pg_upgrade cannot create btrfs clones on linux kernel 6.8.0

Hello all, 

I am attempting to upgrade a postgres cluster from 16 to 17. I'm running
ubuntu 24.04 on x86_64, with postgres installed from the postgres apt
repositories. 

I'm invoking pg_upgrade like so:
/usr/lib/postgresql/17/bin/pg_upgrade --clone -d
/var/lib/postgresql/16/main -b /usr/lib/postgresql/16/bin -B
/usr/lib/postgresql/17/bin -D /var/lib/postgresql/17/main -o '-c
config_file=/etc/postgresql/16/main/postgresql.conf' -O '-c
config_file=/etc/postgresql/17/main/postgresql.conf'
and it fails with:
could not clone file between old and new data directories: Invalid
argument Failure, exiting
I ran the following strace command to find out where the problem is
happening:
sudo -u postgres strace -f -e trace=copy_file_range,clone,ioctl,%file -s
2000 -v /usr/lib/postgresql/17/bin/pg_upgrade --clone -d
/var/lib/postgresql/16/main -b /usr/lib/postgresql/16/bin -B
/usr/lib/postgresql/17/bin -D /var/lib/postgresql/17/main -o '-c
config_file=/etc/postgresql/16/main/postgresql.conf' -O '-c
config_file=/etc/postgresql/17/main/postgresql.conf'
2>/tmp/pg_strace.log
And grepping through the log I found what looks like the problem here:
-- [pid 1153372] openat(AT_FDCWD, "/etc/ld.so.cache",
O_RDONLY|O_CLOEXEC) = 8 [pid 1153372] openat(AT_FDCWD, "/lib/x86_64-
linux-gnu/libpq.so.5", O_RDONLY|O_CLOEXEC) = 8 [pid 1153261]
unlink("/var/lib/postgresql/17/main/PG_VERSION.clonetest") = 0 [pid
1153261] openat(AT_FDCWD, "/var/lib/postgresql/16/main/PG_VERSION",
O_RDONLY) = 4 [pid 1153261] openat(AT_FDCWD,
"/var/lib/postgresql/17/main/PG_VERSION.clonetest",
O_RDWR|O_CREAT|O_EXCL, 0600) = 5 [pid 1153261] ioctl(5, BTRFS_IOC_CLONE
or FICLONE, 4) = -1 EINVAL (Invalid argument)
Which I believe can be traced back to this commit
3a769d8239afdc003c91a56d2d8d5adfadacda5d
<https://git.postgresql.org/gitweb/?p=postgresql.git;a=commit;h=3a769d8239afdc003c91a56d2d8d5adfadacda5d&gt;. 

I have validated that my filesystem supports reflinks:
$ dd of=tempfile if=/dev/random bs=1M count=24 24+0 records in 24+0
records out 25165824 bytes (25 MB, 24 MiB) copied, 0.0806355 s, 312 MB/s
$ cp --reflink=always tempfile tempfile.reflink $ btrfs filesystem du -s
tempfile tempfile.reflink Total Exclusive Set shared Filename 24.00MiB
0.00B 24.00MiB tempfile 24.00MiB 0.00B 24.00MiB tempfile.reflink
And there's nothing interesting in `dmesg`. 

I ran this same command today on a macOS system (using apfs) and it
worked great. I have no idea how to fix this problem and I'm curious if
anyone has any pointers. 

Thanks,
Michael