On Mon, Jun 15, 2020 at 06:50:28PM +0100, fdmanana@xxxxxxxxxx wrote: > From: Filipe Manana <fdmanana@xxxxxxxx> > > Test that creating a snapshot after writing to a file using a RWF_NOWAIT > works, does not hang the snapshot creation task, and we are able to read > the data after. > > Currently btrfs hangs when creating the snapshot due to a missing unlock > of a snapshot lock, but it is fixed by a patch with the following subject: > > "btrfs: fix hang on snapshot creation after RWF_NOWAIT write" > > Signed-off-by: Filipe Manana <fdmanana@xxxxxxxx> So sorry for the late review.. But I hit the following failure with v5.8-rc5 kernel, which contains the mentioned fix QA output created by 215 wrote 65536/65536 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) -wrote 65536/65536 bytes at offset 0 -XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) +pwrite: Input/output error Create a readonly snapshot of 'SCRATCH_MNT' in 'SCRATCH_MNT/snap' File data in the subvolume: -0000000 fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe +0000000 ab ab ab ab ab ab ab ab ab ab ab ab ab ab ab ab * 0065536 File data in the snapshot: -0000000 fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe +0000000 ab ab ab ab ab ab ab ab ab ab ab ab ab ab ab ab * 0065536 And I did hit hang when testing without the fix. Is this something that should be fixed in the test? Thanks, Eryu > --- > tests/btrfs/214 | 66 +++++++++++++++++++++++++++++++++++++++++++++ > tests/btrfs/214.out | 14 ++++++++++ > tests/btrfs/group | 1 + > 3 files changed, 81 insertions(+) > create mode 100755 tests/btrfs/214 > create mode 100644 tests/btrfs/214.out > > diff --git a/tests/btrfs/214 b/tests/btrfs/214 > new file mode 100755 > index 00000000..c835e844 > --- /dev/null > +++ b/tests/btrfs/214 > @@ -0,0 +1,66 @@ > +#! /bin/bash > +# SPDX-License-Identifier: GPL-2.0 > +# Copyright (C) 2020 SUSE Linux Products GmbH. All Rights Reserved. > +# > +# FSQA Test No. 214 > +# > +# Test that creating a snapshot after writing to a file using a RWF_NOWAIT > +# works, does not hang the snapshot creation task, and we are able to read > +# the data after. > +# > +seq=`basename $0` > +seqres=$RESULT_DIR/$seq > +echo "QA output created by $seq" > +tmp=/tmp/$$ > +status=1 # failure is the default! > +trap "_cleanup; exit \$status" 0 1 2 3 15 > + > +_cleanup() > +{ > + cd / > + rm -f $tmp.* > +} > + > +# get standard environment, filters and checks > +. ./common/rc > +. ./common/filter > +. ./common/attr > + > +# real QA test starts here > +_supported_fs btrfs > +_supported_os Linux > +_require_scratch > +_require_odirect > +_require_xfs_io_command pwrite -N > +_require_chattr C > + > +rm -f $seqres.full > + > +_scratch_mkfs >>$seqres.full 2>&1 > +_scratch_mount > + > +# RWF_NOWAIT writes require NOCOW > +touch $SCRATCH_MNT/f > +$CHATTR_PROG +C $SCRATCH_MNT/f > + > +$XFS_IO_PROG -d -c "pwrite -S 0xab 0 64K" $SCRATCH_MNT/f | _filter_xfs_io > + > +# Now do a WEF_WRITE into a range containing a NOCOWable extent. > +$XFS_IO_PROG -d -c "pwrite -N -V 1 -S 0xfe 0 64K" $SCRATCH_MNT/f \ > + | _filter_xfs_io > + > +$BTRFS_UTIL_PROG subvolume snapshot -r $SCRATCH_MNT $SCRATCH_MNT/snap \ > + | _filter_scratch > + > +# Unmount, mount again and verify the file in the subvolume and snapshot has > +# the correct data. > +_scratch_cycle_mount > + > +echo "File data in the subvolume:" > +od -A d -t x1 $SCRATCH_MNT/f > + > +echo "File data in the snapshot:" > +od -A d -t x1 $SCRATCH_MNT/snap/f > + > +status=0 > +exit > diff --git a/tests/btrfs/214.out b/tests/btrfs/214.out > new file mode 100644 > index 00000000..6cc66972 > --- /dev/null > +++ b/tests/btrfs/214.out > @@ -0,0 +1,14 @@ > +QA output created by 214 > +wrote 65536/65536 bytes at offset 0 > +XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) > +wrote 65536/65536 bytes at offset 0 > +XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) > +Create a readonly snapshot of 'SCRATCH_MNT' in 'SCRATCH_MNT/snap' > +File data in the subvolume: > +0000000 fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe > +* > +0065536 > +File data in the snapshot: > +0000000 fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe > +* > +0065536 > diff --git a/tests/btrfs/group b/tests/btrfs/group > index 9e48ecc1..a3706e7d 100644 > --- a/tests/btrfs/group > +++ b/tests/btrfs/group > @@ -216,3 +216,4 @@ > 211 auto quick log prealloc > 212 auto balance dangerous > 213 auto balance dangerous > +214 auto quick snapshot > -- > 2.26.2