap_ent_phys_t *mze;
 1618         size_t size;
 1619         int chunks, i;
 1620 
 1621         /*
 1622          * Microzap objects use exactly one block. Read the whole
 1623          * thing.
 1624          */
 1625         size = dnode->dn_datablkszsec * 512;
 1626 
 1627         mz = (const mzap_phys_t *) zap_scratch;
 1628         chunks = size / MZAP_ENT_LEN - 1;
 1629 
 1630         for (i = 0; i < chunks; i++) {
 1631                 mze = &mz->mz_chunk[i];
 1632                 if (value == mze->mze_value) {
 1633                         strcpy(name, mze->mze_name);
 1634                         return (0);
 1635                 }
 1636         }
 1637 
 1638         return (ENOENT);
 1639 }
 1640 
 1641 static void
 1642 fzap_name_copy(const zap_leaf_t *zl, const zap_leaf_chunk_t *zc, char *name)
 1643 {
 1644         size_t namelen;
 1645         const zap_leaf_chunk_t *nc;
 1646         char *p;
 1647 
 1648         namelen = zc->l_entry.le_name_numints;
 1649 
 1650         nc = &ZAP_LEAF_CHUNK(zl, zc->l_entry.le_name_chunk);
 1651         p = name;
 1652         while (namelen > 0) {
 1653                 size_t len;
 1654                 len = namelen;
 1655                 if (len > ZAP_LEAF_ARRAY_BYTES)
 1656                         len = ZAP_LEAF_ARRAY_BYTES;
 1657                 memcpy(p, nc->l_array.la_array, len);
 1658                 p += len;
 1659                 namelen -= len;
 1660                 nc = &ZAP_LEAF_CHUNK(zl, nc->l_array.la_next);
 1661         }
 1662 
 1663         *p = '\0';
 1664 }
 1665 
 1666 static int
 1667 fzap_rlookup(const spa_t *spa, const dnode_phys_t *dnode, char *name, uint64_t value)
 1668 {
 1669         int bsize = dnode->dn_datablkszsec << SPA_MINBLOCKSHIFT;
 1670         zap_phys_t zh = *(zap_phys_t *) zap_scratch;
 1671         fat_zap_t z;
 1672         int i, j;
 1673 
 1674         if (zh.zap_magic != ZAP_MAGIC)
 1675                 return (EIO);
 1676 
 1677         z.zap_block_shift = ilog2(bsize);
 1678         z.zap_phys = (zap_phys_t *) zap_scratch;
 1679 
 1680         /*
 1681          * This assumes that the leaf blocks start at block 1. The
 1682          * documentation isn't exactly clear on this.
 1683          */
 1684         zap_leaf_t zl;
 1685         zl.l_bs = z.zap_block_shift;
 1686         for (i = 0; i < zh.zap_num_leafs; i++) {
 1687                 off_t off = (i + 1) << zl.l_bs;
 1688 
 1689                 if (dnode_read(spa, dnode, off, zap_scratch, bsize))
 1690                         return (EIO);
 1691 
 1692                 zl.l_phys = (zap_leaf_phys_t *) zap_scratch;
 1693 
 1694                 for (j = 0; j < ZAP_LEAF_NUMCHUNKS(&zl); j++) {
 1695                         zap_leaf_chunk_t *zc;
 1696 
 1697                         zc = &ZAP_LEAF_CHUNK(&zl, j);
 1698                         if (zc->l_entry.le_type != ZAP_CHUNK_ENTRY)
 1699                                 continue;
 1700                         if (zc->l_entry.le_value_intlen != 8 ||
 1701                             zc->l_entry.le_value_numints != 1)
 1702                                 continue;
 1703 
 1704                         if (fzap_leaf_value(&zl, zc) == value) {
 1705                                 fzap_name_copy(&zl, zc, name);
 1706                                 return (0);
 1707                         }
 1708                 }
 1709         }
 1710 
 1711         return (ENOENT);
 1712 }
 1713 
 1714 static int
 1715 zap_rlookup(const spa_t *spa, const dnode_phys_t *dnode, char *name, uint64_t value)
 1716 {
 1717         int rc;
 1718         uint64_t zap_type;
 1719         size_t size = dnode->dn_datablkszsec * 512;
 1720 
 1721         rc = dnode_read(spa, dnode, 0, zap_scratch, size);
 1722         if (rc)
 1723                 return (rc);
 1724 
 1725         zap_type = *(uint64_t *) zap_scratch;
 1726         if (zap_type == ZBT_MICRO)
 1727                 return mzap_rlookup(spa, dnode, name, value);
 1728         else
 1729                 return fzap_rlookup(spa, dnode, name, value);
 1730 }
 1731 
 1732 static int
 1733 zfs_rlookup(const spa_t *spa, uint64_t objnum, char *result)
 1734 {
 1735         char name[256];
 1736         char component[256];
 1737         uint64_t dir_obj, parent_obj, child_dir_zapobj;
 1738         dnode_phys_t child_dir_zap, dataset, dir, parent;
 1739         dsl_dir_phys_t *dd;
 1740         dsl_dataset_phys_t *ds;
 1741         char *p;
 1742         int len;
 1743 
 1744         p = &name[sizeof(name) - 1];
 1745         *p = '\0';
 1746 
 1747         if (objset_get_dnode(spa, &spa->spa_mos, objnum, &dataset)) {
 1748                 printf("ZFS: can't find dataset %ju\n", (uintmax_t)objnum);
 1749                 return (EIO);
 1750         }
 1751         ds = (dsl_dataset_phys_t *)&dataset.dn_bonus;
 1752         dir_obj = ds->ds_dir_obj;
 1753 
 1754         for (;;) {
 1755                 if (objset_get_dnode(spa, &spa->spa_mos, dir_obj, &dir) != 0)
 1756                         return (EIO);
 1757                 dd = (dsl_dir_phys_t *)&dir.dn_bonus;
 1758 
 1759                 /* Actual loop condition. */
 1760                 parent_obj  = dd->dd_parent_obj;
 1761                 if (parent_obj == 0)
 1762                         break;
 1763 
 1764                 if (objset_get_dnode(spa, &spa->spa_mos, parent_obj, &parent) != 0)
 1765                         return (EIO);
 1766                 dd = (dsl_dir_phys_t *)&parent.dn_bonus;
 1767                 child_dir_zapobj = dd->dd_child_dir_zapobj;
 1768                 if (objset_get_dnode(spa, &spa->spa_mos, child_dir_zapobj, &child_dir_zap) != 0)
 1769                         return (EIO);
 1770                 if (zap_rlookup(spa, &child_dir_zap, component, dir_obj) != 0)
 1771                         return (EIO);
 1772 
 1773                 len = strlen(component);
 1774                 p -= len;
 1775                 memcpy(p, component, len);
 1776                 --p;
 1777                 *p = '/';
 1778 
 1779                 /* Actual loop iteration. */
 1780                 dir_obj = parent_obj;
 1781         }
 1782 
 1783         if (*p != '\0')
 1784                 ++p;
 1785         strcpy(result, p);
 1786 
 1787         return (0);
 1788 }
 1789 
 1790 static int
 1791 zfs_lookup_dataset(const spa_t *spa, const char *name, uint64_t *objnum)
 1792 {
 1793         char element[256];
 1794         uint64_t dir_obj, child_dir_zapobj;
 1795         dnode_phys_t child_dir_zap, dir;
 1796         dsl_dir_phys_t *dd;
 1797         const char *p, *q;
 1798 
 1799         if (objset_get_dnode(spa, &spa->spa_mos, DMU_POOL_DIRECTORY_OBJECT, &dir))
 1800                 return (EIO);
 1801         if (zap_lookup(spa, &dir, DMU_POOL_ROOT_DATASET, &dir_obj))
 1802                 return (EIO);
 1803 
 1804         p = name;
 1805         for (;;) {
 1806                 if (objset_get_dnode(spa, &spa->spa_mos, dir_obj, &dir))
 1807                         return (EIO);
 1808                 dd = (dsl_dir_phys_t *)&dir.dn_bonus;
 1809 
 1810                 while (*p == '/')
 1811                         p++;
 1812                 /* Actual loop condition #1. */
 1813                 if (*p == '\0')
 1814                         break;
 1815 
 1816                 q = strchr(p, '/');
 1817                 if (q) {
 1818                         memcpy(element, p, q - p);
 1819                         element[q - p] = '\0';
 1820                         p = q + 1;
 1821                 } else {
 1822                         strcpy(element, p);
 1823                         p += strlen(p);
 1824                 }
 1825 
 1826                 child_dir_zapobj = dd->dd_child_dir_zapobj;
 1827                 if (objset_get_dnode(spa, &spa->spa_mos, child_dir_zapobj, &child_dir_zap) != 0)
 1828                         return (EIO);
 1829 
 1830                 /* Actual loop condition #2. */
 1831                 if (zap_lookup(spa, &child_dir_zap, element, &dir_obj) != 0)
 1832                         return (ENOENT);
 1833         }
 1834 
 1835         *objnum = dd->dd_head_dataset_obj;
 1836         return (0);
 1837 }
 1838 
 1839 #ifndef BOOT2
 1840 static int
 1841 zfs_list_dataset(const spa_t *spa, uint64_t objnum/*, int pos, char *entry*/)
 1842 {
 1843         uint64_t dir_obj, child_dir_zapobj;
 1844         dnode_phys_t child_dir_zap, dir, dataset;
 1845         dsl_dataset_phys_t *ds;
 1846         dsl_dir_phys_t *dd;
 1847 
 1848         if (objset_get_dnode(spa, &spa->spa_mos, objnum, &dataset)) {
 1849                 printf("ZFS: can't find dataset %ju\n", (uintmax_t)objnum);
 1850                 return (EIO);
 1851         }
 1852         ds = (dsl_dataset_phys_t *) &dataset.dn_bonus;
 1853         dir_obj = ds->ds_dir_obj;
 1854 
 1855         if (objset_get_dnode(spa, &spa->spa_mos, dir_obj, &dir)) {
 1856                 printf("ZFS: can't find dirobj %ju\n", (uintmax_t)dir_obj);
 1857                 return (EIO);
 1858         }
 1859         dd = (dsl_dir_phys_t *)&dir.dn_bonus;
 1860 
 1861         child_dir_zapobj = dd->dd_child_dir_zapobj;
 1862         if (objset_get_dnode(spa, &spa->spa_mos, child_dir_zapobj, &child_dir_zap) != 0) {
 1863                 printf("ZFS: can't find child zap %ju\n", (uintmax_t)dir_obj);
 1864                 return (EIO);
 1865         }
 1866 
 1867         return (zap_list(spa, &child_dir_zap) != 0);
 1868 }
 1869 
 1870 int
 1871 zfs_callback_dataset(const spa_t *spa, uint64_t objnum, int (*callback)(const char *name))
 1872 {
 1873         uint64_t dir_obj, child_dir_zapobj, zap_type;
 1874         dnode_phys_t child_dir_zap, dir, dataset;
 1875         dsl_dataset_phys_t *ds;
 1876         dsl_dir_phys_t *dd;
 1877         int err;
 1878 
 1879         err = objset_get_dnode(spa, &spa->spa_mos, objnum, &dataset);
 1880         if (err != 0) {
 1881                 printf("ZFS: can't find dataset %ju\n", (uintmax_t)objnum);
 1882                 return (err);
 1883         }
 1884         ds = (dsl_dataset_phys_t *) &dataset.dn_bonus;
 1885         dir_obj = ds->ds_dir_obj;
 1886 
 1887         err = objset_get_dnode(spa, &spa->spa_mos, dir_obj, &dir);
 1888         if (err != 0) {
 1889                 printf("ZFS: can't find dirobj %ju\n", (uintmax_t)dir_obj);
 1890                 return (err);
 1891         }
 1892         dd = (dsl_dir_phys_t *)&dir.dn_bonus;
 1893 
 1894         child_dir_zapobj = dd->dd_child_dir_zapobj;
 1895         err = objset_get_dnode(spa, &spa->spa_mos, child_dir_zapobj, &child_dir_zap);
 1896         if (err != 0) {
 1897                 printf("ZFS: can't find child zap %ju\n", (uintmax_t)dir_obj);
 1898                 return (err);
 1899         }
 1900 
 1901         err = dnode_read(spa, &child_dir_zap, 0, zap_scratch, child_dir_zap.dn_datablkszsec * 512);
 1902         if (err != 0)
 1903                 return (err);
 1904 
 1905         zap_type = *(uint64_t *) zap_scratch;
 1906         if (zap_type == ZBT_MICRO)
 1907                 return mzap_list(&child_dir_zap, callback);
 1908         else
 1909                 return fzap_list(spa, &child_dir_zap, callback);
 1910 }
 1911 #endif
 1912 
 1913 /*
 1914  * Find the object set given the object number of its dataset object
 1915  * and return its details in *objset
 1916  */
 1917 static int
 1918 zfs_mount_dataset(const spa_t *spa, uint64_t objnum, objset_phys_t *objset)
 1919 {
 1920         dnode_phys_t dataset;
 1921         dsl_dataset_phys_t *ds;
 1922 
 1923         if (objset_get_dnode(spa, &spa->spa_mos, objnum, &dataset)) {
 1924                 printf("ZFS: can't find dataset %ju\n", (uintmax_t)objnum);
 1925                 return (EIO);
 1926         }
 1927 
 1928         ds = (dsl_dataset_phys_t *) &dataset.dn_bonus;
 1929         if (zio_read(spa, &ds->ds_bp, objset)) {
 1930                 printf("ZFS: can't read object set for dataset %ju\n",
 1931                     (uintmax_t)objnum);
 1932                 return (EIO);
 1933         }
 1934 
 1935         return (0);
 1936 }
 1937 
 1938 /*
 1939  * Find the object set pointed to by the BOOTFS property or the root
 1940  * dataset if there is none and return its details in *objset
 1941  */
 1942 static int
 1943 zfs_get_root(const spa_t *spa, uint64_t *objid)
 1944 {
 1945         dnode_phys_t dir, propdir;
 1946         uint64_t props, bootfs, root;
 1947 
 1948         *objid = 0;
 1949 
 1950         /*
 1951          * Start with the MOS directory object.
 1952          */
 1953         if (objset_get_dnode(spa, &spa->spa_mos, DMU_POOL_DIRECTORY_OBJECT, &dir)) {
 1954                 printf("ZFS: can't read MOS object directory\n");
 1955                 return (EIO);
 1956         }
 1957 
 1958         /*
 1959          * Lookup the pool_props and see if we can find a bootfs.
 1960          */
 1961         if (zap_lookup(spa, &dir, DMU_POOL_PROPS, &props) == 0
 1962              && objset_get_dnode(spa, &spa->spa_mos, props, &propdir) == 0
 1963              && zap_lookup(spa, &propdir, "bootfs", &bootfs) == 0
 1964              && bootfs != 0)
 1965         {
 1966                 *objid = bootfs;
 1967                 return (0);
 1968         }
 1969         /*
 1970          * Lookup the root dataset directory
 1971          */
 1972         if (zap_lookup(spa, &dir, DMU_POOL_ROOT_DATASET, &root)
 1973             || objset_get_dnode(spa, &spa->spa_mos, root, &dir)) {
 1974                 printf("ZFS: can't find root dsl_dir\n");
 1975                 return (EIO);
 1976         }
 1977 
 1978         /*
 1979          * Use the information from the dataset directory's bonus buffer
 1980          * to find the dataset object and from that the object set itself.
 1981          */
 1982         dsl_dir_phys_t *dd = (dsl_dir_phys_t *) &dir.dn_bonus;
 1983         *objid = dd->dd_head_dataset_obj;
 1984         return (0);
 1985 }
 1986 
 1987 static int
 1988 zfs_mount(const spa_t *spa, uint64_t rootobj, struct zfsmount *mount)
 1989 {
 1990 
 1991         mount->spa = spa;
 1992 
 1993         /*
 1994          * Find the root object set if not explicitly provided
 1995          */
 1996         if (rootobj == 0 && zfs_get_root(spa, &rootobj)) {
 1997                 printf("ZFS: can't find root filesystem\n");
 1998                 return (EIO);
 1999         }
 2000 
 2001         if (zfs_mount_dataset(spa, rootobj, &mount->objset)) {
 2002                 printf("ZFS: can't open root filesystem\n");
 2003                 return (EIO);
 2004         }
 2005 
 2006         mount->rootobj = rootobj;
 2007 
 2008         return (0);
 2009 }
 2010 
 2011 static int
 2012 zfs_spa_init(spa_t *spa)
 2013 {
 2014 
 2015         if (zio_read(spa, &spa->spa_uberblock.ub_rootbp, &spa->spa_mos)) {
 2016                 printf("ZFS: can't read MOS of pool %s\n", spa->spa_name);
 2017                 return (EIO);
 2018         }
 2019         if (spa->spa_mos.os_type != DMU_OST_META) {
 2020                 printf("ZFS: corrupted MOS of pool %s\n", spa->spa_name);
 2021                 return (EIO);
 2022         }
 2023         return (0);
 2024 }
 2025 
 2026 static int
 2027 zfs_dnode_stat(const spa_t *spa, dnode_phys_t *dn, struct stat *sb)
 2028 {
 2029 
 2030         if (dn->dn_bonustype != DMU_OT_SA) {
 2031                 znode_phys_t *zp = (znode_phys_t *)dn->dn_bonus;
 2032 
 2033                 sb->st_mode = zp->zp_mode;
 2034                 sb->st_uid = zp->zp_uid;
 2035                 sb->st_gid = zp->zp_gid;
 2036                 sb->st_size = zp->zp_size;
 2037         } else {
 2038                 sa_hdr_phys_t *sahdrp;
 2039                 int hdrsize;
 2040                 size_t size = 0;
 2041                 void *buf = NULL;
 2042 
 2043                 if (dn->dn_bonuslen != 0)
 2044                         sahdrp = (sa_hdr_phys_t *)DN_BONUS(dn);
 2045                 else {
 2046                         if ((dn->dn_flags & DNODE_FLAG_SPILL_BLKPTR) != 0) {
 2047                                 blkptr_t *bp = &dn->dn_spill;
 2048                                 int error;
 2049 
 2050                                 size = BP_GET_LSIZE(bp);
 2051                                 buf = zfs_alloc(size);
 2052                                 error = zio_read(spa, bp, buf);
 2053                                 if (error != 0) {
 2054                                         zfs_free(buf, size);
 2055                                         return (error);
 2056                                 }
 2057                                 sahdrp = buf;
 2058                         } else {
 2059                                 return (EIO);
 2060                         }
 2061                 }
 2062                 hdrsize = SA_HDR_SIZE(sahdrp);
 2063                 sb->st_mode = *(uint64_t *)((char *)sahdrp + hdrsize +
 2064                     SA_MODE_OFFSET);
 2065                 sb->st_uid = *(uint64_t *)((char *)sahdrp + hdrsize +
 2066                     SA_UID_OFFSET);
 2067                 sb->st_gid = *(uint64_t *)((char *)sahdrp + hdrsize +
 2068                     SA_GID_OFFSET);
 2069                 sb->st_size = *(uint64_t *)((char *)sahdrp + hdrsize +
 2070                     SA_SIZE_OFFSET);
 2071                 if (buf != NULL)
 2072                         zfs_free(buf, size);
 2073         }
 2074 
 2075         return (0);
 2076 }
 2077 
 2078 /*
 2079  * Lookup a file and return its dnode.
 2080  */
 2081 static int
 2082 zfs_lookup(const struct zfsmount *mount, const char *upath, dnode_phys_t *dnode)
 2083 {
 2084         int rc;
 2085         uint64_t objnum, rootnum, parentnum;
 2086         const spa_t *spa;
 2087         dnode_phys_t dn;
 2088         const char *p, *q;
 2089         char element[256];
 2090         char path[1024];
 2091         int symlinks_followed = 0;
 2092         struct stat sb;
 2093 
 2094         spa = mount->spa;
 2095         if (mount->objset.os_type != DMU_OST_ZFS) {
 2096                 printf("ZFS: unexpected object set type %ju\n",
 2097                     (uintmax_t)mount->objset.os_type);
 2098                 return (EIO);
 2099         }
 2100 
 2101         /*
 2102          * Get the root directory dnode.
 2103          */
 2104         rc = objset_get_dnode(spa, &mount->objset, MASTER_NODE_OBJ, &dn);
 2105         if (rc)
 2106                 return (rc);
 2107 
 2108         rc = zap_lookup(spa, &dn, ZFS_ROOT_OBJ, &rootnum);
 2109         if (rc)
 2110                 return (rc);
 2111 
 2112         rc = objset_get_dnode(spa, &mount->objset, rootnum, &dn);
 2113         if (rc)
 2114                 return (rc);
 2115 
 2116         objnum = rootnum;
 2117         p = upath;
 2118         while (p && *p) {
 2119                 while (*p == '/')
 2120                         p++;
 2121                 if (!*p)
 2122                         break;
 2123                 q = strchr(p, '/');
 2124                 if (q) {
 2125                         memcpy(element, p, q - p);
 2126                         element[q - p] = 0;
 2127                         p = q;
 2128                 } else {
 2129                         strcpy(element, p);
 2130                         p = 0;
 2131                 }
 2132 
 2133                 rc = zfs_dnode_stat(spa, &dn, &sb);
 2134                 if (rc)
 2135                         return (rc);
 2136                 if (!S_ISDIR(sb.st_mode))
 2137                         return (ENOTDIR);
 2138 
 2139                 parentnum = objnum;
 2140                 rc = zap_lookup(spa, &dn, element, &objnum);
 2141                 if (rc)
 2142                         return (rc);
 2143                 objnum = ZFS_DIRENT_OBJ(objnum);
 2144 
 2145                 rc = objset_get_dnode(spa, &mount->objset, objnum, &dn);
 2146                 if (rc)
 2147                         return (rc);
 2148 
 2149                 /*
 2150                  * Check for symlink.
 2151                  */
 2152                 rc = zfs_dnode_stat(spa, &dn, &sb);
 2153                 if (rc)
 2154                         return (rc);
 2155                 if (S_ISLNK(sb.st_mode)) {
 2156                         if (symlinks_followed > 10)
 2157                                 return (EMLINK);
 2158                         symlinks_followed++;
 2159 
 2160                         /*
 2161                          * Read the link value and copy the tail of our
 2162                          * current path onto the end.
 2163                          */
 2164                         if (p)
 2165                                 strcpy(&path[sb.st_size], p);
 2166                         else
 2167                                 path[sb.st_size] = 0;
 2168                         /*
 2169                          * Second test is purely to silence bogus compiler
 2170                          * warning about accessing past the end of dn_bonus.
 2171                          */
 2172                         if (sb.st_size + sizeof(znode_phys_t) <=
 2173                             dn.dn_bonuslen && sizeof(znode_phys_t) <=
 2174                             sizeof(dn.dn_bonus)) {
 2175                                 memcpy(path, &dn.dn_bonus[sizeof(znode_phys_t)],
 2176                                         sb.st_size);
 2177                         } else {
 2178                                 rc = dnode_read(spa, &dn, 0, path, sb.st_size);
 2179                                 if (rc)
 2180                                         return (rc);
 2181                         }
 2182 
 2183                         /*
 2184                          * Restart with the new path, starting either at
 2185                          * the root or at the parent depending whether or
 2186                          * not the link is relative.
 2187                          */
 2188                         p = path;
 2189                         if (*p == '/')
 2190                                 objnum = rootnum;
 2191                         else
 2192                                 objnum = parentnum;
 2193                         objset_get_dnode(spa, &mount->objset, objnum, &dn);
 2194                 }
 2195         }
 2196 
 2197         *dnode = dn;
 2198         return (0);
 2199 }

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