LU-12399 tests: avoid 'pdsh localhost' in sanity test_420

sanity test_420 needs a clean env to execute openfile, ie not
inherited from root user.
Replace 'pdsh localhost' with simpler 'su - $uname -c' alternative
to achieve this.

This patch is back-ported from the following one:
Lustre-commit: 1476ac047b449886a0c382b840a7b09dc0cec7eb
Lustre-change: https://review.whamcloud.com/35176

Test-Parameters: trivial envdefinitions=ONLY=420 testlist=sanity
Signed-off-by: Sebastien Buisson <sbuisson@ddn.com>
Change-Id: Ifeba7fc1eba86d74a64cca187e286adb23147e2e
Reviewed-by: Wang Shilong <wshilong@ddn.com>
Reviewed-by: James Simmons <uja.ornl@yahoo.com>
Reviewed-on: https://review.whamcloud.com/35250
Tested-by: Jenkins
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>

diff --git a/lustre/tests/sanity.sh b/lustre/tests/sanity.sh
index 2d052ba..ccda169 100755 (executable)
--- a/lustre/tests/sanity.sh
+++ b/lustre/tests/sanity.sh
@@ -19562,7 +19562,7 @@ test_420()
        [ $dirperms == "drwxrwsrwt" ] ||
                error "incorrect perms on $dir/testdir"
 
-       $PDSH ${uname}@localhost "PATH=$LUSTRE/tests:\$PATH; \
+       su - $uname -c "PATH=$LUSTRE/tests:\$PATH; \
                openfile -f O_RDONLY:O_CREAT -m 02755 $dir/testdir/testfile"
        ls -n $dir/testdir/testfile
        local fileperms=$(ls -n $dir/testdir/testfile | awk '{print $1}')