On Fri, May 19, 2023 at 6:05 AM Anand Jain <anand.jain@xxxxxxxxxx> wrote: > > On 18/5/23 19:08, fdmanana@xxxxxxxxxx wrote: > > From: Filipe Manana <fdmanana@xxxxxxxx> > > > > btrfs/213 writes data, in 1M extents, for 4 seconds into a file, then > > triggers a balance and then after 2 seconds it tries to cancel the > > balance operation. More often than not, this works because the balance > > is still running after 2 seconds. However it also fails sporadically > > because balance has finished in less than 2 seconds, which is plausible > > since data and metadata are cached or other factors such as virtualized > > environment. When that's the case, it fails like this: > > > > $ ./check btrfs/213 > > FSTYP -- btrfs > > PLATFORM -- Linux/x86_64 debian0 6.4.0-rc1-btrfs-next-131+ #1 SMP PREEMPT_DYNAMIC Thu May 11 11:26:19 WEST 2023 > > MKFS_OPTIONS -- /dev/sdc > > MOUNT_OPTIONS -- /dev/sdc /home/fdmanana/btrfs-tests/scratch_1 > > > > btrfs/213 51s ... - output mismatch (see /home/fdmanana/git/hub/xfstests/results//btrfs/213.out.bad) > > --- tests/btrfs/213.out 2020-06-10 19:29:03.822519250 +0100 > > +++ /home/fdmanana/git/hub/xfstests/results//btrfs/213.out.bad 2023-05-17 15:39:32.653727223 +0100 > > @@ -1,2 +1,3 @@ > > QA output created by 213 > > +ERROR: balance cancel on '/home/fdmanana/btrfs-tests/scratch_1' failed: Not in progress > > Silence is golden > > ... > > (Run 'diff -u /home/fdmanana/git/hub/xfstests/tests/btrfs/213.out /home/fdmanana/git/hub/xfstests/results//btrfs/213.out.bad' to see the entire diff) > > Ran: btrfs/213 > > Failures: btrfs/213 > > Failed 1 of 1 tests > > > > To make it much less likely that balance has already finished before we > > try to cancel it, unmount and mount again the filesystem before starting > > balance, to clear cached metadata and data, and also double the time we > > spend writing 1M data extents. Also ignore when the balance failed because > > it was already finished when we tried to cancel it. > > > > Signed-off-by: Filipe Manana <fdmanana@xxxxxxxx> > > --- > > tests/btrfs/213 | 13 ++++++++++--- > > 1 file changed, 10 insertions(+), 3 deletions(-) > > > > diff --git a/tests/btrfs/213 b/tests/btrfs/213 > > index 8a10355c..cca0b3cc 100755 > > --- a/tests/btrfs/213 > > +++ b/tests/btrfs/213 > > @@ -28,7 +28,7 @@ _require_xfs_io_command pwrite -D > > _scratch_mkfs >> $seqres.full > > _scratch_mount > > > > -runtime=4 > > +runtime=8 > > > > # Create enough IO so that we need around $runtime seconds to relocate it. > > # > > @@ -39,11 +39,18 @@ sleep $runtime > > kill $write_pid > > wait $write_pid > > > > +# Unmount and mount again the fs to clear any cached data and metadata, so that > > +# it's less likely balance has already finished when we try to cancel it below. > > +_scratch_cycle_mount > > + > > # Now balance should take at least $runtime seconds, we can cancel it at > > # $runtime/2 to ensure a success cancel. > > _run_btrfs_balance_start -d --bg "$SCRATCH_MNT" > > > > -sleep $(($runtime / 2)) > > -$BTRFS_UTIL_PROG balance cancel "$SCRATCH_MNT" > > +sleep $(($runtime / 4)) > > +# It's possible that balance has already completed. It's unlikely but often > > +# it may happen due to virtualization, caching and other factors, so ignore > > +# any error about no balance currently running. > > +$BTRFS_UTIL_PROG balance cancel "$SCRATCH_MNT" 2>&1 | grep -iv 'not in progress' > > Cancel is an important step in this test case. > Why not call _notrun() if the test case fails to make sure > the balance is still in progress? This way, it provides > another opportunity to fix. Sounds reasonable. Sent a v2 with that. Thanks. > > Thanks, Anand > > > > > # Now check if we can finish relocating metadata, which should finish very > > # quickly. >
