[LTP] [PATCH] syscalls/ioctl_loop05: Ensure do zero offset in kernel always

[Xiao Yang <yangx.jy@cn.fujitsu.com>]

On 2020/5/8 17:23, Yang Xu wrote:
> Hi Xiao
>
>
>> On 2020/5/8 14:15, Yang Xu wrote:
>>> Currently, we use return instead of zero_offset. I debug this code
>>> (early return, ext4 filesystem)as below:
>>> ---------------------------------------
>>> TEST(ioctl(dev_fd, LOOP_SET_DIRECT_IO, 1));
>>> if (TST_RET == 0) {
>>>     tst_res(TPASS, "LOOP_SET_DIRECT_IO succeeded unexpectedly");
>>>          SAFE_IOCTL(dev_fd, LOOP_SET_DIRECT_IO, 0);
>>> }
>>> return;
>>> ---------------------------------------
>>> this case will broke when using i parameter,
>>> ioctl_loop05.c:62: BROK: ioctl(3,LOOP_SET_DIRECT_IO,...) failed:
>>> EINVAL (22)
Hi Xu,

Sorry for the late reply.

Without modifying code, we can also fall into this branch by running 
ioctl_loop05 under btrfs, so could we simple the description of issue?

>>>
>>> It seems the last test affected this test, so I think we should use
>>> goto instead of return. Also including a typo, updata->update.
>>>
>>> Signed-off-by: Yang Xu<xuyang2018.jy@cn.fujitsu.com>
>>> ---
>>>   testcases/kernel/syscalls/ioctl/ioctl_loop05.c | 5 +++--
>>>   1 file changed, 3 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/testcases/kernel/syscalls/ioctl/ioctl_loop05.c
>>> b/testcases/kernel/syscalls/ioctl/ioctl_loop05.c
>>> index 6cf701f47..a103aaa94 100644
>>> --- a/testcases/kernel/syscalls/ioctl/ioctl_loop05.c
>>> +++ b/testcases/kernel/syscalls/ioctl/ioctl_loop05.c
>>> @@ -5,7 +5,7 @@
>>>    *
>>>    * This is a basic ioctl test about loopdevice.
>>>    *
>>> - * It is designed to test LOOP_SET_DIRECT_IO can updata a live
>>> + * It is designed to test LOOP_SET_DIRECT_IO can update a live
>> Hi Xu,
>>
>> What does the line changes?
> just a typo, updata->update

Sorry for missing the typo.

>>
>>>    * loop device dio mode. It needs the backing file also supports
>>>    * dio mode and the lo_offset is aligned with the logical block size.
>>>    *
>>> @@ -85,13 +85,14 @@ static void verify_ioctl_loop(void)
>>>       if (TST_RET == 0) {
>>>           tst_res(TPASS, "LOOP_SET_DIRECT_IO succeeded");
>>>           SAFE_IOCTL(dev_fd, LOOP_SET_DIRECT_IO, 0);
>>> -        return;
>>> +        goto zero_offset;
>>>       }
>>>       if (TST_ERR == EINVAL)
>>>           tst_res(TPASS | TTERRNO, "LOOP_SET_DIRECT_IO failed as
>>> expected");
>>>       else
>>>           tst_res(TFAIL | TTERRNO, "LOOP_SET_DIRECT_IO failed
>>> expected EINVAL got");
>>>
>>> +zero_offset:
>>>       loopinfo.lo_offset = 0;
>>>       TST_RETRY_FUNC(ioctl(dev_fd, LOOP_SET_STATUS,&loopinfo),
>>> TST_RETVAL_EQ0);
>>
>> You have cleared the struct loopinfo at the beginning of
>> verify_ioctl_loop(), so could we just drop loopinfo.lo_offset = 0 and
>> move 'TST_RETRY_FUNC(ioctl(dev_fd, LOOP_SET_STATUS,&loopinfo),
>> TST_RETVAL_EQ0);' to the beginning?
> Yes. IMO, at the beginning or end, they all work well.

Agreed, but it seems simpler to clear resouce at the beginning of 
verify_ioctl_loop(), like this:
-----------------------------------
diff --git a/testcases/kernel/syscalls/ioctl/ioctl_loop05.c 
b/testcases/kernel/syscalls/ioctl/ioctl_loop05.c
index 6cf701f47..6c9ea2802 100644
--- a/testcases/kernel/syscalls/ioctl/ioctl_loop05.c
+++ b/testcases/kernel/syscalls/ioctl/ioctl_loop05.c
...
@@ -57,6 +57,7 @@ static void verify_ioctl_loop(void)
         struct loop_info loopinfo;

         memset(&loopinfo, 0, sizeof(loopinfo));
+       TST_RETRY_FUNC(ioctl(dev_fd, LOOP_SET_STATUS, &loopinfo), 
TST_RETVAL_EQ0);

         tst_res(TINFO, "Without setting lo_offset or sizelimit");
         SAFE_IOCTL(dev_fd, LOOP_SET_DIRECT_IO, 1);
@@ -91,9 +92,6 @@ static void verify_ioctl_loop(void)
                 tst_res(TPASS | TTERRNO, "LOOP_SET_DIRECT_IO failed as 
expected");
         else
                 tst_res(TFAIL | TTERRNO, "LOOP_SET_DIRECT_IO failed 
expected EINVAL got");
-
-       loopinfo.lo_offset = 0;
-       TST_RETRY_FUNC(ioctl(dev_fd, LOOP_SET_STATUS, &loopinfo), 
TST_RETVAL_EQ0);
-----------------------------------

Best Regards,
Xiao Yang
>>
>> Thanks,
>> Xiao Yang
>>>   }
>>
> .
>