Update tests/README.md and fix markdown

- there are more options now
- command examples are more readable in code style

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Giuseppe Di Natale <guss80@gmail.com>
Signed-off-by: George Melikov <mail@gmelikov.ru>
Closes #7538

tests/README.md

@@ -82,6 +82,10 @@ The following zfs-tests.sh options are supported:
                 the testing.  When running in this mode certain tests will
                 be skipped which depend on real block devices.
 
+    -c          Only create and populate constrained path
+
+    -I NUM      Number of iterations
+
     -d DIR      Create sparse files for vdevs in the DIR directory.  By
                 default these files are created under /var/tmp/.
 
@@ -89,45 +93,60 @@ The following zfs-tests.sh options are supported:
 
     -r RUNFILE  Run tests in RUNFILE (default: linux.run)
 
+    -t PATH     Run single test at PATH relative to test suite
+
+    -T TAGS     Comma separated list of tags (default: 'functional')
+
+    -u USER     Run single test as USER (default: root)
+
 
 The ZFS Test Suite allows the user to specify a subset of the tests via a
-runfile. The format of the runfile is explained in test-runner(1), and
+runfile or list of tags.
+
+The format of the runfile is explained in test-runner(1), and
 the files that zfs-tests.sh uses are available for reference under
 /usr/share/zfs/runfiles. To specify a custom runfile, use the -r option:
 
     $ /usr/share/zfs/zfs-tests.sh -r my_tests.run
 
+Otherwise user can set needed tags to run only specific tests.
+
 3) Test results
 
 While the ZFS Test Suite is running, one informational line is printed at the
 end of each test, and a results summary is printed at the end of the run. The
 results summary includes the location of the complete logs, which is logged in
-the form /var/tmp/test_results/[ISO 8601 date].  A normal test run launched
+the form `/var/tmp/test_results/[ISO 8601 date]`.  A normal test run launched
 with the `zfs-tests.sh` wrapper script will look something like this:
 
-$ /usr/share/zfs/zfs-tests.sh -v -d /mnt
+    $ /usr/share/zfs/zfs-tests.sh -v -d /tmp/test
 
---- Configuration ---
+    --- Configuration ---
-Runfile:         /usr/share/zfs/runfiles/linux.run
+    Runfile:         /usr/share/zfs/runfiles/linux.run
-STF_TOOLS:       /usr/share/zfs/test-runner
+    STF_TOOLS:       /usr/share/zfs/test-runner
-STF_SUITE:       /usr/share/zfs/zfs-tests
+    STF_SUITE:       /usr/share/zfs/zfs-tests
-FILEDIR:         /mnt
+    STF_PATH:        /var/tmp/constrained_path.G0Sf
-FILES:           /mnt/file-vdev0 /mnt/file-vdev1 /mnt/file-vdev2
+    FILEDIR:         /tmp/test
-LOOPBACKS:       /dev/loop0 /dev/loop1 /dev/loop2 
+    FILES:           /tmp/test/file-vdev0 /tmp/test/file-vdev1 /tmp/test/file-vdev2
-DISKS:           loop0 loop1 loop2 
+    LOOPBACKS:       /dev/loop0 /dev/loop1 /dev/loop2 
-NUM_DISKS:       3
+    DISKS:           loop0 loop1 loop2
-FILESIZE:        4G
+    NUM_DISKS:       3
-Keep pool(s):    rpool
+    FILESIZE:        4G
+    ITERATIONS:      1
+    TAGS:            functional
+    Keep pool(s):    rpool
 
-/usr/share/zfs/test-runner/bin/test-runner.py  -c \
-  /usr/share/zfs/runfiles/linux.run -i /usr/share/zfs/zfs-tests
-Test: .../tests/functional/acl/posix/setup (run as root) [00:00] [PASS]
-...470 additional tests...
-Test: .../tests/functional/zvol/zvol_cli/cleanup (run as root) [00:00] [PASS]
 
-Results Summary
+    /usr/share/zfs/test-runner/bin/test-runner.py  -c /usr/share/zfs/runfiles/linux.run \
-PASS	 472
+        -T functional -i /usr/share/zfs/zfs-tests -I 1
+    Test: /usr/share/zfs/zfs-tests/tests/functional/arc/setup (run as root) [00:00] [PASS]
+    ...more than 1100 additional tests...
+    Test: /usr/share/zfs/zfs-tests/tests/functional/zvol/zvol_swap/cleanup (run as root) [00:00] [PASS]
 
-Running Time:	00:45:09
+    Results Summary
-Percent passed:	100.0%
+    SKIP	  52
-Log directory:	/var/tmp/test_results/20160316T181651
+    PASS	 1129
+    
+    Running Time:	02:35:33
+    Percent passed:	95.6%
+    Log directory:	/var/tmp/test_results/20180515T054509