WayneD's clone-dest patch seems to be working for me, it's available here:
https://github.com/WayneD/rsync-patches/blob/master/clone-dest.diff
I've written some very basic tests, which I've attached to this email, in
case they are of use to anyone else. They're also available here:
https://github.com/josephmaher/rsync
Notes:
Tests need to be run as root.
clone-dest-btrs.test needs mkfs.btrfs (from btrfs-progs) and
btrs-search-metadata (from python3-btrfs).
clone-dest-xfs.test needs mkfs.xfs and xfs_bmap (from xfsprogs).
Joseph#!/bin/sh
# Copyright (C) 2024 by Joseph Maher <git...@josephmaher.org>
# This program is distributable under the terms of the GNU GPL (see COPYING)
#
# Check that the --clone-dest option makes reflinks as requested
. "$suitedir/rsync.fns"
test -f /sbin/mkfs.btrfs || test_skipped "Can't find mkfs.btrfs (only available
on Linus with btrfs support)"
test -f /usr/bin/btrfs-search-metadata || test_skipped "Can't find
btrfs-search-metatadata from python3-btrfs (only available on Linux)"
# make a btrfs filesystem and mount it
truncate -s 115M $scratchdir/btrfs.image
/sbin/mkfs.btrfs $scratchdir/btrfs.image > /dev/null
mkdir -p $scratchdir/mnt/
mount -o loop $scratchdir/btrfs.image $scratchdir/mnt/ || test_skipped "Can't
mount btrfs image file, try running as root"
# set up some test files and rsync them
mkdir $scratchdir/mnt/1 $scratchdir/mnt/2 $scratchdir/mnt/3
# files should be at least 4K in size so they fill an extent block
dd if=/dev/urandom of=$scratchdir/mnt/1/a bs=4K count=1 status=none
# sometimes the extents get cached, sycn helps write them to disk
sync $scratchdir/mnt/1/a
cp --reflink=never $scratchdir/mnt/1/a $scratchdir/mnt/1/b
sync $scratchdir/mnt/1/b
cp --reflink=never $scratchdir/mnt/1/a $scratchdir/mnt/3/a
sync $scratchdir/mnt/3/a
clonedir=$(realpath $scratchdir/mnt/3)
checkit "$RSYNC -a --clone-dest='$clonedir' '$scratchdir/mnt/1/'
'$scratchdir/mnt/2/'" "$scratchdir/mnt/1/" "$scratchdir/mnt/2/"
sync $scratchdir/mnt/2/a
sync $scratchdir/mnt/2/b
# check the extents are the same
get_extents() {
result=$(btrfs-search-metadata file $1 | grep disk_bytenr | sed
's/.*disk_bytenr\ //' | sed 's/\ disk_num_bytes.*//')
if [ ! -n "$result" ]; then
echo "couldn't find extents for " $1
fi
echo "$result"
}
test "$(get_extents $scratchdir/mnt/2/a)" = "$(get_extents
$scratchdir/mnt/3/a)" || test_fail "clone-dest files have different extents"
# clean up
umount $scratchdir/mnt/
# The script would have aborted on error, so getting here means we've won.
exit 0
#!/bin/sh
# Copyright (C) 2024 by Joseph Maher <git...@josephmaher.org>
# This program is distributable under the terms of the GNU GPL (see COPYING)
#
# Check that the --clone-dest option makes reflinks as requested
. "$suitedir/rsync.fns"
test -f /sbin/mkfs.xfs || test_skipped "Can't find mkfs.xfs (only available on
Linus with xfs support)"
# make a btrfs filesystem and mount it
truncate -s 300M $scratchdir/xfs.image
/sbin/mkfs.xfs $scratchdir/xfs.image > /dev/null
mkdir -p $scratchdir/mnt/
mount -o loop $scratchdir/xfs.image $scratchdir/mnt/ || test_skipped "Can't
mount xfs image file, try running as root"
# set up some test files and rsync them
mkdir $scratchdir/mnt/1 $scratchdir/mnt/2 $scratchdir/mnt/3
# files should be at least 4K in size so they fill an extent block
dd if=/dev/urandom of=$scratchdir/mnt/1/a bs=4K count=1 status=none
# sometimes the extents get cached, sync helps write them to disk
cp --reflink=never $scratchdir/mnt/1/a $scratchdir/mnt/1/b
cp --reflink=never $scratchdir/mnt/1/a $scratchdir/mnt/3/a
clonedir=$(realpath $scratchdir/mnt/3)
checkit "$RSYNC -a --clone-dest='$clonedir' '$scratchdir/mnt/1/'
'$scratchdir/mnt/2/'" "$scratchdir/mnt/1/" "$scratchdir/mnt/2/"
# check the extents are the same
get_extents() {
echo "$(/sbin/xfs_bmap $1 | tail -n 1)"
}
test "$(get_extents $scratchdir/mnt/2/a)" = "$(get_extents
$scratchdir/mnt/3/a)" || test_fail "clone-dest files have different extents"
# clean up
umount $scratchdir/mnt/
# The script would have aborted on error, so getting here means we've won.
exit 0
--
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