[PATCH] btrfs/104: replace ugly sleep with subvol sync

[PATCH] btrfs/104: replace ugly sleep with subvol sync

[Mark Fasheh]

Btrfsprogs now has 'subvolume sync' which will wait until deleted subvolumes
are cleaned from disk.

Signed-off-by: Mark Fasheh <mfasheh@suse.de>
---
 tests/btrfs/104 | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/tests/btrfs/104 b/tests/btrfs/104
index 80161a3..6848b87 100644
--- a/tests/btrfs/104
+++ b/tests/btrfs/104
@@ -146,11 +146,9 @@ _scratch_remount
 # referenced above.
 _run_btrfs_util_prog subvolume delete $SCRATCH_MNT/snap1
 
-# There is no way from userspace to force btrfs_drop_snapshot to run
-# at a given time (even via mount/unmount). We must wait for it to
-# start and complete. This is the shortest time on my tests systems I
-# have found which always allows drop_snapshot to run to completion.
-sleep 45
+# Subvol delete is a delayed operation, wait for it to complete before
+# unmounting.
+_run_btrfs_util_prog subvolume sync $SCRATCH_MNT
 
 _scratch_unmount
 
-- 
2.1.2

Re: [PATCH] btrfs/104: replace ugly sleep with subvol sync

[Dave Chinner]

Hi Mark,

On Mon, Nov 09, 2015 at 04:30:02PM -0800, Mark Fasheh wrote:
> Btrfsprogs now has 'subvolume sync' which will wait until deleted subvolumes
> are cleaned from disk.
> 
> Signed-off-by: Mark Fasheh <mfasheh@suse.de>
> ---
>  tests/btrfs/104 | 8 +++-----
>  1 file changed, 3 insertions(+), 5 deletions(-)
> 
> diff --git a/tests/btrfs/104 b/tests/btrfs/104
> index 80161a3..6848b87 100644
> --- a/tests/btrfs/104
> +++ b/tests/btrfs/104
> @@ -146,11 +146,9 @@ _scratch_remount
>  # referenced above.
>  _run_btrfs_util_prog subvolume delete $SCRATCH_MNT/snap1
>  
> -# There is no way from userspace to force btrfs_drop_snapshot to run
> -# at a given time (even via mount/unmount). We must wait for it to
> -# start and complete. This is the shortest time on my tests systems I
> -# have found which always allows drop_snapshot to run to completion.
> -sleep 45
> +# Subvol delete is a delayed operation, wait for it to complete before
> +# unmounting.
> +_run_btrfs_util_prog subvolume sync $SCRATCH_MNT

Won't that now fail on systems without the "subvolume sync"
command because of the hidden use of _run_check in
_run_btrfs_util_prog? i.e. doesn't it need to do something like:

$BTRFS_UTIL_PROG subvolume sync $SCRATCH_MNT
if [ $? -ne 0 ]; then
	sleep 45
fi

So that it works on all versions of the btrfs utility?

Cheers,

Dave.
-- 
Dave Chinner
david@fromorbit.com

Re: [PATCH] btrfs/104: replace ugly sleep with subvol sync

[Mark Fasheh]

Hi David,

On Thu, Nov 12, 2015 at 11:49:17AM +1100, Dave Chinner wrote:
> > +# Subvol delete is a delayed operation, wait for it to complete before
> > +# unmounting.
> > +_run_btrfs_util_prog subvolume sync $SCRATCH_MNT
> 
> Won't that now fail on systems without the "subvolume sync"
> command because of the hidden use of _run_check in
> _run_btrfs_util_prog? i.e. doesn't it need to do something like:
> 
> $BTRFS_UTIL_PROG subvolume sync $SCRATCH_MNT
> if [ $? -ne 0 ]; then
> 	sleep 45
> fi
> 
> So that it works on all versions of the btrfs utility?

You know, you are probably right and I should have known because we already
talked about _run_check hiding errors! I'll fix that up and send out a new
patch once I've tested the change.

Thanks,
	--Mark

--
Mark Fasheh