Panic on dump over fss

[César Catrián C. <ccatrian%eml.cc@localhost>]

Hi, please help with an issue while running dump(8) over a snapshotted filesystem using fss.

The system is current 10.99.2 pvh Xen VM, compiled with mar 18 2023 sources, running under NetBSD Xen, current 10.99.2 also, with feb 23 2023 sources.

Did other successful backups on two stable NetBSD 9.3 VMs.

The dump file is being put over a nsf share in another NetBSD machine.

These are the commands used:
/usr/sbin/fssconfig fss0 /home /var/tmp
/sbin/mount /dev/fss0 /mnt/fs3
/sbin/dump -0af - /mnt/fs3 | /usr/bin/bzip2 > /mnt/fs4/backups/current/home.dump.bz2

This is the panic:
[ 1132180.1699480] /home: replaying log to disk
[ 1132181.0599390] panic: kernel diagnostic assertion "(req->req_bp->b_flags & B_PHYS) != 0" failed: file "/home/src/netbsd-current/src/sys/arch/xen/xen/xbd_xenbus.c", line 1375
[ 1132181.0599390] cpu0: Begin traceback...
[ 1132181.0599390] vpanic() at netbsd:vpanic+0x183
[ 1132181.0599390] kern_assert() at netbsd:kern_assert+0x4b
[ 1132181.0599390] xbd_diskstart() at netbsd:xbd_diskstart+0x7d4
[ 1132181.0599390] dk_start() at netbsd:dk_start+0xe0
[ 1132181.0599390] bdev_strategy() at netbsd:bdev_strategy+0x81
[ 1132181.0599390] spec_strategy() at netbsd:spec_strategy+0x6e
[ 1132181.0599390] VOP_STRATEGY() at netbsd:VOP_STRATEGY+0x3c
[ 1132181.0599390] dkstart() at netbsd:dkstart+0x184
[ 1132181.0599390] bdev_strategy() at netbsd:bdev_strategy+0x81
[ 1132181.0599390] spec_strategy() at netbsd:spec_strategy+0x6e
[ 1132181.0599390] VOP_STRATEGY() at netbsd:VOP_STRATEGY+0x3c
[ 1132181.0599390] dm_target_linear_strategy() at netbsd:dm_target_linear_strategy+0x1c
[ 1132181.0599390] dmstrategy() at netbsd:dmstrategy+0x1e0
[ 1132181.0599390] bdev_strategy() at netbsd:bdev_strategy+0x81
[ 1132181.0599390] fss_bs_thread() at netbsd:fss_bs_thread+0x32c
[ 1132181.0599390] cpu0: End traceback...

[ 1132181.0599390] dumping to dev 168,1 (offset=8, size=1048576):
[ 1132181.0599390] dump device bad


Kind regards
-- 
  César Catrián C.