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kernel.c

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#include <assert.h>
#include <fcntl.h>
#include <poll.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <zlib.h>
#include <sys/spa.h>
#include <sys/stat.h>
#include <sys/processor.h>
#include <sys/zfs_context.h>
#include <sys/zmod.h>
#include <sys/utsname.h>
#include <sys/systeminfo.h>

/*
 * Emulation of kernel services in userland.
 */

uint64_t physmem;
vnode_t *rootdir = (vnode_t *)0xabcd1234;
char hw_serial[HW_HOSTID_LEN];

struct utsname utsname = {
      "userland", "libzpool", "1", "1", "na"
};

/*
 * =========================================================================
 * threads
 * =========================================================================
 */
/*ARGSUSED*/
kthread_t *
zk_thread_create(void (*func)(), void *arg)
{
      thread_t tid;

      VERIFY(thr_create(0, 0, (void *(*)(void *))func, arg, THR_DETACHED,
          &tid) == 0);

      return ((void *)(uintptr_t)tid);
}

/*
 * =========================================================================
 * kstats
 * =========================================================================
 */
/*ARGSUSED*/
kstat_t *
kstat_create(char *module, int instance, char *name, char *class,
    uchar_t type, ulong_t ndata, uchar_t ks_flag)
{
      return (NULL);
}

/*ARGSUSED*/
void
kstat_install(kstat_t *ksp)
{}

/*ARGSUSED*/
void
kstat_delete(kstat_t *ksp)
{}

/*
 * =========================================================================
 * mutexes
 * =========================================================================
 */
void
zmutex_init(kmutex_t *mp)
{
      mp->m_owner = NULL;
      mp->initialized = B_TRUE;
      (void) _mutex_init(&mp->m_lock, USYNC_THREAD, NULL);
}

void
zmutex_destroy(kmutex_t *mp)
{
      ASSERT(mp->initialized == B_TRUE);
      ASSERT(mp->m_owner == NULL);
      (void) _mutex_destroy(&(mp)->m_lock);
      mp->m_owner = (void *)-1UL;
      mp->initialized = B_FALSE;
}

void
mutex_enter(kmutex_t *mp)
{
      ASSERT(mp->initialized == B_TRUE);
      ASSERT(mp->m_owner != (void *)-1UL);
      ASSERT(mp->m_owner != curthread);
      VERIFY(mutex_lock(&mp->m_lock) == 0);
      ASSERT(mp->m_owner == NULL);
      mp->m_owner = curthread;
}

int
mutex_tryenter(kmutex_t *mp)
{
      ASSERT(mp->initialized == B_TRUE);
      ASSERT(mp->m_owner != (void *)-1UL);
      if (0 == mutex_trylock(&mp->m_lock)) {
            ASSERT(mp->m_owner == NULL);
            mp->m_owner = curthread;
            return (1);
      } else {
            return (0);
      }
}

void
mutex_exit(kmutex_t *mp)
{
      ASSERT(mp->initialized == B_TRUE);
      ASSERT(mutex_owner(mp) == curthread);
      mp->m_owner = NULL;
      VERIFY(mutex_unlock(&mp->m_lock) == 0);
}

void *
mutex_owner(kmutex_t *mp)
{
      ASSERT(mp->initialized == B_TRUE);
      return (mp->m_owner);
}

/*
 * =========================================================================
 * rwlocks
 * =========================================================================
 */
/*ARGSUSED*/
void
rw_init(krwlock_t *rwlp, char *name, int type, void *arg)
{
      rwlock_init(&rwlp->rw_lock, USYNC_THREAD, NULL);
      zmutex_init(&rwlp->mutex);
      rwlp->rw_owner = NULL;
      rwlp->initialized = B_TRUE;
      rwlp->thr_count = 0;
}

void
rw_destroy(krwlock_t *rwlp)
{
      rwlock_destroy(&rwlp->rw_lock);
      zmutex_destroy(&rwlp->mutex);
      rwlp->rw_owner = (void *)-1UL;
      rwlp->initialized = B_FALSE;
      rwlp->thr_count = -2;
}

void
rw_enter(krwlock_t *rwlp, krw_t rw)
{
      //ASSERT(!RW_LOCK_HELD(rwlp));
      ASSERT(rwlp->initialized == B_TRUE);
      ASSERT(rwlp->rw_owner != (void *)-1UL);
      ASSERT(rwlp->rw_owner != curthread);

      if (rw == RW_READER) {
            VERIFY(rw_rdlock(&rwlp->rw_lock) == 0);

            mutex_enter(&rwlp->mutex);
            ASSERT(rwlp->thr_count >= 0);
            rwlp->thr_count++;
            mutex_exit(&rwlp->mutex);
            ASSERT(rwlp->rw_owner == NULL);
      } else {
            VERIFY(rw_wrlock(&rwlp->rw_lock) == 0);

            ASSERT(rwlp->rw_owner == NULL);
            ASSERT(rwlp->thr_count == 0);
            rwlp->thr_count = -1;
            rwlp->rw_owner = curthread;
      }
}

void
rw_exit(krwlock_t *rwlp)
{
      ASSERT(rwlp->initialized == B_TRUE);
      ASSERT(rwlp->rw_owner != (void *)-1UL);

      if(rwlp->rw_owner == curthread) {
            /* Write locked */
            ASSERT(rwlp->thr_count == -1);
            rwlp->thr_count = 0;
            rwlp->rw_owner = NULL;
      } else {
            /* Read locked */
            ASSERT(rwlp->rw_owner == NULL);
            mutex_enter(&rwlp->mutex);
            ASSERT(rwlp->thr_count >= 1);
            rwlp->thr_count--;
            mutex_exit(&rwlp->mutex);
      }
      VERIFY(rw_unlock(&rwlp->rw_lock) == 0);
}

int
rw_tryenter(krwlock_t *rwlp, krw_t rw)
{
      int rv;

      ASSERT(rwlp->initialized == B_TRUE);
      ASSERT(rwlp->rw_owner != (void *)-1UL);
      ASSERT(rwlp->rw_owner != curthread);

      if (rw == RW_READER)
            rv = rw_tryrdlock(&rwlp->rw_lock);
      else
            rv = rw_trywrlock(&rwlp->rw_lock);

      if (rv == 0) {
            if(rw == RW_READER) {
                  mutex_enter(&rwlp->mutex);
                  ASSERT(rwlp->thr_count >= 0);
                  rwlp->thr_count++;
                  mutex_exit(&rwlp->mutex);
                  ASSERT(rwlp->rw_owner == NULL);
            } else {
                  ASSERT(rwlp->rw_owner == NULL);
                  ASSERT(rwlp->thr_count == 0);
                  rwlp->thr_count = -1;
                  rwlp->rw_owner = curthread;
            }
            return (1);
      }

      return (0);
}

/*ARGSUSED*/
int
rw_tryupgrade(krwlock_t *rwlp)
{
      ASSERT(rwlp->initialized == B_TRUE);
      ASSERT(rwlp->rw_owner != (void *)-1UL);

      return (0);
}

int rw_lock_held(krwlock_t *rwlp)
{
      int ret;
      mutex_enter(&rwlp->mutex);
      ret = rwlp->thr_count != 0;
      mutex_exit(&rwlp->mutex);
      return ret;
}

/*
 * =========================================================================
 * condition variables
 * =========================================================================
 */
/*ARGSUSED*/
void
cv_init(kcondvar_t *cv, char *name, int type, void *arg)
{
      ASSERT(type == CV_DEFAULT);

      VERIFY(cond_init(cv, type, NULL) == 0);
}

void
cv_destroy(kcondvar_t *cv)
{
      VERIFY(cond_destroy(cv) == 0);
}

void
cv_wait(kcondvar_t *cv, kmutex_t *mp)
{
      ASSERT(mutex_owner(mp) == curthread);
      mp->m_owner = NULL;
      int ret = cond_wait(cv, &mp->m_lock);
      VERIFY(ret == 0 || ret == EINTR);
      mp->m_owner = curthread;
}

clock_t
cv_timedwait(kcondvar_t *cv, kmutex_t *mp, clock_t abstime)
{
      int error;
      struct timespec ts;
      struct timeval tv;
      clock_t delta;

top:
      delta = abstime - lbolt;
      dprintf("thread %li is at cv_timedwait at %.2f with delta %.2f secs\n", curthread, (double) lbolt / hz, (double) delta / hz);
      if (delta <= 0)
            return (-1);

      VERIFY(gettimeofday(&tv, NULL) == 0);

      ts.tv_sec = tv.tv_sec + delta / hz;
      ts.tv_nsec = tv.tv_usec * 1000 + (delta % hz) * (NANOSEC / hz);
      ASSERT(ts.tv_nsec >= 0);

      if(ts.tv_nsec >= NANOSEC) {
            ts.tv_sec++;
            ts.tv_nsec -= NANOSEC;
      }

      ASSERT(mutex_owner(mp) == curthread);
      mp->m_owner = NULL;
      error = pthread_cond_timedwait(cv, &mp->m_lock, &ts);
      mp->m_owner = curthread;

      if (error == EINTR)
            goto top;

      dprintf("thread %li exited cv_timedwait at %.2f (rem = %.2f)\n", curthread, (double) lbolt / hz, (double) (abstime - lbolt) / hz);

      if (error == ETIMEDOUT)
            return (-1);

      ASSERT(error == 0);

      return (1);
}

void
cv_signal(kcondvar_t *cv)
{
      VERIFY(cond_signal(cv) == 0);
}

void
cv_broadcast(kcondvar_t *cv)
{
      VERIFY(cond_broadcast(cv) == 0);
}

/*
 * =========================================================================
 * vnode operations
 * =========================================================================
 */
/*
 * Note: for the xxxat() versions of these functions, we assume that the
 * starting vp is always rootdir (which is true for spa_directory.c, the only
 * ZFS consumer of these interfaces).  We assert this is true, and then emulate
 * them by adding '/' in front of the path.
 */

/*ARGSUSED*/
int
vn_open(char *path, int x1, int flags, int mode, vnode_t **vpp, int x2, int x3)
{
      int fd;
      vnode_t *vp;
      int old_umask;
      struct stat64 st;

      if (!(flags & FCREAT) && stat64(path, &st) == -1)
            return (errno);

      if (flags & FCREAT)
            old_umask = umask(0);

      if (!(flags & FCREAT) && S_ISBLK(st.st_mode)) {
            flags |= O_DIRECT;
            if (flags & FWRITE)
                  flags |= O_EXCL;
      }

      /*
       * The construct 'flags - FREAD' conveniently maps combinations of
       * FREAD and FWRITE to the corresponding O_RDONLY, O_WRONLY, and O_RDWR.
       */
      fd = open64(path, flags - FREAD, mode);

      if (flags & FCREAT)
            (void) umask(old_umask);

      if (fd == -1)
            return (errno);

      *vpp = vp = umem_zalloc(sizeof (vnode_t), UMEM_NOFAIL);

      if (fstat64(fd, &vp->v_stat) == -1) {
            close(fd);
            return (errno);
      }

      (void) fcntl(fd, F_SETFD, FD_CLOEXEC);

      vp->v_fd = fd;
      vp->v_size = vp->v_stat.st_size;
      vp->v_path = spa_strdup(path);

      return (0);
}

/*ARGSUSED*/
int
vn_openat(char *path, int x1, int flags, int mode, vnode_t **vpp, int x2,
    int x3, vnode_t *startvp, int fd)
{
      char *realpath = umem_alloc(strlen(path) + 2, UMEM_NOFAIL);
      int ret;

      ASSERT(startvp == rootdir);
      (void) sprintf(realpath, "/%s", path);

      /* fd ignored for now, need if want to simulate nbmand support */
      ret = vn_open(realpath, x1, flags, mode, vpp, x2, x3);

      umem_free(realpath, strlen(path) + 2);

      return (ret);
}

/*ARGSUSED*/
int
vn_rdwr(int uio, vnode_t *vp, void *addr, ssize_t len, offset_t offset,
      int x1, int x2, rlim64_t x3, void *x4, ssize_t *residp)
{
      ssize_t iolen, split;

      if (uio == UIO_READ) {
            iolen = pread64(vp->v_fd, addr, len, offset);
      } else {
            /*
             * To simulate partial disk writes, we split writes into two
             * system calls so that the process can be killed in between.
             */
            split = (len > 0 ? rand() % len : 0);
            iolen = pwrite64(vp->v_fd, addr, split, offset);
            iolen += pwrite64(vp->v_fd, (char *)addr + split,
                len - split, offset + split);
      }

      if (iolen < 0)
            return (errno);
      if (residp)
            *residp = len - iolen;
      else if (iolen != len)
            return (EIO);
      return (0);
}

void
vn_close(vnode_t *vp)
{
      close(vp->v_fd);
      spa_strfree(vp->v_path);
      umem_free(vp, sizeof (vnode_t));
}

#ifdef ZFS_DEBUG

/*
 * =========================================================================
 * Figure out which debugging statements to print
 * =========================================================================
 */

static char *dprintf_string;
static int dprintf_print_all;

int
dprintf_find_string(const char *string)
{
      char *tmp_str = dprintf_string;
      int len = strlen(string);

      /*
       * Find out if this is a string we want to print.
       * String format: file1.c,function_name1,file2.c,file3.c
       */

      while (tmp_str != NULL) {
            if (strncmp(tmp_str, string, len) == 0 &&
                (tmp_str[len] == ',' || tmp_str[len] == '\0'))
                  return (1);
            tmp_str = strchr(tmp_str, ',');
            if (tmp_str != NULL)
                  tmp_str++; /* Get rid of , */
      }
      return (0);
}

void
dprintf_setup(int *argc, char **argv)
{
      int i, j;

      /*
       * Debugging can be specified two ways: by setting the
       * environment variable ZFS_DEBUG, or by including a
       * "debug=..."  argument on the command line.  The command
       * line setting overrides the environment variable.
       */

      for (i = 1; i < *argc; i++) {
            int len = strlen("debug=");
            /* First look for a command line argument */
            if (strncmp("debug=", argv[i], len) == 0) {
                  dprintf_string = argv[i] + len;
                  /* Remove from args */
                  for (j = i; j < *argc; j++)
                        argv[j] = argv[j+1];
                  argv[j] = NULL;
                  (*argc)--;
            }
      }

      if (dprintf_string == NULL) {
            /* Look for ZFS_DEBUG environment variable */
            dprintf_string = getenv("ZFS_DEBUG");
      }

      /*
       * Are we just turning on all debugging?
       */
      if (dprintf_find_string("on"))
            dprintf_print_all = 1;
}

/*
 * =========================================================================
 * debug printfs
 * =========================================================================
 */
void
__dprintf(const char *file, const char *func, int line, const char *fmt, ...)
{
      const char *newfile;
      va_list adx;

      /*
       * Get rid of annoying "../common/" prefix to filename.
       */
      newfile = strrchr(file, '/');
      if (newfile != NULL) {
            newfile = newfile + 1; /* Get rid of leading / */
      } else {
            newfile = file;
      }

      if (dprintf_print_all ||
          dprintf_find_string(newfile) ||
          dprintf_find_string(func)) {
            /* Print out just the function name if requested */
            flockfile(stdout);
            if (dprintf_find_string("pid"))
                  (void) printf("%d ", getpid());
            if (dprintf_find_string("tid"))
                  (void) printf("%u ", (unsigned int) thr_self());
/*          if (dprintf_find_string("cpu"))
                  (void) printf("%u ", getcpuid());*/
            if (dprintf_find_string("time"))
                  (void) printf("%llu ", gethrtime());
            if (dprintf_find_string("long"))
                  (void) printf("%s, line %d: ", newfile, line);
            (void) printf("%s: ", func);
            va_start(adx, fmt);
            (void) vprintf(fmt, adx);
            va_end(adx);
            funlockfile(stdout);
      }
}

#endif /* ZFS_DEBUG */

/*
 * =========================================================================
 * cmn_err() and panic()
 * =========================================================================
 */
static char ce_prefix[CE_IGNORE][10] = { "", "NOTICE: ", "WARNING: ", "" };
static char ce_suffix[CE_IGNORE][2] = { "", "\n", "\n", "" };

void
vpanic(const char *fmt, va_list adx)
{
      (void) fprintf(stderr, "error: ");
      (void) vfprintf(stderr, fmt, adx);
      (void) fprintf(stderr, "\n");

      abort();    /* think of it as a "user-level crash dump" */
}

void
panic(const char *fmt, ...)
{
      va_list adx;

      va_start(adx, fmt);
      vpanic(fmt, adx);
      va_end(adx);
}

void
vcmn_err(int ce, const char *fmt, va_list adx)
{
      if (ce == CE_PANIC)
            vpanic(fmt, adx);
      if (ce != CE_NOTE) {    /* suppress noise in userland stress testing */
            (void) fprintf(stderr, "%s", ce_prefix[ce]);
            (void) vfprintf(stderr, fmt, adx);
            (void) fprintf(stderr, "%s", ce_suffix[ce]);
      }
}

/*PRINTFLIKE2*/
void
cmn_err(int ce, const char *fmt, ...)
{
      va_list adx;

      va_start(adx, fmt);
      vcmn_err(ce, fmt, adx);
      va_end(adx);
}

/*
 * =========================================================================
 * kobj interfaces
 * =========================================================================
 */
struct _buf *
kobj_open_file(char *name)
{
      struct _buf *file;
      vnode_t *vp;

      /* set vp as the _fd field of the file */
      if (vn_openat(name, UIO_SYSSPACE, FREAD, 0, &vp, 0, 0, rootdir,
          -1) != 0)
            return ((void *)-1UL);

      file = umem_zalloc(sizeof (struct _buf), UMEM_NOFAIL);
      file->_fd = (intptr_t)vp;
      return (file);
}

int
kobj_read_file(struct _buf *file, char *buf, unsigned size, unsigned off)
{
      ssize_t resid;

      vn_rdwr(UIO_READ, (vnode_t *)file->_fd, buf, size, (offset_t)off,
          UIO_SYSSPACE, 0, 0, 0, &resid);

      return (size - resid);
}

void
kobj_close_file(struct _buf *file)
{
      vn_close((vnode_t *)file->_fd);
      umem_free(file, sizeof (struct _buf));
}

int
kobj_get_filesize(struct _buf *file, uint64_t *size)
{
      struct stat64 st;
      vnode_t *vp = (vnode_t *)file->_fd;

      if (fstat64(vp->v_fd, &st) == -1) {
            vn_close(vp);
            return (errno);
      }
      *size = st.st_size;
      return (0);
}

/*
 * =========================================================================
 * misc routines
 * =========================================================================
 */

void
delay(clock_t ticks)
{
      poll(0, 0, ticks * (1000 / hz));
}

/*
 * Find highest one bit set.
 *    Returns bit number + 1 of highest bit that is set, otherwise returns 0.
 * High order bit is 31 (or 63 in _LP64 kernel).
 */
int
highbit(ulong_t i)
{
      register int h = 1;

      if (i == 0)
            return (0);
#ifdef _LP64
      if (i & 0xffffffff00000000ul) {
            h += 32; i >>= 32;
      }
#endif
      if (i & 0xffff0000) {
            h += 16; i >>= 16;
      }
      if (i & 0xff00) {
            h += 8; i >>= 8;
      }
      if (i & 0xf0) {
            h += 4; i >>= 4;
      }
      if (i & 0xc) {
            h += 2; i >>= 2;
      }
      if (i & 0x2) {
            h += 1;
      }
      return (h);
}

static int random_fd = -1, urandom_fd = -1;

static int
random_get_bytes_common(uint8_t *ptr, size_t len, int fd)
{
      size_t resid = len;
      ssize_t bytes;

      ASSERT(fd != -1);

      while (resid != 0) {
            bytes = read(fd, ptr, resid);
            ASSERT3S(bytes, >=, 0);
            ptr += bytes;
            resid -= bytes;
      }

      return (0);
}

int
random_get_bytes(uint8_t *ptr, size_t len)
{
      return (random_get_bytes_common(ptr, len, random_fd));
}

int
random_get_pseudo_bytes(uint8_t *ptr, size_t len)
{
      return (random_get_bytes_common(ptr, len, urandom_fd));
}

int
ddi_strtoul(const char *hw_serial, char **nptr, int base, unsigned long *result)
{
      char *end;

      *result = strtoul(hw_serial, &end, base);
      if (*result == 0)
            return (errno);
      return (0);
}

/*
 * =========================================================================
 * kernel emulation setup & teardown
 * =========================================================================
 */
static int
umem_out_of_memory(void)
{
      char errmsg[] = "out of memory -- generating core dump\n";

      write(fileno(stderr), errmsg, sizeof (errmsg));
      abort();
      return (0);
}

void
kernel_init(int mode)
{
      umem_nofail_callback(umem_out_of_memory);

      physmem = sysconf(_SC_PHYS_PAGES);

      dprintf("physmem = %llu pages (%.2f GB)\n", physmem,
          (double)physmem * sysconf(_SC_PAGE_SIZE) / (1ULL << 30));

      uname(&utsname);
      (void) snprintf(hw_serial, sizeof (hw_serial), "%ld", gethostid());

      VERIFY((random_fd = open("/dev/random", O_RDONLY)) != -1);
      VERIFY((urandom_fd = open("/dev/urandom", O_RDONLY)) != -1);

      system_taskq_init();

      spa_init(mode);
}

void
kernel_fini(void)
{
      spa_fini();

      close(random_fd);
      close(urandom_fd);

      random_fd = -1;
      urandom_fd = -1;
}

int
z_uncompress(void *dst, size_t *dstlen, const void *src, size_t srclen)
{
      int ret;
      uLongf len = *dstlen;

      if ((ret = uncompress(dst, &len, src, srclen)) == Z_OK)
            *dstlen = (size_t)len;

      return (ret);
}

int
z_compress_level(void *dst, size_t *dstlen, const void *src, size_t srclen,
    int level)
{
      int ret;
      uLongf len = *dstlen;

      if ((ret = compress2(dst, &len, src, srclen, level)) == Z_OK)
            *dstlen = (size_t)len;

      return (ret);
}

uid_t
crgetuid(cred_t *cr)
{
      return (0);
}

gid_t
crgetgid(cred_t *cr)
{
      return (0);
}

int
crgetngroups(cred_t *cr)
{
      return (0);
}

gid_t *
crgetgroups(cred_t *cr)
{
      return (NULL);
}

int
zfs_secpolicy_snapshot_perms(const char *name, cred_t *cr)
{
      return (0);
}

int
zfs_secpolicy_rename_perms(const char *from, const char *to, cred_t *cr)
{
      return (0);
}

int
zfs_secpolicy_destroy_perms(const char *name, cred_t *cr)
{
      return (0);
}

ksiddomain_t *
ksid_lookupdomain(const char *dom)
{
      ksiddomain_t *kd;

      kd = umem_zalloc(sizeof (ksiddomain_t), UMEM_NOFAIL);
      kd->kd_name = spa_strdup(dom);
      return (kd);
}

void
ksiddomain_rele(ksiddomain_t *ksid)
{
      spa_strfree(ksid->kd_name);
      umem_free(ksid, sizeof (ksiddomain_t));
}

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