zfsboot.c revision 234339 
1/*-
2 * Copyright (c) 1998 Robert Nordier
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms are freely
6 * permitted provided that the above copyright notice and this
7 * paragraph and the following disclaimer are duplicated in all
8 * such forms.
9 *
10 * This software is provided "AS IS" and without any express or
11 * implied warranties, including, without limitation, the implied
12 * warranties of merchantability and fitness for a particular
13 * purpose.
14 */
15
16#include <sys/cdefs.h>
17__FBSDID("$FreeBSD: head/sys/boot/i386/zfsboot/zfsboot.c 234339 2012-04-16 10:43:06Z avg $");
18
19#include <sys/param.h>
20#include <sys/errno.h>
21#include <sys/diskmbr.h>
22#ifdef GPT
23#include <sys/gpt.h>
24#endif
25#include <sys/reboot.h>
26#include <sys/queue.h>
27
28#include <machine/bootinfo.h>
29#include <machine/elf.h>
30#include <machine/pc/bios.h>
31
32#include <stdarg.h>
33#include <stddef.h>
34
35#include <a.out.h>
36
37#include <btxv86.h>
38
39#include "lib.h"
40#include "rbx.h"
41#include "drv.h"
42#include "util.h"
43#include "cons.h"
44
45/* Hint to loader that we came from ZFS */
46#define	KARGS_FLAGS_ZFS		0x4
47
48#define PATH_DOTCONFIG	"/boot.config"
49#define PATH_CONFIG	"/boot/config"
50#define PATH_BOOT3	"/boot/zfsloader"
51#define PATH_KERNEL	"/boot/kernel/kernel"
52
53#define ARGS		0x900
54#define NOPT		14
55#define NDEV		3
56
57#define BIOS_NUMDRIVES	0x475
58#define DRV_HARD	0x80
59#define DRV_MASK	0x7f
60
61#define TYPE_AD		0
62#define TYPE_DA		1
63#define TYPE_MAXHARD	TYPE_DA
64#define TYPE_FD		2
65
66#define	MAXBDDEV	31
67
68extern uint32_t _end;
69
70#ifdef GPT
71static const uuid_t freebsd_zfs_uuid = GPT_ENT_TYPE_FREEBSD_ZFS;
72#endif
73static const char optstr[NOPT] = "DhaCcdgmnpqrsv"; /* Also 'P', 'S' */
74static const unsigned char flags[NOPT] = {
75    RBX_DUAL,
76    RBX_SERIAL,
77    RBX_ASKNAME,
78    RBX_CDROM,
79    RBX_CONFIG,
80    RBX_KDB,
81    RBX_GDB,
82    RBX_MUTE,
83    RBX_NOINTR,
84    RBX_PAUSE,
85    RBX_QUIET,
86    RBX_DFLTROOT,
87    RBX_SINGLE,
88    RBX_VERBOSE
89};
90uint32_t opts;
91
92static const char *const dev_nm[NDEV] = {"ad", "da", "fd"};
93static const unsigned char dev_maj[NDEV] = {30, 4, 2};
94
95static char cmd[512];
96static char cmddup[512];
97static char kname[1024];
98static int comspeed = SIOSPD;
99static struct bootinfo bootinfo;
100static uint32_t bootdev;
101
102vm_offset_t	high_heap_base;
103uint32_t	bios_basemem, bios_extmem, high_heap_size;
104
105static struct bios_smap smap;
106
107/*
108 * The minimum amount of memory to reserve in bios_extmem for the heap.
109 */
110#define	HEAP_MIN	(3 * 1024 * 1024)
111
112static char *heap_next;
113static char *heap_end;
114
115/* Buffers that must not span a 64k boundary. */
116#define READ_BUF_SIZE	8192
117struct dmadat {
118	char rdbuf[READ_BUF_SIZE];	/* for reading large things */
119	char secbuf[READ_BUF_SIZE];	/* for MBR/disklabel */
120};
121static struct dmadat *dmadat;
122
123void exit(int);
124static void load(void);
125static int parse(void);
126static void bios_getmem(void);
127
128static void *
129malloc(size_t n)
130{
131	char *p = heap_next;
132	if (p + n > heap_end) {
133		printf("malloc failure\n");
134		for (;;)
135		    ;
136		return 0;
137	}
138	heap_next += n;
139	return p;
140}
141
142static char *
143strdup(const char *s)
144{
145	char *p = malloc(strlen(s) + 1);
146	strcpy(p, s);
147	return p;
148}
149
150#include "zfsimpl.c"
151
152/*
153 * Read from a dnode (which must be from a ZPL filesystem).
154 */
155static int
156zfs_read(spa_t *spa, const dnode_phys_t *dnode, off_t *offp, void *start, size_t size)
157{
158	const znode_phys_t *zp = (const znode_phys_t *) dnode->dn_bonus;
159	size_t n;
160	int rc;
161
162	n = size;
163	if (*offp + n > zp->zp_size)
164		n = zp->zp_size - *offp;
165
166	rc = dnode_read(spa, dnode, *offp, start, n);
167	if (rc)
168		return (-1);
169	*offp += n;
170
171	return (n);
172}
173
174/*
175 * Current ZFS pool
176 */
177spa_t *spa;
178
179/*
180 * A wrapper for dskread that doesn't have to worry about whether the
181 * buffer pointer crosses a 64k boundary.
182 */
183static int
184vdev_read(vdev_t *vdev, void *priv, off_t off, void *buf, size_t bytes)
185{
186	char *p;
187	daddr_t lba;
188	unsigned int nb;
189	struct dsk *dsk = (struct dsk *) priv;
190
191	if ((off & (DEV_BSIZE - 1)) || (bytes & (DEV_BSIZE - 1)))
192		return -1;
193
194	p = buf;
195	lba = off / DEV_BSIZE;
196	lba += dsk->start;
197	while (bytes > 0) {
198		nb = bytes / DEV_BSIZE;
199		if (nb > READ_BUF_SIZE / DEV_BSIZE)
200			nb = READ_BUF_SIZE / DEV_BSIZE;
201		if (drvread(dsk, dmadat->rdbuf, lba, nb))
202			return -1;
203		memcpy(p, dmadat->rdbuf, nb * DEV_BSIZE);
204		p += nb * DEV_BSIZE;
205		lba += nb;
206		bytes -= nb * DEV_BSIZE;
207	}
208
209	return 0;
210}
211
212static int
213xfsread(const dnode_phys_t *dnode, off_t *offp, void *buf, size_t nbyte)
214{
215    if ((size_t)zfs_read(spa, dnode, offp, buf, nbyte) != nbyte) {
216	printf("Invalid %s\n", "format");
217	return -1;
218    }
219    return 0;
220}
221
222static void
223bios_getmem(void)
224{
225    uint64_t size;
226
227    /* Parse system memory map */
228    v86.ebx = 0;
229    do {
230	v86.ctl = V86_FLAGS;
231	v86.addr = 0x15;		/* int 0x15 function 0xe820*/
232	v86.eax = 0xe820;
233	v86.ecx = sizeof(struct bios_smap);
234	v86.edx = SMAP_SIG;
235	v86.es = VTOPSEG(&smap);
236	v86.edi = VTOPOFF(&smap);
237	v86int();
238	if ((v86.efl & 1) || (v86.eax != SMAP_SIG))
239	    break;
240	/* look for a low-memory segment that's large enough */
241	if ((smap.type == SMAP_TYPE_MEMORY) && (smap.base == 0) &&
242	    (smap.length >= (512 * 1024)))
243	    bios_basemem = smap.length;
244	/* look for the first segment in 'extended' memory */
245	if ((smap.type == SMAP_TYPE_MEMORY) && (smap.base == 0x100000)) {
246	    bios_extmem = smap.length;
247	}
248
249	/*
250	 * Look for the largest segment in 'extended' memory beyond
251	 * 1MB but below 4GB.
252	 */
253	if ((smap.type == SMAP_TYPE_MEMORY) && (smap.base > 0x100000) &&
254	    (smap.base < 0x100000000ull)) {
255	    size = smap.length;
256
257	    /*
258	     * If this segment crosses the 4GB boundary, truncate it.
259	     */
260	    if (smap.base + size > 0x100000000ull)
261		size = 0x100000000ull - smap.base;
262
263	    if (size > high_heap_size) {
264		high_heap_size = size;
265		high_heap_base = smap.base;
266	    }
267	}
268    } while (v86.ebx != 0);
269
270    /* Fall back to the old compatibility function for base memory */
271    if (bios_basemem == 0) {
272	v86.ctl = 0;
273	v86.addr = 0x12;		/* int 0x12 */
274	v86int();
275
276	bios_basemem = (v86.eax & 0xffff) * 1024;
277    }
278
279    /* Fall back through several compatibility functions for extended memory */
280    if (bios_extmem == 0) {
281	v86.ctl = V86_FLAGS;
282	v86.addr = 0x15;		/* int 0x15 function 0xe801*/
283	v86.eax = 0xe801;
284	v86int();
285	if (!(v86.efl & 1)) {
286	    bios_extmem = ((v86.ecx & 0xffff) + ((v86.edx & 0xffff) * 64)) * 1024;
287	}
288    }
289    if (bios_extmem == 0) {
290	v86.ctl = 0;
291	v86.addr = 0x15;		/* int 0x15 function 0x88*/
292	v86.eax = 0x8800;
293	v86int();
294	bios_extmem = (v86.eax & 0xffff) * 1024;
295    }
296
297    /*
298     * If we have extended memory and did not find a suitable heap
299     * region in the SMAP, use the last 3MB of 'extended' memory as a
300     * high heap candidate.
301     */
302    if (bios_extmem >= HEAP_MIN && high_heap_size < HEAP_MIN) {
303	high_heap_size = HEAP_MIN;
304	high_heap_base = bios_extmem + 0x100000 - HEAP_MIN;
305    }
306}
307
308/*
309 * Try to detect a device supported by the legacy int13 BIOS
310 */
311static int
312int13probe(int drive)
313{
314    v86.ctl = V86_FLAGS;
315    v86.addr = 0x13;
316    v86.eax = 0x800;
317    v86.edx = drive;
318    v86int();
319
320    if (!(v86.efl & 0x1) &&				/* carry clear */
321	((v86.edx & 0xff) != (drive & DRV_MASK))) {	/* unit # OK */
322	if ((v86.ecx & 0x3f) == 0) {			/* absurd sector size */
323		return(0);				/* skip device */
324	}
325	return (1);
326    }
327    return(0);
328}
329
330/*
331 * We call this when we find a ZFS vdev - ZFS consumes the dsk
332 * structure so we must make a new one.
333 */
334static struct dsk *
335copy_dsk(struct dsk *dsk)
336{
337    struct dsk *newdsk;
338
339    newdsk = malloc(sizeof(struct dsk));
340    *newdsk = *dsk;
341    return (newdsk);
342}
343
344static void
345probe_drive(struct dsk *dsk, spa_t **spap)
346{
347#ifdef GPT
348    struct gpt_hdr hdr;
349    struct gpt_ent *ent;
350    daddr_t slba, elba;
351    unsigned part, entries_per_sec;
352#endif
353    struct dos_partition *dp;
354    char *sec;
355    unsigned i;
356
357    /*
358     * If we find a vdev on the whole disk, stop here. Otherwise dig
359     * out the MBR and probe each slice in turn for a vdev.
360     */
361    if (vdev_probe(vdev_read, dsk, spap) == 0)
362	return;
363
364    sec = dmadat->secbuf;
365    dsk->start = 0;
366
367#ifdef GPT
368    /*
369     * First check for GPT.
370     */
371    if (drvread(dsk, sec, 1, 1)) {
372	return;
373    }
374    memcpy(&hdr, sec, sizeof(hdr));
375    if (memcmp(hdr.hdr_sig, GPT_HDR_SIG, sizeof(hdr.hdr_sig)) != 0 ||
376	hdr.hdr_lba_self != 1 || hdr.hdr_revision < 0x00010000 ||
377	hdr.hdr_entsz < sizeof(*ent) || DEV_BSIZE % hdr.hdr_entsz != 0) {
378	goto trymbr;
379    }
380
381    /*
382     * Probe all GPT partitions for the presense of ZFS pools. We
383     * return the spa_t for the first we find (if requested). This
384     * will have the effect of booting from the first pool on the
385     * disk.
386     */
387    entries_per_sec = DEV_BSIZE / hdr.hdr_entsz;
388    slba = hdr.hdr_lba_table;
389    elba = slba + hdr.hdr_entries / entries_per_sec;
390    while (slba < elba) {
391	dsk->start = 0;
392	if (drvread(dsk, sec, slba, 1))
393	    return;
394	for (part = 0; part < entries_per_sec; part++) {
395	    ent = (struct gpt_ent *)(sec + part * hdr.hdr_entsz);
396	    if (memcmp(&ent->ent_type, &freebsd_zfs_uuid,
397		     sizeof(uuid_t)) == 0) {
398		dsk->start = ent->ent_lba_start;
399		if (vdev_probe(vdev_read, dsk, spap) == 0) {
400		    /*
401		     * We record the first pool we find (we will try
402		     * to boot from that one).
403		     */
404		    spap = NULL;
405
406		    /*
407		     * This slice had a vdev. We need a new dsk
408		     * structure now since the vdev now owns this one.
409		     */
410		    dsk = copy_dsk(dsk);
411		}
412	    }
413	}
414	slba++;
415    }
416    return;
417trymbr:
418#endif
419
420    if (drvread(dsk, sec, DOSBBSECTOR, 1))
421	return;
422    dp = (void *)(sec + DOSPARTOFF);
423
424    for (i = 0; i < NDOSPART; i++) {
425	if (!dp[i].dp_typ)
426	    continue;
427	dsk->start = dp[i].dp_start;
428	if (vdev_probe(vdev_read, dsk, spap) == 0) {
429	    /*
430	     * We record the first pool we find (we will try to boot
431	     * from that one.
432	     */
433	    spap = 0;
434
435	    /*
436	     * This slice had a vdev. We need a new dsk structure now
437	     * since the vdev now owns this one.
438	     */
439	    dsk = copy_dsk(dsk);
440	}
441    }
442}
443
444int
445main(void)
446{
447    int autoboot, i;
448    dnode_phys_t dn;
449    off_t off;
450    struct dsk *dsk;
451
452    dmadat = (void *)(roundup2(__base + (int32_t)&_end, 0x10000) - __base);
453
454    bios_getmem();
455
456    if (high_heap_size > 0) {
457	heap_end = PTOV(high_heap_base + high_heap_size);
458	heap_next = PTOV(high_heap_base);
459    } else {
460	heap_next = (char *) dmadat + sizeof(*dmadat);
461	heap_end = (char *) PTOV(bios_basemem);
462    }
463
464    dsk = malloc(sizeof(struct dsk));
465    dsk->drive = *(uint8_t *)PTOV(ARGS);
466    dsk->type = dsk->drive & DRV_HARD ? TYPE_AD : TYPE_FD;
467    dsk->unit = dsk->drive & DRV_MASK;
468    dsk->slice = *(uint8_t *)PTOV(ARGS + 1) + 1;
469    dsk->part = 0;
470    dsk->start = 0;
471    dsk->init = 0;
472
473    bootinfo.bi_version = BOOTINFO_VERSION;
474    bootinfo.bi_size = sizeof(bootinfo);
475    bootinfo.bi_basemem = bios_basemem / 1024;
476    bootinfo.bi_extmem = bios_extmem / 1024;
477    bootinfo.bi_memsizes_valid++;
478    bootinfo.bi_bios_dev = dsk->drive;
479
480    bootdev = MAKEBOOTDEV(dev_maj[dsk->type],
481			  dsk->slice, dsk->unit, dsk->part),
482
483    /* Process configuration file */
484
485    autoboot = 1;
486
487    zfs_init();
488
489    /*
490     * Probe the boot drive first - we will try to boot from whatever
491     * pool we find on that drive.
492     */
493    probe_drive(dsk, &spa);
494
495    /*
496     * Probe the rest of the drives that the bios knows about. This
497     * will find any other available pools and it may fill in missing
498     * vdevs for the boot pool.
499     */
500#ifndef VIRTUALBOX
501    for (i = 0; i < *(unsigned char *)PTOV(BIOS_NUMDRIVES); i++)
502#else
503    for (i = 0; i < MAXBDDEV; i++)
504#endif
505    {
506	if ((i | DRV_HARD) == *(uint8_t *)PTOV(ARGS))
507	    continue;
508
509	if (!int13probe(i | DRV_HARD))
510	    break;
511
512	dsk = malloc(sizeof(struct dsk));
513	dsk->drive = i | DRV_HARD;
514	dsk->type = dsk->drive & TYPE_AD;
515	dsk->unit = i;
516	dsk->slice = 0;
517	dsk->part = 0;
518	dsk->start = 0;
519	dsk->init = 0;
520	probe_drive(dsk, NULL);
521    }
522
523    /*
524     * If we didn't find a pool on the boot drive, default to the
525     * first pool we found, if any.
526     */
527    if (!spa) {
528	spa = STAILQ_FIRST(&zfs_pools);
529	if (!spa) {
530	    printf("%s: No ZFS pools located, can't boot\n", BOOTPROG);
531	    for (;;)
532		;
533	}
534    }
535
536    zfs_mount_pool(spa);
537
538    if (zfs_lookup(spa, PATH_CONFIG, &dn) == 0 ||
539        zfs_lookup(spa, PATH_DOTCONFIG, &dn) == 0) {
540	off = 0;
541	zfs_read(spa, &dn, &off, cmd, sizeof(cmd));
542    }
543
544    if (*cmd) {
545	/*
546	 * Note that parse() is destructive to cmd[] and we also want
547	 * to honor RBX_QUIET option that could be present in cmd[].
548	 */
549	memcpy(cmddup, cmd, sizeof(cmd));
550	if (parse())
551	    autoboot = 0;
552	if (!OPT_CHECK(RBX_QUIET))
553	    printf("%s: %s", PATH_CONFIG, cmddup);
554	/* Do not process this command twice */
555	*cmd = 0;
556    }
557
558    /*
559     * Try to exec stage 3 boot loader. If interrupted by a keypress,
560     * or in case of failure, try to load a kernel directly instead.
561     */
562
563    if (autoboot && !*kname) {
564	memcpy(kname, PATH_BOOT3, sizeof(PATH_BOOT3));
565	if (!keyhit(3)) {
566	    load();
567	    memcpy(kname, PATH_KERNEL, sizeof(PATH_KERNEL));
568	}
569    }
570
571    /* Present the user with the boot2 prompt. */
572
573    for (;;) {
574	if (!autoboot || !OPT_CHECK(RBX_QUIET))
575	    printf("\nFreeBSD/x86 boot\n"
576		   "Default: %s:%s\n"
577		   "boot: ",
578		   spa->spa_name, kname);
579	if (ioctrl & IO_SERIAL)
580	    sio_flush();
581	if (!autoboot || keyhit(5))
582	    getstr(cmd, sizeof(cmd));
583	else if (!autoboot || !OPT_CHECK(RBX_QUIET))
584	    putchar('\n');
585	autoboot = 0;
586	if (parse())
587	    putchar('\a');
588	else
589	    load();
590    }
591}
592
593/* XXX - Needed for btxld to link the boot2 binary; do not remove. */
594void
595exit(int x)
596{
597}
598
599static void
600load(void)
601{
602    union {
603	struct exec ex;
604	Elf32_Ehdr eh;
605    } hdr;
606    static Elf32_Phdr ep[2];
607    static Elf32_Shdr es[2];
608    caddr_t p;
609    dnode_phys_t dn;
610    off_t off;
611    uint32_t addr, x;
612    int fmt, i, j;
613
614    if (zfs_lookup(spa, kname, &dn)) {
615	return;
616    }
617    off = 0;
618    if (xfsread(&dn, &off, &hdr, sizeof(hdr)))
619	return;
620    if (N_GETMAGIC(hdr.ex) == ZMAGIC)
621	fmt = 0;
622    else if (IS_ELF(hdr.eh))
623	fmt = 1;
624    else {
625	printf("Invalid %s\n", "format");
626	return;
627    }
628    if (fmt == 0) {
629	addr = hdr.ex.a_entry & 0xffffff;
630	p = PTOV(addr);
631	off = PAGE_SIZE;
632	if (xfsread(&dn, &off, p, hdr.ex.a_text))
633	    return;
634	p += roundup2(hdr.ex.a_text, PAGE_SIZE);
635	if (xfsread(&dn, &off, p, hdr.ex.a_data))
636	    return;
637	p += hdr.ex.a_data + roundup2(hdr.ex.a_bss, PAGE_SIZE);
638	bootinfo.bi_symtab = VTOP(p);
639	memcpy(p, &hdr.ex.a_syms, sizeof(hdr.ex.a_syms));
640	p += sizeof(hdr.ex.a_syms);
641	if (hdr.ex.a_syms) {
642	    if (xfsread(&dn, &off, p, hdr.ex.a_syms))
643		return;
644	    p += hdr.ex.a_syms;
645	    if (xfsread(&dn, &off, p, sizeof(int)))
646		return;
647	    x = *(uint32_t *)p;
648	    p += sizeof(int);
649	    x -= sizeof(int);
650	    if (xfsread(&dn, &off, p, x))
651		return;
652	    p += x;
653	}
654    } else {
655	off = hdr.eh.e_phoff;
656	for (j = i = 0; i < hdr.eh.e_phnum && j < 2; i++) {
657	    if (xfsread(&dn, &off, ep + j, sizeof(ep[0])))
658		return;
659	    if (ep[j].p_type == PT_LOAD)
660		j++;
661	}
662	for (i = 0; i < 2; i++) {
663	    p = PTOV(ep[i].p_paddr & 0xffffff);
664	    off = ep[i].p_offset;
665	    if (xfsread(&dn, &off, p, ep[i].p_filesz))
666		return;
667	}
668	p += roundup2(ep[1].p_memsz, PAGE_SIZE);
669	bootinfo.bi_symtab = VTOP(p);
670	if (hdr.eh.e_shnum == hdr.eh.e_shstrndx + 3) {
671	    off = hdr.eh.e_shoff + sizeof(es[0]) *
672		(hdr.eh.e_shstrndx + 1);
673	    if (xfsread(&dn, &off, &es, sizeof(es)))
674		return;
675	    for (i = 0; i < 2; i++) {
676		memcpy(p, &es[i].sh_size, sizeof(es[i].sh_size));
677		p += sizeof(es[i].sh_size);
678		off = es[i].sh_offset;
679		if (xfsread(&dn, &off, p, es[i].sh_size))
680		    return;
681		p += es[i].sh_size;
682	    }
683	}
684	addr = hdr.eh.e_entry & 0xffffff;
685    }
686    bootinfo.bi_esymtab = VTOP(p);
687    bootinfo.bi_kernelname = VTOP(kname);
688    __exec((caddr_t)addr, RB_BOOTINFO | (opts & RBX_MASK),
689	   bootdev,
690	   KARGS_FLAGS_ZFS,
691	   (uint32_t) spa->spa_guid,
692	   (uint32_t) (spa->spa_guid >> 32),
693	   VTOP(&bootinfo));
694}
695
696static int
697parse(void)
698{
699    char *arg = cmd;
700    char *ep, *p, *q;
701    const char *cp;
702    //unsigned int drv;
703    int c, i, j;
704
705    while ((c = *arg++)) {
706	if (c == ' ' || c == '\t' || c == '\n')
707	    continue;
708	for (p = arg; *p && *p != '\n' && *p != ' ' && *p != '\t'; p++);
709	ep = p;
710	if (*p)
711	    *p++ = 0;
712	if (c == '-') {
713	    while ((c = *arg++)) {
714		if (c == 'P') {
715		    if (*(uint8_t *)PTOV(0x496) & 0x10) {
716			cp = "yes";
717		    } else {
718			opts |= OPT_SET(RBX_DUAL) | OPT_SET(RBX_SERIAL);
719			cp = "no";
720		    }
721		    printf("Keyboard: %s\n", cp);
722		    continue;
723		} else if (c == 'S') {
724		    j = 0;
725		    while ((unsigned int)(i = *arg++ - '0') <= 9)
726			j = j * 10 + i;
727		    if (j > 0 && i == -'0') {
728			comspeed = j;
729			break;
730		    }
731		    /* Fall through to error below ('S' not in optstr[]). */
732		}
733		for (i = 0; c != optstr[i]; i++)
734		    if (i == NOPT - 1)
735			return -1;
736		opts ^= OPT_SET(flags[i]);
737	    }
738	    ioctrl = OPT_CHECK(RBX_DUAL) ? (IO_SERIAL|IO_KEYBOARD) :
739		     OPT_CHECK(RBX_SERIAL) ? IO_SERIAL : IO_KEYBOARD;
740	    if (ioctrl & IO_SERIAL)
741	        sio_init(115200 / comspeed);
742	} if (c == '?') {
743	    dnode_phys_t dn;
744
745	    if (zfs_lookup(spa, arg, &dn) == 0) {
746		zap_list(spa, &dn);
747	    }
748	    return -1;
749	} else {
750	    arg--;
751
752	    /*
753	     * Report pool status if the comment is 'status'. Lets
754	     * hope no-one wants to load /status as a kernel.
755	     */
756	    if (!strcmp(arg, "status")) {
757		spa_all_status();
758		return -1;
759	    }
760
761	    /*
762	     * If there is a colon, switch pools.
763	     */
764	    q = (char *) strchr(arg, ':');
765	    if (q) {
766		spa_t *newspa;
767
768		*q++ = 0;
769		newspa = spa_find_by_name(arg);
770		if (newspa) {
771		    spa = newspa;
772		    zfs_mount_pool(spa);
773		} else {
774		    printf("\nCan't find ZFS pool %s\n", arg);
775		    return -1;
776		}
777		arg = q;
778	    }
779	    if ((i = ep - arg)) {
780		if ((size_t)i >= sizeof(kname))
781		    return -1;
782		memcpy(kname, arg, i + 1);
783	    }
784	}
785	arg = p;
786    }
787    return 0;
788}
789