Illumos #2882, #2883, #2900

2882 implement libzfs_core
2883 changing "canmount" property to "on" should not always remount dataset
2900 "zfs snapshot" should be able to create multiple, arbitrary snapshots at once

Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Chris Siden <christopher.siden@delphix.com>
Reviewed by: Garrett D'Amore <garrett@damore.org>
Reviewed by: Bill Pijewski <wdp@joyent.com>
Reviewed by: Dan Kruchinin <dan.kruchinin@gmail.com>
Approved by: Eric Schrock <Eric.Schrock@delphix.com>

References:
  https://www.illumos.org/issues/2882
  https://www.illumos.org/issues/2883
  https://www.illumos.org/issues/2900
  illumos/illumos-gate@4445fffbbb

Ported-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #1293

Porting notes:

WARNING: This patch changes the user/kernel ABI.  That means that
the zfs/zpool utilities built from master are NOT compatible with
the 0.6.2 kernel modules.  Ensure you load the matching kernel
modules from master after updating the utilities.  Otherwise the
zfs/zpool commands will be unable to interact with your pool and
you will see errors similar to the following:

  $ zpool list
  failed to read pool configuration: bad address
  no pools available

  $ zfs list
  no datasets available

Add zvol minor device creation to the new zfs_snapshot_nvl function.

Remove the logging of the "release" operation in
dsl_dataset_user_release_sync().  The logging caused a null dereference
because ds->ds_dir is zeroed in dsl_dataset_destroy_sync() and the
logging functions try to get the ds name via the dsl_dataset_name()
function. I've got no idea why this particular code would have worked
in Illumos.  This code has subsequently been completely reworked in
Illumos commit 3b2aab1 (3464 zfs synctask code needs restructuring).

Squash some "may be used uninitialized" warning/erorrs.

Fix some printf format warnings for %lld and %llu.

Apply a few spa_writeable() changes that were made to Illumos in
illumos/illumos-gate.git@cd1c8b8 as part of the 3112, 3113, 3114 and
3115 fixes.

Add a missing call to fnvlist_free(nvl) in log_internal() that was added
in Illumos to fix issue 3085 but couldn't be ported to ZoL at the time
(zfsonlinux/zfs@9e11c73) because it depended on future work.

lib/Makefile.am

@@ -4,4 +4,4 @@ SUBDIRS = libspl libavl libefi libshare libunicode
 
 # These four libraries, which are installed as the final build product,
 # incorporate the five convenience libraries given above.
-SUBDIRS += libuutil libnvpair libzpool libzfs
+SUBDIRS += libuutil libnvpair libzpool libzfs_core libzfs

lib/libzfs/Makefile.am

@@ -22,6 +22,7 @@ libzfs_la_SOURCES = \
 	$(top_srcdir)/lib/libzfs/libzfs_util.c
 
 libzfs_la_LIBADD = \
+	$(top_builddir)/lib/libzfs_core/libzfs_core.la \
 	$(top_builddir)/lib/libshare/libshare.la \
 	$(top_builddir)/lib/libnvpair/libnvpair.la \
 	$(top_builddir)/lib/libzpool/libzpool.la

lib/libzfs/libzfs_config.c

@@ -106,7 +106,7 @@ namespace_reload(libzfs_handle_t *hdl)
 	nvlist_t *config;
 	config_node_t *cn;
 	nvpair_t *elem;
-	zfs_cmd_t zc = { "\0", "\0", "\0", "\0", 0 };
+	zfs_cmd_t zc = {"\0", 0, 0, 0, 0, 0, 0, 0, "\0", "\0", "\0"};
 	void *cookie;
 
 	if (hdl->libzfs_ns_gen == 0) {
@@ -261,7 +261,7 @@ zpool_get_features(zpool_handle_t *zhp)
 int
 zpool_refresh_stats(zpool_handle_t *zhp, boolean_t *missing)
 {
-	zfs_cmd_t zc = { "\0", "\0", "\0", "\0", 0 };
+	zfs_cmd_t zc = {"\0", 0, 0, 0, 0, 0, 0, 0, "\0", "\0", "\0"};
 	int error;
 	nvlist_t *config;
 	libzfs_handle_t *hdl = zhp->zpool_hdl;

lib/libzfs/libzfs_dataset.c

@@ -313,7 +313,7 @@ get_recvd_props_ioctl(zfs_handle_t *zhp)
 {
 	libzfs_handle_t *hdl = zhp->zfs_hdl;
 	nvlist_t *recvdprops;
-	zfs_cmd_t zc = { "\0", "\0", "\0", "\0", 0 };
+	zfs_cmd_t zc = {"\0", 0, 0, 0, 0, 0, 0, 0, "\0", "\0", "\0"};
 	int err;
 
 	if (zcmd_alloc_dst_nvlist(hdl, &zc, 0) != 0)
@@ -376,7 +376,7 @@ static int
 get_stats(zfs_handle_t *zhp)
 {
 	int rc = 0;
-	zfs_cmd_t zc = { "\0", "\0", "\0", "\0", 0 };
+	zfs_cmd_t zc = {"\0", 0, 0, 0, 0, 0, 0, 0, "\0", "\0", "\0"};
 
 	if (zcmd_alloc_dst_nvlist(zhp->zfs_hdl, &zc, 0) != 0)
 		return (-1);
@@ -439,7 +439,7 @@ make_dataset_handle_common(zfs_handle_t *zhp, zfs_cmd_t *zc)
 zfs_handle_t *
 make_dataset_handle(libzfs_handle_t *hdl, const char *path)
 {
-	zfs_cmd_t zc = { "\0", "\0", "\0", "\0", 0 };
+	zfs_cmd_t zc = {"\0", 0, 0, 0, 0, 0, 0, 0, "\0", "\0", "\0"};
 
 	zfs_handle_t *zhp = calloc(sizeof (zfs_handle_t), 1);
 
@@ -1427,15 +1427,14 @@ zfs_is_namespace_prop(zfs_prop_t prop)
 int
 zfs_prop_set(zfs_handle_t *zhp, const char *propname, const char *propval)
 {
-	zfs_cmd_t zc = { "\0", "\0", "\0", "\0", 0 };
+	zfs_cmd_t zc = {"\0", 0, 0, 0, 0, 0, 0, 0, "\0", "\0", "\0"};
 	int ret = -1;
 	prop_changelist_t *cl = NULL;
 	char errbuf[1024];
 	libzfs_handle_t *hdl = zhp->zfs_hdl;
 	nvlist_t *nvl = NULL, *realprops;
 	zfs_prop_t prop;
-	boolean_t do_prefix;
-	uint64_t idx;
+	boolean_t do_prefix = B_TRUE;
 	int added_resv = 0;
 
 	(void) snprintf(errbuf, sizeof (errbuf),
@@ -1474,12 +1473,17 @@ zfs_prop_set(zfs_handle_t *zhp, const char *propname, const char *propval)
 	}
 
 	/*
-	 * If the dataset's canmount property is being set to noauto,
-	 * then we want to prevent unmounting & remounting it.
+	 * We don't want to unmount & remount the dataset when changing
+	 * its canmount property to 'on' or 'noauto'.  We only use
+	 * the changelist logic to unmount when setting canmount=off.
 	 */
-	do_prefix = !((prop == ZFS_PROP_CANMOUNT) &&
-	    (zprop_string_to_index(prop, propval, &idx,
-	    ZFS_TYPE_DATASET) == 0) && (idx == ZFS_CANMOUNT_NOAUTO));
+	if (prop == ZFS_PROP_CANMOUNT) {
+		uint64_t idx;
+		int err = zprop_string_to_index(prop, propval, &idx,
+		    ZFS_TYPE_DATASET);
+		if (err == 0 && idx != ZFS_CANMOUNT_OFF)
+			do_prefix = B_FALSE;
+	}
 
 	if (do_prefix && (ret = changelist_prefix(cl)) != 0)
 		goto error;
@@ -1549,7 +1553,7 @@ error:
 int
 zfs_prop_inherit(zfs_handle_t *zhp, const char *propname, boolean_t received)
 {
-	zfs_cmd_t zc = { "\0", "\0", "\0", "\0", 0 };
+	zfs_cmd_t zc = {"\0", 0, 0, 0, 0, 0, 0, 0, "\0", "\0", "\0"};
 	int ret;
 	prop_changelist_t *cl;
 	libzfs_handle_t *hdl = zhp->zfs_hdl;
@@ -1724,7 +1728,7 @@ static int
 get_numeric_property(zfs_handle_t *zhp, zfs_prop_t prop, zprop_source_t *src,
     char **source, uint64_t *val)
 {
-	zfs_cmd_t zc = { "\0", "\0", "\0", "\0", 0 };
+	zfs_cmd_t zc = {"\0", 0, 0, 0, 0, 0, 0, 0, "\0", "\0", "\0"};
 	nvlist_t *zplprops = NULL;
 	struct mnttab mnt;
 	char *mntopt_on = NULL;
@@ -2576,7 +2580,7 @@ zfs_prop_get_userquota_common(zfs_handle_t *zhp, const char *propname,
     uint64_t *propvalue, zfs_userquota_prop_t *typep)
 {
 	int err;
-	zfs_cmd_t zc = { "\0", "\0", "\0", "\0", 0 };
+	zfs_cmd_t zc = {"\0", 0, 0, 0, 0, 0, 0, 0, "\0", "\0", "\0"};
 
 	(void) strlcpy(zc.zc_name, zhp->zfs_name, sizeof (zc.zc_name));
 
@@ -2636,7 +2640,7 @@ zfs_prop_get_written_int(zfs_handle_t *zhp, const char *propname,
     uint64_t *propvalue)
 {
 	int err;
-	zfs_cmd_t zc = { "\0", "\0", "\0", "\0", 0 };
+	zfs_cmd_t zc = {"\0", 0, 0, 0, 0, 0, 0, 0, "\0", "\0", "\0"};
 	const char *snapname;
 
 	(void) strlcpy(zc.zc_name, zhp->zfs_name, sizeof (zc.zc_name));
@@ -2686,25 +2690,6 @@ zfs_prop_get_written(zfs_handle_t *zhp, const char *propname,
 	return (0);
 }
 
-int
-zfs_get_snapused_int(zfs_handle_t *firstsnap, zfs_handle_t *lastsnap,
-    uint64_t *usedp)
-{
-	int err;
-	zfs_cmd_t zc = { "\0", "\0", "\0", "\0", 0 };
-
-	(void) strlcpy(zc.zc_name, lastsnap->zfs_name, sizeof (zc.zc_name));
-	(void) strlcpy(zc.zc_value, firstsnap->zfs_name, sizeof (zc.zc_value));
-
-	err = ioctl(lastsnap->zfs_hdl->libzfs_fd, ZFS_IOC_SPACE_SNAPS, &zc);
-	if (err)
-		return (err);
-
-	*usedp = zc.zc_cookie;
-
-	return (0);
-}
-
 /*
  * Returns the name of the given zfs handle.
  */
@@ -2775,7 +2760,7 @@ static int
 check_parents(libzfs_handle_t *hdl, const char *path, uint64_t *zoned,
     boolean_t accept_ancestor, int *prefixlen)
 {
-	zfs_cmd_t zc = { "\0", "\0", "\0", "\0", 0 };
+	zfs_cmd_t zc = {"\0", 0, 0, 0, 0, 0, 0, 0, "\0", "\0", "\0"};
 	char parent[ZFS_MAXNAMELEN];
 	char *slash;
 	zfs_handle_t *zhp;
@@ -2905,7 +2890,6 @@ create_parents(libzfs_handle_t *hdl, char *target, int prefixlen)
 	 */
 	for (cp = target + prefixlen + 1;
 	    (cp = strchr(cp, '/')); *cp = '/', cp++) {
-		char *logstr;
 
 		*cp = '\0';
 
@@ -2916,16 +2900,12 @@ create_parents(libzfs_handle_t *hdl, char *target, int prefixlen)
 			continue;
 		}
 
-		logstr = hdl->libzfs_log_str;
-		hdl->libzfs_log_str = NULL;
 		if (zfs_create(hdl, target, ZFS_TYPE_FILESYSTEM,
 		    NULL) != 0) {
-			hdl->libzfs_log_str = logstr;
 			opname = dgettext(TEXT_DOMAIN, "create");
 			goto ancestorerr;
 		}
 
-		hdl->libzfs_log_str = logstr;
 		h = zfs_open(hdl, target, ZFS_TYPE_FILESYSTEM);
 		if (h == NULL) {
 			opname = dgettext(TEXT_DOMAIN, "open");
@@ -2983,12 +2963,12 @@ int
 zfs_create(libzfs_handle_t *hdl, const char *path, zfs_type_t type,
     nvlist_t *props)
 {
-	zfs_cmd_t zc = { "\0", "\0", "\0", "\0", 0 };
 	int ret;
 	uint64_t size = 0;
 	uint64_t blocksize = zfs_prop_default_numeric(ZFS_PROP_VOLBLOCKSIZE);
 	char errbuf[1024];
 	uint64_t zoned;
+	dmu_objset_type_t ost;
 
 	(void) snprintf(errbuf, sizeof (errbuf), dgettext(TEXT_DOMAIN,
 	    "cannot create '%s'"), path);
@@ -3008,17 +2988,16 @@ zfs_create(libzfs_handle_t *hdl, const char *path, zfs_type_t type,
 	 * will return ENOENT, not EEXIST.  To prevent this from happening, we
 	 * first try to see if the dataset exists.
 	 */
-	(void) strlcpy(zc.zc_name, path, sizeof (zc.zc_name));
-	if (zfs_dataset_exists(hdl, zc.zc_name, ZFS_TYPE_DATASET)) {
+	if (zfs_dataset_exists(hdl, path, ZFS_TYPE_DATASET)) {
 		zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
 		    "dataset already exists"));
 		return (zfs_error(hdl, EZFS_EXISTS, errbuf));
 	}
 
 	if (type == ZFS_TYPE_VOLUME)
-		zc.zc_objset_type = DMU_OST_ZVOL;
+		ost = DMU_OST_ZVOL;
 	else
-		zc.zc_objset_type = DMU_OST_ZFS;
+		ost = DMU_OST_ZFS;
 
 	if (props && (props = zfs_valid_proplist(hdl, type, props,
 	    zoned, NULL, errbuf)) == 0)
@@ -3070,12 +3049,9 @@ zfs_create(libzfs_handle_t *hdl, const char *path, zfs_type_t type,
 		}
 	}
 
-	if (props && zcmd_write_src_nvlist(hdl, &zc, props) != 0)
-		return (-1);
-	nvlist_free(props);
-
 	/* create the dataset */
-	ret = zfs_ioctl(hdl, ZFS_IOC_CREATE, &zc);
+	ret = lzc_create(path, ost, props);
+	nvlist_free(props);
 
 	if (ret == 0 && type == ZFS_TYPE_VOLUME) {
 		ret = zvol_create_link(hdl, path);
@@ -3084,13 +3060,10 @@ zfs_create(libzfs_handle_t *hdl, const char *path, zfs_type_t type,
 			    dgettext(TEXT_DOMAIN,
 			    "Volume successfully created, but device links "
 			    "were not created"));
-			zcmd_free_nvlists(&zc);
 			return (-1);
 		}
 	}
 
-	zcmd_free_nvlists(&zc);
-
 	/* check for failure */
 	if (ret != 0) {
 		char parent[ZFS_MAXNAMELEN];
@@ -3147,7 +3120,7 @@ zfs_create(libzfs_handle_t *hdl, const char *path, zfs_type_t type,
 int
 zfs_destroy(zfs_handle_t *zhp, boolean_t defer)
 {
-	zfs_cmd_t zc = { "\0", "\0", "\0", "\0", 0 };
+	zfs_cmd_t zc = {"\0", 0, 0, 0, 0, 0, 0, 0, "\0", "\0", "\0"};
 
 	(void) strlcpy(zc.zc_name, zhp->zfs_name, sizeof (zc.zc_name));
 
@@ -3241,33 +3214,36 @@ int
 zfs_destroy_snaps_nvl(zfs_handle_t *zhp, nvlist_t *snaps, boolean_t defer)
 {
 	int ret;
-	zfs_cmd_t zc = { "\0", "\0", "\0", "\0", 0 };
+	nvlist_t *errlist;
 
-	(void) strlcpy(zc.zc_name, zhp->zfs_name, sizeof (zc.zc_name));
-	if (zcmd_write_src_nvlist(zhp->zfs_hdl, &zc, snaps) != 0)
-		return (-1);
-	zc.zc_defer_destroy = defer;
+	ret = lzc_destroy_snaps(snaps, defer, &errlist);
 
-	ret = zfs_ioctl(zhp->zfs_hdl, ZFS_IOC_DESTROY_SNAPS_NVL, &zc);
 	if (ret != 0) {
-		char errbuf[1024];
+		nvpair_t *pair;
+		for (pair = nvlist_next_nvpair(errlist, NULL);
+		    pair != NULL; pair = nvlist_next_nvpair(errlist, pair)) {
+			char errbuf[1024];
+			(void) snprintf(errbuf, sizeof (errbuf),
+			    dgettext(TEXT_DOMAIN, "cannot destroy snapshot %s"),
+			    nvpair_name(pair));
 
-		(void) snprintf(errbuf, sizeof (errbuf), dgettext(TEXT_DOMAIN,
-		    "cannot destroy snapshots in %s"), zc.zc_name);
-
-		switch (errno) {
-		case EEXIST:
-			zfs_error_aux(zhp->zfs_hdl, dgettext(TEXT_DOMAIN,
-			    "snapshot is cloned"));
-			return (zfs_error(zhp->zfs_hdl, EZFS_EXISTS, errbuf));
-
-		default:
-			return (zfs_standard_error(zhp->zfs_hdl, errno,
-			    errbuf));
+			switch (fnvpair_value_int32(pair)) {
+			case EEXIST:
+				zfs_error_aux(zhp->zfs_hdl,
+				    dgettext(TEXT_DOMAIN,
+				    "snapshot is cloned"));
+				ret = zfs_error(zhp->zfs_hdl, EZFS_EXISTS,
+				    errbuf);
+				break;
+			default:
+				ret = zfs_standard_error(zhp->zfs_hdl, errno,
+				    errbuf);
+				break;
+			}
 		}
 	}
 
-	return (0);
+	return (ret);
 }
 
 /*
@@ -3276,12 +3252,10 @@ zfs_destroy_snaps_nvl(zfs_handle_t *zhp, nvlist_t *snaps, boolean_t defer)
 int
 zfs_clone(zfs_handle_t *zhp, const char *target, nvlist_t *props)
 {
-	zfs_cmd_t zc = { "\0", "\0", "\0", "\0", 0 };
 	char parent[ZFS_MAXNAMELEN];
 	int ret;
 	char errbuf[1024];
 	libzfs_handle_t *hdl = zhp->zfs_hdl;
-	zfs_type_t type;
 	uint64_t zoned;
 
 	assert(zhp->zfs_type == ZFS_TYPE_SNAPSHOT);
@@ -3300,32 +3274,21 @@ zfs_clone(zfs_handle_t *zhp, const char *target, nvlist_t *props)
 	(void) parent_name(target, parent, sizeof (parent));
 
 	/* do the clone */
-	if (ZFS_IS_VOLUME(zhp)) {
-		zc.zc_objset_type = DMU_OST_ZVOL;
-		type = ZFS_TYPE_VOLUME;
-	} else {
-		zc.zc_objset_type = DMU_OST_ZFS;
-		type = ZFS_TYPE_FILESYSTEM;
-	}
 
 	if (props) {
+		zfs_type_t type;
+		if (ZFS_IS_VOLUME(zhp)) {
+			type = ZFS_TYPE_VOLUME;
+		} else {
+			type = ZFS_TYPE_FILESYSTEM;
+		}
 		if ((props = zfs_valid_proplist(hdl, type, props, zoned,
 		    zhp, errbuf)) == NULL)
 			return (-1);
-
-		if (zcmd_write_src_nvlist(hdl, &zc, props) != 0) {
-			nvlist_free(props);
-			return (-1);
-		}
-
-		nvlist_free(props);
 	}
 
-	(void) strlcpy(zc.zc_name, target, sizeof (zc.zc_name));
-	(void) strlcpy(zc.zc_value, zhp->zfs_name, sizeof (zc.zc_value));
-	ret = zfs_ioctl(zhp->zfs_hdl, ZFS_IOC_CREATE, &zc);
-
-	zcmd_free_nvlists(&zc);
+	ret = lzc_clone(target, zhp->zfs_name, props);
+	nvlist_free(props);
 
 	if (ret != 0) {
 		switch (errno) {
@@ -3425,7 +3388,7 @@ int
 zfs_promote(zfs_handle_t *zhp)
 {
 	libzfs_handle_t *hdl = zhp->zfs_hdl;
-	zfs_cmd_t zc = { "\0", "\0", "\0", "\0", 0 };
+	zfs_cmd_t zc = {"\0", 0, 0, 0, 0, 0, 0, 0, "\0", "\0", "\0"};
 	char parent[MAXPATHLEN];
 	char *cp;
 	int ret;
@@ -3540,94 +3503,159 @@ zfs_create_link_cb(zfs_handle_t *zhp, void *arg)
 	return (ret);
 }
 
+typedef struct snapdata {
+	nvlist_t *sd_nvl;
+	const char *sd_snapname;
+} snapdata_t;
+
+static int
+zfs_snapshot_cb(zfs_handle_t *zhp, void *arg)
+{
+	snapdata_t *sd = arg;
+	char name[ZFS_MAXNAMELEN];
+	int rv = 0;
+
+	(void) snprintf(name, sizeof (name),
+	    "%s@%s", zfs_get_name(zhp), sd->sd_snapname);
+
+	fnvlist_add_boolean(sd->sd_nvl, name);
+
+	rv = zfs_iter_filesystems(zhp, zfs_snapshot_cb, sd);
+	zfs_close(zhp);
+	return (rv);
+}
+
 /*
- * Takes a snapshot of the given dataset.
+ * Creates snapshots.  The keys in the snaps nvlist are the snapshots to be
+ * created.
  */
+int
+zfs_snapshot_nvl(libzfs_handle_t *hdl, nvlist_t *snaps, nvlist_t *props)
+{
+	int ret;
+	char errbuf[1024];
+	nvpair_t *elem;
+	nvlist_t *errors;
+
+	(void) snprintf(errbuf, sizeof (errbuf), dgettext(TEXT_DOMAIN,
+	    "cannot create snapshots "));
+
+	elem = NULL;
+	while ((elem = nvlist_next_nvpair(snaps, elem)) != NULL) {
+		const char *snapname = nvpair_name(elem);
+
+		/* validate the target name */
+		if (!zfs_validate_name(hdl, snapname, ZFS_TYPE_SNAPSHOT,
+		    B_TRUE)) {
+			(void) snprintf(errbuf, sizeof (errbuf),
+			    dgettext(TEXT_DOMAIN,
+			    "cannot create snapshot '%s'"), snapname);
+			return (zfs_error(hdl, EZFS_INVALIDNAME, errbuf));
+		}
+	}
+
+	if (props != NULL &&
+	    (props = zfs_valid_proplist(hdl, ZFS_TYPE_SNAPSHOT,
+	    props, B_FALSE, NULL, errbuf)) == NULL) {
+		return (-1);
+	}
+
+	ret = lzc_snapshot(snaps, props, &errors);
+
+	if (ret != 0) {
+		boolean_t printed = B_FALSE;
+		for (elem = nvlist_next_nvpair(errors, NULL);
+		    elem != NULL;
+		    elem = nvlist_next_nvpair(errors, elem)) {
+			(void) snprintf(errbuf, sizeof (errbuf),
+			    dgettext(TEXT_DOMAIN,
+			    "cannot create snapshot '%s'"), nvpair_name(elem));
+			(void) zfs_standard_error(hdl,
+			    fnvpair_value_int32(elem), errbuf);
+			printed = B_TRUE;
+		}
+		if (!printed) {
+			switch (ret) {
+			case EXDEV:
+				zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
+				    "multiple snapshots of same "
+				    "fs not allowed"));
+				(void) zfs_error(hdl, EZFS_EXISTS, errbuf);
+
+				break;
+			default:
+				(void) zfs_standard_error(hdl, ret, errbuf);
+			}
+		}
+	} else {
+		zfs_handle_t *zhp;
+		int linktries = 0, linkok = 0, linkfail = 0;
+		nvpair_t *snap;
+
+		for (snap = nvlist_next_nvpair(snaps, NULL); snap != NULL;
+		    snap = nvlist_next_nvpair(snaps, snap)) {
+			char *cp, *snapname;
+
+			snapname = nvpair_name(snap);
+			cp = strchr(snapname, '@');
+			*cp = '\0';
+
+			if ((zhp = zfs_open(hdl, snapname, ZFS_TYPE_FILESYSTEM |
+				ZFS_TYPE_VOLUME)) != NULL) {
+				if (zhp->zfs_type == ZFS_TYPE_VOLUME) {
+					++linktries;
+					*cp = '@';
+					if (zvol_create_link(zhp->zfs_hdl, nvpair_name(snap)))
+						++linkfail;
+					else
+						++linkok;
+				}
+			}
+		}
+	}
+
+	nvlist_free(props);
+	nvlist_free(errors);
+	return (ret);
+}
+
 int
 zfs_snapshot(libzfs_handle_t *hdl, const char *path, boolean_t recursive,
     nvlist_t *props)
 {
-	const char *delim;
-	char parent[ZFS_MAXNAMELEN];
-	zfs_handle_t *zhp;
-	zfs_cmd_t zc = { "\0", "\0", "\0", "\0", 0 };
 	int ret;
+	snapdata_t sd = { 0 };
+	char fsname[ZFS_MAXNAMELEN];
+	char *cp;
+	zfs_handle_t *zhp;
 	char errbuf[1024];
 
 	(void) snprintf(errbuf, sizeof (errbuf), dgettext(TEXT_DOMAIN,
-	    "cannot snapshot '%s'"), path);
+	    "cannot snapshot %s"), path);
 
-	/* validate the target name */
 	if (!zfs_validate_name(hdl, path, ZFS_TYPE_SNAPSHOT, B_TRUE))
 		return (zfs_error(hdl, EZFS_INVALIDNAME, errbuf));
+ 
+	(void) strlcpy(fsname, path, sizeof (fsname));
+	cp = strchr(fsname, '@');
+	*cp = '\0';
+	sd.sd_snapname = cp + 1;
 
-	if (props) {
-		if ((props = zfs_valid_proplist(hdl, ZFS_TYPE_SNAPSHOT,
-		    props, B_FALSE, NULL, errbuf)) == NULL)
-			return (-1);
-
-		if (zcmd_write_src_nvlist(hdl, &zc, props) != 0) {
-			nvlist_free(props);
-			return (-1);
-		}
-
-		nvlist_free(props);
-	}
-
-	/* make sure the parent exists and is of the appropriate type */
-	delim = strchr(path, '@');
-	(void) strncpy(parent, path, delim - path);
-	parent[delim - path] = '\0';
-
-	if ((zhp = zfs_open(hdl, parent, ZFS_TYPE_FILESYSTEM |
+	if ((zhp = zfs_open(hdl, fsname, ZFS_TYPE_FILESYSTEM |
 	    ZFS_TYPE_VOLUME)) == NULL) {
-		zcmd_free_nvlists(&zc);
 		return (-1);
 	}
 
-	(void) strlcpy(zc.zc_name, zhp->zfs_name, sizeof (zc.zc_name));
-	(void) strlcpy(zc.zc_value, delim+1, sizeof (zc.zc_value));
-	if (ZFS_IS_VOLUME(zhp))
-		zc.zc_objset_type = DMU_OST_ZVOL;
-	else
-		zc.zc_objset_type = DMU_OST_ZFS;
-	zc.zc_cookie = recursive;
-	ret = zfs_ioctl(zhp->zfs_hdl, ZFS_IOC_SNAPSHOT, &zc);
-
-	zcmd_free_nvlists(&zc);
-
-	/*
-	 * if it was recursive, the one that actually failed will be in
-	 * zc.zc_name.
-	 */
-	if (ret != 0)
-		(void) snprintf(errbuf, sizeof (errbuf), dgettext(TEXT_DOMAIN,
-		    "cannot create snapshot '%s@%s'"), zc.zc_name, zc.zc_value);
-
-	if (ret == 0 && recursive) {
-		struct createdata cd;
-
-		cd.cd_snapname = delim + 1;
-		cd.cd_ifexists = B_FALSE;
-		(void) zfs_iter_filesystems(zhp, zfs_create_link_cb, &cd);
-	}
-	if (ret == 0 && zhp->zfs_type == ZFS_TYPE_VOLUME) {
-		ret = zvol_create_link(zhp->zfs_hdl, path);
-		if (ret != 0) {
-			(void) zfs_standard_error(hdl, errno,
-			    dgettext(TEXT_DOMAIN,
-			    "Volume successfully snapshotted, but device links "
-			    "were not created"));
-			zfs_close(zhp);
-			return (-1);
-		}
+	verify(nvlist_alloc(&sd.sd_nvl, NV_UNIQUE_NAME, 0) == 0);
+	if (recursive) {
+		(void) zfs_snapshot_cb(zfs_handle_dup(zhp), &sd);
+	} else {
+		fnvlist_add_boolean(sd.sd_nvl, path);
 	}
 
-	if (ret != 0)
-		(void) zfs_standard_error(hdl, errno, errbuf);
-
+	ret = zfs_snapshot_nvl(hdl, sd.sd_nvl, props);
+	nvlist_free(sd.sd_nvl);
 	zfs_close(zhp);
-
 	return (ret);
 }
 
@@ -3655,17 +3683,13 @@ rollback_destroy(zfs_handle_t *zhp, void *data)
 		    zfs_get_type(zhp) == ZFS_TYPE_SNAPSHOT &&
 		    zfs_prop_get_int(zhp, ZFS_PROP_CREATETXG) >
 		    cbp->cb_create) {
-			char *logstr;
 
 			cbp->cb_dependent = B_TRUE;
 			cbp->cb_error |= zfs_iter_dependents(zhp, B_FALSE,
 			    rollback_destroy, cbp);
 			cbp->cb_dependent = B_FALSE;
 
-			logstr = zhp->zfs_hdl->libzfs_log_str;
-			zhp->zfs_hdl->libzfs_log_str = NULL;
 			cbp->cb_error |= zfs_destroy(zhp, B_FALSE);
-			zhp->zfs_hdl->libzfs_log_str = logstr;
 		}
 	} else {
 		/* We must destroy this clone; first unmount it */
@@ -3702,7 +3726,7 @@ zfs_rollback(zfs_handle_t *zhp, zfs_handle_t *snap, boolean_t force)
 {
 	rollback_data_t cb = { 0 };
 	int err;
-	zfs_cmd_t zc = { "\0", "\0", "\0", "\0", 0 };
+	zfs_cmd_t zc = {"\0", 0, 0, 0, 0, 0, 0, 0, "\0", "\0", "\0"};
 	boolean_t restore_resv = 0;
 	uint64_t old_volsize = 0, new_volsize;
 	zfs_prop_t resv_prop = { 0 };
@@ -3789,7 +3813,7 @@ zfs_rename(zfs_handle_t *zhp, const char *target, boolean_t recursive,
     boolean_t force_unmount)
 {
 	int ret;
-	zfs_cmd_t zc = { "\0", "\0", "\0", "\0", 0 };
+	zfs_cmd_t zc = {"\0", 0, 0, 0, 0, 0, 0, 0, "\0", "\0", "\0"};
 	char *delim;
 	prop_changelist_t *cl = NULL;
 	zfs_handle_t *zhrp = NULL;
@@ -4008,7 +4032,7 @@ zvol_create_link(libzfs_handle_t *hdl, const char *dataset)
 static int
 zvol_create_link_common(libzfs_handle_t *hdl, const char *dataset, int ifexists)
 {
-	zfs_cmd_t zc = { "\0", "\0", "\0", "\0", 0 };
+	zfs_cmd_t zc = {"\0", 0, 0, 0, 0, 0, 0, 0, "\0", "\0", "\0"};
 	char path[MAXPATHLEN];
 	int error;
 
@@ -4072,7 +4096,7 @@ zvol_create_link_common(libzfs_handle_t *hdl, const char *dataset, int ifexists)
 int
 zvol_remove_link(libzfs_handle_t *hdl, const char *dataset)
 {
-	zfs_cmd_t zc = { "\0", "\0", "\0", "\0", 0 };
+	zfs_cmd_t zc = {"\0", 0, 0, 0, 0, 0, 0, 0, "\0", "\0", "\0"};
 	int timeout = 3000; /* in milliseconds */
 	int error = 0;
 	int i;
@@ -4265,7 +4289,7 @@ static int
 zfs_smb_acl_mgmt(libzfs_handle_t *hdl, char *dataset, char *path,
     zfs_smb_acl_op_t cmd, char *resource1, char *resource2)
 {
-	zfs_cmd_t zc = { "\0", "\0", "\0", "\0", 0 };
+	zfs_cmd_t zc = {"\0", 0, 0, 0, 0, 0, 0, 0, "\0", "\0", "\0"};
 	nvlist_t *nvlist = NULL;
 	int error;
 
@@ -4347,7 +4371,7 @@ int
 zfs_userspace(zfs_handle_t *zhp, zfs_userquota_prop_t type,
     zfs_userspace_cb_t func, void *arg)
 {
-	zfs_cmd_t zc = { "\0", "\0", "\0", "\0", 0 };
+	zfs_cmd_t zc = {"\0", 0, 0, 0, 0, 0, 0, 0, "\0", "\0", "\0"};
 	zfs_useracct_t buf[100];
 	libzfs_handle_t *hdl = zhp->zfs_hdl;
 	int ret;
@@ -4389,7 +4413,7 @@ zfs_hold(zfs_handle_t *zhp, const char *snapname, const char *tag,
     boolean_t recursive, boolean_t temphold, boolean_t enoent_ok,
     int cleanup_fd, uint64_t dsobj, uint64_t createtxg)
 {
-	zfs_cmd_t zc = { "\0", "\0", "\0", "\0", 0 };
+	zfs_cmd_t zc = {"\0", 0, 0, 0, 0, 0, 0, 0, "\0", "\0", "\0"};
 	libzfs_handle_t *hdl = zhp->zfs_hdl;
 
 	ASSERT(!recursive || dsobj == 0);
@@ -4447,7 +4471,7 @@ int
 zfs_release(zfs_handle_t *zhp, const char *snapname, const char *tag,
     boolean_t recursive)
 {
-	zfs_cmd_t zc = { "\0", "\0", "\0", "\0", 0 };
+	zfs_cmd_t zc = {"\0", 0, 0, 0, 0, 0, 0, 0, "\0", "\0", "\0"};
 	libzfs_handle_t *hdl = zhp->zfs_hdl;
 
 	(void) strlcpy(zc.zc_name, zhp->zfs_name, sizeof (zc.zc_name));
@@ -4487,7 +4511,7 @@ zfs_release(zfs_handle_t *zhp, const char *snapname, const char *tag,
 int
 zfs_get_fsacl(zfs_handle_t *zhp, nvlist_t **nvl)
 {
-	zfs_cmd_t zc = { "\0", "\0", "\0", "\0", 0 };
+	zfs_cmd_t zc = {"\0", 0, 0, 0, 0, 0, 0, 0, "\0", "\0", "\0"};
 	libzfs_handle_t *hdl = zhp->zfs_hdl;
 	int nvsz = 2048;
 	void *nvbuf;
@@ -4554,7 +4578,7 @@ out:
 int
 zfs_set_fsacl(zfs_handle_t *zhp, boolean_t un, nvlist_t *nvl)
 {
-	zfs_cmd_t zc = { "\0", "\0", "\0", "\0", 0 };
+	zfs_cmd_t zc = {"\0", 0, 0, 0, 0, 0, 0, 0, "\0", "\0", "\0"};
 	libzfs_handle_t *hdl = zhp->zfs_hdl;
 	char *nvbuf;
 	char errbuf[ZFS_MAXNAMELEN+32];
@@ -4608,7 +4632,7 @@ zfs_set_fsacl(zfs_handle_t *zhp, boolean_t un, nvlist_t *nvl)
 int
 zfs_get_holds(zfs_handle_t *zhp, nvlist_t **nvl)
 {
-	zfs_cmd_t zc = { "\0", "\0", "\0", "\0", 0 };
+	zfs_cmd_t zc = {"\0", 0, 0, 0, 0, 0, 0, 0, "\0", "\0", "\0"};
 	libzfs_handle_t *hdl = zhp->zfs_hdl;
 	int nvsz = 2048;
 	void *nvbuf;

lib/libzfs/libzfs_diff.c

@@ -90,7 +90,7 @@ static int
 get_stats_for_obj(differ_info_t *di, const char *dsname, uint64_t obj,
     char *pn, int maxlen, zfs_stat_t *sb)
 {
-	zfs_cmd_t zc = { "\0", "\0", "\0", "\0", 0 };
+	zfs_cmd_t zc = {"\0", 0, 0, 0, 0, 0, 0, 0, "\0", "\0", "\0"};
 	int error;
 
 	(void) strlcpy(zc.zc_name, dsname, sizeof (zc.zc_name));
@@ -379,7 +379,7 @@ describe_free(FILE *fp, differ_info_t *di, uint64_t object, char *namebuf,
 static int
 write_free_diffs(FILE *fp, differ_info_t *di, dmu_diff_record_t *dr)
 {
-	zfs_cmd_t zc = { "\0", "\0", "\0", "\0", 0 };
+	zfs_cmd_t zc = {"\0", 0, 0, 0, 0, 0, 0, 0, "\0", "\0", "\0"};
 	libzfs_handle_t *lhdl = di->zhp->zfs_hdl;
 	char fobjname[MAXPATHLEN];
 
@@ -507,7 +507,7 @@ static int
 make_temp_snapshot(differ_info_t *di)
 {
 	libzfs_handle_t *hdl = di->zhp->zfs_hdl;
-	zfs_cmd_t zc = { "\0", "\0", "\0", "\0", 0 };
+	zfs_cmd_t zc = {"\0", 0, 0, 0, 0, 0, 0, 0, "\0", "\0", "\0"};
 
 	(void) snprintf(zc.zc_value, sizeof (zc.zc_value),
 	    ZDIFF_PREFIX, getpid());
@@ -749,7 +749,7 @@ int
 zfs_show_diffs(zfs_handle_t *zhp, int outfd, const char *fromsnap,
     const char *tosnap, int flags)
 {
-	zfs_cmd_t zc = { "\0", "\0", "\0", "\0", 0 };
+	zfs_cmd_t zc = {"\0", 0, 0, 0, 0, 0, 0, 0, "\0", "\0", "\0"};
 	char errbuf[1024];
 	differ_info_t di = { 0 };
 	pthread_t tid;

lib/libzfs/libzfs_fru.c

@@ -361,7 +361,7 @@ libzfs_fru_devpath(libzfs_handle_t *hdl, const char *fru)
 int
 zpool_fru_set(zpool_handle_t *zhp, uint64_t vdev_guid, const char *fru)
 {
-	zfs_cmd_t zc = { 0 };
+	zfs_cmd_t zc = {"\0", 0, 0, 0, 0, 0, 0, 0, "\0", "\0", "\0"};
 
 	(void) strncpy(zc.zc_name, zhp->zpool_name, sizeof (zc.zc_name));
 	(void) strncpy(zc.zc_value, fru, sizeof (zc.zc_value));

lib/libzfs/libzfs_graph.c

@@ -379,7 +379,7 @@ zfs_graph_add(libzfs_handle_t *hdl, zfs_graph_t *zgp, const char *source,
 static int
 iterate_children(libzfs_handle_t *hdl, zfs_graph_t *zgp, const char *dataset)
 {
-	zfs_cmd_t zc = { "\0", "\0", "\0", "\0", 0 };
+	zfs_cmd_t zc = {"\0", 0, 0, 0, 0, 0, 0, 0, "\0", "\0", "\0"};
 	zfs_vertex_t *zvp;
 
 	/*
@@ -473,7 +473,7 @@ iterate_children(libzfs_handle_t *hdl, zfs_graph_t *zgp, const char *dataset)
 static boolean_t
 external_dependents(libzfs_handle_t *hdl, zfs_graph_t *zgp, const char *dataset)
 {
-	zfs_cmd_t zc = { "\0", "\0", "\0", "\0", 0 };
+	zfs_cmd_t zc = {"\0", 0, 0, 0, 0, 0, 0, 0, "\0", "\0", "\0"};
 
 	/*
 	 * Check whether this dataset is a clone or has clones since

lib/libzfs/libzfs_import.c

@@ -365,7 +365,7 @@ static nvlist_t *
 refresh_config(libzfs_handle_t *hdl, nvlist_t *config)
 {
 	nvlist_t *nvl;
-	zfs_cmd_t zc = { "\0", "\0", "\0", "\0", 0 };
+	zfs_cmd_t zc = {"\0", 0, 0, 0, 0, 0, 0, 0, "\0", "\0", "\0"};
 	int err;
 
 	if (zcmd_write_conf_nvlist(hdl, &zc, config) != 0)

lib/libzfs/libzfs_iter.c

@@ -22,7 +22,7 @@
 /*
  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
  * Copyright 2010 Nexenta Systems, Inc. All rights reserved.
- * Copyright (c) 2011 by Delphix. All rights reserved.
+ * Copyright (c) 2012 by Delphix. All rights reserved.
  */
 
 #include <stdio.h>
@@ -103,7 +103,7 @@ top:
 int
 zfs_iter_filesystems(zfs_handle_t *zhp, zfs_iter_f func, void *data)
 {
-	zfs_cmd_t zc = { "\0", "\0", "\0", "\0", 0 };
+	zfs_cmd_t zc = {"\0", 0, 0, 0, 0, 0, 0, 0, "\0", "\0", "\0"};
 	zfs_handle_t *nzhp;
 	int ret;
 
@@ -140,7 +140,7 @@ int
 zfs_iter_snapshots(zfs_handle_t *zhp, boolean_t simple, zfs_iter_f func,
     void *data)
 {
-	zfs_cmd_t zc = { "\0", "\0", "\0", "\0", 0 };
+	zfs_cmd_t zc = {"\0", 0, 0, 0, 0, 0, 0, 0, "\0", "\0", "\0"};
 	zfs_handle_t *nzhp;
 	int ret;
 
@@ -306,12 +306,11 @@ int
 zfs_iter_snapspec(zfs_handle_t *fs_zhp, const char *spec_orig,
     zfs_iter_f func, void *arg)
 {
-	char buf[ZFS_MAXNAMELEN];
-	char *comma_separated, *cp;
+	char *buf, *comma_separated, *cp;
 	int err = 0;
 	int ret = 0;
 
-	(void) strlcpy(buf, spec_orig, sizeof (buf));
+	buf = zfs_strdup(fs_zhp->zfs_hdl, spec_orig);
 	cp = buf;
 
 	while ((comma_separated = strsep(&cp, ",")) != NULL) {
@@ -369,6 +368,7 @@ zfs_iter_snapspec(zfs_handle_t *fs_zhp, const char *spec_orig,
 		}
 	}
 
+	free(buf);
 	return (ret);
 }
 

lib/libzfs/libzfs_pool.c

@@ -34,6 +34,7 @@
 #include <stdlib.h>
 #include <strings.h>
 #include <unistd.h>
+#include <libgen.h>
 #include <zone.h>
 #include <sys/stat.h>
 #include <sys/efi_partition.h>
@@ -63,7 +64,7 @@ typedef struct prop_flags {
 static int
 zpool_get_all_props(zpool_handle_t *zhp)
 {
-	zfs_cmd_t zc = { "\0", "\0", "\0", "\0", 0 };
+	zfs_cmd_t zc = {"\0", 0, 0, 0, 0, 0, 0, 0, "\0", "\0", "\0"};
 	libzfs_handle_t *hdl = zhp->zpool_hdl;
 
 	(void) strlcpy(zc.zc_name, zhp->zpool_name, sizeof (zc.zc_name));
@@ -691,7 +692,7 @@ error:
 int
 zpool_set_prop(zpool_handle_t *zhp, const char *propname, const char *propval)
 {
-	zfs_cmd_t zc = { "\0", "\0", "\0", "\0", 0 };
+	zfs_cmd_t zc = {"\0", 0, 0, 0, 0, 0, 0, 0, "\0", "\0", "\0"};
 	int ret = -1;
 	char errbuf[1024];
 	nvlist_t *nvl = NULL;
@@ -1140,7 +1141,7 @@ int
 zpool_create(libzfs_handle_t *hdl, const char *pool, nvlist_t *nvroot,
     nvlist_t *props, nvlist_t *fsprops)
 {
-	zfs_cmd_t zc = { "\0", "\0", "\0", "\0", 0 };
+	zfs_cmd_t zc = {"\0", 0, 0, 0, 0, 0, 0, 0, "\0", "\0", "\0"};
 	nvlist_t *zc_fsprops = NULL;
 	nvlist_t *zc_props = NULL;
 	char msg[1024];
@@ -1272,9 +1273,9 @@ create_failed:
  * datasets left in the pool.
  */
 int
-zpool_destroy(zpool_handle_t *zhp)
+zpool_destroy(zpool_handle_t *zhp, const char *log_str)
 {
-	zfs_cmd_t zc = { "\0", "\0", "\0", "\0", 0 };
+	zfs_cmd_t zc = {"\0", 0, 0, 0, 0, 0, 0, 0, "\0", "\0", "\0"};
 	zfs_handle_t *zfp = NULL;
 	libzfs_handle_t *hdl = zhp->zpool_hdl;
 	char msg[1024];
@@ -1284,6 +1285,7 @@ zpool_destroy(zpool_handle_t *zhp)
 		return (-1);
 
 	(void) strlcpy(zc.zc_name, zhp->zpool_name, sizeof (zc.zc_name));
+	zc.zc_history = (uint64_t)(uintptr_t)log_str;
 
 	if (zfs_ioctl(hdl, ZFS_IOC_POOL_DESTROY, &zc) != 0) {
 		(void) snprintf(msg, sizeof (msg), dgettext(TEXT_DOMAIN,
@@ -1317,7 +1319,7 @@ zpool_destroy(zpool_handle_t *zhp)
 int
 zpool_add(zpool_handle_t *zhp, nvlist_t *nvroot)
 {
-	zfs_cmd_t zc = { "\0", "\0", "\0", "\0", 0 };
+	zfs_cmd_t zc = {"\0", 0, 0, 0, 0, 0, 0, 0, "\0", "\0", "\0"};
 	int ret;
 	libzfs_handle_t *hdl = zhp->zpool_hdl;
 	char msg[1024];
@@ -1440,10 +1442,11 @@ zpool_add(zpool_handle_t *zhp, nvlist_t *nvroot)
  * Exports the pool from the system.  The caller must ensure that there are no
  * mounted datasets in the pool.
  */
-int
-zpool_export_common(zpool_handle_t *zhp, boolean_t force, boolean_t hardforce)
+static int
+zpool_export_common(zpool_handle_t *zhp, boolean_t force, boolean_t hardforce,
+    const char *log_str)
 {
-	zfs_cmd_t zc = { "\0", "\0", "\0", "\0", 0 };
+	zfs_cmd_t zc = {"\0", 0, 0, 0, 0, 0, 0, 0, "\0", "\0", "\0"};
 	char msg[1024];
 
 	(void) snprintf(msg, sizeof (msg), dgettext(TEXT_DOMAIN,
@@ -1452,6 +1455,7 @@ zpool_export_common(zpool_handle_t *zhp, boolean_t force, boolean_t hardforce)
 	(void) strlcpy(zc.zc_name, zhp->zpool_name, sizeof (zc.zc_name));
 	zc.zc_cookie = force;
 	zc.zc_guid = hardforce;
+	zc.zc_history = (uint64_t)(uintptr_t)log_str;
 
 	if (zfs_ioctl(zhp->zpool_hdl, ZFS_IOC_POOL_EXPORT, &zc) != 0) {
 		switch (errno) {
@@ -1473,15 +1477,15 @@ zpool_export_common(zpool_handle_t *zhp, boolean_t force, boolean_t hardforce)
 }
 
 int
-zpool_export(zpool_handle_t *zhp, boolean_t force)
+zpool_export(zpool_handle_t *zhp, boolean_t force, const char *log_str)
 {
-	return (zpool_export_common(zhp, force, B_FALSE));
+	return (zpool_export_common(zhp, force, B_FALSE, log_str));
 }
 
 int
-zpool_export_force(zpool_handle_t *zhp)
+zpool_export_force(zpool_handle_t *zhp, const char *log_str)
 {
-	return (zpool_export_common(zhp, B_TRUE, B_TRUE));
+	return (zpool_export_common(zhp, B_TRUE, B_TRUE, log_str));
 }
 
 static void
@@ -1717,7 +1721,7 @@ int
 zpool_import_props(libzfs_handle_t *hdl, nvlist_t *config, const char *newname,
     nvlist_t *props, int flags)
 {
-	zfs_cmd_t zc = { "\0", "\0", "\0", "\0", 0 };
+	zfs_cmd_t zc = {"\0", 0, 0, 0, 0, 0, 0, 0, "\0", "\0", "\0"};
 	zpool_rewind_policy_t policy;
 	nvlist_t *nv = NULL;
 	nvlist_t *nvinfo = NULL;
@@ -1909,7 +1913,7 @@ zpool_import_props(libzfs_handle_t *hdl, nvlist_t *config, const char *newname,
 int
 zpool_scan(zpool_handle_t *zhp, pool_scan_func_t func)
 {
-	zfs_cmd_t zc = { "\0", "\0", "\0", "\0", 0 };
+	zfs_cmd_t zc = {"\0", 0, 0, 0, 0, 0, 0, 0, "\0", "\0", "\0"};
 	char msg[1024];
 	libzfs_handle_t *hdl = zhp->zpool_hdl;
 
@@ -2385,7 +2389,7 @@ int
 zpool_vdev_online(zpool_handle_t *zhp, const char *path, int flags,
     vdev_state_t *newstate)
 {
-	zfs_cmd_t zc = { "\0", "\0", "\0", "\0", 0 };
+	zfs_cmd_t zc = {"\0", 0, 0, 0, 0, 0, 0, 0, "\0", "\0", "\0"};
 	char msg[1024];
 	nvlist_t *tgt;
 	boolean_t avail_spare, l2cache, islog;
@@ -2469,7 +2473,7 @@ zpool_vdev_online(zpool_handle_t *zhp, const char *path, int flags,
 int
 zpool_vdev_offline(zpool_handle_t *zhp, const char *path, boolean_t istmp)
 {
-	zfs_cmd_t zc = { "\0", "\0", "\0", "\0", 0 };
+	zfs_cmd_t zc = {"\0", 0, 0, 0, 0, 0, 0, 0, "\0", "\0", "\0"};
 	char msg[1024];
 	nvlist_t *tgt;
 	boolean_t avail_spare, l2cache;
@@ -2519,7 +2523,7 @@ zpool_vdev_offline(zpool_handle_t *zhp, const char *path, boolean_t istmp)
 int
 zpool_vdev_fault(zpool_handle_t *zhp, uint64_t guid, vdev_aux_t aux)
 {
-	zfs_cmd_t zc = { "\0", "\0", "\0", "\0", 0 };
+	zfs_cmd_t zc = {"\0", 0, 0, 0, 0, 0, 0, 0, "\0", "\0", "\0"};
 	char msg[1024];
 	libzfs_handle_t *hdl = zhp->zpool_hdl;
 
@@ -2554,7 +2558,7 @@ zpool_vdev_fault(zpool_handle_t *zhp, uint64_t guid, vdev_aux_t aux)
 int
 zpool_vdev_degrade(zpool_handle_t *zhp, uint64_t guid, vdev_aux_t aux)
 {
-	zfs_cmd_t zc = { "\0", "\0", "\0", "\0", 0 };
+	zfs_cmd_t zc = {"\0", 0, 0, 0, 0, 0, 0, 0, "\0", "\0", "\0"};
 	char msg[1024];
 	libzfs_handle_t *hdl = zhp->zpool_hdl;
 
@@ -2608,7 +2612,7 @@ int
 zpool_vdev_attach(zpool_handle_t *zhp,
     const char *old_disk, const char *new_disk, nvlist_t *nvroot, int replacing)
 {
-	zfs_cmd_t zc = { "\0", "\0", "\0", "\0", 0 };
+	zfs_cmd_t zc = {"\0", 0, 0, 0, 0, 0, 0, 0, "\0", "\0", "\0"};
 	char msg[1024];
 	int ret;
 	nvlist_t *tgt;
@@ -2784,7 +2788,7 @@ zpool_vdev_attach(zpool_handle_t *zhp,
 int
 zpool_vdev_detach(zpool_handle_t *zhp, const char *path)
 {
-	zfs_cmd_t zc = { "\0", "\0", "\0", "\0", 0 };
+	zfs_cmd_t zc = {"\0", 0, 0, 0, 0, 0, 0, 0, "\0", "\0", "\0"};
 	char msg[1024];
 	nvlist_t *tgt;
 	boolean_t avail_spare, l2cache;
@@ -2882,7 +2886,7 @@ int
 zpool_vdev_split(zpool_handle_t *zhp, char *newname, nvlist_t **newroot,
     nvlist_t *props, splitflags_t flags)
 {
-	zfs_cmd_t zc = { "\0", "\0", "\0", "\0", 0 };
+	zfs_cmd_t zc = {"\0", 0, 0, 0, 0, 0, 0, 0, "\0", "\0", "\0"};
 	char msg[1024];
 	nvlist_t *tree, *config, **child, **newchild, *newconfig = NULL;
 	nvlist_t **varray = NULL, *zc_props = NULL;
@@ -3093,7 +3097,7 @@ out:
 int
 zpool_vdev_remove(zpool_handle_t *zhp, const char *path)
 {
-	zfs_cmd_t zc = { "\0", "\0", "\0", "\0", 0 };
+	zfs_cmd_t zc = {"\0", 0, 0, 0, 0, 0, 0, 0, "\0", "\0", "\0"};
 	char msg[1024];
 	nvlist_t *tgt;
 	boolean_t avail_spare, l2cache, islog;
@@ -3138,7 +3142,7 @@ zpool_vdev_remove(zpool_handle_t *zhp, const char *path)
 int
 zpool_clear(zpool_handle_t *zhp, const char *path, nvlist_t *rewindnvl)
 {
-	zfs_cmd_t zc = { "\0", "\0", "\0", "\0", 0 };
+	zfs_cmd_t zc = {"\0", 0, 0, 0, 0, 0, 0, 0, "\0", "\0", "\0"};
 	char msg[1024];
 	nvlist_t *tgt;
 	zpool_rewind_policy_t policy;
@@ -3214,7 +3218,7 @@ zpool_clear(zpool_handle_t *zhp, const char *path, nvlist_t *rewindnvl)
 int
 zpool_vdev_clear(zpool_handle_t *zhp, uint64_t guid)
 {
-	zfs_cmd_t zc = { "\0", "\0", "\0", "\0", 0 };
+	zfs_cmd_t zc = {"\0", 0, 0, 0, 0, 0, 0, 0, "\0", "\0", "\0"};
 	char msg[1024];
 	libzfs_handle_t *hdl = zhp->zpool_hdl;
 
@@ -3240,7 +3244,7 @@ zpool_reguid(zpool_handle_t *zhp)
 {
 	char msg[1024];
 	libzfs_handle_t *hdl = zhp->zpool_hdl;
-	zfs_cmd_t zc = { "\0", "\0", "\0", "\0", 0 };
+	zfs_cmd_t zc = {"\0", 0, 0, 0, 0, 0, 0, 0, "\0", "\0", "\0"};
 
 	(void) snprintf(msg, sizeof (msg),
 	    dgettext(TEXT_DOMAIN, "cannot reguid '%s'"), zhp->zpool_name);
@@ -3258,7 +3262,7 @@ zpool_reguid(zpool_handle_t *zhp)
 int
 zpool_reopen(zpool_handle_t *zhp)
 {
-	zfs_cmd_t zc = { "\0", "\0", "\0", "\0", 0 };
+	zfs_cmd_t zc = {"\0", 0, 0, 0, 0, 0, 0, 0, "\0", "\0", "\0"};
 	char msg[1024];
 	libzfs_handle_t *hdl = zhp->zpool_hdl;
 
@@ -3338,7 +3342,7 @@ path_to_devid(const char *path)
 static void
 set_path(zpool_handle_t *zhp, nvlist_t *nv, const char *path)
 {
-	zfs_cmd_t zc = { "\0", "\0", "\0", "\0", 0 };
+	zfs_cmd_t zc = {"\0", 0, 0, 0, 0, 0, 0, 0, "\0", "\0", "\0"};
 
 	(void) strncpy(zc.zc_name, zhp->zpool_name, sizeof (zc.zc_name));
 	(void) strncpy(zc.zc_value, path, sizeof (zc.zc_value));
@@ -3513,7 +3517,7 @@ zbookmark_compare(const void *a, const void *b)
 int
 zpool_get_errlog(zpool_handle_t *zhp, nvlist_t **nverrlistp)
 {
-	zfs_cmd_t zc = { "\0", "\0", "\0", "\0", 0 };
+	zfs_cmd_t zc = {"\0", 0, 0, 0, 0, 0, 0, 0, "\0", "\0", "\0"};
 	uint64_t count;
 	zbookmark_t *zb = NULL;
 	int i;
@@ -3609,7 +3613,7 @@ nomem:
 int
 zpool_upgrade(zpool_handle_t *zhp, uint64_t new_version)
 {
-	zfs_cmd_t zc = { "\0", "\0", "\0", "\0", 0 };
+	zfs_cmd_t zc = {"\0", 0, 0, 0, 0, 0, 0, 0, "\0", "\0", "\0"};
 	libzfs_handle_t *hdl = zhp->zpool_hdl;
 
 	(void) strcpy(zc.zc_name, zhp->zpool_name);
@@ -3623,40 +3627,32 @@ zpool_upgrade(zpool_handle_t *zhp, uint64_t new_version)
 }
 
 void
-zpool_set_history_str(const char *subcommand, int argc, char **argv,
-    char *history_str)
+zfs_save_arguments(int argc, char **argv, char *string, int len)
 {
 	int i;
 
-	(void) strlcpy(history_str, subcommand, HIS_MAX_RECORD_LEN);
+	(void) strlcpy(string, basename(argv[0]), len);
 	for (i = 1; i < argc; i++) {
-		if (strlen(history_str) + 1 + strlen(argv[i]) >
-		    HIS_MAX_RECORD_LEN)
-			break;
-		(void) strlcat(history_str, " ", HIS_MAX_RECORD_LEN);
-		(void) strlcat(history_str, argv[i], HIS_MAX_RECORD_LEN);
+		(void) strlcat(string, " ", len);
+		(void) strlcat(string, argv[i], len);
 	}
 }
 
-/*
- * Stage command history for logging.
- */
 int
-zpool_stage_history(libzfs_handle_t *hdl, const char *history_str)
+zpool_log_history(libzfs_handle_t *hdl, const char *message)
 {
-	if (history_str == NULL)
-		return (EINVAL);
+	zfs_cmd_t zc = {"\0", 0, 0, 0, 0, 0, 0, 0, "\0", "\0", "\0"};
+	nvlist_t *args;
+	int err;
 
-	if (strlen(history_str) > HIS_MAX_RECORD_LEN)
-		return (EINVAL);
-
-	if (hdl->libzfs_log_str != NULL)
-		free(hdl->libzfs_log_str);
-
-	if ((hdl->libzfs_log_str = strdup(history_str)) == NULL)
-		return (no_memory(hdl));
-
-	return (0);
+	args = fnvlist_alloc();
+	fnvlist_add_string(args, "message", message);
+	err = zcmd_write_src_nvlist(hdl, &zc, args);
+	if (err == 0)
+		err = ioctl(hdl->libzfs_fd, ZFS_IOC_LOG_HISTORY, &zc);
+	nvlist_free(args);
+	zcmd_free_nvlists(&zc);
+	return (err);
 }
 
 /*
@@ -3671,7 +3667,7 @@ zpool_stage_history(libzfs_handle_t *hdl, const char *history_str)
 static int
 get_history(zpool_handle_t *zhp, char *buf, uint64_t *off, uint64_t *len)
 {
-	zfs_cmd_t zc = { "\0", "\0", "\0", "\0", 0 };
+	zfs_cmd_t zc = {"\0", 0, 0, 0, 0, 0, 0, 0, "\0", "\0", "\0"};
 	libzfs_handle_t *hdl = zhp->zpool_hdl;
 
 	(void) strlcpy(zc.zc_name, zhp->zpool_name, sizeof (zc.zc_name));
@@ -3808,7 +3804,7 @@ int
 zpool_events_next(libzfs_handle_t *hdl, nvlist_t **nvp,
     int *dropped, int block, int cleanup_fd)
 {
-	zfs_cmd_t zc = { "\0", "\0", "\0", "\0", 0 };
+	zfs_cmd_t zc = {"\0", 0, 0, 0, 0, 0, 0, 0, "\0", "\0", "\0"};
 	int error = 0;
 
 	*nvp = NULL;
@@ -3867,7 +3863,7 @@ out:
 int
 zpool_events_clear(libzfs_handle_t *hdl, int *count)
 {
-	zfs_cmd_t zc = { "\0", "\0", "\0", "\0", 0 };
+	zfs_cmd_t zc = {"\0", 0, 0, 0, 0, 0, 0, 0, "\0", "\0", "\0"};
 	char msg[1024];
 
 	(void) snprintf(msg, sizeof (msg), dgettext(TEXT_DOMAIN,
@@ -3886,7 +3882,7 @@ void
 zpool_obj_to_path(zpool_handle_t *zhp, uint64_t dsobj, uint64_t obj,
     char *pathname, size_t len)
 {
-	zfs_cmd_t zc = { "\0", "\0", "\0", "\0", 0 };
+	zfs_cmd_t zc = {"\0", 0, 0, 0, 0, 0, 0, 0, "\0", "\0", "\0"};
 	boolean_t mounted = B_FALSE;
 	char *mntpnt = NULL;
 	char dsname[MAXNAMELEN];

lib/libzfs/libzfs_sendrecv.c

@@ -812,7 +812,7 @@ static int
 estimate_ioctl(zfs_handle_t *zhp, uint64_t fromsnap_obj,
     boolean_t fromorigin, uint64_t *sizep)
 {
-	zfs_cmd_t zc = { "\0", "\0", "\0", "\0", 0 };
+	zfs_cmd_t zc = {"\0", 0, 0, 0, 0, 0, 0, 0, "\0", "\0", "\0"};
 	libzfs_handle_t *hdl = zhp->zfs_hdl;
 
 	assert(zhp->zfs_type == ZFS_TYPE_SNAPSHOT);
@@ -876,7 +876,7 @@ static int
 dump_ioctl(zfs_handle_t *zhp, const char *fromsnap, uint64_t fromsnap_obj,
     boolean_t fromorigin, int outfd, nvlist_t *debugnv)
 {
-	zfs_cmd_t zc = { "\0", "\0", "\0", "\0", 0 };
+	zfs_cmd_t zc = {"\0", 0, 0, 0, 0, 0, 0, 0, "\0", "\0", "\0"};
 	libzfs_handle_t *hdl = zhp->zfs_hdl;
 	nvlist_t *thisdbg;
 
@@ -992,7 +992,7 @@ send_progress_thread(void *arg)
 {
 	progress_arg_t *pa = arg;
 
-	zfs_cmd_t zc = { "\0", "\0", "\0", "\0", 0 };
+	zfs_cmd_t zc = {"\0", 0, 0, 0, 0, 0, 0, 0, "\0", "\0", "\0"};
 	zfs_handle_t *zhp = pa->pa_zhp;
 	libzfs_handle_t *hdl = zhp->zfs_hdl;
 	unsigned long long bytes;
@@ -1195,7 +1195,7 @@ dump_filesystem(zfs_handle_t *zhp, void *arg)
 	int rv = 0;
 	send_dump_data_t *sdd = arg;
 	boolean_t missingfrom = B_FALSE;
-	zfs_cmd_t zc = { "\0", "\0", "\0", "\0", 0 };
+	zfs_cmd_t zc = {"\0", 0, 0, 0, 0, 0, 0, 0, "\0", "\0", "\0"};
 
 	(void) snprintf(zc.zc_name, sizeof (zc.zc_name), "%s@%s",
 	    zhp->zfs_name, sdd->tosnap);
@@ -1683,7 +1683,7 @@ recv_rename(libzfs_handle_t *hdl, const char *name, const char *tryname,
     int baselen, char *newname, recvflags_t *flags)
 {
 	static int seq;
-	zfs_cmd_t zc = { "\0", "\0", "\0", "\0", 0 };
+	zfs_cmd_t zc = {"\0", 0, 0, 0, 0, 0, 0, 0, "\0", "\0", "\0"};
 	int err;
 	prop_changelist_t *clp;
 	zfs_handle_t *zhp;
@@ -1756,7 +1756,7 @@ static int
 recv_destroy(libzfs_handle_t *hdl, const char *name, int baselen,
     char *newname, recvflags_t *flags)
 {
-	zfs_cmd_t zc = { "\0", "\0", "\0", "\0", 0 };
+	zfs_cmd_t zc = {"\0", 0, 0, 0, 0, 0, 0, 0, "\0", "\0", "\0"};
 	int err = 0;
 	prop_changelist_t *clp;
 	zfs_handle_t *zhp;
@@ -2015,7 +2015,7 @@ again:
 			    stream_originguid, originguid)) {
 			case 1: {
 				/* promote it! */
-				zfs_cmd_t zc = { "\0", "\0", "\0", "\0", 0 };
+				zfs_cmd_t zc = {"\0", 0, 0, 0, 0, 0, 0, 0, "\0", "\0", "\0"};
 				nvlist_t *origin_nvfs;
 				char *origin_fsname;
 
@@ -2087,7 +2087,7 @@ again:
 			if (0 == nvlist_lookup_nvlist(stream_nvfs, "snapprops",
 			    &props) && 0 == nvlist_lookup_nvlist(props,
 			    stream_snapname, &props)) {
-				zfs_cmd_t zc = { "\0", "\0", "\0", "\0", 0 };
+				zfs_cmd_t zc = {"\0", 0, 0, 0, 0, 0, 0, 0, "\0", "\0", "\0"};
 
 				zc.zc_cookie = B_TRUE; /* received */
 				(void) snprintf(zc.zc_name, sizeof (zc.zc_name),
@@ -2518,7 +2518,7 @@ zfs_receive_one(libzfs_handle_t *hdl, int infd, const char *tosnap,
     nvlist_t *stream_nv, avl_tree_t *stream_avl, char **top_zfs, int cleanup_fd,
     uint64_t *action_handlep)
 {
-	zfs_cmd_t zc = { "\0", "\0", "\0", "\0", 0 };
+	zfs_cmd_t zc = {"\0", 0, 0, 0, 0, 0, 0, 0, "\0", "\0", "\0"};
 	time_t begin_time;
 	int ioctl_err, ioctl_errno, err;
 	char *cp;
@@ -2892,7 +2892,7 @@ zfs_receive_one(libzfs_handle_t *hdl, int infd, const char *tosnap,
 	zcmd_free_nvlists(&zc);
 
 	if (err == 0 && snapprops_nvlist) {
-		zfs_cmd_t zc2 = { "\0", "\0", "\0", "\0", 0 };
+		zfs_cmd_t zc2 = {"\0", 0, 0, 0, 0, 0, 0, 0, "\0", "\0", "\0"};
 
 		(void) strcpy(zc2.zc_name, zc.zc_value);
 		zc2.zc_cookie = B_TRUE; /* received */

lib/libzfs/libzfs_util.c

@@ -45,6 +45,7 @@
 #include <wait.h>
 
 #include <libzfs.h>
+#include <libzfs_core.h>
 
 #include "libzfs_impl.h"
 #include "zfs_prop.h"
@@ -712,6 +713,14 @@ libzfs_init(void)
 
 	hdl->libzfs_sharetab = fopen("/etc/dfs/sharetab", "r");
 
+	if (libzfs_core_init() != 0) {
+		(void) close(hdl->libzfs_fd);
+		(void) fclose(hdl->libzfs_mnttab);
+		(void) fclose(hdl->libzfs_sharetab);
+		free(hdl);
+		return (NULL);
+	}
+
 	zfs_prop_init();
 	zpool_prop_init();
 	zpool_feature_init();
@@ -733,12 +742,11 @@ libzfs_fini(libzfs_handle_t *hdl)
 	if (hdl->libzfs_sharetab)
 		(void) fclose(hdl->libzfs_sharetab);
 	zfs_uninit_libshare(hdl);
-	if (hdl->libzfs_log_str)
-		(void) free(hdl->libzfs_log_str);
 	zpool_free_handles(hdl);
 	libzfs_fru_clear(hdl, B_TRUE);
 	namespace_clear(hdl);
 	libzfs_mnttab_fini(hdl);
+	libzfs_core_fini();
 	free(hdl);
 }
 
@@ -1061,17 +1069,7 @@ zcmd_read_dst_nvlist(libzfs_handle_t *hdl, zfs_cmd_t *zc, nvlist_t **nvlp)
 int
 zfs_ioctl(libzfs_handle_t *hdl, int request, zfs_cmd_t *zc)
 {
-	int error;
-
-	zc->zc_history = (uint64_t)(uintptr_t)hdl->libzfs_log_str;
-	error = ioctl(hdl->libzfs_fd, request, zc);
-	if (hdl->libzfs_log_str) {
-		free(hdl->libzfs_log_str);
-		hdl->libzfs_log_str = NULL;
-	}
-	zc->zc_history = 0;
-
-	return (error);
+	return (ioctl(hdl->libzfs_fd, request, zc));
 }
 
 /*

lib/libzfs_core/Makefile.am

@@ -0,0 +1,15 @@
+include $(top_srcdir)/config/Rules.am
+
+DEFAULT_INCLUDES += \
+	-I$(top_srcdir)/include \
+	-I$(top_srcdir)/lib/libspl/include
+
+lib_LTLIBRARIES = libzfs_core.la
+
+libzfs_core_la_SOURCES = \
+	$(top_srcdir)/lib/libzfs_core/libzfs_core.c
+
+libzfs_core_la_LIBADD = \
+	$(top_builddir)/lib/libnvpair/libnvpair.la
+
+libzfs_core_la_LDFLAGS = -pthread -version-info 1:1:0

lib/libzfs_core/libzfs_core.c

@@ -0,0 +1,477 @@
+/*
+ * 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 (c) 2012 by Delphix. All rights reserved.
+ */
+
+/*
+ * LibZFS_Core (lzc) is intended to replace most functionality in libzfs.
+ * It has the following characteristics:
+ *
+ *  - Thread Safe.  libzfs_core is accessible concurrently from multiple
+ *  threads.  This is accomplished primarily by avoiding global data
+ *  (e.g. caching).  Since it's thread-safe, there is no reason for a
+ *  process to have multiple libzfs "instances".  Therefore, we store
+ *  our few pieces of data (e.g. the file descriptor) in global
+ *  variables.  The fd is reference-counted so that the libzfs_core
+ *  library can be "initialized" multiple times (e.g. by different
+ *  consumers within the same process).
+ *
+ *  - Committed Interface.  The libzfs_core interface will be committed,
+ *  therefore consumers can compile against it and be confident that
+ *  their code will continue to work on future releases of this code.
+ *  Currently, the interface is Evolving (not Committed), but we intend
+ *  to commit to it once it is more complete and we determine that it
+ *  meets the needs of all consumers.
+ *
+ *  - Programatic Error Handling.  libzfs_core communicates errors with
+ *  defined error numbers, and doesn't print anything to stdout/stderr.
+ *
+ *  - Thin Layer.  libzfs_core is a thin layer, marshaling arguments
+ *  to/from the kernel ioctls.  There is generally a 1:1 correspondence
+ *  between libzfs_core functions and ioctls to /dev/zfs.
+ *
+ *  - Clear Atomicity.  Because libzfs_core functions are generally 1:1
+ *  with kernel ioctls, and kernel ioctls are general atomic, each
+ *  libzfs_core function is atomic.  For example, creating multiple
+ *  snapshots with a single call to lzc_snapshot() is atomic -- it
+ *  can't fail with only some of the requested snapshots created, even
+ *  in the event of power loss or system crash.
+ *
+ *  - Continued libzfs Support.  Some higher-level operations (e.g.
+ *  support for "zfs send -R") are too complicated to fit the scope of
+ *  libzfs_core.  This functionality will continue to live in libzfs.
+ *  Where appropriate, libzfs will use the underlying atomic operations
+ *  of libzfs_core.  For example, libzfs may implement "zfs send -R |
+ *  zfs receive" by using individual "send one snapshot", rename,
+ *  destroy, and "receive one snapshot" operations in libzfs_core.
+ *  /sbin/zfs and /zbin/zpool will link with both libzfs and
+ *  libzfs_core.  Other consumers should aim to use only libzfs_core,
+ *  since that will be the supported, stable interface going forwards.
+ */
+
+#include <libzfs_core.h>
+#include <ctype.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <pthread.h>
+#include <sys/nvpair.h>
+#include <sys/param.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/zfs_ioctl.h>
+
+static int g_fd;
+static pthread_mutex_t g_lock = PTHREAD_MUTEX_INITIALIZER;
+static int g_refcount;
+
+int
+libzfs_core_init(void)
+{
+	(void) pthread_mutex_lock(&g_lock);
+	if (g_refcount == 0) {
+		g_fd = open("/dev/zfs", O_RDWR);
+		if (g_fd < 0) {
+			(void) pthread_mutex_unlock(&g_lock);
+			return (errno);
+		}
+	}
+	g_refcount++;
+	(void) pthread_mutex_unlock(&g_lock);
+	return (0);
+}
+
+void
+libzfs_core_fini(void)
+{
+	(void) pthread_mutex_lock(&g_lock);
+	ASSERT3S(g_refcount, >, 0);
+	g_refcount--;
+	if (g_refcount == 0)
+		(void) close(g_fd);
+	(void) pthread_mutex_unlock(&g_lock);
+}
+
+static int
+lzc_ioctl(zfs_ioc_t ioc, const char *name,
+    nvlist_t *source, nvlist_t **resultp)
+{
+	zfs_cmd_t zc = {"\0", 0, 0, 0, 0, 0, 0, 0, "\0", "\0", "\0"};
+	int error = 0;
+	char *packed;
+	size_t size;
+
+	ASSERT3S(g_refcount, >, 0);
+
+	(void) strlcpy(zc.zc_name, name, sizeof (zc.zc_name));
+
+	packed = fnvlist_pack(source, &size);
+	zc.zc_nvlist_src = (uint64_t)(uintptr_t)packed;
+	zc.zc_nvlist_src_size = size;
+
+	if (resultp != NULL) {
+		zc.zc_nvlist_dst_size = MAX(size * 2, 128 * 1024);
+		zc.zc_nvlist_dst = (uint64_t)(uintptr_t)
+		    malloc(zc.zc_nvlist_dst_size);
+		if (zc.zc_nvlist_dst == (uint64_t)0) {
+			error = ENOMEM;
+			goto out;
+		}
+	}
+
+	while (ioctl(g_fd, ioc, &zc) != 0) {
+		if (errno == ENOMEM && resultp != NULL) {
+			free((void *)(uintptr_t)zc.zc_nvlist_dst);
+			zc.zc_nvlist_dst_size *= 2;
+			zc.zc_nvlist_dst = (uint64_t)(uintptr_t)
+			    malloc(zc.zc_nvlist_dst_size);
+			if (zc.zc_nvlist_dst == (uint64_t)0) {
+				error = ENOMEM;
+				goto out;
+			}
+		} else {
+			error = errno;
+			break;
+		}
+	}
+	if (zc.zc_nvlist_dst_filled) {
+		*resultp = fnvlist_unpack((void *)(uintptr_t)zc.zc_nvlist_dst,
+		    zc.zc_nvlist_dst_size);
+	} else if (resultp != NULL) {
+		*resultp = NULL;
+	}
+
+out:
+	fnvlist_pack_free(packed, size);
+	free((void *)(uintptr_t)zc.zc_nvlist_dst);
+	return (error);
+}
+
+int
+lzc_create(const char *fsname, dmu_objset_type_t type, nvlist_t *props)
+{
+	int error;
+	nvlist_t *args = fnvlist_alloc();
+	fnvlist_add_int32(args, "type", type);
+	if (props != NULL)
+		fnvlist_add_nvlist(args, "props", props);
+	error = lzc_ioctl(ZFS_IOC_CREATE, fsname, args, NULL);
+	nvlist_free(args);
+	return (error);
+}
+
+int
+lzc_clone(const char *fsname, const char *origin,
+    nvlist_t *props)
+{
+	int error;
+	nvlist_t *args = fnvlist_alloc();
+	fnvlist_add_string(args, "origin", origin);
+	if (props != NULL)
+		fnvlist_add_nvlist(args, "props", props);
+	error = lzc_ioctl(ZFS_IOC_CLONE, fsname, args, NULL);
+	nvlist_free(args);
+	return (error);
+}
+
+/*
+ * Creates snapshots.
+ *
+ * The keys in the snaps nvlist are the snapshots to be created.
+ * They must all be in the same pool.
+ *
+ * The props nvlist is properties to set.  Currently only user properties
+ * are supported.  { user:prop_name -> string value }
+ *
+ * The returned results nvlist will have an entry for each snapshot that failed.
+ * The value will be the (int32) error code.
+ *
+ * The return value will be 0 if all snapshots were created, otherwise it will
+ * be the errno of a (undetermined) snapshot that failed.
+ */
+int
+lzc_snapshot(nvlist_t *snaps, nvlist_t *props, nvlist_t **errlist)
+{
+	nvpair_t *elem;
+	nvlist_t *args;
+	int error;
+	char pool[MAXNAMELEN];
+
+	*errlist = NULL;
+
+	/* determine the pool name */
+	elem = nvlist_next_nvpair(snaps, NULL);
+	if (elem == NULL)
+		return (0);
+	(void) strlcpy(pool, nvpair_name(elem), sizeof (pool));
+	pool[strcspn(pool, "/@")] = '\0';
+
+	args = fnvlist_alloc();
+	fnvlist_add_nvlist(args, "snaps", snaps);
+	if (props != NULL)
+		fnvlist_add_nvlist(args, "props", props);
+
+	error = lzc_ioctl(ZFS_IOC_SNAPSHOT, pool, args, errlist);
+	nvlist_free(args);
+
+	return (error);
+}
+
+/*
+ * Destroys snapshots.
+ *
+ * The keys in the snaps nvlist are the snapshots to be destroyed.
+ * They must all be in the same pool.
+ *
+ * Snapshots that do not exist will be silently ignored.
+ *
+ * If 'defer' is not set, and a snapshot has user holds or clones, the
+ * destroy operation will fail and none of the snapshots will be
+ * destroyed.
+ *
+ * If 'defer' is set, and a snapshot has user holds or clones, it will be
+ * marked for deferred destruction, and will be destroyed when the last hold
+ * or clone is removed/destroyed.
+ *
+ * The return value will be 0 if all snapshots were destroyed (or marked for
+ * later destruction if 'defer' is set) or didn't exist to begin with.
+ *
+ * Otherwise the return value will be the errno of a (undetermined) snapshot
+ * that failed, no snapshots will be destroyed, and the errlist will have an
+ * entry for each snapshot that failed.  The value in the errlist will be
+ * the (int32) error code.
+ */
+int
+lzc_destroy_snaps(nvlist_t *snaps, boolean_t defer, nvlist_t **errlist)
+{
+	nvpair_t *elem;
+	nvlist_t *args;
+	int error;
+	char pool[MAXNAMELEN];
+
+	/* determine the pool name */
+	elem = nvlist_next_nvpair(snaps, NULL);
+	if (elem == NULL)
+		return (0);
+	(void) strlcpy(pool, nvpair_name(elem), sizeof (pool));
+	pool[strcspn(pool, "/@")] = '\0';
+
+	args = fnvlist_alloc();
+	fnvlist_add_nvlist(args, "snaps", snaps);
+	if (defer)
+		fnvlist_add_boolean(args, "defer");
+
+	error = lzc_ioctl(ZFS_IOC_DESTROY_SNAPS, pool, args, errlist);
+	nvlist_free(args);
+
+	return (error);
+
+}
+
+int
+lzc_snaprange_space(const char *firstsnap, const char *lastsnap,
+    uint64_t *usedp)
+{
+	nvlist_t *args;
+	nvlist_t *result;
+	int err;
+	char fs[MAXNAMELEN];
+	char *atp;
+
+	/* determine the fs name */
+	(void) strlcpy(fs, firstsnap, sizeof (fs));
+	atp = strchr(fs, '@');
+	if (atp == NULL)
+		return (EINVAL);
+	*atp = '\0';
+
+	args = fnvlist_alloc();
+	fnvlist_add_string(args, "firstsnap", firstsnap);
+
+	err = lzc_ioctl(ZFS_IOC_SPACE_SNAPS, lastsnap, args, &result);
+	nvlist_free(args);
+	if (err == 0)
+		*usedp = fnvlist_lookup_uint64(result, "used");
+	fnvlist_free(result);
+
+	return (err);
+}
+
+boolean_t
+lzc_exists(const char *dataset)
+{
+	/*
+	 * The objset_stats ioctl is still legacy, so we need to construct our
+	 * own zfs_cmd_t rather than using zfsc_ioctl().
+	 */
+	zfs_cmd_t zc = {"\0", 0, 0, 0, 0, 0, 0, 0, "\0", "\0", "\0"};
+
+	(void) strlcpy(zc.zc_name, dataset, sizeof (zc.zc_name));
+	return (ioctl(g_fd, ZFS_IOC_OBJSET_STATS, &zc) == 0);
+}
+
+/*
+ * If fromsnap is NULL, a full (non-incremental) stream will be sent.
+ */
+int
+lzc_send(const char *snapname, const char *fromsnap, int fd)
+{
+	nvlist_t *args;
+	int err;
+
+	args = fnvlist_alloc();
+	fnvlist_add_int32(args, "fd", fd);
+	if (fromsnap != NULL)
+		fnvlist_add_string(args, "fromsnap", fromsnap);
+	err = lzc_ioctl(ZFS_IOC_SEND_NEW, snapname, args, NULL);
+	nvlist_free(args);
+	return (err);
+}
+
+/*
+ * If fromsnap is NULL, a full (non-incremental) stream will be estimated.
+ */
+int
+lzc_send_space(const char *snapname, const char *fromsnap, uint64_t *spacep)
+{
+	nvlist_t *args;
+	nvlist_t *result;
+	int err;
+
+	args = fnvlist_alloc();
+	if (fromsnap != NULL)
+		fnvlist_add_string(args, "fromsnap", fromsnap);
+	err = lzc_ioctl(ZFS_IOC_SEND_SPACE, snapname, args, &result);
+	nvlist_free(args);
+	if (err == 0)
+		*spacep = fnvlist_lookup_uint64(result, "space");
+	nvlist_free(result);
+	return (err);
+}
+
+static int
+recv_read(int fd, void *buf, int ilen)
+{
+	char *cp = buf;
+	int rv;
+	int len = ilen;
+
+	do {
+		rv = read(fd, cp, len);
+		cp += rv;
+		len -= rv;
+	} while (rv > 0);
+
+	if (rv < 0 || len != 0)
+		return (EIO);
+
+	return (0);
+}
+
+/*
+ * The simplest receive case: receive from the specified fd, creating the
+ * specified snapshot.  Apply the specified properties a "received" properties
+ * (which can be overridden by locally-set properties).  If the stream is a
+ * clone, its origin snapshot must be specified by 'origin'.  The 'force'
+ * flag will cause the target filesystem to be rolled back or destroyed if
+ * necessary to receive.
+ *
+ * Return 0 on success or an errno on failure.
+ *
+ * Note: this interface does not work on dedup'd streams
+ * (those with DMU_BACKUP_FEATURE_DEDUP).
+ */
+int
+lzc_receive(const char *snapname, nvlist_t *props, const char *origin,
+    boolean_t force, int fd)
+{
+	/*
+	 * The receive ioctl is still legacy, so we need to construct our own
+	 * zfs_cmd_t rather than using zfsc_ioctl().
+	 */
+	zfs_cmd_t zc = {"\0", 0, 0, 0, 0, 0, 0, 0, "\0", "\0", "\0"};
+	char *atp;
+	char *packed = NULL;
+	size_t size;
+	dmu_replay_record_t drr;
+	int error;
+
+	ASSERT3S(g_refcount, >, 0);
+
+	/* zc_name is name of containing filesystem */
+	(void) strlcpy(zc.zc_name, snapname, sizeof (zc.zc_name));
+	atp = strchr(zc.zc_name, '@');
+	if (atp == NULL)
+		return (EINVAL);
+	*atp = '\0';
+
+	/* if the fs does not exist, try its parent. */
+	if (!lzc_exists(zc.zc_name)) {
+		char *slashp = strrchr(zc.zc_name, '/');
+		if (slashp == NULL)
+			return (ENOENT);
+		*slashp = '\0';
+
+	}
+
+	/* zc_value is full name of the snapshot to create */
+	(void) strlcpy(zc.zc_value, snapname, sizeof (zc.zc_value));
+
+	if (props != NULL) {
+		/* zc_nvlist_src is props to set */
+		packed = fnvlist_pack(props, &size);
+		zc.zc_nvlist_src = (uint64_t)(uintptr_t)packed;
+		zc.zc_nvlist_src_size = size;
+	}
+
+	/* zc_string is name of clone origin (if DRR_FLAG_CLONE) */
+	if (origin != NULL)
+		(void) strlcpy(zc.zc_string, origin, sizeof (zc.zc_string));
+
+	/* zc_begin_record is non-byteswapped BEGIN record */
+	error = recv_read(fd, &drr, sizeof (drr));
+	if (error != 0)
+		goto out;
+	zc.zc_begin_record = drr.drr_u.drr_begin;
+
+	/* zc_cookie is fd to read from */
+	zc.zc_cookie = fd;
+
+	/* zc guid is force flag */
+	zc.zc_guid = force;
+
+	/* zc_cleanup_fd is unused */
+	zc.zc_cleanup_fd = -1;
+
+	error = ioctl(g_fd, ZFS_IOC_RECV, &zc);
+	if (error != 0)
+		error = errno;
+
+out:
+	if (packed != NULL)
+		fnvlist_pack_free(packed, size);
+	free((void*)(uintptr_t)zc.zc_nvlist_dst);
+	return (error);
+}

lib/libzpool/kernel.c

@@ -1082,6 +1082,12 @@ crgetuid(cred_t *cr)
 	return (0);
 }
 
+uid_t
+crgetruid(cred_t *cr)
+{
+	return (0);
+}
+
 gid_t
 crgetgid(cred_t *cr)
 {