Re: [PATCHv2 1/2] common/rc: Add whitelisted FS support in _require_scratch_swapfile()

[Ritesh Harjani <riteshh@linux.ibm.com>]

On 1/4/21 11:55 PM, Darrick J. Wong wrote:
> On Sun, Dec 20, 2020 at 11:39:06PM +0800, Eryu Guan wrote:
>> On Wed, Dec 16, 2020 at 10:53:45AM +0530, Ritesh Harjani wrote:
>>>
>>>
>>> On 12/16/20 10:47 AM, Ritesh Harjani wrote:
>>>> Filesystems e.g. ext4 and XFS supports swapon by default and an error
>>>> returned with swapon should be treated as a failure. Hence
>>>> add ext4/xfs as whitelisted fstype in _require_scratch_swapfile()
>>>>
>>>> Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com>
>>>> ---
>>>> v1->v2: Addressed comments from Eryu @[1]
>>>> [1]: https://patchwork.kernel.org/project/fstests/cover/cover.1604000570.git.riteshh@linux.ibm.com/
>>>>
>>>>    common/rc | 20 ++++++++++++++++----
>>>>    1 file changed, 16 insertions(+), 4 deletions(-)
>>>>
>>>> diff --git a/common/rc b/common/rc
>>>> index 33b5b598a198..635b77a005c6 100644
>>>> --- a/common/rc
>>>> +++ b/common/rc
>>>> @@ -2380,6 +2380,7 @@ _format_swapfile() {
>>>>    # Check that the filesystem supports swapfiles
>>>>    _require_scratch_swapfile()
>>>>    {
>>>> +	local fstyp=$FSTYP
>>>>    	_require_scratch
>>>>    	_require_command "$MKSWAP_PROG" "mkswap"
>>>>
>>>> @@ -2401,10 +2402,21 @@ _require_scratch_swapfile()
>>>>    	# Minimum size for mkswap is 10 pages
>>>>    	_format_swapfile "$SCRATCH_MNT/swap" $(($(get_page_size) * 10))
>>>>
>>>> -	if ! swapon "$SCRATCH_MNT/swap" >/dev/null 2>&1; then
>>>> -		_scratch_unmount
>>>> -		_notrun "swapfiles are not supported"
>>>> -	fi
>>>> +	# For whitelisted fstyp swapon should not fail.
> 
> I would use a different phase than 'whitelisted', since that doesn't
> tell us why ext4 and xfs are special:
> 
> # ext* and xfs have supported all variants of swap files since their
> # introduction, so swapon should not fail.

Sounds ok to me.


> 
>>>> +	case "$fstyp" in
> 
> $FSTYP, not $fstyp

sure I will use $FSTYP directly and remove local fstyp variable.

> 
>>>> +	ext4|xfs)
> 
> I would also add a few more FSTYPs here, since at least ext2 and ext3
> supported swap files.  Are there other old fses that do?

Sure, agreed. I will add ext2 & ext3 too.

-ritesh