xref: /illumos-gate/usr/src/lib/libzpool/common/kernel.c (revision c2785286330b58810071fc24f6ca69f401682dff)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*
22  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 #pragma ident	"%Z%%M%	%I%	%E% SMI"
27 
28 #include <assert.h>
29 #include <fcntl.h>
30 #include <poll.h>
31 #include <stdio.h>
32 #include <stdlib.h>
33 #include <string.h>
34 #include <zlib.h>
35 #include <sys/spa.h>
36 #include <sys/stat.h>
37 #include <sys/processor.h>
38 #include <sys/zfs_context.h>
39 #include <sys/zmod.h>
40 #include <sys/utsname.h>
41 
42 /*
43  * Emulation of kernel services in userland.
44  */
45 
46 uint64_t physmem;
47 vnode_t *rootdir = (vnode_t *)0xabcd1234;
48 char hw_serial[11];
49 
50 struct utsname utsname = {
51 	"userland", "libzpool", "1", "1", "na"
52 };
53 
54 /*
55  * =========================================================================
56  * threads
57  * =========================================================================
58  */
59 /*ARGSUSED*/
60 kthread_t *
61 zk_thread_create(void (*func)(), void *arg)
62 {
63 	thread_t tid;
64 
65 	VERIFY(thr_create(0, 0, (void *(*)(void *))func, arg, THR_DETACHED,
66 	    &tid) == 0);
67 
68 	return ((void *)(uintptr_t)tid);
69 }
70 
71 /*
72  * =========================================================================
73  * kstats
74  * =========================================================================
75  */
76 /*ARGSUSED*/
77 kstat_t *
78 kstat_create(char *module, int instance, char *name, char *class,
79     uchar_t type, ulong_t ndata, uchar_t ks_flag)
80 {
81 	return (NULL);
82 }
83 
84 /*ARGSUSED*/
85 void
86 kstat_install(kstat_t *ksp)
87 {}
88 
89 /*ARGSUSED*/
90 void
91 kstat_delete(kstat_t *ksp)
92 {}
93 
94 /*
95  * =========================================================================
96  * mutexes
97  * =========================================================================
98  */
99 void
100 zmutex_init(kmutex_t *mp)
101 {
102 	mp->m_owner = NULL;
103 	mp->initialized = B_TRUE;
104 	(void) _mutex_init(&mp->m_lock, USYNC_THREAD, NULL);
105 }
106 
107 void
108 zmutex_destroy(kmutex_t *mp)
109 {
110 	ASSERT(mp->initialized == B_TRUE);
111 	ASSERT(mp->m_owner == NULL);
112 	(void) _mutex_destroy(&(mp)->m_lock);
113 	mp->m_owner = (void *)-1UL;
114 	mp->initialized = B_FALSE;
115 }
116 
117 void
118 mutex_enter(kmutex_t *mp)
119 {
120 	ASSERT(mp->initialized == B_TRUE);
121 	ASSERT(mp->m_owner != (void *)-1UL);
122 	ASSERT(mp->m_owner != curthread);
123 	VERIFY(mutex_lock(&mp->m_lock) == 0);
124 	ASSERT(mp->m_owner == NULL);
125 	mp->m_owner = curthread;
126 }
127 
128 int
129 mutex_tryenter(kmutex_t *mp)
130 {
131 	ASSERT(mp->initialized == B_TRUE);
132 	ASSERT(mp->m_owner != (void *)-1UL);
133 	if (0 == mutex_trylock(&mp->m_lock)) {
134 		ASSERT(mp->m_owner == NULL);
135 		mp->m_owner = curthread;
136 		return (1);
137 	} else {
138 		return (0);
139 	}
140 }
141 
142 void
143 mutex_exit(kmutex_t *mp)
144 {
145 	ASSERT(mp->initialized == B_TRUE);
146 	ASSERT(mutex_owner(mp) == curthread);
147 	mp->m_owner = NULL;
148 	VERIFY(mutex_unlock(&mp->m_lock) == 0);
149 }
150 
151 void *
152 mutex_owner(kmutex_t *mp)
153 {
154 	ASSERT(mp->initialized == B_TRUE);
155 	return (mp->m_owner);
156 }
157 
158 /*
159  * =========================================================================
160  * rwlocks
161  * =========================================================================
162  */
163 /*ARGSUSED*/
164 void
165 rw_init(krwlock_t *rwlp, char *name, int type, void *arg)
166 {
167 	rwlock_init(&rwlp->rw_lock, USYNC_THREAD, NULL);
168 	rwlp->rw_owner = NULL;
169 	rwlp->initialized = B_TRUE;
170 }
171 
172 void
173 rw_destroy(krwlock_t *rwlp)
174 {
175 	rwlock_destroy(&rwlp->rw_lock);
176 	rwlp->rw_owner = (void *)-1UL;
177 	rwlp->initialized = B_FALSE;
178 }
179 
180 void
181 rw_enter(krwlock_t *rwlp, krw_t rw)
182 {
183 	ASSERT(!RW_LOCK_HELD(rwlp));
184 	ASSERT(rwlp->initialized == B_TRUE);
185 	ASSERT(rwlp->rw_owner != (void *)-1UL);
186 	ASSERT(rwlp->rw_owner != curthread);
187 
188 	if (rw == RW_READER)
189 		VERIFY(rw_rdlock(&rwlp->rw_lock) == 0);
190 	else
191 		VERIFY(rw_wrlock(&rwlp->rw_lock) == 0);
192 
193 	rwlp->rw_owner = curthread;
194 }
195 
196 void
197 rw_exit(krwlock_t *rwlp)
198 {
199 	ASSERT(rwlp->initialized == B_TRUE);
200 	ASSERT(rwlp->rw_owner != (void *)-1UL);
201 
202 	rwlp->rw_owner = NULL;
203 	VERIFY(rw_unlock(&rwlp->rw_lock) == 0);
204 }
205 
206 int
207 rw_tryenter(krwlock_t *rwlp, krw_t rw)
208 {
209 	int rv;
210 
211 	ASSERT(rwlp->initialized == B_TRUE);
212 	ASSERT(rwlp->rw_owner != (void *)-1UL);
213 
214 	if (rw == RW_READER)
215 		rv = rw_tryrdlock(&rwlp->rw_lock);
216 	else
217 		rv = rw_trywrlock(&rwlp->rw_lock);
218 
219 	if (rv == 0) {
220 		rwlp->rw_owner = curthread;
221 		return (1);
222 	}
223 
224 	return (0);
225 }
226 
227 /*ARGSUSED*/
228 int
229 rw_tryupgrade(krwlock_t *rwlp)
230 {
231 	ASSERT(rwlp->initialized == B_TRUE);
232 	ASSERT(rwlp->rw_owner != (void *)-1UL);
233 
234 	return (0);
235 }
236 
237 /*
238  * =========================================================================
239  * condition variables
240  * =========================================================================
241  */
242 /*ARGSUSED*/
243 void
244 cv_init(kcondvar_t *cv, char *name, int type, void *arg)
245 {
246 	VERIFY(cond_init(cv, type, NULL) == 0);
247 }
248 
249 void
250 cv_destroy(kcondvar_t *cv)
251 {
252 	VERIFY(cond_destroy(cv) == 0);
253 }
254 
255 void
256 cv_wait(kcondvar_t *cv, kmutex_t *mp)
257 {
258 	ASSERT(mutex_owner(mp) == curthread);
259 	mp->m_owner = NULL;
260 	int ret = cond_wait(cv, &mp->m_lock);
261 	VERIFY(ret == 0 || ret == EINTR);
262 	mp->m_owner = curthread;
263 }
264 
265 clock_t
266 cv_timedwait(kcondvar_t *cv, kmutex_t *mp, clock_t abstime)
267 {
268 	int error;
269 	timestruc_t ts;
270 	clock_t delta;
271 
272 top:
273 	delta = abstime - lbolt;
274 	if (delta <= 0)
275 		return (-1);
276 
277 	ts.tv_sec = delta / hz;
278 	ts.tv_nsec = (delta % hz) * (NANOSEC / hz);
279 
280 	ASSERT(mutex_owner(mp) == curthread);
281 	mp->m_owner = NULL;
282 	error = cond_reltimedwait(cv, &mp->m_lock, &ts);
283 	mp->m_owner = curthread;
284 
285 	if (error == ETIME)
286 		return (-1);
287 
288 	if (error == EINTR)
289 		goto top;
290 
291 	ASSERT(error == 0);
292 
293 	return (1);
294 }
295 
296 void
297 cv_signal(kcondvar_t *cv)
298 {
299 	VERIFY(cond_signal(cv) == 0);
300 }
301 
302 void
303 cv_broadcast(kcondvar_t *cv)
304 {
305 	VERIFY(cond_broadcast(cv) == 0);
306 }
307 
308 /*
309  * =========================================================================
310  * vnode operations
311  * =========================================================================
312  */
313 /*
314  * Note: for the xxxat() versions of these functions, we assume that the
315  * starting vp is always rootdir (which is true for spa_directory.c, the only
316  * ZFS consumer of these interfaces).  We assert this is true, and then emulate
317  * them by adding '/' in front of the path.
318  */
319 
320 /*ARGSUSED*/
321 int
322 vn_open(char *path, int x1, int flags, int mode, vnode_t **vpp, int x2, int x3)
323 {
324 	int fd;
325 	vnode_t *vp;
326 	int old_umask;
327 	char realpath[MAXPATHLEN];
328 	struct stat64 st;
329 
330 	/*
331 	 * If we're accessing a real disk from userland, we need to use
332 	 * the character interface to avoid caching.  This is particularly
333 	 * important if we're trying to look at a real in-kernel storage
334 	 * pool from userland, e.g. via zdb, because otherwise we won't
335 	 * see the changes occurring under the segmap cache.
336 	 * On the other hand, the stupid character device returns zero
337 	 * for its size.  So -- gag -- we open the block device to get
338 	 * its size, and remember it for subsequent VOP_GETATTR().
339 	 */
340 	if (strncmp(path, "/dev/", 5) == 0) {
341 		char *dsk;
342 		fd = open64(path, O_RDONLY);
343 		if (fd == -1)
344 			return (errno);
345 		if (fstat64(fd, &st) == -1) {
346 			close(fd);
347 			return (errno);
348 		}
349 		close(fd);
350 		(void) sprintf(realpath, "%s", path);
351 		dsk = strstr(path, "/dsk/");
352 		if (dsk != NULL)
353 			(void) sprintf(realpath + (dsk - path) + 1, "r%s",
354 			    dsk + 1);
355 	} else {
356 		(void) sprintf(realpath, "%s", path);
357 		if (!(flags & FCREAT) && stat64(realpath, &st) == -1)
358 			return (errno);
359 	}
360 
361 	if (flags & FCREAT)
362 		old_umask = umask(0);
363 
364 	/*
365 	 * The construct 'flags - FREAD' conveniently maps combinations of
366 	 * FREAD and FWRITE to the corresponding O_RDONLY, O_WRONLY, and O_RDWR.
367 	 */
368 	fd = open64(realpath, flags - FREAD, mode);
369 
370 	if (flags & FCREAT)
371 		(void) umask(old_umask);
372 
373 	if (fd == -1)
374 		return (errno);
375 
376 	if (fstat64(fd, &st) == -1) {
377 		close(fd);
378 		return (errno);
379 	}
380 
381 	(void) fcntl(fd, F_SETFD, FD_CLOEXEC);
382 
383 	*vpp = vp = umem_zalloc(sizeof (vnode_t), UMEM_NOFAIL);
384 
385 	vp->v_fd = fd;
386 	vp->v_size = st.st_size;
387 	vp->v_path = spa_strdup(path);
388 
389 	return (0);
390 }
391 
392 /*ARGSUSED*/
393 int
394 vn_openat(char *path, int x1, int flags, int mode, vnode_t **vpp, int x2,
395     int x3, vnode_t *startvp, int fd)
396 {
397 	char *realpath = umem_alloc(strlen(path) + 2, UMEM_NOFAIL);
398 	int ret;
399 
400 	ASSERT(startvp == rootdir);
401 	(void) sprintf(realpath, "/%s", path);
402 
403 	/* fd ignored for now, need if want to simulate nbmand support */
404 	ret = vn_open(realpath, x1, flags, mode, vpp, x2, x3);
405 
406 	umem_free(realpath, strlen(path) + 2);
407 
408 	return (ret);
409 }
410 
411 /*ARGSUSED*/
412 int
413 vn_rdwr(int uio, vnode_t *vp, void *addr, ssize_t len, offset_t offset,
414 	int x1, int x2, rlim64_t x3, void *x4, ssize_t *residp)
415 {
416 	ssize_t iolen, split;
417 
418 	if (uio == UIO_READ) {
419 		iolen = pread64(vp->v_fd, addr, len, offset);
420 	} else {
421 		/*
422 		 * To simulate partial disk writes, we split writes into two
423 		 * system calls so that the process can be killed in between.
424 		 */
425 		split = (len > 0 ? rand() % len : 0);
426 		iolen = pwrite64(vp->v_fd, addr, split, offset);
427 		iolen += pwrite64(vp->v_fd, (char *)addr + split,
428 		    len - split, offset + split);
429 	}
430 
431 	if (iolen == -1)
432 		return (errno);
433 	if (residp)
434 		*residp = len - iolen;
435 	else if (iolen != len)
436 		return (EIO);
437 	return (0);
438 }
439 
440 void
441 vn_close(vnode_t *vp)
442 {
443 	close(vp->v_fd);
444 	spa_strfree(vp->v_path);
445 	umem_free(vp, sizeof (vnode_t));
446 }
447 
448 #ifdef ZFS_DEBUG
449 
450 /*
451  * =========================================================================
452  * Figure out which debugging statements to print
453  * =========================================================================
454  */
455 
456 static char *dprintf_string;
457 static int dprintf_print_all;
458 
459 int
460 dprintf_find_string(const char *string)
461 {
462 	char *tmp_str = dprintf_string;
463 	int len = strlen(string);
464 
465 	/*
466 	 * Find out if this is a string we want to print.
467 	 * String format: file1.c,function_name1,file2.c,file3.c
468 	 */
469 
470 	while (tmp_str != NULL) {
471 		if (strncmp(tmp_str, string, len) == 0 &&
472 		    (tmp_str[len] == ',' || tmp_str[len] == '\0'))
473 			return (1);
474 		tmp_str = strchr(tmp_str, ',');
475 		if (tmp_str != NULL)
476 			tmp_str++; /* Get rid of , */
477 	}
478 	return (0);
479 }
480 
481 void
482 dprintf_setup(int *argc, char **argv)
483 {
484 	int i, j;
485 
486 	/*
487 	 * Debugging can be specified two ways: by setting the
488 	 * environment variable ZFS_DEBUG, or by including a
489 	 * "debug=..."  argument on the command line.  The command
490 	 * line setting overrides the environment variable.
491 	 */
492 
493 	for (i = 1; i < *argc; i++) {
494 		int len = strlen("debug=");
495 		/* First look for a command line argument */
496 		if (strncmp("debug=", argv[i], len) == 0) {
497 			dprintf_string = argv[i] + len;
498 			/* Remove from args */
499 			for (j = i; j < *argc; j++)
500 				argv[j] = argv[j+1];
501 			argv[j] = NULL;
502 			(*argc)--;
503 		}
504 	}
505 
506 	if (dprintf_string == NULL) {
507 		/* Look for ZFS_DEBUG environment variable */
508 		dprintf_string = getenv("ZFS_DEBUG");
509 	}
510 
511 	/*
512 	 * Are we just turning on all debugging?
513 	 */
514 	if (dprintf_find_string("on"))
515 		dprintf_print_all = 1;
516 }
517 
518 /*
519  * =========================================================================
520  * debug printfs
521  * =========================================================================
522  */
523 void
524 __dprintf(const char *file, const char *func, int line, const char *fmt, ...)
525 {
526 	const char *newfile;
527 	va_list adx;
528 
529 	/*
530 	 * Get rid of annoying "../common/" prefix to filename.
531 	 */
532 	newfile = strrchr(file, '/');
533 	if (newfile != NULL) {
534 		newfile = newfile + 1; /* Get rid of leading / */
535 	} else {
536 		newfile = file;
537 	}
538 
539 	if (dprintf_print_all ||
540 	    dprintf_find_string(newfile) ||
541 	    dprintf_find_string(func)) {
542 		/* Print out just the function name if requested */
543 		flockfile(stdout);
544 		if (dprintf_find_string("pid"))
545 			(void) printf("%d ", getpid());
546 		if (dprintf_find_string("tid"))
547 			(void) printf("%u ", thr_self());
548 		if (dprintf_find_string("cpu"))
549 			(void) printf("%u ", getcpuid());
550 		if (dprintf_find_string("time"))
551 			(void) printf("%llu ", gethrtime());
552 		if (dprintf_find_string("long"))
553 			(void) printf("%s, line %d: ", newfile, line);
554 		(void) printf("%s: ", func);
555 		va_start(adx, fmt);
556 		(void) vprintf(fmt, adx);
557 		va_end(adx);
558 		funlockfile(stdout);
559 	}
560 }
561 
562 #endif /* ZFS_DEBUG */
563 
564 /*
565  * =========================================================================
566  * cmn_err() and panic()
567  * =========================================================================
568  */
569 static char ce_prefix[CE_IGNORE][10] = { "", "NOTICE: ", "WARNING: ", "" };
570 static char ce_suffix[CE_IGNORE][2] = { "", "\n", "\n", "" };
571 
572 void
573 vpanic(const char *fmt, va_list adx)
574 {
575 	(void) fprintf(stderr, "error: ");
576 	(void) vfprintf(stderr, fmt, adx);
577 	(void) fprintf(stderr, "\n");
578 
579 	abort();	/* think of it as a "user-level crash dump" */
580 }
581 
582 void
583 panic(const char *fmt, ...)
584 {
585 	va_list adx;
586 
587 	va_start(adx, fmt);
588 	vpanic(fmt, adx);
589 	va_end(adx);
590 }
591 
592 void
593 vcmn_err(int ce, const char *fmt, va_list adx)
594 {
595 	if (ce == CE_PANIC)
596 		vpanic(fmt, adx);
597 	if (ce != CE_NOTE) {	/* suppress noise in userland stress testing */
598 		(void) fprintf(stderr, "%s", ce_prefix[ce]);
599 		(void) vfprintf(stderr, fmt, adx);
600 		(void) fprintf(stderr, "%s", ce_suffix[ce]);
601 	}
602 }
603 
604 /*PRINTFLIKE2*/
605 void
606 cmn_err(int ce, const char *fmt, ...)
607 {
608 	va_list adx;
609 
610 	va_start(adx, fmt);
611 	vcmn_err(ce, fmt, adx);
612 	va_end(adx);
613 }
614 
615 /*
616  * =========================================================================
617  * kobj interfaces
618  * =========================================================================
619  */
620 struct _buf *
621 kobj_open_file(char *name)
622 {
623 	struct _buf *file;
624 	vnode_t *vp;
625 
626 	/* set vp as the _fd field of the file */
627 	if (vn_openat(name, UIO_SYSSPACE, FREAD, 0, &vp, 0, 0, rootdir,
628 	    -1) != 0)
629 		return ((void *)-1UL);
630 
631 	file = umem_zalloc(sizeof (struct _buf), UMEM_NOFAIL);
632 	file->_fd = (intptr_t)vp;
633 	return (file);
634 }
635 
636 int
637 kobj_read_file(struct _buf *file, char *buf, unsigned size, unsigned off)
638 {
639 	ssize_t resid;
640 
641 	vn_rdwr(UIO_READ, (vnode_t *)file->_fd, buf, size, (offset_t)off,
642 	    UIO_SYSSPACE, 0, 0, 0, &resid);
643 
644 	return (size - resid);
645 }
646 
647 void
648 kobj_close_file(struct _buf *file)
649 {
650 	vn_close((vnode_t *)file->_fd);
651 	umem_free(file, sizeof (struct _buf));
652 }
653 
654 int
655 kobj_get_filesize(struct _buf *file, uint64_t *size)
656 {
657 	struct stat64 st;
658 	vnode_t *vp = (vnode_t *)file->_fd;
659 
660 	if (fstat64(vp->v_fd, &st) == -1) {
661 		vn_close(vp);
662 		return (errno);
663 	}
664 	*size = st.st_size;
665 	return (0);
666 }
667 
668 /*
669  * =========================================================================
670  * misc routines
671  * =========================================================================
672  */
673 
674 void
675 delay(clock_t ticks)
676 {
677 	poll(0, 0, ticks * (1000 / hz));
678 }
679 
680 /*
681  * Find highest one bit set.
682  *	Returns bit number + 1 of highest bit that is set, otherwise returns 0.
683  * High order bit is 31 (or 63 in _LP64 kernel).
684  */
685 int
686 highbit(ulong_t i)
687 {
688 	register int h = 1;
689 
690 	if (i == 0)
691 		return (0);
692 #ifdef _LP64
693 	if (i & 0xffffffff00000000ul) {
694 		h += 32; i >>= 32;
695 	}
696 #endif
697 	if (i & 0xffff0000) {
698 		h += 16; i >>= 16;
699 	}
700 	if (i & 0xff00) {
701 		h += 8; i >>= 8;
702 	}
703 	if (i & 0xf0) {
704 		h += 4; i >>= 4;
705 	}
706 	if (i & 0xc) {
707 		h += 2; i >>= 2;
708 	}
709 	if (i & 0x2) {
710 		h += 1;
711 	}
712 	return (h);
713 }
714 
715 static int random_fd = -1, urandom_fd = -1;
716 
717 static int
718 random_get_bytes_common(uint8_t *ptr, size_t len, int fd)
719 {
720 	size_t resid = len;
721 	ssize_t bytes;
722 
723 	ASSERT(fd != -1);
724 
725 	while (resid != 0) {
726 		bytes = read(fd, ptr, resid);
727 		ASSERT3S(bytes, >=, 0);
728 		ptr += bytes;
729 		resid -= bytes;
730 	}
731 
732 	return (0);
733 }
734 
735 int
736 random_get_bytes(uint8_t *ptr, size_t len)
737 {
738 	return (random_get_bytes_common(ptr, len, random_fd));
739 }
740 
741 int
742 random_get_pseudo_bytes(uint8_t *ptr, size_t len)
743 {
744 	return (random_get_bytes_common(ptr, len, urandom_fd));
745 }
746 
747 int
748 ddi_strtoul(const char *hw_serial, char **nptr, int base, unsigned long *result)
749 {
750 	char *end;
751 
752 	*result = strtoul(hw_serial, &end, base);
753 	if (*result == 0)
754 		return (errno);
755 	return (0);
756 }
757 
758 /*
759  * =========================================================================
760  * kernel emulation setup & teardown
761  * =========================================================================
762  */
763 static int
764 umem_out_of_memory(void)
765 {
766 	char errmsg[] = "out of memory -- generating core dump\n";
767 
768 	write(fileno(stderr), errmsg, sizeof (errmsg));
769 	abort();
770 	return (0);
771 }
772 
773 void
774 kernel_init(int mode)
775 {
776 	umem_nofail_callback(umem_out_of_memory);
777 
778 	physmem = sysconf(_SC_PHYS_PAGES);
779 
780 	dprintf("physmem = %llu pages (%.2f GB)\n", physmem,
781 	    (double)physmem * sysconf(_SC_PAGE_SIZE) / (1ULL << 30));
782 
783 	snprintf(hw_serial, sizeof (hw_serial), "%ld", gethostid());
784 
785 	VERIFY((random_fd = open("/dev/random", O_RDONLY)) != -1);
786 	VERIFY((urandom_fd = open("/dev/urandom", O_RDONLY)) != -1);
787 
788 	spa_init(mode);
789 }
790 
791 void
792 kernel_fini(void)
793 {
794 	spa_fini();
795 
796 	close(random_fd);
797 	close(urandom_fd);
798 
799 	random_fd = -1;
800 	urandom_fd = -1;
801 }
802 
803 int
804 z_uncompress(void *dst, size_t *dstlen, const void *src, size_t srclen)
805 {
806 	int ret;
807 	uLongf len = *dstlen;
808 
809 	if ((ret = uncompress(dst, &len, src, srclen)) == Z_OK)
810 		*dstlen = (size_t)len;
811 
812 	return (ret);
813 }
814 
815 int
816 z_compress_level(void *dst, size_t *dstlen, const void *src, size_t srclen,
817     int level)
818 {
819 	int ret;
820 	uLongf len = *dstlen;
821 
822 	if ((ret = compress2(dst, &len, src, srclen, level)) == Z_OK)
823 		*dstlen = (size_t)len;
824 
825 	return (ret);
826 }
827 
828 uid_t
829 crgetuid(cred_t *cr)
830 {
831 	return (0);
832 }
833 
834 gid_t
835 crgetgid(cred_t *cr)
836 {
837 	return (0);
838 }
839 
840 int
841 crgetngroups(cred_t *cr)
842 {
843 	return (0);
844 }
845 
846 gid_t *
847 crgetgroups(cred_t *cr)
848 {
849 	return (NULL);
850 }
851 
852 int
853 zfs_secpolicy_snapshot_perms(const char *name, cred_t *cr)
854 {
855 	return (0);
856 }
857 
858 int
859 zfs_secpolicy_rename_perms(const char *from, const char *to, cred_t *cr)
860 {
861 	return (0);
862 }
863 
864 int
865 zfs_secpolicy_destroy_perms(const char *name, cred_t *cr)
866 {
867 	return (0);
868 }
869 
870 ksiddomain_t *
871 ksid_lookupdomain(const char *dom)
872 {
873 	ksiddomain_t *kd;
874 
875 	kd = umem_zalloc(sizeof (ksiddomain_t), UMEM_NOFAIL);
876 	kd->kd_name = spa_strdup(dom);
877 	return (kd);
878 }
879 
880 void
881 ksiddomain_rele(ksiddomain_t *ksid)
882 {
883 	spa_strfree(ksid->kd_name);
884 	umem_free(ksid, sizeof (ksiddomain_t));
885 }
886