Re: [PATCH] fstests: btrfs try use forget to unregister device

[Eryu Guan <guaneryu@gmail.com>]

On Tue, Mar 19, 2019 at 05:49:40PM +0800, Anand Jain wrote:
> btrfs module reload was introduced to unregister devices in the btrfs
> kernel module.
> 
> The problem with the module reload approach is that you can't run btrfs
> test cases 124, 125, 154 and 164 on the system with btrfs as root fs.
> 
> Patches [1] introduced btrfs forget feature which lets to cleanup the
> kernel device list without kernel module reload.
> 
>  [1]
>  btrfs-progs: add cli to forget one or all scanned devices
>  btrfs: introduce new ioctl to unregister a btrfs device
> 
> So this patch uses forget feature instead of kernel module reload, if
> the forget feature is available.
> 
> Signed-off-by: Anand Jain <anand.jain@oracle.com>

Looks fine to me. But I'd like an explicit review from btrfs folks too.

Thanks,
Eryu

> ---
>  common/btrfs    | 20 ++++++++++++++++++++
>  tests/btrfs/124 |  6 +++---
>  tests/btrfs/125 |  6 +++---
>  tests/btrfs/154 |  6 +++---
>  tests/btrfs/164 |  4 ++--
>  5 files changed, 31 insertions(+), 11 deletions(-)
> 
> diff --git a/common/btrfs b/common/btrfs
> index f6513c06f95f..e94e011db04e 100644
> --- a/common/btrfs
> +++ b/common/btrfs
> @@ -382,3 +382,23 @@ _scratch_btrfs_sectorsize()
>  	$BTRFS_UTIL_PROG inspect-internal dump-super $SCRATCH_DEV |\
>  		grep sectorsize | awk '{print $2}'
>  }
> +
> +_btrfs_supports_forget()
> +{
> +	$BTRFS_UTIL_PROG device scan --help | grep -wq forget && \
> +		$BTRFS_UTIL_PROG device scan --forget > /dev/null 2>&1
> +}
> +
> +_require_btrfs_forget_if_not_fs_loadable()
> +{
> +	_btrfs_supports_forget && return
> +
> +	_require_loadable_fs_module "btrfs"
> +}
> +
> +_btrfs_forget_if_not_fs_reload()
> +{
> +	_btrfs_supports_forget && return
> +
> +	_reload_fs_module "btrfs"
> +}
> diff --git a/tests/btrfs/124 b/tests/btrfs/124
> index a52c65f608ff..9341dcea8896 100755
> --- a/tests/btrfs/124
> +++ b/tests/btrfs/124
> @@ -51,7 +51,7 @@ _supported_fs btrfs
>  _supported_os Linux
>  _require_scratch_dev_pool 2
>  _test_unmount
> -_require_loadable_fs_module "btrfs"
> +_require_btrfs_forget_if_not_fs_loadable
>  
>  _scratch_dev_pool_get 2
>  
> @@ -86,7 +86,7 @@ echo "clean btrfs ko" >> $seqres.full
>  _scratch_unmount
>  
>  # un-scan the btrfs devices
> -_reload_fs_module "btrfs"
> +_btrfs_forget_if_not_fs_reload
>  
>  echo >> $seqres.full
>  echo "-----Write degraded mount fill upto $max_fs_sz bytes-----" >> $seqres.full
> @@ -125,7 +125,7 @@ echo
>  echo "Mount degraded with the other dev"
>  _scratch_unmount
>  # un-scan the btrfs devices
> -_reload_fs_module "btrfs"
> +_btrfs_forget_if_not_fs_reload
>  _mount -o degraded $dev2 $SCRATCH_MNT >>$seqres.full 2>&1
>  _run_btrfs_util_prog filesystem show
>  checkpoint3=`md5sum $SCRATCH_MNT/tf2`
> diff --git a/tests/btrfs/125 b/tests/btrfs/125
> index 847fa62ad25f..3d847033f1a2 100755
> --- a/tests/btrfs/125
> +++ b/tests/btrfs/125
> @@ -50,7 +50,7 @@ _supported_fs btrfs
>  _supported_os Linux
>  _require_scratch_dev_pool 3
>  _test_unmount
> -_require_loadable_fs_module "btrfs"
> +_require_btrfs_forget_if_not_fs_loadable
>  _require_btrfs_fs_feature raid56
>  
>  _scratch_dev_pool_get 3
> @@ -103,7 +103,7 @@ echo "unmount" >> $seqres.full
>  _scratch_unmount
>  echo "clean btrfs ko" >> $seqres.full
>  # un-scan the btrfs devices
> -_reload_fs_module "btrfs"
> +_btrfs_forget_if_not_fs_reload
>  _mount -o degraded,device=$dev2 $dev1 $SCRATCH_MNT >>$seqres.full 2>&1
>  dd if=/dev/zero of="$SCRATCH_MNT"/tf2 bs=$bs count=$count \
>  					>>$seqres.full 2>&1
> @@ -139,7 +139,7 @@ echo "Mount degraded but with other dev"
>  
>  _scratch_unmount
>  # un-scan the btrfs devices
> -_reload_fs_module "btrfs"
> +_btrfs_forget_if_not_fs_reload
>  
>  _mount -o degraded,device=${dev2} $dev3 $SCRATCH_MNT >>$seqres.full 2>&1
>  
> diff --git a/tests/btrfs/154 b/tests/btrfs/154
> index cd6c688fb9fe..e39f54ac6ab8 100755
> --- a/tests/btrfs/154
> +++ b/tests/btrfs/154
> @@ -36,7 +36,7 @@ rm -f $seqres.full
>  _supported_fs btrfs
>  _supported_os Linux
>  _require_scratch_dev_pool 2
> -_require_loadable_fs_module "btrfs"
> +_require_btrfs_forget_if_not_fs_loadable
>  
>  _scratch_dev_pool_get 2
>  
> @@ -90,7 +90,7 @@ degrade_mount_write()
>  
>  	echo "clean btrfs ko" >> $seqres.full
>  	# un-scan the btrfs devices
> -	_reload_fs_module "btrfs"
> +	_btrfs_forget_if_not_fs_reload
>  	_mount -o degraded $DEV1 $SCRATCH_MNT >>$seqres.full 2>&1
>  	cnt=$(( $COUNT/10 ))
>  	dd if=/dev/urandom of="$SCRATCH_MNT"/tf1 bs=$bs count=$cnt \
> @@ -142,7 +142,7 @@ verify()
>  	echo "unmount" >> $seqres.full
>  
>  	_scratch_unmount
> -	_reload_fs_module "btrfs"
> +	_btrfs_forget_if_not_fs_reload
>  	_mount -o degraded $DEV2 $SCRATCH_MNT >>$seqres.full 2>&1
>  	verify_checkpoint1=`md5sum $SCRATCH_MNT/tf1`
>  	verify_checkpoint2=`md5sum $SCRATCH_MNT/tf2`
> diff --git a/tests/btrfs/164 b/tests/btrfs/164
> index 097191a0e493..55042c4035e0 100755
> --- a/tests/btrfs/164
> +++ b/tests/btrfs/164
> @@ -36,7 +36,7 @@ rm -f $seqres.full
>  # Modify as appropriate.
>  _supported_fs btrfs
>  _supported_os Linux
> -_require_loadable_fs_module "btrfs"
> +_require_btrfs_forget_if_not_fs_loadable
>  _require_scratch_dev_pool 2
>  
>  _scratch_dev_pool_get 2
> @@ -69,7 +69,7 @@ delete_seed()
>  {
>  	_run_btrfs_util_prog device delete $dev_seed $SCRATCH_MNT
>  	_scratch_unmount
> -	_reload_fs_module "btrfs"
> +	_btrfs_forget_if_not_fs_reload
>  	run_check _mount $dev_sprout $SCRATCH_MNT
>  	_run_btrfs_util_prog filesystem show -m $SCRATCH_MNT
>  	echo -- sprout --
> -- 
> 1.8.3.1
>