Fix some ZFS Test Suite issues

* Add 'zfs bookmark' coverage (zfs_bookmark_cliargs)

 * Add OpenZFS 8166 coverage (zpool_scrub_offline_device)

 * Fix "busy" zfs_mount_remount failures

 * Fix bootfs_003_pos, bootfs_004_neg, zdb_005_pos local cleanup

 * Update usage of $KEEP variable, add get_all_pools() function

 * Enable history_008_pos and rsend_019_pos (non-32bit builders)

 * Enable zfs_copies_005_neg, update local cleanup

 * Fix zfs_send_007_pos (large_dnode + OpenZFS 8199)

 * Fix rollback_003_pos (use dataset name, not mountpoint, to unmount)

 * Update default_raidz_setup() to work properly with more than 3 disks

 * Use $TEST_BASE_DIR instead of hardcoded (/var)/tmp for file VDEVs

 * Update usage of /dev/random to /dev/urandom

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: loli10K <ezomori.nozomu@gmail.com>
Issue #6086 
Closes #5658 
Closes #6143 
Closes #6421 
Closes #6627 
Closes #6632

scripts/zfs-tests.sh

@@ -438,15 +438,28 @@ fi
 
 #
 # By default preserve any existing pools
+# NOTE: Since 'zpool list' outputs a newline-delimited list convert $KEEP from
+# space-delimited to newline-delimited.
 #
 if [ -z "${KEEP}" ]; then
-	KEEP=$(sudo "$ZPOOL" list -H -o name)
+	KEEP="$(sudo "$ZPOOL" list -H -o name)"
 	if [ -z "${KEEP}" ]; then
 		KEEP="rpool"
 	fi
+else
+	KEEP="$(echo -e "${KEEP//[[:blank:]]/\n}")"
 fi
 
-__ZFS_POOL_EXCLUDE="$(echo $KEEP | sed ':a;N;s/\n/ /g;ba')"
+#
+# NOTE: The following environment variables are undocumented
+# and should be used for testing purposes only:
+#
+# __ZFS_POOL_EXCLUDE - don't iterate over the pools it lists
+# __ZFS_POOL_RESTRICT - iterate only over the pools it lists
+#
+# See libzfs/libzfs_config.c for more information.
+#
+__ZFS_POOL_EXCLUDE="$(echo "$KEEP" | sed ':a;N;s/\n/ /g;ba')"
 
 . "$STF_SUITE/include/default.cfg"
 
@@ -524,6 +537,7 @@ export STF_TOOLS
 export STF_SUITE
 export STF_PATH
 export DISKS
+export FILEDIR
 export KEEP
 export __ZFS_POOL_EXCLUDE
 export TESTFAIL_CALLBACKS