Re: [PATCH 0/3] fstests: fixes for 64k pages and dax

Re: [PATCH 0/3] fstests: fixes for 64k pages and dax

[Dave Chinner]

[cc fstests@vger.kernel.org]

On Wed, Feb 05, 2020 at 05:48:15PM -0500, Jeff Moyer wrote:
> This set of patches fixes a few false positives I encountered when
> testing DAX on ppc64le (which has a 64k page size).
> 
> Patch 1 is actually not specific to non-4k page sizes.  Right now we
> only test for dax incompatibility in the dm flakey target.  This means
> that tests that use dm-thin or the snapshot target will still try to
> run.  Moving the check to _require_dm_target fixes that problem.
> 
> Patches 2 and 3 get rid of hard coded block/page sizes in the tests.
> They run just fine on 64k pages and 64k block sizes.
> 
> Even after these patches, there are many more tests that fail in the
> following configuration:
> 
> MKFS_OPTIONS="-b size=65536 -m reflink=0" MOUNT_OPTIONS="-o dax"
> 
> One class of failures is tests that create a really small file system
> size.  Some of those tests seem to require the very small size, but
> others seem like they could live with a slightly bigger size that
> would then fit the log (the typical failure is a mkfs failure due to
> not enough blocks for the log).  For the former case, I'm tempted to
> send patches to _notrun those tests, and for the latter, I'd like to
> bump the file system sizes up.  300MB seems to be large enough to
> accommodate the log.  Would folks be opposed to those approaches?
> 
> Another class of failure is tests that either hard-code a block size
> to trigger a specific error case, or that test a multitude of block
> sizes.  I'd like to send a patch to _notrun those tests if there is
> a user-specified block size.  That will require parsing the MKFS_OPTIONS
> based on the fs type, of course.  Is that something that seems
> reasonable?
> 
> I will follow up with a series of patches to implement those changes
> if there is consensus on the approach.  These first three seemed
> straight-forward to me, so that's where I'm starting.
> 
> Thanks!
> Jeff
> 
> [PATCH 1/3] dax/dm: disable testing on devices that don't support dax
> [PATCH 2/3] t_mmap_collision: fix hard-coded page size
> [PATCH 3/3] xfs/300: modify test to work on any fs block size

Hi Jeff,

You probably should be sending fstests patches to
fstests@vger.kernel.org, otherwise they probably won't get noticed
by the fstests maintainer...

Cheers,

Dave.
-- 
Dave Chinner
david@fromorbit.com

Re: [PATCH 1/3] dax/dm: disable testing on devices that don't support dax

[Zorro Lang]

On Wed, Feb 05, 2020 at 05:48:16PM -0500, Jeff Moyer wrote:
> Move the hack out of dmflakey and put it into _require_dm_target.  This
> fixes up a lot of missed tests that are failing due to the lack of dax
> support (such as tests on dm-thin, snapshot, etc).
> 
> Signed-off-by: Jeff Moyer <jmoyer@redhat.com>
> ---
>  common/dmflakey |  5 -----
>  common/rc       | 11 +++++++++++
>  2 files changed, 11 insertions(+), 5 deletions(-)
> 
> diff --git a/common/dmflakey b/common/dmflakey
> index 2af3924d..b4e11ae9 100644
> --- a/common/dmflakey
> +++ b/common/dmflakey
> @@ -8,11 +8,6 @@ FLAKEY_ALLOW_WRITES=0
>  FLAKEY_DROP_WRITES=1
>  FLAKEY_ERROR_WRITES=2
>  
> -echo $MOUNT_OPTIONS | grep -q dax
> -if [ $? -eq 0 ]; then
> -	_notrun "Cannot run tests with DAX on dmflakey devices"
> -fi

If we need to remove this for common/dmflakey, why not do the same thing
in common/dmthin and common/dmdelay etc ?

> -
>  _init_flakey()
>  {
>  	local BLK_DEV_SIZE=`blockdev --getsz $SCRATCH_DEV`
> diff --git a/common/rc b/common/rc
> index eeac1355..785f34c6 100644
> --- a/common/rc
> +++ b/common/rc
> @@ -1874,6 +1874,17 @@ _require_dm_target()
>  	_require_sane_bdev_flush $SCRATCH_DEV
>  	_require_command "$DMSETUP_PROG" dmsetup
>  
> +	echo $MOUNT_OPTIONS | grep -q dax
> +	if [ $? -eq 0 ]; then
> +		case $target in
> +		stripe|linear|error)
> +			;;
> +		*)
> +			_notrun "Cannot run tests with DAX on $target devices."
> +			;;
> +		esac
> +	fi
> +
>  	modprobe dm-$target >/dev/null 2>&1
>  
>  	$DMSETUP_PROG targets 2>&1 | grep -q ^$target
> -- 
> 2.19.1
> 

Re: [PATCH 1/3] dax/dm: disable testing on devices that don't support dax

[Jeff Moyer]

Zorro Lang <zlang@redhat.com> writes:

> On Wed, Feb 05, 2020 at 05:48:16PM -0500, Jeff Moyer wrote:
>> Move the hack out of dmflakey and put it into _require_dm_target.  This
>> fixes up a lot of missed tests that are failing due to the lack of dax
>> support (such as tests on dm-thin, snapshot, etc).
>> 
>> Signed-off-by: Jeff Moyer <jmoyer@redhat.com>
>> ---
>>  common/dmflakey |  5 -----
>>  common/rc       | 11 +++++++++++
>>  2 files changed, 11 insertions(+), 5 deletions(-)
>> 
>> diff --git a/common/dmflakey b/common/dmflakey
>> index 2af3924d..b4e11ae9 100644
>> --- a/common/dmflakey
>> +++ b/common/dmflakey
>> @@ -8,11 +8,6 @@ FLAKEY_ALLOW_WRITES=0
>>  FLAKEY_DROP_WRITES=1
>>  FLAKEY_ERROR_WRITES=2
>>  
>> -echo $MOUNT_OPTIONS | grep -q dax
>> -if [ $? -eq 0 ]; then
>> -	_notrun "Cannot run tests with DAX on dmflakey devices"
>> -fi
>
> If we need to remove this for common/dmflakey, why not do the same thing
> in common/dmthin and common/dmdelay etc ?

I didn't realize they had this same code.  I'll make that change,
thanks!

-Jeff

>
>> -
>>  _init_flakey()
>>  {
>>  	local BLK_DEV_SIZE=`blockdev --getsz $SCRATCH_DEV`
>> diff --git a/common/rc b/common/rc
>> index eeac1355..785f34c6 100644
>> --- a/common/rc
>> +++ b/common/rc
>> @@ -1874,6 +1874,17 @@ _require_dm_target()
>>  	_require_sane_bdev_flush $SCRATCH_DEV
>>  	_require_command "$DMSETUP_PROG" dmsetup
>>  
>> +	echo $MOUNT_OPTIONS | grep -q dax
>> +	if [ $? -eq 0 ]; then
>> +		case $target in
>> +		stripe|linear|error)
>> +			;;
>> +		*)
>> +			_notrun "Cannot run tests with DAX on $target devices."
>> +			;;
>> +		esac
>> +	fi
>> +
>>  	modprobe dm-$target >/dev/null 2>&1
>>  
>>  	$DMSETUP_PROG targets 2>&1 | grep -q ^$target
>> -- 
>> 2.19.1
>> 

Re: [PATCH 0/3] fstests: fixes for 64k pages and dax

[Jeff Moyer]

Dave Chinner <david@fromorbit.com> writes:

> [cc fstests@vger.kernel.org]
>
> On Wed, Feb 05, 2020 at 05:48:15PM -0500, Jeff Moyer wrote:
>> This set of patches fixes a few false positives I encountered when
>> testing DAX on ppc64le (which has a 64k page size).
>> 
>> Patch 1 is actually not specific to non-4k page sizes.  Right now we
>> only test for dax incompatibility in the dm flakey target.  This means
>> that tests that use dm-thin or the snapshot target will still try to
>> run.  Moving the check to _require_dm_target fixes that problem.
>> 
>> Patches 2 and 3 get rid of hard coded block/page sizes in the tests.
>> They run just fine on 64k pages and 64k block sizes.
>> 
>> Even after these patches, there are many more tests that fail in the
>> following configuration:
>> 
>> MKFS_OPTIONS="-b size=65536 -m reflink=0" MOUNT_OPTIONS="-o dax"
>> 
>> One class of failures is tests that create a really small file system
>> size.  Some of those tests seem to require the very small size, but
>> others seem like they could live with a slightly bigger size that
>> would then fit the log (the typical failure is a mkfs failure due to
>> not enough blocks for the log).  For the former case, I'm tempted to
>> send patches to _notrun those tests, and for the latter, I'd like to
>> bump the file system sizes up.  300MB seems to be large enough to
>> accommodate the log.  Would folks be opposed to those approaches?
>> 
>> Another class of failure is tests that either hard-code a block size
>> to trigger a specific error case, or that test a multitude of block
>> sizes.  I'd like to send a patch to _notrun those tests if there is
>> a user-specified block size.  That will require parsing the MKFS_OPTIONS
>> based on the fs type, of course.  Is that something that seems
>> reasonable?
>> 
>> I will follow up with a series of patches to implement those changes
>> if there is consensus on the approach.  These first three seemed
>> straight-forward to me, so that's where I'm starting.
>> 
>> Thanks!
>> Jeff
>> 
>> [PATCH 1/3] dax/dm: disable testing on devices that don't support dax
>> [PATCH 2/3] t_mmap_collision: fix hard-coded page size
>> [PATCH 3/3] xfs/300: modify test to work on any fs block size
>
> Hi Jeff,
>
> You probably should be sending fstests patches to
> fstests@vger.kernel.org, otherwise they probably won't get noticed
> by the fstests maintainer...

Hm, somehow I didn't know about that list.  I'll send v2 there, thanks!

-Jeff