]> git.proxmox.com Git - mirror_zfs-debian.git/commitdiff
Illumos #1950: ztest backwards compatibility testing option.
authorChris Siden <chris.siden@delphix.com>
Tue, 24 Jan 2012 02:43:32 +0000 (18:43 -0800)
committerBrian Behlendorf <behlendorf1@llnl.gov>
Thu, 4 Oct 2012 20:18:53 +0000 (13:18 -0700)
illumos/illumos-gate@420dfc9585ff67e83ee7800a7ad2ebe1a9145983
Illumos changeset: 13571:a5771a96228c

1950 ztest backwards compatibility testing option

Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Adam Leventhal <ahl@delphix.com>
Reviewed by: Matt Ahrens <matt@delphix.com>
Reviewed by: Richard Lowe <richlowe@richlowe.net>
Reviewed by: Robert Mustacchi <rm@joyent.com>
Approved by: Eric Schrock <eric.schrock@delphix.com>

Ported-by: Etienne Dechamps <etienne.dechamps@ovh.net>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
cmd/ztest/ztest.c

index 09d6e9526aa306a27f1fab8f78763c50eb9250d3..8655b237cd996d92a96b456bfa50ec3b0c4885b8 100644 (file)
@@ -20,7 +20,7 @@
  */
 /*
  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
- * Copyright (c) 2011 by Delphix. All rights reserved.
+ * Copyright (c) 2012 by Delphix. All rights reserved.
  * Copyright 2011 Nexenta Systems, Inc.  All rights reserved.
  */
 
@@ -51,7 +51,9 @@
  *     At random times, the child self-immolates with a SIGKILL.
  *     This is the software equivalent of pulling the power cord.
  *     The parent then runs the test again, using the existing
- *     storage pool, as many times as desired.
+ *     storage pool, as many times as desired. If backwards compatability
+ *     testing is enabled ztest will sometimes run the "older" version
+ *     of ztest after a SIGKILL.
  *
  * (6) To verify that we don't have future leaks or temporal incursions,
  *     many of the functional tests record the transaction group number
  * You can ask more more vdevs [-v], datasets [-d], or threads [-t]
  * to increase the pool capacity, fanout, and overall stress level.
  *
- * The -N(okill) option will suppress kills, so each child runs to completion.
- * This can be useful when you're trying to distinguish temporal incursions
- * from plain old race conditions.
+ * Use the -k option to set the desired frequency of kills.
+ *
+ * When ztest invokes itself it passes all relevant information through a
+ * temporary file which is mmap-ed in the child process. This allows shared
+ * memory to survive the exec syscall. The ztest_shared_hdr_t struct is always
+ * stored at offset 0 of this file and contains information on the size and
+ * number of shared structures in the file. The information stored in this file
+ * must remain backwards compatible with older versions of ztest so that
+ * ztest can invoke them during backwards compatibility testing (-B).
  */
 
 #include <sys/zfs_context.h>
 #include <sys/fs/zfs.h>
 #include <libnvpair.h>
 
-static char cmdname[] = "ztest";
-static char *zopt_pool = cmdname;
-
-static uint64_t zopt_vdevs = 5;
-static uint64_t zopt_vdevtime;
-static int zopt_ashift = SPA_MINBLOCKSHIFT;
-static int zopt_mirrors = 2;
-static int zopt_raidz = 4;
-static int zopt_raidz_parity = 1;
-static size_t zopt_vdev_size = SPA_MINDEVSIZE;
-static int zopt_datasets = 7;
-static int zopt_threads = 23;
-static uint64_t zopt_passtime = 60;    /* 60 seconds */
-static uint64_t zopt_killrate = 70;    /* 70% kill rate */
-static int zopt_verbose = 0;
-static int zopt_init = 1;
-static char *zopt_dir = "/tmp";
-static uint64_t zopt_time = 300;       /* 5 minutes */
-static uint64_t zopt_maxloops = 50;    /* max loops during spa_freeze() */
+#define        ZTEST_FD_DATA 3
+#define        ZTEST_FD_RAND 4
+
+typedef struct ztest_shared_hdr {
+       uint64_t        zh_hdr_size;
+       uint64_t        zh_opts_size;
+       uint64_t        zh_size;
+       uint64_t        zh_stats_size;
+       uint64_t        zh_stats_count;
+       uint64_t        zh_ds_size;
+       uint64_t        zh_ds_count;
+} ztest_shared_hdr_t;
+
+static ztest_shared_hdr_t *ztest_shared_hdr;
+
+typedef struct ztest_shared_opts {
+       char zo_pool[MAXNAMELEN];
+       char zo_dir[MAXNAMELEN];
+       char zo_alt_ztest[MAXNAMELEN];
+       char zo_alt_libpath[MAXNAMELEN];
+       uint64_t zo_vdevs;
+       uint64_t zo_vdevtime;
+       size_t zo_vdev_size;
+       int zo_ashift;
+       int zo_mirrors;
+       int zo_raidz;
+       int zo_raidz_parity;
+       int zo_datasets;
+       int zo_threads;
+       uint64_t zo_passtime;
+       uint64_t zo_killrate;
+       int zo_verbose;
+       int zo_init;
+       uint64_t zo_time;
+       uint64_t zo_maxloops;
+       uint64_t zo_metaslab_gang_bang;
+} ztest_shared_opts_t;
+
+static const ztest_shared_opts_t ztest_opts_defaults = {
+       .zo_pool = { 'z', 't', 'e', 's', 't', '\0' },
+       .zo_dir = { '/', 't', 'm', 'p', '\0' },
+       .zo_alt_ztest = { '\0' },
+       .zo_alt_libpath = { '\0' },
+       .zo_vdevs = 5,
+       .zo_ashift = SPA_MINBLOCKSHIFT,
+       .zo_mirrors = 2,
+       .zo_raidz = 4,
+       .zo_raidz_parity = 1,
+       .zo_vdev_size = SPA_MINDEVSIZE,
+       .zo_datasets = 7,
+       .zo_threads = 23,
+       .zo_passtime = 60,              /* 60 seconds */
+       .zo_killrate = 70,              /* 70% kill rate */
+       .zo_verbose = 0,
+       .zo_init = 1,
+       .zo_time = 300,                 /* 5 minutes */
+       .zo_maxloops = 50,              /* max loops during spa_freeze() */
+       .zo_metaslab_gang_bang = 32 << 10
+};
+
+extern uint64_t metaslab_gang_bang;
+extern uint64_t metaslab_df_alloc_threshold;
+
+static ztest_shared_opts_t *ztest_shared_opts;
+static ztest_shared_opts_t ztest_opts;
+
+typedef struct ztest_shared_ds {
+       uint64_t        zd_seq;
+} ztest_shared_ds_t;
+
+static ztest_shared_ds_t *ztest_shared_ds;
+#define        ZTEST_GET_SHARED_DS(d) (&ztest_shared_ds[d])
 
 #define        BT_MAGIC        0x123456789abcdefULL
-#define        MAXFAULTS() (MAX(zs->zs_mirrors, 1) * (zopt_raidz_parity + 1) - 1)
+#define        MAXFAULTS() \
+       (MAX(zs->zs_mirrors, 1) * (ztest_opts.zo_raidz_parity + 1) - 1)
 
 enum ztest_io_type {
        ZTEST_IO_WRITE_TAG,
@@ -206,10 +268,10 @@ typedef struct ztest_od {
  * Per-dataset state.
  */
 typedef struct ztest_ds {
+       ztest_shared_ds_t *zd_shared;
        objset_t        *zd_os;
        krwlock_t       zd_zilog_lock;
        zilog_t         *zd_zilog;
-       uint64_t        zd_seq;
        ztest_od_t      *zd_od;         /* debugging aid */
        char            zd_name[MAXNAMELEN];
        kmutex_t        zd_dirobj_lock;
@@ -226,11 +288,17 @@ typedef struct ztest_info {
        ztest_func_t    *zi_func;       /* test function */
        uint64_t        zi_iters;       /* iterations per execution */
        uint64_t        *zi_interval;   /* execute every <interval> seconds */
-       uint64_t        zi_call_count;  /* per-pass count */
-       uint64_t        zi_call_time;   /* per-pass time */
-       uint64_t        zi_call_next;   /* next time to call this function */
 } ztest_info_t;
 
+typedef struct ztest_shared_callstate {
+       uint64_t        zc_count;       /* per-pass count */
+       uint64_t        zc_time;        /* per-pass time */
+       uint64_t        zc_next;        /* next time to call this function */
+} ztest_shared_callstate_t;
+
+static ztest_shared_callstate_t *ztest_shared_callstate;
+#define        ZTEST_GET_SHARED_CALLSTATE(c) (&ztest_shared_callstate[c])
+
 /*
  * Note: these aren't static because we want dladdr() to work.
  */
@@ -304,8 +372,10 @@ ztest_info_t ztest_info[] = {
        { ztest_dsl_dataset_promote_busy,       1,      &zopt_rarely    },
        { ztest_vdev_attach_detach,             1,      &zopt_rarely },
        { ztest_vdev_LUN_growth,                1,      &zopt_rarely    },
-       { ztest_vdev_add_remove,                1,      &zopt_vdevtime },
-       { ztest_vdev_aux_add_remove,            1,      &zopt_vdevtime  },
+       { ztest_vdev_add_remove,                1,
+           &ztest_opts.zo_vdevtime                             },
+       { ztest_vdev_aux_add_remove,            1,
+           &ztest_opts.zo_vdevtime                             },
 };
 
 #define        ZTEST_FUNCS     (sizeof (ztest_info) / sizeof (ztest_info_t))
@@ -323,8 +393,7 @@ typedef struct ztest_cb_list {
  * Stuff we need to share writably between parent and child.
  */
 typedef struct ztest_shared {
-       char            *zs_pool;
-       spa_t           *zs_spa;
+       boolean_t       zs_do_init;
        hrtime_t        zs_proc_start;
        hrtime_t        zs_proc_stop;
        hrtime_t        zs_thread_start;
@@ -335,13 +404,11 @@ typedef struct ztest_shared {
        uint64_t        zs_vdev_aux;
        uint64_t        zs_alloc;
        uint64_t        zs_space;
-       uint64_t        zs_guid;
-       kmutex_t        zs_vdev_lock;
-       krwlock_t       zs_name_lock;
-       ztest_info_t    zs_info[ZTEST_FUNCS];
        uint64_t        zs_splits;
        uint64_t        zs_mirrors;
-       ztest_ds_t      zs_zd[];
+       uint64_t        zs_metaslab_sz;
+       uint64_t        zs_metaslab_df_alloc_threshold;
+       uint64_t        zs_guid;
 } ztest_shared_t;
 
 #define        ID_PARALLEL     -1ULL
@@ -349,11 +416,14 @@ typedef struct ztest_shared {
 static char ztest_dev_template[] = "%s/%s.%llua";
 static char ztest_aux_template[] = "%s/%s.%s.%llu";
 ztest_shared_t *ztest_shared;
-uint64_t *ztest_seq;
 
-static int ztest_random_fd;
-static int ztest_dump_core = 1;
+static spa_t *ztest_spa = NULL;
+static ztest_ds_t *ztest_ds;
+
+static kmutex_t ztest_vdev_lock;
+static krwlock_t ztest_name_lock;
 
+static boolean_t ztest_dump_core = B_TRUE;
 static boolean_t ztest_exiting;
 
 /* Global commit callback list */
@@ -377,7 +447,6 @@ static int zc_cb_counter = 0;
 
 extern uint64_t metaslab_gang_bang;
 extern uint64_t metaslab_df_alloc_threshold;
-static uint64_t metaslab_sz;
 
 enum ztest_object {
        ZTEST_META_DNODE = 0,
@@ -492,12 +561,14 @@ nicenumtoull(const char *buf)
 static void
 usage(boolean_t requested)
 {
+       const ztest_shared_opts_t *zo = &ztest_opts_defaults;
+
        char nice_vdev_size[10];
        char nice_gang_bang[10];
        FILE *fp = requested ? stdout : stderr;
 
-       nicenum(zopt_vdev_size, nice_vdev_size);
-       nicenum(metaslab_gang_bang, nice_gang_bang);
+       nicenum(zo->zo_vdev_size, nice_vdev_size);
+       nicenum(zo->zo_metaslab_gang_bang, nice_gang_bang);
 
        (void) fprintf(fp, "Usage: %s\n"
            "\t[-v vdevs (default: %llu)]\n"
@@ -518,39 +589,43 @@ usage(boolean_t requested)
            "\t[-T time (default: %llu sec)] total run time\n"
            "\t[-F freezeloops (default: %llu)] max loops in spa_freeze()\n"
            "\t[-P passtime (default: %llu sec)] time per pass\n"
+           "\t[-B alt_ztest (default: <none>)] alternate ztest path\n"
            "\t[-h] (print help)\n"
            "",
-           cmdname,
-           (u_longlong_t)zopt_vdevs,                   /* -v */
+           zo->zo_pool,
+           (u_longlong_t)zo->zo_vdevs,                 /* -v */
            nice_vdev_size,                             /* -s */
-           zopt_ashift,                                /* -a */
-           zopt_mirrors,                               /* -m */
-           zopt_raidz,                                 /* -r */
-           zopt_raidz_parity,                          /* -R */
-           zopt_datasets,                              /* -d */
-           zopt_threads,                               /* -t */
+           zo->zo_ashift,                              /* -a */
+           zo->zo_mirrors,                             /* -m */
+           zo->zo_raidz,                               /* -r */
+           zo->zo_raidz_parity,                        /* -R */
+           zo->zo_datasets,                            /* -d */
+           zo->zo_threads,                             /* -t */
            nice_gang_bang,                             /* -g */
-           zopt_init,                                  /* -i */
-           (u_longlong_t)zopt_killrate,                /* -k */
-           zopt_pool,                                  /* -p */
-           zopt_dir,                                   /* -f */
-           (u_longlong_t)zopt_time,                    /* -T */
-           (u_longlong_t)zopt_maxloops,                /* -F */
-           (u_longlong_t)zopt_passtime);               /* -P */
+           zo->zo_init,                                /* -i */
+           (u_longlong_t)zo->zo_killrate,              /* -k */
+           zo->zo_pool,                                /* -p */
+           zo->zo_dir,                                 /* -f */
+           (u_longlong_t)zo->zo_time,                  /* -T */
+           (u_longlong_t)zo->zo_maxloops,              /* -F */
+           (u_longlong_t)zo->zo_passtime);
        exit(requested ? 0 : 1);
 }
 
 static void
 process_options(int argc, char **argv)
 {
+       char *path;
+       ztest_shared_opts_t *zo = &ztest_opts;
+
        int opt;
        uint64_t value;
+       char altdir[MAXNAMELEN] = { 0 };
 
-       /* By default, test gang blocks for blocks 32K and greater */
-       metaslab_gang_bang = 32 << 10;
+       bcopy(&ztest_opts_defaults, zo, sizeof (*zo));
 
        while ((opt = getopt(argc, argv,
-           "v:s:a:m:r:R:d:t:g:i:k:p:f:VET:P:hF:")) != EOF) {
+           "v:s:a:m:r:R:d:t:g:i:k:p:f:VET:P:hF:B:")) != EOF) {
                value = 0;
                switch (opt) {
                case 'v':
@@ -571,58 +646,71 @@ process_options(int argc, char **argv)
                }
                switch (opt) {
                case 'v':
-                       zopt_vdevs = value;
+                       zo->zo_vdevs = value;
                        break;
                case 's':
-                       zopt_vdev_size = MAX(SPA_MINDEVSIZE, value);
+                       zo->zo_vdev_size = MAX(SPA_MINDEVSIZE, value);
                        break;
                case 'a':
-                       zopt_ashift = value;
+                       zo->zo_ashift = value;
                        break;
                case 'm':
-                       zopt_mirrors = value;
+                       zo->zo_mirrors = value;
                        break;
                case 'r':
-                       zopt_raidz = MAX(1, value);
+                       zo->zo_raidz = MAX(1, value);
                        break;
                case 'R':
-                       zopt_raidz_parity = MIN(MAX(value, 1), 3);
+                       zo->zo_raidz_parity = MIN(MAX(value, 1), 3);
                        break;
                case 'd':
-                       zopt_datasets = MAX(1, value);
+                       zo->zo_datasets = MAX(1, value);
                        break;
                case 't':
-                       zopt_threads = MAX(1, value);
+                       zo->zo_threads = MAX(1, value);
                        break;
                case 'g':
-                       metaslab_gang_bang = MAX(SPA_MINBLOCKSIZE << 1, value);
+                       zo->zo_metaslab_gang_bang = MAX(SPA_MINBLOCKSIZE << 1,
+                           value);
                        break;
                case 'i':
-                       zopt_init = value;
+                       zo->zo_init = value;
                        break;
                case 'k':
-                       zopt_killrate = value;
+                       zo->zo_killrate = value;
                        break;
                case 'p':
-                       zopt_pool = strdup(optarg);
+                       (void) strlcpy(zo->zo_pool, optarg,
+                           sizeof (zo->zo_pool));
                        break;
                case 'f':
-                       zopt_dir = strdup(optarg);
+                       path = realpath(optarg, NULL);
+                       if (path == NULL) {
+                               (void) fprintf(stderr, "error: %s: %s\n",
+                                   optarg, strerror(errno));
+                               usage(B_FALSE);
+                       } else {
+                               (void) strlcpy(zo->zo_dir, path,
+                                   sizeof (zo->zo_dir));
+                       }
                        break;
                case 'V':
-                       zopt_verbose++;
+                       zo->zo_verbose++;
                        break;
                case 'E':
-                       zopt_init = 0;
+                       zo->zo_init = 0;
                        break;
                case 'T':
-                       zopt_time = value;
+                       zo->zo_time = value;
                        break;
                case 'P':
-                       zopt_passtime = MAX(1, value);
+                       zo->zo_passtime = MAX(1, value);
                        break;
                case 'F':
-                       zopt_maxloops = MAX(1, value);
+                       zo->zo_maxloops = MAX(1, value);
+                       break;
+               case 'B':
+                       (void) strlcpy(altdir, optarg, sizeof (altdir));
                        break;
                case 'h':
                        usage(B_TRUE);
@@ -634,17 +722,59 @@ process_options(int argc, char **argv)
                }
        }
 
-       zopt_raidz_parity = MIN(zopt_raidz_parity, zopt_raidz - 1);
+       zo->zo_raidz_parity = MIN(zo->zo_raidz_parity, zo->zo_raidz - 1);
 
-       zopt_vdevtime = (zopt_vdevs > 0 ? zopt_time * NANOSEC / zopt_vdevs :
+       zo->zo_vdevtime =
+           (zo->zo_vdevs > 0 ? zo->zo_time * NANOSEC / zo->zo_vdevs :
            UINT64_MAX >> 2);
+
+       if (strlen(altdir) > 0) {
+               char cmd[MAXNAMELEN];
+               char realaltdir[MAXNAMELEN];
+               char *bin;
+               char *ztest;
+               char *isa;
+               int isalen;
+
+               (void) realpath(getexecname(), cmd);
+               if (0 != access(altdir, F_OK)) {
+                       ztest_dump_core = B_FALSE;
+                       fatal(B_TRUE, "invalid alternate ztest path: %s",
+                           altdir);
+               }
+               VERIFY(NULL != realpath(altdir, realaltdir));
+
+               /*
+                * 'cmd' should be of the form "<anything>/usr/bin/<isa>/ztest".
+                * We want to extract <isa> to determine if we should use
+                * 32 or 64 bit binaries.
+                */
+               bin = strstr(cmd, "/usr/bin/");
+               ztest = strstr(bin, "/ztest");
+               isa = bin + 9;
+               isalen = ztest - isa;
+               (void) snprintf(zo->zo_alt_ztest, sizeof (zo->zo_alt_ztest),
+                   "%s/usr/bin/%.*s/ztest", realaltdir, isalen, isa);
+               (void) snprintf(zo->zo_alt_libpath, sizeof (zo->zo_alt_libpath),
+                   "%s/usr/lib/%.*s", realaltdir, isalen, isa);
+
+               if (0 != access(zo->zo_alt_ztest, X_OK)) {
+                       ztest_dump_core = B_FALSE;
+                       fatal(B_TRUE, "invalid alternate ztest: %s",
+                           zo->zo_alt_ztest);
+               } else if (0 != access(zo->zo_alt_libpath, X_OK)) {
+                       ztest_dump_core = B_FALSE;
+                       fatal(B_TRUE, "invalid alternate lib directory %s",
+                           zo->zo_alt_libpath);
+               }
+       }
 }
 
 static void
 ztest_kill(ztest_shared_t *zs)
 {
-       zs->zs_alloc = metaslab_class_get_alloc(spa_normal_class(zs->zs_spa));
-       zs->zs_space = metaslab_class_get_space(spa_normal_class(zs->zs_spa));
+       zs->zs_alloc = metaslab_class_get_alloc(spa_normal_class(ztest_spa));
+       zs->zs_space = metaslab_class_get_space(spa_normal_class(ztest_spa));
        (void) kill(getpid(), SIGKILL);
 }
 
@@ -656,7 +786,7 @@ ztest_random(uint64_t range)
        if (range == 0)
                return (0);
 
-       if (read(ztest_random_fd, &r, sizeof (r)) != sizeof (r))
+       if (read(ZTEST_FD_RAND, &r, sizeof (r)) != sizeof (r))
                fatal(1, "short read from /dev/urandom");
 
        return (r % range);
@@ -672,9 +802,9 @@ ztest_record_enospc(const char *s)
 static uint64_t
 ztest_get_ashift(void)
 {
-       if (zopt_ashift == 0)
+       if (ztest_opts.zo_ashift == 0)
                return (SPA_MINBLOCKSHIFT + ztest_random(3));
-       return (zopt_ashift);
+       return (ztest_opts.zo_ashift);
 }
 
 static nvlist_t *
@@ -694,12 +824,14 @@ make_vdev_file(char *path, char *aux, size_t size, uint64_t ashift)
 
                if (aux != NULL) {
                        vdev = ztest_shared->zs_vdev_aux;
-                       (void) sprintf(path, ztest_aux_template,
-                           zopt_dir, zopt_pool, aux, vdev);
+                       (void) snprintf(path, MAXPATHLEN,
+                           ztest_aux_template, ztest_opts.zo_dir,
+                           ztest_opts.zo_pool, aux, vdev);
                } else {
                        vdev = ztest_shared->zs_vdev_next_leaf++;
-                       (void) sprintf(path, ztest_dev_template,
-                           zopt_dir, zopt_pool, vdev);
+                       (void) snprintf(path, MAXPATHLEN,
+                           ztest_dev_template, ztest_opts.zo_dir,
+                           ztest_opts.zo_pool, vdev);
                }
        }
 
@@ -738,7 +870,7 @@ make_vdev_raidz(char *path, char *aux, size_t size, uint64_t ashift, int r)
        VERIFY(nvlist_add_string(raidz, ZPOOL_CONFIG_TYPE,
            VDEV_TYPE_RAIDZ) == 0);
        VERIFY(nvlist_add_uint64(raidz, ZPOOL_CONFIG_NPARITY,
-           zopt_raidz_parity) == 0);
+           ztest_opts.zo_raidz_parity) == 0);
        VERIFY(nvlist_add_nvlist_array(raidz, ZPOOL_CONFIG_CHILDREN,
            child, r) == 0);
 
@@ -877,7 +1009,7 @@ ztest_dsl_prop_set_uint64(char *osname, zfs_prop_t prop, uint64_t value,
        VERIFY3U(dsl_prop_get(osname, propname, sizeof (curval),
            1, &curval, setpoint), ==, 0);
 
-       if (zopt_verbose >= 6) {
+       if (ztest_opts.zo_verbose >= 6) {
                VERIFY(zfs_prop_index_to_string(prop, curval, &valname) == 0);
                (void) printf("%s %s = %s at '%s'\n",
                    osname, propname, valname, setpoint);
@@ -888,9 +1020,9 @@ ztest_dsl_prop_set_uint64(char *osname, zfs_prop_t prop, uint64_t value,
 }
 
 static int
-ztest_spa_prop_set_uint64(ztest_shared_t *zs, zpool_prop_t prop, uint64_t value)
+ztest_spa_prop_set_uint64(zpool_prop_t prop, uint64_t value)
 {
-       spa_t *spa = zs->zs_spa;
+       spa_t *spa = ztest_spa;
        nvlist_t *props = NULL;
        int error;
 
@@ -1012,14 +1144,17 @@ ztest_range_unlock(rl_t *rl)
 }
 
 static void
-ztest_zd_init(ztest_ds_t *zd, objset_t *os)
+ztest_zd_init(ztest_ds_t *zd, ztest_shared_ds_t *szd, objset_t *os)
 {
        zd->zd_os = os;
        zd->zd_zilog = dmu_objset_zil(os);
-       zd->zd_seq = 0;
+       zd->zd_shared = szd;
        dmu_objset_name(os, zd->zd_name);
        int l;
 
+       if (zd->zd_shared != NULL)
+               zd->zd_shared->zd_seq = 0;
+
        rw_init(&zd->zd_zilog_lock, NULL, RW_DEFAULT, NULL);
        mutex_init(&zd->zd_dirobj_lock, NULL, MUTEX_DEFAULT, NULL);
 
@@ -2113,8 +2248,9 @@ ztest_zil_commit(ztest_ds_t *zd, uint64_t id)
         * will verify that the log really does contain this record.
         */
        mutex_enter(&zilog->zl_lock);
-       ASSERT(zd->zd_seq <= zilog->zl_commit_lr_seq);
-       zd->zd_seq = zilog->zl_commit_lr_seq;
+       ASSERT(zd->zd_shared != NULL);
+       ASSERT3U(zd->zd_shared->zd_seq, <=, zilog->zl_commit_lr_seq);
+       zd->zd_shared->zd_seq = zilog->zl_commit_lr_seq;
        mutex_exit(&zilog->zl_lock);
 
        (void) rw_exit(&zd->zd_zilog_lock);
@@ -2151,7 +2287,7 @@ ztest_zil_remount(ztest_ds_t *zd, uint64_t id)
 void
 ztest_spa_create_destroy(ztest_ds_t *zd, uint64_t id)
 {
-       ztest_shared_t *zs = ztest_shared;
+       ztest_shared_opts_t *zo = &ztest_opts;
        spa_t *spa;
        nvlist_t *nvroot;
 
@@ -2175,15 +2311,15 @@ ztest_spa_create_destroy(ztest_ds_t *zd, uint64_t id)
         * Attempt to create an existing pool.  It shouldn't matter
         * what's in the nvroot; we should fail with EEXIST.
         */
-       (void) rw_enter(&zs->zs_name_lock, RW_READER);
+       (void) rw_enter(&ztest_name_lock, RW_READER);
        nvroot = make_vdev_root("/dev/bogus", NULL, 0, 0, 0, 0, 0, 1);
-       VERIFY3U(EEXIST, ==, spa_create(zs->zs_pool, nvroot, NULL, NULL, NULL));
+       VERIFY3U(EEXIST, ==, spa_create(zo->zo_pool, nvroot, NULL, NULL, NULL));
        nvlist_free(nvroot);
-       VERIFY3U(0, ==, spa_open(zs->zs_pool, &spa, FTAG));
-       VERIFY3U(EBUSY, ==, spa_destroy(zs->zs_pool));
+       VERIFY3U(0, ==, spa_open(zo->zo_pool, &spa, FTAG));
+       VERIFY3U(EBUSY, ==, spa_destroy(zo->zo_pool));
        spa_close(spa, FTAG);
 
-       (void) rw_exit(&zs->zs_name_lock);
+       (void) rw_exit(&ztest_name_lock);
 }
 
 static vdev_t *
@@ -2231,14 +2367,15 @@ void
 ztest_vdev_add_remove(ztest_ds_t *zd, uint64_t id)
 {
        ztest_shared_t *zs = ztest_shared;
-       spa_t *spa = zs->zs_spa;
+       spa_t *spa = ztest_spa;
        uint64_t leaves;
        uint64_t guid;
        nvlist_t *nvroot;
        int error;
 
-       mutex_enter(&zs->zs_vdev_lock);
-       leaves = MAX(zs->zs_mirrors + zs->zs_splits, 1) * zopt_raidz;
+       mutex_enter(&ztest_vdev_lock);
+       leaves =
+               MAX(zs->zs_mirrors + zs->zs_splits, 1) * ztest_opts.zo_raidz;
 
        spa_config_enter(spa, SCL_VDEV, FTAG, RW_READER);
 
@@ -2263,9 +2400,9 @@ ztest_vdev_add_remove(ztest_ds_t *zd, uint64_t id)
                 * dmu_objset_destroy() to fail with EBUSY thus
                 * leaving the dataset in an inconsistent state.
                 */
-               rw_enter(&ztest_shared->zs_name_lock, RW_WRITER);
+               rw_enter(&ztest_name_lock, RW_WRITER);
                error = spa_vdev_remove(spa, guid, B_FALSE);
-               rw_exit(&ztest_shared->zs_name_lock);
+               rw_exit(&ztest_name_lock);
 
                if (error && error != EEXIST)
                        fatal(0, "spa_vdev_remove() = %d", error);
@@ -2275,8 +2412,10 @@ ztest_vdev_add_remove(ztest_ds_t *zd, uint64_t id)
                /*
                 * Make 1/4 of the devices be log devices.
                 */
-               nvroot = make_vdev_root(NULL, NULL, zopt_vdev_size, 0,
-                   ztest_random(4) == 0, zopt_raidz, zs->zs_mirrors, 1);
+               nvroot = make_vdev_root(NULL, NULL,
+                   ztest_opts.zo_vdev_size, 0,
+                   ztest_random(4) == 0, ztest_opts.zo_raidz,
+                   zs->zs_mirrors, 1);
 
                error = spa_vdev_add(spa, nvroot);
                nvlist_free(nvroot);
@@ -2287,7 +2426,7 @@ ztest_vdev_add_remove(ztest_ds_t *zd, uint64_t id)
                        fatal(0, "spa_vdev_add() = %d", error);
        }
 
-       mutex_exit(&ztest_shared->zs_vdev_lock);
+       mutex_exit(&ztest_vdev_lock);
 }
 
 /*
@@ -2298,7 +2437,7 @@ void
 ztest_vdev_aux_add_remove(ztest_ds_t *zd, uint64_t id)
 {
        ztest_shared_t *zs = ztest_shared;
-       spa_t *spa = zs->zs_spa;
+       spa_t *spa = ztest_spa;
        vdev_t *rvd = spa->spa_root_vdev;
        spa_aux_vdev_t *sav;
        char *aux;
@@ -2316,7 +2455,7 @@ ztest_vdev_aux_add_remove(ztest_ds_t *zd, uint64_t id)
                aux = ZPOOL_CONFIG_L2CACHE;
        }
 
-       mutex_enter(&zs->zs_vdev_lock);
+       mutex_enter(&ztest_vdev_lock);
 
        spa_config_enter(spa, SCL_VDEV, FTAG, RW_READER);
 
@@ -2332,8 +2471,9 @@ ztest_vdev_aux_add_remove(ztest_ds_t *zd, uint64_t id)
                zs->zs_vdev_aux = 0;
                for (;;) {
                        int c;
-                       (void) sprintf(path, ztest_aux_template, zopt_dir,
-                           zopt_pool, aux, zs->zs_vdev_aux);
+                       (void) snprintf(path, sizeof (path), ztest_aux_template,
+                           ztest_opts.zo_dir, ztest_opts.zo_pool, aux,
+                           zs->zs_vdev_aux);
                        for (c = 0; c < sav->sav_count; c++)
                                if (strcmp(sav->sav_vdevs[c]->vdev_path,
                                    path) == 0)
@@ -2352,7 +2492,7 @@ ztest_vdev_aux_add_remove(ztest_ds_t *zd, uint64_t id)
                 * Add a new device.
                 */
                nvlist_t *nvroot = make_vdev_root(NULL, aux,
-                   (zopt_vdev_size * 5) / 4, 0, 0, 0, 0, 1);
+                   (ztest_opts.zo_vdev_size * 5) / 4, 0, 0, 0, 0, 1);
                error = spa_vdev_add(spa, nvroot);
                if (error != 0)
                        fatal(0, "spa_vdev_add(%p) = %d", nvroot, error);
@@ -2371,7 +2511,7 @@ ztest_vdev_aux_add_remove(ztest_ds_t *zd, uint64_t id)
                        fatal(0, "spa_vdev_remove(%llu) = %d", guid, error);
        }
 
-       mutex_exit(&zs->zs_vdev_lock);
+       mutex_exit(&ztest_vdev_lock);
 
        umem_free(path, MAXPATHLEN);
 }
@@ -2384,17 +2524,17 @@ void
 ztest_split_pool(ztest_ds_t *zd, uint64_t id)
 {
        ztest_shared_t *zs = ztest_shared;
-       spa_t *spa = zs->zs_spa;
+       spa_t *spa = ztest_spa;
        vdev_t *rvd = spa->spa_root_vdev;
        nvlist_t *tree, **child, *config, *split, **schild;
        uint_t c, children, schildren = 0, lastlogid = 0;
        int error = 0;
 
-       mutex_enter(&zs->zs_vdev_lock);
+       mutex_enter(&ztest_vdev_lock);
 
        /* ensure we have a useable config; mirrors of raidz aren't supported */
-       if (zs->zs_mirrors < 3 || zopt_raidz > 1) {
-               mutex_exit(&zs->zs_vdev_lock);
+       if (zs->zs_mirrors < 3 || ztest_opts.zo_raidz > 1) {
+               mutex_exit(&ztest_vdev_lock);
                return;
        }
 
@@ -2453,9 +2593,9 @@ ztest_split_pool(ztest_ds_t *zd, uint64_t id)
 
        spa_config_exit(spa, SCL_VDEV, FTAG);
 
-       (void) rw_enter(&zs->zs_name_lock, RW_WRITER);
+       (void) rw_enter(&ztest_name_lock, RW_WRITER);
        error = spa_vdev_split_mirror(spa, "splitp", config, NULL, B_FALSE);
-       (void) rw_exit(&zs->zs_name_lock);
+       (void) rw_exit(&ztest_name_lock);
 
        nvlist_free(config);
 
@@ -2468,7 +2608,7 @@ ztest_split_pool(ztest_ds_t *zd, uint64_t id)
                ++zs->zs_splits;
                --zs->zs_mirrors;
        }
-       mutex_exit(&zs->zs_vdev_lock);
+       mutex_exit(&ztest_vdev_lock);
 
 }
 
@@ -2480,7 +2620,7 @@ void
 ztest_vdev_attach_detach(ztest_ds_t *zd, uint64_t id)
 {
        ztest_shared_t *zs = ztest_shared;
-       spa_t *spa = zs->zs_spa;
+       spa_t *spa = ztest_spa;
        spa_aux_vdev_t *sav = &spa->spa_spares;
        vdev_t *rvd = spa->spa_root_vdev;
        vdev_t *oldvd, *newvd, *pvd;
@@ -2500,8 +2640,8 @@ ztest_vdev_attach_detach(ztest_ds_t *zd, uint64_t id)
        oldpath = umem_alloc(MAXPATHLEN, UMEM_NOFAIL);
        newpath = umem_alloc(MAXPATHLEN, UMEM_NOFAIL);
 
-       mutex_enter(&zs->zs_vdev_lock);
-       leaves = MAX(zs->zs_mirrors, 1) * zopt_raidz;
+       mutex_enter(&ztest_vdev_lock);
+       leaves = MAX(zs->zs_mirrors, 1) * ztest_opts.zo_raidz;
 
        spa_config_enter(spa, SCL_VDEV, FTAG, RW_READER);
 
@@ -2527,12 +2667,12 @@ ztest_vdev_attach_detach(ztest_ds_t *zd, uint64_t id)
        if (zs->zs_mirrors >= 1) {
                ASSERT(oldvd->vdev_ops == &vdev_mirror_ops);
                ASSERT(oldvd->vdev_children >= zs->zs_mirrors);
-               oldvd = oldvd->vdev_child[leaf / zopt_raidz];
+               oldvd = oldvd->vdev_child[leaf / ztest_opts.zo_raidz];
        }
-       if (zopt_raidz > 1) {
+       if (ztest_opts.zo_raidz > 1) {
                ASSERT(oldvd->vdev_ops == &vdev_raidz_ops);
-               ASSERT(oldvd->vdev_children == zopt_raidz);
-               oldvd = oldvd->vdev_child[leaf % zopt_raidz];
+               ASSERT(oldvd->vdev_children == ztest_opts.zo_raidz);
+               oldvd = oldvd->vdev_child[leaf % ztest_opts.zo_raidz];
        }
 
        /*
@@ -2574,7 +2714,8 @@ ztest_vdev_attach_detach(ztest_ds_t *zd, uint64_t id)
                (void) strcpy(newpath, newvd->vdev_path);
        } else {
                (void) snprintf(newpath, MAXPATHLEN, ztest_dev_template,
-                   zopt_dir, zopt_pool, top * leaves + leaf);
+                   ztest_opts.zo_dir, ztest_opts.zo_pool,
+                   top * leaves + leaf);
                if (ztest_random(2) == 0)
                        newpath[strlen(newpath) - 1] = 'b';
                newvd = vdev_lookup_by_path(rvd, newpath);
@@ -2653,7 +2794,7 @@ ztest_vdev_attach_detach(ztest_ds_t *zd, uint64_t id)
                    (longlong_t)newsize, replacing, error, expected_error);
        }
 out:
-       mutex_exit(&zs->zs_vdev_lock);
+       mutex_exit(&ztest_vdev_lock);
 
        umem_free(oldpath, MAXPATHLEN);
        umem_free(newpath, MAXPATHLEN);
@@ -2679,7 +2820,7 @@ grow_vdev(vdev_t *vd, void *arg)
        fsize = lseek(fd, 0, SEEK_END);
        VERIFY(ftruncate(fd, *newsize) == 0);
 
-       if (zopt_verbose >= 6) {
+       if (ztest_opts.zo_verbose >= 6) {
                (void) printf("%s grew from %lu to %lu bytes\n",
                    vd->vdev_path, (ulong_t)fsize, (ulong_t)*newsize);
        }
@@ -2715,7 +2856,7 @@ online_vdev(vdev_t *vd, void *arg)
         * vdev_open fails is by checking the returned newstate.
         */
        if (error || newstate != VDEV_STATE_HEALTHY) {
-               if (zopt_verbose >= 5) {
+               if (ztest_opts.zo_verbose >= 5) {
                        (void) printf("Unable to expand vdev, state %llu, "
                            "error %d\n", (u_longlong_t)newstate, error);
                }
@@ -2730,7 +2871,7 @@ online_vdev(vdev_t *vd, void *arg)
         * trying to online it.
         */
        if (generation != spa->spa_config_generation) {
-               if (zopt_verbose >= 5) {
+               if (ztest_opts.zo_verbose >= 5) {
                        (void) printf("vdev configuration has changed, "
                            "guid %llu, state %llu, expected gen %llu, "
                            "got gen %llu\n",
@@ -2778,8 +2919,7 @@ vdev_walk_tree(vdev_t *vd, vdev_t *(*func)(vdev_t *, void *), void *arg)
 void
 ztest_vdev_LUN_growth(ztest_ds_t *zd, uint64_t id)
 {
-       ztest_shared_t *zs = ztest_shared;
-       spa_t *spa = zs->zs_spa;
+       spa_t *spa = ztest_spa;
        vdev_t *vd, *tvd;
        metaslab_class_t *mc;
        metaslab_group_t *mg;
@@ -2787,7 +2927,7 @@ ztest_vdev_LUN_growth(ztest_ds_t *zd, uint64_t id)
        uint64_t top;
        uint64_t old_class_space, new_class_space, old_ms_count, new_ms_count;
 
-       mutex_enter(&zs->zs_vdev_lock);
+       mutex_enter(&ztest_vdev_lock);
        spa_config_enter(spa, SCL_STATE, spa, RW_READER);
 
        top = ztest_random_vdev_top(spa, B_TRUE);
@@ -2813,16 +2953,16 @@ ztest_vdev_LUN_growth(ztest_ds_t *zd, uint64_t id)
         * original size, and it has a valid psize.
         */
        if (tvd->vdev_state != VDEV_STATE_HEALTHY ||
-           psize == 0 || psize >= 4 * zopt_vdev_size) {
+           psize == 0 || psize >= 4 * ztest_opts.zo_vdev_size) {
                spa_config_exit(spa, SCL_STATE, spa);
-               mutex_exit(&zs->zs_vdev_lock);
+               mutex_exit(&ztest_vdev_lock);
                return;
        }
        ASSERT(psize > 0);
        newsize = psize + psize / 8;
        ASSERT3U(newsize, >, psize);
 
-       if (zopt_verbose >= 6) {
+       if (ztest_opts.zo_verbose >= 6) {
                (void) printf("Expanding LUN %s from %lu to %lu\n",
                    vd->vdev_path, (ulong_t)psize, (ulong_t)newsize);
        }
@@ -2835,12 +2975,12 @@ ztest_vdev_LUN_growth(ztest_ds_t *zd, uint64_t id)
        if (vdev_walk_tree(tvd, grow_vdev, &newsize) != NULL ||
            vdev_walk_tree(tvd, online_vdev, NULL) != NULL ||
            tvd->vdev_state != VDEV_STATE_HEALTHY) {
-               if (zopt_verbose >= 5) {
+               if (ztest_opts.zo_verbose >= 5) {
                        (void) printf("Could not expand LUN because "
                            "the vdev configuration changed.\n");
                }
                spa_config_exit(spa, SCL_STATE, spa);
-               mutex_exit(&zs->zs_vdev_lock);
+               mutex_exit(&ztest_vdev_lock);
                return;
        }
 
@@ -2869,12 +3009,12 @@ ztest_vdev_LUN_growth(ztest_ds_t *zd, uint64_t id)
        new_class_space = metaslab_class_get_space(mc);
 
        if (tvd->vdev_mg != mg || mg->mg_class != mc) {
-               if (zopt_verbose >= 5) {
+               if (ztest_opts.zo_verbose >= 5) {
                        (void) printf("Could not verify LUN expansion due to "
                            "intervening vdev offline or remove.\n");
                }
                spa_config_exit(spa, SCL_STATE, spa);
-               mutex_exit(&zs->zs_vdev_lock);
+               mutex_exit(&ztest_vdev_lock);
                return;
        }
 
@@ -2892,7 +3032,7 @@ ztest_vdev_LUN_growth(ztest_ds_t *zd, uint64_t id)
                fatal(0, "LUN expansion failed: class_space %llu <= %llu\n",
                    old_class_space, new_class_space);
 
-       if (zopt_verbose >= 5) {
+       if (ztest_opts.zo_verbose >= 5) {
                char oldnumbuf[6], newnumbuf[6];
 
                nicenum(old_class_space, oldnumbuf);
@@ -2902,7 +3042,7 @@ ztest_vdev_LUN_growth(ztest_ds_t *zd, uint64_t id)
        }
 
        spa_config_exit(spa, SCL_STATE, spa);
-       mutex_exit(&zs->zs_vdev_lock);
+       mutex_exit(&ztest_vdev_lock);
 }
 
 /*
@@ -2929,7 +3069,7 @@ ztest_dataset_create(char *dsname)
        if (err || zilset < 80)
                return (err);
 
-       if (zopt_verbose >= 5)
+       if (ztest_opts.zo_verbose >= 5)
                (void) printf("Setting dataset %s to sync always\n", dsname);
        return (ztest_dsl_prop_set_uint64(dsname, ZFS_PROP_SYNC,
            ZFS_SYNC_ALWAYS, B_FALSE));
@@ -3002,7 +3142,6 @@ ztest_snapshot_destroy(char *osname, uint64_t id)
 void
 ztest_dmu_objset_create_destroy(ztest_ds_t *zd, uint64_t id)
 {
-       ztest_shared_t *zs = ztest_shared;
        ztest_ds_t *zdtmp;
        int iters;
        int error;
@@ -3014,10 +3153,10 @@ ztest_dmu_objset_create_destroy(ztest_ds_t *zd, uint64_t id)
        zdtmp = umem_alloc(sizeof (ztest_ds_t), UMEM_NOFAIL);
        name = umem_alloc(MAXNAMELEN, UMEM_NOFAIL);
 
-       (void) rw_enter(&zs->zs_name_lock, RW_READER);
+       (void) rw_enter(&ztest_name_lock, RW_READER);
 
        (void) snprintf(name, MAXNAMELEN, "%s/temp_%llu",
-           zs->zs_pool, (u_longlong_t)id);
+           ztest_opts.zo_pool, (u_longlong_t)id);
 
        /*
         * If this dataset exists from a previous run, process its replay log
@@ -3026,7 +3165,7 @@ ztest_dmu_objset_create_destroy(ztest_ds_t *zd, uint64_t id)
         */
        if (ztest_random(2) == 0 &&
            dmu_objset_own(name, DMU_OST_OTHER, B_FALSE, FTAG, &os) == 0) {
-               ztest_zd_init(zdtmp, os);
+               ztest_zd_init(zdtmp, NULL, os);
                zil_replay(os, zdtmp, ztest_replay_vector);
                ztest_zd_fini(zdtmp);
                dmu_objset_disown(os, FTAG);
@@ -3060,7 +3199,7 @@ ztest_dmu_objset_create_destroy(ztest_ds_t *zd, uint64_t id)
        VERIFY3U(0, ==,
            dmu_objset_own(name, DMU_OST_OTHER, B_FALSE, FTAG, &os));
 
-       ztest_zd_init(zdtmp, os);
+       ztest_zd_init(zdtmp, NULL, os);
 
        /*
         * Open the intent log for it.
@@ -3100,7 +3239,7 @@ ztest_dmu_objset_create_destroy(ztest_ds_t *zd, uint64_t id)
        dmu_objset_disown(os, FTAG);
        ztest_zd_fini(zdtmp);
 out:
-       (void) rw_exit(&zs->zs_name_lock);
+       (void) rw_exit(&ztest_name_lock);
 
        umem_free(name, MAXNAMELEN);
        umem_free(zdtmp, sizeof (ztest_ds_t));
@@ -3112,12 +3251,10 @@ out:
 void
 ztest_dmu_snapshot_create_destroy(ztest_ds_t *zd, uint64_t id)
 {
-       ztest_shared_t *zs = ztest_shared;
-
-       (void) rw_enter(&zs->zs_name_lock, RW_READER);
+       (void) rw_enter(&ztest_name_lock, RW_READER);
        (void) ztest_snapshot_destroy(zd->zd_name, id);
        (void) ztest_snapshot_create(zd->zd_name, id);
-       (void) rw_exit(&zs->zs_name_lock);
+       (void) rw_exit(&ztest_name_lock);
 }
 
 /*
@@ -3179,7 +3316,6 @@ ztest_dsl_dataset_cleanup(char *osname, uint64_t id)
 void
 ztest_dsl_dataset_promote_busy(ztest_ds_t *zd, uint64_t id)
 {
-       ztest_shared_t *zs = ztest_shared;
        objset_t *clone;
        dsl_dataset_t *ds;
        char *snap1name;
@@ -3196,7 +3332,7 @@ ztest_dsl_dataset_promote_busy(ztest_ds_t *zd, uint64_t id)
        clone2name = umem_alloc(MAXNAMELEN, UMEM_NOFAIL);
        snap3name  = umem_alloc(MAXNAMELEN, UMEM_NOFAIL);
 
-       (void) rw_enter(&zs->zs_name_lock, RW_READER);
+       (void) rw_enter(&ztest_name_lock, RW_READER);
 
        ztest_dsl_dataset_cleanup(osname, id);
 
@@ -3281,7 +3417,7 @@ ztest_dsl_dataset_promote_busy(ztest_ds_t *zd, uint64_t id)
 out:
        ztest_dsl_dataset_cleanup(osname, id);
 
-       (void) rw_exit(&zs->zs_name_lock);
+       (void) rw_exit(&ztest_name_lock);
 
        umem_free(snap1name, MAXNAMELEN);
        umem_free(clone1name, MAXNAMELEN);
@@ -3507,7 +3643,7 @@ ztest_dmu_read_write(ztest_ds_t *zd, uint64_t id)
        dmu_write(os, packobj, packoff, packsize, packbuf, tx);
 
        if (freeit) {
-               if (zopt_verbose >= 7) {
+               if (ztest_opts.zo_verbose >= 7) {
                        (void) printf("freeing offset %llx size %llx"
                            " txg %llx\n",
                            (u_longlong_t)bigoff,
@@ -3516,7 +3652,7 @@ ztest_dmu_read_write(ztest_ds_t *zd, uint64_t id)
                }
                VERIFY(0 == dmu_free_range(os, bigobj, bigoff, bigsize, tx));
        } else {
-               if (zopt_verbose >= 7) {
+               if (ztest_opts.zo_verbose >= 7) {
                        (void) printf("writing offset %llx size %llx"
                            " txg %llx\n",
                            (u_longlong_t)bigoff,
@@ -3766,7 +3902,7 @@ ztest_dmu_read_write_zcopy(ztest_ds_t *zd, uint64_t id)
                 * Now write them out.
                 */
                dmu_write(os, packobj, packoff, packsize, packbuf, tx);
-               if (zopt_verbose >= 7) {
+               if (ztest_opts.zo_verbose >= 7) {
                        (void) printf("writing offset %llx size %llx"
                            " txg %llx\n",
                            (u_longlong_t)bigoff,
@@ -4436,38 +4572,36 @@ ztest_dsl_prop_get_set(ztest_ds_t *zd, uint64_t id)
                ZFS_PROP_COPIES,
                ZFS_PROP_DEDUP
        };
-       ztest_shared_t *zs = ztest_shared;
        int p;
 
-       (void) rw_enter(&zs->zs_name_lock, RW_READER);
+       (void) rw_enter(&ztest_name_lock, RW_READER);
 
        for (p = 0; p < sizeof (proplist) / sizeof (proplist[0]); p++)
                (void) ztest_dsl_prop_set_uint64(zd->zd_name, proplist[p],
                    ztest_random_dsl_prop(proplist[p]), (int)ztest_random(2));
 
-       (void) rw_exit(&zs->zs_name_lock);
+       (void) rw_exit(&ztest_name_lock);
 }
 
 /* ARGSUSED */
 void
 ztest_spa_prop_get_set(ztest_ds_t *zd, uint64_t id)
 {
-       ztest_shared_t *zs = ztest_shared;
        nvlist_t *props = NULL;
 
-       (void) rw_enter(&zs->zs_name_lock, RW_READER);
+       (void) rw_enter(&ztest_name_lock, RW_READER);
 
-       (void) ztest_spa_prop_set_uint64(zs, ZPOOL_PROP_DEDUPDITTO,
+       (void) ztest_spa_prop_set_uint64(ZPOOL_PROP_DEDUPDITTO,
            ZIO_DEDUPDITTO_MIN + ztest_random(ZIO_DEDUPDITTO_MIN));
 
-       VERIFY3U(spa_prop_get(zs->zs_spa, &props), ==, 0);
+       VERIFY3U(spa_prop_get(ztest_spa, &props), ==, 0);
 
-       if (zopt_verbose >= 6)
+       if (ztest_opts.zo_verbose >= 6)
                dump_nvlist(props, 4);
 
        nvlist_free(props);
 
-       (void) rw_exit(&zs->zs_name_lock);
+       (void) rw_exit(&ztest_name_lock);
 }
 
 /*
@@ -4485,7 +4619,7 @@ ztest_dmu_snapshot_hold(ztest_ds_t *zd, uint64_t id)
        char tag[100];
        char osname[MAXNAMELEN];
 
-       (void) rw_enter(&ztest_shared->zs_name_lock, RW_READER);
+       (void) rw_enter(&ztest_name_lock, RW_READER);
 
        dmu_objset_name(os, osname);
 
@@ -4582,7 +4716,7 @@ ztest_dmu_snapshot_hold(ztest_ds_t *zd, uint64_t id)
        VERIFY(dmu_objset_hold(fullname, FTAG, &origin) == ENOENT);
 
 out:
-       (void) rw_exit(&ztest_shared->zs_name_lock);
+       (void) rw_exit(&ztest_name_lock);
 }
 
 /*
@@ -4593,7 +4727,7 @@ void
 ztest_fault_inject(ztest_ds_t *zd, uint64_t id)
 {
        ztest_shared_t *zs = ztest_shared;
-       spa_t *spa = zs->zs_spa;
+       spa_t *spa = ztest_spa;
        int fd;
        uint64_t offset;
        uint64_t leaves;
@@ -4613,11 +4747,11 @@ ztest_fault_inject(ztest_ds_t *zd, uint64_t id)
        path0 = umem_alloc(MAXPATHLEN, UMEM_NOFAIL);
        pathrand = umem_alloc(MAXPATHLEN, UMEM_NOFAIL);
 
-       mutex_enter(&zs->zs_vdev_lock);
+       mutex_enter(&ztest_vdev_lock);
        maxfaults = MAXFAULTS();
-       leaves = MAX(zs->zs_mirrors, 1) * zopt_raidz;
+       leaves = MAX(zs->zs_mirrors, 1) * ztest_opts.zo_raidz;
        mirror_save = zs->zs_mirrors;
-       mutex_exit(&zs->zs_vdev_lock);
+       mutex_exit(&ztest_vdev_lock);
 
        ASSERT(leaves >= 1);
 
@@ -4640,9 +4774,11 @@ ztest_fault_inject(ztest_ds_t *zd, uint64_t id)
                 * and we'll write random garbage to the randomly chosen leaf.
                 */
                (void) snprintf(path0, MAXPATHLEN, ztest_dev_template,
-                   zopt_dir, zopt_pool, top * leaves + zs->zs_splits);
+                   ztest_opts.zo_dir, ztest_opts.zo_pool,
+                   top * leaves + zs->zs_splits);
                (void) snprintf(pathrand, MAXPATHLEN, ztest_dev_template,
-                   zopt_dir, zopt_pool, top * leaves + leaf);
+                   ztest_opts.zo_dir, ztest_opts.zo_pool,
+                   top * leaves + leaf);
 
                vd0 = vdev_lookup_by_path(spa->spa_root_vdev, path0);
                if (vd0 != NULL && vd0->vdev_top->vdev_islog)
@@ -4711,13 +4847,13 @@ ztest_fault_inject(ztest_ds_t *zd, uint64_t id)
                         * leaving the dataset in an inconsistent state.
                         */
                        if (islog)
-                               (void) rw_enter(&ztest_shared->zs_name_lock,
+                               (void) rw_enter(&ztest_name_lock,
                                    RW_WRITER);
 
                        VERIFY(vdev_offline(spa, guid0, flags) != EBUSY);
 
                        if (islog)
-                               (void) rw_exit(&ztest_shared->zs_name_lock);
+                               (void) rw_exit(&ztest_name_lock);
                } else {
                        (void) vdev_online(spa, guid0, 0, NULL);
                }
@@ -4744,9 +4880,9 @@ ztest_fault_inject(ztest_ds_t *zd, uint64_t id)
                if (offset >= fsize)
                        continue;
 
-               mutex_enter(&zs->zs_vdev_lock);
+               mutex_enter(&ztest_vdev_lock);
                if (mirror_save != zs->zs_mirrors) {
-                       mutex_exit(&zs->zs_vdev_lock);
+                       mutex_exit(&ztest_vdev_lock);
                        (void) close(fd);
                        goto out;
                }
@@ -4755,9 +4891,9 @@ ztest_fault_inject(ztest_ds_t *zd, uint64_t id)
                        fatal(1, "can't inject bad word at 0x%llx in %s",
                            offset, pathrand);
 
-               mutex_exit(&zs->zs_vdev_lock);
+               mutex_exit(&ztest_vdev_lock);
 
-               if (zopt_verbose >= 7)
+               if (ztest_opts.zo_verbose >= 7)
                        (void) printf("injected bad word into %s,"
                            " offset 0x%llx\n", pathrand, (u_longlong_t)offset);
        }
@@ -4775,7 +4911,7 @@ void
 ztest_ddt_repair(ztest_ds_t *zd, uint64_t id)
 {
        ztest_shared_t *zs = ztest_shared;
-       spa_t *spa = zs->zs_spa;
+       spa_t *spa = ztest_spa;
        objset_t *os = zd->zd_os;
        ztest_od_t *od;
        uint64_t object, blocksize, txg, pattern, psize;
@@ -4802,13 +4938,13 @@ ztest_ddt_repair(ztest_ds_t *zd, uint64_t id)
         * Take the name lock as writer to prevent anyone else from changing
         * the pool and dataset properies we need to maintain during this test.
         */
-       (void) rw_enter(&zs->zs_name_lock, RW_WRITER);
+       (void) rw_enter(&ztest_name_lock, RW_WRITER);
 
        if (ztest_dsl_prop_set_uint64(zd->zd_name, ZFS_PROP_DEDUP, checksum,
            B_FALSE) != 0 ||
            ztest_dsl_prop_set_uint64(zd->zd_name, ZFS_PROP_COPIES, 1,
            B_FALSE) != 0) {
-               (void) rw_exit(&zs->zs_name_lock);
+               (void) rw_exit(&ztest_name_lock);
                umem_free(od, sizeof(ztest_od_t));
                return;
        }
@@ -4823,7 +4959,7 @@ ztest_ddt_repair(ztest_ds_t *zd, uint64_t id)
        dmu_tx_hold_write(tx, object, 0, copies * blocksize);
        txg = ztest_tx_assign(tx, TXG_WAIT, FTAG);
        if (txg == 0) {
-               (void) rw_exit(&zs->zs_name_lock);
+               (void) rw_exit(&ztest_name_lock);
                umem_free(od, sizeof(ztest_od_t));
                return;
        }
@@ -4868,7 +5004,7 @@ ztest_ddt_repair(ztest_ds_t *zd, uint64_t id)
 
        zio_buf_free(buf, psize);
 
-       (void) rw_exit(&zs->zs_name_lock);
+       (void) rw_exit(&ztest_name_lock);
        umem_free(od, sizeof(ztest_od_t));
 }
 
@@ -4879,8 +5015,7 @@ ztest_ddt_repair(ztest_ds_t *zd, uint64_t id)
 void
 ztest_scrub(ztest_ds_t *zd, uint64_t id)
 {
-       ztest_shared_t *zs = ztest_shared;
-       spa_t *spa = zs->zs_spa;
+       spa_t *spa = ztest_spa;
 
        (void) spa_scan(spa, POOL_SCAN_SCRUB);
        (void) poll(NULL, 0, 100); /* wait a moment, then force a restart */
@@ -4894,8 +5029,7 @@ ztest_scrub(ztest_ds_t *zd, uint64_t id)
 void
 ztest_reguid(ztest_ds_t *zd, uint64_t id)
 {
-       ztest_shared_t *zs = ztest_shared;
-       spa_t *spa = zs->zs_spa;
+       spa_t *spa = ztest_spa;
        uint64_t orig, load;
 
        orig = spa_guid(spa);
@@ -4903,7 +5037,7 @@ ztest_reguid(ztest_ds_t *zd, uint64_t id)
        if (spa_change_guid(spa) != 0)
                return;
 
-       if (zopt_verbose >= 3) {
+       if (ztest_opts.zo_verbose >= 3) {
                (void) printf("Changed guid old %llu -> %llu\n",
                    (u_longlong_t)orig, (u_longlong_t)spa_guid(spa));
        }
@@ -4919,13 +5053,12 @@ ztest_reguid(ztest_ds_t *zd, uint64_t id)
 void
 ztest_spa_rename(ztest_ds_t *zd, uint64_t id)
 {
-       ztest_shared_t *zs = ztest_shared;
        char *oldname, *newname;
        spa_t *spa;
 
-       (void) rw_enter(&zs->zs_name_lock, RW_WRITER);
+       (void) rw_enter(&ztest_name_lock, RW_WRITER);
 
-       oldname = zs->zs_pool;
+       oldname = ztest_opts.zo_pool;
        newname = umem_alloc(strlen(oldname) + 5, UMEM_NOFAIL);
        (void) strcpy(newname, oldname);
        (void) strcat(newname, "_tmp");
@@ -4945,7 +5078,7 @@ ztest_spa_rename(ztest_ds_t *zd, uint64_t id)
         */
        VERIFY3U(0, ==, spa_open(newname, &spa, FTAG));
 
-       ASSERT(spa == zs->zs_spa);
+       ASSERT(spa == ztest_spa);
        spa_close(spa, FTAG);
 
        /*
@@ -4958,12 +5091,12 @@ ztest_spa_rename(ztest_ds_t *zd, uint64_t id)
         */
        VERIFY3U(0, ==, spa_open(oldname, &spa, FTAG));
 
-       ASSERT(spa == zs->zs_spa);
+       ASSERT(spa == ztest_spa);
        spa_close(spa, FTAG);
 
        umem_free(newname, strlen(newname) + 1);
 
-       (void) rw_exit(&zs->zs_name_lock);
+       (void) rw_exit(&ztest_name_lock);
 }
 
 /*
@@ -4995,18 +5128,18 @@ ztest_run_zdb(char *pool)
        (void) sprintf(zdb,
            "%s -bcc%s%s -U %s %s",
            bin,
-           zopt_verbose >= 3 ? "s" : "",
-           zopt_verbose >= 4 ? "v" : "",
+           ztest_opts.zo_verbose >= 3 ? "s" : "",
+           ztest_opts.zo_verbose >= 4 ? "v" : "",
            spa_config_path,
            pool);
 
-       if (zopt_verbose >= 5)
+       if (ztest_opts.zo_verbose >= 5)
                (void) printf("Executing %s\n", strstr(zdb, "zdb "));
 
        fp = popen(zdb, "r");
 
        while (fgets(zbuf, 1024, fp) != NULL)
-               if (zopt_verbose >= 3)
+               if (ztest_opts.zo_verbose >= 3)
                        (void) printf("%s", zbuf);
 
        status = pclose(fp);
@@ -5030,12 +5163,12 @@ ztest_walk_pool_directory(char *header)
 {
        spa_t *spa = NULL;
 
-       if (zopt_verbose >= 6)
+       if (ztest_opts.zo_verbose >= 6)
                (void) printf("%s\n", header);
 
        mutex_enter(&spa_namespace_lock);
        while ((spa = spa_next(spa)) != NULL)
-               if (zopt_verbose >= 6)
+               if (ztest_opts.zo_verbose >= 6)
                        (void) printf("\t%s\n", spa_name(spa));
        mutex_exit(&spa_namespace_lock);
 }
@@ -5047,7 +5180,7 @@ ztest_spa_import_export(char *oldname, char *newname)
        uint64_t pool_guid;
        spa_t *spa;
 
-       if (zopt_verbose >= 4) {
+       if (ztest_opts.zo_verbose >= 4) {
                (void) printf("import/export: old = %s, new = %s\n",
                    oldname, newname);
        }
@@ -5122,7 +5255,7 @@ ztest_spa_import_export(char *oldname, char *newname)
 static void
 ztest_resume(spa_t *spa)
 {
-       if (spa_suspended(spa) && zopt_verbose >= 6)
+       if (spa_suspended(spa) && ztest_opts.zo_verbose >= 6)
                (void) printf("resuming from suspended state\n");
        spa_vdev_state_enter(spa, SCL_NONE);
        vdev_clear(spa, NULL);
@@ -5155,10 +5288,10 @@ ztest_deadman_alarm(int sig)
 }
 
 static void
-ztest_execute(ztest_info_t *zi, uint64_t id)
+ztest_execute(int test, ztest_info_t *zi, uint64_t id)
 {
-       ztest_shared_t *zs = ztest_shared;
-       ztest_ds_t *zd = &zs->zs_zd[id % zopt_datasets];
+       ztest_ds_t *zd = &ztest_ds[id % ztest_opts.zo_datasets];
+       ztest_shared_callstate_t *zc = ZTEST_GET_SHARED_CALLSTATE(test);
        hrtime_t functime = gethrtime();
        int i;
 
@@ -5167,10 +5300,10 @@ ztest_execute(ztest_info_t *zi, uint64_t id)
 
        functime = gethrtime() - functime;
 
-       atomic_add_64(&zi->zi_call_count, 1);
-       atomic_add_64(&zi->zi_call_time, functime);
+       atomic_add_64(&zc->zc_count, 1);
+       atomic_add_64(&zc->zc_time, functime);
 
-       if (zopt_verbose >= 4) {
+       if (ztest_opts.zo_verbose >= 4) {
                Dl_info dli;
                (void) dladdr((void *)zi->zi_func, &dli);
                (void) printf("%6.2f sec in %s\n",
@@ -5181,11 +5314,13 @@ ztest_execute(ztest_info_t *zi, uint64_t id)
 static void *
 ztest_thread(void *arg)
 {
+       int rand;
        uint64_t id = (uintptr_t)arg;
        ztest_shared_t *zs = ztest_shared;
        uint64_t call_next;
        hrtime_t now;
        ztest_info_t *zi;
+       ztest_shared_callstate_t *zc;
 
        while ((now = gethrtime()) < zs->zs_thread_stop) {
                /*
@@ -5203,13 +5338,16 @@ ztest_thread(void *arg)
                /*
                 * Pick a random function to execute.
                 */
-               zi = &zs->zs_info[ztest_random(ZTEST_FUNCS)];
-               call_next = zi->zi_call_next;
+               rand = ztest_random(ZTEST_FUNCS);
+               zi = &ztest_info[rand];
+               zc = ZTEST_GET_SHARED_CALLSTATE(rand);
+               call_next = zc->zc_next;
 
                if (now >= call_next &&
-                   atomic_cas_64(&zi->zi_call_next, call_next, call_next +
-                   ztest_random(2 * zi->zi_interval[0] + 1)) == call_next)
-                       ztest_execute(zi, id);
+                   atomic_cas_64(&zc->zc_next, call_next, call_next +
+                   ztest_random(2 * zi->zi_interval[0] + 1)) == call_next) {
+                       ztest_execute(rand, zi, id);
+               }
        }
 
        thread_exit();
@@ -5224,14 +5362,14 @@ ztest_dataset_name(char *dsname, char *pool, int d)
 }
 
 static void
-ztest_dataset_destroy(ztest_shared_t *zs, int d)
+ztest_dataset_destroy(int d)
 {
        char name[MAXNAMELEN];
        int t;
 
-       ztest_dataset_name(name, zs->zs_pool, d);
+       ztest_dataset_name(name, ztest_opts.zo_pool, d);
 
-       if (zopt_verbose >= 3)
+       if (ztest_opts.zo_verbose >= 3)
                (void) printf("Destroying %s to free up space\n", name);
 
        /*
@@ -5239,7 +5377,8 @@ ztest_dataset_destroy(ztest_shared_t *zs, int d)
         * ztest thread t operates on dataset (t % zopt_datasets),
         * so there may be more than one thing to clean up.
         */
-       for (t = d; t < zopt_threads; t += zopt_datasets)
+       for (t = d; t < ztest_opts.zo_threads;
+           t += ztest_opts.zo_datasets)
                ztest_dsl_dataset_cleanup(name, t);
 
        (void) dmu_objset_find(name, ztest_objset_destroy_cb, NULL,
@@ -5268,31 +5407,31 @@ ztest_dataset_dirobj_verify(ztest_ds_t *zd)
 }
 
 static int
-ztest_dataset_open(ztest_shared_t *zs, int d)
+ztest_dataset_open(int d)
 {
-       ztest_ds_t *zd = &zs->zs_zd[d];
-       uint64_t committed_seq = zd->zd_seq;
+       ztest_ds_t *zd = &ztest_ds[d];
+       uint64_t committed_seq = ZTEST_GET_SHARED_DS(d)->zd_seq;
        objset_t *os;
        zilog_t *zilog;
        char name[MAXNAMELEN];
        int error;
 
-       ztest_dataset_name(name, zs->zs_pool, d);
+       ztest_dataset_name(name, ztest_opts.zo_pool, d);
 
-       (void) rw_enter(&zs->zs_name_lock, RW_READER);
+       (void) rw_enter(&ztest_name_lock, RW_READER);
 
        error = ztest_dataset_create(name);
        if (error == ENOSPC) {
-               (void) rw_exit(&zs->zs_name_lock);
+               (void) rw_exit(&ztest_name_lock);
                ztest_record_enospc(FTAG);
                return (error);
        }
        ASSERT(error == 0 || error == EEXIST);
 
        VERIFY3U(dmu_objset_hold(name, zd, &os), ==, 0);
-       (void) rw_exit(&zs->zs_name_lock);
+       (void) rw_exit(&ztest_name_lock);
 
-       ztest_zd_init(zd, os);
+       ztest_zd_init(zd, ZTEST_GET_SHARED_DS(d), os);
 
        zilog = zd->zd_zilog;
 
@@ -5307,7 +5446,7 @@ ztest_dataset_open(ztest_shared_t *zs, int d)
 
        ztest_dataset_dirobj_verify(zd);
 
-       if (zopt_verbose >= 6)
+       if (ztest_opts.zo_verbose >= 6)
                (void) printf("%s replay %llu blocks, %llu records, seq %llu\n",
                    zd->zd_name,
                    (u_longlong_t)zilog->zl_parse_blk_count,
@@ -5325,9 +5464,9 @@ ztest_dataset_open(ztest_shared_t *zs, int d)
 }
 
 static void
-ztest_dataset_close(ztest_shared_t *zs, int d)
+ztest_dataset_close(int d)
 {
-       ztest_ds_t *zd = &zs->zs_zd[d];
+       ztest_ds_t *zd = &ztest_ds[d];
 
        zil_close(zd->zd_zilog);
        dmu_objset_rele(zd->zd_os, zd);
@@ -5354,15 +5493,18 @@ ztest_run(ztest_shared_t *zs)
        /*
         * Initialize parent/child shared state.
         */
-       mutex_init(&zs->zs_vdev_lock, NULL, MUTEX_DEFAULT, NULL);
-       rw_init(&zs->zs_name_lock, NULL, RW_DEFAULT, NULL);
+       mutex_init(&ztest_vdev_lock, NULL, MUTEX_DEFAULT, NULL);
+       rw_init(&ztest_name_lock, NULL, RW_DEFAULT, NULL);
 
        zs->zs_thread_start = gethrtime();
-       zs->zs_thread_stop = zs->zs_thread_start + zopt_passtime * NANOSEC;
+       zs->zs_thread_stop =
+           zs->zs_thread_start + ztest_opts.zo_passtime * NANOSEC;
        zs->zs_thread_stop = MIN(zs->zs_thread_stop, zs->zs_proc_stop);
        zs->zs_thread_kill = zs->zs_thread_stop;
-       if (ztest_random(100) < zopt_killrate)
-               zs->zs_thread_kill -= ztest_random(zopt_passtime * NANOSEC);
+       if (ztest_random(100) < ztest_opts.zo_killrate) {
+               zs->zs_thread_kill -=
+                   ztest_random(ztest_opts.zo_passtime * NANOSEC);
+       }
 
        mutex_init(&zcl.zcl_callbacks_lock, NULL, MUTEX_DEFAULT, NULL);
 
@@ -5373,11 +5515,11 @@ ztest_run(ztest_shared_t *zs)
         * Open our pool.
         */
        kernel_init(FREAD | FWRITE);
-       VERIFY(spa_open(zs->zs_pool, &spa, FTAG) == 0);
+       VERIFY(spa_open(ztest_opts.zo_pool, &spa, FTAG) == 0);
        spa->spa_debug = B_TRUE;
-       zs->zs_spa = spa;
+       ztest_spa = spa;
 
-       VERIFY3U(0, ==, dmu_objset_hold(zs->zs_pool, FTAG, &os));
+       VERIFY3U(0, ==, dmu_objset_hold(ztest_opts.zo_pool, FTAG, &os));
        zs->zs_guid = dmu_objset_fsid_guid(os);
        dmu_objset_rele(os, FTAG);
 
@@ -5425,23 +5567,25 @@ ztest_run(ztest_shared_t *zs)
         * If we got any ENOSPC errors on the previous run, destroy something.
         */
        if (zs->zs_enospc_count != 0) {
-               int d = ztest_random(zopt_datasets);
-               ztest_dataset_destroy(zs, d);
+               int d = ztest_random(ztest_opts.zo_datasets);
+               ztest_dataset_destroy(d);
        }
        zs->zs_enospc_count = 0;
 
-       tid = umem_zalloc(zopt_threads * sizeof (kt_did_t), UMEM_NOFAIL);
+       tid = umem_zalloc(ztest_opts.zo_threads * sizeof (kt_did_t),
+           UMEM_NOFAIL);
 
-       if (zopt_verbose >= 4)
+       if (ztest_opts.zo_verbose >= 4)
                (void) printf("starting main threads...\n");
 
        /*
         * Kick off all the tests that run in parallel.
         */
-       for (t = 0; t < zopt_threads; t++) {
+       for (t = 0; t < ztest_opts.zo_threads; t++) {
                kthread_t *thread;
 
-               if (t < zopt_datasets && ztest_dataset_open(zs, t) != 0)
+               if (t < ztest_opts.zo_datasets &&
+                   ztest_dataset_open(t) != 0)
                        return;
 
                VERIFY3P(thread = zk_thread_create(NULL, 0,
@@ -5455,10 +5599,10 @@ ztest_run(ztest_shared_t *zs)
         * Wait for all of the tests to complete.  We go in reverse order
         * so we don't close datasets while threads are still using them.
         */
-       for (t = zopt_threads - 1; t >= 0; t--) {
+       for (t = ztest_opts.zo_threads - 1; t >= 0; t--) {
                thread_join(tid[t]);
-               if (t < zopt_datasets)
-                       ztest_dataset_close(zs, t);
+               if (t < ztest_opts.zo_datasets)
+                       ztest_dataset_close(t);
        }
 
        txg_wait_synced(spa_get_dsl(spa), 0);
@@ -5466,7 +5610,7 @@ ztest_run(ztest_shared_t *zs)
        zs->zs_alloc = metaslab_class_get_alloc(spa_normal_class(spa));
        zs->zs_space = metaslab_class_get_space(spa_normal_class(spa));
 
-       umem_free(tid, zopt_threads * sizeof (kt_did_t));
+       umem_free(tid, ztest_opts.zo_threads * sizeof (kt_did_t));
 
        /* Kill the resume thread */
        ztest_exiting = B_TRUE;
@@ -5491,7 +5635,7 @@ ztest_run(ztest_shared_t *zs)
         */
        mutex_enter(&spa_namespace_lock);
        for (spa = spa_next(NULL); spa != NULL; spa = spa_next(spa))
-               if (zopt_verbose > 3)
+               if (ztest_opts.zo_verbose > 3)
                        (void) printf("spa_next: found %s\n", spa_name(spa));
        mutex_exit(&spa_namespace_lock);
 
@@ -5501,32 +5645,33 @@ ztest_run(ztest_shared_t *zs)
         */
        if (ztest_random(2) == 0) {
                char name[MAXNAMELEN];
-               (void) snprintf(name, MAXNAMELEN, "%s_import", zs->zs_pool);
-               ztest_spa_import_export(zs->zs_pool, name);
-               ztest_spa_import_export(name, zs->zs_pool);
+               (void) snprintf(name, MAXNAMELEN, "%s_import",
+                   ztest_opts.zo_pool);
+               ztest_spa_import_export(ztest_opts.zo_pool, name);
+               ztest_spa_import_export(name, ztest_opts.zo_pool);
        }
 
        kernel_fini();
 
        list_destroy(&zcl.zcl_callbacks);
        mutex_destroy(&zcl.zcl_callbacks_lock);
-       rw_destroy(&zs->zs_name_lock);
-       mutex_destroy(&zs->zs_vdev_lock);
+       rw_destroy(&ztest_name_lock);
+       mutex_destroy(&ztest_vdev_lock);
 }
 
 static void
-ztest_freeze(ztest_shared_t *zs)
+ztest_freeze(void)
 {
-       ztest_ds_t *zd = &zs->zs_zd[0];
+       ztest_ds_t *zd = &ztest_ds[0];
        spa_t *spa;
        int numloops = 0;
 
-       if (zopt_verbose >= 3)
+       if (ztest_opts.zo_verbose >= 3)
                (void) printf("testing spa_freeze()...\n");
 
        kernel_init(FREAD | FWRITE);
-       VERIFY3U(0, ==, spa_open(zs->zs_pool, &spa, FTAG));
-       VERIFY3U(0, ==, ztest_dataset_open(zs, 0));
+       VERIFY3U(0, ==, spa_open(ztest_opts.zo_pool, &spa, FTAG));
+       VERIFY3U(0, ==, ztest_dataset_open(0));
 
        /*
         * Force the first log block to be transactionally allocated.
@@ -5553,7 +5698,8 @@ ztest_freeze(ztest_shared_t *zs)
         * to increase well beyond the last synced value in the uberblock.
         * The ZIL should be OK with that.
         */
-       while (ztest_random(10) != 0 && numloops++ < zopt_maxloops) {
+       while (ztest_random(10) != 0 &&
+           numloops++ < ztest_opts.zo_maxloops) {
                ztest_dmu_write_parallel(zd, 0);
                ztest_dmu_object_alloc_free(zd, 0);
                txg_wait_synced(spa_get_dsl(spa), 0);
@@ -5568,7 +5714,7 @@ ztest_freeze(ztest_shared_t *zs)
        /*
         * Close our dataset and close the pool.
         */
-       ztest_dataset_close(zs, 0);
+       ztest_dataset_close(0);
        spa_close(spa, FTAG);
        kernel_fini();
 
@@ -5576,9 +5722,9 @@ ztest_freeze(ztest_shared_t *zs)
         * Open and close the pool and dataset to induce log replay.
         */
        kernel_init(FREAD | FWRITE);
-       VERIFY3U(0, ==, spa_open(zs->zs_pool, &spa, FTAG));
-       VERIFY3U(0, ==, ztest_dataset_open(zs, 0));
-       ztest_dataset_close(zs, 0);
+       VERIFY3U(0, ==, spa_open(ztest_opts.zo_pool, &spa, FTAG));
+       VERIFY3U(0, ==, ztest_dataset_open(0));
+       ztest_dataset_close(0);
        spa_close(spa, FTAG);
        kernel_fini();
 }
@@ -5619,9 +5765,6 @@ make_random_props(void)
        VERIFY(nvlist_alloc(&props, NV_UNIQUE_NAME, 0) == 0);
        VERIFY(nvlist_add_uint64(props, "autoreplace", 1) == 0);
 
-       (void) printf("props:\n");
-       dump_nvlist(props, 4);
-
        return (props);
 }
 
@@ -5635,38 +5778,200 @@ ztest_init(ztest_shared_t *zs)
        spa_t *spa;
        nvlist_t *nvroot, *props;
 
-       mutex_init(&zs->zs_vdev_lock, NULL, MUTEX_DEFAULT, NULL);
-       rw_init(&zs->zs_name_lock, NULL, RW_DEFAULT, NULL);
+       mutex_init(&ztest_vdev_lock, NULL, MUTEX_DEFAULT, NULL);
+       rw_init(&ztest_name_lock, NULL, RW_DEFAULT, NULL);
 
        kernel_init(FREAD | FWRITE);
 
        /*
         * Create the storage pool.
         */
-       (void) spa_destroy(zs->zs_pool);
+       (void) spa_destroy(ztest_opts.zo_pool);
        ztest_shared->zs_vdev_next_leaf = 0;
        zs->zs_splits = 0;
-       zs->zs_mirrors = zopt_mirrors;
-       nvroot = make_vdev_root(NULL, NULL, zopt_vdev_size, 0,
-           0, zopt_raidz, zs->zs_mirrors, 1);
+       zs->zs_mirrors = ztest_opts.zo_mirrors;
+       nvroot = make_vdev_root(NULL, NULL, ztest_opts.zo_vdev_size, 0,
+           0, ztest_opts.zo_raidz, zs->zs_mirrors, 1);
        props = make_random_props();
-       VERIFY3U(0, ==, spa_create(zs->zs_pool, nvroot, props, NULL, NULL));
+       VERIFY3U(0, ==, spa_create(ztest_opts.zo_pool, nvroot, props,
+           NULL, NULL));
        nvlist_free(nvroot);
 
-       VERIFY3U(0, ==, spa_open(zs->zs_pool, &spa, FTAG));
-       metaslab_sz = 1ULL << spa->spa_root_vdev->vdev_child[0]->vdev_ms_shift;
+       VERIFY3U(0, ==, spa_open(ztest_opts.zo_pool, &spa, FTAG));
+       zs->zs_metaslab_sz =
+           1ULL << spa->spa_root_vdev->vdev_child[0]->vdev_ms_shift;
        spa_close(spa, FTAG);
 
        kernel_fini();
 
-       ztest_run_zdb(zs->zs_pool);
+       ztest_run_zdb(ztest_opts.zo_pool);
+
+       ztest_freeze();
+
+       ztest_run_zdb(ztest_opts.zo_pool);
+
+       rw_destroy(&ztest_name_lock);
+       mutex_destroy(&ztest_vdev_lock);
+}
+
+static void
+setup_fds(void)
+{
+       int fd;
+
+       char *tmp = tempnam(NULL, NULL);
+       fd = open(tmp, O_RDWR | O_CREAT, 0700);
+       ASSERT3S(fd, >=, 0);
+       VERIFY3S(ftruncate(fd, sizeof (ztest_shared_hdr_t)), ==, 0);
+       if (fd != ZTEST_FD_DATA) {
+               VERIFY3S(dup2(fd, ZTEST_FD_DATA), ==, ZTEST_FD_DATA);
+               close(fd);
+       }
+       (void) unlink(tmp);
+       free(tmp);
+
+       fd = open("/dev/urandom", O_RDONLY);
+       ASSERT3S(fd, >=, 0);
+       if (fd != ZTEST_FD_RAND) {
+               VERIFY3S(dup2(fd, ZTEST_FD_RAND), ==, ZTEST_FD_RAND);
+               close(fd);
+       }
+}
+
+static void
+setup_hdr(void)
+{
+       ztest_shared_hdr_t *hdr;
+
+       hdr = (void *)mmap(0, P2ROUNDUP(sizeof (*hdr), getpagesize()),
+           PROT_READ | PROT_WRITE, MAP_SHARED, ZTEST_FD_DATA, 0);
+       ASSERT(hdr != MAP_FAILED);
+
+       hdr->zh_hdr_size = sizeof (ztest_shared_hdr_t);
+       hdr->zh_opts_size = sizeof (ztest_shared_opts_t);
+       hdr->zh_size = sizeof (ztest_shared_t);
+       hdr->zh_stats_size = sizeof (ztest_shared_callstate_t);
+       hdr->zh_stats_count = ZTEST_FUNCS;
+       hdr->zh_ds_size = sizeof (ztest_shared_ds_t);
+       hdr->zh_ds_count = ztest_opts.zo_datasets;
+
+       (void) munmap((caddr_t)hdr, P2ROUNDUP(sizeof (*hdr), getpagesize()));
+}
+
+static void
+setup_data(void)
+{
+       int size, offset;
+       ztest_shared_hdr_t *hdr;
+       uint8_t *buf;
+
+       hdr = (void *)mmap(0, P2ROUNDUP(sizeof (*hdr), getpagesize()),
+           PROT_READ, MAP_SHARED, ZTEST_FD_DATA, 0);
+       ASSERT(hdr != MAP_FAILED);
+
+       size = hdr->zh_hdr_size;
+       size += hdr->zh_opts_size;
+       size += hdr->zh_size;
+       size += hdr->zh_stats_size * hdr->zh_stats_count;
+       size += hdr->zh_ds_size * hdr->zh_ds_count;
+
+       (void) munmap((caddr_t)hdr, P2ROUNDUP(sizeof (*hdr), getpagesize()));
+       hdr = ztest_shared_hdr = (void *)mmap(0, P2ROUNDUP(size, getpagesize()),
+           PROT_READ | PROT_WRITE, MAP_SHARED, ZTEST_FD_DATA, 0);
+       ASSERT(hdr != MAP_FAILED);
+       buf = (uint8_t *)hdr;
+
+       offset = hdr->zh_hdr_size;
+       ztest_shared_opts = (void *)&buf[offset];
+       offset += hdr->zh_opts_size;
+       ztest_shared = (void *)&buf[offset];
+       offset += hdr->zh_size;
+       ztest_shared_callstate = (void *)&buf[offset];
+       offset += hdr->zh_stats_size * hdr->zh_stats_count;
+       ztest_shared_ds = (void *)&buf[offset];
+}
+
+static boolean_t
+exec_child(char *cmd, char *libpath, boolean_t ignorekill, int *statusp)
+{
+       pid_t pid;
+       int status;
+       char cmdbuf[MAXPATHLEN];
+
+       pid = fork();
+
+       if (cmd == NULL) {
+               (void) strlcpy(cmdbuf, getexecname(), sizeof (cmdbuf));
+               cmd = cmdbuf;
+       }
+
+       if (pid == -1)
+               fatal(1, "fork failed");
+
+       if (pid == 0) { /* child */
+               char *emptyargv[2] = { cmd, NULL };
+
+               struct rlimit rl = { 1024, 1024 };
+               (void) setrlimit(RLIMIT_NOFILE, &rl);
+               (void) enable_extended_FILE_stdio(-1, -1);
+               if (libpath != NULL)
+                       VERIFY(0 == setenv("LD_LIBRARY_PATH", libpath, 1));
+               (void) execv(cmd, emptyargv);
+               ztest_dump_core = B_FALSE;
+               fatal(B_TRUE, "exec failed: %s", cmd);
+       }
+
+       while (waitpid(pid, &status, 0) != pid)
+               continue;
+       if (statusp != NULL)
+               *statusp = status;
+
+       if (WIFEXITED(status)) {
+               if (WEXITSTATUS(status) != 0) {
+                       (void) fprintf(stderr, "child exited with code %d\n",
+                           WEXITSTATUS(status));
+                       exit(2);
+               }
+               return (B_FALSE);
+       } else if (WIFSIGNALED(status)) {
+               if (!ignorekill || WTERMSIG(status) != SIGKILL) {
+                       (void) fprintf(stderr, "child died with signal %d\n",
+                           WTERMSIG(status));
+                       exit(3);
+               }
+               return (B_TRUE);
+       } else {
+               (void) fprintf(stderr, "something strange happened to child\n");
+               exit(4);
+               /* NOTREACHED */
+       }
+}
+
+static void
+ztest_run_init(void)
+{
+       int i;
 
-       ztest_freeze(zs);
+       ztest_shared_t *zs = ztest_shared;
 
-       ztest_run_zdb(zs->zs_pool);
+       ASSERT(ztest_opts.zo_init != 0);
 
-       (void) rw_destroy(&zs->zs_name_lock);
-       (void) mutex_destroy(&zs->zs_vdev_lock);
+       /*
+        * Blow away any existing copy of zpool.cache
+        */
+       (void) remove(spa_config_path);
+
+       /*
+        * Create and initialize our storage pool.
+        */
+       for (i = 1; i <= ztest_opts.zo_init; i++) {
+               bzero(zs, sizeof (ztest_shared_t));
+               if (ztest_opts.zo_verbose >= 3 &&
+                   ztest_opts.zo_init != 1) {
+                       (void) printf("ztest_init(), pass %d\n", i);
+               }
+               ztest_init(zs);
+       }
 }
 
 int
@@ -5674,66 +5979,94 @@ main(int argc, char **argv)
 {
        int kills = 0;
        int iters = 0;
+       int older = 0;
+       int newer = 0;
        ztest_shared_t *zs;
-       size_t shared_size;
        ztest_info_t *zi;
+       ztest_shared_callstate_t *zc;
        char timebuf[100];
        char numbuf[6];
        spa_t *spa;
-       int i, f;
+       char cmd[MAXNAMELEN];
+       boolean_t hasalt;
+       int f;
+       boolean_t ischild = (0 == lseek(ZTEST_FD_DATA, 0, SEEK_CUR));
+
+       ASSERT(ischild || errno == EBADF || errno == ESPIPE);
 
        (void) setvbuf(stdout, NULL, _IOLBF, 0);
 
-       ztest_random_fd = open("/dev/urandom", O_RDONLY);
+       if (!ischild) {
+               dprintf_setup(&argc, argv);
+               process_options(argc, argv);
 
-       dprintf_setup(&argc, argv);
-       process_options(argc, argv);
+               setup_fds();
+               setup_hdr();
+               setup_data();
+               bcopy(&ztest_opts, ztest_shared_opts,
+                   sizeof (*ztest_shared_opts));
+       } else {
+               setup_data();
+               bcopy(ztest_shared_opts, &ztest_opts, sizeof (ztest_opts));
+       }
+       ASSERT3U(ztest_opts.zo_datasets, ==, ztest_shared_hdr->zh_ds_count);
 
        /* Override location of zpool.cache */
-       VERIFY(asprintf((char **)&spa_config_path, "%s/zpool.cache",
-           zopt_dir) != -1);
-
-       /*
-        * Blow away any existing copy of zpool.cache
-        */
-       if (zopt_init != 0)
-               (void) remove(spa_config_path);
-
-       shared_size = sizeof (*zs) + zopt_datasets * sizeof (ztest_ds_t);
+       (void) asprintf((char **)&spa_config_path, "%s/zpool.cache",
+           ztest_opts.zo_dir);
+       
+       ztest_ds = umem_alloc(ztest_opts.zo_datasets * sizeof (ztest_ds_t),
+           UMEM_NOFAIL);
+       zs = ztest_shared;
+
+       if (ischild) {
+               metaslab_gang_bang = ztest_opts.zo_metaslab_gang_bang;
+               metaslab_df_alloc_threshold =
+                   zs->zs_metaslab_df_alloc_threshold;
+
+               if (zs->zs_do_init)
+                       ztest_run_init();
+               else
+                       ztest_run(zs);
+               exit(0);
+       }
 
-       zs = ztest_shared = (void *)mmap(0,
-           P2ROUNDUP(shared_size, getpagesize()),
-           PROT_READ | PROT_WRITE, MAP_SHARED | MAP_ANON, -1, 0);
+       hasalt = (strlen(ztest_opts.zo_alt_ztest) != 0);
 
-       if (zopt_verbose >= 1) {
+       if (ztest_opts.zo_verbose >= 1) {
                (void) printf("%llu vdevs, %d datasets, %d threads,"
                    " %llu seconds...\n",
-                   (u_longlong_t)zopt_vdevs, zopt_datasets, zopt_threads,
-                   (u_longlong_t)zopt_time);
+                   (u_longlong_t)ztest_opts.zo_vdevs,
+                   ztest_opts.zo_datasets,
+                   ztest_opts.zo_threads,
+                   (u_longlong_t)ztest_opts.zo_time);
        }
 
-       /*
-        * Create and initialize our storage pool.
-        */
-       for (i = 1; i <= zopt_init; i++) {
-               bzero(zs, sizeof (ztest_shared_t));
-               if (zopt_verbose >= 3 && zopt_init != 1)
-                       (void) printf("ztest_init(), pass %d\n", i);
-               zs->zs_pool = zopt_pool;
-               ztest_init(zs);
+       (void) strlcpy(cmd, getexecname(), sizeof (cmd));
+
+       zs->zs_do_init = B_TRUE;
+       if (strlen(ztest_opts.zo_alt_ztest) != 0) {
+               if (ztest_opts.zo_verbose >= 1) {
+                       (void) printf("Executing older ztest for "
+                           "initialization: %s\n", ztest_opts.zo_alt_ztest);
+               }
+               VERIFY(!exec_child(ztest_opts.zo_alt_ztest,
+                   ztest_opts.zo_alt_libpath, B_FALSE, NULL));
+       } else {
+               VERIFY(!exec_child(NULL, NULL, B_FALSE, NULL));
        }
+       zs->zs_do_init = B_FALSE;
 
-       zs->zs_pool = zopt_pool;
        zs->zs_proc_start = gethrtime();
-       zs->zs_proc_stop = zs->zs_proc_start + zopt_time * NANOSEC;
+       zs->zs_proc_stop = zs->zs_proc_start + ztest_opts.zo_time * NANOSEC;
 
        for (f = 0; f < ZTEST_FUNCS; f++) {
-               zi = &zs->zs_info[f];
-               *zi = ztest_info[f];
+               zi = &ztest_info[f];
+               zc = ZTEST_GET_SHARED_CALLSTATE(f);
                if (zs->zs_proc_start + zi->zi_interval[0] > zs->zs_proc_stop)
-                       zi->zi_call_next = UINT64_MAX;
+                       zc->zc_next = UINT64_MAX;
                else
-                       zi->zi_call_next = zs->zs_proc_start +
+                       zc->zc_next = zs->zs_proc_start +
                            ztest_random(2 * zi->zi_interval[0] + 1);
        }
 
@@ -5744,60 +6077,43 @@ main(int argc, char **argv)
         */
        while (gethrtime() < zs->zs_proc_stop) {
                int status;
-               pid_t pid;
+               boolean_t killed;
 
                /*
                 * Initialize the workload counters for each function.
                 */
                for (f = 0; f < ZTEST_FUNCS; f++) {
-                       zi = &zs->zs_info[f];
-                       zi->zi_call_count = 0;
-                       zi->zi_call_time = 0;
+                       zc = ZTEST_GET_SHARED_CALLSTATE(f);
+                       zc->zc_count = 0;
+                       zc->zc_time = 0;
                }
 
                /* Set the allocation switch size */
-               metaslab_df_alloc_threshold = ztest_random(metaslab_sz / 4) + 1;
+               zs->zs_metaslab_df_alloc_threshold =
+                   ztest_random(zs->zs_metaslab_sz / 4) + 1;
 
-               pid = fork();
-
-               if (pid == -1)
-                       fatal(1, "fork failed");
-
-               if (pid == 0) { /* child */
-                       struct rlimit rl = { 1024, 1024 };
-                       (void) setrlimit(RLIMIT_NOFILE, &rl);
-                       (void) enable_extended_FILE_stdio(-1, -1);
-                       ztest_run(zs);
-                       exit(0);
-               }
-
-               while (waitpid(pid, &status, 0) != pid)
-                       continue;
-
-               if (WIFEXITED(status)) {
-                       if (WEXITSTATUS(status) != 0) {
-                               (void) fprintf(stderr,
-                                   "child exited with code %d\n",
-                                   WEXITSTATUS(status));
-                               exit(2);
-                       }
-               } else if (WIFSIGNALED(status)) {
-                       if (WTERMSIG(status) != SIGKILL) {
-                               (void) fprintf(stderr,
-                                   "child died with signal %d\n",
-                                   WTERMSIG(status));
-                               exit(3);
+               if (!hasalt || ztest_random(2) == 0) {
+                       if (hasalt && ztest_opts.zo_verbose >= 1) {
+                               (void) printf("Executing newer ztest: %s\n",
+                                   cmd);
                        }
-                       kills++;
+                       newer++;
+                       killed = exec_child(cmd, NULL, B_TRUE, &status);
                } else {
-                       (void) fprintf(stderr, "something strange happened "
-                           "to child\n");
-                       exit(4);
+                       if (hasalt && ztest_opts.zo_verbose >= 1) {
+                               (void) printf("Executing older ztest: %s\n",
+                                   ztest_opts.zo_alt_ztest);
+                       }
+                       older++;
+                       killed = exec_child(ztest_opts.zo_alt_ztest,
+                           ztest_opts.zo_alt_libpath, B_TRUE, &status);
                }
 
+               if (killed)
+                       kills++;
                iters++;
 
-               if (zopt_verbose >= 1) {
+               if (ztest_opts.zo_verbose >= 1) {
                        hrtime_t now = gethrtime();
 
                        now = MIN(now, zs->zs_proc_stop);
@@ -5812,10 +6128,10 @@ main(int argc, char **argv)
                            100.0 * zs->zs_alloc / zs->zs_space,
                            numbuf,
                            100.0 * (now - zs->zs_proc_start) /
-                           (zopt_time * NANOSEC), timebuf);
+                           (ztest_opts.zo_time * NANOSEC), timebuf);
                }
 
-               if (zopt_verbose >= 2) {
+               if (ztest_opts.zo_verbose >= 2) {
                        (void) printf("\nWorkload summary:\n\n");
                        (void) printf("%7s %9s   %s\n",
                            "Calls", "Time", "Function");
@@ -5824,11 +6140,12 @@ main(int argc, char **argv)
                        for (f = 0; f < ZTEST_FUNCS; f++) {
                                Dl_info dli;
 
-                               zi = &zs->zs_info[f];
-                               print_time(zi->zi_call_time, timebuf);
+                               zi = &ztest_info[f];
+                               zc = ZTEST_GET_SHARED_CALLSTATE(f);
+                               print_time(zc->zc_time, timebuf);
                                (void) dladdr((void *)zi->zi_func, &dli);
                                (void) printf("%7llu %9s   %s\n",
-                                   (u_longlong_t)zi->zi_call_count, timebuf,
+                                   (u_longlong_t)zc->zc_count, timebuf,
                                    dli.dli_sname);
                        }
                        (void) printf("\n");
@@ -5840,22 +6157,28 @@ main(int argc, char **argv)
                 * instead of 'ztest'.  Do a blind rename in case this happened.
                 */
                kernel_init(FREAD);
-               if (spa_open(zopt_pool, &spa, FTAG) == 0) {
+               if (spa_open(ztest_opts.zo_pool, &spa, FTAG) == 0) {
                        spa_close(spa, FTAG);
                } else {
                        char tmpname[MAXNAMELEN];
                        kernel_fini();
                        kernel_init(FREAD | FWRITE);
                        (void) snprintf(tmpname, sizeof (tmpname), "%s_tmp",
-                           zopt_pool);
-                       (void) spa_rename(tmpname, zopt_pool);
+                           ztest_opts.zo_pool);
+                       (void) spa_rename(tmpname, ztest_opts.zo_pool);
                }
                kernel_fini();
 
-               ztest_run_zdb(zopt_pool);
+               ztest_run_zdb(ztest_opts.zo_pool);
        }
 
-       if (zopt_verbose >= 1) {
+       if (ztest_opts.zo_verbose >= 1) {
+               if (hasalt) {
+                       (void) printf("%d runs of older ztest: %s\n", older,
+                           ztest_opts.zo_alt_ztest);
+                       (void) printf("%d runs of newer ztest: %s\n", newer,
+                           cmd);
+               }
                (void) printf("%d killed, %d completed, %.0f%% kill rate\n",
                    kills, iters - kills, (100.0 * kills) / MAX(1, iters));
        }