I have confirmed that the kernel 5.13.0-20 in impish-proposed solves this problem for me.
To confirm this, I performed the following steps:
On a ZFS installation:
1) boot from kernel 5.13.0-19.19
a) observe the boot failed with PANIC at zfs_node.c: 339:zfs_znode_sa_init
2) install kernel 5.13.0-20.20 from impish-proposed
a) observe that the boot succeeds
b) observe that there are no PANIC messages in journalctl for the most recent boot.
I have confirmed that the kernel 5.13.0-20 in impish-proposed solves this problem for me.
To confirm this, I performed the following steps:
On a ZFS installation: znode_sa_ init
1) boot from kernel 5.13.0-19.19
a) observe the boot failed with PANIC at zfs_node.c: 339:zfs_
2) install kernel 5.13.0-20.20 from impish-proposed
a) observe that the boot succeeds
b) observe that there are no PANIC messages in journalctl for the most recent boot.