| Message ID | e5ae81c52ccbd5245014564b6fbe370ec33c966b.1667214081.git.fdmanana@suse.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | btrfs: add couple tests to check fiemap correctly reports extent sharedness | expand |
On Mon, Oct 31, 2022 at 11:11:21AM +0000, fdmanana@kernel.org wrote: > From: Filipe Manana <fdmanana@suse.com> > > Test that if we have a large file, with file extent items spanning several > leaves in the fs tree, and that is shared due to a snapshot, if we COW one > of the extents, doing a fiemap will report the respective file range as > not shared. > > This exercises the processing of delayed references for metadata extents > in the backref walking code, used by fiemap to determine if an extent is > shared. > > This used to fail until very recently and was fixed by the following > kernel commit that landed in 6.1-rc2: > > 943553ef9b51 (""btrfs: fix processing of delayed tree block refs during backref walking") > > Signed-off-by: Filipe Manana <fdmanana@suse.com> > --- Good to me, Reviewed-by: Zorro Lang <zlang@redhat.com> > tests/btrfs/280 | 64 +++++++++++++++++++++++++++++++++++++++++++++ > tests/btrfs/280.out | 21 +++++++++++++++ > 2 files changed, 85 insertions(+) > create mode 100755 tests/btrfs/280 > create mode 100644 tests/btrfs/280.out > > diff --git a/tests/btrfs/280 b/tests/btrfs/280 > new file mode 100755 > index 00000000..06ef221e > --- /dev/null > +++ b/tests/btrfs/280 > @@ -0,0 +1,64 @@ > +#! /bin/bash > +# SPDX-License-Identifier: GPL-2.0 > +# Copyright (C) 2022 SUSE Linux Products GmbH. All Rights Reserved. > +# > +# FS QA Test 280 > +# > +# Test that if we have a large file, with file extent items spanning several > +# leaves in the fs tree, and that is shared due to a snapshot, if we COW one of > +# the extents, doing a fiemap will report the respective file range as not > +# shared. > +# > +# This exercises the processing of delayed references for metadata extents in > +# the backref walking code, used by fiemap to determine if an extent is shared. > +# > +. ./common/preamble > +_begin_fstest auto quick compress snapshot fiemap > + > +. ./common/filter > +. ./common/punch # for _filter_fiemap_flags > + > +_supported_fs btrfs > +_require_scratch > +_require_xfs_io_command "fiemap" > + > +_fixed_by_kernel_commit 943553ef9b51 \ > + "btrfs: fix processing of delayed tree block refs during backref walking" > + > +_scratch_mkfs >> $seqres.full 2>&1 > +# We use compression because it's a very quick way to create a file with a very > +# large number of extents (compression limits the maximum extent size to 128K) > +# and while using very little disk space. > +_scratch_mount -o compress > + > +# A 128M file full of compressed extents results in a fs tree with a heigth > +# of 2 (root at level 1), so we'll end up with tree block references in the > +# extent tree (if the root was a leaf, we would have only data references). > +$XFS_IO_PROG -f -c "pwrite -b 1M 0 128M" $SCRATCH_MNT/foo | _filter_xfs_io > + > +# Create a RW snapshot of the default subvolume. > +$BTRFS_UTIL_PROG subvolume snapshot $SCRATCH_MNT $SCRATCH_MNT/snap | _filter_scratch > + > +echo > +echo "File foo fiemap before COWing extent:" > +echo > +$XFS_IO_PROG -c "fiemap -v" $SCRATCH_MNT/foo | _filter_fiemap_flags > + > +echo > +echo "Overwriting file range [120M, 120M + 128K) in the snapshot" > +echo > +$XFS_IO_PROG -c "pwrite -b 128K 120M 128K" $SCRATCH_MNT/snap/foo | _filter_xfs_io > +# Now fsync the file to force COWing the extent and the path from the root of > +# the snapshot tree down to the leaf where the extent is at. > +$XFS_IO_PROG -c "fsync" $SCRATCH_MNT/snap/foo > + > +echo > +echo "File foo fiemap after COWing extent in the snapshot:" > +echo > +# Now we should have all extents marked as shared except the 128K extent in the > +# file range [120M, 120M + 128K). > +$XFS_IO_PROG -c "fiemap -v" $SCRATCH_MNT/foo | _filter_fiemap_flags > + > +# success, all done > +status=0 > +exit > diff --git a/tests/btrfs/280.out b/tests/btrfs/280.out > new file mode 100644 > index 00000000..c3f82966 > --- /dev/null > +++ b/tests/btrfs/280.out > @@ -0,0 +1,21 @@ > +QA output created by 280 > +wrote 134217728/134217728 bytes at offset 0 > +XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) > +Create a snapshot of 'SCRATCH_MNT' in 'SCRATCH_MNT/snap' > + > +File foo fiemap before COWing extent: > + > +0: [0..261887]: shared > +1: [261888..262143]: shared|last > + > +Overwriting file range [120M, 120M + 128K) in the snapshot > + > +wrote 131072/131072 bytes at offset 125829120 > +XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) > + > +File foo fiemap after COWing extent in the snapshot: > + > +0: [0..245759]: shared > +1: [245760..246015]: none > +2: [246016..261887]: shared > +3: [261888..262143]: shared|last > -- > 2.35.1 >
diff --git a/tests/btrfs/280 b/tests/btrfs/280 new file mode 100755 index 00000000..06ef221e --- /dev/null +++ b/tests/btrfs/280 @@ -0,0 +1,64 @@ +#! /bin/bash +# SPDX-License-Identifier: GPL-2.0 +# Copyright (C) 2022 SUSE Linux Products GmbH. All Rights Reserved. +# +# FS QA Test 280 +# +# Test that if we have a large file, with file extent items spanning several +# leaves in the fs tree, and that is shared due to a snapshot, if we COW one of +# the extents, doing a fiemap will report the respective file range as not +# shared. +# +# This exercises the processing of delayed references for metadata extents in +# the backref walking code, used by fiemap to determine if an extent is shared. +# +. ./common/preamble +_begin_fstest auto quick compress snapshot fiemap + +. ./common/filter +. ./common/punch # for _filter_fiemap_flags + +_supported_fs btrfs +_require_scratch +_require_xfs_io_command "fiemap" + +_fixed_by_kernel_commit 943553ef9b51 \ + "btrfs: fix processing of delayed tree block refs during backref walking" + +_scratch_mkfs >> $seqres.full 2>&1 +# We use compression because it's a very quick way to create a file with a very +# large number of extents (compression limits the maximum extent size to 128K) +# and while using very little disk space. +_scratch_mount -o compress + +# A 128M file full of compressed extents results in a fs tree with a heigth +# of 2 (root at level 1), so we'll end up with tree block references in the +# extent tree (if the root was a leaf, we would have only data references). +$XFS_IO_PROG -f -c "pwrite -b 1M 0 128M" $SCRATCH_MNT/foo | _filter_xfs_io + +# Create a RW snapshot of the default subvolume. +$BTRFS_UTIL_PROG subvolume snapshot $SCRATCH_MNT $SCRATCH_MNT/snap | _filter_scratch + +echo +echo "File foo fiemap before COWing extent:" +echo +$XFS_IO_PROG -c "fiemap -v" $SCRATCH_MNT/foo | _filter_fiemap_flags + +echo +echo "Overwriting file range [120M, 120M + 128K) in the snapshot" +echo +$XFS_IO_PROG -c "pwrite -b 128K 120M 128K" $SCRATCH_MNT/snap/foo | _filter_xfs_io +# Now fsync the file to force COWing the extent and the path from the root of +# the snapshot tree down to the leaf where the extent is at. +$XFS_IO_PROG -c "fsync" $SCRATCH_MNT/snap/foo + +echo +echo "File foo fiemap after COWing extent in the snapshot:" +echo +# Now we should have all extents marked as shared except the 128K extent in the +# file range [120M, 120M + 128K). +$XFS_IO_PROG -c "fiemap -v" $SCRATCH_MNT/foo | _filter_fiemap_flags + +# success, all done +status=0 +exit diff --git a/tests/btrfs/280.out b/tests/btrfs/280.out new file mode 100644 index 00000000..c3f82966 --- /dev/null +++ b/tests/btrfs/280.out @@ -0,0 +1,21 @@ +QA output created by 280 +wrote 134217728/134217728 bytes at offset 0 +XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) +Create a snapshot of 'SCRATCH_MNT' in 'SCRATCH_MNT/snap' + +File foo fiemap before COWing extent: + +0: [0..261887]: shared +1: [261888..262143]: shared|last + +Overwriting file range [120M, 120M + 128K) in the snapshot + +wrote 131072/131072 bytes at offset 125829120 +XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) + +File foo fiemap after COWing extent in the snapshot: + +0: [0..245759]: shared +1: [245760..246015]: none +2: [246016..261887]: shared +3: [261888..262143]: shared|last