2 * Copyright (c) 2007 Doug Rabson
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
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.
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
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
33 * Stand-alone file reading package.
38 #include <sys/param.h>
40 #include <sys/queue.h>
46 #include <bootstrap.h>
52 /* Define the range of indexes to be populated with ZFS Boot Environments */
53 #define ZFS_BE_FIRST 4
56 static int zfs_open(const char *path, struct open_file *f);
57 static int zfs_close(struct open_file *f);
58 static int zfs_read(struct open_file *f, void *buf, size_t size, size_t *resid);
59 static off_t zfs_seek(struct open_file *f, off_t offset, int where);
60 static int zfs_stat(struct open_file *f, struct stat *sb);
61 static int zfs_readdir(struct open_file *f, struct dirent *d);
63 static void zfs_bootenv_initial(const char *);
67 struct fs_ops zfs_fsops = {
82 off_t f_seekp; /* seek pointer */
84 uint64_t f_zap_type; /* zap type for readdir */
85 uint64_t f_num_leafs; /* number of fzap leaf blocks */
86 zap_leaf_phys_t *f_zap_leaf; /* zap leaf buffer */
89 static int zfs_env_index;
90 static int zfs_env_count;
92 SLIST_HEAD(zfs_be_list, zfs_be_entry) zfs_be_head = SLIST_HEAD_INITIALIZER(zfs_be_head);
93 struct zfs_be_list *zfs_be_headp;
96 SLIST_ENTRY(zfs_be_entry) entries;
97 } *zfs_be, *zfs_be_tmp;
103 zfs_open(const char *upath, struct open_file *f)
105 struct zfsmount *mount = (struct zfsmount *)f->f_devdata;
109 if (f->f_dev != &zfs_dev)
112 /* allocate file system specific data structure */
113 fp = calloc(1, sizeof(struct file));
118 rc = zfs_lookup(mount, upath, &fp->f_dnode);
128 zfs_close(struct open_file *f)
130 struct file *fp = (struct file *)f->f_fsdata;
132 dnode_cache_obj = NULL;
140 * Copy a portion of a file into kernel memory.
141 * Cross block boundaries when necessary.
144 zfs_read(struct open_file *f, void *start, size_t size, size_t *resid /* out */)
146 const spa_t *spa = ((struct zfsmount *)f->f_devdata)->spa;
147 struct file *fp = (struct file *)f->f_fsdata;
152 rc = zfs_stat(f, &sb);
156 if (fp->f_seekp + n > sb.st_size)
157 n = sb.st_size - fp->f_seekp;
159 rc = dnode_read(spa, &fp->f_dnode, fp->f_seekp, start, n);
165 for (i = 0; i < n; i++)
166 putchar(((char*) start)[i]);
176 zfs_seek(struct open_file *f, off_t offset, int where)
178 struct file *fp = (struct file *)f->f_fsdata;
182 fp->f_seekp = offset;
185 fp->f_seekp += offset;
192 error = zfs_stat(f, &sb);
197 fp->f_seekp = sb.st_size - offset;
204 return (fp->f_seekp);
208 zfs_stat(struct open_file *f, struct stat *sb)
210 const spa_t *spa = ((struct zfsmount *)f->f_devdata)->spa;
211 struct file *fp = (struct file *)f->f_fsdata;
213 return (zfs_dnode_stat(spa, &fp->f_dnode, sb));
217 zfs_readdir(struct open_file *f, struct dirent *d)
219 const spa_t *spa = ((struct zfsmount *)f->f_devdata)->spa;
220 struct file *fp = (struct file *)f->f_fsdata;
223 size_t bsize = fp->f_dnode.dn_datablkszsec << SPA_MINBLOCKSHIFT;
226 rc = zfs_stat(f, &sb);
229 if (!S_ISDIR(sb.st_mode))
233 * If this is the first read, get the zap type.
235 if (fp->f_seekp == 0) {
236 rc = dnode_read(spa, &fp->f_dnode,
237 0, &fp->f_zap_type, sizeof(fp->f_zap_type));
241 if (fp->f_zap_type == ZBT_MICRO) {
242 fp->f_seekp = offsetof(mzap_phys_t, mz_chunk);
244 rc = dnode_read(spa, &fp->f_dnode,
245 offsetof(zap_phys_t, zap_num_leafs),
247 sizeof(fp->f_num_leafs));
252 fp->f_zap_leaf = malloc(bsize);
253 if (fp->f_zap_leaf == NULL)
255 rc = dnode_read(spa, &fp->f_dnode,
264 if (fp->f_zap_type == ZBT_MICRO) {
266 if (fp->f_seekp >= bsize)
269 rc = dnode_read(spa, &fp->f_dnode,
270 fp->f_seekp, &mze, sizeof(mze));
273 fp->f_seekp += sizeof(mze);
275 if (!mze.mze_name[0])
278 d->d_fileno = ZFS_DIRENT_OBJ(mze.mze_value);
279 d->d_type = ZFS_DIRENT_TYPE(mze.mze_value);
280 strcpy(d->d_name, mze.mze_name);
281 d->d_namlen = strlen(d->d_name);
285 zap_leaf_chunk_t *zc, *nc;
292 * Initialise this so we can use the ZAP size
293 * calculating macros.
295 zl.l_bs = ilog2(bsize);
296 zl.l_phys = fp->f_zap_leaf;
299 * Figure out which chunk we are currently looking at
300 * and consider seeking to the next leaf. We use the
301 * low bits of f_seekp as a simple chunk index.
304 chunk = fp->f_seekp & (bsize - 1);
305 if (chunk == ZAP_LEAF_NUMCHUNKS(&zl)) {
306 fp->f_seekp = rounddown2(fp->f_seekp, bsize) + bsize;
310 * Check for EOF and read the new leaf.
312 if (fp->f_seekp >= bsize * fp->f_num_leafs)
315 rc = dnode_read(spa, &fp->f_dnode,
323 zc = &ZAP_LEAF_CHUNK(&zl, chunk);
325 if (zc->l_entry.le_type != ZAP_CHUNK_ENTRY)
328 namelen = zc->l_entry.le_name_numints;
329 if (namelen > sizeof(d->d_name))
330 namelen = sizeof(d->d_name);
333 * Paste the name back together.
335 nc = &ZAP_LEAF_CHUNK(&zl, zc->l_entry.le_name_chunk);
337 while (namelen > 0) {
340 if (len > ZAP_LEAF_ARRAY_BYTES)
341 len = ZAP_LEAF_ARRAY_BYTES;
342 memcpy(p, nc->l_array.la_array, len);
345 nc = &ZAP_LEAF_CHUNK(&zl, nc->l_array.la_next);
347 d->d_name[sizeof(d->d_name) - 1] = 0;
350 * Assume the first eight bytes of the value are
353 value = fzap_leaf_value(&zl, zc);
355 d->d_fileno = ZFS_DIRENT_OBJ(value);
356 d->d_type = ZFS_DIRENT_TYPE(value);
357 d->d_namlen = strlen(d->d_name);
364 vdev_read(vdev_t *vdev, void *priv, off_t offset, void *buf, size_t bytes)
367 size_t res, head, tail, total_size, full_sec_size;
368 unsigned secsz, do_tail_read;
370 char *outbuf, *bouncebuf;
372 fd = (uintptr_t) priv;
373 outbuf = (char *) buf;
376 ret = ioctl(fd, DIOCGSECTORSIZE, &secsz);
381 * Handling reads of arbitrary offset and size - multi-sector case
382 * and single-sector case.
385 * (do_tail_read = true if tail > 0)
387 * |<----------------------total_size--------------------->|
389 * |<--head-->|<--------------bytes------------>|<--tail-->|
391 * | | |<~full_sec_size~>| | |
392 * +------------------+ +------------------+
393 * | |0101010| . . . |0101011| |
394 * +------------------+ +------------------+
395 * start_sec start_sec + n
399 * (do_tail_read = false)
401 * |<------total_size = secsz----->|
403 * |<-head->|<---bytes--->|<-tail->|
404 * +-------------------------------+
405 * | |0101010101010| |
406 * +-------------------------------+
409 start_sec = offset / secsz;
410 head = offset % secsz;
411 total_size = roundup2(head + bytes, secsz);
412 tail = total_size - (head + bytes);
413 do_tail_read = ((tail > 0) && (head + bytes > secsz));
414 full_sec_size = total_size;
416 full_sec_size -= secsz;
418 full_sec_size -= secsz;
420 /* Return of partial sector data requires a bounce buffer. */
421 if ((head > 0) || do_tail_read || bytes < secsz) {
422 bouncebuf = malloc(secsz);
423 if (bouncebuf == NULL) {
424 printf("vdev_read: out of memory\n");
429 if (lseek(fd, start_sec * secsz, SEEK_SET) == -1) {
434 /* Partial data return from first sector */
436 res = read(fd, bouncebuf, secsz);
441 memcpy(outbuf, bouncebuf + head, min(secsz - head, bytes));
442 outbuf += min(secsz - head, bytes);
446 * Full data return from read sectors.
447 * Note, there is still corner case where we read
448 * from sector boundary, but less than sector size, e.g. reading 512B
451 if (full_sec_size > 0) {
452 if (bytes < full_sec_size) {
453 res = read(fd, bouncebuf, secsz);
458 memcpy(outbuf, bouncebuf, bytes);
460 res = read(fd, outbuf, full_sec_size);
461 if (res != full_sec_size) {
465 outbuf += full_sec_size;
469 /* Partial data return from last sector */
471 res = read(fd, bouncebuf, secsz);
476 memcpy(outbuf, bouncebuf, secsz - tail);
493 if (archsw.arch_zfs_probe == NULL)
495 archsw.arch_zfs_probe();
498 spa = STAILQ_FIRST(&zfs_pools);
499 while (spa != NULL) {
500 next = STAILQ_NEXT(spa, spa_link);
501 if (zfs_spa_init(spa)) {
503 STAILQ_REMOVE_HEAD(&zfs_pools, spa_link);
505 STAILQ_REMOVE_AFTER(&zfs_pools, prev, spa_link);
513 struct zfs_probe_args {
521 zfs_diskread(void *arg, void *buf, size_t blocks, uint64_t offset)
523 struct zfs_probe_args *ppa;
525 ppa = (struct zfs_probe_args *)arg;
526 return (vdev_read(NULL, (void *)(uintptr_t)ppa->fd,
527 offset * ppa->secsz, buf, blocks * ppa->secsz));
531 zfs_probe(int fd, uint64_t *pool_guid)
537 ret = vdev_probe(vdev_read, (void *)(uintptr_t)fd, &spa);
538 if (ret == 0 && pool_guid != NULL)
539 *pool_guid = spa->spa_guid;
544 zfs_probe_partition(void *arg, const char *partname,
545 const struct ptable_entry *part)
547 struct zfs_probe_args *ppa, pa;
548 struct ptable *table;
552 /* Probe only freebsd-zfs and freebsd partitions */
553 if (part->type != PART_FREEBSD &&
554 part->type != PART_FREEBSD_ZFS)
557 ppa = (struct zfs_probe_args *)arg;
558 strncpy(devname, ppa->devname, strlen(ppa->devname) - 1);
559 devname[strlen(ppa->devname) - 1] = '\0';
560 sprintf(devname, "%s%s:", devname, partname);
561 pa.fd = open(devname, O_RDONLY);
564 ret = zfs_probe(pa.fd, ppa->pool_guid);
567 /* Do we have BSD label here? */
568 if (part->type == PART_FREEBSD) {
569 pa.devname = devname;
570 pa.pool_guid = ppa->pool_guid;
571 pa.secsz = ppa->secsz;
572 table = ptable_open(&pa, part->end - part->start + 1,
573 ppa->secsz, zfs_diskread);
575 ptable_iterate(table, &pa, zfs_probe_partition);
584 zfs_probe_dev(const char *devname, uint64_t *pool_guid)
586 struct disk_devdesc *dev;
587 struct ptable *table;
588 struct zfs_probe_args pa;
594 pa.fd = open(devname, O_RDONLY);
598 * We will not probe the whole disk, we can not boot from such
599 * disks and some systems will misreport the disk sizes and will
600 * hang while accessing the disk.
602 if (archsw.arch_getdev((void **)&dev, devname, NULL) == 0) {
603 int partition = dev->d_partition;
604 int slice = dev->d_slice;
607 if (partition != D_PARTNONE && slice != D_SLICENONE) {
608 ret = zfs_probe(pa.fd, pool_guid);
614 /* Probe each partition */
615 ret = ioctl(pa.fd, DIOCGMEDIASIZE, &mediasz);
617 ret = ioctl(pa.fd, DIOCGSECTORSIZE, &pa.secsz);
619 pa.devname = devname;
620 pa.pool_guid = pool_guid;
621 table = ptable_open(&pa, mediasz / pa.secsz, pa.secsz,
624 ptable_iterate(table, &pa, zfs_probe_partition);
629 if (pool_guid && *pool_guid == 0)
635 * Print information about ZFS pools
638 zfs_dev_print(int verbose)
644 if (STAILQ_EMPTY(&zfs_pools))
647 printf("%s devices:", zfs_dev.dv_name);
648 if ((ret = pager_output("\n")) != 0)
652 return (spa_all_status());
654 STAILQ_FOREACH(spa, &zfs_pools, spa_link) {
655 snprintf(line, sizeof(line), " zfs:%s\n", spa->spa_name);
656 ret = pager_output(line);
664 * Attempt to open the pool described by (dev) for use by (f).
667 zfs_dev_open(struct open_file *f, ...)
670 struct zfs_devdesc *dev;
671 struct zfsmount *mount;
676 dev = va_arg(args, struct zfs_devdesc *);
679 if (dev->pool_guid == 0)
680 spa = STAILQ_FIRST(&zfs_pools);
682 spa = spa_find_by_guid(dev->pool_guid);
685 mount = malloc(sizeof(*mount));
689 rv = zfs_mount(spa, dev->root_guid, mount);
694 if (mount->objset.os_type != DMU_OST_ZFS) {
695 printf("Unexpected object set type %ju\n",
696 (uintmax_t)mount->objset.os_type);
700 f->f_devdata = mount;
706 zfs_dev_close(struct open_file *f)
715 zfs_dev_strategy(void *devdata, int rw, daddr_t dblk, size_t size, char *buf, size_t *rsize)
721 struct devsw zfs_dev = {
724 .dv_init = zfs_dev_init,
725 .dv_strategy = zfs_dev_strategy,
726 .dv_open = zfs_dev_open,
727 .dv_close = zfs_dev_close,
729 .dv_print = zfs_dev_print,
734 zfs_parsedev(struct zfs_devdesc *dev, const char *devspec, const char **path)
736 static char rootname[ZFS_MAXNAMELEN];
737 static char poolname[ZFS_MAXNAMELEN];
748 end = strrchr(np, ':');
751 sep = strchr(np, '/');
752 if (sep == NULL || sep >= end)
754 memcpy(poolname, np, sep - np);
755 poolname[sep - np] = '\0';
758 memcpy(rootname, sep, end - sep);
759 rootname[end - sep] = '\0';
764 spa = spa_find_by_name(poolname);
767 dev->pool_guid = spa->spa_guid;
768 rv = zfs_lookup_dataset(spa, rootname, &dev->root_guid);
772 *path = (*end == '\0') ? end : end + 1;
773 dev->dd.d_dev = &zfs_dev;
778 zfs_fmtdev(void *vdev)
780 static char rootname[ZFS_MAXNAMELEN];
781 static char buf[2 * ZFS_MAXNAMELEN + 8];
782 struct zfs_devdesc *dev = (struct zfs_devdesc *)vdev;
786 if (dev->dd.d_dev->dv_type != DEVT_ZFS)
789 /* Do we have any pools? */
790 spa = STAILQ_FIRST(&zfs_pools);
794 if (dev->pool_guid == 0)
795 dev->pool_guid = spa->spa_guid;
797 spa = spa_find_by_guid(dev->pool_guid);
800 printf("ZFS: can't find pool by guid\n");
803 if (dev->root_guid == 0 && zfs_get_root(spa, &dev->root_guid)) {
804 printf("ZFS: can't find root filesystem\n");
807 if (zfs_rlookup(spa, dev->root_guid, rootname)) {
808 printf("ZFS: can't find filesystem by guid\n");
812 if (rootname[0] == '\0')
813 sprintf(buf, "%s:%s:", dev->dd.d_dev->dv_name, spa->spa_name);
815 sprintf(buf, "%s:%s/%s:", dev->dd.d_dev->dv_name, spa->spa_name,
821 zfs_list(const char *name)
823 static char poolname[ZFS_MAXNAMELEN];
831 dsname = strchr(name, '/');
832 if (dsname != NULL) {
837 memcpy(poolname, name, len);
838 poolname[len] = '\0';
840 spa = spa_find_by_name(poolname);
843 rv = zfs_lookup_dataset(spa, dsname, &objid);
847 return (zfs_list_dataset(spa, objid));
851 init_zfs_bootenv(const char *currdev_in)
853 char *beroot, *currdev;
857 currdev_len = strlen(currdev_in);
858 if (currdev_len == 0)
860 if (strncmp(currdev_in, "zfs:", 4) != 0)
862 currdev = strdup(currdev_in);
865 /* Remove the trailing : */
866 currdev[currdev_len - 1] = '\0';
867 setenv("zfs_be_active", currdev, 1);
868 setenv("zfs_be_currpage", "1", 1);
869 /* Remove the last element (current bootenv) */
870 beroot = strrchr(currdev, '/');
873 beroot = strchr(currdev, ':') + 1;
874 setenv("zfs_be_root", beroot, 1);
875 zfs_bootenv_initial(beroot);
880 zfs_bootenv_initial(const char *name)
882 char poolname[ZFS_MAXNAMELEN], *dsname;
883 char envname[32], envval[256];
886 int bootenvs_idx, len, rv;
888 SLIST_INIT(&zfs_be_head);
891 dsname = strchr(name, '/');
892 if (dsname != NULL) {
897 strlcpy(poolname, name, len + 1);
898 spa = spa_find_by_name(poolname);
901 rv = zfs_lookup_dataset(spa, dsname, &objid);
904 rv = zfs_callback_dataset(spa, objid, zfs_belist_add);
906 /* Populate the initial environment variables */
907 SLIST_FOREACH_SAFE(zfs_be, &zfs_be_head, entries, zfs_be_tmp) {
908 /* Enumerate all bootenvs for general usage */
909 snprintf(envname, sizeof(envname), "bootenvs[%d]", bootenvs_idx);
910 snprintf(envval, sizeof(envval), "zfs:%s/%s", name, zfs_be->name);
911 rv = setenv(envname, envval, 1);
916 snprintf(envval, sizeof(envval), "%d", bootenvs_idx);
917 setenv("bootenvs_count", envval, 1);
919 /* Clean up the SLIST of ZFS BEs */
920 while (!SLIST_EMPTY(&zfs_be_head)) {
921 zfs_be = SLIST_FIRST(&zfs_be_head);
922 SLIST_REMOVE_HEAD(&zfs_be_head, entries);
931 zfs_bootenv(const char *name)
933 static char poolname[ZFS_MAXNAMELEN], *dsname, *root;
937 int len, rv, pages, perpage, currpage;
941 if ((root = getenv("zfs_be_root")) == NULL)
944 if (strcmp(name, root) != 0) {
945 if (setenv("zfs_be_root", name, 1) != 0)
949 SLIST_INIT(&zfs_be_head);
952 dsname = strchr(name, '/');
953 if (dsname != NULL) {
958 memcpy(poolname, name, len);
959 poolname[len] = '\0';
961 spa = spa_find_by_name(poolname);
964 rv = zfs_lookup_dataset(spa, dsname, &objid);
967 rv = zfs_callback_dataset(spa, objid, zfs_belist_add);
969 /* Calculate and store the number of pages of BEs */
970 perpage = (ZFS_BE_LAST - ZFS_BE_FIRST + 1);
971 pages = (zfs_env_count / perpage) + ((zfs_env_count % perpage) > 0 ? 1 : 0);
972 snprintf(becount, 4, "%d", pages);
973 if (setenv("zfs_be_pages", becount, 1) != 0)
976 /* Roll over the page counter if it has exceeded the maximum */
977 currpage = strtol(getenv("zfs_be_currpage"), NULL, 10);
978 if (currpage > pages) {
979 if (setenv("zfs_be_currpage", "1", 1) != 0)
983 /* Populate the menu environment variables */
986 /* Clean up the SLIST of ZFS BEs */
987 while (!SLIST_EMPTY(&zfs_be_head)) {
988 zfs_be = SLIST_FIRST(&zfs_be_head);
989 SLIST_REMOVE_HEAD(&zfs_be_head, entries);
997 zfs_belist_add(const char *name, uint64_t value __unused)
1000 /* Skip special datasets that start with a $ character */
1001 if (strncmp(name, "$", 1) == 0) {
1004 /* Add the boot environment to the head of the SLIST */
1005 zfs_be = malloc(sizeof(struct zfs_be_entry));
1006 if (zfs_be == NULL) {
1009 zfs_be->name = name;
1010 SLIST_INSERT_HEAD(&zfs_be_head, zfs_be, entries);
1019 char envname[32], envval[256];
1020 char *beroot, *pagenum;
1023 beroot = getenv("zfs_be_root");
1024 if (beroot == NULL) {
1028 pagenum = getenv("zfs_be_currpage");
1029 if (pagenum != NULL) {
1030 page = strtol(pagenum, NULL, 10);
1037 zfs_env_index = ZFS_BE_FIRST;
1038 SLIST_FOREACH_SAFE(zfs_be, &zfs_be_head, entries, zfs_be_tmp) {
1039 /* Skip to the requested page number */
1040 if (ctr <= ((ZFS_BE_LAST - ZFS_BE_FIRST + 1) * (page - 1))) {
1045 snprintf(envname, sizeof(envname), "bootenvmenu_caption[%d]", zfs_env_index);
1046 snprintf(envval, sizeof(envval), "%s", zfs_be->name);
1047 rv = setenv(envname, envval, 1);
1052 snprintf(envname, sizeof(envname), "bootenvansi_caption[%d]", zfs_env_index);
1053 rv = setenv(envname, envval, 1);
1058 snprintf(envname, sizeof(envname), "bootenvmenu_command[%d]", zfs_env_index);
1059 rv = setenv(envname, "set_bootenv", 1);
1064 snprintf(envname, sizeof(envname), "bootenv_root[%d]", zfs_env_index);
1065 snprintf(envval, sizeof(envval), "zfs:%s/%s", beroot, zfs_be->name);
1066 rv = setenv(envname, envval, 1);
1072 if (zfs_env_index > ZFS_BE_LAST) {
1078 for (; zfs_env_index <= ZFS_BE_LAST; zfs_env_index++) {
1079 snprintf(envname, sizeof(envname), "bootenvmenu_caption[%d]", zfs_env_index);
1080 (void)unsetenv(envname);
1081 snprintf(envname, sizeof(envname), "bootenvansi_caption[%d]", zfs_env_index);
1082 (void)unsetenv(envname);
1083 snprintf(envname, sizeof(envname), "bootenvmenu_command[%d]", zfs_env_index);
1084 (void)unsetenv(envname);
1085 snprintf(envname, sizeof(envname), "bootenv_root[%d]", zfs_env_index);
1086 (void)unsetenv(envname);