Re: [PATCH v3 2/3] common/rc: Add a new _require_scratch_extsize helper function

[Ritesh Harjani (IBM) <ritesh.list@gmail.com>]

Nirjhar Roy <nirjhar@linux.ibm.com> writes:

> On 11/21/24 13:23, Ritesh Harjani (IBM) wrote:
>> Nirjhar Roy <nirjhar@linux.ibm.com> writes:
>>
>>> _require_scratch_extsize helper function will be used in the
>>> the next patch to make the test run only on filesystems with
>>> extsize support.
>>>
>>> Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
>>> Signed-off-by: Nirjhar Roy <nirjhar@linux.ibm.com>
>>> ---
>>>   common/rc | 17 +++++++++++++++++
>>>   1 file changed, 17 insertions(+)
>>>
>>> diff --git a/common/rc b/common/rc
>>> index cccc98f5..995979e9 100644
>>> --- a/common/rc
>>> +++ b/common/rc
>>> @@ -48,6 +48,23 @@ _test_fsxattr_xflag()
>>>   	grep -q "fsxattr.xflags.*\[.*$2.*\]" <($XFS_IO_PROG -c "stat -v" "$1")
>>>   }
>>>   
>>> +# This test requires extsize support on the  filesystem
>>> +_require_scratch_extsize()
>>> +{
>>> +	_require_scratch
>> _require_xfs_io_command "extsize"
>>
>> ^^^ Don't we need this too?
> Yes, good point. I will add this in the next revision.
>>
>>> +	_scratch_mkfs > /dev/null
>>> +	_scratch_mount
>>> +	local filename=$SCRATCH_MNT/$RANDOM
>>> +	local blksz=$(_get_block_size $SCRATCH_MNT)
>>> +	local extsz=$(( blksz*2 ))
>>> +	local res=$($XFS_IO_PROG -c "open -f $filename" -c "extsize $extsz" \
>>> +		-c "extsize")
>>> +	_scratch_unmount
>>> +	grep -q "\[$extsz\] $filename" <(echo $res) || \
>>> +		_notrun "this test requires extsize support on the filesystem"
>> Why grep when we can simply just check the return value of previous xfs_io command?
> No, I don't think we can rely on the return value of xfs_io. For ex, 
> let's look at the following set of commands which are ran on an ext4 system:
>
> root@AMARPC: /mnt1/test$ xfs_io -V
> xfs_io version 5.13.0
> root@AMARPC: /mnt1/test$ touch new
> root@AMARPC: /mnt1/test$ xfs_io -c "extsize 8k"  new
> foreign file active, extsize command is for XFS filesystems only
> root@AMARPC: /mnt1/test$ echo "$?"
> 0
> This incorrect return value might have been fixed in some later versions 
> of xfs_io but there are still versions where we can't solely rely on the 
> return value.

Ok. That's bad, we then have to rely on grep.
Sure, thanks for checking and confirming that.

-ritesh