Re: [PATCH v3 1/9] fstests: sanity check that test partitions are not mounted elsewhere

Amir Goldstein
2017-02-13T11:44:44Z

On Mon, Feb 13, 2017 at 1:10 PM, Eryu Guan <eguan@redhat.com> wrote:
> On Sun, Feb 12, 2017 at 10:43:36PM +0200, Amir Goldstein wrote:
>> When $TEST_DEV is mounted at a different location then $TEST_DIR,
>> _require_test() aborts the test with an error:
>> TEST_DEV=/dev/sda5 is mounted but not on TEST_DIR=/mnt/test
>>
>> There are several problems with current sanity check:
>> 1. the output of the error is mixed into out.bad and hard to see
>> 2. the test partition is unmounted at the end of the test regardless
>> of the fact that it not pass the sanity that we have exclusivity
>> 3. scratch partition has a similar sanity check in _require_scratch(),
>> but we may not get to it, because $SCRATCH_DEV is unmounted prior
>> to running the tests (which could unmount another mount point).
>>
>> To solve all these problems, introduce a helper _check_mounted_on().
>> It checks if a device is mounted on a given mount point and optionally
>> checks the mounted fs type.
>>
>> The sanity checks in _require_scratch() and _require_test() are
>> converted to use the helper and gain the check for correct fs type.
>>
>> The helper is used in init_rc() to sanity check both test and scratch
>> partitions, before tests are run and before $SCRATCH_DEV is unmounted.
>>
>> Signed-off-by: Amir Goldstein <amir73il@gmail.com>
>> ---
>> common/rc | 83 +++++++++++++++++++++++++++++++++++++--------------------------
>> 1 file changed, 49 insertions(+), 34 deletions(-)

...

> My test configs look like:
>
> TEST_DEV=/dev/sda5
> SCRATCH_DEV=/dev/sda6
> TEST_DIR=/mnt/testarea/test
> SCRATCH_MNT=/mnt/testarea/scratch
>
> and if I mount SCRATCH_DEV at /mnt/xfs (or some other mountpoints rather
> than SCRATCH_MNT), ./check -overlay overlay/??? isn't able to detect
> this mis-configuration.
>
> [root@dhcp-66-86-11 xfstests]# ./check -overlay overlay/002
> FSTYP -- overlay
> PLATFORM -- Linux/x86_64 dhcp-66-86-11 4.10.0-rc7
> MKFS_OPTIONS -- /mnt/testarea/scratch
> MOUNT_OPTIONS -- -o context=system_u:object_r:nfs_t:s0 -o lowerdir=/mnt/testarea/scratch/ovl-lower,upperdir=/mnt/testarea/scratch/ovl-upper,workdir=/mnt/testarea/scratch/ovl-work
>
> [root@dhcp-66-86-11 xfstests]#
>
> And nothing useful was printed. This is because my rootfs has no
> filetype support, but the _notrun message is redirected to a file in
> check, as
>
> "if ! _scratch_mkfs >$tmp.err 2>&1"
>
> Adding _check_mounted_on against OVL_BASE_TEST/SCRATCH_DEV here could
> fix it for me.
>

Actually, there that test already exists in:

_scratch_mkfs
_scratch_cleanup_files
_overlay_base_scratch_mount
_check_mounted_on

Only I forgot to cleanup an unneeded _overlay_base_scratch_unmount()
from _scratch_cleanup_files()..

@@ -698,8 +698,6 @@ _scratch_cleanup_files()
overlay)
# Avoid rm -rf /* if we messed up
[ -n "$OVL_BASE_SCRATCH_MNT" ] || return 1
- # overlay 'mkfs' needs to make sure base fs is mounted and clean
- _overlay_base_scratch_unmount 2>/dev/null
_overlay_base_scratch_mount
rm -rf $OVL_BASE_SCRATCH_MNT/*
_overlay_mkdirs $OVL_BASE_SCRATCH_MNT

With this patch, test does abort for _check_mounted_on() failure,
(please verify)
but output is still lost inside tmp.err.
To fix this I would need to not exit 1 inside _check_mounted_on() but
always by callers.
Is that what you prefer that I do?