xref: /freebsd/sys/contrib/openzfs/lib/libzpool/kernel.c (revision 6580f5c38dd5b01aeeaed16b370f1a12423437f0)
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 https://opensource.org/licenses/CDDL-1.0.
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 (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
23  * Copyright (c) 2012, 2018 by Delphix. All rights reserved.
24  * Copyright (c) 2016 Actifio, Inc. All rights reserved.
25  */
26 
27 #include <assert.h>
28 #include <fcntl.h>
29 #include <libgen.h>
30 #include <poll.h>
31 #include <stdio.h>
32 #include <stdlib.h>
33 #include <string.h>
34 #include <limits.h>
35 #include <libzutil.h>
36 #include <sys/crypto/icp.h>
37 #include <sys/processor.h>
38 #include <sys/rrwlock.h>
39 #include <sys/spa.h>
40 #include <sys/stat.h>
41 #include <sys/systeminfo.h>
42 #include <sys/time.h>
43 #include <sys/utsname.h>
44 #include <sys/zfs_context.h>
45 #include <sys/zfs_onexit.h>
46 #include <sys/zfs_vfsops.h>
47 #include <sys/zstd/zstd.h>
48 #include <sys/zvol.h>
49 #include <zfs_fletcher.h>
50 #include <zlib.h>
51 
52 /*
53  * Emulation of kernel services in userland.
54  */
55 
56 uint64_t physmem;
57 uint32_t hostid;
58 struct utsname hw_utsname;
59 
60 /* If set, all blocks read will be copied to the specified directory. */
61 char *vn_dumpdir = NULL;
62 
63 /* this only exists to have its address taken */
64 struct proc p0;
65 
66 /*
67  * =========================================================================
68  * threads
69  * =========================================================================
70  *
71  * TS_STACK_MIN is dictated by the minimum allowed pthread stack size.  While
72  * TS_STACK_MAX is somewhat arbitrary, it was selected to be large enough for
73  * the expected stack depth while small enough to avoid exhausting address
74  * space with high thread counts.
75  */
76 #define	TS_STACK_MIN	MAX(PTHREAD_STACK_MIN, 32768)
77 #define	TS_STACK_MAX	(256 * 1024)
78 
79 struct zk_thread_wrapper {
80 	void (*func)(void *);
81 	void *arg;
82 };
83 
84 static void *
85 zk_thread_wrapper(void *arg)
86 {
87 	struct zk_thread_wrapper ztw;
88 	memcpy(&ztw, arg, sizeof (ztw));
89 	free(arg);
90 	ztw.func(ztw.arg);
91 	return (NULL);
92 }
93 
94 kthread_t *
95 zk_thread_create(const char *name, void (*func)(void *), void *arg,
96     size_t stksize, int state)
97 {
98 	pthread_attr_t attr;
99 	pthread_t tid;
100 	char *stkstr;
101 	struct zk_thread_wrapper *ztw;
102 	int detachstate = PTHREAD_CREATE_DETACHED;
103 
104 	VERIFY0(pthread_attr_init(&attr));
105 
106 	if (state & TS_JOINABLE)
107 		detachstate = PTHREAD_CREATE_JOINABLE;
108 
109 	VERIFY0(pthread_attr_setdetachstate(&attr, detachstate));
110 
111 	/*
112 	 * We allow the default stack size in user space to be specified by
113 	 * setting the ZFS_STACK_SIZE environment variable.  This allows us
114 	 * the convenience of observing and debugging stack overruns in
115 	 * user space.  Explicitly specified stack sizes will be honored.
116 	 * The usage of ZFS_STACK_SIZE is discussed further in the
117 	 * ENVIRONMENT VARIABLES sections of the ztest(1) man page.
118 	 */
119 	if (stksize == 0) {
120 		stkstr = getenv("ZFS_STACK_SIZE");
121 
122 		if (stkstr == NULL)
123 			stksize = TS_STACK_MAX;
124 		else
125 			stksize = MAX(atoi(stkstr), TS_STACK_MIN);
126 	}
127 
128 	VERIFY3S(stksize, >, 0);
129 	stksize = P2ROUNDUP(MAX(stksize, TS_STACK_MIN), PAGESIZE);
130 
131 	/*
132 	 * If this ever fails, it may be because the stack size is not a
133 	 * multiple of system page size.
134 	 */
135 	VERIFY0(pthread_attr_setstacksize(&attr, stksize));
136 	VERIFY0(pthread_attr_setguardsize(&attr, PAGESIZE));
137 
138 	VERIFY(ztw = malloc(sizeof (*ztw)));
139 	ztw->func = func;
140 	ztw->arg = arg;
141 	VERIFY0(pthread_create(&tid, &attr, zk_thread_wrapper, ztw));
142 	VERIFY0(pthread_attr_destroy(&attr));
143 
144 	pthread_setname_np(tid, name);
145 
146 	return ((void *)(uintptr_t)tid);
147 }
148 
149 /*
150  * =========================================================================
151  * kstats
152  * =========================================================================
153  */
154 kstat_t *
155 kstat_create(const char *module, int instance, const char *name,
156     const char *class, uchar_t type, ulong_t ndata, uchar_t ks_flag)
157 {
158 	(void) module, (void) instance, (void) name, (void) class, (void) type,
159 	    (void) ndata, (void) ks_flag;
160 	return (NULL);
161 }
162 
163 void
164 kstat_install(kstat_t *ksp)
165 {
166 	(void) ksp;
167 }
168 
169 void
170 kstat_delete(kstat_t *ksp)
171 {
172 	(void) ksp;
173 }
174 
175 void
176 kstat_set_raw_ops(kstat_t *ksp,
177     int (*headers)(char *buf, size_t size),
178     int (*data)(char *buf, size_t size, void *data),
179     void *(*addr)(kstat_t *ksp, loff_t index))
180 {
181 	(void) ksp, (void) headers, (void) data, (void) addr;
182 }
183 
184 /*
185  * =========================================================================
186  * mutexes
187  * =========================================================================
188  */
189 
190 void
191 mutex_init(kmutex_t *mp, char *name, int type, void *cookie)
192 {
193 	(void) name, (void) type, (void) cookie;
194 	VERIFY0(pthread_mutex_init(&mp->m_lock, NULL));
195 	memset(&mp->m_owner, 0, sizeof (pthread_t));
196 }
197 
198 void
199 mutex_destroy(kmutex_t *mp)
200 {
201 	VERIFY0(pthread_mutex_destroy(&mp->m_lock));
202 }
203 
204 void
205 mutex_enter(kmutex_t *mp)
206 {
207 	VERIFY0(pthread_mutex_lock(&mp->m_lock));
208 	mp->m_owner = pthread_self();
209 }
210 
211 int
212 mutex_enter_check_return(kmutex_t *mp)
213 {
214 	int error = pthread_mutex_lock(&mp->m_lock);
215 	if (error == 0)
216 		mp->m_owner = pthread_self();
217 	return (error);
218 }
219 
220 int
221 mutex_tryenter(kmutex_t *mp)
222 {
223 	int error = pthread_mutex_trylock(&mp->m_lock);
224 	if (error == 0) {
225 		mp->m_owner = pthread_self();
226 		return (1);
227 	} else {
228 		VERIFY3S(error, ==, EBUSY);
229 		return (0);
230 	}
231 }
232 
233 void
234 mutex_exit(kmutex_t *mp)
235 {
236 	memset(&mp->m_owner, 0, sizeof (pthread_t));
237 	VERIFY0(pthread_mutex_unlock(&mp->m_lock));
238 }
239 
240 /*
241  * =========================================================================
242  * rwlocks
243  * =========================================================================
244  */
245 
246 void
247 rw_init(krwlock_t *rwlp, char *name, int type, void *arg)
248 {
249 	(void) name, (void) type, (void) arg;
250 	VERIFY0(pthread_rwlock_init(&rwlp->rw_lock, NULL));
251 	rwlp->rw_readers = 0;
252 	rwlp->rw_owner = 0;
253 }
254 
255 void
256 rw_destroy(krwlock_t *rwlp)
257 {
258 	VERIFY0(pthread_rwlock_destroy(&rwlp->rw_lock));
259 }
260 
261 void
262 rw_enter(krwlock_t *rwlp, krw_t rw)
263 {
264 	if (rw == RW_READER) {
265 		VERIFY0(pthread_rwlock_rdlock(&rwlp->rw_lock));
266 		atomic_inc_uint(&rwlp->rw_readers);
267 	} else {
268 		VERIFY0(pthread_rwlock_wrlock(&rwlp->rw_lock));
269 		rwlp->rw_owner = pthread_self();
270 	}
271 }
272 
273 void
274 rw_exit(krwlock_t *rwlp)
275 {
276 	if (RW_READ_HELD(rwlp))
277 		atomic_dec_uint(&rwlp->rw_readers);
278 	else
279 		rwlp->rw_owner = 0;
280 
281 	VERIFY0(pthread_rwlock_unlock(&rwlp->rw_lock));
282 }
283 
284 int
285 rw_tryenter(krwlock_t *rwlp, krw_t rw)
286 {
287 	int error;
288 
289 	if (rw == RW_READER)
290 		error = pthread_rwlock_tryrdlock(&rwlp->rw_lock);
291 	else
292 		error = pthread_rwlock_trywrlock(&rwlp->rw_lock);
293 
294 	if (error == 0) {
295 		if (rw == RW_READER)
296 			atomic_inc_uint(&rwlp->rw_readers);
297 		else
298 			rwlp->rw_owner = pthread_self();
299 
300 		return (1);
301 	}
302 
303 	VERIFY3S(error, ==, EBUSY);
304 
305 	return (0);
306 }
307 
308 uint32_t
309 zone_get_hostid(void *zonep)
310 {
311 	/*
312 	 * We're emulating the system's hostid in userland.
313 	 */
314 	(void) zonep;
315 	return (hostid);
316 }
317 
318 int
319 rw_tryupgrade(krwlock_t *rwlp)
320 {
321 	(void) rwlp;
322 	return (0);
323 }
324 
325 /*
326  * =========================================================================
327  * condition variables
328  * =========================================================================
329  */
330 
331 void
332 cv_init(kcondvar_t *cv, char *name, int type, void *arg)
333 {
334 	(void) name, (void) type, (void) arg;
335 	VERIFY0(pthread_cond_init(cv, NULL));
336 }
337 
338 void
339 cv_destroy(kcondvar_t *cv)
340 {
341 	VERIFY0(pthread_cond_destroy(cv));
342 }
343 
344 void
345 cv_wait(kcondvar_t *cv, kmutex_t *mp)
346 {
347 	memset(&mp->m_owner, 0, sizeof (pthread_t));
348 	VERIFY0(pthread_cond_wait(cv, &mp->m_lock));
349 	mp->m_owner = pthread_self();
350 }
351 
352 int
353 cv_wait_sig(kcondvar_t *cv, kmutex_t *mp)
354 {
355 	cv_wait(cv, mp);
356 	return (1);
357 }
358 
359 int
360 cv_timedwait(kcondvar_t *cv, kmutex_t *mp, clock_t abstime)
361 {
362 	int error;
363 	struct timeval tv;
364 	struct timespec ts;
365 	clock_t delta;
366 
367 	delta = abstime - ddi_get_lbolt();
368 	if (delta <= 0)
369 		return (-1);
370 
371 	VERIFY(gettimeofday(&tv, NULL) == 0);
372 
373 	ts.tv_sec = tv.tv_sec + delta / hz;
374 	ts.tv_nsec = tv.tv_usec * NSEC_PER_USEC + (delta % hz) * (NANOSEC / hz);
375 	if (ts.tv_nsec >= NANOSEC) {
376 		ts.tv_sec++;
377 		ts.tv_nsec -= NANOSEC;
378 	}
379 
380 	memset(&mp->m_owner, 0, sizeof (pthread_t));
381 	error = pthread_cond_timedwait(cv, &mp->m_lock, &ts);
382 	mp->m_owner = pthread_self();
383 
384 	if (error == ETIMEDOUT)
385 		return (-1);
386 
387 	VERIFY0(error);
388 
389 	return (1);
390 }
391 
392 int
393 cv_timedwait_hires(kcondvar_t *cv, kmutex_t *mp, hrtime_t tim, hrtime_t res,
394     int flag)
395 {
396 	(void) res;
397 	int error;
398 	struct timeval tv;
399 	struct timespec ts;
400 	hrtime_t delta;
401 
402 	ASSERT(flag == 0 || flag == CALLOUT_FLAG_ABSOLUTE);
403 
404 	delta = tim;
405 	if (flag & CALLOUT_FLAG_ABSOLUTE)
406 		delta -= gethrtime();
407 
408 	if (delta <= 0)
409 		return (-1);
410 
411 	VERIFY0(gettimeofday(&tv, NULL));
412 
413 	ts.tv_sec = tv.tv_sec + delta / NANOSEC;
414 	ts.tv_nsec = tv.tv_usec * NSEC_PER_USEC + (delta % NANOSEC);
415 	if (ts.tv_nsec >= NANOSEC) {
416 		ts.tv_sec++;
417 		ts.tv_nsec -= NANOSEC;
418 	}
419 
420 	memset(&mp->m_owner, 0, sizeof (pthread_t));
421 	error = pthread_cond_timedwait(cv, &mp->m_lock, &ts);
422 	mp->m_owner = pthread_self();
423 
424 	if (error == ETIMEDOUT)
425 		return (-1);
426 
427 	VERIFY0(error);
428 
429 	return (1);
430 }
431 
432 void
433 cv_signal(kcondvar_t *cv)
434 {
435 	VERIFY0(pthread_cond_signal(cv));
436 }
437 
438 void
439 cv_broadcast(kcondvar_t *cv)
440 {
441 	VERIFY0(pthread_cond_broadcast(cv));
442 }
443 
444 /*
445  * =========================================================================
446  * procfs list
447  * =========================================================================
448  */
449 
450 void
451 seq_printf(struct seq_file *m, const char *fmt, ...)
452 {
453 	(void) m, (void) fmt;
454 }
455 
456 void
457 procfs_list_install(const char *module,
458     const char *submodule,
459     const char *name,
460     mode_t mode,
461     procfs_list_t *procfs_list,
462     int (*show)(struct seq_file *f, void *p),
463     int (*show_header)(struct seq_file *f),
464     int (*clear)(procfs_list_t *procfs_list),
465     size_t procfs_list_node_off)
466 {
467 	(void) module, (void) submodule, (void) name, (void) mode, (void) show,
468 	    (void) show_header, (void) clear;
469 	mutex_init(&procfs_list->pl_lock, NULL, MUTEX_DEFAULT, NULL);
470 	list_create(&procfs_list->pl_list,
471 	    procfs_list_node_off + sizeof (procfs_list_node_t),
472 	    procfs_list_node_off + offsetof(procfs_list_node_t, pln_link));
473 	procfs_list->pl_next_id = 1;
474 	procfs_list->pl_node_offset = procfs_list_node_off;
475 }
476 
477 void
478 procfs_list_uninstall(procfs_list_t *procfs_list)
479 {
480 	(void) procfs_list;
481 }
482 
483 void
484 procfs_list_destroy(procfs_list_t *procfs_list)
485 {
486 	ASSERT(list_is_empty(&procfs_list->pl_list));
487 	list_destroy(&procfs_list->pl_list);
488 	mutex_destroy(&procfs_list->pl_lock);
489 }
490 
491 #define	NODE_ID(procfs_list, obj) \
492 		(((procfs_list_node_t *)(((char *)obj) + \
493 		(procfs_list)->pl_node_offset))->pln_id)
494 
495 void
496 procfs_list_add(procfs_list_t *procfs_list, void *p)
497 {
498 	ASSERT(MUTEX_HELD(&procfs_list->pl_lock));
499 	NODE_ID(procfs_list, p) = procfs_list->pl_next_id++;
500 	list_insert_tail(&procfs_list->pl_list, p);
501 }
502 
503 /*
504  * =========================================================================
505  * vnode operations
506  * =========================================================================
507  */
508 
509 /*
510  * =========================================================================
511  * Figure out which debugging statements to print
512  * =========================================================================
513  */
514 
515 static char *dprintf_string;
516 static int dprintf_print_all;
517 
518 int
519 dprintf_find_string(const char *string)
520 {
521 	char *tmp_str = dprintf_string;
522 	int len = strlen(string);
523 
524 	/*
525 	 * Find out if this is a string we want to print.
526 	 * String format: file1.c,function_name1,file2.c,file3.c
527 	 */
528 
529 	while (tmp_str != NULL) {
530 		if (strncmp(tmp_str, string, len) == 0 &&
531 		    (tmp_str[len] == ',' || tmp_str[len] == '\0'))
532 			return (1);
533 		tmp_str = strchr(tmp_str, ',');
534 		if (tmp_str != NULL)
535 			tmp_str++; /* Get rid of , */
536 	}
537 	return (0);
538 }
539 
540 void
541 dprintf_setup(int *argc, char **argv)
542 {
543 	int i, j;
544 
545 	/*
546 	 * Debugging can be specified two ways: by setting the
547 	 * environment variable ZFS_DEBUG, or by including a
548 	 * "debug=..."  argument on the command line.  The command
549 	 * line setting overrides the environment variable.
550 	 */
551 
552 	for (i = 1; i < *argc; i++) {
553 		int len = strlen("debug=");
554 		/* First look for a command line argument */
555 		if (strncmp("debug=", argv[i], len) == 0) {
556 			dprintf_string = argv[i] + len;
557 			/* Remove from args */
558 			for (j = i; j < *argc; j++)
559 				argv[j] = argv[j+1];
560 			argv[j] = NULL;
561 			(*argc)--;
562 		}
563 	}
564 
565 	if (dprintf_string == NULL) {
566 		/* Look for ZFS_DEBUG environment variable */
567 		dprintf_string = getenv("ZFS_DEBUG");
568 	}
569 
570 	/*
571 	 * Are we just turning on all debugging?
572 	 */
573 	if (dprintf_find_string("on"))
574 		dprintf_print_all = 1;
575 
576 	if (dprintf_string != NULL)
577 		zfs_flags |= ZFS_DEBUG_DPRINTF;
578 }
579 
580 /*
581  * =========================================================================
582  * debug printfs
583  * =========================================================================
584  */
585 void
586 __dprintf(boolean_t dprint, const char *file, const char *func,
587     int line, const char *fmt, ...)
588 {
589 	/* Get rid of annoying "../common/" prefix to filename. */
590 	const char *newfile = zfs_basename(file);
591 
592 	va_list adx;
593 	if (dprint) {
594 		/* dprintf messages are printed immediately */
595 
596 		if (!dprintf_print_all &&
597 		    !dprintf_find_string(newfile) &&
598 		    !dprintf_find_string(func))
599 			return;
600 
601 		/* Print out just the function name if requested */
602 		flockfile(stdout);
603 		if (dprintf_find_string("pid"))
604 			(void) printf("%d ", getpid());
605 		if (dprintf_find_string("tid"))
606 			(void) printf("%ju ",
607 			    (uintmax_t)(uintptr_t)pthread_self());
608 		if (dprintf_find_string("cpu"))
609 			(void) printf("%u ", getcpuid());
610 		if (dprintf_find_string("time"))
611 			(void) printf("%llu ", gethrtime());
612 		if (dprintf_find_string("long"))
613 			(void) printf("%s, line %d: ", newfile, line);
614 		(void) printf("dprintf: %s: ", func);
615 		va_start(adx, fmt);
616 		(void) vprintf(fmt, adx);
617 		va_end(adx);
618 		funlockfile(stdout);
619 	} else {
620 		/* zfs_dbgmsg is logged for dumping later */
621 		size_t size;
622 		char *buf;
623 		int i;
624 
625 		size = 1024;
626 		buf = umem_alloc(size, UMEM_NOFAIL);
627 		i = snprintf(buf, size, "%s:%d:%s(): ", newfile, line, func);
628 
629 		if (i < size) {
630 			va_start(adx, fmt);
631 			(void) vsnprintf(buf + i, size - i, fmt, adx);
632 			va_end(adx);
633 		}
634 
635 		__zfs_dbgmsg(buf);
636 
637 		umem_free(buf, size);
638 	}
639 }
640 
641 /*
642  * =========================================================================
643  * cmn_err() and panic()
644  * =========================================================================
645  */
646 static char ce_prefix[CE_IGNORE][10] = { "", "NOTICE: ", "WARNING: ", "" };
647 static char ce_suffix[CE_IGNORE][2] = { "", "\n", "\n", "" };
648 
649 __attribute__((noreturn)) void
650 vpanic(const char *fmt, va_list adx)
651 {
652 	(void) fprintf(stderr, "error: ");
653 	(void) vfprintf(stderr, fmt, adx);
654 	(void) fprintf(stderr, "\n");
655 
656 	abort();	/* think of it as a "user-level crash dump" */
657 }
658 
659 __attribute__((noreturn)) void
660 panic(const char *fmt, ...)
661 {
662 	va_list adx;
663 
664 	va_start(adx, fmt);
665 	vpanic(fmt, adx);
666 	va_end(adx);
667 }
668 
669 void
670 vcmn_err(int ce, const char *fmt, va_list adx)
671 {
672 	if (ce == CE_PANIC)
673 		vpanic(fmt, adx);
674 	if (ce != CE_NOTE) {	/* suppress noise in userland stress testing */
675 		(void) fprintf(stderr, "%s", ce_prefix[ce]);
676 		(void) vfprintf(stderr, fmt, adx);
677 		(void) fprintf(stderr, "%s", ce_suffix[ce]);
678 	}
679 }
680 
681 void
682 cmn_err(int ce, const char *fmt, ...)
683 {
684 	va_list adx;
685 
686 	va_start(adx, fmt);
687 	vcmn_err(ce, fmt, adx);
688 	va_end(adx);
689 }
690 
691 /*
692  * =========================================================================
693  * misc routines
694  * =========================================================================
695  */
696 
697 void
698 delay(clock_t ticks)
699 {
700 	(void) poll(0, 0, ticks * (1000 / hz));
701 }
702 
703 /*
704  * Find highest one bit set.
705  * Returns bit number + 1 of highest bit that is set, otherwise returns 0.
706  * The __builtin_clzll() function is supported by both GCC and Clang.
707  */
708 int
709 highbit64(uint64_t i)
710 {
711 	if (i == 0)
712 	return (0);
713 
714 	return (NBBY * sizeof (uint64_t) - __builtin_clzll(i));
715 }
716 
717 /*
718  * Find lowest one bit set.
719  * Returns bit number + 1 of lowest bit that is set, otherwise returns 0.
720  * The __builtin_ffsll() function is supported by both GCC and Clang.
721  */
722 int
723 lowbit64(uint64_t i)
724 {
725 	if (i == 0)
726 		return (0);
727 
728 	return (__builtin_ffsll(i));
729 }
730 
731 const char *random_path = "/dev/random";
732 const char *urandom_path = "/dev/urandom";
733 static int random_fd = -1, urandom_fd = -1;
734 
735 void
736 random_init(void)
737 {
738 	VERIFY((random_fd = open(random_path, O_RDONLY | O_CLOEXEC)) != -1);
739 	VERIFY((urandom_fd = open(urandom_path, O_RDONLY | O_CLOEXEC)) != -1);
740 }
741 
742 void
743 random_fini(void)
744 {
745 	close(random_fd);
746 	close(urandom_fd);
747 
748 	random_fd = -1;
749 	urandom_fd = -1;
750 }
751 
752 static int
753 random_get_bytes_common(uint8_t *ptr, size_t len, int fd)
754 {
755 	size_t resid = len;
756 	ssize_t bytes;
757 
758 	ASSERT(fd != -1);
759 
760 	while (resid != 0) {
761 		bytes = read(fd, ptr, resid);
762 		ASSERT3S(bytes, >=, 0);
763 		ptr += bytes;
764 		resid -= bytes;
765 	}
766 
767 	return (0);
768 }
769 
770 int
771 random_get_bytes(uint8_t *ptr, size_t len)
772 {
773 	return (random_get_bytes_common(ptr, len, random_fd));
774 }
775 
776 int
777 random_get_pseudo_bytes(uint8_t *ptr, size_t len)
778 {
779 	return (random_get_bytes_common(ptr, len, urandom_fd));
780 }
781 
782 int
783 ddi_strtoull(const char *str, char **nptr, int base, u_longlong_t *result)
784 {
785 	errno = 0;
786 	*result = strtoull(str, nptr, base);
787 	if (*result == 0)
788 		return (errno);
789 	return (0);
790 }
791 
792 utsname_t *
793 utsname(void)
794 {
795 	return (&hw_utsname);
796 }
797 
798 /*
799  * =========================================================================
800  * kernel emulation setup & teardown
801  * =========================================================================
802  */
803 static int
804 umem_out_of_memory(void)
805 {
806 	char errmsg[] = "out of memory -- generating core dump\n";
807 
808 	(void) fprintf(stderr, "%s", errmsg);
809 	abort();
810 	return (0);
811 }
812 
813 void
814 kernel_init(int mode)
815 {
816 	extern uint_t rrw_tsd_key;
817 
818 	umem_nofail_callback(umem_out_of_memory);
819 
820 	physmem = sysconf(_SC_PHYS_PAGES);
821 
822 	dprintf("physmem = %llu pages (%.2f GB)\n", (u_longlong_t)physmem,
823 	    (double)physmem * sysconf(_SC_PAGE_SIZE) / (1ULL << 30));
824 
825 	hostid = (mode & SPA_MODE_WRITE) ? get_system_hostid() : 0;
826 
827 	random_init();
828 
829 	VERIFY0(uname(&hw_utsname));
830 
831 	system_taskq_init();
832 	icp_init();
833 
834 	zstd_init();
835 
836 	spa_init((spa_mode_t)mode);
837 
838 	fletcher_4_init();
839 
840 	tsd_create(&rrw_tsd_key, rrw_tsd_destroy);
841 }
842 
843 void
844 kernel_fini(void)
845 {
846 	fletcher_4_fini();
847 	spa_fini();
848 
849 	zstd_fini();
850 
851 	icp_fini();
852 	system_taskq_fini();
853 
854 	random_fini();
855 }
856 
857 uid_t
858 crgetuid(cred_t *cr)
859 {
860 	(void) cr;
861 	return (0);
862 }
863 
864 uid_t
865 crgetruid(cred_t *cr)
866 {
867 	(void) cr;
868 	return (0);
869 }
870 
871 gid_t
872 crgetgid(cred_t *cr)
873 {
874 	(void) cr;
875 	return (0);
876 }
877 
878 int
879 crgetngroups(cred_t *cr)
880 {
881 	(void) cr;
882 	return (0);
883 }
884 
885 gid_t *
886 crgetgroups(cred_t *cr)
887 {
888 	(void) cr;
889 	return (NULL);
890 }
891 
892 int
893 zfs_secpolicy_snapshot_perms(const char *name, cred_t *cr)
894 {
895 	(void) name, (void) cr;
896 	return (0);
897 }
898 
899 int
900 zfs_secpolicy_rename_perms(const char *from, const char *to, cred_t *cr)
901 {
902 	(void) from, (void) to, (void) cr;
903 	return (0);
904 }
905 
906 int
907 zfs_secpolicy_destroy_perms(const char *name, cred_t *cr)
908 {
909 	(void) name, (void) cr;
910 	return (0);
911 }
912 
913 int
914 secpolicy_zfs(const cred_t *cr)
915 {
916 	(void) cr;
917 	return (0);
918 }
919 
920 int
921 secpolicy_zfs_proc(const cred_t *cr, proc_t *proc)
922 {
923 	(void) cr, (void) proc;
924 	return (0);
925 }
926 
927 ksiddomain_t *
928 ksid_lookupdomain(const char *dom)
929 {
930 	ksiddomain_t *kd;
931 
932 	kd = umem_zalloc(sizeof (ksiddomain_t), UMEM_NOFAIL);
933 	kd->kd_name = spa_strdup(dom);
934 	return (kd);
935 }
936 
937 void
938 ksiddomain_rele(ksiddomain_t *ksid)
939 {
940 	spa_strfree(ksid->kd_name);
941 	umem_free(ksid, sizeof (ksiddomain_t));
942 }
943 
944 char *
945 kmem_vasprintf(const char *fmt, va_list adx)
946 {
947 	char *buf = NULL;
948 	va_list adx_copy;
949 
950 	va_copy(adx_copy, adx);
951 	VERIFY(vasprintf(&buf, fmt, adx_copy) != -1);
952 	va_end(adx_copy);
953 
954 	return (buf);
955 }
956 
957 char *
958 kmem_asprintf(const char *fmt, ...)
959 {
960 	char *buf = NULL;
961 	va_list adx;
962 
963 	va_start(adx, fmt);
964 	VERIFY(vasprintf(&buf, fmt, adx) != -1);
965 	va_end(adx);
966 
967 	return (buf);
968 }
969 
970 /*
971  * kmem_scnprintf() will return the number of characters that it would have
972  * printed whenever it is limited by value of the size variable, rather than
973  * the number of characters that it did print. This can cause misbehavior on
974  * subsequent uses of the return value, so we define a safe version that will
975  * return the number of characters actually printed, minus the NULL format
976  * character.  Subsequent use of this by the safe string functions is safe
977  * whether it is snprintf(), strlcat() or strlcpy().
978  */
979 int
980 kmem_scnprintf(char *restrict str, size_t size, const char *restrict fmt, ...)
981 {
982 	int n;
983 	va_list ap;
984 
985 	/* Make the 0 case a no-op so that we do not return -1 */
986 	if (size == 0)
987 		return (0);
988 
989 	va_start(ap, fmt);
990 	n = vsnprintf(str, size, fmt, ap);
991 	va_end(ap);
992 
993 	if (n >= size)
994 		n = size - 1;
995 
996 	return (n);
997 }
998 
999 zfs_file_t *
1000 zfs_onexit_fd_hold(int fd, minor_t *minorp)
1001 {
1002 	(void) fd;
1003 	*minorp = 0;
1004 	return (NULL);
1005 }
1006 
1007 void
1008 zfs_onexit_fd_rele(zfs_file_t *fp)
1009 {
1010 	(void) fp;
1011 }
1012 
1013 int
1014 zfs_onexit_add_cb(minor_t minor, void (*func)(void *), void *data,
1015     uintptr_t *action_handle)
1016 {
1017 	(void) minor, (void) func, (void) data, (void) action_handle;
1018 	return (0);
1019 }
1020 
1021 fstrans_cookie_t
1022 spl_fstrans_mark(void)
1023 {
1024 	return ((fstrans_cookie_t)0);
1025 }
1026 
1027 void
1028 spl_fstrans_unmark(fstrans_cookie_t cookie)
1029 {
1030 	(void) cookie;
1031 }
1032 
1033 int
1034 __spl_pf_fstrans_check(void)
1035 {
1036 	return (0);
1037 }
1038 
1039 int
1040 kmem_cache_reap_active(void)
1041 {
1042 	return (0);
1043 }
1044 
1045 void
1046 zvol_create_minor(const char *name)
1047 {
1048 	(void) name;
1049 }
1050 
1051 void
1052 zvol_create_minors_recursive(const char *name)
1053 {
1054 	(void) name;
1055 }
1056 
1057 void
1058 zvol_remove_minors(spa_t *spa, const char *name, boolean_t async)
1059 {
1060 	(void) spa, (void) name, (void) async;
1061 }
1062 
1063 void
1064 zvol_rename_minors(spa_t *spa, const char *oldname, const char *newname,
1065     boolean_t async)
1066 {
1067 	(void) spa, (void) oldname, (void) newname, (void) async;
1068 }
1069 
1070 /*
1071  * Open file
1072  *
1073  * path - fully qualified path to file
1074  * flags - file attributes O_READ / O_WRITE / O_EXCL
1075  * fpp - pointer to return file pointer
1076  *
1077  * Returns 0 on success underlying error on failure.
1078  */
1079 int
1080 zfs_file_open(const char *path, int flags, int mode, zfs_file_t **fpp)
1081 {
1082 	int fd = -1;
1083 	int dump_fd = -1;
1084 	int err;
1085 	int old_umask = 0;
1086 	zfs_file_t *fp;
1087 	struct stat64 st;
1088 
1089 	if (!(flags & O_CREAT) && stat64(path, &st) == -1)
1090 		return (errno);
1091 
1092 	if (!(flags & O_CREAT) && S_ISBLK(st.st_mode))
1093 		flags |= O_DIRECT;
1094 
1095 	if (flags & O_CREAT)
1096 		old_umask = umask(0);
1097 
1098 	fd = open64(path, flags, mode);
1099 	if (fd == -1)
1100 		return (errno);
1101 
1102 	if (flags & O_CREAT)
1103 		(void) umask(old_umask);
1104 
1105 	if (vn_dumpdir != NULL) {
1106 		char *dumppath = umem_zalloc(MAXPATHLEN, UMEM_NOFAIL);
1107 		const char *inpath = zfs_basename(path);
1108 
1109 		(void) snprintf(dumppath, MAXPATHLEN,
1110 		    "%s/%s", vn_dumpdir, inpath);
1111 		dump_fd = open64(dumppath, O_CREAT | O_WRONLY, 0666);
1112 		umem_free(dumppath, MAXPATHLEN);
1113 		if (dump_fd == -1) {
1114 			err = errno;
1115 			close(fd);
1116 			return (err);
1117 		}
1118 	} else {
1119 		dump_fd = -1;
1120 	}
1121 
1122 	(void) fcntl(fd, F_SETFD, FD_CLOEXEC);
1123 
1124 	fp = umem_zalloc(sizeof (zfs_file_t), UMEM_NOFAIL);
1125 	fp->f_fd = fd;
1126 	fp->f_dump_fd = dump_fd;
1127 	*fpp = fp;
1128 
1129 	return (0);
1130 }
1131 
1132 void
1133 zfs_file_close(zfs_file_t *fp)
1134 {
1135 	close(fp->f_fd);
1136 	if (fp->f_dump_fd != -1)
1137 		close(fp->f_dump_fd);
1138 
1139 	umem_free(fp, sizeof (zfs_file_t));
1140 }
1141 
1142 /*
1143  * Stateful write - use os internal file pointer to determine where to
1144  * write and update on successful completion.
1145  *
1146  * fp -  pointer to file (pipe, socket, etc) to write to
1147  * buf - buffer to write
1148  * count - # of bytes to write
1149  * resid -  pointer to count of unwritten bytes  (if short write)
1150  *
1151  * Returns 0 on success errno on failure.
1152  */
1153 int
1154 zfs_file_write(zfs_file_t *fp, const void *buf, size_t count, ssize_t *resid)
1155 {
1156 	ssize_t rc;
1157 
1158 	rc = write(fp->f_fd, buf, count);
1159 	if (rc < 0)
1160 		return (errno);
1161 
1162 	if (resid) {
1163 		*resid = count - rc;
1164 	} else if (rc != count) {
1165 		return (EIO);
1166 	}
1167 
1168 	return (0);
1169 }
1170 
1171 /*
1172  * Stateless write - os internal file pointer is not updated.
1173  *
1174  * fp -  pointer to file (pipe, socket, etc) to write to
1175  * buf - buffer to write
1176  * count - # of bytes to write
1177  * off - file offset to write to (only valid for seekable types)
1178  * resid -  pointer to count of unwritten bytes
1179  *
1180  * Returns 0 on success errno on failure.
1181  */
1182 int
1183 zfs_file_pwrite(zfs_file_t *fp, const void *buf,
1184     size_t count, loff_t pos, ssize_t *resid)
1185 {
1186 	ssize_t rc, split, done;
1187 	int sectors;
1188 
1189 	/*
1190 	 * To simulate partial disk writes, we split writes into two
1191 	 * system calls so that the process can be killed in between.
1192 	 * This is used by ztest to simulate realistic failure modes.
1193 	 */
1194 	sectors = count >> SPA_MINBLOCKSHIFT;
1195 	split = (sectors > 0 ? rand() % sectors : 0) << SPA_MINBLOCKSHIFT;
1196 	rc = pwrite64(fp->f_fd, buf, split, pos);
1197 	if (rc != -1) {
1198 		done = rc;
1199 		rc = pwrite64(fp->f_fd, (char *)buf + split,
1200 		    count - split, pos + split);
1201 	}
1202 #ifdef __linux__
1203 	if (rc == -1 && errno == EINVAL) {
1204 		/*
1205 		 * Under Linux, this most likely means an alignment issue
1206 		 * (memory or disk) due to O_DIRECT, so we abort() in order
1207 		 * to catch the offender.
1208 		 */
1209 		abort();
1210 	}
1211 #endif
1212 
1213 	if (rc < 0)
1214 		return (errno);
1215 
1216 	done += rc;
1217 
1218 	if (resid) {
1219 		*resid = count - done;
1220 	} else if (done != count) {
1221 		return (EIO);
1222 	}
1223 
1224 	return (0);
1225 }
1226 
1227 /*
1228  * Stateful read - use os internal file pointer to determine where to
1229  * read and update on successful completion.
1230  *
1231  * fp -  pointer to file (pipe, socket, etc) to read from
1232  * buf - buffer to write
1233  * count - # of bytes to read
1234  * resid -  pointer to count of unread bytes (if short read)
1235  *
1236  * Returns 0 on success errno on failure.
1237  */
1238 int
1239 zfs_file_read(zfs_file_t *fp, void *buf, size_t count, ssize_t *resid)
1240 {
1241 	int rc;
1242 
1243 	rc = read(fp->f_fd, buf, count);
1244 	if (rc < 0)
1245 		return (errno);
1246 
1247 	if (resid) {
1248 		*resid = count - rc;
1249 	} else if (rc != count) {
1250 		return (EIO);
1251 	}
1252 
1253 	return (0);
1254 }
1255 
1256 /*
1257  * Stateless read - os internal file pointer is not updated.
1258  *
1259  * fp -  pointer to file (pipe, socket, etc) to read from
1260  * buf - buffer to write
1261  * count - # of bytes to write
1262  * off - file offset to read from (only valid for seekable types)
1263  * resid -  pointer to count of unwritten bytes (if short write)
1264  *
1265  * Returns 0 on success errno on failure.
1266  */
1267 int
1268 zfs_file_pread(zfs_file_t *fp, void *buf, size_t count, loff_t off,
1269     ssize_t *resid)
1270 {
1271 	ssize_t rc;
1272 
1273 	rc = pread64(fp->f_fd, buf, count, off);
1274 	if (rc < 0) {
1275 #ifdef __linux__
1276 		/*
1277 		 * Under Linux, this most likely means an alignment issue
1278 		 * (memory or disk) due to O_DIRECT, so we abort() in order to
1279 		 * catch the offender.
1280 		 */
1281 		if (errno == EINVAL)
1282 			abort();
1283 #endif
1284 		return (errno);
1285 	}
1286 
1287 	if (fp->f_dump_fd != -1) {
1288 		int status;
1289 
1290 		status = pwrite64(fp->f_dump_fd, buf, rc, off);
1291 		ASSERT(status != -1);
1292 	}
1293 
1294 	if (resid) {
1295 		*resid = count - rc;
1296 	} else if (rc != count) {
1297 		return (EIO);
1298 	}
1299 
1300 	return (0);
1301 }
1302 
1303 /*
1304  * lseek - set / get file pointer
1305  *
1306  * fp -  pointer to file (pipe, socket, etc) to read from
1307  * offp - value to seek to, returns current value plus passed offset
1308  * whence - see man pages for standard lseek whence values
1309  *
1310  * Returns 0 on success errno on failure (ESPIPE for non seekable types)
1311  */
1312 int
1313 zfs_file_seek(zfs_file_t *fp, loff_t *offp, int whence)
1314 {
1315 	loff_t rc;
1316 
1317 	rc = lseek(fp->f_fd, *offp, whence);
1318 	if (rc < 0)
1319 		return (errno);
1320 
1321 	*offp = rc;
1322 
1323 	return (0);
1324 }
1325 
1326 /*
1327  * Get file attributes
1328  *
1329  * filp - file pointer
1330  * zfattr - pointer to file attr structure
1331  *
1332  * Currently only used for fetching size and file mode
1333  *
1334  * Returns 0 on success or error code of underlying getattr call on failure.
1335  */
1336 int
1337 zfs_file_getattr(zfs_file_t *fp, zfs_file_attr_t *zfattr)
1338 {
1339 	struct stat64 st;
1340 
1341 	if (fstat64_blk(fp->f_fd, &st) == -1)
1342 		return (errno);
1343 
1344 	zfattr->zfa_size = st.st_size;
1345 	zfattr->zfa_mode = st.st_mode;
1346 
1347 	return (0);
1348 }
1349 
1350 /*
1351  * Sync file to disk
1352  *
1353  * filp - file pointer
1354  * flags - O_SYNC and or O_DSYNC
1355  *
1356  * Returns 0 on success or error code of underlying sync call on failure.
1357  */
1358 int
1359 zfs_file_fsync(zfs_file_t *fp, int flags)
1360 {
1361 	(void) flags;
1362 
1363 	if (fsync(fp->f_fd) < 0)
1364 		return (errno);
1365 
1366 	return (0);
1367 }
1368 
1369 /*
1370  * fallocate - allocate or free space on disk
1371  *
1372  * fp - file pointer
1373  * mode (non-standard options for hole punching etc)
1374  * offset - offset to start allocating or freeing from
1375  * len - length to free / allocate
1376  *
1377  * OPTIONAL
1378  */
1379 int
1380 zfs_file_fallocate(zfs_file_t *fp, int mode, loff_t offset, loff_t len)
1381 {
1382 #ifdef __linux__
1383 	return (fallocate(fp->f_fd, mode, offset, len));
1384 #else
1385 	(void) fp, (void) mode, (void) offset, (void) len;
1386 	return (EOPNOTSUPP);
1387 #endif
1388 }
1389 
1390 /*
1391  * Request current file pointer offset
1392  *
1393  * fp - pointer to file
1394  *
1395  * Returns current file offset.
1396  */
1397 loff_t
1398 zfs_file_off(zfs_file_t *fp)
1399 {
1400 	return (lseek(fp->f_fd, SEEK_CUR, 0));
1401 }
1402 
1403 /*
1404  * unlink file
1405  *
1406  * path - fully qualified file path
1407  *
1408  * Returns 0 on success.
1409  *
1410  * OPTIONAL
1411  */
1412 int
1413 zfs_file_unlink(const char *path)
1414 {
1415 	return (remove(path));
1416 }
1417 
1418 /*
1419  * Get reference to file pointer
1420  *
1421  * fd - input file descriptor
1422  *
1423  * Returns pointer to file struct or NULL.
1424  * Unsupported in user space.
1425  */
1426 zfs_file_t *
1427 zfs_file_get(int fd)
1428 {
1429 	(void) fd;
1430 	abort();
1431 	return (NULL);
1432 }
1433 /*
1434  * Drop reference to file pointer
1435  *
1436  * fp - pointer to file struct
1437  *
1438  * Unsupported in user space.
1439  */
1440 void
1441 zfs_file_put(zfs_file_t *fp)
1442 {
1443 	abort();
1444 	(void) fp;
1445 }
1446 
1447 void
1448 zfsvfs_update_fromname(const char *oldname, const char *newname)
1449 {
1450 	(void) oldname, (void) newname;
1451 }
1452 
1453 void
1454 spa_import_os(spa_t *spa)
1455 {
1456 	(void) spa;
1457 }
1458 
1459 void
1460 spa_export_os(spa_t *spa)
1461 {
1462 	(void) spa;
1463 }
1464 
1465 void
1466 spa_activate_os(spa_t *spa)
1467 {
1468 	(void) spa;
1469 }
1470 
1471 void
1472 spa_deactivate_os(spa_t *spa)
1473 {
1474 	(void) spa;
1475 }
1476