zfs: merge OpenZFS master-9305ff2ed
Notable upstream pull request merges:
#11153 Scalable teardown lock for FreeBSD #11651 Don't bomb out when using keylocation=file:// #11667 zvol: call zil_replaying() during replay #11683 abd_get_offset_struct() may allocate new abd #11693 Intentionally allow ZFS_READONLY in zfs_write #11716 zpool import cachefile improvements #11720 FreeBSD: Clean up zfsdev_close to match Linux #11730 FreeBSD: bring back possibility to rewind the checkpoint from bootloader
Obtained from: OpenZFS
MFC after: 2 weeks