generic/509 fails on btrfs on v5.17-rc7

gistfile1.txt

root@linux517-btrfs-noraid56 /var/lib/xfstests # cat results/linux517-btrfs-noraid56/5.17.0-rc7/btrfs_noraid56/generic/509.full
btrfs-progs v5.17
See http://btrfs.wiki.kernel.org for more information.

Performing full device TRIM /dev/loop5 (20.00GiB) ...
NOTE: several default settings have changed in version 5.15, please make sure
      this does not affect your deployments:
      - DUP for metadata (-m dup)
      - enabled no-holes (-O no-holes)
      - enabled free-space-tree (-R free-space-tree)

Label:              (null)
UUID:               400db6d2-d4b2-47e5-b69d-1df0625169f1
Node size:          16384
Sector size:        4096
Filesystem size:    20.00GiB
Block group profiles:
  Data:             single            8.00MiB
  Metadata:         DUP             256.00MiB
  System:           DUP               8.00MiB
SSD detected:       yes
Zoned device:       no
Incompat features:  extref, skinny-metadata, no-holes
Runtime features:   free-space-tree
Checksum:           crc32c
Number of devices:  1
Devices:
   ID        SIZE  PATH
    1    20.00GiB  /dev/loop5

device-mapper: reload ioctl on flakey-test (253:0) failed: Device or resource busy
Command failed.
device-mapper: remove ioctl on flakey-test  failed: No such device or address
Command failed.
root@linux517-btrfs-noraid56 /var/lib/xfstests # cat results/linux517-btrfs-noraid56/5.17.0-rc7/btrfs_noraid56/generic/509.out.bad
QA output created by 509
failed to create flakey device


On the kernel ring buffer:

Jun 02 06:57:42 linux517-btrfs-noraid56 unknown: run fstests generic/509 at 2022-06-02 06:57:42
Jun 02 06:57:43 linux517-btrfs-noraid56 kernel: BTRFS: device fsid 400db6d2-d4b2-47e5-b69d-1df0625169f1 devid 1 transid 6 /dev/loop5 scanned by mkfs.btrfs (2253786)
Jun 02 06:57:43 linux517-btrfs-noraid56 kernel: device-mapper: table: 253:0: flakey: Device lookup failed (-EBUSY)
Jun 02 06:57:43 linux517-btrfs-noraid56 kernel: device-mapper: ioctl: error adding target to table