[LTP] [PATCH] unshare01.sh: Setup parent mount flag before unshare testing

[Petr Vorel <pvorel@suse.cz>]

Hi,

> We need setup parent mount flag to shared before unshare testing, or it will
> fail for system which has no systemd service since the propagation flag is
> changed by systemd. From man 7 mount_namespaces.
Do I understand correctly that all distros without systemd are affected,
because systemd "automatically remounts all mount points as MS_SHARED
on system startup" and test expect it?

> Signed-off-by: Zhao Gongyi <zhaogongyi@huawei.com>
> ---
>  testcases/commands/unshare/unshare01.sh | 9 ++++++++-
>  1 file changed, 8 insertions(+), 1 deletion(-)

> diff --git a/testcases/commands/unshare/unshare01.sh b/testcases/commands/unshare/unshare01.sh
> index bf163a7f4..e1fb15035 100755
> --- a/testcases/commands/unshare/unshare01.sh
> +++ b/testcases/commands/unshare/unshare01.sh
> @@ -31,7 +31,6 @@ TST_SETUP=setup
>  TST_CLEANUP=cleanup
>  TST_TESTFUNC=do_test
>  TST_NEEDS_ROOT=1
> -TST_NEEDS_TMPDIR=1
You still need TST_NEEDS_TMPDIR=1, because you create files and directories.

Also your patch breaks bind test on very old systems (kernel 2.6, util-linux
2.17.2, glibc 2.12):
unshare01 5 TFAIL: unshare --mount mount --bind dir_A dir_B got bind info

Any idea why (how to avoid this regression)?

>  TST_NEEDS_CMDS="unshare id mount umount"
>  . tst_test.sh

> @@ -39,6 +38,7 @@ max_userns_path="/proc/sys/user/max_user_namespaces"
>  max_mntns_path="/proc/sys/user/max_mnt_namespaces"
>  default_max_userns=-1
>  default_max_mntns=-1
> +CURR=$(pwd)
Instead of $CURR, cd - can be used.

>  setup()
>  {
> @@ -55,6 +55,10 @@ setup()
>  		echo 1024 > "${max_mntns_path}"
>  	fi

> +	mkdir $CURR/dir_C
just mkdir dir_C
> +	mount -t tmpfs none dir_C
> +	mount --make-shared dir_C
FYI We have tst_mount, but it'd not help much here.

> +	cd dir_C
>  	mkdir -p dir_A dir_B
>  	touch dir_A/A dir_B/B
>  }
> @@ -66,6 +70,9 @@ cleanup()
>  		echo ${default_max_userns} > "${max_userns_path}"
>  	[ ${default_max_mntns} -ne -1 ] && \
>  		echo ${default_max_mntns} > "${max_mntns_path}"
> +	cd $CURR
> +	umount dir_C
tst_umount dir_C

> +	rm -rf dir_C
rm is not needed (cleanup is done automatically).
>  }

>  check_id()

Full diff of changes I propose below.

Kind regards,
Petr

diff --git testcases/commands/unshare/unshare01.sh testcases/commands/unshare/unshare01.sh
index e1fb15035..0b5c56811 100755
--- testcases/commands/unshare/unshare01.sh
+++ testcases/commands/unshare/unshare01.sh
@@ -31,6 +31,7 @@ TST_SETUP=setup
 TST_CLEANUP=cleanup
 TST_TESTFUNC=do_test
 TST_NEEDS_ROOT=1
+TST_NEEDS_TMPDIR=1
 TST_NEEDS_CMDS="unshare id mount umount"
 . tst_test.sh
 
@@ -38,7 +39,6 @@ max_userns_path="/proc/sys/user/max_user_namespaces"
 max_mntns_path="/proc/sys/user/max_mnt_namespaces"
 default_max_userns=-1
 default_max_mntns=-1
-CURR=$(pwd)
 
 setup()
 {
@@ -55,7 +55,7 @@ setup()
 		echo 1024 > "${max_mntns_path}"
 	fi
 
-	mkdir $CURR/dir_C
+	mkdir dir_C
 	mount -t tmpfs none dir_C
 	mount --make-shared dir_C
 	cd dir_C
@@ -70,9 +70,8 @@ cleanup()
 		echo ${default_max_userns} > "${max_userns_path}"
 	[ ${default_max_mntns} -ne -1 ] && \
 		echo ${default_max_mntns} > "${max_mntns_path}"
-	cd $CURR
-	umount dir_C
-	rm -rf dir_C
+	cd - >/dev/null
+	tst_umount dir_C
 }
 
 check_id()